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Ultraviolet illumination can be produced from longer wavelengths using non-linear optical materials. These can be a second harmonic generator. They must have a suitable birefringence in order to phase match the output frequency doubled UV light. One compound commercially used is L-arginine phosphate monohydrate known as LAP. Research is underway for substances that are very non-linear, have a suitable birefringence, are transparent in the spectrum and have a high degree of resistance to damage from lasers. | 8 | Ultraviolet Radiation |
Multi-layered OFM devices, reinforced with synthetic polymer were first described in 2008 and in the scientific literature in 2010. These devices, termed ‘reinforced biologics’ have been designed for applications in the surgical repair of hernia as an alternative to synthetic surgical mesh (a mesh prosthesis). OFM reinforced biologics are distributed in the US by Tela Bio Inc. Clinical studies have shown that OFM reinforced biologics have lower hernia recurrence rates versus synthetic hernia meshes or biologics such as acellular dermis. | 2 | Tissue Engineering |
In these applications, the phosphor is directly added to the plastic used to mold the toys, or mixed with a binder for use as paints.
ZnS:Cu phosphor is used in glow-in-the-dark cosmetic creams frequently used for Halloween make-ups.
Generally, the persistence of the phosphor increases as the wavelength increases.
See also lightstick for chemiluminescence-based glowing items. | 0 | Luminescence |
A gaur that died of natural causes had some skin cells frozen and added to the San Diego Frozen Zoo. Eight years later, DNA from these cells was inserted into a domestic-cow egg to create an embryo (trans-species cloning), which was then implanted in a domestic cow (Bos taurus). On 8 January 2001, the gaur, named Noah, was born in Sioux Center, Iowa. Noah was initially healthy, but the next day, he came down with clostridial enteritis, and died of dysentery within 48 hours of birth. This is not uncommon in uncloned animals, and the researchers did not think it was due to the cloning. | 1 | Cryobiology |
The probability that fusion occurs is greatly increased compared to the classical picture, thanks to the smearing of the effective radius as the de Broglie wavelength as well as quantum tunneling through the potential barrier. To determine the rate of fusion reactions, the value of most interest is the cross section, which describes the probability that particles will fuse by giving a characteristic area of interaction. An estimation of the fusion cross-sectional area is often broken into three pieces:
where is the geometric cross section, is the barrier transparency and is the reaction characteristics of the reaction.
is of the order of the square of the de Broglie wavelength where is the reduced mass of the system and is the center of mass energy of the system.
can be approximated by the Gamow transparency, which has the form: where is the Gamow factor and comes from estimating the quantum tunneling probability through the potential barrier.
contains all the nuclear physics of the specific reaction and takes very different values depending on the nature of the interaction. However, for most reactions, the variation of is small compared to the variation from the Gamow factor and so is approximated by a function called the astrophysical S-factor, , which is weakly varying in energy. Putting these dependencies together, one approximation for the fusion cross section as a function of energy takes the form:
More detailed forms of the cross-section can be derived through nuclear physics-based models and R-matrix theory. | 3 | Nuclear Fusion |
Laboratories have developed grading methods to judge oocyte and embryo quality. In order to optimise pregnancy rates, there is significant evidence that a morphological scoring system is the best strategy for the selection of embryos. Since 2009 where the first time-lapse microscopy system for IVF was approved for clinical use, morphokinetic scoring systems has shown to improve to pregnancy rates further. However, when all different types of time-lapse embryo imaging devices, with or without morphokinetic scoring systems, are compared against conventional embryo assessment for IVF, there is insufficient evidence of a difference in live-birth, pregnancy, stillbirth or miscarriage to choose between them. A small prospectively randomized study in 2016 reported poorer embryo quality and more staff time in an automated time-lapse embryo imaging device compared to conventional embryology. Active efforts to develop a more accurate embryo selection analysis based on Artificial Intelligence and Deep Learning are underway. Embryo Ranking Intelligent Classification Algorithm (ERICA), is a clear example. This Deep Learning software substitutes manual classifications with a ranking system based on an individual embryo's predicted genetic status in a non-invasive fashion. Studies on this area are still pending and current feasibility studies support its potential. | 1 | Cryobiology |
Many non-governmental organizations (NGOs) have been formed in the areas with the highest occurrence of acid attacks to combat such attacks. Bangladesh has its Acid Survivors Foundation, which offers acid victims legal, medical, counseling, and monetary assistance in rebuilding their lives. Similar institutions exist in Uganda, which has its own Acid Survivors Foundation, and in Cambodia which uses the help of Cambodian Acid Survivors Charity. NGOs provide rehabilitation services for survivors while acting as advocates for social reform, hoping to increase support and awareness for acid assault.
In Bangladesh, the Acid Survivors Foundation, Nairpokkho, Action Aid, and the Bangladesh Rural Advancement Committee's Community Empowerment & Strengthening Local Institutions Programme assist survivors. The Depilex Smileagain Foundation and The Acid Survivors Foundation in Pakistan operates in Islamabad, offering medical, psychological and rehabilitation support. The Acid Survivors Foundation in Uganda operates in Kampala and provides counseling and rehabilitation treatment to victims, as well as their families. The LICADHO, the Association of the Blind in Cambodia, and the Cambodian Acid Survivors Charity assist survivors of acid attacks. The Acid Survivors Foundation India operates from different centres with national headquarters at Kolkata and chapters at Delhi and Mumbai.
Acid Survivors Trust International (UK registered charity no. 1079290) provides specialist support to its sister organizations in Africa and Asia. Acid Survivors Trust International is the only international organisation whose sole purpose is to end acid violence. The organisation was founded in 2002 and now works with a network of six Acid Survivors Foundations in Bangladesh, Cambodia, India, Nepal, Pakistan and Uganda that it has helped to form. Acid Survivors Trust International has helped to provide medical expertise and training to partners, raised valuable funds to support survivors of acid attacks and helped change laws. A key role for ASTI is to raise awareness of acid violence to an international audience so that increased pressure can be applied to governments to introduce stricter controls on the sale and purchase of acid.
Indian acid attack survivor Shirin Juwaley founded the Palash Foundation to help other survivors with psychosocial rehabilitation. She also spearheads research into social norms of beauty and speaks publicly as an advocate for the empowerment of all victims of disfigurement and discrimination. In 2011, the principal of an Indian college refused to have Juwaley speak at her school for fear that Juwaley's story of being attacked by her husband would make students "become scared of marriage". | 4 | Acids + Bases |
Fung was born in Jiangsu Province, China in 1919. He earned a bachelors degree in 1941 and a masters degree in 1943 from the National Central University (later renamed Nanjing University in mainland China and reinstated in Taiwan), and earned a Ph.D. from the California Institute of Technology in 1948. Fung was Professor Emeritus and Research Engineer at the University of California San Diego. He published prominent texts along with Pin Tong who was then at Hong Kong University of Science & Technology. Fung died at the Jacobs Medical Center in San Diego, California, aged 100, on December 15, 2019.
Fung was married to Luna Yu Hsien-Shih, a former mathematician and cofounder of the UC San Diego International Center, until her death in 2017. The couple raised two children. | 2 | Tissue Engineering |
For ice, recrystallization refers to the growth of larger crystals at the expense of smaller ones. Some biological antifreeze proteins have been shown to inhibit this process, and the effect may be relevant in freezing-tolerant organisms. | 5 | Separation Processes |
The prototypical example of a spin chain is the Heisenberg model, described by Werner Heisenberg in 1928. This models a one-dimensional lattice of fixed particles with spin 1/2. A simple version (the antiferromagnetic XXX model) was solved, that is, the spectrum of the Hamiltonian of the Heisenberg model was determined, by Hans Bethe using the Bethe ansatz.
Now the term Bethe ansatz is used generally to refer to many ansatzes used to solve exactly solvable problems in spin chain theory such as for the other variations of the Heisenberg model (XXZ, XYZ), and even in statistical lattice theory, such as for the six-vertex model.
Another spin chain with physical applications is the Hubbard model, introduced by John Hubbard in 1963.
This model was shown to be exactly solvable by Elliott Lieb and Fa-Yueh Wu in 1968.
Another example of (a class of) spin chains is the Gaudin model, described and solved by Michel Gaudin in 1976 | 7 | Magnetic Ordering |
The molar concentration of hydronium or ions determines a solution's pH according to
where M = mol/L. The concentration of hydroxide ions analogously determines a solution's pOH. The molecules in pure water auto-dissociate into aqueous protons and hydroxide ions in the following equilibrium:
In pure water, there is an equal number of hydroxide and ions, so it is a neutral solution. At , pure water has a pH of 7 and a pOH of 7 (this varies when the temperature changes: see self-ionization of water). A pH value less than 7 indicates an acidic solution, and a pH value more than 7 indicates a basic solution. | 4 | Acids + Bases |
Pulses and beans are the main dietary sources (although green beans, canned lentils, sprouted mung beans, tofu (not silken), and tempeh contain comparatively low amounts). Supplements of the enzyme alpha-galactosidase may reduce symptoms, assuming the enzyme product does not contain other FODMAPs, such as polyol artificial sweeteners. | 6 | Carbohydrates |
A sized screen fraction with a size range coefficient (d95/d5) of 2-5 (optimal 2-3) is fed onto a vibratory feeder which has the function to create a mono-layer, by pre-accelerating the particles. A common misunderstanding in plant design is, that you can use the vibratory feeder to discharge from a buffer bunker but a separate units needs to be applied, since the feed distribution is very important to the efficiency of the sensor-based sorter and different loads on the feeder change its position and vibration characteristics. | 5 | Separation Processes |
Tanning facilities are ubiquitous in the US, although the figures are in decline. In a study in the US published in 2002, there was a higher density in colder areas with a lower median income and higher proportion of whites. A study in 1997 found an average of 50.3 indoor-tanning facilities in 20 US cities (13.89 facilities for every 100,000 residents); the highest was 134 in Minneapolis, MN, and the lowest four in Honolulu, Hawaii. In 2006 a study of 116 cities in the US found 41.8 facilities on average, a higher density than either Starbucks or McDonalds. Of the countrys 125 top colleges and universities in 2014, 12% had indoor-tanning facilities on campus and 42.4% in off-campus housing, 96% of the latter free of charge to the tenants.
There are fewer professional salons than tanning facilities; the latter includes tanning beds in gyms, spas and similar. According to the FDA, citing the Indoor Tanning Association, there were 25,000 tanning salons in 2010 in the US (population 308.7 million in 2010). Mailing-list data suggest there were 18,200 in September 2008 and 12,200 in September 2015, a decline of 30 percent. According to Chris Sternberg of the American Suntanning Association, the figures are 18,000 in 2009 and 9,500 in 2016.
The South West Public Health Observatory found 5,350 tanning salons in the UK in 2009: 4,492 in England (population 52.6 million in 2010), 484 in Scotland (5.3 million), 203 in Wales (3 million) and 171 in Northern Ireland (1.8 million). | 8 | Ultraviolet Radiation |
There is evidence that immunological mechanisms may injure hypothermically perfused kidneys after reimplantation if the perfusate contained specific antibody. Cross described two pairs of human cadaver kidneys that were perfused simultaneously with cryoprecipitated plasma containing type specific HLA antibody to one of the pairs. Both these kidneys suffered early arterial thrombosis. Light described similar hyperacute rejection following perfusion storage and showed that the cryoprecipitated plasma used contained cytotoxic IgM antibody. This potential danger of using cryoprecipitated plasma was demonstrated experimentally by Filo who perfused dog kidneys for 24 hours with specifically sensitised cryoprecipitated dog plasma and found that he could induce glomerular and vascular lesions with capillary engorgement, endothelial swelling, infiltration by polymorphonuclear leucocytes and arterial thrombosis. Immunofluorescent microscopy demonstrated specific binding of IgG along endothelial surfaces, in glomeruli, and also in vessels. After reimplantation, complement fixation and tissue damage occurred in a similar pattern. There was some correlation between the severity of the histological damage and subsequent function of the kidneys.
