Investigation of Optical and Structural Stability of Localized Surface Plasmon Mediated Light‐Emitting Diodes by Ag and Ag/SiO₂ Nanoparticles

Jang, Lee&#x2010,Woon,Jeon, Dae&#x2010,Woo,Kim, Myoung,Jeon, Ju&#x2010,Won,Polyakov, Alexander Y.,Ju, Jin&#x2010,Woo,Lee, Seung&#x2010,Jae,Baek, Jong&#x2010,Hyeob,Yang, Jin&#x2010,Kyu,Lee, In&#x2010,H WILEY‐VCH Verlag 2012 Advanced functional materials Vol.22 No.13

<P><B>Abstract</B></P><P>Localized surface plasmon (LSP) effects due to Ag and Ag/SiO<SUB>2</SUB> nanoparticles (NPs) deposited on GaN/InGaN multiquantum well (MQW) light‐emitting diode (LED) structures are studied. The colloidal NPs are synthesized by a sol‐gel method and drop‐cased on the LED structures. The surface density of NPs its controlled by the concentration of the NP solution. Theoretical modeling is performed for the emission spectrum and the electric field distribution of LSP resonance for Ag/SiO<SUB>2</SUB> NPs. Enhanced photoluminescence (PL) efficiency is observed in the LED structures and the amount of PL enhancement increases with increasing the surface density of Ag and Ag/SiO<SUB>2</SUB> NPs. These effects are attributed to resonance coupling between the MQW and LSP in the NPs. It is also shown that the PL enhancement attainable with Ag NPs and Ag/SiO<SUB>2</SUB> NPs is comparable, but the latter displays a much higher stability with respect to long‐term storage and annealing due to a barrier for NP agglomeration, Ag oxidation, and impurity diffusion provided by the SiO<SUB>2</SUB> shell.</P>

Generation of anti‐tumour immune response using dendritic cells pulsed with carbonic anhydrase IX‐<i>Acinetobacter baumannii</i> outer membrane protein A fusion proteins against renal cell carcinoma

Kim, B.&#x2010,R.,Yang, E.&#x2010,K.,Kim, D.&#x2010,Y.,Kim, S.&#x2010,H.,Moon, D.&#x2010,C.,Lee, J.&#x2010,H.,Kim, H.&#x2010,J.,Lee, J.&#x2010,C. Blackwell Publishing Ltd 2012 Clinical and experimental immunology Vol.167 No.1

<P><B>Summary</B></P><P>Carbonic anhydrase IX (CA9), a specific molecular marker for renal cell carcinoma (RCC), serves as a potential target for RCC‐specific immunotherapy using dendritic cells (DCs). However, pulsing of DCs with CA9 alone is not sufficient for generation of a therapeutic anti‐tumour immune response against RCC. In this study, in order to generate a potent anti‐tumour immune response against RCC, we produced recombinant CA9‐<I>Acinetobacter baumannii</I> outer membrane protein A (AbOmpA) fusion proteins, designated CA9‐AbOmpA, and investigated the ability of DCs pulsed with CA9‐AbOmpA fusion proteins in a murine renal cell carcinoma (RENCA) model. A recombinant CA9‐AbOmpA fusion protein was composed of a unique proteoglycan‐related region of CA9 (1–120 amino acids) fused at the C‐terminus with transmembrane domain of AbOmpA (1–200 amino acids). This fusion protein was capable of inducing DC maturation and interleukin (IL)‐12 production in DCs. Interaction of DCs pulsed with CA9‐AbOmpA fusion proteins with naive T cells stimulated secretion of IL‐2, interferon (IFN)‐γ and tumour necrosis factor (TNF)‐α in T cells. Lymphocytes harvested from mice immunized with DCs pulsed with CA9‐AbOmpA fusion proteins secreted IFN‐γ and showed a specific cytotoxic activity against CA9‐expressing RENCA (RENCA‐CA9) cells. Administration of CA9‐AbOmpA‐pulsed DC vaccine suppressed growth of RENCA‐CA9 cells in mice with an established tumour burden. These results suggest that DCs pulsed with CA9‐AbOmpA fusion proteins generate a specific anti‐tumour immune response against RCC, which can be utilized in immunotherapy of RCC.</P>

A search for synthetic peptides that inhibit soluble <i>N</i>‐ethylmaleimide sensitive‐factor attachment receptor‐mediated membrane fusion

Jung, Chang H.,Yang, Yoo&#x2010,Soo,Kim, Jun&#x2010,Seob,Shin, Jae&#x2010,Il,Jin, Yong&#x2010,Su,Shin, Jae Y.,Lee, Jong H.,Chung, Koo M.,Hwang, Jae S.,Oh, Jung M.,Shin, Yeon&#x2010,Kyun,Kweon, Dae&#x2 Blackwell Publishing Ltd 2008 FEBS JOURNAL Vol.275 No.12

