Astatine is a chemical element with the symbol At and atomic number 85. It is the rarest naturally occurring element in the Earth's crust, occurring only as the decay product of various heavier elements. All of astatine's isotopes are short-lived; the most stable is astatine-210, with a half-life of 8.1 hours. A sample of the pure element has never been assembled, because any macroscopic specimen would be immediately vaporized by the heat of its radioactivity.
The periodic table, also known as the periodic table of the (chemical) elements, is a rows and columns arrangement of the chemical elements. It is widely used in chemistry, physics, and other sciences, and is generally seen as an icon of chemistry. It is a graphic formulation of the periodic law, which states that the properties of the chemical elements exhibit an approximate periodic dependence on their atomic numbers. The table is divided into four roughly rectangular areas called blocks. The rows of the table are called periods, and the columns are called groups. Elements from the same group of the periodic table show similar chemical characteristics. Trends run through the periodic table, with nonmetallic character increasing from left to right across a period, and from down to up across a group, and metallic character increasing in the opposite direction. The underlying reason for these trends is electron configurations of atoms. The periodic table exclusively lists electrically neutral atoms that have an equal number of positively charged protons and negatively charged electrons and puts isotopes at the same place. Other atoms, like nuclides and isotopes, are graphically collected in other tables like the tables of nuclides.
Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer (passivation) somewhat stabilizes the free metal against further oxidation.
In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation of an atom in a chemical compound. Conceptually, the oxidation state may be positive, negative or zero. While fully ionic bonds are not found in nature, many bonds exhibit strong ionicity, making oxidation state a useful predictor of charge.
In chemistry, a group is a column of elements in the periodic table of the chemical elements. There are 18 numbered groups in the periodic table; the 14 f-block columns, between groups 2 and 3, are not numbered. The elements in a group have similar physical or chemical characteristics of the outermost electron shells of their atoms, because most chemical properties are dominated by the orbital location of the outermost electron.
In organic chemistry, a carbonyl group is a functional group with the formula C=O, composed of a carbon atom double-bonded to an oxygen atom, and it is divalent at the C atom. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containing a carbonyl group is often referred to as a carbonyl compound.
Methylamine is an organic compound with a formula of CH3NH2. 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.
The androgen receptor (AR), also known as NR3C4, is a type of nuclear receptor that is activated by binding any of the androgenic hormones, including testosterone and dihydrotestosterone, in the cytoplasm and then translocating into the nucleus. The androgen receptor is most closely related to the progesterone receptor, and progestins in higher dosages can block the androgen receptor.
Richard Neil Zare is the Marguerite Blake Wilbur Professor in Natural Science and a Professor of Chemistry at Stanford University. Throughout his career, Zare has made a considerable impact in physical chemistry and analytical chemistry, particularly through the development of laser-induced fluorescence (LIF) and the study of chemical reactions at the molecular and nanoscale level. LIF is an extremely sensitive technique with applications ranging from analytical chemistry and molecular biology to astrophysics. One of its applications was the sequencing of the human genome.
The aryl hydrocarbon receptor is a protein that in humans is encoded by the AHR gene. The aryl hydrocarbon receptor is a transcription factor that regulates gene expression. It was originally thought to function primarily as a sensor of xenobiotic chemicals and also as the regulator of enzymes such as cytochrome P450s that metabolize these chemicals. The most notable of these xenobiotic chemicals are aromatic (aryl) hydrocarbons from which the receptor derives its name.
Neuropeptide Y receptors are a family of receptors belonging to class A G-protein coupled receptors and they are activated by the closely related peptide hormones neuropeptide Y, peptide YY and pancreatic polypeptide. These receptors are involved in the control of a diverse set of behavioral processes including appetite, circadian rhythm, and anxiety.
Alpha-(1,3)-fucosyltransferase is an enzyme that in humans is encoded by the FUT7 gene.
Zinc finger protein 10 is a protein that in humans is encoded by the ZNF10 gene.
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reactive, as it reacts with all other elements except for the light inert gases.
Arylcyclohexylamines, also known as arylcyclohexamines or arylcyclohexanamines, are a chemical class of pharmaceutical, designer, and experimental drugs.
MN-25 (UR-12) is a drug invented by Bristol-Myers Squibb, that acts as a reasonably selective agonist of peripheral cannabinoid receptors. It has moderate affinity for CB2 receptors with a Ki of 11 nM, but 22x lower affinity for the psychoactive CB1 receptors with a Ki of 245 nM. The indole 2-methyl derivative has the ratio of affinities reversed however, with a Ki of 8 nM at CB1 and 29 nM at CB2, which contrasts with the usual trend of 2-methyl derivatives having increased selectivity for CB2 (cf. JWH-018 vs JWH-007, JWH-081 vs JWH-098).
Proteins are present in wine. The most common proteins include thaumatin-like proteins and chitinases and have a role in the formation of turbidity (haze) especially visible in white wine. The quantity of haze forming is dependent on the quantity of phenolics in the wine.
Judith P. Klinman is an American chemist, biochemist, and molecular biologist known for her work on enzyme catalysis. She became the first female professor in the physical sciences at the University of California, Berkeley in 1978, where she is now Professor of the Graduate School and Chancellor's Professor. In 2012, she was awarded the National Medal of Science by President Barack Obama. She is a member of the National Academy of Sciences, American Academy of Arts and Sciences, American Association for the Advancement of Science, and the American Philosophical Society.
Stigmastane or 24R-ethylcholestane is a tetracyclic triterpene, along with cholestane and ergostane, this sterane is used as a biomarker for early eukaryotes.
Campestane or 24R-methylcholestane is a tetracyclic triterpene. Its derivative campesterol (campest-5-en-3β-ol) was first isolated from the rapeseed, hence the name.
