• Geomechanics and Engineering
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• v.18 no.6
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• pp.627-638
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• 2019

Estimation of representative elementary volume (REV) of jointed rock masses is critical to predict the mechanical behavior of field-scale rock masses. The REV of jointed rock masses at site is strongly influenced by stress state. The paper proposed a method to systematically studied the influence of confining stress on the REV of jointed rock masses with various strengths (weak, medium and strong), which were sourced from the water inlet slope of Xiaowan Hydropower Station, China. A finite element method considering material heterogeneity was employed, a series of two-dimensional (2D) models was established based on the Monte-Carlo method and a lot of biaxial compressive tests were conducted. Numerical results showed that the REV of jointed rock masses presented a step-like reduction as the normalized confining stress increased. Confining stress weakened the size effect of jointed rock masses, indicating that the REV determined under uniaxial compression test can be reasonably taken as the REV of jointed rock masses under complexed in-situ stress environment.

• Biomolecules & Therapeutics
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• v.30 no.5
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• pp.391-398
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• 2022

Polyploidization is a process by which cells are induced to possess more than two sets of chromosomes. Although polyploidization is not frequent in mammals, it is closely associated with development and differentiation of specific tissues and organs. The liver is one of the mammalian organs that displays ploidy dynamics in physiological homeostasis during its development. The ratio of polyploid hepatocytes increases significantly in response to hepatic injury from aging, viral infection, iron overload, surgical resection, or metabolic overload, such as that from non-alcoholic fatty liver diseases (NAFLDs). One of the unique features of NAFLD is the marked heterogeneity of hepatocyte nuclear size, which is strongly associated with an adverse liver-related outcome, such as hepatocellular carcinoma, liver transplantation, and liver-related death. Thus, hepatic polyploidization has been suggested as a potential driver in the progression of NAFLDs that are involved in the control of the multiple pathogenicity of the diseases. However, the importance of polyploidy in diverse pathophysiological contexts remains elusive. Recently, several studies reported successful improvement of symptoms of NAFLDs by reducing pathological polyploidy or by controlling cell cycle progression in animal models, suggesting that better understanding the mechanisms of pathological hepatic polyploidy may provide insights into the treatment of hepatic disorders.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.3
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• pp.121-131
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• 2023

African breast cancer patients benefit less from classical pathology services owing to the complex molecular and clinicopathological nature of the disease, poor quality of laboratory supplies, and shortage of experts in the field. This review presents evidence and confirms the need for improving anatomic pathology services in Africa. Peer-reviewed international journal articles available in Medline, Scopus, PubMed, and Google scholars, describing the status of pathology services in Africa, were included. Besides the late presentation of patients, anatomic pathology laboratories are accountable for the escalated mortality of breast cancer patients in several parts of Africa. Conversely, molecular diversity and biological heterogeneity of breast cancers, which disprove the one-size-fits-all therapeutic approach, have been reported from different parts of the continent. Irrespective of the geographical background, the choice of therapeutic options and predicting disease outcome depends on the right identification of the molecular signature of the cancer type. In conclusion, we propose that upgrading and integrating anatomic pathology with molecular diagnostic pathology is essential in order to provide better diagnostic results that will profoundly impact curbing mortality from breast cancers.

• Asia-Pacific Journal of Business
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• v.15 no.3
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• pp.417-430
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• 2024

Purpose - This paper investigates the asymmetric capital structure adjustment toward target leverage. Our study consistently estimates heterogeneous speeds of adjustment in different regimes reflecting heterogeneity in firm characteristics. Design/methodology/approach - We collect balanced panel data on Korean listed firms over the period 2005 - 2023. In order to capture non-linearities in the speed of capital structure adjustments, this paper employs the dynamic panel threshold model that allows endogeneity in regressors and threshold variables. Findings - Using firm characteristics as proxies for adjustment costs of deviation from and adjustment to target leverage, we find asymmetric effects on the speed of capital structure adjustments. Firms of large size, with high profitability, with large cash flow and with large investment adjust capital structure faster than those with the opposite characteristics. On the other hand, firms with high growth opportunities and with high risk move slowly toward the target leverage. Research implications or Originality - This paper provides new evidence of cross-sectional asymmetries in capital structure adjustments, which calls for cautions in sample-splitting in an arbitrary manner.

