全文获取类型
收费全文 | 9250篇 |
免费 | 692篇 |
国内免费 | 774篇 |
专业分类
10716篇 |
出版年
2024年 | 19篇 |
2023年 | 128篇 |
2022年 | 299篇 |
2021年 | 509篇 |
2020年 | 311篇 |
2019年 | 442篇 |
2018年 | 401篇 |
2017年 | 252篇 |
2016年 | 428篇 |
2015年 | 591篇 |
2014年 | 698篇 |
2013年 | 791篇 |
2012年 | 893篇 |
2011年 | 763篇 |
2010年 | 437篇 |
2009年 | 434篇 |
2008年 | 456篇 |
2007年 | 399篇 |
2006年 | 358篇 |
2005年 | 258篇 |
2004年 | 249篇 |
2003年 | 208篇 |
2002年 | 149篇 |
2001年 | 139篇 |
2000年 | 121篇 |
1999年 | 105篇 |
1998年 | 101篇 |
1997年 | 92篇 |
1996年 | 84篇 |
1995年 | 71篇 |
1994年 | 65篇 |
1993年 | 48篇 |
1992年 | 81篇 |
1991年 | 48篇 |
1990年 | 36篇 |
1989年 | 39篇 |
1988年 | 25篇 |
1987年 | 27篇 |
1986年 | 30篇 |
1985年 | 26篇 |
1984年 | 13篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 9篇 |
1973年 | 6篇 |
1970年 | 8篇 |
1969年 | 5篇 |
1968年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Inhibition of mitochondrial complex I improves glucose metabolism independently of AMPK activation 下载免费PDF全文
Wo‐Lin Hou Jun Yin Miriayi Alimujiang Xue‐Ying Yu Li‐Gen Ai Yu‐qian Bao Fang Liu Wei‐Ping Jia 《Journal of cellular and molecular medicine》2018,22(2):1316-1328
Accumulating evidences showed metformin and berberine, well‐known glucose‐lowering agents, were able to inhibit mitochondrial electron transport chain at complex I. In this study, we aimed to explore the antihyperglycaemic effect of complex I inhibition. Rotenone, amobarbital and gene silence of NDUFA13 were used to inhibit complex I. Intraperitoneal glucose tolerance test and insulin tolerance test were performed in db/db mice. Lactate release and glucose consumption were measured to investigate glucose metabolism in HepG2 hepatocytes and C2C12 myotubes. Glucose output was measured in primary hepatocytes. Compound C and adenoviruses expressing dominant negative AMP‐activated protein kinase (AMPK) α1/2 were exploited to inactivate AMPK pathway. Cellular NAD+/NADH ratio was assayed to evaluate energy transforming and redox state. Rotenone ameliorated hyperglycaemia and insulin resistance in db/db mice. It induced glucose consumption and glycolysis and reduced hepatic glucose output. Rotenone also activated AMPK. Furthermore, it remained effective with AMPK inactivation. The enhanced glycolysis and repressed gluconeogenesis correlated with a reduction in cellular NAD+/NADH ratio, which resulted from complex I suppression. Amobarbital, another representative complex I inhibitor, stimulated glucose consumption and decreased hepatic glucose output in vitro, too. Similar changes were observed while expression of NDUFA13, a subunit of complex I, was knocked down with gene silencing. These findings reveal mitochondrial complex I emerges as a key drug target for diabetes treatment. Inhibition of complex I improves glucose homoeostasis via non‐AMPK pathway, which may relate to the suppression of the cellular NAD+/NADH ratio. 相似文献
32.
33.
从中国发病鸡中分离的鸡减蛋综合征病毒(EggDropSyndromVirus,EDSV)弱毒株(AA-2),其基因组全长约为33kb。用限制性内切酶HindⅢ水解EDSV全基因组,构建了以pBluescriptⅡ(KS+)为载体的右末端片段的克隆(约4.2kb),对其进行了序列测定和结构分析。该片段全长4183个碱基对(bp),位于基因组右末端87.3m.u.-100m.u.。结果显示,该片段与哺乳动物腺病毒右末端E4区结构不同,与禽Ⅰ型腺病毒代表株CELO右末端片段亦无同源性。本文为深入了解EDSV基因组结构特点,EDSV与其他腺病毒基因结构与功能的进化关系和EDSV载体的构建奠定了分子生物学基础 相似文献
34.
35.
36.
37.
<正>Streptomycetes are Gram-positive bacteria with high GC DNA content. They produce the most abundant secondary metabolites including over two-thirds of the clinically used antibiotics of natural origin (Barka et al., 2016), for example,the important broad-spectrum antimicrobials oxytetracycline(OTC) and chlortetracycline, which are the tetracycline antibiotics, produced by Streptomyces rimosus and Strepto- 相似文献
38.
39.
Zhang W Yue B Wang X Zhang X Xie Z Liu N Fu W Yuan Y Chen D Fu D Zhao B Yin Y Yan X Wang X Zhang R Liu J Li M Tang Y Hou R Zhang Z 《Molecular biology reports》2011,38(7):4257-4264
In order to investigate the mitochondrial genome of Panthera tigris amoyensis, two South China tigers (P25 and P27) were analyzed following 15 cymt-specific primer sets. The entire mtDNA sequence was found to be 16,957 bp and 17,001 bp long for P25 and P27 respectively, and this difference in length between P25 and P27 occurred in the number of tandem repeats in the RS-3 segment of the control region. The structural characteristics of complete P. t. amoyensis mitochondrial genomes were also highly similar to those of P. uncia. Additionally, the rate of point mutation was only 0.3% and a total of 59 variable sites between P25 and P27 were found. Out of the 59 variable sites, 6 were located in 6 different tRNA genes, 6 in the 2 rRNA genes, 7 in non-coding regions (one located between tRNA-Asn and tRNA-Tyr and six in the D-loop), and 40 in 10 protein-coding genes. COI held the largest amount of variable sites (9 sites) and Cytb contained the highest variable rate (0.7%) in the complete sequences. Moreover, out of the 40 variable sites located in 10 protein-coding genes, 12 sites were nonsynonymous. 相似文献
40.