Probing the nature of high‐<i>z</i> short GRB 090426 with its early optical and X‐ray afterglows

Xin, Li&#x2010,Ping,Liang, En&#x2010,Wei,Wei, Jian&#x2010,Yan,Zhang, Bing,Lv, Hou&#x2010,Jun,Zheng, Wei&#x2010,Kang,Urata, Yuji,Im, Myungshin,Wang, Jing,Qiu, Yu&#x2010,Lei,Deng, Jin&#x2010,Song,Huang, Blackwell Publishing Ltd 2011 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.410 No.1

<P><B>ABSTRACT</B></P><P>GRB 090426 is a short‐duration burst detected by <I>Swift</I> (<IMG src='/wiley-blackwell_img/equation/MNR_17419_mu1.gif' alt ='inline image'/> s in the observer frame and <IMG src='/wiley-blackwell_img/equation/MNR_17419_mu2.gif' alt ='inline image'/> s in the burst frame at <I>z</I>= 2.609). Its host galaxy properties and some gamma‐ray‐related correlations are analogous to those seen in long‐duration gamma‐ray bursts (GRBs), which are believed to be of a massive star origin (so‐called Type II GRBs). We present the results of its early optical observations with the 0.8‐m Tsinghua University–National Astronomical Observatory of China Telescope (TNT) at Xinglong Observatory and the 1‐m LOAO telescope at Mt Lemmon Optical Astronomy Observatory in Arizona. Our well‐sampled optical afterglow light curve covers from <IMG src='/wiley-blackwell_img/equation/MNR_17419_mu3.gif' alt ='inline image'/> to 10<SUP>4</SUP> s after the GRB trigger. It shows two shallow decay episodes that are likely due to energy injection, which end at <IMG src='/wiley-blackwell_img/equation/MNR_17419_mu4.gif' alt ='inline image'/> and 7100 s, respectively. The decay slopes after the injection phases are consistent with each other (<IMG src='/wiley-blackwell_img/equation/MNR_17419_mu5.gif' alt ='inline image'/>). The X‐ray afterglow light curve appears to trace the optical, although the second energy‐injection phase was missed due to visibility constraints introduced by the <I>Swift</I> orbit. The X‐ray spectral index is <IMG src='/wiley-blackwell_img/equation/MNR_17419_mu6.gif' alt ='inline image'/> without temporal evolution. Its decay slope is consistent with the prediction of the forward shock model. Both X‐ray and optical emission are consistent with being in the same spectral regime above the cooling frequency (<IMG src='/wiley-blackwell_img/equation/MNR_17419_mu7.gif' alt ='inline image'/>). The fact that <IMG src='/wiley-blackwell_img/equation/MNR_17419_mu8.gif' alt ='inline image'/> is below the optical band from the very early epoch of the observation provides a constraint on the burst environment, which is similar to that seen in classical long‐duration GRBs. We therefore suggest that death of a massive star is the possible progenitor of this short burst.</P>

Enhanced Performance of Solution‐Processed TESPE‐ADT Thin‐Film Transistors

Chen, Liang&#x2010,Hsiang,Hu, Tarng&#x2010,Shiang,Huang, Peng&#x2010,Yi,Kim, Choongik,Yang, Ching&#x2010,Hao,Wang, Juin&#x2010,Jie,Yan, Jing&#x2010,Yi,Ho, Jia&#x2010,Chong,Lee, Cheng&#x2010,Chung,Chen WILEY‐VCH Verlag 2013 Chemphyschem Vol.14 No.12

<P><B>Abstract</B></P><P>A solution‐processed anthradithiophene derivative, 5,11‐bis(4‐triethylsilylphenylethynyl)anthradithiophene (TESPE‐ADT), is studied for use as the semiconducting material in thin‐film transistors (TFTs). To enhance the electrical performance of the devices, two different kinds of solution processing (spin‐coating and drop‐casting) on various gate dielectrics as well as additional post‐treatment are employed on thin films of TESPE‐ADT, and <I>p</I>‐channel OTFT transport with hole mobilities as high as ∼0.12 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP> are achieved. The film morphologies and formed microstructures of the semiconductor films are characterized in terms of film processing conditions and are correlated with variations in device performance.</P>

