• Journal of Welding and Joining
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• 제24권6호
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• pp.21-27
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• 2006

This study was focused on the evaluation of the thermo-mechanical board-level reliability of Pb-bearing and Pb-free surface mount assemblies. The composition of Pb-bearing solder was a typical Sn-37Pb and that of Pb-free solder used in this study was a representative Sn-3.0Ag-0.5Cu in mass %. Thermal shock test was chosen for the reliability evaluation of the solder joints. Typical $Cu_6Sn_5$ intermetallic compound (IMC) layer was formed between both solders and Cu lead frame at the as-reflowed state, while a layer of $Cu_3Sn$ was additionally formed between the $Cu_6Sn_5$ and Cu lead frame during the thermal shock testing. Thickness of the IMC layers increased with increasing thermal shock cycles, and this is very similar result with that of isothermal aging study of solder joints. Shear test of the multi layer ceramic capacitor(MLCC) joints was also performed to investigate the degradation of mechanical bonding strength of solder joints during the thermal shock testing. Failure mode of the joints after shear testing revealed that the degradation was mainly due to the excessive growth of the IMC layers during the thermal shock testing.

• 한국식품위생안전성학회지
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• 제8권3호
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• pp.163-169
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• 1993

ICR 마우스를 이용하여 계면 활성제인 LAS-Na 와 MES의 급성 경구독성을 실시하였다. 6주령된 마우스 LAS-Na는 0, 1,000, 1,320, 1,780, 2,280, 3,000 mg/kg의 용량으로 MES는 0, 1,000, 1,560, 2,450, 3,830, 6,000mg/kg의 용량으로 1회 경구 투여한 후 14일간 관찰하였다. 두 물질 모두 관찰 기간동안 대조군에 비하여 유의성 있는 체중변화는 관찰되지 않았다. 시험물질과 관련된 주요 임상증상으로는 설사, 활동성 감소, 입모 등이 관찰되었다. 사체에 대한 부검결과 시험물질에 의한 것으로 판단되는 소장 점막의 충혈이 소수례 관찰되었으며, 생존 동물에서는 특이한 만한 이상소견은 발견되지 않았다. 이상의 결과로부터 $LD_{50}$값은 LAS-Na의 경우 수컷과 암컷에서 각각 1,319 mg/kg, 1,402 mg/kg이었으며, MES의 경우 수컷에서는 2,040 mg/kg, 암컷에서는 2,546 mg/kg으로 산출되었다.

• Journal of Ginseng Research
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• 제42권4호
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• pp.429-435
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• 2018

Background: Recent studies have shown that Korean Red Ginseng (KRG) successfully protects against dopaminergic neuronal death in the nigrostriatal pathway of a Parkinson's disease (PD) mouse model induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration; however, the mechanism has yet to be identified. Therefore, in this study we used two-dimensional electrophoresis to investigate the effects of KRG on the changes in protein expression in the substantia nigra (SN) of MPTP-treated mice. Methods: Male C57BL/6 mice (9 wk old) were intraperitoneally administered MPTP (20 mg/kg) four times at 2-h intervals, after which KRG (100 mg/kg) was orally administered once a day for 5 d. Two hours after the fifth KRG administration, a pole test was conducted to evaluate motor function, after which the brains were immediately collected. Survival of dopaminergic neurons was measured by immunohistochemistry, and protein expression was measured by two-dimensional electrophoresis and Western blotting. Results: KRG alleviated MPTP-induced behavioral dysfunction and neuronal toxicity in the SN. Additionally, the expression of eight proteins related to neuronal formation and energy metabolism for survival were shown to have changed significantly in response to MPTP treatment or KRG administration. KRG alleviated the downregulated protein expression following MPTP administration, indicating that it may enhance neuronal development and survival in the SN of MPTP-treated mice. Conclusion: These findings indicate that KRG may have therapeutic potential for the treatment of patients with PD.

• Annals of Clinical Neurophysiology
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• 제7권2호
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• pp.101-106
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• 2005

Background: There is no currently effective treatment for amyotrophic lateral sclerosis (ALS), although this disorder is a progressive neurodegenerative disease resulting in death within several years. Because recent evidence suggests that homocysteine (HC) is highly related to neurodegenerative disorders with aging, we tried to elucidate the effects of multi-vitamin therapy on G93A SOD1 transgenic mice. Methods: We treated this murine model of ALS with multi-vitamin (folic acid 1.97 mg/day, pyridoxine 0.98 mg/day, cyanocobalamin 0.1 mg/day) from 45 days of age, per oral. We performed the rotarod test from postnatal $10^{th}$ week, weekly. Results: We found that multi-vitamin reinforcement significantly prolonged average lifespan and delayed disease onset with improvement of motor performance. However, it did not significantly slow disease progression and statistical differences of weight loss were not observed between in transgenic mice and controls. Conclusions: These results suggest that multi-vitamin can be a potent therapeutic strategy for familial forms of ALS.