• The Korean Journal of Health Service Management
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• v.9 no.3
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• pp.175-185
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• 2015

Objectives : This study was did a meta-analysis of emergency room visits decreased effectiveness of self management education interventions in asthma among adult patients with asthma. Methods : A search of the database PubMed resulted in identifying 8,619 studies done between January 1990 and November 2012. STATA version 10.0 was used to analyze the effect size, explore possible causes of heterogeneity, and determine publication bias with a funnel plot. Results : We included 7 cases on emergency room visits decreased effectiveness of self management and education. Asthmatic patients experienced fewer attacks (summary effect size, 0.75; 95% confidence interval [CI], 0.65-0.95). We found that emergency room visits decreased effectiveness of self management and education were associated with statistically significant effects. Conclusions : Based on these finding, self management and education on interventions are necessary to prevent asthmatic attacks in patients and to reduce the severity of the attacks, and self management and education programs are needed in Korea.

• Journal of Korean Academy of Nursing
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• v.46 no.4
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• pp.475-489
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• 2016

Purpose: This study was a systematic review and meta-analysis designed to investigate the effects of stimulation-oriented interventions for behavioral problems among people with dementia. Methods: Based on the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), a literature search was conducted using seven electronic databases, gray literature, and other sources. Methodological quality was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) for randomized controlled trials (RCTs). Data were analyzed using R with the 'meta' package and the Comprehensive Meta-Analysis (CMA 2.0) program. Results: Sixteen studies were included for meta-analysis to investigate the effect of stimulation-oriented interventions. The quality of individual studies was rated as '++' for eight studies and '+' for the rest. The effect sizes were analyzed according to three subgroups of interventions (light, music, and others); Hedges' g=0.04 (95% CI: -0.38~0.46), -0.23 (95% CI: -0.56~0.10), -0.34 (95% CI: -0.34~0.00), respectively. To explore the possible causes of heterogeneity ($I^2=62.8%$), meta-regression was conducted with covariates of sample size, number of sessions, and length of session (time). No moderating effects were found for sample size or number of sessions, but session time showed a significant effect (Z=1.96, 95% CI: 0.00~0.01). Finally, a funnel plot along with Egger's regression test was performed to check for publication bias, but no significant bias was detected. Conclusion: Based on these findings, stimulation-oriented interventions seem to have a small effect for behavioral problems among people with dementia. Further research is needed to identify optimum time of the interventions for behavioral problems among dementia pateints.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.1
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• pp.38-47
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• 1999

The mixed rural city is adjusting to change by urbanization. The recent landcover change in mixed rural city is an important factor that changes structure and function of regional ecosystem. Landscape ecology is an integrated ecology widely available for environmental science such as nature conservation and sustainable land-use planning. As the concern about environmental quality rises, many studies are trying to create and conservate for biotop. The creation of biotop is related to the plan and management of the effective landuse because the important factor to change the structure and function of ecological area in the country. This study was carried out to establish the foundation of the landuse plan to analyze the change of landuse and to plan the scheme in creating biotop and landuse. We used the approach of ecological landscape and using landscape indices with RS(Remote Sensing) and GIS(Geographic Information System) technology, spatio-temporal variations of areas and distribution of forest patches were examined in the Sunghwan in Chonan from 1985 to 1996. A result of this study showed that the area of forest and paddy decreased by urban sprawl. The size of patch in the forest and agriculture had been smaller and irregular form, heterogeneity of size of forest and agriculture patches within sub-basin was increased, pattern of forest and agriculture patches decreased the corridor and network from 1985 to 1996.

