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   115篇
  免费   4篇
  2022年   4篇
  2021年   12篇
  2020年   8篇
  2019年   13篇
  2018年   6篇
  2017年   6篇
  2016年   7篇
  2015年   7篇
  2014年   4篇
  2013年   10篇
  2012年   6篇
  2011年   8篇
  2010年   4篇
  2009年   3篇
  2008年   5篇
  2007年   4篇
  2006年   3篇
  2005年   2篇
  2004年   1篇
  2003年   2篇
  2002年   1篇
  1999年   1篇
  1969年   1篇
  1968年   1篇
排序方式: 共有119条查询结果,搜索用时 15 毫秒
71.
To examine, the predictors of incident chronic kidney disease (CKD) in a community-based cohort of Middle East population, during a mean follow-up of 9.9 years. In a sample of 3313 non-CKD Iranian adults ≥20 years the estimated glomerular filtration rate (eGFR) was calculated at baseline and at three year intervals during three consecutive phases. The eGFR <60 mL/min/1.73 m2 was defined as CKD. Multivariate Logistic regression analysis was used to determine the independent variables associated with incident CKD. The incidence density rates of CKD were 285.3 and 132.6 per 10,000 person-year, among women and men, respectively. Female gender per se was associated with higher risk of CKD, compared with males. Among women, age, eGFR, known diabetes, being single or divorced/widowed, hypertension (marginally significant) and current smoking were independent risk factors for CKD; however the intermediate degree of education and family history of diabetes decreased the risk by 40% (P<0.05). Among male subjects, independent predictors of developing CKD included aging and hypertension (with significantly higher risk than in women, P for interaction<0.05), eGFR, new diagnosed diabetes, high normal blood pressure; abdominal obesity decreased the risk of CKD about 30% which was marginally significant. In the Iranian population,>2% of individuals develops CKD each year. Our findings confirmed that sex- specific risk predictors should be considered in primary prevention for incident CKD.  相似文献   
72.

Objective

The aim of this study was to evaluate the validity of cause of death stated in death certificates in Tehran using outcome measures of the Tehran Lipid and Glucose Study (TLGS), an ongoing prospective cohort study.

Methods

The cohort was established in 1999 in a population of 15005 people, 3 years old and over, living in Tehran; 3551 individuals were added to this population three years later. As part of cohort''s outcome measures, deaths occurring in the cohort are investigated by a panel of medical specialists (Cohort Outcome Panel-COP) and underlying cause of death is determined for each death. The cause of death assigned in a deceased''s original death certificate was evaluated against the cause of death determined by COP and sensitivity and positive predictive values (PPV) were determined. In addition, determinants of assigning accurate underlying cause of death were determined using logistic regression model.

Result

A total of 231 death certificates were evaluated. The original death certificates over reported deaths due to neoplasms and underreported death due to circulatory system and transport accidents. Neoplasms with sensitivity of 0.91 and PPV of 0.71 were the most valid category. The disease of circulatory system showed moderate degree of validity with sensitivity of 0.67 and PPV of 0.78. The result of logistic regression indicated if the death certificate is issued by a general practitioner, there is 2.3 (95% CI 1.1, 5.1) times chance of being misclassified compared with when it is issued by a specialist. If the deceased is more than 60 years, the chance of misclassification would be 2.5 times (95% CI of 1.1, 5.9) compared with when the deceased is less than 60 years.  相似文献   
73.
A method for the formation of the trimethylsilyl (TMS) derivatives of the whole-cell hydrolysate of bacteria was developed. The TMS derivatives were examined by gas-liquid chromatography. TMS profiles of various bacteria at the genus and species level were compared. Differences in TMS profiles of Listeria, Neisseria, and Clostridium were significant as were differences between the TMS profiles of C. perfringens and C. sporogenes. Two types of C. perfringens, two serotypes of L. monocytogenes, and one culture of C. sporogenes and N. meningitidis were studied. The possible application of TMS profiles as an aid in differentiating closely related organisms which are troublesome to separate by conventional means is discussed.  相似文献   
74.
75.
Natural bond orbital (NBO), nuclear magnetic resonance (NMR) analysis and hybrid-density functional theory based method (B3LYP/Def2-TZVPP) were used to investigate the correlation between the nucleus-independent chemical shifts [NICS, as an aromaticity criterion], σ Al(1)-X2(b)σ*Al(3)-X4(b) electron delocalizations and the dissociation energies of Al2F6, Al2Cl6, Al2Br6 and Al2I6 to 2AlX3 (X?=?F, Cl, Br, I). The results obtained showed that the dissociation energies of Al2F6, Al2Cl6, Al2Br6 and Al2I6 decrease from Al2F6 to Al2I6. Like aromatic molecules, these compounds have relatively significant negative NICSiso(0) values. Clearly, based on magnetic criteria, they exhibit aromatic character and make it possible to consider them as σ-delocalized aromatic species, such as Möbius σ-aromatic species. The σ-aromatic character which is demonstrated by their NICSiso(0) values decreases from Al2F6 to Al2I6. The NICSiso values are dominated by the in-plane σ22 (i.e., σyy, the plane containing halogen atoms bridged) chemical shift components. The increase of the NICSiso values explains significantly the decrease of the corresponding dissociation energies of Al2F6, Al2Cl6, Al2Br6 and Al2I6. Importantly, the NBO results suggest that in these compounds the dissociation energies are controlled by the stabilization energies associated with σ Al(1)-X2(b)σ*Al(3)-X4(b) electron delocalizations. The decrease of the stabilization energies associated with σ Al(1)-X2(b)σ*Al(3)-X4(b) electron delocalizations is in accordance with the variation of the calculated NICSiso values. The correlations between the dissociation energies of Al2F6, Al2Cl6, Al2Br6 and Al2I6, σ Al(1)-X2(b)σ*Al(3)-X4(b) electron delocalizations, natural atomic orbitals (NAOs) and NICSiso values have been investigated.  相似文献   
76.
77.

