Use of cone-beam computed tomography and three-dimensional modeling for assessment of anomalous pulp canal configuration: a case report

Alper Sinanoglu,Dilek Helvacioglu-Yigit,Ibrahim Mutlu 대한치과보존학회 2015 Restorative Dentistry & Endodontics Vol.40 No.2

Three-dimensional (3D) reconstruction of cone-beam computed tomography (CBCT) scans appears to be a valuable method for assessing pulp canal configuration. The aim of this report is to describe endodontic treatment of a mandibular second premolar with aberrant pulp canal morphology detected by CBCT and confirmed by 3D modeling. An accessory canal was suspected during endodontic treatment of the mandibular left second premolar in a 21 year old woman with a chief complaint of pulsating pain. Axial cross-sectional CBCT scans revealed that the pulp canal divided into mesiobuccal, lingual, and buccal canals in the middle third and ended as four separate foramina. 3D modeling confirmed the anomalous configuration of the fused root with a deep lingual groove. Endodontic treatment of the tooth was completed in two appointments. The root canals were obturated using lateral compaction of gutta-percha and root canal sealer. The tooth remained asymptomatic and did not develop periapical pathology until 12 months postoperatively. CBCT and 3D modeling enable preoperative evaluation of aberrant root canal systems and facilitate endodontic treatment.

Letters to the Editor : Bupropion-Induced Erythema Multiforme

( Alper Evrensel ),( Mehmet Emin Ceylan ) 대한피부과학회 2015 Annals of Dermatology Vol.27 No.3

Visual Culture Questionnaire

Alpers,Svetlana,Emily Apter,Carol Armstrong,Susan Buck-Morss,Tom Conley,Jonathan Crary,Thomas Crow,Tome Gunning,Michael Ann Holly,Martin Jay,Thomas Docosta Kaumann,Silvia Kolbowski,Sylvia Lavin,Stephe The MIT Press 1996 October Vol.77 No.-

Performance and duration differences between online and paper-pencil tests

Alper Bayazit,Petek As¸kar 서울대학교 교육연구소 2012 Asia Pacific Education Review Vol.13 No.2

Digital technologies have been used for measurement purposes and whether the test medium influences the user is an important issue. The aim of this study is to investigate students' performances and duration differences between online and paper-pencil tests. An online testing tool was developed and administered in order to determine the differences between the traditional paper-pencil tests and online tests concerning students' performances and the duration on tests. This tool enables to add questions that utilize an online database and which are in the form of multiple choice (with 5 or 4 options), true-false, matching, filling in the blanks, with multiple answers, with short answers, with long answers, and it also enables to prepare tests and to turn them into paper-pencil test mode. Performance test was applied with both online and paper-pencil modes on junior students at one of the universities in Turkey. Besides, the online testing tool developed within the context of the study was evaluated by instructors with respect to usability, relevance to the purpose and design. Instructor and student questionnaires are developed to determine the opinions on the online testing tool and online tests. Results showed that there was no significant differences between the performances on online and paper-pencil tests. On the other hand, the time they spent on the online test has been longer than the time they spent on paper-pencil test. Students found the online testing tool easy to use and stated that online test medium is more comfortable than paper-pencil tests. However, they complained about external noises, tiredness, and focusing problems regarding the online examination mediums. Generally, instructors have also appreciated the online testing tool's design and they agree on the fact that it serves for its purposes.

When is CPR Futile?

Alpers, Ann,Lo, Bernard MediMedia Korea 1995 JAMA-Korea Vol.10 No.5

An investigation of cointegration between energy consumption and economic growth: Dynamic evidence from East Asian countries

ALPER ASLAN,HAKAN KUM 연세대학교 동서문제연구원 2010 Global economic review Vol.39 No.4

This paper aims to investigate the relationship between energy consumption and economic growth for 11 East Asian countries over the period 1971 2005 by taking into account their strong relationships. Based on fully modified ordinary least squares (FMOLS) and dynamic OLS (DOLS) approaches, while there exists a strong relation running from economic growth to energy consumption, it is observed that the strong relationship which runs from energy consumption to economic growth is overwhelmingly rejected for all cases except Indonesia and the Philippines. Moreover the inverse relation between two variables is observed for these two countries.

Small Size Autograft versus Large Size Allograft in Anterior Cruciate Ligament Reconstruction

Alper Kurtoğlu,Betül Başar,Gökhan Başar,Ömer Gezginaslan,Hakan Başar 대한정형외과학회 2021 Clinics in Orthopedic Surgery Vol.13 No.1

