Islamic Azad University

About: Islamic Azad University is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Population & Adsorption. The organization has 83635 authors who have published 113437 publications receiving 1275049 citations. The organization is also known as: Azad University.

First-order-theory-based thermoelastic stability of functionally graded material circular plates

Abstract: Thermal buckling of circular plates made of functionally graded material is discussed. The nonlinear equilibrium and linear stability equations are derived using variational formulations. The thermal buckling of solid circular plates under uniform temperature rise, gradient through the thickness, and linear temperature variation along the radius are considered, and the buckling temperatures are derived. The buckling temperatures are derived for simply supported and clamped edges. The results are verified with known results in the literature.

Effects of levothyroxine treatment on pregnancy outcomes in pregnant women with autoimmune thyroid disease

Abstract: BACKGROUND Despite some studies indicating that thyroid antibody positivity during pregnancy has been associated with adverse pregnancy outcomes, evidence regarding the effects of levothyroxine (LT4) treatment of euthyroid/subclinical hypothyroid pregnant women with autoimmune thyroid disease on pregnancy outcome is limited. We aimed to assess whether pregnant women with autoimmune thyroid disease, but without overt thyroid dysfunction are affected by higher rates of adverse pregnancy outcomes. In addition, we aimed to explore whether LT4 treatment improves the pregnancy outcome of affected women. METHODS A prospective study was carried out on pregnant women from the first trimester to delivery. The study was conducted among pregnant women receiving prenatal care in centers under coverage of Shahid Beheshti University of Medical Sciences. Of a total of 1746 pregnant women, screened for thyroid dysfunction, 1028 euthyroid TPOAb-negative (TPOAb-) and 131 thyroid peroxidase antibody-positive (TPOAb+) women without overt thyroid dysfunction entered the second phase of the study. TPOAb+ women were randomly divided into two groups: group A (n = 65), treated with LT4 and group B (n = 66), received no treatment. The 1028 TPOAb- women (group C) served as a normal population control group. Primary outcomes were preterm delivery and miscarriage and secondary outcomes included placenta abruption, still birth, neonatal admission and neonatal TSH levels. RESULTS Groups A and C displayed a lower rate of preterm deliveries compared with group B (RR = 0.30, 95% CI: 0.1-0.85, P = 0.0229) and (RR = 0.23, 95% CI: 0.14-0.40, P < 0.001) respectively. There was no statistically significant difference in the rates of preterm labor between groups A and C (RR = 0.79, 95% CI: 0.30-2.09, P = 0.64). The number needed to treat (NNT) for preterm birth was 5.9 (95% CI: 3.33–25.16). CONCLUSIONS Treatment with LT4 decreases the risk of preterm delivery in women who are positive for TPOAb.

A new biogeography-based optimization (BBO) algorithm for the flexible job shop scheduling problem

Abstract: Biogeography-based optimization (BBO) algorithm is a new kind of optimization technique based on biogeography concept. This population-based algorithm uses the idea of the migration strategy of animals or other species for solving optimization problems. In this paper, the BBO algorithm is developed for flexible job shop scheduling problem (FJSP). It means that migration operators of BBO are developed for searching a solution area of FJSP and finding the optimum or near-optimum solution to this problem. In fact, the main aim of this paper was to provide a new way for BBO to solve scheduling problems. To assess the performance of BBO, it is also compared with a genetic algorithm that has the most similarity with the proposed BBO. This similarity causes the impact of different neighborhood structures being minimized and the differences among the algorithms being just due to their search quality. Finally, to evaluate the distinctions of the two algorithms much more elaborately, they are implemented on three different objective functions named makespan, critical machine work load, and total work load of machines. BBO is also compared with some famous algorithms in the literature.

Current developments in green synthesis of metallic nanoparticles using plant extracts: a review.

Abstract: Metal nanoparticles (MNPs) produced by green approaches have received global attention because of their physicochemical characteristics and their applications in the field of biotechnology In recent years, the development of synthesizing NPs by plant extracts has become a major focus of researchers because of these NPs have low hazardous effect in the environment and low toxicity for the human body Synthesized NPs from plants are not only more stable in terms of size and shape, also the yield of this method is higher than the other methods Moreover, some of these MNPs have shown antimicrobial activity which is consistently confirmed in past few years Plant extracts have been used as reducing agent and stabilizer of NPs in which we can reduce the toxicity in the environment as well as the human body only by not using chemical agents Furthermore, the presence of some specific materials in plant extracts could be extremely helpful and effective for the human body; for instance, polyphenol, which may have antioxidant effects has the capability for capturing free radicals before they can react with other biomolecules and cause serious damages In this article, we focused on of the most common plants which are regularly used to synthesize MNPs along with various methods for synthesizing MNPs from plant extracts