• 대한한의학회지
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• 제29권4호
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• pp.94-103
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• 2008

Objectives: The aim of this study was to determine whether celastrol, the triterpenoid component of Celastrus orbiculatus, offers neuroprotection against Parkinson's disease (PD) in mice administered 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine(MPTP). Methods: We examined how celastrol affected MPTP-induced neuronal loss of tyrosine hydroxylase (TH)-positive dopaminergic neurons in substantia nigra pars compacta (SNpc) in the midbrain of mice. C57BL/6J mice were divided into four groups: (1) saline-saline, (2) saline-celastrol, (3) MPTP-saline, and (4) MPTP-celastrol. The mice were injected intraperitoneally (i.p.) with four administrations of MPTP (18mg/kg) at 2 h intervals and then i.p. administered celastrol (3mg/kg) two times at 12 h after last celastrol administration. Expression of TH on the SNpc of brain tissues were analyzed at 7 days after the treatments by immunohistochemistry and Western blot. Results: Immunohistochemical analysis using TH antibody showed that celastrol provided significantly protective effects against MPTP-induced loss of TH-positive dopaminergic neurons in the SNpc region of the midbrain of mice. Our Western blot study also showed that celastrol significantly inhibits the MPTP-induced neuronal damage via the up-regulation of TH protein levels in MPTP mice. Conclusions: The present results suggest that it may be possible to use celastrol for the prevention of nigral degenerative disorders including PD, caused by exposure to toxic substances.

• 정보처리학회논문지D
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• 제12D권3호
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• pp.375-384
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• 2005

실세계의 많은 객체들은 시간적 정보와 공간적 정보를 함께 가지고 있고, 이러한 정보를 다루기 위한 시공간 데이터 모델링의 목적 중에 하나는 시공간 객체를 위한 응용프로그램을 지원할 수 있게 하는 것이다. 객체지향 시공간 모델은 객체단위로 시공간 데이터를 관리 할 수 있기 때문에 효율적으로 시공간 데이터를 관리할 수 있어야 한다. 따라서, 이 논문에서는 시공간 데이터 관리를 객체지향 방식으로 지원할 수 있도록 개방형 지리정보 시스템에서 제안한 2차원 공간모델을 실세계 정보에 맞게 차원적으로 확장하고, 시간 정보를 포함하도록 확장한 모델을 제안한다. 그리고, 제안된 모델의 타당성을 검증하기 위해, 모델을 위한 시공간 데이터 제공자 컴포넌트인 data source 컴포넌트, session 컴포넌트, command 컴포넌트와 rowset 컴포넌트를 구현하고 수행 예를 보인다. 제안된 시공간 데이터 모델과 데이터 제공자는 서로 다르게 저장된 시공간 데이터를 객체지향 모델링을 사용하여 저장, 검색 및 관리할 수 있게 한다.

• 대기
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• 제24권4호
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• pp.491-502
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• 2014

As a part of the KIAPS (Korea Institute of Atmospheric Prediction Systems) Package for Observation Processing (KPOP), we have developed the modules for Advanced Microwave Sounding Unit-A (AMSU-A) pre-processing and its bias correction. The KPOP system calculates the airmass bias correction coefficients via the method of multiple linear regression in which the scan-corrected innovation and the thicknesses of 850~300, 200~50, 50~5, and 10~1 hPa are respectively used for dependent and independent variables. Among the four airmass predictors, the multicollinearity has been shown by the Variance Inflation Factor (VIF) that quantifies the severity of multicollinearity in a least square regression. To resolve the multicollinearity, we adopted simple linear regression and Principal Component Regression (PCR) to calculate the airmass bias correction coefficients and compared the results with those from the multiple linear regression. The analysis shows that the order of performances is multiple linear, principal component, and simple linear regressions. For bias correction for the AMSU-A channel 4 which is the most sensitive to the lower troposphere, the multiple linear regression with all four airmass predictors is superior to the simple linear regression with one airmass predictor of 850~300 hPa. The results of PCR with 95% accumulated variances accounted for eigenvalues showed the similar results of the multiple linear regression.

