B-containing nanomaterial synthesis when a combustion wave moves within a packed bed of solid particles

Nersisyan, H.,Lee, T.H.,Yoo, B.U.,Kwon, S.C.,Suh, H.,Kim, J.G.,Lee, J.H. Elsevier [etc.] 2016 Combustion and Flame Vol.172 No.-

This study deals with combustion behavior of B<SUB>2</SUB>O<SUB>3</SUB>/Mg/NH<SUB>4</SUB>Cl/C complex systems for the synthesis of amorphous boron (B), boron carbide (B<SUB>4</SUB>C), and boron nitride (BN) nanostructures. The raw mixtures used in the experiments were prepared on the base of a B<SUB>2</SUB>O<SUB>3</SUB>-Mg precursor mixture, which is sufficiently exothermic to maintain a self-propagating regime of the combustion reaction. Thermodynamic analysis of the combustion temperatures and experimental validation indicate that the 1000-1500<SUP>o</SUP>C temperature range is very effective for synthesizing the nanostructures of B, B<SUB>4</SUB>C, and BN. It was found that B-containing functional nanostructures are mainly spherical nanoparticles (B) or nanosheets (B<SUB>4</SUB>C, BN). The phase composition and microstructural characteristics of the final products were evaluated based on the combustion temperature and solid/liquid phase changes.

The inability of Bacillus licheniformis perR mutant to grow is mainly due to the lack of PerR-mediated fur repression

Kim, J. H.,Yang, Y. M.,Ji, C. J.,Ryu, S. H.,Won, Y. B.,Ju, S. Y.,Kwon, Y.,Lee, Y. E.,Youn, H.,Lee, J. W. MICROBIOLOGICAL SOCIETY OF KOREA 2017 JOURNAL OF MICROBIOLOGY -SEOUL- Vol. No.

<P>PerR, a member of Fur family protein, is a metal-dependent H2O2 sensing transcription factor that regulates genes involved in peroxide stress response. Industrially important bacterium Bacillus licheniformis contains three PerR-like proteins (PerR(BL), PerR2, and PerR3) compared to its close relative Bacillus subtilis. Interestingly, unlike other bacteria including B. subtilis, no authentic perR (BL) null mutant could be established for B. licheniformis. Thus, we constructed a conditional perR (BL) mutant using a xylose-inducible promoter, and investigated the genes under the control of PerR(BL). PerR(BL) regulon genes include katA, mrgA, ahpC, pfeT, hemA, fur, and perR as observed for PerR(BS). However, there is some variation in the expression levels of fur and hemA genes between B. subtilis and B. licheniformis in the derepressed state. Furthermore, katA, mrgA, and ahpC are strongly induced, whereas the others are only weakly or not induced by H2O2 treatment. In contrast to the B. subtilis perR null mutant which frequently gives rise to large colony phenotype mainly due to the loss of katA, the suppressors of B. licheniformis perR mutant, which can form colonies on LB agar, were all catalase-positive. Instead, many of the suppressors showed increased levels of siderophore production, suggesting that the suppressor mutation is linked to the fur gene. Consistent with this, perR fur double mutant could grow on LB agar without Fe supplementation, whereas perR katA double mutant could only grow on LB agar with Fe supplementation. Taken together, our data suggest that in B. licheniformis, despite the similarity in PerR(BL) and PerR(BS) regulon genes, perR is an essential gene required for growth and that the inability of perR null mutant to grow is mainly due to elevated expression of Fur.</P>

Efficacy of HVT-IBD vector vaccine compared to attenuated live vaccine using in-ovo vaccination against a Korean very virulent IBDV in commercial broiler chickens

Roh, J.-H.,Kang, M.,Wei, B.,Yoon, R.-H.,Seo, H.-S.,Bahng, J.-Y.,Kwon, J.-T.,Cha, S.-Y.,Jang, H.-K. Elsevier 2016 Poultry science Vol.95 No.5

