• Journal of Korean Dental Science
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• v.16 no.2
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• pp.128-148
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• 2023

Dementia is an umbrella term that describes the loss of thinking, memory, attention, logical reasoning, and other mental abilities to the extent that it interferes with the activities of daily living. More than 50 million individuals worldwide live with dementia, which is expected to increase to 131 million by 2050. Recent research has shown that poor oral health increases the risk of dementia, while oral health declines with cognitive decline. In this narrative review, the literature was based on the "hypothesis" that dementia and oral health have a close relationship, and appropriate oral health and occlusal rehabilitation treatment can improve the quality of life of patients with dementia and prevent progression. We conducted a literature search in PubMed and Google Scholar databases, using the search terms "dementia," "major neurocognitive disorder," "dentition," "occlusion," "tooth loss," "dental prosthesis," "dental implant," and "occlusal rehabilitation" in the title field over the past 30 years. A total of 131 studies that scientifically addressed dementia, oral health, and/or oral rehabilitation were included. In a meta-analysis, the random effect model demonstrated significant tooth loss increasing the dementia risk 3.64-fold (pooled odds ratio=3.64, 95% confidence interval [2.50~5.32], P-value=0.0348). Tooth loss can be an important indicator of cognitive function decline. As the number of missing teeth increases, the risk of dementia increases. Loss of teeth can lead to a decrease in the ascending information to the brain and reduced masticatory ability, cerebral blood flow, and psychological atrophy. Oral microbiome dysbiosis and migration of key bacterial species to the brain can also cause dementia. Additionally, inflammation in the oral cavity affects the inflammatory response of the brain and the complete body. Conversely, proper oral hygiene management, the placement of dental implants or prostheses to replace lost teeth, and the restoration of masticatory function can inhibit symptom progression in patients with dementia. Therefore, improving oral health can prevent dementia progression and improve the quality of life of patients.

• International Journal of Oncology
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• v.54 no.4
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• pp.1327-1336
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• 2019

Endothelial progenitor cells (EPCs) are bone marrow (BM)-derived progenitor cells that can differentiate into mature endothelial cells, contributing to vasculogenesis in the blood vessel formation process. Runt-related transcription factor 3 (RUNX3) belongs to the Runt domain family and is required for the differentiation of specific immune cells and neurons. The tumor suppressive role of RUNX3, via the induction of apoptosis and cell cycle arrest in a variety of cancers, and its deletion or frequent silencing by epigenetic mechanisms have been studied extensively; however, its role in the differentiation of EPCs is yet to be investigated. Therefore, in the present study, adult BM-derived hematopoietic stem cells (HSCs) were isolated from Runx3 heterozygous (Rx3^+/-) or wild-type (WT) mice. The differentiation of EPCs from the BM-derived HSCs of Rx3^+/- mice was found to be significantly increased compared with those of the WT mice, as determined by the number of small or large colony-forming units. The migration and tube formation abilities of Rx3^+/- EPCs were also observed to be significantly increased compared with those of WT EPCs. Furthermore, the number of circulating EPCs, defined as CD34⁺/vascular endothelial growth factor receptor 2 (VEGFR2)⁺ cells, was also significantly increased in Rx3^+/- mice. Hypoxia-inducible factor (HIF)-1α was upregulated in Rx3^+/- EPCs compared with WT EPCs, even under normoxic conditions. Furthermore, in a hindlimb ischemic mouse models, the recovery of blood flow was observed to be highly stimulated in Rx3^+/- mice compared with WT mice. Also, in a Lewis lung carcinoma cell allograft model, the tumor size in Rx3^+/- mice was significantly larger than that in WT mice, and the EPC cell population (CD34⁺/VEGFR2⁺ cells) recruited to the tumor was greater in the Rx3^+/- mice compared with the WT mice. In conclusion, the present study revealed that Runx3 inhibits vasculogenesis via the inhibition of EPC differentiation and functions via the suppression of HIF-1α activity.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.457-474
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• 2003

