Molecular Typing and Antimicrobial Susceptibility of Staphylococcus aureus Strains Isolated from Raw Milk, Cheese, Minced Meat, and Chicken Meat Samples

Hayriye Yesim Can,Mehmet Elmalı,Alper Karagoz 한국축산식품학회 2017 한국축산식품학회지 Vol.37 No.2

The objectives of this study were: i) to detect the presence of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in raw milk, cheese, beef minced meat, and chicken meat samples; ii) to evaluate the antimicrobial susceptibility of the isolates; and iii) to determine clonal relation among the isolates by using pulsed-field gel electrophoresis (PFGE) method. Therefore, a total of 160 food samples were randomly collected between August 2014 and May 2015 in Hatay province, located in the southern Turkey. Twenty (12.5%) of the samples were found to be contaminated with S. aureus. A total of 40 isolates from the 20 positive samples were confirmed to be S. aureus by multiplex PCR based on 16S rRNA and nuc gene. The mec A gene was not detected in any of the S. aureus strains. In the present study, 39 out of 40 (97.5%) isolates were found to be resistant to one or more antibiotics. All of isolates were susceptible to gentamicin, oxacillin, and vancomycin. The highest resistance rate was detected in penicillin (95%) and ampicillin (92.5%), followed by tetracycline (30%), erythromycin (20%), ciprofloxacin (12.5%). Nine major patterns were determined by PFGE. In 6 of these patterns, thirty-six strains (90%) had identical PFGE profiles.

Korean College Students` Reflexive Positions Toward Extensive Reading and Follow-up Activities

( Hayriye Kayi Aydar ) 21세기영어영문학회 2012 영어영문학21 Vol.25 No.1

Extensive reading activities are believed to be an effective way of increasing literacy and language development. Although previous work focused on the relation between extensive reading and overall linguistic competence and learner attitudes, the perspectives of language learners toward the post activities of extensive reading have not been adequately addressed. The study reported in this article was conducted to illuminate how English major and non English major students at a university in South Korea positioned themselves with regards to the follow-up extensive reading activities. Through a recursive analysis of interview data, survey, field notes, and student journal entries, the findings demonstrated that although a majority of students positioned themselves as tolerant and competent when they engaged in extensive reading activities, they positioned themselves as less capable in the required post-reading tasks. In light of the findings, implications for extensive reading activities and roles of teachers are discussed.

Effect of Laser Welding on In-Vitro Bioactivity Properties of Ti6Al4V Joints

Hayriye Ertek Emre,Şennur Arslan 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.4

In this study, the Ti6AI4V alloy, which is used as an implant material in the medical field, was joined with the laser weldingmethod at different welding speeds. The bioactivity features of the Ti6AI4V alloy and its samples joined at different weldingspeeds were determined by immersing in a simulated body fluid (SBF) for 1, 7, 14, 21 and 28 days. The hydroxyapatite (HA)formation on the surfaces of the samples was determined by calculating the weight gain. The weight loss was calculated byremoving the HA from the surface after bioactivity testing. The corrosion rates of the samples were also determined accordingto the weight loss. In addition, the characterization of the HA formed on the surfaces of the samples was performed. Asa result of the investigations, it was determined that the increase in laser welding speed, and therefore the decrease in heatinput, positively affected the bioactivity and biocorrosion features of the Ti6Al4V laser welded joints. It was determinedthat the particle sizes of the HAs of the laser weldments increased with lower heat inputs. It was also observed that theamount of HA nucleated on the laser-welded samples increased in accordance with the increase in the laser welding speed. The laser welded samples that were welded at higher welding speeds and therefore at lower heat inputs, exhibited betterbiocorrosion behaviors.

A New Charge Analysis Derived From the Results of Semi-Emprical Mo-Lcao Calculation

Yilmaz, Hayriye,Ceyhan, Emre Cahit,Guzel, Yahya Korean Chemical Society 2012 대한화학회지 Vol.56 No.2

In this study we present a new approach for computing the partial atomic charge derived from the wavefunctions of molecules. This charge, which we call the "y_charge", was calculated by taking into account the energy level and orbital populations in each molecular orbital (MO). The charge calculations were performed in the software, which was developed by us, developed using the C# programming language. Partial atomic charges cannot be calculated directly from quantum mechanics. According to a partitioning function, the electron density of constituent molecular atoms depends on the electrostatic attraction field of the nucleus. Taking into account the Boltzmann population of each MO as a function of its energy and temperature we obtain a formula of partial charges.

4D-QSAR Study of p56^Ick Protein Tyrosine Kinase Inhibitory Activity of Flavonoid Derivatives Using MCET Method

Yilmaz, Hayriye,Guzel, Yahya,Onal, Zulbiye,Altiparmak, Gokce,Kocakaya, Safak Ozhan Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.12

A four dimensional quantitative structure activity relationship analysis was applied to a series of 50 flavonoid inhibitors of $p56^{lck}$ protein tyrosine kinase by the molecular comparative electron topological method. It was found that the -log (IC50) values of the compounds were highly dependent on the topology, size and electrostatic character of the substituents at seven positions of the flavonoid scaffold in this study. Depending on the negative or positive charge of the groups correctly embedded in these substituents, three-dimensional bio-structure to increase or decrease -log (IC50) values in the training set of 39 compounds was predicted. The test set of 11 compounds was used to evaluate the predictivity of the model. To generate 4D-QSAR model, the defined function groups and pharmacophore used as topological descriptors in the calculation of activity were of sufficient statistical quality ($R^2$ = 0.72 and $Q^2$ = 0.69). Ligand docking approach by using Dock 6.0. These compounds include many flavonoid analogs, They were docked onto human families of p56lck PTKs retrieved from the Protein Data Bank, 1lkl.pdb.

