• BMB Reports
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• v.57 no.2
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• pp.98-103
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• 2024

The mammalian sirtuin family (SIRT1-SIRT7) has shown diverse biological roles in the regulation and maintenance of genome stability under genotoxic stress. SIRT7, one of the least studied sirtuin, has been demonstrated to be a key factor for DNA damage response (DDR). However, conflicting results have proposed that Sirt7 is an oncogenic factor to promote transformation in cancer cells. To address this inconsistency, we investigated properties of SIRT7 in hepatocellular carcinoma (HCC) regulation under DNA damage and found that loss of hepatic Sirt7 accelerated HCC progression. Specifically, the number, size, and volume of hepatic tumor colonies in diethylnitrosamine (DEN) injected Sirt7-deficient liver were markedly enhanced. Further, levels of HCC progression markers and pro-inflammatory cytokines were significantly elevated in the absence of hepatic Sirt7, unlike those in the control. In chromatin, SIRT7 was stabilized and colocalized to damage site by inhibiting the induction of γH2AX under DNA damage. Together, our findings suggest that SIRT7 is a crucial factor for DNA damage repair and that hepatic loss-of-Sirt7 can promote genomic instability and accelerate HCC development, unlike early studies describing that Sirt7 is an oncogenic factor.

• Journal of Ecology and Environment
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• v.47 no.4
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• pp.168-176
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• 2023

Background: Many insectivorous bats have flexible diets, and the difference in prey item consumption among species is one of the key mechanisms that allows for the avoidance of interspecies competition and promotes coexistence within a microhabitat. In Korea, of the 24 bat species that are known to be distributed, eight insectivorous bats use forest areas as both roosting and foraging sites. Here, we aimed to understand the resource partitioning and coexistence strategies between two bat species, Myotis ikonnikovi and Plecotus ognevi, cohabiting the Mt. Jumbong forests, by comparing the differences in dietary consumption based on habitat utilization. Results: Upon examining their dietary composition using the DNA meta-barcoding approach, we identified 403 prey items (amplicon sequence variants). A greater prey diversity including Lepidoptera, Diptera, Coleoptera, and Ephemeroptera, was detected from M. ikonnikovi, whereas most prey items identified from P. ognevi belonged to Lepidoptera. The diversity index of prey items was higher for M. ikonnikovi (H': 5.67, D: 0.995) than that for P. ognevi (H': 4.31, D: 0.985). Pianka's index value was 0.207, indicating little overlap in the dietary composition of these bat species. Our results suggest that M. ikonnikovi has a wider diet composition than P. ognevi. Conclusions: Based on the dietary analysis results, our results suggests the possibility of differences in foraging site preferences or microhabitat utilization between two bat species cohabiting the Mt. Jumbong. In addition, these differences may represent one of the important mechanism in reducing interspecific competition and enabling coexistence between the two bat species. We expected that our results will be valuable for understanding resource partitioning and the coexistence of bats inhabiting the Korean forests.

• New & Renewable Energy
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• v.20 no.2
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• pp.44-54
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• 2024

The objective of this study was to contribute to domestic offshore wind farms by reasonably predicting the expected completion time and installed power generation capacity of offshore wind projects in South Korea. Offshore wind power is drastically regarded as a core tool for clean energy transition and industrial decarbonization in the fight against the climate crisis globally. Especially in South Korea offshore wind power is the main tool in partaking in RE100 and K-RE100, and the Korean government aims to install 14.9 GW of offshore wind farms by 2030. However, this seems to have been significantly delayed due to the complex process of obtaining permits for offshore wind power in Korea. Thus, a reasonable prediction of power generation and a timeline for the final construction are imperative. To establish the delay time for permit licenses, classified location factors were included into site analysis. These factors comprised reviews of transmission and military operability, environmental impact assessment, maritime traffic safety examination, wind resource assessment and an analysis of current offshore wind projects. According to the analysis, the majority of offshore wind projects currently being developed in Korea are predicted to be delayed by 3-5 years as they are among the criteria included in key discussion points for obtaining permits. The cumulative installed power capacity and annual power generation after construction are expected to be 37 GW and 97 TWh respectively.

• Journal of the Korea Institute of Building Construction
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• v.24 no.1
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• pp.121-131
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• 2024

This research explores the potential of leveraging unstructured data from construction supervision documents, which contain detailed inspection insights from independent third-party monitors of building construction processes. With the evolution of analytical methodologies, such unstructured data has been recognized as a valuable source of information, offering diverse insights. The study introduces a framework designed to assess cost performance by applying advanced analytical methods to the unstructured data found in final construction supervision reports. Specifically, key phrases were identified using text mining and social network analysis techniques, and these phrases were then analyzed through binomial logistic regression to assess cost performance. The study found that predictions of cost performance based on unstructured data from supervision documents achieved an accuracy rate of approximately 73%. The findings of this research are anticipated to serve as a foundational resource for analyzing various forms of unstructured data generated within the construction sector in future projects.

