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   2289篇
  免费   85篇
  国内免费   36篇
耳鼻咽喉   10篇
儿科学   29篇
妇产科学   72篇
基础医学   285篇
口腔科学   33篇
临床医学   139篇
内科学   368篇
皮肤病学   67篇
神经病学   351篇
特种医学   106篇
外科学   281篇
综合类   9篇
预防医学   271篇
眼科学   38篇
药学   219篇
中国医学   2篇
肿瘤学   130篇
  2023年   4篇
  2022年   21篇
  2021年   67篇
  2020年   38篇
  2019年   38篇
  2018年   49篇
  2017年   47篇
  2016年   54篇
  2015年   46篇
  2014年   78篇
  2013年   95篇
  2012年   176篇
  2011年   169篇
  2010年   97篇
  2009年   97篇
  2008年   170篇
  2007年   168篇
  2006年   171篇
  2005年   160篇
  2004年   161篇
  2003年   133篇
  2002年   131篇
  2001年   26篇
  2000年   17篇
  1999年   13篇
  1998年   25篇
  1997年   13篇
  1996年   10篇
  1995年   19篇
  1994年   12篇
  1993年   16篇
  1992年   6篇
  1991年   10篇
  1990年   7篇
  1989年   13篇
  1988年   3篇
  1987年   9篇
  1986年   10篇
  1985年   7篇
  1984年   3篇
  1983年   3篇
  1982年   4篇
  1980年   4篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1973年   1篇
  1970年   1篇
  1968年   1篇
  1933年   1篇
排序方式: 共有2410条查询结果,搜索用时 296 毫秒
101.
OBJECTIVES: To introduce a useful technique for identifying any collateral veins during laparoscopic varicocele operation and to evaluate our long-term results with this technique after 100 cases. METHODS: A new method was used to detect an incidental collateral vein. During surgery the patient was placed in anti-Trendelenburg position after introducing laparoscopic instruments until the dilated scrotal varicose filled up with blood. The main spermatic vein was then grasped atraumatically and the blood was pressed out manually from the scrotum. During this manoeuvre any existing collateral vein/veins became dilated and could be easily identified. The dilated spermatic vein and also any collateral vessel were first prepared then clipped. RESULTS: Out of the 100 patients, collateral veins were detected and ligated in 19 cases. In 15 cases a single collateral, in 4 cases two collaterals, and in the remaining 81 children no collateral veins were found. The testicular artery was identified in all operations as a pulsatile vessel. At a mean of 24 months (range 6-60 months) follow-up recurrence occurred in one patient and in five children hydrocele developed postoperatively. Testicular atrophy and severe intra- or postoperative complication did not occur in any patient of this series. CONCLUSION: The identification of incidental collateral vein by this method and preservation of the testicular artery resulted in a very good success rate in children and adolescents treated by laparoscopic varicocele operation.  相似文献   
102.
Using a special software program we measured spinopelvic parameters on digitised radiographs of the entire spine and the pelvis of 50 patients with lumbar disc herniation and compared these with the same measurements on 30 healthy subjects. In the disc hernia group the patients had a relatively straight spine in the sagittal plane. The sacrum was more vertical, and the value of the lumbar lordosis was lower, as was the amplitude of the spinal curvatures, when compared with those of the healthy group. This results in a higher gravitational compressive force which may, in turn, lead to progressive degeneration of the discs. The anterior shift of the line of gravity may cause spinopelvic instability, and contraction of the posterior spinal muscles in trying to balance this disturbed spatial relationship may produce back pain.  相似文献   
103.
PURPOSE: To detect tear film regularity changes in the 15 seconds after a blink, by using a new high-speed videotopographic method. METHODS: The new system, based on a standard corneal topograph, allows registration of four photokeratoscopic images per second. Altogether, 15 eyes of 15 healthy volunteers and 7 eyes of 7 patients with dry eye were examined in this prospective preliminary study. The main outcome measures were changes in surface regularity index (SRI), surface asymmetry index (SAI), and corneal power. RESULTS: The corneal surface became more regular in the first few seconds after a blink. In healthy eyes, the trend line of SRI and SAI decreased (improved) significantly (P < 0.001) after a blink, in 10 of 15 eyes for the SRI and in 13 of 15 for the SAI. In the typical cases, the trend line for SRI reached its minimum level, on average, at 7.1 +/- 3.9 seconds after a blink and that for the SAI at 5.4 +/- 2.7 seconds. Similar trends were found in the dry-eye group. The changes in keratometric measures were small (mean range, <1.5% of the absolute value) and showed no definite trends. CONCLUSIONS: High-speed videotopography provides the possibility of quantitative measurement of tear-film dynamics and may have clinical value in the management of ocular surface disorders. After a blink, it takes the tear film approximately 3 to 10 seconds (tear film build-up time) to reach the most regular state. However, despite surface-regularity changes, the measured corneal powers are stable.  相似文献   
104.
