Effects of hydrogen plasma treatment on SnO2:F substrates for amorphous Si thin film solar cells

Min-Seung Choi,Young-Ju Lee,Jung-Dae Kwon,Yongsoo Jeong,Ju-Yun Park,강용철,Pung Keun Song,Dong-Ho Kim 한국물리학회 2013 Current Applied Physics Vol.13 No.8

We investigated the effects of hydrogen plasma treatment on the physical and electrical properties of fluorine-doped tin oxide (FTO) films used for amorphous silicon (a-Si) thin film solar cells. A slight increase in carrier concentration by the hydrogen doping effect was observed for the FTO film exposed to the hydrogen plasma for 5 min. For further exposure to the plasma, the chemical reduction became prominent and resulted in deterioration of the electrical and optical properties of the film. XPS analysis revealed that the chemical reduction of SnO2 to Sn metallic state occurs on the surface region. It was found that the defects formed by hydrogen plasma act as recombination centers at the interface between FTO electrode and p-layer of a-Si solar cells. This phenomenon resulted in the deterioration of the cell performance. The averaged conversion efficiency (6.82%) of the cells on pristine FTO hydrogen substrate was decreased to 5.81% for the cells on FTO treated for 5 min, which is mainly attributed to the decrease in short-circuit current density.

Antioxidant and hepatoprotective effects of Korean ginseng extract GS-KG9 in a D-galactosamine-induced liver damage animal model

Yun Ho Jo,Hwan Lee,Myeong Hwan Oh,Gyeong Hee Lee,You Jin Lee,Ji Sun Lee,Min Jung Kim,Won Yong Kim,Jin Seong Kim,Dae Seok Yoo,Sang Won Cho,Seon Woo Cha,Mi Kyung Pyo 한국영양학회 2020 Nutrition Research and Practice Vol.14 No.4

BACKGROUND/OBJECTIVES: This study was designed to investigate the improvement effect of white ginseng extract (GS-KG9) on D-galactosamine (Ga1N)-induced oxidative stress and liver injury. SUBJECTS/METHODS: Sixty Sprague-Dawley rats were divided into 6 groups. Rats were orally administrated with GS-KG9 (300, 500, or 700 mg/kg) or silymarin (25 mg/kg) for 2 weeks. The rats of the GS-KG9- and silymarin-treated groups and a control group were then intraperitoneally injected Ga1N at a concentration of 650 mg/kg for 4 days. To investigate the protective effect of GS-KG9 against GalN-induced liver injury, blood liver function indicators, anti-oxidative stress indicators, and histopathological features were analyzed. RESULTS: Serum biochemical analysis indicated that GS-KG9 ameliorated the elevation of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) in GalN-treated rats. The hepatoprotective effects of GS-KG9 involved enhancing components of the hepatic antioxidant defense system, including glutathione, glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT). In addition, GS-KG9 treatment inhibited reactive oxygen species (ROS) production induced by GalN treatment in hepatocytes and significantly increased the expression levels of nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) proteins, which are antioxidant proteins. In particular, by histological analyses bases on hematoxylin and eosin, Masson"s trichrome, α-smooth muscle actin, and transforming growth factor-β1 staining, we determined that the administration of 500 mg/kg GS-KG9 inhibited hepatic inflammation and fibrosis due to the excessive accumulation of collagen. CONCLUSIONS: These findings demonstrate that GS-KG9 improves GalN-induced liver inflammation, necrosis, and fibrosis by attenuating oxidative stress. Therefore, GS-KG9 may be considered a useful candidate in the development of a natural preventive agent against liver injury.

Polysulfone에 Di-(2-ethylhexyl)-phosphoric acid와 Carbon Nanotubes를 고정화한 PSf/D2EHPA/CNTs 비드의 제조와 Sr(II)의 제거 특성

이민규 ( Min-gyu Lee ),윤종원 ( Jong-won Yun ),서정호 ( Jung-ho Suh ) 한국화학공학회 2017 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.55 No.6

