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Sample records for f4 f5 f6

  1. Lesiones macro y microscópicas de intestino delgado de cerdos neonatos sin calostrar inoculados experimentalmente con cepas de E. coli fimbriadas Histopatholocial lesions in the small intestine of calostrum deprived pigs inoculated with strains of E. Coli bearing F4, F5, F6 y F41 fimbriaes

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    A.M CANAL

    1999-01-01

    Full Text Available La presente investigación se realizó con el propósito de evaluar los efectos patológicos de cepas enteropatógenas de E. coli que expresan antígenos fimbriales F4, F5, F6 y F41, administradas oralmente a cerdos neonatos que no ingirieron calostro. Los cerdos inoculados experimentalmente con las cuatro cepas enteropatógenas de E. coli presentaron diarrea acuosa y de color amarilla a las 4 h.p.i. Las lesiones macroscópicas se caracterizaron por congestión y abundante contenido acuoso, apreciándose diferencias solo en la intensidad lesional entre los diferentes grupos inoculados. Microscópicamente, el íleon fue el segmento más afectado, observándose congestión, adherencia bacteriana, vacuolización epitelial de las vellosidades intestinales, atrofia, infiltrados de neutrófilos y necrosis linfoide en placas de Peyer, siendo la cepa E. coli F4 responsable de las lesiones de mayor severidad. Los resultados de la presente investigación confirman la importancia de los antígenos fimbriales como factor de adhesión de cepas enteropatógenas de E. coli al intestino delgado de cerdos lactantes y permite proyectar a futuro metodologías que utilicen las propiedades antigénicas de las fimbrias no solo como métodos de diagnóstico sino también en la elaboración de inmunógenos los cuales evitarían la adhesión bacteriana y la presentación de cuadros de colibacilosis, enfermedad responsable de cuantiosas pérdidas económicas en la explotación porcina en la actualidadA study to evaluate the degrees of lesions caused by different enteropathogenic strains of E. coli was carried out. Newborn piglets without calostrum were innoculated with enteropathogenic strains of E. coli which contained F4, F5, F6 and F41 fimbriae in order to characterize the macro and microscopic lesions to the duodenum, jejunum and ilium. The pigs experimentally innoculated with the four enteropathegenic strains of E. coli presented watery, yellowish diarrhea four

  2. Syntheses of [F5TeNH3][AsF6], [F5TeN(H)Xe][AsF6], and F5TeNF2 and characterization by multi-NMR and Raman spectroscopy and by electronic structure calculations: the X-ray crystal structures of alpha- and beta-F5TeNH2, [F5TeNH3][AsF6], and [F5TeN(H)Xe][AsF6].

    Science.gov (United States)

    Fir, Barbara; Whalen, J Marc; Mercier, Hélène P A; Dixon, David A; Schrobilgen, Gary J

    2006-03-06

    The salt, [F5TeN(H)Xe][AsF6], has been synthesized in the natural abundance and 99.5% 15N-enriched forms. The F5TeN(H)Xe+ cation has been obtained as the product of the reactions of [F5TeNH3][AsF6] with XeF2 (HF and BrF5 solvents) and F5TeNH2 with [XeF][AsF6] (HF solvent) and characterized in solution by 129Xe, 19F, 125Te, 1H, and 15N NMR spectroscopy at -60 to -30 degrees C. The orange [F5TeN(H)Xe][AsF6] and colorless [F5TeNH3][AsF6] salts were crystallized as a mixture from HF solvent at -35 degrees C and were characterized by Raman spectroscopy at -165 degrees C and by X-ray crystallography. The crystal structure of the low-temperature phase, alpha-F5TeNH2, was obtained by crystallization from liquid SO2 between -50 and -70 degrees C and is fully ordered. The high-temperature phase, beta-F5TeNH2, was obtained by sublimation at room temperature and exhibits a 6-fold disorder. Decomposition of [F5TeN(H)Xe][AsF6] in the solid state was rapid above -30 degrees C. The decomposition of F5TeN(H)Xe+ in HF and BrF5 solution at -33 degrees C proceeded by fluorination at nitrogen to give F5TeNF2 and Xe gas. Electronic structure calculations at the Hartree-Fock and local density-functional theory levels were used to calculate the gas-phase geometries, charges, Mayer bond orders, and Mayer valencies of F5TeNH2, F5TeNH3+, F5TeN(H)Xe+, [F5TeN(H)Xe][AsF6], F5TeNF2, and F5TeN2- and to assign their experimental vibrational frequencies. The F5TeN(H)Xe+ and the ion pair, [F5TeN(H)Xe][AsF6], systems were also calculated at the MP2 and gradient-corrected (B3LYP) levels.

  3. Facile Routes to NiF(6)(2)(-), AgF(4)(-), AuF(6)(-), and PtF(6)(-) Salts Using O(2)(+) as a Source of O(2)F in Anhydrous HF.

    Science.gov (United States)

    Lucier, G. M.; Shen, C.; Elder, S. H.; Bartlett, N.

    1998-07-27

    O(2)(+) salts dissolved in liquid anhydrous hydrogen fluoride (aHF) at 20 degrees C or below oxidize aHF solutions of PtF(6)(2)(-) to PtF(6)(-). The parent base of O(2)(+) salts in aHF (O(2)F((solv))) generated with alkali fluoride is long-lived below -50 degrees C. An aHF solution of O(2)F((solv)) oxidizes Au(III) to Au(V) below -50 degrees C (2O(2)F((solv)) + AuF(4)(-)((solv)) --> AuF(6)(-)((solv)) +2O(2(g))). In situ generation of O(2)F((solv)) (O(2)(+)((solv)) + F(-)((solv)) --> O(2)F((solv))) with AgF(2) or NiF(2) in suspension in the aHF made basic with alkali fluoride gives AgF(4)(-) and NiF(6)(2)(-)salts. Low solubility of AAsF(6)(A = Cs, K) in aHF provides for the metathetical preparation of (O(2))(2)PdF(6) solutions in aHF. Removal of aHF, even at -60 degrees C, results in some O(2) and F(2) loss, to a composition approaching (O(2))PdF(5).

  4. Solid-state and solution rearrangements of F3S[triple bond]NXeF+ leading to the F4S=NXe+ cation; syntheses, HF solvolyses, and structural characterizations of [F4S=NXe][AsF6] and[F4S=NH2][AsF6].

    Science.gov (United States)

    Smith, Gregory L; Mercier, Hélène P A; Schrobilgen, Gary J

    2009-06-03

    The salt, [F(4)S=NXe][AsF(6)], has been synthesized by the solid-state rearrangement of [F(3)S[triple bond]NXeF][AsF(6)] and by HF-catalyzed rearrangement of [F(3)S[triple bond]NXeF][AsF(6)] in anhydrous HF (aHF) and HF/BrF(5) solvents. The F(4)S=NXe(+) cation undergoes HF solvolysis to form F(4)S=NH(2)(+), XeF(2), and the recently reported F(5)SN(H)Xe(+) cation. Both [F(4)S=NXe][AsF(6)] and [F(4)S=NH(2)][AsF(6)] have been characterized by (129)Xe and (19)F NMR spectroscopy in aHF and HF/BrF(5) solvents and by single-crystal X-ray diffraction. The [F(4)S=NXe][AsF(6)] salt was also characterized by Raman spectroscopy. The Xe-N bond of F(4)S=NXe(+) is among the shortest Xe-N bonds presently known (2.084(3) A), and the cation interacts with the AsF(6)(-) anion by means of a Xe---F-As bridge in which the Xe---F distance (2.618(2) A) is significantly less than the sum of the Xe and F van der Waals radii. Both F(4)S=NXe(+) and F(4)S=NH(2)(+) exhibit trigonal bipyramidal geometries about sulfur, with nitrogen in the equatorial plane and the nitrogen substituents coplanar with the axial fluorine ligands of sulfur. The F(4)S=NH(2)(+) cation is isoelectronic with F(4)S=CH(2) and, like F(4)S=CH(2), has a high barrier to rotation about the S=N double bond and to pseudorotation of the trigonal bipyramidal F(4)S=N- moiety. The solution and solid-state rearrangements of F(3)S[triple bond]NXeF(+) to F(4)S=NXe(+) are proposed to result from attack at sulfur by fluoride ion arising from HF in solution and from the AsF(6)(-) anion in the solid state. Quantum-chemical calculations were employed to calculate the gas-phase geometries, charges, bond orders, valencies, and vibrational frequencies of F(4)S=NXe(+) and F(4)S=NH(2)(+). The F(4)S=NXe(+) cation provides the first example of xenon bonded to an imido-nitrogen, and together with the F(4)S=NH(2)(+) cation are presently the only cations known to contain the F(4)S=N-group. Both cations are intermediates in the HF solvolysis pathways

  5. Clostridium botulinum strains producing BoNT/F4 or BoNT/F5.

    Science.gov (United States)

    Raphael, Brian H; Bradshaw, Marite; Kalb, Suzanne R; Joseph, Lavin A; Lúquez, Carolina; Barr, John R; Johnson, Eric A; Maslanka, Susan E

    2014-05-01

    Botulinum neurotoxin type F (BoNT/F) may be produced by Clostridium botulinum alone or in combination with another toxin type such as BoNT/A or BoNT/B. Type F neurotoxin gene sequences have been further classified into seven toxin subtypes. Recently, the genome sequence of one strain of C. botulinum (Af84) was shown to contain three neurotoxin genes (bont/F4, bont/F5, and bont/A2). In this study, eight strains containing bont/F4 and seven strains containing bont/F5 were examined. Culture supernatants produced by these strains were incubated with BoNT/F-specific peptide substrates. Cleavage products of these peptides were subjected to mass spectral analysis, allowing detection of the BoNT/F subtypes present in the culture supernatants. PCR analysis demonstrated that a plasmid-specific marker (PL-6) was observed only among strains containing bont/F5. Among these strains, Southern hybridization revealed the presence of an approximately 242-kb plasmid harboring bont/F5. Genome sequencing of four of these strains revealed that the genomic backgrounds of strains harboring either bont/F4 or bont/F5 are diverse. None of the strains analyzed in this study were shown to produce BoNT/F4 and BoNT/F5 simultaneously, suggesting that strain Af84 is unusual. Finally, these data support a role for the mobility of a bont/F5-carrying plasmid among strains of diverse genomic backgrounds.

  6. New effective coupled $F(^{(4)}\\!R,\\varphi)$ modified gravity from $f(^{(5)}\\!R)$ gravity in five dimensions

    CERN Document Server

    Aguilar, Jose Edgar Madriz

    2015-01-01

    We obtain a new kind of $F(^{(4)}\\!R,\\varphi)$ modified gravity theory as an effective four-dimensional (4D) theory derived from $f(^{(5)}\\!R)$ gravity in five dimensions (5D). This new theory exhibits a different matter coupling than the one in BBHL theory. We show that the field equations of the Wesson's induced matter theory and of some braneworld scenarios can be obtained as maximally symmetric solutions of the $f(^{(5)}\\!R)$ theory. We found criteria for the Goldov-Kawasaki instabilities for both the $f(^{(5)}\\!R)$ and the $F(^{(4)}\\!R,\\varphi)$ theories. We demonstrate that under certain conditions imposed on the 5D geometry it is possible to interpret the $F(^{(4)}\\!R,\\varphi)$ theory as a modified gravity theory with dynamical coefficients, making this new theory a viable candidate to address the present accelerating cosmic expansion issue.

  7. Inheritance of spike length in F3, F4 and F5 wheat hybrids obtained by different selection methods

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    Janković Snežana

    2012-01-01

    Full Text Available This study analyses the mode of inheritance of spike length in F3, F4 and F5 wheat hybrids obtained by pedigree, bulk and modified pedigree method of selection. Wheat hybrids were produced after crossing five varieties by M x N method. Three varieties were used as a female parent (Briscard, Carifen 12 and Rescler and two as a male component (Francuska and PKB-Prelivka. Descendents in F2 generation were produced from 6 F1 hybrids (3 x 2. Selection after F2 generation were undertaken from 1996 to 1999, while in 2000 the field experiments with complete breeding material were set up at the Institute 'PKB INI Agroekonomik' in Padinska Skela near Belgrade. Spike length was measured in progeny generations, from F3 to F5. It was observed that progenies had higher values for spike length than better parent (BP, with longer spikes in 5 out of 6 analyzed hybrids: Briscard x PKB-Prelivka, Carifen 12 x Francuska, Carifen 12 x PKB-Prelivka, Rescler x Francuska, and Rescler x PKB-Prelivka. From the above mentioned hybrid combinations, only Rescler x Francuska descendents in F5 generation obtained by pedigree and bulk selection inherited the spike length from the parent with lower value. High significant interaction was observed for spike length between genotype and generation of progenies in each of the applied selection methods.

  8. Hydrogen for fluorine exchange in C6F6 and C6F5H by monomeric [1,3,4-(Me3C)3C5H2]2CeH: experimental and computational studies.

    Science.gov (United States)

    Maron, Laurent; Werkema, Evan L; Perrin, Lionel; Eisenstein, Odile; Andersen, Richard A

    2005-01-12

    The net reaction of monomeric Cp'(2)CeH [Cp' = 1,3,4-(Me(3)C)(3)(C(5)H(2))] in C(6)D(6) with C(6)F(6) is Cp'(2)CeF, H(2), and tetrafluorobenzyne. The pentafluorophenylmetallocene, Cp'(2)Ce(C(6)F(5)), is formed as an intermediate that decomposes slowly to Cp'(2)CeF and C(6)F(4) (tetrafluorobenzyne), and the latter is trapped by the solvent C(6)D(6) as a [2+4] cycloadduct. In C(6)F(5)H, the final products are also Cp'(2)CeF and H(2), which are formed from the intermediates Cp'(2)Ce(C(6)F(5)) and Cp'(2)Ce(2,3,5,6-C(6)F(4)H) and from an unidentified metallocene of cerium and the [2+4] cycloadducts of tetra- and trifluorobenzyne with C(6)D(6). The hydride, fluoride, and pentafluorophenylmetallocenes are isolated and characterized by X-ray crystallography. DFT(B3PW91) calculations have been used to explore the pathways leading to the observed products of the exergonic reactions. A key step is a H/F exchange reaction which transforms C(6)F(6) and the cerium hydride into C(6)F(5)H and Cp'(2)CeF. This reaction starts by an eta(1)-F-C(6)F(5) interaction, which serves as a hook. The reaction proceeds via a sigma bond metathesis where the fluorine ortho to the hook migrates toward H with a relatively low activation energy. All products observed experimentally are accommodated by pathways that involve C-F and C-H bond cleavages.

  9. Clostridium botulinum strain Af84 contains three neurotoxin gene clusters: bont/A2, bont/F4 and bont/F5.

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    Nir Dover

    Full Text Available Sanger and shotgun sequencing of Clostridium botulinum strain Af84 type Af and its botulinum neurotoxin gene (bont clusters identified the presence of three bont gene clusters rather than the expected two. The three toxin gene clusters consisted of bont subtypes A2, F4 and F5. The bont/A2 and bont/F4 gene clusters were located within the chromosome (the latter in a novel location, while the bont/F5 toxin gene cluster was located within a large 246 kb plasmid. These findings are the first identification of a C. botulinum strain that contains three botulinum neurotoxin gene clusters.

  10. Superhalogen properties of hetero-binuclear anions MM‧F4- and MM″F5- (M = Li, Na, M‧ = Be, Mg, Ca; M″ = B, Al, Ga)

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    Yang, Hui; Li, Ying; He, Hui-Min; Tong, Jing; Wu, Di; Li, Zhi-Ru

    2017-09-01

    Hetero-binuclear superhalogen anions, namely MM‧F4- and MM″F5- (M = Li, Na; M‧ = Be, Mg, Ca; M″ = B, Al, Ga), have been theoretically characterized at the MP2(FULL)/6-311+G(3df) level. It is found that two central atoms can be linked by at most three fluorine ligands. The large vertical electron detachment energies (VDEs, 7.449-8.978 eV) verify the superhalogen identity of these anions. The VDEs of both MM‧F4- and MM″F5- decrease when the atomic size of M increases whereas increase with the size of M‧ and M″. Besides, the extra electron distribution also has effect on the VDEs of such superhalogen anions.

  11. E2F-4 and E2F-5, two members of the E2F family, are expressed in the early phases of the cell cycle.

    OpenAIRE

    Sardet, C; Vidal, M.; Cobrinik, D; Y. Geng; Onufryk, C; Chen, A; Weinberg, R A

    1995-01-01

    The E2F transcription factors play a role in regulating the expression of genes required for cell proliferation. Their activity appears to be regulated by association with the retinoblastoma protein (pRb) and the pRb-related proteins p107 and p130. In vivo, pRb is found in complex with a subset of E2F components--namely, E2F-1, E2F-2, and E2F-3. Here we describe the characterization of cDNAs encoding two unusual E2Fs, E2F-4 and E2F-5, each identified by the ability of their gene product to in...

  12. Estimation of enthalpy data for reactions involving gas phase ions utilizing lattice potential energies: fluoride ion affinities (FIA) and pF- values of mSbF5(l) and mSbF5(g) (m = 1, 2, 3), AsF5(g), AsF5.SO2(c). Standard enthalpies of formation: Delta(f)H degrees (SbmF5m+1)(-),g) (m = 1, 2, 3), Delta(f)H degrees (AsF6(-),g), and Delta(f)H degrees (NF4+,g).

    Science.gov (United States)

    Jenkins, H Donald Brooke; Roobottom, H K; Passmore, Jack

    2003-05-01

    Fluoride ion affinity (FIA) values (and the associated pF(-) values) are difficult to establish experimentally for pentafluorides of arsenic and antimony. Our approach, utilizing estimated lattice potential energies, provides a further opportunity to establish this data for liquid (and gaseous) SbF(5) and gaseous AsF(5) which compliments values obtained using ab initio routes for monomeric gas phase molecules and adds to results based on rigorous methods. A strategy is developed whereby construction of (multiple) Born-Fajans-Haber cycles centered around the (target) FIA reaction of interest yield a plethora of estimates for the enthalpy change of interest. This general approach is illustrated here by specific estimation of some experimentally based FIA values of SbF(5) and AsF(5). FIA values/kJ mol(-1) and pF- values estimated in this paper are FIA(SbF(5),l) approximately equal to -475 (+/-63), pF-(SbF(5),l) = 11.4 (+/-1.5); FIA(SbF(5),g) approximately equal to -506 (+/-63), pF-(SbF(5),g) = 12.4 (+/-1.5); FIA(2SbF(5),l) approximately equal to -609 (+/-63), pF- (2SbF(5),l) = 14.6 (+/-1.5); FIA (2SbF(5),g) approximately equal to -671 (+/-63), pF- (2SbF(5),g) = 16.0 (+/-1.5); FIA (3SbF(5),l) approximately -635 (+/-39), pF(-) (3SbF(5),l) = 15.2 (+/-0.9); FIA(3SbF(5),g) approximately -728 (+/-39), pF(-) (3SbF(5),g) = 17.4 (+/-0.9); FIA(AsF(5),g) approximately equal to -421 (+/-22), pF(-) (AsF(5),g) = 10.1 (+/- 0.5); and FIA (AsF(5).SO(2),s) approximately equal to -390 (+/-22), pF(-) (AsF(5).SO(2),s) = 9.3 (+/-0.5). Related standard enthalpies of formation (in kJ mol(-1)) are also assigned: Delta(f)H degrees (SbF(6)(-),g) approximately equal to -2075 (+/-52); Delta(f)H degrees (Sb(2)F(11)(-),g) approximately equal to -3520 (+/-63); Delta(f)H degrees (Sb(3)F(16)(-),g) approximately equal to -4874 (+/-39); Delta(f)H degrees (NF(4)(+),g) approximately equal to 903 (+/-32); Delta(f)H degrees (AsF(6)(-),g) approximately equal to -1907 (+/-22).

  13. On the reactivity of F(3)S[triple bond]NXeF(+): syntheses and structural characterizations of [F(4)S=N-Xe---N[triple bond]SF(3)][AsF(6)], a rare example of a N-Xe-N linkage, and [F(3)S(N[triple bond]SF(3))(2)][AsF(6)].

    Science.gov (United States)

    Smith, Gregory L; Schrobilgen, Gary J

    2009-08-17

    The F(4)S=N-Xe---N[triple bond]SF(3)(+) cation has been synthesized as the AsF(6)(-) salt by rearrangement of [F(3)S[triple bond]NXeF][AsF(6)] in N[triple bond]SF(3) solvent at 0 degrees C. Deep yellow [F(4)S=N-Xe---N[triple bond]SF(3)][AsF(6)], which crystallized from a N[triple bond]SF(3) solution at -10 degrees C, was characterized by Raman spectroscopy (-160 degrees C) and by single-crystal X-ray diffraction (-173 degrees C). The Xe-N bond length (2.079(3) A) of the F(4)S=N-Xe---N[triple bond]SF(3)(+) cation is among the shortest Xe-N bonds presently known. The F(4)S=NXe(+) cation interacts with N[triple bond]SF(3) by means of a Xe---N donor-acceptor bond (2.583(3) A) that is significantly longer than the primary Xe-N bond (2.079(3)A) but significantly shorter than the sum of the Xe and N van der Waals radii (3.71 A). The F(4)S=N-Xe---N[triple bond]SF(3)(+) cation undergoes a redox decomposition in N[triple bond]SF(3) at 0 degrees C, forming [F(3)S(N[triple bond]SF(3))(2)][AsF(6)], cis-N(2)F(2), and Xe, which were characterized by low-temperature Raman spectroscopy in the solid state and by (19)F NMR spectroscopy in N[triple bond]SF(3) solvent (0 degrees C). Colorless [F(3)S(N[triple bond]SF(3))(2)][AsF(6)] crystallized from N[triple bond]SF(3) at -10 degrees C and was characterized by low-temperature, single-crystal X-ray diffraction. The S(IV) atom of F(3)S(N[triple bond]SF(3))(2)(+) has long contacts with the N atoms of two N[triple bond]SF(3) molecules and a F ligand of a neighboring AsF(6)(-) anion. The arrangement of long contacts avoids, to the maximum extent, the F atoms of SF(3)(+) and the nonbonding electron pair situated on the pseudo-3-fold axis opposite the F ligands of SF(3)(+), providing distorted octahedral coordination about the S(IV) atom. Quantum-chemical calculations using MP2, B3LYP, and PBE1PBE methods were employed to arrive at the gas-phase geometries, charges, bond orders, valencies, and vibrational frequencies for F(4)S

  14. Metodología para evaluar progenies F5 a partir de selecciones individuales F4 de fríjol voluble en el sistema de relevo con maíz F5 lines from individuals selections of voluble bean intercropped with maize

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    Roman V. Alberto

    1988-12-01

    Full Text Available En el Centro Regional de Investiga, ción, ICA "La Selva", situado en el municipio de Rionegro, Antioquia, Colombia, se
    sembraron ocho ensayos entre 1986 y 1987, con el fin de determinar una nueva metodología para evaluar progenies F5, de fríjol voluble (Phaseolus vulgaris L. en el sistema
    de relevo con maíz (Zea mays L.. Se encontró que el sistema de parcelas pequeñas (0,84 m2 sirve para evaluar y tamizar grandes cantidades de material en lo que respecta al rendimiento, el peso de 100 semillas, días a madurez fisiológica y días a floración, util izando cuatro replicaciones. Se obtiene así un ahorro del 77 ,76% del área sembrada, en comparación con la siembra en parcelas de seis sitios y tres replicaciones, disminuyendo de esta manera los costos de la investigación.A series of eigth experiments were carried out at "la Selva" ICA's Experiment Station, located at Rionegro, Antioquía,
    Colombia at 2.100 m.s.n.m. between 1986 and 1987. The objetive was to determine a new methodology for the evaluation of F5 bean (Phaseolus vulgaris l. lines in relay intercropped planted with maize (Zeamsys l. It was found, for advanced lines, that one hill-plots (0.84 m-2 were not useful for detecting significant differences, but for F5 materials it was found that 4 replicates allowed to detect differences. The aboye result for F5 lines will permit to save 77 .8% of the area normally used in such works, i.e. by employing 6 hill plots and 3 replicates.

  15. The synthesis and crystal structures of halogenated tolans p-X-C6H4-C[triple bond]C-C6F5 and p-X-C6F4-C[triple bond]C-C6H5(X=F, Cl, Br, I).

    Science.gov (United States)

    Collings, Jonathan C; Burke, Jacquelyn M; Smith, Philip S; Batsanov, Andrei S; Howard, Judith A K; Marder, Todd B

    2004-11-07

    A series of halogenated, partially fluorinated tolans of general formula p-X-C6H4-C[triple bond]C-C6F5[X=I (1), Br (2), Cl (3), F (4)] and p-X-C6F4-C[triple bond]C-C6H5[X=I (5), Br (6)] have been prepared via palladium-catalysed Sonogashira cross-coupling, or for X=Cl (7), by nucleophilic aromatic substitution reactions. The single-crystal X-ray structures of 1-3 and 5-6 have been determined. The structures reveal that the molecular packing is characterized by either arene-perfluoroarene interactions (3), or halogen-halogen interactions (isomorphous 1 and 2), or neither (isomorphous 5 and 6). The structure of represents the first fully determined crystal structure of a compound that contains a halogen atom other than fluorine, in which arene-perfluoroarene interactions are present.

  16. F-5M DTA Program

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    Daniel Ferreira V. Mattos

    2009-01-01

    Full Text Available The Brazilian F-5 was submitted to avionics and weapons upgrade. This “new” aircraft has proven to be heavier and more capable. A comprehensive damage tolerance analysis is being performed to evaluate how the new mission profiles and weight distribution may affect the airframe structural integrity. Operational data were collected at the Brazilian Air Force Bases where the fighter is flown. Software was developed in order to acquire, filter and analyze flight data. This data was used for comparison between the pre and post modernization mission profiles and to determine the stress level in each of the known aircraft fatigue critical locations (FCL. The results show that the change in aircraft weight and balance and the new operational profile can significantly change the inspection intervals of certain fatigue critical locations of the structure. A preliminary result for the horizontal tail has shown that this component will have a much more restrictive maintenance schedule to assure flight safety.

  17. of Nd3+ions in YLiF4 and LuLiF4 crystals

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    André Felipe Henriques Librantz

    2006-01-01

    Full Text Available Nd3+ ultraviolet (UV fluorescence induced by multiphotonic laser excitations was studied in doped Nd:YLiF4 (YLF and Nd:LuLiF4 (LLF crystals by using the time resolved spectroscopy technique. The UV luminescences are due to transitions between the 4f25d and the 4f3 electronic configurations of Nd3+ ions. The 4f25d configuration can be reached by direct pumping or by multiphotonic excitation, both processes give rise to the UV band emission with structure due to the strong phonon coupling expected for 5d orbital involvement in the transition. The multiphotonic excitation process is due to three photons (532 nanometers [nm] sequential absorptions by metastable levels of the 4f3 configuration split by crystalline local field. The sequential excitation of Nd by the laser excitation is attributed to the 4I9/2 + 532 nm t 4G7/2 ground state absorption followed by the 4G7/2 + 532 nm t 2F5/2 and 2F5/2 + 532 nm t 4f25d excited state absorptions. The UV emissions due to 4f25d configuration are parity allowed, having lifetime of 35 nanoseconds (ns in contrast to UV emissions from 4f3 configuration which are induced by two absorption steps and are parity forbidden showing longer lifetime of 8 microseconds (ms and narrow lines. The polarization effects of the UV emissions were studied and their behaviors are dependent on the excited state configuration involving or not involving the 5d orbital. The allowed UV emission positions were affected by the host variation more than the ones originated from the 4f3 configuration as expected. The electronic energy of the 4f25d configuration shifts to lower energy for increasing the crystal field.

  18. Isolation and structures of sulfonium salts derived from thioethers: [{o-C(6)H(4)(CH(2)SMe)(2)}H][NbF(6)] and [{[9]aneS(3)}H][NbF(6)].

    Science.gov (United States)

    Jura, Marek; Levason, William; Reid, Gillian; Webster, Michael

    2009-10-07

    Two very unusual sulfonium salts, [{o-C(6)H(4)(CH(2)SMe)(2)}H][NbF(6)] and [{[9]aneS(3)}H][NbF(6)], obtained from reaction of the thioethers with NbF(5) in CH(2)Cl(2) solution, are reported and their structures described; the eight-coordinate tetrafluoro Nb(v) cation of the dithioether is obtained from the same reaction.

  19. Adsorption behaviour of PuF6 on UO2F2 by the use of 236Pu

    Science.gov (United States)

    Sato, Nobuaki; Matsuda, Minoru; Mitsugashira, Toshiaki; Kirishima, Akira

    2010-03-01

    To know the behavior of plutonium in the fluoride volatility process (FLUOREX PROCESS) for the spent nuclear fuel, both UO2 and PuO2 are fluorinated by fluorine forming volatile UF6 and PuF6, respectively. Then PuF6 is separated and recovered from UF6 by using adsorption materials such as uranyl fluoride UO2F2. In this paper, adsorption behavior of PuF6on UO2F2 was examined by the use of 236Pu tracer. First, the stability of UO2F2 in F2atmosphere was analyzed by TG-DTA method showing that uranium volatilized completely over 350 °C by the formation of UF6 and the adsorption of plutonium by UO2F2 should be done at temperatures lower than 250 °C. The behavior of PtF6 as a chemical analogue of PuF6 was also conducted for comparison and it showed that the deposition of PtF4 on UO2F2 at 200 °C. When the 236Pu doped U3O8 was reacted with 10%F2-He gas, the PuF6 vaporized at ca. 600 °C. Then adsorption of 236Pu on UO2F2 was observed by α ray measurement. The adsorption mechanism of Pu on UO2F2 was discussed with experimental data and thermodynamic consideration.

  20. Genetic parameters and selection for resistance to bacterial spot in recombinant F6 lines of Capsicum annuum

    Directory of Open Access Journals (Sweden)

    Messias Gonzaga Pereira

    2009-01-01

    Full Text Available This study aimed to advance generations and select superior sweet pepper genotypes with resistance tobacterial spot, using the breeding method Single Seed Descent (SSD based on the segregating population derived from thecross between Capsicum annuum L. UENF 1421 (susceptible, non-pungent and UENF 1381 (resistant, pungent. Thesegregating F3 generation was grown in pots in a greenhouse until the F5 generation. The F6 generation was grown in fieldconditions. The reaction to bacterial spot was evaluated by inoculation with isolate ENA 4135 of Xanthomonas campestris pv.vesicatoria, based on a score scale and by calculating the area under the disease progress curve (AUDPC. The presence orabsence of capsaicin was also assessed. Eighteen F6 lines were bacterial leaf spot-resistant. Since no capsaicin was detectedin the F6 lines 032, 316, 399, 434, and 517, these will be used in the next steps of the sweet pepper breeding program.

  1. Solubility of Malladrite Na2SiF6 and K2SiF6 in aqueous solutions

    Directory of Open Access Journals (Sweden)

    Skafi M.

    2013-09-01

    Full Text Available The water activities of binary solutions Na2SiF6-H2O and K2SiF6-H2O are measured from dilution to saturation using the hygrometric method at temperature 353 K. From these experimental data, the activity coefficients of solute were calculated using parameters of ionic interaction model. These coefficients are used to predict the solubility products of the K°sp, the free energy ΔG°diss of dissolution and also the characterization of the precipitated phases to saturation of the system containing Na2SiF6 or K2SiF6. The analyzed of solid phase obtained from saturated solution is made by Xray- diffraction.

  2. Rerefinement of K-2[TiF6

    NARCIS (Netherlands)

    Gobel, O

    2000-01-01

    Crystals of dipotassium hexafluorotitanate(IV), K-2[TiF6], were grown from aqueous solution. The crystal structure was refined with anisotropic displacement parameters. Ti4+ is octahedrally coordinated by F- (point group (3) over bar m), and K+ is 12-coordinate (point group 3m). The dispersion of bi

  3. Cleanup Verification Package for the 118-F-6 Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    H. M. Sulloway

    2008-10-02

    This cleanup verification package documents completion of remedial action for the 118-F-6 Burial Ground located in the 100-FR-2 Operable Unit of the 100-F Area on the Hanford Site. The trenches received waste from the 100-F Experimental Animal Farm, including animal manure, animal carcasses, laboratory waste, plastic, cardboard, metal, and concrete debris as well as a railroad tank car.

  4. Mapping the geometry of the F4 group

    Energy Technology Data Exchange (ETDEWEB)

    Bernardoni, Fabio; Cacciatori, Sergio L; Scotti, Antonio; Cerchiai, Bianca L.

    2007-05-28

    In this paper, we present a construction of the compact form of the exceptional Lie group F4 by exponentiating the corresponding Lie algebra f4. We realize F4 as the automorphisms group of the exceptional Jordan algebra, whose elements are 3 x 3 Hermitian matrices with octonionic entries. We use a parametrization which generalizes the Euler angles for SU(2) and is based on the fibration of F4 via a Spin(9) subgroup as a fiber. This technique allows us to determine an explicit expression for the Haar invariant measure on the F4 group manifold. Apart from shedding light on the structure of F4 and its coset manifold OP2 = F4/Spin(9), the octonionic projective plane, these results are a prerequisite for the study of E6, of which F4 is a (maximal) subgroup.

  5. Quasiclassical Trajectory Study of Collisional Energy Transfer between Highly Excited C6F6 and N2 ,O2 and Ground State C6F6

    Institute of Scientific and Technical Information of China (English)

    Jian Hua ZHOU; Shao Kun WANG; Zhi Jun YU; Hai Hui JIANG; Yue Shu GU

    2003-01-01

    Quasiclassical trajectory calculation (QCT) is used frequently for studying collisional energy transfer between highly vibrationally excited molecules and bath gases. In this paper, the QCT of the energy transfer between highly vibrationally excited C6F6 and N2 ,O2 and ground state C6F6 were performed. The results indicate that highly vibrationally excited C6F6 transferred vibrational energy to vibrational distribution of N2, O2 and ground state C6F6, so they are V-V energy transfer. Especially it is mainly V-V resonance energy transfer between excited C6F6 and ground state C6F6, excited C6F6 transfers more vibrational energy to ground state C6F6 than to N2 and O2 . The values of QCT , -〈△Evib〉of excited C6F6 are smaller than those of experiments.

  6. Analysis list: E2f4 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available E2f4 Blood,Embryonic fibroblast,Liver,Muscle,Pluripotent stem cell + mm9 http://dba...rchive.biosciencedbc.jp/kyushu-u/mm9/target/E2f4.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/E2f4....5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/E2f4.10.tsv http://dbarchive.biosciencedbc....jp/kyushu-u/mm9/colo/E2f4.Blood.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/E2f4....Embryonic_fibroblast.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/E2f4.Liver.tsv,htt

  7. A novel scandium fluoride, [C2N2H10]0.5[ScF4], with an unprecedented tungsten bronze-related layer structure.

    Science.gov (United States)

    Stephens, Nicholas F; Slawin, Alexandra M Z; Lightfoot, Philip

    2004-03-07

    [C(2)N(2)H(10)](0.5)[ScF(4)] exhibits isolated anionic layers of corner-linked ScF(6) octahedra enclosing 3-, 4-, 5- and 6-membered rings, with features reminiscent of both hexagonal and tetragonal tungsten bronze-type structures.

  8. F5D-1 on ramp with Neil Armstrong preparing to fly a Dyna-Soar simulation

    Science.gov (United States)

    1962-01-01

    The Douglas F5D-1 Skylancer being pre-flighted by the pilot while the crew chief prepares to pull the wheel chocks on the 'hot gun' ramp at Edwards Air Force Base, California. The aircraft was one of two prototype F5D-1s obtained by NASA Flight Research Center in 1961. The F5D-1 Skylancer (Bu. No. 142350) had a red and white paint pattern with a NASA identification number of 213 which later became NASA 708. The Douglas F5D-1 Skylancer was built by the Navy as an all-weather fighter interceptor that never made the jump to production. Four test aircraft were developed with the same basic airframe as the Douglas F4D Skyray. With increasing modifications the four aircraft were re-designated F5D-1s before their first flights. Future Astronaut Neil Armstrong was one of the NASA research pilots assigned to support duties for the Dyna-Soar program. In addition to working at the Boeing facility in Washington state, Armstrong also tested the Dyna-Soar launch abort profile using this F5D-1, which had a similar wing shape to the Dyna-Soar. The aircraft arrived at the Flight Research Center on June 15, 1961. After the Dyna-Soar program was cancelled in December 1963, this F5D-1 continued to be used, serving as a flying simulator for the M2-F2 and as a chase plane for lifting-body flights (providing the lifting-body pilot with an extra set of eyes to assist in emergencies and avert potential crashes) This F5D-1 left the Flight Research Center (later designated the Dryden Flight Research Center) on May 19, 1970, and was donated to the Neil A. Armstrong Museum in Wapakoneta, Ohio.

  9. Imaging malignant melanoma with {sup 18}F-5-FPN

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Hongyan; Xia, Xiaotian; Li, Chongjiao; Song, Yiling; Qin, Chunxia; Liu, Qingyao; Zhang, Yongxue; Lan, Xiaoli [Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology (China); Hubei Key Laboratory of Molecular Imaging (China)

    2016-01-15

    Radiolabelled benzamides are attractive candidates for targeting melanoma because they bind to melanin and exhibit high tumour uptake and retention. {sup 18}F-5-Fluoro-N-(2-[diethylamino]ethyl)picolinamide ({sup 18}F-5-FPN), a benzamide analogue, was prepared and its pharmacokinetics and binding affinity evaluated both in vitro and in vivo to assess its clinical potential in the diagnosis and staging of melanoma. {sup 18}F-5-FPN was prepared and purified. Its binding specificity was measured in vitro in two different melanoma cell lines, one pigmented (B16F10 cells) and one nonpigmented (A375m cells), and in vivo in mice xenografted with the same cell lines. Dynamic and static PET images using {sup 18}F-5-FPN were obtained in the tumour-bearing mice, and the static images were also compared with those acquired with {sup 18}F-FDG. PET imaging with {sup 18}F-5-FPN was also performed in B16F10 tumour-bearing mice with lung metastases. {sup 18}F-5-FPN was successfully prepared with radiochemical yields of 5 - 10 %. Binding of {sup 18}F-5-FPN to B16F10 cells was much higher than to A375m cells. On dynamic PET imaging B16F10 tumours were visible about 1 min after injection of the tracer, and the uptake gradually increased over time. {sup 18}F-5-FPN was rapidly excreted via the kidneys. B16F10 tumours were clearly visible on static images acquired 1 and 2 h after injection, with high uptake values of 24.34 ± 6.32 %ID/g and 16.63 ± 5.41 %ID/g, respectively, in the biodistribution study (five mice). However, there was no visible uptake by A375m tumours. {sup 18}F-5-FPN and {sup 18}F-FDG PET imaging were compared in B16F10 tumour xenografts, and the tumour-to-background ratio of {sup 18}F-5-FPN was ten times higher than that of {sup 18}F-FDG (35.22 ± 7.02 vs. 3.29 ± 0.53, five mice). {sup 18}F-5-FPN PET imaging also detected simulated lung metastases measuring 1 - 2 mm. {sup 18}F-5-FPN specifically targeted melanin in vitro and in vivo with high retention and affinity

  10. Transmission of F4+ E. coli in groups of early weaned piglets

    NARCIS (Netherlands)

    Geenen, P.L.; Döpfer, D.; Meulen, van der J.; Jong, de M.C.M.

    2005-01-01

    The aim of this study was to estimate transmission parameters of enterotoxigenic F4+ Escherichia coli F4 (F4+ E. coli) in groups of early weaned piglets with F4-receptor-positive (F4R+) and F4-receptor-negative piglets (F4R[minus sign]). Transmission of F4+ E. coli was quantified in four

  11. Enhanced 1G 4 emission in NaLaF 4: Pr 3+, Yb 3+ and charge transfer in NaLaF 4: Ce 3+, Yb 3+ studied by fourier transform luminescence spectroscopy

    Science.gov (United States)

    van der Kolk, E.; Ten Kate, O. M.; Wiegman, J. W.; Biner, D.; Krämer, K. W.

    2011-05-01

    A high resolution luminescence study of NaLaF 4: 1%Pr 3+, 5%Yb 3+ and NaLaF 4: 1%Ce 3+, 5%Yb 3+ in the UV to NIR spectral range using a InGaAs detector and a fourier transform interferometer is reported. Although the Pr 3+( 3P 0 → 1G 4), Yb 3+( 2F 7/2 → 2F 5/2) energy transfer step takes place, significant Pr 3+1G 4 emission around 993, 1330 and 1850 nm is observed. No experimental proof for the second energy transfer step in the down-conversion process between Pr 3+ and Yb 3+ can be given. In the case of NaLaF 4: Ce 3+, Yb 3+ it is concluded that the observed Yb 3+ emission upon Ce 3+ 5d excitation is the result of a charge transfer process instead of down-conversion.

  12. Laser photodetachment in liquids: C 6F -6 in tetramethylsilane

    Science.gov (United States)

    Faidas, H.; Christophorou, L. G.; McCorkle, D. L.

    1992-06-01

    The photodetachment cross section of C 6F -6 in liquid tetramethylsilane was measured as a function of the photon energy, using a new two laser photoconductivity technique. The photodetachment threshold was found to be 1.51 eV using a 3/2 power threshold law. Two maxima were observed in the photodetachment cross section at photon energies of 2.58 and 3.15 eV; the cross section value at these two maxima is ≈ 11 × 10 -18 cm 2.

  13. Defining the service value of Hotel F6

    OpenAIRE

    Tapala, Jasmin

    2017-01-01

    This thesis is about creating memorable customer experiences and identifying how to create additional value to a service product. It’s created as a manual for hospitality companies’, in this case Hotel F6’s benefit and guidebook to define how to survive in experience economy and to create a business strategy with focus on individual customers and their needs. In the theory part meaning of an experience is explained and the subject (and the importance) of creating memorable experiences is ...

  14. Molecular CsF 5 and CsF 2 +

    KAUST Repository

    Rogachev, Andrey Yu.

    2015-06-03

    D5h star-like CsF5, formally isoelectronic with known XeF5− ion, is computed to be a local minimum on the potential energy surface of CsF5, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F2, or to CsF3 (three isomeric forms)+F2, or for rearrangement to a significantly more stable isomer, a classical Cs+ complex of F5−. Similarly the CsF2+ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

  15. Estimating transmission parameters of F4 + E. coli for F4-receptor-positive and -negative piglets: one-to-one transmission experiment

    NARCIS (Netherlands)

    Geenen, P.L.; Meulen, van der J.; Bouma, A.; Jong, de M.C.M.

    2004-01-01

    F4+ Escherichia coli is an important agent of post-weaning diarrhoea in piglets. Piglets that express an adhesion site for F4+ E. coli in their small intestine (F4R+) shed higher numbers of F4+ E. coli than piglets lacking this site (F4R[minus sign]). We hypothesized that F4R+ piglets are more

  16. Preliminary Study on LiF4-ThF4-PuF4 Utilization as Fuel Salt of miniFUJI Molten Salt Reactor

    Science.gov (United States)

    Waris, Abdul; Aji, Indarta K.; Pramuditya, Syeilendra; Widayani; Irwanto, Dwi

    2016-08-01

    miniFUJI reactor is molten salt reactor (MSR) which is one type of the Generation IV nuclear energy systems. The original miniFUJI reactor design uses LiF-BeF2-ThF4-233UF4 as a fuel salt. In the present study, the use of LiF4-ThF4-PuF4 as fuel salt instead of LiF-BeF2-ThF4-UF4 will be discussed. The neutronics cell calculation has been performed by using PIJ (collision probability method code) routine of SRAC 2006 code, with the nuclear data library is JENDL-4.0. The results reveal that the reactor can attain the criticality condition with the plutonium concentration in the fuel salt is equal to 9.16% or more. The conversion ratio diminishes with the enlarging of plutonium concentration in the fuel. The neutron spectrum of miniFUJI MSR with plutonium fuel becomes harder compared to that of the 233U fuel.

  17. Thiazyl Trifluoride (NSF3) Adducts and Imidodifluorosulfate (F2OSN-) Derivatives of Hg(OTeF5)2.

    Science.gov (United States)

    DeBackere, John R; Mercier, Hélène P A; Schrobilgen, Gary J

    2015-10-19

    Reactions of Hg(OTeF5)2 with excess amounts of NSF3 at 0 °C result in the formation of NSF3 adducts having the compositions [Hg(OTeF5)2·N≡SF3]∞ (1), [Hg(OTeF5)2·2N≡SF3]2 (2), and Hg3(OTeF5)6·4N≡SF3 (3). When the reactions are carried out at room temperature, oxygen/fluorine metatheses occur yielding the F2OSN- derivatives [Hg(OTeF5)(N═SOF2)·N≡SF3]∞ (4) and [Hg3(OTeF5)5(N═SOF2)·2N≡SF3]2 (5). The proposed reaction pathway leading to F2OSN- group formation occurs by nucleophilic attack by a F5TeO- group at the sulfur(VI) atom of NSF3, followed by TeF6 elimination. Tellurium hexafluoride formation was confirmed by (19)F NMR spectroscopy. The NSF3 molecules are terminally N-coordinated to mercury, whereas the F2OSN- ligands are N-bridged to two mercury atoms. The compound series was characterized by low-temperature single-crystal X-ray diffraction and low-temperature Raman spectroscopy. Several structural motifs are observed within this structurally diverse series. These include the infinite chain structures of the related compounds, 1 and 4; 2, a dimeric structure which possesses an (HgO(μ))2 ring at its core; 3, a structure based on a cage comprised of a (HgO(μ))3 ring that is capped on each face by μ(3)-oxygen bridged F5TeO- groups; and 5, a dimeric structure possessing two distorted (Hg3O2N) rings that are formally derived from 3 by replacement of a F5TeO- group by a F2OSN- group in each ring. Quantum-chemical calculations were carried out to gain insight into the bonding of the μ(3)-oxygen bridged teflate groups observed in structure 3. Compounds 1-5 represent a novel class of neutral transition metal complexes with NSF3, providing the first examples of NSF3 coordination to mercury. Compounds 4 and 5 also provide the only examples of F2OSN- derivatives of mercury that have been characterized by single-crystal X-ray diffraction.

  18. Comparative study of global warming effects during silicon nitride etching using C3F6O/O2 and C3F6/O2 gas mixtures

    Science.gov (United States)

    Kim, Ka Youn; Moon, Hock Key; Lee, Nae-Eung; Hong, Bo Han; Oh, Soo Ho

    2015-01-01

    C3F6 and C3F6 gases were investigated as replacement gases for SF6 used in display industry due to their low global warming potential and short lifetime. In the C3F6/O2 and C3F6/O2 capacitively coupled plasmas, Si3N4 etch conditions were varied by controlling process parameters. The global warming effects were quantified as million metric ton carbon equivalents (MMTCEs) obtained from the volumetric emission of by-product and etch gases. A lower MMTCE value and higher etch rate process with combination of high and low source frequencies, f HF (27.12 MHz)/ f LF (2 MHz), were observed for the C3F6/O2 chemistry than for the C3F6/O2 chemistry.

  19. Liquidus Temperatures of System Na3AlF6-K3AlF6-AlF3 for Aluminum Electrolysis at Lower Temperature

    Institute of Scientific and Technical Information of China (English)

    WEI Chen-juan; LAI Yan-qing; LI Jie; TIAN Zhong-liang; WANG Jia-wei; ZOU Zhong; LIU Ye-xiang

    2011-01-01

    Liquidus temperatures in the molten salt system Na3AlF6-K3AlF6-AlF3 of interest for aluminum electrolysis were determined by thermal analysis method.The results were presented and an empirical equation describing liquidus temperatures for primary crystallization was derived t=1003.5-0.081 ×A2.3159-5.87×B0.657-0.024×A2.22×B1.14+0.035×A2.17×B1.084,where t is the liquidus temperature in degree Celsius,A denotes the mass fraction of AlF3 in system Na3AlF6-K3AlF6-AlF3,and B denotes K3A1F6/(Na3AlF6+K3AlF6)in mass(%,the value was defined as KR in this paper).The composition limitations are 0<w(AlF3)<30%,and 0<KR<50%.The isothermal diagram of molten salt system Na3AlF6-K3A1F6-AlF3 was obtained in this composition limitation.

  20. Substitution of fluorine in M[C6F5BF3] with organolithium compounds: distinctions between O- and N-nucleophiles

    Directory of Open Access Journals (Sweden)

    Anton Yu. Shabalin

    2017-04-01

    Full Text Available Borates M[C6F5BF3] (M = K, Li, Bu4N react with organolithium compounds, RLi (R = Me, Bu, Ph, in 1,2-dimethoxyethane or diglyme to give M[4-RC6F4BF3] and M[2-RC6F4BF3]. When R is Me or Bu, the nucleophilic substitution of the fluorine atom at the para position to boron is the predominant route. When R = Ph, the ratio M[4-RC6F4BF3]/M[2-RC6F4BF3] is ca. 1:1. Substitution of the fluorine atom at the ortho position to boron is solely caused by the coordination of RLi via the lithium atom with the fluorine atoms of the BF3 group. This differs from the previously reported substitution in K[C6F5BF3] by O- and N-nucleophiles that did not produce K[2-NuC6F4BF3].

  1. Refined localization of the Escherichia coli F4ab/F4ac receptor locus on pig chromosome 13.

    Science.gov (United States)

    Joller, D; Jørgensen, C B; Bertschinger, H U; Python, P; Edfors, I; Cirera, S; Archibald, A L; Bürgi, E; Karlskov-Mortensen, P; Andersson, L; Fredholm, M; Vögeli, P

    2009-10-01

    Diarrhoea in newborn and weaned pigs caused by enterotoxigenic Escherichia coli (ETEC) expressing F4 fimbriae leads to considerable losses in pig production. In this study, we refined the mapping of the receptor locus for ETEC F4ab/F4ac adhesion (F4bcR) by joint analysis of Nordic and Swiss data. A total of 236 pigs from a Nordic experimental herd, 331 pigs from a Swiss experimental herd and 143 pigs from the Swiss performing station were used for linkage analysis. Genotyping data of six known microsatellite markers, two newly developed markers (MUC4gt and HSA125gt) and an intronic SNP in MUC4 (MUC4-8227) were used to create the linkage map. The region for F4bcR was refined to the interval SW207-S0075 on pig chromosome 13. The most probable position of F4bcR was in the SW207-MUC4 region. The order of six markers was supported by physical mapping on the BAC fingerprint contig from the Wellcome Trust Sanger Institute. Thus, the region for F4bcR could be reduced from 26 to 14 Mb.

  2. [Phosphate solubilization of Aureobasidium pullulan F4 and its mechanism].

    Science.gov (United States)

    Wang, Dan; Zhan, Jing; Sun, Qing-Ye

    2014-07-01

    The Aureobasidium pullulans F4 was isolated from the rhizosphere of Hippochaete ramosissimum in Tongguanshan mine wasteland in Tongling City, Anhui Province. Liquid culture was conducted with four kinds of phosphorus sources, calcium phosphate, aluminum phosphate, ferric phosphate and rock phosphate to determine the pH, dissolved phosphorus, phosphorus in the bacteria and organic acid in the solution. The results showed that the phosphate solubilization by A. pullulans F4 varied with phosphorus sources, which decreased in order of aluminum phosphate > ferric phosphate, calcium phosphate > rock phosphate. The amounts of dissolved phosphorus in the different treatments were all higher than 200 mg x L(-1). The pH of the medium dropped immediately in 48 h, and the aluminum phosphate and ferric phosphate treatments showed a greater decrease in pH than the calcium phosphate and rock phosphate treatments. The organic acid synthesized by A. pullulans F4 included oxalic acid, citric acid and tartaric acid, and oxalic acid, among which oxalic acid was the dominated component. The phosphate dissolving capacity of A. pullulans F4 showed no significant correlation with organic acid, but significantly correlated with the pH. The available phosphorus was significantly improved with the combined application of A. pullulans F4 and glucose, suggesting A. pullulans F4 was a potent candidate for remediation of copper mine wastelands.

  3. TRAPPIST monitoring of comet C/2012 F6 (Lemmon)

    Science.gov (United States)

    Opitom, C.; Jehin, E.; Manfroid, J.; Hutsemékers, D.; Gillon, M.; Magain, P.

    2015-02-01

    We report the results of the long-term narrowband photometry and imaging monitoring of comet C/2012 F6 (Lemmon) with the robotic TRAPPIST telescope (La Silla Observatory). Observations covered 52 nights pre- and post-perihelion between December 11, 2012, and June 11, 2013 (perihelion: 24 March, 2013). We followed the evolution of the OH, NH, CN, C3, and C2 production rates computed with the Haser model as well as the evolution of the A(θ)fρ parameter as a proxy for the dust production. All five gas species display similar slopes for the heliocentric dependence. An asymmetry about perihelion is observed, the rate of brightening being steeper than the rate of fading. The chemical composition of the comet's coma changes slightly along the orbit: the relative abundance of C2 to CN increases with the heliocentric distance (r) below -1.4 au and decreases with r beyond 1.4 au while the C3-to-CN ratio is constant during our observations. The behavior of the dust is different from that of the gas, the slope of the heliocentric dependence becoming steeper in early February, correlated to a change in the visual lightcurve slope. However, the dust color does not vary during the observations. The application of several enhancement techniques on the images revealed structures in the CN, C3, and C2 images. These features imply the existence of one or several active zone(s) on the comet nucleus. The shape of the structures is similar in these three filters and changes from a roughly hourglass shape in December and January to a corkscrew shape in February and March. The structures in the continuum filters (sampling the dust) are not correlated to those observed for the gas. During several full nights in February, we observed changes in the CN and C2 structures that repeated periodically because of the nucleus rotation, our derived rotational period being of 9.52 ± 0.05 h. Full Tables 2, 4, 6 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130

  4. Comparative Study of Multiplet Structures of Mn4+ in K2SiF6, K2GeF6, and K2TiF6 Based on First-Principles Configuration-Interaction Calculations

    Science.gov (United States)

    Novita, Mega; Ogasawara, Kazuyoshi

    2012-02-01

    We performed first-principles configuration-interaction calculations of multiplet energies for Mn4+ in K2SiF6, K2GeF6, and K2TiF6 crystals. The results indicate that corrections based on a single-electron calculation are effective for the prediction of 4A2 → 4T2 and 4A2 → 4T1a transition energies, while such corrections are not necessary for the prediction of the 4A2 → 2E transition energy. The cluster size dependence of the multiplet energies is small. However, the 4A2 → 2E transition energy is slightly improved by using larger clusters including K ions. The theoretical multiplet energies are improved further by considering the lattice relaxation effect. As a result, the characteristic multiplet energy shifts depending on the host crystal are well reproduced without using any empirical parameters. Although K2GeF6 and K2TiF6 have lower symmetry than K2SiF6, the results indicate that the variation of the multiplet energy is mainly determined by the Mn-F bond length.

  5. Systematic differences in electrochemical reduction of the structurally characterized anti-cancer platinum(IV) complexes [Pt{((p-HC6F4)NCH2)2}-(pyridine)2Cl2], [Pt{((p-HC6F4)NCH2)2}(pyridine)2(OH)2], and [Pt{((p-HC6F4)NCH2)2}(pyridine)2(OH)Cl].

    Science.gov (United States)

    Guo, Si-Xuan; Mason, Dayna N; Turland, Susan A; Lawrenz, Eric T; Kelly, Lance C; Fallon, Gary D; Gatehouse, Bryan M; Bond, Alan M; Deacon, Glen B; Battle, Andrew R; Hambley, Trevor W; Rainone, Silvina; Webster, Lorraine K; Cullinane, Carleen

    2012-10-01

    The putative platinum(IV) anticancer drugs, [Pt{((R)NCH(2))(2)}(py)(2)XY] (X,Y=Cl, R=p-HC(6)F(4) (1a), C(6)F(5) (1b); X,Y=OH, R=p-HC(6)F(4) (2); X=Cl, Y=OH, R=p-HC(6)F(4) (3), py = pyridine) have been prepared by oxidation of the Pt(II) anticancer drugs [Pt{((R)NCH(2))(2)}(py)(2)] (R=p-HC(6)F(4) (4a) or C(6)F(5) (4b)) with PhICl(2) (1a,b), H(2)O(2) (2) and PhICl(2)/Bu(4)NOH (3). NMR spectroscopy and the X-ray crystal structures of 1b, 2 and 3 show that they have octahedral stereochemistry with the X,Y ligands in the trans-position. The net two electron electrochemical reduction of 1a, 2 and 3 has been studied by voltammetric, spectroelectrochemical and bulk electrolysis techniques in acetonitrile. NMR and other data reveal that reduction of 1a gives pure 4a via the elimination of both axial chloride ligands. In the case of 2, one end of the diamide ligand is protonated and the resulting -NH(p-HC(6)F(4)) group dissociated giving a [Pt{N(p-HC(6)F(4))CH(2)CH(2)NH(p-HC(6)F(4))}] arrangement, one pyridine ligand is lost and a hydroxide ion retained in the coordination sphere. Intriguingly, in the case of reduction of 3, a 50% mixture of the reduction products of pure 1a and 2 is formed. The relative ease of reduction is 1>3>2. Testing of 1a, 2 and 3 against L1210 and L1210(DDP) (DDP = cis-diamine-dichloroplatinum(II)) mouse leukaemia cells shows all to be cytotoxic with IC(50) values of 1.0-3.5 μM. 2 and 3 are active in vivo against AHDJ/PC6 tumor line when delivered in peanut oil despite being hard to reduce electrochemically, and notably are more active than 4a delivered in this medium whilst comparable with 4a delivered in saline/Tween. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. F6H8 as an Intraoperative Tool and F6H8/Silicone Oil as a Postoperative Tamponade in Inferior Retinal Detachment with Inferior PVR.

    Science.gov (United States)

    Tosi, Gian Marco; Marigliani, Davide; Bacci, Tommaso; Romeo, Napoleone; Balestrazzi, Angelo; Martone, Gianluca; Caporossi, Tomaso

    2014-01-01

    Purpose. To evaluate the effectiveness and safety of perfluorohexyloctane (F6H8) for intraoperative flattening of the retina and of F6H8/silicone oil (SO) 1000 cSt as a postoperative tamponade for inferior retinal detachment with inferior proliferative vitreoretinopathy. Methods. This is a retrospective review of 22 patients who underwent pars plana vitrectomy using F6H8 as an intraoperative tool to flatten the retina. At the end of the surgery a direct partial exchange between F6H8 and SO 1000 cSt was performed, tamponing the eye with different ratios of F6H8/SO (70/30, 60/40, 50/50, 40/30, and 30/70). Anatomical and functional results and complications were evaluated over the follow-up period (mean 22.63 months). Results. F6H8 was efficacious for intraoperative flattening of the retina. Twenty-one of the 22 patients achieved a complete retinal reattachment. Postoperative visual acuity (VA) ranged from light perception to 20/70, with 72% of patients obtaining VA better than 20/400. No emulsification/inflammation was observed whatever the ratio of F6H8/SO used. With higher ratios of F6H8/SO (70/30 and 60/40) cloudiness of the tamponade was observed. A transparent mixture was present with all the other ratios. Conclusions. The surgical technique adopted is very simple and safe. The optimal F6H8/SO ratio seems to be between 50/50 and 30/70.

  7. F6H8 as an Intraoperative Tool and F6H8/Silicone Oil as a Postoperative Tamponade in Inferior Retinal Detachment with Inferior PVR

    Directory of Open Access Journals (Sweden)

    Gian Marco Tosi

    2014-01-01

    Full Text Available Purpose. To evaluate the effectiveness and safety of perfluorohexyloctane (F6H8 for intraoperative flattening of the retina and of F6H8/silicone oil (SO 1000 cSt as a postoperative tamponade for inferior retinal detachment with inferior proliferative vitreoretinopathy. Methods. This is a retrospective review of 22 patients who underwent pars plana vitrectomy using F6H8 as an intraoperative tool to flatten the retina. At the end of the surgery a direct partial exchange between F6H8 and SO 1000 cSt was performed, tamponing the eye with different ratios of F6H8/SO (70/30, 60/40, 50/50, 40/30, and 30/70. Anatomical and functional results and complications were evaluated over the follow-up period (mean 22.63 months. Results. F6H8 was efficacious for intraoperative flattening of the retina. Twenty-one of the 22 patients achieved a complete retinal reattachment. Postoperative visual acuity (VA ranged from light perception to 20/70, with 72% of patients obtaining VA better than 20/400. No emulsification/inflammation was observed whatever the ratio of F6H8/SO used. With higher ratios of F6H8/SO (70/30 and 60/40 cloudiness of the tamponade was observed. A transparent mixture was present with all the other ratios. Conclusions. The surgical technique adopted is very simple and safe. The optimal F6H8/SO ratio seems to be between 50/50 and 30/70.

  8. F6H8 as an Intraoperative Tool and F6H8/Silicone Oil as a Postoperative Tamponade in Inferior Retinal Detachment with Inferior PVR

    Science.gov (United States)

    Tosi, Gian Marco; Bacci, Tommaso; Romeo, Napoleone; Balestrazzi, Angelo; Martone, Gianluca; Caporossi, Tomaso

    2014-01-01

    Purpose. To evaluate the effectiveness and safety of perfluorohexyloctane (F6H8) for intraoperative flattening of the retina and of F6H8/silicone oil (SO) 1000 cSt as a postoperative tamponade for inferior retinal detachment with inferior proliferative vitreoretinopathy. Methods. This is a retrospective review of 22 patients who underwent pars plana vitrectomy using F6H8 as an intraoperative tool to flatten the retina. At the end of the surgery a direct partial exchange between F6H8 and SO 1000 cSt was performed, tamponing the eye with different ratios of F6H8/SO (70/30, 60/40, 50/50, 40/30, and 30/70). Anatomical and functional results and complications were evaluated over the follow-up period (mean 22.63 months). Results. F6H8 was efficacious for intraoperative flattening of the retina. Twenty-one of the 22 patients achieved a complete retinal reattachment. Postoperative visual acuity (VA) ranged from light perception to 20/70, with 72% of patients obtaining VA better than 20/400. No emulsification/inflammation was observed whatever the ratio of F6H8/SO used. With higher ratios of F6H8/SO (70/30 and 60/40) cloudiness of the tamponade was observed. A transparent mixture was present with all the other ratios. Conclusions. The surgical technique adopted is very simple and safe. The optimal F6H8/SO ratio seems to be between 50/50 and 30/70. PMID:24672710

  9. Refined localization of the Escherichia coli F4ab/F4ac receptor locus on pig chromosome 13

    DEFF Research Database (Denmark)

    Joller, D.; Jørgensen, Claus Bøttcher; Bertschinger, H.U.

    2009-01-01

    Diarrhoea in newborn and weaned pigs caused by enterotoxigenic Escherichia coli (ETEC) expressing F4 fimbriae leads to considerable losses in pig production. In this study, we refined the mapping of the receptor locus for ETEC F4ab/F4ac adhesion (F4bcR) by joint analysis of Nordic and Swiss data....

  10. The receptor locus for escherichia coli F4ab/F4ac in the pig maps distal to the MUC4-LMLN region

    DEFF Research Database (Denmark)

    Rampoldi, Antonio; Jacobsen, Mette Juul; Bertschinger, Hans U.

    2011-01-01

    antigenic variants, F4ab, F4ac, and F4ad, of which F4ac is the most common. Resistance to ETEC F4ab/F4ac adhesion in pigs has been shown to be inherited as an autosomal recessive trait. In previous studies the ETEC F4ab/F4ac receptor locus (F4bcR) was mapped to the q41 region on pig chromosome 13......-generation pedigree including 45 offspring was generated with the aim to use this recombination event to refine the localization of the F4bcR locus. All pigs were phenotyped using the microscopic adhesion test and genotyped for a total of 59 markers. The recombination event was mapped to a 220-kb region between...

  11. Electrical conductivity of (Na3AlF6-40%K3AlF6)-AlF3-Al2O3 melts

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The effects of contents of AlF3 and Al2O3,and temperature on electrical conductivity of (Na3AlF6-40%K3AlF6)-AlF3-Al2O3 were studied by continuously varying cell constant (CVCC) technique.The results show that the conductivities of melts increase with the increase of temperature,but by different extents.Every increasing 10 ℃ results in an increase of 1.85×10-2,1.86×10-2,1.89×10-2 and 2.20×10-2 S/cm in conductivity for the (Na3AlF6-40%K3AlF6)-AlF3 melts containing 0%,20%,24%,and 30% AlF3,respectively.An increase of every 10 ℃ in temperature results an increase about 1.89×10-2,1.94×10-2,1.95×10-2,1.99×10-2 and 2.10×10-2 S/cm for (Na3AlF6-40%K3AlF6)-AlF3-Al2O3 melts containing 0%,1%,2%,3% and 4% A12O3,respectively.The activation energy of conductance was calculated based on Arrhenius equation.Every increasing 1% of AlF3 results in a decrease of 0.019 and 0.020 S/cm in conductivity for (Na3AlF6-40%K3AlF6)-AIF3 melts at 900 and 1 000 ℃,respectively.Every increase of 1% Al2O3 results in a decrease of 0.07 S/cm in conductivity for (Na3AlF6-40%K3AlF6)-AlF3-Al2O3 melts.The activation energy of conductance increases with the increase in content of AlF3 and Al2O3.

  12. Synthesis and Magnetic Properties of the Novel Dithiadiazolyl Radical, p-NCC6F4C6F4CNSSN

    Directory of Open Access Journals (Sweden)

    Jeremy M. Rawson

    2004-08-01

    Full Text Available The dithiadiazolyl radical p-NCC6F4C6F4CNSSN• (4 retains its monomericnature in the solid state with molecules linked together into chains via supramolecularCN···S interactions. Variable temperature magnetic studies on 4 show that it behaves as anear-ideal Curie paramagnet (|θ| less than 0.1 K, indicating negligible intermolecularexchange. The effective magnetic moment (1.78 μB is temperature independent and inexcellent agreement with the value expected for an S = 1⁄2 paramagnet with g = 2.01(1.74μB. The lack of exchange coupling between radicals is attributed to the absence ofsignificant orbital overlap between radical centres.

  13. On isoelectronic fluorides [H 3tren]ṡ(AlF 6)ṡH 2O, [H 3tren]ṡ(AlF 6)ṡHF, [H 4tren]ṡ(AlF 6)ṡ(F) and the iron analogue [H 4tren]ṡ(FeF 6)ṡ(F)

    Science.gov (United States)

    Adil, K.; Ben Ali, A.; Leblanc, M.; Maisonneuve, V.

    2006-06-01

    [H 3tren]ṡ(AlF 6)ṡH 2O, [H 3tren]ṡ(AlF 6)ṡHF and [H 4tren]ṡ( MF 6)ṡ(F) ( M=Al, Fe), are obtained by hydrothermal technique and microwave heating in the (Al(OH) 3,FeF 3)- tren-(HF/H 2O)-ethanol system. Structure determinations are performed from single crystal X-ray diffraction data. All phases are built up from ( MF 6) 3- anions linked by hydrogen bonds to [H 3tren] 3+ or [H 4tren] 4+ cations and to water or HF molecules or "isolated" fluoride anions. [H 3tren] 3+ and [H 4tren] 4+ cations adopt a "spider" shape configuration. Surprisingly, the HF molecule is strongly hydrogen bonded with one fluoride ion of the AlF 6 octahedron (d=2.38 Å) in [H 3tren]ṡ(AlF 6)ṡHF while "isolated" fluoride ion is weakly coordinated by three hydrogen atoms in [H 4tren]ṡ( MF 6)ṡ(F). The evolution of the formulations, from [H 3tren]ṡ(AlF 6)ṡH 2O to [H 3tren]ṡ(AlF 6)ṡHF and to [H 4tren]ṡ( MF 6)ṡ(F) ( M=Al, Fe), is linked with the increase of the HF content of the starting solution. The volumes per formula unit decrease from 321.3(1) Å 3 and 320.6(1) Å 3 in [H 3tren]ṡ(AlF 6)ṡH 2O and [H 3tren]ṡ(AlF 6)ṡHF, respectively, to 298.5(4) Å 3 in [H 4tren]ṡ(AlF 6)ṡ(F).

  14. A potential oncogenic role of the commonly observed E2F5 overexpression in hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Yuzhu Jiang; Seon-Hee Yim; Hai-Dong Xu; Seung-Hyun Jung; So Young Yang; Hae-Jin Hu; Chan-Kwon Jung; Yeun-Jun Chung

    2011-01-01

    AIM: To explore the expression pattern of E2F5 in primary hepatocellular carcinomas (HCCs) and elucidate the roles of E2F5 in hepatocarcinogenesis. METHODS: E2F5 expression was analyzed in 120 primary HCCs and 29 normal liver tissues by immunohistochemistry analysis. E2F5-small interfering RNA was transfected into HepG2, an E2F5-overexpressed HCC cell line. After E2F5 knockdown, cell growth capacity and migrating potential were examined. RESULTS: E2F5 was significantly overexpressed in primary HCCs compared with normal liver tissues (P = 0.008). The E2F5-silenced cells showed significantly reduced proliferation (P = 0.004). On the colony formation and soft agar assays, the number of colonies was significantly reduced in E2F5-silenced cells (P = 0.004 and P = 0.009, respectively). E2F5 knockdown resulted in the accumulation of G0/G1 phase cells and a reduction of S phase cells. The number of migrating/invading cells was also reduced after E2F5 knockdown (P = 0.021). CONCLUSION: To our knowledge, this is the first evidence that E2F5 is commonly overexpressed in primary HCC and that E2F5 knockdown significantly repressed the growth of HCC cells.

  15. Laser performance and optical properties of LiSrGaF6:Cr(3+)

    Science.gov (United States)

    Payne, Stephen A.; Chase, L. L.; Smith, Larry K.; Kway, Wayne L.; Chai, Bruce H. T.

    The laser pumped laser performance of the new material LiSrGaF6:Cr(3+) had been characterized. The laser results indicate that the material operated with a high slope efficiency of 50 pct. due to the low passive, and pump-induced, loss levels. The optical and laser properties of Cr(3+) doped LiSrGaF6 are similar to those of the LiSrAlF6 host previously investigated, although the magnitude of the expansion coefficients of the gallium analog are more favorable.

  16. Higgs Mass Triviality Bounds on F(4) Lattices

    Science.gov (United States)

    Klomfass, Markus

    In order to accurately describe the cutoff dependence of the Higgs mass triviality bound, the varphi ^4 theory is formulated on an F_4 lattice which preserves Lorentz invariance to a higher degree than the commonly used hypercubic lattice. We solve this model non-perturbatively by evaluating the linked cluster expansion through 12th order following the approach of Luscher and Weisz. The results are continued across the transition line into the broken phase by integrating the perturbative renormalization group equations. In the Goldstone phase, the renormalized coupling never exceeds 2/3 of the tree level unitarity bound when Lambda /m_{R}>= 2. Our results confirm recent Monte Carlo data and we obtain as an upper bound for the Higgs mass m_{R }/f_pi=2.45(7) at Lambda/m_{R }=2. Attempting to produce a heavier Higgs on the lattice, additional four-derivative terms are introduced in the naive action which serve to parameterize the leading order cutoff effects. Using a cluster reflection algorithm of the Swendsen-Wang-Wolff type, we simulate this action on an F_4 lattice in a region where the region where the effects of the new terms are expected to be maximal. As an upper bound we now obtain M _sigma/f_pi~ 2.8, an increase of about 20% compared to the simplest non-linear action. Despite triviality, the scalar sector may thus not be weakly interacting.

  17. DRMS Co-design by F4MS

    Directory of Open Access Journals (Sweden)

    Aissam Berrahou

    2010-03-01

    Full Text Available In this paper, we present Digital Rights Management systems (DRMS which are becoming more and more complex due to technology revolution in relation with telecommunication networks, multimedia applications and the reading equipments (Mobile Phone, IPhone, PDA, DVD Player,... The complexity of the DRMS, involves the use of new tools and methodologies that support software components and hardware components coupled design. The traditional systems design approach has been somewhat hardware first in that the software components are designed after the hardware has been designed and prototyped. This leaves little flexibility in evaluating different design options and hardware-software mappings. The key of codesign is to avoid isolation between hardware and software designs to proceed in parallel, with feedback and interaction between the two as the design progresses, in order to achieve high quality designs with a reduced design time. In this paper, we present the F4MS (Framework for Mixed Systems which is a unified framework for software and hardware design environment, simulation and aided execution of mixed systems. To illustrate this work we propose an implementation of DRMS business model based on F4MS framework.

  18. Data of evolutionary structure change: 1ANFA-3F5FA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1ANFA-3F5FA 1ANF 3F5F A A KIEEGKLVIWINGDKGYNGLAEVGKKFEKDTGIKVTVEH...TGKKSHLRKTTEKKLPTAATIAKLQQSEIWKMENEFYEFALEQFQFVRAHAVREKDGELYILAQNFFYEKIYPK...HHHHHHHHHHHHH EEEEE EEE EVID> 0 1ANF A 1ANFA 3.7251410484313965 EVID>EVID> 1 <

  19. Calculations of the vibrational frequency and isotopic shift of UF6 and U2F6

    Institute of Scientific and Technical Information of China (English)

    Zhang Yun-Guang; Zha Xin-Wei

    2012-01-01

    Molecular structure,vibrational frequency and infrared intensity of UF6 are investigated by using the revised Perdew-Burke-Enzerhof function with the triple-zeta polarized basis set.The calculation results are in good agreement with the experimental values and indicate the existence of a stable U2F6 molecule with a multiple bonded U2 unit.The calculation results also predict that the D3d symmetry of U2F6 is more stable than D3h.The optimized geometries,vibrational frequencies,and infrared intensities are also reported for U2F6 molecules in D3d symmetry.In addition,the isotopic shift of vibrational frequencies of the two molecules under isotopic substitution of uranium atom are also investigated with the same method.The U2F6 molecule is predicted to be better than UF6 for laser uranic isotope separation.

  20. 一种基于量化表修改的F5隐写方法%An F5 Steganographic Method Based on Quantization Table Modification

    Institute of Scientific and Technical Information of China (English)

    鲁国鹏; 叶学义; 汪云路; 张艳

    2012-01-01

    IQTM-F5方法在高嵌入比情况下,DCT系数直方图统计特性会被破坏.针对该问题,利用新的信息嵌入策略并结合IQTM-F5方法中采用的修改后量化表,提出一种保持DCT系数直方图统计特性的F5隐写方法.实验结果表明,该方法能够取得与IQTM-F5方法近似的信息隐藏容量和嵌入效率,隐秘图像具有更高的图像质量,并且抗直方图统计分析攻击的能力更强.%IQTM-F5 method may destroy Discrete Cosine Transform(DCT) coefficient histogram statistic characteristic at the time of high embedding rate. Aiming at the problem, this paper proposes a new F5 steganographic method using the same modified quantization table as that in IQTM-F5, but adopts different embedding strategy to preserve the DCT coefficient histogram statistic characteristic. Experimental results show that the proposed method achieves the same steganographic capacity and embedding efficiency as IQTM-F5, and obtains better stego-image quality and stronger resistibility to histogram statistical steganalysis.

  1. The Nuclear Orphan Receptor NR2F6 Is a Central Checkpoint for Cancer Immune Surveillance

    Directory of Open Access Journals (Sweden)

    Natascha Hermann-Kleiter

    2015-09-01

    Full Text Available Nuclear receptor subfamily 2, group F, member 6 (NR2F6 is an orphan member of the nuclear receptor superfamily. Here, we show that genetic ablation of Nr2f6 significantly improves survival in the murine transgenic TRAMP prostate cancer model. Furthermore, Nr2f6−/− mice spontaneously reject implanted tumors and develop host-protective immunological memory against tumor rechallenge. This is paralleled by increased frequencies of both CD4+ and CD8+ T cells and higher expression levels of interleukin 2 and interferon γ at the tumor site. Mechanistically, CD4+ and CD8+ T cell-intrinsic NR2F6 acts as a direct repressor of the NFAT/AP-1 complex on both the interleukin 2 and the interferon γ cytokine promoters, attenuating their transcriptional thresholds. Adoptive transfer of Nr2f6-deficient T cells into tumor-bearing immunocompetent mice is sufficient to delay tumor outgrowth. Altogether, this defines NR2F6 as an intracellular immune checkpoint in effector T cells, governing the amplitude of anti-cancer immunity.

  2. Optical properties of Mn3+ ions in Cs2NaAlF6 and Cs2NaGaF6 single crystals

    Science.gov (United States)

    da Fonseca, R. J. M.; Sosman, L. P.; Camara, A. R.

    2017-02-01

    The optical properties of Mn3+ ions in the elpasolites Cs2NaGaF6 and Cs2NaAlF6 have been investigated by absorption spectroscopy at 4.2 K. The absorption spectra are dominated by the spin-allowed 5E → 5T2 transition and the transition between the two Jahn-Teller components of the 5E level. The crystal-field parameter Dq was determined and a low crystal-field situation was established for both Mn3+-doped fluorides. The Jahn-Teller stabilization energies of the 5E and 5T2 levels were calculated and the obtained values shown a strong Jahn-Teller splitting in the 5E ground state.

  3. The magnetic properties of multiferroic BaCoF4

    Directory of Open Access Journals (Sweden)

    Shuang Zhou

    2017-05-01

    Full Text Available Multiferroic barium cobalt fluoride, BaCoF4, has been prepared by hydrothermal method. The antiferromagnetic structure has been confirmed, and the possible weak ferromagnetism due to Dzyaloshinskii-Moriya interaction has been excluded, from the straight line shape of applied magnetic field dependent magnetization (M-H curve without hysteresis loop at low temperature down to 5 K. After cooling under a magnetic field, conspicuous exchange bias effect was observed at low temperature of T<50 K, which was attributed to the exchange coupling between the two phases of different spin configuration. Furthermore, significant magnetodielectric effect was observed at room temperature, which has been interpreted to the magnetic field modified weak interaction between different layers.

  4. DRMS Co-design by F4MS

    CERN Document Server

    Berrahou, Aissam; Eleuldj, Mohsine

    2010-01-01

    In this paper, we present Digital Rights Management systems (DRMS) which are becoming more and more complex due to technology revolution in relation with telecommunication networks, multimedia applications and the reading equipments (Mobile Phone, IPhone, PDA, DVD Player,..). The complexity of the DRMS, involves the use of new tools and methodologies that support software components and hardware components coupled design. The traditional systems design approach has been somewhat hardware first in that the software components are designed after the hardware has been designed and prototyped. This leaves little flexibility in evaluating different design options and hardware-software mappings. The key of codesign is to avoid isolation between hardware and software designs to proceed in parallel, with feedback and interaction between the two as the design progresses, in order to achieve high quality designs with a reduced design time. In this paper, we present the F4MS (Framework for Mixed Systems) which is a unif...

  5. Spectroscopic analysis of LiTmF4

    DEFF Research Database (Denmark)

    Christensen, H.P.

    1979-01-01

    The absorption spectra of Tm3+ in LiTmF4 have been measured at 2, 10, 30, and 50 K in the spectral interval 4000-25 000 cm-1. The energy levels of the ground-state configuration were calculated by diagonalizing the Hamiltonian of the electron-electron interaction, the spin-orbit coupling...... effects, it was necessary after optimizing F2 and ζ to match the centers of gravity for the multiplets before the final adjustment of the B parameters. When this was done, the standard deviation was lowered from 170 to 12 cm-1. The B parameters obtained for Tm3+ have been compared to those of Tb3+, Ho3...

