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Anna Bogdanova Jeroen S. Goede Erwin Weiss Nikolay Bogdanov Poul Bennekou Ingolf Bernhardt Hans U. Lutz 《Haematologica》2010,95(2):189-198
Background
Cryohydrocytosis is an inherited dominant hemolytic anemia characterized by mutations in a transmembrane segment of the anion exchanger (band 3 protein). Transfection experiments performed in Xenopus oocytes suggested that these mutations may convert the anion exchanger into a non-selective cation channel. The present study was performed to characterize so far unexplored ion transport pathways that may render erythrocytes of a single cryohydrocytosis patient cation-leaky.Design and Methods
Cold-induced changes in cell volume were monitored using ektacytometry and density gradient centrifugation. Kinetics, temperature and inhibitor-dependence of the cation and water movements in the cryohydrocytosis patient’s erythrocytes were studied using radioactive tracers and flame photometry. Response of the membrane potential of the patient’s erythrocyte membrane to the presence of ionophores and blockers of anion and cation channels was assessed.Results
In the cold, the cryohydrocytosis patient’s erythrocytes swelled in KCl-containing, but not in NaCl-containing or KNO3-containing media indicating that volume changes were mediated by an anion-coupled cation transporter. In NaCl-containing medium the net HOE-642-sensitive Na+/K+ exchange prevailed, whereas in KCl-containing medium swelling was mediated by a chloride-dependent K+ uptake. Unidirectional K+ influx measurements showed that the patient’s cells have abnormally high activities of the cation-proton exchanger and the K+,Cl− co-transporter, which can account for the observed net movements of cations. Finally, neither chloride nor cation conductance in the patient’s erythrocytes differed from that of healthy donors.Conclusions
These results suggest that cross-talk between the mutated band 3 and other transporters might increase the cation permeability in cryohydrocytosis. 相似文献94.
奥扎格雷纳米结构脂质载体的制备及体外评价 总被引:1,自引:0,他引:1
目的:制备奥扎格雷纳米结构脂质载体(ozagrel-loaded nanostructured lipid carriers,OZ-NLC),并考察其理化性质及体外释放。方法:采用熔融-超声乳化法制备OZ-NLC,通过正交设计法优化处方与制备工艺,使用透射电镜(TEM)、激光粒度测定仪、差示扫描量热仪(DSC)及X-射线衍射仪(XRD)考察OZ-NLC的理化性质,通过溶出试验评价其体外释放效果。结果:所制备的OZ-NLC呈球形或类球形;平均粒径为(115±10)nm;Zeta电位为(-37.6±8.9)mV;平均包封率为(61.3±5.2)%;XRD与DSC表明药物以无定形形式分散于OZ-NLC中。与奥扎格雷混悬液相比,OZ-NLC的体外溶出量明显提高且具有很好的缓释效果。结论:熔融-超声乳化法制备的OZ-NLC对促进难溶性药物奥扎格雷的口服吸收具有一定的指导价值。 相似文献
95.
智能纳米水凝胶在药物输送与可控释放、医学诊断、生物传感器、微反应器、催化剂载体等方面有良好的应用前景。结合本课题组近年来的研究成果,分别介绍了具有温度刺激响应性、pH刺激响应性、光刺激响应性、磁场刺激响应性、分子识别刺激响应性和多重刺激响应性智能纳米水凝胶的研究进展。另外,对这几种智能纳米水凝胶目前存在的问题和今后的发展方向提出了一些粗浅的看法。 相似文献
96.
目的综述聚乙二醇1000维生素E琥珀酸酯(D-α-tocopherol polyethylene glycol 1000 succi-nate,TPGS)在各种纳米制剂中的最新进展。方法查阅国内外相关文献共48篇,对这些文献进行分析、概括和总结。结果 TPGS能够提高药物包封率和细胞吸收,改善药物释放,提高药物生物利用度,并能协同起抗癌疗效。广泛应用于聚合物纳米粒、聚合物胶束、纳米脂质体、纳米药物等纳米给药系统中。结论 TPGS在纳米制剂中有着良好应用前景。 相似文献
97.