The ultimate objective of periodontal treatment is to get rid of an on-going periodontal disease and further regenerate the supporting tissue, which is already destroyed, functionally. Currently, the bone grafting operation using various kinds of bone grafting materials and the operation for induced regeneration of periodontal tissue using the blocking membrane are performed for regeneration of the destroyed periodontal tissue. However, there are respective limitations Galenical preparations, which are used for regeneration of periodontal of tissue, has less risk of rejective reaction or toxicity that may be incidental to degradation and their effect is sustainable. Thus, in case they are applicable to a clinic, they can he used economically. Chitosan has such compatibility, biological actions including antibacterial activity, acceleration of wound treatment, etc., and excellent mechanical characteristics, which has recently aroused more interest in it. Also, it has been reported that it promotes osteogenesis directly or indirectly by functioning as a matrix to promote migration and differentiation of a specific precussor cell (for example, osteoblast) and further inhibiting the function of such a cell as fibroblast to prevent osteogenesis. In this study, the pure chitosan solution, which was obtained by purifying chitosan, was used. However, since this chitosan is of a liquiform, it is difficult to sustain it in a defective region. It is, therefore, essential to use a carrier for delivering chitosan to, and sustaining it gradually in the defective region. In the calvarial defect model of the Sprague-Dawley rat, it is relatively easy to maintain a space. Therefore, in this study, the chitosan solution with which ACS was wetted was grafted onto the defective region, For an experimental model, a calvarial defect of rat m s selected, and a critical size of the defective region was a circular defect with a diameter of 8 mm. A group in which no treatment was conducted for the calvarial defect was set as a negative control group. Another group in which treatment was conducted with ACS only was set as a positive control group (ACS group). And another group in which treatment was conducted was conducted with by grafting the pure chitosan solution onto the defective region through ACS which was wetted with the chitosan solution was set an experimental group (Chitosan/ACS group). Chitosan was applied to the Sprague-Dawley rat's calvarial bone by applying ACS which was wetted with the chitosan solution, and each Sprague-Dawley rat was sacrificed respectively 2 weeks and 8 weeks after the operation for such application. Then, the treatment results were compared and observed histologically and his tometrically. Thereby, the following conclusions were obtained. 1. In the experimental group, a pattern was shown that from 2 weeks after the operation, vascular proliferation proceeded and osteogenesis proceeded through osteoblast infiltration, and at 8 week after the operation, ACS was almost absorbed, the amount of osteogensis was increased and many osteoid tissue layers were observed. 2. At 2 weeks after the operation, each amount of osteogenesis appeared to be 8.70.8 %, 13.62.3 % and 4.80.7 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be higher in the Experimental group and the positive control group than in the negative control group, but there was no significant difference statistically (p<0.01). 3. At 8 weeks after the operation, each amount of osteogenesis appeared to be 62.26.1%, 17.42.5 % and 8.21.4 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be substantially higher in the experimental group than in the positive control group and the negative control group, and there was a significant difference statistically (p<0.01). As a result of conducting the experiment, when ACS was used as a carrier for chitosan, chitosan showed effective osteogenesis in the perforated defective region of the Sprague-Dawley rat's calvarial bone.

• Journal of Acupuncture Research
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• v.24 no.6
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• pp.1-14
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• 2007

