Irradiation pretreatment

Effect of Thermal and Electron Irradiation Pretreatments, Tappi 1965, 48(6), 367. 

The enhancement of nucleation and adhesion of diamond films has been achieved on Cu, stainless steel and Si using a pulsed laser irradiation pretreatment, followed by HFCVD.t l A thin buffer layer of a-C, WC or cBN was first deposited on the substrates by pulsed laser evaporation, followed by pulsed laser irradiation. For the Cu substrates, diamond nucleation densities on the a-C overlayer and WC (or cBN) buffer layer were... 

Deng Q, Chen Y, Sun W. Preparation of polymer brushes from poly(vinylidene fluoride) surfaces by UV irradiation pretreatment. Surf Rev Lett 2007 14(l) 23 -30. 

A number of studies have shown that vitamins moderate the induction of chromosomal aberrations by radiation. Vitamins C and E given orally to mice either 2 h before, immediately after, or 2 h after 1 Gy (100 rad) of y-ray TBI significantly reduce the frequencies of micronuclei and chromosomal aberrations in BM cells. Vitamin E is the more effective (95). Administration of vitamins C and E within 5 min of irradiation is as effective as pretreatment. Protection by vitamin C has also been shown in humans. Whereas chronic treatment of rats using vitamin C (100 or 300 mg/(kg/d)) for six months prior to TBI protects against chromosomal aberrations, vitamin E is not radioprotective in this setting (96). 

The decomposition of KMn04 is sensitive to pre-irradiation [899] by UV [396], X-rays, 7-rays, protons and neutrons. The effects of such pretreatment, which increase with dosage, are to reduce the induction period... 

The examples that are treated below are those sequences where all steps - except the last — are preparations for a color or fluorescence derivatization reaction which is carried out in the last step, i. e. they can be regarded as a sort of selective in situ pretreatment for a final detection reaction. Such reaction sequences are frequently necessary because all the reagents cannot be mixed together in a single solvent, or because it is necessary to dry, heat or irradiate with UV light between the individual reaction steps. The detection of aromatics by the reaction sequence nitration — reduction — diazotization - couple to form an azo dye is an example of this type (Fig 21). 

In another experiment, a new film was pretreated by bubbling H2 at 1 atm and 300 K through the solution for 0.5 hr prior to the N2 treatment described above. The activity of this film is shown in Fig. 2, dashed curve. It is closer to (2) than (1), and the induction time is relatively short. This indicates that, during the initial stages of irradiation with a fresh film, the activity is enhanced by some process involving hydrogen. 

The apphed pretreatment techniques were digestion with a combination of acids in the pressurized or atmospheric mode, programmed dry ashing, microwave digestion and irradiation with thermal neutrons. The analytical methods of final determination, at least four different for each element, covered all modern plasma techniques, various AAS modes, voltammetry, instrumental and radiochemical neutron activation analysis and isotope dilution MS. Each participating laboratory was requested to make a minimum of five independent rephcate determinations of each element on at least two different bottles on different days. Moreover, a series of different steps was undertaken in order to ensure that no substantial systematic errors were left undetected. 

Male infertility may result from cancer surgery, radiotherapy, hormonal imbalances, or damage of germinal stem cells. Testicular damage from radiotherapy depends on the treatment field, total dose, and fractionation schedule. Depending on the radiation, sperm counts may return to pretreatment levels in 10 to 24 months after therapy or maybe permanent in 80% of men after total-body irradiation for transplant. 

After a few minutes irradiation with a high pressure mercury lamp at about 50 C, a rather complete cover of grafted acrylic acid, acrylamide and other vinyl monomers could be obtained. In later experiments a continuous grafting method has been developed where a tape or a fiber bundle after suitable pretreatment is grafted by UV irradiation for a few seconds. Homopolymer formed is removed by washing and grafted polymer analyzed by dye absorption, IR reflection and ESCA spectroscopy. 

Since the intercalibration samples had been ultraviolet-irradiated, the majority of participants in this exercise preferred to analyse the samples without any pretreatment. Ten did, however, employ oxidising pretreatment, and with three exceptions the results suggest that this approach should be taken with great caution. 

Sipos et al. [789] have described a procedure for the simultaneous determination of copper and mercury in seawater down to the ng/1 range using differential pulse ASV at a gold electrode. Pretreatment is necessary, and comprises UV irradiation to release the trace metal bound to dissolved organic matter. 

Fig. 11. (a) Capacitance transient spectra from Co-60 - irradiated, n-type Si samples, one of which had been pretreated in an H plasma. Note the reduced defect state density in this sample, (b) Concentration profile of the O-V centers induced in these samples. There is a reduced defect concentration only in the region in which atomic hydrogen was incorporated. 

The application of flavonoids for the treatment of various diseases associated with free radical overproduction is considered in Chapter 29. However, it seems useful to discuss here some studies describing the activity of flavonoids under certain pathophysiological conditions. Oral pretreatment with rutin of rats, in which gastric lesions were induced by the administration of 100% ethanol, resulted in the reduction of the area of gastric lesions [157]. Rutin was found to be an effective inhibitor of TBAR products in the gastric mucosa induced by 50%i ethanol [158]. Rutin and quercetin were active in the reduction of azoxymethanol-induced colonic neoplasma and focal area of dysplasia in the mice [159], Chemopreventive effects of quercetin and rutin were also shown in normal and azoxymethane-treated mouse colon [160]. Flavonoids exhibited radioprotective effect on 7-ray irradiated mice [161], which was correlated with their antioxidative activity. Dietary flavones and flavonols protected against the toxicity of the environmental contaminant dioxin [162], Rutin inhibited ovariectomy-induced osteopenia in rats [163],... 

UVC Lacquer and Test. A white epoxy-acrylate lacquer was applied on all nickel plated sheets with different pretreatments to a thickness of 16 ym and was cured by irradiation with four 10-kW ultraviolet lamps for about 1.2 sec. 

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