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   2483篇
  免费   221篇
  国内免费   163篇
耳鼻咽喉   29篇
儿科学   62篇
妇产科学   15篇
基础医学   332篇
口腔科学   56篇
临床医学   321篇
内科学   313篇
皮肤病学   35篇
神经病学   211篇
特种医学   132篇
外国民族医学   5篇
外科学   258篇
综合类   327篇
预防医学   169篇
眼科学   59篇
药学   275篇
  1篇
中国医学   125篇
肿瘤学   142篇
  2024年   6篇
  2023年   41篇
  2022年   94篇
  2021年   117篇
  2020年   90篇
  2019年   81篇
  2018年   78篇
  2017年   78篇
  2016年   67篇
  2015年   101篇
  2014年   142篇
  2013年   121篇
  2012年   186篇
  2011年   184篇
  2010年   118篇
  2009年   109篇
  2008年   137篇
  2007年   145篇
  2006年   128篇
  2005年   115篇
  2004年   99篇
  2003年   74篇
  2002年   75篇
  2001年   48篇
  2000年   54篇
  1999年   47篇
  1998年   38篇
  1997年   39篇
  1996年   26篇
  1995年   30篇
  1994年   31篇
  1993年   21篇
  1992年   22篇
  1991年   11篇
  1990年   8篇
  1989年   16篇
  1988年   12篇
  1987年   18篇
  1986年   15篇
  1985年   3篇
  1984年   4篇
  1983年   5篇
  1982年   2篇
  1978年   2篇
  1977年   4篇
  1976年   7篇
  1975年   4篇
  1974年   3篇
  1973年   2篇
  1962年   2篇
排序方式: 共有2867条查询结果,搜索用时 0 毫秒
51.
本文分别对纺锤体抑制法、阴止凝缩法,同步拦截法三种方法,用于高分辨染色体的制备进行了探索,结果:选择第三种方法,即过量胸苷同步结合放线菌素D掺入法制备高分辨染色体,进行改进,获得比较理想的人类高分辨染色体,经临床应用77例,成功率为83.12%,分裂指数为4.68%。高分辨染色体占54.00%。  相似文献   
52.
The glenohumeral joint is inherently unstable because the large humeral head articulates with the small shadow glenoid fossa. Traumatic anterior dislocation of the shoulder is a relatively common athletic injury, and the high frequency of recurrent instability in young athletes after shoulder dislocation is discouraging to both the patient and the treating physician. Management of primary traumatic shoulder dislocation remains controversial. Traditionally, treatment involves initial immobilisation for 4–6 weeks, followed by functional rehabilitation. However, in view of the high recurrence rates associated with this traditional approach, there has been an escalating interest in determining whether immediate surgical intervention can lower the rate of recurrent shoulder dislocation, improving the patient’s quality of life. This review article aims to provide an overview of the nature and pathogenesis of first-time primary anterior shoulder dislocations, the widely accepted management modalities, and the efficacy of primary surgical intervention in first-time primary anterior shoulder dislocations.  相似文献   
53.
目的 分析成都市成年男性吸烟者吸烟行为、吸烟量及其变化的影响因素。方法对成都市两城区320名成年男性吸烟者面对面问卷调查。采用描述性分析、t检验、χ2检验、单因素方差分析、Kruskal-Wails H秩和检验、累积比数logistic回归方法分析数据。结果 分析显示吸烟者更换卷烟后, 吸烟量增加(t=2.327, P=0.021), 焦油量降低(t=-11.251, P<0.001);累积比数logistic回归分析显示, 学历较低(OR=1.968, P=0.040)、收入较高(OR=2.053, P=0.043)、烟蒂较短(OR=2.366, P=0.010)、尼古丁高依赖(OR=7.143, P<0.001)者吸烟量更大。结论 更换卷烟的吸烟者更倾向选择低焦油卷烟;学历低、收入高、尼古丁高依赖的吸烟者是控烟健康教育、行为干预的重点人群。  相似文献   
54.
55.
