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   162篇
  免费   6篇
  国内免费   9篇
儿科学   4篇
妇产科学   3篇
基础医学   10篇
口腔科学   5篇
临床医学   12篇
内科学   54篇
皮肤病学   12篇
神经病学   5篇
外科学   42篇
综合类   11篇
预防医学   6篇
眼科学   4篇
药学   5篇
中国医学   3篇
肿瘤学   1篇
  2022年   1篇
  2019年   1篇
  2017年   2篇
  2016年   2篇
  2015年   5篇
  2014年   8篇
  2013年   9篇
  2012年   5篇
  2011年   2篇
  2010年   16篇
  2009年   19篇
  2008年   8篇
  2007年   5篇
  2006年   10篇
  2005年   6篇
  2003年   2篇
  2002年   1篇
  2000年   1篇
  1999年   4篇
  1998年   9篇
  1997年   11篇
  1996年   8篇
  1995年   7篇
  1994年   2篇
  1993年   4篇
  1992年   2篇
  1990年   2篇
  1989年   1篇
  1986年   1篇
  1985年   4篇
  1982年   1篇
  1981年   1篇
  1964年   3篇
  1962年   2篇
  1960年   1篇
  1959年   2篇
  1957年   4篇
  1956年   2篇
  1955年   1篇
  1954年   1篇
  1948年   1篇
排序方式: 共有177条查询结果,搜索用时 31 毫秒
51.
52.
The purpose of this study was investigating the effects of curcumin on the histological changes and functional recovery following spinal cord injury (SCI) in a rat model. Following either sham operation or SCI, 36 male Sprague–Dawley rats were distributed into three groups: sham group, curcumin-treated group, and vehicle-injected group. Locomotor function was assessed according to the Basso, Beattie, and Bresnahan (BBB) scale in rats who had received daily intraperitoneal injections of 200 mg/kg curcumin or an equivalent volume of vehicle for 7 days following SCI. The injured spinal cord was then examined histologically, including quantification of cavitation. BBB scores were significantly higher in rats receiving curcumin than receiving vehicle (P < 0.05). The cavity volume was significantly reduced in the curcumin group as compared to the control group (P = 0.039). Superoxide dismutase (SOD) activity was significantly elevated in the curcumin group as compared to the vehicle group but was not significantly different from the sham group (P < 0.05, P > 0.05, respectively) at one and two weeks after SCI. Malondialdehyde (MDA) levels were significantly elevated in the vehicle group as compared to the sham group (P < 0.05 at 1 and 2 weeks). MDA activity was significantly reduced in the curcumin group at 2 weeks after SCI when compared to the vehicle group (P = 0.004). The numbers of macrophage were significantly decreased in the curcumin group (P = 0.001). This study demonstrated that curcumin enhances early functional recovery after SCI by diminishing cavitation volume, anti-inflammatory reactions, and antioxidant activity.  相似文献   
53.
Acrodermatitis enteropathica is a rare hereditary or acquired disorder of hypozincemia. It is characterized by acral and periorificial dermatitis, alopecia, diarrhea and growth retardation. Anorexia nervosa is characterized by low body weight, body image distortion with an obsessive fear and is also associated with various cutaneous findings including acrodermatitis enteropathica. We report a 37‐year‐old female with acrodermatitis enteropathica showing acquired zinc deficiency with anorexia nervosa.  相似文献   
54.
Background and Aim: Differences in the prevalence of non‐alcoholic fatty liver disease (NAFLD) between Eastern and Western populations are primarily attributable to differences in definitions and biased population selection. Thus, the aim of the present study was to accurately determine the actual prevalence of NAFLD by sonography and to characterize the risk factors for NAFLD. Methods: The present cross‐sectional study was performed with data obtained from 6648 subjects, all of whom were older than 20 years of age (3530 men and 3118 women). The term ‘non‐drinker’ was applied to men who consumed less than 30 g alcohol/day and to women who consumed less than 20 g alcohol/day. Non‐alcoholic fatty liver disease was defined as a sonographically detected fatty liver in the absence of viral hepatitis in a non‐drinker. Results: Of the 1613 subjects who were diagnosed with sonographic fatty liver, 1240 were non‐drinkers and had no viral hepatitis. Overall, the unadjusted and age‐adjusted prevalences of NAFLD were 18.7% (23% in men, 13.7% in women) and 16.1% (21.6% in men, 11.2% in women), respectively. Multivariate analysis revealed that several risk factors were profoundly associated with the prevalence of NAFLD, including obesity, insulin resistance, hyperlipidemia and hyperglycemia in both genders, as well as age, menopausal status and estrogen medication in women only. Conclusions: These results demonstrate that the prevalence of NAFLD in Korean adults, according to sonographic surveys, is comparable to that seen in more developed countries. From the perspective of increasing obesity, the high prevalence rates noted in the study may herald an increased burden of chronic liver disease in the Korean population.  相似文献   
55.
In this article we have reviewed the mechanisms of atrial fibrillation (AF) with special emphasis on the thoracic veins. Based on a number of features, the thoracic veins are highly arrhythmogenic. The pulmonary vein (PV)-left atrial (LA) junction has discontinuous myocardial fibers separated by fibrotic tissues. The PV muscle sleeve is highly anisotropic. The vein of Marshall (VOM) in humans has multiple small muscle bundles separated by fibrosis and fat. Insulated muscle fibers can promote reentrant excitation, automaticity, and triggered activity. The PV muscle sleeves contain periodic acid-Schiff (PAS)-positive large pale cells that are morphologically reminiscent of Purkinje cells. These special cells could be the sources of focal discharge. Antiarrhythmic drugs have significant effects on PV muscle sleeves both at baseline and during AF. Both class I and III drugs have effects on wavefront traveling from PV to LA and from LA to PV. Separating the thoracic veins and the LA with ablation techniques also prevents PV-LA interaction. By reducing PV-LA interaction, pharmacological therapy and PV isolation reduce the activation rate in PV, intracellular calcium accumulation, and triggered activity. Therefore, thoracic vein isolation is an important technique in AF control. We conclude that thoracic veins are important in the generation and maintenance of AF.  相似文献   
56.
