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Numerous fields would be able to benefit from the protection of tissue damage by freezing. Businesses are currently investigating the use of these proteins in:
* Increasing freeze tolerance of crop plants and extending the harvest season in cooler climates
* Improving farm fish production in cooler climates
* Lengthening shelf life of frozen foods
* Improving cryosurgery
* Enhancing preservation of tissues for transplant or transfusion in medicine
* Therapy for hypothermia
* Human Cryopreservation (Cryonics)
Unilever has obtained UK, US, EU, Mexico, China, Philippines, Australia and New Zealand approval to use a genetically modified yeast to produce antifreeze proteins from fish for use in ice cream production. They are labeled "ISP" or ice structuring protein on the label, instead of AFP or antifreeze protein. | 1 | Cryobiology |
AFPs work through an interaction with small ice crystals that is similar to an enzyme-ligand binding mechanism which inhibits recrystallization of ice. This explanation of the interruption of the ice crystal structure by the AFP has come to be known as the adsorption-inhibition hypothesis.
According to this hypothesis, AFPs disrupt the thermodynamically favourable growth of an ice crystal via kinetic inhibition of contact between solid ice and liquid water. In this manner, the nucleation sites of the ice crystal lattice are blocked by the AFP, inhibiting the rapid growth of the crystal that could be fatal for the organism. In physical chemistry terms, the AFPs adsorbed onto the exposed ice crystal force the growth of the ice crystal in a convex fashion as the temperature drops, which elevates the ice vapour pressure at the nucleation sites. Ice vapour pressure continues to increase until it reaches equilibrium with the surrounding solution (water), at which point the growth of the ice crystal stops.
The aforementioned effect of AFPs on ice crystal nucleation is lost at the thermal hysteresis point. At a certain low temperature, the maximum convexity of the ice nucleation site is reached. Any further cooling will actually result in a "spreading" of the nucleation site away from this convex region, causing rapid, uncontrollable nucleation of the ice crystal. The temperature at which this phenomenon occurs is the thermal hysteresis point.<br>
The adsorption-inhibition hypothesis is further supported by the observation that antifreeze activity increases with increasing AFP concentration – the more AFPs adsorb onto the forming ice crystal, the more crowded these proteins become, making ice crystal nucleation less favourable.
In the R. inquisitor beetle, AFPs are found in the haemolymph, a fluid that bathes all the cells of the beetle and fills a cavity called the haemocoel. The presence of AFPs in R. inquisitor allows the tissues and fluids within the beetle to withstand freezing up to -30 °C (the thermal hysteresis point for this AFP). This strategy provides an obvious survival benefit to these beetles, who are endemic to cold climates, such as Scandinavia, Siberia, and Alaska. | 1 | Cryobiology |
In August 2003, the U.S. Secretary of Energy, Spencer Abraham, ordered the DOE to organize a second review of the field. This was thanks to an April 2003 letter sent by MITs Peter L. Hagelstein, and the publication of many new papers, including the Italian ENEA and other researchers in the 2003 International Cold Fusion Conference, and a two-volume book by U.S. SPAWAR in 2002. Cold fusion researchers were asked to present a review document of all the evidence since the 1989 review. The report was released in 2004. The reviewers were "split approximately evenly" on whether the experiments had produced energy in the form of heat, but "most reviewers, even those who accepted the evidence for excess power production, stated that the effects are not repeatable, the magnitude of the effect has not increased in over a decade of work, and that many of the reported experiments were not well documented'". In summary, reviewers found that cold fusion evidence was still not convincing 15 years later, and they did not recommend a federal research program. They only recommended that agencies consider funding individual well-thought studies in specific areas where research "could be helpful in resolving some of the controversies in the field". They summarized its conclusions thus:
Cold fusion researchers placed a "rosier spin" on the report, noting that they were finally being treated like normal scientists, and that the report had increased interest in the field and caused "a huge upswing in interest in funding cold fusion research". However, in a 2009 BBC article on an American Chemical Society's meeting on cold fusion, particle physicist Frank Close was quoted stating that the problems that plagued the original cold fusion announcement were still happening: results from studies are still not being independently verified and inexplicable phenomena encountered are being labelled as "cold fusion" even if they are not, in order to attract the attention of journalists.
In February 2012, millionaire Sidney Kimmel, convinced that cold fusion was worth investing in by a 19 April 2009 interview with physicist Robert Duncan on the US news show 60 Minutes, made a grant of $5.5 million to the University of Missouri to establish the Sidney Kimmel Institute for Nuclear Renaissance (SKINR). The grant was intended to support research into the interactions of hydrogen with palladium, nickel or platinum under extreme conditions. In March 2013 Graham K. Hubler, a nuclear physicist who worked for the Naval Research Laboratory for 40 years, was named director. One of the SKINR projects is to replicate a 1991 experiment in which a professor associated with the project, Mark Prelas, says bursts of millions of neutrons a second were recorded, which was stopped because "his research account had been frozen". He claims that the new experiment has already seen "neutron emissions at similar levels to the 1991 observation".
In May 2016, the United States House Committee on Armed Services, in its report on the 2017 National Defense Authorization Act, directed the Secretary of Defense to "provide a briefing on the military utility of recent U.S. industrial base LENR advancements to the House Committee on Armed Services by September 22, 2016". | 3 | Nuclear Fusion |
Plants are under horticulture care, but the environment is managed to near natural conditions. This occurs with either restored or semi-natural environments. This technique is primarily used for taxa that are rare or in areas where habitat has been severely degraded. | 1 | Cryobiology |
Since the Fleischmann and Pons announcement, the Italian national agency for new technologies, energy and sustainable economic development (ENEA) has funded Franco Scaramuzzi's research into whether excess heat can be measured from metals loaded with deuterium gas. Such research is distributed across ENEA departments, CNR laboratories, INFN, universities and industrial laboratories in Italy, where the group continues to try to achieve reliable reproducibility (i.e. getting the phenomenon to happen in every cell, and inside a certain frame of time). In 2006–2007, the ENEA started a research program which claimed to have found excess power of up to 500 percent, and in 2009, ENEA hosted the 15th cold fusion conference. | 3 | Nuclear Fusion |
Fusion reactors typically burn a mixture of deuterium (D) and tritium (T). When heated to millions of degrees, the kinetic energy in the fuel begins to overcome the natural electrostatic repulsion between nuclei, the so-called coulomb barrier, and the fuel begins to undergo fusion. This reaction gives off an alpha particle and a high energy neutron of 14 MeV. A key requirement to the economic operation of a fusion reactor is that the alphas deposit their energy back into the fuel mix, heating it so that additional fusion reactions take place. This leads to a condition not unlike the chain reaction in the fission case, known as ignition.
Deuterium can be obtained by the separation of hydrogen isotopes in sea water (see heavy water production). Tritium has a short half life of just over a decade, so only trace amounts are found in nature. To fuel the reactor, the neutrons from the reaction are used to breed more tritium through a reaction in a blanket of lithium surrounding the reaction chamber. Tritium breeding is key to the success of a D-T fusion cycle, and to date this technique has not been demonstrated. Predictions based on computer modeling suggests that the breeding ratios are quite small and a fusion plant would barely be able to cover its own use. Many years would be needed to breed enough surplus to start another reactor. | 3 | Nuclear Fusion |
Vacuum ceramic filters are to be found in the following industries:
* paper making
* metallurgy
* water treatment
* chemical
* ore beneficiation process in mining (iron, gold, nickel, copper and quartz).
The process is used during a large continuous process of separating free filtering suspensions where washing is not required. Basically the filter works to separates solid-liquid mixtures by removing the water from mineral concentrates and moulding the feed slurries into pellets. This is accomplished by capillary action under low vacuum pressure. The pelletizing of the slurries is done by adding some solid matter to the sewage sludge so that water can be easily removed from the mixture. Eventually, the final cake products contain very little moisture and can be deposited as sewage. This process is commonly followed by bleaching and heating the cake. The end product of this filtration is a dry cake and filtrate containing no solid product. | 5 | Separation Processes |
The Curie–Weiss law is an adapted version of Curie's law, which for a paramagnetic material may be written in SI units as follows, assuming :
Here μ is the permeability of free space; M the magnetization (magnetic moment per unit volume), is the magnetic field, and C the material-specific Curie constant:
where is Boltzmann's constant, the number of magnetic atoms (or molecules) per unit volume, the Landé g-factor, the Bohr magneton, the angular momentum quantum number.
For the Curie-Weiss Law the total magnetic field is where is the Weiss molecular field constant and then
which can be rearranged to get
which is the Curie-Weiss Law
where the Curie temperature is | 7 | Magnetic Ordering |
Oleum is a useful form for transporting sulfuric acid compounds, typically in rail tank cars, between oil refineries (which produce various sulfur compounds as a byproduct of refining) and industrial consumers.
Certain compositions of oleum are solid at room temperature, and thus are safer to ship than as a liquid. Solid oleum can be converted into liquid at the destination by steam heating or dilution or concentration. This requires care to prevent overheating and evaporation of sulfur trioxide. To extract it from a tank car requires careful heating using steam conduits inside the tank car. Great care must be taken to avoid overheating, as this can increase the pressure in the tank car beyond the tank's safety valve limit.
In addition, oleum is less corrosive to metals than sulfuric acid, because there is no free water to attack surfaces. Because of that, sulfuric acid is sometimes concentrated to oleum for in-plant pipelines and then diluted back to acid for use in industrial reactions.
In Richmond, California in 1993 a significant release occurred due to overheating, causing a release of sulfur trioxide that absorbed moisture from the atmosphere, creating a mist of micrometre-sized sulfuric acid particles that formed an inhalation health hazard. This mist spread over a wide area. | 4 | Acids + Bases |
In the 1990s, India stopped its research in cold fusion at the Bhabha Atomic Research Centre because of the lack of consensus among mainstream scientists and the US denunciation of the research. Yet, in 2008, the National Institute of Advanced Studies recommended that the Indian government revive this research. Projects were commenced at Chennais Indian Institute of Technology, the Bhabha Atomic Research Centre and the Indira Gandhi Centre for Atomic Research. However, there is still skepticism among scientists and, for all practical purposes, research has stalled since the 1990s. A special section in the Indian multidisciplinary journal Current Science' published 33 cold fusion papers in 2015 by major cold fusion researchers including several Indian researchers. | 3 | Nuclear Fusion |
Similar to generation of Cancer Stem Cells, EMT was demonstrated to generate endocrine progenitor cells from human pancreatic islets. Initially, the human islet-derived progenitor cells (hIPCs) were proposed to be better precursors since β-cell progeny in these hIPCs inherit epigenetic marks that define an active insulin promoter region. However, later, another set of experiments suggested that labelled β-cells de-differentiate to a mesenchymal-like phenotype in vitro, but fail to proliferate; thus initiating a debate in 2007.
Since these studies in human islets lacked lineage-tracing analysis, these findings from irreversibly tagged beta cells in mice were extrapolated to human islets. Thus, using a dual lentiviral and genetic lineage tracing system to label β-cells, it was convincingly demonstrated that adult human islet β-cells undergo EMT and proliferate in vitro. Also, these findings were confirmed in human fetal pancreatic insulin-producing cells, and the mesenchymal cells derived from pancreatic islets can undergo the reverse of EMT – MET – to generate islet-like cell aggregates. Thus, the concept of generating progenitors from insulin-producing cells by EMT or generation of Cancer Stem Cells during EMT in cancer may have potential for replacement therapy in diabetes, and call for drugs targeting inhibition of EMT in cancer. | 2 | Tissue Engineering |
*In case of long range interaction, , the thermodynamic limit is well defined if ; the magnetization remains zero if ; but the magnetization is positive, at low enough temperature, if (infrared bounds).