  6. Cu2+ in layered compounds: origin of the compressed geometry in the model system K2ZnF4:Cu2+.

    Science.gov (United States)

    Aramburu, J A; García-Lastra, J M; García-Fernández, P; Barriuso, M T; Moreno, M

    2013-06-17

    Many relevant properties (including superconductivity and colossal magnetoresistance) of layered materials containing Cu(2+), Ag(2+), or Mn(3+) ions are commonly related to the Jahn-Teller instability. Along this line, the properties of the CuF6(4-) complex in the K2ZnF4 layered perovskite have recently been analyzed using a parametrized Jahn-Teller model with an imposed strain [Reinen, D. Inorg. Chem.2012, 51, 4458]. Here, we present results of ab initio periodic supercell and cluster calculations on K2ZnF4:Cu(2+), showing unequivocally that the actual origin of the unusual compressed geometry of the CuF6(4-) complex along the crystal c axis in that tetragonal lattice is due to the presence of an electric field due to the crystal surrounding the impurity. Our calculations closely reproduce the experimental optical spectrum. The calculated values of the equilibrium equatorial and axial Cu(2+)-F(-) distances are, respectively, R(ax) = 193 pm and R(eq) = 204 pm, and so the calculated distortion R(ax) - R(eq) = 11 pm is three times smaller than the estimated through the parametrized Jahn-Teller model. As a salient feature, we find that if the CuF6(4-) complex would assume a perfect octahedral geometry (R(ax) = R(eq) = 203 pm) the antibonding a(1g)*(∼3z(2) - r(2)) orbital is placed above b(1g)*(∼x(2) - y(2)) with a transition energy E((2)A(1g) → (2)B(1g)) = 0.34 eV. This surprising fact stresses that about half the experimental value E((2)A(1g) → (2)B(1g)) = 0.70 eV is not due to the small shortening of the axial Cu(2+)-F(-) distance, but it comes from the electric field, E(R)(r), created by the rest of the lattice ions on the CuF6(4-) complex. This internal field, displaying tetragonal symmetry, is thus responsible for the compressed geometry in K2ZnF4:Cu(2+) and the lack of symmetry breaking behind the ligand relaxation. Moreover, we show that the electronic energy gain in this process comes from bonding orbitals and not from antibonding ones. The present

  7. Synthesis and structural characterization of C(OTeF5)4 and a comparative structural study of the isoelectronic B(OTeF5)4- anion.

    Science.gov (United States)

    Moran, Matthew D; Mercier, Hélène P A; Schrobilgen, Gary J

    2007-06-11

    Tetrakis(pentafluoroorthotellurate)carbon(IV), C(OTeF5)4, was synthesized by reaction of CBr4 with BrOTeF5 in SO2ClF solution at -78 degrees C and was isolated as a colorless, crystalline solid that is room-temperature stable in SO2ClF and in the solid state. Both natural abundance and 99% 13C-enriched C(OTeF5)4 have been characterized in SO2ClF solution by 13C, 19F, and 125Te NMR spectroscopy. In contrast, C(OTeF5)4 undergoes rapid decomposition to O(TeF5)2 and CO2 in CH3CN at 10 degrees C but is stable at -40 degrees C. The X-ray crystal structures of C(OTeF5)4 and [N(CH3)4][B(OTeF5)4] were determined at -30 and -170 degrees C, respectively. The averages of four smaller C/B-O-Te bond angles and O...O contacts and two larger C/B-O-Te bond angles and O...O contacts of C(OTeF5)4 and the isoelectronic B(OTeF5)4- anion are consistent with local S4 symmetry, as predicted by ligand close packing considerations. The existence of three sets of Te-O-C/B-O torsion angles and the energy-minimized geometries of C(OTeF5)4 and B(OTeF5)4- also confirm their local S4 symmetries. The low-temperature, solid-state Raman spectra of 12/13C(OTeF5)4 and B(OTeF5)4- were assigned and compared. The energy-minimized geometries, vibrational frequencies, natural charges, and natural bond orders of both species have been calculated using density functional theory methods. The calculated geometries are in accord with the S4 symmetries assigned for the experimental structures.

  8. SCP06F6: A carbon-rich extragalactic transient at redshift z~0.14

    CERN Document Server

    Gänsicke, B T; Marsh, T R; Wheatley, P J

    2008-01-01

    We show that the spectrum of the unusual transient SCP06F6 is consistent with emission from a cool, carbon-rich atmosphere at a redshift of z~0.14. The extragalactic nature of the transient rules out novae, shell flashes, and V838 Mon-like events as cause of the observed brightening. The distance to SCP 06F6 implies a peak magnitude of M_I~-18, in the regime of supernovae. The morphology of the light curve of SCP 06F6 around the peak in brightness resembles the slowly evolving TypeII supernovae SN 1994Y and SN 2006 gy. We further report the detection of an X-ray source co-incident with SCP 06F6 in a target of opportunity XMM-Newton observation made during the declining phase of the transient. The X-ray luminosity of L_X~(5+-1)x10^42 erg/s is two orders of magnitude higher than observed to date from supernovae. If related to a supernova event, SCP 06F6 would define a new class. An alternative, though less likely, scenario is the tidal disruption of a carbon-rich star.

  9. File list: Oth.ALL.05.C34F6PERIOD9.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.05.C34F6PERIOD9.AllCell ce10 TFs and others C34F6.9 All cell types SRX33107...6,SRX331074 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/assembled/Oth.ALL.05.C34F6PERIOD9.AllCell.bed ...

  10. File list: Oth.ALL.50.C34F6PERIOD9.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.50.C34F6PERIOD9.AllCell ce10 TFs and others C34F6.9 All cell types SRX33107...6,SRX331074 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/assembled/Oth.ALL.50.C34F6PERIOD9.AllCell.bed ...

  11. File list: Oth.ALL.20.C34F6PERIOD9.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.20.C34F6PERIOD9.AllCell ce10 TFs and others C34F6.9 All cell types SRX33107...6,SRX331074 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/assembled/Oth.ALL.20.C34F6PERIOD9.AllCell.bed ...

  12. File list: Oth.ALL.10.C34F6PERIOD9.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.10.C34F6PERIOD9.AllCell ce10 TFs and others C34F6.9 All cell types SRX33107...6,SRX331074 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/assembled/Oth.ALL.10.C34F6PERIOD9.AllCell.bed ...

  13. The F(4) gauged supergravity in six dimensions

    Science.gov (United States)

    Romans, L. J.

    1986-06-01

    Gauged N = 4 supergravity theories with Yang-Mills symmetry SU(2) are constructed in six dimensions. There are four distinct theories, determined by the values of the SU(2) coupling constant g and a mass parameter m for the two-index tensor field contained in the theories. One of the theories has a scalar potential with two extrema; one extremum leads to a ground state exhibiting the full anti-de Sitter supersymmetry F(4), while the other breaks the supersymmetry completely. In this theory, and also in two of the remaining three theories, the two-index tensor "eats" an abelian vector and becomes massive, acquiring a cubic self-coupling in the process. The last theory, in which the tensor field remains massless, coincides with one previously obtained by dimensional reduction from seven dimensions. We obtain a variety of compactifications for all the theories, many supersymmetric and many to four dimensions. Finally, we comment on the geometrical structure of the theories, and compare them to ten-dimensional supergravities.

  14. Synthesis and Near-infrared Luminescent Properties of NaGdF4:Nd3+@NaGdF4 Core/Shell Nanocrystals with Different Shell Thickness.

    Science.gov (United States)

    Li, Xinke; You, Fangtian; Peng, Hongshang; Huang, Shihua

    2016-04-01

    The near-infrared to near-infrared (NIR-to-NIR) photoluminescence of nanocrystals has outstanding advantages in biological imaging. NaGdF4:Nd3+ core nanocrystals and NaGdF4:Nd3+@NaGdF4 core/shell nanocrystals with different shell thicknesses were synthesized by a simple solvothermal method. The obtained nanocrystals were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. The phase of all nanocrystals is hexagonal. NaGdF4:Nd3+ core nanocrystals have an average size of 6 nm. By controlling core-shell ratio for 1:2 and 1:3, we obtained NaGdF4:Nd3+@NaGdF4 core/shell nanocrystals with average sizes of 10 nm and 11 nm, respectively. When excited at 808 nm, strong NIR emission was observed. The emission peaks at -860 nm, -1060 nm and -1330 nm correspond to the transitions from the 4F3/2 state to the 4I9/2, 4I1/2 and 4I13/2 state of Nd3+ ions, respectively. The emission intensity of NaGdF4:Nd3+@NaGdF4 core/shell nanocrystals is stronger than that of the core. The intensity increases with the increase of shell thickness. The shell improves the luminous efficiency by reducing surface defects. The decay time of Nd3+ emission in NaGdF4:Nd3+@NaGdF4 core/shell nanocrystal is longer than that in NaGdF4:Nd3+ core, indicating that the shell isolates effectively the emitting ions (Nd3+) from the quenching defects. With the increase of shell thickness, the decay time becomes longer. Within a certain range of shell thickness, thicker shell can protect the emitting Nd3+ ions on the surface of core nanocrystals more effectively.

  15. DLR-F6翼身组合体数值计算%Drag prediction of DLR-F6 using MFlow unstructured mesh solver

    Institute of Scientific and Technical Information of China (English)

    张耀冰; 邓有奇; 吴晓军; 孟凡菊

    2011-01-01

    Drag predictions of the DLR-F6 wing-body, with and without the FX2B fairing from the 3rd AIAA drag prediction workshop, are made using the self-made unstructured grid solver MFlow. The focus of this study are grid convergence characteristics, drag polars, and pressure distribution for the two configurations. The comparison is made between our result and the result from drag prediction workshop. The influence of flow separtion in the wing-fuselage junctions using different grids is detailed discussed. Throughout this result, the precision of our MFlow for drag prediction is similar to the CFD software, such as TAU, TAS, and USM3 D, and it can be applied to drag prediction.%使用自行研制的混合网格亚跨超声速流场解算器程序MFlow计算了AIAA第三届阻力会议提供的DLR-F6及其带整流装置FX2B情况下的阻力.重点分析了两者的网格收敛特性、阻力极曲线以及压力分布等,并与阻力会议的各个软件的计算结果进行比较.详细分析了DLR-F6翼身结合处后缘附近网格精度对分离气泡计算的影响.计算结果表明,MFlow程序的计算精度与国外软件相近,能够为阻力计算提供比较精确的结果.

  16. LiCaAlF6:Cr(3+) - A promising new solid-state laser material

    Science.gov (United States)

    Payne, Stephen A.; Chase, L. L.; Newkirk, Herbert W.; Smith, Larry K.; Krupke, William F.

    1988-11-01

    LiCaAlF6:Cr(3+) (Cr3+:LiCAF) exhibits an intrinsic (extrapolated maximum) slope efficiency of 67 percent. For comparison, the intrinsic slope efficiencies of BeAl2O4:Cr(3+) (alexandrite), Na3Ga2Li3F12:Cr(3+), and ScBO3:3+ were found to 65, 28, and 26 percent, respectively. The tuning range of LiCaAlF6:Cr(3+) was determined to be at least 720-840 nm. The conventional spectroscopic properties, such as the absorption, emission, and emission lifetimes as a function of temperature, are reported as well.

  17. Control of metal-insulator transition in (EDO-TTF)2SbF6

    Science.gov (United States)

    Maesato, Mitsuhiko; Nakano, Yoshiaki; Shao, Xiangfeng; Yoshida, Yukihiro; Yamochi, Hideki; Saito, Gunzi; Moreac, Alain; Ameline, Jean-Claude; Collet, Eric; Uruichi, Mikio; Yakushi, Kyuya

    2009-02-01

    We have examined the temperature dependence of optical reflectance spectra of (EDO-TTF)2SbF6 salt, and succeeded to detect the thermal hysteresis by the reflectance spectra. In order to investigate high pressure effects on the metal-insulator transition of SbF6 salt, we have performed Raman experiments under pressures up to 6 kbar. Drastic changes in the frequencies of charge sensitive C=C stretching modes suggested the pressure-induced reentrant metal-insulator-metal transition at room temperature.

  18. Ion mobility, conductivity, structure, and phase transitions in K0.7M0.3SbF4 compounds with M=Rb, NH4

    Science.gov (United States)

    Kavun, V. Ya.; Gerasimenko, A. V.; Uvarov, N. F.; Polyantsev, M. M.; Zemnukhova, L. A.

    2016-09-01

    Ion mobility, phase transitions, structure, and conductivity in the K0.7M0.3SbF4 (M=Rb, NH4) compounds were studied by NMR spectroscopy, DSC, X-ray, and conductivity measurements. The predominant form in the ion motions resulting from the phase transition of high modification was diffusion of fluoride and ammonium ions above 450 K. The high-temperature phases of K0.7M0.3SbF4 (M=Rb, NH4) are superionic, while their conductivity attains the values of ~10-2-10-4 S/cm at 450-500 K. The structures of α- and β-modifications of the K0.7Rb0.3SbF4 are monoclinic (space group P21/m). The main structural units in them are statistically substituting each other K+ and Rb+ cations and complex 1[ SbF4 ]- ∞ anions linked into zigzag-like chains by bridge fluorine atoms. The nearest surrounding of each antimony atom contains five fluorine atoms, so that the antimony coordination polyhedron can be described, taking into account the lone electron pair, as a distorted SbF5E octahedron (ψ-octahedron).

  19. Proton and Gamma Radiation Effects in Undoped, Single-doped and co-doped YLiF4 and LuLiF4

    Science.gov (United States)

    Lee, Hyung; Bai, Yingxin; Yu, Kirong; Singh, U.

    2009-01-01

    Proton and gamma radiation effects in various YLiF4 and LuLiF4 crystals have been investigated. The radiation induced color centers compared with six different kinds of crystal samples in ranges up to 200 krads and 200 MeV. The radiation induced absorption coefficients are strongly dependent on polarization and concentration of rare-earth ions.

  20. Clinical and molecular characterizations of novel POU3F4 mutations reveal that DFN3 is due to null function of POU3F4 protein.

    NARCIS (Netherlands)

    Lee, H.K.; Song, M.H.; Kang, M.; Lee, J.T.; Kong, K.A.; Choi, S.J.; Lee, K.Y.; Venselaar, H.; Vriend, G.; Lee, W.S.; Park, H.J.; Kwon, T.K.; Bok, J.; Kim, U.K.

    2009-01-01

    X-linked deafness type 3 (DFN3), the most prevalent X-linked form of hereditary deafness, is caused by mutations in the POU3F4 locus, which encodes a member of the POU family of transcription factors. Despite numerous reports on clinical evaluations and genetic analyses describing novel POU3F4 mutat

  1. Drag of DLR-F6 Wing-Body Configuration%DLR-F6翼身组合体阻力计算

    Institute of Scientific and Technical Information of China (English)

    王运涛; 王光学; 张玉伦

    2008-01-01

    采用"亚跨超CFO软件平台"(TRIP2.0)数值模拟DLR-F6翼身组合体构型,采用的多块对接网格、测压和测力的试验结果均来自美国AIAA阻力计算小组,对比计算结果采用CFL3D的结果.详细研究网格密度、湍流模型对DLR-F6翼身组合体构型的总体气动特性和压力分布的影响,计算结果与相应的试验结果较一致.采用SST两方程模型得到网格收敛结果;不同的湍流模型对压差阻力影响较小,对摩擦阻力影响较大;不同的网格密度和湍流模型对压力分布影响较小.

  2. Progress in the material development of LiCaAlF(6):Cr(3+) laser crystals

    Science.gov (United States)

    Shinn, M. D.; Chase, L. L.; Caird, J. A.; Payne, S. A.; Atherton, L. J.; Kway, W. L.

    1990-03-01

    High Cr(3+) doping levels, up to 8 mole percent, and low losses were obtained with the tunable solid-state laser material LiCaAlF(6):Cr(3+) (Cr:LiCAF). Measurements and calculations show that high pumping and extraction efficiencies are possible with the improved material.

  3. Two-photon excitation spectra of Cr3 :K2NaScF6

    Science.gov (United States)

    Bartram, R. H.; Wein, G. R.; Hamilton, D. S.; Sliwczuk, U.; Rinzler, A. G.

    Two-photon excitation (TPE) spectra of Cr3+:K2NaScF6 exhibit unexpected features including a forbidden transition, extended progressions, a split zero-phonon line and anomalous polarization anisotropy. These features are explained by departures from standard approximations.

  4. Structure and ferroelasticity of tetramethylammonium-hexafluoroosmate(IV), (TMA)(2)[OsF6

    NARCIS (Netherlands)

    Kuppers, H; Gobel, O; Bruhn, C; Schmahl, WW

    2001-01-01

    (TMA)(2)[OsF6] has at room temperature a rhombohedral structure (space group R (3) over bar) which is pseudocubic (K-2[PtCl6]-type). a = 8.0565(6) Angstrom, r = 20.020(3) Angstrom (hexagonal setting). Double refraction decreases linearly with increasing temperature and disappears above 434 K which i

  5. Atmospheric chemistry of C2F5CHO: mechanism of the C2F5C(O)O-2+HO2 reaction

    DEFF Research Database (Denmark)

    Andersen, Mads Peter Sulbæk; Hurley, MD; Wallington, TJ;

    2003-01-01

    Smog chamber/FTIR techniques were used to study the gas-phase reaction of C2F5C(O) with HO2 radicals in 100-700 Torr of air, or O-2, diluent at 296 K. The reaction proceeds by two pathways leading to formation of C2F5C(O)OH and O-3 in ayield of 24 +/- 4% and C2F5C(O)O radicals, OH radicals and O-2...... in a yield of 76 +/- 4 The gas phase reaction of CnF2n+1C(O)O-2 with HO2 radicals offers a potential explanation for at least part of the observed environmental burden of fluorinated carboxylic acids, CnF2n+1C(O)OH. As part of this work an upper limit for the rate constant of reaction of Cl atorns with C2F5C(O)OH...... at 296 K was determined; k(Cl + C2F5C(O)OH)

  6. Recognition of membrane-bound fusion-peptide/MPER complexes by the HIV-1 neutralizing 2F5 antibody: implications for anti-2F5 immunogenicity.

    Directory of Open Access Journals (Sweden)

    Nerea Huarte

    Full Text Available The membrane proximal external region (MPER of the fusogenic HIV-1 glycoprotein-41 harbors the epitope sequence recognized by 2F5, a broadly neutralizing antibody isolated from an infected individual. Structural mimicry of the conserved MPER 2F5 epitope constitutes a pursued goal in the field of anti-HIV vaccine development. It has been proposed that 2F5 epitope folding into its native state is attained in the vicinity of the membrane interface and might involve interactions with other viral structures. Here we present results indicating that oligomeric complexes established between MPER and the conserved amino-terminal fusion peptide (FP can partition into lipid vesicles and be specifically bound by the 2F5 antibody at their surfaces. Cryo-transmission electron microscopy of liposomes doped with MPER:FP peptide mixtures provided the structural grounds for complex recognition by antibody at lipid bilayer surfaces. Supporting the immunogenicity of the membrane-bound complex, these MPER:FP peptide-vesicle formulations could trigger cross-reactive anti-MPER antibodies in rabbits. Thus, our observations suggest that contacts with N-terminal regions of gp41 may stabilize the 2F5 epitope as a membrane-surface antigen.

  7. Development and Efficacy Assessment of an Enteric Coated Porous Tablet Loaded With F4 Fimbriae for Oral Vaccination of Piglets against F4+ Escherichia coli Infections.

    Science.gov (United States)

    Srivastava, Atul; Gowda, D V; Madhunapantula, SubbaRao V; Siddaramaiah

    2016-01-01

    Enterotoxigenic Escherichia coli (ETEC) infection is one of the major causes contributing to the development of diarrhoea and mortality in new born, suckling and newly weaned piglets. To date, no preventive/treatment strategy showed promising results, which could be due to the lack of potent vaccines, and/or due to the development of resistance of ETEC to antibiotics. Therefore, in the present investigation, a novel porous sodium alginate (SA) tablet formulation loaded with F4 fimbriae antigen was developed and tested for efficacy against ETEC infections in piglet models. Precompression parameters of the powder mixes and post compression parameters of tablets have been evaluated and results were found to be satisfactory. Loading of F4 fimbrial antigens into the tablets was achieved by inducing pores in the tablets via the sublimation of camphor followed by incubation with purified F4 fimbriae. The loaded tablets have been coated with Eudragit L100 to protect the F4 fimbriae from (a) highly acidic gastric environment; (b) proteolytic cleavage by pepsin; and (c) to promote subsequent release in the intestine. Evaluation of developed F4 fimbrial tablets in a Pig model demonstrated induction of mucosal immunity, and a significant reduction of F4+ E. coli in faeces. Therefore, F4 fimbriae loaded porous tablets could be a novel oral vaccination candidate to induce mucosal and systemic immunity against ETEC infections.

  8. Crystal field splitting of the 4f 5d electronic configuration of Pr 3+ ions in wide band gap fluoride dielectric crystals

    Science.gov (United States)

    Sarantopoulou, E.; Kollia, Z.; Cefalas, A. C.; Semashko, V. V.; Yu. Abdulsabirov, R.; Naumov, A. K.; Korableva, S. L.; Szczurek, T.; Kobe, S.; McGuiness, P. J.

    2002-07-01

    The absorption and the laser-induced fluorescence spectra of Pr 3+ ion in YF 3, LaF 3, KY 3 F 10 and LiLuF 4, single crystal hosts were obtained in the vacuum ultraviolet region of the spectrum. The energy position and the spacing of the levels of the 4f 5d electronic configuration depend on the host matrix. In addition, strong vacuum ultraviolet emission bands were observed, following crystal excitation at 157 nm with the molecular fluorine laser. The emission bands were due to the interconfigurational 4 f 5 d→4 f2 dipole-allowed transitions in Pr 3+ ions, and they were assigned to the transitions between the edge of the lowest Stark component of the 4f 5d electronic configuration and the levels of the 4f 2 electronic configuration. The VUV spectra can be interpreted by applying the crystal field model, and taking into consideration that lanthanide contraction of the 4f n-1 5d electronic configurations of the rare earth ions, and shielding of the positive ion charge from the electrons in the 4f n electronic configuration is taking place. Finally, a new method for monitoring the concentration of the rare earth ions in wide band gap fluoride dielectric crystals in a non-destructive way, by measuring magnetic dipole moments with the vibrating sample magnetometer (VSM) method, is presented for the first time to our knowledge for this type of crystals.

  9. Absolute Generalized Oscillator Strength Profiles of Rydberg Transitions in C2F6

    Institute of Scientific and Technical Information of China (English)

    FAN Xiao-Wei(樊晓伟); LU Shan(卢杉); ZHANG Xian-Zhou(张现周); K.T.Leung

    2004-01-01

    Absolute generalized oscillator strengths (GOSs) for the two Rydberg excitations at 12.1 e V and 13.5 e V in C2 F6have been determined as functions of energy loss and momentum transfer (K) at impact energy of 2.5 keV. The GOS profiles for these two Rydberg transitions to 3 p Rydberg orbital have the characteristic dipole-dominated shapes with a strong maximum at K = 0.

  10. Measurement of the figure of merit M for 1-C3F6/SF6 mixtures

    DEFF Research Database (Denmark)

    Christensen, Jørn Erik Berril; McAllister, Iain Wilson

    1997-01-01

    High precision measurements of the linear part of the Paschen curve are reported for 1-C3F6/SF6 mixtures. From these measurements, values for the pressure-reduced limiting electric field strength (E/p)lim and the associated figure of merit M are derived. These two parameters can be used...... to characterise the insulating properties of a strongly electronegative gas or gas mixture. The present measurements confirm the existence of positive synergism....

  11. NR2F6 Expression Correlates with Pelvic Lymph Node Metastasis and Poor Prognosis in Early-Stage Cervical Cancer

    Directory of Open Access Journals (Sweden)

    Chunhao Niu

    2016-10-01

    Full Text Available Background: There is an abnormal expression of nuclear receptor subfamily 2 group F member 6 (NR2F6 in human cancers such as breast cancer, colon cancer, and acute myelogenous leukemia. However, its clinical significance in cervical cancer has not been established. We explored NR2F6 expression and its clinicopathological significance in early-stage cervical cancer. Methods: NR2F6 expression in cervical cancer cell lines and cervical cancer tissues was determined by Western blotting, real-time PCR, and immunochemistry (IHC. NR2F6 expression in 189 human early-stage cervical cancer tissue samples was evaluated using IHC. The relevance between NR2F6 expression and early-stage cervical cancer prognosis and clinicopathological features was determined. Results: There was marked NR2F6 mRNA and protein overexpression in the cervical cancer cells and clinical tissues compared with an immortalized squamous cell line and adjacent noncancerous cervical tissues, respectively. In the 189 cervical cancer samples, NR2F6 expression was positively related to International Federation of Gynecology and Obstetrics (FIGO stage (p = 0.006, squamous cell carcinoma antigen (p = 0.006, vital status (p < 0.001, tumor recurrence (p = 0.001, chemotherapy (p = 0.039, and lymph node metastasis (p < 0.001. Overall and disease-free survival was shorter in patients with early-stage cervical cancer and higher NR2F6 levels than in patients with lower levels of NR2F6. Univariate and multivariate analysis determined that NR2F6 was an independent prognostic factor of survival in early-stage cervical cancer. Conclusions: Taken together, our findings suggest that high NR2F6 expression predicts pelvic lymph node metastasis, tumor recurrence and poor prognosis in early-stage cervical cancer. NR2F6 might be a novel prognostic biomarker and potential therapeutic target of cervical cancer.

  12. A luminescence spectroscopy and theoretical study of 4f-5d transitions of Ce3+ ions in SrAlF5 crystals.

    Science.gov (United States)

    Omelkov, S I; Brik, M G; Kirm, M; Pustovarov, V A; Kiisk, V; Sildos, I; Lange, S; Lobanov, S I; Isaenko, L I

    2011-03-16

    This research is focused on the 4f-5d transitions in Ce(3+) centers doped into tetragonal β-SrAlF(5) single crystals belonging to the I4(1)/a space group. The presence of four non-equivalent Sr(2+) sites in this compound leads to the appearance of three spectroscopically non-equivalent Ce(3+) luminescence centers, which can be well distinguished using a time-resolved laser spectroscopy technique. All 4f-5d transitions have slightly varying excitation and emission energies with characteristic probabilities resulting in several decay times that can be determined experimentally. One of these centers experiences strong perturbation due to a defect nearby, probably the O(2-) impurity ion substituting for the F(-) ion and acting as a charge compensator as well. Identification of these photoluminescence centers is performed using crystal field calculations. The crystal field parameters are calculated for two identified centers using the structural data for SrAlF(5); diagonalization of the crystal field Hamiltonian results in obtaining the splitting of the Ce(3+) 5d states. This method allows 'regular' unperturbed Ce(3+) centers with selected Sr(2+) sites to be assigned.

  13. E2F6 Impairs Glycolysis and Activates BDH1 Expression Prior to Dilated Cardiomyopathy

    Science.gov (United States)

    Major, Jennifer L.; Dewan, Aaraf; Salih, Maysoon; Leddy, John J.; Tuana, Balwant S.

    2017-01-01

    Rationale The E2F pathway plays a critical role in cardiac growth and development, yet its role in cardiac metabolism remains to be defined. Metabolic changes play important roles in human heart failure and studies imply the ketogenic enzyme β-hydroxybutyrate dehydrogenase I (BDH1) is a potential biomarker. Objective To define the role of the E2F pathway in cardiac metabolism and dilated cardiomyopathy (DCM) with a focus on BDH1. Methods and Results We previously developed transgenic (Tg) mice expressing the transcriptional repressor, E2F6, to interfere with the E2F/Rb pathway in post-natal myocardium. These Tg mice present with an E2F6 dose dependent DCM and deregulated connexin-43 (CX-43) levels in myocardium. Using the Seahorse platform, a 22% decrease in glycolysis was noted in neonatal cardiomyocytes isolated from E2F6-Tg hearts. This was associated with a 39% reduction in the glucose transporter GLUT4 and 50% less activation of the regulator of glucose metabolism AKT2. The specific reduction of cyclin B1 (70%) in Tg myocardium implicates its importance in supporting glycolysis in the postnatal heart. No changes in cyclin D expression (known to regulate mitochondrial activity) were noted and lipid metabolism remained unchanged in neonatal cardiomyocytes from Tg hearts. However, E2F6 induced a 40-fold increase of the Bdh1 transcript and 890% increase in its protein levels in hearts from Tg pups implying a potential impact on ketolysis. By contrast, BDH1 expression is not activated until adulthood in normal myocardium. Neonatal cardiomyocytes from Wt hearts incubated with the ketone β-hydroxybutyrate (β-OHB) showed a 100% increase in CX-43 protein levels, implying a role for ketone signaling in gap junction biology. Neonatal cardiomyocyte cultures from Tg hearts exhibited enhanced levels of BDH1 and CX-43 and were not responsive to β-OHB. Conclusions The data reveal a novel role for the E2F pathway in regulating glycolysis in the developing myocardium

  14. Diastereoselective B(C6F5)3-Catalyzed Reductive Carbocyclization of Unsaturated Carbohydrates.

    Science.gov (United States)

    Bender, Trandon A; Dabrowski, Jennifer A; Zhong, Hongyu; Gagné, Michel R

    2016-08-19

    A B(C6F5)3-catalyzed method for the selective conversion of unsaturated carbohydrates to cyclopentanes and cyclopropanes is disclosed. Catalyst activation of tertiary silanes generates the ion pair [(C6F5)3B-H][ROSi2] whose components synergistically activate C-O bonds for diastereoselective C-C bond formation. Sila-THF cations are invoked as key intermediates facilitating carbocyclizations. Complex chiral synthons are thereby obtained in a single pot.

  15. Enhance the Er(3+) Upconversion Luminescence by Constructing NaGdF4:Er(3+)@NaGdF4:Er(3+) Active-Core/Active-Shell Nanocrystals.

    Science.gov (United States)

    Du, Xiaoyu; Wang, Xiangfu; Meng, Lan; Bu, Yanyan; Yan, Xiaohong

    2017-12-01

    NaGdF4:12%Er(3+)@NaGdF4:x%Er(3+) (x = 0, 6, 8, 10, and 12) active-core/active-shell nanoparticles (NPs) were peculiarly synthesized via a delayed nucleation pathway with procedures. The phase, shape, and size of the resulting core-shell NPs are confirmed by transmission electron microscopy and X-ray diffraction. Coated with a NaGdF4:10%Er(3+) active shell around the NaGdF4:12%Er(3+) core NPs, a maximum luminescent enhancement of about 336 times higher than the NaGdF4:12%Er(3+) core-only NPs was observed under the 1540 nm excitation. The intensity ratio of green to red was adjusted through the construction of the core-shell structure and the change of Er(3+) concentration in the shell. By analyzing the lifetimes of emission bands and exploring the energy transition mechanism, the giant luminescence enhancement is mainly attributed to the significant increase in the near-infrared absorption at 1540 nm and efficient energy migration from the shell to core.

  16. Local response to light excitation in the charge-ordered phase of (EDO-TTF ) 2Sb F6

    Science.gov (United States)

    Servol, Marina; Moisan, Nicolas; Collet, Eric; Cailleau, Hervé; Kaszub, Wawrzyniec; Toupet, Loïc; Boschetto, Davide; Ishikawa, Tadahiko; Moréac, Alain; Koshihara, Shinya; Maesato, Mitsuhiko; Uruichi, Mikio; Shao, Xiangfeng; Nakano, Yoshiaki; Yamochi, Hideki; Saito, Gunzi; Lorenc, Maciej

    2015-07-01

    The family of materials (EDO-TTF ) 2X F6 represents quasi-one-dimensional quarter filled systems exhibiting insulator-to-metal (I-M) phase transition at thermal equilibrium. (EDO-TTF ) 2P F6 is known to undergo a photoinduced I-M conversion with cooperative response to light excitation. Here we use femtosecond pump-probe experiments to study the photoresponse of (EDO-TTF ) 2Sb F6 made of a larger counteranion Sb F6 compared to the well studied (EDO-TTF ) 2P F6 . In the early stage of the photoinduced process, we reveal a multicomponent coherent oscillating feature. The evolution of this feature with excitation density and temperature points to the local nature of the photoswitching in (EDO-TTF ) 2Sb F6 . At longer time scale, we did not detect the features associated with the transformation to the M phase, albeit observed in the P F6 derivative. We propose a scenario whereby the bigger size of the counteranion in (EDO-TTF ) 2Sb F6 hinders the establishment of this transformation at macroscopic scale.

  17. On the efficient luminescence of beta-Na(La1-xPrx)F-4

    NARCIS (Netherlands)

    Herden, Benjamin; Meijerink, A|info:eu-repo/dai/nl/075044986; Rabouw, Freddy T.; Haase, Markus; Juestel, Thomas

    This work describes the synthesis and the optical properties of beta-NaLaF4 and beta-NaLaF4 doped by Pr3+ as a function of the Pr3+ concentration. It is demonstrated that the emission spectrum is a strong function of the Pr3+ concentration and that the external PL efficiency increases with

  18. Hydrothermal synthesis of NaEuF4 spindle-like nanocrystals

    Indian Academy of Sciences (India)

    Zhi-Jun Wang; Feng Tao; Wei-Li Cai; Lian-Zeng Yao; Xiao-Guang Li

    2011-12-01

    NaEuF4 spindle-like nanocrystals have been synthesized through a simple hydrothermal method. The nanocrystals were well crystallized and exhibited fine morphology, as indicated by X-ray diffraction, transmission electron microscope and selected area electron diffractometer. The luminescence properties of these NaEuF4 products were investigated.

  19. Mössbauer Study of Relaxation Phenomena in (NH4)3FeF6

    DEFF Research Database (Denmark)

    Mørup, Steen; Thrane, N.

    1973-01-01

    The shape of a relaxation-broadened Mössbauer absorption line for a paramagnetic ferric compound is influenced by various terms of the ionic Hamiltonian. Here we discuss especially how the application of an external magnetic field may influence the line shape and may give information about...... the magnitudes of other terms of the ionic Hamiltonian. Measurements on the two phases of (NH4)3FeF6 demonstrate differences between cubic and noncubic surroundings of the ferric ion. In the cubic phase we have found a temperature-independent spin-correlation time τ≃1.19×10-10 sec....

  20. Refined candidate region specified by haplotype sharing for Escherichia coli F4ab/F4ac susceptibility alleles in pigs

    DEFF Research Database (Denmark)

    Jacobsen, M; Kracht, S S; Esteso, G

    2010-01-01

    Infection of the small intestine by enterotoxigenic Escherichia coli F4ab/ac is a major welfare problem and financial burden for the pig industry. Natural resistance to this infection is inherited as a Mendelian recessive trait, and a polymorphism in the MUC4 gene segregating for susceptibility....../resistance is presently used in a selection programme by the Danish pig breeding industry. To elucidate the genetic background involved in E. coli F4ab/ac susceptibility in pigs, a detailed haplotype map of the porcine candidate region was established. This region covers approximately 3.7 Mb. The material used...... for the study is a three generation family, where the founders are two Wild boars and eight Large White sows. All pigs have been phenotyped for susceptibility to F4ab/ac using an adhesion assay. Their haplotypes are known from segregation analysis using flanking markers. By a targeted approach, the candidate...

  1. Crystal field analysis of Pm$^{3+}$ (4$^{f4}) and Sm$^{3+}$ (4$^{f5}) and lattice location studies of $^{147}$Nd and $^{147}$Pm in w-AlN

    CERN Document Server

    Vetter, Ulrich; Nijjar, Anmol S; Zandi, Bahram; Öhl, Gregor; Wahl, Ulrich; De Vries, Bart; Hofsäss, Hans; Dietrich, Marc

    2006-01-01

    We report a detailed crystal field analysis of Pm3+ and Sm3+ as well as lattice location studies of 147Pm and 147Nd in 2H-aluminum nitride (w-AlN). The isotopes of mass 147 were produced by nuclear fission and implanted at an energy of 60 keV. The decay chain of interest in this work is 147Nd→147Pm→147Sm (stable). Lattice location studies applying the emission channeling technique were carried out using the β− particles and conversion electrons emitted in the radioactive decay of 147Nd→147Pm. The samples were investigated as implanted, and also they were investigated after annealing to temperatures of 873 K as well as 1373 K. The main fraction of about 60% of both 147Pm as well as 147Nd atoms was located on substitutional Al sites in the AlN lattice; the remainder of the ions were located randomly within the AlN lattice. Following radioactive decay of 147Nd, the cathodoluminescence spectra of Pm3+ and Sm3+ were obtained between 500 nm and 1050 nm at sample temperatures between 12 K and 300 K. High-re...

  2. ABi2 (IO3 )2 F5 (A=K, Rb, and Cs): A Combination of Halide and Oxide Anionic Units To Create a Large Second-Harmonic Generation Response with a Wide Bandgap.

    Science.gov (United States)

    Liu, Hongming; Wu, Qi; Jiang, Xingxing; Lin, Zheshuai; Meng, Xianggao; Chen, Xingguo; Qin, Jingui

    2017-08-01

    A family of nonlinear optical materials that contain the halide, oxide, and oxyhalide polar units simultaneously in a single structure, namely ABi2 (IO3 )2 F5 (A=K (1), Rb (2), and Cs (3)), have been designed and synthesized. They crystallize in the same polar space group (P21 ) with a two-dimensional double-layered framework constructed by [BiF5 ](2-) and [BiO2 F4 ](5-) units connected to each other by four F atoms, in which two [IO3 ](-) groups are linked to [BiO2 F4 ](5-) unit on the same side. A hanging Bi-F bond of [BiF5 ](2-) unit is located on the other side via ionic interaction with the layer-inserted alkali metal ions to form three-dimensional structure. The well-ordered alignments of these polar units lead to a very strong second-harmonic generation response of 12 (1), 9.5 (2), and 7.5 (3) times larger than that of potassium dihydrogen phosphate under 1064 nm laser radiation. All of them exhibited a wide energy bandgap over 3.75 eV, suggesting that they will have a high laser damage threshold. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Laser performance of LiSrAlF6:Cr3+

    Science.gov (United States)

    Payne, Stephen A.; Chase, L. L.; Smith, L. K.; Kway, Wayne L.; Newkirk, Herbert W.

    1989-08-01

    We have lased the new material, LiSrAlF6:Cr3+ (Cr3+:LiSAF). The single crystals were grown by the horizontal zone melting technique. The spectroscopic properties of Cr3+:LiSAF are similar to those of other low-field Cr3+-doped systems, although the emission cross section is strongly π polarized and is also somewhat larger than has been measured for other fluoride hosts. The free-running lasing wavelength of Cr3+:LiSAF is 825 nm, and the tuning range extends from at least 780 to 920 nm. Using Kr laser pumping, we obtained slope efficiencies of 36% and 14% by utilizing output couplings of 4.8% and 0.8%, respectively. On the basis of these results, the extrapolated maximum efficiency of 53% is determined, to be compared to the quantum defect-limited value of 78%. It is concluded that a moderate level of excited state absorption (ESA) loss is responsible for the reduced efficiency of the Cr3+:LiSAF system. This contrasts with the related results previously obtained for LiCaAlF6:Cr3+, where it was concluded that the effects of ESA were negligible [IEEE J. Quantum Electron. QE-24, 2243 (1988)].

  4. DW-F5: A novel formulation against malignant melanoma from Wrightia tinctoria

    Science.gov (United States)

    Antony, Jayesh; Saikia, Minakshi; V, Vinod.; Nath, Lekshmi. R.; Katiki, Mohana Rao; Murty, M.S.R.; Paul, Anju; A, Shabna; Chandran, Harsha; Joseph, Sophia Margaret; S, Nishanth Kumar.; Panakkal, Elizabeth Jayex; V, Sriramya I.; V, Sridivya I.; Ran, Sophia; S, Sankar; Rajan, Easwary; Anto, Ruby John

    2015-01-01

    Wrightia tinctoria is a constituent of several ayurvedic preparations against skin disorders including psoriasis and herpes, though not yet has been explored for anticancer potential. Herein, for the first time, we report the significant anticancer properties of a semi-purified fraction, DW-F5, from the dichloromethane extract of W. tinctoria leaves against malignant melanoma. DW-F5 exhibited anti-melanoma activities, preventing metastasis and angiogenesis in NOD-SCID mice, while being non-toxic in vivo. The major pathways in melanoma signaling mediated through BRAF, WNT/β-catenin and Akt-NF-κB converging in MITF-M, the master regulator of melanomagenesis, were inhibited by DW-F5, leading to complete abolition of MITF-M. Purification of DW-F5 led to the isolation of two cytotoxic components, one being tryptanthrin and the other being an unidentified aliphatic fraction. The overall study predicts Wrightia tinctoria as a candidate plant to be further explored for anticancer properties and DW-F5 as a forthcoming drug formulation to be evaluated as a chemotherapeutic agent against malignant melanoma. PMID:26061820

  5. Refined candidate region specified by haplotype sharing for Escherichia coli F4ab/F4ac susceptibility alleles in pigs.

    Science.gov (United States)

    Jacobsen, M; Kracht, S S; Esteso, G; Cirera, S; Edfors, I; Archibald, A L; Bendixen, C; Andersson, L; Fredholm, M; Jørgensen, C B

    2010-02-01

    Infection of the small intestine by enterotoxigenic Escherichia coli F4ab/ac is a major welfare problem and financial burden for the pig industry. Natural resistance to this infection is inherited as a Mendelian recessive trait, and a polymorphism in the MUC4 gene segregating for susceptibility/resistance is presently used in a selection programme by the Danish pig breeding industry. To elucidate the genetic background involved in E. coli F4ab/ac susceptibility in pigs, a detailed haplotype map of the porcine candidate region was established. This region covers approximately 3.7 Mb. The material used for the study is a three generation family, where the founders are two Wild boars and eight Large White sows. All pigs have been phenotyped for susceptibility to F4ab/ac using an adhesion assay. Their haplotypes are known from segregation analysis using flanking markers. By a targeted approach, the candidate region was subjected to screening for polymorphisms, mainly focusing on intronic sequences. A total of 18 genes were partially sequenced, and polymorphisms were identified in GP5, CENTB2, APOD, PCYT1A, OSTalpha, ZDHHC19, TFRC, ACK1, MUC4, MUC20, KIAA0226, LRCH3 and MUC13. Overall, 227 polymorphisms were discovered in the founder generation. The analysis revealed a large haplotype block, spanning at least 1.5 Mb around MUC4, to be associated with F4ab/ac susceptibility.

  6. The properties of 5 highly conducting salts - (TMTSF)2X,X=PF6-, AsF6-, SbF6-, BF4- and NO3-, derived from tetramethyltetraselenafulvalene (TMTSF)

    DEFF Research Database (Denmark)

    Bechgaard, K.; Jacobsen, C.S.; Mortensen, K.

    1993-01-01

    The properties of five new highly conducting salts of TMTSF, (TMTSF)2X, X = PF6-, AsF6-, SbF6-, BF4- and NO3- are reported. The measurements include dc. and M.W. conductivity, thermopower, optical reflectivity, magnetic susceptibility and F-19-NMR. Preliminary structural data indicate uniform don...... stacks. Metal to insulator transitions in four materials occur below 20 K, where specific conductivities higher than 10(5) (OMEGA-cm)-1 are observed for two salts (X = PF6- and NO3-).......The properties of five new highly conducting salts of TMTSF, (TMTSF)2X, X = PF6-, AsF6-, SbF6-, BF4- and NO3- are reported. The measurements include dc. and M.W. conductivity, thermopower, optical reflectivity, magnetic susceptibility and F-19-NMR. Preliminary structural data indicate uniform donor...

  7. The electronic structure of HfF5- and WF5-

    Science.gov (United States)

    Chen, Hongshan; Andersson, Pontus; Lindahl, Anton O.; Hanstorp, Dag

    2011-08-01

    The electronic structure of HfF5-, WF5- and the related species HfF n and WF n is studied using ab initio methods. Computation reveals that the hafnium fluorides are much more stable than the corresponding tungsten fluorides. The detachment energy of HfF5- is 8.8 eV, whereas the corresponding quantity of WF5- is only 3.9 eV. These results show that WF5- can be photodetached while HfF5- is unaffected, and so it is possible by using photodetachment to suppress the interfering isobar 182W in the ion beam of 182Hf. Such information is the precondition for the successful implementation of a future photodetachment process in Accelerator Mass Spectrometry.

  8. The E2F5 repressor is an activator of E6/E7 transcription and of the S-phase entry in HPV18-associated cells.

    Science.gov (United States)

    Teissier, S; Pang, C L; Thierry, F

    2010-09-09

    High-risk papillomavirus type 18 (HPV18) is one of the less represented HPV types in low-grade lesions of the anogenital tract, whereas it occupies the second place in cervical cancer, where it can be found in 16% of the cases worldwide, after HPV16 present in 54% of them. These epidemiological data indicate that HPV18 infection is more prone to carcinogenic progression. The main oncogenic proteins, E6 and E7 of HPV18, are functionally comparable to the homologous proteins of the other high-risk viruses, including HPV16. In this work, we investigated the possibility that the higher oncogenic potential of HPV18 might be due to transcriptional regulation of the E6/E7 oncogenes. By comparing the E6/E7 promoter and enhancer sequences of the mucosal HPV genomes, we identified E2F binding sites specific for HPV18. The E2F family of transcription factors contains activators (E2F1-3) and repressors (E2F4-8) that regulate the transcription of S-phase and mitotic genes and thereby have a crucial role in cell-cycle progression. Surprisingly, we identified E2F5 as a direct activator of HPV18 E6/E7 transcription by sequential silencing of E2F members in HeLa cells. In addition, we could show that E2F5 positively regulates S-phase entry in HeLa cells and that this activation of the cell cycle by a member of the E2F repressor family is specific for HPV18-expressing cells. Diverting the function of E2F5 from a cell-cycle repressor into an activator might contribute to the higher oncogenic potential of HPV18 when compared with other high-risk HPV types.

  9. Expression and biochemical characterization of light chains of Botulinum neurotoxin subtypes F5 and F7.

    Science.gov (United States)

    Guo, Jiubiao; Chen, Sheng

    2015-07-01

    Botulinum neurotoxins are the most potent protein toxins known to human. To date, seven subtypes of the BoNT/F serotype (BoNT/F1 to BoNT/F7) have been identified, among which BoNT/F5 and BoNT/F7 are the most divergent. However, little structural and functional information is available for these two subtypes due to a lack of suitable recombinant proteins for biochemical characterization, except that they appear to possess unique substrate recognition mechanisms, thereby impeding development of vaccine or inhibitors against these proteins. In the present study, we utilized a combinatorial approach which involved examining the effects of different affinity tags, mapping C-terminal truncation mutants and optimization of expression and purification conditions, that allowed us to successfully express and purify soluble and highly active recombinant LC/F5 and LC/F7 proteins. GST-LC/F5(1-450) and 6× His-LC/F5(1-405) were the formats which exhibit the highest level of solubility and activity, whereas GST-LC/F7(1-405) was the most active form of LC/F7. In comparison, GST-LC/F5(1-450) was more active than GST-LC/F7(1-405), which was in turn more active than the LC/F1 control. Our data suggest that solubility of these proteins strongly correlated with their catalytic activity. Successful expression and purification of LC/F5 and LC/F7 in this work will, for the first time, provide materials for further characterization of these two subtypes of BoNT/F, which is essential for future development of protective vaccine or other therapeutic strategies, as well as BoNT/F protein engineering. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. E2F5 status significantly improves malignancy diagnosis of epithelial ovarian cancer

    KAUST Repository

    Kothandaraman, Narasimhan

    2010-02-24

    Background: Ovarian epithelial cancer (OEC) usually presents in the later stages of the disease. Factors, especially those associated with cell-cycle genes, affecting the genesis and tumour progression for ovarian cancer are largely unknown. We hypothesized that over-expressed transcription factors (TFs), as well as those that are driving the expression of the OEC over-expressed genes, could be the key for OEC genesis and potentially useful tissue and serum markers for malignancy associated with OEC.Methods: Using a combination of computational (selection of candidate TF markers and malignancy prediction) and experimental approaches (tissue microarray and western blotting on patient samples) we identified and evaluated E2F5 transcription factor involved in cell proliferation, as a promising candidate regulatory target in early stage disease. Our hypothesis was supported by our tissue array experiments that showed E2F5 expression only in OEC samples but not in normal and benign tissues, and by significantly positively biased expression in serum samples done using western blotting studies.Results: Analysis of clinical cases shows that of the E2F5 status is characteristic for a different population group than one covered by CA125, a conventional OEC biomarker. E2F5 used in different combinations with CA125 for distinguishing malignant cyst from benign cyst shows that the presence of CA125 or E2F5 increases sensitivity of OEC detection to 97.9% (an increase from 87.5% if only CA125 is used) and, more importantly, the presence of both CA125 and E2F5 increases specificity of OEC to 72.5% (an increase from 55% if only CA125 is used). This significantly improved accuracy suggests possibility of an improved diagnostics of OEC. Furthermore, detection of malignancy status in 86 cases (38 benign, 48 early and late OEC) shows that the use of E2F5 status in combination with other clinical characteristics allows for an improved detection of malignant cases with sensitivity

  11. ANALISIS MORFOMETRIK DAN MERISTIK NILA (Oreochromis sp.) STRAIN LARASATI F5 DAN TETUANYA

    OpenAIRE

    Muhotimah, Muhotimah; Triyatmo, Bambang; Priyono, Susilo B.; Kuswoyo, Toni

    2016-01-01

    Cross-breeding between Janti’s Black Tilapia (female parent) and Janti’s White Tilapia (male parent) has been performed by Institution of Germination and Freshwater Fish Farming which is located at Janti Village – District of Klaten and produced Tilapia Larasati (Red Tilapia Strain Janti) F5. This study aimed to compare the Tilapia Larasati F5 and it parents based on morphometric and meristic characters, and to know the length-weight relationship of three strains of tilapia. Analysis of morph...

  12. Structure and heat capacity of the NaCeF4 compound

    Institute of Scientific and Technical Information of China (English)

    Virgil Constantin; Ana-Maria Popescu

    2013-01-01

    This work continued our general research program on obtaining metallic cerium by electrodeposition from NaCeF4 dis-solved in different molten fluorides. The structure of NaCeF4 (cubic or hexagonal depending on the way of preparation) was estab-lished by DTA analysis, IR spectra and X-ray diffraction. The heat capacity (Cp) of NaCeF4 was measured by differential scanning calorimetry in the temperature range of 300-1093 K using the“step-method”. The Cp was fitted by an equation with a satisfactory re-sult. Heat capacity was compared with that calculated from the Neumann-Kopp rule (NKR) and the deviations observed were consis-tent with the stability of the NaCeF4 compound.

  13. Silicon electrodeposition from chloride-fluoride melts containing K2SiF6 and SiO2

    Directory of Open Access Journals (Sweden)

    Zhuk Sergey I.

    2017-01-01

    Full Text Available Silicon electrodeposition on glassy carbon from the KF-KCl-K2SiF6, KF-KCl-K2SiF6-KOH and KF-KCl-K2SiF6-SiO2 melts was studied by the cyclic voltammetry. Тhe electroreduction of Si(IV to metallic Si was observed as a single 4-electron wave under all considered conditions. The reactions of cathode reduction of silicon from fluoride and oxyfluoride complexes were suggested. It was shown that the process can be controlled by the preliminary transformation of SiO44- to SiF62- and SiOxFyz-. The influence of the current density on structure and morphology of silicon deposits obtained during galvanostatic electrolysis of the KF-KCl-K2SiF6-SiO2 melt was studied.

  14. Magnetic exchange interaction via HF 2--bridges? Structure and magnetism of pipzH 2[MnF 4(HF 2)

    Science.gov (United States)

    Bentrup, U.; Harms, K.; Massa, W.; Pebler, J.

    2000-05-01

    pipzH 2[MnF 4(HF 2)] (pipz=piperazine) has been prepared from an aqueous hydrofluoric acid solution of Mn(III) acetate and its crystal structure was determined by single-crystal X-ray analysis: triclinic, space group Poverline11¯, Z=1, a=5.636(1), b=6.151(1), c=6.498(1) Å, α=99.52(1), β=90.62(1), γ=107.43(1)°, wR2=0.063, R=0.023. The structure consists of hitherto unique anionic chains where [MnF 4] units are bridged by HF 2- anions. The resulting [MnF 6] octahedra are strongly elongated, mainly due to the Jahn-Teller effect ( 1.84 Å, MnF ax 2.19 Å). The geometry of the centrosymmetrical bifluoride anion is close to that of KHF 2 (HF 1.14 Å), the angles at the angular bridge MnFH are 111.7°. Surprisingly, magnetic investigations revealed pure paramagnetic behavior. Thus, in contrast to several examples where antiferromagnetic coupling was observed via OH⋯F hydrogen bonds, the very strong hydrogen bonds in the symmetric F⋯H⋯F - anion are obviously not able to mediate magnetic exchange interactions.

  15. Characterization of solar-grade silicon produced by the SiF4-Na process

    Science.gov (United States)

    Sanjurjo, A.; Sancier, K. M.; Emerson, R. M.; Leach, S. C.; Minahan, J.

    1986-01-01

    A process was developed for producing low cost solar grade silicon by the reaction between SiF4 gas and sodium metal. The results of the characterization of the silicon are presented. These results include impurity levels, electronic properties of the silicon after crystal growth, and the performance of solar photovoltaic cells fabricated from wafers of the single crystals. The efficiency of the solar cells fabricated from semiconductor silicon and SiF4-Na silicon was the same.

  16. LiY0.3Lu0.7F4: Ce3+,Pr3+ Mixed Crystal as a Perspective Up-Conversionally Pumped UV Active Medium

    Science.gov (United States)

    Gorieva, V. G.; Semashko, V. V.; Korableva, S. L.; Marisov, M. A.; Pavlov, V. V.

    2015-09-01

    Investigation results of effective population of states of 5d-configuration of Ce3+ ions by energy transfer from Pr3+ ions in LiY0.3Lu0.7F4 (LYLF) crystals are discussed. The real concentrations of Pr3+ and Ce3+ ions in LYLF crystals are determined. Such parameters as excited 4f-5d state photoionization cross-section of Pr3+ ions, ground state cross-section of Ce3+ ions at 266 nm wavelengths and energy transfer coefficients of energy transfer from Pr3+ to Ce3+ ions were estimated. The results of pump-probe experiments on 5d-4f transitions of Ce3+ ions in LYLF crystals are presented. The optimal parameters for getting maximal gain on 5d-4f transitions of Ce3+ ions were determined by mathematical modeling.

  17. Bridging Binding Modes of Phosphine-Stabilized Nitrous Oxide to Zn(C6F5)2

    NARCIS (Netherlands)

    Neu, Rebecca C.; Otten, Edwin; Stephan, Douglas W.

    2009-01-01

    Reaction of [tBu3PN2O(B(C6H4F)3)] with 1, 1.5, or 2 equivalents of Zn(C6F5)2 affords the species [{tBu3PN2OZn(C6F5)2}2], [{tBu3PN2OZn(C6F5)2}2Zn(C6F5)2], and [tBu3PN2O{Zn(C6F5)2}2] displaying unique binding modes of Zn to the phosphine-stabilized N2O fragment.

  18. Lanthanide-doped NaScF4 nanoprobes: crystal structure, optical spectroscopy and biodetection

    Science.gov (United States)

    Ai, Yu; Tu, Datao; Zheng, Wei; Liu, Yongsheng; Kong, Jintao; Hu, Ping; Chen, Zhuo; Huang, Mingdong; Chen, Xueyuan

    2013-06-01

    Trivalent lanthanide ions (Ln3+)-doped inorganic nanoparticles (NPs) as potential luminescent bioprobes have been attracting tremendous interest because of their unique upconversion (UC) and downconversion (DC) luminescence properties. NaScF4, as an important host material, has been rarely reported and its crystal structure remains unclear. Herein, based on the single crystal X-ray diffraction, the space group of NaScF4 crystals was determined to be P31 containing multiple sites of Sc3+ with crystallographic site symmetry of C1, which was verified by high-resolution photoluminescence spectroscopy of Eu3+ at low temperature (10 K). Furthermore, monodisperse and size-controllable NaScF4:Ln3+ NPs were synthesized via a facile thermal decomposition method. The biotinylated NaScF4:Er3+/Yb3+ NPs were demonstrated for their applications as a heterogeneous UC luminescence bioprobe to detect avidin with a detection limit of 180 pM. After bioconjugation with amino-terminal fragment (ATF) of urokinase plasminogen activator (uPA), NaScF4:Ln3+ NPs also exhibited specific recognition of cancer cells overexpressed with uPA receptor (uPAR, an important marker of tumor biology and metastasis), showing great potentials in tumor-targeted bioimaging.Trivalent lanthanide ions (Ln3+)-doped inorganic nanoparticles (NPs) as potential luminescent bioprobes have been attracting tremendous interest because of their unique upconversion (UC) and downconversion (DC) luminescence properties. NaScF4, as an important host material, has been rarely reported and its crystal structure remains unclear. Herein, based on the single crystal X-ray diffraction, the space group of NaScF4 crystals was determined to be P31 containing multiple sites of Sc3+ with crystallographic site symmetry of C1, which was verified by high-resolution photoluminescence spectroscopy of Eu3+ at low temperature (10 K). Furthermore, monodisperse and size-controllable NaScF4:Ln3+ NPs were synthesized via a facile thermal

  19. Cloning, bioinformatics analysis, and expression of the dust mite allergen Der f 5 of Dermatophagoides farinae

    Directory of Open Access Journals (Sweden)

    Yubao Cui

    2012-08-01

    Full Text Available Crude extracts of house dust mites are used clinically for diagnosis and immunotherapy of allergic diseases, including bronchial asthma, perennial rhinitis, and atopic dermatitis. However, crude extracts are complexes with non-allergenic antigens and lack effective concentrations of important allergens, resulting in several side effects. Dermatophagoides farinae (Hughes; Acari: Pyroglyphidae is one of the predominant sources of dust mite allergens, which has more than 30 groups of allergen. The cDNA coding for the group 5 allergen of D. farinae from China was cloned, sequenced and expressed. According to alignment using the VECTOR NTI 9.0 software, there were eight mismatched nucleotides in five cDNA clones resulting in seven incompatible amino acid residues, suggesting that the Der f 5 allergen might have sequence polymorphism. Bioinformatics analysis revealed that the matured Der f 5 allergen has a molecular mass of 13604.03 Da, a theoretical pI of 5.43 and is probably hydrophobic and cytoplasmic. Similarities in amino acid sequences between Der f 5 and allergens of other domestic mite species, viz. Der p 5, Blo t 5, Sui m 5, and Lep d 5, were 79, 48, 53, and 37%, respectively. Phylogenetic analysis indicated that Der f 5 and Der p 5 clustered together. Blo t 5 and Ale o 5 also clustered together, although Blomia tropicalis and Aleuroglyphus ovatus belong to different mite families, viz. Echimyopodidae and Acaridae, respectively.

  20. Structural and energetic properties of haloacetonitrile - GeF4 complexes

    Science.gov (United States)

    Waller, Anna W.; Weiss, Nicole M.; Decato, Daniel A.; Phillips, James A.

    2017-02-01

    The 1:1 and 2:1 complexes of FCH2CN and ClCH2CN with GeF4 have been investigated by M06/aug-cc-pVTZ calculations, low-temperature, thin-film IR spectroscopy, and an x-ray structure has been obtained for (FCH2CN)2-GeF4. Theoretical structures and binding energies for FCH2CN-GeF4 and ClCH2CN-GeF4 demonstrate that halogen substitution significantly weakens the Ge-N dative bonds. The Ge-N distances for the F- and Cl-complexes (2.447 and 2.407 Å, respectively) are about 0.2 Å longer than in CH3CN-GeF4, and the binding energies (6.5 and 6.9 kcal/mol) are 2-3 kcal/mol less. Furthermore, the Ge-N potential curves are flatter for the halogenated complexes, exhibit a greater response to dielectric media, and thus these systems are more prone to structural change in condensed-phases. For the 2:1 complexes, experimental and theoretical structure and frequency data are consistent with differences in the (calculated) gas-phase and solid-state structures. For (FCH2CN)2-GeF4 the calculated gas-phase structure has Ge-N distances about 0.3 Å longer those in the x-ray structure (2.366 Å vs. 2.059 Å (ave)). Also, low-temperature IR spectra of CH3CN/GeF4, FCH2CN/GeF4, and ClCH2CN/GeF4 thin films are consistent with the presence of 2:1 nitrile:GeF4 complexes, and the splitting patterns of the GeF-stretching bands (∼700 cm-1) match predictions for the corresponding complexes, but are red-shifted relative to the gas-phase predictions, and reflect Ge-N bonds that are compressed in the solid-state, relative to predicted gas-phase structures.

  1. The unexpectedly bright comet C/2012 F6 (Lemmon) unveiled at near-infrared wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    Paganini, Lucas; DiSanti, Michael A.; Mumma, Michael J.; Villanueva, Geronimo L.; Bonev, Boncho P. [Goddard Center for Astrobiology, NASA GSFC, MS 690, Greenbelt, MD 20771 (United States); Keane, Jacqueline V.; Meech, Karen J. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Gibb, Erika L. [Department of Physics and Astronomy, University of Missouri, St. Louis, MO 63121 (United States); Boehnhardt, Hermann, E-mail: lucas.paganini@nasa.gov [Max-Planck-Institut für Sonnensystemforschung, D-37191, Katlenburg-Lindau (Germany)

    2014-01-01

    We acquired near-infrared spectra of the Oort cloud comet C/2012 F6 (Lemmon) at three different heliocentric distances (R {sub h}) during the comet's 2013 perihelion passage, providing a comprehensive measure of the outgassing behavior of parent volatiles and cosmogonic indicators. Our observations were performed pre-perihelion at R {sub h} = 1.2 AU with CRIRES (on 2013 February 2 and 4), and post-perihelion at R {sub h} = 0.75 AU with CSHELL (on March 31 and April 1) and R {sub h} = 1.74 AU with NIRSPEC (on June 20). We detected 10 volatile species (H{sub 2}O, OH* prompt emission, C{sub 2}H{sub 6}, CH{sub 3}OH, H{sub 2}CO, HCN, CO, CH{sub 4}, NH{sub 3}, and NH{sub 2}), and obtained upper limits for two others (C{sub 2}H{sub 2} and HDO). One-dimensional spatial profiles displayed different distributions for some volatiles, confirming either the existence of polar and apolar ices, or of chemically distinct active vents in the nucleus. The ortho-para ratio for water was 3.31 ± 0.33 (weighted mean of CRIRES and NIRSPEC results), implying a spin temperature >37 K at the 95% confidence limit. Our (3σ) upper limit for HDO corresponds to D/H < 2.45 × 10{sup –3} (i.e., <16 Vienna Standard Mean Ocean Water, VSMOW). At R {sub h} = 1.2 AU (CRIRES), the production rate for water was Q(H{sub 2}O) = 1.9 ± 0.1 × 10{sup 29} s{sup –1} and its rotational temperature was T {sub rot} ∼ 69 K. At R {sub h} = 0.75 AU (CSHELL), we measured Q(H{sub 2}O) = 4.6 ± 0.6 × 10{sup 29} s{sup –1} and T {sub rot} = 80 K on March 31, and 6.6 ± 0.9 × 10{sup 29} s{sup –1} and T {sub rot} = 100 K on April 1. At R {sub h} = 1.74 AU (NIRSPEC), we obtained Q(H{sub 2}O) = 1.1 ± 0.1 × 10{sup 29} s{sup –1} and T {sub rot} ∼ 50 K. The measured volatile abundance ratios classify comet C/2012 F6 as rather depleted in C{sub 2}H{sub 6} and CH{sub 3}OH, while HCN, CH{sub 4}, and CO displayed abundances close to their median values found among comets. H{sub 2}CO was the only volatile

  2. Remaining Sites Verification Package for the 1607-F5 Sanitary Sewer System (124-F-5), Waste Site Reclassification Form 2006-043

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2006-09-14

    The 1607-F5 waste site is a former septic tank, tile field, and associated pipeline located within the 100-FR-1 Operable Unit that received sewage from the former 181-F Pumphouse. Lead, gamma-chlordane, and heptachlor epoxide were identified within or around the septic system at concentrations exceeding the direct exposure cleanup criteria. Multiple metal and pesticide constituents were also identified as exceeding the groundwater and river protection cleanup criteria. The results of verification sampling demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River.

  3. New fluorescence results of Fe^3+ ions in Cs_2NaScF_6

    Science.gov (United States)

    Sosman, L. P.; da Fonseca, R. J. M.; Dias Tavaves, A., Jr.; Bordallo, H. N.; Khaidukov, N. M.

    2002-03-01

    Many spectroscopic studies on oxide materials doped with trivalent iron ions have been reported in the literature [1-4]. However, investigation on Fe3^+ luminescence in fluoride hosts is comparatively rare at the moment. In this work we present the initial fluorescence results for Cs_2NaGaF_6:Fe3^+. The emission spectrum at room temperature exhibits a broad emission band with maximum intensity at 800 nm. We believe that this emission is associated with substitutional occupancy of the octahedral Ga3^+ sites by iron ions. We also observe a band at 600 nm that corresponds probably to defect centers. [1] O´Connor G, McDonagh C, Glynn T J, 1991 J Luminescence 48 & 49 545 [2] Walker G, Glynn T J 1992 J Luminescence 54 131 [3] Kutty T R N, Nayak M, 1998 Journal of Alloys and Compounds 269 75 [4] Sosman L P, Dias Tavares Jr. A, Silva P S, Abritta T 1999 176 1085

  4. Could the Optical Transient SCP 06F6 be due to Microlensing?

    Indian Academy of Sciences (India)

    Marek Biesiada

    2010-12-01

    In this paper, we consider the mysterious optical transient SCP 06F6 displaying a symmetric light curve with a (half-time) duration of about 100 days. The projected location of the event falls close to the center of the galaxy cluster CL 1432.5 + 332.8 lying at the redshift = 1.112. Guided by suggestive symmetry of the light curve and its similarity in two photometric bands, which is a typical signature of microlensing events, we discuss this possibility in several scenarios. As a consistency check we use the lens mass inferred from the event duration and the size of the source. The second check comes from a plausible assumption that since the event was highly magnified there was a perfect alignment at the maximum magnification. A scenario where the lens and the source are located in our Galaxy is ruled out. There remain extragalactic scenarios in which the source is a broad absorption line quasar at redshift 2.7 (as might be suggested by transient’s spectroscopy) and the lens could be a compact object associated either with the cluster or with quasar’s host galaxy. They give reasonable results. Even if the true nature of the transient eventually turns out different, the idea presented here is interesting from the perspective of cosmological microlensing studies.

  5. Experimental infection with Escherichia coli 0149 : F4ac in weaned piglets

    DEFF Research Database (Denmark)

    Jensen, Gerda M.; Frydendahl, Kai; Svendsen, Ove

    2006-01-01

    for the production of the specific ETEC F4ab/ac receptor, and a DNA marker-based test has been developed to allow genotyping for ETEC F4ab/ac resistance/susceptibility [Jorgensen, C.B., Cirera, S., Archibald, A.L., Anderson, L., Fredholm, M., Edfors-Lilja, I., 2004. Porcine polymorphisms and methods for detecting...... them. International application published under the patent cooperation treaty (PCT). PCT/DK2003/000807 or WO2004/048606-A2]. The aim of this study was to test an experimental model for ETEC O149:F4ac-induced diarrhoea in piglets, selected for susceptibility towards ETEC O149:F4ac adhesion prior...... to experimentation using a DNA marker-based test. Sixty-two healthy 25-32 days old recently weaned Danish crossbred piglets were used. All piglets were tested prior to experimentation for susceptibility or resistance towards ETEC 0149:F4ac adhesion. Thirty-nine piglets, both susceptible and resistant, were oro...

  6. ANALISIS KESELAMATAN GEDUNG BARU F5 UNIVERSITAS NEGERI SEMARANG SEBAGAI UPAYA TANGGAP TERHADAP KEADAAN DARURAT

    Directory of Open Access Journals (Sweden)

    Evi Widowati

    2017-04-01

    Full Text Available Abstrak   Gedung F5 adalah gedung baru di Fakultas Ilmu Keolahragaan yang masih memiliki sarana keselamatan gedung yang sangat minim, dimana gedung ini memiliki potensi untuk terjadi kebakaran ataupun bencana alam lainnya. Tujuan penelitian ini adalah menghasilkan suatu rekomendasi sebagai upaya perbaikan dalam aspek keselamatan terhadap gedung baru F5 Universitas Negeri Semarang. Penelitian ini dengan menggunakan metode penelitian deskriptif komparatif. Hasil dari 103 poin yang dibahas, sebanyak 41 poin (39,8% terpenuhi dan sesuai dengan standar/peraturan. Sebanyak 12 poin (11,7% terpenuhi namun belum sesuai dengan standar/peraturan dan sebanyak 50 poin (48,5% tidak terpenuhi. Saran untuk penelitian ini antara lain yaitu memasang instalasi alarm kebakaran, titik panggil manual, hidran, sprinkler, tanda pemasangan pada setiap APAR, dan memasang kembali check sheet yang hilang. Selain itu memasang pintu darurat, tangga darurat, pencahayaan darurat, memperbaiki penunjuk arah evakuasi darurat, menambah 1 area untuk titik berkumpul, menambah 1 akses untuk jalur keluar atau memperlebar jalur akses masuk tersebut menjadi minimal 4 dan ideal 5,5 meter dan melengkapi dengan cermin cembung setiap tikungan yang ada pada akses masuk gedung F5 sebanyak 3 unit.   Kata Kunci : Keselamatan, gedung, darurat.     Abstract F5 Building is a new building in the Faculty of Sport Science which still has very minimal building safety facilities.The purpose of this research is to produce a recommendation as an effort to improve the safety aspect of the new building of F5 State University of Semarang. This research used comparative descriptive research method and focus on 103 topic points of safety building. From observation and analysis, it resulted 41 points (39.8% were met and in accordance with the standards / regulations. A total of 12 points (11.7% are met but not in accordance with the standard / regulation and as many as 50 points (48.5% are not met

  7. Three-component synthesis of C2F5-substituted pyrazoles from C2F5CH2NH2·HCl, NaNO2 and electron-deficient alkynes

    Directory of Open Access Journals (Sweden)

    Pavel K. Mykhailiuk

    2015-01-01

    Full Text Available A one-pot reaction between C2F5CH2NH2·HCl, NaNO2 and electron-deficient alkynes gives C2F5-substituted pyrazoles in excellent yields. The transformation smoothly proceeds in dichloromethane/water, tolerates the presence of air, and requires no purification of products by column chromatography. Mechanistically, C2F5CH2NH2·HCl and NaNO2 react first in water to generate C2F5CHN2, that participates in a [3 + 2] cycloaddition with electron-deficient alkynes in dichloromethane.

  8. Electronic properties of the charge transfer material MnPc/F4TCNQ

    Science.gov (United States)

    Rückerl, Florian; Mahns, Benjamin; Dodbiba, Eni; Nikolis, Vasileios; Herzig, Melanie; Büchner, Bernd; Knupfer, Martin; Hahn, Torsten; Kortus, Jens

    2016-09-01

    We present electronic properties of a charge transfer material consisting of Manganese(ii)Phthalocyanine (MnPc) and 2,3,5,6-Tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), investigated by means of photoemission spectroscopy and electron energy-loss spectroscopy, as well as supporting density functional theory calculations. We report the successful formation of a bulk material characterized by a strong interaction of the molecular compounds which affects the optical properties significantly. Our investigations reveal a significant charge transfer, whereas the MnPc molecule is oxidized and F4TCNQ is reduced. The valence band data indicate a full charge transfer between the two partners. The electronic excitation spectrum reveals a relatively small energy gap of MnPc/F4TCNQ of about 0.7 eV, which is related to a charge transfer excitation.

  9. Laser induced broad band anti-Stokes white emission from LiYbF4 nanocrystals

    Institute of Scientific and Technical Information of China (English)

    L. Marciniak; R. Tomala; M. Stefanski; D. Hreniak; W. Strek

    2016-01-01

    Spectroscopic properties of tetragonal LiYbF4 nanocrystals under high dense NIR excitation at vacuum condition were in-vestigated. White, broad band emission covering whole visible part of the spectrum from LiYbF4 nanocrystals was observed. Its in-tensity strongly depended on the excitation power, excitation wavelength and ambient pressure. Temperature of the nanocrystals un-der 975 nm excitation was determined as a function of excitation power. Strong photo-induced current was observed from LiYbF4 pallet. The emission kinetic was analyzed. The mechanism of the anti-Stokes white emission was discussed in terms of the la-ser-induced charge transfer emission from Yb2+ states.

  10. Frustrated Lewis Pair Behavior of Intermolecular Annine/B(C6F5)(3) Pairs

    NARCIS (Netherlands)

    Voss, Tanja; Mahdi, Tayseer; Otten, Edwin; Froehlich, Roland; Kehr, Gerald; Stephan, Douglas W.; Erker, Gerhard

    2012-01-01

    Reactions of N,N-dimethylaniline, N-isopropyl-aniline, 1,4-C6H4(CH(2)NHtBu)(2), and benzyldimethylamine with the Lewis acid B(C6F5)(3) have been studied. In the case of N,N-dirnethylaniline the combination of the Lewis acid and base forms an almost completely noninteracting frustrated Lewis pair, wh

  11. FAST ROTATION AND TRAILING FRAGMENTS OF THE ACTIVE ASTEROID P/2012 F5 (GIBBS)

    Energy Technology Data Exchange (ETDEWEB)

    Drahus, Michał; Waniak, Wacław [Astronomical Observatory, Jagiellonian University, Kraków (Poland); Tendulkar, Shriharsh [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA (United States); Agarwal, Jessica [Max Planck Institute for Solar System Research, Göttingen (Germany); Jewitt, David [Department of Earth, Planetary and Space Sciences and Department of Physics and Astronomy, University of California at Los Angeles, Los Angeles, CA (United States); Sheppard, Scott S., E-mail: drahus@oa.uj.edu.pl [Department of Terrestrial Magnetism, Carnegie Institution for Science, Washington, DC (United States)

    2015-03-20

    While having a comet-like appearance, P/2012 F5 (Gibbs) has an orbit native to the Main Asteroid Belt, and physically is a km-sized asteroid which recently (mid 2011) experienced an impulsive mass ejection event. Here we report new observations of this object obtained with the Keck II telescope on UT 2014 August 26. The data show previously undetected 200 m scale fragments of the main nucleus, and reveal a rapid nucleus spin with a rotation period of 3.24 ± 0.01 hr. The existence of large fragments and the fast nucleus spin are both consistent with rotational instability and partial disruption of the object. To date, many fast rotators have been identified among the minor bodies, which, however, do not eject detectable fragments at the present-day epoch, and also fragmentation events have been observed, but with no rotation period measured. P/2012 F5 is unique in that for the first time we detected fragments and quantified the rotation rate of one and the same object. The rapid spin rate of P/2012 F5 is very close to the spin rates of two other active asteroids in the Main Belt, 133P/Elst-Pizarro and (62412), confirming the existence of a population of fast rotators among these objects. But while P/2012 F5 shows impulsive ejection of dust and fragments, the mass loss from 133P is prolonged and recurrent. We believe that these two types of activity observed in the rapidly rotating active asteroids have a common origin in the rotational instability of the nucleus.

  12. LiCaAlF6 scintillators in neutron and gamma radiation fields

    Science.gov (United States)

    Viererbl, L.; Klupák, V.; Vinš, M.; Koleška, M.; Šoltés, J.; Yoshikawa, A.; Nikl, M.

    2016-09-01

    Intentionally doped LiCaAlF6 (LiCAF) single crystals are prospective scintillators, especially for thermal neutron detection through the 6Li(n,t)4He nuclear reaction. Four different LiCAF scintillator samples were tested in various neutron and gamma fields. Two of the tested samples were LiCAF:Eu and LiCAF:Eu,Na single crystals, and another two samples were made of LiCAF:Eu micro crystals dispersed in transparent rubber, with different rubber dimensions. All LiCAF samples contain lithium enriched to6Li. A plutonium-beryllium source was used as a neutron source. The neutron spectrum was modified by moderator and filter to get different ratios between thermal, epithermal and fast neutron fluence rates. The MCNP code was used for calculations of the fluence rates for different configurations. Radionuclides 137Cs and 60Co were applied as gamma radiation sources. The light signal from the scintillator was evaluated with a photomultiplier and a multichannel analyzer. The purpose of this work was to study the characteristics of LiCAF scintillators, especially the ability to discriminate signals from neutron and gamma radiation, which is the basic scintillator condition for neutron detection in mixed neutron-gamma radiation fields. Generally, the discrimination can be done by the pulse height and/or the pulse shape of the evaluated signals. Both methods can be used for a LiCAF scintillator. However, only the pulse height discrimination method is discussed in this paper. The possibility of fast neutron detection with LiCAF scintillators was also tested.

  13. Spontaneous Magnetization in the Dipolar Ising Ferromagnet LiTbF4

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage; Holmes, L. M.; Krebs Larsen, F.

    1975-01-01

    The spontaneous magnetization μ in Bohr magnetons below TC=2.874 K in LiTbF4 has been measured by magnetic Bragg scattering of neutrons. The data were normalized by comparing the magnetic Bragg scattering to the nuclear Bragg scattering at T>TC. The nuclear structure factors as well as the extinc......The spontaneous magnetization μ in Bohr magnetons below TC=2.874 K in LiTbF4 has been measured by magnetic Bragg scattering of neutrons. The data were normalized by comparing the magnetic Bragg scattering to the nuclear Bragg scattering at T>TC. The nuclear structure factors as well...

  14. Magnetic phase diagram of the coupled triangular spin tubes for CsCrF4

    Science.gov (United States)

    Seki, Kouichi; Okunishi, Kouichi

    2015-06-01

    Using Monte Carlo simulations, we explore the magnetic phase diagram of triangular spin tubes coupled with a ferromagnetic intertube interaction for CsCrF4. The planar structure of the coupled tubes is topologically equivalent to the kagome-triangular lattice, which induces nontrivial frustration effects in the system. We particularly find that, depending on the intertube coupling, various ordered phases are actually realized, such as incommensurate order, ferromagnetic order, and cuboc order, which is characterized by the noncoplanar spin structure of the 12 sublattices accompanying the spin chirality breaking. We also discuss the relevance of the results to recent experiments on CsCrF4.