<P>The production performance, efficacy, and safety of two types of vaccines for infectious bursal disease virus (IBDV) were compared with in-ovo vaccination of Cobb 500 broiler chickens for gross and microscopic examination of the bursa of Fabricius, bursa/body weight (b/B) ratio, flow cytometry, and serologic response to Newcastle disease virus (NDV) vaccination. One vaccine was a recombinant HVT-IBD vector vaccine (HVT as for herpesvirus of turkeys) and the other was an intermediate plus live IBDV vaccine. A significant difference was detected at 21 d. Eight of 10 chickens that received the IBDV live vaccine had severe bursal lesions and a relatively low b/B ratio of 0.95, and an inhibited NDV vaccine response. On the other hand, the HVT-IBD vector vaccine resulted in mild bursal lesions and a b/B ratio of 1.89. Therefore, the live vaccine had lower safety than that of the HVT-IBD vector vaccine. To determine the protective efficacy, chickens were intraocularly challenged at 24 d. Eight of 10 chickens in the IBDV live vaccination group showed gross and histological lesions characterized by hemorrhage, cyst formation, lymphocytic depletion, and a decreased b/B ratio. In contrast, the HVT-IBD vector vaccinated chickens showed mild gross and histological lesions in three of 10 chickens with a b/B ratio of 1.36, which was similar to that of the unchallenged controls. Vaccinated chickens showed a significant increase in IBDV antibody titers, regardless of the type of vaccine used. In addition, significantly better broiler flock performance was observed with the HVT-IBD vector vaccine compared to that of the live vaccine. Our results revealed that the HVT-IBD vector vaccine could be used as an alternative vaccine to increase efficacy, and to have an improved safety profile compared with the IBDV live vaccine using in-ovo vaccination against the Korean very virulent IBDV in commercial broiler chickens.</P>

Curcumin suppresses the TPA-induced invasion through inhibition of PKCα-dependent MMP-expression in MCF-7 human breast cancer cells

Kim, J.M.,Noh, E.M.,Kwon, K.B.,Kim, J.S.,You, Y.O.,Hwang, J.K.,Hwang, B.M.,Kim, B.S.,Lee, S.H.,Lee, S.J.,Jung, S.H.,Youn, H.J.,Lee, Y.R. G. Fischer 2012 Phytomedicine Vol.19 No.12

Curcumin (diferuloylmethane) is a polyphenol derived from the plant turmeric (Curcuma longa), which is commonly used as a spice. Although anti-carcinogenic, anti-oxidant, anti-inflammation, and anti-angiogenic properties have been reported, the effect of curcumin on breast cancer metastasis is unknown. Matrix metalloproteinase-9 (MMP-9) is a major component in cancer cell invasion. In this study, we investigated the inhibitory effect of curcumin on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MMP-9 expression and cell invasion and the molecular mechanisms involved in MCF-7 cells. Our results showed that curcumin inhibits TPA-induced MMP-9 expression and cell invasion through suppressing NF-κB and AP-1 activation. Also, curcumin strongly repressed the TPA-induced phosphorylation of p38 and JNK and inhibited TPA-induced translocation of PKCα from the cytosol to the membrane, but did not affect the translocation of PKCδ. These results indicate that curcumin-mediated inhibition of TPA-induced MMP-9 expression and cell invasion involves the suppression of the PKCα, MAPK and NF-κB/AP-1 pathway in MCF-7 cells. Curcumin may have potential value in restricting breast cancer metastasis.

Hardening of Bi-Te based alloys by dispersing B₄C nanoparticles

Jung, S.J.,Park, S.Y.,Kim, B.K.,Kwon, B.,Kim, S.K.,Park, H.H.,Kim, D.I.,Kim, J.Y.,Hyun, D.B.,Kim, J.S.,Baek, S.H. Elsevier Science 2015 Acta materialia Vol.97 No.-

Thermoelectric devices have attracted a great attention for renewable energy harvesters and solid-state coolers. For practical applications, the mechanical properties of thermoelectric materials become critical for the device reliability, a persistent performance with a long time and high operation cycles. Bi-Te based single-crystals, mostly used in commercial thermoelectric devices, are intrinsically brittle with weak van der Waals bonding, often leading to device failures such as crack and debonding during fabrication and operation. Thus, it is highly desirable to enhance the mechanical property of Bi-Te based alloys as well as the thermoelectric property. Here, we investigate the effect of B<SUB>4</SUB>C nanoparticles (less than 0.5wt%) dispersed in p-type Bi<SUB>0.4</SUB>Sb<SUB>1.6</SUB>Te<SUB>3</SUB> matrix on the mechanical properties. X-ray diffraction (XRD) result confirms that B<SUB>4</SUB>C-dispersed Bi<SUB>0.4</SUB>Sb<SUB>1.6</SUB>Te<SUB>3</SUB> has a single phase. We observe that the grain size of Bi<SUB>0.4</SUB>Sb<SUB>1.6</SUB>Te<SUB>3</SUB> becomes decreased with the B<SUB>4</SUB>C nanoparticle concentration by electron backscatter diffraction (EBSD) technique. Hardness, Young's modulus, and flexural strength of B<SUB>4</SUB>C-dispersed Bi<SUB>0.4</SUB>Sb<SUB>1.6</SUB>Te<SUB>3</SUB> are enhanced, compared to the B<SUB>4</SUB>C-free Bi<SUB>0.4</SUB>Sb<SUB>1.6</SUB>Te<SUB>3</SUB> polycrystals. On the other hand, the thermoelectric figure-of-merit of B<SUB>4</SUB>C-dispersed Bi<SUB>0.4</SUB>Sb<SUB>1.6</SUB>Te<SUB>3</SUB> is almost identical to that of the pure Bi<SUB>0.4</SUB>Sb<SUB>1.6</SUB>Te<SUB>3</SUB>. Such enhancements of the mechanical properties of the B<SUB>4</SUB>C-dispersed Bi<SUB>0.4</SUB>Sb<SUB>1.6</SUB>Te<SUB>3</SUB> are attributed to the grain boundary hardening and second-phase hardening. Beyond thermoelectric materials, our result implies that the grain refinement by nanoparticle dispersion is a simple and promising way to strengthen the mechanical properties of other brittle materials with layered structure.

