| 单词 | sterilization | ||||||
| 释义 | sterilizationster·il·izeS0745500 (stĕr′ə-līz′)sterilization(ˌstɛrɪlaɪˈzeɪʃən) orsterilisationsterilization
sterilizationnounsterile(ˈsterail) adjectiveSterilizationSterilizationAn act of destroying all forms of life on and in an object. A substance is sterile, from a microbiological point of view, when it is free of all living microorganisms. Sterilization is used principally to prevent spoilage of food and other substances and to prevent the transmission of diseases by destroying microbes that may cause them in humans and animals. Microorganisms can be killed either by physical agents, such as heat and irradiation, or by chemical substances. Heat sterilization is the most common method of sterilizing bacteriological media, foods, hospital supplies, and many other substances. Either moist heat (hot water or steam) or dry heat can be employed, depending upon the nature of the substance to be sterilized. Moist heat is also used in pasteurization, which is not considered a true sterilization technique because all microorganisms are not killed; only certain pathogenic organisms and other undesirable bacteria are destroyed. See Pasteurization Many kinds of radiations are lethal, not only to microorganisms but to other forms of life. These radiations include both high-energy particles as well as portions of the electromagnetic spectrum. See Radiation biology Filtration sterilization is the physical removal of microorganisms from liquids by filtering through materials having relatively small pores. Sterilization by filtration is employed with liquid that may be destroyed by heat, such as blood serum, enzyme solutions, antibiotics, and some bacteriological media and medium constituents. Examples of such filters are the Berkefeld filter (diatomaceous earth), Pasteur-Chamberland filter (porcelain), Seitz filter (asbestos pad), and the sintered glass filter. Chemicals are used to sterilize solutions, air, or the surfaces of solids. Such chemicals are called bactericidal substances. In lower concentrations they become bacteriostatic rather than bactericidal; that is, they prevent the growth of bacteria but may not kill them. Other terms having similar meanings are employed. A disinfectant is a chemical that kills the vegetative cells of pathogenic microorganisms but not necessarily the endospores of spore-forming pathogens. An antiseptic is a chemical applied to living tissue that prevents or retards the growth of microorganisms, especially pathogenic bacteria, but which does not necessarily kill them. The desirable features sought in a chemical sterilizer are toxi-city to microorganisms but nontoxicity to humans and animals, stability, solubility, inability to react with extraneous organic materials, penetrative capacity, detergent capacity, noncorro-siveness, and minimal undesirable staining effects. Rarely does one chemical combine all these desirable features. Among chemicals that have been found useful as sterilizing agents are the phenols, alcohols, chlorine compounds, iodine, heavy metals and metal complexes, dyes, and synthetic detergents, including the quaternary ammonium compounds. Sterilization(1) The method by which a substance, object, or food product is completely freed of live microorganisms. The most common sterilization techniques are heat sterilization and filtration sterilization; the latter is used with liquids and is characterized by the removal of microbial cells with filters. The vegetative cells of most bacteria, yeasts, and microscopic fungi die at temperatures of 50°-70°C within 30 min, whereas the spores of many bacteria can withstand prolonged boiling. This explains why high temperatures are used in sterilization. The simplest sterilization method is heating metal and glass objects on a flame burner. Hot-air sterilization is conducted in hot-air sterilizers at temperatures of 160°-165°C for two hours (hr). This method is used to sterilize laboratory glassware, metal objects, some powder-like materials, and substances that are not damaged by heating. Moist-heat sterilization is carried out in autoclaves with steam under pressure. Microorganic nutrient mediums are sterilized at 4 atmospheres (atm) and 121°C for 20–30 min or at 0.5 atm and 112°C for 20 min. Surgical instruments, dressings, and sutures and various canned foods are usually sterilized at 1 atm for 30 min. Soil may be sterilized only at 2 atm and 134°C for 2 hr. Some liquids and solutions cannot be sterilized at high temperatures because the temperatures cause the evaporation or inacti-vation of vitamins and other biologically active compounds, the decomposition of drugs, the caramelization of sugars, and the de-naturation of proteins. Under these conditions, heat is not used, and liquids are passed through bacteriological filters having fine pores. Chemical sterilization is used on solid objects that may be damaged by heat, for example, some plastics and electronic apparatus. Chemical sterilizing agents include gases (ethylene oxide mixed with C02 or methyl bromide), alcohol, and mercuric chloride solutions. Radiation sterilization, with doses of ionizing radiation usually at 3–10 million rads, can also be used on solid objects that may be damaged by heat. The number of microorganisms present in the air of enclosed areas, including operating rooms and