• 전력전자학회논문지
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• 제10권5호
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• pp.481-487
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• 2005

제안한 유도가열 시스템은 증류탑 장치에 사용되는 특수충진체에 의한 열교환기술과 IH(Induction-Heating)전자유도가열용의 특수한 고주파 전력회로 기술을 응용한 차세대 가열방식이다. 특히 일체의 연소과정이 없다는 점에서 작업환경의 개선이 가능하며 본 기술은 IGBT대응의 고주파 인버터를 사용하여 상용교류로부터 수[kHz]의 고주파 교류를 발생시킬 수 있다. 본 논문에서는 절연체 용기 내에 특수 스텐레스 발열체부하를 수납하여 용기 외부의 고주파 공진형 인버터 접속의 워킹코일로부터 비접촉 상태로 전자유도 와전류를 구조체에 흘림으로서 발열하게 되는 새로운 유체가열방식을 제안한다. 그리고 5[kW]급 풀-브릿지 공진형 인버터 시스템과 공진부하의 동작해석, 특성분석 및 본 시스템을 이용한 고효율 스팀 발생장치의 개발과 시스템의 응용에 대해 논하였다.

• Clinical and Experimental Pediatrics
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• 제57권6호
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• pp.264-270
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• 2014

Purpose: Acute necrotizing encephalopathy (ANE) is a fulminant disease of the brain characterized by bilateral thalamic lesions, and is prevalent among children in East Asia. The prognosis of ANE is usually poor with a high mortality rate and neurological sequelae. This study aimed to delineate the clinical characteristics and prognostic factors of ANE. Methods: We retrospectively analyzed clinical data of 399 pediatric patients with encephalitis who were admitted to Samsung Medical Center from December 1998 to March 2011. We enrolled ten patients (11 cases) with ANE and analyzed their demographic, clinical, and neuroimaging data. The location and extent of the brain regions were checked based on fluid-attenuated inversion recovery, T1-, and T2-weighted imaging findings; the presence of contrast enhancement, restricted diffusion, and hemorrhage. Results: Ten patients were identified, including one patient with two episodes. The median age of onset was 1.5 years (0.4-8.4 years). The mortality rate was 40%, and only 30% of patients survived without neurological sequelae. The definite involvement of the brainstem on brain magnetic resonance imaging was significantly correlated with mortality (P =0.04). Conclusion: Broad and extensive brainstem involvement suggested the fulminant course of ANE. Early diagnosis of ANE before brainstem involvement, through careful identification of symptoms of brain dysfunction, may be the best way to achieve better neurological outcomes.

• Earthquakes and Structures
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• 제11권6호
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• pp.1001-1025
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• 2016

Building structures generally have inherent low damping capability and hence are vulnerable to seismic excitations. Control devices therefore play a useful role in providing safety to building structures subject to seismic events. In recent years semi-active dampers have gained considerable attention as structural control devices in the building construction industry. Magneto-rheological (MR) damper, a type of semi-active damper has proven to be effective in seismic mitigation of building structures. MR dampers contain a controllable MR fluid whose rheological properties vary rapidly with the applied magnetic field. Although some research has been carried out on the use of MR dampers in building structures, optimal design of MR damper and combined use of MR and passive dampers for real scale buildings has hardly been investigated. This paper investigates the use of MR dampers and incorporating MR-passive damper combinations in building structures in order to achieve acceptable levels of seismic performance. In order to do so, it first develops the MR damper model by integrating control algorithms commonly used in MR damper modelling. The developed MR damper is then integrated in to the seismically excited structure as a time domain function. Linear and nonlinear structure models are evaluated in real time scenarios. Analyses are conducted to investigate the influence of location and number of devices on the seismic performance of the building structure. The findings of this paper provide information towards the design and construction of earthquake safe buildings with optimally employed MR dampers and MR-passive damper combinations.

• Journal of Yeungnam Medical Science
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• 제31권1호
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• pp.43-47
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• 2014

Extramedullary plasmacytoma (EMP) is a rare disease that occurs in 3% to 5% of patients with plasma cell disorder. It occurs most commonly in the upper respiratory tract and the oral cavity. Very few EMP cases have been reported in the central nervous system (CNS). We report herein an unusual case of EMP in the nasal cavity that recurred in the CNS without systemic involvement. A 67-year-old man visited our hospital due to a month-long bout with exophthalmos. He was diagnosed with EMP in the nasal cavity, paranasal sinus, and orbital cavity. He received radiotherapy to which he had complete responses. After 2 years, he visited our hospital because of a month-long headache. He was diagnosed with EMP recurrence in the CNS via brain magnetic resonance imaging and cerebrospinal fluid analysis. He was treated with whole brain radiotherapy and intrathecal chemotherapy with methotrexate, but he expired due to pneumonia.

