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Wear of metallic surfaces after total knee arthroplasty is uncommon. In this case, we report a catastrophic failure of the knee prosthesis in a 60-year-old male patient who had undergone total knee prosthesis 7 years prior to his admission to our clinic. Genu recurvatum was observed in the affected knee. Surgical exploration of the knee showed wear of the polyethylene insert accompanied by metallic tibial component abrasion of the posterior-cruciate-retaining total knee prosthesis (Maxim, Biomet, Warsaw, IN, USA). Single-stage revision was performed, and a new total knee prosthesis was implanted (Legion, Smith & Nephew, Memphis, TN, USA). Postoperative examination showed improved stability and correction of recurvatum of the affected knee and follow-up examination showed improved weight bearing ability and better overall functional outcome.

Hybrid nanofluids have been known to provide perceptibly increased heat transfer characteristics over conventional fluid, and so have been experimentally applied to solar collector applications. Recently, attention has grown towards three-particle hybrid nanocomposites, to investigate their increased thermophysical properties for heat transfer applications. This study numerically investigates the practical application of CuO-MgO-TiO2 ternary nanofluids in a photovoltaic thermal (PV/T) collector. The proposed model explores the effect of volume fraction, solar irradiation, and mass flow rate on the performance of the collector system. The result showed an improved electrical efficiency of 13.54%. 58.38% and 15.68% thermal efficiency and energy efficiency respectively were also gotten, calculated at an optimum volume fraction of 0.01. The maximum cell temperature drop was 8.24 °C measured at a mass flow rate of 0.1 kg s−1. The study also concludes that a maximum increase of 11.14% of the total PV/T system was achieved by the use of ternary nanofluid. The study also investigated the pressure drop and pumping power of the PV/T collector with and without nanofluid. The result showed that a lower pressure drop and pumping power for the CuO–MgO–TiO2 ternary nanofluid which makes it more desirable as compared to the Al2O3–ZnO hybrid nanofluid. Finally, it is shown that the performance of the PV/T collector depends highly on the volume fraction of the ternary nanofluid.

The present paper aims to investigate the coupled nonlinear Schrodinger equation (NLSE) in magneto-optic waveguides having anti-cubic (AC) law nonlinearity. The solitons secured to magneto-optic waveguides with AC law nonlinearity are extremely useful to fiber-optic transmission technology. Three constructive techniques, namely, the (G'/G)-expansion method, the modified simple equation method (MSEM), and the extended tanh-function method are utilized to find the exact soliton solutions of this model. Consequently, dark, singular and combined dark-singular soliton solutions are obtained. The behaviours of soliton solutions are presented by 3D and 2D plots.

Objective: Chiari malformations (CMs) are a heterogeneous group of disorders defined by anatomic anomalies of the cerebellum, brainstem, and craniovertebral junction (CVJ). The aims of this study a...

In this paper, performance analysis of three port full bridge converter based hybrid photovoltaic (PV)/battery management system is explained. The overall control system of the three port full bridge converter based PV/battery management system is created and simulated using MATLAB. Maximum power point tracking of solar PV system is controlled by perturb and observe method. Load regulation of PV/ battery management system is controlled by phase shift pulsewidth modulation technique. The system is tested for various real time operating conditions of the power system such as variation of PV panel voltage, change of battery voltage, and change of load power. The experimental verification also is carried out for developed system. Finally, simulation result and experimental result are compared for the developed system.

Introduction. Parkinson's disease patients with impulse control disorders and dopamine dysregulation syndrome is increasingly recognized. There are reports that such disorders can sometimes be improved by using deep brain stimulation, but sometimes they can get worse. Case report. Our patient was a 30-year-old man with Parkinson's disease since the age of 23. The patient had motor fluctuations on the right with marked bradykinesia, bradymimia and rigidities in the off-periods. The patient's paraphilia and sexual indiscretions against women were apparent in the on-periods. The patient's eating habits were also changed. The patient underwent subthalamic nucleus-deep brain stimulation (STNDBS). Significant improvements were seen in the motor and behavior signs of the patient after this procedure had been performed. Conclusion. STN-DBS may be a reasonable option in patients with Parkinson's disease when unwanted dopaminergic side effects occur, and motor disorders and impulse control disorders cannot be improved with drugs.

Ternary nanofluids are a new type of fluids with three nanoparticles dispersed in a base fluid, and they have been experimentally shown to have improved thermophysical and rheological properties as compared to conventional or hybrid nanofluids. This study presents a numerical computation of investigating the performance of Photovoltaic/thermal collectors by utilizing Al2O3-ZnO-Fe3O4/water ternary nanofluid. The preparation of the nanofluid was done using a two-step method and analyzed for stability using Zeta potential analysis. The effect of the mixture ratio of the nanofluid on the thermal and electrical efficiency of the Photovoltaic/thermal system is investigated. The price-performance factor of the ternary nanofluid is firstly computed to determine the optimum volume concentration for practical application. This study also investigates the effect of nanofluid mass flow rate, volume fraction, mixture ratio and solar irradiation on the Photovoltaic/thermal system. From an economic standpoint, the system was estimated using the Price-performance factor and results showed that the 0.5 vol% Al2O3-ZnO-Fe3O4 ternary hybrid nanofluid was most suitable for laminar flow and turbulent flow regimes. The optimum electrical and thermal efficiency measured in this study was 13.75% and 59.38% respectively. This study also recorded an optimum cell temperature reduction of 8.81 °C. The mixture ratio measured for optimum PV/T performance was 0.33. The maximum exergy efficiency and PV/T total exergy efficiency recorded are 1.53% and 14.77%. The ternary nanofluid based PV/T system saved 19948.04 kgCO2 annually, as compared to 18719.88 kgCO2 when water was used as heat transfer fluid. The payback period was calculated to be 2.63 years for the ternary hybrid nanofluid based PV/T system.

