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The hydrodynamic performance of turbulent flows in circular pipes equipped with screen-type static mixers is numerically assessed in this study. A three-dimensional computational fluid dynamics model is used to study the effect of changing the operating conditions and reactor configuration on the flow field. The accuracy of the numerical results is validated by comparing pressure drop predictions to empirical correlations where a maximum relative error of 13.3% is recorded. The macro-mixing performance of screen type static mixers is also assessed using residence time distributions. The study shows that the flow through screens is three-dimensional by nature with secondary flows being prominent near the pipe walls. Moreover, the presence of the screen has a major impact on the turbulent velocity profile both up- and down-stream. The flow field and velocity gradients are interpreted using strain rate and vorticity. These parameters also show that the flow through screens is highly dispersive where 39.3% of the reactor volume has an extensional efficiency value greater than 0.6. This explains their good performance in processing multiphase flows and gives an insight on how to design systems that maximize this dispersive effect in their volume. The residence time distribution study shows that the presence of screens renders the flow closer to plug flow with the effect being more pronounced using finer mesh screens operating at high flow velocities. [ABSTRACT FROM AUTHOR]

We have theoretically studied the spin structure factors of Heisenberg model on Lieb lattice in the presence of magnetic field along perpendicular to the plane and Dzyaloshinskii–Moriya interaction. The original spin model Hamiltonian is mapped to a bosonic model using a hard-core bosonic transformation. Under such transformation, an infinite hard-core repulsion is imposed to constrain one boson occupation per site. Based on Green's function approach, the energy spectrum of quasiparticle excitation has been obtained. The spectrum of the bosonic gas has been implemented in order to obtain two-particle propagator which corresponds to spin structure factor of original Heisenberg chain model Hamiltonian. The results show the peak position in the dynamical transverse spin structure factor at fixed value for Dzyaloshinskii–Moriya interaction moves to higher frequency with enhancement of magnetic field. However, the intensity of peaks in dynamical transverse spin structure factor is not affected by magnetic field. Also the Dzyaloshinskii–Moriya interaction strength causes to increase the intensity of dynamical longitudinal spin structure factor. Also the increase in magnetic field causes to move the frequency position of peaks in dynamical longitudinal spin susceptibility toward low frequencies. Our results show static transverse structure factor is found to be monotonically decreasing with magnetic field. Moreover, a monotonic reduction behavior for temperature dependence of static spin susceptibility has been observed for temperature dependence at each value of Dzyaloshinskii–Moriya interaction strength. [ABSTRACT FROM AUTHOR]

This paper characterizes the hydrodynamics of laminar flows through circular ducts equipped with plain square woven meshes/screens in their role as static mixers. The CFD model was used to investigate the effect of screen geometry, number of screens, inter-screen spacing, and operating conditions on the velocity and pressure fields. This work therefore presents an analysis of the velocity contours, streamlines, and profiles at various locations within the pipe in addition to the pressure profiles to obtain a better understanding of the complex behavior of the flow. The presence of screens normal to the flow was found to alter the fully developed parabolic profile and flatten it both upstream and downstream, hence simultaneously decelerating and accelerating regions in the cross-sectional area of the flow. Downstream of screens, the velocity profile was characterized by a sinusoidal shape that quickly decays, and vortices were observed under certain operating and design conditions. The study of the pressure field helped delineate the contribution of static and dynamic pressures in addition to identifying a minimum inter-screen distance if maximum pressure recovery is desired. Predictions of the pressure drop for various mesh geometries and under different operating conditions were validated using empirical correlations and the results reflected a very good accuracy with the maximum relative error falling within ± 7.3%. • 3D CFD simulations conducted to study the bounded laminar flow through wire mesh. • Pressure drop results were validated against published empirical correlations. • The flow was found three-dimensional near the wall while axial near the centerline. • The fully developed profile was drastically altered as it passes through the screen. • Different correlations for max/min velocities and pressure recovery were derived. [ABSTRACT FROM AUTHOR]

Abstract We study the effects of longitudinal magnetic field and temperature on the thermodynamic properties of two dimensional Heisenberg antiferromagnet on the honeycomb lattice in the presence of anisotropic Dzyaloshinskii-Moriya interaction and next nearest neighbor coupling exchange constant. In particular, the temperature dependence of specific heat have been investigated for various physical parameters in the model Hamiltonian. Using a hard core bosonic representation, the behavior of thermodynamic properties has been studied by means of excitation spectrum of mapped bosonic gas. The effect of Dzyaloshinskii-Moriya interaction term on thermodynamic properties has also been studied via the bosonic model by Green's function approach. Furthermore we have studied the magnetic field dependence of specific heat and magnetization for various anisotropy parameters. At low temperatures, the specific heat is found to be monotonically increasing with temperature for magnetic fields in the gapped field induced phase region. We have found the magnetic field dependence of specific heat shows a monotonic decreasing behavior for various magnetic fields due to increase of energy gap in the excitation spectrum. Also we have studied the dependence of magnetization on Dzyaloshinskii-Moriya interaction strength for different next nearest neighbor coupling constant. Highlights • The investigation of thermodynamic properties of quantum magnet on honeycomb lattice using Hard core bosonic transformation. • The study of the effect of magnetic field and Dzyaloshinskii Moriya interaction on specific heat of the compound. • The study of spin structure factors of the system in the presence of physical parameters. [ABSTRACT FROM AUTHOR]

This paper discusses the characteristics of liquid flow through tubular reactors/contactors equipped with woven mesh, screen-type static mixers from hydrodynamic and macromixing perspectives. The effect of changing the screen geometry, number of mixing elements, reactor configuration, and the operating conditions, were investigated by using four different screen types of varying mesh numbers. Pressure drop was measured over a wide range of flow rates (2300 ⩽ Re ⩽ 21,500) and was found to increase with a decreasing mesh opening. Friction factor values are also reported in the work, when compared to other types of motionless mixers, screen-type mixers were found to require much lower energy requirements with very low recorded Z values (1.15 ⩽ Z ⩽ 5) that are two to three orders of magnitude lower than those reported for other motionless mixers. Furthermore, residence time distribution experiments were conducted in the transitional and turbulent regimes (2300 ⩽ Re ⩽ 11,500). Using a deconvolution technique the RTD function was extracted in order to quantify the axial/longitudinal dispersion. The findings highlight that regardless of the number and geometry of the mixer, reactor configuration, and/or operating conditions, axial dispersion coefficients that are lower than those of an empty pipe were always recorded. The wire diameter and mesh opening were found to directly affect the axial dispersion in the reactor, while, the number of elements showed a minor effect. Furthermore, the choice of the characteristic parameter used to calculate the Reynolds number was found to be of paramount importance in analyzing the data. [ABSTRACT FROM AUTHOR]

We study the effects of longitudinal magnetic field and temperature on the thermodynamic properties of two dimensional Heisenberg antiferromagnet on the line-centered square lattice in the presence of anisotropic Dzyaloshinskii–Moriya interaction. We have studied the temperature dependence of specific heat and longitudinal magnetization of Lieb lattice for various physical parameters in the model Hamiltonian. Using a hard core bosonic representation, the behavior of thermodynamic properties has been studied by means of excitation spectrum of mapped bosonic gas. The effect of Dzyaloshinskii–Moriya interaction term on thermodynamic properties has also been studied via the bosonic model by exploiting Green's function approach. Furthermore we have studied the magnetic field dependence of specific heat and magnetization for various Dzyaloshinskii–Moriya coupling strength. At low temperatures, the specific heat is found to be monotonically increasing with temperature for magnetic fields in the gapped field induced phase region. We have found the magnetic field dependence of specific heat shows a monotonic decreasing behavior for various magnetic fields due to increase of energy gap in the excitation spectrum. Also we have studied the dependence of magnetization on Dzyaloshinskii–Moriya interaction strength for different magnetic field values. • The study of thermodynamic properties of Lieb lattice in the context of Heisenberg model. • The study the temperature dependence of specific heat of Lieb lattice. • The study of magnetization with spin orbit coupling. • The study of specific heat of Lieb lattice. [ABSTRACT FROM AUTHOR]