• Korean Journal of Radiology
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• v.25 no.4
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• pp.331-342
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• 2024

The Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT) is an instructional initiative of the ASCI School designed to enhance educational standards. In 2021, the ASCI-PT was convened with the goal of formulating a consensus statement on the assessment of coronary stenosis and coronary plaque using coronary CT angiography (CCTA). Nineteen experts from four countries conducted thorough reviews of current guidelines and deliberated on eight key issues to refine the process and improve the clarity of reporting CCTA findings. The experts engaged in both online and on-site sessions to establish a unified agreement. This document presents a summary of the ASCI-PT 2021 deliberations and offers a comprehensive consensus statement on the evaluation of coronary stenosis and coronary plaque in CCTA.

• Geomechanics and Engineering
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• v.37 no.6
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• pp.577-590
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• 2024

With increasing demand for nuclear power generation, nuclear structures are being planned and constructed worldwide. A grave safety concern is that these structures are sensitive to large-magnitude shaking, e.g., during earthquakes. Seismic response analysis, which requires P- and S-wave velocities, is a key element in nuclear structure design. Accordingly, it is important to determine the P- and S-wave velocities in the Gyeongju and Pohang regions of South Korea, which are home to nuclear power plants and have a history of seismic activity. P- and S-wave velocities can be obtained indirectly through a correlation with physical properties (e.g., N values, Young's modulus, and uniaxial compressive strength), and researchers worldwide have proposed regression equations. However, the Gyeongju and Pohang regions of Korea have not been considered in previous studies. Therefore, a database was constructed for these regions. The database includes physical properties such as N values and P- and S-wave velocities of the soil layer, as well as the uniaxial compressive strength, Young's modulus, and P- and S-wave velocities of the bedrock layer. Using the constructed database, the geological characteristics and distribution of physical properties of the study region were analyzed. Furthermore, models for predicting P- and S-wave velocities were developed for soil and bedrock layers in the Gyeongju and Pohang regions. In particular, the model for predicting the S-wave velocity for the soil layers was compared with models from previous studies, and the results indicated its effectiveness in predicting the S-wave velocity for the soil layers in the Gyeongju and Pohang regions using the N values. The proposed models for predicting P- and S-wave velocities will contribute to predicting the damage caused by earthquakes.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.533-538
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• 2024

The risk assessment under the Occupational Safety and Health Act was implemented in 2013, but since it is not mandatory, companies are operating it as a formality. Although legal obligations have been strengthened, such as the recent comprehensive revision of the Occupational Safety and Health Act and the enforcement of the Act on Punishment for Serious Accidents, the death rate has remained stagnant. Even if a risk assessment plan is properly established in order for employers to prevent industrial accidents through necessary measures, it is necessary to involve relevant workers so that they can understand and implement the contents of the risk assessment. In this regard, this study proposed applying efficient worker participation measures through on-site surveys to activate the participation of vulnerable workers in risk assessments. Key words : risk assessment, accident prevention, vulnerable class, worker participation

• Journal of Veterinary Clinics
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• v.41 no.4
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• pp.215-222
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• 2024

An adult female dog was presented for evaluation of rapid growth of mammary gland masses. Complete blood count, serum biochemistry, and diagnostic imaging results were unremarkable. Fine needle aspirates of the mammary masses indicated mammary carcinoma characterized by large globoid cells with finely granular eosinophilic globules or Melamed-Wolinska-like bodies. A regional mastectomy was performed on the masses. Subsequent histopathologic examination of the surgically resected masses resulted in a diagnosis of mammary comedocarcinoma with nodal metastasis and distinct perivascular immune infiltrates, which were subject to immunohistochemical and flow cytometric immunophenotyping. Immunohistochemical examination confirmed the infiltration of CD3⁺ T and PAX5⁺ B lymphocytes. Flow cytometric analysis demonstrated tumor-infiltrating CD4⁺CD25⁺FOXP3⁺ regulatory T, CD8⁺ T, CD11b⁺ myeloid, and CD21⁺ B cells. Of note, paired flow cytometric analysis of peripheral blood and tumor tissues showed a preferential tumor infiltration of regulatory T and B cells. Approximately two months after the mastectomy, the tumor reoccurred at the surgery site. The dog died due to deteriorating conditions. We report a rare case of canine mammary comedocarcinoma, providing clinical, clinicopathologic, histologic, and immunophenotypic characteristics. Our case is valuable in providing a rationale for basic research that maps the immune landscape of mammary comedocarcinoma to identify key immune subsets for cancer progression.

