• Progress in Medical Physics
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• v.26 no.4
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• pp.193-200
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• 2015

The aim of this study is to present commissioning results of the ViewRay system. We verified safety functions of the ViewRay system. For imaging system, we acquired signal to noise ratio (SNR) and image uniformity. In addition, we checked spatial integrity of the image. Couch movement accuracy and coincidence of isocenters (radiation therapy system, imaging system and virtual isocneter) was verified. Accuracy of MLC positioing was checked. We performed reference dosimetry according to American Association of Physicists in Medicine (AAPM) Task Group 51 (TG-51) in water phantom for head 1 and 3. The deviations between measurements and calculation of percent depth dose (PDD) and output factor were evaluated. Finally, we performed gamma evaluations with a total of 8 IMRT plans as an end-to-end (E2E) test of the system. Every safety system of ViewRay operated properly. The values of SNR and Uniformity met the tolerance level. Every point within 10 cm and 17.5 cm radii about the isocenter showed deviations less than 1 mm and 2 mm, respectively. The average couch movement errors in transverse (x), longitudinal (y) and vertical (z) directions were 0.2 mm, 0.1 mm and 0.2 mm, respectively. The deviations between radiation isocenter and virtual isocenter in x, y and z directions were 0 mm, 0 mm and 0.3 mm, respectively. Those between virtual isocenter and imaging isocenter were 0.6 mm, 0.5 mm and 0.2 mm, respectively. The average MLC positioning errors were less than 0.6 mm. The deviations of output, PDDs between mesured vs. BJR supplement 25, PDDs between measured and calculated and output factors of each head were less than 0.5%, 1%, 1% and 2%, respectively. For E2E test, average gamma passing rate with 3%/3 mm criterion was $99.9%{\pm}0.1%$.

• Journal of the Korean Vacuum Society
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• v.22 no.2
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• pp.86-91
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• 2013

The optical properties of InAs quantum dots (QDs) grown on GaAs substrates grown by molecular beam epitaxy have been studied using photoluminescence (PL) and time-resolved PL measurements. InAs QDs were grown using an arsenic interruption growth (AIG) technique, in which the As flux was periodically interrupted by a closed As shutter during InAs QDs growth. In this study, the shutter of As source was periodically opened and closed for 1 (S1), 2 (S2), or 3 s (S3). For comparison, an InAs QD sample (S0) without As interruption was grown in a pure GaAs matrix for 20 s. The PL intensity of InAs QD samples grown by AIG technique is stronger than that of the reference sample (S0). While the PL peaks of S1 and S2 are redshifted compared to that of S0, the PL peak of S3 is blueshifted from that of S0. The increase of the PL intensity for the InAs QDs grown by AIG technique can be explained by the reduced InAs clusters, the increased QD density, the improved QD uniformity, and the improved aspect ratio (height/length). The redshift (blueshift) of the PL peak for S1 (S3) compared with that for S0 is attributed to the increase (decrease) in the QD average length compared to the average length of S0. The PL intensity, PL peak position, and PL decay time have been investigated as functions of temperature and emission wavelength. S2 shows no InAs clusters, the increased InAs QD density, the improved QD uniformity, and the improved QD aspect ratio. S2 also shows the strongest PL intensity and the longest PL decay time. These results indicate that the size (shape), density, and uniformity of InAs QDs can be controlled by using AIG technique. Therefore the emission wavelength and luminescence properties of InAs/GaAs QDs can also be controlled.

• The Journal of Engineering Geology
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• v.18 no.2
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• pp.167-176
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• 2008

The variation characteristics of groundwater level with distance from shoreline at Jeju Island was investigated using groundwater level data monitored from 257 wells for dry season (December 1998) and wet season (July 1997), respectively. Groundwater levels of the dry season were $7.46{\sim}203.8\;m$ with an average of 60.49 m, while those of the wet season were $4.01{\sim}204.10\;m$ with an average of 57.66 m. Groundwater level of the dry season was higher than that of the wet season, which was caused by heavy rains between June and October, 1998 at the Jeju Island. Correlation coefficients between altitude and groundwater level for dry and wet seasons were above 0.86, and those between dry season and wet season groundwater levels were very high above 0.95. 257 groundwater level data were classified at an interval of 500 m. Average values for altitude, groundwater levels and distance from shoreline were calculated for 17 intervals. Altitude and groundwater level fur dry and wet seasons at $0{\sim}4\;km$ intervals were increased with distance from shoreline, but those at $4{\sim}9\;km$ intervals were irregularity. Linear functions of the groundwater level for dry and wet seasons as distance from shoreline were estimated, and the coefficient of determinant at $0{\sim}4\;km$ interval data was higher than it at $0{\sim}9\;km$ interval data. Increasing rate of groundwater level at $0{\sim}4\;km$ intervals was more 2 times than it at $0{\sim}9\;km$ intervals. This results are caused by linear increase of groundwater level to 4 km from shoreline and by irregularity of groundwater level at the $4{\sim}9\;km$ intervals.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.287-295
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• 2021