Prediction of homoprotein and heteroprotein complexes by protein docking and template‐based modeling: A CASP‐CAPRI experiment

Lensink, Marc F.,Velankar, Sameer,Kryshtafovych, Andriy,Huang, Shen&#x2010,You,Schneidman&#x2010,Duhovny, Dina,Sali, Andrej,Segura, Joan,Fernandez&#x2010,Fuentes, Narcis,Viswanath, Shruthi,Elber, Ron John Wiley and Sons Inc. 2016 Proteins Vol.84 No.-

<P><B>ABSTRACT</B></P><P>We present the results for CAPRI Round 30, the first joint CASP‐CAPRI experiment, which brought together experts from the protein structure prediction and protein–protein docking communities. The Round comprised 25 targets from amongst those submitted for the CASP11 prediction experiment of 2014. The targets included mostly homodimers, a few homotetramers, and two heterodimers, and comprised protein chains that could readily be modeled using templates from the Protein Data Bank. On average 24 CAPRI groups and 7 CASP groups submitted docking predictions for each target, and 12 CAPRI groups per target participated in the CAPRI scoring experiment. In total more than 9500 models were assessed against the 3D structures of the corresponding target complexes. Results show that the prediction of homodimer assemblies by homology modeling techniques and docking calculations is quite successful for targets featuring large enough subunit interfaces to represent stable associations. Targets with ambiguous or inaccurate oligomeric state assignments, often featuring crystal contact‐sized interfaces, represented a confounding factor. For those, a much poorer prediction performance was achieved, while nonetheless often providing helpful clues on the correct oligomeric state of the protein. The prediction performance was very poor for genuine tetrameric targets, where the inaccuracy of the homology‐built subunit models and the smaller pair‐wise interfaces severely limited the ability to derive the correct assembly mode. Our analysis also shows that docking procedures tend to perform better than standard homology modeling techniques and that highly accurate models of the protein components are not always required to identify their association modes with acceptable accuracy. Proteins 2016; 84(Suppl 1):323–348. © 2016 The Authors Proteins: Structure, Function, and Bioinformatics Published by Wiley Periodicals, Inc.</P>

<i>In Situ</i> Atomic-Scale Observation of Surface-Tension-Induced Structural Transformation of Ag-NiP_<i>x</i> Core-Shell Nanocrystals

Huang, Xing,Liu, Zhongqiang,Millet, Marie-Mathilde,Dong, Jichen,Plodine, Milivoj,Ding, Feng,Schlo&#x308,gl, Robert,Willinger, Marc-Georg American Chemical Society 2018 ACS NANO Vol.12 No.7

<P>The properties of nanocrystals are highly dependent on their morphology, composition, and structure. Tailored synthesis over these parameters is successfully applied for the production of nanocrystals with desired properties for specific applications. However, in order to obtain full control over the properties, the behavior of nanocrystals under external stimuli and application conditions needs to be understood. Herein, using Ag-NiP<SUB><I>x</I></SUB> nanocrystals as a model system, we investigate the structural evolution upon thermal treatment by <I>in situ</I> aberration-corrected scanning transmission electron microscopy. A combination of real-time imaging with elemental analysis enables the observation of the transformation from a Ag-NiP<SUB><I>x</I></SUB> core-shell configuration to a Janus structure at the atomic scale. The transformation occurs through dewetting and crystallization of the NiP<SUB><I>x</I></SUB> shell and is accompanied by surface segregation of Ag. Further temperature increase leads to a complete sublimation of Ag and formation of individual Ni<SUB>12</SUB>P<SUB>5</SUB> nanocrystals. The transformation is rationalized by theoretical modeling based on density functional theory calculations. Our model suggests that the transformation is driven by changes of the surface energy of NiP<SUB><I>x</I></SUB> and the interfacial energy between NiP<SUB><I>x</I></SUB> and Ag. The direct observation of atomistic dynamics during thermal-treatment-induced structural modification will help to understand more complex transformations that are induced by aging over time or the interaction with a reactive gas phase in applications such as catalysis.</P> [FIG OMISSION]</BR>

3‐Hydroxymorphinan, a metabolite of dextromethorphan, protects nigrostriatal pathway against MPTP‐elicited damage both <i>in vivo</i> and <i>in vitro</i>

