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Comparison of the Retinomax hand-held autorefractor versus table-top autorefractor and retinoscopy

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International Journal of Ophthalmology(English edition) 2014年第3期7卷 491-495页

作者： Ibrahim Tuncer mehmet Ozgur Zengin Eyyup karahan Alfagoz Eye Center Department of Ophthalmology Izmir University Faculty of Medicine

AIM:To compare noncycloplegic and cycloplegic results of Retinomax measurements with findings achieved after cycloplegia using table-top autorefractor and ***:The study included 127 patients(mean age96.7mo,range 21 to 221).Retinomax(Rmax)(Nikon Inc.,Japan)was used to obtain noncycloplegic *** cycloplegia,refraction was measured with Rmax,table-top autorefractor(TTR)(Nikon NRK 8000,Inc.,Japan)and *** values of sphere,spherical equivalent,cylinder and axis of cylinder were recorded for Rmax,TTR and retinoscopy in each *** results were analyzed ***:The mean spheric values(SV),spherical equivalent values(SEV)and cylindrical values(CV)of the noncycloplegic Rmax(SV:0.64 D,SEV:0.65 D and CV:0.03 D,respectively)were found to be significantly lower than cycloplegic TTR(1.43 D,1.38 D and 0.3 D;P=0.012,P=0.011 and P=0.04,respectively)and retinoscopy(1.34 D,1.45 D and 0.23 D;P=0.04,P=0.002 and P=0.045,respectively).Mean cycloplegic SV,SEV,CV were not significantly different between Rmax and TTR,Rmax and retinoscopy,TTR and *** or noncycloplegic axis values were not different between any ***:Rmax may be used successfully as a screening tool but may not be accurate enough for actual spectacle *** Rmax measurements may be able to identify refractive error in children because of approximate results to retinoscopy.

关键词： autorefractor hand-held refractors retinoscopy Retinomax

Retinal nerve fiber layer thickness changes in obstructive sleep apnea syndrome: one year follow-up results

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International Journal of Ophthalmology(English edition) 2014年第4期7卷 704-708页

作者： mehmet Ozgur Zengin Ibrahim Tuncer Eyyup karahan Department of Ophtalmology Izmir University Faculty of Medicine Alfagoz Eye Center

·AIM: To investigate the retinal nerve fiber layer(RNFL)thickness changes in patients with obstructive sleep apnea syndrome(OSAS) for one year follow-up. To discuss the possibility of detecting tendency of glaucoma in this population by using spectral domain optical coherence tomography(3D-OCT-2000 Spectral domain).·METHODS: After polysomnographic study, all subjects(64 OSAS patients and 40 controls) underwent detailed ophthalmological examination. After these examinations,patients with glaucoma and patients who had ophthalmological and/or systemic disease were excluded from the ***, 20 patients in OSAS group and five patients in controls were excluded from the study in the first examination and follow-up period. The RNFL thickness was assessed with OCT. Forty-four OSAS patients and 35 control subjects were followed up for12 mo. RNFL thickness change and OSAS patients were evaluated for severity of disease by Apnea-Hypopnea Index(AHI).·RESULTS: Forty-four OSAS patients and 35 controls were enrolled in the study. Statistically significance was found between OSAS patients and controls at the 12 *** RNFL thickness was found to be significantly lower in last measurements in OSAS patients when compared with first measurements and control subjects(P <0.001, 0.002, respectively). There was a statistically significant correlation among AHI, and RNFL thickness(P <0.05).·CONCLUSION: The results suggest that the patients with OSAS were related with a proportional decrease in the RNFL thickness. These patients should be followed up regularly for glaucomatous changes. Detecting more RNFL thinning in severe OSAS was important.

关键词： obstructive sleep apnea syndrome optical coherence tomography retinal nerve fiber layer thickness

Spontaneous resolution of macular edema after silicone oil removal

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International Journal of Ophthalmology(English edition) 2014年第6期7卷 1005-1009页

作者： Eyyup karahan Ibrahim Tuncer mehmet Ozgur Zengin Cem Kucukerdonmez Suleyman Kaynak Alfagoz Eye Center Street of MithatpasaBalcovaIzmir 35330Turkey Department of Ophthalmology Izmir UniversityYeni Girne BoulevardKarsiyakaIzmir 35510Turkey Department of Ophthalmology Dokuz Eylul UniversityIzmir 35340Turkey

