Effects of air-polishing powders on color stability of composite resins

OBJECTIVES: The purpose of this study was to investigate the effect of different air-polishing powders on the color stability of different types of composite resin restorative materials. MATERIAL AND METHODS: Thirty cylindrical specimens (15×2 mm) were prepared for each of 7 composite resin restorative materials. All specimens were polished with a series of aluminum oxide polishing discs (Sof-Lex). The prepared specimens of each composite resin were randomly divided into 3 groups of 10 specimens each, for control (Group-C) and two air-powder applications (Group-CP: Cavitron Prophy-Jet; Group-PS: Sirona ProSmile prophylaxis powder). A standard air-polishing unit (ProSmile Handly) was used. All specimens were air-powdered for 10 s at 4-bar pressure. The distance of the spray nosel from the specimens was approximately 10 mm and angulation of the nosel was 90°. Specimens were stored in 100 mL of coffee (Nescafe Classic) for 24 h at 37°C. Color measurement of all specimens was recorded before and after exposure to staining agent with a colorimeter (Minolta CR-300). Color differences (∆E*) between the 2 color measurements (baseline and after 24 h storage) were calculated. The data were analyzed with a 2-way ANOVA test, and mean values were compared by the Tukey HSD test (

Effects of polishing procedures on color stability of composite resins

The purpose of this study was to investigate the effect of different polishing methods on color stability of posterior, universal and nanohybrid composite resin restorative materials upon exposure to a staining agent. Twenty-five specimens were prepared for each of 5 different composite resins (Filtek Z250, Filtek P60, Quadrant LC, Grandio and Filtek Supreme). Specimens were divided into 5 groups and different polishing procedures, including polishing discs (Pd), polishing discs then diamond polishing paste (PdP), polishing discs then a liquid polishing system (Biscover) (PdB), and combinations of these (PdPB) were used. Unpolished specimens served as the control (C). The specimens were stored for 48 h in a coffee solution. The color of all specimens was measured before and after exposure with a colorimeter, and total color change (DE*) were calculated. The data were analyzed with a two-way ANOVA and the means were compared by Tukey HSD test (a=0.05). The lowest color difference was observed in the groups PdP and C, while the highest color difference was observed in PdPB, and PdB. When comparing the five different restorative materials, no significant difference was observed between FiltekP60 and FiltekZ250, and these materials demonstrated significantly less color change than Quadrant LC and the nanohybrid materials (Grandio, Filtek Supreme). The posterior (Filtek P60) and universal (Filtek Z250) composite resin restorative materials, which do not contain tetraethyleneglycol dimethacrylate (TEGDMA), were found to be less stainable than the nanohybrid (Grandio, Filtek Supreme) and universal (Quadrant LC) composite resins, which contain TEGDMA. The use of diamond polishing paste after polishing with polishing discs significantly decreased staining when compared to the groups that used polishing discs alone, for all restorative materials tested. The highest color change values were obtained for the specimens that were polished with the Biscover liquid polish system (PdB and PdPB groups)

İmalat Sektöründe Faaliyet Gösteren KOBİ’lerde İnsan Kaynakları Yönetimi Uygulamalarının Belirleyicileri: Eskişehir Örneği

İnsan kaynakları yönetimi (İKY) uygulamaları işletmelerin en önemli ve ikame edilmesi çok güç olan kaynaklarından olan çalışanlar ile işletme yönetimi arasındaki ilişkileri kapsayan akademik çalışma ve uygulama alanıdır. İnsan kaynakları uygulamaları bir işletmede insan kaynağının daha verimli ve daha etkili bir şekilde nasıl çalıştırılacağının anahtarıdır. Bu çalışmada, imalat sektöründe faaliyet gösteren KOBİ’lerdeki İKY uygulamaları Eskişehir örneği üzerinden incelenmiştir. Araştırmanın amacı doğrultusunda, Eskişehir ilinde imalat sektöründe faaliyet gösteren 50 ile 250 arası çalışan sayısına sahip küçük ve orta ölçekli işletmeler incelenmiştir. TOBB verilerine göre, 2017 yılında Eskişehir’de imalat sektöründe, 50 ila 250 kişi çalıştıran imalatçı işletme sayısı 146’dır. Bu işletmeler arasından maksimum çeşitlilik örneklemesi yöntemiyle seçilen 19 işletmede örnek olay yöntemiyle araştırma gerçekleştirilmiştir. Yapılandırılmış ve yarı-yapılandırılmış sorulardan oluşan bir görüşme formuyla KOBİ’lerin varsa insan kaynakları yöneticileri/uzmanları ve tepe yöneticileri ile görüşmeler yapılmıştır. Araştırma sonuçlarına göre işletmelerin büyüklüğü ve yaşının, müşterilerin gücünün ve resmi düzenlemelerin İKY uygulamalarının benimsenmesinde etkili olduğu bulunmuştur

