967 resultados para gamma-delta


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Luminescent films containing terbium complex [Tb(acac)(3)(H(2)O)(3)] (acac = acetylacetonate) doped into a polycarbonate (PC) matrix were prepared and irradiated at low-dose gamma radiation with ratio of 5 and 10 kGy. The PC polymer was doped with 5% (w/w) of the Tb(3+) complex. The thermal behavior was investigated by utilization of differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). Changes in thermal stability due to the addition of doping agent into the polycarbonate matrix. Based on the emission spectra of PC:5% Tb(acac)(3) film were observed the characteristic bands arising from the (5)D(4) -> (7)F(J) transitions of Tb(3+) ion (J = 0-6), indicating the ability to obtain the luminescent films. Doped samples irradiated at low dose of gamma irradiation showed a decrease in luminescence intensity with increasing of the dose. (C) 2009 Elsevier Ltd. All rights reserved.

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Enantiomerically pure (R)- and (S)-gamma-hydroxy-organochalcogenides are prepared using poly-[R]-3-hydroxybutanoate (PHB) as the starting material. (C) 2009 Elsevier Ltd. All rights reserved.

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A C-O-dianionic zincate was generated by a Te/Li exchange reaction of an alkyltelluride, followed by Li/Zn transmetallation and reaction with methyllithium. The reaction between the enantiomerically pure (99% ee) (R)-dianionic zincate and benzoyl chloride led to 3-hydroxy-1-phenyl pentanone with total retention of the carbon configuration (99% ee). Similar results were obtained using the corresponding Lipshutz cyanocuprates. (C) 2009 Elsevier Ltd. All rights reserved.

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The electronic structure and chemical bonding of the ground and low-lying Lambda - S and Omega states of Ta(2) were investigated at the multiconfiguration second-order perturbation theory (CASSCF//CASPT2) level. The ground state of Ta(2) is computed to be a X(3)Sigma(-)(g) state (R(e) = 2.120 angstrom, omega(e) = 323 cm(-1), and D(e) = 4.65 eV), with two low-lying singlet states close to it (a(1) Sigma(+)(g) : T(e) = 409 cm(-1), R(e) = 2.131 angstrom, and omega(e) = 313 cm(-1); b(1) Gamma(g): T(e) = 1, 038 cm(-1), R(e) = 2.127 angstrom, and omega(e) = 316 cm(-1)). These electronic states are derived from the same electronic configuration: vertical bar 13 sigma(2)(g)14 sigma(2)(g)7 delta(2)(g)13 pi(4)(u)>. The effective bond order of the X(3) Sigma(-)(g) state is 4.52, which indicates that the Ta atoms are bound by a quintuple chemical bond. The a(1) Sigma(+)(g) state interacts strongly with the X(3)Sigma(-)(g) g ground state by a second-order spin-orbit interaction, giving rise to the (1)0(g)(+) (ground state) (dominated by the X(3)Sigma(-)(g) Lambda - S ground state) and (9)0(g)(+) (dominated by the a(1) Sigma(+)(g) Lambda - S state) Omega states. These results are in line with those reported for the group 5B homonuclear transition metal diatomics. (C) 2010 Wiley Periodicals, Inc. Int J Quantum Chem 111: 1306-1315, 2011

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A new approach for the synthesis of alpha,beta-unsaturated delta-lactones, a unit present in many natural products with interesting biological activities is described. The approach was based on the use of a vinyl telluride, and it is complementary to the methods using ring-closing metathesis. The sequence was performed in good overall yield with retention of the Z-double bond geometry. (C) 2011 Elsevier Ltd. All rights reserved.

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The total synthesis of (-)-Blastmycinolactol, (+)-Blastmycinone, (-)-NFX-2, and (+)-Antimycinone was accomplished in few steps in high yields and ee, starting from enantiomerically enriched (S)-Z-vinylic hydroxytellurides. (C) 2010 Published by Elsevier Ltd.

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The prion protein (PrP(C)) is highly expressed in the nervous system, and its abnormal conformer is associated with prion diseases. PrP(C) is anchored to cell membranes by glycosylphosphatidylinositol, and transmembrane proteins are likely required for PrP(C)-mediated intracellular signaling. Binding of laminin (Ln) to PrP(C) modulates neuronal plasticity and memory. We addressed signaling pathways triggered by PrP(C)-Ln interaction in order to identify transmembrane proteins involved in the transduction of PrP(C)-Ln signals. The Ln gamma 1-chain peptide, which contains the Ln binding site for PrP(C), induced neuritogenesis through activation of phospholipase C (PLC), Ca(2+) mobilization from intracellular stores, and protein kinase C and extracellular signal-regulated kinase (ERK1/2) activation in primary cultures of neurons from wild-type, but not PrP(C)-null mice. Phage display, coimmunoprecipitation, and colocalization experiments showed that group I metabotropic glutamate receptors (mGluR1/5) associate with PrP(C). Expression of either mGluR1 or mGluR5 in HEK293 cells reconstituted the signaling pathways mediated by PrP(C)-Ln gamma 1 peptide interaction. Specific inhibitors of these receptors impaired PrP(C)-Ln gamma 1 peptide-induced signaling and neuritogenesis. These data show that group I mGluRs are involved in the transduction of cellular signals triggered by PrP(C)-Ln, and they support the notion that PrP(C) participates in the assembly of multiprotein complexes with physiological functions on neurons.-Beraldo, F. H., Arantes, C. P., Santos, T. G., Machado, C. F., Roffe, M., Hajj, G. N., Lee, K. S., Magalhaes, A. C., Caetano, F. A., Mancini, G. L., Lopes, M. H., Americo, T. A., Magdesian, M. H., Ferguson, S. S. G., Linden, R., Prado, M. A. M., Martins, V. R. Metabotropic glutamate receptors trans-duce signals for neurite outgrowth after binding of the prion protein to laminin gamma 1 chain. FASEB J. 25, 265-279 (2011). www.fasebj.org