  15. Experimental infection with Escherichia coli O149:F4ac in weaned piglets.

    Science.gov (United States)

    Jensen, Gerda M; Frydendahl, Kai; Svendsen, Ove; Jørgensen, Claus B; Cirera, Susanna; Fredholm, Merete; Nielsen, Jens-Peter; Møller, Kristian

    2006-06-15

    The outcome of experimental intestinal infections with enterotoxigenic Escherichia coli (ETEC) is dependent on several factors. An important factor is adhesion of the challenge strain to the intestinal mucosa. The test for susceptibility towards ETEC adhesion has so far been made by an intestinal adhesion test made after slaughter of piglets. However, in an experimental infection study with the purpose to obtain diarrhoeic piglets, it would be an advantage to test for susceptibility prior to experimentation. The Mucin 4 gene on porcine chromosome 13 has been proposed as a candidate gene for the production of the specific ETEC F4ab/ac receptor, and a DNA marker-based test has been developed to allow genotyping for ETEC F4ab/ac resistance/susceptibility [Jørgensen, C.B., Cirera, S., Archibald, A.L., Anderson, L., Fredholm, M., Edfors-Lilja, I., 2004. Porcine polymorphisms and methods for detecting them. International application published under the patent cooperation treaty (PCT). PCT/DK2003/000807 or WO2004/048606-A2]. The aim of this study was to test an experimental model for ETEC O149:F4ac-induced diarrhoea in piglets, selected for susceptibility towards ETEC O149:F4ac adhesion prior to experimentation using a DNA marker-based test. Sixty-two healthy 25-32 days old recently weaned Danish crossbred piglets were used. All piglets were tested prior to experimentation for susceptibility or resistance towards ETEC O149:F4ac adhesion. Thirty-nine piglets, both susceptible and resistant, were oro-gastric intubated with 10(9)CFU of ETEC O149:F4ac and 23 age-matched piglets, both susceptible and resistant, were used as non-infected controls. Of susceptible piglets, challenged with ETEC O149:F4ac, 74% had ETEC O149:F4ac-associated diarrhoea first day after first challenge, which were significantly higher relatively to the resistant and challenged piglets where 20% had diarrhoea (p=0.04). This study suggests a model for experimental ETEC induced diarrhoea.

  16. Controls on hydrocarbon occurrence and productivity in the F6 reservoir, Tin Fouye-Tabankort area, NW Illizi Basin

    Energy Technology Data Exchange (ETDEWEB)

    Alem, N.; Assassi, S.; Benhebouche, S.; Kadi, B. [CDR-Sonatrach, Boumerdes (Algeria)

    1998-12-31

    Several oil accumulations of various sizes have been found within the F6 reservoir of Upper Silurian-Lower Devonian age in the Tin Fouye region of the Illizi Basin, about 1500 km from Algiers. Lithologically, the F6 consists of interbedded sandstones and shales and is subdivided into units: M1, M2, A, B1, B2, C1, C2 and C3, the upper units often being missing through erosion. These reservoirs, which were deposited in offshore coastal bars and tidal channels, show a high degree of lateral and vertical facies variation. Study of the hydrology of the F6 reservoir shows that connate water and oil have been frequently flushed by fresh water in the most permeable units, particularly C1 and B2. This finding is supported by hydrochemical data, by the inclination of oil-water contacts and by a high observed hydraulic gradient. (author)

  17. Studies of PuF6 and transplutonic materials' critical properties for space high power nuclear pumped lasers

    Science.gov (United States)

    Gu, Albert G.; Miller, Mark S.

    1991-01-01

    All space missions require a reliable, compact source of energy. This paper describes preliminary neutronics studies of ``pocket'' reactor concepts employing PuF6 and transplutonic materials as fuels for space high power/energy Nuclear Pumped Lasers (NPLs). Previous research has studied NPL reactor concepts with thin fuel layers, aerosol fuels and gaseous UF6. The total reactor volumes for compact reactors with these types of fuels typically range from 3 m3 to 50 m3. By employing PuF6 and transplutonic fuels at the same low densities, a calculated value for Keff of 1.2 has been achieved for conditions of 900 K and 5 atm, with total reactor volumes of 1.5 m3 for PuF6, 0.51 m3 for Am-242m, 0.58 m3 for Cm-245 and 0.63 m3 for Cf-249.

  18. Perbandingan Kapasitas Pesan pada Steganografi DCT Sekuensial dan Steganografi DCT F5 dengan Penerapan Point Operation Image Enhancement

    Directory of Open Access Journals (Sweden)

    Dian Hafidh Zulfikar

    2016-01-01

        Based on test results that have to be got several conclusions that capacity steganographic message on DCT sequential greater than the DCT F5 steganography either before or after application of the application POIE, stego image quality on DCT steganography F5 better than the sequential DCT steganography well before the application POIE and after application of POIE, both F5 and steganography steganography DCT DCT sequential equally resistant to manipulation of stego image.

  19. Antiferromagnetism in the organic conductor bis-tetramethyltetraselenafulvalene hexafluoroarsenate [(TMTSF)2AsF6]: Static magnetic susceptibility

    DEFF Research Database (Denmark)

    Mortensen, Kell; Tomkiewicz, Yaffa; Bechgaard, Klaus

    1982-01-01

    temperature, evidence for magnetic crossover is observed. The experimental results show (TMTSF)2X, X- = AsF6- and PF6- to be members of a family with quite similar physical properties. The data are discussed on the basis of Overhauser's treatment of itinerant antiferromagnetism.......The anisotropy in the static magnetic susceptibility of bis-tetramethyltetraselenafulvalene hexafluoroarsenate [(TMTSF)2AsF6] has been investigated above and below the metal-to-insulator transition for a range of fields between 0.5 and 30 kG. The results are consistent with the expectations...

  20. Interaction between SiO2 and a KF-KCl-K2SiF6 Melt.

    Science.gov (United States)

    Zaykov, Yurii P; Isakov, Andrey V; Zakiryanova, Irina D; Reznitskikh, Olga G; Chemezov, Oleg V; Redkin, Alexander A

    2014-02-13

    The solubility mechanism of silica in a fluoride-chloride melt has been determined in situ using Raman spectroscopy. The spectroscopy data revealed that the silica solubility process involved Si-O bond breakage and Si-F bond formation. The process results in the formation of silicate complexes, fluorine-bearing silicate complexes, and silicon tetrafluoride in the melt. Mass spectrometry of the vapor phase over the KF-KCl-K2SiF6 and KF-KCl-K2SiF6-SiO2 melts and differential scanning calorimetry coupled with thermal gravimetric analysis of these melts were performed to verify the silica solubility mechanism.

  1. Mesoporous NaYbF4@NaGdF4 core-shell up-conversion nanoparticles for targeted drug delivery and multimodal imaging.

    Science.gov (United States)

    Zhou, Liangjun; Zheng, Xiaopeng; Gu, Zhanjun; Yin, Wenyan; Zhang, Xiao; Ruan, Longfei; Yang, Yanbo; Hu, Zhongbo; Zhao, Yuliang

    2014-08-01

    We developed a facile strategy to obtain a new kind of mesoporous core-shell structured up-conversion nanoparticles (mUCNPs), composed of a NaYbF4:2%Er core and a mesoporous NaGdF4 shell. This mesoporous shell not only enhanced the up-conversion luminescence but also endowed many other functionalities of the nanoparticles such as drug delivery and bio-imaging capabilities. Moreover, after being conjugated with polyethylenimine (PEI) and folic acid (FA), core-shell mUCNPs exhibited good water dispersibility, enhanced drug delivery efficiency, and remarkable targeting ability to cancer cells. To certify the folate receptors (FR)-mediated targeted drug delivery, cell viability assay, cell up-conversion luminescence imaging and flow cytometry analysis were carried out. Furthermore, apart from the application for targeted drug delivery, the as-prepared core-shell mUCNPs could also be employed as the contrast agents for X-ray computed tomography (CT) and magnetic resonance (MR) imaging, because of the strong X-ray attenuation ability of Yb and high longitudinal molar relaxivity (r1) of Gd in the nanoparticles, providing the potential for simultaneously bio-imaging and cancer-targeting therapy.

  2. Synthesis and functionalization of NaGdF4:Yb,Er@NaGdF4 core-shell nanoparticles for possible application as multimodal contrast agents.

    Science.gov (United States)

    Baziulyte-Paulaviciene, Dovile; Karabanovas, Vitalijus; Stasys, Marius; Jarockyte, Greta; Poderys, Vilius; Sakirzanovas, Simas; Rotomskis, Ricardas

    2017-01-01

    Upconverting nanoparticles (UCNPs) are promising, new imaging probes capable of serving as multimodal contrast agents. In this study, monodisperse and ultrasmall core and core-shell UCNPs were synthesized via a thermal decomposition method. Furthermore, it was shown that the epitaxial growth of a NaGdF4 optical inert layer covering the NaGdF4:Yb,Er core effectively minimizes surface quenching due to the spatial isolation of the core from the surroundings. The mean diameter of the synthesized core and core-shell nanoparticles was ≈8 and ≈16 nm, respectively. Hydrophobic UCNPs were converted into hydrophilic ones using a nonionic surfactant Tween 80. The successful coating of the UCNPs by Tween 80 has been confirmed by Fourier transform infrared (FTIR) spectroscopy. Scanning electron microscopy (SEM), powder X-ray diffraction (XRD), photoluminescence (PL) spectra and magnetic resonance (MR) T1 relaxation measurements were used to characterize the size, crystal structure, optical and magnetic properties of the core and core-shell nanoparticles. Moreover, Tween 80-coated core-shell nanoparticles presented enhanced optical and MR signal intensity, good colloidal stability, low cytotoxicity and nonspecific internalization into two different breast cancer cell lines, which indicates that these nanoparticles could be applied as an efficient, dual-modal contrast probe for in vivo bioimaging.

  3. MAGNETIC AND ORBITAL ORDER OF K2AgF4 and Cs2AgF4%K2AgF4和Cs2AgF4的电子结构和磁性

    Institute of Scientific and Technical Information of China (English)

    王广涛; 王东洋; 张琳; 易霞

    2015-01-01

    采用第一性原理计算我们研究了Jahn-Teller(JT)畸变诱导下K2AgF4和Cs2AgF4中的轨道有序和磁性.K2AgF4的基态是层内反铁磁态(AFM2),此时最近邻的Ag2+磁矩互为反平行,而它们的轨道则是相互平行的.Cs2AgF4的基态是层间反铁磁态(AFM1),同一AgF2层中的Ag2+磁矩相互平行,与近邻的AgF2层中Ag2+磁矩互为反平行.这两种体系磁性基态都可以用Goodenough-Kanamori规则进行很好的解释.

  4. Ab Initio Investigations of the C2F4S Isomers and of Their Interconversions

    DEFF Research Database (Denmark)

    Shim, Irene; Vallano-Lorenzo, Sandra; Lisbona-Martin, Pilar

    2003-01-01

    The transition states and the activation energies for the unobserved isomerization reactions between the three possible C2F4S isomers with divalent sulfur, trifluorothioacetyl fluoride 1, tetrafluorothiirane 2, and trifluoroethenesulfenyl fluoride 3, have been determined by ab initio Hartree-Fock...

  5. Evidence of low dimensional ion transport in mechanosynthesized nanocrystalline BaMgF4.

    Science.gov (United States)

    Preishuber-Pflügl, F; Wilkening, M

    2014-07-14

    Mechanochemical milling provides a versatile method for the preparation of nano-sized, defect rich, polycrystalline materials. If ionic materials are considered, the transport parameters of the mobile ions may greatly differ from those of the microcrystalline counterparts prepared by conventional synthesis routes. Little is known about ionic conduction in nanocrystalline materials having crystal structures that offer spatially confined transport pathways. Here, we focused on mechanosynthesized BaMgF4 that combines both nanocrystallinity and anisotropic F(-) transport. The preparation of nanocrystalline BaMgF4 is presented as a facile and rapid one-pot procedure. The reaction was followed by X-ray diffraction and high-resolution (19)F nuclear magnetic resonance (NMR) spectroscopy. NMR helped prove the formation of X-ray amorphous compounds as well as the transformation of the starting materials into the final product BaMgF4. Most importantly, besides enhanced conduction properties compared to a single crystal, our broadband impedance spectra reveal characteristics pointing to anisotropic (low dimensional) ion transport processes even in the nanocrystalline form of BaMgF4.

  6. 28 CFR 55.5 - Coverage under section 4(f)(4).

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Coverage under section 4(f)(4). 55.5 Section 55.5 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) IMPLEMENTATION OF THE PROVISIONS OF THE VOTING RIGHTS ACT REGARDING LANGUAGE MINORITY GROUPS Nature of Coverage § 55.5 Coverage under...

  7. Advanced aircraft analysis of an F-4 Phantom on a reinforced concrete building

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyoungsoo, E-mail: kylee@pvamu.edu [Center for Energy and Environmental Sustainability, Prairie View A and M University, Prairie View, TX 77446 (United States); Jung, Jae-Wook, E-mail: jaewook1987@kaist.ac.kr [Department of Civil and Environmental Engineering, KAIST, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Hong, Jung-Wuk, E-mail: jwhong@alum.mit.edu [Department of Civil and Environmental Engineering, KAIST, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2014-07-01

    Highlights: • Aircraft impact analyses are performed using the missile-target interaction method. • Three types of FE models of a F4-Phantom aircraft considering the fuel mass effect are considered with erosion effect. • The aircraft impact models are verified through the comparative studies with experimental data. • The parametric studies on the fictitious nuclear concrete containment wall are investigated. • The SPH or Hybrid models show severe damage to the deformable constrained concrete wall than does Lagrangian based model. - Abstract: The nonlinear dynamic fracture and collapse characteristics of an F-4 Phantom aircraft under an extreme load caused by the impact of an F-4 Phantom are investigated. Three types of FE models considering the fuel mass effect are developed to investigate the superiority of the developed model. A rigid wall impact test is conducted to determine the material properties and the eroding failure criteria. The impact forces exerted by the aircraft against mounted thick concrete walls are then verified by comparing the results here with earlier experimental data obtained from an actual-scale F-4 Phantom aircraft impact test conducted by Sandia National Laboratory. Validation of the methodology is further investigated by extending the comparative studies to a constrained thin concrete wall similar to the type used in nuclear power plant containment buildings. The experimental and simulation results are also analyzed and discussed.

  8. An electronic control for an electrohydraulic active control landing gear for the F-4 aircraft

    Science.gov (United States)

    Ross, I.

    1982-01-01

    A controller for an electrohydraulic active control landing gear was developed for the F-4 aircraft. A controller was modified for this application. Simulation results indicate that during landing and rollout over repaired bomb craters the active gear effects a force reduction, relative to the passive gear, or approximately 70%.

  9. Generalized WDVV equations for F4 pure N=2 super-Yang–Mills theory

    NARCIS (Netherlands)

    Hoevenaars, L.K.; Kersten, P.H.M.; Martini, R.

    2001-01-01

    An associative algebra of holomorphic differential forms is constructed associated with pure N=2 super-Yang–Mills theory for the Lie algebra F4. Existence and associativity of this algebra, combined with the general arguments in the work of Marshakov, Mironov and Morozov, proves that the prepotentia

  10. Generalized WDVV equations for $F_4$ pure N=2 Super-Yang-Mills theory

    NARCIS (Netherlands)

    Hoevenaars, L.K.; Kersten, P.H.M.; Martini, R.

    2000-01-01

    An associative algebra of holomorphic differential forms is constructed associated with pure N=2 Super-Yang-Mills theory for the Lie algebra $F_4$ . Existence and associativity of this algebra, combined with the general arguments in the work of Marshakov, Mironov and Morozov, proves that the prepote

  11. In vitro Reduction of Dental Erosion by Low-Concentration TiF4 Solutions

    NARCIS (Netherlands)

    Vieira, A. M.; Ruben, J. L.; Bronkhorst, E. M.; Huysmans, M. C. D. N. J. M.

    2011-01-01

    The aims of this study were to compare daily versus single applications of low-concentration TiF4 solutions for reduction of enamel erosion and to evaluate the enamel surface loss due to application of these solutions. Sixty bovine enamel samples were randomly divided into 2 groups: single versus

  12. Growth and spectroscopic analysis of Tm, Ho:KY F4

    Science.gov (United States)

    Sani, Elisa; Toncelli, Alessandra; Tonelli, Mauro; Traverso, Francesca

    2004-01-01

    Single crystals of lasing Tm,Ho:KY F4 were successfully grown by the Czochralski method. A complete polarized spectroscopic investigation is given and it is shown that the inhomogeneous broadening of the spectra of rare earth ions can be ascribed to a disordered character of the KYF crystalline structure.

  13. Vapour-phase crystallisation of silica from SiF4-bearing volcanic gases

    Directory of Open Access Journals (Sweden)

    M. H. G. Jacobs

    2005-06-01

    Full Text Available Thermodynamic modelling of magmatic gases shows that SiF4 may be an important F-bearing species at the high pressures typical of magma reservoirs. Upon decompression during degassing, SiF4 will react with water vapour to form HF and silica. Common magmatic gases of high-T fumaroles seem to contain too little SiF4 to be a significant source of silica, except if extremely large amounts of gas percolate through a small volume of rock, as is the case in lava domes. Only if fluorine contents of the gases exceed 1 mol% detectable amounts of silica may be formed, but such high fluorine contents have not yet been observed in natural gases. Alternatively, silica may be formed by heating of cool SiF4-rich gases circulating in cooling lava bodies. We suggest that these mechanisms may be responsible for the deposition of crystalline silica, most probably cristobalite, observed in vesicles in lavas from Lewotolo volcano (Eastern Sunda Arc, Indonesia. Silica occurs as vapour-crystallised patches in vesicles, and is sometimes associated with F-phlogopite, which further supports F-rich conditions during deposition. Because of the connection between F-rich conditions and high-K volcanism, we propose that late-stage gaseous transport and deposition of silica may be more widespread in K-rich volcanoes than elsewhere, and long-term exposure to ash from eruptions of such volcanoes could therefore carry an increased risk for respiratory diseases. The dependence of SiF4/HF on temperature reported here differs from the current calibration used for temperature measurements of fumarolic gases by remote sensing techniques, and we suggest an updated calibration.

  14. Structural aspects of dog allergies: the crystal structure of a dog dander allergen Can f 4.

    Science.gov (United States)

    Niemi, Merja H; Rytkönen-Nissinen, Marja; Jänis, Janne; Virtanen, Tuomas; Rouvinen, Juha

    2014-09-01

    Four out of six officially recognized dog allergens are members of the lipocalin protein family. So far, a three-dimensional structure has been determined for only one dog allergen, Can f 2, which is a lipocalin protein. We present here the crystal structure of a second lipocalin allergen from dog, a variant of Can f 4. Moreover, we have compared and analyzed the structures of these two weakly homologous (amino acid identity 21%) dog allergens. The size and the amino acid composition of the ligand-binding pocket indicate that Can f 4 is capable of binding only relatively small hydrophobic molecules which are different from those that Can f 2 is able to bind. The crystal structure of Can f 4 contained both monomeric and dimeric forms of the allergen, suggesting that Can f 4 is able to form transient (weak) dimers. The existence of transient dimers in solution was confirmed by use of native mass spectrometry. The dimeric structure of Can f 4 is formed when the ends of four β-strands are packed against the same strands from the second monomer. The residues in the interface are mainly hydrophobic and the formation of the dimer is similar to the major horse allergen Equ c 1. Interestingly, the crystal structure of dog Can f 2 has been reported to show a different type of dimer formation. The capability of these allergens to form dimers may be important for the development of immediate allergic reaction (mast cell activation) because oligomeric allergens can effectively present multivalent epitopes.

  15. The hydrogen storage properties of Mg-Li-Al composite system catalyzed by K2ZrF6

    Science.gov (United States)

    Yap, F. A. Halim; Ismail, M.

    2017-05-01

    The effect of the K2ZrF6 catalyst on the hydrogen storage properties of the 4MgH2-LiAlH4 composite was studied for the first time. The onset dehydrogenation temperature of the 4MgH2-LiAlH4-K2ZrF6 composite was reduced to approximately 95 °C and 250 °C for the first two dehydrogenation stages; these values were lower by 40 °C and 25 °C compared with the undoped composite. Desorption kinetics measurement revealed that K2ZrF6-doped 4MgH2-LiAlH4 released 3.0 wt% hydrogen in 20 min, whereas the undoped composite only released 2.0 wt% hydrogen within the same time. The activation energy for MgH2-relevant decomposition in the 4MgH2-LiAlH4 composite was reduced from 129.8 kJ/mol to 102.9 kJ/mol after the addition of the K2ZrF6 catalyst. The X-ray diffraction spectra displayed the formation of novel peaks of KH, Al3Zr and LiF after the de/rehydrogenation processes. These species functioned as active species and played a catalytic role in enhancing the dehydrogenation properties of the Mg-Li-Al composite.

  16. Aluminothermic Reduction of K2ZrF6 for Preparation of Al-Zr Master Alloy

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    This paper summarizes a process for the preparation of Al-5%Zr master alloy by the reduction of K2ZrF6 with aluminium. The reduction in grain size of aluminium by addition of known quantity of master alloy is also studied.

  17. pRB and E2F4 play distinct cell-intrinsic roles in fetal erythropoiesis.

    Science.gov (United States)

    Zhang, Jing; Lee, Eunice Y; Liu, Yangang; Berman, Seth D; Lodish, Harvey F; Lees, Jacqueline A

    2010-01-15

    The retinoblastoma tumor suppressor protein pRB functions, at least in part, by directly binding to and modulating the activity of the E2F transcription factors. Previous studies have shown that both E2F4 and pRB play important roles in fetal erythropoiesis. Given that these two proteins interact directly we investigated the overlap of E2F4 and pRB function in this process by analyzing E2f4(-/-), conditional Rb knockout (Rb(1lox/1lox)), and compound E2f4(-/-);Rb(1lox/1lox) embryos. At E15.5 E2f4(-/-) and Rb(1lox/1lox) fetal erythroid cells display distinct abnormalities in their differentiation profiles. When cultured in vitro, both E2f4(-/-) and Rb(1lox/1lox) erythroid cells show defects in cell cycle progression. Surprisingly, analysis of cell cycle profiling suggests that E2F4 and pRB control cell cycle exit through different mechanisms. Moreover, only pRB, but not E2F4, promotes cell survival in erythroid cells. We observed an additive rather than a synergistic impact upon the erythroid defects in the compound E2f4(-/-);Rb(1lox/1lox) embryos. We further found that fetal liver macrophage development is largely normal regardless of genotype. Taken together, our results show that E2F4 and pRB play independent cell-intrinsic roles in fetal erythropoiesis.

  18. Oral administration of a select mixture of Bacillus probiotics generates Tr1 cells in weaned F4ab/acR pigs challenged with an F4+ ETEC/VTEC/EPEC strain

    DEFF Research Database (Denmark)

    Zhou, Dong; Zhang, Wei; Wang, Meng-Ling

    2015-01-01

    Although breeding of F4 receptor − negative (F4R−) pigs may prevent post-weaning diarrhea, the underlying immunity is poorly understood. Here, various doses of a Bacillus licheniformis and Bacillus subtilis mixture (BLS-mix) were orally administered to F4ab/acR− pigs for 1 week before F4 (K88) − ...... of BLS-mix during episodes of intestinal inflammation that is caused by enteric pathogens might prohibit clearance of the pathogen. Select probiotic mixtures may allow for tailoring strategies to prevent infectious diseases....

  19. [Determination of ellagic acid, flavonoids and goshonoside-F5 in Rubi Fructus by HPLC].

    Science.gov (United States)

    He, Jian-Ming; Sun, Nan; Wu, Wen-Dan; Fan, Li-Jiao; Guo, Mei-Li

    2013-12-01

    High-performance liquid chromatographic coupled with variable wavelength detection (HPLC-VWD) has been developed for simultaneous determination of 5 analytes including ellagic acid, quercetin, kaempferol-3-O-beta-D-rutinoside, tiliroside and kaempferol, and high-performance liquid chromatographic with an evaporative light scattering detector (HPLC-ELSD) has been established to determine goshonoside-F5 in extract of Rubi Fructus. Chromatographic separations were carried out on an Agilent ZORBAX SB-C18 column (4.6 mm x 250 mm, 5.0 microm). All calibration curves of reference standards revealed good linearity (R2 > 0.999 5) within the concentration ranges tested. The method limits of detection ranged 0.297-90.144 ng and the method limits ofquantitation ranged 0.990-300.480 ng, respectively. Recoveries of 6 analytes were from 97.11% to 101.7%, with RSD less than 2.1%. The result shows that amounts of the 6 analytes in the samples from 16 localities were found to be different. The higher latitude of growing environment, the more ellagic acid in herb. The content of total flavonoids in sample from east localities were higher than that in middle and west localities, and the content of goshonoside-F5 in Bozhou, Anhui province was higher than others. This method was found to be simple, accurate, sensitive with good repeatability. Those results might serve as a sound foundation for further study, quality control and application of Rubi Fructus.

  20. Responses of mirror neurons in area F5 to hand and tool grasping observation.

    Science.gov (United States)

    Rochat, Magali J; Caruana, Fausto; Jezzini, Ahmad; Escola, Ludovic; Intskirveli, Irakli; Grammont, Franck; Gallese, Vittorio; Rizzolatti, Giacomo; Umiltà, Maria Alessandra

    2010-08-01

    Mirror neurons are a distinct class of neurons that discharge both during the execution of a motor act and during observation of the same or similar motor act performed by another individual. However, the extent to which mirror neurons coding a motor act with a specific goal (e.g., grasping) might also respond to the observation of a motor act having the same goal, but achieved with artificial effectors, is not yet established. In the present study, we addressed this issue by recording mirror neurons from the ventral premotor cortex (area F5) of two monkeys trained to grasp objects with pliers. Neuron activity was recorded during the observation and execution of grasping performed with the hand, with pliers and during observation of an experimenter spearing food with a stick. The results showed that virtually all neurons responding to the observation of hand grasping also responded to the observation of grasping with pliers and, many of them to the observation of spearing with a stick. However, the intensity and pattern of the response differed among conditions. Hand grasping observation determined the earliest and the strongest discharge, while pliers grasping and spearing observation triggered weaker responses at longer latencies. We conclude that F5 grasping mirror neurons respond to the observation of a family of stimuli leading to the same goal. However, the response pattern depends upon the similarity between the observed motor act and the one executed by the hand, the natural motor template.

  1. Characterization of Active Main Belt Object P/2012 F5 (Gibbs): A Possible Impacted Asteroid

    CERN Document Server

    Stevenson, R; Bauer, J M; Masiero, J R; Mainzer, A K

    2012-01-01

    In this work we characterize the recently discovered active main belt object P/2012 F5 (Gibbs), which was discovered with a dust trail > 7' in length in the outer main belt, 7 months prior to aphelion. We use optical imaging obtained on UT 2012 March 27 to analyze the central condensation and the long trail. We find nuclear B-band and R-band apparent magnitudes of 20.96 and 19.93 mag, respectively, which give an upper limit on the radius of the nucleus of 2.1 km. The geometric cross-section of material in the trail was ~ 4 x 10^8 m^2, corresponding to a dust mass of ~ 5 x 10^7 kg. Analysis of infrared images taken by the Wide-Field Infrared Survey Explorer in September 2010 reveals that the object was below the detection limit, suggesting that it was less active than it was during 2012, or possibly inactive, just 6 months after it passed through perihelion. We set a 1-sigma upper limit on its radius during this time of 2.9 km. P/2012 F5 (Gibbs) is dynamically stable in the outer main belt on timescales of ~ 1...

  2. Discovery of a young asteroid cluster associated with P/2012~F5 (Gibbs)

    CERN Document Server

    Novakovic, Bojan; Cellino, Alberto; Micheli, Marco; Pedani, Marco

    2014-01-01

    We present the results of our search for a dynamical family around the active asteroid P/2012F5 (Gibbs). By applying the hierarchical clustering method, we discover an extremely compact 9-body cluster associated with P/2012F5. The statistical significance of this newly discovered Gibbs cluster is estimated to be >99.9%, strongly suggesting that its members share a common origin. The cluster is located in a dynamically cold region of the outer main-belt at a proper semi-major axis of about 3.005 AU, and all members are found to be dynamically stable over very long time-scales. Backward numerical orbital integrations show that the age of the cluster is only 1.5 $\\pm$ 0.1 Myr. Taxonomic classifications are unavailable for most of the cluster members, but SDSS spectrophotometry available for two cluster members indicate that both appear to be $Q$-type objects. We also estimate a lower limit of the size of the parent body to be about 10 km, and find that the impact event which produced the Gibbs cluster is interme...

  3. Direct visualization of gastrointestinal tract with lanthanide-doped BaYbF5 upconversion nanoprobes.

    Science.gov (United States)

    Liu, Zhen; Ju, Enguo; Liu, Jianhua; Du, Yingda; Li, Zhengqiang; Yuan, Qinghai; Ren, Jinsong; Qu, Xiaogang

    2013-10-01

    Nanoparticulate contrast agents have attracted a great deal of attention along with the rapid development of modern medicine. Here, a binary contrast agent based on PAA modified BaYbF5:Tm nanoparticles for direct visualization of gastrointestinal (GI) tract has been designed and developed via a one-pot solvothermal route. By taking advantages of excellent colloidal stability, low cytotoxicity, and neglectable hemolysis of these well-designed nanoparticles, their feasibility as a multi-modal contrast agent for GI tract was intensively investigated. Significant enhancement of contrast efficacy relative to clinical barium meal and iodine-based contrast agent was evaluated via X-ray imaging and CT imaging in vivo. By doping Tm(3+) ions into these nanoprobes, in vivo NIR-NIR imaging was then demonstrated. Unlike some invasive imaging modalities, non-invasive imaging strategy including X-ray imaging, CT imaging, and UCL imaging for GI tract could extremely reduce the painlessness to patients, effectively facilitate imaging procedure, as well as rationality economize diagnostic time. Critical to clinical applications, long-term toxicity of our contrast agent was additionally investigated in detail, indicating their overall safety. Based on our results, PAA-BaYbF5:Tm nanoparticles were the excellent multi-modal contrast agent to integrate X-ray imaging, CT imaging, and UCL imaging for direct visualization of GI tract with low systemic toxicity.

  4. Thermodynamic assessment of the LiF–ThF4–PuF3–UF4 system

    NARCIS (Netherlands)

    Capelli, E.; Benes, O.; Konings, R.J.M.

    2015-01-01

    The LiF–ThF4–PuF3–UF4 system is the reference salt mixture considered for the Molten Salt Fast Reactor (MSFR) concept started with PuF3. In order to obtain the complete thermodynamic description of this quaternary system, two binary systems (ThF4–PuF3 and UF4–PuF3) and two ternary systems (LiF–ThF4

  5. Non-pathogenic Rhizobium radiobacter F4 deploys plant beneficial activity independent of its host Piriformospora indica.

    Science.gov (United States)

    Glaeser, Stefanie P; Imani, Jafargholi; Alabid, Ibrahim; Guo, Huijuan; Kumar, Neelendra; Kämpfer, Peter; Hardt, Martin; Blom, Jochen; Goesmann, Alexander; Rothballer, Michael; Hartmann, Anton; Kogel, Karl-Heinz

    2016-04-01

    The Alphaproteobacterium Rhizobium radiobacter F4 (RrF4) was originally characterized as an endofungal bacterium in the beneficial endophytic Sebacinalean fungus Piriformospora indica. Although attempts to cure P. indica from RrF4 repeatedly failed, the bacterium can easily be grown in pure culture. Here, we report on RrF4's genome and the beneficial impact the free-living bacterium has on plants. In contrast to other endofungal bacteria, the genome size of RrF4 is not reduced. Instead, it shows a high degree of similarity to the plant pathogenic R. radiobacter (formerly: Agrobacterium tumefaciens) C58, except vibrant differences in both the tumor-inducing (pTi) and the accessor (pAt) plasmids, which can explain the loss of RrF4's pathogenicity. Similar to its fungal host, RrF4 colonizes plant roots without host preference and forms aggregates of attached cells and dense biofilms at the root surface of maturation zones. RrF4-colonized plants show increased biomass and enhanced resistance against bacterial leaf pathogens. Mutational analysis showed that, similar to P. indica, resistance mediated by RrF4 was dependent on the plant's jasmonate-based induced systemic resistance (ISR) pathway. Consistent with this, RrF4- and P. indica-induced pattern of defense gene expression were similar. In clear contrast to P. indica, but similar to plant growth-promoting rhizobacteria, RrF4 colonized not only the root outer cortex but also spread beyond the endodermis into the stele. On the basis of our findings, RrF4 is an efficient plant growth-promoting bacterium.

  6. Distinct phosphorylation events regulate p130- and p107-mediated repression of E2F-4

    DEFF Research Database (Denmark)

    Farkas, Thomas; Hansen, Klaus; Holm, Karin;

    2002-01-01

    sites selectively targeted by cyclin D-Cdk4(6) kinases. Here we assessed the effects of alanine substitution at the individual or combined Cdk4(6)-specific sites in p130, compared with homologous sites in p107 (Thr(369)/Ser(650)/Ser(964)). In U-2-OS cells, the triple p107(DeltaCdk4)* mutant strongly...... inhibited E2F-4 activity and imposed a G(1) arrest resistant to cyclin D1 coexpression. In contrast, the p130(DeltaCdk4) mutant still responded to cyclin D1, suggesting the existence of additional phosphorylation sites critical for E2F-4 regulation. Extensive mutagenesis, sensitive E2F reporter assays...

  7. Hydrothermal synthesis, characterization and luminescent properties of lanthanide-doped NaLaF$_4$ nanoparticles

    Indian Academy of Sciences (India)

    JIGMET LADOL; HEENA KHAJURIA; SONIKA KHAJURIA; HAQ NAWAZ SHEIKH

    2016-08-01

    Nanoparticles of sodium lanthanum (III) fluoride-doped and co-doped with Eu$^{3+}/Tb$^{3+}$ were prepared by the hydrothermal method using citric acid as structure-directing agent. Structural aspects and optical properties of synthesized nanoparticles were studied by powder X-ray diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectra (EDS), particle size by dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectrum and photoluminescence (PL) techniques. Nanoparticles consist of well-crystallized hexagonal phase and the average crystallite size for undoped and doped-NaLaF$_4$ nanoparticles are in the range of 20–22 nm. TEM images show that nanoparticles have cylindrical shape and crystalline nature of nanoparticles was confirmed by SAED patterns. Downconversion(DC) luminescent properties of doped NaLaF4 were also investigated and impact of co-doping has been explored.

  8. Dipolar and Non-Dipolar Interactions in LiTbF4

    DEFF Research Database (Denmark)

    Holmes, L. M.; Als-Nielsen, Jens Aage; Guggenheim, H. J.

    1975-01-01

    The magnetic interactions in LiTbF4 have been studied in measurements of the quasielastic scattering of neutrons from the paramagnetic crystal. Scattering data have been collected at a temperature T=18.6 K, which is 6.5 times the Curie temperature of LiTbF4, and have been least-squares fitted...... with an expression for the scattering cross section which includes, in addition to the dominant dipolar coupling, two exchange parameters J1 and J2 describing the nondipolar coupling between nearest- and next-nearest-neighbor Tb3+ ions, respectively. The derived exchange parameters are J1/k=-0.26±0.09 K and J2/k=+0...

  9. Normal Subgroup Growth of Linear Groups: the (G2; F4;E8)-Theorem

    CERN Document Server

    Larsen, Michael

    2011-01-01

    Let G be a finitely generated group and M_n(G) the number of its normal subgroup subgroups of index at most n. For linear groups G we show that M_n(G) can grow polynomially in n only if the semisimple part of the Zariski closure of G has simple components only of type G2, F4 or E8 (and in this case indeed this can happened!)

  10. Dependence of Temperature on Upconversion Emission of YLiF4∶Er3+

    Institute of Scientific and Technical Information of China (English)

    赵谡玲; 徐征; 侯延冰; 裴晓将; 徐叙瑢

    2003-01-01

    Intense upconversion emissions of YLiF4∶Er3+ synthesized by hydrothermal method were obtained. The upconversion intensity decreases with the increase of environment temperature. In different temperature, the upconversion mechanism is different. At room temperature, the green upconversion mechanism is the combination of two-photon process and three-photon process, and the red upconversion mechanism is two-photon process.

  11. Ab initio molecular dynamics simulations of the Li4F4 cluster

    Science.gov (United States)

    Heidenreich, A.; Sauer, J.

    1995-12-01

    Molecular dynamics simulations have been performed directly on the ab initio potential energy surface of Li4F4, which was generated within the Hartree-Fock approximation using a Gaussian basis set (split valence contraction). Trajectories at different temperatures yield the temperature dependence of the infrared spectra and the photoelectron spectra. For the infrared spectra comparison is made with MD results using a shell model ion pair potential function.

  12. Mechanical synthesis and structural properties of the fast fluoride-ion conductor PbSnF4

    Science.gov (United States)

    Fujisaki, Fumika; Mori, Kazuhiro; Yonemura, Masao; Ishikawa, Yoshihisa; Kamiyama, Takashi; Otomo, Toshiya; Matsubara, Eiichiro; Fukunaga, Toshiharu

    2017-09-01

    A fluoride-ion conductor, γ-PbSnF4, was synthesized by the mechanical milling. In addition, β-PbSnF4 was obtained by aging the γ-PbSnF4 at 473 K. The electrical conductivity of β-PbSnF4 is relatively higher than that of γ-PbSnF4 at 298 K. The crystal structure analysis of γ- and β-PbSnF4 was carried out using neutron diffraction data. From the obtained occupancies, fluoride ions were located at the Fγ(1) normal site (62%) and Fγ(2) interstitial site (38%) in γ-PbSnF4 and the Fβ(1) normal site (31%), Fβ(2) normal site (25%), and Fβ(3) interstitial site (44%) in β-PbSnF4. In particular, the number of fluoride ions at the F interstitial site increased after the γ-to-β phase transition: 38% at Fγ(2) to 44% at Fβ(3). It is most likely that the ratio of fluoride ions to vacancies (or the effective carrier concentration) was optimized in the ;-Fβ(1)-Fβ(3)-Fβ(3)-Fβ(1)-; conduction pathways of fluoride ions in β-PbSnF4.

  13. 100 Area soil washing: Bench scale tests on 116-F-4 pluto crib soil

    Energy Technology Data Exchange (ETDEWEB)

    Field, J.G.

    1994-06-10

    The Pacific Northwest Laboratory conducted a bench-scale treatability study on a pluto crib soil sample from 100 Area of the Hanford Site. The objective of this study was to evaluate the use of physical separation (wet sieving), treatment processes (attrition scrubbing, and autogenous surface grinding), and chemical extraction methods as a means of separating radioactively-contaminated soil fractions from uncontaminated soil fractions. The soil washing treatability study was conducted on a soil sample from the 116-F-4 Pluto Crib that had been dug up as part of an excavation treatability study. Trace element analyses of this soil showed no elevated concentrations above typically uncontaminated soil background levels. Data on the distribution of radionuclide in various size fractions indicated that the soil-washing tests should be focused on the gravel and sand fractions of the 116-F-4 soil. The radionuclide data also showed that {sup 137}Cs was the only contaminant in this soil that exceeded the test performance goal (TPG). Therefore, the effectiveness of subsequent soil-washing tests for 116-F-4 soil was evaluated on the basis of activity attenuation of {sup 137}Cs in the gravel- and sand-size fractions.

  14. Effect of Sr doping in layered Eu3Bi2S4F4 superconductor

    Science.gov (United States)

    Zhang, Pan; Zhai, Hui-Fei; Wang, Zhen; Chen, Jian; Feng, Chun-Mu; Cao, Guang-Han; Xu, Zhu-An

    2017-01-01

    We report the effect of Sr-doping in the BiS2-based superconductor {{Eu}}3-xSr x Bi2S4F4. Eu3Bi2S4F4 is a self-doped compound with a mixed Eu valence state. By the partial substitution of Sr for Eu, T c gradually decreases and superconductivity disappears above 0.3 K when x\\gt 1.0. Magnetic-susceptibility and specific-heat measurements reveal that Sr substitution leads to a decrease in both Eu2+ and Eu3+ populations. The decreased Eu3+ population, and the corresponding lower charge carrier density, may be the main origin for the suppression of superconductivity. In addition, we find a significant increase in the Sommerfeld coefficient {γ }0 upon Sr doping, which may be due to the Kondo effect between the magnetic moments (associated to Eu2+ ions) and the conducting electrons. This work implies that the Kondo effect could compete with superconductivity in Eu3Bi2S4F4.

  15. DLR-F6/FX2B翼身组合体构型高阶精度数值模拟%High-order accuracy numerical simulation of DLR-F6/FX2B wing-body configuration

    Institute of Scientific and Technical Information of China (English)

    王运涛; 孟德虹; 孙岩; 张玉伦; 李伟

    2016-01-01

    基于雷诺平均Navier-Stokes (RANS)方程和结构网格技术,采用五阶空间离散精度的加权紧致非线性格式(WCNS)和剪切应力输运(SST)两方程湍流模型,开展了DLR-F6和DLR F6 FX2B 2种翼身组合体构型的高阶精度数值模拟,计算外形来自AIAA第三届阻力预测研讨会.主要目的是确认WCNS模拟跨声速典型运输机构型和预测局部构型变化引起的气动特性变化量的能力.在固定升力系数条件下,采用粗、中、细3套网格开展了网格收敛性研究,从气动力系数、压力系数分布、表面流态等方面研究了网格规模对DLR-F6和DLR-F6_FX2B翼身组合体数值模拟结果的影响;采用中等网格开展了来流迎角对2种翼身组合体气动特性的影响研究.通过与National Transonic Facility (NTF)的试验结果和CFL3D的计算结果对比,表明采用高阶精度计算方法得到了网格收敛的数值模拟结果,较好地模拟了DLR-F6翼身组合体局部修型引起的微小气动特性变化和翼身结合部流动特性的差异.

  16. A raman study of hydrostatic pressure induced phase transitions in Rb2KInF6 crystals

    Science.gov (United States)

    Vtyurin, A. N.; Krylov, A. S.; Goryainov, S. V.; Krylova, S. N.; Oreshonkov, A. S.; Voronov, V. N.

    2012-05-01

    The Raman spectra of the elpasolite (Rb2KInF6) crystal have been studied in the pressure range from 0 to 5.3 GPa at a temperature of 295 K. A phase transition at a pressure of approximately 0.9 GPa has been found. An analysis of the variations in the spectral parameters has led to the conclusion that the phase transition to a distorted phase is accompanied by the doubling of the volume of the primitive cell of the initial cubic phase. Numerical calculations of the lattice dynamics in the Rb2KInF6 crystal have been performed. The numerical simulation has established that the phase transition at a pressure of 0.9 GPa is associated with condensation of the F lg mode. A probable high-pressure phase is the phase with space group C2/ m.

  17. Five Coordinate Platinum(II in [Pt(bpy(cod(Me][SbF6]: A Structural and Spectroscopic Study

    Directory of Open Access Journals (Sweden)

    Axel Klein

    2015-05-01

    Full Text Available The five coordinate organoplatinum complex [Pt(bpy(cod(Me][SbF6] (cod = 1,5-cyclooctadiene, bpy = 2,2’-bipyridine was obtained reacting [Pt(cod(MeCl] with Ag[SbF6] and bpy and characterized by multiple spectroscopy (IR and NMR and single crystal XRD. Although the application of the τ values for the discrimination between trigonal bipyramidal vs. square pyramidal coordination fails, the molecular structure can be unequivocally described as basally-distorted trigonal bipyramidal. Detailed multinuclear NMR spectroscopy in solution at ambient temperature gives strong evidence for the same structure; corresponding low-temperature measurements down to −70 °C revealed no marked dynamic processes.

  18. ELECTRON CORRELATION-EFFECTS ON THE F(6)-MANIFOLD OF THE EU3+ IMPURITY IN BA2GDNBO6

    NARCIS (Netherlands)

    DIJKSTRA, F; DEJONG, WA; NIEUWPOORT, WC

    1995-01-01

    The effects of atomic and molecular electron correlation and Gaunt interaction on the transition energies between the D-5(0) and F-7(1,2) levels, arising from the (4)f(6) State of the europium ion, have been studied for the ion and for the [EuO6](9-) cluster as it is found in the Ba2GdNbO6 crystal.

  19. Multi-phonon dynamics of the ultra-fast photoinduced transition of (EDO-TTF)2SbF6

    Science.gov (United States)

    Lorenc, Maciej; Moisan, Nicolas; Servol, Marina; Cailleau, Hervé; Koshihara, Shin-ya; Maesato, Mitsuhiko; Shao, Xiangfeng; Nakano, Yoshiaki; Yamochi, Hideki; Saito, Gunzi; Collet, Eric

    2009-02-01

    We report here the first observation of the photoinduced insulating-to-metal phase transition in the (EDO-TTF)2SbF6 salt, which occurs on the picosecond time-scale. The time-resolved optical experiments performed with 80 fs time-resolution demonstrate that the dynamical process involves several low-frequency phonons, as the crystalline structure is destabilized upon laser excitation.

  20. Characterisation of Alternaria alternata manganese-dependent superoxide dismutase, a cross-reactive allergen homologue to Asp f 6.

    Science.gov (United States)

    Gabriel, Marta F; Postigo, Idoia; Gutiérrez-Rodríguez, Antonio; Suñén, Ester; Guisantes, Jorge; Tomaz, Cândida T; Martínez, Jorge

    2015-07-01

    It is well known that Alternaria alternata presents a significant level of allergenic cross-reactivity with several other phylogenetically related and non-related allergenic moulds. To improve the molecular diagnosis, the identification and characterisation of all clinically relevant allergens, including both species-specific and cross-reacting proteins, is required. In this study we report the molecular and immunological characterisation of the A. alternata manganese-dependent superoxide dismutase (Alt a MnSOD) and its cross-reactivity with Asp f 6, a diagnostic marker allergen in allergic bronchopulmonary aspergillosis (ABPA). The cDNA coding for Alt a MnSOD sequence was isolated by RACE and PCR. Alt a MnSOD is a protein of 191 amino acids that presented significant homology and potential cross-reactive epitopes with Asp f 6. The recombinant protein was produced in Escherichia coli and the immunoreactivity was evaluated in patient sera. Immunoblotting analyses showed that seven of sixty-one A. alternata-sensitised patient sera and two ABPA patient sera reacted with the recombinant Alt a MnSOD. The native counterpart contained in both A. alternata and Aspergillus fumigatus extracts inhibited IgE binding to the recombinant molecule. The allergen was named Alt a 14 by the official Allergen nomenclature subcommittee. Thus, Alt a 14 is a relevant allergen in A. alternata sensitisation that may be used to improve diagnostic procedures. Evidence of cross-reactivity between Asp f 6 and Alt a 14-recognition by ABPA patient sera suggest the existence of an Alt a 14-mediated mechanism that, similar to Asp f 6, may be related to the pathogenesis of ABPA. Copyright © 2015 Elsevier GmbH. All rights reserved.

  1. 40 CFR Table F-6 to Subpart F of... - Estimated Mass Concentration Measurement of PM2.5 for Idealized Fine Aerosol Size Distribution

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Estimated Mass Concentration Measurement of PM2.5 for Idealized Fine Aerosol Size Distribution F Table F-6 to Subpart F of Part 53... Equivalent Methods for PM2.5 Pt. 53, Subpt. F, Table F-6 Table F-6 to Subpart F of Part 53—Estimated Mass...

  2. Drag prediction of DLR-F4 from AIAA drag prediction workshop%DLR-F4翼身组合体的阻力计算

    Institute of Scientific and Technical Information of China (English)

    王运涛; 王光学; 洪俊武; 陈作斌

    2003-01-01

    为了考察自行研发的CFD软件的计算能力和阻力计算精度,本文采用LU-SGS方法、MUSCL差分格式和Baldwin-Lomax代数湍流模型,数值模拟了AIAA 阻力计算工作室提供的DLR-F4翼身组合体的绕流流场,综合分析了case1和case2的气动力的计算结果,并与NASA Christopher L. Rumsey采用CFL3D6.0和AFRL/VAAC Don W. Kinsey采用Cobalt60提供的两组计算结果以及AGARD 提供的两种不同风洞的测力试验结果作了比较.计算结果表明,本文计算精度与国外CFD软件相当.为了提高激波/边界层干扰的模拟精度,今后要重点加强湍流模型的应用研究.

  3. GROWTH AND SPECTRAL PROPERTIES OF Er:LiGdF4 CRYSTAL%Er:LiGdF4晶体生长及光谱性能

    Institute of Scientific and Technical Information of China (English)

    李春; 张莹; 张学建; 林海; TONELLI M; Di LIETO A; 王成伟; 曾繁明; 刘景和

    2010-01-01

    采用提拉法生长出掺铒氟化钆锂(Er3+:LiGdF4,Er:LGF)激光晶体.晶体生长工艺参数为:提拉速率为0.16mm/h,晶体转速为3 r/min,冷却速率为lO℃/h.X射线粉末衍射分析表明:晶体属于四方晶系,白钨矿结构,空间群为I41/a,计算的晶胞参数:a=0.5196nm,c=1.102 86nm.晶体的吸收光谱和荧光光谱表明:晶体在659,980nm和1 540nm附近的吸收峰较强,其中在1 540nm处的吸收截面为1.09×10-20cm2.在激光二极管的532nm波长泵浦下,发射峰分别位于995nm和1 530nm附近,其中1 530nm处的半高宽为52nm.

  4. Effect of Na3FeF6 catalyst on the hydrogen storage properties of MgH2.

    Science.gov (United States)

    Sulaiman, N N; Mustafa, N S; Ismail, M

    2016-04-28

    The effects of Na3FeF6 catalyst on the hydrogen storage properties of MgH2 have been studied for the first time. The results showed that for the MgH2 sample doped with 10 wt% Na3FeF6, the onset dehydrogenation temperature decreased to 255 °C, which was 100 °C and 162 °C lower than those of the as-milled and as-received MgH2 sample, respectively. The re/dehydrogenation kinetics were also significantly enhanced compared to the un-doped MgH2. The absorption kinetics showed that the as-milled MgH2 only absorbed 3.0 wt% of hydrogen at 320 °C in 2 min of rehydrogenation, but about 3.6 wt% of hydrogen was absorbed within the same period of time after 10 wt% Na3FeF6 was added to MgH2. The desorption kinetics showed that the MgH2 + 10 wt% Na3FeF6 sample could desorb about 3.8 wt% of hydrogen in 10 min at 320 °C. In contrast, the un-doped MgH2 sample desorbed only 0.2 wt% of hydrogen in the same period of time. The activation energy for the decomposition of the as-milled MgH2 was 167.0 kJ mol(-1), and this value decreased to 75.0 kJ mol(-1) after the addition of 10 wt% Na3FeF6 (a reduction by about 92.0 kJ mol(-1)). It is believed that the in situ formation of the active species of NaMgF3, NaF and Fe during the heating process could enhance the hydrogen storage properties of MgH2, due to the catalytic effects of these new species.

  5. Increasing Polymer Solar Cell Fill Factor by Trap-Filling with F4-TCNQ at Parts Per Thousand Concentration.

    Science.gov (United States)

    Yan, Han; Manion, Joseph G; Yuan, Mingjian; García de Arquer, F Pelayo; McKeown, George R; Beaupré, Serge; Leclerc, Mario; Sargent, Edward H; Seferos, Dwight S

    2016-08-01

    Intrinsic traps in organic semiconductors can be eliminated by trap-filling with F4-TCNQ. Photovoltaic tests show that devices with F4-TCNQ at parts per thousand concentration outperform control devices due to an improved fill factor. Further studies confirm the trap-filling pathway and demonstrate the general nature of this finding.

  6. Optical and scintillation properties of Ce3+ doped LiYF4 and LiLuF4 crystals

    NARCIS (Netherlands)

    Combes, CM; Dorenbos, P; vanEijk, CWE; Pedrini, C; DenHartog, HW; Gesland, JY; Rodnyi, PA

    1997-01-01

    Optical properties of LiYF4:Ce and LiLuF4:Ce were studied viz. optical absorption spectra and X-ray induced emission spectra. The scintillation characteristics of LiYF4:Ce and LiLuF4:Ce were investigated viz. gamma-ray induced pulse height spectra and decay time measurements. A model is presented to

  7. E2F4 modulates differentiation and gene expression in hematopoietic progenitor cells during commitment to the lymphoid lineage.

    Science.gov (United States)

    Enos, Megan E; Bancos, Simona A; Bushnell, Timothy; Crispe, Ian N

    2008-03-15

    The E2F4 protein is involved in gene repression and cell cycle exit, and also has poorly understood effects in differentiation. We analyzed the impact of E2F4 deficiency on early steps in mouse hematopoietic development, and found defects in early hematopoietic progenitor cells that were propagated through common lymphoid precursors to the B and T lineages. In contrast, the defects in erythromyeloid precursor cells were self-correcting over time. This suggests that E2F4 is important in early stages of commitment to the lymphoid lineage. The E2F4-deficient progenitor cells showed reduced expression of several key lymphoid-lineage genes, and overexpression of two erythromyeloid lineage genes. However, we did not detect effects on cell proliferation. These findings emphasize the significance of E2F4 in controlling gene expression and cell fate.

  8. Drag prediction of DLR-F6 configuration with TRIP2.0 software%采用TRIP2.0软件计算DLR-F6构型的阻力

    Institute of Scientific and Technical Information of China (English)

    王运涛; 王光学; 张玉伦

    2009-01-01

    采用"亚跨超CFD软件平台"(TRIP2.0)数值模拟了DLR-F6构型,主要目的是通过计算DLR-F6构型的安装阻力考察TRIP2.0软件的数值模拟精度,并为运输机构型的气动特性计算积累经验.本文数值模拟采用的多块对接网格,测压和测力的试验结果均来自AIAA CFD Drag Prediction Workshop II(DPWII),对比计算结果采用了CFL3D的结果.本文详细研究了网格密度、湍流模型对DLR-F6翼身组合体和翼/身/架/舱复杂组合体两种构型的的总体气动特性和压力分布的影响,计算结果与相应的试验结果取得了较好的一致.本文采用SST两方程模型计算两种构型均得到了网格收敛结果;不同的湍流模型对压差阻力影响较小,对摩擦阻力影响较大;不同的网格密度和湍流模型对压力分布影响较小.

  9. Probing the Pu4 + magnetic moment in PuF4 with 19F NMR spectroscopy

    Science.gov (United States)

    Capan, Cigdem; Dempsey, Richard J.; Sinkov, Sergey; McNamara, Bruce K.; Cho, Herman

    2016-06-01

    The magnetic fields produced by Pu4 + centers have been measured by 19F NMR spectroscopy to elucidate the Pu-F electronic interactions in polycrystalline PuF4. Spectra acquired at applied fields of 2.35 and 7.05 T reveal a linear scaling of the 19F line shape. A model is presented that treats the line broadening and shifts as due to dipolar fields produced by Pu valence electrons in localized noninteracting orbitals. Alternative explanations for the observed line shape involving covalent Pu-F bonding, superexchange interactions, and electronic configurations with enhanced magnetic moments are considered.

  10. Synthesis of [F3S(triple bond)NXeF][AsF6] and structural study by multi-NMR and Raman spectroscopy, electronic structure calculations, and X-ray crystallography.

    Science.gov (United States)

    Smith, Gregory L; Mercier, Hélène P A; Schrobilgen, Gary J

    2007-02-19

    The salt, [F3S(triple bond)NXeF][AsF6], has been synthesized by the reaction of [XeF][AsF6] with liquid N(triple bond)SF3 at -20 degrees C. The Xe-N bonded cation provides a rare example of xenon bound to an inorganic nitrogen base in which nitrogen is formally sp-hybridized. The F3S(triple bond)NXeF+ cation was characterized by Raman spectroscopy at -150 degrees C and by 129Xe, 19F, and 14N NMR spectroscopy in HF solution at -20 degrees C and in BrF5 solution at -60 degrees C. Colorless [F3S(triple bond)NXeF][AsF6] was crystallized from HF solvent at -45 degrees C, and its low-temperature X-ray crystal structure was determined. The Xe-N bond is among the longest Xe-N bonds known (2.236(4) A), whereas the Xe-F bond length (1.938(3) A) is significantly shorter than that of XeF2 but longer than in XeF+ salts. The Xe-F and Xe-N bond lengths are similar to those of HC(triple bond)NXeF+, placing it among the most ionic Xe-N bonds known. The nonlinear Xe-N-S angle (142.6(3)o) contrasts with the linear angle predicted by electronic structure calculations and is attributed to close N...F contacts within the crystallographic unit cell. Electronic structure calculations at the MP2 and DFT levels of theory were used to calculate the gas-phase geometries, charges, bond orders, and valencies of F3S(triple bond)NXeF+ and to assign vibrational frequencies. The calculated small energy difference (7.9 kJ mol-1) between bent and linear Xe-N-S angles also indicates that the bent geometry is likely the result of crystal packing. The structural studies, natural bond orbital analyses, and calculated gas-phase dissociation enthalpies reveal that F3S(triple bond)NXeF+ is among the weakest donor-acceptor adducts of XeF+ with an Xe-N donor-acceptor interaction that is very similar to that of HC(triple bond)NXeF+, but considerably stronger than that of F3S(triple bond)NAsF5. Despite the low dissociation enthalpy of the donor-acceptor bond in F3S(triple bond)NXeF+, 129Xe, 19F, and 14N NMR

  11. A novel repressive E2F6 complex containing the polycomb group protein, EPC1, that interacts with EZH2 in a proliferation-specific manner

    DEFF Research Database (Denmark)

    Attwooll, Claire; Oddi, Sergio; Cartwright, Peter;

    2004-01-01

    activity. Furthermore, we identified the proliferation-specific PcG, EZH2, as an EPC1-interacting protein. Using affinity purification, we showed that E2F6, DP1, EPC1, EZH2, and Sin3B co-elute, suggesting the identification of a novel E2F6 complex that exists in vivo in both normal and transformed human...

  12. Satellites of Xe transitions induced by infrared active vibrational modes of CF4 and C2F6 molecules.

    Science.gov (United States)

    Alekseev, Vadim A; Schwentner, Nikolaus

    2011-07-28

    Absorption and luminescence excitation spectra of Xe/CF(4) mixtures were studied in the vacuum UV region at high resolution using tunable synchrotron radiation. Pressure-broadened resonance bands and bands associated with dipole-forbidden states of the Xe atom due to collision-induced breakdown of the optical selection rules are reported. The spectra display in addition numerous satellite bands corresponding to transitions to vibrationally excited states of a Xe-CF(4) collisional complex. These satellites are located at energies of Xe atom transition increased by one quantum energy in the IR active v(3) vibrational mode of CF(4) (v(3) = 1281 cm(-1)). Satellites of both resonance and dipole-forbidden transitions were observed. Satellites of low lying resonance states are spectrally broad bands closely resembling in shape their parent pressure-broadened resonance bands. In contrast, satellites of dipole-forbidden states and of high lying resonance states are spectrally narrow bands (FWHM ∼10 cm(-1)). The satellites of dipole-forbidden states are orders of magnitude stronger than transitions to their parent states due to collision-induced breakdown of the optical selection rules. These satellites are attributed to a coupling of dipole-forbidden and resonance states induced by the electric field of the transient CF(4) (v(3) = 0 ↔ v(3) = 1) dipole. Similar satellites are present in spectra of Xe/C(2)F(6) mixtures where these bands are induced by the IR active v(10) mode of C(2)F(6). Transitions to vibrationally excited states of Xe-CF(4)(C(2)F(6)) collision pairs were also observed in two-photon LIF spectra.

  13. Immunogenicity of recombinant F4 (K88) fimbrial adhesin FaeG expressed in tobacco chloroplast.

    Science.gov (United States)

    Shen, Huifeng; Qian, Bingjun; Chen, Weiwei; Liu, Zhenhua; Yang, Litao; Zhang, Dabing; Liang, Wanqi

    2010-08-01

    To test the possibility of producing the novel vaccine in plants against diarrhea normally found in neonatal and newly weaned piglets, the faeG gene, encoding a major F4ac fimbrial subunit protein, was introduced into the tobacco chloroplast genome. After two rounds of selection under spectinomycin, we obtained the transgenic plants nearly homoplasmic. RNA gel blot analysis indicated that faeG and the antibiotic selective gene aminoglycoside 3' adenylyltransferase (aadA) were highly transcribed as a dicistron, while the translational level of recombinant FaeG in transplastomic tobacco was about 0.15% of total soluble protein. The immunogenicity of recombinant FaeG produced in tobacco chloroplasts was confirmed by the observation that FaeG-specific antibodies were elicited in mice immunized with total soluble protein of transgenic plants, as well as the result that mouse sera stimulated by chloroplast-derived recombinant FaeG could neutralize F4ac enterotoxigenic Escherichia coli (ETEC) in vivo. This study provides a new alternative for producing the ETEC vaccine using the chloroplast expression system.

  14. Production of Solar-Grade Silicon by the SiF4 and Mg Reaction

    Science.gov (United States)

    Xie, Xiaobing; Bao, Jianer; Sanjurjo, Angel

    2016-12-01

    Over 90 pct of the solar cells currently produced and installed are Si based, and this industrial dominance is expected to persist for the foreseeable future. The crystalline Si substrate accounts for a significant portion of the total cost of solar cells. In order to further reduce the cost of solar panels, there has been significant effort in producing inexpensive solar-grade Si, mainly through three paths: (1) modification of the Siemens process to lower production costs, (2) upgrading metallurgical-grade Si to reach solar-grade purity, and (3) by means of new metallurgical processes such as the reduction of a silicon halide, e.g., SiF4 or SiCl4, by a reactive metal such as Na or Zn. In this paper, we describe an alternative path that uses Mg to react with SiF4 to produce low-cost solar grade Si. Experimental conditions for complete reaction and separation of the products, Si and MgF2, as well as aspects of the reaction mechanism are described. The reaction involves both a heterogeneous liquid-gas phase reaction and a homogeneous gas-gas phase reaction. When pure Mg was used, the Si product obtained had sub-ppm levels of B and P impurities and is expected to be suitable for solar cell applications.

  15. Production of Solar-Grade Silicon by the SiF4 and Mg Reaction

    Science.gov (United States)

    Xie, Xiaobing; Bao, Jianer; Sanjurjo, Angel

    2016-08-01

    Over 90 pct of the solar cells currently produced and installed are Si based, and this industrial dominance is expected to persist for the foreseeable future. The crystalline Si substrate accounts for a significant portion of the total cost of solar cells. In order to further reduce the cost of solar panels, there has been significant effort in producing inexpensive solar-grade Si, mainly through three paths: (1) modification of the Siemens process to lower production costs, (2) upgrading metallurgical-grade Si to reach solar-grade purity, and (3) by means of new metallurgical processes such as the reduction of a silicon halide, e.g., SiF4 or SiCl4, by a reactive metal such as Na or Zn. In this paper, we describe an alternative path that uses Mg to react with SiF4 to produce low-cost solar grade Si. Experimental conditions for complete reaction and separation of the products, Si and MgF2, as well as aspects of the reaction mechanism are described. The reaction involves both a heterogeneous liquid-gas phase reaction and a homogeneous gas-gas phase reaction. When pure Mg was used, the Si product obtained had sub-ppm levels of B and P impurities and is expected to be suitable for solar cell applications.

  16. Black hole solutions to the $F_4$-model and their orbits (I)

    CERN Document Server

    Chemissany, W; Ruggeri, D; Trigiante, M

    2012-01-01

    In this paper we continue the program of the classification of nilpotent orbits using the approach developed in arXiv:1107.5986, within the study of black hole solutions in D=4 supergravities. Our goal in this work is to classify static, single center black hole solutions to a specific N=2 four dimensional "magic" model, with special K\\"ahler scalar manifold ${\\rm Sp}(6,\\mathbb{R})/{\\rm U}(3)$, as orbits of geodesics on the pseudo-quaternionic manifold ${\\rm F}_{4(4)}/[{\\rm SL}(2,\\mathbb{R})\\times {\\rm Sp}(6,\\mathbb{R})]$ with respect to the action of the isometry group ${\\rm F}_{4(4)}$. Our analysis amounts to the classification of the orbits of the geodesic "velocity" vector with respect to the isotropy group $H^*={\\rm SL}(2,\\mathbb{R})\\times {\\rm Sp}(6,\\mathbb{R})$, which include a thorough classification of the \\emph{nilpotent orbits} associated with extremal solutions and reveals a richer structure than the one predicted by the $\\beta-\\gamma$ labels alone, based on the Kostant Sekiguchi approach. We prov...

  17. Multiferroic fluoride BaCoF4 Thin Films Grown Via Molecular Beam Epitaxy

    Science.gov (United States)

    Borisov, Pavel; Johnson, Trent; García-Castro, Camilo; Kc, Amit; Schrecongost, Dustin; Cen, Cheng; Romero, Aldo; Lederman, David

    Multiferroic materials exhibit exciting physics related to the simultaneous presence of multiple long-range orders, in many cases consisting of antiferromagnetic (AF) and ferroelectric (FE) orderings. In order to provide a new, promising route for fluoride-based multiferroic material engineering, we grew multiferroic fluoride BaCoF4 in thin film form on Al2O3 (0001) substrates by molecular beam epitaxy. The films grow with the orthorhombic b-axis out-of-plane and with three in-plane structural twin domains along the polar c-axis directions. The FE ordering in thin films was verified by FE remanent hysteresis loops measurements at T = 14 K and by room temperature piezoresponse force microscopy (PFM). An AF behavior was found below Neel temperature TN ~ 80 K, which is in agreement with the bulk properties. At lower temperatures two additional magnetic phase transitions at 19 K and 41 K were found. First-principles calculations demonstrated that the growth strain applied to the bulk BaCoF4 indeed favors two canted spin orders, along the b- and a-axes, respectively, in addition to the main AF spin order along the c-axis. Supported by FAME (Contract 2013-MA-2382), WV Research Challenge Grant (HEPC.dsr.12.29), and DMREF-NSF 1434897.

  18. COMPUTING INTRINSIC LY{alpha} FLUXES OF F5 V TO M5 V STARS

    Energy Technology Data Exchange (ETDEWEB)

    Linsky, Jeffrey L. [JILA, University of Colorado and NIST, 440UCB Boulder, CO 80309-0440 (United States); France, Kevin; Ayres, Tom, E-mail: jlinsky@jilau1.colorado.edu [CASA, University of Colorado, 593UCB Boulder, CO 80309-0593 (United States)

    2013-04-01

    The Ly{alpha} emission line dominates the far-ultraviolet spectra of late-type stars and is a major source for photodissociation of important molecules including H{sub 2}O, CH{sub 4}, and CO{sub 2} in exoplanet atmospheres. The incident flux in this line illuminating an exoplanet's atmosphere cannot be measured directly as neutral hydrogen in the interstellar medium (ISM) attenuates most of the flux reaching the Earth. Reconstruction of the intrinsic Ly{alpha} line has been accomplished for a limited number of nearby stars, but is not feasible for distant or faint host stars. We identify correlations connecting the intrinsic Ly{alpha} flux with the flux in other emission lines formed in the stellar chromosphere, and find that these correlations depend only gradually on the flux in the other lines. These correlations, which are based on Hubble Space Telescope spectra, reconstructed Ly{alpha} line fluxes, and irradiance spectra of the quiet and active Sun, are required for photochemical models of exoplanet atmospheres when intrinsic Ly{alpha} fluxes are not available. We find a tight correlation of the intrinsic Ly{alpha} flux with stellar X-ray flux for F5 V to K5 V stars, but much larger dispersion for M stars. We also show that knowledge of the stellar effective temperature and rotation rate can provide reasonably accurate estimates of the Ly{alpha} flux for G and K stars, and less accurate estimates for cooler stars.

  19. Mirror neurons in monkey area F5 do not adapt to the observation of repeated actions.

    Science.gov (United States)

    Caggiano, Vittorio; Pomper, Joern K; Fleischer, Falk; Fogassi, Leonardo; Giese, Martin; Thier, Peter

    2013-01-01

    Repetitive presentation of the same visual stimulus entails a response decrease in the action potential discharge of neurons in various areas of the monkey visual cortex. It is still unclear whether this repetition suppression effect is also present in single neurons in cortical premotor areas responding to visual stimuli, as suggested by the human functional magnetic resonance imaging literature. Here we report the responses of 'mirror neurons' in monkey area F5 to the repeated presentation of action movies. We find that most single neurons and the population at large do not show a significant decrease of the firing rate. On the other hand, simultaneously recorded local field potentials exhibit repetition suppression. As local field potentials are believed to be better linked to the blood-oxygen-level-dependent (BOLD) signal exploited by functional magnetic resonance imaging, these findings suggest caution when trying to derive conclusions on the spiking activity of neurons in a given area based on the observation of BOLD repetition suppression.

  20. Imaging an 80 AU Radius Dust Ring Around the F5V Star HD 157587

    CERN Document Server

    Millar-Blanchaer, Maxwell A; Kalas, Paul; Graham, James R; Duchene, Gaspard; Nielsen, Eric L; Perrin, Marshall; Moon, Dae-Sik; Padgett, Deborah; Metchev, Stanimir; Ammons, S Mark; Bailey, Vanessa P; Barman, Travis; Bruzzone, Sebastian; Bulger, Joanna; Chen, Christine H; Chilcote, Jeffrey; Cotten, Tara; De Rosa, Robert J; Doyon, Rene; Draper, Zachary H; Esposito, Thomas M; Fitzgerald, Michael P; Follette, Katherine B; Gerard, Benjamin L; Greenbaum, Alexandra Z; Hibon, Pascale; Hinkley, Sasha; Hung, Li-Wei; Ingraham, Patrick; Johnson-Groh, Mara; Konopacky, Quinn; Larkin, James E; Macintosh, Bruce; Maire, Jerome; Marchis, Franck; Marley, Mark S; Marois, Christian; Matthews, Brenda C; Oppenheimer, Rebecca; Palmer, David; Patience, Jennifer; Poyneer, Lisa; Pueyo, Laurent; Rajan, Abhijith; Rameau, Julien; Rantakyro, Fredrik T; Savransky, Dmitry; Schneider, Adam C; Sivaramakrishnan, Anand; Song, Inseok; Soummer, Remi; Thomas, Sandrine; Vega, David; Wallace, J Kent; Ward-Duong, Kimberly; Wiktorowicz, Sloane; Wolff, Schuyler

    2016-01-01

    We present $H$-band near-infrared polarimetric imaging observations of the F5V star HD~157587 obtained with the Gemini Planet Imager (GPI) that reveal the debris disk as a bright ring structure at a separation of $\\sim$80$-$100~AU. The new GPI data complement recent HST/STIS observations that show the disk extending out to over 500~AU. The GPI image displays a strong asymmetry along the projected minor axis as well as a fainter asymmetry along the projected major axis. We associate the minor and major axis asymmetries with polarized forward scattering and a possible stellocentric offset, respectively. To constrain the disk geometry we fit two separate disk models to the polarized image, each using a different scattering phase function. Both models favor a disk inclination of $\\sim 70\\degr$ and a $1.5\\pm0.6$ AU stellar offset in the plane of the sky along the projected major axis of the disk. We find that the stellar offset in the disk plane, perpendicular to the projected major axis is degenerate with the for...

  1. The intrinsic extreme ultraviolet fluxes of F5 V to M5 V stars

    Energy Technology Data Exchange (ETDEWEB)

    Linsky, Jeffrey L. [JILA, University of Colorado and NIST, 440UCB Boulder, CO 80309-0440 (United States); Fontenla, Juan [NorthWest Research Associates Inc., 3380 Mitchell Ln, Boulder, CO 80301 (United States); France, Kevin, E-mail: jlinsky@jilau1.colorado.edu, E-mail: jfontenla@nwra.com, E-mail: Kevin.France@colorado.edu [CASA, University of Colorado, 593UCB Boulder, CO 80309-0593 (United States)

    2014-01-01

    Extreme ultraviolet (EUV) radiations (10-117 nm) from host stars play important roles in the ionization, heating, and mass loss from exoplanet atmospheres. Together with the host star's Lyα and far-UV (117-170 nm) radiation, EUV radiation photodissociates important molecules, thereby changing the chemistry in exoplanet atmospheres. Since stellar EUV fluxes cannot now be measured and interstellar neutral hydrogen completely obscures stellar radiation between 40 and 91.2 nm, even for the nearest stars, we must estimate the unobservable EUV flux by indirect methods. New non-LTE semiempirical models of the solar chromosphere and corona and solar irradiance measurements show that the ratio of EUV flux in a variety of wavelength bands to the Lyα flux varies slowly with the Lyα flux and thus with the magnetic heating rate. This suggests and we confirm that solar EUV/Lyα flux ratios based on the models and observations are similar to the available 10-40 nm flux ratios observed with the Extreme Ultraviolet Explorer (EUVE) satellite and the 91.2-117 nm flux observed with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite for F5 V-M5 V stars. We provide formulae for predicting EUV flux ratios based on the EUVE and FUSE stellar data and on the solar models, which are essential input for modeling the atmospheres of exoplanets.

  2. Shielding anisotropy of H-bonded protons in Cs 2GeF 6·4HF

    Science.gov (United States)

    Moroz, N. K.; Panich, A. M.; Gabuda, S. P.

    The chemical shift anisotropy of H-bonded protons in polycrystalline Cs 2GeF 6·4HF was determined by the analysis of NMR continuous wave spectra narrowed by the HF molecular diffusion in the crystal lattice. High resolution of spectral components was achieved due to "selective averaging" of the intermolecular dipole interaction. The derived value of ΔσH = 39 ± 7 ppm is close to that for bifluoride ion in KHF 2. For 19F ΔσF = 86 ± 4 ppm was determined.

  3. Pressure-induced changes in Cr3+-doped elpasolites and LiCaAlF6: Interpretation of macroscopic data

    DEFF Research Database (Denmark)

    Trueba, A. ,; García Lastra, Juan Maria; Aramburu, J. A.

    2010-01-01

    lattices as a function of pressure in the 0–5 GPa range. From the calculated values of the lattice parameter and the Cr3+-X− (X=F, Cl, and Br) distance, R, it is found that R varies with the cell volume, vc, as vc(1/3β) where β lies around 2.6. These results allow one to understand quantitatively the 10Dq...... dependence on V−m/3 for LiCaAlF6:Cr3+ where the measured exponent m=2.3 is seemingly anomalous when compared to the values found for ruby (m=4.5) or NiO (m=5)....

  4. [(18)F]6-fluoro-3,4-dihydroxy-L-phenylalanine--recent modern syntheses for an elusive radiotracer.

    Science.gov (United States)

    Edwards, Richard; Wirth, Thomas

    2015-05-15

    [(18)F]6-fluoro-3,4-dihydroxy-L-phenylalanine ([(18)F]F-DOPA) has been known to be a useful radiotracer for over 30 years. Its widespread clinical use has been hampered by the lack of a robust, high yielding synthesis. This review summarises new developments in radiochemistry that are providing solutions to long standing problems involved in the synthesis of this important but elusive radiotracer. Considerable advances in nucleophilic synthesis have been achieved by optimising multistep strategies and using both hypervalent iodine chemistry and transition metal-mediated fluorinations allowing for the production of high specific activity [(18)F]F-DOPA.

  5. Computational study of the reaction of C6F6 with [IrMe(PEt3)3]: identification of a phosphine-assisted C-F activation pathway via a metallophosphorane intermediate.

    Science.gov (United States)

    Erhardt, Stefan; Macgregor, Stuart A

    2008-11-19

    Density functional theory calculations have been used to model the reaction of C6F6 with [IrMe(PEt3)3], which proceeds with both C-F and P-C bond activation to yield trans-[Ir(C6F5)(PEt3)2(PEt2F)], C2H4, and CH4 (Blum, O.; Frolow, F.; Milstein, D. J. Chem. Soc., Chem. Commun. 1991, 258). Using a model species, trans-[IrMe(PH3)2(PH2Et)], a low-energy mechanism involving nucleophilic attack of the electron-rich Ir metal center at C6F6 with displacement of fluoride has been identified. A novel feature of this process is the capture of fluoride by a phosphine ligand to generate a metallophosphorane intermediate [Ir(C6F5)(Me)(PH3)2(PH2EtF)]. These events occur in a single step via a 4-centered transition state, in a process that we have termed "phosphine-assisted C-F activation". Alternative mechanisms based on C-F activation via concerted oxidative addition or electron-transfer processes proved less favorable. From the metallophosphorane intermediate the formation of the final products can be accounted for by facile ethyl group transfer from phosphorus to iridium followed by beta-H elimination of ethene and reductive elimination of methane. The interpretation of phosphine-assisted C-F activation in terms of nucleophilic attack is supported by the reduced activation barriers computed with the more electron-rich model reactant trans-[IrMe(PMe3)2(PMe2Et)] and the higher barriers found with lesser fluorinated arenes. Reactivity patterns for a range of fluoroarenes indicate the dominance of the presence of ortho-F substituents in promoting phosphine-assisted C-F activation, and an analysis of the charge distribution and transition state geometries indicates that this process is controlled by the strength of the Ir-aryl bond that is being formed.

  6. Pou3f4-mediated regulation of ephrin-b2 controls temporal bone development in the mouse.

    Directory of Open Access Journals (Sweden)

    Steven Raft

    Full Text Available The temporal bone encases conductive and sensorineural elements of the ear. Mutations of POU3F4 are associated with unique temporal bone abnormalities and X-linked mixed deafness (DFNX2/DFN3. However, the target genes and developmental processes controlled by POU3F4 transcription factor activity have remained largely uncharacterized. Ephrin-B2 (Efnb2 is a signaling molecule with well-documented effects on cell adhesion, proliferation, and migration. Our analyses of targeted mouse mutants revealed that Efnb2 loss-of-function phenocopies temporal bone abnormalities of Pou3f4 hemizygous null neonates: qualitatively identical malformations of the stapes, styloid process, internal auditory canal, and cochlear capsule were present in both mutants. Using failed/insufficient separation of the stapes and styloid process as a quantitative trait, we found that single gene Efnb2 loss-of-function and compound Pou3f4/Efnb2 loss-of-function caused a more severe phenotype than single gene Pou3f4 loss-of-function. Pou3f4 and Efnb2 gene expression domains overlapped at the site of impending stapes-styloid process separation and at subcapsular mesenchyme surrounding the cochlea; at both these sites, Efnb2 expression was attenuated in Pou3f4 hemizygous null mutants relative to control. Results of immunoprecipitation experiments using chromatin isolated from nascent middle ear mesenchyme supported the hypothesis of a physical association between Pou3f4 and specific non-coding sequence of Efnb2. We propose that Efnb2 is a target of Pou3f4 transcription factor activity and an effector of mesenchymal patterning during temporal bone development.

