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Sample records for 2s 3r 4s

  1. Non-insulin dependent anti-diabetic activity of (2S, 3R, 4S) 4-hydroxyisoleucine of fenugreek (Trigonella foenum graecum) in streptozotocin-induced type I diabetic rats.

    PubMed

    Haeri, Mohammed R; Limaki, Hamidreza Khalatbari; White, Christopher J Branford; White, Kenneth N

    2012-05-15

    The seeds of fenugreek, Trigonella foenum graecum, commonly used as a spice in Middle Eastern countries and widely used in south Asia and Europe, are known to have anti-diabetic properties. They contain an unusual amino acid (2S, 3R, 4S) 4-hydroxyisoleucine (4HO-Ile), so far found only in fenugreek, which has anti-diabetic properties of enhancing insulin secretion under hyperglycaemic conditions, and increasing insulin sensitivity. Here we describe for the first time the anti-diabetic activity of 4HO-Ile in a model of type I diabetes, streptozotocin-treated rats, where levels of insulin are much reduced, by 65%, compared to normal animals. Treatment of diabetic rats with daily doses of 4HO-Ile at 50 mg/kg/day for four weeks could reduce plasma glucose in the diabetic group. Moreover the high levels of lipids (cholesterol, HDL, LDL and triglycerides) and uric acid in the diabetic rats, could be restored to levels found in non-diabetic controls by the treatment with 4HO-Ile. These results demonstrate that 4HO-Ile has significant anti-diabetic activities that are independent of insulin and suggest the potential of 4HO-Ile as an adjunct to diabetes treatment and for type 1 as well as type 2 diabetes.

  2. (3R,4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1-yl]chroman-4,7-diol: a conformationally restricted analogue of the NR2B subtype-selective NMDA antagonist (1S,2S)-1-(4-hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)- 1-propanol.

    PubMed

    Butler, T W; Blake, J F; Bordner, J; Butler, P; Chenard, B L; Collins, M A; DeCosta, D; Ducat, M J; Eisenhard, M E; Menniti, F S; Pagnozzi, M J; Sands, S B; Segelstein, B E; Volberg, W; White, W F; Zhao, D

    1998-03-26

    (1S,2S)-1-(4-Hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)-1-propanol (CP-101,606, 1) is a recently described antagonist of N-methyl-D-aspartate (NMDA) receptors containing the NR2B subunit. In the present study, the optimal orientation of compounds of this structural type for their receptor was explored. Tethering of the pendent methyl group of 1 to the phenolic aromatic ring via an oxygen atom prevents rotation about the central portion of the molecule. Several of the new chromanol compounds have high affinity for the racemic [3H]CP-101,606 binding site on the NMDA receptor and protect against glutamate toxicity in cultured hippocampal neurons. The new ring caused a change in the stereochemical preference of the receptor-cis (erythro) compounds had better affinity for the receptor than the trans isomers. Computational studies suggest that steric interactions between the pendent methyl group and the phenol ring in the acyclic series determine which structures can best fit the receptor. The chromanol analogue, (3R,4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1- yl]chroman-4,7-diol (12a, CP-283,097), was found to possess potency and selectivity comparable to CP-101,606. Thus 12a is a new tool to explore the function of the NR2B-containing NMDA receptors.

  3. Structure-activity relationship of daptomycin analogues with substitution at (2S, 3R) 3-methyl glutamic acid position.

    PubMed

    Lin, Du'an; Lam, Hiu Yung; Han, Wenbo; Cotroneo, Nicole; Pandya, Bhaumik A; Li, Xuechen

    2017-02-01

    Daptomycin is a highly effective lipopeptide antibiotic against Gram-positive pathogens. The presence of (2S, 3R) 3-methyl glutamic acid (mGlu) in daptomycin has been found to be important to the antibacterial activity. However the role of (2S, 3R) mGlu is yet to be revealed. Herein, we reported the syntheses of three daptomycin analogues with (2S, 3R) mGlu substituted by (2S, 3R) methyl glutamine (mGln), dimethyl glutamic acid and (2S, 3R) ethyl glutamic acid (eGlu), respectively, and their antibacterial activities. The detailed synthesis of dimethyl glutamic acid was also reported.

  4. Rapid preparation of (3R,4S,5R) polyhydroxylated pyrrolidine-based libraries to discover a pharmacological chaperone for treatment of Fabry disease.

    PubMed

    Cheng, Wei-Chieh; Wang, Jen-Hon; Yun, Wen-Yi; Li, Huang-Yi; Hu, Jia-Ming

    2017-01-27

    The rapid discovery of a pharmacological chaperone toward human α-Gal A for the treatment of Fabry disease is described. Two polyhydroxylated pyrrolidines with the (3R,4S,5R) configuration pattern underwent rapid substituent diversity by conjugating the primary aminomethyl moiety of each with a variety of carboxylic acids to generate two libraries (2 × 60 members). Our bioevaluation results showed one member with the (2R,3R,4S,5R) configuration pattern and bearing a 5-cyclohexylpentanoyl group as a substituent moiety possessed sufficient chaperoning capability to rescue α-Gal A activity in the lymphocyte of the N215S Fabry patient-derived cell line and other α-Gal A mutants in COS7 cells.

  5. Observation of Upsilon(4S) decays to pi(+)pi(-)Upsilon(1S) and pi(+)pi(-)Upsilon(2S).

    PubMed

    Aubert, B; Barate, R; Bona, M; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Andreassen, R; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Petzold, A; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Grenier, P; Latour, E; Thiebaux, Ch; Verderi, M; Bard, D J; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Gaillard, J R; Nash, J A; Nikolich, M B; Panduro Vazquez, W; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Brown, C L; Cowan, G; Flaecher, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Kelly, M P; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Staengle, H; Willocq, S Y; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, G; Del Re, D; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Lu, M; Potter, C T; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Galeazzi, F; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; Hartfiel, B L; John, M J J; Malclès, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Rizzo, G; Walsh, J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai Tehrani, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Legendre, M; Vasseur, G; Yèche, Ch; Zito, M; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Boyarski, A M; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dong, D; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'grady, C P; Ozcan, V E; Perl, M; Perazzo, A; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Vitale, L; Azzolini, V; Martinez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Hollar, J J; Kutter, P E; Li, H; Liu, R; Mellado, B; Mihalyi, A; Mohapatra, A K; Pan, Y; Pierini, M; Prepost, R; Tan, P; Wu, S L; Yu, Z; Neal, H

    2006-06-16

    Observation of Upsilon(4S) decays to pi(+)pi(-)C and pi(+)pi(-)Upsilon(2S)We present the first measurement of Upsilon(4S) decays to pi(+)pi(-)Upsilon(1S) based on a sample of 230 x 106(4S) mesons collected with the BABAR detector. We measure the product branching fractions Beta(Upsilon(4S) --> pi(+)pi(-)Upsilon(1S)) x BetaUpsilon(1S) --> mu(+)mu(-) = (2.23 +/- 0.25(stat) +/- 0.27(syst))x 10(-6) and Beta(Upsilon(4S) --> pi(+)pi(-)Upsilon(2S) x Beta(Upsilon(2S) --> mu(+)mu(-))=(1.69 +/-0.26(stat) +/- 0.20(syst)) x 10(-)6, from which we derive the partial widths Gamma(Upsilon(4S) --> pi(+)pi(-)Upsilon(1S))=(1.8 +/-0.4) keV and Gamma(Upsilon(4S) --> pi(+)pi(-)Upsilon(2S))=(2.7 +/- 0.8) keV.

  6. Search for missing ψ (4 S ) in the e+e-→π+π-ψ (2 S ) process

    NASA Astrophysics Data System (ADS)

    Chen, Dian-Yong; Liu, Xiang; Matsuki, Takayuki

    2016-02-01

    A detailed analysis to find a missing ψ (4 S ) is made by utilizing the recent precise measurements of the cross section for the process e+e-→ψ (2 S )π+π- by Belle. Assuming three resonances Y (4360 ), Y (4660 ), and ψ (4 S ) to fit the data, we obtain the resonance parameters for ψ (4 S ) as m =4243 MeV and Γ =16 ±31 MeV , showing a narrow state as predicted before. A combined fit to the data e+e-→ψ (2 S )π+π- , hcπ+π- , and χc 0ω is also performed to obtain the similar resonance parameters of ψ (4 S ). The upper limit of the branching ratio is fitted to be B (ψ (4 S )→ψ (2 S )π+π-)<3 ×10-3, which can be understood by hadronic loop contributions within a reasonable range of parameters. In addition, the ratios of the branching ratios of the ψ (4 S ) dipion transition to that of ψ (4 S )→χc 0ω are fitted, which can be further measured by BESIII and the forthcoming BelleII to confirm the existence of ψ (4 S ).

  7. Arabidopsis thaliana Nfu2 accommodates [2Fe-2S] or [4Fe-4S] clusters and is competent for in vitro maturation of chloroplast [2Fe-2S] and [4Fe-4S] cluster-containing proteins†

    PubMed Central

    Gao, Huanyao; Subramanian, Sowmya; Couturier, Jérémy; Naik, Sunil; Kim, Sung-Kun; Leustek, Thomas; Knaff, David B.; Wu, Hui-Chen; Vignols, Florence; Huynh, Boi Hanh; Rouhier, Nicolas; Johnson, Michael K.

    2013-01-01

    Nfu-type proteins are essential in the biogenesis of iron-sulfur (Fe-S) clusters in numerous organisms. A number of phenotypes including low levels of Fe-S cluster incorporation are associated with deletion of the gene encoding a chloroplast-specific Nfu-type protein, Nfu2 from Arabidopsis thaliana (AtNfu2). Here we report that recombinant AtNfu2 is able to assemble both [2Fe-2S] and [4Fe-4S] clusters. Analytical data and gel filtration studies support cluster/protein stoichiometries of one [2Fe-2S] cluster/homotetramer and one [4Fe-4S] cluster/homodimer. The combination of UV-visible absorption and circular dichroism, resonance Raman and Mössbauer spectroscopies has been employed to investigate the nature, properties and transfer of the clusters assembled on Nfu2. The results are consistent with subunit-bridging [2Fe-2S]2+ and [4Fe-4S]2+ clusters coordinated by the cysteines in the conserved CXXC motif. The results also provided insight into the specificity of Nfu2 for maturation of chloroplastic Fe-S proteins via intact, rapid and quantitative cluster transfer. [2Fe-2S] cluster-bound Nfu2 is shown to be an effective [2Fe-2S]2+ cluster donor for glutaredoxin S16, but not glutaredoxin S14. Moreover, [4Fe-4S] cluster-bound Nfu2 is shown to be a very rapid and efficient [4Fe-4S]2+ cluster donor for adenosine 5′-phosphosulfate reductase (APR1) and yeast two-hybrid studies indicate that APR1 forms a complex with Nfu2, but not with Nfu1 and Nfu3, the two other chloroplastic Nfu proteins. This cluster transfer is likely to be physiologically relevant and is particularly significant for plant metabolism as APR1 catalyzes the second step in reductive sulfur assimilation which ultimately results in the biosynthesis of cysteine, methionine, glutathione, and Fe-S clusters. PMID:24032747

  8. Heterologous overproduction of 2[4Fe4S]- and [2Fe2S]-type clostridial ferredoxins and [2Fe2S]-type agrobacterial ferredoxin.

    PubMed

    Huang, Haiyan; Hu, Liejie; Yu, Wenjun; Li, Huili; Tao, Fei; Xie, Huijun; Wang, Shuning

    2016-05-01

    Ferredoxins are small, acidic proteins containing iron-sulfur clusters that are widespread in living organisms. They play key roles as electron carriers in various metabolic processes, including respiration, photosynthesis, fermentation, nitrogen fixation, carbon dioxide fixation, and hydrogen production. However, only several kinds of ferredoxins are commercially available now, greatly limiting the investigation of ferredoxin-related enzymes and metabolic processes. Here we describe the heterologous overproduction of 2[4Fe4S]- and [2Fe2S]-type clostridial ferredoxins and [2Fe2S]-type agrobacterial ferredoxin. Adding extra iron and sulfur sources to the medium in combination with using Escherichia coli C41(DE3) harboring pCodonplus and pRKISC plasmids as host greatly enhanced iron-sulfur cluster synthesis in the three ferredoxins. After induction for 12 h in terrific broth and purification by affinity chromatography and anion exchange chromatography, approximately 3.4 mg of streptavidin (Strep)-tagged and 3.7 mg of polyhistidine (His)-tagged clostridial 2[4Fe4S] ferredoxins were obtained from 1 l of culture. Excitingly, after induction for 24 h in terrific broth, around 40 mg of His-tagged clostridial [2Fe2S] and 23 mg of His-tagged agrobacterial [2Fe2S] ferredoxins were purified from 1 l of culture. The recombinant ferredoxins apparently exhibited identical properties and physiological function to native ferredoxins. No negative impact of two different affinity tags on ferredoxin activity was found. In conclusion, we successfully developed a convenient method for heterologous overproduction of the three kinds of ferredoxins with satisfactory yields and activities, which would be very helpful for the ferredoxin-related researches.

  9. Calculation of the total electron excitation cross section in the Born approximation using Slater wave functions for the Li (2s yields 2p), Li (2s yields 3p), Na (3s yields 4p), Mg (3p yields 4s), Ca (4s yields 4p) and K (4s yields 4p) excitations. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Simsic, P. L.

    1974-01-01

    Excitation of neutral atoms by inelastic scattering of incident electrons in gaseous nebulae were investigated using Slater Wave functions to describe the initial and final states of the atom. Total cross sections using the Born Approximation are calculated for: Li(2s yields 2p), Na(3s yields 4p), k(4s yields 4p). The intensity of emitted radiation from gaseous nebulae is also calculated, and Maxwell distribution is employed to average the kinetic energy of electrons.

  10. Isotope shift of 40,42,44,48Ca in the 4s 2S1/2 → 4p 2P3/2 transition

    NASA Astrophysics Data System (ADS)

    Gorges, C.; Blaum, K.; Frömmgen, N.; Geppert, Ch; Hammen, M.; Kaufmann, S.; Krämer, J.; Krieger, A.; Neugart, R.; Sánchez, R.; Nörtershäuser, W.

    2015-12-01

    We report on improved isotope shift measurements of the isotopes {}{40,42,{44,48}}Ca in the 4{{s}}{ }2{{{S}}}1/2\\to 4{{p}}{ }2{{{P}}}3/2 (D2) transition using collinear laser spectroscopy. Accurately known isotope shifts in the 4{{s}}{ }2{{{S}}}1/2\\to 4{{p}}{ }2{{{P}}}1/2(D1) transition were used to calibrate the ion beam energy with an uncertainty of {{Δ }}U≈ +/- 0.25 {{V}}. The accuracy in the D2 transition was improved by a factor of 5-10. A King-plot analysis of the two transitions revealed that the field shift factor in the D2 line is about 1.8(13)% larger than in the D1 transition which is ascribed to relativistic contributions of the 4{{{p}}}1/2 wave function.

  11. The O2 sensitivity of the transcription factor FNR is controlled by Ser24 modulating the kinetics of [4Fe-4S] to [2Fe-2S] conversion

    PubMed Central

    Jervis, Adrian J.; Crack, Jason C.; White, Gaye; Artymiuk, Peter J.; Cheesman, Myles R.; Thomson, Andrew J.; Le Brun, Nick E.; Green, Jeffrey

    2009-01-01

    Fumarate and nitrate reduction regulatory (FNR) proteins are bacterial transcription factors that coordinate the switch between aerobic and anaerobic metabolism. In the absence of O2, FNR binds a [4Fe-4S]2+ cluster (ligated by Cys-20, 23, 29, 122) promoting the formation of a transcriptionally active dimer. In the presence of O2, FNR is converted into a monomeric, non-DNA-binding form containing a [2Fe-2S]2+ cluster. The reaction of the [4Fe-4S]2+ cluster with O2 has been shown to proceed via a 2-step process, an O2-dependent 1-electron oxidation to yield a [3Fe-4S]+ intermediate with release of 1 Fe2+ ion, followed by spontaneous rearrangement to the [2Fe-2S]2+ form with release of 1 Fe3+ and 2 S2− ions. Here, we show that replacement of Ser-24 by Arg, His, Phe, Trp, or Tyr enhances aerobic activity of FNR in vivo. The FNR-S24F protein incorporates a [4Fe-4S]2+ cluster with spectroscopic properties similar to those of FNR. However, the substitution enhances the stability of the [4Fe-4S]2+ cluster in the presence of O2. Kinetic analysis shows that both steps 1 and 2 are slower for FNR-S24F than for FNR. A molecular model suggests that step 1 of the FNR-S24F iron–sulfur cluster reaction with O2 is inhibited by shielding of the iron ligand Cys-23, suggesting that Cys-23 or the cluster iron bound to it is a primary site of O2 interaction. These data lead to a simple model of the FNR switch with physiological implications for the ability of FNR proteins to operate over different ranges of in vivo O2 concentrations. PMID:19261852

  12. The conserved protein Dre2 uses essential [2Fe-2S] and [4Fe-4S] clusters for its function in cytosolic iron-sulfur protein assembly.

    PubMed

    Netz, Daili J A; Genau, Heide M; Weiler, Benjamin D; Bill, Eckhard; Pierik, Antonio J; Lill, Roland

    2016-07-15

    The cytosolic iron-sulfur (Fe-S) protein assembly (CIA) machinery comprises 11 essential components and matures Fe-S proteins involved in translation and genome maintenance. Maturation is initiated by the electron transfer chain NADPH-diflavin reductase Tah18-Fe-S protein Dre2 that facilitates the de novo assembly of a [4Fe-4S] cluster on the scaffold complex Cfd1-Nbp35. Tah18-Dre2 also play a critical role in the assembly of the diferric tyrosyl radical cofactor of ribonucleotide reductase. Dre2 contains eight conserved cysteine residues as potential co-ordinating ligands for Fe-S clusters but their functional importance and the type of bound clusters is unclear. In the present study, we use a combination of mutagenesis, cell biological and biochemical as well as UV-visible, EPR and Mössbauer spectroscopic approaches to show that the yeast Dre2 cysteine residues Cys(252), Cys(263), Cys(266) and Cys(268) (motif I) bind a [2Fe-2S] cluster, whereas cysteine residues Cys(311), Cys(314), Cys(322) and Cys(325) (motif II) co-ordinate a [4Fe-4S] cluster. All of these residues with the exception of Cys(252) are essential for cell viability, cytosolic Fe-S protein activity and in vivo (55)Fe-S cluster incorporation. The N-terminal methyltransferase-like domain of Dre2 is important for proper Fe-S cluster assembly at motifs I and II, which occurs in an interdependent fashion. Our findings further resolve why recombinant Dre2 from Arabidopsis, Trypanosoma or humans has previously been isolated with a single [2Fe-2S] instead of native [2Fe-2S] plus [4Fe-4S] clusters. In the presence of oxygen, the motif I-bound [2Fe-2S] cluster is labile and the motif II-bound [4Fe-4S] cluster is readily converted into a [2Fe-2S] cluster.

  13. Effects of Zb states and bottom meson loops on ϒ (4 S )→ϒ (1 S ,2 S )π+π- transitions

    NASA Astrophysics Data System (ADS)

    Chen, Yun-Hua; Cleven, Martin; Daub, Johanna T.; Guo, Feng-Kun; Hanhart, Christoph; Kubis, Bastian; Meißner, Ulf-G.; Zou, Bing-Song

    2017-02-01

    We study the dipion transitions ϒ (4 S )→ϒ (n S )π+π- (n =1 ,2 ) . In particular, we consider the effects of the two intermediate bottomoniumlike exotic states Zb(10610 ) and Zb(10650 ) as well as bottom meson loops. The strong pion-pion final-state interactions, especially including channel coupling to K K ¯ in the S wave, are taken into account model independently by using dispersion theory. Based on a nonrelativistic effective field theory we find that the contribution from the bottom meson loops is comparable to those from the chiral contact terms and the Zb-exchange terms. For the ϒ (4 S )→ϒ (2 S )π+π- decay, the result shows that including the effects of the Zb exchange and the bottom meson loops can naturally reproduce the two-hump behavior of the π π mass spectra. Future angular distribution data are decisive for the identification of different production mechanisms. For the ϒ (4 S )→ϒ (1 S )π+π- decay, we show that there is a narrow dip around 1 GeV in the π π invariant mass distribution, caused by the final-state interactions. The distribution is clearly different from that in similar transitions from lower ϒ states, and needs to be verified by future data with high statistics. Also we predict the decay width and the dikaon mass distribution of the ϒ (4 S )→ϒ (1 S )K+K- process.

  14. UV radiation effects on a DNA repair enzyme: conversion of a [4Fe-4S](2+) cluster into a [2Fe-2S] (2+).

    PubMed

    Folgosa, Filipe; Camacho, Inês; Penas, Daniela; Guilherme, Márcia; Fróis, João; Ribeiro, Paulo A; Tavares, Pedro; Pereira, Alice S

    2015-03-01

    Organisms are often exposed to different types of ionizing radiation that, directly or not, will promote damage to DNA molecules and/or other cellular structures. Because of that, organisms developed a wide range of response mechanisms to deal with these threats. Endonuclease III is one of the enzymes responsible to detect and repair oxidized pyrimidine base lesions. However, the effect of radiation on the structure/function of these enzymes is not clear yet. Here, we demonstrate the effect of UV-C radiation on E. coli endonuclease III through several techniques, namely UV-visible, fluorescence and Mössbauer spectroscopies, as well as SDS-PAGE and electrophoretic mobility shift assay. We demonstrate that irradiation with a UV-C source has dramatic consequences on the absorption, fluorescence, structure and functionality of the protein, affecting its [4Fe-4S] cluster and its DNA-binding ability, which results in its inactivation. An UV-C radiation-induced conversion of the [4Fe-4S](2+) into a [2Fe-2S](2+) was observed for the first time and proven by Mössbauer and UV-visible analysis. This work also shows that the DNA-binding capability of endonuclease III is highly dependent of the nuclearity of the endogenous iron-sulfur cluster. Thus, from our point of view, in a cellular context, these results strengthen the argument that cellular sensitivity to radiation can also be due to loss of radiation-induced damage repair ability.

  15. Target-oriented discovery of a new esterase-producing strain Enterobacter sp. ECU1107 for whole cell-catalyzed production of (2S,3R)-3-phenylglycidate as a chiral synthon of Taxol.

    PubMed

    Zhou, Dong-Jie; Pan, Jiang; Yu, Hui-Lei; Zheng, Gao-Wei; Xu, Jian-He

    2013-07-01

    A new strain, Enterobacter sp. ECU1107, was identified among over 200 soil isolates using a two-step screening strategy for the enantioselective synthesis of (2S,3R)-3-phenylglycidate methyl ester (PGM), a key intermediate for production of a potent anticancer drug Taxol®. An organic-aqueous biphasic system was employed to reduce spontaneous hydrolysis of the substrate PGM and isooctane was found to be the most suitable organic solvent. The temperature and pH optima of the whole cell-mediated bioreaction were 40 °C and 6.0, respectively. Under these reaction conditions, the enantiomeric excess (ee(s)) of (2S,3R)-PGM recovered was greater than 99 % at approximately 50 % conversion. The total substrate loading in batch reaction could reach 600 mM. By using whole cells of Enterobacter sp. ECU1107, (2S,3R)-PGM was successfully prepared in decagram scale in a 1.0-l mechanically stirred reactor, affording the chiral epoxy ester in >99 % ee s and 43.5 % molar yield based on the initial load of racemic substrate.

  16. The absolute configuration of (2S,4S)- and (2R,4R)-2-tert-butyl-4-methyl-3-(4-tolylsulfonyl)-1,3-oxazolidine-4-carbaldehyde.

    PubMed

    Flock, Susanne; Bruhn, Clemens; Fink, Heinrich; Frauenrath, Herbert

    2006-02-01

    The title enantiomorphic compounds, C16H23NO4S, have been obtained in an enantiomerically pure form by crystallization from a diastereomeric mixture either of (2S,4S)- and (2R,4S)- or of (2R,4R)- and (2S,4R)-2-tert-butyl-4-methyl-3-(4-tolylsulfonyl)-1,3-oxazolidine-4-carbaldehyde. These mixtures were prepared by an aziridination rearrangement process starting with (S)- or (R)-2-tert-butyl-5-methyl-4H-1,3-dioxine. The crystal structures indicate an envelope conformation of the oxazolidine moiety for both compounds.

  17. Preparation of orthogonally protected (2S, 3R)-2-amino-3-methyl-4-phosphonobutyric acid (Pmab) as a phosphatase–stable phosphothreonine mimetic and its use in the synthesis of Polo–box domain–binding peptides

    PubMed Central

    Liu, Fa; Park, Jung-Eun; Lee, Kyung S.; Burke, Terrence R.

    2014-01-01

    Reported herein is the first stereoselective synthesis of (2S,3R)-4-[bis-(tert-butyloxy)phosphinyl]-2-[(9H-fluoren-9-ylmethoxy)carbonyl]amino-3-methylbutanoic acid [(N-Fmoc, O,O-(bis-(tert-butyl))-Pmab, 4] as a hydrolytically-stable phosphothreonine mimetic bearing orthogonal protection compatible with standard solid-phase protocols. The synthetic approach used employs Evans’ oxazolidinone for chiral induction. Also presented is the application of 4 in the solid-phase synthesis of polo-like kinase 1 (Plk1) polo box domain (PBD)-binding peptides. These Pmab-containing peptides retain PBD binding efficacy similar to a parent pThr containing peptide. Reagent 4 should be a highly useful reagent for the preparation of signal transduction-directed peptides. PMID:24954959

  18. (3,3-Difluoro-pyrrolidin-1-yl)-[(2S,4S)-(4-(4-pyrimidin-2-yl-piperazin-1-yl)-pyrrolidin-2-yl]-methanone: A potent, selective, orally active dipeptidyl peptidase IV inhibitor

    SciTech Connect

    Ammirati, Mark J.; Andrews, Kim M.; Boyer, David D.; Brodeur, Anne M.; Danley, Dennis E.; Doran, Shawn D.; Hulin, Bernard; Liu, Shenping; McPherson, R. Kirk; Orena, Stephen J.; Parker, Janice C.; Polivkova, Jana; Qiu, Xiayang; Soglia, Carolyn B.; Treadway, Judith L.; VanVolkenburg, Maria A.; Wilder, Donald C.; Piotrowski, David W.; Pfizer

    2010-10-01

    A series of 4-substituted proline amides was synthesized and evaluated as inhibitors of dipeptidyl pepdidase IV for the treatment of type 2 diabetes. (3,3-Difluoro-pyrrolidin-1-yl)-[(2S,4S)-(4-(4-pyrimidin-2-yl-piperazin-1-yl)-pyrrolidin-2-yl]-methanone (5) emerged as a potent (IC{sub 50} = 13 nM) and selective compound, with high oral bioavailability in preclinical species and low plasma protein binding. Compound 5, PF-00734200, was selected for development as a potential new treatment for type 2 diabetes.

  19. Phase diagrams of the sections As/sub 2/S/sub 3/-Tl/sub 3/AsS/sub 4/, Tl/sub 3/AsS/sub 4/-S, and Tl/sub 3/AsS/sub 4/-Tl/sub 2/S of the ternary system As-Tl-S

    SciTech Connect

    Vorob'ev, Yu.I.; Velikova, N.G.; Kirilenko, V.V.; Shchelokov, R.N.

    1987-12-01

    Using DTA and XPA methods, microstructural investigations, and microhardness measurements, phase diagrams of the quasibinary sections As/sub 2/S/sub 3/-Tl/sub 3/AsS/sub 4/, Tl/sub 3/AsS/sub 4/-S, and Tl/sub 3/AsS/sub 4/-Tl/sub 2/S, are characterized by five ternary compounds Tl/sub 3/As/sub 5/S/sub 10/, Tl/sub 9/As/sub 5/S/sub 15/, Tl/sub 9/As/sub 3/S/sub 13/, Tl/sub 3/AsS/sub 6/, and Tl/sub 8/As/sub 2/S/sub 9/, which decompose by peritectic reactions at 198, 307, 408, 362, and 318/degree/C, respectively. Interplanar spacings and line intensities are given for the detected compounds. Glass formation is considered in the Tl-As-S system.

  20. Phase Transition and Second Harmonic Generation in Thiophosphates Ag2Cd(P2S6) and AgCd3(PS4)S2 Containing Two Second-Order Jahn-Teller Distorted Cations.

    PubMed

    Fan, Yu-Hang; Jiang, Xiao-Ming; Liu, Bin-Wen; Li, Shu-Fang; Guo, Wei-Huan; Zeng, Hui-Yi; Guo, Guo-Cong; Huang, Jin-Shun

    2017-01-03

    Two new phases in the Ag-Cd-P-S system containing two second-order Jahn-Teller (SOJT) distorted d(10) cations (Cd(2+) and Ag(+)), namely, Ag2Cd(P2S6) (1) and AgCd3(PS4)S2 (2), are obtained via medium-temperature solid-state synthesis. Compound 1 exhibits a two-dimensional layered structure and undergoes a first-order structural phase transition at approximately 280 °C. This outcome can be ascribed to the significant mismatch in the expansion coefficients between Cd-S (Ag-S) and P-P (P-S) bonds evaluated through bond valence theory. The three-dimensional non-centrosymmetric (NCS) framework of 2 is constructed by two types of tetrahedral layers consisting of corner-shared CdS4, AgS4, and PS4 tetrahedra. Compound 2 exhibits second harmonic generation (SHG) intensity of 0.45 times that of commercial AgGaS2 (AGS) at a laser irradiation of 1.85 μm and an optical band gap of 2.56 eV, and no intrinsic vibrational absorption of chemical bonds is observed in the range of 2.5-18.2 μm. Both phase transition in 1 and SHG properties in 2 are closely related to the SOJT distorted d(10) cations and diverse phosphorus-sulfur polyanions (PaSb)(n-), which together can easily result in NCS distorted structures and interesting properties.

  1. Return of the lysergamides. Part II: Analytical and behavioural characterization of N(6) -allyl-6-norlysergic acid diethylamide (AL-LAD) and (2'S,4'S)-lysergic acid 2,4-dimethylazetidide (LSZ).

    PubMed

    Brandt, Simon D; Kavanagh, Pierce V; Westphal, Folker; Elliott, Simon P; Wallach, Jason; Colestock, Tristan; Burrow, Timothy E; Chapman, Stephen J; Stratford, Alexander; Nichols, David E; Halberstadt, Adam L

    2017-01-01

    Lysergic acid N,N-diethylamide (LSD) is perhaps one of the most intriguing psychoactive substances known and numerous analogs have been explored to varying extents in previous decades. In 2013, N(6) -allyl-6-norlysergic acid diethylamide (AL-LAD) and (2'S,4'S)-lysergic acid 2,4-dimethylazetidide (LSZ) appeared on the 'research chemicals'/new psychoactive substances (NPS) market in both powdered and blotter form. This study reports the analytical characterization of powdered AL-LAD and LSZ tartrate samples and their semi-quantitative determination on blotter paper. Included in this study was the use of nuclear magnetic resonance (NMR) spectroscopy, gas chromatography-mass spectrometry (GC-MS), low and high mass accuracy electrospray MS(/MS), high performance liquid chromatography diode array detection and GC solid-state infrared analysis. One feature shared by serotonergic psychedelics, such as LSD, is the ability to mediate behavioural responses via activation of 5-HT2A receptors. Both AL-LAD and LSZ displayed LSD-like responses in male C57BL/6 J mice when employing the head-twitch response (HTR) assay. AL-LAD and LSZ produced nearly identical inverted-U-shaped dose-dependent effects, with the maximal responses occurring at 200 µg/kg. Analysis of the dose responses by nonlinear regression confirmed that LSZ (ED50  = 114.2 nmol/kg) was equipotent to LSD (ED50  = 132.8 nmol/kg) in mice, whereas AL-LAD was slightly less potent (ED50  = 174.9 nmol/kg). The extent to which a comparison in potency can be translated directly to humans requires further investigation. Chemical and pharmacological data obtained from NPS may assist research communities that are interested in various aspects related to substance use and forensic identification. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Effects of collision energy and rotational quantum number on stereodynamics of the reactions: H(2S) + NH( υ = 0, j = 0, 2, 5, 10)→N(4S) + H2

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Yu, Yong-Jiang; Zhao, Gang; Yang, Chuan-Lu

    2016-08-01

    The stereodynamical properties of H(2S) + NH(v = 0, j = 0, 2, 5, 10) → N(4S) + H2 reactions are studied in this paper by using the quasi-classical trajectory (QCT) method with different collision energies on the double many-body expansion (DMBE) potential energy surface (PES) (Poveda L A and Varandas A J C 2005 Phys. Chem. Chem. Phys. 7 2867). In a range of collision energy from 2 to 20 kcal/mol, the vibrational rotational quantum numbers of the NH molecules are specifically investigated on v = 0 and j = 0, 2, 5, 10 respectively. The distributions of P(θ r ), P(ϕ r ), P(θ r ,ϕ r ), (2π/σ)(dσ 00/dω t ) differential cross-section (DCSs) and integral cross-sections(ICSs) are calculated. The ICSs, computed for collision energies from 2 kcal/mol to 20 kcal/mol, for the ground state are in good agreement with the cited data. The results show that the reagent rotational quantum number and initial collision energy both have a significant effect on the distributions of the k - j ‧, the k - k ‧- j ‧, and the k - k ‧ correlations. In addition, the DCS is found to be susceptible to collision energy, but it is not significantly affected by the rotational excitation of reagent. Project supported by the Natural Science Foundation of Shandong Province, China (Grant No. 2016ZRB01066) and the University Student’s Science and Technology Innovation Fund of Ludong University, China (Grant No. 131007).

  3. Discovery of (2S,3R)-N-[2-(pyridin-3-ylmethyl)-1-azabicyclo[2.2.2]oct-3-yl]benzo[b]furan-2-carboxamide (TC-5619), a selective α7 nicotinic acetylcholine receptor agonist, for the treatment of cognitive disorders.

    PubMed

    Mazurov, Anatoly A; Kombo, David C; Hauser, Terry A; Miao, Lan; Dull, Gary; Genus, John F; Fedorov, Nikolai B; Benson, Lisa; Sidach, Serguei; Xiao, Yunde; Hammond, Philip S; James, John W; Miller, Craig H; Yohannes, Daniel

    2012-11-26

    (2S,3R)-N-[2-(Pyridin-3-ylmethyl)-1-azabicyclo[2.2.2]oct-3-yl]benzo[b]furan-2-carboxamide (7a, TC-5619), a novel selective agonist of the α7 neuronal nicotinic acetylcholine receptor, has been identified as a promising drug candidate for the treatment of cognitive impairment associated with neurological disorders. 7a demonstrated more than a thousand-fold separation between the affinities for the α7 and α4β2 receptor subtypes and had no detectable effects on muscle or ganglionic nicotinic receptor subtypes, indicating a marked selectivity for the central nervous system over the peripheral nervous system. Results obtained from homology modeling and docking explain the observed selectivity. 7a had positive effects across cognitive, positive, and negative symptoms of schizophrenia in animal models and was additive or synergistic with the antipsychotic clozapine. Compound 7a, as an augmentation therapy to the standard treatment with antipsychotics, demonstrated encouraging results on measures of negative symptoms and cognitive dysfunction in schizophrenia and was well tolerated in a phase II clinical proof of concept trial in patients with schizophrenia.

  4. In vitro bioactivation of a selective estrogen receptor modulator (2S,3R)-(+)-3-(3-hydroxyphenyl)-2-[4-(2-pyrrolidin-1-ylethoxy)phenyl]-2,3-dihydro-1,4-benzoxathiin-6-ol (I) in liver microsomes: formation of adenine adducts.

    PubMed

    Li, Ying; Doss, George A; Li, Yan; Chen, Qing; Tang, Wei; Zhang, Zhoupeng

    2012-11-19

    As part of our efforts to develop safer selective estrogen receptor modulators (SERMs), compound I {(2S,3R)-(+)-3-(3-hydroxyphenyl)-2-[4-(2-pyrrolidin-1-ylethoxy)-phenyl]-2,3-dihydro-1,4-benzoxathiin-6-ol} was previously identified as a lead for further development. Subsequent studies showed that compound I is genotoxic in both in vitro Chinese hamster ovary (CHO) cells and in vivo mouse studies. To better understand the possible mechanisms for the observed genetoxicity effects, in vitro incubations of I with liver microsomes of human, monkey, and mouse in the presence of adenine were performed, which led to the detection of five adenine adducts. The formation of these adducts was NADPH-dependent, suggesting the involvement of oxidative bioactivation catalyzed by cytochrome P450 enzymes. The mechanism for the formation of the major adenine adduct (A1) involves the formation of a reactive ring-opened para-quinone intermediate. The formation of four other adenine adducts may involve the formation of a reactive epoxide or ortho-quinone intermediate. Furthermore, incubations of compound I with human hepatocytes showed dose-dependent DNA damages in Comet assays. All of the above suggest that some reactive metabolites of compound I, formed through bioactivation mechanisms, have a potential to interact with DNA molecules in vitro and in vivo. This may be one of the causes of the genotoxicity observed preclinically both in vitro and in vivo. This case study demonstrated an approach using in vitro DNA trapping assays for assessing the genotoxicity potential of drug candidates.

  5. Crystal structure of racemic [(1R,2S,3R,4S,6S)-2,6-bis­(furan-2-yl)-4-hy­droxy-4-(thio­phen-2-yl)cyclo­hexane-1,3-di­yl]bis­(thio­phen-2-yl­methanone)

    PubMed Central

    Çelik, Ísmail; Ersanlı, Cem Cüneyt; Akkurt, Mehmet; Gezegen, Hayrettin; Köseoğlu, Rahmi

    2016-01-01

    In the title compound, C28H22O5S3, the central cyclo­hexane ring adopts a chair conformation. The atoms of the furan ring attached to the 6-position of the central cyclo­hexane ring are disordered over two sets of sites with occupancies of 0.832 (5) and 0.168 (5). The hy­droxy group is disordered over two positions (at the 4- and 6-positions of the cyclo­hexane ring) in the ratio 0.832 (5):0.168 (5). In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds and C—H⋯π inter­actions, forming layers parallel to (100). PMID:27555944

  6. Crystal structure of racemic [(1R,2S,3R,4S,6S)-2,6-bis-(furan-2-yl)-4-hy-droxy-4-(thio-phen-2-yl)cyclo-hexane-1,3-di-yl]bis-(thio-phen-2-yl-methanone).

    PubMed

    Çelik, Ísmail; Ersanlı, Cem Cüneyt; Akkurt, Mehmet; Gezegen, Hayrettin; Köseoğlu, Rahmi

    2016-07-01

    In the title compound, C28H22O5S3, the central cyclo-hexane ring adopts a chair conformation. The atoms of the furan ring attached to the 6-position of the central cyclo-hexane ring are disordered over two sets of sites with occupancies of 0.832 (5) and 0.168 (5). The hy-droxy group is disordered over two positions (at the 4- and 6-positions of the cyclo-hexane ring) in the ratio 0.832 (5):0.168 (5). In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds and C-H⋯π inter-actions, forming layers parallel to (100).

  7. Stereoselective cathodic synthesis of 8-substituted (1R,3R,4S)-menthylamines

    PubMed Central

    Edinger, Carolin; Kulisch, Jörn

    2015-01-01

    Summary The electrochemical generation of menthylamines from the corresponding menthone oximes equipped with an additional substituent in position 8 is described. Due to 1,3-diaxial interactions a pronounced diastereoselectivity for the menthylamines is found. PMID:25815083

  8. Stereoselective cathodic synthesis of 8-substituted (1R,3R,4S)-menthylamines.

    PubMed

    Edinger, Carolin; Kulisch, Jörn; Waldvogel, Siegfried R

    2015-01-01

    The electrochemical generation of menthylamines from the corresponding menthone oximes equipped with an additional substituent in position 8 is described. Due to 1,3-diaxial interactions a pronounced diastereoselectivity for the menthylamines is found.

  9. Binding H2, N2, H-, and BH3 to transition-metal sulfur sites: synthesis and properties of [RuL(PR3)(N2Me2S2)] Complexes (L=eta2-H2, H-, BH3; R=Cy, iPr).

    PubMed

    Sellmann, D; Hille, A; Heinemann, F W; Moll, M; Reiher, M; Hess, B A; Bauer, W

    2004-09-06

    The reactions of [Ru(N(2))(PR(3))('N(2)Me(2)S(2)')] ['N(2)Me(2)S(2)'=1,2-ethanediamine-N,N'-dimethyl-N,N'-bis(2-benzenethiolate)(2-)] [1 a (R=iPr), 1 b (R=Cy)] and [micro-N(2)[Ru(N(2))(PiPr(3))('N(2)Me(2)S(2)')](2)] (1 c) with H(2), NaBH(4), and NBu(4)BH(4), intended to reduce the N(2) ligands, led to substitution of N(2) and formation of the new complexes [Ru(H(2))(PR(3))('N(2)Me(2)S(2)')] [2 a (R=iPr), 2 b (R=Cy)], [Ru(BH(3))(PR(3))('N(2)Me(2)S(2)')] [3 a (R=iPr), 3 b (R=Cy)], and [Ru(H)(PR(3))('N(2)Me(2)S(2)')](-) [4 a (R=iPr), 4 b (R=Cy)]. The BH(3) and hydride complexes 3 a, 3 b, 4 a, and 4 b were obtained subsequently by rational synthesis from 1 a or 1 b and BH(3).THF or LiBEt(3)H. The primary step in all reactions probably is the dissociation of N(2) from the N(2) complexes to give coordinatively unsaturated [Ru(PR(3))('N(2)Me(2)S(2)')] fragments that add H(2), BH(4) (-), BH(3), or H(-). All complexes were completely characterized by elemental analysis and common spectroscopic methods. The molecular structures of [Ru(H(2))(PR(3))('N(2)Me(2)S(2)')] [2 a (R=iPr), 2 b (R=Cy)], [Ru(BH(3))(PiPr(3))('N(2)Me(2)S(2)')] (3 a), [Li(THF)(2)][Ru(H)(PiPr(3))('N(2)Me(2)S(2)')] ([Li(THF)(2)]-4 a), and NBu(4)[Ru(H)(PCy(3))('N(2)Me(2)S(2)')] (NBu(4)-4 b) were determined by X-ray crystal structure analysis. Measurements of the NMR relaxation time T(1) corroborated the eta(2) bonding mode of the H(2) ligands in 2 a (T(1)=35 ms) and 2 b (T(1)=21 ms). The H,D coupling constants of the analogous HD complexes HD-2 a ((1)J(H,D)=26.0 Hz) and HD-2 b ((1)J(H,D)=25.9 Hz) enabled calculation of the H--D distances, which agreed with the values found by X-ray crystal structure analysis (2 a: 92 pm (X-ray) versus 98 pm (calculated), 2 b: 99 versus 98 pm). The BH(3) entities in 3 a and 3 b bind to one thiolate donor of the [Ru(PR(3))('N(2)Me(2)S(2)')] fragment and through a B-H-Ru bond to the Ru center. The hydride complex anions 4 a and 4 b are extremely Brønsted basic and are

  10. The hydrogen permeability of Pd{sub 4}S

    SciTech Connect

    O'Brien, Casey; Miller, James; Gellman, Andrew; Morreale, Bryan

    2011-04-01

    Hydrogen permeates rapidly through pure Pd membranes, but H{sub 2}S, a common minor component in hydrogen-containing streams, produces a Pd{sub 4}S film on the Pd surface that severely retards hydrogen permeation. Hydrogen still permeates through the bi-layered Pd{sub 4}S/Pd structure, indicating that the Pd{sub 4}S surface is active for H{sub 2} dissociation; the low hydrogen permeability of the Pd4S film is responsible for the decreased rate of hydrogen transport. In this work, the hydrogen permeability of Pd{sub 4}S was determined experimentally in the 623-773 K temperature range. Bi-layered Pd{sub 4}S/Pd foils were produced by exposing pure Pd foils to H{sub 2}S. H{sub 2} fluxes through the bi-layered Pd{sub 4}S/Pd foils were measured during exposure to both pure H{sub 2} and a 1000 ppm H{sub 2}S in H{sub 2} gas mixture. Our results show that H{sub 2}S slows hydrogen permeation through Pd mainly by producing a Pd{sub 4}S film on the Pd surface that is roughly an order-of-magnitude less permeable to hydrogen (k{sub Pd{sub 4}S} = 10{sup −7.5} exp(−0.22 eV/k{sub B}T) molH{sub 2}/m/s/Pa{sup 1/2}) than pure Pd. The presence of H{sub 2}S in the gas stream results in greater inhibition of hydrogen transport than can be explained by the very low permeability of Pd{sub 4}S. H{sub 2}S may block H2 dissociation sites at the Pd{sub 4}S surface.

  11. Histone H3R2 symmetric dimethylation and histone H3K4 trimethylation are tightly correlated in eukaryotic genomes

    PubMed Central

    Yuan, Chih-Chi; Matthews, Adam G.W.; Jin, Yi; Chen, Chang Feng; Chapman, Brad A.; Ohsumi, Toshiro K.; Glass, Karen C.; Kutateladze, Tatiana G.; Borowsky, Mark L.; Struhl, Kevin; Oettinger, Marjorie A.

    2012-01-01

    Summary The preferential in vitro interaction of the PHD finger of RAG2, a subunit of the V(D)J recombinase, with histone H3 tails simultaneously trimethylated at lysine 4 and symmetrically dimethylated at arginine 2 (H3R2me2sK4me3) predicted the existence of the previously unknown histone modification, H3R2me2s. Here, we report the in vivo identification of H3R2me2s . Consistent with the binding specificity of the RAG2 PHD finger, high levels of H3R2me2sK4me3 are found at antigen receptor gene segments ready for rearrangement. However, this double modification is much more general; it is conserved throughout eukaryotic evolution. In mouse, H3R2me2s is tightly correlated with H3K4me3 at active promoters throughout the genome. Mutational analysis in S. cerevisiae reveals that deposition of H3R2me2s requires the same Set1 complex that deposits H3K4me3. Our work suggests that H3R2me2sK4me3, not simply H3K4me3 alone, is the mark of active promoters, and that factors that recognize H3K4me3 will have their binding modulated by their preference for H3R2me2s. PMID:22720264

  12. (3R,4S)-3,4-Isopropylidenedioxy-5-phenylsulfonylmethyl-3,4-dihydro-2H-pyrrole 1-oxide

    PubMed Central

    Flores, Mari Fe; Garcia, P.; M. Garrido, Narciso; Sanz, Francisca; Diez, David

    2011-01-01

    The title compound, C14H17NO5S, was prepared by oxidation of (2R,3S,4R)-2-phenyl­sulfonyl­methyl-1-hy­droxy-3,4-iso­pro­pyl­idene­dioxy­pyrrolidine. Its crystal structure confirms unequivocally its configuration. Two inter­molecular C—H⋯O inter­actions help to establish the packing. PMID:21754431

  13. Metamodels for Planar 3R Workspace Optimization.

    SciTech Connect

    Turner, C. J.

    2002-01-01

    Robotic workspace optimization is a central element of robot system design. To formulate the optimization problem, the complex relationships between design variables, tuning parameters, and performance indices need to be accurately and efficiently represented. The nature of the relationships suggests that metamodels, or models of the models, should be used to derive suitable objective functions. A comparison of two metamodeling techniques for robotic workspace optimization problems for several trial cases suggests that non-uniform rational B-spline models, derived from computer graphics and computer-aided design techniques, are as suitable as response surface models to solve planar 3R workspace optimization problems. Promising nonlinear modeling results with B-spline models suggest future work is justified and performance gains can be realized.

  14. Biotransformation studies of textile dye Remazol Orange 3R.

    PubMed

    Surwase, Swati V; Deshpande, Krutika K; Phugare, Swapnil S; Jadhav, Jyoti P

    2013-08-01

    In the present study, biotransformation of Remazol Orange 3R (RO3R) was studied using well-known bacterial isolate Pseudomonas aeruginosa strain BCH. The dye was decolorized up to 98 % within 15 min. The induction in the level of various oxidoreductive enzymes viz. laccase, tyrosinase, veratryl alcohol oxidase and DCIP reductase were observed in the cells obtained after decolorization of RO3R, which supports their role in decolorization. The metabolites of RO3R obtained after biodegradation were identified and characterized by various analytical techniques viz, HPLC, FTIR, and GC-MS. The RO3R was transformed to the N-(7 amino 8 hydroxy-napthalen-2yl) actamide (m/z, 198), Acetamide (m/z, 59) and Napthalen-1-ol (m/z, 144).

  15. The 3R polymorph of CaSi{sub 2}

    SciTech Connect

    Nedumkandathil, Reji; Benson, Daryn E.; Grins, Jekabs; Spektor, Kristina; Häussermann, Ulrich

    2015-02-15

    The Zintl phase CaSi{sub 2} commonly occurs in the 6R structure where puckered hexagon layers of Si atoms are stacked in an AA′BB′CC′ fashion. In this study we show that sintering of CaSi{sub 2} in a hydrogen atmosphere (30 bar) at temperatures between 200 and 700 °C transforms 6R-CaSi{sub 2} quantitatively into 3R-CaSi{sub 2}. In the 3R polymorph (space group R-3m (no. 166), a=3.8284(1), c=15.8966(4), Z=3) puckered hexagon layers are stacked in an ABC fashion. The volume per formula unit is about 3% larger compared to 6R-CaSi{sub 2}. First principles density functional calculations reveal that 6R and 3R-CaSi{sub 2} are energetically degenerate at zero Kelvin. With increasing temperature 6R-CaSi{sub 2} stabilizes over 3R because of its higher entropy. This suggests that 3R-CaSi{sub 2} should revert to 6R at elevated temperatures, which however is not observed up to 800 °C. 3R-CaSi{sub 2} may be stabilized by small amounts of incorporated hydrogen and/or defects. - Graphical abstract: The common 6R form of CaSi{sub 2} can be transformed quantitatively into 3R-CaSi{sub 2} upon sintering in a hydrogen atmosphere. - Highlights: • Quantitative and reproducible bulk synthesis of the rare 3R polymorph of CaSi{sub 2}. • Clarification of the energetic relation between 3R and conventional 6R form. • 3R-CaSi{sub 2} is presumably stabilized by small amounts of incorporated hydrogen and/or defects.

  16. The Italian stroke-app: ICTUS3R.

    PubMed

    Baldereschi, Marzia; Di Carlo, Antonio; Piccardi, Benedetta; Inzitari, Domenico

    2016-06-01

    Any strategy to reduce stroke burden involves crucial inputs from individuals (risk reduction, rapid recognition and response to symptoms onset) which imply a certain level of stroke knowledge. Health-related applications (apps) have been identified as a novel platform for dissemination of health information to the public. Only few apps about stroke are currently available with scientifically valid information, none of them are available in Italian. We developed the first and only Italian stroke app, ICTUS3R. We also pilot tested ICTUS3R in terms of its usage during the first 12 months following release (October 30, 2014). ICTUS3R was developed in collaboration with communication experts, stroke leaders and web producers. ICTUS3R was pilot tested in terms of number and distribution of downloads. Data about 1 year usage were anonymously collected from ICTUS 3R release on October 30, 2014. ICTUS3R includes a stroke screening tool, information how to react in case of suspected stroke, and information about risk factors including personal stroke risk calculator. ICTUS 3R web site was visited 36,242 times. Mean session duration was over 2 min. The 48 % of downloads were by individuals aged 25-44 years, 12 % by individuals ≥55 years. ICTUS3R downloads were distributed across all the Italian provinces, in varying proportions. The 4.3 % of downloads were done outside Italy. ICTUS3R can be an important contribution to stroke management and prevention, it proved to be well received for dissemination of stroke information among Italians. Its use could contribute to reduce stroke burden in Italy.

  17. Antiausterity activity of arctigenin enantiomers: importance of (2R,3R)-absolute configuration.

    PubMed

    Awale, Suresh; Kato, Mamoru; Dibwe, Dya Fita; Li, Feng; Miyoshi, Chika; Esumi, Hiroyasu; Kadota, Shigetoshi; Tezuka, Yasuhiro

    2014-01-01

    From a MeOH extract of powdered roots of Wikstroemia indica, six dibenzyl-gamma-butyrolactone-type lignans with (2S,3S)-absolute configuration [(+)-arctigenin (1), (+)-matairesinol (2), (+)-trachelogenin (3), (+)-nortrachelogenin (4), (+)-hinokinin (5), and (+)-kusunokinin (6)] were isolated, whereas three dibenzyl-gamma-butyrolactone-type lignans with (2R,3R)-absolute configuration [(-)-arctigenin (1*), (-)-matairesinol (2*), (-)-trachelogenin (3*)] were isolated from Trachelospermum asiaticum. The in vitro preferential cytotoxic activity of the nine compounds was evaluated against human pancreatic PANC-1 cancer cells in nutrient-deprived medium (NDM), but none of the six lignans (1-6) with (2S,3S)-absolute configuration showed preferential cytotoxicity. On the other hand, three lignans (1*-3*) with (2R,3R)-absolute configuration exhibited preferential cytotoxicity in a concentration-dependent manner with PC50 values of 0.54, 6.82, and 5.85 microM, respectively. Furthermore, the effect of (-)- and (+)-arctigenin was evaluated against the activation of Akt, which is a key process in the tolerance to nutrition starvation. Interestingly, only (-)-arctigenin (1*) strongly suppressed the activation of Akt. These results indicate that the (2R,3R)-absolute configuration of (-)-enantiomers should be required for the preferential cytotoxicity through the inhibition of Akt activation.

  18. Buck-Buck- Boost Regulatr (B3R)

    NASA Astrophysics Data System (ADS)

    Mourra, Olivier; Fernandez, Arturo; Landstroem, Sven; Tonicello, Ferdinando

    2011-10-01

    In a satellite, the main function of a Power Conditioning Unit (PCU) is to manage the energy coming from several power sources (usually solar arrays and battery) and to deliver it continuously to the users in an appropriate form during the overall mission. The objective of this paper is to present an electronic switching DC-DC converter called Buck-Buck-Boost Regulator (B3R) that could be used as a modular and recurrent solution in a PCU for regulated or un- regulated 28Vsatellite power bus classes. The power conversion stages of the B3R topology are first described. Then theoretical equations and practical tests illustrate how the converter operates in term of power conversion, control loops performances and efficiency. The paper finally provides some examples of single point failure tolerant implementation using the B3R.

  19. QPSK 3R regenerator using a phase sensitive amplifier.

    PubMed

    Perentos, A; Fabbri, S; Sorokina, M; Phillips, I D; Turitsyn, S K; Ellis, A D; Sygletos, S

    2016-07-25

    A black box phase sensitive amplifier based 3R regeneration scheme is proposed for non-return to zero quadrature phase shift keyed formatted signals. Performance improvements of more than 2 dB are achieved at the presence of input phase distortion.

  20. Ultrafast transient lens spectroscopy of various C40 carotenoids: lycopene, beta-carotene, (3R,3'R)-zeaxanthin, (3R,3'R,6'R)-lutein, echinenone, canthaxanthin, and astaxanthin.

    PubMed

    Kopczynski, Matthäus; Lenzer, Thomas; Oum, Kawon; Seehusen, Jaane; Seidel, Marco T; Ushakov, Vladimir G

    2005-07-21

    The ultrafast internal conversion (IC) dynamics of seven C(40) carotenoids have been investigated at room temperature in a variety of solvents using two-color transient lens (TL) pump-probe spectroscopy. We provide comprehensive data sets for the carbonyl carotenoids canthaxanthin, astaxanthin, and-for the first time-echinenone, as well as new data for lycopene, beta-carotene, (3R,3'R)-zeaxanthin and (3R,3'R,6'R)-lutein in solvents which have not yet been investigated in the literature. Measurements were carried out to determine, how the IC processes are influenced by the conjugation length of the carotenoids, additional substituents and the polarity of the solvent. TL signals were recorded at 800 nm following excitation into the high energy edge of the carotenoid S2 band at 400 nm. For the S2 lifetime solvent-independent upper limits on the order of 100-200 fs are estimated for all carotenoids studied. The S1 lifetimes are in the picosecond range and increase systematically with decreasing conjugation length. For instance, in the sequence canthaxanthin/echinenone/beta-carotene (13/12/11 double bonds) one finds tau1 approximately 5, 7.7 and 9 ps for the S1-->S0 IC process, respectively. Hydroxyl groups not attached to the conjugated system have no apparent influence on tau1, as observed for canthaxanthin/astaxanthin (tau1 approximately 5 ps in both cases). For all carotenoids studied, tau1 is found to be insensitive to the solvent polarity. This is particularly interesting in the case of echinenone, canthaxanthin and astaxanthin, because earlier measurements for other carbonyl carotenoids like, e.g., peridinin partly showed dramatic differences. The likely presence of an intramolecular charge transfer state in the excited state manifold of C40 carbonyl carotenoids, which is stabilized in polar solvents, has obviously no influence on the measured tau1.

  1. Coupling Algorithm for Sp(3 , R) Irreducible Representations

    NASA Astrophysics Data System (ADS)

    St. Germaine-Fuller, James F.; McCoy, Anna E.; Caprio, Mark A.

    2015-04-01

    The nuclear symplectic model based on Sp(3 , R) - the smallest algebra that contains both the shell model Hamiltonian and the rotor algebra - connects the microscopic shell model to collective rotational behavior and naturally extends the Elliot SU(3) model to multiple shells. However, Sp(3 , R) is only an approximate symmetry of the nucleus which can be broken by spin-orbit interactions, tensor force interactions, and pairing. The Hamiltonians in most physical situations will break Sp(3 , R) symmetry, causing their eigenstates to become linear combinations of symplectic irreducible representations (irreps). Calculations with those eigenstates will then involve multiple irreps. We report a computer algorithm for enumerating the irreps that arise from the coupling of two symplectice irreps and evaluating their multiplicities in the product. This should assist in performing such multi-irrep calculations and facilitate computing symplectic coupling coefficients. Supported by the US NSF under Grant NSF-PHY05-52843, the US DOE under Grant DE-FG02-95ER-40934, and the Research Corporation for Science Advancement under a Cottrell Scholar Award.

  2. (3R,4S)-3,4-Isopropyl­idenedioxy-3,4-dihydro-2H-pyrrole 1-oxide

    PubMed Central

    Flores, Mari Fe; Garcia, Pilar; M. Garrido, Narciso; Sanz, Francisca; Diez, David

    2011-01-01

    The title compound C7H11NO3 was prepared by intra­molecular nucleophilic displacement of 2,3-O-iso-propyl­idene-d-erythronolactol. There are two mol­ecules in the asymmetric unit, which are related by a pseudo-inversion centre. The crystal structure determination confirms unequivocally the configuration of the chiral centres as 3S,4R. In the crystal structure, inter­molecular C—H⋯O inter­actions link the mol­ecules (into infinite zigzag chains along the a axis. PMID:21754432

  3. Measurement of the branching fractions for ψ(2S)-->e+e- and ψ(2S)-->μ+μ-

    NASA Astrophysics Data System (ADS)

    Aubert, B.; Boutigny, D.; Gaillard, J.-M.; Hicheur, A.; Karyotakis, Y.; Lees, J. P.; Robbe, P.; Tisserand, V.; Palano, A.; Pompili, A.; Chen, G. P.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Reinertsen, P. L.; Stugu, B.; Abrams, G. S.; Borgland, A. W.; Breon, A. B.; Brown, D. N.; Button-Shafer, J.; Cahn, R. N.; Clark, A. R.; Gill, M. S.; Gritsan, A. V.; Groysman, Y.; Jacobsen, R. G.; Kadel, R. W.; Kadyk, J.; Kerth, L. T.; Kolomensky, Yu. G.; Kral, J. F.; Leclerc, C.; Levi, M. E.; Liu, T.; Lynch, G.; Oddone, P. J.; Perazzo, A.; Pripstein, M.; Roe, N. A.; Romosan, A.; Ronan, M. T.; Shelkov, V. G.; Telnov, A. V.; Wenzel, W. A.; Bright-Thomas, P. G.; Harrison, T. J.; Hawkes, C. M.; Knowles, D. J.; O'Neale, S. W.; Penny, R. C.; Watson, A. T.; Watson, N. K.; Deppermann, T.; Goetzen, K.; Koch, H.; Kunze, M.; Lewandowski, B.; Peters, K.; Schmuecker, H.; Steinke, M.; Andress, J. C.; Barlow, N. R.; Bhimji, W.; Chevalier, N.; Clark, P. J.; Cottingham, W. N.; de Groot, N.; Dyce, N.; Foster, B.; McFall, J. D.; Wallom, D.; Wilson, F. F.; Abe, K.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Thiessen, D.; Jolly, S.; McKemey, A. K.; Tinslay, J.; Blinov, V. E.; Bukin, A. D.; Bukin, D. A.; Buzykaev, A. R.; Golubev, V. B.; Ivanchenko, V. N.; Korol, A. A.; Kravchenko, E. A.; Onuchin, A. P.; Salnikov, A. A.; Serednyakov, S. I.; Skovpen, Yu. I.; Telnov, V. I.; Yushkov, A. N.; Best, D.; Lankford, A. J.; Mandelkern, M.; McMahon, S.; Stoker, D. P.; Ahsan, A.; Arisaka, K.; Buchanan, C.; Chun, S.; Branson, J. G.; Macfarlane, D. B.; Prell, S.; Rahatlou, Sh.; Raven, G.; Sharma, V.; Campagnari, C.; Dahmes, B.; Hart, P. A.; Kuznetsova, N.; Levy, S. L.; Long, O.; Lu, A.; Richman, J. D.; Verkerke, W.; Witherell, M.; Yellin, S.; Beringer, J.; Dorfan, D. E.; Eisner, A. M.; Grillo, A. A.; Grothe, M.; Heusch, C. A.; Johnson, R. P.; Lockman, W. S.; Pulliam, T.; Sadrozinski, H.; Schalk, T.; Schmitz, R. E.; Schumm, B. A.; Seiden, A.; Turri, M.; Walkowiak, W.; Williams, D. C.; Wilson, M. G.; Chen, E.; Dubois-Felsmann, G. P.; Dvoretskii, A.; Hitlin, D. G.; Metzler, S.; Oyang, J.; Porter, F. C.; Ryd, A.; Samuel, A.; Weaver, M.; Yang, S.; Zhu, R. Y.; Devmal, S.; Geld, T. L.; Jayatilleke, S.; Mancinelli, G.; Meadows, B. T.; Sokoloff, M. D.; Barillari, T.; Bloom, P.; Dima, M. O.; Fahey, S.; Ford, W. T.; Johnson, D. R.; Nauenberg, U.; Olivas, A.; Rankin, P.; Roy, J.; Sen, S.; Smith, J. G.; van Hoek, W. C.; Wagner, D. L.; Blouw, J.; Harton, J. L.; Krishnamurthy, M.; Soffer, A.; Toki, W. H.; Wilson, R. J.; Zhang, J.; Brandt, T.; Brose, J.; Colberg, T.; Dickopp, M.; Dubitzky, R. S.; Hauke, A.; Maly, E.; Müller-Pfefferkorn, R.; Otto, S.; Schubert, K. R.; Schwierz, R.; Spaan, B.; Wilden, L.; Bernard, D.; Bonneaud, G. R.; Brochard, F.; Cohen-Tanugi, J.; Ferrag, S.; Roussot, E.; T'Jampens, S.; Thiebaux, Ch.; Vasileiadis, G.; Verderi, M.; Anjomshoaa, A.; Bernet, R.; Khan, A.; Lavin, D.; Muheim, F.; Playfer, S.; Swain, J. E.; Falbo, M.; Borean, C.; Bozzi, C.; Dittongo, S.; Piemontese, L.; Treadwell, E.; Anulli, F.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Falciai, D.; Finocchiaro, G.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Xie, Y.; Zallo, A.; Bagnasco, S.; Buzzo, A.; Contri, R.; Crosetti, G.; Lo Vetere, M.; Macri, M.; Monge, M. R.; Passaggio, S.; Pastore, F. C.; Patrignani, C.; Pia, M. G.; Robutti, E.; Santroni, A.; Morii, M.; Bartoldus, R.; Hamilton, R.; Mallik, U.; Cochran, J.; Crawley, H. B.; Fischer, P.-A.; Lamsa, J.; Meyer, W. T.; Rosenberg, E. I.; Grosdidier, G.; Hast, C.; Höcker, A.; Lacker, H. M.; Laplace, S.; Lepeltier, V.; Lutz, A. M.; Plaszczynski, S.; Schune, M. H.; Trincaz-Duvoid, S.; Wormser, G.; Bionta, R. M.; Brigljević, V.; Lange, D. J.; Mugge, M.; van Bibber, K.; Wright, D. M.; Carroll, M.; Fry, J. R.; Gabathuler, E.; Gamet, R.; George, M.; Kay, M.; Payne, D. J.; Sloane, R. J.; Touramanis, C.; Aspinwall, M. L.; Bowerman, D. A.; Dauncey, P. D.; Egede, U.; Eschrich, I.; Gunawardane, N. J.; Nash, J. A.; Sanders, P.; Smith, D.; Azzopardi, D. E.; Back, J. J.; Dixon, P.; Harrison, P. F.; Potter, R. J.; Shorthouse, H. W.; Strother, P.; Vidal, P. B.; Williams, M. I.; Cowan, G.; George, S.; Green, M. G.; Kurup, A.; Marker, C. E.; McGrath, P.; McMahon, T. R.; Ricciardi, S.; Salvatore, F.; Scott, I.; Vaitsas, G.; Brown, D.; Davis, C. L.; Allison, J.; Barlow, R. J.; Boyd, J. T.; Forti, A. C.; Fullwood, J.; Jackson, F.; Lafferty, G. D.; Savvas, N.; Simopoulos, E. T.; Weatherall, J. H.; Farbin, A.; Jawahery, A.; Lillard, V.; Olsen, J.; Roberts, D. A.; Schieck, J. R.; Blaylock, G.; Dallapiccola, C.; Flood, K. T.; Hertzbach, S. S.; Kofler, R.; Koptchev, V. G.; Moore, T. B.; Staengle, H.; Willocq, S.; Brau, B.; Cowan, R.; Sciolla, G.; Taylor, F.; Yamamoto, R. K.; Milek, M.; Patel, P. M.; Palombo, F.; Bauer, J. M.; Cremaldi, L.; Eschenburg, V.; Kroeger, R.; Reidy, J.; Sanders, D. A.; Summers, D. J.; Martin, J. P.; Nief, J. Y.; Seitz, R.; Taras, P.; Zacek, V.; Nicholson, H.; Sutton, C. S.; Cavallo, N.; de Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Paolucci, P.; Piccolo, D.; Sciacca, C.; Losecco, J. M.; Alsmiller, J. R.; Gabriel, T. A.; Handler, T.; Brau, J.; Frey, R.; Iwasaki, M.; Sinev, N. B.; Strom, D.; Colecchia, F.; dal Corso, F.; Dorigo, A.; Galeazzi, F.; Margoni, M.; Michelon, G.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Torassa, E.; Voci, C.; Benayoun, M.; Briand, H.; Chauveau, J.; David, P.; de La Vaissière, Ch.; del Buono, L.; Hamon, O.; Le Diberder, F.; Leruste, Ph.; Roos, L.; Stark, J.; Versillé, S.; Manfredi, P. F.; Re, V.; Speziali, V.; Frank, E. D.; Gladney, L.; Guo, Q. H.; Panetta, J.; Angelini, C.; Batignani, G.; Bettarini, S.; Bondioli, M.; Carpinelli, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Martinez-Vidal, F.; Morganti, M.; Neri, N.; Paoloni, E.; Rama, M.; Rizzo, G.; Sandrelli, F.; Simi, G.; Triggiani, G.; Walsh, J.; Haire, M.; Judd, D.; Paick, K.; Turnbull, L.; Wagoner, D. E.; Albert, J.; Elmer, P.; Lu, C.; McDonald, K. T.; Miftakov, V.; Schaffner, S. F.; Smith, A. J.; Tumanov, A.; Varnes, E. W.; Cavoto, G.; del Re, D.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Lamanna, E.; Leonardi, E.; Mazzoni, M. A.; Morganti, S.; Piredda, G.; Safai Tehrani, F.; Serra, M.; Voena, C.; Christ, S.; Waldi, R.; Adye, T.; Franek, B.; Geddes, N. I.; Gopal, G. P.; Xella, S. M.; Aleksan, R.; de Domenico, G.; Emery, S.; Gaidot, A.; Ganzhur, S. F.; Giraud, P.-F.; de Monchenault, G. Hamel; Kozanecki, W.; Langer, M.; London, G. W.; Mayer, B.; Serfass, B.; Vasseur, G.; Yèche, Ch.; Zito, M.; Copty, N.; Purohit, M. V.; Singh, H.; Yumiceva, F. X.; Adam, I.; Anthony, P. L.; Aston, D.; Baird, K.; Berger, N.; Bloom, E.; Boyarski, A. M.; Bulos, F.; Calderini, G.; Convery, M. R.; Coupal, D. P.; Coward, D. H.; Dorfan, J.; Dunwoodie, W.; Field, R. C.; Glanzman, T.; Godfrey, G. L.; Gowdy, S. J.; Grosso, P.; Haas, T.; Himel, T.; Hryn'Ova, T.; Huffer, M. E.; Innes, W. R.; Jessop, C. P.; Kelsey, M. H.; Kim, P.; Kocian, M. L.; Langenegger, U.; Leith, D. W.; Luitz, S.; Luth, V.; Lynch, H. L.; Marsiske, H.; Menke, S.; Messner, R.; Moffeit, K. C.; Mount, R.; Muller, D. R.; O'Grady, C. P.; Perl, M.; Petrak, S.; Quinn, H.; Ratcliff, B. N.; Robertson, S. H.; Rochester, L. S.; Roodman, A.; Schietinger, T.; Schindler, R. H.; Schwiening, J.; Serbo, V. V.; Snyder, A.; Soha, A.; Spanier, S. M.; Stelzer, J.; Su, D.; Sullivan, M. K.; Tanaka, H. A.; Va'Vra, J.; Wagner, S. R.; Weinstein, A. J.; Wisniewski, W. J.; Wright, D. H.; Young, C. C.; Burchat, P. R.; Cheng, C. H.; Kirkby, D.; Meyer, T. I.; Roat, C.; Henderson, R.; Bugg, W.; Cohn, H.; Weidemann, A. W.; Izen, J. M.; Kitayama, I.; Lou, X. C.; Bianchi, F.; Bona, M.; Gamba, D.; Smol, A.; Bosisio, L.; della Ricca, G.; Lanceri, L.; Poropat, P.; Vuagnin, G.; Panvini, R. S.; Brown, C. M.; Kowalewski, R.; Roney, J. M.; Band, H. R.; Charles, E.; Dasu, S.; di Lodovico, F.; Eichenbaum, A. M.; Hu, H.; Johnson, J. R.; Liu, R.; Pan, Y.; Prepost, R.; Scott, I. J.; Sekula, S. J.; von Wimmersperg-Toeller, J. H.; Wu, S. L.; Yu, Z.; Kordich, T. M.; Neal, H.

    2002-02-01

    We measure the branching fractions of the ψ(2S) meson to the leptonic final states e+e- and μ+μ- relative to that for ψ(2S)-->J/ψπ+π-. The method uses ψ(2S) mesons produced in the decay of B mesons at the Υ(4S) resonance in a data sample collected with the BABAR detector at the Stanford Linear Accelerator Center. Using previous measurements for the ψ(2S)-->J/ψπ+π- branching fraction, we determine the e+e- and μ+μ- branching fractions to be 0.0078+/-0.0009+/-0.0008 and 0.0067+/-0.0008+/-0.0007, respectively.

  4. Evaluation of the gait performance of above-knee amputees while walking with 3R20 and 3R15 knee joints

    PubMed Central

    Taheri, AliReza; Karimi, Mohammad Taghi

    2012-01-01

    Background: The performance of the subjects with above-knee amputation is noticeably poorer than normal subjects. Various types of components have been designed to compensate their performance. Among various prosthetic components, the knee joint has great influence on the function. Two types of knee joints (3R15, 3R20) have been used broadly for above-knee prostheses. However, there is not enough research to highlight the influence of these joints on the gait performance of the subjects. Therefore, an aim of this research was to investigate the performance of the above-knee amputees while walking with 3R15 and 3R20 knee joints. Materials and Methods: 7 above-knee amputees were recruited in this research study. They were asked to walk with a comfortable speed to investigate the gait function of the subjects with 3 cameras 3D motion analysis system (Kinematrix system). The difference between the performances of the subjects with these joints was compared by use of paired t-test. Results: The results of this study showed that, the performances of the subjects with 3R20 were better than that with 3R15. The walking speed of the subjects with 3R20 was 66.7 m/min compared to 30.4 m/min (P-value = 0.045). Moreover; the symmetry of walking with 3R20 was more than that with 3R15, based on the spatio- temporal gait parameters values (P-value <0.05). Conclusion: The difference between the performances of the subjects with 3R20 and 3R15 knee joints was related to the walking speed, which improved while walking with 3R20 joint. PMID:23267378

  5. rhCSF3 accelerates the proliferation of human melanocytes in culture through binding CSF3R and the expression of CSF3R transcripts.

    PubMed

    Lu, Yan; Guo, Ze; Zhou, Mei-Hua; Li, Xue; Sun, Jie; Gong, Qing-Li; Zhu, Wen-Yuan

    2015-05-01

    Melanogenic paracrine and autocrine cytokine networks have recently been discovered in vitro between melanocytes and other types of skin cells. Granulocyte colony-stimulating factor receptor (CSF3R) controls the survival, proliferation and differentiation of many kinds of cells, including neutrophils. To understand the function of CSF3R and recombinant human granulocyte colony-stimulating factor (rhCSF3) on melanocyte proliferation, this study compared the expression of CSF3R and the effects of rhCSF3 in primary human melanocytes, neutrophils and HEL 92.1.7 cells. The results show that CSF3R is localized in the cytoplasm and on cell membranes of melanocytes and neutrophils. The percentage of CSF3R(+) melanocytes was higher than CSF3R(+) HEL 92.1.7 cells, but was lower than CSF3R(+) neutrophils. Both CSF3R mRNA and CSF3R protein levels in melanocytes were higher than in HEL 92.1.7 cells, but were lower than in neutrophils. Treatment with rhCSF3 increased the proliferation of human melanocytes, but not their tyrosinase activity. Transcripts of CSF3R in human melanocytes, M14, A375 melanoma and A431 squamous cell carcinoma cells were also detected. Expression of the CSF3R V3 transcript was lower in melanocytes than in M14, A375 melanoma and A431 squamous cell carcinoma cells. In conclusion, rhCSF3 can promote melanocyte proliferation through CSF3R without affecting tyrosinase activity.

  6. Luminal Ca2+ dynamics during IP3R mediated signals

    NASA Astrophysics Data System (ADS)

    Lopez, Lucia F.; Ponce Dawson, Silvina

    2016-06-01

    The role of cytosolic Ca2+ on the kinetics of Inositol 1,4,5-triphosphate receptors (IP3Rs) and on the dynamics of IP3R-mediated Ca2+ signals has been studied at large both experimentally and by modeling. The role of luminal Ca2+ has not been investigated with that much detail although it has been found that it is relevant for signal termination in the case of Ca2+ release through ryanodine receptors. In this work we present the results of observing the dynamics of luminal and cytosolic Ca2+ simultaneously in Xenopus laevis oocytes. Combining observations and modeling we conclude that there is a rapid mechanism that guarantees the availability of free Ca2+ in the lumen even when a relatively large Ca2+ release is evoked. Comparing the dynamics of cytosolic and luminal Ca2+ during a release, we estimate that they are consistent with a 80% of luminal Ca2+ being buffered. The rapid availability of free luminal Ca2+ correlates with the observation that the lumen occupies a considerable volume in several regions across the images.

  7. High Affinity Dopamine D3 Receptor (D3R)-Selective Antagonists Attenuate Heroin Self-Administration in Wild-Type but not D3R Knockout Mice

    PubMed Central

    2015-01-01

    The dopamine D3 receptor (D3R) is a promising target for the development of pharmacotherapeutics to treat substance use disorders. Several D3R-selective antagonists are effective in animal models of drug abuse, especially in models of relapse. Nevertheless, poor bioavailability, metabolic instability, and/or predicted toxicity have impeded success in translating these drug candidates to clinical use. Herein, we report a series of D3R-selective 4-phenylpiperazines with improved metabolic stability. A subset of these compounds was evaluated for D3R functional efficacy and off-target binding at selected 5-HT receptor subtypes, where significant overlap in SAR with D3R has been observed. Several high affinity D3R antagonists, including compounds 16 (Ki = 0.12 nM) and 32 (Ki = 0.35 nM), showed improved metabolic stability compared to the parent compound, PG648 (6). Notably, 16 and the classic D3R antagonist SB277011A (2) were effective in reducing self-administration of heroin in wild-type but not D3R knockout mice. PMID:26203768

  8. The CE3R Network: current status and future perspectives

    NASA Astrophysics Data System (ADS)

    Lenhardt, Wolfgang; Pesaresi, Damiano; Živčić, Mladen; Costa, Giovanni; Kuk, Kresimir; Bondár, István; Duni, Llambro; Spacek, Petr

    2016-04-01

    In order to improve the monitoring of seismic activities in the border regions and to enhance the collaboration between countries and seismological institutions in Central Europe, the Environment Agency of the Slovenian Republic (ARSO), the Italian National Institute for Oceanography and Experimental Geophysics (OGS), the University of Trieste (UniTS) and the Austrian Central Institute for Meteorology and Geodynamics (ZAMG) established in 2001 the "South Eastern Alps Transfrontier Seismological Network". In May 2014 ARSO, OGS, UniTS and ZAMG agreed to formalize the transfrontier network, to name it "Central and East European Earthquake Research Network", (CE3RN or CE3R Network) in order to locate it geographically since cross-border networks can be established in other areas of the world and to expand their cooperation, including institutions in other countries. The University of Zagreb (UniZG) joined CE3RN in October 2014. The Kövesligethy Radó Seismological Observatory (KRSZO) of the Hungarian Academy of Sciences joined CE3RN in October 2015. The Institute of Geosciences, Energy, Water and Environment (IGEWE) of the Polytechnic University of Tirana joined CE3RN in November 2015. The Institute of Physics of the Earth (IPE) of the Masaryk University in Brno joined CE3RN in November 2015. CE3RN Parties intend to formalize and possibly extend their ongoing cooperation in the field of seismological data acquisition, exchange and use for seismological and earthquake engineering and civil protection purposes. The purpose of this cooperation is to retain and expand the existing cross-border network, specify the rules of conduct in the network management, improvements, extensions and enlargements, enhance seismological research in the region, and support civil protection activities. Since the formal establishment of CE3RN, several common projects have been completed, like the SeismoSAT project for the seismic data center connection over satellite funded by the Interreg

  9. Bulk superconductivity in bismuth oxysulfide Bi4O4S3.

    PubMed

    Singh, Shiva Kumar; Kumar, Anuj; Gahtori, Bhasker; Shruti; Sharma, Gyaneshwar; Patnaik, Satyabrata; Awana, Veer P S

    2012-10-10

    A very recent report on the observation of superconductivity in Bi(4)O(4)S(3) [Mizuguchi, Y.; http://arxiv.org/abs/1207.3145] could potentially reignite the search for superconductivity in a broad range of layered sulfides. We report here the synthesis of Bi(4)O(4)S(3) at 500 °C by a vacuum encapsulation technique and its basic characterizations. The as-synthesized Bi(4)O(4)S(3) was contaminated with small amounts of Bi(2)S(3) and Bi impurities. The majority phase was found to be tetragonal (space group I4/mmm) with lattice parameters a = 3.9697(2) Å and c = 41.3520(1) Å. Both AC and DC magnetization measurements confirmed that Bi(4)O(4)S(3) is a bulk superconductor with a superconducting transition temperature (T(c)) of 4.4 K. Isothermal magnetization (M-H) measurements indicated closed loops with clear signatures of flux pinning and irreversible behavior. The lower critical field (H(c1)) at 2 K for the new superconductor was found to be ~15 Oe. Magnetotransport measurements showed a broadening of the resistivity (ρ) and a decrease in T(c) (ρ = 0) with increasing magnetic field. The extrapolated upper critical field H(c2)(0) was ~31 kOe with a corresponding Ginzburg-Landau coherence length of ~100 Å . In the normal state, the ρ ~ T(2) dependence was not indicated. Hall resistivity data showed a nonlinear magnetic field dependence. Our magnetization and electrical transport measurements substantiate the appearance of bulk superconductivity in as-synthesized Bi(4)O(4)S(3). On the other hand, Bi heat-treated at the same temperature is not superconducting, thus excluding the possibility of impurity-driven superconductivity in the newly discovered superconductor Bi(4)O(4)S(3).

