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   2985篇
  免费   152篇
  国内免费   8篇
耳鼻咽喉   101篇
儿科学   195篇
妇产科学   39篇
基础医学   348篇
口腔科学   72篇
临床医学   240篇
内科学   716篇
皮肤病学   85篇
神经病学   131篇
特种医学   122篇
外科学   282篇
综合类   59篇
一般理论   1篇
预防医学   235篇
眼科学   177篇
药学   203篇
中国医学   12篇
肿瘤学   127篇
  2021年   42篇
  2020年   43篇
  2019年   52篇
  2018年   72篇
  2017年   38篇
  2016年   55篇
  2015年   57篇
  2014年   82篇
  2013年   105篇
  2012年   186篇
  2011年   161篇
  2010年   96篇
  2009年   80篇
  2008年   154篇
  2007年   159篇
  2006年   157篇
  2005年   120篇
  2004年   116篇
  2003年   110篇
  2002年   97篇
  2001年   65篇
  2000年   60篇
  1999年   61篇
  1998年   30篇
  1997年   28篇
  1996年   27篇
  1995年   17篇
  1992年   45篇
  1991年   52篇
  1990年   36篇
  1989年   37篇
  1988年   48篇
  1987年   36篇
  1986年   35篇
  1985年   50篇
  1984年   43篇
  1983年   30篇
  1982年   23篇
  1980年   21篇
  1979年   31篇
  1978年   16篇
  1977年   18篇
  1976年   16篇
  1974年   24篇
  1973年   22篇
  1972年   17篇
  1971年   24篇
  1970年   19篇
  1967年   16篇
  1966年   16篇
排序方式: 共有3145条查询结果,搜索用时 15 毫秒
11.
12.
Indian Journal of Pediatrics - Congenital hyperinsulinism (CHI) is a clinically and genetically heterogeneous disorder, characterized by dysregulated insulin secretion. Pathogenic variants in at...  相似文献   
13.
14.
Otospongiosis-like lesions were induced in rats by immunizing them with type II collagen. After seven months' immunization, the rats were killed and processed for histologic study. We found otospongiotic lesions in the bony cochlea, vestibule, semicircular canal, and in the regions near the oval window and round window. The spongiotic lesions in the otic capsules were similar to human otospongiosis and were characterized by the following types of microscopic appearances. 1) The classic type showed enlarged vascular spaces with congestion, macrophages, fibroblasts, and sometimes osteoclasts. 2) The fibrotic type showed vascular spaces filled with fibrous tissues. 3) The osteoporotic type had a porous appearance and was devoid of content. 4) The sclerotic type showed bone spaces partially or entirely being replaced by new bone with blue mantles and a mosaic appearance. Some spongiotic lesions showed a mixture of the above types. The findings suggest that this animal model may provide important information to help understand the process of human otosclerosis.  相似文献   
15.
16.
17.
18.
Nonmotor symptoms (NMS) of Parkinson's disease (PD) are not well recognized in clinical practice, either in primary or in secondary care, and are frequently missed during routine consultations. There is no single instrument (questionnaire or scale) that enables a comprehensive assessment of the range of NMS in PD both for the identification of problems and for the measurement of outcome. Against this background, a multidisciplinary group of experts, including patient group representatives, has developed an NMS screening questionnaire comprising 30 items. This instrument does not provide an overall score of disability and is not a graded or rating instrument. Instead, it is a screening tool designed to draw attention to the presence of NMS and initiate further investigation. In this article, we present the results from an international pilot study assessing feasibility, validity, and acceptability of a nonmotor questionnaire (NMSQuest). Data from 123 PD patients and 96 controls were analyzed. NMS were highly significantly more prevalent in PD compared to controls (PD NMS, median = 9.0, mean = 9.5 vs. control NMS, median = 5.5, mean = 4.0; Mann-Whitney, Kruskal-Wallis, and t test, P < 0.0001), with PD patients reporting at least 10 different NMS on average per patient. In PD, NMS were highly significantly more prevalent across all disease stages and the number of symptoms correlated significantly with advancing disease and duration of disease. Furthermore, frequently, problems such as diplopia, dribbling, apathy, blues, taste and smell problems were never previously disclosed to the health professionals.  相似文献   
19.
BACKGROUND: Complicated intra-abdominal infections are a common problem in surgical practice. This study compared the effectiveness of ertapenem (1 g qd) and piperacillin/tazobactam (3.375 g q6h) in the treatment of these infections. METHODS: This was a multicenter, double-blinded, randomized study conducted in patients with complicated intra-abdominal infections. Of the 535 patients screened, 500 were stratified on the basis of disease severity (Acute Physiology and Chronic Health Evaluation [APACHE] II score < or =10 or >10), then randomized (1:1) to 4-14 days of treatment with one of the regimens and six weeks of followup. Nearly all patients (N = 494) were treated. The primary endpoint was the proportion of microbiologically evaluable patients with a favorable clinical response (cure) at two weeks. Non-inferiority of ertapenem was based on a difference in response rate of <15 percentage points compared with piperacillin/tazobactam (lower bound of the 95% CI > -15). RESULTS: Of the 494 treated patients, 231 were microbiologically evaluable, with 123 and 108 patients in the ertapenem and piperacillin/tazobactam groups, respectively. Statistically similar cure rates were observed in the ertapenem (82.1%) and piperacillin/tazobactam (81.7%) groups (difference 0.3 [95% CI: -9.6, 10.5]). The pathogens isolated most frequently were Escherichia coli, Bacteroides fragilis, and Bacteroides thetaiotamicron, typical isolates associated with intra-abdominal infections. There were no statistical differences between the groups in serious drug-related clinical adverse events, drug-related clinical adverse experiences leading to study discontinuation, or mortality. CONCLUSIONS: Ertapenem was non-inferior to piperacillin/tazobactam in the cure of intra-abdominal infections caused by susceptible pathogens. Both study drugs generally were well tolerated.  相似文献   
20.
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality. Although the main risk factor is smoking, 15-19% of COPD even in smokers has been attributed to occupational exposures. The aim of this study was to investigate the association between occupational exposure and risk of COPD. METHODS: Participants were part of a cross sectional study of risk factors for COPD. A total of 1232 completed a detailed respiratory questionnaire, spirometric testing and measurement of gas transfer. Job histories were coded according to the International Standard Classification of Occupations. These codes were then used to establish occupational exposures using the ALOHA job exposure matrix. RESULTS: The prevalence of emphysema was 2.4%, chronic obstructive bronchitis 1.8%, and COPD 3.4%. Subjects ever exposed to biological dusts had an increased risk of chronic obstructive bronchitis (OR 3.19; 95% CI 1.27 to 7.97), emphysema (OR 3.18; 95% CI 1.41 to 7.13), and COPD (OR 2.70, 95% CI 1.39 to 5.23). These risks were higher in women than in men. For biological dust, the risk of emphysema and COPD was also significantly increased in both the duration of exposure categories, again in women but not in men. No significant increased risks for COPD were found for mineral dust (OR 1.13; 95% CI 0.57 to 2.27) or gases/fumes (OR 1.63; 95% CI 0.83 to 3.22). CONCLUSION: In this general population sample of adults, occupational exposures to biological dusts were associated with an increased risk of COPD which was higher in women. Preventive strategies should be aimed at reducing exposure to these agents in the workplace.  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