Solvothermal Synthesis of Ferroelectric BaTiO3 Nanoparticles and Their Application to Dye-sensitized Solar Cells

Ming Hao Jin,Eunhye Shin,Saera Jin,Hongil Jo,Kang Min Ok,Jongin Hong,Byung-Hyuk Jun,James R. Durrant 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.73 No.5

Cubic BaTiO3 (C-BT) and tetragonal BaTiO3 (T1-BT) nanoparticles were prepared by a solvothermal method with controlling the Ba/Ti precursor ratio. Triethanolamine was additionally employed in the synthesis to obtain ferroelectric BaTiO3 with improved particle size distribution and tetragonality (T2-BT). The prepared nanoparticles were thoroughly characterized by scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller analysis, X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, photoluminescence, and second-harmonic generation. Importantly, the BaTiO3 nanoparticles were introduced into the scattering layer of dye-sensitized solar cells and T2-BT showed better power conversion eciency than C-BT and T1-BT.

B형 간염 바이러스에 의한 비대상성 간경변증 환자에서 라미부딘의 치료 효과

정세라,서동진,박현주,박영환,송희곤,이한주,정영화,이영상 대한간학회 2002 Clinical and Molecular Hepatology(대한간학회지) Vol.8 No.4

목적: 최근 라미부딘이 B형 간염 바이러스와 연관된 비대상성 간경변증 환자에서도 효과적이라고 보고되었으나, 대부분의 경우에서 간이식을 병용하였거나 6개월 이상 치료한 환자만을 대상으로 하였다는 문제점이 있다. 이번 연구에서는 이러한 문제점을 극복하기 위하여 라미부딘 치료를 받은 비대상성 간경변증 환자를 순차적으로 포함, 분석함으로써 그 효과를 알아보고자 하였다. 대상과 방법: 라미부딘 치료에 동의한 HBV DNA 양성인 비대상성 간경변증 환자 24예를 순차적으로 분석하였다. 21예는 HBeAg 양성이었으며, 투여기간은 2-51개월(중간값 16개월) 이었다. 8예는 Child- Pugh 등급 B였고, 16예는 등급 C였다. 라미부딘 투여 후 Child-Pugh 점수가 2점 이상 감소한 경우를 임상적 호전으로 정의하였다. 결과: 라미부딘 투여 6개월 시점에는 100%의 환자에서 HBV DNA의 음전을 보였고, 누적 HBeAg 소실률은 치료 6개월 시점에 28.6%, 1년 시점에 46.7%였다. 관 찰 기간 중 누적 breakthrough 발생률은 1년 20%, 2년 시점에 37.5%였다. 투여 전과 비교하여 6개월 시점에 Child-Pugh 점수가 2점 이상 호전된 경우 는 60.9%였고, 변화가 없었던 경우는 34.8%, 악화 된 경우가 4.3%였으며, 마지막 방문 시에 호전된 경우는 56.5%였다. 호전된 환자들은 2예를 제외하고 는 치료 6개월 내에 호전을 보였다. 누적 사망률은 1년 20.8%, 2년 시점에 37.5%였다. 결론: B형 간염 바이러스에 의한 비대상성 간경변증 환자의 약 60%에서 라미부딘 투여로 간기능이 호전되었다. 대부분의 호전은 투여 6개월 이내에 나타나므로 라미부딘 투여 6개월 내에 임상적 호전을 보이지 않는 비대상성 간경변증 환자에서는 보다 적극적으로 간이식을 고려해야 할 것이다. Background/Aims: Although several clinical trials have suggested that lamivudine treatment can be very effective in patients with decompensated HBV-associated cirrhosis, its role and clinical efficacy are still uncertain because of the study designs. The aim of this study is to evaluate the efficacy of lamivudine in consecutively enrolled patients with decompensated cirrhosis. Methods: Twenty-four patients with decompensated HBV-associated cirrhosis (Child-Pugh score ≥8) were enrolled consecutively and treated with lamivudine 100 mg or 150 mg daily for 2-51 months (median: 16 months). They were all positive for HBV DNA and 21 were positive for serum HBeAg. Eight were Child-Pugh class B and 16 were class C. Clinical improvement was defined as a decrease of Child-Pugh score of at least 2 points. Results: At 6th month after lamivudine, all the patients cleared serum HBV DNA. The cumulative rates for HBeAg loss were 28.6% at 6th and 46.6% at 12th month. The cumulative viral breakthrough rates at 12th and 24th month were 20.0% and 37.5%. Fourteen patients (60.8%) showed clinical improvement, while 8 (34.8%) showed no change and 1 got worse, at 6th month after lamivudine. Most clinical improvement developed within the initial 6 months. The cumulative mortality rates were 20.8% at 1 year and 37.5% at 2 year. Conclusions: These data suggest that lamivudine can result in clinical improvement in about 60% of patients with HBV-related decompensated cirrhosis. Because most improvement occurrs within 6 months after starting lamivudine, liver transplantation should be actively considered in cases which do not show clinical improvement despite 6-month lamivudine treatment.(Korean J Hepatol 2002;8:418-427)

