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An Evaluation of Various Synthetic Generations and Polycross Progenies in Winter Active Tall Fescue (Festuca arundinacea Schreb) - I. Summer Forage Phase (동기생육형(冬期生育型) 톨페스큐의 합성품종세대(合成品種世代)와 다계교배(多系交配) 후대검정(後代檢定)에 관(關)한 연구(硏究))

  • Kim, Dal Ung
    • Korean Journal of Agricultural Science
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    • v.2 no.2
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    • pp.341-356
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    • 1975
  • This study was carried out to evaluate three winter active synthetic varieties in a succeeding generations of improvement and polycross progenies of seven genotypes selected at the cool and wet climate of the Western Oregon, in their performance of the polycross progeny test comparing with a control variety, high yielding 'Fawn', at Daejon, Korea. Various plant and leaf characteristics, especially related to photosynthesis, and forage production during the first summer after the establishment were examined. The important conclusions of this study are summarized as follows: 1. The differences of leaf fresh weight among groups and control exhibit genetic differences. The a verage of leaf fresh weight of polycross progeny group was the heaviest and those of winter active synthetic varieties in the succeeding generations of improvement was heavier than variety 'fawn'. Within polycross progeny group the genotypes exhibit genetic differences for leaf dry weight. 2. The leaf area exhibited genetic differences among groups and control. The average of winter active synthetic varieties in a succeeding generation was larger than variety 'Fawn'. Those oi the polycross progeny group was the largest among groups and control. 3. Differences of specific leaf weight(S. L. W.) among and within varieties, genotypes and control were not significant. Further investigation in this respect is necessary through the study of the diurnal change in S. L. W. 4. Differences of leaf width among groups and control exhibited genetic differences. The average leaf width of winter active varieties was larger than those of 'Fawn' variety. And those of polycross progenies of genotypes was the largest. 5. Plant height of 'fawn' variety in the first measurement was higher than those of winter active tall fescue varieties and genotypes. The deviation in plant height among polyeross progenies of seven genotypes gave a great deviation. The regrowth ability of plant height was not different suggesting that this characteristics was about the same among and within groups and control. 6. Plant width, spreading ability, improved through the succeeding generations of the improvement of the winter active synthetic varieties for the first measurement. Differences of plant width at the second measurement among genotypes within polycross progeny group were big enough to show the genetic difference. 7. Tiller number of the winter active synthetic varieties and the average of genotypes in polycross progeny was more than those of the control 'Fawn' in the first measurement. On the second measurement, the differences of tiller number appeared among three synthetic varieties indicating improvement, and there were genetic differences among seven genotypes in polycross progeny test. 8. Forage yield on the first cutting showed a considerble improvement of forage yield in the more advanced generation of synthetic varieties and genetic differences among seven genotypes in the polycross progeny test. The average of polycross progeny group was higher than those of the control or three winter active varieties. It was suggested that we could make a further improvement for the forage yield. 9. The regrowth ability of these winter active varieties and genotypes was about the same capacity at least on the measurement of the regrowth in forage yield and plant height during summer. 10. On the whole, the averages of the polycross progeny group was in the highest value and those of synthetic varieties were higher than the control variety, 'Fawn', for the most characteristics except S. L. W. and the plant height on the first measurement even though the differences were not always significant. And there were genetic differences among seven gentypes in their performance of the polycross progeny. 11. Although it was not always sgnificant, the most advanced winter active variety, '1002', had in the highest value for all plant characteristics and forage yield measurements than the other two varieties, '1001'. 12. The results of the association study among various characteristics were quite agreeable and would be useful in the selection of desirable genotypes for the development of a better variety.

