• 대한약침학회지
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• 제25권4호
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• pp.396-403
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• 2022

Objectives: Gout is an inflammatory arthritis of the joints and soft tissues occurring due to deposition of monosodium urate (MSU) crystals, which are caused by persistent hyperuricemia. Soyeom pharmacopuncture is one treatment method that has been traditionally used for pain management in Oriental medicine. However, studies on its effect in reducing gout pain have been insufficient. Therefore, we selected Soyeom pharmacopuncture among natural products used in Korea as the new target of our study. Methods: The effects of Soyeom pharmacopuncture were examined in mouse models of acute gout induced by injection of MSU crystals into footpads. IL-1β, IL-6, and TNF-α production were examined by immunoblotting and enzyme-linked immunosorbent assay as hallmarks of NLRP3 inflammasome and cytokine activation. Results: Soyeom pharmacopuncture reduced foot edema in gout-induced mice, as well as IL-1β, nitrite, IL-6, and TNF-α production. Moreover, Soyeom pharmacopuncture also reduced MSU-induced gout inflammatory gene expressions, specifically those in the NF-kB pathway. Conclusion: Pharmacopuncture may serve as a new solution for other inflammatory diseases as well. Through active follow-up studies, we could thoroughly understand the clinical value of Soyeom pharmacopuncture.

• 한국결정성장학회지
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• 제20권3호
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• pp.107-112
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• 2010

높은 광흡수 계수를$(1{\times}10^5cm^{-1})$ 가지는 CIGS는 Ga의 비율에 따라서 밴드갭을 조절할 수 있다는 장점을 지니고 있다. CIGS의 밴드갭은 Ga의 비율에 따라 $CuInSe_2$(Eg: 1.0 eV)에서 $CuGaSe_2$(Eg: 1.68 eV)까지의 범위에 존재하며, 태양전지에 서 이상적인 fill factor 모양을 가지도록 Ga의 비율을 높게 조성한다. CIGS 흡수층을 제작하는 방법에는 co-evaporator 방식이 가장 널리 사용되며 연구되고 있다. 이에 본 연구에서는 수평 형태의 hydride vapor transport (HVT)법을 고안하여 CIGS 나노 구조 및 에피성장을 시도하였다. HVT법은 $N_2$ 분위기에서 원료부의 CIGS 혼합물을 HCl과 반응시켜 염화물 기체상태로 변환 후 growth zone까지 이동하여 성장을 하는 방식이다. 성장기판은 c-$Al_2O_3$ 기판과 u-GaN을 사용하였다. 성장 후 field emission scanning electron microscopy(FE-SEM)과 energy dispersive spectrometer(EDS)를 이용하여 관찰하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.417-417
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• 2016

Global environmental deterioration has become more serious year by year and thus scientific interests in the renewable energy as environmental technology and replacement of fossil fuels have grown exponentially. Photoelectrochemical (PEC) cell consisting of semiconductor photoelectrodes that can harvest light and use this energy directly to split water, also known as photoelectrolysis or solar water splitting, is a promising renewable energy technology to produce hydrogen for uses in the future hydrogen economy. A major advantage of PEC systems is that they involve relatively simple processes steps as compared to many other H2 production systems. Until now, a number of materials including TiO2, WO3, Fe2O3, and BiVO4 were exploited as the photoelectrode. However, the PEC performance of these single absorber materials is limited due to their large charge recombinations in bulk, interface and surface, leading low charge separation/transport efficiencies. Recently, coupling of two materials, e.g., BiVO4/WO3, Fe2O3/WO3 and CuWO4/WO3, to form a type II heterojunction has been demonstrated to be a viable means to improve the PEC performance by enhancing the charge separation and transport efficiencies. In this study, we have prepared a triple-layer heterojunction BiVO4/WO3/SnO2 photoelectrode that shows a comparable PEC performance with previously reported best-performing nanostructured BiVO4/WO3 heterojunction photoelectrode via a facile solution method. Interestingly, we found that the incorporation of SnO2 nanoparticles layer in between WO3 and FTO largely promotes electron transport and thus minimizes interfacial recombination. The impact of the SnO2 interfacial layer was investigated in detail by TEM, hall measurement and electrochemical impedance spectroscopy (EIS) techniques. In addition, our planar-structured triple-layer photoelectrode shows a relatively high transmittance due to its low thickness (~300 nm), which benefits to couple with a solar cell to form a tandem PEC device. The overall PEC performance, especially the photocurrent onset potential (Vonset), were further improved by a reactive-ion etching (RIE) surface etching and electrocatalyst (CoOx) deposition.

