全文获取类型
收费全文 | 2210篇 |
免费 | 443篇 |
国内免费 | 14篇 |
学科分类
工业技术 | 2667篇 |
出版年
2024年 | 12篇 |
2023年 | 85篇 |
2022年 | 88篇 |
2021年 | 183篇 |
2020年 | 121篇 |
2019年 | 195篇 |
2018年 | 142篇 |
2017年 | 123篇 |
2016年 | 122篇 |
2015年 | 137篇 |
2014年 | 101篇 |
2013年 | 146篇 |
2012年 | 184篇 |
2011年 | 211篇 |
2010年 | 132篇 |
2009年 | 130篇 |
2008年 | 106篇 |
2007年 | 115篇 |
2006年 | 88篇 |
2005年 | 71篇 |
2004年 | 44篇 |
2003年 | 44篇 |
2002年 | 27篇 |
2001年 | 8篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1980年 | 2篇 |
排序方式: 共有2667条查询结果,搜索用时 15 毫秒
11.
Christine Schlmmer Anna Brandtner Mirjam Bachler 《International journal of molecular sciences》2021,22(8)
Antithrombin (AT) is a natural anticoagulant that interacts with activated proteases of the coagulation system and with heparan sulfate proteoglycans (HSPG) on the surface of cells. The protein, which is synthesized in the liver, is also essential to confer the effects of therapeutic heparin. However, AT levels drop in systemic inflammatory diseases. The reason for this decline is consumption by the coagulation system but also by immunological processes. Aside from the primarily known anticoagulant effects, AT elicits distinct anti-inflammatory signaling responses. It binds to structures of the glycocalyx (syndecan-4) and further modulates the inflammatory response of endothelial cells and leukocytes by interacting with surface receptors. Additionally, AT exerts direct antimicrobial effects: depending on AT glycosylation it can bind to and perforate bacterial cell walls. Peptide fragments derived from proteolytic degradation of AT exert antibacterial properties. Despite these promising characteristics, therapeutic supplementation in inflammatory conditions has not proven to be effective in randomized control trials. Nevertheless, new insights provided by subgroup analyses and retrospective trials suggest that a recommendation be made to identify the patient population that would benefit most from AT substitution. Recent experiment findings place the role of various AT isoforms in the spotlight. This review provides an overview of new insights into a supposedly well-known molecule. 相似文献
12.
Dawei Ji Jingying Ma Min Xu Dominic Agyei 《Comprehensive Reviews in Food Science and Food Safety》2021,20(1):369-400
Proteins displayed on the cell surface of lactic acid bacteria (LAB) perform diverse and important biochemical roles. Among these, the cell-envelope proteinases (CEPs) are one of the most widely studied and most exploited for biotechnological applications. CEPs are important players in the proteolytic system of LAB, because they are required by LAB to degrade proteins in the growth media into peptides and/or amino acids required for the nitrogen nutrition of LAB. The most important area of application of CEPs is therefore in protein hydrolysis, especially in dairy products. Also, the physical location of CEPs (i.e., being cell-envelope anchored) allows for relatively easy downstream processing (e.g., extraction) of CEPs. This review describes the biochemical features and organization of CEPs and how this fits them for the purpose of protein hydrolysis. It begins with a focus on the genetic organization and expression of CEPs. The catalytic behavior and cleavage specificities of CEPs from various LAB are also discussed. Following this, the extraction and purification of most CEPs reported to date is described. The industrial applications of CEPs in food technology, health promotion, as well as in the growing area of water purification are discussed. Techniques for improving the production and catalytic efficiency of CEPs are also given an important place in this review. 相似文献
13.
Dr. Ma Su Dr. Yan Shi Minghui Wang Ruixuan Gao Jianfeng Wu Hai Xu Chuanwu Xi Prof. Jianfeng Cai 《ChemMedChem》2019,14(23):1963-1967
Host Defense Peptides (HDPs) have gained considerable interest due to the omnipresent threat of bacterial infection as a serious public health concern. However, development of HDPs is impeded by several drawbacks, such as poor selectivity, susceptibility to proteolytic degradation, low-to-moderate activity and requiring complex syntheses. Herein we report a class of lipo-linear α/urea-γ-AApeptides with a hybrid backbone and low molecular weight. The heterogeneous backbone not only enhances chemodiversity, but also shows effective antimicrobial activity against Gram-positive bacteria and is capable of disrupting bacterial membranes and killing bacteria rapidly. Given their low molecular weight and ease of access via facile synthesis, they could be practical antibiotic agents. 相似文献
14.
Dr. Héctor Zamora-Carreras Dr. Beatriz Maestro Dr. Jesús M. Sanz Dr. M. Angeles Jiménez 《Chembiochem : a European journal of chemical biology》2020,21(4):432-441
A common interpretation of Anfinsen's hypothesis states that one amino acid sequence should fold into a single, native, ordered state, or a highly similar set thereof, coinciding with the global minimum in the folding-energy landscape, which, in turn, is responsible for the function of the protein. However, this classical view is challenged by many proteins and peptide sequences, which can adopt exchangeable, significantly dissimilar conformations that even fulfill different biological roles. The similarities and differences of concepts related to these proteins, mainly chameleon sequences, metamorphic proteins, and switch peptides, which are all denoted herein “turncoat” polypeptides, are reviewed. As well as adding a twist to the conventional view of protein folding, the lack of structural definition adds clear versatility to the activity of proteins and can be used as a tool for protein design and further application in biotechnology and biomedicine. 相似文献
15.
Wai Ling Cheung-Lee Madison E. Parry Dr. Chuhan Zong Alexis Jaramillo Cartagena Prof. Seth A. Darst Prof. Nancy D. Connell Dr. Riccardo Russo Prof. A. James Link 《Chembiochem : a European journal of chemical biology》2020,21(9):1335-1340
We report the heterologous expression, structure, and antimicrobial activity of a lasso peptide, ubonodin, encoded in the genome of Burkholderia ubonensis. The topology of ubonodin is unprecedented amongst lasso peptides, with 18 of its 28 amino acids found in the mechanically bonded loop segment. Ubonodin inhibits RNA polymerase in vitro and has potent antimicrobial activity against several pathogenic members of the Burkholderia genus, most notably B. cepacia and B. multivorans, causative agents of lung infections in cystic fibrosis patients. 相似文献
16.
17.
18.
19.
Sayuri L. Higashi Normazida Rozi Sharina Abu Hanifah Masato Ikeda 《International journal of molecular sciences》2020,21(24)
Supramolecular architectures that are built artificially from biomolecules, such as nucleic acids or peptides, with structural hierarchical orders ranging from the molecular to nano-scales have attracted increased attention in molecular science research fields. The engineering of nanostructures with such biomolecule-based supramolecular architectures could offer an opportunity for the development of biocompatible supramolecular (nano)materials. In this review, we highlighted a variety of supramolecular architectures that were assembled from both nucleic acids and peptides through the non-covalent interactions between them or the covalently conjugated molecular hybrids between them. 相似文献