Many workers have attempted to prevent kidneys rewarming during reimplantation but only Cohen has described using a system of active cooling. Measurements of lysosomal enzyme release from kidneys subjected to sham anastomoses, when either in or out of the cooling system, demonstrated how sensitive kidneys were to rewarming after a period of cold storage, and confirmed the effectiveness of the cooling system in preventing enzyme release. A further factor in minimising injury at the reimplantation operations may have been that the kidneys were kept at 7 °C within the cooling coil, which was within a degree of the temperature used during perfusion storage, so that the kidneys were not subjected to the greater changes in temperature that would have occurred if ice cooling had been used.
Dempster described using slow release of the vascular clamps at the end of kidney reimplantation operations to avoid injuring the kidney, but other workers have not mentioned whether or not they used this manoeuvre. After Cohen found vascular injury with intra renal bleeding after 3 days of perfusion storage, a technique of slow revascularisation was used for all subsequent experiments, with the aim of giving the intra- renal vessels time to recover their tone sufficiently to prevent full systolic pressure being applied to the fragile glomerular vessels. The absence of gross vascular injury in his later perfusions may be attributable to the use of this manoeuvre. | 1 | Cryobiology |
The pioneers to the derivation of the rate of pycnonuclear fusion in one-component plasma (OCP) were Edwin Salpeter and David Van-Horn, with their article published in 1969. Their approach used a semiclassical method to solve the Schrödinger equation by using the Wentzel-Kramers-Brillouin (WKB) approximation, and Wigner-Seitz (WS) spheres. Their model is heavily simplified, and whilst it is primitive, is required to understand other approaches which largely extrapolated on the works of Salpeter & Van Horn. They employed the WS spheres to simplify the OCP into regions containing one ion each, with the ions situated on the vertices of a BCC crystal lattice. Then, using the WKB approximation, they resolved the effect of quantum tunnelling on the fusing nuclei. Extrapolating this to the entire lattice allowed them to arrive at their formula for the rate of pycnonuclear fusion:
where is the density of the plasma, is the mean molecular weight per electron (atomic nucleus), is a constant equal to and serves as a conversion factor from atomic mass units to grams, and represents the thermal average of the pairwise reaction probability.
However, the big fault of the method proposed by Salpeter & Van-Horn is that they neglected the dynamic model of the lattice. This was improved upon by Schramm and Koonin in 1990. In their model, they found that the dynamic model cannot be neglected, but it is possible that the effects caused by the dynamicity can be cancelled out. | 3 | Nuclear Fusion |
* Autologous MDSC Injections to Treat Urinary Incontinence: an in vivo injection technique for pure stress incontinence in female subjects in which defective muscle cells were replaced with stem cells that would differentiate to become functioning smooth muscle cells in the urinary sphincter
* Vascular Smooth Muscle regeneration using induced pluripotent stem cells (iPSCs); an in vitro technique in which iPSCs were differentiated into proliferative smooth muscle cells using a nanofibrous scaffold.
* Formation of coiled three-dimensional (3D) cellular constructs containing smooth muscle-like cells differentiated from dedifferentiated fat (DFAT) cells: an in vitro technique for controlling the 3D organization of smooth muscle cells in which DFAT cells are suspended in a mixture of extracellular proteins with optimized stiffness so that they differentiate into smooth muscle-like cells with specific 3D orientation; a muscle tissue engineered construct for a smooth muscle cell precursor | 2 | Tissue Engineering |
One force capable of confining the fuel well enough to satisfy the Lawson criterion is gravity. The mass needed, however, is so great that gravitational confinement is only found in stars—the least massive stars capable of sustained fusion are red dwarfs, while brown dwarfs are able to fuse deuterium and lithium if they are of sufficient mass. In stars heavy enough, after the supply of hydrogen is exhausted in their cores, their cores (or a shell around the core) start fusing helium to carbon. In the most massive stars (at least 8–11 solar masses), the process is continued until some of their energy is produced by fusing lighter elements to iron. As iron has one of the highest binding energies, reactions producing heavier elements are generally endothermic. Therefore, significant amounts of heavier elements are not formed during stable periods of massive star evolution, but are formed in supernova explosions. Some lighter stars also form these elements in the outer parts of the stars over long periods of time, by absorbing energy from fusion in the inside of the star, by absorbing neutrons that are emitted from the fusion process.
All of the elements heavier than iron have some potential energy to release, in theory. At the extremely heavy end of element production, these heavier elements can produce energy in the process of being split again back toward the size of iron, in the process of nuclear fission. Nuclear fission thus releases energy that has been stored, sometimes billions of years before, during stellar nucleosynthesis. | 3 | Nuclear Fusion |
For spin and a parameter for the deformation from the XXX model, the BAE (Bethe ansatz equation) is
Notably, for these are precisely the BAEs for the six-vertex model, after identifying , where is the anisotropy parameter of the six-vertex model. This was originally thought to be coincidental until Baxter showed the XXZ Hamiltonian was contained in the algebra generated by the transfer matrix , given exactly by | 7 | Magnetic Ordering |
Superparamagnetism sets a limit on the storage density of hard disk drives due to the minimum size of particles that can be used. This limit on areal-density is known as the superparamagnetic limit.
* Older hard disk technology uses longitudinal recording. It has an estimated limit of 100 to 200 Gbit/in.
* Current hard disk technology uses perpendicular recording. drives with densities of approximately 1 Tbit/in are available commercially. This is at the limit for conventional magnetic recording that was predicted in 1999.
* Future hard disk technologies currently in development include: heat-assisted magnetic recording (HAMR) and microwave-assisted magnetic recording (MAMR), which use materials that are stable at much smaller sizes. They require localized heating or microwave excitation before the magnetic orientation of a bit can be changed. Bit-patterned recording (BPR) avoids the use of fine-grained media and is another possibility. In addition, magnetic recording technologies based on topological distortions of the magnetization, known as skyrmions, have been proposed. | 7 | Magnetic Ordering |
Ovarian hyperstimulation is the stimulation to induce development of multiple follicles of the ovaries. It should start with response prediction by e.g. age, antral follicle count and level of anti-Müllerian hormone. The resulting prediction of e.g. poor or hyper-response to ovarian hyperstimulation determines the protocol and dosage for ovarian hyperstimulation.
Ovarian hyperstimulation also includes suppression of spontaneous ovulation, for which two main methods are available: Using a (usually longer) GnRH agonist protocol or a (usually shorter) GnRH antagonist protocol. In a standard long GnRH agonist protocol the day when hyperstimulation treatment is started and the expected day of later oocyte retrieval can be chosen to conform to personal choice, while in a GnRH antagonist protocol it must be adapted to the spontaneous onset of the previous menstruation. On the other hand, the GnRH antagonist protocol has a lower risk of ovarian hyperstimulation syndrome (OHSS), which is a life-threatening complication.
For the ovarian hyperstimulation in itself, injectable gonadotropins (usually FSH analogues) are generally used under close monitoring. Such monitoring frequently checks the estradiol level and, by means of gynecologic ultrasonography, follicular growth. Typically approximately 10 days of injections will be necessary.
When stimulating ovulation after suppressing endogenous secretion, it is necessary to supply exogenous gonadotropines. The most common one is the human menopausal gonadotropin (hMG), which is obtained by donation of menopausal women. Other pharmacological preparations are FSH+LH or coripholitropine alpha. | 1 | Cryobiology |
In 1937, the explanations for the light emission have favored electrical discharges. The first ideas have been about the charge separation in cavitation bubbles, which have been seen as spherical capacitors with charges at the center and the wall.
At the collapse, the capacitance decreases and voltage increases until electric breakdown occurs. A further suggestion was a charge separation by enhancing charge fluctuations on the bubble wall, however, a breakdown should take place during the expansion phase of the bubble dynamics.
These discharge theories have to assume that the emitting bubble undergoes an asymmetric collapse, because a symmetric charge distribution cannot radiate light. | 0 | Luminescence |
Brain-on-a-chip devices create an interface between neuroscience and microfluidics by: 1) improving culture viability; 2) supporting high-throughput screening; 3) modeling organ-level physiology and disease in vitro/ex vivo, and 4) adding high precision and tunability of microfluidic devices. Brain-on-a-chip devices span multiple levels of complexity in terms of cell culture methodology. Devices have been made using platforms that range from traditional 2D cell culture to 3D tissues in the form of organotypic brain slices.
Organotypic brain slices are an in vitro model that replicates in vivo physiology with additional throughput and optical benefits, thus pairing well with microfluidic devices. Brain slices have advantages over primary cell culture in that tissue architecture is preserved and multicellular interactions can still occur. There is flexibility in their use, as slices can be used acutely (less than 6 hours after slice harvesting) or cultured for later experimental use. Because organotypic brain slices can maintain viability for weeks, they allow for long-term effects to be studied. Slice-based systems also provide experimental access with precise control of extracellular environments, making it a suitable platform for correlating disease with neuropathological outcomes. Because approximately 10 to 20 slices can be extracted from a single brain, animal usage is significantly reduced relative to in vivo studies. Organotypic brain slices can be extracted and cultured from multiple animal species (e.g. rats), but also from humans.
Microfluidic devices have been paired with organotypic slices to improve culture viability. The standard procedure for culturing organotypic brain slices (around 300 microns in thickness) uses semi-porous membranes to create an air-medium interface, but this technique results in diffusion limitations of nutrients and dissolved gases. Because microfluidic systems introduce laminar flow of these necessary nutrients and gases, transport is improved and higher tissue viability can be achieved. In addition to keeping standard slices viable, brain-on-a-chip platforms have allowed the successful culturing of thicker brain slices (approximately 700 microns), despite a significant transport barrier due to thickness. As thicker slices retain more native tissue architecture, this allows brain-on-a-chip devices to achieve more "in vivo-like" characteristics without sacrificing cell viability. Microfluidic devices support high-throughput screening and toxicological assessments in both 2D and slice cultures, leading to the development of novel therapeutics targeted for the brain. One device was able to screen the drugs pitavastatin and irinotecan combinatorically in glioblastoma multiform (the most common form of human brain cancer). These screening approaches have been combined with the modeling of the blood-brain barrier (BBB), a significant hurdle for drugs to overcome when treating the brain, allowing for drug efficacy across this barrier to be studied in vitro. Microfluidic probes have been used to deliver dyes with high regional precision, making way for localized microperfusion in drug applications. Microfluidic BBB in vitro models replicate a 3D environment for embedded cells (which provides precise control of cellular and extracellular environment), replicate shear stress, have more physiologically relevant morphology in comparison to 2D models, and provide easy incorporation of different cell types into the device. Because microfluidic devices can be designed with optical accessibility, this also allows for the visualization of morphology and processes in specific regions or individual cells. Brain-on-a-chip systems can model organ-level physiology in neurological diseases, such as Alzheimers disease, Parkinsons disease, and multiple sclerosis more accurately than with traditional 2D and 3D cell culture techniques. The ability to model these diseases in a way that is indicative of in vivo conditions is essential for the translation of therapies and treatments. Additionally, brain-on-a-chip devices have been used for medical diagnostics, such as in biomarker detection for cancer in brain tissue slices.
Brain-on-a-chip devices can cause shear stress on cells or tissue due to flow through small channels, which can result in cellular damage. These small channels also introduce susceptibility to the trapping of air bubbles that can disrupt flow and potentially cause damage to the cells. The widespread use of PDMS (polydimethylsiloxane) in brain-on-a-chip devices has some drawbacks. Although PDMS is cheap, malleable, and transparent, proteins and small molecules can be absorbed by it and later leech at uncontrolled rates.
