首页 | 官方网站   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   47456篇
  免费   3699篇
  国内免费   2189篇
医药卫生   53344篇
  2024年   64篇
  2023年   561篇
  2022年   991篇
  2021年   2341篇
  2020年   1418篇
  2019年   1447篇
  2018年   1612篇
  2017年   1289篇
  2016年   1526篇
  2015年   2174篇
  2014年   2671篇
  2013年   2694篇
  2012年   3919篇
  2011年   4118篇
  2010年   2410篇
  2009年   2064篇
  2008年   2785篇
  2007年   2642篇
  2006年   2420篇
  2005年   2347篇
  2004年   1727篇
  2003年   1543篇
  2002年   1312篇
  2001年   1038篇
  2000年   1118篇
  1999年   1013篇
  1998年   529篇
  1997年   461篇
  1996年   371篇
  1995年   364篇
  1994年   280篇
  1993年   206篇
  1992年   290篇
  1991年   255篇
  1990年   219篇
  1989年   182篇
  1988年   149篇
  1987年   148篇
  1986年   122篇
  1985年   99篇
  1984年   59篇
  1983年   51篇
  1982年   35篇
  1981年   27篇
  1980年   27篇
  1979年   38篇
  1978年   21篇
  1977年   18篇
  1974年   18篇
  1973年   15篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
101.
102.
山东省医学影像研究所所长连世海副研究员是解放后我国自己培养的一代科学家之一,1945年参加革命,1953年毕业于山东医学院,1958年任山东省立医院放射科主任,副主任医师。  相似文献   
103.
本文将聚乙二醇(PEG)比浊法和固相酶联免疫法(ELISA)结合,建立了—较灵敏的免疫复合物(IC)直接固相吸附抗原特异性检测法。利用牛清蛋白(BSA)为已知抗原组份的IC模型,分别对IC直接固相吸附的条件和影响因素、方法的灵敏度、重复性等进行了研究。结果发现IC在解离状态下直接固相吸附后的抗原特异性检测灵敏度明显高于未解离者。该法具有简单易行,灵敏度较高、适于临床测定大量血清样品等优点。  相似文献   
104.
105.
目的调查门诊患者中焦虑症的患病率以及共病抑郁症状的发生率。方法在我院精神科门诊、心理咨询门诊以及社区卫生服务中心内科门诊就诊的1106例患者作为研究对象,并做SAS、SDS、HAMA量表评定。结果1106例患者中,符合焦虑症诊断,且HAMA≥14分者共93例,患病率为8.41%。SDS标准分≥50共病抑郁症状的共43例,占46.23%。HAMA分值、SAS分值与SDS分值有显著性正相关。结论门诊中罹患焦虑症的患者焦虑程度越高,共病抑郁的可能性就越大。  相似文献   
106.
