녹용에서 당 함유 물질의 분리 및 분석

한나영,전길자 이화여자대학교 생명과학연구소 1992 생명과학연구논문집 Vol.3 No.-

녹용의 생리활성 물질을 연구하기 위하여 당이 함유된 부분의 성분을 Folch-Suzuki분배방법,Sephadex G-50 chromatography, DEAE-Sephadex A-25 chromatography, High Performance Liquid Chromatograpy (HPLC)로 분리 정제하고 FAB-MS를 이용하여 구조를 분석하였다. 각 단계에서 당지질을 확인하는 방법으로 High Performance Thin Layer Chromatography(HPTLC)를 수행하였다. Chloroform-methanol-0.88% KCI수용액을 사용하여 분배된 수용액층을 Sephadex G-50 column에서 분리하였을 때, void volume에서 대부분의 당지질이 용출되는 것으로 보아 micelle을 형성하고 있음을 알 수 있었다. Sephadex G-50 column에서 용출되는 당지질을 DEAE-Sephadex A-25 chromatography결과 band 1(녹용에 존재하는 당지질중 주요성분)을 포함하는 대부분의 당지질이 농도 기울기를 걸기 전에서 용출되었다. 따라서 band1을 중성 당지질로 예측할 수 있었다. Band 1을 HPLC로 분석한 결과 4개의 peak로 분리되었다. 그 중 가장 많은 양으로 존재하며(48.5%), 3.17분 대에서 용출되는 부분만을 모아 negative-ion FAB-MS로 분석한 결과 이미지 물질은 분자량이 1058이고, 98-240-240-240-240Ehsms 98-98-142-98-142-98 -124-98-142의 분자구조를 가지는 것으로 확인할 수 있었다. The major component of glycolipids in antler was investigated by Folch-Suzuki partition method, Sephadex G-50 chromatography, DEAE-Sephadex A-25 chromatography, High Performance Liquid Chromatograpy HPLC, and FAB-MS. Glycolipids, extracted in aqueous phase by chloroform-methanol-0.88% KCI aqueous solution, were analyzed on Sephadex G-50 column and most glycolipids containing band1 were eluted in void volume because of the formation of micelles. The major fractions pooled from Sephadex G-50 column were eluted before gradient elution on DEAE-Sephadex A-25 column due to neutral property. Band 1 extracted from HPTLC plate was injected on HPLC column(μ-Bondapak NH_2 column)and four peaks were separated. The fractions containing major peak(3.17 min,48.5%)werepooled and analyzed by negative-ion FAB-MS. As the result, it has been identified that molecular weight of major component is 1058 and structural fragments is 98-98-142-98-142-98-142-98-142 or 98-240-240-240-240.

Reduced graphene oxide functionalized with Cu nanoparticles: Fabrication, structure, and sensing properties

Na, Han Gil,Cho, Hong Yeon,Kwon, Yong Jung,Kang, Sung Yong,Lee, Chongmu,Jung, Taek Kyun,Lee, Hyo-Soo,Kim, Hyoun Woo Elsevier 2015 THIN SOLID FILMS - Vol.588 No.-

<P><B>Abstract</B></P> <P>We have fabricated the NO<SUB>2</SUB> gas sensors by using reduced graphene oxide (RGO) functionalized with copper (Cu) nanoparticles, revealing that the sensitivity was significantly enhanced by the Cu functionalization. Transmission electron microscopy indicated that the nanoparticles with a cubic Cu phase were attached on the surface of RGO. Raman spectra revealed that the structural disorder of RGO was increased by the Cu-functionalization. We performed the NO<SUB>2</SUB> gas sensing test, revealing that the sensor response of RGOs was increased by 326% by means of the Cu-functionalization. We have discussed the associated mechanisms. In addition, we have ascribed the functionalization-induced changes of response and recovery times to the increase of low-energy binding sites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We fabricated NO<SUB>2</SUB> gas sensors by using RGOs functionalized with Cu nanoparticles. </LI> <LI> The sensitivity was significantly enhanced by the Cu functionalization. </LI> <LI> We examined changes in response and recovery times by the Cu functionalization. </LI> </UL> </P>

