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   1269466篇
  免费   94898篇
  国内免费   1620篇
耳鼻咽喉   16356篇
儿科学   41103篇
妇产科学   35004篇
基础医学   189949篇
口腔科学   34875篇
临床医学   118150篇
内科学   249351篇
皮肤病学   27350篇
神经病学   102121篇
特种医学   47014篇
外国民族医学   265篇
外科学   179644篇
综合类   25777篇
现状与发展   3篇
一般理论   568篇
预防医学   104827篇
眼科学   28079篇
药学   92868篇
  6篇
中国医学   2036篇
肿瘤学   70638篇
  2018年   13702篇
  2017年   10522篇
  2016年   11484篇
  2015年   13240篇
  2014年   18252篇
  2013年   27737篇
  2012年   37995篇
  2011年   40435篇
  2010年   23318篇
  2009年   22446篇
  2008年   38076篇
  2007年   40699篇
  2006年   40292篇
  2005年   39412篇
  2004年   37823篇
  2003年   36227篇
  2002年   35121篇
  2001年   56068篇
  2000年   57086篇
  1999年   48145篇
  1998年   13454篇
  1997年   12271篇
  1996年   12678篇
  1995年   11950篇
  1994年   11147篇
  1993年   10421篇
  1992年   38215篇
  1991年   37686篇
  1990年   36462篇
  1989年   35275篇
  1988年   32704篇
  1987年   32040篇
  1986年   30529篇
  1985年   28794篇
  1984年   21949篇
  1983年   19198篇
  1982年   11366篇
  1981年   10328篇
  1979年   20945篇
  1978年   15397篇
  1977年   12793篇
  1976年   11848篇
  1975年   12815篇
  1974年   15593篇
  1973年   15366篇
  1972年   14513篇
  1971年   13556篇
  1970年   12787篇
  1969年   12065篇
  1968年   11232篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
103.
Liver disease alters the pharmacokinetic and pharmacodynamic properties of hepatically eliminated drugs. The main factors influenced are plasma albumin levels, enzyme balance (induction & inhibition) and drug binding to tissue proteins. The influence of lidocaine on serum, heart and liver propranolol levels in Wistar rats after liver injury induced by carbon tetrachloride CCl4 0.4 ml/kg x 2/wkl, was investigated. 40 male Wistar rats were divided into four groups (I, II, III, IV; n=10), Group I animals received only propranolol (labelled + cold substance) 40 mg/kg/12 h p.o., group II propranolol plus lidocaine in a single dose of 4mg/kg s.c., group III was treated with CCl4 for 6 weeks and received propranolol x2 at the same dosage as group I, while group VI was treated with CCl4 and the same drug dosage as group II. The simultaneous administration of H3-propranolol and lidocaine increased propranolol levels in the serum and tissues. The liver in damaged animals showed an increase of propranolol level under lidocaine co-administration, probably due to CCl4 induced liver enzyme activity, resulting in a rapid propranolol metabolism or to competition between both drug protein binding sites. The increased propranolol levels in the heart after lidocaine administration were probably due to attributed to its high affinity for heart tissue. Consequently, as regards the therapeutic approach for patients with liver disease receiving propranolol their propranolol dosage should be reduced when lidocaine is co-administered.  相似文献   
104.
There is a great deal of interest in developing less invasive markers for monitoring airway inflammation and the effect of possible novel anti-inflammatory therapies that may take time to impact on disease pathology. Exhaled nitric oxide (eNO) has been shown to be a reproducible, noninvasive indicator of the inflammatory status of the airway in the clinic. The aim of the present study was to determine the usefulness of measuring eNO as a marker of the anti-inflammatory impact of glucocorticoid and an inhibitor of kappaB kinase-2 (IKK-2) inhibitor 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA-1), in a pre-clinical model of airway inflammation. Rats were given vehicle, budesonide or TPCA-1 prior to exposure to lipopolysaccharide, previously shown to induce an increase in eNO and airway neutrophilia/eosinophilia. Comparison of the effect of the two compounds on inflammatory components demonstrated a significant correlation between the impact on eNO and inflammatory cell burden in the airway. The current study demonstrates the usefulness of profiling potential disease-modifying therapies on exhaled nitric oxide levels and the way in which an effect on this noninvasive biomarker relates to effects on pathological parameters such as lung cellularity. Information from studies such as the current one would suggest that the measurement of exhaled nitric oxide has potential for monitoring inflammatory status in lung tissue.  相似文献   
105.
The present study compared four different sites and conditions for the measurement of maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) in 38 spontaneous breathing tracheotomised patients. Of the patients, 28 had chronic obstructive pulmonary disease (COPD). The four different conditions were: 1) through a cuff inflated cannula (condition A); 2) through the mouth with a deflated cannula (condition B); 3) through the mouth with a phonetic uncuffed cannula (condition C); and 4) through the mouth after stoma closure (condition D). Five trials in each condition were performed using a standardised method. The measurement of both MIP and MEP differed significantly depending on the condition of measurement. MIP taken in condition A was significantly higher when compared with conditions B, C and D. MEP in condition A was significantly higher when compared with condition B and D. In condition A the highest frequency of the best measurement of MIP and MEP was observed at the fourth and fifth effort, respectively. The same results were obtained after the selection of only COPD patients. In conclusion, respiratory muscle assessment differs significantly depending on measurement condition. Measurement through inflated cannula tracheotomy yields higher values of both maximal inspiratory and maximal expiratory pressure.  相似文献   
106.
Summary: A female patient with isovaleric acidaemia had a successful outcome from pregnancy.  相似文献   
107.
108.
Pulmonary hamartomas are usually an incidental finding and range in size from 1 cm to 8 cm in diameter in various series. We report a case of a massive pulmonary hamartoma (size 25.5 × 17.5 × 6.5 cm and weighing 1134 g) in a 61 year old male who presented with a short history of breathlessness. The tumour was arising from the medial border of the right lung and occupying most of the right chest extending in to the anterior mediastinum. The tumour was compressing the right lung and there was no evidence of infiltration into the surrounding structures. It was successfully treated by surgical resection and final histology was pulmonary hamartoma with predominantly adipose and leiomyomatous differentiation.  相似文献   
109.
    
Summary A patient with early bilateral nuclear cataracts and subsequent diagnosis of Fanconi–Bickel syndrome is described. Despite impaired galactose and glucose metabolism, cataracts have been reported in only few cases with this disorder. We conclude that Fanconi–Bickel syndrome should be considered in the differential diagnosis of neonatal cataracts. The pathogenesis of this complication has not been fully elucidated. Electronic supplementary material Supplementary material is available for this article at  相似文献   
110.
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