全文获取类型
收费全文 | 326篇 |
免费 | 47篇 |
专业分类
373篇 |
出版年
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 12篇 |
2016年 | 7篇 |
2015年 | 18篇 |
2014年 | 9篇 |
2013年 | 14篇 |
2012年 | 11篇 |
2011年 | 17篇 |
2010年 | 5篇 |
2009年 | 7篇 |
2008年 | 16篇 |
2007年 | 13篇 |
2006年 | 13篇 |
2005年 | 4篇 |
2004年 | 13篇 |
2003年 | 10篇 |
2002年 | 12篇 |
2001年 | 7篇 |
2000年 | 9篇 |
1999年 | 9篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1994年 | 4篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1989年 | 4篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1976年 | 10篇 |
1975年 | 6篇 |
1974年 | 11篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1971年 | 8篇 |
1970年 | 3篇 |
1969年 | 4篇 |
1967年 | 5篇 |
1966年 | 4篇 |
1955年 | 3篇 |
排序方式: 共有373条查询结果,搜索用时 15 毫秒
111.
Neuromuscular synapses in the cockroach extensor tibiae muscle 总被引:3,自引:0,他引:3
112.
113.
The functional consequences of luteinizing hormone/human chorionic gonadotropin signaling via neuronal luteinizing hormone/human chorionic gonadotropin receptors expressed throughout the brain remain unclear. A primary function of luteinizing hormone (LH) in the gonads is the stimulation of sex steroid production. As LH can cross the blood-brain barrier, present in cerebrospinal fluid and is expressed by neuronal cells, we tested whether LH might also modulate steroid synthesis in the brain. Treatment of differentiated rat primary hippocampal neurons and human M17 neuroblastoma cells with LH (100 mIU/mL) resulted in a twofold increase in pregnenolone secretion in both cell types, suggesting an increase in P450scc-mediated cleavage of cholesterol to pregnenolone and its secretion from neurons. To explore how LH might regulate the synthesis of pregnenolone, the precursor for steroid synthesis, we treated rat primary hippocampal neurons with LH (0, 10 and 100 mIU/mL) and measured changes in the expression of LH receptor and steroidogenic acute regulatory protein (StAR). LH induced a rapid (within 30 min) increase in the expression of StAR, but induced a dose-dependent decrease in LH receptor expression. Consistent with these results, the suppression of serum LH in young rats treated with leuprolide acetate for 4 months down-regulated StAR expression, but increased LH receptor expression in the brain. Taken together, these results indicate that LH induces neuronal pregnenolone production by modulating the expression of the LH receptor, increasing mitochondrial cholesterol transport and increasing P450scc-mediated cleavage of cholesterol for pregnenolone synthesis and secretion. 相似文献
114.
A chromosome 11q quantitative-trait locus influences change of blood-pressure measurements over time in Mexican Americans of the San Antonio Family Heart Study 总被引:1,自引:0,他引:1 下载免费PDF全文
115.
116.
117.
118.
Stephen R. Zins Christian D. S. Nelson Melissa S. Maginnis Rahul Banerjee Bethany A. O'Hara Walter J. Atwood 《Journal of virology》2014,88(2):948-960
Progressive multifocal leukoencephalopathy (PML) is a fatal disease with limited treatment options, both clinically and in the research pipeline. Potential therapies would target and neutralize its etiologic agent, JC polyomavirus (JCPyV). The innate immune response to JCPyV infection has not been studied, and little is known about the initial host response to polyomavirus infection. This study examined the ability of a human alpha defensin, HD5, to neutralize JCPyV infection in human fetal glial cells. We show that HD5, by binding to the virion, blocks infection. The JCPyV-HD5 complexes bind to and enter host cells but are reduced in their ability to reach the endoplasmic reticulum (ER), where virions are normally uncoated. Furthermore, HD5 binding to the virion stabilizes the capsid and prevents genome release. Our results show that HD5 neutralizes JCPyV infection at an early postentry step in the viral life cycle by stabilizing the viral capsid and disrupting JCPyV trafficking. This study provides a naturally occurring platform for developing antivirals to treat PML and also expands on the known capabilities of human defensins. 相似文献
119.
Hind Satti Megan M. McLaughlin Bethany Hedt-Gauthier Sidney S. Atwood David B. Omotayo Likhapha Ntlamelle Kwonjune J. Seung 《PloS one》2012,7(10)
Background
Although the importance of concurrent treatment for multidrug-resistant tuberculosis (MDR-TB) and HIV co-infection has been increasingly recognized, there have been few studies reporting outcomes of MDR-TB and HIV co-treatment. We report final outcomes of comprehensive, integrated MDR-TB and HIV treatment in Lesotho and examine factors associated with death or treatment failure.Methods
We reviewed clinical charts of all adult patients who initiated MDR-TB treatment in Lesotho between January 2008 and September 2009. We calculated hazard ratios (HR) and used multivariable Cox proportional hazards regression to identify predictors of poor outcomes.Results
Of 134 confirmed MDR-TB patients, 83 (62%) were cured or completed treatment, 46 (34%) died, 3 (2%) transferred, 1 (1%) defaulted, and 1 (1%) failed treatment. Treatment outcomes did not differ significantly by HIV status. Among the 94 (70%) patients with HIV co-infection, 53% were already on antiretroviral therapy (ART) before MDR-TB treatment initiation, and 43% started ART a median of 16 days after the start of the MDR-TB regimen. Among HIV co-infected patients who died, those who had not started ART before MDR-TB treatment had a shorter median time to death (80 days vs. 138 days, p = 0.065). In multivariable analysis, predictors of increased hazard of failure or death were low and severely low body mass index (HR 2.75, 95% confidence interval [CI] 1.27–5.93; HR 5.50, 95% CI 2.38–12.69), and a history of working in South Africa (HR 2.37, 95% CI 1.24–4.52).Conclusions
Favorable outcomes can be achieved in co-infected patients using a community-based treatment model when both MDR-TB and HIV disease are treated concurrently and treatment is initiated promptly. 相似文献120.
Direct correlation between sialic acid binding and infection of cells by two human polyomaviruses (JC virus and BK virus) 总被引:1,自引:1,他引:0
For the human polyomaviruses JC virus (JCV) and BK virus (BKV), the first step to a successful infection involves binding to sialic acid moieties located on the surfaces of host cells. By stripping and then reconstituting specific sialic acid linkages on host cells, we show that JCV uses both α(2,3)-linked and α(2,6)-linked sialic acids on N-linked glycoproteins to infect cells. For both JCV and BKV, the sialic acid linkages required for cell surface binding directly correlate with the linkages required for infection. In addition to sialic acid linkage data, these data suggest that the third sugar from the carbohydrate chain terminus is important for virus binding and infection. 相似文献