• Title/Summary/Keyword: Byung-cheon Park

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Preoperative chemoradiotherapy followed by local excision in clinical T2N0 rectal cancer

  • Shin, Young Seob;Yoon, Yong sik;Lim, Seok-Byung;Yu, Chang Sik;Kim, Tae Won;Chang, Heung Moon;Park, Jin-hong;Ahn, Seung Do;Lee, Sang-Wook;Choi, Eun Kyung;Kim, Jin Cheon;Kim, Jong Hoon
    • Radiation Oncology Journal
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    • v.34 no.3
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    • pp.177-185
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    • 2016
  • Purpose: To investigate whether preoperative chemoradiotherapy (PCRT) followed by local excision (LE) is feasible approach in clinical T2N0 rectal cancer patients. Materials and Methods: Patients who received PCRT and LE because of clinical T2 rectal cancer within 7 cm from anal verge between January 2006 and June 2014 were retrospectively analyzed. LE was performed in case of a good clinical response after PCRT. Patients' characteristics, treatment record, tumor recurrence, and treatment-related complications were reviewed at a median follow-up of 49 months. Results: All patients received transanal excision or transanal minimally invasive surgery. Of 34 patients, 19 patients (55.9%) presented pathologic complete response (pCR). The 3-year local recurrence-free survival and disease free-survival were 100.0% and 97.1%, respectively. There was no recurrence among the patients with pCR. Except for 1 case of grade 4 enterovesical fistula, all other late complications were mild and self-limiting. Conclusion: PCRT followed by an LE might be feasible as an alternative to total mesorectal excision in good responders with clinical T2N0 distal rectal cancer.

Case Study on Stability Assessment of Pre-existing Fault at CO2 Geologic Storage (CO2 지중저장 시 단층 안정성 평가)

  • Kim, Hyunwoo;Cheon, Dae-Sung;Choi, Byung-Hee;Choi, Hun-Soo;Park, Eui-Seob
    • Tunnel and Underground Space
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    • v.23 no.1
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    • pp.13-30
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    • 2013
  • Increase of pore fluid pressure resulting from injection of $CO_2$ may reactivate pre-existing faults, and the induced seismic activities can raise the safety issues such as seal integrity, restoration of storage capacity, and, in the worst case, removal of previously injected $CO_2$. Thus, fault stability and potential for $CO_2$ leakage need to be assessed at the stage of site selection and planning of injection pressure, based on the results of large-scale site investigations and numerical modeling for various scenarios. In this report, studies on the assessment of fault stability during injection of $CO_2$ were reviewed. The seismic activities associated with an artificial injection of fluids or a release of naturally trapped high-pressure fluids were first examined, and then site investigation methods for the magnitude and orientation of in situ stresses, the distribution and change of pore fluid pressure, and the location of faults were generally summarized. Recent research cases on possibility estimation of fault reactivation, prediction of seismic magnitude, and modeling of $CO_2$ leakage through a reactivated fault were presented.

Molecular Mechanism of Tetrabromobisphenol A (TBBPA)-induced Target Organ Toxicity in Sprague-Dawley Male Rats

  • Choi, Jae-Seok;Lee, Young-Jun;Kim, Tae-Hyung;Lim, Hyun-Jung;Ahn, Mee-Young;Kwack, Seung-Jun;Kang, Tae-Seok;Park, Kui-Lea;Lee, Jae-Won;Kim, Nam-Deuk;Jeong, Tae-Cheon;Kim, Sang-Geum;Jeong, Hye-Gwang;Lee, Byung-Mu;Kim, Hyung-Sik
    • Toxicological Research
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    • v.27 no.2
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    • pp.61-70
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    • 2011
  • Brominated flame retardants (BFRs) are present in many consumer products ranging from fabrics to plastics and electronics. Wide use of flame retardants can pose an environmental hazard, which makes it important to determine the mechanism of their toxicity. In the present study, dose-dependent toxicity of tetrabromobisphenol A (TBBPA), a flame retardant, was examined in male prepubertal rats (postnatal day 18) treated orally with TBBPA at 0, 125, 250 or 500 mg/kg for 30 days. There were no differences in body weight gain between the control and TBBPA-treated groups. However, absolute and relative liver weights were significantly increased in high dose of TBBPA-treated groups. TBBPA treatment led to significant induction of CYP2B1 and constitutive androstane receptor (CAR) expression in the liver. In addition, serum thyroxin (T4) concentration was significantly reduced in the TBBPA treated group. These results indicate that repeated exposure to TBBPA induces drug-metabolising enzymes in rats through the CAR signaling pathway. In particular, TBBPA efficiently produced reactive oxygen species (ROS) through CYP2B1 induction in rats. We measured 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage, in the kidney, liver and testes of rats following TBBPA treatment. As expected, TBBPA strongly induced the production of 8-OHdG in the testis and kidney. These observations suggest that TBBPA-induced target organ toxicity may be due to ROS produced by metabolism of TBBPA in Sprague-Dawley rats.

