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191.
Dipanwita Sengupta Sujan Chatterjee Tania Chatterjee Kaustav Dutta Chowdhury Priya Bhowmick Udipta Chakraborti Avik Sarkar Soumosish Paul Pradip Kumar Sur Gobinda Chandra Sadhukhan 《Proceedings of the Zoological Society》2017,70(1):28-41
Oxidative stress is proposed to play a pivotal role in the development of hepatocellular carcinoma. With an accelerated metabolism cancer cells demand high reactive species accumulation to maintain their indiscriminate cell growth and proliferation. Here we wanted to see the status of reactive species in the chemically induced liver cancer. For this purpose swiss albino mice were exposed to DEN and CCl4 to develop an in vivo model of hepatocarcinoma. Depletion of cellular antioxidants regulated accretion of reactive species during the development of DEN + CCl4 induced tumor formation in hepatocytes. Currently available therapeutics for heptatocellular carcinoma is costly and coupled with certain bystander effects to the surrounding control cells. Therefore considering the antioxidant properties of SAC and berberine we treated DEN + CCl4 exposed mice after the development of liver tumor. Results effectively pointed out the usefulness of the alternative treatment with SAC and berberine in hepatoprotection. Replenishment of both enzymatic and non enzymatic antioxidant efficiently reduced accumulation of reactive species and that eventually closely associated with effective reduction in tumor number and size after drug treatment in DEN + CCl4 exposed mice. 相似文献
192.
193.
Procyclic Trypanosoma brucei cells were synchronized with 0.2 mM hydroxyurea. The cells did not arrest at the G1/S boundary but proceeded through one round of replication and arrested near the end of S phase. The mitochondrial genome (kinetoplast DNA network) replicated, forming two progeny networks, but the repair of minicircle gaps was inhibited. 相似文献
194.
Bacterial cell shape is, in part, mediated by the peptidoglycan (murein) sacculus. Penicillin-binding proteins (PBPs) catalyze the final stages of murein biogenesis and are the targets of beta-lactam antibiotics. Several low molecular mass PBPs including PBP4, PBP5, PBP6 and DacD seem to possess DD-carboxypeptidase (DD-CPase) activity, but these proteins are dispensable for survival in laboratory culture. The physiological functions of DD-CPases in vivo are unresolved and it is unclear why bacteria retain these seemingly non-essential and enzymatically redundant enzymes. However, PBP5 clearly contributes to maintenance of cell shape in some PBP mutant backgrounds. In this review, we focus on recent findings concerning the physiological functions of the DD-CPases in vivo, identify gaps in the current knowledge of these proteins and suggest some possible courses for future study that might help reconcile current models of bacterial cell morphology. 相似文献
195.
Ann Mander Ferdousi Chowdhury Lindsey Low Christian H. Ottensmeier 《Cancer immunology, immunotherapy : CII》2009,58(5):789-800
Clinical trials are governed by an increasingly stringent regulatory framework, which applies to all levels of trial conduct.
Study critical immunological endpoints, which define success or failure in early phase clinical immunological trials, require
formal pre-trial validation. In this case study, we describe the assay validation process, during which the sensitivity, and
precision of immunological endpoint assays were defined. The purpose was the evaluation of two multicentre phase I/II clinical
trials from our unit in Southampton, UK, which assess the effects of DNA fusion vaccines on immune responses in HLA-A2+ patients
with carcinoembryonic antigen (CEA)-expressing malignancies and prostate cancer. Validated immunomonitoring is being performed
using ELISA and IFNγ ELISPOTs to assess humoral and cellular responses to the vaccines over time. The validated primary endpoint
assay, a peptide-specific CD8+ IFNγ ELISPOT, was tested in a pre-trial study and found to be suitable for the detection of
low frequency naturally occurring CEA- and prostate-derived tumour-antigen-specific T cells in patients with CEA-expressing
malignancies and prostate cancer.
This paper is a Focussed Research Review based on a presentation given at the Sixth Annual Meeting of the Association for
Immunotherapy of Cancer (CIMT), held in Mainz, Germany, 15–16 May 2008. 相似文献
196.
Stephen P. East Clara Bantry White Oliver Barker Stephanie Barker James Bennett David Brown E. Andrew Boyd Christopher Brennan Chandana Chowdhury Ian Collins Emmanuelle Convers-Reignier Brian W. Dymock Rowena Fletcher David J. Haydon Mihaly Gardiner Stuart Hatcher Peter Ingram Paul Lancett Paul Mortenson Konstantinos Papadopoulos Lloyd G. Czaplewski 《Bioorganic & medicinal chemistry letters》2009,19(3):894-899
The synthesis and antibacterial activities of three chemotypes of DNA supercoiling inhibitors based on imidazolo[1,2-a]pyridine and [1,2,4]triazolo[1,5-a]pyridine scaffolds that target the ATPase subunits of DNA gyrase and topoisomerase IV (GyrB/ParE) is reported. The most potent scaffold was selected for optimization leading to a series with potent Gram-positive antibacterial activity and a low resistance frequency. 相似文献
197.