Zhang, Wei,Shin, Eun&#x2010,Joo,Wang, Tongguang,Lee, Phil Ho,Pang, Hao,Wie, Myung&#x2010,Bok,Kim, Won&#x2010,Ki,Kim, Seong&#x2010,Jin,Huang, Wen&#x2010,Hsin,Wang, Yongjun,Zhang, Wanqin,Hong, Jau&#x201 Federation of American Society for Experimental Bi 2006 The FASEB Journal Vol.20 No.14

<P>We investigated the neuroprotective property of analogs of dextromethorphan (DM) in lipopolysaccharide (LPS) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) models to identify neuroprotective drugs for Parkinson's disease (PD). In vivo studies showed that daily injections with DM analogs protected dopamine (DA) neurons in substantia nigra pars compacta and restored DA levels in striatum using two different models for PD. Of the five analogs studied, 3-hydroxymorphinan (3-HM), a metabolite of DM, was the most potent, and restored DA neuronal loss and DA depletion up to 90% of the controls. Behavioral studies showed an excellent correlation between potency for preventing toxin-induced decrease in motor activities and neuroprotective effects among the DM analogs studied, of which 3-HM was the most potent in attenuating behavioral damage. In vitro studies revealed two glia-dependent mechanisms for the neuroprotection by 3-HM. First, astroglia mediated the 3-HM-induced neurotrophic effect by increasing the gene expression of neurotrophic factors, which was associated with the increased acetylation of histone H3. Second, microglia participated in 3-HM-mediated neuroprotection by reducing MPTP-elicited reactive microgliosis as evidenced by the decreased production of reactive oxygen species. In summary, we show the potent neuroprotection by 3-HM in LPS and MPTP PD models investigated. With its high efficacy and low toxicity, 3-HM may be a novel therapy for PD.</P>

Radiofrequency radiation does not induce stress response in human T‐lymphocytes and rat primary astrocytes

Lee, Jae&#x2010,Seon,Huang, Tai&#x2010,Qin,Kim, Tae&#x2010,Hyung,Kim, Jin Young,Kim, Hyun Jeong,Pack, Jeong&#x2010,Ki,Seo, Jeong&#x2010,Sun Wiley Subscription Services, Inc., A Wiley Company 2006 BioElectroMagnetics Vol.27 No.7

<P><B>Abstract</B></P><P>Heat shock proteins (HSPs) are rapidly induced by a variety of stressors, including heat shock, ethanol, heavy metals, UV, and γ‐radiation. Mitogen‐activated protein kinases (MAPKs) are also involved in the stress transduction pathways in all eukaryotes. In this study, we attempted to determine whether radiofrequency (RF) radiation is able to induce a non‐thermal stress response. Human T‐lymphocyte Jurkat cells and rat primary astrocytes were exposed to 1763 MHz of RF radiation at an average specific absorption rate (SAR) of either 2 W/kg or 20 W/kg, for 30 min or 1 h. Temperature was completely controlled at 37 ± 0.2 °C throughout the exposure period. The sham exposures were performed under exactly identical experimental conditions without exposure to RF radiation. We assessed alterations in the expression of HSPs and the activation of MAPKs in the RF‐exposed cells. No detectable difference was observed in the expression levels of HSP90, HSP70, and HSP27. The phosphorylation status of MAPKs, extracellular signal‐regulated kinases (ERK1/2), c‐Jun N‐terminal protein kinases (JNK1/2), or p38, did not change significantly. In order to determine whether RF radiation can promote the effects of 12‐O‐tetradecanoylphorbol 13‐acetate (TPA) on stress response, cells were exposed to RF radiation coupled with TPA treatment. When TPA alone was applied, the MAPKs were found to be phosphorylated in a dose‐dependent manner. However, RF radiation did not result in any enhancement of TPA‐induced MAPK phosphorylation. Neither TPA nor RF radiation exerted any detectable effect on the induction of HSPs. These results indicate that 1763 MHz RF radiation alone did not elicit any stress response, nor did it have any effect on TPA‐induced MAPK phosphorylation, under our experimental conditions. Bioelectromagnetics 27:578–588, 2006. © 2006 Wiley‐Liss, Inc.</P>

