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991.
We have developed a practical and economical device that efficiently concentrates ciliated cells, such asTetrahymena pyriformis, by using only low-speed, non-damaging centrifugation. This is carried out with a simple device consisting of a microcentrifuge tube connected to the barrel of a 60-ml plastic syringe. This device allows the concentration of essentially all the cells into a small volume without damaging cell structures or reducing their viability. 相似文献
992.
Pedro Lozano Didier Combes José L. Iborra Arturo Manjón 《Biotechnology letters》1993,15(12):1223-1228
Summary The synthesis of L-tyrosine glyceryl ester, from glycerol and L-tyrosine methyl ester, was carried out by a transesterification reaction catalyzed by -chymotrypsin. Values of 60 % (v/v) for glycerol and 200 mM for L-tyrosine methyl ester were optimal for the transesterification reaction. Additionally to glycerol, several other water miscible cosolvents (acetonitrile, N,N'-dimetyl formamide and tetrahydrofurane) were tested in the reaction media, but their presence did not give an enhancement on the transesterification activity with respect to the glycerol/water medium. However, increasing the hydrophobicity of the cosolvent resulted in a reduction of the enzyme activity, the water:glycerol mixture being the best reaction media. 相似文献
993.
Hugo Schweke Qifang Xu Gerardo Tauriello Lorenzo Pantolini Torsten Schwede Frédéric Cazals Alix Lhéritier Juan Fernandez-Recio Luis Angel Rodríguez-Lumbreras Ora Schueler-Furman Julia K. Varga Brian Jiménez-García Manon F. Réau Alexandre M. J. J. Bonvin Castrense Savojardo Pier-Luigi Martelli Rita Casadio Jérôme Tubiana Haim J. Wolfson Romina Oliva Didier Barradas-Bautista Tiziana Ricciardelli Luigi Cavallo Česlovas Venclovas Kliment Olechnovič Raphael Guerois Jessica Andreani Juliette Martin Xiao Wang Genki Terashi Daipayan Sarkar Charles Christoffer Tunde Aderinwale Jacob Verburgt Daisuke Kihara Anthony Marchand Bruno E. Correia Rui Duan Liming Qiu Xianjin Xu Shuang Zhang Xiaoqin Zou Sucharita Dey Roland L. Dunbrack Emmanuel D. Levy Shoshana J. Wodak 《Proteomics》2023,23(17):2200323
Reliably scoring and ranking candidate models of protein complexes and assigning their oligomeric state from the structure of the crystal lattice represent outstanding challenges. A community-wide effort was launched to tackle these challenges. The latest resources on protein complexes and interfaces were exploited to derive a benchmark dataset consisting of 1677 homodimer protein crystal structures, including a balanced mix of physiological and non-physiological complexes. The non-physiological complexes in the benchmark were selected to bury a similar or larger interface area than their physiological counterparts, making it more difficult for scoring functions to differentiate between them. Next, 252 functions for scoring protein-protein interfaces previously developed by 13 groups were collected and evaluated for their ability to discriminate between physiological and non-physiological complexes. A simple consensus score generated using the best performing score of each of the 13 groups, and a cross-validated Random Forest (RF) classifier were created. Both approaches showed excellent performance, with an area under the Receiver Operating Characteristic (ROC) curve of 0.93 and 0.94, respectively, outperforming individual scores developed by different groups. Additionally, AlphaFold2 engines recalled the physiological dimers with significantly higher accuracy than the non-physiological set, lending support to the reliability of our benchmark dataset annotations. Optimizing the combined power of interface scoring functions and evaluating it on challenging benchmark datasets appears to be a promising strategy. 相似文献
994.
Marilyne Sasportes Didier Fradelizi Antonio Nunez-Roldan Emmanuelle Wollman Zoïs Giannopoulos Jean Dausset 《Immunogenetics》1978,6(1):29-42
HLA-D typing, primed lymphocyte test (PLT), and DR (Ia-like) serology were compared in a population and family study. A significant positive correlation was observed between theHLA-D region products detected by these three techniques. The strongest correlation observed was between PLT and DR serology, indicating a very close functional similarity between PL and DRw antigens. The DRw antigens and/or PL products appear to be mainly responsible for secondary proliferation. Data are presented which suggest that DRw and/or PL products could be distinct from the Dw products, involved in primary MLR. Nevertheless, a DRw disparity associated with a Dw incompatability is able to increase the intensity of a primary MLR, suggesting that DRw antigens also influence a primary proliferative response. 相似文献
995.
