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   489篇
  免费   11篇
  国内免费   2篇
耳鼻咽喉   25篇
儿科学   44篇
妇产科学   27篇
基础医学   31篇
口腔科学   9篇
临床医学   39篇
内科学   71篇
皮肤病学   5篇
神经病学   33篇
特种医学   27篇
外科学   83篇
综合类   9篇
预防医学   9篇
眼科学   53篇
药学   14篇
肿瘤学   23篇
  2022年   6篇
  2021年   9篇
  2020年   5篇
  2019年   7篇
  2018年   4篇
  2017年   3篇
  2016年   14篇
  2015年   18篇
  2014年   23篇
  2013年   27篇
  2012年   45篇
  2011年   38篇
  2010年   21篇
  2009年   9篇
  2008年   17篇
  2007年   37篇
  2006年   28篇
  2005年   45篇
  2004年   47篇
  2003年   47篇
  2002年   28篇
  2001年   5篇
  2000年   4篇
  1999年   6篇
  1998年   3篇
  1997年   2篇
  1995年   1篇
  1994年   1篇
  1992年   1篇
  1986年   1篇
排序方式: 共有502条查询结果,搜索用时 15 毫秒
31.
32.
BACKGROUND: Iatrogenic factors became the leading mechanisms of severe cholangitis in a referral center. PATIENTS AND METHODS: The records of the 58 patients treated for severe cholangitis between 1996 and May 2004 (inclusive) were evaluated. RESULTS: The most frequent underlying diseases were periampullary tumors and mid-bile duct carcinomas (22), followed by proximal cholangiocarcinomas (14). The triggering mechanism was an incomplete endoscopic retrograde cholangiopancreatography (ERCP) in 32 patients, incomplete or inappropriate percutaneous transhepatic biliary drainage (PTBD) in 6, apparently successful ERCP and stenting in 1, and percutaneous transhepatic cholangiography in 1. PTBD was the treatment of choice (38). Mortality was 29% (17/58); the major causes were refractory sepsis (8) and incomplete biliary drainage (advanced tumor, technical failure, or hemobilia) (8). CONCLUSIONS: In this series composed predominantly of patients referred after development of sepsis, ERCP and PTBD complications were the leading mechanisms of severe cholangitis. Nonoperative biliary manipulations are invasive procedures with potentially fatal complications. The decisions to perform such procedures and periprocedural management are responsibilities of an experienced multidisciplinary team.  相似文献   
33.
34.
To evaluate valvular stenosis, cardiac dilation, and/or cardiac hypertrophy, measurements of valve circumference and ventricular wall thickness are of importance. To establish reference values in fetuses and neonates, we reviewed pathology reports at Women and Infants Hospital from 1978 through 2002 and found measurements in 776 cases that were suitable for analysis. Gestational ages (GA) ranged from 15 to 42 wk. The tabulated data include the mean, standard deviation, and 10th and 90th percentile values for foot length, body weight, body length, heart weight, valve measurements, and ventricular wall thicknesses for each week of GA. In cases in which clinical dating is not reliable, we estimated the GA by the mean value nearest that of the observed foot length. All linear measurements increased in a linear fashion throughout the second and third trimesters of development. The circumferences of cardiac valves at all ages, in descending order of magnitude, are: tricuspid, mitral, pulmonary, and aortic. Mean left ventricular (LV) wall thickness is greater than mean right ventricular (RV) wall thickness throughout gestation. The tables offer a means of determining valvular stenosis, or cardiac dilation and/or hypertrophy, based on various gestational ages.  相似文献   
35.
OBJECTIVE: To evaluate by computed tomographic scanning the paranasal mucosal changes of coal workers with and without pneumoconiosis. METHODS: Examination of images and scores from paranasal computed tomographic scans. The study participants were 26 coal workers with pneumoconiosis, 29 coal workers without pneumoconiosis, and 20 controls. All were men. The extent and patterns of inflammatory paranasal sinus disease were evaluated on computed tomographic scans by 2 radiologists using the terminology and definitions of Newman and associates. RESULTS: Interobserver agreement for the presence of abnormalities was from good to excellent (kappa, 0.63-0.89). The mucosal scores of individuals and groups were higher for coal workers than for control subjects. Both scores were significantly higher in the pneumoconiosis group than in the 2 other groups. CONCLUSIONS: This study shows that paranasal sinuses were affected more severely in coal workers than in control subjects. In coal workers with pneumoconiosis, the affection was most severe. The relationship between coal dust exposure and paranasal mucosal changes needs further study.  相似文献   
36.
