Peel strength of denture liner to PMMA and polyamide: laser versus air-abrasion

Korkmaz, Fatih Mehmet,Bagis, Bora,Ozcan, Mutlu,Durkan, Rukiye,Turgut, Sedanur,Ates, Sabit Melih The Korean Academy of Prosthodonitics 2013 The Journal of Advanced Prosthodontics Vol.5 No.3

PURPOSE. This study investigated the effect of laser parameters and air-abrasion on the peel strength of silicon-based soft denture liner to different denture resins. MATERIALS AND METHODS. Specimens (N=180) were prepared out of three different denture base resins (Rodex, cross-linked denture base acrylic resin; Paladent, heat-cured acrylic resin; Deflex, Polyamide resin) ($75mm{\times}25mm{\times}3mm$). A silicon-based soft denture liner (Molloplast B) was applied to the denture resins after the following conditioning methods: a) Air-abrasion ($50{\mu}m$), b) Er,Cr:YSGG laser (Waterlase MD Turbo, Biolase Technology) at 2 W-20 Hz, c) Er,Cr:YSGG laser at 2 W-30 Hz, d) Er,Cr:YSGG laser at 3 W-20 Hz, e) Er,Cr:YSGG laser at 3 W-30 Hz. Non-conditioned group acted as the control group. Peel test was performed in a universal testing machine. Failure modes were evaluated visually. Data were analyzed using two-way ANOVA and Tukey's test (${\alpha}$=.05). RESULTS. Denture liner tested showed increased peel strength after laser treatment with different parameters ($3.9{\pm}0.4-5.58{\pm}0.6$ MPa) compared to the control ($3.64{\pm}0.5-4.58{\pm}0.5$ MPa) and air-abraded groups ($3.1{\pm}0.6-4.46{\pm}0.3$ MPa), but the results were not statistically significant except for Paladent, with the pretreatment of Er,Cr:YSGG laser at 3 W-20 Hz. Polyamide resin after air-abrasion showed significantly lower peel strength than those of other groups ($3.1{\pm}0.6$ MPa). CONCLUSION. Heat-cured acrylic resin, PMMA, may benefit from Er,Cr:YSGG laser treatment at 3 W-20 Hz irradiation. Air-abrasion of polyamide resins should be avoided not to impair their peel bond strengths to silicon-based soft denture liners.

Hypoparathyroidism in children and adolescents

Korkmaz Hüseyin Anıl,Ozkan Behzat 대한소아내분비학회 2023 Annals of Pediatirc Endocrinology & Metabolism Vol.28 No.3

Hypoparathyroidism is characterized by insufficient parathyroid hormone (PTH) release from the parathyroid glands to maintain serum calcium level within normal limits and unresponsiveness of target tissues despite normal serum PTH level. Hypoparathyroidism is defined as low or inappropriately normal serum PTH level. In this narrative review, we discuss the etiology of hypoparathyroidism in children.

Reliability of Stool Antigen Tests: Investigation of the Diagnostic Value of a New Immunochromatographic Helicobacter pylori Approach in Dyspeptic Patients

Korkmaz, Huseyin,Findik, Duygu,Ugurluoglu, Ceyha,Terzi, Yuksel Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Background: A diagnosis of H. pylori infection can be made by invasive or non-invasive methods. Several noninvasive diagnostic tests based on the detection of H. pylori stool antigen (HpSA) have been developed. The Genx H. pylori stool antigen card test is a new rapid, non-invasive test that is based on monoclonal immunochromatographic assay. The aim of this study was to determine its sensitivity, specificity, and diagnostic accuracy for diagnosing H. pylori infection in adult patients. Materials and Methods: A total of 162 patients were included in the study. A gastric biopsy was collected for histopathology and rapid urease testing. Stool specimens for HpSA testing were also collected. Patients were considered H. pylori positive if two invasive tests (histological and rapid urease tests) were positive. Results: Using the reference test, 50.6% of the samples were positive for H. pylori infection. The Genx H. pylori antigen test was positive in 19.7% of patients. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the Genx H. pylori antigen test were 51.6%, 96.0%, 88.8%, 76.1%, and 79.0%, respectively. Conclusions: The Genx H. pylori stool antigen card test is a new non-invasive method that is fast and simple to perform but provides less reliable results.

THE INVESTIGATION OF BURNUP CHARACTERISTICS USING THE SERPENT MONTE CARLO CODE FOR A SODIUM COOLED FAST REACTOR

Korkmaz, Mehmet E.,Agar, Osman Korean Nuclear Society 2014 Nuclear Engineering and Technology Vol.46 No.3

In this research, we investigated the burnup characteristics and the conversion of fertile $^{232}Th$ into fissile $^{233}U$ in the core of a Sodium-Cooled Fast Reactor (SFR). The SFR fuel assemblies were designed for burning $^{232}Th$ fuel (fuel pin 1) and $^{233}U$ fuel (fuel pin 2) and include mixed minor actinide compositions. Monte Carlo simulations were performed using Serpent Code1.1.19 to compare with CRAM (Chebyshev Rational Approximation Method) and TTA (Transmutation Trajectory Analysis) method in the burnup calculation mode. The total heating power generated in the system was assumed to be 2000 MWth. During the reactor operation period of 600 days, the effective multiplication factor (keff) was between 0.964 and 0.954 and peaking factor is 1.88867.

