Fabrication of (001)-oriented monoclinic WO3 films on FTO substrates.

Zheng, Jin You,Song, Guang,Kim, Chang Woo,Kang, Young Soo RSC Pub 2013 Nanoscale Vol.5 No.12

<P>(001)-oriented monoclinic nanorod and microplate WO3 films are fabricated on commercial FTO-coated glass substrates by a rubbing seed layer and a spin-coating seed layer assisted by hydrothermal reactions. The nanorod film obtained by the rubbing seed layer assisted by hydrothermal reactions is more regular and perpendicular to the substrate.</P>

Highly enhancing photoelectrochemical performance of facilely-fabricated Bi-induced (002)-oriented WO₃ film with intermittent short-time negative polarization

Zheng, Jin You,Pawar, Amol Uttam,Kim, Chang Woo,Kim, Yong Joo,Kang, Young Soo Elsevier 2018 Applied catalysis. B, Environmental Vol.233 No.-

<P><B>Abstract</B></P> <P>WO<SUB>3</SUB> photoelectrode should have high photoactivity and stability for application in solar water splitting. By introducing Bi<SUP>3+</SUP> ions, a highly ordered (002)-oriented WO<SUB>3</SUB> film with a high photocurrent was easily prepared on FTO glass by spin coating a simple Bi-doped peroxotungstic acid (PTA) gel followed by calcination. In situ XRD, pole figures, and HR-TEM were performed to elucidate the formation process and epitaxial properties. The flat Bi-WO<SUB>3</SUB> film achieved a remarkable photocurrent density of 2.06 mA cm<SUP>−2</SUP> at 1.5 V vs. Ag/AgCl. By introducing intermittent short-time negative polarization (ISNP) into the process of PEC water splitting, the O<SUB>2</SUB> gas product yield is enhanced by ca. 75% with high faradaic efficiency, as ISNP can efficiently eliminate peroxo species on the surface of the WO<SUB>3</SUB> film. This demonstrates that ISNP can enhance the photostability and photoactivity of WO<SUB>3</SUB> films.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Stable Bi-doped peroxotungstic acid gel is prepared without any organic stabilizer. </LI> <LI> (002)-oriented Bi-doped WO<SUB>3</SUB> films is easily fabricated on FTO by spin-coating technique. </LI> <LI> The Bi-WO<SUB>3</SUB> film exhibits remarkable photoelectrochemical properties. </LI> <LI> Intermittent short-time negative polarization enhances the photostability and photoactivity of the Bi-WO<SUB>3</SUB> film. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Facile Fabrication of WO₃ Nanoplates Thin Films with Dominant Crystal Facet of (002) for Water Splitting

Zheng, Jin You,Song, Guang,Hong, Jisang,Van, Thanh Khue,Pawar, Amol Uttam,Kim, Do Yoon,Kim, Chang Woo,Haider, Zeeshan,Kang, Young Soo American Chemical Society 2014 Crystal Growth & Design Vol.14 No.11

<P>Single crystalline orthorhombic phase tungsten trioxide monohydrate (<I>O</I>-WO<SUB>3</SUB>·H<SUB>2</SUB>O, space group: <I>Pmnb</I>) nanoplates with a clear morphology and uniform size distribution have been synthesized by the hydrothermal method and fabricated on the surface of fluorine doped tin oxide (FTO) coated glass substrates with selective exposure of the crystal facet by the finger rubbing method. The rubbing method can easily arrange the <I>O</I>-WO<SUB>3</SUB>·H<SUB>2</SUB>O nanoplates along the (020) facet on the FTO substrate. The <I>O</I>-WO<SUB>3</SUB>·H<SUB>2</SUB>O nanoplate can be converted to monoclinic phase WO<SUB>3</SUB> (γ-WO<SUB>3</SUB>, space group: <I>P</I>21/<I>n</I>) with dominant crystal facet of (002) without destroying the plate structure. Crystal morphologies, structures, and components of the powders and films have been determined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman, X-ray photoelectron spectroscopy, etc. The band gap energies of the <I>O</I>-WO<SUB>3</SUB>·H<SUB>2</SUB>O and γ-WO<SUB>3</SUB> nanoplates were determined as ca. 2.26 and 2.49 eV, respectively. Photoelectrochemical properties of the films with (002) dominant crystal facet have also been checked for discussion of further application in water oxidation. The advantage of (002) facet dominant film was investigated by comparing to one spin-coated γ-WO<SUB>3</SUB> thin film with the same thickness via photoelectrochemical characterizations such as photocurrent, incident photon to current efficiency, and electrochemical impedance spectroscopy.</P><P>Single crystalline orthorhombic phase <I>O</I>-WO<SUB>3</SUB>·H<SUB>2</SUB>O nanoplates with clear morphology and uniform size distribution have been synthesized by the hydrothermal method and fabricated as (020)-oriented film by the finger rubbing method. The (020)-oriented <I>O</I>-WO<SUB>3</SUB>·H<SUB>2</SUB>O film can be converted to monoclinic phase (002)-oriented γ-WO<SUB>3</SUB> film by calcination. Photoelectrochemical properties have been examined for further application in solar water oxidation.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cgdefu/2014/cgdefu.2014.14.issue-11/cg5012154/production/images/medium/cg-2014-012154_0016.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cg5012154'>ACS Electronic Supporting Info</A></P>

