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Sample records for 5posub 4sub 3f

  1. Solvothermal indium fluoride chemistry: Syntheses and crystal structures of K{sub 5}In{sub 3}F{sub 14}, beta-(NH{sub 4}){sub 3}InF{sub 6} and [NH{sub 4}]{sub 3}[C{sub 6}H{sub 21}N{sub 4}]{sub 2}[In{sub 4}F{sub 21}

    SciTech Connect

    Jayasundera, Anil C.A.; Goff, Richard J.; Li Yang; Finch, Adrian A.; Lightfoot, Philip

    2010-02-15

    The solvothermal syntheses and crystal structures of three indium fluorides are presented. K{sub 5}In{sub 3}F{sub 14} (1) and beta-(NH{sub 4}){sub 3}InF{sub 6} (2) are variants on known inorganic structure types chiolite and cryolite, respectively, with the latter exhibiting a complex and apparently novel structural distortion. [NH{sub 4}]{sub 3}[C{sub 6}H{sub 21}N{sub 4}]{sub 2}[In{sub 4}F{sub 21}] (3) represents a new hybrid composition displaying a unique trimeric metal fluoride building unit. - Graphical abstract: Solvothermal synthesis has been used to prepare three indium fluorides, including a novel hybrid material containing a unique [In{sub 3}F{sub 15}] trimer templated by tren.

  2. Crystal structure of Cs/sup +/((XeOF/sub 4/)/sub 3/F)/sup -/ and vibrational study of the /sup 18/O-enriched (XeOF/sub 5/)/sup -/ and ((XeOF/sub 4/)/sub 3/F)/sup -/ anions

    SciTech Connect

    Holloway, J.H.; Kaucic, V.; Martin-Rovet, D.; Russell, D.R.; Schrobilgen, G.J.; Selig, H.

    1985-02-27

    The cesium salts of the anions (XeOF/sub 5/)/sup -/ and ((XeOF/sub 4/)/sub 3/F)/sup -/ have been prepared and characterized. The Raman spectra of Xe/sup 16/OF/sub 5//sup -/ and Xe/sup 18/OF/sub 5//sup -/ are consistent with a stereochemically active lone pair in the xenon valence shell that results in a distorted octahedral arrangement of five fluorine and one oxygen around xenon to give C/sub s/ symmetry. The X-ray structure of Cs/sup +/((XeOF/sub 4/)/sub 3/F)/sup -/ has been obtained. Crystals are cubic, space group Pa3 with a = 13.993 (7) A and Z = 8. The structure was solved by means of Patterson and Fourier synthesis and refined by the least-squares method to R = 0.0969 and R/sub w/ = 0.0960 for 355 reflections. The anion possesses C/sub 3/ symmetry and consists of octahedra of O=XeF/sub 4/E (E = lone electron pair; mean XeF = 1.90 (3) A; Xe=O = 1.70 (5) A) linked through three fluorine bridges with the trigonally bonded fluorine positioned 0.49 A above the plane defined by the three xenon atoms. The Raman spectra of the /sup 16/O//sup 18/O isotopic isomers of (XeOF/sub 4/)/sub 3/F)/sup -/ and their associated coupling patterns have been interpreted on the basis of the X-ray structure. 33 references, 6 figures, 5 tables.

  3. Investigation of structural and luminescent properties of Ce{sup 3+}/Mn{sup 2+} ions-doped Ca{sub 5}(PO{sub 4}){sub 3}F

    SciTech Connect

    Zhang, Lei; Fu, Zuoling; Wu, Zhijian; Wang, Yuan; Fu, Xihong; Cui, Tian

    2014-08-15

    Graphical abstract: The structural and luminescent properties FAP: Ce{sup 3+} and FAP: Ce{sup 3+}, Mn{sup 2+} were investigated in detail by the spectral measurement and theoretical calculation. The emission of Ce{sup 3+} is fitted by two Gaussian functions dashed lines in wavenumber to further confirm the Ce{sup 3+} ion simultaneously occupy the 4f and 6h sites Ca{sub 5}(PO{sub 4})F host. - Highlights: • A simple hydrothermal method has been used to prepare Ca{sub 5}(PO{sub 4}){sub 3}F: Ce{sup 3+}, Mn{sup 2+} powders with structural and luminescent analysis. • The emission of Ce{sup 3+} is fitted by two Gaussian functions to confirm the Ce{sup 3+} ion simultaneously to occupy the 4f and 6h sites in Ca{sub 5}(PO{sub 4}){sub 3}F host. • Due to an efficient energy transfer, the existence of Ce{sup 3+} (sensitizer) can dramatically enhance the green emission of Mn{sup 2+} (activator) in co-doped samples. - Abstract: Ce{sup 3+}/Mn{sup 2+} ions-doped oxyapatite calcium fluorapatite [Ca{sub 5}(PO{sub 4}){sub 3}F, FAP] has been successfully synthesized by a facile one-step hydrothermal method. The luminescent properties of Ce{sup 3+}- and Ce{sup 3+}/Mn{sup 2+}- activated FAP phosphors were investigated using the photoluminescence (PL) and photoluminescence excitation (PLE) spectra. The emission of Ce{sup 3+} was fitted by two Gaussian functions with dashed lines in wavenumber to confirm the Ce{sup 3+} ion simultaneously to occupy the 4f and 6h sites in Ca{sub 5}(PO{sub 4}){sub 3}F host, which was consistent with the calculated results of crystal field based on chemical bond theory. In addition, the existence of Ce{sup 3+} (sensitizer) can dramatically enhance the green emission of Mn{sup 2+} (activator) in Ce{sup 3+}/Mn{sup 2+} ions co-doped samples due to an efficient energy transfer from Ce{sup 3+} to Mn{sup 2+}. All of these results could help us understand the site assignments and optical properties of the rare earth ions doped in hexagonal Ca{sub 5}(PO{sub 4

  4. Influence of 6s{sup 2} lone pair electrons of Bi{sup 3+} on its preferential site occupancy in fluorapatite, NaCa{sub 3}Bi(PO{sub 4}){sub 3}F – An insight from Eu{sup 3+} luminescent probe

    SciTech Connect

    Lakshminarasimhan, N. Varadaraju, U.V.

    2014-12-15

    Graphical abstract: Eu{sup 3+} structural probe – difference in Eu{sup 3+} PL emission in (a) NaCa{sub 3}Bi{sub 0.95}Eu{sub 0.05}(PO{sub 4}){sub 3}F and (b) NaCa{sub 3}La{sub 0.95}Eu{sub 0.05}(PO{sub 4}){sub 3}F suggests Bi{sup 3+} with preferential site occupancy at M(II) site directing Eu{sup 3+} to M(I) site. - Highlights: • Eu{sup 3+} luminescent probe used for establishing the role of 6s{sup 2} lone pair electrons of Bi{sup 3+} in fluorapatite. • Difference in Eu{sup 3+} PL emission spectral features in NaCa{sub 3}Bi{sub 0.95}Eu{sub 0.05}(PO{sub 4}){sub 3}F and NaCa{sub 3}La{sub 0.95}Eu{sub 0.05}(PO{sub 4}){sub 3}F. • Preferential site occupancy of Bi{sup 3+} in M(II) site directs Eu{sup 3+} to M(I) site in NaCa{sub 3}Bi{sub 0.95}Eu{sub 0.05}(PO{sub 4}){sub 3}F. - Abstract: Eu{sup 3+} luminescence was used as a structural probe in understanding the preferential site occupancy of lone pair cation, Bi{sup 3+}, in fluorapatite by comparing the photoluminescence (PL) emission spectral features with that of in analogous La{sup 3+} based fluorapatite. The fluorapatites, NaCa{sub 3}Bi{sub 0.95}Eu{sub 0.05}(PO{sub 4}){sub 3}F and NaCa{sub 3}La{sub 0.95}Eu{sub 0.05}(PO{sub 4}){sub 3}F, were synthesized by conventional high temperature solid state reaction method and characterized by powder X-ray diffraction (XRD) and FT-IR spectroscopy. The Eu{sup 3+} PL results revealed a difference in the emission spectral features in NaCa{sub 3}Bi{sub 0.95}Eu{sub 0.05}(PO{sub 4}){sub 3}F and NaCa{sub 3}La{sub 0.95}Eu{sub 0.05}(PO{sub 4}){sub 3}F. This difference in Eu{sup 3+} PL emission can be attributed to the difference in its site occupancy in the studied fluorapatites.

