• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.3
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• pp.168-175
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• 2020

Purpose: The purpose is to test and evaluate the physical properties of commonly used temporary restoration materials and newly emerged materials. Materials and Methods: Four groups of polymer materials were evaluated: Polymethyl methacrylate (PMMA) 2 groups, Polyetheretherketone (PEEK), Polycarbonate. Four physical properties were tested: surface hardness, bending strength, abrasion resistance during wear, wear behavior. The 3-axis bending strength and Vickers hardness test were measured using a universal testing machines respectively. The microstructure was observed with a scanning electron microscope and weight comparison was evaluated after 100,000 chewing tests using a chewing simulator. Kruskal wallis test was performed to evaluate statistical significance. Results: The four groups showed the highest flexural strength and Vickers hardness of PEEK, followed by PC, PMMA-H, PMMA-T. Microstructure observation also showed the least surface roughness in the PEEK group, followed by PC, PMMA-H, PMMA-T. Conclusion: PC is considered to have sufficient mechanical properties that can be applied to the manufacture of temporary teeth. However, further studies, such as biocompatibility, are considered to be necessary for practical clinical applications.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1096-1107
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• 2018

The purpose of this study was to investigate the effects of combined exercise on blood inflammatory factors, DHEA-s and arterial stiffness in elderly women. The subjects were 42 elderly females volunteers, aged 70 to 85 years, composed of the combined exercise group (n=21) and control group (n=21). The 60 minute combined exercise program(aquarobics 1 time/week, strength exercise 2 times/week) was performed 3 times per week for 12 weeks, and the intensity was progressively increased every 4 weeks(1-4 weeks: RPE 12 to 13, 5-8 weeks: RPE 13 to 14, 9-12weeks: RPE 14 to 15). The test data were analyzed by two-way repeated measures ANOVA, paired t-test, independent t-test and the alpha level of .05 was set for all tests of significance. As a result, the combined exercise for 12 weeks reduced the inflammatory response of elderly women, and DHEA-s was found to have a positive effect on aging hormone. The arterial stiffness decreased the central arterial blood pressure (systolic and diastolic), prevented the increase of the pulse pressure and the wave increase index, and decreased the pulse wave velocity. These results suggest that regular and continuous combined exercise may be recommended for the healthy aging and longevity of elderly women by inducing anti-inflammation effect and improving the aging hormonal function and the vascular health.

• Journal of Preventive Medicine and Public Health
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• v.21 no.2 s.24
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• pp.357-364
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• 1988

By implementing epoch-making policies for industrial promotion, the national economy has made a remarkable development. As a result of such economic growth, industrial accidents and occupational diseases have become a serious problem in Korean society. In the presidential order for the execution of the Korean Labor Standard Law, neuritis and other diseases stemming from health impairments due to vibrations in industrial processes are designated to be dealt with as vibration diseases. In the case of vibration disease, industrial accident compensation is not effectively paid. In order to investigate the vibration hazards of rock-drill operation, the authors studied the subjective symptoms and performed physical function tests on a total of 79 persons (vibration exposed group) who used rock-drills, and 39 persons (control group) who did not use rock-drills at anthracite mines. The results of the physical function test were as follosws : 1. The right hand was more affected by white finger than the left hand. 2. Independent variables such as duration of rock-drill operation, age, drinking and smoking were indentified as statistically significant factors for the occurrence of white finger. 3. In the pain sense threshold, the group with Raynaud's phenomenon showed a statistically higher level than that of the control group. 4. The skin temperature of the group with Raynaud's phenomenon was lower than that of the control group. The recovery time of skin temperature aftr cooling was delayed compared with the value of the control group.