  10. Removal of H2S from gas stream using combined plasma photolysis technique at atmospheric pressure.

    PubMed

    Huang, Li; Xia, Lanyan; Ge, Xiaoxue; Jing, Hengye; Dong, Wenbo; Hou, Huiqi

    2012-06-01

    In this paper, H(2)S in gas stream was successfully decomposed at atmospheric pressure by dielectric barrier discharge plasma and VUV-UV radiation from a combined plasma photolysis reactor (CDBD). In comparison with DBD, CDBD enhanced H(2)S removal efficiency significantly at the same applied voltage, inlet H(2)S concentration and gas residence time. H(2)S removal efficiency was determined as a function of Kr pressure, applied voltage, inlet H(2)S concentration, and gas residence time. H(2)S removal efficiency could reach as high as 93% at inlet H(2)S concentration of 27.1 mg m(-3), residence time of 0.4 s, and applied voltage of 7.5 kV. The main products were discerned as H(2)O and SO(4)(2-) based on FTIR and IC analysis.

  11. Search for direct photons in Υ(4S) decays

    NASA Astrophysics Data System (ADS)

    Narain, M.; Heintz, U.; Lee-Franzini, J.; Lovelock, D. M. J.; Schamberger, R. D.; Willins, J.; Yanagisawa, C.; Franzini, P.; Tuts, P. M.

    1990-11-01

    We have searched for photon signals in Υ(4S) decays, indicative of large decay rates involving annihilation of the bb¯ pair rather than decays to BB¯ meson pairs. We do not observe any evidence for such signals. We also obtain a model-independent upper limit of (4.5-6.0)% for the branching ratio of Υ(4S)-->ggX, for 0

  12. SLC9A3R1 stimulates autophagy via BECN1 stabilization in breast cancer cells.

    PubMed

    Liu, Hong; Ma, Yan; He, Hong-Wei; Wang, Jia-Ping; Jiang, Jian-Dong; Shao, Rong-Guang

    2015-01-01

    Autophagy, a self-catabolic process, has been found to be involved in abrogating the proliferation and metastasis of breast cancer. SLC9A3R1 (solute carrier family 9, subfamily A [NHE3, cation proton antiporter 3], member 3 regulator 1), a multifunctional scaffold protein, is involved in suppressing breast cancer cells proliferation and the SLC9A3R1-related signaling pathway regulates the activation of autophagy processes. However, the precise regulatory mechanism and signaling pathway of SLC9A3R1 in the regulation of autophagy processes in breast cancer cells remains unknown. Here, we report that the stability of BECN1, the major component of the autophagic core lipid kinase complex, is augmented in SLC9A3R1-overexpressing breast cancer MDA-MB-231 cells, subsequently stimulating autophagy by attenuating the interaction between BECN1 and BCL2. Initially, we found that SLC9A3R1 partially stimulated autophagy through the PTEN-PI3K-AKT1 signaling cascade in MDA-MB-231 cells. SLC9A3R1 then attenuated the interaction between BECN1 and BCL2 to stimulate the autophagic core lipid kinase complex. Further findings revealed that SLC9A3R1 bound to BECN1 and subsequently blocked ubiquitin-dependent BECN1 degradation. And the deletion of the C-terminal domain of SLC9A3R1 resulted in significantly reduced binding to BECN1. Moreover, the lack of C-terminal of SLC9A3R1 neither reduced the ubiquitination of BECN1 nor induced autophagy in breast cancer cells. The decrease in BECN1 degradation induced by SLC9A3R1 resulted in the activity of autophagy stimulation in breast cancer cells. These findings indicate that the SLC9A3R1-BECN1 signaling pathway participates in the activation of autophagy processes in breast cancer cells.

  13. Isotope shift and hyperfine splitting of the 4s{yields}5p transition in potassium

    SciTech Connect

    Behrle, Alexandra; Koschorreck, Marco; Koehl, Michael

    2011-05-15

    We have investigated the 4s {sup 2}S{sub 1/2}{yields}5p {sup 2}P{sub 1/2} transition (D{sub 1} line) of the potassium isotopes {sup 39}K, {sup 40}K, and {sup 41}K using Doppler-free laser saturation spectroscopy. Our measurements reveal the hyperfine splitting of the 5p {sup 2}P{sub 1/2} state of {sup 40}K, and we have determined the specific mass shift and the nuclear field shift constants for the blue (405 nm) D{sub 1} line.

  14. Porous SnIn4S8 microspheres in a new polymorph that promotes dyes degradation under visible light irradiation.

    PubMed

    Yan, Tingjiang; Li, Liping; Li, Guangshe; Wang, Yunjian; Hu, Wanbiao; Guan, Xiangfeng

    2011-02-15

    Porous SnIn(4)S(8) microspheres were initially synthesized through a facile solvothermal approach and were investigated as visible-light driven photocatalysts for dyes degradation in polluted water. The photocatalysts were characterized by XRD, SEM, TEM, N(2) adsorption-desorption, and UV-vis diffuse reflectance techniques. Results demonstrated that the as-synthesized SnIn(4)S(8) was of a new tetragonal polymorph, showing a band-gap of 2.5 eV, a specific surface area of 197 m(2) g(-1), and an accessible porous structure as well. The photocatalytic activity of the porous SnIn(4)S(8) was evaluated by decomposition of several typical organic dyes including methyl orange, rhodamine B, and methylene blue in aqueous solution under visible light irradiation. It is demonstrated that porous SnIn(4)S(8) was highly photoactive and stable for dyes degradation, showing photocatalytic activity much higher than binary constituent sulfides like In(2)S(3), SnS(2), or even ternary chalcogenide ZnIn(2)S(4) photocatalyst. The excellent photocatalytic performance of porous SnIn(4)S(8) is the consequence of its high surface area, well-defined porous texture, and large amount of hydroxyl radicals.

  15. Enhanced Electrochemical Performances of Bi2O3/rGO Nanocomposite via Chemical Bonding as Anode Materials for Lithium Ion Batteries.

    PubMed

    Deng, Zhuo; Liu, Tingting; Chen, Tao; Jiang, Jiaxiang; Yang, Wanli; Guo, Jun; Zhao, Jianqing; Wang, Haibo; Gao, Lijun

    2017-03-31

    Bismuth oxide/reduced graphene oxide (termed Bi2O3@rGO) nanocomposite has been facilely prepared by a solvothermal method via introducing chemical bonding that has been demonstrated by Raman and X-ray photoelectron spectroscopy spectra. Tremendous single-crystal Bi2O3 nanoparticles with an average size of ∼5 nm are anchored and uniformly dispersed on rGO sheets. Such a nanostructure results in enhanced electrochemical reversibility and cycling stability of Bi2O3@rGO composite materials as anodes for lithium ion batteries in comparison with agglomerated bare Bi2O3 nanoparticles. The Bi2O3@rGO anode material can deliver a high initial capacity of ∼900 mAh/g at 0.1C and shows excellent rate capability of ∼270 mAh/g at 10C rates (1C = 600 mA/g). After 100 electrochemical cycles at 1C, the Bi2O3@rGO anode material retains a capacity of 347.3 mAh/g with corresponding capacity retention of 79%, which is significantly better than that of bare Bi2O3 material. The lithium ion diffusion coefficient during lithiation-delithiation of Bi2O3@rGO nanocomposite has been evaluated to be around ∼10(-15)-10(-16) cm(2)/S. This work demonstrates the effects of chemical bonding between Bi2O3 nanoparticles and rGO substrate on enhanced electrochemical performances of Bi2O3@rGO nanocomposite, which can be used as a promising anode alterative for superior lithium ion batteries.

  16. Controlling H{sub 2}S emissions

    SciTech Connect

    Nagl, G.J.

    1997-03-01

    With its signature rotten egg smell, hydrogen sulfide (H{sub 2}S) is not only odorous, but corrosive and toxic, too. It is produced naturally, by the anaerobic decomposition of sulfur-bearing materials, and synthetically, by a host of chemical process operations, including hydrogenation and hydrodesulfurization and coking. Many processes have been developed to convert H{sub 2}S to innocuous forms, such as elemental sulfur and sulfates. Selecting the best one depends on the overall composition and variability of the gas stream, the concentration of H{sub 2}S present, and the absolute quantity of H{sub 2}S to be removed. This article describes the advantages and disadvantages of seven H{sub 2}S removal systems. Described are: the Claus process, chemical oxidants, caustic scrubbers, adsorption, H{sub 2}S scavengers, amine absorption units, and liquid-phase oxidation systems.

  17. Compositional Analysis of Asymmetric and Symmetric Dimethylated H3R2 Using Liquid Chromatography-Tandem Mass Spectrometry-Based Targeted Proteomics.

    PubMed

    Xu, Qingqing; Xu, Feifei; Liu, Liang; Chen, Yun

    2016-09-06

    Protein arginine methylation is one of the common post-translational modifications in cellular processes. To date, two isomeric forms of dimethylated arginine have been identified: asymmetric N(G),N(G)-dimethylarginine (aDMA), and symmetric N(G),N'(G)-dimethylarginine (sDMA). Evidence indicated that these isomers can coexist and have different or even opposite functions, with aDMA and sDMA forms of arginine 2 on histone H3 (i.e., H3R2me2a and H3R2me2s) being an example. Thus, specific detection and quantification of each isomeric form is important. Current methods are capable of predicting and detecting thousands of methylarginine sites in proteins, whereas differentiation and stoichiometric measurement of dimethylated protein isomers are still challenging. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)-based targeted proteomics has emerged as a promising technique for site-specific quantification of protein methylation using enzymatic peptides as surrogates of target proteins. However, it should be pointed out that a routine targeted proteomics strategy cannot easily distinguish sDMA- and aDMA-containing surrogate peptides due to their common nature. The estimated amount should be considered as the sum of both arginine dimethylated isomers. In this study, compositional analysis based on a linear algebra algorithm as an add-on to targeted proteomics was employed to quantify H3R2me2a and H3R2me2s (i.e., surrogate peptides of AR(me2a)TK(me1/2)QT and AR(me2s)TK(me1/2)QT). To achieve this simultaneous quantification, a targeted proteomics assay was developed and validated for each isomer first. With the slope and intercept of their calibration curves for each multiple reaction monitoring (MRM) transition, linear algebraic equations were derived. Using a series of mock mixtures consisting of isomers in varying concentrations, the reliability of the method was confirmed. Finally, the H3R2 dimethylation status was analyzed in normal MCF-10A cells

  18. Superconductivity in semimetallic Bi3O2S3

    DOE PAGES

    Li, L.; Parker, D.; Babkevich, P.; ...

    2015-03-12

    We report in this paper a further investigation on the thermodynamic and transport properties, and an assessment of theoretical calculations, for the BiS2-layered Bi3O2S3 superconductor. The polycrystalline sample is synthesized with a superconducting transition temperature of Tconset=5.75K and Tczero=4.03K (≈Tcmag) that drops to 3.3 K by applying a hydrostatic pressure of 6 kbar. Density-of-states (DOS) calculations give substantial hybridization between Bi, O, and S, with Bi the largest component of DOS, which supports the idea that the BiS2 layer is relevant for producing electron-phonon coupling. An analysis of previously published specific heat data for Bi3O2S3 is additionally suggestive of amore » strong electron-phonon interaction in the Bi-O-S system. The analysis of the Seebeck coefficient results strongly suggests that Bi3O2S3 is a semimetal. In fact, we found the semimetallic or narrow band gap behavior may occur in certain other materials in the BiS2-layered class of materials, such as Bi4O4S3.« less

  19. CYP2S1: A short review

    SciTech Connect

    Saarikoski, Sirkku T. . E-mail: sirkku.saarikoski@ktl.fi; Rivera, Steven P.; Hankinson, Oliver; Husgafvel-Pursiainen, Kirsti

    2005-09-01

    A new member of the cytochrome P450 superfamily, CYP2S1, has recently been identified in human and mouse. In this paper, we review the data currently available for CYP2S1. The human CYP2S1 gene is located in chromosome 19q13.2 within a cluster including CYP2 family members CYP2A6, CYP2A13, CYP2B6, and CYP2F1. These genes also show the highest homology to the human CYP2S1. The gene has recently been found to harbor genetic polymorphism. CYP2S1 is inducible by dioxin, the induction being mediated by the Aryl Hydrocarbon Receptor (AHR) and Aryl Hydrocarbon Nuclear Translocator (ARNT) in a manner typical for CYP1 family members. In line with this, CYP2S1 has been shown to be inducible by coal tar, an abundant source of PAHs, and it was recently reported to metabolize naphthalene. This points to the involvement of CYP2S1 in the metabolism of toxic and carcinogenic compounds, similar to other dioxin-inducible CYPs. CYP2S1 is expressed in epithelial cells of a wide variety of extrahepatic tissues. The highest expression levels have been observed in the epithelial tissues frequently exposed to xenobiotics, e.g., the respiratory, gastrointestinal, and urinary tracts, and in the skin. The observed ubiquitous tissue distribution, as well as the expression of CYP2S1 throughout embryogenesis suggest that CYP2S1 is likely to metabolize important endogenous substrates; thus far, retinoic acid has been identified. In conclusion, CYP2S1 exhibits many features of interest for human health and thus warrants further investigation.

  20. First observation of the decay B0→ψ (2 S )π0

    NASA Astrophysics Data System (ADS)

    Chobanova, V.; Dalseno, J.; Kiesling, C.; Abdesselam, A.; Adachi, I.; Aihara, H.; Asner, D. M.; Aushev, T.; Ayad, R.; Babu, V.; Badhrees, I.; Bahinipati, S.; Bakich, A. M.; Barberio, E.; Behera, P.; Bhardwaj, V.; Bhuyan, B.; Biswal, J.; Bobrov, A.; Bozek, A.; Bračko, M.; Browder, T. E.; Červenkov, D.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chistov, R.; Cho, K.; Choi, Y.; Cinabro, D.; Dash, N.; Doležal, Z.; Drásal, Z.; Drutskoy, A.; Eidelman, S.; Farhat, H.; Fast, J. E.; Ferber, T.; Fulsom, B. G.; Gaur, V.; Gabyshev, N.; Garmash, A.; Gillard, R.; Goh, Y. M.; Goldenzweig, P.; Golob, B.; Grzymkowska, O.; Haba, J.; Hara, T.; Hayasaka, K.; Hayashii, H.; Hou, W.-S.; Iijima, T.; Inami, K.; Ishikawa, A.; Iwasaki, Y.; Jaegle, I.; Jeon, H. B.; Joffe, D.; Joo, K. K.; Julius, T.; Kato, E.; Katrenko, P.; Kawasaki, T.; Kim, D. Y.; Kim, H. J.; Kim, J. B.; Kim, K. T.; Kim, M. J.; Kim, S. H.; Kim, Y. J.; Kinoshita, K.; Kodyš, P.; Korpar, S.; Križan, P.; Krokovny, P.; Kuhr, T.; Kumar, R.; Kumita, T.; Kuzmin, A.; Kwon, Y.-J.; Lee, I. S.; Li, H.; Li, L.; Li, Y.; Li Gioi, L.; Libby, J.; Liventsev, D.; Masuda, M.; Matvienko, D.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Mohanty, G. B.; Mohanty, S.; Moll, A.; Moon, H. K.; Mori, T.; Mussa, R.; Nakano, E.; Nakao, M.; Nanut, T.; Natkaniec, Z.; Nayak, M.; Nedelkovska, E.; Nisar, N. K.; Nishida, S.; Ogawa, S.; Pakhlov, P.; Pakhlova, G.; Pal, B.; Park, C. W.; Park, H.; Paul, S.; Pedlar, T. K.; Pestotnik, R.; Petrič, M.; Piilonen, L. E.; Pulvermacher, C.; Rauch, J.; Ribežl, E.; Ritter, M.; Ryu, S.; Sahoo, H.; Sakai, Y.; Sandilya, S.; Sanuki, T.; Savinov, V.; Schlüter, T.; Schneider, O.; Schnell, G.; Schwanda, C.; Schwartz, A. J.; Seino, Y.; Senyo, K.; Seon, O.; Sevior, M. E.; Shebalin, V.; Shibata, T.-A.; Shiu, J.-G.; Shwartz, B.; Simon, F.; Singh, J. B.; Sohn, Y.-S.; Sokolov, A.; Solovieva, E.; Starič, M.; Stypula, J.; Sumihama, M.; Sumisawa, K.; Sumiyoshi, T.; Tamponi, U.; Teramoto, Y.; Trabelsi, K.; Uchida, M.; Uehara, S.; Uglov, T.; Unno, Y.; Uno, S.; Urquijo, P.; Usov, Y.; Van Hulse, C.; Vanhoefer, P.; Varner, G.; Vinokurova, A.; Vorobyev, V.; Wagner, M. N.; Wang, C. H.; Wang, M.-Z.; Wang, P.; Wang, X. L.; Watanabe, M.; Watanabe, Y.; Williams, K. M.; Won, E.; Yamaoka, J.; Yashchenko, S.; Ye, H.; Yelton, J.; Yuan, C. Z.; Yusa, Y.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.; Belle Collaboration

    2016-02-01

    We report a measurement of the B0→ψ (2 S )π0 branching fraction based on the full ϒ (4 S ) data set of 772 ×106 B B ¯ pairs collected by the Belle detector at the KEKB asymmetric-energy e+e- collider. We obtain B (B0→ψ (2 S )π0 )=(1.17 ±0.17 (stat ) ±0.08 (syst ) )×10-5 . The result has a significance of 7.2 standard deviations and is the first observation of the decay B0→ψ (2 S )π0.

  1. Enhanced electrochemical oxidation of Acid Red 3R wastewater with iron phosphomolybdate supported catalyst.

    PubMed

    Wang, Li; Yue, Lin; Shi, Feng; Guo, Jianbo; Yang, Jingliang; Lian, Jing; Luo, Xiao; Guo, Yankai

    2015-01-01

    Electrochemical oxidation of Acid Red 3R (AR3R) was investigated with the new catalyst of iron phosphomolybdate (FePMo12) supported on modified molecular sieves type 4 Å (4A) as packing materials in the reactor. The results of the Fourier transform infrared spectroscopy and X-ray diffraction indicated that the heteropolyanion had a Keggin structure. The optimal conditions for decolorization of simulated AR3R wastewater were as follows: current density 35 mA/cm², initial pH 4.0, airflow 0.08 m³/hour and inter-electrode distance 3.0 cm. With the addition of NaCl to the system, the decolorization efficiency increased. But Na₂SO₄had a negative effect on the decolorization efficiency, which was attributed to the negative salt effect. The degradation mechanisms of AR3R were also discussed in detail.

  2. Hanford environmental analytical methods (methods as of March 1990). Appendix A3-R

    SciTech Connect

    Goheen, S.C.; McCulloch, M.; Daniel, J.L.

    1993-05-01

    Techniques in use at the Hanford Reservation as of March, 1990 for the analysis of liquids and radioactive effluents are described. Limitations and applications of the techniques are included. This report is Appendix A3-R.

  3. Detection and quantification of 2H and 3R phases in commercial graphene-based materials

    PubMed Central

    Seehra, Mohindar S.; Geddam, Usha K.; Schwegler-Berry, Diane; Stefaniak, Aleksandr B.

    2017-01-01

    Graphene-based material (GBM) samples acquired from commercial sources are investigated using X-ray diffraction (XRD). Of the 18 GBM samples investigated here, seven samples show XRD patterns with features characteristic of the graphite structure. The XRD patterns of the seven samples are analyzed showing the presence of both the ABA (2H) structure and the ABCA (3R) structure. After de-convoluting the (101) lines of the 2H and 3R structures, the areas under the peaks are used to determine the relative concentrations of the 2H and 3R phases present, typically yielding the ratio 60/40 for 2H/3R. The presence of the 3R structure is important since the 3R structure is a semiconductor with tunable band gap and it is less stable than the 2H structure. The number of layers determined from the analysis of the XRD data varies between 65 and 109 for different samples yielding thickness of the graphite sheets varying between 22 nm and 37 nm. Scanning electron microscopy and transmission electron microscopy of three representative samples confirms the sheet-like morphology and stacking of the graphene layers in the samples. Relevance of these results in connection with their potential applications and toxicology is briefly discussed.

  4. A potent antibrowning agent from pine needles of Cedrus deodara: 2R,3R-dihydromyricetin.

    PubMed

    Liang, Xue; Wu, Yan-Ping; Qiu, Jing-Hong; Zhong, Kai; Gao, Hong

    2014-09-01

    This article focuses on finding the novel antibrowning agents from the pine needles of Cedrus deodara and studying its antibrowning effect. By bioassay guide of tyrosinase inhibitory activity, the main active compound was isolated and purified from 50% methanol extract of pine needles of C. deodara through macroporous resin Diaion HP-20 column chromatography and high-performance liquid chromatography. Based on mass and nuclear magnetic resonance data, the active compound was identified as 2R,3R-dihydromyricetin, which showed the potent monophenolase and diphenolase inhibitory activities. Moreover, 2R,3R-dihydromyricetin exhibited a strong ABTS radical scavenging activity with a dose-dependent manner. The antibrowning efficacy of 2R,3R-dihydromyricetin was evaluated by monitoring the changes of L*, a*, and b* values and total color difference (△E) on fresh-cut apple slices. It was found that 2R,3R-dihydromyricetin was effective in inhibiting the browning of apple slices treated with a concentration as low as 0.05% at 25 °C for 24 h. Its antibrowning effect was significantly better than ascorbic acid (0.5%) alone. Furthermore, 2R,3R-dihydromyricetin showed a good synergistic antibrowning effect with ascorbic acid. This is the first report that 2R,3R-dihydromyricetin from pine needles of C. deodara may be used as a potential antibrowning agent in protecting against food browning.

  5. ERP44 inhibits human lung cancer cell migration mainly via IP3R2.

    PubMed

    Huang, Xue; Jin, Meng; Chen, Ying-Xiao; Wang, Jun; Zhai, Kui; Chang, Yan; Yuan, Qi; Yao, Kai-Tai; Ji, Guangju

    2016-06-01

    Cancer cell migration is involved in tumour metastasis. However, the relationship between calcium signalling and cancer migration is not well elucidated. In this study, we used the human lung adenocarcinoma A549 cell line to examine the role of endoplasmic reticulum protein 44 (ERP44), which has been reported to regulate calcium release inside of the endoplasmic reticulum (ER), in cell migration. We found that the inositol 1,4,5-trisphosphate receptors (IP3Rs/ITPRs) inhibitor 2-APB significantly inhibited A549 cell migration by inhibiting cell polarization and pseudopodium protrusion, which suggests that Ca2+ is necessary for A549 cell migration. Similarly, the overexpression of ERP44 reduced intracellular Ca2+ release via IP3Rs, altered cell morphology and significantly inhibited the migration of A549 cells. These phenomena were primarily dependent on IP3R2 because wound healing in A549 cells with IP3R2 rather than IP3R1 or IP3R3 siRNA was markedly inhibited. Moreover, the overexpression of ERP44 did not affect the migration of the human neuroblastoma cell line SH-SY5Y, which mainly expresses IP3R1. Based on the above observations, we conclude that ERP44 regulates A549 cell migration mainly via an IP3R2-dependent pathway.

  6. ERP44 inhibits human lung cancer cell migration mainly via IP3R2

    PubMed Central

    Zhai, Kui; Chang, Yan; Yuan, Qi; Yao, Kai-Tai; Ji, Guangju

    2016-01-01

    Cancer cell migration is involved in tumour metastasis. However, the relationship between calcium signalling and cancer migration is not well elucidated. In this study, we used the human lung adenocarcinoma A549 cell line to examine the role of endoplasmic reticulum protein 44 (ERP44), which has been reported to regulate calcium release inside of the endoplasmic reticulum (ER), in cell migration. We found that the inositol 1,4,5-trisphosphate receptors (IP3Rs/ITPRs) inhibitor 2-APB significantly inhibited A549 cell migration by inhibiting cell polarization and pseudopodium protrusion, which suggests that Ca2+ is necessary for A549 cell migration. Similarly, the overexpression of ERP44 reduced intracellular Ca2+ release via IP3Rs, altered cell morphology and significantly inhibited the migration of A549 cells. These phenomena were primarily dependent on IP3R2 because wound healing in A549 cells with IP3R2 rather than IP3R1 or IP3R3 siRNA was markedly inhibited. Moreover, the overexpression of ERP44 did not affect the migration of the human neuroblastoma cell line SH-SY5Y, which mainly expresses IP3R1. Based on the above observations, we conclude that ERP44 regulates A549 cell migration mainly via an IP3R2-dependent pathway. PMID:27347718

  7. Identification of (2S,3S)-β-Methyltryptophan as the Real Biosynthetic Intermediate of Antitumor Agent Streptonigrin

    PubMed Central

    Kong, Dekun; Zou, Yi; Zhang, Zhang; Xu, Fei; Brock, Nelson L.; Zhang, Liping; Deng, Zixin; Lin, Shuangjun

    2016-01-01

    Streptonigrin is a potent antitumor antibiotic, active against a wide range of mammalian tumor cells. It was reported that its biosynthesis relies on (2S,3R)-β-methyltryptophan as an intermediate. In this study, the biosynthesis of (2S,3R)-β-methyltryptophan and its isomer (2S,3S)-β-methyltryptophan by enzymes from the streptonigrin biosynthetic pathway is demonstrated. StnR is a pyridoxal 5′-phosphate (PLP)-dependent aminotransferase that catalyzes a transamination between L-tryptophan and β-methyl indolepyruvate. StnQ1 is an S-adenosylmethionine (SAM)-dependent C-methyltransferase and catalyzes β-methylation of indolepyruvate to generate (R)-β-methyl indolepyruvate. Although StnR exhibited a significant preference for (S)-β-methyl indolepyruvate over the (R)-epimer, StnQ1 and StnR together catalyze (2S,3R)-β-methyltryptophan formation from L-tryptophan. StnK3 is a cupin superfamily protein responsible for conversion of (R)-β-methyl indolepyruvate to its (S)-epimer and enables (2S,3S)-β-methyltryptophan biosynthesis from L-tryptophan when combined with StnQ1 and StnR. Most importantly, (2S,3S)-β-methyltryptophan was established as the biosynthetic intermediate of the streptonigrin pathway by feeding experiments with a knockout mutant, contradicting the previous proposal that stated (2S,3R)-β-methyltryptophan as the intermediate. These data set the stage for the complete elucidation of the streptonigrin biosynthetic pathway, which would unlock the potential of creating new streptonigrin analogues by genetic manipulation of the biosynthetic machinery. PMID:26847951

  8. Microvillous cells expressing IP3R3 in the olfactory epithelium of mice

    PubMed Central

    Hegg, Colleen C.; Jia, Cuihong; Chick, Wallace S.; Restrepo, Diego; Hansen, Anne

    2015-01-01

    Microvillous cells of the main olfactory epithelium have been described variously as primary olfactory neurons, secondary chemosensory cells, or non-sensory cells. Here we generated an IP3R3tm1(tauGFP) mouse in which the coding region for a fusion protein of tau and green fluorescent protein (tauGFP) replaces the first exon of the Itpr3 gene. We provide immunohistochemical and functional characterization of the cells expressing IP3 receptor type 3 in the olfactory epithelium. Since we determined that these cells bear microvilli at their apex, we call these cells IP3R3 MV cells. The cell body of these IP3R3 MV cells lies in the upper third of the main olfactory epithelium; a long thick basal process projects towards the base of the epithelium without penetrating the basal lamina. Retrograde labeling and unilateral bulbectomy corroborated that these IP3R3 MV cells do not extend axons to the olfactory bulb and therefore are not olfactory sensory neurons. The immunohistochemical features of the IP3R3 MV cell varied suggesting either developmental stages or the existence of subsets of these cells. Thus, for example, subsets of the IP3R3 MV cells make contact with substance P fibers or express the purinergic receptor P2X3. In addition, in recordings of intracellular calcium, these cells respond to ATP and substance P as well as to a variety of odors. The characterization of IP3R3 MV cells as non-neuronal chemoresponsive cells helps explain the differing descriptions of microvillous cells in the literature. PMID:20958798

  9. Atrial fibrillation detection using an iPhone 4S.

    PubMed

    Lee, Jinseok; Reyes, Bersain A; McManus, David D; Maitas, Oscar; Mathias, Oscar; Chon, Ki H

    2013-01-01

    Atrial fibrillation (AF) affects three to five million Americans and is associated with significant morbidity and mortality. Existing methods to diagnose this paroxysmal arrhythmia are cumbersome and/or expensive. We hypothesized that an iPhone 4S can be used to detect AF based on its ability to record a pulsatile photoplethysmogram signal from a fingertip using the built-in camera lens. To investigate the capability of the iPhone 4S for AF detection, we first used two databases, the MIT-BIH AF and normal sinus rhythm (NSR) to derive discriminatory threshold values between two rhythms. Both databases include RR time series originating from 250 Hz sampled ECG recordings. We rescaled the RR time series to 30 Hz so that the RR time series resolution is 1/30 (s) which is equivalent to the resolution from an iPhone 4S. We investigated three statistical methods consisting of the root mean square of successive differences (RMSSD), the Shannon entropy (ShE) and the sample entropy (SampE), which have been proved to be useful tools for AF assessment. Using 64-beat segments from the MIT-BIH databases, we found the beat-to-beat accuracy value of 0.9405, 0.9300, and 0.9614 for RMSSD, ShE, and SampE, respectively. Using an iPhone 4S, we collected 2-min pulsatile time series from 25 prospectively recruited subjects with AF pre- and postelectrical cardioversion. Using derived threshold values of RMSSD, ShE and SampE from the MIT-BIH databases, we found the beat-to-beat accuracy of 0.9844, 0.8494, and 0.9522, respectively. It should be recognized that for clinical applications, the most relevant objective is to detect the presence of AF in the data. Using this criterion, we achieved an accuracy of 100% for both the MIT-BIH AF and iPhone 4S databases.

  10. Abolished InsP3R2 function inhibits sweat secretion in both humans and mice.

    PubMed

    Klar, Joakim; Hisatsune, Chihiro; Baig, Shahid M; Tariq, Muhammad; Johansson, Anna C V; Rasool, Mahmood; Malik, Naveed Altaf; Ameur, Adam; Sugiura, Kotomi; Feuk, Lars; Mikoshiba, Katsuhiko; Dahl, Niklas

    2014-11-01

    There are 3 major sweat-producing glands present in skin; eccrine, apocrine, and apoeccrine glands. Due to the high rate of secretion, eccrine sweating is a vital regulator of body temperature in response to thermal stress in humans; therefore, an inability to sweat (anhidrosis) results in heat intolerance that may cause impaired consciousness and death. Here, we have reported 5 members of a consanguineous family with generalized, isolated anhidrosis, but morphologically normal eccrine sweat glands. Whole-genome analysis identified the presence of a homozygous missense mutation in ITPR2, which encodes the type 2 inositol 1,4,5-trisphosphate receptor (InsP3R2), that was present in all affected family members. We determined that the mutation is localized within the pore forming region of InsP3R2 and abrogates Ca2+ release from the endoplasmic reticulum, which suggests that intracellular Ca2+ release by InsP3R2 in clear cells of the sweat glands is important for eccrine sweat production. Itpr2-/- mice exhibited a marked reduction in sweat secretion, and evaluation of sweat glands from Itpr2-/- animals revealed a decrease in Ca2+ response compared with controls. Together, our data indicate that loss of InsP3R2-mediated Ca2+ release causes isolated anhidrosis in humans and suggest that specific InsP3R inhibitors have the potential to reduce sweat production in hyperhidrosis.

  11. A mouse model for a partially inactive obesity-associated human MC3R variant

    PubMed Central

    Lee, Bonggi; Koo, Jashin; Yun Jun, Joo; Gavrilova, Oksana; Lee, Yongjun; Seo, Arnold Y.; Taylor-Douglas, Dezmond C.; Adler-Wailes, Diane C.; Chen, Faye; Gardner, Ryan; Koutzoumis, Dimitri; Sherafat Kazemzadeh, Roya; Roberson, Robin B.; Yanovski, Jack A.

    2016-01-01

    We previously reported children homozygous for two MC3R sequence variants (C17A+G241A) have greater fat mass than controls. Here we show, using homozygous knock-in mouse models in which we replace murine Mc3r with wild-type human (MC3RhWT/hWT) and double-mutant (C17A+G241A) human (MC3RhDM/hDM) MC3R, that MC3RhDM/hDM have greater weight and fat mass, increased energy intake and feeding efficiency, but reduced length and fat-free mass compared with MC3RhWT/hWT. MC3RhDM/hDM mice do not have increased adipose tissue inflammatory cell infiltration or greater expression of inflammatory markers despite their greater fat mass. Serum adiponectin levels are increased in MC3RhDM/hDM mice and MC3RhDM/hDM human subjects. MC3RhDM/hDM bone- and adipose tissue-derived mesenchymal stem cells (MSCs) differentiate into adipocytes that accumulate more triglyceride than MC3RhWT/hWT MSCs. MC3RhDM/hDM impacts nutrient partitioning to generate increased adipose tissue that appears metabolically healthy. These data confirm the importance of MC3R signalling in human metabolism and suggest a previously-unrecognized role for the MC3R in adipose tissue development. PMID:26818770

  12. Transcriptional repression by MYB3R proteins regulates plant organ growth

    PubMed Central

    Kobayashi, Kosuke; Suzuki, Toshiya; Iwata, Eriko; Nakamichi, Norihito; Suzuki, Takamasa; Chen, Poyu; Ohtani, Misato; Ishida, Takashi; Hosoya, Hanako; Müller, Sabine; Leviczky, Tünde; Pettkó-Szandtner, Aladár; Darula, Zsuzsanna; Iwamoto, Akitoshi; Nomoto, Mika; Tada, Yasuomi; Higashiyama, Tetsuya; Demura, Taku; Doonan, John H; Hauser, Marie-Theres; Sugimoto, Keiko; Umeda, Masaaki; Magyar, Zoltán; Bögre, László; Ito, Masaki

    2015-01-01

    In multicellular organisms, temporal and spatial regulation of cell proliferation is central for generating organs with defined sizes and morphologies. For establishing and maintaining the post-mitotic quiescent state during cell differentiation, it is important to repress genes with mitotic functions. We found that three of the Arabidopsis MYB3R transcription factors synergistically maintain G2/M-specific genes repressed in post-mitotic cells and restrict the time window of mitotic gene expression in proliferating cells. The combined mutants of the three repressor-type MYB3R genes displayed long roots, enlarged leaves, embryos, and seeds. Genome-wide chromatin immunoprecipitation revealed that MYB3R3 binds to the promoters of G2/M-specific genes and to E2F target genes. MYB3R3 associates with the repressor-type E2F, E2FC, and the RETINOBLASTOMA RELATED proteins. In contrast, the activator MYB3R4 was in complex with E2FB in proliferating cells. With mass spectrometry and pairwise interaction assays, we identified some of the other conserved components of the multiprotein complexes, known as DREAM/dREAM in human and flies. In plants, these repressor complexes are important for periodic expression during cell cycle and to establish a post-mitotic quiescent state determining organ size. PMID:26069325

  13. The Sp(3, R) Sympletic Model: a comparison of exact and approximate matrix elements

    NASA Astrophysics Data System (ADS)

    McCoy, Anna; Caprio, Mark; Rowe, David

    2014-03-01

    The Sp(3, R) symplectic model has a close physical connection to both the microscopic shell model and the collective deformation and rotational degrees of freedom, and it is a natural extension of the Elliot SU(3) model from single-shell to multi-shell dynamics. The Sp(3, R) Lie algebra--which contains the angular momentum operators, the quadrupole and vibrational momentum operators and the quadrupole flow tensor operators--is the smallest algebra containing both the shell model Hamiltonian and the rotor algebra. In the limit of large number of oscillator quanta, the Sp(3, R) algebra contracts to the U(3) boson algebra. For large values of the Casimir operator of the SU(3) subalgebra, the sp(3, R) algebra further contracts to the algebra of the collective coupled rotor-vibrator model. The exact Sp(3, R) matrix elements, calculated using the vector coherent state method, are compared with approximate matrix elements calculated in the U(3) boson limit. Science Advancement under a Cottrell Scholar Award and by the US DOE under grant DE-FG02-95ER-40934.

  14. The ACTN3 R577X polymorphism is associated with muscle power in male Japanese athletes.

    PubMed

    Kikuchi, Naoki; Nakazato, Koichi; Min, Seok-ki; Ueda, Dai; Igawa, Shoji

    2014-07-01

    In this study, we investigated whether the ACTN3 R577X polymorphism is associated with muscular power in Japanese collegiate athletes by analyzing the mean and peak power results of a 30-second Wingate anaerobic test (WAnT) with respect to the ACTN3 R577X genotype in 253 Japanese athletes (144 men and 109 women). Each athlete performed a 30-second WAnT with a resistance equal to 7.5% of his or her body weight. Genotyping for the ACTN3 R577X (rs1815739) polymorphism was performed using the TaqMan approach. The ACTN3 R577X genotypes exhibited a Hardy-Weinberg equilibrium distribution in our population. The relative and absolute mean power results of the 30-second WAnT did not differ significantly among the genotypes. However, the relative peak power result of the WAnT was significantly higher in the R-allele-dominant model groups than in the XX group in male but not female athletes. These results suggest that the ACTN3 R allele is associated with the relative peak power during the WAnT in male Japanese collegiate athletes.

  15. The acetyllysine reader BRD3R promotes human nuclear reprogramming and regulates mitosis

    PubMed Central

    Shao, Zhicheng; Zhang, Ruowen; Khodadadi-Jamayran, Alireza; Chen, Bo; Crowley, Michael R.; Festok, Muhamad A.; Crossman, David K.; Townes, Tim M.; Hu, Kejin

    2016-01-01

    It is well known that both recipient cells and donor nuclei demonstrate a mitotic advantage as observed in the traditional reprogramming with somatic cell nuclear transfer (SCNT). However, it is not known whether a specific mitotic factor plays a critical role in reprogramming. Here we identify an isoform of human bromodomain-containing 3 (BRD3), BRD3R (BRD3 with Reprogramming activity), as a reprogramming factor. BRD3R positively regulates mitosis during reprogramming, upregulates a large set of mitotic genes at early stages of reprogramming, and associates with mitotic chromatin. Interestingly, a set of the mitotic genes upregulated by BRD3R constitutes a pluripotent molecular signature. The two BRD3 isoforms display differential binding to acetylated histones. Our results suggest a molecular interpretation for the mitotic advantage in reprogramming and show that mitosis may be a driving force of reprogramming. PMID:26947130

  16. Sp(3, R) decomposition of the SU(3) no-core shell model basis

    NASA Astrophysics Data System (ADS)

    Luo, Fengqiao; Caprio, Mark A.; Dytrych, Tomas

    2014-03-01

    Numerical evidence shows an important role of the symplectic Sp(3, R) symmetry in the ab initio no-core shell model results for light nuclei. Therefore, the construction of symplectic states from SU(3) states is necessary, as a prerequisite and crucial step of understanding the symplectic symmetry for those nuclei. This presentation will provide an introduction to our numerical calculation that decomposes the basis states of Sp(3, R) irreducible representations in terms of SU(3) nuclear basis. We use the null space of the Sp(3, R) generator B (02) to find the extremal states, and then ladder them with the generator A (20) to build the entire irreps. Supported by the Research Corporation for Science Advancement under a Cottrell Scholar Award, by the US DOE under grants DE-FG02-95ER-40934 and DE-SC0005248, and by the US NSF under grant OCI-0904874.

  17. ψ(2S) Production at the LHC

    NASA Astrophysics Data System (ADS)

    Du, Xiaojian; Rapp, Ralf

    2017-01-01

    We calculate the production of ψ(2S) and the pertinent double ratio of its nuclear modi cation factor (R AA) over that of the J/ψ in Pb-Pb collisions at the LHC. Based on a transport model with temperature dependent reaction rates, a sequential regeneration pattern emerges: the larger ψ(2S) width, relative to the J/ψ, around and below the critical temperature, implies that most of the ψ(2S) states are regenerated later in the evolution of the reball. This has noticeable consequences for the transverse-momentum (pT ) spectra of the regenerated charmonia. While the total yield of ψ(2S) meson remains smaller than those of J/ψ’s, their harder pT spectra can produce a double ratio above unity for a pT > 3 GeV cut, as applied by the CMS collaboration. A signi cant uncertainty in our calculations is associated with the values of the temperature where most of the ψ(2S) regeneration occurs, i.e., the quantitative temperature dependence of its inelastic width.

  18. A rietveld refinement of NaCl-type Ca 5Y 4S 11

    NASA Astrophysics Data System (ADS)

    Thompson, John G.; Withers, Ray L.; Otero-Diaz, L. Carlos

    1995-10-01

    The crystal structure of Ca 5Y 4S 11 [a = 6.942(1) Å, α = 33.380(5)°, space group R3 m, No. 166, Z = {2}/{11}, Dx = 3.042 g cm -3] was determined using Rietveld refinement of X-ray powder diffraction data collected with Cu Kα 1 radiation using a Guiner-Hägg camera. Ca 5Y 4S 11 is one end-member composition ( x = {2}/{7}) of the solid-solution (1- x)CaS. xY 2S 3, which can be considered as a modulated NaCl-type structure with modulation wave-vector q = {1}/{2}(111)∗. The sulfur sublattice is fully occupied but the metal sublattice contains {2}/{11} vacancies on average. The refinement showed that the additional observed satellite reflections were almost entirely due to metal atom/vacancy ordering rather than sulfur atom displacement. Large anisotropic thermal parameters on both the sulfur and metal atoms were consistent with disordered displacement of these atoms by 0.2-0.4 Å normal to [111]. The chemical plausibility of the refined structure and the implication of this result for other substoichiometric NaCl-type solid solutions are discussed.

  19. (1R*,2S*,4S*,5R*)-Cyclo­hexane-1,2:4,5-tetra­carb­oxy­lic dianhydride

    PubMed Central

    Uchida, Akira; Hasegawa, Masatoshi; Takezawa, Eiichiro; Yamaguchi, Shinya; Ishikawa, Atsushi; Kagayama, Takashi

    2012-01-01

    The title compound, C10H8O6, a promising raw material to obtain colorless polyimides which are applied to microelectronic and optoelectronic devices, adopts a folded conformation in which the dihedral angle between the two anhydro rings is 55.15 (8)°. The central six-membered ring assumes a conformation inter­mediate between boat and twist-boat. In the crystal, mol­ecules are linked by weak C—H⋯O inter­actions, forming a layer parallel to the bc plane. PMID:22412496

  20. Controlled crystallization of β-In2S3 in 65GeS2ṡ25In2S3ṡ10CsCl chalcohalide glass

    NASA Astrophysics Data System (ADS)

    Li, Zhuobin; Lin, Changgui; Nie, Qiuhua; Dai, Shixun

    2013-09-01

    65GeS2ṡ25In2S3ṡ10CsCl chalcohalide glass-ceramics containing β-In2S3 crystallites in the glassy matrix were prepared by traditional melt-quenching and subsequent heat-treatment at a fairly low temperature ( T g +10 ∘C) for different durations. The transmission spectra show that the cut-off edge of short wavelength is red-shifted with the prolongation of annealing time, but remains an excellent transmittance in the mid-IR region. Meanwhile, its crystallization behavior was investigated systematically. The results show that the precipitation of β-In2S3 crystal phase is responsible for the first crystallization peak, and the second crystal phase is GeS2, which precipitated in the interior after a heat treatment at a high temperature ( T g +70 ∘C). Furthermore, the crystallization mechanism was investigated using the non-isothermal method. The crystallization rate constant K value of 6.08×10-4 s-1 at 346 ∘C for the β-In2S3 phase is about three times larger than that of the GeS2 phase, indicating a much easier crystallization mechanism of β-In2S3 phase. Therefore, it is easy to control the precipitation of sole β-In2S3 crystallite, and to avoid interference of the second crystal phase GeS2.

  1. Is there an ACE ID - ACTN3 R577X polymorphisms interaction that influences sprint performance?

    PubMed

    Eynon, N; Alves, A J; Yamin, C; Sagiv, M; Duarte, J A; Oliveira, J; Ayalon, M; Goldhammer, E; Sagiv, M; Meckel, Y

    2009-12-01

    Functional R577X (rs.1815739) and ID (rs.5186) polymorphisms in the alpha-actinin-3 ( ACTN3) and the angiotensin converting enzyme (ACE) genes, respectively, have been associated with sprint performance. The aim of this study was to determine their effect on sprint performance among 81 Israeli sprinters and 240 healthy controls. Results revealed that the ACE II genotype+ ACTN3 R allele (P=0.003 for sprinters vs. controls), and the ACTN3 RR genotype +ACE I allele (P=0.001 for sprinters vs. controls) might be the genotype for sprinters. In the whole cohort the probability of ACTN3 RR genotype+ ACE I allele being a sprinter (odds ratio 2.67, 95% confidence interval 1.45-4.93) and of ACE II genotype+ ACTN3 R allele being a sprinter (odds ratio 3.57, 95% confidence interval 1.78-7.15) was significantly higher than that in the controls. In conclusion, the above data suggest that ACE ID/ ACTN3 R577X genotype combination is associated with sprint ability. However, ACE ID/ ACTN3 R577X genotype combination is not related to the level of performance.

  2. The 3R's of Solid Waste & the Population Factor for a Sustainable Planet.

    ERIC Educational Resources Information Center

    Wagner, Joan

    1995-01-01

    Opens with a brief history of human awareness of our effect upon the environment. Culminates with a discussion of a strategy to handle solid wastes. This plan includes the 3R's: (1) source reduction; (2) direct reuse of products; and (3) recycling. Also provides statistics on recycling practices of some countries. (ZWH)

  3. A Counterpart of the Wadati-Konno-Ichikawa Soliton Hierarchy Associated with so(3,R)

    NASA Astrophysics Data System (ADS)

    Ma, Wen-Xiu; Manukure, Solomon; Zheng, Hong-Chan

    2014-09-01

    A counterpart of the Wadati-Konno-Ichikawa (WKI) soliton hierarchy, associated with so(3;R), is presented through the zero curvature formulation. Its spectral matrix is defined by the same linear combination of basis vectors as the WKI one, and its Hamiltonian structures yielding Liouville integrability are furnished by the trace identity

  4. SOAR versus SQ3R: A Test of Two Study Systems

    ERIC Educational Resources Information Center

    Jairam, Dharma; Kiewra, Kenneth A.; Rogers-Kasson, Sarah; Patterson-Hazley, Melissa; Marxhausen, Kim

    2014-01-01

    Although researchers have long investigated ways to improve study habits and raise achievement, few studies compare study strategy systems with one another. No study to date has compared the long popular SQ3R (Survey, Question, Read, Recite, Review) system with the more modern SOAR (Select, Organize, Associate, Regulate) system. This study…

  5. InsP3R, the calcium whisperer: Maintaining mitochondrial function in cancer.

    PubMed

    Lovy, Alenka; Foskett, J Kevin; Cárdenas, César

    2016-07-01

    Mitochondrial metabolism is essential to fulfill the large demand for macromolecule biosynthesis in cancer. We recently identified low-level InsP3R-mediated Ca(2+) transfer to mitochondria as an unexpected requirement for mitochondrial function. Here we reveal that its absence specifically targets cancer cells and causes necrosis at daughter cell separation during ongoing proliferation.

  6. Comparison of ICD-10 and DC: 0-3R Diagnoses in Infants, Toddlers and Preschoolers

    ERIC Educational Resources Information Center

    Equit, Monika; Paulus, Frank; Fuhrmann, Pia; Niemczyk, Justine; von Gontard, Alexander

    2011-01-01

    The purpose of this study was to analyze and compare diagnoses of patients from a special outpatient department for infants, toddlers and preschoolers. Specifically, overlap, age and gender differences according to the two classification systems DC: 0-3R and ICD-10 were examined. 299 consecutive children aged 0-5;11 years received both ICD-10 and…

  7. 32 CFR Appendix E to Part 623 - Surety Bond (DA Form 4881-3-R)

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Surety Bond (DA Form 4881-3-R) E Appendix E to Part 623 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY SUPPLIES AND EQUIPMENT LOAN OF ARMY MATERIEL Pt. 623, App. E Appendix E to Part 623—Surety Bond (DA Form...

  8. A kinetic model for type I and II IP3R accounting for mode changes.

    PubMed

    Siekmann, Ivo; Wagner, Larry E; Yule, David; Crampin, Edmund J; Sneyd, James

    2012-08-22

    Based upon an extensive single-channel data set, a Markov model for types I and II inositol trisphosphate receptors (IP(3)R) is developed. The model aims to represent accurately the kinetics of both receptor types of IP(3)R depending on the concentrations of inositol trisphosphate (IP(3)), adenosine trisphosphate (ATP), and intracellular calcium (Ca(2+)). In particular, the model takes into account that for some combinations of ligands the IP(3)R switches between extended periods of inactivity alternating with intervals of bursting activity (mode changes). In a first step, the inactive and active modes are modeled separately. It is found that, within modes, both receptor types are ligand-independent. In a second step, the submodels are connected by transition rates. Ligand-dependent regulation of the channel activity is achieved by modulating these transitions between active and inactive modes. As a result, a compact representation of the IP(3)R is obtained that accurately captures stochastic single-channel dynamics including mode changes in a model with six states and 10 rate constants, only two of which are ligand-dependent.

  9. Structural and electronic features of binary Li2S-P2S5 glasses

    NASA Astrophysics Data System (ADS)

    Ohara, Koji; Mitsui, Akio; Mori, Masahiro; Onodera, Yohei; Shiotani, Shinya; Koyama, Yukinori; Orikasa, Yuki; Murakami, Miwa; Shimoda, Keiji; Mori, Kazuhiro; Fukunaga, Toshiharu; Arai, Hajime; Uchimoto, Yoshiharu; Ogumi, Zempachi

    2016-02-01

    The atomic and electronic structures of binary Li2S-P2S5 glasses used as solid electrolytes are modeled by a combination of density functional theory (DFT) and reverse Monte Carlo (RMC) simulation using synchrotron X-ray diffraction, neutron diffraction, and Raman spectroscopy data. The ratio of PSx polyhedral anions based on the Raman spectroscopic results is reflected in the glassy structures of the 67Li2S-33P2S5, 70Li2S-30P2S5, and 75Li2S-25P2S5 glasses, and the plausible structures represent the lithium ion distributions around them. It is found that the edge sharing between PSx and LiSy polyhedra increases at a high Li2S content, and the free volume around PSx polyhedra decreases. It is conjectured that Li+ ions around the face of PSx polyhedra are clearly affected by the polarization of anions. The electronic structure of the DFT/RMC model suggests that the electron transfer between the P ion and the bridging sulfur (BS) ion weakens the positive charge of the P ion in the P2S7 anions. The P2S7 anions of the weak electrostatic repulsion would causes it to more strongly attract Li+ ions than the PS4 and P2S6 anions, and suppress the lithium ionic conduction. Thus, the control of the edge sharing between PSx and LiSy polyhedra without the electron transfer between the P ion and the BS ion is expected to facilitate lithium ionic conduction in the above solid electrolytes.

  10. The concerted contribution of the S4-S5 linker and the S6 segment to the modulation of a Kv channel by 1-alkanols.

    PubMed

    Bhattacharji, Aditya; Kaplan, Benjamin; Harris, Thanawath; Qu, Xiaoguang; Germann, Markus W; Covarrubias, Manuel

    2006-11-01

    Gating of voltage-gated K(+) channels (K(v) channels) depends on the electromechanical coupling between the voltage sensor and activation gate. The main activation gate of K(v) channels involves the COOH-terminal section of the S6 segment (S6-b) and the S4-S5 linker at the intracellular mouth of the pore. In this study, we have expanded our earlier work to probe the concerted contribution of these regions to the putative amphipathic 1-alkanol site in the Shaw2 K(+) channel. In the S4-S5 linker, we found a direct energetic correlation between alpha-helical propensity and the inhibition of the Shaw2 channel by 1-butanol. Spectroscopic structural analyses of the S4-S5 linker supported this correlation. Furthermore, the analysis of chimeric Shaw2 and K(v)3.4 channels that exchanged their corresponding S4-S5 linkers showed that the potentiation induced by 1-butanol depends on the combination of a single mutation in the S6 PVPV motif (PVAV) and the presence of the Shaw2 S4-S5 linker. Then, using tandem-heterodimer subunits, we determined that this potentiation also depends on the number of S4-S5 linkers and PVAV mutations in the K(v) channel tetramer. Consistent with the critical contribution of the Shaw2 S4-S5 linker, the equivalent PVAV mutation in certain mammalian K(v) channels with divergent S4-S5 linkers conferred weak potentiation by 1-butanol. Overall, these results suggest that 1-alkanol action in Shaw2 channels depends on interactions involving the S4-S5 linker and the S6-b segment. Therefore, we propose that amphiphilic general anesthetic agents such as 1-alkanols may modulate gating of the Shaw2 K(+) channel by an interaction with its activation gate.

  11. The ACTN3 R577X genotype is associated with muscle function in a Japanese population.

    PubMed

    Kikuchi, Naoki; Yoshida, Shou; Min, Seok-ki; Lee, Kihyuk; Sakamaki-Sunaga, Mikako; Okamoto, Takanobu; Nakazato, Koichi

    2015-04-01

    Homozygosity for the common nonsense polymorphism R577X in the α-actinin-3 gene (ACTN3) causes complete α-actinin-3 deficiency in fast-twitch skeletal muscle fibers. This study investigated whether the ACTN3 R577X polymorphism affects fitness status using a battery of tests in a large Japanese cohort. In the present study, 1227 subjects (age: 25-85 years) were genotyped for the ACTN3 R577X polymorphism (rs1815739) using a TaqMan SNP genotyping assay (Applied Biosystems). All subjects were divided into 2 groups based on their age (<55 years and ≥55 years). All subjects completed a questionnaire about exercise habits and were subjected to a battery of tests to assess their fitness status (including grip strength test, chair stand test, and 8-foot walking test). A significant association between the ACTN3 R577X genotype and chair stand test performance was observed in the group of men ≥55 using ANCOVA adjusted for age and exercise habits (p = 0.036). The ACTN3 R577X genotype accounted for 2.5% of the variability in the results of the chair stand test among men in the ≥55 age group. Moreover, for the ≥55 age group, performance in the chair stand test was lower among those with the XX genotype than among those with the RR genotype (p = 0.024) or RX genotype (p = 0.005), unlike results for the <55 age group. No significant difference was noted for hand grip strength or 8-foot walking time. Thus, our results suggest that the ACTN3 R577X genotype is associated with lower-extremity muscle function in the Japanese population.

  12. (3R,4S)-3-Methyl-4-phenyl-2-[(R)-1-phenyl­eth­yl]-3,4-di­hydro­isoquinolin-2-ium tetra­fluorido­borate

    PubMed Central

    Ben Ali, Karim; Retailleau, Pascal

    2014-01-01

    The title salt, C24H24N+·BF4 −, is one of two possible dias­tereoisomers having a different configuration of the asymmetric centre in the α-phenyl­ethyl substituent, whose absolute configuration was established to be R. The two phenyl substituents of the cation have a cofacial orientation, albeit with a long centroid–centroid separation of 4.129 (3) Å. The crystal structure exhibits numerous C—H⋯F contacts between counter-ions, with the tetra­fluorido­borate anion surrounded by five iminium cations. PMID:24764972

  13. Crystal structure of [(2R,3R,4S)-3,4-bis(acet­yloxy)-5-iodo-3,4-di­hydro-2H-pyran-2-yl]methyl acetate

    PubMed Central

    Zukerman-Schpector, Julio; Caracelli, Ignez; Stefani, Hélio A.; Shamim, Anwar; Tiekink, Edward R.T.

    2015-01-01

    In the title compound, C12H15IO7, the 3,4-di­hydro-2H-pyran ring is in a distorted half-boat conformation with the atom bearing the acet­yloxy group adjacent to the C atom bearing the methyl­acetate group lying 0.633 (6) Å above the plane of the remaining ring atoms (r.m.s. deviation = 0.0907 Å). In the crystal, mol­ecules are linked into a supra­molecular chain along the a axis through two C—H⋯O inter­actions to the same acceptor carbonyl O atom; these chains pack with no specific inter­molecular inter­actions between them. PMID:25705505

  14. Remove H/sub 2/S selectively

    SciTech Connect

    Mortko, R.A.

    1984-06-01

    Innovative Selexol process schemes improve H/sub 2/S selectivity and overall CO/sub 2/ recovery for enhanced oil recovery (EOR). Two such schemes, based on use of the Selexol Process show very good economics versus a conventional configuration even at modest CO/sub 2/ product values. These alternate schemes offer two different approaches to enhancing selectivity. One approach illustrates the tremendous effect on plant economics resulting from a small increase in CO/sub 2/ recovery. The other illustrates that CO/sub 2/ recovery levels approaching 99% are not only technically feasible but also economically viable even at very modest CO/sub 2/ product values. The feed gas chosen for evaluation is a typical southwestern Wyoming sour natural gas containing nearly 66% CO/sub 2/, 5% H/sub 2/S, and approximately 8% nitrogen with no hydrocarbons other than methane. Desired products are CO/sub 2/ for use in EOR, H/sub 2/S for sulfur recovery and methane as a product sales gas. Excess nitrogen in the methane sales gas stream is rejected to atmosphere. The Selexol Solvent Process is an excellent choice for treating this gas considering the need for selective acid gas removal, the high acid gas partial pressures and the absence of any ''heavy ends'' in the feed gas.

  15. Synthesis, crystal and electronic structure, and optical property of the pentanary chalcohalide Ba3KSb4S9Cl

    NASA Astrophysics Data System (ADS)

    Zhao, Hua-Jun; Liu, Peng-Fei

    2015-12-01

    The pentanary chalcohalide Ba3KSb4S9Cl has been prepared from stoichiometric mixtures of KCl, Ba, Sb, and S in an evacuated silica tube, which is the first example of chalcohalides in the pentanary A/Ae/Sb/Q/X (A=alkali metal; Ae=alkaline-earth metal; Q=S, Se, Te; X=F, Cl, Br, I) system. This material crystallize in the Pnnm space group and its new structure type comprises one-dimensional (1D) [Sb3S7]5- chains running down the [001] direction separated by isolated dimeric Sb2S4 polyhedra, Ba2+, K+, and Cl-, respectively. The optical gap of 1.99 eV for Ba3KSb4S9Cl was deduced from the UV/vis reflectance spectroscopy and DFT study indicates a indirect band gap with an electronic transfer excitation of S 3p to Sb 5p orbital electrons.

  16. OMAC4S- Open Modular Avionics for Space Applications

    NASA Astrophysics Data System (ADS)

    Herpel, H.-J.; Willich, G.; Vogel, T.; Schuettauf, A.; Pletner, S.; Schoen, F.; Fidi, C.; Loetzke, M.; Dittrich, L.; Schuelke, P.; Wolf, T.

    2013-08-01

    Today's spacecraft avionics architecture is characterised by a broad variety of processing modules, operating systems and interfaces for exchanging data between different processing modules. The software that implements most of the satellite functionality has to deal with this fact and is one of the reasons why software has become one of the major cost drivers in satellite projects. Similar problems have triggered developments in other industrial domains like AUTOSAR in the automotive area or Integrated Modular Architecture (IMA) in the aerospace industry [8]. All these initiatives are based on the definition of standards for computing platforms and the interfaces between these platforms. The goals of the Open Modular Avionics Architecture for Space Applications (OMAC4S) initiative started by Astrium, Fraunhofer FOKUS, STI, SYSGO and TTTech are to outline a solution that helps to reduce complexity and costs for space avionics significantly. This initiative is partly funded by the German national space agency (DLR) through the project On-Board Computer System Architecture (OBC-SA). In this paper we describe how standardization and the usage of already proven technologies from other industrial domains will help to limit the effect of the software development on schedule and costs of satellite projects. In addition we will demonstrate a migration path to make these technologies available for space applications.

  17. IP3R, store-operated Ca2+ entry and neuronal Ca2+ homoeostasis in Drosophila.

    PubMed

    Chakraborty, Sumita; Hasan, Gaiti

    2012-02-01

    The IP3R (inositol 1,4,5-trisphosphate receptor) releases Ca2+ from the ER (endoplasmic reticulum) store upon binding to its ligand InsP3, which is thought to be generated by activation of certain membrane-bound G-protein-coupled receptors in Drosophila. Depletion of Ca2+ in the ER store also activates SOCE (store-operated Ca2+ entry) from the extracellular milieu across the plasma membrane, leading to a second rise in cytosolic Ca2+, which is then pumped back into the ER. The role of the IP3R and SOCE in mediating Ca2+ homoeostasis in neurons, their requirement in neuronal function and effect on neuronal physiology and as a consequence behaviour, are reviewed in the present article.

  18. The ACTN3 R577X Polymorphism across Three Groups of Elite Male European Athletes

    PubMed Central

    Eynon, Nir; Ruiz, Jonatan R.; Femia, Pedro; Pushkarev, Vladimir P.; Cieszczyk, Pawel; Maciejewska-Karlowska, Agnieszka; Sawczuk, Marek; Dyatlov, Dmitry A.; Lekontsev, Evgeny V.; Kulikov, Leonid M.; Birk, Ruth

    2012-01-01

    The ACTN3 R577X polymorphism (rs1815739) is a strong candidate to influence elite athletic performance. Yet, controversy exists in the literature owing to between-studies differences in the ethnic background and sample size of the cohorts, the latter being usually low, which makes comparisons difficult. In this case:control genetic study we determined the association between elite athletic status and the ACTN3 R577X polymorphism within three cohorts of European Caucasian men, i.e. Spanish, Polish and Russian [633 cases (278 elite endurance and 355 power athletes), and 808 non-athletic controls]. The odds ratio (OR) of a power athlete harbouring the XX versus the RR genotype compared with sedentary controls was 0.54 [95% confidence interval (CI): 0.34–0.48; P = 0.006]. We also observed that the OR of an endurance athlete having the XX versus the RR genotype compared with power athletes was 1.88 (95%CI: 1.07–3.31; P = 0.028). In endurance athletes, the OR of a “world-class” competitor having the XX genotype versus the RR+RX genotype was 3.74 (95%CI: 1.08–12.94; P = 0.038) compared with those of a lower (“national”) competition level. No association (P>0.1) was noted between the ACTN3 R577X polymorphism and competition level (world-class versus national-level) in power athletes. Our data provide comprehensive support for the influence of the ACTN3 R577X polymorphism on elite athletic performance. PMID:22916217

  19. ACTN3 R577X genotype is associated with sprinting in elite Japanese athletes.

    PubMed

    Mikami, E; Fuku, N; Murakami, H; Tsuchie, H; Takahashi, H; Ohiwa, N; Tanaka, H; Pitsiladis, Y P; Higuchi, M; Miyachi, M; Kawahara, T; Tanaka, M

    2014-02-01

    The ACTN3 R577X genotype has been found to associate with sprint/power phenotypes in all elite athlete cohorts investigated. This association has not been extensively studied in elite Asian athletes. The present study was undertaken to investigate the association between the ACTN3 R577X genotype and elite Japanese track and field athlete status. 299 elite Japanese track and field athletes (134 sprint/power athletes; 165 endurance/middle-power athletes) and 649 Japanese controls were genotyped for the ACTN3 R577X polymorphism. All athletes were of national or international level. Sprint/power athletes showed a higher frequency of RR + RX genotype than controls (111/134 [82.8%] vs. 478/649 [73.7%], P = 0.025 under the R-dominant model), while there was no significant difference between endurance/middle-power athletes and controls (126/165 [76.4%] vs. 478/649 [73.7%], P = 0.48 under the R-dominant model). Sprinters with the RR + RX genotype had significantly faster personal best times for the 100 m than those with XX genotype (10.42 ± 0.05 s vs. 10.64 ± 0.09 s, P = 0.042); no such association was found in the 400 m sprinters (47.02 ± 0.36 s vs. 47.56 ± 0.99 s, P = 0.62). ACTN3 R577X genotype is associated with sprint/power performance in elite Japanese track and field athletes, especially short sprint performance.

  20. UTILITY ADVANCED TURBINE SYSTEMS (ATS) TECHNOLOGY READINESS TESTING PHASE 3 RESTRUCTURED (3R)

    SciTech Connect

    Unknown

    2000-03-17

    This scope document defines the work scope for accomplishing the design of the GE MS7001H and MS9001H (7H and 9H) combined-cycle power systems under the original ATS Phase 3 DOE Cooperative Agreement No. DE-FC21-95MC31176, and incorporates changes in scope required to convert Phase 3 to the ''restructured'' Phase 3R as defined in Amendment A012 to the Cooperative Agreement.

  1. [Characteristics of acid red 3R wastewater treatment by ozone microbubbles].

    PubMed

    Zhang, Jing; Du, Ya-Wei; Liu, Xiao-Jing; Zhou, Yu-Wen; Liu, Chun; Yang, Jing-Liang; Zhang, Lei

    2015-02-01

    The application of microbubble technology for ozonation wastewater treatment could enhance ozone mass transfer, improve ozonation performance and increase ozone utilization efficiency. The ozone microbubbles were used to treat synthetic acid red 3R wastewater in the present study, and compared to ozone conventional bubbles. The ozone mass transfer and ozonation characteristics of acid red 3R were investigated when ozone microbubbles and ozone conventional bubbles were applied. The results confirmed the enhanced ozone mass transfer using microbubbles. The ozone mass transfer coefficient using microbubbles was 3.6 times higher than that using conventional bubbles under the same conditions. Simultaneously, the ozone decomposition coefficient using microbubbles was 6.2 times higher than that using conventional bubbles, which would be favorable for *OH generation. The ozonation rate and mineralization efficiency of acid red 3R could be improved significantly using ozone microbubbles. A TOC removal efficiency of 78.0% was achieved using ozone microbubbles, which was about 2 times higher than that using ozone conventional bubbles. The ozone utilization efficiency using microbubbles was much higher that using conventional bubbles during ozonation treatment of acid red 3R. The average ozone utilization efficiencies were 97.8% and 69.3% when microbubbles and conventional bubbles were used, respectively. The oxidative ability of ozone microbubbles could be increased by enhancing *OH generation, and as a result, the oxidative reaction of degradation intermediates was accelerated by ozone microbubbles. Especially, the mineralization ability of small organic acid intermediates using ozone microbubbles was about 1.6 times higher than that using ozone conventional bubbles.

  2. Insulin resistance uncoupled from dyslipidemia due to C-terminal PIK3R1 mutations

    PubMed Central

    Huang-Doran, Isabel; Tomlinson, Patsy; Payne, Felicity; Gast, Alexandra; Sleigh, Alison; Bottomley, William; Harris, Julie; Daly, Allan; Rocha, Nuno; Rudge, Simon; Clark, Jonathan; Kwok, Albert; Romeo, Stefano; McCann, Emma; Müksch, Barbara; Dattani, Mehul; Zucchini, Stefano; Wakelam, Michael; Foukas, Lazaros C.; Savage, David B.; Murphy, Rinki; O’Rahilly, Stephen; Semple, Robert K.

    2016-01-01

    Obesity-related insulin resistance is associated with fatty liver, dyslipidemia, and low plasma adiponectin. Insulin resistance due to insulin receptor (INSR) dysfunction is associated with none of these, but when due to dysfunction of the downstream kinase AKT2 phenocopies obesity-related insulin resistance. We report 5 patients with SHORT syndrome and C-terminal mutations in PIK3R1, encoding the p85α/p55α/p50α subunits of PI3K, which act between INSR and AKT in insulin signaling. Four of 5 patients had extreme insulin resistance without dyslipidemia or hepatic steatosis. In 3 of these 4, plasma adiponectin was preserved, as in insulin receptor dysfunction. The fourth patient and her healthy mother had low plasma adiponectin associated with a potentially novel mutation, p.Asp231Ala, in adiponectin itself. Cells studied from one patient with the p.Tyr657X PIK3R1 mutation expressed abundant truncated PIK3R1 products and showed severely reduced insulin-stimulated association of mutant but not WT p85α with IRS1, but normal downstream signaling. In 3T3-L1 preadipocytes, mutant p85α overexpression attenuated insulin-induced AKT phosphorylation and adipocyte differentiation. Thus, PIK3R1 C-terminal mutations impair insulin signaling only in some cellular contexts and produce a subphenotype of insulin resistance resembling INSR dysfunction but unlike AKT2 dysfunction, implicating PI3K in the pathogenesis of key components of the metabolic syndrome. PMID:27766312

  3. PIK3R1 Mutations Cause Syndromic Insulin Resistance with Lipoatrophy

    PubMed Central

    Thauvin-Robinet, Christel; Auclair, Martine; Duplomb, Laurence; Caron-Debarle, Martine; Avila, Magali; St-Onge, Judith; Le Merrer, Martine; Le Luyer, Bernard; Héron, Delphine; Mathieu-Dramard, Michèle; Bitoun, Pierre; Petit, Jean-Michel; Odent, Sylvie; Amiel, Jeanne; Picot, Damien; Carmignac, Virginie; Thevenon, Julien; Callier, Patrick; Laville, Martine; Reznik, Yves; Fagour, Cédric; Nunes, Marie-Laure; Capeau, Jacqueline; Lascols, Olivier; Huet, Frédéric; Faivre, Laurence; Vigouroux, Corinne; Rivière, Jean-Baptiste

    2013-01-01

    Short stature, hyperextensibility of joints and/or inguinal hernia, ocular depression, Rieger anomaly, and teething delay (SHORT) syndrome is a developmental disorder with an unknown genetic cause and hallmarks that include insulin resistance and lack of subcutaneous fat. We ascertained two unrelated individuals with SHORT syndrome, hypothesized that the observed phenotype was most likely due to de novo mutations in the same gene, and performed whole-exome sequencing in the two probands and their unaffected parents. We then confirmed our initial observations in four other subjects with SHORT syndrome from three families, as well as 14 unrelated subjects presenting with syndromic insulin resistance and/or generalized lipoatrophy associated with dysmorphic features and growth retardation. Overall, we identified in nine affected individuals from eight families de novo or inherited PIK3R1 mutations, including a mutational hotspot (c.1945C>T [p.Arg649Trp]) present in four families. PIK3R1 encodes the p85α, p55α, and p50α regulatory subunits of class IA phosphatidylinositol 3 kinases (PI3Ks), which are known to play a key role in insulin signaling. Functional data from fibroblasts derived from individuals with PIK3R1 mutations showed severe insulin resistance for both proximal and distal PI3K-dependent signaling. Our findings extend the genetic causes of severe insulin-resistance syndromes and provide important information with respect to the function of PIK3R1 in normal development and its role in human diseases, including growth delay, Rieger anomaly and other ocular affections, insulin resistance, diabetes, paucity of fat, and ovarian cysts. PMID:23810378

  4. Simultaneous all-optical 3R regeneration scheme with improved scalability using TOAD

    NASA Astrophysics Data System (ADS)

    Huang, Yue-Kai; Glesk, Ivan; Shankar, Raji; Prucnal, Paul R.

    2006-10-01

    A novel re-timing, re-amplifying, and re-shaping (3R) regeneration system is proposed to process multiple WDM (wavelengthdivision-multiplexing) channels simultaneously. Its re-timing capability is investigated by both simulation and experiment with polarizationscrambling method at 10 Gb/s bit rate. Jitter tolerance up to 0.8 UIpp is demonstrated with BER improvement and floor breaking ability.

  5. A3R Phage and Staphylococcus aureus Lysate Do Not Induce Neutrophil Degranulation

    PubMed Central

    Borysowski, Jan; Międzybrodzki, Ryszard; Wierzbicki, Piotr; Kłosowska, Danuta; Korczak-Kowalska, Grażyna; Weber-Dąbrowska, Beata; Górski, Andrzej

    2017-01-01

    The objective of this study was to evaluate the effects of A3R phage and Staphylococcus aureus lysate obtained after phage infection on neutrophil degranulation. The exocytosis of primary and secondary granules from neutrophils was investigated in vitro in whole blood specimens by flow cytometry based on the expression of specific markers of exocytosis (CD63 for primary granules and CD66b for secondary granules). We found that both A3R and S. aureus lysate had no significant effect on the exocytosis of primary and secondary granules. These data suggest that neither A3R virions nor any products of phage-induced lysis of S. aureus are likely to induce neutrophil degranulation in patients who are treated with phage preparations. Since neutrophil granules contain some potentially toxic proteins, our results provide an important argument for the safety of phage therapy. Moreover, these data indicate that the induction of neutrophil degranulation is not likely to contribute to antibacterial effects of phages. PMID:28230780

  6. Correlation between magnon and magnetic symmetries of hexagonal RMnO3 (R = Er, Ho, Lu)

    NASA Astrophysics Data System (ADS)

    Nguyen, Thi Minh Hien; Nguyen, Thi Huyen; Chen, Xiang-Bai; Park, Yeonju; Jung, Young Mee; Lee, D.; Noh, T. W.; Cheong, Sang-Wook; Yang, In-Sang

    2016-11-01

    The correlation between the magnon scattering and the magnetic symmetries of hexagonal RMnO3 (R = Er, Ho) thin films and LuMnO3 single crystal was studied through the 2D Correlation Spectroscopy (2D COS) and Perturbation-Correlation Moving Window 2D (PCMW2D) Correlation Spectroscopy which were performed on the temperature-dependent Raman spectra of RMnO3 (R = Er, Ho, Lu). From the Raman spectra, we observed much stronger intensity and more asymmetrical magnon peak in LuMnO3 single crystal than in ErMnO3 and HoMnO3 thin films. While the ratio between magnon and phonon's linewidth of LuMnO3 and HoMnO3 display an anomalous behavior, that ratio of ErMnO3 is almost stable. The result from PCMW2D also supports these results. In addition, our 2D COS analysis showed that there are more overlap peaks in broad four-spin flipping magnon peak in LuMnO3 than that in ErMnO3 and HoMnO3. The differences of hexagonal RMnO3 (R = Er, Ho, Lu) in magnon scattering are very similar to the actual differences of the magnetic symmetries of these compounds. Therefore, we suggest that the magnon scattering of hexagonal RMnO3 is strongly correlated with the magnetic symmetries of these materials.

  7. Shared functional defect in IP3R-mediated calcium signaling in diverse monogenic autism syndromes

    PubMed Central

    Schmunk, G; Boubion, B J; Smith, I F; Parker, I; Gargus, J J

    2015-01-01

    Autism spectrum disorder (ASD) affects 2% of children, and is characterized by impaired social and communication skills together with repetitive, stereotypic behavior. The pathophysiology of ASD is complex due to genetic and environmental heterogeneity, complicating the development of therapies and making diagnosis challenging. Growing genetic evidence supports a role of disrupted Ca2+ signaling in ASD. Here, we report that patient-derived fibroblasts from three monogenic models of ASD—fragile X and tuberous sclerosis TSC1 and TSC2 syndromes—display depressed Ca2+ release through inositol trisphosphate receptors (IP3Rs). This was apparent in Ca2+ signals evoked by G protein-coupled receptors and by photoreleased IP3 at the levels of both global and local elementary Ca2+ events, suggesting fundamental defects in IP3R channel activity in ASD. Given the ubiquitous involvement of IP3R-mediated Ca2+ signaling in neuronal excitability, synaptic plasticity, gene expression and neurodevelopment, we propose dysregulated IP3R signaling as a nexus where genes altered in ASD converge to exert their deleterious effect. These findings highlight potential pharmaceutical targets, and identify Ca2+ screening in skin fibroblasts as a promising technique for early detection of individuals susceptible to ASD. PMID:26393489

  8. Possible charge disproportionation in 3R-AgNiO2 studied by neutron powder diffraction

    NASA Astrophysics Data System (ADS)

    Chung, J.-H.; Lim, J.-H.; Shin, Y. J.; Kang, J.-S.; Jaiswal-Nagar, D.; Kim, K. H.

    2008-12-01

    Using neutron-scattering techniques, we have investigated the nuclear and the magnetic structures of the triangular antiferromagnet 3R-AgNiO2 . The symmetry analysis based on the group theory suggests that the 3×3 charge order proposed for 2H-AgNiO2 [E. Wawrzyńska , Phys. Rev. Lett. 99, 157204 (2007)] will have a monoclinic symmetry if present in the trigonal lattice of 3R-AgNiO2 . The Rietveld refinement shows that symmetry reduction in the NiO2 layer is consistent with the prediction of the group theory. The pair density function consistently shows that the nearest-neighbor Ni-O bonds split into two groups separated by approximately 0.1Å . The antiferromagnetic Bragg peaks observed below TN=25K can be described by the propagation vector k=(0,1,0) of the monoclinic unit cell. The similarities of the local structure and the antiferromagnetic order strongly suggest that the novel charge order observed in 2H-AgNiO2 also exists in 3R-AgNiO2 .

