• Korean Journal of Veterinary Research
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• v.61 no.2
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• pp.14.1-14.7
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• 2021

Biosilica is a silica-based substance derived from the cell walls (frustules) of diatoms. Recently, research into biosilica's biological functions is underway, but little has been reported on the effects of biosilica on immune cells. In this study, we investigated the effect of ionized biosilica water (iBW) on dendritic cells (DCs), which play crucial roles as antigen (Ag)-presenting cells. Treatment with iBW increased the expression of immune response-related markers, closely connected to the maturation of DCs, and the production of tumor necrosis factor-alpha. In addition, iBW-treated DCs (iBW-DCs) had a lower uptake of fluorescein isothiocyanate-dextran than that of control DCs. Mixed leukocyte response analysis used for measuring the Ag-presenting capability of DCs, showed iBW-DCs had a higher capability than that of control DCs. Interestingly, DCs treated with lipopolysaccharide (LPS) and iBW had a lower level of Ag-presenting capability than that of LPS-treated DCs. Taken together, the results indicate that iBW alone can mature DCs, but it decreases the Ag-presenting capability of DCs in the presence of LPS, a representative agent of inflammation. This study may provide valuable information regarding the effect of iBW on immune cells. Further research is needed to investigate how iBW induces the observed biphasic immunomodulatory activity.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2757-2760
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• 2003

본 논문에서는 심장 돌연사(sudden cardiac death, SCD)의 주된 원인인 세동(fibrillation)을 낮은 에너지에서 효율적으로 제거할 수 있는 biphasic 자동형 제세동기를 개발하였다. 개발한 제세동기는 고전압 충 방전부와 신호처리부를 포함하는 하드웨어와 세동검출 알고리즘과 시스템 제어 알고리즘의 소프트웨어로 구성하였다. 개발한 시스템의 안정성과 효용성을 검증하기 위하여, 실험실 환경에서 160 번의 연속적인 충 방전 테스트를 통하여 시스템의 안정성을 확인하였으며, ECG simulator 에서 발생되는 6 종의 세동신호를 적용하여 100％의 실시간 검출능력을 확인하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.35.2-35.2
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• 2011

In this study, hyaluronic acid (HyA) - Gelatin (Gel) hydrogels were prepared at ratio of 15:85 with the goal of obtaining a high uniform porosity and porous biocompatibility scaffold for bone tissue engineering applications. In order to develop a proper scaffold for bone implant application, a HyA-Gel hydrogel loaded in sponge Biphasic Calcium Phosphate (BCP) was prepared. To assay the cytocompatibility and cell behavior on the HyA-Gel hydrogel and HyA-Gel/BCP scaffold, cell attachment and spreading of MSCs seeded on the scaffolds were studied. An invivo study was performed for HyA-Gel/BCP scaffolds after 1 and 3 months implantation. Our results provide a novel and simple method to obtain an adequate scaffold for osteoblast cells and indicate that HyA-Gel hydrogel and HyA-Gel/BCP scaffold could be a good candidate for bone tissue engineering scaffolds.

• The Korean Journal of Cytopathology
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• v.14 no.2
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• pp.96-101
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• 2003

Synovial sarcoma is a rare soft tissue tumor accounting for 5-10% of soft tissue sarcomas. Most arise in the extremities and trunk, and a small proportion occur in the abdominal wall, head and neck legion, and mediastinum. It manifests different phenotypic subtypes that render their cytologic evaluation challenging. Moreover, cytomorphologic description of the epithelial component of synovial sarcoma is rare in Korea. We report a case of biphasic synovial sarcoma on the right lower extremity in a 49-year-old woman diagnosed by fine needle aspiration cytology. The aspirate was moderately cellular and composed of a mixture of tissue fragments and dissociated cells with bland chromatin, inconspicuous nucleoli, and oval to spindle-shaped cytoplasm. Mitosis was rare. A monolayer sheet of epithelial component was seen. The cells in this monolayer sheet had more abundant distinct cytoplasm, round nuclei, and prominent micronucleoli. Histologic examination showed a biphasic pattern consisting of mostly sarcomatous stroma and a few small glandular areas at the periphery of the tumor.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.613-621
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• 2018

In this study, interface-assembled carbonyl reductase (IACR) was prepared and used in the synthesis of S-licarbazepine in a toluene/Tris-HCl biphasic system. The carbonyl reductase (CR) was conjugated with polystyrene to form a surfactant-like structure at the interface of the toluene/Tris-HCl biphasic system. The interface-assembled efficiency of IACR reached 83% when the CR (180 U/mg) and polystyrene concentration were $8{\times}10^2g/ml$ and $3.75{\times}10^3g/ml$, respectively. The conversion reached 95.6% and the enantiometric excess of S-licarbazepine was 98.6% when $3.97{\times}10^6nmol/l$ oxcarbazepine was converted by IACR using 6% ethanol as a co-substrate in toluene/Tris-HCl (12.5:10) at $30^{\circ}C$ and $43{\times}g$ for 6 h. IACR could be reused efficiently five times.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3743-3747
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• 2011