Development of Herbal Chicken Porridge and the Establishment of Optimizing the Mixing Ratio (한방 닭죽 개발 및 최적 배합비율 확립)

  • Kim, Kyung-Yeon;Baik, Moo-Yeol;Park, Cheon-Seok;Choi, Sung-Won;Kim, Chang-Nam;Kim, Byung-Yong
    • The Korean Journal of Food And Nutrition
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    • v.26 no.1
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    • pp.22-28
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    • 2013
  • The objectives of this study were to develop porridge with medicinal herbs and chicken breast meat and to find out the optimum mixing ratio. Several herb extracts such as Acanthopanacis senticosus, Rehmannia glutinosa, Disocorea japonica, and Poria cocos Wolf were used in the ratio of 2, 1, 1, and 1, respectively. The optimum processing condition for herbal chicken porridge was determined by a design expert program. Seventeen experimental points were selected, and herb extracts (82~101 g), chicken breast meat (30~50 g), and glutinous rice (40~60 g) were chosen as the independent variables. The measured responses were preference of taste, DPPH radical scavenging, SOD-like activity, and cost. The optimum formulation of herbal chicken porridge using the numerical analysis was set at herbal extracts (101 g), chicken breast meat (38.66 g), and glutinous rice (41.34 g) with a 0.714 desirability value. DPPH radical scavenging effect, preference of taste and the cost showed a linear model, whereas SOD-like activity showed a quadratic model indicating a higher interaction among the mixture. As a result of proximate composition of optimized herbal chicken porridge, the contents of moisture, carbohydrate, crude protein, crude lipid, and ash contents were 76.4, 9.0, 1.4, 0.5, and 1.6%, the calories of the porridge was 46.1 kcal/100 g.

Study on the Selection of Solvent for Purificatino of p-Dioxanone by Crystallization Method (결정화에 의한 파라디옥산온의 정제를 위한 용매선정에 관한 연구)

  • kim, Sung-Il;Koh, Joo-young;Kim, Chul-Ung;Koh, Jae-Cheon;Park, So-Jin;Seo, Young-Jong;Choi, Byung-Ryul
    • Applied Chemistry for Engineering
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    • v.16 no.4
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    • pp.581-587
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    • 2005
  • In order to obtain a highly purified p-dioxanone (PDX) as monomer of biodegradable polymer, suitable solvent must be selected. The selection was based on the solubility of impurities, and partial layer melt crystallization were carried out under the presence of solvent. The solubility of PDX in various solvents such as ethyl acetate, tetrahydrofuran, acetone, alcohols (methanol, ethanol, 1-propanol, 1-butanol and 1-pentanol) were measured over the temperature range of $-10{\sim}15^{\circ}C$. As solubility parameters, the mixing and dissolution enthalpy between the PDX and the solvents was studied based on empirical equations and the regular solution theory. The solubility and the temperature dependency of the solubility with the solvents of acetone, ethylacetate, and tetrahydrofuran of PDX were shown to have relatively high values compared to the alcohol type solvents. Also, in same alcohols, the smaller molecules and higher polarity gave higher solvency. In partial layer melt crystallization, small amount of ethylacetate selectively dissolved impurities and gave highly purified p-dioxanone, over 99.9% purity.

