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   413篇
  免费   17篇
  国内免费   4篇
儿科学   11篇
妇产科学   2篇
基础医学   19篇
口腔科学   13篇
临床医学   30篇
内科学   136篇
皮肤病学   1篇
神经病学   8篇
特种医学   91篇
外科学   30篇
综合类   19篇
预防医学   26篇
眼科学   2篇
药学   24篇
肿瘤学   22篇
  2021年   7篇
  2020年   4篇
  2019年   4篇
  2018年   8篇
  2017年   4篇
  2016年   6篇
  2015年   15篇
  2014年   7篇
  2013年   21篇
  2012年   17篇
  2011年   9篇
  2010年   19篇
  2009年   10篇
  2008年   11篇
  2007年   12篇
  2006年   11篇
  2005年   7篇
  2004年   11篇
  2003年   8篇
  2002年   5篇
  2001年   9篇
  2000年   10篇
  1999年   8篇
  1998年   21篇
  1997年   21篇
  1996年   16篇
  1995年   15篇
  1994年   16篇
  1993年   11篇
  1992年   3篇
  1991年   7篇
  1990年   9篇
  1989年   12篇
  1988年   7篇
  1987年   5篇
  1986年   8篇
  1985年   5篇
  1984年   6篇
  1982年   4篇
  1981年   5篇
  1980年   8篇
  1978年   5篇
  1977年   5篇
  1976年   3篇
  1975年   4篇
  1973年   2篇
  1968年   2篇
  1958年   2篇
  1954年   2篇
  1953年   2篇
排序方式: 共有434条查询结果,搜索用时 46 毫秒
61.
Esophageal dysmotility is common in patients with Barrett's esophagus. Previously we have reported deterioration of esophageal motility after photodynamic therapy (PDT) in a heterogeneous group of patients with esophageal carcinoma. This prospective study in consecutive patients describes changes in motility noted after endoscopic ablation. Forty-seven patients referred to our institution for endoscopic ablation for Barrett's high grade dysplasia or mucosal carcinoma between August 2001 and May 2003 were prospectively evaluated with esophageal manometry before and after porfimer sodium PDT. Six patients did not complete the study. Manometry results were classified as normal, diffuse esophageal spasm, ineffective esophageal motility, or aperistalsis. Abnormal esophageal motility was found in 14 of 47 (30%) patients at study entry ([diffuse esophageal spasm] DES-3, [ineffective esophageal motility] IEM-7, Aperistalsis-4). After PDT, 11 of 41 patients with paired studies experienced a change in manometric diagnosis. Three patients had an improvement in motility, seven a worsening and one changed diagnosis, but did not particularly worsen or improve. No patient developed new aperistalsis. Therefore, abnormal motility was present in 19 of 41 (46%) patients after PDT (DES-2, IEM-14, Aperistalsis-3). There was a statistically significant (P = 0.016) relationship with longer segment Barrett's esophagus and deterioration of function. Baseline abnormalities in motility can occur in patients with Barrett's high-grade dysplasia or mucosal carcinoma. Changes in esophageal function also may occur following photodynamic therapy, but usually are not clinically significant. Worsening in function was more likely to occur in patients with longer segment Barrett's esophagus.  相似文献   
62.
Objective: Gruded intraesophaKeal balloon distention has been suggested as a provocative test in the assessment of undetermined chest pain. Balloon distention was used to determine pain threshold reproducibility for 20 normal individuals (mean age: 27 yr). Methods: Balloons made of silicone and latex were each evaluated in 10 subjects, with the balloon located 10 cm above the lower esophageal sphincter. The balloons were sequentially inflated with 2-cc increments of air by a specially designed pump to a total volumeof 2 cc above the level of pain for each subject.A random series of inflations was alsoused. Three sets of both sequential (S) and random (R) inflations were performed on 2 subsequent days. Results: With the silicone balloon, the mean volume for pain thresholdwas 15 ± I.I cc (±SE) for S and 15 ± 1.2 cc for R inflations on day 1 and 15 ± 1.5 cc and 15 ± 1.5 cc on day 2. For the latex balloons, the mean volume for pain threshold was17 ± 1.4 cc for S and 17 ± 1.4 cc for R inflations on day 1 and 17 ± 1.6 cc and 18 ± 1.9 cc on day 2. Conclusion: From these studies, we conclude that pain thresholds to esophageal balloon distention are reproducible with same or subsequent day testing. Similareffects occur with either silicone or latex balloons. In vitro studies on the inflationcharacteristics of the balloons indicate that the latex balloon inflates in a more even, linear manner, which makes this balloon more practical for evaluating pain thresholdsin terms of air volume inflations.  相似文献   
63.
