Evaluation of prophylactic and therapeutic effects of ruscogenin on acute radiation proctitis

Erkan Yavuz,Onur Olgac Karagulle,Gulcin Ercan,Atilla Celik,Hakan Yigitbas,Busra Yaprak Bayrak,Rumeysa Tartar,Ramazan Kusaslan,Yuksel Altine,Osman Bilgin Gulcicek 대한외과학회 2018 Annals of Surgical Treatment and Research(ASRT) Vol.94 No.4

Purpose: Radiation proctitis (RP) is inflammation and damage to the rectum, manifested secondary to ionizing radiation utilized for treatment. In this study, we evaluated the anti-inflammatory therapeutical and protective effects of ruscogenin in a model of acute RP. Methods: Thirty-two Sprague-Dawley rats were divided into 4 groups (n = 8) as sham, control, treatment, and prophylaxis groups. Prophylaxis group and treatment group were dosed ruscogenin by oral gavage for 14 days pre- and postradiation. At the end of the 28th day, all subjects were sacrificed. Results: Histopathological analysis showed a significant increase in cryptitis abscess, cryptitis and reactive atypia, and depth of lymphocytic infiltration of the control group, compared to the other groups (P < 0.05), while treatment and prophylaxis groups showed significant decreases (P < 0.05). Immunohistochemical analysis indicated that immunoreactivity were significantly higher in control group (P < 0.05, P < 0.001, and P < 0.01, respectively), but vice versa for treatment and prophylaxis groups. There was not any significant difference for fibroblast growth factor 2 immunoreactivity. The epithelium of control rectums indicated an increase in TNF-α immunoreactivity while other groups had significant decrease (P < 0.01). Electron microscopical findings were parallel to light microscopy. Conclusion: In this study, ruscogenin was observed to be effective on prophylaxis or treatment of acute RP. Although there are various reports on the treatment of the rectum damaged by acute RP in the literature, this could be the first study since there is no research indicating the ultrastructural effect of ruscogenin.

PLM Services 를 이용한 이기종 PDM 시스템의 통합

Erkan Gunpinar,김병철(Byungchul Kim),천상욱(Sanguk Cheon),한순흥(Soonhung Han) (사)한국CDE학회 2006 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2006 No.2

Theoretical Models for Tie Bar Maximum Axial Force Demand in Composite Plate Shear Walls–Concrete Filled

Erkan Polat 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.4

This paper presents theoretical models developed for the prediction of the maximum axial force demands of tie bars of planar composite plate shear walls–concrete fi lled (C-PSW/CF). In the development of the theory, a previously benchmarked fi nite element (FE) wall model was used with some modifi cations. The results from the FE models were used to demonstrate the formation of the tie bar axial force demands, passive lateral confi ning pressure, concrete confi nement, eff ectively confi ned concrete core and to develop theoretical models for the prediction of tie bar maximum force demands. The proposed method accounts for various aspects of wall geometry such as horizontal and vertical tie bar spacings, steel plate thickness, and wall thickness. The predictions of the proposed theoretical models were compared with the predictions of FE analyses by performing a parametric study involving C-PSW/CF having diff erent tie bar spacings, plate thickness, wall thickness, and wall depths. Past experimental research available in the literature were used to evaluate the signifi cance of the theoretical model in predicting tie bar maximum axial force demands. Tie bar axial force demand due to the confi nement eff ect is not currently considered in the design of tie bars and there is no theoretical approach in the literature that considers the eff ect of confi nement on the tie bar axial force demand. The theoretical models presented in this study allow the determination of the maximum axial force demands due to the confi nement eff ect on planar C-PSW/CF tie bars without the need for complex and costly numerical analysis.