• Journal of Yeungnam Medical Science
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• 제30권1호
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• pp.25-30
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• 2013

Hyponatremia, the most common electrolyte disorder, has been rarely reported as causing rhabdomyolysis. Osmotic demyelination syndrome (ODS), a demyelinating disease of the central pons and/or other areas of the brain, is infrequently reported as associated with rapid correction of hyponatremia. This paper reports a case of ODS after correction of severe hyponatremia complicated by rhabdomyolysis. A 47-year-old female with a history of chronic alcoholism presented herself at the hospital with altered consciousness after three days of nausea and vomiting. She was on a thiazide diuretic for essential hypertension. Her blood tests upon her hospital admission showed hyponatremia ($Na^+$ 98 mEq/L), hypokalemia ($K^+$ 3.0 mEq/L), and elevation of her serum creatine phosphokinase (3,370 IU/L) with an increase in her serum myoglobin level 11,267 ng/mL). She was treated with intravenous fluid therapy that included isotonic and hypertonic salines along with potassium chloride. She became more alert, and her neurological condition gradually improved after the first five days of her therapy. On the ninth day after her admission, she developed progressive quadiaresis associated with dysarthria, dysphagia, and dystonia despite the resolution of her hyponatremia. Magnetic resonance imaging of her brain on 16th day revealed symmetrical areas of signal hyperintensity in her central pons, basal ganglia, and precentral gyrus in T2-weighted images, which are consistent with ODS. Her neurological symptoms steadily improved after six weeks with only supportive treatment and rehabilitation.

• Journal of Korean Neurosurgical Society
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• 제29권12호
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• pp.1634-1641
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• 2000

Objective : The cerebrospinal fluid(CSF) pulsates within the craniospinal axis in response to rhythmic cerebral blood volume variation during the cardiac cycle. The aim of this study is to characterize the normal and abnormal CSF flow and its waveforms in the cervical spinal subarachnoid space. Methods : The magnetic resonance(MR) images were obtained with 1.5 T(GE Signa, GE Medical Systems, Milwaukee, USA) unit using the 2 dimensional cine PC(phase contrast) sequence with cardiac gating and gradient recalled echo imaging. This pulse sequence yielded 16 quantitative flow-encoded images per cardiac cycle. Sagittal and axial images of the cervical spinal CSF space were obtained, and target sites were analyzed for characteristic CSF flow (TR=50ms, TE=12.5-15ms). The region of interest(ROI) was 1mm 3 in volume. Twenty six persons were included in this study : 10 healthy volunteers and 16 patients with cervical myelopathy. The post-operative cine MR study were also done in five patients. Results : The normal CSF pulsation dynamics in the cervical spine showed discrete systolic and diastolic components. The CSF flow revealed a sine wave pattern, in which the systolic phase was shorter than the diastolic phase(ratio=2 : 3). The patient group revealed decreased amplitudes of the CSF flow and irregularly distored flow waves. The systolic phase was elongated in the ROI above the stenotic level, whereas the diastolic phase was lengthened below the level. In the postoperative images, the abnormal pattern and amplitude were found to be corrected. Conclusion : From these results, the authors believe that the CSF flow study provides valuable informations regarding the extent of cervical stenosis and may be useful for the surgical planning and post-operative evaluation.

• Journal of Korean Neurosurgical Society
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• 제53권5호
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• pp.312-315
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• 2013

