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   10120篇
  免费   512篇
  国内免费   58篇
耳鼻咽喉   71篇
儿科学   131篇
妇产科学   222篇
基础医学   1380篇
口腔科学   244篇
临床医学   2166篇
内科学   1085篇
皮肤病学   95篇
神经病学   342篇
特种医学   253篇
外科学   1521篇
综合类   640篇
预防医学   1371篇
眼科学   30篇
药学   613篇
  1篇
中国医学   78篇
肿瘤学   447篇
  2024年   5篇
  2023年   267篇
  2022年   573篇
  2021年   635篇
  2020年   630篇
  2019年   751篇
  2018年   796篇
  2017年   508篇
  2016年   346篇
  2015年   346篇
  2014年   891篇
  2013年   775篇
  2012年   451篇
  2011年   547篇
  2010年   435篇
  2009年   486篇
  2008年   385篇
  2007年   373篇
  2006年   304篇
  2005年   185篇
  2004年   174篇
  2003年   131篇
  2002年   92篇
  2001年   98篇
  2000年   75篇
  1999年   65篇
  1998年   42篇
  1997年   40篇
  1996年   34篇
  1995年   24篇
  1994年   28篇
  1993年   21篇
  1992年   21篇
  1991年   16篇
  1990年   17篇
  1989年   12篇
  1988年   14篇
  1987年   13篇
  1986年   7篇
  1985年   23篇
  1984年   9篇
  1983年   5篇
  1982年   9篇
  1981年   7篇
  1980年   4篇
  1979年   6篇
  1977年   5篇
  1975年   3篇
  1974年   1篇
  1973年   3篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.

Objective

The purpose of this study was to evaluate websites providing information on treatment for depression to the public, and to evaluate changes in the quality of website information over time.

Methods

Websites (N?=?25) addressing depression treatment were identified through the use of the Google search engine and by suggestions from healthcare professionals. Each website was evaluated based on the extent to which it addressed content areas deemed important by the public identified in previous research, overall quality as determined by the DISCERN, and reading level.

Results

Overall, the quality of depression websites varied greatly. The majority of websites did not adequately answer the public’s questions about treatment options, and presented higher quality information in the area of pharmacological treatments as compared to other treatment options. An average reading level of 10.0 was found across websites. Upon re-evaluation, only 14 of 25 websites added new content, and the majority of websites did not improve in their overall website quality (as measured by the DISCERN).

