• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.46-51
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• 2006

The inhibitory effects of flavanone derivatives on Helicobacter pylori (HP) growth, infection and VacA toxininduced vacuolation were investigated. Among flavanones tested, ponciretin potently inhibited the growth of HP with a MIC value of 0.01 mg/ml and VacA toxin-induced vacuolation in HeLa cells with $IC_{50}$ value of 0.078 mM. However, other flavanones inhibited neither HP growth nor VacA toxininduced vacuolation. All flavanones tested did not inhibit HP infection to KATO III cells. Ponciretin also inhibited activation of procaspase-3 to caspase-3 in HeLa cell induced by HP VacA toxin, but did not affect Bax and Bcl-2 protein levels. These findings indicate that ponciretin inhibits growth as well as vacuolation by HP VacA toxin, which induces cell death via proteolytic activation of a cascade of caspases.

• Journal of Radiation Protection and Research
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• v.36 no.1
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• pp.8-16
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• 2011

We manufactured the Vac-lok that can be applied to patient of special body shape and need to special set-up position and evaluated the usefulness in the radiation therapy. The manufacture Vac-lok, It was used EVA resin and biobeadform of a diameter 1.5 mm. carried out the test of functionality, structural and analyzed the relative reproducibility of phantoms and patients. During the total period of radiation therapy, Vacuum pressure bring variety to a very small amount in the test of functionality of the manufacture Vac-lok. But It was a negligible quantity. The manufacture Vac-lok improved the relative reproducibility of phantoms than the existing Vac-lok and tolerance has a confidence less than 4% error. Also, relative reproducibility of patient increased error than phantom in the antero-posterior and lateral plan. However, the maximum set-up error was less than ${\pm}\;2.3$ mm. In conclusion, If tolerance set-up error of radiotherapy is less than ${\pm}\;3$ mm, the manufacture Vac-lok was enough possible to use and improvement of reproducibility, considering supply with the Vac-lok made to measure of special patient that produced at a low price and without delay.

• Archives of Plastic Surgery
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• v.35 no.4
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• pp.393-399
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• 2008

Purpose: Chronic infected wounds sustained over 4 weeks with exposed tendon or bone are difficult challenges to plastic surgeons. Vacuum assisted closure (VAC) device has been well used for the management of chronic wounds diminishing wound edema, reducing bacterial colonization, promoting formation of granulation tissue and local blood flow by negative pressure to wounds. But Commercial ready-made VAC device might have some difficulties to use because of its high expenses and heavy weight. So we modified traditional VAC device with silver dressing materials as topical therapeutic agents for control of superimposed bacterial wound infection such as MRSA, MRSE and peudomonas. Methods: We designed the modified VAC device using wall suction, 400 cc Hemovac and combined slow release silver dressing materials. We compared 5 consecutive patients' data treated by commercial ready-made VAC device(Group A) with 11 consecutive patients' data treated by modified VAC device combined with silver dressing materials(group B) from September 2004 to June 2007. Granulation tissue growth, wound discharge, wound culture and wound dressing expenses were compared between the two groups. Results: In comparison of results, no statistical differences were identified in reducing rate of wound size between group A and B. Wound discharge was significantly decreased in both groups. Modified VAC device with silver dressing materials showed advantages of convenience, cost effectiveness and bacterial reversion. Conclusion: In combination of modified VAC device and silver dressing materials, our results demonstrated the usefulness of managing chronic open wounds superimposed bacterial infection, cost effectiveness compared with traditional VAC device and improvement of patient mobility.

• Polymer(Korea)
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• v.25 no.5
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• pp.649-656
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• 2001

Miscibility of poly(4-vinylpyridine) (P4VP) blends with poly(vinyl acetate-co-vinyl alcohol) (VAc-VAL copolymers) was investigated as a function of comonomer composition of VAc-VAL copolymers. Differential scanning calorimetry (DSC) and thermo-optical microscopic (TOM) analysis confirmed that P4VP is miscible with VAc-VAL copolymers containing more than 30 mole% VAL. Fourier transform inflated (FT-IR) spectroscopic analysis revealed that the strong intermolecular hydrongen bonding interaction between the vinylpyridine and VAL hydroxyl group was formed. Theoretical phase diagram was constructed by the calculation using the Association model, a thermodynamic model for hydrogen-bonded polymer blend systems developed by Coleman et al. The calculated theoretical binodal phase diagrams were in good agreement with the experimentally determined cloud point curves.

• The Journal of Korean Society for Radiation Therapy
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• v.16 no.1
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• pp.67-72
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• 2004

Purpose : Patient immobilization is crucial factor for radiation therapy. Generally, we have been used vacuum bag immobilization device(Vac-Lock) for whole body immobilization. In order to easily set up of vacuum bag(Vac-Lock), we made a 3DCA(3-Dimensional Conformal Accessary). The purpose of this study is evaluation of effectiveness of 3DCA using Vack-Lock for patient immobilization. Materials and Methods : We made 3DCA(3-Dimensional Conformal Accessary) tool of wooden boards. The reasons to choice of wooden boards are its easily handling nature and cheap expenses. Results : (1) We reduced man power from $5{\sim}6$persons to 1person to make immobilizations, (2) Shortened work time from 1hour to within 10minutes. (3) Avoid a collision to treatment gantry head. (4) Its shapes are smart and clean. Conclusion : We have made and used 3DCA(3-Dimensional Conformal Accessary) tool was very effective and convenience for the patients and users.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.2
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• pp.137-142
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• 2004