Aspergillosis in the central nervous system (CNS) is a very rare disease in immune-competent patients. There was a case of a healthy man without a history of immune-compromised disease who had invasive aspergillosis with unusual radiologic findings. A 48-year-old healthy man with diabetes mellitus, presented with complaints of blurred vision that persisted for one month. Brain magnetic resonance imaging (MRI) showed multiple nodular enhancing lesions on the right cerebral hemisphere. The diffusion image appeared in a high-signal intensity in these areas. Cerebrospinal fluid examination did not show any infection signs. An open biopsy was done and intraoperative findings showed grayish inflammatory and necrotic tissue without a definitive mass lesion. The pathologic result was a brain abscess caused by fungal infection, morphologically aspergillus. Antifungal agents (Amphotericin B, Ambisome and Voriconazole) were used for treatment for 3 months. The visual symptoms improved. There was no recurrence or abscess pocket, but the remaining focal enhanced lesions were visible in the right temporal and occipital area at a one year follow-up MRI. This immune-competent patient showed multiple enhancing CNS aspergillosis in the cerebral hemisphere, which had a good outcome with antifungal agents.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2017년도 춘계학술대회 논문집
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• pp.156-156
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• 2017

In this work, analysis of biocompatible TiO2 oxide multilayer by the XPS depth profiling was researched. the manufacture of the TiO2 barrier-type multilayer was accurately performed in a mixed electrolyte containing HAp, Pd, and Ag nanoparticles. The temperature of the solution was kept at approximatively $32^{\circ}C$ and was regularly rotated by a magnetic stirring rod in order to increase the ionic diffusion rate. The manufactured specimens were carefully analyzed by XPS depth profile to investigate the result of chemical bonding behaviors. From the analysis of chemical states of the TiO2 oxide multilayer using XPS, the peaks are showed with the typical signal of Ti oxide at 459.1 eV and 464.8 eV, due to Ti 2p(3/2) and Ti 2p(1/2), respectively. The Pd-3d peak was split into Pd-3d(5/2) and Pd-3d(3/2)peaks, and shows two bands at 334.7 and 339.9 eV for Pd-3d3 and Pd-3d5, respectively. Also, the peaks of Ag-3d have been investigated. The chemical states consisted of the O-1s, P-2p, and Ti-2p were identified in the forms of PO42- and PO43-. Based on the results of the chemical states, the chemical elements into the TiO2 oxide multilayer were also inferred to be penetrated from the electrolyte during anodic process.The structure characterization of the modified surface were performed by using FE-SEM, and from the result of biological evaluation in simulated body fluid(SBF), the biocompatibility of TiO2 oxide multilayer was effective for bioactive property.

• Clinical and Experimental Pediatrics
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• 제53권4호
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• pp.603-606
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• 2010

부신생물 변연계뇌염(paraneoplastic limbic encephalitis)은 신경계의 전이가 없이 종양의 원격 작용에 의해 발생하는 질환으로 소아에서는 드물게 보고되고 있다. 저자들은 사춘기 여아에서 발생한 성숙 난소기형종에 동반된 부신생물 변연뇌염을 경험하고 보고하고자 한다. 15세 여자 환자가 신경정신증상, 기억력 저하, 경련, 의식 저하를 주소로 내원하였다. 뇌척수액 검사, 뇌 MRI는 정상이었으나, 뇌 SPECT 검사에서 양측 측두엽의 저관류가 관찰되었다. 복부 초음파와 MRI에서 좌측 난소의 낭성 종양이 발견되었다. 종양의 수술적 제거 후 성숙 난소기형종으로 확인되었으며, 종양 제거 및 면역글로불린 정맥 투여로 완전한 인지 기능의 회복을 보였다.

• Clinical and Experimental Pediatrics
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• 제53권4호
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• pp.607-611
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• 2010

Bickerstaff 뇌간 뇌염은(BBE) 4주 이내의 진행성이며, 비교적 대칭성으로 오는 안근 마비와 실조증, 의식 장애 또는 심부건 반사 항진 등의 임상적 특징을 가지며, 뇌간을 침범하는 타 질환을 배제하였을 때 진단할 수 있는 드문 질환이다. 혈청 또는 뇌척수액의 항 Ganglioside 항체(GM, GD and GQ) 는 때로 BBE의 진단에 도움이 되기도 하며, 뇌 자기 공명 영상, 뇌 척수액 검사, 신경 전도 검사 및 근 전도 검사 등은 진단에 크게 도움이 되지 않는다. 저자들은 안근 마비, 실조증, 언어 운동 장애, 연하 장애, 점진적 사지 마비, 의식 저하 등의 증상을 보이며 혈청과 뇌척수액에서 anti-GM1 항체의 증가를 보여 BBE로 진단하고 면역 글로불린과 스테로이드 치료 후 완치되었던 9세의 여아의 증례를 경험하였기에 문헌 고찰과 함께 이를 보고하는 바이다.