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Dosimetric Effect on Selectable Optimization Parameters of Volumatric Modulated Arc Therapy (선택적 최적화 변수(Selectable Optimization Parameters)에 따른 부피적조절회전방사선치료(VMAT)의 선량학적 영향)

  • Jung, Jae-Yong;Shin, Yong-Joo;Sohn, Seung-Chang;Kim, Yeon-Rae;Min, Jung-Wan;Suh, Tae-Suk
    • Progress in Medical Physics
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    • v.23 no.1
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    • pp.15-25
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    • 2012
  • The aim of this study is to evaluate plan quality and dose accuracy for Volumetric Modulated Arc Therapy (VMAT) on the TG-119 and is to investigate the effects on variation of the selectable optimization parameters of VMAT. VMAT treatment planning was implemented on a Varian iX linear accelerator with ARIA record and verify system (Varian Mecical System Palo Alto, CA) and Oncentra MasterPlan treatment planning system (Nucletron BV, Veenendaal, Netherlands). Plan quality and dosimetric accuracy were evaluated by effect of varying a number of arc, gantry spacing and delivery time for the test geometries provided in TG-119. Plan quality for the target and OAR was evaluated by the mean value and the standard deviation of the Dose Volume Histograms (DVHs). The ionization chamber and $Delta^{4PT}$ bi-planar diode array were used for the dose evaluation. For treatment planning evaluation, all structure sets closed to the goals in the case of single arc, except for the C-shape (hard), and all structure sets achieved the goals in the case of dual arc, except for C-shape (hard). For the variation of a number of arc, the simple structure such as a prostate did not have the difference between single arc and dual arc, whereas the complex structure such as a head and neck showed a superior result in the case of dual arc. The dose distribution with gantry spacing of $4^{\circ}$ was shown better plan quality than the gantry spacing of $6^{\circ}$, but was similar results compared with gantry spacing of $2^{\circ}$. For the verification of dose accuracy with single arc and dual arc, the mean value of a relative error between measured and calculated value were within 3% and 4% for point dose and confidence limit values, respectively. For the verification on dose accuracy with the gantry intervals of $2^{\circ}$, $4^{\circ}$ and $6^{\circ}$, the mean values of relative error were within 3% and 5% for point dose and confidence limit values, respectively. In the verification of dose distribution with $Delta^{4PT}$ bi-planar diode array, gamma passing rate was $98.72{\pm}1.52%$ and $98.3{\pm}1.5%$ for single arc and dual arc, respectively. The confidence limit values were within 4%. The smaller the gantry spacing, the more accuracy results were shown. In this study, we performed the VMAT QA based on TG-119 procedure, and demonstrated that all structure sets were satisfied with acceptance criteria. And also, the results for the selective optimization variables informed the importance of selection for the suitable variables according to the clinical cases.

Detrended Fluctuation Analysis of Sleep Electroencephalogram between Obstructive Sleep Apnea Syndrome and Normal Children (소아기 수면무호흡증 환자와 정상 대조군 수면 뇌파의 탈경향변동분석)

  • Kim, Eui-Joong;Ahn, Young-Min;Shin, Hong-Beom;Kim, Jong-Won
    • Sleep Medicine and Psychophysiology
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    • v.17 no.1
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    • pp.41-49
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    • 2010
  • Unlike the case of adult obstructive sleep apnea syndrome (OSAS), there was no consistent finding on the changes of sleep architecture in childhood OSAS. Further understanding of the sleep electroencephalogram (EEG) should be needed. Non-linear analysis of EEG is particularly useful in giving us a new perspective and in understanding the brain system. The objective of the current study is to compare the sleep architecture and the scaling exponent (${\alpha}$) from detrended fluctuation analysis (DFA) on sleep EEG between OSAS and normal children. Fifteen normal children (8 boys/7 girls, 6.0${\pm}4.3$2.2 years old) and twelve OSAS children (10 boys/2 girls, 6.4${\pm}4.3$3.4 years old) were studied with polysomnography (PSG). Sleep-related variables and OSAS severity indices were obtained. Scaling exponent of DFA were calculated from the EEG channels (C3/A2, C4/A1, O1/A2, and O2/A1), and compared between normal and OSAS children. No difference in sleep architecture was found between OSAS and normal controls except stage 1 sleep (%) and REM sleep latency (min). Stage 1 sleep (%) was significantly higher and REM latency was longer in OSAS group (9.3${\pm}4.3$4.3%, 181.5${\pm}4.3$59.9 min) than in controls (5.6${\pm}4.3$2.8%, 133.5${\pm}4.3$42.0 min). Scaling exponent (${\alpha}$) showed that sleep EEG of OSAS children also followed the 'longrange temporal correlation' characteristics. Value of ${\alpha}$ increased as sleep stages increased from stage 1 to stage 4. Value of ${\alpha}$ from C3/A2, C4/A1, O1/A2, O2/A1 were significantly lower in OSAS than in control (1.36${\pm}4.3$0.05 vs. 1.41${\pm}4.3$0.04, 1.37${\pm}4.3$0.04 vs. 1.41${\pm}4.3$0.04, 1.37${\pm}4.3$0.05 vs. 1.41${\pm}4.3$0.05, and 1.36${\pm}4.3$0.07 vs. 1.41${\pm}4.3$0.05, p<0.05). Higher stage 1 sleep (%) in OSAS children was consistent finding with OSAS adults. Lower $'{\alpha}'$ in OSAS children suggests decrease of self-organized criticality or the decreased piling-up energy of brain system during sleep in OSAS children.