  9. Validating Vegetable Production Unit (VPU) Plants, Protocols, Procedures and Requirements (P3R) using Currently Existing Flight Resources

    NASA Technical Reports Server (NTRS)

    Bingham, Gail; Bates, Scott; Bugbee, Bruce; Garland, Jay; Podolski, Igor; Levinskikh, Rita; Sychev, Vladimir; Gushin, Vadim

    2009-01-01

    Validating Vegetable Production Unit (VPU) Plants, Protocols, Procedures and Requirements (P3R) Using Currently Existing Flight Resources (Lada-VPU-P3R) is a study to advance the technology required for plant growth in microgravity and to research related food safety issues. Lada-VPU-P3R also investigates the non-nutritional value to the flight crew of developing plants on-orbit. The Lada-VPU-P3R uses the Lada hardware on the ISS and falls under a cooperative agreement between National Aeronautics and Space Administration (NASA) and the Russian Federal Space Association (FSA). Research Summary: Validating Vegetable Production Unit (VPU) Plants, Protocols, Procedures and Requirements (P3R) Using Currently Existing Flight Resources (Lada-VPU-P3R) will optimize hardware and

  10. GacS-dependent production of 2R, 3R-butanediol by Pseudomonas chlororaphis O6 is a major determinant for eliciting systemic resistance against Erwinia carotovora but not against Pseudomonas syringae pv. tabaci in tobacco.

    PubMed

    Han, Song Hee; Lee, Seung Je; Moon, Jae Hak; Park, Keun Hyung; Yang, Kwang Yeol; Cho, Balk Ho; Kim, Kil Yong; Kim, Yong Whan; Lee, Myung Chul; Anderson, Anne J; Kim, Young Cheol

    2006-08-01

    Root colonization by a plant-beneficial rhizobacterium, Pseudomonas chlororaphis O6, induces disease resistance in tobacco against leaf pathogens Erwinia carotovora subsp. carotovora SCC1, causing soft-rot, and Pseudomonas syringae pv. tabaci, causing wildfire. In order to identify the bacterial determinants involved in induced systemic resistance against plant diseases, extracellular components produced by the bacterium were fractionated and purified. Factors in the culture filtrate inducing systemic resistance were retained in the aqueous fraction rather than being partitioned into ethyl acetate. Fractionation on high-performance liquid chromatography followed by nuclear magnetic resonance mass spectrometry analysis identified the active compound as 2R, 3R-butanediol. 2R, 3R butanediol induced systemic resistance in tobacco to E. carotovora subsp. carotovora SCC1, but not to P. syringae pv. tabaci. Treatment of tobacco with the volatile 2R, 3R-butanediol enhanced aerial growth, a phenomenon also seen in plants colonized by P. chlororaphis O6. The isomeric form of the butanediol was important because 2S, 3S-butandiol did not affect the plant. The global sensor kinase, GacS, of P. chlororaphis O6 was a key regulator for induced systemic resistance against E. carotovora through regulation of 2R, 3R-butanediol production. This is the first report of the production of these assumed fermentation products by a pseudomonad and the role of the sensor kinase GacS in production of 2R, 3R-butanediol.

  11. QI2S - Quick Image Interpretation System

    NASA Astrophysics Data System (ADS)

    Naghmouchi, Jamin; Aviely, Peleg; Ginosar, Ran; Ober, Giovanna; Bischoff, Ole; Nadler, Ron; Guiser, David; Citroen, Meira; Freddi, Riccardo; Berekovic, Mladen

    2015-09-01

    The evolution of the Earth Observation mission will be driven by many factors, and the deveploment of new processing paradigms to facilitate data downlink, handling and storage will be a key factor. Next generation EO satellites will generate a great amount of data at a very high data rate, both radar and optical. Real-time onboard processing can be the solution to reduce data downlink and management on ground. Radiometric, geometric, and atmospheric corrections of EO data as well as material/object detection in addition to the well-known needs for image compression and signal processing can be performed directly on board and the aim of QI2S project is to demonstrate this. QI2S, a concept prototype system for novel onboard image processing and image interpretation which has been designed, developed and validated in the framework of an EU FP7 project, targets these needs and makes a significant step towards exceeding current roadmaps of leading space agencies for future payload processors. The QI2S system features multiple chip components of the RC64, a novel rad-hard 64-core signal processing chip, which targets DSP performance of 75 GMACs (16bit), 150 GOPS and 38 single precision GFLOPS while dissipating less than 10 Watts. It integrates advanced DSP cores with a multibank shared memory and a hardware scheduler, also supporting DDR2/3 memory and twelve 3.125 Gbps full duplex high-speed serial links using SpaceFibre and other protocols. The processor is being developed within the European FP7 Framework Program and will be qualified to the highest space standards.

  12. IP3R2 levels dictate the apoptotic sensitivity of diffuse large B-cell lymphoma cells to an IP3R-derived peptide targeting the BH4 domain of Bcl-2.

    PubMed

    Akl, H; Monaco, G; La Rovere, R; Welkenhuyzen, K; Kiviluoto, S; Vervliet, T; Molgó, J; Distelhorst, C W; Missiaen, L; Mikoshiba, K; Parys, J B; De Smedt, H; Bultynck, G

    2013-05-16

    Disrupting inositol 1,4,5-trisphosphate (IP3) receptor (IP3R)/B-cell lymphoma 2 (Bcl-2) complexes using a cell-permeable peptide (stabilized TAT-fused IP3R-derived peptide (TAT-IDP(S))) that selectively targets the BH4 domain of Bcl-2 but not that of B-cell lymphoma 2-extra large (Bcl-Xl) potentiated pro-apoptotic Ca(2+) signaling in chronic lymphocytic leukemia cells. However, the molecular mechanisms rendering cancer cells but not normal cells particularly sensitive to disrupting IP3R/Bcl-2 complexes are poorly understood. Therefore, we studied the effect of TAT-IDP(S) in a more heterogeneous Bcl-2-dependent cancer model using a set of 'primed to death' diffuse large B-cell lymphoma (DL-BCL) cell lines containing elevated Bcl-2 levels. We discovered a large heterogeneity in the apoptotic responses of these cells to TAT-IDP(S) with SU-DHL-4 being most sensitive and OCI-LY-1 being most resistant. This sensitivity strongly correlated with the ability of TAT-IDP(S) to promote IP3R-mediated Ca(2+) release. Although total IP3R-expression levels were very similar among SU-DHL-4 and OCI-LY-1, we discovered that the IP3R2-protein level was the highest for SU-DHL-4 and the lowest for OCI-LY-1. Strikingly, TAT-IDP(S)-induced Ca(2+) rise and apoptosis in the different DL-BCL cell lines strongly correlated with their IP3R2-protein level, but not with IP3R1-, IP3R3- or total IP3R-expression levels. Inhibiting or knocking down IP3R2 activity in SU-DHL-4-reduced TAT-IDP(S)-induced apoptosis, which is compatible with its ability to dissociate Bcl-2 from IP3R2 and to promote IP3-induced pro-apoptotic Ca(2+) signaling. Thus, certain chronically activated B-cell lymphoma cells are addicted to high Bcl-2 levels for their survival not only to neutralize pro-apoptotic Bcl-2-family members but also to suppress IP3R hyperactivity. In particular, cancer cells expressing high levels of IP3R2 are addicted to IP3R/Bcl-2 complex formation and disruption of these complexes using peptide tools

  13. X-ray snapshots of possible intermediates in the time course of synthesis and degradation of protein-bound Fe4S4 clusters

    PubMed Central

    Nicolet, Yvain; Rohac, Roman; Martin, Lydie; Fontecilla-Camps, Juan C.

    2013-01-01

    Fe4S4 clusters are very common versatile prosthetic groups in proteins. Their redox property of being sensitive to O2-induced oxidative damage is, for instance, used by the cell to sense oxygen levels and switch between aerobic and anaerobic metabolisms, as exemplified by the fumarate, nitrate reduction regulator (FNR). Using the hydrogenase maturase HydE from Thermotoga maritima as a template, we obtained several unusual forms of FeS clusters, some of which are associated with important structural changes. These structures represent intermediate states relevant to both FeS cluster assembly and degradation. We observe one Fe2S2 cluster bound by two cysteine persulfide residues. This observation lends structural support to a very recent Raman study, which reported that Fe4S4-to-Fe2S2 cluster conversion upon oxygen exposure in FNR resulted in concomitant production of cysteine persulfide as cluster ligands. Similar persulfide ligands have been observed in vitro for several other Fe4S4 cluster-containing proteins. We have also monitored FeS cluster conversion directly in our protein crystals. Our structures indicate that the Fe4S4-to-Fe2S2 change requires large structural modifications, which are most likely responsible for the dimer–monomer transition in FNR. PMID:23596207

  14. Comparison of gating dynamics of different IP3R channels with immune algorithm searching for channel parameter distributions

    NASA Astrophysics Data System (ADS)

    Cai, Xiuhong; Li, Xiang; Qi, Hong; Wei, Fang; Chen, Jianyong; Shuai, Jianwei

    2016-10-01

    The gating properties of the inositol 1, 4, 5-trisphosphate (IP3) receptor (IP3R) are determined by the binding and unbinding capability of Ca2+ ions and IP3 messengers. With the patch clamp experiments, the stationary properties have been discussed for Xenopus oocyte type-1 IP3R (Oo-IP3R1), type-3 IP3R (Oo-IP3R3) and Spodoptera frugiperda IP3R (Sf-IP3R). In this paper, in order to provide insights about the relation between the observed gating characteristics and the gating parameters in different IP3Rs, we apply the immune algorithm to fit the parameters of a modified DeYoung-Keizer model. By comparing the fitting parameter distributions of three IP3Rs, we suggest that the three types of IP3Rs have the similar open sensitivity in responding to IP3. The Oo-IP3R3 channel is easy to open in responding to low Ca2+ concentration, while Sf-IP3R channel is easily inhibited in responding to high Ca2+ concentration. We also show that the IP3 binding rate is not a sensitive parameter for stationary gating dynamics for three IP3Rs, but the inhibitory Ca2+ binding/unbinding rates are sensitive parameters for gating dynamics for both Oo-IP3R1 and Oo-IP3R3 channels. Such differences may be important in generating the spatially and temporally complex Ca2+ oscillations in cells. Our study also demonstrates that the immune algorithm can be applied for model parameter searching in biological systems.

  15. Two X-ray pulsars: 2S 1145-619 and 1E 1145.1-6141. [indentified with imaging proportional counter

    NASA Technical Reports Server (NTRS)

    Lamb, R. C.; Markert, T. H.; Hartman, R. C.; Thompson, D. J.; Bignami, G. F.

    1980-01-01

    Observations from the Einstein observatory reveal a previously unreported source, 1e1145.1-6141, within 15 arcmin of 2s1145-619 and of comparable intensity during July 1979. Periodicity analysis of the data shows a 290 + or - 2s period for the 2s source and a 298 + or - 4s period for the lE source, confirming the previous Ariel V report of two periods in this range from this region of the sky.

  16. 3R phase of MoS2 and WS2 outperforms the corresponding 2H phase for hydrogen evolution.

    PubMed

    Toh, Rou Jun; Sofer, Zdeněk; Luxa, Jan; Sedmidubský, David; Pumera, Martin

    2017-03-09

    Herein, we compare the bulk, 2H and 3R phases of two most prevalent TMD materials: MoS2 and WS2. The 3R phase outperforms its 2H phase counterpart in hydrogen evolution reaction catalysis and is even comparable with the exfoliated, 1T phase in the case of MoS2.

  17. Synthesis and optical properties of Ga 2S 3-Na 2S-CsCl glasses

    NASA Astrophysics Data System (ADS)

    Hehlen, Markus P.; Bennett, Bryan L.; Castro, Alonso; Williams, Darrick J.; Tornga, Stephanie C.; Muenchausen, Ross E.

    2010-02-01

    Ga 2S 3-Na 2S-CsCl (GNC) glasses were synthesized in open crucibles under inert atmosphere. The evaporative loss of CsCl during glass melting was measured by energy-dispersive X-ray spectroscopy and corrected for by biasing the CsCl concentration in the mixture of starting materials to obtain glasses with accurately controlled stoichiometry. Glass-transition temperatures, refractive-index dispersions, visible and near-infrared transmittance, and band edge energies were measured for four GNC glasses with varying CsCl content, and the respective values were found to significantly improve over earlier studies that did not mitigate CsCl evaporative losses. Glass durability was assessed by a water immersion test at 74 °C. A respective weight loss rate of 39.2 ± 0.3 μg/(cm 2 h) was found for a GNC glass containing 14 mol% CsCl, indicating good glass durability despite the high CsCl content. The refractive-index dispersion measurements indicate that the Cs + and Cl - radii are 16% larger in GNC glass than in bulk crystalline CsCl. The band edge energy increases from 2.97 eV in Ga 2S 3-Na 2S glass to 3.32 eV in Ga 2S 3-Na 2S-CsCl glass containing 20 mol% CsCl as a result of introducing Cl - ions having a large optical electronegativity. The large bandgap of 3.32 eV, the low (450 cm -1) phonon energy, and the good chemical durability make GNC glass an attractive host material for rare-earth ions with radiative transitions in the near ultra-violet, visible, and near-infrared spectral regions.

  18. Docking-undocking combination applied to the D3R Grand Challenge 2015.

    PubMed

    Ruiz-Carmona, Sergio; Barril, Xavier

    2016-09-01

    Novel methods for drug discovery are constantly under development and independent exercises to test and validate them for different goals are extremely useful. The drug discovery data resource (D3R) Grand Challenge 2015 offers an excellent opportunity as an external assessment and validation experiment for Computer-Aided Drug Discovery methods. The challenge comprises two protein targets and prediction tests: binding mode and ligand ranking. We have faced both of them with the same strategy: pharmacophore-guided docking followed by dynamic undocking (a new method tested experimentally here) and, where possible, critical assessment of the results based on pre-existing information. In spite of using methods that are qualitative in nature, our results for binding mode and ligand ranking were amongst the best on Hsp90. Results for MAP4K4 were less positive and we track the different performance across systems to the level of previous knowledge about accessible conformational states. We conclude that docking is quite effective if supplemented by dynamic undocking and empirical information (e.g. binding hot spots, productive protein conformations). This setup is well suited for virtual screening, a frequent application that was not explicitly tested in this edition of the D3R Grand Challenge 2015. Protein flexibility remains as the main cause for hard failures.

  19. Docking-undocking combination applied to the D3R Grand Challenge 2015

    NASA Astrophysics Data System (ADS)

    Ruiz-Carmona, Sergio; Barril, Xavier

    2016-09-01

    Novel methods for drug discovery are constantly under development and independent exercises to test and validate them for different goals are extremely useful. The drug discovery data resource (D3R) Grand Challenge 2015 offers an excellent opportunity as an external assessment and validation experiment for Computer-Aided Drug Discovery methods. The challenge comprises two protein targets and prediction tests: binding mode and ligand ranking. We have faced both of them with the same strategy: pharmacophore-guided docking followed by dynamic undocking (a new method tested experimentally here) and, where possible, critical assessment of the results based on pre-existing information. In spite of using methods that are qualitative in nature, our results for binding mode and ligand ranking were amongst the best on Hsp90. Results for MAP4K4 were less positive and we track the different performance across systems to the level of previous knowledge about accessible conformational states. We conclude that docking is quite effective if supplemented by dynamic undocking and empirical information (e.g. binding hot spots, productive protein conformations). This setup is well suited for virtual screening, a frequent application that was not explicitly tested in this edition of the D3R Grand Challenge 2015. Protein flexibility remains as the main cause for hard failures.

  20. A GCSFR/CSF3R zebrafish mutant models the persistent basal neutrophil deficiency of severe congenital neutropenia

    PubMed Central

    Pazhakh, Vahid; Clark, Sharon; Keightley, M. Cristina; Lieschke, Graham J.

    2017-01-01

    Granulocyte colony-stimulating factor (GCSF) and its receptor (GCSFR), also known as CSF3 and CSF3R, are required to maintain normal neutrophil numbers during basal and emergency granulopoiesis in humans, mice and zebrafish. Previous studies identified two zebrafish CSF3 ligands and a single CSF3 receptor. Transient antisense morpholino oligonucleotide knockdown of both these ligands and receptor reduces neutrophil numbers in zebrafish embryos, a technique widely used to evaluate neutrophil contributions to models of infection, inflammation and regeneration. We created an allelic series of zebrafish csf3r mutants by CRISPR/Cas9 mutagenesis targeting csf3r exon 2. Biallelic csf3r mutant embryos are viable and have normal early survival, despite a substantial reduction of their neutrophil population size, and normal macrophage abundance. Heterozygotes have a haploinsufficiency phenotype with an intermediate reduction in neutrophil numbers. csf3r mutants are viable as adults, with a 50% reduction in tissue neutrophil density and a substantial reduction in the number of myeloid cells in the kidney marrow. These csf3r mutants are a new animal model of human CSF3R-dependent congenital neutropenia. Furthermore, they will be valuable for studying the impact of neutrophil loss in the context of other zebrafish disease models by providing a genetically stable, persistent, reproducible neutrophil deficiency state throughout life. PMID:28281657

  1. Site-directed mutagenesis reveals regions implicated in the stability and fiber formation of human λ3r light chains.

    PubMed

    Villalba, Miryam I; Canul-Tec, Juan C; Luna-Martínez, Oscar D; Sánchez-Alcalá, Rosalba; Olamendi-Portugal, Timoteo; Rudiño-Piñera, Enrique; Rojas, Sonia; Sánchez-López, Rosana; Fernández-Velasco, Daniel A; Becerril, Baltazar

    2015-01-30

    Light chain amyloidosis (AL) is a disease that affects vital organs by the fibrillar aggregation of monoclonal light chains. λ3r germ line is significantly implicated in this disease. In this work, we contrasted the thermodynamic stability and aggregation propensity of 3mJL2 (nonamyloidogenic) and 3rJL2 (amyloidogenic) λ3 germ lines. Because of an inherent limitation (extremely low expression), Cys at position 34 of the 3r germ line was replaced by Tyr reaching a good expression yield. A second substitution (W91A) was introduced in 3r to obtain a better template to incorporate additional mutations. Although the single mutant (C34Y) was not fibrillogenic, the second mutation located at CDR3 (W91A) induced fibrillogenesis. We propose, for the first time, that CDR3 (position 91) affects the stability and fiber formation of human λ3r light chains. Using the double mutant (3rJL2/YA) as template, other variants were constructed to evaluate the importance of those substitutions into the stability and aggregation propensity of λ3 light chains. A change in position 7 (P7D) boosted 3rJL2/YA fibrillogenic properties. Modification of position 48 (I48M) partially reverted 3rJL2/YA fibril aggregation. Finally, changes at positions 8 (P8S) or 40 (P40S) completely reverted fibril formation. These results confirm the influential roles of N-terminal region (positions 7 and 8) and the loop 40-60 (positions 40 and 48) on AL. X-ray crystallography revealed that the three-dimensional topology of the single and double λ3r mutants was not significantly altered. This mutagenic approach helped to identify key regions implicated in λ3 AL.

  2. Site-directed Mutagenesis Reveals Regions Implicated in the Stability and Fiber Formation of Human λ3r Light Chains

    SciTech Connect

    Villalba, Miryam I.; Canul-Tec, Juan C.; Luna-Martínez, Oscar D.; Sánchez-Alcalá, Rosalba; Olamendi-Portugal, Timoteo; Rudiño-Piñera, Enrique; Rojas, Sonia; Sánchez-López, Rosana; Fernández-Velasco, Daniel A.; Becerril, Baltazar

    2014-12-11

    Light chain amyloidosis (AL) is a disease that affects vital organs by the fibrillar aggregation of monoclonal light chains. λ3r germ line is significantly implicated in this disease. In this paper, we contrasted the thermodynamic stability and aggregation propensity of 3mJL2 (nonamyloidogenic) and 3rJL2 (amyloidogenic) λ3 germ lines. Because of an inherent limitation (extremely low expression), Cys at position 34 of the 3r germ line was replaced by Tyr reaching a good expression yield. A second substitution (W91A) was introduced in 3r to obtain a better template to incorporate additional mutations. Although the single mutant (C34Y) was not fibrillogenic, the second mutation located at CDR3 (W91A) induced fibrillogenesis. We propose, for the first time, that CDR3 (position 91) affects the stability and fiber formation of human λ3r light chains. Using the double mutant (3rJL2/YA) as template, other variants were constructed to evaluate the importance of those substitutions into the stability and aggregation propensity of λ3 light chains. A change in position 7 (P7D) boosted 3rJL2/YA fibrillogenic properties. Modification of position 48 (I48M) partially reverted 3rJL2/YA fibril aggregation. Finally, changes at positions 8 (P8S) or 40 (P40S) completely reverted fibril formation. These results confirm the influential roles of N-terminal region (positions 7 and 8) and the loop 40–60 (positions 40 and 48) on AL. X-ray crystallography revealed that the three-dimensional topology of the single and double λ3r mutants was not significantly altered. Finally, this mutagenic approach helped to identify key regions implicated in λ3 AL.

  3. Site-directed Mutagenesis Reveals Regions Implicated in the Stability and Fiber Formation of Human λ3r Light Chains

    DOE PAGES

    Villalba, Miryam I.; Canul-Tec, Juan C.; Luna-Martínez, Oscar D.; ...

    2014-12-11

    Light chain amyloidosis (AL) is a disease that affects vital organs by the fibrillar aggregation of monoclonal light chains. λ3r germ line is significantly implicated in this disease. In this paper, we contrasted the thermodynamic stability and aggregation propensity of 3mJL2 (nonamyloidogenic) and 3rJL2 (amyloidogenic) λ3 germ lines. Because of an inherent limitation (extremely low expression), Cys at position 34 of the 3r germ line was replaced by Tyr reaching a good expression yield. A second substitution (W91A) was introduced in 3r to obtain a better template to incorporate additional mutations. Although the single mutant (C34Y) was not fibrillogenic, themore » second mutation located at CDR3 (W91A) induced fibrillogenesis. We propose, for the first time, that CDR3 (position 91) affects the stability and fiber formation of human λ3r light chains. Using the double mutant (3rJL2/YA) as template, other variants were constructed to evaluate the importance of those substitutions into the stability and aggregation propensity of λ3 light chains. A change in position 7 (P7D) boosted 3rJL2/YA fibrillogenic properties. Modification of position 48 (I48M) partially reverted 3rJL2/YA fibril aggregation. Finally, changes at positions 8 (P8S) or 40 (P40S) completely reverted fibril formation. These results confirm the influential roles of N-terminal region (positions 7 and 8) and the loop 40–60 (positions 40 and 48) on AL. X-ray crystallography revealed that the three-dimensional topology of the single and double λ3r mutants was not significantly altered. Finally, this mutagenic approach helped to identify key regions implicated in λ3 AL.« less

  4. Site-directed Mutagenesis Reveals Regions Implicated in the Stability and Fiber Formation of Human λ3r Light Chains*

    PubMed Central

    Villalba, Miryam I.; Canul-Tec, Juan C.; Luna-Martínez, Oscar D.; Sánchez-Alcalá, Rosalba; Olamendi-Portugal, Timoteo; Rudiño-Piñera, Enrique; Rojas, Sonia; Sánchez-López, Rosana; Fernández-Velasco, Daniel A.; Becerril, Baltazar

    2015-01-01

    Light chain amyloidosis (AL) is a disease that affects vital organs by the fibrillar aggregation of monoclonal light chains. λ3r germ line is significantly implicated in this disease. In this work, we contrasted the thermodynamic stability and aggregation propensity of 3mJL2 (nonamyloidogenic) and 3rJL2 (amyloidogenic) λ3 germ lines. Because of an inherent limitation (extremely low expression), Cys at position 34 of the 3r germ line was replaced by Tyr reaching a good expression yield. A second substitution (W91A) was introduced in 3r to obtain a better template to incorporate additional mutations. Although the single mutant (C34Y) was not fibrillogenic, the second mutation located at CDR3 (W91A) induced fibrillogenesis. We propose, for the first time, that CDR3 (position 91) affects the stability and fiber formation of human λ3r light chains. Using the double mutant (3rJL2/YA) as template, other variants were constructed to evaluate the importance of those substitutions into the stability and aggregation propensity of λ3 light chains. A change in position 7 (P7D) boosted 3rJL2/YA fibrillogenic properties. Modification of position 48 (I48M) partially reverted 3rJL2/YA fibril aggregation. Finally, changes at positions 8 (P8S) or 40 (P40S) completely reverted fibril formation. These results confirm the influential roles of N-terminal region (positions 7 and 8) and the loop 40–60 (positions 40 and 48) on AL. X-ray crystallography revealed that the three-dimensional topology of the single and double λ3r mutants was not significantly altered. This mutagenic approach helped to identify key regions implicated in λ3 AL. PMID:25505244

  5. Mutations in PIK3R1 can lead to APDS2, SHORT syndrome or a combination of the two.

    PubMed

    Bravo García-Morato, M; García-Miñaúr, S; Molina Garicano, J; Santos Simarro, F; López-Grandos, E; Ferreira Cerdán, A; Rodríguez Pena, R

    2017-03-13

    Mutations in PIK3R1 gene have been associated to two different conditions: a primary immunodeficiency, called APDS2, of recent description and SHORT syndrome. 47 patients with APDS2 have been reported to date, only one of them sharing both PIK3R1-related phenotypes. Here we describe two more patients affected by APDS2 and SHORT syndrome, which highlights that this association may not be so infrequent. We recommend that patients with mutations in PIK3R1 gene should be assessed by both clinical immunologists and clinical geneticists.

  6. THE DEGREE OF THE TOP SEGRE CLASS OF THE STANDARD VECTOR BUNDLE ON THE HILBERT SCHEME \\operatorname{Hilb}^4 S OF AN ALGEBRAIC SURFACE S

    NASA Astrophysics Data System (ADS)

    Troshina, T. L.

    1994-06-01

    In the present paper we compute the degree of the top Segre class s_8(\\mathscr{E}_D^4) of the standard vector bundle \\mathscr{E}_D^4=q_* p^* \\mathscr{O}_S(D) on the Hilbert scheme \\operatorname{Hilb}^4 S of an algebraic surface S, where D is a divisor on S and S\\overset{p}{\\leftarrow}Z_4\\overset{q}{\\rightarrow}\\operatorname{Hilb}^4S are the natural projections of the universal cycle Z_4\\subset S\\times\\operatorname{Hilb}^4S. This degree is a polynomial with rational coefficients in invariants x, y, z, w of the pair (S, \\mathscr{O}_S(D)), where x= (D^2), y = (D\\cdot K_S), z = s_2(S), w = (K_S^2).

  7. Thermal expansion, heat capacity and magnetostriction of RAl3 (R = Tm, Yb, Lu) single crystals

    SciTech Connect

    Bud'ko, S.; Frenerick, J.; Mun, E.; Canfield, P.; Schmiedeshoff, G.

    2007-12-13

    We present thermal expansion and longitudinal magnetostriction data for cubic RAl{sub 3} (R = Tm, Yb, Lu) single crystals. The thermal expansion coefficient for YbAl{sub 3} is consistent with an intermediate valence of the Yb ion, whereas the data for TmAl{sub 3} show crystal electric field contributions and have strong magnetic field dependences. de Haas-van Alphen like oscillations were observed in the magnetostriction data for YbAl{sub 3} and LuAl{sub 3}, several new extreme orbits were measured and their effective masses were estimated. Specific heat data taken at 0 and 140 kOe for both LuAl{sub 3} and TmAl{sub 3} for T {le} 200 K allow for the determination of a crystal electric field splitting scheme for TmAl{sub 3}.

  8. Magnetochromic effect in multiferroic R In1 -xMnxO3 (R =Tb , Dy)

    NASA Astrophysics Data System (ADS)

    Chen, P.; Holinsworth, B. S.; O'Neal, K. R.; Brinzari, T. V.; Mazumdar, D.; Topping, C. V.; Luo, X.; Cheong, S.-W.; Singleton, J.; McGill, S.; Musfeldt, J. L.

    2015-05-01

    We combined high field magnetization and magneto-optical spectroscopy to investigate spin-charge coupling in Mn-substituted rare-earth indium oxides of chemical formula R In1 -xMnxO3 (R =Tb , Dy). The edge states, on-site Mn3 +d to d excitations, and rare-earth f -manifold excitations all track the magnetization energy due to dominant Zeeman interactions. The field-induced modifications to the rare-earth excitations are quite large because spin-orbit coupling naturally mixes spin and charge, suggesting that the next logical step in the design strategy should be to bring spin-orbit coupling onto the trigonal bipyramidal chromophore site with a 4 or 5 d center.

  9. Full stereochemical understanding in a new (2R,3R,4R)-4-hydroxyisoleucine synthesis.

    PubMed

    Rolland, M; Kassem, T; Rolland, V; Martinez, J

    2001-12-01

    We present the crystal and molecular structures of 2,3,6,7,8,8a-hexahydro-6,8-methano-7,7,8a-trimethyl-3-(1-methyl-2-oxopropylidene)-5H-1,4-benzoxazin-2-one, C16H21NO3, (III), and 2,3,6,7,8,8a-hexahydro-3-(2-hydroxy-1-methylpropyl)-6,8-methano-7,7,8a-trimethyl-5H-1,4-benzoxazin-2-one, C16H25NO3, (V). These compounds are two of the four key intermediates in our synthetic route to (2R,3R,4R)-4-hydroxyisoleucine. The two structures provide a full understanding of the stereochemistry in successive steps. This synthesis was based on a new optically pure chiral oxazinone auxiliary derived from (1R,2R,5R)-2-hydroxypinan-3-one.

  10. Prospective evaluation of shape similarity based pose prediction method in D3R Grand Challenge 2015

    NASA Astrophysics Data System (ADS)

    Kumar, Ashutosh; Zhang, Kam Y. J.

    2016-09-01

    Evaluation of ligand three-dimensional (3D) shape similarity is one of the commonly used approaches to identify ligands similar to one or more known active compounds from a library of small molecules. Apart from using ligand shape similarity as a virtual screening tool, its role in pose prediction and pose scoring has also been reported. We have recently developed a method that utilizes ligand 3D shape similarity with known crystallographic ligands to predict binding poses of query ligands. Here, we report the prospective evaluation of our pose prediction method through the participation in drug design data resource (D3R) Grand Challenge 2015. Our pose prediction method was used to predict binding poses of heat shock protein 90 (HSP90) and mitogen activated protein kinase kinase kinase kinase (MAP4K4) ligands and it was able to predict the pose within 2 Å root mean square deviation (RMSD) either as the top pose or among the best of five poses in a majority of cases. Specifically for HSP90 protein, a median RMSD of 0.73 and 0.68 Å was obtained for the top and the best of five predictions respectively. For MAP4K4 target, although the median RMSD for our top prediction was only 2.87 Å but the median RMSD of 1.67 Å for the best of five predictions was well within the limit for successful prediction. Furthermore, the performance of our pose prediction method for HSP90 and MAP4K4 ligands was always among the top five groups. Particularly, for MAP4K4 protein our pose prediction method was ranked number one both in terms of mean and median RMSD when the best of five predictions were considered. Overall, our D3R Grand Challenge 2015 results demonstrated that ligand 3D shape similarity with the crystal ligand is sufficient to predict binding poses of new ligands with acceptable accuracy.

  11. The ACTN3 R577X Polymorphism Is Associated with Cardiometabolic Fitness in Healthy Young Adults

    PubMed Central

    Deschamps, Chelsea L.; Connors, Kimberly E.; Klein, Matthias S.; Johnsen, Virginia L.; Shearer, Jane; Vogel, Hans J.; Devaney, Joseph M.; Gordish-Dressman, Heather; Many, Gina M.; Barfield, Whitney; Hoffman, Eric P.; Kraus, William E.; Hittel, Dustin S.

    2015-01-01

    Homozygosity for a premature stop codon (X) in the ACTN3 “sprinter” gene is common in humans despite the fact that it reduces muscle size, strength and power. Because of the close relationship between skeletal muscle function and cardiometabolic health we examined the influence of ACTN3 R577X polymorphism over cardiovascular and metabolic characteristics of young adults (n = 98 males, n = 102 females; 23 ± 4.2 years) from our Assessing Inherent Markers for Metabolic syndrome in the Young (AIMMY) study. Both males and females with the RR vs XX genotype achieved higher mean VO2 peak scores (47.8 ± 1.5 vs 43.2 ±1.8 ml/O2/min, p = 0.002) and exhibited higher resting systolic (115 ± 2 vs 105 ± mmHg, p = 0.027) and diastolic (69 ± 3 vs 59 ± 3 mmHg, p = 0.005) blood pressure suggesting a role for ACTN3 in the maintenance of vascular tone. We subsequently identified the expression of alpha-actinin 3 protein in pulmonary artery smooth muscle, which may explain the genotype-specific differences in cardiovascular adaptation to acute exercise. In addition, we utilized targeted serum metabolomics to distinguish between RR and XX genotypes, suggesting an additional role for the ACTN3 R577X polymorphism in human metabolism. Taken together, these results identify significant cardiometabolic effects associated with possessing one or more functional copies of the ACTN3 gene. PMID:26107372

  12. Synthesis and characterization of indium xanthates and their use for the preparation of beta-In2S3 nanoparticles.

    PubMed

    Dutta, Dimple P; Sharma, Garima; Ghoshal, Shamik; Kushwah, Nisha P; Jain, Vimal K

    2006-01-01

    Synthesis and characterization of various classical indium xanthate complexes of the type [InCl(3-n)(S2COR)n] (n = 1, 2, or 3; R = Me, Et, Pr(i), and Bu(s)) have been discussed. Crystalline beta-ln2S3 nanoparticles were obtained by the solvent thermolysis of indium tris-alkylxanthates in ethylene glycol at 196 degrees C, and were characterized by elemental analysis, IR, powder XRD, and XPS techniques. TEM results showed that the size of beta-In2S3 nanoparticles depended on the nature of the precursor used. The optical properties of beta-In2S3 nanocrystals have shown quantum confinement of the excitonic transition.

  13. University of Texas MD Anderson Cancer Center: Characterization of PIK3R1 Neomorphic Mutations | Office of Cancer Genomics

    Cancer.gov

    The goal of this project was to functionally characterize the most frequent mutation of the PIK3R1 gene and to explore potential therapeutic approaches to target the aberration. Read the abstract Experimental Approaches Cytotoxicity Screen

  14. Steady-state photoconductivity of amorphous (As4S3Se3)1-x:Snx films

    NASA Astrophysics Data System (ADS)

    Iaseniuc, O. V.; Iovu, M. S.; Cojocaru, I. A.; Prisacar, A. M.

    2015-02-01

    Amorphous arsenic trisulfide (As2S3) and arsenic triselenide (As2Se3) are among widely investigated amorphous materials due to its interesting electrical, optical and photoelectrical properties. In order to improve the physical properties and recording characteristics, and to extend the spectral range of photosensibility, a special interest represents the mixed amorphous materials, like (As2S3):(As2Se3). Chalcogenide vitreous semiconductors (ChVS) of the As-S-Se system exhibit photostructural transformations with reversible and irreversible properties, and are promising materials as registration media for holography and optical information, for fabrication of diffractive elements, and other optoelectronic applications. Because many optoelectronic devices on amorphous semiconductors are based on the photoconductivity effect, special interests represent investigation of the stationary and non-stationary characteristics of photoconductivity. In this paper the experimental results of steady-state photoconductivity and holographic characteristics of amorphous (As4S3Se3)1-x:Snx thin films are presented. It was shown that the photoconductivity spectra depend on the polarity on the top illuminated electrode and on the Sn concentration in the host glass. The photosensitivity of amorphous ((As4S3Se3)1-x:Snx thin films is almost constant for all Sn-containing glasses. The Moss rule was used for determination of the optical forbidden gap Eg from the photoconductivity spectra. It was demonstrated that the investigated amorphous films are sensitive to the light irradiation and can be used as effective registration media for holographic information. The relaxation of photodarkening in amorphous (As4S3Se3)1-x:Snx thin films was investigated and was shown that the relaxation curves of transmittance T/T0 = f(t) can be described the stretch exponential function T(t)/T(0) = A0+Aexp[-(t-t0)/τ] (1-β) . The kinetics of diffraction efficiency growth η(t) was measured by registration of

  15. Chromosome jumping from D4S10 (G8) toward the Huntington disease gene.

    PubMed Central

    Richards, J E; Gilliam, T C; Cole, J L; Drumm, M L; Wasmuth, J J; Gusella, J F; Collins, F S

    1988-01-01

    The gene for Huntington disease (HD) has been localized to the distal portion of the short arm of human chromosome 4 by linkage analysis. Currently, the two closest DNA markers are D4S10 (G8), located approximately equal to 3 centimorgans centromeric to HD, and D4S43 (C4H), positioned 0-1.5 centimorgans from HD. In an effort to move closer to the HD gene, with the eventual goal of identifying the gene itself, we have applied the technique of chromosome jumping to this region. A 200-kilobase jumping library has been constructed, and a jump from D4S10 has been obtained and its approximate distance verified by pulsed field gel electrophoresis. Two restriction fragment length polymorphisms have been identified at the jump locus, which is denoted D4S81. Linkage analysis of previously identified recombinants between D4S10 and HD or D4S10 and D4S43 shows that in two of five events the jump has crossed the recombination points. This unequivocally orients D4S10 and D4S81 on the chromosome, provides additional markers for HD, and suggests that recombination frequency in this region of chromosome 4 may be increased, so that the physical distance from D4S10 to HD may not be as large as originally suspected. Images PMID:2901098

  16. High temperature neutron powder diffraction study of the Cu12Sb4S13 and Cu4Sn7S16 phases

    NASA Astrophysics Data System (ADS)

    Lemoine, Pierric; Bourgès, Cédric; Barbier, Tristan; Nassif, Vivian; Cordier, Stéphane; Guilmeau, Emmanuel

    2017-03-01

    Ternary copper-containing sulfides Cu12Sb4S13 and Cu4Sn7S16 have attracted considerable interest since few years due to their high-efficiency conversion as absorbers for solar energy and promising thermoelectric materials. We report therein on the decomposition study of Cu12Sb4S13 and Cu4Sn7S16 phases using high temperature in situ neutron powder diffraction. Our results obtained at a heating rate of 2.5 K/min indicate that: (i) Cu12Sb4S13 decomposes above ≈792 K into Cu3SbS3, and (ii) Cu4Sn7S16 decomposes above ≈891 K into Sn2S3 and a copper-rich sulfide phase of sphalerite ZnS-type structure with an assumed Cu3SnS4 stoichiometry. Both phase decompositions are associated to a sulfur volatilization. While the results on Cu12Sb4S13 are in fair agreement with recent published data, the decomposition behavior of Cu4Sn7S16 differs from other studies in terms of decomposition temperature, thermal stability and products of reaction. Finally, the crystal structure refinements from neutron powder diffraction data are reported and discussed for the Cu4Sn7S16 and tetrahedrite Cu12Sb4S13 phases at 300 K, and for the high temperature form of skinnerite Cu3SbS3 at 843 K.

  17. Fluorescent Probes for H2S Detection and Quantification.

    PubMed

    Feng, Wei; Dymock, Brian W

    2015-01-01

    Many diverse, sensitive and structurally novel fluorescent probes have recently been reported for H2S detection. Quantification of H2S requires a selective chemosensor which will react only with H2S against a background of high concentrations of other thiols or reducing agents. Most published probes are able to quantify H2S selectively in a simple in vitro system with the most sensitive probes able to detect H2S at below 100 nM concentrations. A subset of probes also have utility in sensing H2S in living cells, and there are now several with specific sub-cellular localization and a few cases of in vivo applications. Biologists studying H2S now have a wide range of tools to assist them to aid further understanding of the role of H2S in biology.

  18. Characterization of the Testis-specific Proteasome Subunit α4s in Mammals

    PubMed Central

    Uechi, Hiroyuki; Hamazaki, Jun; Murata, Shigeo

    2014-01-01

    The 26 S proteasome is responsible for regulated proteolysis in eukaryotic cells. It is composed of one 20 S core particle (CP) flanked by one or two 19 S regulatory particles. The CP is composed of seven different α-type subunits (α1-α7) and seven different β-type subunits, three of which are catalytic. Vertebrates encode four additional catalytic β subunits that are expressed predominantly in immune tissues and produce distinct subtypes of CPs particularly well suited for the acquired immune system. In contrast, the diversity of α subunits remains poorly understood. Recently, another α subunit, referred to as α4s, was reported. However, little is known about α4s. Here we provide a detailed characterization of α4s and the α4s-containing CP. α4s is exclusively expressed in germ cells that enter the meiotic prophase and is incorporated into the CP in place of α4. A comparison of structural models revealed that the differences in the primary sequences between α4 and α4s are located on the outer surface of the CP, suggesting that α4s interacts with specific molecules via these unique regions. α4s-containing CPs account for the majority of the CPs in mouse sperm. The catalytic β subunits in the α4s-containing CP are β1, β2, and β5, and immunosubunits are not included in the α4s-containing CP. α4s-containing CPs have a set of peptidase activities almost identical to those of α4-containing CPs. Our results provide a basis for understanding the role of α4s and male germ cell-specific proteasomes in mammals. PMID:24668818

  19. Electronic structure and optical properties of orthorhombic and rhombohedral RAlO3 (R = Sm, Nd)

    NASA Astrophysics Data System (ADS)

    Sakhya, Anup Pradhan; Dutta, Alo; Shannigrahi, Santiranjan; Sinha, T. P.

    2015-04-01

    The electronic structure and optical properties of RAlO3 (R = Sm, Nd) have been investigated by full potential linearized augmented plane wave method within the framework of density functional theory in its generalized gradient approximation. The calculations are initiated with the experimental lattice constants obtained by the Rietveld refinement of the XRD data of the synthesized samples. The band gaps of the systems are measured from the UV-visible reflectance spectra using the Kubelka-Munk function and compared with the calculated data. The spin-polarized calculation has been carried out with on-site Coulomb potential U to consider the electron-electron correlation in the system. The X-ray photoemission spectra of the systems are measured. The valence-band density-of-states spectra are generated and compared with the X-ray photoemission spectra. The chemical shifts of these compounds suggest a mixed ionic and covalent character of the bonds. It has been observed that f-state of Nd and Sm hybridizes with O-2p state near the Fermi level in valence band. The Born effective charge tensors of the constituent ions for SmAlO3 and NdAlO3 have also been calculated which shows strong hybridization and charge transfer between Sm and O in SmAlO3 and Nd and O in NdAlO3. The calculated static dielectric tensor is found to be in good agreement with the experimental values.

  20. UTILITY ADVANCED TURBINE SYSTEMS (ATS) TECHNOLOGY READINESS TESTING: PHASE 3R

    SciTech Connect

    1999-09-01

    The overall objective of the Advanced Turbine System (ATS) Phase 3 Cooperative Agreement between GE and the US Department of Energy (DOE) is the development of the GE 7H and 9H combined cycle power systems. The major effort will be expended on detail design. Validation of critical components and technologies will be performed, including: hot gas path component testing, sub-scale compressor testing, steam purity test trials, and rotational heat transfer confirmation testing. Processes will be developed to support the manufacture of the first system, which was to have been sited and operated in Phase 4 but will now be sited and operated commercially by GE. This change has resulted from DOE's request to GE for deletion of Phase 4 in favor of a restructured Phase 3 (as Phase 3R) to include full speed, no load (FSNL) testing of the 7H gas turbine. Technology enhancements that are not required for the first machine design but will be critical for future ATS advances in performance, reliability, and costs will be initiated. Long-term tests of materials to confirm design life predictions will continue. A schematic of the GE H machine is shown. This report summarizes work accomplished in 2Q99.

  1. Relationship Between ACTN3 R577X Polymorphism and Physical Abilities in Polish Athletes.

    PubMed

    Orysiak, Joanna; Busko, Krzysztof; Mazur-RóŻycka, Joanna; Michalski, Radoslaw; Gajewski, Jan; Malczewska-Lenczowska, Jadwiga; Sitkowski, Dariusz

    2015-08-01

    The purpose of this study was to examine the association between α-actinin 3 (ACTN3) R577X polymorphism and physical abilities of male athletes performing various sports (volleyball, ice hockey, canoeing, swimming). One hundred eighty-five subjects were recruited for the study. The following measurements were taken: height of jump and power output in countermovement jump and spike jump (SPJ) and muscle strength of 10 muscle groups. The R577X polymorphism of ACTN3 was typed using polymerase chain reaction restriction fragment length polymorphism. The results showed that RR genotype carriers develop greater power output in SPJ than RX and XX individuals (44.6 ± 11.1, 42.6 ± 11.0, and 38.4 ± 7.9 W·kg(-1) for RR, RX, and XX genotypes, respectively) and height of jump in SPJ (0.537 ± 0.075, 0.523 ± 0.072, and 0.498 ± 0.053 m for RR, RX, and XX genotypes, respectively). Muscle strength did not differ between genotype groups. This suggests that the ACTN3 gene has a greater impact on determining dynamic movements than influencing static muscle strength.

  2. A D3R prospective evaluation of machine learning for protein-ligand scoring

    NASA Astrophysics Data System (ADS)

    Sunseri, Jocelyn; Ragoza, Matthew; Collins, Jasmine; Koes, David Ryan

    2016-09-01

    We assess the performance of several machine learning-based scoring methods at protein-ligand pose prediction, virtual screening, and binding affinity prediction. The methods and the manner in which they were trained make them sufficiently diverse to evaluate the utility of various strategies for training set curation and binding pose generation, but they share a novel approach to classification in the context of protein-ligand scoring. Rather than explicitly using structural data such as affinity values or information extracted from crystal binding poses for training, we instead exploit the abundance of data available from high-throughput screening to approach the problem as one of discriminating binders from non-binders. We evaluate the performance of our various scoring methods in the 2015 D3R Grand Challenge and find that although the merits of some features of our approach remain inconclusive, our scoring methods performed comparably to a state-of-the-art scoring function that was fit to binding affinity data.

  3. Cylindrical crystals of molybdenite-3R:sem- and x-ray investigations

    NASA Astrophysics Data System (ADS)

    Yushkin, N.; Zhabin, A.

    2003-04-01

    Flat faces are the characteristic feature of ionic crystals; nevertheless, among them there are cleavage-faced ones, up to the crystals with cylindrical shapes. More often they occur among minerals with layer structure or minerals with higher tendency to structural defectiveness (cylindrite, franckeite, asbestos, jamesonite, boulangerite and etc.). We studied exotic cylindrical crystals of molybdenite, discovered in the pegmatite veins of Slyudyanogorsky deposit of muscovite in Middle Ural by Kobyashev Yu. S., Zverev G. F. in 1973. Crystals have cylindrical shape, sometimes with sharpened or flattened wedge-shaped edges. Their length is 2-10 mm, diameter 0.8-mm. At the cross section crystals possess concentrically-laminar composition with tabulated axled canal with diameter about 120mkm. Thin layers arise packages about 15 mkm thickness. In the section crystals are fixed up to 6 such packages visually as well as by methods of X-ray phase-dispersed introscopy. According to the data of monocrystal and powder X-ray molybdenite represents as trigonal polytype 3R-R3m with insignificant quantity of hexagonal polytype 2H-P6@3/mmc. Twisting of leaf-like crystalline germs is one of the reasons of formation of cylindrical crystals due to syngenetic shistosity of containing rocks with crystallization.

  4. MC3R gene polymorphisms are associated with early childhood adiposity gain and infant appetite in an Asian population*

    PubMed Central

    Tint, M. T.; Teh, A. L.; Holbrook, J. D.; Quah, P. L.; Chong, M. F.‐F.; Lin, X.; Soh, S. E.; Saw, S.‐M.; Kwek, K.; Godfrey, K. M.; Gluckman, P. D.; Chong, Y. S.; Lek, N.; Yap, F.; Lee, Y. S.

    2015-01-01

    Summary Background Polymorphic variants within human melanocortin‐3 receptor gene (MC3R) gene have been associated with obesity. However, its influence on infancy and early childhood adiposity has not been reported before. Objectives We assessed associations between genotype at polymorphic sites within MC3R with early childhood adiposity and interaction with early childhood appetitive traits. Methods We studied 1090 singletons in an Asian mother–offspring cohort genotyped for MC3R and in a subgroup (n = 422) who had completed Child Eating Behaviour Questionnaires (CEBQ) at 12 months. Children were followed from birth to 48 months, and up to 10 measurements of body mass index and five measures of triceps and subscapular skin‐folds were obtained. Results Independent of potential confounders, each additional MC3R minor allele copy was associated with greater body mass index standard deviation score [B{95% confidence interval}: 0.004 units/month {0.001,0.007}; p = 0.007], triceps [0.009 mm/month {0.001,0.02}; p = 0.021] and subscapular skin‐fold [0.008 mm/month {0.002,0.01}; p = 0.011] gain velocity in the first 48 months. Each additional MC3R minor allele copy was also associated with increased odds of overweight [odds ratio {95% confidence interval}: 1.48{1.17–1.88}] and obesity [1.58{1.10–2.28}] in the first 48 months. Every additional copy of MC3R minor allele was positively associated with ‘slowness‐in‐eating’ appetitive trait [0.24{0.06,0.39}, p = 0.006]; however, the relationship between ‘slowness‐in‐eating’ with adiposity gain was not statistically significant. Conclusions Our findings support the role of MC3R genetic variants in adiposity gain during early childhood. PMID:26663875

  5. Organelle-Targeted H2S Probes Enable Visualization of the Subcellular Distribution of H2S Donors.

    PubMed

    Montoya, Leticia A; Pluth, Michael D

    2016-06-07

    Hydrogen sulfide (H2S) is an essential biological signaling molecule in diverse biological regulatory pathways. To provide new chemical tools for H2S imaging, we report here a fluorescent H2S detection platform (HSN2-BG) that is compatible with subcellular localization SNAP-tag fusion protein methodologies and use appropriate fusion protein constructs to demonstrate mitochondrial and lysosomal localization. We also demonstrate the efficacy of this detection platform to image endogenous H2S in Chinese hamster ovary (CHO) cells and use the developed constructs to report on the subcellular H2S distributions provided by common H2S donor molecules AP39, ADT-OH, GYY4137, and diallyltrisulfide (DATS). The developed constructs provide a platform poised to provide new insights into the subcellular distribution of common H2S donors and a useful tool for investigating H2S biochemistry.

  6. H2S regulation of nitric oxide metabolism

    PubMed Central

    Kolluru, Gopi K.; Yuan, Shuai; Shen, Xinggui; Kevil, Christopher G.

    2015-01-01

    Nitric oxide (NO) and hydrogen sulfide (H2S) are two major gaseous signaling molecules that regulate diverse physiological functions. Recent publications indicate the regulatory role of H2S on NO metabolism. In this chapter, we discuss the latest findings on H2S-NO interactions through formation of novel chemical derivatives, and experimental approaches to study these adducts. This chapter also addresses potential H2S interference on various NO detection techniques, along with precautions for analyzing biological samples from various sources. This information will facilitate critical evaluation and clearer insight into H2S regulation of NO signaling and its influence on various physiological functions. PMID:25725527

  7. Design of a 10**36 CM-2 S-1 Super-B Factory

    SciTech Connect

    Biagini, M.E.; Boni, R.; Boscolo, M.; Demma, T.; Drago, A.; Guiducci, S.; Raimondi, P.; Tomassini, S.; Zobov, M.; Bertsche, Kirk J.; Novokhatski, A.; Seeman, J.; Sullivan, M.; Wienands, U.; Wittmer, W.; Bettoni, S.; Paoloni, E.; Marchiori, G.; Bogomyagkov, A.; Koop, I.; Levichev, E.; /Novosibirsk, IYF

    2011-10-24

    Parameters have been studied for a high luminosity e{sup +}e{sup -} collider operating at the Upsilon 4S that would deliver a luminosity of 1 to 4 x 10{sup 36}/cm{sup 2}/s. This collider, called a Super-B Factory, would use a combination of linear collider and storage ring techniques. In this scheme an electron beam and a positron beam are stored in low-emittance damping rings similar to those designed for a Linear Collider (LC) or the next generation light source. A LC style interaction region is included in the ring to produce sub-millimeter vertical beta functions at the collision point. A large crossing angle (+/- 24 mrad) is used at the collision point to allow beam separation. A crab-waist scheme is used to reduce the hourglass effect and restore peak luminosity. Beam currents of 1.8 A at 4 x 7 GeV in 1251 bunches can produce a luminosity of 10{sup 36}/cm{sup 2}/s with upgrade possibilities. Such a collider would produce an integrated luminosity of about 10,000 fb{sup -1} (10 ab{sup -1}) in a running year (10{sup 7} sec) at the {gamma}(4S) resonance. Further possibilities include having longitudinally polarized e- at the IR and operating at the J/Psi and Psi beam energies.

  8. D3R grand challenge 2015: Evaluation of protein-ligand pose and affinity predictions

    NASA Astrophysics Data System (ADS)

    Gathiaka, Symon; Liu, Shuai; Chiu, Michael; Yang, Huanwang; Stuckey, Jeanne A.; Kang, You Na; Delproposto, Jim; Kubish, Ginger; Dunbar, James B.; Carlson, Heather A.; Burley, Stephen K.; Walters, W. Patrick; Amaro, Rommie E.; Feher, Victoria A.; Gilson, Michael K.

    2016-09-01

    The Drug Design Data Resource (D3R) ran Grand Challenge 2015 between September 2015 and February 2016. Two targets served as the framework to test community docking and scoring methods: (1) HSP90, donated by AbbVie and the Community Structure Activity Resource (CSAR), and (2) MAP4K4, donated by Genentech. The challenges for both target datasets were conducted in two stages, with the first stage testing pose predictions and the capacity to rank compounds by affinity with minimal structural data; and the second stage testing methods for ranking compounds with knowledge of at least a subset of the ligand-protein poses. An additional sub-challenge provided small groups of chemically similar HSP90 compounds amenable to alchemical calculations of relative binding free energy. Unlike previous blinded Challenges, we did not provide cognate receptors or receptors prepared with hydrogens and likewise did not require a specified crystal structure to be used for pose or affinity prediction in Stage 1. Given the freedom to select from over 200 crystal structures of HSP90 in the PDB, participants employed workflows that tested not only core docking and scoring technologies, but also methods for addressing water-mediated ligand-protein interactions, binding pocket flexibility, and the optimal selection of protein structures for use in docking calculations. Nearly 40 participating groups submitted over 350 prediction sets for Grand Challenge 2015. This overview describes the datasets and the organization of the challenge components, summarizes the results across all submitted predictions, and considers broad conclusions that may be drawn from this collaborative community endeavor.

  9. Outcome of the first wwPDB/CCDC/D3R Ligand Validation Workshop

    PubMed Central

    Adams, Paul D.; Aertgeerts, Kathleen; Bauer, Cary; Bell, Jeffrey A.; Berman, Helen M.; Bhat, Talapady N.; Blaney, Jeff; Bolton, Evan; Bricogne, Gerard; Brown, David; Burley, Stephen K.; Case, David A.; Clark, Kirk L.; Darden, Tom; Emsley, Paul; Feher, Victoria A.; Feng, Zukang; Groom, Colin R.; Harris, Seth F.; Hendle, Jorg; Holder, Thomas; Joachimiak, Andrzej; Kleywegt, Gerard J.; Krojer, Tobias; Marcotrigiano, Joseph; Mark, Alan E.; Markley, John L.; Miller, Matthew; Minor, Wladek; Montelione, Gaetano T.; Murshudov, Garib; Nakagawa, Atsushi; Nakamura, Haruki; Nicholls, Anthony; Nicklaus, Marc; Nolte, Robert T.; Padyana, Anil K.; Peishoff, Catherine E.; Pieniazek, Susan; Read, Randy J.; Shao, Chenghua; Sheriff, Steven; Smart, Oliver; Soisson, Stephen; Spurlino, John; Stouch, Terry; Svobodova, Radka; Tempel, Wolfram; Terwilliger, Thomas C.; Tronrud, Dale; Velankar, Sameer; Ward, Suzanna; Warren, Gregory L.; Westbrook, John D.; Williams, Pamela; Yang, Huanwang; Young, Jasmine

    2016-01-01

    Summary Crystallographic studies of ligands bound to biological macromolecules (proteins and nucleic acids) represent an important source of information concerning drug-target interactions, providing atomic level insights into the physical chemistry of complex formation between macromolecules and ligands. Of the more than 115,000 entries extant in the Protein Data Bank archive, ~75% include at least one non-polymeric ligand. Ligand geometrical and stereochemical quality, the suitability of ligand models for in silico drug discovery/design, and the goodness-of-fit of ligand models to electron density maps vary widely across the archive. We describe the proceedings and conclusions from the first Worldwide Protein Data Bank/Cambridge Crystallographic Data Centre/Drug Design Data Resource (wwPDB/CCDC/D3R) Ligand Validation Workshop held at the Research Collaboratory for Structural Bioinformatics at Rutgers University on July 30–31, 2015. Experts in protein crystallography from academe and industry came together with non-profit and for-profit software providers for crystallography and with experts in computational chemistry and data archiving to discuss and make recommendations on best practices, as framed by a series of questions central to structural studies of macromolecule-ligand complexes. What data concerning bound ligands should be archived in the Protein Data Bank? How should the ligands be best represented? How should structural models of macromolecule-ligand complexes be validated? What supplementary information should accompany publications of structural studies of biological macromolecules? Consensus recommendations on best practices developed in response to each of these questions are provided, together with some details regarding implementation. Important issues addressed but not resolved at the workshop are also enumerated. PMID:27050687

  10. Outcome of the First wwPDB/CCDC/D3R Ligand Validation Workshop

    DOE PAGES

    Adams, Paul  D.; Aertgeerts, Kathleen; Bauer, Cary; ...

    2016-04-05

    Crystallographic studies of ligands bound to biological macromolecules (proteins and nucleic acids) represent an important source of information concerning drug-target interactions, providing atomic level insights into the physical chemistry of complex formation between macromolecules and ligands. Of the more than 115,000 entries extant in the Protein Data Bank archive, ~75% include at least one non-polymeric ligand. Ligand geometrical and stereochemical quality, the suitability of ligand models for in silico drug discovery/design, and the goodness-of-fit of ligand models to electron density maps vary widely across the archive. We describe the proceedings and conclusions from the first Worldwide Protein Data Bank/Cambridge Crystallographicmore » Data Centre/Drug Design Data Resource (wwPDB/CCDC/D3R) Ligand Validation Workshop held at the Research Collaboratory for Structural Bioinformatics at Rutgers University on July 30-31, 2015. Experts in protein crystallography from academe and industry came together with non-profit and for-profit software providers for crystallography and with experts in computational chemistry and data archiving to discuss and make recommendations on best practices, as framed by a series of questions central to structural studies of macromolecule-ligand complexes. What data concerning bound ligands should be archived in the Protein Data Bank? How should the ligands be best represented? How should structural models of macromolecule-ligand complexes be validated? What supplementary information should accompany publications of structural studies of biological macromolecules? Consensus recommendations on best practices developed in response to each of these questions are provided, together with some details regarding implementation. Important issues addressed but not resolved at the workshop are also enumerated.« less

  11. Outcome of the First wwPDB/CCDC/D3R Ligand Validation Workshop

    SciTech Connect

    Adams, Paul  D.; Aertgeerts, Kathleen; Bauer, Cary; Bell, Jeffrey A.; Berman, Helen  M.; Bhat, Talapady  N.; Blaney, Jeff  M.; Bolton, Evan; Bricogne, Gerard; Brown, David; Burley, Stephen  K.; Case, David  A.; Clark, Kirk  L.; Darden, Tom; Emsley, Paul; Feher, Victoria  A.; Feng, Zukang; Groom, Colin  R.; Harris, Seth  F.; Hendle, Jorg; Holder, Thomas; Joachimiak, Andrzej; Kleywegt, Gerard  J.; Krojer, Tobias; Marcotrigiano, Joseph; Mark, Alan  E.; Markley, John  L.; Miller, Matthew; Minor, Wladek; Montelione, Gaetano  T.; Murshudov, Garib; Nakagawa, Atsushi; Nakamura, Haruki; Nicholls, Anthony; Nicklaus, Marc; Nolte, Robert  T.; Padyana, Anil  K.; Peishoff, Catherine E.; Pieniazek, Susan; Read, Randy  J.; Shao, Chenghua; Sheriff, Steven; Smart, Oliver; Soisson, Stephen; Spurlino, John; Stouch, Terry; Svobodova, Radka; Tempel, Wolfram; Terwilliger, Thomas  C.; Tronrud, Dale; Velankar, Sameer; Ward, Suzanna  C.; Warren, Gregory  L.; Westbrook, John  D.; Williams, Pamela; Yang, Huanwang; Young, Jasmine

    2016-04-05

    Crystallographic studies of ligands bound to biological macromolecules (proteins and nucleic acids) represent an important source of information concerning drug-target interactions, providing atomic level insights into the physical chemistry of complex formation between macromolecules and ligands. Of the more than 115,000 entries extant in the Protein Data Bank archive, ~75% include at least one non-polymeric ligand. Ligand geometrical and stereochemical quality, the suitability of ligand models for in silico drug discovery/design, and the goodness-of-fit of ligand models to electron density maps vary widely across the archive. We describe the proceedings and conclusions from the first Worldwide Protein Data Bank/Cambridge Crystallographic Data Centre/Drug Design Data Resource (wwPDB/CCDC/D3R) Ligand Validation Workshop held at the Research Collaboratory for Structural Bioinformatics at Rutgers University on July 30-31, 2015. Experts in protein crystallography from academe and industry came together with non-profit and for-profit software providers for crystallography and with experts in computational chemistry and data archiving to discuss and make recommendations on best practices, as framed by a series of questions central to structural studies of macromolecule-ligand complexes. What data concerning bound ligands should be archived in the Protein Data Bank? How should the ligands be best represented? How should structural models of macromolecule-ligand complexes be validated? What supplementary information should accompany publications of structural studies of biological macromolecules? Consensus recommendations on best practices developed in response to each of these questions are provided, together with some details regarding implementation. Important issues addressed but not resolved at the workshop are also enumerated.

  12. Identification of H2S3 and H2S produced by 3-mercaptopyruvate sulfurtransferase in the brain.

    PubMed

    Kimura, Yuka; Toyofuku, Yukiko; Koike, Shin; Shibuya, Norihiro; Nagahara, Noriyuki; Lefer, David; Ogasawara, Yuki; Kimura, Hideo

    2015-10-06

    Hydrogen polysulfides (H2Sn) have a higher number of sulfane sulfur atoms than hydrogen sulfide (H2S), which has various physiological roles. We recently found H2Sn in the brain. H2Sn induced some responses previously attributed to H2S but with much greater potency than H2S. However, the number of sulfur atoms in H2Sn and its producing enzyme were unknown. Here, we detected H2S3 and H2S, which were produced from 3-mercaptopyruvate (3 MP) by 3-mercaptopyruvate sulfurtransferase (3MST), in the brain. High performance liquid chromatography with fluorescence detection (LC-FL) and tandem mass spectrometry (LC-MS/MS) analyses showed that H2S3 and H2S were produced from 3 MP in the brain cells of wild-type mice but not 3MST knockout (3MST-KO) mice. Purified recombinant 3MST and lysates of COS cells expressing 3MST produced H2S3 from 3 MP, while those expressing defective 3MST mutants did not. H2S3 was localized in the cytosol of cells. H2S3 was also produced from H2S by 3MST and rhodanese. H2S2 was identified as a minor H2Sn, and 3 MP did not affect the H2S5 level. The present study provides new insights into the physiology of H2S3 and H2S, as well as novel therapeutic targets for diseases in which these molecules are involved.

  13. First-principles investigation of R{sub 2}O{sub 3}(ZnO){sub 3} (R=Al, Ga, and In) in homologous series of compounds

    SciTech Connect

    Yoshioka, Satoru Toyoura, Kazuaki; Oba, Fumiyasu; Kuwabara, Akihide; Matsunaga, Katsuyuki; Tanaka, Isao

    2008-01-15

    Atomic and electronic structures of R{sub 2}O{sub 3}(ZnO){sub 3} (R=Al, Ga, and In), which are included in homologous series of compounds, are investigated using first-principles calculations based on density functional theory. Three models with different R atom arrangements in the five-fold and four-fold coordination sites are examined. Al and Ga prefer the five-fold coordination sites. The formation energies are much larger than those of the competing phases, ZnR{sub 2}O{sub 4}, with a normal spinel structure. On the other hand, In{sub 2}O{sub 3}(ZnO){sub 3} shows no clear site preference and can be more stable than the spinel at high temperatures when configurational entropy contribution is taken into account. Electronic states near the conduction band bottom are mainly composed of Zn-4s orbital in Al{sub 2}O{sub 3}(ZnO){sub 3}, while the contributions of Ga-4s and In-5s are comparable to Zn-4s in Ga{sub 2}O{sub 3}(ZnO){sub 3} and In{sub 2}O{sub 3}(ZnO){sub 3}. - Graphical abstract: R{sub 2}O{sub 3}(ZnO){sub 3} (R=Al, Ga, and In) in homologous series of compounds are investigated using first-principles calculations with special interest on preferred occupation sites of R, relative energetics with competing phases and electronic structures.

  14. Hydrogen polysulfide (H2S n ) signaling along with hydrogen sulfide (H2S) and nitric oxide (NO).

    PubMed

    Kimura, Hideo

    2016-11-01

    Hydrogen sulfide (H2S) is a physiological mediator with various roles, including neuro-modulation, vascular tone regulation, and cytoprotection against ischemia-reperfusion injury, angiogenesis, and oxygen sensing. Hydrogen polysulfide (H2S n ), which possesses a higher number of sulfur atoms than H2S, recently emerged as a potential signaling molecule that regulates the activity of ion channels, a tumor suppressor, transcription factors, and protein kinases. Some of the previously reported effects of H2S are now attributed to the more potent H2S n . H2S n is produced by 3-mercaptopyruvate sulfurtransferase (3MST) from 3-mercaptopyruvate (3MP) and is generated by the chemical interaction of H2S with nitric oxide (NO). H2S n sulfhydrates (sulfurates) cysteine residues of target proteins and modifies their activity, whereas H2S sulfurates oxidized cysteine residues as well as reduces cysteine disulfide bonds. This review focuses on the recent progress made in studies concerning the production and physiological roles of H2S n and H2S.

  15. Working with "H2S": facts and apparent artifacts.

    PubMed

    Wedmann, Rudolf; Bertlein, Sarah; Macinkovic, Igor; Böltz, Sebastian; Miljkovic, Jan Lj; Muñoz, Luis E; Herrmann, Martin; Filipovic, Milos R

    2014-09-15

    Hydrogen sulfide (H2S) is an important signaling molecule with physiological endpoints similar to those of nitric oxide (NO). Growing interest in its physiological roles and pharmacological potential has led to large sets of contradictory data. The principle cause of these discrepancies can be the common neglect of some of the basic H2S chemistry. This study investigates how the experimental outcome when working with H2S depends on its source and dose and the methodology employed. We show that commercially available NaHS should be avoided and that traces of metal ions should be removed because these can reduce intramolecular disulfides and change protein structure. Furthermore, high H2S concentrations may lead to a complete inhibition of cell respiration, mitochondrial membrane potential depolarization and superoxide generation, which should be considered when discussing the biological effects observed upon treatment with high concentrations of H2S. In addition, we provide chemical evidence that H2S can directly react with superoxide. H2S is also capable of reducing cytochrome c(3+) with the concomitant formation of superoxide. H2S does not directly react with nitrite but with NO electrodes that detect H2S. In addition, H2S interferes with the Griess reaction and should therefore be removed from the solution by Cd(2+) or Zn(2+) precipitation prior to nitrite quantification. 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) is reduced by H2S, and its use should be avoided in combination with H2S. All these constraints must be taken into account when working with H2S to ensure valid data.

  16. A PAS domain with an oxygen labile [4Fe-4S](2+) cluster in the oxygen sensor kinase NreB of Staphylococcus carnosus.

    PubMed

    Müllner, Martin; Hammel, Oliver; Mienert, Bernd; Schlag, Steffen; Bill, Eckhard; Unden, Gottfried

    2008-12-30

    The cytoplasmic histidine sensor kinase NreB of Staphylococcus carnosus responds to O(2) and controls together with the response regulator NreC the expression of genes of nitrate/nitrite respiration. nreBC homologous genes were found in Staphylococcus strains and Bacillus clausii, and a modified form was found in some Lactobacillus strains. NreB contains a sensory domain with similarity to heme B binding PAS domains. Anaerobically prepared NreB of S. carnosus exhibited a (diamagnetic) [4Fe-4S](2+) cluster when assessed by Mossbauer spectroscopy. Upon reaction with air, the cluster was degraded with a half-life of approximately 2.5 min. No significant amounts of Mossbauer or EPR detectable intermediates were found during the decay, but magnetic Mossbauer spectra revealed formation of diamagnetic [2Fe-2S](2+) clusters. After extended exposure to air, NreB was devoid of a FeS cluster. Photoreduction with deazaflavin produced small amounts of [4Fe-4S](+), which were degraded subsequently. The magnetically perturbed Mossbauer spectrum of the [4Fe-4S](2+) cluster corroborated the S = 0 spin state and revealed uniform electric field gradient tensors of the iron sites, suggesting full delocalization of the valence electrons and binding of each of the Fe ions by four S ligands, including the ligand to the protein. Mutation of each of the four Cys residues inactivated NreB function in vivo in accordance with their role as ligands. [4Fe-4S](2+) cluster-containing NreB had high kinase activity. Exposure to air decreased the kinase activity and content of the [4Fe-4S](2+) cluster with similar half-lives. We conclude that the sensory domain of NreB represents a new type of PAS domain containing a [4Fe-4S](2+) cluster for sensing and function.

  17. Synthesis and Functions of Ag2S Nanostructures

    NASA Astrophysics Data System (ADS)

    Cui, Chunyan; Li, Xiaoru; Liu, Jixian; Hou, Yongchao; Zhao, Yuqing; Zhong, Guocheng

    2015-11-01

    The paper presents a review about synthesis and applications of Ag2S nanostructures. As the modern photoelectric and biological materials, Ag2S nanomaterials are potentially useful for both structure and function purposes. Ag2S is a direction narrow band gap semiconductor with special properties. Ag2S nanostructures have been widely researched in chemistry and biochemistry fields because of their unusual optical, electrical, and mechanical properties. It can also be used in many fields, such as photovoltaic cells and infrared detector. In the past few years, Ag2S nanostructures have been synthesized by various methods. The article mainly discusses the four types of preparation methods. Moreover, this article shows a detailed review on the new properties, fabrication, and applications of Ag2S nanocrystals.

  18. A Redox Active [2Fe-2S] Cluster on the Hydrogenase Maturase HydF.

    PubMed

    Shepard, Eric M; Byer, Amanda S; Betz, Jeremiah N; Peters, John W; Broderick, Joan B

    2016-06-28

    [FeFe]-hydrogenases are nature's most prolific hydrogen catalysts, excelling at facilely interconverting H2 and protons. The catalytic core common to all [FeFe]-hydrogenases is a complex metallocofactor, referred to as the H-cluster, which is composed of a standard [4Fe-4S] cluster linked through a bridging thiolate to a 2Fe subcluster harboring dithiomethylamine, carbon monoxide, and cyanide ligands. This 2Fe subcluster is synthesized and inserted into [FeFe]-hydrogenase by three maturase enzymes denoted HydE, HydF, and HydG. HydE and HydG are radical S-adenosylmethionine enzymes and synthesize the nonprotein ligands of the H-cluster. HydF is a GTPase that functions as a scaffold or carrier for 2Fe subcluster production. Herein, we utilize UV-visible, circular dichroism, and electron paramagnetic resonance spectroscopic studies to establish the existence of redox active [4Fe-4S] and [2Fe-2S] clusters bound to HydF. We have used spectroelectrochemical titrations to assign iron-sulfur cluster midpoint potentials, have shown that HydF purifies with a reduced [2Fe-2S] cluster in the absence of exogenous reducing agents, and have tracked iron-sulfur cluster spectroscopic changes with quaternary structural perturbations. Our results provide an important foundation for understanding the maturation process by defining the iron-sulfur cluster content of HydF prior to its interaction with HydE and HydG. We speculate that the [2Fe-2S] cluster of HydF either acts as a placeholder for HydG-derived Fe(CO)2CN species or serves as a scaffold for 2Fe subcluster assembly.

  19. Asymmetric aza-[2,3]-Wittig sigmatropic rearrangements: chiral auxiliary control and formal asymmetric synthesis of (2S, 3R, 4R)-4-hydroxy-3-methylproline and (-)-kainic acid.

    PubMed

    Anderson, James C; O'Loughlin, Julian M A; Tornos, James A

    2005-08-07

    A survey of 16 different chiral auxiliaries and a variety of strategies found that an (-)-8-phenylmenthol ester of a glycine derived migrating group can control the absolute stereochemistry of aza-[2,3]-Wittig sigmatropic rearrangements with diastereoselectivities of ca. 3 : 1 with respect to the auxiliary. In two specific examples, ca. 50% yields of enantiomerically pure products were obtained after chromatographic purification. These were synthetically manipulated with no erosion of stereochemistry into intermediates that completed formal asymmetric syntheses of (+)-HyMePro and (-)-kainic acid.

  20. Observations of the H2S toward OMC-1

    NASA Technical Reports Server (NTRS)

    Minh, Y. C.; Irvine, W. M.; Mcgonagle, D.; Ziurys, L. M.

    1990-01-01

    Observations of the 1(10) - 1(01) transition of interstellar H2S and its isotopes toward OMC-1 are reported. The fractional abundance of H2S in the quiescent regions of OMC-1 seems difficult to explain by currently known ion-molecular reactions. The fractional abundance of H2S relative to H2 is enhanced by a factor of 1000 in the hot core and the plateau relative to the quiescent clouds. The (HDS)/(H2S) abundance ratio in the hot core is estimated at 0.02 or less.

  1. H2S and Blood Vessels: An Overview.

    PubMed

    Yang, Guangdong; Wang, Rui

    2015-01-01

    The physiological and biomedical importance of hydrogen sulfide (H2S) has been fully recognized in the cardiovascular system as well as in the rest of the body. In blood vessels, cystathionine γ-lyase (CSE) is a major H2S-producing enzyme expressed in both smooth muscle and endothelium as well as periadventitial adipose tissues. Regulation of H2S production from CSE is controlled by a complex integration of transcriptional, posttranscriptional, and posttranslational mechanisms in blood vessels. In smooth muscle cells, H2S regulates cell apoptosis, phenotypic switch, relaxation and contraction, and calcification. In endothelial cells, H2S controls cell proliferation, cellular senescence, oxidative stress, inflammation, etc. H2S interacts with nitric oxide and acts as an endothelium-derived relaxing factor and an endothelium-derived hyperpolarizing factor. H2S generated from periadventitial adipose tissues acts as an adipocyte-derived relaxing factor and modulates the vascular tone. Extensive evidence has demonstrated the beneficial roles of the CSE/H2S system in various blood vessel diseases, such as hypertension, atherosclerosis, and aortic aneurysm. The important roles signaling in the cardiovascular system merit further intensive and extensive investigation. H2S-releasing agents and CSE activators will find their great applications in the prevention and treatment of blood vessel-related disorders.

  2. H2S: a novel gasotransmitter that signals by sulfhydration

    PubMed Central

    Paul, Bindu D.; Snyder, Solomon H.

    2015-01-01

    Hydrogen sulfide is a member of the growing family of gasotransmitters. Once regarded as a noxious molecule predominantly present in the atmosphere, H2S is now known to be synthesized endogenously in mammals. H2S participates in a myriad of physiological processes ranging from regulation of blood pressure to neuroprotection. Its chemical nature precludes H2S from being stored in vesicles and acting on receptor proteins in the fashion of other chemical messengers. Thus, novel cellular mechanisms have evolved to mediate its effects. This article focuses on sulfhydration (or persulfidation), which appears to be the principal post-translational modification elicited by H2S. PMID:26439534

  3. Fabrication of LiNbO3-As2S3 waveguides for beam steering applications

    NASA Astrophysics Data System (ADS)

    Macik, Dwayne D.; Madsen, Christi K.

    2016-09-01

    A hybrid annealed proton exchange (APE) waveguide with a vertically integrated arsenic trisulfide (As2S3) waveguide on a lithium niobate (LiNbO3) substrate is used to create an optical phased array (OPA) that allows for the non-mechanical steering of 1550 nm light on an integrated optic platform. The high electro-optic coefficient of the x-cut y-propagating LiNbO3 (r33 = 30.8 pm/V) is utilized by electrode structures fabricated on the LiNbO3 substrate to create a low-power, lowloss beam steering with high-speed bandwidths, capable of 10 GHz and larger as demonstrated by commercial LiNbO3 modulators. The As2S3 waveguide is introduced because of its high refractive index, which leads to a highly confined optical mode. Design and fabrication are presented for a large full width steering angle of 34°, representing an order of magnitude improvement over low-confinement, diffused LiNbO3 waveguides and two orders of magnitude improvement over other reported LiNbO3 OPAs.

