Crystal structures and magnetic properties of two-dimensional antiferromagnets Co{sub 1-x}Zn{sub x}TeMoO{sub 6}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doi, Yoshihiro, E-mail: doi@sci.hokudai.ac.j; Suzuki, Ryo; Hinatsu, Yukio

2009-12-15

Crystal structures and magnetic properties of metal telluromolybdates Co{sub 1-x}Zn{sub x}TeMoO{sub 6} (x=0.0, 0.1,...,0.9) are reported. All the compounds have an orthorhombic structure with space group P2{sub 1}2{sub 1}2 and a charge configuration of M{sup 2+}Te{sup 4+}Mo{sup 6+}O{sub 6}. In this structure, M ions form a pseudo-two-dimensional lattice in the ab plane. Their magnetic susceptibility measurements have been performed in the temperature range between 1.8 and 300 K. The end member CoTeMoO{sub 6} shows a magnetic transition at 24.4 K. The transition temperature for solid solutions rapidly decreases with increasing x and this transition disappears between x=0.4 and 0.5, whichmore » is corresponding to the percolation limit for the square-planer lattice. From the magnetization, specific heat, and powder neutron diffraction measurements, it is found that the magnetic transition observed in the CoTeMoO{sub 6} is a canted antiferromagnetic ordering of Co{sup 2+} ions. The antiferromagnetic component of the ordered magnetic moment (3.12(3)mu{sub B} at 10 K) is along the b-axis. In addition, there exists a small ferromagnetic component (0.28(3)mu{sub B}) along the a-axis. - Graphical abstract: The metal telluromolybdates Co{sub 1-x}Zn{sub x}TeMoO{sub 6} have an orthorhombic structure with space group P2{sub 1}2{sub 1}2. In this structure, M ions form a pseudo-square-planer lattice in the ab plane. These compounds show a low-dimensional magnetism reflecting this structural feature. The magnetic transition observed in the CoTeMoO{sub 6} is a canted antiferromagnetic ordering of Co{sup 2+} ions, and the figure is the magnetic structure.« less

Crystal structures of Boro-AFm and sBoro-AFt phases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Champenois, Jean-Baptiste; Mesbah, Adel; Clermont Universite, ENSCCF, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand

2012-10-15

Crystal structures of boron-containing AFm (B-AFm) and AFt (B-AFt) phases have been solved ab-initio and refined from X-ray powder diffraction. {sup 11}B NMR and Raman spectroscopies confirm the boron local environment in both compounds: three-fold coordinated in B-AFm corresponding to HBO{sub 3}{sup 2-} species, and four-fold coordinated in B-AFt corresponding to B (OH){sub 4}{sup -} species. B-AFm crystallizes in the rhombohedral R3{sup Macron }c space group and has the 3CaO{center_dot}Al{sub 2}O{sub 3}{center_dot}CaHBO{sub 3}{center_dot}12H{sub 2}O (4CaO{center_dot}Al{sub 2}O{sub 3}{center_dot}1/2B{sub 2}O{sub 3}{center_dot}12.5H{sub 2}O, C{sub 4}AB{sub 1/2}H{sub 12.5}) general formulae with planar trigonal HBO{sub 3}{sup 2-} anions weakly bonded at the centre of themore » interlayer region. One HBO{sub 3}{sup 2-} anion is statistically distributed with two weakly bonded water molecules on the same crystallographic site. B-AFt crystallizes in the trigonal P3cl space group and has the 3CaO{center_dot}Al{sub 2}O{sub 3}{center_dot}Ca(OH){sub 2}{center_dot}2Ca(B (OH){sub 4}){sub 2}{center_dot}24H{sub 2}O (6CaO{center_dot}Al{sub 2}O{sub 3}{center_dot}2B{sub 2}O{sub 3}{center_dot}33H{sub 2}O, C{sub 6}AB{sub 2}H{sub 33}) general formulae with tetrahedral B (OH){sub 4}{sup -} anions located in the channel region of the structure. All tetrahedral anions are oriented in a unique direction, leading to a hexagonal c lattice parameter about half that of ettringite.« less

Synthesis and Structural Characterization of Magnesium Based Coordination Networks in Different Solvents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banerjee, Debasis; Finkelstein, Jeffrey; Smirnov, A.

2015-10-15

Three magnesium based metal-organic frameworks, Mg{sub 3}(3,5-PDC){sub 3}(DMF){sub 3} {center_dot} DMF [1], Mg(3,5-PDC)(H{sub 2}O) {center_dot} (H{sub 2}O) [3], and Mg4(3,5-PDC)4(DMF){sub 2}(H{sub 2}O){sub 2} {center_dot} 2DMF {center_dot} 4.5H{sub 2}O [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(H{sub 2}O){sub 2}] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2{sub 1}/n, a = 12.3475(5) {angstrom}, b = 11.1929(5) {angstrom}, c = 28.6734(12) {angstrom}, {beta} = 98.8160(10){sup o}, V = 3916.0(3) {angstrom}{sup 3}] consists of a combination of isolated and corner-sharing magnesium octahedra connected by the organic linkers to form a 3-D network withmore » a 12.2 {angstrom} x 4.6 {angstrom} 1-D channel. The channel contains coordinated and free DMF molecules. In compound 2 [space group C2/c, a = 9.964(5) {angstrom}, b = 12.0694(6) {angstrom}, c = 7.2763(4) {angstrom}, {beta} = 106.4970(6){sup o}, V = 836.70(6) {angstrom}{sup 3}], PDC connects isolated seven coordinated magnesium polyhedra into a layered structure. Compound 3 [space group P6{sub 1}22, a = 11.479(1) {angstrom}, c = 14.735(3) {angstrom}, V = 1681.7(4) {angstrom}{sup 3}] (previously reported) contains isolated magnesium octahedra connected by the organic linker with each other forming a 3D network. Compound 4 [space group P2{sub 1}/c, a = 13.7442(14) {angstrom}, b = 14.2887(15) {angstrom}, c = 14.1178(14) {angstrom}, {beta} = 104.912(2){sup o}, V = 2679.2(5) {angstrom}{sup 3}] also exhibits a 3D network based on isolated magnesium octahedra with square cavities containing both disordered DMF and water molecules. The structural topologies originate due to the variable coordination ability of solvent molecules with the metal center. Water molecules coordinate with the magnesium metal centers preferably over other polar solvents (DMF, methanol, ethanol) used to synthesize the coordination networks. Despite testing multiple desolvation routes, we were unable to measure BET surface areas greater than 51.9 m{sup 2}/g for compound 1.« less

Crystal structure of Rb{sub 2}Mn{sub 3}(H{sub 2}O){sub 2}[P{sub 2}O{sub 7}]{sub 2}, a new representative of the family of hydrated diphosphates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiriukhina, G. V., E-mail: g-biralo@yandex.ru; Yakubovich, O. V.; Dimitrova, O. V.

2016-09-15

The crystal structure of Rb{sub 2}Mn{sub 3}(H{sub 2}O){sub 2}[P{sub 2}O{sub 7}]{sub 2}, a new phase obtained in the form of single crystals under hydrothermal conditions in the MnCl{sub 2}–Rb{sub 3}PO{sub 4}–H{sub 2}O system, is determined by X-ray diffraction (Xcalibur-S-CCD diffractometer, R = 0.0270): a = 9.374(2), b = 8.367(2), c = 9.437(2) Å, ß = 99.12(2)°, space group P2{sub 1}/c, Z = 2, D{sub x} = 3.27 g/cm{sup 3}. A correlation between the unit-cell parameters and the size of cations forming the crystal structures of isostructural A{sub 2}M{sub 3}(H{sub 2}O){sub 2}[P{sub 2}O{sub 7}]{sub 2} diphosphates (A = K, NH{sub 4},more » Rb, or Na; {sub M} = Mn, Fe, Co, or Ni) is revealed. It is shown that, due to the topological similarity, the structures of diphosphates and orthophosphates of the farringtonite structural type can undergo mutual transformations.« less

Crystal and molecular structures of pentaammine(pyrazine)ruthenium(II) tetrafluoroborate and pentaammine(pyrazine)ruthenium(III) trifluoromethanesulfonate monohydrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gress, M.E.; Creutz, C.; Quicksall, C.O.

1981-05-01

For (Ru(NH/sub 3/)/sub 5/(C/sub 4/N/sub 2/H/sub 4/))(BF/sub 4/)/sub 2/ the space group is P2/sub 1/2/sub 1/2/sub 1/ with cell parameters a = 12.615 (2) A, b = 15.610 (3) A, c = 7.965 (2) A, and Z = 4. For (Ru(NH/sub 3/)/sub 5/(C/sub 4/N/sub 2/H/sub 4/))(CF/sub 3/SO/sub 3/)/sub 3/.H/sub 2/O the space group is Pnma with cell parameters a = 23.795 (4) A, b = 8.062 (2) A, c = 12.848 (2) A, and Z = 4. The geometries of both the Ru(NH/sub 3/)/sub 5/pz/sup 2 +/ (pz = pyrazine) and Ru(NH/sub 3/)/sub 5/pz/sup 3 +/ cations are approximately octahedral,more » with the plane of the pyrazine ring intersecting at a 45/sup 0/ angle the equatorial plane containing the bound pyrazine N and the three N atoms of the NH/sub 3/ groups, as is expected from steric considerations. The Ru-NH/sub 3/ bond lengths are similar to those found in other ammine complexes: Ru(II)-NH/sub 3/, 2.15 to 2.17 A; Ru(III)-NH/sub 3/, 2.10 to 2.13 A. By contrast the Ru(II)-pz bond (2.006 A) is shorter than the Ru(III)-pz bond (2.076 A) by 0.07 A. This is attributed to ..pi.. back-bonding between Ru(II) and pyrazine. The dimensions of the mononuclear ions Ru(NH/sub 3/)/sub 5/pz/sup 2 +/ and Ru(NH/sub 3/)/sub 5/pz/sup 3 +/ are used to model the structure of valence-localized Ru/sup II/(NH/sub 3/)/sub 5/pzRu/sup III/(NH/sub 3/)/sub 5//sup 5 +/. The observed properties of this ion are then compared with those predicted from Marcus-Hush electron-transfer theory.« less

Synthesis optimisation and characterisation of the organic-inorganic layered materials ZnS(m-xylylenediamine){sub 1/2} and ZnS(p-xylylenediamine){sub 1/2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luberda-Durnaś, K.; Guillén, A. González; Łasocha, W., E-mail: lasocha@chemia.uj.edu.pl

2016-06-15

Hybrid organic-inorganic layered materials of the type ZnS(amine){sub 1/2}, where amine=m-xylylenediamine (MXDA) or p-xylylenediamine (PXDA), were synthesised using a simple solvothermal method. Since the samples crystallised in the form of very fine powder, X-ray powder diffraction techniques were used for structural characterisation. The crystal structure studies, involving direct methods, show that both compounds crystallised in the orthorhombic crystal system, but in different space groups: ZnS(MXDA){sub 1/2} in non-centrosymmetric Ccm2{sub 1}, ZnS(PXDA){sub 1/2} in centrosymmetric Pcab. The obtained materials are built according to similar orders: semiconducting monolayers with the formula ZnS, parallel to the (010) plane, are separated by diamines. Themore » organic and inorganic fragments are connected by covalent bonds between metal atoms of the layers and nitrogen atoms of the amino groups. The optical properties of the hybrid materials differ from those of their bulk counterpart. In both compounds a blue-shift of about 0.8 or 0.9 eV was observed with reference to the bulk phase of ZnS. - Highlights: • New hybrid compounds: ZnS(MXDA){sub 1/2} and ZnS(PXDA){sub 1/2} were obtained. • Hybrids were studied using XRD, TG/DSC, XRK, SEM, UV–vis spectroscopy. • Structures of both materials were solved by powder diffraction methods.« less

Li{sub 2}Sr{sub 4}B{sub 12}O{sub 23}: A new alkali and alkaline-earth metal mixed borate with [B{sub 10}O{sub 18}]{sup 6-} network and isolated [B{sub 2}O{sub 5}]{sup 4-} unit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Min; Graduate University of Chinese Academy of Sciences, Beijing 100049; Pan Shilie, E-mail: slpan@ms.xjb.ac.cn

2012-06-15

A novel ternary lithium strontium borate Li{sub 2}Sr{sub 4}B{sub 12}O{sub 23} crystal with size up to 20 mm Multiplication-Sign 10 mm Multiplication-Sign 4 mm has been grown via the top-seeded solution growth method below 730 Degree-Sign C. Single-crystal XRD analyses showed that Li{sub 2}Sr{sub 4}B{sub 12}O{sub 23} crystallizes in the monoclinic space group P2{sub 1}/c with a=6.4664(4) A, b=8.4878(4) A, c=15.3337(8) A, {beta}=102.02(3) Degree-Sign , Z=2. The crystal structure is composed of [B{sub 10}O{sub 18}]{sup 6-} network and isolated [B{sub 2}O{sub 5}]{sup 4-} unit. The IR spectrum further confirmed the presence of both BO{sub 3} and BO{sub 4} groups. TG-DSCmore » and Transmission spectrum were reported. Band structures and density of states were calculated. - Graphical abstract: A new phase, Li{sub 2}Sr{sub 4}B{sub 12}O{sub 23}, has been discovered in the ternary M{sub 2}O-M Prime O-B{sub 2}O{sub 3} (M=alkali-metal, M Prime =alkalineearth metal) system. The crystal structure consists of [B{sub 10}O{sub 18}]{sup 6-} network and isolated [B{sub 2}O{sub 5}]{sup 4-} unit. Highlights: Black-Right-Pointing-Pointer Li{sub 2}Sr{sub 4}B{sub 12}O{sub 23} is a a novel borate discovered in the M{sub 2}O-M Prime O-B{sub 2}O{sub 3} (M=alkali-metal, M Prime =alkaline-earth metal) system. Black-Right-Pointing-Pointer Li{sub 2}Sr{sub 4}B{sub 12}O{sub 23} crystal structure has a three-dimensional crystal structure with [B{sub 10}O{sub 18}]{sup 6-} network and isolated [B{sub 2}O{sub 5}]{sup 4-} unit. Black-Right-Pointing-Pointer Sr{sub 1} and Sr{sub 2} are located in two different channels constructed by {sup 3}{sub {infinity}}[B{sub 10}O{sub 18}] network.« less

Crystallization and preliminary X-ray crystallographic analysis of the heterodimeric crotoxin complex and the isolated subunits crotapotin and phospholipase A{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santos, K. F.; Murakami, M. T.; Cintra, A. C. O.

2007-04-01

Crotoxin, a potent neurotoxin from the venom of the South American rattlesnake Crotalus durissus terrificus, exists as a heterodimer formed between a phospholipase A{sub 2} and a catalytically inactive acidic phospholipase A{sub 2} analogue (crotapotin). Large single crystals of the crotoxin complex and of the isolated subunits have been obtained. Crotoxin, a potent neurotoxin from the venom of the South American rattlesnake Crotalus durissus terrificus, exists as a heterodimer formed between a phospholipase A{sub 2} and a catalytically inactive acidic phospholipase A{sub 2} analogue (crotapotin). Large single crystals of the crotoxin complex and of the isolated subunits have been obtained.more » The crotoxin complex crystal belongs to the orthorhombic space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 38.2, b = 68.7, c = 84.2 Å, and diffracted to 1.75 Å resolution. The crystal of the phospholipase A{sub 2} domain belongs to the hexagonal space group P6{sub 1}22 (or its enantiomorph P6{sub 5}22), with unit-cell parameters a = b = 38.7, c = 286.7 Å, and diffracted to 2.6 Å resolution. The crotapotin crystal diffracted to 2.3 Å resolution; however, the highly diffuse diffraction pattern did not permit unambiguous assignment of the unit-cell parameters.« less

Electric field induced cubic to monoclinic phase transition in multiferroic 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} solid solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pandey, Rishikesh; Singh, Akhilesh Kumar, E-mail: akhilesh-bhu@yahoo.com

2014-10-20

The results of x-ray diffraction studies on 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} solid solution poled at various electric fields are presented. After poling, significant value of planar electromechanical coupling coefficient (k{sub P}) is observed for this composition having cubic structure in unpoled state. The cubic structure of 0.65Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-0.35PbTiO{sub 3} transforms to monoclinic structure with space group Pm for the poling field ≥5 kV/cm. Large c-axis microscopic lattice strain (1.6%) is achieved at 30 kV/cm poling field. The variation of the c-axis strain and unit cell volume with poling field shows a drastic jump similar to that observed for strainmore » versus electric field curve in (1 − x)Pb(Mg{sub 1/3}Nb{sub 2/3}) O{sub 3}-xPbTiO{sub 3} and (1 − x)Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-xPbTiO{sub 3}.« less

Grain size dependent phase stabilities and presence of a monoclinic (Pm) phase in the morphotropic phase boundary region of (1−x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} piezoceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Upadhyay, Ashutosh; Singh, Akhilesh Kumar, E-mail: akhilesh-bhu@yahoo.com, E-mail: aksingh.mst@itbhu.ac.in

2015-04-14

Results of the room temperature structural studies on (1−x)Bi(Mg{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} ceramics using Rietveld analysis of the powder x-ray diffraction data in the composition range 0.28 ≤ x ≤ 0.45 are presented. The morphotropic phase boundary region exhibits coexistence of monoclinic (space group Pm) and tetragonal (space group P4 mm) phases in the composition range 0.33 ≤ x ≤ 0.40. The structure is nearly single phase monoclinic (space group Pm) in the composition range 0.28 ≤ x ≤ 0.32. The structure for the compositions with x ≥ 0.45 is found to be predominantly tetragonal with space group P4 mm. Rietveld refinement of the structure rules out the coexistence of rhombohedral and tetragonal phases inmore » the morphotropic phase boundary region reported by earlier authors. The Rietveld structure analysis for the sample x = .35 calcined at various temperatures reveals that phase fraction of the coexisting phases in the morphotropic phase boundary region varies with grain size. The structural parameters of the two coexisting phases also change slightly with changing grain size.« less

Crystallization and preliminary X-ray diffraction analysis of the arginine repressor of the hyperthermophile Thermotoga neapolitana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Massant, Jan, E-mail: jan.massant@vub.ac.be; Peeters, Eveline; Charlier, Daniel

2006-01-01

The arginine repressor of the hyperthermophile T. neapolitana was crystallized with and without its corepressor arginine. Both crystals diffracted to high resolution and belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with similar unit-cell parameters. The arginine repressor of Thermotoga neapolitana (ArgRTnp) is a member of the family of multifunctional bacterial arginine repressors involved in the regulation of arginine metabolism. This hyperthermophilic repressor shows unique DNA-binding features that distinguish it from its homologues. ArgRTnp exists as a homotrimeric protein that assembles into hexamers at higher protein concentrations and/or in the presence of arginine. ArgRTnp was crystallized with andmore » without its corepressor arginine using the hanging-drop vapour-diffusion method. Crystals of the aporepressor diffracted to a resolution of 2.1 Å and belong to the orthorhombic P2{sub 1}2{sub 1}2{sub 1} space group, with unit-cell parameters a = 117.73, b = 134.15, c = 139.31 Å. Crystals of the repressor in the presence of its corepressor arginine diffracted to a resolution of 2.4 Å and belong to the same space group, with similar unit-cell parameters.« less

Crystal structures of the new ternary stannides La{sub 3}Mg{sub 4−x}Sn{sub 2+x} and LaMg{sub 3−x}Sn{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solokha, P., E-mail: pavlo.solokha@unige.it; De Negri, S.; Minetti, R.

2016-01-15

Synthesis and structural characterization of the two new lanthanum–magnesium–stannides La{sub 3}Mg{sub 4−x}Sn{sub 2+x} (0.12≤x≤0.40) and LaMg{sub 3−x}Sn{sub 2} (0.33≤x≤0.78) are reported. The crystal structures of these intermetallics were determined by single crystal X-ray diffraction analysis and confirmed by Rietveld refinement of powder X-ray diffraction patterns of the corresponding samples. The La{sub 3}Mg{sub 4−x}Sn{sub 2+x} phase crystallizes in the hexagonal Zr{sub 3}Cu{sub 4}Si{sub 2} structure type (P6¯2m, hP9, Z=3, x=0.12(1), a=7.7974(7), c=4.8384(4) Å), which represents an ordered derivative of the hP9-ZrNiAl prototype, ubiquitous among equiatomic intermetallics. The LaMg{sub 3–x}Sn{sub 2} phase is the second representative of the trigonal LaMg{sub 3−x}Ge{sub 2}more » type, which is a superstructure of the LaLi{sub 3}Sb{sub 2} structure type (P3¯1c, hP34-0.12, Z=6, x=0.35(1), a=8.3222(9), c=14.9546(16) Å). The scheme describing the symmetry reduction/coloring with respect to the parent type is reported here with the purpose to discuss the LaMg{sub 3−x}Sn{sub 2} off-stoichiometry from the geometrical point of view. Structural relationships between the La–Mg–Sn ternary phases, including the already known equiatomic LaMgSn compound (oP12-TiNiSi), are presented in the framework of the AlB{sub 2}-related compounds family and discussed with the aid of group-subgroup relations in the Bärnighausen formalism. - Graphical abstract: Crystal structure of LaMg{sub 3−x}Sn{sub 2} viewed along the (001) direction together with the puckered layer of Mg and Sn atoms hosting Mg2, Mg3 and vacancy □. - Highlights: • Crystal structures of the new La{sub 3}Mg{sub 4−x}Sn{sub 2+x} and LaMg{sub 3−x}Sn{sub 2} phases were determined. • The off-stoichiometry of LaMg{sub 3−x}Sn{sub 2} was discussed from geometrical point of view. • Structural relations between the known La–Mg–Sn phases were established. • The studied compounds are related to the AlB{sub 2} type by symmetry reduction.« less

Crystallization of Chicken Egg-White Lysozyme from Ammonium Sulfate

NASA Technical Reports Server (NTRS)

Forsythe, Elizabeth L.; Snell, Edward H.; Pusey, Marc L.

1997-01-01

Chicken egg-white lysozyme was crystallized from ammonium sulfate over the pH range 4.0-7.8, with protein concentrations from 100 to 150 mg/ml. Crystals were obtained by vapor-diffusion or batch-crystallization methods. The protein crystallized in two morphologies with an apparent morphology dependence on temperature and protein concentration. In general, tetragonal crystals could be grown by lowering the protein concentration or temperature. Increasing the temperature or protein concentration resulted in the growth of orthorhombic crystals. Representative crystals of each morphology were selected for X-ray analysis. The tetragonal crystals belonged to the P4(sub 3)2(sub 1)2 space group with crystals grown at ph 4.4 having unit-cell dimensions of a = b = 78.7 1, c=38.6 A and diffracting to beyond 2.0 A. The orthorhombic crystals, grown at pH 4.8, were of space group P2(sub 1)2(sub 1)2 and had unit-cell dimensions of a = 30.51, b = 56.51 and c = 73.62 A.

Elastic Constants of Solids and Fluids with Initial Pressure via a Unified Approach Based on Equations-of-State

NASA Technical Reports Server (NTRS)

Cantrell, John H.

2014-01-01

The second and third-order Brugger elastic constants are obtained for liquids and ideal gases having an initial hydrostatic pressure p(sub 1). For liquids the second-order elastic constants are C(sub 11) = A + p(sub 1), C(sub 12) = A -- p(sub 1), and the third-order constants are C(sub 111) = --(B + 5A + 3p(sub 1)), C(sub 112) = --(B + A -- p(sub 1)), and C(sub 123) = A -- B -- p1, where A and B are the Beyer expansion coefficients in the liquid equation of state. For ideal gases the second order constants are C(sub 11) = p(sub 1)gamma + p9sub 1), C(sub 12) = p(sub 1)gamma -- p(sub 1), and the third-order constants are C(sub 111) = p(sub 1)(gamma(2) + 4gamma + 3), C(sub 112) = --p(sub 1)(gamma(2) -- 1), and C(sub 123) = --p(sub 1) (gamma(2) -- 2gamma + 1), where gamma is the ratio of specific heats. The inequality of C(sub 11) and C(sub 12) results in a nonzero shear constant C(sub 44) = (1/2)(C(sub 11) C(sub 12)) = p(sub 1) for both liquids and gases. For water at standard temperature and pressure the ratio of terms p1/A contributing to the second-order constants is approximately 4.3 x 10(-5). For atmospheric gases the ratio of corresponding terms is approximately 0.7. Analytical expressions that include initial stresses are derived for the material 'nonlinearity parameters' associated with harmonic generation and acoustoelasticity for fluids and solids of arbitrary crystal symmetry. The expressions are used to validate the relationships for the elastic constants of fluids.

Turbulence-induced relative velocity of dust particles. II. The bidisperse case

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Liubin; Padoan, Paolo; Scalo, John, E-mail: lpan@cfa.harvard.edu, E-mail: ppadoan@icc.ub.edu, E-mail: parrot@astro.as.utexas.edu

We extend our earlier work on turbulence-induced relative velocity between equal-size particles (Paper I, in this series) to particles of arbitrarily different sizes. The Pan and Padoan (PP10) model shows that the relative velocity between different particles has two contributions, named the generalized shear and acceleration terms, respectively. The generalized shear term represents the particles' memory of the spatial flow velocity difference across the particle distance in the past, while the acceleration term is associated with the temporal flow velocity difference on individual particle trajectories. Using the simulation of Paper I, we compute the root-mean-square relative velocity, (w {sup 2}){supmore » 1/2}, as a function of the friction times, τ{sub p1} and τ{sub p2}, of the two particles and show that the PP10 prediction is in satisfactory agreement with the data, confirming its physical picture. For a given τ{sub p1} below the Lagrangian correlation time of the flow, T{sub L}, (w {sup 2}){sup 1/2} as a function of τ{sub p2} shows a dip at τ{sub p2} ≅ τ{sub p1}, indicating tighter velocity correlation between similar particles. Defining a ratio f ≡ τ{sub p,{sub l}}/τ{sub p,{sub h}}, with τ{sub p,{sub l}} and τ{sub p,{sub h}} the friction times of the smaller and larger particles, we find that (w {sup 2}){sup 1/2} increases with decreasing f due to the generalized acceleration contribution, which dominates at f ≲ 1/4. At a fixed f, our model predicts that (w {sup 2}){sup 1/2} scales as τ{sub p,h}{sup 1/2} for τ{sub p,{sub h}} in the inertial range of the flow, stays roughly constant for T{sub L} ≲ τ{sub p,{sub h}} ≲ T{sub L}/f, and finally decreases as τ{sub p,h}{sup −1/2} for τ{sub p,{sub h}} >> T{sub L}/f. The acceleration term is independent of the particle distance, r, and reduces the r dependence of (w {sup 2}){sup 1/2} in the bidisperse case.« less

Structures of the Kplus and NH4 Forms of Linde J

DOE Office of Scientific and Technical Information (OSTI.GOV)

R Broach; R Kirchner

2011-12-31

The aluminosilicate zeolite Linde J has a unique topology. The structures of the K{sup +} and NH{sub 4}{sup +} forms of Linde J ([X{sub 2}(H{sub 2}O)][Si{sub 2}Al{sub 2}O{sub 8}] where X = K or NH{sub 4}) are identical except for slight cell size and positional differences due to NH{sub 4}{sup +} being larger than K{sup +} cations. The space group is P2{sub 1}2{sub 1}2{sub 1}. Cell dimensions are: K{sup +} Linde J, a = 9.4577(2) {angstrom}, b = 9.5573(2) {angstrom}, c = 9.9429(2) {angstrom}; NH{sub 4}{sup +} Linde J, a = 9.6324(4) {angstrom}, b = 9.6423(3) {angstrom}, c = 10.0230(3)more » {angstrom}. Zigzag 8-ring channels intersect giving a 2-D pore system.« less

Phase relations in the system In{sub 2}O{sub 3}-TiO{sub 2}-Fe{sub 2}O{sub 3} at 1100 C in air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, F.; Flores, M.J.R.; Kimizuka, N.

1999-04-01

Phase relations in the system In{sub 2}O{sub 3}-TiO{sub 2}-Fe{sub 2}O{sub 3} at 1100 C in air are determined by means of a classic quenching method. There exist In{sub 2}TiO{sub 5}, Fe{sub 2}TiO{sub 5} having a pseudo-Brookite-type phase and a new phase, In{sub 3}Ti{sub 2}FeO{sub 10} having a solid solution range from In{sub 2}O{sub 3}:TiO{sub 2}:Fe{sub 2}O{sub 3} = 4:6:1 to In{sub 2}O{sub 3}:TiO{sub 2}:Fe{sub 2}O{sub 3} = 0.384:0.464:0.152 (mole ratio) on the line InFeO{sub 3}-In{sub 2}Ti{sub 2}O{sub 7}. The crystal structures of In{sub 3}Ti{sub 2}FeO{sub 10} are pyrochlore related with a{sub m} = 5.9171 (5) {angstrom}, b{sub m} = 3.3696more » (3) {angstrom}, c{sub m} = 6.3885 (6) {angstrom}, and {beta} = 108.02 (1){degree} in a monoclinic crystal system at 1100 C, and a{sub 0} = 5.9089 (5) {angstrom}, b{sub 0} = 3.3679 (3) {angstrom}, and c{sub 0} = 12.130 (1) {angstrom} in an orthorhombic system at 1200 C. The relationship between the lattice constants of these phases and those of the cubic pyrochlore type are approximately as follows: a{sub m} = {minus}{1/4}a{sub p} + ({minus}{1/2})b{sub p} + ({minus}{1/4})c{sub p}, b{sub m} = {minus}{1/4}a{sub p} + (0)b{sub p} + ({1/4})c{sub p}, c{sub m} = {1/4}a{sub p} + ({minus}{1/2})b{sub p} + ({1/4})c{sub p} and {beta} = 109.47{degree} in the monoclinic system, and a{sub 0} = {minus}{1/4}a{sub p} + ({minus}{1/2})b{sub p} + ({minus}{1/4})c{sub p}, b{sub 0} = {minus}{1/4}a{sub p} + (0)b{sub p} + ({1/4})c{sub p}, and c{sub 0} = 2/3a{sub p} + ({minus}2/3)b{sub p} + (2/3)c{sub p} in the orthorhombic system, where a{sub p} = b{sub p} = c{sub p} = 9.90 ({angstrom}) are the lattice constants of In{sub 2}Ti{sub 2}O{sub 7} having the cubic pyrochlore type. All solid solutions of In{sub 3}Ti{sub 2}FeO{sub 10} have incommensurate structures with a periodicity of q {times} b{sup *} (q = 0.281--0.356) along the b{sup *} axis and the stoichiometric phase has q = 1/3. In FeO{sub 3} having a layered structure type is unstable between 750 and 1100 C.« less

Soft-hard acid-base interactions: probing coordination preferences of sulfur an selenium in mixed chalcophosphates in the family APbPS{sub 4-x}Se{sub x} (A = K, Rb, cs; x = 0-4).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rothenberger, A.; Morris, C.; Wang, H. H.

2009-01-01

The synthesis and structures of the three new compounds, KPbPS{sub 1.84}Se{sub 2.16} (1), RbPbPS{sub 1.56}Se{sub 2.43} (2), and CsPbPS{sub 3.46}Se{sub 0.54} (3), are reported. The solid state structures of 1-3 consist of two-dimensional layers of [PbP(S/Se){sub 4}] separated by alkali metal ions. The structure of 1 was solved in the orthorhombic space group Pna2{sub 1}. Compounds 2 and 3 possess the CsSmGeS{sub 4} structure type, crystallizing in the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}. All compounds were refined as racemic twins. All chalcogen sites around the tetrahedrally coordinated P atoms show mixed S/Se occupancy; however, there is a preferencemore » for Se binding to Pb ions and S binding to alkali ions. A {sup 31}P magic angle spinning NMR study on 1 suggests that, in mixed seleno-/thiophosphates, all of the anions [PS{sub x}Se{sub 4-x}]{sup 3-} (x = 0, 1, 2, 3, 4) are present. The different amount of sulfur and selenium present in KPbPS{sub 1.84}Se{sub 2.16} (1), RbPbPS{sub 1.56}Se{sub 2.43} (2), and CsPbPS{sub 3.46}Se{sub 0.54} (3) is reflected in the solid state absorption spectra from which bandgaps of 2.2 eV were determined for 1 and 2, and a blue-shift to 2.5 eV was observed because of the higher sulfur-content in 3. Thermogravimetric analysis experiments indicated that, upon heating, compound 1 decomposes forming PbSe and sulfur together with other unidentified products. A Raman spectrum of compound 1 showed more bands than are usually observed in seleno- or thiophosphate salts and is another indicator of the mixed seleno-/thiophosphate anions found in 1.« less

New observation and combined analysis of the Cs{sub 2} 0{sub g}{sup −}, 0{sub u}{sup +}, and 1{sub g} states at the asymptotes 6S{sub 1/2} + 6P{sub 1/2} and 6S{sub 1/2} + 6P{sub 3/2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Jie; Liu, Wenliang; Wu, Jizhou

2014-12-28

We report on new observations of the photoassociation spectroscopy of ultracold cesium molecules using a highly sensitive detection technique and a combined analysis with all observed electronic states. The technique is achieved by directly modulating the frequency of the trapping lasers of a magneto-optical trap. New observations of the Cs{sub 2}0{sub g}{sup −}, 0{sub u}{sup +}, and 1{sub g} states at the asymptotes 6S{sub 1/2} + 6P{sub 1/2} and 6S{sub 1/2} + 6P{sub 3/2} are reported. The spectral range is extended to the red detuning of 112 cm{sup −1} below the 6S{sub 1/2} + 6P{sub 3/2} dissociation limit. Dozens ofmore » vibrational levels of the ultracold Cs{sub 2}0{sub g}{sup −}, 0{sub u}{sup +}, and 1{sub g} states are observed for the first time. The available experimental binding energies of these states are analyzed simultaneously in a framework of the generalized LeRoy–Bernstein theory and the almost degenerate perturbation theory by Marinescu and Dalgarno [Phys. Rev. A: At., Mol., Opt. Phys. 52, 311 (1995)]. The unique atomic-related parameter c{sub 3} governing the dispersion forces of all the molecular states is estimated as (10.29 ± 0.05) a.u.« less

Well-aligned polycrystalline lanthanum silicate oxyapatite grown by reactive diffusion between solid La{sub 2}SiO{sub 5} and gases [SiO+1/2O{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fukuda, Koichiro, E-mail: fukuda.koichiro@nitech.ac.jp; Hasegawa, Ryo; Kitagawa, Takuya

2016-03-15

The c-axis-oriented polycrystalline lanthanum silicate oxyapatite, La{sub 9.48}(Si{sub 5.89}□{sub 0.11})O{sub 26} (□ denotes a vacancy in the Si site), was successfully prepared by the reactive diffusion between randomly grain-oriented La{sub 2}SiO{sub 5} polycrystal and [SiO+1/2O{sub 2}] gases at 1873 K in Ar atmosphere. The polycrystal was characterized using optical microscopy, scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, micro-Raman spectroscopy, X-ray diffractometry, and impedance spectroscopy. The crystal structure (space group P6{sub 3}/m) showed the deficiency of Si site at ca. 1.9%. The bulk oxide-ion conductivity along the grain-alignment direction steadily increased from 9.2 × 10{sup −3} to 1.17 ×more » 10{sup −2} S/cm with increasing temperature from 923 to 1073 K. The activation energy of conduction was 0.23(2) eV. - Graphical abstract: We have successfully prepared the highly c-axis-oriented polycrystalline La{sub 9.48}(Si{sub 5.89}□{sub 0.11})O{sub 26} by the reactive diffusion between randomly grain-oriented La{sub 2}SiO{sub 5} polycrystal and [SiO + 1/2O{sub 2}] gases at 1873 K in Ar atmosphere. The crystal structure (space group P6{sub 3}/m) showed the deficiency of Si site of ca. 1.9%. - Highlights: • The c-axis-oriented polycrystalline La{sub 9.48}(Si{sub 5.89}□{sub 0.11})O{sub 26} is successfully prepared. • Crystal structure of La{sub 9.48}(Si{sub 5.89}□{sub 0.11})O{sub 26} is determined by single-crystal XRD. • The polycrystal shows relatively high oxide ion conductivity along the common c-axis. • Reactive diffusion is successfully used for the preparation of grain-aligned ceramics.« less

Electron diffraction and high-resolution electron microscopy studies on layered Li{sub 2−δ}(Mn{sub 1−x}Co{sub x}){sub 1+δ}O{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujii, Hiroki, E-mail: fujii.hiroki@nims.go.jp; Ozawa, Kiyoshi; Mochiku, Takashi

2013-07-15

The structure of Li{sub 2}MnO{sub 3}–LiCoO{sub 2} solid solutions or Li{sub 2−δ}(Mn{sub 1−x}Co{sub x}){sub 1+δ}O{sub 3} (LMCO) which are promising lithium-battery cathodes was studied by high-resolution electron microscopy (HREM). X-ray diffraction (XRD) analyses indicate that Li{sub 1.6}Mn{sub 0.2}Co{sub 1.2}O{sub 3} and Li{sub 1.7}Mn{sub 0.4}Co{sub 0.9}O{sub 3} take a rhombohedral (R3-bar m space group) structure, whereas Li{sub 1.85}Mn{sub 0.7}Co{sub 0.45}O{sub 3} and Li{sub 1.95}Mn{sub 0.9}Co{sub 0.15}O{sub 3} take a monoclinic (C2/m) superstructure. HREM studies on those samples reveal that all of the observed crystallites in sample Li{sub 1.95}Mn{sub 0.9}Co{sub 0.15}O{sub 3} contain sharp stripe structures due to the planar defects alongmore » the c{sub h}-axis (stacking direction of the hexagonal close-packed planes) of parent rhombohedral R3-bar m cell. Such stripe structures become faint with increasing x, Co content. The origin of the planar defects is mainly attributed not to the different structures but to the different local orientations of the monoclinic LMCO. Local disordering of Li and (Mn,Co) in (Li,Mn,Co) planes is developed with increasing x and the structures are transformed from C2/m to R3-bar m. The alternative (Li,Mn,Co)-plane stacking structure, trigonal P3{sub 1}12 LMCO, was occasionally observed. However, only P3{sub 1}12 LMCO platelets with a thickness of a single unit cell were detected. - Graphical abstract: An HREM image for Li{sub 1.95}(Mn{sub 0.9}Co{sub 0.15})O{sub 3} and schematic drawings of C2/m and P3{sub 1}12 Li{sub 2}MnO{sub 3} projected along the various zone axes. Each projected unit cell is indicated by rectangles and parallelograms . - Highlights: • Li{sub 2−δ}(Mn{sub 1−x}Co{sub x}){sub 1+δ}O{sub 3} was studied by high-resolution electron microscopy (HREM). • HREM studies revealed a large amount of planar defects in C2/m Li{sub 1.95}Mn{sub 0.9}Co{sub 0.15}O{sub 3}. • The origin of the defects is the different local orientations of the C2/m platelets. • P3{sub 1}12 platelets with only single unit cell sequence were detected.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, Linda X., E-mail: lhong0812@gmail.com; Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY; Shankar, Viswanathan

We report our experience of establishing planning objectives to achieve dose coverage, conformity, and dose falloff for spine stereotactic body radiation therapy (SBRT) plans. Patients with spine lesions were treated using SBRT in our institution since September 2009. Since September 2011, we established the following planning objectives for our SBRT spine plans in addition to the cord dose constraints: (1) dose coverage—prescription dose (PD) to cover at least 95% planning target volume (PTV) and 90% PD to cover at least 99% PTV; (2) conformity index (CI)—ratio of prescription isodose volume (PIV) to the PTV < 1.2; (3) dose falloff—ratio ofmore » 50% PIV to the PTV (R{sub 50%}); (4) and maximum dose in percentage of PD at 2 cm from PTV in any direction (D{sub 2cm}) to follow Radiation Therapy Oncology Group (RTOG) 0915. We have retrospectively reviewed 66 separate spine lesions treated between September 2009 and December 2012 (31 treated before September 2011 [group 1] and 35 treated after [group 2]). The χ{sup 2} test was used to examine the difference in parameters between groups. The PTV V{sub 100%} {sub PD} ≥ 95% objective was met in 29.0% of group 1 vs 91.4% of group 2 (p < 0.01) plans. The PTV V{sub 90%} {sub PD} ≥ 99% objective was met in 38.7% of group 1 vs 88.6% of group 2 (p < 0.01) plans. Overall, 4 plans in group 1 had CI > 1.2 vs none in group 2 (p = 0.04). For D{sub 2cm}, 48.3% plans yielded a minor violation of the objectives and 16.1% a major violation for group 1, whereas 17.1% exhibited a minor violation and 2.9% a major violation for group 2 (p < 0.01). Spine SBRT plans can be improved on dose coverage, conformity, and dose falloff employing a combination of RTOG spine and lung SBRT protocol planning objectives.« less

Spectroscopic studies and structure of 3-methoxy-2 -[(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oezay, H.; Yildiz, M., E-mail: myildiz@comu.edu.tr; Uenver, H.

2013-01-15

The compound called 3-methoxy-2- [(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde has been synthesized from the reaction of 2-hydroxy-3-methoxybenzaldehyde with hexachlorocyclotriphosphazene. It has been characterized by elemental analysis, MS, IR, {sup 1}H NMR, {sup 13}C NMR, {sup 31}P NMR and UV-visible spectroscopic techniques. The structure of the title compound has been determind by X-ray analysis. Crystals are orthorhombic, space group P2{sub 1}2{sub 1}2{sub 1}, Z = 4, a = 7.705(1), b = 12.624(1), c = 17.825(2) A, R{sub 1} = 0.0390 and wR{sub 2} = 0.1074 [I > 2{sigma}(I)], respectively.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banerjee, Debasis; Borkowski, Lauren A.; Kim, Sun Jin

Two lithium-based metal-organic frameworks, Li{sub 2}(C{sub 14}H{sub 8}O{sub 4}) [Li{sub 2}(4,4'-BPDC) [1]; ULMOF-2, UL = ultralight; BPDC = biphenyldicarboxylate]; space group P2{sub 1}/c, a = 12.758(2) {angstrom}, b = 5.142(4) {angstrom}, c = 8.00(2) {angstrom}, {beta} = 97.23{sup o}, V = 520.6(14) {angstrom}{sup 3} and Li{sub 2}(C{sub 14}H{sub 8}O{sub 6}S) [Li{sub 2}(4,4'-SDB) [2]; ULMOF-3, UL = ultralight; SDB = sulfonyldibenzoate], space group P2{sub 1}/n, a = 5.5480(11) {angstrom}, b = 23.450(5) {angstrom}, c = 10.320(2) {angstrom}, {beta} = 96.47(3){sup o}, V = 1334.1(5) {angstrom}3, were synthesized. Compounds 1 and 2 were synthesized by solvothermal methods and were characterized using singlemore » crystal X-ray diffraction. Structure 1 consists of layers of two-dimensional antifluorite related LiO motif connected by BPDC linkers, whereas structure 2 is constructed by a combination of tetrameric lithium polyhedral clusters connected by the sulfonyldibenzoate linker. The frameworks are stable up to 575 and 500 C, respectively, under N{sub 2} atmosphere.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Na; Mu, Bao; Lv, Lei

Four new polyoxometalate(POM)–templated metal–organic frameworks based on flexible ligands, namely, [Cu{sub 6}(bip){sub 12}(PMo{sup VI}{sub 12}O{sub 40}){sub 2}(PMo{sup V}Mo{sup VI}{sub 11}O{sub 40}O{sub 2})]·8H{sub 2}O(1), [Cu{sup I}{sub 3}Cu{sup II}{sub 3}(bip){sub 12}(PMo{sup VI}{sub 12}O{sub 40}){sub 2}(PMo{sup V}{sub 12}O{sub 34})]·8H{sub 2}O(2), [Ni{sub 6}(bip){sub 12}(PMo{sup VI}{sub 12}O{sub 40})(PMo{sup VI}{sub 11}Mo{sup V}O{sub 40}){sub 2}]Cl·6H{sub 2}O(3), [Co{sup II}{sub 3}Co{sup III}{sub 2}(H{sub 2}bib){sub 2}(Hbib){sub 2}(PW{sub 9}O{sub 34}){sub 2}(H{sub 2}O){sub 6}]·6H{sub 2}O(4) (bip=1,3-bis(imidazolyl)propane, bib=1,4-bis(imidazolyl)butane) have been obtained under hydrothermal condition and characterized by single-crystal X-ray diffraction analyses, elemental analyses, and thermogravimetric (TG) analyses. The studies of single crystal X-ray indicate that compounds 1–3 crystallize in the trigonal space groupmore » P-3, and compound 4 crystallizes in the triclinic space group P-1. Compounds 1 and 3 represent 3D frameworks, and POMs as the guest molecules are incorporated into the cages which are composed of the ligands and metals, while compounds 2 and 4 show 3D frameworks by hydrogen bonds. This compounds provide new examples of host–guest compounds based on flexible bis(imidazole) ligands. In addition, the electrochemical property and the catalytic property of compound 1 have also been investigated. - Graphical abstract: Four inorganic–organic hybrid compounds based polyoxometalates (POMs) and flexible ligands, namely, have been obtained under hydrothermal conditions and characterized by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra, and thermogravimetric (TG) analyses. Compounds 1–3 are new examples of host–guest compounds based on flexible bis(imidazole) ligands and POMs as the guest molecules are incorporated into the cages which are composed of the ligands and metals. - Highlights: • Polyoxometalate–templated metal–organic frameworks have been prepared. • POMs as the guest molecules are incorporated into the cages. • The cages are flexibility based on flexible bis(imidazole) ligands.« less

Crystallization and preliminary X-ray diffraction analysis of a chitin-binding domain of hyperthermophilic chitinase from Pyrococcus furiosus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakamura, Tsutomu; Ishikawa, Kazuhiko; Hagihara, Yoshihisa

The expression, purification and preliminary X-ray diffraction studies of a chitin-binding domain of the chitinase from P. furiosus are reported. The crystallization and preliminary X-ray diffraction analysis of the chitin-binding domain of chitinase from a hyperthermophilic archaeon, Pyrococcus furiosus, are reported. The recombinant protein was prepared using an Escherichia coli overexpression system and was crystallized by the hanging-drop vapour-diffusion method. An X-ray diffraction data set was collected to 1.70 Å resolution. The crystal belonged to space group P4{sub 3}2{sub 1}2 or P4{sub 1}2{sub 1}2. The unit-cell parameters were determined to be a = b = 48.8, c = 85.0 Å.

Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of variants of monoamine oxidase from Aspergillus niger

DOE Office of Scientific and Technical Information (OSTI.GOV)

Atkin, Kate E.; Reiss, Renate; Turner, Nicholas J.

2008-03-01

Crystals of A. niger monoamine oxidase variants display P2{sub 1} or P4{sub 1}2{sub 1}2/P4{sub 3}2{sub 1}2 symmetry, with eight or two molecules in the asymmetric unit, respectively. Monoamine oxidase from Aspergillus niger (MAO-N) is an FAD-dependent enzyme that catalyses the conversion of terminal amines to their corresponding aldehydes. Variants of MAO-N produced by directed evolution have been shown to possess altered substrate specificity. Crystals of two of these variants (MAO-N-3 and MAO-N-5) have been obtained; the former displays P2{sub 1} symmetry with eight molecules per asymmetric unit and the latter has P4{sub 1}2{sub 1}2 or P4{sub 3}2{sub 1}2 symmetry andmore » two molecules per asymmetric unit. Solution of these structures will help shed light on the molecular determinants of improved activity and high enantioselectivity towards a broad range of substrates.« less

Optical cascade pumping of the 7P{sub 3/2} level in cesium atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kargapol'tsev, Sergei V; Velichansky, Vladimir L; Yarovitsky, Alexander V

2005-07-31

Doppler-free absorption spectra of resonance laser fields are studied upon two-stage excitation of cesium atoms according to the schemes 6S{sub 1/2{yields}}6P{sub 3/2{yields}}6D{sub 5/2} and 6S{sub 1/2{yields}}6P{sub 3/2{yields}}8S{sub 1/2}. The obtained experimental results are in qualitative agreement with the theory. In the case of weak absorption saturation, the width of resonances is mainly determined by two-photon transitions. The efficiencies of the two variants of two-stage excitation of the 7P{sub 3/2} level are compared. The possibility of fabrication of a gas laser operating on the 455-nm 7P{sub 3/2{yields}}6S{sub 1/2} transition with the optical depopulation of the lower operating level by an additionalmore » laser is discussed. (active media)« less

Crystal structure of triaquamaleatostrontium(II) monohydrate, [Sr(C{sub 4}H{sub 2}O{sub 4})(OH{sub 2}{sub 3}) {center_dot}] H{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diaz de Delgado, G.; Parra, P.P.; Briceno, A.

1995-05-01

(Sr(C{sub 4}H{sub 2}O{sub 4})(OH{sub 2}{sub 3}) {center_dot} H{sub 2}O is monoclinic, P2{sub 1}/n, with a = 11.476(2), b = 7.027(1), c = 12.344(2) {angstrom}, {beta} = 115.74(3){degrees}, V= 896.67 {angstrom}{sup 3}, Z = 4. The Sr atom is surrounded by nine oxygen atoms which come from four different maleate anions and three water molecules. The Sr-O distances range from 2.546(2) to 2.808(2) {angstrom}. The C-O distances are equal within the standard deviation 1.263(3) to 1.258(3) {angstrom}). In the maleate anion, the planes that contain the carboxylate groups form an angle of 74.44(9){degrees}. Both carboxylate groups deviate significantly from planarity. Themore » different coordination modes of the carboxylate group and the extensive hydrogen bonding present are responsible for the polymeric nature of the structure.« less

Crystallization and initial X-ray analysis of polyhydroxyalkanoate granule-associated protein from Aeromonas hydrophila

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Minglian; Li, Zhenguo; Zheng, Wei

The phasin PhaP{sub Ah} from A. hydrophila strain 4AK4 was crystallized using the hanging-drop vapour-diffusion method. Polyhydroxyalkanoate (PHA) granule-associated proteins (phasins) were discovered in PHA-accumulating bacteria. They play a crucial role as a structural protein during initial PHA-granule formation and granule growth and also serve as interfaces for granule stabilization in vivo. The phasin PhaP{sub Ah} from Aeromonas hydrophila strain 4AK4 was crystallized using the hanging-drop vapour-diffusion method. Single crystals were cryocooled for X-ray diffraction analysis. The phasin crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 80.8, b = 108.9, c = 134.4 Å.

Cyclopentadienylniobium and -molybdenum phosphorodithioate complexes. X-ray crystal structures of CpNbCl sub 3 (S sub 2 P(OPr sup i ) sub 2 ), CpNbCl(. mu. -Cl) sub 2 Nb(S sub 2 P(OPr sup i ) sub 2 )Cp, and cis-Cp prime Mo(CO) sub 2 (S sub 2 P(OPr sup i ) sub 2 )

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodward, S.; Riaz, U.; Curtis, M.D.

1990-10-01

Reaction of CpNbCl{sub 4} (Cp = {eta}-C{sub 5}H{sub 5}) with (Pr{sup i}O){sub 2}P(S)(SH) in the presence of NEt{sub 3} yields CpNbCl{sub 3}(S{sub 2}P(S{sub 2}Pr{sup i}){sub 2}) (1). Reduction of 1 with Na/Hg affords the Nb-Nb-bonded complex CpNbCl({mu}-Cl){sub 2}Nb(S{sub 2}P(OR){sub 2})Cp (2). In refluxing toluene, (Pr{sup i}O){sub 2}P(S)(SH) with (Cp{prime}Mo(CO){sub 3}){sub 2} (Cp{prime} = {eta}-C{sub 5}H{sub 4}Me) gives cis-Cp{prime}Mo(CO){sub 2}(S{sub 2}P(OPr{sup i}){sub 2}) (3). Oxidation of 3 with I{sub 2} affords Cp{prime}MoI{sub 2}(CO)(S{sub 2}P(OPr{sup i}){sub 2}) (4). The crystal structures of 1-3 are compared. For 1, triclinic, P{bar 1}, a = 7.122 (3) {angstrom}, b = 11.365 (4) {angstrom}, c =more » 12.532 (4) {angstrom}, {alpha} = 77.38 (3){degree}, {beta} = 89.08 (3){degree}, {gamma} = 72.87 (3){degree}, V = 944.5 (8) {angstrom}{sup 3}. For 2, triclinic, P{bar 1}, a = 7.251 (3) {angstrom}, b = 12.386 (5) {angstrom}, c = 13.988 (5) {angstrom}, {alpha} = 102.66 (3){degree}, {beta} = 103.56 (3){degree}, {gamma} = 94.66 (3){degree}, V = 1180.0 (8) {angstrom}{sup 3}, Z = 2. For 3, orthorhombic, Pbca, a = 12.703 (3) {angstrom}, b = 16.707 (4) {angstrom}, c = 18.398 (4) {angstrom}, V = 3904.4 (17) {angstrom}{sup 3}, Z = 8.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivenet, Murielle; Vigier, Nicolas; Roussel, Pascal

Six new layered uranyl vanadates (NH{sub 4}){sub 2}[(UO{sub 2}){sub 2}V{sub 2}O{sub 8}] (1), (H{sub 2}EN)[(UO{sub 2}){sub 2}V{sub 2}O{sub 8}] (2), (H{sub 2}DAP)[(UO{sub 2}){sub 2}V{sub 2}O{sub 8}] (3), (H{sub 2}PIP)[(UO{sub 2}){sub 2}(VO{sub 4}){sub 2}].0,8H{sub 2}O (4), (H{sub 2}DMPIP)[(UO{sub 2}){sub 2}V{sub 2}O{sub 8}] (5), (H{sub 2}DABCO)[(UO{sub 2}){sub 2}(VO{sub 4}){sub 2}] (6) were prepared from mild-hydrothermal reactions using 1,2-ethylenediamine (EN); 1,3-diaminopropane (DAP); piperazine (PIP); 1-methylpiperazine (MPIP); 1,4-diazabicyclo[2,2,2]octane (DABCO). The structures of 1, 4, 5 and 6 were solved using single-crystal X-ray diffraction data while the structural models of 2 and 3 were established from powder X-ray diffraction data. In compounds 1, 2, 3more » and 5, the uranyl-vanadate layers are built from dimers of edge-shared UO{sub 7} pentagonal bipyramids and dimers of edge-shared VO{sub 5} square pyramids further connected through edge-sharing. In 1 and 3, the layers are identical to that occurring in the carnotite group of uranyl-vanadates. In 2 and 5, the V{sub 2}O{sub 8} dimers differ in orientation leading to a new type of layer. The layers of compound 4 and 6 are built from chains of edge-shared UO{sub 7} pentagonal bipyramids connected by VO{sub 4} tetrahedra and are of uranophane-type anion topology. For the six compounds, the ammonium or organoammonium cation resides in the space between the inorganic layers. Crystallographic data: 1 monoclinic, space group P2{sub 1}/c with a=6.894(2), b=8.384(3), c=10.473(4) A and {beta}=106.066(5){sup o}, 2 monoclinic, space group P2{sub 1}/a with a=13.9816(6), b=8.6165(3), c=10.4237(3) A and {gamma}=93.125(3){sup o}, 3 orthorhombic, space group Pmcn with a=14.7363(8), b=8.6379(4) and c=10.4385(4) A, 4 monoclinic, space group C2/m with a=15.619(2), b=7.1802(8), c=6.9157(8) A and {beta}=101.500(2){sup o}, 5 monoclinic, space group P2{sub 1}/b with a=9.315(2), b=8.617(2), c=10.5246(2) A and {gamma}=114.776(2){sup o}, 6 monoclinic, space group C2/m with a=17.440(2), b=7.1904(9), c=6.8990(8) A and {beta}=98.196(2){sup o}. - Graphical abstract: The three types of layer in layered uranyl-vanadates using diamine as a structure-directing agent.« less

Crystallization and preliminary X-ray crystallographic studies of Drep-3, a DFF-related protein from Drosophila melanogaster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Hyun Ho; Tookes, Hansel Emory; Wu, Hao, E-mail: haowu@med.cornell.edu

2006-06-01

The D. melanogaster Drep-3 protein has been crystallized. Crystals were obtained at 293 K that diffracted to 2.8 Å resolution and belonged to space group P2{sub 1}2{sub 1}2{sub 1}. During apoptosis, DNA fragmentation is mainly mediated by the caspase-activated DFF40 nuclease. DFF40 exists as a heterodimeric complex with its inhibitor DFF45. Upon apoptosis induction, DFF45 is cleaved by caspases to allow DFF40 activation. Drep-3 is a recently identified regulator of the DFF40 system in Drosophila melanogaster. Here, Drep-3 was expressed with a C-terminal His tag in Escherichia coli and the protein was purified to homogeneity. Multi-angle light-scattering analysis showed thatmore » Drep-3 is a homotetramer in solution. Native and selenomethionine-substituted Drep-3 proteins were crystallized at 293 K and X-ray diffraction data were collected to 2.8 and 3.0 Å resolution, respectively. The crystals belong to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 56.9, b = 125.4, c = 168.7 Å. The asymmetric unit is estimated to contain one homotetramer.« less

Thermodynamic properties of {Delta}H{sub f 298}{degree}, S{sub 298}{degree}, and C{sub p}(T) for 2-fluoro-2-methylpropane, {Delta}H{sub f 298}{degree} of fluorinated ethanes, and group additivity for fluoroalkanes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamada, Takahiro; Bozzelli, J.W.

1999-09-09

G2(MP2) composite calculations are performed to obtain thermodynamic properties ({Delta}H{sub f 298}{degree}, S{sub 298}{degree} and C{sub p}(T)'s) of 2-fluoro-2-methylpropane. {Delta}H{sub f 298}{degree} is calculated from the G2(MP2) calculated enthalpy of reaction ({Delta}H{sub rxn 298}{degree}) and use of isodesmic reactions. Standard entropy (S{sub 298}{degree} in cal/(mol{center{underscore}dot}K)) and heat capacities (C{sub p}(T)'s in cal/(mol{center{underscore}dot}K)) are calculated using the rigid-rotor--harmonic-oscillator approximation with direct integration over energy levels of the intermolecular rotation potential energy curve. These thermodynamic properties are used to estimate data for the C/C3/F group. Enthalpies of formation ({Delta}H{sub f 298}{degree} in kcal/mol) for 1,2-difluoroethane ({minus}102.7), 1,1,2-trifluoroethane ({minus}156.9), 1,1,2,2- and 1,1,1,2-tetrafluoroethane (209.6more » and 213.3), and pentafluoroethane ({minus}264.1), are calculated using total energies obtained from G2(MP2) composite ab initio methods. Isodesmic reactions with existing literature values of {Delta}H{sub f 298}{degree} for ethane, 1-fluoroethane, 1,1-difjuoroethane and 1,1,1-trifluoroethane are used. Fluorine/fluorine interaction terms, F/F, 2F/F, 3F/F, 2F/2F, and 3F/2F, where ``/'' indicates interaction for alkane compounds, for {Delta}H{sub f 298}{degree} are reevaluated based on {Delta}H{sub f 298}{degree} of the above five fluoroethanes. Thermodynamic properties ({Delta}H{sub f 298}{degree}, S{sub 298}{degree} and C{sub p}(T)'s (300 {le} T/K {le} 1500)) for fluorinated carbon groups, C/C3F, C/C2/F/H, C/C2/F2, are calculated using data from ab initio methods and existing literature data. Fluorine-methyl (alkyl) group additivity corrections for gauche interactions are also evaluated.« less

The new silver borate Ag{sub 3}B{sub 5}O{sub 9}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sohr, Gerhard; Falkowski, Viktoria; Huppertz, Hubert, E-mail: hubert.huppertz@uibk.ac.at

2015-05-15

Single crystals of Ag{sub 3}B{sub 5}O{sub 9} were obtained via high-pressure synthesis at 3 GPa and 600 °C, using a Walker-type multianvil high-pressure device. Ag{sub 3}B{sub 5}O{sub 9} crystalizes with a=674.7(2), b=943.5(2), c=1103.5(2) pm, V=0.7025(2) nm{sup 3}, and Z=4 in the noncentrosymmetric space group P2{sub 1}2{sub 1}2{sub 1} (no. 19). The orthorhombic structure was refined from 3740 independent reflections with R1=0.0496 and wR2=0.587 (all data). It is built up from infinite corner-sharing chains of BO{sub 4} tetrahedra along the a axis, which are interconnected by BO{sub 3} groups to form a network. In the structure, three crystallographically independent sites aremore » occupied with Ag{sup +} cations exhibiting argentophillic interactions. The synthetic conditions as well as the results of the single crystal structure analysis are presented. - Graphical abstract: Noncentrosymmetric silver borate: During investigations in the system Ag–B–O, a new noncentrosymmetric silver borate Ag{sub 3}B{sub 5}O{sub 9} was discovered. The new structure type is built up from corner-sharing BO{sub 3} and BO{sub 4} groups, forming a network. Argentophillic interactions are clearly indicated by the Ag{sup +}⋯Ag{sup +} distances present in the structure. - Highlights: • A noncentrosymmetric borate Ag{sub 3}B{sub 5}O{sub 9} is accessible via high-pressure synthesis. • Ag{sub 3}B{sub 5}O{sub 9} is the second high-pressure silver borate. • Ag{sup +}⋯Ag{sup +} distances in Ag3B5O9 clearly indicate the presence of argentophillic interactions.« less

Crystallization and preliminary X-ray analysis of CTP:phosphoethanolamine cytidylyltransferase (ECT) from Saccharomyces cerevisiae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohtsuka, Jun; Nagata, Koji; Lee, Woo Cheol

2006-10-01

CTP:phosphoethanolamine cytidylyltransferase from S. cerevisiae has been expressed, purified and crystallized. CTP:phosphoethanolamine cytidylyltransferase (ECT) is the enzyme that catalyzes the conversion of phosphoethanolamine to CDP-ethanolamine in the phosphatidylethanolamine-biosynthetic pathway (Kennedy pathway). ECT from Saccharomyces cerevisiae was crystallized by the sitting-drop vapour-diffusion method using PEG 4000 as precipitant. The crystals diffracted X-rays from a synchrotron-radiation source to 1.88 Å resolution. The space group was assigned as primitive tetragonal, P4{sub 1}2{sub 1}2 or P4{sub 3}2{sub 1}2, with unit-cell parameters a = b = 66.3, c = 150.8 Å. The crystals contain one ECT molecule in the asymmetric unit (V{sub M} = 2.2more » Å{sup 3} Da{sup −1}), with a solvent content of 43%.« less

Absolute configurations of organometallic compounds. III. Structure and absolute configuration of the square-pyramidal complex ((+)/sub 579/-(C/sub 5/H/sub 5/)Mo(CO)/sub 2/(NN*))PF/sub 6/(NN* = Schiff base derived from pyridine-2-carbaldehyde and (S)-(-)-. cap alpha. -phenylethylamine)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernal, I.; LaPlaca, S.J.; Korp, J.

The structure of (+)/sub 579/-(eta/sup 5/-C/sub 5/H/sub 5/Mo(CO)/sub 2/(NN*))PF/sub 6/ with NN* = the Schiff base derived from pyridine-2-carbaldehyde and (S)-(--)-..cap alpha..-phenylethylamine was determined using standard single-crystal x-ray diffraction methods. The absolute configuration was determined by refinement of the data using the anomalous scattering contributions of Mo and P to a final R(F) = 0.056 for 2634 independent reflections having I greater than 3 sigma (I). The substance crystallizes in the space group P2/sub 1/2/sub 1/2/sub 1/ with unit cell dimensions of a = 12.249 (4), b = 9.236 (3), and c = 20.692 (9) A and Z = 4more » molecules/unit cell. The square-pyramidal coordination of the Mo atom is defined by two carbonyl carbons and two Schiff base nitrogens occupying the four basal plane sites and the five carbons of the eta/sup 5/-C/sub 5/H/sub 5/ ligand in the axial position. The Mo--ligand distances and the bond lengths and angles within the ligands are normal and compare closely with those of recent structure determinations of comparable precision. The Mo atom is 0.95 A above the plane formed by the four basal plane ligands. The conformation of the (S)-..cap alpha..-phenylethyl group with respect to the ligand plane, defined by the pyridine ring, the imine system, and the Mo atom, is discussed. The configuration at the metal atom in the (+)/sub 579/ isomer is specified as (S). The PF/sub 6//sup -/ anion executes large amplitude torsional motion in the lattice, as is commonly the case for this anion when not hydrogen bonded.« less

Crystallization and preliminary X-ray analysis of a protease inhibitor from the latex of Carica papaya

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azarkan, Mohamed; Garcia-Pino, Abel; Dibiani, Rachid

2006-12-01

The Kunitz-type trypsin/chymotrypsin inhibitor isolated from C. papaya latex has been crystallized using the hanging-drop vapour-diffusion method. Two different crystal forms are observed, diffracting to 2.6 and 1.7 Å. A Kunitz-type protease inhibitor purified from the latex of green papaya (Carica papaya) fruits was crystallized in the presence and absence of divalent metal ions. Crystal form I, which is devoid of divalent cations, diffracts to a resolution of 2.6 Å and belongs to space group P3{sub 1} or P3{sub 2}. This crystal form is a merohedral twin with two molecules in the asymmetric unit and unit-cell parameters a = bmore » = 74.70, c = 78.97 Å. Crystal form II, which was grown in the presence of Co{sup 2+}, diffracts to a resolution of 1.7 Å and belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 44.26, b = 81.99, c = 140.89 Å.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Chen; Pinkerton, Frederick E.; Herbst, Jan F.

New magnetic materials containing cerium, iron, and small additions of a third element are disclosed. These materials comprise compounds Ce(Fe.sub.12-xM.sub.x) where x=1-4, having the ThMn.sub.12 tetragonal crystal structure (space group I4/mmm, #139). Compounds with M=B, Al, Si, P, S, Sc, Co, Ni, Zn, Ga, Ge, Zr, Nb, Hf, Ta, and W are identified theoretically, and one class of compounds based on M=Si has been synthesized. The Si cognates are characterized by large magnetic moments (4.pi.M.sub.s greater than 1.27 Tesla) and high Curie temperatures (264.ltoreq.T.sub.c.ltoreq.305.degree. C.). The Ce(Fe.sub.12-xM.sub.x) compound may contain one or more of Ti, V, Cr, and Mo inmore » combination with an M element. Further enhancement in T.sub.c is obtained by nitriding the Ce compounds through heat treatment in N.sub.2 gas while retaining the ThMn.sub.12 tetragonal crystal structure; for example CeFe.sub.10Si.sub.2N.sub.1.29 has T.sub.c=426.degree. C.« less

Synthesis and X-ray crystal structures of heavy-metal complexes of 1,5,9,13-tetrathiacyclohexadecane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Setzer, W.N.; Tang, Yaping; Grant, G.J.

1991-09-18

Heavy-metal complexes of the macrocyclic tetrathioether 1,5,9,13-tetrathiacyclohexadecane (16S4) have been prepared by reaction of the ligand with the appropriate heavy-metal salts. The complexes [Hg(16S4)](ClO[sub 4])[sub 2], [Cd(16S4)](ClO[sub 4])[sub 2], and (16S4)(HgCl[sub 2])[sub 2] have been synthesized and characterized. Single-crystal X-ray structural studies have been carried out on [Hg(16S4)](ClO[sub 4])[sub 2] and [Cd(16S4)](ClO[sub 4])[sub 2]. Crystal data for [Hg(16S4)](ClO[sub 4])[sub 2]: C[sub 12]H[sub 24]S[sub 4]HgCl[sub 2]O[sub 8]; monoclinic space group C2/c; a = 10.033 (3), b = 13.421 (4), c = 15.960 (4) [angstrom]; [beta] = 96.48 (2)[degree]; Z = 4; R = 0.051. Crystal data for [Cd(16S4)](ClO[sub 4])[sub 2]: C[submore » 12]H[sub 24]S[sub 4]CdCl[sub 2]O[sub 8]; triclinic space group P[bar I]; a = 8.346 (2), b = 8.349 (3), c = 8.688 (2) [angstrom]; [alpha] = 69.87 (2), [beta] = 68.97 (2), [gamma] = 82.33 (2)[degree]; Z = 1; R = 0.043. Molecular mechanics calculations have been carried out on the 16S4 ligand, and the lowest energy conformation is a quadrangular [4444] conformation with the sulfur atoms occupying the corners (exodentate) of the quadrangle.« less

Method of making an icosahedral boride structure

DOEpatents

Hersee, Stephen D.; Wang, Ronghua; Zubia, David; Aselage, Terrance L.; Emin, David

2005-01-11

A method for fabricating thin films of an icosahedral boride on a silicon carbide (SiC) substrate is provided. Preferably the icosahedral boride layer is comprised of either boron phosphide (B.sub.12 P.sub.2) or boron arsenide (B.sub.12 As.sub.2). The provided method achieves improved film crystallinity and lowered impurity concentrations. In one aspect, an epitaxially grown layer of B.sub.12 P.sub.2 with a base layer or substrate of SiC is provided. In another aspect, an epitaxially grown layer of B.sub.12 As.sub.2 with a base layer or substrate of SiC is provided. In yet another aspect, thin films of B.sub.12 P.sub.2 or B.sub.12 As.sub.2 are formed on SiC using CVD or other vapor deposition means. If CVD techniques are employed, preferably the deposition temperature is above 1050.degree. C., more preferably in the range of 1100.degree. C. to 1400.degree. C., and still more preferably approximately 1150.degree. C.

Crystallization of the C-terminal domain of the addiction antidote CcdA in complex with its toxin CcdB

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buts, Lieven; De Jonge, Natalie; Loris, Remy, E-mail: reloris@vub.ac.be

2005-10-01

The CcdA C-terminal domain was crystallized in complex with CcdB in two crystal forms that diffract to beyond 2.0 Å resolution. CcdA and CcdB are the antidote and toxin of the ccd addiction module of Escherichia coli plasmid F. The CcdA C-terminal domain (CcdA{sub C36}; 36 amino acids) was crystallized in complex with CcdB (dimer of 2 × 101 amino acids) in three different crystal forms, two of which diffract to high resolution. Form II belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 37.6, b = 60.5, c = 83.8 Å and diffracts to 1.8more » Å resolution. Form III belongs to space group P2{sub 1}, with unit-cell parameters a = 41.0, b = 37.9, c = 69.6 Å, β = 96.9°, and diffracts to 1.9 Å resolution.« less

Crystal structure of Ca{sub 12}Al{sub 14}O{sub 32}Cl{sub 2} and luminescence properties of Ca{sub 12}Al{sub 14}O{sub 32}Cl{sub 2}:Eu{sup 2+}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iwata, Tomoyuki; Haniuda, Masahide; Fukuda, Koichiro

2008-01-15

The crystal structure of Ca{sub 12}Al{sub 14}O{sub 32}Cl{sub 2} was determined from laboratory X-ray powder diffraction data (CuK{alpha}{sub 1}) using the Rietveld method, with the anisotropic displacement parameters being assigned for all atoms. The crystal structure is cubic (space group I4-bar 3d, Z=2) with lattice dimensions a=1.200950(5) nm and V=1.73211(1) nm{sup 3}. The reliability indices calculated from the Rietveld method were R{sub wp}=8.48% (S=1.21), R{sub p}=6.05%, R{sub B}=1.27% and R{sub F}=1.01%. The validity of the structural model was verified by the three-dimensional electron density distribution, the structural bias of which was reduced as much as possible using the maximum-entropy methods-basedmore » pattern fitting (MPF). The reliability indices calculated from the MPF were R{sub B}=0.75% and R{sub F}=0.56%. In the structural model there are one Ca site, two Al sites, two O sites and one Cl site. This compound is isomorphous with Ca{sub 12}Al{sub 10.6}Si{sub 3.4}O{sub 32}Cl{sub 5.4}. Europium-doped sample Ca{sub 12}Al{sub 14}O{sub 32}Cl{sub 2}:Eu{sup 2+} was prepared and the photoluminescence properties were presented. The excitation spectrum consisted of two wide bands, which were located at about 268 and 324 nm. The emission spectrum, when excited at 324 nm, resulted in indigo light with a peak at about 442 nm. - Graphical abstract: A portion of the crystal structure of Ca{sub 12}Al{sub 14}O{sub 32}Cl{sub 2} showing eight-membered AlO{sub 4} rings and Ca-Cl-Ca unit.« less

UTa{sub 2}O(S{sub 2}){sub 3}Cl{sub 6}: A ribbon structure containing a heterobimetallic 5d-5f M{sub 3} cluster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wells, Daniel M.; Chan, George H.; Ellis, Donald E.

2010-02-15

A new solid-state compound containing a heterobimetallic cluster of U and Ta, UTa{sub 2}O(S{sub 2}){sub 3}Cl{sub 6}, has been synthesized and its structure has been characterized by single-crystal X-ray diffraction methods. UTa{sub 2}O(S{sub 2}){sub 3}Cl{sub 6} was synthesized from UCl{sub 4} and Ta{sub 1.2}S{sub 2} at 883 K. The O is believed to have originated in the Ta{sub 1.2}S{sub 2} reactant. The compound crystallizes in the space group P1-bar of the triclinic system. The structure comprises a UTa{sub 2} unit bridged by mu{sub 2}-S{sub 2} and mu{sub 3}-O groups. Each Ta atom bonds to two mu{sub 2}-S{sub 2}, the mu{submore » 3}-O, and two terminal Cl atoms. Each U atom bonds to two mu{sub 2}-S{sub 2}, the mu{sub 3}-O, and four Cl atoms. The Cl atoms bridge in pairs to neighboring U atoms to form a ribbon structure. The bond distances are normal and are consistent with formal oxidation states of +IV/+V/-II/-I/-I for U/Ta/O/S/Cl, respectively. The optical absorbance spectrum displays characteristic transition peaks near the absorption edge. Density functional theory was used to assign these peaks to transitions between S{sup 1-} valence-band states and empty U 5f-6d hybrid bands. Density-of-states analysis shows overlap between Ta 5d and U bands, consistent with metal-metal interactions. - The UTa2O(S2)3Cl6 cluster with completed coordination sphere around uranium« less

Synthesis of Ruthenium Carbonyl Complexes with Phosphine or Substituted Cp Ligands, and Their Activity in the Catalytic Deoxygenation of 1,2-Propanediol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bullock, R.M.; Ghosh, P.; Fagan, P.J.

2009-07-20

A ruthenium hydride with a bulky tetra-substituted Cp ligand, (Cp{sup iPr{sub 4}})Ru(CO){sub 2}H (Cp{sup iPr{sub 4}} = C{sub 5}(i-C{sub 3}H{sub 7}){sub 4}H) was prepared from the reaction of Ru{sub 3}(CO){sub 12} with 1,2,3,4-tetraisopropylcyclopentadiene. The molecular structure of (Cp{sup iPr{sub 4}})Ru(CO){sub 2}H was determined by X-ray crystallography. The ruthenium hydride complex (C{sub 5}Bz{sub 5})Ru(CO){sub 2}H (Bz = CH{sub 2}Ph) was similarly prepared. The Ru-Ru bonded dimer, [(1,2,3-trimethylindenyl)Ru(CO){sub 2}]{sub 2}, was produced from the reaction of 1,2,3-trimethylindene with Ru{sub 3}(CO){sub 12}, and protonation of this dimer with HOTf gives {l_brace}[(1,2,3-trimethylindenyl)Ru(CO){sub 2}]{sub 2}-({mu}-H){r_brace}{sup +}OTf{sup -}. A series of ruthenium hydride complexes CpRu(CO)(L)H [Lmore » = P(OPh){sub 3}, PCy{sub 3}, PMe{sub 3}, P(p-C{sub 6}H{sub 4}F){sub 3}] were prepared by reaction of Cp(CO){sub 2}RuH with added L. Protonation of (Cp{sup iPr{sub 4}})Ru(CO){sub 2}H, Cp*Ru(CO){sub 2}H, or CpRu(CO)[P-(OPh){sub 3}]H by HOTf at -80 C led to equilibria with the cationic dihydrogen complexes, but H{sub 2} was released at higher temperatures. Protonation of CpRu[P(OPh){sub 3}]{sub 2}H with HOTf gave an observable dihydrogen complex, {l_brace}CpRu[P-(OPh){sub 3}]{sub 2}({eta}{sup 2}-H{sub 2}){r_brace}+OTf{sup -} that was converted at -20 C to the dihydride complex {l_brace}CpRu[P(OPh){sub 3}]{sub 2}(H){sub 2}{r_brace}{sup +}OTf{sup -}. These Ru complexes serve as catalyst precursors for the catalytic deoxygenation of 1,2-propanediol to give n-propanol. The catalytic reactions were carried out in sulfolane solvent with added HOTf under H{sub 2} (750 psi) at 110 C.« less

Synthesis, crystal structure, and vibrational spectroscopic and UV-visible studies of Cs{sub 2}MnP{sub 2}O{sub 7}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaoua, Saida; Krimi, Saida; Pechev, Stanislav

2013-02-15

A new member of the A{sub 2}MP{sub 2}O{sub 7} diphosphate family, Cs{sub 2}MnP{sub 2}O{sub 7}, has been synthesized and structurally characterized. The crystal structure was determined by single crystal X-Ray diffraction. Cs{sub 2}MnP{sub 2}O{sub 7} crystallizes in the orthorhombic system, space group Pnma ( Music-Sharp-Sign 62), with the unit cell parameters a=16.3398(3), b=5.3872(1), c=9.8872(2) A, Z=4 and V=870.33(3) A{sup 3}. The structure parameters were refined to a final R{sub 1}/wR{sub 2}=0.0194/0.0441 for 1650 observed reflections. The 2D framework of Cs{sub 2}MnP{sub 2}O{sub 7} structure consists of P{sub 2}O{sub 7} and MnO{sub 5} units. The corner-shared MnO{sub 5} and P{sub 2}O{submore » 7} units are alternately arranged along the b axis to form [(MnO)P{sub 2}O{sub 7}]{sub {infinity}} chains. These chains are interconnected by an oxygen atom to form sheets parallel to the (b, c) plane. The cesium atoms are located between the sheets in 9- and 10-fold coordinated sites. The infrared and Raman vibrational spectra have been investigated. A factor group analysis leads to the determination of internal modes of (P{sub 2}O{sub 7}) groups. UV-visible spectrum consists of weak bands, between 340 and 700 nm, assigned to the forbidden d-d transitions of Mn{sup 2+} ion, and of a strong band around 250 nm, attributed to the O--Mn charge transfer. - Graphical abstract: Structure of Cs{sub 2}MnP{sub 2}O{sub 7}: The 2D structure of Cs{sub 2}MnP{sub 2}O{sub 7} is built from P{sub 2}O{sub 7} diphosphate groups and MnO{sub 5} square pyramids which share corners and form [(MnO)P{sub 2}O{sub 7}]{sub {infinity}} chains along b axis. These chains are interconnected by an oxygen atom to form wavy (MnP{sub 2}O{sub 7}){sup 2-} sheets parallel to the (b, c) plane. The cesium ions are located between these sheets in the inter-layers space, in zigzag positions. Highlights: Black-Right-Pointing-Pointer A new diphosphate, Cs{sub 2}MnP{sub 2}O{sub 7}, has been synthesized and structurally characterized. Black-Right-Pointing-Pointer The structure consists of a 2D framework built up from (MnP{sub 2}O{sub 7}) sheets. Black-Right-Pointing-Pointer The sheets consist of [(MnO)P{sub 2}O{sub 7}]{sub {infinity}} chains formed by P{sub 2}O{sub 7} units and MnO{sub 5} square pyramids. Black-Right-Pointing-Pointer A factor group analysis leads to the determination of internal modes of (P{sub 2}O{sub 7}) groups. Black-Right-Pointing-Pointer UV-visible spectrum consists bands assigned to d-d transitions of Mn{sup 2+} ion and to O--Mn CT.« less

Synthesis and reactions of nickel and palladium carbon-bound enolate complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burkhardt, E.R.; Bergman, R.G.; Heathcock, C.H.

1990-01-01

Nickel and palladium carbon-bound enolates of the general formula {eta}{sup 5}-C{sub 5}R{sub 5}(Ph{sub 3}P)MCHR{prime}COR{double prime} (R = H, CH{sub 3}; R{prime} = H, CH{sub 3}; R{double prime} = t-Bu, Ph, O-t-Bu) were prepared. Cp{sup *}(Ph{sub 3}P)NiCH{sub 2}CO{sub 2}-t-Bu (1e) was characterized by X-ray diffraction. Compound 1e crystallizes in the monoclinic space group P2{sub 1}/n with unit-cell dimensions a = 13.6110 (20) {angstrom}, b = 12.7454 (13) {angstrom}, c = 17.8571 (23) {angstrom}, {beta} = 105.544 (11){degree}, Z = 4, observed data 4,091, R = 4.53%, and R{sub w} = 4.19%. Reactions of these nickel and palladium enolates with aldehydes andmore » other electrophilic reagents were examined. The nickel ketone enolates were shown to react with 2 equiv of benzaldehyde to deliver products resulting from a Tischtschenko-type oxidation/reduction process. Cp(Ph{sub 3}P)NiCH{sub 2}CO-t-Bu reacts with phosphines (L) to yield paramagnetic nickel(I) complexes of general formula Cp(L){sub 2}Ni.« less

Purification, crystallization and preliminary X-ray analysis of the glucosamine-6-phosphate N-acetyltransferase from human liver

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Juan; Zhou, Yan-Feng; Li, Lan-Fen

2006-11-01

Glucosamine-6-phosphate N-acetyltransferase from human liver was expressed, purified and crystallized. Diffraction data have been collected to 2.6 Å resolution. Glucosamine-6-phosphate N-acetyltransferase from human liver, which catalyzes the transfer of an acetyl group from acetyl coenzyme A (AcCoA) to the primary amine of d-glucosamine 6-phosphate to form N-acetyl-d-glucosamine 6-phosphate, was expressed in a soluble form from Escherichia coli strain BL21 (DE3). The protein was purified to homogeneity using Ni{sup 2+}-chelating chromatography followed by size-exclusion chromatography. Crystals of the protein were obtained by the hanging-drop vapour-diffusion method and diffracted to 2.6 Å resolution. The crystals belonged to space group P4{sub 1}2{sub 1}2more » or P4{sub 3}2{sub 1}2, with unit-cell parameters a = b = 50.08, c = 142.88 Å.« less

Fe{sub 2.5}[BP{sub 2}O{sub 7}(OH){sub 2}][PO{sub 3}(OH)][PO{sub 3}(O{sub 0.5}OH{sub 0.5})] · H{sub 2}O, a new phosphate-borophosphate with a microporous structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belokoneva, E. L., E-mail: elbel@geol.msu.ru; Dimitrova, O. V.

2015-05-15

A new phosphate-borophosphate Fe{sub 2.5}{sup 3+}[BP{sub 2}O{sub 7}(OH){sub 2}][PO{sub 3}(OH)][PO{sub 3}(O{sub 0.5}OH{sub 0.5})] · H{sub 2}O, space group P12{sub 1}/n, is obtained under hydrothermal conditions. Blocks (Fe{sup 3+}(PO{sub 4}){sub 6}){sup 15−} consisting of vertex-sharing (Fe1,Fe2)O{sub 6} octahedra and six PO{sub 4} tetrahedra are distinguished in the structure of the new phase, which was determined without preliminary knowledge of the chemical formula. Such blocks are known for many phosphates (borophosphates), germanates, gallates, and silicates. Blocks form layers connected by BO{sub 4} tetrahedra into a framework with large pores reaching ∼9.5 Å, which are occupied by water molecules. The out-of-layer octahedral positionmore » of the Fe3 atom is split and occupied statistically. The anion radical is characterized as a phosphate-borophosphate: it consists of two isolated PO4 tetrahedra and a borophosphate soro group [BP{sub 2}O{sub 7}(OH){sub 2}] first found in NaIn[BP{sub 2}O{sub 8}(OH)]. A layer of octahedra is characterized by higher local symmetry corresponding to the orthorhombic group Pm2{sub 1}n.« less

New ternary phosphides and arsenides. Syntheses, crystal structures, physical properties of Eu{sub 2}ZnP{sub 2}, Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jian; Xia, Sheng-Qing, E-mail: shqxia@sdu.edu.cn; Tao, Xu-Tang

2013-09-15

Three new europium pnictides Eu{sub 2}ZnP{sub 2}, Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3} have been synthesized and their structures were determined by single-crystal X-ray diffraction. Eu{sub 2}ZnP{sub 2} is isotypic with Yb{sub 2}CdSb{sub 2} (Cmc2{sub 1} (No. 36); cell parameters a=4.1777(7) Å, b=15.925(3) Å, c=7.3008(12) Å), while the latter two compounds crystallize with the Ba{sub 2}Cd{sub 2}Sb{sub 3} structure type (C2/m (No. 12); cell parameters a=15.653(5)/16.402(1) Å, b=4.127(1)/4.445(4) Å, c=11.552(4)/12.311(1) Å and β=126.647(4)/126.515(7)° for Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3}, respectively). Magnetic susceptibility measurements in the interval 5–300 K confirm paramagnetic behavior and effectivemore » magnetic moments characteristic of Eu{sup 2+} ([Xe] 4f{sup 7}) ground states. Temperature-dependent electrical conductivity measurements also prove that Eu{sub 2}Cd{sub 2}As{sub 3} is a semiconducting compound with a narrow band gap of 0.059 eV below 100 K. According to TG/DSC analyses, Eu{sub 2}Cd{sub 2}As{sub 3} starts to decompose at about 950 K. - Graphical abstract: A polyhedral view of the crystal structure of new pnictides Eu{sub 2}T{sub 2}Pn{sub 3} (T=Zn or Cd; Pn=P or As). Display Omitted - Highlights: • Three new ternary pnictide Zintl compounds, Eu{sub 2}ZnP{sub 2}, Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3}, have been synthesized and characterized. • The europium cations are divalent and ferromagnetically coupled in both Eu{sub 2}Zn{sub 2}P{sub 3} and Eu{sub 2}Cd{sub 2}As{sub 3}. • Eu{sub 2}Cd{sub 2}As{sub 3} has a very small band gap of 0.06 eV and starts to decompose over 950 K.« less

New ruthenium carboxylate complexes having a 1-5-. eta. sup 5 -cyclooctadienyl ligand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Osakada, Kohtaro; Grohmann, A.; Yamamoto, Akio

1990-07-01

Reaction of 3-butenoic acid with Ru(cod)(cot) (cod) = 1-2-{eta}{sup 2}:5-6-{eta}{sup 2}-cyclooctadiene; cot = 1-6-{eta}{sup 6}-cyclooctatriene in the presence of PMe{sub 3} gives a new ruthenium(II) complex formulated as Ru(1-5-{eta}{sup 5}-C{sub 8}H{sub 11}){eta}{sup 1}(O),{eta}{sup 2}(C,C{prime}-OCOCH{sub 2}CH{double bond}CH{sub 2})(PMe{sub 3}) (1). X-ray crystallography revealed its structure as having a piano-stool coordination around the ruthenium center. Crystals of 1 are tetragonal, space group P4{sub 3}2{sub 1}2, with a = 12.559 (3) {angstrom}, c = 20.455 (4) {angstrom}, and Z = 8. {sup 1}H and {sup 13}C({sup 1}H) NMR spectra of 1 agree well for the structure with the allyl entity of the carboxylatemore » {pi}-bonded through the C{double bond}C double bond to ruthenium.« less

Crystallization and preliminary X-ray analysis of Ebola VP35 interferon inhibitory domain mutant proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leung, Daisy W.; Borek, Dominika; Farahbakhsh, Mina

2010-06-21

VP35 is one of seven structural proteins encoded by the Ebola viral genome and mediates viral replication, nucleocapsid formation and host immune suppression. The C-terminal interferon inhibitory domain (IID) of VP35 is critical for dsRNA binding and interferon inhibition. The wild-type VP35 IID structure revealed several conserved residues that are important for dsRNA binding and interferon antagonism. Here, the expression, purification and crystallization of recombinant Zaire Ebola VP35 IID mutants R312A, K319A/R322A and K339A in space groups P6{sub 1}22, P2{sub 1}2{sub 1}2{sub 1} and P2{sub 1}, respectively, are described. Diffraction data were collected using synchrotron sources at the Advanced Lightmore » Source and the Advanced Photon Source.« less

Crystallization and preliminary X-ray diffraction analysis of the small laccase from Streptomyces coelicolor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skálová, Tereza, E-mail: skalova@imc.cas.cz; Dohnálek, Jan; Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Praha 6

2007-12-01

The expression, purification and crystallization of the small laccase from S. coelicolor are reported. Diffraction data were collected to 3 Å resolution. The small bacterial laccase from the actinobacterium Streptomyces coelicolor which lacks the second of the three domains of the laccases structurally characterized to date was crystallized. This multi-copper phenol oxidase crystallizes in a primitive tetragonal lattice, with unit-cell parameters a = b = 179.8, c = 175.3 Å. The crystals belong to either space group P4{sub 1}2{sub 1}2 or P4{sub 3}2{sub 1}2. The self-rotation function shows the presence of a noncrystallographic threefold axis in the structure. Phases willmore » be determined from the anomalous signal of the natively present copper ions.« less

The structure, thermal expansion and phase transition properties of Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12} (x = 0, 1.0, 2.0) solid solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, X.Z.; Hao, L.J.; Wu, M.M.

Graphical abstract: A polymorph with Gd{sub 2}Mo{sub 3}O{sub 12}-type structure (space group: Pba2) for negative thermal expansion material Ho{sub 2}Mo{sub 3}O{sub 12} is observed above 700 °C, this polymorphism could be effectively supressed by W-substiution for Mo, the give the temperature dependence of Pba2 phase contents for Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12} (x = 0.0, 1.0, 2.0). - Highlights: • The solid solution Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12} was investigated by in situ X-ray diffraction. • It is found that the substitution slightly influence thermal expansion property. • A polymorph of Ho{sub 2}Mo{sub 3}O{sub 12} with Pba2 space group wasmore » observed above 700 °C. • The W-substitution for Mo effectively suppresses this transformation. - Abstract: Three solid solutions of Ho{sub 2}Mo{sub 3−x}W{sub x}O{sub 12}(x = 0, 1.0, 2.0) were prepared by solid state reaction method, the temperature dependent in-situ X-ray diffraction and thermal analysis were performed to investigate their structure and thermal expansion. All samples have orthorhombic structure(space group Pbcn# 60) with negative thermal expansion at the room temperature. the substitution of W for Mo enlarges the lattice constant and slightly influences the negative thermal expansion. An irreversible phase transformation to the Pba2 phase(Tb{sub 2}Mo{sub 3}O{sub 12} structure) was observed at high temperature for Mo-rich samples. This ploymorphism could be effectively suppressed by the W-substitution for Mo, this phenomenon could be explained by the lower electronegativity of W{sup 6+} than Mo{sup 6+}.« less

Influence of chemical bonds on the lifetime of the molecular-field-split 2p levels in H{sub 2}S

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bueno, Andre Machado; Brito, Arnaldo Naves de; Fink, Reinhold F.

Different lifetime broadenings in molecular-field-split 2p core levels in H{sub 2}S are predicted theoretically and are identified in an experimental investigation of the S 2p Auger electron spectrum. The measurements were performed for the transition to the vibrationally resolved X{sup 1}A{sub 1} ground state of H{sub 2}S{sup 2+}. The lifetimes of the 3e{sub 1/2} and 5e{sub 1/2} levels of the 2p ionized molecule are found to be 64 and 74 meV, respectively. This unambiguous determination of the lifetime difference of 10{+-}1 meV is only possible as the 4e{sub 1/2}{yields}X{sup 1}A{sub 1}(2b{sub 1}{sup -2}) decay channel that overlaps the 5e{sub 1/2}{yields}X{supmore » 1}A{sub 1}(2b{sub 1}{sup -2}) channel is practically suppressed in Auger decay in H{sub 2}S. The lifetime difference is confirmed by ab initio calculations. A theoretical analysis shows that it results from the mutual orientation of the core hole in the intermediate states and the valence electron density in the sulfur 3p orbitals. Both are strongly influenced by the chemical bond. Thus the observed effect is the direct result of a fundamental property of molecular electronic structure.« less

Crystallization and preliminary X-ray diffraction analysis of the periplasmic domain of the Escherichia coli aspartate receptor Tar and its complex with aspartate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mise, Takeshi; Matsunami, Hideyuki; Samatey, Fadel A.

The periplasmic domain of the E. coli aspartate receptor Tar was cloned, expressed, purified and crystallized with and without bound ligand. The crystals obtained diffracted to resolutions of 1.58 and 1.95 Å, respectively. The cell-surface receptor Tar mediates bacterial chemotaxis toward an attractant, aspartate (Asp), and away from a repellent, Ni{sup 2+}. To understand the molecular mechanisms underlying the induction of Tar activity by its ligands, the Escherichia coli Tar periplasmic domain with and without bound aspartate (Asp-Tar and apo-Tar, respectively) were each crystallized in two different forms. Using ammonium sulfate as a precipitant, crystals of apo-Tar1 and Asp-Tar1 weremore » grown and diffracted to resolutions of 2.10 and 2.40 Å, respectively. Alternatively, using sodium chloride as a precipitant, crystals of apo-Tar2 and Asp-Tar2 were grown and diffracted to resolutions of 1.95 and 1.58 Å, respectively. Crystals of apo-Tar1 and Asp-Tar1 adopted space group P4{sub 1}2{sub 1}2, while those of apo-Tar2 and Asp-Tar2 adopted space groups P2{sub 1}2{sub 1}2{sub 1} and C2, respectively.« less

A fresnoite-structure-related mixed valent titanium(III/IV) chlorosilicate, Ba{sub 3}Ti{sub 2}Si{sub 4}O{sub 14}Cl: A flux crystal growth route to Ti(III) containing oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abeysinghe, Dileka; Smith, Mark D.; Loye, Hans-Conrad zur, E-mail: zurloye@mailbox.sc.edu

Single crystals of mixed valent barium titanium(III/IV) chlorosilicate, Ba{sub 3}Ti{sub 2}Si{sub 4}O{sub 14}Cl{sub 0.91}O{sub 0.09}, were grown in a high temperature molten chloride flux involving an in situ reduction step. The fresnoite structure related Ba{sub 3}Ti{sub 2}Si{sub 4}O{sub 14}Cl{sub 0.91}O{sub 0.09} crystallizes in the tetragonal space group P4/mbm with lattice parameters of a=8.6717(2) Å, c=18.6492(5) Å. The title compound exhibits a 3D structure consisting of 2D layers of fused Ti{sub 2}O{sub 9} and Si{sub 4}O{sub 12} groups and 2D layers of fused Ti{sub 2}O{sub 9}Cl{sub 2} and Si{sub 2}O{sub 7} groups that are linked via barium atoms. The in situmore » reduction of Ti(IV) to Ti(III) is achieved via the addition of metallic Mg to the flux to function as the reducing agent. The temperature dependence of the magnetic susceptibility shows simple paramagnetism above 100 K. There is a discontinuity in the susceptibility data below 100 K, which might be due to a structural change that takes place resulting in charge ordering. - Graphical abstract: The fresnoite structure related novel reduced barium titanium chlorosilicate, Ba{sub 3}Ti{sub 2}Si{sub 4}O{sub 14}Cl{sub 0.91}O{sub 0.09}, were synthesized via flux method. An in situ reduction of Ti(IV) to Ti(III) achieved using Mg metal. The 3D structure consists 2D layers of fused Ti{sub 2}O{sub 9} and Si{sub 4}O{sub 12} and 2D layers of fused Ti{sub 2}O{sub 9}Cl{sub 2} and Si{sub 2}O{sub 7} connected via barium atoms. Compound shows simple paramagnetism above 100 K. - Highlights: • The fresnoite related Ba{sub 3}Ti{sub 2}Si{sub 4}O{sub 14}Cl{sub 0.91}O{sub 0.09} were grown via molten flux method. • The in situ reduction of Ti(IV) to Ti(III) is achieved using metallic Mg. • 2D layers of Ti{sub 2}O{sub 9} and Si{sub 4}O{sub 12} and Ti{sub 2}O{sub 9}Cl{sub 2} and Si{sub 2}O{sub 7} connect via Ba atoms. • The magnetic susceptibility shows simple paramagnetism above 100 K.« less

Microwave spectroscopy of the seeded binary and ternary clusters CO-(pH{sub 2}){sub 2}, CO-pH{sub 2}-He, CO-HD, and CO-(oD{sub 2}){sub N=1,2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raston, Paul L., E-mail: paul.raston@adelaide.edu.au; Jäger, Wolfgang

We report the Fourier transform microwave spectra of the a-type J = 1-0 transitions of the binary and ternary CO-(pH{sub 2}){sub 2}, CO-pH{sub 2}-He, CO-HD, and CO-(oD{sub 2}){sub N=1,2} clusters. In addition to the normal isotopologue of CO for all clusters, we observed the transitions of the minor isotopologues, {sup 13}C{sup 16}O, {sup 12}C{sup 18}O, and {sup 13}C{sup 18}O, for CO-(pH{sub 2}){sub 2} and CO-pH{sub 2}-He. All transitions lie within 335 MHz of the experimentally or theoretically predicted values. In comparison to previously reported infrared spectra [Moroni et al., J. Chem. Phys. 122, 094314 (2005)], we are able to tentativelymore » determine the vibrational shift for CO-pH{sub 2}-He, in addition to its b-type J = 1-0 transition frequency. The a-type frequency of CO-pH{sub 2}-He is similar to that of CO-He{sub 2} [Surin et al., Phys. Rev. Lett. 101, 233401 (2008)], suggesting that the pH{sub 2} molecule has a strong localizing effect on the He density. Perturbation theory analysis of CO-oD{sub 2} reveals that it is approximately T-shaped, with an anisotropy of the intermolecular potential amounting to ∼9 cm{sup −1}.« less

Crystal structure and ion conductivity of a new mixed-anion phosphate LiMg{sub 3}(PO{sub 4})P{sub 2}O{sub 7}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Sung-Chul; Lee, Mi-Sun; Kang, Jinyeong

2015-05-15

A new lithium-containing phosphate, LiMg{sub 3}(PO{sub 4})P{sub 2}O{sub 7}, was prepared by a solid-state reaction, and it was characterized by an ab initio structure determination method on the basis of synchrotron powder X-ray diffraction data. LiMg{sub 3}(PO{sub 4})P{sub 2}O{sub 7} was found to be orthorhombic (space group Pnma) with lattice parameters a=9.0387(1) Å, b=10.6072(1) Å, c=8.3065(1) Å, and V=796.39(1) Å{sup 3}. The structure features infinite [Mg{sub 3}O{sub 10}]{sub ∞} layers that are parallel to the bc plane and that are interconnected along the a axis by PO{sub 4} and P{sub 2}O{sub 7} groups. The [Mg{sub 3}O{sub 10}]{sub ∞} layer containsmore » Mg{sub 3}O{sub 14} trimers that are formed by three edge-shared MgO{sub 6} octahedra. The PO{sub 4} and P{sub 2}O{sub 7} groups are located alternatively between [Mg{sub 3}O{sub 10}]{sub ∞} layers. This gives rise to a three-dimensional framework that contains large tunnels along the directions [1 0 0] and [0 1 0]; the Li{sup +} ions are stabilized in these tunnels. AC impedance spectroscopy shows that LiMg{sub 3}(PO{sub 4})P{sub 2}O{sub 7} has an ionic conductivity of 3.40×10{sup −5} S cm{sup −1} at 769 K, with an activation energy of 1.17 eV. - Graphical abstract: Polyhedral view of LiMg3(PO4)P2O7. Li+ ions are represented by orange spheres, MgO6 groups by octahedra, and PO4 groups by tetrahedra. - Highlights: • New compound LiMg{sub 3}(PO{sub 4})P{sub 2}O{sub 7} is reported. • The crystal structure is investigated by synchrotron XRD analysis. • The structure features [Mg{sub 3}O{sub 10}]{sub ∞} layers with interconnecting PO{sub 4} and P{sub 2}O{sub 7} groups. • Correlation between the crystal structure and ionic conductivity is discussed.« less

Optical resolution of {pi}-thiophene complexes (C{sub 6}Me{sub 6}) Ru(2-RC{sub 4}H{sub 3}S){sup 2+} and related studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dailey, K.K.; Rauchfuss, T.B.