• 한국광학회지
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• 제31권3호
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• pp.125-133
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• 2020

본 논문에서는 다변량 분석법과 결합된 레이저 유도 플라즈마 분광법을 사용하여 겹친 유류 지문을 분리하는 혁신적인 방법을 연구하였다. LIPS는 겹친 유류 지문의 화학 성분에 대한 데이터뿐 아니라 실시간 분석 및 고속 스캐닝이 가능한 분광법이다. 레이저 유도 플라즈마 분광법을 통해 도출된 스펙트럼은 적절한 다변량 분석이 적용되어 법의학적 분류와 겹친 유류 지문의 재구성에 유용한 화학적 성분을 제공한다. 본 연구에서는 LIPS 스펙트럼에서 4가지의 유류 지문을 분류하기 위하여, 주성분 분석 방식과 부분 최소 제곱 회귀 분석을 사용하였다. 제안된 방법은 SIMCA 및 PLS-DA와 같은 구별 방식을 사용하여 4개의 유류 지문의 분류를 성공적으로 입증하였다. 본 연구의 결과는 대략 85% 이상의 정확도를 가졌으며, external validation 실험에서도 분류의 가능함을 보였다. 최종적으로, 125 ㎛의 공간 간격으로 레이저 스캐닝 분석을 통한 겹친 유류 지문의 2차원 형태의 분리가 가능함을 입증하였다.

• Journal of Yeungnam Medical Science
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• 제38권2호
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• pp.127-135
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• 2021

Background: Dialysis patients are prone to having disabilities. We aimed to evaluate the association between disability and various clinical outcomes in Korean dialysis patients. Methods: This study consisted of 1,615 dialysis patients from 27 centers. We evaluated disability by using four questions on the activities of daily living (ADLs) concerning whether help was needed for feeding, dressing/undressing, getting in/out of bed, or taking a bath/shower. We divided the patients into three groups: no disability (Non-D, none of the four ADL domains required help; n=1,312), mild disability (Mild-D, one ADL domain required some/full help; n=163), or moderate to severe disability (MS-D, two or more ADL domains required some/full help; n=140). We evaluated falls, frailty, health-related quality of life (HRQoL), mortality, and hospitalization. Results: The numbers of participants with a fall during the last 1 year were 199 (15.2%), 42 (25.8%), and 44 (31.4%) in the Non-D, Mild-D, and MS-D groups, respectively (p<0.001). The numbers of participants with frailty in the Non-D, Mild-D, and MS-D groups were 381 (29.0%), 84 (51.5%), and 93 (66.4%), respectively (p<0.001). In both univariate and multivariate analyses, the physical component scale and mental component scale scores decreased as the grade of disability increased (p<0.001 for both scores). Hospitalization-free survival rate at 500 days was 64.2%, 56.7%, and 51.1% in the Non-D, Mild-D, and MS-D, respectively (p=0.001 for trend). Patient survival rate at 500 days was 95.3%, 89.5%, and 92.3% in the Non-D, Mild-D, and MS-D, respectively (p=0.005 for trend). Conclusion: Disability was associated with falls, frailty, HRQoL scales, and survival trends in Korean dialysis patients.

• 한국과학교육학회지
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• 제44권1호
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• pp.1-9
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• 2024

본 연구는 중학교 학생의 기술지향, 생태지향 및 지속가능발전 환경적 세계관을 조사하여 교육적 시사점을 얻고자 하였다. 중학교 학생의 환경적 세계관은 자연 환경 영역 자연에서의 사람의 가치, 자연 환경의 가치, 사람의 자연 지배, 환경 생태계의 평형 유지 능력의 4개 범주, 사람의 행동과 환경 영역은 에너지 및 자원 고갈, 기술 개발, 경제 성장, 환경 문제의 심각성의 4개 범주 등 2개 영역, 총 8개 범주로 구분하여 조사하였다. 연구 대상은 10개 중학교 남학생 152명, 여학생 224명 등 총 356명이었으며, 온라인 설문 조사 사이트에 자발적으로 접속하여 리커르트 4점 척도(1~4)로 응답하도록 하였다. 중학교 학생들은 기술지향 환경적 세계관 보다는 지속가능발전 환경적 세계관과 생태지향 환경적 세계관을 갖는 것으로 나타났다. 중학교 여학생이 남학생에서 비해 지속가능발전 환경적 세계관에 대한 높은 경향성을 갖는 것으로 나타났다. 중학교 학생이 지속가능발전 환경적 세계관을 유지하고 이에 대응하여 실천할 수 있는 교육적 접근이 필요하다.

