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   5040篇
  免费   377篇
  国内免费   16篇
耳鼻咽喉   59篇
儿科学   157篇
妇产科学   86篇
基础医学   641篇
口腔科学   91篇
临床医学   713篇
内科学   866篇
皮肤病学   91篇
神经病学   533篇
特种医学   240篇
外科学   666篇
综合类   56篇
一般理论   13篇
预防医学   537篇
眼科学   91篇
药学   365篇
中国医学   8篇
肿瘤学   220篇
  2023年   37篇
  2022年   60篇
  2021年   129篇
  2020年   78篇
  2019年   137篇
  2018年   145篇
  2017年   97篇
  2016年   123篇
  2015年   153篇
  2014年   178篇
  2013年   228篇
  2012年   332篇
  2011年   363篇
  2010年   210篇
  2009年   161篇
  2008年   317篇
  2007年   285篇
  2006年   239篇
  2005年   285篇
  2004年   247篇
  2003年   206篇
  2002年   203篇
  2001年   82篇
  2000年   87篇
  1999年   57篇
  1998年   42篇
  1997年   31篇
  1996年   29篇
  1995年   26篇
  1993年   20篇
  1992年   34篇
  1991年   37篇
  1990年   48篇
  1989年   42篇
  1988年   46篇
  1987年   43篇
  1986年   41篇
  1985年   42篇
  1984年   37篇
  1983年   27篇
  1982年   19篇
  1981年   22篇
  1979年   28篇
  1978年   19篇
  1975年   24篇
  1974年   19篇
  1973年   26篇
  1971年   28篇
  1970年   22篇
  1968年   20篇
排序方式: 共有5433条查询结果,搜索用时 46 毫秒
21.
Talc from surgical gloves has been known to be a cause of granulomas within the surgical cavity. We report a case in which recurrent conjuntival inflammation was found to be caused by talc.  相似文献   
22.
Early Intervention for Trauma: Current Status and Future Directions   总被引:5,自引:0,他引:5  
Although psychological debriefing (PD) represents the most common form of early intervention for recently traumatized people, there is little evidence supporting its continued use with individuals who experience severe trauma. This review identifies the core issues in early intervention that need to be addressed in resolving the debate over PD. It critiques the available evidence for PD and the early provision of cognitive-behavioral therapy (CBT). Based on available evidence, we propose that psychological first aid is an appropriate initial intervention, but that it does not serve a therapeutic or preventive function. When feasible, initial screening is required so that preventive interventions can be used for those individuals who may have difficulty recovering on their own. Evidence-based CBT approaches are indicated for people who are at risk of developing posttraumatic psychopathology. Guidelines for managing acutely traumatized people are suggested and standards are proposed to direct future research that may advance our understanding of the role of early intervention in facilitating adaptation to trauma.  相似文献   
23.
To determine the utility of the lateral view of the chest in emergency department patients, records of all patients who had had 2-view chest x-rays ordered in the emergency department were reviewed retrospectively. A study radiologist recorded a reading of the posteroanterior (PA) radiograph alone. The lateral radiograph was then provided, along with the PA view, and a second reading was recorded. A comparison was then made between the first and second readings.A total of 417 sets of x-rays were included. The PA view alone successfully diagnosed or suspected 92% of pulmonary nodules, 95% of effusions, 97% of cases of emphysema, 98% of pneumonias, and 100% of cases of cardiomegaly, pulmonary edema, interstitial pulmonary disease, and atelectasis.In the emergency department patient population, lateral views of the chest have minimal diagnostic yield and therefore may be used selectively to safely decrease the amount of breast radiation exposure to young women.  相似文献   
24.
D-cycloserine augmented exposure therapy for obsessive-compulsive disorder.   总被引:1,自引:1,他引:0  
BACKGROUND: D-cycloserine (DCS), a glutamatergic partial N-methyl-d-aspartate (NMDA) agonist, can facilitate extinction learning related to cued fear in animals and humans. We predicted that DCS would accelerate obsession-related distress reduction in patients with obsessive-compulsive disorder (OCD) undergoing extinction-based exposure therapy. METHODS: We administered DCS (125 mg) or placebo in a double-blind fashion to individuals with OCD approximately 2 hours before each exposure session. RESULTS: D-cycloserine decreased both the number of exposure sessions required to achieve clinical milestones and the rate of therapy dropout. After four exposure sessions, patients in the DCS group reported significantly greater decreases in obsession-related distress compared with the placebo group; however, after additional sessions, the placebo group tended to catch up. CONCLUSIONS: D-cycloserine augmentation has the potential to increase the efficiency, palatability, and overall effectiveness of standard exposure therapy for OCD.  相似文献   
25.
