72 research outputs found

    Flat-face epoxy-bonded concrete joints loaded in torsion:Physical modelling

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    Joints in concrete structures must perform under various complex loads including torsion. This paper reports the results of an experimental programme investigating the static torsional performance of epoxy-bonded concrete joints. Torsion tests were performed using a custom experimental setup able to apply torque on a hollow concrete prism with an epoxy joint in the middle. The tested specimens failed in both cohesive and mixed modes. The cohesive failure mode was characterised by cracking in the body of concrete, while the mixed mode also included partial debonding of the joint. The cohesive mode was dominant, more ductile and exhibited higher torsional strength. The cracking behaviour of the jointed specimens was typical of concrete prisms under torsion except that in the mixed mode a crack developed along the joint on two or three specimen sides. Digital Image Correlation, applied for monitoring surface strain, showed that inclined bands of high shear strain passed across the joint during the tests. The mechanism of concrete-epoxy debonding was investigated using two standard testing methods. The low shear strength of concrete near the epoxy joint was identified as the source for the weaker, stiffer and more brittle response of the mixed failure mode in the torsion tests

    Dietary sodium and potassium intake and their association with blood pressure in a non-hypertensive Iranian adult population: Isfahan salt study

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    Aim: The association of sodium (Na) and potassium (K) intake with blood pressure (BP) is an ongoing debate, especially in central Iran. We aimed to examine the mean Na and K intake, major sources of Na and the relationship between BP and dietary and urinary Na and K. Methods: This cross-sectional study was performed in central Iran in 2013-2014. A total of 796 non-hypertensive adults aged >18years were randomly recruited. The semi-quantitative food frequency questionnaire was used to assess dietary Na and K intake. Moreover, 24-hour urine samples were collected to measure 24-hour urinary Na (UNa) and K (UK) as biomarkers. BP was measured twice on each arm using a standard protocol. Results: The mean Na and K intake were 4309.6±1344.4 and 2732.7±1050.5mg/day, respectively. Table and cooking salt were the main sources of Na. Odds ratio (OR) (95% confidence interval (CI)) of the crude model in the highest quartile of UNa indicated a significant association with the higher risk of prehypertension (OR (95% CI): 2.09 (1.09-4.05); P for trend=0.007). After adjustment for potential confounders, prehypertension was significantly associated with increasing dietary Na/K ratio (OR (95% CI): 1.28 (1.01-1.57); P for trend=0.046) and UNa/UK ratio (OR (95% CI): 2.15(1.08-4.55); P for trend=0.029). Conclusions: Increasing dietary and urinary Na/K ratios and UNa were associated with elevated BP and prehypertension occurrence. These findings support the necessity of developing a salt reduction programme in our country. © 2016 Dietitians Association of Australia

    White Rice Consumption and CVD Risk Factors among Iranian Population

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    Association between white rice intake and risk factors of cardiovascular diseases remained uncertain. Most of the previous published studies have been done in western countries with different lifestyles, and scant data are available from the Middle East region, including Iran. This cross-sectional study was conducted in the structure of Isfahan Healthy Heart Program (IHHP) to assess the association between white rice consumption and risk factors of cardiovascular diseases. In the present study, 3,006 men were included from three counties of Isfahan, Najafabad, and Arak by multistage cluster random-sampling method. Dietary intake was assessed with a 49-item food frequency questionnaire (FFQ). Laboratory assessment was done in a standardized central laboratory. Outcome variables were fasting blood glucose, serum lipid levels, and anthropometric variables. Socioeconomic and demographic data, physical activity, and body mass index (BMI) were considered covariates and were adjusted in analysis. In this study, Student's t-test, chi-square test, and logistic regression were used for statistical analyses. Means of BMI among those subjects who consumed white rice less than 7 times per week and people who consumed 7-14 times per week were almost similar-24.8 +/- 4.3 vs 24.5 +/- 4.7 kg/m(2). There was no significant association between white rice consumption and risk factors of cardiovascular diseases, such as fasting blood sugar and serum lipid profiles. Although whole grain consumption has undeniable effect on preventing cardiovascular disease risk, white rice consumption was not associated with cardiovascular risks among Iranian men in the present study. Further prospective studies with a semi-quantitative FFQ or dietary record questionnaire, representing type and portion-size of rice intake as well as cooking methods and other foods consumed with rice that affect glycaemic index (GI) of rice, are required to support our finding and to illustrate the probable mechanism

