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** Based on F.W. Astons measurements of the masses of low-mass elements and Einsteins discovery that E=mc, Arthur Eddington proposes that large amounts of energy released by fusing small nuclei together provides the energy source that powers the stars.
** Henry Norris Russell notes that the relationship in the Hertzsprung–Russell diagram suggests a hot core rather than burning throughout the star. Eddington uses this to calculate that the core would have to be about 40 million Kelvin. This was a matter of some debate at the time, because the value is much higher than what observations suggest, which is about one-third to one-half that value.
** George Gamow introduces the mathematical basis for quantum tunnelling.
** Atkinson and Houtermans provide the first calculations of the rate of nuclear fusion in stars. Based on Gamows tunnelling, they show fusion can occur at lower energies than previously believed. When used with Eddingtons calculations of the required fusion rates in stars, their calculations demonstrate this would occur at the lower temperatures that Eddington had calculated. | 3 | Nuclear Fusion |
Currently, the sole method for treatment for those in organ failure is to await a transplant from a living or recently deceased donor. In the United States alone, there are over 100,000 patients on the organ transplant list waiting for donor organs to become available. Patients on the donor list can wait days, weeks, months, or even years for a suitable organ to become available. The average wait time for some common organ transplants are as follows: four months for a heart or lung, eleven months for a liver, two years for a pancreas, and five years for a kidney. This is a significant increase from the 1990s, when a patient could wait as little as five weeks for a heart. These extensive wait times are due to a shortage of organs as well as the requirement for finding an organ that is suitable for the recipient. An organ is deemed suitable for a patient based on blood type, comparable body size between donor and recipient, the severity of the patients medical condition, the length of time the patient has been waiting for an organ, patient availability (i.e. ability to contact patient, if patient has an infection), the proximity of the patient to the donor, and the viability time of the donor organ. In the United States, 20 people die everyday waiting for organs. 3D organ printing has the potential to remove both these issues; if organs could be printed as soon as there is need, there would be no shortage. Additionally, seeding printed organs with a patients own cells would eliminate the need to screen donor organs for compatibility. | 2 | Tissue Engineering |
Hypothermia usually occurs from exposure to low temperatures, and is frequently complicated by alcohol consumption. Any condition that decreases heat production, increases heat loss, or impairs thermoregulation, however, may contribute. Thus, hypothermia risk factors include: substance use disorders (including alcohol use disorder), homelessness, any condition that affects judgment (such as hypoglycemia), the extremes of age, poor clothing, chronic medical conditions (such as hypothyroidism and sepsis), and living in a cold environment. Hypothermia occurs frequently in major trauma, and is also observed in severe cases of anorexia nervosa. Hypothermia is also associated with worse outcomes in people with sepsis. While most people with sepsis develop fevers (elevated body temperature), some develop hypothermia.
In urban areas, hypothermia frequently occurs with chronic cold exposure, such as in cases of homelessness, as well as with immersion accidents involving drugs, alcohol or mental illness. While studies have shown that people experiencing homelessness are at risk of premature death from hypothermia, the true incidence of hypothermia-related deaths in this population is difficult to determine. In more rural environments, the incidence of hypothermia is higher among people with significant comorbidities and less able to move independently. With rising interest in wilderness exploration, and outdoor and water sports, the incidence of hypothermia secondary to accidental exposure may become more frequent in the general population. | 1 | Cryobiology |
Pan-O-GlcNAc antibodies that recognize the O-GlcNAc modification largely irrespective of the modified proteins identity are commonly used. These include RL2, an IgG antibody raised against O-GlcNAcylated nuclear pore complex proteins, and CTD110.6, an IgM antibody raised against an immunogenic peptide with a single serine O-GlcNAc modification. Other O'-GlcNAc-specific antibodies have been reported and demonstrated to have some dependence on the identity of the modified protein. | 6 | Carbohydrates |
Perfusion storage methods can mechanically injury the vascular endothelium of the kidney, which leads to arterial thrombosis or fibrin deposition after reimplantation. Hill noted that, in human kidneys, fibrin deposition in the glomerulus after reimplantation and postoperative function, correlated with the length of perfusion storage. He had taken biopsies at revascularisation from human kidneys preserved by perfusion or ice storage, and showed by electron microscopy that endothelial disruption only occurred in those kidneys that had been perfused. Biopsies taken one hour after revascularisation showed platelets and fibrin adherent to any areas of denuded vascular basement membrane. A different type of vascular damage was described by Sheil who showed how a jet lesion could be produced distal to the cannula tied into the renal artery, leading to arterial thrombosis approximately 1 cm distal to the cannula site. | 1 | Cryobiology |
Solid carbon dioxide (dry ice) sublimes rapidly along the solid-gas boundary (sublimation point) below the triple point (e.g., at the temperature of −78.5 °C, at atmospheric pressure), whereas its melting into liquid CO can occur along the solid-liquid boundary (melting point) at pressures and temperatures above the triple point (i.e., 5.1 atm, −56.6 °C). | 5 | Separation Processes |
The stilbenoids are naturally occurring stilbene derivatives. Examples include resveratrol and its cousin, pterostilbene. The stilbestrols, which are structurally but not synthetically related to (E)-stilbene, exhibit estrogenic activity. Members of this group include diethylstilbestrol, fosfestrol, and dienestrol. Some such derivative are produced by condensation of coenzyme A derivatives of cinnamic acid or 4-hydroxycinnamic acid and the malonic acid. | 0 | Luminescence |
It is not necessary that the embryo transfer be performed on the female who provided the eggs. Thus another female whose uterus is appropriately prepared can receive the embryo and become pregnant.
Embryo transfer may be used where a woman who has eggs but no uterus and wants to have a biological baby; she would require the help of a gestational carrier or surrogate to carry the pregnancy. Also, a woman who has no eggs but a uterus may utilize egg donor IVF, in which case another woman would provide eggs for fertilization and the resulting embryos are placed into the uterus of the patient. Fertilization may be performed using the womans partners sperm or by using donor sperm. Spare embryos which are created for another couple undergoing IVF treatment but which are then surplus to that couples needs may also be transferred (called embryo donation). Embryos may be specifically created by using eggs and sperm from donors and these can then be transferred into the uterus of another woman. A surrogate may carry a baby produced by embryo transfer for another couple, even though neither she nor the commissioning' couple is biologically related to the child. Third party reproduction is controversial and regulated in many countries. Persons entering gestational surrogacy arrangements must make sense of an entirely new type of relationship that does not fit any of the traditional scripts we use to categorize relations as kinship, friendship, romantic partnership or market relations. Surrogates have the experience of carrying a baby that they conceptualize as not of their own kin, while intended mothers have the experience of waiting through nine months of pregnancy and transitioning to motherhood from outside of the pregnant body. This can lead to new conceptualizations of body and self. | 1 | Cryobiology |
** Decision to construct the National Ignition Facility "beamlet" laser at LLNL is made.
** The START Tokamak fusion experiment begins in Culham. The experiment would eventually achieve a record beta (plasma pressure compared to magnetic field pressure) of 40% using a neutral beam injector. It was the first design that adapted the conventional toroidal fusion experiments into a tighter spherical design.
** The JT-60 tokamak was upgraded to JT-60U in March.
** The Engineering Design Activity for the ITER starts with participants EURATOM, Japan, Russia and United States. It ended in 2001.
** The United States and the former republics of the Soviet Union cease nuclear weapons testing.
** The TFTR tokamak at Princeton (PPPL) experiments with a 50% deuterium, 50% tritium mix, eventually producing as much as 10 megawatts of power from a controlled fusion reaction.
** NIF Beamlet laser is completed and begins experiments validating the expected performance of NIF.
** The USA declassifies information about indirectly driven (hohlraum) target design.
** Comprehensive European-based study of HIF driver begins, centered at the Gesellschaft für Schwerionenforschung (GSI) and involving 14 laboratories, including USA and Russia. The Heavy Ion Driven Inertial Fusion (HIDIF) study will be completed in 1997.
** A record is reached at Tore Supra: a plasma duration of two minutes with a current of almost 1 million amperes driven non-inductively by 2.3 MW of lower hybrid frequency waves (i.e. 280 MJ of injected and extracted energy). This result was possible due to the actively cooled plasma-facing components installed in the machine.
** The JT-60U tokamak achieves extrapolated breakeven at Q = 1.05.
** The JET tokamak in the UK produces 16 MW of fusion power - this remains the world record for fusion power until 2022 when JET sets an even higher record. Four megawatts of alpha particle self-heating was achieved.
** LLNL study compared projected costs of power from ICF and other fusion approaches to the projected future costs of existing energy sources.
** Groundbreaking ceremony held for the National Ignition Facility (NIF).
** The JT-60 tokamak in Japan produced a high performance reversed shear plasma with the equivalent fusion amplification factor of 1.25 - the current world record of Q, fusion energy gain factor.
** Results of European-based study of heavy ion driven fusion power system (HIDIF, GSI-98-06) incorporates telescoping beams of multiple isotopic species. This technique multiplies the 6-D phase space usable for the design of HIF drivers.
** The United States withdraws from the ITER project.
** The START experiment is succeeded by MAST. | 3 | Nuclear Fusion |
Dry spiral separators, capable of distinguishing round particles from nonrounds, are used to sort the feed by shape. The device consists of a tower, around which is wound an inwardly inclined flight. A catchment funnel is placed around this inner flight. Round particles roll at a higher speed than other objects, and so are flung off the inner flight and into the collection funnel. Shapes which are not round enough are collected at the bottom of the flight.
Separators of this type may be used for removing weed seeds from the intended harvest, or to remove deformed lead shot. | 5 | Separation Processes |
As the temperature decreases, further physiological systems falter and heart rate, respiratory rate, and blood pressure all decrease. This results in an expected heart rate in the 30s at a temperature of .
There is often cold, inflamed skin, hallucinations, lack of reflexes, fixed dilated pupils, low blood pressure, pulmonary edema, and shivering is often absent. Pulse and respiration rates decrease significantly, but fast heart rates (ventricular tachycardia, atrial fibrillation) can also occur. Atrial fibrillation is not typically a concern in and of itself. | 1 | Cryobiology |
A Woods lamp may be used to rapidly assess whether an individual is suffering from ethylene glycol poisoning as a consequence of antifreeze ingestion. Manufacturers of ethylene glycol-containing antifreezes commonly add fluorescein, which causes the patients urine to fluoresce under Wood's lamp. | 8 | Ultraviolet Radiation |
Additionally the Weerman degradation could be executed with α,β-unsaturated carbonic acid amides. For example, acrylamide. | 6 | Carbohydrates |
Rotary vacuum drum filter (RVDF), patented in 1872, is one of the oldest filters used in the industrial liquid-solids separation. It offers a wide range of industrial processing flow sheets and provides a flexible application of dewatering, washing and/or clarification.
A rotary vacuum filter consists of a large rotating drum covered by a cloth. The drum is suspended on an axial over a trough containing liquid or solids slurry with approximately 50-80% of the screen area immersed in the slurry.