İmalat Sektöründe Faaliyet Gösteren KOBİ’lerde İnsan Kaynakları Yönetimi Uygulamalarının Belirleyicileri: Eskişehir Örneği

İnsan kaynakları yönetimi (İKY) uygulamaları işletmelerin en önemli ve ikame edilmesi çok güç olan kaynaklarından olan çalışanlar ile işletme yönetimi arasındaki ilişkileri kapsayan akademik çalışma ve uygulama alanıdır. İnsan kaynakları uygulamaları bir işletmede insan kaynağının daha verimli ve daha etkili bir şekilde nasıl çalıştırılacağının anahtarıdır. Bu çalışmada, imalat sektöründe faaliyet gösteren KOBİ’lerdeki İKY uygulamaları Eskişehir örneği üzerinden incelenmiştir. Araştırmanın amacı doğrultusunda, Eskişehir ilinde imalat sektöründe faaliyet gösteren 50 ile 250 arası çalışan sayısına sahip küçük ve orta ölçekli işletmeler incelenmiştir. TOBB verilerine göre, 2017 yılında Eskişehir’de imalat sektöründe, 50 ila 250 kişi çalıştıran imalatçı işletme sayısı 146’dır. Bu işletmeler arasından maksimum çeşitlilik örneklemesi yöntemiyle seçilen 19 işletmede örnek olay yöntemiyle araştırma gerçekleştirilmiştir. Yapılandırılmış ve yarı-yapılandırılmış sorulardan oluşan bir görüşme formuyla KOBİ’lerin varsa insan kaynakları yöneticileri/uzmanları ve tepe yöneticileri ile görüşmeler yapılmıştır. Araştırma sonuçlarına göre işletmelerin büyüklüğü ve yaşının, müşterilerin gücünün ve resmi düzenlemelerin İKY uygulamalarının benimsenmesinde etkili olduğu bulunmuştur

Antinociceptive and anxiolytic-like effects of some compounds carrying benzothiazole ring

Bu çalışmanın amacı benzotiyazol halkası taşıyan bazı bileşiklerin antinosiseptif ve anksiyolitik-benzeri etkilerinin incelenmesidir. 40 mg/kg dozda uygulanan test bileşiklerinin antinosiseptif etkileri kuyruk sıkıştırma, sıcak plaka ve asetik asid ile indüklenen kıvranma testleri ile araştırılmıştır. Bileşiklerin anksiyolitik-benzeri etkilerini incelemek için delikli tahta ve yükseltilmiş artı labirent testleri gerçekleştirilmiştir. Farelerin motor koordinasyonlarını değerlendirmek üzere Rota-rod cihazı kullanılmıştır. Deneyler sonucunda 3f, 3g ve 3h kodlu bileşiklerin kuyruk sıkıştırma ve sıcak plaka testlerinde hayvanların reaksiyon sürelerini artırdığı ve 3e kodlu bileşiğin ise asetik asid ile indüklenen kıvranma testinde farelerin kıvranma sayılarını azalttığı belirlenmiştir. Diğer yandan, 3f, 3g ve 3h kodlu bileşikler delikli tahta testinde farelerin ilk baş daldırma sürelerini kısaltırken toplam baş daldırma sayılarını artırmıştır. Yükseltilmiş artı labirent testinde ise aynı türevlerin farelerin açık kola giriş sayılarının ve açık kolda kalma sürelerinin yüzdelerini artırdığı ortaya konulmuştur. Rota-rod testlerinde test bileşikleri farelerin dönen milden düşme sürelerini değiştirmemiştir. Tüm bu bulgular, 3f, 3g ve 3h kodlu bileşiklerin santral antinosiseptif ve anksiyolitik-benzeri etki gösterdiklerine; 3e kodlu bileşiğin ise periferal antinosiseptif etki gösterdiğine işaret etmektedir.The aim of this study was to examine the antinociceptive and anxiolytic-like effects of some compounds carrying benzothiazole ring. The antinociceptive effects of test compounds, administrated at a dose of 40 mg/kg, were investigated by tail clip, hot plate and acetic acid-induced writhing tests. Hole board and elevated plus maze tests were performed to evaluate the anxiolytic-like effects of the compounds. Rota-rod device was used to assess the motor coordinations of mice. As a result of the experiments, it was determined that compounds 3f, 3g and 3h increased the reaction times of animals in the tail clip and hot plate tests, and compound 3e reduced the writhing number of mice in the acetic acid-induced writhing test. On the other hand, in the hole board test, compounds 3f, 3g and 3h reduced the first head-dipping latencies of mice while increasing the total number of head-dips. In the elevated plus maze test, it has been shown that the same derivatives increase the percentages of open arm entries and time spent in the open arms. In the Rota-rod tests, test compounds did not change the falling time of mice from the rotating mill. All these findings point out that compounds 3f, 3g and 3h exhibit central antinociceptive and anxiolytic-like effects and compound 3e shows a peripheral antinociceptive effect