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Analysis of Perception of School Foodservice Facilities and Utilities in Gyeongnam Area by School Nutrition Teachers (Dietitians) -Comparison of School Foodservice Facilities and Improvement of Utilities in Schools- (경남지역 영양(교)사의 급식시설 설비에 대한 인지도 분석 -학교급식시설 현대화 사업 완료 학교와 미완료 학교의 비교를 중심으로-)

  • Jeon, Young;Kim, Hyun-Ah
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.9
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    • pp.1447-1456
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    • 2014
  • The purpose of this study was to compare perception of school foodservice facilities and utilities in dietitians and school nutrition teachers in the Gyeongnam area between schools that improved foodservice facilities and utilities versus those who did not. From July 23 to Aug 31, 2012, 391 questionnaires were distributed, and 289 questionnaires were obtained. A total of 275 questionnaires were used for the final analysis, excluding improper ones. The results of this study were as follows. First, among 275 schools, 90 schools (32.7%) improved school foodservice facilities and utilities while 175 schools (67.3%) did not. Second, schools with improved facilities had a more well-equipped receiving room (P<0.01), preparation room (P<0.001), dishwashing room (P<0.001), storage room for supplies (P<0.001), rest-room for school foodservice employees (P<0.05), locker room (P<0.01), shower room (P<0.001), laundry room (P<0.001), boiler room (P<0.05), and room for serving cart (P<0.05) than schools with no improvement. Third, total perception score of school foodservice facilities area from schools with improved facilities (1.71) was significantly higher than that (1.60) of school without improvement (P<0.001). Fourth, total satisfaction (3.32) of school foodservice facilities and utilities in school with improved facilities was significantly higher than that (2.62) of schools without improvement (P<0.01). Fifth, schools with improved facilities had a better equipped of floor (P<0.05), entrance (P<0.001), drain (P<0.001), water supply (P<0.01), lighting (P<0.001), hand washing (P<0.001), foodservice management room (P<0.001), locker room (P<0.001), rest-room and shower room (P<0.001), and preparation room (P<0.001) than schools without improvement. However, there was no significant difference in terms of walls and ceilings, windows, ventilation, and storage. In conclusion, school foodservice facilities and utilities improvement should conducted as soon as possible.

Relationships between Eating Behavior, Dietary Self-Efficacy, and Nutrition Knowledge of Elementary School Students by Food Service Type in Gangwon Province (강원지역 초등학생들의 급식유형(도시형, 농어촌형 및 도서벽지형) 별식행동과 식이자기효능감 및 영양지식과의 관계)

  • Won, Hyang-Rye;Shin, Gi-Beum
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.5
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    • pp.638-646
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    • 2012
  • The purpose of this study was to find a relationship between eating behavior, dietary self-efficacy and nutrition knowledge by comparing these items in elementary school students according to food service type. The survey was made through a questionnaire from 759 students in the 6th grade of elementary school in 39 Gangwon Province. The average score of eating behaviors according to food service type was highest for urban type, followed by agri-fishery type, and finally remote island and country type, for the questions asking about the application of nutrition knowledge and the frequency of eating out. The average score of nutrition knowledge according to food service type showed significant differences for the questions about eating snacks before going to sleep and weight increase as well as calorie comparisons between foods. For the correlation of eating behavior, dietary self-efficacy and nutrition knowledge, the agri-fishery type showed positive in all of the three items with significant differences. In the remote island and country type, there was a positive relationship between nutrition knowledge and dietary self-efficacy, and between eating behavior and dietary self-efficacy. However, there was no significant difference of correlation between nutrition knowledge and eating behavior. In order to confirm the predictable variables for eating behavior, a regression analysis was made by injecting variables in every stage with independent variables of dietary self-efficacy and nutrition knowledge, which showed a significant relationship with eating behavior. The results showed that, in the urban type, dietary self-efficacy and nutrition knowledge affected the eating behavior and, in the agriculture type and the remote island and country type, only dietary self-efficacy affected the eating behavior.