By careful searching of synthetic and observed spectra in a sample of cool giant and supergiant stars, we have updated the continuum band-passes of near-infrared Wing three filter system. This photometric system measures the strength of titanium oxide (TiO) absorption in Near-Infrared (NIR) at 719 nm. We show that new reference continuum band-passes are essentially free from molecular absorptions and the updated TiO-index defines the temperature variation in a sample of cool giants with less scatter. A TiO-index vs. effective temperature calibration is derived based on new continuum band-passes. [ABSTRACT FROM AUTHOR]

Abstract: The potential of using screen-type static mixers to intensify mass transfer limited multiphase-reactions was investigated using a case of diesel desulfurization. Two reactor designs were assessed at different superficial velocities and operating temperatures. By focusing energy dissipation within a very narrow distance in the regions adjacent to the screen, it was possible to generate local energy dissipation rates as high as 40,000W/kg while maintaining the specific energy consumption rates below 0.2kWh/t of liquid processed. Depending on the operating temperature, up to 15,400-fold reduction in the residence time needed to react 95% of the sulfur present in the diesel can be achieved by replacing a standard mixing tank agitated by a Rushton-type impeller with a screen-type static mixer. About 97% of this can be credited to the higher inter-phase mass transfer achievable in screen-type static mixers, while the remaining 3% can be attributed to the higher average mass transfer driving force encountered under the plug flow conditions prevalent in this contactor. The relatively uniform flow conditions encountered across the pipe diameter minimized the formation of difficult-to-separate liquid–liquid dispersions with the ensuing dispersion separating within 20s. [Copyright &y& Elsevier]

We study the thermal conductivity of a spin-1/2 two-dimensional anisotropic antiferromagnet on honeycomb lattice in the presence of antiferromagnetic long range ordering. The conductivity has been studied along zigzag direction. Next nearest neighbor exchange coupling has been added to the model Hamiltonian. The possible effects of spin–orbit coupling are investigated by adding Dzyaloshinskii–Moriya interaction to the model Hamiltonian. Such interaction creates anisotropic effects in the model Hamiltonian. The original antiferromagnetic model hamiltonian is mapped to a bosonic model via linear spin wave theory in the context of Holstein Primakoff transformations. The Green's function approach is applied to obtain the energy spectrum of quasi-particle excitations responsible for thermal transport. We have found the temperature dependence of static thermal conductivity in the magnetic long range ordering phase for various next nearest neighbor coupling constant and anisotropy parameter. Furthermore we have studied the temperature dependence of the static thermal conductivity for various Dzyaloshinskii-Moriya interaction strength and next nearest neighbor coupling constants. Our results show that each curve for temperature dependence of thermal conductivity includes a peak so that the height of peak reduces with magnetic field however the temperature positions of peaks is independent of magnetic field value. Moreover the increase of anisotropic parameter leads to enhance thermal conductivity values. Also the next nearest neighbor coupling constant improves thermal conductivity of localized electrons on honeycomb structure. The exponential behavior for temperature dependence of thermal conductivity at low temperatures is the novel feature in thermal conductivity results. • Study of thermal conductivity of honeycomb lattics. • Study of anisotropic parameter on conductivity. • Study of magnetic field effects on conductivity. [ABSTRACT FROM AUTHOR]

Background. Although androgen deficiency in men is associated with obesity, whether the deficiency is a consequence of the syndrome is still unclear. Aim. The aim of this study was to determine the association between low levels of sex hormones and development of the metabolic syndrome. Subjects and Methods. A total of 836 men, aged ? 20 years, participants of the Tehran Lipid Glucose Study, were assessed at baseline and after 6.5 years follow-up, based on both ATP III and IDF criteria for occurrence of metabolic syndrome. The association between serum total and free testosterone index and SHBG and metabolic syndrome was investigated using logistic regression models. Results. After 6.5 years of follow-up, the metabolic syndrome developed in 131 and 207 men based on ATP III and IDF criteria respectively. Multiple logistic regression analysis showed an inverse relationship for total testosterone in the lower tertile concentration, and serum triglycerides, according to both criteria mentioned (OR = 1.6; 95%CI 1.02-2.5). According to ATP III criteria, adjustment of waist circumference eliminated most of the correlations between total testosterone and metabolic syndrome (OR=1.34, 95% CI (0.8-2.3), while SHBG and free testosterone index were not significantly associated with the syndrome. According to IDF criteria, statistical adjustment of waist circumference eliminated most of the correlations between total testosterone and metabolic syndrome [(OR=1.45, 95% CI (0.9-2.3)], and adjustment with triglycerides eliminated all correlations between SHBG and metabolic syndrome (OR=1.5, 95% CI (0.9-2.5). Conclusions. Androgen deficiency may be related to poorly controlled serum triglycerides and increased waist circumference. [ABSTRACT FROM AUTHOR]

Abstract: A comparative evaluation of eight models used to predict the dispersed phase mass transfer coefficient was undertaken using recent drop size and mass transfer data obtained under well known and controlled hydrodynamic conditions encountered in screen-type static mixers. A wide range of experimental conditions were covered (ɛ =1.5–117W/kg, ϕ =0.1–0.47) thereby allowing for proper assessment of the strength and weaknesses of each model. All models failed to properly predict the experimental results over a wide range of design and operating conditions with the exception of those that contain a system-specific adjustable fitting parameter. Although these models yielded reasonably acceptable order-of-magnitude predictions, they could not accurately account for the variations in the different parameters investigated. This shows that proper understanding of the various factors affecting the dispersed phase mass transfer coefficient is still incomplete and highlights the need for phenomenological models that can account for the various physicochemical and hydrodynamic conditions on the dispersed-phase mass transfer coefficient. [Copyright &y& Elsevier]

Summary Objective Delivery of iodine to the foetus depends not only on maternal dietary iodine intake but also on the presence of a functioning placental transport system. A role for the placenta as an iodine storage organ has been suggested, and this study compares the iodine content of placentas from women giving birth at term in Ireland and Iran, areas with median urinary iodine of 79 and 206 μg/l respectively. Design Placental cotyledon iodine was measured using an alkaline ashing technique with Sandell-Kolthoff kinetic colorimetry. Samples were taken from six sites from the centre and periphery of each cotyledon. Placentas (Ireland n = 58; Iran n = 45) were obtained from consecutive euthyroid women delivering at term. Results The median placental iodine (μg/g wet weight) was significantly higher in Iranian than in Irish women (187·2 μg/g vs 34·3 μg/g; P < 0·001). The distribution of individual placental iodine values showed that values >50 μg/g were found in 71·0% of Iranian and in only 21·0% of Irish samples. In Irish subjects, the relationship of placental iodine to pregnant population urinary iodine (UI) (ng/g:μg/l) was 1:2 (40:79), while in Iranians this ratio is closer to 1:1 (211:206). Conclusions These findings, by demonstrating an apparent ability of the placenta to store iodine in a concentration-dependent manner, suggest a hitherto undetected role for the placenta. Whether placental iodine has a role in protecting the foetus from inadequacies in maternal dietary iodine intake is as yet unknown. [ABSTRACT FROM AUTHOR]

An approach for predicting the spatial variation of the energy dissipation rate downstream of a screen is proposed in this article. It is based on extending the use of the homogeneous and isotropic turbulence decay equation to the very thin anisotropic region adjacent to the screen. Whereas the decay exponent and origin were kept constant in conformity with other previous investigations, the decay coefficient was slightly altered. This approach was found to be capable of predicting the experimental energy dissipation data obtained using liquid flow through screens and screen-type static mixers reasonably well over a wide range of design and operating conditions. [ABSTRACT FROM AUTHOR]

Abstract: A successful attempt to simulate turbulently flowing liquid–liquid dispersions was undertaken in this work where the turbulent dispersion/coalescence of drops was accurately predicted over a wide range of operating conditions using the model developed by Coulaloglou and Tavlarides (1977) . Experimental data obtained from an intensified liquid–liquid reactor/contactor in which screen-type static mixers were used to superimpose an adjustable uniformly distributed turbulence field on the nearly plug flow conditions encountered in high velocity pipe flows were used to validate the model predictions. Drop size distribution and the Sauter mean diameter (when quasi-steady state conditions were assumed to be reached) were compared with the experimental results measured by photographic techniques and good agreement was obtained at different flow velocities and diverse screen geometries. The use of mutli-stage screen-type static mixers where alternating breakage-dominated and coalescence dominated regions exist allowed the development of accurate model parameters that may be used for simulating other more complex liquid–liquid contacting conditions such as those encountered in mechanically agitated tanks. [ABSTRACT FROM AUTHOR]