To investigate the role of central neurotransmitters in the pathogenesis of migraine, we measured cerebrospinal fluid (CSF) levels of certain amino acids (glycine, taurine, glutamine) and metabolites of biogenic amines (5-hydroxyindoleacetic acid and homovanillic acid) in 38 migraine patients and compared them with the levels from 10 headache-free controls. The levels of taurine, glycine and glutamine were significantly higher in the migraine patients (p < 0.0001 for taurine and glycine; p < 0.0009 for glutamine); there were no significant differences among the three migraine subgroups (infrequent migraine, frequent migraine and transformed migraine). In seven patients subsequently treated with divalproex sodium, CSF taurine levels decreased significantly from pretreatment baseline values. These data support the concept that migraine is at least in part a disorder of central neurotransmission.  相似文献   
64.
abstract — The purpose of the present study was to investigate whether some dental filling materials collect more plaque than others under standardized conditions in vitro and in vivo . Round disks of the filling materials of silicate, composite and amalgam were prepared and placed on an agar/sucrose medium or hung in liquid medium containing 5% sucrose. The mediae were inoculated with Streptococcus mutans OMZ 176 and OMZ 52–3. After 6 d the disks were rinsed in distilled water and the plaque that had accumulated on the surfaces was scraped off and measured by the orcinol method. The materials were also fitted to acrylic plates and introduced into the mouth. Six patients wore two plates each for comparison of the materials and were told to rinse their mouth every hour with 15% sucrose solution. After 8 h the plaque was scraped off and measured. Silicate disks on agar medium invariably produced inhibition zones of about 4 mm. Composites and amalgam showed no such zones. In liquid medium an insignificant amount of plaque was absorbed to the silicate disks, whereas abundant amounts were found on composite materials and some on amalgam disks. The same trend could be demonstrated in the clinical experiments.  相似文献   
65.
66.
67.
68.
Tube-based ambulatory pH testing has rapidly evolved in the past 3 decades to become the standard by which other diagnostic approaches to gastroesophageal reflux disease are judged. Acid exposure 5 cm above the manometrically determined lower esophageal sphincter is the standard for documentation of pathologic acid exposure of the distal esophagus. Proximal esophageal or hypopharyngeal monitoring is an evolving technique that may shed light on patients with supraesophageal symptoms. The ability to simultaneously monitor esophageal and gastric acidity (usually in patients with persistent symptoms despite therapy) is another advantage of this technique. Whether the new system that allows simultaneous pH and impedance monitoring and the system that uses an implantable tubeless monitoring capsule will supplant this older but well-established technology remains to be determined.  相似文献   
69.
70.
Diagnosing gastroesophageal reflux disease   总被引:6,自引:0,他引:6  
Gastroesophageal reflux disease (GERD) is a common condition with a variety of clinical manifestations and potentially serious complications. This article reviews available methods for diagnosing GERD. A clinical history of the classic symptoms of GERD, heartburn or acid regurgitation, is sensitive enough to establish the diagnosis in patients without other complications. Esophagogastroduodenoscopy is the best way to evaluate suspected complications of GERD, but endoscopic findings are insensitive for the presence of pathological reflux, and therefore they cannot reliably exclude GERD. The "gold standard" study for confirming or excluding the presence of abnormal gastroesophageal reflux is the 24-hour ambulatory esophageal pH monitoring test, and this study should be used for the evaluation of refractory symptoms and extraesophageal manifestations of GERD. A formal acid-suppression test is helpful in the evaluation of the atypical GERD symptom of noncardiac chest pain. Optimal use of currently available tests for GERD may allow for more efficient diagnosis and better characterization of the pathological manifestations associated with GERD.  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