*As in any nearest-neighbor n-vector model with free boundary conditions, if the external field is zero, there exists a simple exact solution. | 7 | Magnetic Ordering |
A black light lamp emits long-wave UV‑A radiation and little visible light. Fluorescent black light lamps work similarly to other fluorescent lamps, but use a phosphor on the inner tube surface which emits UV‑A radiation instead of visible light. Some lamps use a deep-bluish-purple Woods glass optical filter that blocks almost all visible light with wavelengths longer than 400 nanometers. The purple glow given off by these tubes is not the ultraviolet itself, but visible purple light from mercurys 404 nm spectral line which escapes being filtered out by the coating. Other black lights use plain glass instead of the more expensive Wood's glass, so they appear light-blue to the eye when operating.
Incandescent black lights are also produced, using a filter coating on the envelope of an incandescent bulb that absorbs visible light (see section below). These are cheaper but very inefficient, emitting only a small fraction of a percent of their power as UV. Mercury-vapor black lights in ratings up to 1 kW with UV-emitting phosphor and an envelope of Wood's glass are used for theatrical and concert displays.
Black lights are used in applications in which extraneous visible light must be minimized; mainly to observe fluorescence, the colored glow that many substances give off when exposed to UV light. UV‑A / UV‑B emitting bulbs are also sold for other special purposes, such as tanning lamps and reptile-husbandry. | 8 | Ultraviolet Radiation |
The tritium breeding blanket (also known as a fusion blanket, lithium blanket or simply blanket), is a key part of many proposed fusion reactor designs. It serves several purposes; primarily it is to produce (or "breed") further tritium fuel for the nuclear fusion reaction, which owing to the scarcity of tritium would not be available in sufficient quantities, through the reaction of neutrons with lithium in the blanket. The blanket may also act as a cooling mechanism, absorbing the energy from the neutrons produced by the reaction between deuterium and tritium ("D-T"), and further serves as shielding, preventing the high-energy neutrons from escaping to the area outside the reactor and protecting the more radiation-susceptible portions, such as ohmic or superconducting magnets, from damage.
Of these three duties, it is only the breeding portion that cannot be replaced by other means. For instance, a large quantity of water makes an excellent cooling system and neutron shield, as in the case of a conventional nuclear reactor. However, tritium is not a naturally occurring resource, and thus is difficult to obtain in sufficient quantity to run a reactor through other means, so if commercial fusion using the D-T cycle is to be achieved, successful breeding of the tritium in commercial quantities is a requirement.
ITER runs a major effort in blanket design and will test a number of potential solutions. Concepts for the breeder blanket include helium-cooled lithium lead (HCLL), helium-cooled pebble bed (HCPB), and water-cooled lithium lead (WCLL) methods. Six different tritium breeding systems, known as Test Blanket Modules (TBM) wil be tested in ITER.
Some breeding blanket designs are based on lithium containing ceramics, with a focus on lithium titanate and lithium orthosilicate. These materials, mostly in a pebble form, are used to produce and extract tritium and helium; must withstand high mechanical and thermal loads; and should not become excessively radioactive upon completion of their useful service life.
To date no large-scale breeding system has been attempted, and it is an open question whether such a system is possible to create.
A fast breeder reactor uses a blanket of uranium or thorium. | 3 | Nuclear Fusion |
Dilution is the process of decreasing the concentration of a solute in a solution, usually simply by mixing with more solvent like adding more water to the solution. To dilute a solution means to add more solvent without the addition of more solute. The resulting solution is thoroughly mixed so as to ensure that all parts of the solution are identical.
The same direct relationship applies to gases and vapors diluted in air for example. Although, thorough mixing of gases and vapors may not be as easily accomplished.
For example, if there are 10 grams of salt (the solute) dissolved in 1 litre of water (the solvent), this solution has a certain salt concentration (molarity). If one adds 1 litre of water to this solution, the salt concentration is reduced. The diluted solution still contains 10 grams of salt (0.171 moles of NaCl).
Mathematically this relationship can be shown by equation:
where
*c = initial concentration or molarity
*V = initial volume
*c = final concentration or molarity
*V = final volume | 5 | Separation Processes |
Exposure to UV radiation is associated with skin aging, wrinkle production, liver spots, loss of skin elasticity, erythema (reddening of the skin), sunburn, photokeratitis (snow blindness), ocular melanoma (eye cancer), and infections. Tanning beds can contain many microbes, some of which are pathogens that can cause skin infections and gastric distress. In one study in New York in 2009, the most common pathogens found on tanning beds were Pseudomonas spp. (aeruginosa and putida), Bacillus spp., Klebsiella pneumoniae, Enterococcus species, Staphylococcus aureus, and Enterobacter cloacae. Several prescription and over-the-counter drugs, including antidepressants, antibiotics, antifungals and anti-diabetic medication, can cause photosensitivity, which makes burning the skin while tanning more likely. This risk is increased by a lack of staff training in tanning facilities. | 8 | Ultraviolet Radiation |
Carbon is a necessary component of all known life. C, a stable isotope of carbon, is abundantly produced in stars due to three factors:
# The decay lifetime of a Be nucleus is four orders of magnitude larger than the time for two He nuclei (alpha particles) to scatter.
# An excited state of the C nucleus exists a little (0.3193 MeV) above the energy level of Be + He. This is necessary because the ground state of C is 7.3367 MeV below the energy of Be + He; a Be nucleus and a He nucleus cannot reasonably fuse directly into a ground-state C nucleus. However, Be and He use the kinetic energy of their collision to fuse into the excited C (kinetic energy supplies the additional 0.3193 MeV necessary to reach the excited state), which can then transition to its stable ground state. According to one calculation, the energy level of this excited state must be between about 7.3 MeV and 7.9 MeV to produce sufficient carbon for life to exist, and must be further "fine-tuned" to between 7.596 MeV and 7.716 MeV in order to produce the abundant level of C observed in nature. The Hoyle state has been measured to be about 7.65 MeV above the ground state of C.
# In the reaction C + He → O, there is an excited state of oxygen which, if it were slightly higher, would provide a resonance and speed up the reaction. In that case, insufficient carbon would exist in nature; almost all of it would have converted to oxygen.
Some scholars argue the 7.656 MeV Hoyle resonance, in particular, is unlikely to be the product of mere chance. Fred Hoyle argued in 1982 that the Hoyle resonance was evidence of a "superintellect"; Leonard Susskind in The Cosmic Landscape rejects Hoyle's intelligent design argument. Instead, some scientists believe that different universes, portions of a vast "multiverse", have different fundamental constants: according to this controversial fine-tuning hypothesis, life can only evolve in the minority of universes where the fundamental constants happen to be fine-tuned to support the existence of life. Other scientists reject the hypothesis of the multiverse on account of the lack of independent evidence. | 3 | Nuclear Fusion |
It is uncertain whether the use of mechanical closure of the cervical canal following embryo transfer has any effect.
There is considerable evidence that prolonges bed rest (more than 20 minutes) after embryo transfer is associated with reduced chances of clinical pregnancy.
Using hyaluronic acid as an adherence medium for the embryo may increase live birth rates. There may be little or no benefit in having a full bladder, removal of cervical mucus, or flushing of the endometrial or endocervical cavity at the time of embryo transfer. Adjunctive antibiotics in the form of amoxicillin plus clavulanic acid probably does not increase the clinical pregnancy rate compared with no antibiotics. The use of Atosiban, G-CSF and hCG around the time of embryo transfer showed a trend towards increased clinical pregnancy rate.
For frozen-thawed embryo transfer or transfer of embryo from egg donation, no previous ovarian hyperstimulation is required for the recipient before transfer, which can be performed in spontaneous ovulatory cycles. Still, various protocols exist for frozen-thawed embryo transfers as well, such as protocols with ovarian hyperstimulation, protocols in which the endometrium is artificially prepared by estrogen and/or progesterone. There is some evidence that in cycles where the endometrium is artificially prepared by estrogen or progesterone, it may be beneficial to administer an additional drug that suppresses hormone production by the ovaries such as continuous administration of a gonadotropin releasing hormone agonist (GnRHa). For egg donation, there is evidence of a lower pregnancy rate and a higher cycle cancellation rate when the progesterone supplementation in the recipient is commenced prior to oocyte retrieval from the donor, as compared to commenced day of oocyte retrieval or the day after.
Seminal fluid contains several proteins that interact with epithelial cells of the cervix and uterus, inducing active gestational immune tolerance. There are significantly improved outcomes when women are exposed to seminal plasma around the time of embryo transfer, with statistical significance for clinical pregnancy, but not for ongoing pregnancy or live birth rates with the limited data available. | 1 | Cryobiology |
Hysteresis is a commonly encountered phenomenon in ecology and epidemiology, where the observed equilibrium of a system can not be predicted solely based on environmental variables, but also requires knowledge of the system's past history. Notable examples include the theory of spruce budworm outbreaks and behavioral-effects on disease transmission.
It is commonly examined in relation to critical transitions between ecosystem or community types in which dominant competitors or entire landscapes can change in a largely irreversible fashion. | 7 | Magnetic Ordering |
IVF success rates are the percentage of all IVF procedures that result in favourable outcomes. Depending on the type of calculation used, this outcome may represent the number of confirmed pregnancies, called the pregnancy rate, or the number of live births, called the live birth rate. Due to advances in reproductive technology, live birth rates by cycle five of IVF have increased from 76% in 2005 to 80% in 2010, despite a reduction in the number of embryos being transferred (which decreased the multiple birth rate from 25% to 8%).
The success rate depends on variable factors such as age of the birthing person, cause of infertility, embryo status, reproductive history, and lifestyle factors. Younger candidates of IVF are more likely to get pregnant. People older than 41 are more likely to get pregnant with a donor egg. People who have been previously pregnant are in many cases more successful with IVF treatments than those who have never been pregnant. | 1 | Cryobiology |
Pycnonuclear fusion () is a type of nuclear fusion reaction which occurs due to zero-point oscillations of nuclei around their equilibrium point bound in their crystal lattice. In quantum physics, the phenomenon can be interpreted as overlap of the wave functions of neighboring ions, and is proportional to the overlapping amplitude. Under the conditions of above-threshold ionization, the reactions of neutronization and pycnonuclear fusion can lead to the creation of absolutely stable environments in superdense substances.
The term "pycnonuclear" was coined by A.G.W. Cameron in 1959, but research showing the possibility of nuclear fusion in extremely dense and cold compositions was published by W. A. Wildhack in 1940. | 3 | Nuclear Fusion |
Imaging cleared tissues generates massive volumes of complex data, which requires powerful computational hardware and software to store, process, analyze, and visualize. A single mouse brain can generate terabytes of data. Both commercial and open-source software exists to address this need, some of it adapted from solutions for two-dimensional images and some of it designed specifically for the three-dimensional images produced by imaging of cleared tissues. | 2 | Tissue Engineering |
In phosphors and scintillators, the activator is the element added as dopant to the crystal of the material to create desired type of nonhomogeneities.
In luminescence, only a small fraction of atoms, called emission centers or luminescence centers, emit light. In inorganic phosphors, these inhomogeneities in the crystal structure are created usually by addition of a trace amount of dopants, impurities called activators. (In rare cases dislocations or other crystal defects can play the role of the impurity.) The wavelength emitted by the emission center is dependent on the atom itself, its electronic configuration, and on the surrounding crystal structure.
The activators prolong the emission time (afterglow). In turn, other materials (such as nickel) can be used to quench the afterglow and shorten the decay part of the phosphor emission characteristics.
The electronic configuration of the activator depends on its oxidation state and is crucial for the light emission. Oxidation of the activator is one of the common mechanisms of phosphor degradation. The distribution of the activator in the crystal is also of high importance. Diffusion of the ions can cause depletion of the crystal from the activators with resulting loss of efficiency. This is another mechanism of phosphor degradation.
