Simple and cost-effective fabrication of size-tunable zinc oxide architectures by multiple size reduction technique

Park, Hyeong-Ho,Zhang, Xin,Hwang, Seon-Yong,Jung, Sang Hyun,Kang, Semin,Shin, Hyun-Beom,Kang, Ho Kwan,Park, Hyung-Ho,Hill, Ross H,Ko, Chul Ki Elsevier 2012 SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS Vol.13 No.2

<P>We present a simple size reduction technique for fabricating 400 nm zinc oxide (ZnO) architectures using a silicon master containing only microscale architectures. In this approach, the overall fabrication, from the master to the molds and the final ZnO architectures, features cost-effective UV photolithography, instead of electron beam lithography or deep-UV photolithography. A photosensitive Zn-containing sol–gel precursor was used to imprint architectures by direct UV-assisted nanoimprint lithography (UV-NIL). The resulting Zn-containing architectures were then converted to ZnO architectures with reduced feature sizes by thermal annealing at 400 °C for 1 h. The imprinted and annealed ZnO architectures were also used as new masters for the size reduction technique. ZnO pillars of 400 nm diameter were obtained from a silicon master with pillars of 1000 nm diameter by simply repeating the size reduction technique. The photosensitivity and contrast of the Zn-containing precursor were measured as 6.5 J cm<SUP>−2</SUP> and 16.5, respectively. Interesting complex ZnO patterns, with both microscale pillars and nanoscale holes, were demonstrated by the combination of dose-controlled UV exposure and a two-step UV-NIL.</P>

Molecular identification and functional delineation of a glutathione reductase homolog from disk abalone (<i>Haliotis discus discus</i>): Insights as a potent player in host antioxidant defense

Herath, H.M.L.P.B.,Wickramasinghe, P.D.S.U.,Bathige, S.D.N.K.,Jayasooriya, R.G.P.T.,Kim, Gi-Young,Park, Myoung Ae,Kim, Chul,Lee, Jehee Elsevier 2017 FISH AND SHELLFISH IMMUNOLOGY Vol.60 No.-

<P><B>Abstract</B></P> <P>Glutathione reductase (GSR) is an enzyme that catalyzes the biochemical conversion of oxidized glutathione (GSSG) into the reduced form (GSH). Since the ratio between the two forms of glutathione (GSH/GSSG) is important for the optimal function of GSH to act as an antioxidant against H<SUB>2</SUB>O<SUB>2</SUB>, the contribution of GSR as an enzymatic regulatory agent to maintain the proper ratio is essential. Abalones are marine mollusks that frequently encounter environmental factors that can trigger the overproduction of reactive oxygen species (ROS) such as H<SUB>2</SUB>O<SUB>2</SUB>. Therefore, we conducted the current study to reveal the molecular and functional properties of a GSR homolog in the disk abalone, <I>Haliotis discus discus</I>. The identified cDNA sequence (2325 bp) has a 1356 bp long open reading frame (ORF), coding for a 909 bp long amino acid sequence, which harbors a pyridine nucleotide-disulfide oxidoreductase domain (171–246 aa), a pyridine nucleotide-disulfide oxidoreductase dimerization domain, and a NAD(P)(+)-binding Rossmann fold superfamily signature domain. Four functional residues: the FAD binding site, glutathione binding site, NADPH binding motif, and assembly domain were identified to be conserved among the other species. The recombinant abalone GSR (rAbGSR) exhibited detectable activity in a standard glutathione reductase activity assay. The optimum pH and optimal temperature for the reaction were found to be 7.0 and 50 °C, respectively, while the ionic strength of the medium had no effect. The enzymatic reaction was vastly inhibited by Cu<SUP>+2</SUP> and Cd<SUP>+2</SUP> ions. A considerable effect of cellular protection was detected with a disk diffusion assay conducted with rAbGSR. Moreover, an MTT assay and flow cytometry confirmed the significance of the protective role of rAbGSR in cell function. Furthermore, <I>AbGSR</I> was found to be ubiquitously distributed in different types of abalone tissues. <I>AbGSR</I> mRNA expression was significantly upregulated in response to three immune challenges: <I>Vibrio parahaemolyticus</I>, <I>Listeria monocytogenes</I>, and lipopolysaccharide (LPS), thus indicating its possible involvement in host defense mechanisms during pathogenic infections. Taken together, the results of the current study suggest that AbGSR plays an important role in antioxidant-mediated host defense mechanisms and also provide insights into the immunological contribution of AbGSR.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We identified a glutathione reductase homolog (AbGSR) from disk abalone. </LI> <LI> AbGSR resembled functionally important domain architecture of GSR family. </LI> <LI> Recombinant AbGSR confirmed its biochemical properties via enzymatic assays. </LI> <LI> First functional antioxidant properties assessment of a molluscan GSR. </LI> <LI> <I>AbGSR</I> expression was modulated upon induced pathogen stress in gill and hemocytes. </LI> </UL> </P>

