首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   308篇
  免费   16篇
耳鼻咽喉   9篇
儿科学   5篇
妇产科学   12篇
基础医学   68篇
口腔科学   3篇
临床医学   13篇
内科学   48篇
皮肤病学   2篇
神经病学   26篇
特种医学   2篇
外科学   43篇
综合类   2篇
预防医学   14篇
眼科学   1篇
药学   67篇
中国医学   2篇
肿瘤学   7篇
  2023年   5篇
  2022年   4篇
  2021年   21篇
  2020年   5篇
  2019年   5篇
  2018年   8篇
  2017年   8篇
  2016年   6篇
  2015年   9篇
  2014年   10篇
  2013年   17篇
  2012年   17篇
  2011年   25篇
  2010年   10篇
  2009年   16篇
  2008年   18篇
  2007年   9篇
  2006年   13篇
  2005年   11篇
  2004年   9篇
  2003年   11篇
  2002年   10篇
  2001年   11篇
  2000年   6篇
  1999年   3篇
  1997年   2篇
  1996年   2篇
  1994年   1篇
  1993年   2篇
  1992年   8篇
  1991年   3篇
  1990年   2篇
  1989年   5篇
  1988年   2篇
  1987年   2篇
  1985年   3篇
  1983年   3篇
  1982年   1篇
  1980年   3篇
  1979年   2篇
  1978年   6篇
  1976年   1篇
  1975年   2篇
  1972年   1篇
  1971年   1篇
  1970年   2篇
  1969年   1篇
  1968年   1篇
  1965年   1篇
排序方式: 共有324条查询结果,搜索用时 15 毫秒
51.
52.
Unsatisfactory clinical efficacy and a variety of adverse effects of current antidepressant drugs have incited search for better therapy. Zinc, an antagonist of the glutamate/N-methyl-D-aspartate (NMDA) receptor, exhibits antidepressant-like activity in rodent tests/models of depression. Similarly to antidepressants, zinc induces brain derived neurotrophic factor (BDNF) gene expression and increases level of synaptic pool of zinc in the hippocampus. Clinical observations demonstrated serum hypozincemia in depression, which was normalized by effective antidepressant treatment. Moreover, our preliminary clinical study demonstrated the benefit of zinc supplementation in antidepressant therapy. All the data indicate the important role of zinc homeostasis in psychopathology and therapy of depression and potential clinical antidepressant activity of this ion.  相似文献   
53.
Phosphatidylethanol (PEth) is a direct biomarker for alcohol consumption consisting of a fraction of different ethanol-modified, homologue phospholipids. The aim of this study was to validate an ultra-high-performance liquid chromatography–tandem mass spectrometry method to quantitate six different homologues of PEth (16:0/18:1, 16:0/18:2, 16:0/20:4, 18:0/18:1, 18:0/18:2, and 18:1/18:1) from dried blood spots (DBSs). DBSs were prepared volumetrically (20 μL of whole blood) and extracted with 1 mL of methanol (0.02 ng/μL internal standards). PEth homologues were separated on a BEH C18 column (2.1 × 150 mm, 1.7 μm) using methanol and ammonium acetate buffer (25 mM) in a 7 min isocratic run. Multiple reaction monitoring mode was used for the detection of PEth and the internal standards. Calibrators (10–1000 ng/mL) and quality controls (40, 400, and 700 ng/mL) were prepared from spiked whole blood; external control samples were obtained from proficiency testing schemes. After a comprehensive validation of the method, quantitative patterns of the different homologues were investigated in PEth positive samples (n = 57) from patients in a transplant setting. Satisfactory chromatographic separation, sensitive detection, and reliable quantification of the PEth homologues in DBSs can be achieved using the liquid chromatography–tandem mass spectrometry (LC/MS/MS) procedure. Validation results, including accuracy, linearity, recovery, matrix effects, and in-process stability, complied with international standards, and the analytical performance of the procedure was not affected by the hematocrit of the blood samples. Different quantitative patterns of the investigated PEth homologues were observed in authentic samples from liver transplant patients. This method will enable the study of the kinetics of six PEth homologues simultaneously and investigate the meaning of the homologues' distribution in individuals.  相似文献   
54.
