全文获取类型
收费全文 | 1598篇 |
免费 | 99篇 |
出版年
2023年 | 10篇 |
2022年 | 18篇 |
2021年 | 40篇 |
2020年 | 21篇 |
2019年 | 31篇 |
2018年 | 31篇 |
2017年 | 23篇 |
2016年 | 48篇 |
2015年 | 56篇 |
2014年 | 69篇 |
2013年 | 105篇 |
2012年 | 106篇 |
2011年 | 85篇 |
2010年 | 63篇 |
2009年 | 65篇 |
2008年 | 73篇 |
2007年 | 77篇 |
2006年 | 87篇 |
2005年 | 57篇 |
2004年 | 57篇 |
2003年 | 61篇 |
2002年 | 52篇 |
2001年 | 47篇 |
2000年 | 43篇 |
1999年 | 31篇 |
1998年 | 12篇 |
1997年 | 10篇 |
1996年 | 12篇 |
1995年 | 10篇 |
1994年 | 14篇 |
1992年 | 24篇 |
1991年 | 16篇 |
1990年 | 22篇 |
1989年 | 32篇 |
1988年 | 9篇 |
1987年 | 15篇 |
1986年 | 13篇 |
1985年 | 11篇 |
1984年 | 8篇 |
1983年 | 12篇 |
1982年 | 11篇 |
1981年 | 12篇 |
1979年 | 11篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 12篇 |
1975年 | 11篇 |
1970年 | 6篇 |
1968年 | 8篇 |
1966年 | 5篇 |
排序方式: 共有1697条查询结果,搜索用时 156 毫秒
51.
Mathur Sunil Turnbull Agnes Akaev Iolia Stevens Craig Agrawal Neerja Chopra Mridula Mincher David 《International journal of peptide research and therapeutics》2020,26(4):1965-1980
International Journal of Peptide Research and Therapeutics - The lysosomal endoprotease legumain (asparaginyl endoprotease) has been proposed as a putative biomarker in prostate tumours, in which... 相似文献
52.
53.
Serum C-reactive protein (CRP) is used as a marker of inflammation in several diseases including autoimmune disease and cardiovascular disease. CRP, a member of the pentraxin family, is comprised of five identical subunits. CRP has diverse ligand-binding properties which depend upon different structural states of CRP. However, little is known about the molecular dynamics and interaction properties of CRP. In this study, we used SAPS, SCRATCH protein predictor, PDBsum, ConSurf, ProtScale, Drawhca, ASAView, SCide and SRide server and performed comprehensive analyses of molecular dynamics, protein–protein and residue–residue interactions of CRP. We used 1GNH.pdb file for the crystal structure of human CRP which generated two pentamers (ABCDE and FGHIJ). The number of residues involved in residue–residue interactions between A–B, B–C, C–D, D–E, F–G, G–H, H–I, I–J, A–E and F–J subunits were 12, 11, 10, 11, 12, 11, 10, 11, 10 and 10, respectively. Fifteen antiparallel β sheets were involved in β-sheet topology, and five β hairpins were involved in forming the secondary structure. Analysis of hydrophobic segment distribution revealed deviations in surface hydrophobicity at different cavities present in CRP. Approximately 33 % of all residues were involved in the stabilization centers. We show that the bioinformatics tools can provide a rapid method to predict molecular dynamics and interaction properties of CRP. Our prediction of molecular dynamics and interaction properties of CRP combined with the modeling data based on the known 3D structure of CRP is helpful in designing stable forms of CRP mutants for structure–function studies of CRP and may facilitate in silico drug design for therapeutic targeting of CRP. 相似文献
54.
