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11.
Feeding studies on rice genetically modified with soybean glycinin were performed on rats for four weeks. The rats were divided into three groups, each being fed on (I) only a commercial diet, (II) this diet plus control rice and (III) this diet plus rice genetically modified with glycinin. The rats were fed with 10 g/kg-weight of rice every day by oral administration. During the test period, the rats in every group grew well without marked differences in appearance, food intake, body weight, or cumulative body weight gain. There were also no significant differences in the blood count, blood composition or internal organ weights among the rats. Necropsy at the end of the experiment indicated neither pathological symptoms nor histopathological abnormalities in the liver and kidney. Judging from these results, the rice genetically modified with glycinin is considered to have been essentially the same in nutritional and biochemical characteristics as the control rice.  相似文献   
12.
The proteomic response to bacterial infection in a teleost fish (Paralichthys olivaceus) infected with Streptococcus parauberis was analyzed using label-free protein quantitation coupled with LC-MS(E) tandem mass spectrometry. A total of 82 proteins from whole kidney, a major lymphoid organ in this fish, were found to be differentially expressed between healthy and diseased fish analyzed 6, 24, 72 and 120 h post-infection. Among the differentially expressed proteins, those involved in mediating immune responses (e.g., heat shock proteins, cathepsins, goose-type lysozyme and complement components) were most significantly up-regulated by infection. In addition, cell division cycle 48 (CDC48) and calreticulin, which are associated with cellular recovery and glycoprotein synthesis, were up-regulated in the universal protein group, whereas the other proteins in that group were down-regulated. There was continuous activation of expression of immune-associated proteins during infection, but there was also loss of expression of proteins not involved in immune function. We expect that our findings regarding immune response at the protein level would offer new insight into the systemic response to bacterial infection of a major immune organ in teleost fish.  相似文献   
13.
生物多样性的几个问题(续)   总被引:3,自引:1,他引:3  
从生物多样性的现状、存在的问题及应采取的措施等三个方面比较全面地叙述了我国生物多样性的情况。“生物安全”是《生物多样性公约《签订后每次缔约国会议都要讨论的中心议题之一。为之本文也用一定的篇幅作了较详细的介绍。  相似文献   
14.
全球转基因大豆专利信息分析与技术展望   总被引:2,自引:0,他引:2  
转基因大豆作为目前转基因作物推广种植面积最广的作物,在保障人类油料与饲料供给上发挥着重要作用。基于智慧芽数据库(PatSnap)对欧盟、美国及中国等国家地区1985~2016年收录的全球转基因大豆技术领域专利文献进行统计分析,得出全球转基因大豆专利信息的总体发展趋势、研发热点及技术分布与格局,并对比分析了我国转基因大豆研发的竞争力,对未来转基因大豆的产业发展提出了展望。  相似文献   
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16.
Syndecan-4 core protein is composed of extracellular, transmembrane, and cytoplasmic domains. The cytoplasmic domain functions in transmitting signals into the cell through the protein kinase C alpha (PKCα) pathway. The glycosaminoglycan (GAG) and N-linked glycosylated (N-glycosylated) chains attached to the extracellular domain influence cell proliferation. The current study investigated the function of syndecan-4 cytoplasmic domain in combination with GAG and N-glycosylated chains in turkey muscle cell proliferation, differentiation, fibroblast growth factor 2 (FGF2) responsiveness, and PKCα membrane localization. Syndecan-4 or syndecan-4 without the cytoplasmic domain and with or without the GAG and N-glycosylated chains were transfected or co-transfected with a small interfering RNA targeting syndecan-4 cytoplasmic domain into turkey muscle satellite cells. The overexpression of syndecan-4 mutants increased cell proliferation but did not change differentiation. Syndecan-4 mutants had increased cellular responsiveness to FGF2 during proliferation. Syndecan-4 increased PKCα cell membrane localization, whereas the syndecan-4 mutants decreased PKCα cell membrane localization compared to syndecan-4. However, compared to the cells without transfection, syndecan-4 mutants increased cell membrane localization of PKCα. These data indicated that the syndecan‐4 cytoplasmic domain and the GAG and N-glycosylated chains are critical in syndecan-4 regulating satellite cell proliferation, responsiveness to FGF2, and PKCα cell membrane localization.  相似文献   
17.
Aim  The utility of GIS-based and phylogenetic biogeographical analysis in palaeobiogeography is reviewed with reference to its ability to elucidate patterns of interest for modern conservation biology, specifically the long-term effects of invasive species.