  5. Hydrothermal synthesis, crystal structure, and characterization of a new pseudo-two-dimensional uranyl oxyfluoride, [N(C{sub 2}H{sub 5}){sub 4}]{sub 2}[(UO{sub 2}){sub 4}(OH{sub 2}){sub 3}F{sub 10}

    SciTech Connect

    Ok, Kang Min; O'Hare, Dermot

    2007-02-15

    A new uranyl oxyfluoride, [N(C{sub 2}H{sub 5}){sub 4}]{sub 2}[(UO{sub 2}){sub 4}(OH{sub 2}){sub 3}F{sub 10}] has been synthesized by a hydrothermal reaction technique using (C{sub 2}H{sub 5}){sub 4}NBr, UO{sub 2}(OCOCH{sub 3}){sub 2}.2H{sub 2}O, and HF as reagents. The structure of [N(C{sub 2}H{sub 5}){sub 4}]{sub 2}[(UO{sub 2}){sub 4}(OH{sub 2}){sub 3}F{sub 10}] has been determined by a single-crystal X-ray diffraction technique. [N(C{sub 2}H{sub 5}){sub 4}]{sub 2}[(UO{sub 2}){sub 4}(OH{sub 2}){sub 3}F{sub 10}] crystallizes in the monoclinic space group P2{sub 1}/n (No. 14), with a=13.852(3)A, b=15.532(3)A, c=16.481(3)A, {beta}=98.88(3){sup o}, V=3503.4(12)A{sup 3}, and Z=4. [N(C{sub 2}H{sub 5}){sub 4}]{sub 2}[(UO{sub 2}){sub 4}(OH{sub 2}){sub 3}F{sub 10}] reveals a novel pseudo-two-dimensional crystal structure that is composed of UO{sub 2}F{sub 5}, UO{sub 3}F{sub 4}, and UO{sub 4}F{sub 3} pentagonal bipyramids. Each uranyl pentagonal bipyramid shares edges and corners through F atoms to form a six-membered ring. The rings are further interconnected to generate infinite strips running along the b-axis. [N(C{sub 2}H{sub 5}){sub 4}]{sub 2}[(UO{sub 2}){sub 4}(OH{sub 2}){sub 3}F{sub 10}] has been further characterized by elemental analysis, bond valence calculations, Infrared and Raman spectroscopy, and thermogravimetric analysis.

  6. 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

    SciTech Connect

    Lozinsek, Matic; Bunic, Tina; Goreshnik, Evgeny; Meden, Anton; Tramsek, Melita; Tavcar, Gasper; Zemva, Boris

    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. 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 (a

  7. Ca(5)Zr(3)F(22).

    PubMed

    Oudahmane, Abdelghani; El-Ghozzi, Malika; Avignant, Daniel

    2012-04-01

    Single crystals of Ca(5)Zr(3)F(22), penta-calcium trizirconium docosafluoride, were obtained unexpectedly by solid-state reaction between CaF(2) and ZrF(4) in the presence of AgF. The structure of the title compound is isotypic with that of Sr(5)Zr(3)F(22) and can be described as being composed of layers with composition [Zr(3)F(20)](8-) made up from two different [ZrF(8)](4-) square anti-prisms (one with site symmetry 2) by corner-sharing. The layers extending parallel to the (001) plane are further linked by Ca(2+) cations, forming a three-dimensional network. Amongst the four crystallographically different Ca(2+) ions, three are located on twofold rotation axes. The Ca(2+) ions exhibit coordination numbers ranging from 8 to 12, depending on the cut off, with very distorted fluorine environments. Two of the Ca(2+) ions occupy inter-stices between the layers whereas the other two are located in void spaces of the [Zr(3)F(20)](8-) layer and alternate with the two Zr atoms along [010]. The crystal under investigation was an inversion twin. PMID:22589749

  8. Thermodynamic Model for the Solubility of Ba(SeO4sub>, SO4sub>) Precipitates

    SciTech Connect

    Rai, D.; Felmy, Andrew R.; Moore, Dean A.; Kitamura, Akira; Yoshikawa, Hideki; Doi, Reisuke; Yoshida, Yasushi

    2014-08-15

    The solubility of Ba(SeO4sub>, SO4sub>) precipitates was determined as a function of the BaSeO4sub> mole fractions, ranging from 0.0015 to 0.3830, and time with an equilibration period extending to as long as 302 days. Equilibrium/steady state conditions in this system are reached in ≤ 65 days. Pitzer’s ion interaction model was used to calculate solid and aqueous phase activity coefficients. Thermodynamic analyses showed that the data do not satisfy Gibbs-Duhem equation, thereby demonstrating that a single-solid solution phase does not control both the selenate and sulfate concentrations. Our extensive data with log 10 [Ba] ranging from -3.6 to -5.9 mol kg-1, log 10 [SeO4sub>] rangingfrom-3.6 to -5.2 mol kg-1, and log 10 [SO4sub>] ranging from-4.0 to -5.3 mol kg-1 can be explained with the formation of an ideal BaSeO4sub> solid solution phase that controls the selenium concentrations and a slightly disordered/less-crystalline BaSO4sub>(s) (log 10Κ°sp = -9.5 instead of -10.05 for barite) that controls the sulfate concentrations. In these experiments the BaSO4sub> component of the solid solution phase never reaches thermodynamic equilibrium with the aqueous phase. Thermodynamic interpretations of the data show that both the ideal BaSeO4sub> solid solution phase and less-crystalline BaSO4sub> (s) phase are in equilibrium with each other in the entire range of BaSeO4sub> mole fractions investigated in this study.

  9. Near Infrared Luminescence Properties of Mn(5+): Ca5(PO4)3F

    NASA Technical Reports Server (NTRS)

    Davis, Valetta R.; Hoemmerich, Uwe; Loutts, George B.

    1997-01-01

    We report a spectroscopic investigation of Mn(5+) doped Ca5(PO4)(sub 3)F or FAP. Mn(5+) doped crystals have recently attracted world wide attention for potential solid-state laser applications. Following optical excitation of Mn: FAP with the 600 nm output of a Nd: YAG OPO laser system, we observed a strong near infrared luminescence centered at around 1150 nm. The room temperature luminescence decay time was measured to be approximately 635 microseconds. We attribute the infrared luminescence to the(1)E yields (3)A2 transition of tetrahedrally coordinated Mn5+ ions located in a strong crystal field environment. Absorption, luminescence and lifetime data of Mn: FAP will be presented and discussed.