Diasteriomeric iminium thiolato complexes were prepared by the addition of S-(-)-{alpha}-methylbenzylamine to the {pi}-thiophene complexes [(C{sub 6}Me{sub 6})Ru(2-RC{sub 4}H{sub 3}S)]{sup 2+}, where R = Me(1{sup 2+}), CH{sub 2}OH (3{sup 2+}), and 2-C{sub 4}H{sub 3}S(6{sup 2+}). After chromatographic separation, the diastereomers were treated with HOTf to generate optically pure {pi}-thiophene complexes. The absolute configuration of [(C{sub 6}Me{sub 6})RuSCMeC{sub 2}H{sub 2}(CHNHCHMePh)]OTf, (-)-2(OTf), was determined by a single-crystal X-ray diffraction; the monohydrate crystallized in the acentric space group P2{sub 1}2{sub 1}2{sub 1}. Base hydrolysis of (-)-1{sup 2+} gave the formyl thiolato complex (-)-9{sub kin}, which isomerized to (+)-9{sub therm} with inversion of configurationmore » at Ru, as indicated by circular dichroism measurements. The methyl ester of the amino acid (L)-phenylalanine was shown to add to (C{sub 6}Me{sub 6})Ru(C{sub 4}H{sub 4}S){sup 2+} to give a 2:1 mixture of diastereomeric iminium thiolato complexes. 19 refs., 3 figs., 2 tabs.« less

Crystallization and preliminary X-ray analysis of a native human tRNA synthetase whose allelic variants are associated with Charcot–Marie–Tooth disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Wei; Schimmel, Paul; Yang, Xiang-Lei, E-mail: xlyang@scripps.edu

2006-12-01

Crystallization and preliminary X-ray analysis of a native human tRNA synthetase whose allelic variants are associated with Charcot–Marie–Tooth Disease. Glycyl-tRNA synthetase (GlyRS) is one of a group of enzymes that catalyze the synthesis of aminoacyl-tRNAs for translation. Mutations of human and mouse GlyRSs are causally associated with Charcot–Marie–Tooth disease, the most common genetic disorder of the peripheral nervous system. As the first step towards a structure–function analysis of this disease, native human GlyRS was expressed, purified and crystallized. The crystal belonged to space group P4{sub 3}2{sub 1}2 or its enantiomorphic space group P4{sub 1}2{sub 1}2, with unit-cell parameters a =more » b = 91.74, c = 247.18 Å, and diffracted X-rays to 3.0 Å resolution. The asymmetric unit contained one GlyRS molecule and had a solvent content of 69%.« less

Structural and dielectric properties of La and Ni-doped M-type BaFe{sub 12}O{sub 19} ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Poorva; Varshney, Dinesh, E-mail: vdinesh33@rediffmail.com, E-mail: dubea89@yahoo.com; Kumar, Ashwini

2016-05-23

BaFe{sub 12}O{sub 19} and Ba{sub 0.98}La{sub 0.02}Fe{sub 12-x}Ni{sub x}O{sub 19} (x = 0.02, 0.05) samples synthesized using solid-state reaction route crystallizes in hexagonal structure with space group P6{sub 3}/mmc as revealed from X-ray diffraction. A Raman spectrum shows seven strong and sharp modes at 291.9 (A{sub 1g}), 410.4 (E{sub 2g}), 496.09 (A{sub 1g}), 611.3 (E{sub 2g}), 681(A{sub 1g}), 1048.0 (A{sub 1g}+A{sub 1g}) and 1313.3 cm{sup −1} (A{sub 1g}+E{sub 2g}), identifying the presence of barium hexaferrite phase. The higher values of the dielectric constant at lower frequency and lower values at higher frequency indicate the dispersion due to interfacial polarization. Dielectricmore » constant decreases as the doping concentration of Ni increases due to increase in band gap. A resonance peak has been observed in all three sample and is attributed to the fact that hopping frequency of charge carrier matches well with the frequency of the applied field. Henceforth, Ba{sub 0.98}La{sub 0.02}Fe{sub 12-x}Ni{sub x}O{sub 19} (x = 0.02, 0.05) is suitable novel materials for microwave application with low dielectric constant and dielectric loss values.« less

Crystallization and preliminary X-ray diffraction studies of trypsin-like proteases from the gastric fluid of the marine crab Cancer pagurus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hehemann, Jan-Hendrik; Redecke, Lars; Perbandt, Markus

2007-03-01

Two trypsins from the gastric fluid of the marine crab C. pagurus were purified and crystallized and X-ray data were collected to 0.97 and 3.2 Å resolution. The digestive fluid of the marine crab Cancer pagurus (Decapoda, Brachyura) contains highly stable proteases which display enhanced activity in aqueous mixtures of organic solvents. Three trypsins were isolated from the gastric fluid and two of them, C.p.TryII and C.p.TryIII, were purified to homogeneity by anion-exchange chromatography and crystallized by hanging-drop vapour diffusion. Diffraction data were collected at a synchrotron to 0.97 and 3.2 Å resolution, respectively. The crystal of C.p.TryII belongs tomore » the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 52.06, b = 62.00, c = 71.66 Å. Based on the Matthews coefficient, one protein molecule per asymmetric unit is suggested. In contrast, crystals of C.p.TryIII, which belong to the cubic space group P2{sub 1}3 with unit-cell parameters a = b = c = 215.4 Å, are assumed to contain 12 molecules per asymmetric unit.« less

Radiation dose in coronary angiography and intervention: initial results from the establishment of a multi-centre diagnostic reference level in Queensland public hospitals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crowhurst, James A, E-mail: jimcrowhurst@hotmail.com; School of Medicine, University of Queensland, St. Lucia, Brisbane, Queensland; Whitby, Mark

Radiation dose to patients undergoing invasive coronary angiography (ICA) is relatively high. Guidelines suggest that a local benchmark or diagnostic reference level (DRL) be established for these procedures. This study sought to create a DRL for ICA procedures in Queensland public hospitals. Data were collected for all Cardiac Catheter Laboratories in Queensland public hospitals. Data were collected for diagnostic coronary angiography (CA) and single-vessel percutaneous intervention (PCI) procedures. Dose area product (P{sub KA}), skin surface entrance dose (K{sub AR}), fluoroscopy time (FT), and patient height and weight were collected for 3 months. The DRL was set from the 75th percentilemore » of the P{sub KA.} 2590 patients were included in the CA group where the median FT was 3.5 min (inter-quartile range = 2.3–6.1). Median K{sub AR} = 581 mGy (374–876). Median P{sub KA} = 3908 uGym{sup 2} (2489–5865) DRL = 5865 uGym{sup 2}. 947 patients were included in the PCI group where median FT was 11.2 min (7.7–17.4). Median K{sub AR} = 1501 mGy (928–2224). Median P{sub KA} = 8736 uGym{sup 2} (5449–12,900) DRL = 12,900 uGym{sup 2}. This study established a benchmark for radiation dose for diagnostic and interventional coronary angiography in Queensland public facilities.« less

LCP crystallization and X-ray diffraction analysis of VcmN, a MATE transporter from Vibrio cholerae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kusakizako, Tsukasa; Tanaka, Yoshiki; Hipolito, Christopher J.

A V. cholerae MATE transporter was crystallized using the lipidic cubic phase (LCP) method. X-ray diffraction data sets were collected from single crystals obtained in a sandwich plate and a sitting-drop plate to resolutions of 2.5 and 2.2 Å, respectively. Multidrug and toxic compound extrusion (MATE) transporters, one of the multidrug exporter families, efflux xenobiotics towards the extracellular side of the membrane. Since MATE transporters expressed in bacterial pathogens contribute to multidrug resistance, they are important therapeutic targets. Here, a MATE-transporter homologue from Vibrio cholerae, VcmN, was overexpressed in Escherichia coli, purified and crystallized in lipidic cubic phase (LCP). X-raymore » diffraction data were collected to 2.5 Å resolution from a single crystal obtained in a sandwich plate. The crystal belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 52.3, b = 93.7, c = 100.2 Å. As a result of further LCP crystallization trials, crystals of larger size were obtained using sitting-drop plates. X-ray diffraction data were collected to 2.2 Å resolution from a single crystal obtained in a sitting-drop plate. The crystal belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 61.9, b = 91.8, c = 100.9 Å. The present work provides valuable insights into the atomic resolution structure determination of membrane transporters.« less

Contribution of central and peripheral adaptations to changes in VO₂max following four weeks of sprint interval training.

PubMed

Raleigh, James P; Giles, Matthew D; Islam, Hashim; Nelms, Matthew William; Bentley, Robert F; Jones, Joshua H; Neder, J Alberto; Boonstra, Kristen; Quadrilatero, Joe; Simpson, Craig A; Tschakovsky, Michael E; Gurd, Brendon J

2018-05-07

The current study examined the contribution of central and peripheral adaptations to changes in maximal oxygen uptake (VO₂max) following sprint interval training (SIT). Twenty-three males completed four weekly SIT sessions (8 x 20 second cycling bouts at ~170% of work rate at VO₂max, 10 second recovery) for four weeks. Following completion of training, the relationship between changes in VO₂max and changes in central (cardiac output) and peripheral (a-vO₂diff, muscle capillary density, oxidative capacity, fibre-type distribution) adaptations was determined in all participants using correlation analysis. Participants were then divided in to tertiles based on the magnitude of their individual VO₂max responses and differences in central/peripheral adaptations were examined in the top (HI; ~10 mL/kg/min increase in VO₂max, p<0.05) and bottom (LO; no change in VO₂max, p>0.05) tertiles (n=8 each). Training had no impact on Qmax and no differences were observed between the LO and HI groups (p>0.05). A-vO₂diff increased in the HI group only (p<0.05) and correlated significantly (r=0.71, p<0.01) with changes in VO₂max across all participants. Muscle capillary density (p<0.02) and ß-hydroxyacyl-CoA dehydrogenase maximal activity (p<0.05) increased in both groups, with no between-group differences (p>0.05). Citrate synthase maximal activity (p<0.01) and type IIA fibre composition (p<0.05) increased in the LO group only. Collectively, while the heterogeneity in the observed VO₂max response following four weeks of SIT appears to be attributable to individual differences in systemic vascular and/or muscular adaptations, the markers examined in the current study were unable to explain the divergent VO₂max responses in the LO and HI groups.

Structural characterizations and magnetic properties of three new reduced molybdenum phosphates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Xiao; Xu Jiqing; Yu Jiehui

2007-06-15

Three new molybdophosphates, [Co(dien){sub 2}].(H{sub 3}dien){sub 6}.{l_brace}[CoMo{sub 12}O{sub 24}(OH){sub 6}(HPO{sub 4}){sub 2}(PO{sub 4}){sub 6}][Co(Hdien)]{sub 2}[CoMo{sub 12}O{sub 24} (OH){sub 6}(PO{sub 4}){sub 8}]{r_brace}.(dien).4H{sub 3}O.5H{sub 2}O (1) (H{sub 3}dien){sub 4}[MMo{sub 12}O{sub 24}(OH){sub 6}(HPO{sub 4}){sub 4}(PO{sub 4}){sub 4}].10H{sub 2}O [M=Co for (2), Ni for (3); dien=diethylenetriamine], have been synthesized by employing hydrothermal method and characterized by single crystal X-ray diffraction. Compound 1 is built up of Co[P{sub 4}Mo{sub 6}]{sub 2} units as the structural motif covalently linked by [Co(Hdien)] complex subunits to yield an unusual 1-D chain. Compounds 2 and 3 are isomorphic and both display covalent discrete M[P{sub 4}Mo{sub 6}]{sub 2} cluster structuresmore » which are linked by the hydrogen bonds to form 3-D supramolecular networks. Both 1 and 2 display antiferromagnetic interaction and these three compounds all exhibit intensive photoluminescence. - Graphical abstract: Three new reduced molybdophoshpates based on P{sub 4}MO{sub 6} building blocks have been hydrothermally synthesized. 1 is the first covalent 1-D chain consisting of two kinds of forms of M[P{sub 4}MO{sub 6}]{sub 2} units, standing forms A and lying forms B, while 2 and 3 possess 3-D supramolecular network structures. These three compounds all display photoluminescence.« less

Synthesis and up-conversion luminescence of Er{sup 3+} and Y b{sup 3+} codoped nanocrystalline tetra- (KLaP{sub 4}O{sub 12}) and pentaphosphates (LaP{sub 5}O{sub 14})

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marciniak, L., E-mail: l.marciniak@int.pan.wroc.pl; Stefanski, M.; Tomala, R.

2015-09-07

The up-converting nanocrystals of KLa{sub 0.95}Er{sub 0.05}Y b{sub x}P{sub 4}O{sub 12} and La{sub 0.95−x}Er{sub 0.05}Y b{sub x}P{sub 5}O{sub 14} were prepared using co-precipitation method. The spectroscopic properties of these materials were investigated in a function of Y b{sup 3+} concentration. The up-conversion emission, power dependence of emission intensities, and the luminescence decay times were investigated. It was found that the green to red and {sup 2}H{sub 11/2} → {sup 4}I{sub 15/2} to {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} emission intensity ratio were strongly affected by the Y b{sup 3+} concentration. Moreover, the order of up-conversion emission and threshold powermore » rises up with Y b{sup 3+} concentration for {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} transition. The luminescence decay time of the {sup 4}S{sub 3/2} → {sup 4}I{sub 15/2} emission increases with Y b{sup 3+} concentration while the {sup 4}F{sub 9/2} → {sup 4}I{sub 15/2} emission is independent of dopant concentration. The influence of the Y b{sup 3+} concentration on the up-conversion emission intensities was discussed in terms of concentration dependent hetero looped photon avalanche process. A comparison of the up-conversion properties of KLa{sub 0.95}Er{sub 0.05}Y b{sub x}P{sub 4}O{sub 12} and La{sub 0.95−x}Er{sub 0.05}Y b{sub x}P{sub 5}O{sub 14} nanocrystals was presented.« less

Synthesis and structure of novel lithium-ion conductor Li{sub 7}Ge{sub 3}PS{sub 12}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inoue, Yuki; Suzuki, Kota; Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama 226-8502

The novel lithium-ion conductor Li{sub 7}Ge{sub 3}PS{sub 12} was synthesized by slow cooling from the ternary Li{sub 2}S–GeS{sub 2}–P{sub 2}S{sub 5} system, and was shown to exhibit a cubic argyrodite-type structure. The phase composition was determined by varying the ratio of starting materials; the observed monophasic properties were close to those for the Li{sub 7}Ge{sub 3}PS{sub 12} composition. The lattice parameter (a =9.80192(3) Å) of Li{sub 7}Ge{sub 3}PS{sub 12} was slightly smaller than that of Li{sub 7}PS{sub 6} (a =9.993 Å), indicating that substitution of a Li cation by the smaller Ge cation contracted the cubic lattice. In addition, themore » novel structure consisted of a framework composed of four isolated (Ge/P)S{sub 4} tetrahedra. Li{sup +} ions occupied tetrahedral sites within the framework, forming a three-dimensional conduction pathway. Finally, Li{sub 7}Ge{sub 3}PS{sub 12} exhibited a high ionic conductivity of 1.1×10{sup −4} S cm{sup −1} at 25 °C and an activation energy of 25 kJ mol{sup −1}. - Graphical abstract: A novel Li{sub 7}Ge{sub 3}PS{sub 12} solid lithium ion conductor, with cubic argyrodite strucuture, shows high ion conductivity of 1.1×10{sup –4} S cm{sup –1} with an activation energy of 25 kJ mol{sup –1}. The argyrodite structure consists of (Ge/P)S{sub 4} tetrahedra units along with partial occupation of lithium and germanium at 48 h site. - Highlights: • A novel lithium-ion conductor Li{sub 7}Ge{sub 3}PS{sub 12} was detected. • This was achieved through slow cooling of the ternary Li{sub 2}S–GeS{sub 2}–P{sub 2}S{sub 5} system. • This novel conductor revealed a cubic argyrodite-type structure. • Li{sub 7}Ge{sub 3}PS{sub 12} exhibited a high ionic conductivity of 1.1×10{sup −4} S cm{sup −1} at 25 °C. • These properties will aid in the design of superior lithium-ion conductors.« less

Oxidative addition of allylic halides to ruthenium(II) compounds. Preparation, reactions, and X-ray crystallographic structure of ruthenium(IV)-allyl complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagashima, Hideo; Mukai, Katsunori; Shiota, Yusuke

1990-03-01

The oxidative addition of allylic halides to (C{sub 5}R{sub 5})RuL{sub 2}X (R = H, Me; L = CO, PPh{sub 3}) gave new Ru(IV)-{eta}{sup 3}-allyl complexes, (C{sub 5}R{sub 5})RuX{sub 2}({eta}{sup 3}-allyl). An X-ray structure determination was carried out on (C{sub 5}Me{sub 5})RuBr{sub 2}({eta}{sup 3}-C{sub 3}H{sub 5}), indicating a pseudo-piano-stool structure having two Br atoms and two terminal carbons of the endo-{eta}{sup 3}-allyl ligand located at the basal positions. There is a crystal mirror plane bisecting the pentamethylcyclopentadienyl and the {pi}-allyl ligands. Crystal data: orthorhombic, space group P2{sub 1}2{sub 1}2{sub 1}, a = 22.738 (1) {angstrom}, b = 13.367 (7) {angstrom}, cmore » = 9.383 (1) {angstrom}, Z = 4., data refined to R = 0.0695. Its {sup 1}H and {sup 13}C NMR spectra showed symmetric allyl signals, supporting that the above-described piano-stool structure is maintained even in solution.« less

Blow-up profile to the solutions of two-coupled Schroedinger equations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Jianqing; Guo Boling

2009-02-15

The model of the following two-coupled Schroedinger equations, i{sub t}+(1/2){delta}u=(g{sub 11}|u|{sup 2p}+g|u|{sup p-1}|v|{sup p+1})uu, (t,x)(set-membership sign)R{sub +}xR{sup N}, and iv{sub t}+(1/2){delta}v=(g|u|{sup p+1}|v|{sup p-1}+g{sub 22}|v|{sup 2p})v, (t,x)(set-membership sign)R{sub +}xR{sup N}, is proposed in the study of the Bose-Einstein condensates [Mitchell, et al., ''Self-traping of partially spatially incoherent light,'' Phys. Rev. Lett. 77, 490 (1996)]. We prove that for suitable initial data and p the solution blows up exactly like {delta} function. As a by-product, we prove that similar phenomenon occurs for the critical two-coupled Schroedinger equations with harmonic potential [Perez-Garcia, V. M. and Beitia, T. B., ''Sybiotic solitons in heteronuclear multicomponentmore » Bose-Einstein condensates,'' Phys. Rev. A 72, 033620 (2005)], iu{sub t}+(1/2){delta}u=({omega}/2)|x|{sup 2}u+(g{sub 11}|u|{sup 2p}+g|u|{sup p-1}|v|{sup p+1})u, x(set-membership sign)R{sup N}, and iv{sub t}+(1/2){delta}v=({omega}/2)|x|{sup 2}v+(g|u|{sup p+1}|v|{sup p-1}+g{sub 22}|v|{sup 2p})v, x(set-membership sign)R{sup N}.« less

Crystal structure of the true Nasicon: Na/sub 3/Zr/sub 2/Si/sub 2/PO/sub 12/

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boilot, J.P.; Collin, G.; Colomban, P.

For the first time, the results of single crystal determination of the true Nasicon are given. The structure refinement yielded the following composition: Na/sub 3.09(8)/Zr/sub 2.01(1)/P/sub 0.91/Si/sub 2.09/O/sub 12/. Evidence of the total occupancy of the Zr octahedron is found, displaying that only the Si/P non-stoichiometry mechanism is present in the Nasicon crystal. For the two temperatures which have been investigated (R.T. and 623K), the structures are very close to that of the Nasicon analog: Na/sub 3/Sc/sub 2/P/sub 3/O/sub 12/. However the Si/P substitution prevents the sodium long range ordering even in the monoclinic low temperature phase and therefore themore » cross over to the rhombohedral symmetry only involves very small atomic displacements. For both structures, a new sodium position (mid-Na) is displayed in the conduction channel, intermediate between the usual Na(1) and Na(2) sites.« less

In pursuit of the rhabdophane crystal structure: from the hydrated monoclinic LnPO{sub 4}.0.667H{sub 2}O to the hexagonal LnPO{sub 4} (Ln = Nd, Sm, Gd, Eu and Dy)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mesbah, Adel, E-mail: adel.mesbah@cea.fr; Clavier, Nicolas; Elkaim, Erik

The dehydration process of the hydrated rhabdophane LnPO{sub 4}.0.667H{sub 2}O (Ln = La to Dy) was thoroughly studied over the combination of in situ high resolution synchrotron powder diffraction and TGA experiments. In the case of SmPO{sub 4}.0.667H{sub 2}O (monoclinic, C2), a first dehydration step was identified around 80 °C leading to the formation of SmPO{sub 4}.0.5H{sub 2}O (Monoclinic, C2) with Z =12 and a =17.6264(1) Å, b =6.9704(1) Å, c =12.1141(1) Å, β=133.74(1) °, V =1075.33(1) Å{sup 3}. In agreement with the TGA and dilatometry experiments, all the water molecules were evacuated above 220 °C yielding to the anhydrousmore » form, which crystallizes in the hexagonal P3{sub 1}21 space group with a =7.0389(1) Å, c =6.3702(1) Å and V =273.34(1) Å{sup 3}. This study was extended to selected LnPO{sub 4}.0.667H{sub 2}O samples (Ln= Nd, Gd, Eu, Dy) and the obtained results confirmed the existence of two dehydration steps before the stabilization of the anhydrous form, with the transitory formation of LnPO{sub 4}.0.5H{sub 2}O. - Graphical abstract: The dehydration process of the rhabdophane SmPO{sub 4}.0.667H{sub 2}O was studied over combination of in situ high resolution synchrotron powder diffraction and TGA techniques, a first dehydration was identified around 80 °C leading to the formation of SmPO{sub 4}.0.5H{sub 2}O (Monoclinic, C2). Then above 220 °C, the anhydrous form of the rhabdophane SmPO{sub 4} was stabilized and crystallizes in the hexagonal P3{sub 1}21 space group. - Highlights: • In situ synchrotron powder diffraction was carried out during the dehydration of the rhabdopahe LnPO{sub 4}.0.667H{sub 2}O. • The heat of the rhabdophane LnPO{sub 4}.0.667H{sub 2}O leads to LnPO{sub 4}.0.5H{sub 2}O then to anhydrous rhabdophane LnPO{sub 4}. • LnPO{sub 4}.0.5H{sub 2}O (monoclinic, C2) and LnPO{sub 4} (Hexagonal, P3{sub 1}21) were solved over the use of direct methods.« less

Synthesis, structure, and polymorphism of A{sub 3}LnSi{sub 2}O{sub 7} (A=Na, K; Ln=Sm, Ho, Yb)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Latshaw, Allison M.; Yeon, Jeongho; Smith, Mark D.

2016-03-15

Four new members of the A{sub 3}LnSi{sub 2}O{sub 7} family, K{sub 3}SmSi{sub 2}O{sub 7}, Na{sub 3}HoSi{sub 2}O{sub 7}, and two polymorphs of Na{sub 3}YbSi{sub 2}O{sub 7}, are reported. K{sub 3}SmSi{sub 2}O{sub 7} crystallizes in the hexagonal space group P6{sub 3}/mcm, Na{sub 3}HoSi{sub 2}O{sub 7} and Na{sub 3}YbSi{sub 2}O{sub 7} crystallize in the hexagonal space group P6{sub 3}/m, and Na{sub 3}YbSi{sub 2}O{sub 7} crystallizes in the trigonal space group P31c. The Na{sub 3}YbSi{sub 2}O{sub 7} composition that crystallizes in P31c is a new structure type. The magnetic properties for the Ho and Yb analogs are reported. - Graphical abstract: The differentmore » structure types and polymorphs of the A{sub 3}LnSi{sub 2}O{sub 7} family reported. - Highlights: • Four new members of the A{sub 3}LnSi{sub 2}O{sub 7} family are presented. • Na{sub 3}YbSi{sub 2}O{sub 7} is reported as two polymorphs, one is a new structure type. • Crystals synthesized out of molten fluoride fluxes.« less

Syntheses, structures, and vibrational spectroscopy of the two-dimensional iodates Ln(IO{sub 3}){sub 3} and Ln(IO{sub 3}){sub 3}(H{sub 2}O) (Ln =Yb, Lu)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Assefa, Zerihun; Ling Jie; Haire, Richard G.

2006-12-15

The reaction of Lu{sup 3+} or Yb{sup 3+} and H{sub 5}IO{sub 6} in aqueous media at 180 {sup o}C leads to the formation of Yb(IO{sub 3}){sub 3}(H{sub 2}O) or Lu(IO{sub 3}){sub 3}(H{sub 2}O), respectively, while the reaction of Yb metal with H{sub 5}IO{sub 6} under similar reaction conditions gives rise to the anhydrous iodate, Yb(IO{sub 3}){sub 3}. Under supercritical conditions Lu{sup 3+} reacts with HIO{sub 3} and KIO{sub 4} to yield the isostructural Lu(IO{sub 3}){sub 3}. The structures have been determined by single-crystal X-ray diffraction. Crystallographic data are (MoK{alpha}, {lambda}=0.71073 A): Yb(IO{sub 3}){sub 3}, monoclinic, space group P2{sub 1}/n, a=8.6664(9)more » A, b=5.9904(6) A, c=14.8826(15) A, {beta}=96.931(2){sup o}, V=766.99(13), Z=4, R(F)=4.23% for 114 parameters with 1880 reflections with I>2{sigma}(I); Lu(IO{sub 3}){sub 3}, monoclinic, space group P2{sub 1}/n, a=8.6410(9), b=5.9961(6), c=14.8782(16) A, {beta}=97.028(2){sup o}, V=765.08(14), Z=4, R(F)=2.65% for 119 parameters with 1756 reflections with I>2{sigma}(I); Yb(IO{sub 3}){sub 3}(H{sub 2}O), monoclinic, space group C2/c, a=27.2476(15), b=5.6296(3), c=12.0157(7) A, {beta}=98.636(1){sup o}, V=1822.2(2), Z=8, R(F)=1.51% for 128 parameters with 2250 reflections with I>2{sigma}(I); Lu(IO{sub 3}){sub 3}(H{sub 2}O), monoclinic, space group C2/c, a=27.258(4), b=5.6251(7), c=12.0006(16) A, {beta}=98.704(2){sup o}, V=1818.8(4), Z=8, R(F)=1.98% for 128 parameters with 2242 reflections with I>2{sigma}(I). The f elements in all of the compounds are found in seven-coordinate environments and bridged with monodentate, bidentate, or tridentate iodate anions. Both Lu(IO{sub 3}){sub 3}(H and Yb(IO{sub 3}){sub 3}(H{sub 2}O) display distinctively different vibrational profiles from their respective anhydrous analogs. Hence, the Raman profile can be used as a complementary diagnostic tool to discern the different structural motifs of the compounds. - Graphical abstract: Four new metal iodates, Yb(IO{sub 3}){sub 3}, Lu(IO{sub 3}){sub 3}, Yb(IO{sub 3}){sub 3}(H{sub 2}O), and Lu(IO{sub 3}){sub 3}(H{sub 2}O), have all been isolated as single crystals through the use of hydrothermal reactions. Structural determinations using single-crystal X-ray diffraction have shown that the materials are all alike in that they contain two-dimensional structures. Vibrational profiles for all of the materials have been collected, using Raman spectroscopy, and analyzed.« less

Low temperature synthesis and characterization of Na–M–(O)–F phases with M=Ti, V

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nava-Avendaño, Jessica; Ayllón, José A.; Frontera, Carlos

2015-03-15

Na{sub 5}Ti{sub 3}O{sub 3}F{sub 11} was prepared by the microwave assisted method, and presents a chiolite related structure with cell parameters a=10.5016(5), b=10.4025(5), and c=10.2911(5) Å and Cmca (no. 64) space group. From solvothermal synthesis at 100 °C the cryolite Na{sub 3−δ}VO{sub 1−δ}F{sub 5+δ} was prepared, which crystallizes in the monoclinic system with a=5.5403(2), b=5.6804(2), c=7.9523(2) Å, β=90.032(7)° cell parameters and P2{sub 1}/n (no. 14) space group. Under similar synthesis conditions but with higher HF concentration the chiolite-type phase Na{sub 5−δ}V{sub 3}F{sub 14} was achieved, which exhibits a=10.5482(2), b=10.4887(1) and c=10.3243(1) Å cell parameters and Cmc2{sub 1} (no. 36) spacemore » group. A single crystal also having the chiolite structure was synthesized at 200 °C which exhibits tetragonal symmetry (a=7.380(3) and c=10.381(11) Å and space group P4{sub 2}2{sub 1}2 (no. 94)). Bond valence sum indicates that it contains V{sup 4+} and therefore can be formulated as Na{sub 5}V{sub 3}O{sub 3}F{sub 11}. - Graphical abstract: Na{sub 5}M{sub 3}(O,F){sub 14} with M=Ti and V having chiolite structure and Na{sub 3−δ}VO{sub 1−δ}F{sub 5+δ} cryolite were prepared by means of microwave-assisted and solvothermal synthesis. - Highlights: • Na{sub 5}Ti{sub 3}O{sub 3}F{sub 11} chiolite was prepared by a microwave assisted method and characterized. • Na{sub 3−δ}VO{sub 1−δ}F{sub 5+δ} and Na{sub 5−δ}V{sub 3}F{sub 14} were prepared by solvothermal synthesis. • The compounds were structurally characterized by diffraction techniques. • O/F distribution was estimated by applying Pauling’s second rule.« less

Purification, crystallization and preliminary X-ray diffraction analysis of the carbohydrate-binding region of the Streptococcus gordonii adhesin GspB

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pyburn, Tasia M.; Yankovskaya, Victoria; Bensing, Barbara A.

2012-07-11

The carbohydrate-binding region of the bacterial adhesin GspB from Streptococcus gordonii strain M99 (GspB{sub BR}) was expressed in Escherichia coli and purified using affinity and size-exclusion chromatography. Separate sparse-matrix screening of GspB{sub BR} buffered in either 20 mM Tris pH 7.4 or 20 mM HEPES pH 7.5 resulted in different crystallographic behavior such that different precipitants, salts and additives supported crystallization of GspB{sub BR} in each buffer. While both sets of conditions supported crystal growth in space group P2{sub 1}2{sub 1}2{sub 1}, the crystals had distinct unit-cell parameters of a = 33.3, b = 86.7, c = 117.9 {angstrom} formore » crystal form 1 and a = 34.6, b = 98.3, c = 99.0 {angstrom} for crystal form 2. Additive screening improved the crystals grown in both conditions such that diffraction extended to beyond 2 {angstrom} resolution. A complete data set has been collected to 1.3 {angstrom} resolution with an overall R{sub merge} value of 0.04 and an R{sub merge} value of 0.33 in the highest resolution shell.« less

Synthesis and characterization of the pseudo-hexagonal hollandites ALi{sub 2}Ru{sub 6}O{sub 12} (A=Na, K)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foo, M.L.; He, T.; Huang, Q.

The crystal structures, synthesis and physical properties of ruthenium hollandites ALi{sub 2}Ru{sub 6}O{sub 12} (A=Na, K) with a new pseudo-hexagonal structure type are described. Analogous to tetragonal hollandites, the framework is made of MO{sub 6} octahedra in double chains that share corner oxygens with each other to create interstitial tunnels. The tunnels are either hexagonal or triangular in cross-section. Magnetic susceptibilities, low temperature specific heat, and electrical resistivities are reported. The data indicate that these materials are normal, low density of states metals. This new structure type can be extended from A=Group I to A=Group II ions with the synthesismore » of CaLi{sub 2}Ru{sub 6}O{sub 12} and SrLi{sub 2}Ru{sub 6}O{sub 12}.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, Prasanta; Lee, Yuan-Pern; Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan

Irradiation at 193 nm of a p-H{sub 2} matrix containing acryloyl chloride CH{sub 2}CHC(O)Cl at 3.2 K yielded infrared absorption lines at 3143.6 (ν{sub 1}), 3057.0 (ν{sub 2}), 3048.0 (ν{sub 3}), 2103.1 (ν{sub 4}), 1461.0 (ν{sub 5}), 1349.8 (ν{sub 6}), 1223.7 (ν{sub 11}+ν{sub 12} or 2ν{sub 12}), 1092.8 (ν{sub 8}), 918.1 (ν{sub 9}), 691.0 (ν{sub 10}), 624.3 (ν{sub 11}), and 597.1 (ν{sub 12}) cm{sup −1} that are assigned to the 3-propenonyl (⋅CH{sub 2}CHCO) radical. The assignments are based on the photolytic behavior and a comparison of observed vibrational wavenumbers and infrared intensities with those predicted with the B3PW91/aug-cc-pVDZ method. Themore » observation is consistent with a major radical formation channel CH{sub 2}CHCO + Cl followed by escape of the Cl atom from the original p-H{sub 2} cage. The observation of 3-propenonyl (⋅CH{sub 2}CHCO) radical but not 3-propenalyl (s-cis- or s-trans-CH{sub 2}CHĊO) radical indicates that the former is the most stable isomer and that the barrier heights for conversion from s-cis- or s-trans-CH{sub 2}CHĊO to ⋅CH{sub 2}CHCO are small.« less

Y{sub 2}MoSe{sub 3}O{sub 12} and Y{sub 2}MoTe{sub 3}O{sub 12}: Solid-state synthesis, structure determination, and characterization of two new quaternary mixed metal oxides containing asymmetric coordination environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bang, Seong-eun; Pan, Zhi; Kim, Yeong Hun

Two new quaternary yttrium molybdenum selenium/tellurium oxides, Y{sub 2}MoSe{sub 3}O{sub 12} and Y{sub 2}MoTe{sub 3}O{sub 12} have been prepared by standard solid-state reactions using Y{sub 2}O{sub 3}, MoO{sub 3}, and SeO{sub 2} (or TeO{sub 2}) as reagents. Single-crystal X-ray diffraction was used to determine the crystal structures of the reported materials. Although both of the materials contain second-order Jahn–Teller (SOJT) distortive cations and are stoichiometrically similar, they reveal different structural features: while Y{sub 2}MoSe{sub 3}O{sub 12} shows a three-dimensional framework consisting of YO{sub 8}, MoO{sub 6}, and SeO{sub 3} groups, Y{sub 2}MoTe{sub 3}O{sub 12} exhibits a layered structure composed ofmore » YO{sub 8}, MoO{sub 4}, TeO{sub 3}, and TeO{sub 4} polyhedra. With the Mo{sup 6+} cations in Y{sub 2}MoSe{sub 3}O{sub 12}, a C{sub 3}-type intraoctahedral distortion toward a face is observed, in which the direction of the out-of-center distortion for Mo{sup 6+} is away from the oxide ligand linked to a Se{sup 4+} cation. The Se{sup 4+} and Te{sup 4+} cations in both materials are in asymmetric coordination environment attributed to the lone pairs. Elemental analyses, infrared spectroscopy, thermal analyses, intraoctahedral distortions, and dipole moment calculations for the compounds are also presented. - Graphical abstract: Y{sub 2}MoSe{sub 3}O{sub 12} reveals a three-dimensional framework consisting of YO{sub 8}, MoO{sub 6}, and SeO{sub 3} polyhedra, whereas Y{sub 2}MoTe{sub 3}O{sub 12} exhibits a layered structure composed of YO{sub 8}, MoO{sub 4}, TeO{sub 3}, and TeO{sub 4} groups. - Highlights: • Two new selenite and tellurite (Y{sub 2}MoQ{sub 3}O{sub 12}; Q=Se and Te) are synthesized. • Y{sub 2}MoQ{sub 3}O{sub 12} contain second-order Jahn–Teller distortive cations in asymmetric environments. • The intra-octahedral distortion of the Mo{sup 6+} is influenced by the Se{sup 4+}.« less

Crystal structure of 1-methyl-3-([2,2-dimethyl-4,6-dioxo-1,3-dioxane-5-ylidene]methyl)urea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habibi, A., E-mail: habibi@khu.ac.ir; Ghorbani, H. S.; Bruno, G.

2013-12-15

The crystal structure of 1-Methyl-3-([2,2-dimethyl-4,6-dioxo-1,3-dioxane-5-ylidene]methyl)urea (C{sub 9}H{sub 12}N{sub 2}O{sub 5}) has been determined by single crystal X-ray diffraction analysis. The crystals are monoclinic, a = 5.3179(2), b = 18.6394(6), c =10.8124(3) Å, β = 100.015(2)°, Z = 4, sp. gr. P2{sub 1}/c, R = 0.0381 for 2537 reflections with I > 2σ(I). Except for C(CH{sub 3}){sub 2} group, the molecule is planar. The structure is stabilized by inter- and intramolecular N-H...O hydrogen bonds and weak C-H...O interactions.

Crystal structures of complexes of the cys-syn-cys isomer of dicyclohexano-18-crown-6 with oxonium hexafluorotantalate and oxonium hexafluoroniobate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fonari, M. S.; Alekseeva, O. A.; Furmanova, N. G.

2007-03-15

The crystal structures of [(cys-syn-cys-dicyclohexano-18-crown-6 . H{sub 3}O)][TaF{sub 6}] and [(cys-syn-cys-dicyclohexano-18-crown-6 . H{sub 3}O)][NbF{sub 6}] complex compounds are determined using X-ray diffraction analysis. The tantalum complex has two polymorphic modifications, namely, the monoclinic (I) and triclinic (II) modifications. The unit cell parameters of these compounds are as follows: a = 8.507(4) A, b = 11.947(5) A, c = 27.392(12) A, {beta} = 93.11(1) deg., Z = 4, and space group P2{sub 1}/n for modification I; and a = 10.828(1) A, b = 11.204(1) A, c = 12.378(1) A, {alpha} = 72.12(1) deg., {beta} = 79.40(1) deg., {gamma} = 73.70(1) deg.,more » Z = 2, and space group P-1 for modification II. The triclinic niobium complex [(cys-syn-cys-dicyclohexano-18-crown-6 . H{sub 3}O)][NbF{sub 6}] (III) with the unit cell parameters a = 10.796(3) A, b = 11.183(3) A, c = 12.352(3) A, {alpha} = 72.364(5) deg., {beta} = 79.577(5) deg., {gamma} = 73.773(4) deg., Z = 2, and space group P-1 is isostructural with tantalum complex II. The structures of all three complexes are ionic in character. The oxonium cation in complexes I-III is encapsulated by the crown ether and thus forms one ordinary and two bifurcated hydrogen bonds with the oxygen atoms of the crown ether. This macrocyclic cation is bound to the anions through the C-H...F contacts (H...F, 2.48-2.58 A). The conformation of the macrocycle in complex I differs substantially from that in complex II (III)« less

Synthetic and structural investigations of mercurous and mercuric organophosphonates and phenylarsonates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Padalwar, Nitin Balkrushna; Vidyasagar, Kanamaluru

2016-11-15

The following twelve mercurous and mercuric organophosphomates, bis/diphosphonates and phenylarsonates have been isolated and structurally characterized by single crystal X-ray diffraction, {sup 13}C-and {sup 31}P NMR, infrared and Raman spectroscopic methods: Hg{sub 2}(HO{sub 3}PC{sub 6}H{sub 5}){sub 2}(1), Hg{sub 2}(HO{sub 3}P(C{sub 6}H{sub 4})PO{sub 3}H)(2), Hg{sub 2}(HO{sub 3}P(C{sub 6}H{sub 4}){sub 2}PO{sub 3}H)(3), Hg{sub 2}(HO{sub 3}P(CH{sub 2}){sub 4}PO{sub 3}H)(4), Hg{sub 2}(O{sub 3}PC{sub 6}H{sub 5})·H{sub 2}O(5), (Hg{sub 2}){sub 2}(O{sub 3}P(CH{sub 2}){sub 2}PO{sub 3})(6), (Hg{sub 2}){sub 2}(O{sub 3}P(CH{sub 2}){sub 3}PO{sub 3})(7), Hg(O{sub 3}PC{sub 6}H{sub 5})·H{sub 2}O(8), Hg(O{sub 3}PCH{sub 2}C{sub 6}H{sub 5})·H{sub 2}O(9), Hg(O{sub 3}AsC{sub 6}H{sub 5})·H{sub 2}O(10), Hg{sub 3}(O{sub 3}AsC{sub 6}H{sub 5}){sub 2}(HO{sub 3}AsC{sub 6}H{submore » 5}){sub 2}(11) and (Hg{sub 2})Hg{sub 3}(O{sub 3}P(C{sub 6}H{sub 4})PO{sub 3}){sub 2}·2H{sub 2}O(12). Compounds 1–7 are the first examples of mercurous phosphonates and di/bisphosphonates. They contain Hg{sub 2}O{sub 6} units, which consist of Hg{sub 2}{sup 2+} cations with Hg-Hg bond of ~2.5 Å length. Phenylphosphonates 1 and 5 are layered compounds, whereas bis/diphosphonates 2, 3, 4, 6 and 7 have pillared-layered and three-dimensional structures. Compounds 8–11 are layered mercuric phosphonates and phenylarsonates. Compound 12 is a three-dimensional mixed-valent mercury phenylenebisphosphonate. - Graphical abstract: The first examples of mercurous organophosphonates and organodiphosphonates have layered, pillared-layered and three-dimensional structures.« less

Atomic data from the iron project. 3: Rate coefficients for electron impact excitation of boron-like ions: Ne VI, Mg VIII, Al IX, Si X, S XII, Ar XIV, Ca XVI and Fe XXII

NASA Technical Reports Server (NTRS)

Zhang, Hong Lin; Graziani, Mark; Pradhan, Anil K.

1994-01-01

Collison strengths and maxwellian averaged rate coefficients have been calculated for the 105 transitions among all 15 fine structure levels of the 8 LS terms 2s(sup 2) 2 P(P-2(sup 0 sub 1/, 3/2)), 2s2p(sup 2)(P-4(sub 1/2,3/2,5/2), D-2(sub 3/2, 5/2), S-2(sub 1/2), P-2(sub 1/2, 3/2)), 2p(sup 3)(S-4(sup 0)(sub 3/2), D-2(sup 0 sub 3/2, 5/2), P-2(sup 0 sub 1/2, 3/2)) in highly- charged B-like Ne, Mg, Al, Si, S, Ar, Ca and Fe. Rate coefficients have been tabulated at a wide range of temperatures, depending on the ion charge and abundance in plasma sources. Earlier work for O IV has also been extended to include the high temperature range. A brief discussion of the calculations, sample results, and comparison with earlier works is also given. While much of the new data should be applicable to UV spectral diagnostics, the new rates for the important ground state fine structure transition P-2(sup 0 sub 1/2)-P-2(sup 0 sub 3/2) should result in significant revision of the IR cooling rates in plasmas where B-like ions are prominent constituents, since the new rate coefficients are generally higher by several factors compared with the older data.

Hygroscopic La[B{sub 5}O{sub 8}(OH)]NO{sub 3}·2H{sub 2}O: Insight into the evolution of borate fundamental building blocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Biao-Chun, E-mail: zhaobiaochun@sohu.com; Sun, Wei, E-mail: 421221789@qq.com; Ren, Wei-Jian, E-mail: 935428502@qq.com

2013-10-15

Borates have exceptionally diverse fundamental building blocks (FBBs), but factors controlling the formation of borate FBBs are poorly understood. The title compound La[B{sub 5}O{sub 8}(OH)]NO{sub 3}·2H{sub 2}O crystallizes in the space group P2{sub 1}/n with a=6.5396(12) Å, b=15.550(3) Å, c=10.6719(19) Å, β=90.44(1)° and Z=4 at 173(2) K. Its structure has been refined from single-crystal X-ray diffraction data to R{sub 1}=0.049 (for 2465) and wR{sub 2}=0.173 (for 2459 I>2σ(I)). This structure analysis and first-principles calculations show that the change of the FBB from 3Δ2□ in the title compound to 2Δ3□ in La[B{sub 5}O{sub 8}(OH)(H{sub 2}O)]NO{sub 3}·2H{sub 2}O is accompanied by amore » rotation of the NO{sub 3} group. FTIR, Rietveld and thermal analysis results show that the hygroscopic title compound is partially changed to La[B{sub 5}O{sub 8}(OH)(H{sub 2}O)]NO{sub 3}·2H{sub 2}O, with the conversion of [BO{sub 3}] to [BO{sub 3}(H{sub 2}O)] by water absorption. - Graphical abstract: The change of fundamental building blocks from La[B{sub 5}O{sub 8}(OH)]NO{sub 3}·2H{sub 2}O to La[B{sub 5}O{sub 8}(OH)(H{sub 2}O)]NO{sub 3}·2H{sub 2}O is accompanied by a rotation of the NO{sub 3} group . Display Omitted - Highlights: • Synthesis of a new hydrous lanthanum polyborate nitrate. • Single-crystal XRD structure with the 3Δ2⎕ FBB and an oriented NO{sub 3} group. • DFT calculations locate the H positions in three lanthanide polyborate nitrates. • Rietveld, FTIR and DFT results show hygroscopicity changes the FBBs.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, J., E-mail: zhj@ynu.edu.cn; School of Physical Science and Technology, Yunnan University, Kunming 650091; Xu, L.J., E-mail: 825891915@qq.com

Highlights: • The (Yb, N)-TiO{sub 2} nanoparticles were prepared and characterized. • The spectrum absorption region of (Yb, N)-TiO{sub 2} is red-shifted to visible light. • The recombination of the photo-generated electron–hole pairs of (Yb, N)-TiO{sub 2} is suppressed. • The photocatalytic activity of (Yb, N)-TiO{sub 2} is more higher than that of TiO{sub 2}-P25, N-TiO{sub 2} and the Yb-TiO{sub 2}. - Abstract: (Yb, N)-TiO{sub 2} photocatalyst has been synthesized by sol–gel method combined with microwave chemical synthesis. Also, the efficiency of the (Yb, N)-TiO{sub 2} as a photocatalyst for the degradation of methylene blue (MB) using visible light irradiationmore » has been evaluated. The prepared samples were characterized by XRD, TEM, XPS, UV–vis-DRS and PL. The results show that the (Yb, N)-TiO{sub 2} photocatalyst has the anatase TiO{sub 2} crystalline phase. The TEM micrograph demonstrated that the average particle size of the sample was about 12 nm. The band-gap energy absorption edge shifted to longer wavelength as compared to commercial TiO{sub 2}-P25, N-TiO{sub 2} and the Yb-TiO{sub 2} prepared by our group. Results of degradation revealed that the (Yb, N)-TiO{sub 2} has shown much more higher photocatalytic activity than that of the TiO{sub 2}-P25, the N-TiO{sub 2} and the Yb-TiO{sub 2} under the visible light.« less

Characterization of protoberberine analogs employed as novel human P2X{sub 7} receptor antagonists

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ga Eun; Lee, Won-Gil; Lee, Song-Yi

The P2X{sub 7} receptor (P2X{sub 7}R), a member of the ATP-gated ion channel family, is regarded as a promising target for therapy of immune-related diseases including rheumatoid arthritis and chronic pain. A group of novel protoberberine analogs (compounds 3-5), discovered by screening of chemical libraries, was here investigated with respect to their function as P2X{sub 7}R antagonists. Compounds 3-5 non-competitively inhibited BzATP-induced ethidium ion influx into hP2X{sub 7}-expressing HEK293 cells, with IC{sub 50} values of 100-300 nM. This antagonistic action on the channel further confirmed that both BzATP-induced inward currents and Ca{sup 2+} influx were strongly inhibited by compounds 3-5more » in patch-clamp and Ca{sup 2+} influx assays. The antagonists also effectively suppressed downstream signaling of P2X{sub 7} receptors including IL-1{beta} release and phosphorylation of ERK1/2 and p38 proteins in hP2X{sub 7}-expressing HEK293 cells or in differentiated human monocytes (THP-1 cells). Moreover, IL-2 secretion from CD3/CD28-stimulated Jurkat T cell was also dramatically inhibited by the antagonist. These results imply that novel protoberberine analogs may modulate P2X{sub 7} receptor-mediated immune responses by allosteric inhibition of the receptor. - Graphical abstract: Display Omitted« less

Synthesis and crystal structure of LiCuFe{sub 2}(VO{sub 4}){sub 3} by Rietveld method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belik, A.A.

1999-10-01

A new triple vanadate LiCuFe{sub 2}(VO{sub 4}){sub 3} was synthesized by a solid-state method. The compound is isotypic with mineral howardevansite, NaCuFe{sub 2}(VO{sub 4}){sub 3}, and crystallizes in a triclinic system (space group P{bar 1} (No. 2); a = 8.1484(5), b = 9.8024(7), c = 6.6355(4) {angstrom}, {alpha} = 103.832(3), {beta} = 102.353(3), {gamma} = 106.975(3), V = 468.68 {angstrom}{sup 3}, Z = 2). Crystal structure of LiCuFe{sub 2}(VO{sub 4}){sub 3} was refined by Rietveld method with R{sub WP} = 2.32%, R{sub P} = 1.76%, R{sub I} = 2.82%, S = 1.55, using X-ray diffraction. The crystal structure has fivemore » independent cation sites. Lithium cations are located in the cavities M(1)O{sub 6} and M(5)O{sub 10}, which form infinite chains in the [001] direction and are linked through a common face. The lithium cation in the M(1)O{sub 6} cavity has a square planar coordination. The lithium cation in the M(5)O{sub 10} cavity is strongly displaced up to 1.2 {angstrom} from the special position (0, 0, 0.5) to a half-occupied general position (0.037, 0.087, 0.40).« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aoki, Ken-ichi; Tanaka, Nobutada, E-mail: ntanaka@pharm.showa-u.ac.jp; Ishikura, Shuhei

Pig heart carbonyl reductase has been crystallized in the presence of NADPH. Diffraction data have been collected using synchrotron radiation. Pig heart carbonyl reductase (PHCR), which belongs to the short-chain dehydrogenase/reductase (SDR) family, has been crystallized by the hanging-drop vapour-diffusion method. Two crystal forms (I and II) have been obtained in the presence of NADPH. Form I crystals belong to the tetragonal space group P4{sub 2}, with unit-cell parameters a = b = 109.61, c = 94.31 Å, and diffract to 1.5 Å resolution. Form II crystals belong to the tetragonal space group P4{sub 1}2{sub 1}2, with unit-cell parameters amore » = b = 120.10, c = 147.00 Å, and diffract to 2.2 Å resolution. Both crystal forms are suitable for X-ray structure analysis at high resolution.« less

Conformational stability and force field of short-chain linear chlorophosphazenes: MNDO calculations, {sup 31}P NMR, vibrational spectra, and normal coordinate analyses of Cl{sub 3}PN(PCl{sub 2}N){sub n}P(O)Cl{sub 2} and [Cl{sub 3}PN(PCl{sub 2}N){sub n}PCl{sub 3}][PCl{sub 6}] (n = 1,2)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bougeard, D.; Bremard, C.; De Jaeger, R.

1992-10-29

The Raman spectra of Cl{sub 3}PN(PCl{sub 2}N){pi}P(O)Cl{sub 2} and [Cl{sub 3}PN(PCl{sub 2}N){pi}PCl{sub 3}]{sup +}PCl{sub 6}{sup {minus}} (n = 1,2) were recorded in the solid and liquid states at different temperatures. The qualitative depolarization ratios were obtained in the liquid phase. A {sup 31}P NMR study for the molecular compounds showed a coalescence phenomenon near 220 K. The potential energy around the PN bonds for the Cl{sub 3}PN(PCl{sub 2}N)P(O)Cl{sub 2} molecule and [Cl{sub 3}PN(PCl{sub 2}N){sub 2}PCl{sub 3}]{sup +} cation are derived from MNDO (modified neglect of diatomic overlap) calculations. The stable conformations are found to be trans-cis for Cl{sub 3}PN(PCl{sub 2}N)P(O)Cl{submore » 2} and [Cl{sub 3}PN(PCl{sub 2}N){sub 2}PCl{sub 3}]{sup +}. The calculated structural parameters agree well with the X-ray experimental data. The frequencies obtained by normal coordinate analysis are in good agreement with the observed ones. The MNDO calculation of the harmonic force field is in reasonable agreement with the experimental values. The force constant values assigned to torsional modes around the PN bonds correspond to low barriers for the internal rotations. The easy internal rotation around the P-N and P{double_bond}N bonds can explain the flexibility of the phosphazene backbone and the elastomeric properties of the phosphazene polymers. 46 refs., 6 figs., 3 tabs.« less

THE PERIOD RATIO FOR STANDING KINK AND SAUSAGE MODES IN SOLAR STRUCTURES WITH SIPHON FLOW. I. MAGNETIZED SLABS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li Bo; Habbal, Shadia Rifai; Chen Yanjun, E-mail: bbl@sdu.edu.cn

2013-04-20

In the applications of solar magneto-seismology, the ratio of the period of the fundamental mode to twice the period of its first overtone, P{sub 1}/2P{sub 2}, plays an important role. We examine how field-aligned flows affect the dispersion properties, and hence the period ratios, of standing modes supported by magnetic slabs in the solar atmosphere. We numerically solve the dispersion relations and devise a graphic means to construct standing modes. For coronal slabs, we find that the flow effects are significant for the fast kink and sausage modes alike. For the kink ones, they may reduce P{sub 1}/2P{sub 2} bymore » up to 23% compared with the static case, and the minimum allowed P{sub 1}/2P{sub 2} can fall below the lower limit analytically derived for static slabs. For the sausage modes, while introducing the flow reduces P{sub 1}/2P{sub 2} by typically {approx}< 5% relative to the static case, it significantly increases the threshold aspect ratio only above which standing sausage modes can be supported, meaning that their detectability is restricted to even wider slabs. In the case of photospheric slabs, the flow effect is not as strong. However, standing modes are distinct from the coronal case in that standing kink modes show a P{sub 1}/2P{sub 2} that deviates from unity even for a zero-width slab, while standing sausage modes no longer suffer from a threshold aspect ratio. We conclude that transverse structuring in plasma density and flow speed should be considered in seismological applications of multiple periodicities to solar atmospheric structures.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yakubovich, O. V., E-mail: yakubol@geol.msu.ru; Biralo, G. V.; Dimitrova, O. V.

The crystal structure of the (Al,V){sub 4}(P{sub 4}O{sub 12}){sub 3} solid solution, obtained in the single-crystal form by hydrothermal synthesis in the Al(OH){sub 3}-VO{sub 2}-NaCl-H{sub 3}PO{sub 4}-H{sub 2}O system, has been solved by X-ray diffraction analysis (Xcalibur-S-CCD diffractometer, R = 0.0257): a = 13.7477(2) Angstrom-Sign , sp. gr. I 4 bar 3d, Z = 4, and {rho}{sub calcd} = 2.736 g/cm{sup 3}. It is shown that the crystal structure of the parent cubic Al{sub 4}(P{sub 4}O{sub 12}){sub 3} modification can formally be considered an archetype for the formation of double isosymmetric tetraphosphates on its basis.

Synthesis, crystal structure and magnetic characterization of metal(II) coordination polymers based on 2-carboxyethylphosphonic acid and 1,10-phenanthroline (metal=Cu, Co, Cd)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandez-Zapico, Eva; Montejo-Bernardo, Jose Manuel; D'Vries, Richard

2011-12-15

Three non-isostructural metal(II) coordination polymers (metal=copper, cobalt, cadmium) were synthesized under the same mild hydrothermal conditions (T=408 K) by mixture of the corresponding metal acetate with 2-carboxyethylphosphonic acid and 1,10-phenanthroline (1:1:1 M ratio) and their structures were determined by single-crystal X-ray diffraction. Cu{sub 2}(HO{sub 3}PCH{sub 2}CH{sub 2}COO){sub 2}(C{sub 12}H{sub 8}N{sub 2}){sub 2}(H{sub 2}O){sub 2} and Cd{sub 2}(HO{sub 3}PCH{sub 2}CH{sub 2}COO){sub 2}(C{sub 12}H{sub 8}N{sub 2}){sub 2} are triclinic (space group P-1) with a=7.908(5) A, b=10.373(5) A, c=11.515(5) A, {alpha}=111.683(5) Degree-Sign , {beta}=95.801(5) Degree-Sign , {gamma}=110.212(5) Degree-Sign (T=120 K), and a=8.162(5) A, b=9.500(5) A, c=11.148(5) A, {alpha}=102.623(5) Degree-Sign , {beta}=98.607(5) Degree-Sign ,more » {gamma}=113.004(5) Degree-Sign (T=293 K), respectively. In contrast, [Co{sub 2}(HO{sub 3}PCH{sub 2}CH{sub 2}COO){sub 2}(C{sub 12}H{sub 8}N{sub 2}){sub 2}({mu}-OH{sub 2})](H{sub 2}O) is orthorhombic (space group Pbcn) with a=21.1057(2) A, b=9.8231(1) A, c=15.4251(1) A (T=120 K). For these three compounds, structural features, including H-bond network and the {pi}-{pi} stacking interactions, and thermal stability are reported and discussed. None of the materials present a long-range magnetic order in the range of temperatures investigated from 300 K down to 1.8 K. - Graphical abstract: In same synthetic conditions, both the chemical and structural features of three transition metal(II) coordination polymers based on 2-carboxyethylphosphonate and 1-10 Prime -phenanthroline are influenced by the metal cation characteristics, leading to non-homologous materials with different properties, which show the high chemical versatility of this interesting system. Highlights: Black-Right-Pointing-Pointer Non-isostructural metal coordination polymers were synthesized under mild hydrothermal conditions. Black-Right-Pointing-Pointer Ligand's flexibility provides the opportunity to design compounds with tailored properties. Black-Right-Pointing-Pointer Structural changes in the secondary building units are induced by metal features.« less

Crystallization and preliminary X-ray crystallographic analysis of Escherichia coli glutaredoxin 2 in complex with glutathione and of a cysteine-less variant without glutathione

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheng, Ju; Ye, Jun; Rosen, Barry P., E-mail: brosen@med.wayne.edu

2007-04-01

Glutaredoxin 2 from E. coli was cocrystallized with glutathione and data were collected to 1.60 Å. A mutant with the active-site residues Cys9 and Cys12 changed to serine was crystallized in the absence of glutathione and data were collected to 2.4 Å. Glutaredoxin 2 (Grx2) from Escherichia coli is larger in size than classical glutaredoxins. It is extremely efficient in the catalysis of reduced glutathione-dependent disulfide reduction. A complex of Grx2 with reduced glutathione (GSH) has been crystallized. Data were collected to 1.60 Å. The crystals belong to space group P3{sub 2}21, with one Grx2–GSH complex in the asymmetric unit.more » The unit-cell parameters are a = b = 50.10, c = 152.47 Å. A Grx2 mutant, C9S/C12S, which cannot form a disulfide bond with GSH was also crystallized. The crystals diffracted to 2.40 Å and belong to space group P2{sub 1}2{sub 1}2{sub 1}, with one molecule in the asymmetric unit. The unit-cell parameters are a = 28.16, b = 78.65, c = 89.16 Å.« less

A new modification of an old framework: Hofmann layers with unusual tetracyanidometallate groups

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keene, Tony D.; Murphy, Michael J.; Price, Jason R.

2012-05-10

Cyanidometallate complexes are highly versatile building units for the generation of functional porous materials. Here we report five new pillared Hofmann layer compounds incorporating the tetracyanidometallates [MoO(CN){sub 4}]{sup 2-} and [MnN(CN){sub 4}]{sup 2-}. These metalloligands, which are new to this class of materials, have been combined with divalent 1st-row transition metals to produce Hofmann layers that are linked into three-dimensional frameworks by ditopic bridging dipyridyls. We report the structures and anomalous thermal expansion properties of five new materials: [Mn(H{sub 2}O)(bpy){sub 1/2}{l_brace}MoO(CN){sub 4}(bpy){sub 1/2}{r_brace}] {center_dot} 2H{sub 2}O (1), [Mn(H{sub 2}O)(bpy){sub 1/2}{l_brace}MnN(CN){sub 4}(bpy){sub 1/2}{r_brace}] {center_dot} 2H{sub 2}O (2), [Fe(H{sub 2}O)(bpy){sub 1/2}{l_brace}MnN(CN){sub 4}(bpy){submore » 1/2}{r_brace}] {center_dot} 2H{sub 2}O (3), [Co(H{sub 2}O)(bpy){sub 1/2}{l_brace}MnN(CN){sub 4}(bpy){sub 1/2}{r_brace}] {center_dot} 2H{sub 2}O (4) and [{l_brace}Mn(H{sub 2}O){sub 2}{r_brace}{sub 1/2}{l_brace}Mn(bpa){sub 2}{r_brace}{sub 1/2}{l_brace}MoO(CN){sub 4}(bpa){sub 1/2}{r_brace}] {center_dot} MeOH (5), (where bpy = 4,4'-bipyridine and bpa = 4,4'-bipyridylacetylene).« less

Neutron structure and inelastic-neutron-scattering and theoretical studies of Mo(CO)(H[sub 2])[(C[sub 6]D[sub 5])[sub 2]PC[sub 2]H[sub 4]P(C[sub 6]D[sub 5])[sub 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubas, G.J.; Burns, C.J.; Eckert, J.

1993-01-27

The synthesis and characterization of derivatives of Mo(CO)(R[sub 2]PC[sub 2]H[sub 4]PR[sub 2])[sub 2] (R = Et, i-Bu, Ph, Et-Ph) and their reactions with H[sub 2], N[sub 2], and SO[sub 2] are reported. For R = Et and i-Bu, the H[sub 2] oxidatively adds to give dihydrides, but for R = Ph, a [eta][sup 2]-H[sub 2] complex is formed. Single-crystal neutron diffraction of Mo(CO)(H[sub 2])(Ph[sub 2]PC[sub 2]H[sub 4]PPh[sub 2])[sub 2] (as a 4.5-benzene solvate with all Ph groups deuterated) at 12 K showed the H-H bond to be oriented trans to the CO and parallel to a P-Mo-P axis, with amore » length close to that of free H[sub 2] (0.74 [Angstrom]). However, the thermal ellipsoids were very large, and inelastic neutron scattering showed that the barrier to rotation of the H[sub 2] is the lowest yet measured, ca. 0.7 kcal/mol. These observations indicate that librational motion of the H[sub 2] is artificially foreshortening the H-H bond length. Application of a correction procedure gave a distance of 0.80-0.85 [Angstrom] as being more likely. Extended Huckel calculations successfully modeled the H[sub 2] coordination and also showed a low rotational barrier (1.4 kcal/mol). Theoretical considerations suggest that the degree of distortion of the MP[sub 4] skeleton is largely responsible for the ability of the complex to bind molecular hydrogen and controls the amount of back-bonding from the metal d-orbital to H[sub 2] [sigma][sup *]. The lack of an elongated H-H bond length or equilibrium with a dihydride tautomer, despite the apparent nearness of the H[sub 2] to cleavage, leads to the conclusion that the reaction coordinate for oxidative addition of H[sub 2] is rather flat until relatively precipitous cleavage of the H[sub 2]. Mo(CO)(H[sub 2])[(C[sub 6]D[sub 5])[sub 2]PC[sub 2]H[sub 4]P(C[sub 6]D[sub 5])[sub 2

Fully quantum-state resolved study of NO{sub 2} photodissociation. Correlated NO({sup 2}{Pi}{sub {Omega}}, {nu} = 0 J,A) + O({sup 3}P{sub j}) distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanov, A.; Bieler, C.R.; Reisler, H.

1995-09-14

Relative O({sup 3}P{sub j} = 2.1.0) spin-orbit populations correlated with specific NO[{sup 2}{Pi}{sub {Omega}} = {1/2}, 3/2; {nu} = 0; f; {Lambda} = {Pi}(A{prime}), {Pi}(A{double_prime})] product states were obtained following photolysis of NO{sub 2} at excess energies E{sup {+-}} = 390, 425, and 1054 cm{sup -1}. These fully quantum state-resolved measurements were carried out by recording spatial profiles of recoiling NO({sup 2}{Pi}{sub {Omega}}, J, {Lambda}) products using polarized radiation for photolysis and state-selective laser ionization detection. The relative O({sup 3}P{sub j}) populations correlated with each NO({sup 2}{Pi}{sub {Omega}}, J, {Lambda}) state show marked fluctuations at each excess energy as amore » function of rotational state and {Lambda}-doublet component. The relative populations also fluctuate as a function of excess energy. The O({sup 3}P{sub j}) spin-orbit population ratios, when averaged over all measurements, exhibit distributions that are colder than statistical, in agreement with previous results. In particular, we find that, on average, O({sup 3}P{sub 1}):O({sup 3}P{sub 2}) population ratios correlated with the ground NO({sup 2}{Pi}{sub {1/2}}) state are colder than the corresponding ratios correlated with the excited NO({sup 2}{Pi}{sub 3/2}) spin-orbit state. These results are in agreement with the state-specific calculations of Katigiri and Kato. 45 refs., 12 figs., 3 tabs.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamashita, T.; Fujino, T.; Masaki, N.

The structural parameters of ..cap alpha..- and ..beta..-CdUO/sub 4/ crystals are determined by x-ray powder diffraction technique. ..cap alpha..-CdUO/sub 4/ is rhombohedral and cell parameters are a = 6.233(3) A and ..cap alpha.. = 36.12(5)/sup 0/. ..beta..-CdUO/sub 4/ crystallizes in a C-centered orthorhombic cell with a = 7.023(4), b = 6.849(3), c = 3.514(2) A. The space groups are R3m for ..cap alpha..-CdUO/sub 4/ and Cmmm for ..beta..-CdUO/sub 4/. ..cap alpha..-CdUO/sub 4/: 1U in (000), 1Cd in (1/2 1/2 1/2), 2O(1) in +-(uuu), 2O(2) in +-(vvv); u = 0.113, v= 0.350, Z = 1. ..beta..-CdUO/sub 4/: 2U in (000; 1/2more » 1/2 0), 2Cd in (1/2 0 1/2; 0 1/2 1/2), 40(1) in (0, +-y, 0; 1/2, 1/2 +-y, 0), 4O(2) in (+-x, 0, 1/2; 1/2 +-x, 1/2, 1/2); x = 0.159, y = 0.278, Z = 2. ..beta..-CdUO/sub 4/ contains collinear uranyl UO/sub 2//sup 2 +/ groups with a U-O(1) distance of 1.91 A, located either along or parallel to the c axis whereas the U-O(1) bond length in ..cap alpha..-CdUO/sub 4/ is 1.98 A which is longer than the usual uranyl bond length.« less

Electrical properties of AC{sub 3}B{sub 4}O{sub 12}-type perovskite ceramics with different cation vacancies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Guizhong; Chen, Zhi; Sun, Xiaojun

2015-05-15

Highlights: • AC{sub 3}B{sub 4}O{sub 12} perovskite with different concentration cation vacancies were prepared. • Cell parameter decreases with the increase of concentration of cation vacancies. • PTCO and CTO remain high dielectric permittivity but depress loss greatly. • Dielectric loss associates with cation vacancies and motion of oxygen vacancies. - Abstract: AC{sub 3}B{sub 4}O{sub 12}-type perovskite CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO), □{sub 0.34}Pr{sub 0.67}Cu{sub 3}Ti{sub 4}O{sub 12} (PCTO), □{sub 1}Cu{sub 3}Ta{sub 2}Ti{sub 2}O{sub 12} (CTTO), □{sub 2}Cu{sub 2}Ta{sub 4}O{sub 12} (CTO) ceramics with different concentration cation vacancies were prepared through traditional solid state reaction method. X-ray diffraction analysis indicatedmore » that CCTO and PCTO are perovskite cubic with space group Im-3 (no. 204) while CTTO and CTO are Pm-3 (no. 200). Cell parameter of the samples dramatically increases with the increase of cation vacancies. Dielectric permittivity of them maintains very high value of ∼10{sup 4} from room temperature to 550 K but the dielectric loss is depressed with the increase of cation vacancies in the same space group. The dielectric properties and conductivity behavior were described by the Debye relaxation and the universal dielectric response, respectively. The effect mechanism of cation vacancy and crystal structure on carrier transposition were discussed.« less

The crystal chemistry of four thorium sulfates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Albrecht, Amanda J.; Sigmon, Ginger E.; Moore-Shay, Laura

2011-07-15

Four thorium sulfate compounds have been synthesized and characterized. [Th(SO{sub 4}){sub 2}(H{sub 2}O){sub 7}].2H{sub 2}O (ThS1) crystallizes in space group P2{sub 1}/m, a=7.2488(4), b=12.1798(7), c=8.0625(5) A, {beta}=98.245(1){sup o}; Na{sub 10}[Th{sub 2}(SO{sub 4}){sub 9}(H{sub 2}O){sub 2}].3H{sub 2}O (ThS2), Pna2{sub 1}, a=17.842(2), b=6.9317(8), c=27.550(3) A; Na{sub 2}[Th{sub 2}(SO{sub 4}){sub 5}(H{sub 2}O){sub 3}].H{sub 2}O (ThS3), C2/c, a=16.639(2), b=9.081(1), c=25.078(3) A, {beta}= 95.322(2){sup o}; [Th{sub 4}(SO{sub 4}){sub 7}(OH){sub 2}(H{sub 2}O){sub 6}].2H{sub 2}O (ThS4), Pnma, a=18.2127(9), b=11.1669(5), c=14.4705(7) A. In all cases the Th cations are coordinated by nine O atoms corresponding to SO{sub 4} tetrahedra, OH groups, and H{sub 2}O groups. The structural unitmore » of ThS1 is an isolated cluster consisting of a single Th polyhedron with two monodentate SO{sub 4} tetrahedra and seven H{sub 2}O groups. A double-wide Th sulfate chain is the basis of ThS2. The structures of ThS3 and ThS4 are frameworks of Th polyhedra and sulfate tetrahedra, and each contains channels that extend through the framework. One of the Th cations in ThS3 is coordinated by a bidentate SO{sub 4} tetrahedron, and ThS4 is unusual in the presence of a pair of Th cations that share a polyhedral face. - Graphical abstract: The structures of four hydrous thorium sulfates are reported that have structural units consisting of finite clusters, chains, and frameworks. Highlights: > Four hydrous thorium sulfates have structural units consisting of finite clusters, chains, and frameworks. > In each the Th cations are coordinated by nine O atoms from SO{sub 4} tetrahedra, OH groups, and H{sub 2}O groups. > The details of the linkages of ThO{sub 9} polyhedra and sulfate tetrahedra vary considerably in these structures.« less

Presence of a monoclinic (Pm) phase in the morphotropic phase boundary region of multiferroic (1 − x)Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} solid solution: A Rietveld study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pandey, Rishikesh, E-mail: akhilesh-bhu@yahoo.com, E-mail: aksingh.mst@itbhu.ac.in; Singh, Akhilesh Kumar, E-mail: akhilesh-bhu@yahoo.com, E-mail: aksingh.mst@itbhu.ac.in

2014-07-28

We present here the results of structural studies on multiferroic (1 − x)Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} solid solution using Rietveld analysis on powder x-ray diffraction data in the composition range 0.35 ≤ x ≤ 0.55. The stability region of various crystallographic phases at room temperature for (1 − x)Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} is determined precisely. Structural transformation from pseudo-cubic (x ≤ 0.40) to tetragonal (x ≥ 0.50) phase is observed via phase coexistence region demarcating the morphotropic phase boundary. The morphotropic phase boundary region consists of coexisting tetragonal and monoclinic structures with space group P4mm and Pm, respectively, stable in composition range 0.41 ≤ x ≤ 0.49 as confirmed by Rietveld analysis. The resultsmore » of Rietveld analysis completely rule out the coexistence of rhombohedral and tetragonal phases in the morphotropic phase boundary region reported by earlier workers. A comparison between the bond lengths for “B-site cations-oxygen anions” obtained after Rietveld refinement, with the bond length calculated using Shannon-Prewitt ionic radii, reveals the ionic nature of B-O (Ni/Ti-O) bonds for the cubic phase and partial covalent character for the other crystallographic phases.« less

Dielectric relaxation in 0-3 PVDF-Ba(Fe{sub 1/2}Nb{sub 1/2})O{sub 3} composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chandra, K. P., E-mail: kpchandra23@gmail.com; Singh, Rajan; Kulkarni, A. R., E-mail: ajit2957@gmail.com

2016-05-06

(1-x)PVDF-xBa(Fe{sub 1/2}Nb{sub 1/2})O{sub 3} ceramic-polymer composites with x = 0.025, 0.05, 0.10, 0.15 were prepared using melt-mixing technique. The crystal symmetry, space group and unit cell dimensions were determined from the XRD data of Ba(Fe{sub 1/2}Nb{sub 1/2})O{sub 3} using FullProf software, whereas crystallite size and lattice strain were estimated using Williamson-Hall approach. The distribution of Ba(Fe{sub 1/2}Nb{sub 1/2})O{sub 3} particles in the PVDF matrix were examined on the cryo-fractured surfaces using a scanning electron microscope. Cole-Cole and pseudo Cole-Cole analysis suggested the dielectric relaxation in this system to be of non-Debye type. Filler concentration dependent real and imaginary parts ofmore » dielectric constant as well as ac conductivity data followed definite trends of exponential growth types of variation.« less

Structure, microstructure and infrared studies of Ba{sub 0.06}(Na{sub 1/2}Bi{sub 1/2}){sub 0.94}TiO{sub 3}-NaNbO{sub 3} ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, Sumit K., E-mail: sumit.sxc13@gmail.com; Singh, S. N., E-mail: snsphyru@gmail.com; Prasad, K., E-mail: k.prasad65@gmail.com

2016-05-06

Lead-free solid solutions (1-x)Ba{sub 0.06}(Na{sub 1/2}Bi{sub 1/2}){sub 0.94}TiO{sub 3}-xNaNbO{sub 3} (0 ≤ x ≤ 1.0) were prepared by conventional ceramic fabrication technique. X-ray diffraction and Rietveld refinement analyses of these ceramics were carried out using X’Pert HighScore Plus software to determine the crystal symmetry, space group and unit cell dimensions. Rietveld refinement revealed that NaNbO{sub 3} with orthorhombic structure was completely diffused into Ba{sub 0.06}(Na{sub 1/2}Bi{sub 1/2}){sub 0.94}TiO{sub 3} lattice having the rhombohedral-tetragonal symmetry. EDS and SEM studies were carried out in order to evaluate the quality and purity of the compounds. SEM images showed a change in grain shapemore » with the increase of NaNbO{sub 3} content. FTIR spectra confirmed the formation of solid solution.« less

Crystallization and preliminary X-ray diffraction of the DEAD-box protein Mss116p complexed with an RNA oligonucleotide and AMP-PNP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Del Campo, Mark; Lambowitz, Alan M.; Texas)

2009-09-02

The Saccharomyces cerevisiae DEAD-box protein Mss116p is a general RNA chaperone which functions in mitochondrial group I and group II intron splicing, translation and RNA-end processing. For crystallization trials, full-length Mss116p and a C-terminally truncated protein (Mss116p/{Delta}598-664) were overproduced in Escherichia coli and purified to homogeneity. Mss116p exhibited low solubility in standard solutions ({le}1 mg ml{sup -1}), but its solubility could be increased by adding 50 mM L-arginine plus 50 mM L-glutamate and 50% glycerol to achieve concentrations of {approx}10 mg ml{sup -1}. Initial crystals were obtained by the microbatch method in the presence of a U{sub 10} RNA oligonucleotidemore » and the ATP analog AMP-PNP and were then improved by using seeding and sitting-drop vapor diffusion. A cryocooled crystal of Mss116p/{Delta}598-664 in complex with AMP-PNP and U{sub 10} belonged to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 88.54, b = 126.52, c = 55.52 {angstrom}, and diffracted X-rays to beyond 1.9 {angstrom} resolution using synchrotron radiation from sector 21 at the Advanced Photon Source.« less

Experimental and Computational Studies of Binding of Dinitrogen, Nitriles, Azides, Diazoalkanes, Pyridine and Pyrazines to M(PR3)2(CO)3 (M=Mo, W; R=Me, iPr)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoff, C.D.; Muckerman, J.; Achord, P.

2009-08-17

The enthalpies of binding of a number of N-donor ligands to the complex Mo(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3} in toluene have been determined by solution calorimetry and equilibrium measurements. The measured binding enthalpies span a range of {approx}10 kcal mol{sup -1}: {Delta}H{sub binding} = -8.8 {+-} 1.2 (N{sub 2}-Mo(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}); -10.3 {+-} 0.8 (N{sub 2}); -11.2 {+-} 0.4 (AdN{sub 3} (Ad = 1-adamantyl)); -13.8 {+-} 0.5 (N{sub 2}CHSiMe{sub 3}); -14.9 {+-} 0.9 (pyrazine = pz); -14.8 {+-} 0.6 (2,6-Me{sub 2}pz); -15.5 {+-} 1.8 (Me{sub 2}NCN); -16.6 {+-} 0.4 (CH{sub 3}CN); -17.0 {+-} 0.4 (pyridine); -17.5 {+-} 0.8more » ([4-CH{sub 3}pz][PF{sub 6}] (in tetrahydrofuran)); -17.6 {+-} 0.4 (C{sub 6}H{sub 5}CN); -18.6 {+-} 1.8 (N{sub 2}CHC(=O)OEt); and -19.3 {+-} 2.5 kcal mol{sup -1} (pz)Mo(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}). The value for the isonitrile AdNC (-29.0 {+-} 0.3) is 12.3 kcal mol{sup -1} more exothermic than that of the nitrile AdCN (-16.7 {+-} 0.6 kcal mol{sup -1}). The enthalpies of binding of a range of arene nitrile ligands were also studied, and remarkably, most nitrile complexes were clustered within a 1 kcal mol{sup -1} range despite dramatic color changes and variation of v{sub CN}. Computed structural and spectroscopic parameters for the complexes Mo(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}L are in good agreement with experimental data. Computed binding enthalpies for Mo(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}L exhibit considerable scatter and are generally smaller compared to the experimental values, but relative agreement is reasonable. Computed enthalpies of binding using a larger basis set for Mo(PMe{sub 3}){sub 2}(CO){sub 3}L show a better fit to experimental data than that for Mo(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}L using a smaller basis set. Crystal structures of Mo(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}(AdCN), W(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}(Me{sub 2}NCN), W(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}(2,6-F{sub 2}C{sub 6}H{sub 3}CN), W(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}(2,4,6-Me{sub 3}C{sub 6}H{sub 2}CN), W(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}(2,6-Me{sub 2}pz), W(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}(AdCN), Mo(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}(AdNC), and W(P{sup i}Pr{sub 3}){sub 2}(CO){sub 3}(AdNC) are reported.« less

Purification, crystallization and preliminary X-ray diffraction studies of UDP-N-acetylglucosamine pyrophosphorylase from Candida albicans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maruyama, Daisuke; Nishitani, Yuichi; Nonaka, Tsuyoshi

2006-12-01

UDP-N-acetylglucosamine pyrophosphorylase was purified and crystallized and X-ray diffraction data were collected to 2.3 Å resolution. UDP-N-acetylglucosamine pyrophosphorylase (UAP) is an essential enzyme in the synthesis of UDP-N-acetylglucosamine. UAP from Candida albicans was purified and crystallized by the sitting-drop vapour-diffusion method. The crystals of the substrate and product complexes both diffract X-rays to beyond 2.3 Å resolution using synchrotron radiation. The crystals of the substrate complex belong to the triclinic space group P1, with unit-cell parameters a = 47.77, b = 62.89, c = 90.60 Å, α = 90.01, β = 97.72, γ = 92.88°, whereas those of the productmore » complex belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 61.95, b = 90.87, c = 94.88 Å.« less

Taggants, method for forming a taggant, and a method for detecting an object

DOEpatents

Harrup, Mason K [Idaho Falls, ID; Stewart, Frederick F [Idaho Falls, ID; Stone, Mark L [Idaho Falls, ID

2012-02-28

A taggant comprising at least one perfluorocarbon compound surrounded by a polyphosphazene compound. The polyphosphazene compound has the chemical structure: ##STR00001## wherein G.sub.1 and G.sub.2 are pendant groups having different polarities, m is an integer greater than or equal to 100, and each of A and B is independently selected from hydrogen, an alkyl, an alkene, an alkoxide, a polyether, a polythioether, a siloxane, and --X(CH.sub.2).sub.nY.sup.1(CH.sub.2)p.sub.1Y.sup.2(CH.sub.2)p.sub.2 . . . Y.sup.i(CH.sub.2)p.sub.iCH.sub.3, where n ranges from 1 to 6, X and Y are independently selected from oxygen, sulfur, selenium, tellurium, and polonium, and p.sub.1 through p.sub.i range from 1 to 6. Cyclic polyphosphazene compounds lacking the A and B groups are also disclosed, as are methods of forming the taggant and of detecting an object.

STEAM REFORMING OF CHLOROCARBONS: CHLORINATED AROMATICS. (R826694C633)

EPA Science Inventory

Effective dechlorination of chloroaromatics, such as C₆H₅Cl, 1,2-C₆H₄Cl₂, 1,3-C₆H₄Cl₂ and 1,2,4-C₆H₃Cl₃, using catalytic steam reforming has been confirmed ...

Physiological characteristics of elite and sub-elite badminton players.

PubMed

Ooi, Cheong Hwa; Tan, Albert; Ahmad, Azwari; Kwong, Kien Weng; Sompong, Ruji; Ghazali, Khairul Aswadi Mohd; Liew, Swee Lee; Chai, Wen Jin; Thompson, Martin William

2009-12-01

The aims of this study were to establish the physical and physiological attributes of elite and sub-elite Malaysian male badminton players and to determine whether these attributes discriminate elite players from sub-elite players. Measurements and tests of basic anthropometry, explosive power, anaerobic recovery capacity, badminton-specific movement agility, maximum strength, and aerobic capacity were conducted on two occasions, separated by at least one day. The elite (n = 12) and sub-elite (n = 12) players' characteristics were, respectively: mean age 24.6 years (s = 3.7) and 20.5 years (s = 0.7); mass 73.2 kg (s = 7.6) and 62.7 kg (s = 4.2); stature 1.76 m (s = 0.07) and 1.71 m (s = 0.05); body fat 12.5% (s = 4.8) and 9.5% (s = 3.4); estimated VO(2max) 56.9 ml . kg(-1) . min(-1) (s = 3.7) and 59.5 ml . kg(-1) . min(-1) (s = 5.2). The elite players had greater maximum absolute strength in one-repetition maximum bench press (P = 0.015) compared with the sub-elite players. There were significant differences in instantaneous lower body power estimated from vertical jump height between the elite and sub-elite groups (P < 0.01). However, there was no significant difference between groups in shuttle run tests and on-court badminton-specific movement agility tests. Our results show that elite Malaysian male badminton players are taller, heavier, and stronger than their sub-elite counterparts. The test battery, however, did not allow us to discriminate between the elite and sub-elite players, suggesting that at the elite level tactical knowledge, technical skills, and psychological readiness could be of greater importance.

The synthesis and structure of a chiral 1D aluminophosphate chain compound: d-Co(en){sub 3}[AlP{sub 2}O{sub 8}].6.5H{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Peng; Li Jiyang; Yu Jihong

2005-06-15

A new chiral one-dimensional (1D) aluminophosphate chain compound [d-Co(en){sub 3}][AlP{sub 2}O{sub 8}].6.5H{sub 2}O (designated AlPO-CJ22) has been hydrothermally synthesized by using the optically pure d-Co(en){sub 3}I{sub 3} complex as the template. Single-crystal structural analysis reveals that its structure is built up from alternating connection of AlO{sub 4} and PO{sub 2}(=O{sub 2}) tetrahedra to form corner-shared Al{sub 2}P{sub 2} four-membered ring (4-MR) chains. The d-Co(en){sub 3}{sup 3+} complex cations extended along the 2{sub 1} screw axis interact with the inorganic chains through hydrogen-bonds of N...O atoms in a helical fashion. Optical rotation measurement shows that AlPO-CJ22 is chiral as with d-Co(en){submore » 3}{sup 3+} complex cations. Crystal data: orthorhombic, I2{sub 1}2{sub 1}2{sub 1}, a=8.5573(8)A, b=22.613(2)A, c=22.605(2)A, Z=8, R{sub 1}=0.067, wR{sub 2}=0.1291, and Flack parameter: -0.02(3). CCDC number: 254179. -0.02(3). CCDC number: 254179.« less

Crystallization and preliminary X-ray diffraction studies of two thermostable α-galactosidases from glycoside hydrolase family 36

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foucault, M.; Watzlawick, H.; Mattes, R.

2006-02-01

The α-galactosidases AgaA, AgaB and AgaA A355E mutant from Geobacillus stearothermophilus have been overexpressed in Escherichia coli. Crystals of AgaB and AgaA A355E have been obtained by the vapour-diffusion method and synchrotron data have been collected to 2.0 and 2.8 Å resolution, respectively. α-Galactosidases from thermophilic organisms have gained interest owing to their applications in the sugar industry. The α-galactosidases AgaA, AgaB and AgaA A355E mutant from Geobacillus stearothermophilus have been overexpressed in Escherichia coli. Crystals of AgaB and AgaA A355E have been obtained by the vapour-diffusion method and synchrotron data have been collected to 2.0 and 2.8 Å resolution,more » respectively. Crystals of AgaB belong to space group I222 or I2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 87.5, b = 113.3, c = 161.6 Å. Crystals of AgaA A355E belong to space group P3{sub 1}21 or P3{sub 2}21, with unit-cell parameters a = b = 150.1, c = 233.2 Å.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sippel, K.; Boehlein, S; Sakai, Y

Mycoplasma genitalium is a human pathogen that is associated with nongonococcal urethritis in men and cervicitis in women. The cloning, expression, purification and crystallization of the protein MG289 from M. genitalium strain G37 are reported here. Crystals of MG289 diffracted X-rays to 2.8 {angstrom} resolution. The crystals belonged to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 49.7, b = 90.9, c = 176.1 {angstrom}. The diffraction data after processing had an overall R{sub merge} of 8.7%. The crystal structure of Cypl, the ortholog of MG289 from M. hyorhinis, has recently been determined, providing amore » reasonable phasing model; molecular replacement is currently under way.« less

Expression, purification, crystallization and preliminary X-ray studies of Vibrio cholerae pseudopilin EpsH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raghunathan, Kannan; Vago, Frank S.; Ball, Terry

2010-01-12

EpsH is a minor pseudopilin protein of the Vibrio cholerae type II secretion system. A truncated form of EpsH with a C-terminal noncleavable His tag was constructed and expressed in Escherichia coli, purified and crystallized by sitting-drop vapor diffusion. A complete data set was collected to 1.71 {angstrom} resolution. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 53.39, b = 71.11, c = 84.64 {angstrom}. There were two protein molecules in the asymmetric unit, which gave a Matthews coefficient V{sub M} of 2.1 {angstrom}{sup 3} Da{sup -1}, corresponding to 41.5% solvent content.

Implications for Extraterrestrial Hydrocarbon Chemistry: Analysis of Ethylene (C{sub 2}H{sub 4}) and D4-Ethylene (C{sub 2}D{sub 4}) Ices Exposed to Ionizing Radiation via Combined Infrared Spectroscopy and Reflectron Time-of-flight Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abplanalp, Matthew J.; Kaiser, Ralf I., E-mail: ra

The processing of the hydrocarbon ice, ethylene (C{sub 2}H{sub 4}/C{sub 2}D{sub 4}), via energetic electrons, thus simulating the processes in the track of galactic cosmic-ray particles, was carried out in an ultrahigh vacuum apparatus. The chemical evolution of the ices was monitored online and in situ utilizing Fourier transform infrared spectroscopy (FTIR) and during temperature programmed desorption, via a quadrupole mass spectrometer utilizing electron impact ionization (EI-QMS) and a reflectron time-of-flight mass spectrometer utilizing a photoionization source (PI-ReTOF-MS). Several previous in situ studies of ethylene ice irradiation using FTIR were substantiated with the detection of six products: [CH{sub 4} (CD{submore » 4})], acetylene [C{sub 2}H{sub 2} (C{sub 2}D{sub 2})], the ethyl radical [C{sub 2}H{sub 5} (C{sub 2}D{sub 5})], ethane [C{sub 2}H{sub 6} (C{sub 2}D{sub 6})], 1-butene [C{sub 4}H{sub 8} (C{sub 4}D{sub 8})], and n -butane [C{sub 4}H{sub 10} (C{sub 4}D{sub 10})]. Contrary to previous gas phase studies, the PI-ReTOF-MS detected several groups of hydrocarbon with varying degrees of saturation: C{sub n}H{sub 2n+2} (n = 4–10), C{sub n}H{sub 2n} ( n = 2–12, 14, 16), C{sub n}H{sub 2n−2} ( n = 3–12, 14, 16), C{sub n}H{sub 2n−4} (n = 4–12, 14, 16), C{sub n}H{sub 2n−6} (n = 4–10, 12), C{sub n}H{sub 2n−8} ( n = 6–10), and C{sub n}H{sub 2n−10} ( n = 6–10). Multiple laboratory studies have shown the facile production of ethylene from methane, which is a known ice constituent in the interstellar medium. Various astrophysically interesting molecules can be associated with the groups detected here, such as allene/methylacetylene (C{sub 3}H{sub 4}) or 1, 3-butadiene (C{sub 4}H{sub 6}) and its isomers, which have been shown to lead to polycyclic aromatic hydrocarbons. Finally, several hydrocarbon groups detected here are unique to ethylene ice versus ethane ice and may provide understanding of how complex hydrocarbons form in astrophysical environments.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bang, Hyunjin; Kim, Youngmee; Kim, Seri

We found new synthetic routes to obtain 1-D quaternary thiophosphate compounds and a 0-D molecular complex containing a Nb{sub 2}S{sub 4} core from a 2-D ternary thiophosphate, Nb{sub 4}P{sub 2}S{sub 21}. When Nb{sub 4}P{sub 2}S{sub 21} was reacted with alkali metal halides (ACl; A=Na, K, Rb, Cs) or TlCl at 500-700 deg. C, the -S-S-S- bridges in 2-D Nb{sub 2}PS{sub 10}-S-S{sub 10}PNb{sub 2} were excised to form a 1-D chain, and cations were inserted between the chains to form ANb{sub 2}PS{sub 10} (A=Na, K, Rb, Cs, Tl). We also found that thallium chloride (TlCl) is an excellent reagent for furthermore » excision, and it substitutes chloride ligands for the sulfur ligands of 2-D Nb{sub 4}P{sub 2}S{sub 21} to form the molecular complex Tl{sub 5}[Nb{sub 2}S{sub 4}Cl{sub 8}]Cl. Crystal data for TlNb{sub 2}PS{sub 10}: monoclinic, Pn, a=6.9452(11) A, b=7.3761(12) A, 12.873(2) A, {beta}=104.472(3){sup o}, and Z=2. Crystal data for Tl{sub 5}[Nb{sub 2}S{sub 4}Cl{sub 8}]Cl: orthorhombic, Immm, a=7.001(5) A, b=9.509(7) A, c=15.546(11) A, and Z=2. - Graphical abstract: We developed new synthetic routes to obtain 1-D quaternary thiophosphate compounds and a molecular complex containing a Nb{sub 2}S{sub 4} core from a 2-D ternary thiophosphate, Nb{sub 4}P{sub 2}S{sub 21}. When Nb{sub 4}P{sub 2}S{sub 21} was reacted with alkali metal halides or TlCl, the -S-S-S- bridges in 2-D Nb{sub 2}PS{sub 10}-S-S{sub 10}PNb{sub 2} were excised to form a 1-D chain, and cations were inserted between the chains.« less

Fully quantal calculation of H{sub 2} translation-rotation states in the (p-H{sub 2}){sub 2}@5{sup 12}6{sup 4} clathrate hydrate inclusion compound

DOE Office of Scientific and Technical Information (OSTI.GOV)

Felker, Peter M., E-mail: felker@chem.ucla.edu

2014-11-14

The quantal translation-rotation (TR) states of the (p-H{sub 2}){sub 2}@5{sup 12}6{sup 4} clathrate hydrate inclusion compound have been computed. The ten-dimensional problem (in the rigid-cage and rigid-H{sub 2} approximation) is solved by first approximating the H{sub 2} moieties as spherically symmetric and solving for their 6D translational eigenstates. These are then combined with H{sub 2} free rotational states in a product basis that is used to diagonalize the full TR hamiltonian. The computed low-energy eigenstates have translational components that are essentially identical to the 6D translational eigenstates and rotational components that are 99.9% composed of rotationally unexcited H{sub 2} moieties.more » In other words, TR coupling is minimal for the low-energy states of the species. The low-energy level structure is found to be substantially more congested than that of the more tightly packed (p-H{sub 2}){sub 4}@5{sup 12}6{sup 4} clathrate species. The level structure is also shown to be understandable in terms of a model of (H{sub 2}){sub 2} as a semirigid diatomic species consisting of two spherically symmetric H{sub 2} pseudo-atoms.« less

Study on the energy band structure and photoelectrochemical performances of spinel Li{sub 4}Ti{sub 5}O{sub 12}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ge, Hao; Tian, Hui; Song, Hua

2015-01-15

Highlights: • Spinel Li{sub 4}Ti{sub 5}O{sub 12} possesses more positive potential of valence band and wider band gap than TiO{sub 2}. • Spinel Li{sub 4}Ti{sub 5}O{sub 12} displays typical n-type semiconductor characteristic and excellent UV-excitateded photocatalysis activity. • Our preliminary study will open new perspectives in investigation of other lithium-based compounds for new photocatalysts. - Abstract: Energy band structure, photoelectrochemical performances and photocatalysis activity of spinel Li{sub 4}Ti{sub 5}O{sub 12} are investigated for the first time in this paper. Li{sub 4}Ti{sub 5}O{sub 12} possesses more positive valence band potential and wider band gap than TiO{sub 2} due to its valencemore » band consisting of Li{sub 1s} and Ti{sub 3d} orbitals mixed with O{sub 2p}. Li{sub 4}Ti{sub 5}O{sub 12} shows typical photocatalysis material characteristics and excellent photocatlytic activity under UV irradiation.« less

Rhenium(V)-oxo complexes of neutral and monoanionic tetraazamacrocycles. X-ray structures of trans-oxohydroxo(1,4,8,11-tetraazacyclotetradecane)rhenium(V) bis(perchlorate)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsang, B.W.; Reibenspies, J.; Martell, A.E.

1993-03-17

The complexes of ReO[sub 2][sup +] and ReO(OH)[sup 2+] with 1,4,8,11-tetraazacyclotetradecane (cyclam) and 1,4,8,11-tetraazacyclotetradecan-2-one (O[sub 1]cyclam) have been synthesized and characterized. The complexes were prepared by ligand exchange reactions of the macrocycles with a variety of starting compounds including ReOCl[sub 3](PPh[sub 3])[sub 2] and ReO[sub 2](en)[sub 2]Cl. The ReO(OH)[sup 2+] complexes have been structurally characterized. ReO(OH)(H[sub [minus]1]O[sub 1]cyclam)ReO[sub 4] crystallizes in the monoclinic P2[sub 1]/n space group with a = 10.308(3) [Angstrom], b = 9.527(2) [Angstrom], c = 17.808(3) [Angstrom], and [beta] = 106.57(2)[degrees]. ReO(OH)(cyclam)(ClO[sub 4])[sub 2] crystallizes in the monoclinic C2/c space group with a = 9.734(4) [Angstrom], bmore » = 16.999(5) [Angstrom], c = 12.187(5) [Angstrom], and [beta] = 106.36[degrees]. The complex ReO(OH)(H[sub [minus]1]O[sub 1]cyclam)ReO[sub 4] has a distorted octahedral structure with one short ReO(oxo) bond and one long ReO(hydroxo) bond (1.685(8) vs 1.970(8) [Angstrom]). The deprotonated amide ReN(sp[sup 2]) bond is shorter than the other three ReN(sp[sup 3]) bond lengths (1.98(1) vs 2.13(3) [Angstrom] (average)). The structure of the ReO(OH)(cyclam)(ClO[sub 4])[sub 2] complex shows no distinction between the lengths of the two ReO(oxo and hydroxo) bonds (1.766(5) [Angstrom]) due to disorder of the oxo and hydroxo groups. Spectroscopic evidence is reported to confirm the presence of both oxo and hydroxo groups coordinated to rhenium. 38 refs., 7 figs., 6 tabs.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Shiyan; Mei, Dajiang, E-mail: meidajiang718@pku.edu.cn; Du, Xin

Ag{sub 1−x}Ga{sub 1−x}Si{sub x}Se{sub 2} solutions with high Si doping level (x=1/2) are considered and new compound AgGaSiSe{sub 4} has been synthesized. It crystallizes in space group Aea2 and possesses very long axis of a=63.06(1)Å. The three-dimensional framework in AgGaSiSe{sub 4} is composed of AgSe{sub 3} trigonal planar units, AgSe{sub 4} tetrahedra and MSe{sub 4}(M=Si, Ga) tetrahedra. AgGaSiSe{sub 4} is a congruently melting compound with the melt temperature of 759 °C. The diffuse reflectance measurements reveal the band gap of 2.63 eV in AgGaSiSe{sub 4} and the value is 0.33 eV larger than that of Ag{sub 3}Ga{sub 3}SiSe{sub 8} (2.30more » eV). - Graphical abstract: The Ag{sub 1−x}Ga{sub 1−x}Si{sub x}Se{sub 2} with high Si doping level (x=1/2) has been studied and the new compound AgGaSiSe{sub 4} was synthesized for the first time. AgGaSiSe{sub 4} crystallizes in a new structure type in space group Aea2 and adopts a three-dimensional framework consisting of AgSe{sub 3} trigonal planar units, AgSe{sub 4} tetrahedra and MSe{sub 4} (M=Si, Ge) tetrahedra. Display Omitted - Highlights: • Study of Ag{sub 1−x}Ga{sub 1−x}Si{sub x}Se{sub 2} with high Si doping level (x=1/2). • Successful synthesis of new compound named AgGaSiSe{sub 4}. • AgGaSiSe{sub 4} crystallizes in space group Aea2 and adopts a three-dimensional framework. • The energy band gap of AgGaSiSe{sub 4} is enlarged compared with Ag{sub 3}Ga{sub 3}SiSe{sub 8}.« less

Water-Free Rare Earth-Prussian Blue Type Analogues: Synthesis, Structure, Computational Analysis, and Magnetic Data of {Ln[superscript III](DMF)[subscript 6]Fe[superscript III](CN)[subcsript 6]}[subscript infinity] (Ln = Rare Earths Excluding Pm)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, Duane C.; Liu, Shengming; Chen, Xuenian

2009-11-04

Water-free rare earth(III) hexacyanoferrate(III) complexes, {l_brace}Ln(DMF){sub 6}({mu}-CN){sub 2}Fe(CN){sub 4}{r_brace}{sub {infinity}} (DMF = N,N-dimethylformamide; Ln = Sm, 1; Eu, 2; Gd, 3; Tb, 4; Dy, 5; Ho, 6; Er, 7; Tm, 8; Yb, 9; Lu, 10; Y, 11; La, 12; Ce, 13; Pr, 14; Nd, 15), were synthesized in dry DMF through the metathesis reactions of [(18-crown-6)K]{sub 3}Fe(CN){sub 6} with LnX{sub 3}(DMF){sub n} (X = Cl or NO{sub 3}). Anhydrous DMF solutions of LnX{sub 3}(DMF){sub n} were prepared at room temperature from LnCl{sub 3} or LnX{sub 3} {center_dot} nH{sub 2}O under a dynamic vacuum. All compounds were characterized by IR, X-raymore » powder diffraction (except for 10), and single crystal X-ray diffraction (except for 2, 7, 10). Infrared spectra reveal that a monotonic, linear relationship exists between the ionic radius of the lanthanide and the {nu}{sub {mu}-CN} stretching frequency of 1-10, 12-15 while 11 deviates slightly from the ionic radius relationship. X-ray powder diffraction data are in agreement with powder patterns calculated from single crystal X-ray diffraction results, a useful alternative for bulk sample confirmation when elemental analysis data are difficult to obtain. Eight-coordinate Ln(III) metal centers are observed for all structures. trans-cyanide units of [Fe(CN){sub 6}]{sup 3-} formed isocyanide linkages to Ln(III) resulting in one-dimensional polymeric chains. Structures of compounds 1-9 and 11 are isomorphous, crystallizing in the space group C2/c. Structures of compounds 12-15 are also isomorphous, crystallizing in the space group P2/n. One unique polymeric chain exists in the structures of 1-9 and 11 while two unique polymeric chains exist in structures of 12-15. One of the polymeric chains of 12-15 is similar to that observed for 1-9, 11 while the other is more distorted and has a shorter Ln-Fe distance. Magnetic susceptibility measurements for compounds 3-6, 8, 11 were performed on polycrystalline samples of the compounds.« less

The effects of inhaled sulfuric acid on pulmonary function in adolescent asthmatics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koenig, J.Q.; Pierson, W.E.; Horike, M.

Ten adolescent subjects with extrinsic asthma and exercise-induced bronchospasm were studied. The subjects were exposed for 30 min at rest followed by 10 min during moderate exercise on a treadmill to either 100 micrograms/m3 sodium chloride (NaCl) or 100 micrograms/m3 sulfuric acid (H/sub 2/SO/sub 4/) droplet aerosols. All exposures were at approximately 75% relative humidity and 22 degrees C. Pulmonary functional measurements were recorded before, during, and after exposure while the subject was seated in a body plethysmograph. Exposure to the NaCl aerosol during exercise produced a small (12%) but significant drop in maximal expiratory flow (V/sub max/75) (p lessmore » than 0.05). However, exposure to the H/sub 2/SO/sub 4/ aerosol produced larger reductions in V/sub max/75 (29%; p less than 0.01) and also significant changes in 3 other parameters of pulmonary function: V/sub max/50, FEV1, and total respiratory resistance (RT). The changes were similar to those reported for exposure to 0.5 ppm of sulfur dioxide in a similar group of adolescents with extrinsic asthma. Our results are the first report of reversible pulmonary functional changes after H/sub 2/SO/sub 4/ exposure in a group of adolescent asthmatic subjects.« less

Bi{sub 6}(SeO{sub 3}){sub 3}O{sub 5}Br{sub 2}: A new bismuth oxo-selenite bromide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berdonosov, Peter S., E-mail: berdonosov@inorg.chem.msu.ru; Olenev, Andrei V.; Kirsanova, Maria A.

