Results of mitochondrial DNA sequence analysis in patients with clinically diagnosed leber’s hereditary optic neuropathy

Amaç: Klinik olarak Leber’in Herediter Optik Nöropatisi (LHON) tanısı alan hastalarda, kesin tanı ve genetik danışmanlık verilebilmesi için olası mitokondriyal DNA mutasyonlarının araştırılması. Gereç ve Yöntemler: 1982-2007 yılları arasında klinik olarak LHON tanısı alan 10 hasta kliniğimize davet edildi. Bütün olgularda rutin oftalmolojik muayeneden sonra alınan periferik venöz kan örneklerinden mitokondriyal DNA ayrıştırılarak, polimeraz zincir reaksiyonu (PCR) ve mitokondriyal DNA dizi analizi yapıldı. Bulgular: 6 hastadan birinde Homozigot mutant olarak m.11778G>A tek nükleotid değişimi (SNP) saptandı. 12 olgunun hepsinde m.14212C>T ve m.14580G>A SNP bulundu. 6 hastanın üçünde saptadığımız m.11719A>G SNP, aynı zamanda kontrol grubundaki 4 kişide de saptandı. 6 hastanın ikisinde m.3197T>C SNP ve bunlardan birinde ayrıca m.14258G>A SNP bulunurken bu SNP’lerin hiçbirine kontrol grubunda rastlanmadı. Sonuç: Klinik olarak LHON tanısı alan olgularımızdan sadece birinde bilinen mutasyonlardan biri saptanarak klinik tanı moleküler genetik olarak da desteklendi. m.14258G>A SNP’nin optik nöropatiye yol açabilecek olası mitokondriyal DNA mutasyonu olabileceği öngörüsündeyiz. Bu hipotezimizin kesinlik kazanabilmesi için olgu ve kontrol grubu sayısının arttırılarak çalışılmasına ihtiyaç vardır.Objective: To investigate possible mitochondrial DNA (mtDNA) mutations in patients with Leber’s hereditary optic neuropathy (LHON) in order to provide a precise diagnosis and genetic counseling. Material and Methods: Between 1982 and 2007, ten patients were clinically diagnosed with LHON and six of these patients agreed to be involved in this study. Six healthy individuals were also included as a control group. mtDNA was isolated from peripheral blood samples and polymerase chain reaction and mtDNA sequence analysis were performed. Results: In one of the six patients, a homoplasmic mutant m.11778G>A mutation was detected. All of the clinically diagnosed LHON patients and the control groups had the m.14212C>T and m.14580G>A single nucleotide polymorphisms (SNPs). The m.11719A>G SNP was detected in three of six patients and four of the controls. Two of the six patients had the m.3197T>C SNP and, in addition, the m.14258G>A SNP was found in one of these two patients, while neither of these mutations were present in the control group. Conclusion: The clinical diagnosis of LHON could be supported by molecular genetics only in one patient by the detection of one mutation. The m.3197T>C and m.14258G>A SNPs should be considered as potential mtDNA mutations due to the fact that they were detected in the patient group. These mutations should be investigated further in large case groups for suspected gene loci that could lead to optic neuropathy

Detecting prosthetic restorations using artificial intelligence on panoramic radiographs

Aim. This study applied a CNN (convolutional neural network) algorithm to detect prosthetic restorations on panoramic radiographs and to automatically detect these restorations using deep learning systems. Materials and Methods. This study collected a total of 5126 panoramic radiographs of adult patients. During model training, .bmp, .jpeg, and .png files for images and .txt files containing five different types of information are required for the labels. Herein, 10% of panoramic radiographs were used as a test dataset. Owing to labeling, 2988 crowns and 2969 bridges were formed in the dataset. Results. The mAP and mAR values were obtained when the confidence threshold was set at 0.1. TP, FP, FN, precision, recall, and F1 score values were obtained when the confidence threshold was 0.25. The YOLOv4 model demonstrated that accurate results could be obtained quickly. Bridge results were found to be more successful than crown results. Conclusion. The detection of prosthetic restorations with artificial intelligence on panoramic radiography, which is widely preferred in clinical applications, provides convenience to physicians in terms of diagnosis and time management