본 연구에서는 di-(2-ethylhexyl)-phosphoric acid (D2EHPA)와 carbon nanotubes (CNTs)를 polysulfone (PSf)에 고정화시켜 PSf/D2EHPA/CNTs 비드를 제조하였으며, 제조한 비드에 의한 Sr(II)의 제거특성을 살펴보았다. Scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FTIR) 및 Thermo gravimetric analysis (TGA) 분석을 통하여 PSf/D2EHPA/CNTs 비드의 형태적 특성들을 조사하였다. PSf/D2EHPA/CNTs 비드에 의한 Sr(II)의 제거는 운전시간 60 min 정도에서 평형에 도달하였으며, 속도 실험결과는 유사 2차 속도식에 잘 부합하는 것으로 나타났다. 또한 PSf/D2EHPA/CNTs 비드에 의한 Sr(II)의 제거에서 Langmuir 식으로부터 구한 최대 제거량은 4.75 mg/g이었다. PSf/D2EHPA/CNTs 비드에 의한 Sr(II)의 제거효율은 추출제 D2EHPA 만을 사용하는 경우보다 CNTs를 첨가함으로써 Sr(II)의 제거량이 2.5배 정도 향상되는 결과를 보였다. PSf/D2EHPA/CNTs beads were prepared by immobilizing extractant di-(2-ethylhexyl)- phosphoric acid (D2EHPA) and adsorbent carbon nanotubes (CNTs) on polysulfone (PSf), and the adsorption characteristics of Sr(II) on the beads were studied. The morphological characteristics of the prepared PSf/D2EHPA/CNTs beads were observed by scanning electron microscopy (SEM), thermo gravimetric analysis (TGA), and Fourier transform infrared spectrometer (FTIR). The equilibrium time for the removal of Sr(II) by PSf/D2EHPA/CNTs beads was 60 min. The experimental kinetic data followed pseudo-second-order model more than pseudo-first-order kinetics model. The maximum removal capacity of Sr(II) obtained from Langmuir isotherm was 4.75 mg/g. The removal efficiencies of Sr (II) by PSf/D2EHPA/CNTs beads were improved 2.5 times by adding the adsorbent CNTs more than by using only the extractant D2EHPA.

심근 허혈-재관류 백서 모델에서 mitogen-activated protein kinase 활성화에 대한 α-lipoic acid의 효과

김연경,박은미,최준호,윤경호,유남진,이은미,김남호,정진원,김민선,박병림,오석규 圓光大學校 醫科學硏究所 2006 圓光醫科學 Vol.21 No.1

크론병에 대한 CoPPLX의 방어효과에 대한 연구

이호학,김유림,문창기,이재일,양병윤,김종수,이정민,정재혁,안석진,박상준,김윤권,김소연,김영중,조민구,최영자,장성조 圓光大學校 醫科學硏究所 2005 圓光醫科學 Vol.20 No.1

Vascular Protective Role of Samul-Tang in HUVECs: Involvement of Nrf2/HO-1 and NO

Choi, Eun Sik,Lee, Yun Jung,Seo, Chang Seob,Yoon, Jung Joo,Han, Byung Hyuk,Park, Min Cheol,Kang, Dae Gill,Lee, Ho Sub Hindawi Publishing Corporation 2016 Evidence-based Complementary and Alternative Medic Vol.2016 No.-

<P>Samul-Tang (Si-Wu-Tang, SMT), composed of four medicinal herbs, is a well-known herbal formula treating hematological disorder or gynecologic disease. However, vascular protective effects of SMT and its molecular mechanisms on the vascular endothelium, known as the central spot of vascular inflammatory process, are not reported. The aim of this study was to investigate vascular protective effects of SMT water extract in human umbilical vein endothelial cells (HUVECs). Water extract of SMT was prepared and identified by HPLC-PDA analysis. Expression of cell adhesion molecules (CAMs) and heme oxygenase-1 (HO-1) and translocation of nuclear factor-kappa B (NF-<I>κ</I>B) and nuclear factor-erythroid 2-related factor 2 (Nrf2) were determined by western blot. Nuclear localization of NF-<I>κ</I>B and Nrf2 was visualized by immunofluorescence and DNA binding activity of NF-<I>κ</I>B was measured. ROS production, HL-60 monocyte adhesion, and intracellular nitric oxide (NO) were also measured using a fluorescent indicator. SMT suppressed NF-<I>κ</I>B translocation and activation as well as expression of CAMs, monocyte adhesion, and ROS production induced by TNF-<I>α</I> in HUVECs. SMT treated HUVECs showed upregulation of HO-1 and NO which are responsible for vascular protective action. Our study suggests that SMT, a traditionally used herbal formula, protects the vascular endothelium from inflammation and might be used as a promising vascular protective drug.</P>