The scintillation process in inorganic materials is due to the electronic band structure found in the crystals. An incoming particle can excite an electron from the valence band to either the conduction band or the exciton band (located just below the conduction band and separated from the valence band by an energy gap). This leaves an associated hole behind, in the valence band. Impurities create electronic levels in the forbidden gap. The excitons are loosely bound electron-hole pairs which wander through the crystal lattice until they are captured as a whole by impurity centers. The latter then rapidly de-excite by emitting scintillation light (fast component). In case of inorganic scintillators, the activator impurities are typically chosen so that the emitted light is in the visible range or near-UV where photomultipliers are effective. The holes associated with electrons in the conduction band are independent from the latter. Those holes and electrons are captured successively by impurity centers exciting certain metastable states not accessible to the excitons. The delayed de-excitation of those metastable impurity states, slowed by reliance on the low-probability forbidden mechanism, again results in light emission (slow component).
The activator is the main factor determining the phosphor emission wavelength. The nature of the host crystal can however to some degree influence the wavelength as well.
More activators can be used simultaneously.
Common examples of activators are:
* Copper, added in concentration of 5 ppm to copper-activated zinc sulfide, used in glow in the dark materials and green CRT phosphors; long afterglow
* Silver, added to zinc sulfide to produce a phosphor/scintillator used in radium dials, spinthariscopes, and as a common blue phosphor in color CRTs, and to zinc sulfide-cadmium sulfide used as a phosphor in black-and-white CRTs (where the ratio determines the blue/yellow balance of the resulting white); short afterglow
* Europium(II), added to strontium aluminate, used in high-performance glow in the dark materials, very long afterglow; with other host materials it is frequently used as the red emitter in color CRTs and fluorescent lights.
* Cerium, added to yttrium aluminium garnet used in white light emitting diodes, excited by blue light and emitting yellow
* Thallium, used in sodium iodide and caesium iodide scintillator crystals for detection of gamma radiation and for gamma spectroscopy
A newly discovered activator is Samarium(II), added to calcium fluoride. Sm(II) is one of the few materials reported which offers efficient scintillation in the red region of the spectrum, particularly when cooled by dry ice. | 0 | Luminescence |
Gough joined the School of Materials, Faculty of Science and Engineering at The University of Manchester, as a lecturer in 2002. She was quickly promoted to Senior lecturer and Reader in 2006 and 2010, respectively.
From 2012 to 2013 she was a Royal Academy of Engineering/Leverhulme Trust Senior Research Fellow. Gough was made full Professor in 2014.
Since then, she has continued her research in tissue engineering of mechanically sensitive connective tissues such as bone, cartilage, skeletal muscle and the intervertebral disc. This includes analysis and control of cells such as osteoblasts, chondrocytes, fibroblasts, keratinocytes, myoblasts and macrophages on a variety of materials and scaffolds. Her research also involves the development of scaffolds for tissue repair using novel hydrogels and magnesium alloys as various porous and fibrous materials. Gough has worked on the advisory board of the journal Biomaterials Science, and as part of the local organising committee for the World Biomaterials Congress. | 2 | Tissue Engineering |
Direct energy conversion (DEC) or simply direct conversion converts a charged particle's kinetic energy into a voltage. It is a scheme for power extraction from nuclear fusion. | 3 | Nuclear Fusion |
Taking advantage of the unique tip geometry of the NFP nanomaterials are directly injected into live cells with minimal invasiveness. This enables unique studies of nanoparticle-mediated delivery, as well as cellular pathways and toxicity. Whereas typical in vitro studies are limited to cell populations, these broadly-applicable tools enable multifaceted interrogation at a truly single cell level. | 2 | Tissue Engineering |
There is currently no evidence supporting targeted temperature management use in humans and clinical trials have not been completed. Most of the data concerning hypothermia's effectiveness in treating stroke is limited to animal studies. These studies have focused primarily on ischemic stroke as opposed to hemorrhagic stroke, as hypothermia is associated with a lower clotting threshold. In these animal studies, hypothermia was represented an effective neuroprotectant. The use of hypothermia to control intracranial pressure (ICP) after an ischemic stroke was found to be both safe and practical. | 1 | Cryobiology |
The field of building-integrated photovoltaics (BIPV) has gained attention from the scientific community due to its potential to reduce pollution and materials and electricity costs, as well as to improve the aesthetics of a building. In recent years, scientists have looked at ways to incorporate DSSC’s in BIPV applications, since the dominant Si-based PV systems in the market have a limited presence in this field due to their energy-intensive manufacturing methods, poor conversion efficiency under low light intensities, and high maintenance requirements. In 2021, a group of researchers from the Silesian University of Technology in Poland developed a DSSC in which the classic glass counter electrode was replaced by an electrode based on a ceramic tile and nickel foil. The motivation for this change was that, despite that glass substrates have resulted in the highest recorded efficiencies for DSSC’s, for BIPV applications like roof tiles or building facades, lighter and more flexible materials are essential. This includes plastic films, metals, steel, or paper, which may also reduce manufacturing costs. The team found that the cell had an efficiency of 4% (close to that of a solar cell with a glass counter electrode), demonstrated the potential for creating building-integrated DSSC’s that are stable and low-cost. | 8 | Ultraviolet Radiation |
Hypothermia is often defined as any body temperature below . With this method it is divided into degrees of severity based on the core temperature.
Another classification system, the Swiss staging system, divides hypothermia based on the presenting symptoms which is preferred when it is not possible to determine an accurate core temperature.
Other cold-related injuries that can be present either alone or in combination with hypothermia include:
*Chilblains: condition caused by repeated exposure of skin to temperatures just above freezing. The cold causes damage to small blood vessels in the skin. This damage is permanent and the redness and itching will return with additional exposure. The redness and itching typically occurs on cheeks, ears, fingers, and toes.
*Frostbite: the freezing and destruction of tissue, which happens below the freezing point of water
*Frostnip: a superficial cooling of tissues without cellular destruction
*Trench foot or immersion foot: a condition caused by repetitive exposure to water at non-freezing temperatures
The normal human body temperature is often stated as . Hyperthermia and fever, are defined as a temperature of greater than . | 1 | Cryobiology |
Aroa Biosurgery Limited first distributed OFM commercially in 2012 as Endoform™ Dermal Template (later Endoform™ Natural) through a distribution partnership with Hollister Incorporated (IL, USA). Endoform™ Natural and Endoform™ Antimicrobial (0.3% ionic silver w/w), are single layers of OFM is used in the treatment of acute and chronic wounds, including diabetic foot ulcers (DFU) and venous leg ulcers (VLU). Endoform™ Natural has been shown to accelerate wound healing of DFU. The wound product Symphony™ combines OFM and hyaluronic acid and is designed to support healing during the proliferative phase particularly in patients whose healing is severely impaired or compromised due to disease | 2 | Tissue Engineering |
Galvanoluminescence Is the emission of light produced by the passage of an electric current through an appropriate electrolyte in which an electrode, made of certain metals such as aluminium or tantalum, has been immersed. An example being the electrolysis of sodium bromide (NaBr). | 0 | Luminescence |
It is also helpful in diagnosing:
* Fungal infections. Some forms of tinea, such as Trichophyton tonsurans, do not fluoresce.
* Bacterial infections
**Corynebacterium minutissimum is coral red
**Pseudomonas is yellow-green
* Cutibacterium acnes, a bacterium involved in acne causation, exhibits an orange glow under a Wood's lamp. | 8 | Ultraviolet Radiation |
The Borexino detector is located at the Laboratori Nazionali de Gran Sasso, Italy. Borexino is an actively used detector, and experiments are on-going at the site. The goal of the Borexino experiment is measuring low energy, typically below 1 MeV, solar neutrinos in real-time. The detector is a complex structure consisting of photomultipliers, electrons, and calibration systems making it equipped to take proper measurements of the low energy solar neutrinos. Photomultipliers are used as the detection device in this system as they are able to detect light for extremely weak signals.
Solar neutrinos are able to provide direct insight into the core of the Sun because that is where the solar neutrinos originate. Solar neutrinos leaving the Sun's core reach Earth before light does due to the fact solar neutrinos do not interact with any other particle or subatomic particle during their path, while light (photons) bounces around from particle to particle. The Borexino experiment used this phenomenon to discover that the Sun releases the same amount of energy currently as it did a 100,000 years ago. | 3 | Nuclear Fusion |
Materials for 3D printing usually consist of alginate or fibrin polymers that have been integrated with cellular adhesion molecules, which support the physical attachment of cells. Such polymers are specifically designed to maintain structural stability and be receptive to cellular integration. The term bio-ink has been used as a broad classification of materials that are compatible with 3D bioprinting. Hydrogel alginates have emerged as one of the most commonly used materials in organ printing research, as they are highly customizable, and can be fine-tuned to simulate certain mechanical and biological properties characteristic of natural tissue. The ability of hydrogels to be tailored to specific needs allows them to be used as an adaptable scaffold material, that are suited for a variety of tissue or organ structures and physiological conditions. A major challenge in the use of alginate is its stability and slow degradation, which makes it difficult for the artificial gel scaffolding to be broken down and replaced with the implanted cells' own extracellular matrix. Alginate hydrogel that is suitable for extrusion printing is also often less structurally and mechanically sound; however, this issue can be mediated by the incorporation of other biopolymers, such as nanocellulose, to provide greater stability. The properties of the alginate or mixed-polymer bioink are tunable and can be altered for different applications and types of organs.
Other natural polymers that have been used for tissue and 3D organ printing include chitosan, hydroxyapatite (HA), collagen, and gelatin. Gelatin is a thermosensitive polymer with properties exhibiting excellent wear solubility, biodegradability, biocompatibility, as well as a low immunologic rejection. These qualities are advantageous and result in high acceptance of the 3D bioprinted organ when implanted in vivo. | 2 | Tissue Engineering |
In humans, excessive exposure to UV radiation can result in acute and chronic harmful effects on the eye's dioptric system and retina. The risk is elevated at high altitudes and people living in high latitude areas where snow covers the ground right into early summer and sun positions even at zenith are low, are particularly at risk. Skin, the circadian system, and the immune system can also be affected.
The differential effects of various wavelengths of light on the human cornea and skin are sometimes called the "erythemal action spectrum". The action spectrum shows that UVA does not cause immediate reaction, but rather UV begins to cause photokeratitis and skin redness (with lighter skinned individuals being more sensitive) at wavelengths starting near the beginning of the UVB band at 315 nm, and rapidly increasing to 300 nm. The skin and eyes are most sensitive to damage by UV at 265–275 nm, which is in the lower UV‑C band. At still shorter wavelengths of UV, damage continues to happen, but the overt effects are not as great with so little penetrating the atmosphere. The WHO-standard ultraviolet index is a widely publicized measurement of total strength of UV wavelengths that cause sunburn on human skin, by weighting UV exposure for action spectrum effects at a given time and location. This standard shows that most sunburn happens due to UV at wavelengths near the boundary of the UV‑A and UV‑B bands. | 8 | Ultraviolet Radiation |
In 1956, M. Cantwell predicted theoretically that the spectrum of vibrations of that ion should be observable in the infrared; and the spectra of the deuterium and common hydrogen isotopologues ( and ) should lie closer to visible light and hence easier to observe. The first detection of the spectrum of was made by D. Tolliver and others in 1979, at wavenumbers between 1,700 and 1,900 cm. In 1982, P. Bernath and T. Amano detected nine infrared lines between 2,164 and 3,158 waves per cm. | 4 | Acids + Bases |
The first frozen zoo was established at the San Diego Zoo by pathologist Kurt Benirschke in 1972. At the time there was no technology available to make use of the collection, but Benirschke believed such technology would be developed in the future. The frozen zoo idea was later supported in Gregory Benford's 1992 paper proposing a Library of Life. Zoos such as the San Diego Zoo and research programs such as the Audubon Center for Research of Endangered Species cryopreserve genetic material in order to protect the diversity of the gene pool of endangered species, or to provide for a prospective reintroduction of such extinct species as the Tasmanian tiger and the mammoth.
Gathering material for a frozen zoo is rendered simple by the abundance of sperm in males. Sperm can be taken from an animal following death. The production of eggs, which in females is usually low, can be increased through hormone treatment to obtain 10–20 oocytes, dependent on the species. Some frozen zoos prefer to fertilize eggs and freeze the resulting embryo, as embryos are more resilient under the cryopreservation process. Some centers also collect skin cell samples of endangered animals or extinct species. The Scripps Research Institute has successfully made skin cells into cultures of special cells called induced pluripotent stem cells (IPS cells). It is theoretically possible to make sperm and egg cells from these IPS cells.
