Stereoisomerism: The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Aporphines: Dibenzoquinolines derived in plants from (S)-reticuline (BENZYLISOQUINOLINES).Phenmetrazine: A sympathomimetic drug used primarily as an appetite depressant. Its actions and mechanisms are similar to DEXTROAMPHETAMINE.Candy: Sweet food products combining cane or beet sugars with other carbohydrates and chocolate, milk, eggs, and various flavorings. In the United States, candy refers to both sugar- and cocoa-based confections and is differentiated from sweetened baked goods; elsewhere the terms sugar confectionary, chocolate confectionary, and flour confectionary (meaning goods such as cakes and pastries) are used.Hallucinations: Subjectively experienced sensations in the absence of an appropriate stimulus, but which are regarded by the individual as real. They may be of organic origin or associated with MENTAL DISORDERS.Lethargy: A general state of sluggishness, listless, or uninterested, with being tired, and having difficulty concentrating and doing simple tasks. It may be related to DEPRESSION or DRUG ADDICTION.Designer Drugs: Drugs designed and synthesized, often for illegal street use, by modification of existing drug structures (e.g., amphetamines). Of special interest are MPTP (a reverse ester of meperidine), MDA (3,4-methylenedioxyamphetamine), and MDMA (3,4-methylenedioxymethamphetamine). Many drugs act on the aminergic system, the physiologically active biogenic amines.Metals: Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)Electrons: Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.X-Ray Absorption Spectroscopy: Analysis of the energy absorbed across a spectrum of x-ray energies/wavelengths to determine the chemical structure and electronic states of the absorbing medium.Ferrous Compounds: Inorganic or organic compounds that contain divalent iron.Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Metalloporphyrins: Porphyrins which are combined with a metal ion. The metal is bound equally to all four nitrogen atoms of the pyrrole rings. They possess characteristic absorption spectra which can be utilized for identification or quantitative estimation of porphyrins and porphyrin-bound compounds.Blogging: Using an INTERNET based personal journal which may consist of reflections, comments, and often hyperlinks.Chemistry, Organic: The study of the structure, preparation, properties, and reactions of carbon compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Training Support: Financial support for training including both student stipends and loans and training grants to institutions.Organic Chemistry Phenomena: The conformation, properties, reaction processes, and the properties of the reactions of carbon compounds.Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Information Storage and Retrieval: Organized activities related to the storage, location, search, and retrieval of information.Aphasia: A cognitive disorder marked by an impaired ability to comprehend or express language in its written or spoken form. This condition is caused by diseases which affect the language areas of the dominant hemisphere. Clinical features are used to classify the various subtypes of this condition. General categories include receptive, expressive, and mixed forms of aphasia.Aphasia, Wernicke: Impairment in the comprehension of speech and meaning of words, both spoken and written, and of the meanings conveyed by their grammatical relationships in sentences. It is caused by lesions that primarily affect Wernicke's area, which lies in the posterior perisylvian region of the temporal lobe of the dominant hemisphere. (From Brain & Bannister, Clinical Neurology, 7th ed, p141; Kandel et al., Principles of Neural Science, 3d ed, p846)Aphasia, Broca: An aphasia characterized by impairment of expressive LANGUAGE (speech, writing, signs) and relative preservation of receptive language abilities (i.e., comprehension). This condition is caused by lesions of the motor association cortex in the FRONTAL LOBE (BROCA AREA and adjacent cortical and white matter regions).Aphasia, Primary Progressive: A progressive form of dementia characterized by the global loss of language abilities and initial preservation of other cognitive functions. Fluent and nonfluent subtypes have been described. Eventually a pattern of global cognitive dysfunction, similar to ALZHEIMER DISEASE, emerges. Pathologically, there are no Alzheimer or PICK DISEASE like changes, however, spongiform changes of cortical layers II and III are present in the TEMPORAL LOBE and FRONTAL