68 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
Precision oncology: Artificial intelligence, circulating cell‐free DNA, and the minimally invasive detection of pancreatic cancer—A pilot study
No full textAbstract Background Pancreatic cancer (PC) is among the most lethal cancers. The lack of effective tools for early detection results in late tumor detection and, consequently, high mortality rate. Precision oncology aims to develop targeted individual treatments based on advanced computational approaches of omics data. Biomarkers, such as global alteration of cytosine (CpG) methylation, can be pivotal for these objectives. In this study, we performed DNA methylation profiling of pancreatic cancer patients using circulating cell‐free DNA (cfDNA) and artificial intelligence (AI) including Deep Learning (DL) for minimally invasive detection to elucidate the epigenetic pathogenesis of PC. Methods The Illumina Infinium HD Assay was used for genome‐wide DNA methylation profiling of cfDNA in treatment‐naïve patients. Six AI algorithms were used to determine PC detection accuracy based on cytosine (CpG) methylation markers. Additional strategies for minimizing overfitting were employed. The molecular pathogenesis was interrogated using enrichment analysis. Results In total, we identified 4556 significantly differentially methylated CpGs (q‐value < 0.05; Bonferroni correction) in PC versus controls. Highly accurate PC detection was achieved with all 6 AI platforms (Area under the receiver operator characteristics curve [0.90–1.00]). For example, DL achieved AUC (95% CI): 1.00 (0.95–1.00), with a sensitivity and specificity of 100%. A separate modeling approach based on logistic regression‐based yielded an AUC (95% CI) 1.0 (1.0–1.0) with a sensitivity and specificity of 100% for PC detection. The top four biological pathways that were epigenetically altered in PC and are known to be linked with cancer are discussed. Conclusion Using a minimally invasive approach, AI, and epigenetic analysis of circulating cfDNA, high predictive accuracy for PC was achieved. From a clinical perspective, our findings suggest that that early detection leading to improved overall survival may be achievable in the future
New records of some Ascomycete truffle fungi from Turkey
No full textWOS: 000329918200020We report the first records of 6 Ascomycete truffle taxa in Turkey: Genea verrucosa Vittad., Genea klotzschii Berk. & Broome, Stephensia bombycina (Vittad.) Tul. & C. Tul., Terfezia olbiensis Tul. & C. Tul., Tuber excavatum Vittad., and Tuber rufum Pico. We also report new localities within Turkey for Picoa juniperi Vittad., Terfezia leptoderma Tul. & C. Tul., Choiromyces meandriformis Vittad., Tuber brumale Vittad., Tuber nitidum Vittad., and Tuber mesentericum Vittad.Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [T-BAG-111T530]The first author received funding from the Scientific and Technological Research Council of Turkey (project number T-BAG-111T530). We appreciate the help of Niyazi Ulucoban, Serkan Sevinc, Mustafa Turuncoglu, Nihat Guldas, Fatih Kaya, Osman Coban, and Mehmet Cirit in the collection of some of the specimens. We also appreciate the helpful commentary of Dr James M Trappe
Recognition of DDoS attacks on SD-VANET based on combination of hyperparameter optimization and feature selection
No full textThe aim of Vehicular Ad Hoc Networks (VANETs) is to provide drivers and passengers with various applications and services for comfortable transportation by supporting traffic efficiency and safety. However, the traditional VANETs face various technical challenges in meeting the basic requirements of intelligent transportation systems such as scalability, flexibility and management due to the ever-increasing number of intelligent vehicles. With its flexible, programmable, scalable network structure, Software Defined Networks (SDNs) are candidates for providing solutions to the problems experienced. The architecture, which was created by adapting the SDN paradigm to the traditional VANET is simply called SD-VANET. This new architecture allows easy scaling of the network and flexible network management. Despite the advantages of SD-VANET architecture, it is also vulnerable to cyberattack threats such as Distributed Denial Of Service (DDoS). In this study, different machine learning classifiers were used to detect DDoS attacks targeting SD-VANETs. First, a dataset containing features of normal network traffic and DDoS attack network traffic was obtained from an experimentally created SD-VANET topology. Then the Minimum Redundancy Maximum Relevance (MRMR) feature selection algorithm was used to select the most distinctive features of the dataset. Machine learning classifiers were trained and tested with both original and feature selection applied datasets. Moreover, in the learning phase, hyperparameter optimization for the classifiers was applied using the Bayesian optimization method. According to the experimental results, the highest accuracy score obtained was 99.35% with MRMR feature selection and Bayesian optimization-based decision tree classifier. The results demonstrate that the MRMR feature selection and Bayesian optimizationbased classifier approach have been successful for the detection of DDoS attacks on SD-VANETs
Assessing Rock Mass Permeability Using Discontinuity Properties
No full textISRM European Rock Mechanics Symposium (EUROCK) - JUN 20-22, 2017 - Ostrava, CZECH REPUBLICWOS: 000416996000082Field measurement of rock mass permeability is essential that numerous factors influence its directional magnitude. Lugeon test is a popularly conducted field instrument in order to measure hydraulic conductivity of a rock mass. Discontinuity orientation, spacing and discontinuity surface quality, infill presence and type play essential role in permeability of the rock mass in addition to rock material itself. Geological Strength Index (GSI) is a parameter used in Gen. Hoek-Brown failure criterion and supporting empirical equations in order to estimate rock mass strength and deformability parameters. Frequently used Rock Quality Designation (RQD) and GSI and Lugeon values were combined in order to generate a relation among them. The proposed relationships are produced by interpretation of geotechnical core logging and Lugeon test results. (C) 2017 The Authors. Published by Elsevier Ltd.Int Soc Rock Mech, ASCR, Inst GeonPolyak Eynez Energy Mining A.S. and Fina EnergyThe author thanks to Polyak Eynez Energy Mining A.S. and Fina Energy and its personnel for supporting scientific research and providing necessary data for the study. The author presents his gratitudes to Geological Engineers of Polyak Eynez, Feridun Emre Yagimli, Turkoglu, Mehmet Kilic for providing extensive data on the geology of the area, preparation of geotechnical borehole logs and their additional care during hydraulic testing. Special thanks also go to the reviewers