Several animals whose cells were preserved in frozen zoos have been cloned to increase the genetic diversity of endangered species, . One attempt to clone an extinct species was made in 2003; the newborn Pyrenean ibex died of a development disorder which may have been linked to the cloning, and there are not enough genetic samples in frozen zoos to re-create a breeding Pyrenean ibex population. | 1 | Cryobiology |
Because fibrin fulfills the mechanical aspects of neuronal growth without initiation of glial proliferation, it can be potentially used in neuronal wound healing even with no need of growth factors or such constituents. Neurons and astrocytes, two major cell type of central nervous system, can show various responses to differences in matrix stiffness. Neuronal development of precursor cells is maintained by gels with low elastic modulus. When stiffness of the matrix is more than that of a normal brain, extension of spinal cord and cortical brain neurons is inhibited since neurite extension and branch forming take place on soft materials (, salmon fibrin promotes the neurite growth best and it is more proteolysis resistant than mammalian fibrins. Because down to 0 °C, salmon fibrinogen can clot whereas polymerization of human fibrinogen occurs slowly below 37 °C, this can be taken as an advantage in surgical settings that are cooler. Therefore, for treatment of central nervous system damages, salmon fibrin can be a useful biomaterial.
For sciatic nerve regeneration, fibrin scaffold is used with glial derived neurotrophic factor (GDNF) in a recent study. Survival of both sensory and motor neurons is promoted by glial-derived neurotrophic factor and its delivery to peripheral nervous system improves regeneration after an injury. GDNF and nerve growth factor (NGF) is sequestered in the gel via a bi-domain peptide. This peptide is composed of heparin binding domain and transglutaminase substrate domain which can be cross-linked into the fibrin matrix by polymerization via transglutaminase activity of factor XIIIa. Many neurotrophic factors can bind to heparin through its sulfated domains. This is the affinity-based delivery system in which growth factors are released by cell-based degradation control. After a 13 mm rat sciatic nerve defect is made, the fibrin matrix delivery system is applied to the gap as a nerve guiding channel. Results show that such a delivery system is efficient to enhance maturity and promote organized architecture of nerve regenerating in presence of GDNF, in addition to expressing the promising treatment variations for peripheral nerve injuries. | 2 | Tissue Engineering |
The first attempt to compute the structure of the HeH ion (specifically, ) by quantum mechanical theory was made by J. Beach in 1936. Improved computations were sporadically published over the next decades. | 4 | Acids + Bases |
One of the most important components of DSSC is the counter electrode. As stated before, the counter electrode is responsible for collecting electrons from the external circuit and introducing them back into the electrolyte to catalyze the reduction reaction of the redox shuttle, generally I to I. Thus, it is important for the counter electrode to not only have high electron conductivity and diffusive ability, but also electrochemical stability, high catalytic activity and appropriate band structure. The most common counter electrode material currently used is platinum in DSSCs, but is not sustainable owing to its high costs and scarce resources. Thus, much research has been focused towards discovering new hybrid and doped materials that can replace platinum with comparable or superior electrocatalytic performance. One such category being widely studied includes chalcogen compounds of cobalt, nickel, and iron (CCNI), particularly the effects of morphology, stoichiometry, and synergy on the resulting performance. It has been found that in addition to the elemental composition of the material, these three parameters greatly impact the resulting counter electrode efficiency. Of course, there are a variety of other materials currently being researched, such as highly mesoporous carbons, tin-based materials, gold nanostructures, as well as lead-based nanocrystals. However, the following section compiles a variety of ongoing research efforts specifically relating to CCNI towards optimizing the DSSC counter electrode performance. | 8 | Ultraviolet Radiation |
At normal temperatures pumping mechanisms in cell walls retain intracellular potassium at high levels and extrude sodium. If these pumps fail sodium is taken up by the cell and potassium lost. Water follows the sodium passively and results in swelling of the cells. The importance of this control of cell swelling was demonstrated by McLoughlin who found a significant correlation between canine renal cortical water content and the ability of kidneys to support life after 36-hour storage. The pumping mechanism is driven by the enzyme system known as Na+K+- activated ATPase and is inhibited by cold. Levy found that metabolic activity at 10 °C, as indicated by oxygen consumption measurements, was reduced to about 5% of normal and, because all enzyme systems are affected in a similar way by hypothermia, ATPase activity is markedly reduced at 10 °C.
There are, however, tissue and species differences in the cold sensitivity of this ATPase which may account for the differences in the ability of tissues to withstand hypothermia. Martin has shown that in dog kidney cortical cells some ATPase activity is still present at 10 °C but not at 0 °C. In liver and heart cells activity was completely inhibited at 10 °C and this difference in the cold sensitivity of ATPase correlated with the greater difficulty in controlling cell swelling during hypothermic storage of liver and heart cells. A distinct ATPase is found in vessel walls, and this was shown by Belzer to be completely inhibited at 10 °C, when at this temperature kidney cortical cells ATPase is still active. These experiments were performed on aortic endothelium, but if the vascular endothelium of the kidney has the same properties, then vascular injury may be the limiting factor in prolonged kidney storage.
Willis has shown how hibernators derive some of their ability to survive low temperatures by having a Na+K+-ATPase which is able to transport sodium and potassium actively across their cell membranes, at 5 °C, about six times faster than in non-hibernators; this transport rate is sufficient to prevent cell swelling.
The rate of cooling of a tissue may also be significant in the production of injury to enzyme systems. Francavilla showed that when liver slices were rapidly cooled (immediate cooling to 12 °C in 6 minutes) anaerobic glycolysis, as measured on rewarming to 37 °C, was inhibited by about 67% of the activity that was demonstrated in slices that had been subjected to delayed cooling. However, dog kidney slices were less severely affected by the rapid cooling than were the liver slices. | 1 | Cryobiology |
Zinc sulfide is also used as an infrared optical material, transmitting from visible wavelengths to just over 12 micrometers. It can be used planar as an optical window or shaped into a lens. It is made as microcrystalline sheets by the synthesis from hydrogen sulfide gas and zinc vapour, and this is sold as FLIR-grade (Forward Looking Infrared), where the zinc sulfide is in a milky-yellow, opaque form. This material when hot isostatically pressed (HIPed) can be converted to a water-clear form known as Cleartran (trademark). Early commercial forms were marketed as Irtran-2 but this designation is now obsolete. | 0 | Luminescence |
The Cativa process is a major end use of hydroiodic acid, which serves as a co-catalyst for the production of acetic acid by the carbonylation of methanol. | 4 | Acids + Bases |
Cryoablation of tumor induces necrosis of tumor cells. The immunotherapeutic effect of cryoablation of tumor is the result of the release of intracellular tumor antigens from within the necrotized tumor cells. The released tumor antigens help activate anti-tumor T cells, which destroy remaining malignant cells. Thus, cryoablation of tumor elicits a systemic anti-tumor immunologic response.
The resulting immunostimulation from cryoablation may not be sufficient to induce sustained, systemic regression of metastases, and can be synergised with the combination of immunotherapy treatment and vaccine adjuvants.
Various adjuvant immunotherapy and chemotherapy treatments can be combined with cryoablation to sustain systemic anti-tumor response with regression of metastases, including:
* Injection of immunomodulating drugs (i.e.: therapeutic antibodies) and vaccine adjuvants (saponins) directly into the cryoablated, necrotized tumor lysate, immediately after cryoablation
* Administration of autologous immune enhancement therapy, including: dendritic cell therapy, CIK cell therapy | 1 | Cryobiology |
In the United States, sperm banks are regulated as Human Cell and Tissue or Cell and Tissue Bank Product (HCT/Ps) establishments by the Food and Drug Administration (FDA) with new guidelines in effect May 25, 2005. Many states also have regulations in addition to those imposed by the FDA, including New York and California.
In the European Union a sperm bank must have a license according to the EU Tissue Directive which came into effect on April 7, 2006. In the United Kingdom, sperm banks are regulated by the Human Fertilisation and Embryology Authority.
In countries where sperm banks are allowed to operate, the sperm donor will not usually become the legal father of the children produced from the sperm he donates, but he will be the biological father of such children. In cases of surrogacy involving embryo donation, a form of gestational surrogacy, the commissioning mother or the commissioning parents will not be biologically related to the child and may need to go through an adoption procedure.
As with other forms of third party reproduction, the use of donor sperm from a sperm bank gives rise to a number of moral, legal, and ethical issues, including, but not limited to the right of the sperm donor remaining anonymous, and the child's right to know their familial background.
Furthermore, as local regulations reduce the size of the donor pool and, in some cases, exclude entire classes of potential buyers such as single women and lesbian couples, restricting donations to only heterosexual couples who are married. Some customers choose to buy abroad or on the internet, having the samples delivered at home. | 1 | Cryobiology |
Antifreeze glycoproteins or AFGPs are found in Antarctic notothenioids and northern cod. They are 2.6-3.3 kD. AFGPs evolved separately in notothenioids and northern cod. In notothenioids, the AFGP gene arose from an ancestral trypsinogen-like serine protease gene.
*Type I AFP is found in winter flounder, longhorn sculpin and shorthorn sculpin. It is the best documented AFP because it was the first to have its three-dimensional structure determined. Type I AFP consists of a single, long, amphipathic alpha helix, about 3.3-4.5 kD in size. There are three faces to the 3D structure: the hydrophobic, hydrophilic, and Thr-Asx face.
**Type I-hyp AFP (where hyp stands for hyperactive) are found in several righteye flounders. It is approximately 32 kD (two 17 kD dimeric molecules). The protein was isolated from the blood plasma of winter flounder. It is considerably better at depressing freezing temperature than most fish AFPs. The ability is partially derived from its many repeats of the Type I ice-binding site.
*Type II AFPs (e.g. ) are found in sea raven, smelt and herring. They are cysteine-rich globular proteins containing five disulfide bonds. Type II AFPs likely evolved from calcium dependent (c-type) lectins. Sea ravens, smelt, and herring are quite divergent lineages of teleost. If the AFP gene were present in the most recent common ancestor of these lineages, it is peculiar that the gene is scattered throughout those lineages, present in some orders and absent in others. It has been suggested that lateral gene transfer could be attributed to this discrepancy, such that the smelt acquired the type II AFP gene from the herring.
*Type III AFPs are found in Antarctic eelpout. They exhibit similar overall hydrophobicity at ice binding surfaces to type I AFPs. They are approximately 6kD in size. Type III AFPs likely evolved from a sialic acid synthase (SAS) gene present in Antarctic eelpout. Through a gene duplication event, this gene—which has been shown to exhibit some ice-binding activity of its own—evolved into an effective AFP gene by loss of the N-terminal part.
