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101.
HY Song CH Régnier CJ Kirschning DV Goeddel M Rothe 《Canadian Metallurgical Quarterly》1997,94(18):9792-9796
102.
A gene encoding a bifunctional homodimeric dihydrofolate reductase-
thymidylate synthase (DHFR-TS) was constructed by destroying the stop codon
of Escherichia coli dihydrofolate reductase (DHFR) and joining the coding
sequences of the monofunctional enzymes by a five amino acid linker. The
protein was designed to mimic features of active site proximity and
electrostatics in the protozoan DHFR-TSs which are believed to be important
in channeling of the DHFR substrate, H2folate, to TS. The genetically
engineered catalytically active homodimeric bifunctional DHFR-TS was
expressed, purified and characterized. The component activities of the
purified bifunctional enzyme had kinetic properties similar to those of the
monofunctional TS and DHFR, but unlike the authentic bifunctional enzymes
from protozoa this enzyme did not kinetically channel dihydrofolate from
DHFR to TS.
相似文献
103.
Recent evidence suggests that conservative elites' claims of a liberal media are having an impact upon public perceptions of news coverage. With this in mind, we examined two related questions in the context of the 1988, 1992, and 1996 presidential elections. First, what factors may be prompting conservative elites to make allegations of liberal media bias? Second, what factors may influence when news media report these criticisms during presidential campaigns? Findings suggest that these criticisms of news media are at least partly strategic and reflect a dynamic relationship between political elites and journalists during a presidential campaign. 相似文献
104.
105.
This study compared the effects of undiluted and 8% ethanol administered orally on gastrointestinal antioxidant components of male and female rats. Eight percent ethanol increased the activities of duodenal glutathione peroxide (29% in males, 14% in females) and superoxide dismutase in female gastric (24%) and male duodenal (15%) mucosa. This dose of ethanol also increased the glutathione content of gastric mucosa (12% in males, 13% in females). Undiluted ethanol decreased glutathione levels in gastric mucosa (22% in males, 11% in females) and increased glutathione peroxide activity in gastric mucosa (14% in males, 9% in females). Undiluted alcohol also produced decreases in the activity of glutathione reductase in stomach (14% in males, 9% in females) and duodenum (16% in males, 12% in females). Undiluted ethanol caused mucosal damage in the body of the stomach in both genders, accompanied by an increase in luminal pH and fluid accumulation in the stomach; these changes were absent in rats given 8% ethanol. The increase in gastrointestinal antioxidant capacity associated with the administration of 8% ethanol may be a factor in the reported cytoprotective effect of lower doses of ethanol. 相似文献
106.
107.
The present investigation was conducted to study the effect of selected processing and storage methods on the concentration of ascorbic acid and beta-carotene in Bathua and fenugreek leaves. Methods included storage of leaves with or without polythene bags for 24 and 48 h in a refrigerator at 5 degrees C; at 30 degrees C in polythene bags; drying (sun and oven); blanching (5, 10, 15 min); open pan and pressure cooking. Ascorbic acid content of fresh leaves was 220.97 to 377.65 mg and beta-carotene content was 19.00 to 24.64 mg/100 g, DW. The percent loss of ascorbic acid ranged from 2.03 to 8.77 and 45.15 to 66.9 while lower losses (0.0 to 1.75 and 1.63 to 2.84) of beta-carotene were observed in leaves stored in the refrigerator and at 30 degrees C, respectively. A markedly greater reduction in ascorbic acid and beta-carotene was observed in dried, blanched and cooked leaves. The study data suggest that storage of leaves in refrigeration, drying in oven, blanching for a short time and cooking in a pressure cooker results in better retention of these two vitamins. 相似文献
108.
LC Lastoria DV Opromolla RN Fleury F Habermann PR Curi 《Canadian Metallurgical Quarterly》1998,66(2):190-200
The authors studied the Mitsuda reaction in 37 leprosy patients (18 reactional tuberculoid, 19 reactional borderline cases) and compared the results with clinical findings, histopathology and bacilloscopy. Evaluation of the Mitsuda reaction was carried out on days 30, 60, 90 and 120. Most of the reactional tuberculoid patients showed a Mitsuda reaction of +3 in opposition to the reactional borderline patients who showed only +. Bacilloscopic analysis revealed that in 75% of the reactional tuberculoid cases there were rare or no bacilli; bacilli were present in 95% of the reactional borderline cases. The authors conclude that reactional tuberculoid cases have a greater ability to clear bacilli than reactional borderline cases, and that the Mitsuda reaction is a useful tool for the differentiation between these two types of leprosy. 相似文献
109.
110.