Knowing the ABCs: Teaching the principles of radiology to medical students in Turkey

Background: Radiology education in Turkey is mainly taught during clinical years of medical school and often lacks main principles. Exposure to the fundamentals of radiology at an early stage of medical education may drastically help students generate a better understanding of radiology and expand their interest in the specialty. With the Principles of Radiology Course that we provided, pre- and post-session tests, and assessment survey at the end of the course, we aimed to evaluate the effectiveness of such an online course among Turkish medical students. Methods: A total of nine online sessions on imaging modalities principles was developed by radiology professors. Each session was given through Zoom by radiologists from different U.S.-institutions to Turkish medical students from state (n = 33) and private (n = 8) universities. Pretests and post-tests were given to participants via Qualtrics before and after each session, respectively. Paired two-sample t-tests were conducted to detect the variance and p=-.05 was used as the significance level. An evaluation survey was distributed at the end of the course to collect their feedback through SurveyMonkey. Results: A total of 1,438 predominantly Turkish (99.32%) medical students engaged with this course. An average of 506 students completed both pre-test and post-test. There was a statistically significant (p <.001) increase in the scores in post-test (mean[range]:7.58[5.21–8.53]) relative to pre-test (mean[range]:5.10[3.52–8.53]). Four hundred and thirty-nine participants (F/M:63.33%/35.54%) completed the end-of-course survey. A total of 71% and 69.70% of the participants strongly agreed that the course would be useful in their clinical practice and had increased their understanding of radiology. They also reported that their level of confidence in the subjects had increased 68% and reached a weighted average of 3.09/4. The survey revealed that 396 (90.21%) of the participants strongly or somewhat agree that introductory principles and concepts should be presented in earlier years of medical education. Compared to in-person education, 358 (81.55%) found the course extremely or very convenient. Conclusion: Online lecture series consisting of the principles of the radiological imaging modalities can be offered to Turkish medical students to enhance their grasp of the various imaging modalities and their correct clinical application

A Survey Study on Evaluation and Management of Nocturnal Enuresis in Pediatricians and Family Physicians

Objective:Nocturnal enuresis (NE) is one of the most common disorders in pediatric urology, and patients often turn to family physicians (FP) and pediatricians (P) initially. The aim of this study was to understand the awareness, self-confidence and suggestions of physicians regarding the management of NE.Materials and Methods:In this study, 360 FP and family medicine residents (FMR), as well as 280 P and pediatrics residents (PR), were contacted through a cellular phone texting system. A simple multiple-choice questionnaire (Surveymonkey®) consisting of 10 questions was used to gather data. The survey included questions about their experience, training, evaluation, and management of NE.Results:A total of 119 FPs and Ps (18.5%) filled the questionnaire. Thirty (25.21%) of the participants were P, 27 (22.69%) PR, 3 (2.52%) FP and 59 (49.58%) FMR. The rate of physicians who encounter at least 5 children with NE per month is 31.33%. The mean self-confidence in the management of NE was 4.5 out of 10. The self-confidence of pediatricians was significantly higher than that of PR and FMR (p<0.001, p<0.001). Most (n=78, 65.55%) of the participants stated that they received training on EN during medical faculty and 62 (52.10%) during residency. Psychological problems (89.92%), sleep disorders (78.15%), and excessive fluid intake (75.63%) were the most frequently considered factors in etiology. While most responders (75.63%) considered dietary regulation and behavioral interventions as the first-line treatment, 25.21% consult a pediatric urologist and only 1.6% recommend medical treatment.Conclusion:Although FP and P admit they had training on NE, they mostly felt incompetent to manage NE and exclusively avoided pharmacological treatment

