全文获取类型
收费全文 | 31537篇 |
免费 | 79篇 |
国内免费 | 117篇 |
专业分类
系统科学 | 155篇 |
丛书文集 | 352篇 |
教育与普及 | 99篇 |
理论与方法论 | 159篇 |
现状及发展 | 14326篇 |
研究方法 | 1321篇 |
综合类 | 14850篇 |
自然研究 | 471篇 |
出版年
2012年 | 483篇 |
2011年 | 920篇 |
2010年 | 222篇 |
2008年 | 595篇 |
2007年 | 594篇 |
2006年 | 598篇 |
2005年 | 625篇 |
2004年 | 655篇 |
2003年 | 569篇 |
2002年 | 542篇 |
2001年 | 823篇 |
2000年 | 824篇 |
1999年 | 579篇 |
1994年 | 349篇 |
1992年 | 478篇 |
1991年 | 391篇 |
1990年 | 463篇 |
1989年 | 442篇 |
1988年 | 444篇 |
1987年 | 470篇 |
1986年 | 469篇 |
1985年 | 599篇 |
1984年 | 435篇 |
1983年 | 390篇 |
1982年 | 379篇 |
1981年 | 346篇 |
1980年 | 416篇 |
1979年 | 920篇 |
1978年 | 742篇 |
1977年 | 707篇 |
1976年 | 570篇 |
1975年 | 694篇 |
1974年 | 883篇 |
1973年 | 782篇 |
1972年 | 829篇 |
1971年 | 972篇 |
1970年 | 1140篇 |
1969年 | 987篇 |
1968年 | 983篇 |
1967年 | 900篇 |
1966年 | 789篇 |
1965年 | 587篇 |
1964年 | 220篇 |
1959年 | 324篇 |
1958年 | 595篇 |
1957年 | 429篇 |
1956年 | 365篇 |
1955年 | 332篇 |
1954年 | 355篇 |
1948年 | 290篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
671.
Giardine B Borg J Higgs DR Peterson KR Philipsen S Maglott D Singleton BK Anstee DJ Basak AN Clark B Costa FC Faustino P Fedosyuk H Felice AE Francina A Galanello R Gallivan MV Georgitsi M Gibbons RJ Giordano PC Harteveld CL Hoyer JD Jarvis M Joly P Kanavakis E Kollia P Menzel S Miller W Moradkhani K Old J Papachatzopoulou A Papadakis MN Papadopoulos P Pavlovic S Perseu L Radmilovic M Riemer C Satta S Schrijver I Stojiljkovic M Thein SL Traeger-Synodinos J Tully R Wada T Waye JS Wiemann C 《Nature genetics》2011,43(4):295-301
We developed a series of interrelated locus-specific databases to store all published and unpublished genetic variation related to hemoglobinopathies and thalassemia and implemented microattribution to encourage submission of unpublished observations of genetic variation to these public repositories. A total of 1,941 unique genetic variants in 37 genes, encoding globins and other erythroid proteins, are currently documented in these databases, with reciprocal attribution of microcitations to data contributors. Our project provides the first example of implementing microattribution to incentivise submission of all known genetic variation in a defined system. It has demonstrably increased the reporting of human variants, leading to a comprehensive online resource for systematically describing human genetic variation in the globin genes and other genes contributing to hemoglobinopathies and thalassemias. The principles established here will serve as a model for other systems and for the analysis of other common and/or complex human genetic diseases. 相似文献
672.
Crossan GP van der Weyden L Rosado IV Langevin F Gaillard PH McIntyre RE;Sanger Mouse Genetics Project Gallagher F Kettunen MI Lewis DY Brindle K Arends MJ Adams DJ Patel KJ 《Nature genetics》2011,43(2):147-152
The evolutionarily conserved SLX4 protein, a key regulator of nucleases, is critical for DNA damage response. SLX4 nuclease complexes mediate repair during replication and can also resolve Holliday junctions formed during homologous recombination. Here we describe the phenotype of the Btbd12 knockout mouse, the mouse ortholog of SLX4, which recapitulates many key features of the human genetic illness Fanconi anemia. Btbd12-deficient animals are born at sub-Mendelian ratios, have greatly reduced fertility, are developmentally compromised and are prone to blood cytopenias. Btbd12(-/-) cells prematurely senesce, spontaneously accumulate damaged chromosomes and are particularly sensitive to DNA crosslinking agents. Genetic complementation reveals a crucial requirement for Btbd12 (also known as Slx4) to interact with the structure-specific endonuclease Xpf-Ercc1 to promote crosslink repair. The Btbd12 knockout mouse therefore establishes a disease model for Fanconi anemia and genetically links a regulator of nuclease incision complexes to the Fanconi anemia DNA crosslink repair pathway. 相似文献
673.
