• Journal of Korean Society of Forest Science
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• v.108 no.3
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• pp.357-363
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• 2019

This study was conducted to develop a stem volume table for Quercus acutissima in Korea by using Kozak's stem taper equation. In total, 2700 tree samples were collected around the country, and growth performance was investigated through compiling data on diameters by stem height and stem analysis. In order to test the stem taper equation's fitness, the fitness index (FI), bias, and mean absolute deviation (MAD) were analyzed. The fitness of the equation was estimated at 97%, bias as 0.017, and MAD turned out to be 1.118, respectively. Furthermore, there was a statistically significant volume difference between the current volume table and the new volume table (p = 0.0008, <0.005). The result indicates that using the new volume table that reflects the actual forest will reduce the loss when assessing wood resources and will improve the accuracy of forest statistics for national and local governments. A stem volume table, the main result of this research, which is utilized in the estimated stem taper equation, will provide growth information for Quercus acutissima, one of the main broadleaf species in Korea, and will function as a management indicator for rational forest management.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.40-47
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• 2007

The objectives of this study were to derive site index and stem volume prediction equation based on stem analysis data for Larix leptolepis in Jinan region. The function for site index was developed by algebraic difference equation method. Polymorphic site index family curves with base age of 40 were presented based on the Schumacher height equation. The best stem volume prediction equation was suggested as $V=0.00260+0.00000399D^2H$. The simultaneous F-test using this equation showed that the estimated tree stem volumes were not significantly different (${\alpha}=0.05$ level) from the observed stem volumes for model evaluation. Therefore, site index and volume prediction equations prepared in this study could provide an indication of site quality and basic information for making of yield table, and could be used for rational forest management of Larix leptolepis stands grown in Jinan region.

• The Korea Journal of Herbology
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• v.38 no.6
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• pp.29-44
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• 2023

Objectives : This study was planned to evaluate the therapeutic effectiveness and possible underlying mechanism of TPE (Tetrapanax papyrifer stem(inner part of the stem Extract) and AQE (Akebiae quinata stem Extract) on osteoarthritis. Methods : Osteoarthritis models were induced through intra-articular injection of MIA (monosodium iodoacetate) 50 μL with 80 mg/ml in rats. Excluding the normal group, Osteoarthritis-induced rats were divided into 4 groups (Control, INDO, TPE, AQE). The drug concentrations were indomethacin 5 mg/kg, TPE 200 mg/kg, and AQE 200 mg/kg, and were orally administered once a day for a couple of weeks. After drug supplementation, the effects of TPE and AQE were measured with serum diagnosis, western blotting, and histopathological staining. Results : It was found that the DPPH and ABTS free radical erasure ability of AQE was better than that of TPE. AQE administration improved rear limb overload and it led to relieving pain. Both PTE and AQE significantly reduced the expression of inflammatory mediators COX-2, iNOS, and inflammatory cytokine IL-1β and IL-6 by inhibiting the phosphorylation of IκBα and deactivating the pathway of NF-κBp65. On the other hand, TNF-α was significantly reduced only by administration of AQE. In addition, histopathological analysis showed that the administration of AQE compared to PTE suppressed cartilage degeneration and effectively suppressed damage to proteoglycan, a component of ECM. Conclusion : Reviewing these experimental results, TPE and AQE possessed the effect of delaying the progress of osteoarthritis and protecting cartilage. In addition, the results of this study show that AQE has a better cartilage protection effect than TPE.

• International Journal of Stem Cells
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• v.16 no.1
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• pp.1-15
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• 2023

Liver organoids have gained much attention in recent years for their potential applications to liver disease modeling and pharmacologic drug screening. Liver organoids produced in vitro reflect some aspects of the in vivo physiological and pathological conditions of the liver. However, the generation of liver organoids with perfusable luminal vasculature remains a major challenge, hindering precise and effective modeling of liver diseases. Furthermore, vascularization is required for large organoids or assembloids to closely mimic the complexity of tissue architecture without cell death in the core region. A few studies have successfully generated liver organoids with endothelial cell networks, but most of these vascular networks produced luminal structures after being transplanted into tissues of host animals. Therefore, formation of luminal vasculature is an unmet need to overcome the limitation of liver organoids as an in vitro model investigating different acute and chronic liver diseases. Here, we provide an overview of the unique features of hepatic vasculature under pathophysiological conditions and summarize the biochemical and biophysical cues that drive vasculogenesis and angiogenesis in vitro. We also highlight recent progress in generating vascularized liver organoids in vitro and discuss potential strategies that may enable the generation of perfusable luminal vasculature in liver organoids.

