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Selective extraction of gold(Ⅲ) from hydrochloric acid-chlorine gas leach solutions of copper anode slime by tri-butyl phosphate(TBP)

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Transactions of Nonferrous Metals Society of China 2016年第12期26卷 3258-3265页

作者： Nima SADEGHI eskandar Keshavarz ALAMDARI Department of Mining and Metallurgical Engineering Amirkabir University of Technology

The oxidative leaching causes to dissolve various impurities such as Fe, Cu, Pd, Se in copper anode slime. Organicextractant tri-butyl phosphate (TBP) was used to purify leach solution. Several parameters, such as TBP, HCl and chloride inorganicsalt concentrations were chosen in order to determine efficient state for impurities separation. Standard solvent extraction tests forextraction and separation of Au, Pd, Pt, Fe, Cu and Se were conducted with equal volume of aqueous and organic phases in batchexperiments. The effect of hydrochloric acid, organic phase and metals initial concentration were examined at ambient temperature. Itwas found that 0.25 mol/L TBP in the presence of 2.5 mol/L hydrochloric acid can cause high extraction of gold. Meanwhile, in theseconditions the extraction of other impurities is negligible. After extraction, pregnant organic phase was scrubbed by distilled waterand some impurities were removed. Finally, gold was stripped by sodium thiosulfate solution. The stripping solution does not haveany impurities. By adding H2SO4 to stripping solution containing Na2S2O2, SO2 gas is released and Au3+ ions could be reduced.

关键词： gold solvent extraction separation copper anode slime TBP

Kinetics of magnetite oxidation under non-isothermal conditions

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International Journal of Minerals,Metallurgy and Materials 2017年第5期24卷 486-492页

作者： Aref Sardari eskandar Keshavarz Alamdari Mohammad Noaparast Sied Ziaedin Shafaei Department of Mining Engineering Science and Research BranchIslamic Azad University Department of Mining and Metallurgical Engineering Amirkabir University of Technology School of Mining Engineering University of Tehran

Oxidation of magnetite concentrates, which occurs during the pellet induration process, must be deeply understood to enable the appropriate design of induration machines. In the present paper, the kinetics of the magnetite oxidation reaction was studied. Primary samples were obtained from the Gol-e-Gohar iron ore deposit. Magnetic separation and flotation decreased the sulfur content in the samples to be approximately 0.1wt%. Thermogravimetric analysis was used to measure mass changes during the oxidation of magnetite and, consequently, the conversion values. The aim of this study was to use isoconversional methods to calculate the kinetic parameters. The Coats-Redfern method was also used to obtain the activation energy. Thermogravimetric analyses were run at three different heating rates. The Coats-Redfern results were too ambiguous for a meaningful interpretation. In the case of the isoconversional method, however, the mean activation energy and pre-exponential factor of the oxidation reaction were obtained as 67.55 kJ and 15.32 × 108 min−1, respectively. Such a large activation energy implies that temperature strongly affects the reaction rate. The oxidation reaction exhibits a true multi-step nature that is predominantly controlled by chemical reaction and diffusion mechanisms.

关键词： magnetite kinetics oxidation thermogravimetric analysis

Modeling the Past and Current Distribution and Habitat Suitability for Ablepharus grayanus and A. pannonicus(Sauria: Scincidae)

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Asian Herpetological Research 2018年第1期9卷 56-64页

作者： Rasoul KARAMIANI Nasrullah RASTEGAR-POUYANI eskandar RASTEGAR-POUYANI Department of Biology Faculty of Science Razi University Department of Biology Faculty of Science Hakim Sabzevari University