As the drum rotates into and out of the trough, the slurry is sucked on the surface of the cloth and rotated out of the liquid or solids suspension as a cake. When the cake is rotating out, it is dewatered in the drying zone. The cake is dry because the vacuum drum is continuously sucking the cake and taking the water out of it. At the final step of the separation, the cake is discharged as solids products and the drum rotates continuously to another separation cycle. | 5 | Separation Processes |
Medical organizations recommend that patients protect themselves from UV radiation by using sunscreen. Five sunscreen ingredients have been shown to protect mice against skin tumors. However, some sunscreen chemicals produce potentially harmful substances if they are illuminated while in contact with living cells. The amount of sunscreen that penetrates into the lower layers of the skin may be large enough to cause damage.
Sunscreen reduces the direct DNA damage that causes sunburn, by blocking UV‑B, and the usual SPF rating indicates how effectively this radiation is blocked. SPF is, therefore, also called UVB-PF, for "UV‑B protection factor". This rating, however, offers no data about important protection against UVA, which does not primarily cause sunburn but is still harmful, since it causes indirect DNA damage and is also considered carcinogenic. Several studies suggest that the absence of UV‑A filters may be the cause of the higher incidence of melanoma found in sunscreen users compared to non-users. Some sunscreen lotions contain titanium dioxide, zinc oxide, and avobenzone, which help protect against UV‑A rays.
The photochemical properties of melanin make it an excellent photoprotectant. However, sunscreen chemicals cannot dissipate the energy of the excited state as efficiently as melanin and therefore, if sunscreen ingredients penetrate into the lower layers of the skin, the amount of reactive oxygen species may be increased. The amount of sunscreen that penetrates through the stratum corneum may or may not be large enough to cause damage.
In an experiment by Hanson et al. that was published in 2006, the amount of harmful reactive oxygen species (ROS) was measured in untreated and in sunscreen treated skin. In the first 20 minutes, the film of sunscreen had a protective effect and the number of ROS species was smaller. After 60 minutes, however, the amount of absorbed sunscreen was so high that the amount of ROS was higher in the sunscreen-treated skin than in the untreated skin. The study indicates that sunscreen must be reapplied within 2 hours in order to prevent UV light from penetrating to sunscreen-infused live skin cells. | 8 | Ultraviolet Radiation |
The Beckett skimmer has some similarities to the downdraft skimmer but introduced a foam nozzle to produce the flow of air bubbles. The name Beckett comes from the patented foam nozzle developed and sold by the Beckett Corporation (United States), although similar foam nozzle designs are sold by other companies outside the United States (e.g. Sicce (Italy)). Instead of using the plastic media that is found in downdraft skimmer designs, the Beckett skimmer uses design concepts from previous generations of skimmers, specifically the downdraft skimmer and the venturi skimmer (the Beckett 1408 Foam Nozzle is a modified 4 port venturi) to produce a hybrid that is capable of using powerful pressure rated water pumps and quickly processing large amounts of aquarium water in a short period of time. Commercial Beckett skimmers come in single Beckett, dual Beckett, and quad Beckett designs. Well engineered Beckett skimmers are quiet and reliable. Due to the advances in pump technologies and introduction of DC pumps, the concerns of powerful pumps taking up additional space, introducing additional noise, and using more electricity have all been alleviated. Unlike the Downdraft and Spray Induction skimmers, Beckett skimmer designs are produced by a number of companies in the United States and elsewhere and are not known to be restricted by patents. | 5 | Separation Processes |
Ex situ conservation, while helpful in humankinds efforts to sustain and protect our environment, is rarely enough to save a species from extinction. It is to be used as a last resort, or as a supplement to in situ conservation because it cannot recreate the habitat as a whole: the entire genetic variation of a species, its symbiotic counterparts, or those elements which, over time, might help a species adapt to its changing surroundings. Instead, ex situ conservation removes the species from its natural ecological contexts, preserving it under semi-isolated conditions whereby natural evolution and adaptation processes are either temporarily halted or altered by introducing the specimen to an unnatural habitat. In the case of cryogenic storage methods, the preserved specimens adaptation processes are (quite literally) frozen altogether. The downside to this is that, when re-released, the species may lack the genetic adaptations and mutations which would allow it to thrive in its ever-changing natural habitat.
Furthermore, ex situ conservation techniques are often costly, with cryogenic storage being economically infeasible in most cases since species stored in this manner cannot provide a profit but instead slowly drain the financial resources of the government or organization determined to operate them. Seedbanks are ineffective for certain plant genera with recalcitrant seeds that do not remain fertile for long periods of time. Diseases and pests foreign to the species, to which the species has no natural defense, may also cripple crops of protected plants in ex situ plantations and in animals living in ex situ breeding grounds. These factors, combined with the specific environmental needs of many species, some of which are nearly impossible to recreate by man, make ex situ conservation impossible for a great number of the world's endangered flora and fauna. | 1 | Cryobiology |
The vacuum ultraviolet (V‑UV) band (100–200 nm) can be generated by non-linear 4 wave mixing in gases by sum or difference frequency mixing of 2 or more longer wavelength lasers. The generation is generally done in gasses (e.g. krypton, hydrogen which are two-photon resonant near 193 nm) or metal vapors (e.g. magnesium). By making one of the lasers tunable, the V‑UV can be tuned. If one of the lasers is resonant with a transition in the gas or vapor then the V‑UV production is intensified. However, resonances also generate wavelength dispersion, and thus the phase matching can limit the tunable range of the 4 wave mixing. Difference frequency mixing (i.e., ) has an advantage over sum frequency mixing because the phase matching can provide greater tuning.
In particular, difference frequency mixing two photons of an (193 nm) excimer laser with a tunable visible or near IR laser in hydrogen or krypton provides resonantly enhanced tunable V‑UV covering from 100 nm to 200 nm. Practically, the lack of suitable gas / vapor cell window materials above the lithium fluoride cut-off wavelength limit the tuning range to longer than about 110 nm. Tunable V‑UV wavelengths down to 75 nm was achieved using window-free configurations. | 8 | Ultraviolet Radiation |
An acid attack, also called acid throwing, vitriol attack, or vitriolage, is a form of violent assault involving the act of throwing acid or a similarly corrosive substance onto the body of another "with the intention to disfigure, maim, torture, or kill". Perpetrators of these attacks throw corrosive liquids at their victims, usually at their faces, burning them, and damaging skin tissue, often exposing and sometimes dissolving the bones. Acid attacks can lead to permanent, partial, or complete blindness.
The most common types of acid used in these attacks are sulfuric and nitric acid. Hydrochloric acid is sometimes used but is much less damaging. Aqueous solutions of strongly alkaline materials, such as caustic soda (sodium hydroxide) or ammonia, are used as well, particularly in areas where strong acids are controlled substances.
The long-term consequences of these attacks may include blindness, as well as eye burns, with severe permanent scarring of the face and body, along with far-reaching social, psychological, and economic difficulties.
Today, acid attacks are reported in many parts of the world, though more commonly in developing countries. Between 1999 and 2013, a total of 3,512 Bangladeshi people were attacked with acid, with the rate of cases declining by 15–20% every year since 2002 based on strict legislation against perpetrators and regulation of acid sales. In India, acid attacks are at an all-time high and increasing every year, with 250–300 reported incidents every year, while the "actual number could exceed 1,000, according to Acid Survivors' Trust International".
Although acid attacks occur all over the world, this type of violence is most common in South Asia. Statistics from Acid Survivors Trust International (ASTI) suggest that 80% of victims worldwide are women. | 4 | Acids + Bases |
A cerebral organoid describes artificially grown, in vitro, miniature organs resembling the brain. Cerebral organoids are created by culturing human pluripotent stem cells in a three-dimensional structure using rotational bioreactor and develop over the course of months. The procedure has potential applications in the study of brain development, physiology and function. Cerebral organoids may experience "simple sensations" in response to external stimulation and neuroscientists are among those expressing concern that such organs could develop sentience. They propose that further evolution of the technique needs to be subject to a rigorous oversight procedure. In 2023, researchers have built a hybrid biocomputer that combines a laboratory-grown human brain organoids with conventional circuits, and can complete tasks such as voice recognition. Cerebral Organoids are currently being used to research and develop Organoid Intelligence (OI) technologies. | 2 | Tissue Engineering |
The inertia of a collapsing bubble generates high pressures and temperatures capable of ionizing a small fraction of the noble gas within the volume of the bubble. This small fraction of ionized gas is transparent and allows for volume emission to be detected. Free electrons from the ionized noble gas begin to interact with other neutral atoms causing thermal bremsstrahlung radiation. Surface emission emits a more intense flash of light with a longer duration and is dependent on wavelength. Experimental data suggest that only volume emission occurs in the case of sonoluminescence. As the sound wave reaches a low energy trough the bubble expands and electrons are able to recombine with free ions and halt light emission. Light pulse time is dependent on the ionization energy of the noble gas with argon having a light pulse of 160 picoseconds. | 0 | Luminescence |
Magnetostrictive position sensors use the Wiedemann effect to excite an ultrasonic pulse. Typically a small magnet is used to mark a position along a magnetostrictive wire. The magnetic field from a short current pulse in the wire combined with that from the position magnet excites the ultrasonic pulse. The time required for this pulse to travel from the point of excitation to a pickup at the end of the wire gives the position. Reflections from the other end of the wire could lead to disturbances. In order to avoid this the wire is connected to a mechanical damper that end. | 7 | Magnetic Ordering |
Laboratories have developed grading methods to judge ovocyte 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. Active efforts to develop a more accurate embryo selection analysis based on Artificial Intelligence and Deep Learning are underway. Embryo Ranking Intelligent Classification Assistant (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 |
Mixer settlers are a class of mineral process equipment used in the solvent extraction process. A mixer settler consists of a first stage that mixes the phases together followed by a quiescent settling stage that allows the phases to separate by gravity. | 5 | Separation Processes |
Radical Polymerization is used in the curing of acrylic resins in the presence of UV in the industry. Light energy from UV breaks apart photoinitiaters, forming radicals. The radical then react with the polymers, forming polymers with radical groups that then react with additional monomers. The monomer chain extends until it reaches another polymer and reacts with the polymer. Polymers will form with monomer bridges between them, thus leading to a cross-linked network. | 8 | Ultraviolet Radiation |
A cryoprotectant is a substance used to protect biological tissue from freezing damage (i.e. that due to ice formation). Arctic and Antarctic insects, fish and amphibians create cryoprotectants (antifreeze compounds and antifreeze proteins) in their bodies to minimize freezing damage during cold winter periods. Cryoprotectants are also used to preserve living materials in the study of biology and to preserve food products.
For years, glycerol has been used in cryobiology as a cryoprotectant for blood cells and bull sperm, allowing storage in liquid nitrogen at temperatures around −196 °C. However, glycerol cannot be used to protect whole organs from damage. Instead, many biotechnology companies are researching the development of other cryoprotectants more suitable for such uses. A successful discovery may eventually make possible the bulk cryogenic storage (or "banking") of transplantable human and xenobiotic organs. A substantial step in that direction has already occurred. Twenty-First Century Medicine has vitrified a rabbit kidney to -135 °C with their proprietary vitrification cocktail. Upon rewarming, the kidney was successfully transplanted into a rabbit, with complete functionality and viability, able to sustain the rabbit indefinitely as the sole functioning kidney. | 1 | Cryobiology |
Low-pressure mercury lamps are very similar to a fluorescent lamp, with a wavelength of 253.7 nm (1182.5 THz).