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.127-133
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• 2024

The elbow joint is made up of three different bones. X-rays or other radiological exams are commonly used to diagnose elbow injuries or disorders caused by physical activity and external forces. Previous research on the elbow joint reported a new examination method that meets the imaging evaluation criteria in the tilt position by Z-axis elevation of the forearm. Therefore, this study aims to design an optimized instrument and develop an aid applicable to other upper extremity exams. After completing the 2D drawing and 3D modeling design, the final design divided into four parts was fabricated with a 3D printer using ABS plastic and assembled. The developed examination aid consists of a four-stage Z-axis elevation tilt angle function (0°, 5°, 10°, and 15°) and can rotate and fixate 360° in 1-degree increments. It was designed to withstand a maximum equivalent stress of 56.107 Pa and a displacement of 1.6548e-5 mm through structural analysis to address loading issues caused by cumulative frequency of use and physical utilization. In addition to X-ray exams of the elbow joint, the developed aid can be used for shoulder function tests by rotating the humerus and also be applied to MRI and CT exams as it is made of non-metallic materials. It will contribute to the accuracy and efficiency of medical imaging diagnosis through clinical applications of various devices and medical imaging exams in the future.

• Journal of Korean Academy of Nursing
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• v.29 no.2
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• pp.429-444
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• 1999

This study was performed to explore the effects of a dance therapy on physical and psychological characteristics in the elderly. The design of this study was a non-equivalent pre-post test experiment. The subjects consisted of elderly persons living in a facility located in Suweon and Bucheon. Fifty eight subjects, aged between 65 and 93 years who had normal cognition, sensory function, balance, and resting blood pressure. They underwent tests of balance, flexibility, muscle strength, depression, and anxiety as baseline data before dance therapy, and at 6th week and at the end of the 12nd week after following dance therapy. Twenty seven elderly persons were assigned to the experimental group and participated with the dance therapy between April and July, 1998. The dance therapy was developed by the author with the help of a dance therapist and a physiatrist. This therapy was based on the Marian Chace's dance therapy and Korean traditional dance with music. The dance therapy consists of 50 minutes session, 3 times a week for 12 weeks. One session was consisted of warming-up, expression, catharsis, sharing, and closing stage. The intensity of the dance therapy was at the 40 % of age-adjusted maximum heart rates. Data were analysed with mead standard deviation, Chi-square test, unpaired t-test, repeated measures ANOVA, and Bonferroni multiple regression using SAS program. 1. The results related to the physical characteristics were as follows : 1) The balance (standing on one leg, walking on the balancing bar), flexibility and muscle strength (knee extensor, knee flexor, ankle plantarflexor and dorsiflexor) of the experimental subjects significantly increased over time mere than that of the control subjects. 2) The experimental group had significantly higher score for balance, flexibility, muscle strength of knee extensor, and knee flexor than the control group at the 12nd week after dance therapy. 3) The experimental group had significantly higher score for muscle strength of ankle dorsiflexor and plantarflexor than the control group at the 6th week and the 12nd week after dance therapy. 2. The results related to psychological characteristics were as follows : 1) Scores of Geriatric Depression Scale, Hamilton Depression Rating Scale, and Zung's Self-rating Anxiety Scale of the experimental group were significantly decreased over time more than that of the control group. 2) The experimental group had significantly lower score for depression than the control group at the 12nd week after dance therapy. 3) The experimental group had significantly lower score for anxiety than the control group at the 6th week and the 12nd week after dance therapy. The findings showed that the dance therapy could be effective in improving the balances, flexibility, and muscle strength of lower limb, and effective in decreasing the depression and anxiety of the elderly. Additional merits of the dance therapy would be inexpensiveness, easy accessibility, and increasing interpersonal relationship. It can be suggested that the dance therapy is effective in the health promotion of the elderly.

• Journal of Korean Society on Water Environment
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• v.32 no.1
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• pp.36-45
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• 2016

Sand filters are widely used in infiltration systems to manage polluted urban runoff. Clogging, which is mainly caused by the deposition of sediments on the filter media, reduces the filter system's infiltration capacity, which further limits its lifespan and function. The physical, chemical and biological clogging characteristics of sand filter, therefore, need to be known for effective design and maintenance. Physical clogging behavior and variations in the characteristics of sand filters according to different media depths are examined in this paper. The variations were observed from laboratory column infiltration tests conducted in a vertical flow and fluctuating head condition. It can be seen that an increase in filter media depth results in a high sediment removal performance; however, it leads to a shorter lifespan due to clogging. In the choice of filter media depth to be used in field applications, therefore, the purpose of facilities as well as maintenance costs need to be considered. At all filter media depth configurations, premature clogging occurred because sediments of 100~250 μm clogged the top 15% of filter media depth. Thus, scrapping the top 15% of filter media may be suggested as the first operational maintenance process for the infiltration system.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.3
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• pp.399-407
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• 2012

