• BMB Reports
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• v.57 no.6
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• pp.281-286
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• 2024

Adult hippocampal neurogenesis plays a pivotal role in maintaining cognitive brain function. However, this process diminishes with age, particularly in patients with neurodegenerative disorders. While small, non-coding microRNAs (miRNAs) are crucial for hippocampal neural stem (HCN) cell maintenance, their involvement in neurodegenerative disorders remains unclear. This study aimed to elucidate the mechanisms through which miRNAs regulate HCN cell death and their potential involvement in neurodegenerative disorders. We performed a comprehensive microarray-based analysis to investigate changes in miRNA expression in insulin-deprived HCN cells as an in vitro model for cognitive impairment. miR-150-3p, miR-323-5p, and miR-370-3p, which increased significantly over time following insulin withdrawal, induced pronounced mitochondrial fission and dysfunction, ultimately leading to HCN cell death. These miRNAs collectively targeted the mitochondrial fusion protein OPA1, with miR-150-3p also targeting MFN2. Data-driven analyses of the hippocampi and brains of human subjects revealed significant reductions in OPA1 and MFN2 in patients with Alzheimer's disease (AD). Our results indicate that miR-150-3p, miR-323-5p, and miR-370-3p contribute to deficits in hippocampal neurogenesis by modulating mitochondrial dynamics. Our findings provide novel insight into the intricate connections between miRNA and mitochondrial dynamics, shedding light on their potential involvement in conditions characterized by deficits in hippocampal neurogenesis, such as AD.

• Steel and Composite Structures
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• v.50 no.3
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• pp.281-298
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• 2024

Stainless steel bolts (SSB) are increasingly utilized in bolted steel connections due to their good mechanical performance and excellent corrosion resistance. Fire accidents, which commonly occur in engineering scenarios, pose a significant threat to the safety of steel frames. The post-fire behavior of SSB has a significant influence on the structural integrity of steel frames, and neglecting the effect of temperature can lead to serious accidents in engineering. Therefore, it is important to evaluate the performance of SSB at elevated temperatures and their residual strength after a fire incident. To investigate the mechanical behavior of SSB after fire, 114 bolts with grades A4-70 and A4-80, manufactured from 316L austenitic stainless steel, were subjected to elevated temperatures ranging from 20℃ to 1200℃. Two different cooling methods commonly employed in engineering, namely cooling at ambient temperatures (air cooling) and cooling in water (water cooling), were used to cool the bolts. Tensile tests were performed to examine the influence of elevated temperatures and cooling methods on the mechanical behavior of SSB. The results indicate that the temperature does not significantly affect the Young's modulus and the ultimate strength of SSB. Up to 500℃, the yield strength increases with temperature, but this trend reverses when the temperature exceeds 500℃. In contrast, the ultimate strain shows the opposite trend. The strain hardening exponent is not significantly influenced by the temperature until it reaches 500℃. The cooling methods employed have an insignificant impact on the performance of SSB. When compared to high-strength bolts, 316L austenitic SSB demonstrate superior fire resistance. Design models for the post-fire mechanical behavior of 316L austenitic SSB, encompassing parameters such as the elasticity modulus, yield strength, ultimate strength, ultimate strain, and strain hardening exponent, are proposed, and a more precise stress-strain model is recommended to predict the mechanical behavior of 316L austenitic SSB after a fire incident.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.97-109
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• 2024

