• Annals of Clinical Neurophysiology
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• v.16 no.1
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• pp.32-34
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• 2014

A 77-year-old man developed acute vertigo and unsteady gait. Neurological examination revealed spontaneous left-beating nystagmus in the primary position. He fell to the left when walking without support. Magnetic resonance imaging showed an acute infarction involving the right parieto-temporal lobe. Although the vertigo and unsteady gait are most often associated with vestibular disorders involving the infratentorial structures, those may occur in cerebral infarction of the parieto-temporal lobe.

• Journal of Veterinary Clinics
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• v.34 no.2
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• pp.94-97
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• 2017

A 10-year-old male Schnauzer dog presented with a 1-week history of ataxia, right-sided hemiparesis, and right-sided head tilt. On the basis of magnetic resonance imaging (MRI) with neurological examination and cerebrospinal fluid analysis results, a primary brain tumor was suspected. Therapy with imatinib mesylate plus hydroxyurea for 7 weeks was not effective and clinical signs worsened. Chemotherapy was then changed to lomustine plus hydroxyurea. Although the existing clinical signs continued, they did not deteriorate. No change in mass size was observed in subsequent MRI. The subject suddenly died from dyspnea 388 days after initial presentation. In this case, choroid plexus papilloma was definitively diagnosed based on histopathological findings.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.11
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• pp.1664-1671
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• 2004

It is necessary to have a model that describes the feature of the knee Joint with a sufficient accuracy. Koreans, however, do not have their own knee joint model to be used in the total knee replacement arthroplasty. They have to use European or American models which do not match Koreans. Three-dimensional visualization techniques are found to be useful in a wide range of medical applications. Three-dimensional imaging studies such as CT(computed tomography) and MRI(magnetic resonance image) provide the primary source of patient-specific data. Three-dimensional knee joint models were constructed by image processing of the CT data of 10 subjects. Using the constructed model, the dimensions of Korean knee joint were measured. And this study proposed a three-dimensional model and data, which can be helpful to develop Korean knee implants and to analyze knee joint movements.

• Journal of Korean Neurosurgical Society
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• v.55 no.4
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• pp.205-207
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• 2014

Meningioma is a common primary tumor of central nervous system. However, extracranial extension of the intracranial meningioma is unusual, and mostly accompanied the osteolytic change of the skull. We herein describe an atypical meningioma having extracranial extension with hyperostotic change of the skull. The patient was a 72-year-old woman who presented a large mass in the right frontal scalp and left hemiparesis. Brain magnetic resonance imaging and computed tomography scans revealed an intracranial mass, diffuse meningeal thickening, hyperostotic change of the skull with focal extension into the right frontal scalp. She underwent total removal of extracranial tumor, bifrontal craniectomy, and partial removal of intracranial tumor followed by cranioplasty. Tumor pathology was confirmed as atypical meningioma, and she received adjuvant radiotherapy. In this report, we present and discuss a meningioma en plaque of atypical histopathology having an extracranial extension with diffuse intracranial growth and hyperostotic change of the skull.

• Journal of Yeungnam Medical Science
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• v.31 no.2
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• pp.152-156
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• 2014

We report on a patient who showed visual recovery following bilateral occipital lobe infarct, as evaluated by follow up functional magnetic resonance imaging (fMRI) and diffusion tensor tractography (DTT). A 56-year-old female patient exhibited severe visual impairment since onset of the cerebral infarct in the bilateral occipital lobes. The patient complained that she could not see anything, although the central part of the visual field remained dimly at 1 week after onset. However, her visual function has shown improvement with time. As a result, at 5 weeks after onset, she notified that her visual field and visual acuity had improved. fMRI and DTT were acquired at 1 week and 4 weeks after onset, using a 1.5-T Philips Gyroscan Intera. The fiber number of left optic radiation (OR) increased from 257 (1-week) to 353 (4-week), although the fiber numbers for right OR were similar. No activation in the occipital lobe was observed on 1-week fMRI. By contrast, activation of the visual cortex, including the bilateral primary visual cortex, was observed on 4-week fMRI. We demonstrated visual recovery in this patient in terms of the changes observed on DTT and fMRI. It appears that the recovery of the left OR was attributed more to resolution of local factors, such as peri-infarct edema, than brain plasticity.