Pre-Stabilization of Zr Getters for 5-Nine Purity Nitrogen Gas Purification

Kim, Kwangbae,Jin, Saera,Lim, Yesol,Lee, Hyunjun,Kim, Seonghoon,Noh, Yunyoung,Song, Ohsung Materials Research Society of Korea 2021 한국재료학회지 Vol.31 No.4

We confirm whether Zr powders can restrain a rapid nitrification reaction and offer a stable oxidation reaction according to temperatures in nitrogen gas purification. A pellet-type, porous Zr getter is prepared (diameter: 10 and thickness: 3 mm) using Zr powder with an average particle size of 45 ㎛. While maintaining the whole system, the Zr getter reaction is confirmed with an increase in temperature from 150 to 550 ℃ at increments of 100 ℃ under 99.999 % purity nitrogen atmosphere comprising of 10 ppm of impurity. Surface color, pore size, stabilized layer, and phase change are confirmed with optical microscopy, SEM-EDS, Micro-Raman, and X-ray diffraction (XRD) according to the Zr getter temperature. The surface color of the Zr getter changes from metallic silver to dark gray as temperature increases. In the EDS results, the nitrogen component is not observed, and oxygen content increases from each surface at elevated temperatures. The Raman and XRD results show the oxidation layer as a result of 350 ℃ annealing. Therefore, the Zr getter can be applied as a nitrogen getter under 5-nine purity nitrogen atmosphere after appropriate oxidized pre-stabilization process to prevent rapid nitrification reaction.

Interaction between RING1 (R1) and the Ubiquitin-like (UBL) Domains Is Critical for the Regulation of Parkin Activity

Ham, Su Jin,Lee, Soo Young,Song, Saera,Chung, Ju-Ryung,Choi, Sekyu,Chung, Jongkyeong American Society for Biochemistry and Molecular Bi 2016 The Journal of biological chemistry Vol.291 No.4

<P>Parkin is an E3 ligase that contains a ubiquitin-like (UBL) domain in the N terminus and an R1-in-between-ring-RING2 motif in the C terminus. We showed that the UBL domain specifically interacts with the R1 domain and negatively regulates Parkin E3 ligase activity, Parkin-dependent mitophagy, and Parkin translocation to the mitochondria. The binding between the UBL domain and the R1 domain was suppressed by carbonyl cyanide m-chlorophenyl hydrazone treatment or by expression of PTEN-induced putative kinase 1 (PINK1), an upstream kinase that phosphorylates Parkin at the Ser-65 residue of the UBL domain. Moreover, we demonstrated that phosphorylation of the UBL domain at Ser-65 prevents its binding to the R1 domain and promotes Parkin activities. We further showed that mitochondrial translocation of Parkin, which depends on phosphorylation at Ser-65, and interaction between the R1 domain and a mitochondrial outer membrane protein, VDAC1, are suppressed by binding of the UBL domain to the R1 domain. Interestingly, Parkin with missense mutations associated with Parkinson disease (PD) in the UBL domain, such as K27N, R33Q, and A46P, did not translocate to the mitochondria and induce E3 ligase activity by m-chlorophenyl hydrazone treatment, which correlated with the interaction between the R1 domain and the UBL domain with those PD mutations. These findings provide a molecular mechanism of how Parkin recruitment to the mitochondria and Parkin activation as an E3 ubiquitin ligase are regulated by PINK1 and explain the previously unknown mechanism of how Parkin mutations in the UBL domain cause PD pathogenesis.</P>

불활성 가스의 O₂와 CO 불순물 제거를 위한 Ni 촉매의 물성 평가

김광배(Kwangbae Kim),진새라(Saera Jin),김은석(Eunseok Kim),임예솔(Yesol Lim),이현준(Hyunjun Lee),김성훈(Seonghoon Kim),노윤영(Yunyoung Noh),송오성(Ohsung Song) 한국산학기술학회 2020 한국산학기술학회논문지 Vol.21 No.4

