• Journal of dental hygiene science
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• v.12 no.5
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• pp.525-534
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• 2012

Study the effect of stress factors and increases in stress at work on the changes in eating behavior and habits and the influence of these changes on the health of dental hygienists. Use the responses of 273 dental hygienists who work in or around the Seoul area after surveying them by post or face to face. The biggest reason for skipping breakfast was having no time (60.4%) and the most desired change in eating habits was over eating (33.0%) while 51.6% responded that they over ate or binge ate due to stress. The largest stress factor was work load 39.6% and subjects responded that after stress the amount of food consumed increased very much for 12.1%, very for 49.8%, indicating increased food consumption than usual. The group with the most job stress had a high level of self stress awareness (p<0.001), nervousness (p<0.01), back pains (p<0.001), optical fatigue (p<0.01), headache (p<0.01) and indigestion (p<0.01). The higher the job stress, the poorer the eating behavior was (p<0.01) and job stress was high for dental hygienists working in dental clinics with less than three dental hygienists (p<0.05). Low eating behavior scores could be seen in groups that took 4 night shifts per week (p<0.05). Job stress scores for high for groups with no break time during work (p<0.001) and these groups showed low eating behavior scores (p<0.01). Furthermore, if high levels of self stress awareness was present, job stress was very high (p<0.001) and eating behavior scores were the lowest (p<0.05). Job stress of dental hygienists impede the eating behavior and habits therefore has a negative influence on their health. There is a need for more efforts to solve this problem and thus maintain the health of dental hygienists.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.558-565
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• 2012

The purpose of this study was to work related musculoskeletal disorders are a major. Occupational disease of the dental care profession is no exception. The survey was self-reported questionars of 300 dental hygienists that 268 dental hygienists reply to self-reported survey. This study results are as follows: Subjects of research analyzing the degree of physical musculoskeletal disorders pain, shoulder 90.3%, neck 89.2%, leg 83.6%, 81.7% back, hand/wrist/fingers 75.7%, arm/elbow, according to 52.8%. Therefore the work province of the research object people the musculoskeletal disorders appeared different. Generally characteristic was taller dental hygienists lower back pain and were out of less weight, study subjects had neck and arm pain. 29~33 year-old age the shoulder, over the age of 34 the arm/elbow to be high (p<0.05). Working environment to become a career, the more hand/wrist/fingers and the pain increased (p<0.05). The neck, shoulders (p<0.05), arm (p<0.01), waist high in the 3~4 years experience. And leg/foot was in the 1~2 years experience. This increase in working hours had increased pain in the neck but the hand/wrist/finger pain in the small hours of experience in the high pain(p<0.01). Conclusion of the musculoskeletal disorders of the dental hygienists often than the average for this risk is recognized. When it occurs early in treatment can be simple, but time is left to revert to normal when you do not already. Therefore, maintaining proper posture and dental hygienists, pain or fatigue appeared to accumulate immediately treated continued efforts are needed.

• Journal of The Korean Ophthalmological Society
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• v.58 no.6
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• pp.706-711
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• 2017

Purpose: To analyze blinking patterns when watching an ultra-high definition (UHD) television and to compare the results between normal eyes and dry eyes. Methods: A total of 59 participants aged from 13 to 69 years were instructed to watch a colorful and dynamic video on a UHD television for 10 minutes. Before and after watching the UHD television, we measured the best corrected visual acuities, autorefraction, tear-break-up-time, degree of corneal erosion and conjunctival hyperemia via slit lamp biomicroscopy. In addition, questionnaires for the evaluation of eye fatigue and symptoms of a dry eye were completed. The definition of dry eye syndrome was that the tear-break-up-time of one of the eyes was less than 5 seconds, conjunctival injection, or marked corneal erosion. The number of blinks and the duration of blinking were both measured and analyzed at the early and late phases of video-watching. Results: After watching the UHD television in the normal eye group, the tear-break-up-time was significantly decreased (p < 0.001) and the degree of corneal erosion was significantly increased (p = 0.023). However, the subjective symptoms of participants were not aggravated (p = 0.080). There were no significant differences in blinking patterns in the dry eye group. On the other hand, in the normal eye group, the mean blinking time was significantly increased (p = 0.030). Conclusions: Watching an UHD television changes the tear-break-up-time, degree of corneal erosion, and blinking pattern in normal eyes, which may increase the risk of dry eye syndrome.

