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   428篇
  免费   9篇
儿科学   63篇
妇产科学   1篇
基础医学   23篇
口腔科学   6篇
临床医学   46篇
内科学   107篇
皮肤病学   10篇
神经病学   27篇
外科学   70篇
综合类   4篇
预防医学   9篇
药学   39篇
肿瘤学   32篇
  2022年   2篇
  2017年   3篇
  2016年   4篇
  2015年   6篇
  2014年   3篇
  2013年   6篇
  2012年   7篇
  2011年   3篇
  2010年   7篇
  2009年   3篇
  2008年   2篇
  2007年   7篇
  2006年   25篇
  2005年   15篇
  2004年   13篇
  2003年   14篇
  2002年   7篇
  2001年   3篇
  2000年   6篇
  1999年   9篇
  1998年   30篇
  1997年   35篇
  1996年   33篇
  1995年   25篇
  1994年   24篇
  1993年   21篇
  1992年   10篇
  1991年   11篇
  1990年   8篇
  1989年   8篇
  1988年   2篇
  1986年   8篇
  1984年   6篇
  1983年   7篇
  1982年   3篇
  1981年   7篇
  1980年   7篇
  1979年   4篇
  1978年   4篇
  1977年   2篇
  1975年   2篇
  1973年   3篇
  1972年   5篇
  1971年   3篇
  1967年   2篇
  1961年   2篇
  1957年   2篇
  1956年   3篇
  1955年   4篇
  1954年   2篇
排序方式: 共有437条查询结果,搜索用时 0 毫秒
71.
1. The intravenous injection of I131-labeled heterologous anti-leukocyte and anti-bone marrow antibodies into rats resulted in a high specific in vivolocalization in the bone marrow, indicating the presence of localizing anti-body.

2. No in vivo localization in lungs was demonstrated, in possible contrastto the earlier concept of pulmonary emboli of clumped leukocytes sensitizedwith antibodies in experimental immunoleukopenia.

3. Heterologous anti-leukocyte and anti-bone marrow antibodies injectedintravenously disappeared from plasma and fixed to peripheral leukocytesand bone marrow cells within 1 hour.