Vertical cobalt dendrite array films: electrochemical deposition and characterization, glucose oxidation and magnetic properties

Zheng, Jin You,Quan, Zhen Lan,Song, Guang,Kim, Chang Woo,Cha, Hyun Gil,Kim, Tae Wan,Shin, Woonsup,Lee, Kyu Joon,Jung, Myung Hwa,Kang, Young Soo The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.24

<P>Vertically and laterally oriented cobalt dendrite films with or without dendritic structures were synthesized by cathodic electrodeposition under different experimental conditions. The morphology of Co deposits was varied significantly depending on deposition conditions such as applied potential, precursor concentration and especially pH value. Co dendritic crystal growth along the [110] direction is preferred. The possible growth mechanism is discussed by supposing differing concentration areas. Results of glucose electrooxidation demonstrate that vertical Co dendrite films are promising materials as carbohydrate sensors with high sensitivity and fast response. In addition, magnetic measurements on cobalt samples under parallel and perpendicular direction of the applied magnetic field show that they exhibit a ferromagnetic behavior with different saturation magnetizations and coercivities.</P> <P>Graphic Abstract</P><P>Vertically and laterally oriented ferromagnetic cobalt films with or without dendritic structures were synthesized by electrodeposition under different deposition conditions (NF: nanoflowers, NS: nanosheets). <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2jm30300k'> </P>

Glutathione Conjugates of 2- or 6-Substituted 5,8-Dimethoxy-1,4-Naphthoquinone Derivatives : Formation and Structure

Zheng, Xiang-Guo,Kang, Jong-Seong,Kim, Yong,You, Young-Jae,Jin, Guang-Zhu,Ahn, Byung-Zun The Pharmaceutical Society of Korea 1999 Archives of Pharmacal Research Vol.22 No.4

Thirty-four glutathione conjugates of 5,8-dimethoxy-1,4-naphthoquinones (DMNQ) were synthesized and their structure was determined. The yield of GSH conjugate was dependent on size of alkyl group; the longer the size of alkyl group was, the lower was the yield. It was also found that the length of alkyl side chain influenced the chemical shift of quinonoid protons; the quinonoid protons of 2-glutathionyl DMNQ derivatives with R=H to propyl, 6.51-6.59 ppm vs. other ones with R=butyl to heptyl, 6.64-6.68 ppm. this was explained to be due to a folding effect of longer alkyl group. Glutathione (GSH) reacted with DMNQ derivative first to form a 1,4-adduct (2- or 3-glutathionyl-1,4-dihydroxy-5,8-dimethoxynaphthalenes) and then the adduct was autooxidized to 2- or 3-glutathionyl-DMNQ derivatives. Moreover, GSH reduced DMNQ derivatives to their hydrogenated products. It was suggested that such an organic reaction might play an important role for a study of metabolism or toxicity of DMNQ derivative sin the living cells.