AIM: To investigate the macular changes in eyes filled with silicone oil(SO) and course of these changes after SO removal. METHODS: A retrospective optical coherence tomography scan review was conducted for twenty-four patients who underwent uncomplicated pars plana vitrectomy with SO tamponade for complex retinal detachments were detected with optical coherence tomography before, and one week, one month and three months after SO ***: Mean duration of SO tamponade was 3.6±1.0mo(range 3-7mo). Cystoid macular edema(CME) was detected in 3 eyes before SO removal. Submacular fluid was represented in 1 eye before silicone SO *** of CME and submacular fluid was achieved1 mo after SO removal in all eyes. Mean best corrected visual acuity(BCVA) was 1.15 ±0.65(range, hand movement to 0.2) before SO removal in the eyes without macular changes. After SO removal, the mean BCVA values at 1wk and 1 and 3mo, and 0.82 ±0.23, 0.76 ±0.21,and 0.70 ±0.19, all of which were significantly better than baseline(P =0.030, 0.017, 0.006 respectively). In the eyes with macular CME and subretinal fluid the mean BCVA was significantly improved at 3mo after SO removal compared with baseline(P =0.037).CONCLUSION: Decreased visual acuity in eyes filled with SO could be caused by macular complications due to SO. CME and subretinal fluid may resolve without any additional macular surgery after SO removal.

关键词： retinal detachment silicone oil macula

Traces of Defects in the Electronic Structure of Porous Ni—Ti Alloys

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Journal of Materials Science & Technology 2013年第4期29卷 344-348页

作者： O.M.Ozkendir E.Cengiz E.Tirasoglu mehmet Kaya I.H.karahan N.Orhan Tarsus Technical Faculty of Education Mersin UniversityTarsusTurkey Institute for Molecular Science UVSOR FacilityOkazaki 444-8585Japan Science Faculty Department of PhysicsKaradeniz Technical UniversityTrabzonTurkey Vocational School Adiyaman University.Adiyaman 02040Turkey Department of Mechanical Engineering Texas A&M UniversityCollege StationTX 77843USA Faculty of Arts and Sciences Department of PhysicsMustafa Kemal UniversityHatayTurkey Faculty of Technology Department of Metallurgy and Material EngineeringFirat UniversityElazigTurkey

The electronic structures of Ni-Ti shape-memory alloy samples were investigated by X-ray absorption fine structure （XAFS） spectroscopy both experimentally and theoretically. In the experimental section, the samples were measured at low temperature to determine the persistent traces of both preheating process and atomic concentration effects on the crystal and electronic structure by X-ray absorption near-edge structure （XANES） spectroscopy. As a second step, the extended-X-ray absorption fine structure （EXAFS） calculations, which are based on different choices of one electron potentials according to Ti coordinations by using the real space multiple scattering method FEFF 8.2 code, were performed. The crystallographic and electronic structures of the porous Ni-Ti alloys were tested at various temperatures ranging from 5 to 1323 K.

关键词： Electronic structure Porous Ni-Ti alloys Shape memory effect Transition metals

Fuzzy rule based seismic risk assessment of one-story precast industrial buildings

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Earthquake Engineering and Engineering Vibration 2019年第3期18卷 631-648页

作者： mehmet Palanci Istanbul Arel University Department of Civil Engineering

Effi cient tools capable of using uncertain data to produce fast and approximate results are more practical in rapid decision-making applications when compared to conventional methods. From this point of view, this study introduces a risk assessment model for one-story precast industrial buildings by fuzzy logic which builds a bridge between uncertainty and precision. The input, output and relations of the fuzzy based risk assessment model (FBRAM) were determined by reference buildings. The Monte Carlo simulation method was used to handle uncertainties associated with the structural characteristics of the reference buildings. Section dimension, longitudinal reinforcement ratio, column height related to building elevation, confi nement ratio and seismic hazard are regarded as input and the plastic demand ratio is considered as the output parameter by the mathematical formulation of strength and deformation capacity of the buildings. The supervised learning method was used to determine the membership function of fuzzy sets. Fuzzy rules of FBRAM were constructed from Monte Carlo simulation by mapping of inputs and output. FBRAM was evaluated by a group of simulated buildings and two existing precast industrial buildings. Comparisons have shown signifi cant agreement with analytical model results in both cases. Consequently, it is anticipated that the proposed model can be used for the seismic risk mitigation of precast buildings.

关键词： fuzzy logic supervised learning precast buildings risk assessment Monte Carlo simulation

Primary hepatic carcinosarcoma

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Hepatobiliary & Pancreatic Diseases International 2011年第1期10卷 101-103页

作者： mehmet elikbilek Kemal Deniz Edip Torun Tarιk Artιs Ersin zaslan kkes brahim karahan Tahir Ercan Patιroglu mer zbakιr Department of Gastroenterology Erciyes UniversityMedical School Department of Pathology Erciyes UniversityMedical School Department of Surgery Erciyes UniversityMedical School Department of Internal Medicine Erciyes UniversityMedical School

BACKGROUND:Primary hepatic carcinosarcoma is a rare malignant tumor containing an intimate mixture of carci- nomatous and sarcomatous *** on risk factors, epidemiology,and pathogenesis of the tumor as well as the experience in its treatment are limited. METHOD:We present a case of primary carcinosarcoma of the liver in a 69-year-old man who complained of right hypochondrial pain and weight loss for two months. RESULTS:Magnetic resonance imaging revealed a 14×12 cm mass in segments 7-8 and 4 of the liver with vena hepatica *** ultrasonography-guided biopsy showed osteoid tissue without osteoblastic *** structures accompanied the osteoid *** patient underwent surgery after a diagnosis of *** frozen sections revealed a carcinosarcoma associated with an osteosarcoma and cholangiocellular carcinoma components. CONCLUSIONS:Preoperative diagnosis of this rare primary hepatic malignant tumor may be difficult by biopsy owing to intratumoral *** mature areas of the osteosarcomatous component may lead to misdiagnosis of metaplastic bone *** features of this rare entity are discussed.

