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   1330篇
  免费   55篇
  国内免费   3篇
耳鼻咽喉   7篇
儿科学   56篇
妇产科学   17篇
基础医学   179篇
口腔科学   12篇
临床医学   90篇
内科学   251篇
皮肤病学   55篇
神经病学   72篇
特种医学   16篇
外科学   138篇
综合类   67篇
一般理论   1篇
预防医学   84篇
眼科学   85篇
药学   163篇
中国医学   10篇
肿瘤学   85篇
  2023年   9篇
  2022年   51篇
  2021年   74篇
  2020年   56篇
  2019年   55篇
  2018年   50篇
  2017年   32篇
  2016年   51篇
  2015年   54篇
  2014年   61篇
  2013年   76篇
  2012年   104篇
  2011年   97篇
  2010年   61篇
  2009年   49篇
  2008年   71篇
  2007年   47篇
  2006年   48篇
  2005年   44篇
  2004年   21篇
  2003年   31篇
  2002年   39篇
  2001年   25篇
  2000年   22篇
  1999年   16篇
  1998年   4篇
  1997年   3篇
  1996年   3篇
  1995年   4篇
  1994年   4篇
  1993年   4篇
  1992年   16篇
  1991年   15篇
  1990年   14篇
  1989年   6篇
  1988年   11篇
  1987年   3篇
  1986年   3篇
  1985年   5篇
  1984年   4篇
  1982年   2篇
  1980年   4篇
  1979年   3篇
  1978年   3篇
  1977年   6篇
  1976年   5篇
  1975年   4篇
  1972年   3篇
  1966年   5篇
  1965年   3篇
排序方式: 共有1388条查询结果,搜索用时 0 毫秒
71.
Objective To investigate the pharmacological effect of Nyctanthes arbortristis (NAT) leaf extract in the prevention of lung injury induced by silica particles. Method Lung injury was induced in Swiss mice through inhalation exposure to silica particles (<5μ) using a Flow Past Nose Only Inhalation Chamber at the rate of -10 mg/m3 respirable mass for 5 h. Lung bronchoalveolar lavage (BAL) fluid collected between 48 and 72 h was subjected to protein profiling by electrophoresis and cytokine evaluation by solid phase sandwich ELISA. Lung histopathology was performed to evaluate lung injury. Results Inhalation of silica increased the level of tumor necrosis factor-α(TNF-α), and of the 66 and 63 kDa peptides in the BAL fluid in comparison to sham-treated control. Pre-treatment of silica exposed mice with NAT leaf extract significantly prevented the accumulation of TNF-α in the BAL fluid, but the 66 and 63 kDa peptides remained unchanged. The extract was also effective in the prevention of silica-induced early fibrogenic reactions like congestion, edema and infiltration of nucleated cells in the interstitial alveolar spaces, and thickening of alveolar septa in mouse lung. Conclusion NAT leaf extract helps in bypassing silica induced initial lung injury in mice.  相似文献   
72.
BACKGROUND: Increasing evidence shows that red wine consumption has cardioprotective effects. These effects have been attributed to the polyphenolic compounds in grapes. OBJECTIVE: We studied the effects of red grape seed proanthocyanidins on the recovery of postischemic function in isolated rat hearts. DESIGN: Two groups of rats were fed different doses of proanthocyanidin-rich extract for 3 wk and another group was untreated and served as controls. The animals were then anesthetized and the hearts were isolated and subjected to 30 min of ischemia followed by 2 h of reperfusion. Coronary effluents were collected during the third minute of reperfusion for measurement of oxygen free radicals by using electron spin resonance spectroscopy. RESULTS: In rats treated with 50 and 100 mg grape seed proanthocyanidins/kg, the incidence of reperfusion-induced ventricular fibrillation was reduced from its control value of 92% to 42% and 25%, respectively (P < 0.05 for both). The incidence of ventricular tachycardia showed the same pattern. In rats treated with 100 mg proanthocyanidins/kg, the recovery of coronary flow, aortic flow, and developed pressure after 60 min of reperfusion was improved by 32% +/- 8%, 98% +/- 8%, and 37% +/- 3%, respectively (P < 0.05 for all) compared with untreated control rats. Electron spin resonance studies indicated that proanthocyanidins significantly inhibited the formation of oxygen free radicals. In rats treated with 100 mg proanthocyanidins/kg, free radical intensity was reduced by 75% +/- 7% (P < 0.05) compared with the control rats. CONCLUSION: Grape seed proanthocyanidins have cardioprotective effects against reperfusion-induced injury via their ability to reduce or remove, directly or indirectly, free radicals in myocardium that is reperfused after ischemia.  相似文献   
73.