In the field of domestic tourism, tourism trend analysis of tourism consumers, both international tourists and domestic tourists, is essential not only for the Korean tourism market but also for local and governmental tourism policy makers. e will explore the keywords and sentiment analysis on social media to establish a marketing strategy plan and revitalize the domestic tourism industry through communication and information from tourism consumers. This study utilized TEXTOM 6.0 to analyze recent trends in Korean tourism. Data was collected from September 31, 2022, to August 31, 2023, using 'Korean tourism' and 'domestic tourism' as keywords, targeting blogs, cafes, and news provided by Naver, Daum, and Google. Through text mining, 100 key words and TF-IDF were extracted in order of frequency, and then CONCOR analysis and sentiment analysis were conducted. For Korean tourism keywords, words related to tourist destinations, travel companions and behaviors, tourism motivations and experiences, accommodation types, tourist information, and emotional connections ranked high. The results of the CONCOR analysis were categorized into five clusters related to tourist destinations, tourist information, tourist activities/experiences, tourism motivation/content, and inbound related. Finally, the sentiment analysis showed a high level of positive documents and vocabulary. This study analyzes the rapidly changing trends of Korean tourism through text mining on Korean tourism and is expected to provide meaningful data to promote domestic tourism not only for Koreans but also for foreigners visiting Korea.

• Journal of Music and Human Behavior
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• v.21 no.2
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• pp.51-75
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• 2024

This case study aimed to develop a therapeutic rap protocol based on narrative components for improving discourse skills of adolescents with mild intellectual disability (ID) and to explore its applicability. The protocol matched narrative elements (background, initiating event, internal response, attempts, and reaction) with rap components (verse, hook, and interjections), guiding participants to narrate their experiences in a connected discourse form. The protocol was also structured to gradually increase in difficulty, considering the developmental levels of adolescents with ID and it included steps for understanding discourse structures, applying narrative elements to content creation, and expanding narratives. Post-intervention analysis of the stories and rap lyrics created by participants to express their real-life experiences showed that participants increased the length of their stories and rap compositions, with notable improvements in rhythmicity and the inclusion of narrative elements. These findings suggest that, instead of constructing rap from random utterances, providing a structured framework reflecting discourse structure enhanced participants' understanding of event context and logical connections. Furthermore, the various elements and rhythmic features of rap can strengthen motivation and organization in discourse. This study highlights the therapeutic potential of rap in addressing the unique developmental needs of adolescents with mild ID, thereby diversifying and systematizing music therapy interventions for this population.

• The Journal of the Convergence on Culture Technology
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• v.10 no.4
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• pp.509-516
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• 2024

We rethink human existence as a assemblage through intersectionality by comparing autopoiesis and sympoiesis systems with reference to science fiction protagonists such as Ghost in the Shell, Neuralink, Camille, a genetic hybrid, and San Ti against the background of neo-materialism. Our findings reveal that, first, radical sympoiesis is characterized by the dissolution of individuals and boundaries, and attempt to explain existence solely through heterogeneous linkage and fusion; second, by ignoring the capacity for autonomous thinking at the individual level, they are unable to fully recognize the destructive nature of hybrid co-production or to develop practical responses to it. Third, we suggest that if the very survival of humanity is threatened by heterogeneous linkage, we should pay more attention to our identity as autonomous members of a autopoietic system rather than to heterogeneous sympoietic networks and we should also pay attention to the role of individual units in stabilizing self-regulation. Through this study, we aimed to contribute to overcoming the limitations of neo-materialism by arguing that it is likely to fail to provide an adequate practical vision if it is limited to describing the hybrid connections that recur through the intersection of beings, and by urging us to define the identity of the human species from a new perspective by utilizing various SF stories that trigger the imagination of destructive interactions between beings, and to explore the autopoiesis in terms of symbiotic interactions based on a certain level of boundary and self-regulation.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.4
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• pp.396-408
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• 2008

