全文获取类型
收费全文 | 370篇 |
免费 | 22篇 |
专业分类
392篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 9篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 24篇 |
2014年 | 20篇 |
2013年 | 19篇 |
2012年 | 35篇 |
2011年 | 28篇 |
2010年 | 22篇 |
2009年 | 18篇 |
2008年 | 10篇 |
2007年 | 22篇 |
2006年 | 16篇 |
2005年 | 9篇 |
2004年 | 14篇 |
2003年 | 10篇 |
2002年 | 9篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1996年 | 2篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1991年 | 2篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1971年 | 6篇 |
1970年 | 5篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1963年 | 1篇 |
1960年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有392条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
5.
Bacillus subtilis genome project: cloning and sequencing of the 97 kb region from 325° to 333deg; 总被引:2,自引:2,他引:0
P. Glaser F. Kunst M. Arnaud M.-P. Coudart W. Gonzales M.-F. Hullo M. Ionescu B. Lubochinsicy L. Marcelino I. Moszer E. Presecan M. Santana E. Schneider J. Schwelzer A. Vertes G. Rapoport A. Danchin 《Molecular microbiology》1993,10(2):371-384
In the framework of the European project aimed at the sequencing of the Bacillus subtilis genome the DNA region located between gerB (314°) and sacXV (333°) was assigned to the Institut Pasteur. In this paper we describe the cloning and sequencing of a segment of 97 kb of contiguous DNA. Ninety-two open reading frames were predicted to encode putative proteins among which only forty-two were found to display significant similarities to known proteins present in databanks, e.g. amino acid permeases, proteins involved in cell wall or antibiotic biosynthesis, various regulatory proteins, proteins of several dehydrogenase families and enzymes II of the phosphotransferase system involved in sugar transport. Additional experiments led to the identification of the products of new B. subtilis genes, e.g. galactokinase and an operon involved in thiamine biosynthesis. 相似文献
6.
7.
C T Dragomir A Barbier D Ungureanu V Ionescu E Pausescu R Chirvasie D Ghitescu G Filipescu 《Physiological chemistry and physics》1975,7(4):287-308
Investigation of the ionic behavior of glycerinated muscle fibers showed that the residual structures of this biologic cellular material, lacking functional membranes, are able to discriminate between alkaline ions. The characteristics of the ionic selectivity of the glycerinated fibers change with their functional state and with the presence in the medium of certain nonionic substances. Among the more important features of ionic distribution between the membrane-free fibers and the medium are the following: (1) There is evident adsorption of potassium on the fibers, in the absence of ATP. (2) This adsorption increases in contraction and decreases in relaxation. (3) At high ionic concentrations, in contrast to what occurs at low potassium concentrations, the glycerinated muscle prefers sodium to potassium, but even under these conditions both ions are accumulated in the fibers to far greater levels than in the medium. This strongly suggests a Donnan ionic equilibrium developing parallel to the adsorption process. (4) Nonionic substances of the general anesthetic group markedly alter the ionic selectivity of the glycerinated fibers, probably by their action on the water's physical state. A mechanism is proposed for the observed ionic adsorption specific of the muscle-a mechanism in which actin-myosin coupling plays the cardinal adsorption role. In the general interpretation of the data a synthetic concept is advanced according to which an entire set of processes and factors concurs with the distribution of ions between the muscle and the medium. 相似文献
8.
Tadashi Yasuda Elena Tchetina Kunitaka Ohsawa Peter J Roughley William Wu Aisha Mousa Mirela Ionescu Isabelle Pidoux A Robin Poole 《Matrix biology》2006,25(7):419-429
The objective of this study was to determine whether a fragment(s) of type II collagen can induce cartilage degradation. Fragments generated by cyanogen bromide (CB) cleavage of purified bovine type II collagen were separated by HPLC. These fragments together with selected overlapping synthetic peptides were first analysed for their capacity to induce cleavage of type II collagen by collagenases in chondrocyte and explant cultures of healthy adult bovine articular cartilage. Collagen cleavage was measured by immunoassay and degradation of proteoglycan (mainly aggrecan) was determined by analysis of cleavage products of core protein by Western blotting. Gene expression of matrix metalloproteinases MMP-13 and MMP-1 was measured using Real-time PCR. Induction of denaturation of type II collagen in situ in cartilage matrix with exposure of the CB domain was identified with a polyclonal and monoclonal antibodies that only react with this domain in denatured but not native type II collagen. As well as the mixture of CB fragments and peptide CB12, a single synthetic peptide CB12-II (residues 195-218), but not synthetic peptide CB12-IV (residues 231-254), potently and consistently induced in explant cultures at 10 microM and 25 microM, in a time, cell and dose dependent manner, collagenase-induced cleavage of type II collagen accompanied by upregulation of MMP-13 expression but not MMP-1. In isolated chondrocyte cultures CB12-II induced very limited upregulation of MMP-13 as well as MMP-1 expression. Although this was accompanied by concomitant induction of cleavage of type II collagen by collagenases, this was not associated by aggrecan cleavage. Peptide CB12-IV, which had no effect on collagen cleavage, clearly induced aggrecanase specific cleavage of the core protein of this proteoglycan. Thus these events involving matrix molecule cleavage can importantly occur independently of each other, contrary to popular belief. Denaturation of type II collagen with exposure of the CB12-II domain was also shown to be much increased in osteoarthritic human cartilage compared to non-arthritic cartilage. These observations reveal that peptides of type II collagen, to which there is increased exposure in osteoarthritic cartilage, can when present in sufficient concentration induce cleavage of type II collagen (CB12-II) and aggrecan (CB12-IV) accompanied by increased expression of collagenases. Such increased concentrations of denatured collagen are present in adult and osteoarthritic cartilages and the exposure of chondrocytes to the sequences they encode, either in soluble or more likely insoluble form, may therefore play a role in the excessive resorption of matrix molecules that is seen in arthritis and development. 相似文献
9.
10.
Lavinia Cicortas Gunnarsson Eva Nordberg Karlsson Mats Andersson Olle Holst 《Biocatalysis and Biotransformation》2013,31(1-2):31-37
Structure–function studies are frequently practiced on the very diverse group of natural carbohydrate-binding modules in order to understand the target recognition of these proteins. We have taken a step further in the study of carbohydrate-binding modules and created variants with novel binding properties by molecular engineering of one such molecule of known 3D-structure. A combinatorial library was created from the sequence encoding a thermostable carbohydrate-binding module, CBM4-2 from a Rhodothermus marinus xylanase, and the phage-display technology was successfully used for selection of variants with specificity towards different carbohydrate polymers (birchwood xylan, Avicel?, ivory nut mannan and recently also xyloglucan), as well as towards a glycoprotein (human IgG4). Our work not only generated a number of binders with properties that would suite a range of biotechnological applications, but analysis the selected binders also helped us to identify residues important for their specificities. 相似文献