26.
In search of genes possibly involved in the regulation of hindbrain segmentation, we have isolated mouse cDNA clones corresponding to putative protein kinase genes by polymerase chain reaction amplification of cDNA from 9.5-day-old embryo hindbrains. In situ hybridization analysis revealed that one of these genes, Sek, was expressed in an alternating segment-restricted pattern in the developing hindbrain. Isolation and analysis of Sek cDNAs covering the entire coding sequence indicated that Sek encoded a putative receptor protein tyrosine kinase, belonging to the Eph family. These data are consistent with a role of the Sek gene product in a signal transduction process involved in pattern formation in the hindbrain.  相似文献   
27.
28.
Lifetime job histories from a population-based, case-control study were analyzed to investigate the relationship between multiple myeloma and employment in various occupations and industries. Interviews were obtained from 89% (692) of eligible incident cases and 83% (1683) of eligible controls. An elevated risk was observed among persons ever employed as painters [odds ratio (OR) + 2.1, 95% confidence interval (CI) + 1.2–3.6], particularly for those employed for 10 or more years (OR + 4.1, 95% CI + 1.8–10.4). A small excess risk was observed among agricultural workers employed for 10 or more years (OR + 1.3, 95% CI + 1.0–2.2), with a higher relative risk observed among farm laborers (OR + 1.8, 95% CI + 1.0–4.0). Among agricultural workers who reported having been highly exposed to pesticides, the OR was 5.2 (95% CI + 1.6–21.1). Some evidence, based on smaller numbers, was also found to support an association with firefighting and employment in the petroleum- and coal-products manufacturing industries. Little evidence was found to support the previously noted association with wood exposure, and no evidence for an association with employment in the rubber or petroleum refining industries was found. This study lends further support to previously reported associations between multiple myeloma and employment among painters and agricultural workers. © 1993 Wiley-Liss, Inc.  相似文献   
29.
Chronic lymphocytic leukemia in relation to chemical exposures   总被引:8,自引:0,他引:8  
As part of a population-based case-control study carried out in four areas of the United States, 427 cases of chronic lymphocytic leukemia diagnosed between July 1, 1977, and December 31, 1981, and 1,683 controls were interviewed regarding their history of chemical exposure. Respondents were asked if they had ever been "highly exposed" at home, at work, or elsewhere to one or more of a list of chemicals or to any other such substances not on the list. These chemicals were categorized into 20 exposure groups based on chemical composition. Odds ratios were calculated adjusting for age, sex, race, education level, and geographic location by means of unconditional logistic regression. Increased risks were associated with reported past exposure to acid-containing chemicals, "other caustic substances," aliphatic hydrocarbons, and chlorinated hydrocarbons. Because of the large number of exposures investigated in this study, and because of the relatively imprecise means the authors had to assess exposure, further research is needed to verify these findings.  相似文献   
30.
The immunogenicity of recombinant protein or anti-viral DNA vaccines can be significantly improved by the addition of tandem copies of the complement fragment C3d. We sought to determine if the efficacy of a circumsporozoite protein (CSP)-based DNA vaccine delivered to mouse skin by gene gun was improved by using this strategy. Instead, we found that C3d suppressed the protective immunity against Plasmodium berghei malaria infection and deviated immunity, most notably by suppressing the induction of antibodies specific for the CSP C-terminal flanking sequence and by suppressing the induction of CSP-specific IL-4-producing spleen cells. We further showed that C3d bound to the C-terminal flanking sequence of the CSP, which may explain the immune deviation observed in CS/C3d chimeric antigen. We have thus identified C3d-mediated epitope masking and shifting of both the humoral and cellular immune responses as a potential novel escape mechanism, which plasmodia may use to divert the induction of protective immunity.  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