Backgrounds : Rheumatoid Arthritis(RA) is known as the chronic inflammatory diseasethat induces persistent inflammation in the joint cavity. The destruction of cartilage occurs as the result of bones destoyed by pannus, several influential cytokines induced by the synovial capsulitis, varieties of proteinases, $O_2$ radicals, and the secondary degenerative changes of articular cartilage. The type 2 collagen-induced arthritis model is used in recent experimental research on rheumatoid arthritis. Cervus elaphus sibiricus (Nockyong) has the effect of relieving pain by nourishing the muscles, joints, and bones. It is also known to be efficacious in promoting and enhancing the immune system. The objective of this study was to investigate the effect of Cervus elaphus sibiricus herbal acupuncture to inhibit the generation of proinflammatory enzyme on type 2 collagen-induced arthritis. I investigated the inhibition of mRNA transcription of MIF(macrophage migration inhibitory factor), $TNF-{\alpha}$(Tumor necrosis $factor-{\alpha}$) and MMP-9 (matrix metalloproteinase-9) of Cervus elaphus sibiricus herbal acupuncture using an in vitro test. Also investigated was the inhibition of differentiation of Th 1 cells and activation of cytokines(MIF, $TNF-{\alpha}$, IL-6, MMP-9), which are known to cause initial RA ,and are also related to the morphology of the synovial membranes of the joint capsule, by an in vivo test, using CIA(collagen induced arthritis) model mice. Materials & methods : The laboratory animals used in this experiment were 4 week-old DBA female mice, weighing approximately 20 grams, and adjusted to the laboratory environment. The experiment was divided into the normal group(NOR)-no treated group, control group(CON)-CIA induced group, and sample group(SAM)-Cervus elaphus sibiricus herbal acupuncture treated group. RA was induced in the mice via injection of $50{\mu}{\ell}$ C II mixed CFA. The Cervus elaphus sibiricus herbal acupuncture solution was applied on $GB_{35}$(陽陵泉) for 26 days from the 3rd day of RA inducement. The concentration of the solution was determined via a MTT assay. To research the effect on the expression of MIF, $TNF-{\alpha}$ and MMP-9 mRNA, RT-PCR was performed on synovial membrane cells from the knee joint of CIA mice. C II induced RA knee joint's histo-chemical synovial membrane was observed using a specimen model via the Hematoxilin and Eosin dying technique. Results : The expression of mRNA of RA-related cytokines such as MIF, $TNF-{\alpha}$, and MMP-9 dosedependently decreased in the cell from the synovial membranes of the joint, which is treated with Cervus elaphus sibiricus herbal acupuncture solution. In mice treated with Cervus elaphus sibiricusherbal acupuncture, the damage of synovial membranes of the joint was lessened, and differentiation of Th 1 cells was suppressed. The activation of RA-related cytokines such as MIF was suppressed, and the generation of $TNF-{\alpha}$ and MMP-9 showed a statistically significant decreas. Conclusions : It is speculated that Cervus elaphus sibiricus herbal acupuncture has the therapeutic effect of palliating the damage of the tissue impaired by RA by inhibition of the initial RA progression and by regulating excessive differentiation of Th 1 cell as it suppresses the generation of RA-related cytokines during the highest stage of RA by acting on pro-inflammatory enzymes.

• Journal of Korea Soil Environment Society
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• v.4 no.1
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• pp.109-118
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• 1999

Recently, transport parameters of conservative solutes such as KCl in a porous medium have been successfully determined using time domain reflectometry (TDR) . This study was initiated to Investigate the applicability of TDR technique to monitoring the fate of a heavy metal ion in a sandy soil and the distribution of its concentration along travel distance with time. A column test was conducted in a laboratory that consists of monitoring both resident and flux concentrations of $ZnCl_2$in a sandy soil under a breakthrough condition. A tracer of $ZnCl_2$(10 g/L) was injected onto the top surface of the sample as pulse type as soon as a steady-state condition was achieved. Time-series measurements of resistance and electrical conductivity were performed at 10 cm and 20 cm of distances from the inlet boundary by horizontal-positioning of parallel TDR metallic rods and using an EC-meter for the effluent exiting the bottom boundary respectively. In addition. Zn ions of the effluent were analyzed by ICP-AES. Since the mode and position of concentration detected by TDR and effluent were different, comparison between ICP analysis and TDR-detected concentration was made by predicting flux concentration using CDE model accommodating a decay constant with the transport parameters obtained from the resident concentrations. The experimental results showed that the resident concentration resulted in earlier and higher peak than the flux concentration obtained by EC-meter, implying the homogeneity of the packed sandy soil. A close agreement was found between the predicted from the transport parameters obtained by TDR and the measured $ZnCl_2$concentration. This indicates that TDR technique can also be applied to monitoring heavy metal concentrations in the soil once that a decay constant is obtained for a given soil.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.161-171
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• 1999