The most common form of germicidal lamp looks similar to an ordinary fluorescent lamp but the tube contains no fluorescent phosphor. In addition, rather than being made of ordinary borosilicate glass, the tube is made of fused quartz or vycor 7913 glass. These two changes combine to allow the 253.7 nm ultraviolet light produced by the mercury arc to pass out of the lamp unmodified (whereas, in common fluorescent lamps, it causes the phosphor to fluoresce, producing visible light). Germicidal lamps still produce a small amount of visible light due to other mercury radiation bands.
An older design looks like an incandescent lamp but with the envelope containing a few droplets of mercury. In this design, the incandescent filament heats the mercury, producing a vapor which eventually allows an arc to be struck, short circuiting the incandescent filament.
As with all gas-discharge lamps, low- and high-pressure mercury lamps exhibit negative resistance and require the use of an external ballast to regulate the current flow. The older lamps that resembled an incandescent lamp were often operated in series with an ordinary 40 W incandescent "appliance" lamp; the incandescent lamp acted as the ballast for the germicidal lamp. | 8 | Ultraviolet Radiation |
A hysteresis is sometimes intentionally added to computer algorithms. The field of user interface design has borrowed the term hysteresis to refer to times when the state of the user interface intentionally lags behind the apparent user input. For example, a menu that was drawn in response to a mouse-over event may remain on-screen for a brief moment after the mouse has moved out of the trigger region and the menu region. This allows the user to move the mouse directly to an item on the menu, even if part of that direct mouse path is outside of both the trigger region and the menu region. For instance, right-clicking on the desktop in most Windows interfaces will create a menu that exhibits this behavior. | 7 | Magnetic Ordering |
In 2017, a Chinese Irish woman was targeted in an attack in Blackrock, Dublin, causing facial scars and eye damage. Another foreign woman was suspected of ordering the attack.
In 2018, Lithuanian criminals threw acid at a Garda (police officer).
In April 2019 in Waterford, three teenagers were attacked by two others, who threw acid at them in a premeditated attack. All three victims suffered severe skin burns in the incident, and one, Tega Agberhiere, suffered severe injuries to his face and body and his eyesight was damaged. Nevertheless, the perpetrators merely got cautions.
On 13 June 2020, a man was attacked with acid in Garryowen, Limerick.
In December 2020, a woman threw acid at three women in a takeaway in Tallaght. | 4 | Acids + Bases |
It is the time dependence which distinguishes spin glasses from other magnetic systems.
Above the spin glass transition temperature, T, the spin glass exhibits typical magnetic behaviour (such as paramagnetism).
If a magnetic field is applied as the sample is cooled to the transition temperature, magnetization of the sample increases as described by the Curie law. Upon reaching T, the sample becomes a spin glass, and further cooling results in little change in magnetization. This is referred to as the field-cooled magnetization.
When the external magnetic field is removed, the magnetization of the spin glass falls rapidly to a lower value known as the remanent magnetization.
Magnetization then decays slowly as it approaches zero (or some small fraction of the original value this remains unknown). This decay is non-exponential, and no simple function can fit the curve of magnetization versus time adequately. This slow decay is particular to spin glasses. Experimental measurements on the order of days have shown continual changes above the noise level of instrumentation.
Spin glasses differ from ferromagnetic materials by the fact that after the external magnetic field is removed from a ferromagnetic substance, the magnetization remains indefinitely at the remanent value. Paramagnetic materials differ from spin glasses by the fact that, after the external magnetic field is removed, the magnetization rapidly falls to zero, with no remanent magnetization. The decay is rapid and exponential.
If the sample is cooled below T in the absence of an external magnetic field, and a magnetic field is applied after the transition to the spin glass phase, there is a rapid initial increase to a value called the zero-field-cooled magnetization. A slow upward drift then occurs toward the field-cooled magnetization.
Surprisingly, the sum of the two complicated functions of time (the zero-field-cooled and remanent magnetizations) is a constant, namely the field-cooled value, and thus both share identical functional forms with time, at least in the limit of very small external fields. | 7 | Magnetic Ordering |
Pre-implantation genetic diagnosis (PGD) is criticised for giving select demographic groups disproportionate access to a means of creating a child possessing characteristics that they consider "ideal". Many fertile couples now demand equal access to embryonic screening so that their child can be just as healthy as one created through IVF. Mass use of PGD, especially as a means of population control or in the presence of legal measures related to population or demographic control, can lead to intentional or unintentional demographic effects such as the skewed live-birth sex ratios seen in China following implementation of its one-child policy.
While PGD was originally designed to screen for embryos carrying hereditary genetic diseases, the method has been applied to select features that are unrelated to diseases, thus raising ethical questions. Examples of such cases include the selection of embryos based on histocompatibility (HLA) for the donation of tissues to a sick family member, the diagnosis of genetic susceptibility to disease, and sex selection.
These examples raise ethical issues because of the morality of eugenics. It becomes frowned upon because of the advantage of being able to eliminate unwanted traits and selecting desired traits. By using PGD, individuals are given the opportunity to create a human life unethically and rely on science and not by natural selection.
For example, a deaf British couple, Tom and Paula Lichy, have petitioned to create a deaf baby using IVF. Some medical ethicists have been very critical of this approach. Jacob M. Appel wrote that "intentionally culling out blind or deaf embryos might prevent considerable future suffering, while a policy that allowed deaf or blind parents to select for such traits intentionally would be far more troublesome." | 1 | Cryobiology |
One approach for generating the high voltage fields needed to accelerate ions in a neutron tube is to use a pyroelectric crystal. In April 2005 researchers at UCLA demonstrated the use of a thermally cycled pyroelectric crystal to generate high electric fields in a neutron generator application. In February 2006 researchers at Rensselaer Polytechnic Institute demonstrated the use of two oppositely poled crystals for this application. Using these low-tech power supplies it is possible to generate a sufficiently high electric field gradient across an accelerating gap to accelerate deuterium ions into a deuterated target to produce the D + D fusion reaction. These devices are similar in their operating principle to conventional sealed-tube neutron generators which typically use Cockcroft–Walton type high voltage power supplies. The novelty of this approach is in the simplicity of the high voltage source. Unfortunately, the relatively low accelerating current that pyroelectric crystals can generate, together with the modest pulsing frequencies that can be achieved (a few cycles per minute) limits their near-term application in comparison with today's commercial products (see below). Also see pyroelectric fusion. | 3 | Nuclear Fusion |
DPN is a direct write technique so it can be used for top-down and bottom-up lithography applications. In top-down work, the tips are used to deliver an etch resist to a surface, which is followed by a standard etching process. In bottom-up applications, the material of interest is delivered directly to the surface via the tips. | 2 | Tissue Engineering |
Hysteresis manifests itself in state transitions when melting temperature and freezing temperature do not agree. For example, agar melts at and solidifies from . This is to say that once agar is melted at 85 °C, it retains a liquid state until cooled to 40 °C. Therefore, from the temperatures of 40 to 85 °C, agar can be either solid or liquid, depending on which state it was before. | 7 | Magnetic Ordering |
Bioinks are essential components of the bioprinting process. They are composed of living cells and enzymatic supplements to nurture an environment that supports the biological needs of the printed tissue. The environment created by the bioink allows for the cell to attach, grow, and differentiate into its adult form. Cell-encapsualting hydrogels are utilized in extrusion based bioprinting methods, while gelatin MethacryloylGelatin methacrylon (GelMA) and acellular comprised bioinks are most often used in tissue engineering techniques that require cross-linkage and precise structural integrity. It is essential for bioinks to help replicate the external cellular matrix environment that the cell would naturally occur in. | 2 | Tissue Engineering |
In the duodenum, gastric acid is neutralized by bicarbonate. This also blocks gastric enzymes that have their optima in the acid range of pH. The secretion of bicarbonate from the pancreas is stimulated by secretin. This polypeptide hormone gets activated and secreted from so-called S cells in the mucosa of the duodenum and jejunum when the pH in the duodenum falls below 4.5 to 5.0. The neutralization is described by the equation:
:HCl + NaHCO → NaCl + HCO
The carbonic acid rapidly equilibrates with carbon dioxide and water through catalysis by carbonic anhydrase enzymes bound to the gut epithelial lining, leading to a net release of carbon dioxide gas within the lumen associated with neutralisation. In the absorptive upper intestine, such as the duodenum, both the dissolved carbon dioxide and carbonic acid will tend to equilibrate with the blood, leading to most of the gas produced on neutralisation being exhaled through the lungs. | 4 | Acids + Bases |
The chute-type machine has a lower footprint and fewer moving parts which results in lower investment and operating costs. In general, it is more applicable to well liberated material and surface detection, because a double sided scanning is possible on a more reliable on the system. The applicable top size of the chute-type machine is bigger, as material handling of particles up to is only technically viable on this setup.
The cost for most average farmers and industry workers is around $500 for the study and ergonomic design of the sensor. The sensor itself is still a prototype not yet built but looking to be approved by FDA around 2003 | 5 | Separation Processes |
A hybrid scaffold is a skin substitute based on a combination of synthetic and natural materials. Examples of hybrid scaffolds are HYAFF and Laserskin. These hybrid scaffolds have been shown to have good in-vitro and in-vivo biocompatibilities and their biodegradability is controllable. | 2 | Tissue Engineering |
Post-treatment disinfection provides secondary protection against compromised membranes and downstream problems. Disinfection by means of ultraviolet (UV) lamps (sometimes called germicidal or bactericidal) may be employed to sterilize pathogens that evade the RO process. Chlorination or chloramination (chlorine and ammonia) protects against pathogens that may have lodged in the distribution system downstream. | 5 | Separation Processes |
Since HeH cannot be stored in any usable form, its chemistry must be studied by forming it in situ.
Reactions with organic substances, for example, can be studied by creating a tritium derivative of the desired organic compound. Decay of tritium to He followed by its extraction of a hydrogen atom yields HeH which is then surrounded by the organic material and will in turn react. | 4 | Acids + Bases |
The twisting of a ferromagnetic rod through which an electric current is flowing when the rod is placed in a longitudinal magnetic field. It was discovered by the German physicist Gustav Wiedemann in 1858
. The Wiedemann effect is one of the manifestations of magnetostriction in a field formed by the combination of a longitudinal magnetic field and a circular magnetic field that is created by an electric current. If the electric current (or the magnetic field) is alternating, the rod will begin torsional oscillation.
In linear approach angle of rod torsion α does not depend on its cross-section form and is defined only by current density and magnetoelastic properties of the rod:
where
* is current density;
* is magnetoelastic parameter, proportional to longitudinal magnetic field value;
* is the shear modulus. | 7 | Magnetic Ordering |
Black light is used extensively in non-destructive testing. Fluorescing fluids are applied to metal structures and illuminated with a black light which allows cracks and other weaknesses in the material to be easily detected.
In addition, if a leak is suspected in a refrigerator or an air conditioning system, a UV tracer dye can be injected into the system along with the compressor lubricant oil and refrigerant mixture. The system is then run in order to circulate the dye across the piping and components and then the system is examined with a blacklight lamp. Any evidence of fluorescent dye then pinpoints the leaking part which needs replacement. | 8 | Ultraviolet Radiation |
Hox genes play a massive role in some amphibians and reptiles in their ability to regenerate lost limbs, especially HoxA and HoxD genes.
