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   368篇
  免费   12篇
  国内免费   2篇
耳鼻咽喉   4篇
儿科学   45篇
妇产科学   3篇
基础医学   28篇
口腔科学   15篇
临床医学   12篇
内科学   57篇
神经病学   16篇
特种医学   3篇
外科学   46篇
综合类   5篇
预防医学   18篇
眼科学   89篇
药学   23篇
中国医学   1篇
肿瘤学   17篇
  2022年   13篇
  2021年   15篇
  2020年   10篇
  2019年   10篇
  2018年   20篇
  2017年   10篇
  2016年   10篇
  2015年   12篇
  2014年   16篇
  2013年   32篇
  2012年   25篇
  2011年   28篇
  2010年   15篇
  2009年   14篇
  2008年   16篇
  2007年   17篇
  2006年   23篇
  2005年   15篇
  2004年   23篇
  2003年   23篇
  2002年   11篇
  2001年   3篇
  2000年   7篇
  1999年   2篇
  1998年   1篇
  1997年   2篇
  1992年   1篇
  1989年   1篇
  1988年   1篇
  1985年   1篇
  1981年   1篇
  1978年   1篇
  1976年   1篇
  1974年   1篇
  1972年   1篇
排序方式: 共有382条查询结果,搜索用时 0 毫秒
101.
In a 12-year-old girl with history of recurrent palpitation, an ambulatory 24 h Holter electrocardiogram showed a wide QRS complex rhythm with atrioventricular dissociation. During an electrophysiology study, an atriofascicular pathway was diagnosed with an inducible antidromic atrioventricular re-entrant tachycardia. At slower heart rates, the patient had a wide QRS complex escape rhythm similar to the tachycardia and the pre-excited QRS complex morphology. This indicates the presence of pacemaker-like cells in the atriofascicular accessory pathway giving rise to the wide QRS complex escape rhythm at a slower heart rate.  相似文献   
102.
In patients with an implantable cardioverter defibrillator, empirical antitachycardia pacing/burst pacing (ATP) is associated with a significantly decreased rate of appropriate shocks. The use of ATP as first-line therapy in ventricular tachycardia promotes less pain and better quality of life because the number of shocks is reduced. Additionally, battery longevity is substantially increased with this strategy. Based on this, device manufacturers have developed new algorithms to optimize the use of ATP and shocks in patients with an implantable cardioverter defibrillator. The present report describes a case in which the use of one of these new algorithms was associated with a significant delay in tachycardia termination and, consequently, led to syncope.  相似文献   
103.
Intercoronary artery continuity is a rare variant of coronary circulation. Here we report a case where we found an intercoronary communication between the left and the right coronary artery. Right coronary angiogram showed filling of the left coronary artery and the left coronary angiogram showed filling of the distal right coronary artery, demonstrating bidirectional flow. The coronary arteries were free of atherosclerotic occlusive disease. The case is reported for its rarity.  相似文献   
104.
105.
The potential for antiepileptic drugs to negatively impact cognitive abilities has generated renewed interest in herbal drugs and formulations in the treatment of epilepsy. Bacopa monnieri is one such widely used revitalizing herb that purportedly strengthens nervous function and also possesses memory-enhancing, antioxidative, antiepileptic, and anti-inflammatory properties. We investigated the neuroprotective role of B. monnieri extract in alteration of glutamate receptor binding and gene expression of NMDA R1 in hippocampus of temporal lobe epileptic rats. In association with pilocarpine-induced epilepsy, there was significant downregulation of NMDA R1 gene expression and glutamate receptor binding without any change in its affinity. B. monnieri treatment of epileptic rats significantly reversed the expression of NMDA R1 and glutamate receptor binding alterations to near-control levels. Also, in the epileptic rats, we measured a significant increase in the activity of glutamate dehydrogenase, which neared the control level after B. monnieri treatment. The therapeutic effect of B. monnieri was also observed in the Morris water maze experiment. These data together indicate the neuroprotective role of B. monnieri extract in glutamate-mediated excitotoxicity during seizures and cognitive damage occurring in association with pilocarpine-induced epilepsy.  相似文献   
106.
A 33-year-old male with idiopathic restrictive cardiomyopathy had dilated and tortuous veins over both lower limbs and over the scrotum with multiple hyperpigmented scars. He was in the habit of puncturing the veins to let out blood during episodes of worsening of dyspnoea, thereby relieving dyspnoea by decreasing the preload.  相似文献   
107.
108.
109.
Stem cell markers: ABCG2 and MCM2 expression in retinoblastoma   总被引:9,自引:0,他引:9  
BACKGROUND/AIM: The authors studied the expression of cancer stem cell surface marker, ABCG2, and neural stem cell marker, MCM2, in retinoblastoma and correlated clinicopathologically. METHODS: Among 39 retinoblastomas, 18 tumours were not subjected to preoperative/postoperative chemotherapy, 15 tumours underwent postoperative chemotherapy, and six tumours had preoperative chemotherapy. There were 20 tumours with no invasion and 19 tumours with invasion of choroid/optic nerve. ABCG2 and MCM2 expression was studied by immunohistochemistry. RESULTS: ABCG2 was positive in six of six and MCM2 was positive in five of six tumours that had recurred in the orbit or metastasised. ABCG2 was positive in 15/19 tumours with invasion. MCM2 was positive in 16/19 tumours with invasion. Invasive tumours showed higher expression of ABCG2 (p < 0.01) and MCM2 (p < 0.01) proteins. There was no correlation with differentiation and laterality of the tumours. Non-neoplastic retina was positive for ABCG2 and MCM2. CONCLUSION: ABCG2 and MCM2 were expressed more in invasive tumours. Further studies are needed to understand the significance of ABCG2 and MCM2 expression in retinoblastoma.  相似文献   
110.
OBJECTIVES: The specific objectives are threefold: to describe the biologically plausible mechanistic pathways by which exposure to particulate matter (PM) may lead to the adverse perinatal outcomes of low birth weight (LBW), intrauterine growth retardation (IUGR), and preterm delivery (PTD); review the evidence showing that nutrition affects the biologic pathways; and explain the mechanisms by which nutrition may modify the impact of PM exposure on perinatal outcomes. METHODS: We propose an interdisciplinary conceptual framework that brings together maternal and infant nutrition, air pollution exposure assessment, and cardiopulmonary and perinatal epidemiology. Five possible albeit not exclusive biologic mechanisms have been put forth in the emerging environmental sciences literature and provide corollaries for the proposed framework. CONCLUSIONS: Protecting the environmental health of mothers and infants remains a top global priority. The existing literature indicates that the effects of PM on LBW, PTD, and IUGR may manifest through the cardiovascular mechanisms of oxidative stress, inflammation, coagulation, endothelial function, and hemodynamic responses. PM exposure studies relating mechanistic pathways to perinatal outcomes should consider the likelihood that biologic responses and adverse birth outcomes may be derived from both PM and non-PM sources (e.g., nutrition). In the concluding section, we present strategies for empirically testing the proposed model and developing future research efforts.  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