• Sleep Medicine and Psychophysiology
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• v.3 no.2
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• pp.32-42
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• 1996

Objectives : Upper airway resistance syndrome(UARS) is a sleep-related breathing disorder characterized by abnormal negative intrathoracic pressure during sleep. Abnormally increased negative intrathoracic pressure results in microarousal and sleep fragmentation which underlay UARS-associated complaints of daytime fatigue and sleepiness. Although daytime dysfunction in patients with UARS is comparable to that of sleep apnea syndrome, UARS has been relatively unnoticed in clinical setting. That is why UARS is apt to be excluded in diagnosing of sleep-related breathing disorders since its respiratory disturbance index and arterial oxygen saturation are within normal limits. The current study presents a summary of clinical and polysomnographic characteristics found in patients with UARS. The present study aims (1) to explore characteristics of patients diagnosed with UARS, (2) to characterize the polysomnographic findings of UARS patients, and (3) to enhance the understanding of UARS through those clinical and laboratory characteristics. Methods : This was a retrospective study of 20 UARS patients (male 15, female 5) and 30 obstructive sleep apnea (OSA) patients (male 21, female 9) at the Stanford Sleep Disorders Clinic. We diagnosed patients as having UARS when they met critenia, RDI < 5 characteristic findings of an elevated esophageal pressure($<-10\;cmH_2O$), frequent arousals secondary to an elevated esophageal pressure, and symptoms of daytime fatigue and sleepiness. We used polysomnographic value, which is standardized by Williams et al(1974), as normal control. Statiotical test were done with student t-tests. Results : (1) Mean age of UARS was $41.0\;{\pm}\;14.8$ years and OSA was $50.9\;{\pm}\;12.0$ years. UARS subject was significantly younger than OSA subject (p<0.05). (2) The total score of Epworth Sleepiness Scale (ESS) was UARS $9.7\;{\pm}\;6.3$ and OSAS $11.2\;{\pm}\;6.3$. There was no significant difference between two groups. (3) The mean body mass index was UARS $28.1\;{\pm}\;5.7\;kg/m^2$ and OSAS $32.9\;{\pm}\;7.0\;kg/m^2$. UARS had significantly lower meen body man index than OSAS subjects (p<0.05). (4) The polysomnographic parameters of UARS were not significantly different from those of OSA except RDI(p<0.001), $SaO_2$ (p<0.001) and slow wave sleep latency (p<0.05). (5) Compared with normal control, Total sleep time in UARS subjects was significantly shorter (p<0.001), sleep efficiency index was significantly lower (p<0.001), total awakening percentage was significantly higher (p<0.001), and sleep stage 1 (p<0.001) were significantly higher. (6) OSA patients showed poor sleep quality and distinct abnormal sleep architectures compared with normal control. Conclusions : Conclusions from the above results are as follows : (1) UARS patients were younger and had lower body mass index when umpared with OSA patients. (2) The quality of sleep and sleep architectures of the UARS and OSA patients are significantly different from those of normal control. (3) ESS scores and awakening frequencies of UARS are similar with those of OSA, suggesting that daytime dysfunction of UARS patients may be comparable to those of OSA patients. (4) The RDI and the $SaO_2$ which are important indicators in diagnosing sleep-related breathing disorders, of UARS subjects are close to normal value. (5) According to the the above results, we unclude that despite the absence of $SaO_2$ drops and the absence of an elevated number of apnea and hypopnea, subjects developed clinical complaints which were associated with laborious breathing, elevated Pes nadir, and frequently snoring. (6) Accordingly, we suggest including LIARS in the differential diagnosis list when sleep related breathing disorder is suspected clinically and overnight polysomnographic findings except snoring and frequent microarousal are within normal limits.