If the processes involved in forming new tissue can be reverse-engineered into humans, it may be possible to heal injuries of the spinal cord or brain, repair damaged organs and reduce scarring and fibrosis after surgery. Despite the large conservation of the Hox genes through evolution, mammals and humans specifically cannot regenerate any of their limbs. This raises a question as to why humans which also possess an analog to these genes cannot regrow and regenerate limbs. Beside the lack of specific growth factor, studies have shown that something as small as base pair differences between amphibian and human Hox analogs play a crucial role in human inability to reproduce limbs. Undifferentiated stem cells and the ability to have polarity in tissues is vital to this process. | 2 | Tissue Engineering |
The first time scientists were able to grow artificial hair follicles from stem cells was in 2010. Scientists at the Berlin Technical University in Germany took animal cells and created follicles by using them. As a result, they produced follicles "thinner than normal", but they were confident they could develop the right method of cloning hair from human stem cells by 2011. They estimated that the therapy would be publicly available by 2015 as they were already preparing for the clinical trials. Scientists working on the project said if the treatment was finished, it would mean a cure for approximately 80 percent of those who suffer from hair loss.
The university was working together with Intercytex and several other research teams, but they encountered several problems. One of them was that the multiplication process was not efficient enough. They were only able to clone one or two follicles from an extracted hair but for the process to be efficient this number should have been around 1000. There was no indication that researchers were able to overcome this obstacle. | 2 | Tissue Engineering |
Application of this discharge are usually seen where production of filter cakes that blind the filter media thoroughly and processes that have low solid concentration slurry. Pre coat discharge is used if slurry with very low solid concentration slurry is used that resulted in difficult cake formation or if the slurry is difficult to filter to produce cake . | 5 | Separation Processes |
The evolution of early reproductive proteins and enzymes is attributed in modern models of evolutionary theory to ultraviolet radiation. UVB causes thymine base pairs next to each other in genetic sequences to bond together into thymine dimers, a disruption in the strand that reproductive enzymes cannot copy. This leads to frameshifting during genetic replication and protein synthesis, usually killing the cell. Before formation of the UV-blocking ozone layer, when early prokaryotes approached the surface of the ocean, they almost invariably died out. The few that survived had developed enzymes that monitored the genetic material and removed thymine dimers by nucleotide excision repair enzymes. Many enzymes and proteins involved in modern mitosis and meiosis are similar to repair enzymes, and are believed to be evolved modifications of the enzymes originally used to overcome DNA damages caused by UV. | 8 | Ultraviolet Radiation |
Bussard Ramjets are common plot devices in science fiction.
Larry Niven uses them in his Known Space setting to propel interstellar flight. Following a standard hi-tech faster/cheaper/better learning curve, he started with robot probes during the early stages of interstellar colonization and eventually plotted them as affordable to wealthy individuals relocating their families off a too-crowded Earth (in "The Ethics of Madness"). Niven also employed Bussard Ramjets as the propulsion / stabilizing engine of the Ringworld (four novels), which were also set in Known Space.
In the Star Trek universe, a variation called the Bussard Hydrogen Collector or Bussard Ramscoop appears as part of the matter/antimatter propulsion system that allows Starfleet ships to travel faster than the speed of light. The ramscoops attach to the front of the warp nacelles, and when the ships internal supply of deuterium runs low, they collect interstellar hydrogen and convert it to deuterium and anti-deuterium for use as the primary fuel in a starships warp drive. | 3 | Nuclear Fusion |
A 2009 statement from the ASRM found no persuasive evidence that children are harmed or disadvantaged solely by being raised by single parents, unmarried parents, or homosexual parents. It did not support restricting access to assisted reproductive technologies on the basis of a prospective parents marital status or sexual orientation. A 2018 study found that childrens psychological well-being did not differ when raised by either same-sex parents or heterosexual parents, even finding that psychological well-being was better amongst children raised by same-sex parents.
Ethical concerns include reproductive rights, the welfare of offspring, nondiscrimination against unmarried individuals, homosexual, and professional autonomy.
A controversy in California focused on the question of whether physicians opposed to same-sex relationships should be required to perform IVF for a lesbian couple. Guadalupe T. Benitez, a lesbian medical assistant from San Diego, sued doctors Christine Brody and Douglas Fenton of the North Coast Womans Care Medical Group after Brody told her that she had "religious-based objections to treating her and homosexuals in general to help them conceive children by artificial insemination," and Fenton refused to authorise a refill of her prescription for the fertility drug Clomid on the same grounds. The California Medical Association had initially sided with Brody and Fenton, but the case, North Coast Womens Care Medical Group v. Superior Court, was decided unanimously by the California State Supreme Court in favour of Benitez on 19 August 2008.
Nadya Suleman came to international attention after having twelve embryos implanted, eight of which survived, resulting in eight newborns being added to her existing six-child family. The Medical Board of California sought to have fertility doctor Michael Kamrava, who treated Suleman, stripped of his licence. State officials allege that performing Sulemans procedure is evidence of unreasonable judgment, substandard care, and a lack of concern for the eight children she would conceive and the six she was already struggling to raise. On 1 June 2011 the Medical Board issued a ruling that Kamravas medical licence be revoked effective 1 July 2011. | 1 | Cryobiology |
Lasers have been used to indirectly generate non-coherent extreme UV (E‑UV) radiation at 13.5 nm for extreme ultraviolet lithography. The E‑UV is not emitted by the laser, but rather by electron transitions in an extremely hot tin or xenon plasma, which is excited by an excimer laser. This technique does not require a synchrotron, yet can produce UV at the edge of the X‑ray spectrum. Synchrotron light sources can also produce all wavelengths of UV, including those at the boundary of the UV and X‑ray spectra at 10 nm. | 8 | Ultraviolet Radiation |
HeH has long been conjectured since the 1970s to exist in the interstellar medium. Its first detection, in the nebula NGC 7027, was reported in an article published in the journal Nature in April 2019. | 4 | Acids + Bases |
The biocompatibility of surgically implanted foreign biomaterial refers to the interactions between the biomaterial and the host body tissue. Cell line as well as cell type such as fibroblasts can largely impact tissue responses towards implanted foreign devices by changing cell morphology. Thus the cell source as well as protein adsorption, which is dependent on biomaterial surface property, play a crucial role in tissue response and cell infiltration at the scaffold site. | 2 | Tissue Engineering |
During differentiation, pluripotent cells make a number of developmental decisions to generate first the three germ layers (ectoderm, mesoderm and endoderm) of the embryo and intermediate progenitors, followed by subsequent decisions or check points, giving rise to all the bodys mature tissues. The differentiation process can be modeled as sequence of binary decisions based on probabilistic or stochastic models. Developmental biology and embryology provides the basic knowledge of the cell types differentiation through mutation analysis, lineage tracing, embryo micro-manipulation and gene expression studies. Cell differentiation and tissue organogenesis involve a limited set of developmental signaling pathways. It is thus possible to direct cell fate by controlling cell decisions through extracellular signaling, mimicking developmental signals. | 2 | Tissue Engineering |
Thermonuclear fusion is the process of atomic nuclei combining or "fusing" using high temperatures to drive them close enough together for this to become possible. Such temperatures cause the matter to become a plasma and, if confined, fusion reactions may occur due to collisions with extreme thermal kinetic energies of the particles. There are two forms of thermonuclear fusion: uncontrolled, in which the resulting energy is released in an uncontrolled manner, as it is in thermonuclear weapons ("hydrogen bombs") and in most stars; and controlled, where the fusion reactions take place in an environment allowing some or all of the energy released to be harnessed for constructive purposes.
Temperature is a measure of the average kinetic energy of particles, so by heating the material it will gain energy. After reaching sufficient temperature, given by the Lawson criterion, the energy of accidental collisions within the plasma is high enough to overcome the Coulomb barrier and the particles may fuse together.
In a deuterium–tritium fusion reaction, for example, the energy necessary to overcome the Coulomb barrier is 0.1 MeV. Converting between energy and temperature shows that the 0.1 MeV barrier would be overcome at a temperature in excess of 1.2 billion kelvin.
There are two effects that are needed to lower the actual temperature. One is the fact that temperature is the average kinetic energy, implying that some nuclei at this temperature would actually have much higher energy than 0.1 MeV, while others would be much lower. It is the nuclei in the high-energy tail of the velocity distribution that account for most of the fusion reactions. The other effect is quantum tunnelling. The nuclei do not actually have to have enough energy to overcome the Coulomb barrier completely. If they have nearly enough energy, they can tunnel through the remaining barrier. For these reasons fuel at lower temperatures will still undergo fusion events, at a lower rate.
Thermonuclear fusion is one of the methods being researched in the attempts to produce fusion power. If thermonuclear fusion becomes favorable to use, it would significantly reduce the world's carbon footprint. | 3 | Nuclear Fusion |
Radioluminescent paint was invented in 1908 by Sabin Arnold von Sochocky and originally incorporated radium-226. Radium paint was widely used for 40 years on the faces of watches, compasses, and aircraft instruments, so they could be read in the dark. Radium is a radiological hazard, emitting gamma rays that can penetrate a glass watch dial and into human tissue. During the 1920s and 1930s, the harmful effects of this paint became increasingly clear. A notorious case involved the "Radium Girls", a group of women who painted watchfaces and later suffered adverse health effects from ingestion, in many cases resulting in death. In 1928, Dr von Sochocky himself died of aplastic anemia as a result of radiation exposure. Thousands of legacy radium dials are still owned by the public and the paint can still be dangerous if ingested in sufficient quantities, which is why it has been banned in many countries.
Radium paint used zinc sulfide phosphor, usually trace metal doped with an activator, such as copper (for green light), silver (blue-green), and more rarely copper-magnesium (for yellow-orange light). The phosphor degrades relatively fast and the dials lose luminosity in several years to a few decades; clocks and other devices available from antique shops and other sources therefore are not luminous any more. However, due to the long 1600 year half-life of the Ra-226 isotope they are still radioactive and can be identified with a Geiger counter.
The dials can be renovated by application of a very thin layer of fresh phosphor, without the radium content (with the original material still acting as the energy source); the phosphor layer has to be thin due to the light self-absorption in the material. | 0 | Luminescence |
Showy Indian clover, Trifolium amoenum, is an example of a species that was thought to be extinct, but was rediscovered in 1993 in the form of a single plant at a site in western Sonoma County. Seeds were harvested and the species grown in ex situ facilities.
The Wollemi pine is another example of a plant that is being preserved via ex situ conservation, as they are being grown in nurseries to be sold to the general public.
The Orange-bellied parrot, with a wild population of 14 birds as of early February 2017, are being bred in a captive breeding program. The captive population consists of around 300 birds. | 1 | Cryobiology |
* Directed Placement – Directly print various materials onto existing nano and microstructures with nanoscale registry
* Direct Write – Maskless creation of arbitrary patterns with feature resolutions from as small as 50 nm and as large as 10 micrometres
* Biocompatible – Subcellular to nanoscale resolution at ambient deposition conditions
* Scalable – Force independent, allowing for parallel depositions | 2 | Tissue Engineering |
Ultraviolet lamps are used to sterilize workspaces and tools used in biology laboratories and medical facilities. Commercially available low-pressure mercury-vapor lamps emit about 86% of their radiation at 254 nanometers (nm), with 265 nm being the peak germicidal effectiveness curve. UV at these germicidal wavelengths damage a microorganism's DNA/RNA so that it cannot reproduce, making it harmless, (even though the organism may not be killed). Since microorganisms can be shielded from ultraviolet rays in small cracks and other shaded areas, these lamps are used only as a supplement to other sterilization techniques.
