535 research outputs found

    Preliminary report of the Fasıllar Survey

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    Fig. 1: Map of Beyşehir and Fasıllar The Fasıllar monument is located above the village of the same name, 15 km from the city of Beyşehir (Fig. 1). The site has been visited by numerous scholars since its discovery in the 19th century (Sterrett 1888: 163-166; Ramsay 1889: 170ff.; Perrot/Chipiez 1890: 222-223; Jüthner et al. 1903: 16-18, fig. 4-5; Ramsay 1907: 133-134, fig. 7; Garstang 1910: 175-176). However, before 2012, no authorized archaeological project had been undertaken in relation t..

    Osteoselection supported by phase separeted polymer blend films

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    Cataloged from PDF version of article.The instability of implants after placement inside the body is one of the main obstacles to clinically succeed in periodontal and orthopedic applications. Adherence of fibroblasts instead of osteoblasts to implant surfaces usually results in formation of scar tissue and loss of the implant. Thus, selective bioadhesivity of osteoblasts is a desired characteristic for implant materials. In this study, we developed osteoselective and biofriendly polymeric thin films fabricated with a simple phase separation method using either homopolymers or various blends of homopolymers and copolymers. As adhesive and proliferative features of cells are highly dependent on the physicochemical properties of the surfaces, substrates with distinct chemical heterogeneity, wettability, and surface topography were developed and assessed for their osteoselective characteristics. Surface characterizations of the fabricated polymer thin films were performed with optical microscopy and SEM, their wettabilities were determined by contact angle measurements, and their surface roughness was measured by profilometry. Long-term adhesion behaviors of cells to polymer thin films were determined by F-actin staining of Saos-2 osteoblasts, and human gingival fibroblasts, HGFs, and their morphologies were observed by SEM imaging. The biocompatibility of the surfaces was also examined through cell viability assay. Our results showed that heterogeneous polypropylene polyethylene/polystyrene surfaces can govern Saos-2 and HGF attachment and organization. Selective adhesion of Saos-2 osteoblasts and inhibited adhesion of HGF cells were achieved on micro-structured and hydrophobic surfaces. This work paves the way for better control of cellular behaviors for adjustment of cell material interactions. © 2014 Wiley Periodicals, Inc

    Combined XPS and contact angle studies of ethylene vinyl acetate and polyvinyl acetate blends

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    Cataloged from PDF version of article.In this study, we prepared thin films by blending ethylene vinyl acetate copolymers (EVA) containing 12-33 (wt.%) vinyl acetate (VA) with polyvinyl acetate (PVAc) and high density polyethylene homopolymers. Large area micropatterns having controlled protrusion sizes were obtained by phase-separation especially for the PVAc/EVA-33 blends using dip coating. These surfaces were characterized by XPS and contact angle measurements. A reasonably linear relation was found between the VA content on the surface (wt.%) obtained from XPS analysis and the VA content in bulk especially for PVAc/EVA-33 blend surfaces. PE segments were more enriched on the surface than that of the bulk for pure EVA copolymer surfaces similar to previous reports and VA enrichment was found on the EVA/HDPE blend surfaces due to high molecular weight of HDPE. Water theta(e) decreased with the increase in the VA content on the blend surface due to the polarity of VA. A good agreement was obtained between gamma(-)(s) and atomic oxygen surface concentration with the increase of VA content. The applicability of Cassie-Baxter equation was tested and found that it gave consistent results with the experimental water contact angles for the case where VA content was lower than 55 wt.% in the bulk composition. (C) 2011 Elsevier B. V. All rights reserved

    Reducing CSF partial volume effects to enhance diffusion tensor imaging metrics of brain microstructure

