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   348篇
  免费   29篇
  国内免费   1篇
儿科学   56篇
妇产科学   6篇
基础医学   76篇
临床医学   25篇
内科学   41篇
皮肤病学   3篇
神经病学   27篇
特种医学   21篇
外科学   41篇
综合类   5篇
预防医学   9篇
眼科学   31篇
药学   30篇
肿瘤学   7篇
  2020年   2篇
  2019年   6篇
  2018年   4篇
  2017年   6篇
  2016年   5篇
  2015年   5篇
  2014年   8篇
  2013年   12篇
  2012年   18篇
  2011年   13篇
  2010年   13篇
  2009年   6篇
  2008年   15篇
  2007年   11篇
  2006年   15篇
  2005年   9篇
  2004年   14篇
  2003年   15篇
  2002年   15篇
  2001年   13篇
  2000年   9篇
  1999年   8篇
  1998年   7篇
  1997年   5篇
  1996年   9篇
  1995年   5篇
  1994年   5篇
  1993年   7篇
  1992年   11篇
  1991年   19篇
  1990年   12篇
  1989年   6篇
  1988年   3篇
  1987年   4篇
  1986年   2篇
  1985年   6篇
  1984年   4篇
  1981年   2篇
  1980年   2篇
  1979年   3篇
  1977年   4篇
  1975年   9篇
  1974年   6篇
  1973年   4篇
  1972年   2篇
  1971年   4篇
  1969年   3篇
  1968年   2篇
  1967年   2篇
  1965年   1篇
排序方式: 共有378条查询结果,搜索用时 15 毫秒
1.
Five infants with biopsy proved juvenile xanthogranuloma of the iris were reviewed. Early treatment with subconjunctival injection of steroids and topical steroid drops resulted in regression of the lesion in four patients. One patient, reviewed at the age of 8 months after glaucoma which had developed secondary to the iris xanthogranuloma, had been treated by surgery alone: the visual outcome was very poor.  相似文献   
2.
The morbidity of osteoporosis is caused by fractures. Vertebral fractures lead to pain and disability and a decrease in quality of life. A Working Party of the European Foundation for Osteoporosis has developed a specific questionnaire for patients with established vertebral osteoporosis. This questionnaire is intended for use in clinical trials. The questionnaire consists of questions and visual analogue scales in the following domains: pain, activities of daily living, jobs around the house, mobility, leisure and social activities, general health perception and mood. The questionnaire has been translated from English into French, German, Italian, Hebrew, Swedish and Dutch. The questionnaire is currently being validated in a multicentre study involving patients with stable osteoporosis and control subjects. Preliminary results indicate that the reproducibility is sufficient and that the questionnaire is able to discriminate between patients with vertebral osteoporosis and control subjects.  相似文献   
3.
1. A method for collecting duodenal juice and gastric content separately, in conscious rats, is described. Metal cannulas were implanted into the stomach fundus. For the main experiment a double lumen tube was inserted through the cannula via the pylorus into the duodenum. 2. The following secretion patterns were observed: a) In the resting state there was a constant flow rate of duodenal volume, bicarbonate, trypsin and amylase. b) Cholinergic stimuli were capable of increasing enzyme secretion as much as fourfold for a period of 30 to 40 min when administered as a single subcutaneous injection. This effect was annulled by atropine. c) Secretin and cholecystokinin-pancreozymin given together in a single injection s.c. or i.v., elicited a similarly strong response. d) Identical ranges of the secretion maxima were found with a tendency to decrease after the first hour, when the hormones were infused either s.c. or i.v. e) Doses from 0.5 to 25 U/100 g b.w. /hr showed identical responses. Doses below 0.2 U/100 g/hr were without effect. 3. Narcosis (pentobarbital) inhibited markedly the resting and stimulated enzyme secretion. 4. The method is suitable for examination of physiological and pharmacological effects on resting and stimulated enzyme secretion of the rat pancreas.  相似文献   
4.
The free intracellular calcium ion concentration ([Ca2+]i) was measured simultaneously with isometric force in strips of guinea-pig mesotubarium using the Fura-2 technique. During the relaxed period (5–15 min) between spontaneous contractions [Ca2+]i continues to decrease after full mechanical relaxation to reach a minimal level of 86±8 nM (n=9) just before the start of the next contraction. During the spontaneous contractions (5–15 min) [Ca2+]i reached a maximum of 211±19 nM and then oscillated between 155±16 nM and 194±9 nM. Increased extracellular Ca2+ concentration to 10 mM from the standard concentration of 1.5 mM caused a decreased frequency of spontaneous contractions and an increase in [Ca2+]i both in the relaxed and contracted states. In 10 mM extracellular Ca2+, addition of AlF4 , as 1 mM NaF + 10 M AlCl3, caused a sustained increase in [Ca2+]i and maintained force. Addition of verapamil (10 M) in this situation decreased [Ca2+]i to the resting level. The results suggest that the cyclic appearance of trains of action potentials is related to variation in [Ca2+]i, possibly via inactivation of Ca2+-dependent K+ channels.  相似文献   
5.
6.