• Journal of Power Electronics
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• v.19 no.3
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• pp.827-834
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• 2019

Wireless power transfer via coupled magnetic resonances has been a hot research topic in recent years. In addition, the number of related devices has also been increasing. However, reverse signals transfer is often required in addition to wireless power transfer. The structure of the circuit for a wireless power transfer system via coupled magnetic resonances is analyzed. The advantages and disadvantages of both parallel compensation and series compensation are listed. Then the compensation characteristics of the inductor, capacitor and resistor were studied and an appropriate compensation method was selected. The reverse signals can be transferred by controlling the compensation of the resistor. In addition, it can be demodulated by extracting the change of the primary current. A 3.3 MHz resonant frequency with a 100 kHz reverse signals transfer system platform was established in the laboratory. Experimental results demonstrate that wireless power and reverse signals can be transferred synchronously.

• Structural Engineering and Mechanics
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• v.69 no.2
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• pp.131-143
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• 2019

In this study, the nonlinear vibration analysis of the composite nanoplate is studied. The composite nanoplate is fabricated by the functional graded (FG) core and lipid face sheets. The material properties in the FG core vary in three directions. The Kelvin-Voigt model is used to study the viscoelastic effect of the lipid layers. By using the Von-Karman assumptions, the nonlinear differential equation of the vibration analysis of the composite nanoplate is obtained. The foundation of the system is modeled by the nonlinear Pasternak foundation. The Bubnov-Galerkin method and the multiple scale method are used to solve the nonlinear differential equation of the composite nanoplate. The free and force vibration analysis of the composite nanoplate are studied. A comparison between the presented results and the reported results is done and good achievement is obtained. The reported results are verified by the results which are obtained by the Runge-Kutta method. The effects of different parameters on the nonlinear vibration frequencies, the primary, the super harmonic and subharmonic resonance cases are investigated. This work will be useful to design the nanosensors with high biocompatibility.

• Archives of Craniofacial Surgery
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• v.23 no.3
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• pp.125-129
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• 2022

Most malignant lymphomas of the head and neck region are non-Hodgkin lymphomas (NHL), and diffuse large B-cell lymphoma is the most common subtype. The prevalence of malignant lymphoma among parotid tumors is low, approximately 1% to 4%. The most common symptom of parotid lymphoma is a unilateral, non-tender, firm mass that slowly grows in size over time. As its clinical manifestations are nonspecific, a comprehensive assessment is required for an accurate diagnosis. The initial work-up includes imaging tools, such as computed tomography and magnetic resonance imaging. However, NHL of the parotid gland is difficult to distinguish from other types of benign tumors prior to biopsy; histopathological evaluation and subsequent immunohistochemical staining are needed for the final diagnosis. Once a definitive diagnosis is established, patients should be referred to an oncologist for staging. Treatment is mainly based on systemic chemotherapy, whereas radiotherapy is indicated for certain cases. Here, we report the case of a 53-year-old man who presented with a progressively enlarging mass in the right parotid area, which was later diagnosed as malignant lymphoma of the parotid gland after superficial parotidectomy.

• Journal of Astronomy and Space Sciences
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• v.39 no.2
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• pp.35-42
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• 2022

During their respective missions, the spacecraft Voyager and Cassini measured several Saturn magnetosphere parameters at different radial distances. As a result of information gathered throughout the journey, Voyager 1 discovered hot and cold electron distribution components, number density, and energy in the 6-18 Rs range. Observations made by Voyager of intensity fluctuations in the 20-30 keV range show electrons are situated in the resonance spectrum's high energy tail. Plasma waves in the magnetosphere can be used to locate Saturn's inner magnetosphere's plasma clusters, which are controlled by Saturn's spin. Electromagnetic electron cyclotron (EMEC) wave ring distribution function has been investigated. Kinetic and linear approaches have been used to study electromagnetic cyclotron (EMEC) wave propagation. EMEC waves' stability can be assessed by analyzing the dispersion relation's effect on the ring distribution function. The primary goal of this study is to determine the impact of the magnetosphere parameters which is observed by Cassini. The magnetosphere of Saturn has also been observed. When the plasma parameters are increased as the distribution index, the growth/damping rate increases until the magnetic field model affects the magnetic field at equator, as can be seen in the graphs. We discuss the outputs of our model in the context of measurements made in situ by the Cassini spacecraft.

• Journal of the Korean Orthopaedic Association
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• v.56 no.4
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• pp.346-350
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• 2021

A magnetic resonance imaging test was performed on a 56-year-old male patient, who visited with a one-month history of painless swelling at the popliteal area of the left knee. A popliteal cyst and non-calcified loose body in the cyst were identified. Synovial chondromatosis was diagnosed from a histology examination by excision and biopsy. This paper reports this case of extra-articular synovial chondromatosis of the knee with a review of the relevant literature.