Location  Emphasis is on biogeographical patterns in the Appalachian basin and mid-continent of North America during the Devonian. Global palaeobiogeographical patterns of the Cambrian are also considered.
Methods  Palaeobiogeographical patterns are assessed within a GIS framework, including both direct range reconstruction and niche modelling methods, and within phylogenetic biogeographical analysis. Biogeographical patterns are considered within multiple clades of fossil invertebrates, including trilobites, crustaceans, brachiopods, and bivalves.
Results  GIS-based analysis (including niche modelling methods) of Devonian invertebrates demonstrates a tightly correlated relationship between sea-level rises and range expansion, dispersal events, and species invasions. The predominance of range expansion and species invasions during the Late Devonian reduced opportunities for vicariant speciation during this interval. Comparison of phylogenetic biogeographical patterns between Cambrian and Devonian trilobites allows discernment of the relative roles of tectonics and eustacy in driving biogeographical patterns.
Main conclusions  GIS analysis and phylogenetic biogeography are powerful tools for analysing the coevolution of the Earth and its biota. Analyses can identify episodes of vicariance and geo-dispersal and produce testable hypotheses for further analysis within the fossil record.  相似文献   
18.
Retroviral proteases are translated as a part of Gag-related polyproteins, and are released and activated during particle release. Mason-Pfizer monkey virus (M-PMV) Gag polyproteins assemble into immature capsids within the cytoplasm of the host cells; however, their processing occurs only after transport to the plasma membrane and subsequent release. Thus, the activity of M-PMV protease is expected to be highly regulated during the replication cycle. It has been proposed that reversible oxidation of protease cysteine residues might be responsible for such regulation. We show that cysteine residues in M-PMV protease can form an intramolecular S-S bridge. The disulfide bridge shifts the monomer/dimer equilibrium in favor of the dimer, and increases the proteolytic activity significantly. To investigate the role of this disulfide bridge in virus maturation and replication, we engineered an M-PMV clone in which both protease cysteine residues were replaced by alanine (M-PMV(PRC7A/C106A)). Surprisingly, the cysteine residues were dispensable for Gag polyprotein processing within the virus, indicating that even low levels of protease activity are sufficient for polyprotein processing during maturation. However, the long-term infectivity of M-PMV(PRC7A/C106A) was noticeably compromised. These results show clearly that the proposed redox mechanism does not rely solely on the formation of the stabilizing S-S bridge in the protease. Thus, in addition to the protease disulfide bridge, reversible oxidation of cysteine and/or methionine residues in other domains of the Gag polyprotein or in related cellular proteins must be involved in the regulation of maturation.  相似文献   
19.
In neuroblastoma N1E 115 cells, carbachol, histamine and PGE1 elevated cyclic GMP content and, induced the efflux of preloaded 45Ca2+, the release of membrane-bound Ca2+ measured by fluorescent CTC, and the increase in [Ca2+]i as measured by Quin 2 fluorescence. The time course of the responses, the absolute requirement of extracellular Ca2+, the inhibition by receptor blockers, and the concentration dependency on histamine were all similar between these responses. The observation indicates that the mobilization of Ca2+, especially the increase of [Ca2+]i, may be intimately linked to the synthesis of cyclic GMP in the cells.  相似文献   
20.
Nitric oxide (NO) inhibits mitochondrial respiration by decreasing the apparent affinity of cytochrome c oxidase (CcO) for oxygen. Using iNOS-transfected HEK 293 cells to achieve regulated intracellular NO production, we determined NO and O2 concentrations and mitochondrial O2 consumption by high-resolution respirometry over a range of O2 concentrations down to nanomolar. Inhibition of respiration by NO was reversible, and complete NO removal recovered cell respiration above its routine reference values. Respiration was observed even at high NO concentrations, and the dependence of IC50 on [O2] exhibits a characteristic but puzzling parabolic shape; both these features imply that CcO is protected from complete inactivation by NO and are likely to be physiologically relevant. We present a kinetic model of CcO inhibition by NO that efficiently predicts experimentally determined respiration at physiological O2 and NO concentrations and under hypoxia, and accurately predicts the respiratory responses under hyperoxia. The model invokes competitive and uncompetitive inhibition by binding of NO to the reduced and oxidized forms of CcO, respectively, and suggests that dissociation of NO from reduced CcO may involve its O2-dependent oxidation. It also explains the non-linear dependence of IC50 on O2 concentration, and the hyperbolic increase of c50 as a function of NO concentration.  相似文献   
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