To evaluate age and gender differences in the relation of cardiovascular risk factors, cognitive impairment, and subclinical carotid atherosclerosis from aged people using by a cross sectional method. Sixty-nine healthy elders living in the community who had not previously undergone carotid ultrasonography were included. We conducted life style surveys, and cognitive function tests including Korean-mini-mental state examination (K-MMSE) and clinical dementia rating-Korean. Various biomarkers from blood were assessed; fasting insulin-like growth factor-1, lipid-profile, high sensitivity C-reactive protein, total homocysteine, glucose, insulin, Homeostasis model assessment (HOMA) for insulin resistance index, vitamin B12, and folate level. Carotid intima-media thickness (C-IMT), and plaques were measured using carotid ultrasonography and aortic ultrasonography, a valid index of atherosclerosis. For the elderly subjects (aged 65-82 years), cognition impairment was more prevalent in females while subclinical atherosclerosis was more prevalentin males. Increased C-IMT has been kept in males, and C-IMT shows increasing trend and the peak at about 80 year-old in females with increasing age. The significant correlations between C-IMT and many vascular risk factors including age, triglyceride, abnormal homocysteinein male, and K-MMSE, insulin, HOMA index and abnormal aortic ultrasonography in female were different in each gender, with the exception of homocysteine (p<0.05). This data suggests that there were differences of age and gender characteristics in terms of subclinical atherosclerosis, cognitive impairment and vascular risk factors in community-living elders. Further larger and longitudinal studies across entire age are required to better understand the effects of risk factors on subclinical atherosclerosis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.605-614
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• 2016

This study was conducted to apply occupational reminiscence therapy (ORT) to the elderly diagnosed with mild cognitive impairment (MCI) who reside in the local community and determine its effects on cognitive functions, physical health, communication and interaction skills, and depression. The participants were elderly diagnosed with MCI who visited YW community health center on a regular basis and were randomly divided into an experimental group and a control group. The experimental group received eight one hour sessions of ORT once a week. Individual interviews were then conducted with the participants to determine if an event or activity had been commonly experienced, after which the program was modified and supplemented as necessary by referring to previous programs. The Content Validity Index (CVI) was calculated, and differences before and after ORT's were identified by paired t-tests. Moreover, the Mann-Whitney U-test was conducted to identify differences in variances between groups. Only participants in the experimental group (n=9) reported significant improvements in cognitive function, physical health status, communication and interaction skills, and depression when compared to those in the control group (n=9). Therefore, it is expected that ORT will be actively used as a non-pharmacological intervention for preventing dementia and improving the health of elderly persons with MCI.

• The Korean Journal of Food And Nutrition
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• v.29 no.3
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• pp.392-403
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• 2016

The purpose of this study was to investigate the relations between HbA1c level and health risk factor. For analysis, 330 elderly women aged 65 years and over were recruited in Jeonla province, Korea. The subjects were classified into two groups according to their HbA1c level; the diabetic group (HbA1c level${\geq}6.5%$, n=68, 20.6%) and control group (HbA1c level<6.5%, n=262, 79.4%). Demographic characteristics were collected, as well as information on physical measurements, blood tests for biochemical indicators, a health status and health-related life style, dietary behavior, favorite food groups, consumption frequency of food groups and nutrient intake. Educational level of the diabetic group was significantly lower than that of the control group. The height of the diabetic group was shorter, and percentage fat of the diabetic group was higher than those of the control group. In the diabetic group, the higher concentrations of creatinine and activity of alkaline phosphatase were found to be significantly unfavorable factors. Therefore, the diabetic group was assumed to be at risk of decreased liver and renal function. The self-rated health level of the diabetic group has a declining tendency, while the medicine intake was significantly higher than that of the control group, but there are no significant differences in visiting frequency of hospital and community health center. The distribution of physical activity showed a significant difference between the groups. Although there are no significant differences in nutrient intake, the diabetic group had relatively inferior nutrient intake of diet, especially vitamin C, as contrasted with the control group. In conclusion, the weight control and increasing physical activity may be effective in the prevention of the diabetes and continuous education and intervention by specialized nutritionists will be needed for diabetic patients. These results could be useful to plan effective strategies to increase the health-life expectancy and the prevention of the diabetes of Korean elderly people living in rural areas.