  7. Cloning,Expression, Purification and Immunogenicity of House Dust Mite Allergen Der f5%粉尘螨Der f5克隆表达、纯化和免疫原性鉴定

    Institute of Scientific and Technical Information of China (English)

    袁小惠; 高安健; 邬玉兰; 刘志刚

    2013-01-01

    Objective To clone and express the antigen Der f5 from the dust mite dermatopha-goides farinae ,and to identify its immunogenicity. Methods A pair of primers were designed according to the known sequences of Der f 5 gene .Total RN A was extracted from dust mites and Der f5 gene fragments were amplified by RT-PCR .The PCR product was cloned into pMD18-T vector and transferred into E .coli Top10 .The clones were screened and identified by PCR and restriction enzyme digestion .The target gene obtained from the recombinant plasmid by digestion with Bam H Ⅰ and Hind Ⅲ was connected to the prokaryotic expression vector pET-32a.The expressed recombinant plasmid containing Der f5 gene was constructed by cloning target gene into pET-32a and transferred into E .coli Top10 .The recombinant plasmid was transfected into E .coli strain BL21 (DE3 ) and the transfected cells were grown in the presence of inducer IPTG .The expressed recombinant protein was analyzed by SDS-PAGE and Western blotting and was purified by immo-bilized metal ion affinity chromatography. Results The two recombinant plasmids ,pMD18-T-Der f5 and pET32a-Der f5,were constructed successfully .SDS-PAGE showed a correct molecular weight of the recombinant Der f 5 protein .After purification by affinity chromatography ,the protein showed only one strip on SDS-PAGE gel and appropriate ability to bind to IgE in sera of allergic patients .Conclusion The Der f5 gene has been cloned,expressed and purified and the recombinant Der f5 protein shows appropriate IgE-combined ability . The study provides a basis for specific diagnosis and treatment of dust mite-induced allergic disease.%目的 克隆表达粉尘螨第5组变应原(dermatophagoides farinae,Der f5)基因,并鉴定纯化蛋白免疫原性.方法 根据Der f5 基因已知序列,设计出相应的引物,提取粉尘螨总RNA,采用RT-PCR 方法扩增出Der f5 基因片段,PCR 产物克隆入pMD18-T 载体,转化大肠埃希菌 Top10,经PCR和酶切鉴定

  8. Advanced calculations developed for the ITER project within of engineering support framework contracts to F4E; Calculos avanzados desarrollados para el proyecto ITER dentro de los contratos marco de soporte de ingenieria para F4E

    Energy Technology Data Exchange (ETDEWEB)

    Bosch, C.; Polo, J.; Garcia Cid, J.; Guirao, J.; Fernandez, E.; Bayon, A.; Caixas, J.

    2013-07-01

    Present the different kind of analyses carried out within the engineering support framework contracts for F4E in the period 2009-2013 and its evolution according to project needs and Vacuum Vessel manufacturing status.

  9. Pressure-induced changes in Cr3+ -doped elpasolites and LiCaAlF6 : Interpretation of macroscopic data

    Science.gov (United States)

    Trueba, A.; García-Lastra, J. M.; Aramburu, J. A.; García-Fernández, P.; Barriuso, M. T.; Moreno, M.

    2010-06-01

    In the research of pressure effects on Cr3+ -doped insulating lattices, it is crucial to understand the dependence of the 10Dq parameter on the sample volume, V . This problem is explored in the present work through ab initio calculations on Cr3+ -doped K2NaScF6 , Cs2NaYCl6 , and Cs2NaYBr6 elpasolite lattices as a function of pressure in the 0-5 GPa range. From the calculated values of the lattice parameter and the Cr3+-X- ( X=F , Cl, and Br) distance, R , it is found that R varies with the cell volume, vc , as vc(1/3β) where β lies around 2.6. These results allow one to understand quantitatively the 10Dq dependence on V-m/3 for LiCaAlF6:Cr3+ where the measured exponent m=2.3 is seemingly anomalous when compared to the values found for ruby (m=4.5) or NiO (m=5) .

  10. LiCaFeF6: A zero-strain cathode material for use in Li-ion batteries

    Science.gov (United States)

    de Biasi, Lea; Lieser, Georg; Dräger, Christoph; Indris, Sylvio; Rana, Jatinkumar; Schumacher, Gerhard; Mönig, Reiner; Ehrenberg, Helmut; Binder, Joachim R.; Geßwein, Holger

    2017-09-01

    A new zero-strain LiCaFeF6 cathode material for reversible insertion and extraction of lithium ions is presented. LiCaFeF6 is synthesized by a solid-state reaction and processed to a conductive electrode composite via high-energy ball-milling. In the first cycle, a discharge capacity of 112 mAh g-1 is achieved in the voltage range from 2.0 V to 4.5 V. The electrochemically active redox couple is Fe3+/Fe2+ as confirmed by Mössbauer spectroscopy and X-ray absorption spectroscopy. The compound has a trigonal colquiriite-type crystal structure (space group P 3 bar 1 c). By means of in situ and ex situ XRD as well as X-ray absorption fine structure spectroscopy a reversible response to Li uptake/release is found. For an uptake of 0.8 mol Li per formula unit only minimal changes occur in the lattice parameters causing a total change in unit cell volume of less than 0.5%. The spatial distribution of cations in the crystal structure as well as the linkage between their corresponding fluorine octahedra is responsible for this very small structural response. With its zero-strain behaviour this material is expected to exhibit only negligible mechanical degradation. It may be used as a cathode material in future lithium-ion batteries with strongly improved safety and cycle life.

  11. 平面停止域族{FTzz R2+} 满足条件F1-- F4%Families of Stopping--fields {FTZZ} R2+ on Plane .1inSatisfy F1--F4 Conditions

    Institute of Scientific and Technical Information of China (English)

    周新全

    2000-01-01

    This paper first presents families ofstopping --fields on plane and proves that families of stopping--fields FTZZ R2+ satisfy F1--F4 conditions.%本文首次提出平面停止域族FTZ Z R2+,证明了停止域族F2T2 R+2满足F1--F4条件.

  12. Imaging an 80 au Radius Dust Ring around the F5V Star HD 157587

    Science.gov (United States)

    Millar-Blanchaer, Maxwell A.; Wang, Jason J.; Kalas, Paul; Graham, James R.; Duchêne, Gaspard; Nielsen, Eric L.; Perrin, Marshall; Moon, Dae-Sik; Padgett, Deborah; Metchev, Stanimir; Ammons, S. Mark; Bailey, Vanessa P.; Barman, Travis; Bruzzone, Sebastian; Bulger, Joanna; Chen, Christine H.; Chilcote, Jeffrey; Cotten, Tara; De Rosa, Robert J.; Doyon, Rene; Draper, Zachary H.; Esposito, Thomas M.; Fitzgerald, Michael P.; Follette, Katherine B.; Gerard, Benjamin L.; Greenbaum, Alexandra Z.; Hibon, Pascale; Hinkley, Sasha; Hung, Li-Wei; Ingraham, Patrick; Johnson-Groh, Mara; Konopacky, Quinn; Larkin, James E.; Macintosh, Bruce; Maire, Jérôme; Marchis, Franck; Marley, Mark S.; Marois, Christian; Matthews, Brenda C.; Oppenheimer, Rebecca; Palmer, David; Patience, Jennifer; Poyneer, Lisa; Pueyo, Laurent; Rajan, Abhijith; Rameau, Julien; Rantakyrö, Fredrik T.; Savransky, Dmitry; Schneider, Adam C.; Sivaramakrishnan, Anand; Song, Inseok; Soummer, Remi; Thomas, Sandrine; Vega, David; Wallace, J. Kent; Ward-Duong, Kimberly; Wiktorowicz, Sloane; Wolff, Schuyler

    2016-11-01

    We present H-band near-infrared polarimetric imaging observations of the F5V star HD 157587 obtained with the Gemini Planet Imager (GPI) that reveal the debris disk as a bright ring structure at a separation of ∼80–100 au. The new GPI data complement recent Hubble Space Telescope/STIS observations that show the disk extending out to over 500 au. The GPI image displays a strong asymmetry along the projected minor axis as well as a fainter asymmetry along the projected major axis. We associate the minor and major axis asymmetries with polarized forward scattering and a possible stellocentric offset, respectively. To constrain the disk geometry, we fit two separate disk models to the polarized image, each using a different scattering phase function. Both models favor a disk inclination of ∼70° and a 1.5 ± 0.6 au stellar offset in the plane of the sky along the projected major axis of the disk. We find that the stellar offset in the disk plane, perpendicular to the projected major axis is degenerate with the form of the scattering phase function and remains poorly constrained. The disk is not recovered in total intensity due in part to strong adaptive optics residuals, but we recover three point sources. Considering the system’s proximity to the galactic plane and the point sources’ positions relative to the disk, we consider it likely that they are background objects and unrelated to the disk’s offset from the star.

  13. On the Ising character of the quantum-phase transition in LiHoF4

    Directory of Open Access Journals (Sweden)

    R. Skomski

    2016-05-01

    Full Text Available It is investigated how a transverse magnetic field affects the quantum-mechanical character of LiHoF4, a system generally considered as a textbook example for an Ising-like quantum-phase transition. In small magnetic fields, the low-temperature behavior of the ions is Ising-like, involving the nearly degenerate low-lying Jz = ±  8 doublet. However, as the transverse field increases, there is a substantial admixture of states having |Jz| < 8. Near the quantum-phase-transition field, the system is distinctively non-Ising like, and all Jz eigenstates yield ground-state contributions of comparable magnitude. A classical analog to this mechanism is the micromagnetic single point in magnets with uniaxial anisotropy. Since Ho3+ has J = 8, the ion’s behavior is reminiscent of the classical limit (J = ∞, but quantum corrections remain clearly visible.

  14. Thermodynamic assessment of the LiF-NaF-ThF 4-UF 4 system

    Science.gov (United States)

    Beneš, O.; Beilmann, M.; Konings, R. J. M.

    2010-10-01

    A thermodynamic assessment of the LiF-NaF-ThF 4-UF 4 system is presented in this study. The binary phase diagrams are optimized based on the known experimental data and the excess Gibbs energies of liquid and solid solutions are described using a modified quasi chemical model and polynomial formalism respectively. The higher order systems are extrapolated according to asymmetric Toop mathematical formalism. Based on the developed thermodynamic database the fuel composition of the molten salt fast reactor is optimized. In total three different fuel compositions are identified. Properties of these fuel compositions such as melting point, vapour pressure and the boiling temperature are derived from the obtained thermodynamic assessment and are presented in this study.

  15. Rare earth doped glass-ceramics containing NaLaF4 nanocrystals

    Science.gov (United States)

    Elsts, E.; Krieke, G.; Rogulis, U.; Smits, K.; Zolotarjovs, A.; Jansons, J.; Sarakovskis, A.; Kundzins, K.

    2016-09-01

    Oxyfluoride glasses 16Na2O-9NaF-5LaF3-7Al2O3-63SiO2 (mol%) activated with 3% terbium, dysprosium, praseodymium and neodymium fluorides have been prepared and studied by differential thermal analysis, cathodoluminescence, X-ray induced luminescence, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. We found out that the presence of crystalline phase enhances the X-ray induced luminescence intensity. X-ray induced luminescence is the most intense for the sample activated with terbium and treated at 700 °C, whereas the praseodymium and neodymium activated samples have the fastest decay times.

  16. Characterisation of five candidate genes within the ETEC F4ab/ac candidate region in pigs

    OpenAIRE

    Bertschinger Hans U; Neuenschwander Stefan; Vogeli Peter; Archibald Alan L; Bendixen Christian; Edfors Inger; Kracht Steffen S; Esteso Gloria; Joller David; Cirera Susanna; Jacobsen Mette; Rampoldi Antonio; Andersson Leif; Fredholm Merete; Jørgensen Claus B

    2011-01-01

    Abstract Background Enterotoxigenic Escherichia coli (ETEC) that express the F4ab and F4ac fimbriae is a major contributor to diarrhoea outbreaks in the pig breeding industry, infecting both newborn and weaned piglets. Some pigs are resistant to this infection, and susceptibility is inherited as a simple dominant Mendelian trait. Indentifying the genetics behind this trait will greatly benefit pig welfare as well as the pig breeding industry by providing an opportunity to select against genet...

  17. 论(MnF6)4-团簇光谱参量Dq的R-n律%On the R-n law of the spectral parameter Dq in (MnF6)4- cluster

    Institute of Scientific and Technical Information of China (English)

    赵键中; 邝小渝; 周康巍

    2001-01-01

    用配位球壳势模型研究了络合分子中过渡金属离子光谱参量Dq与金属-配体间键长R的R-n律关系。结果表明指数n的变化趋势依赖于配位球壳半径R的增大或减小,在点电荷模型下n值将小于5且随R的减小而减小。在(MnF6)4-团簇键长的实验范围内(R=0.207 nm←→0.214 nm),理论计算值n=4.488与实验观测值n=4.45符合得很好。%he R-n law of the spectral parameter Dq vs the metal-ligand bond length R has been studied by use of the ligand-field model. The investigation shows that the variation of the exponent n depends on the value of R. The physical mechanism reflected by the variable n has been attributed to the fact that the ligand field potential has essentially different forms inside and outside the ligand spherical shell, of which the radius is R. In point charge model, the exponent n will be less than 5 and it will be reduced when the radius R decreases. For the bond length in (MnF6)4- cluster (R=0.207 nm~0.214 nm), the theoretical value n=4.488 is in good agreement with the experimental finding n=4.45.

  18. Computed Verification of Drag Prediction for DLR-F6 Wing Body on Unstructured Grids Flow Solver%基于非结构平台的DLR-F6标模阻力预测

    Institute of Scientific and Technical Information of China (English)

    章锦威; 戚姝妮; 郭承鹏; 董军

    2015-01-01

    This paper used the unstructured grids flow solver UNSMB to have a computed verification of the drag force for the DLR –F6 wing body configuration .Selective analysis on grid convergence , lift-drag curves and pressure distribute of the wing body configuration , and compare the computing results with the results of different solversand the wind tunnel data .The analysis results showsthat the computing results ofthe unstructured grids flow solver are close to the results of different solvers and the wind tunnel data ,to a certain extent it has a verification and validation forthe accuracy of computed drag of the solver .%采用自研的非结构网格解算器UNSMB进行了AIAA第三届阻力会议提供的DLR-F6翼身组合体的阻力计算验证。重点分析了模型的网格收敛特性、升阻力曲线以及压力分布等,并把计算结果与阻力预测会议上各个软件的计算结果以及试验数据进行比较,在此基础上分析计算结果。分析结果显示,非结构混合网格解算器的计算结果与各个软件的计算结果以及风洞试验数据吻合度较好,一定程度上验证与确认了解算器的阻力预测精度。

  19. Dysfunctional memory CD8+ T cells after priming in the absence of the cell cycle regulator E2F4.

    Science.gov (United States)

    Bancos, Simona; Cao, Qingyu; Bowers, William J; Crispe, Ian Nicholas

    2009-01-01

    The transcriptional repressor E2F4 is important for cell cycle exit and terminal differentiation in epithelial cells, neuronal cells and adipocytes but its role in T lymphocytes proliferation and memory formation is not known. Herein, we investigated the function of E2F4 protein for the formation of functional murine memory T cells. Murine transgenic CD8+ T cells were infected in vitro with lentivirus vector expressing a shRNA targeted against E2F4 followed by in vitro stimulation with SIINFEKL antigenic peptide. For in vivo assays, transduced cells were injected into congenic mice which were then infected with HSV-OVA. The primary response, memory formation and secondary stimulation were determined for CD8+ lentivirus transduced cells. In the absence of E2F4 cell cycle repressor, activated CD8+ T cells underwent intensive proliferation in vitro and in vivo. These cells had the ability to differentiate into memory cells in vivo, but they were defective in recall proliferation. We show that transient suppression of E2F4 during CD8+ T cell priming enhances primary proliferation and has a negative effect on secondary stimulation. These findings demonstrate that the cell cycle repressor E2F4 is essential for the formation of functional memory T cells. A decrease in CD8+ T-lymphocyte compartment would diminish our capacity to control viral infections.

  20. Low Temperature Deposition of PECVD Polycrystalline Silicon Thin Films using SiF4 / SiH4 mixture

    Science.gov (United States)

    Syed, Moniruzzaman; Inokuma, Takao; Kurata, Yoshihiro; Hasegawa, Seiichi

    2016-03-01

    Polycrystalline silicon films with a strong (110) texture were prepared at 400°C by a plasma-enhanced chemical vapor deposition using different SiF4 flow rates ([SiF4] = 0-0.5 sccm) under a fixed SiH4 flow rate ([SiH4] = 1 or 0.15 sccm). The effects of the addition of SiF4 to SiH4 on the structural properties of the films were studied by Raman scattering, X-ray diffraction (XRD), Atomic force microscopy and stress measurements. For [SiH4] = 1 sccm, the crystallinity and the (110) XRD grain size monotonically increased with increasing [SiF4] and their respective maxima reach 90% and 900 Å. However, for [SiH4] = 0.15 sccm, both the crystallinity and the grain size decreased with [SiF4]. Mechanisms causing the change in crystallinity are discussed, and it was suggested that an improvement in the crystallinity, due to the addition of SiF4, is likely to be caused by the effect of a change in the surface morphology of the substrates along with the effect of in situ chemical cleaning.

  1. Enhanced hydrogen storage properties of MgH2 co-catalyzed with K2NiF6 and CNTs.

    Science.gov (United States)

    Sulaiman, N N; Ismail, M

    2016-12-06

    The composite of MgH2/K2NiF6/carbon nanotubes (CNTs) is prepared by ball milling, and its hydrogenation properties are studied for the first time. MgH2 co-catalyzed with K2NiF6 and CNTs exhibited an improvement in the onset dehydrogenation temperature and isothermal de/rehydrogenation kinetics compared with the MgH2-K2NiF6 composite. The onset dehydrogenation temperature of MgH2 doped with 10 wt% K2NiF6 and 5 wt% CNTs is 245 °C, which demonstrated a reduction of 25 °C compared with the MgH2 + 10 wt% K2NiF6 composite. In terms of rehydrogenation kinetics, MgH2 doped with 10 wt% K2NiF6 and 5 wt% CNTs samples absorbed 3.4 wt% of hydrogen in 1 min at 320 °C, whereas the MgH2 + 10 wt% K2NiF6 sample absorbed 2.6 wt% of hydrogen under the same conditions. For dehydrogenation kinetics at 320 °C, the MgH2 + 10 wt% K2NiF6 + 5 wt% CNTs sample released 3.3 wt% hydrogen after 5 min of dehydrogenation. By contrast, MgH2 doped with 10 wt% K2NiF6 released 3.0 wt% hydrogen in the same time period. The apparent activation energy, Ea, for the dehydrogenation of MgH2 doped with 10 wt% K2NiF6 reduced from 100.0 kJ mol(-1) to 70.0 kJ mol(-1) after MgH2 was co-doped with 10 wt% K2NiF6 and 5 wt% CNTs. Based on the experimental results, the hydrogen storage properties of the MgH2/K2NiF6/CNTs composite is enhanced because of the catalytic effects of the active species of KF, KH and Mg2Ni that are formed in situ during dehydrogenation, as well as the unique structure of CNTs.

  2. Unusual Mixed Valence of Eu in Two Materials-EuSr2Bi2S4F4 and Eu2SrBi2S4F4: Mössbauer and X-ray Photoemission Spectroscopy Investigations.

    Science.gov (United States)

    Haque, Zeba; Thakur, Gohil Singh; Parthasarathy, Rangasamy; Gerke, Birgit; Block, Theresa; Heletta, Lukas; Pöttgen, Rainer; Joshi, Amish G; Selvan, Ganesan Kalai; Arumugam, Sonachalam; Gupta, Laxmi Chand; Ganguli, Ashok Kumar

    2017-02-28

    We have synthesized two new Eu-based compounds, EuSr2Bi2S4F4 and Eu2SrBi2S4F4, which are derivatives of Eu3Bi2S4F4, an intrinsic superconductor with Tc = 1.5 K. They belong to a tetragonal structure (SG: I4/mmm, Z = 2), similar to the parent compound Eu3Bi2S4F4. Our structural and (151)Eu Mössbauer spectroscopy studies show that, in EuSr2Bi2S4F4, Eu-atoms exclusively occupy the crystallographic 2a-sites. In Eu2SrBi2S4F4, 2a-sites are fully occupied by Eu-atoms and the other half of Eu-atoms and Sr-atoms together fully occupy 4e-sites in a statistical distribution. In both compounds Eu atoms occupying the crystallographic 2a-sites are in a homogeneous mixed valent state ∼2.6-2.7. From our magnetization studies in an applied H ≤ 9 T, we infer that the valence of Eu-atoms in Eu2SrBi2S4F4 at the 2a-sites exhibits a shift toward 2+. Our XPS studies corroborate the occurrence of valence fluctuations of Eu and after Ar-ion sputtering show evidence of enhanced population of Eu(2+)-states. Resistivity measurements, down to 2 K, suggest a semimetallic nature for both compounds.

  3. A new crystal structure for (BEDT–TTF)2SbF6 and some of its physical properties

    Indian Academy of Sciences (India)

    G K R Senadeera; T Mori

    2005-02-01

    A new crystal structure for bis(ethylenedithio)tetrathiafulvalene [(BEDT–TTF)2 SbF6] was determined by single crystal X-ray diffraction. The crystal structure was refined in the $P \\overline{1}$ space group at room temperature. Crystal data for new structure are as follows: triclinic, = 8.670 (2) Å, = 8.664 (2) Å, = 16.842 (5) Å, = 89$^\\circ \\cdot$29 (2), = 90$^\\circ \\cdot$71 (3), = 92$^\\circ \\cdot$67 (1), = 1263.64 Å3, = 2, = 2.136 g cm-3, (Mo–K), = 0.7107 Å, = 0.057 for a total of 5517 independent reflections. The donors form a trimerized column, and the band structure calculated by the tight-binding approximation shows band insulator properties. The temperature dependent of the d.c. resistivity shows a semiconducting behaviour with room temperature resistivity along the -axis; $\\rho_{290 K}$ = 5.6 ohm cm.

  4. Two-photon excitation spectroscopy of Cr3+:K2NaScF6 elpasolite: II. Theoretical models

    Science.gov (United States)

    Bartram, R. H.; Wein, G. R.; Hamilton, D. S.

    2001-03-01

    Two-photon excitation (TPE) spectra of Cr3+:K2NaScF6, excited by a Raman-shifted, Nd:YAG-pumped tunable dye laser, exhibit several unexpected features. A weak TPE spectrum of the symmetry-forbidden 4A2g→ 4T2g transition is observed without a zero-phonon line. The symmetry-allowed TPE spectrum of the 4A2g→ 4T1ag transition has a multi-phonon side band with anomalously extended vibrational progressions, and an anomalously weak, split zero-phonon line with anomalous polarization anisotropy. These observations are explained, respectively, in terms of theoretical models involving phonon assistance, departures from the closure approximation that permit electron-lattice coupling in intermediate states and a low-temperature phase transition involving librational instability. Hypothetical line-shape simulations are compared with observed TPE spectra.

  5. Modeling Temporal Processes in Early Spacecraft Design: Application of Discrete-Event Simulations for Darpa's F6 Program

    Science.gov (United States)

    Dubos, Gregory F.; Cornford, Steven

    2012-01-01

    While the ability to model the state of a space system over time is essential during spacecraft operations, the use of time-based simulations remains rare in preliminary design. The absence of the time dimension in most traditional early design tools can however become a hurdle when designing complex systems whose development and operations can be disrupted by various events, such as delays or failures. As the value delivered by a space system is highly affected by such events, exploring the trade space for designs that yield the maximum value calls for the explicit modeling of time.This paper discusses the use of discrete-event models to simulate spacecraft development schedule as well as operational scenarios and on-orbit resources in the presence of uncertainty. It illustrates how such simulations can be utilized to support trade studies, through the example of a tool developed for DARPA's F6 program to assist the design of "fractionated spacecraft".

  6. Mapping QTL affecting resistance to Marek's disease in an F6 advanced intercross population of commercial layer chickens

    Directory of Open Access Journals (Sweden)

    Wang Jing

    2009-01-01

    Full Text Available Abstract Background Marek's disease (MD is a T-cell lymphoma of chickens caused by the Marek's disease virus (MDV, an oncogenic avian herpesvirus. MD is a major cause of economic loss to the poultry industry and the most serious and persistent infectious disease concern. A full-sib intercross population, consisting of five independent families was generated by crossing and repeated intercrossing of two partially inbred commercial White Leghorn layer lines known to differ in genetic resistance to MD. At the F6 generation, a total of 1615 chicks were produced (98 to 248 per family and phenotyped for MD resistance measured as survival time in days after challenge with a very virulent plus (vv+ strain of MDV. Results QTL affecting MD resistance were identified by selective DNA pooling using a panel of 15 SNPs and 217 microsatellite markers. Since MHC blood type (BT is known to affect MD resistance, a total of 18 independent pool pairs were constructed according to family × BT combination, with some combinations represented twice for technical reasons. Twenty-one QTL regions (QTLR affecting post-challenge survival time were identified, distributed among 11 chromosomes (GGA1, 2, 3, 4, 5, 8, 9, 15, 18, 26 and Z, with about two-thirds of the MD resistance alleles derived from the more MD resistant parental line. Eight of the QTLR associated with MD resistance, were previously identified in a backcross (BC mapping study with the same parental lines. Of these, 7 originated from the more resistant line, and one from the less resistant line. Conclusion There was considerable evidence suggesting that MD resistance alleles tend to be recessive. The width of the QTLR for these QTL appeared to be reduced about two-fold in the F6 as compared to that found in the previous BC study. These results provide a firm basis for high-resolution linkage disequilibrium mapping and positional cloning of the resistance genes.

  7. VizieR Online Data Catalog: C/2012 F6 (Lemmon) and C/2012 S1 (ISON) maps (Cordiner+, 2014)

    Science.gov (United States)

    Cordiner, M. A.; Remijan, A. J.; Boissier, J.; Milam, S. N.; Mumma, M. J.; Charnley, S. B.; Paganini, L.; Villanueva, G.; Bockelee-Morvan, D.; Kuan, Y.-J.; Chuang, Y.-L.; Lis, D. C.; Biver, N.; Crovisier, J.; Minniti, D.; Coulson, I. M.

    2017-04-01

    WCS-calibrated fits image files of the molecular flux maps shown in Figure 1 for HCN, HNC and H2CO observed in comets C/2012 F6 (Lemmon) and C/2012 S1 (ISON) using ALMA. The files are labeled with the corresponding comet and molecule names. The files are standard two-dimensional fits images, which can be opened in fits image viewers such as SAOimage DS9, CASA viewer, or Starlink Gaia. GIMP and Adobe Photoshop can also be used, provided the appropriate plugins are present. The images contain flux values (in units of Jansky km/s per beam), as a function of celestial coordinate in the J2000 equatorial system. Due to the cometary motions, the absolute coordinate systems are accurate only at the start of the observations (dates and times are given in Table 1). These images are the result of integrating the (3D) ALMA data cubes over the full widths of the observed spectral lines (equivalent to collapsing the data cubes along their respective spectral/velocity axes). The beam dimensions (BMAJ and BMIN), corresponding to the angular resolution of the images, are given in the image headers in units of degrees. object.dat : -------------------------------------------------------------------------------- Code Name Elem q e i H1 d AU deg mag -------------------------------------------------------------------------------- C/2012 F6 Lemmon 2456375.5 0.7312461 0.9985125 82.607966 7.96 C/2012 S1 Ison 2456624.5 0.0124515 0.9998921 64.401571 6.11 (2 data files).

  8. Spectroscopy of Pr3+ 4f5d Configuration in LaF3 Nanocrystals/Oxyfluoride Glass Ceramics

    Institute of Scientific and Technical Information of China (English)

    Meng Chunxia; Huang Shihua; You Fangtian; Tao Ye; Xu Jianhua; Zhang Guobin; Wang Xiaojun; Dejneka M J; Yen W M

    2005-01-01

    There are two types of Pr3+ ion in the Pr3+ doped oxyfluoride glass containing LaF3 nanocrystal: the lowest 4f5d state of Pr3+ in LaF3 nanocrystal is located energetically higher than the 1S0 state, while in glass the lowest 4f5d state is lower than the 1S0 state. We deduce the positions of the lowest 4f5d band of these two types of Pr3+ ion by vacuum ultraviolet (VUV) and ultraviolet (UV) excitation spectra. When the sample is excited by 181 nm, the narrow band emission of 4f2→4f2 of Pr3+ ion in the nanocrystal and the broad band emission of 4f5d→4f2 in the glass appear at the same time. However, the second step of the photon cascade emission(PCE) of Pr3+ in the LaF3 nanocrystal, corresponding to the emission of 3P0→3H4, can be observed at 20 K, but not at room temperature. The reason accounting for this phenomenon was discussed in detail.

  9. Dual therapeutic functions of F-5 fragment in burn wounds: preventing wound progression and promoting wound healing in pigs.

    Science.gov (United States)

    Bhatia, Ayesha; O'Brien, Kathryn; Chen, Mei; Wong, Alex; Garner, Warren; Woodley, David T; Li, Wei

    2016-01-01

    Burn injuries are a leading cause of morbidity including prolonged hospitalization, disfigurement, and disability. Currently there is no Food and Drug Administration-approved burn therapeutics. A clinical distinction of burn injuries from other acute wounds is the event of the so-called secondary burn wound progression within the first week of the injury, in which a burn expands horizontally and vertically from its initial boundary to a larger area. Therefore, an effective therapeutics for burns should show dual abilities to prevent the burn wound progression and thereafter promote burn wound healing. Herein we report that topically applied F-5 fragment of heat shock protein-90α is a dual functional agent to promote burn wound healing in pigs. First, F-5 prevents burn wound progression by protecting the surrounding cells from undergoing heat-induced caspase 3 activation and apoptosis with increased Akt activation. Accordingly, F-5-treated burn and excision wounds show a marked decline in inflammation. Thereafter, F-5 accelerates burn wound healing by stimulating the keratinocyte migration-led reepithelialization, leading to wound closure. This study addresses a topical agent that is capable of preventing burn wound progression and accelerating burn wound healing.

  10. Fatigue life extension of epoxy materials using ultrafast epoxy-SbF5 healing system introduced by manual infiltration

    Directory of Open Access Journals (Sweden)

    X. J. Ye

    2015-03-01

    Full Text Available The present paper is devoted to the verification of the capability of epoxy-SbF5 system as a healing chemistry for rapidly retarding and/or arresting fatigue cracks in epoxy materials at room temperature. Owing to the very fast curing speed of epoxy catalyzed by SbF5, epoxy monomer and the hardener (ethanol solution of SbF5–ethanol complex are successively infiltrated into the fracture plane under cyclic loading during the tension-tension fatigue test. As a result, the mechanisms including hydrodynamic pressure crack tip shielding, polymeric wedge and adhesive bonding of the healing agent are revealed. It is found that the healing agent forms solidified wedge at the crack tip within 20 s after start of polymerization of the epoxy monomer, so that the highest healing effect is offered at the moment. The epoxy-SbF5 system proves to be effective in rapidly obstructing fatigue crack propagation (despite that its cured version has lower fracture toughness than the matrix, and satisfies the requirement of constructing fast self-healing polymeric materials.

  11. BaGdF5:Dy(3+),Tb(3+),Eu(3+) multifunctional nanospheres: paramagnetic, luminescence, energy transfer, and tunable color.

    Science.gov (United States)

    Guan, Hongxia; Song, Yanhua; Zheng, Keyan; Sheng, Ye; Zou, Haifeng

    2016-05-18

    A series of Dy(3+),Tb(3+) and Eu(3+) singly, doubly or triply doped BaGdF5 phosphors were synthesized by a one-step hydrothermal method with l-arginine, and their energy transfer, migrations and multicolored luminescence properties were investigated in detail. The as-prepared Dy(3+),Tb(3+) or Eu(3+) doped samples showed strong blue, green and red emission, respectively. Different hues of green and red light were obtained by co-doped Dy(3+),Tb(3+) and Tb(3+),Eu(3+) in the BaGdF5 host, respectively. More significantly, in the Dy(3+),Tb(3+),Eu(3+) tri-doped BaGdF5 phosphors, colors changed from yellow green to orange red by adjusting the doping concentration of Eu(3+). Energy migrations from Dy(3+) to Tb(3+) and from Tb(3+) to Eu(3+) are reported in detail. Furthermore, the obtained samples exhibit paramagnetic properties at room temperature and low temperature. It is obvious that these Dy(3+), Tb(3+), Eu(3+) singly or doubly or triply doped BaGdF5 nanomaterials with tunable multicolored luminescence properties may have potential applications in the fields of full-color displays, biological labels and bio-separation.

  12. Jakobssonite, CaAlF5, a new mineral from fumaroles at the Eldfell and Hekla volcanoes, Iceland

    DEFF Research Database (Denmark)

    Balic Zunic, Tonci; Garavelli, A.; Mitolo, D.;

    2012-01-01

    The new mineral jakobssonite, ideally CaAlF5, was first found in crusts collected in 1988 from a fumarole on the Eldfell volcano, Heimaey Island, Iceland. It was subsequently found in similar crusts collected in 1991 from a fumarole on the Hekla volcano, Iceland. It is associated with leonardsenite...

  13. Direct conversion of inulin into cell lipid by an inulinase-producing yeast Rhodosporidium toruloides 2F5.

    Science.gov (United States)

    Wang, Zhi-Peng; Fu, Wen-Juan; Xu, Hong-Mei; Chi, Zhen-Ming

    2014-06-01

    In this study, an inulinase-producing yeast strain 2F5 of Rhodosporidium toruloides was obtained. It was found that the yeast strain 2F5 could produce higher amount of oil from inulin and larger lipid bodies in its cells than any other yeast strains tested in this study. Under the optimal conditions, 62.14% (w/w) of lipid based on cell dry weight and 15.82g/l of the dry cell mass were produced from 6.0% (w/v) inulin at flask level, leaving 0.92% (w/v) of total sugar in the fermented medium. During 2-l fermentation, 70.36% (w/w) of lipid based on cell dry weight and 15.64g/l of the dry cell mass were produced from 6.0% (w/v) inulin. Over 99.09% of the fatty acids from the yeast strain 2F5 grown on inulin was C16:0, C18:0, C18:1 and C18:2, especially C18:1 (52.2%). The biodiesel prepared using the lipids produced by the yeast strain 2F5 could be burnt well.

  14. Spectroscopic properties of UV active medium Ce3+:LiSr0.8Ca0.2AlF6

    Science.gov (United States)

    Nizamutdinov, A. S.; Shavelev, A. A.; Marisov, M. A.; Semashko, V. V.

    2016-02-01

    The aim of this work is phase composition and near UV spectroscopic studies of UV active media in fluoride crystals with colquiriite structure, such as Ce3+:LiSr0.8Ca0.2AlF6. Colquiriite structure mixed crystals show higher segregation coefficient of Ce3+ activator ions than common LiCaAlF6 hosts. An important result is based on the fact that this enhancement was achieved for two types of Ce3+ centers in a multisite Ce:LiSr0.8Ca0.2AlF6 system. Thus, it provides a higher gain coefficient for the 5d-4f transitions of Ce3+ ions and it spans a wider continuous wavelength tuning range between 280 and 320 nm for tunable Ce:LiSr0.8Ca0.2AlF6 laser systems.

  15. Magnetic properties of lithium rare-earth fluorides: Ferromagnetism in LiErF4 and LiHoF4 and crystal-field parameters at the rare-earth and Li sites

    DEFF Research Database (Denmark)

    Hansen, P. E.; Johansson, Torben; Nevald, Rolf

    1975-01-01

    was observed, but extrapolation indicates that below 0.5 K it will be ferromagnetic with the magnetic moments in the crytalline ab plane. From the susceptibilities the crystal-field parameters Bnm with (n, m)=(2, 0), (4, 0), (4, 4), (6, 0), (6, 4) have been extracted giving for Er3+ in LiErF4: 430., -985......-order crystal-field parameters at the Li site: q=0.0363, 0.0354, and 0.0343 Å-3 for the Er, Ho, and Tb compound, respectively. The crystal-field parameters are compared to values calculated from point charges, showing agreement at the Li sites but not at the rare earth sites.......Single crystals of LiErF4 and LiHoF4 have been grown and their magnetic properties measured from 1.3 K to 300 K. LiHoF4 turned out to be a nearly ideal Ising ferromagnet with TC=1.30±0.05 K and a saturation magnetization along the crystalline c axis of (6.98±0.02)μB. In LiErF4 no ordering...

  16. DLR-F6复杂组合体跨声速阻力计算研究%Study of transonic drag computation on the DLR-F6 complex configurations

    Institute of Scientific and Technical Information of China (English)

    张宏; 颜洪

    2013-01-01

    The accuracy of the drag prediction was investigated by simulating the transonic flow fields around the DLR-F6 wing-body (WB) and wing-body-nacelle-pylon (WBNP) configurations. The computations were performed using fully turbulence boundary-layer and fixed position transition boundary-layer respectively. Multiple sets of grids with different densities were then employed. The drag, drag increments by adding the nacelle and the pylon and the effects of grid and transition were also estimated. The results show that grid refinement leads to convergent results for two configurations, and the predicted surface pressure distributions on the wing and nacelle are in agreement with the experimental data. When comparing the experiment data, the predicted incremental drag was over estimated by about 3 drag counts, 0.000 3, but better than the results obtained by using other software. The computed results show that grid refinement had little effect on the wall surface pressure distributions, but obvious effect on drag, especially the pressure drag. Relative to the whole turbulence model, transition had obvious effect on drag, particularly on friction drag, but almost no effect on nacelle/pylon induced incremental drag.%为了考察阻力预测的准确性,评估挂架/吊舱引起的阻力增量,分析网格和转捩对阻力及阻力增量的影响,采用不同密度网格,对DLR-F6翼/身和翼/身/挂/舱组合体跨声速流场进行了全湍流和固定转捩2种方式的数值模拟.翼/身和翼/身/挂/舱组合体均得到了网格收敛性结果,机翼表面和吊舱表面压力分布与实验数据吻合良好.预测的阻力增量高出实验数据0.0003,优于其他软件的结果.网格细分对壁面压力分布影响较小,对阻力尤其是压差阻力影响较大;相对于全湍流,转捩对阻力尤其是摩擦阻力影响较大,对挂架/吊舱引起的阻力增量几乎没有影响.

  17. Atomic Linkage Flexibility Tuned Isotropic Negative, Zero, and Positive Thermal Expansion in MZrF6 (M = Ca, Mn, Fe, Co, Ni, and Zn).

    Science.gov (United States)

    Hu, Lei; Chen, Jun; Xu, Jiale; Wang, Na; Han, Fei; Ren, Yang; Pan, Zhao; Rong, Yangchun; Huang, Rongjin; Deng, Jinxia; Li, Laifeng; Xing, Xianran

    2016-11-09

    The controllable isotropic thermal expansion with a broad coefficient of thermal expansion (CTE) window is intriguing but remains challenge. Herein we report a cubic MZrF6 series (M = Ca, Mn, Fe, Co, Ni and Zn), which exhibit controllable thermal expansion over a wide temperature range and with a broader CTE window (-6.69 to +18.23 × 10(-6)/K). In particular, an isotropic zero thermal expansion (ZTE) is achieved in ZnZrF6, which is one of the rarely documented high-temperature isotropic ZTE compounds. By utilizing temperature-dependent high-energy synchrotron X-ray total scattering diffraction, it is found that the flexibility of metal···F atomic linkages in MZrF6 plays a critical role in distinct thermal expansions. The flexible metal···F atomic linkages induce negative thermal expansion (NTE) for CaZrF6, whereas the stiff ones bring positive thermal expansion (PTE) for NiZrF6. Thermal expansion could be transformed from striking negative, to zero, and finally to considerable positive though tuning the flexibility of metal···F atomic linkages by substitution with a series of cations on M sites of MZrF6. The present study not only extends the scope of NTE families and rare high-temperature isotropic ZTE compounds but also proposes a new method to design systematically controllable isotropic thermal expansion frameworks from the perspective of atomic linkage flexibility.

  18. Beyond CTLA-4 and PD-1: Orphan nuclear receptor NR2F6 as T cell signaling switch and emerging target in cancer immunotherapy.

    Science.gov (United States)

    Klepsch, Victoria; Hermann-Kleiter, Natascha; Baier, Gottfried

    2016-10-01

    Blockade of immune checkpoints has emerged as key strategy in the development of effective cancer therapies. In contrast to cell surface checkpoints like CTLA-4 and PD-1, however, additional cancer therapeutic targets are located inside the effector immune cells. Targeting these alternative checkpoints in cancer immunotherapy with the goal to strengthen the patient's immune system are likely to extend the benefits of cancer immunotherapy in the near future. Along this line, we have defined and validated the orphan nuclear receptor NR2F6 (nuclear receptor subfamily 2 group F member 6, also called Ear-2) as an intracellular immune checkpoint in effector T cells. NR2F6 acts as a novel master switch of antitumor responses against both transplantable and spontaneous tumors in mice relevant for human cancer. NR2F6 directly represses transcription of key cytokine genes in T effector cells relevant for tumor cell rejection, such as IL-2, IFN and TNFα. Thus, in the presence of NR2F6, T cell activation is limited within the tumor microenvironment. This defines NR2F6 as a key checkpoint governing the amplitude of cancer immune surveillance. Based on our study, an approach shall be initiated to identify low molecular weight compounds that selectively interfere with NR2F6 function in the clinic.

  19. Exact partition functions for deformed $\\mathcal{N}=2$ theories with $N_{f}=4$ flavours

    CERN Document Server

    Beccaria, Matteo; Macorini, Guido; Martina, Luigi

    2016-01-01

    We consider the $\\Omega$-deformed $\\mathcal{N}=2$ $SU(2)$ gauge theory in four dimensions with $N_{f}=4$ massive fundamental hypermultiplets. The low energy effective action depends on the deformation parameters $\\varepsilon_{1}, \\varepsilon_{2}$, the scalar field expectation value $a$, and the hypermultiplet masses ${\\bf m}=(m_{1}, m_{2}, m_{3}, m_{4})$. Motivated by recent findings in the $\\mathcal{N}=2^{*}$ theory, we explore the theories that are characterized by special fixed ratios $\\varepsilon_{2}/\\varepsilon_{1}$ and ${\\bf m}/\\varepsilon_{1}$ and propose a simple condition on the structure of the multi-instanton contributions to the prepotential determining the effective action. This condition determines a finite set $\\Pi_{N}$ of special points such that the prepotential has $N$ poles at fixed positions independent on the instanton number. In analogy with what happens in the $\\mathcal{N}=2^{*}$ gauge theory, the full prepotential of the $\\Pi_{N}$ theories may be given in closed form as an explicit fun...

  20. Size and shape effects in β-NaGdF4: Yb3+, Er3+ nanocrystals

    Science.gov (United States)

    Noculak, Agnieszka; Podhorodecki, Artur

    2017-04-01

    Three sets of β-NaGdF4:Yb3+, Er3+ nanocrystals (NCs) with different shapes (spherical and more complex flower shapes), different sizes (6-17 nm) and Yb3+ concentrations (2%-15%) were synthesized by a co-precipitation method using oleic acid as a stabilizing agent. The uncommon, single-crystalline flower-shaped NCs were obtained by simply adjusting the fluorine-to-lanthanides molar ratio. Additionally, some of the NCs with different sizes have been covered by the un-doped shell. The crystal phase, shapes and sizes of all NCs were examined using transmission electron microscopy and x-ray diffraction methods. Simultaneously, upconversion luminescence and lifetimes, under 980 nm excitation, were measured and the changes in green to red (G/R) emission ratios as well as emission decay times were correlated with the evolution of nanocrystal sizes and surface to volume ratios. Three different mechanisms responsible for the changes in G/R ratios were presented and discussed.

  1. Pressure-enhanced superconductivity in Eu3Bi2S4F4

    Science.gov (United States)

    Luo, Yongkang; Zhai, Hui-Fei; Zhang, Pan; Xu, Zhu-An; Cao, Guang-Han; Thompson, J. D.

    2014-12-01

    The pressure effect on the newly discovered charge-transferred BiS2-based superconductor, Eu3Bi2S4F4 , with a Tc of 1.5 K at ambient pressure, is investigated by transport and magnetic measurements. Accompanied with the enhancement of metallicity under pressures, the onset superconducting transition temperature increases abruptly around 1.0 GPa, reaching ˜10.0 K at 2.26 GPa. Alternating current magnetic susceptibility measurements indicate that a new superconducting phase with a higher Tc emerges and dominates at high pressures. In the broad pressure window of 0.68 GPa≤p ≤2.00 GPa, the high-Tc phase coexists with the low-Tc phase. Hall effect measurements reveal a significant difference in electronic structures between the two superconducting phases. Our work devotes the effort to establish the commonality of pressure effect on the BiS2-based superconductors, and also uncovers the importance of electron carrier density in the high-Tc phase.

  2. F4E studies for the electromagnetic analysis of ITER components

    Energy Technology Data Exchange (ETDEWEB)

    Testoni, P., E-mail: pietro.testoni@f4e.europa.eu [Fusion for Energy, Torres Diagonal Litoral B3, c/ Josep Plá n.2, Barcelona (Spain); Cau, F.; Portone, A. [Fusion for Energy, Torres Diagonal Litoral B3, c/ Josep Plá n.2, Barcelona (Spain); Albanese, R. [Associazione EURATOM/ENEA/CREATE, DIETI, Università Federico II di Napoli, Napoli (Italy); Juirao, J. [Numerical Analysis TEChnologies S.L. (NATEC), c/ Marqués de San Esteban, 52 Entlo D Gijón (Spain)

    2014-10-15

    Highlights: • Several ITER components have been analyzed from the electromagnetic point of view. • Categorization of DINA load cases is described. • VDEs, MDs and MFD have been studied. • Integral values of forces and moments components versus time have been computed for all the ITER components under study. - Abstract: Fusion for Energy (F4E) is involved in a relevant number of activities in the area of electromagnetic analysis in support of ITER general design and EU in-kind procurement. In particular several ITER components (vacuum vessel, blanket shield modules and first wall panels, test blanket modules, ICRH antenna) are being analyzed from the electromagnetic point of view. In this paper we give an updated description of our main activities, highlighting the main assumptions, objectives, results and conclusions. The plasma instabilities we consider, typically disruptions and VDEs, can be both toroidally symmetric and asymmetric. This implies that, depending on the specific component and loading conditions, FE models we use span from a sector of 10 up to 360° of the ITER machine. The techniques for simulating the electromagnetic phenomena involved in a disruption and the postprocessing of the results to obtain the loads acting on the structures are described. Finally we summarize the typical loads applied to different components and give a critical view of the results.

  3. Genetic variability and homozygosity in a F4 castor bean population by microsatellite markers

    Directory of Open Access Journals (Sweden)

    Edna Lobo Machado

    2016-01-01

    Full Text Available ABSTRACT The objectives of this study were to identify the genetic variability and estimate the level of homozygosity in a castor bean F4 population using microsatellite markers (SSR. To this end, it was performed the genotyping of the population through 53 pairs of SSR primers. Allele frequencies were estimated by number of alleles per locus, expected heterozygosity (He, observed heterozygosity (Ho and polymorphic information content (PIC. An array of genetic dissimilarity was generated by Nei and Li index, and hierarchical cluster analysis was performed using the Unweighted Pair-Group Method Averages (UPGMA method. Polymorphism was detected in a total of eight loci (15.09% of the 53 evaluated, with the presence of two alleles per locus. Allele frequencies varied between 0.71 and 0.53, and the PIC, between 0.32 and 0.37. The average observed heterozygosity Ho (0.30 was lower than the expected heterozygosity He (0.47. Five dissimilar groups were formed, showing that there is genetic variability among the evaluated genotypes. The highest genetic dissimilarity was 0.708 and the lowest, 0.00. The percentages of homozygous genotypes varied from 25 to 75%. These results show that controlled selfing in castor bean raises the level of homozygosity, important for the breeding program.

  4. AKTIVITAS INULINASE OLEH Pichia manshurica DAN FUSAN F4 PADA FERMENTASI BATCH DENGAN UMBI DAHLIA (Dahlia sp SEBAGAI SUBSTRAT

    Directory of Open Access Journals (Sweden)

    Wijanarka Wijanarka

    2013-11-01

    Full Text Available ACTIVITY OF INULINASE OF Pichia Manshuria AND FUSAN F4 ON BATCH FERMENTATION UDING DAHLIA TUBER (Dahlia sp AS A SUBSTRATE. A dahlia tuber is one of the common inulin rich crops. Inulin is formed by units of fructans, which are polymers of D-fructose. Inulinases (EC 3.2.1.7 catalyze the hydrolysis of inulin, producing fructooligosaccharides (FOS, inulooligosaccharides (IOS, pulullan, acetone, butanol and sorbitol, therefore dahlia tubers are used as growth media. The inulin hydrolyzing activity has been reported from various microbial strains Pichia manshurica and Fusan F4 which is the result of fusion protoplast. The objective of this study was to determine the activity of inulinase Pichia manshurica and Fusan F4 on the substrate dahlia tubers. Fusan F4 to increase inulinase activity compared with Pichia manshurica and to investigate the kinetics of specific growth rate (μ and time double (g from of Pichia manshurica and Fusan F4. The results showed that the exponential phase occurs at 0-12 hour without a lag phase. P. manshurica has a specific growth rate (μ of 0.18/hour with time double (g 3.90 hours and the inulinase enzyme activity of 0.56 IU, while for Fusan F4 consecutive has a value μ of 0.20/hour, g of 3.49 hours and the activity of 0.69 IU. The conclusion of this research is to improve Fusan F4 inulinase activity and the ability has to be better than the Pichia manshurica.Umbi dahlia merupakan salah satu umbi yang mengandung inulin. Inulin merupakan polimer fruktan yang dapat dipecah oleh enzim inulinase (E.C. 3.2.1.7 menjadi fruktosa. Fruktosa merupakan bahan baku dasar untuk pembuatan FOS, IOS, pulullan, aseton dan sorbitol, oleh karena itu umbi dahlia digunakan sebagai media pertumbuhan. Enzim inulinase ini secara indigenous dimiliki oleh Pichia manshurica dan Fusan F4 yang merupakan hasil fusi protoplas.Tujuan  penelitian ini adalah  untuk mengetahui aktivitas inulinase Pichia manshurica dan Fusan F4 pada substrat umbi dahlia

  5. Characterization and Expression Analysis of Goat Ovarian chi-miR-100f-5p%山羊卵巢富集chi-miR-100f-5p的鉴定与表达分析

    Institute of Scientific and Technical Information of China (English)

    娜日苏; 郑姣; 张家骅; 刘广; 向阳; 赵海林; 吴亭; 赵金红; 李凡; 黄选洋; 孙晓卫

    2013-01-01

    [目的]探讨山羊卵巢中富集的 miR-100及预测的靶基因与山羊卵巢功能及卵泡发育的潜在关系,为山羊繁殖机理研究提供数据。[方法]以山羊卵巢组织为材料,通过miRNA的分离、克隆及测序得到山羊卵巢中表达的miR-100,采用RT-qPCR进行表达检测,用生物信息学方法预测miR-100的靶基因及其功能。[结果]①山羊卵巢的测序结果中,一段成熟体为21nt 的序列与果蝇dan-miR-100高度同源,将其命名为chi-miR-100f-5p,其前体位于基因组负(-)链上,长度为59 bp,定位于山羊 CM000899.1:33997894-33997914序列;②chi-miR-100f-5p 在山羊卵巢、垂体及心脏等组织中均有表达,说明此miRNA不是卵巢组织所特有;心脏和垂体组织中均有较高表达,其次是卵巢,而在肝脏、脾脏、肺及肾脏中表达显著低于卵巢(P<0.01);在单产羔内蒙古绒山羊卵巢中chi-miR-100f-5p的表达极显著高于高繁殖力大足黑山羊卵巢(P<0.01);③ chi-miR-100f-5p主要靶作用于整合蛋白β1亚基基因及垂体特异性转录因子1基因,可能参与整合蛋白信号通路,促进垂体内分泌细胞的生长与分化,调节下丘脑-垂体-性腺轴激素分泌。[结论]山羊卵巢中新发现的 chi-miR-100f-5p 可能是与繁殖调控有关的重要候选miRNAs 之一。%[Objective] The relationship between the goat ovarian expressed miR-100 with its predicted target genes and goat ovarian function or follicular development was studied in order to provide data for goat breeding mechanism.[Method] Goat ovarian expressed miR-100 was obtained by cloning and sequencing a small RNA library with pooled RNA from goat ovarian tissue. The expression profiling was detected by RT-qPCR. miR-100 target genes and functional classification were predicted by bioinformatics method.[Result]The chi-miR-100f-5p, at a length of 21 nt , was isolated from goat ovaries. The sequence is highly

  6. Thermodynamic assessment of the LiF-ThF4-PuF3-UF4 system

    Science.gov (United States)

    Capelli, E.; Beneš, O.; Konings, R. J. M.

    2015-07-01

    The LiF-ThF4-PuF3-UF4 system is the reference salt mixture considered for the Molten Salt Fast Reactor (MSFR) concept started with PuF3. In order to obtain the complete thermodynamic description of this quaternary system, two binary systems (ThF4-PuF3 and UF4-PuF3) and two ternary systems (LiF-ThF4-PuF3 and LiF-UF4-PuF3) have been assessed for the first time. The similarities between CeF3/PuF3 and ThF4/UF4 compounds have been taken into account for the presented optimization as well as in the experimental measurements performed, which have confirmed the temperatures predicted by the model. Moreover, the experimental results and the thermodynamic database developed have been used to identify potential compositions for the MSFR fuel and to evaluate the influence of partial substitution of ThF4 by UF4 in the salt.

  7. SELEKSI GALUR DARI POPULASI F4 KEDELAI YANG TAHAN TERHADAP PENYAKIT MOSAIK (Soybean mosaic virus DAN BERDAYA HASIL TINGGI

    Directory of Open Access Journals (Sweden)

    Wuye Ria Andayanie

    2015-06-01

    Full Text Available Soybean lines selection of F4 population resistant  to soybean mosaic disease (Soybean mosaic virus with high yield.  The soybean breeding program is usually not purposedly done for resistance to Soybean mosaic virus (SMV but rather for crop yields. The experiment was aimed to obtain soybean lines of F4 population resistant to soybean mosaic disease with high yield.  F2-F4 plants that have been inoculated with the T isolate of SMV one week after planting were selected by the pedigree  in the screen house. The result indicated eight  F4 populations (Wilis x L. Temanggung; Wilis x L. Jombang; Wilis x Pangrango; Wilis x PI 200485;  Gepak Kuning x L. Jombang; Gepak Kuning x L. Temanggung; Gepak Kuning x Malabar; Gepak Kuning x PI 200485 produced medium seed size (from 9.84-10.26 g 100/seeds.  Gepak Kuning x Mlg 3288  showed more resistant than Gepak Kuning x PI 200485. The seed produced by Gepak Kuning x PI 200485 was 1.97 ton/ha. There were no F4 populations that had higher yield and bigger seed size than Gepak Kuning x PI 200485 even though they were  moderately resistant to SMV. Therefore, these lines of Gepak Kuning x Mlg 3288 and Gepak  Kuning x  PI 200485 might provide exellent sources to develop a new variety that resistant to SMV and of high yield.

  8. Characterisation of five candidate genes within the ETEC F4ab/ac candidate region in pigs

    DEFF Research Database (Denmark)

    Jacobsen, Mette Juul; Cirera Salicio, Susanna; Joller, David

    2011-01-01

    /ac resistant and ETEC F4ab/ac susceptible animals in any of the tested tissues. CONCLUSIONS: None of the identified polymorphisms are obvious causative mutations for ETEC F4ab/ac susceptibility, as they have no impact on the level of the overall mRNA expression nor predicted to influence the composition...... of the amino acids composition. However, we cannot exclude that the five tested genes are bona fide candidate genes for susceptibility to ETEC F4ab/ac infection since the identified polymorphism might affect the translational apparatus, alternative splice forms may exist and post translational mechanisms might...... dominant Mendelian trait. Indentifying the genetics behind this trait will greatly benefit pig welfare as well as the pig breeding industry by providing an opportunity to select against genetically susceptible animals, thereby reducing the number of diarrhoea outbreaks. The trait has recently been mapped...

  9. Acoustic measurements of F-4E aircraft operating in hush house, NSN 4920-02-070-2721

    Science.gov (United States)

    Miller, V. R.; Plzak, G. A.; Chinn, J. M.

    1981-09-01

    The primary purpose of this test program was to measure the acoustic environment in the hush house facility located at Kelly Air Force Base, Texas, during operation of the F-4E aircraft to ensure that aircraft structural acoustic design limits were not exceeded. The acoustic measurements showed that sonic fatigue problems are anticipated with the F-4E aircraft aft fuselage structure during operation in the hush house. The measured acoustic levels were less than those measured in an F-4E aircraft water cooled hush house at Hill AFB in the lower frequencies, but were increased over that measured during ground run up on some areas of the aircraft. It was recommended that the acoustic loads measured in this program should be specified in the structural design criteria for aircraft which will be subjected to hush house operation or defining requirements for associated equipment. Recommendations were also made to increase the fatigue life of the aft fuselage.

  10. {sup 111}In-anti-F4/80-A3-1 antibody: a novel tracer to image macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Terry, Samantha Y.A. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); King' s College London, St Thomas' Hospital, Department of Imaging Chemistry and Biology, London (United Kingdom); Boerman, Otto C.; Gerrits, Danny; Franssen, Gerben M.; Oyen, Wim J.G. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Metselaar, Josbert M. [University of Twente, Targeted Therapeutics, MIRA Institute for Biomedical Technology and Technical Medicine, Enschede (Netherlands); Lehmann, Steffi; Gerdes, Christian A. [Roche Innovation Center Zurich, Roche Pharmaceutical Research and Early Development (pRED), Zurich (Switzerland); Abiraj, Keelara [Roche Innovation Center Basel, Roche Pharmaceutical Research and Early Development (pRED), Basel (Switzerland)

    2015-08-15

    Here, the expression of F4/80 on the cell surface of murine macrophages was exploited to develop a novel imaging tracer that could visualize macrophages in vivo. The immunoreactive fraction and IC{sub 50} of anti-F4/80-A3-1, conjugated with diethylenetriaminepentaacetic acid (DTPA) and radiolabelled with {sup 111}In, were determined in vitro using murine bone marrow-derived macrophages. In vivo biodistribution studies were performed with {sup 111}In-anti-F4/80-A3-1 and isotype-matched control antibody {sup 111}In-rat IgG2b at 24 and 72 h post-injection (p.i.) in SCID/Beige mice bearing orthotopic MDA-MB-231 xenografts. In some studies mice were also treated with liposomal clodronate. Macrophage content in tissues was determined immunohistochemically. Micro-single photon emission computed tomography (SPECT)/CT images were also acquired. In vitro binding assays showed that {sup 111}In-anti-F4/80-A3-1 specifically binds F4/80 receptor-positive macrophages. The immunoreactivity of anti-F4/80-A3-1 was 75 % and IC{sub 50} was 0.58 nM. In vivo, injection of 10 or 100 μg {sup 111}In-anti-F4/80-A3-1 resulted in splenic uptake of 78 %ID/g and 31 %ID/g, respectively, and tumour uptake of 1.38 %ID/g and 4.08 %ID/g, respectively (72 h p.i.). Liposomal clodronate treatment reduced splenic uptake of 10 μg {sup 111}In-anti-F4/80-A3-1 from 248 %ID/g to 114 %ID/g and reduced {sup 111}In-anti-F4/80-A3-1 uptake in the liver and femur (24 h p.i.). Tracer retention in the blood and tumour uptake increased (24 h p.i.). Tumour uptake of {sup 111}In-anti-F4/80-A3-1 was visualized by microSPECT/CT. Macrophage density in the spleen and liver decreased in mice treated with liposomal clodronate. Uptake of {sup 111}In-rat IgG2b was lower in the spleen, liver and femur when compared to {sup 111}In-anti-F4/80-A3-1. Radiolabelled anti-F4/80-A3-1 antibodies specifically localize in tissues infiltrated by macrophages in mice and can be used to visualize tumours. The liver and spleen act as antigen

  11. Characterisation of five candidate genes within the ETEC F4ab/ac candidate region in pigs

    DEFF Research Database (Denmark)

    Jacobsen, Mette Juul; Cirera Salicio, Susanna; Joller, David

    2011-01-01

    of possible causative mutations. A total of 34 polymorphisms were identified in either coding regions or their flanking introns. The genotyping data for two of those were found to perfectly match the genotypes at the ETEC F4ab/ac locus, a G to C polymorphism in intron 11 of TFRC and a C to T silent....../ac resistant and ETEC F4ab/ac susceptible animals in any of the tested tissues. CONCLUSIONS: None of the identified polymorphisms are obvious causative mutations for ETEC F4ab/ac susceptibility, as they have no impact on the level of the overall mRNA expression nor predicted to influence the composition...

  12. Thickness and nanomechanical properties of protective layer formed by TiF4 varnish on enamel after erosion

    Directory of Open Access Journals (Sweden)

    Maria Isabel Dantas de MEDEIROS

    2016-01-01

    Full Text Available Abstract The layer formed by fluoride compounds on tooth surface is important to protect the underlying enamel from erosion. However, there is no investigation into the properties of protective layer formed by NaF and TiF4 varnishes on eroded enamel. This study aimed to evaluate the thickness, topography, nanohardness, and elastic modulus of the protective layer formed by NaF and TiF4 varnishes on enamel after erosion using nanoindentation and atomic force microscopy (AFM. Human enamel specimens were sorted into control, NaF, and TiF4 varnish groups (n = 10. The initial nanohardness and elastic modulus values were obtained and varnishes were applied to the enamel and submitted to erosive challenge (10 cycles: 5 s cola drink/5 s artificial saliva. Thereafter, nanohardness and elastic modulus were measured. Both topography and thickness were evaluated by AFM. The data were subjected to ANOVA, Tukey’s test and Student’s t test (α = 0.05. After erosion, TiF4 showed a thicker protective layer compared to the NaF group and nanohardness and elastic modulus values were significantly lower than those of the control group. It was not possible to measure nanohardness and elastic modulus in the NaF group due to the thin protective layer formed. AFM showed globular deposits, which completely covered the eroded surface in the TiF4 group. After erosive challenge, the protective layer formed by TiF4 varnish showed significant properties and it was thicker than the layer formed by NaF varnish.

  13. Exact partition functions for deformed N=2 theories with N{sub f}=4 flavours

    Energy Technology Data Exchange (ETDEWEB)

    Beccaria, Matteo; Fachechi, Alberto; Macorini, Guido; Martina, Luigi [Dipartimento di Matematica e Fisica Ennio De Giorgi, Università del Salento,Via Arnesano, 73100 Lecce (Italy); INFN, Via Arnesano, 73100 Lecce (Italy)

    2016-12-07

    We consider the Ω-deformed N=2SU(2) gauge theory in four dimensions with N{sub f}=4 massive fundamental hypermultiplets. The low energy effective action depends on the deformation parameters ε{sub 1},ε{sub 2}, the scalar field expectation value a, and the hypermultiplet masses m=(m{sub 1},m{sub 2},m{sub 3},m{sub 4}). Motivated by recent findings in the N=2{sup ∗} theory, we explore the theories that are characterized by special fixed ratios ε{sub 2}/ε{sub 1} and m/ε{sub 1} and propose a simple condition on the structure of the multi-instanton contributions to the prepotential determining the effective action. This condition determines a finite set Π{sub N} of special points such that the prepotential has N poles at fixed positions independent on the instanton number. In analogy with what happens in the N=2{sup ∗} gauge theory, the full prepotential of the Π{sub N} theories may be given in closed form as an explicit function of a and the modular parameter q appearing in special combinations of Eisenstein series and Jacobi theta functions with well defined modular properties. The resulting finite pole partition functions are related by AGT correspondence to special 4-point spherical conformal blocks of the Virasoro algebra. We examine in full details special cases where the closed expression of the block is known and confirms our Ansatz. We systematically study the special features of Zamolodchikov’s recursion for the Π{sub N} conformal blocks. As a result, we provide a novel effective recursion relation that can be exactly solved and allows to prove the conjectured closed expressions analytically in the case of the Π{sub 1} and Π{sub 2} conformal blocks.

  14. Exact partition functions for deformed N=2 theories with N_f=4 flavours

    Science.gov (United States)

    Beccaria, Matteo; Fachechi, Alberto; Macorini, Guido; Martina, Luigi

    2016-12-01

    We consider the Ω-deformed N=2 SU(2) gauge theory in four dimensions with N f = 4 massive fundamental hypermultiplets. The low energy effective action depends on the deformation parameters ɛ 1 , ɛ 2, the scalar field expectation value a, and the hypermultiplet masses m = ( m 1 , m 2 , m 3 , m 4). Motivated by recent findings in the N={2}^{*} theory, we explore the theories that are characterized by special fixed ratios ɛ 2 /ɛ 1 and m /ɛ 1 and propose a simple condition on the structure of the multi-instanton contributions to the prepotential determining the effective action. This condition determines a finite set Π N of special points such that the prepotential has N poles at fixed positions independent on the instanton number. In analogy with what happens in the N={2}^{*} gauge theory, the full prepotential of the Π N theories may be given in closed form as an explicit function of a and the modular parameter q appearing in special combinations of Eisenstein series and Jacobi theta functions with well defined modular properties. The resulting finite pole partition functions are related by AGT correspondence to special 4-point spherical conformal blocks of the Virasoro algebra. We examine in full details special cases where the closed expression of the block is known and confirms our Ansatz. We systematically study the special features of Zamolodchikov's recursion for the Π N conformal blocks. As a result, we provide a novel effective recursion relation that can be exactly solved and allows to prove the conjectured closed expressions analytically in the case of the Π1 and Π2 conformal blocks.

  15. Spectroscopic study of the interaction of Nd{sup +3} with amino acids: phenomenological 4f-4f intensity parameters

    Energy Technology Data Exchange (ETDEWEB)

    Jerico, Soraya; Carubelli, Celia R.; Massabni, Ana M.G.; Stucchi, Elizabeth B.; Leite, Sergio R. de A. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica; Malta, Oscar [Pernambuco Univ., Recife, PE (Brazil). Dept. de Quimica Fundamental

    1998-10-01

    We have studied behaviour of the phenomenological 4f-4f intensity parameters in compounds of the Nd{sup 3+} ion with glycine, L-aspartic acid, L-glutamic acid, L-histidine, DL-malic acid and Aspartame{sup TM} in aqueous solution, as function of the pK values and partial charges on the oxygens of the carboxylate groups of these molecules. The results are discussed and qualitatively interpreted in terms of the forced electric dipole and dynamic coupling mechanisms of the 4f-4f intensities, thus indicating that the forced electric dipole mechanism is dominant. (author)

  16. Thickness and nanomechanical properties of protective layer formed by TiF4 varnish on enamel after erosion

    OpenAIRE

    Medeiros, Maria Isabel Dantas de; Carlo, Hugo Lemes; Lacerda-Santos, Rogério; Bruno Alessandro Guedes de LIMA; Souza, Frederico Barbosa de; Rodrigues, Jonas de Almeida [UNESP; Carvalho,Fabiola Galbiatti de

    2016-01-01

    Abstract The layer formed by fluoride compounds on tooth surface is important to protect the underlying enamel from erosion. However, there is no investigation into the properties of protective layer formed by NaF and TiF4 varnishes on eroded enamel. This study aimed to evaluate the thickness, topography, nanohardness, and elastic modulus of the protective layer formed by NaF and TiF4 varnishes on enamel after erosion using nanoindentation and atomic force microscopy (AFM). Human enamel speci...

  17. Structural insight in the inhibition of adherence of F4 fimbriae producing enterotoxigenic Escherichia coli by llama single domain antibodies.

    Science.gov (United States)

    Moonens, Kristof; Van den Broeck, Imke; Okello, Emmanuel; Pardon, Els; De Kerpel, Maia; Remaut, Han; De Greve, Henri

    2015-02-24

    Enterotoxigenic Escherichia coli that cause neonatal and post-weaning diarrhea in piglets express F4 fimbriae to mediate attachment towards host receptors. Recently we described how llama single domain antibodies (VHHs) fused to IgA, produced in Arabidopsis thaliana seeds and fed to piglets resulted in a progressive decline in shedding of F4 positive ETEC bacteria. Here we present the structures of these inhibiting VHHs in complex with the major adhesive subunit FaeG. A conserved surface, distant from the lactose binding pocket, is targeted by these VHHs, highlighting the possibility of targeting epitopes on single-domain adhesins that are non-involved in receptor binding.

  18. Evaluation of fluoride release from experimental TiF4 and NaF varnishes in vitro

    Directory of Open Access Journals (Sweden)

    Livia Picchi COMAR

    2014-04-01

    Full Text Available Fluoride varnishes play an important role in the prevention of dental caries, promoting the inhibition of demineralization and the increase of remineralization. Objective: This study aimed to analyze the amount of fluoride released into water and artificial saliva from experimental TiF4 and NaF varnishes, with different concentrations, for 12 h. Material and Methods: Fluoride varnishes were applied on acrylic blocks and then immersed in 10 ml of deionized water and artificial saliva in polystyrene bottles. The acrylic blocks were divided in seven groups (n=10: 1.55% TiF4 varnish (0.95% F, pH 1.0; 3.10% TiF4 varnish (1.90% F, pH 1.0; 3.10% and 4% TiF4 varnish (2.45% F, pH 1.0; 2.10% NaF varnish (0.95% F, pH 5.0; 4.20% NaF varnish (1.90% F, pH 5.0; 5.42% NaF varnish (2.45% F, pH 5.0 and control (no treatment, n=5. The fluoride release was analyzed after 1/2, 1, 3, 6, 9 and 12 h of exposure. The analysis was performed using an ion-specific electrode coupled to a potentiometer. Two-way ANOVA and Bonferroni's test were applied for the statistical analysis (p<0.05. Results: TiF4 varnishes released larger amounts of fluoride than NaF varnishes during the first 1/2 h, regardless of their concentration; 4% TiF4 varnish released more fluoride than NaF varnishes for the first 6 h. The peak of fluoride release occurred at 3 h. There was a better dose-response relationship among the varnishes exposed to water than to artificial saliva. Conclusions: The 3.10% and 4% TiF4 -based varnishes have greater ability to release fluoride into water and artificial saliva compared to NaF varnish; however, more studies must be conducted to elucidate the mechanism of action of TiF4 varnish on tooth surface.

  19. Decolorization and biodegradation of congo red dye by a novel white rot fungus Alternaria alternata CMERI F6.

    Science.gov (United States)

    Chakraborty, Samayita; Basak, Bikram; Dutta, Subhasish; Bhunia, Biswanath; Dey, Apurba

    2013-11-01

    A novel white rot fungus Alternaria alternata CMERI F6 decolorized 99.99% of 600 mg/L congo red within 48 h in yeast extract-glucose medium at 25 °C, pH 5 and 150 rpm. Physicochemical parameters like carbon and nitrogen sources, temperature, pH and aeration were optimized to develop faster decolorization process. Dye decolorization rate was maximal (20.21 mg/L h) at 25 °C, pH 5, 150 rpm and 800 mg/L dye, giving 78% final decolorization efficiency. Scanning electron microscopy and X-ray Diffraction analysis revealed that the fungus become amorphous after dye adsorption. HPLC and FTIR analysis of the extracted metabolites suggested that the decolorization occurred through biosorption and biodegradation. Thermogravimetric analysis (TGA), differential thermal analysis (DTA) and acid-alkali and 70% ethanol treatment revealed the efficient dye retention capability of the fungus. The foregoing results justify the applicability of the strain in removal of congo red from textile wastewaters and their safe disposal.

  20. Recovery of high surface area mesoporous silica from waste hexafluorosilicic acid (H2SiF6) of fertilizer industry.

    Science.gov (United States)

    Sarawade, Pradip B; Kim, Jong-Kil; Hilonga, Askwar; Kim, Hee Taik

    2010-01-15

    In this article we report recovery of mesoporous silica from the waste material (hexafluorosilicic acid) of phosphate fertilizer industry. The process involves the reaction of hexafluorosilicic acid (50 ml, 24 wt% H(2)SiF(6)) and 100ml, 0.297 M Na(2)CO(3) to generate the alkaline aqueous slurry. Silica was separated from the slurry by filtration and the sodium fluoride was extracted from the aqueous solution by evaporation method. The obtained mesoporous silica was characterized by N(2) absorption/desorption (BET), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM), and EDS. The results confirm that the separation of silica and NaF was successful and the final products have high purity. The silica product was found to have an average pore diameter of 4.14 nm and a high surface area (up to 800 m(2)/g). The process reported in this study may significantly reduce the release of hazardous materials into the environment and it might confer economic benefits to the responsible industries.

  1. Flocculating Properties and Production of the Compound Bioflocculant by Rhizobium Radiobacter F2 and Bacillus Sphaeicus F6

    Institute of Scientific and Technical Information of China (English)

    Lixin Li; Lingyan Feng; Fang Ma; Qianshen Zhao

    2015-01-01

    A compound bioflocculant CBF, produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6, was investigated with regard to its production and flocculating properties. The optimization of the culture medium constituents including carbon source, nitrogen source and C/N ratio, metal ions and ionic strength on CBF production were studied. Flocculating properties of CBF were examined by a series of experiments and CBF had good flocculating activities in kaolin suspension with divalent cations and stable over wide range of pH. Studies of the flocculating properties revealed that the flocculation could be stimulated by cations Ca2+, Mg2+, Fe2+, Al3+and Fe3+. In addition, it was stable at 4-30℃ in the presence of CaCl2 . It was found to be effective for flocculation of a kaolin suspension under neutral and weak alkaline conditions ( pH 7�0-9�0 ) , and flocculating activities of higher than 95% were obtained when the CBF concentrations among 6-14 mg/L at pH 8�0. The results of this study indicate that CBF is a potential replacement of conventional synthetic flocculants and is widely applied in water treatment and downstream processing of food and fermentation industries.

  2. Two-photon excitation spectroscopy of Cr3+:K2NaScF6 elpasolite: I. Experimental aspects

    Science.gov (United States)

    Wein, G. R.; Hamilton, D. S.; Sliwczuk, U.; Rinzler, A. G.; Bartram, R. H.

    2001-03-01

    Two-photon excitation experiments were performed to improve understanding of electron-lattice coupling and its effects on intra-3d3 transitions. Cr3+ occupies a scandium octahedral site in K2NaScF6. The transitions studied were 4A2g→ 4T2g and 4A2g→ 4T1ag. Complete spectra were recorded at a temperature of 10 K with the polarization vector or crystallographic direction. The two bands exhibit different polarization anisotropies and phonon couplings. The electric-dipole-forbidden 4A2g→ 4T2g band appears to be built on an eg-mode false origin and contains Fano antiresonances. This broad transition band lacks a zero-phonon line or any other sharp structure. The 4A2g→ 4T1ag transition zero-phonon line is evident and shows a 163 cm-1 low-temperature phase-transition-induced splitting. It also contains an extended progression of 35 phonon peaks corresponding to a lattice mode with phonon energy 106 cm-1, and a second progression with phonon energy 310 cm-1. The very asymmetric phonon side band displays a polarization anisotropy that differs from that of the zero-phonon line. To facilitate analysis of the data, measurements of low-temperature 4T2g→ 4A2g emission spectra with one-photon excitation are also reported and interpreted in the present paper.

  3. Modulazione della risposta visiva dei neuroni specchio della corteccia premotoria ventrale della scimmia (F5) in relazione al contesto sociale

    OpenAIRE

    Di Domenico, Rossella

    2015-01-01

    Several studies show that mirror neurons' discharge in the monkey ventral premotor cortex and in the inferior parietal lobule is modulated by the action's goal and by the context in which the action has been executed (Fogassi et al., 2005; Bonini et al. 2009). In this study, we investigated how the social context can influence the modulation of visual mirror neurons' discharge in the monkey ventral premotor cortex (F5). In particular, we investigated if contextual information (such as the pre...

  4. Core/Shell NaGdF4:Nd3+/NaGdF4 Nanocrystals with Efficient Near-Infrared to Near-Infrared Downconversion Photoluminescence for Bioimaging Applications

    Science.gov (United States)

    Chen, Guanying; Ohulchanskyy, Tymish Y.; Liu, Sha; Law, Wing-Cheung; Wu, Fang; Swihart, Mark T.; Ågren, Hans; Prasad, Paras N.

    2012-01-01

    We have synthesized core/shell NaGdF4:Nd3+/NaGdF4 nanocrystals with an average size of 15 nm and exceptionally high photoluminescence (PL) quantum yield. When excited at 740 nm, the nanocrystals manifest spectrally distinguished, near infrared to near infrared (NIR-to-NIR) downconversion PL peaked at ~900, ~1050, and ~1300 nm. The absolute quantum yield of NIR-to-NIR PL reached 40% for core-shell nanoparticles dispersed in hexane. Time-resolved PL measurements revealed that this high quantum yield was achieved through suppression of nonradiative recombination originating from surface states and cross relaxations between dopants. NaGdF4:Nd3+/NaGdF4 nanocrystals, synthesized in organic media, were further converted to be water-dispersible by eliminating the capping ligand of oleic acid. NIR-to-NIR PL bioimaging was demonstrated both in vitro and in vivo through visualization of the NIR-to-NIR PL at ~900 nm under incoherent lamp light excitation. The fact that both excitation and the PL of these nanocrystals are in the biological window of optical transparency, combined with their high quantum efficiency, spectral sharpness and photostability, makes these nanocrystals extremely promising as optical biomaging probes. PMID:22401578

  5. SNHG16 contributes to breast cancer cell migration by competitively binding miR-98 with E2F5.

    Science.gov (United States)

    Cai, Chang; Huo, Qiang; Wang, Xiaolong; Chen, Bing; Yang, Qifeng

    2017-02-20

    Long noncoding RNAs (lncRNAs) have been proved to play important roles in cellular processes of cancer, including the development, proliferation, and migration of cancer cells. In the present study, we demonstrated small nucleolar RNA host gene 16 (SNHG16) as an oncogene on cell migration in breast cancer. Expression levels of SNHG16 were found to be frequently higher in breast cancer tissues than in the paired noncancerous tissues. Gain- and loss-of-function studies proved that SNHG16 significantly promoted breast cancer cell migration. We predicted SNHG16 as a competitive endogenous RNA (ceRNA) of E2F transcription factor 5 protein (E2F5) via competition for the shared miR-98 through bioinformatics analysis, and proved this regulation using relative quantitative real-time PCR (qRT-PCR), western blot, RNA immunoprecipitation (RIP) assay and luciferase reporter assay. In addition, we identified a positive correlation between SNHG16 and E2F5 in breast cancer tissues. Furthermore, we demonstrated that forced expression of miR-98 could partially abrogate SNHG16-mediated increase of breast cancer cells migration, suggesting that SNHG16 promoted cell migration in a miR-98 dependent manner. Taken together, our findings indicated that SNHG16 induces breast cancer cell migration by competitively binding miR-98 with E2F5, and SNHG16 can serve as a potential therapeutic target for breast cancer treatment.

  6. Organic Monolayers by B(C6F5)3-Catalyzed Siloxanation of Oxidized Silicon Surfaces

    Science.gov (United States)

    2017-01-01

    Inspired by the homogeneous catalyst tris(pentafluorophenyl) borane [B(C6F5)3], which acts as a promotor of Si–H bond activation, we developed and studied a method of modifying silicon oxide surfaces using hydrosilanes with B(C6F5)3 as the catalyst. This dedihydrosiloxanation reaction yields complete surface coverage within 10 min at room temperature. Organic monolayers derived from hydrosilanes with varying carbon chain lengths (C8–C18) were prepared on oxidized Si(111) surfaces, and the thermal and hydrolytic stabilities of the obtained monolayers were investigated in acidic (pH 3) medium, basic (pH 11) medium, phosphate-buffered saline (PBS), and deionized water (neutral conditions) for up to 30 days. DFT calculations were carried out to gain insight into the mechanism, and the computational results support a mechanism involving silane activation with B(C6F5)3. This catalyzed reaction path proceeds through a low-barrier-height transition state compared to the noncatalyzed reaction path. PMID:28230381

  7. 2012年F5 Networks应用交付高峰论坛北京站盛大召开

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    2012年3月,全球应用交付网络厂商F5 Networks以北京作为首站,召开了主题为"构架IT灵捷之道"的应用交付高峰论坛。F5 Networks技术联盟副总裁Calvin Rowland先生、F5 Networks中国渠道总监周炜先生、

  8. 40 CFR Table F-5 to Subpart F of... - Estimated Mass Concentration Measurement of PM2.5 for Idealized “Typical” Coarse Aerosol Size...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Estimated Mass Concentration Measurement of PM2.5 for Idealized âTypicalâ Coarse Aerosol Size Distribution F Table F-5 to Subpart F of Part... of Class II Equivalent Methods for PM2.5 Pt. 53, Subpt. F, Table F-5 Table F-5 to Subpart F of Part...

