Ahi Evran University

About: Ahi Evran University is a education organization based out in Kırşehir, Turkey. It is known for research contribution in the topics: Density functional theory & Ab initio. The organization has 842 authors who have published 2270 publications receiving 21904 citations.

The relationship between oxidative stress and preeclampsia. The serum ischemia-modified albumin levels and thiol/disulfide homeostasis.

Abstract: Objective Preeclampsia (PE) is a dangerous complication of pregnancy and still a major cause of maternal-fetal morbidity and mortality. Its etiology remains largely unknown, but researchers have suggested oxidative stress-mediated inflammation for the same. The purpose of this study is to investigate the relationship between oxidative stress and PE as well as the usability of oxidative stress indicators such as serum ischemia-modified albumin (IMA) levels and thiol/disulfide balance in the prediction of PE. Materials and Methods The study included 47 pregnant women with PE and 57 healthy pregnant women. We measured their serum IMA, native thiol, total thiol, and disulfide levels. Additionally, we determined the optimal cutoff values via the receiver operating characteristic curve analysis. Results There were no differences between the two groups with respect to the maternal age, body mass index, gravida, and parity. The native and total thiol levels were found to be low when the disulfide and IMA levels were high in the patients with PE (p<0.05). When the IMA level was corrected by the albumin level (IMAR), the significant difference between the two groups disappeared. We also found that the native and total thiol concentrations were correlated with the systolic and diastolic blood pressures. The optimal cut-off values calculated for the prediction of PE were as follows: 178.45 µmol/L (with sensitivity of 72% and specificity of 83%) for native thiol, 232.55 µ mol/L (with a sensitivity of 75% and specificity of 85%) for total thiol, and 29.05 µmol/L (with sensitivity of 65% and specificity of 72%) for disulfide. Conclusion The balance of thiol/disulfide may play a role in the pathogenesis of PE and could be used as a biological marker for PE.

The effects of seasonal heavy-metal pollution of Ladik Lake on pike fish (Esox lucius)

Abstract: Ladik Lake (Samsun, Turkey) is a natural landscape under the threat of pollution because of urban, agricultural and industrial activities. In this study, accumulation of heavy metals (Al, Ba, Cr, C...

Karyotype, C-banding and AgNORs of two endemic leuciscine fish, Pseudophoxinuscrassus (Ladiges, 1960) and P.hittitorum Freyhof & Özulug, 2010 (Teleostei, Cyprinidae).

Abstract: The genus Pseudophoxinus Bleeker, 1860 is found in a wide range of habitats in central Anatolia, but it is not well known from a cytogenetic aspect. In this study the first karyotypic description of the spring minnows Pseudophoxinus crassus (Ladiges, 1960) and Pseudophoxinus hittitorum Freyhof & Ozulug, 2010 by means of conventional methods (Giemsa staining, C-banding, silver nitrate impregnation (Ag-NORs)) was performed. Both species are endemic and have restricted distributions in Central Anatolia. Pseudophoxinus crassus and Pseudophoxinus hittitorum have the same diploid chromosome number, 2n = 50, patterns of distribution of constitutive heterochromatin (CH), and localization of nucleolus organizer regions (NORs), but differ in their karyotypic formulae (KFs). The C-banding technique revealed clear pericentromeric blocks of CH in many chromosomes; Ag-NORs treatment revealed consistent positive signals at the end of the short arms of a submetacentric chromosome pair, likely homologous in both species. The karyotypic differences found between these species can be used for their taxonomical study.

Investigation of carrier transport mechanisms in the Cu–Zn–Se based hetero-structure grown by sputtering technique1

Abstract: In this paper, we present results of the electrical characterization of n-Si/p-Cu–Zn–Se hetero-structure. Sputtered film was found in Se-rich behavior with tetragonal polycrystalline nature along w...

Phase transformation of 6H-SiC at high pressure: An ab initio constant-pressure study

Abstract: We apply a constant-pressure ab initio technique to investigate the high-pressure phase transformation of 6H-SiC and show that it transforms into a rocksalt structure This phase change proceeds in two stages: 6H-SiC is first compressed along the c-direction and then it undergoes a shear deformation on the a-b planes This transformation mechanism is quite similar to that of the wurtzite-to-rocksalt observed in 2H-SiC but there is no metastable phase identified along this path The 6H-to-RS phase transition is also analyzed from the energy volume calculations The computed transition parameters agree well with the experimental data