Assessment of the buckling strengths of composite plates impacted with different impact loads and points

This study has been designed to experimentally assess the changes of buckling loads of the E-glass fiber/epoxy composite laminates impacted at different impact energy levels. With the experiments conducted, the effects of the geometry parameters such as the ratio of impact point to the length of buckling (G = y/L) have been examined. According to the results of the experiments made, when the ratio of impact position is 0.2, buckling behaviors of the impacted specimens made at the energy levels of and under 10 J have been determined to be almost the same as the buckling behaviors of the non-impacted specimens. Generally, it has been found out that buckling behaviors of the impacted specimens made at the energies under such levels of energy as 15 J increase with the impact point ratio, and when the ratio is 0.2, buckling behaviors have been observed to be maximum. © 2010 The Author(s)

Kompozit disklerde termal gerilme analizi

Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.VI In this study, an elastic and elastic-plastic thermal stress analysis of an orthotropic aluminum metal matrix composite disc with a hole is investigated analytically for linear hardening material behavior. The aluminum composite disc which is reinforced curvilinearly by steel fibers is produced under hydraulic press. The mechanical properties of the composite disc are obtained by tests. A computer program is developed to calculate the thermal stresses under various temperatures. The various temperature distributions are chosen uniformly, parabolically, linearly increasing and decreasing from inner surface to outer surface. Elastic and elastic-plastic thermal stress distributions are obtained from inner surface to outer surface and they are presented in tables and figures. The elastic-plastic solution is performed for the plastic region expanded around the inner surface. As a result of this work the magnitude of the tangential stress component is higher than the magnitude of the radial stress component. And also the tangential stress component is compressive at the inner surface and tensile at the outer surface. The magnitude of the tangential residual stress component is the highest at the inner surface of the composite disc. GürkanALTANBu çalışmada, lineer sertleşen malzeme davranışı gösteren delikli ortotropik alüminyum metal matrisli kompozit bir diskin elastik-plastik termal gerilme analizi analitik olarak araştırıldı. Eğrisel çelik fiberlerle takviye edilen alüminyum kompozit disk hidrolik pres yardımı ile üretildi. Kompozit diskin mekanik özellikleri deneylerle belirlendi. Değişik sıcaklıklar altında termal gerilmeleri hesaplamak için bir bilgisayar programı geliştirildi. Diskin iç yüzeyinden dış yüzeyine doğru değişik sıcaklık dağılımları sabit, parabolik, lineer artan ve azalan olarak seçildi. İç yüzeyden dış yüzeye kadar olan bölgede elastik ve elastik-plastik termal gerilmelerin dağılımları hesaplandı ve sonuçlan tablolarda ve grafiklerde verildi. Plastik bölgenin iç yüzey etrafında genişlemesi durumu için elastik-plastik çözüm yapıldı. Yapılan bu çalışmanın sonucu olarak teğetsel gerilme bileşeninin değeri, radyal gerilme bileşenin değerinden büyük ve teğetsel gerilme bileşeni diskin iç yüzeylerinde bası, dış yüzeylerinde ise çeki gerilmesi durumundadır. Teğetsel artık gerilme bileşeninin değeri kompozit diskin iç yüzeyinde en büyük olarak oluşmaktadır. GürkanALTA

INVESTIGATION ON FLEXURAL BEHAVIORS OF I-SHAPED JOINTED COMPOSITE PLATES

In this study, the flexural behaviors of a composite plate jointed with I profile jointing element have been carried out experimentally and numerically. As a load type, four point flexural tests have been used in order to study performances of jointed composite plates under bending load. The effects of jointing geometry parameters ratio of the width of lock to width of semi-specimen (b/W), lock middle/end width to the width of lock (z/b) and the length of lock to the width of semi-specimen (h/2W) have been investigated. According to the investigation optimum jointing parameters have been found with the h/2w ratio of 0.5, b/w ratio of 0.5 and z/b ratio of 0.5. Abaqus 6.11 finite element program has been used in order to support the results obtained from the experiments. Damages have been mostly seen on jointing lock elements