  9. EBV Nuclear Antigen 3C Mediates Regulation of E2F6 to Inhibit E2F1 Transcription and Promote Cell Proliferation.

    Science.gov (United States)

    Pei, Yonggang; Banerjee, Shuvomoy; Sun, Zhiguo; Jha, Hem Chandra; Saha, Abhik; Robertson, Erle S

    2016-08-01

    Epstein-Barr virus (EBV) is considered a ubiquitous herpesvirus with the ability to cause latent infection in humans worldwide. EBV-association is evidently linked to different types of human malignancies, mainly of epithelial and lymphoid origin. Of interest is the EBV nuclear antigen 3C (EBNA3C) which is critical for EBV-mediated immortalization. Recently, EBNA3C was shown to bind the E2F1 transcription regulator. The E2F transcription factors have crucial roles in various cellular functions, including cell cycle, DNA replication, DNA repair, cell mitosis, and cell fate. Specifically, E2F6, one of the unique E2F family members, is known to be a pRb-independent transcription repressor of E2F-target genes. In our current study, we explore the role of EBNA3C in regulating E2F6 activities. We observed that EBNA3C plays an important role in inducing E2F6 expression in LCLs. Our study also shows that EBNA3C physically interacts with E2F6 at its amino and carboxy terminal domains and they form a protein complex in human cells. In addition, EBNA3C stabilizes the E2F6 protein and is co-localized in the nucleus. We also demonstrated that both EBNA3C and E2F6 contribute to reduction in E2F1 transcriptional activity. Moreover, E2F1 forms a protein complex with EBNA3C and E2F6, and EBNA3C competes with E2F1 for E2F6 binding. E2F6 is also recruited by EBNA3C to the E2F1 promoter, which is critical for EBNA3C-mediated cell proliferation. These results demonstrate a critical role for E2F family members in EBV-induced malignancies, and provide new insights for targeting E2F transcription factors in EBV-associated cancers as potential therapeutic intervention strategies.

  10. Structural change induced by thermal annealing of red-light-emitting ZnSnF6 • 6H2O:Mn4+ hexahydrate phosphor

    Science.gov (United States)

    Hoshino, Ryosuke; Nakamura, Toshihiro; Adachi, Sadao

    2016-05-01

    Effects of thermal annealing on the red-emitting ZnSnF6 • 6H2O:Mn4+ hexahydrate phosphor properties were investigated using X-ray diffraction measurement (XRD), photoluminescence (PL) analysis, and Raman scattering spectroscopy. Thermal annealing was performed at T a = 50 to 400 °C in air for 1 h. Mn4+-related red emission wavelengths were redshifted about 5 nm after annealing at T a ≥ 200 °C with greatly decreased emission intensities. This change in PL spectral feature was attributed to the dehydration of the hexahydrate phosphor, supported by the XRD and Raman scattering results. The XRD and PL intensity analyses determined thermal decomposition energies of ˜0.3 eV from the ZnSnF6 • 6H2O hexahydrate to anhydrate and of ˜0.9 eV from the ZnSnF6 anhydrate to metallic fluorid/oxide (ZnF2/SnO2). A comparative discussion was given on the PL properties of two different Mn4+-activated phosphors, Ba-IV-F6:Mn4+ anhydrate and Zn-IV-F6 • 6H2O:Mn4+ hexahydrate phosphors with IV = Si, Ge, and Sn.

  11. An X-ray photoelectron spectroscopy study of the products of the interaction of gaseous IrF6 with fine UO2F2

    Directory of Open Access Journals (Sweden)

    Prusakov Vladimir N.

    2007-01-01

    Full Text Available Nuclear fuel reprocessing by fluorination, a dry method of regeneration of spent nuclear fuel, uses UO2F2 for the separation of plutonium from gaseous mixtures. Since plutonium requires special treatment, IrF6 was used as a thermodynamic model of PuF6. The model reaction of the interaction of gaseous IrF6 with fine UO2F2 in the sorption column revealed a change of color of the sorption column contents from pale-yellow to gray and black, indicating the formation of products of such an interaction. The X-ray photoelectron spectroscopy study showed that the interaction of gaseous IrF6 with fine UO2F2 at 125 °C results in the formation of stable iridium compounds where the iridium oxidation state is close to Ir3+. The dependence of the elemental compositions of the layers in the sorption column on the penetration depth of IrF6 was established.

  12. Association between DNA Methylation in Whole Blood and Measures of Glucose Metabolism: KORA F4 Study.

    Directory of Open Access Journals (Sweden)

    Jennifer Kriebel

    Full Text Available Epigenetic regulation has been postulated to affect glucose metabolism, insulin sensitivity and the risk of type 2 diabetes. Therefore, we performed an epigenome-wide association study for measures of glucose metabolism in whole blood samples of the population-based Cooperative Health Research in the Region of Augsburg F4 study using the Illumina HumanMethylation 450 BeadChip. We identified a total of 31 CpG sites where methylation level was associated with measures of glucose metabolism after adjustment for age, sex, smoking, and estimated white blood cell proportions and correction for multiple testing using the Benjamini-Hochberg (B-H method (four for fasting glucose, seven for fasting insulin, 25 for homeostasis model assessment-insulin resistance [HOMA-IR]; B-H-adjusted p-values between 9.2x10(-5 and 0.047. In addition, DNA methylation at cg06500161 (annotated to ABCG1 was associated with all the aforementioned phenotypes and 2-hour glucose (B-H-adjusted p-values between 9.2x10(-5 and 3.0x10(-3. Methylation status of additional three CpG sites showed an association with fasting insulin only after additional adjustment for body mass index (BMI (B-H-adjusted p-values = 0.047. Overall, effect strengths were reduced by around 30% after additional adjustment for BMI, suggesting that this variable has an influence on the investigated phenotypes. Furthermore, we found significant associations between methylation status of 21 of the aforementioned CpG sites and 2-hour insulin in a subset of samples with seven significant associations persisting after additional adjustment for BMI. In a subset of 533 participants, methylation of the CpG site cg06500161 (ABCG1 was inversely associated with ABCG1 gene expression (B-H-adjusted p-value = 1.5x10(-9. Additionally, we observed an enrichment of the top 1,000 CpG sites for diabetes-related canonical pathways using Ingenuity Pathway Analysis. In conclusion, our study indicates that DNA methylation and

  13. Association between DNA Methylation in Whole Blood and Measures of Glucose Metabolism: KORA F4 Study.

    Science.gov (United States)

    Kriebel, Jennifer; Herder, Christian; Rathmann, Wolfgang; Wahl, Simone; Kunze, Sonja; Molnos, Sophie; Volkova, Nadezda; Schramm, Katharina; Carstensen-Kirberg, Maren; Waldenberger, Melanie; Gieger, Christian; Peters, Annette; Illig, Thomas; Prokisch, Holger; Roden, Michael; Grallert, Harald

    2016-01-01

    Epigenetic regulation has been postulated to affect glucose metabolism, insulin sensitivity and the risk of type 2 diabetes. Therefore, we performed an epigenome-wide association study for measures of glucose metabolism in whole blood samples of the population-based Cooperative Health Research in the Region of Augsburg F4 study using the Illumina HumanMethylation 450 BeadChip. We identified a total of 31 CpG sites where methylation level was associated with measures of glucose metabolism after adjustment for age, sex, smoking, and estimated white blood cell proportions and correction for multiple testing using the Benjamini-Hochberg (B-H) method (four for fasting glucose, seven for fasting insulin, 25 for homeostasis model assessment-insulin resistance [HOMA-IR]; B-H-adjusted p-values between 9.2x10(-5) and 0.047). In addition, DNA methylation at cg06500161 (annotated to ABCG1) was associated with all the aforementioned phenotypes and 2-hour glucose (B-H-adjusted p-values between 9.2x10(-5) and 3.0x10(-3)). Methylation status of additional three CpG sites showed an association with fasting insulin only after additional adjustment for body mass index (BMI) (B-H-adjusted p-values = 0.047). Overall, effect strengths were reduced by around 30% after additional adjustment for BMI, suggesting that this variable has an influence on the investigated phenotypes. Furthermore, we found significant associations between methylation status of 21 of the aforementioned CpG sites and 2-hour insulin in a subset of samples with seven significant associations persisting after additional adjustment for BMI. In a subset of 533 participants, methylation of the CpG site cg06500161 (ABCG1) was inversely associated with ABCG1 gene expression (B-H-adjusted p-value = 1.5x10(-9)). Additionally, we observed an enrichment of the top 1,000 CpG sites for diabetes-related canonical pathways using Ingenuity Pathway Analysis. In conclusion, our study indicates that DNA methylation and diabetes

  14. Feeding of Lactobacillus sobrius reduces Escherichia coli F4 levels in the gut and promotes growth of infected piglets

    NARCIS (Netherlands)

    Konstantinov, S.R.; Smidt, H.; Akkermans, A.D.L.; Casini, L.; Trevisi, P.; Mazzoni, M.; Filippi, de S.; Bosi, P.; Vos, de W.M.

    2008-01-01

    The microbial community in the guts of mammals is often seen as an important potential target in therapeutic and preventive interventions. The aim of the present study was to determine whether enterotoxigenic Escherichia coli (ETEC) F4 infection in young animals might be counteracted by a probiotic

  15. 17 CFR 239.34 - Form F-4, for registration of securities of foreign private issuers issued in certain business...

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Form F-4, for registration of securities of foreign private issuers issued in certain business combination transactions. 239.34 Section 239.34 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION FORMS PRESCRIBED UNDER...

  16. Highly Efficient Simplified Organic Light-Emitting Diodes Utilizing F4-TCNQ as an Anode Buffer Layer

    Institute of Scientific and Technical Information of China (English)

    DONG Mu-Sen; WU Xiao-Ming; HUA Yu-Lin; QI Qing-Jin; YIN Shou-Gen

    2010-01-01

    @@ We demonstrate that the electroluminescent performances of organic light-emitting diodes(OLEDs)are significantly improved by evaporating a thin F4-TCNQ film as an anode buffer layer on the ITO anode.The optimum Alq3-based OLEDs with F4-TCNQ buffer layer exhibit a lower turn-on voltage of 2.6 V,a higher brightness of39820cd/m2 at 13 V,and a higher current efficiency of 5.96cd/A at 6 V,which are obviously superior to those of the conventional device(turn-on voltage of 4.1 V,brightness of 18230cd/m2 at 13 V,and maximum current efficiency of 2.74 cd/A at 10 V).Furthermore,the buffered devices with F4-TCNQ as the buffer layer could not only increase the efficiency but also simplify the fabrication process compared with the p-doped devices in which F4-TCNQ is doped into/3-NPB as p-HTL(3.11 cd/A at 7 V).The reason why the current efficiency of the p-doped devices is lower than that of the buffered devices is analyzed based on the concept of doping,the measurement of absorption and photoluminescence spectra of the organic materials,and the current density-voltage characteristics of the corresponding hole-only devices.

  17. Feeding of Lactobacillus sobrius reduces Escherichia coli F4 levels in the gut and promotes growth of infected piglets

    NARCIS (Netherlands)

    Konstantinov, S.R.; Smidt, H.; Akkermans, A.D.L.; Casini, L.; Trevisi, P.; Mazzoni, M.; Filippi, de S.; Bosi, P.; Vos, de W.M.

    2008-01-01

    The microbial community in the guts of mammals is often seen as an important potential target in therapeutic and preventive interventions. The aim of the present study was to determine whether enterotoxigenic Escherichia coli (ETEC) F4 infection in young animals might be counteracted by a probiotic

  18. Azalomycin F4a 2-ethylpentyl ester, a new macrocyclic lactone, from mangrove actinomycete Streptomyces sp.211726

    Institute of Scientific and Technical Information of China (English)

    Gan Jun Yuan; Kui Hong; Hai Peng Lin; Jia Li

    2010-01-01

    Azalomycin F4a 2-ethylpentyl ester,a new 36-membered macrocyclic lactone antibiotic,was isolated from mangrove actinomycete Streptomyces sp.211726.Its structure was elucidated on the basis of spectroscopic data.The compound showed broad-spectrum antifungal activity and moderate cytotoxicity against human colon tumor cell HCT-116.

  19. Sub-6 nm monodisperse hexagonal core/shell NaGdF4 nanocrystals with enhanced upconversion photoluminescence.

    Science.gov (United States)

    Liu, Jing; Chen, Guanying; Hao, Shuwei; Yang, Chunhui

    2017-01-07

    The ability to fabricate lanthanide-doped upconversion nanocrystals (UCNCs) with tailored size and emission profile has fuelled their uses in a broad spectrum of biological applications. Yet, limited success has been met in the preparation of sub-6 nm UCNCs with efficient upconversion photoluminescence (UCPL), which enable high contrast optical bioimaging with minimized adverse biological effects entailed by size-induced rapid clearance from the body. Here, we present a simple and reproducible approach to synthesize a set of monodispersed hexagonal-phase core NaGdF4:Yb/Ln (Ln = Er, Ho, Tm) of ∼3-4 nm and core/shell NaGdF4:Yb/Ln@NaGdF4 (Ln = Er, Ho, Tm) UCNCs of ∼5-6 nm. We show that the core/shell UCNCs can be up to ∼1000 times more efficient than the corresponding core UCNCs due to the effective suppression of surface-related quenching effects for the core. The observation of prolonged PL lifetime for the core/shell than that for the core UCNCs demonstrates the role of the inert shell layer for the protection of the core. The achievement of sub-6 nm NaGdF4 UCNCs with significantly improved luminescence efficiency constitutes a solid step towards high contrast UCPL optical imaging with secured biological safety.

  20. Evaluation of fluoride release from experimental TiF4 and NaF varnishes in vitro

    Science.gov (United States)

    COMAR, Livia Picchi; de SOUZA, Beatriz Martines; GRIZZO, Larissa Tercilia; BUZALAF, Marília Afonso Rabelo; MAGALHÃES, Ana Carolina

    2014-01-01

    Fluoride varnishes play an important role in the prevention of dental caries, promoting the inhibition of demineralization and the increase of remineralization. Objective This study aimed to analyze the amount of fluoride released into water and artificial saliva from experimental TiF4 and NaF varnishes, with different concentrations, for 12 h. Material and Methods Fluoride varnishes were applied on acrylic blocks and then immersed in 10 ml of deionized water and artificial saliva in polystyrene bottles. The acrylic blocks were divided in seven groups (n=10): 1.55% TiF4 varnish (0.95% F, pH 1.0); 3.10% TiF4 varnish (1.90% F, pH 1.0); 3.10% and 4% TiF4 varnish (2.45% F, pH 1.0); 2.10% NaF varnish (0.95% F, pH 5.0); 4.20% NaF varnish (1.90% F, pH 5.0); 5.42% NaF varnish (2.45% F, pH 5.0) and control (no treatment, n=5). The fluoride release was analyzed after 1/2, 1, 3, 6, 9 and 12 h of exposure. The analysis was performed using an ion-specific electrode coupled to a potentiometer. Two-way ANOVA and Bonferroni's test were applied for the statistical analysis (pfluoride than NaF varnishes during the first 1/2 h, regardless of their concentration; 4% TiF4 varnish released more fluoride than NaF varnishes for the first 6 h. The peak of fluoride release occurred at 3 h. There was a better dose-response relationship among the varnishes exposed to water than to artificial saliva. Conclusions The 3.10% and 4% TiF4 -based varnishes have greater ability to release fluoride into water and artificial saliva compared to NaF varnish; however, more studies must be conducted to elucidate the mechanism of action of TiF4 varnish on tooth surface. PMID:24676585

  1. Evaluation of fluoride release from experimental TiF4 and NaF varnishes in vitro.

    Science.gov (United States)

    Comar, Livia Picchi; Souza, Beatriz Martines de; Grizzo, Larissa Tercilia; Buzalaf, Marília Afonso Rabelo; Magalhães, Ana Carolina

    2014-04-01

    Fluoride varnishes play an important role in the prevention of dental caries, promoting the inhibition of demineralization and the increase of remineralization. This study aimed to analyze the amount of fluoride released into water and artificial saliva from experimental TiF4 and NaF varnishes, with different concentrations, for 12 h. Fluoride varnishes were applied on acrylic blocks and then immersed in 10 ml of deionized water and artificial saliva in polystyrene bottles. The acrylic blocks were divided in seven groups (n=10): 1.55% TiF4 varnish (0.95% F, pH 1.0); 3.10% TiF4 varnish (1.90% F, pH 1.0); 3.10% and 4% TiF4 varnish (2.45% F, pH 1.0); 2.10% NaF varnish (0.95% F, pH 5.0); 4.20% NaF varnish (1.90% F, pH 5.0); 5.42% NaF varnish (2.45% F, pH 5.0) and control (no treatment, n=5). The fluoride release was analyzed after 1/2, 1, 3, 6, 9 and 12 h of exposure. The analysis was performed using an ion-specific electrode coupled to a potentiometer. Two-way ANOVA and Bonferroni's test were applied for the statistical analysis (pvarnishes released larger amounts of fluoride than NaF varnishes during the first 1/2 h, regardless of their concentration; 4% TiF4 varnish released more fluoride than NaF varnishes for the first 6 h. The peak of fluoride release occurred at 3 h. There was a better dose-response relationship among the varnishes exposed to water than to artificial saliva. The 3.10% and 4% TiF4 -based varnishes have greater ability to release fluoride into water and artificial saliva compared to NaF varnish; however, more studies must be conducted to elucidate the mechanism of action of TiF4 varnish on tooth surface.

  2. Antistaphylococcal activity of DX-619, a new des-F(6)-quinolone, compared to those of other agents.

    Science.gov (United States)

    Bogdanovich, Tatiana; Esel, Duygu; Kelly, Linda M; Bozdogan, Bülent; Credito, Kim; Lin, Gengrong; Smith, Kathy; Ednie, Lois M; Hoellman, Dianne B; Appelbaum, Peter C

    2005-08-01

    The in vitro activity of DX-619, a new des-F(6)-quinolone, was tested against staphylococci and compared to those of other antimicrobials. DX-619 had the lowest MIC ranges/MIC(50)s/MIC(90)s (microg/ml) against 131 Staphylococcus aureus strains (32), and ciprofloxacin (>32/>32). Raised quinolone MICs were associated with mutations in GyrA (S84L) and single or double mutations in GrlA (S80F or Y; E84K, G, or V) in all S. aureus strains tested. A recent vancomycin-resistant S. aureus (VRSA) strain (Hershey) was resistant to available quinolones and was inhibited by DX-619 at 0.25 microg/ml and sitafloxacin at 1.0 microg/ml. Vancomycin (except VRSA), linezolid, ranbezolid, tigecycline, and quinupristin-dalfopristin were active against all strains, and teicoplanin was active against S. aureus but less active against coagulase-negative staphylococci. DX-619 produced resistant mutants with MICs of 1 to >32 microg/ml after 32 microg/ml for ciprofloxacin, sitafloxacin, moxifloxacin, and gatifloxacin. DX-619 and sitafloxacin were also more active than other tested drugs against selected mutants and had the lowest mutation frequencies in single-step resistance selection. DX-619 and sitafloxacin were bactericidal against six quinolone-resistant (including the VRSA) and seven quinolone-susceptible strains tested, whereas gatifloxacin, moxifloxacin, levofloxacin, and ciprofloxacin were bactericidal against 11, 10, 7, and 5 strains at 4x MIC after 24 h, respectively. DX-619 was also bactericidal against one other VRSA strain, five vancomycin-intermediate S. aureus strains, and four vancomycin-intermediate coagulase-negative staphylococci. Linezolid, ranbezolid, and tigecycline were bacteriostatic and quinupristin-dalfopristin, teicoplanin, and vancomycin were bactericidal against two, eight, and nine strains, and daptomycin and oritavancin were rapidly bactericidal against all strains, including the VRSA. DX-619 has potent in vitro activity against staphylococci, including

  3. Effect of an electron beam irradiation on optical and luminescence properties of LiBaAlF6 single crystals

    Science.gov (United States)

    Ogorodnikov, I. N.; Pustovarov, V. A.; Omelkov, S. I.; Kirm, M.

    2017-07-01

    Paper reports the effect of a 10 keV, 110 keV and 10 MeV electron beam irradiation on optical and luminescence properties of LiBaAlF6 (LBAF) single crystals at 10, 90, and 293 K. Five absorption bands at 2.0, 3.2, 4.3, 4.9 and 5.5 eV were revealed in irradiated crystals in the energy range of 1.2-9.5 eV. Several PL emission bands (1.7-1.8, 2.2 and 2.5-3.5 eV) related to defects were found in the luminescence spectra at room temperature, while only one luminescence band at E = 2.2 eV appears at T = 90 K in LBAF crystals after a 10 MeV electron bombardment. The PL excitation spectra and time-response for these emission bands were studied at 10, 90, and 293 K. Thermoluminescence (TL) of irradiated crystals was studied in the temperature range of 90-740 K. New TL glow peaks at 166, 530 and 670 K were revealed and their parameters were determined. Temperature dependence of relative photoluminescence yield recorded monitoring emission at the 1.87 and 2.23 eV in the temperature range from 130 to 450 K, were fitted using five quenching processes related to TL glow peaks revealed in our research. Significant similarity in the manifestation of radiation-induced defects for LBAF and previously studied LiBaF3 single crystals is noted. The effect of an electron beam irradiation on optical and luminescence properties of LBAF single crystals and possible origin of the radiation defects were discussed.

  4. Analysis of Isotopic Abundance of SeF6 by Mass Spectrometry%六氟化硒中同位素丰度质谱分析

    Institute of Scientific and Technical Information of China (English)

    窦秀英; 李胡平; 薛永珍

    2004-01-01

    Natural Se element have six kinds of isotope 74Se, 76Se, 77Se, 78Se, 80Se and 82Se,and the natural content of 74Se is 0. 87%. After being shot by neutron, 78Se isotope can be changed to be short decayed period to radioisotope. The radiation source made up fro mhigh density 75Se isotope, which content is more than 90%, is quite valuable for application of agriculture and nuclear medical science and such aspect. This study mainly presents experimental research on gas mass spectrograph, establishes the analysis method for isotope content of Se F6, gives best temperature needed to eradicate impurity from sample,relative strength of Se F6 fragment ion summit under the best electron energy, characteristic summit and data processing technique etc. Using this method, the measuring accuracy of 74Se isotope content of natural Se F6 is 0.4%. The technique can also be applied to examine products.

  5. Efficient polymer light-emit ting diodes with violet blue emission based on blends of PSiF6-PPP and PSiFC6C6

    Institute of Scientific and Technical Information of China (English)

    TIAN Renyu; MO Yueqi; PENG Junbiao

    2006-01-01

    Efficient polymer light-emitting diodes (PLEDs) with violet blue emission were fabricated using blends of copolymers of paraphenylene-cosilafluorene (PSiF6-PPP) and polymer of poly (9,9'alkyl-3,6-silafluorene) (PSiFC6C6). The performances of the devices are sensitive to the blend ratio.When the mass ratio of PSiF6-PPP to PSiFC6C6 is 1.96% at luminance of 105 cd.m-2, its electroluminescent (EL) spectrum peaks at 398 nm and full width at half maximum is 67 nm. The improvements of the device performances were due to the energy transfer from PSiFC6C6 to PSiF6-PPP and the balanced injection of electrons and holes.

  6. Monolayer compression induces fluidization in binary system of partially fluorinated alcohol (F4H11OH) with DPPC.

    Science.gov (United States)

    Nakahara, Hiromichi; Ohmine, Aya; Kai, Shoko; Shibata, Osamu

    2013-01-01

    A two-component Langmuir monolayer consisting of (perfluorobutyl)undecanol (F4H11OH) and dipalmitoylphosphatidylcholine (DPPC), a major component of pulmonary surfactants in mammals, has been investigated at the air-water interface. The binary monolayer has been systematically examined from both thermodynamic and morphological perspectives. The excess Gibbs free energy of mixing has been calculated from surface pressure (π)-molecular area (A) isotherms, and the results indicate that the miscibility of the two-component system shows a maximum in thermodynamical stability when the mole fraction (X(F4H11OH)) is 0.3. Results from a two-dimensional phase diagram (π vs. X(F4H11OH)) are consistent with these findings and depict the degree of miscibility resulting from the variation in the transition and collapse pressures relative to the concentration of X(F4H11OH). The miscibility is also supported by in situ Brewster angle microscopy and fluorescence microscopy, as well as ex situ atomic force microscopy for the system after transfer onto a mica substrate. Aside from temperature, a known driving force for the fluidization of DPPC monolayers is a change in surface composition caused by the addition of additive molecules. In the present study, however, the fluidization is driven by increasing surface pressures even at constant X(F4H11OH). Such a fluidization is a fascinating property when looked at in context of its potential implications for pulmonary replacement therapy, and hence, this study provides a fundamental insight into designing fluorinated materials for biomedical use.

  7. Investigation of neutronic performance of a peaceful nuclear explosive reactor (PACER) evaluating UF4 and ThF4 nuclides

    Indian Academy of Sciences (India)

    Selahaddin Orhan Akansu; Nafiz Kahraman

    2004-08-01

    In this study, neutronic behaviour of a peaceful nuclear explosion reactor (PACER) producing approx 1.2 GWe power from fusion explosions is analysed considering ThF4 and UF4 as fissile zones. UF4 and ThF4 are put in to the system adjacent to the inner-side of the flibe coolant zone positions (distance between explosive region and fuel zone, DR = 50, 100, 200, 400, 500 and 700 cm). Flibe percentages are taken to be 25, 50, 75 and 100%. It is found that optimum combinations of fissile zone thickness, coolant zone position and coolant percentages are 10 cm, 200 cm and 25% flibe for UF4 and 10 cm, 50 cm and 25% flibe for ThF4. The behaviour of fuels mentioned above has been observed over a period of 30 years at discrete time intervals, $\\Delta t = 30$ days. In the case of UF4; values at DR = 200 cm reach 5.35, 5.22, 4.88, and 4.88 from 3.12, 2.98, 2.83 and 2.83, for 25, 50, 75, 100% flibe respectively. For ThF4 at DR = 50 cm, values reach from 1.61, 1.54, 1.50 and 1.46 to 1.93, 2.00, 2.04 and 1.99 for 25, 50, 75, 100% flibe respectively. Cumulative fissile fuel breeding (CFFE) values reach up to 5.5 from 0.7 at DR = 200 and 25% case for UF4, and up to 6.36% from 0%, at DR = 50 and 25% flibe, for ThF4, at the end of the operation period.

  8. Red-emitting phosphor Rb2TiF6:Mn4+ with high thermal-quenching resistance for wide color-gamut white light-emitting diodes

    Science.gov (United States)

    Wang, Zhengliang; Yang, Zhiyu; Tan, Huiying; Brik, Mikhail G.; Zhou, Qiang; Chen, Guo; Liang, Hongbin

    2017-10-01

    Red-emitting phosphor plays a critical role in improving performance of the phosphor-converted white light-emitting diodes (pc-WLEDs). Herein, a red-emitting phosphor, Rb2TiF6:Mn4+, was synthesized via the ion exchange method under mild condition. The crystal structure and morphology were characterized by the powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The Rietveld refinements of Rb2TiF6:Mn4+ indicate that this sample is of single phase with hexagonal crystal structure. The as-prepared Rb2TiF6:Mn4+ has sharp red emissions with broad excitation band at ∼460 nm. The luminescent behavior of Mn4+ was discussed in detail. The temperature-dependent emission spectra of Rb2TiF6:Mn4+ indicate that this phosphor shares high thermal quenching resistance and excellent color stability. A series of WLEDs with tunable color rendering index and color temperature were fabricated by combining commercial Y3Al5O12:Ce3+ and Rb2TiF6:Mn4+ on blue GaN-LED chips. With the addition of Rb2TiF6:Mn4+, WLED with wide gamut was obtained with low color temperature (3123 K), high color rendering index (91.5) and high luminous efficacy (187.9 lm/W). These findings show this phosphor could be a promising commercial red phosphor in wide color-gamut WLEDs.

  9. Increasing the Brønsted acidity of Ph2PO2H by the Lewis acid B(C6F5)3. Formation of an eight-membered boraphosphinate ring [Ph2POB(C6F5)2O]2.

    Science.gov (United States)

    Kather, Ralf; Rychagova, Elena; Sanz Camacho, Paula; Ashbrook, Sharon E; Woollins, J Derek; Robben, Lars; Lork, Enno; Ketkov, Sergey; Beckmann, Jens

    2016-09-21

    Autoprotolysis of the metastable acid (C6F5)3BOPPh2OH, prepared in situ by the reaction of the rather weak Brønsted acid Ph2PO2H with the strong Lewis acid B(C6F5)3, gave rise to the formation of the eight-membered ring [Ph2POB(C6F5)2O]2 and C6F5H. The conjugate base was isolated as stable sodium crown ether salt [Na(15-crown-5)][Ph2PO2B(C6F5)3].

  10. Water Production in Comets C/2011 L4 (PanSTARRS) and C/2012 F6 (Lemmon) with SOHO/SWAN

    Science.gov (United States)

    Combi, M.; Bertaux, J.-L.; Quémerais, E.; Ferron, S.; Mäkinen, J. T. T.; Aptekar, G.

    2013-09-01

    Comets C/2011 L4 (PanSTARRS) and C/2012 F6 (Lemmon) were observed throughout their 2013 apparitions with the SWAN all-sky Lyman-α camera on the Solar and Heliosphere Observatory (SOHO) satellite, which has been in a halo orbit around the L1 Earth-Sun Lagrange point since early 1996. The maximum production rates were ~1 x 1030 molecules s-1 for both comets. The activities of both comets were asymmetric about perihelion. C/2011 L4 (PanSTARRS) was more active before perihelion but C/2012 F6 (Lemmon) was more active after perihelion.

  11. Do monkey F5 mirror neurons show changes in firing rate during repeated observation of natural actions?

    Science.gov (United States)

    Kilner, J M; Kraskov, A; Lemon, R N

    2014-03-01

    Mirror neurons were first discovered in area F5 of macaque monkeys. In humans, noninvasive studies have demonstrated an increased blood oxygen level-dependent (BOLD) signal in homologous motor areas during action observation. One approach to demonstrating that this indicates the existence of mirror neurons in humans has been to employ functional (f)MRI adaptation to test whether the same population of neurons is active during both observation and execution conditions. Although a number of human studies have reported fMRI adaptation in these areas, a recent study has shown that macaque mirror neurons do not attenuate their firing rate with two repetitions. Here we investigated whether mirror neurons modulate their firing rate when monkeys observed the same repeated natural action multiple times. We recorded from 67 mirror neurons in area F5 of two macaque monkeys while they observed an experimenter perform a reach-to-grasp action on a small food reward using a precision grip. Although no changes were detectable for the first two repetitions, we show that both the firing rate and the latency at which mirror neurons discharged during observation were subtly modulated by the repetition of the observed action over 7-10 trials. Significant adaption was mostly found in the period immediately before the grasp was performed. We also found that the local field potential activity in F5 (beta-frequency range, 16-23 Hz), which is attenuated during action observation, also showed systematic changes with repeated observation. These LFP changes occurred well in advance of the mirror neuron adaptation. We conclude that macaque mirror neurons can show intra-modal adaptation, but whether this is related to fMRI adaptation of the BOLD signal requires further investigation.

  12. N-terminal residues of an HIV-1 gp41 membrane-proximal external region antigen influence broadly neutralizing 2F5-like antibodies

    Institute of Scientific and Technical Information of China (English)

    Dezhi Li; Jie Liu; Li Zhang; Tianshu Xu; Junheng Chen; Liping Wang; Qi Zhao

    2015-01-01

    The Human immunodeficiency virus type 1(HIV-1) gp41 membrane proximal external region(MPER) is targeted by broadly neutralizing antibodies(e.g. 2F5, 4E10, Z13 e and m66.6), which makes this region a promising target for vaccine design. One strategy to elicit neutralizing antibodies against the MPER epitope is to design peptide immunogens mimicking neutralization structures. To probe 2F5-like neutralizing antibodies, two yeast-displayed antibody libraries from peripheral blood mononuclear cells from a HIV-1 patient were screened against the 2F5 epitope peptide SP62. Two 2F5-like antibodies were identified that specifically recognized SP62. However,these antibodies only weakly neutralized HIV-1 primary isolates. The epitopes recognized by these two 2F5-like antibodies include not only the 2F5 epitope(amino acids(aa) 662–667 in the MPER)but also several other residues(aa 652–655) locating at the N-terminus in SP62. Experimental results suggest that residues of SP62 adjacent to the 2F5 epitope influence the response of broadly neutralizing 2F5-like antibodies in vaccination. Our findings may aid the design of vaccine immunogens and development of therapeutics against HIV-1 infection.

  13. N-terminal residues of an HIV-1 gp41 membrane-proximal external region antigen influence broadly neutralizing 2F5-like antibodies.

    Science.gov (United States)

    Li, Dezhi; Liu, Jie; Zhang, Li; Xu, Tianshu; Chen, Junheng; Wang, Liping; Zhao, Qi

    2015-12-01

    The Human immunodeficiency virus type 1 (HIV-1) gp41 membrane proximal external region (MPER) is targeted by broadly neutralizing antibodies (e.g. 2F5, 4E10, Z13e and m66.6), which makes this region a promising target for vaccine design. One strategy to elicit neutralizing antibodies against the MPER epitope is to design peptide immunogens mimicking neutralization structures. To probe 2F5-like neutralizing antibodies, two yeast-displayed antibody libraries from peripheral blood mononuclear cells from a HIV-1 patient were screened against the 2F5 epitope peptide SP62. Two 2F5-like antibodies were identified that specifically recognized SP62. However, these antibodies only weakly neutralized HIV-1 primary isolates. The epitopes recognized by these two 2F5-like antibodies include not only the 2F5 epitope (amino acids (aa) 662-667 in the MPER) but also several other residues (aa 652-655) locating at the N-terminus in SP62. Experimental results suggest that residues of SP62 adjacent to the 2F5 epitope influence the response of broadly neutralizing 2F5-like antibodies in vaccination. Our findings may aid the design of vaccine immunogens and development of therapeutics against HIV-1 infection.

  14. E2F-5, a new E2F family member that interacts with p130 in vivo

    OpenAIRE

    Hijmans, E.M.; Voorhoeve, P.M.; Beijersbergen, R.L.; Veer, L J Van't; Bernards, R.A.

    1995-01-01

    E2F DNA binding sites are found in a number of genes whose expression is tightly regulated during the cell cycle. The activity of E2F transcription factors is regulated by association with specific repressor molecules that can bind and inhibit the E2F transactivation domain. For E2F-1, E2F-2, and E2F-3, the repressor is the product of the retinoblastoma gene, pRb. E2f-4 interacts with pRb-related p107 and not with pRb itself. Recently, a cDNA encoding a third member of the retinoblastoma gene...

  15. Theoretical study of Pr3+:ZBLAN upconversion ultraviolet fiber laser based on 4f5d state

    Institute of Scientific and Technical Information of China (English)

    Aiping Fang; Zhenwen Dai; Tao Luo; Guijuan Sun; Lijun Wang; Zhankui Jiang

    2005-01-01

    A theoretical study of the kinetics of two-step-excitation upconversion ultraviolet cw fiber laser based on the 4f5d state in Pr3+:ZBLAN is performed using steady population rate equations and light propagation equations. Under different Pr3+ concentrations, the dependence of the threshold pump powers on the other pump power, the variations of laser output power with reflectivity of output coupler, pump powers and fiber length as well as the dependence of the optimum fiber length on pump powers are investigated.The results predict some optimum laser parameters for maximizing output power.

  16. FASINEX (Frontal Air-Sea Interaction Experiment) January - June 1986. FASINEX Moored Current Meter Array Data Report Including WHOI (Woods Hole Oceanographic Institution) Meteorologically Instrumented Surface Moorings (F2-845, F4-846, F6-847, F8-848, F10-849) and WHOI Long Term Subsurface Moorings (F1-829, F12-830)

    Science.gov (United States)

    1988-12-01

    11. Kilometer separation of moorings. 17 12. Geographic locations of FASINEX moorings. 18 13. FASINEX Buoy with Meteorological Sensors. 24 14. Surface...array. 17 IN roD.󈨔. 750 UNI TED 40. 4 35* -35* FASINEX 25 AREA~ 2 / 75 70 650 60. 0 N Z8o N Uo II 066 V*N Longitude Figure 12. Geographic positioning...allows for the 4th segement of the data to match the FASINEX time period. The time periods for these segments are October 29, 1984 - March 1, 1985

  17. The OD/OH Isotope Ratio in Comets 8P/Tuttle and C/2012 F6 (Lemmon)

    Science.gov (United States)

    Rousselot, Philippe; Jehin, Emmanuel; Hutsemekers, Damien; Manfroid, Jean; Decock, Alice; Bockelee-Morvan, Dominique

    2016-10-01

    The determination of isotopic ratios in solar system objects is an important source of information about their origin, especially for comets. Among these ratios the D/H is of particular importance because of its sensitivity to fractionation processes and physical environment, and the abundance of hydrogen in the solar system. The main molecule used to derive this ratio in comets is water. So far, apart water, only HCN has permitted to derive D/H ratio and not only upper limits.Most of the existing determinations of D/H in water molecules have been obtained by spectroscopic observations of water lines in the sub-mm or near infrared range [1,2]. So far only one measurement has been based on OD/OH emission lines radicals in the near-UV [3] and another one on the Lyman-alpha D emission [4]. In situ measurements have also been obtained in comets 1P/Halley and 67P/Churyumov-Gerasimenko using mass spectrometer [5,6,7,8].In this work we have used the OH and OD ultraviolet bands at 310 nm observed with the ESO 8-m Very Large Telescope feeding the Ultraviolet-Visual Echelle Spectrograph (UVES) for measuring the D/H ratio in comets 8P/Tuttle and C/2012 F6 (Lemmon). The OH and OD being the photodissociation products of H2O and HDO such observations allow to derive D/H ratio for water molecules. This work constitutes an independant determination of the D/H ratios already published for these comets and based on observations performed in the sub-mm and near infrared range of H2O and HDO lines. We present our modeling, data analysis and numerical values obtained for this ratio.[1] D. Bockelée-Morvan et al., 2015, SSR 197, 47-83 [2] N. Biver et al., 2016, A&A 589, id A78, 11p [3] D. Hutsemékers et al., 2008, A&A 490, L31 [4] H.A. Weaver et al., 2008, LPI Contributions 1405, 8216 [5] H. Balsiger, K. Altwegg, J. Geiss, 1995, JGR 100, 5827 [6] P. Eberhardt et al., 1995, A&A 302, 301 [7] R.H. Brown et al., 2012, PSS 60, 166 [8] K. Alwegg et al., 2015, Science 347, article id. 1261952

  18. 含色心BaMgF4晶体电子结构的研究%Electronic Structures of BaMgF4 Crystal with F Color Centres

    Institute of Scientific and Technical Information of China (English)

    康玲玲; 刘廷禹; 张启仁; 徐灵芝

    2011-01-01

    Electronic structure of BaMgF4 crystal containing F color centers is studied within the framework of fully relativistic selfconsistent Dirac-Slater theory, using a numerically discrete variational (DV-Xα) method.2p state of H atom is added into the program.It is concluded that energy levels of F color center are located in forbidden band of the crystal.Optical transition energy from ground state to excited state of the F color center is 5.12 eV, which corresponds to 242 nm absorption bands.They are well consisted with experiments.Absorption bands resulted from an F color center in BaMgF4 crystal are located in 236 -274 nm.%运用相对论性的密度泛函离散变分法(DV-X)研究BaMgF4晶体中F型色心的电子结构.计算中采用冻结原子核的H原子模拟F心,在DV-Xα源程序增加H原子2p态,使F心激发态的计算结果在物理上更加合理.计算结果表明,F心的基态和激发态均出现在禁带中;并用过渡态的方法计算得到F心的电子从基态到激发态的光学跃迁能量为5.12eV,对应242nm处的吸收带,计算结果与实验结果吻合得很好,因此,推测F心在BaMgF4晶体中引起236~274 nm的吸收.

  19. Sodium acetate assisted hydrothermal growth of dumbbell-like β -NaGdF4 nanobundles: Morphology control and products transformation

    Science.gov (United States)

    Wu, Kelu; Wang, Yi-Yan; Xia, Tian-Long

    2017-08-01

    Hierarchical β -NaGdF4 nanobundles are synthesized through a facile hydrothermal method with the use of sodium acetate (NaAc). A NaGdF4-GdF3-NaGdF4 products transformation with the increase of fluoride source (NaF) is observed. Results show that NaAc is the key factor in the synthesis of β -NaGdF4 at a low NaF/Gd3+ ratio and NaAc also plays a significant role in the formation of the hierarchical morphology. Meanwhile, the size of nanobundles increases with the increased ratio of NaF/NaAc. With altering the ratio of reactants, dumbbell-like, urchin-like or rod-like β -NaGdF4 nanobundles are obtained. The photoluminescent properties of β -NaGdF4: 2%Eu3+ are also measured.

  20. C2F6/O2/Ar Plasma Chemistry of 60 MHz/2 MHz Dual-Frequency Discharge and Its Effect on Etching of SiCOH Low-k Films%C2F6/O2/Ar Plasma Chemistry of 60 MHz/2 MHz Dual-Frequency Discharge and Its Effect on Etching of SiCOH Low-k Films

    Institute of Scientific and Technical Information of China (English)

    袁颖; 叶超; 陈天; 葛水兵; 刘卉敏; 崔进; 徐轶君; 邓艳红; 宁兆元

    2012-01-01

    This work investigated C2F6/O2/Ar plasma chemistry and its effect on the etching characteristics of SiCOH low-k dielectrics in 60 MHz/2 MHz dual-frequency capacitively coupled discharge. For the C2F6/Ar plasma, the increase in the low-frequency (LF) power led to an increased ion impact, prompting the dissociation of C2F6 with higher reaction energy. As a result, fluorocarbon radicals with a high F/C ratio decreased. The increase in the discharge pressure led to a decrease in the electron temperature, resulting in the decrease of C2F6 dissociation. For the C2F6/O2/Ar plasma, the increase in the LF power prompted the reaction between 02 and C2F6, resulting in the elimination of CF3 and CF2 radicals, and the production of an F-rich plasma environment. The F-rich plasma improved the etching characteristics of SiCOH low-k films, leading to a high etching rate and a smooth etched surface.

  1. Fluoroantimonic acid hexahydrate (HSbF6-6H2O) catalysis: The ring-opening polymerization of epoxidized soybean oil

    Science.gov (United States)

    Ring-opening polymerization of epoxidized soybean oil (ESO) catalyzed by a super acid, fluroantimonic acid hexahydrate (HSbF6-6H2O), in ethyl acetate was conducted in an effort to develop useful biodegradable polymers. The resulting polymerized ESO (SA-RPESO) were characterized by using infrared (IR...

  2. Absolute Generalized Oscillator Strength Profile of Negative Ion Resonance at 8.9eV in C2F6

    Institute of Scientific and Technical Information of China (English)

    FAN Xiao-Wei; GENG Zhen-Duo; ZHANG Yan-Song; K. T. Leung

    2005-01-01

    @@ A temporary negative ion resonance at 8.gev in C2F6 has been clearly identified using angle-resolved electronenergy loss spectroscopy at 2.5kev impact energy, and can be attributed to electron capture into 12a1u, 12a1g, 22a2u, and 12eg virtual molecular orbitals.

  3. Narrow-band red emitting phosphor BaTiF6:Mn(4+): preparation, characterization and application for warm white LED devices.

    Science.gov (United States)

    Gao, Xiaoli; Song, Yan; Liu, Guixia; Dong, Xiangting; Wang, Jinxian; Yu, Wensheng

    2016-11-28

    As a new class of non-rare-earth red phosphors for high-efficiency warm white light-emitting diodes (white LEDs), Mn(4+) ion activated fluoride compounds have been extensively investigated recently and hold the potential to supersede commercial rare earth doped nitride phosphors. Herein, a series of Mn(4+) ions doped BaTiF6 phosphors have been prepared via the hydrothermal route using citric acid as a surfactant. After a systematic investigation, we illustrate the effects of reaction time, nominal concentration of HF solution, and reaction temperature on the luminescence performance of the phosphor. The BaTiF6:Mn(4+) phosphor generates narrow red emission, which is highly perceived by the human eyes and leads to excellent chromatic saturation of red emission spectra. Simultaneously, concentration and thermal quenching are investigated systematically, and the quenching mechanisms are elucidated in detail. Employing BaTiF6:Mn(4+) as a red phosphor, we fabricate a high-performance white LED with low correlated color temperature of 3974 K, high color rendering index of 90.6 and luminous efficacy of 132.54 lm W(-1). Based on the improvement in correlated color temperature and color rendering index, the BaTiF6:Mn(4+) red phosphor supplements the deficiency of LEDs fabricated by combining blue chips and only YAG:Ce(3+), which suggests that it is a promising commercial red phosphor in warm white LEDs.

  4. Impact of hydrostatic pressure on the crystal structure and photoluminescence properties of Mn4+-doped BaTiF6 red phosphor.

    Science.gov (United States)

    Wang, Yonggang; Wen, Ting; Tang, Lingyun; Yang, Liuxiang; Yang, Wenge; Zhao, Yusheng

    2015-04-28

    High-efficiency red phosphors with non-rare-earth activators are emerging as an alternative for next generation solid-state warm white LEDs. Their optical properties depend strongly on the local site symmetry and the crystal field strength. Herein we present the pressure tuning of structural and photoluminescence (PL) properties of Mn(4+)-doped BaTiF6 up to 40 GPa. In situ high pressure synchrotron X-ray diffraction, Raman and PL spectroscopy studies show that the crystal symmetry changes from trigonal at ambient pressure to monoclinic from 0.5 GPa and triclinic above 14 GPa, attributed to the distortion of (Ti/Mn)F6 octahedra. The red emission peaks shift monotonically to longer wavelengths due to the reinforced crystal field strength within MnF6 octahedra as pressure increases. A detailed comparison of emission shift rate, PL intensity and FWHM between Mn(4+)-doped BaTiF6 and ruby (Cr(3+)-doped Al2O3) was performed using neon pressure transmission medium. This demonstration provides not only an efficient way to artificially tune the emission properties of practically useful phosphors by means of hydrostatic pressure, but also alternative candidates as potential pressure gauges for high pressure techniques.

  5. Supramolecular Functionalities Influence the Thermal Properties, Interactions and Conductivity Behavior of Poly(ethylene glycol/LiAsF6 Blends

    Directory of Open Access Journals (Sweden)

    Shiao-Wei Kuo

    2013-07-01

    Full Text Available In this study, we tethered terminal uracil groups onto short-chain poly(ethylene glycol (PEG to form the polymers, uracil (U-PEG and U-PEG-U. Through AC impedance measurements, we found that the conductivities of these polymers increased upon increasing the content of the lithium salt, LiAsF6, until the Li-to-PEG ratio reached 1:4, with the conductivities of the LiAsF6/U-PEG blends being greater than those of the LiAsF6/U-PEG-U blends. The ionic conductivity of the LiAsF6/U-PEG system reached as high as 7.81 × 10−4 S/cm at 30 °C. Differential scanning calorimetry, wide-angle X-ray scattering, 7Li nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy revealed that the presence of the uracil groups in the solid state electrolytes had a critical role in tuning the glass transition temperatures and facilitating the transfer of Li+ ions.

  6. E2F-6: a novel member of the E2F family is an inhibitor of E2F-dependent transcription

    DEFF Research Database (Denmark)

    Cartwright, P; Müller, H; Wagener, C;

    1998-01-01

    promoter (TTTCGCGC). In contrast to the other members of the E2F family, ectopic expression of E2F-6 inhibits transcription from promoters possessing E2F recognition sites rather than activating transcription. In addition, overexpression of E2F-6 suppresses the transactivational effects of coexpression......The E2F family of transcription factors are essential for the regulation of genes required for appropriate progression through the cell cycle. Five members of the E2F family have been previously reported, namely E2F1-5. All five are key elements in transcriptional regulation of essential genes......, and they can be divided into two functional groups, those that induce S-phase progression when overexpressed in quiescent cells (E2Fs 1-3), and those that do not (E2Fs 4-5). Here, we describe the identification of a novel member of this family, which we refer to as E2F-6. E2F-6 shares significant homology...

  7. 40 CFR Table F-4 to Subpart F of... - Estimated Mass Concentration Measurement of PM2.5 for Idealized Coarse Aerosol Size Distribution

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Estimated Mass Concentration Measurement of PM2.5 for Idealized Coarse Aerosol Size Distribution F Table F-4 to Subpart F of Part 53... Equivalent Methods for PM2.5 Pt. 53, Subpt. F, Table F-4 Table F-4 to Subpart F of Part 53—Estimated Mass...

  8. Saccharomyces cerevisiae decreases inflammatory responses induced by F4+ enterotoxigenic Escherichia coli in porcine intestinal epithelial cells.

    Science.gov (United States)

    Zanello, Galliano; Meurens, François; Berri, Mustapha; Chevaleyre, Claire; Melo, Sandrine; Auclair, Eric; Salmon, Henri

    2011-05-15

    Probiotic yeasts may provide protection against intestinal inflammation induced by enteric pathogens. In piglets, infection with F4+ enterotoxigenic Escherichia coli (ETEC) leads to inflammation, diarrhea and intestinal damage. In this study, we investigated whether the yeast strains Saccharomyces cerevisiae (Sc, strain CNCM I-3856) and S. cerevisiae variety boulardii (Sb, strain CNCM I-3799) decreased the expression of pro-inflammatory cytokines and chemokines in intestinal epithelial IPI-2I cells cultured with F4+ ETEC. Results showed that viable Sc inhibited the ETEC-induced TNF-α gene expression whereas Sb did not. In contrast, killed Sc failed to inhibit the expression of pro-inflammatory genes. This inhibition was dependent on secreted soluble factors. Sc culture supernatant decreased the TNF-α, IL-1α, IL-6, IL-8, CXCL2 and CCL20 ETEC-induced mRNA. Furthermore, Sc culture supernatant filtrated fraction yeast strains onto inflammation.

  9. Remaining Sites Verification Package for the 1607-F4 Sanitary Sewer System, Waste Site Reclassification Form 2004-131

    Energy Technology Data Exchange (ETDEWEB)

    L. M. Dittmer

    2007-12-03

    The 1607-F4 waste site is the former location of the sanitary sewer system that serviced the former 115-F Gas Recirculation Building. The system included a septic tank, drain field, and associated pipeline that were in use from 1944 to 1965. The 1607-F4 waste site received unknown amounts of sanitary sewage from the 115-F Gas Recirculation Building and may have potentially contained hazardous and radioactive contamination. In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River.

  10. Infrared to near-infrared and visible upconversion photoluminescence of LiYbF4∶Er3+ nanorods

    Institute of Scientific and Technical Information of China (English)

    LIU Wangdong; LI Wenbin; TANG Haibo; ZHAO Mingzhuo

    2013-01-01

    Colloidal LiYbF4∶Er3+ nanorods were synthesized in an aqueous system which had the ratio of length to diameter of~2.These LiYbF4∶Er3+ nanorods emitted intense upconversion light under excitation of infrared at 1488 nm.Importantly,the intensities of two-and three-photon anti-Stokes upconversion PL bands were observed which were comparable to that of the Stokes emission under excitation with low power density.The plots of excitation power density versus emission intensity indicated that all the emissions centered at 549,668,and 978 nm took a two-photon upconversion process.However,it could be simply deduced that the energy of two photons of 1488 nm were inadequate to produce a photon of 668 or 549 nm.For this conflict,the shape and saturation effects in the intermediate energy states were introduced to demonstrate the corresponding upconversion processes.

  11. View-based encoding of actions in mirror neurons of area f5 in macaque premotor cortex.

    Science.gov (United States)

    Caggiano, Vittorio; Fogassi, Leonardo; Rizzolatti, Giacomo; Pomper, Joern K; Thier, Peter; Giese, Martin A; Casile, Antonino

    2011-01-25

    Converging experimental evidence indicates that mirror neurons in the monkey premotor area F5 encode the goals of observed motor acts [1-3]. However, it is unknown whether they also contribute to encoding the perspective from which the motor acts of others are seen. In order to address this issue, we recorded the visual responses of mirror neurons of monkey area F5 by using a novel experimental paradigm based on the presentation of movies showing grasping motor acts from different visual perspectives. We found that the majority of the tested mirror neurons (74%) exhibited view-dependent activity with responses tuned to specific points of view. A minority of the tested mirror neurons (26%) exhibited view-independent responses. We conclude that view-independent mirror neurons encode action goals irrespective of the details of the observed motor acts, whereas the view-dependent ones might either form an intermediate step in the formation of view independence or contribute to a modulation of view-dependent representations in higher-level visual areas, potentially linking the goals of observed motor acts with their pictorial aspects. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Luminescent properties of Ce3+-doped transparent oxyfluoride glass ceramics containing BaGdF5 nanocrystals

    Institute of Scientific and Technical Information of China (English)

    王倩; 欧阳绍业; 张为欢; 杨斌; 张约品; 夏海平

    2015-01-01

    The transparent oxyfluoride glass ceramics containing BaGdF5 nanocrystals were prepared with a composition of 42SiO2-12Na2O-16Al2O3-24BaF2-4Gd2O3-2CeF3 (mol.%) by thermal treatment technology. The typical DSC curve, X-ray diffraction (XRD) and transmission electron microscopy (TEM) patterns were measured. The transmission spectra and luminescent properties were in-vestigated. The decay times of the Gd3+ions at 312 nm excited with 275 nm for the Ce3+ions doped glass and glass ceramics speci-mens and the energy transfer process between Gd3+ions and Ce3+ions were also studied. The XRD analysis and the TEM images confirmed the generation of the spherical BaGdF5 nanocrystals. Compared with the PG specimen, the intensity of the luminescence spectra of the glass ceramics specimens was apparently enhanced with the heat treatment temperature increasing, and a blue shift in the excitation spectra and the emission spectra of glass ceramics specimens was obviously observed. In the fluorescence decay curves of the Gd3+ions, it could be obviously observed that the fluorescent intensity decays in the Ce3+ions doped glass and glass ceramics specimens decreased rapidly with the increase of the heat treatment temperature. In addition, the energy transfer efficiency from Gd3+ions to Ce3+ions was also calculated.

  13. phi3 theory with F_4 flavor symmetry in 6-2\\epsilon dimensions: 3-loop renormalization and conformal bootstrap

    OpenAIRE

    Pang, Y; Rong, J.(George P. & Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, TX, 77843, U.S.A.); N. Su

    2016-01-01

    We consider $\\phi^3$ theory in $6-2\\epsilon$ with $F_4$ global symmetry. The beta function is calculated up to 3 loops, and a stable unitary IR fixed point is observed. The anomalous dimensions of operators quadratic or cubic in $\\phi$ are also computed. We then employ conformal bootstrap technique to study the fixed point predicted from the perturbative approach. For each putative scaling dimension of $\\phi$ ($\\Delta_{\\phi})$, we obtain the corresponding upper bound on the scaling dimension ...

  14. Comprehensive study on different crystal field environments in highly efficient NaLaF4:Er3+ upconversion phosphor

    Science.gov (United States)

    Sarakovskis, Anatolijs; Krieke, Guna; Doke, Guna; Grube, Jurgis; Grinberga, Liga; Springis, Maris

    2015-01-01

    Complex fluorides, especially rare-earth doped NaREF4 (RE = Y3+, La3+ or Gd3+), are promising materials for the upconversion luminescence mostly due to low phonon energy of their matrices and multisite nature of the crystalline lattice. Although multisite formation in hexagonal NaREF4 structures has generally been proved, the actual number of the active sites in different structures varies from two (NaGdF4) to seven (NaYF4). The aim of this work has been to study multisite formation in NaLaF4:Er3+. For this purpose low-temperature site-selective spectroscopy measurements in hexagonal NaLaF4:Er3+ have been performed. Excitation at different wavelengths corresponding to the excitation of 4F7/2 level of Er3+ ions has revealed three distinct luminescence spectra in the green spectral region associated with 4S3/2 → 4I15/2 electronic transition. The number of the spectra has been sufficient to model experimentally measured luminescence spectra at any excitation wavelength as a linear combination of the distinct spectra. The analysis of the structure of the material and the results of site-selective spectroscopy signify the presence of at least three different crystalline field environments where Er3+ ions incorporate. Upon site-selective excitation of Er3+ located at a specific site energy transfer to erbium ions located at other sites has been observed in both the upconversion and downconversion luminescence processes. The enhanced energy transfer between the different sites in NaLaF4:Er3+ signifies the importance of the multisite nature of the structure, which is a key factor for an efficient upconversion luminescence.

  15. Evaluation of fluoride release from experimental TiF4 and NaF varnishes in vitro

    OpenAIRE

    Livia Picchi COMAR; SOUZA,Beatriz Martines de; Grizzo, Larissa Tercilia; Marília Afonso Rabelo BUZALAF; Magalhães,Ana Carolina

    2014-01-01

    Fluoride varnishes play an important role in the prevention of dental caries, promoting the inhibition of demineralization and the increase of remineralization. Objective: This study aimed to analyze the amount of fluoride released into water and artificial saliva from experimental TiF4 and NaF varnishes, with different concentrations, for 12 h. Material and Methods: Fluoride varnishes were applied on acrylic blocks and then immersed in 10 ml of deionized water and artificial saliva in ...

  16. Emission enhancement through Nd3+-Yb3+ energy transfer in multifunctional NaGdF4 nanocrystals

    Science.gov (United States)

    Pedraza, Francisco J.; Rightsell, Chris; Kumar, G. A.; Giuliani, Jason; Monton, Carlos; Sardar, Dhiraj K.

    2017-05-01

    The growing need for biomedical contrast agents has led to the current development of multi-functional materials such as lanthanide-based nanoparticles (NPs). The optical and magnetic properties these nanoparticles (NPs) possess are important to enhance current biomedical imaging techniques. To increase the optical emissions of the nanoparticles, neodymium (Nd3+) and ytterbium (Yb3+) were introduced into a magnetic host of NaGdF4. The energy transfer between Nd3+ and the Yb3+ was then investigated at multiple concentrations to determine the optimal dopant levels. The NaGdF4:Nd3+,Yb3+ nanoparticles were synthesized through a modified solvothermal method, resulting in rectangular structures, with an average side length of 17.87 ± 4.38 nm. A double dopant concentration of 10% Nd3+ and 4% Yb3+ was found to be optimal, increasing the emission intensity by 71.5% when compared to the widely used Nd3+ single dopant. Decay measurements confirm energy transfer from Nd3+ to Yb3+, with a lifetime shortening from Nd3+ 1064 nm emission and a calculated lifetime of 12.72 ms with 98% efficiency. Despite NaGdF4:Nd3+,Yb3+ NPs showing a slight decrease in their magnetic response at the expense of optimizing optical emission, as it is directly dependent on the Gd3+ concentration, a strong paramagnetic behavior was still observed. These results corroborate that NaGdF4:Nd3+,Yb3+ NPs are viable candidates for multimodal imaging.

  17. Characterization of transgene integration pattern in F4 hGH-transgenic common carp (Cyprinus carpio L.)

    Institute of Scientific and Technical Information of China (English)

    Bo WU; Yong Hua SUN; Yan Wu WANG; Ya Ping WANG; Zuo Yan ZHU

    2005-01-01

    The integration pattern and adjacent host sequences of the inserted pMThGH-transgene in the F4 hGH-transgenic common carp were extensively studied. Here we show that each F4 transgenic fish contained about 200 copies of the pMThGH-transgene and the transgenes were integrated into the host genome generally with concatemers in a head-totail arrangement at 4-5 insertion sites. By using a method of plasmid rescue, four hundred copies of transgenes from two individuals of F4 transgenic fish, A and B, were recovered and clarified into 6 classes. All classes of recovered transgenes contained either complete or partial pMThGH sequences. The class Ⅰ, which comprised 83% and 84.5% respectively of the recovered transgene copies from fish A and B, had maintained the original configuration, indicating that most transgenes were faithfully inherited during the four generations of reproduction. The other five classes were different from the original configuration in both molecular weight and restriction map, indicating that a few transgenes had undergone mutation, rearrangement or deletion during integration and germline transmission. In the five types of aberrant transgenes, three flanking sequences of the host genome were analyzed. These sequences were common carp β-actin gene, common carp DNA sequences homologous to mouse phosphoglycerate kinase-1 and human epidermal keratin 14, respectively.

  18. Linkage and comparative mapping of the locus controlling susceptibility towards E. COLI F4ab/ac diarrhoea in pigs.

    Science.gov (United States)

    Jørgensen, C B; Cirera, S; Anderson, S I; Archibald, A L; Raudsepp, T; Chowdhary, B; Edfors-Lilja, I; Andersson, L; Fredholm, M

    2003-01-01

    In 1995, Edfors-Lilja and coworkers mapped the locus for the E. COLI K88ab (F4ab) and K88ac (F4ac) intestinal receptor to pig chromosome 13 (SSC13). Using the same family material we have refined the map position to a region between the microsatellite markers Sw207 and Sw225. Primers from these markers were used to screen a pig BAC library and the positive clones were used for fluorescent in situ hybridization (FISH) analysis. The results of the FISH analysis helped to propose a candidate gene region in the SSC13q41-->q44 interval. Shotgun sequencing of the FISH-mapped BAC clones revealed that the candidate region contains an evolutionary breakpoint between human and pig. In order to further characterise the rearrangements between SSC13 and human chromosome 3 (HSA3), detailed gene mapping of SSC13 was carried out. Based on this mapping data we have constructed a detailed comparative map between SSC13 and HSA3. Two candidate regions on human chromosome 3 have been identified that are likely to harbour the human homologue of the gene responsible for susceptibility towards E. COLI F4ab/ac diarrhoea in pigs.

  19. Crystal phase transition in LixNa1-xGdF4 solid solution nanocrystals - Tuning of optical properties

    KAUST Repository

    Bański, Mateusz

    2014-01-01

    The influence of precursor composition on the crystallization of LixNa1-xGdF4 is investigated and discussed. Nanocrystals are prepared from the thermal decomposition of trifluoroacetates in the presence of trioctylphosphine oxide to provide control over particle size. A crystal phase transition from hexagonal to cubic and to tetragonal is observed by increasing lithium trifluoroacetate (Li-TFA) in the solution. Controlling the composition of LixNa1-xGdF4 nanocrystals results in modified crystal field symmetry and emission properties from doped europium (Eu3+) ions. We report that for lithium (Li+) substitution <15%, the hexagonal crystal field is preferred, while the Eu3+ emission is already tuned, whereas at higher Li+ substitution, a phase change takes place and the number of crystalline matrix defects increases which is reflected in the optical properties of Eu3+. From Eu3+ emission properties, the optimum Li+ content is determined to be ∼6.2% in the prepared LixNa1-xGdF4 nanocrystals.

  20. Based on load balancing F5 application delivery networking technology in cadres onlineplatform%基于F5负载均衡应用交付网络技术在干部在线的应用

    Institute of Scientific and Technical Information of China (English)

    马维

    2016-01-01

    应用交付网络技术的理念就是把网络及应用深度结合在一起。安全、快速、高可用是应用交付网络的三大要素。应用交付网络技术由服务器负载均衡、链路负载均衡、应用安全管理、应用加速等多种技术组成。目的是提高用户体验,保证网络安全的前提下解决用户关键网络应用访问瓶颈的问题。根据干部在线学习平台遇到的随机大流量、高并发、及网络安全等问题,我们就需要引入应用交付网络技术。F5是当今业界首推的一款应用交付网络控制器。本文在介绍应用交付网络技术的基础上,把F5的功能和应用交付技术相关知识融合在一起,并且实际地应用到干部在线平台网络架构。解决了平台在线人数阶梯式增长所带来的问题。让在线学习平台更加安全、高效、灵活、有序的运转。%Application delivery network technology is the concept of the network and application depth together.Safe,rapid, high availability is the three elements of application delivery network. Application delivery network technology by the server load balancing,link load balancing,the application of safety management,use of a variety of techniques such as acceleration.The purpose is to improve the user experience,to guarantee the network security under the premise of solving the user key network application access bottleneck problem.Cadres according to the online learning platform of large flow, high concurrency,and the problem of network security,we need to introduce the application delivery network technology.F5 is today one of the first industry an application delivery network controller.This paper introduces the application delivery,on the basis of network technology,the function and application of the F5 delivery technology related knowledge together, and practically applied to the cadres online platform network architecture.To solve the platform online step growth brought

  1. Formation of diphenylphosphanylbutadienyl complexes by insertion of two P-coordinated alkynylphosphanes into a PtbondC6F5 bond: detection of intermediate and reaction products.

    Science.gov (United States)

    Ara, Irene; Forniés, Juan; García, Ana; Gómez, Julio; Lalinde, Elena; Moreno, M Teresa

    2002-08-16

    The reactions between cis-[M(C(6)F(5))(2)(PPh(2)CtriplebondCR)(2)] (M=Pt, Pd; R=Ph, tBu, Tol 2, 3) or cis-[Pt(C(6)F(5))(2)(PPh(2)CtriplebondCR)(PPh(2)CtriplebondCtBu)] (R=Ph 4, Tol 5) and cis-[Pt(C(6)F(5))(2)(thf)(2)] 1 have been investigated. Whereas [M](PPh(2)CtriplebondCtBu)(2) ([M]=cis-M(C(6)F(5))(2)) is inert towards 1, the analogous reactions starting from [M](PPh(2)CtriplebondCR)(2) or [Pt](PPh(2)CtriplebondCR)(PPh(2)CtriplebondCtBu) (R=Ph, Tol) afford unusual binuclear species [Pt(C(6)F(5))(S)mu-[C(R')dbondC(PPh(2))C(PPh(2))doublebondC(R)(C(6)F(5))]M(C(6)F(5))(2)] (R=R'=Ph, Tol, M=Pt 6 a,c, M=Pd 7 a,c; M=Pt, R'=tBu, R=Ph 8, Tol 9) containing a bis(diphenylphosphanyl)butadienyl bridging ligand formed by an unprecedented sequential insertion reaction of two P-coordinated PPh(2)CtriplebondCR ligands into a PtbondC(6)F(5) bond. Although in solution the presence of coordinated solvent S (S=(thf)(x)(H(2)O)(y)) in 6, 7 is suggested by NMR spectroscopy, X-ray diffraction analyses of different crystals of the mixed complex [Pt(C(6)F(5))mu-[C(tBu)doublebondC(PPh(2))C(PPh(2))doublebondC(Tol)(C(6)F(5))]Pt(C(6)F(5))(2)] 9 unequivocally establish that in the solid state the steric crowding of the new diphenylbutadienyl ligand formed stabilizes an unusual coordinatively unsaturated T-shaped 3-coordinated platinum(II) center. Structure determinations of the mononuclear precursors cis-[Pt(C(6)F(5))(2)(PPh(2)CtriplebondCR)(2)] (R=Ph, tBu, Tol) have been carried out to evaluate the factors affecting the insertion processes. The reactions of the platinum complexes 6 towards neutral ligands (L=CO, py, PPh(2)H, CNtBu) in a 1:1 molar ratio afford related diplatinum derivatives 10-13, whereas treatment with CNtBu (1:2 molar ratio) or 2,2'-bipy (1:1 molar ratio) results in the opening of the chelating ring to give cis,cis-[Pt(C(6)F(5))(L)(2)mu-[1-kappaC(1):2-kappaPP'-C(R)doublebondC(PPh(2))C(PPh(2))doublebondC(R)(C(6)F(5))]Pt(C(6)F(5))(2)] (14, 15). The unsaturated or solvento

  2. Investigation on reactivity of non-classical carbenes with sterically hindered Lewis acid, B(C6F5)3 under inert and open conditions

    Indian Academy of Sciences (India)

    Arunabha Thakur; Pavan K Vardhanapu; Gonela Vijaykumar; Sushil Ranjan Bhatta

    2016-04-01

    Reactions of B(C6F5)3 with abnormal N-heterocyclic carbene (NHC), L1 and cyclic (alkyl)(amino) carbene (AAC), L2 in the presence of moisture as well as in its absence, have been investigated in toluene. Reaction of NHC with 1 equivalent of B(C6F5)3 under inert condition produced classical Lewis acid-base adduct, [L1.B(C6F5)3], 1. Further, probing the same reaction with cyclic (alkyl)(amino) carbene (AAC), having different electronic property, led to the isolation of [L2.B(C6F5)3], 2 under inert condition. Interestingly, reaction of NHC or AAC with 1 equivalent of B(C6F5)3 in the presence of moisture resulted in water splitting leading to the formation of [L1-H][(OH)B(C6F5)3], 3 and [L2-H][(OH)B(C6F5)3, 4. All these compounds (1-4) were characterized in solution by 1H, 13C, 19F and 11B NMR spectroscopy. Additionally, the solid-state structures were unambiguously established by crystallographic analysis of compounds 1-4.

  3. Europium-phenolic network coated BaGdF5 nanocomposites for tri-modal computed tomography/magnetic resonance/luminescence imaging.

    Science.gov (United States)

    Zhu, Wei; Liang, Shuang; Wang, Jing; Yang, Zhe; Zhang, Li; Yuan, Tianmeng; Xu, Zushun; Xu, Haibo; Li, Penghui

    2017-05-01

    Multifunctional nanocomposites based on BaGdF5 nanoparticles (NPs) and metal phenolic network (MPN) have been engineered as novel contrast agents for potential applications in X-ray computed tomography, magnetic resonance and luminescence imaging. The BaGdF5@MPN nanocomposites were synthesized at room temperature by coating BaGdF5 NPs with europium-phenolic network, which was obtained by the coordination of europium (III) with tannic acid (TA). The in vitro cytotoxicity assays against HepG2 cells revealed that the BaGdF5@MPN nanocomposites presented better cytocompatibility and lower cytotoxity than pure BaGdF5 NPs. In addition, vivid red and green luminescence can be observed by confocal laser scanning microscope (CLSM) from the BaGdF5@MPN nanocomposites laden HepG2 cells under the excitation of UV (390 nm) and visible light (440 nm), respectively. The longitudinal relaxivity value (r1) of the nanocomposites was 2.457 mM(-1)s(-1). Moreover, the nanocomoposites exhibited X-ray computed tomography (CT) and T1-weighted magnetic resonance (MR) imaging capacities, and the intensities of the enhanced signals of in vitro CT and MR images were proportional to the concentrations of the nanocomposites. These results indicated that the as-prepared BaGdF5@MPN nanocomposites are promising contrast agents for CT/MR/luminescence imaging.

  4. Separative recovery with lime of phosphate and fluoride from an acidic effluent containing H3PO4, HF and/or H2SiF6.

    Science.gov (United States)

    Gouider, Mbarka; Feki, Mongi; Sayadi, Sami

    2009-10-30

    Fluoride content and flow-rate of fertilizer plant wastewater from phosphoric acid and/or triple superphosphate (TSP) production lead to the discharge of several thousand tons of fluoride (F(-)) per year and even more for phosphate (PO4(3-)). Since sustainability is an important environmental concern, the removal methods should allow phosphorus and fluoride to be recycled as a sustainable products for use as raw materials either in agricultural or industrial applications. In the present work, separative recovery with lime of these two target species was investigated. A preliminary speciation study, carried out on the crude effluent, showed that two forms of fluoride: HF and H2SiF6 are present in a highly acidic medium (pH approximately 2). Evidence that fluoride is present under both free (HF) and combined (H2SiF6) forms, in the phosphate-containing effluent, was provided by comparing potentiometric titration curves of a crude wastewater sample and synthetic acid mixtures containing H3PO4, HF and H2SiF6. In a second step synthetic effluent containing mixtures of the following acids: HF, H2SiF6 and H3PO4, were treated with lime. The behaviour of these compounds under lime treatment was analysed. The data showed that fluoride has a beneficial effect on phosphate removal. Moreover, by acting on the precipitation pH, a "selective" recovery of fluoride and phosphate ions was possible either from phosphoric acid/hydrofluoric acid or phosphoric acid/hexafluorosilicic acid mixtures. Indeed, the first stage of the separative recovery, led to a fluoride removal efficiency of 97-98% from phosphoric acid/hydrofluoric acid mixture. It was of 93-95% from phosphoric acid/hexafluorosilicic acid mixture. During the second stage, the phosphate precipitation reached 99.8% from both acidic mixtures whereas it did not exceed 82% from a solution containing H3PO4 alone. The XRD and IR analyses showed that during lime treatment, a H2SiF6 hydrolysis occurred, instead of CaSiF6 solid

  5. Method of (SiF3) 2 O Purification from SiF4 Gas%SiF4气体中(SiF3)2O的净化方法

    Institute of Scientific and Technical Information of China (English)

    韦德举; 唐安江; 张妙鹤; 马翠翠

    2014-01-01

    Silicon tetrafluoride is an important raw material in electronic industry .It can also be used as raw material of optical fiber.solar cell and cement hardener.The generation principle of ( SiF3 ) 2 O from SiF4 gas are detailed described.The purification method of ( SiF3 ) 2 O mainly have activated carbon adsorption method.And with concentrated sulfuric acid containing hydrogen fluoride , fluorine gas and fluorinating agent reaction , The details of the purification effect of activated carbon on the four silicon fluoride impurities in gas.%高纯度四氟化硅( SiF4)是电子工业中的一种重要原料,能用于光导纤维、太阳能电池和水泥硬化剂等的原料。详细介绍了SiF4气体中( SiF3)2 O的生成原理和( SiF3)2 O的净化方法,六氟二甲硅醚的纯化方法有活性炭吸附法,与含氟化氢的浓硫酸,氟气,氟化剂等物质发生反应,其中详细介绍了活性炭对四氟化硅气体中的杂质的净化效果。

  6. B(C6F5)3: A Lewis Acid that Brings the Light to the Solid State.

    Science.gov (United States)

    Hansmann, Max M; López-Andarias, Alicia; Rettenmeier, Eva; Egler-Lucas, Carolina; Rominger, Frank; Hashmi, A Stephen K; Romero-Nieto, Carlos

    2016-01-18

    The straightforward coordination of the Lewis acid B(C6F5)3 to classical, non-emitting aldehydes results in solid-state photoluminescence. Variation of the electronic properties of the carbonyl moieties lead to the modulation of the solid-state emission colors, covering the entire visible spectrum with quantum yields up to 0.64. Steady-state spectroscopy in combination with X-ray diffraction analysis and DFT calculations confirm that intermolecular interactions between the Lewis adducts are responsible for the observed luminescence. Alteration of the latter interactions induces, moreover, remarkable solid-state phenomena such as piezochromism. The versatility and simplicity of our approach facilitate the future development of solid-state emitting materials.

  7. Tm∶YLiF4激光晶体的生长及性能研究%Growth and Spectral Properties of Tm:YLiF4 Crystals

    Institute of Scientific and Technical Information of China (English)

    陈光珠; 杭寅; 彭海燕; 张连翰; 尹继刚; 熊婧; 何晓明; 徐剑秋

    2011-01-01

    High optical quality 2% number fraction of thulium replacemented yttrium atoms Tm:YLiF4 (YLF) crystal is successfully grown by the Czochralski technique with the medium frequency induction heating furnace. The structure of Tm:YLF crystal is determined by the precise X ray diffraction (XRD) measurement. And the spectral properties of Tm:YLF crystal are studied and analyzed by absorption and fluorescence spectra. Absorption coefficient and absorption section of Tm ion at different wavelengths are calculated. At room temperature, Tm: YLFstabs made by 2% thulium-doped single crystal are end-pumped by a laser diode stack at wavelength of 793 nm. Laser output of 54.4 W continuous wave power at 160 W input power is achieved, corresponding to an optical efficiency of 31.2 %.%选择中频电磁感应加热提拉法生长出了透明、基本无散射和气泡、无包裹物的高质量的铥(Tm)取代钇(Y)的原子数分数为2%的Tm∶YLiF4(YLF),并采用X射线衍射(XRD)法对晶体进行了物相分析.测试Tm∶YLF晶体的吸收光谱并计算了Tm离子对不同波长的吸收系数和吸收截面.同时测定其荧光光谱并分析了3H4-3F4和3F4-3H6跃迁产生的发射峰.对Tm:YLF晶体进行了激光实验,当输入功率为160 W时,获得了54.4 W的激光输出,斜率效率为35.6%,最大光光转换效率为31.2%.

  8. Synthesis of Structurally Diverse 2,3-Fused Indoles via Microwave-Assisted AgSbF6-Catalysed Intramolecular Difunctionalization of o-Alkynylanilines

    Science.gov (United States)

    Huang, Yuanqiong; Yang, Yan; Song, Hongjian; Liu, Yuxiu; Wang, Qingmin

    2015-08-01

    2,3-Fused indoles are found in numerous natural products and drug molecules. Although several elegant methods for the synthesis of this structural motif have been reported, long reaction times and harsh conditions are sometimes required, and the yields tend to be low. Herein, we report a microwave method for straightforward access to various types of 2,3-fused indoles via AgSbF6-catalysed intramolecular difunctionalization of o-alkynylanilines. AgSbF6 played a role in both the hydroamination step and the imine-formation step. This method, which exhibited excellent chemoselectivity (no ring-fused 1,2-dihydroquinolines were formed), was used for formal syntheses of the natural products conolidine and ervaticine and the antihistamine drug latrepirdine.

  9. s-wave threshold in electron attachment - Results in 2-C4F6 and CFCl3 at ultra-low electron energies

    Science.gov (United States)

    Chutjian, A.; Alajajian, S. H.; Ajello, J. M.; Orient, O. J.

    1984-01-01

    Electron attachment lineshapes and cross sections are reported for the processes 2-C4F6(-)/2-C4F6 and Cl(-)/CFCl3 at electron energies of 0-120 and 0-140 meV, and at resolutions of 6 and 7 meV (FWHM), respectively. As in previous measurements in CCl4 and SF6, the results show resolution-limited narrow structure in the cross section at electron energies below 15 meV. This structure arises from the divergence of the s-wave cross section in the limit of zero electron energy. Comparisons are given with swarm-measured results, and with collisional ionization (high-Rydberg attachment) data in this energy range.

  10. Influence of [Mo6Br8F6]2- cluster unit inclusion within the mesoporous solid MIL-101 on hydrogen storage performance.