• 국제물리치료학회지
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• 제10권2호
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• pp.1768-1773
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• 2019

Background: Aging reduces cognitive abilities, including visual memory (VM) and visual discrimination (VD). Since common cortical networks subserve eye movement and attention, voluntary eye movement may improve visual attention. Visual selective attention was major role for memory, and visual memory and visual attention are intimately related. Objective: To identify the improvement in VD and VM, after implementing the eye movement program consisting of saccadic eye movement (SEM) and pursuit eye movement (PEM) in the institutionalized healthy elderly. Design: Randomized controlled trial. Methods: The study involved a sample of 36 participants, and the mean age was 79.03 years (range 76~84 years). They were randomly allocated to the experimental group (n=16) and control group (n=20). Participants in the experimental group performed SEM 5 times per week for 4 weeks: twice daily at the same time in the morning and afternoon. The program was carried out for 3 minutes, and it consisted of SEM and PEM. The target's moving frequency was set at 0.5 Hz. VM and VD at the baseline and post-intervention were measured using Motor-Free Visual Perception test-4 (MFVPT-4). Results: VM significantly improved in the experimental group (p < .01), and significant differences were observed compared to the control group (p < .01). There was no significant change in VD. Conclusion: The eye movement program consisting of SEM and PEM increased VM more than VD. Therefore, eye movement program was feasible interventions for improving VM in institutionalized elderly persons.

• 대한통합의학회지
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• 제10권2호
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• pp.1-11
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• 2022

Purpose : This study was conducted to assess the status of sarcopenia and locomotive syndrome in the Korean elderly population over 65 years of age by applying the recently updated screening tool for diagnostic evaluation of sarcopenia and locomotive syndrome. Methods : Sarcopenia and locomotive syndrome (LS) were diagnosed and evaluated in 210 Korean elderly people over 65 years of age. There were 36 patients in the "sarcopenia group", 164 in the "locomotive syndrome group", and 10 in the "normal group". The collected data were analyzed using the chi-square and Kruskal-Wallis tests. Results : The diagnostic evaluation of sarcopenia and LS showed the presence of sarcopenia in 9.05 % of males and 8.10% females among the Korean elderly population over 65 years of age. Prevalence of stage 1 locomotive syndrome (LS 1) was 95.24 %; stage 2, (LS 2) 36.19 %; and stage 3 (LS 3), 16.19 % among the study population. Both the sarcopenia diagnostic indicator and the LS evaluation indicators showed significant differences between the three groups. All the subjects in the sarcopenia group had LS; further, on comparison of the detailed composition ratio of each patient with LS, the prevalence of LS in the sarcopenia group was found to be: LS 1 41.67 %, LS 2 41.67 %, and LS 3 16.67 %, whereas in the LS group, it was found to be: LS 1 66.46 %, LS 2 16.46 %, and LS 3 17.07 %. The difference between the two groups was statistically significant. Conclusion : It was confirmed that sarcopenia is correlated with LS incidence. This suggests that the evaluation of motor LS can be used as a tool for the early diagnosis and prevention of sarcopenia in cases of functional decline due to aging in the elderly population.

• 한국산업융합학회 논문집
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• 제25권6_2호
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• pp.1097-1102
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• 2022

With the continuous development of the current industry, the current global environment is in a very serious situation, with resource supply and demand dependent on imports and huge costs for waste disposal due to the depletion of resources and mass generation of industrial waste. Its limitations have already been revealed in many fields, and the importance of re-manufacturing is drawing attention as a countermeasure to these problems. Re-manufacturing aims to recover products that are in the aging and disposal stages, recover to performance close to new products, and re-commercialize them. Among them, most of the machine tools are made of materials such as steel and cast iron with large structures, and raw materials are widely used when producing new products. In addition, since a lot of carbon is generated due to production, it is an object that can obtain a great re-manufacturing effect. Planner millers belonging to large machine tools are one of the machine tool equipment that can greatly reduce resources and energy through re-manufacturing because the structure is very large and the casting is several to tens of tons. Through this machine tool, performance tests and results are derived on the development of re-manufacturing source technology and domestic servo motor and CNC control device.

• 대한의생명과학회지
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• 제2권1호
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• pp.71-90
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• 1996

