• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.262.1-262.1
• /
• 2014

Lipid peroxidation induces functional deterioration of cell membrane and induces cell death in extreme cases. These phenomena are known to be related generally to the change of physical properties of lipid membrane such as decreased lipid order or increased water penetration. Even though the electric property of lipid membrane is important, there has been no report about the change of electric properties after lipid peroxidation. Herein, we demonstrate the molecular energy band change in red blood cell membrane through peroxidation by air-based atmospheric pressure DBD plasma treatment. Ion-induced secondary electron emission coefficient (${\gamma}$ value) was measured by using home-made gamma-focused ion beam (${\gamma}$-FIB) system and electron energy band was calculated based on the quantum mechanical Auger neutralization theory. The oxidized lipids showed higher gamma values and lower electron work functions, which implies the change of surface charging or electrical conductance. This result suggests that modified electrical properties should play a role in cell signaling under oxidative stress.

• 한국산학기술학회논문지
• /
• 제18권12호
• /
• pp.359-371
• /
• 2017

본 연구에서는 교원임용 시험을 준비하고 있는 기간제 교사들의 교직생활과 삶을 탐색하였다. 이를 위해 10명의 기간제 교사들을 대상으로 반구조화된, 일대일 면담을 진행하였고, 합의적 질적 연구 방법을 사용하여 자료를 분석하였다. 연구결과, 대부분의 참여자들은 경제적 필요를 충족시키고 자신의 꿈인 교사생활의 기쁨과 보람을 맛보며, 임용 시험에 실질적인 도움을 얻고자 기간제 교사직을 선택한 것으로 나타났다. 기간제 교사생활에서 경험하는 어려움으로는 학교 관리자로부터의 차별 대우가 가장 두드러졌으며, 이로 인한 자존감의 저하와 정체성의 혼란을 겪고 있는 것으로 파악되었다. 이러한 차별이 오히려 임용 시험 준비에 대한 강한 의지로 전환되어 참여자들은 안정되고 당당한 교사 신분을 얻기 위해 임용시험준비에 전념하고 있다고 진술하였다. 하지만, 시험준비 과정에서 부족한 공부시간, 끝없는 공부양, 다양한 삶의 역할 수행, 체력 저하, 난해한 시험 유형, 이전 실패경험에서 오는 불안감 등으로 상당한 스트레스를 경험하는 것으로 확인되었다. 연구결과를 토대로 향후 연구의 방향에 대해 제언하였다.

• 대한지역사회영양학회지
• /
• 제17권6호
• /
• pp.752-771
• /
• 2012

This study was conducted to investigate the effect of sodium reduction education program of a public health center on the blood pressure, blood biochemical profile and sodium intake of hypertensive adults. The program continued for 16 weeks with an 8-week nutrition education and an 8-week follow-up to forty two subjects, 6 males and 36 females aged 46 to 80 years. Subjects received nutrition education including lectures, activities, cooking classes and nutrition counseling. Physical fitness, management of stress, and nutrition counseling were provided during the follow-up. The program was evaluated three times, before and after the nutrition education, and after the follow-up. Systolic blood pressure (p < 0.0001) and diastolic blood pressure (p < 0.001) were decreased after completion of the program. Body weight (p < 0.005), percent body fat (p < 0.005) and body mass index (p < 0.001) were decreased, too. There were no significant differences in blood glucose, HDL-cholesterol and triglycerides, while elevated levels of total cholesterol (p < 0.001) and LDL-cholesterol (p < 0.001) appeared after the program completion. Decreased intakes of vitamin A (p < 0.05), ${\beta}$-carotene (p < 0.001) and sodium (p < 0.001) were observed. Consumption frequency of noodles, soups, stews, kimchi, fishes/shellfish, seasoned vegetables, and salted seafoods/pickles (p < 0.05~p < 0.001) were decreased, while that of all food groups were not changed during the follow-up. Total score of nutrition knowledge related to sodium intake and hypertension (p < 0.001), and that of dietary behavior associated with high sodium intakes were changed positively (p < 0.001) only during the nutrition education. This sodium reduction education program, including the follow-up study showed positive effects on the blood pressure, sodium intake, nutrition knowledge and dietary behavior of hypertensive adults.

