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Significant uncertainty remains regarding the exact timing and nature of subduction events during the closure of the Tethyan seas in what is now NW Iran. This study thus presents new geochemical compositions and U–Pb ages for a suite of volcanic rocks emplaced during Cenozoic volcanism in the west Alborz Magmatic Assemblage, which is commonly regarded as the back-arc of the Neotethyan magmatism in Central Iran. The subalkali basalts and andesites are dated to 57 ? 1.2 Ma, and are likely derived from a supra-subduction mantle wedge. Later, trachytic A-type rocks erupted from ∼42 to 25 Ma during an anorogenic (extensional) stage triggered by slab retreat and associated asthenospheric mantle influx. A-type melts were at least partly concur
Several gabbro, gabbroic diorite, and diorite intrusions were emplaced in the Neotethyan Urumieh-Dokhtar magmatic arc in the Kahak area of the Zagros Orogen. The plutonic rocks intruded Cenozoic volcanic and pyroclastic succession. U-Pb dating via LA-ICP-MS of zircon yields early to middle Eocene ages of~ 53 to 38 Ma for the diorite and gabbroic diorite in Veshnaveh and Naragh areas and Miocene ages of 23 to 20 Ma for gabbroic rocks in the Kerogan and Fordou areas. The Eocene magmatic phase occurred quite possibly as three continuous pulses. The Eocene and Miocene intrusions have negative Nb-Ta anomalies like those of subduction-related magmas. The Pb isotopic compositions show the involvement of subducted sediment in the source of the stud
Production of hydrogen sulphide in various oil and gas reservoirs has been reported around the world. Hydrogen sulphide is one of the major challenges in the operation and refining process of oil and gas. Therefore, determining the origin and mechanism of hydrogen sulphide production in gas and oil reservoirs is of great importance. The aim of this study was to determine source of H2S generation and production in a gas filed that initially produced very low concentration and eventually some wells faced with increasing level after about ten years which highly affected production and downstream facilities. In this research, detailed geological and comprehensive laboratory studies (petrography and isotopic analysis of gas, rock and water) were
Background and Aim: Organizations should know that if the mouths of organizations are silenced, there will be a decrease in productivity and performance in human capital. The present study was conducted to identify the relationship between managers' organizational silence and human resource productivity in one of the militarymedical universities in Tehran, Iran.Methods: In the present cross-sectional study, all managers of the military medical university were studied by the census. The standard questionnaires of human resource productivity of Hersey and Goldsmith Model and the questionnaire of organizational silence" Salavati et al" were used. Data analysis was performed using SPSS software version 21.Results: Pearson correlation coefficien
Organ-on-a-chip technology has gained great interest in recent years given its ability to control the spatio-temporal microenvironments of cells and tissues precisely. While physical parameters of the respective niche such as microchannel network sizes, geometric features, flow rates, and shear forces, as well as oxygen tension and concentration gradients, have been optimized for stem cell cultures, little has been done to improve cell-matrix interactions in microphysiological systems. Specifically, detailed research on the effect of matrix elasticity and extracellular matrix (ECM) nanotopography on stem cell differentiation are still in its infancy, an aspect that is known to alter a stem cell’s fate. Although a wide range of hydrogels s
Background: The relation between disfluency and aspects of language, including phonology, has been investigated for many years. Whereas past literature reported that the incidence of phonological difficulties is higher for children who stutter when compared to normally fluent children, the suggestion of association between the two disorders also drew several critical evaluations. This study investigated the phonological awareness abilities of four- and five- year old non-fluent preschool children. Methods: 25 non-fluent preschool children (21 boy and 4 girl) were paired according to age, sex and socioeconomic status to their typically fluent peers. Participants completed multiple measures of phonological awareness abilities, as well as meas
Background Resistant Helicobacter pylori to commonly used antimicrobial agents are associated with severe upper gastrointestinal disorders. To provide an epidemiological picture of H?pylori and characterize the resistance pattern and genetic variation of clinical isolates, stomach biopsies from patients with functional dyspepsia were evaluated in northeast of Iran. Materials and methods In this study, 80 patients were recruited. Finally, fifty H?pylori strains were isolated from antrum and corpus biopsies by culturing on Columbia agar. All strains were identified by standard laboratory procedures. Susceptibility testing of antibiotics was performed using minimum inhibitory concentration test. Allele‐specific primer (ASP)‐PCR of 23S
