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   384篇
  免费   77篇
  国内免费   1篇
耳鼻咽喉   3篇
儿科学   17篇
妇产科学   7篇
基础医学   36篇
口腔科学   6篇
临床医学   35篇
内科学   103篇
神经病学   68篇
特种医学   2篇
外科学   33篇
综合类   6篇
预防医学   115篇
眼科学   2篇
药学   10篇
肿瘤学   19篇
  2022年   4篇
  2021年   7篇
  2020年   6篇
  2019年   5篇
  2018年   5篇
  2017年   11篇
  2016年   13篇
  2015年   7篇
  2014年   6篇
  2013年   20篇
  2012年   19篇
  2011年   26篇
  2010年   6篇
  2009年   5篇
  2008年   15篇
  2007年   14篇
  2006年   14篇
  2005年   12篇
  2004年   15篇
  2003年   11篇
  2002年   5篇
  2001年   7篇
  2000年   6篇
  1998年   3篇
  1996年   8篇
  1995年   3篇
  1993年   5篇
  1992年   9篇
  1991年   8篇
  1990年   17篇
  1989年   12篇
  1988年   19篇
  1987年   13篇
  1986年   8篇
  1985年   13篇
  1984年   6篇
  1983年   9篇
  1982年   3篇
  1980年   5篇
  1979年   11篇
  1978年   4篇
  1976年   6篇
  1975年   6篇
  1974年   13篇
  1973年   6篇
  1972年   6篇
  1971年   3篇
  1970年   5篇
  1967年   6篇
  1959年   2篇
排序方式: 共有462条查询结果,搜索用时 62 毫秒
1.
Certain groups of patients requiring enteral nutritional support are at increased risk of regurgitation and pulmonary aspiration of feed. Positioning of enteral feeding tubes distal to the pylorus has been advocated as a method of reducing such complications. Various techniques have been suggested to achieve postpyloric siting. Reports have indicated that lengthening the tube or altering the distal end tip configuration, by varying the tip profile or by the addition of a weight, may facilitate spontaneous transpyloric passage of the tube. This prospective controlled clinical study using three new polyurethane tubes demonstrates that the frequency of spontaneous transpyloric passage of the tube is not affected by tip profile or by the addition of a weight. Indeed, with all three tube designs only about one-third had passed spontaneously through the pylorus at 24 hr. Once through the pylorus the unweighted tube stayed in position significantly longer than the weighted tubes (p less than 0.005). We suggest that in those patients requiring post-pyloric feeding, endoscopic or fluoroscopic techniques should be used to position the tubes at the time of insertion, and that an unweighted tube should be used to prolong tube usage.  相似文献   
2.
We have reviewed and discussed data concerning the development of hepatobiliary dysfunction in the patient requiring TPN. The data above can be summarised in a short statement--TPN-related hepatobiliary dysfunction is multifactorial. Despite all the factors discussed, the patients underlying disease state and the severity of the illness may be the most significant factor in the development of hepatobiliary dysfunction. With our current state of knowledge it is only possible for the clinician to be aware which of his patients are most likely to develop problems, and to forecast the type of dysfunction that is most likely to occur. There is no treatment--apart from stopping TPN--but there are certain methods by which the incidence and degree of dysfunction may be minimised, or some of the complications (e.g. gallstones) treated. Fortunately in most cases the degree of dysfunction is both self-limiting and reversible on cessation of TPN.  相似文献   
3.
Notifiable disease surveillance systems provide essential data for infectious disease prevention and control programs at the local, state, and national levels. Given that reporting completeness is known to vary considerably, this review identifies methods that can reliably enhance completeness of reporting. These surveillance-related activities include initiating active surveillance when appropriate; implementing automated, electronic laboratory-based reporting; strengthening ties with clinicians and other key partners in notifiable disease reporting; and increasing the use of laboratory diagnostic tests in identifying new cases. Despite ample data in support of these strategies, notifiable disease surveillance continues to receive insufficient attention and resources. Recent attention to public health preparedness provides an opportunity to strengthen notifiable disease surveillance and enhance completeness of reporting.  相似文献   
4.
5.