Despite the progress in microfluidic BBB devices, these devices are often too technically complex, require highly specialized setups and equipment, and are unable to detect temporal and spatial differences in the transport kinetics of substances that migrate across cellular barriers. Also, direct measurements of permeability in these models are limited due to the limited perfusion and complex, poorly defined geometry of the newly formed microvascular network. | 2 | Tissue Engineering |
Single particle testing is an extensive but powerful laboratory procedure developed by Tomra. Outo of a sample set of multiple hundreds of fragments in the size range 30-60mm are measured individually on each of the available detection technologies. After recording of the raw data, all the fragments are comminute and assayed individually which then allows plotting of the liberation function of the sample set and in addition, the detection efficiency of each detection technology in combination with the calibration method applied. This makes the evaluation of detection and calibration and subsequently the selection of the most powerful combination possible. This analysis is possible to be applied on quarters or half sections of drill core. | 5 | Separation Processes |
The magnetocrystalline anisotropy energy is generally represented as an expansion in powers of the direction cosines of the magnetization. The magnetization vector can be written , where is the saturation magnetization. Because of time reversal symmetry, only even powers of the cosines are allowed. The nonzero terms in the expansion depend on the crystal system (e.g., cubic or hexagonal). The order of a term in the expansion is the sum of all the exponents of magnetization components, e.g., is second order. | 7 | Magnetic Ordering |
Glucosinolates are natural components of many pungent plants such as mustard, cabbage, and horseradish. The pungency of those plants is due to mustard oils produced from glucosinolates when the plant material is chewed, cut, or otherwise damaged. These natural chemicals most likely contribute to plant defence against pests and diseases, and impart a characteristic bitter flavor property to cruciferous vegetables. | 6 | Carbohydrates |
Stripping is a physical separation process where one or more components are removed from a liquid stream by a vapor stream. In industrial applications the liquid and vapor streams can have co-current or countercurrent flows. Stripping is usually carried out in either a packed or trayed column. | 5 | Separation Processes |
Lume is a short term for the luminous phosphorescent glowing solution applied on watch dials. There are some people who "relume" watches, or replace faded lume. Formerly, lume consisted mostly of radium; however, radium is radioactive and has been mostly replaced on new watches by less bright, but less toxic compounds. After radium was effectively outlawed in 1968, tritium became the luminescent material of choice, because, while still radioactive, it is much less potent than radium, tritium being about as radioactive as an x-ray, the decrease in radioactivity resulting from a diminishment of strength and quantity of the beta waves that are given off by tritium as an element.
Common pigments used in lume include the phosphorescent pigments zinc sulfide and strontium aluminate. Use of zinc sulfide for safety related products dates back to the 1930s. However, the development of strontium oxide aluminate, with a luminance approximately 10 times greater than zinc sulfide, has relegated most zinc sulfide based products to the novelty category. Strontium oxide aluminate based pigments are now used in exit signs, pathway marking, and other safety related signage.
Strontium aluminate based afterglow pigments are marketed under brandnames like Super-LumiNova, Watchlume Co, NoctiLumina, and Glow in the Dark (Phosphorescent) Technologies. | 0 | Luminescence |
The latest generation of the radioluminescent materials is based on tritium, a radioactive isotope of hydrogen with half-life of 12.32 years that emits very low-energy beta radiation. The devices are similar to a fluorescent tube in construction, as they consist of a hermetically sealed (usually borosilicate-glass) tube, coated inside with a phosphor, and filled with tritium. They are known under many names – e.g. gaseous tritium light source (GTLS), traser, betalight.
Tritium light sources are most often seen as "permanent" illumination for the hands of wristwatches intended for diving, nighttime, or tactical use. They are additionally used in glowing novelty keychains, in self-illuminated exit signs, and formerly in fishing lures. They are favored by the military for applications where a power source may not be available, such as for instrument dials in aircraft, compasses, lights for map reading, and sights for weapons.
Tritium lights are also found in some old rotary dial telephones, though due to their age they no longer produce a useful amount of light. | 0 | Luminescence |
Galactogen has been reported in the albumen gland of pulmonate snails such as Helix pomatia, Limnaea stagnalis, Oxychilus cellarius, Achatina fulica, Aplexa nitens and Otala lactea, Bulimnaea megasoma, Ariolimax columbianis, Ariophanta, Biomphalaria glabrata, and Strophochelius oblongus. This polysaccharide was also identified in the Caenogastropoda Pila virens and Viviparus, Pomacea canaliculata, and Pomacea maculata.
In adult gastropods, galactogen is confined to the albumen gland, showing a large variation in content during the year and reaching a higher peak in the reproductive season. During the reproductive season, this polysaccharide is rapidly restored in the albumen gland after being transferred to the eggs, decreasing its total amount only after repeated ovipositions. In Pomacea canaliculata snails, galactogen would act, together with perivitellins, as a main limiting factor of reproduction. This polysaccharide has been identified in the Golgi zone of the secretory cells from the albumen gland in the form of discrete granules 200 Å in diameter. The appearance of galactogen granules within the secretory globules suggests that this is the site of biosynthesis of the polysaccharide.
Apart from the albumen gland, galactogen is also found as a major component of the perivitelline fluid from the snail eggs, comprising the main energy source for the developing embryo. | 6 | Carbohydrates |
Sensor-based ore sorting is in comparison to other coarse particle separation technologies relatively cheap. While the costs for the equipment itself are relatively high in capital expenditure and operating costs, the absence of extensive infrastructure in a system results in operating costs that are to be compared to jigging. The specific costs are very much depending on the average particle size of the feed and on the ease of the separation. Coarser particles imply higher capacity and thus less costs. Detailed costing can be conducted after the mini-bulk stage in the technical feasibility evaluation.
Prejudice against waste rejection with sensor-based sorting widely spread, that the loss of valuables, thus the recovery penalty of this process, supersedes the potential downstream cost savings and is therefore economically not viable. It must be noted that for waste rejection the aim for the separation with sensor-based ore sorting must be put onto maximum recovery, which means that only low grade or barren waste is rejected because the financial feasibility is very much sensitive to that factor. Nevertheless, through the rejection of waste before comminution and concentration steps, recovery can be often increased in the downstream process, meaning that the overall recovery is equal or even higher than the one in the base case, meaning that instead of losing product, additional product can be produced, which adds the additional revenue to the cost savings on the positive side in the cash flow.
If the rejected material is replaced with additional higher grade material, the main economic benefit unfolds through the additional production. It implies, that in conjunction with sensor-based ore sorting, the capacity of the crushing station is increased, to allow for the additional mass-flow that is subsequently taken out by the sensor-based ore sorters as waste. | 5 | Separation Processes |
Glucosinolates occur as secondary metabolites of almost all plants of the order Brassicales. This includes the economically important family Brassicaceae as well as Capparaceae and Caricaceae.
Outside of the Brassicales, the genera Drypetes and Putranjiva in the family Putranjivaceae, are the only other known occurrence of glucosinolates.
Glucosinolates occur in various edible plants such as cabbage (white cabbage, Chinese cabbage, broccoli), Brussels sprouts, watercress, horseradish, capers, and radishes where the breakdown products often contribute a significant part of the distinctive taste. The glucosinolates are also found in seeds of these plants. | 6 | Carbohydrates |
Numerous studies have been dedicated towards the development of effective methods to enable cardiac tissue regeneration in patients after ischemic heart disease. An emerging approach to answer the problems related to ischemic tissue repair is through the use of stem cell-based therapy. However, the actual mechanism due to which this stem cell-based therapy has generative effects on cardiac function is still under investigation. Even though numerous methods have been studied for cell administration, the efficiency of the number of cells retained in the beating heart after implantation is still very low. A promising approach to overcome this problem is through the use of cell microencapsulation therapy which has shown to enable a higher cell retention as compared to the injection of free stem cells into the heart.
Another strategy to improve the impact of cell based encapsulation technique towards cardiac regenerative applications is through the use of genetically modified stem cells capable of secreting angiogenic factors such as vascular endothelial growth factor (VEGF) which stimulate neovascularization and restore perfusion in the damaged ischemic heart. An example of this is shown in the study by Zang et al. where genetically modified xenogeneic CHO cells expressing VEGF were encapsulated in alginate-polylysine-alginate microcapsules and implanted into rat myocardium. It was observed that the encapsulation protected the cells from an immunoresponse for three weeks and also led to an improvement in the cardiac tissue post-infarction due to increased angiogenesis. | 2 | Tissue Engineering |
Catabolism is the metabolic reaction which cells undergo to break down larger molecules, extracting energy. There are two major metabolic pathways of monosaccharide catabolism: glycolysis and the citric acid cycle.
In glycolysis, oligo- and polysaccharides are cleaved first to smaller monosaccharides by enzymes called glycoside hydrolases. The monosaccharide units can then enter into monosaccharide catabolism. A 2 ATP investment is required in the early steps of glycolysis to phosphorylate Glucose to Glucose 6-Phosphate (G6P) and Fructose 6-Phosphate (F6P) to Fructose 1,6-biphosphate (FBP), thereby pushing the reaction forward irreversibly. In some cases, as with humans, not all carbohydrate types are usable as the digestive and metabolic enzymes necessary are not present. | 6 | Carbohydrates |
Recreation of the prostate epithelium is motivated by evidence suggesting it to be the site of nucleation in cancer metastasis. These systems essentially serve as the next step in the development of cells cultured from mice to two and subsequently three-dimensional human cell culturing. PDMS developments have enabled the creation of microfluidic systems that offer the benefit of adjustable topography, gas and liquid exchange, as well as an ease of observation via conventional microscopy.
Researchers at the University of Grenoble Alpes have outlined a methodology that utilizes such a microfluidic system in the attempt to construct a viable Prostate epithelium model. The approach focuses on a cylindrical microchannel configuration, mimicking the morphology of a human secretory duct, within which the epithelium is located. Various microchannel diameters were assessed for successful promotion of cell cultures, and it was observed that diameters of 150-400 µm were the most successful. Furthermore, cellular adhesion endured throughout this experimentation, despite the introduction of physical stress through variations in microfluidic currents.
The objective of these constructions is to facilitate the collection of prostatic fluid, along with gauging cellular reactions to microenvironmental changes. Additionally, prostate-on-a-chip enables the recreation of metastasis scenarios, which allows the assessment of drug candidates and other therapeutic approaches. Scalability of this method is also attractive to researchers, as the reusable mold approach ensures a low-cost of production. | 2 | Tissue Engineering |
Monosaccharides are the major fuel source for metabolism, being used both as an energy source (glucose being the most important in nature as it is the product of photosynthesis in plants) and in biosynthesis. When monosaccharides are not immediately needed, they are often converted to more space-efficient (i.e., less water-soluble) forms, often polysaccharides. In many animals, including humans, this storage form is glycogen, especially in liver and muscle cells. In plants, starch is used for the same purpose. The most abundant carbohydrate, cellulose, is a structural component of the cell wall of plants and many forms of algae. Ribose is a component of RNA. Deoxyribose is a component of DNA. Lyxose is a component of lyxoflavin found in the human heart. Ribulose and xylulose occur in the pentose phosphate pathway. Galactose, a component of milk sugar lactose, is found in galactolipids in plant cell membranes and in glycoproteins in many tissues. Mannose occurs in human metabolism, especially in the glycosylation of certain proteins. Fructose, or fruit sugar, is found in many plants and humans, it is metabolized in the liver, absorbed directly into the intestines during digestion, and found in semen. Trehalose, a major sugar of insects, is rapidly hydrolyzed into two glucose molecules to support continuous flight. | 6 | Carbohydrates |
The absence of fructokinase results in the inability to phosphorylate fructose to fructose-1-phosphate within the cell. As a result, fructose is neither trapped within the cell nor directed toward its metabolism. Free fructose concentrations in the liver increase and fructose is free to leave the cell and enter plasma. This results in an increase in plasma concentration of fructose, eventually exceeding the kidneys' threshold for fructose reabsorption resulting in the appearance of fructose in the urine. Essential fructosuria is a benign asymptomatic condition. | 6 | Carbohydrates |
The impact of ultraviolet radiation on human health has implications for the risks and benefits of sun exposure and is also implicated in issues such as fluorescent lamps and health. Getting too much sun exposure can be harmful, but in moderation, sun exposure is beneficial. | 8 | Ultraviolet Radiation |
Cold hardening has also been observed in insects such as the fruit fly and diamondback moth. The insects use rapid cold hardening to protect against cold shock during overwintering periods. Overwintering insects stay awake and active through the winter while non-overwintering insects migrate or die. Rapid cold hardening can be experienced during short periods of undesirable temperatures, such as cold shock in environment temperature, as well as the common cold months. The buildup of cryoprotective compounds is the reason that insects can experience cold hardening. Glycerol is a cryoprotective substance found within these insects capable of overwintering. Through testing, glycerol requires interactions with other cell components within the insect in order to decrease the body's permeability to the cold. When an insect is exposed to these cold temperatures, glycerol rapidly accumulates. Glycerol is known as a non-ionic kosmotrope forming powerful hydrogen bonds with water molecules. The hydrogen bonds in the glycerol compound compete with the weaker bonds between the water molecules causing an interruption in the makeup of ice formation. This chemistry found within the glycerol compound and reaction between water has been used as an antifreeze in the past, and can be seen here when concerning cold hardening. Proteins also play a large role in the cryoprotective compounds that increase ability to survive the cold hardening process and environmental change. Glycogen phosphorylase (GlyP) has been a key protein found during testing to increase in comparison to a controlled group not experiencing the cold hardening. Once warmer temperatures are observed the process of acclimation begins, and the increased glycerol along with other cryoprotective compounds and proteins are also reversed. There is a rapid cold hardening capacity found within certain insects that suggests not all insects can survive a long period of overwintering. Non-diapausing insects can sustain brief temperature shocks but often have a limit to what they can handle before the body can no longer produce enough cryoprotective components.