The low membrane permeability of lipophilic drugs was resolved using liposomes as a solubilizing agent and the precise size control of them is a significant parameter in drug carrier technology. Here, we have established a microfluidic octanol-assisted liposome assembly method to produce a surfactant-assisted liposome which has merged by the cytoskeleton drug (Taxotere) encapsulation in a single process step, then a complete microfluidic cellular analysis was performed in trapping cell device with an optofluidic assay for quantifying drug permeability. The optimization of process variables resulted in the formation of liposomes with particle size 6.75?0.5 ?m and monodispersity 6.2%, representing encapsulation efficiency and loading capacity
We report a petrographic and whole-rock geochemical characterization of the Cenozoic volcanic rocks cropping out in the Tafresh area of the central Urumieh-Dokhtar Magmatic Arc of Iran. The investigated rocks range mainly from basaltic andesite to dacite, and are considered to be genetically linked by (mostly) closed-system evolutionary processes involving fractionation of ferromagnesian minerals and plagioclase first, then of plagioclase and lesser amphibole (plus minor clinopyroxene) and finally of plagioclase with lesser alkali feldspar and minor amphibole. These represent a typical calcalkaline series emplaced in a subduction-related setting, producing the observed LILE-enriched and HFSE-depleted geochemical signature. The basaltic ande
Tertiary volcanic rocks in northwestern Firoozeh, Iran (the Meshkan triangular structural unit), constitute vast outcrops (up to 250?km2) of high-Mg basaltic andesites to dacites that are associated with high-Nb hawaiites and mugearites. Whole-rock 40Ar/39Ar ages show a restricted range of 24.1???0.4–22.9???0.5?Ma for the volcanic rocks. The initial ratios of 87Sr/86Sr and 143Nd/144Nd vary from 0.703800 to 0.704256 and 0.512681 to 0.512877, respectively, in the high-Mg basaltic andesites–dacites. High-Th contents (up to 11 ppm) and Sr/Y values (27–100) and the isotopic composition of the subalkaline high-Mg basaltic andesites–dacites indicate derivation from a mantle modified by slab and sediment partial melts. Evidence such as reve
The β42 amyloid peptides (Aβ) are identified as a candidate target for Alzheimer’s drugs. Phenolic compounds can bind to the Aβ and inhibit amyloid formation. However, the inhibitory mechanism of phenolic compounds remains unclear. In this study, the molecular dynamic simulation and docking program were used to characterize the molecular details of inhibitory mechanism of the phenolic compounds. Our Results show that the phenolic compounds can bind to hydrophobic region in Aβ42 monomer and alter hydrophobic interactions network at Aβ42 which play a key role in β-sheet formation. The cluster analysis and interactions network analysis were used to probe conformational changes in Aβ42. In most populated clusters of Aβ42-phenolic comp
Calprotectin is a heterodimeric protein complex which consists of two subunits including S100A8 and S100A9. This protein has a major role in different inflammatory disease and various types of cancers. In current study we aimed to evaluate the structural and thermodynamic changes of the subunits and the complex in presence of sodium and calcium ions using molecular dynamics (MD) simulation. Therefore, the residue interaction network (RIN) was visualized in Cytoscape program. In next step, to measure the binding free energy, the potential of mean force (PMF) method was performed. Finally, the molecular mechanics Poisson-Boltzmann surface area (MMPBSA) method was applied as an effective tool to calculate the molecular model affinities. The MD
Lack of perfect insulin signaling can lead to the insulin resistance, which is the hallmark of diabetes mellitus. Activation of insulin and its binding to the receptor for signaling process initiates via B-chain C-terminal hinge conformational change through an open structure to “wide-open” conformation. Observational studies and basic scientific evidence suggest that vitamin D and E directly and/or indirectly prevent diabetes through improving glucose secretion and tolerance, activating calcium dependent endopeptidases and thus improving insulin exocytosis, antioxidant effect and reducing insulin resistance. On the contrary, clinical trials have yielded inconsistent results about the efficacy of vitamin D supplementations for the contr
Laser ablation ICP‐MS U–Pb dating on inherited zircons from Neogene volcanic rocks of the Tafresh area in the central part of Urumieh‐Dokhtar Magmatic Arc (UDMA) yielded Paleoproterozoic, Late Neoproterozoic–Early Cambrian, Carboniferous, and Cretaceous ages. These ages improve our understanding of the geodynamical evolution of central UDMA. The 2,379?Ma age (i.e., Paleoproterozoic) is the oldest age reported in the central UDMA and is similar to the age of detrital zircons from Central Iran. The Paleoproterozoic zircons may come from the African Craton and fed from Central Iran sedimentary sequences. The Late Neoproterozoic–Early Cambrian ages (605???11?Ma to 533???9.2?Ma) indicate a basement for the UDMA, which is similar to tha