1,462 research outputs found

    Geological features and marble production qualities of Western Turkey

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    Purpose. Isparta Angle occurs along the Mesozoic carbonate axis. Carbonated rocks forming the Taurus belt are continuous with allochthonous and autochthonous features. The rocks in the region are abnormally contacted with each other and can be found as allochthons on each other. The contacts between the tectono-stratigraphic units are commonly tectonic with the carbonate platforms forming the autochthonous basement to the west and east. For this reason, the initial relations between the rock masses and their initial geographical locations are not known. Methods. Some of the carbonated rocks show similar characteristics to each other in terms of sedimentation environment, stratigraphic relations and some other characteristics; but they are separated from each other by different characteristics throughout the belt. Findings. In this study, relationships between mass and material properties of marbles, which are produced in the allochthonous and autochthonous parts of the carbonated rocks in the western part of the Taurus belt, were investigated. Originality. As a result of this study, it has been determined that the mass and material characteristics of autochthonous limestones are better in quality than those of allochthonous limestones. Practical implications. Marble production qualities and block efficiency of allochthonous and autochthonous rocks have been evaluated.Мета. Виявлення геологічних особливостей залягання і властивостей автохтонних та алохтонних карбонатних порід Західної Туреччини для можливості їх промислового освоєння. Методика. Аналіз геологічної й тектонічної карт Південно-Західної Туреччини для вивчення стратиграфічних і структурних особливостей автохтонних та алохтонних карбонатних порід. Досліджено фізико-механічні властивості карбонатних порід Таврського поясу. Міцність зразків на розтяг були виконані відповідно до процедур, рекомендованих ISRM. Програма лабораторних випробувань включала визначення природної маси одиниці, водонасиченості, пористості, міцності на одноосьове стиснення, втрати на стирання. Результати. Відзначено, що у Таврському поясі карстифікація і багатошарові надвиги, що впливають на автохтонні вапняки й пов’язані з ними системи розломів і тріщин зсуву, є провідними факторами, які безпосередньо впливають на виробництво мармуру та вихід блоків у регіоні. Надана кількісна оцінка фізико-механічним властивостями алохтонних та автохтонних карбонатних порід. Акцентується увага щодо необхідності вимірювання на поверхнях порід системи тріщинуватості й за допомогою комп’ютерної обробки визначення ідеальних розмірів блоків у процесі видобутку. Встановлено, що для збільшення виходу блоків під час роботи їх необхідно різати перпендикулярно домінуючим тріщинам і поверхням руйнування. Рекомендується всі необхідні стратиграфічні вимірювання проводити у польових умовах і в разі, якщо у досліджуваній зоні є карстифіковані й заповнені зони, вони повинні бути враховані у стратиграфічних картах і розрізах. Наукова новизна. Для умов Таврського поясу встановлено, що масові та матеріальні характеристики автохтонних вапняків перевершують за якістю характеристики алохтонних вапняків, і вони можуть розглядатися як першочергові родовища для видобутку блочного каменю відкритим способом. Практична значимість. Проведення інженерно-геологічних робіт до процесу видобутку мармурового блочного каменю дозволить уточнити запаси й підвищити привабливість родовища до освоєння, а також знизити майбутні виробничі витрати шляхом визначення необхідної структури виробництва відповідно до даних досліджень.Цель. Выявление геологических особенностей залегания и свойств автохтонных и аллохтонных карбонатных пород Западной Турции для возможности их промышленного освоения. Методика. Анализ геологической и тектонической карт Юго-Западной Турции для изучения стратиграфических и структурных особенностей автохтонных и аллохтонных карбонатных пород. Исследованы физико-механические свойства карбонатных пород Таврского пояса. Прочность образцов на растяжение были выполнены в соответствии с процедурами, рекомендованными ISRM. Программа лабораторных испытаний включала определение естественной массы единицы, водонасыщенности, пористости, прочности на одноосное сжатие, потери на истирание. Результаты. Отмечено, что в Таврском поясе карстификация и многослойные надвиги, воздействующие на автохтонные известняки и связанные с ними системы разломов и трещин сдвига, являются ведущими факторами, непосредственно влияющими на производство мрамора и выход блоков в регионе. Дана количественная оценка физико-механическим свойствам аллохтонных и автохтонных карбонатных пород. Акцентируется внимание о необходимости измерения на поверхностях пород системы трещиноватости и при помощи компьютерной обработки определения идеальных размеров блоков в процессе добычи. Установлено, что для увеличения выхода блоков во время работы их необходимо резать перпендикулярно доминирующим трещинам и поверхностям разрушения. Рекомендуется все необходимые стратиграфические измерения производить в полевых условиях и в случае, если в исследуемой зоне имеются карстифицированные и заполненные зоны, они должны быть учтены в стратиграфических картах и разрезах. Научная новизна. Для условий Таврского пояса установлено, что массовые и материальные характеристики автохтонных известняков превосходят по качеству характеристики аллохтонных известняков, и они могут рассматриваться как первоочередные месторождения для добычи блочного камня открытым способом. Практическая значимость. Проведение инженерно-геологических работ до процесса добычи мраморного блочного камня позволит уточнить запасы и повысить привлекательность месторождения к освоению, а также снизить будущие производственные потери путем определения подходящей структуры производства в соответствии с данными исследованиями.The authors would like to thank the anonymous reviewers for their valuable comments and suggestions to improve the quality of the paper. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors

    Effects of thermal annealing on the morphology of the AlxGa(1x)N films

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    Cataloged from PDF version of article.Effects of thermal annealing on the morphology of the AlxGa(1-x)N films with two different high Al-contents (x=0.43 and 0.52) have been investigated by atomic force microscopy (AFM). The annealing treatments were performed in a nitrogen (N-2) gas ambient as short-time (4 min) and long-time (30 min). Firstly, the films were annealed as short-time in the range of 800-950 degrees C in steps of 50-100 degrees C. The surface root-mean-square (rms) roughness of the films reduced with increasing temperature at short-time annealing (up to 900 degrees C), while their surface morphologies were not changed. At the same time, the degradation appeared on the surface of the film with lower Al-content after 950 degrees C. Secondly, the Al0.43Ga0.57N film was annealed as long-time in the range of 1000-1200 degrees C in steps of 50 degrees C. The surface morphology and rms roughness of the film with increasing temperature up to 1150 degrees C did not significantly change. Above those temperatures, the surface morphology changed from step-flow to grain-like and the rms roughness significantly increased. (C) 2009 Elsevier Ltd. All rights reserved

    Microstructural defect properties of InGaN/GaN blue light emitting diode structures

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    Cataloged from PDF version of article.In this paper, we study structural and morphological properties of metal-organic chemical vapour deposition-grown InGaN/GaN light emitting diode (LED) structures with different indium (In) content by means of high-resolution X-ray diffraction, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) and current-voltage characteristic (I-V). We have found out that the tilt and twist angles, lateral and vertical coherence lengths of mosaic blocks, grain size, screw and edge dislocation densities of GaN and InGaN layers, and surface roughness monotonically vary with In content. Mosaic defects obtained due to temperature using reciprocal lattice space map has revealed optimized growth temperature for active InGaN layer of MQW LED. It has been observed in this growth temperature that according to AFM result, LED structure has high crystal dimension, and is rough whereas according to PL and FTIR results, bandgap energy shifted to blue, and energy peak half-width decreased at high values. According to I-V measurements, it was observed that LED reacted against light at optimized temperature. In conclusion, we have seen that InGaN MQW structure's structural, optical and electrical results supported one another

    Screening of medicinal plant extracts as novel DNA gyrase inhibitors

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    Bioactivities of a number of medicinal plants; Alkanna tinctoria (L.) Tausch, Alnus glutinosa (L.) Gaertn., Calamintha nepeta Willk. and C. nepeta, Centaurea iberica Trevir. ex Spreng., Citrus paradisi Macfad., C. paradisi, Citrus sinensis (L.) Osbeck, Colutea cilicica Boiss. & Balansa, Cotinus coggygria Scop., Cuscuta arvensis Beyr. ex Engelm., Equisetum palustre L., Lapsana communis L., Laurus nobilis L., Olea europea L., Plantago major L., Rhus coriaria L, Salvia verticillata L., Sambucus ebulus L., Sedum acre L, Thymus capitatus (L.) Hoffmanns. & Link, T. capitatus, Thymbra spicata L., T. spicata (n: 20), which are used for the prevention and treatment of diverse diseases, were investigated. The antimicrobial activities of extracts were evaluated using broth microdilution assay. The cytotoxicities of extracts were investigated on HeLa cell line by MTT assay. Statistical analysis was performed using GraphPad Prism (5.0). The effects of the extracts, which have the highest antimicrobial activity, on the Escherichia coli and Staphylococcus aureus DNA gyrase gene expression were determined by using quantitative reverse transcription polymerase chain reaction (qRT-PCR). The MICs (µg/ml) of extracts were determined as 32-64, 2-128, 8-128,1-128, 4-128 against Gram-positive, Gram-negative bacteria, yeasts, dermatophytes, and Mycobacterium spp., respectively. No cytotoxicity has been observed in plant extracts tested. DNA gyrase activity was determined for T. capitatus-SFE (128 µg/mL) and L. nobilis-Hx (128 µg/mL) extracts according to the inhibition of DNA gyrase gene expression. Overall, T. capitatus-SFE and L. nobilis-Hx are good candidates for further antimicrobial studies.