• Journal of Chest Surgery
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• 제31권6호
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• pp.560-566
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• 1998

서론: 심혈관계 수술 시 이용되는 조직판막 등 glutaraldehyde(GA)에 보존한 이종보철편들은 석회화에 의한 변성으로 환자의 장기성적에 나쁜 영향을 주게 된다. 이에 연구자는 GA 용액에 Mg 염을 첨가, 자유 알데히드와 미리 결합하게 함으로 조직 및 혈중의 칼슘과 반응하는 것을 막아 석회화를 완화하고자 시도하였고 계면활성제로 sodium dodecyl sulfate(SDS)와 Triton X-100을 사용, 전처치하여 GA에 고정, 석회화 완화 효과를 관찰하였다. 대상 및 방법: 우심낭을 정방형 조각으로 만들어 40 조각의 우심낭편은 대조군으로 MgCl2.6H2O를 4g/L 첨가한 0.625% GA 용액에 보존하고(1 군), 40 조각은 SDS에 전처치 후 이 GA 용액에 보존(2 군), 또 다른 40 조각은 Triton X-100에 전처치 후 GA에(3 군) 각각 한달 간 보관한다. 이들을 40 마리의 백서의 복부 피하에 각각 한 조각씩 이식하여 1 개월, 2 개월, 3 개월 및 6 개월 째에 적출, spectrophotometry로 이 우심낭편에 침착한 칼슘을 정량분석하였다. 결과: 이식 후 1 개월에는 세 군 간의 석회화 정도에 차이가 없었으나, 2 개월 부터 차이를 보여 1 군 0.921$\pm$0.121 mg/g, 2 군 0.481$\pm$0.037 mg/g, 3 군 1.369$\pm$0.200 mg/g의 통계적 차이를 보였고(p<0.05), 3 개월에 1 군 0.786$\pm$0.080 mg/g, 2 군 0.584$\pm$0.054 mg/g, 3 군 1.139$\pm$0.188 mg/g, 마지막 6 개월에 1 군 1.623$\pm$0.601 mg/g, 2 군 0.501$\pm$0.043 mg/g, 3 군 1.625$\pm$0.382 mg/g으로 정량되어 2 군에서 유의한 석회화 완화 효과가 관찰되고 있다 (p<0.05). 결론: 음성 계면활성제인 SDS의 전처치로 중기 이상 시간이 경과함에 따라 피하에 이식된 보철편의 석회화가 완화되었으나 중성 계면활성제인 Triton X-100의 전처치로는 완화 효과가 관찰되지 않았다.

• 공업화학
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• 제21권4호
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• pp.435-439
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• 2010

Pt-$MoO_3$ 혼합전극을 20 mM의 $H_2PtCl_6$ 수용액과 10 mM Mo-Peroxo 전해질을 이용하여 전기화학적 증착법에 의해 합성하였다. Pt와 증착 순서를 바꿔가며 혼합 전극을 합성하여 같은 양의 Pt가 증착된 순수한 Pt전극과 메탄올 산화반응 특성을 비교하였다. SEM (Scanning Electron Microscopy) 분석을 통하여 합성된 박막의 표면입자의 형태를 확인하였으며, X-선 회절(X-ray Diffraction)분석과 광전자 분광기(X-ray Photoelectron Spectroscopy; Thermo-scientific, ESCA 2000)분석을 통해 합성된 전극의 결정성과 산화가를 각각 조사하였다. 메탄올 산화에 대한 전기화학적 촉매활성과 안정성을 평가한 결과 Pt를 증착한 후 $MoO_3$를 증착한 전극의 경우, 순수한 Pt전극에 비해 높은 촉매활성과 안정성을 나타내었는데, Pt와 $MoO_3$의 접촉이 좋을 경우 $MoO_3$가 조촉매로 작용해 메탄올 산화반응의 활성이 증가함을 확인하였다.