Caspase-3 activation as a key factor for HBx-transformed cell death

Kim, A.,Kwon, O. S.,Kim, S. O.,He, L.,Bae, E. Y.,Lee, M. S.,Jeong, S. J.,Shim, J. H.,Yoon, D. Y.,Kim, C. H.,Moon, A.,Kim, K. E.,Ahn, J. S.,Kim, B. Y. Blackwell Publishing Ltd 2008 Cell proliferation Vol.41 No.5

<P>Abstract. </P><P><I>Objectives</I>: Nuclear factor-kappa B (NF-&kgr;B) activation has been associated with the tumorigenic growth of hepatitis B virus X protein (HBx)-transformed cells. This study was aimed to find a key target for treatment of HBx-mediated cancers. <I>Materials and methods</I>: NF-&kgr;B activation, endoplasmic reticulum-stress (ER-stress), caspase-3 activation, and cell proliferation were evaluated after Chang/HBx cells permanently expressing HBx viral protein were treated with inhibitors of NF-&kgr;B, proteasome and DNA topoisomerase. <I>Results</I>: Inhibition of NF-&kgr;B transcriptional activity by transient transfection with mutant plasmids encoding Akt1 and glycogen synthase kinase-3&bgr; (GSK-3&bgr;), or by treatment with chemical inhibitors, wortmannin and LY294002, showed little effect on the survival of Chang/HBx cells. Furthermore, I&kgr;Bα (S32/36A) mutant plasmid or other NF-&kgr;B inhibitors, 1-pyrrolidinecarbonidithioic acid and sulphasalazine, were also shown to have little effect on the cell proliferation. By contrast, proteasome inhibitor-1 (Pro1) and MG132 enhanced the HBx-induced ER-stress response and the subsequent activation of caspase-12, -9 and -3 and reduced cell proliferation. Camptothecin (CPT), however, triggered activation of caspase-3 without induction of caspase-12, and reduced cell proliferation. In addition, CPT-induced cell death was reversed by pre-treatment with z-DEVD, a caspase-3-specific inhibitor. <I>Conclusions</I>: Detailed exploitation of the regulators of caspase-3 activation could open the gate for finding an efficient target for development of anticancer therapeutics against HBx-transformed hepatocellular carcinoma.</P>

Forebrain-specific ablation of phospholipase Cγ1 causes manic-like behavior

Yang, Y R,Jung, J H,Kim, S-J,Hamada, K,Suzuki, A,Kim, H J,Lee, J H,Kwon, O-B,Lee, Y K,Kim, J,Kim, E-K,Jang, H-J,Kang, D-S,Choi, J-S,Lee, C J,Marshall, J,Koh, H-Y,Kim, C-J,Seok, H,Kim, S H,Choi, J H,Ch Macmillan Publishers Limited, part of Springer Nat 2017 Molecular psychiatry Vol.22 No.10

<P>Manic episodes are one of the major diagnostic symptoms in a spectrum of neuropsychiatric disorders that include schizophrenia, obsessive-compulsive disorder and bipolar disorder (BD). Despite a possible association between BD and the gene encoding phospholipase C gamma 1 (PLCG1), its etiological basis remains unclear. Here, we report that mice lacking phospholipase C gamma 1 (PLC gamma 1) in the forebrain (Plcg1(f/f); CaMKII) exhibit hyperactivity, decreased anxiety-like behavior, reduced depressive-related behavior, hyperhedonia, hyperphagia, impaired learning and memory and exaggerated startle responses. Inhibitory transmission in hippocampal pyramidal neurons and striatal dopamine receptor D1-expressing neurons of Plcg1-deficient mice was significantly reduced. The decrease in inhibitory transmission is likely due to a reduced number of gamma-aminobutyric acid (GABA)-ergic boutons, which may result from impaired localization and/or stabilization of postsynaptic CaMKII (Ca2+/calmodulin-dependent protein kinase II) at inhibitory synapses. Moreover, mutant mice display impaired brain-derived neurotrophic factor-tropomyosin receptor kinase B-dependent synaptic plasticity in the hippocampus, which could account for deficits of spatial memory. Lithium and valproate, the drugs presently used to treat mania associated with BD, rescued the hyperactive phenotypes of Plcg1(f/f); CaMKII mice. These findings provide evidence that PLC gamma 1 is critical for synaptic function and plasticity and that the loss of PLC gamma 1 from the forebrain results in manic-like behavior.</P>