2012-12-15

A new bismuth oxo-selenite bromide Bi{sub 6}(SeO{sub 3}){sub 3}O{sub 5}Br{sub 2} was synthesized and structurally characterized. The crystal structure belongs to the triclinic system (space group P1-bar , Z=2, a=7.1253(7) A, b=10.972(1) A, c=12.117(1) A, {alpha}=67.765(7) Degree-Sign , {beta}=82.188(8) Degree-Sign , {gamma}=78.445(7) Degree-Sign ) and is unrelated to those of other known oxo-selenite halides. It can be considered as an open framework composed of BiO{sub x} or BiO{sub y}Br{sub z} polyhedrons forming channels running along [1 0 0] direction which contain the selenium atoms in pyramidal shape oxygen coordination (SeO{sub 3}E). The spectroscopic properties and thermal stability were studied. Themore » new compound is stable up to 400 Degree-Sign C. - graphical abstract: New bismuth oxo-selenite bromide with new open framework structure. Highlights: Black-Right-Pointing-Pointer New bismuth oxo-selenite bromide was found and structurally characterized. Black-Right-Pointing-Pointer Bi{sub 6}(SeO{sub 3}){sub 3}O{sub 5}Br{sub 2} exhibit a new open framework structure type. Black-Right-Pointing-Pointer BiO{sub x} or BiO{sub y}Br{sub z} polyhedrons form channels in the structure which are decorated by [SeO{sub 3}E] groups.« less

Giant strain with low cycling degradation in Ta-doped [Bi{sub 1/2}(Na{sub 0.8}K{sub 0.2}){sub 1/2}]TiO{sub 3} lead-free ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Xiaoming; Tan, Xiaoli, E-mail: xtan@iastate.edu

2016-07-21

Non-textured polycrystalline [Bi{sub 1/2}(Na{sub 0.8}K{sub 0.2}){sub 1/2}](Ti{sub 1−x}Ta{sub x})O{sub 3} ceramics are fabricated and their microstructures and electrical properties are characterized. Transmission electron microscopy reveals the coexistence of the rhombohedral R3c and tetragonal P4bm phases in the form of nanometer-sized domains in [Bi{sub 1/2}(Na{sub 0.8}K{sub 0.2}){sub 1/2}]TiO{sub 3} with low Ta concentration. When the composition is x = 0.015, the electrostrain is found to be highly asymmetric under bipolar fields of ±50 kV/cm. A very large value of 0.62% is observed in this ceramic, corresponding to a large-signal piezoelectric coefficient d{sub 33}* of 1240 pm/V (1120 pm/V under unipolar loading). These values are greater thanmore » most previously reported lead-free polycrystalline ceramics and can even be compared with some lead-free piezoelectric single crystals. Additionally, this ceramic displays low cycling degradation; its electrostrain remains above 0.55% even after undergoing 10 000 cycles of ±50 kV/cm bipolar fields at 2 Hz. Therefore, Ta-doped [Bi{sub 1/2}(Na{sub 0.8}K{sub 0.2}){sub 1/2}]TiO{sub 3} ceramics show great potential for large displacement devices.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmad, Bhat Zahoor; Want, Basharat, E-mail: bawant@kashmiruniversity.ac.in

We investigate the structure and ferroelectric behavior of a lanthanide based metal-organic framework (MOF), [Nd(C{sub 4}H{sub 5}O{sub 6})(C{sub 4}H{sub 4}O{sub 6})][3H{sub 2}O]. X-ray crystal structure analyses reveal that it crystallizes in the P4{sub 1}2{sub 1}2 space group with Nd centres, coordinated by nine oxygen atoms, forming a distorted capped square antiprismatic geometry. The molecules, bridged by tartrate ligands, form a 2D chiral structure. The 2D sheets are further linked into a 3D porous framework via strong hydrogen-bonding scheme (O-H…O ≈ 2.113 Å). Dielectric studies reveal two anomalies at 295 K and 185 K. The former is a paraelectric-ferroelectric transition, and the later is attributed tomore » the freezing down of the motion of the hydroxyl groups. The phase transition is of second order, and the spontaneous polarization in low temperature phase is attributed to the ordering of protons of hydroxyl groups. The dielectric nonlinearity parameters have been calculated using Landau– Devonshire phenomenological theory. In addition, the most recent semiempirical models, Sparkle/PM7, Sparkle/RM1, and Sparkle/AM1, are tested on the present system to assay the accuracy of semiempirical quantum approaches to predict the geometries of solid MOFs. Our results show that Sparkle/PM7 model is the most accurate to predict the unit cell structure and coordination polyhedron geometry. The semiempirical methods are also used to calculate different ground state molecular properties.« less

Purification, crystallization and preliminary X-ray diffraction analysis of the IL-20-IL-20R1-IL-20R2 complex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Logsdon, Naomi J.; Allen, Christopher E.; Rajashankar, Kanagalaghatta R.

2012-02-08

Interleukin-20 (IL-20) is an IL-10-family cytokine that regulates innate and adaptive immunity in skin and other tissues. In addition to protecting the host from various external pathogens, dysregulated IL-20 signaling has been shown to contribute to the pathogenesis of human psoriasis. IL-20 signals through two cell-surface receptor heterodimers, IL-20R1-IL-20R2 and IL-22R1-IL-20R2. In this report, crystals of the IL-20-IL-20R1-IL-20R2 ternary complex have been grown from polyethylene glycol solutions. The crystals belonged to space group P4{sub 1}2{sub 1}2 or P4{sub 3}2{sub 1}2, with unit-cell parameters a = 111, c = 135 {angstrom}, and diffracted X-rays to 3 {angstrom} resolution. The crystallographic asymmetricmore » unit contains one IL-20-IL-20R1-IL-20R2 complex, corresponding to a solvent content of approximately 54%.« less

High thermal expansion sealing glass for use in radio frequency applications

DOEpatents

Kilgo, Riley D.; Brow, Richard K.; Kovacic, Larry

1999-01-01

The present invention provides a glass composition for hermetically sealing to high thermal expansion materials such as aluminum alloys, stainless steels, and copper alloys, which includes between about 10 and about 25 mole percent Na.sub.2 O, between about 10 and about 25 mole percent K.sub.2 O, between about 4 and about 15 mole percent Al.sub.2 O.sub.3, between about 35 and about 50 mole percent P.sub.2 O.sub.5, B.sub.2 O.sub.3 in a concentration not exceeding 10 mole percent, and MXO in a concentration not exceeding 12 mole percent, wherein MXO is a metal oxide selected from the group consisting of PbO, BaO, CaO and MgO or a mixture thereof. This composition is suitable to hermetically seal to components for use in RF-interconnection applications.

Cisplatin Pharmacokinetics in Nontumoral Pig Liver Treated With Intravenous or Transarterial Hepatic Chemoembolization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chabrot, Pascal, E-mail: pchabrot@chu-clermontferrand.fr; Cardot, Jean-Michel; Guibert, Pierre

Purpose: To evaluate cisplatin (CDDP) pharmacokinetics after its intravenous (IV) or intrahepatic arterial administration (IHA) in healthy pigs with or without embolization by absorbable gelatine. Material and Methods: We analysed plasmatic and hepatic drug concentration in four groups of six mini-pigs each according to the modality of administration of CDDP (1 mg/kg): IV, IHA, IHA with partial embolization using absorbable gelatine (IHA-Pe), and IHA with complete embolization (IHA-Te). Unbounded plasmatic and hepatic platinum concentrations were measured. Concentration and pharmacokinetics parameters were compared using analysis of variance. Results: For all groups, there was a rapid and biexponential decrease in free platinummore » concentration. Plasmatic terminal half-life (T{sub 1/2}) was significantly decreased after embolization at 191, 178, 42, and 41 min after IV, IHA, IHA-Pe, and IHA-Te administration, respectively. Maximal plasmatic concentration and systemic exposure to CDDP (AUC{sub 24}) values were significantly decreased after embolization (C{sub max}p = 0.0075; AUC{sub 24}p = 0.0053). Hepatic CDDP concentration rapidly peaked and then decreased progressively. After 24 h, the residual concentration represented 45, 47, 60, and 63 % of C{sub max}, respectively, after IV, IHA, IHA-Pe, and IHA-Te. Hepatic T{sub 1/2} and AUC{sub {infinity}} values were increased after embolization, but the differences were not statistically significant. Conclusion: This preliminary study confirms the feasibility of a pig model to study systemic and hepatic CDDP pharmacokinetics. Systemic exposure is lower after embolization, which could minimize systemic toxicity. Hepatic T{sub 1/2} elimination and hepatic exposition values are increased with IHA compared with IV administration.« less

Plausible explanation for the {Delta}{sub 5/2}{sup +}(2000) puzzle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie Jujun; Department of Physics, Zhengzhou University, Zhengzhou, Henan 450001; Martinez Torres, A.

2011-05-15

From a Faddeev calculation for the {pi}-({Delta}{rho}){sub N{sub 5/2}{sup -}{sub (1675)}} system we show the plausible existence of three dynamically generated I(J{sup P})=3/2(5/2{sup +}) baryon states below 2.3 GeV, whereas only two resonances, {Delta}{sub 5/2{sup +}}(1905)(****) and {Delta}{sub 5/2{sup +}}(2000)(**), are cataloged in the Particle Data Book Review. Our results give theoretical support to data analyses extracting two distinctive resonances, {Delta}{sub 5/2{sup +}}({approx}1740) and {Delta}{sub 5/2{sup +}}({approx}2200), from which the mass of {Delta}{sub 5/2{sup +}}(2000)(**) is estimated. We propose that these two resonances should be cataloged instead of {Delta}{sub 5/2{sup +}}(2000). This proposal gets further support from the possible assignmentmore » of the other baryon states found in the approach in the I=1/2,3/2 with J{sup P}=1/2{sup +},3/2{sup +},5/2{sup +} sectors to known baryonic resonances. In particular, {Delta}{sub 1/2{sup +}}(1750)(*) is naturally interpreted as a {pi}N{sub 1/2{sup -}}(1650) bound state.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan Guosheng; Xiang Xianhong; Guo Wenbo

PurposeTo investigate the influence of uterine artery embolization (UAE) on endometrial microvessel density (MVD) and angiogenesis.MethodsSixty female guinea pigs were divided into two groups, the control group (n = 15) and the UAE treatment group (n = 45). In the UAE group, tris-acryl gelatin microspheres were used to generate embolization. Animals were further divided into three subgroups, A1, A2, and A3 (n = 15 for each subgroup), with uterine specimens collected at 7-15, 16-30, and 31-45 days after UAE, respectively. Immunostaining for factor VIII and CD105 was performed to identify total endometrial MVD (MVD{sub FVIII}) and CD105-positive angiogenesis (MVD{sub CD105})more » at the indicated time points after UAE.ResultsQuantitative analysis revealed that MVD{sub FVIII} significantly decreased in the A1 (11.40 {+-} 2.76, p < 0.05) and A2 (15.37 {+-} 3.06, p < 0.05) groups compared to the control group (19.40 {+-} 2.50), and was restored to normal in the A3 group (18.77 {+-} 2.69). UAE caused a temporal up-regulation of MVD{sub CD105}-positive angiogenesis in the A1 group (9.33 {+-} 2.37, p < 0.05) and the A2 group (11.63 {+-} 1.56, p < 0.05) compared to the control group (7.12 {+-} 1.67), and the MVD{sub CD105} value returned to normal in the A3 group (8.07 {+-} 1.97).ConclusionUAE caused a temporal decrease in endometrial MVD that reversed over time as a result of the increase of CD105-positive angiogenesis. Although the UAE-induced reduction of endometrial MVD was reversible, its long-term effect on endometrial receptivity still needs further study.« less

Structure determination of {alpha}-La{sub 6}W{sub 2}O{sub 15}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chambrier, M-H., E-mail: marie-helene.chambier.etu@univ-lemans.f; Ibberson, R.M.; Goutenoire, F., E-mail: francois.goutenoire@univ-lemans.f

2010-06-15

The structure of the high temperature alpha form of La{sub 6}W{sub 2}O{sub 15} has been determined ab-initio from high temperature laboratory X-ray and neutron time-of-flight data. This tungstate crystallizes in the non-centrosymmetric orthorhombic space group (No. 20) C222{sub 1}, with Z=2, a=12.6250(2) A, b=9.1875(1) A, c=5.9688(1) A. The structure comprises [O{sub 2}La{sub 3}] infinite ribbons and is better described by the structural formula [O{sub 2}La{sub 3}]{sub 2}[WO{sub 5.5}]{sub 2}. Using this description we can understand the strong structural similarity of the present compound with compounds of the general composition BiM{sub 2}AO{sub 6} (M=Cu, Mg, Zn, Mn, Cd, Ca, Pb; A=P,more » As, V) described as [O{sub 2}M{sub 2}Bi][AO{sub 4}]. The [WO{sub 5.5}] entity implies oxygen disorder in the material. - Graphical abstract: Projection of the polyhedra around the tungsten atom. Atoms labelled in grey are occupied at 50%. Short oxygen-oxygen distances are marked. The polyhedra represents WO{sub 5.5} that is related to the structural unit W{sub 2}O{sub 11} unit. Alpha-La{sub 6}W{sub 2}O{sub 15} could be described as [O{sub 2}La{sub 3}]{sub 2}[WO{sub 5.5}]{sub 2}.« less

Stereochemical and electronic control of M-SO/sub 2/ bonding geometry in d/sup 6/ molybdenum and tungsten SO/sub 2/ complexes: novel n/sup 1/reverse arrown/sup 2/ SO/sub 2/ linkage isomerization in Mo(CO)/sub 2/(PPh/sub 3/)/sub 2/(CNR)(SO/sub 2/) and structures of Mo(CO)/sub 3/(P-i-Pr/sub 3/)/sub 2/(SO/sub 2/) and (Mo(CO)/sub 2/(py)(PPh/sub 3/)(. mu. -SO/sub 2/))/sub 2/

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubas, G.J.; Jarvinen, G.D.; Ryan, R.R.

1983-04-06

New complexes, mer,trans,M(CO)/sub 3/(PR/sub 3/)/sub 2/(SO/sub 2/) (M = Mo,W; R = Ph,Cy,i-Pr) (I), cis,trans-Mo(CO)/sub 2/-(PPh/sub 3/)/sub 2/(SO/sub 2/)(L) (L = NCMe,py,CNCy,CN-t-Bu and CN(p-tolyl))(II), and (Mo(CO)/sub 2/(py)(PPh/sub 3/)(..mu..-SO/sub 2/))/sub 2/, have been prepared and characterized by infrared spectroscopy, /sup 17/O and /sup 31/P NMR spectroscopy, and X-ray crystallography. Syntheses for fac-Mo(CO)/sub 3/(n/sup 2/-SO/sub 2/)(LL) (LL = dppe,bpy,phen,2 py) have also been developed. Depending upon L, II has been found to coordinate SO/sub 2/ either in the S-bonded (n/sup 1/ planar) or O,S-bonded (n/sup 2/) geometries. Remarkably, for L = CNCy or CN-t-Bu, II has been found to contain, in themore » solid state, an apparent equimixture of both coordination types. Isomerization of fac-M(CO)/sub 3/(dppe)(n/sup 2/-SO/sub 2/) (M=Mo,w; dppe = 1,2-bis(diphenylphosphino)ethane) to an n/sup 1/-planar SO/sub 2/ form, mer-M(CO)/sub 3/(dppe)(SO/sub 2/), has also been found to occur. Thus, control of the SO/sub 2/ coordination geometry has been achieved by varying either the electronic properties of the ancillary ligands or their disposition with respect to the SO/sub 2/. The X-ray crystal structure of mer,trans-Mo(CO)/sub 3/(P-i-Pr/sub 3/)/sub 2/(SO/sub 2/) revealed n/sup 1/-planar SO/sub 2/ binding, the first example of this geometry for group 6 metals. The M-S distance, 2.239 (3) angstrom, is the longest such distance for this geometry recorded to date. Crystal data: Pbca, Z=8, a=24.712(8) angstrom, b=16.033(6) angstrom, c=14.058(5) angstrom, R=0.079 for 2934 reflections with Igreater than or equal to2sigma(I). The structure of (Mo(CO)/sub 2/(py)(PPh/sub 3/)(..mu..-SO/sub 2/))/sub 2/ showed a novel SO/sub 2/ bridging geometry in which all three atoms of SO/sub 2/ are metal coordinated. Crystal data: P1, Z=1, a=14.883(4) angstrom, b=9.264(2) angstrom, c=10.808(2) angstrom, R=0.039 for 3282 reflections with Igreater than or equal to2sigma(I).« less

Hydrothermal synthesis and structural analysis of new mixed oxyanion borates: Ba{sub 11}B{sub 26}O{sub 44}(PO{sub 4}){sub 2}(OH){sub 6}, Li{sub 9}BaB{sub 15}O{sub 27}(CO{sub 3}) and Ba{sub 3}Si{sub 2}B{sub 6}O{sub 16}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heyward, Carla, E-mail: cheywar@clemson.edu; McMillen, Colin D., E-mail: cmcmill@clemson.edu; Kolis, Joseph, E-mail: kjoseph@clemson.edu

2013-07-15

Several new borate compounds, Ba{sub 11}B{sub 26}O{sub 44}(PO{sub 4}){sub 2}(OH){sub 6} (1), Li{sub 9}BaB{sub 15}O{sub 27}(CO{sub 3}) (2), and Ba{sub 3}Si{sub 2}B{sub 6}O{sub 16} (3) were synthesized containing other hetero-oxyanion building blocks in addition to the borate frameworks. They were all prepared under hydrothermal conditions and characterized by single crystal and powder X-ray diffraction, and IR spectroscopy. Crystal data: For 1; space group P2{sub 1}/c, a=6.8909 (14) Å, b=13.629 (3) Å, c=25.851 (5) Å, β=90.04 (3)°; For 2; space group P-31c, a=8.8599 (13) Å, c=15.148 (3) Å; For 3; space group P-1, a=5.0414 (10) Å, b=7.5602 (15) Å, c=8.5374 (17)more » Å, α=77.15 (3)°, β=77.84 (3)°, γ=87.41 (3)° for 3. Compounds 1 and 2 contain isolated oxyanions [PO{sub 4}]{sup 3−} and [CO{sub 3}]{sup 2−} respectively, sitting in channels created by the borate framework, while structure 3 has the [SiO{sub 4}]{sup 4−} groups directly bonded to the borate groups creating a B–O–Si framework. - Highlights: • Hydrothermal syntheses of three new mixed oxyanion borates are presented. • Ba{sub 11}B{sub 26}O{sub 44}(PO{sub 4}){sub 2}(OH){sub 6} contains isolated [PO{sub 4}]{sup 3−} in voids of the borate framework. • Li{sub 9}BaB{sub 15}O{sub 27}(CO{sub 3}) contains isolated [CO{sub 3}]{sup 2−} in channels created by the framework. • Ba{sub 3}Si{sub 2}B{sub 6}O{sub 16} has direct bonding of [SiO{sub 4}]{sup 4−} and borates creating a B–O–Si framework.« less

Thermodynamic analysis of binary Fe{sub 85}B{sub 15} to quinary Fe{sub 85}Si{sub 2}B{sub 8}P{sub 4}Cu{sub 1} alloys for primary crystallizations of α-Fe in nanocrystalline soft magnetic alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takeuchi, A., E-mail: takeuchi@imr.tohoku.ac.jp; Zhang, Y.; Takenaka, K.

2015-05-07

Fe-based Fe{sub 85}B{sub 15}, Fe{sub 84}B{sub 15}Cu{sub 1}, Fe{sub 82}Si{sub 2}B{sub 15}Cu{sub 1}, Fe{sub 85}Si{sub 2}B{sub 12}Cu{sub 1}, and Fe{sub 85}Si{sub 2}B{sub 8}P{sub 4}Cu{sub 1} (NANOMET{sup ®}) alloys were experimental and computational analyzed to clarify the features of NANOMET that exhibits high saturation magnetic flux density (B{sub s}) nearly 1.9 T and low core loss than conventional nanocrystalline soft magnetic alloys. The X-ray diffraction analysis for ribbon specimens produced experimentally by melt spinning from melts revealed that the samples were almost formed into an amorphous single phase. Then, the as-quenched samples were analyzed with differential scanning calorimeter (DSC) experimentally for exothermicmore » enthalpies of the primary and secondary crystallizations (ΔH{sub x1} and ΔH{sub x2}) and their crystallization temperatures (T{sub x1} and T{sub x2}), respectively. The ratio ΔH{sub x1}/ΔH{sub x2} measured by DSC experimentally tended to be extremely high for the Fe{sub 85}Si{sub 2}B{sub 8}P{sub 4}Cu{sub 1} alloy, and this tendency was reproduced by the analysis with commercial software, Thermo-Calc, with database for Fe-based alloys, TCFE7 for Gibbs free energy (G) assessments. The calculations exhibit that a volume fraction (V{sub f}) of α-Fe tends to increase from 0.56 for the Fe{sub 85}B{sub 15} to 0.75 for the Fe{sub 85}Si{sub 2}B{sub 8}P{sub 4}Cu{sub 1} alloy. The computational analysis of the alloys for G of α-Fe and amorphous phases (G{sub α-Fe} and G{sub amor}) shows that a relationship G{sub α-Fe} ∼ G{sub amor} holds for the Fe{sub 85}Si{sub 2}B{sub 12}Cu{sub 1}, whereas G{sub α-Fe} < G{sub amor} for the Fe{sub 85}Si{sub 2}B{sub 8}P{sub 4}Cu{sub 1} alloy at T{sub x1} and that an extremely high V{sub f} = 0.75 was achieved for the Fe{sub 85}Si{sub 2}B{sub 8}P{sub 4}Cu{sub 1} alloy by including 2.8 at. % Si and 4.5 at. % P into α-Fe. These computational results indicate that the Fe{sub 85}Si{sub 2}B{sub 8}P{sub 4}Cu{sub 1} alloy barely forms amorphous phase, which, in turn, leads to high V{sub f} and resultant high B{sub s}.« less

K[AsW{sub 2}O{sub 9}], the first member of the arsenate–tungsten bronze family: Synthesis, structure, spectroscopic and non-linear optical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alekseev, Evgeny V., E-mail: e.alekseev@fz-juelich.de; Institut für Kristallographie, RWTH Aachen, Jägerstraße 17–19 D-52066 Aachen; Felbinger, Olivier

K[AsW{sub 2}O{sub 9}], prepared by high-temperature solid-state reaction, is the first member of the arsenate–tungsten bronze family. The structure of K[AsW{sub 2}O{sub 9}] is based on a 3-dimensional (3D) oxotungstate–arsenate framework with the non-centrosymmetric P2{sub 1}2{sub 1}2{sub 1} space group, a=4.9747(3) Å, b=9.1780(8) Å, c=16.681(2) Å. The material was characterized using X-ray diffraction, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Raman and infrared (IR) spectroscopic techniques. The results of DSC demonstrate that this phase is stable up to 1076 K. Second harmonic generation (SHG) measurements performed on a powder sample demonstrate noticeable (0.1 of LiIO{sub 3}) non-linear optical (NLO)more » activity. - Graphical abstract: K[AsW{sub 2}O{sub 9}], the first member of arsenate–tungsten bronze family exhibit new three dimensional structure type, significant thermal stability and NLO properties. Highlights: • K[AsW{sub 2}O{sub 9}], the first member of the arsenate–tungsten bronze family was synthesized with solid state reaction technique. • Structure of this phase was investigated with X-ray diffraction, IR and Raman spectroscopy and electron microscopy. • Thermal stability of the phase was determinate with DSC techniques. • NLO properties were investigated.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanctis, Daniele de; Rêgo, Ana T.; Marçal, David

The sorbitol operon regulator from K. pneumoniae has been overexpressed in E. coli, purified and crystallized. Diffraction data were collected to 3.2 Å. The sorbitol operon regulator (SorC) regulates the metabolism of l-sorbose in Klebsiella pneumonia. SorC was overexpressed in Escherichia coli and purified, and crystals were obtained of a tetrameric form. A single crystal showed X-ray diffraction to 3.20 Å. The crystal belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 91.6, b = 113.3, c = 184.1 Å. Analysis of the molecular-replacement solution indicates the presence of four SorC molecules in the asymmetric unit.

[La(UO{sub 2})V{sub 2}O{sub 7}][(UO{sub 2})(VO{sub 4})] the first lanthanum uranyl-vanadate with structure built from two types of sheets based upon the uranophane anion-topology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mer, A.; Obbade, S.; Rivenet, M.

2012-01-15

The new lanthanum uranyl vanadate divanadate, [La(UO{sub 2})V{sub 2}O{sub 7}][(UO{sub 2})(VO{sub 4})] was obtained by reaction at 800 Degree-Sign C between lanthanum chloride, uranium oxide (U{sub 3}O{sub 8}) and vanadium oxide (V{sub 2}O{sub 5}) and the structure was determined from single-crystal X-ray diffraction data. This compound crystallizes in the orthorhombic system with space group P2{sub 1}2{sub 1}2{sub 1} and unit-cell parameters a=6.9470(2) A, b=7.0934(2) A, c=25.7464(6) A, V=1268.73(5) A{sup 3}, Z=4. A full matrix least-squares refinement yielded R{sub 1}=0.0219 for 5493 independent reflections. The crystal structure is characterized by the stacking of uranophane-type sheets {sup 2}{sub {infinity}}[(UO{sub 2})(VO{sub 4})]{sup -}more » and double layers {sup 2}{sub {infinity}}[La(UO{sub 2})(V{sub 2}O{sub 7})]{sup +} connected through La-O bonds involving the uranyl oxygen of the uranyl-vanadate sheets. The double layers result from the connection of two {sup 2}{sub {infinity}}[La(UO{sub 2})(VO{sub 4}){sub 2}]{sup -} sheets derived from the uranophane anion-topology by replacing half of the uranyl ions by lanthanum atoms and connected through the formation of divanadate entities. - Graphical abstract: A view of the three-dimensional structure of [La(UO{sub 2})V{sub 2}O{sub 7}][(UO{sub 2})(VO{sub 4})]. Highlights: Black-Right-Pointing-Pointer New lanthanum uranyl vanadate divanadate has been synthesized. Black-Right-Pointing-Pointer Structure was determined from single-crystal X-ray diffraction data. Black-Right-Pointing-Pointer Structure is characterized by uranophane-type sheets and double layers {sup 2}{sub {infinity}}[La(UO{sub 2})(V{sub 2}O{sub 7})]{sup +}.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, H.K.; Science Center for Phase Diagram and Materials Design and Manufacture, Central South University, Changsha, Hunan 410083; Cai, G.M., E-mail: caigemei@csu.edu.cn

Two novel borate compounds MgInBO{sub 4} and MgIn{sub 7/8}B{sub 7/8}O{sub 29/8}, have been synthesized via solid-state reactions, and their crystal structures have been solved and refined from powder X-ray diffraction data. The compound MgInBO{sub 4}, which was obtained at 1190 °C, belongs to the warwickite family. It crystallizes in the Pnma space group (no. 62) with a=9.5443(1) Å, b=3.2771(1) Å, c=9.5228(1) Å, and Z=4. The fundamental building units are liner –Mg(In)O{sub 6}–[In(Mg)]{sub 2}O{sub 10}–Mg(In)O{sub 6}– chains and isolated BO{sub 3} triangles. The low-temperature phase, MgIn{sub 7/8}B{sub 7/8}O{sub 29/8}, whose crystal structure is solved ab initio by the charge-flipping method withmore » standard chemical formula MgInBO{sub 4}, was prepared at 1080 °C. It crystallizes in the P12{sub 1}/n1 space group (no. 14) with a=17.0976(1) Å, b=3.2504(1) Å, c=5.3387(1) Å, β=96.0829(3)°, and Z=4. The structure of MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} contains [In(2)/Mg(2)]{sub 2}O{sub 10} groups, –MgO{sub 6}–InO{sub 6}– infinite ribbons and isolated BO{sub 3} triangles. The experiments and the differential thermal analysis (DTA) show the decompositions of MgInBO{sub 4} and MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} happen at about 1220 °C and 1180 °C, respectively. The comparative crystal chemistry from MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} to MgInBO{sub 4} has been discussed. Infrared spectra and UV–vis diffuse reflectance spectra of MgInBO{sub 4} and MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} were measured. - Graphical abstract: The structural transformation from the monoclinic MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} (P12{sub 1}/n1) to the orthorhombic MgInBO{sub 4} (Pnma). - Highlights: • Two novel borate compounds MgInBO{sub 4} and MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} have been synthesized via solid-state reactions for the first time. • The crystal structures of MgInBO{sub 4} and MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} have been solved and refined from powder X-ray diffraction data. • The possible crystal chemical analysis from MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} to MgInBO{sub 4} is discussed. • Infrared spectra and UV–vis diffuse reflectance spectra of MgInBO{sub 4} and MgIn{sub 7/8}B{sub 7/8}O{sub 29/8} have been measured.« less

Purification, crystallization and preliminary X-ray diffraction analysis of a soluble variant of the monoglyceride lipase Yju3p from the yeast Saccharomyces cerevisiae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rengachari, Srinivasan; Aschauer, Philipp; Sturm, Christian

A soluble variant of the monoglyceride lipase Yju3p was successfully expressed, purified and crystallized. Diffraction data were collected to 2.4 Å resolution. The protein Yju3p is the orthologue of monoglyceride lipases in the yeast Saccharomyces cerevisiae. A soluble variant of this lipase termed s-Yju3p (38.3 kDa) was generated and purified to homogeneity by affinity and size-exclusion chromatography. s-Yju3p was crystallized in a vapour-diffusion setup at 293 K and a complete data set was collected to 2.4 Å resolution. The crystal form was orthorhombic (space group P2{sub 1}2{sub 1}2{sub 1}), with unit-cell parameters a = 77.2, b = 108.6, c =more » 167.7 Å. The asymmetric unit contained four molecules with a solvent content of 46.4%.« less

Thermoelectric and mechanical properties on misch metal filled p-type skutterudites Mm{sub 0.9}Fe{sub 4−x}Co{sub x}Sb{sub 12}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dahal, Tulashi; Jie, Qing; Dahal, Keshab

2015-02-07

Most of the recent work focused on improving the dimensionless figure-of-merit, ZT, of p-type skutterudites uses one or two fillers to tune the electrical and thermal properties. Considering the fact that the different fillers with varying atomic mass and ionic radii can vibrate with different amplitudes to scatter phonons of different mean free paths, we synthesized misch metal filled p-type skutterudites Mm{sub 0.9}Fe{sub 4−x}Co{sub x}Sb{sub 12} (where Mm is La{sub 0.25}Ce{sub 0.5}Pr{sub 0.05}Nd{sub 0.15}Fe{sub 0.03}, called misch metal). The samples were synthesized by hot pressing nano-powder made by ball milling the annealed ingot of Mm{sub 0.9}Fe{sub 4−x}Co{sub x}Sb{sub 12} withmore » varying concentration of cobalt, x. By tuning the Fe/Co ratio, we achieved a thermal conductivity of ∼2 W m{sup −1} K{sup −1} at room temperature and ∼2.3 W m{sup −1} K{sup −1} at about 530 °C and a power factor of ∼30 μW cm{sup −1} K{sup −2} at about 425 °C in Mm{sub 0.9}Fe{sub 3.1}Co{sub 0.9}Sb{sub 12}, leading to a peak ZT ∼1.1 at about 425 °C. The nano-indentation experiment reveals that hardness and elastic modulus of the material is about 4.2 GPa and 116 GPa, respectively.« less

One Step Synthesis of a PerchlorinatedCyclohexasilane from Trichlorosilane: A Route to New Materials for Flexible Electronics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Philip Boudjouk

2010-03-27

The serendipitous discovery of tetradecachlorocyclohexasilane dianion 1 was recently reported by our group at NDSU. The dianion is isolated from a mixture of an amine template (pentaethyldiethylenetriamine, pedeta) and HSiCl{sub 3} as insoluble colorless crystals that are easily reduced to give cyclohexasilane (Si{sub 6}H{sub 12}) in high yields and purity. While the product Si{sub 6}H{sub 12} has been shown to be useful as a liquid silane precursor to a-Si:H rectifying diodes and field effect transistors, these initial studies show a non-uniform dopant distributions. The need for a homogeneous dopant has led our group to further develop the chemistry of cyclohexasilane.more » Toward that end, we have focused on the design of molecules that contain a single dopant moiety bound to one or more Si{sub 6} ring(s). New Si{sub 6}H{sub 11}E compounds (where E is an n-type or p-type dopant) are being investigated (eqs. 2, 3) and initial results will be reported including the isolation of chlorocyclohexasilane, Si{sub 6}H{sub 11}Cl. In addition, several different triamine ligand templates to for Si{sub 6}Cl{sub 14}{sup 2-} salts were investigated toward optimizing the yield and ease of isolation for both the salt and the product liquid silane. Cyclohexasilane (Si{sub 6}H{sub 12})-based inks have been used as liquid precursor to silicon-containing electronic materials. Spin-coating of Si{sub 6}H{sub 12}-based inks with subsequent UV light and/or thermal treatment yielded amorphous silicon (a-Si:H) films. Initial results demonstrated the formation of n-type and p-type a-Si that were used in heterojunction structures (i.e., thin a-Si films on heavily-doped Si wafer substrates). While present ink chemistries produce a-Si:H with a high resistivity (i.e., > 10{sup 6} {Omega}.cm), efforts are under development to address this limitation. Additionally, a new printing approach (i.e., collimated aerosol beam direct write, CAB-DW) was developed that allows the deposition of silane-based features with linewidths <10 {micro}m. Assuming silicon-based materials with good electrical properties will be developed, there may be significant cost advantages associated with the ability to controllably deposit the semiconductor in a metered fashion.« less

The crystal structure of the monohydrate R{sub 2}Mo{sub 6}O{sub 21}.H{sub 2}O (R=Pr, Nd, Sm, and Eu): a layer structure containing disordered [Mo{sub 2}O{sub 7}]{sup 2-} groups

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naruke, Haruo; Yamase, Toshihiro

2005-03-15

Although R{sub 2}O{sub 3}:MoO{sub 3}=1:6 (R=rare earth) compounds are known in the R{sub 2}O{sub 3}-MoO{sub 3} phase diagrams since a long time, no structural characterization has been achieved because a conventional solid-state reaction yields powder samples. We obtained single crystals of R{sub 2}Mo{sub 6}O{sub 21}.H{sub 2}O (R=Pr, Nd, Sm, and Eu) by thermal decomposition of [R{sub 2}(H{sub 2}O){sub 12}Mo{sub 8}O{sub 27}].nH{sub 2}O at around 685-715{sup o}C for 2h, and determined their crystal structures. The simulated XRD patterns of R{sub 2}Mo{sub 6}O{sub 21}.H{sub 2}O were consistent with those of previously reported R{sub 2}O{sub 3}:MoO{sub 3}=1:6 compounds. All R{sub 2}Mo{sub 6}O{sub 21}.H{submore » 2}O compounds crystallize isostructurally in tetragonal, P4/ncc (No. 130), a=8.9962(5), 8.9689(6), 8.9207(4), and 8.875(2)A; c=26.521(2), 26.519(2), 26.304(2), and 26.15(1)A; Z=4; R{sub 1}=0.026, 0.024, 0.024, and 0.021, for R=Pr, Nd, Sm, and Eu, respectively. The crystal structure of R{sub 2}Mo{sub 6}O{sub 21}.H{sub 2}O consists of two [Mo{sub 2}O{sub 7}]{sup 2-}-containing layers (A and B layers) and two interstitial R(1){sup 3+} and R(2){sup 3+} cations. Each [Mo{sub 2}O{sub 7}]{sup 2-} group is composed of two corner-sharing [MoO{sub 4}] tetrahedra. The [Mo{sub 2}O{sub 7}]{sup 2-} in the B layer exhibits a disorder to form a pseudo-[Mo{sub 4}O{sub 9}] group, in which four Mo and four O sites are half occupied. R(1){sup 3+} achieves 8-fold coordination by O{sup 2-} to form a [R(1)O{sub 8}] square antiprism, while R(2){sup 3+} achieves 9-fold coordination by O{sup 2-} and H{sub 2}O to form a [R(2)(H{sub 2}O)O{sub 8}] monocapped square antiprism. The disorder of the [Mo{sub 2}O{sub 7}]{sup 2-} group in the B layer induces a large displacement of the O atoms in another [Mo{sub 2}O{sub 7}]{sup 2-} group (in the A layer) and in the [R(1)O{sub 8}] and [R(2)(H{sub 2}O)O{sub 8}] polyhedra. A remarkable broadening of the photoluminescence spectrum of Eu{sub 2}Mo{sub 6}O{sub 21}.H{sub 2}O supported the large displacement of O ligands coordinating Eu(1) and Eu(2)« less

Full-dimensional, high-level ab initio potential energy surfaces for H{sub 2}(H{sub 2}O) and H{sub 2}(H{sub 2}O){sub 2} with application to hydrogen clathrate hydrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Homayoon, Zahra; Conte, Riccardo; Qu, Chen

2015-08-28

New, full-dimensional potential energy surfaces (PESs), obtained using precise least-squares fitting of high-level electronic energy databases, are reported for intrinsic H{sub 2}(H{sub 2}O) two-body and H{sub 2}(H{sub 2}O){sub 2} three-body potentials. The database for H{sub 2}(H{sub 2}O) consists of approximately 44 000 energies at the coupled cluster singles and doubles plus perturbative triples (CCSD(T))-F12a/haQZ (aug-cc-pVQZ for O and cc-pVQZ for H) level of theory, while the database for the three-body interaction consists of more than 36 000 energies at the CCSD(T)-F12a/haTZ (aug-cc-pVTZ for O, cc-pVTZ for H) level of theory. Two precise potentials are based on the invariant-polynomial technique and are comparedmore » to computationally faster ones obtained via “purified” symmetrization. All fits use reduced permutational symmetry appropriate for these non-covalent interactions. These intrinsic potentials are employed together with existing ones for H{sub 2}, H{sub 2}O, and (H{sub 2}O){sub 2}, to obtain full PESs for H{sub 2}(H{sub 2}O) and H{sub 2}(H{sub 2}O){sub 2}. Properties of these full PESs are presented, including a diffusion Monte Carlo calculation of the zero-point energy and wavefunction, and dissociation energy of the H{sub 2}(H{sub 2}O) dimer. These PESs together with an existing one for water clusters are used in a many-body representation of the PES of hydrogen clathrate hydrates, illustrated for H{sub 2}@(H{sub 2}O){sub 20}. An analysis of this hydrate is presented, including the electronic dissociation energy to remove H{sub 2} from the calculated equilibrium structure.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turner, Andrew M.; Abplanalp, Matthew J.; Kaiser, Ralf I.

Phosphine, which has now been confirmed around the carbon-rich star IRC+10216, provides the first example of a phosphorus-containing single bond in interstellar or circumstellar media. While four compounds containing both phosphorus and carbon have been discovered, none contain a carbon–phosphorus single bond. Here, we show that this moiety is plausible from the reaction of phosphine with methane in electron-irradiated interstellar ice analogues. Fractional sublimation allows for detection of individual products at distinct temperatures using reflectron time-of-flight mass spectrometry (ReTOF) coupled with vacuum ultraviolet photoionization. This method produced phosphanes and methylphosphanes as large as P{sub 8}H{sub 10} and CH{sub 3}P{sub 8}H{submore » 9}, which demonstrates that a phosphorus–carbon bond can readily form and that methylphosphanes sublime at 12–17 K higher temperatures than the non-organic phosphanes. Also, irradiated ices of phosphine with deuterated-methane untangle the reaction pathways through which these methylphosphanes were formed and identified radical recombination to be preferred over carbene/phosphinidene insertion reactions. In addition, these ReTOF results confirm that CH{sub 3}PH{sub 2} and CH{sub 6}P{sub 2} can form via insertion of carbene and phosphinidene and that the methylenediphosphine (PH{sub 2}CH{sub 2}PH{sub 2}) isomer forms in the ices, although methylphosphine (CH{sub 3}P{sub 2}H{sub 3}) is likely the more abundant isomer and that phosphanes and organophosphanes preferentially fragment via the loss of a phosphino group when photoionized. While the formation of methylphosphine is overall endoergic, the intermediates produced by interactions with energetic electrons proceed toward methylphosphine favorably and barrierlessly and provide plausible mechanisms toward hitherto unidentified interstellar compounds.« less

Rosiglitazone attenuates NF-{kappa}B-dependent ICAM-1 and TNF-{alpha} production caused by homocysteine via inhibiting ERK{sub 1/2}/p38MAPK activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bai, Yong-Ping; Liu, Yu-Hui; Chen, Jia

2007-08-17

Previous studies demonstrated an important interaction between nuclear factor-kappaB (NF-{kappa}B) activation and homocysteine (Hcy)-induced cytokines expression in endothelial cells and vascular smooth muscle cells. However, the underlying mechanism remains illusive. In this study, we investigated the effects of Hcy on NF-{kappa}B-mediated sICAM-1, TNF-{alpha} production and the possible involvement of ERK{sub 1/2}/p38MAPK pathway. The effects of rosiglitazone intervention were also examined. Our results show that Hcy increased the levels of sICAM-1 and TNF-{alpha} in cultured human umbilical vein endothelial cells (HUVECs) in a time- and concentration-dependent manner. This effect was significantly depressed by rosiglitazone and different inhibitors (PDTC, NF-{kappa}B inhibitor; PD98059,more » MEK inhibitor; SB203580, p38MAPK specific inhibitor; and staurosporine, PKC inhibitor). Next, we investigated the effect of Hcy on ERK{sub 1/2}/p38MAPK pathway and NF-{kappa}B activity in HUVECs. The results show that Hcy activated both ERK{sub 1/2}/p38MAPK pathway and NF-{kappa}B-DNA-binding activity. These effects were markedly inhibited by rosiglitazone as well as other inhibitors (SB203580, PD98059, and PDTC). Further, the pretreatment of staurosporine abrogated ERK{sub 1/2}/p38MAPK phosphorylation, suggesting that Hcy-induced ERK{sub 1/2}/p38MAPK activation is associated with PKC activity. Our results provide evidence that Hcy-induced NF-{kappa}B activation was mediated by activation of ERK{sub 1/2}/p38MAPK pathway involving PKC activity. Rosiglitazone reduces the NF-{kappa}B-mediated sICAM-1 and TNF-{alpha} production induced by Hcy via inhibition of ERK{sub 1/2}/p38MAPK pa0011thw.« less

ALMA imaging of gas and dust in a galaxy protocluster at redshift 5.3: [C II] emission in 'typical' galaxies and dusty starbursts ≈1 billion years after the big bang

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riechers, Dominik A.; Carilli, Christopher L.; Capak, Peter L.

2014-12-01

We report interferometric imaging of [C II]({sup 2} P {sub 3/2}→{sup 2} P {sub 1/2}) and OH({sup 2}Π{sub 1/2} J = 3/2→1/2) emission toward the center of the galaxy protocluster associated with the z = 5.3 submillimeter galaxy (SMG) AzTEC-3, using the Atacama Large (sub)Millimeter Array (ALMA). We detect strong [C II], OH, and rest-frame 157.7 μm continuum emission toward the SMG. The [C II]({sup 2} P {sub 3/2}→{sup 2} P {sub 1/2}) emission is distributed over a scale of 3.9 kpc, implying a dynamical mass of 9.7 × 10{sup 10} M {sub ☉}, and a star formation rate (SFR)more » surface density of Σ{sub SFR} = 530 M {sub ☉} yr{sup –1} kpc{sup –2}. This suggests that AzTEC-3 forms stars at Σ{sub SFR} approaching the Eddington limit for radiation pressure supported disks. We find that the OH emission is slightly blueshifted relative to the [C II] line, which may indicate a molecular outflow associated with the peak phase of the starburst. We also detect and dynamically resolve [C II]({sup 2} P {sub 3/2}→{sup 2} P {sub 1/2}) emission over a scale of 7.5 kpc toward a triplet of Lyman-break galaxies with moderate UV-based SFRs in the protocluster at ∼95 kpc projected distance from the SMG. These galaxies are not detected in the continuum, suggesting far-infrared SFRs of <18-54 M {sub ☉} yr{sup –1}, consistent with a UV-based estimate of 22 M {sub ☉} yr{sup –1}. The spectral energy distribution of these galaxies is inconsistent with nearby spiral and starburst galaxies, but resembles those of dwarf galaxies. This is consistent with expectations for young starbursts without significant older stellar populations. This suggests that these galaxies are significantly metal-enriched, but not heavily dust-obscured, 'normal' star-forming galaxies at z > 5, showing that ALMA can detect the interstellar medium in 'typical' galaxies in the very early universe.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kahlenberg, Volker; Konzett, Juergen; Kaindl, Reinhard

High-pressure synthesis experiments in the system Na{sub 2}O-Y{sub 2}O{sub 3}-SiO{sub 2} revealed the existence of a previously unknown polymorph of NaYSi{sub 2}O{sub 6} or Na{sub 3}Y{sub 3}[Si{sub 3}O{sub 9}]{sub 2} which was quenched from 3.0 GPa and 1000 deg. C. Structural investigations on this modification have been performed using single-crystal X-ray diffraction data collected at ambient conditions. Furthermore, unpolarized micro-Raman spectra have been obtained from single-crystal material. The high-P modification of NaYSi{sub 2}O{sub 6} crystallizes in the centrosymmetric space group C2/c with 12 formula units per cell (a=8.2131(9) A, b=10.3983(14) A, c=17.6542(21) A, {beta}=100.804(9){sup o}, V=1481.0(3) A{sup 3}, R(|F|)=0.033 formore » 1142 independent observed reflections) and belongs to the group of cyclo-silicates. Basic building units are isolated three-membered [Si{sub 3}O{sub 9}] rings located in layers parallel to (010). Within a single layer the rings are concentrated in strings parallel to [100]. The sequence of directedness of up (U) or down (D) pointing tetrahedra of a single ring is UUU or DDD, respectively. Stacking of the layers parallel to b results in the formation of a three-dimensional structure in which yttrium and sodium cations are incorporated for charge compensation. In more detail, four non-tetrahedral cation positions can be differentiated which are coordinated by 6 and 8 oxygen ligands. Refinements of the site occupancies did not reveal any indication for mixed Na-Y populations on these positions. Finally, several geometrical parameters of rings occurring in cyclo-trisilicate structures have been compiled and are discussed. - Graphical abstract: Projection of the whole structure of high-P NaYSi{sub 2}O{sub 6} parallel to [100].« less

(Pt{sub 1–x}Cu{sub x}){sub 3}Cu{sub 2}B and Pt{sub 9}Cu{sub 3}B{sub 5}, the first examples of copper platinum borides. Observation of superconductivity in a novel boron filled β-Mn-type compound

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salamakha, Leonid P.; Sologub, Oksana, E-mail: oksana.sologub@univie.ac.at; Stöger, Berthold

New ternary copper platinum borides have been synthesized by arc melting of pure elements followed by annealing at 600 °C. The structures have been studied by X-ray single crystal and powder diffraction. (Pt{sub 1−x}Cu{sub x}){sub 3}Cu{sub 2}B (x=0.33) forms a B-filled β-Mn-type structure (space group P4{sub 1}32; a=0.6671(1) nm). Cu atoms are distributed preferentially on the 8c atom sites, whereas the 12d site is randomly occupied by Pt and Cu atoms (0.670(4) Pt±0.330(4) Cu). Boron is located in octahedral voids of the parent β-Mn-type structure. Pt{sub 9}Cu{sub 3}B{sub 5} (space group P-62m; a=0.9048(3) nm, c=0.2908(1) nm) adopts the Pt{sub 9}Zn{submore » 3}B{sub 5–δ}-type structure. It has a columnar architecture along the short translation vector exhibiting three kinds of [Pt{sub 6}] trigonal prism columns (boron filled, boron semi-filled and empty) and Pt channels with a pentagonal cross section filled with Cu atoms. The striking structural feature is a [Pt{sub 6}] cluster in form of an empty trigonal prism at the origin of the unit cell, which is surrounded by coupled [BPt{sub 6}] and [Pt{sub 6}] trigonal prisms, rotated perpendicularly to the central one. There is no B–B contact as well as Cu–B contact in the structure. The relationships of Pt{sub 9}Cu{sub 3}B{sub 5} structure with the structure of Ti{sub 1+x}Os{sub 2−x}RuB{sub 2} as well as with the structure families of metal sulfides and aluminides have been elucidated. (Pt{sub 1–x}Cu{sub x}){sub 3}Cu{sub 2}B (x=0.3) (B-filled β-Mn-type structure) is a bulk superconductor with a transition temperature of about 2.06 K and an upper critical field μ{sub 0}H{sub C2}(0){sup WHH} of 1.2 T, whereas no superconducting transition has been observed up to 0.3 K in Pt{sub 9}Cu{sub 3}B{sub 5} (Pt{sub 9}Zn{sub 3}B{sub 5–δ}-type structure) from electrical resistivity measurements. - Highlights: • First two copper platinum borides, (Pt{sub 0.67}Cu{sub 0.33}){sub 3}Cu{sub 2}B and Pt{sub 9}Cu{sub 3}B{sub 5} were obtained. • (Pt{sub 0.67}Cu{sub 0.33}){sub 3}Cu{sub 2}B forms a B-filled β-Mn-type structure. • Pt{sub 9}Cu{sub 3}B{sub 5} adopts a Pt{sub 9}Zn{sub 3}B{sub 5–δ}-type structure. • Boron atoms exhibit octahedral and trigonal prismatic coordination. • (Pt{sub 1–x}Cu{sub x})3Cu{sub 2}B (x=0.3) is a bulk superconductor with T{sub c} 2.06 K.« less

Expression, purification, crystallization and preliminary crystallographic study of isolated modules of the mouse coactivator-associated arginine methyltransferase 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Troffer-Charlier, Nathalie; Cura, Vincent; Hassenboehler, Pierre

2007-04-01

Isolated modules of mouse coactivator-associated arginine methyltransferase 1 encompassing the protein arginine N-methyltransferase catalytic domain have been overexpressed, purified and crystallized. X-ray diffraction data have been collected and have enabled determination of the structures by multiple isomorphous replacement using anomalous scattering. Coactivator-associated arginine methyltransferase 1 (CARM1) plays a crucial role in gene expression as a coactivator of several nuclear hormone receptors and also of non-nuclear receptor systems. Its recruitment by the transcriptional machinery induces protein methylation, leading to chromatin remodelling and gene activation. CARM1{sub 28–507} and two structural states of CARM1{sub 140–480} were expressed, purified and crystallized. Crystals of CARM1{submore » 28–507} belong to space group P6{sub 2}22, with unit-cell parameters a = b = 136.0, c = 125.3 Å; they diffract to beyond 2.5 Å resolution using synchrotron radiation and contain one monomer in the asymmetric unit. The structure of CARM1{sub 28–507} was solved by multiple isomorphous replacement and anomalous scattering methods. Crystals of apo CARM1{sub 140–480} belong to space group I222, with unit-cell parameters a = 74.6, b = 99.0, c = 207.4 Å; they diffract to beyond 2.7 Å resolution and contain two monomers in the asymmetric unit. Crystals of CARM1{sub 140–480} in complex with S-adenosyl-l-homocysteine belong to space P2{sub 1}2{sub 1}2, with unit-cell parameters a = 74.6, b = 98.65, c = 206.08 Å; they diffract to beyond 2.6 Å resolution and contain four monomers in the asymmetric unit. The structures of apo and holo CARM1{sub 140–480} were solved by molecular-replacement techniques from the structure of CARM1{sub 28–507}.« less

Stable trifluorostyrene containing compounds grafted to base polymers, and their use as polymer electrolyte membranes

DOEpatents

Yang, Zhen-Yu; Roelofs, Mark Gerrit

2010-11-09

A fluorinated ion exchange polymer prepared by grafting at least one grafting monomer on to at least one base polymer, wherein the grafting monomer comprises structure 1a or 1b: wherein Z comprises S, SO.sub.2, or POR wherein R comprises a linear or branched perfluoroalkyl group of 1 to 14 carbon atoms optionally containing oxygen or chlorine, an alkyl group of 1 to 8 carbon atoms, an aryl group of 6 to 12 carbon atoms or a substituted aryl group of 6 to 12 carbon atoms; RF comprises a linear or branched perfluoroalkene group of 1 to 20 carbon atoms, optionally containing oxygen or chlorine; Q is chosen from F, --OM, NH.sub.2, --N(M)SO.sub.2R.sup.2.sub.F, and C(M)(SO.sub.2R.sup.2.sub.F).sub.2, wherein M comprises H, an alkali cation, or ammonium; R.sup.2.sub.F groups comprises alkyl of 1 to 14 carbon atoms which may optionally include ether oxygens or aryl of 6 to 12 carbon atoms where the alkyl or aryl groups may be perfluorinated or partially fluorinated; and n is 1 or 2 for 1a, and n is 1, 2, or 3 for 1b. These ion exchange polymers are useful in preparing catalyst coated membranes and membrane electrode assemblies used in fuel cells.

Stable trifluorostyrene containing compounds grafted to base polymers, and their use as polymer electrolyte membranes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Zhen-Yu; Roelofs, Mark Gerrit

2010-11-09

A fluorinated ion exchange polymer prepared by grafting at least one grafting monomer on to at least one base polymer, wherein the grafting monomer comprises structure 1a or 1b: wherein Z comprises S, SO.sub.2, or POR wherein R comprises a linear or branched perfluoroalkyl group of 1 to 14 carbon atoms optionally containing oxygen or chlorine, an alkyl group of 1 to 8 carbon atoms, an aryl group of 6 to 12 carbon atoms or a substituted aryl group of 6 to 12 carbon atoms; RF comprises a linear or branched perfluoroalkene group of 1 to 20 carbon atoms, optionallymore » containing oxygen or chlorine; Q is chosen from F, --OM, NH.sub.2, --N(M)SO.sub.2R.sup.2.sub.F, and C(M)(SO.sub.2R.sup.2.sub.F).sub.2, wherein M comprises H, an alkali cation, or ammonium; R.sup.2.sub.F groups comprises alkyl of 1 to 14 carbon atoms which may optionally include ether oxygens or aryl of 6 to 12 carbon atoms where the alkyl or aryl groups may be perfluorinated or partially fluorinated; and n is 1 or 2 for 1a, and n is 1, 2, or 3 for 1b. These ion exchange polymers are useful in preparing catalyst coated membranes and membrane electrode assemblies used in fuel cells.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morozkin, A.V., E-mail: morozkin@general.chem.msu.r; Mozharivskyj, Yu.; SvitlyK, V.

The magnetic ordering of the Fe{sub 2}P-type Tb{sub 6}FeTe{sub 2}, Tb{sub 6}CoTe{sub 2} Tb{sub 6}NiTe{sub 2} and Er{sub 6}FeTe{sub 2} phases (space group P6-bar 2m) has been investigated through magnetization measurement and neutron powder diffraction. Tb{sub 6}FeTe{sub 2}, Tb{sub 6}CoTe{sub 2} and Tb{sub 6}NiTe{sub 2} demonstrate high-temperature ferromagnetic and low-temperature spin reorientation transitions, whereas Er{sub 6}FeTe{sub 2} shows antiferromagnetic transition, only. The Tb{sub 6}FeTe{sub 2} and Tb{sub 6}NiTe{sub 2} phases show same high-temperature collinear ferromagnetic structure, whereas Tb{sub 6}FeTe{sub 2} is the commensurate non-collinear ferromagnet and Tb{sub 6}NiTe{sub 2} is the canted ferromagnetic cone with K{sub 1}=[0, 0, {+-}3/10] andmore » K{sub 2}=[{+-}2/9, {+-}2/9, 0] wave vectors at 2 K. The magnetic structure of Er{sub 6}FeTe{sub 2} is a flat spiral with K{sub 1}=[0, 0, {+-}1/10] at 2 K. The magnetic entropy change for Tb{sub 6}NiTe{sub 2} is {Delta}S{sub m}=-4.86 J/kg K at 229 K for the field change {Delta}{mu}{sub 0}H=0-5 T. In addition, novel Fe{sub 2}P-type Gd{sub 6}FeTe{sub 2}, Zr{sub 6}FeTe{sub 2}, Hf{sub 6}FeTe{sub 2}, Dy{sub 6}NiTe{sub 2}, Zr{sub 6}NiTe{sub 2} and Hf{sub 6}NiTe{sub 2} phases have been obtained. -- Graphical abstract: The novel Fe{sub 2}P-type Tb{sub 6{l_brace}}Fe, Co, Te{r_brace}Te{sub 2} and Er{sub 6}FeTe{sub 2} phases (space group P6-bar 2m) show the complex magnetic ordering below 18-228 K. The magnetocaloric effect for Tb{sub 6}NiTe{sub 2} in terms of the isothermal entropy change, -{Delta}S{sub m}, has the maximum value of 4.86 J/kg K at 229 K for the 0-5 T field change.« less

Essential elucidation for preparation of supported nickel phosphide upon nickel phosphate precursor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Xuguang, E-mail: liuxuguang@qust.edu.cn; Xu, Lei; Zhang, Baoquan

2014-04-01

Preparation of supported nickel phosphide (Ni{sub 2}P) depends on nickel phosphate precursor, generally related to its chemical composition and supports. Study of this dependence is essential and meaningful for the preparation of supported Ni{sub 2}P with excellent catalytic activity. The chemical nature of nickel phosphate precursor is revealed by Raman and UV–vis spectra. It is found that initial P/Ni mole ratio ≥0.8 prohibits the Ni-O-Ni bridge bonding (i.e., nickel oxide). This chemical bonding will not result in Ni{sub 2}P structure, verified by XRD characterization results. The alumina (namely, γ-Al{sub 2}O{sub 3}, θ-Al{sub 2}O{sub 3}, or α-Al{sub 2}O{sub 3}) with distinctmore » physiochemical properties also results in diverse chemical nature of nickel phosphate, and then different nickel phosphides. The influence of alumina support on producing Ni{sub 2}P was explained by the theory of surface energy heterogeneity, calculated by the NLDFT method based on N{sub 2}-sorption isotherm. The uniform surface energy of α-Al{sub 2}O{sub 3} results only in the nickel phosphosate precursor and thus the Ni{sub 2}P phase. - Graphical abstract: Surface energy heterogeneity in alumina (namely α-Al{sub 2}O{sub 3}, θ-Al{sub 2}O{sub 3}, and γ-Al{sub 2}O{sub 3}) supported multi-oxidic precursors with different reducibilities and thus diverse nickel phosphides (i.e., Ni{sub 3}P, Ni{sub 12}P{sub 5}, Ni{sub 2}P). - Highlights: • Preparing pure Ni{sub 2}P. • Elucidating nickel phosphate precursor. • Associating with surface energy.« less

Direct observation of the ferroelectric polarization in the layered perovskite Bi{sub 4}Ti{sub 3}O{sub 12}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Urushihara, Daisuke; Asaka, Toru, E-mail: asaka.toru@nitech.ac.jp; Frontier Research Institute for Materials Science, Nagoya Institute of Technology, Nagoya 466-8555

We investigated the crystal structure and ferroelectric domains of Bi{sub 4}Ti{sub 3}O{sub 12} (BTO) by means of transmission electron microscopy (TEM) and single-crystal X-ray diffractometry. From the extinction rule, we determined that the space group in the ferroelectric phase of BTO is P1a1 rather than B2cb and B1a1 which have been proposed previously. We successfully refined the crystal structure based on the space group P1a1. The 180° and 90° ferroelectric domain structures were observed by the [001]-zone dark-field TEM imaging. In the 180° domain structure, we determined that one component of the polarization vector is parallel to the a-axis. Anmore » annular bright-field scanning transmission electron microscopy (ABF-STEM) was performed for the direct observation of the crystal structures. The ABF-STEM images displayed the contrasts with respect to every atomic position in spite of the highly distorted structure of BTO. We could evaluate the tilting and distortion of the [TiO{sub 6}] octahedra relatively. Therefore, we directly observed the ferroelectric displacements of Bi and Ti ions.« less

Methods of forming single source precursors, methods of forming polymeric single source precursors, and single source precursors formed by such methods

DOEpatents

Fox, Robert V.; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin; Margulieux, Kelsey R.; Holland, Andrew W.

2016-04-19

Methods of forming single source precursors (SSPs) include forming intermediate products having the empirical formula 1/2{L.sub.2N(.mu.-X).sub.2M'X.sub.2}.sub.2, and reacting MER with the intermediate products to form SSPs of the formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2, wherein L is a Lewis base, M is a Group IA atom, N is a Group IB atom, M' is a Group IIIB atom, each E is a Group VIB atom, each X is a Group VIIA atom or a nitrate group, and each R group is an alkyl, aryl, vinyl, (per)fluoro alkyl, (per)fluoro aryl, silane, or carbamato group. Methods of forming polymeric or copolymeric SSPs include reacting at least one of HE.sup.1R.sup.1E.sup.1H and MER with one or more substances having the empirical formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2 or L.sub.2N(.mu.-X).sub.2M'(X).sub.2 to form a polymeric or copolymeric SSP. New SSPs and intermediate products are formed by such methods.

Methods of forming single source precursors, methods of forming polymeric single source precursors, and single source precursors formed by such methods

DOEpatents

Fox, Robert V.; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin; Margulieux, Kelsey R.; Holland, Andrew W.

2014-09-09

Methods of forming single source precursors (SSPs) include forming intermediate products having the empirical formula 1/2{L.sub.2N(.mu.-X).sub.2M'X.sub.2}.sub.2, and reacting MER with the intermediate products to form SSPs of the formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2, wherein L is a Lewis base, M is a Group IA atom, N is a Group IB atom, M' is a Group IIIB atom, each E is a Group VIB atom, each X is a Group VIIA atom or a nitrate group, and each R group is an alkyl, aryl, vinyl, (per)fluoro alkyl, (per)fluoro aryl, silane, or carbamato group. Methods of forming polymeric or copolymeric SSPs include reacting at least one of HE.sup.1R.sup.1E.sup.1H and MER with one or more substances having the empirical formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2 or L.sub.2N(.mu.-X).sub.2M'(X).sub.2 to form a polymeric or copolymeric SSP. New SSPs and intermediate products are formed by such methods.

Comparative study of A-site order in the lead-free bismuth titanates M{sub 1/2}Bi{sub 1/2}TiO{sub 3} (M=Li, Na, K, Rb, Cs, Ag, Tl) from first-principles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gröting, Melanie, E-mail: groeting@mm.tu-darmstadt.de; Albe, Karsten, E-mail: albe@mm.tu-darmstadt.de

2014-05-01

We investigate the possibility of enhancing chemical order in the relaxor ferroelectric Na{sub 1/2}Bi{sub 1/2}TiO{sub 3} upon substitution of Na{sup +} by other monovalent cations M{sup +} using total energy calculations based on density functional theory. All chemically available monovalent cations M{sup +}, which are Li, Na, Ag, K, Tl, Rb and Cs, are considered and an analysis of the structurally relaxed structures in terms of symmetry-adapted distortion modes is given in order to quantify the chemically induced structural distortions. We demonstrate that the replacement of Na{sup +} by other monovalent cations can hardly alter the tendency of chemical ordermore » with respect to Na{sub 1/2}Bi{sub 1/2}TiO{sub 3}. Only Tl{sub 1/2}Bi{sub 1/2}TiO{sub 3} and Ag{sub 1/2}Bi{sub 1/2}TiO{sub 3} show enhanced tendency for chemical ordering. Both heavy metals behave similar to the light alkali metals in terms of structural relaxations and relative stabilities of the ordered configurations. Although a comparison of the Goldschmidt factors of components (M TiO{sub 3}){sup −} reveals for Tl a value above the upper stability limit for perovskites, the additional lone-pair effect of Tl{sup +} stabilizes the ordered structure. - Graphical abstract: Amplitudes of chemically induced distortion modes in different ordered perovskites M{sub 1/2}Bi{sub 1/2}TiO{sub 3} and visualisation of atomic displacements associated with distortion mode X{sup +}{sub 1} in the 001-ordered compounds Li{sub 1/2}Bi{sub 1/2}TiO{sub 3} and Cs{sub 1/2}Bi{sub 1/2}TiO{sub 3}. Due to a substantial size mismatch between bismuth (green) and caesium (dark blue), incorporation of the latter leads to enhanced displacements of oxygen atoms (red) and suppresses displacements of titanium (silver) as compared to lithium (light blue) or other smaller monovalent cations. - Highlights: • Lead-free A-site mixed bismuth titanates M{sub 1/2}Bi{sub 1/2}TiO{sub 3} are studied by first-principles calculations. • Investigation of chemical ordering tendency for M=Li, Na, K, Rb, Cs, Ag, and Tl. • Group theoretical analysis of different ordered structures. • Ag and Tl compounds are the most promising candidates for study of chemical order dependent ferroelectric properties.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zagidullin, M V; Azyazov, V N; Malyshev, M S

The kinetics of the processes occurring in an O{sub 2} – I{sub 2} – He – H{sub 2}O gas flow in which photodissociation of molecular iodine at a wavelength close to 500 nm and excitation of atomic iodine on the {sup 2}P{sub 1/2} – {sup 2}P{sub 3/2} transition by narrow-band radiation near 1315 nm are implemented successively has been analysed. It is shown that implementation of these processes allows one to form an oxygen – iodine medium with a high degree of dissociation of molecular iodine and a relative content of singlet oxygen O{sub 2}(a{sup 1}Δ) exceeding 10%. Having formedmore » a supersonic gas flow with a temperature ∼100 K from this medium, one can reach a small-signal gain of about 10{sup -2} cm{sup -1} on the {sup 2}P{sub 1/2} – {sup 2}P{sub 3/2} transition in iodine atoms. The specific power per unit flow cross section in the oxygen – iodine laser with this active medium may reach ∼100 W cm{sup -2}. (active media)« less

Crystallization and preliminary X-ray characterization of arylamine N-acetyltransferase C (BanatC) from Bacillus anthracis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pluvinage, Benjamin; Li de la Sierra-Gallay, Inés; Martins, Marta

2007-10-01

Bacillus anthracis arylamine N-acetyltransferase C (BanatC) is an enzyme that metabolizes the drug sulfamethoxazole. Crystals of the purified enzyme that diffract at 1.95 Å are reported. The arylamine N-acetyltransferase (NAT) enzymes are xenobiotic metabolizing enzymes that have been found in a large range of eukaryotes and prokaryotes. These enzymes catalyse the acetylation of arylamine drugs and/or pollutants. Recently, a Bacillus anthracis NAT isoform (BanatC) has been cloned and shown to acetylate the sulfonamide antimicrobial sulfamethoxazole (SMX). Subsequently, it was shown that BanatC contributes to the resistance of this bacterium to SMX. Here, the crystallization and the X-ray characterization of BanatCmore » (Y38F mutant) are reported. The crystals belong to the tetragonal space group P4{sub 1}2{sub 1}2 or P4{sub 3}2{sub 1}2, with unit-cell parameters a = b = 53.70, c = 172.40 Å, and diffract to 1.95 Å resolution on a synchrotron source.« less

Effect of Acute Exposure to Hypergravity (Gx vs. Gz) on Dynamic Cerebral Autoregulation

NASA Technical Reports Server (NTRS)

Serrador, Jorge M.; Wood, S. J.; Picot, P. A.; Stein, F.; Kassam, M. S.; Bondar, R. L.; Rupert, A. H.; Schlegel, T. T.

2001-01-01

We examined the effects of 30 min of exposure to either +3G(sub x) or +3G(sub z) centrifugation on cerebrovascular responses to 800 head-up tilt (HUT) in 14 healthy individuals. Both before and after +3G(sub x) or +3G(sub z) centrifugation, eye-level blood pressure (BP(sub eye)), end tidal CO2 (P(sub ET)CO2), mean cerebral flow velocity (CFV) in the middle cerebral artery (trans cranial Doppler ultrasound), cerebral vascular resistance (CVR) and dynamic cerebral autoregulatory gain (GAIN) were measured with subjects in the supine position and during subsequent 800 HUT for 30 min. Mean BP(sub eye) decreased with HUT in both the G(sub x) (n= 7) and G(sub z) (n=7) groups (P less than 0.00l), with the decrease being greater after centrifugation only in the G(sub z) group (P less than 0.05). P(sub ET)CO2 also decreased with HUT in both groups (P less than 0.0l), but the absolute level of decrease was unaffected by centrifugation. CFV decreased during HUT more significantly after than before centrifugation in both groups (P less than 0.02). However, these greater decreases were not associated with greater increases in CVR. In the supine position after compared to before centrifugation, GAIN increased in both groups (P less than 0.05, suggesting an autoregulatory deficit), with the change being correlated to a measure of otolith function (the linear vestibulo-ocular reflex) in the G(sub x) group (R=0.76, P less than 0.05) but not in the G(sub z) group (R=0.24, P=0.60). However, GAIN was subsequently restored to pre-centrifugation levels during post-centrifugation HUT (i.e., as BP(sub eye) decreased), suggesting that both types of centrifugation resulted in a leftward shift of the cerebral autoregulation curve. We speculate that this leftward shift may have been due to vestibular activation (especially during +G(sub x)) or potentially to an adaptation to reduced cerebral perfusion pressure during +G(sub z).

Synthesis, crystal structures and ionic conductivities of Bi{sub 14}P{sub 4}O{sub 31} and Bi{sub 50}V{sub 4}O{sub 85}. Two members of the series Bi{sub 18-4m}M{sub 4m}O{sub 27+4m} (M=P, V) related to the fluorite-type structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mauvy, F.; Launay, J.C.; Darriet, J.

2005-06-15

The two hitherto unknown compounds Bi{sub 14}P{sub 4}O{sub 31} and Bi{sub 50}V{sub 4}O{sub 85} were prepared by the direct solid-state reaction of Bi{sub 2}O{sub 3} and (NH{sub 4})H{sub 2}PO{sub 4} or V{sub 2}O{sub 5}, respectively. Bi{sub 14}P{sub 4}O{sub 31} crystallizes in a C-centred monoclinic symmetry (C2/c space group) with the unit-cell parameters: a=19.2745(2)A, b=11.3698(1)A, c=52.4082(2)A and {beta}=93.63(1){sup o} (Z=16). The symmetry of Bi{sub 50}V{sub 4}O{sub 85} is also monoclinic (I2/m space group) with lattice parameters of a=11.8123(3)A, b=11.7425(2)A, c=16.5396(2)A and {beta}=90.14(1){sup o} (Z=2). Both structures correspond to a fluorite-type superstructure where the Bi and P or V atoms are orderedmore » in the framework. An idealized structural model is proposed where the structures result of the stacking of mixed atomic layers of composition [Bi{sub 14}M{sub 4}O{sub 31}] and [Bi{sub 18}O{sub 27}] respectively. This new family can be formulated Bi{sub 18-4m}M{sub 4m}O{sub 27+4m} with M=P, V and where the parameter m (0=

Calcio-olivine {gamma}-Ca{sub 2}SiO{sub 4}: I. Rietveld refinement of the crystal structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gobechiya, E. R., E-mail: elgob@mail.ru; Yamnova, N. A.; Zadov, A. E.

2008-05-15

The structure of the natural mineral calcio-olivine ({gamma}-Ca{sub 2}SiO{sub 4}) found in skarn xenoliths in the region of the Lakargi Mountain (North Caucasus, Kabardino-Balkaria, Russia) is refined by the Rietveld method [a = 5.07389(7) A, b = 11.21128(14) A, c = 6.75340(9) A, V = 384.170(5) A{sup 3}, Z = 4, {rho}{sub calcd} = 2.98 g/cm{sup 3}, space group Pbnm]. The X-ray diffraction pattern of a powdered sample is recorded on a STOE STADI MP diffractometer [{lambda}CuK{sub {alpha}1}; Ge(111) primary monochromator; 6.00{sup o} < 2{theta} < 100.88{sup o}; step width, 2.5{sup o} in 2{theta}; number of reflections, 224]. All calculationsmore » are performed with the WYRIET (version 3.3) software package. The structural model is refined in the anisotropic approximation to R{sub p} = 6.44, R{sub wp} = 8.52, R{sub exp} = 5.85, R{sub B} = 4.98, R{sub F} = 6.90, and s = 1.46. It is shown that the sample under investigation is a mixture of several mineral phases, among which calcio-olivine (the natural analogue of the {gamma}-Ca{sub 2}SiO{sub 4} compound) (83%), hillebrandite (13%), and wadalite (4%) are dominant. Only the scale factors and the unit cell parameters are refined for hillebrandite Ca{sub 2}SiO{sub 3}(OH){sub 2} [a = 3.63472(16) A, b = 16.4140(10) A, c = 11.7914(8) A, space group Cmc2{sub 1}, Z = 6] and wadalite Ca{sub 6}Al{sub 5}Si{sub 2}O{sub 16}Cl{sub 3} (a = 12.0088 A, space group, I 4 bar 3d, Z = 4). The results of the structure refinement of the main component of the sample confirm that the mineral calcio-olivine is isostructural to the synthetic compound {gamma}-Ca{sub 2}SiO{sub 4}. The structure of this compound is formed by the heteropolyhedral framework composed of Ca octahedra joined together into olivine-like ribbons and isolated Si tetrahedra.« less

Synthesis Of Labeled Metabolites

DOEpatents

Martinez, Rodolfo A.; Silks, III, Louis A.; Unkefer, Clifford J.; Atcher, Robert

2004-03-23

The present invention is directed to labeled compounds, for example, isotopically enriched mustard gas metabolites including: [1,1',2,2'-.sup.13 C.sub.4 ]ethane, 1,1'-sulfonylbis[2-(methylthio); [1,1',2,2'-.sup.13 C.sub.4 ]ethane, 1-[[2-(methylsulfinyl)ethyl]sulfonyl]-2-(methylthio); [1,1',2,2'-.sup.13 C.sub.4 ]ethane, 1,1'-sulfonylbis[2-(methylsulfinyl)]; and, 2,2'-sulfinylbis([1,2-.sup.13 C.sub.2 ]ethanol of the general formula ##STR1## where Q.sup.1 is selected from the group consisting of sulfide (--S--), sulfone (--S(O)--), sulfoxide (--S(O.sub.2)--) and oxide (--O--), at least one C* is .sup.13 C, X is selected from the group consisting of hydrogen and deuterium, and Z is selected from the group consisting of hydroxide (--OH), and --Q.sup.2 --R where Q.sup.2 is selected from the group consisting of sulfide (--S--), sulfone(--S(O)--), sulfoxide (--S(O.sub.2)--) and oxide (--O--), and R is selected from the group consisting of hydrogen, a C.sub.1 to C.sub.4 lower alkyl, and amino acid moieties, with the proviso that when Z is a hydroxide and Q.sup.1 is a sulfide, then at least one X is deuterium.

Purification, crystallization and X-ray diffraction analysis of a novel ring-cleaving enzyme (BoxC{sub C}) from Burkholderia xenovorans LB400

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bains, Jasleen; Boulanger, Martin J., E-mail: mboulang@uvic.ca

2008-05-01

Preliminary X-ray diffraction studies of a novel ring-cleaving enzyme from B. xenovorans LB400 encoded by the benzoate-oxidation (box) pathway. The assimilation of aromatic compounds by microbial species requires specialized enzymes to cleave the thermodynamically stable ring. In the recently discovered benzoate-oxidation (box) pathway in Burkholderia xenovorans LB400, this is accomplished by a novel dihydrodiol lyase (BoxC{sub C}). Sequence analysis suggests that BoxC{sub C} is part of the crotonase superfamily but includes an additional uncharacterized region of approximately 115 residues that is predicted to mediate ring cleavage. Processing of X-ray diffraction data to 1.5 Å resolution revealed that BoxC{sub C} crystallizedmore » with two molecules in the asymmetric unit of the P2{sub 1}2{sub 1}2{sub 1} space group, with a solvent content of 47% and a Matthews coefficient of 2.32 Å{sup 3} Da{sup −1}. Selenomethionine BoxC{sub C} has been purified and crystals are currently being refined for anomalous dispersion studies.« less

Effect of p–d hybridization, structural distortion and cation electronegativity on electronic properties of ZnSnX{sub 2} (X=P, As, Sb) chalcopyrite semiconductors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, S.; Ganguli, B., E-mail: biplabg@nitrkl.ac.in

2013-04-15

Significant effects of p–d hybridization, structural distortion and cation-electro-negativity are found on band gap in ZnSnX{sub 2} (X=P, As, Sb). Our study suggests these compounds to be direct band gap semiconductors with band gaps of 1.23, 0.68 and 0.19 eV respectively. Lattice constants, tetragonal distortion (η), anion displacement, bond lengths and bulk moduli are calculated by Density Functional Theory based on Tight binding Linear Muffin-Tin orbital method. Our result of structural properties is in good agreement with the available experimental and other theoretical results. Calculated band gaps also agree well with the experimental works within LDA limitation. Unlike other semiconductorsmore » in the group II–IV–V{sub 2}, there is a reduction in the band gap of 0.22, 0.20 and 0.24 eV respectively in ZnSnX{sub 2} (X=P, As, Sb) due to p–d hybridization. Structural distortion decreases band gap by 0.20, 0.12 and 0.10 eV respectively. We find that cation electronegativity effect is responsible for increasing the band gap relative to their binary analogs GaInP{sub 2}, InGaAs{sub 2} and GaInSb{sub 2} respectively and increment are 0.13, 0.04 and 0.13 eV respectively. - Graphical abstract: One unit cell of ZnSnX{sub 2} (X=P, As, Sb) chalcopyrite semiconductor. Semiconductors ZnSnX{sub 2} (X=P, As, Sb) are found to be direct band gap semiconductors with band gaps 1.23, 0.68 and 0.19 eV respectively. The quantitative estimate of effects of p–d hybridization, structural distortion and cation electronegativity shows band gaps change significantly due to these effects. Highlights: ► ZnSnX{sub 2} (X=P, As, Sb) are direct band gap semiconductors. ► These have band gaps of 1.23 eV, 0.68 eV and 0.19 eV respectively. ► The band gap reduction due to p–d hybridization is 13.41%, 18.51% and 40% respectively. ► Band gap reduction due to structural distortion is 12.12%, 11.11% and 16.66% respectively. ► Band gap increases 8.38%, 3.70% and 21.31% respectively due to cation electronegativity.« less

Purification, crystallization and X-ray diffraction analysis of the C-terminal protease domain of Venezuelan equine encephalitis virus nsP2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russo, Andrew T.; Watowich, Stanley J., E-mail: watowich@xray.utmb.edu

2006-06-01

The C-terminal protease domain of Venezuelan equine encephalitis virus (VEEV) nsP2 has been overexpressed in E. coli, purified and successfully crystallized. Native crystals diffract to beyond 2.5 Å resolution and isomorphous heavy-atom derivatives suitable for phase analysis have been identified. The C-terminal region of Venezuelan equine encephalitis virus (VEEV) nsP2 is responsible for proteolytic processing of the VEEV polyprotein replication complex. This action regulates the activity of the replication complex and is essential for viral replication, thus making nsP2 a very attractive target for development of VEEV therapeutics. The 338-amino-acid C-terminal region of VEEV nsP2 has been overexpressed in Escherichiamore » coli, purified and crystallized. Crystals diffract to beyond 2.5 Å resolution and belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}. Isomorphous heavy-atom derivatives suitable for phase analysis have been obtained and work on building a complete structural model is under way.« less

Pt anti-cancer drug interactions with oligodeoxyribonucleotides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fouts, C.S.

The Pt adducts of d(TGGT) were investigated by /sup 31/P and /sup 1/H NMR spectroscopy with the following compounds: cisPtA/sub 2/Cl/sub 2/ (A/sub 2/ = en, (NH/sub 3/)/sub 2/, (MeNH/sub 2/)/sub 2/, tn, Me/sub 2/ tn, and N,N-Me/sub 2/en) and transPt (NH/sub 3/)/sub 2/Cl/sub 2/. Limited studies were performed with d(TTGG), D(GGTT), D(pGGTT), and d(TAGT). For d(TGGT)Pt(en) and d(TGGT)cisPt(MeNH/sub 2/)/sub 2/, the downfield /sup 31/P NMR signal was assigned to the GpG moiety by selective 2D NMR techniques. It was demonstrated that Pt formed a crosslink with the GpG moiety and the G's were in a head-to-head configuration. A downfieldmore » /sup 31/P NMR signal appears to be characteristic of Pt-crosslinked species and can be correlated with potential hydrogen bonding ability of the Pt complexes and the oligonucleotides. The signal was not shifted as far downfield when the group cis to the 5' G was incapable of hydrogen bonding or when no phosphate group was 5' to the GpG moiety.« less

Syntheses, spectroscopic characterizations, and X-ray structures of new Os({eta}{sup 2}-H{sub 2}) compounds containing azole ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esteruelas, M.A.; Lahoz, F.J.; Oro, L.A.

1994-02-16

The dihydrido-dichloro complex OsH{sub 2}Cl{sub 2}(P-i-Pr{sub 3}){sub 2} (1) reacts with 2,2{prime}-biimidazole (H{sub 2}bim) to give the dihydrogen derivative [OsCl({eta}{sup 2}-H{sub 2})(H{sub 2}bim)(P-i-Pr{sub 3}){sub 2}]Cl (2). The molecular structure of 2 has been determined by X-ray investigation. 2 crystallizes with a dichloromethane molecule in the triclinic space group Pl. The coordination geometry around the osmium center can be rationalized as a distorted octahedron with the two phosphine ligands disposed mutually trans. The remaining coordination sites of the octahedron are occupied by the dihydrogen ligand, the chloride atom, and by two nitrogen atoms of the chelate 2,2{prime}-biimidazole ligand. One of themore » two acidic NH groups of the 2,2{prime}-biimidazole ligand of 2 can be deprotonated by NaBH{sub 4} to give [OsCl({eta}{sup 2}-H{sub 2})(Hbim)(P-i-Pr{sub 3}){sub 2}] (3). Similarly the 2,2{prime}-biimidazole ligand of 2 is deprotonated by dimers of the type [M({mu}-OMe)(diolefin)]{sub 2} to form the heterobimetallic compounds [(P-i-Pr{sub 3}){sub 2}({eta}{sup 2}-H{sub 2})ClOs({mu}-Hbim)IrCl(COD)] (5), and [(P-i-Pr{sub 3}){sub 2}({eta}{sup 2}-H{sub 2})ClOs({mu}-Hbim)IrCl(TFB)] (TFG = tetrafluorobenzobarrelene, 6). The addition of pyrazole to 1 leads to the complex trans-dichloro-[OsCl{sub 2}({eta}{sup 2}-H{sub 2})(Hpz)(P-i-Pr{sub 3}){sub 2}] (7), which is transformed into its isomer cis-dichloro-[OsCl{sub 2}({eta}{sup 2}-H{sub 2})(Hpz)(P-i-Pr{sub 3}){sub 2}] (8) by stirring in hexane at 60 {degrees}C. The coordination geometry around the osmium center could be described as based on a distorted octahedron with the two phosphine ligands occuping the apical positions. The equatorial plane is formed by the dihydrogen and the pyrazole ligands mutually cis-disposed and the two chloride atoms are also cis-disposed.« less

Synthesis and crystal structure of (S, S, S, S)-N, N′-bis[N-(P-toluenesulfonamido)-1,2-diphenylethyl]ethylenediamine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, X.-G.; Zhang, T.; Hu, Y.-Y.

2013-12-15

(S, S, S, S)-N,N′-bis[N-(p-toluenesulfonamido)-1,2-diphenylethyl] ethylenediamine (C{sub 44}H{sub 46}N{sub 4}O{sub 4}S{sub 2}), has been synthesized and structurally characterized by elemental analysis, {sup 1}H-NMR, MS, IR and single-crystal X-ray diffraction. The title compound contains four chiral centers with C atoms in S configuration. Molecules are connected to one another by hydrogen bonds between sulfonamide nitrogen and sulfonyl oxygen to form chains alone a axis.

Crystal structure of a new variety of lead dodecaborate Pb{sub 6}(Li{sub 0.65}Na{sub 0.19})[B{sub 12}O{sub 24}]I{sub 0.84} {center_dot} 0.168H{sub 2}O and its comparison with beryl and cordierite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belokoneva, E. L., E-mail: elbel@geol.msu.ru; Derkach, I. K.; Dimitrova, O. V.

2013-05-15

Crystals of a new representative of ring-radical dodecaborates Pb{sub 6}(Li{sub 0.65}Na{sub 0.19})[B{sub 12}O{sub 24}]I{sub 0.84} {center_dot} 0.168H{sub 2}O, space group R3bar m , are obtained under hydrothermal conditions. The structure is determined with-out preliminary knowledge of the chemical formula. It is close to that of the Pb{sub 6}[B{sub 12}O{sub 24}] {center_dot} H{sub 2}O dodecaborate studied earlier, but unlike the latter structure it contains admixtures of iodide anion, lithium cation, and water molecule, which incompletely populate positions in channels. The formation of the second variety, which brings to light ion-exchange properties of the crystals, is due to mineralizing ions available inmore » the concen-trated solution in the course of crystallization. The new compound is compared with beryl and cordierite, which have close structures with channels capable of capturing various groups. Structures of synthetic Na and Ag dodecaborates with analogous but distorted ring dodecaborate radicals are discussed.« less

HAT-P-18b AND HAT-P-19b: TWO LOW-DENSITY SATURN-MASS PLANETS TRANSITING METAL-RICH K STARS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartman, J. D.; Bakos, G. A.; Torres, G.

2011-01-01

We report the discovery of two new transiting extrasolar planets. HAT-P-18b orbits the V = 12.759 K2 dwarf star GSC 2594-00646, with a period P = 5.508023 {+-} 0.000006 days, transit epoch T{sub c} = 2454715.02174 {+-} 0.00020 (BJD), and transit duration 0.1131 {+-} 0.0009 days. The host star has a mass of 0.77 {+-} 0.03 M{sub sun}, radius of 0.75 {+-} 0.04 R{sub sun}, effective temperature 4803 {+-} 80 K, and metallicity [Fe/H] = +0.10 {+-} 0.08. The planetary companion has a mass of 0.197 {+-} 0.013 M{sub J} and radius of 0.995 {+-} 0.052 R{sub J}, yielding amore » mean density of 0.25 {+-} 0.04 g cm{sup -3}. HAT-P-19b orbits the V = 12.901 K1 dwarf star GSC 2283-00589, with a period P = 4.008778 {+-} 0.000006 days, transit epoch T{sub c} = 2455091.53417 {+-} 0.00034 (BJD), and transit duration 0.1182 {+-} 0.0014 days. The host star has a mass of 0.84 {+-} 0.04 M{sub sun}, radius of 0.82 {+-} 0.05 R{sub sun}, effective temperature 4990 {+-} 130 K, and metallicity [Fe/H] = +0.23 {+-} 0.08. The planetary companion has a mass of 0.292 {+-} 0.018 M{sub J} and radius of 1.132 {+-} 0.072 R{sub J}, yielding a mean density of 0.25 {+-} 0.04 g cm{sup -3}. The radial velocity residuals for HAT-P-19 exhibit a linear trend in time, which indicates the presence of a third body in the system. Comparing these observations with theoretical models, we find that HAT-P-18b and HAT-P-19b are each consistent with a hydrogen-helium-dominated gas giant planet with negligible core mass. HAT-P-18b and HAT-P-19b join HAT-P-12b and WASP-21b in an emerging group of low-density Saturn-mass planets, with negligible inferred core masses. However, unlike HAT-P-12b and WASP-21b, both HAT-P-18b and HAT-P-19b orbit stars with super-solar metallicity. This calls into question the heretofore suggestive correlation between the inferred core mass and host star metallicity for Saturn-mass planets.« less

Hydrothermal crystal growth and Vernier structures of the metal benzenedicarboxylates MIL-47 and MIL-53 containing guest molecules of benzenecarboxylic acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xiqu; Jacobson, Allan J., E-mail: ajjacob@uh.edu

The nanoporous frameworks VO(bdc), MIL-47, and M(OH)(bdc), MIL-53; bdc=1,4-benzenedicarboxylate, can absorb various guest species in their channels. As synthesized, the channels are filled with H{sub 2}bdc molecules that have been reported to be disordered, except for [In(OH)bdc](H{sub 2}bdc){sub 3/4}, 1, which has a inorganic-organic hybrid Vernier structure with the H{sub 2}bdc molecules forming an ordered sublattice. Based on X-ray data from large single crystals grown by hydrothermal techniques, similar Vernier structures have been found for MIL-47, [VO(bdc)](H{sub 2}bdc){sub 5/7}, 2, MIL-53Al, [Al(OH)(bdc)](H{sub 2}bdc){sub 11/16}, 3, and MIL-53Ga, [Ga(OH)(bdc)](H{sub 2}bdc){sub 12/17}, 4. The Vernier structures of 2–4 at room temperature weremore » determined based on superstructure unit cells that index both host and guest sublattices: 2, space group P2{sub 1}, a=23.903(2), b=17.191(2), c=25.722(2) Å, β=105.914(8)°; 3, P2{sub 1}/n, a=105.224(4), b=12.2441(5), c=17.0143(6) Å, β=89.99(1)°; 4, P2{sub 1}, a=114.562(5), b=12.1503(5), c=17.4275(7) Å, β=89.99(1)°. The number of guest H{sub 2}bdc molecules per framework metal ion is determined by the ratio of the repeat distances of the two sublattices which depends on the size of the metal ion in the octahedral chain. The octahedral chains are parallel to [201] in 2, and to [100] in 3 and 4. Remarkably, all atoms in 3 and 4 show significant sinusoidal modulations transverse to the chain axis. - Graphical abstract: The sinusoidal modulation along the channel axis direction involving all atoms in the structure of [Al(OH)(bdc)](H{sub 2}bdc){sub 11/16}. - Highlights: • Crystal growth of MIL-47, MIL-53Al, and MIL-53Ga. • The Vernier structures have corner-sharing MO6 octrahedral chains and chains of H2BDC molecules. • The stoichiometry is determined by the ratio of the host framework to the guest H2BDC column lengths. • A correlation is established between the stoichiometry and the radius of the metal ion. • All atoms in the Al and Ga compounds show sinusoidal modulations transverse to the channel axis.« less

Crystallization and Preliminary X-ray Diffraction Analysis of Hemextin A: A Unique Anticoagulant Protein from Hemachatus haemachatus Venom

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banerjee,Y.; Kumar, S.; Jobichen, C.

2007-01-01

Hemextin A was isolated and purified from African Ringhals cobra (Hemachatus haemachatus). It is a three-finger toxin that specifically inhibits blood coagulation factor VIIa and clot formation and that also interacts with hemextin B to form a unique anticoagulant complex. Hemextin A was crystallized by the hanging-drop vapor-diffusion method by equilibration against 0.2 M ammonium acetate, 0.1 M sodium acetate trihydrate pH 4.6 and 30% PEG 4000 as the precipitating agent. The crystals belong to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 49.27, b = 49.51, c = 57.87 {angstrom} and two molecules in the asymmetricmore » unit. They diffracted to 1.5 {angstrom} resolution at beamline X25 at BNL.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yahyaoui, Samia; Rekik, Walid; Laboratoire Sciences Chimiques de Rennes

The crystal structures of 1,4-diazabicyclo[2.2.2]octane (dabco)-templated iron sulfate, (C{sub 6}H{sub 14}N{sub 2})[Fe(H{sub 2}O){sub 6}](SO{sub 4}){sub 2}, were determined at room temperature and at -173 deg. C from single-crystal X-ray diffraction. At 20 deg. C, it crystallises in the monoclinic symmetry, centrosymmetric space group P2{sub 1}/n, Z=2, a=7.964(5), b=9.100(5), c=12.065(5) A, {beta}=95.426(5) deg. and V=870.5(8) A{sup 3}. The structure consists of [Fe(H{sub 2}O){sub 6}]{sup 2+} and disordered (C{sub 6}H{sub 14}N{sub 2}){sup 2+} cations and (SO{sub 4}){sup 2-} anions connected together by an extensive three-dimensional H-bond network. The title compound undergoes a reversible phase transition of the first-order at -2.3 deg. C,more » characterized by DSC, dielectric measurement and optical observations, that suggests a relaxor-ferroelectric behavior. Below the transition temperature, the compound crystallizes in the monoclinic system, non-centrosymmetric space group Cc, with eight times the volume of the ambient phase: a=15.883(3), b=36.409(7), c=13.747(3) A, {beta}=120.2304(8){sup o}, Z=16 and V=6868.7(2) A{sup 3}. The organic moiety is then fully ordered within a supramolecular structure. Thermodiffractometry and thermogravimetric analyses indicate that its decomposition proceeds through three stages giving rise to the iron oxide. - Graphical abstract: The new dabcodiium hexaaquairon(II) bis(sulfate), (C{sub 6}H{sub 14}N{sub 2})[Fe(H{sub 2}O){sub 6}](SO{sub 4}){sub 2}, was prepared and characterized. It exhibits a supramolecular structure and undergoes a reversible order-disorder phase transition at -2.3 deg. C.« less

Hydrothermal synthesis and characterization of a two-dimensional piperazinium cobalt–zinc phosphate via a metastable one-dimensional phase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torre-Fernández, Laura; Khainakova, Olena A.; Espina, Aránzazu

2015-05-15

A two-dimensional piperazinium cobalt–zinc phosphate, formulated as (C{sub 4}N{sub 2}H{sub 12}){sub 1.5}(Co{sub 0.6}Zn{sub 0.4}){sub 2}(HPO{sub 4}){sub 2}(PO{sub 4})·H{sub 2}O (2D), was synthesized under hydrothermal conditions. The crystal structure was determined using single-crystal X-ray diffraction data (monoclinic P2{sub 1}/c, a=8.1165(3) Å, b=26.2301(10) Å, c=8.3595(4) Å, and β=110.930(5)°) and the hydrogen atom positions were optimized by DFT calculations. A single-crystal corresponding to one-dimensional metastable phase, (C{sub 4}N{sub 2}H{sub 12})Co{sub 0.3}Zn{sub 0.7}(HPO{sub 4}){sub 2}·H{sub 2}O (1D), was also isolated and the crystal structure was determined (monoclinic P2{sub 1}/c, a=8.9120(6) Å, b=14.0290(1) Å, c=12.2494(5) Å, and β=130.884(6)°). The bulk was characterized by chemical (C–H–N)more » analysis, powder X-ray diffraction (PXRD), powder X-ray thermodiffractometry (HT-XRD), transmission electron microscopy (STEM(DF)-EDX and EFTEM), and thermal analysis (TG/SDTA-MS), including activation energy data of its thermal decomposition. The magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K. - Graphical abstract: Hydrothermal synthesis and structural characterization of a two-dimensional piperazinium cobalt–zinc phosphate, (C{sub 4}N{sub 2}H{sub 12}){sub 1.5}(Co{sub 0.6}Zn{sub 0.4}){sub 2}(HPO{sub 4}){sub 2}(PO{sub 4})·H{sub 2}O (2D), have been reported. The crystal structure of a one-dimensional piperazinium cobalt–zinc phosphate, (C{sub 4}N{sub 2}H{sub 12})Co{sub 0.3}Zn{sub 0.7}(HPO{sub 4}){sub 2}·H{sub 2}O (1D) a metastable phase during the hydrothermal synthesis, was also determined. The thermal behavior of 2D compound is strongly dependent on the selected heating rate and the magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K. - Highlights: • A 2D piperazinium cobalt–zinc phosphate has been synthesized and characterized. • Crystal structure of 1D metastable phase was also determined. • Thermal behavior of 2D compound is strongly dependent on the selected heating rate. • Magnetic measurements show no magnetic ordering down to 4 K.« less

Methods of forming single source precursors, methods of forming polymeric single source precursors, and single source precursors and intermediate products formed by such methods

DOEpatents

Fox, Robert V.; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin; Margulieux, Kelsey R.; Holland, Andrew W.

2012-12-04

Methods of forming single source precursors (SSPs) include forming intermediate products having the empirical formula 1/2{L.sub.2N(.mu.-X).sub.2M'X.sub.2}.sub.2, and reacting MER with the intermediate products to form SSPs of the formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2, wherein L is a Lewis base, M is a Group IA atom, N is a Group IB atom, M' is a Group IIIB atom, each E is a Group VIB atom, each X is a Group VIIA atom or a nitrate group, and each R group is an alkyl, aryl, vinyl, (per)fluoro alkyl, (per)fluoro aryl, silane, or carbamato group. Methods of forming polymeric or copolymeric SSPs include reacting at least one of HE.sup.1R.sup.1E.sup.1H and MER with one or more substances having the empirical formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2 or L.sub.2N(.mu.-X).sub.2M'(X).sub.2 to form a polymeric or copolymeric SSP. New SSPs and intermediate products are formed by such methods.

Crystallization and preliminary crystallographic study of the yeast Malassezia sympodialis allergen Mala s 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vilhelmsson, Monica, E-mail: monica.vilhelmsson@medks.ki.se; Center for Infectious Medicine, Department of Medicine, Karolinska University Hospital, Huddinge, Stockholm; Hallberg, B. Martin

2006-02-01

Crystals of the M. sympodialis allergen Mala s 1 have been obtained using the hanging-drop vapour-diffusion method. A diffraction data set has been collected from native crystals to 1.35 Å resolution. The opportunistic yeast Malassezia sympodialis can act as an allergen and elicit specific IgE- and T-cell reactivity in patients with atopic eczema. The first identified major allergen from M. sympodialis, Mala s 1, is present on the cell surface of the yeast. Recombinant Mala s 1 was expressed in Escherichia coli, purified and refolded in a soluble form. Crystals of Mala s 1 were obtained in 25% PEG 8K,more » 0.2 M (NH{sub 4}){sub 2}SO{sub 4}. Crystals belong to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 44.4, b = 163.7, c = 50.6 Å, and diffract to 1.35 Å resolution.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shafeie, S.; Dreyer, B.; Awater, R.H.P

New La-deficient double perovskites with P2{sub 1}/n symmetry, La{sub ∼1.90}(Co{sup 2+}{sub 1−x}Mg{sup 2+}{sub x})(Co{sup 3+}{sub 1/3}Nb{sup 5+}{sub 2/3})O{sub 6} with x=0, 0.13 and 0.33, and La{sub 2}(Co{sup 2+}{sub 1/2}Mg{sup 2+}{sub 1/2}) (Co{sup 3+}{sub 1/2}Nb{sup 5+}{sub 1/2})O{sub 6} were prepared by solid state reaction at 1450 °C. Their crystal structures were refined using time-of-flight neutron powder diffraction data. Our results show that certain cations such as Nb{sup 5+}, with very strong B–O bonds in the perovskite structure, can induce A-site vacancies in double perovskites. Upon heating in N{sub 2} gas atmosphere at 1200 °C ∼1% O atom vacancies are formed togethermore » with a partial reduction of the Co{sup 3+} content. The average thermal expansion coefficient between 25 and 900 °C of La{sub 1.90}(Co{sup 2+}{sub 2/3}Mg{sup 2+}{sub 1/3})(Co{sup 3+}{sub 1/3}Nb{sup 5+}{sub 2/3})O{sub 6} was determined to be 17.4 ppm K{sup −1}. Four-point electronic conductivity measurements showed that the compounds are semiconductors, with conductivities varying between 3.7·10{sup −2} and 7.7·10{sup −2} S cm{sup −1} at 600 °C and activation energies between 0.77 and 0.81 eV. Partial replacement of La{sup 3+} with Sr{sup 2+} does not lead to any increase of conductivity, while replacement of Mg{sup 2+} with Cu{sup 2+} in La{sub 1.9}CoCu{sub 1/3}Nb{sub 2/3}O{sub 6} and La{sub 1.8}CoCu{sub 1/2}Nb{sub 1/2}O{sub 6} leads to ∼100 times larger conductivities at 600 °C, 0.35 and 1.0 S cm{sup −1}, respectively, and lower activation energies, 0.57 and 0.73 eV, respectively. - Highlights: • Double perovskites, P2{sub 1}/n, La{sub 2−z}(Co{sup 2+}{sub 1−x}Mg{sup 2+}{sub x})(Co{sup 3+}{sub 1/3}Nb{sup 5+}{sub 2/3})O{sub 6} have been synthesized. • Crystal structures have been refined using neutron powder diffraction data. • Strong Nb–O bond and size ordering of Mg{sup 2+}/Co{sup 2+} and Nb{sup 5+}/Co{sup ~3+} leads to La-deficiency. • The compounds are semi conductors (~10{sup −2} S cm{sup −1}) at 600 °C. • Replacement of Mg{sup 2+} with Cu{sup 2+} leads to higher conductivity (~1.0 S cm{sup −1}) at 600 °C.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Zhang; Wanjun, Tang, E-mail: tangmailbox@126.com

Highlights: • Iso-structural garnet-type Na{sub 2}(Y,Eu)Mg{sub 2}V{sub 3}O{sub 12} solid solution were synthesized. • Efficient energy transfer from [VO{sub 4}]{sup 3−} to Eu{sup 3+} ions in this phosphor is observed obviously. • Tuning the Y/Eu ratio generates the varied hues from yellowish-green to reddish-orange. • This kind of phosphor can be potentially used in UV pumped LEDs. - Abstract: A series of solid-solution phosphors Na{sub 2}(Y,Eu)Mg{sub 2}V{sub 3}O{sub 12} were prepared using solution combustion reaction. X-ray diffraction studies verified the formation of single phase Na{sub 2}(Y,Eu)Mg{sub 2}V{sub 3}O{sub 12} with garnet structure. Na{sub 2}(Y,Eu)Mg{sub 2}V{sub 3}O{sub 12} phosphors show notmore » only a broad emission band with a maximum at 510 nm due to the [VO{sub 4}]{sup 3−} group but also several sharp emission lines due to the Eu{sup 3+} ions. The energy transfer from [VO{sub 4}]{sup 3−} to Eu{sup 3+} was discussed on the base of the spectral analysis. The color-tunable emissions of the Na{sub 2}(Y,Eu)Mg{sub 2}V{sub 3}O{sub 12} phosphor as a function of Y/Eu ratio are realized by continuously generating the varied hues from yellowish-green to reddish-orange. This indicates that the obtained phosphor may have potential applications in the field of UV-based white LEDs.« less

Expression, purification and crystallization of a human protein SH3BGRL at atomic resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yin, Lei; Zhu, De-Yu; Yang, Na

2005-04-01

The protein SH3BGRL, containing both SH3-binding and Homer EVH1-binding motifs, has been crystallized using the hanging-drop vapour-diffusion method. The protein SH3BGRL, containing both SH3-binding and Homer EVH1-binding motifs, has been crystallized using the hanging-drop vapour-diffusion method. The crystals diffract to 0.88 Å resolution and belong to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 28.8886, b = 34.9676, c = 98.0016 Å. Preliminary analysis indicates that the asymmetric unit contains one molecule and has a solvent content of about 34%.