Abstract: Multiphase flows play an important role in the chemical and process industries and significant strides have recently been achieved in the design of such systems using the population balance models. However, some uncertainties still remain concerning the stability and accuracy of the numerical solution of such integro-differential equations. This paper proposes a new methodology for solving the discretized population balance equation by minimizing the finite domain errors that often arise while discretizing the drop size domain. It relies on the use of the size distribution sampling approach combined with a moving grid technique. In addition, an enhanced solution stability algorithm was proposed and which relies on monitoring the onset of errors in the various birth and death terms encountered in PBE. It consequently allows for corrective action to be undertaken before the errors propagate in an uncontrollable fashion, and was found to improve the stability and robustness of the solution method even under very high shear rate conditions. The proposed algorithm was tested using the model of under breakage and coalescence dominated conditions in low, moderate and high energy dissipation regions, and was found to provide a stable solution that accurately predicts the quasi-equilibrium Sauter mean diameter. [ABSTRACT FROM AUTHOR]

Lead is a relatively ubiquitous heavy metal with particular features such as resistance to corrosion, high malleability and wide variety of industrial applications. In medicine, however, it is considered as a slow-acting toxic substance affecting multiple body systems, specifically functioning as a potent neurotoxin in the central nervous system. Lead poisoning may be acute or chronic and can be due to occupational or environmental exposures. The history of lead poisoning dates back to ancient times. The present paper briefly describes the world- wide historical accounts of lead poisoning with a special focus on Iran. [ABSTRACT FROM AUTHOR]

Lead is a relatively ubiquitous heavy metal with particular features such as resistance to corrosion, high malleability and wide variety of industrial applications. In medicine, however, it is considered as a slow-acting toxic substance affecting multiple body systems, specifically functioning as a potent neurotoxin in the central nervous system. Lead poisoning may be acute or chronic and can be due to occupational or environmental exposures. The history of lead poisoning dates back to ancient times. The present paper briefly describes the world- wide historical accounts of lead poisoning with a special focus on Iran. [ABSTRACT FROM AUTHOR]

Abstract: The crystalline structure, grain morphology, electrical and electrochemical properties of Sr2−x La x FeMoO6 (x =0, 0.25, 0.5 and 1) double perovskite has been investigated by means of X-ray powder diffraction, scanning electron micrography, electrical and electrochemical measurements. It was found that the grain morphology, the resistivity and the electrochemical activity are strongly influenced by La doping. While the surface area as the determining factor in the oxygen reaction rate was excluded, the electrical resistivity was found to have a great effect on the electrochemical activity of the compounds. [Copyright &y& Elsevier]

Background: Obesity is a known risk factor for type 2 diabetes and its prevalence is increasing. The aim of this study was to examine the association between changes in body weight and body fat distribution and the subsequent risk of pre-diabetes and/or diabetes over a 3-year period among a population of Tehran Citizinery. Methods: A total of 3957 subjects aged 20 years and over, participants of the Tehran Lipid and Glucose Study, were included in this study. Demographic characteristics, plasma glucose in both the fasting state and two hours after 75gr oral glucose were measured at baseline (1998-1999) and after 3 years (2001-2002). Subjects were divided according to their baseline body mass index (BMI), weight changes (loss > 4%, loss or gain < 4%, 4-10% and > 10% weight gain), quintile of changes in waist circumference (WC) and waist to hip ratio (WHR) over the study period. The relative risk of developing pre-diabetes and/or diabetes was measured after adjustment for age, sex and family history of diabetes. Results: After three years of follow-up, 3.7% developed diabetes. Weight gain and baseline BMI were related to risk of developing pre-diabetes or diabetes in subjects with normal plasma glucose. Compared with subjects with stable weight, those who gained weight by 4-10% and >10% had 1.2 (1.01-1.53) and 1.3 (1.04-1.86) times the risk of pre-diabetes or diabetes, respectively after controlling for age, sex, family history of diabetes and BMI. In contrast, participants who lost >4% in weight, the relative risk decreased significantly [RR: 0.4 (0.27-0.65)]. These effects of weight changes were seen mostly in female subjects. Also, according to the baseline BMI, the risk increased in overweight and obese subjects by 1.7 (1.36-2.40) and 2.0 (1.55-2.63) times, respectively. Individuals with pre-diabetes at baseline, only BMI >/= 30 kg/m2 was associated with the increased risk of diabetes [ RR: 2.7 (1.49-4.78) ]. There was no relation between changes in WC or WHR and risk of developing abnormal glucose homeostasis after controlling for BMI and weight gain. Conclusion: Weight gain and BMI were independent risk factors in the development of abnormal glucose homeostasis. The data support public health recommendations to reduce the risk of diabetes by preventing weight gain and encouraging weight loss in overweight and obese people. [ABSTRACT FROM AUTHOR]

A successful attempt to simulate turbulently flowing gas–liquid dispersions was undertaken in this work where the turbulent dispersion/coalescence of bubbles was accurately predicted over a wide range of operating conditions by incorporating the effect of virtual mass into the phenomenological model developed by Coulaloglou and Tavlarides [1977. Description of interaction processes in agitated liquid–liquid dispersions. Chemical Engineering Science, 32, 1289–1297] for liquid–liquid dispersions. The population balance equation was numerically solved and the results obtained were compared with the experimental data obtained from an intensified gas–liquid reactor/contactor in which screen-type static mixers were used to superimpose an adjustable uniformly distributed turbulence field on the nearly plug flow conditions encountered in high velocity pipe flows. The model was also found to be capable of predicting gas–liquid contacting for the case of industrial streams where the presence of amphiphilic constituents was found to retard coalescence and result in average interfacial areas as high as 2100 being achieved. The fact that the model was capable to match experimental results obtained under very demanding/extreme conditions (where the flowing dispersion is successively exposed to breakage-dominated and coalescence dominated regions with local energy dissipation ratios as high as 400) suggests that it may be used for simulating other more complex gas–liquid contacting conditions such as those encountered in MAT. [Copyright &y& Elsevier]

Objective: To investigate the relationship between occupation and cardiovascular risk factors in women in Tehran. Study design and methods: A cross-sectional study of 566 working women and 561 age-matched housewives selected from among the 15 005 Tehran Lipid and Glucose Study (TLGS) participants. All cardiovascular risk factors were assessed. Results: The means of body mass index, waist circumference, waist to hip ratio, systolic and diastolic blood pressures, triglycerides and total cholesterol were significantly higher in housewives as compared to working women (P<0.05). Nine percent of working women and 17% of housewives had 4-6 cardiovascular risk factors; 1% of housewives had 7-8 cardiovascular risk factors. Conclusion: An increase in some cardiovascular risk factors was seen in housewives as compared to working women, and the percentage of housewives with 4-6 risk factors was found to be twice that of working women [ABSTRACT FROM AUTHOR]