• Journal of Korea Technology Innovation Society
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• v.8 no.1
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• pp.135-153
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• 2005

With an explosive growth of internet and a change of consumer's demand, Post PC is emerging as a substitute for the existing desktop computer and laptop computer. Post PC is a new computer which is portable with wireless networking, cheaper than the existing PCs and specialized in the specific function that consumers want. Furthermore, the shape and the ability of Post PC are dependent on its specific function. The rudimentary Post PCs such as PDA, web-pad and smart-phone are already usable. And in the future, owing to the progress of technologies, the heterogeneity of relate companies and the low entry barrier, various Post PCs will be developed. In this paper, we analyze consumers' willingness-to-pay for Post PC with the attributes such as the portability, the speed of CPU, the data input method (using key board, or notepad etc), the size of monitor and price. To estimating consumers' willingness-to-pay for the attributes of Post PC, we apply a contingent ranking method, which makes the respondents rank hypothetical Post the portability, the speed of CPU, the data input method (using key board, or notepad etc),the size of monitor and price. To estimating consumers' willingness-to-pay for the attributes of Post PC, we apply a contingent ranking method, which makes the respondents rank hypothetical Post PC alternatives featuring various combinations of attributes, to a survey data collected in Korea. Using the estimated willingness-to-pay, we predict the shape and the ability of future's Post PC and draw policy implications for the national and company level R&D strategies.

• Journal of the Korea Convergence Society
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• v.9 no.6
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• pp.347-355
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• 2018

A convergence study was conducted to identify effect size, intervention characteristics, and tendency of laughter therapies on depression for Korean older adults. Of the 486 studies searched in 10 databases, 20 studies in the inclusion criteria were selected. The risk of bias was assessed by SIGN's tool, and the data were analyzed using CMA 3.0 software. Overall effect size of laughter therapy on depression of older adults was medium (standardized mean difference [SMD]=-0.57, 95% CI: -0.70~-0.44, p<.001), and heterogeneity was small ($I^2=18%$). Subgroup analysis showed that the effect sizes of institutionalized group, mixed group, 4-6 weeks of duration, and group intervention were higher than the compared groups. Findings of this convergent meta-analysis would be helpful for health professionals to provide more effective laugher therapy sessions. Further replicative studies in long-term care facilities and more randomized controlled trials of laughter therapy are needed.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7597-7602
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• 2014

Background: Amplification and overexpression of human epidermal growth factor receptor 2 (HER2/neu) oncogene has considerable prognostic value in breast and gastric cancers. This study aimed to evaluate the frequency, overexpression pattern, clinical significance, and concordance between the results for protein expression and gene amplification of HER-2/neu in gastric and gastro-esophageal junction carcinomas. Materials and Methods: In this study, 101 gastric tissue samples which were included in tissue microarray were immunohistochemically examined for overexpression of HER2/neu. Chromogenic in situ hybridization (CISH) was used for HER-2/neu amplification. The correlation of HER2/neu amplification with clinicopathological parameters was also assessed. In addition, concordance between CISH and IHC was detected. Results: This study demonstrated a significant difference in the overexpression of HER2/neu in gastric tumors. The overexpression of HER2/neu was significantly higher in intestinal type, poorly differentiated grade, large size ($5cm{\leq}$) and positive nodal involvement tumors (p-value=0.041, 0.015, 0.038 and 0.071, respectively). Also, amplification of HER2/neu according to CISH test, had a significant positive correlation with tumor size and tumor type (p-value=0.018 and 0.058, respectively).Concordance between CISH and IHC was 76.9% in 101 evaluable samples. Conclusions: IHC/CISH differences were attributed to basolateral membranous immunoreactivity of glandular cells resulting in incomplete membranous reactivity and/or a higher rate of tumor heterogeneity in gastric cancers compared to breast cancers. Therefore, this can be a potential marker for targeted therapy of malignant gastric tumors.