Common variants at MS4A4/MS4A6E, CD2AP, CD33 and EPHA1 are associated with late-onset Alzheimer's disease 总被引:1,自引:0,他引:1
Naj AC Jun G Beecham GW Wang LS Vardarajan BN Buros J Gallins PJ Buxbaum JD Jarvik GP Crane PK Larson EB Bird TD Boeve BF Graff-Radford NR De Jager PL Evans D Schneider JA Carrasquillo MM Ertekin-Taner N Younkin SG Cruchaga C Kauwe JS Nowotny P Kramer P Hardy J Huentelman MJ Myers AJ Barmada MM Demirci FY Baldwin CT Green RC Rogaeva E St George-Hyslop P Arnold SE Barber R Beach T Bigio EH Bowen JD Boxer A Burke JR Cairns NJ Carlson CS Carney RM Carroll SL Chui HC Clark DG Corneveaux J Cotman CW 《Nature genetics》2011,43(5):436-441
The Alzheimer Disease Genetics Consortium (ADGC) performed a genome-wide association study of late-onset Alzheimer disease using a three-stage design consisting of a discovery stage (stage 1) and two replication stages (stages 2 and 3). Both joint analysis and meta-analysis approaches were used. We obtained genome-wide significant results at MS4A4A (rs4938933; stages 1 and 2, meta-analysis P (P(M)) = 1.7 × 10(-9), joint analysis P (P(J)) = 1.7 × 10(-9); stages 1, 2 and 3, P(M) = 8.2 × 10(-12)), CD2AP (rs9349407; stages 1, 2 and 3, P(M) = 8.6 × 10(-9)), EPHA1 (rs11767557; stages 1, 2 and 3, P(M) = 6.0 × 10(-10)) and CD33 (rs3865444; stages 1, 2 and 3, P(M) = 1.6 × 10(-9)). We also replicated previous associations at CR1 (rs6701713; P(M) = 4.6 × 10(-10), P(J) = 5.2 × 10(-11)), CLU (rs1532278; P(M) = 8.3 × 10(-8), P(J) = 1.9 × 10(-8)), BIN1 (rs7561528; P(M) = 4.0 × 10(-14), P(J) = 5.2 × 10(-14)) and PICALM (rs561655; P(M) = 7.0 × 10(-11), P(J) = 1.0 × 10(-10)), but not at EXOC3L2, to late-onset Alzheimer's disease susceptibility. 相似文献
674.
Isidor B Lindenbaum P Pichon O Bézieau S Dina C Jacquemont S Martin-Coignard D Thauvin-Robinet C Le Merrer M Mandel JL David A Faivre L Cormier-Daire V Redon R Le Caignec C 《Nature genetics》2011,43(4):306-308
Hajdu-Cheney syndrome is a rare autosomal dominant skeletal disorder with facial anomalies, osteoporosis and acro-osteolysis. We sequenced the exomes of six unrelated individuals with this syndrome and identified heterozygous nonsense and frameshift mutations in NOTCH2 in five of them. All mutations cluster to the last coding exon of the gene, suggesting that the mutant mRNA products escape nonsense-mediated decay and that the resulting truncated NOTCH2 proteins act in a gain-of-function manner. 相似文献
675.
