Sterilisation effect

Disinfectant Surface applied Mostly antibacterial Prevent discoloration Prevent odours Sterilising effect Eliminate contamination Short life... 

At the same time this method of insect sterilisation involves the hazard of various toxic side-effects, as interference in DNA synthesis may lead to teratogenic, mutagenic and carcinogenic effects or sterilising effects on mammals (Klassen and Chang, 1966 Hayes, 1964 Palmquist and La Chance, 1966 Barnes, 1964). 

DeMilo and co-workers (1974) reported on the male sterility of houseflies induced by 2,5-dichloro-N-(2,4-dinitrophenyl)-benzenesulfonamide (36). In subsequent studies aimed at optimalisation of the sterilising effectiveness, they found the 3,4-dichloro-analogue (37) to be the most active, within this group (DeMilo et al., 1977). 

Ascher and co-workers (Ascher and Rones, 1964 Ascher and Nissim, 1964), as well as Murbach and Corbaz (1963) reported on the antifeedant activity of triphenyltins such as triphenyltin hydroxyde (2) and triphenyltin acetate (3) known as fungicides under the names Du-Ter and Brestan , respectively. Later these compounds were reported to show sterilising effect, too (see Section 1.9). 

Reports of sterilisation (qv) against bacteria by nonthermal effects have appeared, but it is generally beheved that the effect is only that of heating (164). Because microwave heating often is not uniform, studies in this area can be seriously flawed by simplistic assumptions of uniform sample temperature. 

In the 1970s questions were raised about certain immunological complications as a consequence of male sterilisation or vasectomy. Clinical epidemiological data do not appear to indicate that this actually occurs in clinical practice. No significant long-term side effects of male sterilisation have been demonstrated. 

Because of the increa sing worldwide interest and demand for simple, effective, and inexpensive female sterilisation, a variety of procedures and methods have been developed. These approaches differ whether they are performed postpartum, postabortum, or in interval situations. The choice of methods also largely depends upon the physician s prior training, knowledge, and experience. Excellent reviews have been written on sterilisation (98). 

Humidity can be a problem. Whereas it was shown (284) that 33% RH was best for spore inactivation, and that at least 30% RH was needed for effective sterilisation (285), dried spores are difficult to kill, and the spore substrate material and wrappings compete with the spore for the available moisture (286). Therefore, the relative humidity is adjusted to 50—70% to provide sufficient moisture for the spores to equiUbrate. The exposure time depends upon the gas mixture, the concentration of ethylene oxide, the load to be sterilised, the level of contamination, and the spore reduction assurance requited. It may be anywhere from 4—24 hours. In a mn, cycles of pre-conditioning and humidification, gassing, exposure, evacuation, and air washing (Fig. 9) are automatically controlled. 

Revie, R. W. and Greene, N. D., Corrosion Behaviour of Surgical Implant Materials 1 Effects of Sterilisation , Corrosion Science, 9, 755-761 (1969)... 

The oil film present on both types of tinplate and on newly hot-dipped tinware has a slight protective value. The passivation processes have much more effect but this is unlikely to compensate for a substantial reduction in coating weight. The effects of oil and passivation on the outside of tinplate cans may be reduced during can manufacture, filling and sterilisation. 

True. Batch cultures give lower overall outputs than continuous cultures, as they suffer from non-productive down-time (the time taken to empty, clean, re-sterilise and re-fill the fermentor). After inoculation, considerable time can be taken for biomass to build up to a level where substrates are effectively utilised. Continuous cultures do not suffer such drawbacks once they are in operation. 

All feed streams are sterilised before being metered into the fermentation vessel. Contaminants resistant to the antibiotic rarely find their way into the fermenter. When they find a way to contaminate media, their effects are so catastrophic that prevention is of paramount importance. A resistant, (3-lactamase producing, fast-growing bacterial contaminant can destroy the penicillin.5 The contaminants not only consume nutrients intended for the fungus, but also cause loss of pH control and interference with the subsequent extraction process. 

This is a special chemical effectively used for column bioreactors. It is a volatile compound and strong oxidising agent. It boils at ambient temperature, therefore the solution of ethylene oxide (liquid phase) must be stored in a refrigerator (4 °C). An excellent oxidising agent such as a 3% sodium hypochlorite is used for chemical sterilisation of equipment. 

For low-risk devices the manufacturer may make a declaration of conformity with the essential requirements on the basis of a self-assessment, without any input from a Notified Body. In the case of Clas s I devices that are sterile or have a measuring function. Notified Body involvement is required, to provide assurance as to the effectiveness of the sterilisation process or the meteorological traceability of values as appropriate. 

Changes to an approved device that could affect its safety or effectiveness must be submitted to the FDA as a supplemental application. These include changes to the indications for use, changes to the labelling, packaging or sterilisation procedures. 

Pharmaceuticals for injection must be presented in a sterile form. Sterility may be achieved by filtration through 0.22 pm filters under aseptic conditions, or by steam, dry heat, radiation or gas sterilisation methods, which may be applied to packaged products. Irrespective of the method, the process must be validated and monitored to assure its effectiveness. As discussed in Chapter 2, this is an example of a process that cannot be assured by verification testing because of its destructive nature. 

Garrison, W.M. (1981). The radiation chemistry of amino acids, peptides and proteins in relation to the radiation sterilisation of high-protein foods. Radiat. Effects 54, 29-40. 

Cold sterilisation can be carried out with a mixture of 90% carbon dioxide and 10% ethylene oxide, the carbon dioxide has a stabilising effect on the ethylene oxide and reduces the risk of explosion. 

Figure 8.1. Biofilms are microbial communities that are made up of several species and often possess a distinct spatial structure. It has been found that living in a biofilm can offer significant protection to individuals, with sterilisation agents and even antibiotics being less potent against individuals if they are found in a biofilm. This is significant because it has been estimated that nearly three quarters of bacterial infections involve microbes that live in biofilm communities. Although there is a growing literature on the effects of NPs on biofilms, there is currently little knowledge of the production and metabolism of NPs in biofilms.

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