Crizotinib efficacy and safety in patients with advanced NSCLC harboring MET alterations: A real-life data of Turkish Oncology Group

Crizotinib is a multikinase inhibitor, effective in non-small cell lung cancer (NSCLC) harboring mesenchymal-epidermal transition (MET) alterations. Although small prospective studies showed efficacy and safety of crizotinib in NSCLC with MET alterations, there is limited real-life data. Aim of this study is to investigate real-life efficacy and safety of crizotinib in patients with advanced NSCLC harboring MET alterations. This was a retrospective, multicenter (17 centers) study of Turkish Oncology Group. Patients' demographic, histological data, treatment, response rates, survival outcomes, and toxicity data were collected. Outcomes were presented for the study population and compared between MET alteration types. Total of 62 patients were included with a median age of 58.5 (range, 26-78). Major histological type was adenocarcinoma, and 3 patients (4.8%) had sarcomatoid component. The most common MET analyzing method was next generation sequencing (90.3%). MET amplification and mutation frequencies were 53.2% (n = 33) and 46.8% (n = 29), respectively. Overall response rate and disease control rate were 56.5% and 74.2% in whole study population, respectively. Median progression free survival (PFS) was 7.2 months (95% confidence interval [CI]: 3.8-10.5), and median overall survival (OS) was 18.7 months (95% CI: 13.7-23.7), regardless of treatment line. Median PFS was 6.1 months (95% CI: 5.6-6.4) for patients with MET amplification, whereas 14.3 months (95% CI: 6.7-21.7) for patients with MET mutation (P = .217). Median PFS was significantly longer in patients who have never smoked (P = .040), have good performance score (P < .001), and responded to the treatment (P < .001). OS was significantly longer in patients with MET mutation (25.6 months, 95% CI: 15.9-35.3) compared to the patients with MET amplification (11.0 months; 95% CI: 5.2-16.8) (P = .049). In never-smokers, median OS was longer than smoker patients (25.6 months [95% CI: 11.8-39.3] vs 16.5 months [95% CI: 9.3-23.6]; P = .049). The most common adverse effects were fatigue (50%), peripheral edema (21%), nausea (29%) and diarrhea (19.4%). Grade 3 or 4 adverse effects were observed in 6.5% of the patients. This real-life data confirms efficacy and safety of crizotinib in the treatment of advanced NSCLC harboring MET alteration

Yüksek basınç ön işleminin seçilmiş meyve ve sebzelerin kurutma hızları üzerine etkisinin belirlenmesi.

Drying is a process of moisture removal due to simultaneous heat and mass transfer. High hydrostatic pressure (HHP) processing subjects liquid and solid foods, with or without packaging, to pressures between 100 and 800 MPa. The application of HHP affects cell wall structures, leaving the cells more permeable, facilitating the diffusion and providing higher drying rates. In this study, two variety of apples, i.e. Amasya and red delicious, green beans and carrots were pretreated with HHP at different pressure-time-temperature combinations (100 300 MPa for 5 45 min at 20 and 35°C) prior to drying. Hot air drying experiments were carried at different temperatures (27, 45, 65, and 85°C) and air velocity of 0.4 and 0.8 m/s. To obtain the drying data, samples were subjected to hot air drying under constant external conditions. The applicability of 14 kinetic models selected from the literature for the drying of fruits and vegetables was determined by appropriate statistical analyses procedures. Improving the drying conditions by increasing the drying temperature generally masked the effect of HHP pretreatment on drying rate. Only for green beans, HHP treatments at 20°C decreased the drying rate. Generally pressures of HHP pretreatment higher than 100 MPa caused cell permeabilization resulted in higher drying rates for apples and carrots. Among the 14 models, modified Page model for apples, and modified Page and two term exponential models for green beans and carrots were found to best explain the drying behaviors.M.S. - Master of Scienc

Avrupa Parlementosu'nda yer alan siyasi grupların Türkiye'ye ilişkin olarak aldıkları kararlarda grupiçi mutabakat ve gruplararası ittifaklar: 1980-1996

This thesis analyzes the cohesiveness, and voting likeliness of the political groups in the European Parliament on Turkey between 1980-1996. The thesis consists of two main parts: in the first part the structure, and historical evoluation of the European Parliament has been analyzed. In the second part, the changes in Turkish politics between 1980-96, and the cohesiveness, and voting alliances of the political groups have been analyzed by using roll call vote data.M.S. - Master of Scienc