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排序方式: 共有1015条查询结果,搜索用时 437 毫秒
991.
992.
993.
A chicken embryo protein related to the mammalian DEAD box protein p68 is tightly associated with the highly purified protein-RNA complex of 5-MeC-DNA glycosylase. 总被引:6,自引:1,他引:5 下载免费PDF全文
J P Jost S Schwarz D Hess H Angliker F V Fuller-Pace H Stahl S Thiry M Siegmann 《Nucleic acids research》1999,27(16):3245-3252
994.
John T. Kemper 《Bulletin of mathematical biology》1978,40(6):707-718
A deterministic model for a multi-agent disease epidemic with asymptomatic attacks is proposed and investigated. The limitations
inherent in the assumptions of the model are discussed in connection with specific agents of disease. The mathematical treatment
of the model is separated into analyses of the equilibrium situation and the transient behavior of the disease outbreak. Explicit
formulas are derived for the number of susceptibles in the population as well as for the numbers of each type of infective—those
with and without symptoms. These theoretical results are followed by a discussion of the practical considerations which must
be taken into account to obtain useful information from the model.
This work was supported in part by National Library of Medicine Training Grant Number 5 T01 LM00160 and in part by National
Institutes of Health National Research Service Award Number 1 F32 GMO 5839 from the Institute of General Medical Sciences. 相似文献
995.
996.
Antonio G. González Raimundo Freire Rosendo Hernández Jost A. Salazar Ernesto Suárez 《Phytochemistry》1973,12(11):2733-2735
From stems and leaves of Semele androgyna L. the new steroid sapogenin 25S-dihydrodracogenin (Ia) has been isolated and its structure confirmed by conversion into the acetates of 25R-dihydrosansevierigenin (Id) and ruscogenin (If) and by partial hydrogenation of dracogenin. 相似文献
997.
998.
Summary Heterocysts of Anabaena cylindrica, isolated rapidly in the cold, were found—in contrast to earlier reports—to contain all of the same lipids and lipophilic pigments, and in about the same proportions, as vegetative cells. In broken filaments and in heterocysts damaged during isolation, the membrane lipids and certain pigments (myxoxanthophyll and an unidentified red pigment) break down rapidly. The glycolipids specific to heterocyst-forming blue-green algae are localized in the laminated layer of the heterocyst envelope. A possible role of the laminated layer is discussed. 相似文献
999.
Xiaojing Yang Anna Payne-Tobin Jost Orion D. Weiner Chao Tang 《Molecular biology of the cell》2013,24(15):2419-2430
Protein localization plays a central role in cell biology. Although powerful tools exist to assay the spatial and temporal dynamics of proteins in living cells, our ability to control these dynamics has been much more limited. We previously used the phytochrome B– phytochrome-interacting factor light-gated dimerization system to recruit proteins to the plasma membrane, enabling us to control the activation of intracellular signals in mammalian cells. Here we extend this approach to achieve rapid, reversible, and titratable control of protein localization for eight different organelles/positions in budding yeast. By tagging genes at the endogenous locus, we can recruit proteins to or away from their normal sites of action. This system provides a general strategy for dynamically activating or inactivating proteins of interest by controlling their localization and therefore their availability to binding partners and substrates, as we demonstrate for galactose signaling. More importantly, the temporal and spatial precision of the system make it possible to identify when and where a given protein''s activity is necessary for function, as we demonstrate for the mitotic cyclin Clb2 in nuclear fission and spindle stabilization. Our light-inducible organelle-targeting system represents a powerful approach for achieving a better understanding of complex biological systems. 相似文献
1000.
Various parts of the skeleton and/or the longest baleen plate of 46 specimens of Caperea marginata from Australia and New Zealand were measured and related to body length. Of the 32 skull, postcranial and baleen-plate measurements available, eight were analysed and seven found to be good predictors of body length, by using a curvilinear model describing their relationship with body length. Greatest skull width, supraoccipital length and mandible length had the smallest prediction limits (± 0.28-0.33 m in small animals, ±0.44-0.58 m in large animals) when compared with postcranial measurements (scapula length, vertebra 7 centrum width). Baleen-plate length was also a useful predictor of body length (±0.32-0.77 m). There was a substantial increase in the arch of the skull as body length increased. Bulla length was not a good predictor of body length, because measurements were highly variable and because the bulla grew little during postnatal life. Physical maturity occurred at body lengths of at least 5.9 m, also the shortest length at which both epiphyses of the humerus and proximal epiphyses of the radius and ulna were fused. Weaning appears to occur at about 3-3.5 m. The following approximate relative age/length classes were erected: dependent calves, <3.6 m; subadults, 3.6-5.5 m; adults, >5.5 m. Females were significantly longer than males in the sample of 22 animals greater than 5.9 m, length of the smallest recorded physically mature animal. 相似文献