全文获取类型
收费全文 | 815篇 |
免费 | 69篇 |
国内免费 | 77篇 |
专业分类
961篇 |
出版年
2023年 | 8篇 |
2022年 | 18篇 |
2021年 | 22篇 |
2020年 | 23篇 |
2019年 | 28篇 |
2018年 | 22篇 |
2017年 | 18篇 |
2016年 | 24篇 |
2015年 | 30篇 |
2014年 | 48篇 |
2013年 | 66篇 |
2012年 | 22篇 |
2011年 | 32篇 |
2010年 | 27篇 |
2009年 | 48篇 |
2008年 | 51篇 |
2007年 | 49篇 |
2006年 | 58篇 |
2005年 | 52篇 |
2004年 | 38篇 |
2003年 | 45篇 |
2002年 | 26篇 |
2001年 | 28篇 |
2000年 | 16篇 |
1999年 | 28篇 |
1998年 | 22篇 |
1997年 | 21篇 |
1996年 | 10篇 |
1995年 | 15篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 18篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1985年 | 4篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有961条查询结果,搜索用时 0 毫秒
1.
Conformation of P22 tailspike folding and aggregation intermediates probed by monoclonal antibodies. 总被引:3,自引:2,他引:1 下载免费PDF全文
M. A. Speed T. Morshead D. I. Wang J. King 《Protein science : a publication of the Protein Society》1997,6(1):99-108
The partitioning of partially folded polypeptide chains between correctly folded native states and off-pathway inclusion bodies is a critical reaction in biotechnology. Multimeric partially folded intermediates, representing early stages of the aggregation pathway for the P22 tailspike protein, have been trapped in the cold and isolated by nondenaturing polyacrylamide gel electrophoresis (PAGE) (speed MA, Wang DIC, King J. 1995. Protein Sci 4:900-908). Monoclonal antibodies against tailspike chains discriminate between folding intermediates and native states (Friguet B, Djavadi-Ohaniance L, King J, Goldberg ME. 1994. J Biol Chem 269:15945-15949). Here we describe a nondenaturing Western blot procedure to probe the conformation of productive folding intermediates and off-pathway aggregation intermediates. The aggregation intermediates displayed epitopes in common with productive folding intermediates but were not recognized by antibodies against native epitopes. The nonnative epitope on the folding and aggregation intermediates was located on the partially folded N-terminus, indicating that the N-terminus remained accessible and nonnative in the aggregated state. Antibodies against native epitopes blocked folding, but the monoclonal directed against the N-terminal epitope did not, indicating that the conformation of the N-terminus is not a key determinant of the productive folding and chain association pathway. 相似文献
2.
3.
A monoclonal antibody produced by hydridoma cell line, ATCC HB8209, was used to detect and purify erythropoietin synthesized in a cell-free system. The antibody was raised against the N-terminal 20 residues of erythropoietin. It retained anti-erythropoietin activity in 6 M urea in which most of the cell-free synthesized erythropoietin became soluble and gave an enhanced activity of the antibody. 相似文献
4.
Andrea Bazzoli David J. Vance Michael J. Rudolph Yinghui Rong Siva Krishna Angalakurthi Ronald T. Toth IV C. Russell Middaugh David B. Volkin David D. Weis John Karanicolas Nicholas J. Mantis 《Proteins》2017,85(11):1994-2008
In this report we investigated, within a group of closely related single domain camelid antibodies (VHHs), the relationship between binding affinity and neutralizing activity as it pertains to ricin, a fast‐acting toxin and biothreat agent. The V1C7‐like VHHs (V1C7, V2B9, V2E8, and V5C1) are similar in amino acid sequence, but differ in their binding affinities and toxin‐neutralizing activities. Using the X‐ray crystal structure of V1C7 in complex with ricin's enzymatic subunit (RTA) as a template, Rosetta‐based homology modeling coupled with energetic decomposition led us to predict that a single pairwise interaction between Arg29 on V5C1 and Glu67 on RTA was responsible for the difference in ricin toxin binding affinity between V1C7, a weak neutralizer, and V5C1, a moderate neutralizer. This prediction was borne out experimentally: substitution of Arg for Gly at position 29 enhanced V1C7's binding affinity for ricin, whereas the reverse (ie, Gly for Arg at position 29) diminished V5C1's binding affinity by >10 fold. As expected, the V5C1R29G mutant was largely devoid of toxin‐neutralizing activity (TNA). However, the TNA of the V1C7G29R mutant was not correspondingly improved, indicating that in the V1C7 family binding affinity alone does not account for differences in antibody function. V1C7 and V5C1, as well as their respective point mutants, recognized indistinguishable epitopes on RTA, at least at the level of sensitivity afforded by hydrogen‐deuterium mass spectrometry. The results of this study have implications for engineering therapeutic antibodies because they demonstrate that even subtle differences in epitope specificity can account for important differences in antibody function. 相似文献
5.