<i>Prunella vulgaris</i> Suppresses HG-Induced Vascular Inflammation via Nrf2/HO-1/eNOS Activation

Hwang, Sun Mi,Lee, Yun Jung,Yoon, Jung Joo,Lee, So Min,Kim, Jin Sook,Kang, Dae Gill,Lee, Ho Sub Molecular Diversity Preservation International (MD 2012 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.13 No.1

<P>Vascular inflammation is an important factor which can promote diabetic complications. In this study, the inhibitory effects of aqueous extract from <I>Prunella vulgaris</I> (APV) on high glucose (HG)-induced expression of cell adhesion molecules in human umbilical vein endothelial cells (HUVEC) are reported. APV decreased HG-induced expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. APV also dose-dependently inhibited HG-induced adhesion of HL-60 monocytic cells. APV suppressed p65 NF-κB activation in HG-treated cells. APV significantly inhibited the formation of intracellular reactive oxygen species (ROS). HG-stimulated HUVEC secreted gelatinases, however, APV inhibited it. APV induced Akt phosphorylation as well as activation of heme oxygenase-1 (HO-1), eNOS, and nuclear factor E2-related factor 2 (Nrf2), which may protect vascular inflammation caused by HG. In conclusion, APV exerts anti-inflammatory effect via inhibition of ROS/NF-κB pathway by inducing HO-1 and eNOS expression mediated by Nrf2, thereby suggesting that <I>Prunella vulgaris</I> may be a possible therapeutic approach to the inhibition of diabetic vascular diseases.</P>

Anti-Proliferative Effect of an Aqueous Extract of <i>Prunella vulgaris</i> in Vascular Smooth Muscle Cells

Hwang, Sun Mi,Lee, Yun Jung,Lee, Yong Pyo,Yoon, Jung Joo,Lee, So Min,Cha, Jeong Dan,Choi, Kyung Min,Kang, Dae Gill,Lee, Ho Sub Hindawi Publishing Corporation 2013 Evidence-based Complementary and Alternative Medic Vol.2013 No.-

<P>The abnormal proliferation of vascular smooth muscle cells (VSMCs) in arterial walls is an important pathogenic factor of vascular disorders such as diabetic atherosclerosis. We have reported the anti-inflammatory effect of an aqueous extract from <I>Prunella vulgaris</I> (APV) in vascular endothelial cell. In the present study, APV exhibited inhibitory effects on high glucose-stimulated VSMC proliferation, migration, and invasion activities, inducing G<SUB>1</SUB> cell cycle arrest with downregulation of cyclins and CDKs and upregulation of the CKIs, p21<SUP>waf1/cip1</SUP> and p27<SUP>kip1</SUP>. Furthermore, APV dose dependently suppressed the high glucose-induced matrix metalloproteinase activity. High glucose-induced phosphorylation of ERK, p38 MAPK, was decreased by the pretreatment of APV. NF-<I><I>κ</I></I>B activation by high glucose was attenuated by APV, as an antioxidant. APV attenuated the high glucose-induced decrease of nuclear factor E2-related factor-2 (Nrf2) translocation and heme oxygenase-1 (HO-1) expression. Intracellular cGMP level was also increased by APV treatment. These results demonstrate that APV may inhibit VSMC proliferation via downregulating ROS/NF-<I><I>κ</I></I>B /ERK/p38 MAPK pathways. In addition, APV has a beneficial effect by the interaction of Nrf2-mediated NO/cGMP with HO-1, suggesting that <I>Prunella vulgaris</I> may be useful in preventing diabetic atherosclerosis.</P>

Purification and Characterization of Helicobacter pylori ${\gamma}$-Glutamyltranspeptidase

Song, Jae-Young,Choi, Yeo-Jeong,Kim, Jeong-Min,Kim, Yoo-Ree,Jo, Jin-Seong,Park, Jin-Sik,Park, Hee-Jin,Song, Yun-Gyu,Lee, Kon-Ho,Kang, Hyung-Lyun,Baik, Seung-Chul,Youn, Hee-Shang,Cho, Myung-Je,Rhee, Kw The Korean Society for Microbiology 2011 Journal of Bacteriology and Virology Vol.41 No.4

