全文获取类型
收费全文 | 4498篇 |
免费 | 377篇 |
国内免费 | 1篇 |
出版年
2023年 | 12篇 |
2022年 | 11篇 |
2021年 | 65篇 |
2020年 | 45篇 |
2019年 | 71篇 |
2018年 | 75篇 |
2017年 | 81篇 |
2016年 | 121篇 |
2015年 | 190篇 |
2014年 | 234篇 |
2013年 | 273篇 |
2012年 | 336篇 |
2011年 | 370篇 |
2010年 | 201篇 |
2009年 | 222篇 |
2008年 | 268篇 |
2007年 | 290篇 |
2006年 | 250篇 |
2005年 | 292篇 |
2004年 | 231篇 |
2003年 | 270篇 |
2002年 | 237篇 |
2001年 | 60篇 |
2000年 | 32篇 |
1999年 | 46篇 |
1998年 | 59篇 |
1997年 | 50篇 |
1996年 | 41篇 |
1995年 | 58篇 |
1994年 | 37篇 |
1993年 | 43篇 |
1992年 | 27篇 |
1991年 | 30篇 |
1990年 | 30篇 |
1989年 | 31篇 |
1988年 | 27篇 |
1987年 | 11篇 |
1986年 | 18篇 |
1985年 | 10篇 |
1984年 | 12篇 |
1982年 | 15篇 |
1981年 | 11篇 |
1980年 | 12篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1973年 | 7篇 |
1972年 | 5篇 |
1971年 | 5篇 |
1970年 | 7篇 |
排序方式: 共有4876条查询结果,搜索用时 15 毫秒
1.
2.
Cerebral edema is a common complication following moderate and severe traumatic brain injury (TBI), and a significant risk factor for development of neuronal death and deterioration of neurological outcome. To this date, medical approaches that effectively alleviate cerebral edema and neuronal death after TBI are not available. Glucagon-like peptide-1 (GLP-1) has anti-inflammatory properties on cerebral endothelium and exerts neuroprotective effects. Here, we investigated the effects of GLP-1 on secondary injury after moderate and severe TBI. Male Sprague Dawley rats were subjected either to TBI by Controlled Cortical Impact (CCI) or sham surgery. After surgery, vehicle or a GLP-1 analogue, Liraglutide, were administered subcutaneously twice daily for two days. Treatment with Liraglutide (200 μg/kg) significantly reduced cerebral edema in pericontusional regions and improved sensorimotor function 48 hours after CCI. The integrity of the blood-brain barrier was markedly preserved in Liraglutide treated animals, as determined by cerebral extravasation of Evans blue conjugated albumin. Furthermore, Liraglutide reduced cortical tissue loss, but did not affect tissue loss and delayed neuronal death in the thalamus on day 7 post injury. Together, our data suggest that the GLP-1 pathway might be a promising target in the therapy of cerebral edema and cortical neuronal injury after moderate and severe TBI. 相似文献
3.
Maximilian Schmid Bianca Dufner Julius Dürk Konstanze Bedal Kristina Stricker Lukas Ali Prokoph Christoph Koch Anja K. Wege Henner Zirpel Ger van Zandbergen Rupert Ecker Bogdan Boghiu Uwe Ritter 《PloS one》2015,10(10)
Characterization of host-pathogen interactions is a fundamental approach in microbiological and immunological oriented disciplines. It is commonly accepted that host cells start to change their phenotype after engulfing pathogens. Techniques such as real time PCR or ELISA were used to characterize the genes encoding proteins that are associated either with pathogen elimination or immune escape mechanisms. Most of such studies were performed in vitro using primary host cells or cell lines. Consequently, the data generated with such approaches reflect the global RNA expression or protein amount recovered from all cells in culture. This is justified when all host cells harbor an equal amount of pathogens under experimental conditions. However, the uptake of pathogens by phagocytic cells is not synchronized. Consequently, there are host cells incorporating different amounts of pathogens that might result in distinct pathogen-induced protein biosynthesis. Therefore, we established a technique able to detect and quantify the number of pathogens in the corresponding host cells using immunofluorescence-based high throughput analysis. Paired with multicolor staining of molecules of interest it is now possible to analyze the infection profile of host cell populations and the corresponding phenotype of the host cells as a result of parasite load. 相似文献
4.
5.
The ultimatum bargaining game (UBG), a widely used method in experimental economics, clearly demonstrates that motives other than pure monetary reward play a role in human economic decision making. In this study, we explore the behaviour and physiological reactions of both responders and proposers in an ultimatum bargaining game using heart rate variability (HRV), a small and nonintrusive technology that allows observation of both sides of an interaction in a normal experimental economics laboratory environment. We find that low offers by a proposer cause signs of mental stress in both the proposer and the responder; that is, both exhibit high ratios of low to high frequency activity in the HRV spectrum. 相似文献
6.
Phosphorylation of solubilized and purified high-affinity (Ca2+ + Mg2+)-ATPase (ATP phosphohydrolase, EC 3.6.1.3) of human erythrocyte membranes shows no dependence on cyclic AMP concentration in the range 0.1–1000 μM.Ca2+-dependent phosphoprotein is sensitive to hydroxylamine and molybdate treatment. The phosphate linkage shows maximum stability at low pH values, which is progressively lost as the pH rises, with a shoulder around pH 6. SDS gel electrophoresis of the phosphorylated protein yields a peak which shows relative mobility corresponding to a molecular weight of 145 000 and sensitivity to MgATP-chase and hydroxylamine treatment. This indicates that the phosphoprotein represents the phosphorylated intermediate of the high-affinity (Ca2+ + Mg2+)-ATPase of human erythrocyte membranes. 相似文献
7.
8.
9.
Several products derived from processed maca hypocotyls (Lepidium peruvianum Chacón, previously known asL. meyenii Walp.) were surveyed for glucosinolate content and quantified by HPLC analysis. These included pills, capsules, flour, liquor, tonic and mayonnaise. Different plant organs such as fresh hypocotyls and leaves, seeds, dry hypocotyls, and sprouts were also included in the survey. The most abundant glucosinolates detected in fresh and dry hypocotyls and leaves were the aromatic glucosinolates, benzylglucosinolate (glucotropaeolin) and p-methoxybenzylglucosinolate. Maca seeds and sprouts differed in profile from hypocotyls and leaves due to the modification of benzylglucosinolate. No glucosinolates were detected in liquor and tonic, while mayonnaise had only trace amounts of those glucosinolates. It had instead allylglucosinolate (sinigrin), which is an aliphatic glucosinolate. The pills, capsules and flour had the same glucosinolates as those observed in hypocotyls, but in variable amounts. The richest sources of glucosinolates were seeds, fresh hypocotyls and sprouts, in that order. 相似文献
10.