    Sulfatide and its synthetic analogues recognition by Moraxella catarrhalis

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    Moraxella catarrhalis is one of the major pathogens of respiratory and middle ear infections. Attachment of this bacterium to the surface of human pharyngeal epithelial cells is the first step in the pathogenesis of infections. This study revealed that sulfatide might act as a binding molecule for the attachment of M. catarrhalis to human pharyngeal epithelial cells. Furthermore, six different synthetic sulfatides were found to inhibit the attachment of M. catarrhalis significantly at an optimum concentration of 10 μg/ml. Synthetic sulfatides may have the potential to be used as a therapy to prevent M. catarrhalis infections

    Superpulsed low-level laser therapy protects skeletal muscle of mdx mice against damage, inflammation and morphological changes delaying dystrophy progression.

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    Aim: To evaluate the effects of preventive treatment with low-level laser therapy (LLLT) on progression of dystrophy in mdx mice. Methods: Ten animals were randomly divided into 2 experimental groups treated with superpulsed LLLT (904 nm, 15 mW, 700 Hz, 1 J) or placebo-LLLT at one point overlying the tibialis anterior muscle (bilaterally) 5 times per week for 14 weeks (from 6th to 20th week of age). Morphological changes, creatine kinase (CK) activity and mRNA gene expression were assessed in animals at 20th week of age. Results: Animals treated with LLLT showed very few morphological changes in skeletal muscle, with less atrophy and fibrosis than animals treated with placebo-LLLT. CK was significantly lower (p = 0.0203) in animals treated with LLLT (864.70 U.l−1, SEM 226.10) than placebo (1708.00 U.l−1, SEM 184.60). mRNA gene expression of inflammatory markers was significantly decreased by treatment with LLLT (p<0.05): TNF-α (placebo-control = 0.51 µg/µl [SEM 0.12], - LLLT = 0.048 µg/µl [SEM 0.01]), IL-1β (placebo-control = 2.292 µg/µl [SEM 0.74], - LLLT = 0.12 µg/µl [SEM 0.03]), IL-6 (placebo-control = 3.946 µg/µl [SEM 0.98], - LLLT = 0.854 µg/µl [SEM 0.33]), IL-10 (placebo-control = 1.116 µg/µl [SEM 0.22], - LLLT = 0.352 µg/µl [SEM 0.15]), and COX-2 (placebo-control = 4.984 µg/µl [SEM 1.18], LLLT = 1.470 µg/µl [SEM 0.73]). Conclusion: Irradiation of superpulsed LLLT on successive days five times per week for 14 weeks decreased morphological changes, skeletal muscle damage and inflammation in mdx mice. This indicates that LLLT has potential to decrease progression of Duchenne muscular dystrophy

    Device-Compatible Chiroptical Surfaces through Self-Assembly of Enantiopure Allenes

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    Chiroptical methods have been proven to be superior compared to their achiral counterparts for the structural elucidation of many compounds. To expand the use of chiroptical systems to everyday applications, the development of functional materials exhibiting intense chiroptical responses is essential. Particularly, tailored and robust interfaces compatible with standard device operation conditions are required. Herein, we present the design and synthesis of chiral allenes and their use for the functionalization of gold surfaces. The self-assembly results in a monolayer-thin room-temperature-stable upstanding chiral architecture as ascertained by ellipsometry, X-ray photoelectron spectroscopy, and near-edge X-ray absorption fine structure. Moreover, these nanostructures anchored to device-compatible substrates feature intense chiroptical second harmonic generation. Both straightforward preparation of the device-compatible interfaces along with their chiroptical nature provide major prospects for everyday applications

    Skewed X inactivation in an X linked nystagmus family resulted from a novel, p.R229G, missense mutation in the FRMD7 gene

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    Aims: This study aimed to identify the underlying genetic defect of a large Turkish X linked nystagmus (NYS) family. Methods: Both Xp11 and Xq26 loci were tested by linkage analysis. The 12 exons and intron-exon junctions of the FRMD7 gene were screened by direct sequencing. X chromosome inactivation analysis was performed by enzymatic predigestion of DNA with a methylation-sensitive enzyme, followed by PCR of the polymorphic CAG repeat of the androgen receptor gene. Results: The family contained 162 individuals, among whom 28 had NYS. Linkage analysis confirmed the Xq26 locus. A novel missense c.686C>G mutation, which causes the substitution of a conserved arginine at amino acid position 229 by glycine (p.R229G) in exon 8 of the FRMD7 gene, was observed. This change was not documented in 120 control individuals. The clinical findings in a female who was homozygous for the mutation were not different from those of affected heterozygous females. Skewed X inactivation was remarkable in the affected females of the family. Conclusions: A novel p.R229G mutation in the FRMD7 gene causes the NYS phenotype, and skewed X inactivation influences the manifestation of the disease in X linked NYS females
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