Study of the climate variability in the past and present, and correlating those with changes in the distribution range of species has attracted considerable research interest. The genus Ablepharus consists of 10 recognized species, of which A. bivittatus, A. grayanus and A. pannonicus are documented from Iran. In the present study, we modeled with MaxEnt the potential distribution areas and determined the suitable habitats in past （mid-Holocene [MH], and the Last Interglacial [LIG]） and their current distribution for two species of snake-eyed skinks （A. grayanus and A. pannonicus） separately. Models of the species indicated good fit by the average high area under the curve （AUC） values （A. grayanus = 0.929 4- 0.087 and A. pannonicus = 0.979 4- 0.007）. Precipitation of the driest quarter of the year, mean temperature of the coldest quarter of the year, and precipitation of the driest month variables made important contributions to A. grayanus. Two important climate variables contributed importantly to A. pannonicus; temperature seasonality, and mean temperature of the wettest quarter of the year, and one topographic variable, slope. We conclude that these variables form a natural barrier for species dispersal. The MH and the LGM models indicated a larger suitable area than the current distribution.

关键词： climate condition suitable habitat potential distribution mid-Holocene Last Interglacial

In vitro-derived insulin-producing cells modulate Th1 immune responses and induce IL-10 in streptozotocin-induced mouse model of pancreatic insulitis

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Hepatobiliary & Pancreatic Diseases International 2021年第4期20卷 376-382页

作者： Gholamreza Daryabor Esmaeil Hashemi Shiri Zahra Amirghofran eskandar Kamali-Sarvestani Autoimmune Diseases Research Center Medical SchoolShiraz University of Medical SciencesShiraz 71345-1798Iran Department of Immunology Medical SchoolShiraz University of Medical SciencesShiraz 71345-1798Iran

Background: Insulitis is defined by the presence of immune cells infiltrating in the pancreatic islets that might progress into the complete β-cell loss. The immunomodulatory properties of bone marrow-derived mesenchymal stem cells(BM-MSCs) have attracted much attention. This study aimed to evaluate the possible immunomodulatory effects of rat BM-MSCs and MSCs-derived insulin-producing cells(IPCs) in a mouse model of pancreatic insulitis. Methods: Insulitis was induced in BALB/c mice using five consecuti ve doses of streptozotocin. MSCs or IPCs were directly injected into the pancreas of mice and their effects on the expression of Th subsetsrelated genes were evaluated. Results: Both BM-MSCs and IPCs significantly reduced the expression of pancreatic Th1-related IFN-γ( P < 0.001 and P < 0.05, respectively) and T-bet genes(both P < 0.001). Moreover, the expression of IL-10 gene was significantly increased in IPC-treated compared to BM-MSC-or PBS-treated mice( P < 0.001 both comparisons). Conclusions: BM-MSCs and IPCs could successfully suppress pathologic Th1 immune responses in the mouse model of insulitis. However, the marked increase in IL-10 gene expression by IPCs compared to BM-MSCs suggests that their simultaneous use at the initial phase of autoimmune diabetes might be a better option to reduce inflammation but these results need to be verified by further experiments.

关键词： Immunomodulation Insulitis Insulin-producing cells Mesenchymal stem cells Streptozotocin Th1 cell

Genetic Structure and Relationships among Populations of the Caspian Bent-toed Gecko, Tenuidactylus caspius(Eichwald, 1831)(Sauria: Gekkonidae) in Northern Iran

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Asian Herpetological Research 2015年第4期6卷 331-338页

作者： Vida HOJATI eskandar Rastegar POUYANI Kazem PARIVAR Department of Biology Damghan Branch Islamic Azad University Department of Biology Faculty of Science Hakim Sabzevari University Department of Biology Tehran Science and Research Branch Islamic Azad University

The Caspian bent-toed gecko, Tenuidactylus caspius, belonging to the family Gekkonidae, is widely distributed across the northern half of Iran, especially along the southern coastal region of the Caspian Sea. It is regarded as a commensal species throughout its entire distribution. We investigated genetic variation and relationships among different populations of this species in Iran. Fragments of the mitochondrial cyt b（547 bp） and ND4（831 bp） genes were sequenced and analyzed in 64 and 28 specimens, respectively, from 21 geographically distant localities. Cyrtopodion scabrum was used as the outgroup taxon. The data showed no significant genetic variation within the populations of T. caspius in Iran. Nevertheless, populations of Khorasan and Semnan（especially Shahrood） in northeastern Iran showed greater divergence（p-distance = 2.1%） from other Iranian populations. The low genetic variation and homogeneous structure among populations of T. caspius on either side of the Elburz Mountains suggests that this species most likely has achieved its current distribution recently and as a result of anthropogenic activities.

