• Restorative Dentistry and Endodontics
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• 제33권2호
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• pp.98-106
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• 2008

본 연구에서는 근관 세척법이 두 가지 근관 충전재 (Gutta-percha/AH 26 sealer, Resilon/Epiphany sealer)의 근관 상아질과의 접착에 미치는 영향을 평가하였다. 총 30개의 발거된 상악 전치를 각각 5개씩 6개의 군으로 분류하여 근관 성형을 하고 마지막 세척을 다음과 같이 시행한 후 G1, G2, G3 군은 Gutta-percha/AH 26 sealer로, R1, R2, R3 군은 Resilon/Epiphany sealer로 근관 충전하였다. G1, R1군 : 5.25% NaOCl 세척 G2, R2군 : 5.25% NaOCl 세척 후 sterile saline세척 G3, R3군 : 5.25% NaOCl 세척 후 17% EDTA, sterile saline 순으로 세척 각 군의 충전된 치아를 아크릴 레진에 매몰하고 약 1 mm두께로 절단한 후 만능 물성 시험기상에서 push-out bond strength를 측정하였고 실험 후 파절 양상을 Image-analyzing microscope으로 관찰하여 다음과 같은 결과를 얻었다. 1. Gutta-percha/AH 26 sealer 충전군에서 Resilon/Epiphany sealer 충전군보다 push-out bond strength가 높게 나타났다 (p < 0.05). 2. Resilon/Epiphany sealer 충전군 중 17% EDTA, sterile saline순으로 세척시 5.25% NaOCl 세척에 비해 push-out bond strength가 높게 나타났다 (p < 0.05). 3. 파절 양상을 분석시 모든 군은 접착성과 혼합성 파절 양상을 나타내었고, G1, G2, R1 군은 응집성 파절 양상이 나타나지 않았으며, Resilon/Epiphany sealer 충전군은 Gutta-percha/AH 26 sealer 충전군에 비해 응집성과 혼합성 파절 양상이 더 높은 비율로 나타났다.

• Restorative Dentistry and Endodontics
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• 제45권1호
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• pp.2.1-2.7
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• 2020

Objectives: This study aimed to evaluate the cell viability and migration of Endosequence Bioceramic Root Canal Sealer (BC Sealer) compared to MTA Fillapex and AH Plus. Materials and Methods: BC Sealer, MTA Fillapex, and AH Plus were placed in contact with culture medium to obtain sealers extracts in dilution 1:1, 1:2 and 1:4. 3T3 cells were plated and exposed to the extracts. Cell viability and migration were assessed by 3-(4,5-dimethylthiazoyl)-2,5-diphenyl-tetrazolium bromide (MTT) and Scratch assay, respectively. Data were analyzed by Kruskal-Wallis and Dunn's test (p < 0.05). Results: The MTT assay revealed greater cytotoxicity for AH Plus and MTA Fillapex at 1:1 dilution when compared to control (p < 0.05). At 1:2 and 1:4 dilutions, all sealers were similar to control (p > 0.05) and MTA Fillapex was more cytotoxic than BC Sealer (p < 0.05). Scratch assay demonstrated the continuous closure of the wound according to time. At 30 hours, the control group presented closure of the wound (p < 0.05). At 36 hours, only BC Sealer presented the closure when compared to AH Plus and MTA Fillapex (p < 0.05). At 42 hours, AH Plus and MTA Fillapex showed a wound healing (p > 0.05). Conclusions: All tested sealers demonstrated cell viability highlighting BC Sealer, which showed increased cell migration capacity suggesting that this sealer may achieve better tissue repair when compared to other tested sealers.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2022년도 추계학술대회
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• pp.254-257
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• 2022

현재는 온라인을 통해 개인이 직접 방송을 제작하는 형태의 1인 방송이 가능한 시대이다. 스마트폰을 이용하였을 경우 방송할 만한 충분한 환경이 마련되지 않아도 비교적 간단하게 중계 시스템을 구성할 수 있다. 본 논문에서는 최근 하나의 문화이자 대중 스포츠로 자리 잡은 E-스포츠의 게임 유저들이 스마트폰을 활용해 게임에 쉽게 참여할 수 있는 중계 시스템 구현을 제안한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.359-362
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• 2000

The purpose of this study is to research and develop graphene composite for lithium polymer battery. VO(graphene) composite is one of the promising material as a electrode active material for lithium polymer battery(LPB). We investigated AC impedance response and charge/discharge cycling of VO(graphene)/SPE/Li cells. The first discharge capacity of VO(graphene) cathode with 50wt.% V$_2$O$\sub$5/ was 150mAh/g, while that of VO(graphene) cathode with 85wt.% V$_2$O$\sub$5/ was 248mAh/g. The Ah efficiency was above 98% after the 2nd cycle. The discharge capacity of VO(graphene) anode with 3wt.% V$_2$O$\sub$5/ was 718 and 266mAh/g at cycle 1 and 10 at room temperature, respectively. The VO(graphene) anode with 3wt.% V$_2$O$\sub$5/ in PVDF-PAN-PC-EC-LiC1O$_4$ electrolyte showed good capacity with cycling.