• Journal of Intelligence and Information Systems
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• v.28 no.1
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• pp.45-68
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• 2022

The central and local governments of the Republic of Korea provided information necessary for disaster response through wireless emergency alerts (WEAs) in order to overcome the pandemic situation in which COVID-19 rapidly spreads. Among all channels for delivering disaster information, wireless emergency alert is the most efficient, and since it adopts the CBS(Cell Broadcast Service) method that broadcasts directly to the mobile phone, it has the advantage of being able to easily access disaster information through the mobile phone without the effort of searching. In this study, the characteristics of wireless emergency alerts sent to Seoul during the past year and one month (January 2020 to January 2021) were derived through various text mining methodologies, and various types of information contained in wireless emergency alerts were analyzed. In addition, it was confirmed through the population mobility by age in the districts of Seoul that what kind of influence it had on the movement behavior of people. After going through the process of classifying key words and information included in each character, text analysis was performed so that individual sent characters can be used as an analysis unit by applying a document cluster analysis technique based on the included words. The number of WEAs sent to the Seoul has grown dramatically since the spread of Covid-19. In January 2020, only 10 WEAs were sent to the Seoul, but the number of the WEAs increased 5 times in March, and 7.7 times over the previous months. Since the basic, regional local government were authorized to send wireless emergency alerts independently, the sending behavior of related to wireless emergency alerts are different for each local government. Although most of the basic local governments increased the transmission of WEAs as the number of confirmed cases of Covid-19 increases, the trend of the increase in WEAs according to the increase in the number of confirmed cases of Covid-19 was different by region. By using structured econometric model, the effect of disaster information included in wireless emergency alerts on population mobility was measured by dividing it into baseline effect and accumulating effect. Six types of disaster information, including date, order, online URL, symptom, location, normative guidance, were identified in WEAs and analyzed through econometric modelling. It was confirmed that the types of information that significantly change population mobility by age are different. Population mobility of people in their 60s and 70s decreased when wireless emergency alerts included information related to date and order. As date and order information is appeared in WEAs when they intend to give information about Covid-19 confirmed cases, these results show that the population mobility of higher ages decreased as they reacted to the messages reporting of confirmed cases of Covid-19. Online information (URL) decreased the population mobility of in their 20s, and information related to symptoms reduced the population mobility of people in their 30s. On the other hand, it was confirmed that normative words that including the meaning of encouraging compliance with quarantine policies did not cause significant changes in the population mobility of all ages. This means that only meaningful information which is useful for disaster response should be included in the wireless emergency alerts. Repeated sending of wireless emergency alerts reduces the magnitude of the impact of disaster information on population mobility. It proves indirectly that under the prolonged pandemic, people started to feel tired of getting repetitive WEAs with similar content and started to react less. In order to effectively use WEAs for quarantine and overcoming disaster situations, it is necessary to reduce the fatigue of the people who receive WEA by sending them only in necessary situations, and to raise awareness of WEAs.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.2
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• pp.186-196
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• 2004

