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101.
Cloning of rat brain succinyl-CoA:3-oxoacid CoA-transferase cDNA. Regulation of the mRNA in different rat tissues and during brain development. 总被引:1,自引:0,他引:1 下载免费PDF全文
M K Ganapathi M Kwon P M Haney C McTiernan A A Javed R A Pepin D Samols M S Patel 《The Biochemical journal》1987,248(3):853-857
3-Oxoacid CoA-transferase, which catalyses the first committed step in the oxidation of ketone bodies, is uniquely regulated in developing rat brain. Changes in 3-oxoacid CoA-transferase activity in rat brain during the postnatal period are due to changes in the relative rate of synthesis of the enzyme. To study the regulation of this enzyme, we identified, with a specific polyclonal rabbit anti-(rat 3-oxoacid CoA-transferase), two positive cDNA clones (approx. 800 bp) in a lambda gtll expression library, constructed from poly(A)+ RNA from brains of 12-day-old rats. One of these clones (lambda CoA3) was subcloned into M13mp18 and subjected to further characterization. Labelled single-stranded probes prepared by primer extension of the M13mp18 recombinant hybridized to a 3.6 kb mRNA. Rat brain mRNA enriched by polysome immunoadsorption for a single protein of size 60 kDa which corresponds to the precursor form of 3-oxoacid CoA-transferase was also found to be similarly enriched for the hybridizable 3.6 kb mRNA complementary to lambda CoA3. Affinity-selected antibody to the lambda CoA3 fusion protein inhibited 3-oxoacid CoA-transferase activity present in rat brain mitochondrial extracts. The 3.6 kb mRNA for 3-oxoacid CoA-transferase was present in relative abundance in rat kidney and heart, to a lesser extent in suckling brain and mammary gland and negligible in the liver. The specific mRNA was also found to be 3-fold more abundant in the brain from 12-day-old rats as compared with 18-day-old foetuses and adult rats, corresponding to the enzyme activity and relative rate of synthesis profile during development. These data suggest that 3-oxoacid CoA-transferase enzyme activity is regulated at a pretranslational level. 相似文献
102.
Characterization of DCL4 missense alleles provides insights into its ability to process distinct classes of dsRNA substrates 下载免费PDF全文
Thomas Montavon Yerim Kwon Aude Zimmermann Philippe Hammann Timothée Vincent Valérie Cognat Marc Bergdoll Fabrice Michel Patrice Dunoyer 《The Plant journal : for cell and molecular biology》2018,95(2):204-218
In the model plant Arabidopsis thaliana, four Dicer‐like proteins (DCL1–4) mediate the production of various classes of small RNAs (sRNAs). Among these four proteins, DCL4 is by far the most versatile RNaseIII‐like enzyme, and previously identified dcl4 missense alleles were shown to uncouple the production of the various classes of DCL4‐dependent sRNAs. Yet little is known about the molecular mechanism behind this uncoupling. Here, by studying the subcellular localization, interactome and binding to the sRNA precursors of three distinct dcl4 missense alleles, we simultaneously highlight the absolute requirement of a specific residue in the helicase domain for the efficient production of all DCL4‐dependent sRNAs, and identify, within the PAZ domain, an important determinant of DCL4 versatility that is mandatory for the efficient processing of intramolecular fold‐back double‐stranded RNA (dsRNA) precursors, but that is dispensable for the production of small interfering RNAs (siRNAs) from RDR‐dependent dsRNA susbtrates. This study not only provides insights into the DCL4 mode of action, but also delineates interesting tools to further study the complexity of RNA silencing pathways in plants, and possibly other organisms. 相似文献
103.
Jung-Hoon Kim Eun-Hye Shin Hak-Yong Lee Bong-Gun Lee Sang-Hoon Park Dae-In Moon Gyo-Chang Goo Dae-Young Kwon Hye-Jeong Yang Ok-Jin Kim Hong-Geun Oh 《Experimental Animals》2013,62(3):247-253
As malfunction/absence of immune cells causes a variety of immunosuppressive disorders
and chemical synthetic drugs for curing these diseases have many adverse effects, vigorous
studies are being conducted. The Acanthopanax family has been used as
traditional medicines for gastric ulcer, diabetes, etc. and culinary materials in
East-South Asia. In this study, the immunostimulating properties of A.
sessiliflorus were evaluated. A. sessiliflorus increased not
only the splenocyte number but also immune-related cytokines such as TNF-α. However, it
could not upregulate the expressions of IFN-γ and IL-2. A. sessiliflorus
increased the swimming time, and comparison of organ weights relative to body weights for
immune-related organs such as the spleen and thymus after a forced swim test showed that
it could recover the spleen and thymus weights. It also increased the expression of TNF-α
and slightly increased the concentration of IFN-γ but not IL-2. From the results, we
concluded that as A. sessiliflorus has not only a host defense effect but
also a stress-ameliorating property, further study it will be a promising material of
immunostimulating material. 相似文献
104.