Phytosociological Community Classification of Mountain Ridge from Guryongryeong to Mt. Yaksu in the Baekdudaegan, Korea

An, Hyun-Chul,Choo, Gab-Chul,Park, Sam-Bong,Cho, Hyun-Seo,An, Jong-Bin,Park, Jeong-Geun,Ha, Hyoun Woo,Kim, Jin Joong,Kim, Bong-Gyu 한국환경생태학회 2014 한국환경생태학회지 Vol.28 No.6

백두대간 구룡령-약수산 마루금에 22개의 방형구(100m2)를 설정하여 식생을 조사하였다. 식생군집을 분석한 결과 신갈나무-까치박달나무-당단풍나무군집, 신갈나무군집, 층층나무-신갈나무군집 등 3개의 군집으로 분류되었다. 백두대간 구룡령-약수산 마루금은 대부분 신갈나무가 우점하고 있었으며, 일부지역에서 까치박달나무와 층층나무 등이 혼효하고 있었다. 수종간의 상관관계에서 신갈나무와 노린재나무, 철쭉; 피나무와 찰피나무, 노린재나무; 찰피나무와 노린재나무, 철쭉; 거제수나무와 고로쇠나무; 노린재나무와 철쭉 등의 수종 간에는 높은 정의 상관이 인정되었다. 당단풍나무와 노린재나무, 철쭉 등의 수종 간에는 높은 부의 상관이 인정되었다. 조사지의 군집별 종다양성 지수는 0.8170~1.1446범위로 백두대간에 위치한 국립공원들의 능선부 식생구조 보다는 약간 낮게 나타났다. To investigate the vegetation structure of mountain ridge from Guryongryeong to Mt. Yaksu, 22 plots (100m2) installed with random sampling method were surveyed. Three groups of Quercus mongolica-Acer pseudosieboldianum community, Q. mongolica community, Cornus controversa-Q. mongolica community were classified by cluster analysis. Q. mongolica was a major woody plant species in the ridge area from Guryongryeong to Yaksusan and Carpinus cordata and C. controversa was partly occupied in some area. High positive correlations showed between Q. mongolica and Symplocos chinensis for. pilosa, Rhododendron schlippenbachii; Tilia amurensis and Tilia mandshurica, Symplocos chinensis for. pilosa; Tilia mandshurica and S. chinensis for. pilosa, R. schlippenbachii; Betula costata and Acer mono; Symplocos chinensis for. pilosa and Rhododendron schlippenbachii, and relatively high negative correlations showed between A. pseudosieboldianum and S. chinensis for. pilosa, R. schlippenbachii. Species diversity(H') of investigated groups were ranged 0.8170~1.1446 and it was lower compared to those of the ridge area of the national parks in Baekdudaegan.

Protection of Human Fibroblasts from Reactive Oxygen Species by Green Tea Polyphenolic Compounds

Han, Dong Wook,Kim, H.H.,Son, Hyun Joo,Baek, Hyun Sook,Lee, Kwon Yong,Hyon, Suong Hyu,Park, Jong Chul Trans Tech Publications, Ltd. 2005 Key Engineering Materials Vol.288 No.-

<P>The potential protective roles played by green tea compounds (GTPCs) against reactive oxygen species-induced oxidative stress in cultured fetal human dermal fibroblasts (fHDFs) were investigated according to cell viability measurement methods, such as fluorescence double staining followed by flow cytometry (FCM), MTT assay and crystal violet uptake. Oxidative stress was induced in the fHDFs, either by adding 50 mM H2O2 or by the action of 40 U/L xanthine oxidase (XO) in the presence of xanthine (250 µM). FCM analysis was the most suitable to show that both treatments produced a significant (p < 0.05) reduction in the fHDF viability, attributed to its high sensitivity. On the microscopic observations, the cell death with necrotic morphology was appreciably induced by both treatments. These oxidative stress-induced damages were significantly (p < 0.05) prevented by pre-incubating the fHDFs with 200 µg/ml GTPC for 1 h. These results suggest that GTPC can act as a biological antioxidant in a cell culture experimental model and prevent oxidative stress-induced cytotoxicity in cells.</P>

셀레콕시브 및 그 합성유도체들의 항암활성 스크리닝

박정란,강진형,구효정,노지영,류형철,박상욱,고동현,조일환,이주영,황다니엘,김인경 한국약제학회 2003 Journal of Pharmaceutical Investigation Vol.33 No.2

Selective COX (cyclooxygenase)-2 inhibitors including celecoxib have been shown to induce apoptosis and cell cycle changes in various tumor cells. New inhibitors are recently being developed as chemomodulating agents. We evaluated celecoxib and screened 150 synthetic compounds for anti-proliferative activities in vitro. Effects of celecoxib on COX activity, cell growth, cell cycle distribution, and apoptosis induction were determined in A549 COX-2 overexpressing human non-small cell lung cancer (NSCLC) cells. The COX inhibition of celecoxib increased with concentration up to 82% at 1μM after 24 hr exposure. Forty μM and 50μM of celecoxib induce G_1 arrest, and TUNEL-positive apoptotic cells, respectively. Among 150 compounds, several compounds were selected for having greater COX-2 inhibitory activity and higher selectivity than celecoxib with growth inhibitory activity. Celecoxib showed concentration-dependent COX inhibitory activity, and ability to induce cell cycle arrest and apoptosis in human NSCLC cells in vitro. Among synthetic analogues screened, several compounds showed promising in vitro activity as COX-2 inhibitory anticancer agents, which warrant further evaluation in vitro and in vivo.

