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   81371篇
  免费   5829篇
  国内免费   212篇
耳鼻咽喉   610篇
儿科学   2406篇
妇产科学   1322篇
基础医学   11307篇
口腔科学   1837篇
临床医学   8609篇
内科学   16787篇
皮肤病学   1194篇
神经病学   7561篇
特种医学   2599篇
外国民族医学   1篇
外科学   11366篇
综合类   1105篇
一般理论   76篇
预防医学   7348篇
眼科学   1927篇
药学   5524篇
  1篇
中国医学   94篇
肿瘤学   5738篇
  2023年   402篇
  2022年   576篇
  2021年   1520篇
  2020年   921篇
  2019年   1478篇
  2018年   1802篇
  2017年   1357篇
  2016年   1479篇
  2015年   1725篇
  2014年   2545篇
  2013年   3567篇
  2012年   5631篇
  2011年   5803篇
  2010年   3256篇
  2009年   2891篇
  2008年   5236篇
  2007年   5767篇
  2006年   5627篇
  2005年   5354篇
  2004年   5160篇
  2003年   4668篇
  2002年   4542篇
  2001年   863篇
  2000年   730篇
  1999年   917篇
  1998年   1019篇
  1997年   864篇
  1996年   727篇
  1995年   700篇
  1994年   571篇
  1993年   561篇
  1992年   618篇
  1991年   549篇
  1990年   466篇
  1989年   467篇
  1988年   425篇
  1987年   406篇
  1986年   416篇
  1985年   449篇
  1984年   439篇
  1983年   451篇
  1982年   481篇
  1981年   454篇
  1980年   429篇
  1979年   329篇
  1978年   328篇
  1977年   281篇
  1976年   227篇
  1975年   183篇
  1974年   192篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
OBJECTIVE: To assess the utility and reliability of echocardiographic assessment of hemidiaphragm motion abnormalities in pediatric cardiothoracic patients. DESIGN: Retrospective observational study, with post hoc blinded assessment of echocardiographic and fluoroscopic results. SETTING: Tertiary care center. PATIENTS: Thirty-six consecutive pediatric cardiothoracic patients with suspected hemidiaphragm paralysis were identified and included in the study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The results of both echocardiographic and fluoroscopic studies on all patients were included. In addition, blinded review of study results were performed. The sensitivity and specificity of fluoroscopy in identifying hemidiaphragms that needed plication were 100% and 74%, respectively. The positive predictive value was 55%; negative predictive value was 100%. Comparing reported diagnoses with blinded review of the studies showed poor agreement; reviewers agreed with 89% diagnosed as normal, 44% of paralyzed, and 76% of paradoxical hemidiaphragms. The sensitivity and specificity of echo in identifying hemidiaphragms that needed plication were 100% and 81%, respectively. The positive predictive value and negative predictive value were 66% and 100%. Comparing reported diagnoses with blinded review, reviewers agreed with 97% diagnosed as normal, 81% of paralyzed, and 100% of paradoxical hemidiaphragms. Echocardiography was less accurate in discriminating between paralyzed and paradoxical diaphragm motion. Echocardiography was specific for paradoxical motion, since both patients identified by echocardiography were confirmed by fluoroscopy, but it was not sensitive. In nine patients, echo showed paralyzed motion that was identified by fluoroscopy as paradoxical. CONCLUSIONS: This study supports the use of echocardiography in the assessment of diaphragm function. When the diaphragms are clearly visualized by echo, as they are in the majority of cases, the addition of an additional fluoroscopic study adds no clinical value. The differentiation between paralyzed and paradoxical motion is unreliable by both imaging modalities.  相似文献   
83.

Background  

Streptococcus (S.) pneumoniae meningitis has a high lethality despite antibiotic treatment. Inflammation is a major pathogenetic factor, which is unresponsive to antibiotics. Therefore adjunctive therapies with antiinflammatory compounds have been developed. TNF484 is a TNF-alpha converting enzyme (TACE) inhibitor and has been found efficacious in experimental meningitis. Toll-like receptor 2 (TLR2) contributes to host response in pneumococcal meningitis by enhancing bacterial clearing and downmodulating inflammation. In this study, TNF484 was applied in mice, which lacked TLR2 and exhibited a strong meningeal inflammation.  相似文献   
84.
This study evaluated the effectiveness of early orthodontic treatment with the Twin-block appliance for the developing Class II Division 1 malocclusion. This multicenter trial was carried out in the United Kingdom. A total of 174 children, aged 8 to 10 years old, with Class II Division 1 malocclusion were randomly allocated to receive treatment with a Twin-block appliance or to an untreated, control group. Data were collected at the start of the study and 15 months later. Results showed that early treatment with Twin-block appliances resulted in reduction of overjet, correction of molar relationships, and reduction in severity of malocclusion. Most of this correction was due to dentoalveolar change, but some was due to favorable skeletal change. Early treatment with the Twin-block appliance is effective in reducing overjet and severity of malocclusion. The small change in the skeletal relationship might not be considered clinically significant.  相似文献   
85.
86.
87.
An estimated 38.6 million persons globally are living with HIV, of whom over 1.1 million reside in Zambia. Of the 2 million cases in the US, 64% of new cases among women are among African Americans. Alcohol and drug use represents a significant risk factor for HIV transmission among both Zambians and African Americans. In addition, gender dynamics in both the US and Zambia promote transmission. This study examines two interventions targeting HIV risk behavior among HIV positive substance users, women in Miami, USA (the New Opportunities for Women (NOW) Project) and men in Lusaka, Zambia (the Partner Project). The study compares the efficacy of these two culturally tailored sexual behavior interventions provided in group and individual session formats. US and Zambian participants increased sexual barrier use and reduced substance-related sexual risk. Comparatively greater gains were made by higher risk Zambian males than US females in both group and individual conditions. Among lower risk participants, women in the group condition achieved and sustained the greatest comparative risk reductions. Results suggest that cost effective group HIV transmission risk reduction interventions for multiethnic individuals can be successfully implemented among both female and male drug and alcohol users in multinational settings.  相似文献   
88.

Background  

The aim of the current study is to investigate the relationship between physical anhedonia and psychopathological parameters, pharmacological parameters or motor side-effects in a sample of inpatients with schizophrenia in an acute episode of their illness.  相似文献   
89.
90.
Ziprasidone is an atypical antipsychotic with a unique receptor-binding profile. Currently, ziprasidone is approved by the US Food and Drug Administration for the acute treatment of psychosis in schizophrenia and mania in bipolar disorder. When compared to certain other atypical antipsychotics, ziprasidone appears to have a relatively benign side effect profile, especially as regards metabolic effects eg, weight gain, serum lipid elevations and glucose dysregulation. Taken together, these data suggest that ziprasidone may be a first line treatment for patients with bipolar mania. However, ziprasidone is a relatively new medication for which adverse events after long-term use and/or in vulnerable patient populations must be studied. Unstudied areas of particular importance include the efficacy and safety of ziprasidone in the treatment of bipolar depression and relapse prevention of mania as, well as in the subpopulations of pregnant women, the elderly and pediatric patients. The emergence of mania in patients taking ziprasidone is another topic for further study.  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