Nano-safety Management and Exposure Assessment of Nanomaterials Producing Facilities (나노물질 생산시설의 환경노출 평가와 안전관리)

  • Umh, Ha Nee;Roh, Jinkyu;Park, Junsu;Kwak, Byoung Kyu;Lee, Byung Cheon;Choi, Kyunghee;Yi, Jongheop;Kim, Younghun
    • Korean Chemical Engineering Research
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    • v.50 no.1
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    • pp.112-117
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    • 2012
  • With the development of nanotechnology, nano-consumer products have been popularized. For the past 10 years, potential risk of nanomaterials to human and environment have been raised carefully. Especially, workers, who directly handle nanomaterials in laboratories and manfacturers, will lead to direct exposure of nanomaterials. Therefore, direct exposure assessment and field monitoring of nanomaterials are required to assess and manage the nanomaterial exposure to human and environment. In this work, two nano-manufacturing companies, which had plasma and sol-gel processes, were selected to analyze the main exposure source and process with in-situ SMPS (scanning mobility particle sizer) and ex-situ TEM (transmission electron microscopy). The results showed that the colloidal nanoparticle in liquid phase was easily evaporated and monitored by SMPS. Most serious thing is that the workers does not know about the potential risk of nanomaterials, and thus they are not taking proper protection activities, such as PPE (personal protective equipment). Therefore, exposure assessment for nanomaterial handling facilities should be additionally carried out, and nano-safety management protocols are also provided.

Feasibility study of a dedicated nuclear desalination system: Low-pressure Inherent heat sink Nuclear Desalination plant (LIND)

  • Kim, Ho Sik;NO, Hee Cheon;Jo, YuGwon;Wibisono, Andhika Feri;Park, Byung Ha;Choi, Jinyoung;Lee, Jeong Ik;Jeong, Yong Hoon;Cho, Nam Zin
    • Nuclear Engineering and Technology
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    • v.47 no.3
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    • pp.293-305
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    • 2015
  • In this paper, we suggest the conceptual design of a water-cooled reactor system for a low-pressure inherent heat sink nuclear desalination plant (LIND) that applies the safety-related design concepts of high temperature gas-cooled reactors to a water-cooled reactor for inherent and passive safety features. Through a scoping analysis, we found that the current LIND design satisfied several essential thermal-hydraulic and neutronic design requirements. In a thermal-hydraulic analysis using an analytical method based on the Wooton-Epstein correlation, we checked the possibility of safely removing decay heat through the steel containment even if all the active safety systems failed. In a neutronic analysis using the Monte Carlo N-particle transport code, we estimated a cycle length of approximately 6 years under 200 $MW_{th}$ and 4.5% enrichment. The very long cycle length and simple safety features minimize the burdens from the operation, maintenance, and spent-fuel management, with a positive impact on the economic feasibility. Finally, because a nuclear reactor should not be directly coupled to a desalination system to prevent the leakage of radioactive material into the desalinated water, three types of intermediate systems were studied: a steam producing system, a hot water system, and an organic Rankine cycle system.

Congener Specific Profiles and Exposure Pathways of Polybrominated Diphenyl Ethers (PBDEs) in Breast Milk of Chuncheon Area (춘천지역 모유 중 폴리브롬화디페닐메테르(PBDEs)의 이성체별 분포특성과 노출경로)

