• Toxicological Research
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• v.31 no.1
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• pp.17-23
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• 2015

Excessive manganese (Mn) in the brain promotes a variety of abnormal behaviors, including memory deficits, decreased motor skills and psychotic behavior resembling Parkinson's disease. Hereditary hemochromatosis (HH) is a prevalent genetic iron overload disorder worldwide. Dysfunction in HFE gene is the major cause of HH. Our previous study has demonstrated that olfactory Mn uptake is altered by HFE deficiency, suggesting that loss of HFE function could alter manganese-associated neurotoxicity. To test this hypothesis, Hfe-knockout ($Hfe^{-/-}$) and wild-type ($Hfe^{+/+}$) mice were intranasally-instilled with manganese chloride ($MnCl_2$ 5 mg/kg) or water daily for 3 weeks and examined for memory function. Olfactory Mn diminished both short-term recognition and spatial memory in $Hfe^{+/+}$ mice, as examined by novel object recognition task and Barnes maze test, respectively. Interestingly, $Hfe^{-/-}$ mice did not show impaired recognition memory caused by Mn exposure, suggesting a potential protective effect of Hfe deficiency against Mn-induced memory deficits. Since many of the neurotoxic effects of manganese are thought to result from increased oxidative stress, we quantified activities of anti-oxidant enzymes in the prefrontal cortex (PFC). Mn instillation decreased superoxide dismutase 1 (SOD1) activity in $Hfe^{+/+}$ mice, but not in $Hfe^{-/-}$ mice. In addition, Hfe deficiency up-regulated SOD1 and glutathione peroxidase activities. These results suggest a beneficial role of Hfe deficiency in attenuating Mn-induced oxidative stress in the PFC. Furthermore, Mn exposure reduced nicotinic acetylcholine receptor levels in the PFC, indicating that blunted acetylcholine signaling could contribute to impaired memory associated with intranasal manganese. Together, our model suggests that disrupted cholinergic system in the brain is involved in airborne Mn-induced memory deficits and loss of HFE function could in part prevent memory loss via a potential up-regulation of anti-oxidant enzymes in the PFC.

• Korean Journal of Occupational Health Nursing
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• v.20 no.1
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• pp.55-64
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• 2011

Purpose: This study was to investigate the relationship between the level of emotional labor and occupational job stress of hospital nursing staff. Methods: The survey was conducted from Mar. to Oct. 2009 to collect data from clinical nurses (N=496). Results: The study showed that nurses without religion and those working in big-sized hospitals had higher scores in emotional labor, and those of 26~30 years old felt the highest stress in the occupational role. The same applied to the married, more work experienced, atheist and those working in big-sized hospitals. Unmarried, under educated nurses with less work experience working in the big-sized hospitals showed higher scores in personal strain. The scores of the personal resources depended on religion, work experience, marital status and position of their jobs. Emotional labor was positively correlated with an occupational role and personal strain, respectively, but the emotional labor, occupational role and personal strain were negatively correlated with personal resources respectively. Conclusion: Intervention program is required to reduce overload of nurse's role and to relieve physical and psychological strains of the under-30-age-group. Also, social support and rational/cognitive coping must be reinforced.

• 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.

• Proceedings of the Safety Management and Science Conference
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• 2010.11a
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• pp.349-355
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• 2010

EPCIS(EPC Information Services) system is a core component of EPCglobal Architecture Framework offering information of the freights, the time of awareness and the location of awareness on the EPCglobal Network. The role of EPCIS is to exchange information based on EPC. There are four kinds of event data which are object event data, aggregation event data, quantity event data, and transaction event data. These EPCIS events data are stored and managed in EPCIS repository. This paper leads to separate a in-out data overload of integrated EPCIS event and suggests the method to effectively manage EPCIS repository for exchanging data smoothly. In order to verify a effectiveness, we measure the performance of the system using a simple testing simulation by comparing existing method and suggested method.

• Journal of the Korean Home Economics Association
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• v.41 no.2
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• pp.93-106
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• 2003

The purpose of this study was to investigate job stressors, job stress symptoms, and job performance of workers in fashion industry. The data were obtained from questionnaire completed by 529 workers who were employed in textile or clothing manufactures located in Seoul, Daegu, Busan, and Masan area. The SPSS package was used for data analysis which included frequency, mean, correlation, and factor analysis. Job stressors consisted of environmental related stressors, job related stressors(task characteristics and role characteristics) and organization related stressors(organization climate and career development). Most of job stressors were significantly correlated with job stress symptoms but their correlation coefficients were low. Among job stressors, quantitative work overload was found to be a major stressor. Workers in fashion industry appeared to evaluate their job performance relatively good. Also, it was found that behavioral and psychological symptoms were negatively correlated with job performance.