Characteristics of Mammary Paget's Disease in China: a National-wide Multicenter Retrospective Study During 1999-2008

Zheng, Shan,Song, Qing-Kun,Zhao, Lin,Huang, Rong,Sun, Li,Li, Jing,Fan, Jin-Hu,Zhang, Bao-Ning,Yang, Hong-Jian,Xu, Feng,Zhang, Bin,Qiao, You-Lin Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

The aim of this study was to detail characteristics of mammary Paget's disease (PD) representing the whole population in China. A total of 4211 female breast cancer inpatients at seven tertiary hospitals from seven representative geographical regions of China were collected randomly during 1999 to 2008. Data for demography, risk factors, diagnostic imaging test, physical examination and pathologic characters were surveyed and biomarker status was tested by immunohistochemistry. The differences of demography and risk factors between PD with breast cancer and other lesions were compared using Chi-square test or t-test, with attention to physical examination and pathological characters. The percentage of PD was 1.6% (68/4211) in all breast cancers. The mean age at diagnosis was 48.1, and 63.2% (43/68) patients were premenopausal. There is no difference in demography and risk factors between PD with breast cancer and other breast cancer (P > 0.05). The main pattern of PD in physical exam and pathologic pattern were patients presenting with a palpable mass in breast (65/68, 95.6%) and PD with underlying invasive cancer (82.4%, 56/68) respectively. The rate of multifocal disease was 7.4% (5/68). PD with invasive breast cancer showed larger tumor size, more multifocal disease, lower ER and PR expression and higher HER2 overexpression than those in other invasive breast cancer (P < 0.05). These results suggested that PD in China is a concomitant disease of breast cancer, and that PD with underlying invasive cancer has more multiple foci and more aggressive behavior compared with other breast invasive cancer. We address the urgent needs for establishing diagnostic and therapeutic guidelines for mammary PD in China.

<i>Pseudomonas aeruginosa</i> Eliminates Natural Killer Cells via Phagocytosis-Induced Apoptosis

Chung, Jin Woong,Piao, Zheng-Hao,Yoon, Suk Ran,Kim, Mi Sun,Jeong, Mira,Lee, Suk Hyung,Min, Jeong Ki,Kim, Jae Wha,Cho, You-Hee,Kim, Jin Chul,Ahn, Jeong Keun,Kim, Kyoon Eon,Choi, Inpyo Public Library of Science 2009 PLoS pathogens Vol.5 No.8

<▼1><P><I>Pseudomonas aeruginosa</I> (PA) is an opportunistic pathogen that causes the relapse of illness in immunocompromised patients, leading to prolonged hospitalization, increased medical expense, and death. In this report, we show that PA invades natural killer (NK) cells and induces phagocytosis-induced cell death (PICD) of lymphocytes. <I>In vivo</I> tumor metastasis was augmented by PA infection, with a significant reduction in NK cell number. Adoptive transfer of NK cells mitigated PA-induced metastasis. Internalization of PA into NK cells was observed by transmission electron microscopy. In addition, PA invaded NK cells via phosphoinositide 3-kinase (PI3K) activation, and the phagocytic event led to caspase 9-dependent apoptosis of NK cells. PA-mediated NK cell apoptosis was dependent on activation of mitogen-activated protein (MAP) kinase and the generation of reactive oxygen species (ROS). These data suggest that the phagocytosis of PA by NK cells is a critical event that affects the relapse of diseases in immunocompromised patients, such as those with cancer, and provides important insights into the interactions between PA and NK cells.</P></▼1><▼2><P><B>Author Summary</B></P><P>Phagocytic leukocytes, including neutrophils and macrophages, are critical for innate immunity against invading bacteria. Binding and internalization of bacteria by these immune cells stimulates a variety of anti-microbial activities. Although the immune cells are specialized for elimination of bacteria, cellular apoptosis by bacterial phagocytosis has emerged as an important mechanism of pathogenesis. NK cells are non-phagocytic lymphocytes that are responsible for innate immunity via elimination of virus or bacteria-infected cells, as well as transformed cells. We found that PA invades NK cells and that this phagocytic event results in the generation of ROS within the NK cells, leading to apoptosis. The elimination of NK cells, at least in part, may be responsible for the relapse in PA-infected cancer patients. Based on these findings, studies on the interactions between bacterial determinants and host receptors should provide further insight into the mechanisms of bacterial pathogenesis.</P></▼2>

Surfactant free fabrication and improved charge carrier separation induced enhanced photocatalytic activity of {001} facet exposed unique octagonal BiOCl nanosheets