  10. Solvate Structures and Computational/Spectroscopic Characterization of LiBF4sub> Electrolytes

    SciTech Connect

    Seo, D. M.; Boyle, Paul D.; Allen, Joshua L.; Han, Sang D.; Jonsson, Erlendur; Johansson, Patrik; Henderson, Wesley A.

    2014-07-21

    Crystal structures have been determined for both LiBF4sub> and HBF4sub> solvates—(acetonitrile)2:LiBF4sub>, (ethylene glycol diethyl ether)1:LiBF4sub>, (diethylene glycol diethyl ether)1:LiBF4sub>, (tetrahydrofuran)1:LiBF4, (methyl methoxyacetate)1:LiBF4sub>, (suc-cinonitrile)1:LiBF4sub>, (N,N,N',N",N"-pentamethyldiethylenetriamine)1:HBF4sub>, (N,N,N',N'-tetramethylethylenediamine)3/2:HBF4sub> and (phenanthroline)2:HBF4sub>. These, as well as other known LiBF4sub> solvate structures, have been characterized by Raman vibrational spectroscopy to unambiguously assign the anion Raman band positions to specific forms of BF4sub>-...Li+ cation coordination. In addition, complementary DFT calculations of BF4sub>-...Li+ cation complexes have provided additional insight into the challenges associated with accurately interpreting the anion interactions from experimental Raman spectra. This information provides a crucial tool for the characterization of the ionic association interactions within electrolytes.

  11. Temperature dependent luminescence characteristics of KBe2BO3F2 and RbBe2BO3F2

    NASA Astrophysics Data System (ADS)

    Martincik, J.; Babin, V.; Liu, L.; Wang, X.; Chen, C. T.; Beitlerova, A.; Mihokova, E.; Nikl, M.

    2015-04-01

    This paper reports on a study of the luminescence characteristics of KBe2BO3F2 (KBBF) and RbBe2BO3F2(RBBF) crystals in UV/visible spectral range. The KBBF crystals are very popular for their nonlinear optical properties, however they have a potential to be used as scintillators for neutron detection. To determine the effectiveness of KBBF scintillation we combine the results from measurements of optical absorption; radioluminescence; light yield; photoluminescence and decay kinetics in the temperature range 8-330 K. Temperature dependence of luminescence in KBBF crystals is discussed.

  12. Solution-processable glass LiI-Li4sub>SnS4sub> superionic conductors for all-solid-state Li-ion batteries

    SciTech Connect

    Kern Ho Park; Oh, Dae Yang; Choi, Young Eun; Nam, Young Jin; Han, Lili; Kim, Ju -Young; Xin, Huolin; Lin, Feng; Oh, Seung M.; Jung, Yoon Seok

    2015-12-22

    The new, highly conductive (4.1 × 10–4 S cm–1 at 30 °C), highly deformable, and dry-air-stable glass 0.4LiI-0.6Li4sub>SnS4sub> is prepared using a homogeneous methanol solution. Furthermore, the solution process enables the wetting of any exposed surface of the active materials with highly conductive solidified electrolytes (0.4LiI-0.6Li4sub>SnS4sub>), resulting in considerable improvements in electrochemical performances of these electrodes over conventional mixture electrodes.

  13. Near-infrared quantum-cutting luminescence and energy transfer properties of Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+},Ce{sup 3+} phosphors

    SciTech Connect

    Dong, S. L.; Lin, H. H. E-mail: qyzhang@scut.edu.cn; Yu, T.; Zhang, Q. Y. E-mail: qyzhang@scut.edu.cn

    2014-07-14

    The phosphors Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+} by co-doping Ce{sup 3+} have been synthesized by conventional high-temperature solid-state reaction method. Their spectroscopic properties in the UV-VIS-NIR range have been investigated. The first 5d crystal field level location and stokes shift have been determined from the UV excitation and emission spectra of Ca{sub 3}(PO{sub 4}){sub 2}:Ce{sup 3+}. The three-photon NIR quantum-cutting luminescence of Tm{sup 3+} assigned to the electronic transitions of {sup 1}G{sub 4}→{sup 3}H{sub 4}, {sup 3}H{sub 4}→{sup 3}F{sub 4} and {sup 3}F{sub 4}→{sup 3}H{sub 6} is observed, whether in Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+} or Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+},Ce{sup 3+}. The energy transfer from Ce{sup 3+} to Tm{sup 3+} takes place with energy-transfer efficiency up to 34.5% for the Ca{sub 3}(PO{sub 4}){sub 2}:Tm{sup 3+},Ce{sup 3+}. A cross relaxation scheme using the 5d states of Ce{sup 3+} and f-f transition of Tm{sup 3+} is proposed. The mechanism is revealed from energy level and decay measurements. The results show that the broadband absorption of Ce{sup 3+} sensitizer not only extends the spectrum conversion in UV region but also greatly enhances the photoluminescence intensities of the three-photon quantum cutting luminescence of Tm{sup 3+} doped Ca{sub 3}(PO{sub 4}){sub 2}.

  14. Partial discharges and breakdown in C3F8

    NASA Astrophysics Data System (ADS)

    Koch, M.; Franck, C. M.

    2014-10-01

    Traditional search processes of gases or gas mixtures for replacing SF6 involve time consuming measurements of partial discharges and breakdown behaviour for several voltage waveforms and different field configurations. Recently a model for prediction of this behaviour for SF6 was described in literature. The model only requires basic properties of the gas such as the critical field strength and the effective ionization coefficient, which can be obtained by swarm parameter measurements, and thermodynamic properties, which can be calculated. In this paper, we show for the well-known and electronegative gas octafluoropropane (C3F8) that it is possible to transfer the model developed for SF6 to this gas to describe the breakdown behaviour of C3F8. Thus the model can be beneficial in the screening process of new insulation gases.

  15. U(v) in metal uranates: A combined experimental and theoretical study of MgUO4sub>, CrUO4sub>, and FeUO4sub>

    SciTech Connect

    Guo, Xiaofeng; Tiferet, Eitan; Qi, Liang; Solomon, Jonathan M.; Lanzirotti, Antonio; Newville, Matthew; Engelhard, Mark H.; Kukkadapu, Ravi K.; Wu, Di; Ilton, Eugene S.; Asta, Mark; Sutton, Stephen R.; Xu, Hongwu; Navrotsky, Alexandra

    2016-01-01

    Although pentavalent uranium can exist in aqueous solution, its presence in the solid state is uncommon. Metal monouranates, MgUO4sub>, CrUO4sub> and FeUO4sub> were synthesized for detailed structural and energetic investigations. Structural characteristics of these uranates used powder X-ray diffraction, synchrotron X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, and 57Fe-Mossbauer spectroscopy. Enthalpies of formation were measured by high temperature oxide melt solution calorimetry. Density functional theory (DFT) calculations provided both structural and energetic information. The measured structural and thermodynamic properties show good consistency with those predicted from DFT. The presence of U5+ has been solidly confirmed in CrUO4sub> and FeUO4sub>, which are thermodynamically stable compounds, and the origin and stability of U5+ in the system was elaborated by DFT. Lastly, the structural and thermodynamic behaviour of U5+ elucidated in this work is relevant to fundamental actinide redox chemistry and to applications in the nuclear industry and radioactive waste disposal.