Background: Interleukin-12 (IL-12) can induce antitumor effects in vivo. This antitumor effect is associated with T cell infiltration but the effect of IL-12 on the steps of T cell migration into the tumor tissue has not been fully elucidated. This study focused on the effect of IL-12 on the tumor growth and the metastasis and on the expression of E-selectin, an adhesion molecule which is activated endothelial specific in its expression. In addition, we studied whether the expression of E-selectin is associated with the TNF-$\alpha$, a cytokine that its production is increased by IL-12 and has functions inducing a variety of adhesion molecules. Methods: Mice of C57BL/6 strain were injected with Lewis lung cancer cells followed by either IL-12, TNF-$\alpha$, or normal saline by intraperitoneal route. Twenty eight days after tumor cell inoculation, metastatic nodules of lung were enumerated and immunohistochemical staining of the subcutaneous tumors were performed with monoclonal antibodies to CD4, CD8, CD16, and E-selectin. In IL-12 treated mice, the subcutaneously implanted Lewis lung tumors were decreased in size and the metastases were also decreased in number compared to control mice. On tumor tissues, increased infiltration of CD4+, CD8+, and CD16+ cells were oberved in IL-12 treated mice compared to control mice. In control mice, E-selectin was absent on tumor vessels, but the expression of E-selectin was increased on tumor vessels of IL-12 treated mice. Administration of TNF-$\alpha$ increased not only the expression of E-selectin but also infiltrations of CD4+, CD8+, and CD16+ cells on tumor tissues. Conclusions: These results demonstrate that IL-12 inhibits tumor growth and metastases through infiltrations of inflammatory cells in mouse model of Lewis lung carcinoma and E-selectin may playa role in inflammatory cell recruitment on tumor tissue following IL-12 administration. Also, TNF-$\alpha$ may have a role as a mediator responsible for the IL-12 induced expression of E-selectin.

• Economic and Environmental Geology
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• v.48 no.1
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• pp.25-39
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• 2015

$CO_2$ geological storage plays an important role in reduction of greenhouse gas emissions, but there is a lack of research for CCS demonstration. To achieve the goal of CCS, storing $CO_2$ safely and permanently in underground geological formations, it is essential to understand the characteristics of them, such as total storage capacity, stability, etc. and establish an injection strategy. We perform the impedance inversion for the seismic data acquired from the Ulleung Basin in 2012. To review the possibility of $CO_2$ storage, we also construct porosity models and extract attributes of the prospects from the seismic data. To improve the quality of seismic data, amplitude preserved processing methods, SWD(Shallow Water Demultiple), SRME(Surface Related Multiple Elimination) and Radon Demultiple, are applied. Three well log data are also analysed, and the log correlations of each well are 0.648, 0.574 and 0.342, respectively. All wells are used in building the low-frequency model to generate more robust initial model. Simultaneous pre-stack inversion is performed on all of the 2D profiles and inverted P-impedance, S-impedance and Vp/Vs ratio are generated from the inversion process. With the porosity profiles generated from the seismic inversion process, the porous and non-porous zones can be identified for the purpose of the $CO_2$ sequestration initiative. More detailed characterization of the geological storage and the simulation of $CO_2$ migration might be an essential for the CCS demonstration.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.2
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• pp.76-88
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• 2017

The urban park plays important roles in protecting the urban landscape and improving citizens' health, recreation, and the emotional life. Above and beyond these roles, the urban park is expected to rearrange urban spatial structures as a kind of urban system. The purpose of this paper is to identify empirically to change urban spatial structures by construction of the urban park. This study regards gentrification around the urban park as a process to change urban spatial structures. The gentrification means the regeneration and upgrading of deteriorated urban property by the middle class or commercial developers. The site of case analysis is the Seoul Forestry Park in Sungdong-gu, Seoul. The Seoul Forestry Park is regarded as a representative urban park of Seoul, and caused gentrification around park after the 2005 opening. This study operationally defines the gentrification index and the accessibility index from an urban park and offers an empirical analysis of relation among the urban park, the gentrification and urban spatial structure in a statistic district which is the minimum unit of Korean statistic data in 2000, 2005, and 2010, using Difference-in-Difference method and linear probability model. The results of this empirical study show that the Seoul Forestry Park changes urban spatial structures by gentrification. It reverses a trend of migration of gentrifiers before and after construction of the Seoul Forestry Park. It suggests urban park construction as an alternative method for urban regeneration by inducing the middle class into the inner city of Seoul.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.7-17
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• 2005

