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   332篇
  免费   28篇
耳鼻咽喉   6篇
儿科学   2篇
妇产科学   2篇
基础医学   17篇
口腔科学   3篇
临床医学   45篇
内科学   99篇
神经病学   33篇
特种医学   4篇
外科学   64篇
综合类   9篇
预防医学   62篇
眼科学   4篇
药学   6篇
肿瘤学   4篇
  2022年   3篇
  2021年   10篇
  2019年   11篇
  2018年   9篇
  2017年   7篇
  2016年   7篇
  2015年   6篇
  2014年   8篇
  2013年   7篇
  2012年   18篇
  2011年   20篇
  2010年   4篇
  2009年   8篇
  2008年   18篇
  2007年   26篇
  2006年   19篇
  2005年   25篇
  2004年   15篇
  2003年   24篇
  2002年   10篇
  2001年   12篇
  2000年   5篇
  1999年   6篇
  1998年   3篇
  1995年   4篇
  1992年   2篇
  1990年   4篇
  1989年   2篇
  1988年   5篇
  1987年   3篇
  1986年   6篇
  1985年   4篇
  1984年   3篇
  1983年   5篇
  1981年   5篇
  1980年   2篇
  1978年   3篇
  1977年   1篇
  1976年   1篇
  1975年   2篇
  1974年   3篇
  1973年   4篇
  1972年   3篇
  1971年   1篇
  1970年   1篇
  1968年   1篇
  1967年   4篇
  1966年   1篇
  1965年   1篇
  1960年   1篇
排序方式: 共有360条查询结果,搜索用时 31 毫秒
351.
The aim of the present study was to compare the ability of the hypertriglyceridemic waist phenotype and the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) clinical criteria to predict coronary artery disease (CAD) risk in a sample of women. We studied 254 women among whom the presence/absence of CAD was assessed by angiography. The hypertriglyceridemic waist phenotype was defined as having both a high waist circumference (≥85 cm) and increased fasting triglyceride levels (≥1.5 mmol/L), whereas the presence of at least 3 of the 5 NCEP-ATP III criteria was used as the "reference" screening approach to identify women with the features of the metabolic syndrome. Women with hypertriglyceridemic waist were characterized by higher adiposity indices as well as by a more disturbed fasting metabolic risk profile compared with women without this phenotype. Similar differences were observed when comparing the metabolic profile of women with vs without at least 3 of the NCEP-ATP III clinical criteria. Moreover, differences in the Framingham risk score were essentially similar when women were considered at low or high risk by either hypertriglyceridemic waist or by NCEP-ATP III clinical criteria (P < .0001). Finally, both clinical phenotypes were predictive of CAD (hypertriglyceridemic waist: relative odds ratio, 2.1; 95% confidence interval, 1.1-3.8; P = .02; NCEP-ATP III clinical criteria: relative odds ratio, 2.5; 95% confidence interval, 1.4-4.6; P < .003). These results suggest that hypertriglyceridemic waist is a simple screening tool to identify women with clustering metabolic abnormalities and at increased CAD risk.  相似文献   
352.

Objective

Several risk-scoring systems have been developed to predict surgical mortality and complications in cardiac surgical patients, but none of the current systems include factors related to the intraoperative period. The purpose of this study was to develop a score that incorporates both preoperative and intraoperative factors so that it could be used for patients admitted to a cardiac surgical intensive care unit (ICU) immediately after surgery.

Method

Preoperative and intraoperative data from 30,350 patients in four hospitals were used to build a multiple logistic regression model estimating 30-day mortality after cardiac surgery. Sixty percent of the patients were used as a derivation group and forty percent as a validation group.

Results

Mortality occurred in 2.6% of patients (n = 790). Preoperative factors identified in the model were age, female sex, emergency status, pulmonary hypertension, peripheral vascular disease, renal dysfunction, diabetes, peptic ulcer disease, history of alcohol abuse, and refusal of blood products. Intraoperative risk factors included the need for an intra-aortic balloon pump, ventricular assist device or extracorporeal membrane oxygenation leaving the operating room, presence of any intraoperative complication reported by the surgeon, the use of inotropes, high-dose vasopressors, red blood cell transfusion, and cardiopulmonary bypass time. When used after surgery at ICU admission, the model had C-statistics of 0.86 in both derivation and validation sets to estimate the 30-day mortality.

