Diffuse Myocardial Uptake of 99mTc-HDP in Multiple Myeloma

Koray Demirel,Murat Sadic,Meliha Korkmaz,Aylin Comak,Hasan Ikbal Atilgan,Gökhan Koca 대한핵의학회 2013 핵의학 분자영상 Vol.47 No.3

Soft tissue uptake is a rare finding in bone scintigraphy,with an incidence of 2%. Although the mechanism has not yet been fully clarified, several causes have been reported for this unusual uptake pattern. This paper presents a case of diffuse myocardial accumulation of technetium-99m hydroxymethylene diphosphonate (99mTc-HDP) without either solid/visceral organ or soft tissue with multiple myeloma (MM) in skeletal scintigraphy. A 93-year-old man with hypertension and chronic heart failure for 14 years underwent bone scanning due to a 2-month history of back pain within a 1-year period of MM. Three hours later,99mTc-HDP late static images showed diffuse myocardial radiotracer accumulation and there were no other sites of abnormal soft tissue or visceral uptake. Myocardial accumulation had disappeared on 24-h delayed static images. This accumulation was thought to be related with AL-type amyloidosis associated with MM.

Cyclic fatigue life of Tango-Endo, WaveOne GOLD, and Reciproc NiTi instruments

Koray Yılmaz,Taha Özyürek 대한치과보존학회 2017 Restorative Dentistry & Endodontics Vol.42 No.2

Objectives: To compare the fatigue life of Tango-Endo, WaveOne GOLD, and Reciproc NiTi instruments under static model via artificial canals with different angles of curvature. Materials and Methods: Reciproc R25, WaveOne GOLD Primary, and Tango- Endo instruments were included in this study (n = 20). All the instruments were rotated in artificial canals which were made of stainless steel with an inner diameter of 1.5 mm, 45°, 60°, and 90° angles of curvatures and a radius of curvature of 5 mm until fracture occurred, and the time to fracture was recorded in seconds using a digital chronometer. The data were analyzed using Kruskal-Wallis and post-hoc Dunn tests were used for the statistical analysis of data in SPSS 21.0 software. Results: Tango- Endo files were found to have significantly higher values than WaveOne GOLD and Reciproc files in terms of fatigue life (p < 0.05). However, there was no statistically significant difference between fatigue life of Reciproc and WaveOne GOLD files (p > 0.05). It was determined that increasing the angle of curvature of the stainless canals caused significant decreases in fatigue life of all of three files (p < 0.05). Conclusions: Within the limitations of the present study, the cyclic fatigue life of Tango-Endo in canals having different angles of curvature was statistically higher than Reciproc and WaveOne GOLD.

Promoting Sport Tourism:A Success Story in Turkey

Koray Başol,R. Aysen Wolff,Aysa İ,Erdoğan,Emre Tilev 세계문화관광학회 2011 Conference Proceedings Vol.12 No.-

The purpose of this study is to evaluate sport tourism and how a country develops into a major sport destination. Governments and companies are well aware of future trends in tourism and consequently promote international events with the potential to draw large audience and more famous participants. Arel University allows students in the MBA program to research success stories like Formula 1(auto-sports) in order to develop a positioning and targeting strategy for the developing economy.

The prognostic value of lymph node ratio in stage IIIC cervical cancer patients triaged to primary treatment by radical hysterectomy with systematic pelvic and para-aortic lymphadenectomy

Koray Aslan,Mehmet Mutlu Meydanli,Murat Oz,Yusuf Aytac Tohma,Ali Haberal,Ali Ayhan 대한부인종양학회 2020 Journal of Gynecologic Oncology Vol.31 No.1

Objective: The aim of this study was to determine the prognostic value of lymph node ratio (LNR) in women with 2018 International Federation of Gynecology and Obstetrics stage IIIC cervical cancer. Methods: In this retrospective dual-institutional study, a total of 185 node-positive cervical cancer patients who had undergone radical hysterectomy with systematic pelvic and para-aortic lymphadenectomy were included. All of the patients received adjuvant chemoradiation after surgery. LNR was defined as the ratio of positive lymph nodes (LNs) to the total number of LNs removed. The patients were categorized into 2 groups according to LNR; LNR <0.05 and LNR ≥0.05. The prognostic value of LNR was evaluated with univariate log-rank tests and multivariate Cox regression models. Results: A total of 138 patients (74.6%) had stage IIIC1 disease and 47 (25.4%) patients had stage IIIC2 disease. With a median follow-up period of 45.5 months (range 3–135 months), the 5-year disease-free survival (DFS) rate was 62.5% whereas the 5-year overall survival (OS) rate was 70.4% for the entire study population. The 5-year DFS rates for LNR <0.05 and LNR ≥0.05 were 78.2%, and 48.4%, respectively (p<0.001). Additionally, the 5-year OS rates for LNR <0.05 and LNR ≥0.05 were 80.6%, and 61.2%, respectively (p=0.007). On multivariate analysis, LNR ≥0.05 was associated with a worse DFS (hazard ratio [HR]=2.12; 95% confidence interval [CI]=1.15–3.90; p=0.015) and OS (HR=1.95; 95% CI=1.01–3.77; p=0.046) in women with stage IIIC cervical cancer. Conclusions: LNR ≥0.05 seems to be an independent prognostic factor for decreased DFS and OS in stage IIIC cervical carcinoma.