• 한국미생물·생명공학회지
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• 제47권1호
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• pp.116-124
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• 2019

The rapid development of the poultry industry has led to the production of large amounts of manure, which produce substances like hydrogen sulfide ($H_2S$) that contribute to odor pollution. $H_2S$ is a highly undesirable gas component and its removal from the environment is therefore necessary. Sulfur-oxidizing bacteria (SOB) are widely known to remove contaminating $H_2S$ due to their ability to oxidize reduced sulfur compounds. In this study, three potential SOB (designated AH18, AH25, and AH28) that were previously isolated from a hot spring in Malaysia were identified by 16S rRNA gene analysis. Laboratory-scale biological deodorization experiments were conducted to test the performance of the three isolates-in the form of pure or mixed cultures, with the cells immobilized onto alginate as a carrier-in reducing the $H_2S$ from chicken manure. On the basis of 16S rRNA phylogenetic analysis, isolate AH18 was identified as Pseudomonas sp., whereas isolates AH25 and AH28 were identified as Achromobacter sp. The most active deodorizing isolate was AH18, with an $H_2S$ reduction rate of 74.7% (p < 0.05). Meanwhile, the reduction rates for isolates AH25 and AH28 were 54.2% and 60.8% (p > 0.05), respectively. However, the $H_2S$ removal performance was enhanced in the mixed culture, with a reduction rate of 81.9% (p < 0.05). In conclusion, the three potential SOB isolates were capable of reducing the $H_2S$ from chicken manure in the form of a pure culture immobilized on alginate, and the reduction performance was enhanced in the mixed culture.

• Molecules and Cells
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• 제41권4호
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• pp.290-300
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• 2018

Using an in vitro model of intestinal organoids derived from intestinal crypts, we examined effects of indole-3-carbinol (I3C), a phytochemical that has anticancer and aryl hydrocarbon receptor (AhR)-activating abilities and thus is sold as a dietary supplement, on the development of intestinal organoids and investigated the underlying mechanisms. I3C inhibited the in vitro development of mouse intestinal organoids. Addition of ${\alpha}$-naphthoflavone, an AhR antagonist or AhR siRNA transfection, suppressed I3C function, suggesting that I3C-mediated interference with organoid development is AhR-dependent. I3C increased the expression of Muc2 and lysozyme, lineage-specific genes for goblet cells and Paneth cells, respectively, but inhibits the expression of IAP, a marker gene for enterocytes. In the intestines of mice treated with I3C, the number of goblet cells was reduced, but the number of Paneth cells and the depth and length of crypts and villi were not changed. I3C increased the level of active nonphosphorylated ${\beta}$-catenin, but suppressed the Notch signal. As a result, expression of Hes1, a Notch target gene and a transcriptional repressor that plays a key role in enterocyte differentiation, was reduced, whereas expression of Math1, involved in the differentiation of secretory lineages, was increased. These results provide direct evidence for the role of AhR in the regulation of the development of intestinal stem cells and indicate that such regulation is likely mediated by regulation of Wnt and Notch signals.

• 한국균학회지
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• 제16권3호
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• pp.121-127
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• 1988

흰느타리버섯(Pleurotus cornucopiae(Per.) Rolland)중의 단백질을 선택적으로 분리정제하기 위하여 AH-Sepharose 4B를 출발 물질로 하여 benzoyl-AH-Sepharose 4B를 합성하여 친화성 크로마토그래피하였다. 1) AH-Sepharose 4B 중의 amino기의 capacity는 겔 Iml 당 $9.5{\mu}mol$ 이었으며 합성겔의 리간드인 benzoyl기의 capacity는 겔 1ml당 $9.3{\mu}mol4이었다. 2) 친화성이 있는 단백질의 총 겉보기 분자량은 255,000 돌톤 이었으며, 이는 29,500, 31,500, 34,000, 71,000 및 89,000돌톤 단백질의 복합체였다. 3) 친화성 단백질 중의 아미노산 함량은 비극성 아미노산이 45.68%, 극성 아미노산이 26.93%, 양성 아미노산이 11.81%, 그리고 음성 아미노산이15.58%였다. 4) 소수성 benzoyl기에 친화성이 있는 단백질은 비극성인 것이 선택적으로 분리되었다.