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
Formwork Systems Selection Criteria for Building Construction Projects: A Critical Review of the Literature
No full textFormwork system (FWS) is one of the key components in reinforced concrete (RC) construction. Therefore, selection of the most appropriate FWS plays a critical role in the project success. Since the FWS selection is affected by several compromising and conflicting criteria, numerous studies have been carried out to identify the FWS selection criteria and/or have employed various multi-criteria decision-making (MCDM) methods since the early 1990s. However, there is no research that conducts a critical review of the previous studies addressing the FWS selection criteria in building construction projects. This study aims to fill this knowledge gap. For this purpose, a critical review of the relevant literature was carried out using an integrative approach and the findings were validated through face-to-face interviews with professionals specialized in formwork engineering. The findings of this study may provide practitioners with a useful guide that can assist them in selecting the most appropriate FWS.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Diminished ovarian reserve in patients with psoriasis
No full textObjective: Psoriasis is a multi-systemic chronic inflammatory skin disease. Previous data suggests that women with some chronic inflammatory diseases have diminished ovarian reserve. This study explores ovarian reserve in patients with psoriasis. Materials and methods: We prospectively analyzed 14 female patients with psoriasis and 35 healthy age and body mass index matched controls. An interview explored demographic characteristics, obstetrical history and menstrual characteristics. Psoriatic area severity index (PASI) in patients was assessed. Estrogen, follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid stimulating hormone and with gynecologic ultrasonography, ovarian volume and antral follicular count (AFC) were measured in both study and control groups. These values were analyzed with changes of the PASI in the patient group. Results: Patients with psoriasis had significantly higher levels of FSH and FSH/LH ratio than healthy controls (p = 0.039, p = 0.005 respectively). AFC of psoriasis patients were significantly lower than healthy controls (p = 0.002).There were no significant difference among other hormone levels and ovarian volumes (p > 0.05). The hormone levels, ovarian volume and AFC were not correlated with PASI of the patients. Conclusion: The results of the study suggest that patients with psoriasis may have diminished ovarian reserve. Keywords: Psoriasis, Ovarian reserve, Psoriatic area severity index, Antral follicular count, Follicle-stimulating hormon
Alzheimer’s Precision Neurology: Epigenetics of Cytochrome P450 Genes in Circulating Cell-Free DNA for Disease Prediction and Mechanism
No full textPrecision neurology combines high-throughput technologies and statistical modeling to identify novel disease pathways and predictive biomarkers in Alzheimer’s disease (AD). Brain cytochrome P450 (CYP) genes are major regulators of cholesterol, sex hormone, and xenobiotic metabolism, and they could play important roles in neurodegenerative disorders. Increasing evidence suggests that epigenetic factors contribute to AD development. We evaluated cytosine (‘CpG’)-based DNA methylation changes in AD using circulating cell-free DNA (cfDNA), to which neuronal cells are known to contribute. We investigated CYP-based mechanisms for AD pathogenesis and epigenetic biomarkers for disease detection. We performed a case–control study using 25 patients with AD and 23 cognitively healthy controls using the cfDNA of CYP genes. We performed a logistic regression analysis using the MetaboAnalyst software computer program and a molecular pathway analysis based on epigenetically altered CYP genes using the Cytoscape program. We identified 130 significantly (false discovery rate correction q-value < 0.05) differentially methylated CpG sites within the CYP genes. The top two differentially methylated genes identified were CYP51A1 and CYP2S1. The significant molecular pathways that were perturbed in AD cfDNA were (i) androgen and estrogen biosynthesis and metabolism, (ii) C21 steroid hormone biosynthesis and metabolism, and (iii) arachidonic acid metabolism. Existing evidence suggests a potential role of each of these biochemical pathways in AD pathogenesis. Next, we randomly divided the study group into discovery and validation sub-sets, each consisting of patients with AD and control patients. Regression models for AD prediction based on CYP CpG methylation markers were developed in the discovery or training group and tested in the independent validation group. The CYP biomarkers achieved a high predictive accuracy. After a 10-fold cross-validation, the combination of cg17852385/cg23101118 + cg14355428/cg22536554 achieved an AUC (95% CI) of 0.928 (0.787~1.00), with 100% sensitivity and 92.3% specificity for AD detection in the discovery group. The performance remained high in the independent validation or test group, achieving an AUC (95% CI) of 0.942 (0.905~0.979) with a 90% sensitivity and specificity. Our findings suggest that the epigenetic modification of CYP genes may play an important role in AD pathogenesis and that circulating CYP-based cfDNA biomarkers have the potential to accurately and non-invasively detect AD
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