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Inclusive to the cold hardening process being beneficial for insects survival during cold temperatures, it also helps improve the organisms performance. Rapid cold hardening (RCH) is one of the fastest cold temperature responses recorded. This process allows an insect to instantly adapt to the severe weather change without compromising function. The Drosophila melanogaster' (common fruit fly) is a frequently experimented insect involving cold hardening. A proven example of RCH enhancing organisms performance comes from courting and mating within the fruit fly. It has been tested that the fruit fly mated more frequently once RCH has commenced in relation to a controlled insect group not experiencing RCH. Most insects experiencing extended cold periods are observed to modify the membrane lipids within the body. Desaturation of fatty acids are the most commonly seen modification to the membrane. When the fruit fly was observed under the stressful climate the survival rate increased in comparison to the fly prior to cold hardening.
In addition to testing on the common fruit fly, Plutella xylostella (diamondback moth) also has been widely studied for its significance in cold hardening. While this insect also shows an increase in glycerol and similar cryoprotective compounds, it also shows an increase in polyols. These compounds are specifically linked to cryoprotective compounds designed to withstand cold hardening. The polyol compound is freeze-susceptible and freeze tolerant. Polyols simply act as a barrier within the insect body by preventing intracellular freezing by restricting the extracellular freezing likely to happen in overwintering periods. During the larval stage of the diamondback moth, the significance of glycerol was tested again for validity. The lab injected the larvae with added glycerol and in turn proved that glycerol is a major factor in survival rate when cold hardening. The cold tolerance is directly proportional to the buildup of glycerol during cold hardening.
Cold hardening of insects improves the survival rate of the species and improves function. Once environmental temperature begins to warm up above freezing, the cold hardening process is reversed and the glycerol and cryoprotective compounds decrease within the body. This also reverts the function of the insect to pre-cold hardening activity. | 1 | Cryobiology |
Captive populations are subject to problems such as inbreeding depression, loss of genetic diversity and adaptations to captivity. It is important to manage captive populations in a way that minimizes these issues so that the individuals to be introduced will resemble the original founders as closely as possible, which will increase the chances of successful reintroductions. During the initial growth phase, the population size is rapidly expanded until a target population size is reached. The target population size is the number of individuals that are required to maintain appropriate levels of genetic diversity, which is generally considered to be 90% of the current genetic diversity after 100 years. The number of individuals required to meet this goal varies based on potential growth rate, effective size, current genetic diversity, and generation time. Once the target population size is reached, the focus shifts to maintaining the population and avoiding genetic issues within the captive population. | 1 | Cryobiology |
Spin ices are geometrically frustrated magnetic systems. While frustration is usually associated with triangular or tetrahedral arrangements of magnetic moments coupled via antiferromagnetic exchange interactions, as in Andersons Ising model, spin ices are frustrated ferromagnets. It is the very strong local magnetic anisotropy from the crystal field forcing the magnetic moments to point either in or out of a tetrahedron that renders ferromagnetic interactions frustrated in spin ices. Most importantly, it is the long-range magnetostatic dipole–dipole interaction, and not' the nearest-neighbor exchange, that causes the frustration and the consequential two-in, two-out rule that leads to the spin ice phenomenology.
For a tetrahedron in a two-in, two-out state, the magnetization field is divergent-free; there is as much "magnetization intensity" entering a tetrahedron as there is leaving (see figure 3). In such a divergent-free situation, there exists no source or sink for the field. According to Gauss theorem (also known as Ostrogradskys theorem), a nonzero divergence of a field is caused, and can be characterized, by a real number called "charge". In the context of spin ice, such charges characterizing the violation of the two-in, two-out magnetic moment orientation rule are the aforementioned monopoles.
In Autumn 2009, researchers reported experimental observation of low-energy quasiparticles resembling the predicted monopoles in spin ice. A single crystal of the dysprosium titanate spin ice candidate was examined in the temperature range of 0.6–2.0K. Using neutron scattering, the magnetic moments were shown to align in the spin ice material into interwoven tube-like bundles resembling Dirac strings. At the defect formed by the end of each tube, the magnetic field looks like that of a monopole. Using an applied magnetic field, the researchers were able to control the density and orientation of these strings. A description of the heat capacity of the material in terms of an effective gas of these quasiparticles was also presented.
The effective charge of a magnetic monopole, Q (see figure 3) in both the dysprosium and holmium titanate spin ice compounds is approximately (Bohr magnetons per angstrom). The elementary magnetic constituents of spin ice are magnetic dipoles, so the emergence of monopoles is an example of the phenomenon of fractionalization.
The microscopic origin of the atomic magnetic moments in magnetic materials is quantum mechanical; the Planck constant enters explicitly in the equation defining the magnetic moment of an electron, along with its charge and its mass. Yet, the magnetic moments in the dysprosium titanate and the holmium titanate spin ice materials are effectively described by classical statistical mechanics, and not quantum statistical mechanics, over the experimentally relevant and reasonably accessible temperature range (between 0.05K and 2K) where the spin ice phenomena manifest themselves. Although the weakness of quantum effects in these two compounds is rather unusual, it is believed to be understood. There is current interest in the search of quantum spin ices, materials in which the laws of quantum mechanics now become needed to describe the behavior of the magnetic moments. Magnetic ions other than dysprosium (Dy) and holmium (Ho) are required to generate a quantum spin ice, with praseodymium (Pr), terbium (Tb) and ytterbium (Yb) being possible candidates. One reason for the interest in quantum spin ice is the belief that these systems may harbor a quantum spin liquid, a state of matter where magnetic moments continue to wiggle (fluctuate) down to absolute zero temperature. The theory describing the low-temperature and low-energy properties of quantum spin ice is akin to that of vacuum quantum electrodynamics, or QED. This constitutes an example of the idea of emergence. | 7 | Magnetic Ordering |
Galactomannans are used in foods as stabilisers. Guar and locust bean gum (LBG) are commonly used in ice cream to improve texture and reduce ice cream meltdown. LBG is also used extensively in cream cheese, fruit preparations and salad dressings. Tara gum is seeing growing acceptability as a food ingredient but is still used to a much lesser extent than guar or LBG. Guar has the highest usage in foods, largely due to its low and stable price. | 6 | Carbohydrates |
A contract was signed between TERMIS and the Mary Ann Liebert publisher which designated the journal Tissue Engineering, Parts A, B, and C as the official journal of TERMIS with free on-line access for the membership. | 2 | Tissue Engineering |
Molecular distillation is a type of short-path vacuum distillation, characterized by an extremely low vacuum pressure, 0.01 torr or below, which is performed using a molecular still. It is a process of separation, purification and concentration of natural products, complex and thermally sensitive molecules for example vitamins and polyunsaturated fatty acids. This process is characterized by short term exposure of the distillate liquid to high temperatures in high vacuum (around mmHg) in the distillation column and a small distance between the evaporator and the condenser around 2 cm. In molecular distillation, fluids are in the free molecular flow regime, i.e. the mean free path of molecules is comparable to the size of the equipment. The gaseous phase no longer exerts significant pressure on the substance to be evaporated, and consequently, rate of evaporation no longer depends on pressure. The motion of molecules is in the line of sight, because they do not form a continuous gas anymore. Thus, a short path between the hot surface and the cold surface is necessary, typically by suspending a hot plate covered with a film of feed next to a cold plate with a line of sight in between.
This process has the advantages of avoiding the problem of toxicity that occurs in techniques that use solvents as the separating agent, and also of minimizing losses due to thermal decomposition. and can be used in a continuous feed process to harvest distillate without having to break vacuum.
Molecular distillation is used industrially for purification of oils. It is also used to enrich borage oil in γ-linolenic acid (GLA) and also to recover tocopherols from deodorizer distillate of soybean oil (DDSO). Molecular stills were historically used by Wallace Carothers in the synthesis of larger polymers, as a reaction product, water, interfered with polymerization by undoing the reaction via hydrolysis, but the water could be removed by the molecular still. | 5 | Separation Processes |
Salting in refers to the effect where increasing the ionic strength of a solution increases the solubility of a solute, such as a protein. This effect tends to be observed at lower ionic strengths.
Protein solubility is a complex function of physicochemical nature of the protein, pH, temperature, and the concentration of the salt used. It also depends on whether the salt is kosmotropic, whereby the salt will stabilize water. The solubility of proteins usually increases slightly in the presence of salt, referred to as "salting in". However, at high concentrations of salt, the solubility of the proteins drop sharply and proteins can precipitate out, referred to as "salting out". | 5 | Separation Processes |
In the 1950s, Norwegian scientist Scholander set out to explain how Arctic fish can survive in water colder than the freezing point of their blood. His experiments led him to believe there was “antifreeze” in the blood of Arctic fish. Then in the late 1960s, animal biologist Arthur DeVries was able to isolate the antifreeze protein through his investigation of Antarctic fish. These proteins were later called antifreeze glycoproteins (AFGPs) or antifreeze glycopeptides to distinguish them from newly discovered nonglycoprotein biological antifreeze agents (AFPs). DeVries worked with Robert Feeney (1970) to characterize the chemical and physical properties of antifreeze proteins. In 1992, Griffith et al. documented their discovery of AFP in winter rye leaves. Around the same time, Urrutia, Duman and Knight (1992) documented thermal hysteresis protein in angiosperms. The next year, Duman and Olsen noted AFPs had also been discovered in over 23 species of angiosperms, including ones eaten by humans. They reported their presence in fungi and bacteria as well. | 1 | Cryobiology |
In naphtha cracking process, C4R4 refers to C4 residual obtained after separation of 1,3-butadiene, isobutylene, 1-butene, and cis- or trans-2-butene from C4 raffinate stream which mainly consists of n-butane. Normally C4R4 is a side product in tert-butyl alcohol plant if C4R3 is used for feed. | 5 | Separation Processes |
The Institute for Problems of Cryobiology and Cryomedicine in Kharkiv is one of the institutes of the National Academy of Science of Ukraine, and is the largest institute devoted to cryobiology research in the world. | 1 | Cryobiology |
Israel has the highest rate of IVF in the world, with 1,657 procedures performed per million people per year. Couples without children can receive funding for IVF for up to two children. The same funding is available for people without children who will raise up to two children in a single parent home. IVF is available for people aged 18 to 45. The Israeli Health Ministry says it spends roughly $3450 per procedure. | 1 | Cryobiology |
Between 1995 and 2004 in the United States, an average of 1560 cold-related emergency department visits occurred per year and in the years 1999 to 2004, an average of 647 people died per year due to hypothermia. Of deaths reported between 1999 and 2002 in the US, 49% of those affected were 65 years or older and two-thirds were male. Most deaths were not work related (63%) and 23% of affected people were at home. Hypothermia was most common during the autumn and winter months of October through March. In the United Kingdom, an estimated 300 deaths per year are due to hypothermia, whereas the annual incidence of hypothermia-related deaths in Canada is 8000. | 1 | Cryobiology |
AFPs are thought to inhibit ice growth by an adsorption–inhibition mechanism. They adsorb to nonbasal planes of ice, inhibiting thermodynamically-favored ice growth. The presence of a flat, rigid surface in some AFPs seems to facilitate its interaction with ice via Van der Waals force surface complementarity. | 1 | Cryobiology |
Conventional fission power systems rely on a chain reaction of nuclear fission events that release a few neutrons that cause further fission events. By careful arrangement and the use of various absorber materials the system can be set in a balance of released and absorbed neutrons, known as criticality.