  16. ABET Criterion 3.f: how much curriculum content is enough?

    PubMed

    Barry, B E; Ohland, M W

    2012-06-01

    Even after multiple cycles of ABET accreditation, many engineering programs are unsure of how much curriculum content is needed to meet the requirements of ABET's Criterion 3.f (an understanding of professional and ethical responsibility). This study represents the first scholarly attempt to assess the impact of curriculum reform following the introduction of ABET Criterion 3.f. This study sought to determine how much professional and ethical responsibility curriculum content was used between 1995 and 2005, as well as how, when, why, and to what effect changes in the amount of content occurred. Subsequently, the study sought to evaluate if different amounts of curriculum content generated differing student outcomes. The amount of curriculum content used by each of the participating programs was identified during semi-structured interviews with program administrators and a review of ABET Self-Study documents. Quantitative methods were applied to determine if a relationship existed between the curriculum content and performance on a nationally administered, engineering-specific standardized examination. The findings indicate a statistical relationship, but a lack of structure between the amount of required content in the curriculum and performance on the examination. Additional findings were also generated regarding the way that programs interpret the Criterion 3.f feedback generated during accreditation visits. The primary impact of this study is that it dispels the myth that more courses or course time on professionalism and ethics will necessarily lead to positive engineering education outcomes. Much of the impetus to add more curriculum content results from a lack of conclusive feedback during ABET accreditation visits. PMID:21318324

  17. Investigation of dielectric properties of cold C3F8 mixtures and hot C3F8 gas as Substitutes for SF6

    NASA Astrophysics Data System (ADS)

    Wang, Xiaohua; Zhong, Linlin; Yan, Jing; Yang, Aijun; Han, Guohui; Han, Guiquan; Wu, Yi; Rong, Mingzhe

    2015-10-01

    In order to reduce the global warming potential resulting from SF6 widely used as an insulating and arc quenching medium, the substitutes need to be found. This paper focuses on different cold C3F8 mixtures (at room temperature) as an insulating gas and hot C3F8 gas (at temperatures of 300-3500 K) as an arc quenching medium, which seem to be a good replacement of SF6. Firstly, the dielectric properties, including the reduced ionization coefficient α / N, reduced electron attachment coefficient η / N and reduced critical electric field strength ( E / N)cr, of the cold C3F8-CF4, C3F8-CO2, C3F8-N2, C3F8-O2 and C3F8-Ar mixtures are calculated numerically using the two-term approximation of the Boltzmann equation. The dependence of such dielectric properties on the buffer gas proportion is investigated. Among the various C3F8 mixtures, the C3F8-N2 mixture has the lowest α / N and the C3F8-CF4 mixture has the largest η / N, and moreover, the C3F8-N2 mixture is the best insulator in terms of breakdown strength because it has the largest ( E / N)cr. Secondly, the ( E / N)cr of hot C3F8 at temperatures up to 3500 K and various pressures is determined and compared with that of hot SF6 gas. It is found that the hot C3F8 gas has much poorer dielectric performance than hot SF6 because the ( E / N)cr of C3F8 decreases significantly above room temperature.

  18. The novel phase transition of NaBi(WO{sub 4}){sub 2} under high pressure

    SciTech Connect

    Ma, Chunli; Cui, Hang; Li, Fangfei; Wang, Jingshu; Wu, Xiaoxin; Zhang, Jian; Zhou, Qiang; Liu, Jinghe; Cui, Qiliang

    2013-04-15

    The Raman and synchrotron angle-dispersive X-ray diffraction studies have been performed on NaBi(WO{sub 4}){sub 2} under high pressure up to 30.7 and 36.2 GPa, respectively, at room temperature. With pressure increases to ∼7.0 GPa, the structure of NaBi(WO{sub 4}){sub 2} begins to transform from tetragonal (I4{sub 1}/a) into monoclinic (P2/m), and the phase transition completes around 13 GPa. With pressure higher than 29.0 GPa, the NaBi(WO{sub 4}){sub 2} turns into amorphous state. The random arrangement of Na{sup +} and Bi{sup 3+} in short-range ordered scheelite NaBi(WO{sub 4}){sub 2} results in the tetragonal to monoclinic phase transition, which is different from that observed in AWO{sub 4} tungstates and AMoO{sub 4} molybdates (A=Ca, Sr, Ba, Pb, Eu, Cd). - Graphical abstract: The NaBi(WO{sub 4}){sub 2} transforms from tetragonal into monoclinic, which starts around 7 GPa and completes at about 13 GPa. With pressure higher than 29 GPa, the NaBi(WO{sub 4}){sub 2} turns into amorphous state. Highlights: ► Raman and X-ray diffraction studies performed on NaBi(WO{sub 4}){sub 2} up to 30.7 and 36.2 GPa, respectively. ► The tetragonal (I4{sub 1}/a) into monoclinic (P2/m) phase transition is determined. ► With pressure higher than 29 GPa, the NaBi(WO{sub 4}){sub 2} ultimately turns into amorphous state. ► The ambient pressure bulk modulus and volume of tetragonal and monoclinic phases are obtained.

  19. Spectral properties of Tm{sup 3+}:NaGd(MoO{sub 4}){sub 2} crystal

    SciTech Connect

    Wang Zujian; Li Xiuzhi; Wei Qian; Long Xifa

    2008-11-03

    The Tm{sup 3+}:NaGd(MoO{sub 4}){sub 2} crystal with dimensions of {phi} 15 x 38 mm{sup 2} was grown by Czochralski method. Polarized absorption and fluorescence spectra at room temperature were investigated. The absorption bands attributed to {sup 3}H{sub 6} {yields} {sup 3}H{sub 4} transition have large absorption cross-sections, which are 3.99 x 10{sup -20} and 2.36 x 10{sup -20} cm{sup 2} for {sigma}- and {pi}-polarization, respectively. The emission bands corresponding to the {sup 3}H{sub 4} {yields} {sup 3}H{sub 6} transition are strong and broad with emission cross-sections of 1.33 x 10{sup -20} and 1.20 x 10{sup -20} cm{sup 2} for {sigma}- and {pi}-polarization, respectively. The correlative full widths at half maximum are 35 nm for {sigma}-polarization and 36 nm for {pi}-polarization. The fluorescence lifetime for the {sup 3}H{sub 4} {yields} {sup 3}F{sub 4} transition is 146 {mu}s and the luminescent quantum efficiency is 76.8%.

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

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

  1. Aqueous Sulfate Separation by Sequestration of [(SO4sub>)2(H2O)4sub>]4sub> Clusters within Highly Insoluble Imine-Linked Bis-Guanidinium Crystals

    SciTech Connect

    Custelcean, Radu; Williams, Neil J.; Seipp, Charles A.; Ivanov, Aleksandr; Bryantsev, Vyacheslav

    2015-12-18

    Quantitative removal of sulfate from seawater was achieved by selective crystallization of the anion with a bis(guanidinium) ligand self-assembled in situ through imine condensation of simple components. The resulting crystalline salt has an exceptionally low aqueous solubility, on a par with BaSO4sub>. Single-crystal X-ray diffraction analysis revealed pairs of sulfate anions clustered together with four water molecules within the crystals.

  2. Native defects in Tl6SI4sub>: Density functional calculations

    SciTech Connect

    Shi, Hongliang; Du, Mao -Hua

    2015-05-05

    In this study, Tl6SI4sub> is a promising room-temperature semiconductor radiation detection material. Here, we report density functional calculations of native defects and dielectric properties of Tl6SI4sub>. Formation energies and defect levels of native point defects and defect complexes are calculated. Donor-acceptor defect complexes are shown to be abundant in Tl6SI4sub>. High resistivity can be obtained by Fermi level pinning by native donor and acceptor defects. Deep donors that are detrimental to electron transport are identified and methods to mitigate such problem are discussed. Furthermore, we show that mixed ionic-covalent character of Tl6SI4sub> gives rise to enhanced Born effective charges and large static dielectric constant, which provides effective screening of charged defects and impurities.

