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   8242篇
  免费   625篇
  国内免费   26篇
耳鼻咽喉   23篇
儿科学   195篇
妇产科学   170篇
基础医学   1450篇
口腔科学   101篇
临床医学   850篇
内科学   1624篇
皮肤病学   230篇
神经病学   950篇
特种医学   220篇
外科学   645篇
综合类   36篇
一般理论   3篇
预防医学   707篇
眼科学   110篇
药学   763篇
中国医学   13篇
肿瘤学   803篇
  2023年   85篇
  2022年   141篇
  2021年   267篇
  2020年   143篇
  2019年   227篇
  2018年   244篇
  2017年   153篇
  2016年   221篇
  2015年   238篇
  2014年   328篇
  2013年   418篇
  2012年   683篇
  2011年   626篇
  2010年   358篇
  2009年   289篇
  2008年   536篇
  2007年   599篇
  2006年   511篇
  2005年   498篇
  2004年   492篇
  2003年   435篇
  2002年   383篇
  2001年   60篇
  2000年   42篇
  1999年   84篇
  1998年   89篇
  1997年   66篇
  1996年   57篇
  1995年   44篇
  1994年   31篇
  1993年   31篇
  1992年   31篇
  1991年   19篇
  1990年   30篇
  1989年   25篇
  1988年   23篇
  1987年   22篇
  1986年   11篇
  1985年   27篇
  1984年   16篇
  1983年   10篇
  1982年   22篇
  1981年   17篇
  1980年   11篇
  1979年   21篇
  1978年   14篇
  1977年   9篇
  1976年   12篇
  1970年   10篇
  1969年   11篇
排序方式: 共有8893条查询结果,搜索用时 15 毫秒
101.
International guidelines for the treatment of human immunodeficiency virus (HIV) infection change rapidly. They are mainly based on results from large-scale randomized clinical trials, but also on hypotheses. The objective of the study was to look at the use of antiretrovirals (ARVs) in different HIV treatment centres in Europe. Between August 1996 and September 1997 self-administered anonymous questionnaires were distributed to persons with HIV infection at inpatient and outpatient departments in 11 European countries; 1,366 people completed the questionnaire. Important differences in use of ARVs were noted between different centres. Zidovudine was the drug that was used predominantly in all countries and by 77% of all patients; the use of didanosine, zalcitabine and stavudine differed widely. Use of ARVs was found to be lower for people who reported intravenous drug use (compared to homosexual transmission), people with a low education level, and those with a monthly income lower than 992 Euro. The use of a protease inhibitor containing ARV treatment regimen was significantly lower in the centres in the south of Europe. Between 1996 and 1997, many persons with HIV infection in Europe received a suboptimal ARV treatment regimen. Use of ARVs should be improved for intravenous drug users, persons with lower educational level and lower income.  相似文献   
102.
103.
104.

Background

Little is known about what is at stake at a subjective level for the oncologists and the advanced cancer patients when they face the question whether to continue, limit or stop specific therapies. We studied (1) the frequency of such questioning, and (2) subjective determinants of the decision-making process from the physicians’ and the patients’ perspectives.

Methods

(1) All hospitalized patients were screened during 1 week in oncology and/or hematology units of five institutions. We included those with advanced cancer for whom a questioning about the pursuit, the limitation or the withholding of specific therapies (QST) was raised. (2) Qualitative design was based on in-depth interviews.

Results

In conventional units, 12.8 % of cancer patients (26 out of 202) were concerned by a QST during the study period. Interviews were conducted with all physicians and 21 advanced cancer patients. The timing of this questioning occurred most frequently as physicians estimated life expectancy between 15 days and 3 months. Faced with the most frequent dilemma (uncertain risk-benefit balance), physicians showed different ways of involving patients. The first two were called the “no choice” models: 1) trying to resolve the dilemma via a technical answer or a “wait-and-see” posture, instead of involving the patients in the questioning and the thinking; and 2), giving a “last minute” choice to the patients, leaving to them the responsibility of the decision. In a third model, they engaged early in shared reflections and dialogue about uncertainties and limits with patients, proxies and care teams. These schematic trends influenced patients’ attitudes towards uncertainty and limits, as they were influenced by these ones. Individual and systemic barriers to a shared questioning were pointed out by physicians and patients.