Electrocatalytic properties of three new POMs-based inorganic–organic frameworks with flexible zwitterionic dicarboxylate ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ren, Yanli; Li, Ling; Mu, Bao

2017-05-15

Three POMs–based inorganic–organic frameworks, namely, [Cu{sub 2}(L){sub 2}(SiW{sub 12}O{sub 40})(H{sub 2}O){sub 2}]·6H{sub 2}O (1), [Co{sub 2}(L){sub 2}(SiW{sub 12}O{sub 40})(H{sub 2}O){sub 8}]·8H{sub 2}O (2) and [Ni{sub 2}(L){sub 2}(SiW{sub 12}O{sub 40})(H{sub 2}O){sub 8}]·6H{sub 2}O (3), (L=1,1′-(1,4-phenylene-bis(methylene))-bis(pyridine-3-carboxylic acid)), have been synthesized and characterized by elemental analyses, IR, XRPD, TG, and single crystal X-ray diffraction. Compound 1 contains 1D double chains decorated by (Cu{sub 2}(L){sub 4}(H{sub 2}O){sub 2}) units and the 1D chains and POMs are stacked to yield 2D frameworks. Compound 2 displays a 2D network constructed from 1D zigzag chains and POMs arranged in ABAB mode. Compound 3 consists of big squaremore » girds and the POMs are dispersed in the middle of the two adjacent girds, forming 2D networks. Compounds 1–3 all show structural integrity in aqueous solutions at different pH values and in common organic solvents. Additionally, the fluorescence and electrochemical properties of compounds 1–3 are also investigated. Compounds 1–3 exhibit good electrocatalytic activities for the reduction of NaNO{sub 2} and H{sub 2}O{sub 2}. - Highlights: • Compound 1–3 all contain different 1D chains. The noncovalent interaction of metal–organic moieties from compounds 1–3 and POMs to construct three new host–guest supramolecular compounds. • Compounds 1–3 show good electrocatalytic activities towards the reduction of NaNO{sub 2} and H{sub 2}O{sub 2}. • Compounds 1–3 all show structural integrity in aqueous solutions at different pH values and in common organic solvents. • Compounds 1–3 may be promising luminescent materials due to their luminescent properties.« less

Crystallization and preliminary X-ray diffraction studies of polyketide synthase-1 (PKS-1) from Cannabis sativa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taguchi, Chiho; Quantum Beam Science Directorate, Japan Atomic Energy Agency; Taura, Futoshi

Polyketide synthase-1 from C. sativa has been crystallized. The crystal diffracted to 1.55 Å resolution with sufficient quality for further structure determination. Polyketide synthase-1 (PKS-1) is a novel type III polyketide synthase that catalyzes the biosynthesis of hexanoyl triacetic acid lactone in Cannabis sativa (Mexican strain). PKS-1 was overproduced in Escherichia coli, purified and finally crystallized in two different space groups. The crystal obtained in 0.1 M HEPES buffer pH 7.5 containing 0.2 M calcium acetate and 20%(w/v) polyethylene glycol 3350 diffracted to 1.65 Å resolution and belonged to space group P1, with unit-cell parameters a = 54.3, b =more » 59.3, c = 62.6 Å, α = 69, β = 81, γ = 80°. Another crystal obtained in 0.1 M HEPES buffer pH 7.5 containing 0.2 M sodium chloride and 20%(w/v) polyethylene glycol 3350 diffracted to 1.55 Å resolution and belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 54.3, b = 110, c = 130 Å. These data will enable us to determine the crystal structure of PKS-1.« less

Correlation Of 2-Chlorobiphenyl Dechlorination By Fe/Pd With Iron Corrosion At Different pH

EPA Science Inventory

The rate of 2-chlorobiphenyl dechlorination by palladized iron (Fe/Pd) decreased with increasing pH until pH > 12.5. Iron corrosion potential (E_c) and current (j_c), obtained from polarization curves of a rotating disk electrode of iron, followed the Tafel e...

Preliminary crystallographic analysis of salicylate 1,2-dioxygenase from Pseudaminobacter salicylatoxidans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matera, I.; Ferraroni, M.; Bürger, S.

2006-06-01

Salicylate 1,2-dioxygenase, a new ring-fission dioxygenase from the naphthalenesulfonate-degrading strain P. salicylatoxidans, which oxidizes salicylate to 2-oxohepta-3,5-dienedioic acid by a novel ring-fission mechanism, has been crystallized. The crystals obtained give diffraction data to 2.9 Å resolution which could assist in the elucidation of the catalytic mechanism of this peculiar dioxygenase. Salicylate 1,2-dioxygenase, a new ring-fission dioxygenase from the naphthalenesulfonate-degrading strain Pseudaminobacter salicylatoxidans which oxidizes salicylate to 2-oxohepta-3,5-dienedioic acid by a novel ring-fission mechanism, has been crystallized. Diffraction-quality crystals of salicylate 1,2-dioxygenase were obtained using the sitting-drop vapour-diffusion method at 277 K from a solution containing 10%(w/v) ethanol, 6%(w/v) PEG 400,more » 0.1 M sodium acetate pH 4.6. Crystals belong to the primitive tetragonal space group P4{sub 3}2{sub 1}2 or P4{sub 1}2{sub 1}2, with unit-cell parameters a = 133.3, c = 191.51 Å. A complete data set at 100 K extending to a maximum resolution of 2.9 Å was collected at a wavelength of 0.8423 Å. Molecular replacement using the coordinates of known extradiol dioxygenases structures as a model has so far failed to provide a solution for salicylate 1,2-dioxygenase. Attempts are currently being made to solve the structure of the enzyme by MAD experiments using the anomalous signal of the catalytic Fe{sup II} ions. The salicylate 1,2-dioxygenase structural model will assist in the elucidation of the catalytic mechanism of this ring-fission dioxygenase from P. salicylatoxidans, which differs markedly from the known gentisate 1,2-dioxygenases or 1-hydroxy-2-naphthoate dioxygenases because of its unique ability to oxidatively cleave salicylate, gentisate and 1-hydroxy-2-naphthoate with high catalytic efficiency.« less

Coordination polymers with the chiral ligand N-p-tolylsulfonyl-L-glutamic acid: Influence of metal ions and different bipyridine ligands on structural chirality

DOE Office of Scientific and Technical Information (OSTI.GOV)

He Rong; Song Huihua, E-mail: songhuihua@mail.hebtu.edu.c; Wei Zhen

2010-09-15

Four new polymers, namely [Ni(-tsgluO)(2,4'-bipy){sub 2}(H{sub 2}O){sub 2}]{sub n}.5nH{sub 2}O (1), [Co(-tsgluO)(2,4'-bipy){sub 2}(H{sub 2}O){sub 2}]{sub n}.5nH{sub 2}O (2), [Ni(-tsgluO)(4,4'-bipy)]{sub n}.0.5nH{sub 2}O (3), and [Co(-tsgluO)(4,4'-bipy)]{sub n}.0.5nH{sub 2}O (4), where tsgluO{sup 2-}=(+)-N-p-tolylsulfonyl-L-glutamate dianion, 2,4'-bipy=2,4'-bipyridine, and 4,4'-bipy=4,4'-bipyridine, have been prepared and structurally characterized. Compounds 1 and 2 are isostructural and mononuclear, and crystallize in the acentric monoclinic space group Cc, forming 1D chain structures. Compound 3 is also mononuclear, but crystallizes in the chiral space group P2{sub 1}, forming a homochiral 2D architecture. In contrast to the other complexes, compound 4 crystallizes in the space group P-1 and is composed of binuclear [Co{submore » 2}O{sub 6}N{sub 2}]{sub n}{sup 4-} units, which give rise to a 2D bilayer framework. Moreover, compounds 1, 2, and 4 self-assemble to form 3D supramolecular structures through {pi}-{pi} stacking and hydrogen-bonding interactions, while compound 3 is further hydrogen-bonded to form 3D frameworks. We have demonstrated the influence of the central metal and bipyridine ligands on the framework chirality of the coordination complexes. - Graphical abstract: Four novel polymers based on a chiral ligand were prepared and structurally characterized; it represents the first series of investigations about the effect of central metals and bipyridine ligands on framework chirality.« less

Unsaturated Mn complex decorated hybrid thioarsenates: Syntheses, crystal structures and physical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yue, Cheng-Yang; State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002; Lei, Xiao-Wu, E-mail: xwlei_jnu@163.com

2016-03-15

The incorporation of unsaturated [Mn(1,2-dap)]{sup 2+}, [Mn(1,2-dap){sub 2}]{sup 2+}, [Mn(2,2-bipy)]{sup 2+} (1,2-dap=1,2-diaminopropane) complex cations with thioarsenate anions of [As{sup III}S{sub 3}]{sup 3−} and [As{sup V}S{sub 4}]{sup 3−} led to three new hybrid manganese thioarsenates, namely, [Mn(1,2-dap)]{sub 2}MnAs{sub 2}S{sub 6} (1), [Mn(1,2-dap){sub 2}]{[Mn(1,2-dap)]_2As_2S_8} (2) and (NH{sub 4})[Mn(2,2-bipy){sub 2}]AsS{sub 4} (3). In compound 1, the unsaturated [Mn(1,2-dap)]{sup 2+} complexes, [MnS{sub 4}]{sup 6−} tetrahedra and [As{sup III}S{sub 3}]{sup 3−} trigonal-pyramids are condensed to form the 1D [Mn(1,2-dap)]{sub 2}MnAs{sub 2}S{sub 6} chain, whereas compound 2 features 2D layer composed of [Mn(1,2-dap)]{sup 2+} and [Mn(1,2-dap){sub 2}]{sup 2+} complexes as well as [As{sup V}S{sub 4}]{sup 3−}more » tetrahedral units. For compound 3, two [As{sup V}S{sub 4}]{sup 3−} anions bridge two [Mn(2,2-bipy)]{sup 2+} complex cations into a butterfly like {[Mn(2,2-bipy)]_2As_2S_8}{sup 2−} anionic unit. Magnetic measurements indicate the ferrimagnetic behavior for compound 1 and antiferromagnetic (AF) behaviors for compounds 2–3. The UV–vis diffuse-reflectance measurements and electronic structural calculations based on density functional theory (DFT) revealed the title compounds belong to semiconductors with band gaps of 2.63, 2.21, and 1.97 eV, respectively. The narrow band-gap of compound 3 led to the efficient and stable photocatalytic degradation activity over organic pollutant than N-doped P25 under visible light irradiation. - Highlights: Three new hybrid manganese thioarsenates have been prepared and structurally characterized. These hybrid phases feature interesting magnetic and visible light responding photocatalytic properties.« less

Process for selective production of di- and tri-alkylamines

DOEpatents

Klier, Kamil; Herman, Richard G.; Vedage, Gamini A.

1984-01-01

A primary alkyl amine and an alcohol of up to 12 carbon atoms are reacted at low temperature (50.degree.-250.degree. C.) over specific catalysts (alkali-treated catalysts generally or binary Cu/ZnO and Pd/SiO.sub.2 systems, with or without alkali treatment) to produce, with good selectivity, secondary and tertiary alkylamines of the general formula, R.sub.1 N(R.sub.2).sub.2, wherein R.sub.1 is a lower alkyl or an aryl group, and R.sub.2 is hydrogen or another lower alkyl or aryl group, with at least one of R.sub.2 's being an alkyl or aryl group.

Metal–organic frameworks assembled from lanthanide and 2,5-pyridinedicaboxylate with cubane-like [Ln{sub 4}(OH){sub 4}] building units

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelbaky, Mohammed S.M.; Amghouz, Zakariae, E-mail: amghouz.uo@uniovi.es; Servicios Científico-Técnicos, University of Oviedo—CINN, Oviedo 33006

Lanthanide–organic frameworks based on 2,5-pyridinedicaboxylate (25p) ligand, formulated as [Yb{sub 4}(OH){sub 4}(25p){sub 4}(H{sub 2}O){sub 3}]·H{sub 2}O (25pYb), [Y{sub 4}(OH){sub 4}(25p){sub 4}(H{sub 2}O){sub 3}]·H{sub 2}O (25pY-1) and [Y{sub 6}(OH){sub 8}(25p){sub 5}(H{sub 2}O){sub 2}] (25pY-2), have been obtained as single phases under hydrothermal conditions. 25pYb and 25pY-1 are isostructural, and crystallize in the triclinic space group, P-1, with a=8.6075(5) Å, b=14.8478(7) Å, c=15.9164(9) Å, α=86.277(4)°, β=80.196(5)°, γ=81.785(4)°, and a=8.7166(6) Å, b=14.966(1) Å, c=15.966(1) Å, α=86.260(6)°, β=80.036(6)°, γ=81.599(6)°, respectively. 25pY-2 crystallizes in the monoclinic space group, P2{sub 1}/c, with a=24.9117(17) Å, b=13.7340(8) Å, c=14.3385(10) Å, β=100.551(7)°. 25pYb and 25pY-2 have been structurally characterizedmore » by single-crystal X-ray diffraction. The 25pYb structure is based on tetranuclear cubane-like [Yb{sub 4}(OH){sub 4}]{sup 8+} clusters, which are interconnected to eight neighbouring clusters through teen surrounding 25p ligands leading to neutral 3D framework, while the structure of 25pY-2 is based on two independent cuban-like [Y{sub 4}(OH){sub 4}]{sup 8+} clusters, which are joined together through Y1 cation leading to the formation of hexanuclear [Y{sub 6}(OH){sub 8}]{sup 10+} clusters, which in turn are joined via Y2 cation resulting in infinite inorganic chain extending along c-axis, and each chain is interconnected to six adjacent chains through 25p ligands leading finally to 3D framework. The luminescence properties of Eu{sup 3+} and Tb{sup 3+} doped 25pY-1 and 25pY-2 compounds have also been investigated. All materials has been characterized by powder X-ray diffraction, thermal analyses (TG–SDTA–MS), FTIR spectroscopy, C–H–N elemental analysis, scanning electron microscopy (SEM-EDX), and powder X-ray thermodiffraction. - Graphical abstract: Nowadays, lanthanide–organic frameworks (LOFs) attract tremendous attention due to the unique characteristic of lanthanide cations, such as variable coordination numbers and geometries which often lead to novel complex structures, and also to their magnetic and photoluminescence properties. Herein, three LOFs formulated as [Ln{sub 4}(OH){sub 4}(25p){sub 4}(H{sub 2}O){sub 3}]·H{sub 2}O (Ln=Y, Yb) and [Y{sub 6}(OH){sub 8}(25p){sub 5}(H{sub 2}O){sub 2}] have been obtained by hydrothermal method and characterized, and the photoluminescence properties of the Eu and Tb doped compounds are discussed. - Highlights: • Three novel LnOFs has been synthesized and characterized. • Crystal structures are based on tetranuclear cuban-like [Ln{sub 4}(OH){sub 4}]{sup 8+} clusters. • 25pYb and 25pY-1 are based on isolated [Ln{sub 4}(OH){sub 4}]{sup 8+} clusters. • 25pY-2 is based on infinite inorganic chains built up from [Y{sub 4}(OH){sub 4}]{sup 8+} clusters. • Photoluminescence studies show strong red and green light emissions.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chao, Tzu-Ling; Yang, Chen-I., E-mail: ciyang@thu.edu.tw

The preparations and properties of three new homochiral three-dimensional (3D) coordination polymers, [M(D-cam)(pyz)(H{sub 2}O){sub 2}]{sub n} (M=Co (1) and Ni (2); D-H{sub 2}cam=(+) D-camphoric acid; pyz=pyrazine) and [Mn{sub 2}(D-cam){sub 2}(H{sub 2}O){sub 2}] (3), under solvothermal conditions is described. Single-crystal X-ray diffraction analyses revealed that all of compounds are homochiral 3D structure. 1 and 2 are isostructural and crystallize in the trigonal space group P3{sub 2}21, while 3 crystallizes in monoclinic space group P2{sub 1}. The structure of 1 and 2 consists of metal-D-cam helical chains which are pillared with pyrazine ligands into a 3D framework structure and 3 features amore » 3D homochiral framework involving one-dimensional manganese-carboxylate chains that are aligned parallel to the b axis. Magnetic susceptibility data of all compounds were collected. The findings indicate that μ{sub 2}-pyrazine dominate weak antiferromagnetic coupling within 1 and 2, while 3 exhibits antiferromagnetic behavior through the carboxylate groups of D-cam ligand. -- Graphical abstract: The preparations and properties of three new homochiral three-dimensional (3D) coordination polymers, [M(D-cam)(pyz)(H{sub 2}O){sub 2}]{sub n} (M=Co (1) and Ni (2); D-H{sub 2}cam=(+) D-camphoric acid; pyz=pyrazine) and [Mn{sub 2}(D-cam){sub 2}(H{sub 2}O){sub 2}] (3), under solvothermal conditions is described. Single-crystal X-ray diffraction analyses revealed that all of compounds are homochiral 3D structure. 1 and 2 are isostructural and crystallize in the trigonal space group P3{sub 2}21, while 3 crystallizes in monoclinic space group P2{sub 1}. The structure of 1 and 2 consists of metal-D-cam helical chains which are pillared with pyrazine ligands into a 3D framework structure and 3 features a 3D homochiral framework involving one-dimensional manganese-carboxylate chains that are aligned parallel to the b axis. Magnetic susceptibility data of all compounds were collected. The findings indicate that μ{sub 2}-pyrazine dominate weak antiferromagnetic coupling within 1 and 2, while 3 exhibits antiferromagnetic behavior through the carboxylate groups of D-cam ligand. Highlights: • Three homochiral 3D coordination polymers were synthesized. • 1 and 2 are 3D structure with metal-D-cam helical chains pillared by pyrazine. • 3 shows a 3D homochiral framework involving 1D manganese-carboxylate chains. • Magnetic data analysis indicates that 1–3 exhibit weak antiferromagnetic coupling.« less

Conversion of 3-imidazoline-3-oxide nitroxyl radicals into nitronylnitroxyl radicals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grigor'ev, I.A.; Shchukin, G.I.; Khramtsov, V.V.

1986-04-20

Continuing the studies of the effect of the pH of the medium on the EPR spectra of nitroxyl radicals (NR) containing acid-base functional groups at a distance of 2-3 sigma-bonds from the radical center, they have examined the EPR spectra of NR, which contain OH groups in the 2-position of the heterocycle. It is assumed that deprotonation of the OH group is accompanied by changes in the hfc constant a/sub N//sup 1/ and the g-factor. At pH values greater than or equal to 12, however, the EPR spectra of aqueous solutions of radicals undergo irreversible changes from a triplet tomore » a more complex multiplet, similar to the spectra of nitronylnitroxyl radicals. The EPR spectra of these solutions remain unchanged over periods of several days. The spectra have a quintet structure, with further splitting into four or three components. When similar experiments are carried out in D/sub 2/O, the additional hfs disappear as a result of deuterium exchange in the CH/sub 2/ and CH/sub 3/ groups of the radicals. A simulation of the EPR spectra was carried out, assuming splitting into two N nuclei (a/sub N//sup 1/ and a/sub N//sup 3/), with three or two equivalent H. This resulted in complete agreement between the calculated and experimental spectra. In order to assign the nitrogen hfc constants, they synthesized radicals containing the N/sup 15/ isotope in the 3-position of the imidazole ring. Comparison of the results of simulations of the EPR spectra enabled unambiguous assignments of the hfc constants a/sub N//sup 1/ and a/sub N//sup 3/ to be made.« less

Menzerite-(Y) a New Species {(Y REE)(Ca Fe2plus)2}[(Mg Fe2plus)(Fe3plus Al)](Si3)O12 from a Felsic Granulite Parry Sound Ontario and a New Garnet End-member (Y2Ca)Mg2(SiO4)3

DOE Office of Scientific and Technical Information (OSTI.GOV)

E Grew; J Marsh; M Yates

2011-12-31

Menzerite-(Y), a new mineral species, forms reddish brown cores, n = 1.844 (20), up to 70 {micro}m across, rimmed successively by euhedral almandine containing up to 2.7 wt% Y{sub 2}O{sub 3} and by K-feldspar in a felsic granulite on Bonnet Island in the interior Parry Sound domain, Grenville Orogenic Province, Canada. It is named after Georg Menzer (1897-1989), the German crystallographer who solved the crystal structure of garnet. Single-crystal X-ray-diffraction results yielded space group Ia3d, a = 11.9947(6) {angstrom}. An electron-microprobe analysis of the grain richest in Y (16.93 wt% Y{sub 2}O{sub 3}) gave the following formula, normalized to eightmore » cations and 12 oxygen atoms: {l_brace}Y{sub 0.83}Gd{sub 0.01}Dy{sub 0.05}Ho{sub 0.02}Er{sub 0.07}Tm{sub 0.01}Yb{sub 0.06}Lu{sub 0.02}Ca{sub 1.37}Fe{sub 0.49}{sup 2+}Mn{sub 0.07}{r_brace} [Mg{sub 0.55}Fe{sub 0.42}{sup 2+}Fe{sub 0.58}{sup 3+}Al{sub 0.35} V{sub 0.01}Sc{sub 0.01}Ti{sub 0.08}](Si{sub 2.82}Al{sub 0.18})O{sub 12}, or {l_brace}(Y,REE)(Ca,Fe{sup 2+}){sub 2}{r_brace}[(Mg,Fe{sup 2+})(Fe{sup 3+},Al)](Si{sub 3})O{sub 12}. Synchrotron micro-XANES data gave Fe{sup 3+}/{Sigma}Fe = 0.56(10) versus 0.39(2) calculated from stoichiometry. The scattering power refined at the octahedral Y site, 17.68 epfu, indicates that a relatively light element contributes to its occupancy. Magnesium, as determined by electron-microprobe analyses, would be a proper candidate. In addition, considering the complex occupancy of this site, the average Y-O bond length of 2.0244(16) {angstrom} is in accord with a partial occupancy by Mg. The dominance of divalent cations with Mg > Fe{sup 2+} and the absence of Si at the octahedral Y site (in square brackets) are the primary criteria for distinguishing menzerite-(Y) from other silicate garnet species; the menzerite-(Y) end-member is {l_brace}Y{sub 2}Ca{r_brace}[Mg{sub 2}](Si{sub 3})O{sub 12}. The contacts of menzerite-(Y) with almandine are generally sharp and, in places, cuspate. It is interpreted to have equilibrated with ferrosilite, augite, quartz, oligoclase, allanite-(Ce), magnetite, ilmenite and fluorapatite, in the absence of almandine, on the prograde path at 7-8.5 kbar and T {approx} 700-800 C, and subsequently dissolved incongruently in an anatectic melt to form almandine, most likely, at P {approx} 8.5-9.5 kbar and T {approx} 800-850 C.« less

Crystallization and preliminary X-ray analysis of alginate lyases A1-II and A1-II′ from Sphingomonas sp. A1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamasaki, Masayuki; Ogura, Kohei; Moriwaki, Satoko

The crystallization and preliminary characterization of the family PL-7 alginate lyases A1-II and A1-II′ from Sphingomonas sp. A1 are presented. Alginate lyases depolymerize alginate, a heteropolysaccharide consisting of α-l-guluronate and β-d-mannuronate, through a β-elimination reaction. The alginate lyases A1-II (25 kDa) and A1-II′ (25 kDa) from Sphingomonas sp. A1, which belong to polysaccharide lyase family PL-7, exhibit 68% homology in primary structure but have different substrate specificities. To determine clearly the structural basis for substrate recognition in the depolymerization mechanism by alginate lyases, both proteins were crystallized at 293 K using the vapour-diffusion method. A crystal of A1-II belonged tomore » space group P2{sub 1} and diffracted to 2.2 Å resolution, with unit-cell parameters a = 51.3, b = 30.1, c = 101.6 Å, β = 100.2°, while a crystal of A1-II′ belonged to space group P2{sub 1}2{sub 1}2{sub 1} and diffracted to 1.0 Å resolution, with unit-cell parameters a = 34.6, b = 68.5, c = 80.3 Å.« less

Crystallization and preliminary X-ray crystallographic analysis of a carbonyl reductase from Candida parapsilosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Rongzhen; Xu, Yan, E-mail: biosean@yahoo.com.cn; Sun, Ying

2008-04-01

A novel short-chain NADPH-dependent (S)-1-phenyl-1,2-ethanediol dehydrogenase (SCR) has been crystallized. A novel short-chain NADPH-dependent (S)-1-phenyl-1,2-ethanediol dehydrogenase (SCR) has been crystallized. Two distinct but related crystal forms of SCR were obtained using the hanging-drop vapour-diffusion method and a reservoir solution consisting of 18%(w/v) polyethylene glycol 2000 monomethyl ether and 8%(v/v) 2-propanol as the precipitant. The crystals were rhomboid in shape with average dimensions of 0.3 × 0.3 × 0.4 mm and diffracted to a resolution of 2.7–3.0 Å. The crystal forms both belong to space group P2{sub 1}2{sub 1}2{sub 1} and have unit-cell parameters a = 104.7, b = 142.8, cmore » = 151.8 Å and a = 101.1, b = 146.0, c = 159.8 Å. The calculated values of V{sub M}, rotation-function and translation-function solutions and consideration of potential crystal packing suggest that there are eight protein subunits per asymmetric unit.« less

Protein preparation and preliminary X-ray crystallographic analysis of a putative glucosamine 6-phosphate deaminase from Streptococcus mutants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Guan-Jing; Li, Lan-Fen; Li, Dan

2007-09-01

A glucosamine 6-phosphate deaminase homologue from S. mutans was expressed, purified and crystallized. Diffraction data have been collected to 2.4 Å resolution. The SMU.636 protein from Streptococcus mutans is a putative glucosamine 6-phosphate deaminase with 233 residues. The smu.636 gene was PCR-amplified from S. mutans genomic DNA and cloned into the expression vector pET-28a(+). The resultant His-tagged fusion protein was expressed in Escherichia coli and purified to homogeneity in two steps. Crystals of the fusion protein were obtained by the hanging-drop vapour-diffusion method. The crystals diffracted to 2.4 Å resolution and belong to space group P2{sub 1}2{sub 1}2{sub 1}, withmore » unit-cell parameters a = 53.83, b = 82.13, c = 134.70 Å.« less

Beta cell device using icosahedral boride compounds

DOEpatents

Aselage, Terrence L.; Emin, David

2002-01-01

A beta cell for converting beta-particle energies into electrical energy having a semiconductor junction that incorporates an icosahedral boride compound selected from B.sub.12 As.sub.2, B.sub.12 P.sub.2, elemental boron having an .alpha.-rhombohedral structure, elemental boron having a .beta.-rhombohedral structure, and boron carbides of the chemical formula B.sub.12-x C.sub.3-x, where 0.15

Lamb shift and fine structure of n = 2 in /sup 35/C1 XVI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berry, H.G.; DeSerio, R.; Livingston, A.E.

We have measured the wavelengths of the 2s /sup 3/S/sub 1/-2p /sup 3/P/sub 2/ and 2s /sup 3/S/sub 1/ -- 2p /sup 3/P/sub 0/ transitions in C1 XVI to be 613.825 +- 0.013 A and 705.854 +- 0.076 A. Our precision is sufficient to provide measurements of the 2s/sub 1/2/-2p/sub 3/2/ Lamb shifts to an accuracy of +- 0.3% and to test quantum electrodynamics (QED) theory in the strong-field region. We compres our results with the one-electron QED theories of Mohr and Erickson and discuss the accuracy of calculations of electron correlation in two-electron atoms.

Structural and magnetic characterization of three tetranuclear Cu(II) complexes with face-sharing-dicubane/double-open-cubane like core framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul, Aparup; Bertolasi, Valerio; Figuerola, Albert

Three novel tetranuclear copper(II) complexes namely [Cu{sub 4}(L{sup 1}){sub 4}]∙2(dmf) (1), [Cu{sub 4}(L{sup 1}){sub 4}] (2) and [Cu{sub 4}(L{sup 2}){sub 2}(HL{sup 2}){sub 2}(H{sub 2}O){sub 2}]∙2(ClO{sub 4})·6(H{sub 2}O) (3) (H{sub 2}L{sup 1}, (E)−2-((1-hydroxybutan-2-ylimino)methyl)phenol; H{sub 2}L{sup 2}, (E)−2-((1-hydroxybutan-2-ylimino)methyl)−6-methoxyphenol)) were synthesized from the self-assembly of copper(II) perchlorate and the tridentate Schiff base ligands. The structural determination reveals that crystallizes in the monoclinic system with space group C2/c, whereas both the and crystallize in the triclinic system with space group P-1. and possess face-sharing dicubane core, on the other hand complex 3 has double open cubane core structure. The copper(II) ions in the cubanemore » core are in distorted square planar geometries, and weak π…π and C–H…π interactions lead to formation of a 2D supramolecular architecture for and . At room temperature and , exhibit fluorescence with a quantum yield (Φ{sub s}) of 0.47, 0.49 and 0.38, respectively. Variable temperature magnetic susceptibility measurements in the range 2–300 K indicate an overall weak antiferromagnetic exchange coupling in all complexes. The PHI program was used to study their magnetic behaviour. In agreement with their face-sharing dicubane structure, a Hamiltonian of the type H =– J{sub 1}(S{sub 1}S{sub 2}+S{sub 1}S{sub 2’}+S{sub 1'}S{sub 2}+S{sub 1'}S{sub 2’}) – J{sub 2}S{sub 1}S{sub 1’}, where S{sub 1} = S{sub 1’} = S{sub 2} = S{sub 2’} = S{sub Cu} =1/2, was used for studying and . Simulations performed suggest magnetic exchange constants with values close to J{sub 1} =−20 cm{sup −1} and J{sub 2} =0 cm{sup -1} for these complexes. On the other hand, the spin Hamiltonian H =– J{sub 1}(S{sub 1}S{sub 4}+S{sub 2}S{sub 3}) – J{sub 2}(S{sub 1}S{sub 3}+S{sub 2}S{sub 4}) – J{sub 3}S{sub 1}S{sub 2}, where S{sub 1} = S{sub 2} = S{sub 3} = S{sub 4} = S{sub Cu} =1/2, was used to study the magnetic behaviour of the double open cubane core of and a good agreement between the experimental and simulated results was found by using the parameters g{sub 1} = g{sub 2} =2.20, g{sub 3} = g{sub 4} =2.18, J{sub 1} =−36 cm{sup -1}, J{sub 2} =−44 cm{sup -1} and J{sub 3} =0 cm{sup -1}. - Graphical abstract: Tetranuclear Cu(II) complexes with face-sharing-dicubane / double-open-cubane like core frameworks were synthesized and characterized by crystal structure and magnetic analysis. Variable temperature magnetic properties corroborate with their structural arrangement. - Highlights: • Novel tetranuclear copper(II) complexes have been structurally characterized. • Complexes possess face-sharing dicubane/double open cubane core structures. • Variable temperature magnetic measurements reveal antiferromagnetic coupling. • PHI program was used to explain the observed magnetic properties.« less

Alkylation of a bioinspired high spin Ni(II)N{sub 3}S{sub 2} complex with bifunctional reagents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chohan, B. S., E-mail: bsc12@psu.edu

2013-12-15

Crystal structures of two S-alkylated complexes generated from the reaction of iodoacetamide and iodoethanol with an air and moisture sensitive high spin Ni(II) pentacoordinate triaminodithiolate complex, 1 are determined by X-ray structure analysis. Crystals of complex 2, [NiC{sub 16}H{sub 31}N{sub 5}O{sub 2}S{sub 2}]I{sub 2}, are triclinic, sp. gr. P-bar1 , Z = 2. Crystals of complex 3, [NiC{sub 16}H{sub 28}N{sub 3}O{sub 2}S{sub 2}]I{sub 2}, are monoclinic, sp. gr. P2{sub 1}/c, Z = 4. Structures of complexes 2 and 3 are very similar: one of the S-acetamide (2) or S-ethanol (3) groups coordinates to the Ni center through the oxygen atom formingmore » N{sub 3}S{sub 2}O hexacoordination; the other group remains unbound to the Ni and left dangling. Crystal packing shows that complexes 2 and 3 interact with the iodide counterions, and that only complex 2 interact with neighboring molecules; some of these close intermolecular contacts include H-bonding interactions.« less

Insect-cell expression, crystallization and X-ray data collection of the bradyzoite-specific antigen BSR4 from Toxoplasma gondii

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grujic, Ognjen; Grigg, Michael E.; Boulanger, Martin J., E-mail: mboulang@uvic.ca

2008-05-01

Preliminary X-ray diffraction studies of the bradyzoite-specific surface antigen BSR4 from T. gondii are described. Toxoplasma gondii is an important global pathogen that infects nearly one third of the world’s adult population. A family of developmentally expressed structurally related surface-glycoprotein adhesins (SRSs) mediate attachment to and are utilized for entry into host cells. The latent bradyzoite form of T. gondii persists for the life of the host and expresses a distinct family of SRS proteins, of which the bradyzoite-specific antigen BSR4 is a prototypical member. Structural studies of BSR4 were initiated by first recombinantly expressing BSR4 in insect cells, whichmore » was followed by crystallization and preliminary X-ray data collection to 1.95 Å resolution. Data processing showed that BSR4 crystallized with one molecule in the asymmetric unit of the P4{sub 1}2{sub 1}2 or P4{sub 3}2{sub 1}2 space group, with a solvent content of 60% and a corresponding Matthews coefficient of 2.98 Å{sup 3} Da{sup −1}.« less

Electrical properties of Ba(Dy{sub 1/2}Nb{sub 1/2})O{sub 3} ceramic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nath, K. Amar, E-mail: karn190@gmail.com; Chandra, K. P., E-mail: kpchandra23@gmail.com; Dubey, K., E-mail: kirandubey45@yahoo.com

2016-05-06

Polycrystalline Ba(Dy{sub 1/2}Nb{sub 1/2})O{sub 3} was prepared using a high-temperature solid-state reaction method. X-ray diffraction analysis indicated the formation of a single-phase cubic structure having space group Pm3m. AC impedance plots as a function of frequency at different temperatures were used to analyse the electrical behaviour of the sample, which indicated the negative temperature coefficient of resistance character. Complex impedance analysis targeted non-Debye type dielectric relaxation. Frequency dependent ac conductivity data obeyed Jonscher’s power law. The apparent activation energy was estimated to be 0.97 eV at 1 kHz.

New Fluorinated Polymers

NASA Technical Reports Server (NTRS)

Fitch, John W., III

1997-01-01

This report summarizes progress during 1996 in our research effort along with a description of additional results associated with a TAG supplement to this grant (items 2 and 5 below). Progress is reported in five areas: 1) Polyamides Derived from [(p-HOOCC6H4)](sub 2)C(CF3)X (X= -CF3, OCH3, Cl); 2) Phosphorus-containing '12F-PEK' - Effect of Systematic Replacement of [(p-FC6H4COC6H4)](sub 2)C[(CF3)](sub 2) Monomer by [(p-FC6H4)](sub 2)(C6H5)PO; 3) Poly(ether ketone)s Derived from [(p-FC6H4COC6H4)](sub 2)(C6H5)PO; 4) New CF3-containing Organosilane Monomers and; 5) New Monomers for 12F-PEK Analogues with Improved Processability and Solubility.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marana, S. R.; Cançado, F. C.; Valério, A. A.

The digestive lysozymes 1 and 2 from M. domestica were crystallized by vapour diffusion. The crystallographic data were processed to a maximum resolution of 1.9 Å in both cases. Lysozymes are mostly known for their defensive role against bacteria, but in several animals lysozymes have a digestive function. Here, the initial crystallographic characterization of two digestive lysozymes from Musca domestica are presented. The proteins were crystallized using the sitting-drop vapour-diffusion method in the presence of ammonium sulfate or PEG/2-propanol as the precipitant. X-ray diffraction data were collected to a maximum resolution of 1.9 Å using synchrotron radiation. The lysozyme 1more » and 2 crystals belong to the monoclinic space group P2{sub 1} (unit-cell parameters a = 36.52, b = 79.44, c = 45.20 Å, β = 102.97°) and the orthorhombic space group P2{sub 1}2{sub 1}2 (unit-cell parameters a = 73.90, b = 96.40, c = 33.27 Å), respectively. The crystal structures were solved by molecular replacement and structure refinement is in progress.« less

A general non-Abelian density matrix renormalization group algorithm with application to the C{sub 2} dimer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Sandeep, E-mail: sanshar@gmail.com

2015-01-14

We extend our previous work [S. Sharma and G. K.-L. Chan, J. Chem. Phys. 136, 124121 (2012)], which described a spin-adapted (SU(2) symmetry) density matrix renormalization group algorithm, to additionally utilize general non-Abelian point group symmetries. A key strength of the present formulation is that the requisite tensor operators are not hard-coded for each symmetry group, but are instead generated on the fly using the appropriate Clebsch-Gordan coefficients. This allows our single implementation to easily enable (or disable) any non-Abelian point group symmetry (including SU(2) spin symmetry). We use our implementation to compute the ground state potential energy curve ofmore » the C{sub 2} dimer in the cc-pVQZ basis set (with a frozen-core), corresponding to a Hilbert space dimension of 10{sup 12} many-body states. While our calculated energy lies within the 0.3 mE{sub h} error bound of previous initiator full configuration interaction quantum Monte Carlo and correlation energy extrapolation by intrinsic scaling calculations, our estimated residual error is only 0.01 mE{sub h}, much more accurate than these previous estimates. Due to the additional efficiency afforded by the algorithm, the excitation energies (T{sub e}) of eight lowest lying excited states: a{sup 3}Π{sub u}, b{sup 3}Σ{sub g}{sup −}, A{sup 1}Π{sub u}, c{sup 3}Σ{sub u}{sup +}, B{sup 1}Δ{sub g}, B{sup ′1}Σ{sub g}{sup +}, d{sup 3}Π{sub g}, and C{sup 1}Π{sub g} are calculated, which agree with experimentally derived values to better than 0.06 eV. In addition, we also compute the potential energy curves of twelve states: the three lowest levels for each of the irreducible representations {sup 1}Σ{sub g}{sup +}, {sup 1}Σ{sub u}{sup +}, {sup 1}Σ{sub g}{sup −}, and {sup 1}Σ{sub u}{sup −}, to an estimated accuracy of 0.1 mE{sub h} of the exact result in this basis.« less

Structure and magnetic properties of RE{sub 2}CuIn{sub 3} (RE=Ce, Pr, Nd, Sm and Gd)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyvanchuk, Yuriy B.; Szytula, Andrzej; Zarzycki, Arkadiusz

2008-12-15

The ternary copper indides RE{sub 2}CuIn{sub 3}{identical_to}RECu{sub 0.5}In{sub 1.5} (RE=Ce, Pr, Nd, Sm and Gd) were synthesized from the elements in sealed tantalum tubes in an induction furnace. They crystallize with the CaIn{sub 2}-type structure, space group P6{sub 3}/mmc, with a statistical occupancy of copper and indium on the tetrahedral substructure. These indides show homogeneity ranges RECu{sub x}In{sub 2-x}. Single crystal structure refinements were performed for five crystals: CeCu{sub 0.66}In{sub 1.34} (a=479.90(7) pm, c=768.12(15) pm), PrCu{sub 0.52}In{sub 1.48} (a=480.23(7) pm, c=759.23(15) pm), NdCu{sub 0.53}In{sub 1.47} (a=477.51(7) pm, c=756.37(15) pm), SmCu{sub 0.46}In{sub 1.54} (a=475.31(7) pm, c=744.77(15) pm), and GdCu{sub 0.33}In{sub 1.67}more » (a=474.19(7), c=737.67(15) pm). Temperature-dependent susceptibility measurements show antiferromagnetic ordering at T{sub N}=4.7 K for Pr{sub 2}CuIn{sub 3} and Nd{sub 2}CuIn{sub 3} and 15 K for Sm{sub 2}CuIn{sub 3}. Fitting of the susceptibility data of the samarium compound revealed an energy gap {delta}E=39.7(7) K between the ground and the first excited levels. - Graphical abstract: The CaIn{sub 2}-type structure of Sm{sub 2}CuIn{sub 3}.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piwkowska, Agnieszka, E-mail: apiwkowska@cmdik.pan.pl; Rogacka, Dorota; Angielski, Stefan

Highlights: Black-Right-Pointing-Pointer H{sub 2}O{sub 2} activates the insulin signaling pathway and glucose uptake in podocytes. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} induces time-dependent changes in AMPK phosphorylation. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} enhances insulin signaling pathways via AMPK activation. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} stimulation of glucose uptake is AMPK-dependent. -- Abstract: Podocytes are cells that form the glomerular filtration barrier in the kidney. Insulin signaling in podocytes is critical for normal kidney function. Insulin signaling is regulated by oxidative stress and intracellular energy levels. We cultured rat podocytes to investigate the effects of hydrogen peroxide (H{sub 2}O{sub 2}) on the phosphorylation of proximalmore » and distal elements of insulin signaling. We also investigated H{sub 2}O{sub 2}-induced intracellular changes in the distribution of protein kinase B (Akt). Western blots showed that H{sub 2}O{sub 2} (100 {mu}M) induced rapid, transient phosphorylation of the insulin receptor (IR), the IR substrate-1 (IRS1), and Akt with peak activities at 5 min ({Delta} 183%, P < 0.05), 3 min ({Delta} 414%, P < 0.05), and 10 min ({Delta} 35%, P < 0.05), respectively. Immunostaining cells with an Akt-specific antibody showed increased intensity at the plasma membrane after treatment with H{sub 2}O{sub 2}>. Furthermore, H{sub 2}O{sub 2} inhibited phosphorylation of the phosphatase and tensin homologue (PTEN; peak activity at 10 min; {Delta} -32%, P < 0.05) and stimulated phosphorylation of the AMP-dependent kinase alpha subunit (AMPK{alpha}; 78% at 3 min and 244% at 10 min). The stimulation of AMPK was abolished with an AMPK inhibitor, Compound C (100 {mu}M, 2 h). Moreover, Compound C significantly reduced the effect of H{sub 2}O{sub 2} on IR phosphorylation by about 40% (from 2.07 {+-} 0.28 to 1.28 {+-} 0.12, P < 0.05). In addition, H{sub 2}O{sub 2} increased glucose uptake in podocytes (from 0.88 {+-} 0.04 to 1.29 {+-} 0.12 nmol/min/mg protein, P < 0.05), and this effect was attenuated by Compound C. Our results suggested that H{sub 2}O{sub 2} activated the insulin signaling pathway and glucose uptake via AMPK in cultured rat podocytes. This signaling may play a potential role in the prevention of insulin resistance under conditions associated with oxidative stress.« less

Purification, crystallization and preliminary crystallographic studies of plant S-adenosyl-l-homocysteine hydrolase (Lupinus luteus)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brzezinski, Krzysztof; Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Poznan; Bujacz, Grzegorz

2008-07-01

Single crystals of recombinant S-adenosyl-l-homocysteine hydrolase from L. luteus in complex with adenosine diffract X-rays to 1.17 Å resolution at 100 K. The crystals are tetragonal, space group P4{sub 3}2{sub 1}2, and contain one copy of the dimeric enzyme in the asymmetric unit. By degrading S-adenosyl-l-homocysteine, which is a byproduct of S-adenosyl-l-methionine-dependent methylation reactions, S-adenosyl-l-homocysteine hydrolase (SAHase) acts as a regulator of cellular methylation processes. S-Adenosyl-l-homocysteine hydrolase from the leguminose plant yellow lupin (Lupinus luteus), LlSAHase, which is composed of 485 amino acids and has a molecular weight of 55 kDa, has been cloned, expressed in Escherichia coli and purified.more » Crystals of LlSAHase in complex with adenosine were obtained by the hanging-drop vapour-diffusion method using 20%(w/v) PEG 4000 and 10%(v/v) 2-propanol as precipitants in 0.1 M Tris–HCl buffer pH 8.0. The crystals were tetragonal, space group P4{sub 3}2{sub 1}2, with unit-cell parameters a = 122.4, c = 126.5 Å and contained two protein molecules in the asymmetric unit, corresponding to the functional dimeric form of the enzyme. Atomic resolution (1.17 Å) X-ray diffraction data have been collected using synchrotron radiation.« less

Structure cristalline de NaLiYb/sub 2/F/sub 8/: composes isotypes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dib, A.; Gorius, M.F.; Aleonard, S.

1986-11-15

NaLiYb/sub 2/F/sub 8/ crystallizes in the monoclinic system, space group C2/c, with a = 10.3516(9), b = 8.2069(9), c = 6,9674(7) A, ..beta.. = 90/sup 0/, Z = 4. The crystal structure has been solved from single crystal diffractometer measurements (AgK..cap alpha.. radiation) using Patterson and Fourier syntheses and refined by a least-squares method. The final R value is 0.021 for 1756 independent observed reflections. Two YbF/sub 8/ polyhedra share one of their edges to form Yb/sub 2/F/sub 14/ groups which are three-dimensionally linked and create cavities in which Na and Li are located. Yb/sub 2/F/sub 14/ groups share twomore » of their edges with these of one NaF/sub 7/ (or NaF/sub 9/ polyhedron to form Y/sub 2/NaF/sub 20/ blocks. As well, the structure may be described by the packing of planes formed by these two-dimensionally linked blocks. The description of this structure is compared with that ascribed to NaLiY/sub 2/F/sub 8/, which has been described in the monoclinic system, space group P2/sub 1//m, with a' = (a + b)/2, b' = c,c' = (b - a)/2, Z = 2. It is shown that positions of the atoms confer pseudoorthorhombic symmetry on the cell. Lattice parameters of isotypic compounds are given in the pseudoorthorhombic lattice and they are compared with those recently published with the structure described in the monoclinic system, space group P2/sub 1//m.« less

The use of metalorganics in the preparation of semiconductor materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manasevit, H.M.; Hewitt, W.B.; Nelson, A.J.

1989-10-01

The authors describe boron-arsenic and boron-phosphorus films grown on Si, sapphire, and silicon-on-sapphire (SOS) by pyrolyzing Group III alkyls of boron, i.e., trimethylborane (TMB) and triethylborane (TEB) in the presence of AsH/sub 3/ and PH/sub 3/, respectively, in a H/sub 2/ atmosphere. No evidence for reaction between the alkyls and the hydrides on mixing at room temperature was found. The films were predominantly amorphous. The film growth rate was found to depend on the concentration of alkyl boron compound and was essentially constant when TEB and AsH/sub 3/ were pyrolyzed over the temperature range of 550{sup 0}-900{sup 0}C. The filmsmore » were found to contain mainly carbon impurities (the amount varying with growth temperature), some oxygen, and were highly stressed and bowed on Si substrates, with some crazing evident in thin (2 {mu}m) B-P and thick (5 {mu}m) B-As films. The carbon level was generally higher in films grown using TEB as the boron source. Films grown from PH/sub 3/ and TMB showed a higher carbon content than those grown from AsH/sub 3/ and TMB. Based on their B/As and B/P ratios, films with nominal compositions B/sub 12-16/As/sub 2/P and B/sub 1.1-1.3/P were grown using TMB as the boron source.« less

Anion exchange polymer electrolytes

DOEpatents

Kim, Yu Seung; Kim, Dae Sik; Lee, Kwan-Soo

2013-07-23

Solid anion exchange polymer electrolytes and compositions comprising chemical compounds comprising a polymeric core, a spacer A, and a guanidine base, wherein said chemical compound is uniformly dispersed in a suitable solvent and has the structure: ##STR00001## wherein: i) A is a spacer having the structure O, S, SO.sub.2, --NH--, --N(CH.sub.2).sub.n, wherein n=1-10, --(CH.sub.2).sub.n--CH.sub.3--, wherein n=1-10, SO.sub.2-Ph, CO-Ph, ##STR00002## wherein R.sub.5, R.sub.6, R.sub.7 and R.sub.8 each are independently --H, --NH.sub.2, F, Cl, Br, CN, or a C.sub.1-C.sub.6 alkyl group, or any combination of thereof; ii) R.sub.9, R.sub.10, R.sub.11, R.sub.12, or R.sub.13 each independently are --H, --CH.sub.3, --NH.sub.2, --NO, --CH.sub.nCH.sub.3 where n=1-6, HC.dbd.O--, NH.sub.2C.dbd.O--, --CH.sub.nCOOH where n=1-6, --(CH.sub.2).sub.n--C(NH.sub.2)--COOH where n=1-6, --CH--(COOH)--CH.sub.2--COOH, --CH.sub.2--CH(O--CH.sub.2CH.sub.3).sub.2, --(C.dbd.S)--NH.sub.2, --(C.dbd.NH)--N--(CH.sub.2).sub.nCH.sub.3, where n=0-6, --NH--(C.dbd.S)--SH, --CH.sub.2--(C.dbd.O)--O--C(CH.sub.3).sub.3, --O--(CH.sub.2).sub.n--CH--(NH.sub.2)--COOH, where n=1-6, --(CH.sub.2).sub.n--CH.dbd.CH wherein n=1-6, --(CH.sub.2).sub.n--CH--CN wherein n=1-6, an aromatic group such as a phenyl, benzyl, phenoxy, methylbenzyl, nitrogen-substituted benzyl or phenyl groups, a halide, or halide-substituted methyl groups; and iii) wherein the composition is suitable for use in a membrane electrode assembly.

Influence of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3} content on the structure of erbium-doped borosilicate glasses and on their physical, thermal, optical and luminescence properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourhis, Kevin, E-mail: k.bourhis@argolight.com; Massera, Jonathan; Petit, Laeticia

2015-03-15

Highlights: • Reorganization of the glass structure induced by the addition of P{sub 2}O{sub 5} or Al{sub 2}O{sub 3}. • Emission properties related to the presence of P or Al in the Er{sup 3+} coordination shell. • Declustering observed upon addition of P{sub 2}O{sub 5}. • No declustering upon addition of Al{sub 2}O{sub 3}. - Abstract: The effect of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} addition in Er-doped borosilicate glasses on the physical, thermal, optical, and luminescence properties is investigated. The changes in these glass properties are related to the glass structure modifications induced by the addition of P{submore » 2}O{sub 5} and/or Al{sub 2}O{sub 3}, which were probed by FTIR, {sup 11}B MAS NMR and X-ray photoelectron spectroscopies. Variations of the polymerization degree of the silicate tetrahedra and modifications in the {sup [3]}B/{sup [4]}B ratio are explained by a charge compensation mechanism due to the formation of AlO{sub 4}, PO{sub 4} groups and the formation of Al-O-P linkages in the glass network. From the absorption and luminescence properties of the Er{sup 3+} ions at 980 nm and 1530 nm, declustering is suspected for the highest P{sub 2}O{sub 5} concentrations while for the highest Al{sub 2}O{sub 3} concentrations no declustering is observed.« less

Crystal chemistry of elpidite from Khan Bogdo (Mongolia) and its K- and Rb-exchanged forms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grigor'eva, A. A.; Zubkova, N. V., E-mail: nata_zubkova@rambler.ru; Pekov, I. V.

2011-09-15

Elpidite Na{sub 2}ZrSi{sub 6}O{sub 15} {center_dot} 3H{sub 2}O [space group Pbcm, a = 7.1312(12), b = 14.6853(12), and c = 14.6349(15) Angstrom-Sign ] from Khan Bogdo (Mongolia) and its K- and Rb-exchanged forms K{sub 1.78}Na{sub 0.16}H{sub 0.06}ZrSi{sub 6}O{sub 15} {center_dot} 0.85H{sub 2}O [Cmce, a = 14.054(3), b = 14.308(3), and c = 14.553(3) Angstrom-Sign ] and Na{sub 1.58}Rb{sub 0.2}H{sub 0.22}ZrSi{sub 6}O{sub 15} {center_dot} 2.69H{sub 2}O [Pbcm, a = 7.1280(10), b = 14.644(3), and c = 14.642(3) Angstrom-Sign ] that were obtained by cation exchange at 90 Degree-Sign C, as well as K{sub 1.84}Na{sub 0.11}H{sub 0.05}ZrSi{sub 6}O{sub 15} {center_dot} 0.91H{sub 2}Omore » [Cmce, a = 14.037(3), b = 14.226(3), and c = 14.552(3) Angstrom-Sign ] and Rb{sub 1.78}Na{sub 0.06}H{sub 0.16}ZrSi{sub 6}O{sub 15} {center_dot} 0.90H{sub 2}O [Cmce, a = 14.2999(12), b = 14.4408(15), and c = 14.7690(12) Angstrom-Sign ], obtained at 150 Degree-Sign C are studied by single-crystal X-ray diffraction and IR spectroscopy. The base of the structures is a heteropolyhedral Zr-Si-O framework whose cavities accommodate Na (K, Rb) cations and H{sub 2}O molecules.« less

Involvement of MAPKs, NF-{kappa}B and p300 co-activator in IL-1{beta}-induced cytosolic phospholipase A{sub 2} expression in canine tracheal smooth muscle cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, S.-F.; Lin, C.-C.; Chen, H.-C.

2008-11-01

Cytosolic phospholipase A{sub 2} (cPLA{sub 2}) plays a pivotal role in mediating agonist-induced arachidonic acid release for prostaglandin (PG) synthesis during stimulation with interleukin-1{beta} (IL-1{beta}). However, the mechanisms underlying IL-1{beta}-induced cPLA{sub 2} expression and PGE{sub 2} synthesis by canine tracheal smooth muscle cells (CTSMCs) have not been defined. IL-1{beta} induced cPLA{sub 2} protein and mRNA expression, PGE{sub 2} production, and phosphorylation of p42/p44 MAPK, p38 MAPK (ATF{sub 2}), and JNK (c-Jun) in a time- and concentration-dependent manner, determined by Western blotting, RT-PCR, and ELISA, which was attenuated by the inhibitors of MEK1/2 (U0126), p38 MAPK (SB202190), and JNK (SP600125), ormore » transfection with dominant negative mutants of MEK1/2, p38, and JNK, respectively. Furthermore, IL-1{beta}-induced cPLA{sub 2} expression and PGE{sub 2} synthesis was inhibited by a selective NF-{kappa}B inhibitor (helenalin) or transfection with dominant negative mutants of NF-{kappa}B inducing kinase (NIK), I{kappa}B kinase (IKK)-{alpha}, and IKK-{beta}. Consistently, IL-1{beta} stimulated both I{kappa}B-{alpha} degradation and NF-{kappa}B translocation into nucleus in these cells. NF-{kappa}B translocation was blocked by helenalin, but not by U0126, SB202190, and SP600125. MAPKs together with NF-{kappa}B-activated p300 recruited to cPLA{sub 2} promoter thus facilitating the binding of NF-{kappa}B to cPLA{sub 2} promoter region and expression of cPLA{sub 2} mRNA. IL-1{beta}-induced cPLA{sub 2} expression and PGE{sub 2} production was inhibited by actinomycin D and cycloheximide, indicating the involvement of transcriptional and translational events in these responses. These results suggest that in CTSMCs, IL-1{beta}-induced cPLA{sub 2} expression and PGE{sub 2} synthesis was independently mediated through activation of MAPKs and NF-{kappa}B pathways and was connected to p300 recruitment and activation.« less

Synthesis of [1-.sup.13C]pyruvic acid], [2-.sup.13C]pyruvic acid], [3-.sup.13C]pyruvic acid] and combinations thereof

DOEpatents

Martinez, Rodolfo A [Santa Fe, NM; Unkefer, Clifford J [Los Alamos, NM; Alvarez, Marc A [Santa Fe, NM

2009-09-01

The present invention is directed to labeled compounds, of the formulae ##STR00001## wherein C* is each independently selected from the group consisting of .sup.13C and .sup.12C with the proviso that at least one C* is .sup.13C, each hydrogen of the methylene group can independently be either hydrogen or deuterium, the methyl group includes either zero or three deuterium atoms, Q is from the group of sulfide, sulfinyl, and sulfone, Z is an aryl group from the group of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure ##STR00002## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently from the group of hydrogen, a C.sub.1-C.sub.4 lower alkyl, a halogen, and an amino group from the group of NH.sub.2, NHR and NRR' where R and R' are each independently from the group of a C.sub.1-C.sub.4 lower alkyl, a phenyl, and an alkoxy group, and the methyl group can include either zero or three deuterium atoms.

Studies on solid solutions based on layered honeycomb-ordered phases P2-Na{sub 2}M{sub 2}TeO{sub 6} (M=Co, Ni, Zn)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berthelot, Romain; Schmidt, Whitney; Sleight, A.W.

2012-12-15

Three complete solid solutions between the layered phases P2-Na{sub 2}M{sub 2}TeO{sub 6} (M=Co, Ni, Zn) have been prepared by conventional solid state method and investigated through X-ray diffraction, magnetism and optical measurements. All compositions are characterized by a M{sup 2+}/X{sup 6+} honeycomb ordering within the slabs and crystallize in a hexagonal unit cell. However, a structural transition based on a different stacking is observed as nickel (space group P6{sub 3}/mcm) is substituted by zinc or cobalt (space group P6{sub 3}22). All compositions exhibit a paramagnetic Curie-Weiss behavior at high temperatures; and the magnetic moment values confirm the presence of Ni{supmore » 2+} and/or Co{sup 2+} cations. The low-temperature antiferromagnetic order of Na{sub 2}Ni{sub 2}TeO{sub 6} and Na{sub 2}Co{sub 2}TeO{sub 6} is suppressed by zinc substitution. The color of the obtained compositions varies from pink, to light green and white when M=Co, Ni, Zn, respectively. - Graphical abstract: The comparison between the structure of Na{sub 2}Ni{sub 2}TeO{sub 6} (left) and Na{sub 2}M{sub 2}TeO{sub 6} (M=Co, Zn) (right) evidences the stacking difference with distinct atom sequences along the hexagonal c-axis. Highlights: Black-Right-Pointing-Pointer Solid solutions between lamellar phases Na{sub 2}M{sub 2}TeO{sub 6} (M=Co, Ni, Zn) are investigated. Black-Right-Pointing-Pointer A M{sup 2+}/X{sup 6+} honeycomb ordering characterized all the compositions. Black-Right-Pointing-Pointer A structural transition is shown when Ni is replaced by Co or Zn. Black-Right-Pointing-Pointer The low-temperature AFM ordering of Na{sub 2}Ni{sub 2}TeO{sub 6} and Na{sub 2}Co{sub 2}TeO{sub 6} is suppressed by zinc substitution. Black-Right-Pointing-Pointer Color changes from pink to light green and white when M=Co, Ni, Zn, respectively.« less

Application of B{sub 12}N{sub 12} and B{sub 12}P{sub 12} as two fullerene-like semiconductors for adsorption of halomethane: Density functional theory study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rad, Ali Shokuhi, E-mail: a.shokuhi@gmail.com

We examined and discussed the interaction of two halomethanes (mono-chloromethane (MCM), and mono-fluoromethane (MFM)) with B{sub 12}N{sub 12} and B{sub 12}P{sub 12} fullerene-like nanocages as semiconductor based on density functional theory (DFT). We calculated adsorption energies and followed the changes in the electronic structure of semiconductors upon adsorption of MCM and MFM. We found that the adsorption on the B{sub 12}N{sub 12} nano-cluster is energetically more favorable compared to B{sub 12}P{sub 12} nano-cluster. Also for both systems we found higher values of adsorption energy for MFM than for MCM. We found that upon adsorption of above-mentioned species on these twomore » fullerene-like semiconductors, the HOMO–LUMO distributions and also the gap energy for each system did not change significantly, which correspond to the physisorption process. As a result, B{sub 12}N{sub 12} is a more appropriate nano-cluster to be used as a selective sensor for halomethanes, especially for MFM.« less

Fast dynamic electron transfer along infinite anion-cation chains in technetium and rhenium acido clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antipov, B.G.; Kryuchkov, S.V.; Grigor`ev, M.S.

1995-09-01

New technetium and rhenium compounds with ferricenium cations - [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 3}[Tc{sub 6}I{sub 14}], [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 3}[Tc{sub 6}Cl{sub 14}], [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 2}[Tc{sub 8}Br{sub 14}], and [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 2}[Re{sub 2}Br{sub 8}] - are synthesized and identified. The compounds are characterized by the methods of static magnetic susceptibility and differential scanning calorimetry; solid-state conductivity measurements; and IR, EPR, {sup 57}Fe Moessbauer, and X-ray photoelectron spectroscopic data. These data are compared with the physicochemical characteristics of ferricenium pertechnetate and hexachlorotechnetate, as well as of a number of reference technetium and rhenium compounds containing the samemore » anions but different cations. The structure of [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 3}[Tc{sub 6}I{sub 14}] is determined by X-ray diffraction analysis of a single crystal [space group P6/m, a = 15.34(2), c = 12.70(1) {angstrom}]. The structures of the remaining compounds were confirmed by comparing their spectroscopic properties with corresponding properties of compounds with known composition and structure. None of the compounds with ferricenium cations exhibit covalent or other localized bonds between anions and cations. However, the physicochemical properties of these compounds indicate the occurrence of a fast dynamic electron transfer along infinite anion-cation chains. Compounds [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 3}[Tc{sub 6}Cl{sub 14}] and [Fe(C{sub 5}H{sub 5}){sub 2}]{sub 2}[Tc{sub 8}Br{sub 14}] were found to exhibit a new phenomenon of X-ray-induced low-temper ature high-energy electron emission.« less

Leaching characteristics of calcium-based compounds in MSWI Residues: From the viewpoint of clogging risk

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xia, Yi; Institute of Waste Treatment and Reclamation, Tongji University, Shanghai 200092; Zhang, Hua, E-mail: zhanghua_tj@tongji.edu.cn

Highlights: • The leaching behavior of Ca-based compounds commonly in MSWI residues was studied. • pH is the crucial factor for calcium leaching process. • CaCO{sub 3} was the most sensitive to leaching temperature and Ca{sub 3}(PO{sub 4}){sub 2} was the least. • Ca leaching of MSWIBA and SAPCR attributed to CaCO{sub 3} and Ca{sub 3}(PO{sub 4}){sub 2} respectively. • Potential clogging ability of MSWI residues leachate in open air was calculated. - Abstract: Leachate collection system (LCS) clogging caused by calcium precipitation would be disadvantageous to landfill stability and operation. Meanwhile, calcium-based compounds are the main constituents in bothmore » municipal solid waste incineration bottom ash (MSWIBA) and stabilized air pollution control residues (SAPCR), which would increase the risk of LCS clogging once these calcium-rich residues were disposed in landfills. The leaching behaviors of calcium from the four compounds and municipal solid waste incineration (MSWI) residues were studied, and the influencing factors on leaching were discussed. The results showed that pH was the crucial factor in the calcium leaching process. CaCO{sub 3} and CaSiO{sub 3} began leaching when the leachate pH decreased to less than 7 and 10, respectively, while Ca{sub 3}(PO{sub 4}){sub 2} leached at pH < 12. CaSO{sub 4} could hardly dissolve in the experimental conditions. Moreover, the sequence of the leaching rate for the different calcium-based compounds is as follows: CaSiO{sub 3} > Ca{sub 3}(PO{sub 4}){sub 2} > CaCO{sub 3}. The calcium leaching from the MSWIBA and SAPCR separately started from pH < 7 and pH < 12, resulting from CaCO{sub 3} and Ca{sub 3}(PO{sub 4}){sub 2} leaching respectively, which was proven by the X-ray diffraction results. Based on the leaching characteristics of the different calcium compounds and the mineral phase of calcium in the incineration residues, simulated computation of their clogging potential was conducted, providing the theoretical basis for the risk assessment pertaining to LCS clogging in landfills.« less

Electronic structure and dissociation curves for the ground states of Tl/sub 2/ and Tl/sub 2//sup +/ from relativistic effective potential calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christiansen, P.A.; Pitzer, K.S.

The dissociation curves for the ground states of Tl/sub 2/ and Tl/sub 2//sup +/ were computed using a generalization of the molecular relativistic ..omega..--..omega.. coupling formalism of Lee, Ermler, and Pitzer. Relativistic effects, as represented by the Dirac equation, were introduced using effective potentials generated from atomic Dirac--nFock wave functions using a generalization of the improved effective potential formulation of Christiansen, Lee, and Pitzer. Our calculations show that the ground state of Tl/sub 2//sup +/ is 1/2/sub g/ with computed D/sub e/ and R/sub e/ values of 0.58 eV and 3.84 A. For Tl/sub 2/ we find that the groundmore » state is 0/sub u//sup -/ but the 0/sub g//sup +/ and the 1/sub u/ states are only slightly higher in energy; the potential curves for these states are repulsive to about 3.5 A and then essentially flat beyond that radius. While corrections for correlation will increase D/sub e/ somewhat, Tl/sub 2/ is only weakly bound in any of these states which dissociate to normal atoms. The cause is undoubtedly related to the large spin-orbit splitting between the 6p/sub 1/2/ and 6p/sub 3/2/ thallium spinors.« less

Structural, magnetic, magneto-caloric and Mössbauer spectral study of Tb{sub 2}Fe{sub 17} compound synthesized by arc melting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Charfeddine, S.; LVMU, Centre National de Recherches en Sciences des Matériaux, Technopole de Borj-Cédria, BP 73 Soliman 8027; Zehani, K.

We have synthesized the intermetallic Tb{sub 2}Fe{sub 17} compound in hexagonal crystal structure by arc-melting without annealing. X-ray diffraction pattern has been refined by Rietveld method. The crystal structure is hexagonal with P6{sub 3}/mmc space group (Th{sub 2}Ni{sub 17}-type). The Mössbauer spectrum of Tb{sub 2}Fe{sub 17} compound has been analyzed with seven magnetic sextets assigned to the inequivalent crystallographic sites. The temperature dependence of magnetization data revealed that Tb{sub 2}Fe{sub 17} exhibits a second-order ferromagnetic to paramagnetic phase transition in the vicinity of Curie temperature (T{sub C}=412 K). The relative cooling power around the magnetic transition and the Arrott plotsmore » are also reported. - Graphical abstract: A 3D surface showing the temperature and applied magnetic field dependencies of the magnetization for Tb{sub 2}Fe{sub 17} compound (left). Rietveld analysis of the XRD pattern (right). Crystal structure for the hexagonal P6{sub 3}/mmc Tb{sub 2}Fe{sub 17} (bottom). Display Omitted - Highlights: • Tb{sub 2}Fe{sub 17} single-phase synthesized by simple arc-melting without any heat treatment. • The crystal structure is hexagonal with P6{sub 3}/mmc space group. • The magnetic entropy change of the sample was determined by Maxwell relation. • Hyperfine parameters, magnetic and magnetocaloric properties were studied.« less

Glass transition and viscosity of P/sub 2/O/sub 5/

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, S.W.; Angell, C.A.

1986-12-04

The calorimetric glass transition temperature T/sub g/ for pure anhydrous P/sub 2/O/sub 5/ melted in sealed SiO/sub 2/ ampules at 1000 /sup 0/C has been obtained directly for the first time with differential scanning calorimetry, and the increase in heat capacity at T/sub g/ has been determined. T/sub g/ measured in this way is 57 K higher than the value quoted in the literature, which is probably based on an Arrhenius law extrapolation of viscosity data to eta = 10/sup 13/ P. Combining the high-temperature viscosity data with the common observation that, for oxide glasses, eta = 10/sup 12/ Pmore » at the DSC T/sub g/, the authors find that the P/sub 2/O/sub 5/ viscosity obeys an Arrhenius law over at least 6 decades of eta. Furthermore, the intercept at 1/T = 0 coincides with the common point of T/sub g/ - reduced viscosity plots for a wide variety of liquids recently used in establishing the strong vs. fragile classification of glass-forming liquids. On this basis, P/sub 2/O/sub 5/ behaves as the archetypal strong liquid. However, the value of C/sub p/(liquid)/C/sub p/(glass) at T/sub g/, 1.27, is larger than expected on this basis since other strong liquids show smaller values, e.g., GeO/sub 2/ (1.09) and BeF/sub 2/ (no ..delta..C/sub p/ detected). The dependence of T/sub g/ on heating rate has been determined and shows that enthalpy relaxation in the transition region has, within error, the same activation energy (43.9 kcal/mol) as for viscous flow.« less

Synthesis of [1-.sup.13C]pyruvic acid], [2-.sup.13C]pyruvic acid], [3-.sup.13C]pyruvic acid] and combinations thereof

DOEpatents

Martinez, Rodolfo A. , Unkefer; Clifford J. , Alvarez; Marc, A [Santa Fe, NM

2012-06-12

The present invention is directed to the labeled compounds, ##STR00001## wherein C* is each either .sup.13C and .sup.12C where at least one C* is .sup.13C, each hydrogen of the methylene group is hydrogen or deuterium, the methyl group includes either zero or three deuterium atoms, Q is sulfide, sulfinyl, or sulfone, Z is an aryl group such as 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, or a phenyl group ##STR00002## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently either hydrogen, a C.sub.1-C.sub.4 lower alkyl, a halogen, and an amino group such as NH.sub.2, NHR and NRR' where R and R' are each independently either a C.sub.1-C.sub.4 lower alkyl, a phenyl, and an alkoxy group, and the methyl group can include either zero or three deuterium atoms. The present invention is also directed to the labeled compounds ##STR00003##

Precursor dependent nucleation and growth of ruthenium films during chemical vapor deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liao, Wen; Ekerdt, John G., E-mail: ekerdt@utexas.edu

2016-07-15

Nucleation and film growth characteristics are reported during chemical vapor deposition of Ru on SiO{sub 2} using triruthenium dodecacarbonyl [Ru{sub 3}(CO){sub 12}] and ruthenium bis(di-t-butylacetamidinate) dicarbonyl [Ru({sup t}Bu-Me-amd){sub 2}(CO){sub 2}]. Films grown from Ru{sub 3}(CO){sub 12} follow the three dimensional (3D) Volmer–Weber growth mode. In contrast, films grown from Ru({sup t}Bu-Me-amd){sub 2}(CO){sub 2} follow the pseudo-layer-by-layer growth mode with two dimensional wetting layer islands forming before 3D particle growth is observed on the islands. A relationship between free isolated hydroxyl [(Si-OH){sub i}] group density and Ru nucleation density is found for Ru{sub 3}(CO){sub 12} and is associated with (Si-OH){sub i}more » acting as the reaction sites for activation of Ru{sub 3}(CO){sub 12} and in turn generating an adjustable adatom concentration. Carbon monoxide and ammonia addition to the gas phase during film growth from Ru({sup t}Bu-Me-amd){sub 2}(CO){sub 2} lead to smoother films by inducing surface reconstructions during the 3D phase of pseudo-layer-by-layer growth; these gases also lead to films with lower resistivity and lower crystalline character.« less

Constitution of green rust and its significance to the corrosion of steel in Portland cement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sagoe-Crentsil, K.K.; Glasser, F.P.

1993-06-01

Studies of the corrosion of pure iron showed green rust, approximately Fe[sub 4][sup 2+]Fe[sub 2][sup 3+] (OH)[sub 12](Cl,OH)[sub 2], was a stable corrosion product at high pH and low E[sub h] in the presence of chloride. The structure, constitution, preparation, and characterization of green rust was reviewed. A diagram relevant to the corrosion of iron in cement, constructed for pH 12, showed stability fields of green rust, [alpha],[delta] FeO(OH), and [beta]FeO(OH,Cl). Overall implications of chloride to the corrosion process were investigated.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pangaro, L.; Burman, K.D.; Wartofsky, L.

The present report describes a RIA for 3,5-diiodothyronine (3,5T/sub 2/) which uses inner ring-labeled 3,5-(/sup 125/I)T/sub 2/ as the ligand and has a lower limit of detectability of 0.5 ng/dl. Cross-reaction was 0.14% with T/sub 3/, less than 0.001% with T/sub 4/, 1.2% with 3,3',5-triiodothyroacetic acid, and 6.1% with 3,5-diiodothyroacetic acid. No cross-reaction was detectable for iodothyronines within their physiological ranges. Intraassay variation ranged from 2.2 to 7.8%, and interassay variation ranged from 12.7 to 14%. The mean (+-SE) serum 3.5T/sub 2/ concentration in 70 normal subjects was 4.3 +- 0.2 ng/dl. The mean (+-SE) 3.5T/sub 2/ in 14 hyperthyroidmore » patients was increased to 18.4 +- 2.3 ng/dl (P < 0.001), and all but 1 patient had an elevated level. In 10 hypothyroid patients the mean (+-SE) 3,5T/sub 2/ level was decreased to 1.4 +- 0.3 ng/dl (P < 0.001). In 4 patients, levels overlapped with the normal range. In 4 hypothyroid subjects treated with L-T/sub 1/, 3,5T/sub 2/ levels were normal, suggesting that the majority of 3,5T/sub 2/ originates from extrathyroidal conversion from T/sub 3/. Studies in fasting obese subjects demonstrated that serum 3,5T/sub 2/ (mean +- SE) levels fell from 3.4 +- 0.3 to 2.5 +- 0.7 ng/dl during fasting. This fall was significant (P < 0.001) and in parallel with the fall in T/sub 3/ levels of 182 +- 20 to 126 +- 12 ng/dl. In fasting subjects given 100 ..mu..g oral L-T/sub 3//day T/sub 3/ levels rose from 138 +- 11 to 362 +- 26 ng/dl. 3,5T/sub 2/ levels (corrected for cross-reaction and for contamination of oral T/sub 3/ with 3,5T/sub 2/) rose from 2.2 +- 0.7 to 6.4 +- 1.0 ng/dl. In fasting subjects given 25 ..mu..g oral L-T/sub 3//day, T/sub 3/ levels fell from 165 +- 5.1 to 139 +- 6.9 ng/dl. Corrected 3,5T/sub 2/ levels changed from 3.7 +- 0.4 to 2.5 +- 0.3 ng/dl. Neither change were significant.« less

Expression, purification, crystallization and preliminary X-ray diffraction analysis of the VP8* sialic acid-binding domain of porcine rotavirus strain OSU

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yang-De, E-mail: zhangyd1960@yahoo.com.cn; Li, Hao; Liu, Hui

2007-02-01

Porcine rotavirus strain OSU VP8* domain has been expressed, purified and crystallized. X-ray diffraction data from different crystal forms of the VP8* domain have been collected to 2.65 and 2.2 Å resolution, respectively. The rotavirus outer capsid spike protein VP4 is utilized in the process of rotavirus attachment to and membrane penetration of host cells. VP4 is cleaved by trypsin into two domains: VP8* and VP5*. The VP8* domain is implicated in initial interaction with sialic acid-containing cell-surface carbohydrates and triggers subsequent virus invasion. The VP8* domain from porcine OSU rotavirus was cloned and expressed in Escherichia coli. Different crystalmore » forms (orthorhombic P2{sub 1}2{sub 1}2{sub 1} and tetragonal P4{sub 1}2{sub 1}2) were harvested from two distinct crystallization conditions. Diffraction data have been collected to 2.65 and 2.2 Å resolution and the VP8*{sub 65–224} structure was determined by molecular replacement.« less

Effect of Hindlimb Unloading on Rat Soleus Fiber Force, Stiffness, and Calcium Sensitivity

NASA Technical Reports Server (NTRS)

McDonald Kerry S.; Fitts, Robert H.

1995-01-01

The purpose of this study was to examine the time course of change in soleus muscle fiber peak force (N), tension (P(sub 0), kN/sq m), elastic modulus (E(sub 0)), and force-pCa and stiffness - pCa relationships. After 1, 2, or 3 wk of Hindlimb Unloading (HU), single fibers were isolated and placed between a motor arm and a transducer, and fiber diameter, peak absolute force, P(sub 0), E(sub 0), and force-pCa and stiffness-pca relationships were characterized. One week of HU resulted in a significant reduction in fiber diameter (68 +/- 2 vs. 57 +/- 1 micrometer), force (3.59 +/- 0.15 vs. 2.19 +/- 0.12 x 10(exp -4) N), P(sub 0) (102 +/- 4 vs. 85 +/- 2 kN/sq m), and E(sub 0) (1.96 +/- 0.12 vs. 1.37 +/- 0.13 X 10(exp 7) N/sq m) and 2 wk of HU caused a further decline in fiber diameter (45 +/- 1 micrometer), force (1.31 +/- 0.06 x 10(exp -4) N), and E(sub 0)(0.96 +/- 0.09 x 10(exp 7) N/sq m). Although the mean fiber diameter and absolute force continued to decline through 3 wk of HU, P(sub 0) recovered to values not significantly different from control. The P(sub 0)/E(sub 0) ratio was significantly increased after 1 (5.5 +/- 0.3 to 7.1 +/- 0.6), 2, and 3 wk of HU, and the 2-wk (9.5 +/- 0.4) and 3-wk (9.4 +/- 0.8) values were significantly greater than the 1-wk values. The force-pCa and stiffness-pCa curves were shifted right- ward after 1, 2, and 3 wk of HU. At 1 wk of HU, the Ca(2+) sensitivity of isometric force, assessed by Ca(2+) concentration required for half-maximal force, was increased from the control value of 1.83 +/- 0.12 to 2.30 +/- 0.10 micrometers. In conclusion, after HU, the decrease in soleus fiber P(sub 0) can be explained by a reduction in the number of myofibrillar cross bridges per cross-sectional area. Our working hypothesis is that the loss of contractile protein reduces the number of cross bridges per cross-sectional area and increases the filament lattice spacing. The increased spacing reduces cross-bridge force and stiffness, but P(sub 0)/E(sub 0) increases because of a quantitatively greater effect on stiffness.

Stellar reaction rate for {sup 22}Mg+p->{sup 23}Al from the asymptotic normalization coefficient in the mirror nuclear system {sup 22}Ne+n->{sup 23}Ne

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Abdullah, T.; Physics Department, Hashemite University, Zarqa 13115; Carstoiu, F.

2010-03-15

The production of {sup 22}Na in ONe novae can be influenced by the {sup 22}Mg(p,gamma){sup 23}Al reaction. To investigate this reaction rate at stellar energies, we have determined the asymptotic normalization coefficient (ANC) for {sup 22}Mg+p->{sup 23}Al through measurements of the ANCs in the mirror nuclear system {sup 22}Ne+n->{sup 23}Ne. The peripheral neutron-transfer reactions {sup 13}C({sup 12}C,{sup 13}C){sup 12}C and {sup 13}C({sup 22}Ne,{sup 23}Ne){sup 12}C were studied. The identical entrance and exit channels of the first reaction make it possible to extract independently the ground-state ANC in {sup 13}C. Our experiment gives C{sub p{sub 1/2}}{sup 2}({sup 13}C)=2.24+-0.11 fm{sup -1}, whichmore » agrees with the value obtained from several previous measurements. The weighted average for all the obtained C{sub p{sub 1/2}}{sup 2} is 2.31+-0.08 fm{sup -1}. This value is adopted to be used in obtaining the ANCs in {sup 23}Ne. The differential cross sections for the reaction {sup 13}C({sup 22}Ne,{sup 23}Ne){sup 12}C leading to the J{sup {pi}}=5/2{sup +} and 1/2{sup +} states in {sup 23}Ne have been measured at 12 MeV/u. Optical model parameters for use in the DWBA calculations were obtained from measurements of the elastic scatterings {sup 22}Ne+{sup 13}C and {sup 22}Ne+{sup 12}C. The extracted ANC for the ground state in {sup 23}Ne, C{sub d{sub 5/2}}{sup 2}=0.86+-0.08+-0.12 fm{sup -1}, is converted to its corresponding value in {sup 23}Al using mirror symmetry to give C{sub d{sub 5/2}}{sup 2}({sup 23}Al)=(4.63+-0.77)x10{sup 3} fm{sup -1}. The astrophysical S factor S(0) for the {sup 22}Mg(p,gamma) reaction was determined to be 0.96+-0.11 keV b. The consequences for nuclear astrophysics are discussed.« less

Crystal structure and genesis of the hydrated analog of rastsvetaevite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rastsvetaeva, R. K., E-mail: ras@ns.crys.ras.ru; Aksenov, S. M.; Rozenberg, K. A.

2015-11-15

The crystal structure of the hydrated analog of the mineral rastsvetaevite (tentatively called “hydrorastsvetaevite”), which was found by A.P. Khomyakov in ultraagpaitic pegmatites at the Rasvumchorr Mountain of the Khibiny alkaline massif (Kola Peninsula), has been determined by single crystal X-ray diffraction. The trigonal unit-cell parameters are as follows: a = 14.2812(2) Å, c = 60.533(5) Å, V = 10691.54(3) Å{sup 3}, sp. gr. R3m. The structure was refined to R = 5.9% in the isotropic and anisotropic approximation of atomic displacement parameters based on 2068 ref lections with |F| > 3σ(F). “Hydrorastsvetaevite” is on the whole analogous to othermore » 24-layer representatives of the eudialyte group (called “megaeudialytes”), but is characterized by a high potassium content and is distinguished from other potassium-rich minerals (rastsvetaevite, davinciite, and andrianovite) by low sodium and alkaline-earth metal content, as well as by a high degree of hydration accompanied by the insertion of H{sub 3}O groups, which partially or completely replace large cations. The idealized formula of “hydrorastsvetaevite” (Z = 3) is (Na{sub 11}(H{sub 3}O){sub 11}K{sub 6}(H{sub 2}O){sub 1.5}Sr)Ca{sub 12}Fe{sub 3}Na{sub 2}MnZr{sub 6}Si{sub 52}O{sub 144}(OH){sub 4.5}C{sub l3.5}(H{sub 2}O){sub 0.5}. In alkaline pegmatites, “hydrorastsvetaevite” occurs as a secondary mineral developed from the original rastsvetaevite through decationation and hydration. The characteristic features of the genesis of eudialyte-group minerals containing potassium as a species-forming cation are discussed in terms of the concept of transformational mineral species.an]Mis||Original Russian Text © R.K. Rastsvetaeva, S.M. Aksenov, K.A. Rozenberg, 2015, published in Kristallografiya, 2015, Vol. 60, No. 6, pp. 897–905.« less

Synthesis, structure and optical properties of two isotypic crystals, Na{sub 3}MO{sub 4}Cl (M=W, Mo)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Shujuan; Bai, Chunyan; Zhang, Bingbing

Two isotypic compounds, Na{sub 3}MO{sub 4}Cl (M = W, Mo) have been obtained from the high temperature solution, and their structures were determined by single-crystal X-ray diffraction. Both of them crystallize in the space group P4/nmm of tetragonal system with the unit cells: a=7.5181(15), c=5.360(2) for Na{sub 3}WO{sub 4}Cl and a=7.4942(12), c=5.3409(18) for Na{sub 3}MoO{sub 4}Cl. The structure exhibits a 3D network built up by the ClNa{sub 6} groups, and the MO{sub 4} groups reside in the tunnels of the 3D network. The structural similarities and differences between Na{sub 3}MO{sub 4}Cl (M=W, Mo) and Sr{sub 3}MO{sub 4}F (M=Al, Ga) havemore » been discussed. Meanwhile, detailed structure comparison analyses between Na{sub 3}MO{sub 4}Cl (M=W, Mo) and Na{sub 3}MO{sub 4}F (M=W, Mo) indicate that the different connection modes of ClNa{sub 6} and FNa{sub 6} make Na{sub 3}MO{sub 4}Cl and Na{sub 3}MO{sub 4}F crystallize in different structures. The IR spectra were used to verify the validity of the structure. The diffuse reflectance spectra show that the UV absorption edges are about 249 nm (4.99 eV) and 265 nm (4.69 eV) for Na{sub 3}WO{sub 4}Cl and Na{sub 3}MoO{sub 4}Cl, respectively. In addition, the first-principles theoretical studies are also carried out to aid the understanding of electronic structures and linear optical properties. - Graphical abstract: Two isotypic compounds, Na{sub 3}MO{sub 4}Cl (M=W, Mo) have been obtained from the high temperature solution. Both of them crystallize in the space group P4/nmm of tetragonal system. The structure exhibits a 3D network built up by the ClNa{sub 6} groups, and the MO{sub 4} groups reside in the tunnels of the 3D network. - Highlights: • Structure and properties of Na{sub 3}MO{sub 4}Cl (M=W, Mo) are reported for the first time. • They show a 3D network built by ClNa{sub 6}, and WO{sub 4} lies in the tunnels of the network. • IR spectra were used to verify the validity of the structure. • Band structures and density of states have been calculated.« less

Synthesis and an X-ray diffraction study of Rb{sub 2}[(UO{sub 2}){sub 2}(C{sub 2}O{sub 4}){sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serezhkina, L. B., E-mail: Lserezh@ssu.samara.ru; Peresypkina, E. V.; Neklyudova, N. A.

2010-09-15

The synthesis and X-ray diffraction study of compound Rb{sub 2}[(UO{sub 2}){sub 2}(C{sub 2}O{sub 4}){sub 3}], which crystallizes in the monoclinic crystal system, are performed. The unit cell parameters are as follows: a = 7.9996(6) A, b = 8.8259(8) A, c = 11.3220(7) A, {beta} = 105.394(2){sup o}, and V = 770.7(1) A{sup 3}; space group P2{sub 1}/n, Z = 2, and R{sub 1} = 0.0271. [(UO{sub 2}){sub 2}(C{sub 2}O{sub 4}){sub 3}]{sup 2-} layers belonging to the AK{sub 0.5}{sup 02}T{sup 11} crystal chemical group of uranyl complexes (A = UO{sub 2}{sup 2+}, K{sup 02} = C{sub 2}O{sub 4}{sup 2-}, and T{supmore » 11} = C{sub 2}O{sub 4}{sup 2-}) are uranium-containing structural units of the crystals. The layers are connected with outer-sphere rubidium cations by electrostatic interactions.« less

Uridine adenosine tetraphosphate (Up{sub 4}A) is a strong inductor of smooth muscle cell migration via activation of the P2Y{sub 2} receptor and cross-communication to the PDGF receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiedon, Annette; Toelle, Markus; Bastine, Joschika

2012-01-20

Highlights: Black-Right-Pointing-Pointer Up{sub 4}A induces VSMC migration. Black-Right-Pointing-Pointer VSMC migration towards Up{sub 4}A involves P2Y{sub 2} activation. Black-Right-Pointing-Pointer Up{sub 4}A-induced VSMC migration is OPN-dependent. Black-Right-Pointing-Pointer Activation of ERK1/2 pathway is necessary for VSMC migration towards Up{sub 4}A. Black-Right-Pointing-Pointer Up{sub 4}A-directed VSMC migration cross-communicates with the PDGFR. -- Abstract: The recently discovered dinucleotide uridine adenosine tetraphosphate (Up{sub 4}A) was found in human plasma and characterized as endothelium-derived vasoconstrictive factor (EDCF). A further study revealed a positive correlation between Up{sub 4}A and vascular smooth muscle cell (VSMC) proliferation. Due to the dominant role of migration in the formation of atherosclerotic lesions ourmore » aim was to investigate the migration stimulating potential of Up{sub 4}A. Indeed, we found a strong chemoattractant effect of Up{sub 4}A on VSMC by using a modified Boyden chamber. This migration dramatically depends on osteopontin secretion (OPN) revealed by the reduction of the migration signal down to 23% during simultaneous incubation with an OPN-blocking antibody. Due to inhibitory patterns using specific and unspecific purinoreceptor inhibitors, Up{sub 4}A mediates it's migratory signal mainly via the P2Y{sub 2}. The signaling behind the receptor was investigated with luminex technique and revealed an activation of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) pathway. By use of the specific PDGF receptor (PDGFR) inhibitor AG1296 and siRNA technique against PDGFR-{beta} we found a strongly reduced migration signal after Up{sub 4}A stimulation in the PDGFR-{beta} knockdown cells compared to control cells. In this study, we present substantiate data that Up{sub 4}A exhibits migration stimulating potential probably involving the signaling cascade of MEK1 and ERK1/2 as well as the matrix protein OPN. We further suggest that the initiation of the migration process occurs predominant through direct activation of the P2Y{sub 2} by Up{sub 4}A and via transactivation of the PDGFR.« less

Complementarity and path distinguishability: Some recent results concerning photon pairs

NASA Technical Reports Server (NTRS)

Shimony, Abner; Jaeger, Gregg

1994-01-01

Two results concerning photon pairs, one previously reported and one new, are summarized. It was previously shown that if the two photons are prepared in a quantum state formed from bar-A and bar-A' for photon 1 and bar-B and bar-B' for photon 2, then both one- and two-particle interferometry can be studied. If upsilon(sub i) is the visibility of one-photon interference fringes (i = 1,2) and upsilon(sub 12) is the visibility of two-photon fringes (a concept which we explicitly define), then upsilon(sub i) squared + upsilon(sub 12) squared is less than or equal to 1. The second result concerns the distinguishability of the paths of photon 2, using the known 2-photon state. A proposed measure E for path distinguishability is based upon finding an optimum strategy for betting on the outcome of a path measurement. Mandel has also proposed a measure of distinguishability P(sub D), defined in terms of the density operator rho of photon 2. We show that E is greater than or equal to P(sub D) and that upsilon(sub 2) = (1 - E(exp 2))exp 1/2.

Preliminary crystallographic analysis of mouse Elf3 C-terminal DNA-binding domain in complex with type II TGF-[beta] receptor promoter DNA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agarkar, Vinod B.; Babayeva, Nigar D.; Rizzino, Angie

2010-10-08

Ets proteins are transcription factors that activate or repress the expression of genes that are involved in various biological processes, including cellular proliferation, differentiation, development, transformation and apoptosis. Like other Ets-family members, Elf3 functions as a sequence-specific DNA-binding transcriptional factor. A mouse Elf3 C-terminal fragment (amino-acid residues 269-371) containing the DNA-binding domain has been crystallized in complex with mouse type II TGF-{beta} receptor promoter (TR-II) DNA. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 42.66, b = 52, c = 99.78 {angstrom}, and diffracted to a resolution of 2.2 {angstrom}.

Phosphors for LED lamps

DOEpatents

Murphy, James Edward; Manepalli, Satya Kishore; Kumar, Prasanth Nammalwar

2013-08-13

A phosphor, a phosphor blend including the phosphor, a phosphor prepared by a process, and a lighting apparatus including the phosphor blend are disclosed. The phosphor has the formula (Ca.sub.1-p-qCe.sub.pK.sub.q).sub.xSc.sub.y(Si.sub.1-rGa.sub.r).sub.zO.su- b.12+.delta. or derived from a process followed using disclosed amounts of reactants. In the formula, (0

Study of np{sup 2}P{sub 1/2,3/2} Rydberg series of AlI by the method of laser stepwise excitation and ionization by electric field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kasimov, A.K.; Tursunov, A.T.; Tukhlibaev, O.

Frequencies of the 4s{sup 2}S{sub 1/2}-np{sup 2}P{sub 1/2, 3/2} transitions are measured and the energies of high-lying P states, as well as the ionization energy of aluminum atoms, are determined by the method of two-step laser excitation and ionization of excited atoms of AlI by an electric field. 4 refs., 3 figs., 1 tab.

Kinetics of the Reactions of O((sup 3)P) and Cl((sup 2)P) with HBr and Br2

NASA Technical Reports Server (NTRS)

Nicovich, J. M.; Wine, P. H.

1997-01-01

A laser flash photolysis-resonance fluorescence technique has been employed to study the kinetics of reactions (1)-(4) as a function of temperature. (1) O((sup 3)P) + Br2 yields BrO + Br((sup 2)P(sub 3/2)) at 255-350 K; (2) Cl((sup 2)P) + Br2 yields BrCl + Br((sup 2)P(sub 3/2)) at 298-401 K; (3) O((sup 3)P) + HBr yields OH + Br((sup 2)P(sub J)) at 250-402 K; (4) Cl((sup 2)P) + HBr yields HCl + Br((sup 2)P(sub J)) at 257-404 K. In all cases, the concentration of the excess reagent, i.e, HBr or Br2, was measured in situ in the slow flow system by UV-visible photometry. Heterogeneous dark reactions between XBr (X equals H or Br) and the photolytic precursors for Cl((sup 2)P) and O((sup 3)P) (Cl2 and O3, respectively) were avoided by injecting minimal amounts of precursor into the reaction mixture immediately upstream from the reaction zone. The following Arrhenius expressions summarize our results (errors are 2 sigma and represent precision only, units are cu cm/(molecule.s): k(sub 1) = (1.76 +/- 0.80) x 10(exp -11 exp[(40 +/- 100)/T]; k(sub 2) = (2.40 +/- 1.25) x 12(exp -10) exp[-(144 +/- 176)/T]; k(sub 3) = (5.11 +/- 2.82) x 10(exp -12) exp[-(1450 +/- 160)/T]; k(sub 4) = (2.25 +/- 0.56) x 10(exp -11) exp[-(400 +/- 80)/T]. The consistency (or lack thereof) of our results with those reported in previous kinetics and dynamics studies of reactions (1)-(4) is discussed.

Phase equilibria in the NaF-CdO-NaPO{sub 3} system at 873 K and crystal structure and physico-chemical characterizations of the new Na{sub 2}CdPO{sub 4}F fluorophosphate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aboussatar, Mohamed; Laboratoire de Physico-Chimie de l’État Solide, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax; Mbarek, Aïcha

Isothermal sections of the diagram representing phase relationships in the NaF-CdO-NaPO{sub 3} system have been investigated by solid state reactions and powder X-ray diffraction. This phase diagram investigation confirms the polymorphism of the NaCdPO{sub 4} side component and the structure of the ß high temperature polymorph (orthorhombic, space group Pnma and unit cell parameters a=9.3118(2), b=7.0459(1), c=5.1849(1) Å has been refined. A new fluorophosphate, Na{sub 2}CdPO{sub 4}F, has been discovered and its crystal structure determined and refined from powder X-ray diffraction data. It exhibits a new 3D structure with orthorhombic symmetry, space group Pnma and unit cell parameters a=5.3731(1), b=6.8530(1),more » c=12.2691(2) Å. The structure is closely related to those of the high temperature polymorph of the nacaphite Na{sub 2}CaPO{sub 4}F and the fluorosilicate Ca{sub 2}NaSiO{sub 4}F but differs essentially in the cationic repartition since the structure is fully ordered with one Na site (8d) and one Cd site (4c). Relationships with other Na{sub 2}M{sup II}PO{sub 4}F (M{sup II}=Mg, Ca, Mn, Fe, Co, Ni) have been examined and the crystal-chemical and topographical analysis of these fluorophosphates is briefly reviewed. IR, Raman, optical and {sup 19}F, {sup 23}Na, {sup 31}P MAS NMR characterizations of Na{sub 2}CdPO{sub 4}F have been investigated. - Graphical abstract: The structure of the compound Na{sub 2}CdPO{sub 4}F, discovered during the study of the phase relationships in the NaF-CdO-NaPO{sub 3} system, has been determined and compared with other Na{sub 2}M{sup II}PO{sub 4}F fluorophosphates. - Highlights: • XRD analysis of the isothermal section of the NaF-CdO-NaPO{sub 3} system at 923 K. • Rietveld refinement of the high temperature polymorph β-NaCdPO{sub 4}. • Crystal structure of the new Na{sub 2}CdPO{sub 4}F fluorophosphate determined from powder XRD. • Crystal structure - composition relationships of Na{sub 2}M{sup II}PO{sub 4}F compounds are reviewed. • IR, Raman, optical and {sup 19}F, {sup 23}Na, {sup 31}P MAS NMR characterizations of Na{sub 2}CdPO{sub 4}F.« less

The crystal structures of Ni{sub 3+x}Sn{sub 4}Zn and Ni{sub 6+x}Sn{sub 8}Zn and their structural relations to Ni{sub 3+x}Sn{sub 4}, NiSn and Ni{sub 5−δ}ZnSn{sub 4}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmetterer, Clemens, E-mail: clemens.schmetterer@univie.ac.at; Effenberger, Herta Silvia; Rajamohan, Divakar

2016-06-15

The crystal structures of two new compounds were determined from single-crystal X-ray diffraction measurements: Ni{sub 3+x}Sn{sub 4}Zn, (x~1.35, a=7.110(2) Å, b=4.123(1) Å, c=10.346(3) Å, β=90.23(2)°, space group I2/m, Z=2. R1=0.025, wR2=0.059 for 748 unique reflections, 35 variable parameters) and Ni{sub 6+x}Sn{sub 8}Zn, x~1.35 (a=12.379(3) Å, b=4.095(1) Å, c=12.155(3) Å, β=116.25(3)°, space group C2/m, Z=2. R1=0.026, wR2=0.052 for 1346 unique reflections, 60 variable parameters). In addition, a structural refinement was performed for Ni{sub 3+x}Sn{sub 4}, x~0.13 (a=12.264(3) Å, b=4.066(1) Å, c=5.223(2) Å, β=104.85(3)°, space group C2/m, Z=2. R1=0.019, wR2=0.046 for 617 unique reflections, 29 variable parameters). The three compounds show pronouncedmore » similarities among each other as well as to the crystal structures of surrounding binary Ni–Sn and ternary Ni–Sn–Zn compounds. In particular, the two new compounds form a homologous series with Ni{sub 3+x}Sn{sub 4}, x~0.13. They contain “Ni{sub 4}Sn{sub 4}” and “Ni{sub 2}Sn{sub 4}” building blocks which by different interconnection build up the distinct structures. Topological relations with NiSn and Ni{sub 5−δ}Sn{sub 4}Zn, δ~0.25 are evident. - Graphical abstract: Projection of the structure of Ni{sub 6+x}ZnSn{sub 8}, x~1.35 and constituent building blocks. Display Omitted - Highlights: • The crystal structures of Ni{sub 6+x}Sn{sub 8}Zn and Ni{sub 3+x}Sn{sub 4}Zn were determined using single crystal XRD. • Topological relations to Ni–Sn and Ni–Sn–Zn compounds were established and discussed. • Common structural units were identified and their interconnection patterns described.« less

Syntheses, structures and magnetisms of copper(II)–azido coordination compounds with p-substituted benzoates as coligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Cuiyu; Yu, Nan; Bu, Huaitian

2016-01-15

Employing p-substituted benzoates with electron-withdrawing/electron-donating groups as coligands, four copper–azido compounds, [Cu{sub 1.5}(p-NO{sub 2}-benzoate)(N{sub 3}){sub 2}(H{sub 2}O)]{sub n} (1), [Cu(p-NO{sub 2}-benzoate)(N{sub 3})(H{sub 2}O)]{sub n} (2), [Cu(p-OH-benzoate)(N{sub 3})(H{sub 2}O)]{sub n}·nH{sub 2}O (3) and [Cu(p-CH{sub 3}-benzoate)(N{sub 3})]{sub n} (4), have been hydrothermally synthesized and structurally charactierized by single crystal X-ray diffraction. Structural analysis reveals that all compounds are composed of mixed EO-azido and syn–syn carboxylato-bridged Cu-N{sub 3}/COO chains. Compound 1 features the alternating triple-bridged (μ-EO-N{sub 3})(μ-COO)(μ-H{sub 2}O) and the double-bridged (EO-N{sub 3}){sub 2} modes. Both of 2 and 3 display the triple-bridged fashion (μ-EO-N{sub 3})(μ-COO)(μ-H{sub 2}O). While 4 exhibits the double-bridged modemore » (μ-EO-N{sub 3})(μ-COO). Based on hydrogen-bonding interactions, Cu–N{sub 3}/COO chains in 1–3 are further connected to form 3D supramolecular frameworks. As for compound 4, there are not hydrogen-bonding interactions when the p-CH{sub 3} substituted benzoate is employed as coligand. These compounds show intrachain ferromagnetic performance and different bulk properties. Remarkably, 1 features metamagnetism from antiferromagnetism to ferrimagnetism, while 3 reveals long-range ferromagnetic ordering between Cu(II) ions. Magneto-structural correlation has been also investigated. - Graphical abstract: With p-substituted benzoates as coligands, copper–azido compounds were isolated and structrually, magnetically characterized. Magneto-structural correlation has been investigated in detail.« less

Four new chalcohalides, NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br and CsBa{sub 2}SnS{sub 4}Cl: Syntheses, crystal structures and optical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Chao; Feng, Kai; Tu, Heng

Four new chalcohalides, namely NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br, and CsBa{sub 2}SnS{sub 4}Cl, have been synthesized by the conventional high temperature solid-state reactions. They crystallize in three different space groups: space group I4/mcm for NaBa{sub 2}SnS{sub 4}Cl and KBa{sub 2}SnS{sub 4}Cl, Pnma for KBa{sub 2}SnS{sub 4}Br, and P2{sub 1}/c for CsBa{sub 2}SnS{sub 4}Cl. In all four compounds, the X{sup −} halide anions are only connected to six alkali metal or Ba cations, and the Sn atoms are only tetrahedrally enjoined to four S atoms. However, the M–X–Ba pseudo layers and the SnS{sub 4} tetrahedra are arrangedmore » in different ways in the three structural types, which demonstrates the interesting effect of ionic radii on the crystal structures. UV–vis–NIR spectroscopy measurements indicate that NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br, and CsBa{sub 2}SnS{sub 4}Cl have band gaps of 2.28, 2.30, 1.95, and 2.06 eV, respectively. - Graphical abstract: A new series of chalcohalides, NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br and CsBa{sub 2}SnS{sub 4}Cl have been obtained. They present three different space groups: NaBa{sub 2}SnS{sub 4}Cl and KBa{sub 2}SnS{sub 4}Cl in space group I4/mcm, KBa{sub 2}SnS{sub 4}Br in Pnma and CsBa{sub 2}SnS{sub 4}Cl in space group P2{sub 1}/c. UV–vis–NIR spectroscopy measurements indicate that NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br and CsBa{sub 2}SnS{sub 4}Cl have band gaps of 2.28, 2.30 1.95, and 2.06 eV, respectively. - Highlights: • Four new chalcohalides, NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br and CsBa{sub 2}SnS{sub 4}Cl were obtained. • They adopt three different structures owing to different ionic radii and elemental electronegativity. • NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br and CsBa{sub 2}SnS{sub 4}Cl have band gaps of 2.28, 2.30 1.95, and 2.06 eV, respectively.« less

Dependency of anti-ferro-magnetic coupling strength on Ru spacer thickness of [Co/Pd]{sub n}-synthetic-anti-ferro-magnetic layer in perpendicular magnetic-tunnel-junctions fabricated on 12-inch TiN electrode wafer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chae, Kyo-Suk; Samsung Electronics Co., Ltd., San #16 Banwol-dong, Hwasung-City, Gyeonggi-Do 445-701; Shim, Tae-Hun

We investigated the Ru spacer-thickness effect on the anti-ferro-magnetic coupling strength (J{sub ex}) of a [Co/Pd]{sub n}-synthetic-anti-ferro-magnetic layer fabricated with Co{sub 2}Fe{sub 6}B{sub 2}/MgO based perpendicular-magnetic-tunneling-junction spin-valves on 12-in. TiN electrode wafers. J{sub ex} peaked at a certain Ru spacer-thickness: specifically, a J{sub ex} of 0.78 erg/cm{sup 2} at 0.6 nm, satisfying the J{sub ex} criteria for realizing the mass production of terra-bit-level perpendicular-spin-transfer-torque magnetic-random-access-memory. Otherwise, J{sub ex} rapidly degraded when the Ru spacer-thickness was less than or higher than 0.6 nm. As a result, the allowable Ru thickness variation should be controlled less than 0.12 nm to satisfy the J{sub ex} criteria. However,more » the Ru spacer-thickness did not influence the tunneling-magneto-resistance (TMR) and resistance-area (RA) of the perpendicular-magnetic-tunneling-junction (p-MTJ) spin-valves since the Ru spacer in the synthetic-anti-ferro-magnetic layer mainly affects the anti-ferro-magnetic coupling efficiency rather than the crystalline linearity of the Co{sub 2}Fe{sub 6}B{sub 2} free layer/MgO tunneling barrier/Co{sub 2}Fe{sub 6}B{sub 2} pinned layer, although Co{sub 2}Fe{sub 6}B{sub 2}/MgO based p-MTJ spin-valves ex-situ annealed at 275 °C achieved a TMR of ∼70% at a RA of ∼20 Ω μm{sup 2}.« less

(Pentamethylcyclopentadienyl)molybdenum(IV) chloride. Synthesis, structure, and properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abugideiri, F.; Desai, J.U.; Gordon, J.C.

