78 research outputs found

    A Radiotracer study of the adsorption behaviour of aqueous Ba2+ ions on nonoparticles of zero-valent iron

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    Cataloged from PDF version of article.Recently, iron nanoparticles are increasingly being tested as adsorbents for various types of organic and inorganic pollutants. In this study, nanoparticles of zero-valent iron (NZVI) synthesized under atmospheric conditions were employed for the removal of Ba2+ ions in a concentration range 10-3 to 10-6 M. Throughout the study, 133Ba was used as a tracer to study the effects of time, concentration, and temperature. The obtained data was analyzed using various kinetic models and adsorption isotherms. Pseudo-second-order kinetics and Dubinin-Radushkevich isotherm model provided the best correlation with the obtained data. Observed thermodynamic parameters showed that the process is exothermic and hence enthalpy-driven. © 2007 Elsevier B.V. All rights reserved

    Impact of Vitamin D Supplementation on Arterial Vasomotion, Stiffness and Endothelial Biomarkers in Chronic Kidney Disease Patients

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    Background: Cardiovascular events are frequent and vascular endothelial function is abnormal in patients with chronic kidney disease (CKD). We demonstrated endothelial dysfunction with vitamin D deficiency in CKD patients; however the impact of cholecalciferol supplementation on vascular stiffness and vasomotor function, endothelial and bone biomarkers in CKD patients with low 25-hydroxy vitamin D [25(OH)D] is unknown, which this study investigated. Methods: We assessed non-diabetic patients with CKD stage 3/4, age 17–80 years and serum 25(OH)D ,75 nmol/L. Brachial artery Flow Mediated Dilation (FMD), Pulse Wave Velocity (PWV), Augmentation Index (AI) and circulating blood biomarkers were evaluated at baseline and at 16 weeks. Oral 300,000 units cholecalciferol was administered at baseline and 8-weeks. Results: Clinical characteristics of 26 patients were: age 50614 (mean61SD) years, eGFR 41611 ml/min/1.73 m2, males 73%, dyslipidaemia 36%, smokers 23% and hypertensives 87%. At 16-week serum 25(OH)D and calcium increased (43616 to 84629 nmol/L, p,0.001 and 2.3760.09 to 2.4260.09 mmol/L; p = 0.004, respectively) and parathyroid hormone decreased (10.868.6 to 7.464.4; p = 0.001). FMD improved from 3.163.3% to 6.163.7%, p = 0.001. Endothelial biomarker concentrations decreased: E-Selectin from 566662123 to 525662058 pg/mL; p = 0.032, ICAM-1, 3.4560.01 to 3.1061.04 ng/mL; p = 0.038 and VCAM-1, 54633 to 42633 ng/mL; p = 0.006. eGFR, BP, PWV, AI, hsCRP, von Willebrand factor and Fibroblast Growth Factor-23, remained unchanged. Conclusion: This study demonstrates for the first time improvement of endothelial vasomotor and secretory functions with vitamin D in CKD patients without significant adverse effects on arterial stiffness, serum calcium or FGF-23. Trial Registration: ClinicalTrials.gov NCT0200571

    Editorial of Special Issue of National Identities: Alevism as an ethno-religious identity: Contested boundaries

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    No abstract for editorial but this is the opening paragraph: This special issue on Alevism and trans/national Alevi identity critically engages with the relationship between religion, ethnicity and national identity. The core issues are as follows: • how ethnicity and religion are conceptualised for a relatively invisible ethnic group in different national contexts; • how religion and ethnicity intersect when Alevism is both a faith and an ethnic identity, especially when conceptions of that identity are contested; • how identity is shaped through state policies within different national policy contexts and how etic definitions of minority communities are constructed by the state or other agencies with the power to impose them on the community in contrast to the emic or self-definitions of Aleviness from within the Alevi community; • how despite the fragmented, heterogeneous nature of Alevi communities, there is also a sense of a single, transnational imaginary community, at least for the purposes of political assimilation/integration and activism; • how education and other arenas of political, religious and cultural engagement at local, national and transnational levels create the possibilities, both positively and negatively, for future action/policy to situate minority ethnic communities

    Effect of Molecular Architecture on the Polyelectrolyte Structuring under Confinement

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    Polyelectrolytes in thin liquid films

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    Age, size and growth of the southern crested newt Triturus karelinii (Strauch 1870) in a population from Bozdag (Western Turkey)

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    International audienceWe studied the characteristics of bone growth assessed by skeletochronology in a southern crested newt Triturus karelinii (Urodela) population from Western Turkey. The timing and patterns of bone arrested growth were observed using the phalanges of juveniles and adults that were caught in spring at a breeding site. A metamorphosis line was found in the juveniles. In some adults, a classical succession of single lines of arrested growth was observed in about 50% of the cross sections. However, the other adults exhibited a succession of double lines of arrested growth in their phalanges. Due to the and summer and cold winter climate in the Bozdag region ( 1200 m a.s.l.), we argue that in this last case, the lines of arrested growth were deposited during both the summer (aestivation) and winter (wintering). Body length, age and growth were similar in males and females. The age of maturity was 3 to 4 years old and longevity was 8 and 11 years in males and females respectively. Body length and age among taxonomically related large bodied newts of the T. cristatus complex were reported from populations experiencing various environmental conditions. Body length and age at maturity were similar to that observed in other newt species. However, longevity seems to be lower than expected in the T karelinii studied population. We hypothesized that the and climate of Bozdag could cause a higher mortality risk during the terrestrial phase of the life cycle. Studying more populations exposed to various conditions is clearly needed to assess interpopulational variation of these life-history traits in this newt species

    Age, size and growth of the endemic Anatolian mountain frog Rana holtzi from Turkey

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    International audienceWe estimated the age, size and growth patterns of a mountain ranid, Rana holtzi, from Central Anatolia, using skeletochronology. We used lines of arrested growth (LAGs) recorded in phalanges to estimate the age of juveniles and adults. Results showed that age at maturity in this population was 4-5 years (median age of juveniles was 3.5 yrs and minimum age for adults was 4.0 yrs for both sexes). Median ages of males and females were similar (6 yrs) and longevity reached 8.0 yrs for males and 10.5 yrs for females. Mean body and tibia length of males was significantly larger than that of females. Growth of the Anatolian mountain frog was well described by the von Bertalanffy model, and males and females did not differ in growth parameters. These demographic parameters are compared with those obtained with other amphibians, especially ranids. The sexual size dimorphism observed-larger males than females-has rarely been observed previously and should prompt observers to collect other biological information on this rare endemic species
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