Effect of zinc supplementation on serum mlondealdehyde and lipid profiles on beta thalassemia major patients

Objectives: Thalassemic patients are seriously at risk of serum dislipidemia, zinc deficiency and tissue damage due to oxidative stress induced by iron storage. In biologic systems, zinc may interact with iron and inhibit oxidative and reductive reactions resulted by iron and other chimiooxidative agents. The aim of this study was to evaluate the effect of zinc supplementation on serum Malondealdehyde (MDA) and lipid profiles in beta thalassemia major patients. Methods: In this clinical trial, 60 beta thalassemia major patients (male & female) older than 18 years old were assigned randomly in two groups as intervention and control groups(30 per group). The intervention group ingested zinc supplement as 220 mg zinc sulfate capsule contented 50 mg elemental zinc daily for 3 months. The control group did not receive any supplement in that time. Information about general characteristics, weight, height and dietary intake were gathered before and after the end of study. Blood samples were obtained from each subject prior and after the study and serum zinc, MDA, triglyceride, LDL-C and HDL-C levels were measured. Data analyzed with paired t-test, independent t-test and ANOVA. Results: Zinc supplementation caused significant increasing in daily caloric intake, body mass index, serum zinc and HDL-C levels and significant reduction in LDL-C levels in intervention group. No significant variations were observed for other variables in both of groups. Conclusion: Zinc supplementation had beneficial effects on serum lipid profiles in studied beta thalassemic patients and might have suitable role in delaying cardiovascular disease risks in these patients

Effects of vitamin e and zinc supplementation on antioxidants in beta thalassemia major patients

Objective: In beta thalassemic patients, tissue damage occurs due to oxidative stress and it happens because of the accumulation of iron in the body. This study was conducted to determine the effect of zinc and vitamin E supplementation on antioxidant status in beta-thalassemic major patients. Methods: This double blind randomized clinical trial was carried out on 120 beta thalassemic patients older than 18 years. Patients were randomly categorized in four groups. Zinc (50mg/day) and vitamin E (400mg/day) supplements were administered for former and latter group, respectively. In the third group both supplements were administered in similar doses. The fourth (control) group received no supplement. The effect of supplementations on serum zinc and vitamin E, superoxide dismutase (SOD), glutathione peroxidase (GPX), total antioxidant capacity (TAC) and body mass index (BMI) were measured at the beginning and the end of the study. Findings: Serum zinc levels in group 1 and 3 were significantly increased (P<0.007 and P<0.005, respectively). Serum vitamin E levels in group 2 and 3 were also increased significantly (P<0.001). Mean GPX activity in group1, 2 and 3 decreased significantly (P<0.015, P<0.032 and P<0.029, respectively). Mean SOD activity and TAC did not show significant change after supplementation. BMI had significant increase in all treated groups (P<0.001). Conclusion: Our results suggest that beta thalassemic patients have enhanced oxidative stress and administration of selective antioxidants may preclude oxidative damage. © 2011 by Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, All rights reserved

Convection of heat and thermodynamic irreversibilities in two-phase, turbulent nanofluid flows in solar heaters by corrugated absorber plates

The effects of simultaneous implementation of corrugated walls and nanoparticles upon the performance of solar heaters are investigated. Triangular and sinusoidal wall profiles along with varying concentration of nanoparticles are analyzed. The multi-phase mixture and the SST κ-ω models are used to simulate turbulent nanofluid flows inside the corrugated channels. The staggered computational grid is employed for storing the velocity and pressure terms at cell faces and cell center, respectively. The governing equations are first discretized by employing a second-order upwind differencing technique and are then solved by means of pressure-based finite volume approach. The convergence criterion is also presented for the validation of obtained results. The effects of wall profiles and nanoparticle concentration on the pertinent parameters including Nusselt number, pressure drop, performance evaluation criterion (PEC), and thermal and frictional irreversibilities are studied. This reveals that, in general, the triangular duct features superior heat transfer and inferior hydraulic characteristics in comparison with the sinusoidal duct. It is demonstrated that as long as the base fluid (water) is used the highest value of PEC corresponds to the straight duct. Yet, by introducing nanofluids the PEC values of the corrugated ducts exceed those of the straight duct. The analysis further shows that on the basis of the performance evaluation criterion, the sinusoidal duct appears to be a better choice in comparison with the triangular duct. However, the situation is reversed when thermodynamic irreversibilities are considered. It is argued that vortex formation in the two investigated wavy walls and shear layer developed in the triangular case are the essential physical reasons for the observed thermal, hydraulic and entropic behaviors

Forced convection of nanofluids in an extended surfaces channel using lattice Boltzmann method