1994-08-17

Three different syntheses of trichloro(pentamethylcyclopentadienyl)molybdenum(IV) are described, I.E. (1) thermal decarbonylation of Cp{sup *}MoCl{sub 3}(CO){sub 2}, (2) reduction of Cp{sup *}MoCl{sub 4}, and (3) chlorination of [Cp{sup *}MoCl{sub 2}]{sub 2}. A fourth route (conproportionation of [Cp{sup *}MoCl{sub 2}]{sub 2} and Cp{sup *}MoCl{sub 4}) has been investigated by {sup 1}H-NMR. The product has a dinuclear, dichloro-bridged structure with a four-legged piano stool geometry around each metal atom; the two piano stools have a mutual anti arrangement and the two metals are 3.888(1) {Angstrom} from each other, indicating the absence of a direct metal-metal bonding interaction. Crystal data: monoclinic, space group P2{submore » 1}/n, a = 8.424(1) {Angstrom}, b = 13.323(4) {Angstrom}, c = 11.266(2) {Angstrom}, {beta} = 93.87(1){degrees}, V = 1261.6(8) {Angstrom}{sup 3}, Z = 2, R = 0.038, R{sub w} = 0.057 for 127 parameters and 1350 observed reflections with F{sub o}{sup 2} > 3{sigma}(F{sub o}{sup 2}). The temperature dependent magnetic moment of the material could be fit to the sum of two Bleany-Bowers equations. [Cp{sup *}MoCl{sub 3}]{sub 2} reacts readily with CO, Cl{sup {minus}}, and PMe{sub 3} to afford Cp{sup *}MoCl{sub 3}(CO){sub 2}, [Cp{sup *}MoCl{sub 4}]{sup {minus}}, and Cp{sup *}MoCl{sub 3}(PMe{sub 3}), respectively, while the reaction with 1,2-bis(diphenylphosphino)ethane (dppe) affords the reduction product Cp{sup *}MoCl{sub 2}(dppe).« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zimmermann, Iwan; Kremer, Reinhard K.; Johnsson, Mats, E-mail: mats.johnsson@mmk.su.se

The new compounds Mn{sub 4}(TeO{sub 3})(SiO{sub 4})X{sub 2} (X=Br, Cl) were synthesized by solid state reactions in sealed evacuated silica tubes. The compounds crystallize in the monoclinic space group P2{sub 1}/m with the unit cell parameters a=5.5463(3) Å (5.49434(7) Å), b=6.4893(4) Å (6.44184(9) Å), c=12.8709(7) Å (12.60451(18) Å), β=93.559(5)° (94.1590(12)°) and Z=2 for the respective Br and Cl analogues. Manganese adopts various distorted coordination polyhedra; [MnO{sub 6}] octahedra, [MnO{sub 5}] tetragonal pyramids and [MnO{sub 2}X{sub 2}] tetrahedra. Other building blocks are [SiO{sub 4}] tetrahedra and [TeO{sub 3}] trigonal pyramids. The structure is made up from layers having no net chargemore » that are connected via weak Van der Waal interactions. The layers that are parallel to (1 1 0) consist of two manganese oxide sheets which are separated by [SiO{sub 4}] tetrahedra. On the outer sides of the sheets are the [MnO{sub 2}X{sub 2}] tetrahedra and the [TeO{sub 3}] trigonal pyramids connected so that the halide ions and the stereochemically active lone pairs on the tellurium atoms protrude from the layers. Magnetic susceptibility measurements reveal a Curie law with a Weiss temperature of θ=−153(3) K for temperatures ≥100 K and indicate antiferromagnetic ordering at T{sub N} ∼4 K. Possible structural origins of the large frustration parameter of f=38 are discussed. - Graphical abstract: Table of contents caption. The new compounds Mn{sub 4}(TeO{sub 3})(SiO{sub 4})X{sub 2} (X=Br, Cl) are layered with weak Van der Waal interactions in between the layers. Manganese adopts various distorted coordination polyhedral, other building blocks are [SiO{sub 4}] tetrahedra and [TeO{sub 3}] trigonal pyramids. Magnetic susceptibility measurements indicate antiferromagnetic ordering at low temperatures and a large frustration parameter. - Highlights: • Two new isostructural oxohalide compounds are described. • The compounds are the first examples of oxohalides containing both Te{sup 4+} and Si{sup 4+}. • Both compounds display the unusual coordination polyhedron MnO{sub 2}X{sub 2} (X=Cl, Br). • The compounds are made up of charge neutral layers connected via weak interactions. • The compounds are antiferromagnetic and display a large frustration parameter.« less

Synthesis and structural characterisation of iron(II) and copper(II) diphosphates containing flattened metal oxotetrahedra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keates, Adam C.; Wang, Qianlong; Weller, Mark T., E-mail: m.t.weller@bath.ac.uk

2014-02-15

Single crystal and bulk polycrystalline forms of K{sub 2}MP{sub 2}O{sub 7} (M=Fe(II), Cu(II)) have been synthesised and their structures determined from single crystal X-ray diffraction data. Both compounds crystallize in the tetragonal system, space group P-42{sub 1}m. Their structures are formed from infinite sheets of linked oxopolyhedra of the stoichiometry [MP{sub 2}O{sub 7}]{sup 2−} with potassium cations situated between the layers. The MO{sub 4} tetrahedra share oxygen atoms with [P{sub 2}O{sub 7}]{sup 4−} diphosphate groups and the potassium ions have KO{sub 8} square prismatic geometry. In both compounds the M(II) centre has an unusual strongly flattened, tetrahedral coordination to oxygen,more » as a result of the Jahn–Teller (JT) effect for the high spin d{sup 6} Fe(II) and p-orbital mixing or a second order JT effect for d{sup 9} Cu(II) centres in four fold coordination. The uncommon transition metal ion environments found in these materials are reflected in their optical absorption spectra and magnetism data. - Graphical abstract: The structures of the tetragonal polymorphs of K{sub 2}MP{sub 2}O{sub 7}, M=Cu(II), Fe(II), consist of infinite sheets of stoichiometry [MP{sub 2}O{sub 7}]{sup 2−}, formed from linked pyrophosphate groups and MO{sub 4} tetrahedra, separated by potassium ions. In both compounds the unusual tetrahedral coordination of the M(II) centre is strongly flattened as a result of Jahn–Teller (JT) effects for high spin, d{sup 6} Fe(II) and p-orbital mixing and second-order JT effects for d{sup 9} Cu(II). Display Omitted - Highlights: • Tetrahedral copper and iron(II) coordinated by oxygen. • New layered phosphate structure. • Jahn–Teller and d{sup 10} distorted coordinations.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamdi, S.; Ouni, S.; Chaker, H.

A new compound DySr{sub 5}Ni{sub 2.4}Cu{sub 0.6}O{sub 12-{delta}} has been prepared by sol gel method and annealed at 1473 K in 1 atm of Ar gas flow. The X-ray diffraction (XRD) is used for phase identification. The sample shows to adopt the K{sub 2}NiF{sub 4}-type structure based on tolerance factor calculation. XRD analysis using the Rietveld method was carried out and it was found that DySr{sub 5}Ni{sub 2.4}Cu{sub 0.6}O{sub 12-{delta}} (Dy{sub 0.33}Sr{sub 1.67}Ni{sub 0.8}Cu{sub 0.2}O{sub 4-{delta}}') compound crystallizes in tetragonal symmetry with space group I4/mmm (Z=2). The lattice parameters are found to be at room temperature a=3.7696(5) A and c=12.3747(2)more » A. The final reliability indices were: R{sub B}=5.219% and {chi}{sup 2}=3.47. Four probe electrical resistivity measurements were performed versus temperature in the range 294-579 K. A semiconducting behaviour over the whole range of temperature, with a conductivity maximum of 0.4 S cm{sup -1} is observed at 510 K. - Graphical abstract: DySr{sub 5}Ni{sub 2.4}Cu{sub 0.6}O{sub 12-{delta}} exhibits a semi-conducting behaviour over the whole temperature range 294-579 K with a conductivity maximum of 0.4 S cm{sup -1} at 510 K. Highlights: > We described our attempts to synthesize the pure compound DySr{sub 5}Ni{sub 2.4}Cu{sub 0.6}O{sub 12-{delta}}. > Product was characterized by XRD and electrical resistivity measurements. > Iodometric titration was used for the analysis of the oxygen nonstoichiometry. > Calculated tolerance factor was included in the tetragonal symmetry stability range. > Compound exhibits a semi-conducting behaviour over the whole temperature range 294-579 K.« less

Sub-antimicrobial Doxycycline for Periodontitis Reduces Hemoglobin A1c in Subjects with Type 2 Diabetes: a Pilot Study

PubMed Central

Engebretson, Steven P.; Hey-Hadavi, Judith

2011-01-01

In vitro and animal studies suggest a possible role for the tetracycline class of drugs in the inhibition of non-enzymatic protein glycation. We conducted a 3-month, randomized placebo-controlled pilot clinical trial of conventional sub-gingival debridement, (periodontal therapy) combined with either a three month regimen of sub-antimicrobial-dose doxycycline (SDD), a two week regimen of antimicrobial-dose doxycycline (ADD), or placebo in 45 patients with long-standing type 2 diabetes (mean duration 9 years) and untreated chronic periodontitis. Subjects were taking stable doses of oral hypoglycemic medications and/or insulin. Treatment response was assessed by measuring hemoglobin A1c (HbA1c),plasma glucose, and clinical periodontal disease measures. At one-month and three-month follow-up, clinical measures of periodontitis were decreased in all groups(data to be presented elsewhere). At three months, mean HbA1c levels in the SDD group were reduced 0.9% unitsfrom 7.2% units ± 2.2(±SD), to 6.3% units ±1.1, which represents a 12.5% improvement. In contrast, there was no significant change in HbA1c in the ADD (7.5%± 2.0 to 7.8%± 2.1) or placebo (8.5%± 2.0 to 8.5%± 2.6) groups. Mean HbA1c change from baseline was significantly greater in the SDD group compared with the ADD group (p=0.04) but not placebo (p=0.22). Moreover, a larger proportion of subjects in the SDD group experienced improvement (p<0.05) compared to the ADD or placebo groups. Mean plasma glucose levels were not significantly different between or within the groups. The results of this pilot study suggest that the treatment of periodontitis with sub-gingival debridement and 3-months of daily sub-antimicrobial-dose doxycycline may decrease HbA1c in patients with type 2 diabetes taking normally prescribed hypoglycemic agents. PMID:21782948

Lubricants or lubricant additives composed of ionic liquids containing ammonium cations

DOEpatents

Qu, Jun [Knoxville, TN; Truhan, Jr; John, J [Cookeville, TN; Dai, Sheng [Knoxville, TN; Luo, Huimin [Knoxville, TN; Blau, Peter J [Knoxville, TN

2010-07-13

A lubricant or lubricant additive is an ionic liquid alkylammonium salt. The alkylammonium salt has the structure R.sub.xNH.sub.(4-x).sup.+,[F.sub.3C(CF.sub.2).sub.yS(O).sub.2].sub.2N.sup- .- where x is 1 to 3, R is independently C.sub.1 to C.sub.12 straight chain alkyl, branched chain alkyl, cycloalkyl, alkyl substituted cycloalkyl, cycloalkyl substituted alkyl, or, optionally, when x is greater than 1, two R groups comprise a cyclic structure including the nitrogen atom and 4 to 12 carbon atoms, and y is independently 0 to 11. The lubricant is effective for the lubrication of many surfaces including aluminum and ceramics surfaces.

The effect of pH on the corrosion behavior of intermetallic compounds Ni{sub 3}(Si,Ti) and Ni{sub 3}(Si,Ti) + 2Mo in sodium chloride solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Priyotomo, Gadang, E-mail: gada001@lipi.go.id; Nuraini, Lutviasari, E-mail: Lutviasari@gmail.com; Kaneno, Yasuyuki, E-mail: kaneno@mtr.osakafu-u.ac.id

The corrosion behavior of the intermetallic compounds, Ni{sub 3}(Si,Ti) (L1{sub 2}: single phase) and Ni{sub 3}(Si,Ti) + 2Mo (L1{sub 2} and (L12 + Ni{sub ss}) mixture region), has been investigated using an immersion test, electrochemical method and surface analytical method (SEM; scanning electron microscope and EDAX: Energy Dispersive X-ray) in 0.5 kmol/m{sup 3} NaCl solutions at various pH. The corrosion behavior of nickel alloy C-276 was studied under the same experimental conditions as a reference. It was found that the uniform attack was observed on Ni{sub 3}(Si,Ti) for the immersion test at lower pH, while the pitting attack was observedmore » on this compound for this test at neutral solution. Furthermore, Ni{sub 3}(Si,Ti)+2Mo had the preferential dissolution of L1{sub 2} compared to (L1{sub 2} + Ni{sub ss}) mixture region at lower pH, while pitting attack occurred in (L1{sub 2} + Ni{sub ss}) mixture region at neutral solution. For both intermetallic compounds, the magnitude of pitting and uniform attack decrease with increasing pH of solutions. From the immersion test and polarization curves, the corrosion resistance of Ni{sub 3}(Si,Ti)+2Mo is lower than that of Ni{sub 3}(Si,Ti), while the nickel alloy C-276 is the highest one at various pH of solutions. On the other hand, in the lower pH of solutions, the corrosion resistance of tested materials decreased significantly compared to those in neutral and higher pH of solutions.« less

Crystallization and preliminary X-ray analysis of Streptococcus mutans dextran glucosidase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saburi, Wataru; Hondoh, Hironori, E-mail: hondoh@abs.agr.hokudai.ac.jp; Unno, Hideaki

2007-09-01

Dextran glucosidase from S. mutans was crystallized using the hanging-drop vapour-diffusion method. The crystals diffracted to 2.2 Å resolution. Dextran glucosidase from Streptococcus mutans is an exo-hydrolase that acts on the nonreducing terminal α-1,6-glucosidic linkage of oligosaccharides and dextran with a high degree of transglucosylation. Based on amino-acid sequence similarity, this enzyme is classified into glycoside hydrolase family 13. Recombinant dextran glucosidase was purified and crystallized by the hanging-drop vapour-diffusion technique using polyethylene glycol 6000 as a precipitant. The crystals belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 72.72, b = 86.47, cmore » = 104.30 Å. A native data set was collected to 2.2 Å resolution from a single crystal.« less

The corrosion of titanium in alkaline peroxide bleach liquors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wyllie, W.E. II; Brown, B.E.; Duquette, D.J.

1994-12-31

An experimental program to determine the effects of hydrogen peroxide (H{sub 2}O{sub 2}) and of potential corrosion inhibitors on the corrosion behavior of titanium has been developed. Corrosion rates less than 0.25 mm/y were observed in laboratory bleach liquor at pH 12 to which 5 g/l of H{sub 2}O{sub 2} were added. At pH 13, with 10 g/l H{sub 2}O{sub 2}, the corrosion rates were unacceptably high in both sodium hydroxide (NaOH) and laboratory bleach liquor solutions (>8.38 mm/y). The preliminary results of inhibitor studies indicated that the addition of 3.7 g/l sodium silicate or 0.01 g/l calcium nitrate (Ca(NO{submore » 3}){sub 2}) effectively inhibited the corrosion of titanium exposed to 5 g/l of H{sub 2}O{sub 2} in NaOH solutions of pH 12. It was also found that in simulated paper mill chemistries, i.e., basic solutions containing 3.7 g/l sodium silicate and 0.6 g/l EDTA (ethylenediaminetetraacetic acid), corrosion rates increased markedly with the addition of 5 g/l H{sub 2}O{sub 2}. However, subsequent additions of peroxide resulted in corrosion rates which were even lower than those found in NaOH. This is believed to be due to the formation of a black scale on the surface of the sample. The addition of magnesium sulfate (MgSO{sub 4}) in the 0.1--0.5 g/l range also was shown to inhibit corrosion in the NaOH solution, but only after prior exposure to H{sub 2}O{sub 2}.« less

Acceleration of polarized protons to 22 GeV/c and the measurement of spin-spin effects in p/sub up-arrow/+p/sub up-arrow/. -->. p+p

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khiari, F.Z.; Cameron, P.R.; Court, G.R.

1989-01-01

Accelerating polarized protons to 22 GeV/c at the Brookhaven Alternating Gradient Synchro- tron required both extensive hardware modifications and a difficult commissioning process. We had to overcome 45 strong depolarizing resonances to maintain polarization up to 22 GeV/c in this strong-focusing synchrotron. At 18.5 GeV/c we measured the analyzing power A and the spin-spin correlation parameter A/sub n//sub n/ in large- P/sub perpendicular//sup 2/ proton-proton elastic scattering, using the polarized proton beam and a polarized proton target. We also obtained a high-precision measurement of A at P/sub perpendicular//sup 2/ = 0.3 (GeV/c)/sup 2/ at 13.3 GeV/c. At 18.5 GeV/c wemore » found that A/sub n//sub n/ = (-2 +- 16)% at P/sub perpendicular//sup 2/ = 4.7 (GeV/c)/sup 2/, where it was about 60% near 12 GeV at the Argonne Zero Gradient Synchrotron. This sharp change suggests that spin-spin forces may have a strong and unexpected energy dependence at high P/sub perpendicular//sup 2/.« less

[Effects of n-hexane exposure on human serum myelin basic proteins].

PubMed

Zhou, Wei; Yi, Juan; Huang, Hui-Ping; Xiang, Ying-Ping; He, Jia-Xi; Liu, Qing-Jun; Huang, Xian-Qing

2011-06-01

To explore the effects of n-hexane on expression of serum myelin proteins (MBP) in workers occupationally exposed to n-hexane. In this study, 269 workers exposed to n-hexane for more than one year and 104 subjects not exposed to n-hexane served as the exposure group and the control group, respectively. The urinary 2,5-hexanedione levels in all subjects were detected. On the basis of urinary 2,5-hexanedione levels, the exposure group was divided into the high exposure sub-group and low exposure sub-group. The serum myelin basic protein (MBP) levels were measured by ELISA kit. The mean concentration of urinary 2,5-hexanedione in the exposed group was (3.10 +/- 1.35) mg/L. The concentration of urinary 2,5-hexanedione in the control group was undetectable. The levels of serum MBP in the high exposure sub-group and low exposure sub-group were (2.43 +/- 0.24) and (1.62 +/- 0.23) microg/L, respectively, which were significantly higher than that (0.78 +/- 0.12) microg/L in the controls (P < 0.01). Pearson correlation analysis showed the positive correlation between serum MBP levels and urinary 2,5-hexanedione levels (r = 0.781, P < 0.01). The results of present study showed that the serum MBP levels of workers occupationally exposed to n-hexane significantly elevated, and the serum MBP can serve as the effective biomarker of n-hexane exposure.

Crystallization and preliminary X-ray analysis of the inducible lysine decarboxylase from Escherichia coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alexopoulos, Eftichia; Department of Medical Biophysics, University of Toronto, Division of Cancer Genomics and Proteomics, Ontario Cancer Institute, Toronto Medical Discovery Tower, 101 College Street, Toronto, Ontario M5G 1L7; Kanjee, Usheer

2008-08-01

The structure of the decameric inducible lysine decarboxylase from E. coli was determined by SIRAS using a hexatantalum dodecabromide (Ta{sub 6}Br{sub 12}{sup 2+}) derivative. Model building and refinement are under way. The decameric inducible lysine decarboxylase (LdcI) from Escherichia coli has been crystallized in space groups C2 and C222{sub 1}; the Ta{sub 6}Br{sub 12}{sup 2+} cluster was used to derivatize the C2 crystals. The method of single isomorphous replacement with anomalous scattering (SIRAS) as implemented in SHELXD was used to solve the Ta{sub 6}Br{sub 12}{sup 2+}-derivatized structure to 5 Å resolution. Many of the Ta{sub 6}Br{sub 12}{sup 2+}-binding sites hadmore » twofold and fivefold noncrystallographic symmetry. Taking advantage of this feature, phase modification was performed in DM. The electron-density map of LdcI displays many features in agreement with the low-resolution negative-stain electron-density map [Snider et al. (2006 ▶), J. Biol. Chem.281, 1532–1546].« less

Li{sub 3}Gd{sub 3}Te{sub 2}O{sub 12}:Eu{sup 3+}- an intense red phosphor for solid state lighting applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tiwari, Hansnath; Asiri Naidu, S.; Varadaraju, U.V., E-mail: varada@iitm.ac.in

Li{sub 3}Gd{sub 3−3x}Eu{sub 3x}Te{sub 2}O{sub 12} (x=0.05−1.0) phases with garnet structure were synthesized by high temperature solid state reaction and the photoluminescence properties were investigated. The appearance of bands due to intra 4 f transitions of Gd{sup 3+} in the excitation spectra recorded by monitoring the 612 nm emission line of the activator indicates Gd{sup 3+}→Eu{sup 3+} energy transfer in this host lattice. Under 395 nm excitation, the electric dipole transition is predominant in the emission spectrum of Eu{sup 3+} and is in agreement with the C{sub 2} point group (noncentrosymmetric) of the EuO{sub 8} polyhedron. The critical concentration ofmore » the Eu{sup 3+} activator in this series was found to be 0.6 (x=0.2) above which, concentration quenching occurs. The emission intensity of the phosphor composition, Li{sub 3}Gd{sub 2.4}Eu{sub 0.6}Te{sub 2}O{sub 12} is ~4 times that of the commercial sample of Y{sub 2}O{sub 3}:Eu{sup 3+} phosphor. - Highlights: • New Eu{sup 3+} doped garnet. • Intense electric dipole emission. • Gd{sup 3+}→Eu{sup 3+} energy transfer.« less

Explicit blow-up solutions to the Schroedinger maps from R{sup 2} to the hyperbolic 2-space H{sup 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding Qing

2009-10-15

In this article, we prove that the equation of the Schroedinger maps from R{sup 2} to the hyperbolic 2-space H{sup 2} is SU(1,1)-gauge equivalent to the following 1+2 dimensional nonlinear Schroedinger-type system of three unknown complex functions p, q, r, and a real function u: iq{sub t}+q{sub zz}-2uq+2(pq){sub z}-2pq{sub z}-4|p|{sup 2}q=0, ir{sub t}-r{sub zz}+2ur+2(pr){sub z}-2pr{sub z}+4|p|{sup 2}r=0, ip{sub t}+(qr){sub z}-u{sub z}=0, p{sub z}+p{sub z}=-|q|{sup 2}+|r|{sup 2}, -r{sub z}+q{sub z}=-2(pr+pq), where z is a complex coordinate of the plane R{sup 2} and z is the complex conjugate of z. Although this nonlinear Schroedinger-type system looks complicated, it admits a class ofmore » explicit blow-up smooth solutions: p=0, q=(e{sup i(bzz/2(a+bt))}/a+bt){alpha}z, r=e{sup -i(bzz/2(a+bt))}/(a+bt){alpha}z, u=2{alpha}{sup 2}zz/(a+bt){sup 2}, where a and b are real numbers with ab<0 and {alpha} satisfies {alpha}{sup 2}=b{sup 2}/16. From these facts, we explicitly construct smooth solutions to the Schroedinger maps from R{sup 2} to the hyperbolic 2-space H{sup 2} by using the gauge transformations such that the absolute values of their gradients blow up in finite time. This reveals some blow-up phenomenon of Schroedinger maps.« less

New Antimony Lanthanide Disulfide Dibromides LnSbS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gout, D.; Jobic, S.; Evain, M.

2001-05-01

CeSbS{sub 2}Br{sub 2} (I), Ce{sub 1/2}La{sub 1/2}SbS{sub 2}Br{sub 2} (II), and LaSbS{sub 2}Br{sub 2} (III) have been synthesized at 700 C from a mixture of LnBr{sub 3}, Ln{sub 2}S{sub 3}, Sb, and S and characterized by single-crystal X-ray diffraction. The three phases are isostructural (space group P2{sub 1}/c, Z=4) and crystallize in a novel, dense, bidimensional structure with cell parameters a=8.709(3) {angstrom}, b=9.187(2) {angstrom}, c=17.397(5) {angstrom} {beta}=104.26(3) for I, a=8.739(7) {angstrom}, b=9.219(7) {angstrom}, c=17.41(2) {angstrom}, =104.3(1) for II, and a=8.785(1) {angstrom}, b=9.236(2) {angstrom}, c=17.372(3) {angstrom}, {beta}=104.09(2) for III. In these compounds, [Ln S{sub 5}Br{sub 4}] and [Ln S{sub 3}Br{sub 6}]more » (Ln=Ce, La) distorted tricapped trigonal prisms define infinite {sub {infinity}}{sup 2}[LnS{sub 2}Br{sub 2}] layers counterbalanced and capped by antimony cations. In good accordance with the structural features, the charge balance in these materials is to be written Ln{sup III}Sb{sup III}S{sup -II}{sub 2}Br{sup -I}{sub 2}. These compounds exhibit a yellow hue with a measured absorption threshold of 2.42(1), 2.55(1), and 2.72(1) eV for I, II, and III, respectively. In the two cerium containing bromothioantimonates I and II, the origin of the color is assigned to a Ce-4f{yields}Ce-5d electronic transition, which shifts to higher energy from I to II due either to a matrix effect (increase of the mean Ln-S distances under the substitution of Ce for La) or to an atomic ordering between Ce and La cations on the Ln(1) and Ln(2) crystallographic sites. In contrast, the electronic transition at play in III involves a charge transfer from the bromine and sulfur ions to the antimony ions, the latter contributing substantially to the lowermost levels of the conduction band.« less

Photoionization of N,N,N[prime],N[prime]-tetramethylbenzidine in a mixed micelle of ionic and nonionic surfactants: Electron spin-echo modulation and electron spin resonance studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baglioni, P.; Rivara-Minten, E.; Stenland, C.

1991-11-28

Electron spin-echo modulation (ESEM) and electron spin resonance (ESR) spectra of the photogenerated N,N,N[prime],N[prime]-tetramethylbenzidine (TMB) cation radical in frozen mixed micelles of sodium dodecyl sulfate (SDS) or dodecyltrimethylammonium chloride (DTAC) and hexakis(ethylene glycol) monododecyl ether (C[sub 12]E[sub 6]), selectively deuterated along the poly(ethylene glycol) group (C[sub 12]D[sub 6]) or along the alkyl chain ((CD)[sub 12]E[sub 6]), have been studied as a function of the mixed-micelle composition in H[sub 2]O and D[sub 2]O. ESEM effects due to TMB[sup +] interactions with deuterium in D[sub 2]O show a decrease of the TMB[sup +]-water interactions for the system DTAC/C[sub 12]E[sub 6] and anmore » increase for the system SDS/C[sub 12]E[sub 6] that depend on the composition of the mixed micelle. The location of TMB[sup +] in the mixed micelles, deduced by comparing the modulation effects due to interactions of the photocation with water deuteriums or deuteriums of deuterated surfactants, is reported for the SDS/C[sub 12]E[sub 6] and DTAC/C[sub 12]E[sub 6] mixed micelles. The efficiency of charge separation upon the photoionization of TMB to produce TMB[sup +] measured by ESR correlates with the surface charge and with the degree of water penetration into the mixed micelle.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiyota, Eduardo; Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas-SP; Sousa, Sylvia Morais de

Preliminary X-ray diffraction studies of apo maize aldose reductase at 2.0 Å resolution are reported. Maize aldose reductase (AR) is a member of the aldo-keto reductase superfamily. In contrast to human AR, maize AR seems to prefer the conversion of sorbitol into glucose. The apoenzyme was crystallized in space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 47.2, b = 54.5, c = 100.6 Å and one molecule in the asymmetric unit. Synchrotron X-ray diffraction data were collected and a final resolution limit of 2.0 Å was obtained after data reduction. Phasing was carried out by an automatedmore » molecular-replacement procedure and structural refinement is currently in progress. The refined structure is expected to shed light on the functional/enzymatic mechanism and the unusual activities of maize AR.« less

Synthesis of labeled oxalic acid derivatives

DOEpatents

Martinez, Rodolfo A.; Unkefer, Clifford J.; Alvarez, Marc A.

2004-06-22

The present invention is directed to labeled compounds, specifically ##STR1## where each C* is selected from the group consisting of a carbon-12, i.e., .sup.12 C, or a carbon-13, i.e., .sup.13 C and at least one C* is .sup.13 C, R.sup.1 is selected from the group of C.sub.1 -C.sub.4 lower alkyl and aryl, and X is selected from the group of --NR.sup.2 R.sup.3 where R.sup.2 and R.sup.3 are each independently selected from the group of C.sub.1 -C.sub.4 lower alkyl, alkoxy and aryl, --SR.sup.4 where R.sup.4 is selected from the group of C.sub.1 -C.sub.4 lower alkyl, alkoxy and aryl, and --OR.sup.5 where R.sup.5 is selected from the group of C.sub.1 -C.sub.4 lower alkyl, alkoxy and aryl with the proviso that when R.sup.1 is methyl then R.sup.5 is other than methyl, when R.sup.1 is ethyl then R.sup.5 is other than ethyl, and when R.sup.1 is benzyl then R.sup.5 is other than benzyl.

A meta-analysis of the effect of CYP2D6 polymorphism on the pharmacokinetics and pharmacodynamics of metoprolol
.

PubMed

Li, Shuchun; Lin, Han; Sun, WenHuan; Wang, YingLi; Ding, YouFang; Zhao, HuanHu; Liu, ShangJian

2017-06-01

To conduct a meta-analysis on the effect of CYP2D6 polymorphism on the pharmacokinetics and pharmacodynamics of metoprolol. A systematic review and meta-analysis of studies on the effect of CYP2D6 polymorphism on metoprolol pharmacokinetics and pharmacodynamics was performed by using the China national knowledge infrastructure (CNKI), database for Chinese technical periodicals (VIP), Wanfang, and PubMed databases up to the end of January 2015. Review Manager 5.3 (the coherence collaboration, www.gradepro.org) and comprehensive Meta-Analysis Software v2 (CMA) Biostat, Englewood, NJ, USA) were used for meta-analysis. A total of 567 cases from 7 studies were included in the present study. Meta-analysis results showed that the area under the curve (AUC)_0-∞ (RR = -6.75, 95% CI (-9.18, -4.31), p < 0.00001); C_max (RR = -2.40, 95% CI (-3.25, -1.54), p < 0.00001); T_1/2 (RR = -4.81, 95% CI (-6.86, -2.76), p < 0.00001); CL/F (RR = 1.60, 95% CI (1.03,2.17), p < 0.00001); heart rate (RR = 1.48, 95% CI (0.03, 2.92), p = 0.05), systolic blood pressure (RR = -0.69, 95% CI (-1.85,0.47), p = 0.24); and diastolic blood pressure (RR = -1.95, 95% CI (-3.14, -0.76), p = 0.001). Begg's funnel plot test showed that the pharmacokinetic parameters (AUC_0-∞, C_max, T_1/2, and CL/F) and pharmacodynamic parameters (HR, DBP, and SBP) were symmetric. Egger's test showed that the pharmacokinetic parameters were asymmetrical, and its intercept was statistically significant (p < 0.05), which was indicative of publication bias. The pharmacodynamic parameter intercept was not statistically significant (p > 0.05), indicating that no publication bias existed. CYP2D6 polymorphism significantly influenced the pharmacokinetic parameters of metoprolol. It also affected heart rate and diastolic blood pressure, whereas systolic pressure was not affected.
.

Ground-based multiwavelength observations of comet 103P/Hartley 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gicquel, A.; Villanueva, G. L.; Cordiner, M. A.

2014-10-10

The Jupiter-family comet 103P/Hartley 2 (103P) was the target of the NASA EPOXI mission. In support of this mission, we conducted observations from radio to submillimeter wavelengths of comet 103P in the three weeks preceding the spacecraft rendezvous on UT 2010 November 4.58. This time period included the passage at perihelion and the closest approach of the comet to the Earth. Here, we report detections of HCN, H{sub 2}CO, CS, and OH and upper limits for HNC and DCN toward 103P using the Arizona Radio Observatory Kitt Peak 12 m telescope (ARO 12 m) and submillimeter telescope (SMT), the Jamesmore » Clerk Maxwell Telescope (JCMT), and the Green Bank Telescope (GBT). The water production rate, Q{sub H{sub 2O}} = (0.67-1.07) × 10{sup 28} s{sup –1}, was determined from the GBT OH data. From the average abundance ratios of HCN and H{sub 2}CO relative to water (0.13 ± 0.03% and 0.14 ± 0.03%, respectively), we conclude that H{sub 2}CO is depleted and HCN is normal with respect to typically observed cometary mixing ratios. However, the abundance ratio of HCN with water shows a large diversity with time. Using the JCMT data, we measured an upper limit for the DCN/HCN ratio <0.01. Consecutive observations of ortho-H{sub 2}CO and para-H{sub 2}CO on November 2 (from data obtained at the JCMT) allowed us to derive an ortho:para ratio (OPR) of ≈2.12 ± 0.59 (1σ), corresponding to T {sub spin} > 8 K (2σ).« less

State selected ion--molecule reactions by a TESICO technique. IV. Relative importance of the two spin-orbit states of Ar/sup +/ in the charge transfer reactions with N/sub 2/ and CO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kato, T.; Tanaka, K.; Koyano, I.

1982-07-01

Charge transfer reactions Ar/sup +/ (/sup 2/P/sub J/)+N/sub 2/..-->..N/sup +//sub 2/+Ar (1) and Ar/sup +/(/sup 2/P/sub J/)+CO..-->..CO/sup +/+Ar (2) have been studied for the two spin-orbit states (J = 3/2 and 1/2) separately using the threshold electron-secondary ion coincidence (TESICO) technique. Relative cross sections for the two states sigma(3/2) and sigma(1/2) have been determined at three collision energies 0.2, 1.4, and 5.8 eV. It has been found that in Reaction (1), sigma(3/2) is larger than sigma (1/2) with ratio sigma(1/2)/sigma(3/2) ranging from 0.5 to 0.8 depending on the collision energy, whereas in Reaction (2), sigma(1/2) is larger than sigma(3/2) withmore » the ratio ranging from 1.2 to 1.6. The implications of these results are discussed with regard to the roles of energy resonance and Franck--Condon factors in charge transfer processes.« less

Structural trends for celestite (SrSO[subscript 4]), anglesite (PbSO[subscript 4]), and barite (BaSO[subscript 4]): Confirmation of expected variations within the SO[subscript 4] groups

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antao, Sytle M.

2012-05-10

The crystal structures of the isostructural orthorhombic sulfates celestite (SrSO{sub 4}), anglesite (PbSO{sub 4}), and barite (BaSO{sub 4}) were refined by Rietveld methods using synchrotron high-resolution powder X-ray diffraction (HRPXRD) data. Their structural model was refined in space group Pbnm. The unit-cell parameters are a = 6.87032(3), b = 8.36030(5), c = 5.34732(1) {angstrom}, and V = 307.139(3) {angstrom}{sup 3} for SrSO{sub 4}; a = 6.95802(1), b = 8.48024(3), c = 5.39754(1) {angstrom}, and V = 318.486(1) {angstrom}{sup 3} for PbSO{sub 4}; and a = 7.15505(1), b = 8.88101(3), c = 5.45447(1) {angstrom}, and V = 346.599(1) {angstrom}{sup 3} formore » BaSO{sub 4}. The average [12] distances are 2.827(1), 2.865(1), and 2.953(1) {angstrom} for SrSO{sub 4}, PbSO{sub 4}, and BaSO{sub 4}, respectively, and their corresponding average [4] distances are 1.480(1), 1.477(3), and 1.471(1) {angstrom}. The geometrical features of the SO{sub 4} and MO{sub 12} polyhedra become more symmetrical from SrSO{sub 4} to BaSO{sub 4}. Across the series, the a, b, and c parameters vary non-linearly with increasing V. The radii of the M{sup 2+} cations, rM, [12], and [4] distances vary linearly with V. These structural trends arise from the effective size of the M{sup 2+} cation (rM: Sr < Pb < Ba) that is coordinated to 12 O atoms.« less

Crystal structure of the mineral (Na,Ca,K){sub 2}(Ca,Na){sub 4}(Mg,Fe){sub 5}(Mg,Fe,Ti){sub 5}[Si{sub 12}Al{sub 4}O{sub 44}](F,O){sub 4}: a triclinic representative of the amphibole family

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rastsvetaeva, R. K., E-mail: rast@ns.crys.ras.ru; Aksenov, S. M.

2012-05-15

A mineral belonging to the amphibole family found at the Rothenberg paleovolcano (Eifel, Germany) was studied by single-crystal X-ray diffraction. The triclinic pseudomonoclinic unit-cell parameters are a = 5.3113(1) Angstrom-Sign , b = 18.0457(3) Angstrom-Sign ; c = 9.8684(2) Angstrom-Sign , {alpha} = 90.016(2) Degree-Sign , {beta} = 105.543(4) Degree-Sign , {gamma} = 89.985(2) Degree-Sign . The structure was solved by direct methods in sp. gr. P1 and refined to the R factor of 2.7% based on 6432 reflections with |F| > 3{sigma}(F) taking into account twinning. The mineral with the idealized formula (Na,Ca,K){sub 2}(Ca,Na){sub 4}(Mg,Fe){sub 5}(Mg,Fe,Ti){sub 5}[Si{sub 12}Al{sub 4}O{submore » 44}](F,O){sub 4} has some symmetry and structural features that distinguish it from other minerals of this family.« less

High-temperature, high-pressure hydrothermal synthesis, characterization, and structural relationships of mixed-alkali metals uranyl silicates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Yi-Hsin; Liu, Hsin-Kuan; Chang, Wen-Jung

2016-04-15

Three mixed-alkali metals uranyl silicates, Na{sub 3}K{sub 3}[(UO{sub 2}){sub 3}(Si{sub 2}O{sub 7}){sub 2}]·2H{sub 2}O (1), Na{sub 3}Rb{sub 3}[(UO{sub 2}){sub 3}(Si{sub 2}O{sub 7}){sub 2}] (2), and Na{sub 6}Rb{sub 4}[(UO{sub 2}){sub 4}Si{sub 12}O{sub 33}] (3), have been synthesized by high-temperature, high-pressure hydrothermal reactions at 550 °C and 1440 bar, and characterized by single-crystal X-ray diffraction, photoluminescence, and thermogravimetric analysis. Compound 1 and 2 are isostructural and contain layers of uranyl disilicate. The smaller cation, Na{sup +}, is located in the intralayer channels, whereas the larger cations, K{sup +} and Rb{sup +}, and water molecule are located in the interlayer region. The absencemore » of lattice water in 2 can be understood according to the valence-matching principle. The structure is related to that of a previously reported mixed-valence uranium(V,VI) silicate. Compound 3 adopts a 3D framework structure and contains a unique unbranched dreier fourfold silicate chain with the structural formula {uB,4"1_∞}[{sup 3}Si{sub 12}O{sub 33}] formed of Q{sup 2}, Q{sup 3}, and Q{sup 4} Si. The connectivity of the Si atoms in the Si{sub 12}O{sub 33}{sup 18−} anion can be interpreted on the basis of Zintl–Klemm concept. Crystal data for compound 1: triclinic, P-1, a=5.7981(2) Å, b=7.5875(3) Å, c=12.8068(5) Å, α=103.593(2)°, β=102.879(2)°, γ=90.064(2)°, V=533.00(3) Å{sup 3}, Z=1, R1=0.0278; compound 2: triclinic, P-1, a=5.7993(3) Å, b=7.5745(3) Å, c=12.9369(6) Å, α=78.265(2)°, β=79.137(2)°, γ=89.936(2)°, V=546.02(4) Å{sup 3}, Z=1, R1=0.0287; compound 3: monoclinic, C2/m, a=23.748(1) Å, b=7.3301(3) Å, c=15.2556(7) Å, β=129.116(2)°, V=2060.4(2) Å{sup 3}, Z=2, R1=0.0304. - Graphical abstract: Three mixed-alkali metals uranyl silicates were synthesized under hydrothermal conditions at 550 °C and 1400 bar and structurally characterized by single-crystal X-ray diffraction. Two of them have a layer structure with the alkali metal cations within and between the layers. The third one adopts a 3D framework structure and contains a unique unbranched dreier fourfold silicate chain formed of Q{sup 2}, Q{sup 3}, and Q{sup 4} Si. - Highlights: • Three new mixed-alkali metals uranyl silicates were synthesized by high-T, high-P hydrothermal method and structurally. • Two compounds adopt a layer structure and the third one has a 3D framework structure. • The 3D framework structure contains a unique unbranched dreier fourfold silicate chain formed of Q{sup 2}, Q{sup 3}, and Q{sup 4} Si.« less

The elastic constants of San Carlos olivine to 17 GPa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abramson, E.H.; Brown, J.M.; Slutsky, L.J.

1997-06-01

All elastic constants, the average bulk and shear moduli, and the lattice parameters of San Carlos olivine (Fo{sub 90}) (initial density 3.355gm/cm{sup 3}) have been determined to a pressure of 12 GPa at room temperature. Measurements of c{sub 11}, c{sub 33}, c{sub 13}, and c{sub 55} have been extended to 17 GPa. The pressure dependence of the adiabatic, isotropic (Hashin-Shtrikman bounds) bulk modulus, and shear modulus may be expressed as K{sub HS}=129.4+4.29P and by G{sub HS}=78+1.71P{minus}0.027P{sup 2}, where both the pressure and the moduli are in gigapascals. The isothermal compression of olivine is described by a bulk modulus given asmore » K{sub T}=126.3+4.28P. Elastic constants other than c{sub 55} can be adequately represented by a linear relationship in pressure. In the order (c{sub 11},c{sub 12},c{sub 13},c{sub 22},c{sub 23},c{sub 33},c{sub 44},c{sub 55},c{sub 66}) the 1 bar intercepts (gigapascal units) are (320.5, 68.1, 71.6, 196.5, 76.8, 233.5, 64.0, 77.0, 78.7). The first derivatives are (6.54, 3.86, 3.57, 5.38, 3.37, 5.51, 1.67, 1.81, 1.93). The second derivative for c{sub 55} is {minus}0.070GPa{sup {minus}1}. Incompressibilities for the three axes may also be expressed as linear relationships with pressure. In the order of {bold a, b}, and {bold c} axes the intercepts in gigapascals are (547.8, 285.8, 381.8) and the first derivatives are (20.1, 12.3, 14.0).{copyright} 1997 American Geophysical Union« less

Structure and physical properties of EuTa{sub 2}O{sub 6} tungsten bronze polymorph

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolodiazhnyi, T., E-mail: kolodiazhnyi.taras@nims.go.jp; Sakurai, H.; Vasylkiv, O.

A tetragonal tungsten bronze (TTB) polymorph of EuTa{sub 2}O{sub 6} was prepared and analyzed. EuTa{sub 2}O{sub 6} crystallizes in the centrosymmetric Pnam space group (with unit cell: a = 12.3693, b = 12.4254, and c = 7.7228 Å) isomorphous with orthorhombic β-SrTa{sub 2}O{sub 6}. In contrast to early reports, we see no evidence of deviation from paramagnetic Curie-Weiss behavior among the Eu{sup 2+} 4f{sup 7}spins in EuTa{sub 2}O{sub 6} down to 2 K. Dielectric constant shows a broad peak at ca. 50 K with dielectric dispersion resembling diffuse phase transition. The relaxation time, however, follows a simple (non-freezing) thermally activated process with an activation energy of 92 meV and anmore » attempt frequency of f{sub 0} = 5.79 × 10{sup 12 }Hz. A thermal conductivity of EuTa{sub 2}O{sub 6} shows a low-temperature (T ≈ 30 K) “plateau” region reminiscent of a glass-like behaviour in Nb-based TTB compounds. This behaviour can be attributed to the loosely bound Eu{sup 2+} ions occupying large tricapped trigonal prismatic sites in the EuTa{sub 2}O{sub 6} structure.« less

Piezo-/dielectric properties of perovskite-structure high-temperature relaxor ferroelectrics: The Pb(Lu{sub 1/2}Nb{sub 1/2})O{sub 3}–Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} ternary ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Tao; University of Chinese Academy of Sciences, Beijing 100049; Long, Xifa, E-mail: lxf@fjirsm.ac.cn

2014-03-01

Graphical abstract: - Highlights: • Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}-based ternary ferroelectric ceramics were prepared by solid-state synthesis method. • Morphotropic phase boundary region has been determined by XRD, di-/piezoelectric properties. • The compositions near MPB region exhibit excellent piezoelectric properties. - Abstract: A new compositional system of relaxor ferroelectrics was investigated based on the high piezoelectricity Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} ferroelectric perovskite family. Compositions were fabricated near an estimated morphotropic phase boundary (MPB) of the Pb(Lu{sub 1/2}Nb{sub 1/2})O{sub 3}–Pb(Zn{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} (PLZNT) ternary system by a two-step synthetic process. Their structures have been analyzed by means ofmore » X-ray diffraction technique. On the basis of X-ray powder diffraction, the morphotropic phase boundary (MPB) region for the ternary system was obtained. The Curie temperature T{sub C} of ternary system varied from 240 °C to 330 °C and the coercive fields E{sub c}s > 10 kV/cm. The values of piezoelectric coefficients d{sub 33} vary in the range of 260–450 pC/N with different PZN contents. It is worth noting that the optimum compositions were located at MPB region but near the tetragonal phase. The new PLZNT ceramics exhibit wider range of T{sub C}s and E{sub c}s, making it a promising material for high-powder ultrasound transducers using in a large temperature range.« less

Erbium-doped borosilicate glasses containing various amounts of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3}: Influence of the silica content on the structure and thermal, physical, optical and luminescence properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourhis, Kevin; Massera, Jonathan; BioMediTech, Tampere

2015-10-15

Highlights: • Er{sup 3+} doped borosilicate glasses were processed with different compositions and characterizations. • An increase in the SiO{sub 2} content leads to a silicate-rich environment around the Er{sup 3+} site. • An increase in the SiO{sub 2} content decreases the Er{sup 3+} absorption cross-section at 980 nm. • Glasses with 60 mol% of SiO{sub 2} exhibit a stronger emission intensity at 1530 nm than glasses with x = 50. • Highest 1.5 μm emission intensity was achieved for the Al and P containing glass with 60 mol% of SiO{sub 2}. - Abstract: The influence of the silica contentmore » on several properties of Er-doped borosilicate glasses in the presence of various amounts of P{sub 2}O{sub 5} and Al{sub 2}O{sub 3} has been investigated. The introduction of P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} are responsible for structural modifications in the glass network through a charge-compensation mechanism related to the formation of negatively-charged PO{sub 4} and AlO{sub 4} groups or through the formation of AlPO{sub 4}-like structural units. In this paper, we show that an increase in the SiO{sub 2} content leads to a silicate-rich environment around the Er{sup 3+} site, resulting in an increased dependence of the Er{sup 3+} ions optical and luminescence properties on the P{sub 2}O{sub 5} and/or Al{sub 2}O{sub 3} concentration. The highest emission intensity at 1.5 μm was achieved for the glass with an equal proportion of P and Al in the glass system with 60 mol% of SiO{sub 2}.« less

Five inorganic–organic hybrids based on Keggin polyanion [SiMo{sub 12}O{sub 40}]{sup 4−}: From 0D to 2D network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Xiao-Yang, E-mail: yangyangyu0103@sohu.com; Jilin Institute of Chemical Technology, Jilin City, Jilin 132022; Cui, Xiao-Bing

2014-01-15

Five new inorganic–organic hybrids based on 4,4′-bipyridine and Keggin-type polyoxometalate [SiMo{sub 12}O{sub 40}]{sup 4−}, (SiMo{sub 12}O{sub 40})(H{sub 2}bipy){sub 2}·2H{sub 2}O (1), [Cu(Hbipy){sub 4}(HSiMo{sub 12}O{sub 40})(SiMo{sub 12}O{sub 40})](H{sub 2}bipy){sub 0.5}·7H{sub 2}O (2), [Cu{sub 2}(Hbipy){sub 6}(bipy)(SiMo{sub 12}O{sub 40}){sub 3}](Hbipy){sub 2}·6H{sub 2}O (3), [Cu(bipy){sub 2}(SiMo{sub 12}O{sub 40})](H{sub 2}bipy)·2H{sub 2}O (4) and [Cu{sub 2}(bipy){sub 4}(H{sub 2}O){sub 4}](SiMo{sub 12}O{sub 40})·13H{sub 2}O (5) (bipy=4,4′-bipyridine), have been hydrothermally synthesized. 1 consists of H{sub 2}bipy{sup 2+} and [SiMo{sub 12}O{sub 40}]{sup 4−} units. In 2, two [SiMo{sub 12}O{sub 40}]{sup 4−} are bridged by [Cu(Hbipy){sub 4}]{sup 6+} to form a [Cu(Hbipy){sub 4}(SiMo{sub 12}O{sub 40}){sub 2}]{sup 2−} dimmer. In 3, [SiMo{submore » 12}O{sub 40}]{sup 4−} polyanions acting as bidentated bridging ligands and monodentated auxiliary ligands connect [Cu{sub 2}(Hbipy){sub 6}(bipy)]{sup 8+} units into a 1D zigzag chain. In 4, [SiMo{sub 12}O{sub 40}]{sup 4−} polyanions bridge neighboring 1D [Cu(bipy){sub 2}]{sup 2+} double chains into a 2D extended layer. In 5, [SiMo{sub 12}O{sub 40}]{sup 4−} polyanions acting as templates site alternately upon the grids from both sides of the square grid [Cu{sub 2}(bipy){sub 4}(H{sub 2}O){sub 4}]{sup 4+} layer. In addition, the electrochemical behaviors of 1, 3 and 4 and the photocatalysis property of 1 have been investigated. - Graphical abstract: Five new compounds based on [SiMo{sub 12}O{sub 40}]{sup 4−} have been successfully generated. [SiMo{sub 12}O{sub 40}]{sup 4−} anions play different roles in the structures of the five compounds. Display Omitted - Highlights: • Five new compounds based on [SiMo{sub 12}O{sub 40}]{sup 4−} have been generated. • [SiMo{sub 12}O{sub 40}]{sup 4−} anions play different roles in the five structures. • The electrochemical behaviors of 1, 3 and 4 have been investigated. • The photocatalysis property of 1 has been investigated.« less

Synthesis, evaluation and defect compensation of tetrahedral glasses as possible solar cell materials. Final report, February 1, 1979-April 30, 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rauh, R.D.; Rose, T.L.; Scoville, A.N.

1980-04-01

The work reported was directed towards evaluation of new amorphous compounds for application in solar cells. The ternary A/sup II/B/sup IV/C/sub 2//sup V/ chalcopyrite systems were selected because of their inexpensive constituent elements and tetrahedral geometry. Polycrystalline samples of the ternary arsenides with Cd and Zn as the group II element and Ge, Si, Sn as the group IV element were synthesized. Thin films were deposited by vacuum evaporation of the bulk ternary arsenides. The stoichiometries of the films were irreproducible and were usually deficient in the lower vapor pressure group IV element. Films made by evaporating polycrystalline ZnAs/sub 2/,more » which also has a tetrahedral bonding structure, had stoichiometries generally in the range from Zn/sub 3/As/sub 2/ to ZnAs/sub 2/. The former compound is formed by the decomposition of ZnAs/sub 2/ to Zn/sub 3/As/sub 2/ and As/sub 4/. The intermediate stoichiometries are thought to be mixtures of the decomposition products. Preliminary results from annealing of the films indicate that heat treatment produces the stoichiometries expected for one of the two forms of zinc arsenide. The as-deposited films are amorphous when the substrate temperature is kept below 100/sup 0/C. The a-ZnAs/sub x/ films were characterized. EDAX and Auger analysis showed that films were homogeneous in the plane of the substrate, but that some variation occurred in the depth profile of the films. This change in composition is consistent with the sample decomposition which occurs during the evaporation. The as-prepared films were p-type with room temperature resistivities on the order of 10/sup 2/-10/sup 4/..cap omega..-cm. Optical absorption measurements gave optical band gap values of 1.2 eV for a-Zn/sub 3/As/sub 2/ and 1.5 eV for a-ZnAs/sub 2/. The ZnAs/sub x/ films were photoconductive.« less

The Minkowski sum of a zonotope and the Voronoi polytope of the root lattice E{sub 7}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grishukhin, Vyacheslav P

2012-11-30

We show that the Minkowski sum P{sub V}(E{sub 7})+Z(U) of the Voronoi polytope P{sub V}(E{sub 7}) of the root lattice E{sub 7} and the zonotope Z(U) is a 7-dimensional parallelohedron if and only if the set U consists of minimal vectors of the dual lattice E{sub 7}{sup *} up to scalar multiplication, and U does not contain forbidden sets. The minimal vectors of E{sub 7} are the vectors r of the classical root system E{sub 7}. If the r{sup 2}-norm of the roots is set equal to 2, then the scalar products of minimal vectors from the dual lattice onlymore » take the values {+-}1/2. A set of minimal vectors is referred to as forbidden if it consists of six vectors, and the directions of some of these vectors can be changed so as to obtain a set of six vectors with all the pairwise scalar products equal to 1/2. Bibliography: 11 titles.« less

Comment on twinning in YNbO sub 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsunekawa, S.

1992-04-01

The paper contains statements about an analogue of ZrO{sub 2} and the twins. The analogue is suggestive in connection with yttria-partially-stabilized zirconia, but an error is found in the description of the twins in YNbO{sub 4}. Because YNbO{sub 4} performs a pure, uncoupled ferroelastic transition (thermoelastic martensitic transformation), the composition plane is determined by the following formulas 4/mF2/m: x = pz and x = {minus}z/p, p = (b + (a{sup 2} + b{sup 2}){sup 1/2})/a a = (x{sub 33} {minus} x{sub 11})/2, b = {minus} tan ({beta} {minus} 90{degrees})/2) x{sub 11} = (a{sup I} {minus} a{sub 0})/a{sub 0}, x{sub 33}more » = (c{sup 1} {minus} a{sub 0})/a{sub 0} where a{sub 0} is the lattice parameter of a in the tetragonal phase, and a{sup I} and c{sup I} are the parameters of a and c, respectively, in the monoclinic phase represented by the I-lattice. The value of p at room temperature can be estimated by using the parameters included in this paper.« less

Toxicological properties of white phosphorus (P{sub 4}): Effect of particle size

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roebuck, B.D.; Nam, S.I.

1995-12-31

The ingestion of particles of white phosphorus (P{sub 4}) causes mortality of waterfowl at Eagle River Flats, Alaska. P{sub 4} poisoning results in behaviors that attract predators. To date, the toxic properties of P{sub 4} have been characterized when P{sub 4} is dissolved in various digestible oils. Herein, the authors compare the properties of dissolved P{sub 4} to particulate P{sub 4}. Farm-reared mallards (Anas Platvrhynchos) were gavaged with P{sub 4} (12 mg/kg body weight) dissolved in oil, large particles (1.87 mm mean diameter), or small particles (0.95 mm diameter). Signs of intoxication and times to convulsion were monitored. Individuals weremore » autopsied at the onset of convulsions. P{sub 4} in digestive tracts and body fat was analyzed by gas chromatography. For all 3 treatments, the behaviors of P{sub 4} intoxication were similar to observations of wild ducks. There was no difference between treatments for onset of lethargy, vomiting, poor motor/muscle control, or the first convulsive event. At autopsy, P{sub 4} was found throughout the digestive tracts with residual quantities of approximately 20% or less of the dose. Very little of the dissolved P{sub 4} remained in gizzards; whereas, in the small and large particle groups, the gizzard contents contained 78% and 64%, respectively, of the total P{sub 4} within the digestive tracts. Tissue concentrations of P{sub 4} were small and did not appear to be a significant source of P{sub 4} to predators. In conclusion, intoxication from particles of P{sub 4} is largely not a function of the size of the particles, but rather the dose. Residual P{sub 4} in the digestive tracts represents a risk to secondary receptors. These relative risks of particulate P{sub 4} to tissue P{sub 4} are somewhat similar to poisoning from lead shot.« less

Phosphorus supply affects acclimation of photosynthesis in loblolly pine to elevated carbon dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, J.D.; Griffin, K.L.; Thomas, R.B.

1993-06-01

The interactive effects of phosphorus supply and mycorrhizal status on the acclimation of photosynthesis to elevated CO[sub 2] was investigated using 12 week old loblolly pine (Pinus taeda L.) seedlings. Seedlings were grown at either 35.5 Pa or 7 1.0 Pa CO[sub 2], with (M) or without (NM) mycorrhizal inoculum and with an adequate (High P) or a limiting (Low P) supply of phosphorus. Seedlings grown and measured at 7 1.0 Pa CO[sub 2] had significantly higher net assimilation rates (A) than seedlings grown and measured at 35.5 Pa. However, A did not vary between CO[sub 2] treatments when comparedmore » at either 35.5 or 71.0 Pa. Elevated CO[sub 2] resulted in reduced rubisco activity (V[sub cmax]) and increased RuBP regeneration capacity (J[sub max]). Low P plants had lower V[sub cmax], J[sub max] and A than High P plants. There were also significant three-way interactions between CO[sub 2] supply, phosphorus supply and mycorrhizal status on estimated values of V[sub cmax] and J[sub max]. Both V[sub cmax] and J[sub max] decreased in plants grown at elevated CO[sub 2] in all nutrient treatments except Low P, NM plants, where mean values of both parameters increased. These results indicate that plant phosphorus status affects the acclimation of photosynthesis to elevated carbon dioxide. Mycorrhizal infection ameliorated phosphorus deficiency effects on photosynthetic capacity.« less

Sign Reversal of the MN-O Bond Compressibility in La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7} Below T{sub C}: Exchange Striction in the Ferromagnetic State

DOE R&D Accomplishments Database

Argyriou, D. N.; Mitchell, J. F.; Chmaissem, O.; Short, S.; Jorgensen, J. D.; Goodenough, J. B.

1997-03-01

The crystal structure of the layered perovskite La{sub 1.2}Sr{sub 1.8}Mn{sub 2}O{sub 7} has been studied under hydrostatic pressure up to {approximately} 6 kbar, in the paramagnetic and ferromagnetic states, with neutron powder diffraction. The compressibility of the Mn-O apical bonds in the double layer of MnO{sub 6} octahedra changes sign from the paramagnetic insulator (PI) to the ferromagnetic metal (FM) state; in the Fm state the Mn-O-Mn linkage between MnO{sub 2} planes expands under applied pressure, whereas they contract in the PI state. This counterintuative behavior is interpreted in terms of exchange striction, which reflect the competition between super- and double-exchange. An increase of the Mn-moment with applied pressure in the FM state is consistent with a positive dT{sub C}/dP, as well as a cant angle {theta}{sub 0} between the magnetizations of neighboring MnO{sub 2} sheets that decreases with pressure.

Hydrogen peroxide inhibits transforming growth factor-β1-induced cell cycle arrest by promoting Smad3 linker phosphorylation through activation of Akt-ERK1/2-linked signaling pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Jiyeon; Park, Seong Ji; Jo, Eun Ji

2013-06-14

Highlights: •H{sub 2}O{sub 2} inhibits TGF-β1-induced cell cycle arrest. •H{sub 2}O{sub 2} induces Smad3 linker phosphorylation through Akt-ERK1/2 pathway. •H{sub 2}O{sub 2}-mediated suppression of TGF-β signal requires Smad3 linker phosphorylation. •This is a first report about interplay between H{sub 2}O{sub 2} and growth inhibition pathway. -- Abstract: Hydrogen peroxide (H{sub 2}O{sub 2}) functions as a second messenger in growth factor receptor-mediated intracellular signaling cascade and is tumorigenic by virtue of its ability to promote cell proliferation; however, the mechanisms underlying the growth stimulatory action of H{sub 2}O{sub 2} are less understood. Here we report an important mechanism for antagonistic effectsmore » of H{sub 2}O{sub 2} on growth inhibitory response to transforming growth factor-β1 (TGF-β1). In Mv1Lu and HepG2 cells, pretreatment of H{sub 2}O{sub 2} (0.05–0.2 mM) completely blocked TGF-β1-mediated induction of p15{sup INK4B} expression and increase of its promoter activity. Interestingly, H{sub 2}O{sub 2} selectively suppressed the transcriptional activation potential of Smad3, not Smad2, in the absence of effects on TGF-β1-induced phosphorylation of the COOH-tail SSXS motif of Smad3 and its nuclear translocation. Mechanism studies showed that H{sub 2}O{sub 2} increases the phosphorylation of Smad3 at the middle linker region in a concentration- and time-dependent manner and this effect is mediated by activation of extracellular signal-activated kinase 1/2 through Akt. Furthermore, expression of a mutant Smad3 in which linker phosphorylation sites were ablated significantly abrogated the inhibitory effects of H{sub 2}O{sub 2} on TGF-β1-induced increase of p15{sup INK4B}-Luc reporter activity and blockade of cell cycle progression from G1 to S phase. These findings for the first time define H{sub 2}O{sub 2} as a signaling molecule that modulate Smad3 linker phosphorylation and its transcriptional activity, thus providing a potential mechanism whereby H{sub 2}O{sub 2} antagonizes the cytostatic function of TGF-β1.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanc, Emil; Zając, Wojciech, E-mail: wojciech.zajac@agh.edu.pl; Lu, Li

Ceramic oxides exhibiting high lithium-ion mobility at room temperature receive broad attention as candidate electrolytes for lithium batteries. Lithium-stuffed garnets from the Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} group seem to be especially promising because of their high ionic conductivity at room temperature and their electrochemical stability. In this work, we discuss factors that affect formation of the garnet in its bulk form or in the form of thick and thin films. We demonstrate that zinc oxide can be applied as a sintering aid that facilitate the formation of the highly conducting cubic Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} garnet phase inmore » a single-step sintering procedure. Based on our experience with the single-step sintering experiments, we successfully fabricated a thick-film membrane consisting of a garnet solid electrolyte using the tape casting technique. In order to reduce the thickness of the electrolyte even further we investigated the fabrication of a thin-film Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} electrolyte by means of the pulsed laser deposition technique.« less

Purification, identification and preliminary crystallographic studies of an allergenic protein from Lathyrus sativus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qureshi, Insaf A.; Sethi, Dhruv K.; Salunke, Dinakar M., E-mail: dinakar@nii.res.in

2006-09-01

A 24 kDa protein was purified from the seeds of L. sativus by ammonium sulfate fractionation and ion-exchange chromatography. Crystals were obtained by the hanging-drop vapour-diffusion method. A 24 kDa protein was purified from the seeds of Lathyrus sativus by ammonium sulfate fractionation and ion-exchange chromatography. The N-terminal amino-acid sequence showed significant homology with the 2S albumin class of seed storage proteins. The protein showed 85% sequence homology with the seed albumin of Pisum sativum within the 40 N-terminal residues. Crystals were obtained by the hanging-drop vapour-diffusion method. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cellmore » parameters a = 43.5, b = 82.7, c = 153.4 Å.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niemi, Merja, E-mail: merja.niemi@joensuu.fi; Jänis, Janne; Jylhä, Sirpa

The high-resolution mass-spectrometric characterization, crystallization and X-ray diffraction studies of a recombinant IgE Fab fragment in complex with bovine β-lactoglobulin are reported. A D1 Fab fragment containing the allergen-binding variable domains of the IgE antibody was characterized by ESI FT–ICR mass spectrometry and crystallized with bovine β-lactoglobulin (BLG) using the hanging-drop vapour-diffusion method at 293 K. X-ray data suitable for structure determination were collected to 2.8 Å resolution using synchrotron radiation. The crystal belonged to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 67.0, b = 100.6, c = 168.1 Å. The three-dimensional structure ofmore » the D1 Fab fragment–BLG complex will provide the first insight into IgE antibody–allergen interactions at the molecular level.« less

Observation of a new high-spin isomer in {sup 94}Pd

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brock, T. S.; Nara Singh, B. S.; Wadsworth, R.

2010-12-15

A second {gamma}-decaying high-spin isomeric state, with a half-life of 197(22)ns, has been identified in the N=Z+2 nuclide {sup 94}Pd as part of a stopped-beam Rare Isotope Spectroscopic INvestigation at GSI (RISING) experiment. Weisskopf estimates were used to establish a tentative spin/parity of 19{sup -}, corresponding to the maximum possible spin of a negative parity state in the restricted (p{sub 1/2}, g{sub 9/2}) model space of empirical shell model calculations. The reproduction of the E3 decay properties of the isomer required an extension of the model space to include the f{sub 5/2} and p{sub 3/2} orbitals using the CD-Bonn potential.more » This is the first time that such an extension has been required for a high-spin isomer in the vicinity of {sup 100}Sn and reveals the importance of such orbits for understanding the decay properties of high-spin isomers in this region. However, despite the need for the extended model space for the E3 decay, the dominant configuration for the 19{sup -} state remains ({pi}p{sub 1/2}{sup -1}g{sub 9/2}{sup -3}){sub 11} x ({nu}g{sub 9/2}{sup -2}){sub 8}. The half-life of the known, 14{sup +}, isomer was remeasured and yielded a value of 499(13) ns.« less

Tantalum oxide/silicon nitride: A negatively charged surface passivation stack for silicon solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wan, Yimao, E-mail: yimao.wan@anu.edu.au; Bullock, James; Cuevas, Andres

2015-05-18

This letter reports effective passivation of crystalline silicon (c-Si) surfaces by thermal atomic layer deposited tantalum oxide (Ta{sub 2}O{sub 5}) underneath plasma enhanced chemical vapour deposited silicon nitride (SiN{sub x}). Cross-sectional transmission electron microscopy imaging shows an approximately 2 nm thick interfacial layer between Ta{sub 2}O{sub 5} and c-Si. Surface recombination velocities as low as 5.0 cm/s and 3.2 cm/s are attained on p-type 0.8 Ω·cm and n-type 1.0 Ω·cm c-Si wafers, respectively. Recombination current densities of 25 fA/cm{sup 2} and 68 fA/cm{sup 2} are measured on 150 Ω/sq boron-diffused p{sup +} and 120 Ω/sq phosphorus-diffused n{sup +} c-Si, respectively. Capacitance–voltage measurements reveal a negativemore » fixed insulator charge density of −1.8 × 10{sup 12 }cm{sup −2} for the Ta{sub 2}O{sub 5} film and −1.0 × 10{sup 12 }cm{sup −2} for the Ta{sub 2}O{sub 5}/SiN{sub x} stack. The Ta{sub 2}O{sub 5}/SiN{sub x} stack is demonstrated to be an excellent candidate for surface passivation of high efficiency silicon solar cells.« less

Hydridomethyl iridium complex

DOEpatents

Bergman, Robert G.; Buchanan, J. Michael; Stryker, Jeffrey M.; Wax, Michael J.

1989-01-01

A process for functionalizing methane comprising: (a) reacting methane with a hydridoalkyl metal complex of the formula: CpIr[P(R.sub.1).sub.3 ]H(R.sub.2) wherein Cp represents a cyclopentadienyl or alkylcyclopentadienyl radical having from 1 to 5 carbon atoms; Ir represents an iridium atom; P represents a phosphorus atom; R.sub.1 represents an alkyl group; R.sub.2 represents an alkyl group having at least two carbon atoms; and H represents a hydrogen atom, in the presence of a liquid alkane R.sub.3 H having at least three carbon atoms to form a hydridomethyl complex of the formula: CpIr[P(R.sub.1).sub.3 ]HMe where Me represents a methyl radical. (b) reacting said hydridomethyl complex with an organic halogenating agent such as a tetrahalomethane or a haloform of the formulas: CX'X"X'"X"" or CHX'X"X'"; wherein X', X", X"', and X"" represent halogens selected from bromine, iodine and chlorine, to halomethyl complex of step (a) having the formula: CpIr[P(R.sub.1).sub.3 ]MeX: (c) reacting said halomethyl complex with a mercuric halide of the formula HgX.sub.2 to form a methyl mercuric halide of the formula HgMeX; and (d) reacting said methyl mercuric halide with a molecular halogen of the formula X.sub.2 to form methyl halide.

Crystallization and preliminary X-ray analysis of the inducible lysine decarboxylase from Escherichia coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alexopoulos, E.; Kanjee, U.; Snider, J.

2010-02-11

The decameric inducible lysine decarboxylase (LdcI) from Escherichia coli has been crystallized in space groups C2 and C222{sub 1}; the Ta{sub 6}Br{sub 12}{sup 2+} cluster was used to derivatize the C2 crystals. The method of single isomorphous replacement with anomalous scattering (SIRAS) as implemented in SHELXD was used to solve the Ta{sub 6}Br{sub 12}{sup 2+}-derivatized structure to 5 {angstrom} resolution. Many of the Ta{sub 6}Br{sub 12}{sup 2+}-binding sites had twofold and fivefold noncrystallographic symmetry. Taking advantage of this feature, phase modification was performed in DM. The electron-density map of LdcI displays many features in agreement with the low-resolution negative-stain electron-densitymore » map [Snider et al. (2006), J. Biol. Chem. 281, 1532-1546].« less

[Efficacy of albendazole chitosan microspheres against Echinococcus granulosus infection in mice].

PubMed

Liang, Wen; Wang, Xin-Chun; Wu, Xiang-Wei; Zhang, Shi-Jie; Sun, Hong; Ma, Xin; Peng, Xin-Yu

2014-06-01

To observe the therapeutic effect of albendazole chitosan microspheres (ABZ-CS-MPs) on cystic echinococcosis in mice. Two hundred male kunming mice were each infected by intraperitoneal inoculation of about 5 000 viable protoscoleces of Echinococcus granulosus. Another 20 mice were kept as blank control. After 12 weeks post infection, the mice were randomly divided into four groups named as infection control group (n = 20), ABZ-CS-MPs group, albendazole liposome (L-ABZ) group, and albendazole tablet group. The latter three treatment groups were then each divided into three subgroups (n = 20) by given the dose of 37.5, 75.0, and 150.0 mg/kg for three times per week, respectively. After 12 weeks of treatment, all mice were sacrificed. The weight of hydatid cysts was measured and the inhibition rate were calculated. Mouse liver was observed. The histopathological changes of E. granulosus were observed by microscopy. The concentration of albendazole sulfoxide in plasma and liver tissues was determined by high-performance liquid chromatography. Compared with the other treatment groups, the turbidity of contained fluid, the consolidation level and calcification level of hydatid cysts in ABZ-CS-MPs group were higher. The average weight of hydatid cysts in each treatment group was lower than that of infection control group [(3.19 +/- 2.94) g] (P < 0.05). The cyst weight in 37.5, 75.0, and 150.0 mg/kg ABZ-CS-MPs group [(0.28 +/- 0.28), (0.24 +/- 0.22), and (0.20 +/- 0.19) g, respectively] was lower than that of albendazole tablet groups [(0.77 +/- 0.74), (0.55 +/- 0.42), (0.76 +/- 0.35) g] (P < 0.05). Among the same dosage groups, the inhibition rate in ABZ-CS-MPs group (from low to high dosage sub-group: 91.1%, 92.6%, and 93.7%, respectively) was highest. In 75.0 mg/kg ABZ-CS-MPs group, there were 15 mice with class I (degeneration) and II (necrosis) pathological changes of E. granulosus hydatid. The number of mice with class I and II pathological changes in each dosage ABZ-CS-MPs sub-group and L-ABZ sub-group was more than that of albendazole tablet group (P<0.05). Plasma concentration of albendazole sulfoxide in 75.0 and 150.0 mg/kg ABZ-CS-MPs sub-groups [(0.83 +/- 0.39), (0.80 +/- 0.5) microg/ml] were higher than that of L-ABZ sub-groups [(0.34 +/- 0.03), (0.43 +/- 0.15) microg/ml] and albendazole tablet sub-groups [(0.31 +/- 0.02), (0.40 +/- 0.10) microg/ml] (P < 0.05). Compared with 37.5, 75.0, and 150.0 mg/kg albendazole tablet sub-groups [(0.04 +/- 0.02), (0.07 +/- 0.04), (0.04 +/- 0.0) microg/g], the albendazole sulfoxide concentration in liver tissue was higher in ABZ-CS-MPs sub-groups [(0.33 +/- 0.06), (0.45 +/- 0.31), (0.50 +/- 0.30) microg/g] (P < 0.05). In 37.5 mg/kg dosage sub-group, the albendazole sulfoxide concentration in liver tissue in ABZ-CS-MPs group was higher than that of L-ABZ group [(0.14 +/- 0.19) microg/g] (P < 0.05). ABZ-CS-MPs can reduce the weight of hydatid cyst and increase the concentration of al-bendazole sulfoxide in plasma and liver tissue of mice.

Reliability and validity of Short Form 36 Version 2 to measure health perceptions in a sub-group of individuals with fatigue.

PubMed

Davenport, Todd E; Stevens, Staci R; Baroni, Katie; Van Ness, J Mark; Snell, Christopher R

2011-01-01

To determine the validity and reliability of Short Form 36 Version 2 (SF36v2) in sub-groups of individuals with fatigue. Thirty subjects participated in this study, including n = 16 subjects who met case definition criteria for chronic fatigue syndrome (CFS) and n = 14 non-disabled sedentary matched control subjects. SF36v2 and Multidimensional Fatigue Inventory (MFI-20) were administered before two maximal cardiopulmonary exercise tests (CPETs) administered 24 h apart and an open-ended recovery questionnaire was administered 7 days after CPET challenge. The main outcome measures were self-reported time to recover to pre-challenge functional and symptom status, frequency of post-exertional symptoms and SF36v2 sub-scale scores. Individuals with CFS demonstrated significantly lower SF36v2 and MFI-20 sub-scale scores prior to CPET. Between-group differences remained significant post-CPET, however, there were no significant group by test interaction effects. Subjects with CFS reported significantly more total symptoms (p < 0.001), as well as reports of fatigue (p < 0.001), neuroendocrine (p < 0.001), immune (p < 0.01), pain (p < 0.01) and sleep disturbance (p < 0.01) symptoms than control subjects as a result of CPET. Many symptom counts demonstrated significant relationships with SF36v2 sub-scale scores (p < 0.05). SF36v2 and MFI-20 sub-scale scores demonstrated significant correlations (p < 0.05). Various SF36v2 sub-scale scores demonstrated significant predictive validity to identify subjects who recovered from CPET challenge within 1 day and 7 days (p < 0.05). Potential floor effects were observed for both questionnaires for individuals with CFS. Various sub-scales of SF36v2 demonstrated adequate reliability and validity for clinical and research applications. Adequacy of sensitivity to change of SF36v2 as a result of a fatiguing stressor should be the subject of additional study.

Synthesis, structures, and phase transitions of barium bismuth iridium oxide perovskites Ba{sub 2}BiIrO{sub 6} and Ba{sub 3}BiIr{sub 2}O{sub 9}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ling, Chris D., E-mail: c.ling@chem.usyd.edu.a; Bragg Institute, ANSTO, PMB 1, Menai 2234; Kennedy, Brendan J.

The Ba-Bi-Ir-O system is found to contain two distinct perovskite-type phases: a rock-salt ordered double perovskite Ba{sub 2}BiIrO{sub 6}; and a 6H-type hexagonal perovskite Ba{sub 3}BiIr{sub 2}O{sub 9}. Ba{sub 2}BiIrO{sub 6} undergoes a series of symmetry-lowering phase transitions on cooling Fm3-barm->R3-barc->12/m(C2/m)->I1-bar(P1-bar), all of which are second order except the rhombohedral->monoclinic one, which is first order. The monoclinic phase is only observed in a 2-phase rhombohedral+monoclinic regime. The transition and 2-phase region lie very close to 300 K, making the room-temperature X-ray diffraction patterns extremely complex and potentially explaining why Ba{sub 2}BiIrO{sub 6} had not previously been identified and reported. Amore » solid solution Ba{sub 2}Bi{sub 1+x}Ir{sub 1-x}O{sub 6}, analogous to Ba{sub 2}Bi{sub 1+x}Ru{sub 1-x}O{sub 6}, 0<=x<=2/3, was not observed. The 6H-type phase Ba{sub 3}BiIr{sub 2}O{sub 9} undergoes a clean second-order phase transition P6{sub 3}/mmc->C2/c at 750 K, unlike 6H-type Ba{sub 3}LaIr{sub 2}O{sub 9}, the P6{sub 3}/mmc structure of which is highly strained below {approx}750 K but fails to distort coherently to the monoclinic phase. - Graphical abstract: Structure of Ba{sub 3}BiIr{sub 2}O{sub 9} at 300 K. BiO{sub 6} octahedra are purple, IrO{sub 6} octahedra are gold, and Ba atoms are green. Thermal ellipsoids at 90% probability.« less

Preparation of heterocyclic block copolymer from perfluoroalkylene oxide alpha, omega-diamidoximes

NASA Technical Reports Server (NTRS)

Ross, L. O.; Rosser, R. W.; Iannone, M. (Inventor)

1979-01-01

Diamidoxime monomers are intermolecularly and thermally condensed to form a heat and chemical resistant polymer containing 1,2,4-oxadiazole linkages with identical bivalent organic radicals or any combination of bivalent organic radicals selected from the group consisting of -(CX(sub 2))p-, wherein P ranges from 2 to 8 when X is fluorine and 2 to 18 when X is hydrogen, chlorine, nitro or aryl; arylene; and an oligometric or polymeric radical prepared by reacting a dicarboxylic acid halide with a fluorinated epoxide and having the formula: (CFY(OCF(sub 2)CFY)sub m)O(CX(sub 2))(sub p)O(CFYCF(sub 2)O)(sub n)CFY wherein Y is flourine or tryifluoromethyl, X is nitro, aryl, hydrogen, chlorine or fluorine, preferably the latter, p ranges from 1 to 18 and m+n ranges from 2 to 7.

Limits on superconductivity-related magnetization in Sr 2RuO 4 and PrOs 4Sb 12 from scanning SQUID microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moler, Kathryn

2010-08-26

We present scanning SQUID microscopy data on the superconductors Sr{sub 2}RuO{sub 4} (T{sub c} = 1.5 K) and PrOs{sub 4}Sb{sub 12} (T{sub c} = 1.8 K). In both of these materials, superconductivity-related time-reversal symmetry-breaking fields have been observed by muon spin rotation; our aim was to visualize the structure of these fields. However in neither Sr{sub 2}RuO{sub 4} nor PrOs{sub 4}Sb{sub 12} do we observe spontaneous superconductivity-related magnetization. In Sr{sub 2}RuO{sub 4}, many experimental results have been interpreted on the basis of a p{sub x} {+-} ip{sub y} superconducting order parameter. This order parameter is expected to give spontaneous magneticmore » induction at sample edges and order parameter domain walls. Supposing large domains, our data restrict domain wall and edge fields to no more than {approx}0.1% and {approx}0.2% of the expected magnitude, respectively. Alternatively, if the magnetization is of the expected order, the typical domain size is limited to {approx}30 nm for random domains, or {approx} 500 nm for periodic domains.« less

Unified gauge theories with right-handed currents and heavy fermions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohapatra, R.N.

Gauge models with heavy fermions and right-handed currents are discussed based on the gauge groups SU(2)/subA/ x U(1) x SU(4) ', SU(2)/subA/ x SU(2)/subB/ x SU(4) ', and SU(4) x SU(4) ' and are constructed so as to lead to the $delta$I = 1/2 rule. SU(4) x SU(4) ' is advocated as the ultimate unifying gauge group of nature, and it is shown how at various stages of spontaneous breakdown both the SU(2)/subA/ x SU(2)/subB/ x SU(4) ' and SU(2)/subA/ x U(1) x SU(4) ' groups manifest themselves. It is also shown that CP violation takes an interesting complexion inmore » these models and leads to exactly the relations eta/sub +//sub -/ approx. = eta$sub 00$ in K/subL/ $Yields$ 2$pi$ decays. Furthermore, it is shown that the magnitude of CP violation is related to gauge interactions that violate the heavy quark degeneracy. (AIP)« less

Crystallization, Preliminary X-ray Analysis and Biophysical Characterization of HPr Kinase/Phosphatase of Mycoplasma pneumoniae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinhauer, K.

2002-01-01

The Mycoplasma pneumoniae HPr kinase/phosphatase (HPrK/P) is a member of a large family of enzymes which are central to carbon regulation in Gram-positive bacteria. The full-length M. pneumonia HPrK/P was crystallized from solutions of polyethylene glycol 8000 and KCl or NaCl which also contained the non-hydrolysable ATP analog adenosine 5'-[{beta},{gamma}-methylene]triphosphate (AMPPCP). The crystals belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 117.1, b = 127.7, c = 170.7 {angstrom}. A complete X-ray intensity data set has been collected and processed to 2.50 {angstrom} resolution. The slow self-rotation function revealed the presence of amore » sixfold axis. Dynamic light-scattering (DLS) experiments indicated a molecular weight of 197 kDa for HPrK/P in the absence of AMPPCP and of 217 kDa in the presence of the ATP analog. Thus, the biophysical and crystallographic data suggest that HPrK/P is a functional hexamer that undergoes an ATP-binding-induced conformational change.« less

Turbulence-induced relative velocity of dust particles. III. The probability distribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Liubin; Padoan, Paolo; Scalo, John, E-mail: lpan@cfa.harvard.edu, E-mail: ppadoan@icc.ub.edu, E-mail: parrot@astro.as.utexas.edu

2014-09-01

Motivated by its important role in the collisional growth of dust particles in protoplanetary disks, we investigate the probability distribution function (PDF) of the relative velocity of inertial particles suspended in turbulent flows. Using the simulation from our previous work, we compute the relative velocity PDF as a function of the friction timescales, τ{sub p1} and τ{sub p2}, of two particles of arbitrary sizes. The friction time of the particles included in the simulation ranges from 0.1τ{sub η} to 54T {sub L}, where τ{sub η} and T {sub L} are the Kolmogorov time and the Lagrangian correlation time of themore » flow, respectively. The relative velocity PDF is generically non-Gaussian, exhibiting fat tails. For a fixed value of τ{sub p1}, the PDF shape is the fattest for equal-size particles (τ{sub p2} = τ{sub p1}), and becomes thinner at both τ{sub p2} < τ{sub p1} and τ{sub p2} > τ{sub p1}. Defining f as the friction time ratio of the smaller particle to the larger one, we find that, at a given f in (1/2) ≲ f ≲ 1, the PDF fatness first increases with the friction time τ{sub p,h} of the larger particle, peaks at τ{sub p,h} ≅ τ{sub η}, and then decreases as τ{sub p,h} increases further. For 0 ≤ f ≲ (1/4), the PDF becomes continuously thinner with increasing τ{sub p,h}. The PDF is nearly Gaussian only if τ{sub p,h} is sufficiently large (>>T {sub L}). These features are successfully explained by the Pan and Padoan model. Using our simulation data and some simplifying assumptions, we estimated the fractions of collisions resulting in sticking, bouncing, and fragmentation as a function of the dust size in protoplanetary disks, and argued that accounting for non-Gaussianity of the collision velocity may help further alleviate the bouncing barrier problem.« less

Group 4 metal mono-dicarbollide piano stool complexes. Synthesis, structure, and reactivity of ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})M(NR{sub 2}){sub 2}(NHR{sub 2}) (M = Zr, R = Et; M = Ti, R = Me, Et)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowen, D.E.; Jordan, R.F.; Rogers, R.D.

1995-08-01

The amine elimination reaction of C{sub 2}B{sub 9}H{sub 13} and Zr(NEt{sub 2}){sub 4} yields the mono-dicarbollide complex ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Zr(NEt{sub 2}){sub 2}(NHEt{sub 2}), (1), which has been shown to adopt a three-legged piano stool structure by X-ray crystallography. Crystal data for 1: space group P2{sub 1}/c, a = 10.704(4) A, b = 11.066(3) A, c = 20.382(8) A, {beta} = 99.20(3){degree}, V = 2383(1) A{sup 3}, Z = 4. Complex 1 undergoes facile ligand substitution by THF and 4-picoline, yielding ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Zr(NEt{sub 2}){sub 2}-(THF) (2) and ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Zr(NEt{sub 2}){sub 2}(4-picoline){sub 2} (3).more » Compound 3 exists as the four-coordinate species ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Zr(NEt{sub 2}){sub 2}(4-picoline) in CH{sub 2}Cl{sub 2} solution. Complex 1 reacts selectively with 2 equiv of [NH{sub 2}ET{sub 2}]Cl, yielding ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})ZrCl{sub 2}(NHEt{sub 2}){sub 2} (4). Similarly, the reaction of C{sub 2}B{sub 9}H{sub 13} and Ti(NR{sub 2}){sub 4} yields ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})Ti(NR{sub 2}){sub 2}(NHR{sub 2}) (5, R = Me; 6, R = Et). Compounds 1-6 are potential precursors to group 4 metal ({eta}{sup 5}-C{sub 2}B{sub 9}H{sub 11})MR{sub 2}L{sub n} alkyl species. 25 refs., 3 figs., 3 tabs.« less

Emission Analysis Of Pr{sup 3+}: PVP And Nd{sup 3+}: PVP Films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sivaiah, K.; Buddhudu, S.

Here we report on the results concerning the absorption and emission spectra of RE{sup 3+} (Pr{sup 3+} or Nd{sup 3+}) doped PVP polymer films. The absorption spectrum of Pr{sup 3+}: PVP polymer film has shown three absorption bands at 444 nm ({sup 3}H{sub 4{yields}}{sup 3}P{sub 2}), 469nm ({sup 3}H{sub 4{yields}}{sup 3}P{sub 1}) and 481nm ({sup 3}H{sub 4{yields}}{sup 3}P{sub 0}). From the Pr{sup 3+}: PVP polymer film, an emission at 603 nm ({sup 1}D{sub 2{yields}}{sup 3}H{sub 4}) has been observed with an excitation at 443 nm ({sup 3}H{sub 4{yields}}{sup 3}P{sub 2}). The absorption spectrum of Nd{sup 3+}: PVP polymer film hasmore » exhibited eleven absorption bands at 324 nm, 383 nm, 432 nm, 462 nm, 511 nm, 526 nm, 580 nm, 686 nm, 746 nm, 799 nm, and 869 nm which are assigned to the electronic transitions of {sup 4}I{sub 9/2{yields}}{sup 4}D{sub 7/2}, {sup 4}I{sub 9/2{yields}}{sup 2}D{sub 3/2}, {sup 4}I{sub 9/2{yields}}{sup 4}P{sub 1/2}, {sup 4}I{sub 9/2{yields}}{sup 4}G{sub 11/2}, {sup 4}I{sub 9/2{yields}}{sup 4}G{sub 9/2}, {sup 4}I{sub 9/2{yields}}{sup 4}G{sub 7/2}, {sup 4}I{sub 9/2{yields}}{sup 4}G{sub 5/2}, {sup 4}I{sub 9/2{yields}}{sup 2}F{sub 9/2}, {sup 4}I{sub 9/2{yields}}{sup 2}F{sub 7/2}, {sup 4}I{sub 9/2{yields}}{sup 2}H{sub 9/2} and {sup 4}I{sub 9/2{yields}}{sup 4}F{sub 3/2} respectively. From the Nd{sup 3+}: PVP polymer film, an emission transition has been measured at 1055 nm ({sup 4}F{sub 3/2{yields}}{sup 4}I{sub 11/2}) with an excitation at 324 nm ({sup 4}I{sub 9/2{yields}}{sup 4}D{sub 7/2}). For the host polymer film, structural properties have been studied from the measurement of XRD, FTIR, Raman spectra. For this film thermal properties have also been investigated from the measured profiles of TGA-DTA.« less

A new triclinic modification of the pyrochlore-type KOs{sub 2}O{sub 6} superconductor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katrych, S.; Gu, Q.F.; Bukowski, Z.

2009-03-15

A new modification of KOs{sub 2}O{sub 6}, the representative of a new structural type (Pearson symbol aP18, a=5.5668(1) A, b=6.4519(2) A, c=7.2356(2) A, {alpha}=65.377(3){sup o}, {beta}=70.572(3){sup o}, {gamma}=75.613(2){sup o} space group P-1, no. 2 was synthesized employing high pressure technique. Its structure was determined by single-crystal X-ray diffraction. The structure can be described as two OsO{sub 6} octahedral chains relating to each other through inversion and forming big voids with K atoms inside. Quantum chemical calculations were performed on the novel compound and structurally related cubic compound. High-pressure X-ray study showed that cubic KOs{sub 2}O{sub 6} phase was stable upmore » to 32.5(2) GPa at room temperature. - Graphical abstract: A new modification of KOs{sub 2}O{sub 6}, the representative of a new structural type (Pearson symbol aP18, a=5.5668(1) A, b=6.4519(2) A, c=7.2356(2) A, {alpha}=65.377(3){sup o}, {beta}=70.572(3){sup o}, {gamma}=75.613(2){sup o} space group P-1, no. 2 was synthesized employing high pressure technique. The structure can be described as two OsO{sub 6} octahedral chains relating to each other through inversion and forming big voids with K atoms inside.« less

Inhibition of hydrogen sulfide on the proliferation of vascular smooth muscle cells involved in the modulation of calcium sensing receptor in high homocysteine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yuwen; Wang, Xiyao; Liang, Xiaohui

Hyperhomocysteinemia induces the proliferation of vascular smooth muscle cells (VSMCs). Hydrogen sulfide (H{sub 2}S) inhibits the phenotype switch of VSMCs and calcium-sensing receptor (CaSR) regulated the production of endogenous H{sub 2}S. However, whether CaSR inhibits the proliferation of VSMCs by regulating the endogenous cystathionine-gamma-lyase (CSE, a major enzyme that produces H{sub 2}S) pathway in high homocysteine (HHcy) has not been previously investigated. The intracellular calcium concentration, the concentration of H{sub 2}S, the cell viability, the proliferation and the expression of proteins of cultured VSMCs from rat thoracic aortas were measured, respectively. The results showed that the [Ca{sup 2+}]{sub i} andmore » the expression of p-CaMK and CSE increased upon treatment with CaSR agonist. In HHcy, the H{sub 2}S concentration decrease, the proliferation and migration rate increased, the expression of Cyclin D1, PCNA, Osteopontin and p-Erk1/2 increased while the α-SM actin, P21{sup Cip/WAK−1} and Calponin decreased. The CaSR agonist or exogenous H{sub 2}S significantly reversed the changes of VSMCs caused by HHcy. In conclusion, our results demonstrated that CaSR regulate the endogenous CSE/H{sub 2}S is related to the PLC-IP{sub 3} receptor and CaM signal pathways which inhibit the proliferation of VSMCs, and the latter is involved in the Erk1/2 dependent signal pathway in high homocysteine. - Highlights: • CaSR activation increased the production of endogenous H{sub 2}S in high homocysteine VSMCs. • CaSR modulated the CSE/H{sub 2}S are related to the PLC-IP{sub 3}R and Ca{sup 2+}-CaM signal pathways. • Inhibition of H{sub 2}S on the proliferation of VSMCs is involved in the Erk1/2 pathway. • Explore the potential roles of CaSR in regulating VSMCs proliferation in high homocysteine.« less

Hybrid Diffusion Imaging in Mild Traumatic Brain Injury.

PubMed

Wu, Yu-Chien; Mustafi, Sourajit Mitra; Harezlak, Jaroslaw; Kodiweera, Chandana; Flashman, Laura A; McAllister, Thomas

2018-05-22

Mild traumatic brain injury (mTBI) is an important public health problem. Although conventional medical imaging techniques can detect moderate-to-severe injuries, they are relatively insensitive to mTBI. In this study, we used hybrid diffusion imaging (HYDI) to detect white-matter alterations in nineteen patients with mTBI and 23 other trauma-control patients. Within 15 days (SD=10) of brain injury, all subjects underwent magnetic-resonance HYDI and were assessed with battery of neuropsychological tests of sustained attention, memory, and executive function. Tract-based spatial statistics (TBSS) were used for voxelwise statistical analyses within the white-matter skeleton to study between-group differences in diffusion metrics, within-group correlations between diffusion metrics and clinical outcomes, and between group interaction effects. The advanced diffusion imaging techniques including neurite orientation dispersion and density imaging (NODDI) and q-space analyses appeared to be more sensitive then classic diffusion tensor imaging (DTI). Only NODDI-derived intra-axonal volume fraction (V_ic) demonstrated significant group differences (i.e., 5% to 9% lower in the injured brain). Within the mTBI group, V_ic and a q-space measure, P₀, correlated with 6 of 10 neuropsychological tests including measures of attention, memory, and executive function. In addition, the direction of correlations differed significantly between the groups (R² > 0.71 and P_interation < 0.03). Specifically, in the control group, higher V_ic and P₀ were associated with better performances on clinical assessments, whereas in the mTBI group, higher V_ic and P₀ were associated with worse performances with correlation coefficients > 0.83. In summary, the NODDI-derived axonal density index and q-space measure for tissue restriction demonstrated superior sensitivity to white-matter changes shortly after mTBI. These techniques hold promise as a neuroimaging biomarker for mTBI.

Synthesis and structures of new niobium cluster compounds with pyridinium cations: (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}].EtOH (Pyr: pyridine, Et: ethyl) and the cubic modification of (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flemming, Anke; Hoppe, Alessandra; Koeckerling, Martin

2008-10-15

Slow crystallization of (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}] from hot ethanol solution affords triclinic (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}].EtOH. Treatment of [Nb{sub 6}Cl{sub 14}(H{sub 2}O){sub 4}].4H{sub 2}O with pyridine in a methanol solution gives the second title compound, the cubic modification of (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}]. Both structures were determined by single crystal X-ray diffraction, (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}].EtOH: P1-bar , a=9.3475(3), b=9.3957(3), c=10.8600(3) A, {alpha}=82.582(1){sup o}, {beta}=78.608(1){sup o}, and {gamma}=78.085(1){sup o}, Z=1, R{sub 1}(F)/wR{sub 2}(F{sup 2})=0.0254/0.0573, cub.-(PyrH){sub 2}[Nb{sub 6}Cl{sub 18}]: Fd3-bar m, a=19.935(2) A, Z=8, R{sub 1}(F)/wR{sub 2}(F{sup 2})=0.0557/0.1796. The cluster compounds contain isolated, molecular [Nb{sub 6}Cl{sup i}{sub 12}Cl{sup a}{sub 6}]{supmore » 2-} cluster anions with an octahedron of metal atoms edge bridged by chlorido ligands with additional ones on all the six exo positions. These cluster anions are separated by the pyridinium cations and ethanol solvent molecules, respectively. For the cubic modification of (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}], a structural comparison is given to the known rhombohedral modification using the group-subgroup relations as expressed by a Baernighausen tree. - Graphical abstract: The synthesis and structure of a second cubic modification of (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}] and of the new (PyrH){sub 2}[Nb{sub 6}Cl{sub 18}].EtOH are reported, both of which contain isolated niobium halide cluster anions with an octahedral core of metal atoms.« less

Syntheses, crystal structures and Raman spectra of Ba(BF{sub 4})(PF{sub 6}), Ba(BF{sub 4})(AsF{sub 6}) and Ba{sub 2}(BF{sub 4}){sub 2}(AsF{sub 6})(H{sub 3}F{sub 4}); the first examples of metal salts containing simultaneously tetrahedral BF{sub 4}{sup -} and octahedral AF{sub 6}{sup -} anions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lozinsek, Matic; Bunic, Tina; Goreshnik, Evgeny, E-mail: evgeny.goreshnik@ijs.s

2009-10-15

In the system BaF{sub 2}/BF{sub 3}/PF{sub 5}/anhydrous hydrogen fluoride (aHF) a compound Ba(BF{sub 4})(PF{sub 6}) was isolated and characterized by Raman spectroscopy and X-ray diffraction on the single crystal. Ba(BF{sub 4})(PF{sub 6}) crystallizes in a hexagonal P6-bar2m space group with a=10.2251(4) A, c=6.1535(4) A, V=557.17(5) A{sup 3} at 200 K, and Z=3. Both crystallographically independent Ba atoms possess coordination polyhedra in the shape of tri-capped trigonal prisms, which include F atoms from BF{sub 4}{sup -} and PF{sub 6}{sup -} anions. In the analogous system with AsF{sub 5} instead of PF{sub 5} the compound Ba(BF{sub 4})(AsF{sub 6}) was isolated and characterized.more » It crystallizes in an orthorhombic Pnma space group with a=10.415(2) A, b=6.325(3) A, c=11.8297(17) A, V=779.3(4) A{sup 3} at 200 K, and Z=4. The coordination around Ba atom is in the shape of slightly distorted tri-capped trigonal prism which includes five F atoms from AsF{sub 6}{sup -} and four F atoms from BF{sub 4}{sup -} anions. When the system BaF{sub 2}/BF{sub 3}/AsF{sub 5}/aHF is made basic with an extra addition of BaF{sub 2}, the compound Ba{sub 2}(BF{sub 4}){sub 2}(AsF{sub 6})(H{sub 3}F{sub 4}) was obtained. It crystallizes in a hexagonal P6{sub 3}/mmc space group with a=6.8709(9) A, c=17.327(8) A, V=708.4(4) A{sup 3} at 200 K, and Z=2. The barium environment in the shape of tetra-capped distorted trigonal prism involves 10 F atoms from four BF{sub 4}{sup -}, three AsF{sub 6}{sup -} and three H{sub 3}F{sub 4}{sup -} anions. All F atoms, except the central atom in H{sub 3}F{sub 4} moiety, act as mu{sub 2}-bridges yielding a complex 3-D structural network. - Graphical abstract: The first three compounds, containing simultaneously tetrahedral BF{sub 4}{sup -} and octahedral AF{sub 6}{sup -} (A=P, As) anions have been synthesized and characterized by Raman spectroscopy and X-ray single crystal diffraction. In the system BaF{sub 2}/BF{sub 3}/PF{sub 5}/anhydrous hydrogen fluoride (aHF) the compound Ba(BF{sub 4})(PF{sub 6}) was isolated. In the analogous system with AsF{sub 5} instead of PF{sub 5} the compound Ba(BF{sub 4})(AsF{sub 6}) was obtained. When the system BaF{sub 2}/BF{sub 3}/AsF{sub 5}/aHF is made basic with an extra addition of BaF{sub 2}, the compound Ba{sub 2}(BF{sub 4}){sub 2}(AsF{sub 6})(H{sub 3}F{sub 4}) was prepared.« less

Protein kinase C (PKC) phosphorylates human platelet inositol trisphosphate 5/sup +/-/-phosphomonoesterase (IP/sub 3/ 5'-p'tase) increasing phosphatase activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Connolly, T.M.; Majerus, P.W.

1986-05-01

Phosphoinositide breakdown in response to thrombin stimulation of human platelets generates messenger molecules that activate PKC (diglyceride) and mobilize Ca/sup + +/ (inositol tris-phosphates). The water soluble products of phospholipase C-mediated metabolism of phosphatidylinositol 4,5-diphosphate are inositol 1,4,5 P/sub 3/ (IP/sub 3/) and inositol 1:2-cyclic 4,5 P/sub 3/ (cIP/sub 3/). A specific phosphatase, IP/sub 3/ 5'-p'tase, cleaves the 5 phosphate from IP/sub 3/ or cIP/sub 3/ to form IP/sub 2/ or cIP/sub 2/ and P/sub i/, none of which mobilizes Ca/sup + +/. Thus, the IP/sub 3/ 5'-p'tase may regulate cellular responses to IP/sub 3/ or cIP/sub 3/. The authorsmore » find that IP/sub 3/ 5'-p'tase isolated from human platelets is phosphorylated by rat brain PKC, resulting in a 4-fold increase in IP/sub 3/ 5'-p'tase activity. The authors phosphorylated IP/sub 3/ 5'-p'tase using ..gamma.. /sup 32/P-ATP and found that the labeled enzyme comigrated on SDS-PAGE with the previously described 40K protein phosphorylated in response to thrombin stimulation of platelets. The similarity of the PKC-phosphorylated IP/sub 3/ 5'-p'tase observed in vitro and the thrombin-stimulated phosphorylated 40K protein known to be phosphorylated by PKC in vivo, suggests that these proteins may be the same. These results suggest that platelet Ca/sup + +/ mobilization maybe regulated by PKC phosphorylation of the IP/sub 3/ 5'-p'tase and can explain the observation that phorbol ester treatment of intact human platelets results in decreased production of IP/sub 3/ and decreased Ca/sup + +/ mobilization upon subsequent thrombin addition.« less

Dynamical interferences to probe short-pulse photoassociation of Rb atoms and stabilization of Rb{sub 2} dimers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mur-Petit, Jordi; Luc-Koenig, Eliane; Masnou-Seeuws, Francoise

2007-06-15

We analyze the formation of Rb{sub 2} molecules with short photoassociation pulses applied to a cold {sup 85}Rb sample. A pump laser pulse couples a continuum level of the ground electronic state X {sup 1}{sigma}{sub g}{sup +} with bound levels in the 0{sub u}{sup +}(5S+5P{sub 1/2}) and 0{sub u}{sup +}(5S+5P{sub 3/2}) vibrational series. The nonadiabatic coupling between the two excited channels induces time-dependent beatings in the populations. We propose to take advantage of these oscillations to design further laser pulses that probe the photoassociation process via photoionization or that optimize the stabilization in deep levels of the ground state.

