Saaidi K.,University of Kurdistan |
Saaidi K.,Kansas State University |
Mohammadi A.,Islamic Azad University at Larestan |
Golanbari T.,University of Kurdistan |
And 2 more authors.
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012
In this work, the quark-hadron phase transition in a chameleon Brans-Dicke model of brane world cosmology within an effective model of QCD is investigated. Whereas, in the chameleon Brans-Dicke model of brane world cosmology, the Friedmann equation and conservation of density energy are modified, resulting in an increased expansion in the early Universe. These have important effects on quark-hadron phase transitions. We investigate the evolution of the physical quantities relevant to quantitative descriptions of the early times, namely, the energy density, ρ, temperature, T, and the scale factor, a, before, during, and after the phase transition. We do this for smooth crossover formalism in which lattice QCD data is used for obtaining the matter equation of state and first order phase transition formalism. Our analyses show that the quark-hadron phase transition has occurred at approximately one nanosecond after the big bang and the general behavior of temperature is similar in both of two approaches. © 2012 American Physical Society.
Absalan F.,Ahvaz Jundishapur University of Medical Sciences |
Absalan F.,Shiraz Human Assisted Reproductive Center |
Ghannadi A.,Shiraz Human Assisted Reproductive Center |
Ghannadi A.,Islamic Azad University at Larestan |
And 4 more authors.
Journal of Assisted Reproduction and Genetics | Year: 2012
Objective: To evaluate and compare standard sperm parameters and sperm chromatin integrity by sperm chromatin dispersion test (SCD) in ejaculates from men whose partners have a history of recurrent pregnancy loss and from control group of fertile men. Methods: Thirty couples with unexplained recurrent abortion (case group) and 30 fertile couples (control group) referring to Shiraz infertility center were included. Sperm parameters were assessed in semen samples from two groups and then staining with SCD procedure. The results were analyzed by performing ANOVA and Tukey ,s tests. Results: In control group, nucleoids with big (65.93 ± 2.35), small (12.4 ± 0.60) and without halo (11.6 ± 0.50) showed significant difference with case group (41.40 ± 1.43), (21.16 ± 1.11) and (23.26 ± 1.10) respectively. In the RPL group spermatozoa with high percentage of abnormal parameters (morphology and motility) was observed (p ≥ 0.05). Conclusion: This study strengthens the current literature associating sperm quality with recurrent pregnancy loss, and emphasizes the important of evaluating male factor by tests such as SCD in addition to conventional sperm parameters. © 2011 Springer Science+Business Media, LLC.
Norouzi M.,Islamic Azad University at Larestan |
Mansouri B.,Islamic Azad University at Kermanshah |
Hamidian A.H.,University of Tehran |
Ebrahimi T.,Shahid Beheshti University |
Kardoni F.,Islamic Azad University at Ahvaz
Bulletin of Environmental Contamination and Toxicology | Year: 2012
This study was conducted to determine the concentration of metals, namely cadmium, lead, cobalt and copper, in the feathers of chukar (Alectoris chukar), see-see partridge (Ammoperdix griseogularis) and rock dove (Columba livia) in order to: examine the species, gender and age related variations in trace metal accumulation, and identify any relationships between species. Bird samples were collected in February 2012 from the Hormod protected area, southern Iran and the concentration of metals were measured using a Shimadzu AA 660 flame atomic absorption spectrophotometer. The concentrations in all three species were copper > lead > cadmium > cobalt. The average cadmium concentrations were 2.0, 1.9, and 1.9 μg/g for A. chukar, A. griseogularis, and C. livia, respectively. The average lead concentrations were 8.0, 5.4, and 7.7 μg/g for A. chukar, A. griseogularis, and C. livia, respectively. The results showed that in all three species, the highest metal concentrations were observed in female/adult birds and the lowest concentrations were found in female/juvenile birds (except lead in A. chukar and copper in C. livia). © Springer Science+Business Media, LLC 2012.
Fanaei H.,Shiraz University of Medical Sciences |
Keshtgar S.,Shiraz University of Medical Sciences |
Bahmanpour S.,Shiraz University of Medical Sciences |
Ghannadi A.,Islamic Azad University at Larestan |
Kazeroni M.,Shiraz Fertility and Infertility Center
Reproductive Sciences | Year: 2011
Calcium (Ca 2+) and reactive oxygen species (ROS) constitute the most influential intracellular signaling molecules participating in the regulation of different sperm functions. Elevating intracellular Ca 2+ and ROS in physiologic range regulate capacitation, motility, acrosome reaction, and sperm-oocyte fusion; whereas cytosolic Ca 2+ overload and ROS overproduction have pathologic effects. Our aim of this study was determination of antioxidant effects of α-tocopherol on sperm motility, viability, and DNA integrity in a condition where cytosolic calcium overload was induced by A23187 (a calcium ionophore). Our results indicated that, α-tocopherol has ability to prevent sperm mortality and save sperm rapid motility after 1 hour incubation. At the same time, A23187 reduced significantly percentage of rapid sperm motility and increased sperm mortality and DNA damage. Results of sperms incubation in the medium contain a combination of A23187 and α-tocopherol showed that α-tocopherol can reduce many of the deleterious effects of A23187. In conclusion, it seems that the harmful effects of A23187 are due to excessive ROS production, and α-tocopherol neutralizes these effects. © Society for Gynecologic Investigation 2011.
Rokhgireh H.,Islamic Azad University at Larestan |
Nayebi A.,Shiraz University
Mechanics Research Communications | Year: 2016
In this study, a yield surface distortion model coupled with nonlinear kinematic hardening model is proposed. The new yield surface distortion model is used to simulate proportional and non-proportional cyclic loading paths. Distortion of the yield surface and its nonlinear effects on the plastic flow have been studied by researchers and various models. However, these models have been rarely applied to different non-proportional cyclic loading paths. The yield surface evolution is obtained by the new model in cyclic loading and its results are compared with the experimental results of Dannemeyer . The new model with few constants predicts well the yield surface evolution under non-proportional loading paths which leads to well comparison of the numerical results with respect to the experimental results. © 2016 Elsevier Ltd. All rights reserved.