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   1990篇
  免费   221篇
  国内免费   34篇
耳鼻咽喉   5篇
儿科学   74篇
妇产科学   103篇
基础医学   287篇
口腔科学   24篇
临床医学   180篇
内科学   466篇
皮肤病学   13篇
神经病学   131篇
特种医学   201篇
外科学   217篇
综合类   43篇
一般理论   1篇
预防医学   81篇
眼科学   29篇
药学   149篇
中国医学   14篇
肿瘤学   227篇
  2023年   7篇
  2022年   15篇
  2021年   26篇
  2020年   22篇
  2019年   28篇
  2018年   38篇
  2017年   35篇
  2016年   30篇
  2015年   57篇
  2014年   69篇
  2013年   75篇
  2012年   127篇
  2011年   125篇
  2010年   90篇
  2009年   88篇
  2008年   99篇
  2007年   99篇
  2006年   85篇
  2005年   92篇
  2004年   97篇
  2003年   80篇
  2002年   72篇
  2001年   63篇
  2000年   64篇
  1999年   69篇
  1998年   34篇
  1997年   39篇
  1996年   44篇
  1995年   35篇
  1994年   26篇
  1993年   24篇
  1992年   31篇
  1991年   29篇
  1990年   38篇
  1989年   36篇
  1988年   33篇
  1987年   33篇
  1986年   21篇
  1985年   22篇
  1984年   21篇
  1983年   16篇
  1982年   13篇
  1981年   17篇
  1980年   10篇
  1979年   13篇
  1978年   12篇
  1977年   16篇
  1976年   8篇
  1972年   5篇
  1971年   4篇
排序方式: 共有2245条查询结果,搜索用时 0 毫秒
121.
The optimal surgical management of stress incontinence in women remains a contentious issue. Retropubic urethropexies such as the Burch procedure are regarded as having excellent long-term success rates. The learning curve for transvaginal tape procedures is by far shorter and easier than for the laparoscopic Burch procedure. Data from the few randomized trials published thus far show that both procedures are associated with high success rates and patient satisfaction.  相似文献   
122.

Background

Patients undergoing operative repair of aortic obstruction are at a lifelong risk of recurrent obstruction, and there is controversy regarding the optimal surgical technique. We have used an alternative strategy for recurrent aortic obstruction, typically involving anatomic reconstruction by means of a median sternotomy, and describe our techniques and results.

Methods

Twenty-one patients presented with recurrent aortic arch obstruction. Mean age and weight were 7.8 ± 5.4 years (range, 0.21 to 15.2 years) and 30.6 ± 21.8 kg (range, 3.6 to 90 kg), respectively. Recurrence involved the aortic arch to some degree in each case, as the mean preoperative transverse aortic arch z score was −2.9 ± 1.6 (range, −7.0 to 0.1). Thoracotomy was possible in 2 patients, using re-resection with end-to-end anastomosis (n = 1) and patch aortoplasty (n = 1). The remaining 19 patients required median sternotomy, cardiopulmonary bypass, and deep hypothermic circulatory arrest for complete relief of obstruction by aortic arch advancement (n = 10), patch aortoplasty (n = 8), or interposition grafting (n = 1).

Results

There was 1 hospital death. Invasive blood pressure monitoring revealed no residual arm-to-leg gradient in 19 patients and a 20-mm Hg gradient in 2 patients. There have been no late deaths. No patients have undergone subsequent aortic intervention, and all are asymptomatic up to 85 months postoperatively. Two patients are currently followed with a 10-mm Hg arm-to-leg blood pressure gradient.

