全文获取类型
收费全文 | 34750篇 |
免费 | 3649篇 |
国内免费 | 2499篇 |
学科分类
医药卫生 | 40898篇 |
出版年
2024年 | 108篇 |
2023年 | 644篇 |
2022年 | 1164篇 |
2021年 | 2142篇 |
2020年 | 1508篇 |
2019年 | 1257篇 |
2018年 | 1239篇 |
2017年 | 1181篇 |
2016年 | 1070篇 |
2015年 | 1610篇 |
2014年 | 2015篇 |
2013年 | 1813篇 |
2012年 | 2566篇 |
2011年 | 2870篇 |
2010年 | 1781篇 |
2009年 | 1418篇 |
2008年 | 1761篇 |
2007年 | 1876篇 |
2006年 | 1745篇 |
2005年 | 1638篇 |
2004年 | 1171篇 |
2003年 | 1130篇 |
2002年 | 985篇 |
2001年 | 804篇 |
2000年 | 771篇 |
1999年 | 781篇 |
1998年 | 452篇 |
1997年 | 473篇 |
1996年 | 358篇 |
1995年 | 352篇 |
1994年 | 335篇 |
1993年 | 180篇 |
1992年 | 228篇 |
1991年 | 227篇 |
1990年 | 237篇 |
1989年 | 182篇 |
1988年 | 153篇 |
1987年 | 117篇 |
1986年 | 121篇 |
1985年 | 93篇 |
1984年 | 70篇 |
1983年 | 39篇 |
1982年 | 27篇 |
1981年 | 22篇 |
1979年 | 20篇 |
1977年 | 16篇 |
1975年 | 14篇 |
1974年 | 19篇 |
1972年 | 13篇 |
1969年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
991.
992.
993.
994.
D.Y. Xia W. Li H.R. Qian S. Yao J.G. Liu X.K. Qi 《Brazilian journal of medical and biological research》2013,46(7):580-588
Sublethal ischemic preconditioning (IPC) is a powerful inducer of ischemic brain
tolerance. However, its underlying mechanisms are still not well understood. In
this study, we chose four different IPC paradigms, namely 5 min (5 min
duration), 5×5 min (5 min duration, 2 episodes, 15-min interval), 5×5×5 min (5
min duration, 3 episodes, 15-min intervals), and 15 min (15 min duration), and
demonstrated that three episodes of 5 min IPC activated autophagy to the
greatest extent 24 h after IPC, as evidenced by Beclin expression and LC3-I/II
conversion. Autophagic activation was mediated by the tuberous sclerosis type 1
(TSC1)-mTor signal pathway as IPC increased TSC1 but decreased mTor
phosphorylation. Terminal deoxynucleotidyl transferase dUTP nick end labeling
(TUNEL) and hematoxylin and eosin staining confirmed that IPC protected against
cerebral ischemic/reperfusion (I/R) injury. Critically, 3-methyladenine, an
inhibitor of autophagy, abolished the neuroprotection of IPC and, by contrast,
rapamycin, an autophagy inducer, potentiated it. Cleaved caspase-3 expression,
neurological scores, and infarct volume in different groups further confirmed
the protection of IPC against I/R injury. Taken together, our data indicate that
autophagy activation might underlie the protection of IPC against ischemic
injury by inhibiting apoptosis. 相似文献
995.
996.
Peng Chen Zexin Tao Yanyan Song Guifang Liu Haiyan Wang Yao Liu Lizhi Song Yan Li Xiaojuan Lin Ning Cui Aiqiang Xu 《Journal of medical virology》2013,85(3):483-489
In 2009, a major outbreak of aseptic meningitis was noted in Linyi city, Shandong province, China. From June to September 2009, a total of 2,104 cases were involved in this outbreak, and 98.6% of patients were <16 years of age. To determine the pathogen of the outbreak, 42 cerebrospinal fluid specimens collected from aseptic meningitis cases were tested for cell culture, and 17 (40.5%) enteroviruses were isolated and identified as Coxsackievirus B5 (CVB5). Homologous comparison indicated that these isolates had 0–7.7% nucleotide divergence with each other. Phylogenetic reconstruction showed global CVB5 could be separated into four genogroups, and all Linyi CVB5 isolates belonged to the genogroup C which had been circulating for recent 27 years in Asia and Europe. Interestingly, two distinct lineages were observed for the 17 isolates in the phylogenetic tree, indicating that at least two different transmission chains of CVB5 were responsible for this outbreak. This study showed that CVB5‐associated aseptic meningitis is an emerging concern in China. J. Med. Virol. 85:483–489, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
997.
998.
999.
Psychiatric Quarterly - Diabetes mellitus (DM) is one of the remarkable disease challenges in the twenty-first century and poses threat to patients’ physical health. Given the difficulty of... 相似文献
1000.