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Kheradmand F.,Tehran University of Medical Sciences | Kheradmand F.,Urmia University of Medical Sciences | Nourmohammadi I.,Tehran University of Medical Sciences | Modarressi M.H.,Tehran University of Medical Sciences | And 3 more authors.
Iranian Biomedical Journal | Year: 2010

Background: Zinc (Zn) as an important trace element is essential for testicular development and spermatogenesis. Molecular mechanism of Zn action in the reproductive system may be related to metal binding low-molecular weight proteins, metallothioneins (MT). Our objective was to determine the effect of Zn on two important isoforms of MT, MT1M and MT1G genes expression on testicular sertoli cells. Methods: Cultured sertoli TM4 cells were exposed to different concentrations of Zn at different time points. Cellular uptake of Zn was tested using flame atomic absorption spectrometry. The cellular viability and gene expression were assessed by MTT and real-time PCR methods, respectively. Results: The treated cells resulted in higher Zn concentration and cellular viability. The expression of MT1M and MT1G genes in the treated cells were greater than those of the untreated cells (P<0.05). In the high dosage treated group (100 and 500 μM), Zn concentration and expression of MT1M and MT1G genes increased three h after treatment; MT1G gene expression increased more at sixth h. At 18th h of treatment, the expression of both genes especially MT1G, increased dramatically while Zn concentration decreased. Conclusion: Since the increase of MT1G mRNA was coincident with cellular Zn level, it seems that MT1G has a more prominent role than MT1M in the homeostasis of Zn. In addition, Zn at dosage of 50 μM (pharmacologic concentration) may protect cells by increasing the expression of MT genes at longer periods. Source


Mohaddespour A.,University of Tehran | Abolghasemi H.,University of Tehran | Mostaedi M.T.,Science and Technology Research Institute | Habibzadeh S.,University of Tehran
Journal of Applied Polymer Science | Year: 2010

High density polyethylene- and polypropylene- clay nanocomposites are synthesized by melt blending, in which polyethylene glycol and polypropylene glycol are used as compatibilizers to increase the space of galleries. The morphology properties of nanocomposites are explored by X-ray diffraction and transition electron microscopy. The thermal conductivity coefficient (K) of nanocomposites is also measured along with the thermal stability. A conventional model based on developed Maxwell- Garnett formula is also established to predict the thermal conductivity of polymer/clay nanocomposites with clay loading. Morphology results indicate that two intercalated and exfoliated structures are formed. The established model satisfactorily predicts the K values of nanocomposites for low range of clay content. Thermogravimetric analysis shows remarkable thermal stability of anocomposites with 10 wt % of clay content. The deviation of our model from experimental result for 10 wt % of clay can be attributed to the intercalated structure of layered silicates into the matrices. Although the K values do not considerably increase in 5 wt % with respect to the increase occurs for 10 wt % of clay, but it increases about 28 and 37% at 50°C for high density polyethylene- and polypropylene-clay nanocomposites, respectively. © 2010 Wiley Periodicals, Inc. Source


Jiang B.,Harbin Institute of Technology | Mostofizadeh A.,Harbin Institute of Technology | Mostofizadeh A.,Science and Technology Research Institute | Bai Y.P.,Harbin Institute of Technology | Huang Y.D.,Harbin Institute of Technology
Journal of Physical Chemistry B | Year: 2011

Preparation of the recording coating on the ink jet printing (RC-IJP) is proposed. The microstructure of RC-IJP was analyzed by scanning electron microscopy and atomic force microscope. The surface infiltration process of RC-IJP was studied. Fourier transform near-infrared (FT-NIR) spectra showed the combination and overtone vibrations information of the hydrogen-containing groups in RC-IJP structure. NIR spectra combined with partial least-squares methods were proposed for the noncontact analysis of the surface infiltration time and weight per unit area in RC-IJP. Forty-five samples were selected for the calibration sets of the surface infiltration time and weight per unit area, respectively. Spectral pretreatment method was used to develop robust calibration models. After the spectral pretreatment was optimized, the determination coefficient (R2) of the surface infiltration time and weight per unit area were 0.90 and 0.97, respectively. The analytical results showed that NIR spectra had significant potential for the analysis of the surface infiltration time and weight per unit area of RC-IJP. © 2011 American Chemical Society. Source


Hafizi M.,University of Tehran | Abolghasemi H.,University of Tehran | Moradi M.,University of Tehran | Milani S.A.,Science and Technology Research Institute
Chinese Journal of Chemical Engineering | Year: 2011

In this study, strontium adsorption from sulfuric acid solution by different Dowex 50W-X ion exchange resins was investigated. Among these resins, Dowex 50W-X8 resin showed the maximum sorption of strontium from the aqueous solutions. The effect of pH, contact time, mass of resin, temperature, and concentration of interfering ions on strontium adsorption were evaluated to determine the optimum conditions of strontium sorption process. The kinetic models of sorption were analyzed using pseudo-first and pseudo-second order models. The results indicated that the pseudo-second order kinetic model was more appropriate than the other one. Moreover, the data obtained in this study were fitted into several sorption isotherm models and it was found that the Langmuir sorption isotherm shows the best fitting to the experimental data. © 2011 Chemical Industry and Engineering Society of China (CIESC) and Chemical Industry Press (CIP). Source


Keivani M.,Shahrekord University of Medical Sciences | Khorsandi J.,Science and Technology Research Institute | Mokhtari J.,Islamic Azad University at Khorasgan | Kanani A.,Shiraz University of Medical Sciences | And 2 more authors.
Acta Astronautica | Year: 2016

Paddle-type and double-sided nanostructures are potential for use as accelerometers in flying vehicles and aerospace applications. Herein the pull-in instability of the cantilever paddle-type and double-sided sensors in the Casimir regime are investigated under the acceleration. The D'Alembert principle is employed to transform the accelerating system into an equivalent static system by incorporating the accelerating force. Based on the couple stress theory (CST), the size-dependent constitutive equations of the sensors are derived. The governing nonlinear equations are solved by two approaches, i.e. modified variational iteration method and finite difference method. The influences of the Casimir force, geometrical parameters, acceleration and the size phenomenon on the instability performance have been demonstrated. The obtained results are beneficial to design and fabricate paddle-type and double-sided accelerometers. © 2015 IAA. Published by Elsevier Ltd. All rights reserved. Source

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