Conclusions

Anatomic reconstruction for recurrent aortic obstruction can be safely accomplished in the majority of patients. We favor median sternotomy because of the ability of establishing cardiopulmonary bypass, the facility of anatomic reconstruction techniques, and the ability to repair concomitant cardiovascular lesions.  相似文献   
123.
HYPOTHESIS: With the introduction of the blood chemistry multichannel autoanalyzer, primary hyperparathyroidism (HPT) is increasingly diagnosed. The clinical pattern of primary HPT has undergone a significant evolution in Western countries. A similar change can be documented in a geographic region where this condition is considered to be relatively uncommon. DESIGN: Unselected case series. SETTING: A tertiary referral endocrine surgical unit. PATIENTS: All patients with primary HPT surgically treated over the past 30 years. MAIN OUTCOME MEASURES: The prevalence of patients per 100,000 hospital admissions, clinical presentation, biochemistry study results, pathologic status, and main outcome were compared over three 10-year spans according to the introduction of the multichannel autoanalyzer in 1982: 1973-1982 (n = 20), 1983-1992 (n = 31), and 1993-2002 (n = 190). RESULTS: A 7-fold increase in the prevalence of patients with primary HPT who were surgically treated per 100,000 hospital admissions was observed over the past 10 years. The clinical presentation of patients with primary HPT had evolved progressively with a higher proportion of older patients (P<.001) being asymptomatic. On presentation, the condition had decreased in severity with lower serum calcium (P =.04), parathyroid hormone (P<.001), and alkaline phosphatase levels (P<.001) as well as a smaller adenoma size (P<.001). There was no significant change in the underlying pathologic condition and surgical success. CONCLUSION: Similar to the West but in contrast to that observed in other Asian countries, an increase in the prevalence of patients surgically treated for primary HPT is documented and a change in disease presentation as well as its severity is observed in our population group.  相似文献   
124.
125.
126.
127.
Bronchial shunt flows in the recipients of the electrohydraulic AbioCor implantable replacement heart have been measured indirectly. A built-in compliance chamber accommodates the differential flow output required of the two ventricles of the AbioCor. An occluder mechanism regulates the flow differential. For a thoracic unit, given a beat rate, an occluder setting, and the pressure differentials across the replacement heart ventricles, the atrial pressure difference depends only on the level of shunt flow present in the vasculature. For a replacement heart recipient, the bronchial shunt is the dominant shunt flow. For patients implanted with the AbioCor, the beat rates and the occluder settings are known and the pressure differentials across the ventricles are estimated. Atrial pressures were measured using catheters. The bronchial shunt flow was deduced from in vitro characterization data based on these parameters. Available data from five patients in the ongoing clinical trial of AbioCor showed 0-1.4 L/minute bronchial shunt flows. Maximum variation for any individual patient was 1.1 L/minute.  相似文献   
128.
Clozapine-associated induction of venous thromboembolism has potentially catastrophic consequences. We report a case of sudden death caused by bilateral main pulmonary trunk thrombosis in a 31-year-old man receiving clozapine therapy. The patient presented with general weakness and exertional dyspnea. Bilateral main pulmonary trunk thrombosis was clearly demonstrated by helical chest computed tomography.  相似文献   
129.
Imaging serotonin transporters (SERT) is an emerging research tool potentially useful to cast light on the mechanisms of drug action as well as to monitor the treatment of depressed patients. We have prepared two new derivatives of 3, 2-(2-(dimethylaminomethyl)phenoxy)-5-iodophenylamine (4) and 2-(2-(dimethylaminomethyl)benzyl)-5-iodophenylamine (5) (K(i) for SERT = 0.37 and 48.6 nM, respectively). Both [(125)I]4 and [(125)I]5 displayed excellent brain uptakes in rats, and they showed a highest uptake in hypothalamus (between 60 and 240 min), a region populated with the highest density of SERT. The specific uptake of [(125)I]4 in the hypothalamus resulted in a target to nontarget ratio ([hypothalamus-cerebellum]/cerebellum) of 4.3 at 2 h. Autoradiography of rat brain sections (ex vivo at 2 h) of [(125)I]4 showed an excellent regional distribution pattern consistent with known SERT localization. These data suggest that [(123)I]4 may be useful for imaging SERT binding sites in the brain by single photon emission computed tomography (SPECT).  相似文献   
130.
Kung AW 《Clinical calcium》2004,14(9):108-111
Osteoporosis is among the top 3 medical conditions that are associated with greatest morbidity and reduction of quality of life of Hong Kong elderly subjects. The genetic and environmental risk factors for osteoporosis in southern Chinese as well as the current approach towards managing this growing health problem in Hong Kong are presented.  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