Objectives Chiari malformations (CMs) are a group of disorders defined by anatomic anomalies of the cerebellum, brainstem, and craniovertebral junction (CVJ). In this study, we aimed to investigate morphometry of posterior fossa and CVJ in subtypes of CM and in control group, and to bring up a matter a correlation with demographic data and subtypes of CM. Patients and Methods The study group included patients managed for CM between 2012 and 2016 and control group. Radiological evaluation was studied by special programs and formulas. Intracranial volumes and morphometric datas of posterior fossa and CVJ were recorded retrospectively. Results Of the 141 patients, 91 had CM and 50 were control group participants. Mean age was 34.75. Patients were classified as CM-0 (n:10), CM-1 (n:45), CM-1.5 (n:21), CM-2 (n:15). There were statistically significance between Chiari subtypes by syringomyelia (SM) presence (p ˂ 0.01), SM localization (p ˂ 0.01), posterior fossa volume (PFV) (p ˂ 0.01), length of clivus (LoC) and length of subocciput (LoSO) (p ˂ 0.01 for both), angle between clivus and subocciput (C-SO angle) (p ˂ 0.01), and clivo-dental angle (C–D angle) (p ˂ 0.01). Conclusion On morphometric comparison of CM subtypes we concluded that etiological differences lead to morphological differences. CM-2 has remarkable differences from both other subtypes and the control group.

Objective: Radiologically Isolated Syndrome (RIS) has become a popular subject recently with quite a number of follow-up and other clinical studies being done. A consensus on the approach to the patient with RIS is being tried to be established. The aim of our study was to assess the role of visual evoked potential (VEP) and somatosensory evoked potential (SEP) as a guiding factor for the conversion from Radiologically Isolated Syndrome (RIS) to definite Multiple Sclerosis (MS). Material and methods: 49 RIS patients who were referred to GATA Haydarpasa Training Hospital Neurology Department between 2011-2015. All of the patients fullfillied the 2009 Okuda criteria for RIS and other differential diagnosis were excluded accordingly. VEP and SEP examinations made during the pre-MS RIS period were scanned retrospectively. For the VEP examination, the P100 latency and amplitudes, for the SEP examination, the P40 latency and amplitude was analysed. Results: 49 patients were included in this study, the mean time of follow-up was 21,8 months. 63% of patients were female, while 37% were male. The mean age was 31,2 years. Among the four patients with abnormal SEPs, MS developed in three of them (75%) over time. This is statistically significant (p = 0.011). VEP and/or SEP was abnormal in 8 patients and MS developed in 4 (50%) of those (p=0.017). The following factors have a positive statistically significant correlation with conversion to MS: Presence of active plaques (r=0.461, p

Degeneration of IVD is a progressive and irreversible process and can be evaluated with immunohistochemical examination or radiological grading. MMPs are a family of proteolytic enzymes and involved in the degradation of the matrix components of the IVD. We aimed to compare MMP-1, -2, -3, and -9 expressions with demographic features, visual analogue scale (VAS), Oswestry Disability Index (ODI) and radiological (MRI) grades. The study involved 60 participants. We recorded data about age, complaint, radiological imaging, expression levels of MMP-1, -2, -3, and -9, ODI and VAS for back pain retrospectively. Intervertebral disc degeneration was graded on a 0-5 scale according to the Pfirrmann classification. As a result of the study, the median age was 52.09±12.74years. There were statistical significances between age and MMP-1, and MMP-2. There was a close correlation between grade and MMP-9. We found correlation between the VAS and the MMP-9 expression. In addition, there was relationship between expression of MMP-2 and MMP-1, MMP-3, MMP-9. In conclusion, the expressions of MMP-1 and -2 are increased with aging. There was no relationship between radiological evaluation of IVDD and aging. Increased expression of MMPs affected IVDD positively. The relationship with MMPs is not explained. This study adds to our understanding of the interaction between MMPs and IVDD.

