Furin: A proprotein convertase with specificity for the proproteins of PROALBUMIN; COMPLEMENT 3C; and VON WILLEBRAND FACTOR. It has specificity for cleavage near paired ARGININE residues that are separated by two amino acids.Spike Glycoprotein, Coronavirus: A class I viral fusion protein that forms the characteristic spikes, or peplomers, found on the viral surface that mediate virus attachment, fusion, and entry into the host cell. During virus maturation, it is cleaved into two subunits: S1, which binds to receptors in the host cell, and S2, which mediates membrane fusion.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Cryoelectron Microscopy: Electron microscopy involving rapid freezing of the samples. The imaging of frozen-hydrated molecules and organelles permits the best possible resolution closest to the living state, free of chemical fixatives or stains.Editorial Policies: The guidelines and policy statements set forth by the editor(s) or editorial board of a publication.Subtilisins: A family of SERINE ENDOPEPTIDASES isolated from Bacillus subtilis. EC 3.4.21.-SARS Virus: A species of CORONAVIRUS causing atypical respiratory disease (SEVERE ACUTE RESPIRATORY SYNDROME) in humans. The organism is believed to have first emerged in Guangdong Province, China, in 2002. The natural host is the Chinese horseshoe bat, RHINOLOPHUS sinicus.Antibodies: Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).Antibody Specificity: The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Antibodies, Bacterial: Immunoglobulins produced in a response to BACTERIAL ANTIGENS.Governing Board: The group in which legal authority is vested for the control of health-related institutions and organizations.Transcription Factor CHOP: A CCAAT-enhancer binding protein that is induced by DNA DAMAGE and growth arrest. It serves as a dominant negative inhibitor of other CCAAT-enhancer binding proteins.Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Ships: Large vessels propelled by power or sail used for transportation on rivers, seas, oceans, or other navigable waters. Boats are smaller vessels propelled by oars, paddles, sail, or power; they may or may not have a deck.Pasteurellosis, Pneumonic: Bovine respiratory disease found in animals that have been shipped or exposed to CATTLE recently transported. The major agent responsible for the disease is MANNHEIMIA HAEMOLYTICA and less commonly, PASTEURELLA MULTOCIDA or HAEMOPHILUS SOMNUS. All three agents are normal inhabitants of the bovine nasal pharyngeal mucosa but not the LUNG. They are considered opportunistic pathogens following STRESS, PHYSIOLOGICAL and/or a viral infection. The resulting bacterial fibrinous BRONCHOPNEUMONIA is often fatal.Specialty Boards: Organizations which certify physicians and dentists as specialists in various fields of medical and dental practice.Transportation: The means of moving persons, animals, goods, or materials from one place to another.Therapies, Investigational: Treatments which are undergoing clinical trials or for which there is insufficient evidence to determine their effects on health outcomes; coverage for such treatments is often denied by health insurers.Drug Industry: That segment of commercial enterprise devoted to the design, development, and manufacture of chemical products for use in the diagnosis and treatment of disease, disability, or other dysfunction, or to improve function.Double-Blind Method: A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Placebos: Any dummy medication or treatment. Although placebos originally were medicinal preparations having no specific pharmacological activity against a targeted condition, the concept has been extended to include treatments or procedures, especially those administered to control groups in clinical trials in order to provide baseline measurements for the experimental protocol.Drug Administration Schedule: Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience.Biotechnology: Body of knowledge related to the use of organisms, cells or cell-derived constituents for the purpose of developing products which are technically, scientifically and clinically useful. Alteration of biologic function at the molecular level (i.e., GENETIC ENGINEERING) is a central focus; laboratory methods used include TRANSFECTION and CLONING technologies, sequence and structure analysis algorithms, computer databases, and gene and protein structure function analysis and prediction.Estranes: A group of compounds forming the nucleus of the estrogenic steroid family.Receptor, Muscarinic M4: A specific subtype of muscarinic receptor found in the CORPUS STRIATUM and the LUNG. It has similar receptor binding specificities to MUSCARINIC RECEPTOR M1 and MUSCARINIC RECEPTOR M2.Nitriles: Organic compounds containing the -CN radical. The concept is distinguished from CYANIDES, which denotes inorganic salts of HYDROGEN CYANIDE.Pyridines: Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.Norandrostanes: Androstanes in which ring contractions have occurred or which are lacking carbon-18. Compounds with any degree of unsaturation are included. Androstanes which are lacking carbon-19 are ESTRANES.Ferrets: Semidomesticated variety of European polecat much used for hunting RODENTS and/or RABBITS and as a laboratory animal. It is in the subfamily Mustelinae, family MUSTELIDAE.Terminology as Topic: The terms, expressions, designations, or symbols used in a particular science, discipline, or specialized subject area.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.Euthanasia, Animal: The killing of animals for reasons of mercy, to control disease transmission or maintain the health of animal populations, or for experimental purposes (ANIMAL EXPERIMENTATION).Albinism, Ocular: Albinism affecting the eye in which pigment of the hair and skin is normal or only slightly diluted. The classic type is X-linked (Nettleship-Falls), but an autosomal recessive form also exists. Ocular abnormalities may include reduced pigmentation of the iris, nystagmus, photophobia, strabismus, and decreased visual acuity.Carnivora: An order of MAMMALS, usually flesh eaters with appropriate dentition. Suborders include the terrestrial carnivores Fissipedia, and the aquatic carnivores PINNIPEDIA.Adrenal Cortex Neoplasms: Tumors or cancers of the ADRENAL CORTEX.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Phthalimides: The imide of phthalic acids.Captan: One of the phthalimide fungicides.Biological Products: Complex pharmaceutical substances, preparations, or matter derived from organisms usually obtained by biological methods or assay.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)Cyclization: Changing an open-chain hydrocarbon to a closed ring. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Chemistry, Organic: The study of the structure, preparation, properties, and reactions of carbon compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)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.Severe Acute Respiratory Syndrome: A viral disorder characterized by high FEVER, dry COUGH, shortness of breath (DYSPNEA) or breathing difficulties, and atypical PNEUMONIA. A virus in the genus CORONAVIRUS is the suspected agent.Viral Envelope Proteins: Layers of protein which surround the capsid in animal viruses with tubular nucleocapsids. The envelope consists of an inner layer of lipids and virus specified proteins also called membrane or matrix proteins. The outer layer consists of one or more types of morphological subunits called peplomers which project from the viral envelope; this layer always consists of glycoproteins.Virion: The infective system of a virus, composed of the viral genome, a protein core, and a protein coat called a capsid, which may be naked or enclosed in a lipoprotein envelope called the peplos.Junin virus: A species of ARENAVIRUS, part of the New World Arenaviruses (ARENAVIRUSES, NEW WORLD), causing Argentinian hemorrhagic fever. The disease is characterized by congestion, edema, generalized lymphadenopathy and hemorrhagic necrosis and is sometimes fatal.