LOBE. (From Brain 1998 Jan;121(Pt 1):115-26)Anomia: A language dysfunction characterized by the inability to name people and objects that are correctly perceived. The individual is able to describe the object in question, but cannot provide the name. This condition is associated with lesions of the dominant hemisphere involving the language areas, in particular the TEMPORAL LOBE. (From Adams et al., Principles of Neurology, 6th ed, p484)Aphasia, Conduction: A type of fluent aphasia characterized by an impaired ability to repeat one and two word phrases, despite retained comprehension. This condition is associated with dominant hemisphere lesions involving the arcuate fasciculus (a white matter projection between Broca's and Wernicke's areas) and adjacent structures. Like patients with Wernicke aphasia (APHASIA, WERNICKE), patients with conduction aphasia are fluent but commit paraphasic errors during attempts at written and oral forms of communication. (From Adams et al., Principles of Neurology, 6th ed, p482; Brain & Bannister, Clinical Neurology, 7th ed, p142; Kandel et al., Principles of Neural Science, 3d ed, p848)Primary Progressive Nonfluent Aphasia: A form of frontotemporal lobar degeneration and a progressive form of dementia characterized by motor speech impairment and AGRAMMATISM, with relative sparing of single word comprehension and semantic memory.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Codon: A set of three nucleotides in a protein coding sequence that specifies individual amino acids or a termination signal (CODON, TERMINATOR). Most codons are universal, but some organisms do not produce the transfer RNAs (RNA, TRANSFER) complementary to all codons. These codons are referred to as unassigned codons (CODONS, NONSENSE).Ribosomes: Multicomponent ribonucleoprotein structures found in the CYTOPLASM of all cells, and in MITOCHONDRIA, and PLASTIDS. They function in PROTEIN BIOSYNTHESIS via GENETIC TRANSLATION.RNA: A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)RNA, Ribosomal: The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)Polymers: Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).RNA, Transfer: The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.Viral Structures: The structural parts of the VIRION.Denture, Partial, Temporary: A partial denture intended for short-term use in a temporary or emergency situation.Compact Disks: Computer disks storing data with a maximum reduction of space and bandwidth. The compact size reduces cost of transmission and storage.Avibirnavirus: A genus of RNA viruses in the family BIRNAVIRIDAE infecting birds. It is transmitted horizontally with no known vectors. The type species is INFECTIOUS BURSAL DISEASE VIRUS.Physiology: The biological science concerned with the life-supporting properties, functions, and processes of living organisms or their parts.Physicochemical Processes: Physical reactions involved in the formation of or changes in the structure of atoms and molecules and their interactions.Drug Repositioning: The deliberate and methodical practice of finding new applications for existing drugs.Databases, Pharmaceutical: Databases devoted to knowledge about PHARMACEUTICAL PRODUCTS.Drug Discovery: The process of finding chemicals for potential therapeutic use.Textbooks as Topic: Books used in the study of a subject that contain a systematic presentation of the principles and vocabulary of a subject.Evolution, Chemical: Chemical and physical transformation of the biogenic elements from their nucleosynthesis in stars to their incorporation and subsequent modification in planetary bodies and terrestrial biochemistry. It includes the mechanism of incorporation of biogenic elements into complex molecules and molecular systems, leading up to the origin of life.Organic Chemistry Processes: The reactions, changes in structure and composition, the properties of the reactions of carbon compounds, and the associated energy changes.North CarolinaBiochemistry: The study of the composition, chemical structures, and chemical reactions of living things.Chemistry, Inorganic: A field of chemistry which pertains to chemical compounds or ions that do not contain the element carbon (with the exception of carbon dioxide and compounds containing a carbonate radical, e.g., calcium carbonate).Alkadienes: Acyclic branched or unbranched hydrocarbons having two carbon-carbon double bonds.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Alkenes: Unsaturated hydrocarbons of the type Cn-H2n, indicated by the suffix -ene. (Grant & Hackh's Chemical Dictionary, 5th ed, p408)