Solving design optimization problems via hunting search algorithm with Levy flights

Erkan Doğan 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.2

This study presents a hunting search based optimum design algorithm for engineering optimization problems. Hunting search algorithm is an optimum design method inspired by group hunting of animals such as wolves, lions, and dolphins. Each of these hunters employs hunting in a different way. However, they are common in that all of them search for a prey in a group. Hunters encircle the prey and the ring of siege is tightened gradually until it is caught. Hunting search algorithm is employed for the automation of optimum design process, during which the design variables are selected for the minimum objective function value controlled by the design restrictions. Three different examples, namely welded beam, cellular beam and moment resisting steel frame are selected as numerical design problems and solved for the optimum solution. Each example differs in the following ways: Unlike welded beam design problem having continuous design variables, steel frame and cellular beam design problems include discrete design variables. Moreover, while the cellular beam is designed under the provisions of BS 5960, LRFD-AISC (Load and Resistant Factor Design-American Institute of Steel Construction) is considered for the formulation of moment resisting steel frame. Levy Flights is adapted to the simple hunting search algorithm for better search. For comparison, same design examples are also solved by using some other well-known search methods in the literature. Results reveal that hunting search shows good performance in finding optimum solutions for each design problem.

Results of Endoscopic Surgery in Patients with Pituitary Adenomas : Association of Tumor Classification Grades with Resection, Remission, and Complication Rates

Erkan, Buruc,Barut, Ozan,Akbas, Ahmet,Akpinar, Ebubekir,Akdeniz, Yasemin Sefika,Tanriverdi, Osman,Gunaldi, Omur The Korean Neurosurgical Society 2021 Journal of Korean neurosurgical society Vol.64 No.4

Objective : The endoscopic endonasal transsphenoidal approach is a widely-used method for the surgical treatment of pituitary adenomas. We aimed to evaluate the results of endoscopic surgery by comparing preoperative classification methods and investigating their relationship with postoperative resection and remission rates and complications. Methods : We retrospectively reviewed the medical records of 236 patients (118 males) who underwent surgery for pituitary adenomas. Preoperative Knosp classification, tumor size (TS), suprasellar extension (SSE), postoperative resection and remission rates, and complications were evaluated. Results : The follow-up period was 3 months to 6 years. The patients' ages ranged between 16 and 84 years. Endocrinologically, 114 patients (48.3%) had functional adenoma (FA), and 122 patients (51.7%) had non-functional adenoma (NFA). Among the FA group, 92 (80.7%) showed remission. A statistically significant difference was found between patients with and without remission in terms of the Knosp, TS, and SSE classifications (p<0.01). Knosp, TS, and SSE classification grades were found to be correlated with the resection rates (p<0.01). Meningitis was seen in seven patients (3.0%), diabetes insipidus in 16 (6.9%; permanently in two [0.9%]), and rhinorrhea in 19 (8.1%). Thirty-six patients (15.3%) developed pituitary insufficiency and received hormone replacement therapy. Conclusion : The resection categories and remission rates of FAs were directly proportional to the adenoma sizes and Knosp grades, while the degree of suprasellar growth further complicated resection and remission rates. Adenoma sizes less than 2 cm and SSEs less than 1 cm are associated with favorable remission and resection rates.

Burr Measurement Method Based on Burr Surface Area

Erkan Bahçe,Burak Özdemir 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.4

One of the major issues of drilling operations pertains to the formation of burrs, which greatly influences the accuracy of the manufactured parts, and, thus, the capability to meet the desired performance of the part. To remove or prevent these burrs, their geometry must be measured accurately, even though they are sharp and irregular in shape. The accurate measurement of the geometry of a burr will lead to the development of a proper deburring method. In this work, the authors describe a simple and convenient new measurement technique for drilling burr profiles and a developed drilling burr measurement system based on surface area. The new method presented in this research aims at providing a comparative evaluation of the height, arc length and area of the burr, as well as its geometrical characteristics. When the average height and arc length measurement methods are compared with the area measurement method, large deviations in burr height are detected. In particular, these deviations increase more in non-uniform burrs. In the measurement of burr size, the new developed method is based on area measurement and is carried out using a computer. Therefore, there is no deviation between the measurements. In contrast, the average deviation ranges for the height and arc length measurement methods are found to be 9.94–48.14% and 6.07–18.82%, respectively.