The Epidemiological and Clinical Characteristics of 81 Children with COVID-19 in a Pandemic Hospital in Turkey: an Observational Cohort Study

Korkmaz Muhammet Furkan,Türe Esra,Dorum Bayram Ali,Kılıç Zeliha Banu 대한의학회 2020 Journal of Korean medical science Vol.35 No.25

Background: Coronavirus disease-2019 (COVID-19) pandemic has affected millions of people throughout the world since December 2019. However, there is a limited amount of data about pediatric patients infected with the disease agent, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: The epidemiological, laboratory, radiological, and treatment features of the pediatric patients who were positive for SARS-CoV-2 based on the reverse-transcription polymerase chain reaction (RT-PCR) test, were investigated retrospectively. Results: The median age of 81 children included in the study was 9.50 years (0–17.75 years). The most frequent symptoms at the time of admission were fever (58%), cough (52%), and fatigue or myalgia (19%). The abnormal laboratory findings in these cases were decreased lymphocytes (2.5%, n = 2), leucopenia (5%, n = 4), and increased lactate dehydrogenase (17.2%, n = 14), C-reactive protein (16%, n = 13), procalcitonin (3.7%, n = 3), and D-dimer (12.3%, n = 10). Three (4%) patients had consolidation in chest computed tomography, and three (4%) had ground-glass opacities. None of the patients needed intensive care except for the newborns. The median time to turn SARS-CoV-2 negative in the RT-PCR test was 5 (3–10) days. The median length of hospital stay was 5 (4–10) days. The time to turn SARS-CoV-2 negative in the RT-PCR test and the length of hospital stay were significantly longer for those aged five years or younger than others (P = 0.037, P = 0.01). Conclusion: Compared to adults, COVID-19 is milder and more distinctive in children. As a result, more conservative approaches might be preferred in children for the diagnostic, clinical, and even therapeutic applications.

Comparison of Safety Perception between Foreign and Local Workers in the Construction Industry in Republic of Korea

Korkmaz, Serdar,Park, Dal Jae Occupational Safety and Health Research Institute 2018 Safety and health at work Vol.9 No.1

Background: Since the Republic of Korea became a labor-force-importing country, the number of foreign workers has increased gradually, especially in the construction industry. The main objective of this study was to examine the differences in safety perception between domestic and foreign workers at Korean construction sites. Methods: A total of 891 Korean and foreign workers were surveyed: 140 foreign and 751 Korean workers. The general characteristics and 25 factors influencing safety perception were considered in the questionnaire. Regression and correlation analyses were conducted to examine the variables of workers' safety perception. Results: Differences of nationality (F = 7.379, p < 0.001) and workplace accidents were statistically significant for both domestic (F = 1.503, p < 0.05) and foreign workers (F = 7.868, p < 0.05). In contrast, age, education, and Korean language level were significant variables only for foreign workers. Correlation coefficients of $0.428^{**}$ for Korean and 0.148 for foreign workers between two items - namely, "management's commitment to safety" and "blaming staff when they make mistakes" - support the conclusion that foreign workers do not trust management's commitment to safety, while Korean workers have confidence in these commitments. Conclusion: Foreign workers' level of safety perception should rise to the same level as Korean workers, especially in terms of obeying safety rules, safety education performance, and safety beliefs. Therefore, an improvement plan for the Korean construction industry is suggested in order to have a better safety level at construction sites with foreign workers.

Radionuclide Therapy Videos on YouTube as An Educational Material: Has the COVID-19 Pandemic Changed the Quality, Usefulness, and Interaction Features

Ulku Korkmaz,Selin Soyluoglu,Ersan Arda 대한핵의학회 2023 핵의학 분자영상 Vol.57 No.4

Introduction Current treatment approach aims to achieve greater efficacy with fewer side effects, by targeted cancer therapyas much as possible. Radionuclide therapy is a modality that uses cancer theranostics and is increasingly applied for variouscancers as a targeted therapy. YouTube is a preferred tool for obtaining medical information from the internet. This study aimsto determine the content quality, level of interaction and usefulness as education material of radionuclide therapy YouTubevideos and to reveal the impact of the COVID-19 process on these parameters. Materials and Methods The keywords were searched on YouTube on August 25, 2018, and May 10, 2021. After removingduplicate and excluded videos, all remaining videos were scored and coded. Results Majority of the videos were useful educational material. Most of them were high quality. Popularity markers wereunrelated to quality level. After COVID, the power index of videos with high JAMA scores increased. The COVID-19 pandemicdid not have a negative effect on video features; the quality of the content increased even more after the pandemic. Conclusion Radionuclide therapy YouTube videos have high-quality content and provide useful education material. Thepopularity is independent of the content quality. During the pandemic, video quality and usefulness characteristics did notchange, while the visibility is increased. We consider YouTube to be an appropriate educational material for patients andhealthcare professionals to gain basic knowledge of radionuclide therapy. The Covıd-19 pandemic highlighted the power ofradionuclide therapy YouTube videos as an educational material.