关键词： carcinosarcoma liver neoplasms osteosarcoma cholangiocarcinoma

Two-and three-dimensional stability analysis of underground storage caverns in soft rock(Cappadocia, Turkey) by finite element method

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Journal of Mountain Science 2022年第4期19卷 1182-1202页

作者： SARI mehmet Department of Mining Engineering Aksaray UniversityAksaray 68100Turkey

Engineering design in soft rocks and its stability analysis exerts many challenges to rock engineers. Many engineering works in Turkey’s Cappadocia region must face and tackle the existing sites covered by the soft rocks. This study is aimed to examine the stability condition of a typical underground storage cavern(USC) excavated in a soft rock in this region. For this purpose, two-and threedimensional stability analyses of the USCs were performed using the finite element method(FEM).Because of the inherent difficulty in characterizing soft/weak rock masses in the region using traditional classification systems, the stability of a typical USC was evaluated by representing the rock mass condition with two distinct scenarios in FEM *** these structures were unstable according to the 2D analysis conducted in RS2 software in the worstcase scenario, they were stable in the 3D analysis using RS3 software in both scenarios. Besides,feasible cover depths were examined to assess their possible effects on the factor of safety and deformation measurements. It was found that 15 m seems to be an optimal depth for excavating a typical USC in the soft rocks exposed in the region. The 3D FEM results provide valuable information to optimize the future planning and preliminary design of USCs.

关键词： Underground storage cavern Numerical modeling Soft rock FEM analysis Rock mass failure

Evaluating rockfalls at a historical settlement in the Ihlara Valley(Cappadocia, Turkey) using kinematic, numerical, 2D trajectory, and risk rating methods

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Journal of Mountain Science 2022年第12期19卷 3346-3369页

作者： SARI mehmet Department of Mining Engineering Aksaray UniversityAksaray68100Turkey

Rockfalls are one of the most dangerous natural events in hilly terrains, and they substantially threaten residential areas and transport corridors in these environments. This study is aimed to analyze the risk of rockfall from a slope to nearby houses in a historical settlement with past rockfall histories. It contains numerous applications to study rockfall danger from different points of view(e.g., kinematics,numerical stability analysis, risk assessment, 2D trajectory). The rockfall kinematics revealed the statistics for different structurally controlled failure modes among the surveyed slope discontinuities,especially wedge type and block toppling were the most significant ones. Finite element analysis showed that the slope was stable under the natural condition with a safety factor of 2.19. The rockfall risk rating system calculated a medium risk for the houses downstream. Based on the field measurements, a possible rockfall profile was determined and located as an input in the 2D rockfall trajectory program. The rigid-body impact model runs utilized various shapes and sizes of blocks to simulate the rockfall events realistically. According to the 2D trajectory model results, there was no rockfall danger for the investigated downslope houses. The study showed the importance of using different analysis techniques to solve rockfall risk in protected areas based on scientific and rational approaches.

关键词： Belisirma village Cappadocia region Rockfall kinematics 2D rockfall trajectory analysis Rockfall risk rating system FEM modeling

Analytical and approximate solutions of(2+1)-dimensional time-fractional Burgers-Kadomtsev-Petviashvili equation

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Communications in Theoretical Physics 2020年第5期72卷 21-31页

作者： mehmet Senol Department of Mathematics Nevsehir Haci Bektas Veli UniversityNevsehirTurkey

In this paper,we applied the sub-equation method to obtain a new exact solution set for the extended version of the time-fractional Kadomtsev-Petviashvili equation,namely Burgers-Kadomtsev-Petviashvili equation(Burgers-K-P)that arises in shallow water ***,using the residual power series method(RPSM),approximate solutions of the equation were obtained with the help of the Mathematica symbolic computation *** also presented a few graphical illustrations for some *** fractional derivatives were considered in the conformable *** of the obtained solutions were replaced back in the governing equation to check and ensure the reliability of the *** numerical outcomes confirmed that both methods are simple,robust and effective to achieve exact and approximate solutions of nonlinear fractional differential equations.

关键词： fractional partial differential equations Burgers-Kadomtsev-Petviashvili equation conformable fractional derivative sub-equation method residual power series method