404 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
SOME FIXED POINT THEOREMS OF (F, phi)-FUZZY CONTRACTIONS IN FUZZY METRIC SPACES
No full textThe main concern of this study is to introduce the notion of fuzzy phi -best proximity point and establish the existence and uniqueness of fuzzy phi-best proximity point for mappings satisfying (F, phi)-fuzzy contraction and (F, phi)-weak fuzzy contraction in the context of complete fuzzy metric spaces. Also we give its fuzzy best proximity results
Fixed-Point Theorems Using α-Series in F-Metric Spaces
No full textFixed-point theory, which has been developing since 1922, is widely used. Various contraction principles have been defined in the literature. In this work, we define rational-type contraction and weak Choudhury type contraction using α-series in F-metric spaces and prove common fixed-point theorems for sequences of self-mappings. This method is based on the convergence series of coefficients. Our results are the generalized version of the results in the literature. Finally, we apply our main results to solve an integral equation and a differential equation
SOME FIXED POINT THEOREMS OF (F, phi)-FUZZY CONTRACTIONS IN FUZZY METRIC SPACES
No full textWOS: 000416773700002The main concern of this study is to introduce the notion of fuzzy phi -best proximity point and establish the existence and uniqueness of fuzzy phi-best proximity point for mappings satisfying (F, phi)-fuzzy contraction and (F, phi)-weak fuzzy contraction in the context of complete fuzzy metric spaces. Also we give its fuzzy best proximity results
Some fixed point results in complete generalized metric spaces
No full textThe Banach contraction principle is the most important result. This principle has many applications and some authors was interested in this principle in various metric spaces as Brianciari.
The author initiated the notion of the generalized metric space as a generalization of a metric space by replacing the triangle inequality by a more general inequality, for all pairwise distinct points of . As such, any metric space is a generalized metric space but the converse is not true. He proved the Banach fixed point theorem in such a space. Some authors proved different types of fixed point theorems by extending the Banach's result. Wardowski introduced a new contraction, which generalizes the Banach contraction. He using a mapping introduced a new type of contraction called -contraction and proved a new fixed point theorem concerning -contraction. In this paper, we have dealt with -contraction and -weak contraction in complete generalized metric spaces. We prove some results for -contraction and -weak contraction and we show that the existence and uniqueness of fixed point for satisfying -contraction and -weak contraction in complete generalized metric spaces. Some examples are supplied in order to support the useability of our results. The obtained result is an extension and a generalization of many existing results in the literature
Two fixed point results for multivalued F-contractions on M-metric spaces
No full textAltun, Ishak/0000-0002-7967-0554In this article, by considering Feng-Liu's technique, we present new fixed point results for multivalued mappings which are regarding to F-contraction on M-complete M-metric space. Then, we provide some nontrivial examples showing that our main results proper extension of some earlier results in the literature
On pre-service science teachers' preexisting knowledge levels about basic astronomy concepts
No full textA curriculum to train teacher candidates is a very important factor in developing teacher candidates' conceptual understanding of scientific concepts. Teacher candidates have a dramatic impact on students' ability to understand and construct new knowledge of the concepts. The purpose of this study was to determine the preconceptions and misconceptions of teacher candidates about basic astronomy concepts. This was measured by administrating the validated diagnostic questions from the latest version of the Astronomy Diagnostic Test 2.0 - 113 teacher candidates in the School of Education in Amasya University, Turkey. The findings indicated that teacher candidates held a series of misconceptions on several basic astronomy concepts. Common misconceptions were identified and a constructivist-inquiry approach to teaching basic astronomy concepts in the astronomy curriculum for pre-service teachers was proposed. © 2009 Academic Journals
A fixed point theorem for weakly compatible mappings satisfying a general contractive condition of operator type
No full textAltun, Ishak/0000-0002-7967-0554In this paper, we prove a fixed point theorem for weakly compatible mappings satisfying a general contractive condition of operator type. In short, we are going to study mappings A, B,S,T : X -> X for which there exists a right continuous function psi : R+-> R+, psi(0) = 0 and psi(s) 0 such that for each x, y is an element of X one has O(f; d(S-x,T-y))<= psi(O(f; M(x,y))), where O(f;.) and f are defined in the first section. Also in the first section, we give some examples for O(f;). The second section contains the main result. In the last section, we give some corollaries and remarks
A FIXED POINT THEOREM FOR WEAKLY COMPATIBLE MAPPINGS SATISFYING A GENERAL CONTRACTIVE CONDITION OF OPERATOR TYPE
No full textIn this paper, we prove a fixed point theorem for weakly compatible mappings satisfying a general contractive condition of operator type. In short, we are going to study mappings A, B,S,T : X -> X for which there exists a right continuous function psi : R+-> R+, psi(0) = 0 and psi(s) 0 such that for each x, y is an element of X one has O(f; d(S-x,T-y))<= psi(O(f; M(x,y))), where O(f;.) and f are defined in the first section. Also in the first section, we give some examples for O(f;). The second section contains the main result. In the last section, we give some corollaries and remarks
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