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971.
Datta P Mukhopadhyay AP Manna P Tiekink ER Sil PC Sinha C 《Journal of inorganic biochemistry》2011,105(4):577-588
N-[(2-Pyridyl)methyliden]-6-coumarin (L) is synthesized by the condensation of 6-aminocoumarin and pyridine-2-carboxaldehyde. Group-6 tetracarbonyl complexes, [M(CO)4(L)] (M = Cr, Mo, and W) are synthesized and characterized by mass spectrometry and NMR, FT-IR and UV-visible spectroscopy. X-ray crystal structure of [Cr(CO)4(L)] shows N(pyridine), N(imine) chelation to chromium(0). A supramolecular chain is formed by C-H?O and π?π interactions. The ligand and the complexes are fluorescent. Cyclic voltammetry of the complexes exhibit quasireversible M(I)/M(0) redox couple. The complexes exhibit potential antioxidant property both in cell free and in-vitro studies and highest activity is observed to [W(CO)4(L)]. Density functional theory (DFT) computation has been performed to correlate with the electronic configuration, composition of wave functions with the UV-visible spectra and redox properties. 相似文献
972.
Anupam R Datta A Kesic M Green-Church K Shkriabai N Kvaratskhelia M Lairmore MD 《The Journal of biological chemistry》2011,286(9):7661-7668
Human T-lymphotropic virus type 1 (HTLV-1) is a causative agent of adult T cell leukemia/lymphoma and a variety of inflammatory disorders. HTLV-1 encodes a nuclear localizing protein, p30, that selectively alters viral and cellular gene expression, activates G(2)-M cell cycle checkpoints, and is essential for viral spread. Here, we used immunoprecipitation and affinity pulldown of ectopically expressed p30 coupled with mass spectrometry to identify cellular binding partners of p30. Our data indicate that p30 specifically binds to cellular ATM (ataxia telangiectasia mutated) and REGγ (a nuclear 20 S proteasome activator). Under conditions of genotoxic stress, p30 expression was associated with reduced levels of ATM and increased cell survival. Knockdown or overexpression of REGγ paralleled p30 expression, suggesting an unexpected enhancement of p30 expression in the presence of REGγ. Finally, size exclusion chromatography revealed the presence of p30 in a high molecular mass complex along with ATM and REGγ. On the basis of our findings, we propose that HTLV-1 p30 interacts with ATM and REGγ to increase viral spread by facilitating cell survival. 相似文献
973.
Yadav S Aneja R Kumar P Datt M Sinha S Sahni G 《The Journal of biological chemistry》2011,286(8):6458-6469
To identify new structure-function correlations in the γ domain of streptokinase, mutants were generated by error-prone random mutagenesis of the γ domain and its adjoining region in the β domain followed by functional screening specifically for substrate plasminogen activation. Single-site mutants derived from various multipoint mutation clusters identified the importance of discrete residues in the γ domain that are important for substrate processing. Among the various residues, aspartate at position 328 was identified as critical for substrate human plasminogen activation through extensive mutagenesis of its side chain, namely D328R, D328H, D328N, and D328A. Other mutants found to be important in substrate plasminogen activation were, namely, R319H, N339S, K334A, K334E, and L335Q. When examined for their 1:1 interaction with human plasmin, these mutants were found to retain the native-like high affinity for plasmin and also to generate amidolytic activity with partner plasminogen in a manner similar to wild type streptokinase. Moreover, cofactor activities of the mutants precomplexed with plasmin against microplasminogen as the substrate as well as in silico modeling studies suggested that the region 315-340 of the γ domain interacts with the serine protease domain of the macromolecular substrate. Overall, our results identify the presence of a substrate specific exosite in the γ domain of streptokinase. 相似文献
974.
Torres-Bacete J Sinha PK Matsuno-Yagi A Yagi T 《The Journal of biological chemistry》2011,286(39):34007-34014
The proton-translocating NADH-quinone oxidoreductase (complex I/NDH-1) is a multisubunit enzymatic complex. It has a characteristic L-shaped form with two domains, a hydrophilic peripheral domain and a hydrophobic membrane domain. The membrane domain contains three antiporter-like subunits (NuoL, NuoM, and NuoN, Escherichia coli naming) that are considered to be involved in the proton translocation. Deletion of either NuoL or NuoM resulted in an incomplete assembly of NDH-1 and a total loss of the NADH-quinone oxidoreductase activity. We have truncated the C terminus segments of NuoM and NuoL by introducing STOP codons at different locations using site-directed mutagenesis of chromosomal DNA. Our results suggest an important structural role for the C-terminal segments of both subunits. The data further advocate that the elimination of the last transmembrane helix (TM14) of NuoM and the TM16 (at least C-terminal seven residues) or together with the HL helix and the TM15 of the NuoL subunit lead to reduced stability of the membrane arm and therefore of the whole NDH-1 complex. A region of NuoL critical for stability of NDH-1 architecture has been discussed. 相似文献
975.
