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   1036篇
  免费   30篇
  国内免费   1篇
耳鼻咽喉   7篇
儿科学   13篇
妇产科学   11篇
基础医学   104篇
口腔科学   48篇
临床医学   114篇
内科学   192篇
皮肤病学   52篇
神经病学   44篇
特种医学   33篇
外科学   161篇
综合类   10篇
预防医学   50篇
眼科学   36篇
药学   52篇
肿瘤学   140篇
  2023年   1篇
  2022年   1篇
  2021年   4篇
  2020年   1篇
  2019年   4篇
  2018年   4篇
  2017年   5篇
  2016年   8篇
  2015年   21篇
  2014年   19篇
  2013年   22篇
  2012年   125篇
  2011年   97篇
  2010年   22篇
  2009年   46篇
  2008年   133篇
  2007年   111篇
  2006年   116篇
  2005年   100篇
  2004年   62篇
  2003年   66篇
  2002年   63篇
  2001年   1篇
  2000年   3篇
  1999年   3篇
  1998年   3篇
  1997年   6篇
  1996年   6篇
  1995年   2篇
  1994年   2篇
  1993年   5篇
  1991年   2篇
  1974年   1篇
  1972年   1篇
  1970年   1篇
排序方式: 共有1067条查询结果,搜索用时 15 毫秒
1.
2.
3.
To evaluate the catabolic effects of dexamethasone therapy on protein metabolism, amino acid concentrations and urinary 3-methylhistidine (3MH) were measured in 28 premature infants who were included in a double-blind controlled study using early dexamethasone therapy in the prevention of bronchopulmonary dysplasia. Fifteen infants received dexamethasone (0.5mg/kg/day i.v.) and 13 infants received normal saline as control. Heparinized venous blood samples for amino acid analysis were obtained before the study and again at day 5 after starting the study. Urinary 3MH was measured on days 1, 3, 5, 7, 14, 21, and 28 of treatment. A substantial increase in amino acid concentrations was observed in infants receiving dexamethasone. Alanine, glutamine, citrulline, ornithine and cystine concentrations increased twofold or more. The 3MH:creatinine ratio was increased in the treated group. These metabolic effects were most likely due to an increase in protein catabolism.  相似文献   
4.
Chen YH  Lee MF  Lan JL  Chen CS  Wang HL  Hwang GY  Wu CH 《Allergy》2005,60(12):1518-1523
BACKGROUND: Forcipomyia taiwana is a tiny, blood-sucking midge that cause intense pruritis and swelling in sensitive individuals. It is distributed island-wide in rural Taiwan and Southern China. Objective: This study aimed to study the allergic immune responses and identify F. taiwana allergens. METHODS: Crude whole body F. taiwana extracts were prepared with phosphate-buffered saline. The specific IgE antibody was determined by enzyme-linked immunoassay and immunoblotting. Protein was analyzed by electrospray ionization tandem mass spectrometry. RESULTS: Among the 372 subjects that were exposed to F. taiwana bites, 179 (48%) reported an immediate skin reaction with/without delay reaction and 41(11.1%) reported a solely delay reaction. The skin of 21 subjects was tested with F. taiwana extract. Of these 21 subjects, 12 (57.1%) produced immediate skin reactions and contained high levels of specific IgE antibody against F. taiwana. Immunoblotting revealed that 11 allergenic components are able to bind specific IgE. Allergens of 22, 24, 35, 36, and 64 kDa bound 50, 50, 75, 66.7, and 75% of IgE-containing sera tested, respectively. Tryptic fragments of the 24, 35, 36, and 64 kDa allergens were analyzed by ESI-MS/MS. Selected tryptic peptides of 24, 35, and 36, and 64 kDa allergens exhibited significant sequence identity with triosephosphate isomerase of Anopheles merus,Tenebrio molitor,Ochlerotatus togoi, and Chrysops vittatus, fructose 1,6-bisphosphate aldolase of Antheraea yamamai and Homalodisca coagulata, and a slow muscle myosin S1 heavy chain of Homarusamericanus and a protein with unknown function from A. gambiae, respectively. The 35 and 36 kDa proteins may represent different isoforms of the fructose 1,6-bisphosphate aldolase. CONCLUSION: We conclude that immediate reaction to F. taiwana bites is IgE mediated and the 24 (For t 1), 35 (For t 2), and 64 kDa (For t 3) proteins are candidates for major F. taiwana allergens. Further studies are needed to confirm these allergens.  相似文献   
5.
BACKGROUND: After presenting two sisters with the rare form of congenital arrhinia, this syndrome is reviewed, an explanation of the pathogenesis is offered and the therapeutic options of the functional and aesthetic reconstruction are discussed. DISCUSSION: In cases of congenital arrhinia different degrees of respiratory distress, cyanotic episodes, and impaired food intake are described. Therefore after birth respiration and food intake need to be monitored to alleviate the situation through intubation or tracheotomy. The following conclusions could be made based on the literature overview. Little is known about the pathophysiology and a great variety of therapeutic interventions and reconstruction solutions with a wide spectrum of complications are described. Due to the numerous forms of complications, which need to be compared with the reconstructive results, indications for surgical reconstruction of the airway and plastic reconstruction of the nose during childhood must be defined very stringently. CONCLUSION: One method to achieve a satisfactory plastic result is with an osseointegrated prosthesis. This facial prosthesis can be inserted without complications and can guarantee an adequate result, whereas no impairment of maxillofacial development was noted.  相似文献   
6.
7.
Some evidence suggests that smoking, a family history of hematopoietic cancer, and use of hair dyes are associated with t(14;18)-defined subsets of non-Hodgkin's lymphoma (NHL) in men. To further evaluate these associations and to expand them to women, the authors determined t(14;18)(q32;q21) status by fluorescence in situ hybridization in 172 of 175 tumor blocks from a population-based case-control study conducted in Nebraska during 1983-1986. Exposures in 65 t(14;18)-positive cases and 107 t(14;18)-negative cases were compared with those among 1,432 controls. Odds ratios and 95% confidence intervals were calculated using polytomous logistic regression. Among men, smoking was not associated with risk of t(14;18)-positive or -negative NHL. Among women who had ever smoked cigarettes, there was an association with risk of t(14;18)-negative NHL (odds ratio (OR) = 1.9, 95% confidence interval (CI): 1.1, 3.3) but not t(14;18)-positive NHL (p-difference = 0.01). The risks for t(14;18)-negative NHL among women increased with longer duration (>30 years: OR = 2.1, 95% CI: 1.1, 4.1) and early initiation (age 相似文献   
8.
There have been several researches on the relationship between music and human physiological or psychological responses. However, there are cardiovascular index factors that have not been explored quantitatively due to the qualitative nature of acoustic stimuli. This study proposes and demonstrates an experimental design for quantification of cardiovascular responses to music stimuli in humans. The system comprises two components: a unit for generating and monitoring quantitative acoustic stimuli and a portable autonomic nervous system (ANS) analysis unit for quantitative recording and analysis of the cardiovascular responses. The experimental results indicate that the proposed system can exactly achieve the goal of full control and measurement for the music stimuli, and also effectively support many quantitative indices of cardiovascular response in humans. In addition, the analysis results are discussed and predicted in the future clinical research.  相似文献   
9.
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