Self‐Propagating Domino‐like Reactions in Oxidized Graphite

Kim, Franklin,Luo, Jiayan,Cruz&#x2010,Silva, Rodolfo,Cote, Laura J.,Sohn, Kwonnam,Huang, Jiaxing WILEY‐VCH Verlag 2010 Advanced Functional Materials Vol.20 No.17

<P><B>Abstract</B></P><P>Graphite oxide (GO) has received extensive interest as a precursor for the bulk production of graphene‐based materials. Here, the highly energetic nature of GO, noted from the self‐propagating thermal deoxygenating reaction observed in solid state, is explored. Although the resulting graphene product is quite stable against combustion even in a natural gas flame, its thermal stability is significantly reduced when contaminated with potassium salt by‐products left from GO synthesis. In particular, the contaminated GO becomes highly flammable. A gentle touch with a hot soldering iron can trigger violent, catastrophic, total combustion of such GO films, which poses a serious fire hazard. This highlights the need for efficient sample purification methods. Typically, purification of GO is hindered by its tendency to gelate as the pH value increases during rinsing. A two‐step, acid–acetone washing procedure is found to be effective for suppressing gelation and thus facilitating purification. Salt‐induced flammability is alarming for the fire safety of large‐scale manufacturing, processing, and storage of GO materials. However, the energy released from the deoxygenation of GO can also be harnessed to drive new reactions for creating graphene‐based hybrid materials. Through such domino‐like reactions, graphene sheets decorated with metal and metal oxide particles are synthesized using GO as the in situ power source. Enhanced electrochemical capacitance is observed for graphene sheets loaded with RuO<SUB>2</SUB> nanoparticles.</P>

Facile synthesis of porous TiO₂ nanospheres and their photocatalytic properties

Huang, J.,Ren, H.,Liu, X.,Li, X.,Shim, J.J. Academic Press 2015 Superlattices and microstructures Vol.81 No.-

Uniform and monodisperse porous TiO<SUB>2</SUB> nanospheres were synthesized by a hydrothermal method. Techniques of X-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller (BET) nitrogen adsorption-desorption, UV-vis absorption spectroscopy, and transmission electron microscopy were used to characterize the structure and morphology of the products. The BET surface area of the porous TiO<SUB>2</SUB> nanospheres was calculated to be 26.1cm<SUP>2</SUP>g<SUP>-1</SUP>. In addition, the obtained porous TiO<SUB>2</SUB> nanospheres were used as catalyst to photodegrade methylene blue, Rhodamine B, methyl orange, p-nitrophenol, and eosin B. Compared to commercial TiO<SUB>2</SUB> powder, the as-prepared porous TiO<SUB>2</SUB> nanospheres exhibited higher catalytic activities due to their large surface areas and porous nanostructures. The photocatalytic reaction rate constant of the porous TiO<SUB>2</SUB> nanospheres in photocatalytic decomposition of methylene blue and Rhodamine B under simulated solar light were calculated as 0.0545min<SUP>-1</SUP> and 0.0579min<SUP>-1</SUP>, respectively. Moreover, the catalyst was demonstrated to have good stability and reusability.

Molecular Dynamics Simulation of Oxygen Ion Diffusion in Yttria Stabilized Zirconia Single Crystals and Bicrystals

Huang, H. C.,Su, P.&#x2010,C.,Kwak, S. K.,Pornprasertsuk, R.,Yoon, Y.&#x2010,J. WILEY‐VCH Verlag 2014 Fuel Cells Vol.14 No.4

<P><B>Abstract</B></P><P>Molecular dynamics simulation studies have been performed to study the oxygen ion diffusion in yttria stabilized zirconia single crystals and bicrystals separated by tilt grain boundaries (GBs). Two types of GBs which are Σ 5 (3 1 0) and Σ 13 (5 1 0) are studied at temperatures between 1,000 K and 2,000 K. The effect of grain size, which is the distance between two GBs, and the effect of GB orientations are systematically investigated in this study. The oxygen diffusion in the bicrystals is found to be blocked by the GB, and the blocking effect increases with decreasing grain size and is affected by different grain orientations. In addition, the oxygen diffusion along the GB plane is most hindered.</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.