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101.
Human immunodeficiency virus-restricted replication in astrocytes and the ability of gamma interferon to modulate this restriction are regulated by a downstream effector of the Wnt signaling pathway 总被引:1,自引:1,他引:0 下载免费PDF全文
Carroll-Anzinger D Kumar A Adarichev V Kashanchi F Al-Harthi L 《Journal of virology》2007,81(11):5864-5871
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The hypothesis presented here for proton transfer away from the water oxidation complex of Photosystem II (PSII) is supported by biochemical experiments on the isolated PsbO protein in solution, theoretical analyses of better understood proton transfer systems like bacteriorhodopsin and cytochrome oxidase, and the recently published 3D structure of PS II (Pdb entry 1S5L). We propose that a cluster of conserved glutamic and aspartic acid residues in the PsbO protein acts as a buffering network providing efficient acceptors of protons derived from substrate water molecules. The charge delocalization of the cluster ensures readiness to promptly accept the protons liberated from substrate water. Therefore protons generated at the catalytic centre of PSII need not be released into the thylakoid lumen as generally thought. The cluster is the beginning of a localized, fast proton transfer conduit on the lumenal side of the thylakoid membrane. Proton-dependent conformational changes of PsbO may play a role in the regulation of both supply of substrate water to the water oxidizing complex and the resultant proton transfer. 相似文献
104.
Hillier W McConnell I Badger MR Boussac A Klimov VV Dismukes GC Wydrzynski T 《Biochemistry》2006,45(7):2094-2102
On the basis of equilibrium isotopic distribution experiments using (18)O-labeled water, it is generally accepted that water is the sole substrate for O(2) production by photosystem II (PSII). Nevertheless, recent studies indicating a direct interaction between bicarbonate and the donor side of PSII have been used to hypothesize that bicarbonate may have been a physiologically important substrate for O(2) production during the evolution of PSII [Dismukes, G. C., Klimov, V. V., Baranov, S. V., Kozlov, Y. N., DasGupta, J., and Tyryshikin, A. (2001) Proc. Natl. Acad. Sci. U.S.A. 98, 2170-2175]. To test out this hypothesis and to determine whether contemporary oxygenic organisms have the capacity to oxidize bicarbonate, we employed special rapid-mixing isotopic experiments using (18)O/(13)C-labeled bicarbonate to quantify the inherent carbonic anhydrase activity in PSII samples and the potential flux of oxygen from bicarbonate into the photosynthetically produced O(2). The measurements were made on PSII samples prepared from spinach, Thermosynechococcus elongatus, and Arthrospira maxima. For the latter organism, a strain was used that grows naturally in an alkaline, high (bi)carbonate soda lake in Africa. The results reveal that bicarbonate is not the substrate for O(2) production in these contemporary oxygenic photoautotrophs when assayed under single turnover conditions. 相似文献
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Margarita V. Rodionova Sergei K. Zharmukhamedov Mehmet Sayım Karacan Kubra Begum Venedik Alexandr V. Shitov Turgay Tunç Serhat Mamaş Vladimir D. Kreslavski Nurcan Karacan Vyacheslav V. Klimov Suleyman I. Allakhverdiev 《Photosynthesis research》2017,133(1-3):139-153
Increasing inefficiency of production of important agricultural plants raises one of the biggest problems in the modern world. Herbicide application is still the best method of weed management. Traditional herbicides blocking only one of the plant metabolic pathways is ineffective due to the rapid growth of herbicide-resistant weeds. The synthesis of novel compounds effectively suppressing several metabolic processes, and therefore achieving the synergism effect would serve as the alternative approach to weed problem. For this reason, recently, we synthesized a series of nine novel Cu(II) complexes and four ligands, characterized them with different analyses techniques, and carried out their primary evaluation as inhibitors of photosynthetic electron transfer in spinach thylakoids (design, synthesis, and evaluation of a series of Cu(II) based metal–organic complexes as possible inhibitors of photosynthesis, J Photochem Photobiol B, submitted). Here, we evaluated in vitro inhibitory potency of these agents against: photochemistry and carbonic anhydrase activity of photosystem II (PSII); α-carbonic anhydrase from bovine erythrocytes; as well as glutathione reductase from chloroplast and baker’s yeast. Our results show that all Cu(II) complexes excellently inhibit glutathione reductase and PSII carbonic anhydrase activity. Some of them also decently inhibit PSII photosynthetic activity. 相似文献
107.
Carolyne Bardeleben Vyacheslav Palchevskiy Ryan Calsbeek Robert K. Wayne 《Molecular ecology resources》2004,4(2):176-178
Eleven polymorphic microsatellite markers have been developed for the brown anole, Anolis sagrei. The number of alleles range from five to 14 per locus with the observed heterozygosity ranging from 0.46 to 0.92. These markers will be useful for analysis of questions concerning population genetic structure and reproductive behaviour. 相似文献
108.
Theodore W. Pietsch Victor V. Bogatov Kunio Amaoka Yuri N. Zhuravlev Vyacheslav Y. Barkalov Sarah Gage Hideki Takahashi Arkady S. Lelej Sergey Y. Storozhenko Norobu Minakawa Daniel J. Bennett Trevor R. Anderson Masahiro Ôhara Larisa A. Prozorova Yasuhiro Kuwahara Sergey K. Kholin Mamoru Yabe Duane E. Stevenson Erin L. MacDonald 《Journal of Biogeography》2003,30(9):1297-1310
109.
Tomasz Przygodzki Marcin Talar Agnieszka Blazejczyk Vyacheslav Kalchenko Cezary Watala 《PloS one》2016,11(1)
IntroductionThe paper describes an alternative method for quantification of in vivo ADP-induced thromboembolism. The aim of the studies was to develop a method of quantification which would not require either extravasation or labelling of platelets. Our proposed approach is based on the monitoring of changes of blood flow with the use of laser Doppler flowmetry.ResultsThe injection of ADP resulted in a dose-dependent reduction of the blood flow in the mesentery. These responses were fully attributable to blood platelet aggregation, as shown by the lack of the effect in platelet-depleted mice, and significantly reduced responses in mice pretreated with cangrelor and eptifibatide. No platelet aggregate formation in mesenteric vessels was revealed by intravital microscopy, while ex vivo imaging showed accumulation of fluorescent labelled platelets in the lung.ConclusionsInjection of ADP to the venous system results in the formation of platelet aggregates predominantly in the lung. This results in reversible blood flow cessation in peripheral blood vessels. The measurement of this blood flow cessation in the mesentery allows indirect measurement of ADP-induced pulmonary thromboembolism. We suggest that this approach can be useful for in vivo screening for antiplatelet drug candidates. 相似文献
110.
Lukyanov P Furtak V Ochieng J 《Biochemical and biophysical research communications》2005,338(2):1031-1036
The precise mechanism by which galectin-3 and other cytosolic proteins that lack signal peptides are secreted is yet to be elucidated. In the present analyses, we determined that galectin-3, a beta-galactoside binding protein, can interact directly with membrane lipids in solid phase binding assays. More interestingly, we determined by spectrophotometric methods that it can spontaneously penetrate the lipid bilayer of liposomes in either direction. These findings suggest that galectin-3 on its own has the capacity to traverse the lipid bilayer. Whereas the situation is rather simplified in liposomes, the interaction of galectin-3 with the plasma membrane may involve cholesterol-rich membrane domains where galectin-3 can be concentrated and form multimers or interact covalently with other proteins. 相似文献