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Cobalt catalysts were prepared on supports of SiO(2) and gamma-Al(2)O(3) by the impregnation method, using a solution of Co precursor in methanol. The samples were characterized by XRD, TPR, and Raman spectroscopy and tested in ethanol steam reforming. According to the XRD results, impregnation with the methanolic solution led to smaller metal crystallites than with aqueous solution, on the SiO(2) support. On gamma-Al(2)O(3), all the samples exhibited small crystallites, with either solvent, due to a higher Co-support interaction that inhibits the reduction of Co species. The TPR results were consistent with XRD results and the samples supported on gamma-Al(2)O(3) showed a lower degree of reduction. In the steam reforming of ethanol, catalysts supported on SiO(2) and prepared with the methanolic solution showed the best H(2), CO(2) and CO selectivity. Those supported on gamma-Al(2)O(3) showed lower H(2) selectivity. (C) 2011 Elsevier Ltd. All rights reserved.

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Alachlor has been widely used in agriculture all over the world. It is suggested that it may be a carcinogen and an environmental estrogen. The aim of this work was to verify the degradation the alachlor by gamma radiation. Gamma radiation from (60)Co was used to degrade the alachlor herbicide in water and methanol solution. The alachlor in water and alcohol solution in the concentration of 100 mgL(-1) was irradiated with doses of 0.25-50 kGy, at dose rate 5-6 and 2.7 kGyh(-1). High performance liquid chromatography was used as an analytical technique to determine the degradation rate of herbicide studied.

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Denna uppsats behandlar elever med lågt deltagande i ämnet Idrott och hälsa. Tio elever på två gymnasieskolor har intervjuats om varför de har låg närvaro vid idrottslektionerna. Syftet med arbetet är att undersöka vad i ämnet Idrott och hälsa som gör att vissa elever väljer att inte delta. Fokus ligger på vilka skäl eleverna anger för att inte delta, samt hur dessa elever skulle vilja förändra undervisningen i Idrott och hälsa för att deras deltagande ska öka. Resultatet pekar på att de skäl eleverna anger för läraren inte alltid stämmer överens med de faktiska skäl som eleverna har. Anledningarna till att eleverna inte vill vara med varierar, men i stora drag handlar det om att eleverna tycker att de traditionella föreningsidrotterna och tävlingsmomenten tar för stor plats. När det gäller förändringar så är det mest frekventa att eleverna vill vara mer delaktiga i att forma sin egen undervisning. De vill också se att de traditionella boll- och lagsporterna får stå tillbaka för fler alternativ i undervisningen. Om företrädarna för ämnet Idrott och hälsa i större utsträckning vill nå alla elever bör ämnet förändras. Kanske behöver ämnets popularitet sättas på spel och ämnets fokus flyttas längre bort från den traditionella föreningsidrotten än vad som idag är fallet.

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Stora idrottsevenemang är till stor del beroende av de intäkter som kommer från sponsrandeföretag. Inför skid-VM i Falun 2015 startade organisationen Beyond Skiing Foundation ABett projekt i form av ett sponsornätverk. Projektet kom att kallas Beyond Skiing och syftet varatt försöka locka regionala- företag, kommuner och organisationer att sponsra skid-VM.Tanken med sponsornätverket var att ge ett värde till projektets medlemmar som ville varamed och sponsra skid-VM, men som inte ville betala den summa pengar som krävdes för attbli huvudsponsorer till evenemanget.Syftet med denna undersökning är att förklara varför en heterogen grupp sponsorer utspriddaöver en stor region ingick i ett regionalt sponsornätverk. Urvalet bestod av medlemmarna iBeyond Skiing. Vidare gjordes ett urval att medlemmarna skulle vara lokaliserade i Dalarna,men utanför Falun. Anledningen till varför regionala sponsorer utan direkt geografiskkoppling till Falun valdes, var att kopplingen mellan deras sponsring av skid-VM kan påförhand ses som mer komplex och onaturlig jämfört med sponsorer från Falun, eftersomsponsring i mindre skala tenderar att röra samarbeten med sponsrade enheter inom samma ort.Data till studien samlades in genom fem kvalitativa telefonintervjuer. Resultatet indikerar påatt medlemmarna i Beyond Skiing hade tydliga kommersiella mål med sin sponsring av skid-VM och att sponsra endast genom goodwill var i detta fall mindre förekommande. Studien harvisat att sponsringssamarbetes specifika erbjudanden och regionala motiv har varit tvåbidragande orsaker till varför sponsorerna ville sponsra skid-VM. Särskilt nöjda varsponsorerna med nätverksträffarna som Beyond Skiing Foundation anordnade förmedlemmarna inom Beyond Skiing.

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I denna kvalitativa studie har enkäter insamlats från barn och unga som deltagit i stödgruppsverksamhet för barn och unga med en avliden nära anhörig i Dalarnas län. Syftet med studien har varit att beskriva deltagarnas erfarenheter av stödgrupperna. Genom kvalitativ innehållsanalys har tre kategorier identifierats; bearbetning, gemenskap och strukturens betydelse. Studien visar främst på betydelsen av att få träffa andra barn och unga i liknande situation samt indikerar till att deltagarnas KASAM (känsla av sammanhang) förhöjts genom deltagandet i stödgruppen.

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