976.
Miah AG Salma U Sinha PB Hölker M Tesfaye D Cinar MU Tsujii H Schellander K 《Animal reproduction science》2011,125(1-4):30-41
Relaxin is one of the 6-kDa peptide hormones, which acts as a pleiotropic endocrine and paracrine factor. Our previous studies revealed that sperm capacitating medium containing relaxin induced capacitation and acrosome reaction (AR) in fresh and frozen-thawed porcine or bovine spermatozoa. However, the intracellular signaling cascades involved with capacitation or AR induced by relaxin was unknown. Therefore, the present study was designed to investigate the intracellular signaling cascades involved with capacitation and AR induced by relaxin in fresh and frozen-thawed bovine spermatozoa. Spermatozoa were incubated in sperm Tyrode's albumin lactate pyruvate (Sp-TALP) medium supplemented with (40 ng ml(-1)) or without relaxin, and subjected to evaluation of chlortetracycline staining pattern, cholesterol efflux, Ca(2+)-influx, intracellular cyclic adenosine monophosphate (cAMP) and protein tyrosine phosphorylation. Capacitation and AR were increased (P<0.05) in both fresh and frozen-thawed spermatozoa incubated with relaxin. Cholesterol effluxes were greater in the fresh (P<0.01) and frozen-thawed (P<0.05) spermatozoa incubated with relaxin than the spermatozoa incubated without relaxin. Ca(2+)-influxes were also significantly stimulated by relaxin in the fresh (P<0.01) and frozen-thawed (P<0.05) spermatozoa. The Sp-TALP medium containing relaxin influenced the generation of intracellular cAMP in the fresh (P<0.01) and frozen-thawed (P<0.05) spermatozoa, and exhibited higher exposure of protein tyrosine phosphorylation in both sperm types than the medium devoid of relaxin. Therefore, the results postulate that relaxin exerts the intracellular signaling cascades involved with capacitation and AR through accelerating the cholesterol efflux, Ca(2+)-influx, intracellular cAMP and protein tyrosine phosphorylation in fresh and frozen-thawed bovine spermatozoa. 相似文献
977.
Shyam Sundar Sharma Madan Singh Negi Pratima Sinha Kamlesh Kumar Shashi Bhushan Tripathi 《Plant Molecular Biology Reporter》2011,29(1):12-18
Efficacy of two dominant molecular markers, namely, amplified fragment length polymorphism (AFLP) and three endonuclease (TE)-AFLP,
were assessed in 20 individuals of the biodiesel species Pongamia pinnata. Four primer combinations generated a total of 254 and 194 bands in AFLP and TE-AFLP, respectively. Both techniques could
unequivocally identify each accession used in this study. The Jaccard’s similarity coefficient ranged from 0.30 to 0.90 for
AFLP and from 0.25 to 0.85 for TE-AFLP. The correlation coefficient between AFLP and TE-AFLP dendrogram was 0.56 which was
low but significant (P < 0.001). Values of effective multiplex ratio, marker index, and resolving power were markedly higher in AFLP than in TE-AFLP.
However, the band intensities across different lanes were uniform in TE-AFLP leading to easy and accurate scoring of gels
which resulted in slightly higher bootstrap values with TE-AFLP data as compared to AFLP data. Inferences based on TE-AFLP
data had similar level of biological relevance as compared to AFLP data when location and diameter of trees were taken in
to consideration. However, the easy scorability of TE-AFLP profiles is extremely important and especially desirable in studies
requiring genotyping of large number of individuals distributed across many gels. 相似文献
978.
979.
Sujata Sharma Amit Kumar Singh Sanket Kaushik Mau Sinha Rashmi Prabha Singh Pradeep Sharma Harshverdhan Sirohi Punit Kaur Tej P Singh 《International Journal of Biochemistry and Molecular Biology》2013,4(3):108-128
Lactoperoxidase (LPO) is a member of a large group of mammalian heme peroxidases that include myeloperoxidase (MPO), eosinophil peroxidase (EPO) and thyroid peroxidase (TPO). The LPO is found in exocrine secretions including milk. It is responsible for the inactivation of a wide range of micro-organisms and hence, is an important component of defense mechanism in the body. With the help of hydrogen peroxide, it catalyzes the oxidation of halides, pseudohalides and organic aromatic molecules. Historically, LPO was isolated in 1943, nearly seventy years ago but its three-dimensional crystal structure has been elucidated only recently. This review provides various details of this protein from its discovery to understanding its structure, function and applications. In order to highlight species dependent variations in the structure and function of LPO, a detailed comparison of sequence, structure and function of LPO from various species have been made. The structural basis of ligand binding and distinctions in the modes of binding of substrates and inhibitors have been analyzed extensively. 相似文献
980.
Suman Bhattacharya Rajeshwary Ghosh Smarajit Maiti Gausal Azam Khan Asru K. Sinha 《PloS one》2013,8(12)