Maxillary expansion with the memory screw

Koray Halicio?lu,Ali Kiki,?brahim Yavuz 대한치과교정학회 2012 대한치과교정학회지 Vol.42 No.2

Objective: The purpose of this study was to investigate the effects of a newly developed rapid maxillary expansion screw-the memory screw-over 6 months. Methods: Five subjects, aged between 11.7 and 13.75 years, were enrolled in this study. All subjects underwent placement of a maxillary expansion appliance containing superelastic nickel-titanium open-coil springs in its screw bed. The parents of the patients and/or the patients themselves were instructed to activate the expansion screw by 2 quarter-turns 3 times a day (morning, midday, and evening; 6 quarter-turns a day). The mean expansion period was 7.52 ± 1.04 days. Dentoskeletal effects of the procedure, including dentoalveolar inclination, were evaluated. Measurements of all the parameters were repeated after 6 months of retention in order to check for relapse. Results: Sella-Nasion-A point (SNA) and Sella-Nasion/Gonion-Menton angles increased, and Sella-Nasion-B point (SNB) angle decreased in all the subjects during the expansion phase. However, they approximated to the initial values at the end of 6 months. On the other hand, the increments in maxillary apical base (Mxr-Mxl) and intermolar widths was quite stable. As expected, some amount of dentoalveolar tipping was observed. Conclusions: The newly developed memory expansion screw offers advantages of both rapid and slow expansion procedures. It widens the midpalatal suture and expands the maxilla with relatively lighter forces and within a short time. In addition, the resultant increments in the maxillary apical base and intermolar width remained quite stable even after 6 months of retention.

COMPARISON OF REPAIR INTEGRITY AND FUNCTIONAL OUTCOMES BETWEEN KNOT-TYING AND KNOTLESS SUTURE-BRIDGE ARTHROSCOPIC ROTATOR CUFF REPAIR: A PROSPECTIVE RANDOMIZED CLINICAL TRIAL

Koray Sahin,Fatih Senturk,Mehmet Ersin,Mechmet Chodza,Ufuk Arzu,Ali Ersen 대한견주관절의학회 2021 대한견주관절학회 학술대회논문집 Vol.2021 No.3

Introduction and Background Suture-bridge (SB) rotator cuff repair (RCR) is widely used due to its superior biomechanical and clinical outcomes. However, knot-tying SB technique has been suspected to compromise the tendinous biology and to cause strangulation and medial repair failures. Therefore, knotless SB technique has been proposed to decrease retear rates. The purpose of this study is to compare clinical, structural outcomes and retear patterns between two techniques Material and Method 104 patients with full-thickness rotator cuff tear were randomly and prospectively allocated to knot-tying (group I) or knotless (group II) SB surgeries. Clinical outcome measures included range of motion values, subjective pain scores (VAS) and functional scores (Constant score). Repair integrity was evaluated with magnetic resonance imagings using Sugaya classification. Retears were also classified according to their patterns as type 1 (lateral) and type 2 (medial). 88 patients completed the follow-up period and were included to final analysis. Results Mean age of patients was 54.3 years in group I and 55.8 years in group II. Mean follow-up period was 25.4 and 23.3 months respectively. Mean pain score of group I decreased from 7.4 to 1.0 (p<0.0001). The corresponding values for group II decreased from 7.1 to 1.3 (p<0.0001). In group I, mean Constant score increased from 51.7 to 86.0 (p<0.0001) and in group II, mean Constant score increased from 49.4 to 87.2 (p<0.0001). There was not statistically significant difference between two groups regarding post-operative pain and functional scores (p>0.05). Post-operative MR imaging revealed that the retear rate was 19.0% (8/42) in group I and 28.3% (13/46) in group II (p>0.05). Type 2 failure rate was 75.0% (6/8) in group I and 23.1% (3/13) in group II (p=0.03). Conclusions Both techniques showed excellent improvement and comparable clinical outcomes. However, there was no significant difference in retear rates between techniques. Type 2 failure rate was higher in knot-tying technique.