Kinetic studies on the reactions of Y-S-aryl phenyl phosphonochloridothioates with X-pyridines have been carried out in MeCN at $55.0^{\circ}C$. The Hammett and Bronsted plots for substituent X variations in the nucleophiles are biphasic concave upwards with a break point at X = H. The Hammett plots for substituent Y variations in the substrates are biphasic concave upwards with a break point at Y = H, and the sign of ${\rho}_Y$ is changed from unusual negative (${\rho}_Y$ < 0) with the weaker electrophiles to positive (${\rho}_Y$ > 0) with the stronger electrophiles. The stepwise mechanism is proposed on the basis of the ${\rho}_X$, ${\beta}_X$, and ${\rho}_{XY}$ values as follows: a ratelimiting leaving group departure from the intermediate involving a frontside attack and product-like TS for the stronger nucleophiles and weaker electrophiles; a rate-limiting leaving group departure from the intermediate involving a backside attack and product-like TS for the weaker nucleophiles and electrophiles; a rate-limiting bond formation involving a frontside attack for the stronger nucleophiles and electrophiles; a rate-limiting bond formation involving a backside attack for the weaker nucleophiles and stronger electrophiles. The substituent effects of X and Y on the pyridinolysis mechanisms of $R_1R_2P$(=S)Cl-type substrates are discussed.

• Journal of Periodontal and Implant Science
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• v.49 no.2
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• pp.114-126
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• 2019

Purpose: The aim of this study was to evaluate the enhancement of osteogenic potential of biphasic calcium phosphate (BCP) bone substitute coated with Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2) and epigallocatechin-3-gallate (EGCG). Methods: The cell viability, differentiation, and mineralization of osteoblasts was tested with ErhBMP-2-/EGCG solution. Coated BCP surfaces were also investigated. Standardized, 6-mm diameter defects were created bilaterally on the maxillary sinus of 10 male New Zealand white rabbits. After removal of the bony windows and elevation of sinus membranes, ErhBMP-2-/EGCG-coated BCP was applied on one defect in the test group. BCP was applied on the other defect to form the control group. The animals were sacrificed at 4 or 8 weeks after surgery. Histologic and histometric analyses of the augmented graft and surrounding tissue were performed. Results: The 4-week and 8-week test groups showed more new bone (%) than the corresponding control groups (P<0.05). The 8-week test group showed more new bone (%) than the 4-week test group (P<0.05). Conclusions: ErhBMP-2-/EGCG-coated BCP was effective as a bone graft material, showing enhanced osteogenic potential and minimal side effects in a rabbit sinus augmentation model.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.2
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• pp.93-100
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• 2010

The calcium to phosphate ratio (Ca/P) in biphasic calcium phosphates powders using X-ray diffraction analysis (XRD) was characterized. The BCP powders with various stoichiometric Ca/P molar ratio were synthesized with coprecipitation process and calcination. Compositions of the powders with Ca/P molar ratio between 1.5 and 1.67 were subjected to starting Ca/P molar ratio, pH = 10, and thermal treatment up to $900^{\circ}C$. The structural, morphological and chemical characterizations for BCP powders with stoichiometric Ca/P ratio were carried out with scanning electron microscope (SEM) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) and a phase quantification was investigated by XRD. The solubility of HAp, $\beta$-TCP, and BCP powders was tested in the phosphate buffer solution (PBS) at $36.5^{\circ}C$ and pH = 7.4.

• Journal of Biomedical Engineering Research
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• v.25 no.2
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• pp.119-127
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• 2004

In this paper, an automatic external biphasic defibrillator that removes ventricular fibrillation efficiently with a low discharging energy has been developed. The system is composed of software including a fibrillation detection algorithm and a system control algorithm, and hardware including a high voltage charging/discharging part and a signal processing part. The stability of the developed system has been confirmed through continuous charging/discharging test of 160 times and the detection capability of the real-time fibrillation detection algorithm has been estimated by applying a total of 30 various fibrillation signals. In order to verify the clinical efficiency and safety, the system has been applied to five pigs before and after fibrillation inductions. Also, we have investigated the system efficiency in removing fibrillation by applying two different discharging waveforms, which have the same energy but different voltage levels.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.2
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• pp.92-98
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• 2012

The co-precipitation technique has been applied to synthesize biphasic calcium phosphate (BCP). $Ca(NO_3)_2{\cdot}4H_2O$, $(NH_4)_2HPO_4$, TEOS and $Mg(NO_3)_2{\cdot}6H_2O$ as the starting materials was used. After the heat treatment of powder crystalline phases HAp and ${\beta}$-TCP analysis showed a mixed phase. The overall spectra appear to have mainly two modes corresponding to characteristic $PO^{3-}_4$ and $OH^-$ groups. After immersion in Hanks' Balanced Salt Solution (HBSS) for 1 week a precipitation started to be formed with individual small granules on the specimen surface. An MTT assay indicated that ionic substituted BCP powders had no cytotoxic effects on MG-63 cells, and that they have good biocompatibility.