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91.
Friml J Vieten A Sauer M Weijers D Schwarz H Hamann T Offringa R Jürgens G 《Nature》2003,426(6963):147-153
Axis formation occurs in plants, as in animals, during early embryogenesis. However, the underlying mechanism is not known. Here we show that the first manifestation of the apical-basal axis in plants, the asymmetric division of the zygote, produces a basal cell that transports and an apical cell that responds to the signalling molecule auxin. This apical-basal auxin activity gradient triggers the specification of apical embryo structures and is actively maintained by a novel component of auxin efflux, PIN7, which is located apically in the basal cell. Later, the developmentally regulated reversal of PIN7 and onset of PIN1 polar localization reorganize the auxin gradient for specification of the basal root pole. An analysis of pin quadruple mutants identifies PIN-dependent transport as an essential part of the mechanism for embryo axis formation. Our results indicate how the establishment of cell polarity, polar auxin efflux and local auxin response result in apical-basal axis formation of the embryo, and thus determine the axiality of the adult plant. 相似文献
92.
Howitz KT Bitterman KJ Cohen HY Lamming DW Lavu S Wood JG Zipkin RE Chung P Kisielewski A Zhang LL Scherer B Sinclair DA 《Nature》2003,425(6954):191-196
In diverse organisms, calorie restriction slows the pace of ageing and increases maximum lifespan. In the budding yeast Saccharomyces cerevisiae, calorie restriction extends lifespan by increasing the activity of Sir2 (ref. 1), a member of the conserved sirtuin family of NAD(+)-dependent protein deacetylases. Included in this family are SIR-2.1, a Caenorhabditis elegans enzyme that regulates lifespan, and SIRT1, a human deacetylase that promotes cell survival by negatively regulating the p53 tumour suppressor. Here we report the discovery of three classes of small molecules that activate sirtuins. We show that the potent activator resveratrol, a polyphenol found in red wine, lowers the Michaelis constant of SIRT1 for both the acetylated substrate and NAD(+), and increases cell survival by stimulating SIRT1-dependent deacetylation of p53. In yeast, resveratrol mimics calorie restriction by stimulating Sir2, increasing DNA stability and extending lifespan by 70%. We discuss possible evolutionary origins of this phenomenon and suggest new lines of research into the therapeutic use of sirtuin activators. 相似文献
93.
Genome-wide association defines more than 30 distinct susceptibility loci for Crohn's disease 总被引:2,自引:0,他引:2
Barrett JC Hansoul S Nicolae DL Cho JH Duerr RH Rioux JD Brant SR Silverberg MS Taylor KD Barmada MM Bitton A Dassopoulos T Datta LW Green T Griffiths AM Kistner EO Murtha MT Regueiro MD Rotter JI Schumm LP Steinhart AH Targan SR Xavier RJ;NIDDK IBD Genetics Consortium Libioulle C Sandor C Lathrop M Belaiche J Dewit O Gut I Heath S Laukens D Mni M Rutgeerts P Van Gossum A Zelenika D Franchimont D Hugot JP de Vos M Vermeire S 《Nature genetics》2008,40(8):955-962
Several risk factors for Crohn's disease have been identified in recent genome-wide association studies. To advance gene discovery further, we combined data from three studies on Crohn's disease (a total of 3,230 cases and 4,829 controls) and carried out replication in 3,664 independent cases with a mixture of population-based and family-based controls. The results strongly confirm 11 previously reported loci and provide genome-wide significant evidence for 21 additional loci, including the regions containing STAT3, JAK2, ICOSLG, CDKAL1 and ITLN1. The expanded molecular understanding of the basis of this disease offers promise for informed therapeutic development. 相似文献
94.
Bovee D Zhou Y Haugen E Wu Z Hayden HS Gillett W Tuzun E Cooper GM Sampas N Phelps K Levy R Morrison VA Sprague J Jewett D Buckley D Subramaniam S Chang J Smith DR Olson MV Eichler EE Kaul R 《Nature genetics》2008,40(1):96-101
The human genome sequence has been finished to very high standards; however, more than 340 gaps remained when the finished genome was published by the International Human Genome Sequencing Consortium in 2004. Using fosmid resources generated from multiple individuals, we targeted gaps in the euchromatic part of the human genome. Here we report 2,488,842 bp of previously unknown euchromatic sequence, 363,114 bp of which close 26 of 250 euchromatic gaps, or 10%, including two remaining euchromatic gaps on chromosome 19. Eight (30.7%) of the closed gaps were found to be polymorphic. These sequences allow complete annotation of several human genes as well as the assignment of mRNAs. The gap sequences are 2.3-fold enriched in segmentally duplicated sequences compared to the whole genome. Our analysis confirms that not all gaps within 'finished' genomes are recalcitrant to subcloning and suggests that the paired-end-sequenced fosmid libraries could prove to be a rich resource for completion of the human euchromatic genome. 相似文献
95.