• 대한약침학회지
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• 제14권1호
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• pp.5-24
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• 2011

Objective: This study was performed to analyse four weeks repeated -dose toxicity of Sweet Bee Venom (SBV-pure melittin, the major component of honey bee venom) in rats. Methods: All experiments were conducted under the regulations of Good Laboratory Practice (GLP) at Biotoxtech Company, a non-clinical study authorized institution. Male and female rats of 5 weeks old were chosen for the pilot study of four weeks repeated-dose toxicity and was injected at the level of 0.56 mg/kg body weight (eighty times higher than the clinical application dosage as the high dosage), followed by 0.28 and 0.14 mg/kg as midium and low dosage, respectively. Equal amount of normal saline was injected as the control group every day for four weeks. Results: 1. No mortality was witnessed in all of the experiment groups. 2. All experiment groups appealed pain sense in the treating time compared to the control group, and side effects such as hyperemia and movement disorder were observed around the area of injection in all experiment groups, and the higher dosage in treatment, the higher occurrence in side effects. 3. Concerning weight measurement, neither male nor female groups showed significant changes compared to the control group. 4. Concerning to the CBC and biochemistry, all experiment groups didn't show any significant changes compared to the control group. 5. Concerning weight measurement of organs, experiment groups didn't show any significant changes compared to the control group. 6. To verify abnormalities of organs and tissues, those such as cerebellum, cerebrum, liver, lung, kidney, and spinal cords were removed and we conducted histologocal observation with H-E staining. Concerning the histologocal observation of liver tissues, some fatty changes were observed around portal vein in 0.56 mg/kg experiment group. But another organs were not detected in any abnormalities. 7. The proper high dosage of SBV for the thirteen weeks repeated test in rats may be 0.28 mg/kg in one time. Conclusion: Above findings suggest that SBV is relatively safe treatment medium. Further studies on the subject should be conducted to yield more concrete evidences.

• 대한간호학회지
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• 제39권4호
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• pp.584-593
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• 2009

Purpose: The purpose of this study was to investigate the effect of stretching, muscle strengthening, and walking exercise on the cardiopulmonary function and health-related quality of life in hemodialysis patients. Methods: Twenty-one patients in the intervention and the control group participated in the exercise respectively on maintenance hemodialysis at four university hospitals. The exercise was composed of 20 to 60 min per session, 3 sessions a week for 12 weeks. The effect of exercise was assessed by cardiopulmonary function (peak oxygen uptake, peak ventilation, peak respiration rate, maximal heart rate, and exercise duration) using a cycle ergometer. Grip strength was measured by dynamometer, and flexibility was measured by sit and reach measuring instrument. Health-related quality of life was measured using Medical Outcomes Study Short Form-36. Results: Peak oxygen uptake, peak ventilation, peak respiration rate, exercise duration, grip strength, flexibility, and physical component scale were significantly improved in the intervention group after 12 week's exercise compared to the control group. Conclusion: These findings indicate the exercise can improve cardiopulmonary function, grip strength, flexibility, and physical component scale of health-related quality of life in hemodialysis patients.

• 소성∙가공
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• 제21권7호
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• pp.397-402
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• 2012

The flange hub is a main component in an automotive steering system. In general, the flange hub are fabricated by mechanical machining, which is a process where material waste is inevitable. It is well-known that a net-shape cold forging cannot only reduce material waste but can also improve the mechanical strength of the final product. Thus, a forging process design was conducted for production of a flange hub. Significant spring-back occurs around the flange due to its small thickness in conjunction with the residual stresses after forging. In order to achieve the required dimensional accuracy, a process design with appropriate spring-back control is needed. In this study, a modification of the forging die was designed based on FE analysis with the purpose of spring-back compensation. Four kinds of different die designs were evaluated and the optimum design has two times less spring-back than the initial design. The compensation angle of the optimum design is 0.5 degrees. The results have been experimentally confirmed by cold forging of a flange hub and comparing the amount of spring-back between the actual component and the FE analysis.

• Journal of Nutrition and Health
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• 제38권2호
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• pp.104-111
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• 2005

Tumor invasion is composed of four steps: cell adhesion to the extracellular matrix, degradation of the extracellular matrix components, tumor cell motility followed by cell detachment. Matrix metalloproteinases (MMPs) are important proteinases that associated with degradation of matrix component. Epigallocatechin gallate (EGCG) is a major polyphenotic constituent of green tea. In the study, we examined the anti-invasive and MMP activity suppression effects of EGCG in MDA-MB-231 human breast cancer cells. MDA-MB-23l human breast cancer cells were cultured with various concentrations 0 - 100 μM of EGCG. EGCG significantly inhibited the cell adhesion to the fibronectin. Cell motility through gelatin filter and invasion to Matrigel were inhibited dose-dependently by EGCG treatment. EGCG also inhibited the activities of MMP-2, -9 and the amount of MMP-9 (α = 0.05). Therefore, EGCG may contribute to the potential beneficial food component to prevent the invasion and metastasis in breast cancer. (Korean J Nutrition 38(2): 104～111, 2005)