• 대한소아치과학회지
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• 제24권1호
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• pp.148-172
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• 1997

Sixty human premolar teeth were used for this in vitro study. After each tooth was sectioned mesiodistally, one half was used for the experimental group and the other half for the control. Three groups were made for each fluoride applying method and twenthy teeth were assigned to each group. Ten teeth were used for evaluating total fluoride amount and the other ten were used for firmly-bound fluoride. Fluorshield was used for fluoride-releasing sealant and 1.23% APF, 0.05% NaF were used for topical application fluorides. Each tooth was cleaned with a tooth brush using nonfluoride containing pumice before the experiment. In the sealant group, fluoroshield was applied to the enamel surface without etching procedure and stored in $37^{\circ}C$ saline for 30 days. After 30 days, sealant was removed with explorer without scratching the enamel surface and washed with distilled water and dried. In the APF group, each tooth was immersed in 1.23% APF for 30 min then washed and dried in the same manner. In the NaF group, each tooth was immersed in 0.05% NaF for 24 hours then washed and dried as described above. After each fluoride regimen was applied, ten teeth were randomly selected from each group and immersed in 1M KOH solution for 24 hours to remove loosely-bound fluoride possibly deposited by the three different fluorides applied. In each group, total fluoride amount deposited and the amount of enamel removed by acid biopsy were calculated. After loosely-bound fluoride was removed, firmly-bound fluoride deposited and the amount of enamel removed by acid biopsy were also calculated. Total fluoride amount deposition was significantly increased in the APF and NaF groups, but not in the sealant group. Amount of enamel removed by acid-biopsy was also significantly diminished in the APF and NaF groups, but not in the sealant groups. After loosely-bound fluoride was removed from each groups, no statistical difference was found in the amount of firmly-bound fluoride in any groups. Also no effect of firmly-bound fluoride on enamel dissolution was shown in any groups after loosely-bound fluoride was removed from each group. In conclusion, topical application method of APF or NaF is more effective than fluoride-releasing sealant application to make $CaF_2$ coating on enamel surface and $CaF_2$ coating is the main source for anticariogenic effect of fluoride. However, longterm anticariogenic effect of fluoride-releasing sealant should be further evaluated.

• 한국결정성장학회지
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• 제19권6호
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• pp.305-310
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• 2009

PMMA 입자의 표면에 양전하를 갖는 전해질 폴리머 PDDA와 음전하를 갖는TALH를 사용하여 $TiO_2$ 박막을 LBL 법에 의해 성공적으로 제조하였다. 수정진동자의 측정을 통해 TALH의 용액의 pH가 감소됨에 따라 TALH의 적층량이 늘어나고 PMMA의 입자 표면에 코팅된 (PDDA/TALH) 박막의 두께가 증가됨을 확인하였다. (PDDA/TALH)n의 순서에 의해 코팅된 PMMA 입자들은 bilayer 수의 변화에 따라 다양한 색 변화를 보여주었다. (PDDA/TALH) 박막의 bilayer 수(n)가 10과 20 일 경우에 $a^*$와 $b^*$의 값은 막이 코팅되지 않은 PMMA의 값보다 감소하였고 색 변화는 $a^*$, $b^*$ 색도도에서 각각 green과 blue 방향으로 이동하였다. 이후 n의 수가 30, 40으로 증가됨에 따라 $a^*$와 $b^*$의 값은 증가하였고 색의 변화는 red와 yellow 방향으로 각각 이동하였다. 최종적으로 $(PDDA/TALH)_{50}$ 박막이 코팅된 PMMA 입자들은 박막이 코팅되지 않은 PMMA 입자들과 거의 비슷한 $a^*$와 $b^*$의 값을 보여주었다.

• 한국진공학회지
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• 제19권2호
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• pp.81-90
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• 2010

층과 층 사이의 정전기적인력, 수소결합 또는 공유결합을 이용하여 층당 두께를 수 옹스트롱에서부터 수십 나노미터까지 제조할 수 있으며 박막의 표면 형태를 흡착시키고자 하는 물질 및 박막 후처리 공정을 통해 제어할 수 있으며 더 나아가, 삽입하는 물질의 특성에 따라 박막의 기능성을 집적화 및 다양화시킬 수 있다. 본 연구에서는 이러한 층상자기조립방법의 특성을 이용하여 반사방지막, 초소수성 필름 및 전기화학센서로의 응용가능성을 제시하였다. 반사방지막의 경우, 구형의 블록공중합체를 유리기판 위에 다층박막으로 적층시킴으로써 박막 굴절률을 1.25까지 감소시켰고 이를 통해 약 99.5%의 빛 투과도를 달성할 수 있었다. 더 나아가 바이오물질인 엔자임을 다층박막에 삽입시킬 경우, 활성 산소를 분해시키는 전기화학센서로의 제조가 가능함을 보인다. 본 연구는 본인이 이미 발표한 논문(J. Am. Chem. Soc. 128, 9935 (2006); Adv. Mater. 19, 4364 (2007); Electro. Mater. Lett. 3, 163 (2007))들을 정리하여 층상자기조립법에 관해 소개하는 논문이다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.197-197
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• 2016