Gamma-glutamyltranspeptidase (GGT) was purified to electrophoretic homogeneity from the cell extract of H. pylori. The purified enzyme consisted of heavy and light subunits with molecular weights of 38 kDa and 21 kDa, respectively. N-terminal amino acid sequence of heavy and light subunits revealed that H. pylori GGT was processed into 3 parts for a signal peptide of 27 amino acid residues, a heavy subunit of 352 residues, and a light subunit of 188 residues during translation. The reaction rate for hydrolysis of ${\gamma}$-GpNA was 84.4 ${\mu}mol/min$ per milligram of protein, and that for the ${\gamma}$-glutamyl transfer from ${\gamma}$-GpNA to gly-gly was 23.8 ${\mu}mol/min$ per milligram of protein. The apparent Km values of H. pylori GGT for ${\gamma}$-glutamyl compounds were on the order of $10^{-3}$ to $10^{-4}$ M and those for acceptor peptides and amino acids were on the order of $10^{-1}$ to $10^{-2}$ M. The GGT protein kept approximately 80% of the initial enzymatic activity on incubation at $60^{\circ}C$ for 15 min. The optimum temperature and pH for reactions of both hydrolysis and transpeptidation were $40^{\circ}C$ and 9.0, respectively. The transpeptidation and hydrolysis reactions catalyzed by H. pylori GGT were strongly inhibited by L-Gln and moderately inhibited by L-Ala, L-Ser, ${\beta}$-chloro-L-Ala, and L-Glu. These results demonstrated that the biochemical properties of H. pylori GGT are different from those of other bacterial GGTs. Further, H. pylori GGT might degrade glutathione in the gastric mucous layer of humans if the enzyme could be secreted in the bacterial niches.

브라켓 부착을 위한 변형된 레이저 부식법

윤민성,이상민,양병호 대한치과교정학회 2010 대한치과교정학회지 Vol.40 No.2

전단결합강도를 강화하기 위해 레이저를 이용한 부식과 산을 이용한 부식의 비교 연구가 많이 진행되어왔다. 본 연구에서는 Er,Cr:YSGG laser와 전통적인 산부식법을 혼합한 방법의 전단결합강도의 변화에 대한 평가를 하고자 한다. 교정적인 목적으로 발치된 64개의 건전한 소구치를 이용하여 16개씩 4개의 군으로 나누었다. 첫 번째 군은 37% 인산을 15초 적용시키는 전통적인 부식 방법을 택하였고, 두 번째 군은 물방울레이저로 1.5 W로 10초간 부식시킨 후 전통적인 산부식 방법을 시행하였다. 세 번째 군은 두 번째 군과 같지만 산부식을 먼저 시행한 후 물방울레이저로 부식시켰다. 네 번째 군은 물방울레이저를 이용하여 1.5 W로 15초간 부식시켰다. 이후 전단결합강도의 측정 및 치아 표면의 특징 관찰, 그리고 접착제잔류지수를 평가하였다. 두 번째, 세 번째 군은 첫 번째, 네 번째 군에 대하여 전단결합강도가 높게 측정되었다. 하지만 두 가지 기법의 복합사용 순서를 달리한 두 번째, 세 번째 군 사이에는 통계적으로 유의한 차이가 나지 않았다. 기존 산부식을 이용한 브라켓 접착법보다 산부식과 Er,Cr:YSGG laser를 복합적으로 사용 시, 향상된 전단결합강도를 얻을 수 있다. Objective: Many studies have carried out research on comparisons between laser etching and conventional etching systems to investigate methods of reinforcing shear bond strength. The purposes of this study were to assess the efficiency of bonding with erbium, chromium doped: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser etching combined with the conventional etching technique. Methods: Sixty-four sound premolars, extracted for orthodontic purposes, were randomly divided into 4 groups and treated in the following manner. First group, conventional etching of 37% phosphoric acid for 15 seconds (control); second group, 1.5 W laser etching for 10 seconds followed by conventional etching; third group, conventional etching followed by 1.5 W laser etching; fourth group, 1.5 W laser etching for 15 seconds only. We assessed the shear bond strength, the surface characteristics, and the adhesive remnant index scores between all groups. Results: Experimental groups showed higher shear bond strength than the control group. But no statistically significant differences were found between the second and third groups. Adhesive remnant scores were compared with the Kruskal-Wallis test, and no statistically significant differences were found between all groups. Conclusions: To obtain maximum shear bonding strength, a combined technique of Er,Cr:YSGG and 37% phosphoric acid is useful even though it may be inconvenient.