Khaled R.A. Abdellatif Morshed Alam Chowdhury Ying Dong Dipankar Das Gang Yu Carlos Velázquez Mavanur R. Suresh Edward E. Knaus 《Bioorganic & medicinal chemistry》2009,17(14):5182-5188
A new class of hybrid nitric oxide-releasing anti-inflammatory (AI) ester prodrugs (NONO-coxibs) wherein an O2-acetoxymethyl-1-(N-ethyl-N-methylamino)diazen-1-ium-1,2-diolate (13a–b), or O2-acetoxymethyl-1-(2-methylpyrrolidin-1-yl)diazen-1-ium-1,2-diolate (16a–b), NO-donor moiety was covalently coupled to the COOH group of 5-(4-carboxymethylphenyl)-1-(4-methane(amino)sulfonylphenyl)-3-trifluoromethyl-1H-pyrazole (11a–b) was synthesized. The percentage of NO released from these diazen-1-ium-1,2-diolates was significantly higher (59.6–74.6% of the theoretical maximal release of 2 molecules of NO/molecule of the parent hybrid ester prodrug) upon incubation in the presence of rat serum, relative to incubation with phosphate buffer (PBS) at pH 7.4 (5.0–7.2% range). These incubation studies suggest that both NO and the AI compound would be released from the parent NONO-coxib upon in vivo cleavage by non-specific serum esterases. All compounds were weak inhibitors of the COX-1 isozyme (IC50 = 8.1–65.2 μM range) and modest inhibitors of the COX-2 isozyme (IC50 = 0.9–4.6 μM range). The most potent parent aminosulfonyl compound 11b exhibited AI activity that was about sixfold greater than that for aspirin and threefold greater than that for ibuprofen. The ester prodrugs 13b, 16b exhibited similar AI activity to that exhibited by the more potent parent acid 11b when the same oral μmol/kg dose was administered. These studies indicate hybrid ester AI/NO donor prodrugs of this type (NONO-coxibs) constitute a plausible drug design concept targeted toward the development of selective COX-2 inhibitory AI drugs that are devoid of adverse cardiovascular effects. 相似文献
198.
199.
Sudeshna Chowdhury Shakuntala Ghorai Samudra Prosad Banik Swagata Pal Soumen Basak Suman Khowala 《Process Biochemistry》2009,44(10):1075-1082
An extracellular sucrase from the culture filtrate of filamentous basidiomycota Termitomyces clypeatus grown on high sucrose (5%, w/v) was purified by gel filtration chromatography, ion exchange chromatography and HPGPLC. The biochemical properties, molecular weight and conformation of sucrase produced were significantly different from the sucrase earlier purified from sucrose (1%, w/v) medium in the fungus. Purified sucrase was characterized as a low molecular weight protein of 13.5 kDa as approximated by SDS-PAGE and HPGPLC and exhibited predominantly random coil conformation in far-UV CD spectra. The enzyme was optimally active at 47 °C and pH 5.0. Km and catalytic activity of the enzyme for sucrose were found to be 3.5 mM and 1.06 U/mg/mM, respectively. The enzyme was maximally active towards sucrose than to raffinose and sucrase activity was significantly inhibited by bivalent metal ions and reducing group agents. The results indicated that due to changes in aggregation pattern, molecular organization of purified sucrase, produced in high sucrose medium, was altered and was different from the previously reported enzyme. This is the first report of a sucrase of such low size showing activity. 相似文献
200.
The performance of a liquid–solid circulating fluidized bed bioreactor (LSCFB) with anoxic and aerobic beds and lava rock as a biofilm carrier media was used to investigate the impact of the COD/N ratio on the process performance, with particular focus on total nitrogen removal. Three different COD/N ratios of 10:1, 6:1 and 4:1 were tested at an empty bed contact time of 0.82 h. More than 90% of the influent organic matter was removed throughout the study with 58% removal in the anoxic column in Phase III. Total nitrogen removal efficiencies in Phases I–III were 91%, 82% and 71% and simultaneous nitrification–denitrification (SND) occurred in the aerobic downer. The LSCFB demonstrated tertiary effluent quality at COD/N ratio of 10:1 and 6:1 with soluble biochemical oxygen demand (SBOD) <10 mg l?1 and total nitrogen (TN) <10 mg l?1. 相似文献