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   4787篇
  免费   314篇
  国内免费   28篇
耳鼻咽喉   75篇
儿科学   111篇
妇产科学   148篇
基础医学   625篇
口腔科学   209篇
临床医学   465篇
内科学   903篇
皮肤病学   160篇
神经病学   204篇
特种医学   143篇
外科学   832篇
综合类   79篇
一般理论   3篇
预防医学   337篇
眼科学   81篇
药学   483篇
中国医学   34篇
肿瘤学   237篇
  2024年   5篇
  2023年   47篇
  2022年   142篇
  2021年   194篇
  2020年   129篇
  2019年   179篇
  2018年   223篇
  2017年   171篇
  2016年   177篇
  2015年   193篇
  2014年   271篇
  2013年   316篇
  2012年   432篇
  2011年   431篇
  2010年   248篇
  2009年   192篇
  2008年   264篇
  2007年   231篇
  2006年   210篇
  2005年   187篇
  2004年   149篇
  2003年   128篇
  2002年   113篇
  2001年   36篇
  2000年   42篇
  1999年   39篇
  1998年   22篇
  1997年   22篇
  1996年   26篇
  1995年   20篇
  1994年   15篇
  1993年   18篇
  1992年   18篇
  1991年   22篇
  1990年   24篇
  1989年   18篇
  1988年   14篇
  1987年   27篇
  1986年   25篇
  1985年   13篇
  1984年   8篇
  1983年   11篇
  1982年   10篇
  1981年   9篇
  1980年   11篇
  1979年   5篇
  1978年   5篇
  1971年   8篇
  1970年   4篇
  1966年   4篇
排序方式: 共有5129条查询结果,搜索用时 15 毫秒
51.
The present study comprised 1000 child and young workers in small and medium-size industries in Alexandria, as well as 250 control subjects. Almost all young workers work for more than 40 hours/week and suffer from fatigue. Workers' family needs rather than the lack of family care is the responsible factor for sending the child to work, and the economic problems seem to be the underlying factor for all other problems of child labour. Work improves labourers' socio-economic status and smoking habit, and provides a chance for their personal contacts and interactions, which are reflected on their level of intellectual capabilities; however, it has some impact on their food habits affecting their achievement of balanced diet; and no drug addiction exists among all the studied subjects. Noise and dust represent the main occupational exposures (84.4% and 55.8% respectively), followed by exposure to heat (25.3%), vapors and gases (10.4%) and biological materials (9.0%), and nearly 2/3 of the workers have combined exposures. Work injuries occurred to 18.4% of the workers and 7.4% had more than one injury during employment; however, nearly 1/3 of the injuries required absenteeism off work and/or hospitalization. The injuries have been typically related to industrial operations, occurring mostly to hands and fingers (80.4%), and are mainly attributed to lack of training (63.0%). The health services presented to the workers are very poor. The study has been concluded by recommending making the work safe, free from hazards, and ergonomically fit to children, providing educational and training services, covering young workers by social security, and revising legislation of child labour.  相似文献   
52.
A HPLC assay and solid-phase extraction technique from human plasma has been developed and validated for the novel anticancer agent CT2584, 1-(11-dodecylamino-10-hydroxyundecyl)-3,7-dimethylxanthine, which has recently completed a phase I trial at the Christie Hospital, Manchester under the auspices of the CRC phase I/II committee. Following addition of CT2576, 1-(11-octylamino-10-hydroxylundecyl)-3,7-dimethylxanthine, as internal standard, a solid-phase extraction cartridge (100 mg cyanopropyl) was used to isolate the drug CT2584 from human plasma. Analysis was performed by reversed-phase chromatography. CT2576 was used as internal standard at a concentration of 4 microg ml(-1) for the quantification of CT2584 from plasma for the duration of this work. The lower limit of quantification for the drug CT2584 in buffer using this assay was found to be 0.0122 microM (0.008 microg ml(-1)) and 0.048 microM (0.027 microg ml(-1)) when extracted from human plasma.  相似文献   
53.
54.
It is known that BK does play a role in the cardioprotective effect of angiotensin converting enzyme (ACE) inhibitors. The present study therefore was conducted to examine the effects of bradykinin (BK) and its antagonist on survival time in spontaneously hypertensive rats (SHR) with coronary artery ligation for 15 min and continuously. We also evaluated the heart rate and blood pressure (BP) in the presence and absence of BK and BK2 receptor antagonist, D-Arg-[Hyp-D-Phe7]BK. Coronary artery was ligated in anaesthetized rats and they were artificially ventilated with room air (stroke volume, 4 ml; 48 strokes/min) as described by the previous investigators. Lead II elecrocardiogram (ECG) was recorded from subcutaneous steel needle electrodes. Results of this investigation indicated that BK treatment 4 microg/kg (i.v.) and 8 microg/kg (i.v.) caused significant (P < 0.05) increase in survival time in SHR with coronary artery ligation for 15 min and continuously as compare to their respective saline-treated controls. However, BK antagonist treatment 4 microg/kg (i.v.) abolished the increase in survival time caused by BK treatment. The mean values of survival time between the saline-treated and BK antagonist plus BK-treated rats did not differ significantly (P > 0.05). The heart rate and BP responses were greatly reduced (P < 0.001) in the presence of coronary artery ligation. These findings suggest that BK might have cardioprotective effect to increase the survival time in rats by activating BK2 receptors after coronary artery ligation.  相似文献   
55.
56.
57.
58.
59.
With growing evidence of long-term neurological damage in individuals enduring repetitive head trauma, it is critical to detect lower-level damage accumulation for the early diagnosis of injury in at-risk populations. Proton magnetic resonance spectroscopic scans of the dorsolateral prefrontal cortex and primary motor cortex were collected from high school American (gridiron) football athletes, prior to and during their competition seasons. Although no concussions were diagnosed, significant metabolic deviations from baseline and non-collision sport controls were revealed. Overall the findings indicate underlying biochemical changes, consequential to repetitive hits, which have previously gone unnoticed due to a lack of traditional neurological symptoms.  相似文献   
60.
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