Purpose: The resistance of H. pylori to clarithromycin is one of the major causes of eradication failure. In H. pylori, clarithromycin resistance is due to point mutation in 23S rRNA. The aims of this study were to investigate the mutation of 23S rRNA and to examine the association of cagA, vacA genotype and clarithromycin resistant genes. Methods: H. pylori DNA was extracted from antral biopsy specimens from 27 children with H. pylori infection. Specific polymerase chain reaction (PCR) assays were used for cagA and vacA. Mutations associated with clarithromycin resistance were detected by using PCR restriction fragment length polymorphism (RFLP) analysis of 23S rRNA gene. Results: A2143G mutation was detected in one case and A2144G in 4, indicating 18.5% were clarithromycin resistant. Among the total of 27, cagA was present in 25 (93%), vacA s1a/m1 in 6 (22%), s1a/m2 in 3 (11%), s1c/m1 in 16 (59%), and s1c/m2 in 1 (4%). All of the 5 clarithromycin resistant strains were cagA (+), among which 2 were s1a/m1 and 2 were s1c/m1. There was no relation between genotypes and clarithromycin resistant genes. Conclusion: Detection of H. pylori resistance to clarithromycin using PCR RFLP from biopsy specimens might be useful for the selection of antibiotics. Clarithromycin resistant genes are not associated with genotypes of cagA and vacA.

• Journal of Chest Surgery
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• v.56 no.3
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• pp.206-212
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• 2023

Background: Delayed sternal closure (DSC) is a useful option for patients with intractable bleeding and hemodynamic instability due to prolonged cardiopulmonary bypass and a preoperative bleeding tendency. Vacuum-assisted closure (VAC) has been widely used for sternal wound problems, but only rarely for DSC, and its efficacy for mediastinal drainage immediately after cardiac surgery has not been well established. Therefore, we evaluated the usefulness of DSC using VAC in adult cardiac surgery. Methods: We analyzed 33 patients who underwent DSC using VAC from January 2017 to July 2022. After packing sterile gauze around the heart surface and great vessels, VAC was applied directly without sternal self-retaining retractors and mediastinal drain tubes. Results: Twenty-one patients (63.6%) underwent emergency surgery for conditions including type A acute aortic dissection (n=13), and 8 patients (24.2%) received postoperative extracorporeal membrane oxygenation support. Intractable bleeding (n=25) was the most common reason for an open sternum. The median duration of open sternum was 2 days (interquartile range [25th-75th pertentiles], 2-3.25 days) and 9 patients underwent VAC application more than once. The overall in-hospital mortality rate was 27.3%. Superficial wound problems occurred in 10 patients (30.3%), and there were no deep sternal wound infections. Conclusion: For patients with an open sternum, VAC alone, which is effective for mediastinal drainage and cardiac decompression, had an acceptable superficial wound infection rate and no deep sternal wound infections. In adult cardiac surgery, DSC using VAC may be useful in patients with intractable bleeding or unstable hemodynamics with myocardial edema.

• Polymer(Korea)
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• v.29 no.3
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• pp.304-307
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• 2005

The acid-catalyzed hydrolysis reaction of poly(vinyl acetate) (PVAc) in water/acetic acid solution at $35^{circ}C$ was studied at two different solvent compositions. The mole fractions of vinyl acetate (Vac) and vinyl alcohol (VA) during the course of the reaction were determined by NMR, and the equilibrium constant $K_{eq}$ of the reaction was determined using the molar ratio of VAc to VA at the chemical equilibrium. $K_{eq}$ was 0.75 (${\pm}0.01$) when the VAc mole faction at the equilibrium was 0.78 (${\pm}0.01$) and it was 0.69 (${\pm}0.01$) when the VAc mole fraction was 0.57 (${\pm}$0.02). The reaction was found to be a pseudo 1-st order reaction with the rate coefficient at $3.4{\times}10^{-6}/sec$.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.1
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• pp.37-42
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• 2014

Purpose : At the time of the pelvis cancer radiation treatment using the belly board, set-up error is large because of a prone position. In order to improve the reproducibility, we made Vac-lock type belly board. In this study, we attempt to validate its utility. Materials and Methods : We compared belly board and Vac-lock type belly board through the OBI. OBI was performed three times with entire course of treatment and the setup errors in the direction of X axis, Y axis, Z axis were recorded and calculated the distance from the isocenter. Results : X axis, Y axis, Z axis setup errors with existing belly board were 0.32 cm, 0.41 cm, 0.29 cm. The setup errors with the vac-lock type belly board were 0.12 cm, 0.19 cm, 0.17 cm. Further, errors of 0~0.29 cm were increased from 48% to 83% when using VLT belly board. Error of 0.5 cm or more was reduced from 21% to 2%. Conclusion : Vac-lock type belly board is able to maintain the efficacy of existing and create to match the characteristics of the patient. Therefore We think that vac-lock type belly board is very useful in pelvic cancer patients.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.4
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• pp.26-33
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• 1993