  4. (2R,1'S,2'R)- and (2S,1'S,2'R)-3-[2-Mono(di,tri)fluoromethylcyclopropyl]alanines and their incorporation into hormaomycin analogues

    PubMed Central

    Kozhushkov, Sergei I; Yufit, Dmitrii S; Grosse, Christian; Kaiser, Marcel

    2014-01-01

    Summary Efficient and scalable syntheses of enantiomerically pure (2R,1'S,2'R)- and (2S,1'S,2'R)-3-[2-mono(di,tri)fluoromethylcyclopropyl]alanines 9a–c, as well as allo-D-threonine (4) and (2S,3R)-β-methylphenylalanine (3), using the Belokon' approach with (S)- and (R)-2-[(N-benzylprolyl)amino]benzophenone [(S)- and (R)-10] as reusable chiral auxiliaries have been developed. Three new fluoromethyl analogues of the naturally occurring octadepsipeptide hormaomycin (1) with (fluoromethylcyclopropyl)alanine moieties have been synthesized and subjected to preliminary tests of their antibiotic activity. PMID:25550751

  5. Hydrazine solution processed Sb2S3, Sb2Se3 and Sb2(S1−xSex)3 film: molecular precursor identification, film fabrication and band gap tuning

    PubMed Central

    Yang, Bo; Xue, Ding-Jiang; Leng, Meiying; Zhong, Jie; Wang, Liang; Song, Huaibing; Zhou, Ying; Tang, Jiang

    2015-01-01

    Sb2(S1−xSex)3 (0 ≤ x ≤ 1) compounds have been proposed as promising light-absorbing materials for photovoltaic device applications. However, no systematic study on the synthesis and characterization of polycrystalline Sb2(S1−xSex)3 thin films has been reported. Here, using a hydrazine based solution process, single-phase Sb2(S1−xSex)3 films were successfully obtained. Through Raman spectroscopy, we have investigated the dissolution mechanism of Sb in hydrazine: 1) the reaction between Sb and S/Se yields [Sb4S7]2-/[Sb4Se7]2- ions within their respective solutions; 2) in the Sb-S-Se precursor solutions, Sb, S, and Se were mixed on a molecular level, facilitating the formation of highly uniform polycrystalline Sb2(S1−xSex)3 thin films at a relatively low temperature. UV-vis-NIR transmission spectroscopy revealed that the band gap of Sb2(S1−xSex)3 alloy films had a quadratical relationship with the Se concentration x and it followed the equation , where the bowing parameter was 0.118 eV. Our study provides a valuable guidance for the adjustment and optimization of the band gap in hydrazine solution processed Sb2(S1−xSex)3 alloy films for the future fabrication of improved photovoltaic devices. PMID:26042519

  6. Hydrazine solution processed Sb2S3, Sb2Se3 and Sb2(S1-xSex)3 film: molecular precursor identification, film fabrication and band gap tuning

    NASA Astrophysics Data System (ADS)

    Yang, Bo; Xue, Ding-Jiang; Leng, Meiying; Zhong, Jie; Wang, Liang; Song, Huaibing; Zhou, Ying; Tang, Jiang

    2015-06-01

    Sb2(S1-xSex)3 (0 ≤ x ≤ 1) compounds have been proposed as promising light-absorbing materials for photovoltaic device applications. However, no systematic study on the synthesis and characterization of polycrystalline Sb2(S1-xSex)3 thin films has been reported. Here, using a hydrazine based solution process, single-phase Sb2(S1-xSex)3 films were successfully obtained. Through Raman spectroscopy, we have investigated the dissolution mechanism of Sb in hydrazine: 1) the reaction between Sb and S/Se yields [Sb4S7]2-/[Sb4Se7]2- ions within their respective solutions; 2) in the Sb-S-Se precursor solutions, Sb, S, and Se were mixed on a molecular level, facilitating the formation of highly uniform polycrystalline Sb2(S1-xSex)3 thin films at a relatively low temperature. UV-vis-NIR transmission spectroscopy revealed that the band gap of Sb2(S1-xSex)3 alloy films had a quadratical relationship with the Se concentration x and it followed the equation , where the bowing parameter was 0.118 eV. Our study provides a valuable guidance for the adjustment and optimization of the band gap in hydrazine solution processed Sb2(S1-xSex)3 alloy films for the future fabrication of improved photovoltaic devices.

  7. The Effects of Keyword Cues and 3R Strategy on Children's e-Book Reading

    ERIC Educational Resources Information Center

    Liang, T.-H.

    2015-01-01

    Various studies have found that electronic books (e-books) promote learning, but few works have examined the use of e-books along with an adaptive reading strategy for children. The current study implemented a method to extract keyword cues from e-books to support e-book reading with the read, recite and review (3R) strategy, and then examined the…

  8. ACTN3 R577X polymorphism does not influence explosive leg muscle power in elite volleyball players.

    PubMed

    Ruiz, J R; Fernández del Valle, M; Verde, Z; Díez-Vega, I; Santiago, C; Yvert, T; Rodríguez-Romo, G; Gómez-Gallego, F; Molina, J J; Lucia, A

    2011-12-01

    We examined the association of R577X polymorphism (rs1815739) in the α-actinin-3 (ACTN3) gene with "explosive" leg muscle power performance in a group of male and female elite volleyball players (n=66, 31 men, 35 women) and in a group of non-athletic male and female young adults (n=334, 243 men, 91 women). We assessed power performance by means of the vertical squat and counter-movement jump tests. We also determined whether the genotypic frequencies of the ACTN3 R577X genotypes differed between groups. We did not observe any effect of the ACTN3 R577X polymorphism on study phenotypes in both groups, regardless of gender (all P>0.05). Genotype frequencies were similar between volleyball and control groups (P=0.095). Moreover, we did not find an association between the ACTN3 R577X polymorphism and the likelihood of being an elite volleyball player using the dominant (RR vs RX+XX) and the recessive model (RR+RX vs XX). In summary, these findings suggest that the ACTN3 R577X polymorphism does not influence explosive leg muscle power in elite volleyball players.

  9. Solid waste management in Asian countries: a review of solid waste minimisation (3'r) towards low carbon

    NASA Astrophysics Data System (ADS)

    Ali, N. E.; Sion, H. C.

    2014-02-01

    The amount of solid-waste generated in Asian countries has increased tremendously, mainly due to the improvement in living standards, rapid developments in technology, growth in economy and population in the cities. Solid waste management is a global issue and major challenge facing Asian countries and neglecting its management may have negative consequences on the environment. Waste composition data proves the developed countries to have generated more recyclable materials while developing countries produce more organic and less recyclable waste such as paper, plastic and aluminium. In this regard, increase in number of landfills and disposal sites, will have an impact on GHG (greenhouse gas) emissions and pollutants to air and water. Alternative methods should therefore be taken to reduce the volume of waste. Most Asian countries have adopted the 3R (reduce, reuse, recycle) concept in order to reduce solid waste and their governments have implemented laws and regulations in order to support this. Implementation of 3R is the major contributor to the solid waste minimization and it can improve the quality of environmental sustainability and reduction of carbon dioxide emission in to the atmosphere. Based on our review, most of the countries practicing the 3R concept in tandem with laws and regulations perform better than those that just practice the 3R concept without any laws and regulations. The paper suggests that every country must focus on the laws and regulations relating to solid waste minimization so that it could be easily implemented as outlined.

  10. A Multifunctional and Possible Skin UV Protectant, (3R)-5-Hydroxymellein, Produced by an Endolichenic Fungus Isolated from Parmotrema austrosinense.

    PubMed

    Zhao, Lu; Kim, Jin-Cheol; Paik, Man-Jeong; Lee, Wonjae; Hur, Jae-Seoun

    2016-12-26

    Lichens are considered a great bio-resource because they produce large numbers of secondary metabolites with many biological activities; however, they have not been cultivated under artificial conditions to date. As a result, lichen substances from natural sources are limited and have not been widely utilized in commercial applications. Accordingly, interest in lichen-associated fungi, especially endogenic fungi, has increased. Ultraviolet (UV) radiation in sunlight is harmful to human health, resulting in demand for effective UV filtering agents for use in sunscreen. In this study, we purified (3R)-5-hydroxymellein, which has UVA absorption activity, from the secondary metabolites of an endolichenic fungus (ELF000039). The antioxidant properties were then assessed by in vitro tests. The antioxidant activity of (3R)-5-hydroxymellein was high when compared to the recognized antioxidants ascorbic acid (ASA) and butyl hydroxyl anisole (BHA). Moreover, the compound exhibited no cytotoxicity toward mouse melanoma cell lines, B16F1 and B16F10, or the normal cell line, HaCaT. Furthermore, (3R)-5-hydroxymellein recovered the damage caused by UVB irradiation and inhibited melanin synthesis. Taken together, these results suggest that (3R)-5-hydroxymellein could have an interesting and vital profile to go further development as a multifunctional skin UV protectant.

  11. Synthesis of (3R)-acetoin and 2,3-butanediol isomers by metabolically engineered Lactococcus lactis

    PubMed Central

    Kandasamy, Vijayalakshmi; Liu, Jianming; Dantoft, Shruti Harnal; Solem, Christian; Jensen, Peter Ruhdal

    2016-01-01

    The potential that lies in harnessing the chemical synthesis capabilities inherent in living organisms is immense. Here we demonstrate how the biosynthetic machinery of Lactococcus lactis, can be diverted to make (3R)-acetoin and the derived 2,3-butanediol isomers meso-(2,3)-butanediol (m-BDO) and (2R,3R)-butanediol (R-BDO). Efficient production of (3R)-acetoin was accomplished using a strain where the competing lactate, acetate and ethanol forming pathways had been blocked. By introducing different alcohol dehydrogenases into this strain, either EcBDH from Enterobacter cloacae or SadB from Achromobacter xylosooxidans, it was possible to achieve high-yield production of m-BDO or R-BDO respectively. To achieve biosustainable production of these chemicals from dairy waste, we transformed the above strains with the lactose plasmid pLP712. This enabled efficient production of (3R)-acetoin, m-BDO and R-BDO from processed whey waste, with titers of 27, 51, and 32 g/L respectively. The corresponding yields obtained were 0.42, 0.47 and 0.40 g/g lactose, which is 82%, 89%, and 76% of maximum theoretical yield respectively. These results clearly demonstrate that L. lactis is an excellent choice as a cell factory for transforming lactose containing dairy waste into value added chemicals. PMID:27857195

  12. Synthesis of (3R)-acetoin and 2,3-butanediol isomers by metabolically engineered Lactococcus lactis.

    PubMed

    Kandasamy, Vijayalakshmi; Liu, Jianming; Dantoft, Shruti Harnal; Solem, Christian; Jensen, Peter Ruhdal

    2016-11-18

    The potential that lies in harnessing the chemical synthesis capabilities inherent in living organisms is immense. Here we demonstrate how the biosynthetic machinery of Lactococcus lactis, can be diverted to make (3R)-acetoin and the derived 2,3-butanediol isomers meso-(2,3)-butanediol (m-BDO) and (2R,3R)-butanediol (R-BDO). Efficient production of (3R)-acetoin was accomplished using a strain where the competing lactate, acetate and ethanol forming pathways had been blocked. By introducing different alcohol dehydrogenases into this strain, either EcBDH from Enterobacter cloacae or SadB from Achromobacter xylosooxidans, it was possible to achieve high-yield production of m-BDO or R-BDO respectively. To achieve biosustainable production of these chemicals from dairy waste, we transformed the above strains with the lactose plasmid pLP712. This enabled efficient production of (3R)-acetoin, m-BDO and R-BDO from processed whey waste, with titers of 27, 51, and 32 g/L respectively. The corresponding yields obtained were 0.42, 0.47 and 0.40 g/g lactose, which is 82%, 89%, and 76% of maximum theoretical yield respectively. These results clearly demonstrate that L. lactis is an excellent choice as a cell factory for transforming lactose containing dairy waste into value added chemicals.

  13. IP3R deficit underlies loss of salivary fluid secretion in Sjögren’s Syndrome

    PubMed Central

    Teos, Leyla Y.; Zhang, Yu; Cotrim, Ana P.; Swaim, William; Won, Jon H.; Ambrus, Julian; Shen, Long; Bebris, Lolita; Grisius, Margaret; Jang, Shyh-Ing; Yule, David I.; Ambudkar, Indu S.; Alevizos, Ilias

    2015-01-01

    The autoimmune exocrinopathy, Sjögren’s syndrome (SS), is associated with secretory defects in patients, including individuals with mild lymphocytic infiltration and minimal glandular damage. The mechanism(s) underlying the secretory dysfunction is not known. We have used minor salivary gland biopsies from SS patients and healthy individuals to assess acinar cell function in morphologically intact glandular areas. We report that agonist-regulated intracellular Ca2+ release, critically required for Ca2+ entry and fluid secretion, is defective in acini from SS patients. Importantly, these acini displayed reduction in IP3R2 and IP3R3, but not AQP5 or STIM1. Similar decreases in IP3R and carbachol (CCh)-stimulated [Ca2+]i elevation were detected in acinar cells from lymphotoxin-alpha (LTα) transgenic (TG) mice, a model for (SS). Treatment of salivary glands from healthy individuals with LT α, a cytokine linked to disease progression in SS and IL14α mice, reduced Ca2+ signaling. Together, our findings reveal novel IP3R deficits in acinar cells that underlie secretory dysfunction in SS patients. PMID:26365984

  14. R3-R4 deletion in the PRNP gene is associated with Creutzfeldt-Jakob disease (CJD)

    SciTech Connect

    Cervenakova, L.; Brown, P.; Nagle, J.

    1994-09-01

    There are conflicting reports on the association of deletions in the PRNP gene on chromosome 20 with CJD, a rapidly progressive fatal spongiform encephalopathy. We accumulated data suggesting that a deletion of R3-R4 type (parts of the third and fourth repeats are deleted from the area of four repeating 24 bp sequences in the 5{prime} region of the gene) is causing CJD. Screening of 129 unaffected control individuals demonstrated presence of a deletion of R2 type in four (1.55% of the studied chromosomes), but none of them had the R3-R4 type. Of 181 screened patients with spongiform encephalopathies, two had a deletion of R3-R4 type with no other mutations in the coding sequence. Both patients had a classical rapidly progressive dementing disease and diffuse spongiform degeneration, and both cases were apparently sporadic. The same R3-R4 type of deletion was detected in three additional neuropathologically confirmed spongiform encephalopathy patients, of which two had other known pathogenic mutations in the PRNP gene: at codon 178 on the methionine allele exhibiting the phenotype of fatal familial insomnia, and codon 200 causing CJD with severe dementia; the third was a patient with iatrogenic CJD who developed the disease after treatment with growth hormone extracted from cadaveric human pituitary glands. In all cases the deletion coincided with a variant sequence at position 129 coding for methionine.

  15. Washout of tritium from 3R-3(/sup 3/H)-L-aspartate in the aspartase reaction

    SciTech Connect

    Katz, B.M.; Cook, P.F.

    1987-05-01

    Bacterial aspartase catalyzes the reversible conversion of L-aspartate to fumarate and ammonia. Recent studies that made use of deuterium and /sup 15/N isotope effects suggested a carbanion intermediate mechanism in which C-N bond cleavage is rate determining. This could result in removal of a proton from the 3R position of aspartate at a rate of faster than the elimination of ammonia. 3R-3(/sup 3/H)-Aspartate was prepared enzymatically using aspartase from fumarate, ammonia and /sup 3/H/sub 2/O and aspartate isolated via chromatography on Dowex 50W x 8 at pH 1, eluting with 2N pyridine. The rate of /sup 3/H washout from this aspartate was then measured as a function of aspartate concentration and compared to the rate of production of fumarate. Tritium does washout of aspartate at a rate faster than fumarate is formed but the proton is apparently not rapidly equilibrated with solvent. The tritium washout experiments were supplemented using 3R-3(/sup 2/H)-aspartate prepared as above with /sup 2/H/sub 2/O replacing /sup 3/H/sub 2/O and monitoring the appearance of 3R-3(/sup 1/H)-aspartate via /sup 1/H-NMR. Results confirm the tritium washout results. Data are discussed in terms of the carbanion mechanism.

  16. Observation of B±→ψ(2S)π± and search for direct CP violation

    NASA Astrophysics Data System (ADS)

    Bhardwaj, V.; Kumar, R.; Singh, J. B.; Adachi, I.; Aihara, H.; Arinstein, K.; Aushev, T.; Aziz, T.; Bahinipati, S.; Bakich, A. M.; Balagura, V.; Barberio, E.; Bay, A.; Belous, K.; Bitenc, U.; Bondar, A.; Bozek, A.; Bračko, M.; Brodzicka, J.; Browder, T. E.; Chang, M.-C.; Chang, P.; Chen, A.; Cheon, B. G.; Chistov, R.; Cho, I.-S.; Choi, S.-K.; Choi, Y.; Dalseno, J.; Dash, M.; Drutskoy, A.; Eidelman, S.; Goldenzweig, P.; Golob, B.; Ha, H.; Hara, T.; Hayasaka, K.; Hayashii, H.; Hazumi, M.; Hoshi, Y.; Hou, W.-S.; Hsiung, Y. B.; Hyun, H. J.; Iijima, T.; Inami, K.; Ishikawa, A.; Ishino, H.; Itoh, R.; Iwasaki, M.; Iwasaki, Y.; Joshi, N. J.; Kah, D. H.; Kang, J. H.; Katayama, N.; Kawai, H.; Kawasaki, T.; Kichimi, H.; Kim, H. O.; Kim, S. K.; Kim, Y. I.; Kim, Y. J.; Kinoshita, K.; Korpar, S.; Križan, P.; Krokovny, P.; Kuzmin, A.; Kwon, Y.-J.; Kyeong, S.-H.; Lange, J. S.; Lee, J. S.; Lin, S.-W.; Liu, C.; Liu, Y.; Liventsev, D.; Mandl, F.; Matyja, A.; McOnie, S.; Medvedeva, T.; Miyabayashi, K.; Miyata, H.; Miyazaki, Y.; Mizuk, R.; Moloney, G. R.; Nagasaka, Y.; Nakao, M.; Natkaniec, Z.; Nishida, S.; Nitoh, O.; Ogawa, S.; Ohshima, T.; Okuno, S.; Olsen, S. L.; Ozaki, H.; Pakhlov, P.; Pakhlova, G.; Park, C. W.; Park, H.; Park, H. K.; Peak, L. S.; Pestotnik, R.; Piilonen, L. E.; Sahoo, H.; Sakai, Y.; Schneider, O.; Schümann, J.; Schwanda, C.; Schwartz, A. J.; Senyo, K.; Sevior, M. E.; Shapkin, M.; Shen, C. P.; Shiu, J.-G.; Shwartz, B.; Somov, A.; Stanič, S.; Starič, M.; Sumiyoshi, T.; Suzuki, S.; Tamura, N.; Tanaka, M.; Taylor, G. N.; Teramoto, Y.; Trabelsi, K.; Uehara, S.; Uglov, T.; Unno, Y.; Uno, S.; Urquijo, P.; Varner, G.; Varvell, K. E.; Vervink, K.; Wang, C. C.; Wang, C. H.; Wang, M.-Z.; Wang, P.; Wang, X. L.; Watanabe, Y.; Won, E.; Yamashita, Y.; Yamauchi, M.; Zhang, C. C.; Zhulanov, V.; Zivko, T.; Zupanc, A.; Zyukova, O.

    2008-09-01

    We report the first observation of B±→ψ(2S)π±, a Cabibbo- and color-suppressed decay. This analysis is based on 657×106 B Bmacr events collected at the Υ(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. The measured branching fraction is (2.44±0.22±0.20)×10-5 and the charge asymmetry is A=0.022±0.085±0.016. The ratio of the branching fractions B(B±→ψ(2S)π±)/B(B±→ψ(2S)K±)=(3.99±0.36±0.17)% is also determined.

  17. CSF3R T618I is a highly prevalent and specific mutation in chronic neutrophilic leukemia

    PubMed Central

    Pardanani, A; Lasho, TL; Laborde, RR; Elliott, M; Hanson, CA; Knudson, RA; Ketterling, RP; Maxson, JE; Tyner, JW; Tefferi, A

    2014-01-01

    Truncation mutations of the receptor cytoplasmic domain for colony-stimulating factor 3 (CSF3R) are frequently seen in severe congenital neutropenia, whereas activating missense mutations affecting the extracellular domain (exon 14) have been described in hereditary neutrophilia and chronic neutrophilic leukemia (CNL). In order to clarify mutational frequency, specificity and phenotypic associations, we sequenced CSF3R exons 14–17 in 54 clinically suspected cases of CNL (n=35) or atypical chronic myeloid leukemia (aCML; n=19). Central review of these cases confirmed WHO-defined CNL in 12 patients, monoclonal gammopathy (MG)-associated CNL in 5 and WHO-defined aCML in 9. A total of 14 CSF3R mutations were detected in 13 patients, including 10 with CSF3RT618I (exon 14 mutation, sometimes annotated as CSF3R T595I). CSF3RT618I occurred exclusively in WHO-defined CNL with a mutational frequency of 83% (10 of 12 cases). CSF3R mutations were not seen in aCML or MG-associated CNL. CSF3RT618I was also absent among 170 patients with primary myelofibrosis (PMF; n=76) or chronic myelomonocytic leukemia (CMML; n=94). SETBP1 mutational frequencies in WHO-defined CNL, aCML, CMML and PMF were 33, 0, 7 and 3%, respectively. Four CSF3RT618I-mutated cases co-expressed SETBP1 mutations. We conclude that CSF3RT618I is a highly sensitive and specific molecular marker for CNL and should be incorporated into current diagnostic criteria. PMID:23604229

  18. Genetic Regulation of Development in Sorghum bicolor (IX. The ma3R Allele Disrupts Diurnal Control of Gibberellin Biosynthesis).

    PubMed Central

    Foster, K. R.; Morgan, P. W.

    1995-01-01

    The diurnal regulation of gibberellin (GA) concentrations in Sorghum bicolor was studied in a mutant lacking a light-stable 123-kD phytochrome (ma3Rma3R), wild-type (ma3ma3,Ma3Ma3), and heterozygous (ma3ma3R) cultivars. GAs were determined in shoots of 14-d-old plants by gas chromatography-selected ion-monitoring-mass spectrometry. GA12 levels fluctuated rhythmically in Ma3Ma3, ma3ma3, and,ma3Rma3R; Peak levels occured 3 to 9 h after lights-on. In some experiments, GA53 levels followed a similar pattern. There was no rhythmicity in levels of GA19 and GA8 in any genotype. In ma3ma3 and Ma3Ma3, GA20 levels increased at lights-on, peaked in the afternoon, and decreased to minimum levels in darkness. In ma3Rma3R, peak GA20 levels occured at lights-on, 9 h earlier than in the wild-type genotypes. The pattern for GA1 levels closely followed GA20 levels in all cultivars. One copy of ma3 restored near wild-type regulation of GA20 levels. GA rhythms persisted in 25-d-old ma3ma3 plants. Since absence of the 123-kD phytochrome disrupted diurnal regulation of the GA19 -> GA20 step, the ma3Rma3R genotype may be viewed as being phase shifted in the rhythmic levels of GA20 and GA1 rather than as simply overproducing them. PMID:12228478

  19. Sodium binding to hH3R and hH 4R--a molecular modeling study.

    PubMed

    Wittmann, Hans-Joachim; Seifert, Roland; Strasser, Andrea

    2014-08-01

    Several aminergic GPCRs, e.g., the human histamine H3-receptor (hH3R) are sensitive to sodium ions. Based on these experimental results, including site directed mutagenesis studies, a sodium binding pocket near to the highly conserved Asp2.50 was suggested. Recently, in the crystallized adenosine A2A receptor (4EIY), a sodium ion was found in a pocket, coordinated by Asp52, Ser91, and three water molecules. Despite high homology in amino acid sequence between hH3R and hH4R, pharmacological studies revealed that the hH4R is--in contrast to hH3R--not sensitive to sodium ions. In order to obtain a deeper insight onto the differences in sodium sensitivity between hH3R and hH4R, we performed molecular modelling studies, including molecular dynamic simulations and calculation of Gibbs energy of solvation. The results of the modeling studies suggested that the amino acid at position 7.42 influences sodium binding to aminergic GPCRs in different ways. A comparison of the amino acids forming the sodium binding channel between the ligand binding pocket and the sodium binding pocket of all human aminergic GPCRs showed an 80% occurrence of glycine--in contrast to hH3R and hH4R. The Gln7.42 at hH4R disrupts a water chain, connecting the Asp3.32 of the orthosteric binding site and the Asp2.50 of the allosteric binding site. Besides, the oxygen of the glutamine side chain stabilizes the interaction of the sodium ion with the Asp3.32. Thus, the binding of the sodium into the allosteric binding site might be hindered kinetically.

  20. Interaction Between ACE I/D and ACTN3 R557X Polymorphisms in Polish Competitive Swimmers.

    PubMed

    Grenda, Agata; Leońska-Duniec, Agata; Kaczmarczyk, Mariusz; Ficek, Krzysztof; Król, Paweł; Cięszczyk, Paweł; Zmijewski, Piotr

    2014-09-29

    We hypothesized that the ACE ID / ACTN3 R577X genotype combination was associated with sprint and endurance performance. Therefore, the purpose of the present study was to determine the interaction between both ACE ID and ACTN3 R577X polymorphisms and sprint and endurance performance in swimmers. Genomic DNA was extracted from oral epithelial cells using GenElute Mammalian Genomic DNA Miniprep Kit (Sigma, Germany). All samples were genotyped using a real-time poly- merase chain reaction. The ACE I/D and the ACTN3 R577X genotype frequencies met Hardy-Weinberg expectations in both swimmers and controls. When the two swimmer groups, long distance swimmers (LDS) and short distance swimmers (SDS), were compared with control subjects in a single test, a significant association was found only for the ACE polymorphism, but not for ACTN3. Additionally, four ACE/ACTN3 combined genotypes (ID/RX, ID/XX, II/RX and II/XX) were statistically significant for the LDS versus Control comparison, but none for the SDS versus Control comparison. The ACE I/D and the ACTN3 R577X polymorphisms did not show any association with sprint swimming, taken individually or in combination. In spite of numerous previous reports of associations with athletic status or sprint performance in other sports, the ACTN3 R577X polymorphism, in contrast to ACE I/D, was not significantly associated with elite swimming status when considered individually. However, the combined analysis of the two loci suggests that the co-occurrence of the ACE I and ACTN3 X alleles may be beneficial to swimmers who compete in long distance races.

  1. The effects of D3R on TLR4 signaling involved in the regulation of METH-mediated mast cells activation.

    PubMed

    Xue, Li; Geng, Yan; Li, Ming; Jin, Yao-Feng; Ren, Hui-Xun; Li, Xia; Wu, Feng; Wang, Biao; Cheng, Wei-Ying; Chen, Teng; Chen, Yan-Jiong

    2016-07-01

    Accumulating studies have revealed that the dopamine D3 receptor (D3R) plays an important role in methamphetamine (METH) addiction. However, the action of D3R on METH-mediated immune response and the underlying mechanism remain unclear. Mast cells (MCs) are currently identified as effector cells in many processes of immune responses, and MC activation is induced by various stimuli such as lipopolysaccharide (LPS). Moreover, CD117 and FcεRI are known as MC markers due to their specific expression in MCs. To investigate the effects of D3R on METH-mediated alteration of LPS-induced MCs activation and the underlying mechanism, in this study, we examined the expression of CD117 and FcεRI in the intestines of wild-type (D3R(+/+)) and D3R-deficient (D3R(-/-)) mice. We also measured the production of MC-derived cytokines, including TNF-α, IL-6, IL-4, IL-13 and CCL-5, in the bone marrow-derived mast cells (BMMCs) of WT and D3R(-/-) mice. Furthermore, we explored the effects of D3R on METH-mediated TLR4 and downstream MAPK and NF-κB signaling induced by LPS in mouse BMMCs. We found that METH suppressed MC activation induced by LPS in the intestines of D3R(+/)mice. In contrast, LPS-induced MC activation was less affected by METH in D3R(-/-) mice. Furthermore, METH altered LPS-induced cytokine production in BMMCs of D3R(+/+) mice but not D3R(-/-) mice. D3R was also involved in METH-mediated modulation of LPS-induced expression of TLR4 and downstream MAPK and NF-κB signaling molecules in mouse BMMCs. Taken together, our findings demonstrate that the effect of D3R on TLR4 signaling may be implicated in the regulation of METH-mediated MCs activation induced by LPS.

  2. H2S, a novel gasotransmitter, involves in gastric accommodation.

    PubMed

    Xiao, Ailin; Wang, Hongjuan; Lu, Xin; Zhu, Jianchun; Huang, Di; Xu, Tonghui; Guo, Jianqiang; Liu, Chuanyong; Li, Jingxin

    2015-11-04

    H2S is produced mainly by two enzymes:cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE), using L-cysteine (L-Cys) as the substrate. In this study, we investigated the role of H2S in gastric accommodation using CBS(+/-) mice, immunohistochemistry, immunoblot, methylene blue assay, intragastric pressure (IGP) recording and electrical field stimulation (EFS). Mouse gastric fundus expressed H2S-generating enzymes (CBS and CSE) and generated detectable amounts of H2S. The H2S donor, NaHS or L-Cys, caused a relaxation in either gastric fundus or body. The gastric compliance was significantly increased in the presence of L-Cys (1 mM). On the contrary, AOAA, an inhibitor for CBS, largely inhibited gastric compliance. Consistently, CBS(+/-) mice shows a lower gastric compliance. However, PAG, a CSE inhibitor, had no effect on gastric compliances. L-Cys enhances the non-adrenergic, non-cholinergic (NANC) relaxation of fundus strips, but AOAA reduces the magnitude of relaxations to EFS. Notably, the expression level of CBS but not CSE protein was elevated after feeding. Consistently, the production of H2S was also increased after feeding in mice gastric fundus. In addition, AOAA largely reduced food intake and body weight in mice. Furthermore, a metabolic aberration of H2S was found in patients with functional dyspepsia (FD). In conclusion, endogenous H2S, a novel gasotransmitter, involves in gastric accommodation.

  3. Role of H2S Donors in Cancer Biology.

    PubMed

    Lee, Zheng-Wei; Deng, Lih-Wen

    2015-01-01

    Hydrogen sulfide (H2S) donors including organosulfur compounds (OSC), inorganic sulfide salts, and synthetic compounds are useful tools in studies to elucidate the effects of H2S in cancer biology. Studies using such donors have shown the ability of H2S to suppress tumor growth both in vitro and in vivo, with some of them suggesting the selectivity of its cytotoxic effects to cancer cells. In addition to promoting cancer cell death, H2S donors were also found to inhibit cancer angiogenesis and metastasis. The underlying mechanisms for the anticancer activities of H2S involve (1) cell signaling pathways, such as MAPK and STAT; (2) cell cycle regulation; (3) microRNAs regulation; and (4) cancer metabolism and pH regulation. Altogether, compiling evidences have demonstrated the great potential of using H2S donors as anticancer agents. Nevertheless, the application and development of H2S for therapy are still facing challenges as identification of molecular targets of H2S awaits further investigation.

  4. Crystal growth simulations of H(2)S hydrate.

    PubMed

    Liang, Shuai; Kusalik, Peter G

    2010-07-29

    In this paper, we report a molecular simulation study exploring the crystal growth behavior of H(2)S hydrates within two-phase (H(2)S hydrate crystal and H(2)S aqueous solution) and three-phase (H(2)S hydrate crystal, liquid H(2)S, and H(2)S aqueous solution) systems. The microscopic mechanisms of growth, as well as the interfacial properties during the heterogeneous crystal growth process, are probed. We find that the H(2)S hydrate can be grown at a higher rate than methane hydrates under comparable conditions (Vatamanu, J.; Kusalik, P. G. J. Phys. Chem. B 2006, 110, 15896). The three-phase simulations, which also allow us to identify the simulation conditions on the experimental phase diagram, demonstrate that the present models reasonably reproduce the phase behavior of this system. We find that the crystal interface has a strong affinity for water molecules. We observed a relatively low level of defects in the newly formed H(2)S hydrate crystal.

  5. Endogenous mitigation of H2S inside of the landfills.

    PubMed

    Fang, Yuan; Zhong, Zhong; Shen, Dongsheng; Du, Yao; Xu, Jing; Long, Yuyang

    2016-02-01

    Vast quantities of hydrogen sulfide (H2S) emitted from landfill sites require urgent disposal. The current study focused on source control and examined the migration and conversion behavior of sulfur compounds in two lab-scale simulated landfills with different operation modes. It aimed to explore the possible strategies and mechanisms for H2S endogenous mitigation inside of landfills during decomposition. It was found that the strength of H2S emissions from the landfill sites was dependent on the municipal solid waste (MSW) degradation speed and vertical distribution of sulfide. Leachate recirculation can shorten both the H2S influence period and pollution risk to the surrounding environment. H2S endogenous mitigation may be achieved by chemical oxidation, biological oxidation, adsorption, and/or precipitation in different stages. Migration and conversion mainly affected H2S release behavior during the initial stabilization phase in the landfill. Microbial activities related to sulfur, nitrogen, and iron can further promote H2S endogenous mitigation during the high reducing phase. Thus, H2S endogenous mitigation can be effectively enhanced via control of the aforementioned processes.

  6. [3Fe-4S] <--> [4Fe-4S] cluster interconversion in Desulfovibrio africanus ferredoxin III: properties of an Asp14 --> Cys mutant.

    PubMed Central

    Busch, J L; Breton, J L; Bartlett, B M; Armstrong, F A; James, R; Thomson, A J

    1997-01-01

    The 8Fe ferredoxin III from Desulfovibrio africanus is a monomeric protein which contains two [4Fe-4S]2+/1+ clusters, one of which is labile and can readily and reversibly lose one Fe under oxidative conditions to yield a [3Fe-4S]1+/0 cluster. This 4Fe cluster has an S = 3/2 ground sping state insteaed of S = 1/2 in the reduced +1 state [George, Armstrong, Hatchikian and Thomson (1989) Biochem. J. 264, 275-284]. The co-ordination to this cluster is unusual in that an aspartate (Asp14, D14, is found where a cysteine residue normally occurs. Using a mutant protein obtained from the overexpression in Escherichia coli of a synthetic gene in which Asp14, the putative ligand to the removable Fe, has been changed to Cys, we have studied the cluster interconversion properties of the labile cluster. Analysis by EPR and magnetic-circular-dichroism spectroscopies showed that the Asp14 --> Cys (D14C) mutant contains two [4Fe-4S]2+/1+ clusters, both with S = 1/2 in the reduced state. Also, unlike in native 8Fe D. africanus ferredoxin III, the 4Fe <--> 3Fe cluster interconversion reaction was found to be sluggish and did not go to completion. It is inferred that the reversibility of the reaction in the native protein is due to the presence of the aspartate residue at position 14 and that this residue might protect the [3Fe-4S] cluster from further degradation. PMID:9173907

  7. [3Fe-4S] <--> [4Fe-4S] cluster interconversion in Desulfovibrio africanus ferredoxin III: properties of an Asp14 --> Cys mutant.

    PubMed

    Busch, J L; Breton, J L; Bartlett, B M; Armstrong, F A; James, R; Thomson, A J

    1997-04-01

    The 8Fe ferredoxin III from Desulfovibrio africanus is a monomeric protein which contains two [4Fe-4S]2+/1+ clusters, one of which is labile and can readily and reversibly lose one Fe under oxidative conditions to yield a [3Fe-4S]1+/0 cluster. This 4Fe cluster has an S = 3/2 ground sping state insteaed of S = 1/2 in the reduced +1 state [George, Armstrong, Hatchikian and Thomson (1989) Biochem. J. 264, 275-284]. The co-ordination to this cluster is unusual in that an aspartate (Asp14, D14, is found where a cysteine residue normally occurs. Using a mutant protein obtained from the overexpression in Escherichia coli of a synthetic gene in which Asp14, the putative ligand to the removable Fe, has been changed to Cys, we have studied the cluster interconversion properties of the labile cluster. Analysis by EPR and magnetic-circular-dichroism spectroscopies showed that the Asp14 --> Cys (D14C) mutant contains two [4Fe-4S]2+/1+ clusters, both with S = 1/2 in the reduced state. Also, unlike in native 8Fe D. africanus ferredoxin III, the 4Fe <--> 3Fe cluster interconversion reaction was found to be sluggish and did not go to completion. It is inferred that the reversibility of the reaction in the native protein is due to the presence of the aspartate residue at position 14 and that this residue might protect the [3Fe-4S] cluster from further degradation.

  8. Electron Excitation Cross Sections for the 2s(sup 2)2p(sup 3) (sup 4)S -> 2s(sup 2)2p(sup 3) (sup 2d) ->2s2p(sup 4) (sup 4p) (Resonance) Transitions in Oil

    NASA Technical Reports Server (NTRS)

    Zuo, M.; Smith, S.; Chutjian, A.; Williams, I.; Tayal, S.; McLaughlin, B.

    1994-01-01

    Experimental and theoretical excitation cross sections are reported for the first forbidden transition xxx and the first allowed (resonance) transition xxx in OII. Use is made of electron-energy loss and merged beams methods. The electron energy range covered is 3.33 eV (threshold) to 15 eV for the S->D transition, and 14.9 eV (threshold) to 40 eV for the S->P transition. Care was taken to assess and minimize the metastable fraction of the OII beam. An electron mirror was designed and tested to reflect inelastically back-scattered electrons into the forward direction to account for the full range of polar scattering angles. Comparisons are made between present experiments and 11-state R-Matrix calculations. Calculations are also presented for the xxx transition.

  9. Renierite, Cu10ZnGe2Fe4S16-Cu11GeAsFe4S16: a coupled solid solution series.

    USGS Publications Warehouse

    Bernstein, L.R.

    1986-01-01

    The composition of renierite is found to be Cu10(Zn1-xCux)Ge2-xAsxFe4S16 (0 = or < x = or < 1), with continuous solid solution between the zincian and arsenian end-members, Cu10ZnGe2Fe4S16 and Cu11GeAsFe4S16, through the coupled substitution Zn(II) + Ge(IV) = Cu(I) + As(V). This is the first reported example of extensive coupled solid solution in a sulphide mineral. Arsenian renierite, not previously characterized, is similar to zincian renierite in polished section, with a slightly redder colour and lower anisotropy. It is reddish orange with relief very similar to that of bornite, though it is harder (VHN25 = 286) and does not tarnish in air. It is slightly bireflective, with colours varying from orange-yellow to reddish orange in nearly crossed polarizers. The strongest powder XRD lines are: 3.042(100), 1.861(29), 1.869(16), 1.594(11) and 1.017(10) A; D(calc.) 4.50 g/cm3. Specimens have been found at the Ruby Creek copper deposit, Alaska, where zincian renierite also occurs, and at the Inexco no. 1 mine, Jamestown, Colorado.-J.A.Z.

  10. Quick Fabrication and Thermoelectric Properties of Cu12Sb4S13 Tetrahedrite

    NASA Astrophysics Data System (ADS)

    Wang, Juyi; Gu, Ming; Bao, Yefeng; Li, Xiaoya; Chen, Lidong

    2016-04-01

    Tetrahedrites, comprised mainly of earth-abundant and environment-friendly elements, copper and sulfur, may pave the way to many new and low-cost thermoelectric energy generation opportunities. However, the preparation of tetrahedrites is time- and energy-consuming. In this paper, we study the melting process and the effect of the annealing time on the microstructure and thermoelectric properties of the Cu12Sb4S13 tetrahedrite, in an effort to shorten the synthesis (melting and annealing) time. Our results show that the Cu12Sb4S13 tetrahedrite phase forms in the melt during cooling. Shortening the melting time does not affect the formation of Cu12Sb4S13. The cooled ingot consists of the principal phase of Cu12Sb4S13 and two secondary phases, Cu3SbS4 and CuSbS2. It is found that prolonged annealing cannot eliminate the impurity phases in Cu12Sb4S13 tetrahedrite, has a small effect on the electrical resistivity, and a negligible effect on the Seebeck coefficient and the thermal conductivity of the tetrahedrite. All our samples have a ZT above 0.47 at 600 K and the maximum ZT obtained was 0.52 when the sample was annealed for 1 day. Based on our experimental results, the time for preparing the Cu12Sb4S13 tetrahedrite can be considerably shortened.

  11. NsrR from Streptomyces coelicolor Is a Nitric Oxide-sensing [4Fe-4S] Cluster Protein with a Specialized Regulatory Function*

    PubMed Central

    Crack, Jason C.; Munnoch, John; Dodd, Erin L.; Knowles, Felicity; Al Bassam, Mahmoud M.; Kamali, Saeed; Holland, Ashley A.; Cramer, Stephen P.; Hamilton, Chris J.; Johnson, Michael K.; Thomson, Andrew J.; Hutchings, Matthew I.; Le Brun, Nick E.

    2015-01-01

    The Rrf2 family transcription factor NsrR controls expression of genes in a wide range of bacteria in response to nitric oxide (NO). The precise form of the NO-sensing module of NsrR is the subject of controversy because NsrR proteins containing either [2Fe-2S] or [4Fe-4S] clusters have been observed previously. Optical, Mössbauer, resonance Raman spectroscopies and native mass spectrometry demonstrate that Streptomyces coelicolor NsrR (ScNsrR), previously reported to contain a [2Fe-2S] cluster, can be isolated containing a [4Fe-4S] cluster. ChIP-seq experiments indicated that the ScNsrR regulon is small, consisting of only hmpA1, hmpA2, and nsrR itself. The hmpA genes encode NO-detoxifying flavohemoglobins, indicating that ScNsrR has a specialized regulatory function focused on NO detoxification and is not a global regulator like some NsrR orthologues. EMSAs and DNase I footprinting showed that the [4Fe-4S] form of ScNsrR binds specifically and tightly to an 11-bp inverted repeat sequence in the promoter regions of the identified target genes and that DNA binding is abolished following reaction with NO. Resonance Raman data were consistent with cluster coordination by three Cys residues and one oxygen-containing residue, and analysis of ScNsrR variants suggested that highly conserved Glu-85 may be the fourth ligand. Finally, we demonstrate that some low molecular weight thiols, but importantly not physiologically relevant thiols, such as cysteine and an analogue of mycothiol, bind weakly to the [4Fe-4S] cluster, and exposure of this bound form to O2 results in cluster conversion to the [2Fe-2S] form, which does not bind to DNA. These data help to account for the observation of [2Fe-2S] forms of NsrR. PMID:25771538

  12. H2S2014 in Kyoto: the 3rd International Conference on H2S in Biology and Medicine.

    PubMed

    Kimura, Hideo

    2015-04-30

    About 20 years ago, a pungent gas was found to be the physiological mediator of cognitive function and vascular tone. Since then, studies on hydrogen sulfide (H2S) have uncovered its numerous physiological roles such as protecting various tissues/organs from ischemia and regulating inflammation, cell growth, oxygen sensing, and senescence. These effects of H2S were extensively studied, and some of the corresponding mechanisms were also studied in detail. Previous studies on the synergistic interaction between H2S and nitric oxide (NO) have led to the discovery of several potential signaling molecules. Polysulfides are considerably potent and are one of the most active forms of H2S. H2S has a significant therapeutic potential, which is evident from the large number of novel H2S-donating compounds and substances developed for manipulating endogenous levels of H2S. The Third International Conference on H2S was held in Kyoto in June 2014. One hundred and sixty participants from 21 countries convened in Kyoto to report new advances, discuss conflicting findings, and make plans for future research. This article summarizes each oral presentation presented at the conference.

  13. Improved H{sub 2}S caustic scrubber

    SciTech Connect

    Heisler, S.M.; Cassinis, R.B.; Massey, S.J.

    1997-05-01

    An improved design reduced the operating expense of an H{sub 2}S Caustic Scrubber by over 75%. The scrubber removes approximately 1,300 lb/day H{sub 2}S from 1800 MSCFD of produced gas containing 8,000 ppm H{sub 2}S with mercaptans and 40% CO{sub 2}. The scrubber is based on Dow Chemical`s US Patent No. 2,747,962. The Dow H{sub 2}S Caustic Scrubber principle is based on contacting gas with dilute caustic (5--20% NaOH) then separating the gas from the liquid. H{sub 2}S reacts with the NaOH to produce NaHS, a water soluble salt that can be disposed of in an oilfield waterflood injection or waste water disposal well. Unfortunately, CO{sub 2} also reacts with NaOH to produce Na{sub 2}CO{sub 3}, thereby increasing caustic consumption. Caustic contact time is kept between 0.01 and 0.03 seconds in order to maximize H{sub 2}S removal while minimizing CO{sub 2} removal. Approximately 80--90% of the H{sub 2}S can be removed per stage while removing only 1% of the CO{sub 2}. Improvements to the H{sub 2}S Caustic Scrubber comprise: Redesigning the H{sub 2}S-Caustic contactor; Reducing the dilute caustic concentration; and Optimizing the number of scrubber stages required by polishing with SulfaTreat{reg_sign}.

  14. Fabrication of Infrared Optical Ceramics in the CaLa2S4 - La2S3 Solid Solution System

    NASA Astrophysics Data System (ADS)

    Savage, J. A.; Lewis, K. L.; Kinsman, B. E.; Wilson, A. R.; Riddle, R.

    1986-12-01

    Calcium lanthanum sulphide optical ceramic has been identified as a potential 8-12 μm infrared window material. However, since there is a solid solution region in the phase diagram between CaLa2S4 and La2S3 other compositions from this region may also be of interest. The most promising synthesis route, also used in the present work, appears to be that of sintering a pure sulphide powder to closed porosity followed by hot isostatic pressing to achieve full density. A mixed oxide precursor powder has been made by the evaporative decomposition of solution (EDS) synthesis route in which a mixed nitrate solution was sprayed through a hot furnace. The mixed oxide powder was then fired in an H2S containing gas to synthesise a very fine sulphide powder of a number of compositions in the CaLa2S4 - La2S3 phase diagram. The evolution of the powder synthesis and ceramic processing techniques has enabled a continued improvement in ceramic quality. For example in 1983 a dark brown CaLa2S4 ceramic partially transmitting in the visible and IR but showing extrinsic S03= and SO4= absorptions was prepared by hot pressing followed by annealing in H2S. By 1985 extrinsic absorption free CaS 45 La2S3 55 mole % material transmitting in the visible and IR but showing visible and near IR scatter has been synthesised by sintering and hot isostatic pressing. In 1986 a range of compositions in the CaLa2S4 - La2S3 phase diagram have been prepared in a similar manner.

  15. H2S concentrations in the heart after acute H2S administration: methodological and physiological considerations.

    PubMed

    Sonobe, Takashi; Haouzi, Philippe

    2016-12-01

    In this study, we have tried to characterize the limits of the approach typically used to determine H2S concentrations in the heart based on the amount of H2S evaporating from heart homogenates-spontaneously, after reaction with a strong reducing agent, or in a very acidic solution. Heart homogenates were prepared from male rats in control conditions or after H2S infusion induced a transient cardiogenic shock (CS) or cardiac asystole (CA). Using a method of determination of gaseous H2S with a detection limit of 0.2 nmol, we found that the process of homogenization could lead to a total disappearance of free H2S unless performed in alkaline conditions. Yet, after restoration of neutral pH, free H2S concentration from samples processed in alkaline and nonalkaline milieus were similar and averaged ∼0.2-0.4 nmol/g in both control and CS homogenate hearts and up to 100 nmol/g in the CA group. No additional H2S was released from control, CS, or CA hearts by using the reducing agent tris(2-carboxyethyl)phosphine or a strong acidic solution (pH < 2) to "free" H2S from combined pools. Of note, the reducing agent DTT produced a significant sulfide artifact and was not used. These data suggest that 1) free H2S found in heart homogenates is not a reflection of H2S present in a "living" heart and 2) the pool of combined sulfides, released in a strong reducing or acidic milieu, does not increase in the heart in a measurable manner even after toxic exposure to sulfide.

  16. Characterization of the binding of benzo(a)pyrene (BP) to a 4S cytosolic protein

    SciTech Connect

    Houser, W.H.; Zielinski, R.; Bresnick, E.

    1986-03-01

    The authors have recently reported on the partial purification of a 4S binding protein that interacts in a specific and saturable manner with (/sup 3/H)BP and other polycyclic aromatic hydrocarbons (PAH). They also reported that the 4S binding protein was able to interact in a specific and saturable manner with plasmids collectively containing the rat cytochrome P450c gene. The authors have examined further the (/sup 3/H)BP binding properties of the 4S protein. The specific (/sup 3/H)BP binding activity appears to be highest in 4 week old male rats and declines with age. In some animals the specific (/sup 3/H)BP binding activity is induced after pretreatment with either phenobarbital (BP) or isosafrole (IS) as evidenced by a 75% and 52% increase, respectively, over untreated controls. No apparent increase was observed after pretreatment of animals with 3-methylcholanthracene (3MC). The addition of a 200 fold excess of tetra-chlordibenzofuran (TCDBF) to the incubations did not displace (/sup 3/H)BP from the 4S protein. The addition of molybdate (10 mM) to isolation buffers, known to stabilize certain hormone receptors, did not alter the sedimentation coefficient or the specific binding activity of the 4S protein. The authors conclude that: (1) in the rat, the 4S protein appears to be distinct from the 8S protein reported in the mouse and that: (2) the 4S species regulates the PAH induced expression of AHH activity in the rat.

  17. Crystal Splitting in the Growth of Bi2S3

    SciTech Connect

    Tang, Jing; Alivisatos, A. Paul

    2006-06-15

    Novel Bi{sub 2}S{sub 3} nanostructures with a sheaf-like morphology are obtained via reaction of bismuth acetate-oleic acid complex with elemental sulfur in 1-octadecence. We propose these structures form by the splitting crystal growth mechanism, which is known to account for the morphology some mineral crystals assume in nature. By controlling the synthetic parameters, different forms of splitting, analogous to observed in minerals, are obtained in our case of Bi{sub 2}S{sub 3}. These new and complex Bi{sub 2}S{sub 3} nanostructures are characterized by TEM, SEM, XRD and ED.

  18. Treatment of H2S using a horizontal biotrickling filter based on biological activated carbon: reactor setup and performance evaluation.

    PubMed

    Duan, Huiqi; Koe, Lawrence Choon Chiaw; Yan, Rong

    2005-04-01

    Biological treatment is an emerging and prevalent technology for treating off-gases from wastewater treatment plants. The most commonly reported odorous compound in off-gases is hydrogen sulfide (H(2)S), which has a very low odor threshold. A self-designed, bench-scale, cross-flow horizontal biotrickling filter (HBF) operated with bacteria immobilized activated carbon (termed biological activated carbon-BAC), was applied for the treatment of H(2)S. A mixed culture of sulfide-oxidizing bacteria dominated by Acidithiobacillus thiooxidans acclimated from activated sludge was used as bacterial seed and the biofilm was developed by culturing the bacteria in the presence of carbon pellets in mineral medium. HBF performance was evaluated systematically over approximately 120 days, depending on a series of changing factors including inlet H(2)S concentration, gas retention time (GRT), pH of recirculation solution, upset and recovery, sulfate accumulation, pressure drop, gas-liquid ratio, and shock loading. The biotrickling filter system can operate at high efficiency from the first day of operation. At a volumetric loading of 900 m(3) m(-3) h(-1) (at 92 ppmv H(2)S inlet concentration), the BAC exhibited maximum elimination capacity (113 g H(2)S/m(-3) h(-1)) and a removal efficiency of 96% was observed. If the inlet concentration was kept at around 20 ppmv, high H(2)S removal (over 98%) was achieved at a GRT of 4 s, a value comparable with those currently reported for biotrickling filters. The bacterial population in the acidic biofilter demonstrated capacity for removal of H(2)S over a broad pH range (pH 1-7). A preliminary investigation into the different effects of bacterial biodegradation and carbon adsorption on system performance was also conducted. This study shows the HBF to be a feasible and economic alternative to physical and chemical treatments for the removal of H(2)S.

  19. Tellurium(0) as a ligand: synthesis and characterization of 2-pyridyltellurolates of platinum(II) and structures of [Pt{2-Te-3-(R)C5H3N}2Te(PR'3)] (R = H or Me).

    PubMed

    Chauhan, Rohit Singh; Kedarnath, G; Wadawale, Amey; Muñoz-Castro, Alvaro; Arratia-Perez, Ramiro; Jain, Vimal K; Kaim, Wolfgang

    2010-05-03

    Treatment of toluene solutions of the ditellurides [Te(2){C(5)H(3)N(R)-3}(2)] (R = H or Me) with [Pt(PPh(3))(4)] yielded two types of complexes, [Pt{2-Te-3-(R)C(5)H(3)N}(2)(PPh(3))(2)] (1a-d) as the major products and [Pt{2-Te-3-(R)C(5)H(3)N}(2)Te(PPh(3))] (2a-d) as minor products. The above complexes can also be obtained by the reaction of [PtCl(2)(PR'(3))(2)] (PR'(3) = PPh(3) or PPh(2)(2-C(5)H(4)N)) with 2 equiv of Na(2-Te-C(5)H(3)R). The complexes were characterized by elemental analyses and UV-vis, NMR ((1)H and (31)P), and (in part) XPS spectroscopy. The molecular structures of [Pt(2-Te-C(5)H(4)N)(2)Te(PPh(3))] (2a) and [Pt{2-Te-C(5)H(3)(Me)N}(2)Te(PPh(3))] (2b) were established by single crystal X-ray diffraction. Both complexes exhibit a distorted square-planar configuration at the platinum(II) centers. The two mutually trans positioned 2-pyridinetellurolate ligands [2-Te-C(5)H(3)(R)N] coordinate to the central platinum atom in a monodentate fashion through the tellurium atoms. The tellurium(0) atom adopts a "bent T" configuration as it is bridging the 2-Te- C(5)H(3)(R)N molecules via N-Te-N bonds (166 degrees angle) and coordinates to Pt(II) in the trans position to PPh(3). The novel bis(pyridine)tellurium(0) arrangement resembles the bis(pyridine)iodonium structure. The calculated NICS indices and ELF functions clearly show that the compounds 2a and 2b are aromatic in the region defined by the Te-C-N-Te-Pt five-membered rings.

  20. [Decolorization of reactive blue P-3R with microsphere-supported binuclear Manganese complex as a novel heterogeneous CWPO catalyst].

    PubMed

    Song, Min; Zhang, Lin-Ping; Zhong, Yi; Xu, Hong; Mao, Zhi-Ping

    2015-03-01

    Binuclear manganese complex (MnL), with high catalytic activity, was encapsulated into ethyl cellulose microspheres via a microencapsulation technique. The characterization of the catalyst through ICP, UV-VIS, SEM and TEM revealed that MnL was well distributed within the ethyl cellulose matrix. The results of UV-VIS confirmed the structural integrity of MnL after the encapsulation process. The MnL loaded microspheres exhibited an excellent catalytic property in the oxidative decolorization of Reactive Blue P-3R, which was used to simulate the dyestuff wastewater. The dye solution was completely decolorized under the catalyzing action of these microspheres. What's more, these MnL loaded microspheres could be reused for at least 4 times and the decolorization degree of Reactive Blue P-3R was maintained above 70%. The results demonstrated the potential application of the microsphere-supported MnL as a novel heterogeneous CWPO catalyst for the decolorization of wastewater containing dyestuff.

  1. InsP3R-Ca(2+) signaling takes center stage in the hormonal regulation of hepatic gluconeogenesis.

    PubMed

    Matsumoto, Michihiro

    2012-11-01

    During fasting, dephosphorylation-dependent activation of the CREB coactivator CRTC2 by glucagon is crucial for activation of the hepatic gluconeogenic program, but the molecular mechanism by which hormones regulate CRTC2 activation remains unclear. A recent report in Nature showed that PKA-dependent phosphorylation of the inositol-1,4,5-trisphosphate receptor (InsP3R) induces Ca mobilization, leading to increase in the phosphatase activity of calcineurin and the subsequent dephosphorylation of CRTC2, thereby resulting in the induction of gluconeogenic gene expression. It also showed that insulin-dependent phosphorylation of InsP3R by Akt inhibits Ca mobilization and CRTC2 dephosphorylation, resulting in the suppression of gluconeogenesis.

  2. Effective utilization of genetic information for athletes and coaches: focus on ACTN3 R577X polymorphism

    PubMed Central

    Kikuchi, Naoki; Nakazato, Koichi

    2015-01-01

    Training variants (type, intensity, and duration of exercise) can be selected according to individual aims and fitness assessment. Recently, various methods of resistance and endurance training have been used for muscle hypertrophy and VO2max improvement. Although several genetic variants are associated with elite athletic performance and muscle phenotypes, genetic background has not been used as variant for physical training. ACTN3 R577X is a well-studied genetic polymorphism. It is the only genotype associated with elite athletic performance in multiple cohorts. This association is strongly supported by mechanistic data from an Actn3-knockout mouse model. In this review, possible guidelines are discussed for effective utilization of ACTN3 R577X polymorphism for physical training. PMID:26526670

  3. A missense mutation in PIK3R5 gene in a family with ataxia and oculomotor apraxia.

    PubMed

    Al Tassan, Nada; Khalil, Dania; Shinwari, Jameela; Al Sharif, Latifa; Bavi, Prashant; Abduljaleel, Zainularifeen; Abu Dhaim, Nada; Magrashi, Amna; Bobis, Steve; Ahmed, Hala; Alahmed, Samaher; Bohlega, Saeed

    2012-02-01

    Autosomal recessive ataxias are heterogeneous group of disorders characterized by cerebellar atrophy and peripheral sensorimotor neuropathy. Molecular characterization of this group of disorders identified a number of genes contributing to these overlapping phenotypes. Ataxia with oculomotor apraxia type 2 (AOA2) is an autosomal recessive form of ataxia caused by mutations in the SETX gene. We report on a consanguineous family with autosomal recessive inheritance and clinical characteristics of AOA2, and no mutations in the SETX gene. We mapped the AOA locus in this family to chromosome 17p12-p13. Sequencing of all genes in the refined region identified a homozygous missense mutation in PIK3R5 that was absent in 477 normal controls. Our characterization of the PIK3R5 protein and findings suggest that it may play a role in the development of the cerebellum and vermis.

  4. Separation by high-performance liquid chromatography of (3R)- and (3S)-beta-leucine as diastereomeric derivatives.

    PubMed

    Aberhart, D J; Cotting, J A; Lin, H J

    1985-11-15

    For studies on the coenzyme B12-dependent enzyme, leucine-2,3-aminomutase, (3R)- and (3S)-beta-leucines were synthesized. The 10-camphorsulfonamide p-nitrobenzyl esters could be resolved by normal-phase HPLC. A much better separation was obtained by reversed-phase HPLC of the diastereomeric derivatives obtained by treatment of -leucine with Marfey's reagent (N2-(5-fluoro-2,4-dinitrophenyl)-L-alaninamide).

  5. Epac–protein kinase C alpha signaling in purinergic P2X3R-mediated hyperalgesia after inflammation

    PubMed Central

    Gu, Yanping; Li, Guangwen; Chen, Yong; Huang, Li-Yen Mae

    2016-01-01

    Abstract Sensitization of purinergic P2X3 receptors (P2X3Rs) is a major mechanism contributing to injury-induced exaggerated pain responses. We showed in a previous study that cyclic adenosine monophosphate (cAMP)–dependent guanine nucleotide exchange factor 1 (Epac1) in rat sensory dorsal root ganglia (DRGs) is upregulated after inflammatory injury, and it plays a critical role in P2X3R sensitization by activating protein kinase C epsilon (PKCε) inside the cells. protein kinase C epsilon has been established as the major PKC isoform mediating injury-induced hyperalgesic responses. On the other hand, the role of PKCα in receptor sensitization was seldom considered. Here, we studied the participation of PKCα in Epac signaling in P2X3R-mediated hyperalgesia. The expression of both Epac1 and Epac2 and the level of cAMP in DRGs are greatly enhanced after complete Freund adjuvant (CFA)–induced inflammation. The expression of phosphorylated PKCα is also upregulated. Complete Freund adjuvant (CFA)–induced P2X3R-mediated hyperalgesia is not only blocked by Epac antagonists but also by the classical PKC isoform inhibitors, Go6976, and PKCα-siRNA. These CFA effects are mimicked by the application of the Epac agonist, 8-(4-chlorophenylthio)-2 -O-methyl-cAMP (CPT), in control rats, further confirming the involvement of Epacs. Because the application of Go6976 prior to CPT still reduces CPT-induced hyperalgesia, PKCα is downstream of Epacs to mediate the enhancement of P2X3R responses in DRGs. The pattern of translocation of PKCα inside DRG neurons in response to CPT or CFA stimulation is distinct from that of PKCε. Thus, in contrast to prevalent view, PKCα also plays an essential role in producing complex inflammation-induced receptor-mediated hyperalgesia. PMID:26963850

  6. PHONON DEPENDENCE ON THERMAL PROPERTIES OF RGaO3(R = La, Ce, Nd, Pr, Sm, Gd)

    NASA Astrophysics Data System (ADS)

    Parveen, Atahar; Gaur, N. K.

    2012-03-01

    We have systematically investigated the effect of phonons on elastic, thermal and cohesive properties for rare earth gallates RGaO3(R = La, Ce, Nd, Pr, Sm, Gd) by means of a Rigid Ion Model after modifying its framework to incorporate the van der Waals interactions. Besides that, we have calculated the temperature dependence of the specific heat for the present orthogallates. The results on bulk modulus, Debye temperature and specific heat reproduce well with the available experimental data.

  7. Hydrogeologic Assessment of the 4-S Land and Cattle CompanyRanch

    SciTech Connect

    Quinn, Nigel W.T.

    2006-04-10

    Hydrogeological assessment of the 4-S Land and Cattle Company (4-S Ranch) was conducted using a combination of field investigations and a survey of available literature from nearby agricultural water districts and other entities. The 4-S Ranch has been able to meet most of its own water needs providing irrigated pasture for beef cattle by an active program of shallow groundwater pumping in these miconfined aquifer above the Corcoran Clay. Comparison of groundwater pumping on the 4-S Ranch property with groundwater pumping in the adjacent Merquin and Stevinson Water Districts shows great similarity in the well screened depths and the quality of the groundwater produced by the well fields. The pump yield for the eight active production wells on the 4-S property are comparable to the production and drainage wells in the adjacent water districts. Like these Districts the 4-S Ranch lies close to the Valley trough in a historic discharge area. The 4-S Ranch is unique in that it is bounded and bisected by several major water conveyance facilities including Bear Creek. Although the large number of potential recharge structures would suggest significant groundwater conjunctive use potential the major well field development has occurred along the length of the Eastside Canal. The Eastside Canal is known to be leaky above the ''A'' Clay the Canal passes through sandy areas and experiences significant groundwater seepage. This seepage can be intercepted by adjacent groundwater wells. Pumping adjacent to, and along the alignment of the Canal, may induce higher rates of seepage from the Eastside Canal. Groundwater quality below and adjacent to the Eastside Canal is very good, reflecting the origin of this diverted water from the Merced River. Most of the pumpage occurs in a depth interval between 30 ft and 130 ft. Safe yield estimates made using the available data show that the 4-S Ranch has sufficient resources to meet its own needs. Further exploitation of the groundwater will

  8. The triple helical structure and stability of collagen model peptide with 4(S)-hydroxyprolyl-Pro-Gly units.

    PubMed

    Motooka, Daisuke; Kawahara, Kazuki; Nakamura, Shota; Doi, Masamitsu; Nishi, Yoshinori; Nishiuchi, Yuji; Kang, Young Kee; Nakazawa, Takashi; Uchiyama, Susumu; Yoshida, Takuya; Ohkubo, Tadayasu; Kobayashi, Yuji

    2012-01-01

    Extensive studies on the structure of collagen have revealed that the hydroxylation of Pro residues in a variety of model peptides with the typical (X-Y-Gly)(n) repeats (X and Y: Pro and its analogues) represents one of the major factors influencing the stability of triple helices. While(2S,4R)-hydroxyproline (Hyp) at the position Y stabilizes the triple helix, (2S,4S)-hydroxyproline (hyp) at the X-position destabilizes the helix as demonstrated that the triple helix of (hyp-Pro-Gly)(15) is less stable than that of (Pro-Pro-Gly)(15) and that a shorter peptide (hyp-Pro-Gly)(10) does not form the helix. To clarify the role of the hydroxyl group of Pro residues to play in the stabilization mechanism of the collagen triple helix, we synthesized and crystallized a model peptide (Pro-Hyp-Gly)(4) -(hyp-Pro-Gly)(2) -(Pro-Hyp-Gly)(4) and analyzed its structure by X-ray crystallography and CD spectroscopy. In the crystal, the main-chain of this peptide forms a typical collagen like triple helix. The majority of hyp residues take down pucker with exceptionally shallow angles probably to relieve steric hindrance, but the remainders protrude the hydroxyl group toward solvent with the less favorable up pucker to fit in a triple helix. There is no indication of the existence of an intra-molecular hydrogen bond between the hydroxyl moiety and the carbonyl oxygen of hyp supposed to destabilize the triple helix. We also compared the conformational energies of up and down packers of the pyrrolidine ring in Ac-hyp-NMe(2) by quantum mechanical calculations.

  9. Chloroplast HCF101 is a scaffold protein for [4Fe-4S] cluster assembly

    PubMed Central

    Schwenkert, Serena; Netz, Daili J. A.; Frazzon, Jeverson; Pierik, Antonio J.; Bill, Eckhard; Gross, Jeferson; Lill, Roland; Meurer, Jörg

    2009-01-01

    Oxygen-evolving chloroplasts possess their own iron-sulfur cluster assembly proteins including members of the SUF (sulfur mobilization) and the NFU family. Recently, the chloroplast protein HCF101 (high chlorophyll fluorescence 101) has been shown to be essential for the accumulation of the membrane complex Photosystem I and the soluble ferredoxin-thioredoxin reductases, both containing [4Fe-4S] clusters. The protein belongs to the FSC-NTPase ([4Fe-4S]-cluster-containing P-loop NTPase) superfamily, several members of which play a crucial role in Fe/S cluster biosynthesis. Although the C-terminal ISC-binding site, conserved in other members of the FSC-NTPase family, is not present in chloroplast HCF101 homologues using Mössbauer and EPR spectroscopy, we provide evidence that HCF101 binds a [4Fe-4S] cluster. 55Fe incorporation studies of mitochondrially targeted HCF101 in Saccharomyces cerevisiae confirmed the assembly of an Fe/S cluster in HCF101 in an Nfs1-dependent manner. Site-directed mutagenesis identified three HCF101-specific cysteine residues required for assembly and/or stability of the cluster. We further demonstrate that the reconstituted cluster is transiently bound and can be transferred from HCF101 to a [4Fe-4S] apoprotein. Together, our findings suggest that HCF101 may serve as a chloroplast scaffold protein that specifically assembles [4Fe-4S] clusters and transfers them to the chloroplast membrane and soluble target proteins. PMID:19817716

  10. PHD Finger Recognition of Unmodified Histone H3R2 Links UHRF1 to Regulation of Euchromatic Gene Expression

    SciTech Connect

    E Rajakumara; Z Wang; H Ma; L Hu; H Chen; Y Lin; R Guo; F Wu; H Li; et al.

    2011-12-31

    Histone methylation occurs on both lysine and arginine residues, and its dynamic regulation plays a critical role in chromatin biology. Here we identify the UHRF1 PHD finger (PHD{sub UHRF1}), an important regulator of DNA CpG methylation, as a histone H3 unmodified arginine 2 (H3R2) recognition modality. This conclusion is based on binding studies and cocrystal structures of PHD{sub UHRF1} bound to histone H3 peptides, where the guanidinium group of unmodified R2 forms an extensive intermolecular hydrogen bond network, with methylation of H3R2, but not H3K4 or H3K9, disrupting complex formation. We have identified direct target genes of UHRF1 from microarray and ChIP studies. Importantly, we show that UHRF1's ability to repress its direct target gene expression is dependent on PHD{sub UHRF1} binding to unmodified H3R2, thereby demonstrating the functional importance of this recognition event and supporting the potential for crosstalk between histone arginine methylation and UHRF1 function.

  11. PHD Finger Recognition of Unmodified Histone H3R2 Links UHRF1 to Regulation of Euchromatic Gene Expression

    SciTech Connect

    Rajakumara, Eerappa; Wang, Zhentian; Ma, Honghui; Hu, Lulu; Chen, Hao; Lin, Yan; Guo, Rui; Wu, Feizhen; Li, Haitao; Lan, Fei; Shi, Yujiang Geno; Xu, Yanhui; Patel, Dinshaw J.; Shi, Yang

    2011-08-29

    Histone methylation occurs on both lysine and arginine residues, and its dynamic regulation plays a critical role in chromatin biology. Here we identify the UHRF1 PHD finger (PHD{sub UHRF1}), an important regulator of DNA CpG methylation, as a histone H3 unmodified arginine 2 (H3R2) recognition modality. This conclusion is based on binding studies and cocrystal structures of PHD{sub UHRF1} bound to histone H3 peptides, where the guanidinium group of unmodified R2 forms an extensive intermolecular hydrogen bond network, with methylation of H3R2, but not H3K4 or H3K9, disrupting complex formation. We have identified direct target genes of UHRF1 from microarray and ChIP studies. Importantly, we show that UHRF1's ability to repress its direct target gene expression is dependent on PHD{sub UHRF1} binding to unmodified H3R2, thereby demonstrating the functional importance of this recognition event and supporting the potential for crosstalk between histone arginine methylation and UHRF1 function.

  12. Clinical reappraisal of SHORT syndrome with PIK3R1 mutations: towards recommendation for molecular testing and management.

    PubMed

    Avila, Magali; Dyment, David A; Sagen, Jørn V; St-Onge, Judith; Moog, Ute; Chung, Brian H Y; Mansour, Sahar; Albanese, Assunta; Garcia, Sixto; Ortiz Martin, David; Lopez, Ainhoa Abad; Claudi, Tor; König, Rainer; White, Susan M; Sawyer, Sarah L; Bernstein, Jon A; Slattery, Leah; Jobling, Rebekah K; Yoon, Grace; Curry, Cynthia J; Le Merrer, Martine; Le Luyer, Bernard; Héron, Delphine; Mathieu-Dramard, Michèle; Bitoun, Pierre; Odent, Sylvie; Amiel, Jeanne; Kuentz, Paul; Thevenon, Julien; Laville, Martine; Reznik, Yves; Fagour, Cédric; Nunes, Marie-Laure; Delesalle, Dorothée; Manouvrier, Sylvie; Lascols, Olivier; Huet, Frédéric; Binquet, Christine; Faivre, Laurence; Rivière, Jean-Baptiste; Vigouroux, Corinne; Njølstad, Pål Rasmus; Innes, A Micheil; Thauvin-Robinet, Christel

    2015-10-24

    SHORT syndrome has historically been defined by its acronym: short stature (S), hyperextensibility of joints and/or inguinal hernia (H), ocular depression (O), Rieger abnormality (R) and teething delay (T). More recently several research groups have identified PIK3R1 mutations as responsible for SHORT syndrome. Knowledge of the molecular etiology of SHORT syndrome has permitted a reassessment of the clinical phenotype. The detailed phenotypes of 32 individuals with SHORT syndrome and PIK3R1 mutation, including eight newly ascertained individuals, were studied to fully define the syndrome and the indications for PIK3R1 testing. The major features described in the SHORT acronym were not universally seen and only half (52%) had 4 or more of the classic features. The commonly observed clinical features of SHORT syndrome seen in the cohort included IUGR < 10(th) percentile, postnatal growth restriction, lipoatrophy and the characteristic facial gestalt. Anterior chamber defects and insulin resistance or diabetes were also observed but were not as prevalent. The less specific, or minor features of SHORT syndrome include teething delay, thin wrinkled skin, speech delay, sensorineural deafness, hyperextensibility of joints and inguinal hernia. Given the high risk of diabetes mellitus, regular monitoring of glucose metabolism is warranted. An echocardiogram, ophthalmological and hearing assessments are also recommended.

  13. Observation of the ηb(2S) Meson in Υ(2S)→γηb(2S), ηb(2S)→ hadrons and confirmation of the ηb(1S) meson.

    PubMed

    Dobbs, S; Metreveli, Z; Tomaradze, A; Xiao, T; Seth, Kamal K

    2012-08-24

    The data for 9.3 million Υ(2S) and 20.9 million Υ(1S) taken with the CLEO III detector have been used to study the radiative population of states identified by their decay into 26 different exclusive hadronic final states. In the Υ(2S) decays, an enhancement is observed at a ~5σ level at a mass of 9974.6±2.3(stat)±2.1(syst) MeV. It is attributed to η(b)(2S) and corresponds to the Υ(2S) hyperfine splitting of 48.7±2.3(stat)±2.1(syst) MeV. In the Υ(1S) decays, the identification of η(b)(1S) is confirmed at a ~3σ level with M[η(b)(1S)] in agreement with its known value.

  14. Photoexcited Carrier Dynamics of Cu2S Thin Films.

    PubMed

    Riha, Shannon C; Schaller, Richard D; Gosztola, David J; Wiederrecht, Gary P; Martinson, Alex B F

    2014-11-20

    Copper sulfide is a simple binary material with promising attributes for low-cost thin film photovoltaics. However, stable Cu2S-based device efficiencies approaching 10% free from cadmium have yet to be realized. In this Letter, transient absorption spectroscopy is used to investigate the dynamics of the photoexcited state of isolated Cu2S thin films prepared by atomic layer deposition or vapor-based cation exchange of ZnS. While a number of variables including film thickness, carrier concentration, surface oxidation, and grain boundary passivation were examined, grain structure alone was found to correlate with longer lifetimes. A map of excited state dynamics is deduced from the spectral evolution from 300 fs to 300 μs. Revealing the effects of grain morphology on the photophysical properties of Cu2S is a crucial step toward reaching high efficiencies in operationally stable Cu2S thin film photovoltaics.

  15. Spectroscopy of the UPSILON(2S) with the Crystal Ball

    SciTech Connect

    Irion, J.

    1985-04-01

    The Crystal Ball experiment has been taking data at the DORIS II storage ring at DESY/Hamburg on the UPSILON(2S) and UPSILON(1S) resonances since summer 1982. Results on the hadronic transitions between the UPSILON(2S) and the UPSILON(1S) are presented as well as measurements of the radiative decays of the UPSILON(2S) to the chi/sub b/ states in inclusive and exclusive channels. The exclusive UPSILON(2S) ..-->.. ..gamma..chi/sub b/ ..-->.. ..gamma gamma..UPSILON(1S) ..-->.. ..gamma gamma..l/sup +/l/sup -/ sample allows a study of the spins of the chi/sub b/ states. Also discussed is the present status of the zeta(8.3) in the radiative decays of the UPSILON(1S). 22 refs., 14 figs.

  16. Measurement of the muonium 1S-2S transition frequency

    SciTech Connect

    Jungmann, K.; Baird, P. E. G.; Barr, J. R. M.; Berkeland, D.; Boshier, M. G.; Braun, B.; Eaton, G. H.; Ferguson, A. I.; Geerds, H.; Hughes, V. W.; Maas, F.; Matthias, B. E.; Matousek, P.; Persaud, M.; Putlitz, G. zu; Reinhard, I.; Riis, E.; Sandars, P. G. H.; Schwarz, W.; Toner, W. T.

    1995-04-01

    Resonant ionization spectroscopy has been employed for measuring the 1{sup 2}S1/2-2{sup 2}S1/2 frequency difference in the hydrogen-like muonium atom to 2 455 529 002(33)(46) MHz. The 1S-2S two-photon transition was induced Doppler-free using two counter-propagating laser beams. The 2S state was photo-ionized by a third photon from the same laser field. The measurement agrees with QED theory within two standard deviations. The mass of the positive muon can be extracted from the isotope shifts in this transition to hydrogen and deuterium to 105.658 80(29)(43) MeV/c{sup 2}.

  17. Baseline Elvs: Delta 2 7920 and Titan 2S SLV

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The baseline mission profiles for two expendable launch vehicles (ELVs) are presented in viewgraph format. The two expendable stage vehicles are the Delta 2 and the Titan 2S. Descriptions are given for both ELV configurations.

  18. Baseline ELVs: Delta 2 7920 and Titan 2S SLV

    NASA Astrophysics Data System (ADS)

    1991-09-01

    The baseline mission profiles for two expendable launch vehicles (ELVs) are presented in viewgraph format. The two expendable stage vehicles are the Delta 2 and the Titan 2S. Descriptions are given for both ELV configurations.

  19. Quantitative photoabsorption and fluorescence spectroscopy of H2S and D2S at 49-240 nm

    NASA Technical Reports Server (NTRS)

    Lee, L. C.; Wang, Xiuyan; Suto, Masako

    1987-01-01

    Photoabsorption and fluorescence cross sections of H2S and D2S were measured in the 49-240 nm region using synchrotron radiation as a light source. Fluorescence from photoexcitation of H2S appears at 49-97 nm, but not in the long wavelength region. Fluorescence spectra were dispersed, and used to identify the emitters to be H2S(+) (A), SH(+)(A), and H(n greater than 2). The fluorescence quantum yield is about 6 percent. Photoexcitation of D2S at 49-96 nm produces fluorescence with a quantum yield of about 5 percent. The emitters are identified from the fluorescence spectra to be D2S(+)(A), SD(+)(A), and D(n greater than 2). The Franck-Condon factors for the SH(+) and SD(+) (A-X) transitions were determined. The SD(A-X) fluorescence was observed from photoexcitation of D2S at 100-151 nm, for which the fluorescence cross section and quantum yield were measured.

  20. Metal Oxide/Zeolite Combination Absorbs H2S

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E.; Sharma, Pramod K.

    1989-01-01

    Mixed copper and molybdenum oxides supported in pores of zeolite found to remove H2S from mixture of gases rich in hydrogen and steam, at temperatures from 256 to 538 degree C. Absorber of H2S needed to clean up gas streams from fuel processors that incorporate high-temperature steam reformers or hydrodesulfurizing units. Zeolites chosen as supporting materials because of their high porosity, rigidity, alumina content, and variety of both composition and form.

  1. Analysis of cardiovascular responses to the H2S donors Na2S and NaHS in the rat

    PubMed Central

    Yoo, Daniel; Jupiter, Ryan C.; Pankey, Edward A.; Reddy, Vishwaradh G.; Edward, Justin A.; Swan, Kevin W.; Peak, Taylor C.; Mostany, Ricardo

    2015-01-01

    Hydrogen sulfide (H2S) is an endogenous gaseous molecule formed from L-cysteine in vascular tissue. In the present study, cardiovascular responses to the H2S donors Na2S and NaHS were investigated in the anesthetized rat. The intravenous injections of Na2S and NaHS 0.03–0.5 mg/kg produced dose-related decreases in systemic arterial pressure and heart rate, and at higher doses decreases in cardiac output, pulmonary arterial pressure, and systemic vascular resistance. H2S infusion studies show that decreases in systemic arterial pressure, heart rate, cardiac output, and systemic vascular resistance are well-maintained, and responses to Na2S are reversible. Decreases in heart rate were not blocked by atropine, suggesting that the bradycardia was independent of parasympathetic activation and was mediated by an effect on the sinus node. The decreases in systemic arterial pressure were not attenuated by hexamethonium, glybenclamide, Nw-nitro-l-arginine methyl ester hydrochloride, sodium meclofenamate, ODQ, miconazole, 5-hydroxydecanoate, or tetraethylammonium, suggesting that ATP-sensitive potassium channels, nitric oxide, arachidonic acid metabolites, cyclic GMP, p450 epoxygenase metabolites, or large conductance calcium-activated potassium channels are not involved in mediating hypotensive responses to the H2S donors in the rat and that responses are not centrally mediated. The present data indicate that decreases in systemic arterial pressure in response to the H2S donors can be mediated by decreases in vascular resistance and cardiac output and that the donors have an effect on the sinus node independent of the parasympathetic system. The present data indicate that the mechanism of the peripherally mediated hypotensive response to the H2S donors is uncertain in the intact rat. PMID:26071540

  2. Analysis of cardiovascular responses to the H2S donors Na2S and NaHS in the rat.

    PubMed

    Yoo, Daniel; Jupiter, Ryan C; Pankey, Edward A; Reddy, Vishwaradh G; Edward, Justin A; Swan, Kevin W; Peak, Taylor C; Mostany, Ricardo; Kadowitz, Philip J

    2015-08-15

    Hydrogen sulfide (H2S) is an endogenous gaseous molecule formed from L-cysteine in vascular tissue. In the present study, cardiovascular responses to the H2S donors Na2S and NaHS were investigated in the anesthetized rat. The intravenous injections of Na2S and NaHS 0.03-0.5 mg/kg produced dose-related decreases in systemic arterial pressure and heart rate, and at higher doses decreases in cardiac output, pulmonary arterial pressure, and systemic vascular resistance. H2S infusion studies show that decreases in systemic arterial pressure, heart rate, cardiac output, and systemic vascular resistance are well-maintained, and responses to Na2S are reversible. Decreases in heart rate were not blocked by atropine, suggesting that the bradycardia was independent of parasympathetic activation and was mediated by an effect on the sinus node. The decreases in systemic arterial pressure were not attenuated by hexamethonium, glybenclamide, N(w)-nitro-L-arginine methyl ester hydrochloride, sodium meclofenamate, ODQ, miconazole, 5-hydroxydecanoate, or tetraethylammonium, suggesting that ATP-sensitive potassium channels, nitric oxide, arachidonic acid metabolites, cyclic GMP, p450 epoxygenase metabolites, or large conductance calcium-activated potassium channels are not involved in mediating hypotensive responses to the H2S donors in the rat and that responses are not centrally mediated. The present data indicate that decreases in systemic arterial pressure in response to the H2S donors can be mediated by decreases in vascular resistance and cardiac output and that the donors have an effect on the sinus node independent of the parasympathetic system. The present data indicate that the mechanism of the peripherally mediated hypotensive response to the H2S donors is uncertain in the intact rat.