*Type IV AFPs () are found in longhorn sculpins. They are alpha helical proteins rich in glutamate and glutamine. This protein is approximately 12KDa in size and consists of a 4-helix bundle. Its only posttranslational modification is a pyroglutamate residue, a cyclized glutamine residue at its N-terminus. | 1 | Cryobiology |
Many metabolic chemical reporters have been developed to identify O-GlcNAc. Metabolic chemical reporters are generally sugar analogues that bear an additional chemical moiety allowing for additional reactivity. For example, peracetylated GlcNAc (AcGlcNAz) is a cell-permeable azido sugar that is de-esterified intracellularly by esterases to GlcNAz and converted to UDP-GlcNAz in the hexosamine salvage pathway. UDP-GlcNAz can be utilized as a sugar donor by OGT to yield the O-GlcNAz modification. The presence of the azido sugar can then be visualized via alkyne-containing bioorthogonal chemical probes in an azide-alkyne cycloaddition reaction. These probes can incorporate easily identifiable tags such as the FLAG peptide, biotin, and dye molecules. Mass tags based on polyethylene glycol (PEG) have also been used to measure O-GlcNAc stoichiometry. Conjugation of 5 kDa PEG molecules leads to a mass shift for modified proteins - more heavily O-GlcNAcylated proteins will have multiple PEG molecules and thus migrate more slowly in gel electrophoresis. Other metabolic chemical reporters bearing azides or alkynes (generally at the 2 or 6 positions) have been reported. Instead of GlcNAc analogues, GalNAc analogues may be used as well as UDP-GalNAc is in equilibrium with UDP-GlcNAc in cells due to the action of UDP-galactose-4-epimerase (GALE). Treatment with AcGalNAz was found to result in enhanced labeling of O-GlcNAc relative to AcGlcNAz, possibly due to a bottleneck in UDP-GlcNAc pyrophosphorylase processing of GlcNAz-1-P to UDP-GlcNAz. AcGlcN-β-Ala-NBD-α-1-P(Ac-SATE), a metabolic chemical reporter that is processed intracellularly to a fluorophore-labeled UDP-GlcNAc analogue, has been shown to achieve one-step fluorescent labeling of O-GlcNAc in live cells. Metabolic labeling may also be used to identify binding partners of O-GlcNAcylated proteins. The N-acetyl group may be elongated to incorporate a diazirine moiety. Treatment of cells with peracetylated, phosphate-protected AcGlcNDAz-1-P(Ac-SATE) leads to modification of proteins with O-GlcNDAz. UV irradiation then induces photocrosslinking between proteins bearing the O'-GlcNDaz modification and interacting proteins.
Some issues have been identified with various metabolic chemical reporters, e.g., their use may inhibit the hexosamine biosynthetic pathway, they may not be recognized by OGA and therefore are not able to capture O-GlcNAc cycling, or they may be incorporated into glycosylation modifications besides O-GlcNAc as seen in secreted proteins. Metabolic chemical reporters with chemical handles at the N-acetyl position may also label acetylated proteins as the acetyl group may be hydrolyzed into acetate analogues that can be utilized for protein acetylation. Additionally, per-O-acetylated monosaccharides have been identified to react cysteines leading to artificial S-glycosylation. This occurs via an elimination-addition mechanism. | 6 | Carbohydrates |
Five biosynthesis pathways have been reported for trehalose. The most common pathway is TPS/TPP pathway which is used by organisms that synthesize trehalose using the enzyme trehalose-6-phosphate (T6P) synthase (TPS). Second, trehalose synthase (TS) in certain types of bacteria could produce trehalose by using maltose and another disaccharide with two glucose units as substrates. Third, the TreY-TreZ pathway in some bacteria converts starch that contain maltooligosaccharide or glycogen directly into trehalose. Fourth, in primitive bacteria, trehalose glycisyltransferring synthase (TreT) produces trehalose from ADP-glucose and glucose. Fifth, trehalose phosphorylase (TreP) either hydrolyses trehalose into glucose-1-phosphate and glucose or may act reversibly in certain species. Vertebrates do not have the ability to synthesize or store trehalose. Trehalase in humans is found only in specific location such as the intestinal mucosa, renal brush-border, liver and blood. Expression of this enzyme in vertebrates is initially found during the gestation period that is the highest after weaning. Then, the level of trehalase remained constant in the intestine throughout life. Meanwhile, diets consisting of plants and fungi contain trehalose. Moderate amount of trehalose in diet is essential and having low amount of trehalose could result in diarrhea, or other intestinal symptoms. | 6 | Carbohydrates |
The following table lists all of the 122 possible three-dimensional magnetic point groups. This is given in the short version of Hermann–Mauguin notation in the following table. Here, the addition of an apostrophe to a symmetry operation indicates that the combination of the symmetry element and the antisymmetry operation is a symmetry of the structure. There are 32 Crystallographic point groups, 32 grey groups, and 58 magnetic point groups.
The magnetic point groups which are compatible with ferromagnetism are colored cyan, the magnetic point groups which are compatible with ferroelectricity are colored red, and the magnetic point groups which are compatible with both ferromagnetism and ferroelectricity are purple. There are 31 magnetic point groups which are compatible with ferromagnetism. These groups, sometimes called admissible, leave at least one component of the spin invariant under operations of the point group. There are 31 point groups compatible with ferroelectricity; these are generalizations of the crystallographic polar point groups. There are also 31 point groups compatible with the theoretically proposed ferrotorodicity. Similar symmetry arguments have been extended to other electromagnetic material properties such as magnetoelectricity or piezoelectricity.
The following diagrams show the stereographic projection of most of the magnetic point groups onto a flat surface. Not shown are the grey point groups, which look identical to the ordinary crystallographic point groups, except they are also invariant under the antisymmetry operation. | 7 | Magnetic Ordering |
The LLE describes an anisotropic magnet. The equation is described in as follows: It is an equation for a vector field S, in other words a function on R taking values in R. The equation depends on a fixed symmetric 3 by 3 matrix J, usually assumed to be diagonal; that is, . It is given by Hamilton's equation of motion for the Hamiltonian
(where J(S) is the quadratic form of J applied to the vector S)
which is
In 1+1 dimensions this equation is
In 2+1 dimensions this equation takes the form
which is the (2+1)-dimensional LLE. For the (3+1)-dimensional case LLE looks like | 7 | Magnetic Ordering |
Arsenic can sublime readily at high temperatures.
Cadmium and zinc sublime much more than other common materials, so they are not suitable materials for use in vacuum. | 5 | Separation Processes |
The filter cloth is washed on both sides with each drum rotation while discharging filter cakes. The products for this mechanism are usually sticky, wet and thin thus, requiring the aid of a discharge roll. Belt discharge is used if slurry with moderate solid concentration is used or if the slurry is easy to filter to produce cake formation or if a longer wear resistance is desired for the separation of the mentioned slurry..... | 5 | Separation Processes |
In the German/US HIBALL study, Garching used the high repetition rate of the RF driver to serve four reactor chambers using liquid lithium inside the chamber cavity. In 1982 high-confinement mode (H-mode) was discovered in tokamaks. | 3 | Nuclear Fusion |
The most common physical methods used to lyse, kill, and remove cells from the matrix of a tissue through the use of temperature, force and pressure, and electrical disruption. Temperature methods are often used in a rapid freeze-thaw mechanism. By quickly freezing a tissue, microscopic ice crystals form around the plasma membrane and the cell is lysed. After lysing the cells, the tissue can be further exposed to liquidized chemicals that degrade and wash out the undesirable components. Temperature methods conserve the physical structure of the ECM scaffold, but are best handled by thick, strong tissues.
Direct force of pressure to a tissue will guarantee disruption of the ECM structure, so pressure is commonly used. Pressure decellularization involves the controlled use of hydrostatic pressure applied to a tissue or organ. This is done best at high temperatures to avoid unmonitored ice crystal formation that could damage the scaffold. Electrical disruption of the plasma membrane is another option to lyse the cells housed in a tissue or organ. By exposing a tissue to electrical pulses, micropores are formed at the plasma membrane. The cells eventually turn to death after their homeostatic electrical balance is ruined through the applied stimulus. This electrical process is documented as Non-thermal irreversible electroporation (NTIRE) and is limited to small tissues and the limited possibilities of inducing an electric current in vivo. | 2 | Tissue Engineering |
Oxford Authentication: Home - TL Testing Authentication Oxford Authentication® Ltd authenticates ceramic antiquities using the scientific technique of thermoluminescence (TL). TL testing is a dating method for archaeological items which can distinguish between genuine and fake antiquities. See some of their case studies here: https://www.oxfordauthentication.com/case-studies/ | 0 | Luminescence |
In 1984, Martin Peng proposed an alternate arrangement of magnet coils that would greatly reduce the aspect ratio while avoiding the erosion issues of the compact tokamak: a spherical tokamak. Instead of wiring each magnet coil separately, he proposed using a single large conductor in the center, and wiring the magnets as half-rings off of this conductor. What was once a series of individual rings passing through the hole in the center of the reactor was reduced to a single post, allowing for aspect ratios as low as 1.2. The ST concept appeared to represent an enormous advance in tokamak design. The proposal came during a period when US fusion research budgets were dramatically smaller. ORNL was provided with funds to develop a suitable central column built out of a high-strength copper alloy called "Glidcop". However, they were unable to secure funding to build a demonstration machine.
Failing at ORNL, Peng began a worldwide effort to interest other teams in the concept and get a test machine built. One approach would be to convert a spheromak. Peng's advocacy caught the interest of Derek Robinson, of the United Kingdom Atomic Energy Authority. Robinson gathered a team and secured on the order of 100,000 pounds to build an experimental machine, the Small Tight Aspect Ratio Tokamak, or START. Parts of the machine were recycled from earlier projects, while others were loaned from other labs, including a 40 keV neutral beam injector from ORNL. Construction began in 1990 and operation started in January 1991. It achieved a record beta (plasma pressure compared to magnetic field pressure) of 40% using a neutral beam injector | 3 | Nuclear Fusion |
Naphthalene, an organic compound commonly found in pesticides such as mothballs, sublimes easily because it is made of non-polar molecules that are held together only by van der Waals intermolecular forces. Naphthalene is a solid that sublimes gradually at standard temperature and pressure, at a high rate, with the critical sublimation point at around 80°C or 176°F. At low temperature, its vapour pressure is high enough, 1mmHg at 53°C, to make the solid form of naphthalene evaporate into gas. On cool surfaces, the naphthalene vapours will solidify to form needle-like crystals. | 5 | Separation Processes |
Hydrazoic acid reacts with nitrous acid:
This reaction is unusual in that it involves compounds with nitrogen in four different oxidation states. | 4 | Acids + Bases |
The research on transgender reproduction and family planning is limited. A 2020 comparative study of children born to a transgender father and cisgender mother via donor sperm insemination in France showed no significant differences to IVF and naturally conceived children of cisgender parents.
Transgender men can experience challenges in pregnancy and birthing from the cis-normative structure within the medical system, as well as psychological challenges such as renewed gender dysphoria. The effect of continued testosterone therapy during pregnancy and breastfeeding is undetermined. Ethical concerns include reproductive rights, reproductive justice, physician autonomy, and transphobia within the health care setting. | 1 | Cryobiology |
"Thus, we have the ability to do away with oil (and other fossil fuels) but it will take 4–6 years and ca. $100–200M to build the full-scale plant and demonstrate it."
"Somebody will build it; and when it's built, it will work; and when it works people will begin to use it, and it will begin to displace all other forms of energy." | 3 | Nuclear Fusion |
Some animals, including birds, reptiles, and insects such as bees, can see near-ultraviolet wavelengths. Many fruits, flowers, and seeds stand out more strongly from the background in ultraviolet wavelengths as compared to human color vision. Scorpions glow or take on a yellow to green color under UV illumination, thus assisting in the control of these arachnids. Many birds have patterns in their plumage that are invisible at usual wavelengths but observable in ultraviolet, and the urine and other secretions of some animals, including dogs, cats, and human beings, are much easier to spot with ultraviolet. Urine trails of rodents can be detected by pest control technicians for proper treatment of infested dwellings.
Butterflies use ultraviolet as a communication system for sex recognition and mating behavior. For example, in the Colias eurytheme butterfly, males rely on visual cues to locate and identify females. Instead of using chemical stimuli to find mates, males are attracted to the ultraviolet-reflecting color of female hind wings. In Pieris napi butterflies it was shown that females in northern Finland with less UV-radiation present in the environment possessed stronger UV signals to attract their males than those occurring further south. This suggested that it was evolutionarily more difficult to increase the UV-sensitivity of the eyes of the males than to increase the UV-signals emitted by the females.
Many insects use the ultraviolet wavelength emissions from celestial objects as references for flight navigation. A local ultraviolet emitter will normally disrupt the navigation process and will eventually attract the flying insect.
The green fluorescent protein (GFP) is often used in genetics as a marker. Many substances, such as proteins, have significant light absorption bands in the ultraviolet that are of interest in biochemistry and related fields. UV-capable spectrophotometers are common in such laboratories.