关键词： mtDNA Tenuidactylus caspius Gekkonidae phylogeny homogeneity Iranian Plateau.

Hepatitis C virus transmission and its risk factors within families of patients infected with hepatitis C virus in southern Iran:Khuzestan

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World Journal of Gastroenterology 2006年第43期12卷 7025-7028页

作者： eskandar Hajiani Rahim Masjedizadeh Jalal Hashemi Mehrdad Azmi Tahereh Rajabi Division of Gastroenterology and HepatologyDepartment of Internal Medicine Ahwaz Jundishapur Universityof Medical Sciences Ahwaz Iran Division of Gastroenterology and Hepatology Department of pathology Ahwaz Jundishapur University ofMedical Sciences Ahwaz Iran

AIM: To determine whether hepatitis C virus (HCV) infection of index cases increases intrafamilial transmission (sexual and nonsexual contacts) of HCV. METHODS: In a case-control descriptive study we enrolled 300-household contacts of 60 index cases (40 males and 20 females) of HCV infection and 360 pair- matched controls in Ahwaz JundiShapour University Hospitals from August 1, 1998 to September 1, 2003. The control group consisted of first time blood donors referred to the Regional Blood Transfusion Organization. Serum samples and demographic data and a medical history including the existence of risk factors for HCV (after a questionnaire on the risk factors for parenteral exposure) were obtained from each subject. Antibodies to HCV were detected employing a commercially available second-generation enzyme immunoassay (EIA, Abbott Ⅱ). Positive serum specimens were retested using a second-generation recombinant immunoblot assay (RIBA-2) and a polymerase chain reaction for HCV RNA. Data analysis was carried out for intra-household clustering. RESULTS: Only 4 of 300 (1.33%) cases of household contacts without percutaneous risk factors were positive for HCV Ab while the remaining 296 family contacts were negative for anti-HCV. The mean age of the index cases was 28.4 (Std 15.22) years. The anti-HCV prevalences in parents, spouses, children of the index cases were 0.87% (1/115), 3.39% (2/59)) and 0.79% (1/126), respectively. Among couple partners negative for anti-HCV antibodies, the mean duration of the sexual relationship was 6 *** two-couple partners positive for anti-HCV antibodies married the index cases for longer than 15 years. The prevalence of positive HCV Ab among household contacts (1.33%) was not significantly higher than that in the controls (1%) (P > 0.06). CONCLUSION: Intrafamilial transmission of HCV is not the significant transmission route and sexual transmission does not seem to play a role in the intrafamilial spread of HCV infection. Intrafami

关键词： Intrafamilial transmission Hepatitis C virus Khuzestan South-west of Iran

Rediscovery of Microgecko helenae fasciatus(Schmidtler and Schmidtler, 1972) from Kermanshah Province, Western Iran with Notes on Taxonomy, Morphology, and Habitat

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Asian Herpetological Research 2015年第4期6卷 339-346页

作者： Ali GHOLAMIFARD Nasrullah RASTEGAR-POUYANI eskandar RASTEGAR-POUYANI Department of Biology Faculty of Science Razi University Iranian Plateau Herpetology Research Group (IPHRG) Faculty of Science Razi University Department of Biology Faculty of Science Hakim Sabzevari University

During extensive field work in the Zagros Mountains, western Iran, from October 2013 to November 2014, twenty five localities in different areas of the Kermanshah Province were investigated. Nineteen specimens of Schmidtler＇s dwarf gecko, Microgecko helenae fasciatus, were collected from six localities in western and southeastern regions of the Kermanshah Province. This new collection verifies the presence of M. h. fasciatus in the area after the description of Schmidtler and Schmidtler of the holotype specimen in 1972. All of the collected specimens are consistent with the described specimens in diagnostic characters, as have a uniform dorsal pattern with five distinct dark crossbars and white posterior margins as well as the higher number of dorsal scales between axilla and groin. Detailed morphology of the new specimens is discussed and compared with those of rare previous records. Taxonomy, distribution, and habitat types of this tiny gecko in the western foothills of the Zagros Mountains are also discussed.

