全文获取类型
收费全文 | 11527篇 |
免费 | 1101篇 |
出版年
2023年 | 55篇 |
2022年 | 124篇 |
2021年 | 302篇 |
2020年 | 145篇 |
2019年 | 206篇 |
2018年 | 251篇 |
2017年 | 214篇 |
2016年 | 322篇 |
2015年 | 562篇 |
2014年 | 634篇 |
2013年 | 694篇 |
2012年 | 1055篇 |
2011年 | 1054篇 |
2010年 | 615篇 |
2009年 | 529篇 |
2008年 | 802篇 |
2007年 | 780篇 |
2006年 | 705篇 |
2005年 | 626篇 |
2004年 | 590篇 |
2003年 | 534篇 |
2002年 | 471篇 |
2001年 | 138篇 |
2000年 | 81篇 |
1999年 | 101篇 |
1998年 | 92篇 |
1997年 | 61篇 |
1996年 | 42篇 |
1995年 | 36篇 |
1994年 | 29篇 |
1993年 | 35篇 |
1992年 | 51篇 |
1991年 | 41篇 |
1990年 | 43篇 |
1989年 | 40篇 |
1988年 | 29篇 |
1987年 | 30篇 |
1986年 | 31篇 |
1985年 | 25篇 |
1984年 | 29篇 |
1983年 | 30篇 |
1982年 | 24篇 |
1981年 | 23篇 |
1979年 | 26篇 |
1978年 | 16篇 |
1975年 | 17篇 |
1973年 | 19篇 |
1972年 | 17篇 |
1970年 | 17篇 |
1966年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
991.
ZINBA (Zero-Inflated Negative Binomial Algorithm) identifies genomic regions enriched in a variety of ChIP-seq and related
next-generation sequencing experiments (DNA-seq), calling both broad and narrow modes of enrichment across a range of signal-to-noise
ratios. ZINBA models and accounts for factors that co-vary with background or experimental signal, such as G/C content, and
identifies enrichment in genomes with complex local copy number variations. ZINBA provides a single unified framework for
analyzing DNA-seq experiments in challenging genomic contexts. 相似文献
992.
993.
Ye L Hillier LW Minx P Thane N Locke DP Martin JC Chen L Mitreva M Miller JR Haub KV Dooling DJ Mardis ER Wilson RK Weinstock GM Warren WC 《Genome biology》2011,12(3):R31-7
The unparalleled efficiency of next-generation sequencing (NGS) has prompted widespread adoption, but significant problems remain in the use of NGS data for whole genome assembly. We explore the advantages and disadvantages of chicken genome assemblies generated using a variety of sequencing and assembly methodologies. NGS assemblies are equivalent in some ways to a Sanger-based assembly yet deficient in others. Nonetheless, these assemblies are sufficient for the identification of the majority of genes and can reveal novel sequences when compared to existing assembly references. 相似文献
994.
995.
Most proteins are only barely stable, which impedes research, complicates therapeutic applications, and makes proteins susceptible to pathologically destabilizing mutations. Our ability to predict the thermodynamic consequences of even single point mutations is still surprisingly limited, and established methods of measuring stability are slow. Recent advances are bringing protein stability studies into the high-throughput realm. Some methods are based on inferential read-outs such as activity, proteolytic resistance or split-protein fragment reassembly. Other methods use miniaturization of direct measurements, such as intrinsic fluorescence, H/D exchange, cysteine reactivity, aggregation and hydrophobic dye binding (DSF). Protein engineering based on statistical analysis (consensus and correlated occurrences of amino acids) is promising, but much work remains to understand and implement these methods. 相似文献
996.
Dysfunction of hepatic insulin receptor tyrosine kinase (IRTK) causes the development of type 2 diabetes. However, the molecular mechanism regulating IRTK activity in the liver remains poorly understood. Here, we show that phosphoinositide 3-kinase enhancer A (PIKE-A) is a new insulin-dependent enhancer of hepatic IRTK. Liver-specific Pike-knockout (LPKO) mice display glucose intolerance with impaired hepatic insulin sensitivity. Specifically, insulin-provoked phosphoinositide 3-kinase/Akt signalling is diminished in the liver of LPKO mice, leading to the failure of insulin-suppressed gluconeogenesis and hyperglycaemia. Thus, hepatic PIKE-A has a key role in mediating insulin signal transduction and regulating glucose homeostasis in the liver. 相似文献
997.
