2 resultados para Heat shock experiment

em Memorial University Research Repository


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Heat shock factor 1 (Hsf1) is a protein known to be involved in both stress and developmental processes through the regulation of heat shock proteins. However, to date, no studies have been performed on examining its expression in the myometrium during pregnancy. During pregnancy, the uterus undergoes many structural and functional changes, and it also endures both mechanical and hormonal stresses. Therefore, the purpose of this thesis was to characterize the expression of Hsf1, and its associated factors in the uterus during pregnancy. Immunoblot analysis determined that Hsf1 protein expression was high early in gestation (day (d) 6) and then decreased significantly from mid gestation onwards (specifically when compared to d15, d17 and d22, p<0.05, n=5). Immunofluorescence analysis, demonstrated that Hsf1 was readily detectable in the myometrium but did not markedly change over gestation. Hsf1 was also localized mainly in the cytoplasm of myometrial cells, with some granular staining in the nucleus. Many related proteins of Hsf1 were also detectable in the myometrium, during pregnancy, such as PARP-1 and Hsf2. These results indicate that Hsf1 could play an important role early in gestation either to aid in myometrial cell proliferation or to upregulate expression of key genes necessary for subsequent myometrial differentiation.

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A heat loop suitable for the study of thermal fouling and its relationship to corrosion processes was designed, constructed and tested. The design adopted was an improvement over those used by such investigators as Hopkins and the Heat Transfer Research Institute in that very low levels of fouling could be detected accurately, the heat transfer surface could be readily removed for examination and the chemistry of the environment could be carefully monitored and controlled. In addition, an indirect method of electrical heating of the heat transfer surface was employed to eliminate magnetic and electric effects which result when direct resistance heating is employed to a test section. The testing of the loop was done using a 316 stainless steel test section and a suspension of ferric oxide and water in an attempt to duplicate the results obtained by Hopkins. Two types of thermal ·fouling resistance versus time curves were obtained . (i) Asymptotic type fouling curve, similar to the fouling behaviour described by Kern and Seaton and other investigators, was the most frequent type of fouling curve obtained. Thermal fouling occurred at a steadily decreasing rate before reaching a final asymptotic value. (ii) If an asymptotically fouled tube was cooled with rapid cir- ·culation for periods up to eight hours at zero heat flux, and heating restarted, fouling recommenced at a high linear rate. The fouling results obtained were observed to be similar and 1n agreement with the fouling behaviour reported previously by Hopkins and it was possible to duplicate quite closely the previous results . This supports the contention of Hopkins that the fouling results obtained were due to a crevice corrosion process and not an artifact of that heat loop which might have caused electrical and magnetic effects influencing the fouling. The effects of Reynolds number and heat flux on the asymptotic fouling resistance have been determined. A single experiment to study the effect of oxygen concentration has been carried out. The ferric oxide concentration for most of the fouling trials was standardized at 2400 ppM and the range of Reynolds number and heat flux for the study was 11000-29500 and 89-121 KW/M², respectively.