  3. B semileptonic decays at the Υ(4S) and the Υ(5S)

    NASA Astrophysics Data System (ADS)

    Yanagisawa, C.; Heintz, U.; Lee-Franzini, J.; Lovelock, D. M. J.; Narain, M.; Schamberger, R. D.; Willins, J.; Franzini, P.; Tuts, P. M.

    1991-05-01

    B-meson semileptonic decay spectra have been obtained at the Υ(4S) and at the Υ(5S) at the Cornell Electron Storage Ring with the Columbia University-Stony Brook detector. The branching ratio for B-->eνX at the Υ(4S) is found to be (10.0+/-0.5)%. The electron spectrum of B-->eνX at the Υ(5S) is observed for the first time and the average branching ratio of B,Bs-->eνX is consistent with that for B's from Υ(4S) decays. The shape of the electron spectrum at the Υ(5S) indicates production of B mesons which are heavier than nonstrange B's, presumably strange B's.

  4. Stoichiometry and local bond configuration of In2S3:Cl thin films by Rutherford backscattering spectrometry

    NASA Astrophysics Data System (ADS)

    Juma, Albert O.

    2016-10-01

    In2S3 thin films deposited using chemical methods always contain residual elements from the precursors, which modify their properties. As buffer layers in solar cells, the residual elements in the In2S3 layer affect the performance of these devices. The stoichiometry of In2S3 thin films deposited by spray ion layer gas reaction (ILGAR) was studied as a function of the residual Cl from InCl3 precursor by varying the deposition parameters. The chemical formula was deduced from the elemental composition determined using Rutherford backscattering (RBS). Incomplete sulfurization of the precursor implies that residual Cl- remains bonded to the In3+ ions while some occupy interstitial and/or antisite positions in the In2S3 matrix. This results in thin films with different stoichiometry, described by the formula In4S6-xCl2x+2y. This changes the local bond configuration and geometry and underpins the influence of residual Cl on the physical properties of In2S3 thin films.

  5. A Turkish family with Ellis-van Creveld syndrome in six siblings; linkage analysis on 4p16 region (D4S3360-D4S2366).

    PubMed

    Cağdaş, D N; Parlar, A I; Pac, A; Tutun, U; Balci, S

    2008-01-01

    We present a Turkish family and their 6 children, consecutively affected by Ellis-van Creveld (EVC) Syndrome. Four of the affected children died in the postnatal period, and 2 of them had been admitted to the pediatric cardiology department for their cardiologic evaluation. Since they had the features of the EVC Syndrome, linkage analysis was performed with the polymorphic markers, D4S3360-D4S2366, selected from 4p 16 locus. There was complete segregation between the disease and marker allels and the two affected siblings were homozygote for the polymorphic markers, as expected in autosomal recessive inheritance. The diagnosis of EVC Syndrome was confirmed by this molecular analysis. Two cases with EVC were presented in this report. Case 1 had partial abnormal pulmonary venous return and pulmonary stenosis additional to ostium primum atrial septal defect and mitral cleft. Partial abnormal pulmonary venous return and pulmonary stenosis were previously not reported with EVC Syndrome. Postaxial polydactyly phenotype of the Case 2 differs from her brother's. There is bifid 5th metacarpal and unilateral (L) bifid middle and distal phalanges resembling syndactyly.

  6. Histamine H3-receptor signaling in cardiac sympathetic nerves: Identification of a novel MAPK-PLA2-COX-PGE2-EP3R pathway.

    PubMed

    Levi, Roberto; Seyedi, Nahid; Schaefer, Ulrich; Estephan, Rima; Mackins, Christina J; Tyler, Eleanor; Silver, Randi B

    2007-04-15

    We hypothesized that the histamine H(3)-receptor (H(3)R)-mediated attenuation of norepinephrine (NE) exocytosis from cardiac sympathetic nerves results not only from a Galpha(i)-mediated inhibition of the adenylyl cyclase-cAMP-PKA pathway, but also from a Gbetagamma(i)-mediated activation of the MAPK-PLA(2) cascade, culminating in the formation of an arachidonate metabolite with anti-exocytotic characteristics (e.g., PGE(2)). We report that in Langendorff-perfused guinea-pig hearts and isolated sympathetic nerve endings (cardiac synaptosomes), H(3)R-mediated attenuation of K(+)-induced NE exocytosis was prevented by MAPK and PLA(2) inhibitors, and by cyclooxygenase and EP(3)-receptor (EP(3)R) antagonists. Moreover, H(3)R activation resulted in MAPK phosphorylation in H(3)R-transfected SH-SY5Y neuroblastoma cells, and in PLA(2) activation and PGE(2) production in cardiac synaptosomes; H(3)R-induced MAPK phosphorylation was prevented by an anti-betagamma peptide. Synergism between H(3)R and EP(3)R agonists (i.e., imetit and sulprostone, respectively) suggested that PGE(2) may be a downstream effector of the anti-exocytotic effect of H(3)R activation. Furthermore, the anti-exocytotic effect of imetit and sulprostone was potentiated by the N-type Ca(2+)-channel antagonist omega-conotoxin GVIA, and prevented by an anti-Gbetagamma peptide. Our findings imply that an EP(3)R Gbetagamma(i)-induced decrease in Ca(2+) influx through N-type Ca(2+)-channels is involved in the PGE(2)/EP(3)R-mediated attenuation of NE exocytosis elicited by H(3)R activation. Conceivably, activation of the Gbetagamma(i) subunit of H(3)R and EP(3)R may also inhibit Ca(2+) entry directly, independent of MAPK intervention. As heart failure, myocardial ischemia and arrhythmic dysfunction are associated with excessive local NE release, attenuation of NE release by H(3)R activation is cardioprotective. Accordingly, this novel H(3)R signaling pathway may ultimately bear therapeutic significance in hyper

  7. Classified computer configuration control system (C{sup 4}S), revision 3, user`s information

    SciTech Connect

    O`Callaghan, P.B.; Nelson, R.A.; Grambihler, A.J.

    1994-04-01

    The Classified Computer Configuration Control System (C{sup 4}S) allows security management to track pertinent information concerning classified computer systems in the scope of their control. Information is entered by the level security manager that is closest to the classified computer system. Managers that are further removed from systems can have consolidated information made available to them. C{sup 4}S can be used to generate reports that are as current as the last information that was entered into the database. C{sup 4}S offers data entry, data display, and data reporting. The user interface uses menus, entry forms, the mouse, and Hot Keys. C{sup 4}S provides help windows that are available at any time by pressing the F1 key. C{sup 4}S has help for each menu, data entry form, and general program information. You can browse a help window by pressing the arrows, page up, or page down keys. You control C{sup 4}S with program options selected from pull-down menus. You {open_quotes}select{close_quotes} by moving a highlight bar up and down or across the menu and pressing enter on one of the options. The highlight bar is moved using the arrow keys, mouse, or selection letters. Notice that a letter of each menu option is a different color from the other letters. This is the selection letter for that option. If you press the selection letter, the highlight bar will move to that option. You can also use a mouse to move the highlight bar to the option by moving the mouse pointer to the option and pressing the mouse button. Explanation of menu options or entry fields appear at the bottom of the screen. These explanations should help you use C{sup 4}S. If you need more help, it is available by pressing F1. C{sup 4}S will bring up a help window for the particular option you are working with. The authors of the program are P.B. O`Callaghan, A. J. Grambihler, and R.A. Nelson.

  8. α-In2S3 and β-In2S3 phases produced by SILAR technique

    NASA Astrophysics Data System (ADS)

    Turan, E.; Zor, M.; Kul, M.; Aybek, A. S.; Taskopru, T.

    2012-05-01

    In2S3 films have been deposited by the successive ionic adsorption and reaction technique (SILAR) at room temperature. The films have been examined to evaluate the structural and optical properties. X-ray diffraction spectra have revealed the presence of both the α-In2S3 (cubic) and β-In2S3 (tetragonal) phases. The presence of the α-In2S3 phase at room temperature is attributed to the richness of In in the deposited materials. The presence of both phases is also supported by FESEM observations. The crystallinity of the material has been observed to improve with increasing thickness. Direct band gap of the deposits decreased from 2.89 to 2.37 eV with increasing thickness.

  9. Hadronic Production of Ψ(2S) Cross section and Polarization

    SciTech Connect

    Chung, Kwangzoo

    2008-05-01

    The hadronic production cross section and the polarization of Ψ(2S) meson are measured by using the data from p$\\bar{p}$ collisions at √s = 1.96 TeV collected by the Collider Detector at Fermilab. The datasets used correspond to integrated luminosity of 1.1 fb-1 and 800 pb-1, respectively. The decay Ψ(2S) → μ+μ- is used to reconstruct Ψ(2S) mesons in the rapidity range |y(Ψ(2S))| < 0.6. The coverage of the pT range is 2.0 GeV/c ≤ pT (Ψ(2S)) < 30 GeV/c for the cross section analysis and pT ≥ 5 GeV/c for the polarization analysis. For events with pT (Ψ(2S)) > 2 GeV/c the integrated inclusive cross section multiplied by the branching ratio for dimuon decay is 3.17 ± 0.04 ± 0.28 nb . This result agrees with the CDF Run I measurement considering the increased center-of-mass energy from 1.8 TeV to 1.96 TeV. The polarization of the promptly produced Ψ(2S) mesons is found to be increasingly longitudinal as pT increases from 5 GeV/c to 30 GeV/c. The result is compared to contemporary theory models.

  10. Structural phase transition and phonon instability in Cu12Sb4S13

    DOE PAGES

    May, Andrew F.; Delaire, Olivier A.; Niedziela, Jennifer L.; ...

    2016-02-08

    In this study, a structural phase transition has been discovered in the synthetic tetrahedrite Cu12Sb4S13 at approximately 88 K. Upon cooling, the material transforms from its known cubic symmetry to a tetragonal unit cell that is characterized by an in-plane ordering that leads to a doubling of the unit cell volume. Specific heat capacity measurements demonstrate a hysteresis of more than two degrees in the associated anomaly. A similar hysteresis was observed in powder x-ray diffraction measurements, which also indicate a coexistence of the two phases, and together these results suggest a first-order transition. This structural transition coincides with amore » recently-reported metal-insulator transition, and the structural instability is related to the very low thermal conductivity κ in these materials. Inelastic neutron scattering was used to measure the phonon density of states in Cu12Sb4S13 and Cu10Zn2Sb4S13, both of which possess a localized, low-energy phonon mode associated with strongly anharmonic copper displacements that suppress κ. In Cu12Sb4S13, signatures of the phase transition are observed in the temperature dependence of the localized mode, which disappears at the structural transition. In contrast, in the cubic Zn-doped material, the mode is at slightly higher-energy but observable for all temperatures, though it softens upon cooling.« less

  11. A de novo designed 2[4Fe-4S] ferredoxin mimic mediates electron transfer.

    PubMed

    Roy, Anindya; Sommer, Dayn Joseph; Schmitz, Robert Arthur; Brown, Chelsea Lynn; Gust, Devens; Astashkin, Andrei; Ghirlanda, Giovanna

    2014-12-10

    [Fe-S] clusters, nature's modular electron transfer units, are often arranged in chains that support long-range electron transfer. Despite considerable interest, the design of biomimetic artificial systems emulating multicluster-binding proteins, with the final goal of integrating them in man-made oxidoreductases, remains elusive. Here, we report a novel bis-[4Fe-4S] cluster binding protein, DSD-Fdm, in which the two clusters are positioned within a distance of 12 Å, compatible with the electronic coupling necessary for efficient electron transfer. The design exploits the structural repeat of coiled coils as well as the symmetry of the starting scaffold, a homodimeric helical protein (DSD). In total, eight hydrophobic residues in the core of DSD were replaced by eight cysteine residues that serve as ligands to the [4Fe-4S] clusters. Incorporation of two [4Fe-4S] clusters proceeds with high yield. The two [4Fe-4S] clusters are located in the hydrophobic core of the helical bundle as characterized by various biophysical techniques. The secondary structure of the apo and holo proteins is conserved; further, the incorporation of clusters results in stabilization of the protein with respect to chemical denaturation. Most importantly, this de novo designed protein can mimic the function of natural ferredoxins: we show here that reduced DSD-Fdm transfers electrons to cytochrome c, thus generating the reduced cyt c stoichiometrically.

  12. Role of the S4-S5 Linker in CNG Channel Activation

    PubMed Central

    Kusch, Jana; Zimmer, Thomas; Holschuh, Jascha; Biskup, Christoph; Schulz, Eckhard; Nache, Vasilica; Benndorf, Klaus

    2010-01-01

    Cyclic nucleotide-gated (CNG) channels mediate sensory signal transduction in retinal and olfactory cells. The channels are activated by the binding of cyclic nucleotides to a cyclic nucleotide-binding domain (CNBD) in the C-terminus that is located at the intracellular side. The molecular events translating the ligand binding to the pore opening are still unknown. We investigated the role of the S4-S5 linker in the activation process by quantifying its interaction with other intracellular regions. To this end, we constructed chimeric channels in which the N-terminus, the S4-S5 linker, the C-linker, and the CNBD of the retinal CNGA1 subunit were systematically replaced by the respective regions of the olfactory CNGA2 subunit. Macroscopic concentration-response relations were analyzed, yielding the apparent affinity to cGMP and the Hill coefficient. The degree of functional coupling of intracellular regions in the activation gating was determined by thermodynamic double-mutant cycle analysis. We observed that all four intracellular regions, including the relatively short S4-S5 linker, are involved in controlling the apparent affinity of the channel to cGMP and, moreover, in determining the degree of cooperativity between the subunits, as derived from the Hill coefficient. The interaction energies reveal an interaction of the S4-S5 linker with both the N-terminus and the C-linker, but no interaction with the CNBD. PMID:20959089

  13. Angular distribution for electron excitation of the 4(2)S yields 4(2)P transition in Zn II - Comparison of experiment and theory

    NASA Technical Reports Server (NTRS)

    Chutjian, A.; Msezane, A. Z.; Henry, R. J. W.

    1983-01-01

    Differential electron-scattering cross sections for inelastic excitation of an ion have been measured for the first time. Experiments were carried out in a cross electron-ion beam geometry for the 4(2)S yields 4(2)P transition in Zn II at 75 eV. In addition, differential cross sections were calculated at energies between 15 and 100 eV in a five-state close-coupling approximation in which 4s, 4p, 3d(9)4s(2), 5s, and 4 d states were included. Agreement in shape between theory and experiment at 75 eV is excellent.

  14. The NASA Dual-Frequency Dual-Polarized Doppler Radar (D3R) System For GPM Ground Validation

    NASA Astrophysics Data System (ADS)

    Chandrasekar, V.; Schwaller, Mathew; Vega, Manuel; Carswell, James; Vijay Mishra, Kumar; Nguyen, Cuong; Meneghini, Robert; Peterson, Walt

    2010-05-01

    Following on the successful introduction of single-frequency (Ku-Band) weather radar onboard the Tropical Rain Measuring Mission (TRMM) satellite in 1997, the Global Precipitation Measurement (GPM) mission attempts to advance further the goal of making global scale precipitation observations by deploying the next generation of satellite-borne weather radars. The GPM satellite will carry a Ka-Ku band Dual-frequency Precipitation Radar (DPR) that can make measurements of parameters directly related to the microphysics of precipitation (such as raindrop size distribution). The Dual-Frequency Dual-Polarized Doppler Radar (D3R) is a ground validation radar, as a part of the GPM Ground Validation (GV) program, to enable both physical validation support in terms of understanding the microphysical description of the observations as well as algorithm retrieval implications. This paper provides a scientific and technical overview of the D3R system as well as major challenges. The preferred frequency bands of operation for precipitation surveillance in ground radar systems have been nearly non-attenuating frequencies (such as S-, C-band) or short-range measurements of attenuating frequencies (as in X band). However, it is not practical to use traditional ground radar frequencies for precipitation observations in space-borne radars. The GPM mission has embarked on a dual-frequency approach at Ku- and Ka-band for characterizing precipitation. Moving to higher frequencies to observe precipitation though has its own challenges namely, attenuation due to precipitation and reduced Doppler velocity Nyquist limits. Ground radar measurements enjoy the advantage of coincident microphysical observations available to interpret radar signatures but they are currently unavailable at Ku- and Ka-band. An important broader science goal of the NASA D3R is to enhance the database of dual-frequency radar observations on the ground, in conjunction with existing observations, in order to provide a

  15. Sensing properties of assembled Bi2S3 nanowire arrays

    NASA Astrophysics Data System (ADS)

    Kunakova, G.; Meija, R.; Bite, I.; Prikulis, J.; Kosmaca, J.; Varghese, J.; Holmes, J. D.; Erts, Donats

    2015-09-01

    Bismuth sulfide (Bi2S3) nanowires were grown in porous aluminium oxide template and a selective chemical etching was applied to transfer the nanowires to a solution. Well aligned nanowire arrays were assembled on pre-patterned silicon substrates employing dielectrophoresis. Electron beam lithography was used to connect aligned individual nanowires to the common macroelectrode. In order to evaluate the conductometric sensing performance of the Bi2S3 nanowires, current-voltage characteristics were measured at different relative humidity (RH) levels (5-80%) / argon medium. The response of the Bi2S3 nanowires depending of RH is found to be considerably different from those reported for other types of nanowire RH sensor devices.

  16. Oxidation of H2S in mammalian cells and mitochondria.

    PubMed

    Abou-Hamdan, Abbas; Guedouari-Bounihi, Hala; Lenoir, Véronique; Andriamihaja, Mireille; Blachier, François; Bouillaud, Frédéric

    2015-01-01

    Hydrogen sulfide (H2S) is the third gasotransmitter described in mammals. These gasotransmitters (H2S, CO, and NO) are small molecules able to diffuse freely across membranes and thus susceptible to reach easily intracellular targets, one of which is the respiratory enzyme cytochrome oxidase subject to complete inhibition by low micromolar concentrations of these gases. However in contrast to NO or CO, H2S can be metabolized by a sulfide quinone reductase feeding the mitochondrial respiratory chain with the hydrogen atoms of sulfide. Sulfide is thus a two-sided molecule: substrate or poison according to the concentration. The aim of this chapter is to present a mean to monitor sulfide oxidation by isolated mitochondria or cells and to summarize how the properties of this amazing couple (mitochondria and sulfide) translate into practical and conceptual consequences.

  17. Strategic focus on 3R principles reveals major reductions in the use of animals in pharmaceutical toxicity testing.

    PubMed

    Törnqvist, Elin; Annas, Anita; Granath, Britta; Jalkesten, Elisabeth; Cotgreave, Ian; Öberg, Mattias

    2014-01-01

    The principles of the 3Rs, Replacement, Reduction and Refinement, are being increasingly incorporated into legislations, guidelines and practice of animal experiments in order to safeguard animal welfare. In the present study we have studied the systematic application of 3R principles to toxicological research in the pharmaceutical industry, with particular focus on achieving reductions in animal numbers used in regulatory and investigatory in vivo studies. The work also details major factors influencing these reductions including the conception of ideas, cross-departmental working and acceptance into the work process. Data from 36 reduction projects were collected retrospectively from work between 2006 and 2010. Substantial reduction in animal use was achieved by different strategies, including improved study design, method development and project coordination. Major animal savings were shown in both regulatory and investigative safety studies. If a similar (i.e. 53%) reduction had been achieved simultaneously within the twelve largest pharmaceutical companies, the equivalent reduction world-wide would be about 150,000 rats annually. The results point at the importance of a strong 3R culture, with scientific engagement, collaboration and a responsive management being vital components. A strong commitment in leadership for the 3R is recommended to be translated into cross-department and inter-profession involvement in projects for innovation, validation and implementation. Synergies between all the three Rs are observed and conclude that in silico-, in vitro- and in vivo-methods all hold the potential for applying the reduction R and should be consequently coordinated at a strategic level.

  18. Metabolism of Lutein and Zeaxanthin in Rhesus Monkeys: Identification of (3R,6′R)- and (3R,6′S)-3′-Dehydro-lutein as Common Metabolites and Comparison to Humans

    PubMed Central

    Albert, Gesa I.; Hoeller, Ulrich; Schierle, Joseph; Neuringer, Martha; Johnson, Elizabeth J.; Schalch, Wolfgang

    2012-01-01

    Lutein and zeaxanthin are xanthophylls that can be found highly concentrated in the macula of the retina. They are thought to protect the macula through their role as blue-light filters and because of their antioxidant and singlet oxygen quenching properties. Examination of metabolites unique to lutein and zeaxanthin such as 3′-dehydro-lutein, and of their stereochemistry may provide insight to the mechanism by which they are formed and by which they exert protection. To evaluate the formation of such metabolites, eleven monkeys were raised on a xanthophyll-free diet, and supplemented with pure lutein or pure zeaxanthin (2.2 mg/kg body weight/d). The period of supplementation ranged between 12 to 92 weeks. At study start and throughout the study, serum samples were taken and analyzed for xanthophylls using different HPLC systems. Xanthophyll metabolites were identified using UV/VIS and HR-MS detection. Lutein and zeaxanthin metabolites were found in detectable amounts with 3′-dehydro-lutein being a common metabolite of both. Using chiral-phase HPLC, two diastereomers, (3R,6′R)-3′-dehydro-lutein and (3R,6′S)-3′-dehydro-lutein, were identified and shown to be present in nearly equimolar amounts. A pathway for their formation from either lutein or zeaxanthin is proposed. These finding were comparable to results obtained with human plasma. PMID:18582588

  19. Hydrogen sulfide (H 2S) in urban ambient air

    NASA Astrophysics Data System (ADS)

    Kourtidis, K.; Kelesis, A.; Petrakakis, M.

    Despite indications of high hydrogen sulfide levels in some urban environments, only sparse measurements have been reported in the literature. Here we present one full year of hydrogen sulfide measurements in an urban traffic site in the city of Thessaloniki, Greece. In this 1-million-population city the H 2S concentrations were surprisingly high, with a mean annual concentration of 8 μg m -3 and wintertime mean monthly concentrations up to 20 μg m -3 (12.9 ppb). Daily mean concentrations in the winter were up to 30 μg m -3 (19.3 ppb), while hourly concentrations were up to 54 μg m -3 (34.8 ppb). During calm (wind velocity < 0.5 m s -1) conditions, mainly encountered during night-time hours, hourly values of H 2S were highly correlated with those of CO ( r2 = 0.75) and SO 2 ( r2 = 0.70), pointing to a common traffic source from catalytic converters. Annual mean concentrations are above the WHO recommendation for odor annoyance; hence, H 2S might play a role to the malodorous episodes that the city occasionally experiences. The high ambient H 2S levels might also be relevant to the implementation of preservation efforts for outdoor marble and limestone historical monuments that have been targeting SO 2 emissions as an atmospheric acidity source, since the measurements presented here suggest that about 19% of the annual sulfur (SO 2 + H 2S) emissions in Thessaloniki are in the form of H 2S.

  20. Extending the time: solvothermal syntheses, crystal structures, and properties of two non-isostructural thioantimonates with the composition [Mn(tren)]Sb2S4.

    PubMed

    Schaefer, Michael; Kurowski, Daniel; Pfitzner, Arno; Näther, Christian; Rejai, Zomaje; Möller, Karina; Ziegler, Nancy; Bensch, Wolfgang

    2006-05-01

    The two novel compounds, [Mn(tren)]Sb2S4 (1 and 2), were obtained by the reaction of elemental Mn, Sb, and S in aqueous solutions of tren (tren = tris(2-aminoethyl)amine, C6H18N4) after different reaction times. Compound 1 is formed up to a reaction time of 13 d, and an extension of the reaction time leads to the formation of 2. Both compounds crystallize in monoclinic space groups (1, P2(1)/c; 2, C2/c). In 1, the two unique SbS3 trigonal pyramids share a common S atom to form a Sb2S5 unit. Two S atoms of this group have a bond to Mn2+ yielding a MnSb2S3 heteroring in the boat conformation. The Sb2S5 moieties are joined via common corners into the final undulated [Sb2S4]2- anion which is directed along [001]. The structure of 2 contains the [Mn(tren)]2+ ion, one SbS3 pyramid, and a SbS4 unit. Two symmetry-related SbS4 groups share an edge, forming a Sb2S6 group containing a Sb2S2 ring. This group is joined via corners to two SbS3 pyramids on both sides producing a Sb4S4 ring. The Sb2S2 and Sb4S4 rings are condensed into the final [Sb2S4]2- anion which runs along [010]. The [Mn(tren)] groups are bound to the thioantimonate(III) backbone on opposite sides of the Sb4S4 ring, and a small MnSbS2 ring is formed. In both structures, weak S...H bonds are found which may contribute to the stability of the materials. The two compounds decompose in one step upon heating, and only MnS and Sb2S3 could be identified as the crystalline part of the decomposition products. Both compounds can also be prepared under solvothermal conditions using MnSb2S4 as starting material. Compounds 1 and 2 are obtained from this ternary material in a high yield.

  1. Molecular docking performance evaluated on the D3R Grand Challenge 2015 drug-like ligand datasets

    NASA Astrophysics Data System (ADS)

    Selwa, Edithe; Martiny, Virginie Y.; Iorga, Bogdan I.

    2016-09-01

    The D3R Grand Challenge 2015 was focused on two protein targets: Heat Shock Protein 90 (HSP90) and Mitogen-Activated Protein Kinase Kinase Kinase Kinase 4 (MAP4K4). We used a protocol involving a preliminary analysis of the available data in PDB and PubChem BioAssay, and then a docking/scoring step using more computationally demanding parameters that were required to provide more reliable predictions. We could evidence that different docking software and scoring functions can behave differently on individual ligand datasets, and that the flexibility of specific binding site residues is a crucial element to provide good predictions.

  2. THERMODYNAMIC PROPERTIES OF THE METALLIC SYSTEM Au(111)-(3×3)R30∘-Pd

    NASA Astrophysics Data System (ADS)

    Chadli, R.; Kheffache, S.; Khater, A.

    2016-02-01

    This work constitutes an analysis of the thermodynamic properties in the ordered metallic surface alloy system Au(111)-(3×3)R30∘-Pd. The equilibrium structural characteristics as well as the thermodynamic functions are examined by the matching method, associated with real space Green’s function formalism, evaluated in the harmonic approximation. Our numerical results, for this metallic system of surface alloy, show in particular a significant dependence between the thermodynamic properties and the coordination number and the values of the force constants.

  3. Cascadability properties of MZI-SOA-based all-optical 3R regenerators for RZ-DPSK signals.

    PubMed

    Kise, Tomofumi; Nguyen, Kimchau N; Garcia, John M; Poulsen, Henrik N; Blumenthal, Daniel J

    2011-05-09

    We experimentally demonstrate 50 cascaded all-optical 3R regenerators over a 1,000 km transmission distance for 10-Gb/s return-to-zero differential phase-shift keying (RZ-DPSK) signals. The regenerator consists of integrated Mach-Zehnder interferometer (MZI) semiconductor optical amplifier (SOA) based wavelength converters. Regenerative properties and tolerance to pattern dependent effects have been studied in terms of Q-factor measurement, and error free operation with input OSNR of 20 dB/0.1 nm has also been demonstrated.

  4. Faraday effect in Sn2P2S6 crystals.

    PubMed

    Krupych, Oleh; Adamenko, Dmytro; Mys, Oksana; Grabar, Aleksandr; Vlokh, Rostyslav

    2008-11-10

    We have revealed a large Faraday rotation in tin thiohypodiphosphate (Sn(2)P(2)S(6)) crystals, which makes this material promising for magneto-optics. The effective Faraday tensor component and the Verdet constant for the direction of the optic axis have been determined by measuring the pure Faraday rotation in Sn(2)P(2)S(6) crystals with both the single-ray and small-angular polarimetric methods at the normal conditions and a wavelength of 632.8 nm. The effective Verdet constant is found to be equal to 115 rad/T x m.

  5. Effects of H2S on molten carbonate fuel cells

    NASA Astrophysics Data System (ADS)

    Remick, R. J.; Anderson, G. L.

    1984-04-01

    The results of a literature survey conducted by the Institute of Gas Technology (IGT) under Phase 1 of a multiphase program to investigate and identify the mechanism(s) responsible for molten carbonate fuel cell (MCFC) performance losses when operating on sulfur containing gases are discussed. The objective was twofold: to review the reported data on the interaction of H2S with nickel containing materials; and to review reported investigations on the specific effects of H2S on the electrochemical oxidation of H2 in MCFC. The ultimate goal of the literature review was to determine the poisoning mechanism.

  6. The pressure-induced phase transition studies of In2S3 and In2S3:Ce nanoparticles

    NASA Astrophysics Data System (ADS)

    Yao, Binbin; Zhu, Hongyang; Wang, Shuangming; Wang, Pan; Zhang, Mingzhe

    2014-02-01

    A novel method, gas-liquid phase chemical deposition is developed to prepare In2S3 and In2S3:Ce nanoparticles. The structural, morphology and composition feature of these two nanoparticles is studied by XRD, HRTEM, and XPS. In situ high-pressure synchrotron X-ray diffraction studies were carried out by using a diamond-anvil cell. The doping does not influence the tetragonal-to-cubic phase transition path while results in a lower phase transition pressure of In2S3:Ce nanoparticles (4.3 GPa) than that of In2S3 nanoparticles (7.1 GPa). The bulk moduli of tetragonal phases are B0=87.1±4.3 GPa and B0=55.6±4.1 GPa, respectively. The distinct high-pressure behaviors can be explained in term of the doped ions, causing lattice distortion and reducing structural stability of the In2S3 nanoparticles and further accelerating the phase transition.

  7. Radiative lifetimes of the 2s2p2(4P) metastable levels of N III

    NASA Technical Reports Server (NTRS)

    Fang, Z.; Kwong, Victor H. S.; Parkinson, W. H.

    1993-01-01

    The radiative decay rates of N III 175 nm intersystem lines were measured in the laboratory by recording the time dependence of photon intensities emitted as the 2s2p2(4P) metastable term of N(2+) ions decay to the 2s22p(2P0) ground term. A cylindrical radio frequency ion trap was used to store the electron impact-produced N(2+) ions. The radiative decay signals were analyzed by multiexponential least-squares fits to the data. The measured radiative decay rates to the ground term are 1019(+/- 64)/s for 4P sub 1/2, 74.5(+/- 5.4)/s for 4P sub 3/2, and 308( +/- 22)/s for 4P sub 5/2. Comparisons of the measured values with theoretical values are presented.

  8. Inhibition of β-catenin signaling involved in the biological activities of a lignan E2S isolated from Carya cathayensis fruits.

    PubMed

    Xia, Xichun; Bi, Xiuli; Wu, Wei; Mou, Yanhua; Hou, Yue; Zhang, Kaiqing; Zhao, Yuqing

    2013-11-01

    Carya cathayensis is a fruit-bearing plant that belongs to the Juglandaceae family and is widely distributed throughout the world. It possesses various important biological activities. We have previously isolated an antitumor compound from the shell of C. cathayensis fruits and named it E2S ((E)-3-[(2S,3R)-2,3-dihydro-2-(4'-hydroxy-3'-methoxyphenyl)-3-hydroxymethyl-7-methoxy-1-benzo[b]furan-5-yl]-2-propenal). In this study, we investigated the antitumor activity of E2S against various human colorectal cancer cell lines (HCT116, HT29, SW480, LoVo). The results showed that E2S could significantly inhibit the growth of cancer cells in a dose-dependent manner, as well as disrupt the progression of the cell cycle. Mechanistic study revealed that E2S could decrease the protein levels of β-catenin and its downstream targets (such as c-myc, a key transcriptional target of β-catenin) in the cells. In addition, it also significantly suppressed β-catenin/TCF transcriptional activity. Taken together, the results suggested that E2S might partially exert an antiproliferative effect on human colorectal cancer cells by targeting β-catenin signaling, a finding that might potentially translate into a chemotherapeutic strategy for the treatment of cancer. It might also have implications for cancer prevention strategies.

  9. Structural, electromagnetic and thermoelectric properties of Bi4O4S3 superconductor

    NASA Astrophysics Data System (ADS)

    Srivastava, P.; Shruti; Patnaik, S.

    2014-05-01

    We report on the synthesis and extensive characterization of the layered Bi4O4S3 superconductor. This is the optimally doped sample with Tc ˜ 5.3 K out of a series of Bi6O4S4(SO4)1-x samples synthesized by solid state reaction. The series was prepared towards establishing a phase diagram of the transition temperature as a function of carrier concentration. The crystal structure for Bi4O4S3 shows a different Bi-S-Bi bond angle as compared to that for the parent phase. Scanning electron microscopy images show a platelet-like morphology for Bi4O4S3, signifying the layered structure. While the parent compound is found to be semiconducting, the electrical resistivity of Bi4O4S3 exhibits a T2 dependence in a small temperature range between 25 and 50 K. The typical dome structure for variation of Tc with dopant concentration is not observed. From the magneto-transport data Hc2 for Bi4O4S3 is estimated to be ˜2.75 T using the WHH approximation and the corresponding coherence length is ˜110 Å. Support for multi-band signatures is not seen from the magneto-resistance data. The rf susceptibility data fits well for an S-wave isotropic gap with a gap value higher than the BCS strong coupling limit. Hall measurements confirm the dominance of electronic transport with a charge carrier density of 4.405 × 1019 cm-3 at 10 K. The experimental value of the Seebeck coefficient at 35 K is well in accord with the calculated value deduced by using the density of charge carriers from Hall experiments. The Sommerfeld constant γ is estimated to be 1.113 mJ K-2 mol-1. Evidence for thermally activated flux flow is observed and the pinning potential is found to scale as B-0.3 for B < 0.1 T and B-1.99 for B > 0.1 T.

  10. The decomposition of H 2S on Ni(110)

    NASA Astrophysics Data System (ADS)

    Huntley, D. R.

    1990-12-01

    Adsorbed H 2S decomposes on Ni(110) to form primarily surface S and H for coverages of less than 0.5 ML. The hydrogen evolves in two separate TPD peaks, characteristic of hydrogen recombination and desorption from the clean surface and from regions perturbed by chemisorbed sulfur. XPS and HREELS indicate the presence of SH and possibly H 2S groups on the surface at 110 K. The XPS data indicates that for coverages less than about 0.5 ML, the concentration of molecular H 2S is small, but it is difficult to asess the coverage of SH groups. However, all of the molecular species decompose prior to hydrogen desorption (for high coverage, 180 K). Physisorbed H 2S is observed on the surface for coverages greater than about 0.5 ML. The sulfur Auger lineshape was observed to be a function of both coverage and temperature. The changes in the lineshape were attributed to perturbations in local bonding interactions between the S and the Ni surface, perhaps involving some change in either bonding sites or distances but not involving SH bond scission. The decomposition reaction was modeled using a bond order conservation method which successfully reproduced the experimental results.

  11. 2S Albumin Storage Proteins: What Makes them Food Allergens?

    PubMed Central

    Moreno, F. Javier; Clemente, Alfonso

    2008-01-01

    2S albumin storage proteins are becoming of increasing interest in nutritional and clinical studies as they have been reported as major food allergens in seeds of many mono- and di-cotyledonous plants. This review describes the main biochemical, structural and functional properties of these proteins thought to play a role in determining their potential allergenicity. 2S albumins are considered to sensitize directly via the gastrointestinal tract (GIT). The high stability of their intrinsic protein structure, dominated by a well-conserved skeleton of cysteine residues, to the harsh conditions present in the GIT suggests that these proteins are able to cross the gut mucosal barrier to sensitize the mucosal immune system and/or elicit an allergic response. The flexible and solvent-exposed hypervariable region of these proteins is immunodominant and has the ability to bind IgE from allergic patients´ sera. Several linear IgE-binding epitopes of 2S albumins spanning this region have been described to play a major role in allergenicity; the role of conformational epitopes of these proteins in food allergy is far from being understood and need to be investigated. Finally, the interaction of these proteins with other components of the food matrix might influence the absorption rates of immunologically reactive 2S albumins but also in their immune response. PMID:18949071

  12. Exome sequencing identifies a novel mutation in PIK3R1 as the cause of SHORT syndrome

    PubMed Central

    2014-01-01

    Background SHORT syndrome is a rare autosomal dominant condition whose name is the acronym of short stature, hyperextensibility of joints, ocular depression, Rieger anomaly and teething delay (MIM 269880). Additionally, the patients usually present a low birth weight and height, lipodystrophy, delayed bone age, hernias, low body mass index and a progeroid appearance. Case presentation In this study, we used whole-exome sequencing approaches in two patients with clinical features of SHORT syndrome. We report the finding of a novel mutation in PIK3R1 (c.1929_1933delTGGCA; p.Asp643Aspfs*8), as well as a recurrent mutation c.1945C > T (p.Arg649Trp) in this gene. Conclusions We found a novel frameshift mutation in PIK3R1 (c.1929_1933delTGGCA; p.Asp643Aspfs*8) which consists of a deletion right before the site of substrate recognition. As a consequence, the protein lacks the position that interacts with the phosphotyrosine residue of the substrate, resulting in the development of SHORT syndrome. PMID:24886349

  13. The Effects of T4 and A3/R Bacteriophages on Differentiation of Human Myeloid Dendritic Cells

    PubMed Central

    Bocian, Katarzyna; Borysowski, Jan; Zarzycki, Michał; Pacek, Magdalena; Weber-Dąbrowska, Beata; Machcińska, Maja; Korczak-Kowalska, Grażyna; Górski, Andrzej

    2016-01-01

    Bacteriophages (phages) are viruses of bacteria. Here we evaluated the effects of T4 and A3/R bacteriophages, as well as phage-generated bacterial lysates, on differentiation of human myeloid dendritic cells (DCs) from monocytes. Neither of the phages significantly reduced the expression of markers associated with differentiation of DCs and their role in the activation of T cells (CD40, CD80, CD83, CD86, CD1c, CD11c, MHC II, PD-L1, PD-L2, TLR2, TLR4, and CCR7) and phagocytosis receptors (CD64 and DEC-205). By contrast, bacterial lysate of T4 phage significantly decreased the percentages of DEC-205- and CD1c-positive cells. The percentage of DEC-205-positive cells was also significantly reduced in DCs differentiated in the presence of lysate of A3/R phage. Thus while bacteriophages do not substantially affect differentiation of DCs, some products of phage-induced lysis of bacterial cells may influence the differentiation and potentially also some functions of DCs. Our results have important implications for phage therapy of bacterial infections because during infections monocytes recruited to the site of inflammation are an important source of inflammatory DCs. PMID:27582733

  14. H2S during circulatory shock: Some unresolved questions

    PubMed Central

    McCook, Oscar; Radermacher, Peter; Volani, Chiara; Asfar, Pierre; Ignatius, Anita; Kemmler, Julia; Möller, Peter; Szabó, Csaba; Whiteman, Matthew; Wood, Mark E.; Wang, Rui; Georgieff, Michael; Wachter, Ulrich

    2014-01-01

    Numerous papers have been published on the role of H2S during circulatory shock. Consequently, knowledge about vascular sulfide concentrations may assume major importance, in particular in the context of “acute on chronic disease”, i.e., during circulatory shock in animals with pre-existing chronic disease. This review addresses the questions i) of the “real” sulfide levels during circulatory shock, and, ii) to which extent injury and pre-existing co-morbidity may affect the expression of H2S producing enzymes under these conditions. In the literature there is a huge range on sulfide blood levels during circulatory shock, in part as a result of the different analytical methods used, but also due to the variable of the models and species studied. Clearly, some of the very high levels reported should be questioned in the context of the well-known H2S toxicity. As long as “real” sulfide levels during circulatory shock are unknown and/or undetectable “on line” due to the lack of appropriate techniques, it appears to be premature to correlate the measured blood levels of hydrogen sulfide with the severity of shock or the H2S therapy-related biological outcomes. The available data on the tissue expression of the H2S-releasing enzymes during circulatory shock suggest that a “constitutive” CSE expression may play a crucial role of for the maintenance of organ function, at least in the kidney. The data also indicate that increased CBS and CSE expression, in particular in the lung and the liver, represents an adaptive response to stress states. PMID:24650697

  15. Stability studies of As4S4 nanosuspension prepared by wet milling in Poloxamer 407.

    PubMed

    Bujňáková, Zdenka; Dutková, Erika; Baláž, Matej; Turianicová, Erika; Baláž, Peter

    2015-01-15

    In this paper the stability of the arsenic sulfide (As4S4) nanosuspension prepared by wet milling in a circulation mill in the environment of copolymer Poloxamer 407 was studied. The obtained As4S4 particles in nanosuspension were of ∼ 100 nm in size. The influence of temperature and UV irradiation on the changes in physical and/or chemical properties was followed. Long-term stability was observed via particle size distribution and zeta potential measurements. Influence of UV irradiation was studied via UV-vis spectroscopy (UV-vis), photoluminicsence (PL) technique and Fourier transform infrared spectroscopy (FTIR) measurements. The best stability of the nanosuspension (24 weeks) was achieved when stored at 4°C and in the dark.

  16. Measurement of the branching fraction of Gamma(4S) --> B0B0.

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges-Pous, E; Palano, A; Pappagallo, M; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Chevalier, N; Cottingham, W N; Kelly, M P; Cuhadar-Donszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bondioli, M; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Weinstein, A J R; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, Sh; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Ruddick, W O; Smith, J G; Ulmer, K A; Zhang, J; Chen, A; Eckhart, E A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q; Spaan, B; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Maly, E; Nogowski, R; Otto, S; Petzold, A; Schott, G; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Bernard, D; Bonneaud, G R; Grenier, P; Schrenk, S; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Marks, J; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Arnaud, N; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Petersen, T C; Pierini, M; Plaszczynski, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Parry, R J; Payne, D J; Touramanis, C; Cormack, C M; Di Lodovico, F; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hodgkinson, M C; Lafferty, G D; Naisbit, M T; Williams, J C; Chen, C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Taylor, F; Yamamoto, R K; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Brau, J; Frey, R; Igonkina, O; Lu, M; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; John, M J J; Leruste, Ph; Malclès, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Biasini, M; Covarelli, R; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Simi, G; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Tehrani, F Safai; Voena, C; Christ, S; Schröder, H; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Gopal, G P; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; Graziani, G; de Monchenault, G Hamel; Kozanecki, W; Legendre, M; London, G W; Mayer, B; Vasseur, G; Yèche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Abe, T; Allen, M; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Claus, R; Convery, M R; Cristinziani, M; Dingfelder, J C; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Mohapatra, A K; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Soha, A; Stelzer, J; Strube, J; Su, D; Sullivan, M K; Thompson, J; Va'vra, J; Wagner, S R; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Ahmed, M; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Ricca, G Della; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Martinez-Vidal, F; Panvini, R S; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Jackson, P D; Kowalewski, R; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mellado, B; Mihalyi, A; Pan, Y; Prepost, R; Tan, P; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2005-07-22

    We report the first measurement of the branching fraction f(00) for Gamma(4S) --> B(0)B(0). The data sample consists of 81.7 fb(-1) collected at the Gamma(4S) resonance with the BABAR detector at the SLAC PEP-II asymmetric-energy e(+)e(-) storage ring. Using partial reconstruction of the decay B(0) --> D(*+) l(-)nu(l) in which only the charged lepton and the soft pion from the decay D(*+) --> D(0)pi(+) are reconstructed, we obtain f(00) = 0.487 +/- 0.010(stat) +/- 0.008(syst). Our result does not depend on the branching fractions of B(0) --> D(*+)l(-)nu(l) and D(*+) --> D(0)pi(+) decays, on the ratio of the charged and neutral B meson lifetimes, nor on the assumption of isospin symmetry.

  17. Strong Decay of ϕ (1 s), ϒ(4s) and Σ±*in Magnetic Field

    NASA Astrophysics Data System (ADS)

    Filip, Peter

    2016-01-01

    The influence of static magnetic field on decays ϕ (1020) KK̅, ϒ (4s)→ BB̅, and Σ±* → Ʌπ± is discussed. In particular, we estimate how much the ratio of decay widths Γ(K+K-)/Γ(K0K0) and Γ(B+B-)/Γ(B0B0) can be modified by magnetic fields of strength B ≈ 1014 T created in relativistic collisions of heavy nuclei at LHC and RHIC colliders. Due to interaction of charged K and B mesons with the magnetic field, branching ratios for K+K- and B+B- decays of ϕ (1020) and ϒ (4s) completely closed. We study also the influence of magnetic field on strong decay Σ±* (1385) →Ʌ + π±.

  18. Effective, high-yielding, and stereospecific total synthesis of D-erythro-(2R,3S)-sphingosine from D-ribo-(2S,3S,4R)-phytosphingosine.

    PubMed

    van den Berg, Richard J B H N; Korevaar, Cornelius G N; Overkleeft, Herman S; van der Marel, Gijsbert A; van Boom, Jacques H

    2004-08-20

    The synthesis of naturally occurring D-erythro-(2R,3S,4E)-sphingosine from commercially available D-ribo-(2S,3S,4R)-phytosphingosine is described. The key step in the reaction sequence comprises TMSI/DBN promoted regio- and stereoselective oxirane opening of intermediate 2-phenyl-4-(S)-[(1S,2S)-1,2-epoxyhexadecyl]-1,3-oxazoline followed by the in situ trans-elimination of 2-phenyl-4-(S)-[(1S,2R)-1,2-dideoxy-2-iodo-1-trimethylsilyloxyhexadecyl]-1,3-oxazoline.

  19. Multiferroicity and skyrmions carrying electric polarization in GaV4S8

    PubMed Central

    Ruff, Eugen; Widmann, Sebastian; Lunkenheimer, Peter; Tsurkan, Vladimir; Bordács, Sandor; Kézsmárki, Istvan; Loidl, Alois

    2015-01-01

    Skyrmions are whirl-like topological spin objects with high potential for future magnetic data storage. A fundamental question that is relevant to both basic research and application is whether ferroelectric (FE) polarization can be associated with skyrmions’ magnetic texture and whether these objects can be manipulated by electric fields. We study the interplay between magnetism and electric polarization in the lacunar spinel GaV4S8, which undergoes a structural transition associated with orbital ordering at 44 K and reveals a complex magnetic phase diagram below 13 K, including ferromagnetic, cycloidal, and Néel-type skyrmion lattice (SkL) phases. We found that the orbitally ordered phase of GaV4S8 is FE with a sizable polarization of ~1 μC/cm2. Moreover, we observed spin-driven excess polarizations in all magnetic phases; hence, GaV4S8 hosts three different multiferroic phases with coexisting polar and magnetic order. These include the SkL phase, where we predict a strong spatial modulation of FE polarization close to the skyrmion cores. By taking into account the crystal symmetry and spin patterns of the magnetically ordered phases, we identify exchange striction as the main microscopic mechanism behind the spin-driven FE polarization in each multiferroic phase. Because GaV4S8 is unique among known SkL host materials owing to its polar crystal structure and the observed strong magnetoelectric effect, this study is an important step toward the nondissipative electric field control of skyrmions. PMID:26702441

  20. Escherichia coli biotin synthase produces selenobiotin. Further evidence of the involvement of the [2Fe-2S]2+ cluster in the sulfur insertion step.

    PubMed

    Tse Sum Bui, Bernadette; Mattioli, Tony A; Florentin, Dominique; Bolbach, Gérard; Marquet, Andrée

    2006-03-21

    Biotin synthase, a member of the "radical SAM" family, catalyzes the final step of the biotin biosynthetic pathway, namely, the insertion of a sulfur atom into dethiobiotin. The as-isolated enzyme contains a [2Fe-2S](2+) cluster, but the active enzyme requires an additional [4Fe-4S](2+) cluster, which is formed in the presence of Fe(NH(4))(2)(SO(4))(2) and Na(2)S in the in vitro assay. The role of the [4Fe-4S](2+) cluster is to mediate the electron transfer to SAM, while the [2Fe-2S](2+) cluster is involved in the sulfur insertion step. To investigate the selenium version of the reaction, we have depleted the enzyme of its iron and sulfur and reconstituted the resulting apoprotein with FeCl(3) and Na(2)Se to yield a [2Fe-2Se](2+) cluster. This enzyme was assayed in vitro with Na(2)Se in place of Na(2)S to enable the formation of a [4Fe-4Se](2+) cluster. Selenobiotin was produced, but the activity was lower than that of the as-isolated [2Fe-2S](2+) enzyme in the presence of Na(2)S. The [2Fe-2Se](2+) enzyme was additionally assayed with Na(2)S, to reconstitute a [4Fe-4S](2+) cluster, in case the latter was more efficient than a [4Fe-4Se](2+) cluster for the electron transfer. Indeed, the activity was improved, but in that case, a mixture of biotin and selenobiotin was produced. This was unexpected if one considers the [2Fe-2S](2+) center as the sulfur source (either as the ultimate donor or via another intermediate), unless some exchange of the chalcogenide has taken place in the cluster. This latter point was seen in the resonance Raman spectrum of the reacted enzyme which clearly indicated the presence of both the [2Fe-2Se](2+) and [2Fe-2S](2+) clusters. No exchange was observed in the absence of reaction. These observations bring supplementary proof that the [2Fe-2S](2+) cluster is implicated in the sulfur insertion step.

  1. Evaluation for 4S core nuclear design method through integration of benchmark data

    SciTech Connect

    Nagata, A.; Tsuboi, Y.; Moriki, Y.; Kawashima, M.

    2012-07-01

    The 4S is a sodium-cooled small fast reactor which is reflector-controlled for operation through core lifetime about 30 years. The nuclear design method has been selected to treat neutron leakage with high accuracy. It consists of a continuous-energy Monte Carlo code, discrete ordinate transport codes and JENDL-3.3. These two types of neutronic analysis codes are used for the design in a complementary manner. The accuracy of the codes has been evaluated by analysis of benchmark critical experiments and the experimental reactor data. The measured data used for the evaluation is critical experimental data of the FCA XXIII as a physics mockup assembly of the 4S core, FCA XVI, FCA XIX, ZPR, and data of experimental reactor JOYO MK-1. Evaluated characteristics are criticality, reflector reactivity worth, power distribution, absorber reactivity worth, and sodium void worth. A multi-component bias method was applied, especially to improve the accuracy of sodium void reactivity worth. As the result, it has been confirmed that the 4S core nuclear design method provides good accuracy, and typical bias factors and their uncertainties are determined. (authors)

  2. Functional analysis of human CNGA3 mutations associated with colour blindness suggests impaired surface expression of channel mutants A3(R427C) and A3(R563C).

    PubMed

    Koeppen, Katja; Reuter, Peggy; Kohl, Susanne; Baumann, Britta; Ladewig, Thomas; Wissinger, Bernd

    2008-05-01

    Mutations in the CNGA3 gene have been associated with complete and incomplete forms of total colour blindness (achromatopsia), a disorder characterized by reduced visual acuity, lack of colour discrimination, photophobia and nystagmus. CNGA3 encodes the A-subunit of the cone photoreceptor cyclic nucleotide-gated (CNG) channel, an essential component of the phototransduction cascade. Here we report the identification of three new CNGA3 mutations in patients with achromatopsia. To assess the pathogenicity of these newly identified and four previously reported mutations, mutant CNGA3 channels were heterologously expressed in a human embryonic kidney cell line (HEK293 cells) and functionally analysed using calcium imaging. Channels with the mutations R427C and R563C showed a response in imaging experiments and were subsequently characterized in-depth with the patch-clamp technique. The mutant channels were analysed as homooligomers and also as heterooligomers with the wild-type B-subunit present in native channels. Overall, cyclic guanosine monophosphate (cGMP) maximum currents of mutant channels were profoundly reduced in homo- and heteromers. Treatment with the chemical chaperone glycerol effectively increased macroscopic currents, presumably by enhancing surface expression of mutant channels as confirmed by immunocytochemistry. These results suggest decreased channel density in the cell membrane due to impaired folding or trafficking of the channel protein as the main pathogenic effect of the mutations R427C and R563C. Moreover, A3(R427C) homomers showed distinctly increased cGMP and cyclic adenosine monophosphate (cAMP) sensitivities as well as cAMP fractional currents that were raised to over 90% of cGMP maximum currents. Co-expression of A3(R427C) with the B3 subunit compensated for most of these aberrant properties, apart from the reduced cGMP maximum currents.

  3. Bethe-Salpeter wave functions of ηc(2 S ) and ψ (2 S ) states from full lattice QCD

    NASA Astrophysics Data System (ADS)

    Nochi, Kazuki; Kawanai, Taichi; Sasaki, Shoichi

    2016-12-01

    We discuss the internal structure of radially excited charmonium mesons based on the equal-time and Coulomb gauge Bethe-Salpeter (BS) amplitudes, which are obtained in lattice QCD. Our simulations are performed with a relativistic heavy-quark action for the charm quark on the (2 +1 )-flavor PACS-CS gauge configurations at the lightest pion mass, Mπ=156 (7 ) MeV . The variational method is applied to the study of the optimal charmonium operators for ground and first excited states of S -wave charmonia. We successfully calculate the BS wave functions of ηc(2 S ) and ψ (2 S ) states, as well as ηc(1 S ) and J /ψ states, and then estimate the root-mean-square radii of both the 1 S and 2 S charmonium states. We also examine whether a series of the BS wave functions from the ground state to excited states can be described by a single set of the spin-independent and spin-dependent interquark potentials with a unique quark mass. It is found that the quark kinetic mass and both the central and the spin-spin charmonium potentials, determined from the 2 S wave functions, fairly agree with the ones from the 1 S wave functions. This strongly supports the validity of the potential description for the charmonium system—at least, below the open-charm threshold.

  4. Preparation of 3R- and 3S-methyl isomers of the myocardial imaging agent 15-(p-IODOPHENYL)-3-methylpentadecanoic acid ({open_quotes}BMIPP{close_quotes})

    SciTech Connect

    Lin, Q. |; Luo, J.; Mokler, F.

    1996-10-01

    Iodine-123-labeled racemic BMIPP is used for clinical evaluation of heart disease. To evaluate the expected importance of configuration of the asymmetric C-3 center, we have synthesized the 3R-isomer. 6-Phenylhexanoyl chloride was condensed with thiophene (Friedel-Crafts), followed by Wolff-Kishner reduction and subsequent acylation with the ethyl-3-R-methylglutaroyl chloride, Wolff-Kishner reduction and Raney-Ni ring opening. Para Thallation (TTFA)/KI provided 3R-BMIPP, m.p. 51-52{degrees}C, [{alpha}{sub D}] = +0.74{degrees}. The diastereomeric amide mixture was prepared by reaction of racemic 3-R,S-BMIPP with (S)-(-)-{alpha}-methylbenzylamine. Chromatographic separation and HCl hydrolysis (at 175{degrees}C) provided the 3R- and 3S- (m.p. 45-46{degrees}C, [{alpha}{sub D}] = -1.67{degrees}) BMIPP isomers. The more polar amide (m.p. 93-94{degrees}C) was identical with the amide from the synthetic 3R-BMIPP (m.p., HPLC, NMR). Availability of the 3R- and 3S-BMIPP isomers will permit preparation of the radioiodinated isomers and animal evaluation to determine the effects of the methyl group configuration on myocardial uptake and metabolism.

  5. Electron spin-lattice relaxation of the (4Fe-4S) ferredoxin from B. stearothermophilus. Comparison with other iron proteins

    NASA Astrophysics Data System (ADS)

    Bertrand, Patrick; Gayda, Jean-Pierre; Rao, K. Krishna

    1982-05-01

    The temperature dependence of the electron spin-lattice relaxation time T1 of the (4Fe-4S) ferredoxin from Bacillus stearothermophilus is studied in the range 1.2 to 40 K. This dependence is similar to that observed for the (2Fe-2S) ferredoxin from Spirulina maxima and can be interpreted with the same relaxation processes [J.P. Gayda, P. Bertrand, A. Deville, C. More, G. Roger, J.F. Gibson, and R. Cammack, Biochim. Biophys. Acta 581, 15 (1979)]. In particular, between 4 and 15 K, the data are well fitted by a second-order Raman process involving three-dimensional phonons, with a Debye temperature of about 60 K (45 cm-1). This would give an estimation of the highest frequency of the vibrations which can propagate through the three-dimensional proteinic medium. In the highest temperature range (T≳30 K) the results are interpreted with an Orbach process involving an excited level of energy 120 cm-1. This process could be induced by the localized vibrations of the active site. Finally, these results are compared to those recently reported for some hemoproteins [H.J. Stapleton, J.P. Allen, C.P. Flynn, D.G. Stinson, and S.R. Kurtz, Phys. Rev. Lett. 45, 1456 (1980)]. Below 15 K, the temperature dependence of T1 for these samples is similar to that observed for the iron-sulfur proteins and may be interpreted in the same way. Our interpretation is compared to the fractal model proposed by Stapleton et al.

  6. Optical Properties of In2S3 Thin Films

    NASA Astrophysics Data System (ADS)

    Bodnar, I. V.; Polubok, V. A.

    2014-11-01

    Laser deposition on substrates at temperatures of 480, 610, and 720 K has been used to produce films of the compound In2S3. Single crystals of this compound grown by the Bridgeman-Stockbarger method are used as targets. The composition is determined by x-ray spectral analysis and the structure of the resulting crystals and films is determined by x-ray methods. Both the crystals and the films crystallize into a tetragonal spinel structure. Transmission spectra in the region of the intrinsic absorption edge are used to determine the width of the band gap and the refractive index of the In2S3 films. The band gap width is found to increase as the substrate temperature is raised.

  7. Hot gas, regenerative, supported H.sub.2 S sorbents

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E. (Inventor); Sharma, Pramod K. (Inventor)

    1993-01-01

    Efficient, regenerable sorbents for removal of H.sub.2 S from moderately high temperature (usually 200.degree. C.-550.degree.C.) gas streams comprise a porous, high surface area aluminosilicate support, suitably a zeolite, and most preferably a sodium deficient zeolite containing 1 to 20 weight percent of binary metal oxides. The binary oxides are a mixture of a Group VB or VIB metal oxide with a Group IB, IIB or VIII metal oxide such as V-Zn-O, V-Cu-O, Cu-Mo-O, Zn-Mo-O or Fe-Mo-O contained in the support. The sorbent effectively removes H.sub.2 S from the host gas stream in high efficiency and can be repetitively regenerated at least 10 times without loss of activity.

  8. Magic Wavelength for the Hydrogen 1S-2S Transition

    NASA Astrophysics Data System (ADS)

    Kawasaki, Akio

    2016-05-01

    The state of the art precision measurement of the transition frequencies of neutral atoms is performed with atoms trapped by the magic wavelength optical lattice that cancels the ac Stark shift of the transitions. Trapping with magic wavelength lattice is also expected to improve the precision of the hydrogen 1S-2S transition frequency, which so far has been measured only with the atomic beam. In this talk, I discuss the magic wavelength for the hydrogen 1S-2S transition, and the possibility of implementing the optical lattice trapping for hydrogen. Optical trapping of hydrogen also opens the way to perform magnetic field free spectroscopy of antihydrogen for the test of CPT theorem.

  9. Measurement of the muonium 1S-2S transition frequency

    SciTech Connect

    Jungmann, K.; Baird, P.E.G.; Barr, J.R.M.; Berkeland, D.; Boshier, M.G.; Braun, B.; Eaton, G.H.; Ferguson, A.I.; Geerds, H.; Hughes, V.W.; Maas, F.; Matthias, B.E.; Matousek, P.; Persaud, M.; zu Putlitz, G.; Reinhard, I.; Riis, E.; Sandars, P.G.H.; Schwarz, W.; Toner, W.T.; Towrie, M.; Willmann, L.; Woodle, K.A.; Woodman, G.

    1995-04-01

    Resonant ionization spectroscopy has been employed for measuring the 1{sup 2}{ital S}{sub 1/2}{minus}2{sup 2}{ital S}{sub 1/2} frequency difference in the hydrogen-like muonium atom to 2 455 529 002(33)(46) MHz. The 1S-2S two-photon transition was induced Doppler-free using two counter-propagating laser beams. The 2S state was photo-ionized by a third photon from the same laser field. The measurement agrees with QED theory within two standard deviations. The mass of the positive muon can be extracted from the isotope shifts in this transition to hydrogen and deuterium to 105.658 80(29)(43) MeV/c{sup 2}. {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}

  10. Crystal structure of (+)-methyl (E)-3-[(2S,4S,5R)-2-amino-5-hy-droxy-meth-yl-2-tri-chloro-methyl-1,3-dioxolan-4-yl]-2-methyl-prop-2-enoate.

    PubMed

    Oishi, Takeshi; Yasushima, Daichi; Yuasa, Kihiro; Sato, Takaaki; Chida, Noritaka

    2016-03-01

    In the title compound, C10H14Cl3NO5, the five-membered dioxolane ring adopts an envelope conformation. The C atom at the flap, which is bonded to the hy-droxy-methyl substituent, deviates from the mean plane of other ring atoms by 0.357 (5) Å. There are two intra-molecular hydrogen bonds (O-H⋯N and N-H⋯O) between the hy-droxy and amino groups, so that O- and N-bound H atoms involved in these hydrogen bonds are each disordered with equal occupancies of 0.50. The methyl 2-methyl-prop-2-enoate substituent also shows a disordered structure over two sets of sites with refined occupancies of 0.482 (5) and 0.518 (5). In the crystal, mol-ecules are connected into a dimer by an O-H⋯O hydrogen bond. The dimers are further linked by N-H⋯O, C-H⋯N and C-H⋯O inter-actions, extending a sheet structure parallel to ([Formula: see text]01).

  11. Coriolis coupling effects in O(+)(4S) + H2(X1Σg(+)) → OH (+)(X3Σ(–)) + H(2S) reaction and its isotopic variants: exact time-dependent quantum scattering study.

    PubMed

    Xu, Wenwu; Li, Wenliang; Lv, Shuangjiang; Zhai, Hongsheng; Duan, Zhixin; Zhang, Peiyu

    2012-11-15

    The time-dependent wave packet quantum method taking into account the Coriolis coupling (CC) has been employed to investigate the dynamics of O(+) + H(2)/D(2)/HD (v(i) = 0, j(i) = 0) reactions based on an accurate potential energy surface [ Martínez et al. J. Chem. Phys. 2004 , 120 , 4705 ]. Through the comparison between the results with and without CC, the pronounced CC effects have been revealed in the title reactions. Moreover, the calculated results with the CC method can well reproduce the data of close-coupling hyperspherical (CCH) exact quantum method. The calculations demonstrate that the CC effects play an important role in the O(+) + H(2) system.

  12. The NASA Dual-Frequency Dual-Polarized Doppler Radar (D3R) System for Gpm Ground Validation

    NASA Astrophysics Data System (ADS)

    Chandra, C. V.; Schwaller, M.; Vega, M.; Misra, K. V.; Carswell, J.; Nguyen, C.; Petersen, W. A.

    2010-12-01

    The successful introduction of single-frequency (Ku-Band: 13.8 GHz) weather radar onboard the Tropical Rain Measuring Mission (TRMM) satellite in 1997 facilitated improved understanding of the spatial distribution, variability, intensity of rainfall and its role in climate. However, the mission’s inherent limitations of spatiotemporal coverage and limited sensitivity to frozen precipitation hindered knowledge of the role of precipitation in climate and hydrological cycles. The Global Precipitation Measurement (GPM) mission will attempt to advance further the goal of making global scale precipitation observations by deploying the next generation of satellite-borne weather radars. The GPM satellite will carry a Ka-Ku band Dual-frequency Precipitation Radar (DPR) that can make measurements of parameters directly related to the microphysics of precipitation (such as raindrop size distribution). While the Ku-band radar is an updated version of the TRMM precipitation radar, the Ka-band radar would provide higher sensitivity which can prove useful in the measurement of snow and light rain. The Dual-Frequency Dual-Polarized Doppler Radar (D3R) is a ground validation radar, proposed as a part of the GPM Ground Validation (GV) program, to enable both physical validation support in terms of understanding the microphysical description of the observations as well as algorithm retrieval implications. This paper provides a scientific and technical overview of the D3R system as well as major challenges. Following the success of TRMM, the GPM mission has embarked on a dual-frequency approach at Ku- and Ka-band for characterizing precipitation. While extensive ground radar observations of precipitation are available at S- and C- band, such measurements do not exist at Ku- and Ka-band. Ground radar measurements enjoy the advantage of coincident microphysical observations available to interpret radar signatures. Another major advantage of the ground radar observations is the ability

  13. Study of structural, electronic and elastic properties of RPd{sub 3} (R = Lu and Sc) compounds

    SciTech Connect

    Thakur, Veena Pagare, Gitanjali Chouhan, S. S.; Sanyal, S. P.

    2014-04-24

    The structural, electronic and elastic properties of nonmagnetic RPd{sub 3} (R = Lu and Sc) compounds, which crystallize in AuCu{sub 3}-type structure, are studied using first principles density functional theory based on full potential linearized augmented plane wave (FP-LAPW) method. The calculations are carried out within the PBE-GGA and WC-GGA for the exchange correlation potential. Our calculated ground state properties such as lattice constant (a0), bulk modulus (B) and its pressure derivative (B’) are in good agreement with the experimental results. We first time predict the elastic constants for these compounds using different approximations of GGA. These RPd{sup 3} compounds are found to be ductile in nature in accordance with Pugh’s criteria. The computed electronic band structures and density of states show metallic character of these compounds.

  14. Spin exchange interactions in hexagonal manganites RMnO3 (R = Tb, Dy, Ho, Er) epitaxial thin films

    NASA Astrophysics Data System (ADS)

    Chen, Xiang-Bai; Thi Minh Hien, Nguyen; Lee, D.; Jang, S.-Y.; Noh, T. W.; Yang, In-Sang

    2011-08-01

    We present the results of an optical method of quantitatively estimating the spin exchange interactions in hexagonal manganites RMnO3 (R = Tb, Dy, Ho, Er) epitaxial thin films. The two in-plane (a-b plane) spin exchange integrals J1 (intratrimer Mn-Mn interaction) and J2 (intertrimer Mn-Mn interaction) are deduced from the magnon scattering peak wavenumbers. We found that J2 decreases systematically when the R ionic radius increases, while J1 is nearly independent of R ionic radius, contrary to the expectation in single crystals. We show that the R dependence of J1 could be understood in terms of the stress in the thin films. Our result indicates that the stress has stronger effect on the atomic displacement of the intratrimer Mn-Mn distance than the intertrimer Mn-Mn distance.

  15. Differing Evolutionary Histories of the ACTN3*R577X Polymorphism among the Major Human Geographic Groups

    PubMed Central

    Amorim, Carlos Eduardo G.; Acuña-Alonzo, Victor; Salzano, Francisco M.; Bortolini, Maria Cátira; Hünemeier, Tábita

    2015-01-01

    It has been proposed that the functional ACTN3*R577X polymorphism might have evolved due to selection in Eurasian human populations. To test this possibility we surveyed all available population-based data for this polymorphism and performed a comprehensive evolutionary analysis of its genetic diversity, in order to assess the action of adaptive and random mechanisms on its variation across human geographical distribution. The derived 577X allele increases in frequency with distance from Africa, reaching the highest frequencies on the American continent. Positive selection, detected by an extended haplotype homozygosisty test, was consistent only with the Eurasian data, but simulations with neutral models could not fully explain the results found in the American continent. It is possible that particularities of Native American population structure could be responsible for the observed allele frequencies, which would have resulted from a complex interaction between selective and random factors. PMID:25706920

  16. Photoexcited Carrier Dynamics of In2S3 Thin Films.

    PubMed

    McCarthy, Robert F; Schaller, Richard D; Gosztola, David J; Wiederrecht, Gary P; Martinson, Alex B F

    2015-07-02

    Indium sulfide (In2S3) is a promising absorber base for substitutionally doped intermediate band photovoltaics (IBPV); however, the dynamics of charge carriers traversing the electronic density of states that determine the optical and electronic response of thin films under stimuli have yet to be explored. The kinetics of photophysical processes in In2S3 grown by oxygen-free atomic layer deposition are deduced from photoconductivity, photoluminescence (PL), and transient absorption spectroscopy. We develop a map of excited-state dynamics for polycrystalline thin films including a secondary conduction band ∼2.1 eV above the first, plus sulfur vacancy and indium interstitial defect levels resulting in long-lived (∼100 ns) transients. Band-edge recombination produces PL and stimulated emission, which both intensify and red-shift as deposition temperature and grain size increase. The effect of rapid conduction band electron relaxation (<30 ps) and deep defect levels on IBPV employing In2S3-based absorbers is finally considered.

  17. H2S mediated thermal and photochemical methane activation

    PubMed Central

    Baltrusaitis, Jonas; de Graaf, Coen; Broer, Ria; Patterson, Eric

    2013-01-01

    Sustainable, low temperature methods of natural gas activation are critical in addressing current and foreseeable energy and hydrocarbon feedstock needs. Large portions of natural gas resources are still too expensive to process due to their high content of hydrogen sulfide gas (H2S) in mixture with methane, CH4, altogether deemed as sub-quality or “sour” gas. We propose a unique method for activating this “sour” gas to form a mixture of sulfur-containing hydrocarbon intermediates, CH3SH and CH3SCH3, and an energy carrier, such as H2. For this purpose, we computationally investigated H2S mediated methane activation to form a reactive CH3SH species via direct photolysis of sub-quality natural gas. Photoexcitation of hydrogen sulfide in the CH4+H2S complex results in a barrier-less relaxation via a conical intersection to form a ground state CH3SH+H2 complex. The resulting CH3SH can further be heterogeneously coupled over acidic catalysts to form higher hydrocarbons while the H2 can be used as a fuel. This process is very different from a conventional thermal or radical-based processes and can be driven photolytically at low temperatures, with enhanced controllability over the process conditions currently used in industrial oxidative natural gas activation. Finally, the proposed process is CO2 neutral, as opposed to the currently industrially used methane steam reforming (SMR). PMID:24150813

  18. H2S-mediated thermal and photochemical methane activation.

    PubMed

    Baltrusaitis, Jonas; de Graaf, Coen; Broer, Ria; Patterson, Eric V

    2013-12-02

    Sustainable, low-temperature methods for natural gas activation are critical in addressing current and foreseeable energy and hydrocarbon feedstock needs. Large portions of natural gas resources are still too expensive to process due to their high content of hydrogen sulfide gas (H2S) mixed with methane, deemed altogether as sub-quality or "sour" gas. We propose a unique method of activation to form a mixture of sulfur-containing hydrocarbon intermediates, CH3SH and CH3SCH3 , and an energy carrier such as H2. For this purpose, we investigated the H2S-mediated methane activation to form a reactive CH3SH species by means of direct photolysis of sub-quality natural gas. Photoexcitation of hydrogen sulfide in the CH4 + H2S complex resulted in a barrierless relaxation by a conical intersection to form a ground-state CH3SH + H2 complex. The resulting CH3SH could further be coupled over acidic catalysts to form higher hydrocarbons, and the resulting H2 used as a fuel. This process is very different from conventional thermal or radical-based processes and can be driven photolytically at low temperatures, with enhanced control over the conditions currently used in industrial oxidative natural gas activation. Finally, the proposed process is CO2 neutral, as opposed to the current industrial steam methane reforming (SMR).

  19. ACTN3 R577X and other polymorphisms are not associated with elite endurance athlete status in the Genathlete study.

    PubMed

    Döring, Frank E; Onur, Simone; Geisen, Ulf; Boulay, Marcel R; Pérusse, Louis; Rankinen, Tuomo; Rauramaa, Rainer; Wolfahrt, Bernd; Bouchard, C

    2010-10-01

    Homozygosity for a premature stop codon at amino acid position 577 in the alpha-actinin-3 (ACTN3) gene leads to α-actinin-3 deficiency. This genotype is observed in approximately 18% of Caucasians. The ACTN3 R577X polymorphism has been previously associated with indicators of physical performance in several, but not all, studies. We examined the prevalence of R577X (rs1815739) and two additional haplotype tagging single nucleotide polymorphisms (htSNPs) of the ACTN3 gene (rs1791690 and rs2275998) in the Genathlete study comprising 316 male elite endurance athletes (VO2max 79.0+3.5 ml · kg(-1) · min(-1); mean +/- s) from North America, Finland, and Germany and 304 sedentary controls (VO2max 40.1+7.0 ml · kg(-1) · min(-1) matched by country of origin. The distribution of genotype and allele frequencies between the two groups was tested by Pearson chi-square and/or Fischer exact test. The prevalence of the 577X homozygote genotype was similar in endurance athletes and controls (20% and 17.5%, respectively). The resulting odds ratio for endurance performance in 577X homozygotes compared with 577R-allele carriers was 1.24 (95%CI 0.82-1.87, P = 0.3). The genotype distribution of the two htSNPs and haplotype frequencies did not differ significantly between athletes and controls. In conclusion, our findings indicate that ACTN3 R577X and other SNPs in ACTN3 are not genetic determinants of endurance performance in Caucasian males.

  20. Effects of an H3R Antagonist on the Animal Model of Autism Induced by Prenatal Exposure to Valproic Acid

    PubMed Central

    Baronio, Diego; Castro, Kamila; Gonchoroski, Taylor; de Melo, Gabriela Mueller; Nunes, Gustavo Della Flora; Bambini-Junior, Victorio; Gottfried, Carmem; Riesgo, Rudimar

    2015-01-01

    Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders primarily characterized by impaired social interaction and communication, and by restricted repetitive behaviors and interests. Ligands of histamine receptor 3 (H3R) are considered potential therapeutic agents for the treatment of different brain disorders and cognitive impairments. Considering this, the aim of the present study is to evaluate the actions of ciproxifan (CPX), an H3R antagonist, on the animal model of autism induced by prenatal exposure to valproic acid (VPA). Swiss mice were prenatally exposed to VPA on embryonic day 11 and assessed for social behavior, nociceptive threshold and repetitive behavior at 50 days of life. The treatment with CPX (3 mg/kg) or saline was administered 30 minutes before each behavioral test. The VPA group presented lower sociability index compared to VPA animals that were treated with CPX. Compared to the Control group, VPA animals presented a significantly higher nociceptive threshold, and treatment with CPX was not able to modify this parameter. In the marble burying test, the number of marbles buried by VPA animals was consistent with markedly repetitive behavior. VPA animals that received CPX buried a reduced amount of marbles. In summary, we report that an acute dose of CPX is able to attenuate sociability deficits and stereotypies present in the VPA model of autism. Our findings have the potential to help the investigations of both the molecular underpinnings of ASD and of possible treatments to ameliorate the ASD symptomatology, although more research is still necessary to corroborate and expand this initial data. PMID:25560049

  1. Boar spermatozoa successfully predict mitochondrial modes of toxicity: implications for drug toxicity testing and the 3R principles.

    PubMed

    Vicente-Carrillo, A; Edebert, I; Garside, H; Cotgreave, I; Rigler, R; Loitto, V; Magnusson, K E; Rodríguez-Martínez, H

    2015-04-01

    Replacement of animal testing by in vitro methods (3-R principles) requires validation of suitable cell models, preferably obtained non-invasively, defying traditional use of explants. Ejaculated spermatozoa are highly dependent on mitochondrial production and consumption of ATP for their metabolism, including motility display, thus becoming a suitable model for capturing multiple modes of action of drugs and other chemicals acting via mitochondrial disturbance. In this study, a hypothesis was tested that the boar spermatozoon is a suitable cell type for toxicity assessment, providing a protocol for 3R-replacement of animals for research and drug-testing. Boar sperm kinetics was challenged with a wide variety of known frank mito-toxic chemicals with previously shown mitochondrial effects, using a semi-automated motility analyser allied with real-time fluorescent probing of mitochondrial potential (MitoTracker & JC-1). Output of this sperm assay (obtained after 30 min) was compared to cell viability (ATP-content, data obtained after 24-48 h) of a hepatome-cell line (HepG2). Results of compound effects significantly correlated (P<0.01) for all sperm variables and for most variables in (HepG2). Dose-dependent decreases of relative ATP content in HepG2 cells correlated to sperm speed (r=0.559) and proportions of motile (r=0.55) or progressively motile (r=0.53) spermatozoa. The significance of the study relies on the objectivity of computerized testing of sperm motility inhibition which is comparable albeit of faster output than somatic cell culture models. Sperm suspensions, easily and painlessly obtained from breeding boars, are confirmed as suitable biosensors for preclinical toxicology screening and ranking of lead compounds in the drug development processes.