Ultraviolet traps called bug zappers are used to eliminate various small flying insects. They are attracted to the UV and are killed using an electric shock, or trapped once they come into contact with the device. Different designs of ultraviolet radiation traps are also used by entomologists for collecting nocturnal insects during faunistic survey studies. | 8 | Ultraviolet Radiation |
There have been reports of incidents of abuse regarding forced insemination with sperm samples bought online.
Further abuse of sperm banks comes from the fertility clinic staff themselves. There have been a number of reports of staff at sperm banks and fertility clinics providing their own sperm in place of donor sperm. There have also been cases in which men have claimed their sperm sample was used by a clinic to inseminate a woman without his consent. This has led to cases of malpractice, and in some states, lobbying to create fertility fraud laws. These incidents have also led to outcry by people who had been conceived by such incidents, raising concerns of consanguinity, as well as the simple right to know who their siblings and biologic parents are. | 1 | Cryobiology |
O-GlcNAc has been implicated in influenza A virus (IAV)-induced cytokine storm. Specifically, O-GlcNAcylation of S430 on interferon regulatory factor-5 (IRF5) has been shown to promote its interaction with TNF receptor-associated factor 6 (TRAF6) in cellular and mouse models. TRAF6 mediates K63-linked ubiquitination of IRF5 which is necessary for IRF5 activity and subsequent cytokine production. Analysis of clinical samples showed that blood glucose levels were elevated in IAV-infected patients compared to healthy individuals. In IAV-infected patients, blood glucose levels positively correlated with IL-6 and IL-8 levels. O-GlcNAcylation of IRF5 was also relatively higher in peripheral blood mononuclear cells of IAV-infected patients. | 6 | Carbohydrates |
In June 1955 Bussard moved to Los Alamos and joined the Nuclear Propulsion Divisions Project Rover designing nuclear thermal rocket engines. Bussard and R.D. DeLauer wrote two important monographs on nuclear propulsion, Nuclear Rocket Propulsion and Fundamentals of Nuclear Flight'. | 3 | Nuclear Fusion |
UV curing (ultraviolet curing) is the process by which ultraviolet light initiates a photochemical reaction that generates a crosslinked network of polymers through radical polymerization or cationic polymerization. UV curing is adaptable to printing, coating, decorating, stereolithography, and in the assembly of a variety of products and materials. UV curing is a low-temperature, high speed, and solventless process as curing occurs via polymerization. Originally introduced in the 1960s, this technology has streamlined and increased automation in many industries in the manufacturing sector. | 8 | Ultraviolet Radiation |
Marcel Joseph Vogel (April 14, 1917 – February 12, 1991) was a research scientist working at the IBM San Jose Research Center for 27 years. He is sometimes referred to as Dr. Vogel, although this title was based on an honorary degree, not a Ph.D. Later in his career, he became interested in various theories of quartz crystals and other occult and esoteric fields of study. | 0 | Luminescence |
Glowsticking is the use of glow sticks in dancing (such as in glow poi and wotagei). They are frequently used for entertainment at parties (in particular raves), concerts, and dance clubs. They are used by marching band conductors for evening performances; glow sticks are also used in festivals and celebrations around the world. Glow sticks also serve multiple functions as toys, readily visible night-time warnings to motorists, and luminous markings that enable parents to keep track of their children. Another use is for balloon-carried light effects. Glow sticks are also used to create special effects in low light photography and film.
The Guinness Book of Records recorded the worlds largest glow stick was cracked at tall. It was created by the University of Wisconsin–Whitewaters Chemistry Department to celebrate the school's sesquicentennial, or 150th birthday in Whitewater, Wisconsin and cracked on 9 September 2018. | 0 | Luminescence |
There may be leftover embryos or eggs from IVF procedures if the person for whom they were originally created has successfully carried one or more pregnancies to term, and no longer wishes to use them. With the patient's permission, these may be donated to help others conceive by means of third party reproduction.
In embryo donation, these extra embryos are given to others for transfer, with the goal of producing a successful pregnancy. Embryo recipients have genetic issues or poor-quality embryos or eggs of their own. The resulting child is considered the child of whoever birthed them, and not the child of the donor, the same as occurs with egg donation or sperm donation. As per The National Infertility Association, typically, genetic parents donate the eggs or embryos to a fertility clinic where they are preserved by oocyte cryopreservation or embryo cryopreservation until a carrier is found for them. The process of matching the donation with the prospective parents is conducted by the agency itself, at which time the clinic transfers ownership of the embryos to the prospective parent(s).
Alternatives to donating unused embryos are destroying them (or having them transferred at a time when pregnancy is very unlikely), keeping them frozen indefinitely, or donating them for use in research (rendering them non-viable). Individual moral views on disposing of leftover embryos may depend on personal views on the beginning of human personhood and the definition and/or value of potential future persons, and on the value that is given to fundamental research questions. Some people believe donation of leftover embryos for research is a good alternative to discarding the embryos when patients receive proper, honest and clear information about the research project, the procedures and the scientific values.
During the embryo selection and transfer phases, many embryos may be discarded in favour of others. This selection may be based on criteria such as genetic disorders or the sex. One of the earliest cases of special gene selection through IVF was the case of the Collins family in the 1990s, who selected the sex of their child.
The ethic issues remain unresolved as no worldwide consensus exists in science, religion, and philosophy on when a human embryo should be recognised as a person. For those who believe that this is at the moment of conception, IVF becomes a moral question when multiple eggs are fertilised, begin development, and only a few are chosen for uterus transfer.
If IVF were to involve the fertilisation of only a single egg, or at least only the number that will be transferred, then this would not be an issue. However, this has the chance of increasing costs dramatically as only a few eggs can be attempted at a time. As a result, the couple must decide what to do with these extra embryos. Depending on their view of the embryo's humanity or the chance the couple will want to try to have another child, the couple has multiple options for dealing with these extra embryos. Couples can choose to keep them frozen, donate them to other infertile couples, thaw them, or donate them to medical research. Keeping them frozen costs money, donating them does not ensure they will survive, thawing them renders them immediately unviable, and medical research results in their termination. In the realm of medical research, the couple is not necessarily told what the embryos will be used for, and as a result, some can be used in stem cell research.
In February 2024, the Alabama Supreme Court ruled in LePage v. Center for Reproductive Medicine that cryopreserved embryos were "persons" or "extrauterine children". After Dobbs v. Jackson Women's Health Organization (2022), some antiabortionists had hoped to get a judgement that fetuses and embryos were "person[s]". | 1 | Cryobiology |
In Saxon settlements such as one identified in Northumberland as Bedes Ad Gefrin (now called Yeavering) the buildings were shown by an excavators reconstruction to have opposed entries. In barns a draught created by the use of these opposed doorways was used in winnowing.
The technique developed by the Chinese was not adopted in Europe until the 18th century when winnowing machines used a sail fan. The rotary winnowing fan was exported to Europe, brought there by Dutch sailors between 1700 and 1720. Apparently, they had obtained them from the Dutch settlement of Batavia in Java, Dutch East Indies. The Swedes imported some from south China at about the same time and Jesuits had taken several to France from China by 1720. Until the beginning of the 18th century, no rotary winnowing fans existed in the West. | 5 | Separation Processes |
Susceptibility to photo-oxidation varies depending on the chemical structure of the polymer. Some materials have excellent stability, such as fluoropolymers, polyimides, silicones and certain acrylate polymers. However, global polymer production is dominated by a range of commodity plastics which account for the majority of plastic waste. Of these polyethylene terephthalate (PET) has only moderate UV resistance and the others, which include polystyrene, polyvinyl chloride (PVC) and polyolefins like polypropylene (PP) and polyethylene (PE) are all highly susceptible.
Photo-oxidation is a form of photodegradation and begins with formation of free radicals on the polymer chain, which then react with oxygen in chain reactions. For many polymers the general autoxidation mechanism is a reasonable approximation of the underlying chemistry. The process is autocatalytic, generating increasing numbers of radicals and reactive oxygen species. These reactions result in changes to the molecular weight (and molecular weight distribution) of the polymer and as a consequence the material becomes more brittle. The process can be divided into four stages:
:Initiation the process of generating the initial free radical.
:Propagation the conversion of one active species to another
:Chain branching steps which end with more than one active species being produced. The photolysis of hydroperoxides is the main example.
:Termination steps in which active species are removed, for instance by radical disproportionation
Photo-oxidation can occur simultaneously with other processes like thermal degradation, and each of these can accelerate the other. | 8 | Ultraviolet Radiation |
The maximum energy product is defined based on the magnetic hysteresis saturation loop (- curve), in the demagnetizing portion where the and fields are in opposition. It is defined as the maximal value of the product of and along this curve (actually, the maximum of the negative of the product, , since they have opposing signs):
Equivalently, it can be graphically defined as the area of the largest rectangle that can be drawn between the origin and the saturation demagnetization B-H curve (see figure).
The significance of is that the volume of magnet necessary for any given application tends to be inversely proportional to . This is illustrated by considering a simple magnetic circuit containing a permanent magnet of volume and an air gap of volume , connected to each other by a magnetic core. Suppose the goal is to reach a certain field strength in the gap. In such a situation, the total magnetic energy in the gap (volume-integrated magnetic energy density) is directly equal to half the volume-integrated in the magnet:
thus in order to achieve the desired magnetic field in the gap, the required volume of magnet can be minimized by maximizing in the magnet. By choosing a magnetic material with a high , and also choosing the aspect ratio of the magnet so that its is equal to , the required volume of magnet to achieve a target flux density in the air gap is minimized. This expression assumes that the permeability in the core that is connecting the magnetic material to the air gap is infinite, so unlike the equation might imply, you cannot get arbitrarily large flux density in the air gap by decreasing the gap distance. A real core will eventually saturate. | 7 | Magnetic Ordering |
Tissue remodeling is the reorganization or renovation of existing tissues. Tissue remodeling can be either physiological or pathological. The process can either change the characteristics of a tissue such as in blood vessel remodeling, or result in the dynamic equilibrium of a tissue such as in bone remodeling. Macrophages repair wounds and remodel tissue by producing extracellular matrix and proteases to modify that specific matrix.
A myocardial infarction induces tissue remodeling of the heart in a three-phase process: inflammation, proliferation, and maturation. Inflammation is characterized by massive necrosis in the infarcted area. Inflammatory cells clear the dead cells. In the proliferation phase, inflammatory cells die by apoptosis, being replaced by myofibroblasts which produce large amounts of collagen. In the maturation phase, myofibroblast numbers are reduced by apoptosis, allowing for infiltration by endothelial cells (for blood vessels) and cardiomyocytes (heart tissue cells). Usually, however, much of the tissue remodeling is pathological, resulting in a large amount of fibrous tissue. By contrast, aerobic exercise can produce beneficial cardiac tissue remodeling in those suffering from left ventricular hypertrophy.
Programmed cellular senescence contributes to beneficial tissue remodeling during embryonic development of the fetus.
In a brain stroke the penumbra area surrounding the ischemic event initially undergoes a damaging remodeling, but later transitions to a tissue remodeling characterized by repair.
Vascular remodeling refers to a compensatory change in blood vessel walls due to plaque growth. Vascular expansion is called positive remodeling, whereas vascular constriction is called negative remodeling.
Tissue remodeling occurs in adipose tissue with increased body fat. In obese subjects, this remodeling is often pathological, characterized by excessive inflammation and fibrosis. | 2 | Tissue Engineering |
(E)-Stilbene, commonly known as trans-stilbene, is an organic compound represented by the condensed structural formula CHCH=CHCH. Classified as a diarylethene, it features a central ethylene moiety with one phenyl group substituent on each end of the carbon–carbon double bond. It has an (E) stereochemistry, meaning that the phenyl groups are located on opposite sides of the double bond, the opposite of its geometric isomer, cis-stilbene. Trans-stilbene occurs as a white crystalline solid at room temperature and is highly soluble in organic solvents. It can be converted to cis-stilbene photochemically, and further reacted to produce phenanthrene.
