Samsun, Turkey
Samsun, Turkey

Time filter

Source Type

Tepe C.,Ondokuzmayis University | Eminoglu I.,Ondokuzmayis University
2016 Medical Technologies National Conference, TIPTEKNO 2016 | Year: 2016

In this study, programmable current source (PCS) experimental set-up that measures the nerve conduction velocity is designed. Firstly, analog PCS is implemented with integrated circuit of 555. Then, microprocessor-based PCS is designed by improving existing analog design at hand. PCS can produce current signal with adjustable frequency and amplitude. An EMG amplifier circuit is designed to measure the EMG signal from thumb finger muscle stimulated by PCS device. EMG signal is then send to the computer with a serial communication port. Received EMG signals are plotted in MATLAB and some interpretations are given. © 2016 IEEE.

Celik N.,Cukurova University | Koc E.,Ondokuzmayis University
Fibres and Textiles in Eastern Europe | Year: 2010

In the two earlier papers, evaluations were presented on the characteristic parameters determining the behaviour of three industrially produced Wilton-type carpets with different pile materials (wool, acrylic and PP) after a prolonged heavy static loading, and an extended analysis was carried out covering the energy absorption, damping characteristics and hysteresis effect of pile materials on carpet behaviour during recovery. In this study, the same carpets were tested under dynamic loading in order to evaluate and observe the thickness loss and carpet behaviour under dynamic loads. The results are given and discussed in this paper.

Keles Z.P.,Ondokuzmayis University | Keles G.C.,Ondokuzmayis University | Avci B.,Ondokuzmayis University | Cetinkaya B.O.,Ondokuzmayis University | Emingil G.,Ege University
Journal of Periodontology | Year: 2014

Background: YKL-40, a new acute-phase protein, is shown to be elevated in inflammatory diseases, such as rheumatoid arthritis, type 2 diabetes mellitus, and coronary artery diseases. However, there is no data indicating a relationship between YKL-40 and periodontal disease. Interleukin- 6 (IL-6) is the major regulator of acute-phase protein synthesis and one of the most studied inflammatory markers in periodontal disease. The purpose of the present study is to evaluate YKL-40 and IL-6 levels in gingival crevicular fluid (GCF) and serum of patients with periodontal disease and healthy individuals. Methods: Periodontally healthy individuals (n = 15), patients with gingivitis (n = 15), and patients with severe chronic periodontitis (CP) (n = 15) without any systemic disease were included in the study. Clinical measurements were recorded; GCF and blood samples were obtained from each participant. GCF and serum YKL-40 and IL-6 levels were analyzed by enzyme-linked immunosorbent assay. Statistical analysis was performed by parametric and non-parametric tests. Results: Total amounts of YKL-40 and IL-6 in GCF as well as serum YKL-40 and IL-6 levels were significantly higher in patients with gingivitis and CP compared with healthy controls (P <0.01). YKL-40 levels in GCF and serum as well as serum IL-6 levels were significantly higher in patients with CP compared with patients with gingivitis (P <0.01). Conclusions: YKL-40 levels in GCF as well as serum YKL-40 and IL-6 levels increased from gingivitis to periodontitis. Within the limits of the present study, the YKL-40 molecule might be a potential novel inflammatory marker of periodontal disease.

Celenk C.,OndokuzMayis University | Celenk P.,Ondokuz Mayis University
American Journal of Roentgenology | Year: 2016

OBJECTIVE. Non-Hodgkin lymphomas (NHL) in the palate are very rare. We aimed to investigate the CT appearance of lymphoma in the palate to improve diagnostic quality and review the literature on NHL. MATERIALS AND METHODS. The study retrospectively included patients with histopathologically confirmed lymphoma who were treated at our hospital between 2008 and 2015. We examined CT features, including tumor location, appearance, margins, and involvement of the surrounding tissues. RESULTS. Records were available for eight cases of lymphoma over the study period. Of these, two were in the soft palate and six in the hard palate. Median age at presentation was 63 years. Seven of the eight were diffuse large B cell lymphoma and one was T cell lymphoma. Hard palate lymphoma on CT showed bone destruction and spread to the maxillary arch and maxillary sinuses, whereas soft palate lymphoma spread to the surrounding parapharyngeal area and did not show bone destruction. CONCLUSION. We describe CT findings of palate lymphoma, which are important for treatment planning. © American Roentgen Ray Society.