Burdon KP Macgregor S Hewitt AW Sharma S Chidlow G Mills RA Danoy P Casson R Viswanathan AC Liu JZ Landers J Henders AK Wood J Souzeau E Crawford A Leo P Wang JJ Rochtchina E Nyholt DR Martin NG Montgomery GW Mitchell P Brown MA Mackey DA Craig JE 《Nature genetics》2011,43(6):574-578
We report a genome-wide association study for open-angle glaucoma (OAG) blindness using a discovery cohort of 590 individuals with severe visual field loss (cases) and 3,956 controls. We identified associated loci at TMCO1 (rs4656461[G] odds ratio (OR) = 1.68, P = 6.1 × 10(-10)) and CDKN2B-AS1 (rs4977756[A] OR = 1.50, P = 4.7 × 10(-9)). We replicated these associations in an independent cohort of cases with advanced OAG (rs4656461 P = 0.010; rs4977756 P = 0.042) and two additional cohorts of less severe OAG (rs4656461 combined discovery and replication P = 6.00 × 10(-14), OR = 1.51, 95% CI 1.35-1.68; rs4977756 combined P = 1.35 × 10(-14), OR = 1.39, 95% CI 1.28-1.51). We show retinal expression of genes at both loci in human ocular tissues. We also show that CDKN2A and CDKN2B are upregulated in the retina of a rat model of glaucoma. 相似文献
676.
677.
Gutiérrez-López MD Gilsanz A Yáñez-Mó M Ovalle S Lafuente EM Domínguez C Monk PN González-Alvaro I Sánchez-Madrid F Cabañas C 《Cellular and molecular life sciences : CMLS》2011,68(19):3275-3292
ADAM17/TACE is a metalloproteinase responsible for the shedding of the proinflammatory cytokine TNF-α and many other cell
surface proteins involved in development, cell adhesion, migration, differentiation, and proliferation. Despite the important
biological function of ADAM17, the mechanisms of regulation of its metalloproteinase activity remain largely unknown. We report
here that the tetraspanin CD9 and ADAM17 partially co-localize on the surface of endothelial and monocytic cells. In situ
proximity ligation, co-immunoprecipitation, crosslinking, and pull-down experiments collectively demonstrate a direct association
between these molecules. Functional studies reveal that treatment with CD9-specific antibodies or neoexpression of CD9 exert
negative regulatory effects on ADAM17 sheddase activity. Conversely, CD9 silencing increased the activity of ADAM17 against
its substrates TNF-α and ICAM-1. Taken together, our results show that CD9 associates with ADAM17 and, through this interaction,
negatively regulates the sheddase activity of ADAM17. 相似文献
678.
Biegel E Schmidt S González JM Müller V 《Cellular and molecular life sciences : CMLS》2011,68(4):613-634
Microbes have a fascinating repertoire of bioenergetic enzymes and a huge variety of electron transport chains to cope with
very different environmental conditions, such as different oxygen concentrations, different electron acceptors, pH and salinity.
However, all these electron transport chains cover the redox span from NADH + H+ as the most negative donor to oxygen/H2O as the most positive acceptor or increments thereof. The redox range more negative than −320 mV has been largely ignored.
Here, we have summarized the recent data that unraveled a novel ion-motive electron transport chain, the Rnf complex, that
energetically couples the cellular ferredoxin to the pyridine nucleotide pool. The energetics of the complex and its biochemistry,
as well as its evolution and cellular function in different microbes, is discussed. 相似文献
679.
Thomae AW Baltin J Pich D Deutsch MJ Ravasz M Zeller K Gossen M Hammerschmidt W Schepers A 《Cellular and molecular life sciences : CMLS》2011,68(22):3741-3756
In eukaryotes, binding of the six-subunit origin recognition complex (ORC) to DNA provides an interactive platform for the
sequential assembly of pre-replicative complexes. This process licenses replication origins competent for the subsequent initiation
step. Here, we analyze the contribution of human Orc6, the smallest subunit of ORC, to DNA binding and pre-replicative complex
formation. We show that Orc6 not only interacts with Orc1–Orc5 but also with the initiation factor Cdc6. Biochemical and imaging
experiments reveal that this interaction is required for licensing DNA replication competent. Furthermore, we demonstrate
that Orc6 contributes to the interaction of ORC with the chaperone protein HMGA1a (high mobility group protein A1a). Binding
of human ORC to replication origins is not specified at the level of DNA sequence and the functional organization of origins
is poorly understood. We have identified HMGA1a as one factor that might direct ORC to AT-rich heterochromatic regions. The
systematic analysis of the interaction between ORC and HMGA1a revealed that Orc6 interacts with the acidic C-terminus of HMGA1a
and also with its AT-hooks. Both domains support autonomous replication if targeted to DNA templates. As such, Orc6 functions
at different stages of the replication initiation process. Orc6 can interact with ORC chaperone proteins such as HMGA1a to
facilitate chromatin binding of ORC and is also an essential factor for pre-RC formation. 相似文献
680.