Conclusion and Practice Implications

Websites could be improved by addressing important questions that consumers have concerning depression, as well as by creating higher quality content in the areas of psychological, neurotherapeutic, and alternative treatments.  相似文献   
52.
The paper considers the limiting factors in EEG enhancement in the presence of electrosurgery interference and presents a design for a useful fibre-optic EEG monitoring instrument which is free from such problems as electrical shock (micro and macroshock), patient burns and susceptibility to electrosurgery interference associated with conventional EEG monitors.  相似文献   
53.
The direct measurement of blood pressure has found widespread use in intensive care units, operating rooms, and in emergency departments. Infection, air embolism and thrombosis are some of the risks to patients associated with both the cannulation procedure and with the apparatus used in the blood-pressure measuring process. Although there is constant revision in an attempt to reduce these risks, they cannot be completely eliminated. The need for direct blood-pressure measurements and the physiological effects of air embolism and thrombosis are reviewed. Infection and problems related to the techniques used to insert the catheters are not discussed.  相似文献   
54.
The heart-lung machines for open-heart surgery have improved over the past 50 years; they rarely break down and are almost always equipped with backup batteries. The hand-cranking procedure only becomes necessary when a pump breaks down during perfusion or after the batteries have run out. In this study, the performance of hand cranking a roller pump was quantitatively assessed by an objective method using the ECCSIM-Lite educational simulator system. A roller pump connected to an extracorporeal circuit with an oxygenator and with gravity venous drainage was used. A flow sensor unit consisting of electromagnetic sensors was used to measure arterial and venous flow rates, and a built-in pressure sensor was used to measure the water level in the reservoir. A preliminary study of continuous cranking by a team of six people was conducted as a surprise drill. This system was then used at a perfusion seminar. At the seminar, 1-min hand-cranking drills were conducted by volunteers according to a prepared scenario. The data were calculated on site and trend graphs of individual performances were given to the participants as a handout. Preliminary studies showed that each person's performance was different. Results from 1-min drills showed that good performance was not related to the number of clinical cases experienced, years of practice, or experience in hand cranking. Hand cranking to maintain the target flow rate could be achieved without practice; however, manipulating the venous return clamp requires practice. While the necessity of performing hand cranking during perfusion due to pump failure is rare, we believe that it is beneficial for perfusionists and patients to include hand-cranking practice in periodic extracorporeal circulation crisis management drills because a drill allows perfusionists to mentally rehearse the procedures should such a crisis occur.  相似文献   
55.
Recent developments in medical image acquisition combined with the latest advancements in numerical methods for solving the Navier-Stokes equations have created unprecedented opportunities for developing simple and reliable computational fluid dynamics (CFD) tools for meeting patient-specific surgical planning objectives. However, for CFD to reach its full potential and gain the trust and confidence of medical practitioners, physics-driven numerical modeling is required. This study reports on the experience gained from an ongoing integrated CFD modeling effort aimed at developing an advanced numerical simulation tool capable of accurately predicting flow characteristics in an anatomically correct total cavopulmonary connection (TCPC). An anatomical intra-atrial TCPC model is reconstructed from a stack of magnetic resonance (MR) images acquired in vivo. An exact replica of the computational geometry was built using transparent rapid prototyping. Following the same approach as in earlier studies on idealized models, flow structures, pressure drops, and energy losses were assessed both numerically and experimentally, then compared. Numerical studies were performed with both a first-order accurate commercial software and a recently developed, second-order accurate, in-house flow solver. The commercial CFD model could, with reasonable accuracy, capture global flow quantities of interest such as control volume power losses and pressure drops and time-averaged flow patterns. However, for steady inflow conditions, both flow visualization experiments and particle image velocimetry (PIV) measurements revealed unsteady, complex, and highly 3D flow structures, which could not be captured by this numerical model with the available computational resources and additional modeling efforts that are described. Preliminary time-accurate computations with the in-house flow solver were shown to capture for the first time these complex flow features and yielded solutions in good agreement with the experimental observations. Flow fields obtained were similar for the studied total cardiac output range (1–3 l/min); however hydrodynamic power loss increased dramatically with increasing cardiac output, suggesting significant energy demand at exercise conditions. The simulation of cardiovascular flows poses a formidable challenge to even the most advanced CFD tools currently available. A successful prediction requires a two-pronged, physics-based approach, which integrates high-resolution CFD tools and high-resolution laboratory measurements.  相似文献   
56.
A computerized decision support system is presented. The system is used to aid in the situation of patient selection for the purpose of dental education and utilizes the PERT/CPM methodology and decision tables. It runs on a microcomputer and written in Basic. The input is a list of patient's needs, and the output is a tentative treatment plan, the chair time needed to complete the treatment, its cost, and the probability that the student will finish it on time.  相似文献   
57.
This paper reports the results of a postal questionnaire completed by 2343 smokers who had contacted a television company for help with stopping smoking. Of these, 1848 (78.9%) completed a follow-up questionnaire 1 year later. This indicated that 797 had tried to stop, 709 had tried to cut down, and 164 had become abstinent. Analyses show that the intention to try to stop smoking was dependent not only on the perceived health benefit, but also on the subjects' confidence that they would succeed if they tried to stop. As predicted by Weiner's [(1979). J. Educ. Psychol.71: 3–25] model of achievement motivation, those who attributed other smokers' failures at quitting to stable factors had lower expectancies of success, as had those who saw themselves as more addicted. When the follow-up data are considered, reported attempts at quitting were strongly related to previously declared intentions, and reported abstinence was related to previous confidence (expectancy of success) and perceived addiction. There is no support for hypotheses concerning self-other differences in attribution, or defensive attribution, in subjects' attributions for their own failures at cessation. Implications for antismoking interventions are discussed.This research was facilitated to various extents by grants from the British Council, the Department of Health and Social Security, the Medical Research Council, and the Social Science Research Council, London. When the data were collected, all authors were at the Addiction Research Unit, Institute of Psychiatry, University of London.  相似文献   
58.
The clinical laboratory is regarded as a component of the medical care system extending from physician to laboratory staff and back to physician. From this concept a computer-based system of laboratory information is derived, emphasizing: (1) total laboratory responsibility for the test and its request, and (2) physician-oriented output reports.  相似文献   
59.
An inexpensive patient safety unit for a constant temperature hot-film anemometer is described. Both the so-called ‘electrical hazard’ and the thermal risk, which is special for the anemometer, have been eliminated.  相似文献   
60.
病历、电子病历与中医电子病历   总被引:2,自引:0,他引:2  
岳琳哲  施诚 《医学信息》2006,19(7):1121-1124
本文从中医病历的历史演化,西医病历的发展过程出发,对中西医病历的特点进行了分析,并对电子病历及中医电子病历作了一些简单的介绍。  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