Objectives: The menopause is associated with an increased incidence of coronary heart disease (CHD). Assessing CHD risk factors in menopausal women can shed more light on the pathogenesis of accelerated atherosclerosis after the cessation of ovarian function. Design: In this study, 1980 women aged 44-69 years were selected from among 15 005 participants in the Tehran Lipid and Glucose Study (TLGS) and assessed for CHD risk factors. They were classified into three groups: premenopausal women (n = 483), aged between 44 and 50 years, without any history of menstrual irregularities; menopausal women (n = 310), with permanent cessation of menses for at least 12 months and a duration of less than 3 years; and postmenopausal women (n = 1187), with at least a 3-year history of cessation of menses. Demographic information including waist size, height, weight and systolic and diastolic blood pressures was recorded, and body mass index, low-density lipoprotein/high-density lipoprotein ratio (LDL/HDL) and waist/hip ratio were calculated. Serum total cholesterol, triglycerides and HDL were measured and an oral glucose tolerance test was performed. The LDL level was calculated using the Friedwald formula. Results: Mean systolic blood pressures were 121 ± 18, 125 ± 20 and 136 ± 23 mmHg (p < 0.001) and mean diastolic blood pressures were 80 ± 10, 81 ± 11 and 82 ± 11 mmHg (p < 0.001) in premenopausal, menopausal and postmenopausal women, respectively. For premenopausal, menopausal and postmenopausal women, mean cholesterol levels were 215 ± 42, 238 ± 45 and 245 ± 46 mg/dl (p < 0.001), respectively. HDL and LDL levels were 44 ± 11, 48 ± 12 and 47 ± 11 mg/dl and 138 ± 38, 156 ± 41 and 161 ± 42 mg/dl (p < 0.001) for premenopausal, menopausal and postmenopausal women, respectively. Mean LDL/HDL ratios were 3.4 ± 1.4, 3.5 ± 1.3 and 3.6 ± 1.2 (p < 0.01) and mean waist measurements were 92 ± 11, 93 ± 12 and 95 ± 12 cm (p < 0.001) for the same groups of women, respectively. However, body mass index, waist/hip ratio and triglycerides showed no significant differences between the three groups. Conclusion: These data demonstrate an increase in CHD risk factors in a group of Tehranian women after the menopause. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine if systolic blood pressure (SBP) by itself is sufficient for the JNC-VI (Sixth Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure)-based classification of blood pressure of Tehranian adult population. Clinically, SBP and diastolic blood pressure (DBP) are sometimes at different stages in the same individual and the higher stage is considered to classify blood pressure level. The prevalence of disparate levels of SBP and DBP has only recently been noticed. Some researches have reported the importance of SBP level, and not DBP, in determining the appropriate classification of hypertension even in those undergoing treatment. Data were collected for 3823 men and 5159 women aged 20-69 years who were not using antihypertensive medication, in the Tehran Lipid and Glucose Study (TLGS), a cross-sectional phase of a large epidemiological study first established in 1999. The study used the mean of two separate blood pressure measurments in each individual. High blood pressure is defined according to the highest level of SBP or DBP. In 86.3% of the subjects, blood pressure stage was determined according to SBP and in 90.0% of them according to DBP. In 77.4% of the subjects (75.7% of men and 78.7% of women), SBP determined blood pressure in the same stage as DBP did. The role of SBP was the most prominent in age groups 20-29 and 60-69 years (91.4 and 90.8%, respectively) and the least in age group 40-49 years (80.4% of the subjects). DBP had a more prominent role in younger ages and the least significance in older ages. In conclusion, SBP has a more prominent role than DBP in determining blood pressure stage according to JNC-VI only in the 60-69-year-old group. The role of DBP is more prominent in other age groups.Journal of Human Hypertension (2003) 17, 287-291. doi:10.1038/sj.jhh.1001539 [ABSTRACT FROM AUTHOR]

The purpose of this study was to estimate the current prevalence and distribution of hypertension in an adult Tehranian population. Data were collected for 3343 men and 5148 women aged 20-69 years in the Tehran Lipid and Glucose Study (TLGS), which is a cross-sectional phase of a large epidemiologic study, first established in 1999. The study used the mean of two separate blood pressure (BP) measurements in each individual. Twenty-two percent (23% of women vs 20% of men, P = 0.01) had hypertension according to 'JNC-VI' and 'WHO-ISH' criteria. The average systolic BP (SBP), diastolic BP (DBP) and pulse pressure of hypertensive participants were 31, 16, and 15 mm Hg higher than the corresponding value for normotensives, respectively. Thirty-six percent of participants with JNCVI-based hypertension were using antihypertensive medication (23% of men and 43% of women). Of these, 40% (45% of men and 39% of women) had normal BP. Hypertension awareness was 50% in these participants (57% in men vs 37% in women, P < 0.001). Data for 3179 men and 4646 women aged 20-69 years with no antihypertensive treatment were used for analysis of BP measures. Of these, 15% (16% of men and 14% of women, P = 0.006) had high and 85% (84% of men and 86% of women) normal or high-normal BP levels according to JNC-VI. Prevalence of optimal BP was 49% (47% of men and 51% of women). Mean SBP was 117.8 ± 16.6 and 116.4 ± 16.4 mm Hg in men and women, respectively (P < 0.001). The equivalent values were 77.4 ± 10.7 and 77.3 ± 9.9 mm Hg for DBP (P = 0.5) and 40.4 ± 12 and 39.1 ± 11.7 mm Hg for pulse pressure (P < 0.001). A relatively high prevalence of JNC-VI/WHO-ISH defined hypertension was found in the TLGS adult population with 50% undiagnosed and 60% uncontrolled hypertension. These findings emphasise further considerations for detection and better management of hypertension in the urban population of Tehran. [ABSTRACT FROM AUTHOR]

We study the Ruderman-Kittle-Kasuya-Yosida (RKKY) interaction in doped both armchair and zigzag nanotubes. The effects of both gap parameter and electron doping on RKKY interaction have been addressed. RKKY interaction for traverse components of localized spins as a function of distance between localized moments has been analyzed. In order to calculate the exchange interaction along arbitrary direction between two magnetic moments, we should obtain transverse static spin susceptibility of graphene like nanotubes in the presence of gap parameter and electron doping. The spin susceptibility components are calculated using the spin dependent Green's function approach for tight binding model Hamiltonian. The effects of tube diameter on the dependence of exchange interaction on distance between moments are investigated via calculating correlation function of spin density operators. Our results show the influences of electron doping on the spatial behavior of transverse RKKY interactions are different for zigzag and armchair types of nanotube. • The study of RKKY interaction in carbon nanotubes using Green's function method. • The study of effects of tube dimater on RKKY interaction. • The study of chemical potential on RKKY interaction. [ABSTRACT FROM AUTHOR]

We present the behaviors of both dynamical and static charge susceptibilities of undoped armchair graphene nanoribbon using the Green's function approach in the context of Holstein model Hamiltonian. Specially, the effects of magnetic field and electron-phonon coupling strength on the plasmon modes of armchair graphene nanoribbon are investigated via calculating correlation function of charge density operators. Random phase approximation has been implemented to find the interacting dynamical charge susceptibility. The electrons in this systems interacts with each other by mediation of dispersionless Holstein phonons. Our results show the increase of electron phonon coupling strength leads to decrease intensity of charge collective mode. Also the frequency position of the collective mode tends to higher frequencies with electron phonon coupling. We also show that the frequency positions of plasmon mode of armchair nanoribbon are not affected by the increase of magnetic field. Furthermore the number of collective excitation mode increases with ribbon width in the presence of electron-phonon interaction. Finally the temperature dependence of static charge structure factor of armchair graphene nanoribbon is studied. The effects of magnetic field, ribbon width and electron-phonon interaction on the static structure factor are addressed in details. [ABSTRACT FROM AUTHOR]

We have theoretically studied the spin structure factors of Heisenberg model on honeycomb lattice in the presence of longitudinal magnetic field, i.e. magnetic field perpendicular to the honeycomb plane, and Dzyaloshinskii-Moriya interaction. The possible effects of next nearest neighbor exchange constant are investigated in terms of anisotropy in the Heisenberg interactions. This spatial anisotropy is due to the difference between nearest neighbor exchange coupling constant and next nearest neighbor exchange coupling constant. The original spin model hamiltonian is mapped to a bosonic model via a hard core bosonic transformation where an infinite hard core repulsion is imposed to constrain one boson occupation per site. Using Green's function approach, the energy spectrum of quasiparticle excitation has been obtained. The spectrum of the bosonic gas has been implemented in order to obtain two particle propagator which corresponds to spin structure factor of original Heisenberg chain model Hamiltonian. The results show the position of peak in the dynamical transverse spin structure factor at fixed value for Dzyaloshinskii Moriya interaction moves to higher frequency with magnetic field. Also the intensity of dynamical transverse spin structure factor is not affected by magnetic field. However the Dzyaloshinskii Moriya interaction strength causes to decrease the intensity of dynamical transverse spin structure factor. The increase of magnetic field does not varied the frequency position of peaks in dynamical longitudinal spin susceptibility however the intensity reduces with magnetic field. Our results show static transverse structure factor is found to be monotonically decreasing with magnetic field and temperature for different values of next nearest neighbor coupling exchange constant. • The study of structure factors of Heisenberg model on honeycomb lattice using hard core bosonic transformation. • Using Green's function for finding excitation spectrum of the model. • The study of hard core repulsion effects on the properties of bosonic gas. [ABSTRACT FROM AUTHOR]