Early Regulation of Viral Infection Reduces Inflammation and Rescues Mx-positive Mice from Lethal avian Influenza Infection

Song, M.S.,Cho, Y.H.,Park, S.J.,Pascua, P.N.Q.,Baek, Y.H.,Kwon, H.I.,Lee, O.J.,Kong, B.W.,Kim, H.,Shin, E.C.,Kim, C.J.,Choi, Y.K. American Association of Pathologists and Bacteriol 2013 The American journal of pathology Vol.182 No.4

Differing sensitivity of influenza A viruses to antiviral effects of the Myxovirus resistance (Mx) protein implies varying global gene expression profiles in the host. The role of Mx protein during lethal avian influenza (AI) virus infection was examined using Mx1-deficient C57BL/6 (B6-Mx1<SUP>-/-</SUP>) and congenic Mx1-expressing (B6-Mx1<SUP>+/+</SUP>) mice infected with a virulent, mouse-adapted avian H5N2 Ab/Korea/ma81/07 (Av/ma81) virus. After infection, B6-Mx1<SUP>+/+</SUP> mice were completely protected from lethal AI-induced mortality, and exhibited attenuated clinical disease and reduced viral titers and pathology in the lungs, compared with B6-Mx1<SUP>-/-</SUP> mice. Transcriptional profiling of lung tissues revealed that most of the genes up-regulated after infection are involved in activation of the immune response and host defense. Notably, more abundant and sustained expression of cytokine/chemokine genes was observed up to 3 dpi in B6-Mx1<SUP>-/-</SUP> mice, and this was associated with excessive induction of cytokines and chemokines. Consequently, massive infiltration of macrophages/monocytes and granulocytes into lung resulted in severe viral pneumonia and potentially contributed to decreased survival of B6-Mx1<SUP>-/-</SUP> mice. Taken together, our data show that dysregulated gene transcriptional activity corresponded to persistent induction of cytokine/chemokines and recruitment of cytokine-producing cells that promote inflammation in B6-Mx1<SUP>-/-</SUP> mouse lungs. Thus, we provide additional evidence of the interplay of genetic, molecular, and cellular correlates governed by the Mx1 protein that critically determine disease outcome during lethal AI virus infection.

Aberrant ventral striatal responses during incentive processing in unmedicated patients with obsessive–compulsive disorder

Jung, W. H.,Kang, D.‐,H.,Han, J. Y.,Jang, J. H.,Gu, B.‐,M.,Choi, J.‐,S.,Jung, M. H.,Choi, C.‐,H.,Kwon, J. S. Blackwell Publishing Ltd 2011 Acta psychiatrica Scandinavica Vol.123 No.5

<P>Jung WH, Kang D‐H, Han JY, Jang JH, Gu B‐M, Choi J‐S, Jung MH, Choi C‐H, Kwon JS. Aberrant ventral striatal responses during incentive processing in unmedicated patients with obsessive–compulsive disorder.</P><P><B>Objective: </B> Obsessive–compulsive disorder (OCD) is characterized by the dysfunction of control and reward mechanisms. However, only few neuroimaging studies of OCD have examined the reward processing. We examined the neural responses during incentive processing in OCD.</P><P><B>Method: </B> Twenty unmedicated patients with OCD and 20 age‐, sex‐, and IQ‐matched healthy controls underwent functional magnetic resonance imaging while performing a modified monetary incentive delay task.</P><P><B>Results: </B> Compared with controls, patients with OCD showed increased ventral striatal activation in the no‐loss minus loss outcome contrast and a significant positive correlation between the ventral striatal activation and compulsion symptom severity. In addition, patients with OCD showed increased activations in the frontostriatal regions in the gain minus no‐gain outcomes contrast. During loss anticipation, patients with OCD showed less activations in the lateral prefrontal and inferior parietal cortices. However, during gain anticipation, patients with OCD and healthy controls did not differ in the ventral striatal activation.</P><P><B>Conclusion: </B> These findings provide neural evidence for altered incentive processing in unmedicated patients with OCD, suggesting an elevated sensitivity to negatively affect stimuli as well as dysfunction of the ventral striatum.</P>

Structural aspect of B*4811 molecule, a novel HLA-B*48 allele identified by sequence-based typing

Kwon, O.-J.,Hwang, S.-H.,Heo, Y.-S.,Hur, S.-S.,Oh, H.-B. Munksgaard 2005 Tissue antigens Vol.66 No.6