  • We, Sung-Ug;Baek, In-Cheon;Park, Sang-Ah;Kang, Seong-Hoon;Cho, Yu-Jin;Cho, Bong-Hui;Yoon, Cho-Hee;Kim, Ki-Ho;Min, Byung-Yoon
    • Journal of Life Science
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    • v.20 no.3
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    • pp.356-364
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    • 2010
  • This study was carried out to investigate the exposure pathway of PBDEs in human breast milk collected from new mothers residing in Chuncheon, a comparatively clean area in Korea. The congeners of PBDE in 22 human breast milk samples were analyzed using a high resolution gas chromatography with a high resolution mass detector. The residue level of ${\sum}PBDEs$ was higher in primipara subjects than in multipara subjects (p<0.05). The levels in this study were similar to those of people in some Asian and European countries, but were lower than those of people in north America. In the congener profiles, BDE-47 (mean contribution=36.1%) was predominant, followed by BDE-153 (27%), BDE-99 (11.7%), BDE-100 (11.1%), BDE-28 (7.9%) and BDE-183 (3.5%). The sum of BDE-47 and BDE-153 accounted for more than 50% of ${\sum}PBDEs$ in most samples. BDE-47 was highly correlated with ${\sum}PBDEs$ (r=0.94, p<0.001). No strong trend was observed between PBDE levels and a number of key biological factors (women's age, weight, height and body mass index) examined in this study, however, weak correlations were observed in PBDE levels measured against dietary habits, particularly in fish consumption frequency. It seems that Korean people might be exposed to multiple sources including products of PBDEs, and particularly food resources.

Optical Clearing Agent Decreases Scattering of Stratum Corneum and Modulates Physical Properties of Corneocytes by Hydration (광산란 감소 물질에 의한 피부 각질층의 산란 감소 및 수화에 의한 각질세포의 물리적 특성에 대한 연구)

  • Jun, Seung-Hyun;Yeom, Jun-Seok;Ahn, Byung Jun;Park, Sun Gyoo;Lee, Cheon Koo;Lee, Seol-Hoon;Kang, Nae-Gyu
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.44 no.1
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    • pp.81-87
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    • 2018
  • The objective of this article is to provide analytical tools for the scattering of stratum corneum (SC) and to check whether the optical clearing agents (OCAs) could be applied in optics affecting the scattering reduction. Dark field images of tape striped corneocyte separates scattered light of the SC from others in vitro. Several optical clearing agents were tested to reduce the scattering. Physical properties of SC such as water contents, keratin configuration and volume after OCAs treatment were investigated by FT-IR and 3D laser microscope. Several reducing sugars, monomeric sugars, sugar alcohol, and hyaluronic acid, which were used as humectants in cosmetic field, also reduced scattering. However, unlike dehydration in optics, water penetrated into the keratin in SC and scattering was decreased at low concentration of OCAs. In that condition, the volume of corneocyte was increased and stiffness seemed to decrease. The analyzing of tape-stripped SC, showed the change of optical and physical properties of corneocyte by optical clearing agents. The hydration of SC layer by optical clearing agents decreased the scattering of corneocyte and thus improved the skin appearance and moisturizing effect, which are important benefits in the cosmetic field and could provide new possibility to develop skin care study targeting at SC.

Development of Clinical Practice Guidelines for Sasang Constitutional Medicine Symptomatology - Purpose, Development Strategy and Procedure - (사상체질병증 임상진료지침 개발 연구 - 목적, 개발 전략 및 절차 -)

  • Kim, Je-Shin;Hwang, Min-Woo;Lee, Jun-Hee;Lee, Eui-Ju;Koh, Byung-Hee;Yoo, Jung-Hee;Bae, Na-Young;Kim, Yun-Hee;Bae, Hyo-Sang;Joo, Jong-Cheon;Park, Hye-Sun;Shin, Mi-Ran;Yoo, Jun-Sang
    • Journal of Sasang Constitutional Medicine
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    • v.25 no.1
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    • pp.23-33
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    • 2013
  • Objectives This study was aimed to develop the clinical practice guidelines, which focuses on Sasang Constitutional Medicine symptomology. By developing clinical practice guidelines, we should present prevention, diagnosis, treatment and assessment of Sasang Constitutional Medicine. Methods We used the method of University of Michigan Health System Guidelines model. Electronic databases including English, Korean databases were systematically searched for clinical articles investigating Sasang Constitutional Medicine symptomology up to March 2010. And "Donguisusebowon-ShinChukbon" was basically used to develop clinical guidelines. Results and Conclusions 12,694 Articles were reviewed. Only 25 articles described adequate methods of this study. Using clinical practice guidelines, we can manage th quality of medicine, emphasis treatment appropriacy and educate patients and doctors. Finally We can get the Sasang Constitutional Medicine standardization and socioeconomic benefit.