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   1510篇
  免费   94篇
  国内免费   8篇
耳鼻咽喉   12篇
儿科学   71篇
妇产科学   21篇
基础医学   170篇
口腔科学   19篇
临床医学   174篇
内科学   237篇
皮肤病学   19篇
神经病学   82篇
特种医学   103篇
外国民族医学   1篇
外科学   241篇
综合类   136篇
预防医学   146篇
眼科学   10篇
药学   101篇
肿瘤学   69篇
  2021年   40篇
  2020年   12篇
  2019年   17篇
  2018年   18篇
  2017年   9篇
  2016年   11篇
  2015年   19篇
  2014年   33篇
  2013年   36篇
  2012年   43篇
  2011年   52篇
  2010年   40篇
  2009年   42篇
  2008年   64篇
  2007年   55篇
  2006年   54篇
  2005年   51篇
  2004年   61篇
  2003年   53篇
  2002年   33篇
  2001年   37篇
  2000年   33篇
  1999年   33篇
  1998年   49篇
  1997年   33篇
  1996年   42篇
  1995年   29篇
  1994年   40篇
  1993年   20篇
  1992年   36篇
  1991年   19篇
  1990年   34篇
  1989年   35篇
  1988年   40篇
  1987年   32篇
  1986年   44篇
  1985年   44篇
  1984年   25篇
  1983年   22篇
  1982年   17篇
  1981年   16篇
  1980年   12篇
  1979年   30篇
  1978年   17篇
  1977年   13篇
  1976年   15篇
  1975年   16篇
  1972年   9篇
  1970年   9篇
  1969年   10篇
排序方式: 共有1612条查询结果,搜索用时 405 毫秒
1.
BackgroundRural populations face many health disadvantages compared to urban areas. There is a critical need to better understand the current lung cancer screening landscape in these communities to identify targeted areas to improve the impact of this proven tool.MethodsData from the County Health Rankings of New Hampshire and Vermont was reviewed for population density, distribution of adult smokers, and level of education compared to the distribution of Lung Cancer Screening Facilities throughout these two states.ResultsScreening programs in southern counties of Vermont with lower levels of education have decreased access. In New Hampshire, there are no programs within 30 miles of the areas with the largest distribution of smokers, and decreased access in some areas with the lowest levels of education.ConclusionsImproving equitable access to high-quality screening services in rural regions and the creation of targeted interventions to address decreased access in areas of high tobacco use and low education is vital to decreasing the incidence of latestage presentations of lung cancer within these populations.  相似文献   
2.
3.
A variant left hepatic artery occurs at a rate of approximately 10%. In standard esophagogastrectomy and some proximal gastric operations this variant artery is sacrificed, which has led to reported fatalities secondary to hepatic necrosis. We report our method of esophagogastrectomy in the presence of an aberrant left hepatic artery.  相似文献   
4.
We have devised assays to detect both circulating alloantibodies to platelets (indirect assay) and platelet-association IgG and IgM (direct assay) using a flow cytometric technique. A variety of patients with immune thrombocytopenia were studied. Employment of a confocal lens in the flow cytometer increased the discrimination power of the instrument. Patients with autoimmune thrombocytopenia (idiopathic thrombocytic purpura [ITP], systemic lupus erythematosus (SLE), lymphoma, leukemia, and drug-induced thrombocytopenia showed a significant increase in platelet-associated antibody. Circulating antibodies to platelets (alloantibodies) were demonstrated in cases of platelet refractoriness and neonatal isoimmune purpura. Day-today precision of the assays ranged from 3% to 6% (coefficient of variation). No interference was shown in the presence of hemoglobin (5 g/L), triglycerides (10 g/L), or polyclonal and monoclonal immunoglobulinemia (50 g/L: IgG, IgA, IgM). The sensitivity of the direct assay was 500 attograms of IgG or IgM platelet.  相似文献   
5.
6.
7.
In order to evaluate the effects of pentoxifylline on sperm motility and longevity, a controlled in-vitro study was conducted on normozoospermic donor semen samples using the Cellsoft automated system for sperm motility analysis. After incubation and selection, pentoxifylline was found to improve the recovery of spermatozoa and to increase their velocity. In the subgroup of progressively motile spermatozoa, curvilinear velocity was also enhanced. It is concluded that pentoxifylline has an effect on the vigour, but not on the pattern, of sperm motion. Pentoxifylline did not improve the motility characteristics of senescent spermatozoa in normozoospermic sperm samples. Sperm survival, as shown by supra-vital staining, and motility longevity both decreased with time after pentoxifylline treatment.  相似文献   
8.
A study of 17 patients with autoimmune axonal or demyelinating peripheral neuropathy in combination with M-component is described. The M-component was associated with MGUS (monoclonal gammopathy of undetermined significance) in 12 patients, CLL in one patient, WaldenstrÖm's disease in one patient, and myeloma in three patients. Immunohistological examination with direct and indirect fluorescence showed binding of antibodies to nerve structures of the same class and light chain as seen in the M-component. In five cases of IgM M-component, the demyelinating neuropathy was caused by binding of the IgM M-protein and complement C3b to myelin-associated glycoproteins (MAG). In 12 cases with axonal neuropathy, binding of IgG to the connective tissue of the peri- and endoneurium was found in 50% of cases, IgM in five cases, and IgD in one case. None of the patients had central nervous system (CNS) symptoms. The clinical and therapeutic difficulties are discussed; only two patients with an acute course responded to immunosuppression. A marked co-expression of other autoimmune phenomena is interpreted in the light of cross-reactions between the autoantibody and similar tissue autoantigens.  相似文献   
9.
10.
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