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   12729篇
  免费   663篇
  国内免费   133篇
耳鼻咽喉   170篇
儿科学   251篇
妇产科学   197篇
基础医学   1737篇
口腔科学   1470篇
临床医学   1108篇
内科学   2488篇
皮肤病学   300篇
神经病学   891篇
特种医学   582篇
外科学   1124篇
综合类   67篇
一般理论   4篇
预防医学   1430篇
眼科学   196篇
药学   973篇
中国医学   129篇
肿瘤学   408篇
  2023年   116篇
  2022年   272篇
  2021年   439篇
  2020年   281篇
  2019年   405篇
  2018年   460篇
  2017年   320篇
  2016年   340篇
  2015年   406篇
  2014年   566篇
  2013年   679篇
  2012年   966篇
  2011年   985篇
  2010年   610篇
  2009年   458篇
  2008年   648篇
  2007年   695篇
  2006年   545篇
  2005年   510篇
  2004年   430篇
  2003年   357篇
  2002年   323篇
  2001年   251篇
  2000年   223篇
  1999年   183篇
  1998年   164篇
  1997年   137篇
  1996年   148篇
  1995年   115篇
  1994年   107篇
  1993年   103篇
  1992年   77篇
  1991年   121篇
  1990年   101篇
  1989年   108篇
  1988年   111篇
  1987年   92篇
  1986年   72篇
  1985年   79篇
  1984年   45篇
  1983年   44篇
  1982年   43篇
  1981年   44篇
  1980年   42篇
  1979年   31篇
  1978年   31篇
  1977年   31篇
  1976年   24篇
  1975年   26篇
  1974年   34篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
132.
ObjectiveThe objective of the study is to evaluate the effectiveness of nursing interventions (NIC) using nursing outcomes (NOC) and based on NANDA-I nursing diagnoses in patients with heart failure in home care.MethodIn this longitudinal study, 23 patients with heart failure were followed for 6 months, in four home visits. During the visits, nursing diagnoses were established, outcomes assessed, and interventions implemented.ResultsOf the 11 NIC interventions implemented, eight proved effective, that is, showed significant improvement between the first and the fourth visit, according to scores obtained for six outcomes: knowledge: treatment regimen, knowledge: medication, compliance behavior, symptom control, activity tolerance, and energy conservation.ConclusionNIC interventions health education, self-modification assistance, behavior modification, teaching: prescribed medication, teaching: disease process, nutritional counseling, telephone consultation, and energy conservation showed effective outcomes based on NOC scores, suggesting that the NANDA-I, NIC, and NOC linkage is useful in patients with heart failure in home care.  相似文献   
133.
134.
Leptospira interrogans serogroup Icterohaemorrhagiae is the major serogroup infecting humans worldwide, and rodents and dogs are the most significant transmission sources in urban environments. Knowledge of the prevalent serovars and their maintenance hosts is essential to understand the epidemiology of leptospirosis. In this study, 20 Leptospira isolates were evaluated by pulsed-field gel electrophoresis (PFGE), variable number tandem-repeat analysis (VNTR), serotyping, and determination of antimicrobial resistance profile. Isolates, originated from bovine, canine, human, and rodent sources, were characterized by microscopic agglutination test with polyclonal and monoclonal antibodies and were identified as L. interrogans serogroup Icterohaemorrhagiae serovar Copenhageni. MICs of antimicrobials often used in veterinary medicine were determined by broth microdilution test. Most of tested antibiotics were effective against isolates, including penicillin, ampicillin, and ceftiofur. Higher MIC variability was observed for fluoroquinolones and neomycin; all isolates were resistant to trimethoprim/sulfamethoxazole and sulphadimethoxine. Isolates were genotyped by PFGE and VNTR; both techniques were unable to discriminate between serovars Copenhageni and Icterohaemorrhagiae, as expected. PFGE clustered all isolates in 1 pulsotype, indicating that these serovars can be transmitted between species and that bovine, rodent, and dogs can maintain them in the environment endangering the human population.  相似文献   
135.
Background: Optimal methods of preparing students for high-stakes standardized patient (SP) examinations are unknown. Purposes: The purpose is to compare the impact of two formats of a formative SP examination (Web-based vs. in-person) on scores on a subsequent high-stakes SP examination and to compare students' satisfaction with each formative examination format. Methods: Clustered randomized trial comparing a Web-based module versus in-person formative SP examination. We compared scores on a subsequent high-stakes SP examination and satisfaction. Results: Scores on the subsequent high-stakes SP examination did not differ between the two formative formats but were higher after the formative assessment than without (p < .001). Satisfaction was higher with the in-person than Web-based formative assessment format (4.00 vs. 3.62 on a 5-point scale, p = .01). Conclusions: Two formats of a formative SP examination led to equivalent improvement in scores on a subsequent high-stakes examination. Students preferred an in-person formative examination to online but were satisfied with both.  相似文献   
136.
137.
138.
Widespread in the coastal zones of (sub)tropical regions, mangroves are an essential habitat for many animal species and provide subsistence resources for many human coastal communities. Among remote sensing techniques, synthetic aperture radar is a particularly advantageous method to monitor mangroves: images are not dependent on cloud cover and can provide information from forest understory. This article mapped mangrove forests in the southern coast of São Paulo State (Brazil) using frequency-based contextual classification of incoherent attributes derived from a multi-polarized Phased Array L-Band Synthetic Aperture Radar (PALSAR) image. The use of 10 incoherent attributes and only 3 Synthetic Aperture Radar (SAR) vegetation indices as input for digital classification showed the best accuracies with kappa index values of 0.739 and 0.734, respectively. HH polarization and SAR vegetation indices were the attributes that contributed most to the mangrove mapping procedure. The use of L-Band SAR data was effective for mapping mangrove areas, and therefore it is recommended as a tool for coastal management.  相似文献   
139.
van Schaik  JP; Hawkins  IF  Jr 《Radiology》1985,155(3):829-830
A new technique is described for reversing the direction of the catheter tip during translumbar aortography, without the need for partial withdrawal of the catheter from the aortic lumen. The method ensures optimal delivery of contrast medium at the desired level, while avoiding the risk of retroperitoneal bleeding or dislodgement during catheter manipulation.  相似文献   
140.
Objective: Describe the use of assistive technology to enhance communication opportunities for older adults.

Methods: A systematic review was conducted in two databases, PubMed and Web of Science, by using two different searches in each. The search was limited to original articles, in English language, including people aged 60 years and older that used any type of assistive technology for communication. The articles found in the initial search were filtered by title, abstracts and the remaining articles were fully read.

Results: Eighteen studies were included in this review after the reading of full-texts. Most of the studies included apparently healthy participants with communication limitations due to aging related changes and the others included people with some pathology that prevent them from normal communication.

Conclusion: Four categories of assistive technology were identified: assistive technology for people with speech problems; robot or videoconferencing systems; Information and Communication Technologies and, other types of assistive technology for communication, such as hearing aids and scrapbooks. Assistive technology for communication of older adults is not only used by people with disabilities that prevent them from usual communication. They are mostly for older adults without a pathological communication problem.  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