Background: A small autograft diameter negatively affects functional outcomes, knee stability, and the risk of rerupture after anterior cruciate ligament (ACL) reconstruction, whereas the strength of allograft decreases over time. Therefore, it is not clear whether the use of smaller autografts or the use of larger allografts in ACL yields better results. The aim of this study was to compare the outcome of smaller autografts and larger allografts for ACL reconstruction. Methods: Fifty-one patients who underwent ACL reconstruction with hamstring tendon autografts (size ≤ 8 mm) and 21 patients who underwent ACL reconstruction with allografts (size ≥ 10 mm) were included in our study. All patients underwent the same aggressive early postoperative rehabilitation program. There were no significant differences between the autograft and allograft groups regarding the preoperative patient age, sex, time from injury to surgery, and average follow-up time. Results: The mean diameter of the 4-stranded hamstring tendon grafts used as autografts was 7.48 ± 0.33 mm and the mean diameter of the allografts was 10.76 ± 0.67 mm. According to specific tests for the ACL (anterior drawer, Lachman, and pivot shift) and clinical evaluation tests (Lysholm knee scoring scale and International Knee Documentation Committee questionnaire), the final follow-up results were significantly better than the preoperative status in both autograft and allograft ACL reconstruction groups. Therefore, there were no significant differences between the autograft and allograft groups preoperatively and at the final follow-up. Conclusions: The large size of the graft in ACL reconstruction has been reported to affect results positively. However, in our study, we could not find any significant differences between the smaller size autografts and larger size allografts in terms of inadequacy, rerupture, and final follow-up functional results. Although allografts were significantly larger than autografts, we did not have the positive effect of larger size grafts. Smaller size autografts were as effective as the larger size allografts.

Tectonic Geomorphology of the North Anatolian Fault Zone in the Lake Sapanca Basin (Eastern Marmara Region, Turkey)

Alper Gürbüz,Ömer Feyzi Gürer 한국지질과학협의회 2008 Geosciences Journal Vol.12 No.3

In this study the spatial variations of the Plio-Quaternary tectonic activity and deformation of different fault segments of the North Anatolian Fault Zone (NAFZ) in the eastern Marmara region around Lake Sapanca, are assessed using geomorphic, morphometric and bathymetric approaches. Lake Sapanca is an E-W-trending structure located in the zmit-Sapanca Corridor. This region is bounded to the north and to the south by the series of mountain ranges. Geomorphic and morphometric data provide evidence for variations between the two mountain front faults regarding levels of tectonic activity. These studies suggest a relatively high degree of tectonic activity along the Sapanca front in the south, in contrast with a low degree of tectonic activity along the E me front in the north of the study area. This pattern is also consistent with field evidence and seismic data of the study area. Bathymetric profiles of the lake show that the lake basin consists of different fault segments that slipped in the 1999 Kocaeli earthquake. All these data suggest that the zmit-Sapanca Corridor is an asymmetric pull-apart basin associated with displacement along the NAFZ in the Late Pliocene. Lake Sapanca also occurs as a pull-apart basin created by the cross-basin fault of the asymmetric pull-apart basin in the Middle Pleistocene.

Nonlinear Fiber Modeling of Steel-Concrete Partially Composite Beams with Channel Connectors

Alper Ozturk,Eray Baran,Cenk Tort 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.5

A simplified nonlinear fiber-based finite element model of steel-concrete partially composite beams utilizing channel type mechanical shear connectors is developed in OpenSees framework. The interaction between steel beam and concrete slab is accounted for by introducing nonlinear zero length elements and rigid links. The channel shear connector response used in numerical models is based on the previously obtained experimental response from pushout tests. Accuracy of the numerical models in predicting the response of beams is verified with the results of the previously conducted composite beam tests. The numerically predicted response agrees well with the experimental results over the entire range of load-deflection curves for both the fully composite and partially composite beams. The numerical models are also able to accurately predict the interface slip between steel beam and concrete slab when compared to the experimentally determined slip values, as well as the closed form slip predictions. Analysis results allowed the investigation of how the influence of steel and concrete damage is reflected on the overall loaddeflection response of composite beams.

Mechanical, Tensile Creep and Viscoelastic Properties of Thermoplastic Polyurethane/Polycarbonate Blends

Alper Kasgoz 한국섬유공학회 2021 Fibers and polymers Vol.22 No.2

This study investigated the morphological, mechanical and solid-state creep properties of thermoplasticpolyurethane/polycarbonate blends. Blend film samples were prepared via the solution-mixing method. The morphologicaland mechanical properties of the samples were investigated by scanning electron microscope (SEM) and universal testmachine. Solid-state creep tests were also performed by dynamic mechanic analyzer (DMA) under a stress value of 3 MPa atdifferent temperatures (30, 40, and 50 °C). Morphological observations indicated that the blend samples had a compatiblestructure due to the polar nature of PC and TPU. In the mechanical tests, it was found that the tensile modulus value improvedsignificantly by incorporation of PC, whereas the strain at break and toughness values reduced. Accordingly, the blendsample that contained PC at the rate of 10 % (wt.) showed a higher tensile modulus and lower toughness than neat TPU by2.85 and 0.56 times, respectively. In the creep strain analyses, the viscoelastic structure and long-term creep performance ofthe samples were analyzed by the Burger model, time-temperature superposition (TTS) approach and Findley model. Theexperimental values and the model predictions indicated that incorporation of PC into the TPU phase improved the creepresistance of TPU significantly. For example, the creep strain value of neat TPU could be reduced by 68 % and 98 % in therespective cases of the PC concentrations of 10 % (wt.) and 50 % (wt.). Finally, the experimental creep-recovery behavior ofthe samples was investigated, and the permanent strain values were determined by the Weibull Distribution Function (WDF).