Inflammation Research - A tumor growth depends on the potency of the tumor to support itself with nutrients and oxygen. The development of a vascular network within the tumor is key to its...  相似文献   
55.
56.
Roman Szewczyk 《Materials》2014,7(7):5109-5116
The paper presents results of validation of the anhysteretic magnetization model for a soft amorphous alloy with significant perpendicular anisotropy. The validation was carried out for the Jiles-Atherton model with Ramesh extension considering anisotropy. Due to the fact that it is difficult to measure anhysteretic magnetization directly, the soft magnetic core with negligible hysteresis was used. The results of validation indicate that the Jiles-Atherton model with Ramesh extension should be corrected to allow accurate modeling of the anhysteretic magnetization. The corrected model may be applied for modeling the cores of current transformers operating in a wide range of measured currents.  相似文献   
57.
In this paper, an antimycobacterial component of extracellular metabolites of a gut bacterium Raoultella ornithinolytica from D. veneta earthworms was isolated and its antimycobacterial action was tested using Mycobacterium smegmatis. After incubation with the complex obtained, formation of pores and furrows in cell walls was observed using microscopic techniques. The cells lost their shape, stuck together and formed clusters. Surface‐enhanced Raman spectroscopy analysis showed that, after incubation, the complex was attached to the cell walls of the Mycobacterium. Analyses of the component performed with Fourier transform infrared spectroscopy demonstrated high similarity to a bacteriocin nisin, but energy dispersive X‐ray spectroscopy analysis revealed differences in the elemental composition of this antimicrobial peptide. The component with antimycobacterial activity was identified using mass spectrometry techniques as a glycolipid–peptide complex. As it exhibits no cytotoxicity on normal human fibroblasts, the glycolipid–peptide complex appears to be a promising compound for investigations of its activity against pathogenic mycobacteria.  相似文献   
58.
Background  This study was undertaken to analyze subsets of lymphocytes in peripheral blood in the early phase and in the thyroid tissue in the late phase of Graves’ disease (GD) in children. Methods  The study included 30 children with GD and 30 healthy children. Monoclonal antibodies were used to define peripheral blood lymphocyte subsets and they were analyzed using the flow cytometer Ortho Diagnostic System. After thyroidectomy, T cells were detected by CD3, CD4, CD8 antibodies, B cells by CD79α antibodies, and the antigen presenting dendritic cells (APCs) by CD1α antibodies (DakoCytomation) in the thyroid tissue. Results  Before the treatment, an increased percentage of CD4+ T helper cells and B cells and decreased CD8+ T suppressor/cytotoxic cells were observed in peripheral blood in all the GD children. The number of lymphocytes and dendritic cells in the thyroid tissue increased in the children with GD in comparison to the control group, especially T cells subsets CD4+ and CD8+ and CD79α+ B cells. The percentage of T cells in the thyroid tissue was lower and that of B cells was higher than in peripheral blood. In their structure, thyrocytes can have components similar to α-chains connected with β-microglobulins, which were characteristic for APCs. Conclusions  The primary defect of immunoregulation in children with GD is probably dependent on a large number and the activity of T helper cells and on a small number and hypofunction of T suppressor cells. The amount of lymphocytes decreased proportionally to the duration of methimazole treatment. The thyrocytes probably can present antigens.  相似文献   
59.
8-Methoxypsoralen (8-MOP) stimulated insulin release from HIT-T15 B-cells and inhibited the diazoxide-induced and sulfonylurea-sensitive 86Rb+ efflux from these cells. These results indicate that 8-MOP affects ATP-sensitive K+ channel activity. Patch-clamp experiments confirmed this view.  相似文献   
60.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号