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    Technological advances over recent decades now allow for in vivo observation of human brain tissue through the use of neuroimaging methods. While this field originated with techniques capable of capturing macrostructural details of brain anatomy, modern methods such as diffusion tensor imaging (DTI) that are now regularly implemented in research protocols have the ability to characterize brain microstructure. DTI has been used to reveal subtle micro-anatomical abnormalities in the prodromal phase ofº various diseases and also to delineate “normal” age-related changes in brain tissue across the lifespan. Nevertheless, imaging artifact in DTI remains a significant limitation for identifying true neural signatures of disease and brain-behavior relationships. Cerebrospinal fluid (CSF) contamination of brain voxels is a main source of error on DTI scans that causes partial volume effects and reduces the accuracy of tissue characterization. Several methods have been proposed to correct for CSF artifact though many of these methods introduce new limitations that may preclude certain applications. The purpose of this review is to discuss the complexity of signal acquisition as it relates to CSF artifact on DTI scans and review methods of CSF suppression in DTI. We will then discuss a technique that has been recently shown to effectively suppress the CSF signal in DTI data, resulting in fewer errors and improved measurement of brain tissue. This approach and related techniques have the potential to significantly improve our understanding of “normal” brain aging and neuropsychiatric and neurodegenerative diseases. Considerations for next-level applications are discussed

    L-MYC gene polymorphism and risk of thyroid cancer

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    L-myc gene polymorphism is a representative genetic trait responsible for an individual’s susceptibility to several cancers. However, there have been no reports concerning the association between thyroid cancer and L-myc gene polymorphism. Aim: To analyze the distribution of L-myc gene polymorphism in Turkish patients with thyroid disorders and thyroid cancers. Methods: We used a molecular genotyping method, polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP). We studied 138 patients of whom 47 had multinodular goiter, 13 had follicular cancer and 69 had papillar cancer, in comparison with control group of 109 healthy individuals. Results: No significant difference in the distribution of genotypes was observed between thyroid patients and controls. Carrying SS or LS genotype revealed a 1.96-fold (95% CI 0.573–6.706) risk for the occurrence of follicular cancer when compared with controls, and 3.11-fold (95% CI 0.952–10.216), when compared with multinodular goiter patients (p = 0.04). Conclusion: We suggest that L-myc genotype profiling together with other susceptibility factors, may be useful in the screening for thyroid nodular malignancy.Для ряда опухолей человека показана корреляция между риском развития опухоли и определенным вариантом гена L-MYC. Данные о наличии такой связи при раке щитовидной железы к настоящему времени отсутствуют. Цель: проанализировать распределение полиморфных типов гена L-MYC в популяции больных с доброкачественными и злокачественными поражениями щитовидной железы, включая рак щитовидной железы, в Турции. Методы: для анализа полиморфизма гена L-MYC использован метод молекулярного генотипирования, в частности, метод определения полиморфизма длины рестрикционных фрагментов, основанный на полимеразной цепной реакции (PCR-RFLP). Определение проводили в лейкоцитах 138 больных, в том числе 48 больных с узловым зобом, 13 больных фолликулярным раком щитовидной железы и 69 больных папиллярным раком. Контрольную группу составляли 109 здоровых лиц. Результаты: статистически достоверных различий в распределении исследуемых генотипов у больных с патологией щитовидной железы и здоровых лиц не выявили. Показано, что относительный риск фолликулярного рака щитовидной железы у больных-носителей генотипа SS или LS составляет 1,96 по сравнению со здоровыми лицами (при 95% доверительном интервале от 0,573 до 6,706) и 3,11 по сравнению с больными с узловым зобом (при 95% доверительном интервале от 0,952 до 10,216) (р = 0,04). Выводы: по нашему предположению, определение профиля полиморфизма гена L-MYC с учетом других факторов, определяющих предрасположенность к развитию опухолей, может быть полезным при скрининге озлокачествления узелковых образований щитовидной железы

    Topography driven spreading

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    Roughening a hydrophobic surface enhances its nonwetting properties into superhydrophobicity. For liquids other than water, roughness can induce a complete rollup of a droplet. However, topographic effects can also enhance partial wetting by a given liquid into complete wetting to create superwetting. In this work, a model system of spreading droplets of a nonvolatile liquid on surfaces having lithographically produced pillars is used to show that superwetting also modifies the dynamics of spreading. The edge speed-dynamic contact angle relation is shown to obey a simple power law, and such power laws are shown to apply to naturally occurring surfaces
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