UV-C LEDs are relatively new to the commercial market and are gaining in popularity. Due to their monochromatic nature (±5 nm) these LEDs can target a specific wavelength needed for disinfection. This is especially important knowing that pathogens vary in their sensitivity to specific UV wavelengths. LEDs are mercury free, instant on/off, and have unlimited cycling throughout the day.
Disinfection using UV radiation is commonly used in wastewater treatment applications and is finding an increased usage in municipal drinking water treatment. Many bottlers of spring water use UV disinfection equipment to sterilize their water. Solar water disinfection has been researched for cheaply treating contaminated water using natural sunlight. The UV-A irradiation and increased water temperature kill organisms in the water.
Ultraviolet radiation is used in several food processes to kill unwanted microorganisms. UV can be used to pasteurize fruit juices by flowing the juice over a high-intensity ultraviolet source. The effectiveness of such a process depends on the UV absorbance of the juice.
Pulsed light (PL) is a technique of killing microorganisms on surfaces using pulses of an intense broad spectrum, rich in UV-C between 200 and 280 nm. Pulsed light works with xenon flash lamps that can produce flashes several times per second. Disinfection robots use pulsed UV.
The antimicrobial effectiveness of filtered far-UVC (222 nm) light on a range of pathogens, including bacteria and fungi showed inhibition of pathogen growth, and since it has lesser harmful effects, it provides essential insights for reliable disinfection in healthcare settings, such as hospitals and long-term care homes. UVC has also been shown to be effective at degrading SARS-CoV-2 virus. | 8 | Ultraviolet Radiation |
Recent studies on acid attacks in Cambodia found the victims were almost equally likely to be men or women (48.4% men, 51.6% women). As with India, rates of acid attacks in Cambodia have generally increased in the past decades, with a high rate of 40 cases reported for 2000 that started the increasing trend. According to the Cambodian Acid Survivors Charity, 216 acid attacks were reported from 1985 to 2009, with 236 reported victims. Jealousy and hate is the biggest motivator for acid attacks in Cambodia, as 28% of attacks reported those emotions as the cause. Such assaults were not only perpetrated by men – some reports suggest women attack other women occur more frequently than men do. Such incidents usually occur between a husband's wife and mistress to attain power and socioeconomic security.
A particularly high-profile case of this nature was the attack on Cambodian teenager Tat Marina in 1999, allegedly carried out by the jealous wife of a government official (the incident prompted a rash of copycat crimes that year, raising the number from seven in 1998 to 40 in 1999). One-third of the victims are bystanders. In Cambodia, there is only one support center that is aiming to help acid attack survivors. There they can receive medical and legal support. | 4 | Acids + Bases |
A third confinement principle is to apply a rapid pulse of energy to a large part of the surface of a pellet of fusion fuel, causing it to simultaneously "implode" and heat to very high pressure and temperature. If the fuel is dense enough and hot enough, the fusion reaction rate will be high enough to burn a significant fraction of the fuel before it has dissipated. To achieve these extreme conditions, the initially cold fuel must be explosively compressed. Inertial confinement is used in the hydrogen bomb, where the driver is x-rays created by a fission bomb. Inertial confinement is also attempted in "controlled" nuclear fusion, where the driver is a laser, ion, or electron beam, or a Z-pinch. Another method is to use conventional high explosive material to compress a fuel to fusion conditions. The UTIAS explosive-driven-implosion facility was used to produce stable, centred and focused hemispherical implosions to generate neutrons from D-D reactions. The simplest and most direct method proved to be in a predetonated stoichiometric mixture of deuterium-oxygen. The other successful method was using a miniature Voitenko compressor, where a plane diaphragm was driven by the implosion wave into a secondary small spherical cavity that contained pure deuterium gas at one atmosphere. | 3 | Nuclear Fusion |
O-GlcNAc is generally a dynamic modification that can be cycled on and off various proteins. Some residues are thought to be constitutively modified by O-GlcNAc. The O-GlcNAc modification is installed by OGT in a sequential bi-bi mechanism where the donor sugar, UDP-GlcNAc, binds to OGT first followed by the substrate protein. The O-GlcNAc modification is removed by OGA in a hydrolysis mechanism involving anchimeric assistance (substrate-assisted catalysis) to yield the unmodified protein and GlcNAc. While crystal structures have been reported for both OGT and OGA, the exact mechanisms by which OGT and OGA recognize substrates have not been completely elucidated. Unlike N-linked glycosylation, for which glycosylation occurs in a specific consensus sequence (Asn-X-Ser/Thr, where X is any amino acid except Pro), no definitive consensus sequence has been identified for O-GlcNAc,. Consequently, predicting sites of O-GlcNAc modification is challenging, and identifying modification sites generally requires mass spectrometry methods. For OGT, studies have shown that substrate recognition is regulated by a number of factors including aspartate and asparagine ladder motifs in the lumen of the superhelical TPR domain, active site residues, and adaptor proteins. As crystal structures have shown that OGT requires its substrate to be in an extended conformation, it has been proposed that OGT has a preference for flexible substrates. In in vitro kinetic experiments measuring OGT and OGA activity on a panel of protein substrates, kinetic parameters for OGT were shown to be variable between various proteins while kinetic parameters for OGA were relatively constant between various proteins. This result suggested that OGT is the "senior partner" in regulating O-GlcNAc and OGA primarily recognizes substrates via the presence of O-GlcNAc rather than the identity of the modified protein. | 6 | Carbohydrates |
Using the addition theorem of tensor operators, the product of a rank n tensor and a rank m tensor can generate a new tensor with rank n+m ~ |n-m|. Therefore, a high rank tensor can be expressed as the product of low rank tensors. This convention is useful to interpret the high rank multipolar exchange terms as a "multi-exchange" process of dipoles (or pseudospins). For example, for the spherical harmonic tensor operators of case, we have
If so, a quadrupole-quadrupole interaction (see next section) can be considered as a two steps dipole-dipole interaction. For example, , so the one step quadrupole transition on site now becomes a two steps of dipole transition . Hence not only inter-site-exchange but also intra-site-exchange terms appear (so called multi-exchange). If is even larger, one can expect more complicated intra-site-exchange terms would appear. However, one has to note that it is not a perturbation expansion but just a mathematical technique. The high rank terms are not necessarily smaller than low rank terms. In many systems, high rank terms are more important than low rank terms. | 7 | Magnetic Ordering |
Cryosurgery (with cryo from the Ancient Greek ) is the use of extreme cold in surgery to destroy abnormal or diseased tissue; thus, it is the surgical application of cryoablation.
Cryosurgery has been historically used to treat a number of diseases and disorders, especially a variety of benign and malignant skin conditions. | 1 | Cryobiology |
Vitrification (, via French ) is the full or partial transformation of a substance into a glass, that is to say, a non-crystalline amorphous solid. Glasses differ from liquids structurally and glasses possess a higher degree of connectivity with the same Hausdorff dimensionality of bonds as crystals: dim = 3. In the production of ceramics, vitrification is responsible for their impermeability to water.
Vitrification is usually achieved by heating materials until they liquidize, then cooling the liquid, often rapidly, so that it passes through the glass transition to form a glassy solid. Certain chemical reactions also result in glasses.
In terms of chemistry, vitrification is characteristic for amorphous materials or disordered systems and occurs when bonding between elementary particles (atoms, molecules, forming blocks) becomes higher than a certain threshold value. Thermal fluctuations break the bonds; therefore, the lower the temperature, the higher the degree of connectivity. Because of that, amorphous materials have a characteristic threshold temperature termed glass transition temperature (T): below T amorphous materials are glassy whereas above T they are molten.
The most common applications are in the making of pottery, glass, and some types of food, but there are many others, such as the vitrification of an antifreeze-like liquid in cryopreservation.
In a different sense of the word, the embedding of material inside a glassy matrix is also called vitrification. An important application is the vitrification of radioactive waste to obtain a substance that is thought to be safer and more stable for disposal.
One study suggests during the eruption of Mount Vesuvius in 79 AD, a victim's brain was vitrified by the extreme heat of the volcanic ash; however, this has been strenuously disputed. | 1 | Cryobiology |
There are specific industrial uses of glow sticks, which are often used as a light source in circumstances where electric lighting and LEDs are not best suited. For example, in the mining industry, glow sticks are required for emergency evacuation in the case of a gas leak. Use of an electric light source in this case may cause an unintended explosion. Chemiluminescence, the type of light used in glow sticks, is a "cold-light" and does not use electricity, and will not cause a gas leak to ignite.
Glow sticks are also used worldwide in the marine industry, often used as fishing lures in long-line, recreational, and commercial fishing, as well as for personnel safety. | 0 | Luminescence |
Strontium aluminate phosphors produce green and aqua hues, where green gives the highest brightness and aqua the longest glow time. Different aluminates can be used as the host matrix. This influences the wavelength of emission of the europium ion, by its covalent interaction with surrounding oxygens, and crystal field splitting of the 5d orbital energy levels.
The excitation wavelengths for strontium aluminate range from 200 to 450 nm, and the emission wavelengths range from 420 to 520 nm. The wavelength for its green formulation is 520 nm, its aqua, or blue-green, version emits at 505 nm, and its blue emits at 490 nm. Strontium aluminate can be formulated to phosphoresce at longer (yellow to red) wavelengths as well, though such emission is often dimmer than that of more common phosphorescence at shorter wavelengths.
For europium-dysprosium doped aluminates, the peak emission wavelengths are 520 nm for , 480 nm for , and 400 nm for .
is important as a persistently luminescent phosphor for industrial applications. It can be produced by molten salt assisted process at 900 °C.
The most described type is the stoichiometric green-emitting (approx. 530 nm) . shows significantly longer afterglow than the europium-only doped material. The Eu dopant shows high afterglow, while Eu has almost none. Polycrystalline is used as a green phosphor for plasma displays, and when doped with praseodymium or neodymium it can act as a good active laser medium. is a phosphor emitting at 305 nm, with quantum efficiency of 70%. Several strontium aluminates can be prepared by the sol-gel process.
The wavelengths produced depend on the internal crystal structure of the material. Slight modifications in the manufacturing process (the type of reducing atmosphere, small variations of stoichiometry of the reagents, addition of carbon or rare-earth halides) can significantly influence the emission wavelengths.
Strontium aluminate phosphor is usually fired at about 1250 °C, though higher temperatures are possible. Subsequent exposure to temperatures above 1090 °C is likely to cause loss of its phosphorescent properties. At higher firing temperatures, the undergoes transformation to .
Cerium and manganese doped strontium aluminate shows intense narrowband (22 nm wide) phosphorescence at 515 nm when excited by ultraviolet radiation (253.7 nm mercury emission line, to lesser degree 365 nm). It can be used as a phosphor in fluorescent lamps in photocopiers and other devices. A small amount of silicon substituting the aluminium can increase emission intensity by about 5%; the preferred composition of the phosphor is .