  2. Effects of an H3R antagonist on the animal model of autism induced by prenatal exposure to valproic acid.

    PubMed

    Baronio, Diego; Castro, Kamila; Gonchoroski, Taylor; de Melo, Gabriela Mueller; Nunes, Gustavo Della Flora; Bambini-Junior, Victorio; Gottfried, Carmem; Riesgo, Rudimar

    2015-01-01

    Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders primarily characterized by impaired social interaction and communication, and by restricted repetitive behaviors and interests. Ligands of histamine receptor 3 (H3R) are considered potential therapeutic agents for the treatment of different brain disorders and cognitive impairments. Considering this, the aim of the present study is to evaluate the actions of ciproxifan (CPX), an H3R antagonist, on the animal model of autism induced by prenatal exposure to valproic acid (VPA). Swiss mice were prenatally exposed to VPA on embryonic day 11 and assessed for social behavior, nociceptive threshold and repetitive behavior at 50 days of life. The treatment with CPX (3 mg/kg) or saline was administered 30 minutes before each behavioral test. The VPA group presented lower sociability index compared to VPA animals that were treated with CPX. Compared to the Control group, VPA animals presented a significantly higher nociceptive threshold, and treatment with CPX was not able to modify this parameter. In the marble burying test, the number of marbles buried by VPA animals was consistent with markedly repetitive behavior. VPA animals that received CPX buried a reduced amount of marbles. In summary, we report that an acute dose of CPX is able to attenuate sociability deficits and stereotypies present in the VPA model of autism. Our findings have the potential to help the investigations of both the molecular underpinnings of ASD and of possible treatments to ameliorate the ASD symptomatology, although more research is still necessary to corroborate and expand this initial data.

  3. A novel splicing mutation in the SLC9A3R1 gene in tumors from ovarian cancer patients.

    PubMed

    Kreimann, Erica Lorena; Ratajska, Magdalena; Kuzniacka, Alina; Demacopulo, Brenda; Stukan, Maciej; Limon, Janusz

    2015-12-01

    The aim of the present study was to investigate novel molecular markers that could improve the diagnosis of ovarian cancer patients or be of predictive value. The sequence of the sodium-hydrogen antiporter 3 regulator 1 (SLC9A3R1) gene that codes for the PDZ2 motif of the Na(+)/H(+) exchanger regulatory factor 1 (NHERF1) protein was analyzed. Changes in migration and cell transformation, and alterations of growth factor signaling pathways have been described in cells lacking endogenous NHERF1 or expressing an isoform lacking the function of the PDZ2 domain. Exons 2 and 3, together with flanking intronic sequences of the SLC9A3R1 gene, were amplified and bi-directionally sequenced in 31 primary tumor samples from epithelial ovarian cancer patients. In total, 3 different previously undescribed mutations were detected in 8 out of 31 serous adenocarcinoma tumor samples (25.8%). Bioinformatics analysis predicted a significant effect in the splicing process as a result of the mutations that could disrupt the NHERF1 PDZ2 domain. Point mutations in consensus splicing recognition are a major cause of the splicing defects that are found in several diseases, including cancer. It has previously been shown that a lack of exon 2 and disruption of the PDZ2 domain contribute to cell transformation and leads to modifications in the physiological regulation of the conformational state of NHERF1. Further studies in bigger groups of ovarian cancer patients will determine the importance of this mutation in disease progression and patient survival.

  4. Mechanism of N2 dissociation and kinetics of N(4S) atoms in pure nitrogen plasma

    NASA Astrophysics Data System (ADS)

    Volynets, A. V.; Lopaev, D. V.; Popov, N. A.

    2016-10-01

    This work deals with kinetics of the ground state nitrogen atoms N(4S) and N2 dissociation mechanism in pure nitrogen plasma. The experiment was carried out in positive column of DC glow discharge at a range of parameters p = 5 - 50 Torr, J = 20 - 100 mA. The use of axial homogeneous glow discharge allowed considering N(4S) balance for spatially uniform conditions controlled by only two terms: source (characterized by effective production rate k diss eff ) and loss (characterized by effective loss time τN l oss ). Analysis of these parameters gains considerably better understanding of N2 dissociation mechanism in pure nitrogen plasma that was the main goal of the given work. So N/N2 dissociation rate as function of discharge parameters was obtained using two independent emission optical methods: actinometry on Ar atoms and N2 2+ band emission decay at discharge modulation. Measurements of N/N2 radial profiles allowed estimating N atom surface loss probability γN l oss and correspondingly τN l oss . It was revealed that γN l oss depends on N(4S) concentration and thereby discharge conditions through the sorption balance of physisorbed N atoms. Simple phenomenological model taking into account basic surface processes provides γN l oss data in good agreement with experiment. Finally, k diss eff was obtained as function of reduced electric field E/N and it was shown that even EEDF self-consistently calculated with accounting for N2 vibrational excitation is unable to provide observed values of k diss eff . Reasons of that fact are discussed in detail.

  5. Large structural changes upon protonation of Fe4S4 clusters: the consequences for reactivity.

    PubMed

    Dance, Ian; Henderson, Richard A

    2014-11-21

    Density functional calculations reveal that protonation of a μ3-S in [Fe4S4X4](2-) clusters (X = halide, thiolate, phenoxide) results in the breaking of one S-Fe bond (to >3 Å, from 2.3 Å). This creates a doubly-bridging SH ligand (μ3-SH is not stable), and a unique three-coordinated planar Fe atom. The under-coordination of this unique Fe atom is the basis of revised mechanisms for the acid-catalysed ligand substitution reactions in which substitution of X by PhS occurs at the unique Fe site by an indirect pathway involving initial displacement of X by acetonitrile (solvent), followed by displacement of coordinated acetonitrile by PhSH. When X = Cl or Br the rate of attack by PhSH is slower than the dissociation of X(-), and is the rate-determining step; in contrast, when X = SEt, SBu(t) or OPh the rate of dissociation of XH is slower than attack by PhSH and is rate-determining for these clusters. A full and consistent interpretation of all kinetic data is presented including new explanations of many of the kinetic observations on the acid-catalysed substitution reactions of [Fe4S4X4](2-) clusters. The proposed mechanisms are supported by density functional calculations of the structures of intermediates, and simulations of some of the steps. These findings are expected to have widespread ramifications for the reaction chemistry of both natural and synthetic clusters with the {Fe4S4} core.

  6. Nanostructured all-solid-state supercapacitor based on Li2S-P2S5 glass-ceramic electrolyte

    NASA Astrophysics Data System (ADS)

    Francisco, Brian E.; Jones, Christina M.; Lee, Se-Hee; Stoldt, Conrad R.

    2012-03-01

    While today's lithium-ion batteries offer acceptable energy storage capability, they lack the ability to be cycled repeatedly more than a couple thousand times. Electrochemical capacitors, i.e., supercapacitors, are being developed whose lifetimes exceed 1 × 106 cycles and power densities surpass those of batteries by several times. Here, we present an all-solid-state supercapacitor using a Li2S-P2S5 glass-ceramic electrolyte as both separator and ion conductor. Three device architectures are examined including two with nanostructured electrodes which incorporate multi-walled carbon nanotubes (MWCNTs). Cyclic voltammograms and electrochemical impedance measurements demonstrate that these devices develop reversible double layer capacitance, and a maximum of 7.75 F/g is achieved in the device constructed by mechanically mixing the nanostructured electrodes. Electrochemical impedance spectroscopy explains non-idealities observed when MWCNTs are incorporated in the electrode layers.

  7. Removal of H{sub 2}S by spray-calcined calcium acetate

    SciTech Connect

    Nimmo, W.; Agnew, J.; Hampartsoumian, E.; Jones, J.M.

    1999-08-01

    The effectiveness of wet-spraying calcium acetate as an alternative to limestone and dolomite for the desulfurization of flue gases (in particular, H{sub 2}S removal from coal gas) has been investigated by experimental studies using drop tube (DTR) and fixed-bed flow reactors (FBR). Calcium acetate solution was spray-calcined in the DTR at temperatures of 1073 and 1323 K. At the lower temperature, conversions approaching 80% were found at the longest residence time studied, 0.8 s. On the other hand, the higher temperature condition initially showed a much greater rate of calcination, indicated by greater conversion at shorter residence times, but was then followed by a much slower rate beyond 0.4 s. The final degree of conversion was in the region of 70%. Batches of spray-calcined calcium acetate (SCA), limestone, and dolomite, prepared in the DTR at 1323 K, to 70% conversion, were sulfided in the FBR at temperatures of 873 and 1173 K to assess their relative sulfur capture reactivities. Significantly higher conversions were achieved by the spray-calcined material, especially at the higher FBR temperature (1173 K) where a difference in conversion of more than 40% was observed. The physical structure of the particles formed from wet-spray calcination were determined by electron microscopy and showed highly porous cenospheres with large internal voids and an outside surface characterized by blowholes of between 1 and 10 {micro}m in diameter. As a consequence, the available surface area for reaction with H{sub 2}S is greater than with limestone or dolomite, producing a 4-fold difference in the level of particle conversion.

  8. A new approach: Li2S-P2S5 thin-films prepared by thermal evaporation as solid electrolytes

    NASA Astrophysics Data System (ADS)

    Woo, Sung Pil; Kakati, Nitul; Kim, In Yea; Lee, Seok Hee; Yoon, Young Soo

    2016-08-01

    Li2S-P2S5 thin-film solid electrolytes are synthesized by using room-temperature thermal evaporation for use as lithium-ion conductors for all-solid-state Li-ion batteries. The local structures of 75.51Li2S:24.49P2S5 and 77.64Li2S:22.36P2S5 prepared in this way have hetero units that facilitate lithium-ion mobility. The lithium-ion conductivity at room temperature for the 77.64Li2S:22.36P2S5 thin-film (4.0 × 10-6 S cm-1) is higher than that for the 75.51Li2S:24.49P2S5 thin-film (1.2 × 10-6 S cm-1). The increased ion conductivity in the 77.64Li2S:22.36P2S5 film is due to the additional local P2S7 4- structure that forms a glassy state during the thermal evaporation process. The local structure can lead to a high mobility of Li+ ions in the Li2S-P2S5 system due to the non-bridging sulfide ions. Lithium-ion-conducting thin-films prepared by using thermal evaporation, as reported in this study, are promising solid electrolytes.

  9. Tumor-specific delivery of BSH-3R for boron neutron capture therapy and positron emission tomography imaging in a mouse brain tumor model.

    PubMed

    Iguchi, Yoshiya; Michiue, Hiroyuki; Kitamatsu, Mizuki; Hayashi, Yuri; Takenaka, Fumiaki; Nishiki, Tei-Ichi; Matsui, Hideki

    2015-07-01

    Glioblastoma, a malignant brain tumor with poor disease outcomes, is managed in modern medicine by multimodality therapy. Boron neutron capture therapy (BNCT) is an encouraging treatment under clinical investigation. In malignant cells, BNCT consists of two major factors: neutron radiation and boron uptake. To increase boron uptake in cells, we created a mercapto-closo-undecahydrododecaborate ([B12HnSH](2-)2Na(+), BSH) fused with a short arginine peptide (1R, 2R, 3R) and checked cellular uptake in vitro and in vivo. In a mouse brain tumor model, only BSH with at least three arginine domains could penetrate cell membranes of glioma cells in vitro and in vivo. Furthermore, to monitor the pharmacokinetic properties of these agents in vivo, we fused BSH and BSH-3R with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA); DOTA is a metal chelating agent for labeling positron emission tomography (PET) probe with (64)Cu. We administered BSH-DOTA-(64)Cu and BSH-3R-DOTA-(64)Cu to the tumor model through a mouse tail vein and determined the drugs' pharmacokinetics by PET imaging. BSH-3R showed a high uptake in the tumor area on PET imaging. We concluded that BSH-3R is the ideal boron compound for clinical use during BNCT and that in developing this compound for clinical use, the BSH-3R PET probe is essential for pharmacokinetic imaging.

  10. NH{sub 3}/H{sub 2}S advances

    SciTech Connect

    Gupta, R.P.; Gangwal, S.K.; Krishnan, G.N.; Hung, S.L.

    1993-08-01

    The following preliminary conclusions can be derived from the above-mentioned experimental results: (1) HTSR-1, a nickel-based catalyst has a high activity for NH{sub 3} decomposition at 725{degree}C in simulated coal gas streams under low H{sub 2}S levels. (2) HTSR-1 when mixed with a desulfurization sorbent such as zinc titanate could decompose NH{sub 3} effectively until the removal of H{sub 2}S by zinc titanate decreases. (3) HTSR-1 continues to exhibit an activity for NH{sub 3} decomposition even after exposure to zinc titanate regeneration conditions. (4) MoS{sub 2} is also a catalyst for the decomposition of NH{sub 3}. However, its surface area needs to be maintained by addition of suitable stabilizing agents for sustained activity. Sorbent-catalyst samples of zinc titanate doped with cobalt-molybdenum were prepared by first crushing and sieving pellets of zinc titanate sorbents (L-3774M). The zinc titanate powders were then placed into an aqueous solution having the desired total amount of molybdenum (in the form of molybdic acid). The water was then dried and the powder heated and calcined. To add cobalt to the Mo-coated powder, the powder was then placed into a solution of cobalt nitrate containing the appropriate amount of the cobalt precursor followed by drying and calcination. The sorbent-catalyst samples were then activated (presulfided) by introducing H{sub 2}S in a controlled reducing environment. Samples of nickel-molybdenum-zinc titanate were prepared by using nickel nitrate instead of cobalt nitrate in the described procedure.

  11. AC electrical properties of FeIn2S4

    NASA Astrophysics Data System (ADS)

    Niftiev, N. N.; Tagiev, O. B.; Muradov, M. B.; Mamedov, F. M.

    2012-04-01

    The frequency and temperature dependences of the ac capacitance and resistivity of FeIn2S4 semiconductors are studied. Resonances are observed at certain temperatures in the frequency range (2.5-5.0) × 105 Hz. The permittivity of the crystals and the activation energy of charge carriers are determined. It is found that electrical conduction in the given temperature interval is governed by an activation mechanism. The activation energy is frequency-dependent, because the relaxation time of barrier layers decreases with rising frequency.

  12. Identification of two [4Fe-4S]-cluster-containing hydro-lyases from Pyrococcus furiosus.

    PubMed

    van Vugt-Lussenburg, Barbara M A; van der Weel, Laura; Hagen, Wilfred R; Hagedoorn, Peter-Leon

    2009-09-01

    The hyperthermophilic archaeon Pyrococcus furiosus is a strict anaerobe. It is therefore not expected to use the oxidative tricarboxylic acid (TCA) cycle for energy transduction. Nonetheless, its genome encodes more putative TCA cycle enzymes than the closely related Pyrococcus horikoshii and Pyrococcus abyssi, including an aconitase (PF0201). Furthermore, a two-subunit fumarase (PF1755 and PF1754) is encoded on the Pyr. furiosus genome. In the present study, these three genes were heterologously overexpressed in Escherichia coli to enable characterization of the enzymes. PF1755 and PF1754 were shown to form a [4Fe-4S]-cluster-containing heterodimeric enzyme, able to catalyse the reversible hydratation of fumarate. The aconitase PF0201 also contained an Fe-S cluster, and catalysed the conversion from citrate to isocitrate. The fumarase belongs to the class of two-subunit, [4Fe-4S]-cluster-containing fumarate hydratases exemplified by MmcBC from Pelotomaculum thermopropionicum; the aconitase belongs to the aconitase A family. Aconitase probably plays a role in amino acid synthesis when the organism grows on carbohydrates. However, the function of the seemingly metabolically isolated fumarase in Pyr. furiosus has yet to be established.

  13. iPhone 4s and iPhone 5s Imaging of the Eye

    PubMed Central

    Jalil, Maaz; Ferenczy, Sandor R.; Shields, Carol L.

    2017-01-01

    Background/Aims To evaluate the technical feasibility of a consumer-grade cellular iPhone camera as an ocular imaging device compared to existing ophthalmic imaging equipment for documentation purposes. Methods A comparison of iPhone 4s and 5s images was made with external facial images (macrophotography) using Nikon cameras, slit-lamp images (microphotography) using Zeiss photo slit-lamp camera, and fundus images (fundus photography) using RetCam II. Results In an analysis of six consecutive patients with ophthalmic conditions, both iPhones achieved documentation of external findings (macrophotography) using standard camera modality, tap to focus, and built-in flash. Both iPhones achieved documentation of anterior segment findings (microphotography) during slit-lamp examination through oculars. Both iPhones achieved fundus imaging using standard video modality with continuous iPhone illumination through an ophthalmic lens. Comparison to standard ophthalmic cameras, macrophotography and microphotography were excellent. In comparison to RetCam fundus photography, iPhone fundus photography revealed smaller field and was technically more difficult to obtain, but the quality was nearly similar to RetCam. Conclusions iPhone versions 4s and 5s can provide excellent ophthalmic macrophotography and microphotography and adequate fundus photography. We believe that iPhone imaging could be most useful in settings where expensive, complicated, and cumbersome imaging equipment is unavailable. PMID:28275604

  14. Core level electron binding energies of realgar (As{sub 4}S{sub 4})

    SciTech Connect

    Pratt, A.R.; Nesbitt, H.W.

    2000-04-01

    XPS broad scans and high-resolution narrow-region spectra were collected from fresh realgar (As{sub 4}S{sub 4}) surfaces to measure core level S and As binding energies. Reasonably accurate As and S concentrations were determined from XPS broad scans using peak areas and manufacturer supplied sensitivity factors. High resolution S(2p) and As(3d) narrow region spectra were comprised of photoelectron emissions indicative of As and S in intermediate oxidation states akin to binding energies of As and S polymeric species. S(2p) spectra were interpreted using only S contributions expected from the bulk mineral matrix and showed that S was not greatly affected by surface state phenomena. This was attributed to breakage of intermolecular van der Waals bonds rather than covalent interatomic bonds. As(3d) spectra were found to contain two contributions one from As atoms in As{sub 4}S{sub 4} molecules in the bulk mineral matrix and another possibly from As atoms in molecules situated at the surface.

  15. Large scale free energy calculations for blind predictions of protein-ligand binding: the D3R Grand Challenge 2015

    NASA Astrophysics Data System (ADS)

    Deng, Nanjie; Flynn, William F.; Xia, Junchao; Vijayan, R. S. K.; Zhang, Baofeng; He, Peng; Mentes, Ahmet; Gallicchio, Emilio; Levy, Ronald M.

    2016-09-01

    We describe binding free energy calculations in the D3R Grand Challenge 2015 for blind prediction of the binding affinities of 180 ligands to Hsp90. The present D3R challenge was built around experimental datasets involving Heat shock protein (Hsp) 90, an ATP-dependent molecular chaperone which is an important anticancer drug target. The Hsp90 ATP binding site is known to be a challenging target for accurate calculations of ligand binding affinities because of the ligand-dependent conformational changes in the binding site, the presence of ordered waters and the broad chemical diversity of ligands that can bind at this site. Our primary focus here is to distinguish binders from nonbinders. Large scale absolute binding free energy calculations that cover over 3000 protein-ligand complexes were performed using the BEDAM method starting from docked structures generated by Glide docking. Although the ligand dataset in this study resembles an intermediate to late stage lead optimization project while the BEDAM method is mainly developed for early stage virtual screening of hit molecules, the BEDAM binding free energy scoring has resulted in a moderate enrichment of ligand screening against this challenging drug target. Results show that, using a statistical mechanics based free energy method like BEDAM starting from docked poses offers better enrichment than classical docking scoring functions and rescoring methods like Prime MM-GBSA for the Hsp90 data set in this blind challenge. Importantly, among the three methods tested here, only the mean value of the BEDAM binding free energy scores is able to separate the large group of binders from the small group of nonbinders with a gap of 2.4 kcal/mol. None of the three methods that we have tested provided accurate ranking of the affinities of the 147 active compounds. We discuss the possible sources of errors in the binding free energy calculations. The study suggests that BEDAM can be used strategically to discriminate

  16. Large scale free energy calculations for blind predictions of protein-ligand binding: the D3R Grand Challenge 2015.

    PubMed

    Deng, Nanjie; Flynn, William F; Xia, Junchao; Vijayan, R S K; Zhang, Baofeng; He, Peng; Mentes, Ahmet; Gallicchio, Emilio; Levy, Ronald M

    2016-09-01

    We describe binding free energy calculations in the D3R Grand Challenge 2015 for blind prediction of the binding affinities of 180 ligands to Hsp90. The present D3R challenge was built around experimental datasets involving Heat shock protein (Hsp) 90, an ATP-dependent molecular chaperone which is an important anticancer drug target. The Hsp90 ATP binding site is known to be a challenging target for accurate calculations of ligand binding affinities because of the ligand-dependent conformational changes in the binding site, the presence of ordered waters and the broad chemical diversity of ligands that can bind at this site. Our primary focus here is to distinguish binders from nonbinders. Large scale absolute binding free energy calculations that cover over 3000 protein-ligand complexes were performed using the BEDAM method starting from docked structures generated by Glide docking. Although the ligand dataset in this study resembles an intermediate to late stage lead optimization project while the BEDAM method is mainly developed for early stage virtual screening of hit molecules, the BEDAM binding free energy scoring has resulted in a moderate enrichment of ligand screening against this challenging drug target. Results show that, using a statistical mechanics based free energy method like BEDAM starting from docked poses offers better enrichment than classical docking scoring functions and rescoring methods like Prime MM-GBSA for the Hsp90 data set in this blind challenge. Importantly, among the three methods tested here, only the mean value of the BEDAM binding free energy scores is able to separate the large group of binders from the small group of nonbinders with a gap of 2.4 kcal/mol. None of the three methods that we have tested provided accurate ranking of the affinities of the 147 active compounds. We discuss the possible sources of errors in the binding free energy calculations. The study suggests that BEDAM can be used strategically to discriminate

  17. Vacuum annealing temperature on spray In2S3 layers

    NASA Astrophysics Data System (ADS)

    Bouguila, Nourredine; Timoumi, Abdelmajid; Bouzouita, Hassen

    2014-02-01

    Indium sulfide In2S3 thick films are deposited on glass substrates using spray technique over the optimum conditions experiments (Ts = 340 °C, S/In = 2). The films are polycrystalline and have thickness of about 1.8 μm. These films are annealed in a vacuum sealed pyrex tubes (10-5 torr). Physico-chemical characterizations by SEM observation, X-ray diffraction and EDX analysis are undertaked on these films. This treatment has improved crystallinity of samples. It has allowed thus to stabilize β and γ varieties of In2S3 material. In2O3 and In6S7 phases have appeared with very weak intensities at high temperatures. The best structure quality are obtained at 300 °C for the optimum annealed temperature (Ts = 340 °C, S/In = 2), for which samples are constituted in dominance by γ phase oriented preferentially towards (1 0 2). The grain size is 42 nm of this phase. Chemical composition of such films has changed relatively to non-treated film but it seems not be affected by treatment temperature. Atomic molar ratio S/In is obtained for 0.9. Optical study shows that these layers are transparent in the visible and optical direct band gap increases as function of annealed temperature.

  18. Open Standards and Technologies in the S2S Framework

    NASA Astrophysics Data System (ADS)

    Maffei, A. R.; Rozell, E. A.; West, P.; Zednik, S.; Fox, P. A.

    2011-12-01

    The S2S Search Interface Framework provides tools and services to build customized user interfaces. It also serves as a focal point for repository managers to develop science data services and reusable components for search interfaces. The framework has been used to design a faceted browsing platform for web services, including OpenSearch and SAWSDL. This exemplar faceted browsing platform has been applied in our development of search interfaces for 1) an international open government dataset catalog and 2) a metadata catalog for biological and chemical oceanography. S2S was designed from the ground up using open standards and technologies. The framework was initially created to develop "data dashboard" interfaces on top of OpenSearch services, but has been generalized to support web services and standards with semantic annotation capabilities. We apply OWL, a W3C standard for ontologies on the Web, to create a vocabulary for the description of framework metadata. Our faceted browsing platform is heavily focused on the use of jQuery; we have created reusable user interface "widgets" that leverage OpenLayers and MapServer technology in geospatial selection and visualization, which can be used in this and future platforms. The use of open standards and technologies has enabled rapid iterations over software development lifecycles, and has kept the framework agile as new use cases and ideas have emerged.

  19. Effects of H2S on molten carbonate fuel cells

    NASA Astrophysics Data System (ADS)

    Remick, R. J.

    1985-06-01

    Phase 2 work was directed toward determination of the impact of H2S contaminants upon the ability of nickel-10% chromium anodes to catalyze the steam reforming reaction. Small amounts of three hydrocarbons representative of three homologous series were added to the fuel. These series were the paraffin series with methane as its representative, the olefin series with ethylene and the aromatics with toluene. Results indicated that the nickel-10% chromium anode had little catalytic activity toward the steam reforming of methane, but the steam reform did have 70% of the ethylene and about 30% of the toluene. The addition of 5 ppM hydrogen sulfide to the fuel totally poisoned all steam reforming activity. Phase 3 work addressed the impact on cell performance of SO2 in the oxidant gases. The cell was operated for 200 hours on clean fuel and oxidant. After baseline data had been collected, the cell was switched to an oxidant supply that contained 2 ppM of SO2. After 170 hours of operation on contaminated oxidant, no SO2 could be detected in the oxidant exhaust although 200 ppM of H2S were present in the fuel exhaust steam.

  20. Magnetic Ordering in FeSc2 S4

    NASA Astrophysics Data System (ADS)

    Plumb, K. W.; Morey, J. R.; Ruff, J. P. C.; Rodriguez-Rivera, J. A.; McQueen, T. M.; Koohpayeh, S. M.; Broholm, C. L.

    FeSc2S4 is a cubic spinel where orbitally active Fe2+ ions occupy the A-site diamond sublattice. Despite a high spin (S=2) state and Curie Weiss temperature of 45 K thermodynamic measurements show no indication of a phase transition and the material has been proposed as a unique example of a spin-orbital liquid. This ground state might arise from competition between on site spin-orbit coupling and Kugel-Khomskii exchange. We report neutron scattering measurements on polycrystalline samples of FeSc2S4 which bring this picture into question. They reveal a previously unreported magnetically ordered state below 11 K. No structural distortions are visible with neutron or x-ray scattering. The effect of hydrostatic pressure on the magnetic excitation spectrum was also explored and found to be minimal. This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Material Sciences and Engineering, under Grant No. DEFG02-08ER46544.

  1. Upconversion luminescence properties of Y2O2S:Er3+@Y2O2S:Yb3+,Tm3+ core-shell nanoparticles prepared via homogeneous co-precipitation

    NASA Astrophysics Data System (ADS)

    Tian, Ying; Lu, Fei; Xing, Mingming; Ran, Jincheng; Fu, Yao; Peng, Yong; Luo, Xixian

    2017-02-01

    The Y2O2S:Er3+@Y2O2S:Yb3+,Tm3+ core-shell upconversion (UC) nanoparticles with average diameter of 95 nm were synthesized by the homogeneous co-precipitation method combining with the solid-gas sulfidation route. The increases of nanocrystaline size after the shell coating was observed both in the X-ray diffraction (XRD) and transmission electron microscope (TEM) measurements. This indicates the composition homogeneity core-shell Y2O2S nanocrystals. Meanwhile, the luminescence of both the Er3+ and Tm3+ ions are realized for the first time in the novel core-shell Y2O2S:Er3+@Y2O2S:Yb3+,Tm3+ nanoparticles under the excitations of both 980 and 1550 nm. When excited by a 980 nm laser diode, the Y2O2S:Er3+@Y2O2S:Yb3+,Tm3+ phosphor exhibits blue (≈475 nm), green (≈548 nm) and red (≈670 nm) emissions in the visible region, which correspond to the 1G4 → 3H6 transition of Tm3+ions, 4S3/2, 2H11/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of Er3+ ions, respectively. The very strong emission at the near infrared (NIR) region is mainly due to the 3H4 → 3H6 transition of Tm3+ ions. The emission from both of Er3+ and Tm3+ ions under 980 nm excitation reveals the energy transfers of Yb3+ → Tm3+ within the shell layer and Yb3+ → Er3+ between the shell and the core. When pumping at 1550 nm, although only Er3+ ions can efficiently absorb the excitation energy, the strong UC emissions from Tm3+ ions were also observed. This is owing to the energy transfer between the core and the shell through Er3+ → Yb3+ → Tm3+ ions.

  2. Imidazoline derivative templated synthesis of broccoli-like Bi2S3 and its electrocatalysis towards the direct electrochemistry of hemoglobin.

    PubMed

    Chen, Xiaoqian; Wang, Qingxiang; Wang, Liheng; Gao, Feng; Wang, Wei; Hu, Zhengshui

    2015-04-15

    A broccoli-like bismuth sulfide (bBi2S3) was synthesized via a solvothermal method using a self-made imidazoline derivative of 2-undecyl-1-dithioureido-ethyl-imidazoline as the soft template. The morphology and chemical constitution of the product were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Electrochemical characterization experiments show that the bBi2S3 has the higher specific surface area and standard heterogeneous electron transfer rate constant than the rod-like Bi2S3 (rBi2S3). Hemoglobin (Hb) was then chosen as a protein model to investigate the electrocatalytic property of the synthesized bBi2S3. The results show that Hb entrapped in the composite film of chitosan and bBi2S3 displays an excellent direct electrochemistry, and retains its biocatalytic activity toward the electro-reduction of hydrogen peroxide. The current response in the amperometry shows a linear response to H2O2 concentrations in the range from 0.4 to 4.8µM with high sensitivity (444µAmM(-1)) and low detection limit (0.096µM). The Michaelis-Menten constant (KM(app)) of the fabricated bioelectrode for H2O2 was determined as low as 1µM. These results demonstrate that the synthesized bBi2S3 offers a new path for the immobilization of redox-active protein and the construction of the third-generation biosensors.

  3. Long-range interactions of hydrogen atoms in excited states. II. Hyperfine-resolved (2 S -2 S ) systems

    NASA Astrophysics Data System (ADS)

    Jentschura, U. D.; Debierre, V.; Adhikari, C. M.; Matveev, A.; Kolachevsky, N.

    2017-02-01

    The interaction of two excited hydrogen atoms in metastable states constitutes a theoretically interesting problem because of the quasidegenerate 2 P1 /2 levels that are removed from the 2 S states only by the Lamb shift. The total Hamiltonian of the system is composed of the van der Waals Hamiltonian, the Lamb shift, and the hyperfine effects. The van der Waals shift becomes commensurate with the 2 S -2 P3 /2 fine-structure splitting only for close approach (R <100 a0 , where a0 is the Bohr radius) and one may thus restrict the discussion to the levels with n =2 and J =1 /2 to a good approximation. Because each S or P state splits into an F =1 triplet and an F =0 hyperfine singlet (eight states for each atom), the Hamiltonian matrix a priori is of dimension 64. A careful analysis of the symmetries of the the problem allows one to reduce the dimensionality of the most involved irreducible submatrix to 12. We determine the Hamiltonian matrices and the leading-order van der Waals shifts for states that are degenerate under the action of the unperturbed Hamiltonian (Lamb shift plus hyperfine structure). The leading first- and second-order van der Waals shifts lead to interaction energies proportional to 1 /R3 and 1 /R6 and are evaluated within the hyperfine manifolds. When both atoms are metastable 2 S states, we find an interaction energy of order Ehχ (a0/R ) 6 , where Eh and L are the Hartree and Lamb shift energies, respectively, and χ =Eh/L ≈6.22 ×106 is their ratio.

  4. Drosophila larval to pupal switch under nutrient stress requires IP3R/Ca2+ signalling in glutamatergic interneurons

    PubMed Central

    Jayakumar, Siddharth; Richhariya, Shlesha; Reddy, O Venkateswara; Texada, Michael J; Hasan, Gaiti

    2016-01-01

    Neuronal circuits are known to integrate nutritional information, but the identity of the circuit components is not completely understood. Amino acids are a class of nutrients that are vital for the growth and function of an organism. Here, we report a neuronal circuit that allows Drosophila larvae to overcome amino acid deprivation and pupariate. We find that nutrient stress is sensed by the class IV multidendritic cholinergic neurons. Through live calcium imaging experiments, we show that these cholinergic stimuli are conveyed to glutamatergic neurons in the ventral ganglion through mAChR. We further show that IP3R-dependent calcium transients in the glutamatergic neurons convey this signal to downstream medial neurosecretory cells (mNSCs). The circuit ultimately converges at the ring gland and regulates expression of ecdysteroid biosynthetic genes. Activity in this circuit is thus likely to be an adaptation that provides a layer of regulation to help surpass nutritional stress during development. DOI: http://dx.doi.org/10.7554/eLife.17495.001 PMID:27494275

  5. Interaction with specific HSP90 residues as a scoring function: validation in the D3R Grand Challenge 2015

    NASA Astrophysics Data System (ADS)

    Santos-Martins, Diogo

    2016-09-01

    Here is reported the development of a novel scoring function that performs remarkably well at identifying the native binding pose of a subset of HSP90 inhibitors containing aminopyrimidine or resorcinol based scaffolds. This scoring function is called PocketScore, and consists of the interaction energy between a ligand and three residues in the binding pocket: Asp93, Thr184 and a water molecule. We integrated PocketScore into a molecular docking workflow, and used it to participate in the Drug Design Data Resource (D3R) Grand Challenge 2015 (GC2015). PocketScore was able to rank 180 molecules of the GC2015 according to their binding affinity with satisfactory performance. These results indicate that the specific residues considered by PocketScore are determinant to properly model the interaction between HSP90 and its subset of inhibitors containing aminopyrimidine or resorcinol based scaffolds. Moreover, the development of PocketScore aimed at improving docking power while neglecting the prediction of binding affinities, suggesting that accurate identification of native binding poses is a determinant factor for the performance of virtual screens.

  6. Pressure-temperature phase diagram for orbital and spin states in RVO3(R=Y,Tb)

    NASA Astrophysics Data System (ADS)

    Bizen, Daisuke; Nakatsuka, Keisuke; Murata, Tetsuya; Nakao, Hironori; Iwasa, Kazuaki; Murakami, Youichi; Osakabe, Toyotaka; Miyasaka, Shigeki; Tokura, Yoshinori

    2008-03-01

    Perovskite-type vanadium oxides RVO3 (R=Y, La-Lu) show various physical properties coupled with the orbital and spin states. Orbitally ordered states of V 3d^2 in YVO3 have been systematically investigated by X-ray scattering technique under high-pressure and low-temperature (HP-LT). The pressure-temperature phase diagram for the orbital state was clearly determined from the crystal parameters, i.e. the lattice constants and the reflection conditions. It indicates that the C-type orbital ordering (C-OO) is stabilized as compared with the G-type orbital ordering (G-OO) by applying hydrostatic pressure. Based on the result, we succeeded in controlling the ground state of 3d-orbital in TbVO3 from G-OO to C-OO by applying pressure. The spin state coupled with the orbital was also studied by neutron scattering under HP-LT. It elucidated that the magnetic ground state changed from the C-type spin ordering to the G-type one. This result indicates the strong coupling between orbital and spin states.

  7. DockBench as docking selector tool: the lesson learned from D3R Grand Challenge 2015

    NASA Astrophysics Data System (ADS)

    Salmaso, Veronica; Sturlese, Mattia; Cuzzolin, Alberto; Moro, Stefano

    2016-09-01

    Structure-based drug design (SBDD) has matured within the last two decades as a valuable tool for the optimization of low molecular weight lead compounds to highly potent drugs. The key step in SBDD requires knowledge of the three-dimensional structure of the target-ligand complex, which is usually determined by X-ray crystallography. In the absence of structural information for the complex, SBDD relies on the generation of plausible molecular docking models. However, molecular docking protocols suffer from inaccuracies in the description of the interaction energies between the ligand and the target molecule, and often fail in the prediction of the correct binding mode. In this context, the appropriate selection of the most accurate docking protocol is absolutely relevant for the final molecular docking result, even if addressing this point is absolutely not a trivial task. D3R Grand Challenge 2015 has represented a precious opportunity to test the performance of DockBench, an integrate informatics platform to automatically compare RMDS-based molecular docking performances of different docking/scoring methods. The overall performance resulted in the blind prediction are encouraging in particular for the pose prediction task, in which several complex were predicted with a sufficient accuracy for medicinal chemistry purposes.

  8. DockBench as docking selector tool: the lesson learned from D3R Grand Challenge 2015.

    PubMed

    Salmaso, Veronica; Sturlese, Mattia; Cuzzolin, Alberto; Moro, Stefano

    2016-09-01

    Structure-based drug design (SBDD) has matured within the last two decades as a valuable tool for the optimization of low molecular weight lead compounds to highly potent drugs. The key step in SBDD requires knowledge of the three-dimensional structure of the target-ligand complex, which is usually determined by X-ray crystallography. In the absence of structural information for the complex, SBDD relies on the generation of plausible molecular docking models. However, molecular docking protocols suffer from inaccuracies in the description of the interaction energies between the ligand and the target molecule, and often fail in the prediction of the correct binding mode. In this context, the appropriate selection of the most accurate docking protocol is absolutely relevant for the final molecular docking result, even if addressing this point is absolutely not a trivial task. D3R Grand Challenge 2015 has represented a precious opportunity to test the performance of DockBench, an integrate informatics platform to automatically compare RMDS-based molecular docking performances of different docking/scoring methods. The overall performance resulted in the blind prediction are encouraging in particular for the pose prediction task, in which several complex were predicted with a sufficient accuracy for medicinal chemistry purposes.

  9. Modulation of Elementary Calcium Release Mediates a Transition from Puffs to Waves in an IP3R Cluster Model

    PubMed Central

    Rückl, Martin; Parker, Ian; Marchant, Jonathan S.; Nagaiah, Chamakuri; Johenning, Friedrich W.; Rüdiger, Sten

    2015-01-01

    The oscillating concentration of intracellular calcium is one of the most important examples for collective dynamics in cell biology. Localized releases of calcium through clusters of inositol 1,4,5-trisphosphate receptor channels constitute elementary signals called calcium puffs. Coupling by diffusing calcium leads to global releases and waves, but the exact mechanism of inter-cluster coupling and triggering of waves is unknown. To elucidate the relation of puffs and waves, we here model a cluster of IP3R channels using a gating scheme with variable non-equilibrium IP3 binding. Hybrid stochastic and deterministic simulations show that puffs are not stereotyped events of constant duration but are sensitive to stimulation strength and residual calcium. For increasing IP3 concentration, the release events become modulated at a timescale of minutes, with repetitive wave-like releases interspersed with several puffs. This modulation is consistent with experimental observations we present, including refractoriness and increase of puff frequency during the inter-wave interval. Our results suggest that waves are established by a random but time-modulated appearance of sustained release events, which have a high potential to trigger and synchronize activity throughout the cell. PMID:25569772

  10. Novel Functional Role of NK3R Expression in the Potentiating Effects on Somatolactin α Autoregulation in grass carp pituitary cells

    PubMed Central

    Hu, Guangfu; He, Mulan; Wong, Anderson On Lam

    2016-01-01

    In our previous study, NKB/NK3R system has been shown to act at the pituitary level to up-regulate SLα synthesis and secretion in grass carp. However, whether NK3R expression can serve as a regulatory target at the pituitary level and contribute to NKB interactions with other SLα regulators is still unclear. In current study, using grass carp pituitary cells as a model, we have a novel finding that co-treatment of SLα/SLβ with carp TAC3 gene products, could induce a noticeable enhancement in SLα mRNA expression and these potentiating effects occurred with a parallel rise in NK3R transcript level after SLα/SLβ treatment. Interestingly, the stimulatory effects of SLα/SLβ on NK3R gene expression could be further potentiated by co-treatment with IGF-I/-II and simultaneous exposure of carp pituitary cells to SLα/SLβ and IGF-I/-II in the presence of TAC3 gene products was found to markedly elevated SLα mRNA expression (20 fold increase) and this synergistic stimulation was mediated by cAMP/PKA-, PLC/PKC- and Ca2+ -dependent cascades functionally coupled with NK3R activation. These findings suggest that local release of SLα via functional interactions with IGF-I/-II and TAC3/NK3R system may constitute a potent stimulatory signal for SLα gene expression in the carp pituitary via up-regulation of NK3R expression. PMID:27786296

  11. Asymmetry in the triplet 3p-4s Mg lines in cool DZ white dwarfs

    NASA Astrophysics Data System (ADS)

    Allard, N. F.; Leininger, T.; Gadéa, F. X.; Brousseau-Couture, V.; Dufour, P.

    2016-04-01

    The purpose of the present work is to make an exhaustive study of the line shape of the triplet 3p-4s Mg line (Mgb triplet), which is perturbed by He in the extreme physical conditions found in the cool atmosphere of DZ white dwarfs. This study is undertaken by inferring both a unified theory of spectral line broadening and ab initio potential energies. Cool white dwarfs require a specific treatment for line broadening owing to the high helium densities that are involved. Beyond the conventional symmetrical Lorentzian core at low density, we show that the line profiles are asymmetrical and have significant additional contributions on the short wavelength side. This blue asymmetry is a consequence of low maxima in the corresponding Mg-He potential energy difference curves at short and intermediate internuclear distances. The new profiles are shown to provide a good fit to an SDSS (Sloan Digital Sky Survey) observation.

  12. Superconducting properties of Rh9In4S4 single crystals

    DOE PAGES

    Kaluarachchi, Udhara S.; Lin, Qisheng; Xie, Weiwei; ...

    2016-03-28

    The synthesis and crystallographic, thermodynamic, and transport properties of single crystalline Rh9In4S4 were studied. The resistivity, magnetization, and specific heat measurements all clearly indicate bulk superconductivity with a critical temperature, Tc~2.25 K. The Sommerfeld coefficient γ and the Debye temperature (ΘD) were found to be 34 mJ mol–1 K–2 and 217 K, respectively. The observed specific heat jump, ΔC/γTc=1.66, is larger than the expected BCS weak coupling value of 1.43. Ginzburg-Landau (GL) ratio of the low-temperature GL-penetration depth, λGL≈5750 Å, to the GL-coherence length, ξGL≈94 Å, is large: κ ~60. However, we observed a peak effect in the resistivity measurementmore » as a function of both temperature and magnetic field.« less

  13. Exchange anisotropy in the skyrmion host GaV4S8.

    PubMed

    Ehlers, D; Stasinopoulos, I; Kézsmárki, I; Fehér, T; Tsurkan, V; von Nidda, H-A Krug; Grundler, D; Loidl, A

    2017-02-15

    Using ferromagnetic resonance spectroscopy at 34 GHz we explored the magnetic anisotropy of single-crystalline GaV4S8 in the field-polarized magnetic state. We describe the data in terms of an easy-axis type uniaxial anisotropy with an anisotropy constant [Formula: see text] erg cm(-3) at 2 K, corresponding to a relative exchange anisotropy [Formula: see text]%, and about [Formula: see text]erg cm(-3) near 11 K, i.e. at temperatures where the skyrmion-lattice phase was recently discovered. The relatively large value of K 1 explains the confinement of the skyrmion tubes to the [Formula: see text] easy axes. A distinct set of resonances in the spectra is attributed to the co-existence of different rhombohedral domains. Complementary broadband spectroscopy demonstrates that non-collinear spin states may sensitively be detected by electron spin resonance techniques.

  14. De novo design of an artificial bis[4Fe-4S] binding protein.

    PubMed

    Roy, Anindya; Sarrou, Iosifina; Vaughn, Michael D; Astashkin, Andrei V; Ghirlanda, Giovanna

    2013-10-29

    In nature, protein subunits containing multiple iron-sulfur clusters often mediate the delivery of reducing equivalents from metabolic pathways to the active site of redox proteins. The de novo design of redox active proteins should include the engineering of a conduit for the delivery of electrons to and from the active site, in which multiple redox active centers are arranged in a controlled manner. Here, we describe a designed three-helix protein, DSD-bis[4Fe-4S], that coordinates two iron-sulfur clusters within its hydrophobic core. The design exploits the pseudo two-fold symmetry of the protein scaffold, DSD, which is a homodimeric three-helix bundle. Starting from the sequence of the parent peptide, we mutated eight leucine residues per dimer in the hydrophobic core to cysteine to provide the first coordination sphere for cubane-type iron-sulfur clusters. Incorporation of two clusters per dimer is readily achieved by in situ reconstitution and imparts increased stability to thermal denaturation compared to that of the apo form of the peptide as assessed by circular dichroism-monitored thermal denaturation. The presence of [4Fe-4S] clusters in intact proteins is confirmed by UV-vis spectroscopy, gel filtration, analytical ultracentrifugation, and electron paramagnetic resonance spectroscopy. Pulsed electron-electron double-resonance experiments have detected a magnetic dipole interaction between the two clusters ~0.7 MHz, which is consistent with the expected intercluster distance of 29-34 Å. Taken together, our data demonstrate the successful design of an artificial multi-iron-sulfur cluster protein with evidence of cluster-cluster interaction. The design principles implemented here can be extended to the design of multicluster molecular wires.

  15. Sulfur K-Edge XAS and DFT Calculations on [Fe4S4]2+Clusters: Effects of H-bonding and Structural Distortion on Covalency and SpinTopology

    SciTech Connect

    Dey, A.; Roche, C.L.; Walters, M.A.; Hodgson, K.O.; B., Hedman; Solomon, E.I.; /Stanford U., Chem. Dept. /SLAC, SSRL

    2006-09-28

    Sulfur K-edge X-ray absorption spectroscopy of a hydrogen-bonded elongated [Fe{sub 4}S{sub 4}]{sup 2+} cube is reported. The data show that this synthetic cube is less covalent than a normal compressed cube with no hydrogen bonding. DFT calculations reveal that the observed difference in electronic structure has significant contributions from both the cluster distortion and from hydrogen bonding. The elongated and compressed Fe{sub 4}S{sub 4} structures are found to have different spin topologies (i.e., orientation of the delocalized Fe{sub 2}S{sub 2} subclusters which are antiferromagnetically coupled to each other). It is suggested that the H-bonding interaction with the counterion does not contribute to the cluster elongation. A magneto-structural correlation is developed for the Fe{sub 4}S{sub 4} cube that is used to identify the redoxactive Fe{sub 2}S{sub 2} subclusters in active sites of HiPIP and ferredoxin proteins involving these clusters.

  16. Single step transformation of sulphur to Li2S2/Li2S in Li-S batteries

    PubMed Central

    Helen, M.; Reddy, M. Anji; Diemant, Thomas; Golla-Schindler, Ute; Behm, R. Jürgen; Kaiser, Ute; Fichtner, Maximilian

    2015-01-01

    Lithium-sulphur batteries have generated tremendous research interest due to their high theoretical energy density and potential cost-effectiveness. The commercial realization of Li-S batteries is still hampered by reduced cycle life associated with the formation of electrolyte soluble higher-order polysulphide (Li2Sx, x = 4–8) intermediates, leading to capacity fading, self-discharge, and a multistep voltage profile. Herein, we have realized a practical approach towards a direct transformation of sulphur to Li2S2/Li2S in lithium-sulphur batteries by alteration of the reaction pathway. A coconut shell derived ultramicroporous carbon-sulphur composite cathode has been used as reaction directing template for the sulphur. The lithiation/delithiation and capacity fading mechanism of microporous carbon confined sulphur composite was revealed by analyzing the subsurface using X-ray photoelectron spectroscopy. No higher-order polysulphides were detected in the electrolyte, on the surface, and in the subsurface of the cathode composite. The altered reaction pathway is reflected by a single-step profile in the discharge/charge of a lithium-sulphur cell. PMID:26173723

  17. Phonon dispersion relations of Sb2S3 and Bi2S3 using the supercell force-constant method

    NASA Astrophysics Data System (ADS)

    Gan, Chee Kwan; Chua, Kun Ting Eddie; Liu, Yun

    2015-03-01

    We present a lattice dynamical study on the orthorhombic antimony sulphide (Sb2S3) and bismuth sulphide (Bi2S3) using the supercell force-constant method. We find that the slow decay of the interatomic force constants for these compounds in the Pnma setting critically demand the use of a large supercell of 2 × 4 × 2 that consists of 320 atoms. To enable a practical calculation the space group information is fully utilized where only inequivalent atoms within the primitive cell are displaced for the force calculations. The effect of Born effective charges is incorporated into the method. We compare our results with that obtained from the density-functional perturbation theory. We found that smaller supercells could lead to unphysical acoustic phonon softening and lifting of the degeneracies along high symmetry directions. Our results provide a proper guideline for the use of the supercell force-constant method: the supercell size must be carefully be tested along with other parameters such as the kinetic energy cutoff, the Brillouin zone sampling or the self-consistent convergence criteria.

  18. Single step transformation of sulphur to Li2S2/Li2S in Li-S batteries

    NASA Astrophysics Data System (ADS)

    Helen, M.; Reddy, M. Anji; Diemant, Thomas; Golla-Schindler, Ute; Behm, R. Jürgen; Kaiser, Ute; Fichtner, Maximilian

    2015-07-01

    Lithium-sulphur batteries have generated tremendous research interest due to their high theoretical energy density and potential cost-effectiveness. The commercial realization of Li-S batteries is still hampered by reduced cycle life associated with the formation of electrolyte soluble higher-order polysulphide (Li2Sx, x = 4-8) intermediates, leading to capacity fading, self-discharge, and a multistep voltage profile. Herein, we have realized a practical approach towards a direct transformation of sulphur to Li2S2/Li2S in lithium-sulphur batteries by alteration of the reaction pathway. A coconut shell derived ultramicroporous carbon-sulphur composite cathode has been used as reaction directing template for the sulphur. The lithiation/delithiation and capacity fading mechanism of microporous carbon confined sulphur composite was revealed by analyzing the subsurface using X-ray photoelectron spectroscopy. No higher-order polysulphides were detected in the electrolyte, on the surface, and in the subsurface of the cathode composite. The altered reaction pathway is reflected by a single-step profile in the discharge/charge of a lithium-sulphur cell.

  19. Lowest ^{2}S Electronic Excitations of the Boron Atom.

    PubMed

    Bubin, Sergiy; Adamowicz, Ludwik

    2017-01-27

    A theoretical ab initio approach for calculating bound states of small atoms is developed and implemented. The approach is based on finite-nuclear-mass [non-Born-Oppenheimer (non-BO)] nonrelativistic variational calculations performed with all-particle explicitly correlated Gaussian functions and includes the leading relativistic and quantum electrodynamics energy corrections determined using the non-BO wave functions. The approach is applied to determine the total and transition energies for the lowest four ^{2}S electronic excitations of the boron atom. The transition energies agree with the available experimental values within 0.2-0.3  cm^{-1}. Previously, such accuracy was achieved for three- and four-electron systems.

  20. Scada system oversees Canadian H sub 2 S field, pipelines

    SciTech Connect

    Greenslade, J.G. ); Wichert, E. )

    1992-05-25

    Important new safety and operational features and some industry firsts are employed in a PC-based supervisory control and data acquisition (scada) system at Phillips Petroleum Resources Ltd.'s Ghost River sour-gas field and pipeline in a populated area near Calgary. This paper reports on the scada system monitors and controls wells, line-heaters, pumps, and alarm and shutdown systems. facilities are operated on a partially attended basis. Operators carry cellular telephones and laptop computers equipped with internal modems to enable them to receive alarms and take appropriate action promptly. Several safety features are incorporated into the alarm and shutdown system. All aboveground facilities are equipped with atmospheric monitors for H{sub 2}S. Leak detection is inferred from continuous material-balance computation. Should a sour-gas leak be suspected, an automated resident-notification system provides early notice by telephone to potentially affected residents.

  1. Lowest 2S Electronic Excitations of the Boron Atom

    NASA Astrophysics Data System (ADS)

    Bubin, Sergiy; Adamowicz, Ludwik

    2017-01-01

    A theoretical ab initio approach for calculating bound states of small atoms is developed and implemented. The approach is based on finite-nuclear-mass [non-Born-Oppenheimer (non-BO)] nonrelativistic variational calculations performed with all-particle explicitly correlated Gaussian functions and includes the leading relativistic and quantum electrodynamics energy corrections determined using the non-BO wave functions. The approach is applied to determine the total and transition energies for the lowest four 2S electronic excitations of the boron atom. The transition energies agree with the available experimental values within 0.2 - 0.3 cm-1 . Previously, such accuracy was achieved for three- and four-electron systems.

  2. User's Manual for TMY2s - Typical Meteorological Years

    SciTech Connect

    1995-06-01

    This user's manual describes typical meteorological year (TMY) data sets derived from the 1961-1990 National Solar Radiation Data Base (NSRDB). Because they are based on more recent and accurate data and will make possible more accurate performance and economic analyses of energy systems, these data sets are ecommended for use in place of earlier TMY data sets derived from the 1952-1975 SOLMET/ERSATZ data base. To distinguish between the old and new TMY data sets, the new TMY data sets are referred to as TMY2s. TMY and TMY2 data sets cannot be used interchangeably because of differences in time (solar versus local), formats, elements, and units. Unless they are revised, computer programs designed for TMY data will not work with TMY2 data.

  3. Phase equilibria in the quasiternary system Ag2S-Ga2S3-In2S3 and optical properties of (Ga55In45)2S300, (Ga54.59In44.66Er0.75)2S300 single crystals

    NASA Astrophysics Data System (ADS)

    Ivashchenko, I. A.; Danyliuk, I. V.; Olekseyuk, I. D.; Pankevych, V. Z.; Halyan, V. V.

    2015-07-01

    The quasiternary system Ag2S-Ga2S3-In2S3 was investigated by differential thermal, X-ray diffraction analyses. The phase diagram of the Ga2S3-In2S3 system and nine polythermal sections, isothermal section at 820 K and the liquidus surface projection were constructed. The existence of the large solid solutions ranges of binary and ternary compounds was established. The range of the existence of the quaternary phase AgGaxIn5-xS8 (2.25≤x≤2.85) at 820 K was determined. The single crystals (Ga55In45)2S300 and (Ga54.59In44.66Er0.75)2S300 were grown by a directional crystallization method from solution-melt. Optical absorption spectra in the 500-1600 nm range were recorded. The luminescence of the (Ga54.59In44.66Er0.75)2S300 single crystal shows a maximum at 1530 nm for the excitation wavelengths of 532 and 980 nm at 80 and 300 K.

  4. A Large-scale Relativistic Configuration-interaction Approach: Application to the 4s2 - 4s4p Transition Energies and E1 Rates for Zn-like Ions

    SciTech Connect

    Chen, M H; Cheng, K T

    2009-08-28

    Relativistic configuration-interaction calculations of the 4s4p excitation energies and 4s{sup 2} - 4s4p E1 transitions for Zn-like ions from Z = 30 to 92 are shown. B-spline basis functions are used for these large-scale calculations. QED corrections to the excitation energies are also calculated. Results are in good agreement with other theories and with experiment, and demonstrate the utility of this method for high-precision atomic structure calculations not just for few-electron systems but also for large atomic systems such as Zn-like ions along the entire isoelectronic sequence.

  5. MicroRNA-126 affects rheumatoid arthritis synovial fibroblast proliferation and apoptosis by targeting PIK3R2 and regulating PI3K-AKT signal pathway

    PubMed Central

    Deng, Jia-Xin; Zhang, Yu-Ping; Liang, Wan-Yi; Jiang, Zhen-Lan; Yu, Qing-Hong; Li, Juan

    2016-01-01

    Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes inflammation and destruction of the joints as well as an increased risk of cardiovascular disease. RA synovial fibroblasts (RASFs) are involved in the progression of RA and release pro-inflammatory cytokines. On the other hand, microRNAs (miRs) may help control the inflammatory response of immune and non-immune cells. Therefore, our study used lentiviral expression vectors to test the effects of miR-126 overexpression on RASF proliferation and apoptosis. Luciferase experiments verified the targeting relationship between miR-126 and PIK3R2 gene. The co-transfection of anti-miR-126 and PIK3R2 siRNA to RASFs were used to identify whether PIK3R2 was directly involved in proliferation and apoptosis of miR-126-induced RASFs. Real-time polymerase chain reaction (PCR) was used to detect miR-126 and PIK3R2 expressions. MTT assay was used to detect cell proliferation. Flow cytometry was used to detect cell apoptosis and cell cycle. Western blotting was used to detect PIK3R2, PI3K, AKT and p-AKT proteins. After Lv-miR-126 infected RASFs, the relative expression of miR-126 was significantly enhanced. MiR-126 promoted RASF proliferation and inhibited apoptosis. Levels of PIK3R2 decreased while total PI3K and p-AKT levels increased in RASFs overexpressing miR-126. Co-transfection of anti-miR-126 and PIK3R2 siRNA also increased PI3K and p-AKT levels as well as RASF proliferation and reduced apoptosis, as compared to anti-miR-126 treatment alone. Finally, luciferase reporter assays showed that miR-126 targeted PIK3R2. Our data indicate that miR-126 overexpression in RASFs inhibits PIK3R2 expression and promotes proliferation while inhibiting apoptosis. This suggests inhibiting miR-126 may yield therapeutic benefits in the treatment of RA. PMID:27729613

  6. Automatic sorting of toxicological information into the IUCLID (International Uniform Chemical Information Database) endpoint-categories making use of the semantic search engine Go3R.

    PubMed

    Sauer, Ursula G; Wächter, Thomas; Hareng, Lars; Wareing, Britta; Langsch, Angelika; Zschunke, Matthias; Alvers, Michael R; Landsiedel, Robert

    2014-06-01

    The knowledge-based search engine Go3R, www.Go3R.org, has been developed to assist scientists from industry and regulatory authorities in collecting comprehensive toxicological information with a special focus on identifying available alternatives to animal testing. The semantic search paradigm of Go3R makes use of expert knowledge on 3Rs methods and regulatory toxicology, laid down in the ontology, a network of concepts, terms, and synonyms, to recognize the contents of documents. Search results are automatically sorted into a dynamic table of contents presented alongside the list of documents retrieved. This table of contents allows the user to quickly filter the set of documents by topics of interest. Documents containing hazard information are automatically assigned to a user interface following the endpoint-specific IUCLID5 categorization scheme required, e.g. for REACH registration dossiers. For this purpose, complex endpoint-specific search queries were compiled and integrated into the search engine (based upon a gold standard of 310 references that had been assigned manually to the different endpoint categories). Go3R sorts 87% of the references concordantly into the respective IUCLID5 categories. Currently, Go3R searches in the 22 million documents available in the PubMed and TOXNET databases. However, it can be customized to search in other databases including in-house databanks.

  7. Dyrk1A overexpression leads to increase of 3R-tau expression and cognitive deficits in Ts65Dn Down syndrome mice.

    PubMed

    Yin, Xiaomin; Jin, Nana; Shi, Jianhua; Zhang, Yanchong; Wu, Yue; Gong, Cheng-Xin; Iqbal, Khalid; Liu, Fei

    2017-04-04

    Alternative splicing of tau exon 10 generates tau isoforms with three or four microtubule-binding repeats, 3R-tau and 4R-tau, which is equally expressed in adult human brain. Imbalanced expression in 3R-tau and 4R-tau has been found in several sporadic and inherited tauopathies, suggesting that dysregulation of tau exon 10 is sufficient to cause neurodegenerative diseases. We previously reported that Dyrk1A, which is overexpressed in Down syndrome brains, regulates alternative splicing of exogenous tau exon 10. In the present study, we investigated the regulation of endogenous tau exon 10 splicing by Dyrk1A. We found that inhibition of Dyrk1A enhanced tau exon 10 inclusion, leading to an increase in 4R-tau/3R-tau ratio in differentiated-human neuronal progenitors and in the neonatal rat brains. Accompanied with overexpression of Dyrk1A, 3R-tau was increased and 4R-tau was decreased in the neonatal brains of Ts65Dn mice, a model of Down syndrome. Treatment with Dyrk1A inhibitor, green tea flavonol epigallocatechin-gallate (EGCG), from gestation to adulthood suppressed 3R-tau expression and rescued anxiety and memory deficits in Ts65Dn mouse brains. Thus, Dyrk1A might be an ideal therapeutic target for Alzheimer's disease, especially for Down syndrome and EGCG which inhibits Dyrk1A may have potential effect on the treatment or prevention of this disease.

  8. Obstacle course: users' maneuverability and movement efficiency when using Otto Bock C-Leg, Otto Bock 3R60, and CaTech SNS prosthetic knee joints.

    PubMed

    Meier, Margrit R; Hansen, Andrew H; Gard, Steven A; McFadyen, Angus K

    2012-01-01

    The performance and movement efficiency of prosthesis users while traversing a multisectional obstacle course (OC) were evaluated using a crossover design with random allocation of three prosthetic knee joints: the SNS (CaTech; Dayton, Ohio) the C-Leg (Otto Bock; Duderstadt, Germany), and the 3R60 (Otto Bock). Twelve users completed the OC twice with each joint, once without and once with a mental loading task (MLT). The performance was objectively assessed using time measurement from digital video recordings, and the Total Heart Beat Index was used to estimate movement efficiency. A 1 mo familiarization period was provided for each knee joint before data collection. It took longer to complete the OC with the 3R60 compared with either the SNS or the C-Leg. No significant time differences were found between the C-Leg and the SNS, but differences between the 3R60 and the SNS (slalom and rock sections) and between the 3R60 and the C-Leg (rock section) were observed. Within the simulated sand section, two participants fell with the C-Leg, one with the 3R60, and none with the SNS. Movement efficiency without MLT was similar between all joints, but with an MLT a significant decrease in movement efficiency was observed with the C-Leg. Previous experience using an SNS had no influence on the results.

  9. The H2S Donor NaHS Changes the Expression Pattern of H2S-Producing Enzymes after Myocardial Infarction.

    PubMed

    Li, Na; Wang, Ming-Jie; Jin, Sheng; Bai, Ya-Dan; Hou, Cui-Lan; Ma, Fen-Fen; Li, Xing-Hui; Zhu, Yi-Chun

    2016-01-01

    Aims. To examine the expression patterns of hydrogen sulphide- (H2S-) producing enzymes in ischaemic heart tissue and plasma levels of H2S after 2 weeks of NaHS treatment after myocardial infarction (MI) and to clarify the role of endogenous H2S in the MI process. Results. After MI surgery, 2 weeks of treatment with the H2S donor NaHS alleviated ischaemic injury. Meanwhile, in ischemia myocardium, three H2S-producing enzymes, cystathionine γ-lyase (CSE), cystathionine-β-synthase (CBS), and 3-mercaptopyruvate sulfurtransferase (3-MST) significantly increased. Plasma H2S levels were also elevated. In vitro, NaHS treatment protected cardiomyocytes from hypoxic injury and raised CBS levels in a concentration-dependent manner. Different from in vivo results, however, CSE or 3-MST expression did not change. NaHS treatment increased the activity of CSE/CBS but not of 3-MST. When CSE was either knocked down (in vitro) or knocked out (in vivo), H2S levels significantly decreased, which subsequently exacerbated the ischaemic injury. Meanwhile, the expressions of CBS and 3-MST increased due to compensation. Conclusions. Exogenous H2S treatment changed the expressions of three H2S-producing enzymes and H2S levels after MI, suggesting a new and indirect regulatory mechanism for H2S production and its contribution to cardiac protection. Endogenous H2S plays an important role in protecting ischaemic tissue after MI.

  10. Apamin Boosting of Synaptic Potentials in CaV2.3 R-Type Ca2+ Channel Null Mice.

    PubMed

    Wang, Kang; Kelley, Melissa H; Wu, Wendy W; Adelman, John P; Maylie, James

    2015-01-01

    SK2- and KV4.2-containing K+ channels modulate evoked synaptic potentials in CA1 pyramidal neurons. Each is coupled to a distinct Ca2+ source that provides Ca2+-dependent feedback regulation to limit AMPA receptor (AMPAR)- and NMDA receptor (NMDAR)-mediated postsynaptic depolarization. SK2-containing channels are activated by Ca2+ entry through NMDARs, whereas KV4.2-containing channel availability is increased by Ca2+ entry through SNX-482 (SNX) sensitive CaV2.3 R-type Ca2+ channels. Recent studies have challenged the functional coupling between NMDARs and SK2-containing channels, suggesting that synaptic SK2-containing channels are instead activated by Ca2+ entry through R-type Ca2+ channels. Furthermore, SNX has been implicated to have off target affects, which would challenge the proposed coupling between R-type Ca2+ channels and KV4.2-containing K+ channels. To reconcile these conflicting results, we evaluated the effect of SK channel blocker apamin and R-type Ca2+ channel blocker SNX on evoked excitatory postsynaptic potentials (EPSPs) in CA1 pyramidal neurons from CaV2.3 null mice. The results show that in the absence of CaV2.3 channels, apamin application still boosted EPSPs. The boosting effect of CaV2.3 channel blockers on EPSPs observed in neurons from wild type mice was not observed in neurons from CaV2.3 null mice. These data are consistent with a model in which SK2-containing channels are functionally coupled to NMDARs and KV4.2-containing channels to CaV2.3 channels to provide negative feedback regulation of EPSPs in the spines of CA1 pyramidal neurons.

  11. Optimal strategies for virtual screening of induced-fit and flexible target in the 2015 D3R Grand Challenge

    NASA Astrophysics Data System (ADS)

    Ye, Zhaofeng; Baumgartner, Matthew P.; Wingert, Bentley M.; Camacho, Carlos J.

    2016-09-01

    Induced fit or protein flexibility can make a given structure less useful for docking and/or scoring. The 2015 Drug Design Data Resource (D3R) Grand Challenge provided a unique opportunity to prospectively test optimal strategies for virtual screening in these type of targets: heat shock protein 90 (HSP90), a protein with multiple ligand-induced binding modes; and mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4), a kinase with a large flexible pocket. Using previously known co-crystal structures, we tested predictions from methods that keep the receptor structure fixed and used (a) multiple receptor/ligand co-crystals as binding templates for minimization or docking ("close"), (b) methods that align or dock to a single receptor ("cross"), and (c) a hybrid approach that chose from multiple bound ligands as initial templates for minimization to a single receptor ("min-cross"). Pose prediction using our "close" models resulted in average ligand RMSDs of 0.32 and 1.6 Å for HSP90 and MAP4K4, respectively, the most accurate models of the community-wide challenge. On the other hand, affinity ranking using our "cross" methods performed well overall despite the fact that a fixed receptor cannot model ligand-induced structural changes,. In addition, "close" methods that leverage the co-crystals of the different binding modes of HSP90 also predicted the best affinity ranking. Our studies suggest that analysis of changes on the receptor structure upon ligand binding can help select an optimal virtual screening strategy.

  12. Optimal strategies for virtual screening of induced-fit and flexible target in the 2015 D3R Grand Challenge.

    PubMed

    Ye, Zhaofeng; Baumgartner, Matthew P; Wingert, Bentley M; Camacho, Carlos J

    2016-09-01

    Induced fit or protein flexibility can make a given structure less useful for docking and/or scoring. The 2015 Drug Design Data Resource (D3R) Grand Challenge provided a unique opportunity to prospectively test optimal strategies for virtual screening in these type of targets: heat shock protein 90 (HSP90), a protein with multiple ligand-induced binding modes; and mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4), a kinase with a large flexible pocket. Using previously known co-crystal structures, we tested predictions from methods that keep the receptor structure fixed and used (a) multiple receptor/ligand co-crystals as binding templates for minimization or docking ("close"), (b) methods that align or dock to a single receptor ("cross"), and (c) a hybrid approach that chose from multiple bound ligands as initial templates for minimization to a single receptor ("min-cross"). Pose prediction using our "close" models resulted in average ligand RMSDs of 0.32 and 1.6 Å for HSP90 and MAP4K4, respectively, the most accurate models of the community-wide challenge. On the other hand, affinity ranking using our "cross" methods performed well overall despite the fact that a fixed receptor cannot model ligand-induced structural changes,. In addition, "close" methods that leverage the co-crystals of the different binding modes of HSP90 also predicted the best affinity ranking. Our studies suggest that analysis of changes on the receptor structure upon ligand binding can help select an optimal virtual screening strategy.

  13. A Nitrogen-Fixing Subunit Essential for Accumulating 4Fe-4S-Containing Photosystem I Core Proteins1[OPEN

    PubMed Central

    Nath, Krishna; Wessendorf, Ryan L.

    2016-01-01

    Nitrogen-fixation-subunit-U (NFU)-type proteins have been shown to be involved in the biogenesis of iron-sulfur clusters. We investigated the molecular function of a chloroplastic NFU-type iron-sulfur scaffold protein, NFU3, in Arabidopsis (Arabidopsis thaliana) using genetics approaches. Loss-of-function mutations in the NFU3 gene caused yellow pigmentation in leaves, reductions in plant size, leaf size, and growth rate, delay in flowering and seeding, and decreases in seed production. Biochemical and physiological analyses indicated that these defects are due to the substantial reductions in the abundances of 4Fe-4S-containing photosystem I (PSI) core subunits PsaA (where Psa stands for PSI), PsaB, and PsaC and a nearly complete loss of PSI activity. In addition to the substantial decreases in the amounts of PSI core proteins, the content of 3Fe-4S-containing ferredoxin-dependent glutamine oxoglutarate aminotransferases declined significantly in the nfu3 mutants. Furthermore, the absorption spectrum of the recombinant NFU3 protein showed features characteristic of 4Fe-4S and 3Fe-4S clusters, and the in vitro reconstitution experiment indicated an iron-sulfur scaffold function of NFU3. These data demonstrate that NFU3 is involved in the assembly and transfer of 4Fe-4S and 3Fe-4S clusters and that NFU3 is required for the accumulation of 4Fe-4S- and 3Fe-4S-containing proteins, especially 4Fe-4S-containing PSI core subunits, in the Arabidopsis chloroplast. PMID:27784767

  14. Glass structure and electrical conductivity in (As2S3 1-x (Ag2S)x

    NASA Astrophysics Data System (ADS)

    Holbrook, C.; Chen, P.; Novita, D.; Boolchand, P.

    2006-03-01

    We have synthesized titled glasses in the 0 < x < 0.16 range, and have examined them in modulated DSC experiments. The starting materials, As2S3 and Ag2S lumps, were reacted in evacuated fused quartz tubings, and glasses synthesized by water-quench of homogenized melts. Thermal measurements used a TA instruments model 2920 operated at 3 C/min scan rate and 1 C/100s modulation rate. Preliminary results reveal a single glass transition in the 0 < x < 0.05 range, which steadily decrease from a value of 210 C at x = 0 to 182 C near x = 0.05. In contrast, bimodal glass transitions are observed at x > 0.09, with one Tg(1) near 167 C and the second, Tg(2) near 186 C, and with the endotherm associated with Tg(1) steadily increasing with x. Non-reversing enthalpies associated with Tgs are found to steadily decrease in the 0 < x < 0.09 range, to nearly vanish in the 0.10 < x < 0.12 range and to increase thereafter ( x > 0.12).These findings suggest that glasses at low x ( < 0.09) are Stressed- rigid, those at x > 0.12 Floppy while those in between in the Intermediate phase^1. The present results correlate well with earlier^2 electrical conductivity results in suggesting the possibility of an elastic origin to the conductivity thresholds in solid electrolyte glasses. 1. P. Boolchand, D.Georgiev and B. Goodman, J.Opto & Adm. Mater. 3, 703 (2001). 2. E.A. Kazakova and Z.U.Borisova, Fiz. Khim.Stekla 6, 424(1980).

  15. Transmission electron microscopy study of the MgS–Tm{sub 2}S{sub 3} system

    SciTech Connect

    Varadé-López, R.; Ávila-Brande, D.; Urones-Garrote, E.; Otero-Díaz, L.C.

    2015-09-15

    This work presents the structural–microstructural characterization of the NaCl-derivative MgS–Tm{sub 2}S{sub 3} system, which can be formulated by the expression Mg{sub (1−x)}Tm{sub (2/3)x}□{sub (1/3)x}S (□→cation vacancy). Transmission electron microscopy observations show the transition between NaCl-type and spinel-type structures when 0 ≤x≤ 0.75. The increase of Tm content in the solid solution provokes the increase of the spinel-type phase proportion, which intergrows with the NaCl-type crystals. When x≥0.75, some phases derived from NaCl-type structure through the chemical twinning at the unit cell level crystallographic operation are observed, such as CT-MgTm{sub 2}S{sub 4} and CT-MgTm{sub 4}S{sub 7}. The existence and nature of the extended defects observed along the c direction of these structures are characterized by means of Scanning-Transmission electron microscopy high-angle dark field imaging, which allows observing the presence of quasi ordered crystals with new possible complex stoichiometries at atomic resolution. - Graphical abstract: HAADF-STEM image of a disordered CT-MgYb{sub 2}S{sub 4} crystal. The disordered twin-slab sequences are marked by arrows. - Highlights: • Structural evolution of the Mg{sub (1−x)}Tm{sub (2/3)x}□{sub (1/3)x}S system was characterized by means of TEM. • The increase in Tm content provokes the transition from NaCl to spinel-type structure up to x=0.75. • Chemical twinned phases CT-MgTm{sub 2}S{sub 4} and CT-MgTm{sub 4}S{sub 7} are observed at high Tm contents. • Extended defects in CT-crystals are characterized with atomic resolution STEM-HAADF images.

  16. Assessing Interactions Between Ghsr and Mc3r Reveals a Role for AgRP in the Expression of Food Anticipatory Activity in Male Mice

    PubMed Central

    Girardet, Clemence; Mavrikaki, Maria; Southern, Mark R.; Smith, Roy G.

    2014-01-01

    The stomach hormone ghrelin and hypothalamic melanocortin neurons belong to a gut-brain circuit controlling appetite and metabolic homeostasis. Mice lacking melanocortin-3 receptor (Mc3rKO) or growth hormone secretagogue receptor (GhsrKO) genes exhibit attenuated food anticipatory activity (FAA), a rise in locomotor activity anticipating mealtime, suggesting common circuitry regulating anticipatory responses to nutrient loading. To investigate the interaction between Ghsrs and Mc3rs, we compared food anticipatory responses in GhsrKO, Mc3rKO, and double Ghsr;Mc3r knockout (DKO) mice subjected to a hypocaloric restricted feeding (RF) protocol in constant dark or 12-hour light, 12-hour dark settings. DKO are viable, exhibiting no overt behavioral or metabolic phenotypes in ad libitum or fasting conditions. FAA was initially attenuated in all mutant strains in constant darkness. However, GhsrKO eventually exhibited a robust food anticipatory response, suggesting compensation. Mc3rKO and DKO did not compensate, indicating a continued requirement for Mc3rs in maintaining the expression of FAA in situations of RF. Abnormal regulation of hypothalamic agouti-related peptide/neuropeptide Y (AgRP/Npy) neurons previously observed during fasting may contribute to attenuated FAA in Mc3rKO. AgRP and Npy expression measured 1 hour before food presentation correlated positively with FAA. Absence of Mc3rs (but not Ghsrs) was associated with lower AgRP/Npy expression, suggesting attenuated responses to signals of negative energy balance. These observations support the importance of Mc3rs as modulators of anticipatory responses to feeding, with mice able to compensate for loss of Ghsrs. The behavioral deficits of Mc3rKO displayed during RF may be partially explained by reduced hunger sensations owing to abnormal regulation of orexigenic AgRP/Npy neurons. PMID:25211592

  17. Growth rate controlled synthesis of hierarchical Bi2S3/In2S3 core/shell microspheres with enhanced photocatalytic activity.

    PubMed

    Zhou, Juan; Tian, Guohui; Chen, Yajie; Shi, Yunhan; Tian, Chungui; Pan, Kai; Fu, Honggang

    2014-02-07

    Core/shell heterostructure composite has great potential applications in photocatalytic field because the introduction of core can remarkably improve charge transport and enhance the electron-hole separation. Herein, hierarchical Bi2S3/In2S3 core/shell structured microspheres were prepared via a simple one-pot hydrothermal process based on different growth rate of the two kinds of sulphides. The results showed that, the as-prepared hierarchical Bi2S3/In2S3 core/shell heterostructure exhibits significant visible light photocatalytic activity for degradation of 2, 4-dichlorophenol. The introduction of Bi2S3 core can not only improve charge transport and enhance the electron-hole separation, but also broaden the visible light response. The hierarchical porous folwer-like shell of In2S3 could increase the specific surface area and remarkably enhanced the chemical stability of Bi2S3 against oxidation.

  18. Growth rate controlled synthesis of hierarchical Bi2S3/In2S3 core/shell microspheres with enhanced photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Zhou, Juan; Tian, Guohui; Chen, Yajie; Shi, Yunhan; Tian, Chungui; Pan, Kai; Fu, Honggang

    2014-02-01

    Core/shell heterostructure composite has great potential applications in photocatalytic field because the introduction of core can remarkably improve charge transport and enhance the electron-hole separation. Herein, hierarchical Bi2S3/In2S3 core/shell structured microspheres were prepared via a simple one-pot hydrothermal process based on different growth rate of the two kinds of sulphides. The results showed that, the as-prepared hierarchical Bi2S3/In2S3 core/shell heterostructure exhibits significant visible light photocatalytic activity for degradation of 2, 4-dichlorophenol. The introduction of Bi2S3 core can not only improve charge transport and enhance the electron-hole separation, but also broaden the visible light response. The hierarchical porous folwer-like shell of In2S3 could increase the specific surface area and remarkably enhanced the chemical stability of Bi2S3 against oxidation.

  19. Growth rate controlled synthesis of hierarchical Bi2S3/In2S3 core/shell microspheres with enhanced photocatalytic activity

    PubMed Central

    Zhou, Juan; Tian, Guohui; Chen, Yajie; Shi, Yunhan; Tian, Chungui; Pan, Kai; Fu, Honggang

    2014-01-01

    Core/shell heterostructure composite has great potential applications in photocatalytic field because the introduction of core can remarkably improve charge transport and enhance the electron-hole separation. Herein, hierarchical Bi2S3/In2S3 core/shell structured microspheres were prepared via a simple one-pot hydrothermal process based on different growth rate of the two kinds of sulphides. The results showed that, the as-prepared hierarchical Bi2S3/In2S3 core/shell heterostructure exhibits significant visible light photocatalytic activity for degradation of 2, 4-dichlorophenol. The introduction of Bi2S3 core can not only improve charge transport and enhance the electron-hole separation, but also broaden the visible light response. The hierarchical porous folwer-like shell of In2S3 could increase the specific surface area and remarkably enhanced the chemical stability of Bi2S3 against oxidation. PMID:24504084

  20. Etudes des verres du pseudo-ternaire La 2S 3Bi 2S 3Ga 2S 3, en relation avec le diagramme de phases et la spectroscopie infra-rouge

    NASA Astrophysics Data System (ADS)

    Ecrepont, C.; Guittard, M.; Barnier, S.; Loireau-Lozac'h, A. M.; Palazzi, M.; Julien, C.; Massot, M.

    1992-04-01

    The phase diagram of the La 2S 3Ga 2S 3Bi 2S 3 ternary system is described. DTA measurements have been carried out on a large variety of glass, and the glass formation domain has been defined with the investigation of Tg, Tc, and the endothermic peaks. Infrared absorption spectra have been studied. The vibrational assignment is discussed in relation to the composition of the glass.

