• Journal of Ginseng Research
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• v.47 no.6
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• pp.755-765
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• 2023

Background: Caveolin-1, the scaffolding protein of cholesterol-rich invaginations, plays an important role in store-operated Ca²⁺ influx and its phosphorylation at Tyr14 (p-caveolin-1) is vital to mobilize protection against myocardial ischemia (MI) injury. SOCE, comprising STIM1, ORAI1 and TRPC1, contributes to intracellular Ca²⁺ ([Ca²⁺]_i) accumulation in cardiomyocytes. The purified extract of steamed Panax ginseng (EPG) attenuated [Ca²⁺]_i overload against MI injury. Thus, the aim of this study was to investigate the possibility of EPG affecting p-caveolin-1 to further mediate SOCE/[Ca²⁺]_i against MI injury in neonatal rat cardiomyocytes and a rat model. Methods: PP2, an inhibitor of p-caveolin-1, was used. Cell viability, [Ca²⁺]_i concentration were analyzed in cardiomyocytes. In rats, myocardial infarct size, pathological damages, apoptosis and cardiac fibrosis were evaluated, p-caveolin-1 and STIM1 were detected by immunofluorescence, and the levels of caveolin-1, STIM1, ORAI1 and TRPC1 were determined by RT-PCR and Western blot. And, release of LDH, cTnI and BNP was measured. Results: EPG, ginsenosides accounting for 57.96%, suppressed release of LDH, cTnI and BNP, and protected cardiomyocytes by inhibiting Ca²⁺ influx. And, EPG significantly relieved myocardial infarct size, cardiac apoptosis, fibrosis, and ultrastructure abnormality. Moreover, EPG negatively regulated SOCE via increasing p-caveolin-1 protein, decreasing ORAI1 mRNA and protein levels of ORAI1, TRPC1 and STIM1. More importantly, inhibition of the p-caveolin-1 significantly suppressed all of the above cardioprotection of EPG. Conclusions: Caveolin-1 phosphorylation is involved in the protective effects of EPG against MI injury via increasing p-caveolin-1 to negatively regulate SOCE/[Ca²⁺]_i.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.3
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• pp.215-227
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• 2022

In the digital transformation paradigm, IT employee work as a key human resource to accept new technologies and to lead their organization to be settled them efficiently. However, due to relatively short term of their job life and high turnover rate, the companies and the organizations are still experiencing problem the lack of IT manpower or turnover. In this study, it attempted to analyze the relationship between IT employee's technostress factors such as techno-overload, techno-complexity, techno-uncertainty, techno-invasion, and techno-insecurity and job burnout through stress coping. To reveal the structural relationship between main variables, the survey was conducted on 318 IT employees. An EFA, CFA, and reliability analysis were performed to confirm reliability and validity, and the structural equation model was conducted to testify research hypotheses. The main results are as follows. First, it was found that techno-uncertainty and techno-insecurity had the significant positive effect on problem focused coping(PFC). And, techno-complexity, techno-uncertainty, and techno-insecurity were found to have a significant positive effect on emotion focused coping(EFC). Second, in the relationship between stress coping and job burnout, it was found that EFC had a significant positive effect on burnout. Third, in the relationship between technostress and burnout, techno-uncertainty and techno-invasion were found to have a significant positive effect on burnout. In addition, it was found that the mediator effect of stress coping between techno-overload and techno-complexity through EFC. Therefore, these outputs are expected to suggest how to motivate IT employees who work as key role in efficient management on IT assets and strengthen competitiveness in digital transformation paradigm.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.114-122
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• 2014

The purpose of this study was to analyze the effect of mediating variables on the relationship between job stress and stress response. A survey was conducted to 243 clinical dental hygienists from January 15, 2013 to March 20, 2013 and the data were analyzed using t-test, one-way ANOVA, Pearson's correlation analysis, and hierarchical multiple regression analysis. The subjects who worked in poor working environment, had high level of role conflict and overload and aggressive nature showed high stress responsivity (p<0.01). The variable that showed mediation effect on the relationship between job stress and physical discomfort, depression was shown to be personality type (p<0.05). Also, the variable that showed mediation effect on the relationship between job stress and turnover intention was social support (p<0.05). According to the results, personality type and social support were shown to be important parameters when it came to the relationship between job stress and stress response. Therefore, in order to reduce negative outcomes caused by stress, it is suggested to provide an educational opportunity on self-control management while increasing social support from the organizational and structural level. Especially, it is asked to expand the system that provides encouragement and recognition to feel the sense of achievement in the course of their duty execution.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.1
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• pp.129-150
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• 1993