We present the behaviors of both dynamical and static charge susceptibilities of undoped armchair graphene nanoribbon using the Green's function approach in the context of Holstein model Hamiltonian. Specially, the effects of magnetic field and electron-phonon coupling strength on the plasmon modes of armchair graphene nanoribbon are investigated via calculating correlation function of charge density operators. Random phase approximation has been implemented to find the interacting dynamical charge susceptibility. The electrons in this systems interacts with each other by mediation of dispersionless Holstein phonons. Our results show the increase of electron phonon coupling strength leads to decrease intensity of charge collective mode Also the frequency position of the collective mode tends to higher frequencies with electron phonon coupling. We also show that the frequency positions of plasmon mode of armchair nanoribbon are not affected by increase of magnetic field. Furthermore the number of collective excitation mode increases with ribbon width in the presence of electron-phonon interaction. Finally the temperature dependence of static charge structure factor of armchair graphene nanoribbon is studied. The effects of both magnetic field, ribbon width and electron-phonon interaction on the static structure factor are addressed in details. • The study of dynamical spin susceptibility of graphene nanoribbon. • The study of static transverse spin susceptibility of graphene nanoribbon in the presence of Electron phonon coupling.. [ABSTRACT FROM AUTHOR]

Background and Objective: Insulin resistance (IR) is one of the factors affecting dyslipidemia in type 2 diabetes which increases the risk of cardiovascular diseases. This study was done to determine the association of homeostasis model assessment of insulin resistance with lipid profiles in type 2 diabetes. Methods: This descriptive study was conducted on 72 patients with type 2 diabetes in Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran during 2011. Anthropometric indces, fasting serum glucose, serum insulin and lipid profiles were measured and IR index and atherogenic lipid parameters were calculated. The mean of lipid profiles and parameters were compared across the IR tertiles. The association of homeostasis model assessment and insulin resistance in each tertile with lipid profiles was determined. Results: The mean±SD of IR index was 0.9±0.3, 2.1±0.4 and 4.4±1.6 in the 1th, 2th and 3th tertiles, respectively. In the 3th tertile, serum triglyceride and atherogenic lipid parameters were significantly high and serum HDL-C level was non-significantly low than normal reference range. IR index in the 2th and 3th tertiles was significantly related to serum Triglyceride (P<0.05). IR index in level of >2.8, was inversely associated with HDL-C and directly associated with atherogenic lipid parameter. Conclusion: There is association between Insulin resistance with lipid metabolic abnormality in type 2 diabetic patients. [ABSTRACT FROM AUTHOR]

Approximately ninety two years ago, the worst influenza pandemic or 'Spanish flu' occurred in 1918, at the end of the First World War (WWI, 1914-1918) which resulted in the deaths of millions of people worldwide. The death toll exceeded the total number of victims of WWI. The 1918 Spanish flu was a deadly, major global event that affected many countries, including Iran. In Iran, it was accompanied by a high mortality rate estimated to be more than one million. However, detailed information on the impact of this outbreak in Iran is scarce. The present paper describes a brief history of the influenza pandemics in the world as well as the spread of the 1918 Spanish flu to Iran. [ABSTRACT FROM AUTHOR]

Purple kernel streaking (PKS) in white food corn (Zea maya L.) is characterized by the accumulation of purple-pigmented streaks (anthocyanins) in an otherwise colorless pericarp. This paper is the first published report documenting PKS, the prevalence of the trait in commercial white food corn germplasm, and the genetics underlying it. Entries from the Early White Food Corn Performance Trials were grown in Ontario over a three-year period and rated for incidence of PKS and days to flower. All commercial hybrids entered were genetically predisposed to PKS with severity varying across years and entries, and not consistently related to hybrid maturity. Quantitative trait locus (OTL) mapping was used to identify the genomic regions influencing PKS expression in an F2:3 population derived from the cross of two white food corn inbred lines, SD79 and SD80. PKS exhibited significant genotype x year interaction. OTLs were identified for each year explaining 64 and 46% of the phenotypic variation, with only one single-effect and one two-way interaction common across the two years. Linkage of the main single-effect OTL with the y1 gene, coupled with the G×E effects, may explain the prevalence of PKS in commercial white food corn hybrids. [ABSTRACT FROM AUTHOR]

Objective: To compare the ability of waist circumference (WC), body mass index (BMI), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) to predict cardiovascular risk factors in an urban adult population of Tehranian women.Design: Population-based cross-sectional study.Setting: Tehran, the capital of Iran.Subjects: This study was conducted on 5073 women aged 18-74 years, participants of the Tehran Lipid and Glucose Study. Demographic data were collected. Anthropometric indices were measured according to standard protocols. Cut-off points of BMI, WC, WHR and WHtR were considered as 25 kg m(-2), 80 cm, 0.8 and 0.5, respectively. Blood pressure was measured and hypertension was defined based on the sixth report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. Biochemical analyses were conducted on fasting blood samples. Diabetes was defined as fasting plasma glucose > or = 126 mg dl(-1) or 2-hour plasma glucose > or = 200 mg dl(-1) and dyslipidaemia based on the third report of the National Cholesterol Education Program Expert Panel. The presence of 'at least one risk factor' from the three major cardiovascular risk factors (hypertension, dyslipidaemia and diabetes) was also evaluated.Results: Mean (+/-standard deviation) age of women was 39.9+/-14.6 years; mean BMI, WC, WHR and WHtR were 27.1+/-1.5 kg m(-2), 86.5+/-13.5 cm and 0.83+/-0.08 and 0.55+/-0.08, respectively. Of the four anthropometric measures, WC had the highest sensitivity and specificity to identify subjects with risk factors in both the 18-39 year and the 40-74 year age categories. WC was seen to have a higher percentage of correct prediction than BMI, WHR and WHtR.Conclusion: It is concluded that WC is the best screening measure for cardiovascular risk factors, compared with BMI, WHR and WHtR, in Tehranian adult women. [ABSTRACT FROM AUTHOR]

Abstract: A novel static mixer design (screen-type elements) capable of taking advantage of the interfacial characteristics of industrial gas/liquid systems was developed. The interfacial area of contact, and volumetric oxygen transfer coefficient, were investigated using a 25.4mm pipe loop in which liquid superficial velocities of up to 2.0m/s (and gas holdups as high as 0.15) were tested. Volumetric mass transfer coefficients as high as were achieved. The ability of this design to achieve high energy utilization efficiencies is validated by achieving oxygen transfer rate as high as 4.2kg/kWh in the presence of surfactants. Depending on the process requirements and the interfacial properties of the system, high volumetric oxygen transfer coefficients or high energy utilization efficiencies can be achieved by modifying the contactor design and/or operating conditions. [Copyright &y& Elsevier]