Outer membrane proteins (OMPs) of pathogenic bacteria have been used as protective antigens in developing bacterial vaccines. In the present study, we compared the antibody responses to a Pseudomonas aeruginosa OMP vaccine elicited in humans and rabbits by immunization. Immunization with the vaccine induced high titers of serum IgG antibody both in rabbits and humans but reactivities of the induced antibodies with the OMPs were different. The rabbit immune sera recognized most of the OMPs in the vaccine both in immunoblot and immunoprecipitation analyses. In contrast, a great variation in band pattern and intensity was observed among the human immune sera in immunoblot analysis, but not in immunoprecipitation analysis. Denaturation of the OMPs did not affect the binding activity of the rabbit immune sera as determined by ELISA, but substantially reduced those of the human immune sera and anti-OMP IgG purified from a pooled normal human plasma. These data suggest that antibody response to P. aeruginosa OMPs elicited by immunization in humans is mainly directed against discontinuous or conformation-dependent epitopes, which should be taken into account in developing vaccines, especially for OMP-derived synthetic peptides. 相似文献
6.
Nakao H Kataoka C Kiyokawa N Fujimoto J Yamasaki S Takeda T 《Microbiology and immunology》2002,46(11):777-780
A monoclonal antibody, 5-5B, which neutralizes Shiga toxin 1 (Stx1) cytotoxicity of Escherichia coli, was constructed. An epitope analysis indicated that Asn55 in Stx1 B subunit was an important residue. This result and our previous results using an anti-Stx2 monoclonal antibody indicate that the region around the cysteine residue of the disulfide bond might be important for the neutralization of Stx cytotoxicity, making it a potential vaccination candidate. 相似文献
7.
Induction of multiple cytotoxic T lymphocyte responses in mice by a multiepitope DNA vaccine against dengue virus serotype 1 下载免费PDF全文
Xin Yu Chen De Zhou Li Xiao Zhi Zhong Bokun Chen Zhi Liang Duan Jin Sheng Wen 《Microbiology and immunology》2016,60(12):835-845
8.
SARS病毒M蛋白的二级结构和B细胞表位预测 总被引:4,自引:0,他引:4
以SARS病毒基因组序列为基础,采用GarnierRobson方法、ChouFasman方法和KarplusSchulz方法预测蛋白质的二级结构;按KyteDoolittle方案、Emini方案和JamesonWolf方案预测SARS病毒M蛋白的B细胞表位。预测结果表明,在SARS病毒M蛋白N端第11~20、27~36区段和第133~141区段可能是α螺旋中心;M蛋白分子N端第20~27、34~37,44~56,61~64,70~76,79~97,117~132,142~147,165~176区段和第216~221区段可能是β折叠中心。在M蛋白N端第5~6、40~44、105~107、112~116、189~190、202~203区段和第210~215区段具有较柔软的结构,有可能进行一定幅度的摆动或折叠而形成较复杂的三级结构。SARS病毒M蛋白N端第1~15、37~47、99~120、181~192区段和第196~215区段内或附近很可能是B细胞表位优势区域。以蛋白质的二级结构预测作为辅助手段,用抗原指数,亲水性参数和可及性参数预测SARS冠状病毒M蛋白的B细胞表位,为实验确定SARS病毒M蛋白的B细胞表位和免疫识别研究奠定了基础 。 相似文献
9.
Roy Jefferis 《MABS-AUSTIN》2013,5(5):638-640
The glycoform profile of a glycoprotein is non-templated, i.e., is not encoded within the genome or otherwise predetermined; however, it is estimated that ~50% of human genes having an open reading frame encode a –N-X-S/T- amino acid sequence, where X represents any amino acid other than proline, that comprises a potential site (sequon) for N-linked glycosylation of the translated protein. N-linked glycosylation is both a co- and post-translational modification. The complex oligosaccharide GlcNAc2Man9Glu3 may be added at a –N-X-S/T- sequon as the polypeptide chain emerges from the ribosome tunnel. Local secondary structure determines whether oligosaccharide is added and the extent of addition. Higher occupancy is observed for –N-X-T- sequons than at –N-X-S- sequons, and the efficiency of addition can be further influenced by adjacent amino acid residues. 相似文献
10.
《Biotechnic & histochemistry》2013,88(5):207-215
AbstractThe overwhelming majority of antibodies useful for formalin fixed, paraffin embedded (FFPE) tissues require antigen retrieval to reverse the effect of formalin fixation and re-establish immunoreactivity. How this reversal happens is poorly understood. We developed a new experimental model for studying the mechanism of formalin fixation and antigen retrieval. Epitope mapping studies on nine antibodies useful for FFPE tissues revealed that each consisted of a contiguous stretch of amino acids in the native protein (linear epitope). Small peptides representing the epitopes of antibodies to human epidermal growth factor receptor type (HER2), estrogen, and progesterone receptors were attached covalently to glass microscope slides in a peptide array. Most peptides retained immunoreactivity after formalin fixation. Immunoreactivity was completely abrogated for all peptides, however, if an irrelevant large protein was present during formalin-induced cross-linking. We hypothesize that cross-linking the irrelevant protein to the peptide epitopes sterically blocked antibodies from binding. Antigen retrieval dissociates irrelevant proteins and restores immunoreactivity. Because the epitopes for clinical antibodies require only primary protein structure, the fact that antigen retrieval probably denatures the secondary and tertiary structure of the protein is irrelevant. The same mechanism may occur in tissue samples subjected to formalin fixation and antigen retrieval. 相似文献