Mucocutaneous Lesions of Behcet's Disease

Erkan Alpsoy,Christos Constantin Zouboulis,George Edward Ehrlich 연세대학교의과대학 2007 Yonsei medical journal Vol.48 No.4

Behcet's disease is particularly prevalent in “Silk Route” populations, but it has a global distribution. The diagnosis of the disease is based on clinical criteria as there is as yet no pathognomonic test, and mucocutaneous lesions, which figure prominently in the presentation and diagnosis, may be considered the diagnostic hallmarks. Among the internationally accepted criteria, painful oral and genital ulcers, cutaneous vasculitic lesions and reactivity of the skin to needle prick or injection (the pathergy reaction) are considered hallmarks of Behcet's disease, and often precede other manifestations. Their recognition may permit earlier diagnosis and treatment, with salutary results. This paper describes the various lesions that constitute the syndrome and focuses on those that may be considered characteristic.

DECOMPOSING SHIP HULL TO MANUFACTURABLE PLATES USING MESH MODEL

Erkan GUNPINAR,Hiromasa SUZUKI (사)한국CDE학회 2013 한국CAD/CAM학회 국제학술발표 논문집 Vol.2010 No.8

Efficacy and Safety of Intravitreal Dexamethasone Implants for Treatment of Refractory Diabetic Macular Edema

Erkan Unsal,Kadir Eltutar,Pınar Sultan,Sezin Ozdogan Erkul,Ozen Ayranci Osmanbasoglu 대한안과학회 2017 Korean Journal of Ophthalmology Vol.31 No.2

Purpose: To evaluate the safety and efficacy of intravitreal dexamethasone (IVD) implants in eyes with diabeticmacular edema that did not respond to previous treatment. Methods: We included 46 eyes of 46 patients in this retrospective study. Each month, we recorded patient visualacuity with logarithm of the minimum angle of resolution using the Early Treatment Diabetic RetinopathyStudy chart, central macular thickness measurements with optical coherence tomography, intraocular pressure(IOP), and posttreatment complication occurrence. Results: The mean follow-up time was 8.95 ± 1.33 months (range, 6 to 12). Best-corrected visual acuity improvedsignificantly in the first 4 months after IVD, but no statistically significant change was observed over the following2 months. Although a statistically significant decrease in central macular thickness was observed in thefirst 3 months, the change was not statistically significant in the following 3 months. There was a statisticallysignificant increase in IOP in the first 2 months, but no statistically significant change was observed in the followingmonths. IOP was controlled with medication in all patients with elevated IOP. Of the 26 phakic patients,two had cataracts requiring surgery. Conclusions: Cases of refractory diabetic macular edema that did not respond to previous treatment, such asanti-vascular endothelial growth factor injections and laser photocoagulation, exhibited improvements in visualacuity and decreases in retinal thickness after IVD implantation. Both functional and anatomical effects wereobserved in the first 3 months after injection. Repeat injections and frequent examination might be required forcontinued improvement. Side effects, such as cataracts and elevation of IOP, may require medical or surgicaltreatment.

Low velocity impact behavior of concrete beam strengthened with CFRP strip

Erkan Kantar,Özgür Anil 국제구조공학회 2012 Steel and Composite Structures, An International J Vol.12 No.3

Nowadays CFRP (Carbon Fiber Reinforced Polymer) became widely used materials for the strengthening and retrofitting of structures. Many experimental and analytical studies are encountered at literature about strengthening beams by using this kind of materials against static loads and cyclic loads such as earthquake or wind loading for investigating their behavior. But authors did not found any study about strengthening of RC beams by using CFRP against low velocity impact and investigating their behavior. For these reasons an experimental study is conducted on totally ten strengthened RC beams. Impact loading is applied on to specimens by using an impact loading system that is designed by authors. Investigated parameters were concrete compression strength and drop height. Two different sets of specimens with different concrete compression strength tested under the impact loading that are applied by dropping constant weight hammer from five different heights. The acceleration arises from the impact loading is measured against time. The change of velocity, displacement and energy are calculated for all specimens. The failure modes of the specimens with normal and high concrete compression strength are observed under the loading of constant weight impact hammer that are dropped from different heights. Impact behaviors of beams are positively affected from the strengthening with CFRP. Measured accelerations, the number of drops up to failure and dissipated energy are increased. Finite element analysis that are made by using ABAQUS software is used for the simulation of experiments, and model gave compatible results with experiments.