全文获取类型
收费全文 | 222篇 |
免费 | 24篇 |
出版年
2022年 | 3篇 |
2021年 | 2篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 10篇 |
2014年 | 12篇 |
2013年 | 9篇 |
2012年 | 9篇 |
2011年 | 14篇 |
2010年 | 11篇 |
2009年 | 10篇 |
2008年 | 5篇 |
2007年 | 7篇 |
2006年 | 19篇 |
2005年 | 9篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1996年 | 5篇 |
1994年 | 3篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 4篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1963年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1960年 | 2篇 |
1957年 | 1篇 |
1953年 | 1篇 |
1946年 | 2篇 |
1942年 | 1篇 |
1918年 | 1篇 |
排序方式: 共有246条查询结果,搜索用时 171 毫秒
21.
Multilocus Sequence Typing Supports the Hypothesis that Cow- and Human-Associated Salmonella Isolates Represent Distinct and Overlapping Populations 下载免费PDF全文
S. D. Alcaine Y. Soyer L. D. Warnick W.-L. Su S. Sukhnanand J. Richards E. D. Fortes P. McDonough T. P. Root N. B. Dumas Y. Grhn M. Wiedmann 《Applied microbiology》2006,72(12):7575-7585
A collection of 179 human and 156 bovine clinical Salmonella isolates obtained from across New York state over the course of 1 year was characterized using serotyping and a multilocus sequence typing (MLST) scheme based on the sequencing of three genes (fimA, manB, and mdh). The 335 isolates were differentiated into 52 serotypes and 72 sequence types (STs). Analyses of bovine isolates collected on different farms over time indicated that specific subtypes can persist over time on a given farm; in particular, a number of farms showed evidence for the persistence of a specific Salmonella enterica serotype Newport sequence type. Serotypes and STs were not randomly distributed among human and bovine isolates, and selected serotypes and STs were associated exclusively with either human or bovine sources. A number of common STs were geographically widespread. For example, ST6, which includes isolates representing serotype Typhimurium as well as the emerging serotype 4,5,12:i:-, was found among human and bovine isolates in a number of counties in New York state. Phylogenetic analyses supported the possibility that serotype 4,5,12:i:- is closely related to Salmonella serotype Typhimurium. Salmonella serotype Newport was found to represent two distinct evolutionary lineages that differ in their frequencies among human and bovine isolates. A number of Salmonella isolates carried two copies of manB (33 isolates) or showed small deletion events in fimA (nine isolates); these duplication and deletion events may provide mechanisms for the rapid diversification of Salmonella surface molecules. We conclude that the combined use of an economical three-gene MLST scheme and serotyping can provide considerable new insights into the evolution and transmission of Salmonella. 相似文献
22.
The phenotypic variance-covariance matrix (P) describes the multivariate distribution of a population in phenotypic space, providing direct insight into the appropriateness of measured traits within the context of multicollinearity (i.e., do they describe any significant variance that is independent of other traits), and whether trait covariances restrict the combinations of phenotypes available to selection. Given the importance of P, it is therefore surprising that phenotypic covariances are seldom jointly analyzed and that the dimensionality of P has rarely been investigated in a rigorous statistical framework. Here, we used a repeated measures approach to quantify P separately for populations of four cricket species using seven acoustic signaling traits thought to enhance mate attraction. P was of full or almost full dimensionality in all four species, indicating that all traits conveyed some information that was independent of the other traits, and that phenotypic trait covariances do not constrain the combinations of signaling traits available to selection. P also differed significantly among species, although the dominant axis of phenotypic variation (p(max)) was largely shared among three of the species (Acheta domesticus, Gryllus assimilis, G. texensis), but different in the fourth (G. veletis). In G. veletis and A. domesticus, but not G. assimilis and G. texensis, p(max) was correlated with body size, while p(max) was not correlated with residual mass (a condition measure) in any of the species. This study reveals the importance of jointly analyzing phenotypic traits. 相似文献
23.
A major challenge of medical anthropology is to assess howbiomedicine, as a vaguely-defined set of diverse texts,technologies, and practitioners, shapes the experience of selfand body. Through narrative analyses of in-depth, semi-structuredinterviews with 158 pregnant women in southern California, thispaper explores how the culture of biomedicine, encounteredformally at prenatal care check-ups and informally throughdiverse media, influences pregnant women's perceptions ofappropriate prenatal behavior. In the spirit of recent socialscientific work that draws on and challenges Foucauldian insightsto explore social relations in medicine, we posit a spectrum ofcompliance and resistance to biomedical norms upon whichindividual prenatal practices are assessed. We suggest thatpregnancy is, above all, characterized by a split subjectivity inwhich women straddle the authoritative and the subjugated, theobjective and the subjective, and the haptic as well as theoptic, in telling and often strategic ways. In so doing, weidentify the intersection between the disciplinary practices ofbiomedicine and the practices of pregnant women as a means offurnishing more fruitful insights into the oft-used term ``power'and its roles in constituting social relations in medicine. 相似文献
24.
The oviduct from laying quail were used to investigate mechanisms of trace mineral secretion and the possible role of metallothionein in this process. Secretion of zinc occurred maximally at pH 5.4, which is close to the normal pH of the oviduct. Secretion occurred to a much greater extent in the isthmus and shell gland than in the magnum, the major protein-secretory section of the oviduct. Intraperitoneal administration of cadmium resulted in a marked reduction in Zn secretion from the oviduct of laying quail. This effect could not be correlated with metallothionein since metallothionein could not be detected in any section of the oviduct in control or Cd-induced quail. Small-molecular-weight metal-binding ligands were present in the isthmus and shell gland, which may play a role in trace mineral mobilization. Histological evaluation by light and elelctron microscopy show that Zn is transported from the smooth muscle cells through the connective tissue matrix in the extracellular space to the epithelial goblet cells. Presumably, Zn and other trace minerals are secreted from the secretory goblet cells into the egg. 相似文献
25.
26.
Five patients seen during a two-month period who developed untoward systemic reactions following high dose intravenous administration of nafcillin are described. Recovery was complete upon discontinuation of the drug. The clustering of these cases and the high incidence (5 of 5) of side effects are highly unusual, and suggest that the frequency of nafcillin reactions might be higher than previously suspected. 相似文献
27.
28.
29.
Although it is an intrinsic part of all medical practice forensic medicine often is either unrecognized as such or is consciously or subconsciously evaded. The failure to apply some rather basic and simple forensic principles that only the physician is capable of doing may result in problems to the patient ranging from frustration to near catastrophe. For physicians who are reasonably well equipped to understand the legal system, the successful conclusion of a legal case, including, sometimes, an appearance in court, can be stimulating and interesting. 相似文献
30.