• The Journal of Korean Medicine
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• v.29 no.4
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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.

• The KIPS Transactions:PartD
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• v.12D no.3 s.99
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• pp.375-384
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• 2005

Most of data objects in the real world have spatial and temporal information simultaneously. One of the objectives of spatiotemporal databases is to provide a very expressive framework for spatiotemporal database applications. The object oriented spatiotemporal model can manage spatiotemporal data efficiently because the model is able to store the complete history of any objects. Therefore, in order to handle the spatiotemporal data in object oriented fashion, we proposed a low dimensional spatiotemporal model in the object oriented fashion that extended dimensionally two dimensional spatial model of OpenGIS to fit into the real world information and to include temporal information. In order to proof the proposed model, we design a data provider component which consists of the data source, the session, the command, and the rowset component, and implement it. The proposed four dimensional spatiotemporal data model and provider in the object oriented fashion can be used to store, retrieve and manage the object oriented spatiotemporal data.

• Atmosphere
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• v.24 no.4
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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.

• Korean Journal of Optics and Photonics
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• v.31 no.3
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• pp.125-133
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• 2020

An innovative method for separating overlapping latent fingerprints, using laser-induced plasma spectroscopy (LIPS) combined with multivariate analysis, is reported in the current study. LIPS provides the capabilities of real-time analysis and high-speed scanning, as well as data regarding the chemical components of overlapping fingerprints. These spectra provide valuable chemical information for the forensic classification and reconstruction of overlapping latent fingerprints, by applying appropriate multivariate analysis. This study utilizes principal-component analysis (PCA) and partial-least-squares (PLS) techniques for the basis classification of four types of fingerprints from the LIPS spectra. The proposed method is successfully demonstrated through a classification example of four distinct latent fingerprints, using discrimination such as soft independent modeling of class analogy (SIMCA) and partial-least-squares discriminant analysis (PLS-DA). This demonstration develops an accuracy of more than 85% and is proven to be sufficiently robust. In addition, by laser-scanning analysis at a spatial interval of 125 ㎛, the overlapping fingerprints were separated as two-dimensional forms.

• Journal of Yeungnam Medical Science
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• v.38 no.2
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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.

• Journal of The Korean Association For Science Education
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• v.44 no.1
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• pp.1-9
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• 2024

The purpose of this study is to examine middle school students' environmental worldviews, focusing on the following: 'Technocentric (TC)', 'Ecocentric (EC)', and 'Sustainable Development (SD)' environmental worldviews. The instrument surveying the worldviews of middle school students comprised two components: 'natural environment' and 'human action & environment'. The 'natural environment' component consisted of four categories. These were the value of humans in nature, the value of natural environments, nature reigned by humans, and the equilibrium sustaining power of environmental ecosystems. The 'human action & environment' component also consisted of four categories. These were the depletion of energy & resources, technology development, economic growth, and the severity of environmental problems. The subjects were 376 middle school students (152 males and 224 females), who were selected from 10 middle schools, and they answered question items by themselves through an online survey system. They displayed more 'Sustainable Development environmental worldviews' and 'Ecocentric environmental worldviews' than 'Technocentric environmental worldviews'. Furthermore, the female students displayed more 'Sustainable Development environmental worldviews' than the males. Hence, it is necessary to implement educational approaches that address and relate to the sustainable development environmental worldviews of middle school students.

• Journal of Pharmacopuncture
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• v.14 no.1
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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.

• Journal of Korean Academy of Nursing
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• v.39 no.4
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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.

• Transactions of Materials Processing
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• v.21 no.7
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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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• v.38 no.2
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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)