plants where antibiotics are packaged, can be reduced by ultraviolet radiation, which is bactericidal. Sterilization is widely used in microbiological and other scientific research, in medicine, and in the food-processing industry. Spacecraft are sterilized in order to prevent the possible contamination of other planets by microorganisms from earth. Sterility is demonstrated by the complete absence of live microorganisms within an object. For this purpose, liquid or solid nutrient-rich mediums are inoculated to allow for the growth of cells that have been damaged but not completely destroyed. A. A. IMSHENETSKII (2) The surgical procedure by which an individual is made incapable of reproduction. Unlike castration, the hormonal regulation of sexual function is maintained. sterilization[‚ster·ə·lə′zā·shən]sterilizationsterilization[ster″il-ĭ-za´shun]In sterilizing objects or substances, the high resistance of bacterial spore cells must be taken into account. Most dangerous bacteria are destroyed at a temperature of 50° to 60°C, so that pasteurization of fluid, which is the application of heat at about 60°C, destroys disease-causing bacteria. However, temperatures almost twice as high are usually required to destroy the spore cells. The discovery that heat, in the form of flame, steam, or hot water, kills bacteria made possible the advances of modern surgery, which is based on freedom from microorganisms, or asepsis, and prevention of contamination. Sterilization of all equipment used during operations and other procedures, and of anything that in any way may touch an field" >operative field, is carried out scrupulously. Health care providers all wear sterile clothing. Instruments are sterilized by boiling, by chemical antiseptics, or by use of an autoclave. Gamma sterilization uses the radioisotope cobalt 60 as the energy source to sterilize some medical supply products. It has the advantages of penetrating all types of packaging, decreasing quarantine time, requiring fewer personnel, and allowing for bulk processing. ster·il·i·za·tion(ster'ĭl-i-zā'shŭn),sterilizationReproduction medicine The process of rendering an organism or person inconceivable, irreproducible, or infertile, through tubal ligation, vasectomy, or orchiectomy. See Involuntary sterilization, Thermic sterilization, Surgical sterilization, Voluntary sterilization.ster·il·i·za·tion(ster'i-lī-zā'shŭn)sterilizationsterilization
sterilizationster·il·i·za·tion(ster'i-lī-zā'shŭn)Patient discussion about sterilizationQ. Is it good to put alcohol on burns? If I get a burn- should I sterilize it with alcohol to prevent infections? SterilizationSterilizationA medical procedure where the reproductive organs are removed or rendered ineffective. Legally mandated sterilization of criminals, or other members of society deemed "socially undesirable," has for some time been considered a stain on the history of U.S. law. The practice, also known as eugenics, originated early in the twentieth century. In 1914, a Model Eugenical Sterilization Law was published by Harry Laughlin at the Eugenics Records Office. Laughlin proposed the sterilization of "socially inadequate" persons, which translated as anyone "maintained wholly or in part by public expense." This would include the "feebleminded, insane, blind, deaf, orphans, and the homeless." At the time the model law was published, 12 states had enacted sterilization laws. Such laws were seen to benefit society since they presumably reduced the burden on taxpayers of maintaining state-run facilities. Eventually, these laws were challenged in court. In Buck v. Bell, 274 U.S. 200 (1927), oliver wendell holmes jr. wrote the infamous opinion that upheld the constitutionality of a Virginia sterilization law, fueling subsequent legislative efforts to enact additional sterilization laws. By 1930, 30 states and Puerto Rico had passed laws mandating sterilization for many criminal or moral offenses. Nearly all of the states with such laws imposed mandatory sterilization of mentally defective citizens. Nineteen states required sterilization for parents of children likely to experience various disorders. Six states encouraged sterilization for individuals whose children might be "socially inadequate." Finally, the Supreme Court struck down an Oklahoma law mandating involuntary sterilization for repeat criminals in Skinner v. Oklahoma, 316 U.S. 535, 62 S. Ct. 1110, 86 L. Ed. 1655 (1942). Justice william o. douglas's opinion broadly defined the right to privacy to include the right to procreate, and concluded that the government's power to sterilize interfered with an individual's basic liberties. By mid-century, legal attitudes had changed, and many state sterilization laws were held to be unconstitutional under the Eighth Amendment prohibiting Cruel and Unusual Punishment. Further readingsCarlson, Elof Axel. 2001. The Unfit: A History of a Bad Idea. Cold Spring Harbor, N.Y.: Cold Spring Harbor Laboratory Press. Kevles, Daniel J. 1985. In the Name of Eugenics. New York: Knopf. Smith, J. David, and K. Ray Nelson. 1999. The Sterilization of Carrie Buck. Far Hills, N.J.: New Horizon Press. SterilizationSterilizationsterilization
Synonyms for sterilization
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sterilization - the act of making an organism barren or infertile (unable to reproduce)