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Mono-methyl Hydrazine
Monomethylhydrazine (MMH) is a highly toxic, volatile hydrazine derivative with the chemical formula . It is used as a rocket propellant in bipropellant rocket engines because it is hypergolic with various oxidizers such as nitrogen tetroxide () and nitric acid (). As a propellant, it is described in specification MIL-PRF-27404. MMH is a hydrazine derivative that was once used in the orbital maneuvering system (OMS) and reaction control system (RCS) engines of NASA's Space Shuttle, which used MMH and MON-3 (a mixture of nitrogen tetroxide with approximately 3% nitric oxide). This chemical is toxic and carcinogenic, but it is easily stored in orbit, providing moderate performance for very low fuel tank system weight. MMH and its chemical relative unsymmetrical dimethylhydrazine (UDMH) have a key advantage that they are stable enough to be used in regeneratively cooled rocket engines. The European Space Agency (ESA) has attempted to seek new options in terms of bipropellant rocket c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methylamine
Methylamine, also known as methanamine, is an organic compound with a formula of . This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine. Methylamine is sold as a solution in methanol, ethanol, tetrahydrofuran, or water, or as the anhydrous gas in pressurized metal containers. Industrially, methylamine is transported in its anhydrous form in pressurized railcars and tank trailers. It has a strong odor similar to rotten fish. Methylamine is used as a building block for the synthesis of numerous other commercially available compounds. Industrial production Methylamine has been produced industrially since the 1920s (originally by Commercial Solvents Corporation for dehairing of animal skins). This was made possible by and his wife Eugenia who discovered amination of alcohols, including methanol, on alumina or kaolin catalyst after WWI, filed two patent applications in 1919 and published an a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unsymmetrical Dimethylhydrazine
Unsymmetrical dimethylhydrazine (abbreviated as UDMH; also known as 1,1-dimethylhydrazine, heptyl or Geptil) is a chemical compound with the formula H2NN(CH3)2 that is primarily used as a rocket propellant. At room temperature, UDMH is a colorless liquid, with a sharp, fishy, ammonia-like smell typical of organic amines. Samples turn yellowish on exposure to air and absorb oxygen and carbon dioxide. It is miscible with water, ethanol, and kerosene. At concentrations between 2.5% and 95% in air, its vapors are flammable. It is not sensitive to shock. Symmetrical dimethylhydrazine (1,2-dimethylhydrazine) also exists, but it is not as useful. UDMH can be oxidized in air to form many different substances, including toxic ones. Synthesis In 1875, UDMH was first prepared by Emil Fischer, who discovered and named the class of hydrazines, by reducing N-Nitrosodimethylamine with zinc in boiling acetic acid. Fischer's student Edward Renouf later studied UDMH more extensively as part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycotoxins
A mycotoxin (from the Greek μύκης , "fungus" and τοξικός , "poisonous") is a toxic secondary metabolite produced by fungi and is capable of causing disease and death in both humans and other animals. The term 'mycotoxin' is usually reserved for the toxic chemical products produced by fungi that readily colonize crops. Examples of mycotoxins causing human and animal illness include aflatoxin, citrinin, fumonisins, ochratoxin A, patulin, trichothecenes, zearalenone, and ergot alkaloids such as ergotamine. One mold species may produce many different mycotoxins, and several species may produce the same mycotoxin. Production Most fungi are aerobic (use oxygen) and are found almost everywhere in extremely small quantities due to the diminutive size of their spores. They consume organic matter wherever humidity and temperature are sufficient. Where conditions are right, fungi proliferate into colonies and mycotoxin levels become high. The reason for the produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocket Fuels
Rocket propellant is used as reaction mass ejected from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical rocket, or from an external source, as with ion engines. Overview Rockets create thrust by expelling mass rear-ward, at high velocity. The thrust produced can be calculated by multiplying the mass flow rate of the propellants by their exhaust velocity relative to the rocket (specific impulse). A rocket can be thought of as being accelerated by the pressure of the combusting gases against the combustion chamber and Rocket engine nozzle, nozzle, not by "pushing" against the air behind or below it. Rocket engines perform best in outer space because of the lack of air pressure on the outside of the engine. In space it is also possible to fit a longer nozzle without suffering from flow separation. Most chemical propellants release energy through redox chemistry, more specifically combustion. As such, both an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temozolomide
Temozolomide, sold under the brand name Temodar among others, is an anticancer medication used to treat brain tumors such as glioblastoma and anaplastic astrocytoma. Text was copied from this source which is copyright European Medicines Agency. Reproduction is authorized provided the source is acknowledged. It is taken by mouth or via intravenous infusion. The most common side effects with temozolomide are nausea, vomiting, constipation, loss of appetite, alopecia (hair loss), headache, fatigue, convulsions (seizures), rash, neutropenia or lymphopenia (low white-blood-cell counts), and thrombocytopenia (low blood platelet counts). People receiving the solution for infusion may also have injection-site reactions, such as pain, irritation, itching, warmth, swelling and redness, as well as bruising. Temozolomide is an alkylating agent used to treat serious brain cancers; most commonly as second-line treatments for astrocytoma and as the first-line treatment for glioblastoma. Ola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suritozole