Haider, Zeeshan,Zheng, Jin You,Kang, Young Soo The Royal Society of Chemistry 2016 Physical chemistry chemical physics Vol.18 No.29

<P>Unique octagonal shaped BiOCl nanosheets (NS) dominantly exposed with high energy {001} crystal facets have been fabricated via a simple hydrothermal route without using organic surfactants. The dynamics of photogenerated charge carriers have been studied by time-resolved photoluminescence spectroscopy. The fitting parameters of the decay kinetics were used to calculate both the intensity weighted average lifetime (<tau >(int.)), as well as the amplitude weighted average lifetime (<tau >(amp.)) of the photogenerated charge carriers. The <tau >(int.) and <tau >(amp.) values for {001} BiOCl NS, i.e., 17.23 ns and 1.94 ns, respectively, were observed to be significantly higher than the corresponding values obtained for pristine BiOCl such as 2.52 ns and 1.07 ns, respectively. Significant quenching of the PL emission intensity of {001} BiOCl NS reflected the enhanced separation of the photogenerated charge carriers. Reduced thickness and in situ iodine doping was favorable to minimize the recombination tendency. The photocatalytic activity was monitored via the photodegradation of RhB under visible light illumination (lambda > 400 nm). {001} BiOCl NS exhibited superior performance when compared to pristine BiOCl in terms of the rapid degradation kinetics and higher photonic efficiency. The photocatalytic efficiency of {001} BiOCl NS was 2.8 times higher than pristine BiOCl. Iodine doping induced extended the optical absorption in the visible region and improved the separation of the photogenerated charge carriers, which played an important role to enhance the photocatalytic activity. The photodegradation mechanism was systematically studied using various radical quenchers and it was revealed that photogenerated holes (h(+)) and superoxide radicals (O-center dot(2-)) actively participated whereas hydroxyl (OH center dot) radicals had a negligible contribution in the photodegradation of RhB. {001} BiOCl NS has shown a higher photocurrent density and lower charge transfer resistance analyzed through photoelectrochemical and electrochemical impedance measurements. This study highlights the fabrication of unique octagonal BiOCl NS with improved separation of charge carriers across high energy crystal facts to design a highly efficient photocatalyst.</P>

Selective construction of junctions on different facets of BiVO₄ for enhancing photo-activity

Wang, Peng,Zheng, Jin You,Zhang, Dun,Kang, Young Soo The Royal Society of Chemistry 2015 NEW JOURNAL OF CHEMISTRY Vol.39 No.12

<P>A novel ternary Ag/BiVO<SUB>4</SUB>/Co<SUB>3</SUB>O<SUB>4</SUB> hybrid photocatalyst was designed by constructing a metal–semiconductor junction and a p–n junction on electron-rich {010} facets and hole-rich {110} facets of BiVO<SUB>4</SUB>, respectively. The Ag/BiVO<SUB>4</SUB>/Co<SUB>3</SUB>O<SUB>4</SUB> hybrid photocatalyst exhibits enhanced photocatalytic activity for rhodamine B degradation, which is over 8 times that of bare BiVO<SUB>4</SUB> under simulated solar light. It was proven that the combination of a metal–semiconductor junction and a p–n junction further promotes the charge transferring across the interface, and results in an additional effect of two single junctions for improving photo-activity. This research provides a deep insight about the co-working mechanism between the two heterojunctions, and it will propose a new concept for designing a highly efficient photo-catalyst system.</P> <P>Graphic Abstract</P><P>The combination of p–n and m–s junctions over BiVO<SUB>4</SUB> results in an additional effect for improving photo-activity. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c5nj01836f'> </P>

Production of Monoclonal Antibody Against Listeria monocytogenes and Its Application to Immunochromatography Strip Test

( Won Bo Shim ),( Jin Gil Choi ),( Ji Young Kim ),( Zheng You Yang ),( Kyu Ho Lee ),( Min Gon Kim ),( Sang Do Ha ),( Keun Sung Kim ),( Kwang Yup Kim ),( Cheol Ho Kim ),( Kwang Soo Ha ),( Sergei A. Ere 한국미생물생명공학회 2007 Journal of microbiology and biotechnology Vol.17 No.7