全文获取类型
收费全文 | 1059篇 |
免费 | 101篇 |
国内免费 | 70篇 |
出版年
2024年 | 3篇 |
2023年 | 21篇 |
2022年 | 37篇 |
2021年 | 52篇 |
2020年 | 28篇 |
2019年 | 46篇 |
2018年 | 38篇 |
2017年 | 36篇 |
2016年 | 33篇 |
2015年 | 25篇 |
2014年 | 79篇 |
2013年 | 95篇 |
2012年 | 67篇 |
2011年 | 43篇 |
2010年 | 34篇 |
2009年 | 45篇 |
2008年 | 50篇 |
2007年 | 50篇 |
2006年 | 60篇 |
2005年 | 75篇 |
2004年 | 65篇 |
2003年 | 34篇 |
2002年 | 42篇 |
2001年 | 30篇 |
2000年 | 27篇 |
1999年 | 16篇 |
1998年 | 20篇 |
1997年 | 15篇 |
1996年 | 10篇 |
1995年 | 11篇 |
1994年 | 15篇 |
1993年 | 12篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有1230条查询结果,搜索用时 62 毫秒
41.
Nobuhiko?NaritaEmail author Yoshifumi?Nakahara Mamoru?Morimoto Ryosuke?Aoki Shigeru?Suda 《The International Journal of Life Cycle Assessment》2004,9(6):355-359
In 1998, the Japan’s Ministry of Economy, Trade, and Industry (METI) launched a five-year national project entitled ‘Development
of Life Cycle Impact Assessment for Products’ (commonly known as ‘the LCA Project’). The purpose of the project is to develop
common LCA methodology as well as a highly reliable database that can be shared in Japan. Activities over these five years
have resulted in the supply of LCI data on some 250 products. Industrial associations voluntarily provided data. The results
of these activities are currently being made available on the Internet on a trial basis in the form of an LCA database. In
addition, a method entitled ‘Life-cycle Impact assessment Method based on Endpoint modeling (LIME)’ was developed. It is expected
that these results will be widely used in Japan in the future. This paper presents an outline of the results of the research
and development that has been conducted in the LCA Project in Japan. 相似文献
42.
Fernandez S Katsuyama AM Kashiwabara AY Madeira AM Durham AM Gruber A 《FEMS microbiology letters》2004,238(1):183-188
This study reports the development and characterization of 151 sequence characterized amplified region (SCAR) markers for the seven Eimeria species that infect the domestic fowl. From this set, 84 markers are species-specific and 67 present partial specificity. The complete nucleotide sequence was derived for all markers, revealing the presence of micro- and minisatellite repetitive units in 22 SCARs, with up to five distinct repeat units being observed per marker. Only 15 markers showed significant hits in similarity searches against public sequence databases, thus confirming their anonymous and non-coding character. Finally, a relational database of the markers (the Eimeria SCARdb) was developed and made available on the Internet, providing a valuable resource of SCAR markers that can be useful for molecular diagnosis, and also for epizootiological, genetic variability and genome mapping studies. 相似文献
43.
Vector NTI, a balanced all-in-one sequence analysis suite 总被引:6,自引:0,他引:6
Vector NTI is a well-balanced desktop application integrated for molecular sequence analysis and biological data management. It has a centralised database and five application modules: Vector NTI, AlignX, BioAnnotator, ContigExpress and GenomBench. In this review, the features and functions available in this software are examined. These include database management, primer design, virtual cloning, alignments, sequence assembly, 3D molecular viewer and internet tools. Some problems encountered when using this software are also discussed. It is hoped that this review will introduce this software to more molecular biologists so they can make better-informed decisions when choosing computational tools to facilitate their everyday laboratory work. This tool can save time and enhance analysis but it requires some learning on the user's part and there are some issues that need to be addressed by the developer. 相似文献
44.
Database searching by flexible protein structure alignment 总被引:1,自引:0,他引:1
We have recently developed a flexible protein structure alignment program (FATCAT) that identifies structural similarity, at the same time accounting for flexibility of protein structures. One of the most important applications of a structure alignment method is to aid in functional annotations by identifying similar structures in large structural databases. However, none of the flexible structure alignment methods were applied in this task because of a lack of significance estimation of flexible alignments. In this paper, we developed an estimate of the statistical significance of FATCAT alignment score, allowing us to use it as a database-searching tool. The results reported here show that (1) the distribution of the similarity score of FATCAT alignment between two unrelated protein structures follows the extreme value distribution (EVD), adding one more example to the current collection of EVDs of sequence and structure similarities; (2) introducing flexibility into structure comparison only slightly influences the sensitivity and specificity of identifying similar structures; and (3) the overall performance of FATCAT as a database searching tool is comparable to that of the widely used rigid-body structure comparison programs DALI and CE. Two examples illustrating the advantages of using flexible structure alignments in database searching are also presented. The conformational flexibilities that were detected in the first example may be involved with substrate specificity, and the conformational flexibilities detected in the second example may reflect the evolution of structures by block building. 相似文献
45.