关键词： Gekkonidae banded dwarf gecko Microgecko helenaefasciatus Zagros Mountains Iran

Prevalence of celiac disease in Iranian children with idiopathic short stature

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World Journal of Gastroenterology 2008年第48期14卷 7376-7380页

作者： Jalal Hashemi eskandar Hajiani HBB Shahbazin Rahim Masjedizadeh Navab Ghasemi Division of Gastroenterology and Hepatology Department of Internal Medicine Ahwaz Jundishapur University of Medical Sciences Division of Endocrinology and Diabetes center Department of Internal Medicine Ahwaz Jundishapur University of Medical Sciences Ahwaz Iran Department of Internal Medicine Ahwaz Jundishapur University of Medical Sciences Golestan Hospital

AIM： To determine the prevalence of celiac disease （CD） in children with idiopathic short stature （ISS） and the diagnostic value of immunoglobulin （Ig） A G antigliadin antibodies （AGA） and transglutaminase （TTG） antibodies for ***： A total of 104 children （49 male, 55 female） with ISS without a specific etiology were studied. Extensive endocrine investigations had shown no abnormalities in any subject. Anthropometric parameters and IgA AGA and IgA TTG antibodies were evaluated in this study group. These antibodies were measured by enzyme-linked immunosorbent assay. All patients were referred for an endoscopic intestinal biopsy. The biopsy samples were classified according to revised Marsh criteria （UEGW 2001）.RESULTS： We detected positive IgA TTG antibodies in 36 and IgA AGA in 35 of these patients. Thirty one IgA TTG antibody positive and 28 IgA AGA positive subjects showed histological abnormalities compatible with celiac disease （33.6%）. Sensitivity, specificity, positive predictive value （PPV） and negative predictive value for IgA AGA were found to be 80%, 88.4%, 77.8% and 89.7%, respectively. Sensitivity, specificity and PPV for IgA TTG antibodies were 88.6%, 94.2% and 88.6%, ***： We conclude that the prevalence of celiac disease is high in patients with ISS and it is important to test all children with ISS for celiac disease by measuring serologic markers and performing an intestinal biopsy.

关键词： Celiac disease Growth disorders Transglu-taminases Antibodies Gliadin

Genetic and Morphological Variations within Laudakia microlepis(Blanford, 1874)(Sauria: Agamidae) Populations in Southeastern Iran with Description of a New Subspecies

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Asian Herpetological Research 2015年第3期6卷 199-205页

作者： Nasser SANCHOOLI Hassan RAHIMIAN Nasrullah RASTEGAR-POUYANI eskandar RASTEGAR-POUYANI Faculty of Biological Sciences College of ScienceUniversity of Tehran Department of Biology Faculty of ScienceZabol University Department of Biology Faculty of ScienceRazi University Iranian Plateau Herpetology Research Group (IPHRG) Razi University Department of Biology Faculty of ScienceHakim Sabzevari University

A new subspecies of Laudakia microlepis（Blanford, 1874） is described, from Taftan Mountain in southeastern Iran, based on morphological and genetic characteristics. This new subspecies is distinguished from the nominal subspecies by having a yellowish head along with the following combination of characters： a relatively larger body size; different number of scales around middle of body; larger, weakly keeled, dorsal median scales arranged in 11–13 oblique longitudinal rows; 123–136 scales in a single row from posterior edge of gular fold to vent; 27–31 scales in the first complete whorl around the tail. The type locality of Laudakia microlepis taftanica ssp. nov., is hereby, reported as the Taftan Mountain, about 300 kilometer southeast of the nominal subspecies known range.

关键词： Laudakia microlepis taftanica ssp.nov. taxonomic status ND4 gene Sistan and Baluchistan province