• 전기화학회지
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• 제5권1호
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• pp.30-38
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• 2002

탄화수소가스를 고온$(1000^{\circ}C)$에서 열분해 하여 고상화하는 기상 열분해법을 사용하여 저결정질 탄소재를 제조하고 같은 방법으로 붕소를 첨가한 저결정질 탄소재$C_{l-x}B_x(x=0.05,\;0.10,\;0.20)$를 제조하여, 리튬 이온 이차전지의 부극으로서의 전기화학적 특성을 조사하였다. 시료 대 PVDF를 95:5의 무게비로 첨가한 경우, 붕소를 첨가하지 않은 저 결정질 탄소재(x=0.00)는 초기 방전용량 374mAh/g을 나타내었으며, 제 2싸이클부터는 싸이클 성능이 비교적 우수하여 제 10싸이클에서 258mAh/g의 방전용량을 나타내었다. 시료 대 PVDF를 95:5의 무게비로 첨가한 경우, $C_{1-x}B_x(x=0.00,\;0.05,\;0.10\;0.20)$ 시료들 중에서 x=0.05 조성의 시료는 가장 큰 초기 방전용량 860mAh/g을 나타내었으며, 10번째 싸이클에서 181mAh/g의 방전용량을 나타내었다. 제 2싸이클부터 싸이클 성능은 모두가 비슷하게 나타났다 초기방전 용량(PVDF $10wt.\%$ 사용시, 853mAh/g), 싸이클 성능, 방전용량(PVDF $10wt.\%$사용시 10번째 싸이클에서 400mAh/g)면에서 $C_{0.90}B_{0.10}$ 시료가 리튬이온 이차전지의 부극으로서의 가장 우수한 전기화학적 특성을 나타내었다. 합성한 탄소에 NMP를 용매로 한 액상 혼합 바인더(PVDF)를 90:10의 무게비로 첨가한 경우가 95:5의 무게비로 첨가한 경우보다 대체로 모든 조성에서 충$\cdot$방전용량이 크게 나타났다. 붕소가 첨가되어 덜 disordered된 구조가 됨으로써 1.25V보다 낮은 전압 부분에서 평탄구역이 증가하는 것으로 판단된다. 붕소가 첨가된 경우 충$\cdot$방전용량이 제 2싸이클에서부터 급격히 감소하였는데, 이는 첨가된 붕소가 제 1싸이클에서 삽입되는 Li과 일부는 강하게 결합하여 추출이 안되고 일부만이 다시 가역적으로 추출$\cdot$삽입되기 때문으로 생각된다. 붕소 첨가에 의한 충$\cdot$방전용량의 증가는, 붕소가 electron acceptor로 작용하여 삽입된 Li와 붕소-탄소 host 사이의 결합 강도를 증가시킴으로써 붕소치환 된 탄소에서 Li의 전위를 상승시키기 때문에 일어난다고 사려된다.

• Journal of Electrochemical Science and Technology
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• 제14권2호
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• pp.139-144
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• 2023

In this study, carbon-coated porous nanofibers were prepared via electrospinning and the performance of Li[Ni_0.93Co_0.07]O₂ (NC) synthesized by electrospinning (E-NC) and co-precipitation (C-NC) was compared. E-NC had a discharge capacity of 206 mAh g^-1 at 0.1C (17 mA/g), which is 10% higher than that of C-NC (189.2 mAh g^-1). E-NC shows a high-rate performance of 118.32 mAh g^-1 (61.7%) at 5C (850 mA/g), which is 50% higher than that of C-NC (78.22 mAh g^-1 = 45.7%). Charge transfer of the carbon-coated porous nanofiber E-NC decreased by 35% compared to C-NC after 20 cycles as observed using electrochemical impedance spectroscopy. The results of this study show that the nanofiber structure with carbon coating shortens the Li-ion diffusion path, improves electrical conductivity, resulting in excellent rate performance.

• Bulletin of the Korean Chemical Society
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• 제22권12호
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• pp.1328-1332
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• 2001

The structure and electrochemical properties of the LixCoyNi1-yO2 (y=0.1, 0.3, 0.5, 0.7, 1.0) system synthesized by solid state reaction with various starting materials have been investigated to optimize the characteristics and synthetic conditions of the LixCoyNi1-yO2. The first discharge capacities of LixCoyNi1-yO2 are 60 mAh/g-180 mAh/g with synthetic conditions. Among them, the LixNi0.7Co0.3O2, which was prepared with LiOH, NiO, and Co3O4 at $850^{\circ}C$, had the best electrochemical properties. The first discharge capacity of the compound was 180 mAh/g.