OBJECTIVE:Assessing overall diet instead of the effects of a single nutrient on diet–disease relations may be more informative. This study was conducted to evaluate the relationship between dietary diversity score (DDS) and metabolic syndrome in Tehranian adults.DESIGN:Cross-sectional study.SUBJECTS:A representative sample of 581 healthy subjects aged over 18 y selected randomly from among participants of the Tehran Lipid and Glucose Study.MEASUREMENTS:Usual dietary intake was assessed using a validated semi quantitative food frequency questionnaire. DDS was calculated based on scoring to the five-food group. The DDS range was 0–10. Weight and height were measured according to standard protocols and body mass index (BMI) was calculated. Fasting blood samples were taken for biochemical measurements and blood pressure was assessed according to standard methods. Metabolic syndrome was defined according to ATPIII. Subjects were categorized based on quartile cut-points of DDS.RESULTS:Means (±s.d.) of age and BMI were 37±12 y and 25.7±4.3 kg/m2, respectively. Mean (±s.d.) of DDS was 6.15±1.02. The probability of having metabolic syndrome decreased with quartiles of DDS (odds ratios among quartiles: 1.00, 0.82, 0.76, 0.70, P<0.05, and odds ratios among quartiles after further adjustment for BMI: 1.00, 0.88, 0.80, 0.77, P<0.05). After controlling for confounders, a significantly decreasing trend was observed for the risk of having high blood pressure, impaired glucose homeostasis and high triglyceride levels.CONCLUSION:DDS had inverse association with metabolic syndrome and some of its features in this cross-sectional study. A higher dietary diversity, therefore, might be associated with lower possibility of having some metabolic disorders.International Journal of Obesity (2005) 29, 1361–1367. doi:10.1038/sj.ijo.0803029; published online 23 August 2005 [ABSTRACT FROM AUTHOR]

Objective:To examine the relationship between variety scores of food groups (between and within food groups) and the probability of nutrient adequacy in Tehranian men.Design:A cross-sectional study assessing food intake by two 24-h recall questionnaires. Dietary diversity was defined according to diet quality index revised, which was used by Haines et al in 1999. The mean probability of adequacy across 14 nutrients was calculated using the Dietary Reference Intakes.Setting:District 13 of Tehran, Iran.Subjects:A total of 295 males, aged 18 y and over.Results:Whole grain variety mostly correlated with protein and vitamin B2 (r=0.3, P<0.05). Fruit variety was correlated with vitamin C (r=0.4, P<0.05). Dairy variety was correlated with calcium intake (r=0.4, P<0.05). Meat variety was correlated with protein intake (r=0.3, P<0.05). Most subjects failed to meet vitamin B6, zinc, magnesium, calcium, copper, and vitamin B12 adequacy. Energy intake was a strong predictor of the mean probability of adequacy in models controlled for age, body mass index, education level and job status (model R2=0.48). Adding the number of servings from each of the food group to the models significantly improved the model fit (model R2=0.55). Adding the dietary variety improved the model fit significantly (model R2=0.61). Dairy variety and meat variety had the strongest association with improved nutrient adequacy.Conclusion:Variety of different food groups is a useful indicator of specific nutrient adequacy. Hence, to determine the adequacy of a specific nutrient, the variety scores of specific food groups should be taken into account.European Journal of Clinical Nutrition (2005) 59, 1233–1240. doi:10.1038/sj.ejcn.1602234; published online 13 July 2005 [ABSTRACT FROM AUTHOR]

BACKGROUND:: Although dietary guidelines recommend increased intake of grain products to prevent chronic diseases, epidemiologic data regarding whole-grain intake association with metabolic syndrome are sparse. OBJECTIVE:: To evaluate the relationship between whole-grain intakes, metabolic syndrome and metabolic risk factors in Tehranian adults. DESIGN:: Population-based cross-sectional study. SETTING:: Tehran, the capital of Iran. SUBJECTS:: A representative sample of 827 subjects (357 men and 470 women) aged 18-74?y. METHODS:: Usual dietary intake was assessed using a food frequency questionnaire. The procedure developed by Jacobs et al was used to classify grain products into whole and refined grains. Weight and height were measured according to standard protocols and body mass index was calculated. Fasting blood samples were taken for biochemical measurements and blood pressure was assessed according to standard methods. Hypertriglyceridemia, hypercholestrolemia, high LDL, low HDL and metabolic syndrome were defined according to ATP III guidelines and hypertension based on JNC VI. Diabetes was defined as fasting plasma glucose level of=126?mg/dl or 2-h postchallenge blood glucose level of=200?mg/dl. Subjects were categorized based on quartile cut-points of whole- and refined-grain intake. RESULTS:: Mean (±s.d.) consumptions of whole and refined grains were 93±29 and 201±57?g/day, respectively. Both men and women reported higher intakes of refined grain than of whole grains. Compared with subjects in the lower quartile category, those in the upper category of whole-grain intake had lower prevalence of metabolic risk factors. Conversely, those in the higher category of refined-grain intake had higher prevalence of metabolic risk factors, except for diabetes. After controlling for confounders, a significantly decreasing trend was observed for the risk of having hypertriglyceridemia (odds ratios among quartiles: 1.00, 0.89, 0.74, 0.61, respectively), hypertension (1.00, 0.99, 0.93, 0.84) and metabolic syndrome (1.00, 0.84, 0.76, 0.68). Higher consumption of refined grains was associated with higher odds of having hypercholestrolemia (1.00, 1.07, 1.19, 1.23), hypertriglyceridemia (1.00, 1.17, 1.49, 2.01), hypertension (1.00, 1.22, 1.48, 1.69) and metabolic syndrome (1.00, 1.68, 1.92, 2.25). CONCLUSION:: Whole-grain intake is inversely and refined-grain intake is positively associated with the risk of having metabolic syndrome. Recommendations to increase whole-grain intake may reduce this risk. SPONSORSHIP:: Endocrine Research Center, Shaheed Beheshti University of Medical Sciences.European Journal of Clinical Nutrition (2005) 59, 353-362. doi:10.1038/sj.ejcn.1602080 Published online 10 November 2004 [ABSTRACT FROM AUTHOR]

OBJECTIVE:: To assess the relationship between consumption of dairy products and body mass index (BMI) in Tehranian adults. DESIGN:: Cross-sectional study. SUBJECTS:: A total of 462 healthy subjects (223 men and 239 women) aged over 16?y selected randomly from among participants of the Tehran Lipid and Glucose Study (TLGS). MEASUREMENTS:: Dietary data were collected by means of a food frequency questionnaire for 1?y and two 24-h dietary recalls. Height and weight were measured and BMI was calculated. Physical activity was assessed by the Lipid Research Clinic (LRC) questionnaire. RESULTS:: Consumption of dairy products was 3.7±1.0 and 2.9±1.2 servings per day in men and women, respectively. As the servings of dairy consumption increased per day, the proportion of normal-weight subjects rose and that of obese ones declined. As BMI increased, the proportion of subjects with lower consumption of dairy products increased, whereas that of those with higher consumption decreased. There was a significant inverse correlation between the servings of dairy consumption per day and BMI after controlling for the effect of age, physical activity, energy, carbohydrate, dietary fiber, protein and fat intake (r=-0.38, P<0.05). After adjustment for potential confounding variables, men and women in the top quartile of dairy consumption had lower chances for being overweight (OR=0.78, 95%CI=0.43-0.92 for men and OR=0.89, 95%CI=0.53-0.95 for women) and obese (OR=0.73, 95%CI=0.40-0.83 for men and OR=0.69, 95%CI=0.34-0.80 for women) compared to those in the first quartile. CONCLUSION:: The results suggest an inverse relationship between dairy consumption and BMI. It is recommended that further studies address this issue by focusing on the dairy components responsible for this effect.International Journal of Obesity (2005) 29, 115-121. doi:10.1038/sj.ijo.0802838 Published online 9 November 2004 [ABSTRACT FROM AUTHOR]

