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   329篇
  免费   12篇
耳鼻咽喉   6篇
儿科学   26篇
妇产科学   20篇
基础医学   25篇
口腔科学   6篇
临床医学   20篇
内科学   37篇
皮肤病学   4篇
神经病学   23篇
特种医学   96篇
外国民族医学   1篇
外科学   27篇
综合类   2篇
预防医学   9篇
眼科学   1篇
药学   16篇
肿瘤学   22篇
  2019年   4篇
  2018年   3篇
  2016年   2篇
  2015年   5篇
  2014年   7篇
  2013年   2篇
  2012年   11篇
  2011年   7篇
  2010年   4篇
  2009年   7篇
  2008年   11篇
  2007年   6篇
  2006年   7篇
  2005年   4篇
  2004年   11篇
  2003年   11篇
  2002年   9篇
  2001年   7篇
  2000年   6篇
  1999年   9篇
  1998年   2篇
  1997年   4篇
  1992年   11篇
  1991年   5篇
  1990年   8篇
  1989年   10篇
  1988年   10篇
  1987年   2篇
  1986年   9篇
  1985年   3篇
  1984年   3篇
  1983年   5篇
  1982年   3篇
  1981年   4篇
  1980年   6篇
  1979年   7篇
  1978年   8篇
  1977年   10篇
  1976年   9篇
  1975年   8篇
  1974年   9篇
  1973年   10篇
  1972年   3篇
  1971年   6篇
  1970年   8篇
  1969年   12篇
  1968年   6篇
  1967年   7篇
  1966年   5篇
  1965年   4篇
排序方式: 共有341条查询结果,搜索用时 15 毫秒
1.
The effect of listing fewer laboratory tests on the test request form on test-ordering behavior of a group of 47 Dutch general practitioners was studied. The number of laboratory tests ordered by this experimental group during a 12-month period was recorded. The usual, old standard form was used by a control group of 28 general practitioners in a different region. After having used the old, standard form with 178 tests for 5 months, the experimental group received forms listing only 15 hematological and chemical tests plus several urine and feces tests, and space was allowed for "others." A comparison of the experimental and control periods showed that the number of tests ordered monthly in the experimental group was reduced by 18%. When the usual standard form was re-introduced, the general practitioners quickly returned to their old pattern. Results revealed that fixed and often unsound routine influences the use of additional diagnostic procedures. In addition, limiting and restructuring the test-ordering forms may break the routine but does not essentially modify the rationale of test-ordering behavior.  相似文献   
2.
Dieulafoy's ulcer is a particular form of gastric ulcer confined to a persistent caliber artery and may lead to severe hemorrhage. We report a case of fatal gastric bleeding in a woman with benign biclonal gammapathy. Autopsy found a typical Dieulafoy's ulcer centered by a persistent caliber artery which wall was thickened by AL-amyloid deposits. Amyloidosis involved the gastric wall, but also middle caliber arteries of the liver, the lung, the pancreas, the kidney and the myocardium. AL-amyloidosis is a rare and late complication of monoclonal gammapathy and may be asymptomatic. Pathogenesis of Dieulafoy's ulcer remains unclear. In our case, local ischemia may have facilitated gastric ulceration, and amyloid deposits may have contributed to arterial rupture.  相似文献   
3.
4.
5.
6.
The clinical, left ventricular and coronary angiographic data, and the technetium-99m stannous pyrophosphate (99mTc-PYP) myocardial scintigraphic results are presented in 31 patients with unstable angina pectoris. One-third of these patients had positive 99mTc-PYP myocardial scintigrams in a pattern suggesting limited and diffuse subendocardial necrosis. The positive 99mTc-PYP myocardial scintigrams occurred without diagnostic electrocardiographic and cardiac enzyme changes suggestive of myocardial infarction; positive scintigrams seemed to occur more commonly in patients with continuing pain after admission and in those without previous history of myocardial infarction. The positive 99mTc-PYP myocardial scintigrams did not correctly predict coronary anatomical patterns except that positive scintigrams occurred only in patients with coronary artery disease. Neither did the positive scintigrams necessarily occur in that group of patients with the poorest ventricular function though the 2 patients with the lowest ejection fractions both had positive 99mTc-PYP myocardial scintigrams. Finally, when positive 99mTc-PYP scintigrams are the only evidence suggestive of limited subendocardial infarction in patients with unstable angina pectoris, they do not appear to have any prognostic significance in terms of longevity or response to pharmacological or surgical therapy, though the follow-up period so far is short.  相似文献   
7.
