41 research outputs found
Novel Hybrid Scaffolds for the Cultivation of Osteoblast Cells
No full textTurkoglu Sasmazel, Hilal/0000-0002-0254-4541In this study, natural biodegradable polysaccharide, chitosan, and synthetic biodegradable polymer, poly(epsilon-caprolactone) (PCL) were used to prepare 3D, hybrid polymeric tissue scaffolds (PCL/chitosan blend and PCL/chitosan/PCL layer by layer scaffolds) by using the electrospinning technique. The hybrid scaffolds were developed through HA addition to accelerate osteoblast cell growth. Characteristic examinations of the scaffolds were performed by micrometer, SEM, contact angle measurement system, ATR-FTIR, tensile machine and swelling experiments. The thickness of all electrospun scaffolds was determined in the range of 0.010 +/- 0.001-0.012 +/- 0.002 mm. In order to optimize electrospinning processes, suitable bead-free and uniform scaffolds were selected by using SEM images. Blending of PCL with chitosan resulted in better hydrophilicity for the PCL/chitosan scaffolds. The characteristic peaks of PCL and chitosan in the blend and layer by layer nanofibers were observed. The PCL/chitosan/PCL layer by layer structure had higher elastic modulus and tensile strength values than both individual PCL and chitosan structures. The layer by layer scaffolds exhibited the PBS absorption values of 184.2; 197.2% which were higher than those of PCL scaffolds but lower than those of PCL/chitosan blend scaffolds. SaOs-2 osteosarcoma cell culture studies showed that the highest ALP activities belonged to novel PCL/chitosan/PCL layer by layer scaffolds meaning better cell differentiation on the surfaces. (C) 2011 Elsevier B.V. All rights reserved.Turkish Academy of Science (TUBA) L'Oreal; L'OrealThe author is greatly thankful to Turkish Academy of Science (TUBA) & L'Oreal for honoring this study with the award "Young Women in Science" in Materials Science in 2009. Her special thanks also go to L'Oreal for the precious financial support. The author also appreciates the invaluable contribution of AWAC (Academic Writing Advisory Center) to this study in linguistic terms
Turkish truffles I: 18 new records for Turkey
No full textWOS: 000352486200014We report the first records of 18 truffle species in Turkey. Three belong to the Ascomycota: Elaphomyces leucocarpus, E. muricatus, and Genea sphaerica; and 15 to the Basidiomycota: Alpova corsicus, Gautieria otthii, G. retirugosa, G. trabutii, Hymenogaster citrinus, H. hessei, H. luteus, H. lycoperdineus, Hysterangium clathroides, H. epiroticum, H. fragile, H. nephriticum, Leucogaster tozzianus, Octaviania asterosperma, and Protoglossum aromaticum. We also report new localities within Turkey for Picoa juniperi, P. lefebvrei, Geopora cooperi, Terfezia arenaria, T. claveryi, Tuber aestivum, and T. nitidum in the Ascomycota; and Leucogaster nudus, Hymenogaster thwaitesii, H. vulgaris, and Melanogaster broomeanus in the Basidiomycota.Scientific and Technological Research Council of Turkey projectTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [T-BAG-111T530, BIDEB-2221]The first author received funding from the Scientific and Technological Research Council of Turkey project number T-BAG-111T530 and BIDEB-2221. We appreciate the help from Abdulkadir Simsek, Ahmet Oksuzoglu, Cemhan Bucak, Coskun Bilgi, Duran Celik, Ekrem Toprak, Esra Er, Fatih Kaya, Gulsum Turkoglu, Idris Sener, Kadir Bazlica, Kadir Ceryan, Mehmet Halil Solak, Mehmet Metin, Mehmet Yucel, Murat Kilic, Mustafa Demir, Mustafa Turuncoglu, Niyazi Ulucoban, Okan Kursun, Osman Coban, Serkan Sevinc, Seyit Ahmet Akay, Tolga Keser, Ugur Demirbilek, Veysel Kodalak, and Yavuzalp Turkoglu in the collection of some of the specimens
Transforaminal Epidural Steroid Injection in the Treatment of_x000D_ Pain in Foraminal and Paramedian Lumbar Disc Herniations
No full textAIM: To compare the effect of fluoroscopically guided transforaminal epidural steroid injections on radicular pain in foraminal andparamedian lumbar disc herniations.MATERIAL and METHODS: This study included patients who did not benefit from previous medical treatments or are not suitablefor surgery. Transforaminal epidural steroid injections for the treatment of foraminal and paramedian lumbar disc herniationwere performed in 370 and 1262 patients, respectively. Every group’s preprocedural visual analogue scale (VAS) and 12-weekpostprocedural VAS scores were recorded, and statistical analysis was performed. The complications noted were also recorded.RESULTS: The preprocedural and postprocedural mean VAS scores for radicular pain in foraminal disc herniation were 67.11 ± 4.28and 34.78 ± 3.64, respectively. However, the preprocedural and postprocedural mean VAS scores in paramedian disc herniationwere 62.16 ± 6.65 and 19.07 ± 4.50, respectively. Statistical analysis of the varying preprocedural and postprocedural VAS scoresshowed that transforaminal epidural steroid injections were more effective for paramedian disc herniation than for foraminal discherniation (p<0.05).CONCLUSION: Transforaminal epidural steroid injections were more effective for paramedian lumbar disc herniation than forforaminal disc herniation, 12 weeks after the procedure
Luminescence of a Novel Near-UV Emitting Phosphor BaB8O13:Pb2+