A method is described for the colorimetric determination of fenitrothion spray deposit on conifer foliage. The technique is suitable for rapid deposit determination in the field using a portable mini-spectrophotometer. The detection limit is approximately 0.5 g fenitrothion/g foliage, although this could be improved. The technique is used in conjunction with gas chromatography to examine the evaporation and absorption dynamics of fenitrothion deposits on balsam fir foliage.  相似文献   
6.
Eleven "pure" borderlines, ten borderlines with depression, 16 "pure" depressives, and 31 normal subjects were compared on a number of standardized inventories of anxiety. While patient groups experienced more anxiety of all types than did normals, borderlines did not emerge as more anxious than other patient groups. Qualitative differences in the anxiety experienced by borderlines and nonborderlines are discussed.  相似文献   
7.
Hydrolysis of peptides within lumen of small intestine   总被引:2,自引:0,他引:2  
  相似文献   
8.
Sleep disturbance is prevalent in anxious youth and prospectively predicts poor emotional adjustment in adolescence. Study 1 examined whether anxiety treatment improves subjective and objective sleep disturbance in anxious youth. Study 2 examined whether a sleep intervention called Sleeping TIGERS can further improve sleep following anxiety treatment. Study 1 examined 133 youth (ages 9–14; 56% female; 11% ethnic/racial minority) with generalized, social, or separation anxiety over the course of anxiety treatment (cognitive behavioral treatment or client-centered treatment). Sleep-related problems (parent-, child-report) and subjective (diary) and objective (actigraphy) sleep patterns were assessed across treatment in an open trial design. Study 2 included 50 youth (ages 9–14; 68% female; 10% ethnic/racial minority) who continued to report sleep-related problems after anxiety treatment and enrolled in an open trial of Sleeping TIGERS. Pre- and postassessments duplicated Study 1 and included the Focal Interview of Sleep to assess sleep disturbance. Study 1 demonstrated small reductions in sleep problems and improvements in subjective sleep patterns (diary) across anxiety treatment, but outcomes were not deemed clinically significant, and 75% of youth stayed above clinical cutoff. Study 2 showed clinically significant, large reductions in sleep problems and small changes in some subjective sleep patterns (diary). Anxiety treatment improves, but does not resolve, sleep disturbance in peri-pubertal youth, which may portend risk for poor emotional adjustment and mental health. The open trial provides preliminary support that Sleeping TIGERS can improve sleep in anxious youth to a clinically significant degree.  相似文献   
9.
Improved design of nasogastric feeding tubes   总被引:1,自引:0,他引:1  
Disappointed with the overall performance of weighted and unweighted nasogastric feeding tubes, a design programme was initiated which resulted in the development of two new nasogastric tubes, one weighted and one unweighted. The tubes were manufactured with polyurethane rather than polyvinylchloride (PVC) which permitted an increase in diameter of the internal lumen which in turn was coated with water activated lubricant to ease removal of the introducer wire. A specially modelled outflow port was incorporated into the tips of both tubes. The performance of the two new polyurethane nasogastric feeding tubes was assessed under controlled trial condition using as a reference a widely used PVC unweighted open ended tube. While intubation times were similar in patients without concurrent endotracheal intubation, it took a significantly shorter time to intubate patients with concurrent endotracheal intubation with the new weighted tube. Following tube intubation, it was possible to aspirate gastric contents significantly more often through the new polyurethane tubes (p < 0.001) than through the PVC tube, and the unweighted polyurethane tube stayed in situ longer (p < 0.05) than the PVC tube. The newly designed polyurethane nasogastric feeding tubes are the first tubes that have been shown to have advantages over the simpler type of open ended, unweighted PVC nasogastric feeding tubes.  相似文献   
10.
This case report describes the complication of peristomal abscess formation associated with the insertion of a percutaneous endoscopic gastrostomy (PEG). The formation of a peristomal anterior abdominal wall abscess in this patient was associated with the failure to give prophylactic antibiotics. The development of this potentially fatal complication may be avoided by strict observance of insertion protocols. This case was treated by removal of the gastrostomy tube after diagnosis which allowed drainage of the abscess. In similar cases of occult abscess formation, where symptoms are present but signs are absent, ultrasonography may be useful in diagnosis.  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