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排序方式: 共有10000条查询结果,搜索用时 281 毫秒
981.
Susan Morrison Grace John-Stewart John J. Egessa Sezi Mubezi Sylvia Kusemererwa Dennis K. Bii Nulu Bulya Francis Mugume James D. Campbell Jonathan Wangisi Elizabeth A. Bukusi Connie Celum Jared M. Baeten Partners PrEP Study Team 《PloS one》2015,10(10)
During an HIV-1 prevention clinical trial in East Africa, we observed 16 cases of primary HIV-1 infection in women coincident with pregnancy or breastfeeding. Nine of eleven pregnant women initiated rapid combination antiretroviral therapy (ART), despite having CD4 counts exceeding national criteria for ART initiation; breastfeeding women initiated ART or replacement feeding. Rapid ART initiation during primary HIV-1 infection during pregnancy and breastfeeding is feasible in this setting. 相似文献
982.
A Gram-positive Rhodococcus erythropolis strain S1 was shown to assimilate aromatic amino acids such as L-phenylalanine, L-tyrosine, L-tryptophan, D-phenylalanine, D-tyrosine and D-tryptophan, which were utilized not only as the sole carbon source but also as a suitable nitrogen source. The highest growth on these aromatic amino acids occurred at a temperature of 30°C. L-Phenylalanine, L-tyrosine and L-tryptophan degradative pathways would appear to be independent, and to be induced alternatively. The strain S1 also showed the ability to assimilate peptides which consisted of only L-phenylalanine and L-tyrosine. 相似文献
983.
J. P. Barkham 《Biodiversity and Conservation》1995,4(8):857-868
Despite the growth in awareness and practical action to maintain biodiversity, environmental degradation and ecosystem destruction has continued at a high rate over the last 20 years. The roots of this lie in the predominant international economic order, underpinned by lifestyle demands for increased material consumption. Net flow of wealth from South (less developed) to North (more developed) nations has exacerbated a spiral of increased poverty and environmental degradation in the former. Global environmental conservation depends upon a radical change of direction with the principle of equity as the starting point. Notwithstanding the importance of continuing to add to local and small-scale conservation achievements, the prospect of radical change happening seems small, despite it being in the long-term self-interest of the North. The concept of equity is, apparently, unacceptable to Northern electorates. 相似文献
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987.
The interaction of a plasma in the accelerating gap of an open discharge with a strong external electric field and with the cathode surface has been investigated theoretically and experimentally. In a pulsed nanosecond discharge, the ion inertia and plasma screening of the electric field cause a fast growth of the electric field E in the cathode region and a decrease in the length of the latter. Along with a reduction of the electron multiplication factor at high electric fields, this leads to a substantial decrease in the ion flux toward the cathode, which allows one to develop highly efficient open-discharge light sources with a long lifetime and low cathode sputtering. In this respect, continuous and quasi-continuous discharges are less advantageous because of the smaller increase in the electric field in the cathode region. The Townsend coefficients of charge multiplication and electron emission at high electric fields typical of open discharges have been measured for the first time. Fast ions and atoms extracted from the plasma of the accelerating gap significantly affect the cathode emission properties. In particular, photoemission is enhanced by more than one order of magnitude and becomes the main mechanism for electron generation. This also increases the efficiency and lifetime of open-discharge light sources. 相似文献
988.
Y Midorikawa H Hibasami P Gasaluck H Yoshimura A Masuji K Nakashima M Imai 《The Journal of applied bacteriology》1991,70(4):291-293
Metabolic and antiproliferative effects of methylglyoxal bis(butylamidinohydrazone) (MGBB) and methylglyoxal bis(cyclopentylamidinohydrazone) (MGBCP), inhibitors for polyamine biosynthetic pathway, on Escherichia coli, Shigella sonnei, Aeromonas sobria, Aeromonas hydrophila and Vibrio cholerae were investigated. MGBB at the concentration of 100 mumol/l depleted intracellular putrescine and spermidine concentrations of E. coli to 25 and 20% of the controls, respectively, while MGBCP depressed their concentrations to 38 and 24%, respectively. In these polyamine-depleted E. coli cells the syntheses of RNA, DNA and protein decreased to 13, 54 and 29% of the control, respectively, with MGBB and to 23, 71 and 55%, respectively, with MGBCP. The minimum inhibitory concentrations (MIC) of MGBB for the growth of A. sobria, E. coli, A. hydrophila, V. cholerae and Sh. sonnei were estimated to be 50, 160, 240, 285 and 320 mumol/l, respectively, whereas those of MGBCP were slightly higher for respective bacteria. 相似文献
989.
Recent reports suggest that prostaglandins, rather than cAMP, play a major role in mediating cholera toxin-induced water and electrolyte secretion from rabbit intestinal loops. We examined the role of prostaglandins in mediating toxin-induced pancreatic and gastric exocrine secretion. In these tissues, indomethacin, a potent inhibitor of prostaglandin synthesis, did not alter the stimulatory effects of cholera toxin on increases in cellular cAMP or enzyme secretion. Moreover, the addition of cholera toxin did not alter prostaglandin E2 release from either tissue. In contrast to their effects in rabbit intestinal loops, prostaglandins do not regulate cholera toxin-induced enzyme secretion from the guinea pig pancreas or stomach. 相似文献
990.