The effects of K+ depolarization and of the muscarinic agonist carbachol on [Ca2+]i and force were investigated in smooth muscle sheets of the longitudinal layer of the ileum loaded with Fura-2. K+ -rich solutions increased [Ca2+]i and force to an initial peak value, which was determined by the concentration of [K+]o. Thereafter, [Ca2+]i and force declined to a lower maintained level. The Ca2+/force relationship observed during this contraction-relaxation cycle is represented by a clockwise hysteresis loop. At 140 mM [K+]o, this loop consisted of three components while at lower [K+]o a two-component loop was observed. The stimulation with 0.1 mM carbachol resulted in a transient increase of [Ca2+]i and force followed by a continuous decline of these parameters despite the presence of the drug. Its EC50 of relaxation was around 270 nM [Ca2+]i. The Ca2+/force relationship proceeded along a counterclockwise hysteresis loop during the contraction-relaxation cycle. The extent of this loop decreased but remained unaltered in its direction during repeated stimulation with carbachol. These results suggest that (a) both agonists increase force and [Ca2+]i during stimulation; (b) during depolarization with K+, desensitization to Ca2+ occurs resulting in a clockwise hysteresis loop; (c) during carbachol stimulation, a counterclockwise hysteresis is observed. This could be due to an increased sensitivity to Ca2+ mainly in tonic smooth muscle. These observations might be explained by a modulation of the Ca2+ sensitivity by sensitizing and desensitizing mechanisms. These modulations during different stimuli could be due to different myosin light-chain kinase/myosin light-chain phosphatase ratios.  相似文献   
7.
Radiologic identification of vertebral fractures is most important in the diagnosis and monitoring of patients with spinal osteoporosis. Different methods, using vertebral height measurements for fracture identification, have therefore been developed. We compared four methods for fracture identification in spinal x-rays of 62 female patients with primary osteoporosis. The methods of Hedlund and Gallagher, Melton et al., and Davies et al. are based on the ratio of heights within one vertebra or of the height ratios of adjacent vertebrae; all three methods result in counting the number of vertebral fractures. The fourth method of Minne et al. relates anterior, middle and posterior heights of the vertebrae between T5 and L5 to the respective heights of T4. The relative vertebral heights of patients with osteoporosis are compared to the respective relative heights (anterior, middle, and posterior) of normal subjects (T5-L5). This allows the identification of fractured vertebrae, as well as a quantification of the extent of deformation due to these fractures (spine deformity index, SDI). The same measurement data of 62 spinal x-rays of anterior, middle, and posterior heights between T4 and L5 were used to detect vertebral fractures by the four different methods. Correlation between the number of identified fractures by the different methods ranged between r = 0.56 and 0.83. On the other hand, we found a remarkable difference in the mean number of identified fractures and a discrepancy in the identification of single vertebrae as fractured or not. All four methods revealed an accumulation of fractures in the midthoracic area and in the region of transition from thoracic to lumbar spine. Vertebral fractures as identified by SDI were not detected by the other three methods in 12-29% of the cases, even if vertebral height reduction was more than 6 mm. The reliability of each method was examined by the determination of "decreasing" number of fractures during follow-up. A decrease in the number of fractures was found in about 25% patients, if using the three methods that count only the number of fractures. We obtained a 3.6% decrease in the number of fractures using the fourth method. Furthermore, the decrease in SDI values in follow-up was within the range of variance. We therefore believe that SDI and related procedures are reliable in quantifying spinal osteoporosis and monitoring during follow-up.  相似文献   
8.
9.
Public health systems need to make well-founded choices in order to distribute their scarce resources in the most efficient way. Given the number of cancer patients, public/private investments in oncology research, the growing number of new anti-cancer agents and consequent budget impact of cancer care, market access of cancer drugs has become delicate over the last decade. Furthermore, decision makers are challenged by ethical objections and endeavour to provide fair and equal access to treatments for cancer patients. The aim of this study is to generate an overview of market access procedures for cancer drugs in eight European countries and formulate advice for improvement of resource allocation. Results are obtained through a literature review and a qualitative questionnaire and validated by experts with proven knowledge about procedures for price setting and reimbursement of drugs. Diverse measures are applied in the studied countries to optimize reimbursement of cancer drugs such as adjusted cost-effectiveness threshold, regulations for off-label use and new market access agreements. Additionally, innovative cancer drugs are excluded from explicit cost control measures such as payback of budget excess by pharmaceutical companies and lump-sum payments per diagnostic related groups (DRG) in the hospital. The results suggest that cancer is prioritized above other disease areas. Further research is necessary to address the question if society attaches higher value to cancer drugs than to treatments for other diseases.  相似文献   
10.
A study was made in Belgium in order to assess the completeness and specificity of the recording of meningococcal disease by routine sources of information. Ninety-three cases identified in a hospital survey were linked with those recorded in mortality statistics, in the notification of communicable diseases, and by the National Reference Laboratory for meningococci. Statistics based on mortality data appeared to be of low validity. The overall completeness of recording was 44% for the notification of communicable disease, and 40% for the reference laboratory. When these two sources were used for surveillance, the completeness of case-finding increased to 56%. When the analysis was restricted to bacteriologically-confirmed cases, the completeness of recording was 62% for the notification system, 70% for the laboratory, and 84% for both sources. The surveillance of communicable diseases should rely on various sources of information. Laboratory data should be systematically used in order to improve both the completeness of recording and the specificity of case-ascertainment.  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