As facilities such as dam reservoir wetlands and agricultural irrigation reservoir wetlands are built, sedimentation occurs over time through erosion, sedimentation transport, and sediment deposition. Sedimentation issues are very important for the maintenance of reservoir wetlands because long-term sedimentation of sediments affects flood and drought control functions. However, research on resignation has been estimated mainly by empirical formulas due to the lack of available data. The purpose of this study was to calculate and compare the sediment deposition rate by developing a multiple regression model along with actual data and empirical formulas. In addition, it was attempted to identify potential causes of collapse by applying it to 64 reservoir wetlands that suffered flood damage due to the long rainy season in 2020 due to reservoir wetland sedimentation and aging. For the target reservoir, 10 locations including the GaGog reservoir located in Miryang city, Gyeongsangnam province in South Korea, where there is actual survey information, were selected. A multiple regression model was developed in consideration of physical and climatic characteristics, and a total of four empirical formulas and sediment deposition rate were calculated. Using this, the error of the sediment deposition rate was compared. As a result of calculating the sediment deposition rate using the multiple regression model, the error was the lowest from 0.21(m³km²/yr) to 2.13(m³km²/yr). Therefore, based on the sediment deposition rate estimated by the multi-regression model, the change in the available capacity of reservoir wetlands was analyzed, and the effective storage capacity was found to have decreased from 0.21(%) to 16.56(%). In addition, the sediment deposition rate of the reservoir where the overflow damage occurred was relatively higher than that of the reservoir where the piping damage occurred. In other words, accumulating sediment deposition rate at the bottom of the reservoir would result in a lack of acceptable effective water capacity and reduced reservoir flood and drought control capabilities, resulting in reservoir collapse damage.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.3
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• pp.42-50
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• 2012

City squares are public open spaces which are closely related to the peoples daily lives. Most squares are located in the center of the city, and they are usually used for community gatherings and they are suitable for open markets, music concerts, political rallies, and other events. City squares also play an important role as a grand public place operating in multi functions that require involvement of more people. The purpose of this study is to examine satisfaction on the spatial components, characteristics, and the user satisfaction in City Squares. The slady also analyzed the relationship between the satisfaction about spatial components, characteristics and it also shows that the user satisfaction is followed. This study sites are made in 3 grand public places in the center of Seoul including the Seoul plaza, Cheonggye Plaza, and Gwanghwarnun Square. Data were analyzed using several statistical methods such as descriptive statistics, factor analysis, ANOVA, correlation and regression. Results of the study are as follows: First, factor analysis carried out to extract the various factors of satisfaction on the sites; spatial components, usability, amenity/security, and spatial characteristics. User satisfaction concerning usability factor was higher than the satisfaction of the other factors. This result represented that the slady sites play an important role to the public open spaces in the city. Second, users showed high user satisfaction to study sites, and user satisfaction rate toward the Gwanghwarnun Square is the highest because of its facility planuing. Finally, user satisfactim was strongly correlated on the usability factor of spatial planning. Also, the significant correlations between the user satisfaction and the other factors such as spatial components, security, and spatial characteristics of spatial planning are presented. Results of this study can help guide the planning and management of the city square as a public open space based on the understanding of user perception and satisfaction.

• The Journal of Internal Korean Medicine
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• v.45 no.3
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• pp.335-341
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• 2024

Objectives: Patients with cancer eventually fail to respond to therapy when malignant cells develop effective ways to evade immunosurveillance. Conventional cancer treatments, such as radiation therapy and chemotherapy, aim to cure the disease or prolong the patient's life. However, the toxicity and side effects of conventional treatments limit their efficacy. Herbal medicine is a typical complementary and integrative form of medicine for cancer treatment in Asia. This protocol evaluates the effectiveness of herbal medicines in improving the immune function of patients with cancer. Methods: The following electronic databases will be searched: MEDLINE via PubMed, EMBASE via Elsevier, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure (CNKI), and Korean databases including Regional Information Sharing Systems (RISS), National Digital Science Library (NDSL), and Oriental Medicine Advanced Searching Integrated System (OASIS). Additionally, prospective randomized controlled trials that evaluate the effectiveness of herbal medicines on immune function in patients with cancer will be included in this review. All outcomes related to the immune function of patients with cancer (e.g., CD3, CD4, CD8, CD4/CD8 ratio, CD19 (B cells), dendritic cells (CD11), CD56 (NK cells), and macrophages) will be included in this review. Results: This review is expected to provide data on the effectiveness of herbal medicines on improving immune functions in patients with cancers. Conclusion: This systematic review will help patients and clinicians establish new management options for cancer treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.78-83
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• 2011

The flower of Chrysanthemum morifolium Ramat. with antioxidant, anticancer, and anti-inflammatory functions has been a widely used traditional herb as a healthy beverage and medicine. The aim of the present study was to investigate a herb tea consisting of C. morifolium Ramat., Corni fructus and Schizandra chinensis Baillon for its hepatoprotective activity against $CCl_4$-induced toxicity in freshly isolated rat hepatocytes and antigenotoxic effect against oxidative stress induced DNA damage in human leukocytes. Three different compositions of the herb tea (Mix I, II, and III) were prepared by extracting with water at $90^{\circ}C$. Freshly isolated rat hepatocytes were exposed to $CCl_4$ along with/without various concentrations of each tea. Protection of rat primary cells against $CCl_4$-induced damage was determined by the MTT assay. The significant antihepatotoxic effect of the tea was shown in Mix I and II. The increased transaminase (AST and/or ALT) release in media of $CCl_4$ treated hepatocytes was significantly lowered by all the teas tested. The effect of the tea on DNA damage in human leukocytes was evaluated by Comet assay. All teas showed a protective effect against $H_2O_2$-induced DNA damage. From these results, it is assumed that herb tea based on C. morifolium Ramat., Corni fructus and Schizandra chinensis Baillon exerted antihepatotoxic and antigenotoxic effects.