No full textBa1-x Pb (x) B8O13 (0.005 a parts per thousand currency signaEuro parts per thousand x a parts per thousand currency signaEuro parts per thousand 0.0175) phosphors were synthesized by a conventional solid-state reaction using BaCO3 (99.99%), H3BO3 (99.80%), and PbO (99.99%) as starting materials. X-ray powder diffraction (XRD) analysis confirmed the formation of BaB8O13. Measurement of the photoluminescence (PL) excitation spectrum of BaB8O13:Pb2+ shows this phosphor can be efficiently excited by ultraviolet (UV) light from 200 to 280 nm and presents a dominant luminescence band centered at 360 nm. The effects of the doped-Pb2+ concentration in BaB8O13:Pb2+ on the PL were investigated in detail. The results showed that the relative PL intensity increased with increase in Pb2+-concentration reaching until 0.01 mol, where the intensity maximum was reached, and then it decreased due to concentration quenching. The thermoluminescence (TL) properties of BaB8O13 samples with different concentration of Pb2+ were also investigated.Bartin University [BAP-2011-1-50]The authors thank Prof. Orhan Turkoglu (Erciyes University) for the XRD measurement. This study is supported by Bartin University (BAP-2011-1-50 Project)
Synthesis and characterization of gamma-Bi2O3 based solid electrolyte doped with Nb2O5
No full textgamma-phase bismuth oxide is a well known high oxygen ion conductor and can be used as an electrolyte for intermediate temperature solid oxide fuel cells (IT-SOFCs). This study aims to determine new phases of Bi2O3-Nb2O5 binary system and the temperature dependence of the electrical transport properties. The reaction products obtained in open air atmosphere were characterized by X-ray powder diffractions (XRD). The unit cell parameters were defined from the indexes of the powder diffraction patterns. The gamma-Bi2O3 crystal system were obtained by doping 0.01 < mole% Nb2O5 < 0.04 at 750 degrees C for 48 and 96 h. Thermal behaviour and thermal stability of the phases were investigated by thermal analysis techniques. Surface and grain properties of the related phases were determined by SEM analysis. The temperature dependence of the electrical properties of gamma-Bi2O3 solid solution was measured by four-point probe d.c. conductivity method. In the investigated system, the highest value of conductivity was observed for sigma(T)=0.016 ohm(-1) cm(-1) at 650 degrees C on 4 mole% Nb2O5 addition. The electrical conductivity curves of studied materials revealed regular increase with temperature in the form of the Arrhenius type conductivity behaviour.Scientific and Technical Research Council of Turkey (TUBITAK) [108T377]The authors would like to thank the Scientific and Technical Research Council of Turkey (TUBITAK) for financial help (Grant no. 108T377)
Dysprosium(III) hydroxide coprecipitation system for the separation and preconcentration of heavy metal contents of table salts and natural waters
No full textSynthesis and characterization of gamma-Bi2O3 based solid electrolyte doped with Nb2O5
No full textgamma-phase bismuth oxide is a well known high oxygen ion conductor and can be used as an electrolyte for intermediate temperature solid oxide fuel cells (IT-SOFCs). This study aims to determine new phases of Bi2O3-Nb2O5 binary system and the temperature dependence of the electrical transport properties. The reaction products obtained in open air atmosphere were characterized by X-ray powder diffractions (XRD). The unit cell parameters were defined from the indexes of the powder diffraction patterns. The gamma-Bi2O3 crystal system were obtained by doping 0.01 < mole% Nb2O5 < 0.04 at 750 degrees C for 48 and 96 h. Thermal behaviour and thermal stability of the phases were investigated by thermal analysis techniques. Surface and grain properties of the related phases were determined by SEM analysis. The temperature dependence of the electrical properties of gamma-Bi2O3 solid solution was measured by four-point probe d.c. conductivity method. In the investigated system, the highest value of conductivity was observed for sigma(T)=0.016 ohm(-1) cm(-1) at 650 degrees C on 4 mole% Nb2O5 addition. The electrical conductivity curves of studied materials revealed regular increase with temperature in the form of the Arrhenius type conductivity behaviour
Synthesis and properties of beta type Bi(III)(2-2x)Dy(II)(2x)O3-x square(x) solid solution
No full textIn the present work, tetragonal beta type Bi( III)(2-2x) Dy( II)(2x)O3- x square x (square: empty oxygen site) solid solutions have been synthesized in the ranges 0.06 <= x <= 0.08 at 750 degrees C and 0.05 <= x <= 0.09 at 800 degrees C by doping small amounts of Dy2O3 into monoclinic alpha-Bi2O3. X-ray powder diffraction (XRD) has been used for characterisation of the doped Dy2O3 powders as well as for calculation of the unit cell parameters. The polymorphic phase transitions, crystallographic properties, particle sizes, the scanning electron microscope (SEM) microprobe analysis and Dy2O3 content dependence of the lattice parameters of the observed beta-phase has been reported. The obtained solid solutions had nonstoichiometric character and nonstoichiometry increases with the increasing amount of Dy2O3 addition. The experimental results suggested that oxygen vacancies are present in the crystal structure of Dy2O3 doped type solid solutions. (C) 2005 Springer Science + Business Media, Inc