Purpose: Autoimmune hepatitis is a chronic inflammatory liver disease with unknown cause that is characterized by liver histology, circulating autoantibodies and increased levels of immunoglobulin G. Only sporadic reports are available on autoimmune hepatitis in children. The aim of this study was to evaluate the clinical, biochemical, and histological features, and the long-term outcome of autoimmune hepatitis in Korean children. Methods: We reviewed the medical records of 14 children diagnosed as having autoimmune hepatitis at Seoul National University Children's Hospital from 1990 to 2004, and analyzed clinical, biochemical, and histological features, and clinical outcomes. Results: Mean age at diagnosis was 9 years and 11 of the 14 children were female. Six children presented with acute hepatitis-like manifestations. Jaundice and fatigue were the most common symptoms. Other autoimmune diseases accompanied in 6 children. Anti-nuclear antibody was detected in 13 patients and anti-smooth muscle antibody was positive in 8. All 14 patients were type 1 autoimmune hepatitis. The main histologic findings were interface hepatitis, rosette formation, and cirrhosis. Clinical and biochemical features were improved in six patients treated with ursodeoxycholic acid. Eight patients were treated with corticosteroid alone or in combination with azathioprine and five of them are in biochemical remission. Conclusion: Autoimmune hepatitis is an inflammatory liver disease, which has a favorable long-term outcome if it is diagnosed and treated promptly. Therefore, autoimmune hepatitis should be suspected in children with chronic hepatitis of unknown etiology, especially in female patients who show hypergammaglobulinemia or some clinical features of autoimmune disease.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.4
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• pp.599-604
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• 1998

We have investigated Pt and $RuO_2$ as a bottom electrode for ferroelectric capacitor applications. The bottom electrodes were prepared by using an RF magnetron sputtering method. Some of the investigated parameters were a substrate temperature, gas flow rate, RF power for the film growth, and post annealing effect. The substrate temperature strongly influenced the surface morphology and resistivity of the bottom electrodes as well as the film crystallographic structure. XRD results on Pt films showed a mixed phase of (111) and (200) peak for the substrate temperature ranged from RT to $200^{\circ}C$, and a preferred (111) orientation for $300^{\circ}C$. From the XRD and AFM results, we recommend the substrate temperature of $300^{\circ}C$ and RF power 80W for the Pt bottom electrode growth. With the variation of an oxygen partial pressure from 0 to 50%, we learned that only Ru metal was grown with 0~5% of $O_2$ gas, mixed phase of Ru and $RuO_2$ for $O_ 2$ partial pressure between 10~40%, and a pure $RuO_2$ phase with $O_2$ partial pressure of 50%. This result indicates that a double layer of $RuO_2/Ru$ can be grown in a process with the modulation of gas flow rate. Double layer structure is expected to reduce the fatigue problem while keeping a low electrical resistivity. As post anneal temperature was increased from RT to $700^{\circ}C$, the resistivity of Pt and $RuO_2$ was decreased linearly. This paper presents the optimized process conditions of the bottom electrodes for memory device applications.

• Journal of Food Hygiene and Safety
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• v.16 no.1
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• pp.21-26
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• 2001

Risk assessment traditionally are conducted on individual chemicals; however, humans are exposed to multiple chemicals in daily life. The organophosphorus (OP) pesticides are considered in a single risk assessment because they act by a common mechanism of toxicity, and there is likely to be expose to multiple OP pesticides simultaneously or sequentially. The OP pesticides act by inhibiting the enzyme acetylcholinesterasc (AChE) and have available extensive database. AChE is widely distributed throughout the body, most importantly in the nervous system. Inhibition of AChE results in accumulation of acetylcholine in the nervous system that results in clinical signs of cholinergic toxicity, including increased salivation and lacrimation, nausea and vomiting, muscle fasciculation, lethargy and fatigue, among others. To conduct an exposure assessment for pesticides in the diet, we need to know the food consumption patterns of the populations, and the pesticide residue levels in the foods that are consumed. This study was conducted to identify cumulative dietary risk due to multiple OP pesticides that can be exposed through various foods. Total 22 food samples including cereals, vegetables and fruits were collected randomly two times from food markets in several sites (4 cities). The subjected foods were selected by regarding of highly consumed foods to general Korean people. The 12 OP pesticides including Acephate, Azinphos-methyl, Chlorpyrifos, and Diazinon were monitored. For the exposure assessment, general adult group of 60 kg body weight was regarded as target population and food consumption data suggested by Lee et al. (2000) were used as consumed value of individual food. Analyses of samples for OP pesticides have been carried out according to the multiclass multiresidue analysis method and acephate and methamidophos analysis method of Korea Food Code. In general the levels of OP pesticides found in the food samples were very low or not detected.

