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    An experimental design approach for the separation of thorium from rare earth elements
    (Elsevier Science Bv, 2018) Altas, Y.; Tel, H.; Inan, S.; Sert, S.; Cetinkaya, B.; Sengul, S.; Ozkan, B.
    As a part of technological evaluation of Eskisehir-Beylikahir thorium ore of Turkey, a novel study on the separation of thorium from oxalate concentrate including Th, La, Ce, Pr, Nd, Sm, Eu, Gd were carried out. As a first step, thorium-rare earth elements (REEs) oxalate concentrate was precipitated from nitric acid solution by the addition of 100% excess of oxalic acid amount necessary for stoichiometry. The concentrations of Th and REEs in the oxalate concentrate were chosen to simulate the oxalate intermediate product previously obtained from leach liqueur. Separation of thorium from REEs is mainly based on their significant solubility differences in ammonium oxalate solution. The dissolution conditions of thorium-REEs oxalate concentrate were investigated using central composite design (CCD) with three independent variables at five levels. The effect of independent variables such as contact time, amount of precipitate and the concentration of ammonium oxalate (AOX) solution on the thorium dissolution yield (%) were investigated. Analysis of variance (ANOVA) revealed that the effect of precipitate amount and the effect of ammonium oxalate concentration were found significant on the separation of thorium from Th-REEs concentrate. Probability F-value (F = 7 x 10(-6)) and correlation coefficient (R-2 = 0.96) indicate that a proposed model fits the experimental data well. At the optimum conditions the thorium dissolution yield was achieved to 96.66 +/- 2.16%.
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    Extraction and separation studies of rare earth elements using Cyanex 272 impregnated Amberlite XAD-7 resin
    (Elsevier Science Bv, 2018) Inan, S.; Tel, H.; Sert, S.; Cetinkaya, B.; Sengul, S.; Ozkan, B.; Altas, Y.
    As a part of technological evaluation of Eskisehir-Beylikahir thorium-Rare Earth Elements (REEs) ore of Turkey, a novel study investigating the extraction behaviours of light REEs for Cyanex 272 impregnated Amberlite XAD-7 resin was carried out. Solvent impregnated resin (SIR) was prepared by the impregnation of kerosene diluted Cyanex 272 onto Amberlite XAD-7 resin. SIR was characterized by FTIR, SEM, TGA-DSC, surface area and porosity analyses. The usability of Cyanex 272 impregnated XAD-7 for the extraction of La, Pr, Nd, Sm, Eu and Gd from nitric acid solution was investigated by batch experiments. Parameters affecting the uptake of these metal ions such as pH, contact time and liquid/solid (V/m) ratio were studied. Experimental data indicated that REEs have a tendency to behave as two separate groups as La, Pr, Nd and Sm, Eu, Gd. Light elements are being displaced by the heavier elements as they load up. Kinetic data fit the pseudo second order model for each element and the capacity values at the equilibrium were obtained as 11.1, 0.56, 1.69, 0.75, 0.10 and 0.25 mg g(-1) for La, Pr, Nd, Sm, Eu and Gd, respectively. Complete stripping of Pr(III) Nd(III), Gd(III) and 95.1% of Eu(III) ions were achieved by using 0.1 mol L-1 HNO3 in one stage batch contact.
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    SCREENING OF PROP-1, LHX2 AND POU1F1 MUTATIONS IN PATIENTS WITH ECTOPIC POSTERIOR PITUITARY GLAND
    (Editura Acad Romane, 2018) Korkmaz, H. A.; Karaarslan, U.; Eraslan, C.; Atila, D.; Hazan, F.; Barisik, V.; Ata, E. S.; Etlik, O.; Yildiz, M.; Ozkan, B.
    Objective. Ectopic posterior pituitary gland (EPP) is usually characterized by an abnormal pituitary stalk and hypoplasia of the anterior hypophysis. The genetic mechanisms involved in the development of EPP remain uncertain. The aim of this study is to determine whether mutations in the three genes, PROP-1, LHX2, and POU1F1, are associated with the risk for and the characteristics of EPP. Methods. In the Endocrinology Outpatient Clinic of "Dr. Behcet Uz" Children's Hospital, 27 patients with EPP were submitted to sequencing analyses of the PROP-1, LHX2, and POU1F1 genes. Results. Growth hormone, thyrotropin, corticotropin, gonadotropin, and vasopressin deficiency were observed in 22 (81.5%), 23 (85.2%), 17 (63%), 14 (51.9%), and two (7.4%) patients. Thirteen patients (48.1%) presented with hyperprolactinemia. Fourteen patients (51%) had a history of birth dystocia, and 12 cases (42.1%) had a history of breech presentation. Central nervous system abnormalities included five cases with corpus callosum agenesis, one case with schizencephaly, and one case with Chiari type 1 malformation. We identified a homozygous p.S109* mutation in exon 2 in one male patient with EPP and two different PROP] gene polymorphisms (A142T or c.109+3 G>A polymorphism) in thirteen patients. Conclusions. Our results suggest that PROP1 gene abnormalities might explain the genetic mechanisms involved in the development of EPP.