Willer CJ Sanna S Jackson AU Scuteri A Bonnycastle LL Clarke R Heath SC Timpson NJ Najjar SS Stringham HM Strait J Duren WL Maschio A Busonero F Mulas A Albai G Swift AJ Morken MA Narisu N Bennett D Parish S Shen H Galan P Meneton P Hercberg S Zelenika D Chen WM Li Y Scott LJ Scheet PA Sundvall J Watanabe RM Nagaraja R Ebrahim S Lawlor DA Ben-Shlomo Y Davey-Smith G Shuldiner AR Collins R Bergman RN Uda M Tuomilehto J Cao A Collins FS Lakatta E Lathrop GM Boehnke M Schlessinger D Mohlke KL 《Nature genetics》2008,40(2):161-169
To identify genetic variants influencing plasma lipid concentrations, we first used genotype imputation and meta-analysis to combine three genome-wide scans totaling 8,816 individuals and comprising 6,068 individuals specific to our study (1,874 individuals from the FUSION study of type 2 diabetes and 4,184 individuals from the SardiNIA study of aging-associated variables) and 2,758 individuals from the Diabetes Genetics Initiative, reported in a companion study in this issue. We subsequently examined promising signals in 11,569 additional individuals. Overall, we identify strongly associated variants in eleven loci previously implicated in lipid metabolism (ABCA1, the APOA5-APOA4-APOC3-APOA1 and APOE-APOC clusters, APOB, CETP, GCKR, LDLR, LPL, LIPC, LIPG and PCSK9) and also in several newly identified loci (near MVK-MMAB and GALNT2, with variants primarily associated with high-density lipoprotein (HDL) cholesterol; near SORT1, with variants primarily associated with low-density lipoprotein (LDL) cholesterol; near TRIB1, MLXIPL and ANGPTL3, with variants primarily associated with triglycerides; and a locus encompassing several genes near NCAN, with variants strongly associated with both triglycerides and LDL cholesterol). Notably, the 11 independent variants associated with increased LDL cholesterol concentrations in our study also showed increased frequency in a sample of coronary artery disease cases versus controls. 相似文献
96.
Identification of ten loci associated with height highlights new biological pathways in human growth 总被引:1,自引:0,他引:1
Lettre G Jackson AU Gieger C Schumacher FR Berndt SI Sanna S Eyheramendy S Voight BF Butler JL Guiducci C Illig T Hackett R Heid IM Jacobs KB Lyssenko V Uda M;Diabetes Genetics Initiative;FUSION;KORA;Prostate Lung Colorectal Ovarian Cancer Screening Trial;Nurses' Health Study;SardiNIA Boehnke M Chanock SJ Groop LC Hu FB Isomaa B Kraft P Peltonen L Salomaa V Schlessinger D Hunter DJ Hayes RB Abecasis GR Wichmann HE Mohlke KL Hirschhorn JN 《Nature genetics》2008,40(5):584-591
Height is a classic polygenic trait, reflecting the combined influence of multiple as-yet-undiscovered genetic factors. We carried out a meta-analysis of genome-wide association study data of height from 15,821 individuals at 2.2 million SNPs, and followed up the strongest findings in >10,000 subjects. Ten newly identified and two previously reported loci were strongly associated with variation in height (P values from 4 x 10(-7) to 8 x 10(-22)). Together, these 12 loci account for approximately 2% of the population variation in height. Individuals with < or =8 height-increasing alleles and > or =16 height-increasing alleles differ in height by approximately 3.5 cm. The newly identified loci, along with several additional loci with strongly suggestive associations, encompass both strong biological candidates and unexpected genes, and highlight several pathways (let-7 targets, chromatin remodeling proteins and Hedgehog signaling) as important regulators of human stature. These results expand the picture of the biological regulation of human height and of the genetic architecture of this classical complex trait. 相似文献
97.