Pure rabbit fibrinogen was prepared by a method involving two ammonium sulfate precipitations, one 2 M phosphate buffer precipitation, one DEAE cellulose chromatography and lastly one Sepharose 6 B chromatography. The aminoacid composition was determined and an immunonephelemetric assay was proposed. This assay allowed an accurate determination of fibrinogen concentration in a rabbit with inflammatory reaction. 相似文献
996.
Renée Favre Alina Wiater Simonetta Puppo Maurizio Iaccarino Randolph Noelle Martin Freundlich 《Molecular & general genetics : MGG》1976,143(3):243-252
Summary A strain carrying the ilv0603 mutation has been isolated in E. coli K-12 and its characteristics were found to be very similar to those previously reported by Ramakrishnan and Adelberg (1965a) for other ilv0 mutants.The strain carrying the ilv0603 mutation is resistant to valine inhibition (Valr) and we show that this resistance depends on the expression of a newly recognized gene, ilvG, which is located at min 75, between ilvE and ilvD on the E. coli K-12 map. The ilvG gene causes the expression of a Valr acetolactate synthase, which is detectable only when the ilv0603 mutation is also present in cis on the same chromosome. Under these conditions the Valr acetolactate synthase activity is eluted, on a hydroxylapatite column, at an ionic strength slightly lower than that required for elution of the remaining acetolactate synthase activity (sensitive to valine inhibition). The Valr peak is missing in a strain carrying an ilvG (amber) mutation. 相似文献
997.
998.
Molecular cloning and expression of a cDNA encoding 1-aminocyclopropane-1-carboxylate (ACC) oxidase from apricot fruit (Prunus armeniaca) 总被引:1,自引:0,他引:1
999.
E Cohen-Jonathan C Toulas I Ader S Monteil C Allal J Bonnet A D Hamilton S M Sebti N Daly-Schveitzer G Favre 《Radiation research》1999,152(4):404-411
In this paper, we describe the effect of the inhibitor of farnesyltransferase (FTI-277) on radioresistance induced by the 24-kDa isoform of FGF2 in human cells expressing wild-type RAS. Treatment with FTI-277 (20 microM) for 48 h prior to irradiation led to a significant decrease in survival of radioresistant cells expressing the 24-kDa isoform (HeLa 3A) but had no effect on the survival of control cells (HeLa PINA). The radiosensitizing effect of FTI-277 is accompanied by a stimulation of postmitotic cell death in HeLa 3A cells and by a reduction in G(2)/M-phase arrest in both cell types. These results clearly demonstrate that at least one farnesylated protein is involved in the regulation of the radioresistance induced by the 24-kDa isoform of FGF2. Furthermore, the radiation-induced G(2)/M-phase arrest is also under the control of farnesylated protein. This work also demonstrates that FTase inhibitors may be effective radiosensitizers of certain human tumors with wild-type RAS. 相似文献
1000.
D M Kolpashchikov K Weisshart H P Nasheuer S N Khodyreva E Fanning A Favre O I Lavrik 《FEBS letters》1999,450(1-2):131-134
Human replication protein A is a heterotrimeric protein involved in various processes of DNA metabolism. To understand the contribution of replication protein A individual subunits to DNA binding, we have expressed them separately as soluble maltose binding protein fusion proteins. Using a DNA construct that had a photoreactive group incorporated at the 3'-end of the primer strand, we show that the p70 subunit on its own is efficiently cross-linked to the primer at physiological concentrations. In contrast, crosslinking of the p32 subunit required two orders of magnitude higher protein concentrations. In no case was the p14 subunit labelled above background. p70 seems to be the predominant subunit to bind single-stranded DNA and this interaction positions the p32 subunit to the 3'-end of the primer. 相似文献