    Science.gov (United States)

    Dybtsev, Danil; Serre, Christian; Schmitz, Barbara; Panella, Barbara; Hirscher, Michael; Latroche, Michel; Llewellyn, Philip L; Cordier, Stéphane; Molard, Yann; Haouas, Mohamed; Taulelle, Francis; Férey, Gérard

    2010-07-06

    The inclusion of (TBA)(2)Mo(6)Br(8)F(6) (TBA = tetrabutylammonium) containing [Mo(6)Br(8)F(6)](2-) cluster units within the pores of the mesoporous chromium carboxylate MIL-101 (MIL stand for Materials from Institut Lavoisier) has been studied. X-ray powder diffraction, thermal analysis, elemental analysis, solid-state NMR, and infrared spectroscopy have evidenced the successful loading of the cluster. In a second step, the hydrogen sorption properties of the model cluster loaded metal organic framework (MOF) system have been analyzed and compared to those of the pure MOF sample, through a combination of adsorption isotherms (77 K, room temperature), thermal desorption spectroscopy, and calorimetry (calculated and experimental) in order to evaluate the hydrogen storage efficiency of the cluster loading.

  11. Hyperfine structure constants and isotope shift of the levels of the configuration 4 f 6 5 d 6 s 2 in Eu I

    Science.gov (United States)

    Elantkowska, M.; Bernard, A.; Dembczyński, J.; Ruczkowski, J.

    1993-06-01

    The hyperfine structure (hfs) and the isotope shift (IS) of transitions between metastable levels of the configuration 4 f 7 5 d 6 s and levels of the configuration 4 f 6 5 d 6 s 2 of151Eu and153Eu were studied by means of the high resolution laser-atomic-beam technique. New data for the hfs in151Eu and153Eu were obtained as well as new and more accurate for the IS between151Eu and153Eu. The measured hfs constants A and B of the 4 f 6 5 d 6 s 2 configuration allow to perform a parametric analysis using the Sandars and Beck theory. The value of the Sternheimer correction is also disscused.

  12. Ischemic stroke in Ukrainian population: possible involvement of the F2 G20210A, F5 G1691A and MTHFR C677T gene variants

    Directory of Open Access Journals (Sweden)

    Kuznetsova S. M.

    2010-07-01

    Full Text Available Aim. To evaluate a possible involvement of the F2, F5, MTHFR gene variants into ischemic stroke pathogenesis in population of Ukraine. Methods. Polymorphic variants were analyzed in unrelated 183 stroke patients, 100 individuals from the general population of Ukraine and 88 healthy individuals elder than 65 years using PCR followed by RFLP analysis. Results. Unfavourable polymorphic variants F2 20210A, F5 1691A and MTHFR 677T were observed more frequently in patients with ischemic stroke comparing to control groups. Conclusions. F5 1691A and MTHFR 677T polymorphic variants are associated with the occurrence of ischemic stroke in women. F2 20210A is associated with the occurrence of ischemic stroke in men. Cumulative risk factor for stroke development is revealed in a combination of unfavorable polymorphic variants 20210A, 1691A and 677T of F2, F5 and MTHFR genes.

  13. Isotopic ratios of H, C, N, O, and S in comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy)

    OpenAIRE

    Biver, N; Moreno, R.; Bockelée-Morvan, D.; Sandqvist, Aa.; Colom, P.; Crovisier, J.; Lis, D.C.; Boissier, J.; Debout, V; Paubert, G.; Milam, S.; Hjalmarson, A.; Lundin, S; T. Karlsson; Battelino, M.

    2016-01-01

    The apparition of bright comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy) in March-April 2013 and January 2015, combined with the improved observational capabilities of submillimeter facilities, offered an opportunity to carry out sensitive compositional and isotopic studies of the volatiles in their coma. We observed comet Lovejoy with the IRAM 30m telescope between 13 and 26 January 2015, and with the Odin submillimeter space observatory on 29 January - 3 February 2015. We detected 22 mole...

  14. Highly stable ni-m f6-nh2o/onpyrazine2(solvent)x metal organic frameworks and methods of use

    KAUST Repository

    Eddaoudi, Mohamed

    2016-10-13

    Provided herein are metal organic frameworks comprising metal nodes and N-donor organic ligands. Methods for capturing chemical species from fluid compositions comprise contacting a metal organic framework characterized by the formula [MaMbF6-n(O/H2O)w(Ligand)x(solvent)y]z with a fluid composition and capturing one or more chemical species from the fluid composition.

  15. Volcanic SO2 and SiF4 visualization and their ratio monitored using 2-D thermal emission spectroscopy

    Science.gov (United States)

    Stremme, W.; Krueger, A.; Harig, R.; Grutter, M.

    2011-09-01

    The composition and emission rates of volcanic gas plumes provide insight of the geologic internal activity, atmospheric chemistry, aerosol formation and radiative processes around it. Observations are necessary for public security and the aviation industry. Ground-based thermal emission infrared spectroscopy, which uses the radiation of the volcanic gas itself, allows for continuously monitoring during day and night from a save distance. We present measurements on Popocatépetl volcano based on thermal emission spectroscopy during different campaigns between 2006-2009 using a Scanning Infrared Gas Imaging System (SIGIS). The experimental set-up, measurement geometries and analytical algorithms are described. The equipment was operated from a safe distance of 12 km from the volcano at two different spectral resolutions: 0.5 and 4 cm-1. The 2-dimensional scanning capability of the instrument allows for an on-line visualization of the volcanic SO2 plume, animation and determination of its propagation speed. SiF4 was also identified in the infrared spectra recorded at both resolutions. The SiF4/SO2 molecular ratio can be calculated from each image and used as a highly useful parameter to follow changes in volcanic activity. A small Vulcanian eruption was monitored during the night of 16 to 17 November 2008 which was confirmed from the strong ash emission registered around 01:00 a.m. LST (Local Standard Time) and a pronounced SO2 cloud was registered. Enhanced SiF4/SO2 ratios were observed before and after the eruption. A validation of the results from thermal emission measurements with those from absorption spectra of the moon taken at the same time, as well as an error analysis, are presented. The inferred propagation speed from sequential imagees is used to calculate the emission rates at different distances from the crater.

  16. Structure-guided alterations of the gp41-directed HIV-1 broadly neutralizing antibody 2F5 reveal new properties regarding its neutralizing function.

    Directory of Open Access Journals (Sweden)

    Javier Guenaga

    Full Text Available The broadly neutralizing HIV-1 antibody 2F5 recognizes an epitope in the gp41 membrane proximal external region (MPER. The MPER adopts a helical conformation as free peptide, as post-fusogenic forms of gp41, and when bound to the 4E10 monoclonal antibody (Mab. However, when bound to 2F5, the epitope is an extended-loop. The antibody-peptide structure reveals binding between the heavy and light chains with most the long, hydrophobic CDRH3 not contacting peptide. However, mutagenesis identifies this loop as critical for binding, neutralization and for putative hydrophobic membrane interactions. Here, we examined length requirements of the 2F5 CDRH3 and plasticity regarding binding and neutralization. We generated 2F5 variants possessing either longer or shorter CDRH3s and assessed function. The CDRH3 tolerated elongations and reductions up to four residues, displaying a range of binding affinities and retaining some neutralizing capacity. 2F5 antibody variants selective recognition of conformationally distinctive MPER probes suggests a new role for the CDRH3 loop in destabilizing the helical MPER. Binding and neutralization were enhanced by targeted tryptophan substitutions recapitulating fully the activities of the wild-type 2F5 antibody in a shorter CDRH3 variant. MPER alanine scanning revealed binding contacts of this variant downstream of the 2F5 core epitope, into the 4E10 epitope region. This variant displayed increased reactivity to cardiolipin-beta-2-glycoprotein. Tyrosine replacements maintained neutralization while eliminating cardiolipin-beta-2-glycoprotein interaction. The data suggest a new mechanism of action, important for vaccine design, in which the 2F5 CDRH3 contacts and destabilizes the MPER helix downstream of its core epitope to allow induction of the extended-loop conformation.

  17. Water Production in Comets C/2011 l4 (PanSTARRS) and C/2012 f6 (Lemmon) from observations with SOHO/SWAN

    Science.gov (United States)

    Combi, M. R.; Bertaux, J.-L.; Quémerais, E.; Ferron, S.; Mäkinen, J. T. T.; Aptekar, G.

    2014-06-01

    Comets C/2011 L4 (PanSTARRS) and C/2012 F6 (Lemmon) were observed throughout their 2012-2013 apparitions with the Solar Wind Anisotropies (SWAN) all-sky hydrogen Lyα camera on board the Solar and Heliosphere Observatory (SOHO) satellite. SOHO has been in a halo orbit around the L1 Earth-Sun Lagrange point since early 1996 and has been observing the interplanetary medium and comets beginning with C/1996 B2 (Hyakutake). The global water production from these comets was determined from an analysis of the SWAN Lyα camera observations. Comet C/2011 L4 (PanSTARRS), which reached its perihelion distance of 0.302 AU on 2013 March 10.17, was observed on 50 days between 2013 January 29 and April 30. Comet C/2012 F6 (Lemmon), which reached its perihelion distance of 0.731 AU on 2013 March 24.51, was observed on 109 days between 2012 November 29 and 2013 June 31. The maximum water production rates were ~1 × 1030 molecules s-1 for both comets. The activities of both comets were asymmetric about perihelion. C/2011 L4 (PanSTARRS) was more active before perihelion than after, but C/2012 F6 (Lemmon) was more active after perihelion than before.

  18. NaLaF4:Pr3+,Yb3+, an efficient blue to near infra-red quantum cutter

    Directory of Open Access Journals (Sweden)

    A. Guille

    2013-12-01

    Full Text Available In order to reduce the thermalization losses in solar cells, down-conversion of blue photons into near infra-red photons is a promising solution. In the present paper, we analyse the energy transfer processes between Pr3+ and Yb3+ in NaLaF4 and we show that an efficient quantum-cutting process occurs. Nevertheless, we also show that a back transfer from Yb3+ toward the 1G4 level of Pr3+ ion leading to emission beyond 1 μm reduces the potentiality of this material as a quantum cutter for Si solar cells.

  19. Efficient Ho:LuLiF4 laser diode-pumped at 1.15 μm.

    Science.gov (United States)

    Wang, Sheng-Li; Huang, Chong-Yuan; Zhao, Cheng-Chun; Li, Hong-Qiang; Tang, Yu-Long; Yang, Nan; Zhang, Shuai-Yi; Hang, Yin; Xu, Jian-Qiu

    2013-07-15

    We report the first laser operation based on Ho(3+)-doped LuLiF(4) single crystal, which is directly pumped with 1.15-μm laser diode (LD). Based on the numerical model, it is found that the "two-for-one" effect induced by the cross-relaxation plays an important role for the laser efficiency. The maximum continuous wave (CW) output power of 1.4 W is produced with a beam propagation factor of M(2) ~2 at the lasing wavelength of 2.066 μm. The slope efficiency of 29% with respect to absorbed power is obtained.

  20. Two-step photoconductivity in LiY x Lu1 - x F4:Ce,Yb crystals

    Science.gov (United States)

    Nurtdinova, L. A.; Korableva, S. L.; Leontiev, A. V.

    2016-10-01

    Photoconductivity of LiY x Lu1- x F4:Ce,Yb ( x = 0-1) crystals is measured under one- and two-step excitation. It is established that the photoconductivity is due to intra-center transitions from excited states of Ce3+ ions. The position of the ground 4 f-state of Ce3+ ion relative to the bottom of the conduction band is determined. The choice of pumping conditions to obtain the lasing on the 5 d-4 f transitions of trivalent cerium in these active media is substantiated.

  1. Study of electronic structures and absorption bands of BaMgF4 crystal with F colour centre

    Institute of Scientific and Technical Information of China (English)

    Kang Ling-Ling; Liu Ting-Yu; Zhang Qi-Ren; Xu Ling-Zhi; Zhang Fei-Wu

    2011-01-01

    The electronic structures of BaMgF4 crystals containing an F colour centre are studied within the framework of the fully relativistic self-consistent Direc-Slate-theory, using a numerically discrete variational (DV-Xα)method. It is concluded from the calculated results that the energy levels of the F colour centre are located in the forbidden band.The optical transition energy from the ground state to the excited state for the F colour centre is about 5.12 eV, which corresponds to the 242-nm absorption band. These calculated results can explain the origin of the absorption bands.

  2. Crystal structure and physical properties of Cr oxide with K2NiF4-type structure

    Science.gov (United States)

    Kao, Ting-Hui; Sakurai, Hiroya; Kolodiazhnyi, Taras; Suzuki, Yutaro; Okabe, Momoko; Asaka, Toru; Fukuda, Koichiro; Okubo, Susumu; Ikeda, Shohei; Hara, Shigeo; Sakurai, Takahiro; Ohta, Hitoshi; Yang, Hung-Duen; National Sun-Yet Sen University Team; National InstituteMaterials Science Team; Nagoya Institute of Technology Collaboration; Kobe University Collaboration

    2015-03-01

    Ruddlesden-Popper (RP) type structure materials have been attracted much attention due to their interesting physical properties including high-Tc superconductivity, charge stripe, itinerant ferromagnetism and so on. In this work we are presenting physical properties of some of the K2NiF4 type structure compounds. YSrCrO4 is first synthesized and found to be a hetto-type K2NiF4 structure. The space group of YSrCrO4 is determined to be orthorhombic Pccn by the electron diffraction and the powder X-ray diffraction. YSrCrO4 shows two-dimensional (2D) spin correlations and a canted antiferromagnetic (AF) ordering. Evidence of AF ordering of the Cr oxides is obtained microscopically from ESR. The dielectric measurements suggest existence of in-gap states, while no magneto-dielectric coupling was observed in the above compounds. National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.

  3. Transparent NaGdF4:Nd3+ colloid prepared by femtosecond laser ablation as a liquid laser medium

    Science.gov (United States)

    Dai, Jiangyun; Feng, Guoying; Wang, Shutong; Zhang, Hong; Dai, Shengyu; Zhou, Shouhuan

    2017-07-01

    By using femtosecond-pulsed laser to ablate the larger nanosized target in liquid, stable transparent NaGdF4:Nd3+ colloid has been successfully fabricated. The X-ray diffraction (XRD) spectra reveal that the colloidal nanoparticles remain the hexagonal phase crystal structure of NaGdF4 powder target. SEM and TEM images results indicate that the size of these colloidal nanoparticles decreases sharply. FT-IR results indicate that the number of O-H and C-H groups on the surface is decreased. The emission properties of the colloid have been investigated using 794 nm pulsed wave laser radiation, and it is found that the colloid exhibits near-infrared luminescent emissions in the spectral range of 850-1400 nm, and the decay time for 4F3/2→4I11/2 (1058 nm) Nd3+ ion transitions is lengthened than that of powder target, these results are probably due to the reduced nonradiative relaxation assisted by high energy oscillators. The observed near-infrared emission of the stable transparent colloid makes it a good candidate for application in liquid laser.

  4. Transgenes in F4 pMThGH- transgenic common carp (Cy- prinus carpio L.) are highly polymorphic

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To gain information on the integration pattern of pMThGH-tansgene, 50 transgenes were recovered from F4 generation of pMThGH transgenic common carp (Cyprinus carpio L.) and 33 recovered genes were analyzed. The restriction maps of these recovered genes were constructed by digestion with five kinds of enzymes. These transgenes can be classified into 4 types according to their restriction maps. Only one type of transgenes maintains its original molecular form, whereas the other three types are very different from the original one and vary each other on both molecular weight and restriction maps. This implies that the sequences of most transgenes have been deleted and/or rearranged during integration and inheritance. The results of PCR am-plification and Southern blot hybridization indicate that MThGH in TypeI transgene keeps intact but most of its se-quence has been deleted in other three types. All these results suggest that transgenes in F4 generation of transgenic carp are highly polymorphic. Two DNA fragments concerning integration site of transgenes were cloned from recovered transgenes, and found to be homologous to the 5′UTR of β-actin gene of common carp and mouse mRNA for receptor tyrosine kinase (RTK), respectively.

  5. Cytotoxicity, tumor targeting and PET imaging of sub-5 nm KGdF4 multifunctional rare earth nanoparticles

    Science.gov (United States)

    Cao, Xinmin; Cao, Fengwen; Xiong, Liqin; Yang, Yang; Cao, Tianye; Cai, Xi; Hai, Wangxi; Li, Biao; Guo, Yixiao; Zhang, Yimin; Li, Fuyou

    2015-08-01

    Ultrasmall sub-5 nm KGdF4 rare earth nanoparticles were synthesized as multifunctional probes for fluorescent, magnetic, and radionuclide imaging. The cytotoxicity of these nanoparticles in human glioblastoma U87MG and human non-small cell lung carcinoma H1299 cells was evaluated, and their application for in vitro and in vivo tumor targeted imaging has also been demonstrated.Ultrasmall sub-5 nm KGdF4 rare earth nanoparticles were synthesized as multifunctional probes for fluorescent, magnetic, and radionuclide imaging. The cytotoxicity of these nanoparticles in human glioblastoma U87MG and human non-small cell lung carcinoma H1299 cells was evaluated, and their application for in vitro and in vivo tumor targeted imaging has also been demonstrated. Electronic supplementary information (ESI) available: Details of the experimental section as well as EDXA, XRD, zeta potential, FTIR, TGA, stability, TEM, Z scanning, ICP-MS, and MicroPET/CT images. See DOI: 10.1039/c5nr03374h

  6. The sex-linked fidget mutation abolishes Brn4/Pou3f4 gene expression in the embryonic inner ear.

    Science.gov (United States)

    Phippard, D; Boyd, Y; Reed, V; Fisher, G; Masson, W K; Evans, E P; Saunders, J C; Crenshaw, E B

    2000-01-01

    We have demonstrated that the phenotype of the mouse mutant sex-linked fidget ( slf ) is caused by developmental malformations of the inner ear that result in hearing loss and vestibular dysfunction. Recently, pilot mapping experiments suggested that the mouse Brn4 / Pou3f4 gene co-segregated with the slf locus on the mouse X chromosome. These mapping data, in conjunction with the observation that the vertical head-shaking phenotype of slf mutants is identical to that observed in mice with a targeted deletion of the Brn4 gene, suggested that slf is a mutant allele of the Brn4 gene. In this paper, we have identified the nature of the slf mutation, and demonstrated that it is an X chromosomal inversion with one breakpoint close to Brn4. This inversion selectively eliminates the expression of the Brn4 gene in the developing inner ear, but not the neural tube. Finally, these results demonstrate that the slf mutation is a good mouse model for the most prevalent form of X-linked congenital deafness in man, which is associated with mutations in the human Brn4 ortholog, POU3F4.

  7. Zoom-climb altitude maximization of the F-4C and F-15 aircraft for stratospheric sampling missions

    Science.gov (United States)

    Hague, D. S.; Merz, A. W.; Page, W. A.

    1976-01-01

    Some predictions indicate that byproducts of aerosol containers may lead to a modification of the ultraviolet-radiation shielding properties of the upper atmosphere. NASA currently monitors atmospheric properties to 70,000 feet using U-2 aircraft. Testing is needed at about 100,000 feet for adequate monitoring of possible aerosol contaminants during the next decade. To study this problem the F-4C and F-15 aircraft were analyzed to determine their maximum altitude ability in zoom-climb maneuvers. These trajectories must satisfy realistic dynamic pressure and Mach number constraints. Maximum altitudes obtained for the F4-C are above 90,000 feet, and for the F-15 above 100,000 feet. Sensitivities of the zoom-climb altitudes were found with respect to several variables including vehicle thrust, initial weight, stratospheric winds and the constraints. A final decision on aircraft selection must be based on mission modification costs and operational considerations balanced against their respective zoom altitude performance capabilities.

  8. Cloning, expression, and analysis of the Mal f 6 allergen from Dermatophagoides farinae in China%粉尘螨变应原Der f Mal f 6的克隆、表达及生物信息学分析

    Institute of Scientific and Technical Information of China (English)

    孙金霞; 周鹰; 杨李; 俞黎黎; 王运刚; 卞勇华; 崔玉宝

    2013-01-01

    目的 克隆粉尘螨变应原Der f Mal f 6(简称Mal f 6)编码基因并构建其原核表达体系. 方法 提取粉尘螨总RNA,根据GenBank中的(AY283280.1)序列设计并合成引物,RT-PCR扩增Der f Mal f 6全长基因,克隆至pColdTF DNA载体,转化至E.coli JMI09,取阳性克隆测序;将pCold TF-Mal f 6质粒转化至BL21,IPTG诱导表达,采用SDS-PAGE验证表达产物,采用生物信息学软件预测Mal f 6的理化特性、结构和功能. 结果 RT-PCR获得全长为495 bp的Mal f 6基因.原核表达后经SDS-PAGE电泳显示其全细胞、上清及沉淀物均有蛋白表达,以上清表达量较高.生物信息学分析该蛋白由164个氨基酸组成,分子质量单位为17.7 ku,二级结构由α螺旋(4.88%)、延伸主链(37.8%)和无规则卷曲(57.32%)组成,是亲水性细胞质蛋白,具有肽酰-脯氨酰反式异构酶活性. 结论 粉尘螨变应原Mal f 6原核表达获得成功,为该变应原的进一步研究及规模生产和应用奠定了基础.%Objectives To acquire the cDNA of the Der f Malf 6 gene (Mal f 6) from Dermatophagoides farinae in China and construct a prokaryotic expression system.Methods Total RNA was extracted from D.farinae.The Malf 6 gene was amplified with RT-PCR and cloned into the pCold TF DNA vector.The pCold TF-Mal f 6 was then transformed into E.coli BL21 and induced by IPTG to express the gene.It was then identified with SDS-PAGE.Bioinformatics tools were used to analyze the physiochemical properties,secondary structure,and function of Malf 6.Results The Malf 6 gene was obtained by RT-PCR and was 495 bp in length.The constructed plasmid pCold TF-Mal f 6 was then transformed into E.coli BL21 and induced to express the gene.SDS-PAGE detected a specific band in whole cells,supernatant,and precipitate containing pCold TF-Mal f 6.Bioinformatics indicated that the allergen consisted of 164 amino acids and had a molecular weight of 17.7 KDa.Its secondary structure consisted of an alpha helix (4.88

  9. A novel mutation in POU3F4 in a Chinese family with X-linked non-syndromic hearing loss

    Institute of Scientific and Technical Information of China (English)

    Bang-qing Huang; Jia-ling Zeng; Yong-yi Yuan; Pu Dai

    2015-01-01

    Objective:Based on the clinical manifestations of a hearing loss patient, the POU3F4 gene was tested for diagnosis of etiology. Methods:A comprehensive physical examination was performed on the proband to exclude abnormalities of other organs, and detailed audi-ological testing and temporal bone CT scan were also performed. Genomic DNA was extracted using the proband's peripheral blood leukocytes. Polymerase chain reactions (PCR) were performed in the coding sequence of the POU3F4 gene. Direct DNA sequencing was subsequently applied to screen the entire coding region of the POU3F4 gene. Results:The proband had severe sensorineural hearing loss. Temporal CT showed bilateral cochlear incomplete partition, vestibule dysplasia, internal auditory canal fundus expansion, and cochlear interlink with the internal auditory canal fundus. A novel mutation (c.530C > A (p.S177X)) in the POU3F4 gene was found in this patient, creating an new stop codon and was predicted to result in a truncated protein lacking normal POU3F4 transcription factor function. Conclusion: Through analysis of the POU3F4 gene and clinical manifestations in the patient, we conclude that a novel mutation may have resulted in a premature stop codon, contributing to the mutation of POU3F4 gene.

  10. Polymorphisms of three gene-derived STS on Pig chromosome 13q41 are associated with susceptibility to enterotoxigenic Escherichia coli F4ab/ac in pigs

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiang; REN Jun; YAN XueMing; PENG QiuLing; TANG Huan; ZHANG Bo; JI HuaYuan; YANG ShuJin; HUANG LuSheng

    2008-01-01

    Neonatal diarrhea caused by enterotoxigenic Escherichia coli (ETEC) F4 is a common and serious disease, resulting in significant economical loss in the pig industry. The locus encoding ETEC F4 re-ceptor has been mapped to pig chromosome (SSC) 13q41, and one of the most significantly linked markers is S0075. In this study, we selected three genes including SLC12A8, MYLKand KPNA1 from a chromosomal region flanking S0075 on SSC13 to develop pig specific sequence tagged sites (STS). Seven single nucleotide polymorphisms were identified in the three pig STS using DNA of four full-sib susceptible and resistant animals in a White Duroc × Erhualian intercross. All grandparents, parents and 755 offspring in the intercross were genotyped for three polymorphisms, including SLC12A8 g.159AG, MYLK g.1673AG and KPNA1g.306AG. Family-based transmission disequilibrium test (TDT) revealed that.all polymorphisms and the corresponding haplotypes are significantly associated with ETEC F4ab/ac (especially F4ac) brush border adhesion phenotypes, indicating that these polymor-phism are in linkage disequlibrium with causal mutation(s) of the gene encoding ETEC F4ab/ac receptor. Our results strengthen the evidence for the involvement of SSC13q41 in high acquiring risk of ETEC F4ab/ac infection, and provide novel .polymorphic markers for fine mapping of the ETEC F4ab/ac re-ceptor locus.

  11. Analytical Variables Affecting Analysis of F2-Isoprostanes and F4-Neuroprostanes in Human Cerebrospinal Fluid by Gas Chromatography/Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Hsiu-Chuan Yen

    2013-01-01

    Full Text Available F2-isoprostanes (F2-IsoPs are a gold marker of lipid peroxidation in vivo, whereas F4-neuroprostanes (F4-NPs measured in cerebrospinal fluid (CSF or brain tissue selectively indicate neuronal oxidative damage. Gas chromatography/negative-ion chemical-ionization mass spectrometry (GC/NICI-MS is the most sensitive and robust method for quantifying these compounds, which is essential for CSF samples because abundance of these compounds in CSF is very low. The present study revealed potential interferences on the analysis of F2-IsoPs and F4-NPs in CSF by GC/NICI-MS due to the use of improper analytical methods that have been employed in the literature. First, simultaneous quantification of F2-IsoPs and F4-NPs in CSF samples processed for F4-NPs analysis could cause poor chromatographic separation and falsely higher F2-IsoPs values for CSF samples with high levels of F2-IsoPs and F4-NPs. Second, retention of unknown substances in GC columns from CSF samples during F4-NPs analysis and from plasma samples during F2-IsoPs analysis might interfere with F4-NPs analysis of subsequent runs, which could be solved by holding columns at a high temperature for a period of time after data acquisition. Therefore, these special issues should be taken into consideration when performing analysis of F2-IsoPs and F4-NPs in CSF to avoid misleading results.

  12. Discovery of a low-mass companion inside the debris ring surrounding the F5V star HD206893

    CERN Document Server

    Milli, Julien; Christiaens, Valentin; Choquet, Elodie; Bonnefoy, Mickael; Kennedy, Grant M; Wyatt, Mark C; Absil, Olivier; Gonzalez, Carlos A Gomez; del Burgo, Carlos; Matra, Luca; Augereau, Jean-Charles; Boccaletti, Anthony; Delacroix, Christian; Ertel, Steve; Dent, William R F; Forsberg, Pontus; Fusco, Thierry; Girard, Julien H; Habraken, Serge; Huby, Elsa; Karlsson, Mikael; Lagrange, Anne-Marie; Mawet, Dimitri; Mouillet, David; Perrin, Marshall; Pinte, Christophe; Pueyo, Laurent; Reyes, Claudia; Soummer, Remi; Surdej, Jean; Tarricq, Yoann; Wahhaj, Zahed

    2016-01-01

    Uncovering the ingredients and the architecture of planetary systems is a very active field of research that has fuelled many new theories on giant planet formation, migration, composition, and interaction with the circumstellar environment. We aim at discovering and studying new such systems, to further expand our knowledge of how low-mass companions form and evolve. We obtained high-contrast H-band images of the circumstellar environment of the F5V star HD206893, known to host a debris disc never detected in scattered light. These observations are part of the SPHERE High Angular Resolution Debris Disc Survey (SHARDDS) using the InfraRed Dual-band Imager and Spectrograph (IRDIS) installed on VLT/SPHERE. We report the detection of a source with a contrast of 3.6x10^{-5} in the H-band, orbiting at a projected separation of 270 milliarcsecond or 10 au, corresponding to a mass in the range 24 to 73 Mjup for an age of the system in the range 0.2 to 2 Gyr. The detection was confirmed ten months later with VLT/NaCo...

  13. Mechanism of isotactic styrene polymerization with a C 6F 5-substituted bis(phenoxyimine) titanium system

    KAUST Repository

    Caporaso, Lucia

    2012-11-13

    We report a combined, experimental and theoretical, study of styrene polymerization to clarify the regio- and stereocontrol mechanism operating with a C 6F 5-substituted bis(phenoxyimine) titanium dichloride complex. Styrene homopolymerization, styrene-propene and styrene-ethene-propene copolymerizations have been carried out to this aim. A combination of 13C NMR analysis of the chain-end groups and of the microstructure of the homopolymers and copolymers reveals that styrene polymerization is highly regioselective and occurs prevalently through 2,1-monomer insertion. DFT calculations evidenced that steric interaction between the growing chain and the monomer in the transition state insertion stage is at the origin of this selectivity. The formation of isotactic polystyrene with a chain-end like microstructure is rationalized on the base of a mechanism similar to that proposed for the syndiospecific propene polymerization catalyzed by bis(phenoxyimine) titanium dichloride complexes. Finally, a general stereocontrol mechanism operative in olefin polymerization with this class of complexes is proposed. © 2012 American Chemical Society.

  14. Interpretation of the 4f-5d Excitation Spectra of Eu3+ and Tb3+ Doped in Crystals

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The structure of the low-temperature 4fN→4fN-15d excitation spectra of Eu3+ and Tb3+ doped in crystals LiYF4, YPO4 and CaF2 measured by van Pieterson et al. In 2002 was analyzed and assigned based on the simple model proposed by Duan and co-workers in the last few years. Some complemental discussion on effects of J-mixing on the f-d transition intensities for Eu3+ due to the f-electron crystal-field interaction Hcf(f), which was ignored in the simple model, was presented. Some previously unexplained peaks for Tb3+ were interpreted to be spin-forbidden transitions to higher 5d crystal-field levels, or assigned to be f→d excitations with the core 4f7 excited from 8S to 6P, 6I and 6D, respectively. It is shown that the main structure of 4f-5d excitation spectra of Eu3+ and Tb3+ can be well interpreted with the simple model.

  15. Reactions of {[Pd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd](&mgr;-SC(6)F(5))}(4).2O(C(2)H(5))(2). Crystal Structures of the Complexes [(Ph(3)P)Pd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd(SC(6)F(5))].1.4CH(2)Cl(2) and [(Ph(3)P)Pd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd(PPh(3))]SO(3)CF(3).2CH(2)Cl(2) and ab Initio MO Calculations on the Model Systems [(H(3)P)Pd(&mgr;-H(2)PCH(2)PH(2))(&mgr;-SH)Pd(PH(3))](+) and [(H(3)P)Pd(&mgr;-H(2)PCH(2)PH(2))Pd(PH(3))](2+).

    Science.gov (United States)

    Usón, Rafael; Forniés, Juan; Fernández Sanz, Javier; Usón, Miguel A.; Usón, Isabel; Herrero, Santiago

    1997-04-23

    {[Pd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd](&mgr;-SC(6)F(5))}(4) reacts 1:4 with neutral ligands L to give [LPd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd(SC(6)F(5))] or 1:8 to form [LPd(&mgr;-SC(6)F(5))(&mgr;-dppm)PdL](+) (dppm = bis(diphenylphosphino)methane). These binuclear complexes retain the palladium-palladium bond and the two dissimilar bridging ligands, as demonstrated by the X-ray structural determinations carried out on [(Ph(3)P)Pd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd(SC(6)F(5))].1.4CH(2)Cl(2) and [(Ph(3)P)Pd(&mgr;-SC(6)F(5))(&mgr;-dppm)Pd(PPh(3))]SO(3)CF(3).2CH(2)Cl(2). Ab initio calculations on the model systems [(H(3)P)Pd(&mgr;-H(2)PCH(2)PH(2))(&mgr;-SH)Pd(PH(3))](+) and [(H(3)P)Pd(&mgr;-H(2)PCH(2)PH(2))Pd(PH(3))](2+) show that the metal-metal bond arises mainly from interactions between palladium sp orbitals, which also play a predominant role in the binding with the sulfur bridge.

  16. A modification potential method of calculating total cross sections of electrons scattering from complex molecules C2H6, C2F6, C6H6 and C6F6 at 100 eV-5000 eV

    Institute of Scientific and Technical Information of China (English)

    Shi De-Heng; Sun Jin-Feng; Zhu Zun-Lue; Liu Yu-Fang; Yang Xiang-Dong

    2006-01-01

    A complex optical model potential modified by incorporating the concept of bonded atom, which takes into consideration the overlapping effect of electron clouds between two atoms in a molecule, is first employed to calculate the total cross sections for electrons scattering from such complex molecules as C2H6, C2F6, C6H6 and C6F6 using the additivity rule model at Hartree-Fock level over the energy range from 100 eV to 5000 eV. The total cross sections are quantitatively compared with those obtained by experiments wherever available, and they are in good agreement with each other over a wide energy range. It is shown that the modified potential together with the additivity rule model is completely suitable for the calculation of total cross sections of electrons scattering from such complex molecules as C2H6, C2F6, C6H6 and C6F6 above 200 eV-300 eV.

  17. Catalytic CO2 activation assisted by rhenium hydride/B(C6F5)3 frustrated Lewis pairs--metal hydrides functioning as FLP bases.

    Science.gov (United States)

    Jiang, Yanfeng; Blacque, Olivier; Fox, Thomas; Berke, Heinz

    2013-05-22

    Reaction of 1 with B(C6F5)3 under 1 bar of CO2 led to the instantaneous formation of the frustrated Lewis pair (FLP)-type species [ReHBr(NO)(PR3)2(η(2)-O═C═O-B(C6F5)3)] (2, R = iPr a, Cy b) possessing two cis-phosphines and O(CO2)-coordinated B(C6F5)3 groups as verified by NMR spectroscopy and supported by DFT calculations. The attachment of B(C6F5)3 in 2a,b establishes cooperative CO2 activation via the Re-H/B(C6F5)3 Lewis pair, with the Re-H bond playing the role of a Lewis base. The Re(I) η(1)-formato dimer [{Re(μ-Br)(NO)(η(1)-OCH═O-B(C6F5)3)(PiPr3)2}2] (3a) was generated from 2a and represents the first example of a stable rhenium complex bearing two cis-aligned, sterically bulky PiPr3 ligands. Reaction of 3a with H2 cleaved the μ-Br bridges, producing the stable and fully characterized formato dihydrogen complex [ReBrH2(NO)(η(1)-OCH═O-B(C6F5)3)(PiPr3)2] (4a) bearing trans-phosphines. Stoichiometric CO2 reduction of 4a with Et3SiH led to heterolytic splitting of H2 along with formation of bis(triethylsilyl)acetal ((Et3SiO)2CH2, 7). Catalytic reduction of CO2 with Et3SiH was also accomplished with the catalysts 1a,b/B(C6F5)3, 3a, and 4a, showing turnover frequencies (TOFs) between 4 and 9 h(-1). The stoichiometric reaction of 4a with the sterically hindered base 2,2,6,6-tetramethylpiperidine (TMP) furnished H2 ligand deprotonation. Hydrogenations of CO2 using 1a,b/B(C6F5)3, 3a, and 4a as catalysts gave in the presence of TMP TOFs of up to 7.5 h(-1), producing [TMPH][formate] (11). The influence of various bases (R2NH, R = iPr, Cy, SiMe3, 2,4,6-tri-tert-butylpyridine, NEt3, PtBu3) was studied in greater detail, pointing to two crucial factors of the CO2 hydrogenations: the steric bulk and the basicity of the base.

  18. Cloning, Expression, Purification and Identification of Der f6 Gene and its Immunological Characteristics from the Dust House Mite%粉尘螨6类变应原(Der f6)的克隆表达、纯化及免疫学特性鉴定

    Institute of Scientific and Technical Information of China (English)

    朱永烽; 刘志刚; 高波

    2006-01-01

    目的 构建粉尘螨6类变应原(Dermatophagoides farinae,Der f6)基因的高效原核表达载体,并进行表达、纯化及生物学功能分析.方法 根据Der f6基因已知序列,设计1对引物,通过对纯培养的粉尘螨提取总RNA,采用RT-PCR方法扩增出Der f6基因片段,PCR产物克隆入pMD18-T载体,转化大肠埃希菌(E.coli Top10),经PCR和酶切鉴定并测序.将上述所得阳性克隆菌株扩大培养,碱裂解法提取质粒,所得重组质粒pMD18-T-Der f6和空质粒pET-24a同时用限制性内切酶EcoR Ⅰ和Xho Ⅰ双酶切,经纯化后连接并转化至E.coli Top10.构建的重组质粒pET24a-Der f6经PCR、酶切和测序鉴定后,再转化至E.coli BL21(DE3),异丙基-β-D-硫代半乳糖苷(IPTG)诱导表达.用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)和蛋白质印迹法(Western blotting)鉴定其表达效果,用Ni+离子亲和层析柱纯化重组质粒pET24a-Der f6表达产生的组氨酸重组蛋白.结果 构建了重组质粒pMD18-T-Der f6和pET24a-Der f6.SDS-PAGE结果表明Der f6基因在E.coli Bl21(DE3)中获得良好的表达,所得重组蛋白相对分子质量(Mr)为31 000,与理论值一致,经亲和层析纯化后,SDS-PAGE结果显示单一条带.该蛋白以尘螨过敏患者血清进行Western blotting,结果表明具有良好的IgE结合活性.结论 克隆、表达并纯化了具有良好尘螨致敏患者IgE结合活性的Der f6.

  19. The type F6 neurotoxin gene cluster locus of group II clostridium botulinum has evolved by successive disruption of two different ancestral precursors.

    Science.gov (United States)

    Carter, Andrew T; Stringer, Sandra C; Webb, Martin D; Peck, Michael W

    2013-01-01

    Genome sequences of five different Group II (nonproteolytic) Clostridium botulinum type F6 strains were compared at a 50-kb locus containing the neurotoxin gene cluster. A clonal origin for these strains is indicated by the fact that sequences were identical except for strain Eklund 202F, with 10 single-nucleotide polymorphisms and a 15-bp deletion. The essential topB gene encoding topoisomerase III was found to have been split by the apparent insertion of 34.4 kb of foreign DNA (in a similar manner to that in Group II C. botulinum type E where the rarA gene has been disrupted by a neurotoxin gene cluster). The foreign DNA, which includes the intact 13.6-kb type F6 neurotoxin gene cluster, bears not only a newly introduced topB gene but also two nonfunctional botulinum neurotoxin gene remnants, a type B and a type E. This observation combined with the discovery of bacteriophage integrase genes and IS4 elements suggest that several rounds of recombination/horizontal gene transfer have occurred at this locus. The simplest explanation for the current genotype is that the ancestral bacterium, a Group II C. botulinum type B strain, received DNA firstly from a strain containing a type E neurotoxin gene cluster, then from a strain containing a type F6 neurotoxin gene cluster. Each event disrupted the previously functional neurotoxin gene. This degree of successive recombination at one hot spot is without precedent in C. botulinum, and it is also the first description of a Group II C. botulinum genome containing more than one neurotoxin gene sequence.

  20. Chain Sprockets Manufacturing, on Vertical Machining Center GDV400PM1F4 Updated with Numerical Control NCT®2000M

    Directory of Open Access Journals (Sweden)

    Ioan Francisc Fekete

    2013-06-01

    Full Text Available The paper content comprise a few aspects regarding processing of chain sprockets on vertical processing center GDV400PM1F4 updated by changing the original equipment CNC-2S42-65 (1Я3.035.090 with NCT®2000M, which includes in short characteristics of two CNC, the old and the new one, the constructive elements of chain sprockets processed, enunciation of mains stages of manufacturing process adopted. The aim is to manufacture chain sprockets with classic tools, bypassing the need to design and build a sprocket hob in accordance with specified chain sprockets geometry, processing is performed on a machine which technological parameters have been improved.

  1. ϕ 3 theory with F4 flavor symmetry in 6 - 2 ɛ dimensions: 3-loop renormalization and conformal bootstrap

    Science.gov (United States)

    Pang, Yi; Rong, Junchen; Su, Ning

    2016-12-01

    We consider ϕ 3 theory in 6 - 2 ɛ with F 4 global symmetry. The beta function is calculated up to 3 loops, and a stable unitary IR fixed point is observed. The anomalous dimensions of operators quadratic or cubic in ϕ are also computed. We then employ conformal bootstrap technique to study the fixed point predicted from the perturbative approach. For each putative scaling dimension of ϕ (Δ ϕ ), we obtain the corresponding upper bound on the scaling dimension of the second lowest scalar primary in the 26 representation ( Δ 26 2nd ) which appears in the OPE of ϕ × ϕ. In D = 5 .95, we observe a sharp peak on the upper bound curve located at Δ ϕ equal to the value predicted by the 3-loop computation. In D = 5, we observe a weak kink on the upper bound curve at ( Δ ϕ , Δ 26 2nd ) = (1.6, 4).

  2. Investigation of hole transport in α-NPD using impedance spectroscopy with F4TCNQ as hole-injection layer

    Science.gov (United States)

    Fernandes, Jean Maria; Kiran, M. Raveendra; Ulla, Hidayath; Satyanarayan, M. N.; Umesh, G.

    2015-07-01

    The charge carrier transport is studied in N,N‧-di(1-naphthyl)-N,N‧-diphenyl-(1,1‧-biphenyl)-4,4‧-diamine (α-NPD) with the incorporation of sequentially doped p-type dopant 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) as hole-injection layer in hole-only device structures. The field dependent mobility of the charge carriers is determined using frequency dependent capacitance, conductance and impedance methods by varying the thickness of α-NPD. The Poole-Frenkel zero-field mobility and the Poole-Frenkel coefficient thus obtained for each device in all the three methods is found to be almost constant.

  3. Thermodynamic assessment of the LiF-CeF3-ThF4 system: Prediction of PuF3 concentration in a molten salt reactor fuel

    Science.gov (United States)

    Beneš, O.; Konings, R. J. M.

    2013-04-01

    A thermodynamic description of the LiF-CeF3-ThF4 system is made in this study using a two-sublattice model for the description of the solid solution and a quasi-chemical model based on quadruplet approximation for the liquid phase. New calorimetric experimental data of the binary LiF-CeF3, CeF3-ThF4 and ternary LiF-CeF3-ThF4 systems have been obtained in this work justifying the calculated phase diagrams. Using the obtained thermodynamic assessment the concentration of PuF3 in the LiF-ThF4 melt was estimated based on the similarities with CeF3 and the melting behaviour of the initial molten salt fast reactor fuel was discussed.

  4. Trapping of Li(+) Ions by [ThFn](4-n) Clusters Leading to Oscillating Maxwell-Stefan Diffusivity in the Molten Salt LiF-ThF4.

    Science.gov (United States)

    Chakraborty, Brahmananda; Kidwai, Sharif; Ramaniah, Lavanya M

    2016-08-18

    A molten salt mixture of lithium fluoride and thorium fluoride (LiF-ThF4) serves as a fuel as well as a coolant in the most sophisticated molten salt reactor (MSR). Here, we report for the first time dynamic correlations, Onsager coefficients, Maxwell-Stefan (MS) diffusivities, and the concentration dependence of density and enthalpy of the molten salt mixture LiF-ThF4 at 1200 K in the composition range of 2-45% ThF4 and also at eutectic composition in the temperature range of 1123-1600 K using Green-Kubo formalism and equilibrium molecular dynamics simulations. We have observed an interesting oscillating pattern for the MS diffusivity for the cation-cation pair, in which ĐLi-Th oscillates between positive and negative values with the amplitude of the oscillation reducing as the system becomes rich in ThF4. Through the velocity autocorrelation function, vibrational density of states, radial distribution function analysis, and structural snapshots, we establish an interplay between the local structure and multicomponent dynamics and predict that formation of negatively charged [ThFn](4-n) clusters at a higher ThF4 mole % makes positively charged Li(+) ions oscillate between different clusters, with their range of motion reducing as the number of [ThFn](4-n) clusters increases, and finally Li(+) ions almost get trapped at a higher ThF4% when the electrostatic force on Li(+) exerted by various surrounding clusters gets balanced. Although reports on variations of density and enthalpy with temperature exist in the literature, for the first time we report variations of the density and enthalpy of LiF-ThF4 with the concentration of ThF4 (mole %) and fit them with the square root function of ThF4 concentration, which will be very useful for experimentalists to obtain data over a range of concentrations from fitting the formula for design purposes. The formation of [ThFn](4-n) clusters and the reduction in the diffusivity of the ions at a higher ThF4% may limit the

  5. Mirror Neurons in Monkey Premotor Area F5 Show Tuning for Critical Features of Visual Causality Perception.

    Science.gov (United States)

    Caggiano, Vittorio; Fleischer, Falk; Pomper, Joern K; Giese, Martin A; Thier, Peter

    2016-11-21

    Humans derive causality judgments reliably from highly abstract stimuli, such as moving discs that bump into each other [1]. This fascinating visual capability emerges gradually during human development [2], perhaps as consequence of sensorimotor experience [3]. Human functional imaging studies suggest an involvement of the "action observation network" in the processing of such stimuli [4, 5]. In addition, theoretical studies suggest a link between the computational mechanisms of action and causality perception [6, 7], consistent with the fact that both functions require an analysis of sequences of spatiotemporal relationships between interacting stimulus elements. Single-cell correlates of the perception of causality are completely unknown. In order to find such neural correlates, we investigated the responses of "mirror neurons" in macaque premotor area F5 [8, 9]. These neurons respond during the observation as well as during the execution of actions and show interesting invariances, e.g., with respect to the stimulus view [10], occlusions [11], or whether an action is really executed or suppressed [12]. We investigated the spatiotemporal properties of the visual responses of mirror neurons to naturalistic hand action stimuli and to abstract stimuli, which specified the same causal relationships. We found a high degree of generalization between these two stimulus classes. In addition, many features that strongly reduced the similarity of the response patterns coincided with the ones that also destroy the perception of causality in humans. This implies an overlap of neural structures involved in the processing of actions and the visual perception of causality at the single-cell level. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Mechanism of Action of TiF4 on Dental Enamel Surface: SEM/EDX, KOH-Soluble F, and X-Ray Diffraction Analysis.

    Science.gov (United States)

    Comar, Lívia P; Souza, Beatriz M; Al-Ahj, Luana P; Martins, Jessica; Grizzo, Larissa T; Piasentim, Isabelle S; Rios, Daniela; Buzalaf, Marília Afonso Rabelo; Magalhães, Ana Carolina

    2017-10-12

    This in vitro study aimed to evaluate the action of TiF4 on sound and carious bovine and human enamel. Sound (S) and pre-demineralised (DE) bovine and human (primary and permanent) enamel samples were treated with TiF4 (pH 1.0) or NaF varnishes (pH 5.0), containing 0.95, 1.95, or 2.45% F for 12 h. The enamel surfaces were analysed using SEM-EDX (scanning electron microscopy/energy-dispersive X-ray spectroscopy) (n = 10, 5 S and 5 DE) and KOH-soluble fluoride was quantified (n = 20, 10 S and 10 DE). Hydroxyapatite powder produced by precipitation method was treated with the corresponding fluoride solutions for 1 min (n = 2). The formed compounds were detected using X-ray diffraction (XRD). All TiF4 varnishes produced a coating layer rich in Ti and F on all types of enamel surface, with micro-cracks in its extension. TiF4 (1.95 and 2.45% F) provided higher fluoride deposition than NaF, especially for bovine enamel (p enamel. The Ti content was higher for bovine and human primary enamel than human permanent enamel, with some differences between S and DE. The XRD analysis showed that TiF4 induced the formation of new compounds such as CaF2, TiO2, and Ti(HPO4)2·H2O. In conclusion, TiF4 (>0.95% F) interacts better, when compared to NaF, with bovine and human primary enamel than with human permanent enamel. TiF4 provoked higher F deposition compared to NaF. Carious enamel showed higher F uptake than sound enamel by TiF4 application, while Ti uptake was dependent on the enamel condition and origin. © 2017 S. Karger AG, Basel.

  7. Lanthanide 4f-level location in lanthanide doped and cerium-lanthanide codoped NaLaF4 by photo- and thermoluminescence

    NARCIS (Netherlands)

    Krumpel, A.H.; Van der Kolk, E.; Zeelenberg, D.; Bos, A.J.J.; Krämer, K.W.; Dorenbos, P.

    2008-01-01

    Photo- and thermoluminescence (TL) spectra of NaLaF4:Ln3+ (Ln = Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm) and NaLaF4:Ce3+, Ln3+ (Ln = Nd,Sm,Ho,Er,Tm) are presented and used together with the empirical Dorenbos model in order to establish the 4f energy level positions of all tri- and divalent lanthanide ions

  8. Compositional and Structural Versatility in an Unusual Family of anti-Perovskite Fluorides: [Cu(H2O)4]3[(MF6)(M'F6)].

    Science.gov (United States)

    Felder, Justin B; Yeon, Jeongho; Smith, Mark D; Zur Loye, Hans-Conrad

    2016-07-18

    A series of six anti-perovskite fluorides of the type [Cu(H2O)4]3(M1-xM'xF6)2 (where M and M' = V, Cr, Mn, Fe as well as M = Fe and M' = V and Cr) was synthesized as high-quality single crystals via a mild hydrothermal route. These materials belong to a class of perovskite-based structures in which the anions and cations of the regular ABX3 perovskite structure have exchanged positions. Two complex anions, MF6(3-) and M'F6(3-), occupy the normal A and B cation positions, while three complex cations, [Cu(H2O)4](2+), occupy the normally anionic X positions. As in the ABX3 compositions, the A and B positions can be occupied by different complex anions, allowing for the preparation of a wide range of compositions. Magnetic property measurements were performed on all six phases, and complex magnetic behavior was observed at low temperatures in the Mn, Fe, and bimetallic Fe/V and Fe/Cr phases.

  9. Enhancing the photovoltaic performance of CdTe/CdS solar cell via luminescent downshifting using K2SiF6:Mn4+ phosphors

    Science.gov (United States)

    Talewar, R. A.; Joshi, C. P.; Moharil, S. V.

    2016-05-01

    The efficiency of CdTe/CdS solar cell can be significantly improved by using luminescent down-shifting material on their front surface. Taking this into account a red emitting phosphor K2Si1-xF6:xMn4+ (x=10 to 25 mol %) has been synthesized through wet chemical method. The as-synthesized materials were characterized by powder x-ray diffraction (XRD) and photoluminescence (PL) techniques. The photoluminescence studies of K2SiF6:Mn4+ revealed enhancement in the emission intensity, when Mn4+ concentration was increased from 10 mol % to 25 mol %. This red emitting phosphor efficiently absorbs the photons typically in the region 300-500 nm and re-emits in the region where the photovoltaic device exhibits significantly better response. The results show the possibility of enhancing the photovoltaic conversion efficiency of CdTe thin film solar cell by modifying the absorption spectra and utilising the energy in the UV-blue part of the solar spectrum.

  10. Dnmt3b recruitment through E2F6 transcriptional repressor mediates germ-line gene silencing in murine somatic tissues.

    Science.gov (United States)

    Velasco, Guillaume; Hubé, Florent; Rollin, Jérôme; Neuillet, Damien; Philippe, Cathy; Bouzinba-Segard, Haniaa; Galvani, Angélique; Viegas-Péquignot, Evani; Francastel, Claire

    2010-05-18

    Methylation of cytosine residues within the CpG dinucleotide in mammalian cells is an important mediator of gene expression, genome stability, X-chromosome inactivation, genomic imprinting, chromatin structure, and embryonic development. The majority of CpG sites in mammalian cells is methylated in a nonrandom fashion, raising the question of how DNA methylation is distributed along the genome. Here, we focused on the functions of DNA methyltransferase-3b (Dnmt3b), of which deregulated activity is linked to several human pathologies. We generated Dnmt3b hypomorphic mutant mice with reduced catalytic activity, which first revealed a deregulation of Hox genes expression, consistent with the observed homeotic transformations of the posterior axis. In addition, analysis of deregulated expression programs in Dnmt3b mutant embryos, using DNA microarrays, highlighted illegitimate activation of several germ-line genes in somatic tissues that appeared to be linked directly to their hypomethylation in mutant embryos. We provide evidence that these genes are direct targets of Dnmt3b. Moreover, the recruitment of Dnmt3b to their proximal promoter is dependant on the binding of the E2F6 transcriptional repressor, which emerges as a common hallmark in the promoters of genes found to be up-regulated as a consequence of impaired Dnmt3b activity. Therefore, our results unraveled a coordinated regulation of genes involved in meiosis, through E2F6-dependant methylation and transcriptional silencing in somatic tissues.

  11. Dimensional Crossover and Its Interplay with In-Plane Anisotropy of Upper Critical Field in β-(BDA-TTP)2SbF6

    Science.gov (United States)

    Yasuzuka, Syuma; Koga, Hiroaki; Yamamura, Yasuhisa; Saito, Kazuya; Uji, Shinya; Terashima, Taichi; Akutsu, Hiroki; Yamada, Jun-ichi

    2017-08-01

    Resistance measurements have been performed to investigate the dimensionality and the in-plane anisotropy of the upper critical field (Hc2) for β-(BDA-TTP)2SbF6 in fields H up to 15 T and at temperatures T from 1.5 to 7.5 K, where BDA-TTP stands for 2,5-bis(1,3-dithian-2-ylidene)-1,3,4,6-tetrathiapentalene. The upper critical fields parallel and perpendicular to the conduction layer are determined and dimensional crossover from anisotropic three-dimensional behavior to two-dimensional behavior is found at around 6 K. When the direction of H is varied within the conducting layer at 6.0 K, Hc2 shows twofold symmetry: Hc2 along the minimum Fermi wave vector (maximum Fermi velocity) is larger than that along the maximum Fermi wave vector (minimum Fermi velocity). The normal-state magnetoresistance has twofold symmetry similar to Hc2 and shows a maximum when the magnetic field is nearly parallel to the maximum Fermi wave vector. This tendency is consistent with the Fermi surface anisotropy. At 3.5 K, we found clear fourfold symmetry of Hc2 despite the fact that the normal-state magnetoresistance shows twofold symmetry arising from the Fermi surface anisotropy. The origin of the fourfold symmetry of Hc2 is discussed in terms of the superconducting gap structure in β-(BDA-TTP)2SbF6.

  12. Site Selective Excitation and Energy Transfer in LiKGdF5 Crystal Co-doped with Er3+ and Tb3+

    Institute of Scientific and Technical Information of China (English)

    Yin Min(尹民); Khaidukov N M; Krupa J C

    2004-01-01

    Crystals of LiKGdF5∶Er3+, Tb3+ grown by the hydrothermal synthesis technique with concentrations of 2% and 0.4% were analysed. By using site selective excitation measured at low temperature, luminescence and excitation spectra from Er3+ and Tb3+ ions embedded in LiKGdF5 were clearly separated. The lifetimes of the emitting levels 4S3/2 of Er3+ and 5D4 of Tb3+ were also determined. Following the site selective spectroscopy study, the dominant energy transfer process from Tb3+ to Er3+ in the crystal was then investigated via transient experiments.

  13. Telaprevir- and boceprevir-based tritherapies in real practice for F3-F4 pretreated hepatitis C virus patients

    Institute of Scientific and Technical Information of China (English)

    Delphine; Bonnet; Matthieu; Guivarch; Ana?s; Palacin; Laurent; Alric; Emilie; Bérard; Jean-Marc; Combis; Andre; Jean; Remy; Andre; Glibert; Jean-Louis; Payen; Sophie; Metivier; Karl; Barange; Herve; Desmorat; Florence; Nicot; Florence; Abravanel

    2014-01-01

    AIM:To assess,in a routine practice setting,the sus-tained virologic response(SVR) to telaprevir(TPV) or boceprevir(BOC) in hepatitis C virus(HCV) nullresponders or relapsers with severe liver fibrosis.METHODS:One hundred twenty-five patients were treated prospectively for 48 wk with TPV or BOC + pegylated-interferon(peg-INF) α2a + ribavirin(PR) according to standard treatment schedules without randomization.These patients were treated in routine practice settings in 10 public or private health care centers,and the data were prospectively collected.Only patients with severe liver fibrosis(Metavir scores of F3 or F4 upon liver biopsy or liver stiffness assessed by elastography),genotype 1 HCV and who were null-responders or relapsers to prior PR combination therapy were included in this study.RESULTS:The Metavir fibrosis scores were F3 in 35(28%) and F4 in 90(72%) of the patients.In total,62.9% of the patients were null-responders and 37.1% relapsers to the previous PR therapy.The overall SVR rate at 24 wk post-treatment withdrawal was 59.8%.The SVR was 65.9% in the TPV group and 44.1% in the BOC group.Independent predictive factors of an SVR included a response to previous treatment,relapsers vs null-responders [OR = 3.9;(1.4,10.6),P = 0.0084],a rapid virological response(RVR) [OR 6.9(2.6,18.2),P = 0.001] and liver stiffness lower than 21.3 kPa [OR = 8.2(2.3,29.5),P = 0.001].During treatment,63 patients(50.8%) had at least one severe adverse event(SAE) of grade 3 or 4.A multivariate analysis identified two factors associated with SAEs:female gender [OR = 2.4(1.1,5.6),P = 0.037] and a platelet count below 150 × 103/ mm3 [OR = 5.3(2.3,12.4),P ≤ 0.001].CONCLUSION:More than half of these difficult-to-treat patients achieved an SVR and had SAEs in an actual practice setting.The SVR rate was influenced by the response to previous PR treatment,the RVR and liver stiffness.

  14. Continuous measurements of SiF4 and SO2 by thermal emission spectroscopy: Insight from a 6-month survey at the Popocatépetl volcano

    Science.gov (United States)

    Taquet, N.; Meza Hernández, I.; Stremme, W.; Bezanilla, A.; Grutter, M.; Campion, R.; Palm, M.; Boulesteix, T.

    2017-07-01

    The processes linked with the emplacement and growth/destruction of a lava dome are of prime importance to understand the stability of such extrusions and assess the associated risks for local populations. During the last couple of decades, ground and space-based spectroscopic techniques have been developed to monitor such processes from a safe distance. Such approaches significantly improved our knowledge about the relationship between the chemical composition of the volcanic gas plumes and both the deep and shallow volcanic processes leading to the different types of explosive activity. The potential of the ground-based thermal emission Fourier Transform Infrared spectroscopy (FTIR) remained under-exploited due to the difficulty to properly handle the radiative-transfer phenomena. Despite the drawbacks in the complex analytical requirements, this method enables to continuously monitor (day and night) with a high temporal resolution (1 meas/3 min), relevant gas species such as SO2 and SiF4 in the volcanic plumes. Previous studies have related the temporal variations of the SiF4/SO2 ratio in volcanic plumes to the onset of vulcanian explosions. This study reports a 6-month SO2, SiF4, and SiF4/SO2 time series (from January to June 2015) of the Popocatepetl's gas plume obtained from FTIR thermal emission spectroscopic measurements. The infrared spectra were analyzed using the SFIT4 radiative transfer and inverse model, which we have adapted for this application. We obtained highly variable SiF4/SO2 ratios with a mean value of 3.6 × 10- 4, with the highest values (around 3 × 10- 3) measured during the final phase of a lava dome growth (February-March 2015). The rapid SiF4/SO2 variations were more carefully explored and compared for the first time with the seismic activity. A remarkable coincidence between sharp SiF4/SO2 rises and the seismic events are evidenced here.

  15. Multifunctional BaYbF5: Gd/Er upconversion nanoparticles for in vivo tri-modal upconversion optical, X-ray computed tomography and magnetic resonance imaging.

    Science.gov (United States)

    Li, Xiaolong; Yi, Zhigao; Xue, Zhenluan; Zeng, Songjun; Liu, Hongrong

    2017-06-01

    Development of high-quality upconversion nanoparticles (UCNPs) with combination of the merits of multiple molecular imaging techniques, such as, upconversion luminescence (UCL) imaging, X-ray computed tomography (CT), and magnetic resonance (MR) imaging, could significantly improve the accuracy of biological diagnosis. In this work, multifunctional BaYbF5: Gd/Er (50:2mol%) UCNPs were synthesized via a solvothermal method using oleic acid (OA) as surface ligands (denoted as OA-UCNPs). The OA-UCNPs were further treated by diluted HCl to form ligand-free UCNPs (LF-UCNPs) for later bioimaging applications. The cytotoxicity assay in HeLa cells shows low cell toxicity of these LF-UCNPs. Owing to the efficient UCL of BaYbF5: Gd/Er, the LF-UCNPs were successfully used as luminescent bioprobe in UCL bioimaging. And, X-ray CT imaging reveals that BaYbF5: Gd/Er UCNPs can act as potential contrast agents for detection of the liver and spleen in the live mice owing to the high-Z elements (e.g., Ba, Yb, and Gd) in host matrix. Moreover, with the addition of Gd, the as-designed UCNPs exhibit additional positive contrast enhancement in T1-weighted MR imaging. These findings demonstrate that BaYbF5: Gd/Er UCNPs are potential candidates for tri-modal imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Organically templated uranium(IV) fluorooxalates with layer structures: (H4TREN)[U2F6(C2O4)3].4H2O (TREN = tris(2-aminoethyl)amine) and (H4APPIP)[U2F6(C2O4)3].4H2O (APPIP = 1,4-bis(3-amino-propyl)piperazine).

    Science.gov (United States)

    Wang, Chih-Min; Wu, Yi-Ying; Chen, Pei-Lin; Lii, Kwang-Hwa

    2007-03-14

    Two organically-templated layered uranium(IV) fluorooxalates, (H(4)TREN)[U(2)F(6)(C(2)O(4))(3)].4H(2)O (1) (TREN = tris(2-aminoethyl)amine) and (H(4)APPIP)[U(2)F(6)(C(2)O(4))(3)].4H(2)O (2) (APPIP = 1,4-bis(3-aminopropyl)piperazine), have been synthesized by hydrothermal methods and structurally characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and magnetic susceptibility. Both structures consist of anionic [U(2)F(6)(C(2)O(4))(3)](4-) layers separated by organic ammonium cations and lattice water molecules. The UF(3)O(6) polyhedra are connected by oxalate ligands in different ways within the layers. They are the first examples of organically-templated uranium fluorooxalates. Crystal data for compound 1 follow: monoclinic, P2(1)/c (No. 14), a = 19.1563(5) A, b = 8.9531(2) A, c = 16.6221(4) A, beta = 114.633(1) degrees, and Z = 4. Crystal data for compound are the same as those for 1 except a = 10.3309(8) A, b = 15.564(1) A, c = 17.537(1) A, and beta = 95.430(4) degrees.

  17. Yellow laser performance of Dy$^{3+}$ in co-doped Dy,Tb:LiLuF$_4$

    CERN Document Server

    Bolognesi, Giacomo; Calonico, Davide; Costanzo, Giovanni Antonio; Levi, Filippo; Metz, Philip Werner; Kränkel, Christian; Huber, Günter; Tonelli, Mauro

    2015-01-01

    We present laser results obtained from a Dy$^{3+}$-Tb$^{3+}$ co-doped LiLuF$_{4}$ crystal, pumped by a blue emitting InGaN laser diode, aiming for the generation of a compact 578 nm source. We exploit the yellow Dy$^{3+}$ transition $^{4}$F$_{9/2}$ $\\Longrightarrow$ $^{6}$H$_{13/2}$ to generate yellow laser emission. The lifetime of the lower laser level is quenched via energy transfer to co-doped Tb$^{3+}$ ions in the fluoride crystal. We report the growth technique, spectroscopic study and room temperature continuous wave (cw) laser results in a hemispherical cavity at 574 nm and with a highly reflective output coupler at 578 nm. A yellow laser at 578 nm is very relevant for metrological applications, in particular for pumping of the forbidden $^{1}$S$_{0} \\Longrightarrow ^{3}$P$_{0}$ Ytterbium clock transition, which is recommended as a secondary representation of the second in the international system (SI) of units. This paper was published in Optics Letters and is made available as an electronic reprint ...

  18. Twisted compactification of N=2 5D SCFTs to three and two dimensions from F(4) gauged supergravity

    CERN Document Server

    Karndumri, Parinya

    2015-01-01

    We study supersymmetric $AdS_4\\times \\Sigma_2$ and $AdS_3\\times \\Sigma_3$ solutions in half-maximal gauged supergravity in six dimensions with $SU(2)_R\\times SU(2)$ gauge group. The gauged supergravity is obtained by coupling three vector multiplets to the pure $F(4)$ gauged supergravity. The $SU(2)_R$ R-symmetry together with the $SO(3)\\sim SU(2)$ symmetry of the vector multiplets are gauged. The resulting gauged supergravity admits supersymmetric $AdS_6$ critical points with $SO(4)\\sim SU(2)\\times SU(2)$ and $SO(3)\\sim SU(2)_{\\textrm{diag}}$ symmetries. The former corresponds to five-dimensional $N=2$ superconformal field theories (SCFTs) with $E_1\\sim SU(2)$ symmetry. We find new classes of supersymmetric $AdS_4\\times \\Sigma_2$ and $AdS_3\\times \\Sigma_3$ solutions with $\\Sigma_{2,3}$ being $S^{2,3}$ and $H^{2,3}$. These solutions describe SCFTs in three and two dimensions obtained from twisted compactifications of the aforementioned five-dimensional SCFTs with different numbers of unbroken supersymmetry an...

  19. $\\phi^3$ theory with $F_4$ flavor symmetry in $6-2\\epsilon$ dimensions: 3-loop renormalization and conformal bootstrap

    CERN Document Server

    Pang, Yi; Su, Ning

    2016-01-01

    We consider $\\phi^3$ theory in $6-2\\epsilon$ with $F_4$ global symmetry. The beta function is calculated up to 3 loops, and a stable unitary IR fixed point is observed. The anomalous dimensions of operators quadratic or cubic in $\\phi$ are also computed. We then employ conformal bootstrap technique to study the fixed point predicted from the perturbative approach. For each putative scaling dimension of $\\phi$ ($\\Delta_{\\phi})$, we obtain the corresponding upper bound on the scaling dimension of the second lowest scalar primary in the ${\\mathbf 26}$ representation $(\\Delta^{\\rm 2nd}_{{\\mathbf 26}})$ which appears in the OPE of $\\phi\\times\\phi$. In $D=5.95$, we observe a sharp peak on the upper bound curve located at $\\Delta_{\\phi}$ equal to the value predicted by the 3-loop computation. In $D=5$, we observe a weak kink on the upper bound curve at $(\\Delta_{\\phi},\\Delta^{\\rm 2nd}_{{\\mathbf 26}})$=$(1.6,4)$.

  20. Controlled Isotropic and Anisotropic Shell Growth in β-NaLnF4 Nanocrystals Induced by Precursor Injection Rate.

    Science.gov (United States)

    Fischer, Stefan; Swabeck, Joseph K; Alivisatos, A Paul

    2017-09-06

    Precise morphology and composition control is vital for designing multifunctional lanthanide-doped core/shell nanocrystals. Herein, we report controlled isotropic and anisotropic shell growth techniques in hexagonal sodium rare-earth tetrafluoride (β-NaLnF4) nanocrystals by exploiting the kinetics of the shell growth. A drastic change of the shell morphology was observed by changing the injection rate of the shell precursors while keeping all other reaction conditions constant. We obtained isotropic shell growth for fast sequential injection and a preferred growth of the shell layers along the crystal's c-axis [001] for slow dropwise injection. Using this slow shell growth technique, we have grown rod-like shells around different almost spherical core nanocrystals. Bright and efficient upconversion was measured for both isotropic and rod-like shells around β-NaYF4 nanocrystals doped with Yb(3+)/Er(3+) and Yb(3+)/Tm(3+). Photoluminescence upconversion quantum yield and lifetime measurements reveal the high quality of the core/shell nanocrystal. Furthermore, multishell rod-like nanostructures have been prepared with optically active cores and tips separated by an inert intermediate shell layer. The controlled anisotropic shell growth allows the design of new core/multishell nanostructures and enables independent investigations of the chemistry and physics of different nanocrystal facets.

  1. Estimating the probability of polyreactive antibodies 4E10 and 2F5 disabling a gp41 trimer after T cell-HIV adhesion.

    Directory of Open Access Journals (Sweden)

    Bin Hu

    2014-01-01

    Full Text Available A few broadly neutralizing antibodies, isolated from HIV-1 infected individuals, recognize epitopes in the membrane proximal external region (MPER of gp41 that are transiently exposed during viral entry. The best characterized, 4E10 and 2F5, are polyreactive, binding to the viral membrane and their epitopes in the MPER. We present a model to calculate, for any antibody concentration, the probability that during the pre-hairpin intermediate, the transient period when the epitopes are first exposed, a bound antibody will disable a trivalent gp41 before fusion is complete. When 4E10 or 2F5 bind to the MPER, a conformational change is induced that results in a stably bound complex. The model predicts that for these antibodies to be effective at neutralization, the time to disable an epitope must be shorter than the time the antibody remains bound in this conformation, about five minutes or less for 4E10 and 2F5. We investigate the role of avidity in neutralization and show that 2F5 IgG, but not 4E10, is much more effective at neutralization than its Fab fragment. We attribute this to 2F5 interacting more stably than 4E10 with the viral membrane. We use the model to elucidate the parameters that determine the ability of these antibodies to disable epitopes and propose an extension of the model to analyze neutralization data. The extended model predicts the dependencies of IC50 for neutralization on the rate constants that characterize antibody binding, the rate of fusion of gp41, and the number of gp41 bridging the virus and target cell at the start of the pre-hairpin intermediate. Analysis of neutralization experiments indicate that only a small number of gp41 bridges must be disabled to prevent fusion. However, the model cannot determine the exact number from neutralization experiments alone.

  2. Lattice dynamics of Cs2NaYbF6 and Cs2NaYF6 elpasolites: Ab initio calculation

    Science.gov (United States)

    Chernyshev, V. A.; Petrov, V. P.; Nikiforov, A. E.; Zakir'yanov, D. O.

    2015-06-01

    The ab initio calculations of the crystal structure and the phonon spectrum of Cs2NaYbF6 and Cs2NaYF6 crystals with the elpasolite structure have been performed. The frequencies and types of fundamental vibrations have been determined. The calculations have been performed in the framework of the density functional theory using the molecular orbital method with hybrid functionals in the CRYSTAL09 program developed for the simulation of periodic structures. The outer 5 s and 5 p shells of the rare-earth ion have been described in Gaussian-type basis sets. The influence of inner shells, including 4 f electron shells, on the outer shells has been described using the pseudopotential. It has been shown that this approach allows the description of the phonon spectrum with the inclusion of the splitting of the longitudinal and transverse optical modes.

  3. The volatile composition of comets C 2009/P1 (Garradd) and C 2012/F6 (Lemmon) from ground-based radio observations

    Science.gov (United States)

    Gicquel, A.; Milam, S.; Cordiner, M.; Villanueva, G.; Charnley, S.; Coulson, I.; Remijan, A.; DiSanti, M. A.; Bonev, B. P.; Kuan, Y.-J.; Chuang, Y.-L.

    2013-09-01

    Comets provide important clues to the physical and chemical processes that occurred during the formation and early evolution of the Solar System, and could also have been important for initiating prebiotic chemistry on the early Earth [1]. Comparing abundances and cosmogonic values (isotope and ortho:para (o/p) ratios) of cometary parent volatiles to those found in the interstellar medium, in disks around young stars, and between cometary families, is vital to understanding planetary system formation and the processing history experienced by organic matter in the so-called interstellar-comet connection [2]. A major observational challenge in cometary science is to quantify the extent to which chemical compounds can be linked to either the interstellar or nebular reservoirs. We report an analysis of ground-based radio observations towards comets C/2009 P1 (Garradd) and C/2012 F6 (Lemmon) to constrain the chemical history of these bodies.

  4. Slurry Erosion Behavior of F6NM Stainless Steel and High-Velocity Oxygen Fuel-Sprayed WC-10Co-4Cr Coating

    Science.gov (United States)

    Cui, S. Y.; Miao, Q.; Liang, W. P.; Huang, B. Z.; Ding, Z.; Chen, B. W.

    2017-02-01

    WC-10Co-4Cr coating was applied to the surface of F6NM stainless steel by high-velocity oxygen-fuel spraying. The slurry erosion behavior of the matrix and coating was examined at different rotational speeds using a self-made machine. This experiment effectively simulates real slurry erosion in an environment with high silt load. At low velocity (<6 m/s), the main failure mechanism was cavitation. Small bubbles acted as an air cushion, obstructing direct contact between sand and the matrix surface. However, at velocity above 9 m/s, abrasive wear was the dominant failure mechanism. The results indicate that WC-10Co-4Cr coating significantly improved the slurry resistance at higher velocity, because it created a thin and dense WC coating on the surface.

  5. Marker-assisted selection on E. coli F4ab/ac resistance and the effect on neonatal survival in piglets

    DEFF Research Database (Denmark)

    Jørgensen, Claus Bøttcher; Anderson, Susan I.; Cirera, Susanna;

    Enterotoxigenic Escherichia coli (ETEC) that express the F4ab or F4ac fimbriae (formerly known as K88ab/ac) are major causes of diarrhea and death in neonatal and young pigs. A locus controlling susceptibility towards ETEC F4ab/ac has previously been mapped to pig chromosome 13q41. A number...... to the genomic sequence of pig mucin 4 we also report on more than 15 SNPs discovered in the porcine MUC4 sequence. Collaboration with the Danish Slaughterhouses on genotyping of the intron 7 SNP of Mucin 4 in 6.373 breeding boars (3.432 Landrace and 2.941 Large White) and analysis of their offspring has...... revealed data of relevance to neonatal survival. Analysis on offspring from 6.373 animals show a highly significant (P

  6. Pharmacokinetics of amoxicillin administered in drinking water to recently weaned 3- to 4-week-old pigs with diarrhea experimentally induced by Escherichia coli O149 : F4

    DEFF Research Database (Denmark)

    Jensen, G.M.; Lykkesfeldt, J.; Frydendahl, K.;

    2006-01-01

    Objective-To measure effects of Escherichia coli 0149:F4-induced diarrhea on water consumption and pharmacokinetics of amoxicillin after administration in drinking water. Animals-24 recently weaned 24- to 28-day-old crossbred pigs. Procedure-10 pigs were inoculated with E coli O149:F4; all 10 pigs...... of amoxicillin may be appropriate for administration in drinking water during a 4-hour period on the first day that pigs have diarrhea attributable to E coli 0149:F4....... subsequently developed diarrhea. Pigs were medicated by administration of amoxicillin in the drinking water (0.75 mg/mL) for a 4-hour period on 2 consecutive days. Fourteen age-matched noninfected healthy pigs (control group) were medicated in a similar manner. Blood samples were obtained from both groups...

  7. Fabrication of a novel nanocomposite Ag/graphene@SiO2-NaLuF4:Yb,Gd,Er for large enhancement upconversion luminescence.

    Science.gov (United States)

    Yin, Dongguang; Cao, Xianzhang; Zhang, Lu; Tang, Jingxiu; Huang, Wenfeng; Han, Yanlin; Wu, Minghong

    2015-06-28

    Upconversion nanocrystals have a lot of advantages over other fluorescent materials. However, their applications are still limited due to their comparatively low upconversion luminescence (UCL). In the present study, a novel nanocomposite of Ag/graphene@SiO2-NaLuF4:Yb,Gd,Er for enhancing UCL was fabricated successfully, and its morphology, crystalline phase, composition, and fluorescent property were investigated. It is interesting to find that the Ag/graphene@SiO2-NaLuF4:Yb,Gd,Er and Ag@SiO2-NaLuF4:Yb,Gd,Er nanocomposites showed high UCL enhancements of 52- and 10-fold compared to the control of Ag-free nanocomposite SiO2-NaLuF4:Yb,Gd,Er, respectively. The enhancement of 52-fold is greater than those reported in our previous studies and some papers. Moreover, the measured life times of the Ag-presented nanocrystals were longer than that of Ag-absent counterparts. These enhancements of UCL can be ascribed to the effect of metal-enhanced fluorescence, which is caused by the enhancement of the local electric field. The UCL intensity of Ag/graphene@SiO2-NaLuF4:Yb,Gd,Er was 5.2-fold higher than that of Ag@SiO2-NaLuF4:Yb,Gd,Er, indicating that graphene presented in the fabricated nanocomposite structure favors metal-enhanced UCL. The small-sized Ag nanoparticles anchored on the graphene sheet mutually enhanced each other's polarizability and surface plasmon resonance, resulting in a big metal-enhanced UCL. This study provides a new strategy for effectively enhancing the UCL of upconversion nanocrystals. The enhancement potentially increases the overall upconversion nanocrystal detectability for highly sensitive biological, medical, and optical detections.

  8. Influence of chemical bond length changes on the crystal field strength and “ligand metal” charge transfer transitions in Cs2GeF6 doped with Mn4+ and Os4+ ions

    Science.gov (United States)

    Brik, M. G.

    2007-07-01

    Detailed study of dependence of the crystal field strength 10Dq and lowest charge transfer (CT) energies for different interionic distances in Cs2GeF6:Mn4+ and Cs2GeF6:Os4+crystals is presented. The calculations were performed using the first-principles discrete-variational Dirac Slater (DV-DS) method. As a result, the functional dependencies of 10Dq and lowest CT energy on the metal ligand distance R were obtained without any fitting or semiempirical parameters. It was shown that 10Dq depends on R as 1/Rn, with n=4.0612 and 4.3874 for Cs2GeF6:Mn4+ and Cs2GeF6:Os4+, respectively. Two approximations (linear and quadratic) are obtained for the dependence of the lowest CT energy on R; CT energy decreases when R increases with dE(CT)/dR=-638 and -1080 cm-1/pm for Cs2GeF6:Mn4+ and Cs2GeF6:Os4+, respectively, if the linear approximation is used. These values can be used for estimations of the lowest CT energies for Mn4+ and Os4+ ions in other hosts with fluorine ligands. Estimations of the electron-vibrational interaction (EVI) constants, Huang Rhys parameters, and Stokes shifts for all the above-mentioned crystals were performed using the obtained 10Dq and E(CT) functions.

  9. E2F4 and ribonucleotide reductase mediate S-phase arrest in colon cancer cells treated with chlorophyllin.

    Science.gov (United States)

    Chimploy, Korakod; Díaz, G Dario; Li, Qingjie; Carter, Orianna; Dashwood, Wan-Mohaiza; Mathews, Christopher K; Williams, David E; Bailey, George S; Dashwood, Roderick H

    2009-11-01

    Chlorophyllin (CHL) is a water-soluble derivative of chlorophyll that exhibits cancer chemopreventive properties, but which also has been studied for its possible cancer therapeutic effects. We report here that human colon cancer cells treated with CHL accumulate in S-phase of the cell cycle, and this is associated with reduced expression levels of p53, p21, and other G(1)/S checkpoint controls. At the same time, E2F1 and E2F4 transcription factors become elevated and exhibit increased DNA binding activity. In CHL-treated colon cancer cells, bromodeoxyuridine pulse-chase experiments provided evidence for the inhibition of DNA synthesis. Ribonucleotide reductase (RR), a pivotal enzyme for DNA synthesis and repair, was reduced at the mRNA and protein level after CHL treatment, and the enzymatic activity was inhibited in a concentration-dependent manner both in vitro and in vivo. Immunoblotting revealed that expression levels of RR subunits R1, R2, and p53R2 were reduced by CHL treatment in HCT116 (p53(+/+)) and HCT116 (p53(-/-)) cells, supporting a p53-independent mechanism. Prior studies have shown that reduced levels of RR small subunits can increase the sensitivity of colon cancer cells to clinically used DNA-damaging agents and RR inhibitors. We conclude that by inhibiting R1, R2, and p53R2, CHL has the potential to be effective in the clinical setting, when used alone or in combination with currently available cancer therapeutic agents.