Suritozole (MDL 26,479) is an investigational cognition enhancer. It acts as a partial inverse agonist at the benzodiazepine receptor site on the GABAA ion channel complex, but does not have either anxiogenic or convulsant effects, unlike other BZD inverse agonists such as DMCM. It was investigated for the treatment of depression and Alzheimer's disease Alzheimer's disease (AD) is a neurodegenerative disease and the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems wit ... in the 90s, but clinical development seems to have been discontinued. Synthesis The reaction between monomethylhydrazine 0-34-4(1) and methyl isothiocyanate (Trapex) 56-61-6(2) gave 2,4-dimethylthiosemicarbazide 621-75-6(3). Amide formation with 3-fluorobenzoyl chloride 711-07-5(4) yielded 1-(3-fluorobenzoyl)-2,4-dimethylthiosemicarbazide 10623-52-4(5). Cyclization to Sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centers For Disease Control And Prevention
The Centers for Disease Control and Prevention (CDC) is the National public health institutes, national public health agency of the United States. It is a Federal agencies of the United States, United States federal agency under the United States Department of Health and Human Services, Department of Health and Human Services (HHS), and is headquartered in Atlanta, Georgia. The CDC's current nominee for director is Susan Monarez. She became acting director on January 23, 2025, but stepped down on March 24, 2025 when nominated for the director position. On May 14, 2025, Robert F. Kennedy Jr. stated that lawyer Matthew Buzzelli is acting CDC director. However, the CDC web site does not state the acting director's name. The agency's main goal is the protection of public health and safety through the control and prevention of disease, injury, and disability in the US and worldwide. The CDC focuses national attention on developing and applying disease control and prevention. It e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyromitrin
Gyromitrin is a toxin and carcinogen present in several members of the fungal genus '' Gyromitra'', like '' G. esculenta''. Its formula is . It is unstable and is easily hydrolyzed to the toxic compound monomethylhydrazine . Monomethylhydrazine acts on the central nervous system and interferes with the normal use and function of vitamin B6. Poisoning results in nausea, stomach cramps, and diarrhea, while severe poisoning can result in convulsions, jaundice, or even coma or death. Exposure to monomethylhydrazine has been shown to be carcinogenic in small mammals. History Poisonings related to consumption of the false morel ''Gyromitra esculenta'', a highly regarded fungus eaten mainly in Finland and by some in parts of Europe and North America, had been reported for at least a hundred years. Experts speculated the reaction was more of an allergic one specific to the consumer, or a misidentification, rather than innate toxicity of the fungus, due to the wide range in effects s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of Biomolecule, biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g., sucrose being broken down into glucose and fructose), this is recognized as saccharification. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water. Types Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both the su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyromitra Esculenta
''Gyromitra esculenta'' is an ascomycete fungus from the genus ''Gyromitra'', widely distributed across Europe and North America. It normally fruits in sandy soils under coniferous trees in spring and early summer. The Ascocarp, fruiting body, or mushroom, is an irregular brain-shaped Pileus (mycology), cap, dark brown in colour, that can reach high and wide, perched on a stout white stipe (mycology), stipe up to high. Although potentially fatal if eaten raw (causing restrictions on its sales in some areas), ''G. esculenta'' is still commonly parboiled for consumption, being a popular delicacy in Europe and the upper Great Lakes region of North America; evidence suggests that thorough cooking does not eliminate all traces of mycotoxins. When consumed, the principal active mycotoxin, gyromitrin, is hydrolyzed into the toxic compound monomethylhydrazine, which hepatotoxicity, affects the liver, neurotoxicity, central nervous system, and sometimes the nephrotoxicity, kid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyromitra
''Gyromitra'' () is a genus of about 18 species of ascomycete fungi. They are a false morel - a frequently toxic mushroom that can be mistaken for edible mushrooms of the genus ''Morchella'' (morels). Taxonomy The name ''Gyromitra'' comes from ''gyro'' meaning ''convoluted'' and ''mitra'' meaning ''turban''. Analysis of the ribosomal DNA of many of the Pezizales showed the genus ''Gyromitra'' to be most closely related to the genus '' Discina'', and also '' Pseudorhizina'', '' Hydnotrya'', and only distantly related to '' Helvella''. Thus the four genera are now included in the family Discinaceae. Species The genus consists of the following species: * '' Gyromitra accumbens'' Harmaja (1986) * '' Gyromitra apiculatula'' (McKnight) Berthet (1972) * '' Gyromitra arctica'' Vassilkov (1969) * '' Gyromitra bubakii'' Velen. (1922) * '' Gyromitra californica'' (W. Phillips) Raitv. (1965) * '' Gyromitra chirripoensis'' L.D. Gómez (1972) * '' Gyromitra columbiana'' Harmaja (1986) * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mushroom
A mushroom or toadstool is the fleshy, spore-bearing Sporocarp (fungi), fruiting body of a fungus, typically produced above ground on soil or another food source. ''Toadstool'' generally refers to a poisonous mushroom. The standard for the name "mushroom" is the cultivated white button mushroom, ''Agaricus bisporus''; hence, the word "mushroom" is most often applied to those fungi (Basidiomycota, Agaricomycetes) that have a stem (Stipe (mycology), stipe), a cap (Pileus (mycology), pileus), and gills (lamellae, sing. Lamella (mycology), lamella) on the underside of the cap. "Mushroom" also describes a variety of other gilled fungi, with or without stems; therefore the term is used to describe the fleshy fruiting bodies of some Ascomycota. The gills produce microscopic Spore#Fungi, spores which help the fungus spread across the ground or its occupant surface. Forms deviating from the standard Morphology (biology), morphology usually have more specific names, such as "bolete", " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