  3. Origin of modulated phases and magnetic hysteresis in TmB4sub>

    SciTech Connect

    Wierschem, Keola; Sunku, Sai Swaroop; Kong, Tai; Ito, Toshimitsu; Canfield, Paul C.; Panagopoulos, Christos; Sengupta, Pinaki

    2015-12-23

    In this study, we investigate the low-temperature magnetic phases in TmB4sub>, a metallic quantum magnet on the geometrically frustrated Shastry-Sutherland lattice, using coordinated experimental and theoretical studies. Our results provide an explanation for the appearance of the intriguing fractional plateau in TmB4sub> and accompanying magnetic hysteresis. Together with observation of the bump in the half plateau, our results support the picture that the magnetization plateau structure in TmB4sub> is strongly influenced by the zero-field modulated phases. We present a phenomenological model to explain the appearance of the modulated phases and a microscopic Hamiltonian that captures the complete magnetic behavior of TmB4sub>.

  4. Electroporation of DC-3F cells is a dual process.

    PubMed

    Wegner, Lars H; Frey, Wolfgang; Silve, Aude

    2015-04-01

    Treatment of biological material by pulsed electric fields is a versatile technique in biotechnology and biomedicine used, for example, in delivering DNA into cells (transfection), ablation of tumors, and food processing. Field exposure is associated with a membrane permeability increase usually ascribed to electroporation, i.e., formation of aqueous membrane pores. Knowledge of the underlying processes at the membrane level is predominantly built on theoretical considerations and molecular dynamics (MD) simulations. However, experimental data needed to monitor these processes with sufficient temporal resolution are scarce. The whole-cell patch-clamp technique was employed to investigate the effect of millisecond pulsed electric fields on DC-3F cells. Cellular membrane permeabilization was monitored by a conductance increase. For the first time, to our knowledge, it could be established experimentally that electroporation consists of two clearly separate processes: a rapid membrane poration (transient electroporation) that occurs while the membrane is depolarized or hyperpolarized to voltages beyond so-called threshold potentials (here, +201 mV and -231 mV, respectively) and is reversible within ∼100 ms after the pulse, and a long-term, or persistent, permeabilization covering the whole voltage range. The latter prevailed after the pulse for at least 40 min, the postpulse time span tested experimentally. With mildly depolarizing or hyperpolarizing pulses just above threshold potentials, the two processes could be separated, since persistent (but not transient) permeabilization required repetitive pulse exposure. Conductance increased stepwise and gradually with depolarizing and hyperpolarizing pulses, respectively. Persistent permeabilization could also be elicited by single depolarizing/hyperpolarizing pulses of very high field strength. Experimental measurements of propidium iodide uptake provided evidence of a real membrane phenomenon, rather than a mere

  5. Crystal Structure of Te 2O 3F 2

    NASA Astrophysics Data System (ADS)

    Ider, A.; Laval, J. P.; Frit, B.; Carré, J.; Bastide, J. P.

    1996-04-01

    Te2O3F2crystallizes with the triclinic symmetry (space groupP-1) and the unit cell parametersa= 515.3(1) pm,b= 625.7(1) pm,c= 688.8(1) pm, α = 98.71(1)°, β = 110.31(1)°, γ = 92.72(1)°,Z= 2. Its structure was solved and refined toRvaluesR1= 0.024 and wR2= 0.059 on the basis of 699 independent reflections recorded on a single crystal with an automatic four-circle diffractometer. The two Te atoms are, respectively, fourfold and fivefold coordinated and their lone pairEis stereochemically active. The bond valence calculation shows a perfect O/F order. The Te(1)O3FEand Te(2)O4FEpolyhedra form, by sharing O-O edges, bipolyhedral units with a very short Te-Te distance (319 pm). These units, by sharing corners, constitute independent sheets parallel tox0y. All the F atoms are nonbridging and orientated, together with the lone pairsE, toward the interlayer space. The structural relationships with the α-TeO2structure have been evidenced and analyzed.

  6. Role of Acentric Displacements on the Crystal Structure and Second-Harmonic Generating Properties of RbPbCO3F and CsPbCO3F

    PubMed Central

    2015-01-01

    Two lead fluorocarbonates, RbPbCO3F and CsPbCO3F, were synthesized and characterized. The materials were synthesized through solvothermal and conventional solid-state techniques. RbPbCO3F and CsPbCO3F were structurally characterized by single-crystal X-ray diffraction and exhibit three-dimensional (3D) crystal structures consisting of corner-shared PbO6F2 polyhedra. For RbPbCO3F, infrared and ultraviolet–visible spectroscopy and thermogravimetric and differential thermal analysis measurements were performed. RbPbCO3F is a new noncentrosymmetric material and crystallizes in the achiral and nonpolar space group P6̅m2 (crystal class 6̅m2). Powder second-harmonic generation (SHG) measurements on RbPbCO3F and CsPbCO3F using 1064 nm radiation revealed an SHG efficiency of approximately 250 and 300 × α-SiO2, respectively. Charge constants d33 of approximately 72 and 94 pm/V were obtained for RbPbCO3F and CsPbCO3F, respectively, through converse piezoelectric measurements. Electronic structure calculations indicate that the nonlinear optical response originates from the distorted PbO6F2 polyhedra, because of the even–odd parity mixing of the O 2p states with the nearly spherically symmetric 6s electrons of Pb2+. The degree of inversion symmetry breaking is quantified using a mode-polarization vector analysis and is correlated with cation size mismatch, from which it is possible to deduce the acentric properties of 3D alkali-metal fluorocarbonates. PMID:24867361

  7. Role of acentric displacements on the crystal structure and second-harmonic generating properties of RbPbCO3F and CsPbCO3F.

    PubMed

    Tran, T Thao; Halasyamani, P Shiv; Rondinelli, James M

    2014-06-16

    Two lead fluorocarbonates, RbPbCO3F and CsPbCO3F, were synthesized and characterized. The materials were synthesized through solvothermal and conventional solid-state techniques. RbPbCO3F and CsPbCO3F were structurally characterized by single-crystal X-ray diffraction and exhibit three-dimensional (3D) crystal structures consisting of corner-shared PbO6F2 polyhedra. For RbPbCO3F, infrared and ultraviolet-visible spectroscopy and thermogravimetric and differential thermal analysis measurements were performed. RbPbCO3F is a new noncentrosymmetric material and crystallizes in the achiral and nonpolar space group P6m2 (crystal class 6m2). Powder second-harmonic generation (SHG) measurements on RbPbCO3F and CsPbCO3F using 1064 nm radiation revealed an SHG efficiency of approximately 250 and 300 × α-SiO2, respectively. Charge constants d33 of approximately 72 and 94 pm/V were obtained for RbPbCO3F and CsPbCO3F, respectively, through converse piezoelectric measurements. Electronic structure calculations indicate that the nonlinear optical response originates from the distorted PbO6F2 polyhedra, because of the even-odd parity mixing of the O 2p states with the nearly spherically symmetric 6s electrons of Pb(2+). The degree of inversion symmetry breaking is quantified using a mode-polarization vector analysis and is correlated with cation size mismatch, from which it is possible to deduce the acentric properties of 3D alkali-metal fluorocarbonates. PMID:24867361

  8. The hydrogen permeability of Pd4sub>S

    SciTech Connect

    O’Brien, Casey P.; Gellman, Andrew J.; Morreale, Bryan D.; Miller, James B.

