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Improved Production of Recombinant Human Activin A in Escherichia coli

Activin A is a member of transforming growth factor β (TGF-β) superfamily. It plays numerous roles in the body such as cell growth regulation and differentiation, wound repairing and modulation of inflammatory responses. More importantly, it can be used as a therapeutic agent; so recombinant production of it, especially in the periplasm of E. coli as an economical bacterium is of great value. The aim of this study is large- scale production of activin A with a correct structure. For this purpose, three strategies were used. First, an efficient and appropriate signal peptide, modified Iranian Bacillus Licheniformis α-amylase signal peptide, was selected to secrete activin A to the E. coli periplasm as a suitable environment for correct protein folding. Second, cytoplasmic chaperones, Dnak, DnaJ, GroEL/ GroES, TF (trigger factor) were expressed simultaneously with activin A. Finally, the agitation rate was optimized to achieve the highest production of Activin A at the bioreactor scale. Our results indicated that by the co-expression of TF with activin A and using agitation rate of 1000 rpm maximum expression of activin A in E. coli was obtained. More importantly, based on the CD spectroscopy results and bioassay test the produced activin A had the correct secondary structure as the commercial type and was fully active.

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Mineral Chemistry and Whole-rock Geochemistry of Pillow lava from the Arangue Complex, Southeastern Hormozgan, Iran

The Upper Cretaceous Arangue complex is located in the Makran zone at the SE of Iran. The complex consists of ultra-mafic rocks, microgabbro dykes, pillow lavas and lime stones that pillow lavas are mainly exposed to the northwest and southeast part of study area. There are oval and tubular basalt lavas with cracked bread crust surface. They predominantly have plagioclase, clinopyroxene with minor olivine and opaque minerals in a fine-grained groundmass along with glass. Mineral chemistry data show that plagioclases and clinopyroxene composition varies from An68.27-81.73 Ab18.27-31.57 Or0-0.41 and Wo38.1- 47.8Fs8.2-19.3 En38.6-48.7 respectively. In the geochemical diagrams, the Arangue complex pillow lavas fall in the basalt and sub-alkaline fields. Geochemical data indicate that the Arangue complex pillow lavas are tholeiitic. The absence of a distinct Eu anomaly (Eu/Eu*= 0.8-1.2), indicates that plagioclase fractionation is not notable, or that the magma is a little oxidized. The Arangue complex pillow lavas show properties similar to transitional basalts between enriched MORB and OIB and some BABB. However, their enrichment in incompatible elements and low Nb and La / Nb ratios (0.8-2.1) display that these have affinity of the BABB. These were produced by approximately 15-25% partial melting of plagioclase lherzolite where fractionation was controlled by removal of clinopyroxene, spinel, and olivine. Petrogenetic study indicates that the source of mantle lherzolite is subjected to enrichment variables in subduction components consisting of fluids for the Arangue Complex pillow lavas.

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Green Synthesis, Characterization, and Biological Evaluation of Hydroxyl-Capped Tellurium Nanoparticles

In this study, we used a simple green method for preparing tellurium nanoparticles and mainly evaluated their toxicological effects. The nanoparticles were synthesized using lactose and characterized with different instrumentation methods. The in vitro and in vivo cytotoxicity of tellurium nanoparticles and its effect on lipid profile were also evaluated. Hydroxyl-capped tellurium nanoparticles were successfully fabricated by lactose. The results showed spherical tellurium nanoparticles with a mean size of 89 nm. The toxicological study showed that the tellurium nanoparticles did not exhibit any toxicity on the primary cells. The LD50 values for the nanoparticles were 327 and 295 mg/kg for oral and intraperitoneal administrations, respectively. Also, the results showed a significant reduction in liver enzymes at the 16, 24, and 40 mg/kg doses. Hematological parameters indicated no significant suppressive changes between the animals that were administered tellurium nanoparticles and the control group. In addition, the effects of tellurium nanoparticles on hypercholesterolemic risk factors in mice fed with cholesterol demonstrated the depletion of triglyceride, cholesterol, and low-density lipoprotein. This study showed that the toxicity of tellurium nanoparticles was lower than tellurium ions. Furthermore, tellurium nanoparticles decreased the cholesterol and triglyceride levels in the animal model.

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Magma Evolution And Mantle Metasomatism: Constraints On Olivine Composition In Potassic-Ultrapotassic Mafic Rocks From Lar Igneous Suite, SE Of Iran

The Lar igneous suite (LIS), in southeastern Iran, is part of post collisional alkaline magmatism in Sistan suture zone. Shonkinite and kersantite are the only two high-Mg, K-rich olivine bearing rocks in the LIS. We study major and some compatible trace elements in the Lar shonkinite and kersantite (LSK) olivines to define mantle mineralogy and metasomatic processes. Olivines in shonkinite have higher Fo (83-90), compared with those in kersantite (Fo76-80). Ca and Ni contents in the olivines are relatively low, whereas their Mn and Ti contents are high and variable, respectively. Low Ni contents exhibit olivine crystallization at igneous conditions from a magma originated by partial melting of an olivine-rich mantle source. Geochemical date reveal that magma evolution is responsible for high-Mn and low Fo contents in kersantitic olivines. In contrast, high Mn, Mn/Fe and Fo contents in shonkinitic olivines indicate an existence of Mn-rich and Ca-Si-poor metasomatic agents in the source. So, considering the Middle Oligocene-Miocene post-collision nature of the Lar igneous suite, melts or fluids derived from upwelling asthenosphere in the form of magnesitic-carbonatite melts, had great potential in metasomatism of subcontinental lithospheric mantle. This CO2 and K-rich liquid then reacts with peridotite to produce new mineral assemblages including low-Ca clinopyroxene, olivine and phlogopite. Partial melting of such metasomatized source region was responsible for producing the undersaturated, K-rich shonkinite and kersantite in the LIS. Keywords: Lar, kersantite, shonkinite, olivine, mantle metasomatism.

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The Impacts of Simulated Microgravity on The Cell Viability and Claudin-1 and Claudin-3 Expression of MCF-7 Breast Cancer Cells

It has been believed that microgravity directly can alter the structure, morphology, and function of biosystems and numerous research have been performed to recognize these alterations. Claudin proteins are the tight junctions’ main components. Additionally, they are crucial for the protection of the differentiated state of epithelial cells as well as for cell-cell interaction. This study aimed to explore the probable correlation between the claudin-1 and claudin-3 expression and microgravity condition. Additionally, examined the impacts of microgravity condition on cell morphology and viability. The gene expression in MCF-7 cells were assessed by real-time quantitative RT PCR. Afterward, the morphology and cellular viability of the cells were evaluated by an inverted microscope, MTT assay, and flow cytometry analysis. After 72 h of simulated microgravity, the claudin-1 and claudin-3 expression increased significantly (P<0.05). Also, MCF-7 cells after 72 h exposure to microgravity simulation comprised rounded cells, which were grouped and linked to each other making multicellular spheroids. However, microgravity simulation after 24 or 72 h did not have a remarkable effect on the viability of cells. The consequence of this research lied in the fact that simulated microgravity could not be a direct cure for breast cancer treatment. However, microgravity research can offer a unique in vitro tool to explore biomechanical effects in the biology of cancer. The findings obtained from this investigation can open fascinating research lines in astrobiology, biophysics, and cancer biology and can be utilized to improve survivability and life quality for malignancy patients.

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