Synthesis of Ge-doped SnO2 nanowires and their photoluminescence propertiess

Han Gil Na 한양대학교 세라믹연구소 2013 Journal of Ceramic Processing Research Vol.14 No.3

We synthesized Ge-doped SnO2 nanowires by heating a mixture of Sn and Ge powders. The dominant growth mechanisms turned out to be a vapor-solid (VS) process. Photoluminescence (PL) study at 7 K revealed that 2.2 eV-band and 2.6 eV-bands have been significantly intensified and reduced, respectively, by introducing the Ge elements. With the assistance of XPS and Raman spectra, we suggested that the intensification of 2.2 eV-band originated from the GeO2 phase. Since XRD spectra, lowmagnification transmission electron microscopy (TEM) image and selected area electron diffraction coincidentally negated the presence of crystalline GeO2 phase, we suggest that the GeO2 structure is mainly amorphous.

Development of defects in ZnO/RGO composites under wet chemical synthesis

Na, Han Gil,Jung, Taek-Kyun,Ryou, Min,Lee, Ji-Woon,Hyun, Soong-Keun,Kang, Sung Yong,Mirzaei, Ali,Bonyani, Maryam,Kim, Kyung-Taek,Choi, Ho-Joon,Kim, Hyoun Woo,Jin, Changhyun Elsevier 2018 Optik Vol.156 No.-

<P><B>Abstract</B></P> <P>ZnO/reduced graphene oxide (RGO) heterostructures were fabricated using a simple two-step wet chemical technique and post-annealing treatment. ZnO nanoparticles with different sizes (20–200 nm) and shapes were randomly distributed on mono- and/or multi-layered RGO sheets. The microstructures of the ZnO/RGO composites examined using transmission electron microscopy indicated that the heterostructures are polycrystalline in nature, implying the possibilities of diverse defects present in the samples. The photoluminescence spectra examinations revealed the enhancement of defect-level emission peaks observed at a relatively long wavelength ranges (i.e., 779 nm, 666 nm, and 574 nm) as compared with the band to band transition observed at relatively short wavelengths (i.e., 378 nm).</P>

Improved Sensing Behaviors in Reduced Graphene Oxide Functionalized with Ni(OH)₂ Nanoparticles

Na, Han Gil,Kwon, Yong Jung,Cho, Hong Yeon,Kang, Sung Yong,Jung, Taek Kyun,Lee, Hyo-Soo,Kim, Hyoun Woo American Scientific Publishers 2015 Journal of Nanoscience and Nanotechnology Vol.15 No.11

<P>In this paper, we detail improvements in the sensing properties of reduced graphene oxide (AGO), which were achieved through functionalization. The functionalization process utilizes graphene oxide suspensions, generating nanoparticles on the AGO surface mainly comprised of Ni(OH)(2) phase. Raman spectra indicate that functionalization increases the degree of disorder in RGOs. NO2 gas sensing tests reveal an approximate increase of 154% in the sensor response of the RGOs after functionalization. Possible mechanisms for improving sensing responses via functionalization are discussed. The enhancement is due to the spillover effect, to the increase of the sensor surface by the catalytic particles, to the reduction of AGO conduction volume through the generation of depletion region, and to the resistance modulation of the heterojunctions.</P>

Improvement of Gas Sensing Characteristics by Adding Pt Nanoparticles on ZnO-Branched SnO₂ Nanowires

Na, Han Gil,Kwon, Yong Jung,Cho, Hong Yeon,Kang, Sung Yong,Kim, Hyoun Woo American Scientific Publishers 2015 Journal of Nanoscience and Nanotechnology Vol.15 No.11

Morphological, microstructural, and photoluminescence characterization of heterogeneous/homogeneous TeO₂ nanostructures based on effect of different N₂ gas flow rates