<P>Soluble <I>N</I>‐ethylmaleimide sensitive‐factor attachment receptor (SNARE) proteins have crucial roles in driving exocytic membrane fusion. Molecular recognition between vesicle‐associated (v)‐SNARE and target membrane (t)‐SNARE leads to the formation of a four‐helix bundle, which facilitates the merging of two apposing membranes. Synthetic peptides patterned after the SNARE motifs are predicted to block SNARE complex formation by competing with the parental SNAREs, inhibiting neuronal exocytosis. As an initial attempt to identify the peptide sequences that block SNARE assembly and membrane fusion, we created thirteen 17‐residue synthetic peptides derived from the SNARE motifs of v‐ and t‐SNAREs. The effects of these peptides on SNARE‐mediated membrane fusion were investigated using an <I>in vitro</I> lipid‐mixing assay, <I>in vivo</I> neurotransmitter release and SNARE complex formation assays in PC12 cells. Peptides derived from the N‐terminal region of SNARE motifs had significant inhibitory effects on neuroexocytosis, whereas middle‐ and C‐terminal‐mimicking peptides did not exhibit much inhibitory function. N‐terminal mimicking peptides blocked N‐terminal zippering of SNAREs, a rate‐limiting step in SNARE‐driven membrane fusion. Therefore, the results suggest that the N‐terminal regions of SNARE motifs are excellent targets for the development of drugs to block SNARE‐mediated membrane fusion and neurotransmitter release.</P>

Soluble c‐Met protein as a susceptible biomarker for gastric cancer risk: A nested case‐control study within the Korean Multicenter Cancer Cohort

Yang, Jae Jeong,Yang, Ji Hyun,Kim, Jungkon,Ma, Seung Hyun,Cho, Lisa Y.,Ko, Kwang&#x2010,Pil,Shin, Aesun,Choi, Bo Youl,Kim, Hyun Ja,Han, Dong Soo,Eun, Chang Soo,Song, Kyu Sang,Kim, Yong Sung,Chang, Sou Wiley Subscription Services, Inc., A Wiley Company 2013 International journal of cancer: Journal internati Vol.132 No.9

<P><B>Abstract</B></P><P>This study was conducted to evaluate the relevance of the soluble form of c‐Met protein, a truncated form of the c‐Met membrane receptor involved in the CagA pathway, as a potential biomarker for gastric cancer. Among 290 gastric cancer case‐control sets selected from the Korean Multicenter Cancer Cohort, the plasma concentrations of soluble c‐Met protein were measured with enzyme‐linked immunosorbent assays. Using analysis of variance and covariance models with age, sex, smoking, <I>Helicobacter pylori</I> infection, and CagA seropositivity, the mean concentrations of soluble c‐Met protein between cases and controls were compared. To evaluate the association between gastric cancer and a c‐Met protein level, odds ratios and 95% confidence intervals were estimated using conditional logistic regression models. Interactions between CagA‐related genes and the soluble c‐Met protein concentration were also investigated. The overall median plasma concentration of soluble c‐Met among cases was significantly lower than those of controls (1.390 <I>vs</I>. 1.610 ng/mL, <I>p</I> < 0.0001). Closer to the onset of gastric cancer, the soluble c‐Met protein level decreased linearly in a time‐dependent manner (<I>p</I> for trend = 0.0002). The combined effects between the CagA‐related genes and the soluble c‐Met protein concentration significantly intensified risks for gastric cancer. Restricted analyses including cases that had been diagnosed within 1 year after entering the cohort had a fair degree of ability (area under the receiver operating characteristic curve of 0.73–0.77) to discriminate gastric cancer cases from normal controls. Our findings demonstrate the potential of the soluble form of c‐Met protein as a novel biomarker for gastric cancer. The beneficial effects of a high soluble c‐Met concentration in human plasma are strongly supported.</P>

Salt‐resistant homodimeric bactenecin, a cathelicidin‐derived antimicrobial peptide

Lee, Ju Y.,Yang, Sung&#x2010,Tae,Lee, Seung K.,Jung, Hyun H.,Shin, Song Y.,Hahm, Kyung&#x2010,Soo,Kim, Jae I. Blackwell Publishing Ltd 2008 The FEBS journal Vol.275 No.15