• Journal of Oral Medicine and Pain
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• v.49 no.3
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• pp.49-56
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• 2024

Purpose: The aims were to investigate potential differences in clinical assessments among acute pain-related temporomandibular disorder (TMD) with different concordance value (CV) between number of self-reported painful site (NSP) and number of painful sites on palpation (NPP), and if it makes sense to treat them differently. Methods: A total of 61 patients were divided into three groups according to CV: 10 patients (concordance poor [CP]), 19 patients (concordance moderate [CM]), and 32 patients (concordance high [CH]). Clinical assessments were conducted using a standardized method in diagnostic criteria for temporomandibular disorders (DC/TMD). We compared collected information including sex, diagnosis, numerical rating scale (NRS), NPP, NSP, sleep duration, DC/TMD Axis II questionnaire, and perceived stress scale among three groups. Results: Among the clinical assessment, NRS, sleep duration, NPP, NSP, total scores of Oral Behaviors Checklist, Patient Health Questionnaire (PHQ)-15, PHQ-9 showed significant differences among 3 groups. NRS, NPP, NSP, PHQ-15, and PHQ-9 were higher in the CP group than in the CM and CH groups. Sleep duration was positively and NPP, NRS were negatively correlated with CV. Conclusions: While previous studies suggested differences between chronic and acute TMD in DC/TMD items, our findings propose the CV might be a key factor that could predict the severity and susceptibility of acute-TMD patients. However, Additional studies are required to determine whether their long-term prognosis was similar to that of chronic pain patients and what the response to treatment was among the three groups.

• Asia pacific journal of information systems
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• v.18 no.2
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• pp.41-72
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• 2008

The purpose of this study is the investigation of the effects of user participation, network effect, social influence, and usefulness on stickiness and continued use on Internet communities. In this research, stickiness refers to repeat visit and visit duration to an Internet community. Continued use means the willingness to continue to use an Internet community in the future. Internet community-based companies can earn money through selling the digital contents such as game, music, and avatar, advertizing on internet site, or offering an affiliate marketing. For such money making, stickiness and continued use of Internet users is much more important than the number of Internet users. We tried to answer following three questions. Fist, what is the effects of user participation on stickiness and continued use on Internet communities? Second, by what is user participation formed? Third, are network effect, social influence, and usefulness that was significant at prior research about technology acceptance model(TAM) still significant on internet communities? In this study, user participation, network effect, social influence, and usefulness are independent variables, stickiness is mediating variable, and continued use is dependent variable. Among independent variables, we are focused on user participation. User participation means that Internet user participates in the development of Internet community site (called mini-hompy or blog in Korea). User participation was studied from 1970 to 1997 at the research area of information system. But since 1997 when Internet started to spread to the public, user participation has hardly been studied. Given the importance of user participation at the success of Internet-based companies, it is very meaningful to study the research topic of user participation. To test the proposed model, we used a data set generated from the survey. The survey instrument was designed on the basis of a comprehensive literature review and interviews of experts, and was refined through several rounds of pretests, revisions, and pilot tests. The respondents of survey were the undergraduates and the graduate students who mainly used Internet communities. Data analysis was conducted using 217 respondents(response rate, 97.7 percent). We used structural equation modeling(SEM) implemented in partial least square(PLS). We chose PLS for two reason. First, our model has formative constructs. PLS uses components-based algorithm and can estimated formative constructs. Second, PLS is more appropriate when the research model is in an early stage of development. A review of the literature suggests that empirical tests of user participation is still sparse. The test of model was executed in the order of three research questions. First user participation had the direct effects on stickiness(${\beta}$=0.150, p<0.01) and continued use (${\beta}$=0.119, p<0.05). And user participation, as a partial mediation model, had a indirect effect on continued use mediated through stickiness (${\beta}$=0.007, p<0.05). Second, optional participation and prosuming participation significantly formed user participation. Optional participation, with a path magnitude as high as 0.986 (p<0.001), is a key determinant for the strength of user participation. Third, Network effect (${\beta}$=0.236, p<0.001). social influence (${\beta}$=0.135, p<0.05), and usefulness (${\beta}$=0.343, p<0.001) had directly significant impacts on stickiness. But network effect and social influence, as a full mediation model, had both indirectly significant impacts on continued use mediated through stickiness (${\beta}$=0.11, p<0.001, and ${\beta}$=0.063, p<0.05, respectively). Compared with this result, usefulness, as a partial mediation model, had a direct impact on continued use and a indirect impact on continued use mediated through stickiness. This study has three contributions. First this is the first empirical study showing that user participation is the significant driver of continued use. The researchers of information system have hardly studies user participation since late 1990s. And the researchers of marketing have studied a few lately. Second, this study enhanced the understanding of user participation. Up to recently, user participation has been studied from the bipolar viewpoint of participation v.s non-participation. Also, even the study on participation has been studied from the point of limited optional participation. But, this study proved the existence of prosuming participation to design and produce products or services, besides optional participation. And this study empirically proved that optional participation and prosuming participation were the key determinant for user participation. Third, our study compliments traditional studies of TAM. According prior literature about of TAM, the constructs of network effect, social influence, and usefulness had effects on the technology adoption. This study proved that these constructs still are significant on Internet communities.