By applying the unified first law of thermodynamics on the apparent horizon of FRW universe, we get the entropy relation for the apparent horizon in quasi-topological gravity theory. Throughout the paper, the results of considering the Hayward-Kodama and Cai-Kim temperatures are also addressed. Our study shows that whenever, there is no energy exchange between the various parts of cosmos, we can get an expression for the apparent horizon entropy in quasi-topological gravity, which is in agreement with other attempts followed different approaches. The effects of a mutual interaction between the various parts of cosmos on the apparent horizon entropy as well as the validity of second law of thermodynamics in quasi-topological gravity are also perused.

In this paper we show that the gravitational field equations of (n + 1)-dimensional topological black holes with constant horizon curvature, in cubic and quartic quasi-topological gravity, can be recast in the form of the first law of thermodynamics, dE = T dS − P dV , at the black hole horizon. This procedure leads to extract an expression for the horizon entropy as well as the energy (mass) in terms of the horizon radius, which coincide exactly with those obtained in quasi-topological gravity by solving the field equations and using the Wald's method. We also argue that this approach is powerful and can be extended to all higher order quasi-topological gravity for extracting the corresponding entropy and energy in terms of horizon radius.

In this paper, we study thermodynamical properties of the apparent horizon in a universe governed by quasi-topological gravity. Our aim is twofold. First, by using the variational method we derive the general form of Friedmann equation in quasi-topological gravity. Then, by applying the first law of thermodynamics on the apparent horizon, after using the entropy expression associated with the black hole horizon in quasi-topological gravity, and replacing the horizon radius, r+, with the apparent horizon radius,rA, we derive the corresponding Friedmann equation in quasi-topological gravity. We find that these two different approaches yield the same result which show the profound connection between the first law of thermodynamics and the gravitational field equations of quasitopological gravity. We also study the validity of the generalized second law of thermodynamics in quasi-topological cosmology. We find that, with the assumption of the local equilibrium hypothesis, the generalized second law of thermodynamics is fulfilled for the universe enveloped by the apparent horizon for the late time cosmology. * mhd@shirazu.ac.ir † asheykhi@shirazu.ac.ir

Background: One of the acute hematologic malignancies is acute promyelocytic leukemia (APL) that resulted in translocation of chromosomes 15 and 17, t (15; 17), and cessation in the maturation of myeloid cell line, and ultimate aggregation of neoplastic promyelocytes. Regarding that appetence of using herbal and marine medicine studies is increasing, and on the other hand, the features of Cassiopea andromeda Venom remained unclear; this study was conducted to determine its effects on NB4 cells as a model for APL. Materials and Methods: In this experimental study, the cells were treated with C. andromeda Venom concentrations at different periods and times. Growth inhibition and toxic effects of C. andromeda Venom were evaluated through methyl thiazole tetrazolium salt reduction (MTT test). The flow cytometry analysis was carried out using 7AAD and Annexin V stains for evaluating this venom’s effect on apoptotic pathways. Besides, Real-Time polymerase chain reaction was performed to evaluate the relative gene expression. Results: C. andromeda Venom inhibited the growth of NB4 cells as correlated with concentration and time. Cell growth was inhibited by 49.1%, after 24 hours of treating NB4 cells with 1000µg/mL C. andromeda Venom. This venom increased the apoptotic process, which was then verified by 7AAD/AnnexinV staining. The fold change of p15INK4b, p21 WAF1/CIP1, P53, DNMT1, and Bcl-2 genes in the NB4 cell line were 144, 2.78, 1.75, 15.24, and 0.33, respectively, which meant that the expression level of p15INK4b, p21 WAF1/CIP1, P53, and DNMT1 were increased by 14400%, 278%, 175%, and 1524%, respectively and the expression of Bcl-2 was decreased by 67%. Conclusion: Considering the inhibitory property of C. andromeda Venom, the authors recommended it as a part of combinational medication for treating APL in animal trials and for other leukemias’ in vitro studies.

Background and Aim: Proliferate potential differentiate into different cell lineages and high self-renewal of Mesenchymal Stem Cells (MSCs); thus, they are ideal tools for regenerative medicine. However, a leading problem is an oxidative stress in the target tissue and the apoptosis of transplanted stem cells before tissue repair. The pretreatment of stem cells with antioxidants may make them resistant to oxidative stress. Ginger is the main medicinal plant with antioxidant properties. This study explored the antioxidant effects of ginger extract on bioavailability and oxidative stress-induced apoptosis in human adipose tissue-derived mesenchymal stem cells and rat bone marrow examined. Methods & Materials: In this study, human adipose tissue-derived mesenchymal stem cells and rat bone marrow were cultured in a DMEM medium with 20% FBS. The explored cells were incubated for 4 and 6 hours for pretreatment with different concentrations of ginger extract (50, 100, 200, & 400 mg/mL); then, they were treated with 200 μM H2O2 for 2 hours. Bioavailability was analyzed by ELISA reader using an MTS kit and apoptosis was analyzed by flow cytometry using an Annexin V-FITC/PI kit into the manufacturer’s protocol at both times. The obtained data were analyzed by Analysis of Variance (ANOVA) using SPSS. Ethical Considerations: This study was approved by the Ethics Research Committee of Shahrekord Branch, Islamic Azad University (Code: IR.IAU.SHK.REC.1397.028). Results: The MTS results indicated a dose- and time-dependent manner increase in the bioavailability of human adipose tissue-derived mesenchymal treated stem cells. Ginger extract treatment also dose- and time-dependently decreased the rate of apoptosis in rat bone marrow mesenchymal stem cells. Conclusion: Ginger extract, by reducing the oxidative stress in mesenchymal stem cells, elevates their lifespan in the target tissue, and increases the efficiency of these cells in tissue regeneration.