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971.
972.
FERNANDO STEELE DA CRUZ STUART M. KRASSNER 《The Journal of eukaryotic microbiology》1971,18(4):718-722
SYNOPSIS. Continuous growth of one cell line (UCI variant) of Leishmania tarentolae was achieved in the absence of organic sulfur. These cells were able to use sodium sulfate, and, to a limited extent, sodium sulfite as their sole sulfur source and could utilize methionine sulfoxide in place of L-methionine. A related cell line (RU variant) was unable to grow in organic sulfate-free media nor could these cells utilize methionine sulfoxide. UCI promastigotes incorporated significant amounts of 35S sodium sulfate; killed cells did not take up the label. 35S incorporation was inhibited by sodium molybdate (5 × 10?4 M), sodium arsenite (5 × 10?4 M), 2,4-dinitrophenol (1 × 10?4 M), or KCN (5 × 10?4 M). RU promastigotes did not incorporate significant amounts of 35S sodium sulfate. Thin layer chromatographs of protein hydrolysates from UCI cells incubated in 35S sodium sulfate revealed several radio opaque spots, one of which had chromatographic properties of cystine. UCI variants of L. tarentolae were therefore capable of assimilatory sulfate reduction whereas RU cells lacked this ability. 相似文献
973.
974.
Mary Barton 《BMJ (Clinical research ed.)》1948,1(4555):806-807
975.
Effects of polyoxyethylene detergent (Brij 58) on platelet aggregation,release and clotting activity
Peter G. Barton 《Biochimica et Biophysica Acta (BBA)/General Subjects》1978,539(1):98-113
Low concentrations of a polyoxyethylene detergent, Brij 58, inhibited the secondary phase of platelet aggregation induced by ADP in human citrated platelet-rich but had no effect on primary aggregation. Thrombin-induced aggregation of washed human platelets suspended in Tyrode's buffer was inhibited after incubation of cells with 4 · 10?6 M detergent. Efflux of [14C]serotonin, 45Ca2+ and labile aorta contracting substance (thromboxane A2) and development of prothrombin-converting activity (platelet factor 3) were abolished concomitantly. Aggregation of washed platelets either by sodium arachidonate or by collagen was also inhibited by the same concentration of Brij 58 which inhibited thrombin aggregation. This concentration did not itself produce any release of a cytoplasmic marker, lactate dehydrogenase, from platelets. Higher concentrations of Brij 58, exceeding 4 · 10?5 M, lysed the cells liberating lactate dehydrogenase, serotonin and Ca2+. When albumin was included as a platelet stabilizer in the suspending medium the concentration of detergent required for the inhibitory effects was increased ten-fold. This could be attributed to competitive binding of the detergent to albumin, demonstrated with [14C]acetylated Brij 58. A variety of other polyoxyethylene detergents, at concentrations from 8 · 10?4 to 5 · 10?3 M, also inhibited platelet aggregation induced by thrombin. It is concluded that low concentrations of Brij 58 stabilize the platelets against the action of aggregation agents, while higher concentrations produce membrane destabilization and cell lysis. 相似文献
976.
977.
The maintenance of polygenic variation through a balance between mutation and stabilizing selection 总被引:10,自引:0,他引:10
N H Barton 《Genetical research》1986,47(3):209-216
978.
HIV-1 Vaccine-Induced C1 and V2 Env-Specific Antibodies Synergize for Increased Antiviral Activities
Justin Pollara Mattia Bonsignori M. Anthony Moody Pinghuang Liu S. Munir Alam Kwan-Ki Hwang Thaddeus C. Gurley Daniel M. Kozink Lawrence C. Armand Dawn J. Marshall John F. Whitesides Jaranit Kaewkungwal Sorachai Nitayaphan Punnee Pitisuttithum Supachai Rerks-Ngarm Merlin L. Robb Robert J. O'Connell Jerome H. Kim Nelson L. Michael David C. Montefiori Georgia D. Tomaras Hua-Xin Liao Barton F. Haynes Guido Ferrari 《Journal of virology》2014,88(14):7715-7726
979.
Maxime Veillette Anik Désormeaux Halima Medjahed Nour-Elhouda Gharsallah Mathieu Coutu Joshua Baalwa Yongjun Guan George Lewis Guido Ferrari Beatrice H. Hahn Barton F. Haynes James E. Robinson Daniel E. Kaufmann Mattia Bonsignori Joseph Sodroski Andrés Finzi 《Journal of virology》2014,88(5):2633-2644
980.
Lacy J. Barton Shameika R. Wilmington Melinda J. Martin Hannah M. Skopec Kaylee E. Lovander Belinda S. Pinto Pamela K. Geyer 《Genetics》2014,197(2):653-665
The nuclear lamina is an extensive protein network that contributes to nuclear structure and function. LEM domain (LAP2, emerin, MAN1 domain, LEM-D) proteins are components of the nuclear lamina, identified by a shared ∼45-amino-acid motif that binds Barrier-to-autointegration factor (BAF), a chromatin-interacting protein. Drosophila melanogaster has three nuclear lamina LEM-D proteins, named Otefin (Ote), Bocksbeutel (Bocks), and dMAN1. Although these LEM-D proteins are globally expressed, loss of either Ote or dMAN1 causes tissue-specific defects in adult flies that differ from each other. The reason for such distinct tissue-restricted defects is unknown. Here, we generated null alleles of bocks, finding that loss of Bocks causes no overt adult phenotypes. Next, we defined phenotypes associated with lem-d double mutants. Although the absence of individual LEM-D proteins does not affect viability, loss of any two proteins causes lethality. Mutant phenotypes displayed by lem-d double mutants differ from baf mutants, suggesting that BAF function is retained in animals with a single nuclear lamina LEM-D protein. Interestingly, lem-d double mutants displayed distinct developmental and cellular mutant phenotypes, suggesting that Drosophila LEM-D proteins have developmental functions that are differentially shared with other LEM-D family members. This conclusion is supported by studies showing that ectopically produced LEM-D proteins have distinct capacities to rescue the tissue-specific phenotypes found in single lem-d mutants. Our findings predict that cell-specific mutant phenotypes caused by loss of LEM-D proteins reflect both the constellation of LEM-D proteins within the nuclear lamina and the capacity of functional compensation of the remaining LEM-D proteins. 相似文献