Lee Changsu Song Hye Seon Lee Se Hee Kim Joon Yong Rhee Jin-Kyu Roh Seong Woon 《Archives of microbiology》2021,203(1):261-268
Archives of Microbiology - Extremely halophilic archaea (haloarchaea) belonging to the phylum Euryarchaeota have been found in high-salinity environments. In this study, Halarchaeum sp. CBA1220,... 相似文献
105.
Pak Valeriy V. Kwon Dae Yong Khojimatov Olim K. Pak Aleksandr V. Sagdullaev Shomansur Sh. 《International journal of peptide research and therapeutics》2021,27(3):1923-1931
International Journal of Peptide Research and Therapeutics - This study presents a simple approach in design of tripeptides as a competitive inhibitor for 3-hydroxy-3-methylglutaryl CoA reductase... 相似文献
106.
107.
Loop-gating is one of two voltage-dependent mechanisms that regulate the open probability of connexin channels. The loop-gate permeability barrier is formed by a segment of the first extracellular loop (E1) (the parahelix) and appears to be accompanied by straightening of the bend angle between E1 and the first transmembrane domain (TM1). Here, all-atom molecular dynamics simulations are used to identify and characterize interacting van der Waals and electrostatic networks that stabilize the parahelices and TM1/E1 bend angles of the open Cx26 hemichannel. Dynamic fluctuations in an electrostatic network in each subunit are directly linked to the stability of parahelix structure and TM1/E1 bend angle in adjacent subunits. The electrostatic network includes charged residues that are pore-lining and thus positioned to be voltage sensors. We propose that the transition to the closed state is initiated by voltage-driven disruption of the networks that stabilize the open-state parahelix configuration, allowing the parahelix to protrude into the channel pore to form the loop-gate barrier. Straightening of the TM1/E1 bend appears to be a consequence of the reorganization of the interacting networks that accompany the conformational change of the parahelix. The electrostatic network extends across subunit boundaries, suggesting a concerted gating mechanism. 相似文献
108.
Jung W Lee SG Kang SW Lee YS Lee JH Kang SH Jin ES Kim HJ 《Journal of microbiology and biotechnology》2012,22(7):902-906
Expressed sequence tags (ESTs) from the Antarctic green algae Pyramimonas gelidicola were analyzed to obtain molecular information on cold acclimation of psychrophilic microorganisms. A total of 2,112 EST clones were sequenced, generating 222 contigs and 219 singletons, and 200 contigs and 391 singletons from control (4 degrees C) and cold-shock conditions (-2 degrees C), respectively. The complete EST sequences were deposited to the DDBJ EST database (http:// www.ddbj.nig.ac.jp/index-e.html) and the nucleotide sequences reported in this study are available in the DDBJ/EMBL/ GenBank. These EST databases of Antarctic green algae can be used in a wide range of studies on psychrophilic genes expressed by polar microorganisms. 相似文献
109.
110.
Feeding and grazing impact by small marine heterotrophic dinoflagellates on heterotrophic bacteria 总被引:1,自引:0,他引:1
Jeong HJ Seong KA Yoo YD Kim TH Kang NS Kim S Park JY Kim JS Kim GH Song JY 《The Journal of eukaryotic microbiology》2008,55(4):271-288
ABSTRACT. We investigated the feeding of the small heterotrophic dinoflagellates (HTDs) Oxyrrhis marina , Gyrodinium cf. guttula , Gyrodinium sp., Pfiesteria piscicida , and Protoperidinium bipes on marine heterotrophic bacteria. To investigate whether they are able to feed on bacteria, we observed the protoplasm of target heterotrophic dinoflagellate cells under an epifluorescence microscope and transmission electron microscope. In addition, we measured ingestion rates of the dominant heterotrophic dinoflagellate, Gyrodinium spp., on natural populations of marine bacteria (mostly heterotrophic bacteria) in Masan Bay, Korea in 2006–2007. Furthermore, we measured the ingestion rates of O. marina , G . cf. guttula , and P. piscicida on bacteria as a function of bacterial concentration under laboratory conditions. All HTDs tested were able to feed on a single bacterium. Oxyrrhis marina and Gyrodinium spp. intercepted and then ingested a single bacterial cell in feeding currents that were generated by the flagella of the predators. During the field experiments, the ingestion rates and grazing coefficients of Gyrodinium spp. on natural populations of bacteria were 14–61 bacteria/dinoflagellate/h and 0.003–0.972 day−1 , respectively. With increasing prey concentration, the ingestion rates of O. marina , G . cf. guttula , and P. piscicida on bacteria increased rapidly at prey concentrations of ca 0.7–2.2 × 106 cells/ml, but increased only slowly or became saturated at higher prey concentrations. The maximum ingestion rate of O. marina on bacteria was much higher than those of G . cf. guttula and P. piscicida . Bacteria alone supported the growth of O. marina . The results of the present study suggest that some HTDs may sometimes have a considerable grazing impact on populations of marine bacteria, and that bacteria may be important prey. 相似文献