首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   78871篇
  免费   6540篇
  国内免费   4884篇
  90295篇
  2024年   138篇
  2023年   902篇
  2022年   2076篇
  2021年   3605篇
  2020年   2328篇
  2019年   2841篇
  2018年   2868篇
  2017年   2029篇
  2016年   2874篇
  2015年   4586篇
  2014年   5295篇
  2013年   5964篇
  2012年   6897篇
  2011年   6356篇
  2010年   3818篇
  2009年   3373篇
  2008年   4116篇
  2007年   3657篇
  2006年   3174篇
  2005年   2680篇
  2004年   2280篇
  2003年   1973篇
  2002年   1730篇
  2001年   1559篇
  2000年   1565篇
  1999年   1447篇
  1998年   847篇
  1997年   797篇
  1996年   808篇
  1995年   737篇
  1994年   687篇
  1993年   530篇
  1992年   818篇
  1991年   657篇
  1990年   601篇
  1989年   531篇
  1988年   421篇
  1987年   362篇
  1986年   336篇
  1985年   299篇
  1984年   221篇
  1983年   199篇
  1982年   112篇
  1981年   118篇
  1980年   86篇
  1979年   147篇
  1978年   84篇
  1977年   95篇
  1975年   111篇
  1974年   116篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Tang  Xianfa  Cheng  Hui  Cheng  Lu  Liang  Bo  Chen  Mengyun  Zheng  Xiaodong  Xiao  Fengli 《Molecular biology reports》2021,48(8):5955-5964
Molecular Biology Reports - Vitiligo is a complex disease in which patchy depigmentation is the result of an autoimmune-induced loss of melanocytes in affected regions. On the basis of a...  相似文献   
992.
RBM45 is an RNA-binding protein involved in neural development, whose aggregation is associated with neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and frontotemporal lobar dementia (FTLD). However, the mechanisms of RNA-binding and aggregation of RBM45 remain unelucidated. Here, we report the crystal structure of the N-terminal tandem RRM domains of human RBM45 in complex with single-stranded DNA (ssDNA). Our structural and biochemical results revealed that both the RRM1 and RRM2 of RBM45 recognized the GAC sequence of RNA/ssDNA. Two aromatic residues and an arginine residue in each RRM were critical for RNA-binding, and the interdomain linker was also involved in RNA-binding. Two RRMs formed a pair of antiparallel RNA-binding sites, indicating that the N-terminal tandem RRM domains of RBM45 bound separate GAC motifs in one RNA strand or GAC motifs in different RNA strands. Our findings will be helpful in the identification of physiologic targets of RBM45 and provide evidence for understanding the physiologic and pathologic functions of RBM45.  相似文献   
993.
Chen  Jing-Jing  Shen  Jun-Xian  Yu  Zong-Hao  Pan  Chuan  Han  Fei  Zhu  Xiu-Ling  Xu  Hui  Xu  Rui-Ting  Wei  Tong-Yao  Lu  Ya-Ping 《Neurochemical research》2021,46(3):660-674
Neurochemical Research - Depression afflicts more than 300 million people worldwide, but there is currently no universally effective drug in clinical practice. In this study, chronic restraint...  相似文献   
994.
Dong  Chengya  Wen  Shaohong  Zhao  Shunying  Sun  Si  Zhao  Shangfeng  Dong  Wen  Han  Pingxin  Chen  Qingfang  Gong  Ting  Chen  Wentao  Liu  Wenqian  Liu  Xiangrong 《Neurochemical research》2021,46(4):755-769
Neurochemical Research - Cerebral ischemia leads to reactive astrogliosis and glial scar formation. Glial scarring can impede functional restoration during the recovery phase of stroke. Salidroside...  相似文献   
995.
Chen  Bo  Hua  Zhongyan  Qin  Xiuni  Li  Zhijie 《Neurochemical research》2021,46(2):197-212
Neurochemical Research - Neuroblastomas (NB) are childhood malignant tumors originating in the sympathetic nervous system. MicroRNAs (miRNAs) play an essential regulatory role in tumorigenesis and...  相似文献   
996.
Chen  Yen-Chi  Wang  I-Jen  Cheng  Chih-Ching  Wu  Yu-Chiao  Bai  Chun-Hsuan  Yu  Kuo-Pin 《Aerobiologia》2021,37(2):243-252
Aerobiologia - The liquid impingers can be used for sampling of viral aerosols, such as COVID-19 virus, influenza, and measles. However, the lowest cutoff diameter of commercially available liquid...  相似文献   
997.
Journal of Plant Growth Regulation - Powdery mildew (PM) is one of the most severe foliar diseases in cucumbers (Cucumis sativus L.), but the inheritance of PM resistance remains unclear. The...  相似文献   
998.
999.
Population genetic theory and empirical evidence indicate that deleterious alleles can be purged in small populations. However, this viewpoint remains controversial. It is unclear whether natural selection is powerful enough to purge deleterious mutations when wild populations continue to decline. Pheasants are terrestrial birds facing a long-term risk of extinction as a result of anthropogenic perturbations and exploitation. Nevertheless, there are scant genomics resources available for conservation management and planning. Here, we analyzed comparative population genomic data for the three extant isolated populations of Brown eared pheasant (Crossoptilon mantchuricum) in China. We showed that C. mantchuricum has low genome-wide diversity and a contracting effective population size because of persistent declines over the past 100,000 years. We compared genome-wide variation in C. mantchuricum with that of its closely related sister species, the Blue eared pheasant (C. auritum) for which the conservation concern is low. There were detrimental genetic consequences across all C. mantchuricum genomes including extended runs of homozygous sequences, slow rates of linkage disequilibrium decay, excessive loss-of-function mutations, and loss of adaptive genetic diversity at the major histocompatibility complex region. To the best of our knowledge, this study is the first to perform a comprehensive conservation genomic analysis on this threatened pheasant species. Moreover, we demonstrated that natural selection may not suffice to purge deleterious mutations in wild populations undergoing long-term decline. The findings of this study could facilitate conservation planning for threatened species and help recover their population size.  相似文献   
1000.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号