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   164917篇
  免费   5800篇
  国内免费   5450篇
  176167篇
  2024年   154篇
  2023年   1035篇
  2022年   2392篇
  2021年   4076篇
  2020年   2619篇
  2019年   3232篇
  2018年   14131篇
  2017年   12237篇
  2016年   10217篇
  2015年   5359篇
  2014年   5820篇
  2013年   6267篇
  2012年   10966篇
  2011年   18328篇
  2010年   15171篇
  2009年   11203篇
  2008年   13229篇
  2007年   14370篇
  2006年   3150篇
  2005年   2866篇
  2004年   2896篇
  2003年   2646篇
  2002年   2161篇
  2001年   1483篇
  2000年   1375篇
  1999年   1145篇
  1998年   668篇
  1997年   677篇
  1996年   675篇
  1995年   616篇
  1994年   549篇
  1993年   405篇
  1992年   588篇
  1991年   472篇
  1990年   413篇
  1989年   289篇
  1988年   261篇
  1987年   247篇
  1986年   167篇
  1985年   194篇
  1984年   116篇
  1983年   134篇
  1982年   73篇
  1981年   58篇
  1980年   38篇
  1979年   61篇
  1974年   38篇
  1973年   34篇
  1972年   276篇
  1971年   297篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
921.
Long noncoding RNAs(IncRNAs)act as essential regulators of various diseases.However,the func-tions of IncRNAs in sepsis-induced acute lung injury(SALI)remain un...  相似文献   
922.
923.
Syntaxin-1是一种多结构域蛋白,通过与synaptobrevin-2和SNAP-25形成SNARE复合体调节囊泡融合.然而,syntaxin-1在突触形成过程中是否发挥作用,目前尚不清楚.本研究显示syntaxin-1的表达水平与突触形成过程高度相关.Syntaxin-1的R151A和I155A突变影响其在突触形成中的促进作用,而Habc结构域或跨膜结构域在突触形成中无显著作用.结果表明,syntaxin-1通过激活突触囊泡释放来加速突触的形成.  相似文献   
924.
Puccinia striiformis f. sp. tritici (Pst) secretes an array of specific effector proteins to manipulate host immunity and promote pathogen colonization. In a previous study, we functionally characterized a glycine-serine-rich effector PstGSRE1 with a glycine-serine-rich motif (m9). However, the mechanisms of glycine-serine-rich effectors (GSREs) remain obscure. Here we report a new glycine-serine-rich effector, PstGSRE4, which has no m9-like motif but inhibits the enzyme activity of wheat copper zinc superoxide dismutase TaCZSOD2, which acts as a positive regulator of wheat resistance to Pst. By inhibiting the enzyme activity of TaCZSOD2, PstGSRE4 reduces H2O2 accumulation and HR areas to facilitate Pst infection. These findings provide new insights into the molecular mechanisms of GSREs of rust fungi in regulating plant immunity.  相似文献   
925.
Patients with hormone receptor(HR)-positive tumors breast cancer usually experience a relatively low pathological complete response(p CR) to neoadjuvant chemotherapy(NAC). Here, we derived a 10-micro RNA risk score(10-mi RNA RS)-based model with better performance in the prediction of p CR and validated its relation with the disease-free survival(DFS) in 755 HRpositive breast cancer patients(273, 265, and 217 in the training, internal, and external validation sets, respectively). This model,pres...  相似文献   
926.
Animal cloning can be achieved by somatic cell nuclear transfer(SCNT), but the resulting live birth rate is relatively low. We previously improved the efficiency of bovine SCNT by exogenous melatonin treatment or by overexpression of lysine-specific demethylase 4D(KDM4D) and 4E(KDM4E). In this study, we revealed abundant alternative splicing(AS) transitions during fertilization and embryonic genome activation, and demonstrated abnormal AS in bovine SCNT embryos compared with in vitro fertilized ...  相似文献   
927.
<正>Dear Editor,Soybean(Glycine max [L.] Merr.) provides more than half of the oilseeds and more than a quarter of protein worldwide. It is estimated that the production of soybean has to be doubled by 2050 to meet the needs of the rapidly increasing consumption of soybean seeds along with a continuously increasing population(Ray et al., 2013). As such, development of a genotyping platform with high throughput, high efficiency and high precision but low-cost is urgently needed to accelerate...  相似文献   
928.
本研究以高原鳅属6个群体共82尾个体的线粒体DNA D-loop高变区为标记,采用分子生物信息学方法分析其遗传多样性及系统发育关系.结果表明,在570 bp的mtDNA D-loop中共检测到149个多态位点,由此界定了 39个单倍型.在6个群体中,单倍型多样度(Hd)由高到低依次为细尾高原鳅(T.stenura)(0...  相似文献   
929.
Keloid disorder is a tumour-like disease with invasive growth and a high recurrence rate. Genetic contribution is well expected due to the presence of autosomal dominant inheritance and various genetic mutations in keloid lesions. However, GWAS failed to reveal functional variants in exon regions but single nucleotide polymorphisms in the non-coding regions, suggesting the necessity of innovative genetic investigation. This study employed combined GWAS, RNA-sequence and Hi-C analyses to dissect keloid disorder genetic mechanisms using paired keloid tissues and normal skins. Differentially expressed genes, miRNAs and lncRNAs mined by RNA-sequence were identified to construct a network. From which, 8 significant pathways involved in keloid disorder pathogenesis were enriched and 6 of them were verified. Furthermore, topologically associated domains at susceptible loci were located via the Hi-C database and ten differentially expressed RNAs were identified. Among them, the functions of six molecules for cell proliferation, cell cycle and apoptosis were particularly examined and confirmed by overexpressing and knocking-down assays. This study firstly revealed unknown key biomarkers and pathways in keloid lesions using RNA-sequence and previously reported mutation loci, indicating a feasible approach to reveal the genetic contribution to keloid disorder and possibly to other diseases that are failed by GWAS analysis alone.  相似文献   
930.
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