White SH 《Protein science : a publication of the Protein Society》2004,13(7):1948-1949
The rate of membrane protein (MP) structure determination has been examined for the 18-year period following the publication of the first high-resolution crystal structure. The growth is solidly exponential, but lags behind the rate for soluble proteins during the equivalent time period. 相似文献
46.
A new hybrid approach to predict subcellular localization of proteins by incorporating gene ontology 总被引:3,自引:0,他引:3
Based on the recent development in the gene ontology and functional domain databases, a new hybridization approach is developed for predicting protein subcellular location by combining the gene product, functional domain, and quasi-sequence-order effects. As a showcase, the same prokaryotic and eukaryotic datasets, which were studied by many previous investigators, are used for demonstration. The overall success rate by the jackknife test for the prokaryotic set is 94.7% and that for the eukaryotic set 92.9%. These are so far the highest success rates achieved for the two datasets by following a rigorous cross-validation test procedure, suggesting that such a hybrid approach may become a very useful high-throughput tool in the area of bioinformatics, proteomics, as well as molecular cell biology. The very high success rates also reflect the fact that the subcellular localization of a protein is closely correlated with: (1). the biological objective to which the gene or gene product contributes, (2). the biochemical activity of a gene product, and (3). the place in the cell where a gene product is active. 相似文献
47.
Selznick SH Thatcher ML Brown KS Haussler CA 《In vitro cellular & developmental biology. Animal》2001,37(1):55-61
Prototype computer software for a Cell Culture Laboratory Management System (CCLMS) has been developed to relieve cell culture specialists of the burden of manual recordkeeping. Conventional data archives in cell culture laboratories are prone to error and expensive to maintain. The reliance upon cell culture to provide models for biochemical and molecular biological research serves to magnify errors at great expense. The CCLMS prototype encapsulates a modular software application that manages the many aspects of cell culture laboratory recordkeeping. A transaction-based database stores detailed information on subcultures, freezes and thaws, prints waterproof labels for culture vessels, and provides for immediate historical trace-back of any cultured cell line. Linked database files store information specific to an individual culture flask while removing redundancy between similar groups of flasks. A frozen cell log maintains locations of all vials within any type of cryogenic storage unit, locates spaces for newly frozen cell lines, and generates alphabetical or numerical reports. Finally, modules for maintaining cell counts, user records, and culture vessel specifications to support a comprehensive automation process are incorporated within this software. The developed CCLMS prototype has been demonstrated to be an adaptable, reliable tool for improving training, efficiency, and historical rigor for two independent cell culture facilities. 相似文献
48.
Enormous amounts of data result from genome sequencing projects and new experimental methods. Within this tremendous amount of genomic data 30-40 per cent of the genes being identified in an organism remain unknown in terms of their biological function. As a consequence of this lack of information the overall schema of all the biological functions occurring in a specific organism cannot be properly represented. To understand the functional properties of the genomic data more experimental data must be collected. A pathway database is an effort to handle the current knowledge of biochemical pathways and in addition can be used for interpretation of sequence data. Some of the existing pathway databases can be interpreted as detailed functional annotations of genomes because they are tightly integrated with genomic information. However, experimental data are often lacking in these databases. This paper summarises a list of pathway databases and some of their corresponding biological databases, and also focuses on information about the content and the structure of these databases, the organisation of the data and the reliability of stored information from a biological point of view. Moreover, information about the representation of the pathway data and tools to work with the data are given. Advantages and disadvantages of the analysed databases are pointed out, and an overview to biological scientists on how to use these pathway databases is given. 相似文献
49.
50.
X-ray crystallography and bioinformatics studies reveal a tendency for the right-handed β-helix domain architecture to be associated with carbohydrate binding proteins. Here we demonstrate the presence of catalytic β-helix domains in glycoside hydrolase (GH) families 49, 55 and 87 and provide evidence for their sharing a common evolutionary ancestor with two structurally characterized GH families, numbers 28 and 82. This domain assignment helps assign catalytic residues to each family. Further analysis of domain architecture reveals the association of carbohydrate binding modules with catalytic GH β-helices, as well as an unexpected pair of β-helix domains in GH family 55. 相似文献