장기간 반복 주행운동이 횐 쥐의 심근에 미치는 효과를 규명하기 위하여 생후 3개월,10개 월 및 20개월 된 횐 쥐를 운동군과 대조군으로 대별하여 motor driven treadmill을 이용하여 Park등이 사용한 방법에 준해서 5개월간, 주 5일 20분간 운동을 시킨 후 심근의 조직 및 세포학적 변화를 관찰하고 심근 세포 내 미세구조 변화를 입체해석학적으로 비교 분석하였다. 연령 증가에 따라 장기간 반복운동이 휜쥐 심근미세구조에 미치는 영향은 8, 15개월의 운동군과 대조군 사이에 뚜렷한 차이를 인정할 수 없으며, 15개월의 운동군에서 대조군에 비하여 변성된 사립체, 리소조옴, 지방적, 공포, 노화색소 등이 증가하는 경향이 있었다. 25개월 운동군은 같은 연령 대조군에 비하여 근원섬유 수축대, 근원섬유 소실, 윤반분리,세포간질 증식, 핵의 변성,교원섬유 근섬유내 침입 등 매우 심한 변화를 보였다. 조직상에 나타나는 early lipofusin과 미세구조상에 나타나는 노화색소는 8, 15개월의 운동군과 대조군 사이에 유의한 차이는 없었으며, 25개월 운동군은 같은 연령 대조군에 비하여 유의한 차이로 증가하였다. Glucose-6-phosphatase 활성도 8, 15개월군에서 운동군과 대조군에서 모두 활성이 높았으며 25개월의 대조군과 운동군에서는 모두 활성이 거의 나타나지 않았다. 미세구조 변화를 입체해석학적으로 분석한 결과 8, 15개월의 대조군과 운동군에서 체적 밀도의 모든 항은 양군사이에 유의한 차이가 없었다. 25개월에서는 세포간질이 대조군에 비하여 운동군이 유의한 증가를 나타내었고, 근원섬유는 유의한 차이는 없지만 증가하는 경향을 보였으며, 사립체는 대조군에 비하여 유의 한 감소를 나타내었고 근형질세망의 체적밀도는 감소하는 경향을 보였다. 사립체와 근원섬유 비는 8개월 운동군에서 유의한 차이는 없지만 대조군에 비하여 높게 나타났으며, 15개월의 운동군과 대조군 사이에서는 차이를 인정할 수 없었다. 그러나 25개월 운동군은 대조군에 비하여 유의한 차이로 감소하였다. 연령증가에 따른 사립체 내막 표면밀도와 사립체수는 대조군과 운동군 사이에는 유의한 변화는 없었다. 본 연구의 성적을 검토한 결과 젊은층(3개월군)과 중령층(10개월군)의 횐 쥐에서는 반복된 지구력운동이 심장에 미치는 역효과를 인정할 수 없었으며 젊은 층의 횐 쥐에서는 오히려 심장기능 강화를 보이는 경향이 나타났으며, 노화층(20개월군)에서 운동군에서는 스트레스로 작용하여 심장기능의 저하를 초래하였다고 생각된다.

• 한국건설관리학회논문집
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• 제15권5호
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• pp.31-39
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• 2014

현대사회에서 자동차는 통근 통학뿐만 아니라 여가 및 편의생활을 위한 매우 중요한 이동수단으로 자리매김한지 오래다. 특히 대표적인 개인 이동수단인 승용차는 개인소득 증대와 개인의 여가시간과 편의 중시하는 라이프 스타일 변화로 인해 1970년대 이후 꾸준히 증가하였다. 1970년 우리나라 인구 천명당 1.9대에 불과했던 승용차는 2012년 기준 291.5대로 42년만에 153배가 증가한 매우 가파른 증가속도로 보유대수를 늘려왔다. 이러한 승용차 보유대수의 예측은 향후 자동차 관련 산업이나 도로건설 및 시설물 설치 등을 위한 계획, 시공, 관리 등에서도 중요한 기초자료가 될 수 있다. 따라서 본 연구에서는 성장곡선모형을 이용한 승용차 보유대수 예측을 실시하였으며, 특히 인구 고령화 변수를 포함시켜 보유율에 어떤 영향을 미치는지 분석하였다. 분석결과, 2020년대 초에 1차 포화점을 지나 2045년에는 인구 천명당 486.8대를 보유할 것이며, 또한 인구 고령화의 영향으로 고령화 문제가 없을 때에 비해 2045년의 보유대수는 10%가까이 낮은 수치를 가질 것으로 예측되었다.

• Journal of Acupuncture Research
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• 제21권4호
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• pp.19-29
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• 2004

Objective : The purpose of this study is to present the epidemiological data on patients with a stroke admitted to Department of Acupuncture & Moxibustion, Oriental Medical Hospital Kyung Hee University and to investigate the difference between preceding diseases of stroke. Methods : We reviewed medical records of 700 patients with a stroke admitted to Department of Acupuncture & Moxibustion, Oriental Medical Hospital, Kyung Hee University. Results: The incidence of cerebral infarction was 6.7 times that of cerebral hemorrhage. The incidence in males was 1.28 times of that in females. The incidence of stroke increased with aging and more cerebral hemorrhage occured in lower age group than cerebral infarction. There was higher morbidity in October, during the changing of the seasons, than any other months. Hypertension was the most common preceding disease followed by diabetis mellitus, heart disease, hyperlipidemia, and according to Odds's ratio for Male/Female, the probability of having preceding diseases was higher in females than males. In cerebral infarction, MCA territory was the most frequent lesion sites. Of the cerebral hemorrhage, basal ganglia (60%) was the most commonly involved site which was followed by thalamus(33.3%), cortex (3.3%) and subcortex (2.2%). The most common symptom accompanied by stroke was motor dysfunction which was followed by verbal disturbance, urination disorder and dysphagia. Conclusion : This study showed the trends of stroke in Oriental medical center. We expects that Multicenter cooperative and prospective study including Oriental Medicine will be inspired by this study for establishing more accurate chacteristics of stroke in Korea in the future.