• 폴리머
• /
• 제25권4호
• /
• pp.536-544
• /
• 2001

실험적 사실에 근거하여 고분자 유체의 점탄성 구성방정식에 빈번히 적용되어온 time-strain separability 가설의 타당성을 수학적 안정성 관점에서 분석한다. 안정성 조건으로는 방정식의 빠른 응답과 관련된 Hadamard 안정성과 소산 성질에 의하여 결정되는 소산 안정성이 있으며, asymptotic 분석을 이용한 결과 가설을 따르는 구성방정식은 Hadamard 또는 소산 불안정함이 증명되었다. 응력완화 실험에서 이미 관찰된 짧은 시간영역에서 time-strain separability의 가설이 적용되지 않는다는 사실은 본 결과와 일치한다. 따라서 separability를 구성방정식에 적용하는 것은 수학적 불안정뿐 아니라 열역학적 모순점을 나타내게 되며, 또한 실험에서도 그 타당성의 한계에 주의할 필요가 있다. 더욱이 damping 함수 역시 실제와는 무관한 가상적 값을 제공하므로 damping 함수의 사용은 긴 시간영역에서 응력완화 거동을 기술하기 위한 curve fitting 이상의 의미는 없다 하겠다.

• Safety and Health at Work
• /
• 제9권2호
• /
• pp.216-223
• /
• 2018

Background: Many studies have reported negative psychological or physical effects of emotional labor. Relationship between work-related musculoskeletal disorder and psychosocial factors has been reported. To manage organizational and psychosocial factors of musculoskeletal disorder with work place intervention among emotional laborers, the factors contributing to musculoskeletal pain must be identified and clarified. Methods: Data from the fourth Korean Working Conditions Survey was analyzed. Based on the questionnaire, we selected emotional laborers and included 3,979 participants, excluding participants whose variables were of interest to the researcher. Weight variable was applied. The association with musculoskeletal pain and psychosocial factors, such as workload, monotonous work, job control, social support, and job satisfaction, was investigated. Results: Univariate analysis demonstrated that there was a statistically significant relationship between social support, job satisfaction, and musculoskeletal pain. In multivariate analysis, job satisfaction showed a strong correlation with musculoskeletal pain at all sites. Social support was significantly associated with backache. Monotonous work seemed to reduce the pain in the neck and/or upper limbs. Job control and work intensity were not significantly associated with musculoskeletal pain. Conclusion: In this study, job satisfaction was significantly associated with musculoskeletal pain, and social support among the social psychological stressors could reduce musculoskeletal pain. However, unlike previously known, the presence of monotonous work resulted in reduced musculoskeletal pain. The results of this study will help to establish the direction of improvement of atmosphere in the workplace to prevent the musculoskeletal pain of emotional laborers.

• 대한가정학회지
• /
• 제17권3호
• /
• pp.23-34
• /
• 1979

Adequate intake of nutrients exert a profound influence on the physical and spiritual development of children. Thus, it is important to children and their mothers about nutrition and selection of nutritious foods. In order to underline the importance of nutrition for children, this study investigated and analyzed food habits of children expecially those in preschool ages, to obtain basic data to develop effective educational materials related to nutrition. dietary habits of 61 boys and 44 girls in the average age of six were surveyed through their mothers. Results therefrom are as follows : 1. Only 17 per cent of the mothers questioned replied that they considered the balance of diet in preparing meals, while 58.1% of the mothers gave precedence to the liking of their family . The lower the educational level of a mother , the higher her stress on the food preference of her family. 2. Seventy six of the mothers said they understand the basic food group , but only one mother displayed an accurate knowledge about it. 3. As for between meal eating , 82.9% took fruits, 68.6% milk, 35.2 bread, and 33.3% cookies. 4. Problems with food habits of children were : Unbalanced diet for 43.8% of children ,eating of snacks at irregular intervals for 26.7% and TV impact for 5.7%. 5. Children's food habits are greatly influenced by their parents, In the case of animal liver, 32.1 % of the children surveyed do not like to eat it, while 35.8% have never tasted it . 27.9% of children also do not like to eat cereals. Children's likes and dislikes with regarded to foods were influenced greatly by their parents. Thus, it is urgent to educate mothers about balanced diet and basic food group. Children will have to be taught to understand unfavorable effects of unbalanced diet so that they may correct their unsound food habits. This study also indicated the need for developing new cooking methods for those food items which are very liked by children to be a major cause of their unbalanced dietary habits.

• 한국재난정보학회 논문집
• /
• 제5권1호
• /
• pp.48-62
• /
• 2009

Bodyguards always perform their duty with psychological burdens in their mind, not only because security situations are developed in various forms dependent on the surrounding environments or circumstances, but because bodyguards only take follow-up actions while the criminal decides time, place, and style of every attack. Thus, in the security situation, it is not uncommon for bodyguards to experience muscle rigidity, uncontrollable emotional elevation, difficulty in concentration, negative perception, frustration and enervation, which are caused by continuous physical/mental burdens, stimulations by various interpersonal behaviors or minute environmental stimulants. In conclusion, the result of performing security duties is related in the first place with the degree of the bodyguard's potential, in the second place with the degree of training and efficiency. And the result can also be changed by the way they control their negative psychological state of the moment when they carry out the skills they acquired. Maximizing the performance of the bodyguards by helping them overcome these psychological factors may be facilitated by detecting their psychological factors, understanding the causes, and training them in applying appropriate measures for overcoming these factors. When these measures are applied, the positive perception is indispensable that duties of protecting clients can be carried out successfully. No single measure can be declared to be more effective than the other because the effect of each measure is expressed differently by the individual characteristics of the bodyguards. However, it is important to select and apply the measures most appropriate to the bodyguard. Besides, they should devote themselves to the training with persistence because efficient implement of the measures for overcoming psychological factors takes a lot of time.