However, the material has high hardness, causing abrasion to the machinery used in processing it; manufacturers frequently coat the particles with a suitable lubricant when adding them to a plastic. Coating also prevents the phosphor from water degradation over time.
The glow intensity depends on the particle size; generally, the bigger the particles, the better the glow.
Strontium aluminate is insoluble in water and has an approximate pH of 8 (very slightly basic). | 0 | Luminescence |
"Fast ignition" appeared in the late nineties, as part of a push by LLE to build the Omega EP system, which finished in 2008. Fast ignition showed dramatic power savings and moved ICF into the race for energy production. The HiPER experimental facility became dedicated to fast ignition.
In 2001 the United States, China and Republic of Korea joined ITER while Canada withdrew.
In April 2005, a UCLA team announced a way of producing fusion using a machine that "fits on a lab bench", using lithium tantalate to generate enough voltage to fuse deuterium. The process did not generate net power.
The next year, China's EAST test reactor was completed. This was the first tokamak to use superconducting magnets to generate both toroidal and poloidal fields.
In the early 2000s, LANL researchers claimed that an oscillating plasma could reach local thermodynamic equilibrium. This prompted the POPS and Penning trap designs.
In 2005 NIF fired its first bundle of eight beams, achieving the most powerful laser pulse to date - 152.8 kJ (infrared).
MIT researchers became interested in fusors for space propulsion, using fusors with multiple inner cages. Greg Piefer founded Phoenix Nuclear Labs and developed the fusor into a neutron source for medical isotope production. Robert Bussard began speaking openly about the polywell in 2006.
In March 2009, NIF became operational.
In the early 2000s privately backed fusion companies launched to develop commercial fusion power. Tri Alpha Energy, founded in 1998, began by exploring a field-reversed configuration approach. In 2002, Canadian company General Fusion began proof-of-concept experiments based on a hybrid magneto-inertial approach called Magnetized Target Fusion. Investors included Jeff Bezos (General Fusion) and Paul Allen (Tri Alpha Energy). Toward the end of the decade, Tokamak Energy started exploring spherical tokamak devices using reconnection. | 3 | Nuclear Fusion |
In 1951 Ivy Mike, part of Operation Ivy, became the first detonation of a thermonuclear weapon, yielding 10.4 megatons of TNT using liquid deuterium. Cousins and Ware built a toroidal pinch device in England and demonstrated that the plasma in pinch devices is inherently unstable. In 1953 The Soviet Union tested its RDS-6S test, (codenamed "Joe 4" in the US) demonstrated a fission/fusion/fission ("Layercake") design that yielded 600 kilotons. Igor Kurchatov spoke at Harwell on pinch devices, revealing that the USSR was working on fusion.
Seeking to generate electricity, Japan, France and Sweden all start fusion research programs
In 1955, John D. Lawson (scientist) creates what is now known as the Lawson criterion which is a criterion for a fusion reactor to produce more energy than is lost to the environment due to problems like Bremsstrahlung radiation.
In 1956 the Soviet Union began publishing articles on plasma physics, leading the US and UK to follow over the next several years.
The Sceptre III z-pinch plasma column remained stable for 300 to 400 microseconds, a dramatic improvement on previous efforts. The team calculated that the plasma had an electrical resistivity around 100 times that of copper, and was able to carry 200 kA of current for 500 microseconds. | 3 | Nuclear Fusion |
Subject to any regulations restricting who can obtain donor sperm, donor sperm is available to all people who, for whatever reason, wish to have a child. These regulations vary significantly across jurisdictions, and some countries do not have any regulations. When an individual finds that they are barred from receiving donor sperm within their jurisdiction, they may travel to another jurisdiction to obtain sperm. Regulations change from time to time. In most jurisdictions, donor sperm is available to an individual if their partner is infertile or where they have a genetic disorder. However, the categories of individuals who may obtain donor sperm is expanding, with its availability to single persons and to same-sex couples becoming more common, and some sperm banks supply fertility centers which specialize in the treatment of such people.
Frozen vials of donor sperm may be shipped by the sperm bank to a recipient's home for self-insemination, or they may be shipped to a fertility clinic or physician for use in fertility treatments. The sperm bank will rely on the recipient woman or medical practitioner to report the outcome of any use of the sperm to the sperm bank. This enables a sperm bank to adhere to any national limits of pregnancy numbers. The sperm bank may also impose its own worldwide limit on numbers.
Sperm is introduced into the recipient by means of artificial insemination or by IVF. The most common technique is conventional artificial insemination which consists of a catheter to put the sperm into the vagina where it is deposited at the entrance to the cervix. In biological terms, this is much the same process as when semen is ejaculated from the penis during sexual intercourse. Owing to its simplicity, this method of insemination is commonly used for home and self inseminations principally by single women and lesbians. Other types of uses include intrauterine insemination (IUI) and deep intrauterine artificial insemination where washed sperm must be used. These methods of insemination are most commonly used in fertility centers and clinics mainly because they produce better pregnancy rates than ICI insemination especially where the woman has no underlying fertility issues.
Men may also store their own sperm at a sperm bank for future use particularly where they anticipate traveling to a war zone or having to undergo chemotherapy which might damage the testes.
Sperm from a sperm donor may also be used in surrogacy arrangements and for creating embryos for embryo donation. Donor sperm may be supplied by the sperm bank directly to the recipient to enable a woman to perform her own artificial insemination which can be carried out using a needleless syringe or a cervical cap conception device. The cervical cap conception device allows the donor semen to be held in place close to the cervix for between six and eight hours to allow fertilization to take place. Alternatively, donor sperm can be supplied by a sperm bank through a registered medical practitioner who will perform an appropriate method of insemination or IVF treatment using the donor sperm in order for the woman to become pregnant. | 1 | Cryobiology |
Stripping works on the basis of mass transfer. The idea is to make the conditions favorable for the component, A, in the liquid phase to transfer to the vapor phase. This involves a gas–liquid interface that A must cross. The total amount of A that has moved across this boundary can be defined as the flux of A, N. | 5 | Separation Processes |
This method is the same as the above but where two (or more) solvents are used. This relies on both "compound A" and "impurity B" being soluble in a first solvent. A second solvent is slowly added. Either "compound A" or "impurity B" will be insoluble in this solvent and precipitate, whilst the other of "compound A"/"impurity B" will remain in solution. Thus the proportion of first and second solvents is critical. Typically the second solvent is added slowly until one of the compounds begins to crystallize from the solution and then the solution is cooled. Heating is not required for this technique but can be used.
The reverse of this method can be used where a mixture of solvents dissolves both A and B. One of the solvents is then removed by distillation or by an applied vacuum. This results in a change in the proportions of the solvent causing either "compound A" or "impurity B" to precipitate. | 5 | Separation Processes |
Galactogen is a polysaccharide of galactose that functions as energy storage in pulmonate snails and some Caenogastropoda. This polysaccharide is exclusive of the reproduction and is only found in the albumen gland from the female snail reproductive system and in the perivitelline fluid of eggs.
Galactogen serves as an energy reserve for developing embryos and hatchlings, which is later replaced by glycogen in juveniles and adults. The advantage of accumulating galactogen instead of glycogen in eggs remains unclear, although some hypotheses have been proposed (see below). | 6 | Carbohydrates |
The Weermann degradation could be executed with α-hydroxy-substituted carbonic acid amides. For example, sugar. | 6 | Carbohydrates |
Mini-bulk tests are conducted with 1-100t of samples on industrial scale sensor-based ore sorters. The size fraction intervals to be treated are prepared using screen classifications. Full capacity is established then with each fraction and multiple cut-points are programmed in the sorting software. After creating multiple sorting fractions in rougher, scavenger and cleaner steps these weighed are sent for assays. The resulting data delivers all input for flow-sheet development. Since the tests are conducted on industrial scale equipment, there is no scale-up factor involved when designing a flow-sheet and installation of sensor-based ore sorting. | 5 | Separation Processes |
The intention of the attacker is often to cause shame and pain rather than to kill the victim. In Britain, such attacks, particularly those against men, are believed to be underreported, and as a result many of them do not show up in official statistics. Some of the most common motivations of perpetrators include:
* Personal conflict regarding intimate relationships and sexual rejection
* Sexual-related jealousy and lust
* Revenge for refusal of sexual advances, proposals of marriage, and demands for dowry
* Gang violence and rivalry
* Conflicts over land ownership, farm animals, housing, and property
Acid attacks often occur as revenge against a woman who rejects a proposal of marriage or a sexual advance. Gender inequality and women's position in the society, in relation to men, plays a significant role in these types of attacks.
Attacks against individuals based on their religious beliefs or social or political activities also occur. These attacks may be targeted against a specific individual, due to their activities, or may be perpetrated against random persons merely because they are part of a social group or community. In Europe, Konstantina Kouneva, a former member of the European Parliament, had acid thrown on her in 2008, in what was described as "the most severe assault on a trade unionist in Greece for 50 years." Female students have had acid thrown in their faces as a punishment for attending school. Acid attacks due to religious conflicts have been also reported. Both males and females have been victims of acid attacks for refusing to convert to another religion.
Conflicts regarding property issues, land disputes, and inheritance have also been reported as motivations of acid attacks. Acid attacks related to conflicts between criminal gangs occur in many places, including the UK, Greece, and Indonesia. | 4 | Acids + Bases |
The medical effects of acid attacks are extensive. As a majority of acid attacks are aimed at the face, several articles thoroughly reviewed the medical implications for these victims. The severity of the damage depends on the concentration of the acid and the time before the acid is thoroughly washed off with water or neutralized with a neutralizing agent. The acid can rapidly eat away skin, the layer of fat beneath the skin, and in some cases even the underlying bone. Eyelids and lips may be completely destroyed and the nose and ears severely damaged. Though not exhaustive, Acid Survivors Foundation Uganda findings included:
* The skull is partly destroyed/deformed and hair lost.
* Ear cartilage is usually partly or totally destroyed; deafness may occur.
* Eyelids may be burned off or deformed, leaving the eyes extremely dry and prone to blindness. Acid directly in the eye also damages sight, sometimes causing blindness in both eyes.
* The nose can become shrunken and deformed; the nostrils may close off completely due to destroyed cartilage.
* The mouth becomes shrunken and narrow, and it may lose its full range of motion. Sometimes, the lips may be partly or totally destroyed, exposing the teeth. Eating and speaking can become difficult.
* Scars can run down from the chin to neck area, shrinking the chin and extremely limiting range of motion in the neck.
* Inhalation of acid vapors usually creates respiratory problems, exacerbated restricted airway pathways (the esophagus and nostrils) in acid patients.
In addition to these above-mentioned medical effects, acid attack victims face the possibility of sepsis, kidney failure, skin depigmentation, and even death.
A 2015 attack that involved throwing sulfuric acid on a man's face and body while he lay in bed caused him, among other serious injuries, to become paralyzed from the neck down. | 4 | Acids + Bases |
In the case of oxide copper ore, a heap leaching pad will dissolve a dilute copper sulfate solution in a weak sulfuric acid solution. This pregnant leach solution (PLS) is pumped to an extraction mixer settler where it is mixed with the organic phase (a kerosene hosted extractant). The copper transfers to the organic phase, and the aqueous phase (now called raffinate) is pumped back to the heap to recover more copper.
