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   378831篇
  免费   24172篇
  国内免费   2809篇
耳鼻咽喉   5183篇
儿科学   8199篇
妇产科学   10079篇
基础医学   53092篇
口腔科学   11772篇
临床医学   30074篇
内科学   78229篇
皮肤病学   8545篇
神经病学   27180篇
特种医学   13908篇
外国民族医学   82篇
外科学   60545篇
综合类   9953篇
现状与发展   1篇
一般理论   64篇
预防医学   17416篇
眼科学   9437篇
药学   30966篇
  1篇
中国医学   2194篇
肿瘤学   28892篇
  2021年   2606篇
  2019年   2721篇
  2018年   4513篇
  2017年   3428篇
  2016年   3515篇
  2015年   4015篇
  2014年   5690篇
  2013年   7367篇
  2012年   10007篇
  2011年   10188篇
  2010年   6181篇
  2009年   5833篇
  2008年   9436篇
  2007年   10272篇
  2006年   10192篇
  2005年   9254篇
  2004年   8766篇
  2003年   8503篇
  2002年   8180篇
  2001年   28236篇
  2000年   28769篇
  1999年   23645篇
  1998年   5161篇
  1997年   4249篇
  1996年   3829篇
  1995年   3478篇
  1994年   3103篇
  1993年   2843篇
  1992年   16046篇
  1991年   14811篇
  1990年   14153篇
  1989年   13958篇
  1988年   12579篇
  1987年   12059篇
  1986年   11101篇
  1985年   10320篇
  1984年   6911篇
  1983年   5600篇
  1982年   2718篇
  1979年   5477篇
  1978年   3347篇
  1977年   2971篇
  1975年   2641篇
  1974年   3064篇
  1973年   2865篇
  1972年   2828篇
  1971年   2773篇
  1970年   2510篇
  1969年   2543篇
  1968年   2250篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
Previous studies have sometimes found a positive relationship between platelet monoamine oxidase (MAO) activity and dexamethasone nonsuppression in depressed patients. To assess this relationship in more detail, we examined the association between these two biological variables in unmedicated depressed patients. A positive correlation between platelet MAO activity and 8:00 AM serum cortisol levels following an overnight dexamethasone test (1 mg) was observed. The relationship between high and low platelet MAO activity (median split) and suppression of serum cortisol levels was also significant. These relationships were stronger in bipolar patients. Multiple regression revealed that postdexamethasone 8:00 AM dexamethasone levels and platelet MAO activity were independent predictors of the 8:00 AM cortisol levels following dexamethasone. The possibility that platelet MAO activity may be a peripheral marker of brain serotonergic activity which in turn may affect various aspects of the hypothalamo-pituitary-adrenal axis activity, is discussed. We also found that all nine depressed patients studied greater than or equal to 15 days after admission were suppressors. Platelet MAO activity, but not 8:00 AM pre- or postdexamethasone serum cortisol, was related to the severity of depression.  相似文献   
952.
A 43-year-old man with idiopathic hypereosinophilic syndrome survived a relatively long term (6 1/2 years) before he succumbed to intractable heart failure. Six months before death, his chronic heart failure from restrictive cardiomyopathy was well compensated. Autopsy demonstrated severe constrictive pericarditis which was not suspected antemortem. Constrictive pericarditis as a late complication of idiopathic hypereosinophilic syndrome is discussed.  相似文献   
953.
Two groups (n = 10 in each) of adult sheep were exposed to hemorrhagic shock resulting in mean arterial pressure (MAP) below 25 mmHg for 10 min. Following that, group A received crystalloids (8% of body wt) during one hr together with supraceliac intraaortic balloon tamponade during the first 30 min, while group B (controls) received crystalloids only. The central circulation was rapidly restored in group A, as indicated by increased MAP and increased systemic vascular resistance (SVR). After deflation of the balloon MAP dropped to the same value as in the control group, while cardiac index increased gradually with volume replacement and was significantly higher at the end of the resuscitation period (60 min) than in the control group (P less than 0.05). Despite a more rapid restoration of central hemodynamics in group A, lactic acidosis was more severe, acute renal failure and neurological complications more frequent, and mortality higher than in the control group. It was concluded that continuous supraceliac aortic occlusion for 30 min had deleterious effects on organs dependent on aortic blood flow distal to the aortic tamponade and may contribute to the development of multiple organ failure after resuscitation from hemorrhagic shock. Further studies are needed to evaluate the effects of intermittent intraaortic balloon tamponade in hemorrhagic shock.  相似文献   
954.