Na, Han Gil,Jung, Taek-Kyun,Ryou, Min,Lee, Ji-Woon,Beck, Jihyun,Hyun, Soong-Keun,Choi, Myung Sik,Mirzaei, Ali,Choe, Kyeonghwan,Kim, Hyoun Woo,Jin, Changhyun ELSEVIER SCIENCE 2017 Journal of Alloys and Compounds Vol.695 No.-

<P><B>Abstract</B></P> <P>TeO<SUB>2</SUB> nanowires with diameters ranging from a few tens to hundreds of nanometers and lengths of a few tens of micrometers were prepared by thermal evaporation of Te powder with a Co catalyst. Initially, bead-like γ-TeO<SUB>2</SUB> nanoparticles on the surface of pre-formed thick TeO<SUB>2</SUB> nanowires were heterogeneously formed. Subsequently, uniform thin TeO<SUB>2</SUB> nanowires without the γ-TeO<SUB>2</SUB> phase were homogeneously synthesized by changing only the inlet N<SUB>2</SUB> gas flow rates and keeping other process parameters constant. The morphological and microstructural evolution of the two different nanomaterials was examined by X-ray diffraction, energy-dispersive X-ray spectrometry, and scanning and transmission electron microscopy. The optical properties of the nanomaterials were also investigated using photoluminescence spectroscopy. The emission peaks in the PL measurement without the supply of N<SUB>2</SUB> gas showed a synergetic effect between (1) bead-like orthorhombic γ-TeO<SUB>2</SUB> nanoparticles that show two specific emission bands at 388 nm and 590 nm; and (2) uniform tetragonal TeO<SUB>2</SUB> nanowires that show a characteristic emission band at 440 nm. In contrast, the pure tetragonal TeO<SUB>2</SUB> nanostructures synthesized under a N<SUB>2</SUB> gas flow rate of 2 standard liters per minute flow rate revealed a red-shifted emission band at 450 nm compared to heterogeneous structures of the same composition. The origins of the growth and emission mechanisms in the different TeO<SUB>2</SUB> structures are also discussed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The hybrid system of TeO<SUB>2</SUB>-based nanostructures was investigated. </LI> <LI> Two different TeO<SUB>2</SUB> properties may have originated from different gas flows. </LI> <LI> Morphological, microstructural, and optical transition was observed. </LI> </UL> </P>

Molecular group system as one energy unit

Na, Han Gil,Choi, Myung Sik,Bang, Jae Hoon,Oum, Wansik,Choi, Sun-Woo,Shim, Gyu Sam,Cho, Jae Hee,Kim, Hyoun Woo,Jin, Changhyun Elsevier 2019 CERAMICS INTERNATIONAL Vol.45 No.8

<P><B>Abstract</B></P> <P>In view of the various qualifications required of materials nowadays, efforts to change the characteristics of inherent materials have continued. However, most material conversion techniques that have been used in the past, such as alloy design and doping effect, cannot overcome the limitation that properties are only added to the original characteristics of pristine materials. Therefore, herein, we introduced a new material design technique, a so-called “Molecular Group System”, which is completely different from existing methods. Since whole-set-systems are considered one-energetic-unit-system, either only the merits of the constituent elements can be emphasized or new materials completely different from the raw ones can be synthesized. In this study, block-stacking bottom-up approach was employed to form a one group system from SnO<SUB>2</SUB>, SnO<SUB>x</SUB>, Sn, and graphene powders, and a binder, using high-energy irradiation. Then, we discussed theoretical verifications such as SnO<SUB>2</SUB>-reduction and Sn-channeling.</P>

Rhus verniciflua Stokes attenuates cholestatic liver cirrhosis-induced interstitial fibrosis via Smad3 down-regulation and Smad7 up-regulation

