수냉쿨러의 냉각 효율 향상을 위한 플레이트 부품의 형상에 관한 연구

성윤호,김형찬,김선민,윤석영,이영웅,이상욱 순천향대학교 부설 산업기술연구소 2021 순천향 산업기술연구소논문집 Vol.27 No.2

This study investigates changes in cooling efficiency for heat sink plate width, perforated width, and chamfer angle as part of a parameter study to maximize cooling efficiency of heat sink by setting various variables on plates. The width of the plate is set to 16, 20, 24, 28 mm, perforated width 1.5, 2.0, 2.5 mm, chamfer angles 5, 10, 15 and 20°. By conducting a computational study with Ansys Fluent, the sink plate with plate width of 16mm, perforated width of 3mm and chamfer angle of 10° is shown to be the best cooling efficiency.

비정질 Sm - Fe 박막 합금의 자기적 거동

성윤호(Y. H. Seong),김경섭(K. S. Kim),유성초(S. C. Yu),임상호(S. H. Lim) 한국자기학회 1999 한국자기학회 학술연구발표회 논문개요집 Vol.9 No.1

B를 함유한 Tb - Fe 박막의 자기적 거동

성윤호(Y. H. Seong),김경섭(K. S. Kim),유성초(S. C. Yu),임상호(S. H. Lim) 한국자기학회 1998 한국자기학회 학술연구발표회 논문개요집 Vol.8 No.1

H-반사 촉진의 소실: 길랑-바레 증후군의 초기 이상과 중추신경 침범의 증거로써의 의미

성정준,이윤정,홍윤호,정영민,이광우 대한임상신경생리학회 2002 Annals of Clinical Neurophysiology Vol.4 No.2

Background : Guillain-Barre syndrome(GBS) is a neurologically emergent condition, leading to respiratory insufficiency without an early and appropriate treatment. Thus, the treatment of GBS requires early diagnosis but it is difficult due to the low sensitivity of laboratory tools in the initial stage. Hoffman reflex (H-reflex) and its facilitation by Jendrassik maneuver (JM) are sensitive tools evaluating the central circuit of motor system on the spinal cord level. The aim of this study is to test whether the change of H-reflex and F-wave under the JM is able to detect the early stage of GBS and whether GBS involves the central nervous system (CNS). Material and Methods : All 7 GBS patients who showed normal or nearly normal nerve conduction study were included. The facilitation of H-reflex and changes of F-wave were calculated by measuring the percent difference f H-reflex or F-wave amplitude under JM compared to basal H-reflex of F-wave amplitude. The changes of F-wave and H-reflex in the GBS patients were compared with them of 8 healthy controls. Results : The F-wave amplitudes of both healthy controls and GBS patients did not changed under the influence of JM (102.4±24.9 %, 108.7±29.0% respectively). However, the facilitation of H-wave by JM in the GBS patients was absent (98.8±5.8%), even though the H-reflex amplitude I the healthy controls increased under the influence of JM (124.8±12.1%). Conclusions : The loss of H-reflex facilitation in GBS implies that this phenomenon might be the most early change detected in the electrophysiological study and support the early diagnosis, and that GBS might include lesion in the spinal motor CNS.

돌연변이 Cu,Zn-superoxide dismutase 유전자를 발현하는 운동신경세포에 대한 Homocysteine의 선택적 세포독성 기전

성정준,김현정,김성민,민주홍,홍윤호,박경석,김만호,이석호,호원경,이광우 대한신경과학회 2006 대한신경과학회지 Vol.24 No.1

Background: Mutations in Cu, Zn-superoxide dismutase (SOD1) cause about 20% of familial amyotrophic lateral sclerosis (FALS) cases. The mechanism of late-onset disease manifestation despite the innate mutation has no clear explanation. The relationship between homocysteine (HC) and amyotrophic lateral sclerosis (ALS) has not been investigated fully, in spite of the similarity in their pathogenesis. Methods: We investigated the effect of HC on the motor neuronal cell-line (VSC4.1) transfected with SOD1 of either wild-type or mutant forms (G93A and A4V) using various methods including the MTT assay for the cytotoxic assay, the immunocytochemical staining using anti-SOD1 for the aggregation of SOD1, the western blotting using anti-nitrotyrosine and anti-DNPH for the oxidative protein damage, and the measurement of the intracellular Ca2+ concentration using Fura2-AM. Results: In the MTT assay, the HC induced significant cytotoxicity in the mutants, as compared with wild-type. This HC-induced cytotoxicity was inhibited by the trolox and the bathocuproinedisulfonate (BC). HC increased the carbonylation and nitrosylation of the mutant proteins. HC also increased significant SOD1-aggregation in mutants. This HC-induced SOD1-aggregation in mutants was inhibited by trolox, N-nitro-L-arginine methyl ester, BC, and z-VAD-FMK. HC did not change the intracellular concentration of Ca2+ in the mutants compared with the wild-type. Conclusions: The authors showed that the vulnerability of the SOD1 mutant motor neuronal cells to HC involves the copper-mediated oxygen radical toxicity, and that HC may be a lifelong precipitating factor in some forms of FALS, suggesting a possible treatment modality with vitamin supplements.