Since the restoration or masticatory function is the most important aim of implants, it should be substituted for the role of natural teeth and deliver the stress to the bone under the continous load during function. In natural teeth, stress distribution can be obtained through enamel, dentin and cementum and the elasticity of the periodontal ligament play a role of buffering action. In contrast, implant prosthesis has a very unique characteristics that it delvers the load directly to bone through the implant and superstructure. This fact arise the needs to evaluate the stress distribution of the implant in the mechnical aspects, which has a similar role of natural teeth but different pathway of stress. With 3 kinds of implant in prevalent use, 2 types of experimental PEA implant models were made, axisymmetric and 2-dimensional type. In axisymmetric model, the stiffness of the part including the prosthesis and implant which extrude out of bony surface could be calculated with displacement of the superstructure un er 100N vertical load and then damping effects could be determined through this stiffness. In axisymmetric FEA model, load to the bone could be deduced by evaluation the stress distribution of the designed surface under the 100N vertical force and in 2-dimensional model, 100N eccentric vertical load and 20N horizontal loda. The result are as follows. 1. In every implant, stress to the bone tends to be concenturated on the cortical bone. 2. Though the stress of the cancellous bone is larger at the apex of implants, it is less compared with cortical bone. 3. Under 20N horizontal load, stress of the left and right sides of implant shows a symmetrical pattern. But under 100N eccentric vertical load, loaded side shows much larger stress value. 4. In the 1mm interface, stress distribution among implants tend to have a similar pattern. But under 20N horizontal load apposite side of being loaded shows less stress in IMZ. 5. In the case of screw type implant, stress tends to vary along with screw shape. 6. According to the result determined with microstrain, cancellous bone id generally under the condition of overload, while cortical bone is usually within the limitation of physiologic load. 7. In the Branemark implant, maximum stress to the cortical bone is larger than any other implant except for the condition of 20N horizontal force and 0.05mm interface. 8. Damping effects of implants is maximum in IMZ.

• Korea journal of population studies
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• v.33 no.2
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• pp.137-163
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• 2010

This study examines how individual, familial, and social factors are associated with persistent very low fertility in Busan Metropolitan City and contemplates family-friendly environments and social strategies for fertility increase. Fertility decline in Busan Metropolitan City recorded the lowest birth rate nationwide recent years among metropolitan cities and provinces in Korea. Birthrates are low partly because of multiple factors such as high age at childbearing and at marriage, decline in marriage, high divorce rate, the phenomena of marriage avoidance among unmarried women, traditional gender role attitude of men, low domestic work participation of husbands among dual career couples, low marital satisfaction and family life satisfaction, abortion, and more broader attiributes such as family policy, availability of childcare, education expenses, and family-friendlyness of a society. In addition, women of dual career couples in Busan strained from domestic work overload under traditional norms of gender role, and marital satisfaction recorded below average nationwide along with espeacially low marital satisfaction of wives compared to that of husbands. Major aspects of implications and considerations for higher birth rate and family friendly policy in Busan are discussed.

• Journal of Venture Innovation
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• v.7 no.3
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• pp.25-43
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• 2024

The rapid advancement of the 4th Industrial Revolution and the ongoing effects of COVID-19 significantly accelerated the adoption of smart work practices, especially in the financial sector. This study aimed to empirically investigate the impact of smart work on job satisfaction among employees in this industry. Specifically, the study examined the effects of time flexibility and workplace flexibility (as quantitative elements of smart work) and work autonomy (as a qualitative element) on job satisfaction. Additionally, the study explored the impact of technostress factors, including techno-overload, techno-invasion, and techno-complexity. Using data from 250 valid survey responses collected from financial sector employees, the study employed structural equation modeling (SEM) with AMOS to analyze the relationships. The findings revealed that time flexibility and work autonomy positively influenced job satisfaction, with work autonomy being the most significant predictor. Conversely, techno-overload and techno-invasion negatively affected job satisfaction. However, workplace flexibility and techno-complexity did not show a significant relationship with job satisfaction, possibly due to the already established norms in the financial sector, where remote work and high-level technology usage were standard practices. A critical aspect of the study was the examination of work-life balance as a mediating factor. The analysis confirmed that work-life balance mediated the relationship between work autonomy, techno-overload, techno-invasion, and job satisfaction. This suggested that maintaining a balance between work and personal life was crucial for enhancing job satisfaction in smart work environments, particularly in the financial sector. Effective management of technostress was essential to preserving this balance and improving overall employee satisfaction. These findings contributed to the academic understanding of how smart work practices and technostress impacted job satisfaction. They offered practical insights for financial sector organizations seeking to optimize smart work environments by emphasizing the importance of work-life balance and carefully managing technostress factors.