Natural uranium is a mix of several isotopes, mainly a trace amount of U and over 99% U. When they undergo fission, both of these isotopes release fast neutrons with an energy distribution peaking around 1 to 2 MeV. This energy is too low to cause fission in U, which means it cannot sustain a chain reaction. U will undergo fission when struck by neutrons of this energy, so it is possible for U to sustain a chain reaction. There are too few U atoms in natural uranium to sustain a chain reaction, the atoms are spread out too far and the chance a neutron will hit one is too small. Chain reactions are accomplished by concentrating, or enriching, the fuel, increasing the amount of U to produce enriched uranium, while the leftover, now mostly U, is a waste product known as depleted uranium. U will sustain a chain reaction if enriched to about 20% of the fuel mass.
U will undergo fission more easily if the neutrons are of lower energy, the so-called thermal neutrons. Neutrons can be slowed to thermal energies through collisions with a neutron moderator material, the easiest to use are the hydrogen atoms found in water. By placing the fission fuel in water, the probability that the neutrons will cause fission in another U is greatly increased, which means the level of enrichment needed to reach criticality is greatly reduced. This leads to the concept of reactor-grade enriched uranium, with the amount of U increased from just less than 1% in natural ore to between 3 and 5%, depending on the reactor design. This is in contrast to weapons-grade enrichment, which increases to the U to at least 20%, and more commonly, over 90%.
In order to maintain criticality, the fuel has to retain that extra concentration of U. A typical fission reactor burns off enough of the U to cause the reaction to stop over a period on the order of a few months. A combination of burnup of the U along with the creation of neutron absorbers, or poisons, as part of the fission process eventually results in the fuel mass not being able to maintain criticality. This burned up fuel has to be removed and replaced with fresh fuel. The result is nuclear waste that is highly radioactive and filled with long-lived radionuclides that present a safety concern.
The waste contains most of the U it started with, only 1% or so of the energy in the fuel is extracted by the time it reaches the point where it is no longer fissile. One solution to this problem is to reprocess the fuel, which uses chemical processes to separate the U (and other non-poison elements) from the waste, and then mixes the extracted U5 in fresh fuel loads. This reduces the amount of new fuel that needs to be mined and also concentrates the unwanted portions of the waste into a smaller load. Reprocessing is expensive, however, and it has generally been more economical to simply buy fresh fuel from the mine.
Like U, Pu can maintain a chain reaction, so it is a useful reactor fuel. However, Pu is not found in commercially useful amounts in nature. Another possibility is to breed Pu from the U through neutron capture, or various other means. This process only occurs with higher-energy neutrons than would be found in a moderated reactor, so a conventional reactor only produces small amounts of Pu when the neutron is captured within the fuel mass before it is moderated.
More typically, special reactors are used that are designed specifically for the breeding of Pu. The simplest way to achieve this is to further enrich the original U fuel well beyond what is needed for use in a moderated reactor, to the point where the U maintains criticality even with the fast neutrons. The extra fast neutrons escaping the fuel load can then be used to breed fuel in a U assembly surrounding the reactor core, most commonly taken from the stocks of depleted uranium. Pu can also be used for the core, which means once the system is up and running, it can be refuelled using the Pu it creates, with enough left over to feed into other reactors as well.
Extracting the Pu from the U feedstock can be achieved with chemical processing, in the same fashion as normal reprocessing. The difference is that the mass will contain far fewer other elements, particularly some of the highly radioactive fission products found in normal nuclear waste. Unfortunately it is a tendency that breeder reactors in the "free world" (like the SNR-300, the Integral fast reactor) that have been built were demolished before operation, as a "symbol" (as Bill Clinton has stated). The Prototype Fast Breeder Reactor passed tests in 2017 and apparently is about to face the same fate, leaving some military reactors and the Russian BN-800 reactor operating, mostly consuming spent nuclear fuel. | 3 | Nuclear Fusion |
Elevated O-GlcNAc has been associated with diabetes.
Pancreatic β cells synthesize and secrete insulin to regulate blood glucose levels. One study found that inhibition of OGA with streptozotocin followed by glucosamine treatment resulted in O-GlcNAc accumulation and apoptosis in β cells; a subsequent study showed that a galactose-based analogue of streptozotocin was unable to inhibit OGA but still resulted in apoptosis, suggesting that the apoptotic effects of streptozotocin are not directly due to OGA inhibition.
O-GlcNAc has been suggested to attenuate insulin signaling. In 3T3-L1 adipocytes, OGA inhibition with PUGNAc inhibited insulin-mediated glucose uptake. PUGNAc treatment also inhibited insulin-stimulated Akt T308 phosphorylation and downstream GSK3β S9 phosphorylation. In a later study, insulin stimulation of COS-7 cells caused OGT to localize to the plasma membrane. Inhibition of PI3K with wortmannin reversed this effect, suggesting dependence on phosphatidylinositol(3,4,5)-triphosphate. Increasing O-GlcNAc levels by subjecting cells to high glucose conditions or PUGNAc treatment inhibited insulin-stimulated phosphorylation of Akt T308 and Akt activity. IRS1 phosphorylation at S307 and S632/S635, which is associated with attenuated insulin signaling, was enhanced. Subsequent experiments in mice with adenoviral delivery of OGT showed that OGT overexpression negatively regulated insulin signaling in vivo. Many components of the insulin signaling pathway, including β-catenin, IR-β, IRS1, Akt, PDK1, and the p110α subunit of PI3K were found to be directly modified by O-GlcNAc. Insulin signaling has also been reported to lead to OGT tyrosine phosphorylation and OGT activation, resulting in increased O-GlcNAc levels.
As PUGNAc also inhibits lysosomal β-hexosaminidases, the OGA-selective inhibitor NButGT was developed to further probe the relationship between O-GlcNAc and insulin signaling in 3T3-L1 adipocytes. This study also found that PUGNAc resulted in impaired insulin signaling, but NButGT did not, as measured by changes in phosphorylation of Akt T308, suggesting that the effects observed with PUGNAc may be due to off-target effects besides OGA inhibition. | 6 | Carbohydrates |
Psychrophiles include bacteria, lichens, snow algae, phytoplankton, fungi, and insects.
Among the bacteria that can tolerate extreme cold are Arthrobacter sp., Psychrobacter sp. and members of the genera Halomonas, Pseudomonas, Hyphomonas, and Sphingomonas. Another example is Chryseobacterium greenlandensis, a psychrophile that was found in 120,000-year-old ice.
Umbilicaria antarctica and Xanthoria elegans are lichens that have been recorded photosynthesizing at temperatures ranging down to −24 °C, and they can grow down to around −10 °C. Some multicellular eukaryotes can also be metabolically active at sub-zero temperatures, such as some conifers; those in the Chironomidae family are still active at −16 °C.
Microalgae that live in snow and ice include green, brown, and red algae. Snow algae species such as Chloromonas sp., Chlamydomonas sp., and Chlorella sp. are found in polar environments.
Some phytoplankton can tolerate extremely cold temperatures and high salinities that occur in brine channels when sea ice forms in polar oceans. Some examples are diatoms like Fragilariopsis cylindrus, Nitzchia lecointeii, Entomoneis kjellmanii, Nitzchia stellata, Thalassiosira australis, Berkelaya adeliense, and Navicula glaciei.
Penicillium is a genus of fungi found in a wide range of environments including extreme cold.
Among the psychrophile insects, the Grylloblattidae or ice crawlers, found on mountaintops, have optimal temperatures between 1–4 °C. The wingless midge (Chironomidae) Belgica antarctica can tolerate salt, being frozen and strong ultraviolet, and has the smallest known genome of any insect. The small genome, of 99 million base pairs, is thought to be adaptive to extreme environments. | 1 | Cryobiology |
RO-purified rainwater collected from storm drains is used for landscape irrigation and industrial cooling in Los Angeles and other cities.
In industry, RO removes minerals from boiler water at power plants. The water is distilled multiple times to ensure that it does not leave deposits on the machinery or cause corrosion.
RO is used to clean effluent and brackish groundwater. The effluent in larger volumes (more than 500 m/day) is treated in a water treatment plant first, and then the effluent runs through RO. This hybrid process reduces treatment cost significantly and lengthens membrane life.
RO can be used for the production of deionized water.
In 2002, Singapore announced that a process named NEWater would be a significant part of its water plans. RO would be used to treat wastewater before discharging the effluent into reservoirs. | 5 | Separation Processes |
The main sources of CSDB data are:
* Scientific publications indexed in the dedicated citation databases, including [https://www.ncbi.nlm.nih.gov/pubmed/ NCBI Pubmed] and [http://webofknowledge.com/ Thomson Reuters Web Of Science] (approx. 18000 records).
* CCSD (Carbbank ) database (approx. 3000 records).
The data are selected and added to CSDB manually by browsing original scientific publications. The data originating from other databases are subject to error-correction and approval procedures.
As of 2017, the coverage on bacteria and archaea is ca. 80% of carbohydrate structures published in scientific literature The time lag between the publication of relative data and their deposition into CSDB is about 18 months. Plants are covered up to 1997, and fungi up to 2012.
CSDB does not cover data from the animalia domain, except unicellular metazoa. There is a number of dedicated databases on animal carbohydrates, e.g. [http://www.unicarbkb.org/ UniCarbKB] or [http://glycosciences.de GLYCOSCIENCES.de] .
CSDB is reported as one of the biggest projects in glycoinformatics. It is employed in structural studies of natural carbohydrates and in glyco-profiling.
The content of CSDB has been used as a data source in other glycoinformatics projects. | 6 | Carbohydrates |
Pistol shrimp (also called snapping shrimp) produce a type of cavitation luminescence from a collapsing bubble caused by quickly snapping its claw. The animal snaps a specialized claw shut to create a cavitation bubble that generates acoustic pressures of up to 80 kPa at a distance of 4 cm from the claw. As it extends out from the claw, the bubble reaches speeds of 60 miles per hour (97 km/h) and releases a sound reaching 218 decibels. The pressure is strong enough to kill small fish. The light produced is of lower intensity than the light produced by typical sonoluminescence and is not visible to the naked eye. The light and heat produced by the bubble may have no direct significance, as it is the shockwave produced by the rapidly collapsing bubble which these shrimp use to stun or kill prey. However, it is the first known instance of an animal producing light by this effect and was whimsically dubbed "shrimpoluminescence" upon its discovery in 2001. It has subsequently been discovered that another group of crustaceans, the mantis shrimp, contains species whose club-like forelimbs can strike so quickly and with such force as to induce sonoluminescent cavitation bubbles upon impact.
