• Reproductive and Developmental Biology
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• v.35 no.2
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• pp.159-165
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• 2011

To explore the role of histone deactylase (HDAC) activation in an in vivo model of hypertrophy, we studied the effects of Trichostatin A (TSA). TSA subjected to thoracic aortic banding (TAB)-induced pressure stress in mice. In histological observations, TAB in treated mice showed a significant hypertrophic response, whereas the sham operation remained nearly normal structure with partially blunted hypertrophy. TSA treatment had no effect (measured as HW/BW) on sham-operated animals. TAB animals treated with vehicle manifested a robust ~50% hypertrophic response (p<0.05 vs sham). TAB mice treated with 2 mg/kg/day TSA manifested a blunted growth responses, which was significantly diminished (p<0.05) compared with vehicle-treated TAB mice. TAB mice treated with a lower dose of TSA (0.5 mg/kg/day) manifested a similar blunting of hypertrophic growth (~25% increase in heart mass). Furthermore, to determine activity duration of TSA in vitro, 1 nM TSA was added to H9c2 cells. Histone acetylation was initiated at 4 hr after treatment, and it was peak up to 18 hr, then followed by significantly reduced to 30 hr. We also analyzed the expression of p53 following TSA treatment, wherein p53 expression was elevated at 4 hr, and it was maintained to 24 hr after treatment. ERK was activated at 8 hr, and maintained till 30 hr after treatment suggesting an intracellular signaling interaction between TSA and p53 expression Taken together, it is suggested that HDAC activation is required for pressure-overload growth of the heart. Eventually, these data suggest that histone acetylation may be a novel target for therapeutic intervention in pressure-overloaded cardiac hypertrophy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4972-4980
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• 2014

This study examined the effects of teacher job stress and emotional intelligence on the turnover intent and job satisfaction. To this end, an early childhood teacher survey of 220 people using SPSS 9.0 data processing, analysis, and the independent variables were used to predict the dependent variable. Simple regression analysis and regression analysis of a follow-up examination were then performed. In the first study, the early childhood teachers' turnover intention due to job stress and job satisfaction revealed job stress to be a significant factor. The children's lack of leadership and administrative support work overload factors contributed to causes of stress. The turnover intention appeared to affect the mind. Second, early childhood teachers job satisfaction, job stress and turnover intention were affected by attempts to mediate the influence of job stress. Therefore, mediation plays a significant role. These results show that infant teacher duties affect the turnover intention and job satisfaction.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.3
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• pp.163-181
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• 2017

In the field of orofacial surgery, a red blood cell transfusion (RBCT) is occasionally required during double jaw and oral cancer surgery. However, the question remains whether the effect of RBCT during the perioperative period is beneficial or harmful. The answer to this question remains challenging. In the field of orofacial surgery, transfusion is performed for the purpose of oxygen transfer to hypoxic tissues and plasma volume expansion when there is bleeding. However, there are various risks, such as infectious complications (viral and bacterial), transfusion-related acute lung injury, ABO and non-ABO associated hemolytic transfusion reactions, febrile non-hemolytic transfusion reactions, transfusion associated graft-versus-host disease, transfusion associated circulatory overload, and hypersensitivity transfusion reaction including anaphylaxis and transfusion-related immune-modulation. Many studies and guidelines have suggested RBCT is considered when hemoglobin levels recorded are 7 g/dL for general patients and 8-9 g/dL for patients with cardiovascular disease or hemodynamically unstable patients. However, RBCT is occasionally an essential treatment during surgeries and it is often required in emergency cases. We need to comprehensively consider postoperative bleeding, different clinical situations, the level of intra- and postoperative patient monitoring, and various problems that may arise from a transfusion, in the perspective of patient safety. Since orofacial surgery has an especially high risk of bleeding due to the complex structures involved and the extensive vascular distribution, measures to prevent bleeding should be taken and the conditions for a transfusion should be optimized and appropriate in order to promote patient safety.

• Fire Science and Engineering
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• v.33 no.5
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• pp.130-139
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• 2019

This study identified the level of task stress experienced by fire protection system management workers and analyzed the effects of task stress on job satisfaction and proposed future response. First, task stress according to background cause showed differences in relation to age, position, monthly salary, total career, license, and task, but there was no difference in relation to academic background. Second, of the sub-parameters of stress, physical environment, task demand, organizational system, lack of reward, and workplace culture have negative effects on job satisfaction as stress increases, while interpersonal relation conflict and job insecurity do not have any effect. In the future, it will be necessary to investigate the empirical causes of work overload and to study organization-level stress relief measures.

• Journal of the Korean Society of Safety
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• v.26 no.3
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• pp.69-74
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• 2011

Despite most of tasks in manufacturing, construction and agriculture, etc., were currently mechanized and automated, manual materials handling still existed in atypical working condition. In case of manual materials handling, repetitive work, inappropriate working posture, excessive force, contact stress might cause overload, which could lead to work-related musculoskeletal disorders and low back pains. On this basis, the goal of this study is to reveal the effects of various lifting postures of trunk angles and lower extremity postures on maximum holding time(MHT). Twenty two subjects were recruited from a university population. The experiment was designed by a combination of three trunk angle ($0^{\circ}$, $20^{\circ}$, $60^{\circ}$) and three lower extremity postures(straight, bent, kneeling). Before experimental trials, subjects performed MVC(maximum voluntary contraction) exertions in three trunk angles ($0^{\circ}$, $20^{\circ}$, $60^{\circ}$) to calculate 30%MVC at designated postures. In each trial, they were required to hold the handheld load(30%MVC) for a designated posture as long as they could. The results of MVC by trunk angles were measured in $0^{\circ}$ > $20^{\circ}$ > $60^{\circ}$ orders, but those of MHT measured in $20^{\circ}$ > $0^{\circ}$ > $60^{\circ}$ orders. These results showed that straight posture is the ideal working posture in work exerted a strong force for a short time, but the ability to work might be improved in the trunk angle $20^{\circ}$ in work required 30%MVC for a long time. Also, results of MVC and MHT by lower extremity postures measured in straight > bent > kneeling orders.