Investigation of the Solid Lubrication Effect of Commercial Boron-based Compounds in End Milling

Koray K l çay,Mustafa Ulutan 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.4

Solid lubricants are environmental friendly (green) because they reduce tool wear, the usage of chemical-based cutting fluids, friction and heat during the manufacturing process. In addition, solid lubricants are reusable and easy to handle. Therefore, the solid lubricants that are required in manufacturing processes are efficient, inexpensive, and easily acquired. The present work investigates the usage of different commercial boron compounds (boric acid, boron oxide, boron pentahydrate, and Etidot-67) as lubricants and their performances regarding surface quality, cutting forces and tool wear while machining AISI 1020 steel using HSS end mills. The performance of boron compounds was studied in comparison with that of dry machining. During the metal-cutting process, constant values of the depth of cut, cutting speed and feed rate were used. In the process of milling, the cutting forces were measured with the dynamometer simultaneously. The results indicate that there is a considerable improvement in the machining performance with commercial boron compounds. As a result of using boric acid as a solid lubricant, tool wear resistance improved, the surface roughness values decreased approximately 20 to 32%, and the values of the cutting forces decreased by approximately 15 to 50% compared with dry end milling.

In vitro comparison of the cyclic fatigue resistance of HyFlex EDM, One G, and ProGlider nickel titanium glide path instruments in single and double curvature canals

Koray Yılmaz,Gülşah Uslu,Taha Özyürek 대한치과보존학회 2017 Restorative Dentistry & Endodontics Vol.42 No.4

Objectives: It was aimed to compare the cyclic fatigue resistances of ProGlider (PG), One G (OG), and HyFlex EDM (HEDM) nickel titanium glide path files in single- and double-curved artificial canals. Materials and Methods: 40 PG (16/0.02), 40 OG (14/0.03), and 40 HEDM (10/0.05) single-file glide path files were used in the present study. Sixty files were subjected to cyclic fatigue test by using double-curved canals and 60 files by using single-curved canal (n = 20). The number of cycles to fracture (NCF) was calculated and the length of the fractured fragment (FL) was determined by a digital micro-caliper. Twelve pieces of fractured files were examined with scanning electron microscope to determine fracture types of the files (n = 2). The NCF and the FL data were analyzed using one-way analysis of variance and post hoc Tukey test using SPSS 21 software (p < 0.05). Results: In all of the groups, NCF values were significantly lower in double-curved canals when compared to single-curved canals (p < 0.05). For both of single- and double-curved canals, NCF values of HEDM group in apical and coronal curvatures were found to be significantly higher than NCF values of PG and OG groups (p < 0.05). In both of single- and double-curved canals, NCF value of PG group was found significantly higher than OG group (p < 0.05). Conclusions: Within the limitations of this study, HEDM glide path files were found to have the highest cyclic fatigue resistance in both of single- and double-curved canals.

What is the prognostic importance of lymphovascular space invasion in the absence of lymph node metastasis for early-stage endometrial cancer?

Koray Aslan,Mehmet Mutlu Meydanli 대한부인종양학회 2021 Journal of Gynecologic Oncology Vol.32 No.5

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Investigations on the effects of mouthrinses on the colour stability and surface roughness of different dental bioceramics

Koray Soygun,Osman Varol,Ali Ozer,Giray Bolayir 대한치과보철학회 2017 The Journal of Advanced Prosthodontics Vol.9 No.3

PURPOSE. In this study, three bioceramic materials, [IPS Empress CAD (Ivoclar), IPS e.max CAD (Ivoclar), and Lava Ultimate CAD (3M ESPE)] were treated with three commercial mouthrinses [Listerine, Tantum Verde, and Klorhex]; and changes in colour reflectance and surface roughness values were then quantitatively assessed. MATERIALS AND METHODS. One hundred and twenty ceramic samples, with dimensions of 2 × 12 × 14 mm, were prepared and divided into nine sample groups, except three control samples. The samples were immersed in the mouthrinse solutions for 120 hrs, and changes in colour reflectance and surface roughness values were measured by UV light spectrophotometry (Vita Easyshade; VITA Zahnfabrik) and by profilometer device (MitutoyoSurftest SJ-301), respectively. The change of surface roughness was inspected by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). RESULTS. There was a positive correlation between the ΔE and increase in the surface roughness. Two of the ceramic materials, IPS Empress and Lava Ultimate, were affected significantly by the treatment of the mouthrinse solutions (P<.05). The most affecting solution was Tantum Verde and the most affected material was Lava Ultimate. As expected, the most resistant material to ΔE and chemical corrosion was IPS e max CAD among the materials used. CONCLUSION. This work implied that mouthrinse with lower alcohol content had less deteriorating effect on colour and on the surface morphology of the bioceramic materials.