Conclusions

This study indicate to what extent these difficult decisions are related to physicians’ and patients’ respective and mutually influenced abilities to deal with and share about uncertainties and limits, throughout the disease trajectory. These insights may help physicians, patients and policy makers to enrich their understanding of underestimated and sensitive key issues of the decision-making process.
  相似文献   
105.

Background

As HIV remains a public health concern, increased testing among those at risk for HIV acquisition is important. Men who have sex with men (MSM) are the most important group for targeted HIV testing in Europe. Several new strategies have been developed and implemented to increase HIV-testing uptake in this group, among them the Swab2know project.

Objective

In this project, we aim to assess the acceptability and feasibility of outreach and online HIV testing using oral fluid samples as well as Web-based delivery of test results.

Methods

Sample collection happened between December 2012 and April 2014 via outreach and online sampling among MSM. Test results were communicated through a secured website. HIV tests were executed in the laboratory. Each reactive sample needed to be confirmed using state-of-the-art confirmation procedures on a blood sample. Close follow-up of participants who did not pick up their results, and those with reactive results, was included in the protocol. Participants were asked to provide feedback on the methodology using a short survey.

Results

During 17 months, 1071 tests were conducted on samples collected from 898 men. Over half of the samples (553/1071, 51.63%) were collected during 23 outreach sessions. During an 8-month period, 430 samples out of 1071 (40.15%) were collected from online sampling. Additionally, 88 samples out of 1071 (8.22%) were collected by two partner organizations during face-to-face consultations with MSM and male sex workers. Results of 983 out of 1071 tests (91.78%) had been collected from the website. The pickup rate was higher among participants who ordered their kit online (421/430, 97.9%) compared to those participating during outreach activities (559/641, 87.2%; P<.001). MSM participating during outreach activities versus online participants were more likely to have never been tested before (17.3% vs 10.0%; P=.001) and reported more sexual partners in the 6 months prior to participation in the project (mean 7.18 vs 3.23; P<.001). A total of 20 participants out of 898 (2.2%) were confirmed HIV positive and were linked to care. Out of 1071 tests, 28 (2.61%) with a weak reactive result could not be confirmed, and were thereby classified as false reactive results. Most of the 388 participants who completed posttest surveys (388/983, 39.5%) were very positive about their experience. The vast majority (371/388, 95.6%) were very satisfied, while 17 out of 388 (4.4%) reported mixed feelings.

Conclusions

Despite a high yield and a considerable number of false reactive results, satisfaction was high among participants. The project helped us to reach the target population, both in numbers of tests executed and in newly diagnosed HIV infections. Further optimization should be considered in the accuracy of the test, the functionalities of the website (including an online counseling tool), and in studying the cost effectiveness of the methodology.  相似文献   
106.
107.
As a consequence of the use of fluoroquinolones (FQ), resistance to FQ has emerged, leading to cases of nearly untreatable and extensively drug-resistant tuberculosis. Mutations in DNA gyrase represent the main mechanism of FQ resistance. A full understanding of the pattern of mutations found in FQ-resistant (FQr) clinical isolates, and of their proportions, is crucial for improving molecular methods for the detection of FQ resistance in Mycobacterium tuberculosis. In this study, we reviewed the detection of FQ resistance in isolates addressed to the French National Reference Center for Mycobacteria from 2007 to 2012, with the aim of evaluating the performance of PCR sequencing in a real-life context. gyrA and gyrB sequencing, performed prospectively on M. tuberculosis clinical isolates, was compared for FQ susceptibility to 2 mg/liter ofloxacin by the reference proportion method. A total of 605 isolates, of which 50% were multidrug resistant, were analyzed. The increase in FQr strains among multidrug-resistant (MDR) strains during the time of the study was alarming (8% to 30%). The majority (78%) of the isolates with gyrA mutations were FQr, whereas only 36% of those with gyrB mutations were FQr. Only 12% of the FQr isolates had a single mutation in gyrB. Combined gyrA and gyrB sequencing led to >93% sensitivity for detecting resistance. The analysis of the four false-positive and the five false-negative results of gyrA and gyrB sequencing illustrated the actual limitations of the reference proportion method. Our data emphasize the need for combined gyrA and gyrB sequencing in the investigation of FQ susceptibility in M. tuberculosis and challenge the validity of the current phenotype-based approach as the diagnostic gold standard for determining FQ resistance.  相似文献   
108.
109.
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