Search for: oxygen-consumption
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    Comparison of the effects of growth hormone on acylated ghrelin and following acute intermittent exercise in two levels of obesity

    , Article Tehran University Medical Journal ; Volume 71, Issue 5 , 2013 , Pages 330-339 ; 16831764 (ISSN) Gholipour, M ; Tabrizi, A ; Sharif University of Technology
    Background: The prevalence of obesity has risen enormously over the past few decad-es. Both food intake (Appetite) and energy expenditure can influence body weight. Acylated ghrelin enhances appetite, and its plasma level is suppressed by growth horm-one. The present study, examines the effects of an intermittent exercise with progress-ive intensities on acylated ghrelin, appetite, and growth hormone in inactive male students with two levels of obesity. Methods: Eleven inactive males were allocated into two groups on the basis of their body mass index (BMI). Six subjects in group one, BMI= 31.18±0.92 kg/m2, and five subjects in group two, BMI= 36.94±2.25 kg/m2, ran on the treadmill with... 

    Possible role for growth hormone in suppressing acylated ghrelin and hunger ratings during and after intermittent exercise of different intensities in obese individuals

    , Article Acta Medica Iranica ; Vol. 52, Issue. 1 , 2014 , pp. 29-37 ; ISSN: 1735-9694 Gholipour, M ; Kordi, M. R ; Taghikhani, M ; Ravasi, A. A ; Gaeini, A. A ; Tabrizi, A ; Sharif University of Technology
    Body weight is influenced by both food intake and energy expenditure. Acylated ghrelin enhances appetite, and its circulating level is suppressed by Growth Hormone. Data on the acylated ghrelin responses to exercise of different intensities in obese individuals are currently not available. This study examined the effects of an intermittent exercise protocol on acylated ghrelin levels and hunger ratings in obese people. Nine inactive male ran on the treadmill at 0900 with progressive intensities of 50, 60, 70, and 80% of VO2max for 10, 10, 5, and 2 min respectively. Blood samples were collected before the exercise at 0845 (-15 min as the resting values), after each workload (10, 23, 31, and... 

    The effects of porosity distribution variation on PEM fuel cell performance

    , Article Renewable Energy ; Volume 30, Issue 10 , 2005 , Pages 1557-1572 ; 09601481 (ISSN) Roshandel, R ; Farhanieh, B ; Saievar Iranizad, E ; Sharif University of Technology
    Gas diffusion layers (GDL) are one of the important parts of the PEM fuel cell as they serve to transport the reactant gases to the catalyst layer. Porosity of this layer has a large effect on the PEM fuel cell performance. The spatial variation in porosity arises due to two effects: (1) compression of the electrode on the solid landing areas and (2) water produced at the cathode side of gas diffusion layers. Both of these factors change the porosity of gas diffusion layers and affect the fuel cell performance. To implement this performance analysis, a mathematical model which considers oxygen and hydrogen mass fraction in gas diffusion layer and the electrical current density in the... 

    The acute effects of intermittent treadmill running on hunger and plasma acylated ghrelin concentration in individuals with obesity

    , Article Tehran University Medical Journal ; Volume 69, Issue 2 , 2011 , Pages 125-135 ; 16831764 (ISSN) Gholipour, M ; Kordi, M ; Taghikhani, M ; Ravasi, A ; Gaeini, A ; Tabrizi, A ; Sharif University of Technology
    Background: Body weight is regulated by both food intake and energy expenditure. Ghrelin, a hormone produced by the stomach and pancreas, enhances appetite. This study was undertaken to determine the effects of intermittent treadmill running on acylated ghrelin and appetite in individuals with obesity. Methods: Nine inactive male students, with a mean age of 20.56±0.48 yrs, a body mass index of 32.68±0.84 kg/m2 and a maximum oxygen uptake of 34.21±1.48 ml/kg/min, participated in the study in two trials (control and exercise) in a counterbalanced, randomized design. The protocol included intermittent running with a constant intensity at 65% of VO2 max on a treadmill. Blood samples were... 