Research on nanofluids for heat transfer augmentation has received a great attention from many researchers. Recently, many numerical works have been conducted to examine their applicability in predicting heat transfer with nanofluids. In the present study, a two-dimensional (2D) lattice Boltzmann method (LBM) was applied for numerical simulation of forced convection in a channel with extended surface using three different nanofluids. The predicted were carried out for the laminar nanofluid flow at low Reynolds number (10 ? Re ? 70), nanofluid concentration (0.00 ? f ? 0.050), different geometric parameter (0.2 ? A = l/H ? 0.8) and relative height of the extended surfaces (0.05 ? B = h/H ? 0.35). The results indicated that the average Nusselt number increases when the nanofluid concentration increased from 0% to 5%. Moreover, the effect of the nanofluid concentration on the increasing of heat transfer is more noticeable at higher values of the Reynolds number. It is concluded that the use of extended surfaces can enhance the rate of heat transfer for certain arrangements. We also found that the nanofluid with CuO nanoparticles performed better enhancement on heat transfer compared Al 2 O 3 /water and TiO 2 /water nanofluids

Effect of Exposure Conditions on the Long-Term Dielectric Properties of Mortar Samples Containing ASR Gel

Alkali-silica reaction (ASR) is a chemical reaction between alkalis present in portland cement and amorphous or otherwise disordered siliceous minerals in particular aggregates. Through this reaction, reactive silica binds with hydroxyl and alkali ions and forms a gel, known as ASR gel. Recently, microwave materials characterization techniques have shown great potential for detecting ASR in mortar. However, the comprehensive understanding of variables that affect the extent of ASR in mortar and their interaction with microwave signals, in particular the effect of environmental exposure conditions requires more investigations. Therefore, parameters related to these conditions must be considered when using microwave techniques for ASR detection and evaluation. In this paper, the effect of exposure conditions on ASR gel formation and microwave dielectric properties of mortar samples is investigated. To this end, extended measurements of the complex dielectric constants of three different sets of mortar samples are presented at S-band (2.6-3.95 GHz). The samples were cast with potentially reactive ASR-aggregates and subjected to different environmental conditions. The results show slightly different permittivities for the differently stored samples, potentially indicating different amount of ASR gel. This observation was corroborated through UV fluorescence microscopy, where different amounts of ASR gel were observed in the samples. Moreover, the results indicate that ASR gel evolution may be better tracked through loss factor measurements, while pre-existing-gel may be better detected through permittivity measurements

Residual trees injury assessment after selective cutting in broadleaf forest in Shafaroud

In the Shafaroud forest, logging operation is generally performed by using selective cutting methods. Chainsaw and cable skidder are two main forest machines for harvesting of this forest. However, forest harvesting operations result in serious residual stand damage during felling, winching and skidding operations in this forest. Residual stand damage resulting from selective cutting was assessed on Avardim district in the Shafaroud forest in the north of Iran. Logging operation was performed by chainsaw and cable skidder. To gain benefit of directional felling, Landing and skid trail was planned prior to felling. Study area was cruised using 14 random sampling plots centered on transect lines uniformly distributed throughout the harvested area. Study results indicate majority of the injuries that occurred belong to the skidding and winching stage and the bole portion of tree (> 1m). Beech trees were injured more than trees of other species, and the mean area of injury was 290.3 cm2. Investigation on felling error showed that 40% of felled trees were at an angle of about 45-70 degrees with skidding direction, therefore felling crew could not lead the felled trees toward the skid trails. Increase felling error made the remaining trees more susceptible to injuries. This research indicated that preliminary planning of skid trail prior to felling is not a sufficient measure to minimize residual stand damage but proper training of crew is essential to insure a good performance of the operation. Felling crew should be not only trained and experienced workers but also aware of the value of residual crop trees, and the importance of minimizing stand damage if uneven-aged stand management practices are to be successful

Diagnosing students' difficulties in learning mathematics

This study considers the results of a diagnostic test of student difficulty and contrasts the difference in performance between the lower attaining quartile and the higher quartile. It illustrates a difference in qualitative thinking between those who succeed and those who fail in mathematics, illustrating a theory that those who fail are performing a more difficult type of mathematics (coordinating procedures) than those who succeed (manipulating concepts). Students who have to coordinate or reverse processes in time will encounter far greater difficulty than those who can manipulate symbols in a flexible way. The consequences of such a dichotomy and implications for remediation are then considered

Effect of Nenas honey supplementation on the oxidative status of undergraduate students

Honey is a dietary antioxidant as it contains phenolic compounds, such as flavonoids and phenolic acids. Antioxidants are non-nutritive, biologically active ingredients in food that reduce oxidative stress. The antioxidant content in each type of honey varies depending on its source. This study was aimed to determine the effect of Nenas honey supplementation on the oxidative status of a group of healthy medical students. They were divided into two groups; control (n=10) and supplemented (n=13), where 1 tablespoon of Nenas honey was given each day. Blood sampling was done at baseline, 1st and 2nd month of the study for determination of DNA damage and antioxidant enzyme activities, such as superoxide dismutase (SOD), glutathione peroxidise (GPx), and catalase (CAT). Results showed that Nenas honey increased the level of DNA damage at the 1st month but reduced it significantly at the 2nd month as compared to control. GPx and CAT activities also decreased significantly with honey supplementation throughout the study, though no changes were observed in SOD activity. Fasting glucose levels remained within the normal range with honey supplementation. In conclusion, Nenas honey decreases oxidative stress which leads to a reduction of antioxidant enzyme activities in the body