فهرست مطالب

Sciences, Islamic Republic of Iran - Volume:32 Issue: 3, Summer 2021

Journal of Sciences, Islamic Republic of Iran
Volume:32 Issue: 3, Summer 2021

  • تاریخ انتشار: 1400/06/31
  • تعداد عناوین: 6
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  • Zahra Hajihassan *, Navid Nazari, Fatemeh Armaghan Pages 205-211

    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.

    Keywords: Activin A, trigger factor, agitation rate
  • Aliakbar Dehno Khalaji *, Seyyedeh Masomeh Mousavi, Zahra Palang Sangdevini, Marketa Jarosova, Pavel Machek, Michal Dusek Pages 213-219

    In this paper, we report a simple and convenient method for the synthesis of α‑Fe2O3 nanoparticles via hydrothermal process followed by thermal decomposition using the new iron precursor, which was obtained by mixing of benzoic acid (BA) and Fe(NO3)3∙3H2O in water as solvent. Two products with almost similar morphologies and sizes were obtained by changing the calcination temperature (500 and 600ºC) for 2 h in the air atmosphere. They were named as Fe‑500 and Fe‑600, respectively, and characterized by Fourier transform infrared (FT‑IR) and ultraviolet‑visible (UV‑Vis) spectroscopy, X-ray powder diffraction (XRD), Energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). FT‑IR, UV‑Vis, XRD and EDS results confirm the formation of α‑Fe2O3 phase. Also, TEM images confirm that the size of the products is less than 100 nm.

    Keywords: α-Fe2O3 nanoparticles, hydrothermal, Morphologies, X-ray diffraction
  • Elham Nazari Zadeh, Mohammad Poosti *, Asma Nazarinia Pages 221-233
    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.
    Keywords: Arangue complex, Pillow lava, MORB, Hormozgan Province, Makran
  • Kamran Pazand, Kaveh Pazand * Pages 235-242
    This paper presents new information about the hydrogeochemistry of water resources in the Gharye-Alarab basin (south-eastern Iran) and determines the predominant hydrogeochemical processes in the basin. To study this basin, 31 water samples were sampled, including 11 samples from rivers and 20 samples from groundwater. These samples were analyzed for temperature, total dissolved solids, Eh, pH, electrical conductivity, major ions and 18 trace elements volumes. The most waters were grouped into Ca–Mg–HCO3 type. Reaction of silicate minerals is the main factor of geochemical processes in the study area. Trace elements concentrations are low and Surface waters have lower trace element abundances compared to groundwater. Arsenic compared with other trace elements; shows a rather wide concentration range in the sampled waters, ranging between 0.6 to 502 µg/l and is not dependency with Eh and pH in surface water but are dependent on pH and Eh in groundwater.
    Keywords: Hydro geochemical, interaction, Water type, arsenic
  • Masoome Zahiri * Pages 243-244
    A ring R is said to be right McCoy‎, ‎if for every f(x),g(x) in the polynomial ring R[x], with f(x)g(x)=0 there exists a nonzero element cϵR with f(x)c=0‎. In this note‎, ‎we show that von Neumann regular McCoy rings are abelian‎. ‎This gives a ‎positive answer to the question rised in ‎ ‎Comm‎. ‎Algebra  42 (2014) 1565- 1570.”
    Keywords: McCoy rings‎, ‎Von Neumann regular rings, ‎Abelian rings
  • Araf Khanjari Idenak, Mohammad Reza Zadkarami *, Seyed Mohammad Reza Alavi Pages 245-258
    We introduce a method to generate a new class of lifetime models based on the bounded distributions such that the defined models are exclusively a special case of the new class. A new subfamily, Generalized Alpha Power (GAP) is discussed and some stochastic orders in this subfamily are investigated to identify the proposed method effect. The performance of the maximum likelihood estimators based on the simulation is studied and in the end, the importance and flexibility of the new family for the models are illustrated by a real data set. Our results indicate that using the proposed method substantially improves the fitness of any G-family model and can be extended to any real data set. Finally, the GAPTW regression model is applied to the kidney infection data.
    Keywords: Bounded Distribution, G-family Model, Lifetime, Regression, Stochastic Orders