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131.
Identification and characterization of a novel angiostatin-binding protein by the display cloning method 总被引:3,自引:0,他引:3
Angiostatin is a potent anti-angiogenic protein. To examine the angiostatin-interacting proteins, we used the display-cloning method with a T7 phage library presenting human cDNAs. The specific T7 phage clone that bound to the immobilized angiostatin was isolated, and a novel gene encoding the displayed polypeptide on the isolated T7 phage was identified. The displayed angiostatin-binding sequence was expressed in E. coli as a soluble protein and purified to homogeneity. This novel angiostatin-binding region interacted specifically to angiostatin with a dissociation constant of 3.4 x 10(-7) M. A sequence analysis showed that the identified sequence was a part of the large ORF of 1,998 amino acids, whose function has not yet been characterized. A Northern analysis indicated that the gene containing the angiostatin-binding sequence was expressed differentially in the developmental stages or cell types. 相似文献
132.
The activities of antioxidant enzymes in response to oxidative stresses and hormones in paraquat-tolerant Rehmannia glutinosa plants 总被引:1,自引:0,他引:1
Choi DG Yoo NH Yu CY de Los Reyes B Yun SJ 《Journal of biochemistry and molecular biology》2004,37(5):618-624
All members of R. glutinosa show the unique characteristic of intrinsic tolerance to paraquat (PQ). Antioxidant enzymes have been proposed to be the primary mechanism of PQ resistance in several plant species. Therefore, the antioxidant enzyme systems of R. glutinosa were evaluated by comparatively analyzing cellular antioxidant enzyme levels, and their responses of oxidative stresses and hormones. The levels of ascorbate peroxidase (APX), glutathione reductase (GR), non-specific peroxidase (POX), and superoxide dismutase (SOD) were 7.3-, 4.9-, 2.7- and 1.6-fold higher in PQ-tolerant R. glutinosa than in PQ-susceptible soybeans. However, the activity of catalase (CAT) was about 12-fold higher in the soybeans. The activities of antioxidant enzymes reduced after PQ treatment in the two species, with the exception of POX and SOD in R. glutinosa, which increased by about 40 %. Interestingly, the activities of APX, SOD and POX in R. glutinosa, relative to those in soybeans, were further increased by 49, 67 and 93 % after PQ treatment. The considerably higher intrinsic levels, and increases in the relative activities of antioxidant enzymes in R. glutinosa under oxidative stress support the possible role of these enzymes in the PQ tolerance of R. glutinosa. However, the relatively lower levels of SOD versus PQ tolerance, and the mixed responses of antioxidant enzymes to stresses and hormones, suggest a possible alternative mechanism(s) for PQ tolerance in R. glutinosa. 相似文献
133.
Seung-Hak?Baek Yong-Beom?Shin Min-Gon?Kim Hyeon-Su?Ro Eun-Ki?Kim Bong?Hyun?ChungEmail author 《Biotechnology and Bioprocess Engineering》2004,9(2):143-146
A surface plasmon resonance (SPR) imaging system was constructed and used to detect the hexahistidine-ubiquitin-tagged human
parathyroid hormone fragment (His6-Ub-hPTHF(1–34)) expressed inEscherichia coli. The hexahistidine-specific antibody was immobilized on a thin gold film coated with ProLinkerTM B, a novel calixcrown derivative with a bifunctional coupling property that permits efficient immobilization of capture proteins
on solid matrices. The soluble and insoluble fractions of anE. coli cell lysate were spotted onto the antibody-coated gold chip, which was then washed with buffer (pH 7.4) solution and dried.
SPR imaging measurements were carried out to detect the expressed His6-Ub-hPTHF (1–34). There was no discernible protein image in the uninduced cell lysate, indicating that non-specific binding
of contaminant proteins did not occur on the gold chip surface. It is expected that the approach used here to detect affinity-tagged
recombinant proteins using an SPR imaging technique could be used as a powerful tool for the analyses of a number of proteins
in a high-throughput mode. 相似文献
134.
We have examined expression of the lambdacI operon in single cells via a rex Colon, two colons gfp substitution. Although average fluorescence agreed with expectations for expression of lambda-repressor, fluorescence fluctuated greatly from cell-to-cell. Fluctuations in repressor concentration are not predicted by previous models and are tolerated in part by a regulatory response to DNA damage. 相似文献
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139.
Cheng-Ri Yin Dong-Il Seo Seung-Hun Baek Ken Ohlen Sung-Taik Lee 《Biotechnology letters》2001,23(17):1379-1383
Of four chlorinated guaiacols, tetrachloroguaiacol at 62 M inhibited acetate methanogenesis, the strongest decreasing activity by 50%. 4,5,6-Trichloroguaiacol, 4,5-dichloroguaiacol, and 4-chloroguaiacol showed 50% inhibition at 0.13, 0.32, and 1.50 mM, respectively. Degradation test results of volatile fatty acids (acetic, propionic, and butyric acid) by anaerobic digester sludge (stored 5 weeks) indicated that syntrophic butyrate degraders of this sludge were more sensitive to tetrachloroguaiacol than acetoclastic methanogens and syntrophic propionate degraders. 相似文献
140.
Jee JG Ikegami T Hashimoto M Kawabata T Ikeguchi M Watanabe T Shirakawa M 《The Journal of biological chemistry》2002,277(2):1388-1397
Growing evidence suggests that horizontal gene transfer plays an integral role in the evolution of bacterial genomes. One of the debated examples of horizontal gene transfer from animal to prokaryote is the fibronectin type III domain (FnIIID). Certain extracellular proteins of soil bacteria contain an unusual cluster of FnIIIDs, which show sequence similarity to those of animals and are likely to have been acquired horizontally from animals. Here we report the solution structure of the FnIIID of chitinase A1 from Bacillus circulans WL-12. To the best of our knowledge, this is the first tertiary structure to be reported for an FnIIID from a bacterial protein. The structure of the domain shows significant similarity to FnIIIDs from animal proteins. Sequence comparisons with FnIIIDs from other soil bacteria proteins show that the core-forming residues are highly conserved and, thus, are under strong evolutionary pressure. Striking similarities in the tertiary structures of bacterial FnIIIDs and their mammalian counterparts may support the hypothesis that the evolution of the FnIIID in bacterial carbohydrases occurred horizontally. The total lack of surface-exposed aromatic residues also suggests that the role of this FnIIID is different from those of other bacterial beta-sandwich domains, which function as carbohydrate-binding modules. 相似文献