BACKGROUND: It is essential to identify the best anthropometric index in any population to predict chronic disease risk. OBJECTIVE: To compare the ability of waist circumference (WC), body mass index (BMI), waist-to-hip ratio (WHpR) and waist- to-height ratio (WHtR) to predict cardiovascular risk factors in an urban adult population of Tehranian men. DESIGN: Population-based cross-sectional study. SUBJECTS: A representative sample of 4449 men aged 18–74y, participants of the Tehran Lipid and Glucose Study METHODS: Demographic data were collected; anthropometric indices and blood pressure were measured according to standard protocol. In the 18–34y age category, cutoff points for BMI, WHpR, WHtR and WC were 24kg/m2, 0.86, 0.47 and 81 cm, respectively. In the 35–54y age category these cut points were 26kg/m2, 0.91, 0.52 and 89cm, and in the 55–74y age category 26kg/m2, 0.95, 0.54 and 91 cm, respectively. Hypertension was defined based on JNC VI. Biochemical analysis was conducted on fasting blood samples. Diabetes was defined as fasting plasma glucose ≥126mg/dl or 2hPG >200mg/dl and dyslipidemia based on ATP III. The presence of ‘at least one risk factor’ from the three major cardiovascular risk factors (hypertension, dyslipidemia and diabetes) was also evaluated. RESULTS: Mean age of men was 41.8±15.4y. Mean BMI, WHpR, WC and WHtR for subjects were 25.6±4.2kg/m2, 0.91 ±0.07, 87.7±11.7cm and 0.51 ±0.02, respectively. Dyslipidemia and ‘at least one risk factor’ are more prevalent risk categories. Although all anthropometric indicators had a significant association to cardiovascular risk factors, WHpR had the highest correlation coefficients compared to other anthropometric measures. For all risk factors in all age categories, the highest odds ratios were pertained to WHpR. Of the four individual indicators, WHpR had the highest sensitivity, specificity and accuracy to predict cardiovascular risk factors. Cutoff points for WHpR were seen to have a higher percentage of correct prediction than BMI, WC and WHtR in all age categories. CONCLUSION: It is concluded that WHpR is a better predictor for cardiovascular risk factors than BMI, WC and WHtR in Tehranian adult men. [ABSTRACT FROM AUTHOR]

OBJECTIVE:: To determine optimal cutoff points of anthropometric measures as cardiovascular indicators in an Iranian adult population. DESIGN:: Population-based cross-sectional study. SETTING:: Tehran, the capital of Iran. SUBJECTS:: A total of 10?522 subjects (4449 men and 6073 women) aged 18-74?y. METHODS:: Demographic data were collected and anthropometric indices were measured. Blood pressure was evaluated and hypertension was defined based on JNC VI. Biochemical measurements were done. Diabetes was considered as FBS=126?mg/dl (=7.0?mmol/l) and dyslipidemia was defined according to ATP II. Risk factors were considered as: hypertension, diabetes, dyslipidemia, ‘hypertension or diabetes’, ‘hypertension and diabetes’, ‘hypertension or dyslipidemia’, ‘hypertension and dyslipidemia’, ‘ diabetes or dyslipidemia’, ‘diabetes and dyslipidemia’, ‘at least one risk factor’ and ‘at least two risk factors’. ROC curve analysis was performed to determine optimal cutoff values-where the sensitivity approximates specificity. RESULTS:: Younger men (the age category of 18-34?y) had higher WC than women. Men had higher waist-to-hip ratio (WHpR) and lower waist-to-height ratio (WHtR) than women in all age categories. Dyslipidemia, ‘hypertension or dyslipidemia’, ‘diabetes or dyslipidemia’ and ‘at least one risk factor’ were more prevalent risk categories in both genders. Range of areas under ROC curves for BMI and WC was 0.55-0.94 and 0.56-0.93 for men and 0.41-0.94 and 0.53-0.92 for women in various age groups, respectively. Range of areas for WHpR and WHtR in men was between 0.58-0.87 and 0.56-0.94, respectively, and for women varied between 0.53-0.91 and 0.53-0.90 in various age groups, respectively. Cutoff points of BMI for various risk factors were between 24 and 29?kg/m2 in men and 25-31?kg/m2 in women. Range of WHpR was between 0.86 and 0.97 in men and between 0.78 and 0.92 in women. Cutoff points for WC and WHtR were between 80 and 93?cm and 0.47 and 0.56 for men and between 79 and 96?cm and 0.50 and 0.63 for women in different age groups to detect various risk factors, respectively. In general, values were lowest for the most prevalent risk factors and highest for less prevalent conditions. CONCLUSION:: The results suggested cutoff points of anthropometric measures as indicators of cardiovascular risk factors. It seems that these cut-points are higher for Iranians than for other Asian populations. SPONSORSHIP:: Endocrine Research Center, Shaheed Beheshti University of Medical SciencesEuropean Journal of Clinical Nutrition (2004) 58, 1110-1118. doi:10.1038/sj.ejcn.1601936 [ABSTRACT FROM AUTHOR]

OBJECTIVE:: To clarify the hypothesis that parent's dietary intakes are associated with their offspring's body mass index. DESIGN:: Observational analytical cross-sectional survey among inhabitants of district 13 in the east of Tehran. SUBJECTS:: A total of 117 healthy families comprising 474 subjects including 240 offspring (3–25 y old). MEASUREMENTS:: Weight and height were measured by a standard protocol and body mass index (kg/m2) was calculated. Dietary intakes were assessed by means of a 2 day dietary recall questionnaire. RESULTS:: The prevalence of overweight was 11.8% in offspring of normal-weight parents, 19.0% in offspring of overweight fathers and normal-weight mothers, 25.4% in offspring of overweight mothers and normal-weight fathers and 40.8% in offspring with both parents overweight. The Offspring's overweight was significantly and independently associated with high-energy intake of both parents (odds ratio; 95% CI 2.7; 1.6–4.5). Adjusted for the sex of parents, the chances of offspring being overweight were higher in overweight (3.8; 1.5–9.2) and high-energy-intake mothers (2.6; 1.2–5.6) and high-energy-intake fathers (2.0; 1.1–3.9) as compared with children of normal-weight parents. High fat intake of husbands was an independent risk factor increasing the chances of their wives being overweight (2.1; 1.5–3.6) and vice versa (1.8; 1.2–2.8). CONCLUSION:: The observed familial obesity pattern was shown to be associated with the familial dietary intakes. Hence, familial intervention seems essential to stop the accelerated rise in the prevalence of overweight and obesity in our community.International Journal of Obesity (2002) 26, 1617–1622. doi:10.1038/si.ijo.0802120 [ABSTRACT FROM AUTHOR]

To examine the association between educational level and chronic kidney disease (CKD) among the Iranian population. This is a prospective cohort study conducted in the framework of the Tehran Lipid and Glucose Study. A total of 8173 Iranians (men = 3659) aged ≥20 years were included in the study. CKD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. The association between educational status and CKD was explored using multivariate Cox proportional regression analyses, adjusted for age, gender, current smoking, marital status, body mass index, waist circumference, baseline eGFR, diabetes, hypertension, physical activity, history of cardiovascular diseases and dyslipidaemia. During a median follow-up of 13.14 years, 2609 cases of incident CKD were identified; the corresponding incidence rate was 26.35 (range 25.39–27.34) per 1000 person-years. Compared to low educational level, middle and high educational levels showed lower risks for incident CKD in the crude model [hazard ratio (HR) 0.37 (95% confidence interval {CI} 0.34–0.40) and HR 0.40 (95% CI 0.35–0.45), respectively]; however, these HRs changed direction after further adjustment for age and gender [HR 1.26 (95% CI 1.14–1.39) and HR 1.40 (95% CI 1.22–1.61), respectively]. The increased risk of incident CKD for those at higher educational levels remained significant in the fully adjusted model. In addition, results from the gender stratified analyses were in the same direction as those found among the whole study population (P -value for interaction of gender and education >0.8). Higher educational levels were associated with incident CKD during more than a decade of follow-up; this finding may be attributed to unhealthy lifestyle behaviours among this population group. [ABSTRACT FROM AUTHOR]

To investigate the incidence rates for different malignancies and assess the risk factors for all-cancer incidence in Tehran. Cohort study. This study consists of 8599 participants aged ≥ 30 years who were free of cancer (3935 men). Cancer diagnosis was based on pathology reports. Sex-stratified crude incidence rates and age-standardized incidence rates (ASRs) using Segi's method were calculated for all-cancers. Multivariate Poisson regression models were used to evaluate associations of potential risk factors, including sex, age, obesity status (body mass index [BMI]: 25–30 kg/m2 as reference), education, smoking status, and diabetes mellitus with the incidence of cancers among the population. Incidence rate ratios (IRRs) with 95% confidence interval (CI) were also reported. During a median follow-up of 13.9 years, there were 130 and 129 incident cancers for men and women, respectively; the corresponding ASRs were 356.1 and 243.6 per 100,000 person-years, respectively. The three most incident cancers among men were gastrointestinal (GI) (ASR = 127.5), hematopoietic (ASR = 99.5), and reproductive system malignancies (ASR = 46.3). The most common incident cancers in women were breast cancer (ASR = 92.1), GI (ASR = 65.4), and reproductive system malignancies (ASR = 16.8). Among risk factors for cancer incidence, age (IRR [95% CI]: 1.05 [1.03–1.06]) and having a BMI < 25 kg/m2 (IRR [95% CI]: 1.38 [1.01–1.90]) had a statistically significant association with incident cancer. The high rates of cancers in Tehran during more than a decade of follow-up calls for a need to define risk factors as well as to implement programs for early screening. • The age-standardized rate was 356.1 per 100,000 person-years in men during 14 years. • The age-standardized rate was 243.6 per 100,000 person-years in women during 14 years. • Gastrointestinal and hematopoietic were the two most incident cancers among men. • Breast and gastrointestinal were the two most incident cancers among women. [ABSTRACT FROM AUTHOR]

