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   1165篇
  免费   68篇
  国内免费   15篇
儿科学   72篇
妇产科学   19篇
基础医学   136篇
口腔科学   17篇
临床医学   174篇
内科学   229篇
皮肤病学   13篇
神经病学   39篇
特种医学   229篇
外科学   124篇
综合类   41篇
预防医学   48篇
眼科学   4篇
药学   59篇
中国医学   1篇
肿瘤学   43篇
  2023年   3篇
  2021年   6篇
  2020年   5篇
  2019年   14篇
  2018年   21篇
  2017年   11篇
  2016年   20篇
  2015年   14篇
  2014年   40篇
  2013年   43篇
  2012年   44篇
  2011年   47篇
  2010年   28篇
  2009年   41篇
  2008年   37篇
  2007年   44篇
  2006年   33篇
  2005年   32篇
  2004年   31篇
  2003年   40篇
  2002年   19篇
  2001年   20篇
  2000年   26篇
  1999年   40篇
  1998年   44篇
  1997年   53篇
  1996年   43篇
  1995年   41篇
  1994年   26篇
  1993年   26篇
  1992年   20篇
  1991年   30篇
  1990年   21篇
  1989年   18篇
  1988年   26篇
  1987年   26篇
  1986年   24篇
  1985年   22篇
  1984年   11篇
  1983年   10篇
  1982年   21篇
  1981年   16篇
  1980年   22篇
  1979年   8篇
  1978年   16篇
  1977年   25篇
  1976年   13篇
  1975年   12篇
  1973年   3篇
  1963年   2篇
排序方式: 共有1248条查询结果,搜索用时 15 毫秒
1.
2.
The Kasabach-Merritt syndrome is characterized by thrombocytopenia and localized coagulopathy associated with a hemangioma. Most techniques applied to eradicate the tumor or accelerate its involution (surgery, radiation therapy, embolization) are invasive and require transfusion of large amounts of blood products. In some cases, medical treatment is the only alternative. Efficacy of steroids and antifibronolytic agents has already been described, but even this approach is associated with the administration of blood products. We report two cases of infants with Kasabach-Merritt syndrome associated with cardiac and hepatic hemangiomas. At admission, both had signs of cardiac failure. They were successfully treated with prednisone and epsilon-aminocaproic acid (EACA). Blood products were not required once the diagnosis was made. These observations have important implications for the management of patients with Kasabach-Merritt syndrome because they show that even in severe cases blood transfusions can be avoided by the use of prednisone and EACA.  相似文献   
3.
Bottomley  PA; Lee  Y; Weiss  RG 《Radiology》1997,204(2):403
  相似文献   
4.
Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).  相似文献   
5.
6.
卢日刚 《药学学报》1992,27(11):871-874
This paper provides a basic principle and experimental technique of derivative signal multiplier spectrophotometry in multicomponent mixture. A microcomputer was used to process the spectral data measured on a manual spectrophotometer (UV-7520) for the determination of moroxydine hydrochloride in Gan Mao Qing capsules. Quantitative analysis of multicomponent mixture can be done without sample separation. The selection of optimal wavelength pairs is performed through the program with a computer. The method needs no special spectrophotometer and is simple, rapid and easy to operate. The mean recovery was 99.98 +/- 0.53% (n = 12).  相似文献   
7.
8.
An original approach to the measurement of analytes in clinical chemistry has now become available, in which dry reagent strip technology is linked to measurement by reflectance spectroscopy. The present studies have evaluated the performance of the first of these test systems—for uric acid, urea and glucose, in serum—by comparison with conventional liquid chemistry methods. Satisfactory performance in terms of both precision and accuracy was obtained for all three test systems, the current “state-of-the-art” performance criteria being met; the Seralyzer system proved reliable and easy to use in the hands of trained operators. It should find a place as a “Stat” analyser in the laboratory, in specified wards and in Health Centres.  相似文献   
9.
For stereotactic radiosurgery using the Leksell Gamma Knife system, it is important to perform a pre-treatment verification of the maximum dose calculated with the Leksell GammaPlan (DLGP) stereotactic radiosurgery system. This verification can be incorporated as part of a routine quality assurance (QA) procedure to minimize the chance of a hazardous overdose. To implement this procedure, a formalism has been developed to calculate the dose DCAL(X,Y,Z,dav,t) using the following parameters: average target depth (dav), coordinates (X,Y,Z) of the maximum dose location or any other dose point(s) to be verified, 3-dimensional (3-dim) beam profiles or off-centerratios (OCR) of the four helmets, helmet size i, output factor Oi, plug factor Pi, each shot j coordinates (x,y,z)i,j, and shot treatment time (ti,j). The average depth of the target dav was obtained either from MRI/CT images or ruler measurements of the Gamma Knife Bubble Head Frame. DCAL and DLGP were then compared to evaluate the accuracy of this independent calculation. The proposed calculation for an independent check of DLGP has been demonstrated to be accurate and reliable, and thus serves as a QA tool for Gamma Knife stereotactic radiosurgery.  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