Background: Prolongation of the peak and the end of T wave (Tp-e) has been reported to be associated with ventricular arrhythmias. Tp-e/QT ratio and Tp-e/QTc ratio are used as an index of ventricular arrhythmogenesis. An increased incidence of ventricular arrhythmias has been reported in patients with obstructive sleep apnea (OSA). The aim of this study was to assess ventricular repolarization in patients with OSA by using Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio. Methods: We have studied 72 patients who underwent overnight polysomnography (PSG) between the years 2010–2011 at our institution. Patients with moderate and severe OSA (23 patients; mean age: 45±10), according to the apnea-hypopnea index, constituted the study group. Patients with normal PSG (23 patients; mean age: 42±11) were used as the control group. In all patients, Tp-e interval, Tp-e/QT ratio, Tp-e/QTc ratio, as well as some other electrocardiogram intervals were measured. Independent samples t-tests were used for comparison of continuous and categorical variables and correlations were calculated by Spearman rank correlation. Results: Although QT and QTc intervals were not different between the groups, mean Tp-e interval (81.6±11.1 msn; 63.9±7.3 msn; respectively; P < 0.001), Tp-e/QT ratio (0.21±0.03; 0.17±0.02; respectively; P < 0.001), and Tp-e/QTc ratio (0.20±0.03; 0.16±0.02; respectively; P < 0.001) were prolonged in the study group compared to the control group. Correlation analysis showed a significant positive correlation between the presence of moderate and severe OSA and Tp-e interval (r = 0.72; P < 0.001), Tpe/QT ratio (r = 0.70; P < 0.001), and Tp-e/QTc ratio (r = 0.70; P < 0.001). Conclusions: Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio are prolonged in patients with moderate and severe OSA patients. There is a positive correlation between the presence of OSA and Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio. (PACE 2012; 35:966–972)

Aim To investigate elastic characteristics of the aorta in patientswith epilepsy.Methods Seventy five patients with a diagnosis of epilepsy through clinical and EEG findings and age and sex matched, 50 healthy controls were included. Systolic and diastolic blood pressures plus systolic and diastolic diameter of the aortic root was measured. Aortic strain (AS) and aortic distensibility (AD) and aortic distensibility index (BSI) were calculated. Results The average age of the epilepsy group was 23.8.8 ± 8.2 years, and of the control group it was 24.1± 6.2 years (p>0.05). AS and AD were lower in the epileptic group while the aortic stiffness index was higher (10.4± 4.2 vs 16.9±0.2, p: 0.001, for AS; 8.7± 4.0 vs 17.2±0.1, p: 0.001, for AD and 20.1±0.1 vs 3.5±1.2, p: 0.001 for BSI). Conclusion Elastic characteristics of the aorta change in epileptic patients, with a decrease of the distensibility of the aorta and an increaseof the stiffness. After this preliminary study, new controlledstudies are needed.

AIM In this study, our aim was to examine if matrix metalloproteinase expressions (MMP-1, MMP-2, MMP-3) in patients operated with a lumbar disc hernia diagnosis are different in terms of clinical and neuroradiological findings. MATERIAL AND METHODS The study included 80 patients treated with micro discectomy for lumbar disc hernia. Degeneration was scored via magnetic resonance (MR) images. MMP-1, MMP-2, and MMP-3 antibodies were used for immunohistochemical evaluation of degenerated disc materials. MMP expressions were compared between primary and recurrent cases, and correlation analysis was conducted. RESULTS Discectomy material showed higher expression of MMP-1 and MMP-3 in cases of recurrent lumbar disc herniation than in primary herniation. There was no significant relationship between MMP expression and MR degeneration score. CONCLUSION MMP-1 and MMP-3 expressions were significantly higher in recurrent cases in terms of magnetic resonance degeneration score. We assume that the higher co-expression of MMP-1 and MMP-3 might be used in targeted treatment regiemens in patients with recurrent LDH.

Background and purpose. We retrospectively researched 119 patients with buttock level traumatic injury to sciatic nerves and 42 cases of sciatic nerve injuries due to intramuscular injections were observed among them. Our aim was finding out the post-operative outcomes of early intervention and describing a timing schedule for surgical intervention. Methods. Between 1984 and 2004 a total of 73 patients were operated on to explore the nerve lesion. These injuries consisted of post-injection injury, hip fracture/dislocation, contusion, compression, gunshot wound, hip arthroplasty and laceration. Our study took into account 29 cases operated because of injection injury. The most common presenting symptom was pain, which often masked underlying loss of function. Findings at operation were analysed according to the type of sciatic nerve damaged following intramuscular injection, the nature of this injury and the referring speciality. Some of the more common causal operations and procedures are discussed. Preventive measures are listed, and early diagnosis and treatment are recommended. The aim of the operation was to establish the diagnosis, to resolve pain and to improve function by epineural or interfasciculary neurolysis. Results. We analysed the findings at operation according to the nature of the injury and the procedures which the patients underwent. Seven patients (24.1%) had an excellent outcome, 14 patients (48.2%) had good outcome and 4 patients (13.8%) had fair outcome. The other four patients (13.8%) had poor outcome. No patients suffered from additional postoperative neurological deficits or from worsening of pre-operative deficits. Conclusions. Based on our experiences, we recommend measures by which the morbidity rate of these injuries may be reduced. We stress, however, that if the clinical evidence points to transection of a nerve, that nerve may be explored without waiting for electrophysiological confirmation. Delay in recognition and therefore treatment was a cause of litigation, and contributed to the poor outcome in many cases.