• Journal of Dairy Science and Biotechnology
• /
• 제32권2호
• /
• pp.63-70
• /
• 2014

Automatic milking systems (AMS) have been increasingly introduced to Korean dairy farms. However, in comparison with conventional milking systems (CMS), some negative changes in milk quality are being observed. The use of AMS leads to an increase in milking frequency, which in turn might result in higher physical stress on the milk, possibly causing changes in the milk fat globule (MFG) membrane. Therefore, the purpose of this study was to examine the effect of the different milking systems on the milk quality, with a focus on milk fat properties. At the same time, we studied the effect of feeding the dairy cows with protected fat. Raw milk samples were taken monthly from individual cows as well as from bulk tanks at four AMS and four CMS dairy farms. We measured quality-related parameters such as MFG size distribution, free fatty acid content and composition, and acid values. Although most results showed no significant differences with regard to the milking system, we found a relatively high positive correlation between MFG size and milk fat content. Moreover, larger MFG size was observed in the milk when cows had been fed protected fat. The significantly higher (P< 0.05) free fatty acid content of milk observed under this experimental condition could be attributed to higher milking frequency as a result of using AMS.

• Journal of Korean Medical Science
• /
• 제33권50호
• /
• pp.320.1-320.8
• /
• 2018

Background: Muscle mass and muscle function are related to depressed mood in studies of adults. Like adults, Korean students are highly likely to suffer from decreased muscle mass due to social conditions. In this study, we evaluated the muscle mass status of Korean adolescents and assess the effect of muscle on depressive mood. Methods: A total of 1,233 adolescent boys and girls participants from the Korea National Health and Nutrition Examination Survey were enrolled in our study. Participants underwent dual-energy X-ray absorptiometry for assessment of appendicular muscle mass and completed questionnaires regarding depressed mood, stress, suicidal ideations, and attempts. Results: There was no difference in depressive mood according to muscle mass among boys (P = 0.634); girls with decreased muscle mass had a greater tendency for depressed mood compared to girls with optimal muscle mass (P = 0.023). After adjusting for age, waist circumference-to-height ratio, smoking status, alcohol consumption, frequency of physical activity, self-reported obesity, weight-loss efforts, and monthly household income, girls with low muscle mass (LMM) were 2.60 times more at risk of developing depression than girls with normal muscle mass (95% confidence interval [CI], 1.05-6.49; P = 0.040). This trend was similar for girls with LMM with obesity (95% CI, 1.00-11.97; P = 0.049). Conclusion: Adolescent girls who have insufficient muscle mass are more likely to report depressed mood than girls who have ideal muscle mass. Interventions for maintaining proper muscle mass are required.

• Biomolecules & Therapeutics
• /
• 제27권6호
• /
• pp.530-539
• /
• 2019

Brain aging is an inevitable process characterized by structural and functional changes and is a major risk factor for neurodegenerative diseases. Most brain aging studies are focused on neurons and less on astrocytes which are the most abundant cells in the brain known to be in charge of various functions including the maintenance of brain physical formation, ion homeostasis, and secretion of various extracellular matrix proteins. Altered mitochondrial dynamics, defective mitophagy or mitochondrial damages are causative factors of mitochondrial dysfunction, which is linked to age-related disorders. Etoposide is an anti-cancer reagent which can induce DNA stress and cellular senescence of cancer cell lines. In this study, we investigated whether etoposide induces senescence and functional alterations in cultured rat astrocytes. Senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal) activity was used as a cellular senescence marker. The results indicated that etoposide-treated astrocytes showed cellular senescence phenotypes including increased SA-${\beta}$-gal-positive cells number, increased nuclear size and increased senescence-associated secretory phenotypes (SASP) such as IL-6. We also observed a decreased expression of cell cycle markers, including PhosphoHistone H3/Histone H3 and CDK2, and dysregulation of cellular functions based on wound-healing, neuronal protection, and phagocytosis assays. Finally, mitochondrial dysfunction was noted through the determination of mitochondrial membrane potential using tetramethylrhodamine methyl ester (TMRM) and the measurement of mitochondrial oxygen consumption rate (OCR). These data suggest that etoposide can induce cellular senescence and mitochondrial dysfunction in astrocytes which may have implications in brain aging and neurodegenerative conditions.