Background: The association between low testosterone concentration and increased risk of hyperglycemia in men has been demonstrated in observational and interventional studies. However, considering a variety of confounding factors, limited population‐based studies have so far been conducted. Also, no information is available regarding the effect of testosterone on progressive development of dysglycemia. Objective: To examine the effect of total testosterone on development of pre‐diabetes/diabetes in normoglycemic middle‐aged and older men. Materials and Methods: Data were obtained from the Tehran Lipid and Glucose Study, a community‐based prospective cohort of an Iranian population. Analyses were conducted on 903 normoglycemic eligible men aged 30–70 years. An illness‐death model was applied to estimate the probabilities of three transitional phases of normoglycemia→diabetes, normoglycemia→pre‐diabetes, and pre‐diabetes→diabetes. Results: Over a median follow‐up of 12 years, 0.9% individuals developed diabetes. Per unit increase (ng/mL) in testosterone concentration, the transition rate from normoglycemia to pre‐diabetes decreased by 6% [hazard ratios (HRs): 0.94 (95% confidence interval (CI): 0.90, 0.99)]. However, no effect for testosterone on the progression of diabetes from normoglycemia or pre‐diabetes was observed [HRs: 0.79 (95% CI: 0.44, 1.41) and 0.98 (95% CI: 0.84, 1.16), respectively]. High body mass index was a strong predictor of hyperglycemia within all transitions. Discussion: Independent of major confounding factors, low testosterone was associated with normoglycemia progression to pre‐diabetes, but not with pre‐diabetes to diabetes, which might indirectly highlight the stronger impact of other risk factors after occurrence of pre‐diabetes. Conclusion: Low testosterone concentrations in men are associated with progression from normoglycemia to pre‐diabetes, but not from pre‐diabetes to diabetes. [ABSTRACT FROM AUTHOR]

Summary: Background: Current evidence available on the association between Dietary Approach to Stop Hypertension (DASH) diet and cardiovascular risk in adolescents is controversial. Objective: The aim of the present study was to assess the association between DASH diet and cardiovascular risk factors after 3 years of follow‐up among Tehranian adolescents. Methods: A population‐based cohort study was conducted on 628 subjects, aged 10–18 years, selected from among participants of the Tehran Lipid and Glucose Study. The DASH score was determined on the basis of eight components using a valid and reliable food‐frequency questionnaire at baseline. Anthropometric and lipid profile data were measured at baseline and after a 3‐year follow‐up. Results: Mean (SD) age of the study population (46.6% men) was 14.1 (2.5) years. After adjustment for potential confounding variables, including sex, age, physical activity and total calorie intake, the risk of general obesity (OR = 0.26, 95%CI: 0.15–0.76) and central obesity (OR = 0.32, 95%CI: 0.14–0.84) in the highest quintile of DASH score were significantly lower than in subjects in the lowest quintile. However, DASH score was not associated with risk of incident dyslipidaemia in our study (OR = 0.81, 95%CI: 0.30–1.82). The higher DASH score was inversely associated with 3‐year changes in body mass index and waist circumference during the study period (P for trend <0.05). However, there was no significant association between the higher score of this diet with 3‐year changes in lipid profiles. Conclusion: Adherence to the DASH diet was associated with decreased risk of central and general obesity, whereas higher DASH diet score was not associated with risk of dyslipidaemia in adolescents. [ABSTRACT FROM AUTHOR]

Objective: Considering the role of anti-Müllerian hormone (AMH) in female fertility and its high levels in women with polycystic ovary syndrome (PCOS), the longer reproductive span of these women is in doubt. In the present study, we aimed to improve earlier predictions using a non-linear model to substantiate the question as to whether PCOS women reach menopause later.Methods: In total, 1162 women aged 20-50 years, comprising 378 PCOS cases and 784 eumenorrheic non-hirsute women, met the eligibility criteria. A scatterplot matrix was drawn to detect the association between age and AMH; this association was explored using a fractional polynomial regression model. Model assumptions were checked by examining the distribution of the residuals and plotting the standardized residuals against the functional form of AMH.Results: The serum concentration of AMH among PCOS participants was significantly higher than in the controls (5.4 ng/ml (IQR 2.8-9.1 ng/ml) vs. 1.4 ng/ml (IQR 0.6-2.7 ng/ml), p < 0.001). The estimated mean age at menopause was 51.4 (95% CI 45-59) years and 49.7 (95% CI 45-55) years in PCOS cases and healthy controls, respectively.Conclusions: These findings provide the insight that, as reflected through significantly higher average levels of AMH in PCOS women, their predicted reproductive lifespan could be 2 years longer than their normo-ovulatory counterparts. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to assess the prevalence and incidence and predictive factors of thyroid disorders (TD) in patients with impaired glucose metabolism. Methods: Prevalence of TD was calculated in patients with impaired glucose metabolism compared to healthy controls, aged over 30 years in phase 1 of the Tehran Thyroid Study (TTS). Follow up assessments were conducted every 3 yrs, after which incidence of TD was calculated and its correlations with age, sex, smoking, blood pressure, body mass index (BMI), thyroid peroxidase antibody (TPOAb), thyrotropin (TSH), insulin resistance index, triglycerides and cholesterol were assessed. Results: Incidence of TD among 435 diabetics, 286 prediabetics, and 989 healthy controls at baseline was 14, 18, and 21 per 1000 patients per year, respectively, being significantly lower in diabetics than that in healthy controls, a difference however that was not significant after adjusting for the variables mentioned (OR:0.64, 95% CI: 0.39–1.01). The incidence of TD in subjects with baseline serum TSH>1.94 mU/L or TPOAb≥40 IU/ml in all three groups was higher than that in patients with TSH≤1.94 mU/L or TPOAb<40 IU/ml, and remained significant after variable adjustment. Baseline TSH>1.94 mU/L was predictive of TD with 70% sensitivity and specificity. Baseline serum TSH (ROC area: 0.73, 95% CI: 0.68–0.77) had better predictive value than TPOAb (ROC area: 0.65, 95% CI: 0.61–0.69) for developing TD. Conclusion: Incidence of TD in type 2 diabetics or prediabetics is not higher than healthy controls. It is however necessary to conduct thyroid tests in patients with TPOAb≥40 IU/ml or TSH>1.94 mU/L. [ABSTRACT FROM AUTHOR]

Introduction: The ovaries produce female sex hormones that after natural menopause gradually and following surgical menopause abruptly end. Materials and Methods: The study subjects were selected from 5019 women, 59-35 years old, which were participated in the Tehran Lipid and Glucose Study. They include 357 natural menopauses and 63 surgical menopauses during the follow-up that was 10 years. Data were collected by questionnaires in this project. Results: Changes in metabolic and biochemical profiles of these two groups of women during follow-up were compared with each other. The findings of our study showed that the incidences of metabolic syndrome in surgical menopause and natural menopause subjects were 14.5 and 8.9% respectively. Mean serum low density lipoprotein in surgically menopausal women was significantly lower than natural menopause subjects. Also, mean systolic blood pressure in naturally menopausal women was significantly higher than surgical menopause women. Conclusion: It seems the metabolic disorders associated with menopause differ in surgical and natural menopause women. The metabolic complications should be considered following menopause. [ABSTRACT FROM AUTHOR]