Osteogenesis is synergistically enhanced by the combined effect of complimentary factors. This study showed that Nell-1 and BMP-2 synergistically enhanced osteogenic differentiation of myoblasts and phosphorylated the JNK MAPK pathway. The findings are important because of the osteochondral specificity of Nell-1 signaling and the potential therapeutic effects of coordinated BMP-2 and Nell-1 delivery. INTRODUCTION: BMPs play an important role in the migration and proliferation of mesenchymal cells and have a unique ability to alter the differentiation of mesenchymal cells toward chondrogenic and osteogenic lineages. Signaling upstream of Cbfa1/Runx2, BMPs effects are not limited to cells of the osteoblast lineage. Thus, additional osteoblast-specific factors that could synergize with BMP-2 would be advantageous for bone regeneration procedures. NELL-1 (NEL-like molecule-1; NEL [a protein strongly expressed in neural tissue encoding epidermal growth factor like domain]) is a novel growth factor believed to preferentially target cells committed to the osteochondral lineage. MATERIALS AND METHODS: C2C12 myoblasts were transduced with AdLacZ, AdNell-1, AdBMP-2, or AdNell-1+AdBMP-2 overexpression viruses. Effects were studied by cell morphology, alkaline phosphatase activity, osteopontin production, and MAPK signaling. Additionally, in a nude mouse model, viruses were injected into leg muscles, and new bone formation was examined after 2 and 8 wk. RESULTS: C2C12 myoblasts co-transduced with AdNell-1+AdBMP-2 showed a synergistic effect on osteogenic differentiation as detected by alkaline phosphatase activity and osteopontin production. Nell-1 stimulation on AdNell-1 + AdBMP-2 preconditioned C2C12 cells revealed significant activation of the non-BMP-2 associated c-Jun N-terminal kinase (JNK) MAPK signaling pathway, but not the p38 or extracellular signal-regulated kinase (ERK1/2) MAPK pathways. Importantly Nell-1 alone did not induce osteogenic differentiation of myoblasts. In a nude mouse model, injection of AdNell-1 alone stimulated no bone formation within muscle; however, injection of AdNell-1+AdBMP-2 stimulated a synergistic increase in bone formation compared with AdBMP-2 alone. CONCLUSIONS: These findings are important because of the confirmed osteochondral specificity of Nell-1 signaling and the potential therapeutic effects of enhanced BMP-2 action with coordinated Nell-1 delivery.  相似文献   
107.
With the introduction of more potent immunosuppressive agents, rejection has decreased in simultaneous pancreas/kidney transplant (SPK) recipients. However, as a consequence, opportunistic infections have increased. The purpose of this report is to outline the course of SPK patients who developed polyomavirus-associated nephropathy (PVAN). A retrospective review of 146 consecutive SPK recipients from January 1, 1996 to December 31, 2002 was performed. Immunosuppression, rejection and development of PVAN were reviewed. Nine patients were identified. All received induction with either OKT3 or thymoglobulin. Immunosuppression included tacrolimus/cyclosporine, MMF/azathioprine and sirolimus/prednisone. Two patients were treated for kidney rejection prior to the diagnosis of PVAN. Time to diagnosis was an average of 359.3 days post-transplantation. Immunosuppression was decreased but five ultimately lost function. However, none developed pancreatic abnormalities as demonstrated by normal glucose and amylase. Two underwent renal retransplantation after PVAN diagnosis and both have normal kidney function. PVAN was the leading cause of renal loss in SPK patients in the first 2 years after transplantation and is a serious concern for SPK recipients. The pancreas, however, is spared from evidence of infection, and no pancreatic rejection occurred when immunosuppression was decreased.  相似文献   
108.
The treatment of keloid and hypertrophic scars remains difficult. Enzymatic digestion of keloid scars has been previously proposed as an effective treatment strategy for reducing the volume of keloid scars. To test this, we administered intra-lesional injections of pure collagenase (between 600 and 4500 units for each scar) into the keloid and hypertrophic scars of seven human volunteers (five keloid and two hypertrophic scars). Five patients (three keloid and two hypertrophic) received more than one injection of collagenase. The treatment resulted in a temporary reduction in scar volume for three of the patients with keloid scars. However, scar volumes for these three patients returned to the same (or greater) levels after 6 months of follow-up. Treatment with collagenase produced no change in scar volume for the two patients with hypertrophic scar. Side effects were numerous and severe including; pain, swelling, blistering, ulceration and ecchymosis at the site of injection. One patient required admission to hospital for 48 h after the first injection. Maximum length of follow-up was 6 months. None of the seven patients completed the study and returned for final follow-up at 2 years. This pilot study suggests that treatment of keloid and hypertrophic scars with intra-lesional injections of collagenase is ineffective.  相似文献   
109.
搭建基础平台是改传统三年制医学教学“1+1+1”模式为“1+1”模式,为以“市场为导向,就业为中心”的高职教学进行多向培养提供条件,既拓宽教学渠道,适应市场需求,解决学生就业问题,同时又有利于学校发展,符合教学新模式量展要求。  相似文献   
110.
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-23

京公网安备 11010802026262号