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排序方式: 共有190条查询结果,搜索用时 15 毫秒
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Improving cognitive ability in chronically deprived children 总被引:3,自引:0,他引:3
Beginning at different ages in their preschool years, groups of chronically undernourished children from Colombian families of low socioeconomic status participated in a program of treatment combining nutritional, health care, and educational features. By school age the gap in cognitive ability between the treated children and a group of privileged children in the same city had narrowed, the effect being greater the younger the children were when they entered the treatment program. The gains were still evident at the end of the first grade in primary school, a year after the experiment had ended. 相似文献
184.
Nguyen D Joshi-Datar A Lepine F Bauerle E Olakanmi O Beer K McKay G Siehnel R Schafhauser J Wang Y Britigan BE Singh PK 《Science (New York, N.Y.)》2011,334(6058):982-986
Bacteria become highly tolerant to antibiotics when nutrients are limited. The inactivity of antibiotic targets caused by starvation-induced growth arrest is thought to be a key mechanism producing tolerance. Here we show that the antibiotic tolerance of nutrient-limited and biofilm Pseudomonas aeruginosa is mediated by active responses to starvation, rather than by the passive effects of growth arrest. The protective mechanism is controlled by the starvation-signaling stringent response (SR), and our experiments link SR-mediated tolerance to reduced levels of oxidant stress in bacterial cells. Furthermore, inactivating this protective mechanism sensitized biofilms by several orders of magnitude to four different classes of antibiotics and markedly enhanced the efficacy of antibiotic treatment in experimental infections. 相似文献
185.
Epitopes recognized by human T cells map within the conserved part of the GP190 of P. falciparum 总被引:10,自引:0,他引:10
A Crisanti H M Müller C Hilbich F Sinigaglia H Matile M McKay J Scaife K Beyreuther H Bujard 《Science (New York, N.Y.)》1988,240(4857):1324-1326
In a study aimed at developing a vaccine against the asexual blood stages of Plasmodium falciparum, two T cell epitopes were identified within a nonpolymorphic region of gp190 of Plasmodium falciparum merozoites. The two epitopes, which were revealed by deletion analysis, stimulated human T cell clones. Peptides containing sequences of the epitopes stimulated the cloned T cells and peripheral blood mononuclear cells (PBMC) from malaria-infected individuals. Moreover, the T cell clones responded to 11 different Plasmodium falciparum isolates in culture, showing that the epitopes are recognized in native parasites. 相似文献
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M‐J Sánchez‐Calabuig C López‐Fernández E Martínez‐Nevado JF Pérez‐Gutiérrez J de la Fuente SD Johnston D Blyde K Harrison J Gosálvez 《Reproduction in domestic animals》2014,49(5):761-768
Over the last two decades, there have been significant advances in the use of assisted reproductive technology for genetic and reproductive management of captive dolphin populations, including evaluation of sperm DNA quality. This study validated a customized sperm chromatin dispersion test (SCDt) for the bottlenose dolphin (Tursiops truncatus) as a means of assessing sperm DNA damage both in the field and in the laboratory. After performing the SCDt, two different sperm morphotypes were identified: (i) sperm with fragmented DNA showed large haloes of dispersed DNA fragments emerging from a compact sperm nucleoid core and (ii) sperm containing non‐fragmented DNA displayed small compact haloes surrounded by a dense core of non‐dispersed DNA and protein complex. Estimates of sperm DNA fragmentation by means of SCDt were directly comparable to results obtained following a two‐tailed comet assay and showed a significant degree of correlation (r = 0.961; p < 0.001). This investigation also revealed that the SCDt, with minor modifications to the standard protocol, can be successfully conducted in the field using a LED florescence microscopy obtaining a high correlation (r = 0.993; p = 0.01) between the data obtained in the laboratory and in the field. 相似文献
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McKay AR 《Science (New York, N.Y.)》1968,162(3850):270
Pilots' reports of clear-air turbulence correlate inferentially with sporadic E activity observed by backscatter radar. A cursory survey was made of 19 reports of turbulence between 1 and 20 August 1964 over the western United States; all but three correlate with sporadic E patches. 相似文献
190.