    Association of adherence to the dietary approach to stop hypertension and Mediterranean diets with blood pressure in a non-hypertensive population: Results from Isfahan Salt Study (ISS)

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    Abstract Background and aims Hypertension is among the major risk factors for cardiovascular events in the Iranian population. This cross-sectional study was designed to examine the association of adherence to the dietary approaches to stop hypertension (DASH) and Mediterranean (MED) dietary patterns with the distribution of blood pressure and pre-hypertension prevalence. Methods and results This cross-sectional study was carried out in 1363 non-hypertensive adults. Adherence to the DASH and MED diets was calculated using a semi-quantitative food frequency questionnaire (FFQ). Hypertension was measured by the standard method. Multiple logistic regression was applied to obtain the odds ratio of pre-hypertension in the tertiles of MED and DASH dietary patterns. Compared to the lowest, participants with the highest adherence to the DASH dietary pattern had significantly lower systolic blood pressure (SBP) (111.3 ± 11.8 vs. 112.8 ± 12.5; P = 0.010) and diastolic blood pressure (DBP) (70.7 ± 9.2 vs. 71.8 ± 9.8; 0.042). There was no significant difference in the mean SBP and DBP among the participants across tertiles of MED or diet adherence. Higher scores of the DASH and MED diets were inversely associated with lower SBP after adjustment for all potential confounders (OR = −0.04, 95% CI = −0.29, −0.01, P = 0.039) and (OR = −0.04, 95% CI = −0.72, −0.02, P = 0.044), respectively. Also, DASH and MED dietary patterns was associated with reduced OR of pre-hypertension occurrence by 13% (OR: 0.87; 95% CI: 0.70–0.98; P for trend = 0.042) and 16% ([OR: 0.84; 95% CI: 0.69–0.97; P trend = 0.035), respectively. Conclusion Adherence to the DASH and MED diets was inversely associated with the odds for pre-hypertension and SBP

    White Rice Consumption and CVD Risk Factors among Iranian Population

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    Association between white rice intake and risk factors of cardiovascular diseases remained uncertain. Most of the previous published studies have been done in western countries with different lifestyles, and scant data are available from the Middle East region, including Iran. This cross-sectional study was conducted in the structure of Isfahan Healthy Heart Program (IHHP) to assess the association between white rice consumption and risk factors of cardiovascular diseases. In the present study, 3,006 men were included from three counties of Isfahan, Najafabad, and Arak by multistage cluster random-sampling method. Dietary intake was assessed with a 49-item food frequency questionnaire (FFQ). Laboratory assessment was done in a standardized central laboratory. Outcome variables were fasting blood glucose, serum lipid levels, and anthropometric variables. Socioeconomic and demographic data, physical activity, and body mass index (BMI) were considered covariates and were adjusted in analysis. In this study, Student\u2019s t-test, chi-square test, and logistic regression were used for statistical analyses. Means of BMI among those subjects who consumed white rice less than 7 times per week and people who consumed 7-14 times per week were almost similar\u201424.8\ub14.3 vs 24.5\ub14.7 kg/m2. There was no significant association between white rice consumption and risk factors of cardiovascular diseases, such as fasting blood sugar and serum lipid profiles. Although whole grain consumption has undeniable effect on preventing cardiovascular disease risk, white rice consumption was not associated with cardiovascular risks among Iranian men in the present study. Further prospective studies with a semi-quantitative FFQ or dietary record questionnaire, representing type and portion-size of rice intake as well as cooking methods and other foods consumed with rice that affect glycaemic index (GI) of rice, are required to support our finding and to illustrate the probable mechanism