    Investigating the effect of design parameters on the response time of a highly sensitive microbial hydrogen sulfide biosensor based on oxygen consumption

    , Article Biosensors and Bioelectronics ; Volume 70 , 2015 , Pages 106-114 ; 09565663 (ISSN) Vosoughi, A ; Yazdian, F ; Amoabediny, G ; Hakim, M ; Sharif University of Technology
    Elsevier Ltd  2015
    A novel hydrogen sulfide microbial biosensor was developed based on investigating the influence of four design parameters: cell concentration, immobilization bed type, hydrogen sulfide concentration, and geometrical shape of the biosensor. Thiobacillus thioparus was used as the recognition element and it was immobilized on sodium alginate as well as agarose bed. The results were optimized by the application of statistical optimization software based on response time of the system. Oxygen reduction was considered as the detection sign. Sodium alginate solution with a concentration of 2.3% (w/v) and optical density of 10 at 605. nm was found as the optimum conditions for immobilization with... 

    Simulation of the effects of oxygen carriers and scaffold geometry on oxygen distribution and cell growth in a channeled scaffold for engineering myocardium

    , Article Mathematical Biosciences ; Volume 294 , 2017 , Pages 160-171 ; 00255564 (ISSN) Zehi Mofrad, A ; Mashayekhan, S ; Bastani, D ; Sharif University of Technology
    This study proposes a mathematical model to evaluate the impact of oxygen carriers and scaffold geometry on oxygen distribution and cell growth in a 3D cardiac construct using computational fluid dynamics (CFD). Flow equations, oxygen balance equation and cell balance equation were solved using special initial and boundary conditions. The modeling results revealed that 55% increase in cardiac cell density occurred by using 6.4% perfluorocarbon oxygen carrier (PFC) compared to pure culture medium without PFC supplementation. Moreover, the effects of the scaffold geometry on cell density were examined by changing the channel numbers and the construct length. A 30% increase in the average cells... 

    Role of endurance training in preventing pathological hypertrophy via large tumor suppressor (LATS) changes

    , Article Iranian Heart Journal ; Volume 20, Issue 3 , 2019 , Pages 52-59 ; 17357306 (ISSN) Tabrizi, A ; Soori, R ; Choobineh, S ; Gholipour, M ; Sharif University of Technology
    Iranian Heart Association  2019
    Background: One of the negative effects of cardiac sympathetic hyperactivity is pathologic hypertrophy. Recent studies have indicated that large tumor suppressor (LATS) is one of the molecules which play a critical role in cardiomyocyte apoptosis. Considering the preventive role of exercise training, we evaluated the effects of endurance training on LATS gene expression and its upstream pathway in the present study. Methods: Eighteen male Wistar rats were randomly divided into 2 groups: Endurance and control. Endurance training was performed for 8 weeks, 1 hour per day, and 6 days per week on the treadmill at a 15° inclination. Pathologic hypertrophy was induced with the injection of 3... 

    Optimized bioleaching of copper by indigenous cyanogenic bacteria isolated from the landfill of e-waste

    , Article Journal of Environmental Management ; Volume 261 , 2020 Arab, B ; Hassanpour, F ; Arshadi, M ; Yaghmaei, S ; Hamedi, J ; Sharif University of Technology
    Academic Press  2020
    In this study, indigenous cyanogenic bacterial strains were isolated on nutrient, minimal salt, and soil extract media at various culture conditions from two distinct landfills of e-waste, Iran. Based on their cyanide formation profiles, five most potent isolates were selected for optimization and to this end, the influence of the most effective factors on cyanide production including pH, glycine concentration and temperature were assessed using one-factor at a time method (OFAT). Initial pH of 7, glycine concentration of 2 g/L and temperature of 30°C were obtained as optimal conditions for most of the isolates. Additionally, two bioleaching processes were applied for each bacteria to detect... 

    A mechanobiological mathematical model of liver metabolism

    , Article Biotechnology and Bioengineering ; Volume 117, Issue 9 , 5 June , 2020 , Pages 2861-2874 Nikmaneshi, M. R ; Firoozabadi, B ; Munn, L. L ; Sharif University of Technology
    John Wiley and Sons Inc  2020
    The liver plays a complex role in metabolism and detoxification, and better tools are needed to understand its function and to develop liver-targeted therapies. In this study, we establish a mechanobiological model of liver transport and hepatocyte biology to elucidate the metabolism of urea and albumin, the production/detoxification of ammonia, and consumption of oxygen and nutrients. Since hepatocellular shear stress (SS) can influence the enzymatic activities of liver, the effect of SS on the urea and albumin synthesis are empirically modeled through the mechanotransduction mechanisms. The results demonstrate that the rheology and dynamics of the sinusoid flow can significantly affect...