<P>The cathelicidin antimicrobial peptide bactenecin is a β‐hairpin molecule with a single disulfide bond and broad antimicrobial activity. The proform of bactenecin exists as a dimer, however, and it has been proposed that bactenecin is released as a dimer <I>in vivo</I>, although there has been little study of the dimeric form of bactenecin. To investigate the effect of bactenecin dimerization on its biological activity, we characterized the dimer’s effect on phospholipid membranes, the kinetics of its bactericidal activity, and its salt sensitivity. We initially synthesized two bactenecin dimers (antiparallel and parallel) and two monomers (β‐hairpin and linear). Under oxidative folding conditions, reduced linear bactenecin preferentially folded into a dimer forming a ladder‐like structure via intermolecular disulfide bonding. As compared to the monomer, the dimer had a greater ability to induce lysis of lipid bilayers and was more rapidly bactericidal. Interestingly, the dimer retained antimicrobial activity at physiological salt concentrations (150 m<SMALL>m</SMALL> NaCl), although the monomer was inactivated. This salt resistance was also seen with bactenecin dimer containing one intermolecular disulfide bond, and the bactenecin dimer appears to undergo multimeric oligomerization at high salt concentrations. Overall, dimeric bactenecin shows potent and rapid antimicrobial activity, and resists salt‐induced inactivation under physiological conditions through condensation and oligomerization. These characteristics shed light on the features that a peptide would need to serve as an effective therapeutic agent.</P>

Apoptosis‐inducing effect of diketopiperazine disulfides produced by <i>Aspergillus</i> sp. KMD 901 isolated from marine sediment on HCT116 colon cancer cell lines

Choi, E.J.,Park, J.&#x2010,S.,Kim, Y.&#x2010,J.,Jung, J.&#x2010,H.,Lee, J.K.,Kwon, H.C.,Yang, H.O. Blackwell Publishing Ltd 2011 Journal of applied microbiology Vol.110 No.1

<P><B>Abstract</B></P><P><B>Aims: </B> Research is to identify the bioactive secondary metabolites produced by <I>Aspergillus</I> sp. KMD 901 isolated from marine sediment and to assess their apoptosis‐inducing effects.</P><P><B>Methods and Results: </B> <I>Aspergillus</I> sp. KMD 901 was isolated from marine sediment obtained from the East Sea of Korea. An ethyl acetate extract of KMD 901 exhibited potent cytotoxic activity towards five cancer cell lines (HCT116, AGS, A549, MCF‐7 and HepG2). Sequencing of the internal transcribed spacer (ITS) region in this strain allowed us to identify KMD 901 as a strain of <I>Aspergillus versicolor</I>. The cytotoxic compounds from <I>Aspergillus</I> sp. KMD 901 were purified by reversed‐phase high‐performance liquid chromatography and identified as diketopiperazine disulfides through spectroscopic analyses including extensive 2D NMR and mass spectrometry. The diketopiperazine disulfides were found to induce apoptosis in HCT116 cells based on cell morphology, DNA fragmentation observed by agarose gel electrophoresis, Annexin‐V/PI staining using a flow cytometer and cleavage of poly (ADP‐ribose) polymerase (PARP), caspase‐3, caspase‐8, caspase‐9 and Bcl‐2 family proteins (Bcl‐2, Bcl‐xL and Bax) using Western blotting analysis. Further study using an <I>in vivo</I> xenograft model showed inhibitory effects of acetylapoaranotin (<B>2</B>) on tumour proliferation.</P><P><B>Conclusion: </B> A new diketopiperazine disulfide, deoxyapoaranotin (<B>3</B>), along with previously described acetylaranotin (<B>1</B>) and acetylapoaranotin (<B>2</B>) was separated from <I>Aspergillus</I> sp. KMD 901 and found to have direct cytotoxic and apoptosis‐inducing effects towards HCT116 colon cancer cell lines.</P><P><B>Significance and Impact of the Study: </B> These results suggest that the diketopiperazine disulfides produced from <I>Aspergillus</I> sp., KMD 901, could be candidates for the development of apoptosis‐inducing antitumour agents. Also, this study indicates that marine natural products as potential source of pharmaceuticals.</P>

Preparation, surface characteristic and photoactive activitiesof Ni₂FeV₃O₁₁ semiconductor nanoparticles

Qiao, X.,Yang, L.,Li, Y.,Wan, Y.,Huang, Y.,Cheng, H.,Seo, H.J. North-Holland 2016 Materials letters Vol.163 No.-

Ni<SUB>2</SUB>FeV<SUB>3</SUB>O<SUB>11</SUB> nanorods were prepared by the sol-gel method via film-coating and subsequent heating. The sample was conducted by the crystal structure refinement confirming a pure triclinic phase with space group P-1. The surface characteristics were investigated by the measurements such as scanning electron microscope (SEM), transmission electron microscopy (TEM), specific surface area, and energy-dispersive X-ray spectroscopy (EDX). The photo-physical properties of Ni<SUB>2</SUB>FeV<SUB>3</SUB>O<SUB>11</SUB> nanorods were measured by the UV-vis absorption spectrum, and the photodegradation for methylene blue solutions (MB). This vanadate semiconductor has band-gap energy of 1.85eV and presents an efficient photocatalytic activity driven by visible-light. Moreover, the nanorods are magnetically recoverable after the photocatalysis.