A mechanical device with 3D printed snapper claw at five times the actual size was also reported to emit light in a similar fashion, this bioinspired design was based on the snapping shrimp snapper claw molt shed from an Alpheus formosus, the striped snapping shrimp. | 0 | Luminescence |
Ultraviolet helps detect organic material deposits that remain on surfaces where periodic cleaning and sanitizing may have failed. It is used in the hotel industry, manufacturing, and other industries where levels of cleanliness or contamination are inspected.
Perennial news features for many television news organizations involve an investigative reporter using a similar device to reveal unsanitary conditions in hotels, public toilets, hand rails, and such. | 8 | Ultraviolet Radiation |
Hydridohelium(1+), specifically , was first detected indirectly in 1925 by T. R. Hogness and E. G. Lunn. They were injecting protons of known energy into a rarefied mixture of hydrogen and helium, in order to study the formation of hydrogen ions like , and . They observed that appeared at the same beam energy (16 eV) as , and its concentration increased with pressure much more than that of the other two ions. From these data, they concluded that the ions were transferring a proton to molecules that they collided with, including helium.
In 1933, K. Bainbridge used mass spectrometry to compare the masses of the ions (helium hydride ion) and (twice-deuterated trihydrogen ion) in order to obtain an accurate measurement of the atomic mass of deuterium relative to that of helium. Both ions have 3 protons, 2 neutrons, and 2 electrons. He also compared (helium deuteride ion) with (trideuterium ion), both with 3 protons and 3 neutrons. | 4 | Acids + Bases |
Researchers in the field have developed approaches to produce living organs that are constructed with the appropriate biological and mechanical properties. 3D bioprinting is based on three main approaches: biomimicry, autonomous self-assembly and mini-tissue building blocks. | 2 | Tissue Engineering |
Hypothermia has played a major role in the success or failure of many military campaigns, from Hannibals loss of nearly half his men in the Second Punic War (218 B.C.) to the near destruction of Napoleons armies in Russia in 1812. Men wandered around confused by hypothermia, some lost consciousness and died, others shivered, later developed torpor, and tended to sleep. Others too weak to walk fell on their knees; some stayed that way for some time resisting death. The pulse of some was weak and hard to detect; others groaned; yet others had eyes open and wild with quiet delirium. Deaths from hypothermia in Russian regions continued through the first and second world wars, especially in the Battle of Stalingrad.
Civilian examples of deaths caused by hypothermia occurred during the sinkings of the RMS Titanic and RMS Lusitania, and more recently of the MS Estonia.
Antarctic explorers developed hypothermia; Ernest Shackleton and his team measured body temperatures "below 94.2°, which spells death at home", though this probably referred to oral temperatures rather than core temperature and corresponded to mild hypothermia. One of Scott's team, Atkinson, became confused through hypothermia.
Nazi human experimentation during World War II amounting to medical torture included hypothermia experiments, which killed many victims. There were 360 to 400 experiments and 280 to 300 subjects, indicating some had more than one experiment performed on them. Various methods of rewarming were attempted: "One assistant later testified that some victims were thrown into boiling water for rewarming". | 1 | Cryobiology |
The belt-type machine is generally more applicable to smaller and to adhesive feed. In addition, the feed presentation is more stable which makes it more applicable for more difficult and heterogenous applications. | 5 | Separation Processes |
Oleum is produced in the contact process, where sulfur is oxidized to sulfur trioxide which is subsequently dissolved in concentrated sulfuric acid. Sulfuric acid itself is regenerated by dilution of part of the oleum.
The lead chamber process for sulfuric acid production was abandoned, partly because it could not produce sulfur trioxide or concentrated sulfuric acid directly due to corrosion of the lead, and absorption of NO gas. Until this process was made obsolete by the contact process, oleum had to be obtained through indirect methods. Historically, the biggest production of oleum came from the distillation of iron sulfates at Nordhausen, from which the historical name Nordhausen sulfuric acid is derived. | 4 | Acids + Bases |
In the United States, overall availability of IVF in 2005 was 2.5 IVF physicians per 100,000 population, and utilisation was 236 IVF cycles per 100,000. 126 procedures are performed per million people per year. Utilisation highly increases with availability and IVF insurance coverage, and to a significant extent also with percentage of single persons and median income. In the US, an average cycle, from egg retrieval to embryo implantation, costs $12,400, and insurance companies that do cover treatment, even partially, usually cap the number of cycles they pay for. As of 2015, more than 1 million babies had been born utilising IVF technologies.
In the US, nineteen states have laws requiring insurance coverage for infertility treatment, and thirteen of those specifically include IVF. These states that mandate IVF coverage are: Arkansas, California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Louisiana, Maryland, Massachusetts, Montana, New Hampshire, New Jersey, New York, Ohio, Rhode Island, Texas, Utah, and West Virginia. These laws differ by state but many require an egg be fertilised with sperm from a spouse and that in order to be covered you must show you cannot become pregnant through penile-vaginal sex. These requirements are not possible for a same-sex couple to meet. No state Medicaid program, however, covers for IVF according to a 2020 report.
Many fertility clinics in the United States limit the upper age at which people are eligible for IVF to 50 or 55 years. These cut-offs make it difficult for people older than fifty-five to utilise the procedure. | 1 | Cryobiology |
Liquid inks can be any material that is liquid at deposition conditions. The liquid deposition properties are determined by the interactions between the liquid and the tip, the liquid and the surface, and the viscosity of the liquid itself. These interactions limit the minimum feature size of the liquid ink to about 1 micrometre, depending on the contact angle of the liquid. Higher viscosities offer greater control over feature size and are desirable. Unlike molecular inks, it is possible to perform multiplexed depositions using a carrier liquid. For example, using a viscous buffer, it is possible to directly deposit multiple proteins simultaneously.
*1–10 micrometre feature resolution
*Multiplexed depositions
*Less restrictive ink/surface requirements
*Direct deposition of high viscosity materials | 2 | Tissue Engineering |
In physics, the Landau–Lifshitz–Gilbert equation (usually abbreviated as LLG equation), named for Lev Landau, Evgeny Lifshitz, and T. L. Gilbert, is a name used for a differential equation describing the dynamics (typically the precessional motion) of magnetization in a solid. It is a modified version by Gilbert of the original equation of Landau and Lifshitz. The LLG equation is similar to the Bloch equation, but they differ in the form of the damping term. The LLG equation describes a more general scenario of magnetization dynamics beyond the simple Larmor precession. In particular, the effective field driving the precessional motion of is not restricted to real magnetic fields; it incorporates a wide range of mechanisms including magnetic anisotropy, exchange interaction, and so on.
The various forms of the LLG equation are commonly used in micromagnetics to model the effects of a magnetic field and other magnetic interactions on ferromagnetic materials. It provides a practical way to model the time-domain behavior of magnetic elements. Recent developments generalizes the LLG equation to include the influence of spin-polarized currents in the form of spin-transfer torque. | 7 | Magnetic Ordering |
Magnetic phase transitions can be either first order or second order. The nature of the transition can be inferred from the Arrott plot based on the slope of the magnetic isotherms. If the lines are all positive slope, the phase transition is second order, whereas if there are negative slope lines, the phase transition is first order. This condition is known as the Banerjee criterion.
The Banerjee criterion is not always accurate for evaluating inhomogeneous ferromagnets, since the slopes can all be positive even when the transition is first-order. | 7 | Magnetic Ordering |
A hysteresis effect may be observed in voicing onset versus offset. The threshold value of the subglottal pressure required to start the vocal fold vibration is lower than the threshold value at which the vibration stops, when other parameters are kept constant. In utterances of vowel-voiceless consonant-vowel sequences during speech, the intraoral pressure is lower at the voice onset of the second vowel compared to the voice offset of the first vowel, the oral airflow is lower, the transglottal pressure is larger and the glottal width is smaller. | 7 | Magnetic Ordering |
The design includes a removable vacuum vessel (the solid component that separates the plasma and the surrounding vacuum from the liquid blanket). It does not require dismantling the entire device. That makes it well-suited for evaluating design changes. | 3 | Nuclear Fusion |
The primary structure of RiAFP (the sequence may be found [https://www.ncbi.nlm.nih.gov/protein/313766639 here]) determined by Mass Spectroscopy, Edman degradation and by constructing a partial cDNA sequence and PCR have shown that a TxTxTxT internal repeat exists. Sequence logos constructed from the RiAFP internal repeats, have been particularly helpful in the determination of the consensus sequence of these repeats. The TxTxTxT domains are irregularly spaced within the protein and have been shown to be conserved from the TxT binding motif of other AFPs. The hydroxyl moiety of the T residues fits well, when spaced as they are in the internal repeats, with the hydroxyl moieties of externally facing water molecules in the forming ice lattice. This mimics the formation of the growth cone at a nucleation site in the absence of AFPs. Thus, the binding of RiAFP inhibits the growth of the crystal in the basal and prism planes of the ice. | 1 | Cryobiology |
During the degradation of α-hydroxy-substituted carbonic acid amides, the carbon chain shortens about one carbon-atom, too.
The reaction is very slow at room temperature, therefore the reaction mixture is heated up to 60–65 °C. | 6 | Carbohydrates |
The epithelial–mesenchymal transition (EMT) is a process by which epithelial cells lose their cell polarity and cell–cell adhesion, and gain migratory and invasive properties to become mesenchymal stem cells; these are multipotent stromal cells that can differentiate into a variety of cell types. EMT is essential for numerous developmental processes including mesoderm formation and neural tube formation. EMT has also been shown to occur in wound healing, in organ fibrosis and in the initiation of metastasis in cancer progression. | 2 | Tissue Engineering |
Some cryoprotectants function by lowering the glass transition temperature of a solution or of a material. In this way, the cryoprotectant prevents actual freezing, and the solution maintains some flexibility in a glassy phase. Many cryoprotectants also function by forming hydrogen bonds with biological molecules as water molecules are displaced. Hydrogen bonding in aqueous solutions is important for proper protein and DNA function. Thus, as the cryoprotectant replaces the water molecules, the biological material retains its native physiological structure and function, although they are no longer immersed in an aqueous environment. This preservation strategy is most often utilized in anhydrobiosis. | 1 | Cryobiology |
Abbreviations:
*Ex (nm): Excitation wavelength in nanometers
*Em (nm): Emission wavelength in nanometers
*MW: Molecular weight
*QY: Quantum yield | 0 | Luminescence |
Trehalose is a nonreducing sugar formed from two glucose units joined by a 1–1 alpha bond, giving it the name The bonding makes trehalose very resistant to acid hydrolysis, and therefore is stable in solution at high temperatures, even under acidic conditions. The bonding keeps nonreducing sugars in closed-ring form, such that the aldehyde or ketone end groups do not bind to the lysine or arginine residues of proteins (a process called glycation). Trehalose is less soluble than sucrose, except at high temperatures (>80 °C). Trehalose forms a rhomboid crystal as the dihydrate, and has 90% of the calorific content of sucrose in that form. Anhydrous forms of trehalose readily regain moisture to form the dihydrate. Anhydrous forms of trehalose can show interesting physical properties when heat-treated.
Trehalose aqueous solutions show a concentration-dependent clustering tendency. Owing to their ability to form hydrogen bonds, they self-associate in water to form clusters of various sizes. All-atom molecular dynamics simulations showed that concentrations of 1.5–2.2 molar allow trehalose molecular clusters to percolate and form large and continuous aggregates.
Trehalose directly interacts with nucleic acids, facilitates melting of double stranded DNA and stabilizes single-stranded nucleic acids. | 6 | Carbohydrates |
Initial salting in at low concentrations is explained by the Debye–Huckel theory. Proteins are surrounded by the salt counterions (ions of opposite net charge) and this screening results in decreasing electrostatic free energy of the protein and increasing activity of the solvent, which in turn leads to increasing solubility. This theory predicts that the logarithm of solubility is proportional to the square root of the ionic strength.
The behavior of proteins in solutions at high salt concentrations is explained by John Gamble Kirkwood. The abundance of the salt ions decreases the solvating power of salt ions, resulting in the decrease in the solubility of the proteins and precipitation results.