The quasi-experimental approach of before–after control–impact (BACI) sampling can help decide when changes are due to human activities rather than natural variability. Detailed arguments for and against BACI designs and analytic methods are widespread in the literature, but far less attention has been paid to the mechanics of analyzing a BACI experiment. This paper demonstrates randomized intervention analysis with user-friendly software, where observations are paired in time before and after intervention. We provide examples using dragonfly count data in vegetation removal experiments. 相似文献
998.
Viatcheslav Gurev Ted Lee Jason Constantino Hermenegild Arevalo Natalia A. Trayanova 《Biomechanics and modeling in mechanobiology》2011,10(3):295-306
Current multi-scale computational models of ventricular electromechanics describe the full process of cardiac contraction
on both the micro- and macro- scales including: the depolarization of cardiac cells, the release of calcium from intracellular
stores, tension generation by cardiac myofilaments, and mechanical contraction of the whole heart. Such models are used to
reveal basic mechanisms of cardiac contraction as well as the mechanisms of cardiac dysfunction in disease conditions. In
this paper, we present a methodology to construct finite element electromechanical models of ventricular contraction with
anatomically accurate ventricular geometry based on magnetic resonance and diffusion tensor magnetic resonance imaging of
the heart. The electromechanical model couples detailed representations of the cardiac cell membrane, cardiac myofilament
dynamics, electrical impulse propagation, ventricular contraction, and circulation to simulate the electrical and mechanical
activity of the ventricles. The utility of the model is demonstrated in an example simulation of contraction during sinus
rhythm using a model of the normal canine ventricles. 相似文献
999.
Many studies demonstrate the social benefits of cooperation. Likewise, recent studies convincingly demonstrate that betrayal aversion hinders trust and discourages cooperation. In this respect, betrayal aversion is unlike socially "beneficial" preferences including altruism, fairness and inequity aversion, all of which encourage cooperation and exchange. To our knowledge, other than the suggestion that it acts as a barrier to rash trust decisions, the benefits of betrayal aversion remain largely unexplored. Here we use laboratory experiments with human participants to show that groups including betrayal-averse agents achieve higher levels of reciprocity and more profitable social exchange than groups lacking betrayal aversion. These results are the first rigorous evidence on the benefits of betrayal aversion, and may help future research investigating cultural differences in betrayal aversion as well as future research on the evolutionary roots of betrayal aversion. Further, our results extend the understanding of how intentions affect social interactions and exchange and provide an effective platform for further research on betrayal aversion and its effects on human behavior. 相似文献
1000.
Almendinger J Doukoumetzidis K Kinchen JM Kaech A Ravichandran KS Hengartner MO 《PloS one》2011,6(4):e18325
Clearance of apoptotic cells is of key importance during development, tissue homeostasis and wound healing in multi-cellular animals. Genetic studies in the nematode Caenorhabditis elegans have identified a set of genes involved in the early steps of cell clearance, in particular the recognition and internalization of apoptotic cells. A pathway that orchestrates the maturation of phagosomes containing ingested apoptotic cells in the worm has recently been described. However, many steps in this pathway remain elusive. Here we show that the C. elegans SNX9-family member LST-4 (lateral signaling target) and its closest mammalian orthologue SNX33 play an evolutionary conserved role during apoptotic cell corpse clearance. In lst-4 deficient worms, internalized apoptotic cells accumulated within non-acidified, DYN-1-positive but RAB-5-negative phagosomes. Genetically, we show that LST-4 functions at the same step as DYN-1 during corpse removal, upstream of the GTPase RAB-5. We further show that mammalian SNX33 rescue C. elegans lst-4 mutants and that overexpression of truncated SNX33 fragments interfered with phagosome maturation in a mammalian cell system. Taken together, our genetic and cell biological analyses suggest that LST-4 is recruited through a combined activity of DYN-1 and VPS-34 to the early phagosome membrane, where it cooperates with DYN-1 to promote recruitment/retention of RAB-5 on the early phagosomal membrane during cell corpse clearance. The functional conservation between LST-4 and SNX33 indicate that these early steps of apoptotic phagosome maturation are likely conserved through evolution. 相似文献