    2011-04-01

    Hydrogen permeates rapidly through pure Pd membranes, but H2S, a common minor component in hydrogencontaining streams, produces a Pd4sub>S film on the Pd surface that severely retards hydrogen permeation. Hydrogen still permeates through the bi-layered Pd4sub>S/Pd structure, indicating that the Pd4sub>S surface is active for H2 dissociation; the low hydrogen permeability of the Pd4sub>S film is responsible for the decreased rate of hydrogen transport. In this work, the hydrogen permeability of Pd4sub>S was determined experimentally in the 623-773 K temperature range. Bi-layered Pd4sub>S/Pd foils were produced by exposing pure Pd foils to H2S. H2 fluxes through the bi-layered Pd4sub>S/Pd foils were measured during exposure to both pure H2 and a 1000 ppm H2S in H2 gas mixture. Our results show that H2S slows hydrogen permeation through Pd mainly by producing a Pd4S film on the Pd surface that is roughly an order-of-magnitude less permeable to hydrogen (kPd4S = 10-7.5 exp(-0.22 eV/kBT)molH2/m/s/Pa-1/2) than pure Pd. The presence of H2S in the gas stream results in greater inhibition of hydrogen transport than can be explained by the very low permeability of Pd4sub>S. H2S may block H2 dissociation sites at the Pd4sub>S surface.

  9. Two-micron lasing in NaLa{sub 1/2}Gd{sub 1/2}(WO{sub 4}){sub 2} crystals doped with Tm{sup 3+} ions

    SciTech Connect

    Bolshchikov, F A; Ryabochkina, P A; Zharikov, Evgeny V; Lis, Denis A; Subbotin, Kirill A; Zakharov, N G; Antipov, Oleg L

    2010-02-28

    Lasing on the {sup 3}F{sub 4{yields}}{sup 3}H{sub 6} transition of Tm{sup 3+} ions in Tm{sup 3+}:NaLa{sub 1/2}Gd{sub 1/2}(WO{sub 4}){sub 2} crystals pumped by a diode laser is obtained for the first time. The {pi}- and {sigma}-polarised laser radiation at wavelengths of 1908 and 1918 nm was generated with a slope efficiency of 28% and 25%, respectively. (lasers)

  10. The role of carbonic anhydrase in C4sub> photosynthesis

    SciTech Connect

    Studer, Anthony

    2015-10-01

    Current pressures on the global food supply have accelerated the urgency for a second green revolution using novel and sustainable approaches to increase crop yield and efficiency. This proposal outlines experiments to address fundamental questions regarding the biology of C4sub> photosynthesis, the method of carbon fixation utilized by the most productive food, feed and bioenergy crops. Carbonic anhydrase (CA) has been implicated in multiple cellular functions including nitrogen metabolism, water use efficiency, and photosynthesis. CA catalyzes the first dedicated step in C4sub> photosynthesis, the hydration of CO2 into bicarbonate, and is potentially rate limiting in C4sub> grasses. Using insertional mutagenesis, we have generated CA mutants in maize, and propose the characterization of these mutants using phenotypic, physiological, and transcriptomic profiling to assay the plant’s response to altered CA activity. In addition, florescent protein tagging experiments will be employed to study the subcellular localization of CA paralogs, providing critical data for modeling carbon fixation in C4sub> plants. Finally, I propose parallel experiments in Setaria viridis to explore its relevance as model C4sub> grass. Using a multifaceted approach, this proposal addresses important questions in basic biology, as well as the need for translation research in response to looming global food challenges.

  11. Investigations On Stoichiometry And Melting Behavior Of NaY(WO{sub 4}){sub 2}

    SciTech Connect

    Salunke, R. G.; Gosavi, S. W.; Singh, S. G.; Singh, A. K.; Desai, D. G.; Chauhan, A. K.; Gadkari, S. C.

    2010-12-01

    Differential thermal analysis (DTA) and X-ray diffraction (XRD) studies were carried out to understand the melting behavior of the NaY(WO{sub 4}){sub 2}, an important functional material used for the laser production. It has been observed that the stoichiometric NaY(WO{sub 4}){sub 2} composition forms a solution with another phase of the Na{sub 2}WO{sub 4}-Y{sub 2}(WO{sub 4}){sub 3} pseudo-binary system. This is found to be detrimental for the growth of single crystals of the material. Therefore, molar fraction in the starting charge was suitably altered to successfully restrict the formation of the undesired phase in the melt. A composition is suggested for the favorable crystal growth of this material.

  12. Integrated Data Collection Analysis (IDCA) Program - KClO4sub>/Aluminum Mixture

    SciTech Connect

    Sandstrom, Mary M.; Brown, Geoffrey W.; Preston, Daniel N.; Pollard, Colin J.; Warner, Kirstin F.; Sorensen, Daniel N.; Remmers, Daniel L.; Whinnery, LeRoy L.; Shelley, Timothy J.; Reyes, Jose A.; Hsu, Peter C.; Reynolds, John G.

    2012-01-17

    The Integrated Data Collection Analysis (IDCA) program is conducting a Proficiency Test for Small-Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of a mixture of KClO4sub> and aluminum—KClO4sub>/Al mixture. This material was selected because of the challenge of performing SSST testing of a mixture of two solids. The mixture was found to be: 1) much less sensitive to impact than RDX, (LLNL being the exception) and PETN, 2) more sensitive to friction than RDX and PETN, and 3) extremely sensitive to spark. The thermal analysis showed little or no exothermic character. One prominent endothermic feature was observed in the temperature range studied and identified as a phase transition of KClO4sub>.

  13. Magnetic moment of the 4/sub 1//sup +/ state in /sup 20/Ne

    SciTech Connect

    Bright, T.; Ballon, D.; Saxena, R.J.; Niv, Y.; Benczer-Koller, a.N.

    1984-08-01

    The magnetic moment of the 4/sub 1//sup +/ state in /sup 20/Ne was measured by the transient field technique, and the transient field was calibrated in a simultaneous measurement on the 2/sub 1//sup +/ state. The resulting g(4/sub 1//sup +/) = 0.49 +- 0.34 is in agreement with the shell model description of /sup 20/Ne. The magnitude of the transient field measured in previous experiments on O, Ne, and Mg ions traversing iron foils was reexamined and appears to be in good agreement with the results of this experiment.

  14. Novel Solution Process for Fabricating Ultra-Thin-Film Absorber Layers in Fe2SiS4sub> and Fe2GeS4sub> Photovoltaics

    SciTech Connect

    Orefuwa, Samuel A.; Lai, Cheng-Yu; Dobson, Kevin D.; Ni, Chaoying; Radu, Daniela R.

    2014-05-12

    Fe2SiS4sub> and Fe2GeS4sub> crystalline materials posses direct bandgaps of ~1.55 and ~1.4 eV respectively and an absorption coefficient larger than 10^5 cm–1; their theoretical potential as solar photovoltaic absorbers has been demonstrated. However, no solar devices that employ either Fe2SiS4sub> or Fe2GeS4sub> have been reported to date. In the presented work, nanoprecursors to Fe2SiS4sub> and Fe2GeS4sub> have been fabricated and employed to build ultra-thin-film layers via spray coating and rod coating methods. Temperature-dependent X-Ray diffraction analyses of nanoprecursors coatings show an unprecedented low temperature for forming crystalline Fe2SiS4sub> and Fe2GeS4sub>. Fabricating of ultra-thin-film photovoltaic devices utilizing Fe2SiS4sub> and Fe2GeS4sub> as solar absorber material is presented.