Alkim E.,Ondokuzmayis University | Gurbuz E.,Ondokuzmayis University | Kilic E.,Ondokuzmayis University
Neural Networks | Year: 2012

Automatic disease diagnosis systems have been used for many years. While these systems are constructed, the data used needs to be classified appropriately. For this purpose, a variety of methods have been proposed in the literature so far. As distinct from the ones in the literature, in this study, a general-purpose, fast and adaptive disease diagnosis system is developed. This newly proposed method is based on Learning Vector Quantization (LVQ) artificial neural networks which are powerful classification algorithms. In this study, the classification ability of LVQ networks is developed by embedding a reinforcement mechanism into the LVQ network in order to increase the success rate of the disease diagnosis method and reduce the decision time. The parameters of the reinforcement learning mechanism are updated in an adaptive way in the network. Thus, the loss of time due to incorrect selection of the parameters and decrement in the success rate are avoided. After the development process mentioned, the newly proposed classification technique is named "Adaptive LVQ with Reinforcement Mechanism (ALVQ-RM)". The method proposed handles data with missing values. To prove that this method did not offer a special solution for a particular disease, because of its adaptive structure, it is used both for diagnosis of breast cancer, and for diagnosis of thyroid disorders, and a correct diagnosis rate after replacing missing values using median method over 99.5% is acquired in average for both diseases. In addition, the success rate of determination of the parameters of the proposed "LVQ with Reinforcement Mechanism (LVQ-RM)" classifier, and how this determination affected the required number of iterations for acquiring that success rate are discussed with comparison to the other studies. © 2012 Elsevier Ltd.

The objectives of this study were to (1) determine the effects of imported commercial queen bees from different geographical origin subspecies on the morphological variation of native honeybee population of the Turkeli area; and (2) apply a model to identify and predict the use of commercial queens subspecies. Standard classification function, discriminant function, and constant coefficients for 41 morphological characteristics were determined for two geographic Turkish honeybee subspecies (Apis mellifera anatoliaca and A. m. caucasica) used intensively for commercial queen rearing. Then, the morphological characteristics of unknown worker bee samples from the Turkeli area - where commercial queen bee usage is common - were investigated. The model showed that the area was subject to genetic mixing because of commercial queen usage. The subspecies of 15 unknown test samples were predicted with 100% confidence, and the native bees from 25 of 30 samples from the Turkeli area were successfully predicted using the model developed. Using the model proved that there was a commercial queen bee introduction into the Turkeli area, mainly from the A. m. caucasica subspecies. © 2010 INRA/DIB-AGIB/EDP Sciences.

Cam M.A.,Ondokuzmayis University | Olfaz M.,Ondokuzmayis University | Soydan E.,Ondokuzmayis University
Asian Journal of Animal and Veterinary Advances | Year: 2010

This study was designed to estimate body weight from various body measurements in Karayaka sheep reared under rural extensive production systems. Animals were brought from different regions to slaughterhouse. Approximately 8 to 18 months-aged of Karayaka male (n = 67) and female (n = 55) sheep were used to investigate the relationships between bodyweights and body measurements such as Heart Girth (HG), Wither Height (WH), Chest Depth (CD), Chest Width (CW), Body Length (BL), Rump Height (RH), Thigh Circumference (TC) and Canon Circumference (CC). The R2 values between body weight and body measurements ranged from 0.130 to 0.773. The highest R2 values were found between body weight and chest depth (0.814, p<0.001) and between heart girth (0.792, p<0.001) for male and female, respectively. Correlation and regression analysis were applied to estimate the relationship among these traits. Therefore, it was concluded that body weight could be estimated by using a general equation from pooled data of Y =-25.8+2.10 CD; R2 = 0.773 regardless of gender. Also, there were higher correlations (R2 = 0.954) between body weight and both hot and cold carcass weight. © 2010 Academic Journals Inc.