A nosocomial outbreak of neonatal septicemia due toK. pneumoniae occurred in nursery during June–July, 1991.Klebsiella pneumoniae (Klebocin type 314) was recovered from blood of 33(70.2%) of 47 neonates with septicemia. Multiple drug resistance was observed in all the cases. The same strain ofK. pneumoniae was recovered from the neonates and environment of nursery and labour room as well. The outbreak was attributable to environmental dissemination.  相似文献   
74.
75.
76.
Four Modified Leprosy Elimination Campaigns (MLECs) were conducted in Orissa by March 2003. Their impact on various leprosy indicators was analyzed. More than 70% of the people of the State were examined during these campaigns. The suspect rate decreased from 1.44% to 0.37% towards the fourth MLEC. About 15% of the suspects were clinically confirmed to be having leprosy. The total number of new cases detected during the MLEC years was on the decrease. A marked fall in new case-detection rate was observed during inter-MLEC years. This has resulted in fluctuation in the prevalence rate during the MLEC years, but the overall PR/10,000 population decreased from 12.18 in 1996-97 to 7.3 in March 2003. More than 40% of the total new cases and about 45% of total new child cases for the corresponding year were detected during the MLECs, and the proportion of total new case-detection was as high as 60.8% during the first MLEC. The proportion of female cases detected during succeeding MLECs improved and an almost equal number of female cases were detected during MLECs III and IV. Considering the present leprosy situation in Orissa and the effectiveness of MLECs in case-detection, it was recommended that such campaigns should be undertaken in select high prevalent blocks of the State at regular intervals, along with the strengthening of the integration of NLEP activities into primary health care activities.  相似文献   
77.
Human response to blast induced ground vibration and air-overpressure/noise is a major concern of current mining activity. This is because the fact that mines are fast transgressing the habitats and people are getting educated. Consequently the response of humans is changing and expectedly will increase in days to come with no viable and economic alternative to blasting--an essential component of mining. The response of humans can be purely physiological or psychological in nature or combination of both depending upon the situation and conditions of mining. Where physiological response is documented in terms of effects on ears and lungs there is a meager amount or no literature available regarding effects of blasting on the brain. Moreover, the studies on transitory phenomenon like the effects of blasting on humans are rare in comparison to the whole body vibration studies. This study was designed to address the issues as a precursor to a major initiative. The preliminary investigations conducted with the monitoring of EEG responses of humans to vibration and air-overpressure/noise due to blasting revealed that there is no major response of the brain to transitory vibrations and noise.  相似文献   
78.
An attempt has been made to study the ability of patients with amyotrophic lateral sclerosis (ALS) to 'plan' a task. Electroencephalogram (EEG) data corresponding to 'planning of a movement task' is analyzed in comparison with a normal relaxed state. The study was conducted on 12 patients with ALS (6 males, 3 females, mean age 46.75 years) and on same number of controls (10 males, 2 females, mean age 48.75 years) to evaluate a difference in the ability to 'plan' a movement task between them. Patients with ALS were divided in two groups defined by unclear/clear speech. It has been observed that patients with ALS having unclear speech (Group I) showed considerable reduction (p<0.0001) in 'planning' a movement task, whereas patients with ALS having clear speech (Group II) showed no deficit in 'planning' a movement task (p=0.0577), both in comparison with age-matched controls. Apart from supporting the earlier reports of a possible extended neuronal degeneration across wide area of the frontal lobes, the findings reveal a possible reduction in planning, an executive function of the prefrontal cortex of brain, and also reveal that speech impairment may be associated with cognitive deficits in patients with ALS.  相似文献   
79.
80.
Beta-hydroxy-beta-methylbutyrate, more commonly referred to as HMB, is derived from the amino acid, leucine, and its keto acid, alpha-ketoisocaproate. In several studies combining HMB supplementation and resistance exercise, researchers have concluded that HMB may play an important role in reducing protein degradation and/or increasing recovery of damaged muscle cells. These actions could be advantageous to all individuals participating in exercise programs and improve the lives of many by overcoming weakness or frailty.  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