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   378931篇
  免费   24197篇
  国内免费   2808篇
耳鼻咽喉   5185篇
儿科学   8199篇
妇产科学   10076篇
基础医学   53090篇
口腔科学   11775篇
临床医学   30090篇
内科学   78288篇
皮肤病学   8545篇
神经病学   27183篇
特种医学   13909篇
外国民族医学   82篇
外科学   60554篇
综合类   9961篇
现状与发展   1篇
一般理论   64篇
预防医学   17439篇
眼科学   9440篇
药学   30958篇
  1篇
中国医学   2200篇
肿瘤学   28896篇
  2021年   2614篇
  2019年   2724篇
  2018年   4521篇
  2017年   3434篇
  2016年   3526篇
  2015年   4018篇
  2014年   5692篇
  2013年   7374篇
  2012年   10009篇
  2011年   10187篇
  2010年   6182篇
  2009年   5837篇
  2008年   9437篇
  2007年   10270篇
  2006年   10196篇
  2005年   9258篇
  2004年   8765篇
  2003年   8501篇
  2002年   8181篇
  2001年   28213篇
  2000年   28768篇
  1999年   23620篇
  1998年   5158篇
  1997年   4247篇
  1996年   3828篇
  1995年   3480篇
  1994年   3104篇
  1993年   2843篇
  1992年   16050篇
  1991年   14816篇
  1990年   14153篇
  1989年   13959篇
  1988年   12580篇
  1987年   12064篇
  1986年   11103篇
  1985年   10323篇
  1984年   6913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 15 毫秒
131.
Complications following ureteroscopy   总被引:1,自引:0,他引:1  
We report 4 cases of ureteral injury and stricture formation following ureteroscopic stone manipulation. Possible etiologies of stricture formation and our methods of managing them are discussed. The complications of ureteroscopy have been reported only rarely and the ureteroscopist should be aware that the procedure is not always benign.  相似文献   
132.
OBJECTIVE: Avoidance of potential iatrogenic nerve injury during insertion of Ilizarov fine wires into areas of high anatomic risk by using a modified nerve stimulation technique. INDICATIONS: Application of the Ilizarov ring fixator to areas of high anatomic hazard, in situations where anatomic topography may be distorted by previous surgery, trauma, or congenital anomalies. CONTRAINDICATIONS: Use of systemic muscle relaxants. Caution in patient with cardiac pacemaker. SURGICAL TECHNIQUE: Preliminary experiments showed that a standard nerve-stimulating device can deliver a negatively charged, monophasic square pulse of current through Ilizarov wires. During the application of an Ilizarov frame to potentially hazardous anatomic regions, providing no systemic muscle relaxants are used, a voltage field sufficient to cause nerves in close proximity to the Ilizarov wire to depolarize is produced. Identification of a distal muscle twitch provoked by the stimulation may indicate a potential for iatrogenic nerve injury. RESULTS: Results show that with the nerve stimulator set at 2.5 mA (pulsed at a frequency of 2 Hz), peripheral nerves are stimulated if they lie within 5 mm of the wires. Should a distal muscle twitch occur, wires should be repositioned so that equivalent stimulation produces no twitch. The technique was used during Ilizarov frame application in ten patients, with only a single occurrence of distal muscle twitches in a lower-leg frame. Following repositioning of the Ilizarov wire in this case, no further twitches were observed, indicating that no Ilizarov wire was inserted close to peripheral nerves. No neurologic impairment was present postoperatively.  相似文献   
133.
134.
135.
The effects of cepharanthin on inflammatory parameters such as neutrophil chemotaxis, phagocytosis and reactive oxygen species (ROS) generation, were examined. Cepharanthin significantly decreased the levels of O2-, H2O2, and OH. generated by neutrophils. H2O2 and OH. generated in a cell-free, xanthine-xanthine oxidase system were also reduced in the presence of cepharanthin. However, the drug did not affect neutrophil chemotaxis or phagocytosis. The present study indicates that cepharanthin is an effective ROS scavenger, exerting its anti-inflammatory action by reducing the potent ROS species excessively generated in tissues and organs, especially at the sites of inflammation.  相似文献   
136.
Endorectal ultrasonography was evaluated in the diagnosis of prostatic cancer, using a high frequency (7,5 MHz) mechanical sectorial endocavitary probe developed by the authors. In a first study, sonograms from a series of 213 patients were interpreted retrospectively without any knowledge of the clinical or pathological findings. Specificity for the diagnosis of cancer (true non-malignant/total non-malignant) reached 79%, whereas sensitivity (true malignant/total malignant) was only 48%. Pathology was available for 132 patients. In a second study, 72 ultrasonically guided biopsies were performed in patients presenting either with a suspicious induration without nodule (47 cases) or a palpable nodule (25 cases). Good quality biopsy specimens, and absence of complication were remarkable. However, the 10 cancer cases (5 diagnosed in each group) did not show sonographically clearly different from the remaining adenoma, prostatitis and normal cases.  相似文献   
137.
Fifty-four patients with 65 superficial malignant lesions were treated by local hyperthermia combined with radiation therapy at the National Cancer Center Hospital, Tokyo. Hyperthermia was delivered with an Aloka Model HMS-020 (2450 MHz) or with a horn-type applicator of BSD-1000 (80-90 MHz). Relatively small tumours, those less than 4 cm in thickness, were treated by using 2450 MHz while 80-90 MHz delivered through the horn-type applicator was used for tumours exceeding 5 cm in thickness. The radiation dose was 4 Gy twice a week or 2 Gy five times a week, the total dose being 40-60 Gy. A total of six to 10 hyperthermia treatments ranging from 40 to 60 min each, with the tumour heated to more than 42.5 degrees C, were given twice a week within 1 h following radiation therapy. Complete response was achieved in 16 of the 30 patients (55 per cent) treated with the 2450 MHz microwave, and partial response in seven others (23 per cent). Tumours treated with the BSD-1000 achieved complete response in 10 out of 33 patients (30 per cent) and partial response in nine others (27 per cent). In five out of nine patients classified as partial responders, however, complete disappearance of tumour cells was noted by post-treatment histological examination. Complete plus partial response rates were thus essentially the same with the Aloka HMS-020 and the BSD-1000, though the rate of complete response was apparently higher with the Aloka unit, probably because it was used on smaller tumours.  相似文献   
138.
139.
The growth of Plasmodium falciparum in erythrocytes from individuals with beta zero-thalassaemia or haemoglobin (Hb) E, or both, was assessed in vitro. A significant inhibitory effect on the growth of the parasite was found only with erythrocytes from individuals doubly heterozygous for beta zeros-thalassaemia and HbE. The inhibitory effect was particularly marked with erythrocytes from splenectomized beta zeros-thalassaemia/HbE patients. The protective effect was related to HbF, Hb levels and shape abnormalities of the variant erythrocytes.  相似文献   
140.
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