At high salt concentrations, the solubility is given by the following empirical expression.
:log S = B − KI
where S is the solubility of the protein, B is a constant (function of protein, pH and temperature), K is the salting out constant (function of pH, mixing and salt), and I is the ionic strength of the salt. This expression is an approximation to that proposed by Long and McDevit. | 5 | Separation Processes |
*. [http://iopscience.iop.org/article/10.1088/0305-4608/5/5/017/meta;jsessionid=4B8D9A38523A828CD28C8CE67DD973E8.c5.iopscience.cld.iop.org ShieldSquare Captcha]
*. [https://archive.today/20130415143828/http://papercore.org/Sherrington1975 Papercore Summary http://papercore.org/Sherrington1975]
* [https://archive.today/20130415190815/http://papercore.org/Parisi1980 Papercore Summary http://papercore.org/Parisi1980]. | 7 | Magnetic Ordering |
Vaporization (from liquid to gas) is divided into two types: vaporization on the surface of the liquid is called evaporation, and vaporization at the boiling point with formation of bubbles in the interior of the liquid is called boiling. However there is no such distinction for the solid-to-gas transition, which is always called sublimation in both corresponding cases. | 5 | Separation Processes |
Solid acids are used in catalysis in many industrial chemical processes, from large-scale catalytic cracking in petroleum refining to the synthesis of various fine chemicals.
One large scale application is alkylation, e.g., the combination of benzene and ethylene to give ethylbenzene. Another application is the rearrangement of cyclohexanone oxime to caprolactam. Many alkylamines are prepared by amination of alcohols, catalyzed by solid acids.
Solid acids can be used as electrolytes in fuel cells. | 4 | Acids + Bases |
The dyes used in early experimental cells (circa 1995) were sensitive only in the high-frequency end of the solar spectrum, in the UV and blue. Newer versions were quickly introduced (circa 1999) that had much wider frequency response, notably "triscarboxy-ruthenium terpyridine" [Ru(4,4',4"-(COOH)-terpy)(NCS)], which is efficient right into the low-frequency range of red and IR light. The wide spectral response results in the dye having a deep brown-black color, and is referred to simply as "black dye". The dyes have an excellent chance of converting a photon into an electron, originally around 80% but improving to almost perfect conversion in more recent dyes, the overall efficiency is about 90%, with the "lost" 10% being largely accounted for by the optical losses in top electrode.
A solar cell must be capable of producing electricity for at least twenty years, without a significant decrease in efficiency (life span). The "black dye" system was subjected to 50 million cycles, the equivalent of ten years' exposure to the sun in Switzerland. No discernible performance decrease was observed. However the dye is subject to breakdown in high-light situations. Over the last decade an extensive research program has been carried out to address these concerns. The newer dyes included 1-ethyl-3 methylimidazolium tetrocyanoborate [EMIB(CN)] which is extremely light- and temperature-stable, copper-diselenium [Cu(In,GA)Se] which offers higher conversion efficiencies, and others with varying special-purpose properties.
DSSCs are still at the start of their development cycle. Efficiency gains are possible and have recently started more widespread study. These include the use of quantum dots for conversion of higher-energy (higher frequency) light into multiple electrons, using solid-state electrolytes for better temperature response, and changing the doping of the TiO to better match it with the electrolyte being used. | 8 | Ultraviolet Radiation |
UV is an investigative tool at the crime scene helpful in locating and identifying bodily fluids such as semen, blood, and saliva. For example, ejaculated fluids or saliva can be detected by high-power UV sources, irrespective of the structure or colour of the surface the fluid is deposited upon. UV–vis microspectroscopy is also used to analyze trace evidence, such as textile fibers and paint chips, as well as questioned documents.
Other applications include the authentication of various collectibles and art, and detecting counterfeit currency. Even materials not specially marked with UV sensitive dyes may have distinctive fluorescence under UV exposure or may fluoresce differently under short-wave versus long-wave ultraviolet. | 8 | Ultraviolet Radiation |
Epithelial–mesenchymal transition was first recognized as a feature of embryogenesis by Betty Hay in the 1980s. EMT, and its reverse process, MET (mesenchymal-epithelial transition) are critical for development of many tissues and organs in the developing embryo, and numerous embryonic events such as gastrulation, neural crest formation, heart valve formation, secondary palate development, and myogenesis. Epithelial and mesenchymal cells differ in phenotype as well as function, though both share inherent plasticity. Epithelial cells are closely connected to each other by tight junctions, gap junctions and adherens junctions, have an apico-basal polarity, polarization of the actin cytoskeleton and are bound by a basal lamina at their basal surface. Mesenchymal cells, on the other hand, lack this polarization, have a spindle-shaped morphology and interact with each other only through focal points. Epithelial cells express high levels of E-cadherin, whereas mesenchymal cells express those of N-cadherin, fibronectin and vimentin. Thus, EMT entails profound morphological and phenotypic changes to a cell.
Based on the biological context, EMT has been categorized into 3 types: developmental (Type I), fibrosis and wound healing (Type II), and cancer (Type III). | 2 | Tissue Engineering |
Metamagnetism is a sudden (often, dramatic) increase in the magnetization of a material with a small change in an externally applied magnetic field. The metamagnetic behavior may have quite different physical causes for different types of metamagnets. Some examples of physical mechanisms leading to metamagnetic behavior are:
# Itinerant metamagnetism - Exchange splitting of the Fermi surface in a paramagnetic system of itinerant electrons causes an energetically favorable transition to bulk magnetization near the transition to a ferromagnet or other magnetically ordered state.
# Antiferromagnetic transition - Field-induced spin flips in antiferromagnets cascade at a critical energy determined by the applied magnetic field.
Depending on the material and experimental conditions, metamagnetism may be associated with a first-order phase transition, a continuous phase transition at a critical point (classical or quantum), or crossovers beyond a critical point that do not involve a phase transition at all. These wildly different physical explanations sometimes lead to confusion as to what the term "metamagnetic" is referring in specific cases. | 7 | Magnetic Ordering |
FODMAPs or fermentable oligosaccharides, disaccharides, monosaccharides, and polyols are short-chain carbohydrates that are poorly absorbed in the small intestine and ferment in the colon. They include short-chain oligosaccharide polymers of fructose (fructans) and galactooligosaccharides (GOS, stachyose, raffinose), disaccharides (lactose), monosaccharides (fructose), and sugar alcohols (polyols), such as sorbitol, mannitol, xylitol, and maltitol. Most FODMAPs are naturally present in food and the human diet, but the polyols may be added artificially in commercially prepared foods and beverages.
FODMAPs may cause digestive discomfort in some people. The reasons are hypersensitivity to luminal distension and/or a proclivity to excess water retention and gas production and accumulation, but they do not cause intestinal inflammation. Naturally occurring FODMAPs may help avert digestive discomfort for some people because they produce beneficial alterations in the gut flora. They are not the cause of these disorders, but a low-FODMAP diet, restricting FODMAPs, might help to improve digestive symptoms in adults with irritable bowel syndrome (IBS) and other functional gastrointestinal disorders (FGID). Avoiding all FODMAPs long-term may have a detrimental impact on the gut microbiota and metabolome.
FODMAPs, especially fructans, are present in small amounts in gluten-containing grains and have been identified as a possible cause of symptoms in people with non-celiac gluten sensitivity. They are only minor sources of FODMAPs when eaten in the usual standard quantities in the daily diet. As of 2019, reviews conclude that although FODMAPs present in wheat and related grains may play a role in non-celiac gluten sensitivity, they only explain certain gastrointestinal symptoms, such as bloating, but not the extra-digestive symptoms that people with non-celiac gluten sensitivity may develop, such as neurological disorders, fibromyalgia, psychological disturbances, and dermatitis. Consuming a low FODMAP diet without a previous medical evaluation could cause health risks because it can ameliorate and mask digestive symptoms of celiac disease, delaying or avoiding its correct diagnosis and therapy. | 6 | Carbohydrates |
In magnetism, the Curie–Weiss law describes the magnetic susceptibility of a ferromagnet in the paramagnetic region above the Curie temperature:
where is a material-specific Curie constant, is the absolute temperature, and is the Curie temperature, both measured in kelvin. The law predicts a singularity in the susceptibility at . Below this temperature, the ferromagnet has a spontaneous magnetization. The name is given after Pierre Curie and Pierre Weiss. | 7 | Magnetic Ordering |
SBSL emits more light than MBSL due to fewer interactions between neighboring bubbles. Another advantage for SBSL is that a single bubble collapses without being affected by other surrounding bubbles, allowing more accurate studies on acoustic cavitation and sonoluminescence theories. Some exotic theories have been made, for example from Schwinger in 1992 who hinted the dynamical Casimir effect as a potential photon-emission process. Several theories say that the location of light emission is in the liquid instead of inside the bubble. Other SBSL theories explain that the emission of photons due to the high temperatures in the bubble are analogical to the hot spot theories of MBSL. Regarding the thermal emission a large variety of different processes are prevalent. Because temperatures are increasing from several hundred to many thousand kelvin during collapse, the processes can be molecular recombination, collision-induced emission, molecular emission, excimers, atomic recombination, radiative attachments of ions, neutral and ion Bremsstrahlung, or emission from confined electrons in voids. Which of these theories applies depends on accurate measurements and calculations of the temperature inside the bubble. | 0 | Luminescence |
Oleum is a harsh reagent, and is highly corrosive. One important use of oleum as a reagent is the secondary nitration of nitrobenzene. The first nitration can occur with nitric acid in sulfuric acid, but this deactivates the ring towards further electrophilic substitution. A stronger reagent, oleum, is needed to introduce the second nitro group onto the aromatic ring. | 4 | Acids + Bases |
Cold fusion researchers were for many years unable to get papers accepted at scientific meetings, prompting the creation of their own conferences. The International Conference on Cold Fusion (ICCF) was first held in 1990 and has met every 12 to 18 months since. Attendees at some of the early conferences were described as offering no criticism to papers and presentations for fear of giving ammunition to external critics, thus allowing the proliferation of crackpots and hampering the conduct of serious science. Critics and skeptics stopped attending these conferences, with the notable exception of Douglas Morrison, who died in 2001. With the founding in 2004 of the International Society for Condensed Matter Nuclear Science (ISCMNS), the conference was renamed the International Conference on Condensed Matter Nuclear Science—for reasons that are detailed in the subsequent research section above—but reverted to the old name in 2008. Cold fusion research is often referenced by proponents as "low-energy nuclear reactions", or LENR, but according to sociologist Bart Simon the "cold fusion" label continues to serve a social function in creating a collective identity for the field.
Since 2006, the American Physical Society (APS) has included cold fusion sessions at their semiannual meetings, clarifying that this does not imply a softening of skepticism. Since 2007, the American Chemical Society (ACS) meetings also include "invited symposium(s)" on cold fusion. An ACS program chair, Gopal Coimbatore, said that without a proper forum the matter would never be discussed and, "with the world facing an energy crisis, it is worth exploring all possibilities."
On 22–25 March 2009, the American Chemical Society meeting included a four-day symposium in conjunction with the 20th anniversary of the announcement of cold fusion. Researchers working at the U.S. Navys Space and Naval Warfare Systems Center (SPAWAR) reported detection of energetic neutrons using a heavy water electrolysis setup and a CR-39 detector, a result previously published in Naturwissenschaften'. The authors claim that these neutrons are indicative of nuclear reactions. Without quantitative analysis of the number, energy, and timing of the neutrons and exclusion of other potential sources, this interpretation is unlikely to find acceptance by the wider scientific community. | 3 | Nuclear Fusion |
Glycogen synthase catalyzes the conversion of the glucosyl (Glc) moiety of uridine diphosphate glucose (UDP-Glc) into glucose to be incorporated into glycogen via an α(1→4) glycosidic bond. However, since glycogen synthase requires an oligosaccharide primer as a glucose acceptor, it relies on glycogenin to initiate de novo glycogen synthesis.