  1. High temperature regenerative H.sub.2 S sorbents

    NASA Technical Reports Server (NTRS)

    Flytani-Stephanopoulos, Maria (Inventor); Gavalas, George R. (Inventor); Tamhankar, Satish S. (Inventor)

    1988-01-01

    Efficient, regenerable sorbents for removal of H.sub.2 S from high temperature gas streams comprise porous, high surface area particles. A first class of sorbents comprise a thin film of binary oxides that form a eutectic at the temperature of the gas stream coated onto a porous, high surface area refractory support. The binary oxides are a mixture of a Group VB or VIB metal oxide with a Group IB, IIB or VIII metal oxide such as a film of V-Zn-O, V-Cu-O, Cu-Mo-O, Zn-Mo-O or Fe-Mo-O coated on an alumina support. A second class of sorbents consist of particles of unsupported mixed oxides in the form of highly dispersed solid solutions of solid compounds characterized by small crystallite size, high porosity and relatively high surface area. The mixed oxide sorbents contain one Group IB, IIB or VIIB metal oxide such as copper, zinc or manganese and one or more oxides of Groups IIIA, VIB or VII such as aluminum, iron or molybdenum. The presence of iron or aluminum maintains the Group IB, IIB or VIIB metal in its oxidized state. Presence of molybdenum results in eutectic formation at sulfidation temperature and improves the efficiency of the sorbent.

  2. Raman and infrared spectra of stibnite, Sb2S3

    NASA Astrophysics Data System (ADS)

    Ilinca, G.; Caracas, R.

    2006-12-01

    Stibnite, Sb2S3 is a small-gap quasi-one-dimensional semiconductor (PhChMin, 32, 295-300, 2005) and a structural archetype for a variety of sulfide and sulfosalt minerals. Despite its widespread natural occurrence and its mineralogical importance, the physical properties are barely studied. Here, we combine experimental and theoretical approaches to analyze its zone-center dynamical properties. We measure the powder infrared reflectivity spectra and the powder Raman spectra under ambient conditions of pressure and temperature. We calculate the normal mode frequencies within the density functional perturbation theory, as implemented in the ABINIT package. With 20 atoms in the unit cell, stibnite has 60 normal modes, which according to the group theory decompose in Gamma as 10A_g+5B1g+10B2g+5B3g + 5A_u+10B1u+5B2u+10B3u. The acoustic modes have characters B1u+B2u+B3u. The Au modes are silent whereas all the other modes are active. The optical modes are distributed over a narrow 0-350 cm-1 frequency range. The infrared reflectivity spectrum shows a multitude of peaks, which are poorly differentiated and highly overlapping. The Raman spectrum is better differentiated, with five main peaks. The main infrared mode lays around 246 cm-1 and represents a superposition of at least one B3u and one B1u modes.

  3. Effects of H2S on molten carbonate fuel cells

    NASA Astrophysics Data System (ADS)

    Remick, R. J.

    1985-03-01

    This report summarizes work accomplished to identify the poisoning mechanism(s) responsible for performance losses of molten carbonate fuel cells (MCFC) when operating on sulfur-containing gases. This objective is being addressed by focusing out-of-cell and in-cell experiments on single mechanistic issues, followed by incorporation of the results into a model that correlates cell potential decline to contaminant(s) concentration. When coupled with gas cleanup cost projections, the model can be used to conduct trade-off studies leading to the selection of optimum feed-gas compositions for MCFC power plants. The importance of this program is that the degree to which H2S and other contaminants must be removed from typical MCFC fuels can have a profound effect on the cost of cleaning the fuel gas, especially if contaminant levels lower than 0.1 ppM are required. The anticipated product from the overall program is a justifiable specification for gas cleanup requirements for MCFC power plants. The loss in performance experienced by fuel cells operating on contaminated fuels has been traced to the electrochemical formation of a layer of nickel sulfide on the fuel cell electrode.

  4. Neomorphic Mutations in PIK3R1 Confer Sensitivity to MAPK Inhibitors due to Activation of ERK and JNK Pathways | Office of Cancer Genomics

    Cancer.gov

    In a recent publication in Cancer Cell, CTD2 investigators discovered that a known cancer-associated gain-of-function alteration in phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) results in novel protein activity that confers sensitivity to mitogen-activated protein kinase (MAPK) inhibitors. The PIK3R1 gene encodes the p85α regulatory subunit of PIK3. Under normal conditions, p85α suppresses PIK3 mediated activation of downstream pathways that promote cell growth and survival.

  5. On the Fermi-GBM Event 0.4 s after GW150914

    NASA Astrophysics Data System (ADS)

    Greiner, J.; Burgess, J. M.; Savchenko, V.; Yu, H.-F.

    2016-08-01

    In view of the recent report by Connaughton et al., we analyze continuous time-tagged event (TTE) data of Fermi-gamma-ray burst monitor (GBM) around the time of the gravitational-wave event GW 150914. We find that after proper accounting for low-count statistics, the GBM transient event at 0.4 s after GW 150914 is likely not due to an astrophysical source, but consistent with a background fluctuation, removing the tension between the INTEGRAL/ACS non-detection and GBM. Additionally, reanalysis of other short GRBs shows that without proper statistical modeling the fluence of faint events is over-predicted, as verified for some joint GBM-ACS detections of short GRBs. We detail the statistical procedure to correct these biases. As a result, faint short GRBs, verified by ACS detections, with significances in the broadband light curve even smaller than that of the GBM-GW150914 event are recovered as proper non-zero source, while the GBM-GW150914 event is consistent with zero fluence.

  6. Highly active metallocarboxypeptidase from newly isolated Geobacillus strain SBS-4S: cloning and characterization.

    PubMed

    Tayyab, Muhammad; Rashid, Naeem; Angkawidjaja, Clement; Kanaya, Shigenori; Akhtar, Muhammad

    2011-03-01

    The carboxypeptidase gene from Geobacillus SBS-4S was cloned and sequenced. The sequence analysis displayed the gene consists of an open reading frame of 1503 nucleotides encoding a protein of 500 amino acids (CBP(SBS)). The amino acid sequence comparison revealed that CBP(SBS) exhibited a highest homology of 41.6% (identity) with carboxypeptidase Taq from Thermus aquaticus among the characterized proteases. CBP(SBS) contained an active site motif (265)HEXXH(269) which is conserved in family-M32 of carboxypeptidases. The gene was expressed with His-Tag utilizing Escherichia coli expression system and purified to apparent homogeneity. The purified CBP(SBS) showed highest activity at pH 7.5 and 70°C. The enzyme activity was metal ion dependent. Among metal ions highest activity was found in the presence of Co(2+). Thermostability studies of CBP(SBS) by circular dichroism spectroscopy demonstrated the melting temperature of the protein around 77°C. The enzyme exhibited K(m) and V(max) values of 14 mM and 10526 μmol min(-1) mg(-1) when carbobenzoxy-alanine-arginine was used as substrate. k(cat) and k(cat)/K(m) valves were 10175 s(-1) and 726 mM(-1) s(-1). To our knowledge this is the highest ever reported enzyme activity of a metallocarboxypeptidase and the first characterization of a metallocarboxypeptidase from genus Geobacillus.

  7. Exchange anisotropy in the skyrmion host GaV4S8

    NASA Astrophysics Data System (ADS)

    Ehlers, D.; Stasinopoulos, I.; Kézsmárki, I.; Fehér, T.; Tsurkan, V.; Krug von Nidda, H.-A.; Grundler, D.; Loidl, A.

    2017-02-01

    Using ferromagnetic resonance spectroscopy at 34 GHz we explored the magnetic anisotropy of single-crystalline GaV4S8 in the field-polarized magnetic state. We describe the data in terms of an easy-axis type uniaxial anisotropy with an anisotropy constant {{K}1}=1.6\\cdot {{10}5} erg cm-3 at 2 K, corresponding to a relative exchange anisotropy Δ J/J≈ 5 %, and about 1.0\\cdot {{10}5}~ erg cm-3 near 11 K, i.e. at temperatures where the skyrmion-lattice phase was recently discovered. The relatively large value of K 1 explains the confinement of the skyrmion tubes to the < 1 1 1> easy axes. A distinct set of resonances in the spectra is attributed to the co-existence of different rhombohedral domains. Complementary broadband spectroscopy demonstrates that non-collinear spin states may sensitively be detected by electron spin resonance techniques.

  8. Structural principles for computational and de novo design of 4Fe-4S metalloproteins.

    PubMed

    Nanda, Vikas; Senn, Stefan; Pike, Douglas H; Rodriguez-Granillo, Agustina; Hansen, Will A; Khare, Sagar D; Noy, Dror

    2016-05-01

    Iron-sulfur centers in metalloproteins can access multiple oxidation states over a broad range of potentials, allowing them to participate in a variety of electron transfer reactions and serving as catalysts for high-energy redox processes. The nitrogenase FeMoCO cluster converts di-nitrogen to ammonia in an eight-electron transfer step. The 2(Fe4S4) containing bacterial ferredoxin is an evolutionarily ancient metalloprotein fold and is thought to be a primordial progenitor of extant oxidoreductases. Controlling chemical transformations mediated by iron-sulfur centers such as nitrogen fixation, hydrogen production as well as electron transfer reactions involved in photosynthesis are of tremendous importance for sustainable chemistry and energy production initiatives. As such, there is significant interest in the design of iron-sulfur proteins as minimal models to gain fundamental understanding of complex natural systems and as lead-molecules for industrial and energy applications. Herein, we discuss salient structural characteristics of natural iron-sulfur proteins and how they guide principles for design. Model structures of past designs are analyzed in the context of these principles and potential directions for enhanced designs are presented, and new areas of iron-sulfur protein design are proposed. This article is part of a Special issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, protein networks, edited by Ronald L. Koder and J.L Ross Anderson.

  9. Structural, magnetic, electric, dielectric, and thermodynamic properties of multiferroic Ge V4S8

    NASA Astrophysics Data System (ADS)

    Widmann, S.; Günther, A.; Ruff, E.; Tsurkan, V.; Krug von Nidda, H.-A.; Lunkenheimer, P.; Loidl, A.

    2016-12-01

    The lacunar spinel Ge V4S8 undergoes orbital and ferroelectric ordering at the Jahn-Teller transition around 30 K and exhibits antiferromagnetic order below about 14 K. In addition to this orbitally driven ferroelectricity, lacunar spinels are an interesting material class, as the vanadium ions form V4 clusters representing stable molecular entities with a common electron distribution and a well-defined level scheme of molecular states resulting in a unique spin state per V4 molecule. Here we report detailed x-ray, magnetic susceptibility, electrical resistivity, heat capacity, thermal expansion, and dielectric results to characterize the structural, electric, dielectric, magnetic, and thermodynamic properties of this interesting material, which also exhibits strong electronic correlations. From the magnetic susceptibility, we determine a negative Curie-Weiss temperature, indicative for antiferromagnetic exchange and a paramagnetic moment close to a spin S =1 of the V4 molecular clusters. The low-temperature heat capacity provides experimental evidence for gapped magnon excitations. From the entropy release, we conclude about strong correlations between magnetic order and lattice distortions. In addition, the observed anomalies at the phase transitions also indicate strong coupling between structural and electronic degrees of freedom. Utilizing dielectric spectroscopy, we find the onset of significant dispersion effects at the polar Jahn-Teller transition. The dispersion becomes fully suppressed again with the onset of spin order. In addition, the temperature dependencies of dielectric constant and specific heat possibly indicate a sequential appearance of orbital and polar order.

  10. Structural principles for computational and de novo design of 4Fe-4S metalloproteins

    PubMed Central

    Nanda, Vikas; Senn, Stefan; Pike, Douglas H.; Rodriguez-Granillo, Agustina; Hansen, Will; Khare, Sagar D.; Noy, Dror

    2017-01-01

    Iron-sulfur centers in metalloproteins can access multiple oxidation states over a broad range of potentials, allowing them to participate in a variety of electron transfer reactions and serving as catalysts for high-energy redox processes. The nitrogenase FeMoCO cluster converts di-nitrogen to ammonia in an eight-electron transfer step. The 2(Fe4S4) containing bacterial ferredoxin is an evolutionarily ancient metalloprotein fold and is thought to be a primordial progenitor of extant oxidoreductases. Controlling chemical transformations mediated by iron-sulfur centers such as nitrogen fixation, hydrogen production as well as electron transfer reactions involved in photosynthesis are of tremendous importance for sustainable chemistry and energy production initiatives. As such, there is significant interest in the design of iron-sulfur proteins as minimal models to gain fundamental understanding of complex natural systems and as lead-molecules for industrial and energy applications. Herein, we discuss salient structural characteristics of natural iron-sulfur proteins and how they guide principles for design. Model structures of past designs are analyzed in the context of these principles and potential directions for enhanced designs are presented, and new areas of iron-sulfur protein design are proposed. PMID:26449207

  11. Extending the Family of V(4+) S=(1/2) Kagome Antiferromagnets.

    PubMed

    Clark, Lucy; Aidoudi, Farida H; Black, Cameron; Arachchige, Kasun S A; Slawin, Alexandra M Z; Morris, Russell E; Lightfoot, Philip

    2015-12-14

    The ionothermal synthesis, structure, and magnetic susceptibility of a novel inorganic-organic hybrid material, imidazolium vanadium(III,IV) oxyfluoride [C3 H5 N2 ][V9 O6 F24 (H2 O)2 ] (ImVOF) are presented. The structure consists of inorganic vanadium oxyfluoride slabs with kagome layers of V(4+) S=${{ 1/2 }}$ ions separated by a mixed valence layer. These inorganic slabs are intercalated with imidazolium cations. Quinuclidinium (Q) and pyrazinium (Pyz) cations can also be incorporated into the hybrid structure type to give QVOF and PyzVOF analogues, respectively. The highly frustrated topology of the inorganic slabs, along with the quantum nature of the magnetism associated with V(4+) , means that these materials are excellent candidates to host exotic magnetic ground states, such as the highly sought quantum spin liquid. Magnetic susceptibility measurements of all samples suggest an absence of conventional long-range magnetic order down to 2 K despite considerable antiferromagnetic exchange.

  12. Observation of e+e-→χc 0ω and missing higher charmonium ψ (4 S )

    NASA Astrophysics Data System (ADS)

    Chen, Dian-Yong; Liu, Xiang; Matsuki, Takayuki

    2015-05-01

    Stimulated by the recent BESIII observation of a new resonance in e+e-→ω χc 0 which is consistent with our predicted ψ (4 S ), we estimate the meson loop contribution to ψ (4 S )→ω χc 0 in this work. The evaluation indicates that our theoretical estimate can overlap with the experimental data in a reasonable parameter range. This fact shows that introduction of the missing higher charmonium ψ (4 S ) provides a possible explanation to the recent BESIII observation. The upper limit of a branching ratio of ψ (4 S )→η J /ψ is also predicted to be 1.9 ×10-3 , which can be further tested by BESIII, Belle, and forthcoming BelleII.

  13. Spin Disorder and Order in Quasi-2D Triangular Heisenberg Antiferromagnets: Comparative Study of FeGa2S4, Fe2Ga2S5, and NiGa2S4

    NASA Astrophysics Data System (ADS)

    Nakatsuji, S.; Tonomura, H.; Onuma, K.; Nambu, Y.; Sakai, O.; Maeno, Y.; Macaluso, R. T.; Chan, Julia Y.

    2007-10-01

    Our single crystal study reveals that the single-layer S=2 triangular Heisenberg antiferromagnet FeGa2S4 forms a frozen spin-disordered state, similar to the S=1 isostructural magnet NiGa2S4. In this state, the magnetic specific heat CM is not only insensitive to the field, but shows a T2 dependence that scales to CM of NiGa2S4, suggesting the same underlying mechanism of the 2D coherent behavior. In contrast, the bilayer system Fe2Ga2S5 exhibits a 3D antiferromagnetic order.

  14. Electronic structure of H2S, SF2, and HSF and implications for hydrogen-substituted hypervalent sulfur fluorides.

    PubMed

    Lindquist, Beth A; Woon, David E; Dunning, Thom H

    2014-02-20

    It is well known that hypervalent molecules are more stable with very electronegative ligands such as fluorine. For example, while SF6 is uniquely stable and experimentally well characterized and many of the features of SF4 have been characterized, neither H4S nor H6S has been observed. Furthermore, no hypervalent sulfur species with mixed hydrogen and fluorine ligands have been experimentally characterized to date. In this work, we present detailed calculations of the electronic structure of H2S, SF2, and HSF. While all three compounds have similar bent singlet ground states, the potential energy surfaces of various low lying electronic states as a function of bond angle reveal very different behaviors, in particular for linear geometries. We use the disparate bonding motifs of the low-lying triplet states to rationalize the differences between SF4 and the hypothetical H4S molecule. We also make predictions about the effects of hydrogen substitution on the energetics and geometries of hypervalent sulfur fluoride compounds.

  15. Classified Computer Configuration Control System (C{sup 4}S), Revision 3, Database Administrator`s Guide

    SciTech Connect

    O`Callaghan, P.B.; Nelson, R.A.; Grambihler, A.J.

    1994-04-01

    This document provides a guide for database administration and specific information for the Classified Computer Configuration Control System (C{sup 4}S). As a guide, this document discusses required database administration functions for the set up of database tables and for users of the system. It is assumed that general and user information has been obtained from the Classified Computer Configuration Control System (C{sup 4}S), Revision 3, User`s Information (WHC 1994).

  16. Structural and magnetic phase transitions of the orthovanadates RVO3 (R= Dy, Ho, Er) as seen via neutron diffraction

    NASA Astrophysics Data System (ADS)

    Reehuis, M.; Ulrich, C.; Prokeš, K.; Mat'aš, S.; Fujioka, J.; Miyasaka, S.; Tokura, Y.; Keimer, B.

    2011-02-01

    The structural and magnetic phase behavior of RVO3 with R=v Dy, Ho, and Er was studied by single-crystal neutron diffraction. Upon cooling, all three compounds show structural transitions from orthorhombic (space group Pbnm) to monoclinic (p21/b) symmetry due to the onset of orbital order at T= 188-200 K, followed by Néel transitions at T= 110-113 K due to the onset of antiferromagnetic (C-type) order of the vanadium moments. Upon further cooling, additional structural phase transitions occur for DyVO3 and ErVO3 at 60 and 56 K, respectively, where the monoclinic structure changes to an orthorhombic structure with the space group Pbnm, and the magnetic order of the V sublattice changes to a G-type structure. These transition temperatures are reduced compared to the ones previously observed for nonmagnetic R3+ ions due to exchange interactions between the V3+ and R3+ ions. For ErVO3, R-R exchange interactions drive a transition to collinear magnetic order at T= 2.5 K. For HoVO3, the onset of noncollinear, weakly ferromagnetic order of the Ho moments nearly coincides with the structural phase transition from the monoclinic to the low-temperature orthorhombic structure. This transition is characterized by an extended hysteresis between 24 and 36 K. The Dy moments in DyVO3 also exhibit noncollinear, weakly ferromagnetic order upon cooling below 13 K. With increasing temperature, the monoclinic structure of DyVO3 reappears in the temperature range between 13 and 23 K. This reentrant structural transition is associated with a rearrangement of the Dy moments. A group theoretical analysis showed that the observed magnetic states of the R3+ ions are compatible with the lattice structure. The results are discussed in the light of recent data on the magnetic field dependence of the lattice structure and magnetization of DyVO3 and HoVO3.

  17. Docking pose selection by interaction pattern graph similarity: application to the D3R grand challenge 2015

    NASA Astrophysics Data System (ADS)

    Slynko, Inna; Da Silva, Franck; Bret, Guillaume; Rognan, Didier

    2016-09-01

    High affinity ligands for a given target tend to share key molecular interactions with important anchoring amino acids and therefore often present quite conserved interaction patterns. This simple concept was formalized in a topological knowledge-based scoring function (GRIM) for selecting the most appropriate docking poses from previously X-rayed interaction patterns. GRIM first converts protein-ligand atomic coordinates (docking poses) into a simple 3D graph describing the corresponding interaction pattern. In a second step, proposed graphs are compared to that found from template structures in the Protein Data Bank. Last, all docking poses are rescored according to an empirical score (GRIMscore) accounting for overlap of maximum common subgraphs. Taking the opportunity of the public D3R Grand Challenge 2015, GRIM was used to rescore docking poses for 36 ligands (6 HSP90α inhibitors, 30 MAP4K4 inhibitors) prior to the release of the corresponding protein-ligand X-ray structures. When applied to the HSP90α dataset, for which many protein-ligand X-ray structures are already available, GRIM provided very high quality solutions (mean rmsd = 1.06 Å, n = 6) as top-ranked poses, and significantly outperformed a state-of-the-art scoring function. In the case of MAP4K4 inhibitors, for which preexisting 3D knowledge is scarce and chemical diversity is much larger, the accuracy of GRIM poses decays (mean rmsd = 3.18 Å, n = 30) although GRIM still outperforms an energy-based scoring function. GRIM rescoring appears to be quite robust with comparison to the other approaches competing for the same challenge (42 submissions for the HSP90 dataset, 27 for the MAP4K4 dataset) as it ranked 3rd and 2nd respectively, for the two investigated datasets. The rescoring method is quite simple to implement, independent on a docking engine, and applicable to any target for which at least one holo X-ray structure is available.

  18. Pb- and Sm-doping effects on the vortex dynamics in Bi4O4S3 superconductor

    NASA Astrophysics Data System (ADS)

    Xie, L.; Tie, X. Y.; Zhang, H. G.

    2017-01-01

    Polycrystalline samples of Bi4O4S3, Bi3.94Pb0.06O4S3, and Bi3.94Sm0.06O4S3 were synthesized using a conventional solid-state reaction method. The vortex dynamics of these samples are studied and compared through measuring the critical current density (Jc) and magnetic relaxation. The estimated Jc value of three samples at temperature 2 K decreases with doping Pb and Sm elements due to the depression of the superconductivity. The normalized pinning force response with reduced field follows the Kramer scaling law f (h )∝ hp(1-h ) q , and the maximum of the reduced field (hmax) is observed at 0.31, 0.24, and 0.18 for Bi4O4S3, Bi3.94Pb0.06O4S3, and Bi3.94Sm0.06O4S3, respectively, indicating the presence of both surface and point pinning centers in these samples. The barrier energy estimated by the magnetic relaxation data depends on the field as a negative power law U0∝Hn and the magnetic relaxation rate S exhibits a considerable monotonic increase with magnetic field, which corroborates a plastic nature of the creep vortex dynamics in these compounds.

  19. The turbomachine blading design using S2-S1 approach

    NASA Technical Reports Server (NTRS)

    Luu, T. S.; Bencherif, L.; Viney, B.; Duc, J. M. Nguyen

    1991-01-01

    The boundary conditions corresponding to the design problem when the blades being simulated by the bound vorticity distribution are presented. The 3D flow is analyzed by the two steps S2 - S1 approach. In the first step, the number of blades is supposed to be infinite, the vortex distribution is transformed into an axisymmetric one, so that the flow field can be analyzed in a meridional plane. The thickness distribution of the blade producing the flow channel striction is taken into account by the modification of metric tensor in the continuity equation. Using the meridional stream function to define the flow field, the mass conservation is satisfied automatically. The governing equation is deduced from the relation between the azimuthal component of the vorticity and the meridional velocity. The value of the azimuthal component of the vorticity is provided by the hub to shroud equilibrium condition. This step leads to the determination of the axisymmetric stream sheets as well as the approximate camber surface of the blade. In the second step, the finite number of blades is taken into account, the inverse problem corresponding to the blade to blade flow confined in each stream sheet is analyzed. The momentum equation implies that the free vortex of the absolute velocity must be tangential to the stream sheet. The governing equation for the blade to blade flow stream function is deduced from this condition. At the beginning, the upper and the lower surfaces of the blades are created from the camber surface obtained from the first step with the assigned thickness distribution. The bound vorticity distribution and the penetrating flux conservation applied on the presumed blade surface constitute the boundary conditions of the inverse problem. The detection of this flux leads to the rectification of the geometry of the blades.

  20. Role of chlorine in In2S3 for band alignment at nanoporous-TiO2/In2S3 interfaces

    NASA Astrophysics Data System (ADS)

    Owino Juma, Albert; Azarpira, Anahita; Steigert, Alexander; Pomaska, Manuel; Fischer, Christian-Herbert; Lauermann, Iver; Dittrich, Thomas

    2013-08-01

    Coatings of Cl-free and Cl-containing In2S3 (In2S3:Cl) layers were prepared by spray ion layer gas reaction on nanoporous TiO2 (np-TiO2). Charge separation in FTO/np-TiO2/In2S3:Cl, FTO/In2S3:Cl, FTO/np-TiO2/In2S3:acac, and FTO/In2S3:acac systems has been investigated by modulated surface photovoltage spectroscopy (SPV). The exponential defect tails below the band gap of In2S3 were reduced for In2S3:Cl. The analysis of the SPV spectra allowed to distinguish different mechanisms of charge separation and to deduce the conduction band offsets (about 0.3 eV and 0.05 eV for np-TiO2/In2S3:Cl and np-TiO2/In2S3:acac, respectively) in correlation with photoelectron measurements.

  1. Captopril partially decreases the effect of H(2)S on rat blood pressure and inhibits H(2)S-induced nitric oxide release from S-nitrosoglutathione.

    PubMed

    Drobná, M; Misak, A; Holland, T; Kristek, F; Grman, M; Tomasova, L; Berenyiova, A; Cacanyiova, S; Ondrias, K

    2015-01-01

    We studied the effects of the H(2)S donor Na(2)S on the mean arterial blood pressure (MAP) and heart and breathing rates of anesthetized Wistar rats in the presence and absence of captopril. Bolus administration of Na(2)S (1-4 micromol/kg) into the right jugular vein transiently decreased heart and increased breathing rates; at 8-30 micromol/kg, Na(2)S had a biphasic effect, transiently decreasing and increasing MAP, while transiently decreasing heart rate and increasing and decreasing breathing rate. These results may indicate independent mechanisms by which H(2)S influences MAP and heart and breathing rates. The effect of Na(2)S in decreasing MAP was less pronounced in the presence of captopril (2 micromol/l), which may indicate that the renin-angiotensin system is partially involved in the Na(2)S effect. Captopril decreased H(2)S-induced NO release from S-nitrosoglutathione, which may be related to some biological activities of H(2)S. These results contribute to the understanding of the effects of H(2)S on the cardiovascular system.

  2. Synthesis, Structure, and Characterization of Cu4S10(4-methylpyridine)4

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Richman, Robert M.; Duraj, Stan A.; Andras, Maria T.; Moore, Hall L.; Sabat, Michal; Eckles, William E.; Martuch, Robert A.

    1996-01-01

    The title compound, Cu4S10(4-methylpyridine)(sub 4) (dot) 4-methylpyridine was prepared by three different reactions: the oxidation of copper powder by sulfur and the reaction of copper (I) sulfide (or CuBr (dot) SMe2) with excess sulfur, both in the coordinating solvent, 4-methylpyridine. Red crystals of the compound obtained by layering with hexanes were subjected to single crystal X-ray diffraction. The structure was refined to R = 0.026 and R(sub w) = 0.036 in a space group P1bar (No. 2), with Z = 2, a = 13.983 (2) A, b = 15.384 (2) A, c = 9.660 (1) A, alpha = 93.87 (1)deg., beta = 93.38 (1)deg., gamma = 99.78 (1)deg., V = 2037.9 (9) A(exp 3). The compound has approximate S(sub 4) symmetry and consists of two pentasulfide chains linking four Cu(I) ions, each with a corrdinating 2-methylpyridine. The infrared spectrum was dominated by absorption due to coordinated 4-methylpyridine with several low-energy peaks attributable to S-S stretches, which were also observed by Raman spectroscopy. A featureless electronic absorption spectrum yielded a single peak in the near ultraviolet upon computer enhancement (lambda = 334 nm, epsilon = 10,000), most likely an intraligand transition. Cyclic voltammetry indicates that the polysulfide complex undergoes irrversible oxidation and reduction at +0.04 and -0.34 V vs. SCE, respectively, at 298 K in 4-methylpyridine when swept at 20 mV/sec. The electrochemical behavior was unvaried even at sweep rates as high as 100 V/sec.

  3. Tetrahedral Clusters of GaMo 4S 8-Type Compounds: A Metal Bonding Analysis

    NASA Astrophysics Data System (ADS)

    Le Beuze, A.; Loirat, H.; Zerrouki, M. C.; Lissillour, R.

    1995-11-01

    Extended Hückel tight binding calculations have been performed on ligated as well as on ligand-free Mo4 and Mo6 extended frames, in order to analyze the metal-metal bonding within the clusters and particularly the appreciable changes of the metal-metal bond lengths through the M4 tetrahedral units contained in GaM4X8 (M = Mo, Nb, V, Ta; X = S, Se, Te), Mo4S4Y4 (Y = Cl, Br, I). A comparison with the M6 octahedral units of the M Mo6X8 (M = Pb, Ag, La; X = S, Se) series is made. By means of DOS, COOP curves, and overlap populations, results clearly display the strong reorganization of the electronic structure of the bare metal clusters network while the ligand interactions occur, inducing a strong reduction of the strength of the metal-metal bonds. We outline the relationship between the metal-metal bond lengths and various parameters such as the valence electron count (VEC) per cluster and the nature of the ligands. Our results indicate that the two series M4 and M6 differ: M-M bond lengths are unaffected by the VEC in the regular M4 cluster, whereas some M-M bond lengths undergo a significant change when the VEC increases in the distorded M6 clusters. Likewise, it is worthy to note that metal d orbitals have a more significant effect in M4 cluster series. In contrast, the metal-ligand covalency induces similar elongations of metal-metal bonds in the two series.

  4. Interaction transfer of silicon atoms forming Co silicide for Co/√(3)×√(3)R30°-Ag/Si(111) and related magnetic properties

    SciTech Connect

    Chang, Cheng-Hsun-Tony; Fu, Tsu-Yi; Tsay, Jyh-Shen

    2015-05-07

    Combined scanning tunneling microscopy, Auger electron spectroscopy, and surface magneto-optic Kerr effect studies were employed to study the microscopic structures and magnetic properties for ultrathin Co/√(3)×√(3)R30°-Ag/Si(111). As the annealing temperature increases, the upward diffusion of Si atoms and formation of Co silicides occurs at temperature above 400 K. Below 600 K, the √(3)×√(3)R30°-Ag/Si(111) surface structure persists. We propose an interaction transferring mechanism of Si atoms across the √(3)×√(3)R30°-Ag layer. The upward transferred Si atoms react with Co atoms to form Co silicide. The step height across the edge of the island, a separation of 0.75 nm from the analysis of the 2 × 2 structure, and the calculations of the normalized Auger signal serve as strong evidences for the formation of CoSi{sub 2} at the interface. The interaction transferring mechanism for Si atoms enhances the possibility of interactions between Co and Si atoms. The smoothness of the surface is advantage for that the easy axis of magnetization for Co/√(3)×√(3)R30°-Ag/Si(111) is in the surface plane. This provides a possible way of growing flat magnetic layers on silicon substrate with controllable silicide formation and shows potential applications in spintronics devices.

  5. The Effect of DRA and SQ3R on the Immediate and Delayed Recall of Seventh-Grade Social Studies Material.

    ERIC Educational Resources Information Center

    Garty, Roberta H.

    The purpose of this study was to examine the effect of the study of organizers, directed reading activity (DRA) and SQ3R, on the immediate and delayed recall of social studies materials. Eighty-four seventh-grade students from an intermediate school participated in this study. The results of the study indicated that the DRA technique was an…

  6. Regulatory acceptance and use of 3R models for pharmaceuticals and chemicals: expert opinions on the state of affairs and the way forward.

    PubMed

    Schiffelers, Marie-Jeanne W A; Blaauboer, Bas J; Bakker, Wieger E; Beken, Sonja; Hendriksen, Coenraad F M; Koëter, Herman B W M; Krul, Cyrille

    2014-06-01

    Pharmaceuticals and chemicals are subjected to regulatory safety testing accounting for approximately 25% of laboratory animal use in Europe. This testing meets various objections and has led to the development of a range of 3R models to Replace, Reduce or Refine the animal models. However, these models must overcome many barriers before being accepted for regulatory risk management purposes. This paper describes the barriers and drivers and options to optimize this acceptance process as identified by two expert panels, one on pharmaceuticals and one on chemicals. To untangle the complex acceptance process, the multilevel perspective on technology transitions is applied. This perspective defines influences at the micro-, meso- and macro level which need alignment to induce regulatory acceptance of a 3R model. This paper displays that there are many similar mechanisms within both sectors that prevent 3R models from becoming accepted for regulatory risk assessment and management. Shared barriers include the uncertainty about the value of the new 3R models (micro level), the lack of harmonization of regulatory requirements and acceptance criteria (meso level) and the high levels of risk aversion (macro level). In optimizing the process commitment, communication, cooperation and coordination are identified as critical drivers.

  7. MTSET modification of D4S6 cysteines stabilize the fast inactivated state of Nav1.5 sodium channels.

    PubMed

    O'Leary, Michael E; Chahine, Mohamed

    2015-01-01

    The transmembrane S6 segments of Na(+) sodium channels form the cytoplasmic entrance of the channel and line the internal aspects of the aqueous pore. This region of the channel has been implicated in Na(+) channel permeation, gating, and pharmacology. In this study we utilized cysteine substitutions and methanethiosulfonate reagent (MTSET) to investigate the role of the S6 segment of homologous domain 4 (D4S6) in the gating of the cardiac (Nav1.5) channel. D4S6 cysteine mutants were heterologously expressed in tsA201 cells and currents recorded using whole-cell patch clamp. Internal MTSET reduced the peak Na(+) currents, induced hyperpolarizing shifts in steady-state inactivation and slowed the recovery of mutant channels with cysteines inserted near the middle (F1760C, V1763C) and C-terminus (Y1767C) of the D4S6. These findings suggested a link between the MTSET inhibition and fast inactivation. This was confirmed by expressing the V1763C and Y1767C mutations in non-inactivating Nav1.5 channels. Removing inactivation abolished the MTSET inhibition of the V1763C and Y1767C mutants. The data indicate that the MTSET-induced reduction in current primarily results from slower recovery from inactivation that produces hyperpolarizing shifts in fast inactivation and decreases the steady-state availability of the channels. This contrasted with a cysteine inserted near the C-terminus of the D4S6 (I1770C) where MTSET increased the persistent Na(+) current at depolarized voltages consistent with impaired fast inactivation. Covalent modification of D4S6 cysteines with MTSET adduct appears to reduce the mobility of the D4S6 segment and stabilize the channels in the fast inactivated state. These findings indicate that residues located near the middle and C-terminus of the D4S6 play an important role in fast inactivation.

  8. Dispensability of the [4Fe-4S] cluster in novel homologues of adenine glycosylase MutY.

    PubMed

    Trasviña-Arenas, Carlos H; Lopez-Castillo, Laura M; Sanchez-Sandoval, Eugenia; Brieba, Luis G

    2016-02-01

    7,8-Dihydro-8-deoxyguanine (8oG) is one of the most common oxidative lesions in DNA. DNA polymerases misincorporate an adenine across from this lesion. Thus, 8oG is a highly mutagenic lesion responsible for G:C→T:A transversions. MutY is an adenine glycosylase, part of the base excision repair pathway that removes adenines, when mispaired with 8oG or guanine. Its catalytic domain includes a [4Fe-4S] cluster motif coordinated by cysteinyl ligands. When this cluster is absent, MutY activity is depleted and several studies concluded that the [4Fe-4S] cluster motif is an indispensable component for DNA binding, substrate recognition and enzymatic activity. In the present study, we identified 46 MutY homologues that lack the canonical cysteinyl ligands, suggesting an absence of the [4Fe-4S] cluster. A phylogenetic analysis groups these novel MutYs into two different clades. One clade is exclusive of the order Lactobacillales and another clade has a mixed composition of anaerobic and microaerophilic bacteria and species from the protozoan genus Entamoeba. Structural modeling and sequence analysis suggests that the loss of the [4Fe-4S] cluster is compensated by a convergent solution in which bulky amino acids substitute the [4Fe-4S] cluster. We functionally characterized MutYs from Lactobacillus brevis and Entamoeba histolytica as representative members from each clade and found that both enzymes are active adenine glycosylases. Furthermore, chimeric glycosylases, in which the [4Fe-4S] cluster of Escherichia coli MutY is replaced by the corresponding amino acids of LbY and EhY, are also active. Our data indicates that the [4Fe-4S] cluster plays a structural role in MutYs and evidences the existence of alternative functional solutions in nature.

  9. Impact of fluctuations in gaseous H2S concentrations on sulfide uptake by sewer concrete: The effect of high H2S loads.

    PubMed

    Sun, Xiaoyan; Jiang, Guangming; Bond, Philip L; Keller, Jurg

    2015-09-15

    The acid production from the oxidation of hydrogen sulfide (H2S) in sewer air results in serious corrosion of exposed concrete surfaces in sewers. Large fluctuations of gaseous H2S concentrations occur in sewers due to the diurnal profiles of sewage flow and retention times and the necessity of intermittent pumping of sewage from pressure pipes into gravity pipes. How the high concentrations of H2S due to these events may affect H2S uptake and subsequent corrosion by concrete sewers is largely unknown. This study determined the effect of short- and long-term increases in H2S levels on the sulfide uptake rate (SUR) of concrete surfaces with an active corrosion layer. The results showed that during the high load situation the SUR increased significantly but then decreased (compared to the baseline SUR) by about 7-14% and 41-50% immediately after short- and long-term H2S high-load periods, respectively. For both exposure conditions, the SUR gradually (over several hours) recovered to approximately 90% of the baseline SUR. Further tests suggest multiple factors may contribute to the observed decrease of SUR directly after the high H2S load. This includes the temporary storage of elemental sulfur in the corrosion layer and inhibition of sulfide oxidizing bacteria (SOB) due to high H2S level and temporary acid surge. Additionally, the delay of the corrosion layer to fully recover the SUR after the high H2S load suggests that there is a longer-term inhibitive effect of the high H2S levels on the activity of the SOB in the corrosion layer. Due to the observed activity reductions, concrete exposed to occasional short-term high H2S load periods had an overall lower H2S uptake compared to concrete exposed to constant H2S levels at the same average concentration. To accurately predict H2S uptake by sewer concrete and hence the likely maximum corrosion rates, a correction factor should be adopted for the H2S fluctuations when average H2S levels are used in the prediction.

  10. Système pseudo-ternaire Ag 2S-Ga 2S 3-GeS 2: Diagramme de phases—Domaine vitreux

    NASA Astrophysics Data System (ADS)

    Chbani, Noura; Loireau-Lozac'h, Anne-Marie; Rivet, Jacques; Dugué, Jérôme

    1995-06-01

    The phase diagram of the Ag2S-Ga2S3-GeS2 pseudo-ternary system has been studied using DTA and XRD experiments. Only one quaternary compound was observed: AgGaGeS4, which presents a binary peritectic-type decomposition at 840°C. Four ternary invariants were found: two eutectics and two peritectics. The phase diagrams of the following systems are described: Ag2S-Ga2S3, AgGaS2-GaS2, Ga2S3-AgGaGeS4, AgGaGeS4-Ag8GeS6, and Ag9GaS6-Ag8GeS6. The system shows a large-sized glassy domain resulting from glasses of the GeS2-Ga2S3 and GeS2-Ag2S binary systems, which does not reach the Ga2S3-Ag2S quasi binary system. Glass transition Tg and crystallization Tc temperatures decreased as silver content increased.

  11. Solvothermal synthesis, crystal structure and properties of [Mn(C 6H 18N 4)] 4Mn 2Sb 4S 12 containing the new hetero-metallic [Mn 2Sb 4S 12] core

    NASA Astrophysics Data System (ADS)

    Schaefer, Michael; Näther, Christian; Bensch, Wolfgang

    2003-08-01

    The novel thioantimonate(III) [Mn(C 6H 18N 4)] 4Mn 2Sb 4S 12 was synthesised under solvothermal conditions by reacting Mn, Sb and S in an aqueous solution of tren (=tris(2-aminoethyl)amine). In the structure MnS 4 tetrahedra and SbS 3 pyramids are linked via common corners and edges to form a new hetero-metallic [Mn 2Sb 4S 12] core. The [Mn(C 6H 18N 4)] 2+ cations are located at the periphery of the core and are bound to the [Mn 2Sb 4S 12] unit via two S atoms. Interesting features of the structure are two large angles around S atoms connecting neighboured MnS 4 tetrahedra. The competition between interatomic bonding interactions and steric requirements are responsible for this observation. The thermal decomposition proceeds in one step involving a complex redox reaction.

  12. [Sequence and antigenicity analysis for VP4s of EV71 strains isolated from Children in Beijing].

    PubMed

    Li, Yu-Yun; Zhu, Ru-Nan; Qian, Yuan; Deng, Jie; Sun, Yu; Wang, Fang; Zhao, Lin-Qing; Liu, Li-Ying

    2011-05-01

    In order to learn about the correlation between the sequences of VP4 of EV71 and clinical symptoms of patients and analyze the antigenicity of VP4 of EV71, as well as the cross-reactivity with VP4 of CA16, the sequences of VP4 gene from 10 EV71 strains isolated from infants and children with hand, foot and mouth diseases (HFMD) during 2007 to 2009 were determined through standard molecular cloning protocols, and the results were analyzed by EditSeq and MegAlign of DNAStar. Full-length genes of VP4s of EV71 and CA16 were amplified from virus isolates and expressed in E. coli. Then the expressed VP4s were used as antigens to detect IgG antibody in 189 sera samples from people taking health check up and patients of non-HFMD by Western-Blot. They were also used to detect IgM antibody in 14 of sera samples from infants and children with EV71 infection and 12 of sera samples from those with CA16 infection. The nucleotides identities among these 10 sequences of VP4s isolated in our lab were 94.20% - 100.00% and the deduced amino acids were identical. There was no consistent divergence between the sequences of serious cases and those from general HFMD cases. Phylogenetic analysis based on VP4s indicated that these 10 VP4s of EV71 belonged to C4. The nucleotide identities between EV71 VP4 (s67) and CA16 VP4 (s401) was 69.60% and the deduced amino acids identities was 78.60%. In the detection of IgG, the sera-positive rate for EV71 VP4 was 38.10% and the sera-positive rate of CA16 VP4 was 58.20%. The difference in the sera-positive rate between them was significant (chi2 = 15.30, P < 0.01), suggesting that the expressed VP4s of EV71 and CA16 were of good antigenicity and not cross-reactive. There was no positive reaction detected for IgM against VP4s for EV71 or CA16. The data from this study reveal important information for the further study of EV71.

  13. A role for H2S in the microcirculation of newborns: the major metabolite of H2S (thiosulphate) is increased in preterm infants.

    PubMed

    Dyson, Rebecca M; Palliser, Hannah K; Latter, Joanna L; Chwatko, Grazyna; Glowacki, Rafal; Wright, Ian M R

    2014-01-01

    Excessive vasodilatation during the perinatal period is associated with cardiorespiratory instability in preterm neonates. Little evidence of the mechanisms controlling microvascular tone during circulatory transition exists. We hypothesised that hydrogen sulphide (H2S), an important regulator of microvascular reactivity and central cardiac function in adults and animal models, may contribute to the vasodilatation observed in preterm newborns. Term and preterm neonates (24-43 weeks gestational age) were studied. Peripheral microvascular blood flow was assessed by laser Doppler. Thiosulphate, a urinary metabolite of H2S, was determined by high performance liquid chromatography as a measure of 24 hr total body H2S turnover for the first 3 days of postnatal life. H2S turnover was greatest in very preterm infants and decreased with increasing gestational age (p = 0.0001). H2S turnover was stable across the first 72 hrs of life in older neonates. In very preterm neonates, H2S turnover increased significantly from day 1 to 3 (p =0.0001); and males had higher H2S turnover than females (p = 0.04). A significant relationship between microvascular blood flow and H2S turnover was observed on day 2 of postnatal life (p = 0.0004). H2S may play a role in maintaining microvascular tone in the perinatal period. Neonates at the greatest risk of microvascular dysfunction characterised by inappropriate peripheral vasodilatation--very preterm male neonates--are also the neonates with highest levels of total body H2S turnover suggesting that overproduction of this gasotransmitter may contribute to microvascular dysfunction in preterms. Potentially, H2S is a target to selectively control microvascular tone in the circulation of newborns.

  14. On the Role of Additional [4Fe-4S] Clusters with a Free Coordination Site in Radical-SAM Enzymes

    PubMed Central

    Mulliez, Etienne; Duarte, Victor; Arragain, Simon; Fontecave, Marc; Atta, Mohamed

    2017-01-01

    The canonical CysXXXCysXXCys motif is the hallmark of the Radical-SAM superfamily. This motif is responsible for the ligation of a [4Fe-4S] cluster containing a free coordination site available for SAM binding. The five enzymes MoaA, TYW1, MiaB, RimO and LipA contain in addition a second [4Fe-4S] cluster itself bound to three other cysteines and thus also displaying a potentially free coordination site. This review article summarizes recent important achievements obtained on these five enzymes with the main focus to delineate the role of this additional [4Fe-4S] cluster in catalysis. PMID:28361051

  15. The [4Fe4S] cluster of human DNA primase functions as a redox switch using DNA charge transport.

    PubMed

    O'Brien, Elizabeth; Holt, Marilyn E; Thompson, Matthew K; Salay, Lauren E; Ehlinger, Aaron C; Chazin, Walter J; Barton, Jacqueline K

    2017-02-24

    DNA charge transport chemistry offers a means of long-range, rapid redox signaling. We demonstrate that the [4Fe4S] cluster in human DNA primase can make use of this chemistry to coordinate the first steps of DNA synthesis. Using DNA electrochemistry, we found that a change in oxidation state of the [4Fe4S] cluster acts as a switch for DNA binding. Single-atom mutations that inhibit this charge transfer hinder primase initiation without affecting primase structure or polymerization. Generating a single base mismatch in the growing primer duplex, which attenuates DNA charge transport, inhibits primer truncation. Thus, redox signaling by [4Fe4S] clusters using DNA charge transport regulates primase binding to DNA and illustrates chemistry that may efficiently drive substrate handoff between polymerases during DNA replication.

  16. Increased Cortical Inhibition in Autism-Linked Neuroligin-3R451C Mice Is Due in Part to Loss of Endocannabinoid Signaling

    PubMed Central

    Speed, Haley E.; Masiulis, Irene; Gibson, Jay R.; Powell, Craig M.

    2015-01-01

    A single, maternally inherited, X-linked point mutation leading to an arginine to cysteine substitution at amino acid 451 (R451C) of Neuroligin 3 (NLGN3R451C) is a likely cause of autism in two brothers. Knockin mice expressing the Nlgn3R451C mutation in place of wild-type Nlgn3 demonstrate increased inhibitory synaptic strength in somatosensory cortex, resulting in an excitatory/inhibitory (E/I) imbalance that is potentially relevant for autism-associated behavioral deficits characteristic of these mice. We have replicated the increase in evoked inhibitory postsynaptic currents (eIPSCs) onto layer II/III cortical pyramidal neurons. We also find that increased frequency of spontaneous mIPSCs in Nlgn3R451C mice occurs in the absence of action potential-driven transmission. This suggests the E/I imbalance is due to changes at the synapse level, as opposed to the network level. Next, we use paired whole-cell recordings in an attempt to identify specific interneuron subtypes affected by the Nlgn3R451C mutation. Curiously, we observe no change in the amplitude of cell-to-cell, unitary IPSCs (uIPSCs) from parvalbumin-positive (PV) or somatostatin-positive (SOM) interneurons onto pyramidal neurons. We also observe no change in the number or density of PV and SOM interneurons in LII/III of somatosensory cortex. This effectively rules out a role for these particular interneurons in the increased inhibitory synaptic transmission, pointing to perhaps alternative interneuron subtypes. Lastly, impaired endocannabinoid signaling has been implicated in hippocampal synaptic dysfunction in Nlgn3R451C mice, but has not been investigated at cortical synapses. We find that bath application of the CB1 antagonist, AM 251 in WT mice eliminates the Nlgn3R451C increase in eIPSC amplitude and mIPSC frequency, indicating that increased inhibitory transmission in mutant mice is due, at least in part, to a loss of endocannabinoid signaling through CB1 receptors likely acting at interneurons

  17. Effect of H2S concentration on the corrosion behavior of pipeline steel under the coexistence of H2S and CO2

    NASA Astrophysics Data System (ADS)

    Li, Da-peng; Zhang, Lei; Yang, Jian-wei; Lu, Min-xu; Ding, Jin-hui; Liu, Ming-liang

    2014-04-01

    The effect of H2S concentration on H2S/CO2 corrosion of API-X60 steel was studied by scanning electron microscopy, a weight-loss method, potentiodynamic polarization tests, and the electrochemical impedance spectroscopy technique. It is found that the corrosion process of the steel in an environment where H2S and CO2 coexist at different H2S concentrations is related to the morphological structure and stability of the corrosion product film. With the addition of a small amount of H2S, the size of the anode reaction region is decreased due to constant adsorption and separation of more FeS sediment or more FeHS+ ions on the surface of the steel. Meanwhile, the double-layer capacitance is diminished with increasing anion adsorption capacity. Therefore, the corrosion process is inhibited. The general corrosion rate of the steel rapidly decreases after the addition of a small amount of H2S under the coexistence of H2S and CO2. With a further increase in H2S concentration, certain parts of the corrosion product film become loose and even fall off. Thus, the protection provided by the corrosion product film worsens, and the corrosion rate tends to increase.

  18. A practical guide to working with H2S at the interface of chemistry and biology.

    PubMed

    Hartle, Matthew D; Pluth, Michael D

    2016-11-07

    Hydrogen sulfide (H2S) is the most recently accepted endogenously produced gasotransmitter and is now implicated in a variety of physiological functions. In this tutorial review, our goal is to provide researchers new to the field of H2S chemical biology with practical considerations, pitfalls, and best practices to enable smooth entry into investigations focused on biological H2S. We present practical handling and safety considerations for working with this reactive biomolecule, and cover basic roles of H2S biogenesis and action. Experimental methods for modulating H2S levels, including enzymatic knockout, RNA silencing, enzymatic inhibition, and use of small molecule H2S donors are highlighted. Complementing H2S modulation techniques, we also highlight current strategies for H2S detection and quantification.

  19. Suppression of Nonmagnetic Insulating State by Application of Pressure in Mineral Tetrahedrite Cu12Sb4S13

    NASA Astrophysics Data System (ADS)

    Kitagawa, Shunsaku; Sekiya, Taishi; Araki, Shingo; Kobayashi, Tatsuo C.; Ishida, Kenji; Kambe, Takashi; Kimura, Takumi; Nishimoto, Naoki; Kudo, Kazutaka; Nohara, Minoru

    2015-09-01

    The mineral tetrahedrite Cu12Sb4S13 exhibits a first-order metal-insulator transition (MIT) at TMI = 85 K and ambient pressure. We measured the 63Cu-NMR at ambient pressure and the resistivity and magnetic susceptibility at high pressures. 63Cu-NMR results indicate a nonmagnetic insulating ground state in this compound. The MIT is monotonically suppressed by pressure and disappears at ˜1.0 GPa. Two other anomalies are observed in the resistivity measurements, and the pressure-temperature phase diagram of Cu12Sb4S13 is constructed.

  20. Predicted Thermoelectric Properties of the Layered XBi4S7 (X = Mn, Fe) Based Materials: First Principles Calculations

    NASA Astrophysics Data System (ADS)

    Azam, Sikander; Khan, Saleem Ayaz; Goumri-Said, Souraya; Kanoun, Mohammed Benali

    2017-01-01

    We report a theoretical investigation of electronic structures, optical and thermoelectric properties of two ternary-layered chalcogenides, MnBi4S7 and FeBi4S7 , by combining the first principles density functional calculations and semi-local Boltzmann transport theory. The calculated electronic band structure have demonstrated that both compounds exhibit indirect band gaps. The optical transitions are explored via the dielectric function (real and imaginary parts) along with other related optical constants including refractive index, reflectivity, and energy loss spectrum. These chalcogenides have exhibited interesting thermoelectric properties such as Seebeck's coefficient, electrical and thermal conductivity, and power factor as function of temperatures.

  1. Preparation of Li2S-P2S5 solid electrolyte from N-methylformamide solution and application for all-solid-state lithium battery

    NASA Astrophysics Data System (ADS)

    Teragawa, Shingo; Aso, Keigo; Tadanaga, Kiyoharu; Hayashi, Akitoshi; Tatsumisago, Masahiro

    2014-02-01

    Electrode-solid electrolyte composite materials for all-solid-state lithium batteries were prepared by coating of the Li2S-P2S5 solid electrolyte onto LiCoO2 particles using a N-methylformamide (NMF) solution of 80Li2S·20P2S5 (mol%) solid electrolyte. SEM and EDX analysis showed that the Li2S-P2S5 solid electrolyte was uniformly coated on LiCoO2 particles. The all-solid-state cell using the LiCoO2 particles coated with the solid electrolyte showed higher charge-discharge capacity than the cells using uncoated LiCoO2 particles.

  2. Novel opioid peptide derived antagonists containing (2S)-2-methyl-3-(2,6-dimethyl-4-carbamoylphenyl)propanoic acid [(2S)-Mdcp].

    PubMed

    Ghosh, Animesh; Luo, Jie; Liu, Chen; Weltrowska, Grazyna; Lemieux, Carole; Chung, Nga N; Lu, Yixin; Schiller, Peter W

    2008-09-25

    A synthesis of the novel tyrosine analogue (2 S)-2-methyl-3-(2,6-dimethyl-4-carbamoylphenyl)propanoic acid [(2 S)-Mdcp] (15) was developed. In (2 S)-Mdcp, the amino and hydroxyl groups of 2',6'-dimethyltyrosine are replaced by a methyl and a carbamoyl group, respectively, and its substitution for Tyr (1) in opioid agonist peptides resulted in compounds showing antagonism at all three opioid receptors. The cyclic peptide (2 S)-Mdcp-c[D-Cys-Gly-Phe(pNO 2)-D-Cys]NH 2 (1) was a potent and selective mu antagonist, whereas (2 S)-Mdcp-c[D-Pen-Gly-Phe(pF)-Pen]-Phe-OH (3) showed subnanomolar delta antagonist activity and extraordinary delta selectivity.

  3. Diffusion of gold from the inner core to the surface of Ag(2)S nanocrystals.

    PubMed

    Yang, Jun; Ying, Jackie Y

    2010-02-24

    The diffusion of Au in Ag(2)S from the inner core to the surface of Ag(2)S was reported, and a new nanocomposite of core-shell Pt@Ag(2)S and Au nanoparticles has been derived through this diffusion phenomenon. Ostwald ripening was observed by transmission electron microscopy during the characterization of the nanocomposite. This elucidated the mechanism of formation of semiconductor-metal heterostructures as a consequence of Au diffusion in Ag(2)S nanocrystals.

  4. Factors affecting temporal H2S emission at construction and demolition (C&D) debris landfills.

    PubMed

    Xu, Qiyong; Townsend, Timothy

    2014-02-01

    Odor problems associated with H2S emissions often result in odor complaints from nearby residents of C&D debris landfills, especially in the early morning. As part of a field study conducted on H2S removal ability using different cover materials, daily and seasonal H2S emissions through a soil cover layer were monitored at a C&D debris landfill to investigate factors affecting H2S emissions. H2S emission rates were not a constant, but varied seasonally, with an average emission rate of 4.67×10(-6)mgm(-2)s(-1). During a the 10-month field study, as the H2S concentration increased from 140ppm to about 3500ppm underneath the cover soil in the testing cell, H2S emissions ranged from zero to a maximum emission rate of 1.24×10(-5)mgm(-2)s(-1). Continuous emission monitoring indicated that H2S emissions even changed over time throughout the day, generally increasing from morning to afternoon, and were affected by soil moisture and temperature. Laboratory experiments were also conducted to investigate the effects of H2S concentration and cover soil moisture content on H2S emissions. The results showed that increased soil moisture reduced H2S emissions by retarding H2S migration through cover soil and dissolving H2S into soil water. The field study also indicated that due to atmospheric dispersion, high H2S emissions may not cause odor problems.

  5. Characterization of mutations of the phosphoinositide-3-kinase regulatory subunit, PIK3R2, in perisylvian polymicrogyria: a next generation sequencing study

    PubMed Central

    Mirzaa, Ghayda; Conti, Valerio; Timms, Andrew E.; Smyser, Christopher D.; Ahmed, Sarah; Carter, Melissa; Barnett, Sarah; Hufnagel, Robert B.; Goldstein, Amy; Narumi-Kishimoto, Yoko; Olds, Carissa; Collins, Sarah; Johnston, Kathreen; Deleuze, Jean-François; Nitschké, Patrick; Friend, Kathryn; Harris, Catharine; Goetsch, Allison; Martin, Beth; Boyle, Evan August; Parrini, Elena; Mei, Davide; Tattini, Lorenzo; Slavotinek, Anne; Blair, Ed; Barnett, Christopher; Shendure, Jay; Chelly, Jamel; Dobyns, William B.; Guerrini, Renzo

    2015-01-01

    SUMMARY Background Bilateral perisylvian polymicrogyria (BPP), the most common form of regional polymicrogyria, causes the congenital bilateral perisylvian syndrome, featuring oromotor dysfunction, cognitive impairment and epilepsy. BPP is etiologically heterogeneous, but only a few genetic causes have been reported. The aim of this study was to identify additional genetic etiologies of BPP and delineate their frequency in this patient population. Methods We performed child-parent (trio)-based whole exome sequencing (WES) on eight children with BPP. Following the identification of mosaic PIK3R2 mutations in two of these eight children, we performed targeted screening of PIK3R2 in a cohort of 118 children with BPP who were ascertained from 1980 until 2015 using two methods. First, we performed targeted sequencing of the entire PIK3R2 gene by single molecule molecular inversion probes (smMIPs) on 38 patients with BPP with normal-large head size. Second, we performed amplicon sequencing of the recurrent PIK3R2 mutation (p.Gly373Arg) on 80 children with various types of polymicrogyria including BPP. One additional patient underwent clinical WES independently, and was included in this study given the phenotypic similarity to our cohort. All patients included in this study were children (< 18 years of age) with polymicrogyria enrolled in our research program. Findings Using WES, we identified a mosaic mutation (p.Gly373Arg) in the regulatory subunit of the PI3K-AKT-MTOR pathway, PIK3R2, in two children with BPP. Of the 38 patients with BPP and normal-large head size who underwent targeted next generation sequencing by smMIPs, we identified constitutional and mosaic PIK3R2 mutations in 17 additional children. In parallel, one patient was found to have the recurrent PIK3R2 mutation by clinical WES. Seven patients had BPP alone, and 13 had BPP in association with features of the megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome (MPPH). Nineteen patients had

  6. (2S,4E)-2-Hydroxy-4-octen-3-one, a Male-Produced Attractant Pheromone of the Cerambycid Beetle Tylonotus bimaculatus.

    PubMed

    Zou, Yunfan; Millar, Jocelyn G; Blackwood, J Scott; Van Duzor, Ryan; Hanks, Lawrence M; Mongold-Diers, Judith A; Wong, Joseph C H; Ray, Ann M

    2015-07-01

    We report the identification of a novel pheromone structure from males of the cerambycid beetle Tylonotus bimaculatus Haldeman (Cerambycinae: Hesperophanini), a species native to eastern North America. Volatiles collected from adult males contained (2S,4E)-2-hydroxyoct-4-en-3-one (71%), (3R,4E)-3-hydroxyoct-4-en-2-one (15%), (E)-4-octen-2,3-dione (13%), and 2,3-octanedione (1.5%). Four independent field bioassays with synthetic compounds confirmed that adults of both sexes were attracted by the racemate of the major component, (E)-2-hydroxyoct-4-en-3-one. No other cerambycid species were attracted in significant numbers. Attraction of both sexes is consistent with the male-produced pheromones of many other species in the subfamily Cerambycinae, but T. bimaculatus is unusual in having a pheromone chemistry that is so far unique among species in that subfamily.

  7. Singlet-Triplet Excitations and Long-Range Entanglement in the Spin-Orbital Liquid Candidate FeSc2S4.

    PubMed

    Laurita, N J; Deisenhofer, J; Pan, LiDong; Morris, C M; Schmidt, M; Johnsson, M; Tsurkan, V; Loidl, A; Armitage, N P

    2015-05-22

    Theoretical models of the spin-orbital liquid (SOL) FeSc2S4 have predicted it to be in close proximity to a quantum critical point separating a spin-orbital liquid phase from a long-range ordered magnetic phase. Here, we examine the magnetic excitations of FeSc2S4 through time-domain terahertz spectroscopy under an applied magnetic field. At low temperatures an excitation emerges that we attribute to a singlet-triplet excitation from the SOL ground state. A threefold splitting of this excitation is observed as a function of applied magnetic field. As singlet-triplet excitations are typically not allowed in pure spin systems, our results demonstrate the entangled spin and orbital character of singlet ground and triplet excited states. Using experimentally obtained parameters we compare to existing theoretical models to determine FeSc2S4's proximity to the quantum critical point. In the context of these models, we estimate the characteristic length of the singlet correlations to be ξ/(a/2)≈8.2 (where a/2 is the nearest neighbor lattice constant), which establishes FeSc2S4 as a SOL with long-range entanglement.

  8. ESCRT machinery potentiates HIV-1 utilization of the PI(4,5)P(2)-PLC-IP3R-Ca(2+) signaling cascade.

    PubMed

    Ehrlich, Lorna S; Medina, Gisselle N; Carter, Carol A

    2011-10-21

    Human immunodeficiency virus type 1 (HIV-1) release efficiency is directed by late (L) domain motifs in the viral structural precursor polyprotein Gag, which serve as links to the ESCRT (endosomal sorting complex required for transport) machinery. Linkage is normally through binding of Tsg101, an ESCRT-1 component, to the P(7)TAP motif in the p6 region of Gag. In its absence, budding is directed by binding of Alix, an ESCRT adaptor protein, to the LY(36)PX(n)L motif in Gag. We recently showed that budding requires activation of the inositol 1,4,5-triphosphate receptor (IP3R), a protein that "gates" Ca(2+) release from intracellular stores, triggers Ca(2+) cell influx and thereby functions as a major regulator of Ca(2+) signaling. In the present study, we determined whether the L domain links Gag to Ca(2+) signaling machinery. Depletion of IP3R and inactivation of phospholipase C (PLC) inhibited budding whether or not Tsg101 was bound to Gag. PLC hydrolysis of phosphatidylinositol-(4,5)-bisphosphate generates inositol (1,4,5)-triphosphate, the ligand that activates IP3R. However, with Tsg101 bound, Gag release was independent of Gq-mediated activation of PLC, and budding was readily enhanced by pharmacological stimulation of PLC. Moreover, IP3R was redistributed to the cell periphery and cytosolic Ca(2+) was elevated, events indicative of induction of Ca(2+) signaling. The results suggest that L domain function, ESCRT machinery and Ca(2+) signaling are linked events in Gag release.

  9. Gain-of-function mutation in PIK3R1 in a patient with a narrow clinical phenotype of respiratory infections.

    PubMed

    Martínez-Saavedra, María Teresa; García-Gomez, Sonia; Domínguez Acosta, Ana; Mendoza Quintana, Juan Jesús; Páez, Jesús Poch; García-Reino, Eduardo J; Camps, Gracián; Martinez-Barricarte, Rubén; Itan, Yuval; Boisson, Bertrand; Sánchez-Ramón, Silvia; Regueiro, José Ramón; Casanova, Jean-Laurent; Rodríguez-Gallego, Carlos; Pérez de Diego, Rebeca

    2016-12-01

    Antibody deficiencies can be caused by a variety of defects that interfere with B-cell development, maturation, and/or function. Using whole-exome sequencing we found a PIK3R1 mutation in a patient with hypogammaglobulinemia and a narrow clinical phenotype of respiratory infections. Early diagnosis is crucial; careful analysis of B and T-cells followed by genetic analyses may help to distinguish activated PI3K-delta syndrome (APDS) from other, less severe, predominantly antibody deficiencies.

  10. Review: Cav2.3 R-type Voltage-Gated Ca2+ Channels - Functional Implications in Convulsive and Non-convulsive Seizure Activity

    PubMed Central

    Wormuth, Carola; Lundt, Andreas; Henseler, Christina; Müller, Ralf; Broich, Karl; Papazoglou, Anna; Weiergräber, Marco

    2016-01-01

    Background: Researchers have gained substantial insight into mechanisms of synaptic transmission, hyperexcitability, excitotoxicity and neurodegeneration within the last decades. Voltage-gated Ca2+ channels are of central relevance in these processes. In particular, they are key elements in the etiopathogenesis of numerous seizure types and epilepsies. Earlier studies predominantly targeted on Cav2.1 P/Q-type and Cav3.2 T-type Ca2+ channels relevant for absence epileptogenesis. Recent findings bring other channels entities more into focus such as the Cav2.3 R-type Ca2+ channel which exhibits an intriguing role in ictogenesis and seizure propagation. Cav2.3 R-type voltage gated Ca2+ channels (VGCC) emerged to be important factors in the pathogenesis of absence epilepsy, human juvenile myoclonic epilepsy (JME), and cellular epileptiform activity, e.g. in CA1 neurons. They also serve as potential target for various antiepileptic drugs, such as lamotrigine and topiramate. Objective: This review provides a summary of structure, function and pharmacology of VGCCs and their fundamental role in cellular Ca2+ homeostasis. We elaborate the unique modulatory properties of Cav2.3 R-type Ca2+ channels and point to recent findings in the proictogenic and proneuroapoptotic role of Cav2.3 R-type VGCCs in generalized convulsive tonic–clonic and complex-partial hippocampal seizures and its role in non-convulsive absence like seizure activity. Conclusion: Development of novel Cav2.3 specific modulators can be effective in the pharmacological treatment of epilepsies and other neurological disorders. PMID:27843503

  11. Novel 1D coordination polymer {l_brace}Tm(Piv){sub 3{r_brace}n}: Synthesis, structure, magnetic properties and thermal behavior

    SciTech Connect

    Fomina, Irina; Dobrokhotova, Zhanna; Aleksandrov, Grygory; Emelina, Anna; Bykov, Mikhail; Bogomyakov, Artem; Puntus, Lada; Novotortsev, Vladimir; Eremenko, Igor

    2012-01-15

    The new 1D coordination polymer {l_brace}Tm(Piv){sub 3{r_brace}n} (1), where Piv=OOCBu{sup t-}, was synthesized in high yield (>95%) by the reaction of thulium acetate with pivalic acid in air at 100 Degree-Sign S. According to the X-ray diffraction data, the metal atoms in compound 1 are in an octahedral ligand environment unusual for lanthanides. The magnetic and luminescence properties of polymer 1, it's the solid-phase thermal decomposition in air and under argon, and the thermal behavior in the temperature range of -50 Horizontal-Ellipsis +50 Degree-Sign S were investigated. The vaporization process of complex 1 was studied by the Knudsen effusion method combined with mass-spectrometric analysis of the gas-phase composition in the temperature range of 570-680 K. - Graphical Abstract: Novel 1D coordination polymer {l_brace}Tm(Piv){sub 3{r_brace}n} was synthesized and studied by X-ray diffraction. The magnetic, luminescence properties, the thermal behavior and the volatility for the compound {l_brace}Tm(Piv){sub 3{r_brace}n} were investigated. Black-Small-Square Highlights: Black-Right-Pointing-Pointer We synthesized the coordination polymer {l_brace}Tm(Piv){sub 3{r_brace}n}. Black-Right-Pointing-Pointer Tm atoms in polymer have the coordination number 6. Black-Right-Pointing-Pointer Polymer exhibits blue-color emission at room temperature. Black-Right-Pointing-Pointer Polymer shows high thermal stability and volatility. Black-Right-Pointing-Pointer Polymer has no phase transitions in the range of -50 Horizontal-Ellipsis +50 Degree-Sign S.

  12. Basal adenosine modulates the functional properties of AMPA receptors in mouse hippocampal neurons through the activation of A1R A2AR and A3R

    PubMed Central

    Di Angelantonio, Silvia; Bertollini, Cristina; Piccinin, Sonia; Rosito, Maria; Trettel, Flavia; Pagani, Francesca; Limatola, Cristina; Ragozzino, Davide

    2015-01-01

    Adenosine is a widespread neuromodulator within the CNS and its extracellular level is increased during hypoxia or intense synaptic activity, modulating pre- and postsynaptic sites. We studied the neuromodulatory action of adenosine on glutamatergic currents in the hippocampus, showing that activation of multiple adenosine receptors (ARs) by basal adenosine impacts postsynaptic site. Specifically, the stimulation of both A1R and A3R reduces AMPA currents, while A2AR has an opposite potentiating effect. The effect of ARs stimulation on glutamatergic currents in hippocampal cultures was investigated using pharmacological and genetic approaches. A3R inhibition by MRS1523 increased GluR1-Ser845 phosphorylation and potentiated AMPA current amplitude, increasing the apparent affinity for the agonist. A similar effect was observed blocking A1R with DPCPX or by genetic deletion of either A3R or A1R. Conversely, impairment of A2AR reduced AMPA currents, and decreased agonist sensitivity. Consistently, in hippocampal slices, ARs activation by AR agonist NECA modulated glutamatergic current amplitude evoked by AMPA application or afferent fiber stimulation. Opposite effects of AR subtypes stimulation are likely associated to changes in GluR1 phosphorylation and represent a novel mechanism of physiological modulation of glutamatergic transmission by adenosine, likely acting in normal conditions in the brain, depending on the level of extracellular adenosine and the distribution of AR subtypes. PMID:26528137

  13. Transition between the 1 x 1 and ({radical}3 x 2{radical}3)R30{degree} surface structures of GaN in the vapor-phase environment

    SciTech Connect

    Munkholm, A.; Thompson, C.; Stephenson, G. B.; Eastman, J. A.; Auciello, O.; Fini, P.; Speck, J. S.; DenBaars, S. P.

    2000-01-12

    Out-of-plane structures of the GaN(0001) surface in the metal-organic chemical vapor deposition (MOCVD) environment have been determined using in situ grazing-incidence X-ray scattering. The authors measured 11{bar 2}{ell} crystal truncation rod intensities at a variety of temperatures and ammonia partial pressures on both sides of the 1 x 1 to ({radical}3 x 2{radical}3)R30{degree} surface phase transition. The out-of-plane structure of the ({radical}3 x 2{radical}3)R30{degree} phase appears to be nearly independent of temperature below the transition, while the structure of the 1 x 1 phase changes increase rapidly as the phase transition is approached from above. A model for the structure of the 1 x 1 phase with a partially-occupied top Ga layer agrees well with the data. The observed temperature dependence is consistent with a simple model of the equilibrium between the vapor phase and the surface coverage of Ga and N. In addition, the authors present results on the kinetics of reconstruction domain coarsening following a quench into the ({radical}3 x 2{radical}3)R30{degree} phase field.

  14. Ca2+ signaling in astrocytes from IP3R2−/− mice in brain slices and during startle responses in vivo

    PubMed Central

    Srinivasan, Rahul; Huang, Ben S.; Venugopal, Sharmila; Johnston, April D.; Chai, Hua; Zeng, Hongkui; Golshani, Peyman; Khakh, Baljit S.

    2015-01-01

    Intracellular Ca2+ signaling is considered important for multiple astrocyte functions in neural circuits. However, mice devoid of inositol triphosphate type 2 receptors (IP3R2) reportedly lack all astrocyte Ca2+ signaling, but display no neuronal or neurovascular deficits, implying that astrocyte Ca2+ fluctuations play no role(s) in these functions. An assumption has been that loss of somatic Ca2+ fluctuations also reflects similar loss within astrocyte processes. Here, we tested this assumption and found diverse types of Ca2+ fluctuations within astrocytes, with most occurring within processes rather than in somata. These fluctuations were preserved in IP3R2−/− mice in brain slices and in vivo, occurred in endfeet, were increased by G-protein coupled receptor activation and by startle-induced neuromodulatory responses. Our data reveal novel Ca2+ fluctuations within astrocytes and highlight limitations of studies that used IP3R2−/− mice to evaluate astrocyte contributions to neural circuit function and mouse behavior. PMID:25894291

  15. Efficient Z-scheme photocatalyst from simultaneous decoration of In2S3 nanosheets and WO3 nanorods on graphene sheets

    NASA Astrophysics Data System (ADS)

    Zhang, Qingran; Luo, Mingbo; Sun, Ya-Ping; Liu, Yuanfang; Cao, Aoneng

    2016-07-01

    Inspired by natural photosynthesis, the Z-scheme photocatalyst is a promising approach to extend the absorption spectra of photocatalysts and reduce the recombination of photo-generated electrons and holes. However, the fabrication of well-structured efficient multi-component Z-scheme photocatalysts is still a big challenge. We report here a facile one-pot method to synthesize graphene-based Z-scheme photocatalysts. The one-pot method guarantees good distribution of well-structured individual components on thin-layered rGO sheets with excellent connections. With inactive WO3 nanorods and inactive β-In2S3 nanosheets attached to the surface of the rGO sheets, the synthesized In2S3/WO3/rGO tertiary nanocomposite shows excellent visible-light catalytic activity for hydrogen production at 1524 μmol g-1 h-1, demonstrating unambiguously the Z-scheme catalytic mechanism. To prevent cross-reactions and interferences, our strategy was to choose no more than one ionic precipitation reaction for the one-pot process, as unwanted cross-reactions could become inevitable if many cations and anions were present. This fabrication strategy should be applicable generally to synthesize other multiple-component nanocomposites, as demonstrated also by the preliminary results of the successful synthesis of the BiVO4/WO3/rGO nanocomposite (one ionic precipitation reaction and one hydrolysis reaction) and WO3/TiO2/rGO nanocomposite (two hydrolysis reactions).

  16. Efficient Z-scheme photocatalyst from simultaneous decoration of In2S3 nanosheets and WO3 nanorods on graphene sheets.

    PubMed

    Zhang, Qingran; Luo, Mingbo; Sun, Ya-Ping; Liu, Yuanfang; Cao, Aoneng

    2016-07-15

    Inspired by natural photosynthesis, the Z-scheme photocatalyst is a promising approach to extend the absorption spectra of photocatalysts and reduce the recombination of photo-generated electrons and holes. However, the fabrication of well-structured efficient multi-component Z-scheme photocatalysts is still a big challenge. We report here a facile one-pot method to synthesize graphene-based Z-scheme photocatalysts. The one-pot method guarantees good distribution of well-structured individual components on thin-layered rGO sheets with excellent connections. With inactive WO3 nanorods and inactive β-In2S3 nanosheets attached to the surface of the rGO sheets, the synthesized In2S3/WO3/rGO tertiary nanocomposite shows excellent visible-light catalytic activity for hydrogen production at 1524 μmol g(-1) h(-1), demonstrating unambiguously the Z-scheme catalytic mechanism. To prevent cross-reactions and interferences, our strategy was to choose no more than one ionic precipitation reaction for the one-pot process, as unwanted cross-reactions could become inevitable if many cations and anions were present. This fabrication strategy should be applicable generally to synthesize other multiple-component nanocomposites, as demonstrated also by the preliminary results of the successful synthesis of the BiVO4/WO3/rGO nanocomposite (one ionic precipitation reaction and one hydrolysis reaction) and WO3/TiO2/rGO nanocomposite (two hydrolysis reactions).

  17. 40 CFR 122.30 - What are the objectives of the storm water regulations for small MS4s?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 22 2014-07-01 2013-07-01 true What are the objectives of the storm... objectives of the storm water regulations for small MS4s? (a) Sections 122.30 through 122.37 are written in a... 402(p)(6) of the Clean Water Act, the purpose of this portion of the storm water program is...

  18. 40 CFR 122.30 - What are the objectives of the storm water regulations for small MS4s?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 23 2013-07-01 2013-07-01 false What are the objectives of the storm... objectives of the storm water regulations for small MS4s? (a) Sections 122.30 through 122.37 are written in a... 402(p)(6) of the Clean Water Act, the purpose of this portion of the storm water program is...

  19. 40 CFR 122.30 - What are the objectives of the storm water regulations for small MS4s?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 23 2012-07-01 2012-07-01 false What are the objectives of the storm... objectives of the storm water regulations for small MS4s? (a) Sections 122.30 through 122.37 are written in a... 402(p)(6) of the Clean Water Act, the purpose of this portion of the storm water program is...

  20. 40 CFR 122.30 - What are the objectives of the storm water regulations for small MS4s?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false What are the objectives of the storm... objectives of the storm water regulations for small MS4s? (a) Sections 122.30 through 122.37 are written in a... 402(p)(6) of the Clean Water Act, the purpose of this portion of the storm water program is...

  1. 40 CFR 123.35 - As the NPDES Permitting Authority for regulated small MS4s, what is my role?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... MS4 storm water program.) (b) You must develop a process, as well as criteria, to designate small MS4s... under the NPDES storm water discharge control program. This process must include the authority to... storm water discharge results in or has the potential to result in exceedances of water...

  2. 40 CFR 122.30 - What are the objectives of the storm water regulations for small MS4s?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 22 2011-07-01 2011-07-01 false What are the objectives of the storm... objectives of the storm water regulations for small MS4s? (a) Sections 122.30 through 122.37 are written in a... 402(p)(6) of the Clean Water Act, the purpose of this portion of the storm water program is...

  3. Electrochemistry of the [4Fe4S] Cluster in Base Excision Repair Proteins: Tuning the Redox Potential with DNA.

    PubMed

    Bartels, Phillip L; Zhou, Andy; Arnold, Anna R; Nuñez, Nicole N; Crespilho, Frank N; David, Sheila S; Barton, Jacqueline K

    2017-03-02

    Escherichia coli endonuclease III (EndoIII) and MutY are DNA glycosylases that contain [4Fe4S] clusters and that serve to maintain the integrity of the genome after oxidative stress. Electrochemical studies on highly oriented pyrolytic graphite (HOPG) revealed that DNA binding by EndoIII leads to a large negative shift in the midpoint potential of the cluster, consistent with stabilization of the oxidized [4Fe4S](3+) form. However, the smooth, hydrophobic HOPG surface is nonideal for working with proteins in the absence of DNA. In this work, we use thin film voltammetry on a pyrolytic graphite edge electrode to overcome these limitations. Improved adsorption leads to substantial signals for both EndoIII and MutY in the absence of DNA, and a large negative potential shift is retained with DNA present. In contrast, the EndoIII mutants E200K, Y205H, and K208E, which provide electrostatic perturbations in the vicinity of the cluster, all show DNA-free potentials within error of wild type; similarly, the presence of negatively charged poly-l-glutamate does not lead to a significant potential shift. Overall, binding to the DNA polyanion is the dominant effect in tuning the redox potential of the [4Fe4S] cluster, helping to explain why all DNA-binding proteins with [4Fe4S] clusters studied to date have similar DNA-bound potentials.

