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   3537篇
  免费   196篇
  国内免费   18篇
耳鼻咽喉   49篇
儿科学   251篇
妇产科学   79篇
基础医学   472篇
口腔科学   92篇
临床医学   202篇
内科学   686篇
皮肤病学   37篇
神经病学   189篇
特种医学   103篇
外科学   696篇
综合类   76篇
预防医学   121篇
眼科学   126篇
药学   317篇
中国医学   18篇
肿瘤学   237篇
  2023年   35篇
  2022年   49篇
  2021年   144篇
  2020年   74篇
  2019年   102篇
  2018年   111篇
  2017年   71篇
  2016年   106篇
  2015年   120篇
  2014年   158篇
  2013年   173篇
  2012年   299篇
  2011年   327篇
  2010年   158篇
  2009年   128篇
  2008年   232篇
  2007年   206篇
  2006年   181篇
  2005年   172篇
  2004年   154篇
  2003年   122篇
  2002年   108篇
  2001年   46篇
  2000年   32篇
  1999年   28篇
  1998年   33篇
  1997年   26篇
  1996年   15篇
  1995年   14篇
  1993年   13篇
  1992年   22篇
  1991年   18篇
  1990年   11篇
  1989年   18篇
  1988年   22篇
  1987年   28篇
  1986年   18篇
  1985年   17篇
  1984年   10篇
  1983年   7篇
  1982年   8篇
  1981年   14篇
  1980年   11篇
  1979年   14篇
  1978年   9篇
  1977年   8篇
  1976年   11篇
  1974年   8篇
  1973年   11篇
  1968年   12篇
排序方式: 共有3751条查询结果,搜索用时 31 毫秒
1.
2.
3.
Deep brain stimulation (DBS) in psychiatric illnesses has been clinically tested over the past 20 years. The clinical application of DBS to the superolateral branch of the medial forebrain bundle in treatment‐resistant depressed patients—one of several targets under investigation—has shown to be promising in a number of uncontrolled open label trials. However, there are remain numerous questions that need to be investigated to understand and optimize the clinical use of DBS in depression, including, for example, the relationship between the symptoms, the biological substrates/projections and the stimulation itself. In the context of precision and customized medicine, the current paper focuses on clinical and experimental research of medial forebrain bundle DBS in depression or in animal models of depression, demonstrating how clinical and scientific progress can work in tandem to test the therapeutic value and investigate the mechanisms of this experimental treatment. As one of the hypotheses is that depression engenders changes in the reward and motivational networks, the review looks at how stimulation of the medial forebrain bundle impacts the dopaminergic system.  相似文献   
4.

Background

Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.

Methods

We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male).

Results

Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians.

Conclusions

Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation.  相似文献   
5.
OBJECTIVE: To evaluate the user experience and acceptability of an electronic patient monitoring system. SETTING AND PARTICIPANTS: 822 Military and civilian personnel at a health clinic at a major US military headquarters used an Internet and telephone-based electronic monitoring system to report vaccination-site responses and symptoms after receiving the smallpox vaccination. Focus groups of vaccinees were conducted to help develop a survey about the experience that was distributed to 379 vaccinees (96% completion rate). RESULTS: Users of the electronic monitoring system reported that it was fast and easy to use and reported they would use a system like this again and recommend an electronic monitoring system to a friend or relative. Most users (84%) were comfortable with a physician tracking their vaccine reaction using their electronic reports, but only half (51%) were comfortable with eliminating the post-vaccination follow-up visit with their health-care provider based on their electronic reports. CONCLUSIONS: This electronic monitoring system was well received by vaccinees and allowed health-care providers to track the status of vaccinees. However, vaccinees were not comfortable replacing a physician visit with electronic monitoring, at least for the smallpox vaccination. A monitoring system like this may be useful in public health settings, such as mass vaccination or prophylaxis during a bioterrorism event, a pandemic influenza outbreak, or another public health emergency.  相似文献   
6.
Background Extended trans septal (ETS) approach for mitral valve surgery often divides the artery to the Sino-Atrial node. The clinical implication of this is contentious. We analyzed our early results with ETS approach. Methods Between June 1998 and September 2003 eleven patients underwent mitral valve surgery by ETS approach. Six were females. Age ranged from 19 years to 67 years (median 40 years). Six underwent mitral valve replacement (MVR). Four underwent aortic and mitral (double) valve replacement (DVR). One had mitral valve repair. Three had additional procedures (tricuspid valve repair=1, Coronary artery bypass=1, Aorto bifemoral graft=1). Cardiopulmonary bypass ranged from 64 minutes to 77 minutes (median 72 minutes) for MVR and 112 minutes to 178 minutes (median 140 minutes) for DVR. Aortic cross clamp times ranged from 39 minutes to 52 minutes (median 47 minutes) for MVR and 74 minutes to 120 minutes (median 95 minutes) for DVR. Results There was no mortality or morbidity attributed to the ETS approach. One early death in emergency DVR was due to heart failure. Three patients needed seqeuntial pacing in the immediate post-operative period. Nine out of ten survivors were back to their preoperative rhythms on hospital discharge (6 sinus rhythm; 3 atrial fibrillation). One patient with preoperative trifascicular block who underwent reoperation to fix a paravalvular mitral leak needed a permanent pacemaker (VVI). The follow-up ranged from 1 month to 64 months (median 6 months) and is 100% complete. There was no late death or new arrhythmia. Conclusions Extended trans septal approach is safe. It gives excellent exposure of the mitral valve. division of the sinus node artery is not deleterious in the short to intermediate term. Presented at the 50th Annual Meeting of IACTS. New Delhi, Feb. 2004.  相似文献   
7.
8.
9.
10.
Magnetic resonance spectroscopic imaging (MRSI) provides spatially resolved metabolite information that is invaluable for both neuroscience studies and clinical applications. However, lengthy data acquisition times, which are a result of time-consuming phase encoding, represent a major challenge for MRSI. Fast MRSI pulse sequences that use echo-planar readout gradients, such as proton echo-planar spectroscopic imaging (PEPSI), are capable of fast spectral-spatial encoding and thus enable acceleration of image acquisition times. Combining PEPSI with recent advances in parallel MRI utilizing RF coil arrays can further accelerate MRSI data acquisition. Here we investigate the feasibility of ultrafast spectroscopic imaging at high field (3T and 4T) by combining PEPSI with sensitivity-encoded (SENSE) MRI using eight-channel head coil arrays. We show that the acquisition of single-average SENSE-PEPSI data at a short TE (15 ms) can be accelerated to 32 s or less, depending on the field strength, to obtain metabolic images of choline (Cho), creatine (Cre), N-acetyl-aspartate (NAA), and J-coupled metabolites (e.g., glutamate (Glu) and inositol (Ino)) with acceptable spectral quality and localization. The experimentally measured reductions in signal-to-noise ratio (SNR) and Cramer-Rao lower bounds (CRLBs) of metabolite resonances were well explained by both the g-factor and reduced measurement times. Thus, this technology is a promising means of reducing the scan times of 3D acquisitions and time-resolved 2D measurements.  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