Commercially pure titanium (CP Ti) and Ti-6Al-4V alloys have been widely used for biomedical applications. However, the use of the Ti-6Al-4V alloy in biomaterial is then a subject of controversy because aluminum ions and vanadium oxide have potential detrimental influence on the human body due to vanadium and aluminum. Hence, recent works showed that the synthesis of new Ti-based alloys for implant application involves more biocompatible metallic alloying element, such as, Nb, Hf, Zr and Mo. In particular, Nb and Hf are one of the most effective Ti ${\beta}-stabilizer$ and reducing the elastic modulus. Plasma electrolyte oxidation (PEO) is known as excellent method in the biocompatibility of biomaterial due to quickly coating time and controlled coating condition. The anodized oxide layer and diameter modulation of Ti alloys can be obtained function of improvement of cell adhesion. Manganese(Mn) plays very important roles in essential for normal growth and metabolism of skeletal tissue in vertebrates and can be detected as minor constituents in teeth and bone. Radio frequency(RF) magnetron sputtering in the various PVD methods has high deposition rates, high-purity films, extremely high adhesion of films, and excellent uniform layers for depositing a wide range of materials, including metals, alloys and ceramics like a hydroxyapatite. The aim of this study is to research the Mn coatings on the micro-pore formed Ti-29Nb-xHf alloys by RF-magnetron sputtering for dental applications. Ti-29Nb-xHf (x= 0, 3, 7 and 15wt%, mass fraction) alloys were prepared Ti-29Nb-xHf alloys of containing Hf up from 0 wt% to 15 wt% were melted by using a vacuum furnace. Ti-29Nb-xHf alloys were homogenized for 2 hr at $1050^{\circ}C$. Each alloy was anodized in solution containing typically 0.15 M calcium acetate monohydrate + 0.02 M calcium glycerophosphate at room temperature. A direct current power source was used for the process of anodization. Anodized alloys was prepared using 270V~300V anodization voltage at room. Mn coatings was produced by RF-magnetron sputtering system. RF power of 100W was applied to the target for 1h at room temperature. The microstructure, phase and composition of Mn coated oxide surface of Ti-29Nb-xHf alloys were examined by FE-SEM, EDS, and XRD.

• 한국재료학회지
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• 제20권11호
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• pp.586-591
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• 2010

Solar cells have been more intensely studied as part of the effort to find alternatives to fossil fuels as power sources. The progression of the first two generations of solar cells has seen a sacrifice of higher efficiency for more economic use of materials. The use of a single junction makes both these types of cells lose power in two major ways: by the non-absorption of incident light of energy below the band gap; and by the dissipation by heat loss of light energy in excess of the band gap. Therefore, multi junction solar cells have been proposed as a solution to this problem. However, the $1^{st}$ and $2^{nd}$ generation solar cells have efficiency limits because a photon makes just one electron-hole pair. Fabrication of all-silicon tandem cells using an Si quantum dot superlattice structure (QD SLS) is one possible suggestion. In this study, an $SiO_x$ matrix system was investigated and analyzed for potential use as an all-silicon multi-junction solar cell. Si quantum dots with a super lattice structure (Si QD SLS) were prepared by alternating deposition of Si rich oxide (SRO; $SiO_x$ (x = 0.8, 1.12)) and $SiO_2$ layers using RF magnetron co-sputtering and subsequent annealing at temperatures between 800 and $1,100^{\circ}C$ under nitrogen ambient. Annealing temperatures and times affected the formation of Si QDs in the SRO film. Fourier transform infrared spectroscopy (FTIR) spectra and x-ray photoelectron spectroscopy (XPS) revealed that nanocrystalline Si QDs started to precipitate after annealing at $1,100^{\circ}C$ for one hour. Transmission electron microscopy (TEM) images clearly showed SRO/$SiO_2$ SLS and Si QDs formation in each 4, 6, and 8 nm SRO layer after annealing at $1,100^{\circ}C$ for two hours. The systematic investigation of precipitation behavior of Si QDs in $SiO_2$ matrices is presented.