  10. Age at menarche and its association with the metabolic syndrome and its components: results from the KORA F4 study.

    Directory of Open Access Journals (Sweden)

    Doris Stöckl

    Full Text Available OBJECTIVE: The metabolic syndrome is a major public health challenge and identifies persons at risk for diabetes and cardiovascular disease. The aim of this study was to examine the association between age at menarche and the metabolic syndrome (IDF and NCEP ATP III classification and its components. DESIGN: 1536 women aged 32 to 81 years of the German population based KORA F4 study were investigated. Data was collected by standardized interviews, physical examinations, and whole blood and serum measurements. RESULTS: Young age at menarche was significantly associated with elevated body mass index (BMI, greater waist circumference, higher fasting glucose levels, and 2 hour glucose (oral glucose tolerance test, even after adjusting for the difference between current BMI and BMI at age 25. The significant effect on elevated triglycerides and systolic blood pressure was attenuated after adjustment for the BMI change. Age at menarche was inversely associated with the metabolic syndrome adjusting for age (p-values: <0.001 IDF, 0.003 NCEP classification and additional potential confounders including lifestyle and reproductive history factors (p-values: 0.001, 0.005. Associations remain significant when additionally controlling for recollected BMI at age 25 (p-values: 0.008, 0.033 or the BMI change since age 25 (p-values: 0.005, 0.022. CONCLUSION: Young age at menarche might play a role in the development of the metabolic syndrome. This association is only partially mediated by weight gain and increased BMI. A history of early menarche may help to identify women at risk for the metabolic syndrome.

  11. Mössbauer study on a two-dimensional random mixture with competing spin anisotropies K2Ni1- x Fe x F4

    Science.gov (United States)

    Ito, A.; Anma, T.

    1987-03-01

    Mössbauer measurements have been made on a two-dimensional (2D) random mixture K2Ni1- x Fe x F4 with competing spin anisotropies. The concentration versus temperature phase diagram predicted by Oguchi and Ishikawa for mixed systems with competition between orthorhombic anisotropies has been shown to exist in K2Ni1- x Fe x F4. The coexistence of two kinds of Mössbauer spectra is seen in the transition regions, and is believed to be an intrinsic property of this system.

  12. Fixed points subgroups by two involutive automorphisms $\\sigma, \\gamma$ of compact exceptional Lie groups $F_4, E_6$ and $E_7$

    OpenAIRE

    Miyashita, Toshikazu

    2010-01-01

    For simply connected compact exceptional Lie groups $G = F_4, E_6$ and $E_7$, we consider two involutions $\\sigma, \\gamma$ and determine the group structure of subgroups $G^{\\sigma,\\gamma}$ of $G$ which are the intersection $G^\\sigma \\cap G^{\\gamma}$ of the fixed points subgroups of $G^\\sigma$ and $G^{\\gamma}$. The motivation is as follows. In [1](see the References of this paper), we determine the group structure of $(F_4)^{\\sigma, \\sigma'}, (E_6)^{\\sigma, \\sigma'}$ and $(E_7)^{\\sigma, \\sigm...

  13. Ligand-Free Synthesis of Tunable Size Ln:BaGdF5 (Ln = Eu3+ and Nd3+) Nanoparticles: Luminescence, Magnetic Properties, and Biocompatibility

    OpenAIRE

    Becerro, Ana Isabel; González-Mancebo, D.; Cantelar, Eugenio; Cussó, Fernando; Stepien, Grazyna; Fuente, J.M. de la; Ocaña, Manuel

    2016-01-01

    Bifunctional and highly uniform Ln:BaGdF5 (Ln = Eu3+ and Nd3+) nanoparticles have been successfully synthesized using a solvothermal method consisting of the aging at 120 °C of a glycerol solution containing the corresponding Lanthanide acetylacetonates and butylmethylimidazolium tetrafluoroborate. The absence of any surfactant in the synthesis process rendered hydrophilic nanospheres (with tunable diameter from 45 nm 85 nm, depending on the cations concentration of the starting solution) whi...

  14. Antisite defects in Ce-doped YAG (Y3Al5O12): First-principles study on structures and 4f-5d transitions

    OpenAIRE

    Muñoz García, Ana Belén; Barandiarán, Zoila; Seijo, Luis

    2012-01-01

    This is an electronic version of an article published in Journal of Materials Chemistry. Muñoz García, A.B., Barandiarán, Z. and Luis Seijo. "Antisite defects in Ce-doped YAG (Y3Al5O12): First-principles study on structures and 4f-5d transitions". Journal of Materials Chemistry 22 (2012): 19888-19897

  15. Aspergillus fumigatus proteases, Asp f 5 and Asp f 13, are essential for airway inflammation and remodelling in a murine inhalation model.

    Science.gov (United States)

    Namvar, S; Warn, P; Farnell, E; Bromley, M; Fraczek, M; Bowyer, P; Herrick, S

    2015-05-01

    In susceptible individuals, exposure to Aspergillus fumigatus can lead to the development of atopic lung diseases such as allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS). Protease allergens including Asp f 5 and Asp f 13 from Aspergillus fumigatus are thought to be important for initiation and progression of allergic asthma. To assess the importance of secreted protease allergens Asp f 5 (matrix metalloprotease) and Asp f 13 (serine protease) in Aspergillus fumigatus-induced inflammation, airway hyperactivity, atopy and airway wall remodelling in a murine model following chronic exposure to secreted allergens. BALB/c mice were repeatedly intranasally dosed over the course of 5 weeks with culture filtrate from wild-type (WT), Asp f 5 null (∆5) or Asp f 13 null (∆13) strains of Aspergillus fumigatus. Airway hyper-reactivity was measured by non-invasive whole-body plethysmography, Th2 response and airway inflammation by ELISA and cell counts, whilst airway remodelling was assessed by histological analysis. Parent WT and ∆5 culture filtrates showed high protease activity, whilst protease activity in ∆13 culture filtrate was low. Chronic intranasal exposure to the three different filtrates led to comparable airway hyper-reactivity and Th2 response. However, protease allergen deleted strains, in particular ∆13 culture filtrate, induced significantly less airway inflammation and remodelling compared to WT culture filtrate. Aspergillus fumigatus-secreted allergen proteases, Asp f 5 and Asp f 13, are important for recruitment of inflammatory cells and remodelling of the airways in this murine model. However, deletion of a single allergen protease fails to alleviate airway hyper-reactivity and allergic immune response. Targeting protease activity of Aspergillus fumigatus in conditions such as SAFS or ABPA may have beneficial effects in preventing key aspects of airway pathology. © 2014 John Wiley & Sons Ltd.

  16. 慕尼黑“f5,6”画廊举办劳伦斯·席勒摄影展

    Institute of Scientific and Technical Information of China (English)

    丁丁

    2008-01-01

    德国慕尼黑“f5,6”画廊2007年底宣布,将举办美国摄影家劳伦斯·席勒(Lawrence Schiller)的摄影腱,包括他拍摄的玛剌莲·梦露,以及一些1960年代的历电影像。

  17. Prevalencia de antigenos fimbriales f4 y f18 en cerditos lactantes y destetados diarreicos en la provincia de Villa Clara, Cuba (Prevalence of f4 and f18 fimbrial antigens in diarrheal nursing and weaned piglets of the province of Villa Clara.

    Directory of Open Access Journals (Sweden)

    Castillo Cuenca. Julio César

    2012-06-01

    Full Text Available RESUMENEl presente trabajo se realizó con el objetivo de determinar la prevalencia de antígenos fimbriales F4 y F18 en cerditos lactantes y destetados diarreicos de la Provincia de Villa Clara.SUMMARYThe present work was carried out with the objective of determining the prevalence of F4 and F18 fimbrial antigens in diarrheal nursing and weaned piglets of the Province of Villa Clara.

  18. Isotopic Ratios of H, C, N, O, and S in Comets C2012 F6 (lemmon) and C2014 Q2 (lovejoy) * ** ***

    Science.gov (United States)

    Biver, N.; Moreno, R.; Sandqvist, Aa.; Bockelee-Morvan, D.; Colom, P.; Crovisier, J.; Lis, D. C.; Bossier, J.; Debout, V.; Paubert, G.; Milam, S.; Hjalmarson, A.; Lundin, S.; Karlsson, T.; Battelino, M.; Frisk, U.; Murtagh, D.

    2016-01-01

    The apparition of bright comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy) in March-April 2013 and January 2015, combined with the improved observational capabilities of submillimeter facilities, offered an opportunity to carry out sensitive compositional and isotopic studies of the volatiles in their coma. We observed comet Lovejoy with the IRAM 30 meter telescope between 13 and 26 January 2015, and with the Odin submillimeter space observatory on 29 January - 3 February 2015. We detected 22 molecules and several isotopologues. The H2 O-16 and H2 O-18 production rates measured with Odin follow a periodic pattern with a period of 0.94 days and an amplitude of approximately 25 percent. The inferred isotope ratios in comet Lovejoy are O-16/O-18 = 499 +/- 24 and D/H equals 1.4 +/- 0.4 x 10(exp -4) in water, S-32/S-34 = equals 24.7 +/- 3.5 in CS, all compatible with terrestrial values. The ratio C-12/C-13 equals 109 +/- 14 in HCN is marginally higher than terrestrial and 14 N/ 15/N equals 145 +/- 12 in HCN is half the Earth ratio. Several upper limits for D/H or C-12/ C-13 in other molecules are reported. From our observation of HDO in comet C/2014 Q2 (Lovejoy), we report the first D/H ratio in an Oort Cloud comet that is not larger than the terrestrial value. On the other hand, the observation of the same HDO line in the other Oort-cloud comet, C/2012 F6 (Lemmon), suggests a D/H value four times higher. Given the previous measurements of D/H in cometary water, this illustrates that a diversity in the D/H ratio and in the chemical composition, is present even within the same dynamical group of comets, suggesting that current dynamical groups contain comets formed at very different places or times in the early solar system.

  19. Examining the Effects of Different Ring Configurations and Equatorial Fluorine Atom Positions on CO 2 Sorption in [Cu(bpy) 2 SiF 6

    KAUST Repository

    Forrest, Katherine A.

    2013-10-02

    Simulations of CO2 sorption were performed in a metal-organic material (MOM) that is part of a "SIFSIX" family of compounds that has remarkable carbon dioxide capture and separation properties. The MOM considered here has the formula [Cu(bpy)2SiF6] (bpy = 4,4′-bipyridine). This hydrophobic MOM is both water-stable and CO 2-specific with significant sorption capacity under ambient conditions. The crystal structure reveals bpy rings and equatorial fluorine atoms in multiple possible orientations; the static disorder has been modeled based on single-crystal X-ray diffraction data revealing several possible relatives of atoms in the crystal structure. With regards to the bpy rings, the structure can be interpreted as two pyridyl rings with coplanar configurations within a unit cell (configuration 1), a twisted bpy ring conformation in which orthogonal pyridyl rings have C4 symmetry about the Cu2+ ion (configuration 2), and a twisted bpy ring conformation in which the two orthogonal pyridyl rings are facing one another within a unit cell (configuration 3). Further, the equatorial fluorine atoms can be positioned such that all atoms are eclipsed with the square grid (position A), oriented at a 21.3 angle with respect to the square grid (position B), and oriented at a 45 angle with respect to the square grid (position C). It was observed that experimental data for CO2 sorption were only consistent with sorption into configurations 1 and 3 with any of the possible equatorial fluorine atom positions at ambient temperatures, although simulations using position A produced slightly higher uptakes in these bpy ring configurations. It is demonstrated that the orientation of the bpy rings in configurations 1 and 3 allows more space for the sorbate molecules and thus promotes favorable MOM-sorbate interactions, resulting in isotherms in line with the experimental results. The results from this study suggests that [Cu(bpy)2SiF 6] in either configuration 1 or 3 with CO2 present in

  20. Artificial miRNA-mediated down-regulation of two monolignoid biosynthetic genes (C3H and F5H) cause reduction in lignin content in jute.

    Science.gov (United States)

    Shafrin, Farhana; Das, Sudhanshu Sekhar; Sanan-Mishra, Neeti; Khan, Haseena

    2015-11-01

    Artificial microRNAs (amiRNA) provide a new feature in the gene silencing era. Concomitantly, reducing the amount of lignin in fiber-yielding plants such as jute holds significant commercial and environmental potential, since this amount is inversely proportional to the quality of the fiber. The present study aimed at reducing the lignin content in jute, by introducing amiRNA based vectors for down-regulation of two monolignoid biosynthetic genes of jute, coumarate 3-hydroxylase (C3H) and ferulate 5-hydroxylase (F5H). The transgenic lines of F5H-amiRNA and C3H-amiRNA showed a reduced level of gene expression, which resulted in about 25% reduction in acid insoluble lignin content for whole stem and 12-15% reduction in fiber lignin as compared to the non-transgenic plants. The results indicate successful F5H-amiRNA and C3H-amiRNA transgenesis for lignin reduction in jute. This is likely to have far-reaching commercial implications and economic acceleration for jute producing countries.

  1. (NH4)2SiF6预处理改善SBA-15介孔材料的水热稳定性%Improving the Hydrothermal Stability of Mesoporous Silica SBA-15by Pre-treatment with (NH4)2SiF6

    Institute of Scientific and Technical Information of China (English)

    宋明娟; 邹成龙; 牛国兴; 赵东元

    2012-01-01

    (NH4)2SiF6预处理可对SBA-15介孔材料的表面缺陷进行补硅修正以及表面疏水化,从而明显改善SBA-15材料的水热稳定性.结果表明,用摩尔分数为5%的(NH4)2SiF6水溶液,按引入1%的SiO2计量对SBA-15进行处理后,其水热稳定性明显改善,在100℃沸水中处理14d,或在800℃下用100%水蒸气处理12h后,均保持较好的介观有序度、形貌及六方孔道结构,比表面积分别高达310和213 m2/g,但(NH4)2SiF6处理量过高,SBA-15水热稳定性反而下降.%The hydrothermal stability of the mesoporous silica material SBA-15 was improved by a pre-treatment of 5 mol% ammonium hexafluorosilicate solution with 1 mol% SiO2 ratio of (NH4)2SiF6 and SBA-15. The modified SBA-15 kept its ordered meso-structure well even when kept under boiling water for 14 d or 100 % H2O stream at 800 ℃ for 12 h, and still had BET surface areas as high as 310 and 213 m2/g, respectively, after these treatments. The possible reasons for the stabilization were that the surface defects of SBA-15 were partially repaired by silicon insertion and some silicon hydroxyls were replaced by F- ions. Larger amounts of ammonium hexafluorosilicate did not give more stabilization.

  2. Interlayer interaction of two-dimensional layered spin crossover complexes [FeIIH3L(Me)][FeIIL(Me)]X (X-=ClO4-, BF4-, PF6-, AsF6-, and SbF6-; H3L(Me)=tris[2-(((2-methylimidazol-4-yl)methylidene)amino)ethyl]amine).

    Science.gov (United States)

    Yamada, Masahiro; Ooidemizu, Makoto; Ikuta, Yuichi; Osa, Shutaro; Matsumoto, Naohide; Iijima, Seiichiro; Kojima, Masaaki; Dahan, Françoise; Tuchagues, Jean-Pierre

    2003-12-15

    A series of two-dimensional (2D) spin crossover complexes, [FeIIH3L(Me)][FeIIL(Me)]X (X-=ClO4-, BF4-, PF6-, AsF6-, SbF6-) 1-5, have been synthesized, where H3L(Me) denotes an hexadentate N6 tripodlike ligand containing three imidazole groups, tris[2-(((2-methylimidazol-4-yl)methylidene)amino)ethyl]amine. Compounds 1-5 exhibit a two-step (HS-[FeIIH3L(Me)](2+) + HS-[FeIIL(Me)]-) (HS-[FeIIH3L(Me)](2+) + LS-[FeIIL(Me)]-) (LS-[FeIIH3L(Me)](2+) + LS-[FeIIL(Me)]-) spin-transition. The crystal structure of [FeIIH3L(Me)][FeIIL(Me)]PF6 (3) was determined at 295, 200, and 100 K. The structure consists of homochiral extended 2D puckered sheets, in which the complementary [FeIIH3L(Me)](2+) and [FeIIL(Me)]- capped tripodlike components, linked together by imidazole-imidazolate hydrogen bonds, are alternately arrayed in an up-and-down mode. The Fe-N bond distances and angles revealed that the FeII sites of both constituting units are in the high-spin (HS) state at 295 K; at 200 K, the FeII sites of [FeIIH3L(Me)](2+) and [FeIIL(Me)]- are in the HS and low-spin (LS) states, respectively. The FeII sites of both constituting units are in the LS state at 100 K. The size of the counteranion affects significantly the intra- and interlayer interactions leading to modifications of the spin crossover behavior. The onset of the second spin-transition of the ClO4- (1) and BF4- (2) salts adjoins the first spin-transition, while a mixed (HS-[FeIIH3L(Me)](2+) + LS-[FeIIL(Me)]-) spin-state spans a temperature range as wide as 70 K for salts 3-5 with larger counteranions, PF6-, AsF6-, and SbF6-, respectively. Compounds 1 and 2 showed remarkable LIESST (light induced excited spin state trapping) and reverse-LIESST effects, whereas 3-5 showed no remarkable LIESST effect. The interlayer interaction due to the size of the counteranion is an important factor governing the spin crossover behavior and LIESST effect.

  3. Preparation of core-shell NaGdF4 nanoparticles doped with luminescent lanthanide ions to be used as upconversion-based probes.

    Science.gov (United States)

    Wang, Feng; Deng, Renren; Liu, Xiaogang

    2014-07-01

    Sodium gadolinium fluoride (NaGdF4) is an ideal host material for the incorporation of luminescent lanthanide ions because of its high photochemical stability, low vibrational energy and its ability to mediate energy exchanges between the lanthanide dopants. This protocol describes the detailed experimental procedure for synthesizing core-shell NaGdF4 nanoparticles that incorporate lanthanide ions into different layers for efficiently converting a single-wavelength, near-IR excitation into a tunable visible emission. These nanoparticles can then be used as luminescent probes in biological samples, in 3D displays, in solar energy conversion and in photodynamic therapy. The NaGdF4 nanoparticles are grown through co-precipitation in a binary solvent mixture of oleic acid and 1-octadecene. Doping by lanthanides with controlled compositions and concentrations can be achieved concomitantly with particle growth. The lanthanide-doped NaGdF4 nanoparticles then serve as seed crystals for subsequent epitaxial growth of shell layers comprising different lanthanide dopants. The entire procedure for the preparation and isolation of the core-shell nanoparticles comprising two epitaxial shell layers requires ∼15 h for completion.

  4. A facile synthesis approach and impact of shell formation on morphological structure and luminescent properties of aqueous dispersible NaGdF4:Yb/Er upconversion nanorods

    Science.gov (United States)

    Ansari, Anees A.; Yadav, Ranvijay; Rai, S. B.

    2016-12-01

    A general facile synthesis approach was used for fabrication of highly emissive aqueous dispersible hexagonal phase upconversion luminescent NaGdF4:Yb/Er nanorods (core NRs) through metal complex decomposition process. An inert NaGdF4 and porous silica layers were grafted surrounding the surface of each and every NRs to enhance their luminescence efficiency and colloidal dispersibility in aqueous environment. Optical properties in terms of band gap energy of core, core/shell, and silica-coated core/shell/SiO2 nanorods were observed to investigate the influence of surface coating, which was gradually decreased after surface coating because of increase crystalline size after growth of inert and silica shells. The inert shell formation before silica surface grafting, upconversion luminescence intensity was greatly improved by about 20 times, owing to the effective surface passivation of the seed core and, therefore, protection of Er3+ ion in the core from the nonradiative decay caused by surface defects. Moreover, after silica coating, core/shell nanorods shows strong upconversion luminescence property similar to the hexagonal upconversion core NRs. It is expected that these NaGdF4:Yb/Er@NaGdF4@SiO2 (core/shell/SiO2) NRs including highly upconversion emissive and aqueous dispersible properties make them an ideal materials for various photonic-based potential applications such as in upconversion luminescent bioimaging, magnetic resonance imaging, and photodynamic therapy.

  5. Effect of NaF, SnF2, and TiF4 Toothpastes on Bovine Enamel and Dentin Erosion-Abrasion In Vitro

    Directory of Open Access Journals (Sweden)

    Lívia Picchi Comar

    2012-01-01

    Full Text Available The aim of this study was to compare the effect of toothpastes containing TiF4, NaF, and SnF2 on tooth erosion-abrasion. Bovine enamel and dentin specimens were distributed into 10 groups (n=12: experimental placebo toothpaste (no F; NaF (1450 ppm F; TiF4 (1450 ppm F; SnF2 (1450 ppm F; SnF2 (1100 ppm F + NaF (350 ppm F; TiF4 (1100 ppm F + NaF (350 ppm F; commercial toothpaste Pro-Health (SnF2—1100 ppm F + NaF—350 ppm F, Oral B; commercial toothpaste Crest (NaF—1.500 ppm F, Procter & Gamble; abrasion without toothpaste and only erosion. The erosion was performed 4 × 90 s/day (Sprite Zero. The toothpastes’ slurries were applied and the specimens abraded using an electric toothbrush 2 × 15 s/day. Between the erosive and abrasive challenges, the specimens remained in artificial saliva. After 7 days, the tooth wear was evaluated using contact profilometry (μm. The experimental toothpastes with NaF, TiF4, SnF2, and Pro-Health showed a significant reduction in enamel wear (between 42% and 54%. Pro-Health also significantly reduced the dentin wear. The toothpastes with SnF2/NaF and TiF4/NaF showed the best results in the reduction of enamel wear (62–70% as well as TiF4, SnF2, SnF2/NaF, and TiF4/NaF for dentin wear (64–79% (P<0.05. Therefore, the experimental toothpastes containing both conventional and metal fluoride seem to be promising in reducing tooth wear.

  6. Molecular cloning and characterization of the porcine prostaglandin transporter (SLCO2A1: evaluation of its role in F4 mediated neonatal diarrhoea

    Directory of Open Access Journals (Sweden)

    Cox Eric

    2009-10-01

    Full Text Available Abstract Background Because prostaglandins are involved in many (pathophysiological processes, SLCO2A1 was already characterized in several species in an attempt to unravel specific processes/deficiencies. Here, we describe the molecular cloning and characterization of the porcine ortholog in order to evaluate its possible involvement in F4 enterotoxigenic E. coli mediated neonatal diarrhoea, based on a positional candidate gene approach study. Results Porcine SLCO2A1 is organized in 14 exons, containing an open reading frame of 1935 bp, encoding a 12-transmembrane organic anion cell surface transporter of 644 aa. The -388 to -5 upstream region comprises a (CpG48 island containing a number of conserved promoter elements, including a TATA box. A potential alternative promoter region was found in the conserved -973 to -700 upstream region. No consensus polyadenylation signal was discovered in the 3' UTR. Repeat sequences were found in 15% of all the non coding sequences. As expected for a multifunctional protein, a wide tissue distribution was observed. mRNA expression was found in the adrenal gland, bladder, caecum, colon (centripetal coil/centrifugal coil, diaphragm, duodenum, gallbladder, heart, ileum, jejunum, kidney, liver, longissimus dorsi muscle, lung, lymph node, mesenterium, rectum, spleen, stomach, tongue and ureter, but not in the aorta, oesophagus and pancreas. The promoter region and the exons (including the splice sites of SLCO2A1 were resequenced in 5 F4ab/ac receptor positive and 5 F4ab/ac receptor negative pigs. Two silent and 2 missense (both S → L at position 360 and 633 mutations were found, but none was associated with the F4ab/ac receptor phenotype. In addition, no phenotype associated differential mRNA expression or alternative/abberant splicing/polyadenylation was found in the jejunum. Conclusion The molecular cloning and characterization of porcine SLCO2A1 not only contributes to the already existing knowledge about the

  7. Isotopic ratios of H, C, N, O, and S in comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy)

    CERN Document Server

    Biver, N; Bockelée-Morvan, D; Sandqvist, Aa; Colom, P; Crovisier, J; Lis, D C; Boissier, J; Debout, V; Paubert, G; Milam, S; Hjalmarson, A; Lundin, S; Karlsson, T; Battelino, M; Frisk, U; Murtagh, D

    2016-01-01

    The apparition of bright comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy) in March-April 2013 and January 2015, combined with the improved observational capabilities of submillimeter facilities, offered an opportunity to carry out sensitive compositional and isotopic studies of the volatiles in their coma. We observed comet Lovejoy with the IRAM 30m telescope between 13 and 26 January 2015, and with the Odin submillimeter space observatory on 29 January - 3 February 2015. We detected 22 molecules and several isotopologues. The H$_2^{16}$O and H$_2^{18}$O production rates measured with Odin follow a periodic pattern with a period of 0.94 days and an amplitude of ~25%. The inferred isotope ratios in comet Lovejoy are $^{16}$O/$^{18}$O = 499 $\\pm$ 24 and D/H = 1.4 $\\pm$ 0.4 $\\times 10^{-4}$ in water, $^{32}$S/$^{34}$S = 24.7 $\\pm$ 3.5 in CS, all compatible with terrestrial values. The ratio $^{12}$C/$^{13}$C = 109 $\\pm$ 14 in HCN is marginally higher than terrestrial and $^{14}$N/$^{15}$N = 145 $\\pm$ 12 in HCN ...

  8. Effect of gliadins and HMW and LMW subunits of glutenin on dough properties in the F6 recombinant inbred lines from a bread wheat cross.

    Science.gov (United States)

    Nieto-Taladriz, M T; Perretant, M R; Rousset, M

    1994-04-01

    The storage proteins of 64 F2-derived F6 recombinant inbred lines (RILs) from the bread wheat cross 'Prinqual'/'Marengo' were analyzed. Parents differed at four loci: Gli-B1 (coding for gliadins), Glu-B1 (coding for HMW glutenin subunits), Glu-A3/Gli-A1 (coding for LMW glutenin subunits/gliadins) and Glu-D3 (coding for LMW glutenin subunits). The effect of allelic variation at these loci on tenacity, extensibility and dough strength as measured by the Chopin alveograph was determined. Allelic differences at the Glu-B1 locus had a significant effect on only tenacity. None of the allelic differences at either the Glu-A3/Gli-A1 or Glu-D3 loci had a significant effect on quality criteria. Allelic variation at the Gli-B1 locus significantly affected all of the dough properties. Epistatic effects between some of the loci considered contributed significantly to the variation in dough quality. Additive and epistatic effects each accounted for 15% of the variation in tenacity. Epistasis accounted for 15% of the variation in extensibility, whereas additive effects accounted for 4%. Epistasis accounted for 14% of the variation in dough strength, and additivity for 9%. The relative importance of epistatic effects suggest that they should be included in predictive models when breeding for breadmaking quality.

  9. Excited-state absorption of Cr3+ in LiCaAlF6: Effects of asymmetric distortions and intensity selection rules

    Science.gov (United States)

    Lee, H. W. H.; Payne, Stephen A.; Chase, L. L.

    1989-05-01

    We have measured the π-polarized excited-state absorption (ESA) spectra of the new laser material, LiCaAlF6:Cr3+ (hereafter, Cr3+:LiCAF). We have found that the peak cross section of the ESA band is 0.17×10-20 cm2. We are therefore able to explain the high efficiency previously observed for the Cr3+:LiCAF laser by noting that the peak emission cross section of 1.3×10-20 cm2 is much larger than this ESA cross section. As a result, the ESA does not diminish the value of the effective stimulated-emission cross section, in spite of its tendency to overlap the emission band in most Cr3+-doped crystals. It is then shown that the ESA transition is weak relative to the emission band because the t2u distortion present at the Al3+ site where the Cr3+ substitutes adds transition strength to the π-polarized 4A2-4T2 absorption and emission features, while it does not contribute oscillator strength to the ESA band. The 4T2-->4T1a ESA band is found to peak near 10 030 cm-1, rather than near 7600 cm-1 as expected on the basis of simple crystal-field theory. This is explained as being due to the influence of non-totally-symmetric distortions in the excited states of Cr3+.

  10. Study of 13Cr-4Ni-(Mo (F6NM Steel Grade Heat Treatment for Maximum Hardness Control in Industrial Heats

    Directory of Open Access Journals (Sweden)

    Massimo De Sanctis

    2017-09-01

    Full Text Available The standard NACE MR0175 (ISO 15156 requires a maximum hardness value of 23 HRC for 13Cr-4Ni-(Mo steel grade for sour service, requiring a double tempering heat treatment at temperature in the range 648–691 °C for the first tempering and 593–621 °C for the second tempering. Difficulties in limiting alloy hardness after the tempering of forged mechanical components (F6NM are often faced. Variables affecting the thermal behavior of 13Cr-4Ni-(Mo during single and double tempering treatments have been studied by means of transmission electron microscopy (TEM observations, X-ray diffraction measurements, dilatometry, and thermo-mechanical simulations. It has been found that relatively low Ac1 temperatures in this alloy induce the formation of austenite phase above 600 °C during tempering, and that the formed, reverted austenite tends to be unstable upon cooling, thus contributing to the increase of final hardness via transformation to virgin martensite. Therefore, it is necessary to increase the Ac1 temperature as much as possible to allow the tempering of martensite at the temperature range required by NACE without the detrimental formation of virgin martensite upon final cooling. Attempts to do so have been carried out by reducing both carbon (<0.02% C and nitrogen (<100 ppm levels. Results obtained herein show final hardness below NACE limits without an unacceptable loss of mechanical strength.

  11. Electrical conductivity of Na3AlF6-AlF3-Al2O3-CaF2-LiF(NaCl) system electrolyte

    Institute of Scientific and Technical Information of China (English)

    KAN Hong-min; WANG Zhao-wen; BAN Yun-gang; SHI Zhong-ning; QIU Zhu-xian

    2007-01-01

    A PGSTAT 30 and a BOOSTER 20A were used to measure cell impedance. Electrical conductivity was gained by the Continuously Varying Cell Constant Technique. Electrical conductivity of KCl was measured for comparison. The results prove that the method is reliable and accurate. The electrical conductivity of Na3AlF6-AlF3-Al2O3-CaF2-LiF(NaCl) system was studied by this method. Activation energy of conductance was obtained based on the experiment results. The experiments show that electrical conductivity is increased greatly with NaCl and LiF added. Increasing 1%LiF(mass fraction) results in corresponding increase of 0.0276 S/cm for superheat condition of 15 ℃. For NaCl, it is 0.024 S/cm. Electrical conductivity is increased by 0.003 S/cm with 1℃ temperature increase. The electrical conductivity is lower than that predicted by the WANG Model and higher than that predicted by the Choudhary Model.

  12. CeO2/NaF吸附剂的制备及其对MoF6的吸附性能研究%Preparation of adsorbent CeO2/NaF and its adsorption performance for MoF6

    Institute of Scientific and Technical Information of China (English)

    李洒洒; 程治强; 李杨娟; 龙德武; 龚昱; 窦强; 吴明红; 李晴暖

    2015-01-01

    Background: The fluoride volatility process has been developed to recover uranium from spent nuclear fuel. And the fluoride adsorption technique is usually applied in the purification and collection of UF6 during the fluoride volatility process.Purpose: This study aims to investigate the characteristics and sorption performance of a novel sorbent CeO2/NaF synthesized by doping NaF with CeF3.Methods: With polymer sodium carboxymethyl cellulose (CMC) as a binder and pore-forming agent, CeF3 and NaFwas mixed according to a mass ratio of 4:9:62, and then water were added (the ratio of CMC to water is 1:6). The porous CeO2/NaF adsorbent particles were prepared by a mixing, molding and sintering process. The characteristics and adsorption performance of the adsorbent particles were analyzed and characterized.Results: Specific surface area of CeO2/NaF was (0.84±0.04)m2·g−1, which was twice of NaF sorbent made under the same process. Porosity was 42.2%, which was larger than that of NaF sorbent. The initial adsorption rate of MoF6 on CeO2/NaF was much higher than that of NaF sorbent. The temperature zone for desorption of MoF6 from CeO2/NaF ranged from 150°C to 300°C, while there were two desorption zones for desorption of MoF6 from NaF sorbent, which varied from 100°C to 300°C and 350°C to 400°C, respectively. This phenomenon showed that CeO2 might stabilize Mo6+in MoF6. Conclusion: The physical properties of NaF could be changed by doping with CeO2, and its adsorption performance was also improved.%将作为粘结剂和造孔剂的高分子羧甲基纤维素钠(Carboxymethylcellulose, CMC)、CeF3和NaF按4:9:62的质量比例混合,再加一定量的水(CMC与水的比为1:6),通过混捏、成形和烧结等程序制得了一种新型的CeO2/NaF吸附剂颗粒。通过研究CeO2的掺杂对NaF吸附剂表观性质和吸附性能的影响发现:CeO2/NaF吸附剂的比表面积为(0.84±0.04) m2·g−1,是相同条件下制得的 NaF 吸附剂

  13. An Experimental Investigation of Effects of Fluxes (Na3AlF6 and K2TiF6), Element Alloys (Mg), and Composite Powders ((Al + TiC)CP and (Al + B4C)CP) on Distribution of Particles and Phases in Al-B4C and Al-TiC Composites

    Science.gov (United States)

    Mazaheri, Younes; Emadi, Rahmatollah; Meratian, Mahmood; Zarchi, Mehdi Karimi

    2017-01-01

    The wettability, incorporation, and gravity segregation of TiC and B4C particles into molten aluminum are important problems in the production of Al-TiC and Al-B4C composites by the casting techniques. In order to solve these problems, different methods consisting of adding the Na3AlF6 and K2TiF6 fluxes and Mg (as the alloying element) into the molten aluminum and injection of the (Al + TiC)CP and (Al + B4C)CP composite powders instead of B4C and TiC particles are evaluated. In this work, the conditions of sample preparation, such as particle addition temperature, stirring speed, and stirring time, are determined after many studies and tests. Microstructural characterizations of samples are investigated by scanning electron microscopy equipped with energy dispersive spectroscopy (EDS) and X-ray diffractometry. The results show better distribution and incorporation of TiCp and B4Cp in aluminum matrix when the fluxes are used, as well as EDS analysis of the interface between the matrix and reinforcement-strengthened formation of the different phases such as Al4C3 in the Al-TiC composites and Al3BC, TiB2 in the Al-B4C composites.

  14. An Experimental Investigation of Effects of Fluxes (Na3AlF6 and K2TiF6), Element Alloys (Mg), and Composite Powders ((Al + TiC)CP and (Al + B4C)CP) on Distribution of Particles and Phases in Al-B4C and Al-TiC Composites

    Science.gov (United States)

    Mazaheri, Younes; Emadi, Rahmatollah; Meratian, Mahmood; Zarchi, Mehdi Karimi

    2017-04-01

    The wettability, incorporation, and gravity segregation of TiC and B4C particles into molten aluminum are important problems in the production of Al-TiC and Al-B4C composites by the casting techniques. In order to solve these problems, different methods consisting of adding the Na3AlF6 and K2TiF6 fluxes and Mg (as the alloying element) into the molten aluminum and injection of the (Al + TiC)CP and (Al + B4C)CP composite powders instead of B4C and TiC particles are evaluated. In this work, the conditions of sample preparation, such as particle addition temperature, stirring speed, and stirring time, are determined after many studies and tests. Microstructural characterizations of samples are investigated by scanning electron microscopy equipped with energy dispersive spectroscopy (EDS) and X-ray diffractometry. The results show better distribution and incorporation of TiCp and B4Cp in aluminum matrix when the fluxes are used, as well as EDS analysis of the interface between the matrix and reinforcement-strengthened formation of the different phases such as Al4C3 in the Al-TiC composites and Al3BC, TiB2 in the Al-B4C composites.

  15. Shape-controlled tunable homochromatic luminescence and inner photoelectric effect of hexagonal Na1.23Ca0.12Y1.28Er0.24F6 phosphors.

    Science.gov (United States)

    Wang, Xiangfu; Yan, Xiaohong; Wang, Tao; Bu, Yanyan; Kan, Caixia; Chen, Yuan

    2012-05-21

    Novel hexagonal Na1.23Ca0.12Y1.28Er0.24F6 nanodisks, microtubes, and nanorods were synthesized hydrothermally for the first time. Time-dependent morphology evolution showed that the resulting nanodisks, microtubes, and nanorods were synthesized by a dissolution-reconstruction formation mechanism. With the help of a 980 nm semiconductor laser, tunable homochromatic luminescence was observed by exciting single hexagonal Na1.23Ca0.12Y1.28Er0.24F6 nanodisks, microtubes, and nanorods, respectively. Simultaneously, the inner photoelectric effect was witnessed in the hexagonal Na1.23Ca0.12Y1.28Er0.24F6 nanodisks, microtubes, and nanorods under 980 nm excitation. We attributed anomalous inner photoelectric current to the presence of a laser stepped resonant excitation energy migration in the Na1.23Ca0.12Y1.28Er0.24F6 matrix when a laser was applied to it. Simultaneous control of homochromatic luminescence and inner photoelectric effect were achieved by modifying morphological shapes of single Na1.23Ca0.12Y1.28Er0.24F6 phosphors.

  16. Isotopic ratios of H, C, N, O, and S in comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy)

    Science.gov (United States)

    Biver, N.; Moreno, R.; Bockelée-Morvan, D.; Sandqvist, Aa.; Colom, P.; Crovisier, J.; Lis, D. C.; Boissier, J.; Debout, V.; Paubert, G.; Milam, S.; Hjalmarson, A.; Lundin, S.; Karlsson, T.; Battelino, M.; Frisk, U.; Murtagh, D.; Odin Team

    2016-05-01

    The apparition of bright comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy) in March-April 2013 and January 2015, combined with the improved observational capabilities of submillimeter facilities, offered an opportunity to carry out sensitive compositional and isotopic studies of the volatiles in their coma. We observed comet Lovejoy with the IRAM 30 m telescope between 13 and 26 January 2015, and with the Odin submillimeter space observatory on 29 January-3 February 2015. We detected 22 molecules and several isotopologues. The H216O and H218O production rates measured with Odin follow a periodic pattern with a period of 0.94 days and an amplitude of ~25%. The inferred isotope ratios in comet Lovejoy are 16O/18O = 499 ± 24 and D/H = 1.4 ± 0.4 × 10-4 in water, 32S/34S = 24.7 ± 3.5 in CS, all compatible with terrestrial values. The ratio 12C/13C = 109 ± 14 in HCN is marginally higher than terrestrial and 14N/15N = 145 ± 12 in HCN is half the Earth ratio. Several upper limits for D/H or 12C/13C in other molecules are reported. From our observation of HDO in comet C/2014 Q2 (Lovejoy), we report the first D/H ratio in an Oort Cloud comet that is not larger than the terrestrial value. On the other hand, the observation of the same HDO line in the other Oort-cloud comet, C/2012 F6 (Lemmon), suggests a D/H value four times higher. Given the previous measurements of D/H in cometary water, this illustrates that a diversity in the D/H ratio and in the chemical composition, is present even within the same dynamical group of comets, suggesting that current dynamical groups contain comets formed at very different places or times in the early solar system. Based on observations carried out with the IRAM 30 m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).Odin is a Swedish-led satellite project funded jointly by the Swedish National Space Board (SNSB), the Canadian Space Agency (CSA), the National Technology Agency of Finland (Tekes) and the

  17. Shock wave studies of the pyrolysis of fluorocarbon oxygenates. I. The thermal dissociation of C3F6O and CF3COF.

    Science.gov (United States)

    Cobos, C J; Hintzer, K; Sölter, L; Tellbach, E; Thaler, A; Troe, J

    2017-01-25

    The thermal decomposition of hexafluoropropylene oxide, C3F6O, to perfluoroacetyl fluoride, CF3COF, and CF2 has been studied in shock waves highly diluted in Ar between 630 and 1000 K. The measured rate constant k1 = 1.1 × 10(14) exp(-162(±4) kJ mol(-1)/RT) s(-1) agrees well with literature data and modelling results. Using the reaction as a precursor, equimolar mixtures of CF3COF and CF2 were further heated. Combining experimental observations with theoretical modelling (on the CBS-QB3 and G4MP2 ab initio composite levels), CF3COF is shown to dissociate on two channels, either leading to CF2 + COF2 or to CF3 + FCO. By monitoring the CF2 signals, the branching ratio was determined between 1400 and 1900 K. The high pressure rate constants for the two channels were obtained from theoretical modelling as k5,∞(CF3COF → CF2 + COF2) = 7.1 × 10(14) exp(-320 kJ mol(-1)/RT) s(-1) and k6,∞(CF3COF → CF3 + FCO) = 3.9 × 10(15) exp(-355 kJ mol(-1)/RT) s(-1). The experimental results obtained at [Ar] ≈ 5 × 10(-6) mol cm(-3) were consistent with modelling results, showing that the reaction is in the falloff range of the unimolecular dissociation. The mechanism of secondary reactions following CF3COF dissociation has been analysed as well.

  18. Enzymolysis of aflatoxin B1 by Pseudomonas stutzeri F4 and analysis of the degrading products%施氏假单胞菌F4对黄曲霉毒素B1的酶解作用及其降解产物的初步分析

    Institute of Scientific and Technical Information of China (English)

    李文明; 杨文华; 李海星; 刘晓华; 曹郁生

    2013-01-01

    施氏假单胞菌F4能高效降解黄曲霉毒素B1(aflatoxin B1,AFB1).研究了F4的AFB1降解活性、降解动力学以及蛋白酶K和SDS对其降解性能的影响.F4细胞悬液与毒素共培养72 h后降解率达80.03%;蛋白酶K处理对降解率没有影响,SDS处理的细胞悬液基本丧失了降解活性.不同时间点的降解液上清液仍能有效降解残留AFB1,其中以60 h的降解液上清液活性较好,与残留AFB1继续作用48 h后降解率达84.30%;而经蛋白酶K处理后降解率仅为45.42%.低浓度AFB1诱导对菌体的降解活性没有影响.上述结果提示,F4通过胞内酶作用降解AFB1.高效液相色谱对产物分析表明,F4可将AFB1酶解为至少2种产物.%Pseudomonas stutzeri F4 is capable of removing aflatoxin B1 efficiently.The properties and the kinetics of aflatoxin B1 hydrolyzed by F4, and the influence of proteinase K and SDS on its degradation performance were investigated.After 72 h of cultivation, 80.03% of AFB1 was degraded by F4 cell suspension.Proteinase K had no affects on its degradation efficiency, while the degradation ability almost lost by SDS treatment.In addition, the cell-free supernatant of the degradation solution taken from different time also had the detoxification activity, and in which 60 h sample showed a better activity (84.30% AFB, was degraded after continuous cultivation for 48 h).When the supernatant treated with proteinase K, the degradation efficiency was decreased to 45.42%.Low concentration of AFB1 induction had no effect on the degradation activity.These results indicated that a F4 intracellular enzyme was responsible for the degradation of AFB1.Meanwhile, HPLC chromatograms demonstrated that AFB1 was degraded to at least two products.

  19. MABGEL 1: first phase 1 trial of the anti-HIV-1 monoclonal antibodies 2F5, 4E10 and 2G12 as a vaginal microbicide.

    Directory of Open Access Journals (Sweden)

    Georgina C Morris

    Full Text Available BACKGROUND: Monoclonal antibodies (mAbs which potently neutralize a broad range of HIV isolates are potential microbicide candidates. To date, topical application of mAbs in humans and their stability in vaginal secretions has not been studied. OBJECTIVES: To assess the pharmacokinetics and safety of the mAbs 2F5, 4E10 and 2G12 when applied vaginally in women. DESIGN: A randomized, double-blind, placebo-controlled phase 1 trial. METHODS: Twenty-eight healthy, sexually abstinent women administered 2.5 g of gel daily for 12 days containing either 10 or 20 mg/g of each mAb (MABGEL or placebo. Main clinical evaluations and sampling occurred at baseline, 1, 8, and 24 hours post-1st dose and 12 and 36 hours post-12th dose. RESULTS: After adjustment for dilution factors, median levels of 2F5, 4E10 and 2G12 in vaginal secretions at 1 hour post high-dose MABGEL were 7.74, 5.28 and 7.48 mg/ml respectively. Levels of 2F5 and 4E10 declined exponentially thereafter with similar estimated half-lives (4.6 and 4.3 hours. In contrast, 2G12 levels declined more rapidly in the first 8 hours, with an estimated half-life of 1.4 hours during this period. There was no evidence of systemic absorption. There were no significant differences in local or systemic adverse event rates or vaginal flora changes (by qPCR between active and placebo gel arms. Whilst at least 1 adverse event was recorded in 96% of participants, 95% were mild and none were serious. CONCLUSIONS: Vaginal application of 50 mg of each mAb daily was safe over a 12 day period. Median mAb concentrations detected at 8 hours post dose were potentially sufficient to block HIV transmission.2G12 exhibited more rapid elimination from the human vagina than 4E10 and 2F5, likely due to poor stability of 2G12 in acidic human vaginal secretions. Further research is needed to develop mAb-based vaginal microbicides and delivery systems. TRIAL REGISTRATION: ISRCTN 64808733 UK CRN Portfolio 6470.

  20. Experimental transition probabilities for several spectral lines arising from the 5d10 6s{8s, 7p, 5f, 5g} electronic configurations of Pb III

    OpenAIRE

    Alonso Medina, Aurelia

    2010-01-01

    Transition probabilities for 30 spectral lines, arising from the 5d10 6s{8s, 7p, 5f, 5g} electronic configurations of Pb III (20 measured for the first time), have been experimentally determined from measurements of emission line intensities in a plasma lead induced by ablation with a Nd:YAG laser. The line intensities were obtained with the target placed in molecular argon at 6 Torr, recorded at a 400 ns delay from the laser pulse, which provides appropriate measurement conditions, and analy...

  1. An ultrasmall and metabolizable PEGylated NaGdF4:Dy nanoprobe for high-performance T1/T2-weighted MR and CT multimodal imaging

    Science.gov (United States)

    Jin, Xiaoying; Fang, Fang; Liu, Jianhua; Jiang, Chunhuan; Han, Xueli; Song, Zhongkai; Chen, Jinxing; Sun, Guoying; Lei, Hao; Lu, Lehui

    2015-09-01

    Lanthanide-based multimodal probes with high sensitivity, simple synthesis strategy, and good biocompatibility promise new applications for clinical diagnosis. However, today's challenge is not only to develop high-performance multimodal probes for more accurate and reliable diagnosis, but also to understand the fate of these probes in vivo. In this context, a novel PEGylated Dy-doped NaGdF4 nanoprobe (PEG-NaGdF4:Dy) was designed and fabricated as a T1/T2-weighted MRI/CT imaging agent. This nanoprobe has a distinct longitudinal relaxivity (r1 = 5.17 mM-1 s-1), relatively high transverse relaxivity (r2 = 10.64 mM-1 s-1), and exhibits strong X-ray attenuation properties (44.70 HU L g-1) in vitro. Furthermore, T1/T2-weighted MRI/CT imaging in vivo confirmed that this PEG-NaGdF4:Dy nanoprobe could lead to a significant contrast enhancement effect on liver, spleen and kidney at 24 h post injection. The MTT assay, histological analysis, and biodistribution investigation demonstrated that this multifunctional nanoprobe possessed relatively low cytotoxicity, negligible tissue damage and could be completely excreted out of the body of mice as time prolonged. Therefore, the present PEG-NaGdF4:Dy nanoprobe has the potential for the development of multifunctional T1/T2-weighted MRI/CT imaging to provide more comprehensive and accurate diagnosis information.Lanthanide-based multimodal probes with high sensitivity, simple synthesis strategy, and good biocompatibility promise new applications for clinical diagnosis. However, today's challenge is not only to develop high-performance multimodal probes for more accurate and reliable diagnosis, but also to understand the fate of these probes in vivo. In this context, a novel PEGylated Dy-doped NaGdF4 nanoprobe (PEG-NaGdF4:Dy) was designed and fabricated as a T1/T2-weighted MRI/CT imaging agent. This nanoprobe has a distinct longitudinal relaxivity (r1 = 5.17 mM-1 s-1), relatively high transverse relaxivity (r2 = 10.64 mM-1 s-1), and

  2. Computer modelling of cryogenic etching in SF6 /O2 /SiF4 and CxFy inductively coupled plasmas

    Science.gov (United States)

    Zhang, Quan-Zhi; Bogaerts, Annemie

    2016-09-01

    Plasma etching plays a more and more important role in microchip fabrication, due to its anisotropy during surface processing. However, current state-of-the-art plasma processing faces significant challenges when going beyond 14 nm features, such as plasma induced damage. A novel process with limited plasma damage is cryogenic etching of low-k material with SF6 /O2 /SiF4 and CxFy plasmas. In this work, a hybrid Monte Carlo-fluid model is employed to describe the plasma behavior, including the species and temperature distributions and power deposition, for SF6 /O2 /SiF4 and CxFy gas mixtures, applied for cryogenic etching under various gas ratios and operating conditions, which can help to establish an optimal process window. Quan-Zhi Zhang gratefully acknowledges the Marie Sklodowska-Curie Action Individual Fellowships (MSCA-IF-2015-EF).

  3. Comparison of casein and whey in diets on performance, immune responses and metabolomic profile of weaning pigs challenged with E.coli F4

    DEFF Research Database (Denmark)

    Sugiharto, Sugiharto; Jensen, Bent Borg; Hedemann, Mette Skou

    2014-01-01

    The differences in amino acid composition in casein and whey have been thought to exert different immunomodulatory and metabolic effects. The objective of this study was to compare the effects of casein and whey on performance, immune responses and plasma metabolomic profile of weanling pigs...... challenged with E. coli F4. Two factorial experiments involving 24 weanling pigs were conducted. Diets containing casein or whey, and challenge with E. coli O149:F4 or not, were the two factors. Blood was sampled at the day before challenge and 4 and 7 days postchallenge. For measurement of mucosal immune...... responses and intestinal dimensions, samples were collected from the small intestine (SI) immediately after killing at 7 days postchallenge. Feeding the whey-diet decreased (P

  4. Ultralow threshold green lasing and optical bistability in ZBNA (ZrF4-BaF2-NaF-AlF3) microspheres

    Science.gov (United States)

    Wu, Yuqiang; Ward, Jonathan M.; Nic Chormaic, Síle

    2010-02-01

    Upconversion lasing and fluorescence from active microspheres fabricated from a novel fluorozirconate, Er3+ doped glass, ZBNA (ZrF4-BaF2-NaF-AlF3), when pumped at 978 nm via a tapered optical fiber is demonstrated. An ultralow, green lasing threshold of ˜3 μW for 550 nm emissions is measured. This is one order of magnitude lower than that previously reported for ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) microspheres. Optical bistability effects in ZBNA microspheres are reported and the bistable mechanism is discussed and attributed to shifts of the whispering gallery modes due to thermal expansion of the sphere, where heating is achieved by optical pumping around 978 nm. The effect of the bistability on the upconversion lasing is examined and we report multiple bistability loops within the microspheres.

  5. Fimbrial subunit protein FaeG expressed in transgenic tobacco inhibits the binding of F4ac enterotoxigenic Escherichia coli to porcine enterocytes.

    Science.gov (United States)

    Joensuu, Jussi J; Kotiaho, Mirkka; Riipi, Tero; Snoeck, Veerle; Palva, E Tapio; Teeri, Teemu H; Lång, Hannu; Cox, Eric; Goddeeris, Bruno M; Niklander-Teeri, Viola

    2004-06-01

    Plants offer a promising alternative for the production of foreign proteins for pharmaceutical purposes in tissues that are consumed as food and/or feed. Our long-term strategy is to develop edible vaccines against piglet diarrhoea caused by enterotoxigenic Escherichia coli (F4 ETEC) in feed plants. In this work, we isolated a gene, faeG, encoding for a major F4ac fimbrial subunit protein. Our goal was to test whether the FaeG protein, when isolated from its fimbrial background and produced in a plant cell, would retain the key properties of an oral vaccine, that is, stability in gastrointestinal conditions, binding to intestinal receptors and inhibition of the F4 ETEC attachment. For this purpose, tobacco was first transformed with a faeG construct that included a transit peptide encoding sequence to target the FaeG protein to the chloroplast. The best transgenic lines produced FaeG protein in amounts of 1% total soluble protein. The stability of the plant-produced FaeG was tested in fluids simulating piglet gastric (SGF) and intestinal (SIF) conditions. Plant-produced FaeG proved to be stable up to 2 h under these conditions. The binding and inhibition properties were tested with isolated piglet villi. These results showed that the plant-produced FaeG could bind to the receptors on the villi and subsequently inhibit F4 ETEC binding in a dose-dependent manner. Thus, the first two prerequisites for the development of an oral vaccine have been met.

  6. Thermodynamic Assessment of Hot Corrosion Mechanisms of Superalloys Hastelloy N and Haynes 242 in Eutectic Mixture of Molten Salts KF and ZrF4

    Energy Technology Data Exchange (ETDEWEB)

    Michael V. Glazoff

    2012-02-01

    The KF - ZrF4 system was considered for the application as a heat exchange agent in molten salt nuclear reactors (MSRs) beginning with the work carried out at ORNL in early fifties. Based on a combination of excellent properties such as thermal conductivity, viscosity in the molten state, and other thermo-physical and rheological properties, it was selected as one of possible candidates for the nuclear reactor secondary heat exchanger loop.

  7. TiF4 and NaF varnishes as anti-erosive agents on enamel and dentin erosion progression in vitro

    Directory of Open Access Journals (Sweden)

    Livia Picchi COMAR

    2015-02-01

    Full Text Available Objective This study assessed the effect of fluoride varnishes on the progression of tooth erosion in vitro. Material and Methods: Forty-eight enamel and 60 root dentin samples were previously demineralized (0.1% citric acid, pH 2.5, 30 min, leading to a baseline and erosive wear of 12.9 and 11.4 µm, respectively. The samples were randomly treated (6 h with a 4% TiF4 varnish (2.45%F-, pH 1.0, a 5.42% NaF varnish (2.45%F-, pH 5.0, a placebo varnish and no varnish (control. The samples were then subjected to erosive pH cycles (4x90 s/day in 0.1% citric acid, intercalated with artificial saliva for 5 days. The increment of the erosive tooth wear was calculated. In the case of dentin, this final measurement was done with and without the demineralized organic matrix (DOM. Enamel and dentin data were analyzed using ANOVA/Tukey’s and Kruskal-Wallis/Dunn tests, respectively (p<0.05. Results The TiF4 (mean±s.d: 1.5±1.1 µm and NaF (2.1±1.7 µm varnishes significantly reduced enamel wear progression compared to the placebo varnish (3.9±1.1 µm and control (4.5±0.9 µm. The same differences were found for dentin in the presence and absence of the DOM, respectively: TiF4 (average: 0.97/1.87 µm, NaF (1.03/2.13 µm, placebo varnish (3.53/4.47 µm and control (3.53/4.36 µm. Conclusion The TiF4 and NaF varnishes were equally effective in reducing the progression of tooth erosion in vitro.

  8. Efficacy of TiF4 and NaF varnish and solution: a randomized in situ study on enamel erosive-abrasive wear.

    Science.gov (United States)

    Levy, Flávia Mauad; Rios, Daniela; Buzalaf, Marília A R; Magalhães, Ana Carolina

    2014-05-01

    This in situ/ex vivo study analysed the anti-erosive/abrasive effect of TiF4 and NaF varnish and solution on enamel wear. Twelve subjects took part in this study which was performed in three periods (phases) with the duration of 5 days each. Each two human enamel specimens per subject were pretreated with experimental NaF varnish or solution (phase A), experimental-TiF4 varnish or solution (phase B) and placebo varnish or untreated control (phase C). The specimens were worn in palatal appliances; one enamel specimen, from each treatment, was subjected to erosion (ERO; cola soft drink, 4 × 90 s/day), and the other specimen was subjected to erosion plus abrasion (ERO + ABR; tooth brushing, 2 × 10 s/day). The tooth wear was quantified by a contact profilometer (micrometre) and analysed using two-way repeated measures ANOVA and Bonferroni's test (n = 12 subjects, p fluoride varnishes and solutions reduced the enamel wear (around 25 %) significantly compared to the control and placebo varnish. There were no significant differences among the fluoride formulations and between the conditions ERO and ERO + ABR. Therefore, it can be concluded that TiF4 has the same protective potential as NaF formulations to reduce human enamel wear under this experimental in situ model. In vitro studies have indicated a better anti-erosive/abrasive effect of TiF4 compared to NaF varnish. The present in situ study does not support the previous findings. Therefore, any of the tested professional fluoride varnishes in principle could be able to partially reduce enamel wear.

  9. Minimal unitary representation of 5d superconformal algebra F(4 and AdS6/CFT5 higher spin (super-algebras

    Directory of Open Access Journals (Sweden)

    Sudarshan Fernando

    2015-01-01

    Full Text Available We study the minimal unitary representation (minrep of SO(5,2, obtained by quantization of its geometric quasiconformal action, its deformations and supersymmetric extensions. The minrep of SO(5,2 describes a massless conformal scalar field in five dimensions and admits a unique “deformation” which describes a massless conformal spinor. Scalar and spinor minreps of SO(5,2 are the 5d analogs of Dirac's singletons of SO(3,2. We then construct the minimal unitary representation of the unique 5d superconformal algebra F(4 with the even subalgebra SO(5,2×SU(2. The minrep of F(4 describes a massless conformal supermultiplet consisting of two scalar and one spinor fields. We then extend our results to the construction of higher spin AdS6/CFT5 (super-algebras. The Joseph ideal of the minrep of SO(5,2 vanishes identically as operators and hence its enveloping algebra yields the AdS6/CFT5 bosonic higher spin algebra directly. The enveloping algebra of the spinor minrep defines a “deformed” higher spin algebra for which a deformed Joseph ideal vanishes identically as operators. These results are then extended to the construction of the unique higher spin AdS6/CFT5 superalgebra as the enveloping algebra of the minimal unitary realization of F(4 obtained by the quasiconformal methods.

  10. Exceptional F(4) Higher-Spin Theory in AdS(6) at One-Loop and other Tests of Duality

    CERN Document Server

    Gunaydin, Murat; Tran, Tung

    2016-01-01

    We study the higher-spin gauge theory in six-dimensional anti-de Sitter space $AdS_6$ that is based on the exceptional Lie superalgebra $F(4)$. The relevant higher-spin algebra was constructed in arXiv:1409.2185 [hep-th]. We determine the spectrum of the theory and show that it contains the physical fields of the Romans $F(4)$ gauged supergravity. The full spectrum consists of an infinite tower of unitary supermultiplets of $F(4)$ which extend the Romans multiplet to higher spins plus a single short supermultiplet. Motivated by applications to this novel supersymmetric higher-spin theory as well as to other theories, we extend the known one-loop tests of $AdS/CFT$ duality in various directions. The spectral zeta-function is derived for the most general case of fermionic and mixed-symmetry fields, which allows one to test the Type-A and B theories and supersymmetric extensions thereof in any dimension. We also study higher-spin doubletons and partially-massless fields. While most of the tests are successfully ...

  11. The virucidal effects against murine norovirus and feline calicivirus F4 as surrogates for human norovirus by the different additive concentrations of ethanol-based sanitizers.

    Science.gov (United States)

    Akasaka, Tempei; Shimizu-Onda, Yuko; Hayakawa, Satoshi; Ushijima, Hiroshi

    2016-03-01

    Since human norovirus is non-cultivable, murine norovirus and feline calicivirus have been used as surrogates. In this study, the virucidal effects of ethanol-based sanitizers with different concentrations of additives (malic acid/sodium malate, glycerin-fatty acid ester) against murine norovirus and feline calicivirus F4 were examined. The ethanol-based sanitizers at pH 7 showed sufficient virucidal effects, but glycerin-fatty acid ester included in ethanol-based sanitizers at pH 4 or 6 reduced the virucidal effects against murine norovirus. The ethanol-based sanitizers containing malic acid/sodium malate inactivated feline calicivirus F4 in shorter time, but there is no difference between ethanol-based sanitizers with and without glycerin-fatty acid ester. Traditionally, feline calicivirus has been used for long time as a surrogate virus for human norovirus. However, this study suggested that murine norovirus and feline calicivirus F4 had different sensitivity with the additive components of ethanol-based sanitizers. Therefore, using feline calicivirus alone as a surrogate for human norovirus may not be sufficient to evaluate the virucidal effect of sanitizers on food-borne infections caused by human norovirus. Sanitizers having virucidal effects against at least both murine norovirus and feline calicivirus may be more suitable to inactivate human norovirus.

  12. Synthesis of NaLuF4:Er3+, Yb3+, Ce3+ nanoparticles and study of photoluminescent properties in C - band

    Directory of Open Access Journals (Sweden)

    Khaydukov K.V.

    2017-01-01

    Full Text Available The novel core@shell nanocrystals β-NaLuF4@NaLuF4 co-doped with rare-earth ions Er3+, Yb3+, Ce3+ have been synthesized. The nano-particles indicate the intensive lines of anti-Stokes luminescence in the telecommunication С - band of spectrum when pumped at 970-980 nm. The nanoparticles have been characterized by transmission electron microscopy and spectrofluorimetry. The nanoparticles have a size 40-80 nm and possess the intensive photo-luminescence 73 nm bandwidth centered around 1530 nm. The photo-luminescence kinetics of β-NaLuF4: Er3+/ Yb3+/ Ce3+ has been studied in IR range of spectrum. We have demonstrated that doping with cerium ions prevents serial stepwise excitation of erbium ions. Consequently, the lifetime of transition in erbium 4I13/2→4I15/2 has risen up to 6.9 ms. Intensity of 1530 nm line in Er3+ ions excited at 980 nm has been increased up to 6 times. Therefore, the nanoparticles are applicable to fabrication of compact waveguide amplifiers for C - band.

  13. Paramagnetism and improved upconversion luminescence properties of NaYF4:Yb,Er/NaGdF4 nanocomposites synthesized by a boiling water seed-mediated route

    Science.gov (United States)

    Yang, Chao-Qing; Li, Ao-Ju; Guo, Wei; Tian, Peng-Hua; Yu, Xiao-Long; Liu, Zhong-Xin; Cao, Yang; Sun, Zhong-Liang

    2016-03-01

    In a route boiling water served as reaction medium, a stoichiometric amount of rare-earth compound and fluoride are put into this system to form α-NaYF4:Yb, Er nuclei. Then prepared sample is heated at elevated temperature to improve the fluorescence intensity, and next a NaGdF4 shell grows on the surface of NaYF4 nuclei. NaYF4:Yb,Er/NaGdF4 core-shell structured upconversion nanoparticles (CSUCNPs) have been successfully synthesized by above route. The use of boiling water decreases the cubic-to-hexagonal phase transition temperature of NaYF4:Yb,Er to 350°C and increases its upconversion (UC) luminescence intensity. A heterogeneous NaGdF4 epitaxially growing on the surface of Ln3+-doped NaYF4 not only improves UC luminescence, but also creates a paramagnetic shell, which can be used as contrast agents in magnetic resonance imaging (MRI). The solution of CSUCNPs shows bright green UC fluorescence under the excitation at 980 nm in a power density only about 50 mW·cm-2. A broad spectrum with a dominant resonance at g of about 2 is observed by the electron paramagnetic resonance (EPR) spectrum of CSUCNPs. Above properties suggest that the obtained CSUCNPs could be potential candidates for dual-mode optical/magnetic bioapplications.

  14. PEGylated NaHoF4 nanoparticles as contrast agents for both X-ray computed tomography and ultra-high field magnetic resonance imaging.

    Science.gov (United States)

    Ni, Dalong; Zhang, Jiawen; Bu, Wenbo; Zhang, Chen; Yao, Zhenwei; Xing, Huaiyong; Wang, Jing; Duan, Fei; Liu, Yanyan; Fan, Wenpei; Feng, Xiaoyuan; Shi, Jianlin

    2016-01-01

    It is well-known that multimodal imaging can integrate the advantages of different imaging modalities by overcoming their individual limitations. As ultra-high field magnetic resonance imaging (MRI) will be inevitably used in future MRI/X-ray computed tomography (CT) scanner, it is highly expected to develop high-performance nano-contrast agents for ultra-high field MR and CT dual-modality imaging, which has not been reported yet. Moreover, specific behavior of nano-contrast agents for ultra-high field MRI is a challenging work and still remains unknown. Herein, a novel type of NaHoF4 nanoparticles (NPs) with varied particle sizes were synthesized and explored as high-performance dual-modality contrast agents for ultra-high field MR and CT imaging. The specific X-ray absorption and MR relaxivity enhancements with varied nanoparticle diameters (3 nm, 7 nm, 13 nm and 29 nm) under different magnetic field (1.5/3.0/7.0 T) are investigated. Based on experimental results and theoretical analysis, the Curie and dipolar relaxation mechanisms of NaHoF4 NPs are firstly separated. Our results will greatly promote the future medical translational development of the NaHoF4 nano-contrast agents for ultra-high field MR/CT dual-modality imaging applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Exceptional F(4) higher-spin theory in AdS{sub 6} at one-loop and other tests of duality

    Energy Technology Data Exchange (ETDEWEB)

    Günaydin, Murat [Institute for Gravitation and the Cosmos Physics Department, Pennsylvania State University, University Park, PA 16802 (United States); Skvortsov, Evgeny [Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians University Munich, Theresienstr. 37, D-80333 Munich (Germany); Lebedev Institute of Physics, Leninsky ave. 53, 119991 Moscow (Russian Federation); Tran, Tung [Department of Physics, Brown University, Providence, Rhode Island 02912 (United States)

    2016-11-28

    We study the higher-spin gauge theory in six-dimensional anti-de Sitter space AdS{sub 6} that is based on the exceptional Lie superalgebra F(4). The relevant higher-spin algebra was constructed in http://arxiv.org/abs/1409.2185. We determine the spectrum of the theory and show that it contains the physical fields of the Romans F(4) gauged supergravity. The full spectrum consists of an infinite tower of unitary supermultiplets of F(4) which extend the Romans multiplet to higher spins plus a single short supermultiplet. Motivated by applications to this novel supersymmetric higher-spin theory as well as to other theories, we extend the known one-loop tests of AdS/CFT duality in various directions. The spectral zeta-function is derived for the most general case of fermionic and mixed-symmetry fields, which allows one to test the Type-A and B theories and supersymmetric extensions thereof in any dimension. We also study higher-spin doubletons and partially-massless fields. While most of the tests are successfully passed, the Type-B theory in all even dimensional anti-de Sitter spacetimes presents an interesting puzzle: the free energy as computed from the bulk is not equal to that of the free fermion on the CFT side, though there is some systematics to the discrepancy.

  16. Minimal unitary representation of 5d superconformal algebra F(4) and AdS{sub 6}/CFT{sub 5} higher spin (super)-algebras

    Energy Technology Data Exchange (ETDEWEB)

    Fernando, Sudarshan, E-mail: fernando@kutztown.edu [Physical Sciences Department, Kutztown University, Kutztown, PA 19530 (United States); Günaydin, Murat, E-mail: murat@phys.psu.edu [Institute for Gravitation and the Cosmos, Physics Department, Pennsylvania State University, University Park, PA 16802 (United States)

    2015-01-15

    We study the minimal unitary representation (minrep) of SO(5,2), obtained by quantization of its geometric quasiconformal action, its deformations and supersymmetric extensions. The minrep of SO(5,2) describes a massless conformal scalar field in five dimensions and admits a unique “deformation” which describes a massless conformal spinor. Scalar and spinor minreps of SO(5,2) are the 5d analogs of Dirac's singletons of SO(3,2). We then construct the minimal unitary representation of the unique 5d superconformal algebra F(4) with the even subalgebra SO(5,2)×SU(2). The minrep of F(4) describes a massless conformal supermultiplet consisting of two scalar and one spinor fields. We then extend our results to the construction of higher spin AdS{sub 6}/CFT{sub 5} (super)-algebras. The Joseph ideal of the minrep of SO(5,2) vanishes identically as operators and hence its enveloping algebra yields the AdS{sub 6}/CFT{sub 5} bosonic higher spin algebra directly. The enveloping algebra of the spinor minrep defines a “deformed” higher spin algebra for which a deformed Joseph ideal vanishes identically as operators. These results are then extended to the construction of the unique higher spin AdS{sub 6}/CFT{sub 5} superalgebra as the enveloping algebra of the minimal unitary realization of F(4) obtained by the quasiconformal methods.

  17. Tuning the morphology, luminescence and magnetic properties of hexagonal-phase NaGdF4: Yb, Er nanocrystals via altering the addition sequence of the precursors

    Science.gov (United States)

    Zhao, Shuwen; Xia, Donglin; Zhao, Ruimin; Zhu, Hao; Zhu, Yiru; Xiong, Yuda; Wang, Youfa

    2017-01-01

    Hexagonal-phase NaGdF4: Yb, Er upconversion nanocrystals (UCNCs) with tunable morphology and properties were successfully prepared via a thermal decomposition method. The influences of the adding sequence of the precursors on the morphology, chemical composition, luminescence and magnetic properties were investigated by transmission electron microscopy (TEM), inductively coupled plasma-atomic emission spectrometry (ICP-AES), upconversion (UC) spectroscopy, and a vibrating sample magnetometer (VSM). It was found that the resulting nanocrystals, with different sizes ranging from 24 to 224 nm, are in the shape of spheres, hexagonal plates and flakes; moreover, the composition percentage of Yb3+-Er3+ and Gd3+ ions was found to vary in a regular pattern with the adding sequence. Furthermore, the intensity ratios of emission colors (f g/r, f g/p), and the magnetic mass susceptibility of hexagonal-phase NaGdF4: Yb, Er nanocrystals change along with the composition of the nanocrystals. A positive correlation between the susceptibility and f g/r of NaGdF4: Yb, Er was proposed. The decomposition processes of the precursors were investigated by a thermogravimetric (TG) analyzer. The result indicated that the decomposition of the resolved lanthanide trifluoroacetate is greatly different from lanthanide trifluoroacetate powder. It is of tremendous help to recognize the decomposition process of the precursors and to understand the related reaction mechanism.

  18. Synthesis of Multicolor Core/Shell NaLuF4:Yb3+/Ln3+@CaF2 Upconversion Nanocrystals

    Directory of Open Access Journals (Sweden)

    Hui Li

    2017-02-01

    Full Text Available The ability to synthesize high-quality hierarchical core/shell nanocrystals from an efficient host lattice is important to realize efficacious photon upconversion for applications ranging from bioimaging to solar cells. Here, we describe a strategy to fabricate multicolor core @ shell α-NaLuF4:Yb3+/Ln3+@CaF2 (Ln = Er, Ho, Tm upconversion nanocrystals (UCNCs based on the newly established host lattice of sodium lutetium fluoride (NaLuF4. We exploited the liquid-solid-solution method to synthesize the NaLuF4 core of pure cubic phase and the thermal decomposition approach to expitaxially grow the calcium fluoride (CaF2 shell onto the core UCNCs, yielding cubic core/shell nanocrystals with a size of 15.6 ± 1.2 nm (the core ~9 ± 0.9 nm, the shell ~3.3 ± 0.3 nm. We showed that those core/shell UCNCs could emit activator-defined multicolor emissions up to about 772 times more efficient than the core nanocrystals due to effective suppression of surface-related quenching effects. Our results provide a new paradigm on heterogeneous core/shell structure for enhanced multicolor upconversion photoluminescence from colloidal nanocrystals.

  19. Investigation of energy shift of 4f3 and 4f5d levels in Nd-doped YLF and LLF crystals

    Directory of Open Access Journals (Sweden)

    André Felipe Henriques Librantz

    2006-01-01

    Full Text Available We observed ultraviolet (UV luminescence from 4f25d and 4f3 configuration in Nd-doped YLiF4 (YLF and LuLiF4 (LLF crystals induced by multiphotonic excitation of the three photons (532 nanometers [nm]. The LLF lattice is more compact than the YLF crystal and favours an absorption and emission shift of the main peaks due to crystal field strength. The red and blue shifts of the emission bands towards to lower (and higher energy are different for the transitions from 4f3 and 4f25d levels. The 4f3 transitions have smaller shift (~5 times smaller than the shift of the 4f25d due to 5s25p6 closed-shell shielding effect. On the other hand the 4f25d transitions are more susceptible to lattice change. The effect of the crystalline field was compared for both lattice. The result shows that these emission bands from 4f25d configuration always shift to lower energy when substituting the Y3+ by Lu3+ (i.e., the last one has the ionic radius 5% smaller than Y3+.

  20. Synthesis and characterization of a BaGdF5:Tb glass ceramic as a nanocomposite scintillator for x-ray imaging.

    Science.gov (United States)

    Lee, Gyuhyon; Struebing, Christian; Wagner, Brent; Summers, Christopher; Ding, Yong; Bryant, Alex; Thadhani, Naresh; Shedlock, Daniel; Star-Lack, Josh; Kang, Zhitao

    2016-05-20

    Transparent glass ceramics with embedded light-emitting nanocrystals show great potential as low-cost nanocomposite scintillators in comparison to single crystal and transparent ceramic scintillators. In this study, cubic structure BaGdF5:Tb nanocrystals embedded in an aluminosilicate glass matrix are reported for potential high performance MeV imaging applications. Scintillator samples with systematically varied compositions were prepared by a simple conventional melt-quenching method followed by annealing. Optical, structural and scintillation properties were characterized to guide the design and optimization of selected material systems, aiming at the development of a system with higher crystal volume and larger crystal size for improved luminosity. It is observed that enhanced scintillation performance was achieved by tuning the glass matrix composition and using GdF3 in the raw materials, which served as a nucleation agent. A 26% improvement in light output was observed from a BaGdF5:Tb glass ceramic with addition of GdF3.

  1. Two dimensional fluoride ion conductor RbSn {2}F {5} studied by impedance spectroscopy and {19}F, {119}Sn, and {87}Rb NMR

    Science.gov (United States)

    Yamada, K.; Ahmad, M. M.; Ogiso, Y.; Okuda, T.; Chikami, J.; Miehe, G.; Ehrenberg, H.; Fuess, H.

    2004-07-01

    RbSn2F5 is a two-dimensional fluoride ion conductor. It undergoes a first-order phase transition to a superionic state at 368 K. The structure of the low temperature phase has been determined from the Rietveld analysis of the X-ray powder diffraction. The dynamic properties of the fluoride ions in RbSn2F5 have been studied by impedance spectroscopy and solid state NMR. The dc ionic conductivity of this sample shows an abrupt increase at the phase transition temperature. We have obtained the hopping frequency and the concentration of the charge carriers (F- ions) at different temperatures from the analysis of the conductivity spectra using Almond-West formalism. The estimated values of the charge carriers’ concentration agree well with that determined from the structure and were found to be independent of temperature. The relatively small value of the power-law exponent, n ≈ 0.55, supports the two-dimensional property of the investigated material. Furthermore, 19F NMR with simulation has suggested the diffusive motions of the fluoride ions between different sites. In contrast, 119Sn and 87Rb NMR spectra below 250 K supported the intrinsic disordered nature due to the random distribution of the fluoride ion vacancies.

  2. Elaboration par procédé sol-gel de fluorures de type ALnF4 (A=Li, Na et Ln=Y, Gd) et de composites SiO2/LiGdF4 dopés par les ions de terres rares pour applications optiques

    OpenAIRE

    Lepoutre, Sophie

    2007-01-01

    This work is devoted to the development by the sol-gel process of ALnF4 (A=Li, Na and Ln=Y, Gd) fluorides and SiO2/LiGdF4 composites activated by Eu3+ ions. This synthesis process by a soft chemistry route, involving a sol as an intermediary step, enables the achievement of powders and coatings. The use of molecular precursors induces a homogeneous distribution of doping ions into the fluoride matrix avoiding any clustering effect. Several experimental tools (XRD, IR, Raman, EXAFS, NMR, EPR, ...

  3. Construction and Identification of Antibodies 2F5 and 4E10 Target Gene Vectors with the Neutralization of Anti-HIV Broad Spectrum%含抗HIV广谱中和抗体2F5、4E10靶基因载体的构建及鉴定

    Institute of Scientific and Technical Information of China (English)

    王晶妍; 张煜; 王珂; 王建英

    2012-01-01

    目的:构建含HIV gp120,gp41序列中广谱中和抗体2F5,4E10作用靶基因的载体并进行鉴定,为后期重组载体表达产物诱导产生中和抗体及抗HIV亚单位疫苗的研究奠定基础.方法:根据NCBI中HIV gp120,gp41基因序列中可与2F5、4E10结合的区域设计引物并进行PCR反应,将PCR得到的目的片段插入到载体pET28a中,对重组载体进行PCR鉴定、酶切鉴定及DNA测序.结果:PCR鉴定、酶切鉴定及DNA测序结果证实重组载体构建成功.结论:成功构建了含HIV gp120,gp41序列中广谱中和抗体2F5,4E10作用靶基因的载体.%Objective Antibodies 2F5 and 4E10 target gene vectors with the neutralization of anti-HIV broad spectrum were constructed and identified. This will certainly lay the foundation for future research of neutralizing antibodies from recom-binanl vector products in expression and induction and anti-HIV subunit vaccine. Method Primers were designed and PCR was conducted according to the binding region of the HIV gp120, gp41 gene sequences in NCBI and the 2F5 , 4E10. Then the target fragments from PCR were inserted into the vector pET28a. In the end. PCR, restriction enzyme digestion and DNA sequencing were performed for the recombinant vectors. The results; PCR, restriction enzyme digestion and DNA sequencing confirmed that the recombinant vector were successfully constructed. The conclusion; The construction of vectors of broad-spectrum neutralizing antibodies 2F5, 4E10 target genes containing HIV gp120. gp41 gene sequences was successfully conducted in this paper.