The determination of seismic velocities in refractors for near-surface seismic refraction investigations is an ill-posed problem. Small variations in the computed time parameters can result in quite large lateral variations in the derived velocities, which are often artefacts of the inversion algorithms. Such artefacts are usually not recognized or corrected with forward modelling. Therefore, if detailed refractor models are sought with model based inversion, then detailed starting models are required. The usual source of artefacts in seismic velocities is irregular refractors. Under most circumstances, the variable migration of the generalized reciprocal method (GRM) is able to accommodate irregular interfaces and generate detailed starting models of the refractor. However, where the very-near-surface environment of the Earth is also irregular, the efficacy of the GRM is reduced, and weathering corrections can be necessary. Standard methods for correcting for surface irregularities are usually not practical where the very-near-surface irregularities are of limited lateral extent. In such circumstances, the GRM smoothing statics method (SSM) is a simple and robust approach, which can facilitate more-accurate estimates of refractor velocities. The GRM SSM generates a smoothing 'statics' correction by subtracting an average of the time-depths computed with a range of XY values from the time-depths computed with a zero XY value (where the XY value is the separation between the receivers used to compute the time-depth). The time-depths to the deeper target refractors do not vary greatly with varying XY values, and therefore an average is much the same as the optimum value. However, the time-depths for the very-near-surface irregularities migrate laterally with increasing XY values and they are substantially reduced with the averaging process. As a result, the time-depth profile averaged over a range of XY values is effectively corrected for the near-surface irregularities. In addition, the time-depths computed with a Bero XY value are the sum of both the near-surface effects and the time-depths to the target refractor. Therefore, their subtraction generates an approximate 'statics' correction, which in turn, is subtracted from the traveltimes The GRM SSM is essentially a smoothing procedure, rather than a deterministic weathering correction approach, and it is most effective with near-surface irregularities of quite limited lateral extent. Model and case studies demonstrate that the GRM SSM substantially improves the reliability in determining detailed seismic velocities in irregular refractors.

• Land and Housing Review
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• v.12 no.2
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• pp.47-59
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• 2021

This study aims to review the trends of the population outflows in the metropolitan area of Busan and to investigate the factors that affect population out-migration to the Seoul metropolitan area. The following variables are considered for analysis: traditional population movement variables and quality of life variables, such as population, society, employment, housing, culture, safety, medical care, greenery, education, and childcare. The 'domestic population movement data', provided by the MDIS of the National Statistical Office, was used for this research. Out of the total of 57 million population movement data in the period 2012 - 2017, population outmigration from Busan to the Seoul metropolitan area was extracted. Independent variables were drawn from public data sources in accordance with the temporal and spatial settings of the study. The multiple linear regression model was specified based on the dataset, and the fit of the model was measured by the p-value, and the values of Adjusted R2, Durbin-Watson analysis, and F-statistics. The results of the analysis showed that the variables that have a significant effect on population movement from Busan to the Seoul metropolitan area were as follows: 'single-person households', 'the elderly population', 'the total birth rate', 'the number of companies', 'the number of employees', 'the housing sales price index', 'cultural facilities', and 'the number of students per teacher'. More positive (+) influences of the population out-movement were observed in areas with higher numbers of single-person households, lowers proportions of the elderly, lower numbers of businesses, higher numbers of employees, higher numbers of housing sales, lower numbers of cultural facilities, and lower numbers of students. The findings suggest that policies should enhance the environments such as quality jobs, culture, and welfare that can retain young people within Busan. Improvements in the quality of life and job creation are critical factors that can mitigate the outflows of the Busan residents to the Seoul metropolitan area.