In a recent study of transgenic mice, an overexpression of glycogen synthase and an overexpression of phosphatase both resulted in excess glycogen storage levels. This suggests that glycogen synthase plays an important biological role in regulating glycogen/glucose levels and is activated by dephosphorylation. | 6 | Carbohydrates |
Signs and symptoms vary depending on the degree of hypothermia, and may be divided by the three stages of severity. People with hypothermia may appear pale and feel cold to touch.
Infants with hypothermia may feel cold when touched, with bright red skin and an unusual lack of energy.
Behavioural changes such as impaired judgement, impaired sense of time and place, unusual aggression and numbness can be observed in individuals with hypothermia, they can also deny their condition and refuse any help. A hypothermic person can be euphoric and hallucinating.
Cold stress refers to a near-normal body temperature with low skin temperature, signs include shivering. Cold stress is caused by cold exposure and it can lead to hypothermia and frostbite if not treated. | 1 | Cryobiology |
In the second step, the liquid mixtures of cells, matrix, and nutrients known as bioinks are placed in a printer cartridge and deposited using the patients' medical scans. When a bioprinted pre-tissue is transferred to an incubator, this cell-based pre-tissue matures into a tissue.
3D bioprinting for fabricating biological constructs typically involves dispensing cells onto a biocompatible scaffold using a successive layer-by-layer approach to generate tissue-like three-dimensional structures. Artificial organs such as livers and kidneys made by 3D bioprinting have been shown to lack crucial elements that affect the body such as working blood vessels, tubules for collecting urine, and the growth of billions of cells required for these organs. Without these components the body has no way to get the essential nutrients and oxygen deep within their interiors. Given that every tissue in the body is naturally composed of different cell types, many technologies for printing these cells vary in their ability to ensure stability and viability of the cells during the manufacturing process. Some of the methods that are used for 3D bioprinting of cells are photolithography, magnetic 3D bioprinting, stereolithography, and direct cell extrusion. | 2 | Tissue Engineering |
Sperm banks make information available about the sperm donors whose donations they hold to enable customers to select the donor whose sperm they wish to use. This information is often available by way of an online catalog. Subscription fees to be able to view the sperm donor through California Cryobank, for example, start at $145. This cost could potentially be a barrier for many on limited income and may not have discretionary income to spend on sperm donor services.
A sperm bank will also usually have facilities to help customers to make their choice and they will be able to advise on the suitability of donors for individual donors and their partners.
Where the recipient has a partner, they may prefer to use sperm from a donor whose physical features are similar to those of their partner if they have one. In some cases, the choice of a donor with the correct blood group will be paramount, with particular considerations for the protection of recipients with negative blood groups. If a surrogate is to be used, such as where the customer is not intending to carry the child, considerations about their blood group etc. will also need to be taken into account. Similar considerations will apply where both partners in a lesbian couple intend to have a child using the same donor.
Information made available by a sperm bank will usually include the race, height, weight, blood group, health and eye color of the donor. Sometimes information about the donors age, family history and educational achievements will also be given. Some sperm banks make a personal profile of a donor available and occasionally more information may be purchased about a donor, either in the form of a DVD or in written form. Catalogs usually state whether samples supplied by a particular donor have already given rise to pregnancies, but this is not necessarily a guide to the fecundity of the sperm since a donor may not have been in the program long enough for any pregnancies to have been recorded. The donors educational qualification is also taken into account when choosing a donor.
If an individual intends to have more than one child, they may wish to have the additional child or children by the same donor. Sperm banks will usually advise whether sufficient stocks of sperm are available from a particular donor for subsequent pregnancies, and they normally have facilities available so that the woman may purchase and store additional vials from that donor on payment of an appropriate fee. These will be stored until required for subsequent pregnancies or they may be on-sold if they become surplus to the woman's requirements.
The catalogue will also state whether samples of sperm are available for ICI, IUI, or IVF use. | 1 | Cryobiology |
The tetrahydrate crystallizes as and two water molecules. The oxidation state of gold in and anion is +3. The salts of (tetrachloroauric(III) acid) are tetrachloroaurates(III), containing anions (tetrachloroaurate(III) anions), which have square planar molecular geometry. The Au–Cl distances are around 2.28 Å. Other d complexes adopt similar structures, e.g. tetrachloroplatinate(II) Potassium tetrachloroplatinate|. | 4 | Acids + Bases |
Cathode-ray tubes produce signal-generated light patterns in a (typically) round or rectangular format. Bulky CRTs were used in the black-and-white household television (TV) sets that became popular in the 1950s, as well as first-generation, tube-based color TVs, and most earlier computer monitors. CRTs have also been widely used in scientific and engineering instrumentation, such as oscilloscopes, usually with a single phosphor color, typically green. Phosphors for such applications may have long afterglow, for increased image persistence.
The phosphors can be deposited as either thin film, or as discrete particles, a powder bound to the surface. Thin films have better lifetime and better resolution, but provide less bright and less efficient image than powder ones. This is caused by multiple internal reflections in the thin film, scattering the emitted light.
White (in black-and-white): The mix of zinc cadmium sulfide and zinc sulfide silver, the is the white P4 phosphor used in black and white television CRTs. Mixes of yellow and blue phosphors are usual. Mixes of red, green and blue, or a single white phosphor, can also be encountered.
Red: Yttrium oxide-sulfide activated with europium is used as the red phosphor in color CRTs. The development of color TV took a long time due to the search for a red phosphor. The first red emitting rare-earth phosphor, YVO:Eu, was introduced by Levine and Palilla as a primary color in television in 1964. In single crystal form, it was used as an excellent polarizer and laser material.
Yellow: When mixed with cadmium sulfide, the resulting zinc cadmium sulfide , provides strong yellow light.
Green: Combination of zinc sulfide with copper, the P31 phosphor or , provides green light peaking at 531 nm, with long glow.
Blue: Combination of zinc sulfide with few ppm of silver, the ZnS:Ag, when excited by electrons, provides strong blue glow with maximum at 450 nm, with short afterglow with 200 nanosecond duration. It is known as the P22B phosphor. This material, zinc sulfide silver, is still one of the most efficient phosphors in cathode-ray tubes. It is used as a blue phosphor in color CRTs.
The phosphors are usually poor electrical conductors. This may lead to deposition of residual charge on the screen, effectively decreasing the energy of the impacting electrons due to electrostatic repulsion (an effect known as "sticking"). To eliminate this, a thin layer of aluminium (about 100 nm) is deposited over the phosphors, usually by vacuum evaporation, and connected to the conductive layer inside the tube. This layer also reflects the phosphor light to the desired direction, and protects the phosphor from ion bombardment resulting from an imperfect vacuum.
To reduce the image degradation by reflection of ambient light, contrast can be increased by several methods. In addition to black masking of unused areas of screen, the phosphor particles in color screens are coated with pigments of matching color. For example, the red phosphors are coated with ferric oxide (replacing earlier Cd(S,Se) due to cadmium toxicity), blue phosphors can be coated with marine blue (CoO·nalumina|) or ultramarine (). Green phosphors based on ZnS:Cu do not have to be coated due to their own yellowish color. | 0 | Luminescence |
The live birth rate is the percentage of all IVF cycles that lead to a live birth. This rate does not include miscarriage or stillbirth; multiple-order births, such as twins and triplets, are counted as one pregnancy. A 2019 summary compiled by the Society for Assisted Reproductive Technology (SART) which reports the average IVF success rates in the United States per age group using non-donor eggs compiled the following data:
In 2006, Canadian clinics reported a live birth rate of 27%. Birth rates in younger patients were slightly higher, with a success rate of 35.3% for those 21 and younger, the youngest group evaluated. Success rates for older patients were also lower and decrease with age, with 37-year-olds at 27.4% and no live births for those older than 48, the oldest group evaluated. Some clinics exceeded these rates, but it is impossible to determine if that is due to superior technique or patient selection, since it is possible to artificially increase success rates by refusing to accept the most difficult patients or by steering them into oocyte donation cycles (which are compiled separately). Further, pregnancy rates can be increased by the placement of several embryos at the risk of increasing the chance for multiples.
Because not each IVF cycle that is started will lead to oocyte retrieval or embryo transfer, reports of live birth rates need to specify the denominator, namely IVF cycles started, IVF retrievals, or embryo transfers. The SART summarised 2008–9 success rates for US clinics for fresh embryo cycles that did not involve donor eggs and gave live birth rates by the age of the prospective mother, with a peak at 41.3% per cycle started and 47.3% per embryo transfer for patients under 35 years of age.
IVF attempts in multiple cycles result in increased cumulative live birth rates. Depending on the demographic group, one study reported 45% to 53% for three attempts, and 51% to 71% to 80% for six attempts.
Effective from 15 February 2021 the majority of Australian IVF clinics publish their individual success rate online via YourIVFSuccess.com.au. This site also contains a predictor tool. | 1 | Cryobiology |
Pre-bioprinting is the process of creating a model that the printer will later create and choosing the materials that will be used. One of the first steps is to obtain a biopsy of the organ, to sample cells. Common technologies used for bioprinting are computed tomography (CT) and magnetic resonance imaging (MRI). To print with a layer-by-layer approach, tomographic reconstruction is done on the images. The now-2D images are then sent to the printer to be made. Once the image is created, certain cells are isolated and multiplied. These cells are then mixed with a special liquefied material that provides oxygen and other nutrients to keep them alive. This aggregation of cells does not require a scaffold, and is required for placing in the tubular-like tissue fusion for processes such as extrusion. | 2 | Tissue Engineering |
Matteucci effect is one of the magnetomechanical effects, which is thermodynamically inverse to Wiedemann effect. This effect was described by Carlo Matteucci in 1858. It is observable in amorphous wires with helical domain structure, which can be obtained by twisting the wire, or annealing under twist. The effect is most distinct in the so-called dwarven alloys (called so because of the historical cobalt element etymology), with cobalt as main substituent. | 7 | Magnetic Ordering |
RO removes both harmful contaminants and desirable minerals. Some studies report some relation between long-term health effects and consumption of water low on calcium and magnesium, although these studies are of low quality. | 5 | Separation Processes |
In general case LLE (2) is nonintegrable. But it admits the two integrable reductions:
: a) in the 1+1 dimensions, that is Eq. (3), it is integrable
: b) when . In this case the (1+1)-dimensional LLE (3) turns into the continuous classical Heisenberg ferromagnet equation (see e.g. Heisenberg model (classical)) which is already integrable. | 7 | Magnetic Ordering |
Ultraviolet (UV) light is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights.
The photons of ultraviolet have greater energy than those of visible light, from about 3.1 to 12 electron volts, around the minimum energy required to ionize atoms. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack sufficient energy, it can induce chemical reactions and cause many substances to glow or fluoresce. Many practical applications, including chemical and biological effects, are derived from the way that UV radiation can interact with organic molecules. These interactions can involve absorption or adjusting energy states in molecules, but do not necessarily involve heating. Short-wave ultraviolet light is ionizing radiation. Consequently, short-wave UV damages DNA and sterilizes surfaces with which it comes into contact.
For humans, suntan and sunburn are familiar effects of exposure of the skin to UV light, along with an increased risk of skin cancer. The amount of UV light produced by the Sun means that the Earth would not be able to sustain life on dry land if most of that light were not filtered out by the atmosphere. More energetic, shorter-wavelength "extreme" UV below 121 nm ionizes air so strongly that it is absorbed before it reaches the ground. However, ultraviolet light (specifically, UVB) is also responsible for the formation of vitamin D in most land vertebrates, including humans. The UV spectrum, thus, has effects both beneficial and detrimental to life.
The lower wavelength limit of the visible spectrum is conventionally taken as 400 nm, so ultraviolet rays are not visible to humans, although people can sometimes perceive light at shorter wavelengths than this. Insects, birds, and some mammals can see near-UV (NUV), i.e., slightly shorter wavelengths than what humans can see. | 8 | Ultraviolet Radiation |