Stilbene was discovered in 1843 by the French chemist Auguste Laurent. The name "stilbene" is derived from the Greek word στίλβω (stilbo), which means "I shine", on account of the lustrous appearance of the compound. | 0 | Luminescence |
For small spots of vitiligo, it is possible to use psoralen as drops, applied only on the spots. This method does not have side effects since the amount is very low.
For larger area, the psoralen is taken as a pill, and the amount is high (10 mg); some patients experience nausea and itching after ingesting the psoralen compound. For these patients PUVA bath therapy may be a good option.
Long term use of PUVA therapy with a pill has been associated with higher rates of skin cancer.
The most significant complication of PUVA therapy for psoriasis is squamous cell skin cancer. Two carcinogenic components of the therapy include the nonionizing radiation of UVA light as well as the psoralen intercalation with DNA. Both processes negatively contribute to genome instability. | 8 | Ultraviolet Radiation |
In hypochlorhydria and achlorhydria, there is low or no gastric acid in the stomach, potentially leading to problems as the disinfectant properties of the gastric lumen are decreased. In such conditions, there is greater risk of infections of the digestive tract (such as infection with Vibrio or Helicobacter bacteria).
In Zollinger–Ellison syndrome and hypercalcemia, there are increased gastrin levels, leading to excess gastric acid production, which can cause gastric ulcers.
In diseases featuring excess vomiting, patients develop hypochloremic metabolic alkalosis (decreased blood acidity by H and chlorine depletion).
Gastroesophageal reflux disease occurs when stomach acid repeatedly flows back into the Esophagus, this backwash (acid reflux) can irritate the lining of the esophagus.
Many people experience acid reflux from time to time. However, when acid reflux happens repeatedly over time, it can cause .
Most people are able to manage the discomfort of with lifestyle changes and medications. While it is uncommon, some may need surgery to ease symptoms. | 4 | Acids + Bases |
Amylopectin is a water-insoluble polysaccharide and highly branched polymer of α-glucose units found in plants. It is one of the two components of starch, the other being amylose.
Plants store starch within specialized organelles called amyloplasts. To generate energy, the plant hydrolyzes the starch, releasing the glucose subunits. Humans and other animals that eat plant foods also use amylase, an enzyme that assists in breaking down amylopectin, to initiate the hydrolysis of starch.
Starch is made of about 70–80% amylopectin by weight, though it varies depending on the source. For example, it ranges from lower percent content in long-grain rice, amylomaize, and russet potatoes to 100% in glutinous rice, waxy potato starch, and waxy corn. Amylopectin is highly branched, being formed of 2,000 to 200,000 glucose units. Its inner chains are formed of 20–24 glucose subunits.
Dissolved amylopectin starch has a lower tendency of retrogradation (a partial recrystallization after cooking—a part of the staling process) during storage and cooling. For this main reason, the waxy starches are used in different applications mainly as a thickening agent or stabilizer. | 6 | Carbohydrates |
Freezing is almost always an exothermic process, meaning that as liquid changes into solid, heat and pressure are released. This is often seen as counter-intuitive, since the temperature of the material does not rise during freezing, except if the liquid were supercooled. But this can be understood since heat must be continually removed from the freezing liquid or the freezing process will stop. The energy released upon freezing is a latent heat, and is known as the enthalpy of fusion and is exactly the same as the energy required to melt the same amount of the solid.
Low-temperature helium is the only known exception to the general rule. Helium-3 has a negative enthalpy of fusion at temperatures below 0.3 K. Helium-4 also has a very slightly negative enthalpy of fusion below 0.8 K. This means that, at appropriate constant pressures, heat must be added to these substances in order to freeze them. | 1 | Cryobiology |
Trehalose is rapidly broken down into glucose by the enzyme trehalase, which is present in the brush border of the intestinal mucosa of omnivores (including humans) and herbivores. It causes less of a spike in blood sugar than glucose. Trehalose has about 45% the sweetness of sucrose at concentrations above 22%, but when the concentration is reduced, its sweetness decreases more quickly than that of sucrose, so that a 2.3% solution tastes 6.5 times less sweet as the equivalent sugar solution.
It is commonly used in prepared frozen foods, like ice cream, because it lowers the freezing point of foods.
Deficiency of trehalase enzyme is unusual in humans, except in the Greenlandic Inuit, where it occurs in 10–15% of the population. | 6 | Carbohydrates |
The settling particles can contact each other and arise when approaching the floor of the sedimentation tanks at very high particle concentration. So that further settling will only occur in adjust matrix as the sedimentation rate decreasing. This is can be illustrated by the lower region of the zone-settling diagram (Figure 3). In Compression zone, the settled solids are compressed by gravity (the weight of solids), as the settled solids are compressed under the weight of overlying solids, and water is squeezed out while the space gets smaller. | 5 | Separation Processes |
The term spiral separator can refer to either a device for separating slurry components by density (wet spiral separators), or for a device for sorting particles by shape (dry spiral separators). | 5 | Separation Processes |
The Sudbury Neutrino Observatory (SNO), a underground observatory in Sudbury, Canada, is the other site where neutrino oscillation research was taking place in the late 1990s and early 2000s. The results from experiments at this observatory along with those at Super-Kamiokande are what helped solve the solar neutrino problem.
The SNO is also a heavy-water Cherenkov detector and designed to work the same way as the Super-Kamiokande. The Neutrinos when reacted with heavy water produce the blue Cherenkov light, signaling the detection of neutrinos to researchers and observers. | 3 | Nuclear Fusion |
In addition to unusual experimental properties, spin glasses are the subject of extensive theoretical and computational investigations. A substantial part of early theoretical work on spin glasses dealt with a form of mean-field theory based on a set of replicas of the partition function of the system.
An important, exactly solvable model of a spin glass was introduced by David Sherrington and Scott Kirkpatrick in 1975. It is an Ising model with long range frustrated ferro- as well as antiferromagnetic couplings. It corresponds to a mean-field approximation of spin glasses describing the slow dynamics of the magnetization and the complex non-ergodic equilibrium state.
Unlike the Edwards–Anderson (EA) model, in the system though only two-spin interactions are considered, the range of each interaction can be potentially infinite (of the order of the size of the lattice). Therefore, we see that any two spins can be linked with a ferromagnetic or an antiferromagnetic bond and the distribution of these is given exactly as in the case of Edwards–Anderson model. The Hamiltonian for SK model is very similar to the EA model:
where have same meanings as in the EA model. The equilibrium solution of the model, after some initial attempts by Sherrington, Kirkpatrick and others, was found by Giorgio Parisi in 1979 with the replica method. The subsequent work of interpretation of the Parisi solution—by M. Mezard, G. Parisi, M.A. Virasoro and many others—revealed the complex nature of a glassy low temperature phase characterized by ergodicity breaking, ultrametricity and non-selfaverageness. Further developments led to the creation of the cavity method, which allowed study of the low temperature phase without replicas. A rigorous proof of the Parisi solution has been provided in the work of Francesco Guerra and Michel Talagrand.
The formalism of replica mean-field theory has also been applied in the study of neural networks, where it has enabled calculations of properties such as the storage capacity of simple neural network architectures without requiring a training algorithm (such as backpropagation) to be designed or implemented.
More realistic spin glass models with short range frustrated interactions and disorder, like the Gaussian model where the couplings between neighboring spins follow a Gaussian distribution, have been studied extensively as well, especially using Monte Carlo simulations. These models display spin glass phases bordered by sharp phase transitions.
Besides its relevance in condensed matter physics, spin glass theory has acquired a strongly interdisciplinary character, with applications to neural network theory, computer science, theoretical biology, econophysics etc. | 7 | Magnetic Ordering |
In 1920, the British physicist, Francis William Aston, discovered that the mass of four hydrogen atoms is greater than the mass of one helium atom (He-4), which implied that energy can be released by combining hydrogen atoms to form helium. This provided the first hints of a mechanism by which stars could produce energy. Throughout the 1920s, Arthur Stanley Eddington became a major proponent of the proton–proton chain reaction (PP reaction) as the primary system running the Sun. Quantum tunneling was discovered by Friedrich Hund in 1929, and shortly afterwards Robert Atkinson and Fritz Houtermans used the measured masses of light elements to show that large amounts of energy could be released by fusing small nuclei.
Henry Norris Russell observed that the relationship in the Hertzsprung–Russell diagram suggested that a stars heat came from a hot core rather than from the entire star. Eddington used this to calculate that the temperature of the core would have to be about 40 million K. This became a matter of debate, because the value is much higher than astronomical observations that suggested about one-third to one-half that value. George Gamow introduced the mathematical basis for quantum tunnelling in 1928. In 1929 Atkinson and Houtermans provided the first estimates of the stellar fusion rate. They showed that fusion can occur at lower energies than previously believed, backing Eddingtons calculations.
Nuclear experiments began using a particle accelerator built by John Cockcroft and Ernest Walton at Ernest Rutherfords Cavendish Laboratory at the University of Cambridge. In 1932, Walton produced the first man-made fission by using protons from the accelerator to split lithium into alpha particles. The accelerator was then used to fire deuterons at various targets. Working with Rutherford and others, Mark Oliphant discovered the nuclei of helium-3 (helions) and tritium (tritons'), the first case of human-caused fusion.
Neutrons from fusion were first detected in 1933. The experiment involved the acceleration of protons towards a target at energies of up to 600,000 electron volts.
A theory verified by Hans Bethe in 1939 showed that beta decay and quantum tunneling in the Sun's core might convert one of the protons into a neutron and thereby produce deuterium rather than a diproton. The deuterium would then fuse through other reactions to further increase the energy output. For this work, Bethe won the 1967 Nobel Prize in Physics.
In 1938, Peter Thonemann developed a detailed plan for a pinch device, but was told to do other work for his thesis.
The first patent related to a fusion reactor was registered in 1946 by the United Kingdom Atomic Energy Authority. The inventors were Sir George Paget Thomson and Moses Blackman. This was the first detailed examination of the Z-pinch concept. Starting in 1947, two UK teams carried out experiments based on this concept. | 3 | Nuclear Fusion |
In 1955 Gilbert replaced the damping term in the Landau–Lifshitz (LL) equation by one that depends on the time derivative of the magnetization:
This is the Landau–Lifshitz–Gilbert (LLG) equation, where is the damping parameter, which is characteristic of the material. It can be transformed into the Landau–Lifshitz equation:
where
In this form of the LL equation, the precessional term depends on the damping term. This better represents the behavior of real ferromagnets when the damping is large. | 7 | Magnetic Ordering |
Hydroiodic acid (or hydriodic acid) is a colorless and aqueous solution of hydrogen iodide (HI). It is a strong acid, which is ionized completely in an aqueous solution. Concentrated solutions of hydroiodic acid are usually 48% to 57% HI. | 4 | Acids + Bases |
The following reporting guidelines were developed and published:
* MIRAGE MS guidelines for reporting mass spectrometry-based glycan analysis. These guidelines are based on the MIAPE guideline template, i.e. MIAPE-MS version 2.24.
* MIRAGE Sample preparation guidelines which are considered a common basis for any further MIRAGE reporting guidelines in order to keep the requirements for data analysis short and consistent.
* MIRAGE Glycan microarray guidelines for the comprehensive description of Glycan array experiments the reporting guidelines for glycan microarray analysis have been developed. In order to assist the authors to reporting in compliance with these guidelines, exemplar publications and a template with a data example is provided.
* MIRAGE Liquid chromatography guidelines for reporting of liquid chromatography (LC) glycan data. | 6 | Carbohydrates |
Cathodoluminescence is an optical and electromagnetic phenomenon in which electrons impacting on a luminescent material such as a phosphor, cause the emission of photons which may have wavelengths in the visible spectrum. A familiar example is the generation of light by an electron beam scanning the phosphor-coated inner surface of the screen of a television that uses a cathode ray tube. Cathodoluminescence is the inverse of the photoelectric effect, in which electron emission is induced by irradiation with photons. | 0 | Luminescence |
The embryo transfer procedure starts by placing a speculum in the vagina to visualize the cervix, which is cleansed with saline solution or culture media. A transfer catheter is loaded with the embryos and handed to the clinician after confirmation of the patient's identity. The catheter is inserted through the cervical canal and advanced into the uterine cavity. Several types of catheters are used for this process, however, there is good evidence that using a soft vs a hard transfer catheter can increase the chances of clinical pregnancy.