  4. Effect of double blocking layers at TiO2/Sb2S3 and Sb2S3/spiro-MeOTAD interfaces on photovoltaic performance.

    PubMed

    Kang, Hyun-Woo; Lee, Jin-Wook; Park, Nam-Gyu

    2014-01-01

    The effect of double blocking layers on the Sb(2)S(3)-sensitized all solid state solar cell are investigated. Thin layers of ZrO(2) (blocking layer 1, BL1) and ZnS (blocking layer 2, BL2) are introduced at the TiO(2)/Sb(2)S(3) and Sb(2)S(3)/hole transporting material (HTM) interfaces. The presence of BL1 is found to improve the open-circuit voltage (V(oc)) from 457 mV to 618 mV, whereas BL2 improves mainly short-circuit current density (J(sc)) from 11.1 mA cm(-2) to 14.0 mA cm(-2). Transient photovoltage confirms that the BL1 efficiently blocks charge recombination, responsible for the V(oc) enhancement, whereas the BL2 has little effect on suppression of charge recombination. Surface modification of Sb(2)S(3) by BL2, on the other hand, leads to recovery of Sb(2)S(3) from the surface oxidized Sb(2)O(5), which affects the J(sc) increment. The present results suggest that the TiO(2)/Sb(2)S(3) interface is the main pathway for charge recombination rather than the Sb(2)S(3)/HTM interface. Double blocking layers enhanced the power conversion efficiency by 30%.

  5. Azotobacter vinelandii ferredoxin I. Aspartate 15 facilitates proton transfer to the reduced [3Fe-4S] cluster.

    PubMed

    Shen, B; Martin, L L; Butt, J N; Armstrong, F A; Stout, C D; Jensen, G M; Stephens, P J; La Mar, G N; Gorst, C M; Burgess, B K

    1993-12-05

    The [3Fe-4S]+/0 cluster of Azotobacter vinelandii ferredoxin I (AvFdI) has an unusually low and strongly pH-dependent reduction potential (E'0). The reduced cluster exists in two forms, depending upon pH, that exhibit substantially different magnetic circular dichroism (MCD) spectra. Recent studies have established that the MCD changes observed on decreasing the pH from 8.3 (alkaline form) to 6.0 (acid form) cannot be explained either by a change in spin state of the cluster (Stephens, P.J., Jensen, G.M., Devlin, F.J., Morgan, T.V., Stout, C. D., Martin, A.E., and Burgess, B.K. (1991) Biochemistry 30, 3200-3209) or by a major structural change (e.g. ligand exchange) (Stout, C.D. (1993) J. Biol. Chem. 268, 25920-25927). Here, we have examined the influence of aspartate 15 on the pH dependence of the spectroscopic and electrochemical properties of AvFdI by construction of a D15N mutant. Aspartate 15, which is salt-bridged to lysine 84 at the protein surface, is the closest ionizable residue to the [3Fe-4S] cluster. The results show that replacement of aspartate by asparagine results in an approximately 20-mV increase in E'0 for the [3Fe-4S]+/0 cluster at high pH concomitant with an approximately 0.8-pH unit decrease in the pK of the reduced form. The major pH dependence of E'0 is preserved as is the effect observed by MCD. These data eliminate the possibility that the MCD change is due to the presence of Asp-15 and support the conclusion that it originates in direct protonation of the [3Fe-4S]0 cluster, probably on a sulfide ion. Voltammetric studies show that interconversion between [3Fe-4S]+ and [3Fe-4S]0 at acidic pH involves rapid electron transfer followed by proton transfer (for reduction) and then proton transfer followed by electron transfer (for oxidation). Ionized aspartate 15 facilitates proton transfer. Thus, protonation and deprotonation are much slower for D15N relative to the native protein at pH > 5.5. Proton transfer reactions necessary for further

  6. Preparation of In2S3 nanopraricle by ultrasonic dispersion and its tribology property.

    PubMed

    Li, Zhiwei; Tao, Xiaojun; Wu, Zhishen; Zhang, Pingyu; Zhang, Zhijun

    2009-02-01

    In this paper, we describe a facile and rapid method for preparing In2S3 nanoparticles via ultrasound dispersion. This method allows us to prepare In2S3 nanoparticles from bulk indium and sulfur with ease and without using expensive agents and in a short time. The possible growing mechanism of the In2S3 nanoparticles was presented. In addition, we provide detailed characterizations including TEM, XRD, TG-DTA, and XPS to study the shape, composition and structure of In2S3 nanoparticles. We also studied the tribology property of In2S3 nanoparticles made using this novel recipe.

  7. Bis[1,2-bis­(eth­oxy­carbon­yl)ethene-1,2-dithiol­ato-κ2 S,S′]bis­(η5-penta­methyl­cyclo­penta­dien­yl)tetra-μ3-sulfido-diiron(IV)diiron(III)(3 Fe—Fe)

    PubMed Central

    Ito, Shohei; Hisamichi, Nozomu; Takase, Tsugiko; Inomata, Shinji

    2013-01-01

    The title compound, [Fe4(C10H15)2(C8H10O4S2)2S4], contains a twisted Fe4S4 cubane-like core. A twofold rotation axis passes through the Fe4S4 core, completing the coordination of the four Fe atoms with two penta­methyl­cyclo­penta­dienyl ligands and two chelating dithiol­ate ligands. There are three short Fe—Fe and three long Fe⋯Fe contacts in the Fe4S4 core, suggesting bonding and non-bonding inter­actions, respectively. The Fe—S bonds in the Fe4S4 core range from 2.1523 (5) to 2.2667 (6) Å and are somewhat longer than the Fe—S bonds involving the dithiol­ate ligand. PMID:23633986

  8. Bis[1,2-bis-(eth-oxy-carbon-yl)ethene-1,2-dithiol-ato-κ(2) S,S']bis-(η(5)-penta-methyl-cyclo-penta-dien-yl)tetra-μ3-sulfido-diiron(IV)diiron(III)(3 Fe-Fe).

    PubMed

    Ito, Shohei; Hisamichi, Nozomu; Takase, Tsugiko; Inomata, Shinji

    2013-04-01

    The title compound, [Fe4(C10H15)2(C8H10O4S2)2S4], contains a twisted Fe4S4 cubane-like core. A twofold rotation axis passes through the Fe4S4 core, completing the coordination of the four Fe atoms with two penta-methyl-cyclo-penta-dienyl ligands and two chelating dithiol-ate ligands. There are three short Fe-Fe and three long Fe⋯Fe contacts in the Fe4S4 core, suggesting bonding and non-bonding inter-actions, respectively. The Fe-S bonds in the Fe4S4 core range from 2.1523 (5) to 2.2667 (6) Å and are somewhat longer than the Fe-S bonds involving the dithiol-ate ligand.

  9. The ternary yttrium sulfides, CaY{sub 2}S{sub 4}, and BaY{sub 2}S{sub 4}: Structures and properties

    SciTech Connect

    Lowe-Ma, C.K.; Vanderah, T.A.; Smith, T.E.

    1995-07-01

    X-ray single-crystal structure determinations have confirmed that CaY{sub 2}S{sub 4} crystallizes in the orthorhombic [Yb{sub 3}S{sub 4}]-type structure whereas SrY{sub 2}S{sub 4} and BaY{sub 2}S{sub 4} adopt the orthorhombic [CaFe{sub 2}O{sub 4}] structure. Both structure types feature three-dimensional frameworks build of edge- and corner-sharing [YS{sub 6}] octahedra. CaY{sub 2}S{sub 4}, in space group Pnma, has cell dimensions a = 12.953(3) {angstrom}, b = 3.8835(5) {angstrom}, c = 13.081(3) {angstrom}, Vol = 658.0(2) {angstrom}{sup 3}, Z = 4, and D{sub x} = 3.494 g/cm{sup 3} (M{sub f} = 346.1). SrY{sub 2}S{sub 4}, in Pmnb, has a = 3.9775(6), b = 11.974(2), c = 14.294(2) {angstrom}, Vol = 680.8(2) {angstrom}{sup 3}, Z = 4, and D{sub x} = 3.841 g/cm{sup 3} for M{sub F} = 393.7; BaY{sub 2}S{sub 4}, in Pmnb, has a = 4.0263(2), b = 12.2134(8), c = 14.484(1) {angstrom}, Vol = 712.23(9) {angstrom}{sup 3}, Z = 4, and D{sub x} = 4.135 g/cm{sup 3} for M{sub f} = 443.4. Room temperature X-ray powder diffraction data for all three compounds and high-temperature unit cells for CaY{sub 2}S{sub 4} are also reported. The overall average linear thermal expansion of CaY{sub 2}S{sub 4}f are also reported. The overall average linear thermal expansion of CaY{sub 2}S{sub 4} upon heating was found to be approximately 11.9 x 10{sup {minus}6}/{degrees}K as compared to that of 7.2 x 10{sup {minus}6}{degrees}K found for ZnS. The onset oxidative decomposition temperatures for CaY{sub 2}S{sub 4}, SrY{sub 2}S{sub 4}, and BaY{sub 2}S{sub 4} were observed to be 545, 565, and 590{degrees}C, respectively, as compared to 530{degrees}C for ZnS. The properties of these compounds indicate that they are potentially useful as infrared window materials.

  10. The Transmembrane Domain of CEACAM1-4S Is a Determinant of Anchorage Independent Growth and Tumorigenicity

    PubMed Central

    Lawson, Erica L.; Mills, David R.; Brilliant, Kate E.; Hixson, Douglas C.

    2012-01-01

    CEACAM1 is a multifunctional Ig-like cell adhesion molecule expressed by epithelial cells in many organs. CEACAM1-4L and CEACAM1-4S, two isoforms produced by differential splicing, are predominant in rat liver. Previous work has shown that downregulation of both isoforms occurs in rat hepatocellular carcinomas. Here, we have isolated an anchorage dependent clone, designated 253T-NT that does not express detectable levels of CEACAM1. Stable transfection of 253-NT cells with a wild type CEACAM1-4S expression vector induced an anchorage independent growth in vitro and a tumorigenic phenotype in vivo. These phenotypes were used as quantifiable end points to examine the functionality of the CEACAM1-4S transmembrane domain. Examination of the CEACAM1 transmembrane domain showed N-terminal GXXXG dimerization sequences and C-terminal tyrosine residues shown in related studies to stabilize transmembrane domain helix-helix interactions. To examine the effects of transmembrane domain mutations, 253-NT cells were transfected with transmembrane domain mutants carrying glycine to leucine or tyrosine to valine substitutions. Results showed that mutation of transmembrane tyrosine residues greatly enhanced growth in vitro and in vivo. Mutation of transmembrane dimerization motifs, in contrast, significantly reduced anchorage independent growth and tumorigenicity. 253-NT cells expressing CEACAM1-4S with both glycine to leucine and tyrosine to valine mutations displayed the growth-enhanced phenotype of tyrosine mutants. The dramatic effect of transmembrane domain mutations constitutes strong evidence that the transmembrane domain is an important determinant of CEACAM1-4S functionality and most likely by other proteins with transmembrane domains containing dimerization sequences and/or C-terminal tyrosine residues. PMID:22235309

  11. Induction of K562 Cell Apoptosis by As4S4 via Down-Regulating miR181

    PubMed Central

    Gong, Jiangjiang; Zheng, Shunli; Zhang, Lei; Wang, Yi; Meng, Jiali

    2017-01-01

    Background Chronic myelogenous leukemia (CML) has unsatisfactory treatment efficacy at present. As the major component of red orpiment, tetra-arsenic tetra-sulfide (As4S4) has been recently used in treating leukemia, but with unclear mechanism targeting CML. MicroRNA (miR) is a group of endogenous non-coding RNAs regulating pathogenesis. MiR181 has been shown to exert important roles in tumor progression. The relationship between miR181 and As4S4 in inducing K562 cell apoptosis, however, is still unclear. Material/Methods CML cell line K562 was cultured in vitro in a control group and in groups receiving various dosages (20 μM and 40 μM) of As4S4. MTT assay was employed to detect the effect on K562 cell survival. MiR181 expression was quantified by real-time PCR. MTT assay and assay kit were used to determine K562 cell survival and caspase 3 expression. Cell apoptosis was assessed by flow cytometry. Bcl-2 expression was determined by real-time PCR and Western blotting. Results As4S4 significantly suppressed proliferation of K562 cells (p<0.05) and decreased miR181 expression, and increased caspase3 activity compared to the control group. It can induce K562 cell apoptosis via remarkably down-regulating mRNA and protein expressions of Bcl-2 (p<0.05). Conclusions As4S4 can facilitate K562 cell apoptosis via down-regulating miR181, inhibiting Bcl02 expression, and enhancing apoptotic protein caspase3 activity. PMID:28072759

  12. H2S cytotoxicity mechanism involves reactive oxygen species formation and mitochondrial depolarisation.

    PubMed

    Eghbal, Mohammad A; Pennefather, Peter S; O'Brien, Peter J

    2004-10-15

    A number of scavengers of reactive oxygen species (ROS) were found to be protective against cell death induced by hydrogen sulfide (H2S) in isolated hepatocytes. The H2O2 scavengers alpha-ketoglutarate and pyruvate, which also act as energy substrate metabolites, were more protective against H2S toxicity than lactate which is only an energy substrate metabolite. All of these results suggest that H2S toxicity is dependent on ROS production. We measured ROS formation directly in hepatocytes using the fluorogenic dichlorofluorescin method. H2S-induced ROS formation was dose dependent and pyruvate inhibited this ROS production. Non-toxic concentrations of H2S enhanced the cytotoxicity of H2O2 generated by glucose/glucose oxidase, which was inhibited by CYP450 inibitors. Furthermore, hepatocyte ROS formation induced by H2S was decreased by CYP450 inhibitors cimetidine and benzylimidazole. These results suggest that CYP450-dependant metabolism of H2S is responsible for inducing ROS production. H2S-induced cytotoxicity was preceded by mitochondrial depolarization as measured by rhodamine 123 fluorescence. Mitochondrial depolarization induced by H2S was prevented by zinc, methionine and pyruvate all of which decreased H2S-induced cell death. Treatment of H2S poisoning may benefit from interventions aimed at minimizing ROS-induced damage and reducing mitochondrial damage.

  13. Facile synthesis, structure, and properties of Ag2S/Ag heteronanostructure

    NASA Astrophysics Data System (ADS)

    Sadovnikov, S. I.; Gusev, A. I.

    2016-09-01

    Ag2S/Ag heteronanostructure has been produced by a simple one-stage chemical deposition from aqueous solutions of silver nitrate, sodium sulfide, and sodium citrate with the use of monochromatic light irradiation. For simultaneous synthesis of Ag2S and Ag nanoparticles, deposition has been performed from reaction mixtures with reduced sodium sulfide concentration. The size of Ag2S and Ag nanoparticles is 45-50 and 15-20 nm, respectively. It is established that in the contact layer between silver sulfide and silver, nonconducting α-Ag2S acanthite transforms into superionic β-Ag2S argentite under the action of external electric field. The scheme of the operation of a resistive switch based on an Ag2S/Ag heteronanostructure is proposed. The UV-Vis optical absorption spectra of colloidal solutions of Ag2S/Ag heteronanostructures have been studied.

  14. Electrical and optical characterization of green synthesized Gd2S3

    NASA Astrophysics Data System (ADS)

    Paul, Somnath; Sarkar, A.

    2016-05-01

    Gadolinium sulphide (Gd2S3) is a magnetic semiconductor with large band gap. Gd2S3 was synthesized following chemical and green techniques. Later process provides good stability of the nano clusters (NC) due to in-situ capping of Gd2S3 NC. It has been found that the optical band gap in Gd2S3 developed by green synthesis is lowered considerably over that in chemically synthesized Gd2S3. The green agencies used in this work are Jatropha Latex and dilute Garlic extract; both are enriched in sulphur and other organic polymer molecules. Simple observation shows that Gd2S3 NC retains residual magnetization. In this work optical and electrical characterization of the developed Gd2S3 specimens are carried out. The overall results obtained are good.

  15. Inflammatory effects of hypothermia and inhaled H2S during resuscitated, hyperdynamic murine septic shock.

    PubMed

    Wagner, Florian; Wagner, Katja; Weber, Sandra; Stahl, Bettina; Knöferl, Markus W; Huber-Lang, Markus; Seitz, Daniel H; Asfar, Pierre; Calzia, Enrico; Senftleben, Uwe; Gebhard, Florian; Georgieff, Michael; Radermacher, Peter; Hysa, Vladislava

    2011-04-01

    Inhaling hydrogen sulfide (H2S) reduced energy expenditure resulting in hypothermia. Because the inflammatory effects of either hypothermia alone or H2S per se still are a matter of debate, we tested the hypothesis whether inhaled H2S amplifies the hypothermia-related modulation of the inflammatory response. Fifteen hours after cecal ligation and puncture or sham laparotomy, anesthetized and mechanically ventilated normothermic and hypothermic mice (core temperature kept at 38°C and 27°C, respectively) received either 100 ppm H2S or vehicle. In the sham-operated animals, inhaled H2S and hypothermia alone comparably reduced the plasma chemokine and IL-6 levels, but combining hypothermia and inhaled H2S had no additional effect. The lung tissue cytokine and chemokine patterns revealed a similar response. During sepsis, inhaled H2S reduced the blood cytokine concentrations only, without effects on the plasma chemokine or the lung tissue levels. Again, inhaled H2S had no major additional effect during hypothermia. With or without sepsis, inhaled H2S and hypothermia alone comparably reduced the lung tissue heme oxygenase 1 expression, whereas inhaled H2S had no additional effect during hypothermia. Lung tissue nuclear transcription factor κB activation was reduced by combining H2S with hypothermia in the sham-operated animals, whereas it was increased by inhaled H2S during sepsis. Hypothermia amplified this response. Hence, during anesthesia and mechanical ventilation, inhaled H2S exerted anti-inflammatory effects, which were, however, not amplified by adding deliberate hypothermia. Sepsis attenuated these anti-inflammatory effects of inhaled H2S, which were at least in part independent of the nuclear transcription factor κB pathway.

  16. Metabolism of 2S-hydroxy-3-methylcholanthrene by rat liver microsomes.

    PubMed

    Shou, M G; Yang, S K

    1990-11-01

    Products formed in the metabolism of 2S-hydroxy-3-methylcholanthrene (2S-OH-3MC) by liver microsomes prepared from phenobarbital-treated rats were isolated by sequential use of reversed-phase and normal-phase HPLC. Metabolites of 2S-OH-3MC were characterized by UV-visible absorption, mass and circular dichroic spectra, and chiral stationary phase HPLC analyses. The metabolites that had been identified were 2S-hydroxy-3-hydroxymethylcholanthrene (2S-OH-3-OHMC), 3MC-2-one, 3MC-2-one 9,10-dihydrodiol, 8-hydroxy-2S-OH-3MC, a pair of stereoisomers 3MC (trans)-1R,2R-diol and (cis)-1S,2R-diol in a ratio of approximately 11:89, a pair of diastereomers 2S-OH-3MC 9R,10R-dihydrodiol and 2S-OH-3MC 9S,10S-dihydrodiol in a ratio of approximately 9:1, and a pair of diastereomers 2S-OH-3MC 11R,12R-dihydrodiol and 2S-OH-3MC 11S,12S-dihydrodiol in a ratio of approximately 77:23. A few tentatively identified minor metabolites were 3-OHMC trans-1R,2R-diol, 10-hydroxy-2S-OH-3MC, a 9,10-dihydrodiol derived from 3MC cis-1S,2R-diol, and a 11,12-dihydrodiol and two diastereomeric 9,10-dihydrodiols derived from 2S-OH-3-OHMC. Since the racemic 2-OH-3MC is a known potent carcinogen and 2S-OH-3MC is the most abundant metabolite of 3MC, some of the 2S-OH-3MC metabolites identified in this study may be further converted to proximate and ultimate carcinogens which may contribute to the overall carcinogenicity exhibited by 3MC.

  17. Fabrication and characterization of a nanostructured TiO2/In2S3-Sb2S3/CuSCN extremely thin absorber (eta) solar cell

    NASA Astrophysics Data System (ADS)

    Huerta-Flores, Alí M.; García-Gómez, Nora A.; de la Parra-Arciniega, Salomé M.; Sánchez, Eduardo M.

    2016-08-01

    In this work we report the successful assembly and characterization of a TiO2/In2S3-Sb2S3/CuSCN extremely thin absorber solar cell. Nanostructured TiO2 deposited by screen printing on an ITO substrate was used as an n-type electrode. An ∼80 nm extremely thin layer of the system In2S3-Sb2S3 deposited by successive ionic layer adsorption and a reaction (silar) method was used as an absorber. The voids were filled with p-type CuSCN and the entire assembly was completed with a gold contact. The solar cell fabricated with this heterostructure showed an energy conversion efficiency of 4.9%, which is a promising result in the development of low cost and simple fabrication of solar cells.

  18. Magnetic properties of (FeIn{sub 2}S{sub 4}){sub 1-x}(In{sub 2}S{sub 3}){sub x} alloy single crystals

    SciTech Connect

    Bodnar, I. V. Novikova, M. A.; Trukhanov, S. V.

    2013-05-15

    (FeIn{sub 2}S{sub 4}){sub 1-x}(In{sub 2}S{sub 3}){sub x} alloy single crystals are grown by oriented crystallization in the entire range of component concentrations. For the single crystals, studies of the magnetic properties are carried out in the temperature range 4-300 K and the magnetic-field range 0-14 T. It is established that almost all of the alloys are paramagnetic materials at temperatures down to the lowest achievable temperatures ({approx}4 K). It is shown that the ground magnetic phase state of the alloys is the spin-glass state with the freezing temperature steadily increasing with increasing Fe{sup 2+} cation content. The most probable causes and mechanism of formation of the magnetic state of the (FeIn{sub 2}S{sub 4}){sub 1-x}(In{sub 2}S{sub 3}){sub x} crystals are discussed.

  19. Differential Expression of Melanopsin Isoforms Opn4L and Opn4S during Postnatal Development of the Mouse Retina

    PubMed Central

    Hughes, Steven; Welsh, Laura; Katti, Christiana; González-Menéndez, Irene; Turton, Michael; Halford, Stephanie; Sekaran, Sumathi; Peirson, Stuart N.; Hankins, Mark W.; Foster, Russell G.

    2012-01-01

    Photosensitive retinal ganglion cells (pRGCs) respond to light from birth and represent the earliest known light detection system to develop in the mouse retina. A number of morphologically and functionally distinct subtypes of pRGCs have been described in the adult retina, and have been linked to different physiological roles. We have previously identified two distinct isoforms of mouse melanopsin, Opn4L and Opn4S, which are generated by alternate splicing of the Opn4 locus. These isoforms are differentially expressed in pRGC subtypes of the adult mouse retina, with both Opn4L and Opn4S detected in M1 type pRGCs, and only Opn4L detected in M2 type pRGCs. Here we investigate the developmental expression of Opn4L and Opn4S and show a differential profile of expression during postnatal development. Opn4S mRNA is detected at relatively constant levels throughout postnatal development, with levels of Opn4S protein showing a marked increase between P0 and P3, and then increasing progressively over time until adult levels are reached by P10. By contrast, levels of Opn4L mRNA and protein are low at birth and show a marked increase at P14 and P30 compared to earlier time points. We suggest that these differing profiles of expression are associated with the functional maturation of M1 and M2 subtypes of pRGCs. Based upon our data, Opn4S expressing M1 type pRGCs mature first and are the dominant pRGC subtype in the neonate retina, whereas increased expression of Opn4L and the maturation of M2 type pRGCs occurs later, between P10 and P14, at a similar time to the maturation of rod and cone photoreceptors. We suggest that the distinct functions associated with these cell types will develop at different times during postnatal development. PMID:22496826

  20. Differential expression of melanopsin isoforms Opn4L and Opn4S during postnatal development of the mouse retina.

    PubMed

    Hughes, Steven; Welsh, Laura; Katti, Christiana; González-Menéndez, Irene; Turton, Michael; Halford, Stephanie; Sekaran, Sumathi; Peirson, Stuart N; Hankins, Mark W; Foster, Russell G

    2012-01-01

    Photosensitive retinal ganglion cells (pRGCs) respond to light from birth and represent the earliest known light detection system to develop in the mouse retina. A number of morphologically and functionally distinct subtypes of pRGCs have been described in the adult retina, and have been linked to different physiological roles. We have previously identified two distinct isoforms of mouse melanopsin, Opn4L and Opn4S, which are generated by alternate splicing of the Opn4 locus. These isoforms are differentially expressed in pRGC subtypes of the adult mouse retina, with both Opn4L and Opn4S detected in M1 type pRGCs, and only Opn4L detected in M2 type pRGCs. Here we investigate the developmental expression of Opn4L and Opn4S and show a differential profile of expression during postnatal development. Opn4S mRNA is detected at relatively constant levels throughout postnatal development, with levels of Opn4S protein showing a marked increase between P0 and P3, and then increasing progressively over time until adult levels are reached by P10. By contrast, levels of Opn4L mRNA and protein are low at birth and show a marked increase at P14 and P30 compared to earlier time points. We suggest that these differing profiles of expression are associated with the functional maturation of M1 and M2 subtypes of pRGCs. Based upon our data, Opn4S expressing M1 type pRGCs mature first and are the dominant pRGC subtype in the neonate retina, whereas increased expression of Opn4L and the maturation of M2 type pRGCs occurs later, between P10 and P14, at a similar time to the maturation of rod and cone photoreceptors. We suggest that the distinct functions associated with these cell types will develop at different times during postnatal development.

  1. Study of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the Υ(4S)

    NASA Astrophysics Data System (ADS)

    Aubert, B.; Boutigny, D.; Gaillard, J.-M.; Hicheur, A.; Karyotakis, Y.; Lees, J. P.; Robbe, P.; Tisserand, V.; Palano, A.; Pompili, A.; Chen, G. P.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Stugu, B.; Abrams, G. S.; Borgland, A. W.; Breon, A. B.; Brown, D. N.; Button-Shafer, J.; Cahn, R. N.; Clark, A. R.; Gill, M. S.; Gritsan, A. V.; Groysman, Y.; Jacobsen, R. G.; Kadel, R. W.; Kadyk, J.; Kerth, L. T.; Kolomensky, Yu. G.; Kral, J. F.; Leclerc, C.; Levi, M. E.; Lynch, G.; Oddone, P. J.; Pripstein, M.; Roe, N. A.; Romosan, A.; Ronan, M. T.; Shelkov, V. G.; Telnov, A. V.; Wenzel, W. A.; Harrison, T. J.; Hawkes, C. M.; Knowles, D. J.; O'Neale, S. W.; Penny, R. C.; Watson, A. T.; Watson, N. K.; Deppermann, T.; Goetzen, K.; Koch, H.; Kunze, M.; Lewandowski, B.; Peters, K.; Schmuecker, H.; Steinke, M.; Barlow, N. R.; Bhimji, W.; Chevalier, N.; Clark, P. J.; Cottingham, W. N.; Foster, B.; Mackay, C.; Wilson, F. F.; Abe, K.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Thiessen, D.; Jolly, S.; McKemey, A. K.; Blinov, V. E.; Bukin, A. D.; Bukin, D. A.; Buzykaev, A. R.; Golubev, V. B.; Ivanchenko, V. N.; Korol, A. A.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Telnov, V. I.; Yushkov, A. N.; Best, D.; Chao, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; McMahon, S.; Stoker, D. P.; Arisaka, K.; Buchanan, C.; Chun, S.; Macfarlane, D. B.; Prell, S.; Rahatlou, Sh.; Raven, G.; Sharma, V.; Campagnari, C.; Dahmes, B.; Hart, P. A.; Kuznetsova, N.; Levy, S. L.; Long, O.; Lu, A.; Mazur, M. A.; Richman, J. D.; Verkerke, W.; Beringer, J.; Eisner, A. M.; Grothe, M.; Heusch, C. A.; Lockman, W. S.; Pulliam, T.; Schalk, T.; Schmitz, R. E.; Schumm, B. A.; Seiden, A.; Turri, M.; Walkowiak, W.; Williams, D. C.; Wilson, M. G.; Chen, E.; Dubois-Felsmann, G. P.; Dvoretskii, A.; Hitlin, D. G.; Metzler, S.; Oyang, J.; Porter, F. C.; Ryd, A.; Samuel, A.; Weaver, M.; Yang, S.; Zhu, R. Y.; Devmal, S.; Geld, T. L.; Jayatilleke, S.; Mancinelli, G.; Meadows, B. T.; Sokoloff, M. D.; Barillari, T.; Bloom, P.; Dima, M. O.; Ford, W. T.; Nauenberg, U.; Olivas, A.; Rankin, P.; Roy, J.; Smith, J. G.; van Hoek, W. C.; Blouw, J.; Harton, J. L.; Krishnamurthy, M.; Soffer, A.; Toki, W. H.; Wilson, R. J.; Zhang, J.; Brandt, T.; Brose, J.; Colberg, T.; Dickopp, M.; Dubitzky, R. S.; Hauke, A.; Maly, E.; Müller-Pfefferkorn, R.; Otto, S.; Schubert, K. R.; Schwierz, R.; Spaan, B.; Wilden, L.; Bernard, D.; Bonneaud, G. R.; Brochard, F.; Cohen-Tanugi, J.; Ferrag, S.; T'jampens, S.; Thiebaux, Ch.; Vasileiadis, G.; Verderi, M.; Anjomshoaa, A.; Bernet, R.; Khan, A.; Lavin, D.; Muheim, F.; Playfer, S.; Swain, J. E.; Tinslay, J.; Falbo, M.; Borean, C.; Bozzi, C.; Piemontese, L.; Treadwell, E.; Anulli, F.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Falciai, D.; Finocchiaro, G.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Xie, Y.; Zallo, A.; Bagnasco, S.; Buzzo, A.; Contri, R.; Crosetti, G.; Lo Vetere, M.; Macri, M.; Monge, M. R.; Passaggio, S.; Pastore, F. C.; Patrignani, C.; Pia, M. G.; Robutti, E.; Santroni, A.; Tosi, S.; Morii, M.; Bartoldus, R.; Hamilton, R.; Mallik, U.; Cochran, J.; Crawley, H. B.; Fischer, P.-A.; Lamsa, J.; Meyer, W. T.; Rosenberg, E. I.; Grosdidier, G.; Hast, C.; Höcker, A.; Lacker, H. M.; Laplace, S.; Lepeltier, V.; Lutz, A. M.; Plaszczynski, S.; Schune, M. H.; Trincaz-Duvoid, S.; Wormser, G.; Bionta, R. M.; Brigljević, V.; Lange, D. J.; Mugge, M.; van Bibber, K.; Wright, D. M.; Bevan, A. J.; Fry, J. R.; Gabathuler, E.; Gamet, R.; George, M.; Kay, M.; Payne, D. J.; Sloane, R. J.; Touramanis, C.; Aspinwall, M. L.; Bowerman, D. A.; Dauncey, P. D.; Egede, U.; Eschrich, I.; Gunawardane, N. J.; Nash, J. A.; Sanders, P.; Smith, D.; Azzopardi, D. E.; Back, J. J.; Bellodi, G.; Dixon, P.; Harrison, P. F.; Potter, R. J.; Shorthouse, H. W.; Strother, P.; Vidal, P. B.; Cowan, G.; George, S.; Green, M. G.; Kurup, A.; Marker, C. E.; McGrath, P.; McMahon, T. R.; Ricciardi, S.; Salvatore, F.; Vaitsas, G.; Brown, D.; Davis, C. L.; Allison, J.; Barlow, R. J.; Boyd, J. T.; Forti, A. C.; Fullwood, J.; Jackson, F.; Lafferty, G. D.; Savvas, N.; Weatherall, J. H.; Williams, J. C.; Farbin, A.; Jawahery, A.; Lillard, V.; Olsen, J.; Roberts, D. A.; Schieck, J. R.; Blaylock, G.; Dallapiccola, C.; Flood, K. T.; Hertzbach, S. S.; Kofler, R.; Koptchev, V. B.; Moore, T. B.; Staengle, H.; Willocq, S.; Brau, B.; Cowan, R.; Sciolla, G.; Taylor, F.; Yamamoto, R. K.; Milek, M.; Patel, P. M.; Palombo, F.; Bauer, J. M.; Cremaldi, L.; Eschenburg, V.; Kroeger, R.; Reidy, J.; Sanders, D. A.; Summers, D. J.; Nief, J. Y.; Taras, P.; Nicholson, H.; Cartaro, C.; Cavallo, N.; de Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Paolucci, P.; Piccolo, D.; Sciacca, C.; Losecco, J. M.; Alsmiller, J. R.; Gabriel, T. A.; Brau, J.; Frey, R.; Grauges, E.; Iwasaki, M.; Sinev, N. B.; Strom, D.; Colecchia, F.; dal Corso, F.; Dorigo, A.; Galeazzi, F.; Margoni, M.; Michelon, G.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Torassa, E.; Voci, C.; Benayoun, M.; Briand, H.; Chauveau, J.; David, P.; de La Vaissière, Ch.; del Buono, L.; Hamon, O.; Le Diberder, F.; Leruste, Ph.; Ocariz, J.; Roos, L.; Stark, J.; Manfredi, P. F.; Re, V.; Speziali, V.; Frank, E. D.; Gladney, L.; Guo, Q. H.; Panetta, J.; Angelini, C.; Batignani, G.; Bettarini, S.; Bondioli, M.; Bucci, F.; Campagna, E.; Carpinelli, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Marchiori, G.; Martinez-Vidal, F.; Morganti, M.; Neri, N.; Paoloni, E.; Rama, M.; Rizzo, G.; Sandrelli, F.; Simi, G.; Triggiani, G.; Walsh, J.; Haire, M.; Judd, D.; Paick, K.; Turnbull, L.; Wagoner, D. E.; Albert, J.; Elmer, P.; Lu, C.; Miftakov, V.; Schaffner, S. F.; Smith, A. J.; Tumanov, A.; Varnes, E. W.; Cavoto, G.; del Re, D.; Ferrarotto, F.; Ferroni, F.; Lamanna, E.; Mazzoni, M. A.; Morganti, S.; Piredda, G.; Safai Tehrani, F.; Serra, M.; Voena, C.; Faccini, R.; Christ, S.; Waldi, R.; Adye, T.; de Groot, N.; Franek, B.; Geddes, N. I.; Gopal, G. P.; Xella, S. M.; Aleksan, R.; Emery, S.; Gaidot, A.; Ganzhur, S. F.; Giraud, P.-F.; Hamel de Monchenault, G.; Kozanecki, W.; Langer, M.; London, G. W.; Mayer, B.; Serfass, B.; Vasseur, G.; Yèche, Ch.; Zito, M.; Purohit, M. V.; Singh, H.; Weidemann, A. W.; Yumiceva, F. X.; Adam, I.; Aston, D.; Berger, N.; Boyarski, A. M.; Calderini, G.; Convery, M. R.; Coupal, D. P.; Dong, D.; Dorfan, J.; Dunwoodie, W.; Field, R. C.; Glanzman, T.; Gowdy, S. J.; Haas, T.; Halyo, V.; Himel, T.; Hryn'ova, T.; Huffer, M. E.; Innes, W. R.; Jessop, C. P.; Kelsey, M. H.; Kim, P.; Kocian, M. L.; Langenegger, U.; Leith, D. W.; Luitz, S.; Luth, V.; Lynch, H. L.; Marsiske, H.; Menke, S.; Messner, R.; Muller, D. R.; O'Grady, C. P.; Ozcan, V. E.; Perazzo, A.; Perl, M.; Petrak, S.; Quinn, H.; Ratcliff, B. N.; Robertson, S. H.; Roodman, A.; Salnikov, A. A.; Schietinger, T.; Schindler, R. H.; Schwiening, J.; Snyder, A.; Soha, A.; Spanier, S. M.; Stelzer, J.; Su, D.; Sullivan, M. K.; Tanaka, H. A.; Va'Vra, J.; Wagner, S. R.; Weinstein, A. J.; Wisniewski, W. J.; Wright, D. H.; Young, C. C.; Burchat, P. R.; Cheng, C. H.; Meyer, T. I.; Roat, C.; Henderson, R.; Bugg, W.; Cohn, H.; Izen, J. M.; Kitayama, I.; Lou, X. C.; Bianchi, F.; Bona, M.; Gamba, D.; Bosisio, L.; della Ricca, G.; Dittongo, S.; Lanceri, L.; Poropat, P.; Vuagnin, G.; Panvini, R. S.; Brown, C. M.; Jackson, P. D.; Kowalewski, R.; Roney, J. M.; Band, H. R.; Charles, E.; Dasu, S.; Eichenbaum, A. M.; Hu, H.; Johnson, J. R.; Liu, R.; di Lodovico, F.; Pan, Y.; Prepost, R.; Scott, I. J.; Sekula, S. J.; von Wimmersperg-Toeller, J. H.; Wu, S. L.; Yu, Z.; Kordich, T. M.; Neal, H.

    2002-08-01

    We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at the Stanford Linear Accelerator Center. The data sample consists of 29.7 fb-1 recorded at the Υ(4S) resonance and 3.9 fb-1 off resonance. One of the neutral B mesons, which are produced in pairs at the Υ(4S), is fully reconstructed in the CP decay modes J/ψK0S, ψ(2S)K0S, χc1K0S, J/ψK*0 (K*0-->K0Sπ0) and J/ψK0L, or in flavor-eigenstate modes involving D(*)π/ρ/a1 and J/ψK*0 (K*0-->K+π-). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. A neural network tagging algorithm is used to recover events without a clear lepton or kaon tag. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. Wrong-tag probabilities, the time-difference resolution function, and the B0-B0 oscillation frequency Δmd are measured with a sample of about 6350 fully-reconstructed B0 decays in hadronic flavor-eigenstate modes. A maximum-likelihood fit to this flavor eigenstate sample finds Δmd=0.516+/-0.016(stat)+/-0.010(syst) ps-1. The value of the asymmetry amplitude sin 2β is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged B0 decays in the CP-eigenstate modes. We find sin 2β=0.59+/-0.14(stat)+/-0.05(syst), demonstrating that CP violation exists in the neutral B meson system. We also determine the value of the CP violation parameter |λ|=0.93+/-0.09(stat)+/-0.03(syst), which is consistent with the expectation of |λ|=1 for no direct CP violation.

  2. In Situ Growth of In2S3 Nanorods in Poly(3-Hexylthiophene) Hybrid Films

    NASA Astrophysics Data System (ADS)

    Cota-Leal, M.; Sotelo-Lerma, M.; Corona-Corona, I.; Quevedo-Lopez, M. A.

    2016-04-01

    A novel and efficient gas-liquid method for the in situ synthesis of In2S3 nanorods in a poly(3-hexylthiophene) (P3HT) matrix is demonstrated. The method involves a self-contained reaction between Na2S and HCl that produces H2S, which reacts with a P3HT/InCl3 solution resulting in hybrid P3HT/In2S3 films. The Na2S solution is regenerated for further use. The method yielded results in In2S3 nanoparticles and nanorods in a P3HT matrix, as observed by transmission electron microscopy. The In2S3 nanorods are 3 nm wide and ~30 nm long. The size of the nanorods is dependent on the P3HT concentration. The band gap (E g) of the resulting In2S3/P3HT is in the range of 2.97-3.71 eV, as measured by UV-visible spectroscopy (UV-Vis) Charge transfer in the In2S3/P3HT was demonstrated by the presence of quenching in the fluorescence spectra of the composite. Chemical composition was investigated by energy dispersive x-ray spectroscopy analysis, as well as x-ray photoelectron spectroscopy. Both techniques demonstrated the formation of In2S3.

  3. Reduced Glutathione Mediates Resistance to H2S Toxicity in Oral Streptococci

    PubMed Central

    Ooi, Xi Jia

    2016-01-01

    Periodontal disease is associated with changes in the composition of the oral microflora, where health-associated oral streptococci decrease while Gram-negative anaerobes predominate in disease. A key feature of periodontal disease-associated anaerobes is their ability to produce hydrogen sulfide (H2S) abundantly as a by-product of anaerobic metabolism. So far, H2S has been reported to be either cytoprotective or cytotoxic by modulating bacterial antioxidant defense systems. Although oral anaerobes produce large amounts of H2S, the potential effects of H2S on oral streptococci are currently unknown. The aim of this study was to determine the effects of H2S on the survival and biofilm formation of oral streptococci. The growth and biofilm formation of Streptococcus mitis and Streptococcus oralis were inhibited by H2S. However, H2S did not significantly affect the growth of Streptococcus gordonii or Streptococcus sanguinis. The differential susceptibility of oral streptococci to H2S was attributed to differences in the intracellular concentrations of reduced glutathione (GSH). In the absence of GSH, H2S elicited its toxicity through an iron-dependent mechanism. Collectively, our results showed that H2S exerts antimicrobial effects on certain oral streptococci, potentially contributing to the decrease in health-associated plaque microflora. PMID:26801579

  4. Two's company, three's a crowd: can H2S be the third endogenous gaseous transmitter?

    PubMed

    Wang, Rui

    2002-11-01

    Bearing the public image of a deadly "gas of rotten eggs," hydrogen sulfide (H2S) can be generated in many types of mammalian cells. Functionally, H2S has been implicated in the induction of hippocampal long-term potentiation, brain development, and blood pressure regulation. By acting specifically on KATP channels, H2S can hyperpolarize cell membranes, relax smooth muscle cells, or decrease neuronal excitability. The endogenous metabolism and physiological functions of H2S position this gas well in the novel family of endogenous gaseous transmitters, termed "gasotransmitters." It is hypothesized that H2S is the third endogenous signaling gasotransmitter, besides nitric oxide and carbon monoxide. This positioning of H2S will open an exciting field-H2S physiology-encompassing realization of the interaction of H2S and other gasotransmitters, sulfurating modification of proteins, and the functional role of H2S in multiple systems. It may shed light on the pathogenesis of many diseases related to the abnormal metabolism of H2S.

  5. Reduced Glutathione Mediates Resistance to H2S Toxicity in Oral Streptococci.

    PubMed

    Ooi, Xi Jia; Tan, Kai Soo

    2016-01-22

    Periodontal disease is associated with changes in the composition of the oral microflora, where health-associated oral streptococci decrease while Gram-negative anaerobes predominate in disease. A key feature of periodontal disease-associated anaerobes is their ability to produce hydrogen sulfide (H2S) abundantly as a by-product of anaerobic metabolism. So far, H2S has been reported to be either cytoprotective or cytotoxic by modulating bacterial antioxidant defense systems. Although oral anaerobes produce large amounts of H2S, the potential effects of H2S on oral streptococci are currently unknown. The aim of this study was to determine the effects of H2S on the survival and biofilm formation of oral streptococci. The growth and biofilm formation of Streptococcus mitis and Streptococcus oralis were inhibited by H2S. However, H2S did not significantly affect the growth of Streptococcus gordonii or Streptococcus sanguinis. The differential susceptibility of oral streptococci to H2S was attributed to differences in the intracellular concentrations of reduced glutathione (GSH). In the absence of GSH, H2S elicited its toxicity through an iron-dependent mechanism. Collectively, our results showed that H2S exerts antimicrobial effects on certain oral streptococci, potentially contributing to the decrease in health-associated plaque microflora.

  6. Brain, Learning, and Memory: Role of H2S in Neurodegenerative Diseases.

    PubMed

    Nagpure, B V; Bian, Jin-Song

    2015-01-01

    For more than 300 years, the toxicity of hydrogen sulfide (H2S) has been known to mankind. However, this point of view is changing as an increased interest was observed in H2S biology in the last two decades. The scientific community has succeeded to unravel many important physiological and pathological effects of H2S on mammalian body systems. Thus, H2S is now referred to as a third endogenous gaseous mediator along with nitric oxide and carbon monoxide. Acting as a neuromodulator, H2S facilitates long-term potentiation and regulates intracellular calcium levels, which are important processes in learning and memory. Aberrant endogenous production and metabolism of H2S are implicated in pathogenesis of neurodegenerative diseases including Alzheimer's disease (AD) and Parkinson's disease (PD). Various H2S donors have shown beneficial therapeutic effects in neurodegenerative disease models by targeting hallmark pathological events (e.g., amyloid-β production in AD and neuroinflammation in PD). The results obtained from many in vivo studies clearly show that H2S not only prevents neuronal and synaptic deterioration but also improves deficits in memory, cognition, and learning. The anti-inflammatory, antioxidant, and anti-apoptotic effects of H2S underlie its neuroprotective properties. In this chapter, we will overview the current understanding of H2S in context of neurodegenerative diseases, with special emphasis on its corrective effects on impaired learning, memory, and cognition.

  7. Medicinal Chemistry: Insights into the Development of Novel H2S Donors.

    PubMed

    Zhao, Yu; Pacheco, Armando; Xian, Ming

    2015-01-01

    Hydrogen sulfide (H2S) was traditionally considered as a toxic gas. However, recent studies have demonstrated H2S is an endogenously generated gaseous signaling molecule (gasotransmitter) with importance on par with that of two other well-known endogenous gasotransmitters, nitric oxide (NO) and carbon monoxide (CO). Although H2S's exact mechanisms of action are still under investigation, the production of endogenous H2S and the exogenous administration of H2S have been demonstrated to elicit a wide range of physiological responses including modulation of blood pressure and protection of ischemia reperfusion injury, exertion of anti-inflammatory effects, and reduction of metabolic rate. These results strongly suggest that modulation of H2S levels could have potential therapeutic values. In this regard, synthetic H2S-releasing agents (i.e., H2S donors) are not only important research tools, but also potential therapeutic agents. This chapter summarizes the knowledge of currently available H2S donors. Their preparation, H2S releasing mechanisms, and biological applications are discussed.

  8. Differential effects of statins on endogenous H2S formation in perivascular adipose tissue.

    PubMed

    Wójcicka, Grażyna; Jamroz-Wiśniewska, Anna; Atanasova, Pepa; Chaldakov, George N; Chylińska-Kula, Beata; Bełtowski, Jerzy

    2011-01-01

    Hydrogen sulfide (H(2)S) is a new gasotransmitter synthesized enzymatically from l-cysteine in cytosol and is oxidized in mitochondria. In the cardiovascular system, H(2)S regulates vascular tone, inhibits atherogenesis, and protects against myocardial ischemia-reperfusion injury. We examined the effect of statins on vascular H(2)S production. Male Wistar rats received pravastatin (40mg/kg/day) or atorvastatin (20mg/kg/day) for 3 weeks and then H(2)S formation was measured in aortic media, periaortic adipose tissue (PAAT) and the liver. Only atorvastatin increased H(2)S production in PAAT whereas both statins stimulated its formation in the liver. Neither statin affected H(2)S production in aortic media. H(2)S formation in post-mitochondrial supernatant was higher than in mitochondria-containing supernatant and was not influenced by statins in any tissue. In addition, oxidation of exogenous H(2)S in isolated liver mitochondria was slower in statin-treated than in control rats. These data indicate that statins increase net H(2)S production by inhibiting its mitochondrial oxidation. Statins had no effect on the activity of H(2)S-metabolizing enzyme, sulfide:quinone oxidoreductase, measured at saturating coenzyme Q concentration. Both statins reduced CoQ(9) concentration in plasma and liver, but only atorvastatin decreased CoQ(9) in PAAT. Atorvastatin attenuated phenylephrine-induced contraction of PAAT+ but not of PAAT- aortic rings. Effects of atorvastatin on net H(2)S production, mitochondrial H(2)S oxidation and aortic contractility were abolished by supplementation of exogenous CoQ(9). In conclusion, lipophilic atorvastatin, but not hydrophilic pravastatin, increases net H(2)S production in perivascular adipose tissue by inhibiting its mitochondrial oxidation. This effect is mediated by statin-induced CoQ(9) deficiency and results in the augmentation of anticontractile effect of perivascular adipose tissue.

  9. Two-dimensional polymeric [Hg4(μ2-I)6I2(μ2-C4S6)]n

    PubMed Central

    Hameau, Aurélien; Guyon, Fabrice; Knorr, Michael; Colquhoun, Victoria P.; Strohmann, Carsten

    2011-01-01

    The title compound, poly[(μ2-2H,5H-1,3-dithiolo[4,5-d][1,3]di­thiole-2,5-dithione)hexa-μ2-iodido-diiodidotetra­mercury(II)], [Hg4I8(C4S6)]n, represents the first example of a coordination polymer assembled by the α,α-C4S6 dithione ligand. The HgII ions are four-coordinated in a distorted tetra­hedral geometry, the coordination demand being satisfied either by four bridging iodide ligands or by three iodide ligands (one terminal and two bridging) and a thio­carbonyl S atom. Due to the bridging nature of the dithione ligand, the coordination polymer has a two-dimensional structure, built up of undulated layers parallel to (001). There is an inversion center at the mid-point of the central C=C double bond. PMID:21522307

  10. Phosphorylation of BK channels modulates the sensitivity to hydrogen sulfide (H2S)

    PubMed Central

    Sitdikova, Guzel F.; Fuchs, Roman; Kainz, Verena; Weiger, Thomas M.; Hermann, Anton

    2014-01-01

    Introduction: Gases, such as nitric oxide (NO), carbon monoxide (CO), or hydrogen sulfide (H2S), termed gasotransmitters, play an increasingly important role in understanding of how electrical signaling of cells is modulated. H2S is well-known to act on various ion channels and receptors. In a previous study we reported that H2S increased calcium-activated potassium (BK) channel activity. Aims: The goal of the present study is to investigate the modulatory effect of BK channel phosphorylation on the action of H2S on the channel as well as to recalculate and determine the H2S concentrations in aqueous sodium hydrogen sulfide (NaHS) solutions. Methods: Single channel recordings of GH3, GH4, and GH4 STREX cells were used to analyze channel open probability, amplitude, and open dwell times. H2S was measured with an anion selective electrode. Results: The concentration of H2S produced from NaHS was recalculated taking pH, temperature salinity of the perfusate, and evaporation of H2S into account. The results indicate that from a concentration of 300 μM NaHS, only 11–13%, i.e., 34–41 μM is effective as H2S in solution. GH3, GH4, and GH4 STREX cells respond differently to phosphorylation. BK channel open probability (Po) of all cells lines used was increased by H2S in ATP-containing solutions. PKA prevented the action of H2S on channel Po in GH4 and GH4 STREX, but not in GH3 cells. H2S, high significantly increased Po of all PKG pretreated cells. In the presence of PKC, which lowers channel activity, H2S increased channel Po of GH4 and GH4 STREX, but not those of GH3 cells. H2S increased open dwell times of GH3 cells in the absence of ATP significantly. A significant increase of dwell times with H2S was also observed in the presence of okadaic acid. Conclusions: Our results suggest that phosphorylation by PKG primes the channels for H2S activation and indicate that channel phosphorylation plays an important role in the response to H2S. PMID:25429270

  11. Thionation of Tryptanthrin, Rutaecarpine, and Related Molecules with a Reagent Prepared from P4S10 and Pyridine.

    PubMed

    Kingi, Ngarita; Bergman, Jan

    2016-09-02

    Reaction of P4S10 in hot pyridine produces a crystalline solid which can be collected and used for thionations in other solvents such as acetonitrile and sulfolane. The biologically active natural products tryptanthrine, rutaecarpine, 7,8-dehydrorutaecarpine, and some related compounds have now been converted to thionated versions simply by heating the molecules with this thionating reagent in sulfolane (typically at 135 °C for 20 min) followed by a workup in water. No chromatography was necessary.

  12. A Guided-Ion Beam Study of the O+(4S) + NH3 System at Hyperthermal Energies

    DTIC Science & Technology

    2008-07-14

    higher Ej, is typical of exothermic- charge transfer in polyatomic systems. In either case, however, there are coincident ions , namely OH+ and D20...REPRINT 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE A Guided- Ion Beam Study of the 0+(4S) + NH3 System at Hyperthermal Energies 5a. CONTRACT...from near-thermal to approximately 15 eV, using the guided- ion beam (GIB) method. Measurements were also performed using ammonia-^ to aid in mass

  13. Spectroscopic Studies on the [4Fe-4S] Cluster in Adenosine 5′-Phosphosulfate Reductase from Mycobacterium tuberculosis

    PubMed Central

    Bhave, Devayani P.; Hong, Jiyoung A.; Lee, Michael; Jiang, Wei; Krebs, Carsten; Carroll, Kate S.

    2011-01-01

    Mycobacterium tuberculosis adenosine 5′-phosphosulfate reductase (MtAPR) is an iron-sulfur protein and a validated target to develop new antitubercular agents, particularly for the treatment of latent infection. The enzyme harbors a [4Fe-4S]2+ cluster that is coordinated by four cysteinyl ligands, two of which are adjacent in the amino acid sequence. The iron-sulfur cluster is essential for catalysis; however, the precise role of the [4Fe-4S] cluster in APR remains unknown. Progress in this area has been hampered by the failure to generate a paramagnetic state of the [4Fe-4S] cluster that can be studied by electron paramagnetic resonance spectroscopy. Herein, we overcome this limitation and report the EPR spectra of MtAPR in the [4Fe-4S]+ state. The EPR signal is rhombic and consists of two overlapping S = ½ species. Substrate binding to MtAPR led to a marked increase in the intensity and resolution of the EPR signal and to minor shifts in principle g values that were not observed among a panel of substrate analogs, including adenosine 5′-diphosphate. Using site-directed mutagenesis, in conjunction with kinetic and EPR studies, we have also identified an essential role for the active site residue Lys-144, whose side chain interacts with both the iron-sulfur cluster and the sulfate group of adenosine 5′-phosphosulfate. The implications of these findings are discussed with respect to the role of the iron-sulfur cluster in the catalytic mechanism of APR. PMID:21075841

  14. Nqrs Data for C9H12D4LiNO4S (Subst. No. 1188)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume A `Substances Containing Ag … C10H15' of Volume 48 `Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III `Condensed Matter'. It contains an extract of Section `3.2 Data tables' of the Chapter `3 Nuclear quadrupole resonance data' providing the NQRS data for C9H12D4LiNO4S (Subst. No. 1188)

  15. In situ high throughput method for H(2)S detection during micro-scale wine fermentation.

    PubMed

    Winter, Gal; Curtin, Chris

    2012-10-01

    An in situ high throughput method for the detection of H(2)S during fermentation was developed. The method utilizes a redox reaction in which sulfide ion reduces methylene blue, leading to its decolourisation. Incorporation of methylene blue into the fermentation media allows real-time detection of H(2)S during fermentation and the generation of an H(2)S production profile. Kinetic parameters extracted from the H(2)S production profile can be used to characterise genetic factors affecting H(2)S production and differentiate between environmental conditions affecting it. The method, validated here for Saccharomyces cerevisiae, is suited for high throughput screening purposes by virtue of its simplicity and the ability to detect H(2)S in micro-scale fermentations.

  16. Sulfur isotope effects associated with protonation of HS- and volatilization of H2S

    NASA Technical Reports Server (NTRS)

    Fry, B.; Gest, H.; Hayes, J. M.

    1986-01-01

    The isotope effects associated with: (1) formation of H2S from HS- by protonation in aqueous solution; and (2) volatilization of H2S have been experimentally determined. Both isotopic distributions in closed systems at equilibrium and differential rates of volatilization of isotopic species in open systems were measured at 22 +/- 1 degrees C. It was found that, at equilibrium aqueous H2S is enriched in 34S by 2.0 - 2.7% relative to HS- and that H2S volatilized from solution is depleted in 34S by 0.5% relative to dissolved H2S. A small kinetic isotope effect accompanying volatilization of H2S was observed in the open-system experiments.

  17. Characterization of anticancer, DNase and antifungal activity of pumpkin 2S albumin.

    PubMed

    Tomar, Prabhat Pratap Singh; Nikhil, Kumar; Singh, Anamika; Selvakumar, Purushotham; Roy, Partha; Sharma, Ashwani Kumar

    2014-06-13

    The plant 2S albumins exhibit a spectrum of biotechnologically exploitable functions. Among them, pumpkin 2S albumin has been shown to possess RNase and cell-free translational inhibitory activities. The present study investigated the anticancer, DNase and antifungal activities of pumpkin 2S albumin. The protein exhibited a strong anticancer activity toward breast cancer (MCF-7), ovarian teratocarcinoma (PA-1), prostate cancer (PC-3 and DU-145) and hepatocellular carcinoma (HepG2) cell lines. Acridine orange staining and DNA fragmentation studies indicated that cytotoxic effect of pumpkin 2S albumin is mediated through induction of apoptosis. Pumpkin 2S albumin showed DNase activity against both supercoiled and linear DNA and exerted antifungal activity against Fusarium oxysporum. Secondary structure analysis by CD showed that protein is highly stable up to 90°C and retains its alpha helical structure. These results demonstrated that pumpkin 2S albumin is a multifunctional protein with host of potential biotechnology applications.

  18. Selective expression of histamine receptors H1R, H2R, and H4R, but not H3R, in the human intestinal tract

    PubMed Central

    Sander, L E; Lorentz, A; Sellge, G; Coëffier, M; Neipp, M; Veres, T; Frieling, T; Meier, P N; Manns, M P; Bischoff, S C

    2006-01-01

    Background and aims Histamine is known as a regulator of gastrointestinal functions, such as gastric acid production, intestinal motility, and mucosal ion secretion. Most of this knowledge has been obtained from animal studies. In contrast, in humans, expression and distribution of histamine receptors (HR) within the human gastrointestinal tract are unclear. Methods We analysed HR expression in human gastrointestinal tissue specimens by quantitative reverse transcription‐polymerase chain reaction and immunostaining. Results We found that H1R, H2R, and H4R mRNA were expressed throughout the gastrointestinal tract, while H3R mRNA was absent. No significant differences in the distribution of HR were found between different anatomical sites (duodenum, ileum, colon, sigma, and rectum). Immunostaining of neurones and nerve fibres revealed that H3R was absent in the human enteric nervous system; however, H1R and H2R were found on ganglion cells of the myenteric plexus. Epithelial cells also expressed H1R, H2R and, to some extent, H4R. Intestinal fibroblasts exclusively expressed H1R while the muscular layers of human intestine stained positive for both H1R and H2R. Immune cells expressed mRNA and protein for H1R, H2R, and low levels of H4R. Analysis of endoscopic biopsies from patients with food allergy and irritable bowel syndrome revealed significantly elevated H1R and H2R mRNA levels compared with controls. Conclusions We have demonstrated that H1R, H2R and, to some extent, H4R, are expressed in the human gastrointestinal tract, while H3R is absent, and we found that HR expression was altered in patients with gastrointestinal diseases. PMID:16299042

  19. ACTN3 R577X Gene Variant is Associated with Muscle-related Phenotypes in elite Chinese Sprint/Power Athletes.

    PubMed

    Yang, Ruoyu; Shen, Xunzhang; Wang, Yubin; Voisin, Sarah; Cai, Guang; Fu, Yongnan; Xu, Wangyu; Eynon, Nir; Bishop, David J; Yan, Xu

    2016-07-16

    The ACTN3 R577X polymorphism (rs1815739) has been shown to influence athletic performance. The aim of the current study was to investigate the prevalence of this polymorphism in elite Chinese track and field athletes, and to explore its effects on athletes' level of competition and lower-extremity power. We compared the ACTN3 R577X genotypes and allele frequencies in 59 elite sprint/power athletes, 44 elite endurance athletes, and 50 healthy controls from Chinese Han origin. We then subcategorized the athletes into international-level and national-level, and investigated the effects of ACTN3 genotype on lower-extremity power. Genotype distribution of the sprint/power athletes was significantly different from endurance athletes (p = 0.001) and controls (p < 0.001). The frequency of the RR genotype was significantly higher in international-level than in the national-level sprint/power athletes (p = 0.004), with no international-level sprint/power athletes with XX genotype. The best standing long jump (SLJ) and standing vertical jump (SVJ) results of sprint/power athletes were better in the RR than the RX+XX genotypes (p = 0.004 and p = 0.001, respectively). In conclusion, the ACTN3 R577X polymorphism influences the level of competition and lower extremity power of elite Chinese S/P athletes. Including relevant phenotypes such as muscle performance in future studies is important to further understand the effects of gene variants on elite athletic performance.

  20. State-of-health monitoring of 18650 4S packs with a single-point impedance diagnostic

    NASA Astrophysics Data System (ADS)

    Love, Corey T.; Virji, Maheboob B. V.; Rocheleau, Richard E.; Swider-Lyons, Karen E.

    2014-11-01

    The state-of-health (SOH) of Li-ion batteries and battery packs must be monitored effectively for abuse to prevent failure and accidents. In a previous publication, we described a single-point impedance diagnostic method for detecting damage in single prismatic lithium polymer rechargeable cells subjected to overcharge abuse. We now determine whether the single-point impedance diagnostic method is applicable to 4S battery packs. At 316 Hz, commercial 18650 LiCoO2 cells are determined to have the least change in impedance response when cycled between 3.0 and 4.2 V, for states-of-charge (SOC) of 0-100%. The impedance response of single cells at 316 Hz changes dramatically during overcharge (SOC = 125%), presumably due to change in their solid electrolyte interface (SEI) layers at the electrodes. When a single cell is purposely subjected to such overcharge abuse and then integrated into a 4S pack with 3 other healthy cells, the impedance response of the 4S pack at 316 Hz also changes, despite variances in the impedance response of each of the 3 healthy cells. The results suggest that this single-point impedance method could serve as a diagnostic in an all-inclusive battery management system to identify overcharge abuse of single cells without individual cell monitoring.

  1. Characteristics of ferroelectric-ferroelastic domains in Néel-type skyrmion host GaV4S8

    NASA Astrophysics Data System (ADS)

    Butykai, Ádám; Bordács, Sándor; Kézsmárki, István; Tsurkan, Vladimir; Loidl, Alois; Döring, Jonathan; Neuber, Erik; Milde, Peter; Kehr, Susanne C.; Eng, Lukas M.

    2017-03-01

    GaV4S8 is a multiferroic semiconductor hosting Néel-type magnetic skyrmions dressed with electric polarization. At Ts = 42 K, the compound undergoes a structural phase transition of weakly first-order, from a non-centrosymmetric cubic phase at high temperatures to a polar rhombohedral structure at low temperatures. Below Ts, ferroelectric domains are formed with the electric polarization pointing along any of the four <111> axes. Although in this material the size and the shape of the ferroelectric-ferroelastic domains may act as important limiting factors in the formation of the Néel-type skyrmion lattice emerging below TC = 13 K, the characteristics of polar domains in GaV4S8 have not been studied yet. Here, we report on the inspection of the local-scale ferroelectric domain distribution in rhombohedral GaV4S8 using low-temperature piezoresponse force microscopy. We observed mechanically and electrically compatible lamellar domain patterns, where the lamellae are aligned parallel to the (100)-type planes with a typical spacing between 100 nm–1.2 μm. Since the magnetic pattern, imaged by atomic force microscopy using a magnetically coated tip, abruptly changes at the domain boundaries, we expect that the control of ferroelectric domain size in polar skyrmion hosts can be exploited for the spatial confinement and manipulation of Néel-type skyrmions.

  2. Isomerization and fragmentation of acetonitrile upon interaction with N(4S) atoms: the chemistry of nitrogen in dense molecular clouds

    NASA Astrophysics Data System (ADS)

    Mencos, Alejandro; Krim, Lahouari

    2016-08-01

    We experimentally show that the reaction between ground state nitrogen atoms N(4S) and acetonitrile CH3CN can lead to two distinct chemical pathways that are both thermally activated at very low temperatures. First is CH3CN isomerization which produces CH3NC and H2CCNH. Second is CH3CN decomposition which produces HNC and CH3CNH+CN- fragments, with the possible release of H2. Our results reveal that the mobility of N(4S)-atoms is stimulated in the 3-11 K temperature range, and that its subsequent encounter with one acetonitrile molecule is sufficient for the aforementioned reactions to occur without the need for additional energy to be supplied to the CH3CN + N(4S) system. These findings shed more light on the nitrogen chemistry that can possibly take place in dense molecular clouds, which until now was thought to only involve high-energy processes and therefore be unlikely to occur in such cold and dark interstellar regions. The reaction pathways we propose in this study have very important astrochemical implications, as it was shown recently that the atomic nitrogen might be more abundant, in many interstellar icy grain mantles, than previously thought. Also, these reaction pathways can now be considered within dense molecular clouds, and possibly affect the branching ratios for N-bearing molecules computed in astrochemical modelling.

  3. Molecular hybridization of iodinated 4S, 5S, and 18S + 28S RNA to salamander chromosomes

    PubMed Central

    1976-01-01

    4S, 5S, AND 18S + 28S RNA from the newt Taricha granulosa granulosa were iodinated in vitro with carrier-free 125I and hybridized to the denatured chromosomes of Taricha granulosa and Batrachoseps weighti. Iodinated 18S + 28S RNA hybridizes to the telomeric region on the shorter arm of chromosome 2 and close to the centromere on the shorter arm of chromosome 9 from T. granulosa. On this same salamander the label produced by the 5S RNA is located close to or on the centromere of chromosome 7 and the iodinated 4S RNA labels the distal end of the longer arm of chromosome 5. On the chromosomes of B. wrighti, 18S + 28S RNA hybridizes close to the centromeric region on the longer arm of the largest chromosome. Two centromeric sites are hybridized by the iodinated 5S RNA. After hybridization with iodinated 4S RNA, label is found near the end of the shorter arm of chromosome 3. It is concluded that both ribosomal and transfer RNA genes are clustered in the genome of these two salamanders. PMID:944187

  4. Characteristics of ferroelectric-ferroelastic domains in Néel-type skyrmion host GaV4S8

    PubMed Central

    Butykai, Ádám; Bordács, Sándor; Kézsmárki, István; Tsurkan, Vladimir; Loidl, Alois; Döring, Jonathan; Neuber, Erik; Milde, Peter; Kehr, Susanne C.; Eng, Lukas M.

    2017-01-01

    GaV4S8 is a multiferroic semiconductor hosting Néel-type magnetic skyrmions dressed with electric polarization. At Ts = 42 K, the compound undergoes a structural phase transition of weakly first-order, from a non-centrosymmetric cubic phase at high temperatures to a polar rhombohedral structure at low temperatures. Below Ts, ferroelectric domains are formed with the electric polarization pointing along any of the four 〈111〉 axes. Although in this material the size and the shape of the ferroelectric-ferroelastic domains may act as important limiting factors in the formation of the Néel-type skyrmion lattice emerging below TC = 13 K, the characteristics of polar domains in GaV4S8 have not been studied yet. Here, we report on the inspection of the local-scale ferroelectric domain distribution in rhombohedral GaV4S8 using low-temperature piezoresponse force microscopy. We observed mechanically and electrically compatible lamellar domain patterns, where the lamellae are aligned parallel to the (100)-type planes with a typical spacing between 100 nm–1.2 μm. Since the magnetic pattern, imaged by atomic force microscopy using a magnetically coated tip, abruptly changes at the domain boundaries, we expect that the control of ferroelectric domain size in polar skyrmion hosts can be exploited for the spatial confinement and manipulation of Néel-type skyrmions. PMID:28294193

  5. Au@Co0.4S core-shell nanoparticles: synthesis, characterization and evaluation of photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Warjri, Wandibahun; Negi, Devendra P. S.

    2016-09-01

    In the present work, Au@Co0.4S core-shell nanoparticles were synthesized and characterized by energy-dispersive x-ray spectroscopy, transmission electron microscopy, selected area electron diffraction and diffuse reflectance spectroscopy. The photocatalytic activity of the as-prepared core-shell nanoparticles was evaluated by studying the degradation of methyl orange (MO) spectrophotometerically under visible light irradiation. Under optimum experimental conditions, 68.9% of the dye was degraded during 50 min of irradiation. Control experiments showed negligible degradation of MO in the absence of the photocatalyst under visible light irradiation. A good correlation was obtained between the concentration of the dye adsorbed on the surface of the Au@Co0.4S core-shell nanoparticles and its degradation efficiency. The as-prepared nanoparticles showed good recyclability for the degradation of MO. The mechanistic studies suggested that the valence band holes of the Co0.4S nanoparticles were scavenged by the MO molecules resulting in the degradation of the dye.

  6. Study of Y(3S, 2S)-> eta Y(1S) and Y(3S, 2S) -> pi pi- Y(1S) Hadronic Transitions

    SciTech Connect

    Lees, J.P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D.A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D.J.; Hearty, C.; Mattison, T.S.; McKenna, J.A.; /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison

    2012-03-27

    We study the {Upsilon}(3S, 2S) {yields} {eta}{Upsilon}(1S) and {Upsilon}(3S, 2S) {yields} {pi}{sup +}{pi}{sup -}{Upsilon}(1S) transitions with 122 x 10{sup 6} {Upsilon}(3S) and 100 x 10{sup 6} {Upsilon}(2S) mesons collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider. We measure {Beta}[{Upsilon}(2S) {yields} {eta}{Upsilon}(1S)] = (2.39 {+-} 0.31(stat.) {+-} 0.14(syst.)) x 10{sup -4} and {Lambda}[{Upsilon}(2S) {yields} {eta}{Upsilon}(1S)]/{Lambda}[{Upsilon}(2S) {yields} {pi}{sup +}{pi}{sup -}{Upsilon}(1S)] = (1.35 {+-} 0.17(stat.) {+-} 0.08(syst.)) x 10{sup -3}. We find no evidence for {Upsilon}(3S) {yields} {eta}{Upsilon}(1S) and obtain {Beta}[{Upsilon}(3S) {yields} {eta}{Upsilon}(1S)] < 1.0 x 10{sup -4} and {Lambda}[{Upsilon}(3S) {yields} {eta}{Upsilon}(1S)]/{Lambda}[{Upsilon}(3S) {yields} {pi}{sup +}{pi}{sup -}{Upsilon}(1S)] < 2.3 x 10{sup -3} as upper limits at the 90% confidence level. We also provide improved measurements of the {Upsilon}(2S)-{Upsilon}(1S) and {Upsilon}(3S)-{Upsilon}(1S) mass differences, 562.170 {+-} 0.007(stat.) {+-} 0.088(syst.)MeV/c{sup 2} and 893.813 {+-} 0.015(stat.) {+-} 0.107(syst.)MeV/c{sup 2}, respectively.

  7. Formation and characterization of an all-ferrous Rieske cluster and stabilization of the [2Fe-2S]0 core by protonation.

    PubMed

    Leggate, Ellen J; Bill, Eckhard; Essigke, Timm; Ullmann, G Matthias; Hirst, Judy

    2004-07-27

    The all-ferrous Rieske cluster, [2Fe-2S](0), has been produced in solution and characterized by protein-film voltammetry and UV-visible, EPR, and Mössbauer spectroscopies. The [2Fe-2S](0) cluster, in the overexpressed soluble domain of the Rieske protein from the bovine cytochrome bc(1) complex, is formed at -0.73 V at pH 7. Therefore, at pH 7, the [2Fe-2S](1+/0) couple is 1.0 V below the [2Fe-2S](2+/1+) couple. The two cluster-bound ferrous irons are both high spin (S = 2), and they are coupled antiferromagnetically (-J > or = 30 cm(-1), H =-2JS1.S2) to give a diamagnetic (S = 0) ground state. The ability of the Rieske cluster to exist in three oxidation states (2+, 1+, and 0) without an accompanying coupled reaction, such as a conformational change or protonation, is highly unusual. However, uncoupled reduction to the [2Fe-2S](0) state occurs at pH > 9.8 only, and at high pH the intact cluster persists in solution for <1 min. At pH < 9.8, the all-ferrous cluster is stabilized significantly by protonation. A combination of experimental data and calculations based on density functional theory suggests strongly that the proton binds to one of the cluster mu(2)-sulfides, consistent with observations that reduced [3Fe-4S] clusters are protonated also. The implications for our understanding of coupled reactions at iron-sulfur clusters and of the factors that determine the relative stabilities of their different oxidation states are discussed.

  8. The geochemistry and sequestration of H 2S into the geothermal system at Hellisheidi, Iceland

    NASA Astrophysics Data System (ADS)

    Stefánsson, Andri; Arnórsson, Stefán; Gunnarsson, Ingvi; Kaasalainen, Hanna; Gunnlaugsson, Einar

    2011-05-01

    The geochemistry and mineralization of H 2S in the geothermal system hosted by basaltic rock formation at Hellisheidi, SW Iceland, was studied. Injection of mixtures of H 2S with geothermal waste water and condensed steam into the > 230 °C geothermal aquifer is planned, where H 2S will hopefully be removed in the form of sulphides. The natural H 2S concentrations in the aquifer average 130 ppm. They are considered to be controlled by close approach to equilibrium with pyrite, pyrrhotite, prehnite and epidote. Injection of H 2S will increase significantly the reservoir H 2S equilibrium concentrations, resulting in mineralization of pyrite and possibly other sulphides as well as affecting the formation of prehnite and epidote. Based on reaction path modelling, the main factors affecting the H 2S mineralization capacity are related to the mobility and oxidation state of iron. At temperatures above 250 °C the pyrite mineralization is greatly reduced upon epidote formation leading to the much greater basalt dissolution needed to sequestrate the H 2S. Based on these findings, the optimum conditions for H 2S injection are aquifers with temperatures below ~ 250 °C where epidote formation is insignificant. Moreover, the results suggest that sequestration of H 2S into the geothermal system is feasible. The total flux of H 2S from the Hellisheidi power plant is 12,950 tonnes yr - 1 . Injection into 250 °C aquifers would result in dissolution of ~ 1000 tonnes yr - 1 of basalt for mineralization of H 2S as pyrite, corresponding to ~ 320 m 3 yr - 1 .

  9. SDS-assisted hydrothermal synthesis of porous CdIn2S4 microspheres

    NASA Astrophysics Data System (ADS)

    Bai, X. F.; Li, J. S.; Wu, W.

    2017-02-01

    The porous CdIn2S4 microspheres were synthesized via a sodium dodecyl sulfate (SDS)-assisted hydrothermal technology. The as-prepared CdIn2S4 products were characterized by X-ray diffraction, field emission scanning electron microscopy and UV-Vis diffusive reflectance spectroscopy. The results showed that hydrothermal time and the surfactant addition had great effect on the structure, morphology and optical property of CdIn2S4 products.

  10. Esterase Activated Carbonyl Sulfide/Hydrogen Sulfide (H2S) Donors.

    PubMed

    Chauhan, Preeti; Bora, Prerona; Ravikumar, Govindan; Jos, Swetha; Chakrapani, Harinath

    2017-01-06

    Hydrogen sulfide (H2S) is a mediator of a number of cellular processes, and modulating cellular levels of this gas has emerged as an important therapeutic area. Localized generation of H2S is thus very useful but highly challenging. Here, we report pivaloyloxymethyl-based carbonothioates and carbamothioates that are activated by the enzyme, esterase, to generate carbonyl sulfide (COS), which is hydrolyzed to H2S.

  11. Controlling stereoselectivity by enzymatic and chemical means to access enantiomerically pure (1S,3R)-1-benzyl-2,3-dimethyl-1,2,3,4-tetrahydroisoquinoline derivatives☆

    PubMed Central

    Orden, Alejandro A.; Schrittwieser, Joerg H.; Resch, Verena; Mutti, Francesco G.; Kroutil, Wolfgang

    2013-01-01

    A chemoenzymatic strategy for the synthesis of enantiomerically pure novel alkaloids (1S,3R)-1-benzyl-2,3-dimethyl-1,2,3,4-tetrahydroisoquinolines is presented. The key steps are the biocatalytic stereoselective reductive amination of substituted 1-phenylpropan-2-one derivatives to yield chiral amines employing microbial ω-transaminases, and the diastereoselective reduction of a Bischler–Napieralski imine intermediate by catalytic hydrogenation in the presence of palladium on charcoal, leading exclusively to the desired cis-isomer. PMID:24503964

  12. Magnetic phase transitions in two-dimensional frustrated Cu3R(SeO3)2O2Cl. Spectroscopic study

    NASA Astrophysics Data System (ADS)

    Klimin, S. A.; Budkin, I. V.

    2016-12-01

    Using optical study of electronic spectra of rare-earth (RE) ions, magnetic phase transitions in the low-dimensional frustrated RE magnets Cu3R(SeO3)2O2Cl (R = Sm, Yb, Er, Nd, Pr, Eu) were investigated. Phase transitions were registered either by splittings of crystal-field (CF) doublets or by repulsion of CF levels of f-ions in a staggered magnetic field. Different scenarios of magnetic order in isostructural compounds of the francisite family are discussed.

  13. Phase and structural behavior of SmAlO{sub 3}–RAlO{sub 3} (R = Eu, Gd) systems

    SciTech Connect

    Ohon, N.; Vasylechko, L.; Prots, Yu.; Schmidt, M.

    2014-02-01

    Highlights: • Continuous solid solutions exist in the SmAlO{sub 3}–RAlO{sub 3} (R = Eu, Gd) systems. • Lattice parameter crossover was found in solid solutions Sm{sub 1−x}R{sub x}AlO{sub 3} (R = Eu, Gd). • Thermally induced lattice crossovers occur in Sm{sub 0.9}R{sub 0.1}AlO{sub 3} at elevated temperatures. • First-order structural phase transition Pbnm↔R3{sup ¯}c was found in Sm{sub 1−x}R{sub x}AlO{sub 3} (R = Eu, Gd). • Phase diagram of the systems SmAlO{sub 3}–EuAlO{sub 3} and SmAlO{sub 3}–GdAlO{sub 3} has been constructed. - Abstract: Phase and structural behavior in the SmAlO{sub 3}–RAlO{sub 3} (R = Eu, Gd) systems has been studied in a whole concentration range by means of laboratory X-ray diffraction, in situ synchrotron powder diffraction and differential thermal analysis techniques. Continuous solid solutions with orthorhombic perovskite structure have been found in both systems. Peculiarity of the solid solutions of Sm{sub 1−x}Eu{sub x}AlO{sub 3} and Sm{sub 1−x}Gd{sub x}AlO{sub 3} is the existence of two lattice parameter crossovers in each system occurred at x{sub Eu} = 0.07 and 0.62 and at x{sub Gd} = 0.04 and 0.33, respectively. The temperature induced lattice crossovers in the Sm{sub 0.9}Eu{sub 0.1}AlO{sub 3} and Sm{sub 0.9}Gd{sub 0.1}AlO{sub 3} samples have been found at 387 and 922 K and at 501 and 894 K. First-order reversible structural phase transformations Pbnm↔R3{sup ¯}c have been detected in both systems at the elevated temperatures. The temperatures of these transitions increase linearly with the decreasing of the samarium content. Phase diagrams of the pseudo-binary systems SmAlO{sub 3}–EuAlO{sub 3} and SmAlO{sub 3}–GdAlO{sub 3} have been constructed.