This study shows that Cd induces autophagy in the human's embryonic normal liver cell line (WRL‐68). The expression of LC3B‐II and the mature cathepsin L were analyzed by Western blotting. The autophagosomes and lysosomes were directly visualized by electron microscopy and confocal microscopy analysis in Cd‐exposed WRL‐68 cells. In this study, we first found that autophagy induced the activation of lysosomal function in WRL‐68 cells. The lysosomal activation was markedly decreased when the cells were co‐treated with 3‐MA (an inhibitor of autophagy). Secondly, we provided the evidence that the activation of lysosomal function depended on autophagosome–lysosome fusion. The colocalization of lysosome‐associated membrane protein‐2 (LAMP2) and GFP‐LC3 was significantly reduced, when they were treated with thapsigargin (an inhibitor of autophagosome–lysosome fusion). We demonstrated that deletion or blockage of the autophagosome–lysosome fusion process effectively diminished lysosomal activation, which suggests that lysosomal activation occurring in the course of autophagy is dependent on autophagosome–lysosome fusion. Thirdly, we provided evidence that the activation of lysosomal function was associated with lysosomal acid. We investigated the relationship between autophagosome–lysosome fusion and pH in acidic compartments by visualizing fusion process in WRL‐68 cells. This suggests that increasing pH in acidic compartments in WRL‐68 cells inhibits the autophagosome–lysosome fusion. Finally, we found that the activation of lysosomal function was associated with Ca2+ stores and the intracellular Ca2+ channels or pumps were possibly pH‐dependent. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
56.
Tang  Yundi  Sun  Xiaotong  Wang  Yuxuan  Luan  Huijie  Zhang  Ruijun  Hu  Fanlei  Sun  Xiaolin  Li  Xia  Guo  Jianping 《Clinical rheumatology》2021,40(7):2707-2715
Clinical Rheumatology - Interleukin (IL)-24 has been considered as an inflammatory cytokine in autoimmune diseases. However, conflicting data exist and its biological function remains...  相似文献   
57.
原发性免疫性血小板减少症(Primary immune thrombocytopenia,ITP)原称特发性血小板减少性紫癜(Idiopathic thrombocytopenic purpura,ITP),是一种自身免疫性疾病,是由于机体免疫系统功能紊乱引起血小板破坏增多致其数目减少引起的出血性疾病,临床表现为皮肤黏膜瘀点、瘀斑,尿血,严重者可引起内脏和颅内出血危及生命,骨髓象表现为巨核细胞发育、成熟障碍。儿童急性ITP大多预后良好,75%~82%急性ITP 6个月内可获得缓解,持续6个月以上的ITP中超过1/4在  相似文献   
58.
OBJECTIVE: To investigate whether genetic variation at the UCP3 locus contributes to human obesity. SUBJECTS: Ninety-one obese children (BMI>4 standard deviations from age related mean) and 419 Caucasian adults from the Isle of Ely Study. DESIGN: Single strand conformation polymorphism (SSCP) analysis was used to scan the coding region of the UCP3 gene in 91 severely obese children. A common polymorphism identified in this gene (c-55t) has been shown to associate with lower UCP3 mRNA expression. Polymerase chain reaction-based forced restriction digestion was used to detect this allele in Caucasian adults. Multiple regression analysis was used to determine associations between the c-55t genotype and anthropometric, energetic and biochemical indices relevant to obesity. MEASUREMENTS: For the obese children, SSCP analysis and sequencing of variants were carried out. For the Isle of Ely Study, c-55t genotype and anthropometric (body mass index, waist-hip ratio, percentage body fat), energetic (dietary fat intake, physical activity index, adjusted metabolic rate, maximum oxygen consumption) and biochemical indices (pre- and post-glucose challenge plasma triglycerides, non-esterified fatty acids, insulin and glucose) were determined. RESULTS: A previously reported missense mutation (V102I) was detected in a single obese Afro-Carribean child. Twenty-one percent of the genes examined in the Isle of Ely study carried the c-55t promoter variant. Age-adjusted body mass index (BMI) was significantly (P=0.0037) lower in carriers of this variant. CONCLUSION: Mutations in the coding sequence of UCP3 are unlikely to be a common monogenic cause of severe human obesity. In a Caucasian population the UCP3 c-55t polymorphism is negatively associated with BMI.  相似文献   
59.
60.
Post-traumatic stress disorder (PTSD) is characterized by avoidance, emotional numbing, increased arousal and hypervigilance for threat following a trauma. Thirty-three veterans (19 with PTSD, 14 without PTSD) who had experienced combat trauma while on deployment in Iraq and/or Afghanistan completed an emotional faces matching task while electroencephalography was recorded. Vertex positive potentials (VPPs) elicited by happy, angry and fearful faces were smaller in veterans with versus without PTSD. In addition, veterans with PTSD exhibited smaller late positive potentials (LPPs) to angry faces and greater intrusive symptoms predicted smaller LPPs to fearful faces in the PTSD group. Veterans with PTSD were also less accurate at identifying angry faces, and accuracy decreased in the PTSD group as hyperarousal symptoms increased. These findings show reduced early processing of emotional faces, irrespective of valence, and blunted prolonged processing of social signals of threat in conjunction with impaired perception for angry faces in PTSD.  相似文献   
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