全文获取类型
收费全文 | 11193篇 |
免费 | 682篇 |
国内免费 | 85篇 |
专业分类
耳鼻咽喉 | 88篇 |
儿科学 | 156篇 |
妇产科学 | 161篇 |
基础医学 | 1355篇 |
口腔科学 | 206篇 |
临床医学 | 1112篇 |
内科学 | 3100篇 |
皮肤病学 | 150篇 |
神经病学 | 922篇 |
特种医学 | 376篇 |
外科学 | 1834篇 |
综合类 | 62篇 |
一般理论 | 1篇 |
预防医学 | 773篇 |
眼科学 | 87篇 |
药学 | 692篇 |
中国医学 | 20篇 |
肿瘤学 | 865篇 |
出版年
2024年 | 6篇 |
2023年 | 79篇 |
2022年 | 128篇 |
2021年 | 385篇 |
2020年 | 199篇 |
2019年 | 373篇 |
2018年 | 464篇 |
2017年 | 295篇 |
2016年 | 295篇 |
2015年 | 364篇 |
2014年 | 500篇 |
2013年 | 616篇 |
2012年 | 974篇 |
2011年 | 993篇 |
2010年 | 559篇 |
2009年 | 455篇 |
2008年 | 724篇 |
2007年 | 765篇 |
2006年 | 628篇 |
2005年 | 676篇 |
2004年 | 623篇 |
2003年 | 557篇 |
2002年 | 549篇 |
2001年 | 95篇 |
2000年 | 67篇 |
1999年 | 84篇 |
1998年 | 96篇 |
1997年 | 57篇 |
1996年 | 55篇 |
1995年 | 46篇 |
1994年 | 32篇 |
1993年 | 35篇 |
1992年 | 31篇 |
1991年 | 27篇 |
1990年 | 12篇 |
1989年 | 14篇 |
1988年 | 11篇 |
1987年 | 6篇 |
1986年 | 16篇 |
1985年 | 9篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1979年 | 5篇 |
1975年 | 4篇 |
1974年 | 5篇 |
1973年 | 3篇 |
1971年 | 5篇 |
1970年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
Matthias Y. Kellermann Gunter Wegener Marcus Elvert Marcos Yukio Yoshinaga Yu-Shih Lin Thomas Holler Xavier Prieto Mollar Katrin Knittel Kai-Uwe Hinrichs 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(47):19321-19326
The methane-rich, hydrothermally heated sediments of the Guaymas Basin are inhabited by thermophilic microorganisms, including anaerobic methane-oxidizing archaea (mainly ANME-1) and sulfate-reducing bacteria (e.g., HotSeep-1 cluster). We studied the microbial carbon flow in ANME-1/ HotSeep-1 enrichments in stable-isotope–probing experiments with and without methane. The relative incorporation of 13C from either dissolved inorganic carbon or methane into lipids revealed that methane-oxidizing archaea assimilated primarily inorganic carbon. This assimilation is strongly accelerated in the presence of methane. Experiments with simultaneous amendments of both 13C-labeled dissolved inorganic carbon and deuterated water provided further insights into production rates of individual lipids derived from members of the methane-oxidizing community as well as their carbon sources used for lipid biosynthesis. In the presence of methane, all prominent lipids carried a dual isotopic signal indicative of their origin from primarily autotrophic microbes. In the absence of methane, archaeal lipid production ceased and bacterial lipid production dropped by 90%; the lipids produced by the residual fraction of the metabolically active bacterial community predominantly carried a heterotrophic signal. Collectively our results strongly suggest that the studied ANME-1 archaea oxidize methane but assimilate inorganic carbon and should thus be classified as methane-oxidizing chemoorganoautotrophs. 相似文献
122.
123.
124.
125.
126.
127.
128.
129.
130.
Erlangga Yusuf MD PhD Xavier Jordan MD Martin Clauss MD Olivier Borens MD Mark Mäder MD PhD Andrej Trampuz MD 《Wound repair and regeneration》2013,21(5):677-681
No earlier study has investigated the microbiology of negative pressure wound therapy (NPWT) foam using a standardized manner. The purpose of this study is to investigate the bacterial load and microbiological dynamics in NPWT foam removed from chronic wounds (>3 months). To determine the bacterial load, a standardized size of the removed NPWT foam was sonicated. The resulting sonication fluid was cultured, and the colony‐forming units (CFU) of each species were enumerated. Sixty‐eight foams from 17 patients (mean age 63 years, 71% males) were investigated. In 65 (97%) foams, ≥ 1 and in 37 (54%) ≥2 bacterial types were found. The bacterial load remained high during NPWT treatment, ranging from 104 to 106 CFU/ml. In three patients (27%), additional type of bacteria was found in subsequent foam cultures. The mean bacterial count ± standard deviation was higher in polyvinyl alcohol foam (6.1 ± 0.5 CFU/ml) than in polyurethane (5.5 ± 0.8 CFU/ml) (p = 0.02). The mean of log of sum of CFU/ml in foam from 125 mmHg (5.5 ± 0.8) was lower than in foam from 100 mmHg pressure (5.9 ± 0.5) (p = 0.01). Concluding, bacterial load remains high in NPWT foam, and routine changing does not reduce the load. 相似文献