• Proceedings of the Korean Society of Toxicology Conference
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• 1998.10a
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• pp.60-60
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• 1998

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.457-468
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• 2023

The purpose of this study is to develop a high-speed combine harvester. The performance was evaluated by composing a dynamic simulation model of a threshing cylinder and analyzing the amount of threshed rice grain during threshing operations. The rotational speed of the threshing cylinder was set at 10 rpm intervals from 500 rpm until 540 rpm, based on the rated rotational speed of 507 rpm. The rice stem model was developed using the EDEM software using measured rice stem properties. Multibody dynamics software was utilized to model the threshing cylinder and tank comprising five sections below the threshing cylinder, and the threshing performance was evaluated by weighing the grain collected in the threshing tank during threshing simulations. The simulation results showed that section 1 and 2 threshed more grains compared to section 3 and 4. It was also found that when the threshing speed was higher, the larger number of grains were threshed. Only simulation was conducted in this study. Therefore, the validation of the simulation model is required. A comparative analysis to validate the simulation model by field experiment will be conducted in the future.

• Proceedings of the Zoological Society Korea Conference
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• 2005.08a
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• pp.19-19
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• 2005

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2004.10a
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• pp.98-99
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• 2004

• Journal of the Korean society of biological therapies in psychiatry
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• v.24 no.3
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• pp.142-155
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• 2018

Insomnia in patients with hematopoietic stem cell transplantation(HSCT) has been underdiagnosed and undertreated. This study reviewed the frequency, characteristics, physical and psychological effects, and treatments of insomnia in HSCT patients to highlight clinical importance in this specialized population. Furthermore, the authors intended to suggest a model that would conceptualize insomnia in the context of HSCT. In the pre-transplant period, about half of patients with HSCT suffered from sleep disturbance. A substantial number of patients experienced distressing insomnia during the HSCT procedure and recovered to the level of the pre-transplant period. However, sleep disruption could be a chronic symptom in HSCT survivors and could negatively impact quality of control, cancer-related fatigue(CRF), immune function, and psychological distress. The 3P's model(Predisposing, Precipitating, Perpetuating) explains insomnia in cancer population and could be also relevant to HSCT patients with specific consideration of CRF, graft-versus-host diseases, specific properties of hematological disease, and protective isolated milieu. Effective treatment of insomnia in HSCT includes non-pharmacological(e.g., cognitive behavioral therapy, environmental modification) and pharmacological interventions. The decision of pharmacological treatment should be based on the issue of safety due to high risk of potential drug-drug interactions. Screening, treatment, and further research of insomnia in HSCT patients using validated subjective and/or objective measures are warranted.

• Journal of The Korean Association For Science Education
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• v.36 no.1
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• pp.75-86
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• 2016

The purpose of the present study is to develop and validate an instrument to assess STEM career motivation. We developed 32 items for 7 constructs (i.e. education experience, career value, academic self-efficacy, career self-efficacy, career interest, parents' support, and career motivation) on STEM career motivation based on Social Cognitive Career Theory (SCCT; Lent et al.,1994). 767 first year high school students participated in this study. The items were validated by Messick's framework (1995). In this study, we examined the validity of items in four aspects (i.e. content, substantive, structural and generalizability of validity). Methodologically, we used Rasch analysis, Exploratory factor analysis, confirmative factor analysis based on structural equation modelling. We confirmed that our instrument with 32 items as valid and reliable for measuring the STEM career motivation. In addition, we tested the STEM career motivation model based on SCCT. Our model explained the data well, suggesting that external factors (education experience and parents' support) and cognitive factors (perception of value, self-efficacy and interest) were significantly related to STEM career motivation.