全文获取类型
收费全文 | 1966篇 |
免费 | 308篇 |
专业分类
2274篇 |
出版年
2016年 | 29篇 |
2015年 | 43篇 |
2014年 | 56篇 |
2013年 | 62篇 |
2012年 | 73篇 |
2011年 | 96篇 |
2010年 | 52篇 |
2009年 | 60篇 |
2008年 | 89篇 |
2007年 | 83篇 |
2006年 | 86篇 |
2005年 | 82篇 |
2004年 | 65篇 |
2003年 | 65篇 |
2002年 | 70篇 |
2001年 | 72篇 |
2000年 | 70篇 |
1999年 | 49篇 |
1998年 | 29篇 |
1997年 | 31篇 |
1996年 | 34篇 |
1995年 | 27篇 |
1994年 | 17篇 |
1993年 | 22篇 |
1992年 | 58篇 |
1991年 | 38篇 |
1990年 | 42篇 |
1989年 | 32篇 |
1988年 | 37篇 |
1987年 | 37篇 |
1986年 | 32篇 |
1985年 | 32篇 |
1984年 | 35篇 |
1983年 | 28篇 |
1982年 | 22篇 |
1980年 | 18篇 |
1979年 | 16篇 |
1978年 | 26篇 |
1977年 | 21篇 |
1976年 | 14篇 |
1975年 | 26篇 |
1974年 | 22篇 |
1973年 | 18篇 |
1972年 | 23篇 |
1971年 | 20篇 |
1970年 | 15篇 |
1969年 | 14篇 |
1967年 | 16篇 |
1966年 | 20篇 |
1965年 | 14篇 |
排序方式: 共有2274条查询结果,搜索用时 0 毫秒
61.
Elizabeth F. Dowler Annette Diehl Peter Schmieder Christoph Brockmann Jonathan Elkins Meera Soundararajan Hartmut Oschkinat Linda J. Ball 《Biomolecular NMR assignments》2007,1(1):95-97
We have assigned 1H, 15N and 13C resonances of the RGS domain from the human RGS14 protein, a multi-domain member of the RGS (Regulators of G-protein signalling)
family of proteins, important in the down-regulation of specific G-protein signalling pathways. 相似文献
62.
J M Cherry C Adler C Ball S A Chervitz S S Dwight E T Hester Y Jia G Juvik T Roe M Schroeder S Weng D Botstein 《Nucleic acids research》1998,26(1):73-79
The Saccharomyces Genome Database (SGD) provides Internet access to the complete Saccharomyces cerevisiae genomic sequence, its genes and their products, the phenotypes of its mutants, and the literature supporting these data. The amount of information and the number of features provided by SGD have increased greatly following the release of the S.cerevisiae genomic sequence, which is currently the only complete sequence of a eukaryotic genome. SGD aids researchers by providing not only basic information, but also tools such as sequence similarity searching that lead to detailed information about features of the genome and relationships between genes. SGD presents information using a variety of user-friendly, dynamically created graphical displays illustrating physical, genetic and sequence feature maps. SGD can be accessed via the World Wide Web at http://genome-www.stanford.edu/Saccharomyces/ 相似文献
63.
64.
65.
In-depth mutational analysis of the promyelocytic leukemia zinc finger BTB/POZ domain reveals motifs and residues required for biological and transcriptional functions 总被引:12,自引:0,他引:12 下载免费PDF全文
Melnick A Ahmad KF Arai S Polinger A Ball H Borden KL Carlile GW Prive GG Licht JD 《Molecular and cellular biology》2000,20(17):6550-6567
66.
Identification of the Cu2+ binding sites in the N-terminal domain of the prion protein by EPR and CD spectroscopy 总被引:5,自引:0,他引:5
Aronoff-Spencer E Burns CS Avdievich NI Gerfen GJ Peisach J Antholine WE Ball HL Cohen FE Prusiner SB Millhauser GL 《Biochemistry》2000,39(45):13760-13771
Recent evidence indicates that the prion protein (PrP) plays a role in copper metabolism in the central nervous system. The N-terminal region of human PrP contains four sequential copies of the highly conserved octarepeat sequence PHGGGWGQ spanning residues 60-91. This region selectively binds divalent copper ions (Cu(2+)) in vivo. To elucidate the specific mode and site of binding, we have studied a series of Cu(2+)-peptide complexes composed of 1-, 2-, and 4-octarepeats and several sub-octarepeat peptides, by electron paramagnetic resonance (EPR, conventional X-band and low-frequency S-band) and circular dichroism (CD) spectroscopy. At pH 7.45, two EPR active binding modes are observed where the dominant mode appears to involve coordination of three nitrogens and one oxygen to the copper ion, while in the minor mode two nitrogens and two oxygens coordinate. ESEEM spectra demonstrate that the histidine imidazole contributes one of these nitrogens. The truncated sequence HGGGW gives EPR and CD that are indistinguishable from the dominant binding mode observed for the multi-octarepeat sequences and may therefore comprise the fundamental Cu(2+) binding unit. Both EPR and CD titration experiments demonstrate rigorously a 1:1 Cu(2+)/octarepeat binding stoichiometry regardless of the number of octarepeats in a given peptide sequence. Detailed spin integration of the EPR signals demonstrates that all of the bound Cu(2+) is detected thereby ruling out strong exchange coupling that is often found when there is imidazolate bridging between paramagnetic metal centers. A model consistent with these data is proposed in which Cu(2+) is bound to the nitrogen of the histidine imidazole side chain and to two nitrogens from sequential glycine backbone amides. 相似文献
67.
Background
Routine antibiotic prophylaxis following snakebite is not recommended but evidence suggests that it may be common practice in Zimbabwe. This study set out to determine and describe the extent of this practice at Parirenyatwa Hospital, a large teaching hospital in Zimbabwe 相似文献68.
Cerebral malaria (CM) can be a fatal manifestation of Plasmodium falciparum infection. In this study, two different approaches were used to examine the role of indoleamine 2,3-dioxygenase-1 (IDO-1) and its metabolites in the development of murine CM. Mice genetically deficient in IDO-1 were not protected against CM, but partial protection was observed in C57BL/6 mice treated with Ro 61-8048, an inhibitor of kynurenine-3-hydroxylase. This protection was associated with suppressed levels of picolinic acid (PA) within the brain, but not with changes in the levels of kynurenic acid (KA) or quinolinic acid (QA). These data suggest that although IDO-1 is not directly involved in the pathogenesis of CM in C57BL/6 mice, the production of the kynurenine pathway metabolite PA may contribute to the development of murine CM. 相似文献
69.
Baek MJ Park HM Johnson JM Altuntas CZ Jane-Wit D Jaini R Solares CA Thomas DM Ball EJ Robertson NG Morton CC Hughes GB Tuohy VK 《Journal of immunology (Baltimore, Md. : 1950)》2006,177(6):4203-4210
Autoimmune sensorineural hearing loss (ASNHL) is the most common cause of sudden hearing loss in adults. Although autoimmune etiopathogenic events have long been suspected in ASNHL, inner ear-specific Ags capable of targeting T cell autoreactivity have not been identified in ASNHL. In this study, we show by ELISPOT analysis that compared with normal hearing age- and sex-matched control subjects, ASNHL patients have significantly higher frequencies of circulating T cells producing either IFN-gamma (p = 0.0001) or IL-5 (p = 0.03) in response to recombinant human cochlin, the most abundant inner ear protein. In some patients, cochlin responsiveness involved both CD4+ and CD8+ T cells whereas other patients showed cochlin responsiveness confined to CD8+ T cells. ASNHL patients also showed significantly elevated cochlin-specific serum Ab titers compared with both normal hearing age- and sex-matched control subjects and patients with noise- and/or age-related hearing loss (p < 0.05 at all dilutions tested through 1/2048). Our study is the first to show T cell responsiveness to an inner ear-specific protein in ASNHL patients, and implicates cochlin as a prominent target Ag for mediating autoimmune inner ear inflammation and hearing loss. 相似文献
70.
Levels of extra‐pair paternity are associated with parental care in penduline tits (Remizidae) 下载免费PDF全文
Alex D. Ball René E. van Dijk Penn Lloyd Ákos Pogány Deborah A. Dawson Steve Dorus Rauri C. K. Bowie Terry Burke Tamás Székely 《Ibis》2017,159(2):449-455
In most passerine birds, individuals attempt to maximize their fitness by providing parental care while also mating outside their pair bond. A sex‐specific trade‐off between these two behaviours is predicted to occur, as the fitness benefits of extra‐pair mating differ between the sexes. We use nest observations and parentage analysis to reveal a negative association between male care and the incidence of extra‐pair paternity across three species of penduline tit (Remizidae). This provides evidence of a trade‐off between these two behaviours, possibly due to the devaluing of paternal care by extra‐pair offspring. 相似文献