    National and sub-national trends of salt intake in Iranians from 2000 to 2016 : a systematic analysis

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    Acknowledgements The authors wish to thank all the staff at the Non-Communicable Diseases Research Center of Tehran University of Medical Sciences for their support. Funding This study was supported by Iran University of Medical Sciences (Grant Number: 9221128206).Peer reviewedPublisher PD

    Erratum: Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017

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    Interpretation: By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning

    Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

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    Background: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10–54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10–14 years and 50–54 years was estimated from data on fertility in women aged 15–19 years and 45–49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories. Findings: From 1950 to 2017, TFRs decreased by 49\ub74% (95% uncertainty interval [UI] 46\ub74–52\ub70). The TFR decreased from 4\ub77 livebirths (4\ub75–4\ub79) to 2\ub74 livebirths (2\ub72–2\ub75), and the ASFR of mothers aged 10–19 years decreased from 37 livebirths (34–40) to 22 livebirths (19–24) per 1000 women. Despite reductions in the TFR, the global population has been increasing by an average of 83\ub78 million people per year since 1985. The global population increased by 197\ub72% (193\ub73–200\ub78) since 1950, from 2\ub76 billion (2\ub75–2\ub76) to 7\ub76 billion (7\ub74–7\ub79) people in 2017; much of this increase was in the proportion of the global population in south Asia and sub-Saharan Africa. The global annual rate of population growth increased between 1950 and 1964, when it peaked at 2\ub70%; this rate then remained nearly constant until 1970 and then decreased to 1\ub71% in 2017. Population growth rates in the southeast Asia, east Asia, and Oceania GBD super-region decreased from 2\ub75% in 1963 to 0\ub77% in 2017, whereas in sub-Saharan Africa, population growth rates were almost at the highest reported levels ever in 2017, when they were at 2\ub77%. The global average age increased from 26\ub76 years in 1950 to 32\ub71 years in 2017, and the proportion of the population that is of working age (age 15–64 years) increased from 59\ub79% to 65\ub73%. At the national level, the TFR decreased in all countries and territories between 1950 and 2017; in 2017, TFRs ranged from a low of 1\ub70 livebirths (95% UI 0\ub79–1\ub72) in Cyprus to a high of 7\ub71 livebirths (6\ub78–7\ub74) in Niger. The TFR under age 25 years (TFU25; number of livebirths expected by age 25 years for a hypothetical woman who survived the age group and was exposed to current ASFRs) in 2017 ranged from 0\ub708 livebirths (0\ub707–0\ub709) in South Korea to 2\ub74 livebirths (2\ub72–2\ub76) in Niger, and the TFR over age 30 years (TFO30; number of livebirths expected for a hypothetical woman ageing from 30 to 54 years who survived the age group and was exposed to current ASFRs) ranged from a low of 0\ub73 livebirths (0\ub73–0\ub74) in Puerto Rico to a high of 3\ub71 livebirths (3\ub70–3\ub72) in Niger. TFO30 was higher than TFU25 in 145 countries and territories in 2017. 33 countries had a negative population growth rate from 2010 to 2017, most of which were located in central, eastern, and western Europe, whereas population growth rates of more than 2\ub70% were seen in 33 of 46 countries in sub-Saharan Africa. In 2017, less than 65% of the national population was of working age in 12 of 34 high-income countries, and less than 50% of the national population was of working age in Mali, Chad, and Niger. Interpretation: Population trends create demographic dividends and headwinds (ie, economic benefits and detriments) that affect national economies and determine national planning needs. Although TFRs are decreasing, the global population continues to grow as mortality declines, with diverse patterns at the national level and across age groups. To our knowledge, this is the first study to provide transparent and replicable estimates of population and fertility, which can be used to inform decision making and to monitor progress. Funding: Bill & Melinda Gates Foundation
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