15-Deoxy-{delta}{sup 12,14}-prostaglandin J{sub 2} down-regulates CXCR4 on carcinoma cells through PPAR{gamma}- and NF{kappa}B-mediated pathways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richard, Cynthia Lee; Lowthers, Erica Lauren; Blay, Jonathan

2007-10-01

The chemokine receptor CXCR4 plays a key role in the metastasis of colorectal cancer and its growth at metastatic sites. Here, we have investigated the mechanisms by which CXCR4 on cancer cells might be regulated by eicosanoids present within the colorectal tumor microenvironment. We show that prostaglandins PGE{sub 2}, PGA{sub 2}, PGD{sub 2}, PGJ{sub 2} and 15dPGJ{sub 2} each down-regulates CXCR4 receptor expression on human colorectal carcinoma cells to differing degrees. The most potent of these were PGD{sub 2} and its metabolites PGJ{sub 2} and 15dPGJ{sub 2}. Down-regulation was most rapid with the end-product 15dPGJ{sub 2} and was accompanied bymore » a marked reduction in CXCR4 mRNA. 15dPGJ{sub 2} is known to be a ligand for the nuclear receptor PPAR{gamma}. Down-regulation of CXCR4 was also observed with the PPAR{gamma} agonist rosiglitazone, while 15dPGJ{sub 2}-induced CXCR4 down-regulation was substantially diminished by the PPAR{gamma} antagonists GW9662 and T0070907. These data support the involvement of PPAR{gamma}. However, the 15dPGJ{sub 2} analogue CAY10410, which can act on PPAR{gamma} but which lacks the intrinsic cyclopentenone structure found in 15dPGJ{sub 2}, down-regulated CXCR4 substantially less potently than 15dPGJ{sub 2}. The cyclopentenone grouping is known to inhibit the activity of NF{kappa}B. Consistent with an additional role for NF{kappa}B, we found that the cyclopentenone prostaglandin PGA{sub 2} and cyclopentenone itself could also down-regulate CXCR4. Immunolocalization studies showed that the cellular context was sufficient to trigger a focal nuclear pattern of NF{kappa}B p50 and that 15dPGJ{sub 2} interfered with this p50 nuclear localization. These data suggest that 15dPGJ{sub 2} can down-regulate CXCR4 on cancer cells through both PPAR{gamma} and NF{kappa}B. 15dPGJ{sub 2}, present within the tumor microenvironment, may act to down-regulate CXCR4 and impact upon the overall process of tumor expansion.« less

Synthesis, characterization, and fluorescent properties of two Pb(II) complexes: {l_brace}[Pb(hca){sub 2}.DMF].DMF{r_brace} {sub {infinity}} and [Pb(hca){sub 2}(phen).DMF]{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu Qingfeng; Zhou Qiuxuan; Lu Jianmei

2007-01-15

Two novel Pb(II) complexes, {l_brace}[Pb(hca){sub 2}.DMF].DMF{r_brace} {sub {infinity}} and [Pb(hca){sub 2}(phen).DMF]{sub 2} (hca=trans-4-hydroxycinnamic group), were obtained by solid-phase reactions of PbAc{sub 2} and Hhca and PbAc{sub 2}, Hhca, and phen, respectively, and characterized by spectroscopy. X-ray crystallography analysis reveals that complex 1, {l_brace}[Pb(hca){sub 2}.DMF].DMF{r_brace} {sub {infinity}} , adopts a 2-dimensional structure through the weak interactions of Pb and O atoms and that complex 2, [Pb(hca){sub 2}(phen).DMF]{sub 2}, shows a discrete dimeric structure, in which hydrogen bonds link the dimers into a 2D network. Both complexes 1 and 2 show visible fluorescence and the intensity is stronger than that of themore » ligand. More interestingly, the intensity of emission was increased at least fivefolds when the pH of the solution was adjusted to alkalinity. This can be attributed to that the deprotonization of phenolic group enhancing the conjugation of the ligand hca. These results indicate that this method may be an effective way to increase the emission intensity of similar complexes. - Graphical abstract: Two novel Pb(II) complexes: {l_brace}[Pb(hca){sub 2}.DMF].DMF{r_brace}{sub {infinity}} and [Pb(hca){sub 2}(phen).DMF]{sub 2}, (hca = trans-4-hydroxycinnamic anion) were obtained and characterized. Their structures are also determined by X-ray crystal analysis. Both of complexes in DMF solution show visible fluorescence and the intensity is stronger than that of ligand. Their emission intensities are increased greatly in an alkaline solution of pH 8, which is due to the enhancement of the planar conjugation of ligand hca with the deprotonate of the phenolic group.« less

First-principles study lone-pair effects of Sb (III)-S chromophore influence on SHG response in quaternary potassium containing silver antimony sulfides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Junben; School of Physics Science and Technology, Xinjiang University, Urumqi 830046; Su, Xin

2017-05-15

First-principles studies of the geometric structures, electronic structures and optical properties of non-centrosymmetrical (NCS) KAg{sub 2}SbS{sub 4}, K{sub 2}AgSbS{sub 4} and K{sub 2}Ag{sub 3}Sb{sub 3}S{sub 7} and centrosymmetrical (CS) KAg{sub 2}SbS{sub 3} and K{sub 3}Ag{sub 9}Sb{sub 4}S{sub 12} have been performed by means of density functional theory. It is indicated that although they have similarity in their anionic groups and, the electronic structures, prominent features of the optical anisotropy or second-order nonlinear optical (NLO) susceptibilities are apparently different. The calculated birefringences are 0.0537, 0.0343, 0.1324, 0.2217 and 0.0604 which are attributed to the different anionic groups [SbS{sub 3}] and trianglesmore » [AgS{sub 3}]. Also, the calculated NLO responses are about 0.5×, 1.0× and 2.0× times than that commercial AgGaS{sub 2} (AGS, d{sub 36}=11 pm/V) for K{sub 2}AgSbS{sub 4}, KAg{sub 2}SbS{sub 4} and K{sub 2}Ag{sub 3}Sb{sub 3}S{sub 7}, respectively. In comparison with the absolute magnitude of second harmonic generation (SHG) coefficients, the order K{sub 2}Ag{sub 3}Sb{sub 3}S{sub 7}>KAg{sub 2}SbS{sub 4}>K{sub 2}AgSbS{sub 4} is clearly established in the SHG response. Further analysis based on the real-space atom-cutting method reveals that the main sources of the SHG properties of these compounds are from the Sb-S group, especially K{sub 2}Ag{sub 3}Sb{sub 3}S{sub 7} is mainly attributed to the lone pair stereochemical activity of Sb (III)-S group. - Graphical abstract: Compounds K{sub 2}AgSbS{sub 4}, KAg{sub 2}SbS{sub 4} and K{sub 2}Ag{sub 3}Sb{sub 3}S{sub 7} exhibit second-order NLO response: 15×, 30× and 62× times than that KDP (KH{sub 2}PO{sub 4}, d{sub 36}=0.39 pm/V), respectively. First-principles methods reveal that the large SHG response of K{sub 2}Ag{sub 3}Sb{sub 3}S{sub 7} is dominated by the Sb-S chromophore with lone pairs.« less

High-pressure behaviour of Cs{sub 2}V{sub 3}O{sub 8} fresnoite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grzechnik, Andrzej, E-mail: grzechnik@xtal.rwth-aachen.de; Yeon, Jeongho; Zur Loye, Hans-Conrad

2016-06-15

Crystal structure of Cs{sub 2}V{sub 3}O{sub 8} fresnoite (P4bm, Z=2) has been studied using single-crystal X-ray diffraction in a diamond anvil cell to 8.6 GPa at room temperature. Cs{sub 2}V{sub 3}O{sub 8} undergoes a reversible first-order phase transition at about 4 GPa associated with anomalies in the pressure dependencies of the lattice parameters and unit-cell volume but without any symmetry change. Both structures consist of layers of corner-sharing V{sup 5+}O{sub 4} tetrahedra and V{sup 4+}O{sub 5} tetragonal pyramids separated by the Cs{sup +} cations located between the layers. At low pressures, the compression has little effect on the polarity ofmore » the structure. Above 4 GPa, the pseudosymmetry with respect to the corresponding centrosymmetric space group P4/mbm abruptly increases. The effects of external pressure and of the A{sup +} cation substitution in the vanadate fresnoites A{sub 2}V{sub 3}O{sub 8} (A{sup +}: K{sup +}, Rb{sup +}, NH{sub 4}{sup +}, Cs{sup +}) are discussed. - Graphical abstract: Non-centrosymmetric Cs{sub 2}V{sub 3}O{sub 8} undergoes a reversible first-order phase transition at about 4 GPa associated with an abrupt change of the pseudosymmetry with respect to the centrosymmetric space group P4/mbm. Display Omitted - Highlights: • High-pressure behaviour of vanadate fresnoites depends on alkali metal cations. • The size of the alkali metal cation determines whether the high-pressure phase is centrosymmetric. • No incommensurate structures are observed upon compression.« less

Crystal structures of the ionic conductors Bi{sub 46}M{sub 8}O{sub 89} (M=P, V) related to the fluorite-type structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darriet, J.; Launay, J.C.; Zuniga, F.J.

2005-06-15

The crystal structures of the two oxides Bi{sub 46}M{sub 8}O{sub 89} (M=P, V) have been solved from single crystals X-ray data at room temperature. Bi{sub 46}P{sub 8}O{sub 89} crystallizes in the monoclinic symmetry (space group C2/m) with the cell parameters a=19.6073(4)A, b=11.4181(4)A, c=21.1119(4)A and {beta}=112.14(3){sup o}. The symmetry of Bi{sub 46}V{sub 8}O{sub 89} is also monoclinic but the space group is P2{sub 1}/c with the unit-cell parameters: a=20.0100(4)A, b=11.6445(4)A, c=20.4136(4)A and {beta}=107.27(3){sup o}. Both structures derive from an oxygen deficient fluorite-type structure where the Bi and M cations (M=P, V) are ordered in the framework. The structures are characterised bymore » isolated MO{sub 4} tetrahedra (M=P, V) which contradicts the previous results. The difference between the two structures is only due to a different order of the M atoms (M=P, V) in the fluorite-type superstructure. It will be shown that some oxygen sites are partially occupied in both structures which can explain the ion conduction properties of these phases. A structural building principle will be proposed that can explain the large domain of solid solution related to the fluorite-type observed in both systems.« less

Rotationally resolved photoelectron spectroscopy of n-H/sub 2/, p-H/sub 2/, HD, and D/sub 2/

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pollard, J.E.; Trevor, D.J.; Reutt, J.E.

1982-07-01

The 584 A photoelectron spectra of n-H/sub 2/, p-H/sub 2/, HD, and D/sub 2/ were recorded at a resolution of 11 meV FWHM using a supersonic molecular beam source. Spectra were taken at several stagnation temperatures and pressures in order to vary the rotational population distribution in the beam with a corresponding variation in the relative intensities of the rotational transitions. Many of the Q-branch components were resolved for the first time. ..delta..G(v+1/2) and B/sub v/ values were measured for all observed vibrational states of H/sup +//sub 2/, HD/sup +/, and D/sup +//sub 2/ and were used to determined themore » ionic vibrational and rotational constants: ..omega../sub e/, ..omega../sub e/x/sub e/, ..omega../sub e/y/sub e/, ..omega../sub e/z/sub e/, B/sub e/, and ..cap alpha../sub e/. The results represent a substantial improvement over previous experimental determinations and were found to be consistent with the available theoretical rotation-vibration energy levels. The measurement of the intensity distribution of photoelectrons as a function of vibrational states yielded photoionization cross sections which were in good agreement with the theoretical values calculated by O'Niel and Reinhardt.« less

Cerenkov emission of acoustic phonons electrically generated from three-dimensional Dirac semimetals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubakaddi, S. S., E-mail: sskubakaddi@gmail.com

2016-05-21

Cerenkov acoustic phonon emission is theoretically investigated in a three-dimensional Dirac semimetal (3DDS) when it is driven by a dc electric field E. Numerical calculations are made for Cd{sub 3}As{sub 2} in which mobility and electron concentration are large. We find that Cerenkov emission of acoustic phonons takes place when the electron drift velocity v{sub d} is greater than the sound velocity v{sub s}. This occurs at small E (∼few V/cm) due to large mobility. Frequency (ω{sub q}) and angular (θ) distribution of phonon emission spectrum P(ω{sub q}, θ) are studied for different electron drift velocities v{sub d} (i.e., differentmore » E) and electron concentrations n{sub e}. The frequency dependence of P(ω{sub q}, θ) shows a maximum P{sub m}(ω{sub q}, θ) at about ω{sub m} ≈ 1 THz and is found to increase with the increasing v{sub d} and n{sub e}. The value of ω{sub m} shifts to higher region for larger n{sub e}. It is found that ω{sub m}/n{sub e}{sup 1/3} and P{sub m}(ω{sub q}, θ)/n{sub e}{sup 2/3} are nearly constants. The latter is in contrast with the P{sub m}(ω{sub q}, θ)n{sub e}{sup 1/2 }= constant in conventional bulk semiconductor. Each maximum is followed by a vanishing spectrum at nearly “2k{sub f} cutoff,” where k{sub f} is the Fermi wave vector. Angular dependence of P(ω{sub q}, θ) and the intensity P(θ) of the phonon emission shows a maximum at an emission angle 45° and is found to increase with increasing v{sub d}. P(θ) is found to increase linearly with n{sub e} giving the ratio P(θ)/(n{sub e}v{sub d}) nearly a constant. We suggest that it is possible to have the controlled Cerenkov emission and generation of acoustic phonons with the proper choice of E, θ, and n{sub e}. 3DDS with large n{sub e} and mobility can be a good source of acoustic phonon generation in ∼THz regime.« less

Hydrogen ion secretion by the collecting duct as a determinant of the urine to blood PCO2 gradient in alkaline urine

DOE Office of Scientific and Technical Information (OSTI.GOV)

DuBose, T.D. Jr.

1982-01-01

Several theories have been advanced to explain the elevation in urinary PCO/sub 2/ during bicarbonate loading and include: (a) H+ secretion, (b) countercurrent system for CO/sub 2/, (c) the ampholyte properties of bicarbonate, and (d) mixing of urine of disparate bicarbonate and butter concentrations. In this study microelectrodes were used to measure in situ and equilibrium pH (pHis and pHeq) and PCO/sub 2/ in control and bicarbonate loaded rats before and after infusion of carbonic anhydrase. The disequilibrium pH method (pHdq . pHis - pHeq) was used to demonstrate H+ secretion. Control rats excreting an acid urine (pH . 6.04more » +/- 0.06) failed to display a significant disequilibrium pH at the base (BCD), or tip (TCD) of the papillary collecting duct. Urine pH (7.54 +/- 0.12), and urine to blood (U-B) PCO/sub 2/ increased significantly during NaHCO/sub 3/ loading while PCO/sub 2/ at the BCD and TCD also increased (95 +/- 4 and 122 +/- 4). Furthermore, an acid disequilibrium pH was present at both the BCD and TCD (-0.42 +/- 0.04 and -0.36 +/- 0.03) and was obliterated by carbonic anhydrase. Comparison of the PCO/sub 2/ in the BCD or TCD with the adjacent vasa recta revealed similar values (r . 0.97). It is concluded that H+ secretion by the collecting duct into bicarbonate containing fluid with delayed dehydration of H/sub 2/CO/sub 3/, is the most likely determinant of the U-B PCO/sub 2/ in alkaline urine. Similar values for PCO/sub 2/ in the collecting duct and the adjacent vasa recta suggests trapping of CO/sub 2/ in the medullary countercurrent system. The rise in PCO/sub 2/ occurs both along the collecting duct and after exit from the papilla.« less

Exotic and qq-bar resonances in the pi+pi-pi- system produced in pi-p collisions at 18 GeV/c

DOE Office of Scientific and Technical Information (OSTI.GOV)

S. U. Chung; K. Danyo; R. W. Hackenburg

A partial-wave analysis of the reaction pi{sup -}p-->pi{sup +}pi{sup -}pi{sup -}p at 18 GeV/c has been performed on a data sample of 250 000 events obtained in the Brookhaven experiment E852. The well-known a{sub 1}(1260), a{sub 2}(1320) and pi{sub 2}(1670) resonant states are observed. The existence of the pi(1800), a{sub 1}(1700) and a{sub 4}(2040) states is confirmed. The a{sub 3}(1874) state is also observed. The exotic 1{sup -+} pi{sub 1}(1600) state produced in the natural parity exchange process is found to decay in the rho(770)pi{sup -} channel. A mass-dependent fit results in a resonance mass of 1593{+-}8{sub -47}{sup +29} MeV/c{supmore » 2} and a width of 168{+-}20{sub -12}{sup +150} MeV/c{sup 2}.« less

A 3D chiral metal-organic framework based on left-handed helices containing 3-amino-1 H-1,2,4-triazole ligand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Bing, E-mail: bliu_1203@163.com; Yang, Tian-Yi; Feng, Hui-Jun

2015-10-15

A chiral metal-organic framework, [Cu(atr)(OH)]·0.5H{sub 2}O·0.5en (1) (Hatr=3-amino-1 H-1,2,4-triazole, en=ethylenediamine), was constructed via diffusion reaction of the achiral Hatr ligand and CuSO{sub 4} as starting materials. Compound 1 crystallizes in the chiral space group P3{sub 2}21 and features a porous metal-organic framework with 44.1% solvent-accessible volume fabricated by left-handed helices with a pitch height of l{sub p}=10.442 Å. Six helices gather around in a cycle forming a large honeycomb channel with a 6.58 Å inner diameter. Cu(II) center and atr{sup ‒} ligand regarded as 3-connected nodes, compound 1 can be simplified to a 3-c uninodal (4.12{sup 2}) (qtz-h) topological network.more » A gradual decreasing in the magnetic moment depending on temperature decreasing indicates an antiferromagnetic interaction in 1. The powder XRD confirms the bulk sample is a single crystal pure phase, and the thermogravimetric analysis shows the thermal stability of 1 is up to ca. 240 °C. - Highlights: • The present 3D chiral MOF is built from achiral Hatr ligand. • Six left-handed helices gather into a honeycomb channel in chiral sp P3{sub 2}21. • Compound 1 shows a 3-c uninodal (4.12{sup 2}) or qtz-h topological network. • Compound 1 indicates an antiferromagnetic interaction.« less

Crystallization and Preliminary X-ray Analysis of the Human Long Myosin Light-Chain Kinase 1-Specific Domain IgCAM3

DOE Office of Scientific and Technical Information (OSTI.GOV)

W Vallen Graham; A Magis; K Bailey

2011-12-31

Myosin light-chain kinase-dependent tight junction regulation is a critical event in inflammatory cytokine-induced increases in epithelial paracellular permeability. MLCK is expressed in human intestinal epithelium as two isoforms, long MLCK1 and long MLCK2, and MLCK1 is specifically localized to the tight junction, where it regulates paracellular permeability. The sole difference between these long MLCK splice variants is the presence of an immunoglobulin-like cell-adhesion molecule domain, IgCAM3, in MLCK1. To gain insight into the structure of the IgCAM3 domain, the IgCAM3 domain of MLCK1 has been expressed, purified and crystallized. Preliminary X-ray diffraction data were collected to 2.0 {angstrom} resolution andmore » were consistent with the primitive trigonal space group P2{sub 1}2{sub 1}2{sub 1}.« less

Rate of intramolecular reduction of oxyferryl iron in horse heart myoglobin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fenwick, C.; Marmor, S.; Govindaraju, K.

1994-04-06

Like heme peroxidases and other heme enzymes, myoglobin forms oxyferryl (Fe[sup IV][triple bond]O) on reaction with peroxides. We have recently observed slow intramolecular electron transfer (ET) to the oxyferryl heme of cytochrome c peroxidase (CCP) from a[sub 5]Ru[sup II] (a[sub 5]Ru = pentaammineruthenium) bound at His60 and proposed a large reorganizational energy ([lambda]) for oxyferryl heme. An obvious test of this large postulated [lambda] is to directly compare intramolecular ET rates between oxyferryl and a[sub 5]Ru centers in myoglobin with the corresponding rates in zinc-substituted sperm whale (SWMb) and recombinant human myoglobins (RHMb). Since the oxyferryl heme of horse heartmore » myoglobin (HHMb) is significantly more stable than that of SWMb, the former protein was chosen for this study. A a[sub 5]Ru group was attached to the surface His48 of HHMb, and rates of ET over the 12.7-angstrom distance between the a[sub 5]Ru center and the ferric and oxyferryl hemes were measured by pulse radiolysis at Brookhaven National Laboratory. HHMb (0.5-10 [mu]M) solutions were prepared in N[sub 2]O-saturated sodium phosphate buffer at pH 7.0 (40 mM) containing 12 mM HCOONa to generate CO[sub 2][sup .[minus

Edge ohmic heating and improved confinement on HT-6M Tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, X.

1995-04-01

An improved confinement has been observed on HT-6M tokamak after application of Edge Ohmic Heating (EOH) which makes plasma current rapidly ramp up from an initial steady state (I{sub p}=55 kA) within a small time scale (0.4 ms) to a second steady state (I{sub p}=60 kA) with a ramp rate of 12 MA/sec. The improved confinement is characterized by (a) increased average density n{sub e}; (b) reduced H{sub alpha} radiation; (c) reduced density fluctuations both in the center and at the edge; (d) a steeper n{sub e} and T{sub e} profile at the edge; (e) the changed profiles of plasmamore » parameters n{sub e}(r), q(r) and j(r); (f) transferred the oscillation modes of the soft-X ray signals from Mirnov fluctuation (12 kHz) to sawtooth oscillation (1.7 kHz). The changes of edge fluctuation, radial electric field and bremsstrahlung during EOH were measured and discussed in details. The measured values of {beta}{sub p}+l{sub i}/2 and soft-X ray sawtooth inversion radius implied the anomalous current penetration. 10 refs., 2 figs.« less

Measured pressure broadening and shift rates of the 1. 73. mu. m (5 d (3/2) sub 1 --6 p (5/2) sub 2 ) transition of xenon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hebner, G.A.; Hays, G.N.

1991-07-29

Pressure broadening and line center shift rates as a function of helium, neon, and argon pressure have been measured for the 1.73 {mu}m (5{ital d}(3/2){sub 1}--6{ital p}(5/2){sub 2}) transition in xenon. The pressure broadening rates are 20.3{plus minus}6.4, 12.7{plus minus} 3.5, and 19.7{plus minus}2.9 MHz/Torr for helium, neon, and argon buffers, respectively.

Synthesis and structural characterization of (C sub 5 Me sub 5 )Zr(R) sub 2 (L) sub n sup + complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crowther, D.J.; Jordan, R.F.; Baenziger, N.C.

1990-09-01

The reaction of (C{sub 5}Me{sub 5})Zr(CH{sub 3}){sub 3} with ((C{sub 5}H{sub 4}Me){sub 2}Fe)(BPh{sub 4}) in THF yields ((C{sub 5}Me{sub 5})Zr(CH{sub 3}){sub 2}(THF){sub 2})(BPh{sub 4}) (1) via oxidative cleavage of a Zr-CH{sub 3} bond. X-ray diffraction reveals that the cation of 1 adopts a square-pyramidal/four-legged piano-stool structure with cis CH{sub 3} groups. The orientations of the THF ligands and the Zr-O bond distances suggest that Zr-O {pi}-bonding is important for at least one of the THF ligands. Data for 1: a = 14.551 (2) {angstrom}, b = 15.191 (4) {angstrom}, c = 17.852 (19) {angstrom}, {beta} = 92.26 (3){degree}, V =more » 3,943 (6) {angstrom}{sup 3}, Z = 4 in space group P2{sub 1}/c. Reaction of 1 with excess dmpe in THF solution yields ((C{sub 5}Me{sub 5})Zr(CH{sub 3}){sub 2}(dmpe)(THF))(BPh{sub 4}) (2), which also has been characterized by X-ray diffraction.« less

Phase transition, crystal water and low thermal expansion behavior of Al{sub 2−2x}(ZrMg){sub x}W{sub 3}O{sub 12}·n(H{sub 2}O)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Fang; Liu, Xiansheng; Song, Wenbo

2014-10-15

Al{sub 2−2x}(ZrMg){sub x}W{sub 3}O{sub 12} for 0≤x≤1.0 are synthesized to reduce the phase transition temperature of Al{sub 2}W{sub 3}O{sub 12}. It is found that the incorporation of (ZrMg){sup 6+} into the lattice of Al{sub 2}W{sub 3}O{sub 12} not only reduces its orthorhombic-to-monoclinic phase transition temperature but also elevates its softening temperature, broadening its applicable temperature range considerably. Al{sub 2−2x}(ZrMg){sub x}W{sub 3}O{sub 12} with x<0.5 exhibit low coefficients of thermal expansion (CTEs) and non-hygroscopicity, while those for x≥0.7 are obviously hygroscopic and the CETs decrease with increasing the content of (ZrMg){sup 6+} so that Al{sub 0.2}(ZrMg){sub 0.9}W{sub 3}O{sub 12} and ZrMgW{submore » 3}O{sub 12} exhibit negative thermal expansion. Temperature-dependent Raman spectroscopic study shows the hardening of W–O bonds above 373 K which is attributed to the release of crystal water. The effect of crystal water on the thermal expansion property is discussed based on the hydrogen bond between H in crystal water and electronegative O in Al(ZrMg)–O–W linkages. - Graphical abstract: (a and b) Temperature dependent Raman spectra of Al{sub 2−x}(ZrMg){sub x}W{sub 3}O{sub 12} (x=0.1, 0.2), (c and d) Building block of a unit cell of Al{sub 2−x}(ZrMg){sub x}W{sub 3}O{sub 12}·n(H{sub 2}O) and schematic showing the effect of crystal water on Al(Zr, Mg)–O–W linkages. - Highlights: • (ZrMg){sup 6+} reduces orthorhombic-to-monoclinic phase transition of Al{sub 2}W{sub 3}O{sub 12}. • The incorporation of (ZrMg){sup 6+} elevates the softening temperature of Al{sub 2}W{sub 3}O{sub 12}. • Al{sub 2−2x}(ZrMg){sub x}W{sub 3}O{sub 12} (x<0.5) exhibit low CTEs and non-hygroscopicity. • Al{sub 0.2}(ZrMg){sub 0.9}W{sub 3}O{sub 12}·0.8H{sub 2}O and ZrMgW{sub 3}O{sub 12}·2H{sub 2}O present NTE. • Hydrogen bond between H in H{sub 2}O and O in Al(ZrMg)–O–W affects thermal expansion.« less

Novel lead-iron phosphate glass

DOEpatents

Boatner, Lynn A.; Sales, Brian C.

1989-01-01

The invention described and claimed in the specification relates to the discovery that effective addition of Fe.sub.2 O.sub.3 to a lead phosphate glass results in a glass having enhanced chemical durability and physical stability, and consists essentially of the glass resulting from melting a mixture consisting essentially of, in weight percent, 40-66 percent PbO, 30-55 percent P.sub.2 O.sub.5 and an effective concentration up to 12 percent Fe.sub.2 O.sub.3.

Novel lead-iron phosphate glass

DOEpatents

Boatner, L.A.; Sales, B.C.

1989-07-11

The invention described and claimed in the specification relates to the discovery that effective addition of Fe[sub 2]O[sub 3] to a lead phosphate glass results in a glass having enhanced chemical durability and physical stability, and consists essentially of the glass resulting from melting a mixture consisting essentially of, in weight percent, 40--66 percent PbO, 30--55 percent P[sub 2]O[sub 5] and an effective concentration up to 12 percent Fe[sub 2]O[sub 3].

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vogel, E.A.F.

A series of new tetranuclear molybdenum(II) nitrile cluster derivatives is reported. Improvements in the synthetic routes to these and other derivatives is also reported. The single crystal x-ray structure of Mo/sub 4/Cl/sub 12//sup 4/minus// is modeled. New tetrameric nitrile derivatives with the stoichiometry Mo/sub 4/Cl/sub 8/(RCN)/sub 4/ (R = Pr/sup n/, Pr/sup i/, Bu/sup t/, PhCH/sub 2/) have been isolated by ligand exchange from Mo/sub 4/Cl/sub 8/(EtCN)/sub 4/ and/or direct synthesis from Mo/sub 4/Cl/sub 8/(PBu/sup n/sub 3//)/sub 4/. Mo/sub 4/Cl/sub 8/(Pr/sup n/CN)/sub 4/ was synthesized with higher yields and with simpler reaction conditions than Mo/sub 4/Cl/sub 8/(EtCN)/sub 4/. Improved syntheticmore » routes for R/sub 4/Mo/sub 4/Cl/sub 12/ (R = Et/sub 4/N, Pr/sub 4/N) have been developed. (Et/sub 4/N)/sub 4/Mo/sub 4/Cl/sub 12/ can be directly synthesized from the phosphine tetramer, circumventing the preparation of the reactive species-Mo/sub 4/Cl/sub 8/(EtCN)/sub 4/, which is the most difficult precursor to prepare. A change in reaction solvent, from dichloromethane or dichloroethane to chlorobenzene, in the preparation of (Pr/sub 4/N)/sub 4/Mo/sub 4/Cl/sub 12/ has permitted its isolation under less rigorous conditions and in high yield. A single crystal structure determination has been done on a sample of (Ph/sub 4/P)/sub 4/Mo/sub 4/Cl/sub 12/. Although, the quality of the data is poor, the structure of the Mo/sub 4/Cl/sub 12/ cluster core was refined. Four complex types have been found to fit the data. 22 refs., 12 figs., 7 tabs.« less

On the mass of the local group

DOE Office of Scientific and Technical Information (OSTI.GOV)

González, Roberto E.; Kravtsov, Andrey V.; Gnedin, Nickolay Y., E-mail: regonzar@astro.puc.cl

2014-10-01

We use recent proper motion measurements of the tangential velocity of M31, along with its radial velocity and distance, to derive the likelihood of the sum of halo masses of the Milky Way and M31. This is done using a sample of halo pairs in the Bolshoi cosmological simulation of ΛCDM cosmology selected to match the properties and the environment of the Local Group. The resulting likelihood gives an estimate of the sum of the masses of M {sub MW,} {sub 200c} + M {sub M31,} {sub 200c} = 2.40{sub −1.05}{sup +1.95}×10{sup 12} M{sub ⊙} (90% confidence interval). This estimatemore » is consistent with individual mass estimates for the Milky Way and M31 and is consistent, albeit somewhat on the low side, with the mass estimated using the timing argument. We show that although the timing argument is unbiased on average for all pairs, for pairs constrained to have radial and tangential velocities similar to that of the Local Group the argument overestimates the sum of masses by a factor of 1.6. Using similar technique, we estimate the total dark matter mass enclosed within 1 Mpc from the Local Group barycenter to be M{sub LG}(r<1 Mpc)=4.2{sub −2.0}{sup +3.4}×10{sup 12} M{sub ⊙} (90% confidence interval).« less

Multiple bonds between transition metals and main-group elements. 73. Synthetic routes to rhenium(V) alkyl and rhenium(VII) alkylidyne complexes. X-ray crystal structures of (. eta. sup 5 -C sub 5 Me sub 5 )Re( double bond O)(CH sub 3 )(CH sub 2 C(CH sub 3 ) sub 3 ) and (. eta. sup 5 -C sub 5 Me sub 5 )(Br) sub 3 Re triple bond CC(CH sub 3 ) sub 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herrmann, W.A.; Felixberger, J.K.; Anwander, R.

1990-05-01

Dialkyloxo({eta}{sup 5}pentamethylcyclopentadienyl)rhenium(V) complexes ({eta}{sup 5}-C{sub 5}Me{sub 5})Re({double bond}O)(CH{sub 3})R{prime}(R{prime} = C{sub 2}H{sub 5}, CH{sub 2}Si(CH{sub 3}){sub 3}, CH{sub 2}C(CH{sub 3}){sub 3}), 1c-e, have become accessible through alkylation of ({eta}{sup 5}-C{sub 5}Me{sub 5})Re({double bond}O)(Cl)(CH{sub 3}) (7) with R{prime}MgCl. 1c-e are the first rhenium complexes containing different alkyl ligands. The neopentyl derivative 1e (R{prime} = CH{sub 2}C(CH{sub 3}){sub 3}) crystallizes in the orthorhombic space group Pbca with a = 960.7 (2), b = 2.844.5 (4), c = 1,260.7 (2) pm, and Z = 8. The X-ray crystal structure was refined to R{sub W} = 3.9%. The chiral molecule shows a distorted tetrahedralmore » geometry around the rhenium center. The tribromide 3b has been structurally characterized. Brown crystals of 3b belong to space group P2{sub 1}/c with unit cell dimensions a = 1,311.5 (2), b = 723.0 (1), c = 1,901.6 (2) pm, {beta} = 92.68 (1){degree}, and Z = 4. The structure exhibits a four-legged piano stool geometry with no trans influence of the neopentylidyne ligand to the bromine atom.« less

Universal Behavior of a Cyclic Oxidation Model

NASA Technical Reports Server (NTRS)

Smialek, James L.

2003-01-01

A mathematical model has been generated to represent the iterative, discrete growth and spallation processes associated with cyclic oxidation. Parabolic growth kinetics (k(sub p)) over and a constant spall area (F(sub A)) were assumed, with spalling occurring interfacially at the thickest regions of the scale. Although most models require numerical techniques, the regularity and simplicity of this progression permitted an approximation by algebraic expressions. Normalization could now be performed to reflect all parametric effects, and a universal cyclic oxidation response was generated: W(sub u) = 1/2 {3J(sub u)(sup 1/2)+ J(sub u)(sup 3/2)} where W, is weight change normalized by the maximum and J(sub u) is the cycle number normalized by the number to reach maximum. Similarly, the total amount of metal consumed was represented by a single normalized curve. The factor [(S(sub c)-l)(raised dot)sqrt(F(sub A)k(sub p)DELTAt)] was identified as a general figure of merit, where S(sub c) is the mass ratio of oxide to oxygen and DELTAt is the cycle duration. A cyclic oxidation failure map was constructed, in normalized k(sub p)-F(sub A) space, as defined by the locus of points corresponding to a critical amount of metal consumption in a given time. All three constructions describe behavior for every value of growth rate, spall fraction, and cycle duration by means of single curves, but with two branches corresponding to the times before and after steady state is achieved.

AQUO-OXALATO-SULFATE COMPOUNDS OF URANIUM (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chernyaev, I.I.; Golovnya, V.A.; Shchelokov, R.N.

1960-07-01

The following mixed aquo-acido complex uranyl compounds containing an oxalate and a sulfate group were synthesized for the first time: K/sub 2/STAUO/ sub 2/(C/sub 2/O/sub 4/) (SO/sub 4/ (H/sub 2/O)/sub 2/!. H/sub 2/O, Rb/sub 2/ STAUO/sub 2/(C/sub 2/O/sub 4/)(SO/sub 4/)(H/sub 2/O)/sub 2/!, Cs/sub 2/STAUO/sub 2/(C/sub 2/O/sub 4/)(SO/sub 4/)(H/sub 2/O)/sub 2/)!, and Cs(NH/sub 4/) (UO/sub 2/ (C/sub 2/O/sub 4/) (SO/sub 4/)(H/sub 2/O)/sub 2/!. T he molecular conductivity and pH were determined in dilute solutions, and it was concluded that the decrease in stability of these complexes in aqueous solution is as follows: STAUO/ sub 2/(C/sub 2/O/sub 4/)/sub 2/(H/sub 2/O)/sub 2/!/sup 2-/more » > STAUO/sub 2/(C/su b 2/O/sub 4/)(SO/sub 4)(H/sub 2/O)/sub 2/!/sup 2-/ > STAUO/sub 2/(SO/sub 4/)/sub 2/ (H/sub 2O)/sub 2/!/sup 2-. (TTT)« less

Synthesis and structure of heptaaqua(nitrilotris(methylenephosphonato))(dibarium)sodium monohydrate [Na(H{sub 2}O){sub 3}(μ{sup 6}-NH(CH{sub 2}PO{sub 3}){sub 3})(μ-H{sub 2}O){sub 3}Ba{sub 2}(H{sub 2}O)] · H{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Somov, N. V., E-mail: somov@phys.unn.ru; Chausov, F. F., E-mail: xps@ftiudm.ru; Zakirova, R. M., E-mail: ftt@udsu.ru

Crystals of the monohydrate form of heptaaqua(nitrilotris(methylenephosphonato))(dibarium) sodium [Na(H{sub 2}O{sub )3}(µ{sup 6}-NH(CH{sub 2}PO{sub 3}){sub 3})(µ-H{sub 2}O){sub 3}Ba{sub 2}(H{sub 2}O)] · H{sub 2}O are obtained; space group P2{sub 1}/c, Z = 4; a = 13.9117(10) Å, b = 11.54030(10) Å, and c = 24.1784(17) Å, ß = 148.785(18)°. The Na atom is coordinated octahedrally by one oxygen atom of a phosphonate group and five water molecules, including two bridging molecules. Ba atoms occupy two inequivalent crystallographic positions with coordination number eight and nine. The coordination spheres of both Ba atoms include two water molecules. Each ligand is bound to one Namore » atom and five Ba atoms forming three Ba–O–P–O and five Ba–O–P–C–N–C–P–O chelate cycles. In addition to the coordination bonds, molecules, including the solvate water molecule, are involved in hydrogen bonds in the crystal packing.« less

Purification, crystallization and preliminary X-ray crystallographic analysis of rice Bowman–Birk inhibitor from Oryza sativa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Yi-Hung; Li, Hsin-Tai; Institute of Bioinformatics and Structural Biology, National Tsing-Hua University, Hsinchu 30013,Taiwan

2006-06-01

Rice Bowman–Birk inhibitor was expressed and crystallized. Bowman–Birk inhibitors (BBIs) are cysteine-rich proteins with inhibitory activity against proteases that are widely distributed in monocot and dicot species. The expression of rice BBI from Oryza sativa is up-regulated and induced by pathogens or insects during germination of rice seeds. The rice BBI (RBTI) of molecular weight 15 kDa has been crystallized using the hanging-drop vapour-diffusion method. According to the diffraction of rice BBI crystals at a resolution of 2.07 Å, the unit cell belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 74.37, b = 96.69, cmore » = 100.36 Å. Preliminary analysis indicates four BBI molecules in an asymmetric unit, with a solvent content of 58.29%.« less

Mono- and bis-tolylterpyridine iridium(III) complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hinkle, Lindsay M.; Young, Jr., Victor G.; Mann, Kent R.

The first structure report of trichlorido[4'-(p-tolyl)-2,2':6',2{double_prime}-terpyridine]iridium(III) dimethyl sulfoxide solvate, [IrCl{sub 3}(C{sub 22}H{sub 17}N{sub 3})] {center_dot} C{sub 2}H{sub 6}OS, (I), is presented, along with a higher-symmetry setting of previously reported bis[4'-(p-tolyl)-2,2':6',2{double_prime}-terpyridine]iridium(III) tris(hexafluoridophosphate) acetonitrile disolvate, [Ir(C{sub 22}H{sub 17}N{sub 3})2](PF{sub 6}){sub 3} {center_dot} 2C{sub 2}H{sub 3}N, (II) [Yoshikawa, Yamabe, Kanehisa, Kai, Takashima & Tsukahara (2007). Eur. J. Inorg. Chem. pp. 1911-1919]. For (I), the data were collected with synchrotron radiation and the dimethyl sulfoxide solvent molecule is disordered over three positions, one of which is an inversion center. The previously reported structure of (II) is presented in the more appropriate C2/c space group.more » The iridium complex and one PF{sub 6}{sup -} anion lie on twofold axes in this structure, making half of the molecule unique.« less

The crystal structure of tin sulphate, SnSO[subscript 4], and comparison with isostructural SrSO[subscript 4], PbSO[subscript 4], and BaSO[subscript 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antao, Sytle M.

2012-10-23

The crystal structure of tin (II) sulphate, SnSO{sub 4}, was obtained by Rietveld refinement using synchrotron high-resolution powder X-ray diffraction (HRPXRD) data. The structure was refined in space group Pbnm. The unit-cell parameters for SnSO{sub 4} are a = 7.12322(1), b = 8.81041(1), c = 5.32809(1) {angstrom}, and V = 334.383(1) {angstrom}{sup 3}. The average [12] distance is 2.9391(4) {angstrom}. However, the Sn{sup 2+} cation has a pyramidal [3]-coordination to O atoms and the average [3] = 2.271(1) {angstrom}. If Sn is considered as [12]-coordinated, SnSO{sub 4} has a structure similar to barite, BaSO{sub 4}, and its structuralmore » parameters are intermediate between those of BaSO{sub 4} and PbSO{sub 4}. The tetrahedral SO{sub 4} group has an average [4] = 1.472(1) {angstrom} in SnSO{sub 4}. Comparing SnSO{sub 4} with the isostructural SrSO{sub 4}, PbSO{sub 4}, and BaSO{sub 4}, several well-defined trends are observed. The radii, rM, of the M{sup 2+}(=Sr, Pb, Sn, and Ba) cations and average distances vary linearly with V because of the effective size of the M{sup 2+} cation. Based on the trend for the isostructural sulphates, the average [12] distance is slightly longer than expected because of the lone pair of electrons on the Sn{sup 2+} cation.« less

Precision Measurement of the Mass of the h{sub c}({sup 1}P{sub 1}) State of Charmonium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dobbs, S.; Metreveli, Z.; Seth, K. K.

2008-10-31

A precision measurement of the mass of the h{sub c}({sup 1}P{sub 1}) state of charmonium has been made using a sample of 24.5x10{sup 6} {psi}(2S) events produced in e{sup +}e{sup -} annihilation at the Cornell Electron Storage Ring (CESR). The reaction used was {psi}(2S){yields}{pi}{sup 0}h{sub c}, {pi}{sup 0}{yields}{gamma}{gamma}, h{sub c}{yields}{gamma}{eta}{sub c}, and the reaction products were detected in the CLEO-c detector. Data have been analyzed both for the inclusive reaction and for the exclusive reactions in which {eta}{sub c} decays are reconstructed in 15 hadronic decay channels. Consistent results are obtained in the two analyses. The averaged results of themore » present measurements are M(h{sub c})=3525.28{+-} 0.19(stat.){+-}0.12(syst.) MeV, and B({psi}(2S){yields}{pi}{sup 0}h{sub c})xB(h{sub c}{yields}{gamma}{eta}{sub c})=(4.19{+-}0.32{+-}0.45)x10{sup -4}. Using the {sup 3}P{sub J} centroid mass, {delta}M{sub hf}(1P){identical_to}-M(h{sub c})=+0.02{+-}0.19{+-}0.13 MeV.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mufti, Nandang, E-mail: nandangmufti@gmail.com; Atma, T., E-mail: nandangmufti@gmail.com; Fuad, A., E-mail: nandangmufti@gmail.com

The aim of this research is to synthesize nanoparticles of black pigment of Magnetite (Fe{sub 3}O{sub 4}), red pigment of hematite (α-Fe{sub 2}O{sub 3}), and yellow pigment of ghoetite (α-FeOOH) from the iron sand. The black pigment of Fe{sub 3}O{sub 4} and the yellow pigment α-FeOOH nanoparticles were synthesized by coprecipitation method with variation of pH. Whereas, the red pigment Fe{sub 2}O{sub 3} was synthesized by sintering Fe{sub 3}O{sub 4} nanoparticles at temperature between 400 °C and 700 7°C for 1 hour. All the pigments has been characterized using X-ray diffraction and SEM. The XRD results shown that the particlemore » size of the black pigmen Fe{sub 3}O{sub 4}, red pigment Fe{sub 3}O{sub 4} and yellow pigment α-FeOOH are around 12, 32, and 30 nm respectively. The particle size of Fe{sub 2}O{sub 3} nanoparticles increase by increasing sintering temperature from 32 nm at 400 °C to 39 nm at 700 °C. For yellow pigment of α-FeOOH, the particle size increase by increasing pH from 30,54 nm at pH 4 to 48,60 nm at pH 7. The SEM results shown that the morphologies of black, yellow and red pigments are aglomarated.« less

VO{sub 2} (A): Reinvestigation of crystal structure, phase transition and crystal growth mechanisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao Popuri, Srinivasa; University of Bordeaux, ICMCB, UPR 9048, F-33608 Pessac; National Institute for Research and Development in Electrochemistry and Condensed Matter, Timisoara, Plautius Andronescu Str. No. 1, 300224 Timisoara

2014-05-01

Well crystallized VO{sub 2} (A) microrods were grown via a single step hydrothermal reaction in the presence of V{sub 2}O{sub 5} and oxalic acid. With the advantage of high crystalline samples, we propose P4/ncc as an appropriate space group at room temperature. From morphological studies, we found that the oriented attachment and layer by layer growth mechanisms are responsible for the formation of VO{sub 2} (A) micro rods. The structural and electronic transitions in VO{sub 2} (A) are strongly first order in nature, and a marked difference between the structural transition temperatures and electronic transitions temperature was evidenced. The reversiblemore » intra- (LTP-A to HTP-A) and irreversible inter- (HTP-A to VO{sub 2} (M1)) structural phase transformations were studied by in-situ powder X-ray diffraction. Attempts to increase the size of the VO{sub 2} (A) microrods are presented and the possible formation steps for the flower-like morphologies of VO{sub 2} (M1) are described. - Graphical abstract: Using a single step and template free hydrothermal synthesis, well crystallized VO{sub 2} (A) microrods were prepared and the P4/ncc space group was assigned to the room temperature crystal structure. Reversible and irreversible phase transitions among different VO{sub 2} polymorphs were identified and their progressive nature was highlighted. Attempts to increase the microrods size, involving layer by layer formation mechanisms, are presented. - Highlights: • Highly crystallized VO{sub 2} (A) microrods were grown via a single step hydrothermal process. • The P4/ncc space group was determined for VO{sub 2} (A) at room temperature. • The electronic structure and progressive nature of the structural phase transition were investigated. • A weak coupling between structural and electronic phase transitions was identified. • Different crystallite morphologies were discussed in relation with growth mechanisms.« less

Value of Diffusion-Weighted Magnetic Resonance Imaging for Prediction and Early Assessment of Response to Neoadjuvant Radiochemotherapy in Rectal Cancer: Preliminary Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lambrecht, Maarten, E-mail: maarten.lambrecht@uzleuven.be; Vandecaveye, Vincent; De Keyzer, Frederik

2012-02-01

Purpose: To evaluate diffusion-weighted magnetic resonance imaging (DWI) for response prediction before and response assessment during and early after preoperative radiochemotherapy (RCT) for locally advanced rectal cancer (LARC). Methods and Materials: Twenty patients receiving RCT for LARC underwent MRI including DWI before RCT, after 10-15 fractions and 1 to 2 weeks before surgery. Tumor volume and apparent diffusion coefficient (ADC; b-values: 0-1000 s/mm{sup 2}) were determined at all time points. Pretreatment tumor ADC and volume, tumor ADC change ( Increment ADC), and volume change ( Increment V) between pretreatment and follow-up examinations were compared with histopathologic findings after total mesorectalmore » excision (pathologic complete response [pCR] vs. no pCR, ypT0-2 vs. ypT3-4, T-downstaging or not). The discriminatory capability of pretreatment tumor ADC and volume, Increment ADC, and Increment V for the detection of pCR was compared with receiver operating characteristics analysis. Results: Pretreatment ADC was significantly lower in patients with pCR compared with patients without (in mm{sup 2}/s: 0.94 {+-} 0.12 Multiplication-Sign 10{sup -3} vs. 1.19 {+-} 0.22 Multiplication-Sign 10{sup -3}, p = 0.003), yielding a sensitivity of 100% and specificity of 86% for detection of pCR. The volume reduction during and after RCT was significantly higher in patients with pCR compared with patients without (in %: {Delta}V{sub during}: -62 {+-} 16 vs. -33 {+-} 16, respectively, p = 0.015; and {Delta}V{sub post}: -86 {+-} 12 vs. -60 {+-} 21, p = 0.012), yielding a sensitivity of 83% and specificity of 71% for the {Delta}V{sub during} and, respectively, 83% and 86% for the {Delta}V{sub post}. The Increment ADC during ({Delta}ADC{sub during}) and after RCT ({Delta}ADC{sub post}) showed a significantly higher value in patients with pCR compared with patients without (in %: {Delta}ADC{sub during}: 72 {+-} 14 vs. 16 {+-} 12, p = 0.0006; and {Delta}ADC{sub post}: 88 {+-} 35 vs. 26 {+-} 19, p = 0.0011), yielding a sensitivity and specificity of 100% for the {Delta}ADC{sub during} and, respectively, 100% and 93% for the {Delta}ADC{sub post}. Conclusions: These initial findings indicate that DWI, using pretreatment ADC, {Delta}ADC{sub during}, and {Delta}ADC{sub post} may be useful for prediction and early assessment of pathologic response to preoperative RCT of LARC, with higher accuracy than volumetric measurements.« less

Luminescence properties and electronic structure of Ce{sup 3+}-doped gadolinium aluminum garnet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dotsenko, V.P., E-mail: ssclab@ukr.net; Berezovskaya, I.V.; Voloshinovskii, A.S.

2015-04-15

Highlights: • The luminescence properties of Ce{sup 3+} ions in (Y, Gd){sub 3}Al{sub 5}O{sub 12} are analyzed. • The Gd{sup 3+} → Y{sup 3+} substitution leads to increasing of Ce{sup 3+} noncubic crystal field splitting parameter. • The excitation spectra for the Ce{sup 3+} emission in GdAG contain bands at 6.67, 7.75, and 9.76 eV. • These features are due to the Ce{sup 3+}-bound exciton formation and O 2p → Al 3s, 3p transitions. • Contributions from Al atoms to the conduction-band density of states are quite essential. - Abstract: Yttrium-gadolinium aluminum garnets (YGdAG) doped with Ce{sup 3+} ions havemore » been prepared by co-precipitation method. The luminescent properties of Ce{sup 3+} ions in Gd{sub 3(1−x)}Ce{sub 3x}Al{sub 5}O{sub 12} (x = 0.01) have been studied upon excitation in the 2–20 eV region. The substitution of Gd{sup 3+} for Y{sup 3+} in the garnet structure results in broadening the emission band and shifting its maximum towards the longer wavelengths. It was found that in addition to the 4f → 5d excitation bands of Ce{sup 3+} ions, the excitation spectra for the Ce{sup 3+} emission contain bands at 6.67, 7.75, and 9.76 eV. These bands are attributed to the Ce{sup 3+}-bound exciton formation and O 2p → Al 3s, 3p transitions, respectively. Although gadolinium states dominate near the bottom of the conduction band of Gd{sub 3}Al{sub 5}O{sub 12}, contributions from Al{sub tetr} and Al{sub oct} atoms to the conduction-band density of states are evaluated as quite essential.« less

Study of the structure of PyHReO{sub 4} under high pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kichanov, S. E., E-mail: ekich@nf.jinr.ru; Kozlenko, D. P.; Wasicki, J. W.

2007-05-15

The structure of deuterated pyridinium perrhenate (d{sub 5}PyH)ReO{sub 4} (C{sub 5}D{sub 5}NHReO{sub 4}) is studied by X-ray diffraction at room temperature and pressures up to 3.5 GPa and by neutron diffraction in the temperature range 10-293 K and at pressures up to 2.0 GPa. Under normal conditions, this compound belongs to the orthorhombic space group Cmc2{sub 1} (ferroelectric phase II). At room temperature and pressures above P > 0.7 GPa, a transition to an orthorhombic phase (paraelectric phase II) is observed. This paraelectric phase is described by the space group Cmcm. At a pressure as high as P = 2.0more » GPa, phase I remains stable at temperatures down to 10 K. This fact indicates that the high pressure suppresses the ferroelectric state in deuterated pyridinium perrhenate (d{sub 5}PyH)ReO{sub 4}.« less

New members of the A{sub 2}M′M{sub 2}{sup ″} structure family (A=Ca, Sr, Yb, La; M′=In,Sn,Pb; M″=Si,Ge)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jehle, Michael; Dürr, Ines; Fink, Saskia

The new mixed tetrelides Sr{sub 2}PbGe{sub 2} and Yb{sub 2}SnGe{sub 2}, several mixed Ca/Sr (A{sup II}) germanides A{sub 2}{sup II}(Sn,Pb)Ge{sub 2} and two polymorphs of La{sub 2}InSi{sub 2} represent new members of the general structure family of ternary alkaline-earth/lanthanoid main group silicides/germanides A{sub 2}M′M{sub 2}{sup ″}(M′=In,Sn,Pb;M″=Si,Ge). All compounds were synthesized from melts of the elements and their crystal structures have been determined by means of single crystal X-ray diffraction. Sr{sub 2}PbGe{sub 2} (Cmmm, a=402.36(11), b=1542.3(4), c=463.27(10) pm) crystallizes with the Mn{sub 2}AlB{sub 2}-type structure. In exhibiting infinite planar Ge zig-zag chains, it represents one border of the compound series. Themore » other borderline case, where only [Ge{sub 2}] dumbbells are left as Ge building units, is represented by the Ca/Yb tin germanides Ca{sub 2}SnGe{sub 2} and Yb{sub 2}SnGe{sub 2} (Mo{sub 2}FeB{sub 2}-type; P4/mbm, a=748.58(13)/740.27(7), c=445.59(8)/435.26(5) pm). In between these two border structures compounds with variable Si/Ge chain lengths could be obtained by varying the averaged size of the A{sup II} cations: Ca{sub 0.45}Sr{sub 1.55}PbGe{sub 2} (new structure type; Pbam, a=791.64(5), b=2311.2(2), c=458.53(3) pm) contains planar six-membered chain segments [Ge{sub 6}]. Tetrameric pieces [Ge{sub 4}] are the conspicuous structure elements in Ca{sub 1.16}Sr{sub 0.84}SnGe{sub 2} and La{sub 2}InSi{sub 2} (La{sub 2}InNi{sub 2}-type; Pbam, a=781.01(2)/762.01(13), b=1477.95(3)/1494.38(6), c=457.004(9)/442.1(3) pm). The tetragonal form of ’La{sub 2}InSi{sub 2}{sup ′} (exact composition: La{sub 2}In{sub 1.07}Si{sub 1.93}, P4/mbm, a=1309.11(12), c=443.32(4) pm) also crystallizes in a new structure type, containing only [Si{sub 3}] trimers as cutouts of the planar chains. In all structures the Si/Ge zig-zag chains/chain segments are connected by In/Sn/Pb atoms to form planar M layers, which are separated by pure A layers. Band structure calculations within the FP-LAPW DFT approach together with the Zintl formalism, extended by the presence of hypervalent bonding of the heavier M′ elements, give insight into the chemical bonding of this series of p-block metallides. An analysis of the band structure for the border phases Sr{sub 2}PbGe{sub 2} and Ca{sub 2}SnGe{sub 2} shows the considerable π bonding contributions within the Ge building units, which also become apparent from the short Ge–Ge bond lengths. - Graphical abstract: Example of one of the mixed metallides A{sub 2}(In/Sn/Pb)(Si/Ge){sub 2} with planar Si/Ge zig-zag chain segments of variable lengths. - Highlights: • Mixed metallides A{sub 2}(In/Sn/Pb)(Si/Ge){sub 2} were prepared for A=Ca, Sr, Yb, La. • The structures exhibit planar Si/Ge zig-zag chain segments of variable lengths. • In, Sn and Pb atoms are connecting the Si/Ge anions to planar nets. • Atomic size effects are investigated by the synthesis of mixed Ca/Sr germanides. • Bandstructure calculations indicate Si/Ge–Si/Ge π bonding contributions.« less

Bismuth zinc vanadate, BiZn{sub 2}VO{sub 6}: New crystal structure type and electronic structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eliziario Nunes, Sayonara; Department of Materials Engineering, Federal University of São Carlos, 13565-905 São Carlos, SP; Wang, Chun-Hai

2015-02-15

We report a combined experimental and computational study of the crystal structure and electronic properties of bismuth zinc vanadate, BiZn{sub 2}VO{sub 6}, known for its visible light photocatalytic activity. The crystal structure has been solved from laboratory powder X-ray diffraction data using the repeated minimisations from random starting values method. BiZn{sub 2}VO{sub 6} adopts a new structure type, based on the following building blocks: corner- and edge-sharing ZnO{sub 4} tetrahedra, ZnO{sub 6} octahedra and VO{sub 4} tetrahedra, and Bi{sub 2}O{sub 12} dimers. It is the only known member of the BiM{sub 2}AO{sub 6} (M=Pb, Ca, Cd, Mn, Zn, Mg, Cu;more » A=V, P, As) family which does not appear to be structurally closely related to others. The electronic structure of BiZn{sub 2}VO{sub 6}, calculated by DFT methods, shows that it is an indirect gap semiconductor with a calculated band gap of 1.6 eV, which compares favourably to the experimentally measured value of 2.4 eV. - Graphical abstract: The crystal structure of BiZn{sub 2}VO{sub 6}, a new structure type in the BiM{sub 2}AO{sub 6} (M=Mg, Ca, Cd, Cu, Pb, Mn, Zn; A=V, P, As) family. - Highlights: • Structure solution from PXRD data by repeated minimisations from random starting values. • New structure type in the BiM{sub 2}AO{sub 6} (M=Pb, Ca, Cd, Mn, Zn, Mg, Cu; A=V, P, As) family. • Electronic structure calculation.« less

Conditions and mechanisms for the formation of nano-sized Delafossite (CuFeO{sub 2}) at temperatures ≤90 °C in aqueous solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

John, Melanie, E-mail: melanie.john@min.uni-muenchen.de; Heuss-Aßbichler, Soraya; Ullrich, Aladin

In this study, we present the mechanism of CuFeO{sub 2} formation in aqueous solution at low temperatures ≤90 °C, using sulfate salts as reactants. Furthermore, we demonstrate the influence of experimental conditions (alkalization, reaction and ageing temperature and time) on the synthesized nanoparticles. In all cases, GR–SO{sub 4}, a Fe(II–III) layered double hydroxysulphate (Fe{sup 2+}{sub 4}Fe{sup 3+}{sub 2}(OH){sub 12}·SO{sub 4}) and Cu{sub 2}O precipitate first. During further OH{sup −} supply GR–SO{sub 4} oxidizes and forms Fe{sub 10}O{sub 14}(OH){sub 2}, Cu{sub 2}O and CuFeO{sub 2} crystals. Due to the high pH further CuFeO{sub 2} crystals grow at the cost of themore » unstable intermediate products. The reaction rate increases with increasing ageing temperature, reaction pH and, in particular, NaOH concentrations in the solution. As a result, highly crystalline CuFeO{sub 2} (3R and 2H polytypes) nanoparticles showing hexagonal morphology can be synthesized at 70 °C within 10 h or at 50 °C within 1 week. The formation of 2H polytype is favored by additional OH{sup −} supply during the pH-stat time and rather low temperatures. - Highlights: • We solve the formation mechanism of pure CuFeO{sub 2} using sulfates as reactants. • CuFeO{sub 2} nanoparticles crystallize on cost of green rust, Fe{sub 10}O{sub 14}(OH){sub 2} and Cu{sub 2}O. • The reaction rate increases with increasing temperature and OH- concentration. • CuFeO{sub 2} nanoparticles form at 50 °C within one week and at 70 °C within 10 h. • 2H-polytype of CuFeO{sub 2} is favored by additional NaOH supply during pH-stat-time.« less

Efficient electrocatalytic conversion of CO.sub.2 to CO using ligand-protected Au.sub.25 clusters

DOEpatents

Kauffman, Douglas; Matranga, Christopher; Qian, Huifeng; Jin, Rongchao; Alfonso, Dominic R.

2015-09-22

An apparatus and method for CO.sub.2 reduction using an Au.sub.25 electrode. The Au.sub.25 electrode is comprised of ligand-protected Au.sub.25 having a structure comprising an icosahedral core of 13 atoms surrounded by a shell of six semi-ring structures bonded to the core of 13 atoms, where each semi-ring structure is typically --SR--Au--SR--Au--SR or --SeR--Au--SeR--Au--SeR. The 12 semi-ring gold atoms within the six semi-ring structures are stellated on 12 of the 20 faces of the icosahedron of the Au.sub.13 core, and organic ligand --SR or --SeR groups are bonded to the Au.sub.13 core with sulfur or selenium atoms. The Au.sub.25 electrode and a counter-electrode are in contact with an electrolyte comprising CO.sub.2 and H+, and a potential of at least -0.1 volts is applied from the Au.sub.25 electrode to the counter-electrode.

Theoretical Studies of N2-broadened Half-widths of H2O Lines Involving High j States

NASA Technical Reports Server (NTRS)

Ma, Q.; Tipping, R. H.; Lavrentieva, N. N.

2012-01-01

Based on the properties of the energy levels and wave functions of H2O states, one can categorize H2O lines into individually defined groups such that within the same group, the energy levels and the wave functions associated with two paired lines have an identity property while those associated with different pairs have a similarity property. Meanwhile, by thoroughly analyzing processes used to calculate N2-broadened half-widths, it was found that the 'Fourier series' of W(sup a)(sub L(sub 1))(sub K(sub 1))(sub K(sub 1)) (t; j(sub f) T(sub f) and W(sup a)(sub L(sub 1))(sub K(sub 1))(sub K(sub 1)) (t; j(sub i) T(sub i), and a factor P(sub 222) (j(sub f) T(sub f) j(sub i) T(sub i)) are the key items in the Robert-Bonamy formalism to distinguish contributions to ReS2(r(sub c)) among different transitions of j(sub f) T(sub f) - j(sub i). However, these items are completely determined by the energy levels and the wave functions associated with their initial and final states and they must bear the latter's features as well. Thus, it becomes obvious that for two paired lines in the same group, their calculated half-widths must be almost identical and the values associated with different pairs must vary smoothly as their ji values vary. Thus, the pair identity and the smooth variation rules are established within individual groups of lines. One can use these rules to screen half-width data listed in HITRAN and to improve the data accuracies.

Impact of Tumor Factors on Survival in Patients with Hepatocellular Carcinoma Classified Based on Kinki Criteria Stage B2.

PubMed

Arizumi, Tadaaki; Minami, Tomohiro; Chishina, Hirokazu; Kono, Masashi; Takita, Masahiro; Yada, Norihisa; Hagiwara, Satoru; Minami, Yasunori; Ida, Hiroshi; Ueshima, Kazuomi; Kamata, Ken; Minaga, Kosuke; Komeda, Yoriaki; Takenaka, Mamoru; Sakurai, Toshiharu; Watanabe, Tomohiro; Nishida, Naoshi; Kudo, Masatoshi

2017-01-01

Tumors classified based on the Barcelona Clinic Liver Cancer (BCLC) stage B hepatocellular carcinoma (HCC) are heterogeneous in nature. Previously, the Kinki criterion was proposed for a more precise subclassification of tumors in BCLC-stage B. However, tumors in sub-stage B2 include various size and number of HCCs even with the Kinki criteria, which could lead to heterogeneity for overall survival (OS). In this study, we assessed how the size and number of tumors affect the OS and time to progression (TTP) in patients with Kinki criteria stage B2 tumors and treated with transarterial chemoembolization (TACE). Of 906 HCC patients treated with TACE at Kindai University Hospital, 236 patients with HCC considered as Kinki criteria stage B2 were examined. They were classified into the following 4 groups according to the maximum tumor diameter and number of tumors: B2a group, tumor size ≤6 cm and total number of tumors ≤6; B2b group, size ≤6 cm and number >6; B2c group, size >6 cm and number ≤6; and B2d group, size >6 cm and number >6. The OS and TTP of patients in each group were compared. There were 131 patients (55.5%) in the B2a group, 58 (24.6%) in the B2b group, 41 (17.4%) in the B2c group, and 6 (0.03%) in the B2d group. Comparison of the survivals revealed that the median OS was 2.8 years (95% CI 2.0-3.5) in the B2a group, 2.8 years (95% CI 2.0-3.3) in the B2b group, 1.9 years (95% CI 0.8-4.0) in the B2c group, and 2.3 years (95% CI 1.2-ND [no data]) in the B2d group, respectively (p = 0.896). The median TTP in B2a, B2b, B2c, and B2d sub-substage HCC were13.2, 12.1, 13.8, and 11.5 months, respectively (p = 0.047). The median TTP in B2a + B2c sub-substage patients was longer than that in B2b + B2d sub-substage HCC patients (14.0 months and 10.4 months; p = 0.002). No significant differences were observed in the OS among HCC patients subclassified based on the maximum tumor diameter and tumor number in Kinki criteria stage B2. Consequently, Kinki criteria stage B2 HCC is a homogeneous subgroup in terms of OS prediction. However, shorter TTP in B2b+B2c sub-substage HCC patients than that in B2a + B2c sub-substage HCC patients suggests that different treatment strategy, such as systemic therapy with targeted agents instead of TACE, may be suitable to preserve the liver function. © 2017 S. Karger AG, Basel.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suen, Nian-Tzu; Broda, Matthew; Bobev, Svilen, E-mail: bobev@udel.edu

Reported are the synthesis and the structural characterization of an extended family of rare-earth metal–germanides with a general formula RE{sub 5–x}Ca{sub x}Ge{sub 3} (RE=Y, Ce–Nd, Sm, Gd–Tm and Lu; x<2). All twelve phases are isotypic, crystallizing with the Mn{sub 5}Si{sub 3} structure type (Pearson index hP16, hexagonal space group P6{sub 3}/mcm); they are the Ca-substituted variants of the corresponding RE{sub 5}Ge{sub 3} binaries. Across the series, despite some small variations in the Ca-uptake, the unit cell volumes decrease monotonically, following the lanthanide contraction. Temperature dependent DC magnetization measurements reveal paramagnetic behavior in the high temperature range, and the obtained effectivemore » moments are consistent with free-ion RE{sup 3+} ground state, as expected from prior studies of the binary RE{sub 5}Ge{sub 3} phases. The onset of magnetic ordering is observed in the low temperature range, and complex magnetic interactions (ferromagnetic/ferrimagnetic) can be inferred, different from the binary phases RE{sub 5}Ge{sub 3}, which are known as antiferromagnetic. In order to understand the role of Ca in the bonding, the electronic structures of the La{sub 5}Ge{sub 3} and the hypothetical compounds La{sub 2}Ca{sub 3}Ge{sub 3} and La{sub 3}Ca{sub 2}Ge{sub 3} with ordered metal atoms are compared and discussed. - Graphical abstract: The family of rare-earth metal–calcium–germanides with the general formula RE{sub 5–x}Ca{sub x}Ge{sub 3} (RE=Y, Ce–Nd, Sm, Gd–Tm and Lu) crystallize in the hexagonal space group P6{sub 3}/mcm (No. 193, Pearson symbol hP16) with a structure that is a variant of the Mn{sub 5}Si{sub 3} structure type. - Highlights: • The newly synthesized RE{sub 5–x}Ca{sub x}Ge{sub 3} (RE=Y, Ce–Nd, Sm, Gd–Tm and Lu) constitute an extended family. • The structure is a substitution variant of the hexagonal Mn{sub 5}Si{sub 3} structure type. • Ca-uptake is the highest in the early members, and decreases for the late rare-earth metal analogs. • Experimental and theoretical work suggest limiting solubility range RE{sub ≈3}Ca{sub ≈2}Ge{sub 3}.« less

Coherent states and parasupersymmetric quantum mechanics

NASA Technical Reports Server (NTRS)

Debergh, Nathalie

1992-01-01

It is well known that Parafermi and Parabose statistics are natural extensions of the usual Fermi and Bose ones, enhancing trilinear (anti)commutation relations instead of bilinear ones. Due to this generalization, positive parameters appear: the so-called orders of paraquantization p (= 1, 2, 3, ...) and h sub 0 (= 1/2, 1, 3/2, ...), respectively, the first value leading in each case to the usual statistics. The superpostion of the parabosonic and parafermionic operators gives rise to parasupermultiplets for which mixed trilinear relations have already been studied leading to two (nonequivalent) sets: the relative Parabose and the relative Parafermi ones. For the specific values p = 1 = 2h sub 0, these sets reduce to the well known supersymmetry. Coherent states associated with this last model have been recently put in evidence through the annihilation operator point of view and the group theoretical approach or displacement operator context. We propose to realize the corresponding studies within the new context p = 2 = 2h sub 0, being then directly extended to any order of paraquantization.

Synthesis and structural characterization of the Zintl phases Na{sub 3}Ca{sub 3}TrPn{sub 4}, Na{sub 3}Sr{sub 3}TrPn{sub 4}, and Na{sub 3}Eu{sub 3}TrPn{sub 4} (Tr=Al, Ga, In; Pn=P, As, Sb)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yi; Suen, Nian-Tzu; College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002

15 new quaternary Zintl phases have been synthesized by solid-state reactions from the respective elements, and their structures have been determined by single-crystal X-ray diffraction. Na{sub 3}E{sub 3}TrPn{sub 4} (E=Ca, Sr, Eu; Tr=Al, Ga, In; Pn=P, As, Sb) crystallize in the hexagonal crystal system with the non-centrosymmetric space group P6{sub 3}mc (No. 186). The structure represents a variant of the K{sub 6}HgS{sub 4} structure type (Pearson index hP22) and features [TrPn{sub 4}]{sup 9–} tetrahedral units, surrounded by Na{sup +} and Ca{sup 2+}, Sr{sup 2+}, Eu{sup 2+} cations. The nominal formula rationalization [Na{sup +}]{sub 3}[E{sup 2+}]{sub 3}[TrPn{sub 4}]{sup 9–} follows themore » octet rule, suggesting closed-shell configurations for all atoms and intrinsic semiconducting behavior. However, structure refinements for several members hint at disorder and mixing of cations that potentially counteract the optimal valence electron count. - Graphical abstract: The hexagonal, non-centrosymmetric structure of Na{sub 3}E{sub 3}TrPn{sub 4} (E=Ca, Sr, Eu; Tr=Al, Ga, In; Pn=P, As, Sb) features [TrPn{sub 4}]{sup 9–} tetrahedral units, surrounded by Na{sup +} and Ca{sup 2+}, Sr{sup 2+}, Eu{sup 2+} cations. - Highlights: • 15 quaternary phosphides, arsenides, and antimonides are synthesized and structurally characterized. • The structure is a variant of the hexagonal K{sub 6}HgS{sub 4}-type, with distinctive pattern for the cations. • Occupational and/or positional disorder of yet unknown origin exists for some members of the series.« less

Alkyl group effects on CO insertion into coordinatively unsaturated early-transition-metal alkyls. Preparations and the first structural characterizations of tantalum enolate-O and tantalum. eta. sup 2 -acyl complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meyer, T.Y.; Garner, L.R.; Baenziger, N.C.

1990-10-03

Low-pressure carbonylation of the mono(peralkylcyclopentadienyl)tantalum(V) alkyls ({eta}-C{sub 5}Me{sub 4}R)TaR{prime}Cl{sub 3} (R = Me, Et; R{prime} = CH{sub 2}C{sub 6}H{sub 4}-p-Me, CH{sub 2}CMe{sub 3}) yields either the O-bound enolate or the {eta}{sup 2}-acyl as shown by ir/NMR spectroscopy and x-ray diffractometry. The p-tolyl enolate ({eta}-C{sub 5}Me{sub 5})Ta(OCH{double bond}CHC{sub 6}H{sub 4}-p-Me)Cl{sub 3}, derived directly from carbonylation of the tantalum 4-methylbenzyl precursor, is shown to possess a cis configuration in solution and in the solid state. Key structural features from a single-crystal x-ray diffraction study of the tetrahydrofuran-ligated enolate complex are reported. The mechanism of formation of the enolate from carbonylation of themore » 4-methylbenzyl complex is discussed. The previously reported acyl ({eta}-C{sub 5}Me{sub 4}R)Ta(C(O)CH{sub 2}CMe{sub 3})Cl{sub 3} has been reexamined and found to possess a symmetric, strongly distorted {eta}{sup 2}-acyl coordination by solution {sup 1}H NMR spectroscopy and solid-state x-ray diffractometry. The molecular structures of ({eta}-C{sub 5}Me{sub 5})Ta(OCH{double bond}CHC{sub 6}H{sub 4}-p-Me)Cl{sub 3} and ({eta}-C{sub 5}Me{sub 5})Ta(C(O)CH{sub 2}CMe{sub 3})Cl{sub 3}, which are reported here, are the first structural determinations of a tantalum enolate and of a tantalum {eta}{sup 2}-acyl. 41 refs., 2 figs., 8 tabs.« less

The chemistry of (ring)Ru sup 2+ (ring = tetramethylthiophene, p-cymene)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ganja, E.A.; Rauchfuss, T.B.; Stern, C.L.

1991-01-01

Described are the compounds ((ring)Ru(OTf){sub 2}){sub x}, where ring = 2,3,4,5-tetramethylthiophene (TMT, 1), and p-cymene (2). These electrophilic reagents serve as precursors to ((ring)RuL{sub 3}){sup 2+}, where L{sub 3} = (H{sub 2}O){sub 3}, (NH{sub 3}){sub 3}, and (PH{sub 3}){sub 3}. Solutions of 1 and 2 react with carbon monoxide to give (ring)Ru(CO)(OTf){sub 2}. The addition of thiophenes to CH{sub 2}Cl{sub 2} solutions of 1 or 2 leads to the precipitation of the sandwich compounds ((ring)(SC{sub 4}R{sub 4})Ru)(OTf){sub 2}, where SC{sub 4}R{sub 4} = thiophene, 2,5-dimethylthiophene, and TMT. ((TMT)Ru(H{sub 2}O){sub 3})(OTf){sub 2} was characterized by single-crystal X-ray crystallography, which established amore » piano-stool geometry with a planar TMT ligand. ((TMT)Ru(D{sub 2}O){sub 3})(OTf){sub 2} decomposes in D{sub 2}O solution at 150C to give ((TMT){sub 2}Ru){sup 2+}, which undergoes selective deuteration at the 2,5-methyl groups. D{sub 2}O solutions of ((TMT){sub 2}Ru){sup 2+} undergo photochemical loss of one TMT ligand in water to give ((TMT)Ru(H{sub 2}O){sub 3}){sup 2+}. A procedure is described for the reversible loading of 1 onto {gamma}-alumina, which in turn was characterized by {sup 13}C CP-MAS NMR spectroscopy.« less

cis-trans Germanium chains in the intermetallic compounds ALi{sub 1-x}In{sub x}Ge{sub 2} and A{sub 2}(Li{sub 1-x}In{sub x}){sub 2}Ge{sub 3} (A=Sr, Ba, Eu)-experimental and theoretical studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

You, Tae-Soo; Bobev, Svilen, E-mail: bobev@udel.ed

Two types of strontium-, barium- and europium-containing germanides have been synthesized using high temperature reactions and characterized by single-crystal X-ray diffraction. All reported compounds also contain mixed-occupied Li and In atoms, resulting in quaternary phases with narrow homogeneity ranges. The first type comprises EuLi{sub 0.91(1)}In{sub 0.09}Ge{sub 2}, SrLi{sub 0.95(1)}In{sub 0.05}Ge{sub 2} and BaLi{sub 0.99(1)}In{sub 0.01}Ge{sub 2}, which crystallize in the orthorhombic space group Pnma (BaLi{sub 0.9}Mg{sub 0.1}Si{sub 2} structure type, Pearson code oP16). The lattice parameters are a=7.129(4)-7.405(4) A; b=4.426(3)-4.638(2) A; and c=11.462(7)-11.872(6) A. The second type includes Eu{sub 2}Li{sub 1.36(1)}In{sub 0.64}Ge{sub 3} and Sr{sub 2}Li{sub 1.45(1)}In{sub 0.55}Ge{sub 3}, whichmore » adopt the orthorhombic space group Cmcm (Ce{sub 2}Li{sub 2}Ge{sub 3} structure type, Pearson code oC28) with lattice parameters a=4.534(2)-4.618(2) A; b=19.347(8)-19.685(9) A; and c=7.164(3)-7.260(3) A. The polyanionic sub-structures in both cases feature one-dimensional Ge chains with alternating Ge-Ge bonds in cis- and trans-conformation. Theoretical studies using the tight-binding linear muffin-tin orbital (LMTO) method provide the rationale for optimizing the overall bonding by diminishing the {pi}-p delocalization along the Ge chains, accounting for the experimentally confirmed substitution of Li forIn. -- Graphical abstract: Presented are the single-crystal structures of two types of closely related intermetallics, as well as their band structures, calculated using tight-binding linear muffin-tin orbital (TB-LMTO-ASA) method. Display Omitted« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Volkow, N.D.; Wang, G.; Volkow, N.D.

Attention-deficit/hyperactivity disorder (ADHD) - characterized by symptoms of inattention and hyperactivity-impulsivity - is the most prevalent childhood psychiatric disorder that frequently persists into adulthood, and there is increasing evidence of reward-motivation deficits in this disorder. To evaluate biological bases that might underlie a reward/motivation deficit by imaging key components of the brain dopamine reward pathway (mesoaccumbens). We used positron emission tomography to measure dopamine synaptic markers (transporters and D{sub 2}/D{sub 3} receptors) in 53 nonmedicated adults with ADHD and 44 healthy controls between 2001-2009 at Brookhaven National Laboratory. We measured specific binding of positron emission tomographic radioligands for dopamine transportersmore » (DAT) using [{sup 11}C]cocaine and for D{sub 2}/D{sub 3} receptors using [{sup 11}C]raclopride, quantified as binding potential (distribution volume ratio -1). For both ligands, statistical parametric mapping showed that specific binding was lower in ADHD than in controls (threshold for significance set at P < .005) in regions of the dopamine reward pathway in the left side of the brain. Region-of-interest analyses corroborated these findings. The mean (95% confidence interval [CI] of mean difference) for DAT in the nucleus accumbens for controls was 0.71 vs 0.63 for those with ADHD (95% CI, 0.03-0.13, P = .004) and in the midbrain for controls was 0.16 vs 0.09 for those with ADHD (95% CI, 0.03-0.12; P {le} .001); for D{sub 2}/D{sub 3} receptors, the mean accumbens for controls was 2.85 vs 2.68 for those with ADHD (95% CI, 0.06-0.30, P = .004); and in the midbrain, it was for controls 0.28 vs 0.18 for those with ADHD (95% CI, 0.02-0.17, P = .01). The analysis also corroborated differences in the left caudate: the mean DAT for controls was 0.66 vs 0.53 for those with ADHD (95% CI, 0.04-0.22; P = .003) and the mean D{sub 2}/D{sub 3} for controls was 2.80 vs 2.47 for those with ADHD (95% CI, 0.10-0.56; P = .005) and differences in D{sub 2}/D{sub 3} in the hypothalamic region, with controls having a mean of 0.12 vs 0.05 for those with ADHD (95% CI, 0.02-0.12; P = .004). Ratings of attention correlated with D{sub 2}/D{sub 3} in the accumbens (r = 0.35; 95% CI, 0.15-0.52; P = .001), midbrain (r = 0.35; 95% CI, 0.14-0.52; P = .001), caudate (r = 0.32; 95% CI, 0.11-0.50; P = .003), and hypothalamic (r = 0.31; CI, 0.10-0.49; P = .003) regions and with DAT in the midbrain (r = 0.37; 95% CI, 0.16-0.53; P {le} .001). A reduction in dopamine synaptic markers associated with symptoms of inattention was shown in the dopamine reward pathway of participants with ADHD.« less

(Ag{sub 2}TeS{sub 3}){sub 2} {small_bullet} A{sub 2}S{sub 6} (A = Rb, Cs) : layers of silver thiotellurite intergrown with alkali-metal polysulfides.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, S. L.; Jang, J. I.; Ketterson, J. B.

2010-09-22

The layered compounds RbAg{sub 2}TeS{sub 6} and CsAg{sub 2}TeS{sub 6} crystallize in the noncentrosymmetric space group P6{sub 3}cm, with a = 19.15 {angstrom}, c = 14.64 {angstrom}, and V = 4648 {angstrom}{sup 3} and a = 19.41 {angstrom}, c = 14.84 {angstrom}, and V = 4839 {angstrom}{sup 3}, respectively. The structures are composed of neutral [Ag{sub 2}TeS{sub 3}] layers alternating with charge-balanced salt layers containing polysulfide chains of [S{sub 6}]{sup 2-} and alkali-metal ions. RbAg{sub 2}TeS{sub 6} and CsAg{sub 2}TeS{sub 6} are air- and water-stable, wide-band-gap semiconductors (E{sub g} {approx} 2.0 eV) exhibiting nonlinear-optical second-harmonic generation.

Syntheses of monomeric (. eta. sup 5 -pentamethylcyclopentadienyl)platinum(IV) methyl and bromo complexes and of (hydrotris(3,5-dimethyl-1-pyrazolyl)borato)trimethylplatinum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roth, S.; Ramamoorthy, V.; Sharp, P.R.

1990-09-05

The reaction of Cp*MgCl{center dot}THF (Cp* = C{sub 5}Me{sub 5}) with 1 equiv of PtMe{sub 3}I and PtMe{sub 2}Br{sub 2} produces Cp*PtMe{sub 3} (1) and Cp*PtMe{sub 2}Br (2), respectively. Reaction of 2 with Br{sub 2} produces Cp*PtMeBr{sub 2} (3) in good yield. The structures of 2 and 3 have been determined by x-ray crystallography, and the crystal structure data are reported. Complex 2 crystallizes in the monoclinic space group, P2{sub 1}/m, and complex 3 crystallizes in the monoclinic space group, P2{sub 1}/m. The molecules reside on mirror planes and are monomeric pseudotetrahedral Pt(IV) complexes with piano stool type geometries andmore » {eta}{sup 5}-Cp* groups. Both molecules have Br atoms on the mirror. This leads to a disorder of the Me and the second Br positions in complex 3. The average Pt-C(Cp*) bond length is 2.25 (7) {angstrom} in 2 and 2.22 (4) {angstrom} in 3. The Pt-C(Me) and Pt-Br bond lengths in 2 are 2.07 (2) and 2.498 (2) {angstrom}, respectively. The ordered Pt-Br bond length in 3 is 2.496 (2) {angstrom}. Treatment of 1 with halogens results in the cleavage of the Pt-Cp* bond. The reaction of PtMe{sub 3}I with KTp* (Tp* = (HB(3,5-dimethylpyrazolyl){sub 3}){sup {minus}}) in thf gives Tp*PtMe{sub 3} (4) in almost quantitative yield. The reaction of 4 with Br{sub 2} brominates the 4-position of the pyrazolyl ring only. 28 refs., 2 figs., 5 tabs.« less

Solid state reaction synthesis and photoluminescence properties of Dy{sup 3+} doped Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12} phosphor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Long, Qiang; Wang, Chuang; Li, Yanyan

2015-11-15

Highlights: • Ca{sub 3−x}Sc{sub 2}Si{sub 3}O{sub 12}:xDy{sup 3+} (0.01 ≤ x ≤ 0.03) was successfully synthesized under a reducing atmosphere. • The thermal stability of the Ca{sub 2.975}Sc{sub 2}Si{sub 3}O{sub 12}:0.025Dy{sup 3+} is superior to commercial phosphors in theory and experiment. • The optimal chromaticity coordinates of Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12}:Dy{sup 3+} is (x = 0.3425, y = 0.3343) upon 350 nm excitation. - Abstract: The white emission phosphor Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12}:Dy{sup 3+} was synthesized by the solid-state reaction. Phase analysis and characteristic luminescence properties are investigated by X-ray diffraction and photoluminescence spectra measurement. Ca{sub 3}Sc{sub 2}Si{submore » 3}O{sub 12}:Dy{sup 3+} phosphor shows strong absorption in 350–410 nm region and exhibits white emission with CIE chromaticity coordinates of (0.3425, 0.3343). Its emission intensity at 250 °C remained 74% of that measured at room temperature. Moreover, the activation energy is also calculated through the Arrhenius equation. The result shows that the thermostability of Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12}:Dy{sup 3+} is superior than that of commercial phosphor Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12}:Ce{sup 3+}. The outstanding luminescent properties indicate that Ca{sub 3}Sc{sub 2}Si{sub 3}O{sub 12}:Dy{sup 3+} could be a potential white light emission phosphor.« less

Evaluation of Biologic Effective Dose and Schedule of Fractionation for Preoperative Radiotherapy for Rectal Cancer: Meta-Analyses and Meta-Regression;Rectal cancer; Preoperative radiotherapy; Biologic effective dose; Meta-analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arruda Viani, Gustavo, E-mail: gusviani@gmail.com; Stefano, Eduardo Jose; Vendito Soares, Francisco

2011-07-15

Purpose: To evaluate whether the risk of local recurrence depends on the biologic effective dose (BED) or fractionation dose in patients with resectable rectal cancer undergoing preoperative radiotherapy (RT) compared with surgery alone. Methods and Materials: A meta-analysis of randomized controlled trials (RCTs) was performed. The MEDLINE, Embase, CancerLit, and Cochrane Library databases were systematically searched for evidence. To evaluate the dose-response relationship, we conducted a meta-regression analysis. Four subgroups were created: Group 1, RCTs with a BED >30 Gy{sub 10} and a short RT schedule; Group 2, RCTs with BED >30 Gy{sub 10} and a long RT schedule; Groupmore » 3, RCTs with BED {<=}30 Gy{sub 10} and a short RT schedule; and Group 4, RCTs with BED {<=}30 Gy{sub 10} and a long RT schedule. Results: Our review identified 21 RCTs, yielding 9,097 patients. The pooled results from these 21 randomized trials of preoperative RT showed a significant reduction in mortality for groups 1 (p = .004) and 2 (p = .03). For local recurrence, the results were also significant in groups 1 (p = .00001) and 2 (p = .00001).The only subgroup that showed a greater sphincter preservation (SP) rate than surgery was group 2 (p = .03). The dose-response curve was linear (p = .006), and RT decreased the risk of local recurrence by about 1.7% for each Gy{sub 10} of BED. Conclusion: Our data have shown that RT with a BED of >30 Gy{sub 10} is more efficient in reducing local recurrence and mortality rates than a BED of {<=}30 Gy{sub 10}, independent of the schedule of fractionation used. A long RT schedule with a BED of >30 Gy{sub 10} should be recommended for sphincter preservation.« less

Complete Al-SI Order in Scapolite Me[subscript 37.5], Ideally Ca[subscript 3]Na[subscript 5][Al[subscript 8]Si[subscript 16]O[subscript 48

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antao, Sytle M.; Hassan, Ishmael; West Indies)

2011-09-06

The structure of an intermediate scapolite (Me{sub 36.6}) from Lake Clear, Ontario, was obtained using synchrotron high-resolution powder X-ray diffraction (HRPXRD) data and Rietveld structure refinement in space group P4{sub 2}/n. The chemical formula obtained by electron microprobe is Na{sub 2.19}Ca{sub 1.35}K{sub 0.16}[Al{sub 3.95}Si{sub 8.05}O{sub 24}]Cl{sub 0.55}(CO{sub 3}){sub 0.41}(SO{sub 4}){sub 0.04}, equivalent to Me{sub 36.6}. The unit-cell parameters are a 12.07899(1), c 7.583467(9) {angstrom}, and V 1106.443(2) {angstrom}{sup 3}. The average distances are = 1.617(1) {angstrom}, = 1.744(1) {angstrom}, and = 1.601(1) {angstrom}. Therefore, the T1 and T3 sites contain only Si atoms, and the T2 sitemore » contains only Al atoms, so the Al and Si atoms are completely ordered. Complete Al-Si order was predicted for Me{sub 37.5}, ideally Ca{sub 3}Na{sub 5}[Al{sub 8}Si{sub 16}O{sub 48}]Cl(CO{sub 3}), and is confirmed in this study. Antiphase domain boundaries (APBs) in scapolite cannot arise from Al-Si order because the average distances indicate complete Al-Si order in Me{sub 36.6}. If APBs were to arise from Al-Si order, switching of the T sites across the APBs will occur, and complete Al-Si order cannot be observed. Therefore, Al-Si order, which is present to various extents across the scapolite series, can be ruled out as the cause for the APBs. Order involving Cl and CO{sub 3} is the cause for the APBs in scapolite.« less

Rietveld refinement and ionic conductivity of Ca{sub 8.4}Bi{sub 1.6}(PO{sub 4}){sub 6}O{sub 1.8}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tmar Trabelsi, I., E-mail: ilhem_tmar@yahoo.fr; Madani, A.; Mercier, A.M.

2013-01-15

The structure of Ca{sub 8.4}Bi{sub 1.6}(PO{sub 4}){sub 6}O{sub 1.8}, isostructural with Fluoroapatite, was determined by X-ray powder diffraction methods. The results of Rietveld refinement revealed that the formula of this compound is [Ca{sub 4}]{sup 4f}[Ca{sub 4.4}Bi{sub 1.6}]{sup 6h}(PO{sub 4}){sub 6}[O{sub 1.8}]{sup 2a}, space group P63/m (a=9.468 (3) A, c=6.957 (3) A). A total substitution of Bi{sup 3+} ions in the (6h) sites was related particularly to the high polarizability of the Bi{sup 3+} ion compared to Ca{sup 2+}. The observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses and inmore » comparison with Fluoroapatite and other oxyapatites. The ionic conductivity over a wide range of temperature was investigated according to the complex impedance method. The highest overall conductivity values were found at {sigma}{sub 700 Degree-Sign C} =5.03 Multiplication-Sign 10{sup -7} S cm{sup -1} and E{sub a}=0.50 eV. - Graphical abstract: The final Rietveld refinement plot of the Ca{sub 8.4}Bi{sub 1.6} (PO{sub 4}){sub 6}O{sub 1.8}. Highlights: Black-Right-Pointing-Pointer The Rietveld refinement revealed that the formula of this compound is Ca{sub 8.4}Bi{sub 1.6}(PO{sub 4}){sub 6}O{sub 1.8}. Black-Right-Pointing-Pointer Vibrational spectroscopy supports the high symmetry P63/m space group for this apatite. Black-Right-Pointing-Pointer This apatite contained channels where oxygen ions were located in 2a sites. Black-Right-Pointing-Pointer The possibility of anionic conduction along these channels was considered.« less

Functionalized Congeners of P2Y1 Receptor Antagonists:

DOE Office of Scientific and Technical Information (OSTI.GOV)

de Castro, Sonia; Maruoka, Hiroshi; Hong, Kunlun

2010-01-01

The P2Y{sub 1} receptor is a prothrombotic G protein-coupled receptor (GPCR) activated by ADP. Preference for the North (N) ring conformation of the ribose moiety of adenine nucleotide 3',5'-bisphosphate antagonists of the P2Y{sub 1} receptor was established by using a ring-constrained methanocarba (a bicyclo[3.1.0]hexane) ring as a ribose substitute. A series of covalently linkable N{sup 6}-methyl-(N)-methanocarba-2'-deoxyadenosine-3',5'-bisphosphates containing extended 2-alkynyl chains was designed, and binding affinity at the human (h) P2Y{sub 1} receptor determined. The chain of these functionalized congeners contained hydrophilic moieties, a reactive substituent, or biotin, linked via an amide. Variation of the chain length and position of anmore » intermediate amide group revealed high affinity of carboxylic congener 8 (K{sub i} 23 nM) and extended amine congener 15 (K{sub i} 132 nM), both having a 2-(1-pentynoyl) group. A biotin conjugate 18 containing an extended {epsilon}-aminocaproyl spacer chain exhibited higher affinity than a shorter biotinylated analogue. Alternatively, click coupling of terminal alkynes of homologous 2-dialkynyl nucleotide derivatives to alkyl azido groups produced triazole derivatives that bound to the P2Y{sub 1} receptor following deprotection of the bisphosphate groups. The preservation of receptor affinity of the functionalized congeners was consistent with new P2Y{sub 1} receptor modeling and ligand docking. Attempted P2Y{sub 1} antagonist conjugation to PAMAM dendrimer carriers by amide formation or palladium-catalyzed reaction between an alkyne on the dendrimer and a 2-iodopurine-derivatized nucleotide was unsuccessful. A dialkynyl intermediate containing the chain length favored in receptor binding was conjugated to an azide-derivatized dendrimer, and the conjugate inhibited ADP-promoted human platelet aggregation. This is the first example of attaching a strategically functionalized P2Y receptor antagonist to a PAMAM dendrimer to produce a multivalent conjugate exhibiting a desired biological effect, i.e., antithrombotic action.« less

Optical gain for the interband optical transition in InAsP/InP quantum well wire in the influence of laser field intensity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saravanan, S.; Peter, A. John, E-mail: a.john.peter@gmail.com

Intense high frequency laser field induced electronic and optical properties of heavy hole exciton in the InAs{sub 0.8}P{sub 0.2}/InP quantum wire is studied taking into account the geometrical confinement effect. Laser field related exciton binding energies and the optical band gap in the InAs{sub 0.8}P{sub 0.2}/InP quantum well wire are investigated. The optical gain, for the interband optical transition, as a function of photon energy, in the InAs{sub 0.8}P{sub 0.2}/InP quantum wire, is obtained in the presence of intense laser field. The compact density matrix method is employed to obtain the optical gain. The obtained optical gain in group III-Vmore » narrow quantum wire can be applied for achieving the preferred telecommunication wavelength.« less

TREATMENT OF 1,2-DIBROMO-3-CHLOROPROPANE AND NITRATE-CONTAMINATED WATER WITH ZERO-VALENT IRON OR HYDROGEN/PALLADIUM CATALYSTS. (R825689C054,R825689C078)

EPA Science Inventory

Abstract

The abilities of zero-valent iron powder and hydrogen with a palladium catalyst (H₂/Pd-alumina) to hydrodehalogenate 1,2-dibromo-3-chloropropane (DBCP) to propane under water treatment conditions (ambient temperature and circumneutral pH) were compa...

Ce{sub 2}PdIn{sub 8}, Ce{sub 3}PdIn{sub 11} and Ce{sub 5}Pd{sub 2}In{sub 19}—members of homological series based on AuCu{sub 3}- and PtHg{sub 2}-type structural units

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tursina, A.; Nesterenko, S.; Seropegin, Y.

Crystal structures of three members of a unique homological series with the general formula Ce{sub m}Pd{sub n}In{sub 3m+2n} based on the AuCu{sub 3} and PtHg{sub 2} structure types were studied by single-crystal X-ray diffraction. The compounds crystallize with space group P4/mmm (Z=1) and the lattice parameters: a=4.6900(9) Å, c=12.185(6) Å for Ce{sub 2}PdIn{sub 8}, a=4.6846(8) Å, c=16.846(8) Å for Ce{sub 3}PdIn{sub 11}, and a=4.70120(10) Å, c=29.1359(4) Å for Ce{sub 5}Pd{sub 2}In{sub 19}. The crystal structures of Ce{sub 3}PdIn{sub 11} and Ce{sub 5}Pd{sub 2}In{sub 19} represent new types. The three structures constitute of [CeIn{sub 3}] cuboctahedra layers and [PdIn{sub 2}] rectangularmore » polyhedra layers, alternating along the tetragonal c-axis in accordance with the m:n proportion. The magnetic and electrical transport properties of the novel compounds Ce{sub 3}PdIn{sub 11} and Ce{sub 5}Pd{sub 2}In{sub 19} were investigated down to 1.72 K. Both indides are Curie–Weiss paramagnets due to the presence of fairly well localized 4f electrons of trivalent cerium ions. The electrical resistivity of both materials is dominated over an extended temperature range by strong spin–flip Kondo interactions with the characteristic temperature scale of 20–30 K. - Graphical abstract: TOC Figure Crystal structures of Ce{sub 3}PdIn{sub 11}, Ce{sub 2}PdIn{sub 8}, and Ce{sub 5}Pd{sub 2}In{sub 19}. Highlights: ► Large section of Ce–Pd–In phase diagram was examined. ► Three distinct ternary phases were identified, two of them for the first time. ► Crystal structures of two novel compounds constitute new structure types. ► The determined crystal structures show close mutual relationship. ► Ce{sub 3}PdIn{sub 11} and Ce{sub 5}Pd{sub 2}In{sub 19} are paramagnetic Kondo lattices.« less

Bi-substituted iron garnet films for one-dimensional magneto-photonic crystals: Synthesis and properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaposhnikov, A.N.; Karavainikov, A.V.; Prokopov, A.R.

2012-06-15

Graphical abstract: Faraday hysteresis loops for Bi{sub 1.0}Y{sub 0.5}Gd{sub 1.5}Fe{sub 4.2}Al{sub 0.8}O{sub 12} film on glass-ceramic substrate (a), Bi{sub 2.8}Y{sub 0.2}Fe{sub 5}O{sub 12} film on gallium–gadolinium garnet (b) and for glass-ceramic/SiO{sub 2}/Bi{sub 1.0}Y{sub 0.5}Gd{sub 1.5}Fe{sub 4.2}Al{sub 0.8}O{sub 12}/Bi{sub 2.8}Y{sub 0.2}Fe{sub 5}O{sub 12} structure (c). Highlights: ► Bismuth-substituted iron garnet films as magneto-optical layers in magneto-photonic crystals. ► It is impossible to crystallize the films with high Bi content on amorphous substrates. ► The crystallization of the films can be achieved by their deposition on buffer layer with low bismuth content. -- Abstract: The crystallization processes in Bi{sub 2.8}Y{sub 0.2}Fe{sub 5}O{submore » 12}, Bi{sub 2.5}Gd{sub 0.5}Fe{sub 3.8}Al{sub 1.2}O{sub 12}, Bi{sub 1.5}Gd{sub 1.5}Fe{sub 4.5}Al{sub 0.5}O{sub 12} and Bi{sub 1.0}Y{sub 0.5}Gd{sub 1.5}Fe{sub 4.2}Al{sub 0.8}O{sub 12} garnet films deposited by reactive ion beam sputtering on (1 1 1) gadolinium–gallium garnet substrates, optical glass-ceramic and SiO{sub 2} films have been studied. Films were annealed at low pressure in oxygen atmosphere and in the air. The possibility of preparation of crystalline garnet films with high concentration of bismuth on the SiO{sub 2} films using a buffer layer with low concentration of Bi has been shown. This allows to produce one-dimensional magneto-photonic crystals with high effective Faraday rotation (several tens of°/μm for the visible optical spectrum).« less

Exchange coupling transformations in Cu (II) heterospin complexes of “breathing crystals” under structural phase transitions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morozov, Vitaly A.; Petrova, Marina V.; Lukzen, Nikita N., E-mail: luk@tomo.nsc.ru

2015-08-15

Family of “breathing crystals” is the polymer-chain complexes of Cu(hfac){sub 2} with nitroxides. The polymer chains consist of one-, two- or three-spin clusters. The “breathing crystals” experience simultaneous magnetic and Jahn-Teller type structural phase transitions with change of total cluster spin and drastic change of bond lengths (ca. 10-12%). For the first time the intra-cluster magnetic couplings in ”breathing crystals” have been calculated both by band structure methods GGA + U and hybrid DFT (B3LYP and PBE0) for the isolated exchange clusters. The temperature dependence of the magnetic coupling constant was calculated for two polymer-chain compounds of the “breathing crystal”more » family - C{sub 21}H{sub 19}CuF{sub 12}N{sub 4}O{sub 6} with the chains containing two-spin clusters and C{sub 22}H{sub 21}CuF{sub 12}N{sub 4}O{sub 6} with the chains of alternating three-spin clusters and one-spin sites. It was found that adding a Hubbard-like parameter not only to the copper 3d electrons but also to the oxygen 2p electrons (GGA + U{sub d} + U{sub p} approach) results in an improved description of exchange coupling in the “breathing crystal” compounds. At the same time treatment of the isolated clusters by a large basis hybrid DFT with high computational cost provides a similar quality fit of the experimental magneto-chemical data as that for the GGA + U{sub d} + U{sub p} band structure calculation scheme. Our calculations also showed that in spite of the abrupt transformation of the magnetic coupling constant under the phase transition, the band gap in the “breathing crystals” remains about the same value with temperature decrease.« less

Sol-gel synthesis of K{sub 3}InF{sub 6} and structural characterization of K{sub 2}InC{sub 10}O{sub 10}H{sub 6}F{sub 9}, K{sub 3}InC{sub 12}O{sub 14}H{sub 4}F{sub 18} and K{sub 3}InC{sub 12}O{sub 12}F{sub 18}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Labeguerie, Jessica; Gredin, Patrick; Marrot, Jerome

2005-10-15

K{sub 3}InF{sub 6} is synthesized by a sol-gel route starting from indium and potassium acetates dissolved in isopropanol in the stoichiometry 1:3, with trifluoroacetic acid as fluorinating agent. The crystal structures of the organic precursors were solved by X-ray diffraction methods on single crystals. Three organic compounds were isolated and identified: K{sub 2}InC{sub 10}O{sub 10}H{sub 6}F{sub 9}, K{sub 3}InC{sub 12}O{sub 14}H{sub 4}F{sub 18} and K{sub 3}InC{sub 12}O{sub 12}F{sub 18}. The first one, deficient in potassium in comparison with the initial stoichiometry, is unstable. In its crystal structure, acetate as well as trifluoroacetate anions are coordinated to the indium atom. Themore » two other precursors are obtained, respectively, by quick and slow evaporation of the solution. They correspond to the final organic compounds, which give K{sub 3}InF{sub 6} by decomposition at high temperature. The crystal structure of K{sub 3}InC{sub 12}O{sub 14}H{sub 4}F{sub 18} is characterized by complex anions [In(CF{sub 3}COO){sub 4}(OH{sub x}){sub 2}]{sup (5-2x)-} and isolated [CF{sub 3}COOH{sub 2-x}]{sup (x-1)-} molecules with x=2 or 1, surrounded by K{sup +} cations. The crystal structure of K{sub 3}InC{sub 12}O{sub 12}F{sub 18} is only constituted by complex anions [In(CF{sub 3}COO){sub 6}]{sup 3-} and K{sup +} cations. For all these compounds, potassium cations ensure only the electroneutrality of the structure. IR spectra of K{sub 2}InC{sub 10}O{sub 10}H{sub 6}F{sub 9} and K{sub 3}InC{sub 12}O{sub 12}F{sub 18} were also performed at room temperature on pulverized crystals.« less

Study of the hadronic decays of {chi}{sub c} states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bai, J.Z.; Bian, J.G.; Chen, G.P.