반도체 산업용 9N 이상의 초고순도 N₂, Ar 등 불활성 가스 제조를 위해 가스 정제공정에 사용되고 있는 Ni 촉매의 물성 평가 및 촉매적 특성을 확인하였다. 조성이 다른 원기둥 형태의 C1, 츄러스 형태의 C2의 두 가지 Ni 촉매에 대해 비교 평가를 진행하였다. Ni 촉매의 형상과 미세구조를 분석하기 위해 광학현미경과 FE-SEM을 이용하였으며, 조성 확인 및 물성을 분석하기 위해 EDS, XRD, 그리고 micro-Raman 분석을 이용하였다. 또한 Ni 촉매의 비표면적 및 촉매적 특성을 확인하기 위해 BET, Pulse Titration 분석을 진행하였다. 조성 분석결과, C1의 경우, 상대적으로 graphite가 불순물로 다량 포함되어 있는 것을 확인하였으며, C2는 C1에 비해 Ni의 함량이 높은 것을 확인하였다. 비표면적 분석 결과, C2의 비표면적이 C1보다 약 1.69배 정도 큰 것을 확인할 수 있었다. 촉매적 특성분석 결과, 상온에서 O₂와 CO 불순물 제거 정도가 C2가 우수함을 확인하였다. 따라서 반도체 산업용 초고순도 불활성 기체 제조를 위한 Ni 촉매로는 불순물이 적고, 비표면적이 크며, 상온에서 O₂와 CO 제거 성능이 우수한 C2가 적합함을 확인하였다. This study examined the catalytic property of Ni-catalyst used in the gas purifying process to manufacture inert gases of N2 and Ar with high-purity over 9N for semiconductor industrial applications. Two types of Ni-catalysts with a cylindrical shape (C1) and churros shape structure (C2) were compared for the assessment. Optical microscopy and FESEM were used to analyze the shape and microstructure of the Ni-catalyst. EDS, XRD, and micro-Raman characterization were performed to examine the composition and properties. BET and Pulse Titration analyses were conducted to check the surface area and catalytic property of the Ni-catalyst. From the composition analysis results, C1 contained a relatively large amount of graphite as an impurity, and C2 contained higher Ni contents than C1. From specific surface area analysis, the specific surface area of C2 was approximately 1.69 times larger than that of C1. From catalytic property analysis, outstanding performance in O₂ and CO impurity removal was observed at room temperature. Therefore, C2, having low-impurity and large specific surface area, is a suitable catalyst for the high-purity inert gas process in the semiconductor industry because of its outstanding performance in O₂ and CO impurity removal at room temperature.

ZrVFe 다공체 표면오염층의 UVO₃ 크리닝 공정

김광배(Kwangbae Kim),김호준(Hojun Kim),진새라(Saera Jin),임예솔(Yesol Lim),이현준(Hyunjun Lee),김성훈(Seonghoon Kim),노윤영(Yunyoung Noh),송오성(Ohsung Song) 한국산학기술학회 2022 한국산학기술학회논문지 Vol.23 No.1

불활성 가스의 O₂와 CO 불순물 제거를 위한 Ni 촉매의 물성 평가

김광배,진새라,김은석,임예솔,이현준,김성훈,노윤영,송오성,Kim, Kwangbae,Jin, Saera,Kim, Eunseok,Lim, Yesol,Lee, Hyunjun,Kim, Seonghoon,Noh, Yunyoung,Song, Ohsung 한국산학기술학회 2020 한국산학기술학회논문지 Vol.21 No.4

반도체 산업용 9N 이상의 초고순도 N₂, Ar 등 불활성 가스 제조를 위해 가스 정제공정에 사용되고 있는 Ni 촉매의 물성 평가 및 촉매적 특성을 확인하였다. 조성이 다른 원기둥 형태의 C1, 츄러스 형태의 C2의 두 가지 Ni 촉매에 대해 비교 평가를 진행하였다. Ni 촉매의 형상과 미세구조를 분석하기 위해 광학현미경과 FE-SEM을 이용하였으며, 조성 확인 및 물성을 분석하기 위해 EDS, XRD, 그리고 micro-Raman 분석을 이용하였다. 또한 Ni 촉매의 비표면적 및 촉매적 특성을 확인하기 위해 BET, Pulse Titration 분석을 진행하였다. 조성 분석결과, C1의 경우, 상대적으로 graphite가 불순물로 다량 포함되어 있는 것을 확인하였으며, C2는 C1에 비해 Ni의 함량이 높은 것을 확인하였다. 비표면적 분석 결과, C2의 비표면적이 C1보다 약 1.69배 정도 큰 것을 확인할 수 있었다. 촉매적 특성분석 결과, 상온에서 O₂와 CO 불순물 제거 정도가 C2가 우수함을 확인하였다. 따라서 반도체 산업용 초고순도 불활성 기체 제조를 위한 Ni 촉매로는 불순물이 적고, 비표면적이 크며, 상온에서 O₂와 CO 제거 성능이 우수한 C2가 적합함을 확인하였다. This study examined the catalytic property of Ni-catalyst used in the gas purifying process to manufacture inert gases of N2 and Ar with high-purity over 9N for semiconductor industrial applications. Two types of Ni-catalysts with a cylindrical shape (C1) and churros shape structure (C2) were compared for the assessment. Optical microscopy and FESEM were used to analyze the shape and microstructure of the Ni-catalyst. EDS, XRD, and micro-Raman characterization were performed to examine the composition and properties. BET and Pulse Titration analyses were conducted to check the surface area and catalytic property of the Ni-catalyst. From the composition analysis results, C1 contained a relatively large amount of graphite as an impurity, and C2 contained higher Ni contents than C1. From specific surface area analysis, the specific surface area of C2 was approximately 1.69 times larger than that of C1. From catalytic property analysis, outstanding performance in O₂ and CO impurity removal was observed at room temperature. Therefore, C2, having low-impurity and large specific surface area, is a suitable catalyst for the high-purity inert gas process in the semiconductor industry because of its outstanding performance in O₂ and CO impurity removal at room temperature.