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   1803篇
  免费   129篇
  国内免费   7篇
耳鼻咽喉   21篇
儿科学   75篇
妇产科学   53篇
基础医学   257篇
口腔科学   130篇
临床医学   129篇
内科学   378篇
皮肤病学   41篇
神经病学   166篇
特种医学   92篇
外科学   215篇
综合类   6篇
预防医学   175篇
眼科学   39篇
药学   75篇
中国医学   8篇
肿瘤学   79篇
  2023年   9篇
  2022年   31篇
  2021年   44篇
  2020年   20篇
  2019年   44篇
  2018年   50篇
  2017年   35篇
  2016年   43篇
  2015年   61篇
  2014年   75篇
  2013年   87篇
  2012年   120篇
  2011年   151篇
  2010年   81篇
  2009年   58篇
  2008年   89篇
  2007年   78篇
  2006年   89篇
  2005年   61篇
  2004年   66篇
  2003年   46篇
  2002年   51篇
  2001年   41篇
  2000年   42篇
  1999年   31篇
  1998年   11篇
  1997年   20篇
  1996年   23篇
  1995年   17篇
  1994年   22篇
  1993年   18篇
  1992年   16篇
  1991年   22篇
  1990年   12篇
  1989年   27篇
  1988年   21篇
  1987年   24篇
  1986年   21篇
  1985年   19篇
  1984年   13篇
  1983年   13篇
  1982年   8篇
  1980年   12篇
  1979年   13篇
  1978年   13篇
  1977年   11篇
  1976年   9篇
  1972年   8篇
  1969年   7篇
  1966年   9篇
排序方式: 共有1939条查询结果,搜索用时 31 毫秒
21.
A syndrome heralded by fever, deterioration of graft function, respiratory failure accompanied by pulmonary infiltrates has been termed "transplant lung." We hemodynamically studied eight such patients. At the height of their illness, pulmonary artery wedge pressure (PAWP) was elevated to 19.3 +/- 2.6 mm Hg along with mean pulmonary artery pressure (PAP) of 35.0 +/- 3.8 mm Hg in presence of increased cardiac index (CI) of 4.9 +/- 0.9 L.m2.min. Pathophysiology of pulmonary edema appears to include high left ventricular filling pressures, pulmonary hypertension, alterations of oncotic hydrostatic gradient, and increased cardiac output. A partial reversal of pulmonary hypertension was observed with dialysis or diuresis. Our data suggest incipient renal failure and fluid accumulation as the etiology of hemodynamic pulmonary edema in "transplant lung."  相似文献   
22.
The rate of metabolism of ethanol in humans has been assessedby intravenous infusion of ethanol/saline under feedback controlto maintain a constant blood alcohol concentration. After equilibration,meals consisting predominantly of carbohydrate, fat or proteinwere eaten and changes in ethanol metabolic rate were found.Carbohydrate caused a significant increase in this rate andfat or protein caused small but non-significant decreases. Infusionof ethanol/saline resulted in a temporary fall in plasma freefatty acid levels and a steady rise in plasma triglycerides.The changes in alcohol metabolism following carbohydrate cannotbe accounted for by changes in insulin, free fatty acid or lactate/pyruvatelevels.  相似文献   
23.
24.
ObjectiveThis study aimed to evaluate how cold ischemia time (CIT) interferes with liver graft function in the first 7 days after surgery for Custodiol (HTK) preserved organs.MethodsThis retrospective observational study analyzed the medical records of 38 transplantation patients at Hospital Leforte Liberdade, São Paulo, in 2018. The study population was divided into 2 groups (group A, CIT < 8 hours; group B, CIT > 8 hours). Postoperative parameters—such as international normalized ratio, total bilirubin, aspartate aminotransferase/alanine aminotransferase, alkaline phosphatase, gamma glutamyl transferase (GGT), lactate dehydrogenase, lactate, creatinine, red blood cell transfusion, need for hemodialysis, use of vasoactive drugs, endotracheal intubation time, length of stay in the intensive care unit (ICU), and length of hospital stay—were compared.ResultsGroup A (CIT < 8 hours) presented less need for red blood cell transfusions (odds ratio 0.29; confidence interval 0.06-0.98; P = .04), had a shorter hospital stay (P = .024), and had lower levels of total bilirubin (P = .05) and GGT (P = .05) in the first 7 postoperative days. The other variables showed no statistically significant difference.ConclusionIn livers preserved with Custodiol, CIT > 8 hours generated higher levels of total bilirubin and GGT in the postoperative period, in addition to higher hospital costs; greater need for red blood cell transfusions; and longer hospitalization, including longer stays in the ICU.  相似文献   
25.
This review covers last year's literature on corneal, limbal, and conjunctival transplantation including tissue storage and eye banking. In this area, the main themes were related to a better evaluation of tissue viability and the exclusion of disease transmission. An analysis of the changing indications for penetrating keratoplasty shows the differences between American and European series. Most efforts in relation to surgical techniques are oriented toward obtaining better refractive results, whereas the study of large series sheds new light on the risk factors for graft failure and other complications. Limbal transplants have acquired the status of a new field in the surgical treatment of ocular surface disease, particularly in relation to corneal stem cell deficiencies.  相似文献   
26.