1999-10-01

Hadronic decays of the {ital P}-wave spin-triplet charmonium states {chi}{sub cJ}(J=0,1,2) are studied using a sample of {psi}(2S) decays collected by the BES detector operating at the BEPC storage ring. Branching fractions for the decays {chi}{sub c1}{r_arrow}K{sub S}{sup 0}K{sup +}{pi}{sup {minus}}+c.c., {chi}{sub c0}{r_arrow}K{sub S}{sup 0}K{sub S}{sup 0}, {chi}{sub c2}{r_arrow}K{sub S}{sup 0}K{sub S}{sup 0}, {chi}{sub c0}{r_arrow}{phi}{phi}, {chi}{sub c2}{r_arrow}{phi}{phi} and {chi}{sub cJ}{r_arrow}K{sup +}K{sup {minus}}K{sup +}K{sup {minus}} are measured for the first time, and those for {chi}{sub cJ}{r_arrow}{pi}{sup +}{pi}{sup {minus}}{pi}{sup +}{pi}{sup {minus}}, {chi}{sub cJ}{r_arrow}{pi}{sup +}{pi}{sup {minus}}K{sup +}K{sup {minus}}, {chi}{sub cJ}{r_arrow}{pi}{sup +}{pi}{sup {minus}}p{bar p} and {chi}{sub cJ}{r_arrow}3({pi}{sup +}{pi}{sup {minus}}) are measured with improved precision.more » In addition, we determine the masses of the {chi}{sub c0} and {eta}{sub c} to be M{sub {chi}{sub c0}}=3414.1{plus_minus}0.6(stat){plus_minus}0.8(syst) MeV and M{sub {eta}{sub c}}=2975.8{plus_minus}3.9(stat){plus_minus}1.2(syst) MeV. {copyright} {ital 1999} {ital The American Physical Society}« less

Kinetic Mechanism and Rate-Limiting Steps of Focal Adhesion Kinase-1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneck, Jessica L.; Briand, Jacques; Chen, Stephanie

2010-12-07

Steady-state kinetic analysis of focal adhesion kinase-1 (FAK1) was performed using radiometric measurement of phosphorylation of a synthetic peptide substrate (Ac-RRRRRRSETDDYAEIID-NH{sub 2}, FAK-tide) which corresponds to the sequence of an autophosphorylation site in FAK1. Initial velocity studies were consistent with a sequential kinetic mechanism, for which apparent kinetic values k{sub cat} (0.052 {+-} 0.001 s{sup -1}), K{sub MgATP} (1.2 {+-} 0.1 {micro}M), K{sub iMgATP} (1.3 {+-} 0.2 {micro}M), K{sub FAK-tide} (5.6 {+-} 0.4 {micro}M), and K{sub iFAK-tide} (6.1 {+-} 1.1 {micro}M) were obtained. Product and dead-end inhibition data indicated that enzymatic phosphorylation of FAK-tide by FAK1 was best described bymore » a random bi bi kinetic mechanism, for which both E-MgADP-FAK-tide and E-MgATP-P-FAK-tide dead-end complexes form. FAK1 catalyzed the {beta}{gamma}-bridge:{beta}-nonbridge positional oxygen exchange of [{gamma}-{sup 18}O{sub 4}]ATP in the presence of 1 mM [{gamma}-{sup 18}O{sub 4}]ATP and 1.5 mM FAK-tide with a progressive time course which was commensurate with catalysis, resulting in a rate of exchange to catalysis of k{sub x}/k{sub cat} = 0.14 {+-} 0.01. These results indicate that phosphoryl transfer is reversible and that a slow kinetic step follows formation of the E-MgADP-P-FAK-tide complex. Further kinetic studies performed in the presence of the microscopic viscosogen sucrose revealed that solvent viscosity had no effect on k{sub cat}/K{sub FAK-tide}, while k{sub cat} and k{sub cat}/K{sub MgATP} were both decreased linearly at increasing solvent viscosity. Crystallographic characterization of inactive versus AMP-PNP-liganded structures of FAK1 showed that a large conformational motion of the activation loop upon ATP binding may be an essential step during catalysis and would explain the viscosity effect observed on k{sub cat}/K{sub m} for MgATP but not on k{sub cat}/K{sub m} for FAK-tide. From the positional isotope exchange, viscosity, and structural data it may be concluded that enzyme turnover (k{sub cat}) is rate-limited by both reversible phosphoryl group transfer (k{sub forward} {approx} 0.2 s{sup -1} and k{sub reverse} {approx} 0.04 s{sup -1}) and a slow step (k{sub conf} {approx} 0.1 s{sup -1}) which is probably the opening of the activation loop after phosphoryl group transfer but preceding product release.« less

Effect of electrical stimulation of the lower esophageal sphincter in gastroesophageal reflux disease patients refractory to proton pump inhibitors

PubMed Central

Soffer, Edy; Rodríguez, Leonardo; Rodriguez, Patricia; Gómez, Beatriz; Neto, Manoel G; Crowell, Michael D

2016-01-01

AIM: To evaluate the efficacy of lower esophageal sphincter (LES)-electrical stimulation therapy (EST) in a subgroup of patients that reported only partial response to proton pump inhibitors (PPIs) therapy, compared to a group of patient with complete response. METHODS: Bipolar stitch electrodes were laparoscopically placed in the LES and connected to an implantable pulse generator (EndoStim BV, the Hague, the Netherlands), placed subcutaneously in the anterior abdominal wall. Stimulation at 20 Hz, 215 μsec, 3-8 mAmp in 30 min sessions was delivered starting on day 1 post-implant. Patients were evaluated using gastroesophageal reflux disease (GERD)-HRQL, symptom diaries; esophageal pH and esophageal manometry before and up to 24 mo after therapy and results were compared between partial and complete responders. RESULTS: Twenty-three patients with GERD on LES-EST were enrolled and received continuous per-protocol stimulation through 12 mo and 21 patients completed 24 mo of therapy. Of the 23 patients, 16 (8 male, mean age 52.1 ± 12 years) had incomplete response to PPIs prior to LES-EST, while 7 patients (5 male, mean age 52.7 ± 4.7) had complete response to PPIs. In the sub-group with incomplete response to PPIs, median (IQR) composite GERD-HRQL score improved significantly from 9.5 (9.0-10.0) at baseline on-PPI and 24.0 (20.8-26.3) at baseline off-PPI to 2.5 (0.0-4.0) at 12-mo and 0.0 (0.0-2.5) at 24-mo follow-up (P < 0.05 compared to on-and off-PPI at baseline). Median (IQR) % 24-h esophageal pH < 4.0 at baseline in this sub-group improved significantly from 9.8% (7.8-11.5) at baseline to 3.0% (1.9-6.3) at 12 mo (P < 0.001) and 4.6% (2.0-5.8) at 24 mo follow-up (P < 0.01). At their 24-mo follow-up, 9/11 patients in this sub-group were completely free of PPI use. These results were comparable to the sub-group that reported complete response to PPI therapy at baseline. No unanticipated implantation or stimulation-related adverse events, or any untoward sensation due to stimulation were reported in either group and LES-EST was safely tolerated by both groups. CONCLUSION: LES-EST is safe and effective in controlling symptoms and esophageal acid exposure in GERD patients with incomplete response to PPIs. These results were comparable to those observed PPI responders. PMID:26855821

Hyperfine structure and isotope shift of /sup 208/Bi in the 3067-A resonance line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lamontagne, J.J.

1982-01-01

The hyperfine structure of /sup 208/Bi (I = 5) was measured using the 3067 A spectral line from the 6p/sup 2/7s (/sup 4/P/sub 1/2/) - 6p/sup 3/ (/sup 4/S/sub 3/2/) transition. After production of the isotope at the Princeton University Cyclotron, chemical separation, and mass separation, some 10/sup 12/ atoms were used to produce an absorption spectrum. The monochromator, Czerny-Turner design), had a 9.1 m focal length with a 25 cm diffraction grating used in autocollimation near 63/sup 0/. The spectrum was recorded on photographic plates. Measurements were made of the position of the components. From these the value /supmore » 208/A (/sup 4/P/sub 1/2) = 166 (1.5) mK was obtained. Neglecting hyperfine anomalies this gives /sup 208/A (/sup 4/S/sub 3/2/) = 15.07 (.1). The isotope shift /sup 208/Bi-/sup 208/Bi was measured to be 50.58 (7.5) mK.« less

Investigation of carbon-coated lithiated Li{sub 4+x}Ti{sub 5}O{sub 12}/C for lithium-ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Mengjie; Zhang, Lin; Gong, Lijun

2015-11-15

Highlights: • Lithiated Li{sub 4+x}Ti{sub 5}O{sub 12}/C with pre-stored active Li ions has been synthesized. • The first-cycle coulombic efficiency of Li{sub 4+x}Ti{sub 5}O{sub 12}/C is over 100%. • Li{sub 4+x}Ti{sub 5}O{sub 12}/C displays excellent cyclic stability and capacity retention. • TiO{sub 2} nanoparticles and carbon coating are necessary for formation of Li{sub 4+x}Ti{sub 5}O{sub 12}/C. - Abstract: Carbon-coated Li{sub 4}Ti{sub 5}O{sub 12} and lithiated Li{sub 4+x}Ti{sub 5}O{sub 12} anode materials have been synthesized using nanosized anatase TiO{sub 2} and commercial TiO{sub 2} with mixed structure as Ti sources, respectively. Microstructural investigation indicates that Li{sub 4}Ti{sub 5}O{sub 12} and Li{submore » 4+x}Ti{sub 5}O{sub 12} are covered by amorphous carbon layers with thickness of 2–3 nm. Their electrochemical performance has been evaluated, which indicates that an amount of active Li ions have been pre-stored in the Li{sub 4+x}Ti{sub 5}O{sub 12} lattice during solid-state synthesis, resulting in its first-cycle coulombic efficiency over 100%. Further, Li{sub 4+x}Ti{sub 5}O{sub 12}/C exhibits higher cyclic capacities than Li{sub 4}Ti{sub 5}O{sub 12}/C at different current density. The reversible charge capacity retention of Li{sub 4+x}Ti{sub 5}O{sub 12}/C reaches 98.5% after 100 cycles, which indicates that Li{sub 4+x}Ti{sub 5}O{sub 12}/C is promising candidate anode material for long lifetime lithium-ion batteries. The formation mechanism of Li{sub 4+x}Ti{sub 5}O{sub 12}/C has been discussed, in which the nanosized anatase TiO{sub 2} with high chemical activity and the carbon coating play key roles for the formation of Li{sub 4+x}Ti{sub 5}O{sub 12}/C.« less

Acid-base properties of aqueous illite surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Du, Q.; Sun, Z.; Forsling, W.

In this paper, the acid-base properties of illite/water suspensions are examined using the constant capacitance surface complexation model. On the basis of results of potentiometric titrations and solubility experiments, the authors conclude that the proton reactions in the supernatants of illite suspensions can be successfully represented by proton reactions of Al(H{sub 2}O){sub 6}{sup 3+} and Si(OH){sub 4} in water solutions. For illustrating the acidic characteristics of aqueous illite surfaces, two surface protonation models are proposed: (1) one site-one pK{sub a} model, {triple_bond}SOH {r_reversible} {triple_bond}SO{sup {minus}} + H{sup +}, pK{sub a}{sup int} = 4.12-4.23; (2) two sites-two pK{sub a}s model, {triple_bond}S{submore » 1}OH {r_reversible} {triple_bond}S{sup 1}O{sup {minus}} + H{sup +}, pK{sub a{sub I}} = 4.17-4.44, and {triple_bond}S{sub II}OH {r_reversible} {triple_bond}S{sub II}O{sup {minus}} + H{sup +}, pK{sub a{sub II}}{sup int} = 6.35-7.74. Evaluation of these two models indicates that both of them can give good descriptions of the experimental data of systems with different illite concentrations and ionic strengths and that the one site-one pK{sub a} model can be considered as a simplification of the two sites-two pK{sub a}s model. Since both models assume only deprotonation reactions at the illite surfaces, they suggest that the surface behavior of the illite is similar to that of amorphous SiO{sub 2}. Model assumptions, experimental procedures, and evaluative criteria are detailed in the paper.« less

Effects of exposure to NO{sub 2} or SO{sub 2} on bronchopulmonary reaction induced by Candida albicans in guinea pigs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kitabatake, Masayoshi; Yamamoto, Hidetaka; Yuan, Piao Feng

1995-09-01

The effects of NO{sub 2} or SO{sub 2} on the bronchopulmonary reactions induced by Candida albicans in guinea pigs were evaluated. Thirty-six guinea pigs (3 groups of 12 animals each) were sensitized with intraperitoneal injection of 10 mg of C. albicans, given twice. Two groups of animals were exposed to about 5 ppm of NO{sub 2} or SO{sub 2} for 4 h/d, 5 d/wk; this exposure was conducted a total of 30 times during the study. The third group served as the control and was not exposed to these pollutants. Two weeks after the second sensitization, all the animals weremore » subjected to inhalation exposure to C. albicans. For 42 h after the antigen challenge, the respiratory rates and expiration/inspiration ratios of the animals were automatically monitored. The number of animals showing tachypnea was significantly higher in the NO{sub 2} exposure group than in the control from 15 h after antigen challenge. In the SO{sub 2} exposure group, the number of animals showing prolonged expiration or prolonged inspiration, or both, was significantly higher than that in the control group, and the symptoms were observed from approximately 15 h after antigen challenge. These findings showed that delayed-type dyspneic symptoms in guinea pigs were increased by exposure to NO{sub 2} or SO{sub 2}, although the symptoms and degree of dyspnea were different for the two gases. 29 refs., 2 figs., 2 tabs.« less

Preparation, structure, and luminescence of dinuclear lanthanide complexes of a novel imine-amine phenolate macrocycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, K.D.; Kahwa, I.A.; Williams, D.J.

1994-03-30

Metal-free condensation of 2,6-diformyl-p-cresol with 3,6-dioxa-1,8-octanediamine followed by reduction with sodium tetrahydroborate and addition of lanthanide(III) nitrate salts, in that order, yield (slowly) crystalline dinuclear complexes of a novel imine-amine phenolate macrocycle 2. The decacoordination geometry of the identical Pr[sup 3+] ions in a C[sub 2v] 4A,6B-extended dodecahedron made up of two bidentate NO[sub 3]-ions, two phenolate and two either oxygens, and one imine and one amine nitrogens. Dinuclear lanthanide complexes of 2 appear to be more stable than those of the totally reduced chelate 2 in alcoholic media. The Tb[sub 2]2(NO[sub 3])[sub 4][center dot]1.2CH[sub 3]-OH and (La[sub 0.97]Tb[sub 0.03])[submore » 2]2(NO[sub 3])[sub 4][center dot]1.2CH[sub 3]OH compounds exhibit strong Tb[sup 3+] ([sup 5]D[sub 4] [yields] [sup 7]F[sub J]) emission sensitized by the single state of 2 at both 77 and 295 K. No Tb[sup 3+]-Tb[sup 3+] self-quenching or N-H trapping effects are observed at 77 K (decay rate is 598 s[sup [minus]1]); the coordination cavities of 2 are therefore potentially good hosts for Tb[sup 3+] in luminescent diagnostic agents. At room temperature the complex decay kinetics of Tb[sup 3+] in Tb[sub 2]2(NO[sub 3])[sub 4][center dot]1.2CH[sub 3]OH are similar to those of Tb[sub 2]1(NO[sub 3])[sub 4][center dot]H[sub 2]O. But for the dilute complex, (La[sub 0.97]-Tb[sub 0.03])[sub 2]2(NO[sub 3])[sub 4][center dot]1.35CH[sub 3]OH, unusual thermal equilibration of the ligand triplet and Tb[sup 3+] [sup 5]D[sub 4] states occurs at room temperature; the ligand-to-Tb[sup 3+] energy-transfer rate is [approx]4.36 x 10[sup 4] s[sup [minus]1], while Tb[sup 3+]-to-ligand back-energy-transfer is [approx]7.1 x 10[sup 4] s[sup [minus]1].« less

Thermal barrier coatings for turbine components

DOEpatents

Subramanian, Ramesh; Sabol, Stephen M.; Goedjen, John G.; Sloan, Kelly M.; Vance, Steven J.

2002-01-01

A turbine component, such as a turbine blade having a metal substrate (22) is coated with a metal MCrAlY alloy layer (24) and then a thermal barrier layer (20) selected from LaAlO.sub.3, NdAlO.sub.3, La.sub.2 Hf.sub.2 O.sub.7, Dy.sub.3 Al.sub.5 O.sub.12, HO.sub.3 Al.sub.3 O.sub.12, ErAlO.sub.3, GdAlO.sub.3, Yb.sub.2 Ti.sub.2 O.sub.7, LaYbO.sub.3, Gd.sub.2 Hf.sub.2 O.sub.7 or Y.sub.3 Al.sub.5 O.sub.12.

Molten salt flux synthesis and crystal structure of a new open-framework uranyl phosphate Cs{sub 3}(UO{sub 2}){sub 2}(PO{sub 4})O{sub 2}: Spectroscopic characterization and cationic mobility studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yagoubi, S., E-mail: said.yagoubi@cea.fr; Renard, C.; Abraham, F.

2013-04-15

The reaction of triuranyl diphosphate tetrahydrate precursor (UO{sub 2}){sub 3}(PO{sub 4}){sub 2}(H{sub 2}O){sub 4} with a CsI flux at 750 °C yields a yellow single crystals of new compound Cs{sub 3}(UO{sub 2}){sub 2}(PO{sub 4})O{sub 2}. The crystal structure (monoclinic, space group C2/c, a=13.6261 (13) Å, b=8.1081(8) Å, c=12.3983(12) Å, β=114.61(12)°, V=1245.41(20) Å{sup 3} with Z=4) has been solved using direct methods and Fourier difference techniques. A full-matrix least-squares refinement on the basis of F{sup 2} yielded R1=0.028 and wR2=0.071 for 79 parameters and 1352 independent reflections with I≥2σ(I) collected on a BRUKER AXS diffractometer with MoKα radiation and a charge-coupledmore » device detector. The crystal structure is built by two independent uranium atoms in square bipyramidal coordination, connected by two opposite corners to form infinite chains {sup 1}{sub ∞}[UO{sub 5}] and by one phosphorus atom in a tetrahedral environment PO{sub 4}. The two last entities {sup 1}{sub ∞}[UO{sub 5}] and PO{sub 4} are linked by sharing corners to form a three-dimensional structure presenting different types of channels occupied by Cs{sup +} alkaline cations. Their mobility within the tunnels were studied between 280 and 800 °C and compared with other tunneled uranyl minerals. The infrared spectrum shows a good agreement with the values inferred from the single crystal structure analysis of uranyl phosphate compound. - Graphical abstract: Arrhenius plot of the electrical conductivity of tunneled compounds Cs{sub 3}U{sub 2}PO{sub 10} and CsU{sub 2}Nb{sub 2}O{sub 11.5}. Highlights: ► The reaction of (UO{sub 2}){sub 3}(PO{sub 4}){sub 2}(H{sub 2}O){sub 4} in excess of molten CsI leads to single-crystals of new tunneled compound Cs{sub 3}(UO{sub 2}){sub 2}(PO{sub 4})O{sub 2}. ► Ionic conductivity measurements and crystal structure analysis indicate a strong connection of the Cs{sup +} cations to the tunnels. ► A low symmetry in Cs{sub 3}(UO{sub 2}){sub 2}(PO{sub 4})O{sub 2} is the cause of IR activation and splitting of the bands in the IR spectrum.« less

Preemptive analgesia in rhegmatogenous retinal detachment surgery: is it effective?

PubMed

Mahfouz, Abdul Kader M; Nabawi, Khaled S

2002-10-01

To evaluate the efficacy of preemptive analgesia in surgical repair of retinal detachment (RD) using scleral buckle and cryopexy under general anesthesia. Thirty patients who were scheduled for rhegmatogenous RD surgical repair using scleral buckle and cryopexy and who were American Society of Anesthesiologists physical status I, II, or III were included in this study. The patients were randomly divided into two equal groups. The surgery was done under general anesthesia in both groups, but in Group 2, sub-Tenon anesthesia was given as preemptive analgesia after induction anesthesia and before start of surgery. Both groups were statistically comparable as regards patient age and weight and duration of anesthesia and surgery. The incidences of intraoperative oculocardiac reflex and postoperative vomiting were significantly lower in Group 2 compared with Group 1 (P < 0.001 and 0.0113, respectively). The time of first postoperative analgesic dose was significantly shorter in Group 1 (46.67 +/- 18.84 minutes) compared with Group 2 (162.67 +/- 29.391 minutes) (P < 0.001). The total analgesic consumption per 24 hours was significantly higher in Group 1 compared with Group 2 (P < 0.001). The time of discharge from the hospital was significantly shorter in Group 2 (8.8 +/- 2.704 hours) compared with Group 1 (12.4 +/- 3.481 hours) (P = 0.0018). The use of sub-Tenon block as preemptive analgesia after induction of general anesthesia and before the start of rhegmatogenous RD surgical repair was effective in reducing postoperative pain and analgesic requirements compared with an unblocked group. The use of sub-Tenon block was also effective in reducing intraoperative incidence of oculocardiac reflex and postoperative incidence of vomiting.

Experimental and ab initio studies on sub-lattice ordering and magnetism in Co{sub 2}Fe(Ge{sub 1−x}Si{sub x}) alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deka, Bhargab; Kundu, Ashis; Ghosh, Subhradip

2015-10-07

Crystallographic and magnetic properties of bulk Co{sub 2}Fe(Ge{sub 1−x}Si{sub x}) alloys with 0 ≤ x ≤ 1, synthesized by arc melting method, have been studied. Co{sub 2}FeSi alloy has been found to crystallize with L2{sub 1} structure, but the super-lattice peaks are absent in the X-ray diffraction patterns of alloys containing high Ge concentration. Unit cell volume of this series of alloys decreased from 185.2 to 178.5 Å{sup 3} as Si content was increased from 0 to 1.00. All alloy compositions exhibit ferromagnetic behavior with a high Curie temperature (T{sub C}). T{sub C} showed a systematic variation with x. A comparison between the valuesmore » of saturation magnetization (M{sub s}) and effective moment per magnetic atom p{sub c} estimated from the temperature dependent susceptibility data above T{sub C}, shows that the alloys have half-metallic character. The alloy with x = 0 follows Slater-Pauling (S-P) rule with M{sub s} of 5.99μ{sub B}. However, M{sub s} for the alloy with x = 1.00 was found to be 5.42μ{sub B}, which is lower than the value of 6.0μ{sub B} predicted by S-P rule. Since atomic disorder is known to affect the M{sub s} and electronic structure of these alloys, ab initio calculations were carried out to explain the deviation in observed M{sub s} from S-P rule prediction and the half-metallic character of the alloys. Ab initio calculations reveal that alloys with L2{sub 1} structure have M{sub s} value as predicted by S-P rule. However, introduction of 12.5% DO{sub 3} disorder, which occurs due to swapping of Co and Fe atoms in the unit cell, decreases M{sub s} of alloys with x > 0 from the S-P prediction to values obtained experimentally. The results analyzed from the view point of electronic structure of the alloys in different ordered states bring out the influence of disorder on the observed magnetic properties of these technologically important alloys.« less

Synthesis, structure, spectroscopic investigations, and computational studies of optically pure β-ketoamide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mtat, D.; Touati, R.; Guerfel, T., E-mail: taha-guerfel@yahoo.fr

2016-12-15

Chemical preparation, X-ray single crystal diffraction, IR and NMR spectroscopic investigations of a novel nonlinear optical organic compound (C{sub 17}H{sub 22}NO{sub 2}Cl) are described. The compound crystallizes in the orthorhombic system with the non-centrosymmetric sp. gr. P2{sub 1}2{sub 1}2{sub 1}. In the crystal structure, molecules are interconnected by N–H…O hydrogen bonds forming infinite chains along a axis. The Hirshfeld surface and associated fingerprint plots of the compound are presented to explore the nature of intermolecular interactions and their relative contributions in building the solid-state architecture. The molecular HOMO–LUMO compositions and their respective energy gaps are also drawn to explain themore » activity of the compound. The first hyperpolarizability β{sub tot} of the title compound is determined using DFT calculations. The optical properties are also investigated by UV–Vis absorption spectrum.« less

Expression, purification and preliminary X-ray diffraction studies of the transcriptional factor PyrR from Bacillus halodurans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arreola, Rodrigo; Vega-Miranda, Anita; Gómez-Puyou, Armando

The gene-regulation factor PyrR from B. halodurans has been crystallized in two crystal forms. Preliminary crystallographic analysis showed that the protein forms tetramers in both space groups. The PyrR transcriptional regulator is widely distributed in bacteria. This RNA-binding protein is involved in the control of genes involved in pyrimidine biosynthesis, in which uridyl and guanyl nucleotides function as effectors. Here, the crystallization and preliminary X-ray diffraction analysis of two crystal forms of Bacillus halodurans PyrR are reported. One of the forms belongs to the monoclinic space group P2{sub 1} with unit-cell parameters a = 59.7, b = 87.4, c =more » 72.1 Å, β = 104.4°, while the other form belongs to the orthorhombic space group P22{sub 1}2{sub 1} with unit-cell parameters a = 72.7, b = 95.9, c = 177.1 Å. Preliminary X-ray diffraction data analysis and molecular-replacement solution revealed the presence of four and six monomers per asymmetric unit; a crystallographic tetramer is formed in both forms.« less

High-pressure synthesis and crystal structures of the strontium oxogallates Sr{sub 2}Ga{sub 2}O{sub 5} and Sr{sub 5}Ga{sub 6}O{sub 14}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kahlenberg, Volker, E-mail: volker.kahlenberg@uibk.ac.at; Goettgens, Valerie; Mair, Philipp

2015-08-15

High-pressure synthesis experiments in a piston–cylinder apparatus at 1.5 GPa/3.0 GPa and 1000 °C resulted in the formation of single-crystals of Sr{sub 2}Ga{sub 2}O{sub 5} and Sr{sub 5}Ga{sub 6}O{sub 14}, respectively. The structures of both compounds have been solved from single-crystal diffraction data sets using direct methods. The first compound is orthorhombic with space group type Pbca (a=10.0021(4) Å, b=9.601(4) Å, c=10.6700(4) Å, V=1024.6(4) Å{sup 3}, M{sub r}=394.68 u, Z=8, D{sub x}=5.12 g/cm{sup 3}) and belongs to the group of single layer gallates. Individual sheets are parallel to (0 0 1) and can be built from the condensation of unbranchedmore » vierer single chains running along [0 1 0]. The layers are characterized by the presence of four- and strongly elliptical eight-membered rings of corner connected tetrahedra in UUDD and UUUUDDDD conformation. Strontium atoms are sandwiched between the tetrahedral layers for charge compensation and are coordinated by six and seven oxygen ligands, respectively. Sr{sub 2}Ga{sub 2}O{sub 5} is isotypic with several other double sulfides and selenides. To the best of our knowledge, it is the first example of an oxide with this structure type. From a structural point of view, Sr{sub 5}Ga{sub 6}O{sub 14} is a phyllogallate as well. The crystal structure adopts the monoclinic space group P2{sub 1}/c (a=8.1426(3) Å, b=8.1803(3) Å, c=10.8755(4) Å, β=91.970(4)° V=723.98(5) Å{sup 3}, M{sub r}=1080.42 u, Z=2, D{sub x}=4.96 g/cm{sup 3}). Individual sheets extend along (0 0 1). Basic building units are unbranched dreier single chains parallel to [1 0 0]. The layers contain tertiary (Q{sup 3}) und quaternary (Q{sup 4}) connected [GaO{sub 4}]-tetrahedra in the ratio 2:1 resulting in a Ga:O ratio of 3:7 and the formation of exclusively five-membered rings. Linkage between adjacent tetrahedral sheets is provided by three symmetrically independent strontium ions which are surrounded by six to eight oxygen atoms. The layers in Sr{sub 5}Ga{sub 6}O{sub 14} are similar to those observed in the melilite structure-type. Crystallochemical relationships between the present phases and other known compounds are discussed in detail. - Graphical abstract: A single tetrahedral layer and the location of the Sr-cations directly above the sheet in high-pressure Sr{sub 5}Ga{sub 6}O{sub 14}. - Highlights: • We report the crystal structures of two new strontium oxogallates with composition Sr{sub 2}Ga{sub 2}O{sub 5} and Sr{sub 5}Ga{sub 6}O{sub 14.} • Both phases have been obtained in the course of high-pressure piston–cylinder experiments performed at 1.5 and 3.0 GPa. • The crystallochemical characteristics and similarities with known structure types are discussed in detail.« less

Synthesis, structure, and electronic structure of CsAgGa{sub 2}Se{sub 4}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mei Dajiang; Yin Wenlong; Feng Kai

2012-02-15

The new metal chalcogenide CsAgGa{sub 2}Se{sub 4} has been synthesized by means of the reactive flux method. It crystallizes in the space group P2{sub 1}/c of the monoclinic system with cell dimensions of a=11.225(2) A, b=7.9443(16) A, c=21.303(4) A, {beta}=103.10(3), V=1850.3(6), and Z=8. The structure contains two-dimensional {sub {infinity}}{sup 2}[AgGa{sub 2}Se{sub 4}]{sup -} layers separated by Cs{sup +} cations. The {sub {infinity}}{sup 2}[AgGa{sub 2}Se{sub 4}]{sup -} superlayer possesses a novel chain-sublayer-chain structure: a {sub {infinity}}{sup 2}[Ag{sub 2}GaSe{sub 6}]{sup 7-} sublayer, composed of {sub {infinity}}{sup 1}[AgGaSe{sub 4}]{sup 4-} chains that are further connected by Ag{sup +} ions, is sandwiched by parallelmore » {sub {infinity}}{sup 1}[Ga{sub 3}Se{sub 8}]{sup 7-} chains to generate the {sub {infinity}}{sup 2}[AgGa{sub 2}Se{sub 4}]{sup -} superlayer. From a band structure calculation, the orbitals of all atoms have contributions to the bottoms of conduction bands, but the band gap is mainly determined by the 4s, 4p orbitals of Ga and Se. - Graphical Abstract: CsAgGa{sub 2}Se{sub 4} contains two-dimensional {sub {infinity}}{sup 2}[AgGa{sub 2}Se{sub 4}]{sup -} layers with a novel chain-sublayer-chain structure. Highlights: Black-Right-Pointing-Pointer New chalcogenide CsAgGa{sub 2}Se{sub 4} has been synthesized. Black-Right-Pointing-Pointer It possesses a new structure type with {sub {infinity}}{sup 2}[AgGa{sub 2}Se{sub 4}]{sup -} layers separated by Cs{sup +} cations. Black-Right-Pointing-Pointer {sub {infinity}}{sup 2}[AgGa{sub 2}Se{sub 4}]{sup -} consists of a {sub {infinity}}{sup 2}[Ag{sub 2}GaSe{sub 6}]{sup 7-} sublayer sandwiched by {sub {infinity}}{sup 1}[Ga{sub 3}Se{sub 8}]{sup 7-} chains. Black-Right-Pointing-Pointer Band gap of CsAgGa{sub 2}Se{sub 4} is mainly determined by the 4s, 4p orbitals of Ga and Se.« less

Layered-structural monoclinic–orthorhombic perovskite La{sub 2}Ti{sub 2}O{sub 7} to orthorhombic LaTiO{sub 3} phase transition and their microstructure characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herrera, G., E-mail: manuel.herrera@enp.unam.mx; Departamento de Química Inorgánica, Universidad de Valencia, 46100 Burjasot, Valencia; Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, 04510 México D. F.

2014-03-01

The layered-structural ceramics, such as lanthanum titanate (La{sub 2}Ti{sub 2}O{sub 7}), have been known for their good temperature and low dielectric loss at microwave frequencies that make them good candidate materials for high frequency applications. However, few studies have been conducted on the synthesis optimization by sol gel reaction, in particular by acrylamide polymerization route. The interest in La{sub 2}Ti{sub 2}O{sub 7} ceramic has been greatly increased recently due to the effect of oriented grains. This anisotropy of the microstructure leads to anisotropy in dielectric, electrical and mechanical properties. In this study, grain oriented lanthanum titanate was produced by themore » sol–gel acrylamide polymerization route. The characterizations of the samples were achieved by thermal analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM). X-ray diffraction indicates that the formation of monoclinic perovskite La{sub 2}Ti{sub 2}O{sub 7} nanocrystals is a necessary first step to obtain orthorhombic LaTiO{sub 3} nanocomposites (with space group Pbnm). In this work we identified that the monoclinic perovskite La{sub 2}Ti{sub 2}O{sub 7} with space group P2{sub 1} transforms its structure into one with the orthorhombic space group Cmc2{sub 1} at approximately 1073 K. The microstructure associated consisted of flaky monoclinic La{sub 2}Ti{sub 2}O{sub 7} nanocomposites in comparison with round-shaped LaTiO{sub 3} nanocomposites. - Highlights: • The flaky-like La{sub 2}Ti{sub 2}O{sub 7} compound was synthesized by sol–gel acrylamide route. • Simultaneous monitoring of the DTA and XRD with temperature was performed. • Phase transformation characterization of La{sub 2}Ti{sub 2}O{sub 7} has been carried out. • The variation of the La{sub 2}Ti{sub 2}O{sub 7} and LaTiO{sub 3} grain morphology has been compared.« less

Alkali metals in beryl and their role in the formation of derivative structural motifs: Comparative crystal chemistry of vorobyevite and pezzottaite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yakubovich, O. V., E-mail: yakubol@geol.msu.ru; Pekov, I. V.; Steele, I. M.

2009-05-15

The crystal structures of high-alkali beryl, i.e., vorobyevite Cs{sub 0.08}Na{sub 0.42}(H{sub 2}O){sub 0.18+y} x [Al{sub 2}(Be{sub 2.35}Li{sub 0.65})Si{sub 6}O{sub 18}], (a = 9.2102(14) A, c = 9.2179(14) A, space group P6/mcc, Z = 2, {rho}{sub calcd}= 2.74 g/cm{sup 3}) and pezzottaite Cs{sub 0.75}Na{sub 0.23}(H{sub 2}O){sub 0.24}[Al{sub 2}Be{sub 2}Li(Si{sub 6}O{sub 18})] (a = 15.955(3) A, c = 27.810(8) A, space group, R3-barc, Z = 18, {rho}{sub calcd}= 3.13 g/cm{sup 3}), are determined at a temperature of 100 K. It is confirmed that, at a high lithium content in minerals of the beryl group, lithium is selectively incorporated into Be tetrahedra. Themore » positive charge deficit due to the replacement of Be{sup 2+} cations by Li{sup +} cations is compensated by incorporating large alkali cations into the 'zeolite' channel. It is shown that, when the lithium content becomes close to unity per the corresponding formula, the Li and Be atoms are ordered and the rhombohedral structure of pezzottaite is formed. It is proposed to retain the historical name vorobyevite for the lithium- and cesium-containing variety of beryl with a disordered distribution of Be and Li atoms.« less

Spectral temperatures of {Delta}{sup 0}(1232) resonances produced in p{sup 12}C and d{sup 12}C collisions at 4.2 GeV/c per nucleon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Imran; Olimov, Kh. K., E-mail: olimov@comsats.edu.pk

The reconstructed experimental transverse momentum (p{sub t}) distributions of {Delta}{sup 0}(1232) resonances produced in p{sup 12}C and d{sup 12}C collisions at 4.2 A GeV/c and the corresponding spectra calculated using Modified FRITIOF model were analyzed in the framework of Hagedorn Thermodynamic Model. The spectral temperatures of {Delta}{sup 0}(1232) resonances were extracted from fitting their p{sub t} spectra with one-temperature Hagedorn function. The extracted spectral temperatures of {Delta}{sup 0}(1232) were compared with the corresponding temperatures of {pi}{sup -} mesons in p{sup 12}C and d{sup 12}C collisions at 4.2 A GeV/c obtained similarly from fitting the p{sub t} spectra of {pi}{sup -}more » by one-temperature Hagedorn function. The spectral temperatures of {Delta}{sup 0}(1232) resonances agreed within uncertainties with the corresponding temperatures of {pi}{sup -} mesons produced in p{sup 12}C and d{sup 12}C collisions at 4.2 A GeV/c.« less

Electron impact excitation of the low-lying 3s[3/2]{sub 1} and 3s{sup ′}[1/2]{sub 1} levels in neon for incident energies between 20 and 300 eV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoshino, M., E-mail: masami-h@sophia.ac.jp; Murai, H.; Kato, H.

2013-11-14

Absolute differential cross sections (DCSs) for electron impact of the two lower-lying 3s[3/2]{sub 1} ({sup 3}P{sub 0}) and 3s{sup ′}[1/2]{sub 1} ({sup 1}P{sub 1}) electronic states in neon (Ne) have been determined for eight incident electron energies in the range 20–300 eV. Comparisons between our results and previous measurements and calculations, where possible, are provided with best agreement being found with the recent large-scale B-spline R-matrix computations [O. Zatsarinny and K. Bartschat, Phys. Rev. A 86, 022717 (2012)]. Based on these DCSs at 100, 200, and 300 eV, a generalised oscillator strength analysis enabled us to determine estimates for themore » optical oscillator strengths of the 3s[3/2]{sub 1} and 3s{sup ′}[1/2]{sub 1} levels. In this case, excellent agreement was found with a range of independent experiments and calculations, giving us some confidence in the validity of our measurement and analysis procedures. Integral cross sections, derived from the present DCSs, were presented graphically and discussed elsewhere [M. Hoshino, H. Murai, H. Kato, Y. Itikawa, M. J. Brunger, and H. Tanaka, Chem. Phys. Lett. 585, 33 (2013)], but are tabulated here for completeness.« less

Epidermal growth factor (EGF)-stimulated inositol phosphate formation in hepatocytes is abolished by pertussis toxin and phorbol esters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, R.M.; Garrison, J.C.

1987-05-01

The EGF-stimulated rise in intracellular Ca/sup 2 +/ (Ca/sup 2 +/)/sub i/ and Ca/sup 2 +/-dependent protein phosphorylation events in isolated hepatocytes are blocked by pertussis toxin and phorbol ester pretreatment. The present study characterized the EGF-stimulated formation of inositol 1,4,5-trisphosphate (Ins(1,4,5)P/sub 3/) and inositol 1,3,4-trisphosphate (Ins(1,3,4)P/sub 3/) in hepatocytes using HPLC methodology to separate the InsP/sub 3/ isomers. Both 66 nM EGF and 10 nM angiotensin II (ANG II) caused a rapid increase in the Ins(1,4,5)P/sub 3/ isomer although EGF-stimulated formation was smaller. At a concentration of ANG II (0.1 nM) which gave an equivalent rise in (Ca/sup 2more » +/)/sub i/ as 66 nM EGF, the kinetics and magnitude of Ins(1,4,5)P/sub 3/ formation were similar. EGF or ANG II-stimulated formation of the Ins(1,3,4)P/sub 3/ isomer was more gradual and increased beyond the level of Ins(1,4,5)P/sub 3/ after 60 sec. The initial EGF and ANG II-stimulated increase in both InsP/sub 3/ isomers was not affected by removing external Ca/sup 2 +/ with a 10-fold excess of EGTA. Pretreatment of rats with pertussis toxin for 72 hrs blocked the ability of EGF to increase Ins(1,4,5)P/sub 3/ but did not affect the increase due to ANG II. Three main pretreatment of cells with 1 ..mu..g/ml phorbol 12-myristate-13-acetate (PMA) also inhibited the EGF-stimulated Ins(1,4,5)P/sub 3/ formation. PMA slightly attenuated Ins(1,4,5)P/sub 3/ formation stimulated by 0.1 nM ANG II but not enough to affect the Ca/sup 2 +/ signal. These data suggest that the signal transduction system used by EGF receptors to increase Ins (1,4,5)P/sub 3/ in hepatocytes is somehow different from that used by ANG II receptors.« less

Crystal structures of the free and inhibited forms of plasmepsin I (PMI) from Plasmodium falciparum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhaumik, Prasenjit; Horimoto, Yasumi; Xiao, Huogen

2011-09-06

Plasmepsin I (PMI) is one of the four vacuolar pepsin-like proteases responsible for hemoglobin degradation by the malarial parasite Plasmodium falciparum, and the only one with no crystal structure reported to date. Due to substantial functional redundancy of these enzymes, lack of inhibition of even a single plasmepsin can defeat efforts in creating effective antiparasitic agents. We have now solved crystal structures of the recombinant PMI as apoenzyme and in complex with the potent peptidic inhibitor, KNI-10006, at the resolution of 2.4 and 3.1 {angstrom}, respectively. The apoenzyme crystallized in the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1} with twomore » molecules in the asymmetric unit and the structure has been refined to the final R-factor of 20.7%. The KNI-10006 bound enzyme crystallized in the tetragonal space group P4{sub 3} with four molecules in the asymmetric unit and the structure has been refined to the final R-factor of 21.1%. In the PMI-KNI-10006 complex, the inhibitors were bound identically to all four enzyme molecules, with the opposite directionality of the main chain of KNI-10006 relative to the direction of the enzyme substrates. Such a mode of binding of inhibitors containing an allophenylnorstatine-dimethylthioproline insert in the P1-P1' positions, previously reported in a complex with PMIV, demonstrates the importance of satisfying the requirements for the proper positioning of the functional groups in the mechanism-based inhibitors towards the catalytic machinery of aspartic proteases, as opposed to binding driven solely by the specificity of the individual enzymes. A comparison of the structure of the PMI-KNI-10006 complex with the structures of other vacuolar plasmepsins identified the important differences between them and may help in the design of specific inhibitors targeting the individual enzymes.« less

Nucleon Resonance Structure from Exclusive Meson Electroproduction with CLAS and CLAS12

DOE Office of Scientific and Technical Information (OSTI.GOV)

Philip L. Cole, Volker D. Burkert, Ralf W. Gothe, Victor I. Mokeev

2012-12-01

The CLAS detector at Jefferson Lab is a unique instrument, which has provided the lion's share of the world's data on meson photo- and electroproduction in the resonance excitation region. The electroexcitation amplitudes for the low-lying resonances P{sub 33} (1232), P{sub 11} (1440), D{sub 13} (1520), and S {sub 11} (1535) were determined over a wide range of Q{sub 2} < 5.0 GeV{sub 2} in a comprehensive analysis of exclusive single-meson ( {pi}{sup +} n, {pi}{sup 0} p) reactions in the electroproduction off protons. Further, we were able to precisely measure {pi}{sup +}{pi}{sup -}p electroproduction differential cross sections provided bymore » the nearly full kinematic coverage of the CLAS detector. And, for the first time, the electrocouplings of the P{sub 11} (1440), D{sub 13} (1520) excited states are determined from the exclusive-{pi}{sup +}{pi}{sup -}p reaction. Consistent results on the electrocouplings from two-independent analyses (single- and double-pion electroproduction) have provided compelling evidence for the reliable extraction of the N* electrocouplings. And preliminary results on the electrocouplings of the S{sub 31} (1620), S{sub 11} (1650), D{sub 33} (1700), and P{sub 13} (1720) states, which decay preferentially to the N{pi} {pi} final states, have recently become available. Theoretical analyses of these results have revealed that there are two major contributions to the resonance structure: a) an internal quark core and b) an external meson-baryon cloud. These CLAS results have had considerable impact on QCD-based studies on N* structure and in the search for manifestations of the dynamical masses of the dressed quarks. Future CLAS12 N* structure studies at high photon virtualities will considerably extend our capabilities in exploring the nature of confinement in baryons.« less

Simultaneous presence of (Si{sub 3}O{sub 10}){sup 8−} and (Si{sub 2}O{sub 7}){sup 6−} groups in new synthetic mixed sorosilicates: BaY{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}) and isotypic compounds, studied by single-crystal X-ray diffraction, Raman spectroscopy and DFT calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wierzbicka-Wieczorek, Maria, E-mail: maria.wierzbicka-wieczorek@uni-jena.de; Többens, Daniel M.; Kolitsch, Uwe

2013-11-15

Three new, isotypic silicate compounds, BaY{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}), SrYb{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}) and SrSc{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}), were synthesized using high-temperature flux growth techniques, and their crystal structures were solved from single-crystal X-ray intensity data: monoclinic, P2{sub 1}/m, with a=5.532(1)/5.469(1)/5.278(1), b=19.734(4)/19.447(4)/19.221(4), c=6.868(1)/6.785(1)/6.562(1) Å, β=106.53(3)/106.20(3)/106.50(3)°, V=718.8(2)/693.0(2)/638.3(2) Å{sup 3}, R(F)=0.0225/0.0204/0.0270, respectively. The topology of the novel structure type contains isolated horseshoe-shaped Si{sub 3}O{sub 10} groups (Si–Si–Si=93.15–95.98°), Si{sub 2}O{sub 7} groups (Si–O{sub bridge}–Si=180°, symmetry-restricted) and edge-sharing M(1)O{sub 6} and M(2)O{sub 6} octahedra. Single-crystal Raman spectra of the title compounds were measured and compared with Raman spectroscopicmore » data of chemically and topologically related disilicates and trisilicates, including BaY{sub 2}(Si{sub 3}O{sub 10}) and SrY{sub 2}(Si{sub 3}O{sub 10}). The band assignments are supported by additional theoretical calculation of Raman vibrations by DFT methods. - Graphical abstract: View of BaY{sub 4}(Si{sub 2}O{sub 7})(Si{sub 3}O{sub 10}) along [100], showing zigzag chains and the tri- and disilicate groups. The unit cell is outlined. Display Omitted - Highlights: • We report a novel interesting crystal structure type for mixed sorosilicates containing Y, Yb, and Sc. • Synthesis of such mixed sorosilicates is possible by a high-temperature flux-growth technique. • Calculation of Raman vibrations by advanced DFT methods allows a considerably improved interpretation of measured Raman spectra.« less

AGE AND DISTANCE FOR THE OLD OPEN CLUSTER NGC 188 FROM THE ECLIPSING BINARY MEMBER V 12

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meibom, Soeren; Mathieu, Robert D.; Grundahl, Frank

2009-06-15

We present time series radial velocity, and photometric observations of a solar-type double-lined eclipsing binary star (V 12) in the old open cluster NGC 188. We use these data to determine the spectroscopic orbit and the photometric elements for V 12. From our analysis, we determine accurate masses (M{sub p} = 1.103 {+-} 0.007 M {sub sun}, M{sub s} = 1.081 {+-} 0.007 M {sub sun}) and radii (R{sub p} = 1.424 {+-} 0.019 R {sub sun}, R{sub s} = 1.373 {+-} 0.019 R {sub sun}) for the primary (p) and secondary (s) binary components. We adopt a reddening ofmore » E {sub B-V} = 0.087 for NGC 188, and derive component effective temperatures of 5900 {+-} 100 K and 5875 {+-} 100 K, respectively, for the primary and secondary stars. From their absolute dimensions, the two components of V 12 yield identical distance moduli of V {sub 0} - M{sub V} = 11fm24 {+-} 0fm09, corresponding to 1770 {+-} 75 pc. Both stars are near the end of their main-sequence evolutionary phase, and are located at the cluster turnoff in the color-magnitude diagram. We determine an age of 6.2 {+-} 0.2 Gyr for V 12 and NGC 188, from a comparison with theoretical isochrones in the mass-radius diagram. This age is independent of distance, reddening, and color-temperature transformations. We use isochrones from Victoria-Regina (VRSS) and Yonsei-Yale (Y {sup 2}) with [Fe/H] = -0.1 and [Fe/H] = 0.0. From the solar metallicity isochrones, an age of 6.4 Gyr provides the best fit to the binary components for both sets of models. For the isochrones with [Fe/H] = -0.1, ages of 6.0 Gyr and 5.9 Gyr provide the best fits for the (VRSS) and (Y {sup 2}) models, respectively. We use the distance and age estimates for V 12, together with best estimates for the metallicity and reddening of NGC 188, to investigate the locations of the corresponding VRSS and Y {sup 2} isochrones relative to cluster members in the color-magnitude diagram. Plausible changes in the model metallicity and distance to better match the isochrones to the cluster sequences, result in a range of ages for NGC 188 that is more than 3 times that resulting from our analysis of V 12.« less

Mn{sub 0.95}I{sub 0.02}[PO{sub 3}(OH)] · 2H{sub 2}O phosphate–iodate, an inorganic analogue of phosphonates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belokoneva, E. L., E-mail: elbel@geol.msu.ru; Dimitrova, O. V.; Volkov, A. S.

2015-09-15

The new Mn{sub 0.95}I{sub 0.02}[PO{sub 3}(OH)] · 2H{sub 2}O phosphate–iodate (space group Pnam = Pnma, D{sub 2h}{sup 16}) is obtained under hydrothermal conditions. The crystal structure is determined without preliminary knowledge of the chemical formula. The structure consists of layers of MnO{sub 6} octahedra connected with PO{sub 4} tetrahedra. Water molecules are located between the layers. [IO3]{sup –} groups having a typical umbrella-like coordination are statistically implanted in layers of MnO{sub 6} octahedra at a distance of 1.2 Å from Mn atoms. Their content in the crystal is minor. The structures of the phosphate–iodate coincides with the structures of phosphonatesmore » with consideration for the replacement of one (OH) vertex of the PO{sub 4} tetrahedron by the organic methyl radical CH{sub 3}. In the structures of phosphonates and earlier studied phosphates, identical layers are distinguished and the cause of the existence of two MDO varieties is established based on the analysis within the OD theory. Possible hybrid structures derived from the prototypes under consideration are predicted.« less

Confinement induced binding of noble gas atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khatua, Munmun; Pan, Sudip; Chattaraj, Pratim K., E-mail: pkc@chem.iitkgp.ernet.in

2014-04-28

The stability of Ng{sub n}@B{sub 12}N{sub 12} and Ng{sub n}@B{sub 16}N{sub 16} systems is assessed through a density functional study and ab initio simulation. Although they are found to be thermodynamically unstable with respect to the dissociation of individual Ng atoms and parent cages, ab initio simulation reveals that except Ne{sub 2}@B{sub 12}N{sub 12} they are kinetically stable to retain their structures intact throughout the simulation time (500 fs) at 298 K. The Ne{sub 2}@B{sub 12}N{sub 12} cage dissociates and the Ne atoms get separated as the simulation proceeds at this temperature but at a lower temperature (77 K) itmore » is also found to be kinetically stable. He-He unit undergoes translation, rotation and vibration inside the cavity of B{sub 12}N{sub 12} and B{sub 16}N{sub 16} cages. Electron density analysis shows that the He-He interaction in He{sub 2}@B{sub 16}N{sub 16} is of closed-shell type whereas for the same in He{sub 2}@B{sub 12}N{sub 12} there may have some degree of covalent character. In few cases, especially for the heavier Ng atoms, the Ng-N/B bonds are also found to have some degree of covalent character. But the Wiberg bond indices show zero bond order in He-He bond and very low bond order in cases of Ng-N/B bonds. The energy decomposition analysis further shows that the ΔE{sub orb} term contributes 40.9% and 37.3% towards the total attraction in the He{sub 2} dimers having the same distances as in He{sub 2}@B{sub 12}N{sub 12} and He{sub 2}@B{sub 16}N{sub 16}, respectively. Therefore, confinement causes some type of orbital interaction between two He atoms, which akins to some degree of covalent character.« less

Purification, crystallization and preliminary X-ray diffraction of the N-terminal calmodulin-like domain of the human mitochondrial ATP-Mg/P{sub i} carrier SCaMC1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Qin, E-mail: yang@crystal.harvard.edu; Brüschweiler, Sven; Chou, James J., E-mail: yang@crystal.harvard.edu

2013-12-24

The N-terminal calmodulin-like domain of the human mitochondrial ATP-Mg/P{sub i} carrier SCaMC1 was crystallized in the presence of Ca{sup 2+}. X-ray diffraction data were collected to 2.9 Å resolution from crystals which belonged to space group P6{sub 2}22.

Synthesis, structure and photoluminescence properties of amine-templated open-framework bismuth sulfates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marri, Subba R.; Behera, J.N., E-mail: jnbehera@niser.ac.in

2014-02-15

Two organically-templated bismuth sulfates of the compositions, [C{sub 6}N{sub 2}H{sub 14}] [Bi(SO{sub 4}){sub 2}(NO{sub 3})], (1) and [C{sub 4}N{sub 2}H{sub 12}]{sub 4}[Bi{sub 4}(SO{sub 4}){sub 10}(H{sub 2}O){sub 4}], (2), with open architecture have been synthesized and their structures determined by single crystal X-ray diffraction. 1 has a corrugated layered structure with 8-membered aperture wherein the SO{sub 4} tetrahedra and the BiO{sub 8} polyhedra join together to form (4, 4) net sheets of the metal centers while 2 has a three-dimensional structure possessing 8- and 12-membered channels. Both the compounds show good fluorescence properties exhibiting blue luminescence. Time-resolved fluorescence behavior of 1more » and 2 shows mean fluorescence life time of 0.9 and 1.0 ns, respectively. - Graphical abstract: Two open-framework bismuth sulfates with the layered and three-dimensional structures have been synthesized and characterized. Both the compounds show good fluorescence properties exhibiting blue luminescence. Display Omitted - Highlights: • Two organically-templated bismuth sulfates with open architecture have been synthesized and characterized. • One has a corrugated layered structure while the other one has a three-dimensional structure possessing channels. • They are novel in that open-framework three-dimensional main group metal sulfates are first to be reported. • They show good fluorescence properties exhibiting blue luminescence.« less

Thermochemical cycles for the production of hydrogen

DOEpatents

Steinberg, M.; Dang, V.D.

Two-step processes for the preparation of hydrogen are described: CrCl/sub 3/(g) ..-->.. CrCl/sub 2/(g) + 1/2Cl/sub 2/(g) and CrCl/sub 2/(s) + HCl(g) reversible CrCl/sub 3/(s) + 1/2H/sub 2/(g); UCl/sub 4/(g) ..-->.. UCl/sub 3/(g) + 1/2Cl/sub 2/(g) and UCl/sub 3/(s) + HCl(g) ..-->.. UCl/sub 4/(s) + 1/2H/sub 2/(g); and CaSO/sub 4/(s) ..-->.. CaO(s) + SO/sub 2/(g) + 1/2O/sub 2/(g) and CaO(s) + SO/sub 2/(g) + H/sub 2/O(l) ..-->.. CaSO/sub 4/(s) + H/sub 2/(g). The high temperature available from solar collectors, high temperature gas reactors or fusion reactors is utilized in the first step in which the reaction is endothermic. The efficiency is at least 60% and with process heat recovery, the efficiency may be increased up to 74.4%. An apparatus fr carrying out the process in conjunction with a fusion reactor, is described.

Low-temperature high-density magneto-optical trapping of potassium using the open 4S{yields}5P transition at 405 nm

DOE Office of Scientific and Technical Information (OSTI.GOV)

McKay, D. C.; Jervis, D.; Fine, D. J.

2011-12-15

We report the laser cooling and trapping of neutral potassium on an open transition. Fermionic {sup 40}K is captured using a magneto-optical trap (MOT) on the closed 4S{sub 1/2}{yields}4P{sub 3/2} transition at 767 nm and then transferred, with high efficiency, to a MOT on the open 4S{sub 1/2}{yields}5P{sub 3/2} transition at 405 nm. Because the 5P{sub 3/2} state has a smaller linewidth than the 4P{sub 3/2} state, the Doppler limit is reduced from 145 {mu}K to 24 {mu}K, and we observe temperatures as low as 63(6) {mu}K. The density of trapped atoms also increases, due to reduced temperature and reducedmore » expulsive light forces. We measure a two-body loss coefficient of {beta}=1.4(1)x10{sup -10} cm{sup 3}/s near saturation intensity, and estimate an upper bound of 8x10{sup -18} cm{sup 2} for the ionization cross section of the 5P state at 405 nm. The combined temperature and density improvement in the 405 nm MOT is a twenty-fold increase in phase-space density over our 767 nm MOT, showing enhanced precooling for quantum gas experiments. A qualitatively similar enhancement is observed in a 405 nm MOT of bosonic {sup 41}K.« less

Expression, Purification, Crystallization of Two Major Envelope Proteins from White Spot Syndrome Virus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang,X.; Hew, C.

2007-01-01

White spot syndrome virus (WSSV) is a major virulent pathogen known to infect penaeid shrimp and other crustaceans. VP26 and VP28, two major envelope proteins from WSSV, have been identified and overexpressed in Escherichia coli. In order to facilitate purification and crystallization, predicted N-terminal transmembrane regions of approximately 35 amino acids have been truncated from both VP26 and VP28. Truncated VP26 and VP28 and their corresponding SeMet-labelled proteins were purified and the SeMet proteins were crystallized by the hanging-drop vapor-diffusion method. Crystals of SeMet-labelled VP26 were obtained using a reservoir consisting of 0.1 M citric acid pH 3.5, 3.0 Mmore » sodium chloride and 1%(w/v) polyethylene glycol 3350, whereas SeMet VP28 was crystallized using a reservoir solution consisting of 25% polyethylene glycol 8000, 0.2 M calcium acetate, 0.1 M Na HEPES pH 7.5 and 1.5%(w/v) 1,2,3-heptanetriol. Crystals of SeMet-labelled VP26 diffract to 2.2 {angstrom} resolution and belong to space group R32, with unit-cell parameters a = b = 73.92, c = 199.31 {angstrom}. SeMet-labelled VP28 crystallizes in space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 105.33, b = 106.71, c = 200.37 {angstrom}, and diffracts to 2.0 {angstrom} resolution.« less

Which Photodiode to Use: A Comparison of CMOS-Compatible Structures

PubMed Central

Murari, Kartikeya; Etienne-Cummings, Ralph; Thakor, Nitish; Cauwenberghs, Gert

2010-01-01

While great advances have been made in optimizing fabrication process technologies for solid state image sensors, the need remains to be able to fabricate high quality photosensors in standard CMOS processes. The quality metrics depend on both the pixel architecture and the photosensitive structure. This paper presents a comparison of three photodiode structures in terms of spectral sensitivity, noise and dark current. The three structures are n+/p-sub, n-well/p-sub and p+/n-well/p-sub. All structures were fabricated in a 0.5 μm 3-metal, 2-poly, n-well process and shared the same pixel and readout architectures. Two pixel structures were fabricated—the standard three transistor active pixel sensor, where the output depends on the photodiode capacitance, and one incorporating an in-pixel capacitive transimpedance amplifier where the output is dependent only on a designed feedback capacitor. The n-well/p-sub diode performed best in terms of sensitivity (an improvement of 3.5 × and 1.6 × over the n+/p-sub and p+/n-well/p-sub diodes, respectively) and signal-to-noise ratio (1.5 × and 1.2 × improvement over the n+/p-sub and p+/n-well/p-sub diodes, respectively) while the p+/n-well/p-sub diode had the minimum (33% compared to other two structures) dark current for a given sensitivity. PMID:20454596

Which Photodiode to Use: A Comparison of CMOS-Compatible Structures.

PubMed

Murari, Kartikeya; Etienne-Cummings, Ralph; Thakor, Nitish; Cauwenberghs, Gert

2009-07-01

While great advances have been made in optimizing fabrication process technologies for solid state image sensors, the need remains to be able to fabricate high quality photosensors in standard CMOS processes. The quality metrics depend on both the pixel architecture and the photosensitive structure. This paper presents a comparison of three photodiode structures in terms of spectral sensitivity, noise and dark current. The three structures are n(+)/p-sub, n-well/p-sub and p(+)/n-well/p-sub. All structures were fabricated in a 0.5 mum 3-metal, 2-poly, n-well process and shared the same pixel and readout architectures. Two pixel structures were fabricated-the standard three transistor active pixel sensor, where the output depends on the photodiode capacitance, and one incorporating an in-pixel capacitive transimpedance amplifier where the output is dependent only on a designed feedback capacitor. The n-well/p-sub diode performed best in terms of sensitivity (an improvement of 3.5 x and 1.6 x over the n(+)/p-sub and p(+)/n-well/p-sub diodes, respectively) and signal-to-noise ratio (1.5 x and 1.2 x improvement over the n(+)/p-sub and p(+)/n-well/p-sub diodes, respectively) while the p(+)/n-well/p-sub diode had the minimum (33% compared to other two structures) dark current for a given sensitivity.

High grain boundary density Li{sub 4}Ti{sub 5}O{sub 12}/anatase-TiO{sub 2} nanocomposites as anode material for Li-ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stenina, I.A.; Kulova, T.L.; Skundin, A.M.

2016-03-15

Highlights: • Li{sub 4}Ti{sub 5}O{sub 12}/TiO{sub 2} nanocomposites with high grain boundary density were synthesized. • {sup 7}Li NMR and impedance spectroscopy shows high Li-ion mobility in nanocomposites. • The shape of charge/discharge curves changes for nanocomposites. • Influence of particle size on cycling performance of lithium titanates was shown. • Li{sub 4}Ti{sub 5}O{sub 12}/TiO{sub 2} nanocomposite exhibits good cycling performance and rate capability. - Abstract: Li{sub 4}Ti{sub 5}O{sub 12}/TiO{sub 2} nanocomposites are synthesized by a sol-gel method. The size of Li{sub 4}Ti{sub 5}O{sub 12} and TiO{sub 2} particles is of 4–5 and 7–10 nm, respectively. The obtained materials aremore » characterized by XRD, SEM, HRTEM and BET. Ion mobility of the composites and their performance as anode materials for lithium-ion batteries are studied. According to the conductivity and {sup 7}Li NMR data, Li{sup +} mobility is much higher in the Li{sub 4}Ti{sub 5}O{sub 12}/TiO{sub 2} nanocomposites as compared with that in pure Li{sub 4}Ti{sub 5}O{sub 12}. For Li{sub 4}Ti{sub 5}O{sub 12}/TiO{sub 2} nanocomposites, marked changes in the charge–discharge curves are observed; charge–discharge rate and effective capacity at a high cycling rate are shown to increase. During the first cycle, charge capacity of these materials surpasses the theoretical capacity of Li{sub 4}Ti{sub 5}O{sub 12}. However, this parameter decreases sharply with cycling, whereas the discharge capacity remains almost unchanged. This phenomenon is attributed to the solid electrolyte interphase formation due to a partial electrolyte reduction on the Li{sub 4}Ti{sub 5}O{sub 12}/TiO{sub 2} composite surface.« less

Expression, purification, crystallization and initial crystallographic characterization of the p-hydroxybenzoate hydroxylase from Corynebacterium glutamicum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwon, Soo-Young; Kang, Beom Sik; Kim, Ghyung-Hwa

2007-11-01

PHBH from Corynebacterium glutamicum was crystallized using the hanging-drop vapour-diffusion method in the presence of NaH{sub 2}PO{sub 4} and K{sub 2}HPO{sub 4} as precipitants. X-ray diffraction data were collected to a maximum resolution of 2.5 Å on a synchrotron beamline. p-Hydroxybenzoate hydroxylase (PHBH) is an FAD-dependent monooxygenase that catalyzes the hydroxylation of p-hydroxybenzoate (pOHB) to 3,4-dihydroxybenzoate in an NADPH-dependent reaction and plays an important role in the biodegradation of aromatic compounds. PHBH from Corynebacterium glutamicum was crystallized using the hanging-drop vapour-diffusion method in the presence of NaH{sub 2}PO{sub 4} and K{sub 2}HPO{sub 4} as precipitants. X-ray diffraction data were collectedmore » to a maximum resolution of 2.5 Å on a synchrotron beamline. The crystal belongs to the hexagonal space group P6{sub 3}22, with unit-cell parameters a = b = 94.72, c = 359.68 Å, γ = 120°. The asymmetric unit contains two molecules, corresponding to a packing density of 2.65 Å{sup 3} Da{sup −1}. The structure was solved by molecular replacement. Structure refinement is in progress.« less

$eta$ production at high Q^2

DOE Office of Scientific and Technical Information (OSTI.GOV)

M.K. Jones

2012-04-01

The differential cross-sections for the p(e,e'p){eta} reaction have been measured in Hall C at Jefferson Lab at Q{sup 2} = 5.7 and 7.0 (GeV/c){sup 2} for center-of-mass energies from threshold to 1.8 GeV, encompassing the S{sub 11}(1535) resonance, which dominates the reaction. From fits to the data, the S{sub 11}(1535) helicity conserving photo-coupling amplitude, A{sub 1/2}, was extracted.

Crystal structure of centrosymmetric 12-layer sodium-rich eudialyte

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rozenberg, K. A.; Rastsvetaeva, R. K., E-mail: rast@ns.crys.ras.ru; Verin, I. A.

2009-05-15

The structure of a new representative of the eudialyte group with the formula (Na,Sr,K){sub 18}Ca{sub 6}Zr{sub 3}Fe[Si{sub 25}O{sub 72}](OH){sub 2}Cl . H{sub 2}O from the Lovozero massif (Kola Peninsula) was studied by X-ray diffraction. The trigonal unit-cell parameters are a = 14.226 A, c = 30.339 A, sp. gr. R3-barm; the R factor is 0.045 based on 990 reflections. This sample is of interest as a sodium-rich and iron-poor mineral having a rare centrosymmetric structure, in which the M(2) site is occupied predominantly by sodium atoms. The dependence of the formation of centrosymmetric and non-centrosymmetric structures on the composition ofmore » eudialyte-group minerals was analyzed.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xiaohong; Bowman, Joel M., E-mail: jmbowma@emory.edu; Huang, Xinchuan

We report a CCSD(T)/cc-pCV5Z quartic force field (QFF) and a semi-global CCSD(T)-F12b/aug-cc-pVTZ potential energy surface (PES) for singlet, cyclic C{sub 4}. Vibrational fundamentals, combinations, and overtones are obtained using vibrational second-order perturbation theory (VPT2) and the vibrational configuration-interaction (VCI) approach. Agreement is within 10 cm{sup −1} between the VCI calculated fundamentals on the QFF and PES using the MULTIMODE (MM) program, and VPT2 and VCI results agree for the fundamentals. The agreement between VPT2-QFF and MM-QFF results is also good for the C{sub 4} combinations and overtones. The J = 1 and J = 2 rovibrational energies are reported frommore » both VCI (MM) on the PES and VPT2 on the QFF calculations. The spectroscopic constants of {sup 12}C{sub 4} and two C{sub 2v}-symmetry, single {sup 13}C-substituted isotopologues are presented, which may help identification of cyclic C{sub 4} in future experimental analyses or astronomical observations.« less

Prolonged P300 latency in children with the D[sub 2] dopamine receptor A1 allele

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noble, E.P.; Berman, S.M.; Ozkaragoz, T.Z.

1994-04-01

Previous studies have indicated the presence of a hereditary component in the generation of the P300, or P3, a late positive component of the event-related potential. Moreover, the dopaminergic system has been implicated in the P3. In the present study, 98 healthy Caucasian boys, mean age of 12.5 years and of above-average intelligence, were studied. The sample was composed of 32 sons of active alcoholic (SAA) fathers, 36 sons of recovering alcoholic (SRA) fathers, and 30 sons of social drinker (SSD) fathers, with none of them having yet begun to consume alcohol or other drugs. TaqI A D[sub 2] dopaminemore » receptor alleles (A1 and A2) were determined. A significant difference in the frequency of the A1 allele was found among these three groups of boys, with the SAA group having the highest A1 allele frequency (.313), followed by the SRA (.139) and the SSD (.133) groups. The relationship of the A1 and A2 alleles to P3 amplitude and latency was also determined. The results showed no significant difference in P3 amplitude between boys with the A1 and A2 allele. However, P3 latency was significantly longer in the total sample of boys with the A1 allele compared with those carrying the A2 allele. These findings suggest that polymorphism of the D[sub 2] dopamine receptor gene is an important determinant of P3 latency. 84 refs., 2 figs., 3 tabs.« less

A simple relation between the gamma N -> N(1535) helicity amplitudes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilberto Ramalho, Kazuo Tsushima

2011-09-01

It is shown that the helicity amplitudes A{sub 1/2} and S{sub 1/2} in the {gamma}N {yields} N(1535) reaction, can be well related by S{sub 1/2} = {radical}1+{tau}/{radical}2 M{sub S}{sup 2}-M{sup 2}/2M{sub S}Q A{sub 1/2} in the region Q{sup 2} > 2 GeV{sup 2}, where M and M{sub S} are the nucleon and N(1535) masses, q{sup 2} = -Q{sup 2} the four-momentum transfer squared, and {tau} = Q{sup 2}/(M{sub S} + M){sup 2}. This follows from the fact that the Pauli-type transition form factor F*{sub 2} extracted from the experimental data, turns up to show F*{sub 2} {approx_equal} 0 for Q{supmore » 2} > 1.5 GeV{sup 2}. The observed relation is tested by the experimental data and the MAID parametrization. A direct consequence of the relation is that the assumption,|A{sub 1/2}| >> |S{sub 1/2}|, is not valid for high Q{sup 2}. Instead, both amplitudes A{sub 1/2} and S{sub 1/2} have the same Q{sup 2} dependence in the high Q{sup 2} region, aside from that S{sub 1/2} has an extra factor, - 1/{radical} M{sub S}-M/2M{sub s}. The origin of this relation is interpreted in a perspective of a quark model.« less

A Dosimetric Model of Duodenal Toxicity After Stereotactic Body Radiotherapy for Pancreatic Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murphy, James D.; Christman-Skieller, Claudia; Kim, Jeff

2010-12-01

Introduction: Dose escalation for pancreas cancer is limited by the tolerance of adjacent normal tissues, especially with stereotactic body radiotherapy (SBRT). The duodenum is generally considered to be the organ at greatest risk. This study reports on the dosimetric determinants of duodenal toxicity with single-fraction SBRT. Methods and Materials: Seventy-three patients with locally advanced unresectable pancreatic adenocarcinoma received 25 Gy in a single fraction. Dose-volume histogram (DVH) endpoints evaluated include V{sub 5} (volume of duodenum that received 5 Gy), V{sub 10}, V{sub 15}, V{sub 20}, V{sub 25}, and D{sub max} (maximum dose to 1 cm{sup 3}). Normal tissue complication probabilitymore » (NTCP) was evaluated with a Lyman model. Univariate and multivariate analyses were conducted with Kaplan-Meier and Cox regression models. Results: The median time to Grade 2-4 duodenal toxicity was 6.3 months (range, 1.6-11.8 months). The 6- and 12-month actuarial rates of toxicity were 11% and 29%, respectively. V{sub 10}-V{sub 25} and D{sub max} all correlated significantly with duodenal toxicity (p < 0.05). In particular, V{sub 15} {>=} 9.1 cm{sup 3} and V{sub 15} < 9.1 cm{sup 3} yielded duodenal toxicity rates of 52% and 11%, respectively (p = 0.002); V{sub 20} {>=} 3.3 cm{sup 3} and V{sub 20} < 3.3 cm{sup 3} gave toxicity rates of 52% and 11%, respectively (p = 0.002); and D{sub max} {>=} 23 Gy and D{sub max} < 23 Gy gave toxicity rates of 49% and 12%, respectively (p = 0.004). Lyman NTCP model optimization generated the coefficients m = 0.23, n = 0.12, and TD{sub 50} = 24.6 Gy. Only the Lyman NTCP model remained significant in multivariate analysis (p = 0.001). Conclusions: Multiple DVH endpoints and a Lyman NTCP model are strongly predictive of duodenal toxicity after SBRT for pancreatic cancer. These dose constraints will be valuable in future abdominal SBRT studies.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yan; Pan, Cheng-Ling; Xiao, Li-Na

Three new supramolecular compounds based on triethylenediamine and different polyoxometalates [W{sup VI}{sub 3}V{sup V}{sub 3}O{sub 19}H]{l_brace}[Cu(HDABCO)]{sub 2}(H{sub 2}O){r_brace} (1), [P{sub 2}Mo{sup VI}{sub 18}O{sub 62}][HDABCO]{sub 2}[H{sub 2}DABCO]{sub 2}.12 H{sub 2}O (2) and [Mo{sup VI}{sub 7.5}W{sup VI}{sub 0.5}O{sub 27}][Cu(HDABCO)]{sub 2}.2 H{sub 3}O.2 H{sub 2}O (3) (DABCO=triethylenediamine) have been synthesized hydrothermally and characterized by IR, TG, XPS and X-ray diffraction analyses. Crystal structure analyses reveal that compound 1 exhibits a face-centered cubic packing motif, compound 2 displays a supramolecular structure constructed form the 'chains' arranged hexagonally, compound 3 contains [Mo{sub 7.5}W{sub 0.5}O{sub 27}]{sub {infinity}} chain decorated by [Cu(HDABCO)]{sup 2+} cations, which was thenmore » packed into a layer structure. These results show that the same organonitrogen combining with the different POMs will yield different supramolecular networks. -- Graphical abstract: Three new supramolecular compounds based on triethylenediamine and different polyoxometalates have been hydrothermally synthesized and characterized by IR, XPS, TG, elemental analysis and X-ray diffraction analysis.« less

Electronic structure of monodentate-coordinated diphosphine complexes. Photoelectron spectra of Mo(CO)[sub 5](P(CH[sub 3])[sub 2]CH[sub 2]P(CH[sub 3])[sub 2]) and Mo(CO)[sub 5](P(CH[sub 3])[sub 2]CH[sub 2]CH[sub 2]P(CH[sub 3])[sub 2])

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lichtenberger, D.L.; Jatcko, M.E.

1992-02-05

Photoelectron spectroscopy is used to study the electronic structure of molybdenum carbonyl complexes that contain diphosphine ligands bound to the metal through only one of the two phosphorus atoms. Photoelectron spectra are reported for Mo(CO)[sub 5]DMPE and Mo(CO)[sub 5]DMPM and compared to the spectra of Mo(CO)[sub 5]PMe[sub 3] and the corresponding free phosphine and diphosphine ligands (PMe[sub 3] is trimethylphosphine, DMPE is 1,2-bis(dimethylphosphino)ethane, and DMPM is bis(dimethylphosphino)methane). The energy splittings between the d[sup 6] metal-based ionizations of these complexes indicate that the [pi]-back-bonding ability is the same for each of these phosphine ligands and is relatively small, about 25% thatmore » of carbon monoxide. The metal-based ionizations shift only slightly to lower binding energy from the PMe[sub 3] to the DMPE to the DMPM complex due to a slightly increasing negative charge potential at the metal along this series. This would normally be interpreted as slightly increasing [sigma]-donor strength in the order PMe[sub 3] < DMPE < DMPM. However, the difference between the ionization energy of the coordinated lone pair (CLP) of the phosphine and the ionization energy of the lone pair of the free ligand indicates an opposite trend in [sigma]-donor strength with PMe[sub 3] (1.28 eV) > DMPE (1.27 eV) > DMPM (1.23 eV). The shift of the uncoordinated phosphine lone-pair ionization (ULP) of the monocoordinated diphosphine complexes, which is affected primarily by charge potential effects, reveals that the important factor is a transfer of negative charge from the uncoordinated end of the phosphine through the alkyl linkage to the coordinated phosphine. Aside from these subtle details of charge distribution, the primary conclusion is that the diphosphine ligands, DMPE and DMPM, have [sigma]-donor and [pi]-acceptor strengths extremely similar to those of PMe[sub 3].« less

Reactivity of alkaline lignite fly ashes towards CO{sub 2} in water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin Back; Michael Kuehn; Helge Stanjek

2008-06-15

The reaction kinetics between alkaline lignite fly ashes and CO{sub 2} (pCO{sub 2} = 0.01-0.03 MPa) were studied in a laboratory CO{sub 2} flow-through reactor at 25-75{sup o}C. The reaction is characterized by three phases that can be separated according to the predominating buffering systems and the rates of CO{sub 2} uptake. Phase I (pH > 12, < 30 min) is characterized by the dissolution of lime, the onset of calcite precipitation and a maximum uptake, the rate of which seems to be limited by dissolution of CO{sub 2}. Phase II (pH < 10.5, 10-60 min) is dominated by themore » carbonation reaction. CO{sub 2} uptake in phase III (pH < 8.3) is controlled by the dissolution of periclase (MgO) leading to the formation of dissolved magnesium-bicarbonate. Phase I could be significantly extended by increasing the solid-liquid ratios and temperature, respectively. At 75{sup o}C the rate of calcite precipitation was doubled leading to the neutralization of approximately 0.23 kg CO{sub 2} per kg fly ash within 4.5 h, which corresponds to nearly 90% of the total acid neutralizing capacity. 21 refs., 5 figs., 1 tab.« less

Hydrothermal synthesis of zinc(II)-phosphonate coordination polymers with different dimensionality (0D, 2D, 3D) and dimensionality change in the solid phase (0D→3D) induced by temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernández-Zapico, Eva; Montejo-Bernardo, Jose; Fernández-González, Alfonso

2015-05-15

Three new zinc(II) coordination polymers, [Zn(HO{sub 3}PCH{sub 2}CH{sub 2}COO)(C{sub 12}H{sub 8}N{sub 2})(H{sub 2}O)] (1), [Zn{sub 3}(O{sub 3}PCH{sub 2}CH{sub 2}COO){sub 2}(C{sub 12}H{sub 8}N{sub 2})](H{sub 2}O){sub 3.40} (2) and [Zn{sub 5}(HO{sub 3}PCH{sub 2}CH{sub 2}COO){sub 2}(O{sub 3}PCH{sub 2}CH{sub 2}COO){sub 2}(C{sub 12}H{sub 8}N{sub 2}){sub 4}](H{sub 2}O){sub 0.32} (3), with different structural dimensionality (0D, 2D and 3D, respectively) have been prepared by hydrothermal synthesis, and their structures were determined by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic system (P2{sub 1}/c) forming discrete dimeric units bonded through H-bonds, while compounds 2 and 3 crystallize in the triclinic (P−1) and the monoclinic (C2/c) systems, respectively.more » Compound 3, showing three different coordination numbers (4, 5 and 6) for the zinc atoms, has also been obtained by thermal treatment of 1 (probed by high-temperature XRPD experiments). The crystalline features of these compounds, related to the coordination environments for the zinc atoms in each structure, provoke the increase of the relative fluorescence for 2 and 3, compared to the free phenanthroline. Thermal analysis (TG and DSC) and XPS studies have been also carried out for all compounds. - Graphical abstract: Three new coordination compounds of zinc with 2-carboxyethylphosphonic acid (H{sub 2}PPA) and phenanthroline have been obtained by hydrothermal synthesis. The crystalline structure depends on the different coordination environments of the zinc atoms (see two comparative Zn{sub 6}-moieties). The influence of the different coordination modes of H{sub 2}PPA with the central atom in all structures have been studied, being found new coordination modes for this ligand. Several compounds show a significant increase in relative fluorescence with respect to the free phenanthroline. - Highlights: • Compounds have been obtained modifying the reaction time and the rate of reagents. • Dimensionality and crystalline structure is a function of the zinc environments. • New coordination modes for 2-carboxyethylphosphonic acid are reported. • 3D-compound presents three different coordination environments for the zinc atoms. • Fluorescence properties are related to the structural dimensionality.« less

Oxygen Permeability and Grain-Boundary Diffusion Applied to Alumina Scales

NASA Technical Reports Server (NTRS)

Smialek, James L.; Jacobson, Nathan S.; Gleeson, Brian; Hovis, David B.; Heuer, Arthur H.

2013-01-01

High-temperature oxygen permeability measurements had determined grain-boundary diffusivities (deltaD(sub gb)) in bulk polycrystalline alumina (Wada, Matsudaira, and Kitaoka). They predict that oxygen deltaD(sub gb,O) varies with oxygen pressure as P(O2)(sup -1/6) at low pressure whereas aluminum deltaD(sub gb),Al varies with P(O2)(sup +3/16) at high pressure. These relations were used to evaluate alumina scale growth in terms of diffusivity and grain size. A modified Wagner treatment for dominant inward oxygen growth produces the concise solution: ?(sub i) = k(sub p,i)×G(sub i) = 12 deltaD(sub gb,O,int), where ?(sub i) is a constant and k(sub p,i) and G(sub i) refer to instantaneous values of the scale parabolic growth constant and grain size, respectively. A commercial FeCrAl(Zr) alloy was oxidized at 1100 to 1400 degC to determine k(sub p,i), interfacial grain size, ?, and thus deltaD(sub gb,O,int). The deltaD(sub gb,O,int) values predicted from oxidation at (375 kJ/mole) were about 20 times less than those obtained above (at 298 kJ/mole), but closer than extrapolations from high-temperature bulk measurements. The experimental oxidation results agree with similar FeCrAl(X) studies, especially where both k(sub p,i) and G(sub i) were characterized. This complete approach accounts for temperature-sensitive oxidation effects of grain enlargement, equilibrium interface pressure variation, and grain-boundary diffusivity.

Photoelectron imaging of autoionizing states of xenon: Effect of external electric fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shubert, V. Alvin; Pratt, Stephen T.

Velocity map photoelectron imaging was used to study the photoelectron angular distributions of autoionizing Stark states of atomic xenon excited just below the Xe{sup +} {sup 2} P{sub 1/2}{sup o} threshold at fields ranging from 50 to 700 V/cm. Two-color, two-photon resonant, three-photon excitation via the 6p{sup '}[1/2]{sub 0} level was used to probe the region of interest. The wavelength scans show a similar evolution of structure to that observed in single-photon excitation [Ernst et al., Phys. Rev. A 37, 4172 (1988)]. The photoelectron angular distributions following autoionization of the Stark states provide information on the decay of excited statesmore » in electron fields. In the present experiments, the large autoionization width of the ({sup 2} P{sub 1/2}{sup o})nd[3/2]{sub 1}{sup o} series dominates the decay processes, and thus controls the angular distributions. However, the angular distributions of the Stark states also indicate the presence of other decay channels contributing to the decay of these states.« less

Observation of the $$\\Xi_b^0$$ Baryon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, T.; /Helsinki Inst. of Phys.; Alvarez Gonzalez, B.

The observation of the bottom, strange baryon {Xi}{sup 0}{sub b} through the decay chain {Xi}{sup 0}{sub b} {yields} {Xi}{sup +}{sub c} {pi}{sup -}, where {Xi}{sup +}{sub c} {yields} {Xi}{sup -} {pi}{sup +} {pi}{sup +}, {Xi}{sup -} {yields} {Lambda} {yields} p {pi}{sup -}, is reported using data corresponding to an integrated luminosity of 4.2 ft{sup -1} from p{anti p} collisions at {radical}{ovr s} = 1.96 TeV recorded with the Collider Detector at Fermilab. A signal of 25.3{sup +5.6}{sub -5.4} candidates is observed whose probability of arising from a background fluctuation is 3.6 x 10{sup -12}, corresponding to 6.8 Gaussian standard deviations.more » The {Xi}{sup 0}{sub b} mass is measured to be 5787.8 {+-} 5.0(stat) {+-} 1.3(syst) MeV/c{sup 2}. In addition, the {Xi}{sup -}{sub b} is observed through the process {Xi}{sup -}{sub b} {yields} {Xi}{sup 0}{sub c} {pi}{sup -}, where {Xi}{sup 0}{sub c} {yields} {Xi}{sup -} {pi}{sup +}, {Xi}{sup -} {yields} {Lambda} {pi}{sup -}, and {Lambda} {yields} p {pi}{sup -}.« less

Structure refinements of members in the brownmillerite solid solution series Ca{sub 2}Al{sub x}(Fe{sub 0.5}Mn{sub 0.5}){sub 2-x}O{sub 5+{delta}} with 1/2{<=}x{<=}4/3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoeber, Stefan, E-mail: stefan.stoeber@geo.uni-halle.de; Redhammer, Guenther; Schorr, Susan

2013-01-15

Four different brownmillerite solid solutions Ca{sub 2}Al{sub x}(Fe{sub 0.5}Mn{sub 0.5}){sub 2-x}O{sub 5+{delta}} with 1/2{<=}x{<=}4/3 were synthesized by a solid oxide ceramic method. The phases crystallize either in a primitive centered orthorhombic cell with space group Pnma or in a body centered cell with space group I2mb dependent on the aluminum concentration present in the solid solution. Mn{sup 3+} ions occupy exclusively site 4a coordinated by six oxygen anions. Increasing Mn{sup 3+} concentrations cause a remarkable distortion of the octahedron and indirectly of the tetrahedron, resulting in twisted and tilted octahedral layers as well as buckled tetrahedral chains. The influences aremore » discussed on the site 4a of trivalent manganese due to its Jahn-Teller activity, with regard to the occupation of octahedron and tetrahedron with different sized iron and aluminum ions. - Graphical Abstract: The coupled substitution Fe{sup 3+}>Mn{sup 3+}+Fe{sup 3+} <=>2 Al{sup 3+} in brownmillerite phases (Ca{sub 2}(Fe{sub 0.5}Mn{sub 0.5}){sub 2-x}Al{sub x}O{sub 5+{delta}}) changes predominantly their structural properties, which is essential for the hydration performance of the calcium aluminate cement, where brownmillerites occur as clinker phases. Highlights: Black-Right-Pointing-Pointer We present structural data of four Ca-Al-Fe-Mn-brownmillerites. Black-Right-Pointing-Pointer Mn{sup 3+}-ions occupy exclusively the octahedrally coordinated site 0,0,0. Black-Right-Pointing-Pointer Bonds and angles of the octahedrally coordinated site are distorted strongly. Black-Right-Pointing-Pointer Mn{sup 3+}-ions influence indirectly the shape of the tetrahedron. Black-Right-Pointing-Pointer Mn{sup 3+}-ions stabilize Pnma instead of I2mb in Ca-Al-Fe-Mn-brownmillerites.« less

Structural and dielectric properties of A(Fe{sub 1/2}Ta{sub 1/2})O{sub 3} [A = Ba, Sr, Ca

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dutta, Alo; Sinha, T.P., E-mail: sinha_tp@yahoo.com

2011-04-15

Graphical abstract: FTIR spectra of BFT, SFT and CFT at room temperature. Research highlights: {yields} The structural and dielectric properties of BaFe{sub 1/2}Ta{sub 1/2}O{sub 3}, SrFe{sub 1/2}Ta{sub 1/2}O{sub 3} and CaFe{sub 1/2}Ta{sub 1/2}O{sub 3}. {yields} Fourier transform infrared spectra show two primary phonon modes of the samples at around 450 cm{sup -1} and 620 cm{sup -1}. {yields} The compounds show significant frequency dispersion in its dielectric properties. {yields} The relaxation mechanism of the samples is modelled by Cole-Cole equation. -- Abstract: The complex perovskite oxide barium iron tantalate (BFT), BaFe{sub 1/2}Ta{sub 1/2}O{sub 3}, strontium iron tantalate (SFT), SrFe{sub 1/2}Ta{sub 1/2}O{submore » 3} and calcium iron tantalate (CFT), CaFe{sub 1/2}Ta{sub 1/2}O{sub 3} are synthesized by a solid-state reaction technique. Rietveld refinement of the X-ray diffraction data of the samples shows that BFT and SFT crystallize in cubic structure, with lattice parameter a = 4.06 A for BFT and 3.959 A for SFT, whereas CFT crystallizes in orthorhombic structure having lattice parameters a = 5.443 A, b = 5.542 A and c = 7.757 A. Fourier transform infrared spectra show two primary phonon modes of the samples at around 450 cm{sup -1} and 620 cm{sup -1}. The compounds show significant frequency dispersion in its dielectric properties. The complex impedance plane plots of the samples show that the relaxation (conduction) mechanism in these materials is purely a bulk effect arising from the semiconductive grains. The relaxation mechanism of the samples is modelled by Cole-Cole equation. The frequency dependent conductivity spectra are found to follow the power law.« less

Does having an asthmatic sibling affect the quality of life in children?

PubMed

Yılmaz, Özge; Türkeli, Ahmet; Karaca, Özlem; Yüksel, Hasan

2017-01-01

Yılmaz Ö, Türkeli A, Karaca Ö, Yüksel H. Does having an asthmatic sibling affect the quality of life in children? Turk J Pediatr 2017; 59: 274-280. Chronic illness in a family member leads to deterioration of quality of life in other members of that family. We aimed to investigate the influence of having an asthmatic sibling on a child`s quality of life (QoL). We enrolled 2-12 year aged healthy children with an asthmatic sibling in the study group and healthy children with a healthy sibling in the control group of this cross-sectional study. Sociodemographic characteristics of children and disease severity characteristics of asthmatic siblings were recorded. All parents filled in Turkish generic PedsQLTM short form appropriate for the child`s age group. Study and control groups had 114 children each. Total PedsQLTM scores were not significantly different in any of the age groups (p=0.23, p=0.13, p= 0.11 respectively). Emotional PedsQLTM sub-scores in children with an asthmatic sibling were significantly worse (83.0±16.5 vs 91.6±10.9 in the 2-4 year age group, 72.0±17.8 vs 92.2±11.6 in the 5-7 year age group, 73.7±24.1 vs 88.7±14.8 in the 8-12 year age group respectively, p≤0.002 for all). Similarly, psychosocial sub-score was significantly lower in the 2-4 and 5-7-year-olds but not the 8-12 year old groups (p=0.01, p=0.01, p=0.08 respectively). In conclusion, healthy children with asthmatic siblings have significantly lower emotional QoL and this needs to investigated for other chronic diseases in further research.

Negative parity states and some electromagnetic transition properties of even-odd erbium isotopes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yazar, Harun Resit; Uluer, Ihsan

2007-03-15

The negative parity states and some electromagnetic transition properties of even-odd erbium isotopes ({sup 159,161,163,165}Er) were studied within the framework of the interacting boson-fermion model. The single fermion is assumed to be in one of the lh{sub 9/2},3p{sub 3/2},2f{sub 5/2}, and 3p{sub 1/2} single-particle orbits. It was found that the calculated negative parity state energy spectra of the even-odd erbium isotopes agree quite well with the experimental data. The B(E2) values were also calculated and compared with the experimental data.

Monitoring Tumor Response to Carbogen Breathing by Oxygen-Sensitive Magnetic Resonance Parameters to Predict the Outcome of Radiation Therapy: A Preclinical Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao-Pham, Thanh-Trang; Tran, Ly-Binh-An; Colliez, Florence

Purpose: In an effort to develop noninvasive in vivo methods for mapping tumor oxygenation, magnetic resonance (MR)-derived parameters are being considered, including global R{sub 1}, water R{sub 1}, lipids R{sub 1}, and R{sub 2}*. R{sub 1} is sensitive to dissolved molecular oxygen, whereas R{sub 2}* is sensitive to blood oxygenation, detecting changes in dHb. This work compares global R{sub 1}, water R{sub 1}, lipids R{sub 1}, and R{sub 2}* with pO{sub 2} assessed by electron paramagnetic resonance (EPR) oximetry, as potential markers of the outcome of radiation therapy (RT). Methods and Materials: R{sub 1}, R{sub 2}*, and EPR were performed onmore » rhabdomyosarcoma and 9L-glioma tumor models, under air and carbogen breathing conditions (95% O{sub 2}, 5% CO{sub 2}). Because the models demonstrated different radiosensitivity properties toward carbogen, a growth delay (GD) assay was performed on the rhabdomyosarcoma model and a tumor control dose 50% (TCD50) was performed on the 9L-glioma model. Results: Magnetic resonance imaging oxygen-sensitive parameters detected the positive changes in oxygenation induced by carbogen within tumors. No consistent correlation was seen throughout the study between MR parameters and pO{sub 2}. Global and lipids R{sub 1} were found to be correlated to pO{sub 2} in the rhabdomyosarcoma model, whereas R{sub 2}* was found to be inversely correlated to pO{sub 2} in the 9L-glioma model (P=.05 and .03). Carbogen increased the TCD50 of 9L-glioma but did not increase the GD of rhabdomyosarcoma. Only R{sub 2}* was predictive (P<.05) for the curability of 9L-glioma at 40 Gy, a dose that showed a difference in response to RT between carbogen and air-breathing groups. {sup 18}F-FAZA positron emission tomography imaging has been shown to be a predictive marker under the same conditions. Conclusion: This work illustrates the sensitivity of oxygen-sensitive R{sub 1} and R{sub 2}* parameters to changes in tumor oxygenation. However, R{sub 1} parameters showed limitations in terms of predicting the outcome of RT in the tumor models studied, whereas R{sub 2}* was found to be correlated with the outcome in the responsive model.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Yue; Yang, Meng-Lin; Hu, Huai-Ming, E-mail: ChemHu1@NWU.EDU.CN

Six new coordination polymers, [ZnLCl]{sub n}(1), [ZnL{sub 2}]{sub n}·2nH{sub 2}O (2), [Zn{sub 2}L(o-bdc)(OH)]{sub n}·0.5nH{sub 2}O (3), [Zn{sub 2}L(m-bdc)(OH)]{sub n}·nH{sub 2}O (4), [Zn{sub 2}L{sub 2}(p-bdc) (H{sub 2}O){sub 2}]{sub n}·nH{sub 2}O (5), [Zn{sub 2}L(1,2,4-btc)(H{sub 2}O)]{sub n}(6), (HL=4′-(3-carboxyphenyl)- 3,2′:6′,3″-terpyridine, H{sub 2}(o-bdc)= benzene-1,2-dicarboxylic acid, H{sub 2}(m-bdc)= benzene-1,3-dicarboxylic acid, H{sub 2}(p-bdc)= benzene-1,4-dicarboxylic acid, H{sub 3}(1,2,4-btc)= benzene-1,2,4-tricarboxylic acid) have been synthesized under the hydrothermal conditions. Compound 1 displays a 3-connected 2D network structure with point symbol of {8"2.10}. Compound 2 exhibits 1D infinite loop chain structure. Compound 3 possesses a (3,8)-connected 3D framework composed of tetranuclear units with point symbol of {4"3}{sub 2}{4"6.6"1"8.8"4}. Compound 4 featuresmore » a typical 2D hcb network based on tetranuclear zinc(II) units with point symbol of {4"4.6"2}. Compound 5 presents a classical two-fold penetration sql network with point symbol of {6"3}. Compound 6 can be seen as a (3,3,6)-connected 3D net with point symbol of {4"2.6"4.8"9}{4"2.6}{6"3}. The thermal stability and luminescent properties of compounds 1–6 in the solid state are discussed in detail. - Graphical abstract: Six new Zn(II) coordination polymers based on multicarboxylate and terpyridyl derivative ligands have synthesized under the hydrothermal conditions and the thermal stability and luminescence are discussed. Display Omitted.« less

The structure of Na{sub 3}SbTe{sub 3}: How ionic and covalent bonding forces work together

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Jianhua; Miller, G.J.

1994-12-01

The compound Na{sub 3}SbTe{sub 3} has been synthesized from the elements and characterized by single crystal X-ray diffraction. Na{sub 3}SbTe{sub 3} is cubic, crystallizing in the cP28 structure type (isomorphous with Na{sub 3}AsS{sub 3}); space group P2{sub 1}3 (No. 198); a=9.6114(9) {angstrom}; Z = 4; R1 = 0.0324; wR2 = 0.0561 (I {le} 2{sigma}(I)). The structure consists of isolated sodium cations and trigonal pyramidal [SbTe{sub 3}]{sup {minus}3} anions with a Sb-Te bond length of 2.787(1) {angstrom} and a Te-Sb-Te bond angle of 100.0(1){degrees}. The structure is related to both the Li{sub 3}Bi and K{sub 3}AsS{sub 4}-type structures. Both lattice energymore » and semiempirical electronic structure calculations are utilized to evaluate various local and long-range structural aspects of this Zintl phase.« less

Crystal structures and electronic properties for the over-lithiated and Li–Ag substituted phases of Li{sub 9}V{sub 3}(P{sub 2}O{sub 7}){sub 3}(PO{sub 4}){sub 2} insertion electrode system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onoda, Masashige, E-mail: onoda.masashige.ft@u.tsukuba.ac.jp; Inagaki, Makoto; Saito, Hiroaki

2014-11-15

For the Li{sub 9}V{sub 3}(P{sub 2}O{sub 7}){sub 3}(PO{sub 4}){sub 2} insertion electrode system with a multiple-electron reaction, the over-lithiated phase Li{sub x}V{sub 3}(P{sub 2}O{sub 7}){sub 3}(PO{sub 4}){sub 2} with 99) and Li{sub 9−y}Ag{sub y}V{sub 3}(P{sub 2}O{sub 7}){sub 3}(PO{sub 4}){sub 2} (0

The Search for Exotic Mesons in gamma p -> pi+pi+pi-n with CLAS at Jefferson Lab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Craig Bookwalter

2011-12-01

The {pi}{sub 1}(1600), a J{sup PC} = 1{sup {-+}} exotic meson has been observed by experiments using pion beams. Theorists predict that photon beams could produce gluonic hybrid mesons, of which the {pi}{sub 1}(1600) is a candidate, at enhanced levels relative to pion beams. The g12 rungroup at Jefferson Lab's CEBAF Large Acceptance Spectrometer (CLAS) has recently acquired a large photoproduction dataset, using a liquid hydrogen target and tagged photons from a 5.71 GeV electron beam. A partial-wave analysis of 502K {gamma}p {yields} {pi}{sup +}{pi}{sup +}{pi}{sup -}n events selected from the g12 dataset has been performed, and preliminary fit resultsmore » show strong evidence for well-known states such as the a{sub 1}(1260), a{sub 2}(1320), and {pi}{sub 2}(1670). However, we observe no evidence for the production of the {pi}{sub 1}(1600) in either the partial-wave intensities or the relative complex phase between the 1{sup {-+}} and the 2{sup {-+}} (corresponding to the {pi}{sub 2}) partial waves.« less

Structural and electrical properties of nanostructured Ni{sub 0.25}Co{sub 0.75}MnP{sub 2}O{sub 7}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dhaouadi, Hassouna, E-mail: dhaouadihassouna@yahoo.fr; Kouass, Salah; Jaouad, Najeh

2014-01-01

Graphical abstract: - Highlights: • Nanostructured pyrophosphate Ni{sub 0.25}Co{sub 0.75}MnP{sub 2}O{sub 7} were synthesized and characterized by XRD and SEM. • The ac-conductivity at different values of temperature for Ni{sub 0.25}Co{sub 0.75}MnP{sub 2}O{sub 7} nanomaterials shows frequency independence in the lower frequency range. • Obvious improvements of the electrical conductivity and the electrochemical properties are achieved comparatively Mn{sub 2}P{sub 2}O{sub 7}. • The electrochemical behaviors of Ni{sub 0.25}Co{sub 0.75}MnP{sub 2}O{sub 7} were studied using cyclic voltammetry. - Abstract: The nanostructured pyrophosphate Ni{sub 0.25}Co{sub 0.75}MnP{sub 2}O{sub 7} was prepared. The synthesis technique was based on the hydrothermal method at 150 °Cmore » using poly-ethylene-glycol (PEG-10000) as surfactant with further calcination at 500 °C. A structural analysis of Ni{sub 0.25}Co{sub 0.75}MnP{sub 2}O{sub 7} compound was carried out by applying X-ray diffraction (XRD) and using the Rietveld method. Morphological characterizations were performed using a scanning electron microscope (SEM) and transmission electron microscopy (TEM). A comparative study of the electrical conductivity of Mn{sub 2}P{sub 2}O{sub 7} and Ni{sub 0.25}Co{sub 0.75}MnP{sub 2}O{sub 7} nanomaterials was carried out by impedance spectroscopy in the temperature range 500–680 °C. The activation energies for MnP{sub 2}O{sub 7} and Ni{sub 0.25}Co{sub 0.75}MnP{sub 2}O{sub 7} were 2.00 and 0.88 eV, respectively. Ni{sub 0.25}Co{sub 0.75}MnP{sub 2}O{sub 7} nanomaterial presents a good electric conductivity compared to Mn{sub 2}P{sub 2}O{sub 7}, due to the substitution effect. The improvement of the electronic and ionic conductivity makes the Ni{sub 0.25}Co{sub 0.75}MnP{sub 2}O{sub 7} nanomaterial possible electrode materials for rechargeable batteries. The electrochemical behaviors of Ni{sub 0.25}Co{sub 0.75}MnP{sub 2}O{sub 7} were studied using cyclic voltammetry.« less

Specific receptor for inositol-1,4,5-trisphosphate in permeabilized rabbit neutrophils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradford, P.G.; Spat, A.; Rubin, R.P.