• The Korean Nurse
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• v.28 no.1
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• pp.77-88
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• 1989

The purpose of this study is to propose the baseline data for -developing the occupational stress measurement tool for Psychiatric nurses Working in the hospital. 135 staff nurses in psychiatric unit of 11. hospital were participated during the period from August 1 to August 20, 1988. Though the pretest and literature review a questionnaire was coristructed with 88 stressors which were experienced by the psychiatric nurses in the hospital. Subjects were given instruction to rate 1~6 likert type scale according to the level of stress experienced by each stressor described. Reliability of the tool was tested by Cronbach's Alpha and the reasult was ${\alpha}=0.94871$. Factor analysis was applied to organize 88 items together: As the result, 14 factors were obtained. The factors were; 1) Administration problem 2) Work overload 3) Role conflict as a profession 4) Lack of professional knowledge and skill 5) Conflict with nurses 6) Conflict with other health teams 7) Conflict in nurse-clint relationship 8) Conflict with supervisor 9) Conflict with suborinate 10) Low reward 11) Scheduling probrem 12) Inappropriate physical environment 13) Staff inadequate 14) Inadequate of equipment.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.2
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• pp.113-118
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• 2020

Hepatic stellate cells (HSCs) play essential roles in normal and pathophysiological function in liver. In steady state, HSCs contribute to retinoid storage, immune tolerance, and extracellular matrix (ECM) homeostasis. Upon liver injury, they become activated and lead to morphological and functional changes. Studies have demonstrated that activation of HSCs by various stimuli such as toxins, microbial infection, or metabolic overload can promote the fibrotic changes in liver by production of ECM. Herein, we provide current knowledge about the basic characteristics of HSCs and the mechanism by which they are activated.

• Journal of the Korean Home Economics Association
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• v.35 no.2
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• pp.201-216
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• 1997

The purpose of this study was to empirically verify the influence of socio-demograghic and psychological variables and the way of housework management on the satisfaction of housework management and to provide the information of enhancing the quality of life. In conclusion, the employed wives had tried to select and perform the way of household work management reducing the overload by multiple role performance. And then, it was influenced by housewives' individual resources and family resources. In order to accomplish the higher level of satisfaction of household work management, they must be selected and performed the effective ways of household work management that they are able to use.

• Journal of applied mathematics & informatics
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• v.12 no.1_2
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• pp.395-408
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• 2003

Common Channel Signaling(CCS) networks need special controls to avoid overload of signaling networks and degradation of call process-ing rate, since they play an important role of controlling communication transfer networks. Congestion control and flow control mechanisms are well described in ITU-T recommendation on Signaling System No.7(SS7). For the practical provisions, however, we need an analysis on the relation among service objects, system requirements and implementation of congestion control algorithms. SS7 provides several options for controlling link congestion in CCS networks. In this paper we give a general queueing model of congestion control algorithm which covers both the international and national options. From the queuing model, we obtain the performance parameters such as throughput, message loss rate and mean delay for the international option. To show the performance of the algorithm, some numerical results are also given.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.3
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• pp.183-196
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• 2024

Ferroptosis is a novel mechanism of programmed cell death, characterized by intracellular iron overload, intensified lipid peroxidation, and abnormal accumulation of reactive oxygen species, which ultimately resulting in cell membrane impairment and demise. Research has revealed that cancer cells exhibit a greater demand for iron compared to normal cells, indicating a potential susceptibility of cancer cells to ferroptosis. Stomach and colorectal cancers are common gastrointestinal malignancies, and their elevated occurrence and mortality rates render them a global health concern. Despite significant advancements in medical treatments, certain unfavorable consequences and drug resistance persist. Consequently, directing attention towards the phenomenon of ferroptosis in gastric and colorectal cancers holds promise for enhancing therapeutic efficacy. This review aims to elucidate the intricate cellular metabolism associated with ferroptosis, encompassing lipid and amino acid metabolism, as well as iron metabolic processes. Furthermore, the significance of ferroptosis in the context of gastric and colorectal cancer is thoroughly examined and discussed.