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961.
962.
Phenotypic analysis of cell surface markers and gene expression of human mesenchymal stem cells and chondrocytes during monolayer expansion 总被引:1,自引:0,他引:1
Cournil-Henrionnet C Huselstein C Wang Y Galois L Mainard D Decot V Netter P Stoltz JF Muller S Gillet P Watrin-Pinzano A 《Biorheology》2008,45(3-4):513-526
Both chondrocytes and mensenchymal stem cells (MSCs) are the most used cell sources for cartilage tissue engineering. However, monolayer expansion to obtain sufficient cells leads to a rapid chondrocyte dedifferentiation and a subsequent ancillary reduced ability of MSCs to differentiate into chondrocytes, thus limiting their application in cartilage repair. The aim of this study was to investigate the influence of the monolayer expansion on the immunophenotype and the gene expression profile of both cell types, and to find the appropriate compromise between monolayer expansion and the remaining chondrogenic characteristics. To this end, human chondrocytes, isolated enzymatically from femoral head slice, and human MSCs, derived from bone marrow, were maintained in monolayer culture up to passage 5. The respective expressions of cell surface markers (CD34, CD45, CD73, CD90, CD105, CD166) and several chondrogenic-related genes for each passage (P0-P5) of those cells were then analyzed using flow cytometry and quantitative real-time PCR, respectively. Flow cytometry analyses showed that, during the monolayer expansion, some qualitative and quantitative regulations occur for the expression of cell surface markers. A rapid increase in mRNA expression of type 1 collagen occurs whereas a significant decrease of type 2 collagen and Sox 9 was observed in chondrocytes through the successive passages. On the other hand, the expansion did not induced obvious change in MSCs gene expression. In conclusion, our results suggest that passage 1 might be the up-limit for chondrocytes in order to achieve their subsequent redifferentiation in 3D scaffold. Nevertheless, MSCs could be expanded in monolayer until passage 5 without loosing their undifferentiated phenotypes. 相似文献
963.
Nucleocapsid mutations turn HIV-1 into a DNA-containing virus 总被引:2,自引:1,他引:1
Houzet L Morichaud Z Didierlaurent L Muriaux D Darlix JL Mougel M 《Nucleic acids research》2008,36(7):2311-2319
964.
Richard D. Harvey Sandrine Bourgeois Peter Pietzonka Laurent Desire Elias Fattal 《NanoBioTechnology》2005,1(1):71-81
Nanoparticulate complexes of plasmid DNA (pDNA) with cationic liposomes/polymer, of approx 200 nm diameter, were encapsulated
with a high degree of efficiency within calcium pectinate gel beads. Electron microscopy showed the DNA nanocomplexes to be
evenly distributed throughout the gel matrix. Controlled release of pDNA-lipid nanocomplexes was achieved by the action of
pectinase enzymes, whereas release of naked and polymer-complexed DNA was found to be more greatly influenced by the swelling
behavior of the polysaccharide matrices in buffer alone. Physical degradation of pDNA within pectin beads was found to be
accelerated during bead drying, most probably as a result of shear forces generated within the gel matrices by the evaporation
of water. Plasmid complexation with cationic liposomes provided a greater degree of protection for the DNA during bead drying
than complexation with cationic polymer, and was shown to successfully transfect cultured cells after release from the beads,
via the action of pectinase. Observations concerning the physical stability of nanocomplexed pDNA, and its encapsulation within
and release from pectin gel beads, are discussed with reference to the electrostatic interactions existing between the various
components. 相似文献
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966.
967.
968.
Elaine Droucheau Aline Primot Virginie Thomas Denise Mattei Marie Knockaert Chris Richardson Pina Sallicandro Pietro Alano Ali Jafarshad Blandine Barrate Conrad Kunick Daniel Parzy Laurence Pearl Christian Doerig Laurent Meijer 《Biochimica et Biophysica Acta - Proteins and Proteomics》2004,1700(1):139-140
969.
Gondeau C Chaloin L Varga A Roy B Lallemand P Périgaud C Barman T Vas M Lionne C 《Biochemistry》2008,47(11):3462-3473
L-Nucleosides comprise a new class of antiviral and anticancer agents that are converted in vivo by a cascade of kinases to pharmacologically active nucleoside triphosphates. The last step of the cascade may be catalyzed by 3-phosphoglycerate kinase (PGK), an enzyme that has low specificity for nucleoside diphosphate (NDP): NDP + 1,3-bisphosphoglycerate <--> NTP + 3-phosphoglycerate. Here we compared the kinetics of the formation of the complexes of human PGK with d- and its mirror image l-ADP and the effect of 3-phosphoglycerate (PG) on these by exploiting the fluorescence signal of PGK that occurs upon its interaction with nucleotide substrate. Two types of experiment were carried out: equilibrium (estimation of dissociation constants) and stopped-flow (transient kinetics of the interactions). We show that under our experimental conditions (buffer containing 30% methanol, 4 degrees C) PGK binds d- and l-ADP with similar kinetics. However, whereas PG increased the dissociation rate constant for d-ADP by a factor of 8-which is a kinetic explanation for "substrate antagonism"-PG had little effect on this constant for l-ADP. We explain this difference by a molecular modeling study that showed that the beta-phosphates of d- and l-ADP have different orientations when bound to the active site of human PGK. The difference is unexpected because l-ADP is almost as catalytically competent as d-ADP [ Varga, A. et al. (2008) Biochem. Biophys. Res. Commun. 366, 994-1000]. 相似文献
970.
Laurent P. Rivory Stephen J. Clarke Michael Boyer James F. Bishop 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2001,765(2):135-140
A reversed-phase high-performance liquid chromatography method was developed and validated for the quantitation of pemetrexed (LY231514, ALIMTA) in human urine and plasma. Plasma samples were spiked with the internal standard lometrexol and extracted using Certify II columns. Pemetrexed was assayed in diluted urine by an external calibration method. A C8 column was used for the separation of analytes with a mobile phase composed of sodium formate buffer and acetonitrile. Between- and within-day precision and accuracy were acceptable down to the limit of quantitation of 5 ng/ml in plasma. This method was used successfully for an investigation of the disposition of pemetrexed in patients receiving 500 mg/m2 as a 10-min infusion. 相似文献