Effect of warfarin withdrawal on thrombolytic treatment in patients with ischaemic stroke

Kim, Y. D.,Lee, J. H.,Jung, Y. H.,Cha, M.&#x2010,J.,Choi, H. Y.,Nam, C. M.,Yang, J. H.,Cho, H. J.,Nam, H. S.,Lee, K.&#x2010,Y.,Heo, J. H. Blackwell Publishing Ltd 2011 European Journal of Neurology Vol.18 No.9

<P><B>Background and purpose: </B> Abruptly discontinuing warfarin may induce a rebound prothrombotic state. Thrombolytic agents may also paradoxically induce prothrombotic conditions, which include platelet activation and thrombin generation. Therefore, prothrombotic states may be enhanced by withdrawing warfarin in patients under thrombolytic treatment. This study was aimed to determine whether patients with warfarin withdrawal have different clinical outcomes from those without warfarin use after thrombolytic treatment.</P><P><B>Methods: </B> A total of 148 consecutive patients with atrial fibrillation who were not on anticoagulants at admission and who received thrombolysis were included in this study. We compared the outcomes between a warfarin withdrawal group and a no‐warfarin group.</P><P><B>Results: </B> Fourteen patients (9.5%) were included in the warfarin withdrawal group. Although baseline National Institute of Health Stroke Scale (NIHSS) scores, recanalization rates, and hemorrhage frequencies did not differ between the groups, the warfarin withdrawal group showed poorer outcomes. Increased NIHSS scores during the first 7 days were more frequent in the warfarin withdrawal group (57.1% vs. 26.9%, <I>P</I> = 0.029). The median percent improvement in NIHSS scores at 24 h after thrombolysis was also lower in the warfarin withdrawal group. After adjusting for covariates, warfarin withdrawal was a strong predictor of poor functional outcome at 3 months (modified Rankin score ≥ 3) (odds ratio, 17.067, 95% CI 2.703–107.748).</P><P><B>Conclusions: </B> Discontinuing warfarin was associated with early neurologic deterioration and poor long‐term outcomes after thrombolytic treatment.</P>

Phenological growth stages of <i>Brachypodium distachyon</i>: codification and description

HONG, S&#x2010,Y,PARK, J&#x2010,H,CHO, S&#x2010,H,YANG, M&#x2010,S,PARK, C&#x2010,M Blackwell Publishing Ltd 2011 Weed research Vol.51 No.6

<P>H<SMALL>ong</SMALL> S‐Y, P<SMALL>ark</SMALL> J‐H, C<SMALL>ho</SMALL> S‐H, Y<SMALL>ang</SMALL> M‐S & P<SMALL>ark</SMALL> C‐M (2011). Phenological growth stages of <I>Brachypodium distachyon</I>: codification and description. <I>Weed Research</I><B>51</B>, 612–620.</P><P><B>Summary</B></P><P><I>Brachypodium distachyon</I> is being used as a new model monocotyledon for grass crop research and bioenergy grass biotechnology. With the recent completion of the full genome sequencing project, one of the next major challenges is to determine the functional activities of many genes. In an attempt to aid the rapid determination of gene function in crop plants, a high throughput phenotypic analysis system has been established through phenological analyses of a series of defined growth stages. The codification follows the BBCH (Biologische Bundesantalt, Bundessortenamt and CHemische Industrie) scale, a numerical system that differentiates between principal and secondary growth stages from seed germination to flower head emergence and seed ripening. We present here analyses of the phenological development stages of <I>B.?distachyon</I> to illustrate a methodological framework that can be used to identify and interpret phenotypic differences derived from genetic variations and environmental stress responses in this plant species. This scale may greatly contribute to the <I>B.?distachyon</I> research in the future, particularly to functional determination of genes that mediate biomass productivity. It may also serve as a suitable tool for defining the growth stages of other grass species.</P>

A dermal equivalent can be developed from fibroblast culture by means of a high concentration of serum

Lee, D.&#x2010,Y.,Yang, J.&#x2010,M.,Baek, M.&#x2010,K. Blackwell Publishing Ltd 2011 British journal of dermatology Vol.164 No.5