全文获取类型
收费全文 | 78871篇 |
免费 | 6540篇 |
国内免费 | 4884篇 |
专业分类
90295篇 |
出版年
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.
Xiaolei Chen Zhongmei Yang Wenfeng Wang Kaiyue Qian Mingjie Liu Junchao Wang Mingzhu Wang 《Nucleic acids research》2021,49(5):2946
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.
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.
Chen Qiumin Yu Guangchao Wang Xiangyu Meng Xiangnan Lv Chunmao 《Journal of Plant Growth Regulation》2021,40(1):147-153
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.
Pengcheng Wang John T Burley Yang Liu Jiang Chang De Chen Qi Lu Shou-Hsien Li Xuming Zhou Scott Edwards Zhengwang Zhang 《Molecular biology and evolution》2021,38(1):263
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.