New trends in the development of oral antidiabetic drugs   总被引:2,自引:0,他引:2  
A large number of oral antidiabetic agents are available today. This article provides a short review of the pharmacology and some clinical aspects of various oral antidiabetic drugs. It focuses mainly on the newest developing drugs (therapy of the near future) and on the most commonly used older groups for the common approach of every-day practice (sulphonylureas). The primary goal of this review is to compare the electrophysiological effects of glibenclamide in isolated normal and streptozotocin induced diabetic rats and alloxan induced rabbits ventricular preparations, while on the other hand to differentiate the hypoglycaemic sulphonylureas (0.1-1000 mmol/kg) according to their cardiovascular activity in healthy and diabetic animals. In vitro (1-100 micromol/l) as well as chronically treated (5 mg/kg for 10 weeks) glibenclamide prolonged the action potential duration in normal but failed to affect it in diabetic ventricular preparations. Our results suggest that the sensitivity to glibenclamide of K(ATP) channels in diabetic ventricular fibers is drastically decreased. The effects of different sulphonylureas (tolbutamide, glibenclamide, gliclazide, glimepiride) on ventricular ectopic beats as well as the duration of ventricular fibrillation induced by 10 min ischemia/50 min reperfusion in healthy and diabetic rats were compared. Tolbutamide and gliclazide dose-dependently enhanced both parameters both in healthy and diabetic groups. Glibenclamide in healthy rats increased, while in diabetic rats it decreased the arrhythmogenicity. Glimepiride depressed the arrhythmogenicity in both healthy and diabetic animals. Glimepiride proved to dose-dependently enhance the myocardial tissue flow in dog in contrast to glibenclamide. These results confirm that glimepiride has less cardiovascular actions than other sulphonylureas. From the newest oral antidiabetics this review tries to emphasize the most important basic pharmacological properties, mechanism of action, therapeutic use.  相似文献   
105.
106.
A new method has been developed to investigate corticostriatal glutamatergic influence on [3H]dopamine release in striatum in complex corticostriatal slice preparation in vitro. Horizontal slices containing the striatum and the adjacent prefrontal cortex of rat brain were cut in a plane that maintains corticostriatal connections. After incubation with [3H]dopamine, slices were submerged in a two-compartment bath so that the cortical region was contained entirely in one compartment, corpus callosum passed through a silicone greased slot, and the striatal region was contained in the other compartment. A cannula was placed just above the striatal part of the slice and effluent was collected with a peristaltic pump, released tritiated materials were counted with a liquid scintillation counter. Electric field stimulation of cortex increased the release of [3H]dopamine in the striatum. Bicuculline (1 mM) increased the basal and stimulated release of [3H]dopamine in the striatum in response to cortical stimulation of cortex indicating the GABAergic control on dopamine release. This method allows investigation of the effect of cortical stimulation on glutamate-dopamine-GABA interactions in the striatum in vitro that might help to understand better the neurochemical background of schizophrenia or Parkinson's disease.  相似文献   
107.
Balogh Z  Wolfárd A  Szalay L  Orosz E  Simonka JA  Boros M 《The Journal of trauma》2002,52(6):1062-9; discussion 1070
BACKGROUND: Ischemia/reperfusion-induced polymorphonuclear neutrophil leukocyte (PMN) adhesion and extravasation are pivotal for the development of postinjury multiple organ failure. We hypothesized that the deleterious microcirculatory consequences of hemorrhagic shock (HS) could be altered by low-molecular-weight heparin (LMWH) therapy. Our aim was to investigate the effects of dalteparin sodium on leukocyte-endothelial cell interactions when LMWH treatment was initiated before HS or during resuscitation. METHODS: Anesthetized dogs underwent HS (40 mm Hg mean arterial pressure for 60 minutes) and resuscitation either with shed blood or with lactated Ringer's (LR) solution. LMWH or conventional heparin sodium pretreatment was administered subcutaneously before hemorrhage; or LMWH was given intravenously during resuscitation. Mesenteric postcapillary venules were observed by intravital video microscopy before and after HS, and 60 minutes, 120 minutes, and 180 minutes after resuscitation, and leukocyte rolling and firm adherence were determined. RESULTS: HS significantly increased PMN rolling and adhesion in the mesenteric microcirculation. LMWH, but not heparin sodium pretreatment, significantly inhibited both primary and secondary interactions. LMWH treatment was also effective when initiated during resuscitation. LMWH exerted the same inhibitory effect regardless of the type of resuscitation. CONCLUSION: LMWH treatment during resuscitation effectively inhibits PMN rolling and adhesion.  相似文献   
108.
We performed cervical oesophageal anastomosis in 153 patients in 10 years. In 11 patients reconstruction or delayed anastomosis was performed through median sternotomy because cervical approach was not suitable. Reoperations were the following: 7 oesophageal stenosis which couldn't be dilated, 2 necrosis of the transplanted organ and 2 because of delayed anastomosis. 8 patients had oesophageal tumors and 3 erosive fluid reflux. During median sternotomy the transplanted organ was injured twice. In 9 patients after reconstruction dysphagia disappeared, in one pharyngo-ileostomy stenosis was noticed and one of the patients died because of ARDS after a leak.  相似文献   
109.
The rarity of cloacal anomalies, the wide range of anatomical variants, and the number of different operations mean that successful management of a patient (neonate or child) with this condition is one of the greatest challenges for paediatric surgeons. The authors describe the complex corrections of 3 patients with cloacal malformation (age 10-13 years). The cloacal malformations were not diagnosed at neonatal age and therefore only the anorectal agenesis was corrected at the first stage. The authors strongly recommend that all components of this anomaly (urethra, vagina and anorectum) should be managed in one step. Because of the rarity and complexity of cloacal malformations, the anomaly should be operated on only in specialised centres.  相似文献   
110.
INTRODUCTION: The screening mammography decreases the mortality of female breast cancer. METHODS: A complex, independent centre of screening mammography has been operating in Debrecen since 1999. RESULTS: The number of the examinations were 10,399 in 1999 and 13,800 in 2000. The number of explored breast cancer cases were 43 (0.41%) in 1999 and 62 (0.45%) in 2000. CONCLUSION: Although the mortality reduction can be exactly measured after several years, we are convinced that the chances for a better life of these 107 women operated on with breast cancer in early state increased thanks to our project. The results of the breast cancer screening program in Debrecen fulfilled the professional requirements of mammographic service-screening.  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