37.
OBJECTIVE: Adjunctive tests are needed to predict sepsis in the newborn and to lower the rate or duration of unnecessary antibiotic use. We evaluated the normal Inter-alpha inhibitor protein (IaIp) values in infants and the association of plasma levels of IaIp with sepsis in term and preterm newborns. METHODS: Plasma IaIp levels were measured by enzyme-linked immunosorbent assay in samples from 135 newborn infants at a wide range of gestational ages (24-42 weeks). IaIp levels were also determined in 19 infants undergoing prospective evaluation for sepsis. RESULTS: IaIp levels in umbilical cord blood and circulating peripheral blood of healthy newborn infants (525+/-66 mg/L) were not significantly different from the level in healthy adults (691+/-80 mg/L). IaIp levels were similar in infants between 24 and 42 weeks gestational age. There was a significant reduction in IaIp levels in infants with sepsis compared with nonseptic controls (169+/-126 mg/L vs 613+/-286 mg/L, P<.0001). CONCLUSIONS: IaIp levels in the blood of newborns are independent of gestational age and similar to adults. IaIp levels are significantly reduced in infants with bacterial sepsis and might serve as an adjunctive diagnostic marker to allow prospective reduction of antibiotic use.  相似文献   
38.
OBJECTIVE: The aim of the study was to determine the role of perineal sonography in diagnosis of stress urinary incontinence. MATERIALS AND METHODS: Thirty patients with stress urinary incontinence and 17 age-matched control patients were included in the study. Perineal sonography was carried out in both groups to evaluate the role of this technique in the diagnosis of stress urinary incontinence. By using the posterior edge of the symphysis pubis as a reference point, posterior urethra-vesical angle (beta angle) and the angle between the vertical axis and urethral axis(alpha angle) were measured at rest and on straining. Bladder neck mobility was evaluated only at the cephalocaudal plane by measuring the desensus diameter. RESULTS: Posterior urethro-vesical angle (beta angle) was found to be significantly different between the study and control groups both at rest and on straining (P < 0.05). The angle between the vertical axis and urethral axis (alpha angle) was found to be significantly different between study and control groups only on straining (P < 0.05). Cephalocaudal distance (desensus diameter) was longer in patients with stress urinary incontinence (P < 0.05). CONCLUSION: Perineal sonography has an important role in diagnosing patients with stress urinary incontinence.  相似文献   
39.
Two patients with partial deletions of the long arm of chromosome 13, del(13)(13q21-q34) and del(13)(13q22-q33), respectively, multiple congenital anomalies including holoprosencephaly (HPE) and the Dandy-Walker malformation (DWM) are described. The occurrence of HPE and the DWM in both of these patients suggests that, in addition to ZIC2, which is important for normal development of the forebrain, there is at least one other dosage-sensitive gene in 13q22-q33 that plays an important role in brain development. The DWM is anatomically and developmentally distinct from HPE. The presence of a DWM in each of these two patients with partial deletions of the long arm of chromosome 13 suggests that haploinsufficiency at a locus in 13q22-q33 may cause this anomaly. These findings suggest that microdeletions in 13q22-q33 may be found in a proportion of patients with an apparently isolated DWM. Therefore, careful high-resolution cytogenetic analysis (550 band level or greater) of 13q22-q33 may be considered in these patients. Furthermore, future molecular studies of this region may reveal candidate gene loci for the DWM.  相似文献   
40.
A 9-year-old girl with osteogenesis imperfecta (OI) type 4 was admitted to the hospital because of choreatic movement. Cerebral angiography demonstrated bilateral symmetrical stenosis of the proximal cavernous segment of internal carotid artery, prethrombotic occlusion of the M1 segment of left middle cerebral artery, and moyamoya-like collateral vascular structure arising from the right lenticulostriate arteries. After a literature review, these findings were interpreted as vasculopathic changes secondary to vascular fragility caused by the collagen abnormality in OI.  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