Coucke PJ Willaert A Wessels MW Callewaert B Zoppi N De Backer J Fox JE Mancini GM Kambouris M Gardella R Facchetti F Willems PJ Forsyth R Dietz HC Barlati S Colombi M Loeys B De Paepe A 《Nature genetics》2006,38(4):452-457
Arterial tortuosity syndrome (ATS) is an autosomal recessive disorder characterized by tortuosity, elongation, stenosis and aneurysm formation in the major arteries owing to disruption of elastic fibers in the medial layer of the arterial wall. Previously, we used homozygosity mapping to map a candidate locus in a 4.1-Mb region on chromosome 20q13.1 (ref. 2). Here, we narrowed the candidate region to 1.2 Mb containing seven genes. Mutations in one of these genes, SLC2A10, encoding the facilitative glucose transporter GLUT10, were identified in six ATS families. GLUT10 deficiency is associated with upregulation of the TGFbeta pathway in the arterial wall, a finding also observed in Loeys-Dietz syndrome, in which aortic aneurysms associate with arterial tortuosity. The identification of a glucose transporter gene responsible for altered arterial morphogenesis is notable in light of the previously suggested link between GLUT10 and type 2 diabetes. Our data could provide new insight on the mechanisms causing microangiopathic changes associated with diabetes and suggest that therapeutic compounds intervening with TGFbeta signaling represent a new treatment strategy. 相似文献
98.
Fischer J Lefèvre C Morava E Mussini JM Laforêt P Negre-Salvayre A Lathrop M Salvayre R 《Nature genetics》2007,39(1):28-30
Neutral lipid storage disease comprises a heterogeneous group of autosomal recessive disorders characterized by systemic accumulation of triglycerides in cytoplasmic droplets. Here we report a neutral lipid storage disease subgroup characterized by mild myopathy, absence of ichthyosis and mutations in both alleles of adipose triglyceride lipase (PNPLA2, also known as ATGL). Three of these mutations are predicted to lead to a truncated ATGL protein with an intact patatin domain containing the active site, but with defects in the hydrophobic domain. The block in triglyceride degradation was mimicked by short interfering RNA directed against ATGL. NLSDM is distinct from Chanarin-Dorfman syndrome, which is characterized by neutral lipid storage disease with ichthyosis, mild myopathy and hepatomegaly due to mutations in ABHD5 (also known as CGI-58). 相似文献
99.
Mailman MD Feolo M Jin Y Kimura M Tryka K Bagoutdinov R Hao L Kiang A Paschall J Phan L Popova N Pretel S Ziyabari L Lee M Shao Y Wang ZY Sirotkin K Ward M Kholodov M Zbicz K Beck J Kimelman M Shevelev S Preuss D Yaschenko E Graeff A Ostell J Sherry ST 《Nature genetics》2007,39(10):1181-1186
The National Center for Biotechnology Information has created the dbGaP public repository for individual-level phenotype, exposure, genotype and sequence data and the associations between them. dbGaP assigns stable, unique identifiers to studies and subsets of information from those studies, including documents, individual phenotypic variables, tables of trait data, sets of genotype data, computed phenotype-genotype associations, and groups of study subjects who have given similar consents for use of their data. 相似文献
100.
Blastocyst implantation depends on maternal expression of leukaemia inhibitory factor. 总被引:87,自引:0,他引:87
C L Stewart P Kaspar L J Brunet H Bhatt I Gadi F K?ntgen S J Abbondanzo 《Nature》1992,359(6390):76-79
A critical point during mammalian pregnancy is the implantation of the blastocyst when the embryo attaches to the wall of the uterus. The autonomously developing preimplantation embryo then becomes dependent on the maternal environment for its continued development. Little is known about the regulation of implantation, except that a complex interaction between peptide and steroid hormones synchronizes the preparation of the uterus for implantation with the development of the embryo. Whether the implantation event is under maternal or embryonic control is also unclear (reviewed in refs 1, 2). We have previously shown that a cytokine, leukaemia inhibitory factor (LIF), is expressed in the uterine endometrial glands specifically on the fourth day of pregnancy. This burst of expression is under maternal control and always precedes implantation of the blastocyst. Here we report that transient expression of LIF in mice is essential for implantation. Females lacking a functional LIF gene are fertile, but their blastocysts fail to implant and do not develop. The blastocysts, however, are viable and, when transferred to wild-type pseudopregnant recipients, they can implant and develop to term. 相似文献