1986-03-05

Neutrophil chemotaxis and degranulation are resultant, in part, from the mobilization of intracellular calcium by inositol-1,4,5-trisphosphate ((1,4,5)IP/sub 3/), one of the products of chemoattractant-stimulated phospholipase C activity. High specific activity (ca. 40 Ci/mmol) (/sup 32/P)(1,4,5)IP/sub 3/ was prepared from (..gamma..-/sup 32/P)ATP-labeled human erythrocyte ghosts and was used in binding assays with saponin-permeabilized rabbit peritoneal neutrophils. At 4/sup 0/C and in the presence of inhibitors of the IP/sub 3/ 5-phosphomonoesterase, (/sup 32/P)(1,4,5)IP/sub 3/ rapidly associated with a specific binding component which saturated within 60s. Nonspecific binding, taken as the residual binding in the presence of 10 ..mu..M (1,4,5)IP/sub 3/, was 15%more » of the total. No specific binding was detected using intact cells. The specific binding to permeable cells was reversible (t/sup 1/2/ approx. 60s) and could be inhibited in a dose-dependent manner by (1,4,5)IP/sub 3/ (EC/sub 50/ = 30 nM) and by other calcium mobilizing inositol phosphates ((2,4,5)IP/sub 3/) but not by inactive analogs ((1,4)IP/sub 2/, (4,5)IP/sub 2/, (1)IP). The dose-responses of (1,4,5)IP/sub 3/ and (2,4,5)IP/sub 3/ in inhibiting (/sup 32/P)(1,4,5)IP/sub 3/ specific binding correlated well with their abilities to release Ca/sup 2 +/ from nonmitochondrial vesicular stores in the same preparation of cells, suggesting that the authors have identified the physiological receptor for (1,4,5)IP/sub 3/.« less

Near-UV and blue wavelength excitable Mg{sub 0.6}Ca{sub 2.16}Mo{sub 0.2}W{sub 0.8}O{sub 6}: Eu{sub 0.12}{sup 3+}/Na{sub 0.12}{sup +} high efficiency red phosphors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khanna, A.; Electrical Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180; Dutta, P.S., E-mail: duttap@rpi.edu

Red phosphors with narrow emission around 615 nm (with FWHM~5–10 nm) having chemical compositions of A{sub 0.6}Ca{sub 2.16}Mo{sub 0.2}W{sub 0.8}O{sub 6}: Eu{sub 0.12}{sup 3+}/Na{sub 0.12}{sup +} (A=Mg, Sr) have been found to exhibit the highest luminescence amongst the molybdate–tungstate family when excited by sources in the 380–420 nm wavelength range. Thus they are most suitable for enhancing color rendering index and lowering color temperature in phosphor converted white LEDs (pc-WLEDs) with near-UV/blue LED excitation sources. The excitation band edge in the near UV/blue wavelength in the reported phosphor has been attributed to the coordination environment of the transition metal ionmore » (Mo{sup 6+}, W{sup 6+}) and host crystal structure. Furthermore the quantum efficiency of the phosphors has been enhanced by adjusting activator concentration, suitable compositional alloying using substitutional alkaline earth metal cations and charge compensation mechanisms. - Graphical abstract: The charge transfer excitation of orthorhombic Mg{sub 0.6}Ca{sub 2.16}Mo{sub 0.2}W{sub 0.8}O{sub 6}: Eu{sub 0.12}{sup 3+}/Na{sub 0.12}{sup +} is significantly higher than tetragonal CaMoO{sub 4}: Eu{sup 3+} phosphors making Mg{sub 0.6}Ca{sub 2.16}Mo{sub 0.2}W{sub 0.8}O{sub 6}: Eu{sub 0.12}{sup 3+}/Na{sub 0.12}{sup +} prime candidates for fabrication of warm white phosphor-converted LEDs. - Highlights: • LED excitable Mg{sub 0.6}Ca{sub 2.16}Mo{sub 0.2}W{sub 0.8}O{sub 6}: Eu{sub 0.12}{sup 3+}/Na{sub 0.12}{sup +} phosphors were synthesized. • These phosphors are 10 times more intense than CaMoO{sub 4}: Eu{sup 3+} red phosphors. • Their intensity and efficiency were enhanced by materials optimization techniques. • Such techniques include compositional alloying, charge compensation, etc.« less

Improved organic p-i-n type solar cells with n-doped fluorinated hexaazatrinaphthylene derivatives HATNA-F{sub 6} and HATNA-F{sub 12} as transparent electron transport material

DOE Office of Scientific and Technical Information (OSTI.GOV)

Selzer, Franz, E-mail: franz.selzer@iapp.de; Falkenberg, Christiane, E-mail: Christiane.Falkenberg@heliatek.com; Leo, Karl, E-mail: karl.leo@iapp.de

2014-02-07

We study new electron transport materials (ETM) to replace the reference material C{sub 60} in p-i-n type organic solar cells. A comprehensive material characterization is performed on two fluorinated hexaazatrinaphthylene derivatives, HATNA-F{sub 6} and HATNA-F{sub 12}, to identify the most promising material for the application in devices. We find that both HATNA derivatives are equally able to substitute C{sub 60} as ETM as they exhibit large optical energy gaps, low surface roughness, and sufficiently high electron mobilities. Furthermore, large electron conductivities of 3.5×10{sup −5} S/cm and 2.0×10{sup −4} S/cm are achieved by n-doping with 4 wt. % W{sub 2}(hpp){sub 4}. HOMO levels of (7.72 ± 0.05) eVmore » and (7.73 ± 0.05) eV are measured by ultraviolet photoelectron spectroscopy and subsequently used for estimating LUMO values of (4.2 ± 0.8) eV and (4.3 ± 0.8) eV. Both fluorinated HATNA derivatives are successfully applied in p-i-n type solar cells. Compared to identical reference devices comprising the standard material C{sub 60}, the power conversion efficiency (PCE) can be increased from 2.1 % to 2.4 % by using the new fluorinated HATNA derivatives.« less

Unification of the negative electrocaloric effect in Bi{sub 1/2}Na{sub 1/2}TiO{sub 3}-BaTiO{sub 3} solid solutions by Ba{sub 1/2}Sr{sub 1/2}TiO{sub 3} doping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uddin, Sarir; Materials Research Laboratory, Institute of Physics and Electronics, University of Peshawar, Peshawar 25120; Zheng, Guang-Ping, E-mail: mmzheng@polyu.edu.hk

2013-12-07

The microscopic mechanisms of the negative electrocaloric effect (ECE) of the single-phase (1−x)(0.94Bi{sub 1/2}Na{sub 1/2}TiO{sub 3}-0.06BaTiO{sub 3})-xBa{sub 1/2}Sr{sub 1/2}TiO{sub 3} (BNT-BT-BST) perovskite solid solutions fabricated via the sol-gel technique are explored in this study. Dielectric and mechanical relaxation analyses are employed to investigate the ferroelectric and structural transitions of the samples. The electrocaloric properties of the samples were measured by thermodynamics Maxwell relations. The difference between the depolarization temperature (T{sub d}) and the maximum dielectric constant temperature (T{sub m}) was found to decrease with increasing BST content. Doping with BST stabilized the ferroelectric phase along with unifying the EC temperaturemore » changes (ΔT) to only negative values. The origin of the uniform negative ECE of BNT-BT-BST is discussed.« less

Effect of Photodynamic Therapy with Posterior Sub-Tenon Triamcinolone Acetonide on Predominantly Classic Choroidal Neovascularization: One-Year Results

PubMed Central

Sertoz, Ayzin Deniz; Ates, Orhan; Keles, Sadullah; Kocer, Ibrahim; Kulacoglu, Destan Nil; Baykal, Orhan

2008-01-01

Objective: The aim of this study was to compare the results of monotherapy (photodynamic therapy) and combined therapy (photo-dynamic therapy with posterior sub-Tenon triamcinolone acetonide) in age-related macular degeneration (AMD). Materials and Methods: Forty eyes from forty patients with diagnosed neovascular AMD were enrolled in this study during March-2005 – October-2008. All patients were grouped in either the study or the control group. Both the study and control groups consisted of 20 eyes from 20 patients. The study group was treated with posterior sub-Tenon triamcinolone acetonide (PSTA) along with their initial photodynamic therapy (PDT) treatment. The control group members were treated with PDT alone. All patients were examined at 1, 3, 6 and 12 months. Visual acuity (VA), lesion size and number of treatment sessions were recorded during each examination. Results: The mean difference between pre- and post-treatment VA using the Snellen chart was +0.6 ± 1.7 in study group and −1.4 ± 1.7 in control. The difference for VA was significant in the study group as compared to control (p<0.05). The decrease in lesion size in the study group was 680±1195.2 µm, and the decrease was 32.75 ± 809.9 µm in the control. The difference with regard to the decrease in lesion sizes was significant in the study group as compared to the control (p<0.05). Total PDT treatment sessions were applied 1.2 times per patient in the study group and 1.9 times per patient in the control group. The difference was not significant (p>0.05). Conclusion: Our study showed that PSTA with PDT significantly reduces CNV growth, and improves VA at the 12-month follow-up in patients with AMD. PMID:25610041

Expression, purification and crystallization of Trypanosoma cruzi dihydroorotate dehydrogenase complexed with orotate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inaoka, Daniel Ken; Takashima, Eizo; Osanai, Arihiro

2005-10-01

The Trypanosoma cruzi dihydroorotate dehydrogenase, a key enzyme in pyrimidine de novo biosynthesis and redox homeostasis, was crystallized in complex with its first reaction product, orotate. Dihydroorotate dehydrogenase (DHOD) catalyzes the oxidation of dihydroorotate to orotate, the fourth step and the only redox reaction in the de novo biosynthesis of pyrimidine. DHOD from Trypanosoma cruzi (TcDHOD) has been expressed as a recombinant protein in Escherichia coli and purified to homogeneity. Crystals of the TcDHOD–orotate complex were grown at 277 K by the sitting-drop vapour-diffusion technique using polyethylene glycol 3350 as a precipitant. The crystals diffract to better than 1.8 Åmore » resolution using synchrotron radiation (λ = 0.900 Å). X-ray diffraction data were collected at 100 K and processed to 1.9 Å resolution with 98.2% completeness and an overall R{sub merge} of 7.8%. The TcDHOD crystals belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 67.87, b = 71.89, c = 123.27 Å. The presence of two molecules in the asymmetric unit (2 × 34 kDa) gives a crystal volume per protein weight (V{sub M}) of 2.2 Å{sup 3} Da{sup −1} and a solvent content of 44%.« less

Synthesis and physico-chemical studies on neodymium(III) and samarium(III) complexes with tetraaza macrocyclic ligands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goel, S.; Pandey, U.K.; Pandey, O.P.

1988-05-01

Reactions of neodymium trichloride and samarium trichloride with 6,7,13,14-R/sub 4/ - 3,10-X/sub 2/-(14)-5,7,12,14-tetraene-1,5,8,12-N/sub 4/-(2,4,9,11-N/sub 4/) (R = CH/sub 3/, X = 0 (L/sub 1//sup (1)/); R = C/sub 6/H/sub 5/, X = O (L/sub 1//sup (2)/); R = CH/sub 3/, X = S(L/sub 2//sup (1)/)) and R = C/sub 6/H/sub 5/, X = S(/sub 2//sup (2)/)) have been studied in ethanol and complexes of the type (M(L/sub 1//sup (1)/ or L/sub 1//sup (2)/))Cl/sub 3/ and (M(L/sub 2//sup (1)/ or L/sub 2//sup (2)/)(H/sub 2/O)/sub 2/)Cl/sub 3/ (M = Nd(III) and Sm(III)) have been isolated. In addition, macrocyclic complexes of Nd(III) andmore » Sm(III) with another series of tetraaza ligands, viz, 5,6,11,12-R/sub 4/-3,8-X/sub 2/-(12)-4,6,10,12-tetraene-1,4,7,10-N/sub 4/-(2,9-N/sub 2/) (R = CH/sub 3/, X = O (L/sub 3//sup (1)/); R = C/sub 6/H/sub 5/, X = O(L/sub 3//sup (2)/); R = CH/sub 3/, X = S(L/sub 4//sup (1)/); R = C/sub 6/H/sub 5/, X = S(L/sub 4//sup (2)/)), formulated as (M(L/sub 3//sup (1)/, L/sub 3//sup (2)/, L/sub 4//sup (1)/ or L/sub 4//sup (2)/)(H/sub 2/O)/sub 2/)Cl/sub 3/ (M = Nd(III) and Sm(III)) have been prepared by template condensation of Nd(III) and Sm(III) complexes of diacetylbis(semicarbazonethiosemicarbazone) or benzilibis(semicarbazonethiosemicarbazone) with diacetyl or benzil. The complexes have been identified by elemental analysis, electrical conductance, spectral and thermal measurements.« less

Na{sub 6}B{sub 13}O{sub 22.5}, a new noncentrosymmetric sodium borate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Penin, N.; Touboul, M.; Nowogrocki, G.

2005-03-15

Na{sub 6}B{sub 13}O{sub 22.5} (B/Na=2.17) single crystals were obtained by heating, melting and appropriately cooling borax, Na{sub 2}[B{sub 4}O{sub 5}(OH){sub 4}].8H{sub 2}O. Its formula has been determined by the resolution of the structure from single-crystal X-ray diffraction data. The compound crystallizes in the noncentrosymmetric orthorhombic Iba2 space group, with the following unit cell parameters: a=33.359(11)A, b=9.554(3)A, c=10.644(4)A; V=3392.4(19)A{sup 3}; Z=8. The crystal structure was solved from 3226 reflections until R{sub 1}=0.0385. It exhibits a three-dimensional framework built up from BO{sub 3} triangles ({delta}) and BO{sub 4} tetrahedra (T). Two kinds of borate groups can be considered forming two different doublemore » B{sub 3}O{sub 3} rings: two B{sub 4}O{sub 9} (linkage by two boron atoms) and one B{sub 5}O{sub 11} (linkage by one boron atom); the shorthand notation of the new fundamental building block (FBB) existing in this compound is: 13: {infinity}{sup 3} [(5: 3{delta}+2T)+2(4: 2{delta}+2T)]. The discovery of this new borate questions the real number of Na{sub 2}B{sub 4}O{sub 7} varieties. The existence of Na{sub 6}B{sub 13}O{sub 22.5} (B/Na=2.17) and of another recently discovered borate, Na{sub 3}B{sub 7}O{sub 12} (B/Na=2.33; FBB 7: {infinity}{sup 3} [(3: 2{delta}+T)+(3: {delta}+2T)+(1: {delta})], with a composition close to the long-known borate {alpha}-Na{sub 2}B{sub 4}O{sub 7} (B/Na=2; FBB 8: {infinity}{sup 3} [(5: 3{delta}+2T)+(3: 2{delta}+T)], may explain the very complex equilibria reported in the Na{sub 2}O-B{sub 2}O{sub 3} phase diagram, especially in this range of composition.« less

First measurement of target and double spin asymmetries for e-vectorp-vector{yields}ep{pi}{sup 0} in the nucleon resonance region above the {delta}(1232)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biselli, A. S.; Burkert, V. D.; Avakian, H.

2008-10-15

The exclusive channel p-vectore-vector,e{sup '}p){pi}{sup 0} was studied in the first and second nucleon resonance regions in the Q{sup 2} range from 0.187 to 0.770 GeV{sup 2} at Jefferson Lab using the CEBAF Large Acceptance Spectrometer. Longitudinal target and beam-target asymmetries were extracted over a large range of center-of-mass angles of the {pi}{sup 0} and compared to the unitary isobar model MAID, the dynamic model by Sato and Lee, and the dynamic model DMT. A strong sensitivity to individual models was observed, in particular for the target asymmetry and in the higher invariant mass region. This data set, once includedmore » in the global fits of the above models, is expected to place strong constraints on the electrocoupling amplitudes A{sub 1/2} and S{sub 1/2} for the Roper resonance N(1400)P{sub 11} and the N(1535)S{sub 11} and N(1520)D{sub 13} states.« less

Synthesis, structure and electrical properties of Cu{sub 3.21}Ti{sub 1.16}Nb{sub 2.63}O{sub 12} and the CuO{sub x}-TiO{sub 2}-Nb{sub 2}O{sub 5} pseudoternary phase diagram

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reeves-McLaren, Nik, E-mail: n.reeves@sheffield.ac.uk; Ferrarelli, Matthew C.; Tung, Yuan-Wei

2011-07-15

Subsolidus phase relations in the CuO{sub x}-TiO{sub 2}-Nb{sub 2}O{sub 5} system were determined at 935 deg. C. The phase diagram contains one new phase, Cu{sub 3.21}Ti{sub 1.16}Nb{sub 2.63}O{sub 12} (CTNO) and one rutile-structured solid solution series, Ti{sub 1-3x}Cu{sub x}Nb{sub 2x}O{sub 2}: 0 Subsolidus phase relations in the CuO{sub x}-TiO{sub 2}-Nb{sub 2}O{sub 5} system were determined at 935 deg. C. > A new phase, Cu{sub 3.21}Ti{sub 1.16}Nb{sub 2.63}O{sub 12} (CTNO), was found with a CaCu{sub 3}Ti{sub 4}O{sub 12}-like crystal structure. > We discovered one rutile-structured solid solution series, Ti{sub 1-3x}Cu{sub x}Nb{sub 2x}O{sub 2}: 0 CTNO has square planar Cu{sup 2+}, A site vacancies and Cu{sup +}, Ti{sup 4+} and Nb{sup 5+} disordered on octahedral sites. > CTNO is a modest semiconductor with relative permittivity {approx}63.« less

Syntheses and crystal structures of two new hydrated borates, Zn{sub 8}[(BO{sub 3}){sub 3}O{sub 2}(OH){sub 3}] and Pb[B{sub 5}O{sub 8}(OH)].1.5H{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Xuean; Zhao Yinghua; Chang Xinan

Two new hydrated borates, Zn{sub 8}[(BO{sub 3}){sub 3}O{sub 2}(OH){sub 3}] and Pb[B{sub 5}O{sub 8}(OH)].1.5H{sub 2}O, have been prepared by hydrothermal reactions at 170 {sup o}C. Single-crystal X-ray structural analyses showed that Zn{sub 8}[(BO{sub 3}){sub 3}O{sub 2}(OH){sub 3}] crystallizes in a non-centrosymmetric space group R32 with a=8.006(2) A, c=17.751(2) A, Z=3 and Pb[B{sub 5}O{sub 8}(OH)].1.5H{sub 2}O in a triclinic space group P1-bar with a=6.656(2) A, b=6.714(2) A, c=10.701(2) A, {alpha}=99.07(2){sup o}, {beta}=93.67(2){sup o}, {gamma}=118.87(1){sup o}, Z=2. Zn{sub 8}[(BO{sub 3}){sub 3}O{sub 2}(OH){sub 3}] represents a new structure type in which Zn-centered tetrahedra are connected via common vertices leading to helical ribbons {submore » {infinity}} {sup 1}[Zn{sub 8}O{sub 15}(OH){sub 3}]{sup 17-} that pack side by side and are further condensed through sharing oxygen atoms to form a three-dimensional {sub {infinity}} {sup 3}[Zn{sub 8}O{sub 11}(OH){sub 3}]{sup 9-} framework. The boron atoms are incorporated into the channels in the framework to complete the final structure. Pb[B{sub 5}O{sub 8}(OH)].1.5H{sub 2}O is a layered compound containing double ring [B{sub 5}O{sub 8}(OH)]{sup 2-} building units that share exocyclic oxygen atoms to form a two-dimensional layer. Symmetry-center-related layers are stacked along the c-axis and held together by interlayer Pb{sup 2+} ions and water molecules via electrostatic and hydrogen bonding interactions. The IR spectra further confirmed the existence of both triangular BO{sub 3} and OH groups in Zn{sub 8}[(BO{sub 3}){sub 3}O{sub 2}(OH){sub 3}], and BO{sub 3}, BO{sub 4}, OH groups as well as guest water molecules in Pb[B{sub 5}O{sub 8}(OH)].1.5H{sub 2}O. -- Zn{sub 8}[(BO{sub 3}){sub 3}O{sub 2}(OH){sub 3}] represents a new structure type in which Zn-centered tetrahedra are connected via common vertices to form a three-dimensional framework. The boron atoms are incorporated into the channels in the framework to strengen the structure via B-O bonds. Pb[B{sub 5}O{sub 8}(OH)].1.5H{sub 2}O is a new layered material containing double ring [B{sub 5}O{sub 8}(OH)]{sup 2-} building units that share exocyclic oxygen atoms to form a two-dimensional layer.« less

Responses of older men with and without chronic obstructive pulmonary disease to prolonged ozone exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gong, H. Jr.; Shamoo, D.A.; Anderson, K.R.

1997-01-01

We tested responses to ozone (O{sub 3}) under simulated {open_quotes}worst-case{close_quotes} ambient exposure conditions. Subjects included 9 men who had severe chronic obstructive pulmonary disease (COPD) with subnormal carbon monoxide diffusing capacity (i.e., an emphysemic component) and 10 age-matched healthy men. Each subject was exposed to 0.24 ppm O{sub 3} and to clean air (control) in an environmentally controlled chamber at 24{degrees}C and 40% relative humidity. Exposures were randomized, they occurred 1 wk apart, and they lasted 4 h. During each half-hour interval, light exercise occurred (e.e., average ventilation 20 l/mm) for 15 min. during both control and O{sub 3} exposures,more » group mean symptom intensity and specific airway resistance (SRaw) increased, whereas forced expiratory performance decreased. The healthy subgroup`s mean arterial oxygen saturation (SaO{sub 2}) rose slightly, and the COPD subgroup`s mean SaO{sub 2} declined slightly, during exercise. Group mean forced expiratory volume in 1 s (FEV{sub 1.0}) declined significantly in O{sub 3} exposures, compared with controls (p {approx}.01). Mean excess FEV{sub 1.0} loss after 4 h in O{sub 3} (relative to control) was 8% of the preexposure value in the COPD subgroup, compared with 3% in the healthy subgroup (p > .05 [nonsignificant]). Overall FEV{sub 1.0} loss during O{sub 3} exposures, including exercise effects, averaged 19% in the COPD subgroup, compared with 2% in the healthy subgroup (p < .001). Symptoms, SRaw, and SaO{sub 2} responses, as well as healthy subjects` postexposure bronchial reactivity, differed little between O{sub 3}-exposed and control subjects. We therefore concluded that in older men with or without severe COPD, O{sub 3} causes lung dysfunction under {open_quotes}worst-case{close_quotes} ambient exposure conditions, despite older subjects` comparative unresponsiveness to O{sub 3}. 30 refs., 2 figs., 2 tabs.« less

Pb(B{sup {prime}}{sub 1/2}B{sup {prime}{prime}}{sub 1/2})O{sub 3}-type perovskites: Part II. Short-range order parameter as a criterion of the distinction between relaxor and normal ferroelectrics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, S.; Jang, H.M.

1997-08-01

A classification scheme of Pb(B{sup {prime}}{sub 1/2}B{sup {prime}{prime}}{sub 1/2})O{sub 3}-type perovskites with respect to the B-site order parameters was proposed based on the theoretical calculation of the short-range order parameter ({sigma}) using the pair-correlation model. The calculated order parameters predict that a Pb(B{sup {prime}}{sub 1/2}B{sup {prime}{prime}}{sub 1/2})O{sub 3}-type perovskite without any charge difference between B{sup {prime}} and B{sup {prime}{prime}} cations [e.g., Pb(Zr{sub 1/2}Ti{sub 1/2})O{sub 3} (PZT)] is represented by a completely disordered state with the absence of a finite coherence length. On the other hand, a Pb(B{sup {prime}}{sub 1/2}B{sup {prime}{prime}}{sub 1/2})O{sub 3} type perovskite system having different ionic charges ismore » characterized either by the short-range ordering with a nanoscale coherence length or by the macroscopic long-range ordering, depending on the magnitude of ionic charge difference between B{sup {prime}} and B{sup {prime}{prime}} ions. The normal ferroelectricity in Pb(B{sup {prime}}{sub 1/2}B{sup {prime}{prime}}{sub 1/2})O{sub 3}-type complex perovskites was then correlated either with a completely disordered state ({sigma}=0) or with a perfectly ordered state ({sigma}=1), whereas the relaxor behavior was attributed to the nanoscale short-range ordering (0{lt}{sigma}{lt}1) in the configuration of the B-site cations. {copyright} {ital 1997 Materials Research Society.}« less

Stimulation of a Ca sup 2+ -dependent protein kinase by G sub M1 ganglioside in nerve growth factor-treated PC12 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hilbush, B.S.; Levine, J.M.

1991-07-01

The authors have investigated the ability of exogenous gangliosides to modulate nerve growth factor (NGF) signal transduction in PC12 cells. The effects of exogenous ganglioside G{sub M1} on multiple protein kinase activities were assayed by analyzing site-specific serine phosphorylation of tyrosine hydroxylase (TyrOHase) by two-dimensional phosphopeptide mapping. In the presence of NGF, exogenous G{sub M1} increased {sup 32}P incorporation into TyrOHase phosphopeptide T2, a Ca{sup 2+}/calmodulin-dependent protein kinase substrate whose phosphorylation is not normally affected by NGF treatment. In the absence of NGF, G{sub M1} treatment had no significant effects on TyrOHase phosphorylation. The removal of extracellular Ca{sup 2+} ormore » blockade of dihydropyridine-sensitive Ca{sup 2+} channels prevented the G{sub M1}-induced increases in {sup 32}P incorporation into phosphopeptide T2. Exogenous G{sub M1} also potentiated K{sup +} depolarization-induced increases in the phosphorylation of TyrOHase. These results suggest that the stimulatory effects of exogenous G{sub M1} ganglioside on NGF actions may be due to its ability to potentiate a Ca{sup 2+}-dependent signaling pathway.« less

A multi-institutional study to assess adherence to lung stereotactic body radiotherapy planning goals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woerner, Andrew; Roeske, John C.; Harkenrider, Matthew M.

2015-08-15

Purpose: A multi-institutional planning study was performed to evaluate the frequency that current guidelines established by Radiation Therapy Oncology Group (RTOG) protocols and other literature for lung stereotactic body radiotherapy (SBRT) treatments are followed. Methods: A total of 300 patients receiving lung SBRT treatments in four different institutions were retrospectively reviewed. The treatments were delivered using Linac based SBRT (160 patients) or image guided robotic radiosurgery (140). Most tumors were located peripherally (250/300). Median fractional doses and ranges were 18 Gy (8–20 Gy), 12 Gy (6–15 Gy), and 10 Gy (5–12 Gy) for three, four, and five fraction treatments, respectively.more » The following planning criteria derived from RTOG trials and the literature were used to evaluate the treatment plans: planning target volumes, PTV{sub V} {sub 100} ≥ 95% and PTV{sub V} {sub 95} ≥ 99%; conformality indices, CI{sub 100%} < 1.2 and CI{sub 50%} range of 2.9–5.9 dependent on PTV; total lung-ITV: V{sub 20Gy} < 10%, V{sub 12.5Gy} < 15%, and V{sub 5Gy} < 37%; contralateral lung V{sub 5Gy} < 26%; and maximum doses for spinal cord, esophagus, trachea/bronchus, and heart and great vessels. Populations were grouped by number of fractions, and dosimetric criteria satisfaction rates (CSRs) were reported. Results: Five fraction regimens were the most common lung SBRT fractionation (46%). The median PTV was 27.2 cm{sup 3} (range: 3.8–419.5 cm{sup 3}). For all plans: mean PTV{sub V} {sub 100} was 94.5% (±5.6%, planning CSR: 69.8%), mean PTV{sub V} {sub 95} was 98.1% (±4.1%, CSR: 69.5%), mean CI{sub 100%} was 1.14 (±0.21, CSR: 79.1%, and 16.5% within minor deviation), and mean CI{sub 50%} was 5.63 (±2.8, CSR: 33.0%, and 28.0% within minor deviation). When comparing plans based on location, peripherally located tumors displayed higher PTV{sub V} {sub 100} and PTV{sub V} {sub 95} CSR (71.5% and 71.9%, respectively) than centrally located tumors (61.2% and 57.1%, respectively). Overall, the planning criteria were met for all the critical structure such as lung, heart, spinal cord, esophagus, and trachea/bronchus for at least 85% of the patients. Conclusions: Among the various parameters that were used to evaluate the SBRT plans, the CI{sub 100%} and CI{sub 50%} were the most challenging criteria to meet. Although the CSRs of organs at risk were higher among all cases, their proximity to the PTV was a significant factor.« less

Production, Purification, Crystallization and Preliminary X-ray Structural Studies of Adeno-Associated Virus Serotype 5

DOE Office of Scientific and Technical Information (OSTI.GOV)

DiMattia,M.; Govindasamy, L.; Levy, H.

2005-01-01

Adeno-associated virus serotype 5 (AAV5) is under development for gene-therapy applications for the treatment of cystic fibrosis. To elucidate the structural features of AAV5 that control its enhanced transduction of the apical surface of airway epithelia compared with other AAV serotypes, X-ray crystallographic studies of the viral capsid have been initiated. The production, purification, crystallization and preliminary crystallographic analysis of empty AAV5 viral capsids are reported. The crystals diffract X-rays to beyond 3.2 Angstroms resolution using synchrotron radiation and belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 264.7, b = 447.9, c =more » 629.7 Angstroms. There is one complete T = 1 viral capsid per asymmetric unit. The orientation and position of the viral capsid in the asymmetric unit have been determined by rotation and translation functions, respectively, and the AAV5 structure determination is in progress.« less

Cobalt–iron nano catalysts supported on TiO{sub 2}–SiO{sub 2}: Characterization and catalytic performance in Fischer–Tropsch synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feyzi, Mostafa, E-mail: Dalahoo2011@yahoo.com; Yaghobi, Nakisa; Eslamimanesh, Vahid

2015-12-15

Graphical abstract: The Co–Fe/TiO{sub 2}–SiO{sub 2} catalysts were prepared. The prepared catalysts were tested for light olefins and C{sub 5}–C{sub 12} production. The best operational conditions are 250 °C, H{sub 2}/CO = 1/1 under 5 bar pressure. - Highlights: • The TiO{sub 2}–SiO{sub 2} supported cobalt–iron catalysts were prepared via sol–gel method. • The best operational conditions were 250 °C, GHSV = 2000 h{sup −1}, H{sub 2}/CO = 1/1 and 5 bar. • The (Co/Fe)/TiO{sub 2}–SiO{sub 2} is efficient catalyst for light olefins and C{sub 5}–C{sub 12} production. - Abstract: A series of Co–Fe catalysts supported on TiO{sub 2}–SiO{sub 2}more » were prepared by the sol–gel method. This research investigated the effects of (Co/Fe) wt.%, the solution pH, different Co/Fe molar ratio, calcination conditions and different promoters on the catalytic performance of cobalt–iron catalysts for the Fisher–Tropsch synthesis (FTS). It was found that the catalyst containing 35 wt.% (Co–Fe)/TiO{sub 2}–SiO{sub 2} (Co/Fe molar ratio is 80/20) promoted with 1.5 wt.% Cu and calcined in air atmosphere at 600 °C for 7 h with a heating rate of 3 °C min{sup −1} is an optimal nano catalyst for converting synthesis gas to light olefins and C{sub 5}–C{sub 12} hydrocarbons. The effects of operational conditions such as the H{sub 2}/CO ratio, gas hourly space velocity (GHSV), different reaction temperature, and reaction pressure were investigated. The results showed that the best operational conditions for optimal nano catalyst are 250 °C, GHSV = 2000 h{sup −1}, H{sub 2}/CO molar ratio 1/1 under 5 bar total pressure. Catalysts and precursors were characterized by, X-ray diffraction (XRD), scanning electron microcopy (SEM), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), temperature program reduction (TPR) and N{sub 2} adsorption–desorption measurements.« less

Hierarchical domain structure of lead-free piezoelectric (Na{sub 1/2} Bi{sub 1/2})TiO{sub 3}-(K{sub 1/2} Bi{sub 1/2})TiO{sub 3} single crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Chengtao, E-mail: lchentao@vt.edu; Wang, Yaojin; Ge, Wenwei

2016-05-07

We report a unique hierarchical domain structure in single crystals of (Na{sub 1/2}Bi{sub 1/2})TiO{sub 3}-xat. %(K{sub 1/2}Bi{sub 1/2})TiO{sub 3} for x = 5 and 8 by transmission electron microscopy (TEM). A high density of polar nano-domains with a lamellar morphology was found, which were self-assembled into a quadrant-like configuration, which then assembled into conventional ferroelectric macro-domains. Studies by high resolution TEM revealed that the polar lamellar regions contained a coexistence of in-phase and anti-phase oxygen octahedral tilt regions of a few nanometers in size. Domain frustration over multiple length scales may play an important role in the stabilization of the hierarchy, andmore » in reducing the piezoelectric response of this Pb-free piezoelectric solid solution.« less

Double-Diffusive Finger Convection: Flow Field Evolution in a Hele-Shaw Cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

COOPER,CLAY A.; GLASS JR.,ROBERT J.; TYLER,SCOTT W.

Double-diffusive finger convection is a hydrodynamic instability that can occur when two components with different diffusivities are oppositely stratified with respect to the fluid density gradient as a critical condition is exceeded. Laboratory experiments were designed using sodium chloride and sucrose solutions in a Hele-Shaw cell. A high resolution, full field, light transmission technique was used to study the development of the instability. The initial buoyancy ratio (R{sub p}), which is a ratio of fluid density contributions by the two solutes, was varied systematically in the experiments so that the range of parameter space spanned conditions that were nearly stablemore » (R{sub p} = 2.8) to those that were moderately unstable (R{sub p} = 1.4). In systems of low R{sub p}, fingers develop within several minutes, merge with adjacent fingers, form conduits, and stall before newer-generated fingers travel through the conduits and continue the process. Solute fluxes in low R{sub p} systems quickly reach steady state and are on the order of 10{sup {minus}6} m{sup 2} sec{sup {minus}1}. In the higher R{sub p} experiments, fingers are slower to evolve and do not interact as dynamically as in the lower R{sub p} systems. Our experiment with initial R{sub p} = 2.8 exhibited flux on the order of that expected for a similar diffusive system (i.e., 10{sup {minus}7} m{sup 2} sec{sup {minus}1}), although the structures were very different than the pattern of transport expected in a diffusing system. Mass flux decayed as t{sup 1/2} in two experiments each with initial R{sub p} = 2.4 and 2.8.« less

Crystalline ZrTiO{sub 4} gated p-metal–oxide–semiconductor field effect transistors with sub-nm equivalent oxide thickness featuring good electrical characteristics and reliability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Chao-Yi; Hsieh, Ching-Heng; Lee, Ching-Wei

2015-02-02

ZrTiO{sub 4} crystallized in orthorhombic (o-) phase was stacked with an amorphous Yb{sub 2}O{sub 3} interfacial layer as the gate dielectric for Si-based p-MOSFETs. With thermal annealing after gate electrode, the gate stack with equivalent oxide thickness (EOT) of 0.82 nm achieves high dielectric quality by showing a low interface trap density (D{sub it}) of 2.75 × 10{sup 11 }cm{sup −2}eV{sup −1} near the midgap and low oxide traps. Crystallization of ZrTiO{sub 4} and post metal annealing are also proven to introduce very limited amount of metal induced gap states or interfacial dipole. The p-MOSFETs exhibit good sub-threshold swing of 75 mV/dec which is ascribedmore » to the low D{sub it} value and small EOT. Owing to the Y{sub 2}O{sub 3} interfacial layer and smooth interface with Si substrate that, respectively, suppress phonon and surface roughness scattering, the p-MOSFETs also display high hole mobility of 49 cm{sup 2}/V-s at 1 MV/cm. In addition, I{sub on}/I{sub off} ratio larger than 10{sup 6} is also observed. From the reliability evaluation by negative bias temperature instability test, after stressing with an electric field of −10 MV/cm at 85 °C for 1000 s, satisfactory threshold voltage shift of 12 mV and sub-threshold swing degradation of 3% were obtained. With these promising characteristics, the Yb{sub 2}O{sub 3}/o-ZrTiO{sub 4} gate stack holds the great potential for next-generation electronics.« less

Hydrothermal synthesis, crystal structure and properties of 2-D and 3-D lanthanide sulfates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu Yan; Ding Shaohua; Zheng Xuefang

2007-07-15

Two new lanthanum sulfates DySO{sub 4}(OH) 1 and Eu{sub 2}(SO{sub 4}){sub 3}(H{sub 2}O){sub 8} 2 have been hydrothermally synthesized. The colorless crystals were characterized by IR, TGA, ICP and XRD. The structure was determined by single-crystal X-ray diffraction. 1 crystallizes with monoclinic symmetry, space group P2(1)/n [a=7.995(4) A, b=10.945(5) A, c=8.164(4) A, {alpha}=90{sup o}, {beta}=93.619(6){sup o}, {gamma}=90{sup o}, V=713.0(5) A{sup 3}, Z=8]. It displays a three-dimensional framework, based on the novel Dy-O chains connected by the sulfate groups through helical chains. 2 crystallizes with monoclinic symmetry, space group C2/c, [a=13.5605(17) A, b=6.7676(8) A, c=18.318(2) A, {alpha}=90{sup o}, {beta}=102.265(2){sup o}, {gamma}=90{supmore » o}, V=1642.7 (4) A{sup 3}, Z=4]. Its layered framework is attained by the europium atoms connected by the sulfate groups arranged in a helical manner. - Graphical abstract: Two new lanthanum sulfates DySO{sub 4}(OH) 1 and Eu{sub 2} (SO{sub 4}){sub 3} (H{sub 2}O){sub 8} 2 have been hydrothermally synthesized. The colorless crystals were characterized by IR, TGA, ICP and XRD. The structure was determined by single-crystal X-ray diffraction. It displays a three dimensional framework, based on the novel Dy-O chains connected by the sulfate groups through helical chains.« less

Synthesis, structure, and characterization of two new bismuth(III) selenite/tellurite nitrates: [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and [Bi(TeO{sub 3})](NO{sub 3})

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meng, Chang-Yu; Wei, Ming-Fang; Geng, Lei, E-mail: lgeng.cn@gmail.com

Two new bismuth(III) selenite/tellurite nitrates, [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and [Bi(TeO{sub 3})](NO{sub 3}), have been synthesized by conventional facile hydrothermal method at middle temperature 200 °C and characterized by single-crystal X-ray diffraction, powder diffraction, UV–vis–NIR optical absorption spectrum, infrared spectrum and thermal analylsis. Both [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and [Bi(TeO3)](NO3) crystallize in the monoclinic centronsymmetric space group P2{sub 1}/c with a=9.9403(4) Å, b=9.6857(4) Å, c=10.6864(5) Å, β=93.1150(10)° for [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and a=8.1489(3) Å, b=9.0663(4) Å, c=7.4729(3) Å, β=114.899(2)° for Bi(TeO3)(NO3), respectively. The two compounds, whose structures are composed of three different asymmetricmore » building units, exhibit two different types of structures. The structure of [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) features a three-dimensional (3D) bismuth(III) selenite cationic tunnel structure [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}] {sup 3}{sub ∞} with NO{sub 3}{sup −} anion group filling in the 1D tunnel along b axis. The structure of [Bi(TeO{sub 3})](NO{sub 3}) features 2D bismuth(III) tellurite [Bi(TeO{sub 3}){sub 2}]{sup 2}{sub ∞} layers separated by NO{sub 3}{sup −} anion groups. The results of optical diffuse-reflectance spectrum measurements and electronic structure calculations based on density functional theory methods show that the two compounds are wide band-gap semiconductors. - Graphical abstract: Two novel bismuth{sup III} selenite/tellurite nitrates [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) with 3D tunnel structure and [Bi(TeO{sub 3})](NO{sub 3}) with 2D layer structure have been firstly synthesized and characterized. Display Omitted - Highlights: • Two novel bismuth{sup III} nitrates [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and [Bi(TeO{sub 3})](NO{sub 3}) were firstly synthesized. • The two compounds were wide band-gap semiconductors.« less

TURBULENCE-INDUCED RELATIVE VELOCITY OF DUST PARTICLES. IV. THE COLLISION KERNEL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Liubin; Padoan, Paolo, E-mail: lpan@cfa.harvard.edu, E-mail: ppadoan@icc.ub.edu

Motivated by its importance for modeling dust particle growth in protoplanetary disks, we study turbulence-induced collision statistics of inertial particles as a function of the particle friction time, τ{sub p}. We show that turbulent clustering significantly enhances the collision rate for particles of similar sizes with τ{sub p} corresponding to the inertial range of the flow. If the friction time, τ{sub p,} {sub h}, of the larger particle is in the inertial range, the collision kernel per unit cross section increases with increasing friction time, τ{sub p,} {sub l}, of the smaller particle and reaches the maximum at τ{sub p,}more » {sub l} = τ{sub p,} {sub h}, where the clustering effect peaks. This feature is not captured by the commonly used kernel formula, which neglects the effect of clustering. We argue that turbulent clustering helps alleviate the bouncing barrier problem for planetesimal formation. We also investigate the collision velocity statistics using a collision-rate weighting factor to account for higher collision frequency for particle pairs with larger relative velocity. For τ{sub p,} {sub h} in the inertial range, the rms relative velocity with collision-rate weighting is found to be invariant with τ{sub p,} {sub l} and scales with τ{sub p,} {sub h} roughly as ∝ τ{sub p,h}{sup 1/2}. The weighting factor favors collisions with larger relative velocity, and including it leads to more destructive and less sticking collisions. We compare two collision kernel formulations based on spherical and cylindrical geometries. The two formulations give consistent results for the collision rate and the collision-rate weighted statistics, except that the spherical formulation predicts more head-on collisions than the cylindrical formulation.« less

A family of entangled coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and auxiliary N-donor ligands: Luminescent sensing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jun; College of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Zigong 643000; Bai, Chao

Eight Zn(II)-based coordination polymers, namely, [Zn{sub 2}L{sub 2}(2,2’-bipy)]{sub n}·nH{sub 2}O (1), [Zn{sub 2}L{sub 2}(phen)]{sub n}·nH{sub 2}O (2), [ZnL(phen)(H{sub 2}O)]{sub n} (3), [Zn{sub 3}L{sub 3}(4,4’-bipy)]{sub n} (4), [Zn{sub 2}L{sub 2}(4,4’-bipy){sub 2}]{sub n} [Zn{sub 2}L{sub 2}(H{sub 2}O){sub 2}]{sub n}·2nH{sub 2}O (5), [Zn{sub 4}L{sub 4}(bpp){sub 2}]{sub n} (6), [ZnL(bbi){sub 0.5}]{sub n} (7), [ZnL(bpz)]{sub n} (8) (H{sub 2}L=4,4’-([1,2-phenylenebis-(methylene)]bis(oxy))dibenzoic acid, 2,2’-bipy =2,2’-bipyridine, phen =1,10-phenanthroline, 4,4’-bpy=4,4’-bipyridine, bpp =1,3-bis(4-pyridyl)propane, bbi=1,4-bis(imidazol-1-yl)butane, bpz=3,3′,5,5′-tetramethyl-4,4′-bipyrazole), have been hydrothermally synthesized and structurally characterized. 1–8 display various coordination motifs with different entangled forms and conformations due to the effect of the assistant N-donor ligands. The photoluminescent properties of compounds 1–8 in solid statemore » were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu{sup 2+} cations and CrO{sub 4}{sup 2-} anions, as well as detection ability for the different organic solvents and nitro explosives. These results indicated that it could be utilized as a multi-responsive luminescent sensor. Furthermore, compound 3 also shows good chemical resistance to both acidity and alkalinity solutions with pH ranging from 2 to 13. Thus, multi-photofunctionality and fluorescent response to pH have been combined in the 3, which is the first example in the Zn-based hybrid materials. - Graphical abstract: Eight new Zn(II)-based coordination polymers constructed from a flexible V-shaped long bicarboxylic acid and different N-donor ligands have been hydrothermally synthesized through fixing the metal salts and the solvent systems. The photoluminescent properties of complexes 1−8 in solid state were studied. Interestingly, 3 exhibits highly efficient luminescent sensing for Cu{sup 2+} cations and CrO{sub 4}{sup 2-} anions, as well as detection ability for the different organic solvents and nitro explosives, in which indicates it could be utilized as a multi-responsive luminescent sensor. Furthermore, compound 3 also shows good chemical resistance to both acidity and alkalinity solutions with pH ranging from 2 to 13. Thus, multiphotofunctionality and fluorescent response to pH have been combined in the 3, which is the first example in the Zn-based hybrid materials.« less

Comparison of the efficacy of propofol and metoclopramide in preventing postoperative nausea and vomiting after middle ear surgery.

PubMed

Unal, Yusuf; Ozsoylar, Ozgür; Arslan, Mustafa; Sarigüney, Damla; Akçabay, Mehmet

2009-06-01

To compare the administration of sub hypnotic dose of propofol with metoclopramide and placebo in prevention of postoperative nausea and vomiting (PONV) after middle ear surgery. This clinical research was performed in the Faculty of Medicine, Gazi University, Besevler, Ankara, Turkey, between December 2004 and October 2005. Following approval by the hospital ethics committee, 60 adult patients scheduled for a middle ear operation were randomly assigned into 3 groups. The patients in group P received 0.5 mg x kg(-1) propofol; in group M, 0.2 mg x kg(-1) metoclopramide, and in group C, 0.9% saline solution. The number of patients suffering from nausea and vomiting at 0-4, 4-12, and 12-24 hours postoperatively, and additional use of antiemetics was recorded. Comparisons of the data showed that at 0-4th hours, the incidence of vomiting was 25% in group P, 40% in group M, and 75% in group C. The incidence rate of group P was significantly lower than that of group C (p=0.002), and the rate of antiemetics use in group C was higher than that in group P (p=0.028). The Nausea Vomiting Scale scores of group C were also significantly higher than those of group P (p=0.005). There were no significant differences between the values at 4-12 and 12-24 hours. The administration of a sub hypnotic dose of propofol at the end of surgery was found to be at least as effective as metoclopramide in preventing PONV in the early postoperative period in adult patients undergoing middle ear surgery.

Structure, upconversion photoluminescence, and dielectric properties of Ho{sup 3+}- and Yb{sup 3+}-codoped tetragonal tungsten bronze Sr{sub 4}La{sub 2}Ti{sub 4}Nb{sub 6}O{sub 30}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, T., E-mail: weitong.nju@gmail.com; Li, C.P.; Zhou, Q.J.

2015-04-15

Highlights: • TTB-type SLTN: Ho-Ybx with space group P4/mbm was determined. • UC photoluminescence of SLTN: Ho-Ybx ceramics was first reported. • Bright UC green emission was observed at room temperature. • Two-photon energy transfer process was confirmed for the UC processes. • Temperature stability of dielectric permittivity was improved for SLTN: Ho-Ybx. - Abstract: Ho{sup 3+}- and Yb{sup 3+}-codoped Sr{sub 4}La{sub 2}Ti{sub 4}Nb{sub 6}O{sub 30} (Sr{sub 4}La{sub 1.94–x}Ho{sub 0.06}Yb{sub x}Ti{sub 4}Nb{sub 6}O{sub 30}, abbreviated as SLTN: Ho-Ybx) ceramics have been synthesized, and their structural, up-conversion (UC) photoluminescence, and dielectric properties have been carefully investigated. Through Rietveld structural refinement, SLTN:more » Ho-Ybx samples are determined as single tetragonal tungsten bronze (TTB) phase with space group P4/mbm in which larger Sr{sup 2+} ions fill the A{sub 2}-sites, relative smaller La{sup 3+}, Ho{sup 3+}, and Yb{sup 3+} ions occupy the A{sub 1}-sites, while Ti{sup 4+} and Nb{sup 4+} ions fill the B-sites. Under 980 nm near infrared (NIR) excitation, bright UC green emission, relatively weak red and near-infrared (NIR) emissions, originating from {sup 5}F{sub 4}/{sup 5}S{sub 2} → {sup 5}I{sub 8}, {sup 5}F{sub 5} → {sup 5}I{sub 8}, and {sup 5}F{sub 4}/{sup 5}S{sub 2} → {sup 5}I{sub 7} transitions of Ho{sup 3+} ions, are confirmed for SLTN: Ho-Ybx. Two-photon energy transfer process is proved through pumping laser power dependence of emission intensity measurement. Furthermore, the influence of Ho{sup 3+}- and Yb{sup 3+}- ions on the dielectric properties of SLTN: Ho-Ybx is also investigated and the temperature stability of dielectric permittivity is improved.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buras, Andrzej J.; /Munich, Tech. U.; Gorbahn, Martin

The authors calculate the complete next-to-next-to-leading order QCD corrections to the charm contribution of the rare decay K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}. They encounter several new features, which were absent in lower orders. They discuss them in detail and present the results for the two-loop matching conditions of the Wilson coefficients, the three-loop anomalous dimensions, and the two-loop matrix elements of the relevant operators that enter the next-to-next-to-leading order renormalization group analysis of the Z-penguin and the electroweak box contribution. The inclusion of the next-to-next-to-leading order QCD corrections leads to a significant reduction of the theoretical uncertainty from {+-}more » 9.8% down to {+-} 2.4% in the relevant parameter P{sub c}(X), implying the leftover scale uncertainties in {Beta}(K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}) and in the determination of |V{sub td}|, sin 2{beta}, and {gamma} from the K {yields} {pi}{nu}{bar {nu}} system to be {+-} 1.3%, {+-} 1.0%, {+-} 0.006, and {+-} 1.2{sup o}, respectively. For the charm quark {ovr MS} mass m{sub c}(m{sub c}) = (1.30 {+-} 0.05) GeV and |V{sub us}| = 0.2248 the next-to-leading order value P{sub c}(X) = 0.37 {+-} 0.06 is modified to P{sub c}(X) = 0.38 {+-} 0.04 at the next-to-next-to-leading order level with the latter error fully dominated by the uncertainty in m{sub c}(m{sub c}). They present tables for P{sub c}(X) as a function of m{sub c}(m{sub c}) and {alpha}{sub s}(M{sub z}) and a very accurate analytic formula that summarizes these two dependences as well as the dominant theoretical uncertainties. Adding the recently calculated long-distance contributions they find {Beta}(K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}) = (8.0 {+-} 1.1) x 10{sup -11} with the present uncertainties in m{sub c}(m{sub c}) and the Cabibbo-Kobayashi-Maskawa elements being the dominant individual sources in the quoted error. They also emphasize that improved calculations of the long-distance contributions to K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}} and of the isospin breaking corrections in the evaluation of the weak current matrix elements from K{sup +} {yields} {pi}{sup 0}e{sup +}{nu} would be valuable in order to increase the potential of the two golden K {yields} {pi}{nu}{bar {nu}} decays in the search for new physics.« less

Crystallization of the Nonameric Small Terminase Subunit of Bacteriophage P22

DOE Office of Scientific and Technical Information (OSTI.GOV)

A Roy; A Bhardwaj; G Cingolani

2011-12-31

The packaging of viral genomes into preformed empty procapsids is powered by an ATP-dependent genome-translocating motor. This molecular machine is formed by a heterodimer consisting of large terminase (L-terminase) and small terminase (S-terminase) subunits, which is assembled into a complex of unknown stoichiometry, and a dodecameric portal protein. There is considerable confusion in the literature regarding the biologically relevant oligomeric state of terminases, which, like portal proteins, form ring-like structures. The number of subunits in a hollow oligomeric protein defines the internal diameter of the central channel and the ability to fit DNA inside. Thus, knowledge of the exact stoichiometrymore » of terminases is critical to decipher the mechanisms of terminase-dependent DNA translocation. Here, the gene encoding bacteriophage P22 S-terminase in Escherichia coli has been overexpressed and the protein purified under native conditions. In the absence of detergents and/or denaturants that may cause disassembly of the native oligomer and formation of aberrant rings, it was found that P22 S-terminase assembles into a concentration-independent nonamer of {approx}168 kDa. Nonameric S-terminase was crystallized in two different crystal forms at neutral pH. Crystal form I belonged to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 144.2, b = 144.2, c = 145.3 {angstrom}, and diffracted to 3.0 {angstrom} resolution. Crystal form II belonged to space group P2{sub 1}, with unit-cell parameters a = 76.48, b = 100.9, c = 89.95 {angstrom}, {beta} = 93.73{sup o}, and diffracted to 1.75 {angstrom} resolution. Preliminary crystallographic analysis of crystal form II confirms that the S-terminase crystals contain a nonamer in the asymmetric unit and are suitable for high-resolution structure determination.« less

Crystallization of the Nonameric Small Terminase Subunit of bacteriophage P22

DOE Office of Scientific and Technical Information (OSTI.GOV)

A Roy; A Bhardwaj; G Cingoloni

2011-12-31

The packaging of viral genomes into preformed empty procapsids is powered by an ATP-dependent genome-translocating motor. This molecular machine is formed by a heterodimer consisting of large terminase (L-terminase) and small terminase (S-terminase) subunits, which is assembled into a complex of unknown stoichiometry, and a dodecameric portal protein. There is considerable confusion in the literature regarding the biologically relevant oligomeric state of terminases, which, like portal proteins, form ring-like structures. The number of subunits in a hollow oligomeric protein defines the internal diameter of the central channel and the ability to fit DNA inside. Thus, knowledge of the exact stoichiometrymore » of terminases is critical to decipher the mechanisms of terminase-dependent DNA translocation. Here, the gene encoding bacteriophage P22 S-terminase in Escherichia coli has been overexpressed and the protein purified under native conditions. In the absence of detergents and/or denaturants that may cause disassembly of the native oligomer and formation of aberrant rings, it was found that P22 S-terminase assembles into a concentration-independent nonamer of {approx}168 kDa. Nonameric S-terminase was crystallized in two different crystal forms at neutral pH. Crystal form I belonged to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 144.2, b = 144.2, c = 145.3 {angstrom}, and diffracted to 3.0 {angstrom} resolution. Crystal form II belonged to space group P2{sub 1}, with unit-cell parameters a = 76.48, b = 100.9, c = 89.95 {angstrom}, {beta} = 93.73{sup o}, and diffracted to 1.75 {angstrom} resolution. Preliminary crystallographic analysis of crystal form II confirms that the S-terminase crystals contain a nonamer in the asymmetric unit and are suitable for high-resolution structure determination.« less

A comparison of patient pain and visual outcome using topical anesthesia versus regional anesthesia during cataract surgery.

PubMed

Hosoda, Yoshikatsu; Kuriyama, Shoji; Jingami, Yoko; Hattori, Hidetsugu; Hayashi, Hisako; Matsumoto, Miho

2016-01-01

The purpose of this study was to compare the level of patient pain during the phacoemulsification and implantation of foldable intraocular lenses while under topical, intracameral, or sub-Tenon lidocaine. This was a retrospective study. Three hundred and one eyes subjected to cataract surgery were included in this study. All eyes underwent phacoemulsification surgery and intraocular lens implantation using topical, sub-Tenon, or intracameral anesthesia. The topical group received 4% lidocaine drops, and the intracameral group received a 0.1-0.2 cc infusion of 1% preservative-free lidocaine into the anterior chamber through the side port combined with topical drops of lidocaine. The sub-Tenon group received 2% lidocaine. Best-corrected visual acuity, corneal endothelial cell loss, and intraoperative pain level were evaluated. Pain level was assessed on a visual analog scale (range 0-2). There were no significant differences in visual outcome and corneal endothelial cell loss between the three groups. The mean pain score in the sub-Tenon group was significantly lower than that in the topical and intracameral groups (P=0.0009 and P=0.0055, respectively). In 250 eyes without high myopia (< -6D), there were no significant differences in mean pain score between the sub-Tenon and intracameral groups (P=0.1417). No additional anesthesia was required in all groups. Intracameral lidocaine provides sufficient pain suppressive effects in eyes without high myopia, while sub-Tenon anesthesia is better for cataract surgery in eyes with high myopia.

Evidence for two distinct intracellular pools of inorganic sulfate in Penicillium notatum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunter, D.R.; Segel, I.H.

1985-06-01

A strain of Penicillium notatum unable to metabolize inorganic sulfate can accumulate sulfate internally to an apparent equilibrium concentration 10/sup 5/ times greater than that remaining in the medium. The apparent K/sub eq/ is near constant at all initial external sulfate concentrations below that which would eventually exceed the internal capacity of the cells. Under equilibrium conditions of zero net flux, external /sup 35/SO/sub 4//sup 2 -/ exchanges with internal, unlabeled SO/sub 4//sup 2 -/ at a rate consistent with the kinetic constants with the sulfate transport system. Efflux experiments demonstrated that sulfate occupies two distinct intracellular pools. Pool 1more » is characterized by the rapid release of /sup 35/SO/sub 4//sup 2 -/ when the suspension of preloaded cells is adjusted to 10 mM azide at pH 8.4 (t/sub 1/2/, 0.38 min). /sup 35/SO/sub 4//sup 2 -/ in pool 1 also rapidly exchanges with unlabeled medium sulfate. Pool 2 is characterized by the slow release of /sup 35/SO/sub 4//sup 2 -/ induced by azide at pH 8.4 or unlabeled sulfate (t/sub 1/2/, 32 to 49 min). Early in the /sup 35/SO/sub 4//sup 2 -/ accumulation process, up to 78% of the total transported substrate is found in pool 1. At equilibrium, pool 1 accounts for only about 2% of the total accumulated /sup 35/SO/sub 4//sup 2 -/. Monensin (33 ..mu..m) accelerates the transfer of /sup 35/SO/sub 4//sup 2 -/ from pool 1 to pool 2. Valinomycin (0.2 ..mu..M) and tetraphynylboron/sup -/ (1 mM) retard the transfer of /sup 35/SO/sub 4//sup 2 -/ from pool 1 to pool 2. Pool 2 may reside in a vacuole or other intracellular organelle. A model for the transfer of sulfate from pool 1 to pool 2 is presented.« less

Expression, purification, crystallization, data collection and preliminary biochemical characterization of methicillin-resistant Staphylococcus aureus Sar2028, an aspartate/tyrosine/phenylalanine pyridoxal-5′-phosphate-dependent aminotransferase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seetharamappa, Jaldappagari; Department of Chemistry, Karnatak University, Pavate Nagar, Dharwad 580 003, Karnataka State; Oke, Muse

2007-05-01

As part of work on S. aureus, the crystallization of Sar2028, a protein that is upregulated in MRSA, is reported. Sar2028, an aspartate/tyrosine/phenylalanine pyridoxal-5′-phosphate-dependent aminotransferase with a molecular weight of 48 168 Da, was overexpressed in methicillin-resistant Staphylococcus aureus compared with a methicillin-sensitive strain. The protein was expressed in Escherichia coli, purified and crystallized. The protein crystallized in a primitive orthorhombic Laue group with unit-cell parameters a = 83.6, b = 91.3, c = 106.0 Å, α = β = γ = 90°. Analysis of the systematic absences along the three principal axes indicated the space group to be P2{submore » 1}2{sub 1}2{sub 1}. A complete data set was collected to 2.5 Å resolution.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakho, I., E-mail: aminafatima_sakho@yahoo.fr

Energy positions and quantum defects of the 4s{sup 2}4p{sup 4} ({sup 1}D{sub 2},{sup 1}S{sub 0}) ns, nd Rydberg series originating from the 4s{sup 2}4p{sup 52}P{sub 3/2}{sup ∘} ground state and from the 4s{sup 2}4p{sup 52}P{sub 1/2}{sup ∘} metastable state of Kr{sup +} are reported. Calculations are performed using the Screening Constant by Unit Nuclear Charge (SCUNC) method. The results obtained are in suitable agreement with recent experimental data from the combined ASTRID merged-beam set up and Fourier Transform Ion Cyclotron Resonance device (Bizau et al., 2011), ALS measurements (Hinojosa et al., 2012), and multi-channel R-matrix eigenphase derivative calculations (McLaughlin andmore » Balance, 2012). In addition, analysis of the 4s{sup 2}4p{sup 4}({sup 1}D{sub 2})nd and the 4s{sup 2}4p{sup 4}({sup 1}S{sub 0})nd resonances is given via the SCUNC procedure. The excellent results obtained from our work point out that the SCUNC formalism may be used to confirm the results of the analysis from the standard quantum-defect expansion formulas. Eventual errors occurring in the analysis can then be automatically detected and corrected via the SCUNC procedure.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turaka, Aruna; Buyyounouski, Mark K., E-mail: mark.buyyounouski@fccc.edu; Hanlon, Alexandra L.

Purpose: To correlate tumor oxygenation status with long-term biochemical outcome after prostate brachytherapy. Methods and Materials: Custom-made Eppendorf PO{sub 2} microelectrodes were used to obtain PO{sub 2} measurements from the prostate (P), focused on positive biopsy locations, and normal muscle tissue (M), as a control. A total of 11,516 measurements were obtained in 57 men with localized prostate cancer immediately before prostate brachytherapy was given. The Eppendorf histograms provided the median PO{sub 2}, mean PO{sub 2}, and % <5 mm Hg or <10 mm Hg. Biochemical failure (BF) was defined using both the former American Society of Therapeutic Radiation Oncologymore » (ASTRO) (three consecutive raises) and the current Phoenix (prostate-specific antigen nadir + 2 ng/mL) definitions. A Cox proportional hazards regression model evaluated the influence of hypoxia using the P/M mean PO{sub 2} ratio on BF. Results: With a median follow-up time of 8 years, 12 men had ASTRO BF and 8 had Phoenix BF. On multivariate analysis, P/M PO{sub 2} ratio <0.10 emerged as the only significant predictor of ASTRO BF (p = 0.043). Hormonal therapy (p = 0.015) and P/M PO{sub 2} ratio <0.10 (p = 0.046) emerged as the only independent predictors of the Phoenix BF. Kaplan-Meier freedom from BF for P/M ratio <0.10 vs. {>=}0.10 at 8 years for ASTRO BF was 46% vs. 78% (p = 0.03) and for the Phoenix BF was 66% vs. 83% (p = 0.02). Conclusions: Hypoxia in prostate cancer (low mean P/M PO{sub 2} ratio) significantly predicts for poor long-term biochemical outcome, suggesting that novel hypoxic strategies should be investigated.« less

Synthesis and characterization of novel barium iron phosphates: Insight into new structure types tailored by hydrogen atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Li-Zhi, E-mail: tslz2007@163.com; Sun, Wei, E-mail: 421221789@qq.com; Ren, Wei-Jian, E-mail: 935428502@qq.com

A significant gap in our knowledge of phosphate crystal chemistry is the lack of understanding of what controls the depolymerization of [PO{sub 4}] tetrahedra. A new route using phosphoric acid without any added water at 240 °C has been developed to synthesize two new compounds Ba{sub 2}Fe{sub 2}[H(PO{sub 3}OH){sub 2}][H(P{sub 2}O{sub 7}){sub 2}] and Ba{sub 2}Fe[H(P{sub 2}O{sub 7}){sub 2}], as well as a new polymorph β-BaFe{sub 2}(P{sub 2}O{sub 7}){sub 2} from annealing the former at ≥500 °C. Structural characterizations show that Ba{sub 2}Fe{sub 2}[H(PO{sub 3}OH){sub 2}][H(P{sub 2}O{sub 7}){sub 2}] features a novel 2D {sup 2}{sub ∞}([Fe{sub 2}[H(PO{sub 3}OH){sub 2}][H(P{sub 2}O{submore » 7}){sub 2}

THE INFLUENCE OF METAL IONS ON THE ADSORPTION OF PHOSPHONATES ONTO GOETHITE. (R826376)

EPA Science Inventory

Mono- and polyphosphonates, which contain R₃CP(O)(OH)₂
functional groups, are used in an increasing variety of industrial and household
applications including cooling water systems, oil production, textile
production, and detergents. The main ...

Growth and characterization of highly tensile strained Ge{sub 1−x}Sn{sub x} formed on relaxed In{sub y}Ga{sub 1−y}P buffer layers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Wei; D'Costa, Vijay Richard; Dong, Yuan

2016-03-28

Ge{sub 0.94}Sn{sub 0.06} films with high tensile strain were grown on strain-relaxed In{sub y}Ga{sub 1−y}P virtual substrates using solid-source molecular beam epitaxy. The in-plane tensile strain in the Ge{sub 0.94}Sn{sub 0.06} film was varied by changing the In mole fraction in In{sub x}Ga{sub 1−x}P buffer layer. The tensile strained Ge{sub 0.94}Sn{sub 0.06} films were investigated by transmission electron microscopy, x-ray diffraction, and Raman spectroscopy. An in-plane tensile strain of up to 1% in the Ge{sub 0.94}Sn{sub 0.06} was measured, which is much higher than that achieved using other buffer systems. Controlled thermal anneal experiment demonstrated that the strain was notmore » relaxed for temperatures up to 500 °C. The band alignment of the tensile strained Ge{sub 0.94}Sn{sub 0.06} on In{sub 0.77}Ga{sub 0.23}P was obtained by high resolution x-ray photoelectron spectroscopy. The Ge{sub 0.94}Sn{sub 0.06}/In{sub 0.77}Ga{sub 0.23}P interface was found to be of the type I band alignment, with a valence band offset of 0.31 ± 0.12 eV and a conduction band offset of 0.74 ± 0.12 eV.« less

Vapor pressures of 1,3-dialkylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids with long alkyl chains

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rocha, Marisa A. A., E-mail: lbsantos@fc.up.pt, E-mail: marisa.alexandra.rocha@gmail.com; Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Den Dolech 2, 5612 AZ Eindhoven; Coutinho, João A. P.

2014-10-07

This work presents the vapor pressure at several temperatures for the 1,3-dialkylimidazolium bis(trifluoromethylsulfonyl)imide series, [C{sub N/2}C{sub N/2}im][NTf{sub 2}] (N = 14, 16, 18, and 20), measured by a Knudsen effusion method combined with a quartz crystal microbalance. The thermodynamic properties of vaporization of the ionic liquids under study are analysed together with the results obtained previously for the shorter alkyl chain length [C{sub N/2}C{sub N/2}im][NTf{sub 2}] (N = 2, 4, 6, 8, 10, and 12), in order to evaluate the effect of the alkyl side chains of the cation and to get additional insights concerning the nanostructuration of ionic liquids.more » The symmetry effect is explored, based on the comparison with the asymmetric imidazolium based ionic liquids, [C{sub N-1}C{sub 1}im][NTf{sub 2}]. A trend shift on the thermodynamic properties of vaporization along the alkyl side chains of the extended symmetric ionic liquids, around [C{sub 6}C{sub 6}im][NTf{sub 2}], was detected. An intensification of the odd-even effect was observed starting from [C{sub 6}C{sub 6}im][NTf{sub 2}], with higher enthalpies and entropies of vaporization for the odd numbered ionic liquids, [C{sub 7}C{sub 7}im][NTf{sub 2}] and [C{sub 9}C{sub 9}im][NTf{sub 2}]. Similar, but less pronounced, odd-even effect was found for the symmetric ionic liquids with lower alkyl side chains length, [C{sub N/2}C{sub N/2}im][NTf{sub 2}] (with N = 4, 6, 8, 10, and 12). This effect is related with the predominant orientation of the terminal methyl group of the alkyl chain to the imidazolium ring and their influence in the cation-anion interaction. The same Critical Alkyl length at the hexyl, (C{sub 6}C{sub 1}and C{sub 6}C{sub 6}) was found for both asymmetric and symmetric series indicating that the nanostructuration of the ionic liquids is related with alkyl chain length.« less

Synthesis and magnetic structure of the layered manganese oxide selenide Sr{sub 2}MnO{sub 2}Ag{sub 1.5}Se{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blandy, Jack N.; Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE; Boskovic, Jelena C.

The synthesis of a high-purity sample of the layered oxide selenide Sr{sub 2}MnO{sub 2}Ag{sub 1.5}Se{sub 2} is reported. At ambient temperature it crystallises in the space group I4/mmm with two formula units in the unit cell and lattice parameters a=4.08771(1) Å, c=19.13087(8) Å. The compound displays mixed-valent manganese in a formal oxidation state close to +2.5 and powder neutron diffraction measurements reveal that below the Néel temperature of 63(1) K this results in an antiferromagnetic structure which may be described as A-type, modelled in the magnetic space group P{sub I}4/mnc (128.410 in the Belov, Neronova and Smirnova (BNS) scheme) inmore » which localised Mn moments of 3.99(2) μ{sub B} are arranged in ferromagnetic layers which are coupled antiferromagnetically. In contrast to the isostructural compound Sr{sub 2}MnO{sub 2}Cu{sub 1.5}S{sub 2}, Sr{sub 2}MnO{sub 2}Ag{sub 1.5}Se{sub 2} does not display long range ordering of coinage metal ions and vacancies, nor may significant amounts of the coinage metal readily be deintercalated using soft chemical methods. - Graphical abstract: Sr{sub 2}MnO{sub 2}Ag{sub 1.5}Se{sub 2} containing mixed valent Mn ions undergoes magnetic ordering with ferromagnetic coupling within MnO{sub 2} sheets and antiferromagnetic coupling between MnO{sub 2} sheets. - Highlights: • High purity sample of Sr{sub 2}MnO{sub 2}Ag{sub 1.5}Se{sub 2} obtained. • Magnetic structure determined. • Compared with related mixed-valent manganite oxide chalcogenides.« less

Longitudinal spin Seebeck effect in Nd{sub 2}BiFe{sub 5−x}Ga{sub x}O{sub 12} prepared on gadolinium gallium garnet (001) by metal organic decomposition method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asada, H., E-mail: asada@yamaguchi-u.ac.jp; Kuwahara, A.; Sakata, N.

2015-05-07

Nd{sub 2}BiFe{sub 5−x}Ga{sub x}O{sub 12} thin films with the Ga composition x = 0, 0.5, and 1.0 are prepared on (001) oriented gadolinium gallium garnet substrates by a metal organic decomposition method. Only (001) peaks are observed in x-ray diffraction patterns for all the films, suggesting that the highly oriented Nd{sub 2}BiFe{sub 5−x}Ga{sub x}O{sub 12} thin films were formed. Increasing Ga composition, the saturation magnetization decreases, and the perpendicular easy axis is enhanced due to the decrease of the shape anisotropy. Longitudinal spin Seebeck effects (LSSEs) in Nd{sub 2}BiFe{sub 5−x}Ga{sub x}O{sub 12} thin films with a Pt layer of 10 nm in thicknessmore » were investigated. Magnetic field dependence of the thermoelectric voltage caused by the LSSE in Nd{sub 2}BiFe{sub 5−x}Ga{sub x}O{sub 12} films indicates the hysteresis loop with the small coercivity reflecting the magnetization curve. The decrease of LSSE voltage in Nd{sub 2}BiFe{sub 5−x}Ga{sub x}O{sub 12} is clearly observed with the decrease of Fe composition.« less

Luminescence of phosphorus containing oxide materials: Crystalline SiO{sub 2}‐P and 3P{sub 2}O{sub 5}⋅7SiO{sub 2}; CaO⋅P{sub 2}O{sub 5}; SrO⋅P{sub 2}O{sub 5} glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trukhin, A. N., E-mail: truhins@cfi.lu.lv; Smits, K., E-mail: truhins@cfi.lu.lv; Jansons, J., E-mail: truhins@cfi.lu.lv

2014-10-21

Luminescence of phosphate glasses such as CaO⋅P{sub 2}O{sub 5} and SrO⋅P{sub 2}O{sub 5} is compared with that of phosphorus doped crystalline α-quartz and phosphosilicate glass with content 3P{sub 2}O{sub 5}⋅7SiO{sub 2}. Water and OH groups are found by IR spectra in these materials. The spectrum of luminescence contains many bands in the range 1.5 - 5.5 eV. The luminescence bands in UV range at 4.5-5 eV are similar in those materials. Decay duration in exponential approximation manifests a time constant about 37 ns. Also a component in μs range was detected. PL band of μs component is shifted to lowmore » energy with respect to that of ∼37 ns component. This shift is about 0.6 eV. It is explained as singlet-triplet splitting of excited state. Below 14 K increase of luminescence kinetics duration in μs range was observed and it was ascribed to zero magnetic field splitting of triplet excited state of the center. Yellow-red luminescence was induced by irradiation in phosphorus doped crystalline α-quartz, phosphosilicate glasses. The yellowl uminescence contains two bands at 600 and 740 nm. Their decay is similar under 193 nm laser and may be fitted with the first order fractal kinetics or stretched exponent. Thermally stimulated luminescence contains only band at 600 nm. The 248 nm laser excites luminescence at 740 nm according to intra center process with decay time constant about 4 ms at 9 K. Both type of luminescence UV and yellow were ascribed to different defects containing phosphorus. P-doped α-quartz sample heated to 550 co become opalescent. Ir spectra related to water and OH groups are changed. Photoluminescence intensity of all three bands, UV (250 nm), yellow (600 nm) and red (740 nm) strongly diminished and disappeared after heating to 660 C°. Radiation induced red luminescence of non-bridging oxygen luminescence center (NBO) appeared in crystal after heat treatment. We had observed a crystalline version of this center (l. Skuja et al, Nuclear Instruments and Methods in Physics Research B 286,159-168 (2012)). Effect of heat treatment explained as sedimentation of phosphorus in some state. Keeping of treated sample at 450-500 C° leads to partial revival of ability to create yellow luminescence center under irradiation.« less

Preparation and characterization of magnetic CsH{sub 2}PW{sub 12}O{sub 40}/Fe–SiO{sub 2} nanocatalysts for biodiesel production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feyzi, Mostafa, E-mail: Dalahoo2011@yahoo.com; Nanoscience and Nanotechnology Research Center; Nourozi, Leila

Graphical abstract: In this study, a series of magnetic CsH{sub 2}PW{sub 12}O{sub 40}/Fe–SiO{sub 2} nanocatalysts were prepared and tested for biodiesel production. The best operational conditions were CH3OH/oil = 12/1 at 60 °C with mechanical stirring, the biodiesel yield reaches to 81% in 4 h. Also notably, recovery of the catalyst can be achieved easily with the help of an external magnet with no need for expensive ultracentrifugation. - Highlights: • Effects of preparation conditions for biodiesel production were studied. • The CsH{sub 2}PW{sub 12}O{sub 40}/Fe–SiO{sub 2} catalyst is efficient catalyst for biodiesel production. • The reaction conditions were foundmore » methanol/oil = 12/1, T = 60 °C. - Abstract: The magnetic CsH{sub 2}PW{sub 12}O{sub 40}/Fe–SiO{sub 2} nanocatalysts were prepared via combination of sol–gel and impregnation methods. The effects of different H{sub 3}PW{sub 12}O{sub 40}/(Fe–SiO{sub 2}) weight percentage, loading of Cs as a promotor and calcination conditions on the catalytic performance has been studied. It was found that the catalyst with H{sub 3}PW{sub 12}O{sub 40}/Fe–SiO{sub 2} = 4 wt.% and Cs = 2 wt.% is an optimal catalyst for biodiesel production. The activity of optimal catalyst was studied in different operational conditions. The best operational conditions were CH{sub 3}OH/oil = 12/1 at 60 °C with mechanical stirring rate of 500 rpm and the biodiesel yield reaches to 81% in 4 h. Characterization of catalysts was carried out by using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), N{sub 2} adsorption–desorption measurements methods, Thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC)« less

Hydrogen interaction kinetics of Ge dangling bonds at the Si{sub 0.25}Ge{sub 0.75}/SiO{sub 2} interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stesmans, A., E-mail: andre.stesmans@fys.kuleuven.be; Nguyen Hoang, T.; Afanas'ev, V. V.

2014-07-28

The hydrogen interaction kinetics of the GeP{sub b1} defect, previously identified by electron spin resonance (ESR) as an interfacial Ge dangling bond (DB) defect occurring in densities ∼7 × 10{sup 12} cm{sup −2} at the SiGe/SiO{sub 2} interfaces of condensation grown (100)Si/a-SiO{sub 2}/Ge{sub 0.75}Si{sub 0.25}/a-SiO{sub 2} structures, has been studied as function of temperature. This has been carried out, both in the isothermal and isochronal mode, through defect monitoring by capacitance-voltage measurements in conjunction with ESR probing, where it has previously been demonstrated the defects to operate as negative charge traps. The work entails a full interaction cycle study, comprised of analysis ofmore » both defect passivation (pictured as GeP{sub b1}-H formation) in molecular hydrogen (∼1 atm) and reactivation (GeP{sub b1}-H dissociation) in vacuum. It is found that both processes can be suitably described separately by the generalized simple thermal (GST) model, embodying a first order interaction kinetics description based on the basic chemical reactions GeP{sub b1} + H{sub 2} → GeP{sub b1}H + H and GeP{sub b1}H → GeP{sub b1} + H, which are found to be characterized by the average activation energies E{sub f} = 1.44 ± 0.04 eV and E{sub d} = 2.23 ± 0.04 eV, and attendant, assumedly Gaussian, spreads σE{sub f} = 0.20 ± 0.02 eV and σE{sub d} = 0.15 ± 0.02 eV, respectively. The substantial spreads refer to enhanced interfacial disorder. Combination of the separately inferred kinetic parameters for passivation and dissociation results in the unified realistic GST description that incorporates the simultaneous competing action of passivation and dissociation, and which is found to excellently account for the full cycle data. For process times t{sub a} ∼ 35 min, it is found that even for the optimum treatment temperature ∼380 °C, only ∼60% of the GeP{sub b1} system can be electrically silenced, still far remote from device grade level. This ineffectiveness is concluded, for the major part, to be a direct consequence of the excessive spreads in the activation energies, ∼2–3 times larger than for the Si DB P{sub b} defects at the standard thermal (111)Si/SiO{sub 2} interface which may be easily passivated to device grade levels, strengthened by the reduced difference between the average E{sub f} and E{sub d} values. Exploring the guidelines of the GST model indicates that passivation can be improved by decreasing T{sub an} and attendant enlarging of t{sub a}, however, at best still leaving ∼2% defects unpassivated even for unrealistically extended anneal times. The average dissociation energy E{sub d} ∼ 2.23 eV, concluded as representing the GeP{sub b1}-H bond strength, is found to be smaller than the SiP{sub b}-H one, characterized by E{sub d} ∼ 2.83 eV. An energy deficiency is encountered regarding the energy sum rule inherent to the GST-model, the origin of which is substantiated to lie with a more complex nature of the forward passivation process than basically depicted in the GST model. The results are discussed within the context of theoretical considerations on the passivation of interfacial Ge DBs by hydrogen.« less

NMR Spectroscopy and Structural Characterization of Dithiophosphinates Relevant to Minor Actinide Extraction Processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scott R. Daly; Kevin S. Boland; John R. Klaehn

2012-02-01

Synthetic routes to alkyl and aryl substituted dithiophosphinate salts that contain non-coordinating PPh{sub 4}{sup 1+} counter cations are reported. In general, these compounds can be prepared via a multi-step procedure that starts with reacting secondary phosphines, i.e. HPR{sub 2}, with two equivalents elemental S. This transformation proceeds in two steps - first oxidation of the phosphine and second insertion of S into the H-P bond - and has been used to synthesize a series of dithiophoshinic acids, which were fully characterized, namely HS{sub 2}P(p-CF{sub 3}C{sub 6}H{sub 4}){sub 2}, HS{sub 2}P(m-CF{sub 3}C{sub 6}H{sub 4}){sub 2}, HS{sub 2}P(o-MeC{sub 6}H{sub 4}){sub 2}, andmore » HS{sub 2}P(o-MeOC{sub 6}H{sub 4}){sub 2}. Although the insertion step was found to be much slower than the oxidation reaction, the formation of (NH{sub 4})S{sub 2}PR{sub 2} from HPSR{sub 2} occurs almost instantaneous upon addition of NH{sub 4}OH. Subsequent cation exchange reactions proceed readily with PPh{sub 4}Cl in water, under air, and at ambient conditions to provide analytically pure samples of [PPh{sub 4}][S{sub 2}PR{sub 2}] (R = p-CF{sub 3}C{sub 6}H{sub 4}, m-CF{sub 3}C{sub 6}H{sub 4}, o-CF{sub 3}C{sub 6}H{sub 4}, o-MeC{sub 6}H{sub 4}, o-MeOC{sub 6}H{sub 4}, Ph, and Me, 1b-7b, respectively), which were characterized by elemental analysis, multinuclear NMR, and IR spectroscopy. In addition the S{sub 2}PMe{sub 2}{sup 1-}, S{sub 2}PPh{sub 2}{sup 1-}, and dithiophosphinates with ortho-substituted arene rings were characterized by X-ray crystallography. Structural analysis show that, as opposed to the acids which have short P=S double bonds and long P-SH single bonds, the metric parameters for the S atoms in S{sub 2}PR{sub 2}{sup 1-} are equivalent. In addition, the presence of large non-coordinating PPh{sub 4}{sup 1+} cations guard against intermolecular P-S {hor_ellipsis} X interactions and insure that the P-S bond is isolated. Overall, this synthetic procedure provides high-purity S{sub 2}PR{sub 2}{sup 1-} compounds necessary for subsequent spectroscopic and theoretical studies.« less

Synthesis and crystal structure of a novel pentaborate, Na{sub 3}ZnB{sub 5}O{sub 10}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Xuean; Li Ming; Chang Xinan

A novel ternary borate, trisodium zinc pentaborate, Na{sub 3}ZnB{sub 5}O{sub 10}, has been prepared by solid-state reaction at temperature below 750deg. C. The single-crystal X-ray structural analysis showed that Na{sub 3}ZnB{sub 5}O{sub 10} crystallizes in the monoclinic space group P2{sub 1}/n with a=6.6725(7)A, b=18.1730(10)A, c=7.8656(9)A, {beta}=114.604(6){sup o}, Z=4. It represents a new structure type in which double ring [B{sub 5}O{sub 10}]{sup 5-} building units are bridged by ZnO{sub 4} tetrahedra through common O atoms to form a two-dimensional {sub {approx}}{sup 2}[ZnB{sub 5}O{sub 10}]{sup 3-}-layer that affords one-dimensional channels running parallel to the [101] direction. Symmetry-center related {sub {approx}}{sup 2}[ZnB{sub 5}O{submore » 10}]{sup 3-} layers are stacked along the b-axis, with the interlayer void spaces and intralayer open channels filled by Na{sup +} cations to balance charge. The IR spectrum further confirms the presence of both BO{sub 3} and BO{sub 4} groups and UV-vis diffuse reflectance spectrum shows a band gap of about 3.2eV.« less

Measurements of the ground-state Lamb shift and electron-correlation effects in hydrogenlike and heliumlike uranium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lupton, J.H.; Dietrich, D.D.; Hailey, C.J.

1994-09-01

We report measurements of transition energies for highly ionized uranium. For hydrogenic uranium we have measured 102 130[plus minus]92 eV for the 2[ital p][sub 3/2-]1[ital s][sub 1/2] transition. This measurement is sensitive to the 1[ital s] Lamb shift, probing the electron self-energy in high-field QED. In addition, we have measured the (1[ital s]2[ital p])[sup 1][ital P][sub 1],[sup 3][ital P][sub 2-](1[ital s][sup 2])[sup 1][ital S][sub 0] transition in heliumlike uranium as 100 598[plus minus]111 eV, probing relativistic electron-electron correlation effects. Both measurements were obtained with a Doppler spectrometer, a proven technique which we have adapted to the field of high-[ital Z]more » precision atomic transition-energy measurements. These measurements demonstrate the potential of this technique to attain [similar to]1 eV uncertainties.« less

Crystallization and preliminary crystallographic studies of Hyp-1, a St John’s wort protein implicated in the biosynthesis of hypericin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandes, Humberto; Konieczna, Malgorzata; Kolodziejczyk, Robert

2008-05-01

The Hyp-1 protein suggested to be a phenolic oxidative-coupling enzyme involved in the biosynthesis of hypericin, a medicinally important natural compound found in St John’s wort (H. perforatum), has been expressed, purified and prepared in single-crystal form. According to a debated hypothesis, the biosynthesis from emodin of the medicinally important natural compound hypericin is catalyzed in St John’s wort (Hypericum perforatum) by the phenolic oxidative-coupling protein Hyp-1. Recombinant St John’s wort Hyp-1 has been overexpressed in Escherichia coli and obtained in single-crystal form. The crystals belong to the orthorhombic system, space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters amore » = 37.5, b = 76.7, c = 119.8 Å, contain two protein molecules in the asymmetric unit and diffract X-rays to 1.73 Å resolution.« less

High-level Expression Purification Crystallization and Preliminary X-ray Crystallographic Studies of the Receptor Binding Domain of botulinum neurotoxin Serotype D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Y Zhang; X Gao; G Buchko

2011-12-31

Botulinum neurotoxins (BoNTs) are highly toxic proteins for humans and animals that are responsible for the deadly neuroparalytic disease botulism. Here, details of the expression and purification of the receptor-binding domain (HCR) of BoNT/D in Escherichia coli are presented. Using a codon-optimized cDNA, BoNT/D{_}HCR was expressed at a high level (150-200 mg per litre of culture) in the soluble fraction. Following a three-step purification protocol, very pure (>98%) BoNT/D{_}HCR was obtained. The recombinant BoNT/D{_}HCR was crystallized and the crystals diffracted to 1.65 {angstrom} resolution. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 60.8,more » b = 89.7, c = 93.9 {angstrom}. Preliminary crystallographic data analysis revealed the presence of one molecule in the asymmetric unit.« less

High-level expression, purification, crystallization and preliminary X-ray crystallographic studies of the receptor-binding domain of botulinum neurotoxin serotype D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Y.; Robinson, H.; Gao, X.

2010-12-01

Botulinum neurotoxins (BoNTs) are highly toxic proteins for humans and animals that are responsible for the deadly neuroparalytic disease botulism. Here, details of the expression and purification of the receptor-binding domain (HCR) of BoNT/D in Escherichia coli are presented. Using a codon-optimized cDNA, BoNT/D{_}HCR was expressed at a high level (150-200 mg per litre of culture) in the soluble fraction. Following a three-step purification protocol, very pure (>98%) BoNT/D{_}HCR was obtained. The recombinant BoNT/D{_}HCR was crystallized and the crystals diffracted to 1.65 {angstrom} resolution. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 60.8,more » b = 89.7, c = 93.9 {angstrom}. Preliminary crystallographic data analysis revealed the presence of one molecule in the asymmetric unit.« less

Purification, crystallization and preliminary X-ray analysis of the outer membrane complex HasA–HasR from Serratia marcescens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huché, Frédéric, E-mail: huche@pasteur.fr; Unité des Membranes Bactériennes, CNRS URA 2172, Département de Microbiologie Fondamentale et Médicale, Institut Pasteur, 25-28 Rue du Dr Roux, 75724 Paris CEDEX 15; Delepelaire, Philippe

2006-01-01

The expression, purification, and crystallization in space group P2{sub 1}2{sub 1}2{sub 1} of the complex HasA-HasR from S. marcescens are reported. Diffraction data have been collected and processed to 6.8 Å. Serratia marcescens is able to acquire iron using its haem-acquisition system (‘has’), which contains an outer membrane receptor HasR and a soluble haemophore HasA. After secretion, HasA binds free haem in the extracellular medium or extracts it from haemoproteins and delivers it to the receptor. Here, the crystallization of a HasA–HasR complex is reported. HasA and HasR have been overexpressed in Escherichia coli and the complex formed and crystallized.more » Small platelets and bunches of needles of dimensions 0.01 × 0.1 × 1 mm were obtained. A native data set has been collected to 6.8 Å.« less

Synthesis and characterisation of the n = 2 Ruddlesden–Popper phases Ln{sub 2}Sr(Ba)Fe{sub 2}O{sub 7} (Ln = La, Nd, Eu)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gurusinghe, Nicola N.M.; Figuera, Juand de la; Marco, José F.

2013-09-01

Graphical abstract: - Highlights: • Some Ruddlesden–Popper phases have been characterised. • Substitution on the A site influences cationic order. • The magnetic moment redirects with temperature - Abstract: A series of n = 2 Ruddlesden–Popper phases A{sub 2}B{sub 2}O{sub 7} of composition Ln{sub 2}Sr(Ba)Fe{sub 2}O{sub 7} (Ln = La, Nd, Eu) have been prepared. La{sub 2}SrFe{sub 2}O{sub 7} and La{sub 2}BaFe{sub 2}O{sub 7} crystallise in the tetragonal space group I4/mmm. The structures of Eu{sub 2}SrFe{sub 2}O{sub 7} and Nd{sub 2}SrFe{sub 2}O{sub 7} are best described in space group P4{sub 2}/mnm. Substitution on the A site with smaller lanthanide- andmore » larger alkaline metal- ions leads to enhanced cationic order in these phases and reflects increasing differences in cationic radii. All the compounds are antiferromagnetically ordered between 298 and 2 K. In La{sub 2}SrFe{sub 2}O{sub 7} the magnetic moment lies along [1 1 0] at all temperatures between 298 and 2 K whereas in La{sub 2}BaFe{sub 2}O{sub 7} the magnetic moment at 298 K lies along the crystallographic x-axis but redirects from the [1 0 0] to the [1 1 0] direction between 210 and 190 K and is retained in this direction until 2 K. In Nd{sub 2}SrFe{sub 2}O{sub 7} the magnetic moment at 298 K lies along [1 1 0] but rotates from [1 1 0] to [0 0 1] between 17 and 9 K. A series of {sup 57}Fe Mössbauer spectra recorded from La{sub 2}SrFe{sub 2}O{sub 7} between 290 and 600 K indicate a magnetic ordering temperature of T{sub N} ≥ 535 K.« less

Discrimination of putative M1 and M2 muscarinic receptor subtypes in rat brain by N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norman, A.B.; Creese, I.

1986-03-01

The EC/sub 50/ of EEDQ for the inhibition of (/sup 3/H)(-)QNB binding in vitro was approximately 3 fold lower for homogenates of hippocampus than brainstem (containing predominantly putative M/sub 1/ and M/sub 2/ muscarinic receptor subtypes respectively). Furthermore, the time-dependent loss of (/sup 3/H)(-)QNB binding produced by 100 ..mu..M EEDQ was faster in homogenates of hippocampus than brainstem. Administration of EEDQ (20 mg/kg i.p.) irreversibly reduced the Bmax of (/sup 3/H)(-)QNB binding by 56% and 34% in hippocampus and brainstem respectively. Pirenzepine competition for the remaining (/sup 3/H)(-)QNB binding sites following in vitro and in vivo treatment with EEDQ revealedmore » a significant increase in the proportion of (/sup 3/H)(-)QNB binding sites having low affinity for pirenzepine (M/sub 2/ receptors), indicating that the high affinity pirenzepine binding sites (M/sub 1/ receptors) were selectively and irreversibly lost. Thus, EEDQ discriminates the same putative M/sub 1/ and M/sub 2/ muscarinic receptor subtypes that are discriminated by pirenzepine. The reduction of (/sup 3/H)(-)QNB binding could be prevented both in vitro and in vivo by atropine or scopolamine. These data may indicate differences in the accessibility of these putative receptor subtypes to EEDQ or, alternatively, differences in the availability of carboxyl groups able to interact with EEDQ at the ligand recognition site of M/sub 1/ and M/sub 2/ muscarinic receptors.« less

LACERTA I AND CASSIOPEIA III. TWO LUMINOUS AND DISTANT ANDROMEDA SATELLITE DWARF GALAXIES FOUND IN THE 3{pi} PAN-STARRS1 SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Nicolas F.; Laevens, Benjamin P. M.; Slater, Colin T.

We report the discovery of two new dwarf galaxies, Lacerta I/Andromeda XXXI (Lac I/And XXXI) and Cassiopeia III/Andromeda XXXII (Cas III/And XXXII), in stacked Pan-STARRS1 r{sub P1}- and i{sub P1}-band imaging data. Both are luminous systems (M{sub V} {approx} -12) located at projected distances of 20. Degree-Sign 3 and 10. Degree-Sign 5 from M31. Lac I and Cas III are likely satellites of the Andromeda galaxy with heliocentric distances of 756{sup +44}{sub -28} kpc and 772{sup +61}{sub -56} kpc, respectively, and corresponding M31-centric distances of 275 {+-} 7 kpc and 144{sup +6}{sub -4} kpc. The brightest of recent Local Groupmore » member discoveries, these two new dwarf galaxies owe their late discovery to their large sizes (r{sub h} = 4.2{sup +0.4}{sub -0.5} arcmin or 912{sup +124}{sub -93} pc for Lac I; r{sub h} = 6.5{sup +1.2}{sub -1.0} arcmin or 1456 {+-} 267 pc for Cas III) and consequently low surface brightness ({mu}{sub 0} {approx} 26.0 mag arcsec{sup -2}), as well as to the lack of a systematic survey of regions at large radii from M31, close to the Galactic plane. This latter limitation is now alleviated by the 3{pi} Pan-STARRS1 survey, which could lead to the discovery of other distant Andromeda satellite dwarf galaxies.« less

Full-dimensional quantum dynamics study of the H{sub 2} + C{sub 2}H → H + C{sub 2}H{sub 2} reaction on an ab initio potential energy surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Liuyang; University of Chinese Academy of Sciences, Beijing 100049; Shao, Kejie

2016-05-21

This work performs a time-dependent wavepacket study of the H{sub 2} + C{sub 2}H → H + C{sub 2}H{sub 2} reaction on a new ab initio potential energy surface (PES). The PES is constructed using neural network method based on 68 478 geometries with energies calculated at UCCSD(T)-F12a/aug-cc-pVTZ level and covers H{sub 2} + C{sub 2}H↔H + C{sub 2}H{sub 2}, H + C{sub 2}H{sub 2} → HCCH{sub 2}, and HCCH{sub 2} radial isomerization reaction regions. The reaction dynamics of H{sub 2} + C{sub 2}H → H + C{sub 2}H{sub 2} are investigated using full-dimensional quantum dynamics method. The initial-state selected reactionmore » probabilities are calculated for reactants in eight vibrational states. The calculated results showed that the H{sub 2} vibrational excitation predominantly enhances the reactivity while the excitation of bending mode of C{sub 2}H slightly inhibits the reaction. The excitations of two stretching modes of C{sub 2}H molecule have negligible effect on the reactivity. The integral cross section is calculated with J-shift approximation and the mode selectivity in this reaction is discussed. The rate constants over 200-2000 K are calculated and agree well with the experimental measured values.« less

Crystallization and X-ray data analysis of the 10 kDa C-terminal lid subdomain from Caenorhabditis elegans Hsp70

DOE Office of Scientific and Technical Information (OSTI.GOV)

Worrall, Liam; Walkinshaw, Malcolm D., E-mail: m.walkinshaw@ed.ac.uk

Crystals of the C-terminal 10 kDa lid subdomain from the C. elegans chaperone Hsp70 have been obtained that diffract X-rays to ∼3.5 Å and belong to space group I2{sub 1}2{sub 1}2{sub 1}. Analysis of X-ray data and initial heavy-atom phasing reveals 24 monomers in the asymmetric unit related by 432 non-crystallographic symmetry. Hsp70 is an important molecular chaperone involved in the regulation of protein folding. Crystals of the C-terminal 10 kDa helical lid domain (residues 542–640) from a Caenorhabditis elegans Hsp70 homologue have been produced that diffract X-rays to ∼3.4 Å. Crystals belong to space group I2{sub 1}2{sub 1}2{sub 1},more » with unit-cell parameters a = b = 197, c = 200 Å. The Matthews coefficient, self-rotation function and Patterson map indicate 24 monomers in the asymmetric unit, showing non-crystallographic 432 symmetry. Molecular-replacement studies using the corresponding domain from rat, the only eukaryotic homologue with a known structure, failed and a mercury derivative was obtained. Preliminary MAD phasing using SHELXD and SHARP for location and refinement of the heavy-atom substructure and SOLOMON for density modification produced interpretable maps with a clear protein–solvent boundary. Further density-modification, model-building and refinement are currently under way.« less

Synthesis, crystal structure, and ionic conductivity of a new layered metal phosphate, Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Sung-Chul; Kwak, Hyun-Jung; Yoo, Chung-Yul

2016-11-15

A new layered metal phosphate, Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3}, was synthesized in the form of either a single-crystal or polycrystalline powder using the molten hydroxide flux method or a solid-state reaction, respectively. Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3} crystallizes to the P2{sub 1}/n (Z=4) monoclinic space group with lattice parameters a≈4.95 Å, b≈22.06 Å, c≈8.63 Å, and β≈91.5°. The structure is composed of stacked [LiSrAl(PO{sub 4}){sub 2}] layers alternating regularly with [LiSrPO{sub 4}] layers. In the [LiSrAl(PO{sub 4}){sub 2}] sublattice, the AlO{sub 6} octahedra and PO{sub 4} tetrahedra are tilted cooperatively to form an anionic, corrugated, two-dimensional [Al(PO{sub 4}){sub 2}]{supmore » 3−} framework that can be regarded as a “distorted-glaserite” structure. The [LiSrPO{sub 4}] sublattice is that of a layered block containing a six-membered ring formed from alternating linkages of LiO{sub 4} and PO{sub 4} tetrahedra. The six-membered rings show a boat-type arrangement with the up(U) or down(D) pointing sequence, UUDUUD. The interspace between the two sublattices generates a two-dimensional pathway for Li{sup +} ion conduction. The impedance measurement indicated that Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3} had a moderate ion conductivity (σ≈1.30×10{sup −4} S cm{sup −1} at 667 K), with an activation energy E{sub a}≈1.02 eV. - Graphical abstract: Polyhedral view of Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3}. Li{sup +} ions are represented by green spheres, Sr atoms by white spheres, AlO{sub 6} groups by octahedra, and PO{sub 4} groups by tetrahedra. - Highlights: • New compound Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3} is reported. • The crystal structure is investigated by single-crystal XRD analysis. • The structure is formed by the alternate stacking of two different sublattices. • Correlation between the crystal structure and ionic conductivity is discussed.« less

Structural, microstructural and vibrational analyses of the monoclinic tungstate BiLuWO{sub 6}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ait Ahsaine, H.; Taoufyq, A.; Institut Matériaux Microélectronique et Nanosciences de Provence, IM2NP, UMR CNRS 7334, Université de Toulon, BP 20132, 83957 La Garde Cedex

2014-10-15

The bismuth lutetium tungstate phase BiLuWO{sub 6} has been prepared using a solid state route with stoichiometric mixtures of oxide precursors. The obtained polycrystalline phase has been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. In the first step, the crystal structure has been refined using Rietveld method: the crystal cell was resolved using monoclinic system (parameters a, b, c, β) with space group A2/m. SEM images showed the presence of large crystallites with a constant local nominal composition (BiLuW). TEM analyses showed that the actual local structure could be better representedmore » by a superlattice (a, 2b, c, β) associated with space groups P2 or P2/m. The Raman spectroscopy showed the presence of vibrational bands similar to those observed in the compounds BiREWO{sub 6} with RE=Y, Gd, Nd. However, these vibrational bands were characterized by large full width at half maximum, probably resulting from the long range Bi/Lu disorder and local WO{sub 6} octahedron distortions in the structure. - Graphical abstract: The average structure of BiLuWO{sub 6} determined from X-ray diffraction data can be represented by A2/m space group. Experimental Electron Diffraction patterns along the [0vw] zone axes of the monoclinic structure and associated simulated patterns show the existence of a monoclinic superstructure with space group P2 or P2/m. - Highlights: • A new monoclinic BiLuWO{sub 6} phase has been elaborated from solid-state reaction. • The space group of the monoclinic disordered average structure should be A2/m. • Transmission electron microscopy leads to a superlattice with P2/m space group. • Raman spectroscopy suggests existence of local disorder.« less

Classification of andisol soil on robusta coffee plantation in Silima Pungga - Pungga District

NASA Astrophysics Data System (ADS)

Marbun, P.; Nasution, Z.; Hanum, H.; Karim, A.

2018-02-01

The survey study aims to classify the Inceptisol soil on Robusta coffee plantation in Silima Pugga-Pungga District, from Order level to Sub Group level. The study was conducted on location of sample soil profiles which were determined based on Soil Map Unit (SMU) with the main Andisol Order, i.e. SMU 12, SMU 15 and SMU 17 of 18 existing SMU. The soil profiles were described to determine the morphological characteristics of the soil, while the physical and chemical properties were done by laboratory analysis. The soil samples were taken from each horizon in each profile and analyzed in the laboratory in the form of soil texture, bulk density, pH H2O, pH KCl, pH NaF, C-organic, exchangeable bases (Ca2+, Mg2+, K+, Na+), ZPC (zero point charge), base saturation, cation exchange capasity (CEC), P-retention, Al-Oxalate (Al-O) and Si-Oxalate (Si-O). The results showed that the classification of Andisol soil based on Soil Taxonomy only has one Sub Group namely Typic Hapludand. It is expected that the results of this study can provide information for more appropriate land management in order to increase the production of Robusta coffee plant in Silima Pungga-Pungga Sub district.

Effects of sulfur dioxide exposure on African-American and Caucasian asthmatics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heath, S.K.; Koenig, J.Q.; Morgan, M.S.

1994-07-01

There is concern that air pollution may be causing increases in asthma morbidity and mortality, especially among African-Americans. It is possible that there may be ethnic differences in susceptibility. To evaluate this speculation, a comparative pilot study of respiratory function in 10 African American and 12 Caucasian methacholine positive asthmatic males was conducted. Subjects were exposed to pure air or 1 ppm SO[sub 2] while breathing inside a polycarbonate head dome, for 10 min of rest and 10 min of exercise. Baseline and postexposure pulmonary function measurements were recorded, and nasal lavage fluid samples were collected and processed for epithelialmore » and white blood counts. Although significant increases were seen in total respiratory resistance following SO[sub 2] exposure in both groups (P = 0.04), no ethnic-based difference in response was seen. No significant differences were found in pulmonary or nasal measurements after exposure to SO[sub 2] between African-American and Caucasian subjects. No significant changes in epithelial or white blood cell count were found either when data were analyzed from the entire group or separately from the two subject groups. Even though there were no significant group changes, some individuals were particularly responsive to SO[sub 2]. Three Caucasian and 5 African-American subjects showed greater than 20% increases in respiratory resistance. 26 refs., 2 figs., 3 tabs.« less

Representations of S{sub {infinity}} admissible with respect to Young subgroups

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nessonov, Nikolai I

2012-03-31

Let N be the set of positive integers and S{sub {infinity}} the set of finite permutations of N. For a partition {Pi} of the set N into infinite parts A{sub 1},A{sub 2},... we denote by S{sub {Pi}} the subgroup of S{sub {infinity}} whose elements leave invariant each of the sets A{sub j}. We set S{sub {infinity}}{sup (N)}={l_brace}s element of S{sub {infinity}:} s(i)=i for any i=1,2,...,N{r_brace}. A factor representation T of the group S{sub {infinity}} is said to be {Pi}-admissible if for some N it contains a nontrivial identity subrepresentation of the subgroup S{sub {Pi}} intersection S{sub {infinity}}{sup (N)}. In themore » paper, we obtain a classification of the {Pi}-admissible factor representations of S{sub {infinity}}. Bibliography: 14 titles.« less

The effect of Bi composition on the properties of InP{sub 1−x}Bi{sub x} grown by liquid phase epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, T. D., E-mail: tddas@hotmail.com

InP{sub 1−x}Bi{sub x} epilayers (x ≥ 1.2%) on InP (001) are grown reproducibly by liquid phase epitaxy with conventional solution baking in a H{sub 2} environment. The Bi composition and surface morphology of the grown layers are studied by secondary ion mass spectroscopy and atomic force microscopy, respectively. High-resolution x-ray diffraction is used to characterize the lattice parameters and the crystalline quality of the layers. 10 K photoluminescence measurements indicate three clearly resolved peaks in undoped InP layers with band-to-band transition at 1.42 eV which is redshifted with Bi incorporation in the layer with a maximum band gap reduction of 50 meV/% Bi. The effectmore » is attributed to the interaction between the valence band edge and Bi-related defect states as is explained here by valence-band anticrossing model. Room temperature Hall measurements indicate that the mobility of the layer is not significantly affected for Bi concentration up to 1.2%.« less

Longitudinal comparison of outcomes after sub-Bowman keratomileusis and laser in situ keratomileusis: randomized, double-masked study.

PubMed

Wong, Rachel Chung Yin; Yu, Marco; Chan, Tommy C Y; Chong, Kelvin K L; Jhanji, Vishal

2015-05-01

To compare the outcomes of sub-Bowman keratomileusis (100-μm flap) and laser in situ keratomileusis (LASIK) (120-μm flap) using 150-kHz femtosecond laser. Randomized, double-masked, contralateral clinical trial. One hundred patients (200 eyes) with myopia or myopic astigmatism were included. Postoperative examinations were performed at week 1 and months 1, 3, 6, and 12. Main outcome measures included postoperative uncorrected (UCVA) and best-corrected distance visual acuity (BCVA); manifest refraction spherical equivalent; efficacy and safety indices; corneal thickness; and complications. The mean age of patients was 33.9 ± 7.9 years. Overall, the preoperative UCVA, BCVA, and manifest refraction spherical equivalent were 1.349 ± 0.332, -0.022 ± 0.033, and -5.81 ± 1.61 diopters, respectively. No significant difference was observed in preoperative (P ≥ .226) or intraoperative parameters (P ≥ .452) between both groups, except residual stromal thickness (P < .001). The UCVA, manifest refraction spherical equivalent, and central corneal thickness stabilized by 1 week, while the thinnest corneal thickness stabilized by 3 months postoperatively. There was no significant difference between both groups for any parameter during all follow-up visits (P ≥ .132) except the 3-month safety index, which was better in the sub-Bowman keratomileusis group (P = .007). Soft opaque bubble layer was noted intraoperatively in 12 cases (7, 100-μm group; 5, 120-μm group; P = .577). No postoperative complications were observed. Our study did not find any differences in the visual and refractive outcomes between femtosecond-assisted sub-Bowman keratomileusis and LASIK. Both surgeries resulted in quick visual recovery as early as 1 week postoperatively. Copyright © 2015 Elsevier Inc. All rights reserved.