Current Concepts of Ventricular Defibrillation   总被引:2,自引:0,他引:2  
Mechanisms of Deflbhllation. The aim of this article is to review the current concepts of ventricular defibrillation. We studied the interaction between strong electrical stimulas and cardiac responses in both animal models and in humans. We found that a premature stimulus (S2) of appropriate strength results in figure-eight reentry in vitro by inducing propagated graded responses. The same stimulation protocol induces figure-eight reentry and ventricular fibrillation (VF) in vivo. When the S2 strength and the magnitude of graded responses increase beyond a critical level, the increase in refractoriness at the site of the stimulus becomes so long that the unidirectional block becomes bidirectional block, preventing the formation of reentry (upper limit of vulnerability [DLV]). In other studies, we found that the effects of an electrical stimulation on reentry is in part determined by the timing of the stimulus. A protective zone is present after the induction of VF and after an unsuccessful defibrillation shock during which an electrical stimulus can terminate reentry and protect the heart from VF. These results indicate that the effects of a defibrillation shock is dependent on both the strength and the timing of the shock. Timing is not important in areas where the shock field strength is < ULV because the shock terminates all reentry hut cannot reinitiate new ones. However, in areas where shock field strength is < ULV, the effects of the shock are determined by the timing of the shock relative to local VF activations. This ULV hypothesis of defibrillation explains the probablistic nature of ventricular defibrillation. It also indicates that, to achieve a high probability of successful defibrillation, a shock must result in a shock field strength of < ULV throughout the ventricles.  相似文献   
57.
Aim: The ankle brachial index (ABI) is a marker for peripheral artery disease and can predict mortality in advanced chronic kidney disease (CKD) and haemodialysis patients, respectively. However, it is seldom studied in Taiwan, an area with high prevalence of CKD and end‐stage renal disease. The aim of this study was to investigate the predictors for mortality by using ABI value in patients with CKD and undergoing haemodialysis in Taiwan. Methods: One hundred and sixty‐nine patients with CKD stage 3–5 and 231 haemodialysis patients were enrolled in one regional hospital. The mean follow‐up period was 23.3 ± 3.3 months. Patients were stratified into three groups according to ABI value (<0.9, ≥0.9 to <1.3, and ≥1.3). The relative mortality risk was analyzed by Cox‐regression methods. Results: In multivariate analysis, an ABI of 1.3 or more (hazard ratio, 3.846; P = 0.043) and coronary artery disease (P = 0.012) were positively associated with overall mortality, and serum low‐density lipoprotein cholesterol level (P = 0.042) was negatively associated with overall mortality. In addition, an ABI of less than 0.9 (P = 0.049), an ABI of 1.3 or more (P = 0.033), coronary artery disease (P = 0.024) and haemodialysis treatment (P = 0.043) were strong predictors for cardiovascular mortality. Conclusion: Our findings show that an ABI of 1.3 or more predicts for both overall and cardiovascular mortality, and an ABI of less than 0.9 predicts for cardiovascular mortality in CKD and haemodialysis patients. Screening patients with chronic renal failure by means of ABI may help to identify a high‐risk group for increased mortality.  相似文献   
58.
59.
A retrograde approach to the left ventricle (LV) from the femoral artery is most commonly used for left ventricular tachycardia (VT) ablation. However, as the patient population gets older, the prevalence of peripheral vascular disease and aortic valve disease increases, hampering the retrograde access to the LV, which may result in significant technical difficulties. The transseptal approach from the femoral vein is an alternative access to the LV. This approach has been effective for addressing LV VT originating from the posterior and posteroseptal region. However, the transseptal approach from the femoral vein is impossible if there are any obstacles in the inferior vena cava. There are also significant limitations in approaching the basal‐lateral region of the LV from this approach. We demonstrated the safety and feasibility of catheter ablation of LV VT via the transseptal approach from the right internal jugular vein. (J Cardiovasc Electrophysiol, Vol. 24, pp. 596–599, May 2013)  相似文献   
60.
Introduction: The underlying mechanisms of complex fractionated atrial electrogram (CFAE) during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) have not yet been clearly elucidated. We explored the relationships between CFAE and left atrial (LA) voltage, or conduction velocity (CV).
Methods and Results: In 50 patients with AF (23 paroxysmal AF [PAF], 41 males, mean age 55.76 ± 10.16 years), the CFAE (average index of fractionation of electrograms during AF by interval-analysis algorithm, cycle length [CL]≤ 120 ms) areas, voltage, and CV were measured at eight different quadrants in each patient's LA by analyzing a NavX-guided, color-coded CFAE CL map, a voltage map, and an isochronal map (500 ms pacing) generated by contact bipolar electrograms (70–100 points in the LA). The results were: (1) CFAE areas were predominantly located in the septum, roof, and LA appendage; (2) CFAE area had lower voltage than those in non-CFAE area and was surrounded by the areas of high voltage (P < 0.0001); (3) The CFAE areas had low CVs compared with non-CFAE areas (P < 0.001); and (4) The percentage of CFAE area was lower in patients with persistent atrial fibrillation (PeAF) compared with those with PAF (P < 0.05).
Conclusions: The CFAE area, which is primarily located at the septum, has a low voltage with a lower CV, and is surrounded by high-voltage areas. Underlying electroanatomical complexity is associated with clustering of CFAEs.  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