Statement of problem: Within the elastic limit of the screw, the greater the preload, the tighter and more secure the screw joint. However, additional tensile forces can incur plastic deformation of the abutment screw when functional loads are superimposed on preload stresses, and they can elicit the loosening or fracture of the abutment screw. Therefore, it is necessary to find the optimum preload that will maximize fatigue life and simultaneously offer a reasonable degree of protection against loosening. Another critical factor in addition to the applied torque which can affect the amount of preload is the joint connection type between implant and abutment. Purpose: The purpose of this study was to evaluate the influence of tightening torque on the implant-abutment screw joint stability. Material and methods: Respectively, three different amount of tightening torque (20, 30, and 40 Ncm) were applied to implant systems with three different joint connections, one external butt joint and two internal cones. The initial removal torque value and the postload (cyclic loading up to 100,000 cycles) removal torque value of the abutment screw were measured with digital torque gauge. Then rate of the initial and the postload removal torque loss were calculated for the comparison of the effect of tightening torques and joint connection types between implant and abutment on the joint stability. Results and conclusion: 1. Increase in tightening torque value resulted in significant increase in initial and postload removal torque value in all implant systems (P < .05). 2. Initial removal torque loss rates in SS II system were not significantly different when three different tightening torque values were applied (P > .05), however GS II and US II systems exhibited significantly lower loss rates with 40 Ncm torque value than with 20 Ncm (P < .05). 3. In all implant systems, postload removal torque loss rates were lowest when the torque value of 30 Ncm was applied (P < .05). 4. Postload removal torque loss rates tended to increase in order of SS II, GS II and US II system. 5. There was no correlation between initial removal torque value and postload removal torque loss rate (P > .05).

• Journal of the Korean earth science society
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• v.29 no.2
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• pp.189-203
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• 2008

Microcomputer Based Laboratory (MBL), by offering accurate and effective data collection and real-time graphs, enables students to reduce experiment time and, thereby, have deeper discussions concerning experimental results. This helps to emphasis the essential aspect of scientific inquiry; the process communication. Therefore, this study examined secondary school earth science MBL lessons with regards to the five basic aspects of scientific inquiry: "Asking", "Evidencing", "Explaining", "Evaluating" and "Communicating". It then investigated the level of argumentative communication between the students and teachers and also among the students themselves. For this study, three classroom activities were observed and videotaped, and teaching materials, textbooks and students' notes were collected. The transcribed data were analyzed from the perspective of scientific inquiry level and argument frames. The results showed that the scientific inquiry levels of the three classes were similar, except for the "Communicating" aspect, which appeared in only one episode. "Asking" was carried out by the teacher and then students were directed to collect certain data in the "Evidencing" stage. Furthermore, students were given possible ways to use evidence to formulate explanations and connections through the "Explaining" and "Evaluating" stages. In the argumentation analysis, most argumentative communication was identified as being associated with a given procedure, rather than with any scientific phenomena. In only one episode, did "Communicating" relate directly to any scientific phenomena. It can be concluded, that although MEL places emphasis on communication for authentic scientific inquiry, the environment required for such inquiry and argumentative communication can not be easily created in the classroom. Therefore, in order for authentic inquiry to take place in the MBL classroom, teachers should provide students with the opportunity to develop meaningful argumentation and scaffolding abilities.

• Journal of dental hygiene science
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• v.6 no.3
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• pp.147-152
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• 2006

The purpose of this study was to help decrease turnover and to make full use of dental hygienists and to help improve management by managers. After relevant literature and data were reviewed, a survey was conducted on dental hygienists, who worked at dental institutes in different areas, for about four months from September through December, 2004, to find out their turnover intention and job satisfaction level. When the collected data were analyzed, the following findings were given: 1. The collective average of the dental hygienists investigated in job satisfaction was $3.30{\pm}0.70$. By area, they expressed the best satisfaction at a clear role factors with a mean of $3.53{\pm}0.73$, and they were pleased with wages factors and promotion factors the least with an average of $3.14{\pm}0.70$ and $3.18{\pm}0.80$. 2. The collective average of the dental hygienists investigated in turnover intention was $3.23{\pm}0.77$. As for connections between general characteristics and turnover intention, By age, those who aged in 21 and 25 were most intended(p < 0.001). The unmarried dental hygienists were more intended than the married ones(p < 0.001). By type of hospital, those who worked at dental clinics were most intended(p< 0.01). By career, those who had worked at one to three years were intended the most(p < 0.001), and as to the length of service at current work places, those who had worked at their current work places for one to three years were intended the most(p < 0.001). By monthly mean pay, those whose pay ranged from 1.3 to 1.6 million won found their turnover most intended(p< 0.01). 3. Regarding correlation among turnover intention and job satisfaction were both inversed correlationship, and wages factor(r = -0.249, p < 0.01) and interrelationship factors(r = -0.218, p < 0.01) had a strong correlation to turnover intention, and clear role factors had a strong correlation to job contents factors by job satisfaction(r = 0.612, p < 0.01), and job satisfaction factors had a strong correlation to job contents factors(r = 0.759, p < 0.01).

• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.4
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• pp.281-301
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• 1993

It was revealed that the morphology and projection pattern of terminal arbors from single primary afferent are different among distinct fiber types, functional types and the different subdivision of trigeminal sensory nucleus complex(TSNC). But it was not identified the ultrastructural morphology and synaptic connections of terminal arbors from each primary afferent within TSNC. So we employed the intra-axonal horseradish peroxidase(HRP) injection technique to define the terminal arbors of primary afferent fiber from slowly adapting mechanoreceptors in the periodontal ligament of the cat, and examined 66 labeled terminal arbors within the rostrodorsomedial part(Vo.r) of the trigeminal nucleus oralis, electromicroscopically with 90nm serial sections. All the boutons labelled with HRP contained clear, spherical and uniform sized synaptic vesicles(diameter : $47.66{\pm}3.58nm$ ). Most of the labelled boutons were boutons en passant type and they were connected by unmyelinated axonal strand. In which neurofilament and microtubule was not developed but occasionally contained synaptic vesicle in contrast to the myelinated axon. The size of the labelled bouton was relatively small(long diameter : $1.46{\pm}0.24{\mu}m$, short diameter $0.85{\pm}0.26{\mu}m$, average diameter $1.15{\pm}0.24{\mu}m$) and the shape of which varied from dome to elongated shape, but scalloped glomerulus shape was not developed. Each primary ending in Vo.r made synapse with one or two neuronal propiles(average : $1.11{\pm}0.31$), of which, 89.4% of labelled boutons made synapse with only one neuronal pro pile, the remainder, 10.6% of labelled boutons, made synapse with two neuronal propile. So characteristically they made very simple synapse. Most of labelled boutons(80.03%) made asymmetrical synapse only with dendritic shaft or spine, and 6.1% of labelled boutons received symmetrical synapse from pleomorphic vesicle containing axonal ending(p-ending). So presynaptic inhibiton was relatively scarce. Synaptic triad, in which a p-ending is presynaptic both pre-and post-synaptic element of the axo-dendritic contact from the labelled primary ending was not observed.

• Journal of Korean Home Economics Education Association
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• v.27 no.1
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• pp.85-109
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• 2015

The purposes of this study were to analyze the duplicated contents of 'family life' unit of home economics and other subject textbooks for the middle school students. It focused on the 'family life' area in the home economics textbook compiled following the 2009 revised curriculum, and textbooks of other subjects compiled in the same period. To achieve the purpose of this study, "Home economics I II", "Ethics I II", "Social studies I II", "Science I II III", and "Physical education"were analyzed. The results were as follows. The contents in 'family life' area of "Home economics I II" were overlapped most in the textbook on Ethics, and then Science, Physical education, and social studies in order. In Ethics textbook the contents in family life area and those throughout the whole chapters of home economics textbook are overlapped most. The contents of home economics textbook are overlapped at the content of 'Juvenile's sexual development' of 'Human development process' in science and physical education, and at the content of 'Juvenile's emotional and social development' of 'Understanding of human development' in social studies. Seen from this study the 'family life' area of home economics is overlapped in science, physical education, and social studies, but, home economics has comprehensive contents with the goal of managing healthy individual and family life compared with other subjects, and it induces students' moral practices in their real life on the basis of scientific knowledge different from morality, social studies, and physical education. Hence, the instruction of 'family life' area might be done more effectively by focusing on home economics and integrating the connections of duplicated contents in Ethics, Science, Physical education, and Social studies.