Rabies in Malaysia   总被引:1,自引:0,他引:1  
  相似文献   
955.
956.
Metastatic septic endophthalmitis in pyogenic liver abscess   总被引:4,自引:0,他引:4  
In a consecutive series of 180 patients with pyogenic liver abscess, three patients (two men and one woman, between 46 and 75 years of age) had metastatic Klebsiella endophthalmitis. The incidence of metastatic endophthalmitis was 1.7% in patients with pyogenic liver abscess, 5.2% in patients with Klebsiella liver abscess, and 7.8% in patients with Klebsiella liver abscess having Klebsiella bacteremia. Despite aggressive therapeutic measures, the men permanently lost their vision and the woman eventually required an evisceration of her right eye. Delayed recognition and/or treatment as well as the nature of bacteria probably contributed to the tragic outcome. The findings suggest that a high index of suspicion is critical and a combined effort of the internist and ophthalmologist is mandatory.  相似文献   
957.
A 44-year-old housewife was found to have coarctation of the abdominal aorta secondary to Takayasu's arteritis. Since she also had mitral stenosis, possible etiological relation between Takayasu's arteritis and mitral stenosis is suspected.  相似文献   
958.
Kent bundle interruption for ventricular preexcitation has been successfully accomplished utilizing several different surgical techniques. The external closed-heart technique of Guiraudon combining surgical dissection and cryoablation has been used to interrupt 52 accessory pathways in 47 consecutive patients since May, 1985. The 35 male and 12 female patients ranged in age from 10 to 67 years (mean, 30 years). There were 25 left free wall, 13 right free wall, 13 posterior septal, and 1 anterior septal accessory pathways. Preoperative and intraoperative electrophysiological studies were performed in all patients to induce the arrhythmia and localize all accessory pathways. The operation consisted of dissection of the atrioventricular fat pad. Following this, the delta wave and retrograde accessory pathway conduction disappeared, thereby indicating successful pathway ablation. In 4 patients with right-sided accessory pathways, interruption of the pathway required cryoablation. Cryolesions (made with cryoprobe at -60 degrees C for two minutes) were created in the region of the accessory pathway insertion. All accessory pathways were successfully ablated without any deaths or heart block. Concomitant surgical procedures were performed in 4 patients. Two patients required a second operation the next day for an accessory pathway not found at the initial operation. Three patients had postpericardiotomy syndrome, and 4 had recurrent atrial fibrillation requiring therapy. The remaining patients have had no arrhythmia recurrence and have remained drug free after a follow-up of 1 month to 22 months (mean, 12.5 months). We conclude that the closed-heart technique of accessory pathway ablation is safe and reproducible, obviates the necessity for aortic cross-clamping and cardioplegic arrest, and allows instantaneous monitoring of conduction over the pathway.  相似文献   
959.
960.
Serum myoglobin levels have been found to be elevated for a few hours after removal of a tourniquet. In the present study, levels of serum myoglobin were measured by radioimmunoassay from local blood samples in patients who were treated with surgery of the hand in a bloodless field. After removal of the tourniquet blood samples were obtained from the antecubital vein of each patient immediately after release, five minutes, one hour, and 24 hours later. In these samples the serum myoglobin levels were not influenced by the mode of anesthesia, tourniquet time, or specific type of surgery. When the upper extremity was cooled with ice water before application of the tourniquet, however, the increase of serum myoglobin was statistically significantly inhibited when compared with the normothermic condition. Muscle injury due to tourniquet ischemia may be decreased by cooling of the upper extremity prior to tourniquet application.  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