Spectra of Interacting Electrons in a Quantum Dot: Quasi-Exact Solution

Eser Olgar,Hayriye Tutunculer,Ramazan Koc 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.1

We present a procedure to solve the Schrodinger equation of two interacting electrons in a quantum dot in the presence of an external magnetic field within the context of quasi-exactly-solvable spectral problems. We show that the symmetries of the Hamiltonian can be recovered for specific values of the magnetic field, which leads to an exact determination of the eigenvalues and eigenfunctions. We show that the problem possesses a hidden sl2ကalgebraic structure.

A robust numerical technique for solving non-linear Volterra integro-differential equations with boundary layer

Firat Cakir,Musa Cakir,Hayriye Guckir Cakir 대한수학회 2022 대한수학회논문집 Vol.37 No.3

In this paper, we study a first-order non-linear singularly perturbed Volterra integro-differential equation (SPVIDE). We discretize the problem by a uniform difference scheme on a Bakhvalov-Shishkin mesh. The scheme is constructed by the method of integral identities with exponential basis functions and integral terms are handled with interpolating quadrature rules with remainder terms. An effective quasi-linearization technique is employed for the algorithm. We establish the error estimates and demonstrate that the scheme on Bakhvalov-Shishkin mesh is $O(N^{-1})$ uniformly convergent, where $N$ is the mesh parameter. The numerical results on a couple of examples are also provided to confirm the theoretical analysis.

An ESL Teacher's Perspective on Recasts : A Qualitative Exploration of "When" and "How"?

Ji-Hyun Byun,Hayriye Kayi-Aydar 한국영어어문교육학회 2010 영어어문교육 Vol.16 No.4

Recasts, which are defined as implicit types of corrective feedback, have been the focus of numerous SLA researchers for more than a decade. A range of classroom-based observational and experimental research studies have explored how and when language teachers provide recasts to learners' ill-formed utterances and aimed to understand the role of recasts in language acquisition or learning. On the basis of previous studies on recasts, our study investigated when an ESL teacher provided recasts and how recasts were provided in his class. The research questions were as follows: (1) When does an ESL teacher provide recasts? (2) How does the teacher provide recasts? The data came from observations of one ESL classroom as well as consecutive-semi structured interviews with the teacher. The data analysis included transcriptions of teacher-student interactions in the target setting and categories of recasts according to the linguistic phenomena, which prompted recasting. Based on the findings, practical suggestions for ESL teachers were provided.

Effects of propofol, desflurane, and sevoflurane on respiratory functions following endoscopic endonasal transsphenoidal pituitary surgery: a prospective randomized study

Abdulvahap Oguz,Eren Fatma Akcil,Yusuf Tunali,Hayriye Vehid,Ozlem Korkmaz Dilmen 대한마취통증의학회 2019 Korean Journal of Anesthesiology Vol.72 No.6

Background: General anesthesia with intravenous or inhalation anesthetics reduces respiratory functions. We investigated the effects of propofol, desflurane, and sevoflurane on postoperative respiratory function tests. Methods: This single-center randomized controlled study was performed in a university hospital from October 2015 to February 2017. Ninety patients scheduled for endoscopic endonasal transsphenoidal pituitary surgery were randomly categorized into either of these three groups: propofol (n = 30, the Group TIVA), desflurane (n = 30, the Group D) or sevoflurane (n = 30, the Group S). We analyzed the patients before, after, and 24 h following surgery, to identify the following parameters: forced expiratory volume in 1 second (FEV1) %, forced vital capacity (FVC) %, FEV1/FVC, and arterial blood gases (ABG). Furthermore, we also recorded the intraoperative dynamic lung compliance and airway resistance values. Results: We did not find any significant differences in FEV1 values (primary outcome) among the groups (P = 0.336). There was a remarkable reduction in the FEV1 and FVC values in all groups postoperatively relative to the baseline (P < 0.001). The FVC, FEV1/FVC, ABG analysis, compliance, and airway resistance were similar among the groups. Intraoperative dynamic compliance values were lower at the 1st and 2nd hours than those immediately after intubation (P < 0.001). Conclusions: We demonstrated that propofol, desflurane, and sevoflurane reduced FEV1 and FVC values postoperatively, without any significant differences among the drugs.

An ESL Teacher's Perspective on Recasts: A Qualitative Exploration of "When" and "How"?

Byun, Ji-Hyun,Kayi-Aydar, Hayriye The English Teachers Association in Korea 2010 영어어문교육 Vol.16 No.4

Recasts, which are defined as implicit types of corrective feedback, have been the focus of numerous SLA researchers for more than a decade. A range of classroom-based observational and experimental research studies have explored how and when language teachers provide recasts to learners' ill-formed utterances and aimed to understand the role of recasts in language acquisition or learning. On the basis of previous studies on recasts, our study investigated when an ESL teacher provided recasts and how recasts were provided in his class. The research questions were as follows: (1) When does an ESL teacher provide recasts? (2) How does the teacher provide recasts? The data came from observations of one ESL classroom as well as consecutive-semi structured interviews with the teacher. The data analysis included transcriptions of teacher-student interactions in the target setting and categories of recasts according to the linguistic phenomena, which prompted recasting. Based on the findings, practical suggestions for ESL teachers were provided. [156 words].