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   8924篇
  免费   555篇
  国内免费   59篇
耳鼻咽喉   53篇
儿科学   386篇
妇产科学   283篇
基础医学   1063篇
口腔科学   100篇
临床医学   1543篇
内科学   1545篇
皮肤病学   134篇
神经病学   673篇
特种医学   343篇
外科学   812篇
综合类   177篇
一般理论   9篇
预防医学   1145篇
眼科学   244篇
药学   441篇
  1篇
中国医学   28篇
肿瘤学   558篇
  2023年   45篇
  2022年   69篇
  2021年   183篇
  2020年   89篇
  2019年   179篇
  2018年   189篇
  2017年   169篇
  2016年   182篇
  2015年   180篇
  2014年   262篇
  2013年   435篇
  2012年   576篇
  2011年   623篇
  2010年   368篇
  2009年   314篇
  2008年   571篇
  2007年   598篇
  2006年   574篇
  2005年   552篇
  2004年   520篇
  2003年   496篇
  2002年   478篇
  2001年   125篇
  2000年   120篇
  1999年   115篇
  1998年   128篇
  1997年   144篇
  1996年   133篇
  1995年   106篇
  1994年   91篇
  1993年   99篇
  1992年   73篇
  1991年   55篇
  1990年   52篇
  1989年   70篇
  1988年   90篇
  1987年   50篇
  1986年   33篇
  1985年   56篇
  1984年   30篇
  1983年   24篇
  1982年   42篇
  1981年   28篇
  1980年   40篇
  1979年   22篇
  1978年   29篇
  1977年   22篇
  1976年   23篇
  1975年   22篇
  1966年   6篇
排序方式: 共有9538条查询结果,搜索用时 78 毫秒
101.
102.
Cognitive Impairment (CI) screening is recommended for those engaged in harmful levels of alcohol use. However, there is a lack of evidence on implementation. This paper explores the barriers and facilitators to CI screening experienced across a service specifically for older drinkers. The findings draw on data gathered as part of an evaluation of a multilevel programme to reduce alcohol-related harm in adults aged 50 and over in five demonstration areas across the United Kingdom. It is based on qualitative interviews and focus groups with 14 service providers and 22 service users. Findings are presented thematically under the section headings: acceptability of screening, interpretation and making sense of screening and treatment options. It is suggested that engagement with CI screening is most likely when its fit with agency culture and its purpose is clear; where service providers have the technical skills to administer and discuss the results of screening with service users; and where those undertaking screening have had the opportunity to reflect on their own experience of being screened. Engagement with CI screening is also most likely where specific intervention pathways and engagement practices can be accessed to respond to assessed need.  相似文献   
103.
Needle biopsy of renal allografts: comparison of two techniques   总被引:2,自引:0,他引:2  
Two techniques for renal allograft biopsy were retrospectively evaluated to compare relative safety and efficacy. After ultrasound (US) localization of the kidney and biopsy with a hand-held 14-gauge cutting needle, an adequate specimen was obtained in 74 of 77 cases (96%). Major complications occurred in six of these 77 cases (8%). One hundred four biopsies were performed by using a smaller 18-gauge cutting needle with a spring-loaded biopsy "gun" and real-time US guidance. With this newer technique, specimens adequate for diagnosis were obtained in 99 biopsies (95%). There was a single major complication with this technique (1%). The 18-gauge needle with real-time US guidance yields comparably adequate specimens with a lower frequency of complications.  相似文献   
104.
探讨肝纤维化形成过程转化生长因子-β及其受体的表达对胶原合成的影响。方法:采用免疫组化和斑点杂交技术,观察实验性大鼠肝纤维化过程肝内TGF-β1,TGF-βRⅡ和Ⅰ、Ⅲ型前胶原mRNA及其蛋白表达的动态变化。结果随着肝纤维化程度的加重,肝内TGF-β1、TGF-βRⅡ和Ⅰ、Ⅲ型前胶原mRNA及其蛋白表达均明显增加,组间比较均有显著差异(P〈0.05或P〈0.01)。TGF-β1与Ⅰ、Ⅲ型前胶原mR  相似文献   
105.