Orkun M.O.,Ondokuzmayis University | Kuleyin A.,Ondokuzmayis University
Environmental Progress and Sustainable Energy | Year: 2012

The removal of chemical oxygen demand (COD) from landfill leachate by electro-coagulation (EC) using iron sacrificial anode has been investigated. The process performance is analyzed in terms of COD removal efficiency and the important cost-related parameters such as electrode and energy consumptions, as a function of initial pH, conductivity, current density, and operation time. The optimum COD removal (65.85%) was obtained with typical operating conditions: current density, 30 mA/cm 2; operation time, 180 min; conductivity, 16.4 ms/cm; and initial pH, 6.54. At these conditions, the electrode and energy consumptions during the electrolysis were determined as 0.418 kg COD/kg Al and 11.092 kWh/kg COD, respectively. In addition, the EC and Fenton processes are applied together referred to as the electro-Fenton process in the literature for the removal of COD from landfill leachate and effect of operation time and hydrogen peroxide concentration is examined. The process was very fast in the first 15 min, and then it slowed down till it was complete in 60 min. An optimum COD removal efficiency of 74.21% was obtained at 5000 ppm hydrogen peroxide dosage and 60 min. © 2010 American Institute of Chemical Engineers.

In this paper, we present techniques for ellipsoid fitting which are based on minimizing the sum of the squares of the geometric distances between the data and the ellipsoid. The literature often uses “orthogonal fitting” in place of “geometric fitting” or “best-fit”. For many different purposes, the best-fit ellipsoid fitting to a set of points is required. The problem of fitting ellipsoid is encountered frequently in theimage processing, face recognition, computer games, geodesy etc. Today, increasing GPS and satellite measurements precision will allow usto determine amore realistic Earth ellipsoid. Several studies have shown that the Earth, other planets, natural satellites, asteroids and comets can be modeled as triaxial ellipsoids Burša and Šima (1980), Iz et al (2011). Determining the reference ellipsoid for the Earth is an important ellipsoid fitting application, because all geodetic calculations are performed on the reference ellipsoid. Algebraic fitting methods solve the linear least squares (LS) problem, and are relatively straightforward and fast. Fitting orthogonal ellipsoid is a difficult issue. Usually, it is impossible to reach a solution with classic LS algorithms. Because they are often faced with the problem of convergence. Therefore, it is necessary to use special algorithms e.g. nonlinear least square algorithms. We propose to use geometric fitting as opposed to algebraic fitting. This is computationally more intensive, but it provides scope for placing visually apparent constraints on ellipsoid parameter estimation and is free from curvature bias Ray and Srivastava (2008). © 2015, Universidade Federal do Parana. All rights reserved.

Ucak Semirgin S.,Ondokuzmayis University
Nuclear Medicine Communications | Year: 2016

BACKGROUND: In routine noncontrast-enhanced PET/computed tomography (CT) studies, the female pelvis is one of the most challenging anatomical regions to interpret. In surgically treated patients, it may be more difficult to determine the accurate location of paravaginal hypermetabolic lesions. In this study, the aim was to investigate the contribution of additional PET/CT imaging using a vaginal catheter in patients with pelvic malignant disease. METHODS: Forty-seven patients with pelvic malignancies were enrolled in this study. Following routine whole-body fluorine-18 fluorodeoxyglucose (F-FDG) PET/CT scanning, an additional pelvic scan was obtained after placement of a plastic catheter in the vaginal lumen (v-catheter). All suspected foci in vaginal and paravaginal areas were evaluated for both studies. The contribution of additional v-catheter imaging was determined visually by five experienced interpreters. RESULTS: Pathological F-FDG uptake in various vaginal and/or paravaginal locations was detected in 24 of 47 patients after conventional PET/CT imaging. In 10 of these 24 patients, anatomic relations within the uptake area could not be confidently described and v-catheter imaging provided a significant contribution in all 10 cases. In seven of these 10 sites examined, pathological F-FDG uptake was safely ruled out and three sites were confirmed to be malignant. In total, the final interpretation in 13 of 24 patients (54%) was modified by additional v-catheter imaging. The contribution rate of catheter imaging was 89% in treated patients and 33% in untreated patients with vaginal and/or paravaginal lesions on initial scans. CONCLUSIONS: Additional v-catheter imaging of pelvis may be of diagnostic value in the accurate anatomical definition of hypermetabolic lesions in the vaginal/paravaginal area on noncontrasted PET/CT studies. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.

Loading OndokuzMayis University collaborators
Loading OndokuzMayis University collaborators