Eighty-eight patients admitted to a coronary care unit with chest pain of varying etiology but without ECG evidence of an acute transmural myocardial infarction had myocardial scintigrams using technetium-99m stannour pyrophosphate (99m-Tc-PYP). Seventeen of these patients had ECG and enzymatic evidence suggestive of acute subendocardial myocardial infarction. In each of these the scintigrams were postivie demonstrating increased 99m-Tc-PYP uptake either in a faintly but diffusely positive pattern or in a well-localized strongly positive one. The remaining 71 patients did not evolve ECG or enzymatic evidence of acute myocardial infarction. In each of these patients the myocardial scintigram was negative. Thus 99m-Tc-PYP myocardial scintigrams are capable of identifying the presence of acute subendocardial myocardial infarction in patients. The absolute frequency with shich subendocardial myocardial infarction can be recognized utilizing this technique will have to be established in a larger number of patients in the future.  相似文献   
8.
Technetium-99m stannous pyrophosphate was utilized for myocardial imaging in 202 patients admitted to the hospital with chest pain of uncertain etiology. One hundred and one patients had clinical and evolved electrocardiographic and enzymatic evidence of acute myocardial infarction. Ninety-six of these 101 patients had increased myocardial uptake of the technetium stannous pyrophosphate and positive myocardial scintigrams; there was nearly precise correlation between the ECG and myocardial imaging localization of the area of infarction for acute transmural myocardial infarctions. In the five patients with negative myocardial images the scintigrams were obtained after seven or more days had elapsed following the myocardial infarction. In the remaining 101 patients no clinical, ECG, or enzymatic evidence of infarction developed; 92 of these patients had negative myocardial scintigrams. Seven of the remaining nine patients were admitted with "unstable angina pectoris", and despite the absence of diagnostic ECG and enzyme evolution each of these patients had faintly and diffusely positive myocardial scintigrams. The remaining two patients had positive myocardial scintigrams but no definite ECG or enzymatic evidence of acute myocardial infarction. Thus the technetium pyrophosphate imaging technique appears safe, inexpensive and to correlate well with ECG and enzyme identification of the presence of infarction and with ECG localization of myocardial infarction. In addition the positive myocardial scintigrams in some patients with "unstable angina" suggest that there may be limited myocardial necrosis that is ordinarily undetected by ECG and enzymes in these patients. The incidence of false positive and false negative scintigrams appears to be small.  相似文献   
9.
Granulomas in sarcoidosis express high levels of 1α‐hydroxylase, an enzyme that catalyzes the hydroxylation of 25‐OH vitamin D to its active form, 1,25(OH)2 vitamin D. Overproduction of 1α‐hydroxylase is held responsible for the development of hypercalcemia in sarcoidosis patients. Corticosteroids are used as first‐line treatment in organ‐threatening sarcoidosis. In this light, osteoporosis prevention with calcium and vitamin D (CAD) supplementation is often warranted. However, sarcoidosis patients are at risk for hypercalcemia, and CAD supplementation affects the calcium metabolism. We studied calcium and vitamin D disorders in a large cohort of sarcoidosis patients and investigated if CAD supplementation is safe. Retrospectively, data of 301 sarcoidosis patients from July 1986 to June 2009 were analyzed for serum calcium, 25‐hydroxy vitamin D (25‐(OH)D), 1,25‐dihydroxy vitamin D (1,25(OH)2D), and use of CAD supplementation. Disease activity of sarcoidosis was compared with serum levels of vitamin D. Hypercalcemia occurred in 8%. A significant negative correlation was found between 25‐(OH)D and disease activity of sarcoidosis measured by somatostatin receptor scintigraphy. In our study, 5 of the 104 CAD‐supplemented patients developed hypercalcemia, but CAD supplementation was not the cause of hypercalcemia. Patients without CAD supplementation were at higher risk for developing hypercalcemia. During CAD supplementation, no hypercalcemia developed as a result of supplementation. Hypovitaminosis D seems to be related with more disease activity of sarcoidosis and, therefore, could be a potential risk factor for disease activity of sarcoidosis. Thus, vitamin D–deficient sarcoidosis patients should be supplemented. © 2014 American Society for Bone and Mineral Research.  相似文献   
10.
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