  4. Cytotoxic interactions of bare and coated NaGdF4:Yb(3+):Er(3+) nanoparticles with macrophage and fibroblast cells.

    Science.gov (United States)

    Wysokińska, E; Cichos, J; Zioło, E; Bednarkiewicz, A; Strządała, L; Karbowiak, M; Hreniak, D; Kałas, W

    2016-04-01

    The lanthanide nano-compounds are well suited to serve as fluorescent and magnetic contrast agents and luminescent labels. Although they are considered as promising materials for bio-imaging and bio-sensors in vivo or in vitro, the amount of data is still insufficient for deep understanding the toxicity of these nanomaterials. This knowledge is of great importance in the light of growing use of the biofunctionalized nanoparticles, which raises some questions about safety of these materials. Despite lanthanide-doped NaGdF4 nanocrystals are considered as non-toxic, here we present the data showing the fatal effect of newly synthetized NaGdF4:Yb(3+):Er(3+) on chosen types of cells. Our studies were performed on two cell lines NIH3T3 fibroblasts, and RAW264.7 macrophages. Cytotoxic properties of NaGdF4:Yb(3+):Er(3+) nanoparticles and their biological effects were studied by assessing cell culture viability (MTS), proliferation and apoptosis. Bare NaGdF4:Yb(3+):Er(3+) nanocrystals were cytotoxic and induced apoptosis of both NIH3T3 and RAW264.7 cells. Their cytotoxicity was reduced by PEGylation, at the expense of minimizing direct interactions between the compound and the cell. On the other hand, coating with silica reduced cell death induced by Yb(3+):Er(3+) codoped NaGdF4 nanocrystals (but proliferation was still inhibited). The NH2-modified silica coated nanoparticles were clearly less cytotoxic than pristine nanoparticles, which suggests that both, silica and PEG coatings are reasonable approaches to decrease cytotoxicity of the nanocrystal labels. The silica and PEG shell, should also enable and simplify further bio-functionalization of these luminescent labels. The authors acknowledge the financial support from: Institute of Immunology and Experimental Therapy, Polish Academy of Sciences (IITD PAN) grant no. 3/15, Polish Ministry of Science and Higher Education, Grant N N507 499538 and from the Wroclaw Research Centre EIT+ within the project "The Application of

  5. Influence of oxide and alloy formation on the Electrochemistry of Ti deposition from the NaCl-KCl-NaF-K-2 TiF6 melt reduced by metallic Ti

    DEFF Research Database (Denmark)

    Barner, Jens H. Von; Precht Noyé, Pernille; Barhoun, A

    2005-01-01

    The redox reactions in KCl-NaCl-NaF-K2TiF6 melts reduced by titanium metal have been studied by cyclic voltammetry and chronopotentiommetry. At platinum and nickel electrodes waves due to alloy formation were seen preceding the Ti(III) --> Ti metal deposition wave. The presence of oxide species...

  6. 10BaF2∶NaF, Na3AlF6/TiO2 composite as a novel visible-light-driven photocatalyst based on upconversion emission

    Institute of Scientific and Technical Information of China (English)

    Liu En-Zhou; Fan Jun; Hu Xiao-Yun; Hou Wen-Qian; Dai Hong-Zhe

    2012-01-01

    A rare-earth free upconversion luminescent material,10BaF2∶NaF,Na3AlF6,is synthesized by a hydrothermal method.The study of fluorescent spectrum indicates that it can convert visible light (550 nm-610 nm) into ultraviolet light (290 nm-350 nm),and two emission peaks at 304 nm and 324 nm are observed under the excitation of 583 nm at room temperature.Subsequently,10BaF2∶NaF,Na3AlF6/TiO2 composite photocatalyst is prepared and its catalyticactivity is evaluated by the photocatalytic reduction of CO2 under visible light irradiation (λ > 515 nm).The resultsshow that 10BaF2∶NaF,Na3AlF6/TiO2 is a more effective photocatalyst for CO2 reduction than pure TiO2,their corresponding methanol yields are 179 and 0 μmol/g-cat under the same conditions.Additionally,the mechanism of photocatalytic reduction of CO2 on 10BaF2∶NaF,Na3A1F6/TiO2 is proposed.

  7. Basic Fibroblast Growth Factor-Mediated Overexpression of Vascular Endothelial Growth Factor in 1F6 Human Melanoma Cells is Regulated by Activation of PI-3K and p38 MAPK

    Directory of Open Access Journals (Sweden)

    Dennis Fontijn

    2009-01-01

    Full Text Available Background: 1F6 human melanoma xenografts overexpressing either the 18 kD (18kD form or all (ALL forms of human basic fibroblast growth factor (bFGF demonstrate an abundant number of microvessels and accelerated growth. We now examined whether bFGF mediates vascular endothelial growth factor (VEGF expression.

  8. 锦屏一级水电站f5断层、煌斑岩脉复合灌浆技术研究%ANALYSIS OF COMPOUND GROUTING TECHNOLOGY FOR F5 FAULT AND LAMPROPHYRE VEIN AT JINPING Ⅰ HYDROPOWER

    Institute of Scientific and Technical Information of China (English)

    王胜; 黄润秋; 祝华平

    2012-01-01

    锦屏一级水电站发育的f5断层和煌斑岩脉对坝基的变形稳定、基础应力传递等极为不利,严重影响大坝稳定性及安全运营.针对f5断层、煌斑岩脉水泥灌浆存在的问题,结合f5断层和煌斑岩脉工程地质特征,开展f5断层、煌斑岩脉的水泥-化学复合灌浆加固技术研究.首先,对水泥-化学复合灌浆的作用机理进行分析,从灌浆材料、灌浆方法、现场灌浆试验、灌浆效果评价等方面进行了分析研究.研究结果表明,所采用灌浆材料可灌性较好,施工工艺、灌浆参数基本合理;灌浆后岩体透水性得到了改善,对f5断层、煌斑岩脉声波波速、变形模量等有一定程度提高,但仍然没有达到设计要求.基于水泥-化学复合灌浆存在的问题,分别从灌浆材料、灌浆参数和灌浆质量检查等方面提出了优化建议.%The f5 fault and lamprophyre vein of Jinping I Hydropower have an adverse effect to deformation stabil-ity and stress transfer of dam foundation. They can seriously affect the stability and safe operation of the dam. This paper investigates the cement grout problems for the f5 fault and lamprophyre vein. It is combined with its engineer-ing geology. It examines the cement-chemical compound grouting technology from grouting materials, grouting method, and field grouting. It evaluates the grouting on the basis of mechanism of cement-chemical compound grou-ting. The results show that the use of grouting materials can be better irrigation. Construction technology and grou-ting parameters are reasonable. The permeability of rock has been improved. The wave velocity and deformation modulus of the f5 fault and lamprophyre have a certain degree of improvement. But they still do not meet the design requirements. Optimization proposal has been got from grouting materials, parameters and quality checks on the ba-sis of the grouting evaluation results.

  9. Formation and spectral probing of transparent oxyfluoride glass-ceramics containing (Eu2+, Eu3+:BaGdF5) nano-crystals

    Science.gov (United States)

    Biswas, Kaushik; Balaji, S.; Karmakar, Prantik; Annapurna, K.

    2015-01-01

    In the present study, we report the formation of transparent glass-ceramics containing BaGdF5 nanocrystals under optimum ceramization of SiO2-BaF2-K2O-Sb2O3-GdF3-Eu2O3 based oxyfluoride glass and the energy transfer mechanisms in Eu2+ → Eu3+ and Gd3+ → Eu3+ has been interpreted through luminescence study. The modification of local environment surrounding dopant ion in glass and glass ceramics has been studied using Eu3+ ion as spectral probe. The optimum ceramization temperature was determined from the differential scanning calorimetry (DSC) thermogram which revealed that the glass transition temperature (Tg), the crystallization onset temperature (Tx), and crystallization peak temperature (Tp) are 563 °C, 607 °C and 641 °C, respectively. X-ray diffraction pattern of the glass-ceramics sample displayed the presence of cubic BaGdF5 phase (JCPDS code: 24-0098). Transmission electron microscopy image of the glass-ceramics samples revealed homogeneous distribution of spherical fluoride nanocrystals ranging 5-15 nm in size. The emission transitions from the higher excited sates (5DJ, J = 1, 2, and 3) as well as lowered asymmetry ratio of the 5D0 → 7F2 transition (forced electric dipole transition) to that of the 5D0 → 7F1 transition (magnetic dipole) of Eu3+ in the glass-ceramics when compared to glass sample demonstrated the incorporation of dopant Eu3+ ions into the cubic BaGdF5 nanocrystals with higher local symmetry with enhanced ionic nature. The presence of absorption bands of Eu2+ ions and Gd3+ ions present in the glass matrix or fluoride nanocrystals in the excitation spectra of Eu3+ by monitoring emission at 614 nm indicated energy transfer from (Eu2+ → Eu3+) and (Gd3+ → Eu3+) in both glass and glass-ceramics samples.

  10. 晶型和形貌对NaDyF4在1.06μm激光吸收能力的影响%Effects of crystal structure and shape on the 1.06 μm laser absorbability of NaDyF4

    Institute of Scientific and Technical Information of China (English)

    周健; 倪亚茹; 张文妍; 陆春华

    2011-01-01

    NaDyF4 micro-/nano-crystals were synthesized by hydrothermal method with oleic acid and EDTA-2Na as complexing agent. The crystal structure, crystal shape and diffused reflectance absorption spectra of the micro-/nano-crystals were characterized with X-ray diffractometer (XRD), scanning electron microscopy (SEM) and UV-VIS-NIR spectrophotometer (UVPC), and the effects of crystal structure, crystal shape and length/diameter ratio on the near-1.06 um laser absorption behavior of the micro-/nano-crystals were discussed. The results show that, compared with cubic phase NaDyF4, the absorption peak of pure hexagonal phase NaDyF4 blueshifts 0.008 μm to 1.078 μm in the wavelength range of 1.05 to 1.15 μm. When the shapes of NaDyF4 micro-/nano-crystals change from rod to prism and to tube, the characteristic absorption peak of Dy3+ shows buleshift. The NaDyF4 micro-/nano-crystals sample with hexagonal phase, tube shape and larger length/diameter ratio exhibit better absorption properties in comparison to other samples.%采用水热法,以油酸和EDTA-2Na为络合剂,合成了NaDyF4微纳米晶。利用X射线衍射(XRD)仪、扫描电子显微镜(SEM)和紫外-可见分光光度计(UVPC)对产物的晶型结构、形貌和漫反射吸收光谱进行了表征,讨论了晶型和形貌变化以及不同长径比等对产物在1.06μm波长附近光谱吸收性能的影响。结果表明,在1.05~1.15 μm波长范围内,六方相较立方相NaDyF4的吸收峰位置蓝移了0.008 μm至1.078 μm附近,随着产物的形貌由短棒状变成六棱柱状和管状,Dy3+的特征吸收峰相继发生蓝移。六方相,管状,长径比较大的产物吸收性能较好。

  11. The i11/2 f5/2 and i11/2 p3/2 neutron particle-hole multiplets in 208Pb

    CERN Document Server

    Heusler, A; Graw, G; Hertenberger, R; Jolie, J; Krücken, R; Pietralla, N; Riess, F; Von Brentano, P; Wirth, H F

    2006-01-01

    Inelastic proton scattering via isobaric analog resonances allows to derive rather complete information about neutron particle-hole states. We applied this method to the doubly-magic nucleus 208Pb by measuring angular distributions of 208Pb(p, p') on top of the isobaric analog resonances in 209Bi with the Q3D magnetic spectrograph at M\\"unchen. We identify the six states of the i11/2 f5/2 multiplet and the four states of the i11/2 p3/2 multiplet in the energy range 4.6 MeV < Ex < 5.3 MeV. Firm spin assignments for the ten states are given, some of them new. Additional measurements of the reaction 207Pb(d, p) confirm the fragmented i11/2 p1/2 multiplet.

  12. Analysis of the 3d6 4s(6D)4f-5g supermultiplet of Fe I in laboratory and solar infrared spectra. johansson

    CERN Document Server

    Nave, G; Sauval, A J; Grevesse, N; Schönfeld, W G; Chang, E S; Apj, C B F

    1994-01-01

    The combined laboratory and solar analysis of the highly-excited subconfigurations 4f and 5g of Fe I has allowed us to classify 87 lines of the 4f-5g supermultiplet in the spectral region 2545-2585 cm-1. The level structure of these JK-coupled configurations is predicted by semiempirical calculations and the quadrupolic approximation. Semiempirical gf-values have been calculated and are compared to gf values derived from the solar spectrum. The solar analysis has shown that these lines, which should be much less sensitive than lower excitation lines to departures from LTE and to temperature uncertainties, lead to a solar abundance of iron which is consistent with the meteoritic value (A_Fe = 7.51).

  13. Preparation and characterization of PVC/PMMA blend polymer electrolytes complexed with LiN(C2F5SO22

    Directory of Open Access Journals (Sweden)

    R. Nimma Elizabeth

    2004-03-01

    Full Text Available Thin films of polymer blend electrolytes comprising Poly(vinyl chloride (PVC and Poly(methyl methacrylate(PMMA and plasticized with a combination of ethylene carbonate (EC and propylene carbonate (PC for different lithium imide salt, LiN(C2F5SO32 , concentrations were prepared using the solution casting technique. The films were subjected to a. c. impedance measurements as a function of temperature ranging from -30 °C to 70 °C. The variation of ionic conductivity as a function of temperature and PVC content in the blend was analysed. The role of PMMA in the phenomena occurring at the interface between the plasticized polymer electrolyte and lithium electrode was also studied. The cast films were also subjected to TG/DTA and FT-IR studies which are discussed.

  14. The F4/AS01B HIV-1 Vaccine Candidate Is Safe and Immunogenic, But Does Not Show Viral Efficacy in Antiretroviral Therapy-Naive, HIV-1-Infected Adults

    Science.gov (United States)

    Dinges, Warren; Girard, Pierre-Marie; Podzamczer, Daniel; Brockmeyer, Norbert H.; García, Felipe.; Harrer, Thomas; Lelievre, Jean-Daniel; Frank, Ian; Colin De Verdière, Nathalie; Yeni, Guy-Patrick; Ortega Gonzalez, Enrique; Rubio, Rafael; Clotet Sala, Bonaventura; DeJesus, Edwin; Pérez-Elias, Maria Jesus; Launay, Odile; Pialoux, Gilles; Slim, Jihad; Weiss, Laurence; Bouchaud, Olivier; Felizarta, Franco; Meurer, Anja; Raffi, François; Esser, Stefan; Katlama, Christine; Koletar, Susan L.; Mounzer, Karam; Swindells, Susan; Baxter, John D.; Schneider, Stefan; Chas, Julie; Molina, Jean-Michel; Koutsoukos, Marguerite; Collard, Alix; Bourguignon, Patricia; Roman, François

    2016-01-01

    Abstract The impact of the investigational human immunodeficiency virus type 1 (HIV-1) F4/AS01B vaccine on HIV-1 viral load (VL) was evaluated in antiretroviral therapy (ART)-naive HIV-1 infected adults. This phase IIb, observer-blind study (NCT01218113), included ART-naive HIV-1 infected adults aged 18 to 55 years. Participants were randomized to receive 2 (F4/AS01B_2 group, N = 64) or 3 (F4/AS01B_3 group, N = 62) doses of F4/AS01B or placebo (control group, N = 64) at weeks 0, 4, and 28. Efficacy (HIV-1 VL, CD4+ T-cell count, ART initiation, and HIV-related clinical events), safety, and immunogenicity (antibody and T-cell responses) were evaluated during 48 weeks. At week 48, based on a mixed model, no statistically significant difference in HIV-1 VL change from baseline was demonstrated between F4/AS01B_2 and control group (0.073 log10 copies/mL [97.5% confidence interval (CI): −0.088; 0.235]), or F4/AS01B_3 and control group (−0.096 log10 copies/mL [97.5% CI: −0.257; 0.065]). No differences between groups were observed in HIV-1 VL change, CD4+ T-cell count, ART initiation, or HIV-related clinical events at intermediate timepoints. Among F4/AS01B recipients, the most frequent solicited symptoms were pain at injection site (252/300 doses), fatigue (137/300 doses), myalgia (105/300 doses), and headache (90/300 doses). Twelve serious adverse events were reported in 6 participants; 1 was considered vaccine-related (F4/AS01B_2 group: angioedema). F4/AS01B induced polyfunctional F4-specific CD4+ T-cells, but had no significant impact on F4-specific CD8+ T-cell and anti-F4 antibody levels. F4/AS01B had a clinically acceptable safety profile, induced F4-specific CD4+ T-cell responses, but did not reduce HIV-1 VL, impact CD4+ T-cells count, delay ART initiation, or prevent HIV-1 related clinical events. PMID:26871794

  15. Identification and functional characterization of a putative IDE, C28F5.4 (ceIDE-1), in Caenorhabditis elegans: Implications for Alzheimer's disease.

    Science.gov (United States)

    Haque, Rizwanul; Nazir, Aamir

    2016-11-01

    Insulin-degrading enzyme (IDE) is a zinc metalloprotease, known to degrade insulin peptide and amyloid-beta (Aβ); the key protein involved in Alzheimer's disease (AD). Considering the important role played by IDE in disease progression of AD and type 2 diabetes mellitus (T2DM), we endeavored to identify the Caenorhabditis elegans (C. elegans) IDE orthologous genes and test them for their role in AD related outcomes. We employed bioinformatics, reverse genetics and molecular biology approaches towards identification and functional characterization of putative IDE candidates in C. elegans. Using in-silico analysis we have identified seven C. elegans genes that possess HXXEH motif, an identifying marker of IDE. We further carried out functional analysis of the identified genes in Aβ expressing C. elegans strain CL4176 [myo-3/Aβ1-42 long 3'-UTR] via studying effect on Aβ induced toxicity, cholinergic neuroanatomy, content of acetylcholine/acetylcholine-esterase, extent of reactive oxygen species and expression of FOXO transcription factor DAF-16. Our findings reveal that amongst the identified putative IDE orthologs, a functionally uncharacterized gene C28F5.4 had a profound effect on the tested endpoints. Knocking down C28F5.4 modulated the AD associated conditions by decreasing Aβ induced toxicity, severely compromising cholinergic neuroanatomy, reducing expression of acetylcholine-transporter, decreasing acetylcholine content, elevating ROS, with no effect on DAF-16 stress-response protein. These studies provide crucial insight into the structural/functional orthology of IDEs across human and nematode species and further our understanding of the involvement of these proteins and insulin pathway in AD. Further studies could aid in identifying novel drug-targets and in understanding the common modulating factors between AD and T2DM.

  16. Isolation and structural elucidation of the antibacterial metabolites produced by marine-derived Aspergillus strain F5%海洋曲霉属真菌菌株F5抑菌活性代谢产物的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    李莹; 李进军; 王辂; 叶波平

    2013-01-01

    Objective To identify and purify the antibacterial metabolites from the fermentation broth of Aspergillus sp. F5, isolated from the rhizospheric soil of Bruguiera gymnorrhiza, Guangdong. Methods Fermentation broth was extracted with acetic ether, then the extraction was separated and purified by silica gel, Sephadex LH20 and RP-18 colunm chromatography. Their structures were elucidated by means of spectral analysis including ESI-MS, 1H-NMR and 13C-NMR. Their antibacterial activity were detected with Alamar-Blue method. Results Five compounds were separated and purified from the acetic ether extraction of this Aspergillus strain, two lactones, two isocoumarin compounds and a unsaturated acid. Their structures were elucidated as (1) Asperlactone, (2) Aspyrone, (3) Penicillic acid, (4) cis-4-hydroxymellein and (5) frart.s-4-hydroxymellein by spectroscopic analysis(ESI-MS> 1H-NMR and 13C-NMR), among which compound 4 showed apparently antifungal activity against the growth of Candida albicans in the final concentration of 50μg/mL. Conclusion Strain F5 secretes cw-4-hydroxymellein(4) which effectively inhibits the growth of Candida albicans.%目的 从一株分离自广东湛江特呈岛木榄根际土壤的曲霉属真菌F5的发酵液中分离抑菌活性次级代谢产物.方法 发酵液经乙酸乙酯萃取、正相硅胶柱层析、分子筛层析、C18柱制备色谱分离获得单体,并对化合物进行结构鉴定及活性测试.结果 从菌株F5的乙酸乙酯提取物中分离得到2个内酯、2个异香豆素类化合物和1个不饱和酸,根据化合物的谱学特征(ESI-MS、1H-NMR和13C-NMR)和理化性质分别鉴定为(1)asperlactone、(2)aspyrone、(3)penicillic acid、(4)cis-4-hydro xymellein和(5)trans-4-hydroxymellein.其中化合物4在终浓度50μg/mL时,对Candida albicans有抑制作用.结论 菌株F5分泌的代谢产物cis-4-hydroxymellein(4)对Candida albicans有明显抑制作用.

  17. Magnetic/upconversion fluorescent NaGdF4:Yb,Er nanoparticle-based dual-modal molecular probes for imaging tiny tumors in vivo.

    Science.gov (United States)

    Liu, Chunyan; Gao, Zhenyu; Zeng, Jianfeng; Hou, Yi; Fang, Fang; Li, Yilin; Qiao, Ruirui; Shen, Lin; Lei, Hao; Yang, Wensheng; Gao, Mingyuan

    2013-08-27

    Detection of early malignant tumors remains clinically difficult; developing ultrasensitive imaging agents is therefore highly demanded. Owing to the unusual magnetic and optical properties associated with f-electrons, rare-earth elements are very suitable for creating functional materials potentially useful for tumor imaging. Nanometer-sized particles offer such a platform with which versatile unique properties of the rare-earth elements can be integrated. Yet the development of rare-earth nanoparticle-based tumor probes suitable for imaging tiny tumors in vivo remains difficult, which challenges not only the physical properties of the nanoparticles but also the rationality of the probe design. Here we report new approaches for size control synthesis of magnetic/upconversion fluorescent NaGdF4:Yb,Er nanocrystals and their applications for imaging tiny tumors in vivo. By independently varying F(-):Ln(3+) and Na(+):Ln(3+) ratios, the size and shape regulation mechanisms were investigated. By replacing the oleic acid ligand with PEG2000 bearing a maleimide group at one end and two phosphate groups at the other end, PEGylated NaGdF4:Yb,Er nanoparticles with optimized size and upconversion fluorescence were obtained. Accordingly, a dual-modality molecular tumor probe was prepared, as a proof of concept, by covalently attaching antitumor antibody to PEGylated NaGdF4:Yb,Er nanoparticles through a "click" reaction. Systematic investigations on tumor detections, through magnetic resonance imaging and upconversion fluorescence imaging, were carried out to image intraperitoneal tumors and subcutaneous tumors in vivo. Owing to the excellent properties of the molecular probes, tumors smaller than 2 mm was successfully imaged in vivo. In addition, pharmacokinetic studies on differently sized particles were performed to disclose the particle size dependent biodistributions and elimination pathways.

  18. Mass Spectrometric Investigation of Silicon Extremely Enriched in (28)Si: From (28)SiF4 (Gas Phase IRMS) to (28)Si Crystals (MC-ICP-MS).

    Science.gov (United States)

    Pramann, Axel; Rienitz, Olaf

    2016-06-01

    A new generation of silicon crystals even further enriched in (28)Si (x((28)Si) > 0.999 98 mol/mol), recently produced by companies and institutes in Russia within the framework of a project initiated by PTB, were investigated with respect to their isotopic composition and molar mass M(Si). A modified isotope dilution mass spectrometric (IDMS) method treating the silicon as the matrix containing a so-called virtual element (VE) existing of the isotopes (29)Si and (30)Si solely and high resolution multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) were applied in combination. This method succeeds also when examining the new materials holding merely trace amounts of (29)Si (x((29)Si) ≈ 5 × 10(-6) mol/mol) and (30)Si (x((30)Si) ≈ 7 × 10(-7) mol/mol) extremely difficult to detect with lowest uncertainty. However, there is a need for validating the enrichment in (28)Si already in the precursor material of the final crystals, silicon tetrafluoride (SiF4) gas prior to crystal production. For that purpose, the isotopic composition of selected SiF4 samples was determined using a multicollector magnetic sector field gas-phase isotope ratio mass spectrometer. Contaminations of SiF4 by natural silicon due to storing and during the isotope ratio mass spectrometry (IRMS) measurements were observed and quantified. The respective MC-ICP-MS measurements of the corresponding crystal samples show-in contrast-several advantages compared to gas phase IRMS. M(Si) of the new crystals were determined to some extent with uncertainties urel(M) Si)) on the degree of enrichment in (28)Si. This leads to a reduction of urel(M(Si)) during the past decade by almost 3 orders of magnitude and thus further reduces the uncertainty of the Avogadro constant NA which is one of the preconditions for the redefinition of the SI unit kilogram.

  19. Tumor development in murine ulcerative colitis depends on MyD88 signaling of colonic F4/80+CD11bhighGr1low macrophages

    Science.gov (United States)

    Schiechl, Gabriela; Bauer, Bernhard; Fuss, Ivan; Lang, Sven A.; Moser, Christian; Ruemmele, Petra; Rose-John, Stefan; Neurath, Markus F.; Geissler, Edward K.; Schlitt, Hans-Jürgen; Strober, Warren; Fichtner-Feigl, Stefan

    2011-01-01

    Patients with prolonged ulcerative colitis (UC) frequently develop colorectal adenocarcinoma for reasons that are not fully clear. To analyze inflammation-associated colonic tumorigenesis, we developed a chronic form of oxazolone-induced colitis in mice that, similar to UC, was distinguished by the presence of IL-13–producing NKT cells. In this model, the induction of tumors using azoxymethane was accompanied by the coappearance of F4/80+CD11bhighGr1low M2 macrophages, cells that undergo polarization by IL-13 and are absent in tumors that lack high level IL-13 production. Importantly, this subset of macrophages was a source of tumor-promoting factors, including IL-6. Similar to dextran sodium sulfate–induced colitis, F4/80+CD11bhighGr1intermediate macrophages were present in the mouse model of chronic oxazolone-induced colitis and may influence tumor development through production of TGF-β1, a cytokine that inhibits tumor immunosurveillance. Finally, while robust chronic oxazolone-induced colitis developed in myeloid differentiation primary response gene 88–deficient (Myd88–/–) mice, these mice did not support tumor development. The inhibition of tumor development in Myd88–/– mice correlated with cessation of IL-6 and TGF-β1 production by M2 and F4/80+CD11bhighGr1intermediate macrophages, respectively, and was reversed by exogenous IL-6. These data show that an UC-like inflammation may facilitate tumor development by providing a milieu favoring development of MyD88-dependent tumor-supporting macrophages. PMID:21519141

  20. Asymmetric Hollow Fiber Membranes for Separation of CO 2 from Hydrocarbons and Fluorocarbons at High-Pressure Conditions Relevant to C 2 F 4 Polymerization

    KAUST Repository

    Kosuri, Madhava R.

    2009-12-02

    Separation of high-pressure carbon dioxide from fluorocarbons is important for the production of fluoropolymers such as poly(tetrafluoroethylene). Typical polymeric membranes plasticize under high CO2 partial pressure conditions and fail to provide adequate selective separations. Torlon, a polyamide-imide polymer, with the ability to form interchain hydrogen bonding, is shown to provide stability against aggressive CO2 plasticization. Torlon membranes in the form of asymmetric hollow fibers (the most productive form of membranes) are considered for an intended separation of CO 2/C2F4. To avoid safety issues with tetrafluoroethylene (C2F4), which could detonate under testing conditions, safer surrogate mixtures (C2H2F 2 and C2H4) are considered in this paper. Permeation measurements (at 35 °C) indicate that the Torlon membranes are not plasticized even up to 1250 psi of CO2. The membranes provide mixed gas CO2/C2H2F2 and CO 2/C2H4 selectivities of 100 and 30, respectively, at 1250 psi partial pressures of CO2. On the basis of the measured separation performances of CO2/C2H 2F2 and CO2/C2H4 mixtures, the selectivity of the CO2/C2F4 mixture is expected to be greater than 100. Long-term stability studies indicate that the membranes provide stable separations over a period of 5 days at 1250 psi partial pressures of CO2, thereby making the membrane approach attractive. © 2009 American Chemical Society.

  1. Volcanic SO2 and SiF4 visualization using 2-D thermal emission spectroscopy – Part 1: Slant-columns and their ratios

    Directory of Open Access Journals (Sweden)

    M. Grutter

    2012-02-01

    Full Text Available The composition and emission rates of volcanic gas plumes provide insight of the geologic internal activity, atmospheric chemistry, aerosol formation and radiative processes around it. Observations are necessary for public security and the aviation industry. Ground-based thermal emission infrared spectroscopy, which uses the radiation of the volcanic gas itself, allows for continuously monitoring during day and night from a safe distance. We present measurements on Popocatépetl volcano based on thermal emission spectroscopy during different campaigns between 2006–2009 using a Scanning Infrared Gas Imaging System (SIGIS. The experimental set-up, measurement geometries and analytical algorithms are described. The equipment was operated from a safe distance of 12 km from the volcano at two different spectral resolutions: 0.5 and 4 cm−1. The 2-dimensional scanning capability of the instrument allows for an on-line visualization of the volcanic SO2 plume and its animation. SiF4 was also identified in the infrared spectra recorded at both resolutions. The SiF4/SO2 molecular ratio can be calculated from each image and used as a highly useful parameter to follow changes in volcanic activity. A small Vulcanian eruption was monitored during the night of 16 to 17 November 2008 and strong ash emission together with a pronounced SO2 cloud was registered around 01:00 a.m. LST (Local Standard Time. Enhanced SiF4/SO2 ratios were observed before and after the eruption. A validation of the results from thermal emission measurements with those from absorption spectra of the moon taken at the same time, as well as an error analysis, are presented. The inferred propagation speed from sequential images is used in a subsequent paper (Part 2 to calculate the emission rates at different distances from the crater.

  2. TiF4 and NaF varnishes as anti-erosive agents on enamel and dentin erosion progression in vitro

    Science.gov (United States)

    COMAR, Livia Picchi; CARDOSO, Cristiane de Almeida Baldini; CHARONE, Senda; GRIZZO, Larissa Tercilia; BUZALAF, Marília Afonso Rabelo; MAGALHÃES, Ana Carolina

    2015-01-01

    Objective This study assessed the effect of fluoride varnishes on the progression of tooth erosion in vitro. Material and Methods: Forty-eight enamel and 60 root dentin samples were previously demineralized (0.1% citric acid, pH 2.5, 30 min), leading to a baseline and erosive wear of 12.9 and 11.4 µm, respectively. The samples were randomly treated (6 h) with a 4% TiF4 varnish (2.45%F-, pH 1.0), a 5.42% NaF varnish (2.45%F-, pH 5.0), a placebo varnish and no varnish (control). The samples were then subjected to erosive pH cycles (4x90 s/day in 0.1% citric acid, intercalated with artificial saliva) for 5 days. The increment of the erosive tooth wear was calculated. In the case of dentin, this final measurement was done with and without the demineralized organic matrix (DOM). Enamel and dentin data were analyzed using ANOVA/Tukey’s and Kruskal-Wallis/Dunn tests, respectively (pvarnishes significantly reduced enamel wear progression compared to the placebo varnish (3.9±1.1 µm) and control (4.5±0.9 µm). The same differences were found for dentin in the presence and absence of the DOM, respectively: TiF4 (average: 0.97/1.87 µm), NaF (1.03/2.13 µm), placebo varnish (3.53/4.47 µm) and control (3.53/4.36 µm). Conclusion The TiF4 and NaF varnishes were equally effective in reducing the progression of tooth erosion in vitro. PMID:25760263

  3. Volcanic SO2 and SiF4 visualization using 2-D thermal emission spectroscopy - Part 1: Slant-columns and their ratios

    Science.gov (United States)

    Stremme, W.; Krueger, A.; Harig, R.; Grutter, M.

    2012-02-01

    The composition and emission rates of volcanic gas plumes provide insight of the geologic internal activity, atmospheric chemistry, aerosol formation and radiative processes around it. Observations are necessary for public security and the aviation industry. Ground-based thermal emission infrared spectroscopy, which uses the radiation of the volcanic gas itself, allows for continuously monitoring during day and night from a safe distance. We present measurements on Popocatépetl volcano based on thermal emission spectroscopy during different campaigns between 2006-2009 using a Scanning Infrared Gas Imaging System (SIGIS). The experimental set-up, measurement geometries and analytical algorithms are described. The equipment was operated from a safe distance of 12 km from the volcano at two different spectral resolutions: 0.5 and 4 cm-1. The 2-dimensional scanning capability of the instrument allows for an on-line visualization of the volcanic SO2 plume and its animation. SiF4 was also identified in the infrared spectra recorded at both resolutions. The SiF4/SO2 molecular ratio can be calculated from each image and used as a highly useful parameter to follow changes in volcanic activity. A small Vulcanian eruption was monitored during the night of 16 to 17 November 2008 and strong ash emission together with a pronounced SO2 cloud was registered around 01:00 a.m. LST (Local Standard Time). Enhanced SiF4/SO2 ratios were observed before and after the eruption. A validation of the results from thermal emission measurements with those from absorption spectra of the moon taken at the same time, as well as an error analysis, are presented. The inferred propagation speed from sequential images is used in a subsequent paper (Part 2) to calculate the emission rates at different distances from the crater.

  4. RI/MOM renormalization constants (N_f=4) and the strong coupling constant (N_f=2+1+1) from twisted-mass QCD

    CERN Document Server

    Blossier, B; Brinet, M; De Soto, F; Du, X; Gravina, M; Liu, Z; Morenas, V; Pène, O; Petrov, K; Rodríguez-Quintero, J

    2011-01-01

    We study RI/MOM renormalization constants of bilinear quark operators for $N_f=4$ and the strong coupling constant for $N_f=2+1+1$ using Wilson twisted-mass fermions. We use the "egalitarian" method to remove H(4) hypercubic artifacts non-perturbatively, which enables us to study physical quantities in a wide range of momenta. We then apply OPE in studying the running behavior of $Z_q$ and $\\alpha_s$, from which we are able to extract the Landau gauge dimension-two gluon condensate $$ which is of phenomenological interest.

  5. Gut-Associated Lymphoid Tissue: A Key Tissue Inside the Mucosal Immune System of Hens Immunized with Escherichia coli F4

    Directory of Open Access Journals (Sweden)

    Maria F. Peralta

    2017-05-01

    Full Text Available Immunoglobulin Y (IgY is the predominant antibody found in hen’s (Gallus domesticus egg yolk. This antibody, developed against several microorganisms in hen egg yolk, has been successfully used as an alternative to immunoglobulins from mammals for use in immunodiagnostics and immunotherapy. Enteropathogenic Escherichia coli (E.coli F4 is the main etiological agent associated with swine neonatal diarrhea, and it causes notable economic losses in swine production. The aim of the present study was to evaluate the relationship between humoral immune response and the activation of gut-associated lymphoid tissue (GALT in laying hens intramuscularly immunized with E. coli F4. Adult laying Shaver hens were immunized with a bacterin based on an inactivated lysate E. coli F4 strain that was originally isolated from neonatal piglet diarrhea, following a recommended schedule. The percentage of B lymphocytes in blood and spleen homogenates was determined by flow cytometry. Villi histomorphometry and the size of germinal centers (GC activated in GALT and the spleen were measured in histological samples either stained with hematoxylin/eosin or through immunofluorescence. Antibody and isotype-specific antibodies in serum and egg yolk were measured using indirect enzyme-linked immunosorbent assay (ELISA. Secretory and serum immunoglobulin A (IgA were measured by ELISA tests. Laying hen with intramuscular immunization with E. coli F4 lysate, activated both mucosal and systemic protection. Mucosal protection was provided through B lymphocytes, and most of them were activated on Peyer’s patches and esophageal tonsils, in GALT. Furthermore, increased B lymphocyte number in the lamina propria of the gut, and increased intraepithelial plasmatic cell number, produced high levels of mucosal IgA. Activated B lymphocytes interacted with absorptive cells, immune cells, and microbiota in the gut, producing signals that were translated into a powerful physical defense by

  6. Random-field induced memory effects in inhomogeneously diluted antiferromagnets K2NixZn1−xF4

    DEFF Research Database (Denmark)

    Dikken, B. J.; Arts, A. F. M.; de Wijn, H. W.

    1986-01-01

    Using neutron diffraction a random-field generated memory is observed in K2NixZn1−xF4 with x = 0.96, 0.85, and 0.75. The intensities and profiles of magnetic Bragg reflections are found to follow unique trajectories determined by switching the external magnetic field on and off while cooling....... The effect, associated with a inhomogeneous spread in TN on a microscopic scale, is a direct manifestation of freezing in of multi-domain states at the ordering temperature....

  7. Sequence of the new Drosophila melanogaster small heat-shock-related gene, lethal(2) essential for life [l(2)efl], at locus 59F4,5.

    Science.gov (United States)

    Kurzik-Dumke, U; Lohmann, E

    1995-03-10

    In this study, we report the molecular cloning of a novel Drosophila melanogaster small heat-shock (HS)-homologous gene, l(2)efl, identified on the right arm of the second chromosome at locus 59F4,5. We describe the temporal expression of l(2)efl in the wild-type and present its structure. The deduced amino-acid sequence of the Efl protein shows significant homology to all known small HS proteins identified in Drosophila and vertebrates, and to mammalian alpha-crystallin.

  8. Molecular dynamics simulation of the thermodynamic and transport properties of the molten salt fast reactor fuel LiF-ThF4

    Science.gov (United States)

    Dewan, Leslie C.; Simon, Christian; Madden, Paul A.; Hobbs, Linn W.; Salanne, Mathieu

    2013-03-01

    The local structure and transport properties of molten LiF-ThF4 at the eutectic composition have been studied at a range of temperatures, using molecular dynamics simulations that incorporate dipole polarization effects. This polarizable interaction potential was parameterized from first-principles calculations. We have calculated the density, self-diffusion coefficients, electrical conductivity, viscosity, and heat capacity at a range of temperatures from 850 K to 1273 K. We have also examined the changes in coordination number as a function of temperature. The simulation results were in good agreement with available experimental data, indicating that such simulations can fulfill a valuable role in augmenting existing experimental work.

  9. Hydrothermal synthesis of NaLuF4:153Sm,Yb,Tm nanoparticles and their application in dual-modality upconversion luminescence and SPECT bioimaging.

    Science.gov (United States)

    Yang, Yang; Sun, Yun; Cao, Tianye; Peng, Juanjuan; Liu, Ying; Wu, Yongquan; Feng, Wei; Zhang, Yingjian; Li, Fuyou

    2013-01-01

    Upconversion luminescence (UCL) properties and radioactivity have been integrated into NaLuF(4):(153)Sm,Yb,Tm nanoparticles by a facile one-step hydrothermal method, making these nanoparticles potential candidates for UCL and single-photon emission computed tomography (SPECT) dual-modal bioimaging in vivo. The introduction of small amount of radioactive (153)Sm(3+) can hardly vary the upconversion luminescence properties of the nanoparticles. The as-designed nanoparticles showed very low cytotoxicity, no obvious tissue damage in 7 days, and excellent in vitro and in vivo performances in dual-modal bioimaging. By means of a combination of UCL and SPECT imaging in vivo, the distribution of the nanoparticles in living animals has been studied, and the results indicated that these particles were mainly accumulated in the liver and spleen. Therefore, the concept of (153)Sm(3+)/Yb(3+)/Tm(3+) co-doped NaLuF(4) nanoparticles for UCL and SPECT dual-modality imaging in vivo of whole-body animals may serve as a platform for next-generation probes for ultra-sensitive molecular imaging from the cellular scale to whole-body evaluation. It also introduces an easy methodology to quantify in vivo biodistribution of nanomaterials which still needs further understanding as a community.

  10. Increased number of intestinal villous M cells in levamisole -pretreated weaned pigs experimentally infected with F4ac+ enterotoxigenic Escherichia coli strain

    Science.gov (United States)

    Valpotić, H.; Kovšca Janjatović, A.; Lacković, G.; Božić, F.; Dobranić, V.; Svoboda, D.; Valpotić, I.; Popović, M.

    2010-01-01

    Immunoprophylaxis of porcine postweaning colibacillosis (PWC) caused by enterotoxigenic Escherichia coli (ETEC) expressing F4 fimbriae is an unsolved problem. Just as ETEC strains can exploit intestinal microfold (M) cells as the entry portal for infection, their high transcytotic ability make them an attractive target for mucosally delivered vaccines, adjuvants and therapeutics. We have developed a model of parenteral/oral immunization of 4-weeks-old pigs with either levamisole or vaccine candidate F4ac+ non-ETEC strain to study their effects on de novo differentiation of antigen-sampling M cells. Identification, localization and morphometric quantification of cytokeratin 18 positive M cells in the ileal mucosa of 6-weeks-old pigs revealed that they were: 1) exclusively located within villous epithelial layer, 2) significantly numerous (P< 0.01) in levamisole pretreated/challenged pigs, and 3) only slightly, but not significantly numerous in vaccinated/challenged pigs compared with non-pretreated/challenged control pigs. The fact that levamisole may affect the M cells frequency by increasing their numbers, makes it an interesting adjuvant to study development of an effective M cell-targeted vaccine against porcine PWC. PMID:22073366

  11. Expresión fenotípica de una sordera familiar con deleción del gen POU3F4

    Directory of Open Access Journals (Sweden)

    Ibis Menéndez

    1999-12-01

    Full Text Available Se presenta una familia cubana con 5 miembros afectados por una hipoacusia bilateral, congénita, severa, mixta con componente neurosensorial predominante y sin alteraciones morfológicas de oído interno. El patrón de transmisión era compatible con la herencia recesiva ligada al cromosoma X. Los estudios moleculares detectaron una deleción en la región Xq21.1 que implica el gen POU3F4, responsable de la sordera de tipo DFN3. Se hacen comentarios sobre la evidente variabilidad clínica de las sorderas tipo DFN3.A Cuban five-member family affected by a severe congenital bilateral mixed deafness with predominant sensorineural component and without morphological changes in the internal hearing is presented in this study. The transmission pattern was compatible with X-linked recessive heritage. The molecular studies detected a deletion of Xq 21 region involving POU3F4 gene which is responsible for DFN3-type deafness. Comments are made on the obvious clinical variability of DFN3-type deafness.

  12. The use of quantitative PCR for identification and quantification of Brachyspira pilosicoli, Lawsonia intracellularis and Escherichia coli fimbrial types F4 and F18 in pig feces

    DEFF Research Database (Denmark)

    Ståhl, Marie; Kokotovic, Branko; Hjulsager, Charlotte Kristiane

    2011-01-01

    than the earlier used method due to improvements in DNA extraction. In addition, as samples were not analysed for all four pathogen agents by traditional diagnostic methods, many samples were found positive for agents that were not expected on the basis of age and case history. The use of quantitative...... the spiking experiments were 102 bacteria/g feces for BpiloqPCR and Laws-qPCR, 103 CFU/g feces for F4-qPCR and F18-qPCR. The PCR efficiency for all four qPCR assays was between 0.91 and 1.01 with R2 above 0.993. Standard curves, slopes and elevation, varied between assays and between measurements from pure...... DNA from reference strains and feces spiked with the respective strains. The linear ranges found for spiked fecal samples differed both from the linear ranges from pure culture of the reference strains and between the qPCR tests. The linear ranges were five log units for F4- qPCR, and Laws-qPCR, six...

  13. Increased number of intestinal villous M cells in levamisole - pretreated weaned pigs experimentally infected with F4ac+ enterotoxigenic Escherichia coli strain

    Directory of Open Access Journals (Sweden)

    H. Valpotić

    2010-07-01

    Full Text Available Immunoprophylaxis of porcine postweaning colibacillosis (PWC caused by enterotoxigenic Escherichia coli (ETEC expressing F4 fimbriae is an unsolved problem. Just as ETEC strains can exploit intestinal microfold (M cells as the entry portal for infection, their high transcytotic ability make them an attractive target for mucosally delivered vaccines, adjuvants and therapeutics. We have developed a model of parenteral/oral immunization of 4-weeks-old pigs with either levamisole or vaccine candidate F4ac+ non-ETEC strain to study their effects on de novo differentiation of antigen-sampling M cells. Identification, localization and morphometric quantification of cytokeratin 18 positive M cells in the ileal mucosa of 6-weeks-old pigs revealed that they were: 1 exclusively located within villous epithelial layer, 2 significantly numerous (P< 0.01 in levamisole pretreated/challenged pigs, and 3 only slightly, but not significantly numerous in vaccinated/challenged pigs compared with non-pretreated/challenged control pigs. The fact that levamisole may affect the M cells frequency by increasing their numbers, makes it an interesting adjuvant to study development of an effective M cell-targeted vaccine against porcine PWC.

  14. Identification of a novel mutation in POU3F4 for prenatal diagnosis in a Chinese family with X-linked nonsyndromic hearing loss

    Institute of Scientific and Technical Information of China (English)

    Jianzhong Li; Dongyi Han; Huijun Yuan; Jing Cheng; Yanping Lu; Yu Lu; Aiting Chen; Yi Sun; Dongyang Kang; Xin Zhang; Pu Dai

    2010-01-01

    We present the clinical and genetic findings for a Chinese family with X-linked non-syndromic hearing loss in which the affected males showed congenital profound sensorineural hearing impairment. In two affected brothers, the computer tomography of temporal bone showed bilateral dilation of the internal auditory canal with fistulous communication between the lateral canal and the basal cochlear turn, which is consistent with the typical DFNX2 phenotype. A missense mutation (c.647G→A) in the POU3F4 gene caused a substitution from glycine to glutamic acid at position 216 (p.G216E), and this mutation was found to consistently cosegregate with the deafness phenotype in the family. The mutation resulted in the loss of function of the POU3F4 by decreasing the affinity between the protein and DNA, as shown in silico by the structural analysis. Prenatal diagnosis of pregnant proband of this family revealed the C.647G→A mutation in DNA extracted from the amniotic fluid surrounding the fetus. The appropriate use of genetic testing and prenatal diagnosis plays a key role in reducing the recurrence of genetic defects in high-risk families.

  15. Electrode-selective deposition/etching processes using an SiF4/H2/Ar plasma chemistry excited by sawtooth tailored voltage waveforms

    Science.gov (United States)

    Wang, J. K.; Johnson, E. V.

    2017-01-01

    We report on the electrode-selective deposition and etching of hydrogenated silicon thin films using a plasma enhanced chemical vapour deposition process excited by sawtooth-shaped tailored voltage waveforms (TVWs). The slope asymmetry of such waveforms leads to a different rate of sheath expansion and contraction at each electrode, and therefore different electron power absorption near each electrode. This effect was employed with an SiF4/H2/Ar plasma chemistry, as the surface processes that result from this gas mixture depend strongly on the local balance between multiple precursors. For a specific gas flow ratio, a deposition rate of 0.82 Å s-1 on one electrode and an etching rate of 1.2 Å s-1 on the other were achieved. Moreover, this deposition/etching balance is controlled by the H2 flow rate, which limits the deposition rate at low flows. When the H2 injection is sufficiently high, the processes are then limited by the dissociation of SiF4, and the relative rate of the surface processes on the two electrodes are reversed, i.e. a higher net deposition rate is observed on the electrode where the fast sheath contraction occurs due to the electronegative character of the plasma.

  16. Frequency Dependent Electrical and Dielectric Properties of Au/P3HT:PCBM:F4-TCNQ/n-Si Schottky Barrier Diode

    Science.gov (United States)

    Taşçıoğlu, İ.; Tüzün Özmen, Ö.; Şağban, H. M.; Yağlıoğlu, E.; Altındal, Ş.

    2017-04-01

    In this study, poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester: 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (P3HT:PCBM:F4-TCNQ) organic film was deposited on n-type silicon (n-Si) substrate by spin coating method. The electrical and dielectric analysis of Au/P3HT:PCBM:F4-TCNQ/n-Si Schottky barrier diode was conducted by means of capacitance-voltage ( C- V) and conductance-voltage ( G/ ω- V) measurements in the frequency range of 10 kHz-2 MHz. The C- V- f plots exhibit fairly large frequency dispersion due to excess capacitance caused by the presence of interface states ( N ss). The values of N ss located in semiconductor bandgap at the organic film/semiconductor interface were calculated by Hill-Coleman method. Experimental results show that dielectric constant ( ɛ') and dielectric loss ( ɛ″) decrease with increasing frequency, whereas loss tangent (tan δ) remains nearly the same. The decrease in ɛ' and ɛ″ was interpreted by the theory of dielectric relaxation due to interfacial polarization. It is also observed that ac electrical conductivity ( σ ac) and electric modulus ( M' and M″) increase with increasing frequency.

  17. Electronic structure of alkali-metal/alkaline-earth-metal fluorine beryllium borate NaSr3Be3B3O9F4 single crystal: DFT approach

    Science.gov (United States)

    Reshak, A. H.; Kamarudin, H.; Auluck, S.

    2015-10-01

    The electronic band structure, total and angular momentum resolved projected density of states for NaSr3Be3B3O9F4 are calculated using the all-electron full potential linearized augmented plane wave plus local orbitals (FP-LAPW + lo) method. The calculations are performed within four exchange correlations namely; local density approximation (LDA), general gradient approximation (PBE-GGA), Engel-Vosko generalized gradient approximation (EVGGA) and the recently modified Becke-Johnson potential (mBJ). Calculations suggest that NaSr3Be3B3O9F4 is a direct wide band gap semiconductor. The exchange correlations potentials exhibit significant influence on the value of the energy gap being about 4.82 eV (LDA), 5.16 eV (GGA), 6.20 (EVGGA) and 7.20 eV (mBJ). The mBJ approach succeed by large amount in bringing the calculated energy gap closer to the experimental one (7.28 eV). The angular momentum resolved projected density of states shows the existence of a strong hybridization between the various orbitals. In additional we have calculated the electronic charge density distribution in two crystallographic planes namely (1 0 1) and (0 0 -1) to visualized the chemical bonding characters.

  18. Synthesis,Crystal Structure and Reducibility of K2NiF4 Type Oxides Sm2—xSrxCuO4

    Institute of Scientific and Technical Information of China (English)

    ZHU,Ying-Hong; LOU,Hui; 等

    2002-01-01

    K2NiF4 type compounds Sm2-xSrxCuO4(0≤x≤1.2)were prepared.Rietveld refinement of powder diffraction data shows that the crystal system of these compounds belongs to T′ type tetragonal structure of space group I4/mmm,and the addition of Sr causes a dramatic shift of the O(I) ions along the c axis from Sm(Sr) toward Cu while scarcely affecting the Cu-O(Ⅱ)bond in basal CuO4 phane.From XRD data,it can be seen that when 0.0≤x≤0.6,Sm2-xSrxCuO4 belongs to a singlephase K2NiF4 type structure,while at x≥0.7,both the free SrO phase and the CuO phase exist in these compounds.From the results of XPS and rietveld refinement,it can be seen that after replacing Sm3+ with Sr2+ of lower valence,the valence of Cu and Sm does not change apparently,and thus some defect must be formed at the oxygen ion positions and/or position A on A2BO4 to keep charge balance and to stabilize the structure.

  19. Optical characterization of 2 kF bond-charge-density wave in quasi-one-dimensional 3 /4 -filled (EDO-TTF)2 X ( X= PF6 and AsF6 )

    Science.gov (United States)

    Drozdova, Olga; Yakushi, Kyuya; Yamamoto, Kaoru; Ota, Akira; Yamochi, Hideki; Saito, Gunzi; Tashiro, Hidenori; Tanner, David B.

    2004-08-01

    We present the electronic and vibrational spectra of quasi-one-dimensional (3)/(4) -filled (EDO-TTF)2X ( EDO-TTF=ethylenedioxy-tetrathiafulvalene , X=PF6 and AsF6 ) above and below the metal-insulator phase transition ( TMI=280K for the PF6 salt and 268K for the AsF6 salt). For the low-temperature insulating phase, the pattern of both bond and charge order was identified. Almost all charge density is localized on the strongly bound central pair of 0110 tetramer giving rise to a characteristic spectrum of electronic excitations. Infrared spectra along the stacking axis show evidence of strong electron-molecular vibration coupling between the charge transfer band within the pair and some specific intramolecular vibrations. This charge order is assisted by a molecular deformation.

  20. A cathode material based on the iron fluoride with an ultra-thin Li3FeF6 protective layer for high-capacity Li-ion batteries

    Science.gov (United States)

    Yang, Juan; Xu, Zhanglin; Zhou, Haochen; Tang, Jingjing; Sun, Hongxu; Ding, Jing; Zhou, Xiangyang

    2017-09-01

    Iron fluoride based on the multi-electron reaction is a typical representative among the new-style cathode materials for Lithium-ion batteries, which is attracting extensive attentions. To relieve the cathode dissolution and interfacial side reactions and improve the electrochemical performance of FeF3·0.33H2O, we design an ultra-thin Li3FeF6 protective layer, which is in-situ formed on the surface of FeF3·3H2O particles by a facile process. The prepared Li3FeF6/FeF3·0.33H2O (LF50) composite displays a superior rate performance (152 mAh g-1 at 1000 mA g-1), which is remarkable to many other carbon-free iron fluorides. And it is noticeable that a reversible capacity of 174 mAh g-1 can be retained after 100 cycles, indicating an outstanding cycling stability contrast to the bare FeF3·0.33H2O. The enhanced electrochemical performance is attributed to the protection of Li3FeF6 layer which reduces the cathode dissolution and interfacial side reactions. Moreover, the agglomeration of first particles in the calcination process is effectively suppressed resulting from the introduction of the Li3FeF6 protective layer, which promotes electrolyte penetration and charge transfer in the composites. It is expected that the strategy can provide a new approach for the modification of other metal fluoride.

  1. Spectrometric analysis of process etching solutions of the photovoltaic industry--determination of HNO3, HF, and H2SiF6 using high-resolution continuum source absorption spectrometry of diatomic molecules and atoms.

    Science.gov (United States)

    Bücker, Stefan; Acker, Jörg

    2012-05-30

    The surface of raw multicrystalline silicon wafers is treated with HF-HNO(3) mixtures in order to remove the saw damage and to obtain a well-like structured surface of low reflectivity, the so-called texture. The industrial production of solar cells requires a consistent level of texturization for tens of thousands of wafers. Therefore, knowing the actual composition of the etch bath is a key element in process control in order to maintain a certain etch rate through replenishment of the consumed acids. The present paper describes a novel approach to quantify nitric acid (HNO(3)), hydrofluoric acid (HF), and hexafluosilicic acid (H(2)SiF(6)) using a high-resolution continuum source graphite furnace absorption spectrometer. The concentrations of Si (via Si atom absorption at the wavelength 251.611 nm, m(0),(Si)=130 pg), of nitrate (via molecular absorption of NO at the wavelength 214.803 nm, [Formula: see text] ), and of total fluoride (via molecular absorption of AlF at the wavelength 227.46 nm, m(0,F)=13 pg) were measured against aqueous standard solutions. The concentrations of H(2)SiF(6) and HNO(3) are directly obtained from the measurements. The HF concentration is calculated from the difference between the total fluoride content, and the amount of fluoride bound as H(2)SiF(6). H(2)SiF(6) and HNO(3) can be determined with a relative uncertainty of less than 5% and recoveries of 97-103% and 96-105%, respectively. With regards to HF, acceptable results in terms of recovery and uncertainty are obtained for HF concentrations that are typical for the photovoltaic industry. The presented procedure has the unique advantage that the concentration of both, acids and metal impurities in etch solutions, can be routinely determined by a single analytical instrument. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Crystal chemistry of anion-excess ReO3-related phases. III. γ-ZrF4, a high-pressure form of zirconiumtetra fluoride, and a comparison of MX4 structure types.

    Science.gov (United States)

    Laval, Jean Paul

    2014-08-01

    The crystal structure of the high-pressure (4-8 GPa) form of zirconium tetrafluoride, γ-ZrF4, is based on the association by corner- and edge-sharing of ZrF8 triangulated dodecahedra, forming a three-dimensional framework. It presents some analogies with high-temperature α-ZrF4 but clearly constitutes a new MX4 structure type. The main MX4 ionic structure types, and especially those deriving from the `anion-excess ReO3-type', are compared and it is shown that the TeF4 structure can also be included in this family.

  3. Estimation of Ce 4f-5d Interaction by Analysis of Partial Fluorescence Yield at the Ce L3 Edge of CeO2

    Science.gov (United States)

    Tonai, Hironori; Sasabe, Norimasa; Uozumi, Takayuki; Kawamura, Naomi; Mizumaki, Masaichiro

    2017-09-01

    Partial fluorescence yield (PFY) spectroscopy, which corresponds to a high-resolution version of the X-ray absorption spectroscopy (XAS), is experimentally performed at the Ce L3 edge of CeO2, and the result is theoretically analyzed using an impurity Anderson model (IAM). In order to estimate the Ce 4f-5d interaction Ufd, we employ a semi-empirical IAM framework based on the local density approximation+U method; Slater-Koster parameters describing the valence of CeO2 are estimated by band mapping within the linear combination of atomic orbitals scheme, and the resulting realistic valence structure is considered in the IAM analysis. The global structure of the PFY-XAS result, which consists of the Ce 2p3/2 → 5d dipole transition and the Ce 2p3/2 → 4f quadrupole transition, is excellently reproduced by the calculation. The Ufd value is estimated to be 3.0 eV. We emphasize that the sensitivity of PFY-XAS to Ufd makes it a good ruler for obtaining the Ufd values of Ce compounds.

  4. MicroRNA-128-2 targets the transcriptional repressor E2F5 enhancing mutant p53 gain of function

    Science.gov (United States)

    Donzelli, S; Fontemaggi, G; Fazi, F; Di Agostino, S; Padula, F; Biagioni, F; Muti, P; Strano, S; Blandino, G

    2012-01-01

    p53 mutations have profound effects on non-small-cell lung cancer (NSCLC) resistance to chemotherapeutic treatments. Mutant p53 proteins are usually expressed at high levels in tumors, where they exert oncogenic functions. Here we show that p53R175H, a hotspot p53 mutant, induces microRNA (miRNA)-128-2 expression. Mutant p53 binds to the putative promoter of miR128-2 host gene, ARPP21, determining a concomitant induction of ARPP21 mRNA and miR-128-2. miR-128-2 expression in lung cancer cells inhibits apoptosis and confers increased resistance to cisplatin, doxorubicin and 5-fluorouracyl treatments. At the molecular level, miR-128-2 post-transcriptionally targets E2F5 and leads to the abrogation of its repressive activity on p21waf1 transcription. p21waf1 protein localizes to the cytoplasmic compartment, where it exerts an anti-apoptotic effect by preventing pro-caspase-3 cleavage. This study emphasizes miRNA-128-2 role as a master regulator in NSCLC chemoresistance. PMID:22193543

  5. Lipid profiling following intake of the omega 3 fatty acid DHA identifies the peroxidized metabolites F4-neuroprostanes as the best predictors of atherosclerosis prevention.

    Directory of Open Access Journals (Sweden)

    Cécile Gladine

    Full Text Available The anti-atherogenic effects of omega 3 fatty acids, namely eicosapentaenoic (EPA and docosahexaenoic acids (DHA are well recognized but the impact of dietary intake on bioactive lipid mediator profiles remains unclear. Such a profiling effort may offer novel targets for future studies into the mechanism of action of omega 3 fatty acids. The present study aimed to determine the impact of DHA supplementation on the profiles of polyunsaturated fatty acids (PUFA oxygenated metabolites and to investigate their contribution to atherosclerosis prevention. A special emphasis was given to the non-enzymatic metabolites knowing the high susceptibility of DHA to free radical-mediated peroxidation and the increased oxidative stress associated with plaque formation. Atherosclerosis prone mice (LDLR(-/- received increasing doses of DHA (0, 0.1, 1 or 2% of energy during 20 weeks leading to a dose-dependent reduction of atherosclerosis (R(2 = 0.97, p = 0.02, triglyceridemia (R(2 = 0.97, p = 0.01 and cholesterolemia (R(2 = 0.96, p<0.01. Targeted lipidomic analyses revealed that both the profiles of EPA and DHA and their corresponding oxygenated metabolites were substantially modulated in plasma and liver. Notably, the hepatic level of F4-neuroprostanes, a specific class of DHA peroxidized metabolites, was strongly correlated with the hepatic DHA level. Moreover, unbiased statistical analysis including correlation analyses, hierarchical cluster and projection to latent structure discriminate analysis revealed that the hepatic level of F4-neuroprostanes was the variable most negatively correlated with the plaque extent (p<0.001 and along with plasma EPA-derived diols was an important mathematical positive predictor of atherosclerosis prevention. Thus, oxygenated n-3 PUFAs, and F4-neuroprostanes in particular, are potential biomarkers of DHA-associated atherosclerosis prevention. While these may contribute to the anti-atherogenic effects of DHA

  6. TiF4 and NaF varnishes as anti-erosive agents on enamel and dentin erosion progression in vitro

    OpenAIRE

    Livia Picchi COMAR; Cardoso, Cristiane de Almeida Baldini; Charone, Senda; Grizzo, Larissa Tercilia; Marília Afonso Rabelo BUZALAF; Magalhães,Ana Carolina

    2015-01-01

    Objective This study assessed the effect of fluoride varnishes on the progression of tooth erosion in vitro. Material and Methods: Forty-eight enamel and 60 root dentin samples were previously demineralized (0.1% citric acid, pH 2.5, 30 min), leading to a baseline and erosive wear of 12.9 and 11.4 µm, respectively. The samples were randomly treated (6 h) with a 4% TiF4 varnish (2.45%F-, pH 1.0), a 5.42% NaF varnish (2.45%F-, pH 5.0), a placebo varnish and no varnish (control). The sample...

  7. Effect of lithium halide on glass network structure and upconversion luminescence in Er3+ co-doped oxyfluoride glass ceramics containing NaGdF4 nanocrystals

    Science.gov (United States)

    Ren, Peng; Yang, Yong; Zhou, Dacheng; Li, Zhencai; Qiu, Jianbei

    2017-10-01

    LiR(R = Br, Cl, F) co-doped oxyfluoride glass ceramics containing NaGdF4 nanocrystals were prepared. The effect on glass network structure by dopants was investigated through the Raman spectra. The crystallization temperature and integrity of the glass network structure was gradually reduced by introducing halogen ions. The types and distribution of nanocrystals were determined by X-ray diffraction and transmission electron microscope. The size of nanocrystals were shown in column type distribution map. The mean size of nanocrystals was bigger from SABr to SAF. The upconversion luminescence of Er3+ in SABr, SACl and SAF were study. The intensity ratio of red and green light was reduced in glass ceramics when the content from LiBr turn to LiF.

  8. Catalytic combustion of diesel soot over K2NiF4-type oxides La2-xKxCuO4

    Institute of Scientific and Technical Information of China (English)

    ZHU Ling; WANG Xuezhong; LIANG Cunzhen

    2008-01-01

    Nanostructure K2NiF4 type oxides La2-xKxCuO4 complex oxides were prepared using the Sol-Gel method, characterized by X-Ray Diffraction (XRD), Fourier Transform Infrared (FT-IR), and Scanning Electron Microscopy (SEM). The catalytic activity for soot combustion was evaluated by the Temperature-Programmed Reaction (TPO) technique. The results demonstrated that the substitution quality of K+ for La3+ at the A-site would increase the catalytic activities of La2-xKxCuO4 for soot combustion greatly; the substitution quality affected the structure and catalytic activity obviously. The La1.8K0.2CuO4 complex oxides with tetrahedral structures had the best catalytic activity for soot combustion, and the ignition temperature of soot combustion was lowered from 490 to 320 °C.

  9. A study of growth mechanism of microcrystalline thin silicon films deposited at low temperature by SiF4{text{-}H2{text{-}}He} PECVD

    Science.gov (United States)

    Losurdo, M.; Giangregorio, M.; Grimaldi, A.; Capezzuto, P.; Bruno, G.

    2004-06-01

    Fully microcrystalline silicon, μc-Si, thin films (polyimide substrates by plasma enhanced chemical vapor deposition (PECVD) using SiF{4}-H{2}-He. The effect of deposition temperature on the structure, i.e., crystallinity and density, of μc-Si films is investigated by spectroscopic ellipsometry in the 1.5 {-}5.5 eV energy range. Modeling of spectroscopic ellipsometry data is used for highlighting crystallinity of the substrate/film interface, i.e., the absence of any amorphous incubation layer. It is found that film crystallinity does not depend on film thickness, and it increases with the decrease of deposition temperature. The temperature dependence is explained on the basis of a like-Arrhenius kinetic analysis of the etching process by atomic fluorine and hydrogen of both μc-Si and a-Si phases.

  10. New Layered Oxide-Fluoride Perovskites: KNaNbOF5 and KNaMO2F4 (M = Mo6+, W6+

    Directory of Open Access Journals (Sweden)

    Rachelle Ann F. Pinlac

    2011-03-01

    Full Text Available KNaNbOF5 and KNaMO2F4 (M = Mo6+, W6+, three new layered oxide-fluoride perovskites with the general formula ABB’X6, form from the combination of a second-order Jahn-Teller d0 transition metal and an alkali metal (Na+ on the B-site. Alternating layers of cation vacancies and K+ cations on the A-site complete the structure. The K+ cations are found in the A-site layer where the fluoride ions are located. The A-site is vacant in the adjacent A-site layer where the axial oxides are located. This unusual layered arrangement of unoccupied A-sites and under bonded oxygen has not been observed previously although many perovskite-related structures are known.

  11. Barrierless association of CF2 and dissociation of C2F4 by variational transition-state theory and system-specific quantum Rice-Ramsperger-Kassel theory.

    Science.gov (United States)

    Bao, Junwei Lucas; Zhang, Xin; Truhlar, Donald G

    2016-11-29

    Bond dissociation is a fundamental chemical reaction, and the first principles modeling of the kinetics of dissociation reactions with a monotonically increasing potential energy along the dissociation coordinate presents a challenge not only for modern electronic structure methods but also for kinetics theory. In this work, we use multifaceted variable-reaction-coordinate variational transition-state theory (VRC-VTST) to compute the high-pressure limit dissociation rate constant of tetrafluoroethylene (C2F4), in which the potential energies are computed by direct dynamics with the M08-HX exchange correlation functional. To treat the pressure dependence of the unimolecular rate constants, we use the recently developed system-specific quantum Rice-Ramsperger-Kassel theory. The calculations are carried out by direct dynamics using an exchange correlation functional validated against calculations that go beyond coupled-cluster theory with single, double, and triple excitations. Our computed dissociation rate constants agree well with the recent experimental measurements.

  12. CLEC4F is an inducible C-type lectin in F4/80-positive cells and is involved in alpha-galactosylceramide presentation in liver.

    Directory of Open Access Journals (Sweden)

    Chih-Ya Yang

    Full Text Available CLEC4F, a member of C-type lectin, was first purified from rat liver extract with high binding affinity to fucose, galactose (Gal, N-acetylgalactosamine (GalNAc, and un-sialylated glucosphingolipids with GalNAc or Gal terminus. However, the biological functions of CLEC4F have not been elucidated. To address this question, we examined the expression and distribution of murine CLEC4F, determined its binding specificity by glycan array, and investigated its function using CLEC4F knockout (Clec4f-/- mice. We found that CLEC4F is a heavily glycosylated membrane protein co-expressed with F4/80 on Kupffer cells. In contrast to F4/80, CLEC4F is detectable in fetal livers at embryonic day 11.5 (E11.5 but not in yolk sac, suggesting the expression of CLEC4F is induced as cells migrate from yolk cells to the liver. Even though CLEC4F is not detectable in tissues outside liver, both residential Kupffer cells and infiltrating mononuclear cells surrounding liver abscesses are CLEC4F-positive upon Listeria monocytogenes (L. monocytogenes infection. While CLEC4F has strong binding to Gal and GalNAc, terminal fucosylation inhibits CLEC4F recognition to several glycans such as Fucosyl GM1, Globo H, Bb3∼4 and other fucosyl-glycans. Moreover, CLEC4F interacts with alpha-galactosylceramide (α-GalCer in a calcium-dependent manner and participates in the presentation of α-GalCer to natural killer T (NKT cells. This suggests that CLEC4F is a C-type lectin with diverse binding specificity expressed on residential Kupffer cells and infiltrating monocytes in the liver, and may play an important role to modulate glycolipids presentation on Kupffer cells.

  13. Suppression of nuclear factor-kappa B and mitogen-activated protein kinase signalling pathways by goshonoside-F5 extracted from Rubi Fructus.

    Science.gov (United States)

    He, Jian-Ming; Chen, Shi-Cai; Li, Run-Ping; Yuan, Liang-Xi; Bao, Jun-Min; Guo, Mei-Li

    2015-02-01

    Rubi Fructus, a traditional Chinese medicine, was considered as an anti-inflammatory agent in folk medicine. In the present study, we investigated the signalling pathways involved in the anti-inflammatory effects of goshonoside-F5 (GF5), isolated from Rubi Fructus, in peritoneal macrophages and examined its therapeutic effect in a mouse endotoxic shock model. GF5 decreased NO and PGE2 production in LPS-stimulated macrophages (IC50=3.84 and 3.16μM). This effect involved the suppression of NOS-2 and COX-2 gene expression at the transcriptional level. Examination of the effects of GF5 on NF-κB signalling demonstrated that it inhibits the phosphorylation of IκB-α and IκB-β, blocking their degradation and the nuclear translocation of the NF-κB p65 subunit. Moreover, inhibition of MAPK signalling was also observed, and phosphorylation of p38 and JNK was suppressed in the presence of GF5. Inflammatory cytokines, including IL-6 and TNF-α, were down-regulated by this compound after activation with LPS (IC50=17.04 and 4.09μM). Additionally, GF5 (30 and 90mg/kg, i.p.) significantly reduced the circulating cytokine levels (IL-6 and TNF-α) and increased survival in a mouse model of endotoxemia. These results show that GF5 significantly inhibits the pro-inflammatory response induced by LPS, both in vitro and in vivo. Our results provide a strong pharmacological basis for further understanding the potential therapeutic role of GF5 in inflammatory disease and shed new light on the bioactivity of ent-labdane diterpene glucoside. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Atmospheric abundance and global emissions of perfluorocarbons CF4, C2F6 and C3F8 since 1800 inferred from ice core, firn, air archive and in situ measurements

    Science.gov (United States)

    Trudinger, Cathy M.; Fraser, Paul J.; Etheridge, David M.; Sturges, William T.; Vollmer, Martin K.; Rigby, Matt; Martinerie, Patricia; Mühle, Jens; Worton, David R.; Krummel, Paul B.; Steele, L. Paul; Miller, Benjamin R.; Laube, Johannes; Mani, Francis S.; Rayner, Peter J.; Harth, Christina M.; Witrant, Emmanuel; Blunier, Thomas; Schwander, Jakob; O'Doherty, Simon; Battle, Mark

    2016-09-01

    Perfluorocarbons (PFCs) are very potent and long-lived greenhouse gases in the atmosphere, released predominantly during aluminium production and semiconductor manufacture. They have been targeted for emission controls under the United Nations Framework Convention on Climate Change. Here we present the first continuous records of the atmospheric abundance of CF4 (PFC-14), C2F6 (PFC-116) and C3F8 (PFC-218) from 1800 to 2014. The records are derived from high-precision measurements of PFCs in air extracted from polar firn or ice at six sites (DE08, DE08-2, DSSW20K, EDML, NEEM and South Pole) and air archive tanks and atmospheric air sampled from both hemispheres. We take account of the age characteristics of the firn and ice core air samples and demonstrate excellent consistency between the ice core, firn and atmospheric measurements. We present an inversion for global emissions from 1900 to 2014. We also formulate the inversion to directly infer emission factors for PFC emissions due to aluminium production prior to the 1980s. We show that 19th century atmospheric levels, before significant anthropogenic influence, were stable at 34.1 ± 0.3 ppt for CF4 and below detection limits of 0.002 and 0.01 ppt for C2F6 and C3F8, respectively. We find a significant peak in CF4 and C2F6 emissions around 1940, most likely due to the high demand for aluminium during World War II, for example for construction of aircraft, but these emissions were nevertheless much lower than in recent years. The PFC emission factors for aluminium production in the early 20th century were significantly higher than today but have decreased since then due to improvements and better control of the smelting process. Mitigation efforts have led to decreases in emissions from peaks in 1980 (CF4) or early-to-mid-2000s (C2F6 and C3F8) despite the continued increase in global aluminium production; however, these decreases in emissions appear to have recently halted. We see a temporary reduction of around

  15. Produtividade e resistência à ferrugem do cafeeiro (Hemileia vastatrix BERK. ET BR. de progênies F5 de catuí amarelo com o híbrido de timor Produtivity and resistance to "Coffee Rust" (Hemileia vastatrix Berk. Et Br. of f5 progenies of catuaí amarelo with the híbrido de timor

    Directory of Open Access Journals (Sweden)

    José Messias Miranda

    2005-12-01

    Full Text Available Foram estudadas 18 progênies na geração F5 do híbrido H 419, provenientes do cruzamento entre o Híbrido de Timor (UFV 445-46 e o Catuaí Amarelo IAC 30 (UFV 2143, 5 progênies na geração F5 do híbrido H 516, proveniente do cruzamento entre o Híbrido de Timor (UFV 446-08 e o Catuaí Amarelo IAC 86 (UFV 2154 e como controle o Catuaí Vermelho IAC 44 ( UFV 2144 com e sem controle da ferrugem. Em relação a produção de café cereja por planta e ao ataque da ferrugem as progênies H419-3-1-1-14 e a H516-2-1-1-18, foram as que apresentaram maiores produtividades e resistência a ferrugem ( nota 1 , seguidas da H419-6-3-6-12, porém com resistência parcial à ferrugem. Essas progênies também foram as que apresentaram maior comprimento do ramo plagiotrópico, que influenciou em 37,73% (R² na produção de café cereja por planta. O comprimento do ramo plagiotrópico, diâmetro do tronco e altura das plantas foram os atributos que mais correlacionaram r= 0.5977, r= 0.3316 e r= 0.2848, respectivamente pEighteen progenies in the F5 generation of the H 419 hybrid were studied, proceeding from the crossing between the Híbrido deTimor (UFV 445-46 and the IAC 30 Catuaí Amarelo (UFV 2143, 5 progenies in the F5 generation of the H 516 hybrid, proceeding from the crossing between the Híbrido deTimor (UFV 446-08 and the IAC 86 Catuaí Amarelo (UFV 2154 and the IAC 44 the red Catuaí (UFV 2144 as control, with and without rust control. Regarding the production of cherry coffee by plant and with the rust attack, the H419-3-1-1-14 and the H516-2-1-1-18, progenies were the ones that showed greater productivity and rust resistance (grade 0, followed by the H419-6-3-6-12, but with partial rust resistance . These progenies were, also, the ones that showed greater length of the plagiotrophycal spreads, where influenciated in 37.73% (R² at production of cherry coffee by plant. The plagiotrophycal spread's length, fust diameter and plants height were the

  16. The Immunostimulation of F4ac ETEC-Culture Supernatant to Porcine Small Intestinal Epithelial Cells%F4ac型产肠毒素大肠杆菌菌液上清对仔猪小肠上皮细胞的免疫刺激作用

    Institute of Scientific and Technical Information of China (English)

    周传丽; 刘铮铸; 俞英; 张勤

    2014-01-01

    [Objective]Porcine enterotoxigenic Escherichia coli (ETEC) is a worldwide cause of bacteria induced diarrhoea in piglets. In the veterinary practices of pig production, serological identification of ETEC shows that F4ac is the most common serological type expressed in ETEC strains isolated from diarrheic piglets. So far, the mechanism by which ETEC produces diarrhoea in piglets has been clearly elucidated. However, the immunostimulation of ETEC-culture to host target cells has not been studied or described. In the present study, the immunostimulation of the supernatant of F4ac ETEC-culture to IPEC-J2 cells was studied.[Method]The culture of F4ac ETEC strain 200 was collected and centrifuged (4℃, 4 000 r/min for 15 min) after 12 hours in culture, and the supernatant was sterilized by passing it through a 0.22μm filter. The solution combined the sterilized supernatant with equivalent DMEM/F12 medium was used to challenge IPEC-J2 cells for 3 hours. The IPEC-J2 cells co-cultured with fresh LB medium and equivalent DMEM/F12 medium were as the control group. For both treatments, each experiment was repeated three times. Total RNAs of the stimulated and control IPEC-J2 cells were extracted using TRIZOL Reagent following the manufacturer’s instructions. According to the manufacturer’s instructions, complementary DNA (cDNA) was synthesized from RNA using the Prime Script® RT reagent Kit with gDNA Eraser (Perfect Real Time). The cDNA samples were then analyzed with real time RT-PCR using a LightCycler® 480 Real-Time PCR System. The real time RT-PCR reactions were performed in a final volume of 20μL with the Roche SYBR Green PCR Kit according to the manufacturer’s instructions. The pig house-keeping gene β-actin was used as the internal standards to correct the input of cDNA. Triplicate qRT-PCRs were performed on each cDNA and the average Ct was used for further analysis. The relative quantification values were calculated using the 2-ΔΔCt. Differential m

  17. Investigations on the local structure and the spin-Hamiltonian parameters for the tetragonal $Cu^{2+}$ centre in $ZnGeF_{6}·6H_{2}O$ crystal

    Indian Academy of Sciences (India)

    LI CHAO-YING; HUANG YING; ZHENG XUE MEI

    2016-08-01

    The spin-Hamiltonian parameters ($g$ factors $g_{||}, g{|perp}$ and hyperfine structure constants $A_{||}$, $A{|perp}$) and the local structure for the tetragonal $Cu^{2+}$ centre in trigonal $ZnGeF_{6}·6H_{2}O$ crystal are theoretically studied using the perturbation formulae of these parameters for a 3d9 ion in tetragonally elongated octahedra. In the calculations, the contributions to the spin-Hamiltonian parameters from ligand orbital and spin-orbit coupling are included on the basis of the cluster approach in view of moderate covalency of the studied systems, and the required crystal field parameters are obtained using the superposition model and the local structures of the studied $[Cu(H_{2}O)_{6}]^{2+}$ cluster. According to the calculations, the ligand octahedra around $Cu^{2+}$ suffer relative elongation$\\tau{\\sim 0.085 \\AA) along the [0 0 1] (or $C_4$) axis for the tetragonal $Cu^{2+}$ centres in $ZnGeF_{6}·6H_{2}O$ crystal, due to the Jahn--Teller effect. The calculated results show good agreement with the experimental data.

  18. Magnetism and Pressure-Induced Superconductivity of Checkerboard-Type Charge-Ordered Molecular Conductor β-(meso-DMBEDT-TTF2X (X = PF6 and AsF6

    Directory of Open Access Journals (Sweden)

    Yutaka Nishio

    2012-11-01

    Full Text Available The metallic state of the molecular conductor β-(meso-DMBEDT-TTF2X (DMBEDT-TTF = 2-(5,6-dihydro-1,3-dithiolo[4,5-b][1,4]dithiin-2-ylidene-5,6-dihydro-5,6-dimethyl-1,3-dithiolo[4,5-b][1,4]dithiin, X = PF6, AsF6 is transformed into the checkerboard-type charge-ordered state at around 75–80 K with accompanying metal-insulator (MI transition on the anisotropic triangular lattice. With lowering temperatures, the magnetic susceptibility decreases gradually and reveals a sudden drop at the MI transition. By applying pressure, the charge-ordered state is suppressed and superconductivity appears in β-(meso-DMBEDT-TTF2AsF6 as well as in the reported β-(meso-DMBEDT-TTF2PF6. The charge-ordered spin-gapped state and the pressure-induced superconducting state are discussed through the paired-electron crystal (PEC model, where the spin-bonded electron pairs stay and become mobile in the crystal, namely the valence-bond solid (VBS and the resonant valence bonded (RVB state in the quarter-filled band structure.

  19. The effect of [Co(DH2(An2]2[TiF6]∙3H2O coordination compound on polypeptide spectrum of amylolytic preparation from Aspergillus niger 33-19 CNMN FD 02A strain

    Directory of Open Access Journals (Sweden)

    Alexandra CILOCI

    2012-11-01

    Full Text Available From mycelial fungus Aspergillus niger 33-19 CNMN FD 02A cultivated on nutrient medium supplemented with [Co(DH2(An2]2[TiF6]∙3H2O coordination compound amylolytic preparation with total α-amylase activity of 40042U/g and a specific activity of 131.3U/mg proteins was obtained. Through gel filtration and ion exchange chromatography enzyme preparation was purified 7.8 fold with a yield of 13%. SDS-PAGE electr