  15. Negative thermal expansion in Th{sub 2}O(PO{sub 4}){sub 2}

    SciTech Connect

    Wallez, Gilles; Clavier, Nicolas; Dacheux, Nicolas

    2011-11-15

    Highlights: {yields} Dithorium oxide phosphate shows a continuous negative thermal expansion over a 600 {sup o}C range. {yields} Negative expansion arises from oxygen rocking and cations repulsions. {yields} Big and high-charge thorium IV appears ideal for generating negative expansion. -- Abstract: High temperature X ray diffraction performed on recently discovered orthorhombic Th{sub 2}O(PO{sub 4}){sub 2} shows a continuous linear thermal contraction (-1.6 x 10{sup -6} {sup o}C{sup -1}) in 20-600 {sup o}C range and a near-zero expansion at higher temperatures resulting from a dual structural deformation involving oxygen oscillations and inter-cations repulsions. Although similar mechanisms were observed in isotypic Zr{sub 2}O(PO{sub 4}){sub 2} (+1.5 x 10{sup -6} {sup o}C{sup -1}) and U{sub 2}O(PO{sub 4}){sub 2} (-1.4 x 10{sup -6} {sup o}C{sup -1}), those observed in Th{sub 2}O(PO{sub 4}){sub 2} are particularly intense because of the high ionic radius of tetravalent thorium.

  16. The superionic phase transitions in (NH{sub 4}){sub 3}H(SeO{sub 4}){sub 2} under hydrostatic pressure up to 400 MPa

    SciTech Connect

    Lindner, Ł.; Zdanowska-Frączek, M. Pawłowski, A.; Frączek, Z. J.

    2014-10-28

    The effect of hydrostatic pressure on proton conductivity of (NH{sub 4}){sub 3}H(SeO{sub 4}){sub 2} superionic crystal was studied in a wide temperature range and different isobaric conditions by means of impedance spectroscopy method. The measurements were performed along the trigonal c axis of the crystal, i.e., along the direction perpendicular to the plane in which, in the superionic phases, a dynamically disordered H-bond network is formed. The obtained pressure-temperature phase diagram is linear with increasing pressure. The triple point, which is the point of coexistence of the three phases: ferroelastic phase IV, ferroelastic phase III, and superionic phase II was found at p = 116.3 MPa and T = 287.3 K. High pressure leads to increase in the temperature range of stability of both superionic phases and to a drastic decrease in the temperature width of the ferroelastic phase III. With increasing pressure, the range of the superionic phase II expands at the expense of the range of the ferroelastic phase III, which is unstable and vanishes at the triple point.

  17. Structural Insights into HIV-1 Vif-APOBEC3F Interaction

    PubMed Central

    Nakashima, Masaaki; Ode, Hirotaka; Kawamura, Takashi; Kitamura, Shingo; Naganawa, Yuriko; Awazu, Hiroaki; Tsuzuki, Shinya; Matsuoka, Kazuhiro; Nemoto, Michiko; Hachiya, Atsuko; Sugiura, Wataru; Yokomaku, Yoshiyuki; Watanabe, Nobuhisa

    2015-01-01

    ABSTRACT The HIV-1 Vif protein inactivates the cellular antiviral cytidine deaminase APOBEC3F (A3F) in virus-infected cells by specifically targeting it for proteasomal degradation. Several studies identified Vif sequence motifs involved in A3F interaction, whereas a Vif-binding A3F interface was proposed based on our analysis of highly similar APOBEC3C (A3C). However, the structural mechanism of specific Vif-A3F recognition is still poorly understood. Here we report structural features of interaction interfaces for both HIV-1 Vif and A3F molecules. Alanine-scanning analysis of Vif revealed that six residues located within the conserved Vif F1-, F2-, and F3-box motifs are essential for both A3C and A3F degradation, and an additional four residues are uniquely required for A3F degradation. Modeling of the Vif structure on an HIV-1 Vif crystal structure revealed that three discontinuous flexible loops of Vif F1-, F2-, and F3-box motifs sterically cluster to form a flexible A3F interaction interface, which represents hydrophobic and positively charged surfaces. We found that the basic Vif interface patch (R17, E171, and R173) involved in the interactions with A3C and A3F differs. Furthermore, our crystal structure determination and extensive mutational analysis of the A3F C-terminal domain demonstrated that the A3F interface includes a unique acidic stretch (L291, A292, R293, and E324) crucial for Vif interaction, suggesting additional electrostatic complementarity to the Vif interface compared with the A3C interface. Taken together, these findings provide structural insights into the A3F-Vif interaction mechanism, which will provide an important basis for development of novel anti-HIV-1 drugs using cellular cytidine deaminases. IMPORTANCE HIV-1 Vif targets cellular antiviral APOBEC3F (A3F) enzyme for degradation. However, the details on the structural mechanism for specific A3F recognition remain unclear. This study reports structural features of interaction

  18. K2Pb3(CO3)3F2 and KCdCO3F: Novel Fluoride Carbonates with Layered and 3D Framework Structures.

    PubMed

    Lin, Yuan; Hu, Chun-Li; Mao, Jiang-Gao

    2015-11-01

    Two new mixed metal fluoride carbonates, KCdCO3F and K2Pb3(CO3)3F2, have been synthesized by solvothermal and solid-state techniques. KCdCO3F crystallizes in the acentric nonpolar space group P6̅m2, and its structure features a three-dimensional anionic framework in which the CdCO3 layers are further interconnected by bridging F(-) anions with the negative charge balanced by K(+) cations. K2Pb3(CO3)3F2 crystallizes in the centrosymmetric space group P63/mmc, and its structure exhibits a layered anionic skeleton featuring corner-shared PbO6F and PbO6F2 polyhedra. UV-vis diffuse reflectance spectroscopy studies show that the short-wavelength absorption edges of KCdCO3F and K2Pb3(CO3)3F2 are 227 and 287 nm, respectively. The second harmonic generation (SHG) measurement reveals that KCdCO3F is a phase-matchable material for generation of doubled-frequency light at both 532 and 266 nm, with a large SHG response of approximately 5.2 times that of KH2PO4 (KDP) at 532 nm and a moderate SHG response of approximately 0.75 times that of β-BaB2O4 (BBO) at 266 nm. Therefore, it is a promising UV material for fourth harmonic generation on a 1064 nm Q-switched Nd:YAG laser. PMID:26488674

  19. Role of APOBEC3F Gene Variation in HIV-1 Disease Progression and Pneumocystis Pneumonia

    PubMed Central

    An, Ping; Penugonda, Sudhir; Thorball, Christian W.; Bartha, Istvan; Goedert, James J.; Donfield, Sharyne; Buchbinder, Susan; Binns-Roemer, Elizabeth; Kirk, Gregory D.; Zhang, Wenyan; Fellay, Jacques; Yu, Xiao-Fang; Winkler, Cheryl A.