Several viral factors are associated with disease progression in hepatitis B virus (HBV) carriers. Compared with Taiwanese Han Chinese, Taiwanese aborigines have a higher prevalence of chronic HBV infection and a higher standardized mortality rate of chronic liver diseases but a lower standardized mortality rate of hepatocellular carcinoma (HCC). The aim of this study was to investigate whether aboriginal Taiwanese HBV carriers have more favorable viral factors which reduce the risk for HCC than Han Chinese carriers. Blood samples from 3,488 HBV carriers (1,527 aborigines and 1,961 Han Chinese) were assayed for aminotransferases, hepatitis B e antigen (HBeAg), HBV DNA, and HBV genotype. Aboriginal HBV carriers had a lower HBeAg‐positive rate (5.3% vs. 10.2%, P < 0.0001) and a lower viral load of HBV DNA > 2,000 IU/ml (27.4% vs. 36.7%, P < 0.0001) but a higher rate of alcohol consumption (40.0% vs. 19.3%, P < 0.0001) than Han Chinese carriers. The prevalence of HBV genotype B in aboriginal carriers (92.7%) was significantly higher than that in Han Chinese carriers (72.7%) in all age groups (P < 0.05). In addition, patients with rare genotype D infections were clustered in a township in southern Taiwan. In conclusion, aboriginal Taiwanese HBV carriers have more favorable viral factors than Han Chinese carriers, which may be partly responsible for the lower standardized mortality rate of HCC in Taiwanese aborigines. J. Med. Virol. 83:1326–1331, 2011. © 2011 Wiley‐Liss, Inc. 相似文献
98.
Sonja Theisinger Katrin Schoeller Barry Osborn Manish Sarkar Katharina Landfester 《Macromolecular chemistry and physics.》2009,210(6):411-420
The encapsulation of the hydrophobic fragrance 1,2‐dimethyl‐1‐phenyl‐butyramide (DMPBA), a typical C9 amide, in poly(methyl methacrylate), polystyrene, or acrylic copolymer nanoparticles can easily be obtained using a one‐step miniemulsion process. It is shown that this hydrophobic compound directly influences the kinetics, the molecular weight, and the morphology of the nanocapsule formation. The release behavior can be tuned by the temperature in relation to the Tg of the polymer which makes these nanocapsules interesting candidates for temperature‐dependent delivery systems.
99.
Julius Paul Pradeep John Berta Sunyer Harald Höger Arnold Pollak Gert Lubec 《Hippocampus》2009,19(8):731-738
Synapsins are essential proteins for synaptic plasticity and there is no information available for their role in cognitive enhancement (CE) of spatial memory formation. It was therefore the aim of the study to link individual synapsin proteins and their isoforms to spatial memory formation enhanced by SGS742 in the mouse. Extracted hippocampal proteins from a cognitive study treating OF1 mice with the cognitive enhancer SGS742 and tested in the Morris water maze, were run on two‐dimensional gel electrophoresis. Subsequently, protein spots were unambiguously identified by qQ‐TOF mass spectrometry. Quantification of proteins from four groups (NaCl‐treated mice, SGS742‐treated mice, SGS742‐treated yoked controls, and NaCl‐treated yoked controls) was carried out according to an in‐gel stable isotope labeling method. A total of 17 protein spots representing synapsin isoforms were identified and quantified. Using quantification of individual synapsin isoforms showed that these can be clearly assigned to CE by the GABAB antagonist SGS742. Quantitative determination of individual synapsin isoform showed an increase in SGS742‐treated mice (mean ± SD) of ratios between light and heavy stable isotope labeled synapsin protein (SGS742 vs. controls: 2.19 ± 0.41 for synapsin Ia, and 1.41 ± 0.81 for synapsin IIa). Synapsins Ib and IIb were not linked to CE. The NaCl‐treated controls and the use of yoked controls that were ruling out swimming‐ and stress‐mediated changes of synapsins, unequivocally allow to propose a role for synapsins Ia and IIa in the mechanism of CE of spatial memory formation. © 2009 Wiley‐Liss, Inc. 相似文献
100.