염색체 17p11.2유전자 결손을 동반한 유전성 압막마비 편향 신경병증의 임상적, 전기생리학적 특성

홍윤호,김만호,성정준,김성훈,이광우 대한임상신경생리학회 2002 Annals of Clinical Neurophysiology Vol.4 No.2

Objectives : Although the diagnosis of hereditary neuropathy with liability to pressure palsies(HNPP) in important for correct prognostic evaluation and genetic counseling, the diagnosis is frequently missed or delayed. Our main aim on undertaking this study was to characterized the electrodiagnostic features of HNPP. Material and Methods : Clinical, electrophysiologic and molecular studies were performed on Korean HNPP patients with 17P11.2 deletion. The results of eletrophysologic studies were compared with those of Charcot-Marie-Tooth disease type 1A (CMT1A) patients carrying 17p11.2 duplication. Results : Eight HNPP (50 motor, 39 sensory nerves) and six CMTIA (28 motor, 16 sensory nerves) patients were included. The slowing of sensory conduction in nearly all nerves and the distal accentuation of motor conduction abnormalities are the main features of background polyneuropathy in HNPP. In contrast to CMTIA, where severity of nerve conduction slowing was not different among nerve groups, HNPP sensory nerve conduction was more slowed in the median and ulnar nerves than in the sural nerve (p<0.01), and DML was more prolonged in the median nerve than in the other motor nerves (p<0.01). TLIs were significantly lower in HNPP than in the normal control and CMTIA patients for the median and ulnar nerves (p<0.01), and were also significantly reduced for the peroneal nerve (p<0.05) compared with those of the normal controls. Conclusion : The distribution and severity of the background electrophysiologic abnormalities are closely related to the topography of common entrapment or compression sites, which suggests the possible pathogenetic role of subclinical pressure injury at these sites in the development of the distinct background polyneuropathy in HNPP.

Multiple Symmetric Lipomatosis Presenting with Bilateral Brachial Plexopathy

박기홍,홍윤호,최석진,성정준,이광우 대한신경과학회 2015 Journal of Clinical Neurology Vol.11 No.4

감초 유발성 저칼륨혈증성 근육병증 1예

김범준,홍윤호,성정준,박경석,현창림,최기영,박성호,이광우 대한신경과학회 2006 대한신경과학회지 Vol.24 No.4

Glycyrrhizin, the main ingredient of licorice, may evoke severe hypokalemia and muscle paralysis by its mineralocorticoid effects. We present a 78-year-old man who developed subacute flaccid quadriparesis with a high creatine kinase (CK) level, hypokalemia, metabolic alkalosis, and low plasma renin activity after ingesting licorice daily for two years. A muscle biopsy revealed vacuolar degeneration of myofibers. This case suggests that glycyrrhizin (licorice)-induced hypokalemic myopathy must be included in the differential diagnosis of a patient with generalized muscle weakness and hypokalemia.

Oral Solubilized Ursodeoxycholic Acid Therapy in Amyotrophic Lateral Sclerosis: A Randomized Cross-Over Trial

민주홍,홍윤호,성정준,김성민,이정복,이광우 대한의학회 2012 Journal of Korean medical science Vol.27 No.2

To evaluate the efficacy and safety of ursodeoxycholic acid (UDCA) with oral solubilized formula in amyotrophic lateral sclerosis (ALS) patients, patients with probable or definite ALS were randomized to receive oral solubilized UDCA (3.5 g/140 mL/day) or placebo for 3 months after a run-in period of 1 month and switched to receive the other treatment for 3 months after a wash-out period of 1 month. The primary outcome was the rate of progression, assessed by the Appel ALS rating scale (AALSRS), and the secondary outcomes were the revised ALS functional rating scale (ALSFRS-R) and forced vital capacity (FVC). Fifty-three patients completed either the first or second period of study with only 16 of 63 enrolled patients given both treatments sequentially. The slope of AALSRS was 1.17 points/month lower while the patients were treated with UDCA than with placebo (95% CI for difference 0.08-2.26, P = 0.037), whereas the slopes of ALSFRS-R and FVC did not show significant differences between treatments. Gastrointestinal adverse events were more common with UDCA (P < 0.05). Oral solubilized UDCA seems to be tolerable in ALS patients, but we could not make firm conclusion regarding its efficacy, particularly due to the high attrition rate in this cross-over trial.

다발근육염과 피부근육염에서 관찰된 중첩증후군

박경석,김남희,홍윤호,성정준,남현우,박성호,이광우 대한임상신경생리학회 2007 Annals of Clinical Neurophysiology Vol.9 No.1

Background: The term “overlap syndromes” designates a group of diseases in which polymyositis (PM) or dermatomyositis (DM) is associated with some other disorders of connective tissues. The aim of this study was to delineate the clinical features, laboratory findings, and outcome of treatment of “overlap syndromes” Methods: We analyzed the medical records of 16 patients (PM in 10, DM in 6) with well documented “overlap syndromes” between 1997 and 2004. The diagnosis was made when the criteria for two different disorders were fulfilled. Results: All patients were female. Age of onset ranged from 14 to 52 years (mean 29.8 years) with peak incidence in the third and fourth decades. Systemic lupus erythematosus (SLE) was associated in 10, systemic sclerosis in 7, and rheumatoid arthritis in 3 patients. Four of the patients had two different connective tissue diseases simultaneously. The characteristic clinical features were muscle weakness, arthralgia, Raynaud’s phenomenon, and myalgia. In laboratory tests, creatine kinase (CK), lactic dehydrogenase (LDH), and transaminases were usually abnormal. Positive antinuclear antibody (ANA), rheumatoid factor (RF), and cryoglobulin were found in 100%, 69%, and 67% of the patients, respectively. Needle electromyography (EMG) showed abnormal findings compatible with myopathy in 15 patients. The pathology of muscle biopsy from 14 patients revealed findings compatible with inflammatory myopathy. Glucocorticoids were administered to 15 patients. The muscle strength improved in all the treated patients, which was well correlated with repeat CK level and EMG findings. Conclusions: The presence of autoantibodies such as ANA, RF, and cryoglobulin in patients with PM or DM highly suggests the possibility of an overlap syndromes. These syndromes reveal a strong female predominance. The myositis associated with them usually shows a good response to glucocorticoids treatment.