Conclusions

Preoperative and intraoperative variables can be used on admission to a cardiac surgical ICU to estimate 30-day mortality. The score could be used for risk stratification after cardiac surgery and evaluation of performance of cardiac surgical ICUs.  相似文献   
353.
Type III phosphatidylinositol-4-kinase beta (PI4KIIIβ) was previously implicated in hepatitis C virus (HCV) replication by small interfering RNA (siRNA) depletion and was therefore proposed as a novel cellular target for the treatment of hepatitis C. Medicinal chemistry efforts identified highly selective PI4KIIIβ inhibitors that potently inhibited the replication of genotype 1a and 1b HCV replicons and genotype 2a virus in vitro. Replicon cells required more than 5 weeks to reach low levels of 3- to 5-fold resistance, suggesting a high resistance barrier to these cellular targets. Extensive in vitro profiling of the compounds revealed a role of PI4KIIIβ in lymphocyte proliferation. Previously proposed functions of PI4KIIIβ in insulin secretion and the regulation of several ion channels were not perturbed with these inhibitors. Moreover, PI4KIIIβ inhibitors were not generally cytotoxic as demonstrated across hundreds of cell lines and primary cells. However, an unexpected antiproliferative effect in lymphocytes precluded their further development for the treatment of hepatitis C.  相似文献   
354.
LFF571 is a novel semisynthetic thiopeptide and potent inhibitor of Gram-positive bacteria. We report that the antibacterial activity of LFF571 against Clostridium difficile is due to inhibition of translation. Single-step mutants of C. difficile with reduced susceptibility to LFF571 were selected at frequencies of <4.5 × 10(-11) to 1.2 × 10(-9). Sequencing revealed a G260E substitution in the thiopeptide-binding pocket of elongation factor Tu. Importantly, this mutation did not confer cross-resistance to clinically used antimicrobials. These results support the development of LFF571 as a treatment for C. difficile infection.  相似文献   
355.
Parents of children with chronic illnesses experience tremendous burden when caring for their children at home. There are many challenges that are present throughout the course of chronic illnesses. To provide better care to the family caring for an ill child at home, clinicians must understand the experiences family members go through on a daily basis. The purpose of this article is to help clinicians better understand these parental experiences; by increasing clinicians' awareness, strategies can then be used, which will improve the outcome for the child, parents, and siblings.  相似文献   
356.
Synthetic studies of the antimicrobial secondary metabolite thiomuracin A (1) were initiated to improve chemical stability and physicochemical properties. Functional group modifications of 1 included removing the C2-C7 side chain, derivatizing the C84 epoxide region, and altering the C44 hydroxyphenylalanine motif. The resulting derivatives simplified and stabilized the chemical structure and were evaluated for antibacterial activity relative to 1. The simplified structure and improved organic solubility of the derivatives facilitated isolation yields from fermentation broths and simplified the procedures involved for the process. These advancements increased material supply for continued medicinal chemistry optimization and culminated in the identification of 2, a structurally simplified and chemically stable analogue of 1 which retained potent antibiotic activity.  相似文献   
357.
358.
359.
CONTEXT: Overexpression of endothelial lipase (EL) has been shown to reduce plasma high-density lipoprotein cholesterol levels in animal models. However, the extent to which EL contributes to modulate the deteriorated high-density lipoprotein profile observed in obesity in humans is less clear. OBJECTIVES: The objectives of this study were to investigate the association between levels of obesity and visceral adiposity in particular and plasma EL concentrations. METHODS: Postheparin plasma EL concentrations were measured by ELISA and visceral adiposity by computed tomography in a sample of 80 sedentary men in good health. EL mRNA levels in abdominal sc and omental adipose tissues obtained during abdominal hysterectomies were measured in another sample of 14 women. RESULTS: Plasma EL levels were positively correlated with body mass index (R = 0.46, P < 0.0001), visceral adipose tissue accumulation (R = 0.44, P < 0.0001), and a proatherogenic lipid profile including increased plasma cholesterol and triglycerides. However, EL mRNA levels were similar in sc and omental AT and were 10,000-fold lower than lipoprotein lipase mRNA levels in those tissues. CONCLUSIONS: Increased visceral adiposity is significantly correlated with elevated plasma EL levels, but this association is unlikely to be causal and may reflect other common metabolic alterations.  相似文献   
360.
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