Mi Na Gil,Du Ri Choi,Kwang Sik Yu,Ji Heun Jeong,Dong Ho Bak,Do Kyung Kim,Nam Seob Lee,Je Hun Lee,Young Gil Jeong,Chun Soo Na,Dae Seung Na,Ki Hyun Ryu,Seung Yun Han 대한해부학회 2016 Anatomy & Cell Biology Vol.49 No.3

Cholestatic liver cirrhosis (CLC) eventually proceeds to end-stage liver failure by mediating overwhelming deposition of collagen, which is produced by activated interstitial myofibroblasts. Although the beneficial effects of Rhus verniciflua Stokes (RVS) on various diseases are well-known, its therapeutic effect and possible underlying mechanism on interstitial fibrosis associated with CLC are not elucidated. This study was designed to assess the protective effects of RVS and its possible underlying mechanisms in rat models of CLC established by bile duct ligation (BDL). We demonstrated that BDL markedly elevated the serological parameters such as aspartate aminotransferase, alanine transaminase, total bilirubin, and direct bilirubin, all of which were significantly attenuated by the daily uptake of RVS (2 mg/kg/day) for 28 days (14 days before and after operation) via intragastric route. We observed that BDL drastically induced the deterioration of liver histoarchitecture and excessive deposition of extracellular matrix (ECM), both of which were significantly attenuated by RVS. In addition, we revealed that RVS inhibited BDL-induced proliferation and activation of interstitial myofibroblasts, a highly suggestive cell type for ECM production, as shown by immunohistochemical and semi-quantitative detection of a-smooth muscle actin and vimentin. Finally, we demonstrated that the anti-fibrotic effect of RVS was associated with the inactivation of Smad3, the key downstream target of a major fibrogenic cytokine, i.e., transforming growth factor b (TGF-b). Simultaneously, we also found that RVS reciprocally increased the expression of Smad7, a negative regulatory protein of the TGF-b/Smad3 pathway. Taken together, these results suggested that RVS has a therapeutic effect on CLC, and these effects are, at least partly, due to the inhibition of liver fibrosis by the downregulation of Smad3 and upregulation of Smad7.

Analysis of the Cellular Stress Response in MCF10A Cells Exposed to Combined Radio Frequency Radiation

KIM, Han-Na,HAN, Na-Kyung,HONG, Mi-Na,CHI, Sung-Gil,LEE, Yun-Sil,KIM, Taehong,PACK, Jeong-Ki,CHOI, Hyung-Do,KIM, Nam,LEE, Jae-Seon Journal of Radiation Research Editorial Committee 2012 JOURNAL OF RADIATION RESEARCH Vol.53 No.2

<P>Exposure to environmental stressors can be measured by monitoring the cellular stress response in target cells. Here, we used the cellular stress response to investigate whether single or combined radio frequency (RF) radiation could induce stress response in human cells. Cellular stress responses in MCF10A human breast epithelial cells were characterized after exposure to 4 h of RF radiation [code division multiple access (CDMA) or CDMA plus wideband CDMA (WCDMA)] or 2 h RF radiation on 3 consecutive days. Specific absorption rate (SAR) was 4.0 W/kg for CDMA signal alone exposure and 2.0 W/kg each, 4.0 W/kg in total for combined CDMA plus WCDMA signals. Expression levels and phosphorylation states of specific heat shock proteins (HSPs) and mitogen-activated protein kinases (MAPKs) were analyzed by Western blot. It was found that HSP27 and ERK1/2 phosphorylations are the most sensitive markers of the stress response in MCF10A cells exposed to heat shock or ionizing radiation. Using these markers, we demonstrated that neither one-time nor repeated single (CDMA alone) or combined (CDMA plus WCDMA) RF radiation exposure significantly altered HSP27 and ERK1/2 phosphorylations in MCF10A cells (<I>p</I> > 0.05). The lack of a statistically significant alteration in HSP27 and ERK1/2 phosphorylations suggests that single or combined RF radiation exposure did not elicit activation of HSP27 and ERK1/2 in MCF10A cells.</P>