In a high-chloride environment typical of Chilean copper mines, a wash stage will rinse any residual pregnant solution entrained in the organic with clean water.
The copper is then stripped from organic phase in the strip stage into a strong sulfuric acid solution suitable for electrowinning. This strong acid solution is called barren electrolyte when it enters the cell, and strong electrolyte when it is copper bearing after reacting in the cell. | 5 | Separation Processes |
In aqueous solution it is a weak acid, having a pK of 3.7:
Isocyanic acid hydrolyses to carbon dioxide and ammonia:
Dilute solutions of isocyanic acid are stable in inert solvents, e.g. ether and chlorinated hydrocarbons.
At high concentrations, isocyanic acid oligomerizes to give the trimer cyanuric acid and cyamelide, a polymer. These species usually are easily separated from liquid- or gas-phase reaction products.
Isocyanic acid reacts with amines to give ureas (carbamides):
This reaction is called carbamylation.
HNCO adds across electron-rich double bonds, such as vinylethers, to give the corresponding isocyanates.
Isocyanic acid, HNCO, is a Lewis acid whose free energy, enthalpy and entropy changes for its 1:1 association with a number of bases in carbon tetrachloride solution at 25 °C have been reported. The acceptor properties of HNCO are compared with other Lewis acid in the ECW model.
Low-temperature photolysis of solids containing HNCO creates the tautomer cyanic acid , also called hydrogen cyanate. Pure cyanic acid has not been isolated, and isocyanic acid is the predominant form in all solvents. Sometimes information presented for cyanic acid in reference books is actually for isocyanic acid. | 4 | Acids + Bases |
The oldest form of mineral processing practiced since the Stone Age is hand-picking. Georgius Agricola also describes hand-picking is his book De re metallica in 1556. Sensor-based sorting is the automation and extension to hand picking. In addition to sensors that measure visible differences like color (and the further interpretation of the data regarding texture and shape), other sensors are available on industrial scale sorters that are able to measure differences invisible for the human eye (EM, XRT, NIR).
The principles of the technology and the first machinery has been developed since the 1920s (. Nevertheless, widely applied and standard technology it is only in the industrial minerals and gemstone segments. Mining is benefiting from the step change developments in sensing and computing technologies and from machine development in the recycling and food processing industries.
In 2002, Cutmore and Eberhard stated that the relatively small installed base of sensor-based sorters in mining is more a result of insufficient industry interest than any technical barriers to their effective use
Nowadays sensor-based sorting is beginning to reveal its potential in various applications in basically all segments of mineral production (industrial minerals, gemstones, base-metals, precious metals, ferrous metals, fuel). Precondition is physical liberation in coarse size ranges (~) to make physical separation possible. Either the product fraction, but more often the waste fraction needs to be liberated. If liberation is present, there is good potential that one of available detection technologies on today's sensor-based sorters can positively or negatively identify one of the two desired fractions. | 5 | Separation Processes |
Ultraviolet absorbers are molecules used in organic materials (polymers, paints, etc.) to absorb UV radiation to reduce the UV degradation (photo-oxidation) of a material. The absorbers can themselves degrade over time, so monitoring of absorber levels in weathered materials is necessary.
In sunscreen, ingredients that absorb UVA/UVB rays, such as avobenzone, oxybenzone and octyl methoxycinnamate, are organic chemical absorbers or "blockers". They are contrasted with inorganic absorbers/"blockers" of UV radiation such as carbon black, titanium dioxide, and zinc oxide.
For clothing, the ultraviolet protection factor (UPF) represents the ratio of sunburn-causing UV without and with the protection of the fabric, similar to sun protection factor (SPF) ratings for sunscreen. Standard summer fabrics have UPFs around 6, which means that about 20% of UV will pass through.
Suspended nanoparticles in stained-glass prevent UV rays from causing chemical reactions that change image colors. A set of stained-glass color-reference chips is planned to be used to calibrate the color cameras for the 2019 ESA Mars rover mission, since they will remain unfaded by the high level of UV present at the surface of Mars.
Common soda–lime glass, such as window glass, is partially transparent to UVA, but is opaque to shorter wavelengths, passing about 90% of the light above 350 nm, but blocking over 90% of the light below 300 nm. A study found that car windows allow 3–4% of ambient UV to pass through, especially if the UV was greater than 380 nm. Other types of car windows can reduce transmission of UV that is greater than 335 nm. Fused quartz, depending on quality, can be transparent even to vacuum UV wavelengths. Crystalline quartz and some crystals such as CaF and MgF transmit well down to 150 nm or 160 nm wavelengths.
Wood's glass is a deep violet-blue barium-sodium silicate glass with about 9% nickel oxide developed during World War I to block visible light for covert communications. It allows both infrared daylight and ultraviolet night-time communications by being transparent between 320 nm and 400 nm and also the longer infrared and just-barely-visible red wavelengths. Its maximum UV transmission is at 365 nm, one of the wavelengths of mercury lamps. | 8 | Ultraviolet Radiation |
Direct experimental evidence of altermagnetic band structure in semiconducting MnTe and metallic RuO was first published in 2024. Many more materials are predicted to be altermagnets – ranging from insulators, semiconductors, and metals to superconductors. Altermagnetism was predicted in 3d and 2d materials with both light as well as heavy elements and can be found in nonrelativistic as well as relativistic band structures. | 7 | Magnetic Ordering |
In 1933 Vincenzo Bisceglie made the first attempt to encapsulate cells in polymer membranes. He demonstrated that tumor cells in a polymer structure transplanted into pig abdominal cavity remained viable for a long period without being rejected by the immune system.
Thirty years later in 1964, the idea of encapsulating cells within ultra thin polymer membrane microcapsules so as to provide immunoprotection to the cells was then proposed by Thomas Chang who introduced the term "artificial cells" to define this concept of bioencapsulation. He suggested that these artificial cells produced by a drop method not only protected the encapsulated cells from immunorejection but also provided a high surface-to-volume relationship enabling good mass transfer of oxygen and nutrients.
Twenty years later, this approach was successfully put into practice in small animal models when alginate-polylysine-alginate (APA) microcapsules immobilizing xenograft islet cells were developed. The study demonstrated that when these microencapsulated islets were implanted into diabetic rats, the cells remained viable and controlled glucose levels for several weeks.
Human trials utilising encapsulated cells were performed in 1998. Encapsulated cells expressing a cytochrome P450 enzyme to locally activate an anti-tumour prodrug were used in a trial for advanced, non-resectable pancreatic cancer. Approximately a doubling of survival time compared to historic controls was demonstrated. | 2 | Tissue Engineering |
Photosensitizers are dye compounds that absorb the photons from incoming light and eject electrons, producing an electric current that can be used to power a device or a storage unit. According to a new study performed by Michael Grätzel and fellow scientist Anders Hagfeldt, advances in photosensitizers have resulted in a substantial improvement in performance of DSSC’s under solar and ambient light conditions. Another key factor to achieve power-conversion records is cosensitization, due to its ability combine dyes that can absorb light across a wider range of the light spectrum. Cosensitization is a chemical manufacturing method that produces DSSC electrodes containing two or more different dyes with complementary optical absorption capabilities, enabling the use of all available sunlight.
The researchers from Switzerland’s École polytechnique fédérale de Lausanne (EPFL) found that the efficiency to cosensitized solar cells can be raised by the pre-adsorption of a monolayer of hydroxamic acid derivative on a surface of nanocrystalline mesoporous titanium dioxide, which functions as the electron transport mechanism of the electrode. The two photosensitizer molecules used in the study were the organic dye SL9, which served as the primary long wavelength-light harvester, and the dye SL10, which provided an additional absorption peak that compensates the SL9’s inefficient blue light harvesting. It was found that adding this hydroxamic acid layer improved the dye layer’s molecular packing and ordering. This slowed down the adsorption of the sensitizers and augmented their fluorescence quantum yield, improving the power conversion efficiency of the cell.
The DSSC developed by the team showed a record-breaking power conversion efficiency of 15.2% under standard global simulated sunlight and long-term operational stability over 500 hours. In addition, devices with a larger active area exhibited efficiencies of around 30% while maintaining high stability, offering new possibilities for the DSSC field. | 8 | Ultraviolet Radiation |
Organisms ranging from bacteria, yeast, fungi, insects, invertebrates, and lower and higher plants have enzymes that can make trehalose.
In nature, trehalose can be found in plants, and microorganisms. In animals, trehalose is prevalent in shrimp, and also in insects, including grasshoppers, locusts, butterflies, and bees, in which trehalose serves as blood-sugar. Trehalase genes are found in tardigrades, the microscopic ecdysozoans found worldwide in diverse extreme environments.
Trehalose is the major carbohydrate energy storage molecule used by insects for flight. One possible reason for this is that the glycosidic linkage of trehalose, when acted upon by an insect trehalase, releases two molecules of glucose, which is required for the rapid energy requirements of flight. This is double the efficiency of glucose release from the storage polymer starch, for which cleavage of one glycosidic linkage releases only one glucose molecule.
In plants, trehalose is seen in sunflower seeds, moonwort, Selaginella plants, and sea algae. Within the fungi, it is prevalent in some mushrooms, such as shiitake (Lentinula edodes), oyster, king oyster, and golden needle.
Even within the plant kingdom, Selaginella (sometimes called the resurrection plant), which grows in desert and mountainous areas, may be cracked and dried out, but will turn green again and revive after rain because of the function of trehalose.
The two prevalent theories as to how trehalose works within the organism in the state of cryptobiosis are the vitrification theory, a state that prevents ice formation, or the water displacement theory, whereby water is replaced by trehalose.
In bacterial cell wall, trehalose has a structural role in adaptive responses to stress such as osmotic differences and extreme temperature. Yeast uses trehalose as a carbon source in response to abiotic stresses. In humans, the only known function of trehalose is its ability to activate autophagy inducer.
Trehalose has also been reported for anti-bacterial, anti-biofilm, and anti-inflammatory (in vitro and in vivo) activities, upon its esterification with fatty acids of varying chain lengths. | 6 | Carbohydrates |
When clearing gases, an often used and mostly working method for clearing large particles is to blow it into a large chamber where the gas's velocity decreases and the solid particles start sinking to the bottom. This method is used mostly because of its cheap cost. | 5 | Separation Processes |
Hubel was elected as an ASME Fellow in 2008, and a Fellow of the American Institute for Medical and Biological Engineering in 2012. She was named a Cryofellow of the Society for Cryobiology in 2021. | 1 | Cryobiology |
Many risks and challenges must still be addressed and explored before tissue engineered heart valves can fully be clinically implemented:
* Contamination – Particular source materials can foster a microbiological environment that is conducive to the susceptibility of viruses and infectious diseases. Anytime an external scaffold is implanted within the human body, contamination, while inevitable, can be diminished through the enforcement of sterile technique.
* Scaffold Interactions - There are many risks associated with the interactions between cells and the implanted scaffold as specific biocompatibility requirements are still largely unknown with current research. The response to these interactions are also highly individualistic, dependent on the specific patient's biological environment; therefore, animal models researched prior may not accurately portray outcomes in the human body. Due to the highly interactive nature between the scaffold and surrounding tissue, properties such as biodegradability, biocompatibility, and immunogenicity must all be carefully considered as they are key factors in the performance of the final product.
