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   150314篇
  免费   10041篇
  国内免费   2270篇
耳鼻咽喉   2263篇
儿科学   2266篇
妇产科学   2147篇
基础医学   22649篇
口腔科学   3476篇
临床医学   14996篇
内科学   25523篇
皮肤病学   4492篇
神经病学   11314篇
特种医学   8002篇
外国民族医学   16篇
外科学   18220篇
综合类   5089篇
现状与发展   7篇
一般理论   32篇
预防医学   8991篇
眼科学   3893篇
药学   14326篇
  48篇
中国医学   3070篇
肿瘤学   11805篇
  2023年   1226篇
  2022年   3882篇
  2021年   5908篇
  2020年   3258篇
  2019年   3776篇
  2018年   4574篇
  2017年   3968篇
  2016年   4699篇
  2015年   6747篇
  2014年   8052篇
  2013年   9085篇
  2012年   13654篇
  2011年   13189篇
  2010年   7736篇
  2009年   6613篇
  2008年   8961篇
  2007年   8373篇
  2006年   7424篇
  2005年   6838篇
  2004年   5751篇
  2003年   4995篇
  2002年   4235篇
  2001年   3275篇
  2000年   3024篇
  1999年   2366篇
  1998年   1020篇
  1997年   787篇
  1996年   582篇
  1995年   544篇
  1994年   446篇
  1993年   377篇
  1992年   829篇
  1991年   764篇
  1990年   687篇
  1989年   594篇
  1988年   495篇
  1987年   499篇
  1986年   348篇
  1985年   391篇
  1984年   268篇
  1983年   203篇
  1982年   140篇
  1981年   174篇
  1980年   132篇
  1979年   234篇
  1978年   168篇
  1976年   138篇
  1975年   125篇
  1974年   146篇
  1973年   125篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
21.
22.
Synovial chondromatosis is a rare lesion in the wrist, but some cases in the distal radioulnar joint have been reported and previous case reports emphasize joint calcifications, shown on preoperative plain radiographs. We report an extremely uncommon case of synovial chondromatosis in the pisotriquetral joint, in which radiographs and magnetic resonance imaging did not demonstrate apparent calcified bodies. In our case, for the accurate diagnosis and treatment, surgical exploration of the joint and synovectomy with removal of loose bodies was performed.  相似文献   
23.
24.
In the 6th Basic Plan for Long-Term Electricity Supply and Demand (6th BPE) for Korea, for the first time, the environmental costs of air pollution caused by oxides of sulfur (SOx), oxides of nitrogen (NOx), and particulate matters (PM) from power plants were estimated and included. However, several deficiencies in evaluating the environmental costs were found. In this study, (1) the validity of the environmental costs used in the 6th BPE was assessed, (2) a systematic approach was suggested and used to improve the environmental costs estimation, and (3) the sensitivity of the cost of generating electricity to the environmental costs by fuel type with the proposed approach was discussed. We found that the applied environmental costs used in the 6th BPE did not fully include the demographic characteristics of Korea. By applying more realistic parameter values, it was found that the newly estimated environmental cost was about 23 times higher than the cost estimated in the original 6th BPE for coal-fired power plants and about 1.5 times higher for liquefied natural gas (LNG)-fired power plants, suggesting that LNG-fired power plants are more economical if using more realistic environmental costs. Thus, it is critical to check the validity of parameter values when calculating environmental costs.  相似文献   
25.
A 17‐year‐old boy presented with recurring severe dermatitis of the face of 5‐months duration that resembled impetigo. He had been treated with several courses of antibiotics without improvement. Biopsy showed changes consistent with allergic contact dermatitis and patch testing later revealed sensitization to benzoyl peroxide, which the patient had been using for the treatment of acne vulgaris.  相似文献   
26.
27.
28.
29.
Mitochondria are known primarily as the location of the electron transport chain and energy production in cells. More recently, mitochondria have been shown to be signaling centers for apoptosis and inflammation. Reactive oxygen species (ROS) generated as by-products of the electron transport chain within mitochondria significantly impact cellular signaling pathways. Because of the toxic nature of ROS, mitochondria possess an antioxidant enzyme, superoxide dismutase 2 (SOD2), to neutralize ROS. If mitochondrial antioxidant enzymes are overwhelmed during severe infections, mitochondrial dysfunction can occur and lead to multiorgan failure or death. Pseudomonas aeruginosa is an opportunistic pathogen that can infect immunocompromised patients. Infochemicals and exotoxins associated with P. aeruginosa are capable of causing mitochondrial dysfunction. In this work, we describe the roles of SOD2 and mitochondrial ROS regulation in the zebrafish innate immune response to P. aeruginosa infection. sod2 is upregulated in mammalian macrophages and neutrophils in response to lipopolysaccharide in vitro, and sod2 knockdown in zebrafish results in an increased bacterial burden. Further investigation revealed that phagocyte numbers are compromised in Sod2-deficient zebrafish. Addition of the mitochondrion-targeted ROS-scavenging chemical MitoTEMPO rescues neutrophil numbers and reduces the bacterial burden in Sod2-deficient zebrafish. Our work highlights the importance of mitochondrial ROS regulation by SOD2 in the context of innate immunity and supports the use of mitochondrion-targeted ROS scavengers as potential adjuvant therapies during severe infections.  相似文献   
30.
目的 分析新型冠状病毒肺炎(以下简称新冠肺炎)疫情对天津市无偿献血的影响.方法 回顾性分析该市2020年无偿献血人次及献血量,并与2019年献血情况进行对比;分析2020年春节前后及2019年同期的献血情况.结果 2020年捐献全血和单采血小板的总人次较2019年均下降13.03%,献血量分别下降17.60%、10.37%.2020年与2019年春节期间捐献全血和单采血小板的人次和献血量均明显下降,但2020年献血情况持续受疫情影响.2020年1-6月全血和单采血小板的献血情况较2019年同期下降较为明显,2020年7-12月的献血情况好转,与2019年同期差距减小.结论 新冠肺炎疫情对无偿献血工作提出严峻考验.常态化疫情防控期间,分析研判疫情对无偿献血工作的影响,有利于制订更有效的预防措施抗击疫情,保障临床用血.  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