Investigation of 3D printed Savonius rotor performance

In this study increasing the performance of Conventional Savonius wind rotor has been investigated by a 3D (three dimensional) printer which is one of the rapid prototyping techniques. For this purpose, some design changes have been introduced to increase the performance of conventional Savonius wind rotor. Here, 3D digital designing of Savonius wind rotors have been easily manufactured tangible as a physical model by a 3D printer. Experimental data concerning produced Savonius wind rotors have been acquired by using a wind tunnel. Some numerical data have been obtained from the CFD (Computational Fluid Dynamics) analysis carried out under the same conditions. The effects of the additional blade end design have been examined to obtain more torque increase on improved classical Savonius wind rotor. Furthermore, by means of introducing straight blade, the effects of the flow compression inside the blade have been reduced and rotor performance increased. Based on such optimizations, optimum additional design parameters have been designated as that (1/r) ratio is 0.3, (s/r) is 1, and (α) additional straight blade angle is 135°. It has been determined that power coefficient is increased at a ratio of around 20% together with all these design changes. © 2016 Elsevier Lt

Investigation of 3D printed Savonius rotor performance

In this study increasing the performance of Conventional Savonius wind rotor has been investigated by a 3D (three dimensional) printer which is one of the rapid prototyping techniques. For this purpose, some design changes have been introduced to increase the performance of conventional Savonius wind rotor. Here, 3D digital designing of Savonius wind rotors have been easily manufactured tangible as a physical model by a 3D printer. Experimental data concerning produced Savonius wind rotors have been acquired by using a wind tunnel. Some numerical data have been obtained from the CFD (Computational Fluid Dynamics) analysis carried out under the same conditions. The effects of the additional blade end design have been examined to obtain more torque increase on improved classical Savonius wind rotor. Furthermore, by means of introducing straight blade, the effects of the flow compression inside the blade have been reduced and rotor performance increased. Based on such optimizations, optimum additional design parameters have been designated as that (1/r) ratio is 0.3, (s/r) is 1, and (?) additional straight blade angle is 135°. It has been determined that power coefficient is increased at a ratio of around 20% together with all these design changes. © 2016 Elsevier Lt

Flexural behavior of 3D printed honeycomb sandwich structures with waste filler material

In this study, the flexural behavior of filled and unfilled honeycomb structures was experimentally examined. As filler material, waste materials of the furniture and marble industry were used. In this context, effects of the wastes of the furniture industry (i.e., pine sawdust) and of the marble industry (i.e., travertine powder) on the flexural behaviors of honeycomb structures were investigated by the three point flexural test. Honeycomb specimens were produced by using PLA plastic material in a 3D printer by rapid prototyping techniques. By changing cell sizes of the honeycomb structures used in the flexural tests, the relation between the waste filler materials and the cell size was also investigated. The flexural behavior of unfilled honeycomb specimens was at maximum for the specimens with small cell size. In the honeycomb structures filled with waste material, it was determined that the flexural loads of small cell sized specimens were decreased by approx. 10 % while the flexural loads of big cell sized specimens were increased by approx. 10 %. As a result, it was found that the flexural behavior of unfilled honeycomb structures with big cells which have low flexural behavior could be increased using waste filler material

An investigation on damage loads of mechanical butt joints in composite structures

With the advanced technology of our time comes an increased need for high quality materials. The conventional engineering materials are no longer adequate to suit the needs of the manufacturing process. Therefore, there is constant growth in the fields of the use of composite materials formed by the combination of two or more materials. Also various difficulties occur in the field where the composite materials are used. The systems which will be used both in the manufacturing process and in engineering designs are composed of more than one component. Therefore, the components should be jointed for the system designed. These joints are enabled with mechanical and bonding techniques. In this study, mechanical joints made with a joint lock having I profile have been recommended for use instead of the bonding technique in the butt joint of the composite plates. Load-carrying capacities of the locks of different dimensions formed with the exchange of basic geometric parameters that characterize I profile joint lock and its effects on the first damage have been analyzed experimentally and numerically. Determining the optimal joint with the best strength has also been conducted. The composite structure has been prevented from complete damage by the determination of the initial damage that may occur on I profile joint lock. Thus, the lifespan of the composite structure has been increased with the exchange of the lock component. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav