全文获取类型
收费全文 | 17818篇 |
免费 | 1299篇 |
国内免费 | 3篇 |
专业分类
19120篇 |
出版年
2021年 | 112篇 |
2020年 | 103篇 |
2019年 | 99篇 |
2018年 | 284篇 |
2017年 | 247篇 |
2016年 | 429篇 |
2015年 | 763篇 |
2014年 | 693篇 |
2013年 | 1030篇 |
2012年 | 1238篇 |
2011年 | 1201篇 |
2010年 | 710篇 |
2009年 | 547篇 |
2008年 | 1080篇 |
2007年 | 1071篇 |
2006年 | 1038篇 |
2005年 | 992篇 |
2004年 | 899篇 |
2003年 | 850篇 |
2002年 | 787篇 |
2001年 | 404篇 |
2000年 | 430篇 |
1999年 | 357篇 |
1998年 | 146篇 |
1997年 | 129篇 |
1996年 | 112篇 |
1995年 | 128篇 |
1994年 | 112篇 |
1993年 | 85篇 |
1992年 | 216篇 |
1991年 | 220篇 |
1990年 | 195篇 |
1989年 | 154篇 |
1988年 | 169篇 |
1987年 | 140篇 |
1986年 | 135篇 |
1985年 | 126篇 |
1984年 | 112篇 |
1983年 | 92篇 |
1982年 | 86篇 |
1981年 | 107篇 |
1980年 | 74篇 |
1979年 | 107篇 |
1978年 | 102篇 |
1977年 | 81篇 |
1976年 | 93篇 |
1975年 | 80篇 |
1974年 | 91篇 |
1973年 | 68篇 |
1971年 | 76篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
I Bernier A Dautigny J Jollès J Colombani P Jollès 《Biochimica et biophysica acta》1978,533(2):355-361
Two glycoproteins characterized by their serological activities (HLA-A9 and HLA-B12), their isoelectric points and their molecular weights were purified from urine from a patient suffering from tubular proteinuria (cystinosis). Their physicochemical properties as well as an important increase of their specific activities during the different purification steps suggested that they behave as human leucocyte antigens (HLA) which had been excreted into urine. Their amino acid compositions and N-terminal sequences were different to those described for HLA solubilized from cultured human lymphoblast cell lines. The N-terminal sequences of the two serologically active glycoproteins were identical to the N-terminal sequence of another recently purified human urinary glycoprotein called human complex-forming glycoprotein. The relationship between HLA, human complex-forming glycoprotein and the serologically active urinary glycoproteins is discussed. 相似文献
73.
The secondary structures of cow and sheep kappa-caseins were established according to the predictive rules of Chou and Fasman. The diagrams derived from this treatment allowed us to study the chymosin sensitive bond (milk-clotting process), as well as the glycosylation and phosphorylation sites, found to be situated in beta-turns. Despite a high variability between the primary structures of the COOH-terminal part (caseinoglycopeptide) of cow, sheep, and also other caseins, the secondary structures of the biologically important sites were found to be conserved. 相似文献
74.
75.
Umberto Tomati Giovanni Giovannozzi-Sermanni Silvestro Duprè Carlo Cannella 《Phytochemistry》1976,15(5):597-598
The NADH: nitrate reductase from durum wheat leaves was inactivated by cyanide and its activity restored by thiosulphate and beef kidney rhodanese. Rhodanese and thiosulphate, added to NADH-nitrate reductase before cyanide treatment protected NADH-nitrate reductase activity. No oxidizing agent was required for the protection or restoration of cyanide treated NADH-nitrate reductase. 相似文献
76.
A Scheen J Juchmès G Lennes J Lecomte 《Archives internationales de physiologie et de biochimie》1976,84(5):915-923
VO2 max, maximum oxygen uptake, has been measured in 4 normal young men, before and after beta-adrenergic blockade (0.5 to 5 mg Pindolol by mouth). Pindolol induces bradycardia and reduces VO2 max. A statistically significant positive correlation appears between posology of Pindolol and bradycardia, this posology and reduction of VO2 max, and finally between bradycardia and reduction of VO2 max. These correlations indicate that the reduction of VO2 max is best explained by a circulatory limitation of oxygen supply to active muscles. 相似文献
77.
78.
79.
J. Poulton M. Hirano A. Spinazzola M. Arenas Hernandez C. Jardel A. Lombès B. Czermin R. Horvath J.W. Taanman A. Rotig M. Zeviani C. Fratter 《生物化学与生物物理学报:疾病的分子基础》2009,1792(12):1109-1112
These tables list both published and a number of unpublished mutations in genes associated with early onset defects in mitochondrial DNA (mtDNA) maintenance including C10orf2, SUCLG1, SUCLA2, TYMP, RRM2B, MPV17, DGUOK and TK2. The list should not be taken as evidence that any particular mutation is pathogenic. We have included genes known to cause mtDNA depletion, excluding POLG1, because of the existing database (http://tools.niehs.nih.gov/polg/). We have also excluded mutations in C10orf2 associated with dominant adult onset disorders. 相似文献
80.
Dodier Y Banderali U Klein H Topalak O Dafi O Simoes M Bernatchez G Sauvé R Parent L 《The Journal of biological chemistry》2004,279(8):6853-6862
The substituted cysteine accessibility method (SCAM) was used to map the external vestibule and the pore region of the ECaC-TRPV5 calcium-selective channel. Cysteine residues were introduced at 44 positions from the end of S5 (Glu515) to the beginning of S6 (Ala560). Covalent modification by positively charged MTSET applied from the external medium significantly inhibited whole cell currents at 15/44 positions. Strongest inhibition was observed in the S5-linker to pore region (L520C, G521C, and E522C) with either MTSET or MTSES suggesting that these residues were accessible from the external medium. In contrast, the pattern of covalent modification by MTSET for residues between Pro527 and Ile541 was compatible with the presence of a alpha-helix. The absence of modification by the negatively charged MTSES in that region suggests that the pore region has been optimized to favor the entrance of positively charged ions. Cysteine mutants at positions -1, 0, +1, +2 around Asp542 (high Ca2+ affinity site) were non-functional. Whole cell currents of cysteine mutants at +4 and +5 positions were however covalently inhibited by external MTSET and MTSES. Altogether, the pattern of covalent modification by MTS reagents globally supports a KcsA homology-based three-dimensional model whereby the external vestibule in ECaC-TRPV5 encompasses three structural domains consisting of a coiled structure (Glu515 to Tyr526) connected to a small helical segment of 15 amino acids (527PTALFSTFELFLT539) followed by two distinct coiled structures Ile540-Pro544 (selectivity filter) and Ala545-Ile557 before the beginning of S6. 相似文献