• Korean Journal of Psychosomatic Medicine
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• v.11 no.2
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• pp.196-204
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• 2003

Objectives: It is known that sedative hypnotics would make cross tolerance with alcohol and deteriorate quality of sleep in alcoholics. Light therapy is effective non-pharmacological intervention for sleep disturbance in circadian phase disorders, jet-lag, shift-work and age-related sleep disorders. Authors would investigate the effects of morning light therapy on sleep of patients with alcohol dependence during recovery state without withdrawal symptoms. Methods: 13 patients with alcohol dependence who have not any alcohol withdrawal symptom were recruited. Light therapy during 1 hour in the morning had been administered by 2500 Lux light box through serial 3 days. Sleep state of subjects were assessed by sleep log and the subjective satisfaction at sleep was by 100 mm visual analogue scale. Sleepiness, depressive mood, anxiety were evaluated by 100mm visual analogue scale at 8 AM, 2 PM and 8 PM. For assessment of performance ability that would be associated with sleepiness and vigilance, trail making test A, B and digit symbol substitution test were performed by two times on base line and 4th day. Univariate repeated-measures ANOVAs were performed for each measures except performance tests which were analysed by paired t-test. Results: Sleep latency and sleep efficiency were significantly improved with light therapy and satisfaction at sleep was. There was no significant difference in sleepiness at 2 PM with light therapy but sleepiness at 8 AM significantly decreased and at 8 PM increased. The time to complete Trail making test and digit symbol substitution test were significantly shortened at 4th day compared with baseline. Fatigue at 8 AM were not significantly changed with light therapy but at 2 PM and 8 PM significantly decreased. Depressive mood and anxiety were not significantly changed with light therapy. Conclusion: Although this study had some limitations, it showed that light therapy would be effective modality on sleep disturbance of patients with alcohol dependence who have recovered from alcohol withdrawal symptoms. It is proposed that short term light therapy could be used clinically for alcoholics with insomnia. In the future, long term controlled studies using more objective tools for sleep are required to further investigate the effect of light therapy in alcoholics.

• Journal of Life Science
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• v.28 no.5
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• pp.621-626
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• 2018

We introduced the physiological responses of aging, active aging and also suggest the impact of physical exercise on body health status and elderly immunity. In this purpose, we searched the Pub Med data base for the articles (include our experimental papers) and review papers having the terms 'Aging', 'Active aging' and 'Physical activity and elderly' in the title, published from 1999 until 2018. The results were as follows: Exercise training has been extensively studied about the reduction of inflammation, oxidative stress, disease, and aging in syndrome X patients and elderly. Combined and aerobic or resistance exercise training could reduce obesity, insulin resistance, type 2 diabetes and hypertension. Exercise training has been extensively studied in cancer settings as part of prevention or treatment strategies. From this research, regular exercise has the potential to target tumor growth through regulation of inflammation and immune responses such as lactate clearance, NK cell activation (innate immunity), activation of cytotoxic immune cells, T cell activation (adaptive immunity), and immune surveillance. However, Endurance physical activity not only induces thermogenesis and diverse sports injuries but also elicits mobilization and functional enhancement of monocytes, neutrophils (which is caused by the cytokine changes such as TNF-alpha, IL-1) whereas it suppresses cell mediated immunity causing to increased susceptibility to inflammation and infections like cough and URTIs (upper respiratory track infections) in young and especially in elderly people. Therefore, Strategies to prevent physical fatigue, sports injuries include avoid overtraining, Adequate recovery and various type of rest during and after physical activity and assuring adequate nutrition supplementation such as glutamine, vitamin B, vitamin C, carbohydrate, ion or berry-contain sports beverages is helpful in physically active elderly.