• Journal of Korean Academy of Nursing
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• v.41 no.4
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• pp.568-579
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• 2011

Purpose: The purpose of the study was to understand and describe the hospital workers' experience related to the hospital evaluation program implemented in Korea between 2004 and 2009. Methods: During 2010, data were collected using focus group interviews. Four focus group interviews were held with a total of 28 hospital workers participating. All interviews were recorded and transcribed as they were spoken, and data were analyzed using qualitative content analysis. Results: Nine themes emerged from the analysis: 1) Positive change in the necessity of the evaluation; 2) Improvement in the hospital system, facilities, and human resources; 3) Unity through cooperation among departments; 4) Nursing work overload; 5) Lack of physicians' awareness and responsibilities; 6) Unfair and unrealistic evaluation items; 7) Lack of credibility of the outcome; 8) Shifting responsibility for negative outcomes to the workers; 9) Lack of pragmatic utility. Conclusion: The results of the study demonstrate that the hospital evaluation program played a key role in improving some work environments and communication among departments. At the same time, they show various negative themes resulting from the context of very authoritarian hospital systems and a connection-oriented society in Korea.

• The Journal of Korean Physical Therapy
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• v.15 no.3
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• pp.16-44
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• 2003

Skeletal muscle regeneration is a vital process for various muscle myopathies and muscular adaptation to physiological overload. Angiogenesis is the key event in the process of muscle regeneration, and vascular endothelial growth factor(VEGF) plays an important role in it. The purpose of this study was to evaluate the effect of GaAlAs(830nm) laser and immunoreactivity of VEGF on angiogenesis after muscle contusion injury. Muscle contusion injury was induced in the triceps surae muscle by dropping a metal bead(31.4g). GaAlAs laser irradiation(power 20 mW, frequency 2000 Hz, treatment time 15 min) was applied directly to the skin of injured muscle daily for seven days. The experimental group I was irradiated immediately by laser after injury, whereas the experimental group II was irradiated after 1 day of injury. The control group was non-irradiated. The results of this study were as follows. 1. In morphological observation, there were no significant changes in experimental and control groups for 7 days. At 3 days, however, the splited muscle fibers were observed in experimental groups, and the muscle atrophy and granular tissue viewed at 7 days in control group. 2. The VEGF was expressed in muscle fiber that located in the interspace between gastrocnemius and soleus muscles. As the time coursed, the immunoreactivity of VEGF also seemed to be strong in the individual muscle fibers. 3. The experimental group I & II showed higher immunoreactivity of VEGF than control group(p<0.05). Then, the experimental group I showed higher than group II especially(p<0.05). These data suggest GaAlAs semiconduct diode laser irradiation(830nm) enhanced angiogenesis in the skeletal muscle induced contusion injury, and immediate laser irradiation after injury promoted the angiogenesis greatly than after 1 day of injury.

• Journal of KIISE
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• v.43 no.11
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• pp.1188-1200
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• 2016

Recommendation systems play a significant role in providing personalized information to users, with enhanced satisfaction and reduced information overload. Since the mid-1990s, many studies have been conducted on recommendation systems, but few have examined the recommendations of information from people in the online social networking environment. In this paper, we present a hybrid recommendation method that combines both the traditional system of content-based techniques to improve specialization, and the recently developed system of social network-based techniques to best overcome a few limitations of the traditional techniques, such as the cold-start problem. By suggesting a state-of-the-art method, this research will help users in online social networks view more personalized information with less effort than before.

• Reproductive and Developmental Biology
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• v.39 no.4
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• pp.117-125
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• 2015

Iron is required for cell viability but is toxic in excess. While the iron-mediated malfunction of testicular cells is well appreciated, the underlying mechanism(s) of this effect and its relationship with fertility are poorly understood. Ferritin is a ubiquitous intracellular protein that controls iron storage, ferroxidase activity, immune response, and stress response in cells. Ferritin light chain protein (FTL) is the light subunit of the Ferritin. Previously, we had identified the FTL in bovine spermatozoa following capacitation. In present study, to investigate the role of Ferritin in sperm function, mice spermatozoa were incubated with multiple doses (1, 10 and $100{\mu}M$) of sodium nitroprusside (SNP), an iron donor. SNP was increased Ferritin levels in a dose-dependent manner. The Ferritin was detected on the acrosome in spermatozoa by immunocytochemistry. Short-term exposure of spermatozoa to SNP increased tyrosine phosphorylation and the acrosome reaction (AR). Finally, SNP affected a significant decrease in the rate of fertilization as well as blastocyst formation during early embryonic development. On the basis of these results, we propose that the effects of Ferritin on the AR may reduce overall sperm function leads to poor fertility in males and compromised embryonic development.