* Structural complexity – Heart valves with their heterogeneous structure are very complex and dynamic, thus posing a challenge for tissue engineered valves to mimic. The new valves must have high durability while also meeting the anatomical shape and mechanical functions of the native valve. | 2 | Tissue Engineering |
Flow rate of the liquid phase and molar fractions of the desired compound in it are and .
Flow rate of the vapour phase and molar fractions of the desired compound in it are and . | 5 | Separation Processes |
As mentioned above, the CCE separates cells based on their sedimentation property but not specific features (e.g. surface protein, cell shape). It cannot separate different types of cells which have similar sedimentation properties. This means that previous purification needs to be done for mixed cell type sample. The CCE is also limited to cells which are able to be individually suspended in the buffer solution. Cells which always attach to something cannot be separated by the CCE. | 5 | Separation Processes |
Another type of innovative neutron generator is the inertial electrostatic confinement fusion device. This neutron generator avoids using a solid target which will be sputter eroded causing metalization of insulating surfaces. Depletion of the reactant gas within the solid target is also avoided. Far greater operational lifetime is achieved. Originally called a fusor, it was invented by Philo Farnsworth, the inventor of electronic television. | 3 | Nuclear Fusion |
OFM comprises more than 24 collagens (most notably types I and III), but also contains many growth factors, polysaccharides and proteoglycans that naturally exist as part of the extracellular matrix and play important roles in wound healing and soft tissue repair. The composition includes more than 150 different proteins, including elastin, fibronectin, glycosaminoglycans, basement membrane components, and various growth factors, such as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF) and platelet derived growth factor (PDGF). OFM has been shown to recruit mesenchymal stem cells, stimulate cell proliferation, angiogenesis and vascularogenesis, and modulate matrix metalloproteinase and neutrophil elastase. The porous structure of OFM has been characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atomic force microscopy (AFM), histology, Sirius Red staining, small-angle x-ray scattering (SAXS), and micro computerized topography (MicroCT). OFM has been shown to contain residual vascular channels that facilitate blood vessel formation through angioconduction. | 2 | Tissue Engineering |
Phosphorescent materials were discovered in the 1700s, and people have been studying them and making improvements over the centuries. The development of strontium aluminate pigments in 1993 was spurred on by the need to find a substitute for glow-in-the-dark materials with high luminance and long phosphorescence, especially those that used promethium. This led to the discovery by Yasumitsu Aoki (Nemoto & Co.) of materials with luminance approximately 10 times greater than zinc sulfide and phosphorescence approximately 10 times longer, and 10 times more expensive. The invention was patented by Nemoto & Co., Ltd. and licensed to other manufacturers and watch brands. Strontium aluminates are now the longest lasting and brightest phosphorescent material commercially available.
For many phosphorescence-based purposes, strontium aluminate is a superior phosphor to its predecessor, copper-activated zinc sulfide, being about 10 times brighter and 10 times longer glowing. It is frequently used in glow in the dark objects, where it replaces the cheaper but less efficient Cu:ZnS that many people recognize with nostalgia – this is what made glow in the dark stars stickers glow.
Advancements in understanding of phosphorescent mechanisms, as well as advancements in molecular imaging, have enabled the development of novel, state-of-the-art strontium aluminates. | 0 | Luminescence |
Cryoimmunotherapy, also referred to as cryoimmunology, is an oncological treatment for various cancers that combines cryoablation of tumor with immunotherapy treatment. In-vivo cryoablation of a tumor, alone, can induce an immunostimulatory, systemic anti-tumor response, resulting in a cancer vaccine—the abscopal effect. Thus, cryoablation of tumors is a way of achieving autologous, in-vivo tumor lysate vaccine and treat metastatic disease. However, cryoablation alone may produce an insufficient immune response, depending on various factors, such as high freeze rate. Combining cryotherapy with immunotherapy enhances the immunostimulating response and has synergistic effects for cancer treatment.
Although, cryoblation and immunotherapy has been used successfully in oncological clinical practice for over 100 years, and can treat metastatic disease with curative intent, it has been ignored in modern practice. Only recently has cryoimmunotherapy been resurrected to become the gold standard in cancer treatment of all stages of disease. | 1 | Cryobiology |
UV pinning is the process of applying a dose of low intensity ultraviolet (UV) light to a UV curable ink (UV ink). The lights wavelengths must be correctly matched to the inks photochemical properties. As a result, the ink droplets move to a higher viscosity state, but stop short of full cure. This is also referred to as the "gelling" of the ink.
UV pinning is typically used in UV ink jet applications (e.g. the printing of labels, the printing of electronics, and the fabrication of 3-D microstructures). | 8 | Ultraviolet Radiation |
Generally, the main process in a rotary vacuum drum filter is continuous filtration whereby solids are separated from liquids through a filter medium by a vacuum. The filter cloth is one of the most important components on a filter and is typically made of weaving polymer yarns. The best selection of cloth can increase the performance of filtration. Initially, slurry is pumped into the trough and as the drum rotates, it is partially submerged in the slurry. The vacuum draws liquid and air through the filter media and out the shaft hence forming a layer of cake. An agitator is used to regulate the slurry if the texture is coarse and it is settling rapidly. Solids that are trapped on the surface of the drum are washed and dried after 2/3 of revolution, removing all the free moisture.
During the washing stage, the wash liquid can either be poured onto the drum or sprayed on the cake. Cake pressing is optional but its advantages are preventing cake cracking and removing more moisture. Cake discharge is when all the solids are removed from the surface of the cake by a scraper blade, leaving a clean surface as drum re-enters the slurry. There are a few types of discharge which are scraper, roller, string, endless belt and pre coat. The filtrate and air flow through internal pipes, valve and into the vacuum receiver where the separation of liquid and gas occurs producing a clear filtrate. Pre coat filtration is an ideal method to produce a high clarity of filtrate. Basically, the drum surface is pre coated with a filter aid such as diatomaceous earth (DE) or perlite to improve filtration and increase cake permeability. It then undergoes the same process cycle as the conventional rotary vacuum drum filter however, pre coat filtration uses a higher precision blade to scrape off the cake.
The filter is assessed by the size of the drum or filter area and its possible output. Typically, the output is in the units of pounds per hour of dry solids per square foot of filter area. The size of the auxiliary parts depends on the area of the filter and the type of usage. Rotary vacuum filters are flexible in handling variety of materials therefore the estimated solids yield from 5 to 200 pounds per hour per square foot. For pre coat discharge, the solid output is approximately 2 to 40 gallons per hour per square foot. Filtration efficiencies can also be improved in terms dryness of filter cake by significantly preventing filtrate liquid from getting stuck in the filter drum during filtration phase. Usage of multiple filters for example, running 3 filter units instead of 2 units yields a thicker cake hence, producing a clearer filtrate. This becomes beneficial in terms of production cost and also quality. | 5 | Separation Processes |
In organic carboxylic acids, an electronegative substituent can pull electron density out of an acidic bond through the inductive effect, resulting in a smaller value. The effect decreases, the further the electronegative element is from the carboxylate group, as illustrated by the following series of halogenated butanoic acids. | 4 | Acids + Bases |
When stored as a powder at 4 °C or below, IPTG is stable for 5 years. It is significantly less stable in solution; Sigma recommends storage for no more than a month at room temperature. IPTG is an effective inducer of protein expression in the concentration range of 100 μmol/L to 3.0 mmol/L. , a mutant that over-produces the lac repressor, is present, then a higher concentration of IPTG may be necessary.
In blue-white screen, IPTG is used together with X-gal. Blue-white screen allows colonies that have been transformed with the recombinant plasmid rather than a non-recombinant one to be identified in cloning experiments. | 6 | Carbohydrates |
Isocyanic acid is a chemical compound with the structural formula HNCO, which is often written as . It is a colourless, volatile and poisonous substance, with a boiling point of 23.5 °C. It is the predominant tautomer and an isomer of cyanic acid (aka. cyanol) ().
The derived anion of isocyanic acid is the same as the derived anion of cyanic acid, and that anion is , which is called cyanate. The related functional group is isocyanate; it is distinct from cyanate (), fulminate (), and nitrile oxide ().
Isocyanic acid was discovered in 1830 by Justus von Liebig and Friedrich Wöhler.
Isocyanic acid is the simplest stable chemical compound that contains carbon, hydrogen, nitrogen, and oxygen, the four most commonly found elements in organic chemistry and biology. It is the only fairly stable one of the four linear isomers with molecular formula HOCN that have been synthesized, the others being cyanic acid (cyanol, ) and the elusive fulminic acid () and isofulminic acid . | 4 | Acids + Bases |
Cryoneurolysis is performed with a cryoprobe, which is composed of a hollow cannula that contains a smaller inner lumen. The pressurized coolant (nitrous oxide, carbon dioxide or liquid nitrogen) travels down the lumen and expands at the end of the lumen into the tip of the hollow cannula. No coolant exits the cryoprobe. The expansion of the pressurized liquid causes the surrounding area to cool (known as the Joule–Thomson effect) and the phase change of the liquid to gas also causes the surrounding area to cool. This causes a visible iceball to form and the tissue surrounding the end of the cryoprobe to freeze. The gas form of the coolant then travels up the length of the cryoprobe and is safely expelled. The tissue surrounding the end of the cryoprobe can reach as low as −88.5 °C with nitrous oxide as the coolant, and as low as −195.8 °C with liquid nitrogen. Temperatures below −100 °C are damaging to nerves.
Cryo-S Painless cryoanalgesia device is the next generation of apparatus used by many experts in the field since 1992. The working medium for Cryo-S Painless is carbon dioxide: (−78 °C) or nitrous oxide: (−89 °C), very efficient and easy to use gases. Cryo-S Painless is controlled by a microprocessor and all the parameters are displayed and monitored on a LCD screen. Mode selection probe, cleaning and freezing can be performed automatically using footswitch or touch screen which allows to keep the site of a procedure under sterile conditions. Electronic communication (chip system) between the connected probe and device allows recognition of optimal operating parameters and auto-configures to cryoprobe characteristics. Pressure and gas flow are set automatically, any manual adjustment is not necessary. Cryoprobe temperature, cylinder pressure, gas flow inside of cryoprobe and procedure time are displayed during freezing. Built-in voice communication Built-in neurostimulation (sensory, motor). | 1 | Cryobiology |
Directed differentiation is a bioengineering methodology at the interface of stem cell biology, developmental biology and tissue engineering. It is essentially harnessing the potential of stem cells by constraining their differentiation in vitro toward a specific cell type or tissue of interest. Stem cells are by definition pluripotent, able to differentiate into several cell types such as neurons, cardiomyocytes, hepatocytes, etc. Efficient directed differentiation requires a detailed understanding of the lineage and cell fate decision, often provided by developmental biology. | 2 | Tissue Engineering |
An anode ray (also positive ray or canal ray) is a beam of positive ions that is created by certain types of gas-discharge tubes. They were first observed in Crookes tubes during experiments by the German scientist Eugen Goldstein, in 1886. Later work on anode rays by Wilhelm Wien and J. J. Thomson led to the development of mass spectrometry. | 0 | Luminescence |