• Journal of the Korean Solar Energy Society
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• v.31 no.4
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• pp.80-86
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• 2011

Investigation of the effective soil thermal conductivity(k) is the first step in designing the ground loop heat exchanger(borehole) of a geothermal heat pump system. Another important factor is the borehole thermal resistance($R_b$). Thermal response tests offer a good method to determine the ground thermal properties for the total heat transport in the ground. This is done by supplying a constant heat power into a borehole heat exchanger. There are two methods to supply a constant heat power. One is to employ the electricity provided by Korea Electric Power Corporation(KEPCO). The other is to use electricity generated by a generator. In this study, the power supply regulation was found to reduce when the electricity generated by the generator was used. This is because the generator evaluated with the power supply characteristically reduces the power supply regulation between an overload and a complex using. But it sometimes occurs a power supply regulation in In-situ thermal response test. In this case getting of k,$R_b$ requires delay times and restored normal state. However, the effect of the delay times and restored normal state on the soil thermal conductivity and borehole thermal resistance is very small. Therefore it is possible to use a generally accepted delay times and restored normal state in the analysis. In this work, it is also shown that an acceptable range of ${\Delta}k$, ${\Delta}R_b$ for normal state and regulation state might be approximately 0.01-0.16W/m k, and -0.004-0.007m K/W, respectively. Thus, restored normal state of power supply regulation is valuable to recommend.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.139-145
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• 2019

This study investigates the factors of job stress from working environment of employees' in the IT relative industry and explore its effects on both job involvement and affective commitment. 15 companies and individuals(IT freelancers) working in Seoul and Gyeonggi Provence were chosen for this study. Data were collected for 4 weeks from May 27 to June 28, 2019. A total of 400 employees' were attended in this research and finally 352 samples were used for the empirical analysis. The result of this study showed that 'role ambiguity' factor and 'role conflict' factor among the job stress factors influence on job involvement. Moreover, all factors(overload, role ambiguity, role conflict) among job stress influence on affective commitment.

• BMB Reports
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• v.54 no.9
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• pp.476-481
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• 2021

Liver receptor homolog-1 (LRH-1) has emerged as a regulator of hepatic glucose, bile acid, and mitochondrial metabolism. However, the functional mechanism underlying the effect of LRH-1 on lipid mobilization has not been addressed. This study investigated the regulatory function of LRH-1 in lipid metabolism in maintaining a normal liver physiological state during fasting. The Lrh-1^f/f and LRH-1 liver-specific knockout (Lrh-1^LKO) mice were either fed or fasted for 24 h, and the liver and serum were isolated. The livers were used for qPCR, western blot, and histological analysis. Primary hepatocytes were isolated for immunocytochemistry assessments of lipids. During fasting, the Lrh-1^LKO mice showed increased accumulation of triglycerides in the liver compared to that in Lrh-1^f/f mice. Interestingly, in the Lrh-1^LKO liver, decreases in perilipin 5 (PLIN5) expression and genes involved in β-oxidation were observed. In addition, the LRH-1 agonist dialauroylphosphatidylcholine also enhanced PLIN5 expression in human cultured HepG2 cells. To identify new target genes of LRH-1, these findings directed us to analyze the Plin5 promoter sequence, which revealed -1620/-1614 to be a putative binding site for LRH-1. This was confirmed by promoter activity and chromatin immunoprecipitation assays. Additionally, fasted Lrh-1^f/f primary hepatocytes showed increased co-localization of PLIN5 in lipid droplets (LDs) compared to that in fasted Lrh-1^LKO primary hepatocytes. Overall, these findings suggest that PLIN5 might be a novel target of LRH-1 to mobilize LDs, protect the liver from lipid overload, and manage the cellular needs during fasting.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.74-87
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• 2020

Overloaded trucks are the main source that threatens road safety and directly affects the reduction of pavement life. The On-board truck scale is the only equipment that could prevent overloading by measuring and adjusting the loading weight before driving. Legislation is needed to encourage its installation so that the driver can prevent overloading. In this study, an on-board truck scale system was installed on 30 dump trucks for transporting construction waste, such as soil and aggregates, which are major loads of 36.55% for overloading, and the trucks were monitored remotely. The overload prevention effect was analyzed by comparing driving data for 1 month before distribution of the weight display app that can recognize the weight to the driver and 1 month after distribution. After installation, overloading could be 6.1% reduced, and the transportation efficiency could be increased by checking the weight provided from the On-board truck scale system.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.444-449
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• 2020

In this study, On-Board Truck Scale was installed on the construction waste collection / transportation vehicles to monitor the weight of the waste at all stages from generation to final treatment. It was performed as a case study of a construction waste control technology that can efficiently manage the total generating and recycling amount using real-time weight/location information obtained by the On-Board Truck Scale device. As a result of the study, it was confirmed that the total amount of construction waste can be monitored in real time, and a plan for efficient logistics transportation can be derived through the analysis of operation patterns by managing the real-time transport volume, transport distance, and transport time of the construction waste collection / transportation vehicles. It was confirmed that overloading can be prevented in advance by controlling the loading also.