There is good and consistent evidence of benefit in ultrasound guidance, that is, making an abdominal ultrasound to ensure correct placement, which is 1–2 cm from the uterine fundus. There is evidence of a significant increase in clinical pregnancy using ultrasound guidance compared with only "clinical touch", as well as performing the transfer with hyaluronic acid enriched transfer media. Anesthesia is generally not required. Single embryo transfers in particular require accuracy and precision in placement within the uterine cavity. The optimal target for embryo placement, known as the maximal implantation potential (MIP) point, is identified using 3D/4D ultrasound. However, there is limited evidence that supports deposition of embryos in the midportion of the uterus.
After insertion of the catheter, the contents are expelled and the embryos are deposited. Limited evidence supports making trial transfers before performing the procedure with embryos. After expulsion, the duration that the catheter remains inside the uterus has no effect on pregnancy rates. Limited evidence suggests avoiding negative pressure from the catheter after expulsion. After withdrawal, the catheter is handed to the embryologist, who inspects it for retained embryos.
In the process of zygote intrafallopian transfer (ZIFT), eggs are removed from the woman, fertilised, and then placed in the woman's fallopian tubes rather than the uterus. | 1 | Cryobiology |
Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state. The verb form of sublimation is sublime, or less preferably, sublimate. Sublimate also refers to the product obtained by sublimation. The point at which sublimation occurs rapidly (for further details, see below) is called critical sublimation point, or simply sublimation point. Notable examples include sublimation of dry ice at room temperature and atmospheric pressure, and that of solid iodine with heating.
The reverse process of sublimation is deposition (also called desublimation), in which a substance passes directly from a gas to a solid phase, without passing through the liquid state.
All solids sublime, though most sublime at extremely low rates that are hardly detectable. At normal pressures, most chemical compounds and elements possess three different states at different temperatures. In these cases, the transition from the solid to the gas state requires an intermediate liquid state. The pressure referred to is the partial pressure of the substance, not the total (e.g. atmospheric) pressure of the entire system. Thus, any solid can sublime if its vapour pressure is higher than the surrounding partial pressure of the same substance, and in some cases, sublimes at an appreciable rate (e.g. water ice just below 0 °C).
For some substances, such as carbon and arsenic, sublimation from solid state is much more achievable than evaporation from liquid state and it is difficult to obtain them as liquids. This is because the pressure of their triple point in its phase diagram (which corresponds to the lowest pressure at which the substance can exist as a liquid) is very high.
Sublimation is caused by the absorption of heat which provides enough energy for some molecules to overcome the attractive forces of their neighbors and escape into the vapor phase. Since the process requires additional energy, sublimation is an endothermic change. The enthalpy of sublimation (also called heat of sublimation) can be calculated by adding the enthalpy of fusion and the enthalpy of vaporization. | 5 | Separation Processes |
Muscle is a naturally aligned organ, with individual muscle fibers packed together into larger units called muscle fascicles. The uniaxial alignment of muscle fibers allows them to simultaneously contract in the same direction and properly propagate force on the bones via the tendons. Approximately 45% of the human body is composed of muscle tissue, and this tissue can be classified into three different groups: skeletal muscle, cardiac muscle, and smooth muscle. Muscle plays a role in structure, stability, and movement in mammalian bodies. The basic unit for a muscle is a muscle fiber, which is made up of myofilaments actin and myosin. This muscle fiber contains sarcomeres which generate the force required for contraction.
A major focus of muscle tissue engineering is to create constructs with the functionality of native muscle and ability to contract. To this end, alignment of the tissue engineered construct is extremely important. It has been shown that cells grown on substrates with alignment cues form more robust muscle fibers. Several other design criteria considered in muscle tissue engineering include the scaffold porosity, stiffness, biocompatibility, and degradation timeline. Substrate stiffness should ideally be in the myogenic range, which has been shown to be 10-15 kPa.
The purpose of muscle tissue engineering is to reconstruct functional muscular tissue which has been lost via traumatic injury, tumor ablation, or functional damage caused by myopathies. Until now, the only method used to restore muscular tissue function and aesthetic was free tissue transfer. Full function is typically not restored, however, which results in donor site morbidity and volume deficiency. The success of tissue engineering as it pertains to the regeneration of skin, cartilage, and bone indicates that the same success will be found in engineering muscular tissue. Early innovations in the field yielded in vitro cell culturing and regeneration of muscle tissue which would be implanted in the body, but advances in recent years have shown that there may be potential for in vivo muscle tissue engineering using scaffolding. | 2 | Tissue Engineering |
By arranging each strand of EL wire into a shape slightly different from the previous one, it is possible to create animations using EL wire sequencers. EL wire sequencers are also used for costumes and have been used to create animations on various items such as kimono, purses, neckties, and motorcycle tanks. They are increasingly popular among artists, dancers, maker culture, and similar creative communities, such as exhibited in the annual Burning Man alt-culture festival. | 0 | Luminescence |
Speromagnetism is the equivalent of antiferromagnetism for a disordered system with random magnetic moments. It is defined by short range correlations of locked magnetic moments within small noncrystalline regions, without average long range correlations. Speromagnets do not have a net magnetic moment.
An example of a solid presenting speromagnetism is amorphous YFe and can be detected using Mössbauer spectroscopy. | 7 | Magnetic Ordering |
Polythionic acids are rarely encountered, but polythionates are common and important.
Polythionic acids have been identified in crater lakes. The phenomenon may be useful to predict volcanic activity. | 4 | Acids + Bases |
Clarification is a name for the method of separating fluid from solid particles. Often clarification is used along with flocculation to make the solid particles sink faster to the bottom of the clarification pool while fluid is obtained from the surface which is free of solid particles.
Thickening is the same as clarification except reverse. Solids that sink to the bottom are obtained and fluid is rejected from the surface.
The difference of these methods could be demonstrated with the methods used in waste water processing: in the clarification phase, sludge sinks to the bottom of the pool and clear water flows over the clear water grooves and continues its journey. The obtained sludge is then pumped into the thickeners, where sludge thickens farther and is then obtained to be pumped into digestion to be prepared into fertilizer. | 5 | Separation Processes |
Established in 1972, the focus of the research is on cryoinjury, cryosurgery, cryopreservation, lyophilization and hypothermia. Since 1985 the Institute has published the open access peer-reviewed scientific journal Problems of Cryobiology and Cryomedicine. | 1 | Cryobiology |
Enzymes used in decellularization treatments are used to break the bonds and interactions between nucleic acids, interacting cells through neighboring proteins, and other cellular components. Lipases, thermolysin, galactosidase, nucleases, and trypsin have all been used in the removal of cells. After a cell is lysed with a detergent, acid, physical pressure, etc., endonucleases and exonucleases can begin the degradation of the genetic material. Endonucleases cleave DNA and RNA in the middle of sequences. Benzoase, an endonuclease, produces multiple small nuclear fragments that can be further degraded and removed from the ECM scaffold. Exonucleases act at the end of DNA sequences to cleave the phosphodiester bonds and further degrade the nucleic acid sequences.
Enzymes such as trypsin act as proteases that cleave the interactions between proteins. Although trypsin can have adverse effects of collagen and elastin fibers of the ECM, using it in a time-sensitive manner controls any potential damage it could cause on the extracellular fibers. Dispase is used to prevent undesired aggregation of cells, which is beneficial in promoting their separating from the ECM scaffold. Experimentation has shown dispase to be most effective on the surface of a thin tissue, such as a lung in pulmonary tissue regeneration. To successfully remove deep cells of a tissue with dispase, mechanical agitation is often included in the process.
Collagenase is only used when the ECM scaffold product does not require an intact collagen structure. Lipases are commonly used when decellularized skin grafts are needed. Lipase acids function in decellularizing dermal tissues through delipidation and cleaving the interactions between heavily lipidized cells. The enzyme, α-galactosidase is a relevant treatment when removing the Gal epitope antigen from cell surfaces. | 2 | Tissue Engineering |
An apparent self-protective behaviour, known as "terminal burrowing", or "hide-and-die syndrome", occurs in the final stages of hypothermia. Those affected will enter small, enclosed spaces, such as underneath beds or behind wardrobes. It is often associated with paradoxical undressing. Researchers in Germany claim this is "obviously an autonomous process of the brain stem, which is triggered in the final state of hypothermia and produces a primitive and burrowing-like behavior of protection, as seen in hibernating mammals". This happens mostly in cases where temperature drops slowly. | 1 | Cryobiology |
EL wire sequencers can flash electroluminescent wire, or EL wire, in sequential patterns. EL wire requires a low-power, high-frequency driver to cause the wire to illuminate. Most EL wire drivers simply light up one strand of EL wire in a constant-on mode, and some drivers may additionally have a blink or strobe mode. A sound-activated driver will light EL wire in synchronization to music, speech, or other ambient sound, but an EL wire sequencer will allow multiple lengths of EL wire to be flashed in a desired sequence. The lengths of EL wire can all be the same color, or a variety of colors.
The images above show a sign that displays a telephone number, where the numbers were formed using different colors of EL wire. There are ten numbers, each of which is connected to a different channel of the EL wire sequencer.
Like EL wire drivers, sequencers are rated to drive (or power) a range or specific length of EL wire. For example, using a sequencer rated for 1.5 to 14 meters (5 to 45 feet), if less than 1.5m is used, there is a risk of burning out the sequencer, and if more than 14m is used, the EL wire will not light as brightly as intended.
There are commercially available EL wire sequencers capable of lighting three, four, five, or ten lengths of EL wire. There are professional and experimental sequencers with many more than ten channels, but for most applications, ten channels is enough. Sequencers usually have options for changing the speed, reversing, changing the order of the sequence, and sometimes, to change whether the first wires remain lit or go off as the rest of the wires in the sequence are lit. EL wire sequencers tend to be smaller than a pack of cigarettes and most are powered by batteries. This versatility lends to the sequencers' use at nighttime events where mains electricity is not available. | 0 | Luminescence |
In Canada, one cycle of IVF treatment can cost between $7,750 to $12,250 CAD, and medications alone can cost between $2,500 to over $7,000 CAD. The funding mechanisms that influence accessibility in Canada vary by province and territory, with some provinces providing full, partial or no coverage.
New Brunswick provides partial funding through their Infertility Special Assistance Fund – a one time grant of up to $5,000. Patients may only claim up to 50% of treatment costs or $5,000 (whichever is less) occurred after April 2014. Eligible patients must be a full-time New Brunswick resident with a valid Medicare card and have an official medical infertility diagnosis by a physician.
In December 2015, the Ontario provincial government enacted the Ontario Fertility Program for patients with medical and non-medical infertility, regardless of sexual orientation, gender or family composition. Eligible patients for IVF treatment must be Ontario residents under the age of 43 and have a valid Ontario Health Insurance Plan card and have not already undergone any IVF cycles. Coverage is extensive, but not universal. Coverage extends to certain blood and urine tests, physician/nurse counselling and consultations, certain ultrasounds, up to two cycle monitorings, embryo thawing, freezing and culture, fertilisation and embryology services, single transfers of all embryos, and one surgical sperm retrieval using certain techniques only if necessary. Drugs and medications are not covered under this Program, along with psychologist or social worker counselling, storage and shipping of eggs, sperm or embryos, and the purchase of donor sperm or eggs. | 1 | Cryobiology |
Phosphor banded stamps first appeared in 1959 as guides for machines to sort mail. Around the world many varieties exist with different amounts of banding. Postage stamps are sometimes collected by whether or not they are "tagged" with phosphor (or printed on luminescent paper). | 0 | Luminescence |
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