A Study on the Current Status of Prescribed Drugs in Oriental Health Insurance and their Improvement (한방건강보험 약제 투약 실태 및 활성화 방안 연구)

  • Kwon, Yong-Chan;Yoo, Wang-Keun;Seo, Bu-Il
    • The Korea Journal of Herbology
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    • v.27 no.2
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    • pp.1-16
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    • 2012
  • Objective : To investigate the current status of prescription drugs in Oriental medical institutes and to draw up a future plan for the revitalization of Oriental medical health insurance, this survey has been performed. Method : The survey has been made with 321 doctors working at Oriental medical institutes in Daegu and Kyungbuk areas for a period of 3 month from June 1, 2010 until September 1, 2010. Result : 1. When it comes to the current status of the use of herbal drugs in Oriental Health insurance, most of doctors surveyed prescribe insurance drugs, and they prescribe insurance drugs to patients, who are less than 20% of total patients visiting their clinics. 2. The awareness of Herbal Health Care Drugs is investigated. When it comes to the understanding of the difference between insurance drugs(powder type drugs) and granular type drugs, doctors admit that they differ only in one aspect, whether or not their being covered by health insurance. Based on the survey results on the understanding of insurance coverage of granular type drugs, doctors, even though they long for granular type drugs to be accepted as insurance drugs, are worrying whether the number of outpatients might dwindle due to increased insurance co-payments. They also point out that the biggest obstacles in the expansion of the granular type drugs as insurance drugs are the lack of understanding of the government and the objection of the Health Insurance Review and Assesment service (HIRA) for fear of increased insurance claims. 3. Upon investigation on Oriental medicine doctors' understandings of herbal pharmaceutical industry, it is found that doctors' responses on pharmaceutical industry are not all positive ones('new product development and neglect of R&D infrastructure' and 'smallness of industry'). When it is investigated what area needs the greatest improvement in herbal pharmaceutical industry, 'securing sufficient capital, good manufacturing, and strengthening quality control', is the highest. 4. When it is asked what are the most needed in order to improve herbal health insurance medicine, responses such as 'the increase in the accessibility to and the utilization of Oriental medical clinics through the diversification of the means of prescriptions', 'the improvement of insurance benefits(cap adjustments)', 'increase the proportion of high quality medicinal plants', 'the ceiling of co-payments(deductible) at 20,000 won or more', 'expansion of the choices of formulations', 'formulational expansions of tablets and pills', and finally 'admittance and expansion of granular type drug as insurance drug' are the highest. 5. Upon investigating the general characteristics of the current status of the usage of Oriental health care herbal drugs, the followings are observed. First, the frequency of use of health insurance drugs by the doctors who use health insurance with general characteristics shows similar differences in case of total monthly sales amount (p<0.001), average number of daily patients (p<0.05). Secondly, as to the willingness of the expanded usage of insurance drugs, similar differences are observed in case of total monthly sales amount (p<0.05). 6. Upon investigating the general characteristics of the perception of Herbal health care drugs, the followings are observed. First, inspecting general characteristics and insurance claims due to increased co-payments(deductible amount) reveals similar differences in case of working period (p<0.01) and in case of total monthly sales amount (p <0.01). Secondly, inspecting general characteristics and the obstacles that hinder granular type drugs from being accepted as health care insurance drugs shows similar differences in case of working period (p<0.05). 7. Upon investigating the general characteristics of the understanding of Oriental Herbal pharmaceutical companies, the followings are observed. First, opinions on the general characteristics of pharmaceutical companies, when examined with variance analysis, shows similar differences in case of total monthly sales amount (p<0.05). Secondly, when opinions are examined on general characteristics and the problems of herbal pharmaceutical companies, similar differences are found in case of working period (p<0.01) and in case of total monthly sales amount (p<0.001). Lastly, opinions on the general characteristics and reforms of pharmaceutical companies, similar differences are observed in case of working period (p<0.001). 8. Upon investigating the general characteristics of the improvement of insurance Herbal drugs, the followings are observed. First, regarding general characteristics and insurance benefits, similar differences are observed in case of working period (p<0.05), in case of total monthly sales amount (p<0.05), and in case of average number of daily patients (p<0.01). Secondly, opinions on the general characteristics and the needs for the improvement of Herbal insurance drugs are examined in 5 different aspects, which are the approval of granular type drugs as insurance drugs, the expanded practices of the number of prescription insurance drugs, the needs of a variety of formulations, the needs of TFT of which numbers of Oriental medical doctors are members for the revision of the existing system, and the needs of adjusting the current ceiling of the fixed amount and the fixed rate. When processed by the analysis of variance, the results show similar differences in case of average number of daily patients (p<0.01). Conclusion : From the results of this study the first measures to take are, to reform overall insurance benefit system, including insurance co-payment system(fixed rate cap adjustment), to expand the number of the herbal drugs to be prescribed matching with insurance benefit accordingly, and to revitalize herbal medicine insurance system through the change of various formulations. In addition, it is recommended to improve the effectiveness of herbal medicine by making plans to enhance the efficacy of herbal medicine and by enabling small pharmaceutical companies to outgrow themselves.

A Study on Farmer's Syndrome and Its Risk Factors of Vinyl House Worker and Farmer in a Rural Area (일부 농촌지역 비닐하우스 재배자들의 농부증 실태와 관련요인)

  • Lee, In-Bae;Lee, Yeon-Kyeong;Chang, Sung-Sil;Lee, Sok-Goo;Cho, Young-Che;Lee, Dong-Bae;Lee, Tae-Yong
    • Journal of agricultural medicine and community health
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    • v.24 no.1
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    • pp.13-33
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    • 1999
  • The aim of this study was to investigate fatigue scores, physical complaints, farmer's syndrome and to find out its risk factors among farmers. The questionnaire survey was conducted to 177 vinyl house workers and 213 farmers who lived in Chongyang gun of Chungnam province from February 24 to March 15, 1998. The obtained main results were followings; 1. The fatigue scores were not significantly different between vinyl house workers and farmers. The fatigue scores were higher in female group, lower education group, shorter sleep hours group(under 8 hours), nonsmoker, nondrinker group than otherwise groups. There was not statistically significant difference between the mean fatigue scores and age, eating habit and body mass index. Duration of farming years in vinyl house and farming area and number of farming workers in farmers family showed a slight relationship with the fatigue score. 2. Health scores were not different between vinyl house workers and farmers. The health states was poorer in female group, lower education group, shorter sleep hours group(under 8 hours), nonsmoker group, and nondrinker group than otherwise groups by health scores. Health scores were not related with age, eating habit and body mass index. 3. The proportion of farmer's syndrome was 49.1% in vinyl house workers and 52.1% in farmers. That was higher in female than in male and the higher proportion was found in the lower education group of vinyl house workers and farmers. The proportion of farmer's syndrome was higher in the group of smoker, alcohol drinkers and over or under weight in vinyl house workers, but did not differ in those of farmers. 4. By multiple logistic regression, sex and sleep hours were risk factors affecting to farmer's syndrome. Odds ration for female group was 2.53 (reference group was male) and that for over 8 sleep hours group was 0.74 (reference group was under 8 sleep hours group). 5. The chief complaints by CMI were "I am difficult to work due to aching the back and the limbs", "I feel prickle pain in the limbs", "I sometimes have a twinge in the limbs", "I am not quite well as having a pain in the limbs", "I feel weaker grasping power than before" in both of vinyl house workers and farmers. Vinyl house workers more frequently pointed out skin darkening, skin disease and hemorrhoids than farmers. 6. According to correspondence analysis, skin disease of vinyl house workers was related to vinyl house farmers and digestive and general symptom was associated with male and endocrinological and muscular symptom was associated with female in vinyl house workers. And it revealed that farmer's syndrome was highly related with female and farmers relatively. By the above results, the fatigue scores, perceive health and farmer's syndrome did not much differ in two groups, but aged female farmers should be considered as female farmers represented higher fatigue score, farmers syndrome and poorer perceive health than male farmers in addition to farmer's syndrome was increased with ageing process. Also feeble but distinguished symptoms which might be due to working environment were observed especially in vinyl house workers and that should be considered and investigated continuously.

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The Physical and Social Disability of Aged Persons Who Live Alone in Goksung Area (곡성지역(谷城地域) 독거노인(獨居老人)의 신체적(身體的) 사회적(社會的) 능력장애(能力障碍)에 관(關)한 조사(調査))

  • Kim, Shin-Woel;Kim, Young-Lak;Ryu, So-Yeon;Park, Jong;Kim, Ki-Soon;Kim, Yang-Ok
    • Journal of agricultural medicine and community health
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    • v.24 no.2
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    • pp.245-268
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    • 1999
  • It is necessary that the old should have the physical and social ability to perform their daily life. This study is to grasp their degree of disability and problems and suggest their solutions. It surveyed the 87 old people over 65 years old from September 1st until September 30th, in 1997. The findings are as follows. 1) The activities of daily living(ADL) to find their degree of physical disability shows that their average performance ability is 75.9% of all the action while 24.1% of all the old people needs the others' help. As they get older and older, the aged drop off in their physical ability, which is related to a statistical sense (p<0.001). 2) The social disability shows that the aged have their great difference from 9.2% to 85.1% in their instrumental activities of daily living(IADL), intellectual ability and social role. 3) A simple analysis shows that the activities of daily living are, in a statistical sense, related to age(p<0.001), the use of elder's hall(p<0.001), the understanding degree of health(p<0.01) and so forth. 4) A simple analysis shows that the instrumental activities of daily living are, in a statistical sense, related to age(p<0.001), the degree of education(p<0.05), the life of leisure(p<0.001), the understanding degree of health and so forth. 5) A multivariate logistic regression analysis shows that the disability of daily living is related to age, the visit of elder's hall, the period of solitary living, instrumental activities of daily living is age and the visit of elder's hall, and social role is the visit of elder's hall and the decree of education, while intellectual activity has no related variables in a statistical sense.

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Psychophysiological Characteristics of Insomnia Patients Measured by Biofeedback System (바이오피드백을 이용하여 측정한 불면증 환자의 정신생리적 특징)

  • Huh, Sung-Young;Lee, Jin-Seong;Kim, Sung-Gon;Kim, Ji-Hoon;Jung, Woo-Young
    • Sleep Medicine and Psychophysiology
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    • v.22 no.2
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    • pp.70-76
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    • 2015
  • Background and Objectives: Insomnia is the most prevalent sleep disorder in the general population and is considered to be a disorder of hyperarousal. The aim of this study was to measure the psychophysiological responses in insomnia patients using a biofeedback system, and to compare them with results from normal healthy subjects. Materials and Methods: Eighty patients with primary insomnia (35 males and 45 females, average age $49.71{\pm}12.91years$) and 101 normal healthy controls (64 males and 37 females, average age $27.65{\pm}2.77$) participated in this study. Electromyography (EMG), heart rate (HR), skin conductance (SC), skin temperature (ST), and respiratory rate (RR) were recorded using a biofeedback system during 5 phases (baseline, stress 1, recovery 1, stress 2, recovery 2) of a stress reactivity test, and average values were calculated. Difference in values between the two groups in each corresponding phase was analyzed with independent t-test, and change in values across phases of the stress reactivity test was analyzed with paired t-test (all two-tailed, p<0.05). Results: Compared to normal controls, insomnia patients had higher EMG in all 5 phases (baseline : $7.72{\pm}3.88{\mu}V$ vs. $4.89{\pm}1.73{\mu}V$, t = -6.06, p<0.001 ; stress 1 : $10.29{\pm}5.16{\mu}V$ vs. $6.63{\pm}2.48{\mu}V$, t = -5.84, p<0.001 ; recovery 1 : $7.87{\pm}3.86{\mu}V$ vs. $5.17{\pm}2.17{\mu}V$, t = -5.61, p<0.001 ; stress 2 : $10.22{\pm}6.07{\mu}V$ vs. $6.98{\pm}2.98{\mu}V$, t = -4.37, p<0.001 ; recovery 2 : $7.88{\pm}4.25{\mu}V$ vs. $5.17{\pm}1.99{\mu}V$, t = -5.27, p<0.001). Change in heart rate across phases of the stress reactivity test were higher in normal controls than in insomnia patients (stress 1-baseline : $6.48{\pm}0.59$ vs. $3.77{\pm}0.59$, t = 3.22, p = 0.002 ; recovery 1- stress 1 : $-5.36{\pm}0.0.59$ vs. $-3.16{\pm}0.47$, t = 2.91, p = 0.004 ; stress 2-recovery 1 : $8.45{\pm}0.61$ vs. $4.03{\pm}0.47$, t = 5.72, p<0.001 ; recovery 2-stress 2 : $-8.56{\pm}0.65$ vs. $4.02{\pm}0.51$, t = -5.31, p<0.001). Conclusion: Psychophysiological profiles of insomnia patients in a stress reactivity test were different from those of normal healthy controls. These results suggest that the sympathetic nervous system is more highly activated in insomnia patients.

COMPARISON OF POLYMERIZATION SHRINKAGE AND STRAIN STRESS OF SEVERAL COMPOSITE RESINS USING STRAIN GUAGE (스트레인 게이지를 이용한 수종의 복합레진의 중합수축 및 수축응력의 비교)

  • Kim, Young-Kwang;Yoo, Seung-Hoon;Kim, Jong-Soo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.3
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    • pp.516-526
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    • 2004
  • Polymerization shrinkage of photoinitiation type composite resin cause several clinical problems. The purpose of this study was to evaluate the shrinkage strain stress, linear polymerization shrinkage, compressive strength and microhardness of recently developed composite resins. The composite resins were divided into four groups according to the contents of matrix and filler type. Group I : $Denfil^{TM}$(Vericom, Korea) with conventional matrix, Group II : $Charmfil^{(R)}$(Dentkist, Korea) with microfiller and nanofller mixture, Group III : $Filtek^{TM}$ Z250(3M-ESPE, USA) TEGDMA replaced by UDMA and Bis-EMA(6) in the matrix, and Group IV : $Filtek^{TM}$ Supreme(3M-ESPE, USA) using pure nanofiller. Preparation of acrylic molds were followed by filling and curing with light gun. Strain gauges were attached to each sample and the leads were connected to a strainmeter. With strainmeter shrinkage strain stress and linear polymerization shrinkage was measured for 10 minutes. The data detected at 1 minute and 10 minutes were analysed statistically with ONE-way ANOVA test. To evaluate the mechanical properties of tested materials, compressive hardness test and microhardness test were also rendered. The results can be summarized as follows : 1. Filling materials in acrylic molds showed initial temporary expansion in the early phase of polymerization. This was followed by contraction with the rapid increase in strain stress during the first 1 minute and gradually decreased during post-gel shrinkage phase. After 1 minute, there's no statistical differences of strain stress between groups. The highest strain stress was found in group IV and followed by group III, I, II at 10 minutes-measurement(p>.05). In regression analysis of strain stress, group III showed minimal inclination and followed by group II, I, IV during 1 minute. 2. In linear polymerization shrinkage test, the composite resins in every group showed initial increase of shrinkage velocity during the first 1 minute, followed by gradually decrease of shrinkage velocity. After 1 minute, group IV and group III showed statistical difference(p<.05). After 10 minutes, there were statistical differences between group IV and group I, III(p<.05) and between group II and group III(p<.05). In regression analysis of linear polymerization shrinkage, group II showed minimal inclination and followed by group IV, III, I during 1 minute. 3. In compressive strength test, group III showed the highest strength and followed by group II, IV, I. There were statistical differences between group III and group IV, I(p<.05). 4. In microhardness test, upper surfaces showed higher value than lower surfaces in every group(p<.05).

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