This article examines the functional approach to attitudes for its potential contribution to improving models of attitude-behavior consistency and to demonstrate its potential application to social marketing. To this end, a study of children's attitudes toward bicycle helmets is reported on and its results examined. The study was undertaken to plan Israel's first-ever media campaign to encourage the use of helmets by children. Responses of the 783 Israeli children (ages 7 to 14 years) who participated in the study are analyzed to test the hypothesis generated by this application of functional theory--that children's attitudes toward wearing bicycle helmets serve primarily an expressive function. The results suggest cautious support for the functional hypothesis. In conclusion, possible extensions of this approach to other areas of social marketing are discussed.  相似文献   
27.
BACKGROUND: For treatment of phosphate (Pi) overload in various pathophysiological states, an agent that selectively increases renal Pi excretion would be of major value. Previously, we have shown that dopamine (DA) inhibits Na(+)-Pi cotransport in renal epithelia. However, the administration of DA or its immediate precursor L-DOPA increases DA in multiple tissues. Synthetic dipeptide gamma-L-glutamyl-L-DOPA (gludopa) can serve as an inactive precursor (pro-pro-drug) of DA. This study tested the hypothesis that, because of the unique colocalization of gamma-glutamyltransferase (gamma-GT), aromatic amino acid decarboxylase, Na(+)-Pi cotransporter, and Na(+)-L-DOPA cotransporter in brush border membrane (BBM) of proximal tubular cells, gludopa may elicit phosphaturia by action of DA generated within the kidney. METHODS: Thyroparathyrectomized rats were given placebo, or gludopa, or gludopa + gamma-GT inhibitor acivicin. Urinary excretion of Pi, Ca2+, Na+, K+, DA, cAMP, and cGMP was determined, and Na(+)-Pi cotransport was measured in BBM prepared from kidneys of rats at the end of the experiment. RESULTS: The administration of gludopa resulted in: (a) an inhibition of Na(+)-Pi cotransport, but not cotransport of Na(+)-proline and Na(+)-alanine in BBM; (b) an increase (+300%) of fractional excretion (FE) of Pi and a drop (-35%) of plasma Pi, whereas the plasma levels and FEs of Ca2+, Na+, and K+ were unchanged; (c) an increase in urinary excretion of cAMP. but not cGMP; (d) a 1000-fold increase of urinary excretion of DA, without a change in excretion of norepinephrine; and (e) an incubation of gludopa with BBM in vitro, which caused a release of L-DOPA, and the in vivo administration of acivicin, which blocked actions of gludopa to inhibit Na(+)-Pi cotransport and to increase urinary excretions of Pi and DA. CONCLUSIONS: We conclude that colocalization of enzymes of biotransformation, BBM transporters, and the autocrine/paracrine DA system in cells of proximal tubules constitutes a cellular basis for the potent and specific phosphaturic action of gludopa.  相似文献   
28.
Syringe liposculpture: A two-year experience   总被引:1,自引:0,他引:1  
Syringe liposcupture is a method that combines two relatively new techniques of plastic surgery: syringe liposuction and fat grafting. We can reshape the face and the body by removing localized fat deposits and reinjecting this fat where needed. When we do not reinject, we call the technique reduction liposculpture. In 1989 we introduced a new technique—superficial syringe liposculpture—to treat patients with flaccid skin, superficial irregularities or depressions, cellulite, and liposuction sequelae. The technique combines syringe liposculpture, superficial liposuction, and our method of treating skin irregularities by breaking the fibrous adherences and injecting fat superficially.  相似文献   
29.
Syringe liposculpture: a two-year experience   总被引:2,自引:0,他引:2  
Syringe liposculpture is a method that combines two relatively new techniques of plastic surgery: syringe liposuction and fat grafting. We can reshape the face and the body by removing localized fat deposits and reinjecting this fat where needed. When we do not reinject, we call the technique reduction liposculpture. In 1989 we introduced a new technique--superficial syringe liposculpture--to treat patients with flaccid skin, superficial irregularities or depressions, "cellulite," and liposuction sequelae. The technique combines syringe liposculpture, superficial liposuction, and our method of treating skin irregularities by breaking the fibrous adherences and injecting fat superficially.  相似文献   
30.
Childhood cancer mortality has sharply declined in most economically developed countries over the last years, whereas no substantial changes in the incidence have been observed. In Catalonia (Spain), childhood cancer mortality showed a considerable decline until 1992, but incidence trends have not been analysed in this population. To assess both recent incidence and mortality trends in this population, we analysed childhood (0-14 years) cancer data from the population-based Tarragona Cancer Registry and from the Mortality Registry of Catalonia (Spain) from 1980 to 1998. All cancer mortality decreased by -2.6% annually in boys (95% confidence interval, 95% CI -3.7, -1.6) and -3.7% in girls (95% CI -4.9, -2.5). Mortality due to leukaemia decreased annually -3.0% in boys (95% CI -4.7, -1.4) and -4.4% in girls (95% CI -6.3, -2.4). Mortality for brain tumours showed a reduction of -3.2% in boys (95% CI -5.5, -0.9) and of -4.4% in girls (95% CI -6.3, -2.4). No significant trend in incidence rates, either in boys or in girls, was observed (annual per cent of change for all cancers -0.5%, 95% CI -3.5, 2.7, in boys and 1.7%, 95% CI -1.9, 5.5, in girls). These results suggest an improvement in both childhood cancer diagnosis and treatment, which may explain current higher childhood cancer survival rates.  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