• Journal of Preventive Medicine and Public Health
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• v.30 no.1 s.56
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• pp.103-128
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• 1997

The object of this study is to evaluate the possibility of chemical-induced liver disorder among workers exposed to various chemicals and to classify the the liver function abnormalities by causes and to analyse the risk factors for each liver disorders. A cross-sectional study including questionnaire survey, physical examination, laboratory tests and ultrasonography of liver was conducted on 1,126 workers, 459 workers in a coal chemical plant(company A) and 667 workers in an insulation material manufacturing factory(company B). An industrial hygienist reviewed the chemicals used in both companies and evaluated the work environments to classify the workers by chemical exposure semiquantitatively. The results are as follows: 1. Of 459 workers in company A, 83 workers(18.1%) are classified as nonexposed, group 163(35,5%) as short-term exposure group, 155(33.8%) as intermediately exposed group and 58(12.6%) as long-term exposed group bared on the mean daily exposure to hepatotoxic chemicals evaluated by an industrial hygienist. Of 667 workers in company B, 484(72.6%) workers were classified as nonexposed and 183(35.5%) as exposed group. 2. Workers with SGOT level higher than 40 IU/l were (10.0%) in company A and 77(11.5%) in company 3, and those with SGPT level higher than 35 IU/l were 118(25.7%) in company A and 198(29.7%) in company B. The differences were not significant between companies and between exposure groups(p>0.05). Workers with $\gamma-GT$ level higher than 62 IU/l were 29(6.3%) in company A and 77(11.5%) in company B (p<0.01). The difference between exposure groups was not significant(p>0.05) within companies. Workers with liver function abnormalities(defined as SGOT higher than 40 IU/l or SGPT higher than 35 IU/l) were 338(30.0%) among 1,126 workers. Of 338 workers with live. function abnormalities 139(12.3%) had fatty liver by ultrasonography, 79(7.0%) had alcoholic liver(defined as workers with liver function abnormalities with weekly alcohol consumption greater than 280 g for more than 5 years), 54(4.8%) had hepatitis B, 12(1.1%) had hepatitis C and the other 114(33.7%) was not otherwise classified. Prevalences of alcoholic liver and fatty liver were significantly lower in company A(prevalence ratio 0.24 for alcoholic liver, p<0.001, prevalence ratio 0.76 for fatty liver, p<0.05) but prevalences of liver disorders between exposure groups within companies were not significant(p>0.05). 3. Summary prevalence ratios(SPR) of live. function abnormalities, fatty live. and other liver disorders, adjusted by age and company were not significantly higher in exposed group in any chemicals(p>0.05) but in some chemicals, SPRs were significantly lower. 4. On simple analysis of risk factors for liver function abnormalities, prevalence odds ratio(POR) of those with age between 30 and 39 was 1.54(p<0.01) and those with age ever 40 was 1.51(p<0.01). POR of those with histories of liver disorders and general anesthesia was 1.77(p<0.001) and 4.02 for those with overweight and 6.23 for those with obesity, defined by body mass index(p<0.001). 5. On logistic regression analysis, risk factors of liver function abnormality were fatty liver(POR 2.92 for grade 1, 12.15 for grade 2), presence of hepatitis B surface antigen(POR 3.62) and obesity(POR 5.38 for overweight and 16.52 for obesity). Presence of hepatitis B surface antigen(POR 0.18) was the only preventive facto. of fatty live. Company(POR 0.30) and obesity(POR 2.49 for overweight, 4.52 for obesity) were related to the alcoholic live. Obesity(POR 2.94 for overweight) was the only significant risk factor of hepatitis B and there was no significant risk factor for liver function abnormality not otherwise classified. It is concluded that the evidence of liver disorder related with chemical exposure is not evident in these factories. It is also postulated that fatty liver and alcoholic liver is most common causes of liver function abnormalities among workers and effort for weight control and improvement of life style should be done.