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1.
The Rhodobacter sphaeroides gene encoding subunit IV of the cytochrome b-c1 complex (fbcQ) was cloned and sequenced. The fbcQ cistron is 372 base pairs long and encodes 124 amino acid residues. The molecular mass of subunit IV, deduced from the nucleotide sequence, is 14,384 Da. A hydropathy plot of the predicted amino acid sequence revealed only one transmembrane helix; it is near the C-terminal end. The 3-azido-2-methyl-5-methoxy-6-(3,7-dimethyl[3H]octyl)-1,4-benzoquinone ([3H]azido-Q)-labeled subunit IV was isolated from the [3H]-azido-Q-treated cytochrome b-c1 complex. A ubiquinone-binding peptide was obtained by digesting the labeled subunit IV with V8 protease followed by high performance liquid chromatography separation. Amino acid analysis and partial N-terminal sequencing of this ubiquinone-binding peptide revealed that it corresponded to residues 77-124 of subunit IV. Based on the hydropathy profile and predicted tendency to form alpha-helices and beta-sheets, we propose a structural model for subunit IV. In this model the ubiquinone-binding domain is located near the surface of the membrane. 相似文献
2.
Roles of Four Chitinases (ChiA, ChiB, ChiC, and ChiD) in the Chitin Degradation System of Marine Bacterium Alteromonas sp. Strain O-7 总被引:1,自引:0,他引:1
3.
A new snake-eel,Apterichtus keramanus, is described on the basis of a single 276-mm TL specimen trawled from the coast of Kerama Islands, Okinawa Prefecture, Japan.
The species is unique in the genus in having the posterior nostril opening entirely inside the mouth and a dark band running
from the anteroventral margin of the eye to the upper lip. 相似文献
4.
Polyamine hydrochlorides, NaCl and magnesium acetate stimulated the enzymatic dephosphorylation of phosphorylated H2B histone by two forms (large form, mol. wt. 250 000; small form, mol. wt. 30 000) of a pig heart phosphoprotein phosphatase (phosphoprotein phosphohydrolase, EC 3.1.3.16). These ionic compounds stimulated the large form of the enzyme 5--9-fold but stimulated the small form of theenzyme only 2-fold. With phosphorylated H2B histone as substrate, these effectors caused an increase in both Km and V values of the two forms of the enzyme. On the other hand, when a tryptic phosphodecapeptide derived from phosphorylated H2B histone was used as substrate, these effectors were always inhibitory apparently non-competitively with respect to the substrate. Using phosphorylated H1 histone as substrate, these effectors stimulated the large form of the enzyme 2-fold but inhibited the small form. With phosphorylase a as substrate, the reactions were also inhibited by these effectors irrespective of the enzyme employed. With respect to phosphorylase a, this inhibition was apparently of a competitive type for the large form and a non-competitive type for the small form of the enzyme. 相似文献
5.
Abstract Human immunoglobulin G Fc fragment-binding activity of Mycoplasma salivarium cells was remarkably enhanced by trypsin treatment of the cells. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profile of proteins of the cells treated wtrypsin was the same as that of the cells treated with pronase, although pronase treatment had been shown to reduce the activity in our previous study (FEMS Microbiol. Lett. 123, 305–310, 1994). This contradiction was clarified by the finding that trypsin bound the Fc fragment more strongly than the cells, and a small amount of trypsin remained in the cells treated with trypsin and washed well. On the basis of these results, it was concluded that the enhancement of cell activity by trypsin treatment was ascribed to binding of the Fc fragment to trypsin remaining in the trypsin-treated cells. 相似文献
6.
7.
Usui Akira Kitahara Yuichi Matsushita Yutaka Kitajima Miyoko Sakamoto Reiko Watanabe Tsuyoshi Motohashi Nobutaka 《Sleep and biological rhythms》2008,6(1):53-55
Sleep and Biological Rhythms - The patient was a 21-year-old male who complained of daytime sleepiness. His multiple sleep latency test (MSLT) showed multiple sleep onset REM periods (SOREMPs). The... 相似文献
8.
Qizhi Fang Pamela Y. Mok Anila E. Thomas Daniel J. Haddad Shereen A. Saini Brian T. Clifford Neel K. Kapasi Olivia M. Danforth Minako Usui Weisheng Ye Emmy Luu Rikki Sharma Maya J. Bartel Jeremy A. Pathmanabhan Andrew A. S. Ang Richard E. Sievers Randall J. Lee Matthew L. Springer 《PloS one》2013,8(4)
Pleiotrophin (PTN) is a growth factor with both pro-angiogenic and limited pro-tumorigenic activity. We evaluated the potential for PTN to be used for safe angiogenic gene therapy using the full length gene and a truncated gene variant lacking the domain implicated in tumorigenesis. Mouse myoblasts were transduced to express full length or truncated PTN (PTN or T-PTN), along with a LacZ reporter gene, and injected into mouse limb muscle and myocardium. In cultured myoblasts, PTN was expressed and secreted via the Golgi apparatus, but T-PTN was not properly secreted. Nonetheless, no evidence of uncontrolled growth was observed in cells expressing either form of PTN. PTN gene delivery to myocardium, and non-ischemic skeletal muscle, did not result in a detectable change in vascularity or function. In ischemic hindlimb at 14 days post-implantation, intramuscular injection with PTN-expressing myoblasts led to a significant increase in skin perfusion and muscle arteriole density. We conclude that (1) delivery of the full length PTN gene to muscle can be accomplished without tumorigenesis, (2) the truncated PTN gene may be difficult to use in a gene therapy context due to inefficient secretion, (3) PTN gene delivery leads to functional benefit in the mouse acute ischemic hindlimb model. 相似文献
9.
Methods of cell biology and electrophysiology using dissociated primary cultured neurons allow in vitro study of molecular functions; however, analysis of intact neuronal circuitry is often preferable. To investigate exogenous genes, viral vectors are most commonly injected using a pipette that is inserted from the top of the cortex. Although there are few reports that describe the success rate of injection in detail, it is sometimes difficult to locate the pipette tip accurately within the CA1 pyramidal cell layer because the pyramidal layer is only 0.1 mm thick. In the present study, we have developed a system to inject viral vectors accurately into the mouse hippocampal CA1 pyramidal cell layer using a stereotaxic injection system with simultaneous electrophysiological monitoring of theta oscillation. The pipette tip was positioned reliably based on integrated values of the theta oscillation in the hippocampal CA1 pyramidal cell layer. This approach allows accurate injection of solutions and provides an efficient method of gene transfer using viral vectors into the hippocampus, which can be a useful tool for studies involving the molecular mechanisms of neuronal functions. 相似文献
10.