• Journal of Life Science
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• v.21 no.11
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• pp.1625-1630
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• 2011

Heme oxygenase-1 (HO-1) is a stress-responsive protein that is known to regulate cellular functions such as cell proliferation, inflammation, and apoptosis. In this study, we investigated the role of NADPH oxidase on the expression of HO-1 in human liver hepatoma cell line HepG2. Diphenyleneiodonium (DPI), an NADPH oxidase inhibitor, markedly inhibited HO-1 expression and the nuclear translocation of transcription factor Nrf2 in cobalt protoporphyrin (CoPP) or hemin-treated HepG2 cells. Similarly, the knockdown of $p47^{phox}$, a cytosolic factor for NADPH oxidase activity, by siRNA inhibited the CoPP-induced expression of HO-1. In addition, GSHmee, an intracellular antioxidant, blocked the expression of HO-1 in CoPP-treated cells. Based on these results, we conclude that the blockage of NADPH oxidase with DPI or $p47^{phox}$ siRNA inhibits CoPP-induced HO-1 expression in HepG2 cells, and also suggest that the expression of HO-1 in CoPP-induced HepG2 cells is associated with increase of intracellular ROS by NADPH oxidase activity.

• Microbiology and Biotechnology Letters
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• v.38 no.1
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• pp.53-63
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• 2010

As one of the mucous components of Cheonggukjang, traditional fermented soybean paste, $\gamma$-PGA is a natural substance with diverse functions. In this paper, an in-vivo experiment has been performed using NC/Nga mice in order to find out the efficacy of $\gamma$-PGA in human atopic dermatitis. The NC/Nga mice with BMAC-induced atopic dermatitis were administered $\gamma$-PGA (PGA-HM) with 300 kDa and low-molecular $\gamma$-PGA (PGA-LM), respectively. As a result, a significant decrease in clinical skin severity score was detected in the group that was administered PGA-LM. In terms of serum IgE levels, a significant decline was observed in PGA-LM, compared to the control group. The serum IgG1 levels also decreased more in PGA-LM than in the control group. However, no significant difference was observed in both groups. To witness the induction of $CD4^+CD25^+foxp3^+$ Treg cells, mRNA was sampled from the back of PGA-HM- and PGA-LM-administered NC/Nga mice with atopic dermatitis. In terms of the production amount of foxp3 mRNA, which was measured in real-time PCR, the group that was administered PGA-LM was twice as high as the control group. According to a biopsy on the skin on the backs of the mice, the experimental group was also far lower than the control group in terms of epidermis thickness, mast cell infiltration and the number of $CCR3^+$ cells. Therefore, it has been confirmed that the atopic dermatitis symptoms decreased more in the PGA-LM-administered NC/Nga mice than the PGA-HM-administered group by facilitating $CD4^+CD25^+foxp3^+$ Treg cells and suppressing the activity of eosinophils and production of IgE and pro-inflammatory cytokines.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.976-982
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• 1998

The effects of the glycoprotein (PAG) isolated from Pteridium aquilinum on the immune function was examined in mice. PAG was intraperitoneally administered into BALB/C mice for 14 days and the antibody forming ability to hen egg lysozyme (HEL) and the blastogenic responses of splenocytes were measured. PAG treatment significantly increased antibody formation to HEL in a dose-dependent manner. Blatogenesis of splenocytes in response to lipopolysaccharide (LPS, B-cell specific mitogen) or phytohemagglutinin (PHA, T-cell specific mitogen) was also increased after treatment with PAG, indicating that the PAG increases both humoral and cellular immunities. To examine whether the immune function of PAG was via a direct effect on the lymphocytes, splenocytes were isolated from BALB/C mice, exposed to various concentrations of PAG in vitro and the blastogenic responses were measured. In vitro exposure to PAG significantly increased blastogenesis of splenocytes to LPS up to $500{\;}{\mu}g/kg$, whereas the blastogenic response to PHA was not altered by PAG treatment. To identify the fraction responsible for the increase in the immune function, the effect of periodate digest, pronase digest or purified polysaccharide on the antibody production to HEL was examined. Crude protein fraction of PAG significantly increased the antibody formation to HEL. On the other hand, both crude and purified polysaccharide fractions did not have any effects on the antibody production ability. These data indicated that 1) PAG increased both humoral and cellular immune functions, 2) the increase in humoral immunity was probably via a direct action of PAG on lymphocytes and 3) the protein portion of PAG was responsible for the increase in humoral immunity.