M. Rajeswari Pushpa Agrawal S. Pavithra Priya G. R. Sandhya G. M. Pavithra 《Biotechnology and Bioprocess Engineering》2013,18(2):321-325
The biosorption of Cd(II) by Moringa oleifera using a batch system and a continuous up flow mode in a fixed bed column was studied. Batch adsorption experiments were performed as a function of pH, biosorbent dose, contact time, volume of the solution, and initial metal concentration. The adsorption isotherms obtained fitted well into the Freundlich and Langmuir isotherms. The dynamic removal of cadmium by powdered seed of the Moringa oleifera was studied in a packed column. The effect of bed height (4 and 8 cm) and flow rate (2 and 5mL/min) on biosorption process was investigated and the experimental breakthrough curves were obtained. Results showed that by increasing the bed height and decreasing the flow rate, the breakthrough and exhaustion times increased. The break-through time was considered as a measure of the column performance. The maximum break-through time of 320 min was achieved at the operating condition of 2 mL/min influent flow rate and bed height of 8 cm. 相似文献
55.
Ekambar R. Kandimalla Jamal Temsamani Sudhir Agrawal 《Nucleosides, nucleotides & nucleic acids》2013,32(3-5):1031-1035
Abstract 2′-O-methylribonucleoside methylphosphonamidites are synthesized and incorporated into oligonucleotides to obtain chimeric antisense oligonucleotides. The resulting oligonucleotide binds to their target RNA/DNA sequences efficiently and stable in a medium containing bovine serum. 相似文献
56.
Abstract An oligodeoxynucleotide designed to bind to a single stranded guanine rich DNA sequence through Watson-Crick followed by Hoogsteen hydrogen bonds was found to destabilize quadruplex structure formed by the target sequence. However, the conventional antisense and antigene oligonucleotides were unable to destabilize the same quadruplex structure. 相似文献
57.
Abstract Synthesis of 2′-deoxy-2′,3′-secothymidine t and its dimer t?t, where the two 2′-deoxy-2′,3′-secothymidine t units are connected via a carbamate, ?=3′-NH-CO-O-5′, internucleoside linkage has been achieved. These building blocks were protected in the 5′-position, converted into their phosphoramidites, or attached onto CPG, and then used for “chimeric oligonucleotide” synthesis. 相似文献
58.
Sudhir Agrawal Zhiwei Jiang Qiuyan Zhao Denise Shaw Daisy Sun Carl Saxinger 《Nucleosides, nucleotides & nucleic acids》2013,32(7-9):927-936
Abstract Antisense oligonucleotides are being studied as novel therapeutic agents. To further improve the properties of antisense oligonucleotides, we have synthesized phosphorothioate oligonucleotides containing methylphosphonate linkages at the 5′-end, the 3′-end, or in the center, and have evaluated the impact of these linkages on the biophysical properties, biological properties, and some of the safety parameters. 相似文献
59.
Plant defensins are small (45 to 54 amino acids) positively charged antimicrobial peptides produced by the plant species, which can inhibit the growth of a broad range of fungi at micro-molar concentrations. These basic peptides share a common characteristic three-dimensional folding pattern with one α-helix and three β-sheets that are stabilized by eight disulfide-linked cysteine residues. Instead of using two single-gene constructs, it is beneficial when two effective genes are made into a single fusion gene with one promoter and terminator. In this approach, we have linked two plant defensins namely Trigonella foenum-graecum defensin 2 (Tfgd2) and Raphanus sativus antifungal protein 2 (RsAFP2) genes by a linker peptide sequence (occurring in the seeds of Impatiens balsamina) and made into a single-fusion gene construct. We used pET-32a+ vector system to express Tfgd2-RsAFP2 fusion gene with hexahistidine tag in Escherichia coli BL21 (DE3) pLysS cells. Induction of these cells with 1 mM IPTG achieved expression of the fusion protein. The solubilized His6-tagged recombinant fusion protein was purified by immobilized-metal (Ni2+) affinity column chromatography. The final yield of the fusion protein was 500 ng/μL. This method produced biologically active recombinant His6-tagged fusion protein, which exhibited potent antifungal action towards the plant pathogenic fungi (Botrytis cinerea, Fusarium moniliforme, Fusarium oxysporum, Phaeoisariopsis personata and Rhizoctonia solani along with an oomycete pathogen Phytophthora parasitica var nicotianae) at lower concentrations under in vitro conditions. This strategy of combining activity of two defensin genes into a single-fusion gene will definitely be a promising utility for biotechnological applications. 相似文献
60.