| 释义 |
DictionarySeesterilizationgas sterilization
gas sterilization[¦gas ‚ster·ə·lə′zā·shən] (microbiology) Sterilization of heat and liquid-labile materials by means of gaseous agents, such as formaldehyde, ethylene oxide, and β-propiolactone. gas sterilization
sterilization [ster″il-ĭ-za´shun] 1. the process of rendering an individual incapable of reproduction" >sexual reproduction, by castration, vasectomy, salpingectomy, or some other procedure. Endoscopic techniques for female sterilization that can be performed outside of a hospital without general anesthesia include culdoscopic, hysteroscopic, and laparoscopic sterilization (see subentries below).2. the process of destroying all microorganisms and their pathogenic products. It can be accomplished by any of various methods, including heat (usually wet steam under pressure at 121°C for 15 minutes), gas plasma, irradiation, or a bactericidal chemical compound such as ethylene oxide, peracetic acid, or aqueous glutaraldehyde. The probability that a given process has made something sterile is known as its level" >sterility assurance level. A level of 10−6 is recommended for organisms on a sterilized device.
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.culdoscopic sterilization use of an endoscope to visualize the fallopian tubes and ovaries for the purpose of preventing conception. The endoscope is inserted through an incision in the posterovaginal cervix. After the fallopian tubes are located, each tube is drawn out through the vaginal incision and severed. The major advantage of this procedure is that it can be done on an outpatient basis. A disadvantage is the complication of infection, a very real possibility owing to the unsterile nature of the vagina.flash sterilization sterilization of unwrapped equipment at 132°C for three to ten minutes using steam.gas sterilization sterilization by means of a bactericidal gas, frequently used for items that are heat and moisture sensitive. Ethylene oxide is the gas most often used; it is highly explosive and flammable in the presence of air, but these hazards are reduced by diluting it with carbon dioxide or fluorinated hydrocarbons. Gas sterilization is a chemical process resulting from reaction of chemical groups in the bacterial cell with the gas. Factors influencing gas sterilization include time of exposure, gas concentration, penetration of the gas, and temperature and humidity in the sterilizing chamber. Automatically controlled ethylene oxide sterilizers are usually heated to a temperature of 54°C (130°F). A humidity level of 35 to 70 per cent is recommended.hysteroscopic sterilization use of an endoscopic instrument to visualize the interior of the uterus and fallopian tubes for the purpose of preventing conception. The hysteroscope is inserted through the dilated cervix and on through the uterine cavity to the point at which each tube joins the uterus. A cautery is then used to electrocoagulate each tube. Occlusion of the tubes is accomplished by scar tissue that forms at the sites of cauterization.laparoscopic sterilization that which employs an endoscope to visualize the fallopian tubes and surrounding structures for the purpose of occluding the tubes. The instrument is guided into the abdominal cavity through a small puncture made by a trocar inserted immediately below the umbilicus. A second small puncture is made in the lower abdomen through which cautery forceps are inserted. The forceps are applied approximately 2 cm from the point at which each of the tubes joins the uterus. In this way each tube is electrocoagulated and severed. An alternative to cauterization and severance of the tubes is the application of clips. However, there is the possibility that the clips may not completely occlude the tubes, allowing passage of the ovum and impregnation.terminal sterilization the final sterilization of instruments and equipment following use, thereby rendering them safe for handling.gas ster·i·li·za·tion (gas ster'i-lī-zāshŭn) A technique for killing all microorganisms using ethylene oxide gas under pressure; used only for material and supplies that cannot withstand steam sterilizing. low-tem·per·a·ture ster·i·li·za·tion (lō tempĕr-ă-chŭr steri-lī-zāshŭn) Disinfection of items customarily with ethylene oxide gas; usually accomplished at ambient temperatures or temperatures below those used for autoclave, chemical vapor, or dry-heat oven sterilization.
Synonym(s): gas sterilization. FinancialSeeSterilization |