Submitted on June 25, 1962 Accepted on December 24, 1962  相似文献   
72.
Multiple gastric carcinoma was endoscopically diagnosed in 14 patients (13.6%) with 33 lesions (27.3%), out of 103 cases of early gastric carcinoma treated by endoscopic surgery. The sex ratio of these patients was 11 males to 3 females, and their mean age was 61.7 years old. In 79% of the patients the macroscopic type of the lesions was the same. Twelve of 33 lesions were metachronous lesions diagnosed by endoscopy using the dye contrast method. All of the metachronous lesions were evaluated as invading only as far as the mucosa. Almost all of the metachronous lesions were located at a height similar to that of the initial lesion or in a more oral direction. Eleven of 12 metachronous lesions were less than 2 cm in diameter, including 5 minute cancer lesions which were less than 5 mm in size. All these lesions were treated again endoscopically without gastrectomy. These results suggest that an annual endoscopy using the dye contrast method permits early detection of gastric carcinoma at a stage at which it can be treated endoscopically.  相似文献   
73.
Postventricular Pacing Preexcitation. Antegrade conduction over a Kent bundle was transiently manifested after the cessation of ventricular overdrive pacing in two patients; otherwise, the heart behaved as if it had a concealed accessory pathway. Conventional electrophysiologic study suggested either a longitudinal dissociation of an accessory pathway or closely located double accessory pathways. The mechanism of the transient manifestation of ventricular preexcitation was discussed. (J Cardiovasc Electrophysiol, Vol. 3, pp. 423–430, October 1992)  相似文献   
74.
Patients with suspected Adams-Stokes syndrome are examined by Holter monitoring. During the monitoring, there is the danger of syncopes occurring and there are even reports of sudden cardiac death. We therefore developed a pacemaker for cardiac arrest monitoring and the prevention of Adams-Stokes syndrome and sudden cardiac death, which has the following functions: (1) the longest escape interval of the pacemaker not exceeding the value at which syncope is induced is determined by the decline of the mean heart rate including the asystole to a certain threshold rate; (2) once the pacemaker escapes from the interval it continues pacing for a while at a physiological rate to allow recover from ischemias in organs or tissues; and (3) to prevent overdrive suppression to the heart, the pacing rate gradually declines and stops pacing until the next asystole. This pacemaker is useful not only in the diagnosis of Adams-Stokes syndrome but also in pharmacological and pathophysiological studies and in determining when pacing should cease.  相似文献   
75.
Intestinal brush-border membrane transport of monocarboxylic acids was investigated by using rabbit intestinal brush-border membrane vesicles (BBMVs) and isolated intestinal tissues mounted on Ussing-type chambers. [3H]Mevalonic acid uptake by BBMVs showed an overshoot phenomenon in the presence of an inwardly directed proton gradient, but not in the presence of an inwardly directed sodium gradient or an outwardly directed HCO3? or chloride gradient. Initial uptake of mevalonic acid was saturable in the presence of a proton gradient. Uptake of [3H]mevalonic acid was inhibited by various monocarboxylic acids, including acetic acid, benzoic acid, lactic acid, nicotinic acid, pravastatin, salicylic acid and valproic acid, but not by dicarboxylic acid or amino acids. Acetic acid, which is transported by both anion antiport and proton-coupled transport systems, induced serosal bicarbonate-dependent alkalinization in the mucosal-side bathing solution of rabbit jejunal tissues, when examined in Ussing-type chambers. Pravastatin, which is a structural analogue of mevalonic acid and is absorbed via proton-coupled transport like mevalonic acid, did not. The result demonstrates that acetic acid is transported by the bicarbonate-dependent anion antiport system, whereas pravastatin is not. So, it is suggested that monocarboxylic acids are transported by at least two independent transporters, namely, a proton-coupled transporter for most monocarboxylic acids, including mevalonic acid, pravastatin and acetic acid, and an anion antiporter for acetic acid, but not for mevalonic acid or pravastatin. Activation of anion antiporter can induce HCO3? secretion in intact intestine.  相似文献   
76.
77.
We report a case of a young child affected by triple cancerswho developed a pleomorphic rhabdomyosarcoma of the retroperitoneumfollowing prophylactic chemotherapy after surgery for doubleprimary adrenocortical carcinoma and ganglioneuroblastoma. It is suggested that genetic susceptibility and chemotherapymight be responsible for the development of rhabdomyosarcomaas the second malignant neoplasm.  相似文献   
78.
Incidences of f and rßs components were studied inserum samples from patients with various malignant and non-malignantdiseases. With the micro-Ouchterlony method, af was detectedexclusively in cases of hepatocellular carcinoma of which theincidence was 83.5%, whereas the incidence of rßswas 47.7%. However, rßs was also detected in somemalignant disease other than hepatocellular carcinoma, withan incidence of 16.5%, and was also detected in a small numberof cases of non-neoplastic liver diseases. Though not tumor-specific, rßs as one of the fetalserum proteins can be detected in cases of non-f-producing hepatomaand in cases of malignancies other than hepatoma. Thus, thedetection of this protein may be of diagnostic significance.Possible mechanism of the appearance of this protein in theblood was discussed.  相似文献   
79.
The conditions associated prior to and during the transition from prestretch to shortering may have considerable influence on the final performance of muscle. In the present study male subjects of good physical condition performed vertical jumps on the force-platform with and without preliminary counter movement. In the counter movement jump (CMJ) the amplitude of the knee bending, velocity of the prestretch and the force attained at end of prestretch were the primary parameters of interest. In addition the coupling time indicating the transition from the eccentric (prestretch) phase to the concentric phase was recorded from the angular displacement and reaction force curves. In the final calculation the mechanical performance parameters of CMJ were always compared with those of the jumps performed without counter movement. The results indicated in general first that CMJ enhanced the average concentric force and average mechanical power by 423 N (66%) and 1158 W (81%), respectively. This potentiation effect was the higher the higher was the force at end of prestretch (p<0.001). Similarly, the prestretch speed (p<0.001) and short coupling time (p<0.01) were associated with enhanced performance during the concentric phase. The average coupling time was 23 ms. The results are interpreted through changes in the prestretch conditions to modify the acto-myosin cross-bridge formation so that the storage and utilization of elastic energy is associated with high prestretch speed, high eccentric force and short coupling time. The role of the reflex potentiation is also suggested as additional enhancement of the final performance.  相似文献   
80.
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