Objective

To investigate the population-based incidence of type 2 diabetes and its potential risk factors in a sex-split cohort of Iranian population.

Materials and Methods

A total of 8400 non-diabetic participants, aged ≥20 years (3620 men and 4780 women) entered the study. Crude and age standardized incidence rates per 1000 person-years were calculated for whole population and each sex separately. Cox proportional hazard models were used to evaluate hazard ratios (HR) and 95% confidence intervals for all potential risk factors in both uni-variable and multivariable models.

Results

During a median follow-up of 9.5 years, 736 new cases of diabetes were identified, including 433 women and 303 men. The annual crude and age-standardized incidence rates (95% CI) of diabetes in the total population were 10.6 (9.92–11.4) and 9.94 (7.39–13.6) per 1000 person-years of follow-up and the corresponding sex specific rates were 10.2 (9.13–11.4) and 9.36 (5.84–14.92) in men and 11.0 (9.99–12.0) and 10.1 (7.24–13.9) in women, respectively. In the multivariable model, the risk for incident diabetes was significantly associated with fasting and 2 hour post challenge plasma glucose as well as family history of diabetes in both men and women. However, among women, only the contribution of wrist circumference to incident diabetes achieved statistical significance [HR: 1.16 (1.03–1.31)] with waist/height ratio being marginally significant [HR: 1.02 (0.99–1.04)]; while among men, only body mass index was a significant predictor [HR: 1.12 (1.02–1.22)]. Additionally, low education level conferred a higher risk for incident diabetes only among men [HR: 1.80 (1.23–2.36); P for interaction with sex = 0.003].

Conclusion

Overall, sex did not significantly modify the impact of risk factors associated with diabetes among Iranian adults; however, among modifiable risk factors, the independent role of lower education and general adiposity in men and central adiposity in women might require different preventive strategies.  相似文献   
78.
ObjectivePrehypertension is associated with cardiovascular disease (CVD). There is no study to examine the incidence and risk factors of prehypertension in a sex stratified setting. The aim of this study was to examine the effect modification of sex for different risk factors which predicts the progression from normotension to prehypertension in a Middle East population-based cohort, during a median follow-up of 9.2 years.MethodsA multivariate Cox analysis was performed among 1466 and 2131 Iranian men and women, respectively, who were free of prehypertension, hypertension, CVD and diabetes at baseline and free of incident hypertension without preceding prehypertension at follow-up. Incident prehypertension at follow-up was defined as systolic blood pressure (SBP) of 120–139 mmHg and/or diastolic blood pressure (DBP) of 80–89 mmHg.ResultsOverall, 1440 new cases of prehypertension were identified resulting in an incidence rate of 593/10000 person-years; the corresponding values for women and men were 489/10000 and 764/10000person-years, respectively. There were significant interactions between gender with age, DBP, waist-to-hip-ratio (WHpR) and estimated glomerular filtration rate (eGFR) (all P-values <0.05) in multivariate analysis. Strong associations were found between age, body mass index (BMI) and SBP with incident prehypertension in both genders. However, the effect of DBP and WHpR was significant among women and 2-hour post challenge plasma glucose (2h-PCPG)was an independent risk factor for men. In the sex-adjusted analysis, glomerular hyperfiltration [Hazard ratio (HR) and 95%CI: 1.01 (1.00–1.01), P-value = 0.02], age, BMI, WHpR, SBP and DBP had higher risks while being female [HR (95%CI): 0.81(0.69–0.94), P-value = 0.01] had a lower risk for incident prehypertension.ConclusionAccording to this study results, among Iranian population with high incidence of prehypertension, general adiposity and glomerular hyperfiltration in total, 2h-PCPG in men and central adiposity in women should be emphasized as risk factors for prehypertension.  相似文献   
79.
80.

Background:

We investigated the effects of Withania somnifera root (WS) on insulin resistance, tumor necrosis factor α (TNF-α), and interleukin-6 (IL-6) in fructose-fed rats.

Methods:

Forty-eight Wistar-Albino male rats were randomly divided into four groups (n=12); Group I as control, Group II as sham-treated with WS by 62.5mg/g per diet, Group III fructose-fed rats received 10%W/V fructose, and Group IV fructose- and WS-fed rats. After eight weeks blood samples were collected to measure glucose, insulin, IL-6, and TNF-α levels in sera.

Results:

Blood glucose, insulin, homeostasis model assessment for insulin resistance (HOMA-R), IL-6, and TNF-α levels were all significantly greater in the fructose-fed rats than in the controls. Treatment with WS significantly (P < 0.05) inhibited the fructose-induced increases in glucose, insulin, HOMA-R, IL-6, and TNF-α.

Conclusion:

Our data suggest that WS normalizes hyperglycemia in fructose-fed rats by reducing inflammatory markers and improving insulin sensitivity.Key Words: Withania somnifera, Insulin resistance, IL-6, TNF- α  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