目的 :探讨小柴胡汤分解剂在体外及体内抗柯萨奇 B3病毒 (CVB3)及保护心肌细胞的作用。方法 :用小柴胡汤分解剂通过体外微量细胞培养 ,作用于被 CVB3直接损伤的细胞模型及经腹腔感染 CVB3m Balb/ c小鼠心肌炎模型 ,分析不同浓度分解剂的效应。结果 :在体外细胞上分解剂 A、B液自 1∶ 32稀释度对 vero细胞的毒性作用已丧失 ,至 1∶ 2 5 6稀释度时 ,仍能对抗 CVB3对细胞致病变作用。在体内分解剂 A、B液治疗组小鼠 35只 ,心肌炎发生率 37.14% ;而 2 0只对照组小鼠心肌炎发生率 5 9.1% ,两者有显著性差异 (χ2 =4.6 8,P <0 .0 5 ) ,在预防给药组更为明显 (P <0 .0 1)。结论 :小柴胡汤分解剂 A、B液在体内、体外均具有抗病毒及保护心肌的作用。  相似文献   
106.
Data from analgesic clinical trials have characteristics such as ordered categorical longitudinal responses with repeated measures, delay of effect with respect to analgesic plasma concentration, and right-hand censoring of response due to remedication. In order to determine the concentration-effect relationship of such data, we propose convolving an empirical function for plasma concentration, in the form of broken lines which connect each pair of neighboring observations, with a monoexponential function, to generate effect site concentration Effect site concentration and time are used, simultaneously, as independent variables in the fit of the model for the logit of the probability of having a specific pain relief (PR) score at each time point pre-remedication, via maximum likelihood. Using corresponding effect site concentration, the probabilities of having specific PR scores post-remedication are predicted via the concentration-response relationship established. The overall (pre- and post-remedication) predictions and corresponding standard errors for the responses are then estimated. Inference of the PR scoring, using a posterior method, is proposed. An illustration using real data is used to demonstrate these methods.  相似文献   
107.
Design and use of internal receiver coils for magnetic resonance imaging   总被引:2,自引:0,他引:2  
This review describes coils for MRI that are inserted into the body through natural orifices. It covers the design and implementation of small internal receiver coils for use in the pelvis and gastrointestinal tract. Normal anatomy delineated by the high resolution obtained by using these coils and the appearances in a number of disease states for each clinical application are described.  相似文献   
108.
Even at an early stage, hepatocellular carcinoma (HCC) in patients with cirrhosis is often deemed unresectable because of limited liver reserve. In these circumstances, liver transplantation (LTx) offers some hope for palliation or cure. The results of LTx for selected cirrhotic patients with HCC were analysed. The outcomes were compared with those of patients who underwent LTx for other forms of hepatic malignancy and those who underwent LTx for non-malignant conditions. Four hundred and eighty LTx were performed in 441 patients between January 1986 and December 1998. Twenty-eight LTx recipients (25 males, 3 females) of mean age 51 (14 63) yr had cirrhosis and HCC. Twenty-seven patients had underlying predisposing conditions (11 had hepatitis B, 10 had hepatitis C, 2 had hepatitis B and C, 1 had haemochromatosis, 1 had autoimmune hepatitis, 1 had alcoholic cirrhosis and 1 had alpha-1 antitrypsin deficiency). In 22 patients, HCC was diagnosed pre-LTx, and in 6 patients, the cancers were discovered incidentally. The average tumour size and number were 2.8 (0.4-11.5) cm and 1.3 (1-4), respectively. Two patients with known HCC died during and shortly after the LTx operation. Of the other patients, 3 died; 1 died of HCC recurrence 18 months post-LTx, 1 died of graft failure from recurrent hepatitis C and 1 died of fungal sepsis. Twenty-three (82%) patients survived to 22.5 (0.5-96) months post-LTx without HCC recurrence and with 1- and 3-yr actuarial patient survival rates of 87 and 76%, respectively. Equivalent survival rates of patients who underwent LTx for other malignancies (n = 11) were 82 and 46% (p = NS), and for those who underwent LTx for benign causes (n = 402), they were 77 and 73% (p = NS). All 15 patients with known HCC, who met the selection criteria now in use, survived. LTx can result in prolonged. cancer-free survival in a good proportion of patients with cirrhosis and HCC, particularly when the cancers are incidental, or when diagnosed pre-LTx, conforming to established selection criteria. An active LTx programme for this group of patients is justified.  相似文献   
109.
晚期肺癌73例外科治疗分析   总被引:1,自引:0,他引:1  
目的 总结近9a实施的肺癌手术203例,其中属于Ⅲb或Ⅳ期的晚期肺癌73例,旨在讨论晚期肺癌的手术指征,手术操作要点。方法 行全肺切除18例(左肺15例,右肺3例),肺叶切除54例,肺癌切除后复发余肺切除1例,经心包内处理肺血管17例,合并民房部分切除2例;支气管成形术13敢管隆凸成形术1例。结果 除1例因急性呼吸功能衰竭导致死亡外,其余均临床治愈,术后生存率1a内为95%,1a以不足2a为80%  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