Influence of various metal oxides on mechanical and physical properties of heat-cured polymethyl methacrylate denture base resins

Turan Korkmaz,Hai Albayrak,Ilser Turkyilmaz,Neset Volkan Asar 대한치과보철학회 2013 The Journal of Advanced Prosthodontics Vol.5 No.3

PURPOSE To evaluate the effect of various metal oxides on impact strength (IS), fracture toughness (FT), water sorption (WSP) and solubility (WSL) of heat-cured acrylic resin. MATERIALS AND METHODS Fifty acrylic resin specimens were fabricated for each test and divided into five groups. Group 1 was the control group and Group 2, 3, 4 and 5 (test groups) included a mixture of 1% TiO2 and 1% ZrO2, 2% Al2O3, 2% TiO2, and 2% ZrO2 by volume, respectively. Rectangular unnotched specimens (50 mm × 6.0 mm × 4.0 mm) were fabricated and droptower impact testing machine was used to determine IS. For FT, compact test specimens were fabricated and tests were done with a universal testing machine with a cross-head speed of 5 mm/min. For WSP and WSL, discshaped specimens were fabricated and tests were performed in accordance to ISO 1567. ANOVA and Kruskal-Wallis tests were used for statistical analyses. RESULTS IS and FT values were significantly higher and WSP and WSL values were significantly lower in test groups than in control group (P<.05). Group 5 had significantly higher IS and FT values and significantly lower WSP values than other groups (P<.05) and provided 40% and 30% increase in IS and FT, respectively, compared to control group. Significantly lower WSL values were detected for Group 2 and 5 (P<.05). CONCLUSION Modification of heat-cured acrylic resin with metal oxides, especially with ZrO2, may be useful in preventing denture fractures and undesirable physical changes resulting from oral fluids clinically.

A Curvature Property of Complex Contact Metric Structures

Belgin Korkmaz KYUNGPOOK UNIVERSITY 1998 Kyungpook mathematical journal Vol.38 No.1

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Comparison of three different risk-stratification models for predicting lymph node involvement in endometrioid endometrial cancer clinically confined to the uterus

Vakkas Korkmaz,Mehmet Mutlu Meydanli,Ibrahim Yalçın,Mustafa Erkan Sarı,Hanifi Sahin,Eda Kocaman,Ali Haberal,Polat Dursun,Tayfun Güngör,Ali Ayhan 대한부인종양학회 2017 Journal of Gynecologic Oncology Vol.28 No.6

Objective: To compare the clinical validity of the Gynecologic Oncology Group-99 (GOG-99), the Mayo-modified and the European Society for Medical Oncology (ESMO)-modified criteria for predicting lymph node (LN) involvement in women with endometrioid endometrial cancer (EC) clinically confined to the uterus. Methods: A total of 625 consecutive women who underwent comprehensive surgical staging for endometrioid EC clinically confined to the uterus were divided into low- and high-risk groups according to the GOG-99, the Mayo-modified, and the ESMO-modified criteria. Lymphovascular space invasion is the cornerstone of risk stratification according to the ESMO-modified criteria. These 3 risk stratification models were compared in terms of predicting LN positivity. Results: Systematic LN dissection was achieved in all patients included in the study. LN involvement was detected in 70 (11.2%) patients. LN involvement was correctly estimated in 51 of 70 LN-positive patients according to the GOG-99 criteria (positive likelihood ratio [LR+], 3.3; negative likelihood ratio [LR−], 0.4), 64 of 70 LN-positive patients according to the ESMO-modified criteria (LR+, 2.5; LR−, 0.13) and 69 of the 70 LN-positive patients according to the Mayo-modified criteria (LR+, 2.2; LR−, 0.03). The area under curve of the Mayo-modified, the GOG-99 and the ESMO-modified criteria was 0.763, 0.753, and 0.780, respectively. Conclusion: The ESMO-modified classification seems to be the risk-stratification model that most accurately predicts LN involvement in endometrioid EC clinically confined to the uterus. However, the Mayo-modified classification may be an alternative model to achieve a precise balance between the desire to prevent over-treatment and the ability to diagnose LN involvement.