포상기태와 융모상피암 환자의 갑상선기능

박기현,김현만,허갑범,이현철,김경래,김한수,김주항,김세광 대한내분비학회 1988 Endocrinology and metabolism Vol.3 No.1

It has been recognized that hyperthyroidism occur in patients with trophoblastic disease, either hydatidiform moles or choriocarcinomas. In the past decade, several lines of evidence have shown that human chorionic gonadotropin, secreted by the trophoblastic disease, is a thyroid stimulator and causes hyperthyroidism. In order to evaluate the relationship between level of thyroid hormone and human chorionic gonadotropin in patients with trophoblastic disease, level of thyroid hormone, serum -HCG and amount of urinary excretion of HCG were measured and analyzed in 24 patients with hydatidiform mole and 11 patients with choriocarcinoma who were admitted to Yonsei University Severance Hospital during the period from January 1981 to December 1986. The results are summarzed as follows: 1) Hyperthyroidism was observed in 33.3% of the patients with hydatidiform mole and in 18.2% of the patients with choriocarcinoma. 2) The amount of 24 hour urinary excretion of HCG in patients with hyperthyroidism was more than that in euthroid patients. 3) There was no difference in the level of thyroid hormone, serum -HCG, and amount of 24 hour urinary excretion of HCG in patients with hydatidifrom mole and choriocarcinoma. 4) The amount of 24 hour urinary excretion of HCG had significant correlation with FT4, whereas no similar correlation was observed between the levels of thyroid hormone and serum -HCG. In conclusion, the occurrence of hyperthyroidism is closely related with the amount of urinary excretion of HCG in patients with trophblastic disease.

Aromatization of n-Hexane over HZSM-5 Type Catalysts Modified with Gallium

Lee, J.-W 한국화학공학회 1996 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.34 No.1

향나무類를 加害하는 알락명나방亞科의 韓國未記錄 1種 Dioryctria juniperella Yamanaka(나비目, 명나방科)

Bong-Kyu BYUN,Chul-Ha PARK,H. YAMANAKA,Buom-Young LEE 한국응용곤충학회 1997 한국응용곤충학회지 Vol.36 No.2

향나무류를 가해하는 향나무알락명나방(신칭)을 우리나라 미기록종으로 보고하며 성충 및 유충의 외부형태적 특징을 간략히 기술하였다. 금번조사를 통해 향나무, 누운향나무, 옥향나무 등 3종이 기주로 확인되었으며, 유충은 기주의 잎을 엮고 그 안에서 가해하는 것으로 조사되었다. A Phycitine species, Dioryctiria juniperella Yamanaka, is reported for the first time from Korea. Larval characters is also shown with its illustration. Juniperus chinensis L., J. chinensis var. globosa H., and J. procumbens S. are known as host plants for the species in this country.

선택적 남성 호르몬 분비 부신피질 종양 1예

김동수,박정수,이상주,이병석,박기현,박찬규,허갑범,이현철,이관우,김미림,이명래 대한내분비학회 1989 Endocrinology and metabolism Vol.4 No.2

한국 최초의 경주시 황남동 출토 유리 용융 도가니 및 유리 구슬에 대한 연구

최주,안재호,황상주,권희경,김수철,도정만,박기훈,김선태 한국전통과학기술학회 1994 한국전통과학기술학회지 Vol.1 No.1

A piece of glass melting crucible whose inner face was lined with yellowish brown glass, a yellowish brown ellipsoidal bead and a greenish scrcew-shaped wound bead were unearthed in Kyongju city. These finds were dated to around the middle of the 6th century by pattern impressed earthenwares excavated in the same stratum. Chcmica analyses were carried out by means of energy diapersive spectrometry(EDS), atomic absorption analysis(AA), induced coupling plasma analysis(ICP) along with conventional wet analvsis. Also X-ray and elecrtron diffraction analvses were periomd in an attempt to identify any crystalline precipitates. Three glass items are classified iota lead-silica group showing the same compositions. This indicates that the two beads are from the same crucible. Ywllowish brown glass film contains 72.5% PbO and 25.2% SiO₂ and its softening point is 442℃ which is determined by differential scanning calorimeter(DSC). Melting point is found to be around 650℃ by practical measurement. Color differences in two beads are proved to be mainly due to copper contained in the glass, i.e., yellowish brown and greenish colors depend on reduction and oxidation atmosphere during melting, respectively. Chemical analysis shows that the glass melting crucible is a common earthenware.