    2016-01-01

    Human APOBEC3 cytidine deaminases are intrinsic resistance factors to HIV-1. However, HIV-1 encodes a viral infectivity factor (Vif) that degrades APOBEC3 proteins. In vitro APOBEC3F (A3F) anti-HIV-1 activity is weaker than A3G but is partially resistant to Vif degradation unlike A3G. It is unknown whether A3F protein affects HIV-1 disease in vivo. To assess the effect of A3F gene on host susceptibility to HIV- acquisition and disease progression, we performed a genetic association study in six well-characterized HIV-1 natural cohorts. A common six-Single Nucleotide Polymorphism (SNP) haplotype of A3F tagged by a codon-changing variant (p. I231V, with allele (V) frequency of 48% in European Americans) was associated with significantly lower set-point viral load and slower rate of progression to AIDS (Relative Hazards (RH) = 0.71, 95% CI: 0.56, 0.91) and delayed development of pneumocystis pneumonia (PCP) (RH = 0.53, 95% CI: 0.37–0.76). A validation study in the International Collaboration for the Genomics of HIV (ICGH) showed a consistent association with lower set-point viral load. An in vitro assay revealed that the A3F I231V variant may influence Vif mediated A3F degradation. Our results provide genetic epidemiological evidence that A3F modulates HIV-1/AIDS disease progression. PMID:26942578

  20. Energy-transfer mechanisms in the CH3F-SF6 optically pumped laser

    NASA Technical Reports Server (NTRS)

    Lawandy, N. M.; Koepf, G. A.

    1980-01-01

    The power of an optically pumped CH3F laser operating on the 496-micron line has been doubled with the addition of SF6 without any corresponding increase in pump absorption. It is suggested that a near-resonant energy transfer between CH3F and SF6 followed by SF6 deactivation is the mechanism responsible for the enhancement.

  1. Role of APOBEC3F Gene Variation in HIV-1 Disease Progression and Pneumocystis Pneumonia.

    PubMed

    An, Ping; Penugonda, Sudhir; Thorball, Christian W; Bartha, Istvan; Goedert, James J; Donfield, Sharyne; Buchbinder, Susan; Binns-Roemer, Elizabeth; Kirk, Gregory D; Zhang, Wenyan; Fellay, Jacques; Yu, Xiao-Fang; Winkler, Cheryl A

    2016-03-01

    Human APOBEC3 cytidine deaminases are intrinsic resistance factors to HIV-1. However, HIV-1 encodes a viral infectivity factor (Vif) that degrades APOBEC3 proteins. In vitro APOBEC3F (A3F) anti-HIV-1 activity is weaker than A3G but is partially resistant to Vif degradation unlike A3G. It is unknown whether A3F protein affects HIV-1 disease in vivo. To assess the effect of A3F gene on host susceptibility to HIV- acquisition and disease progression, we performed a genetic association study in six well-characterized HIV-1 natural cohorts. A common six-Single Nucleotide Polymorphism (SNP) haplotype of A3F tagged by a codon-changing variant (p. I231V, with allele (V) frequency of 48% in European Americans) was associated with significantly lower set-point viral load and slower rate of progression to AIDS (Relative Hazards (RH) = 0.71, 95% CI: 0.56, 0.91) and delayed development of pneumocystis pneumonia (PCP) (RH = 0.53, 95% CI: 0.37-0.76). A validation study in the International Collaboration for the Genomics of HIV (ICGH) showed a consistent association with lower set-point viral load. An in vitro assay revealed that the A3F I231V variant may influence Vif mediated A3F degradation. Our results provide genetic epidemiological evidence that A3F modulates HIV-1/AIDS disease progression. PMID:26942578

  2. The crystal structure of Yb{sub 2}(SO{sub 4}){sub 3}.3H{sub 2}O and its decomposition product, {beta}-Yb{sub 2}(SO{sub 4}){sub 3}

    SciTech Connect

    Mills, Stuart J.; Petricek, Vaclav; Kampf, Anthony R.; Herbst-Imer, Regine; Raudsepp, Mati

    2011-09-15

    Yb{sub 2}(SO{sub 4}){sub 3}.3H{sub 2}O, synthesised by hydrothermal methods at 220(2) deg. C, has been investigated by single crystal X-ray diffraction. Yb{sub 2}(SO{sub 4}){sub 3}.3H{sub 2}O crystallises in space group Cmc2{sub 1} and is isostructural with Lu{sub 2}(SO{sub 4}){sub 3}.3H{sub 2}O. The crystal structure has been refined to R{sub 1}=0.0145 for 3412 reflections [F{sub o}>3{sigma}(F)], and 0.0150 for all 3472 reflections. The structure of Yb{sub 2}(SO{sub 4}){sub 3}.3H{sub 2}O is a complex framework of YbO{sub 6} octahedra, YbO{sub 8} and YbO{sub 5}(H{sub 2}O){sub 3} polyhedra and SO{sub 4} tetrahedra. Thermal data shows that Yb{sub 2}(SO{sub 4}){sub 3}.3H{sub 2}O decomposes between 120 and 190 deg. C to form {beta}-Yb{sub 2}(SO{sub 4}){sub 3}. The structure of a twinned crystal of {beta}-Yb{sub 2}(SO{sub 4}){sub 3} was solved and refined using an amplimode refinement in R3c with an R{sub 1}=0.0755 for 8944 reflections [F{sub o}>3{sigma}(F)], and 0.1483 for all 16,361 reflections. {beta}-Yb{sub 2}(SO{sub 4}){sub 3} has a unique structural topology based on a 3D network of pinwheels. - Graphical abstract: Octahedral-tetrahedral linkages found in Y{sub 2}(SO{sub 4}){sub 3} [and Er{sub 2}(SO{sub 4}){sub 3}] and ss-Yb{sub 2}(SO{sub 4}){sub 3}. Highlights: > The crystal structure and decomposition reactions of Yb{sub 2}(SO{sub 4}){sub 3}.3H{sub 2}O. > The crystal structure of a twinned crystal of {beta}-Yb{sub 2}(SO{sub 4}){sub 3}. > Comparison of the structures of {beta}-Yb{sub 2}(SO{sub 4}){sub 3} and Y{sub 2}(SO{sub 4}){sub 3}.

  3. Characterization of bubble core and cloudiness in Yb3+:Sr5(PO4)3F crystals using Micro-Raman spectroscopy

    SciTech Connect

    Cui, Y; Roy, U N; Bai, L; Burger, A; Qiu, S R; Schaffers, K

    2006-11-15

    Ytterbium doped strontium fluoroapatite Yb{sup 3+}:Sr{sub 5}(PO{sub 4}){sub 3}F (Yb: S-FAP) crystals have been used in High Average Power Laser systems as gain medium. Growth induced defects associated with the crystal often affect their performance. In order to improve the crystal quality and its optical applications, it is imperative to understand the nature of these defects. In this study, we utilize Micro-Raman spectroscopy to characterize two common growth-induced defects: bubble core and cloudiness. We find the bubble core consist of voids and microcrystals of Yb: S-FAP. These microcrystals have very different orientation from that of the pure crystal outside the bubble core. In contrast to a previous report, neither Sr{sub 3}(PO{sub 4}){sub 2} nor Yb{sub 2}O{sub 3} are observed in the bubble core regions. On the other hand, the cloudy regions are made up of the host materials blended with a structural deformation along with impurities which include CaCO{sub 3}, YbPO{sub 4}, SrHPO{sub 4} and Sr{sub 2}P{sub 2}O{sub 7}. The impurities are randomly distributed in the cloudy regions. This analysis is necessary for understanding and eliminating these growth defects in Yb:S-FAP crystals.

  4. Shape resonances in the photoionization of CF4sub>

    SciTech Connect

    Stephens, J. A.; Dill, Dan; Dehmer, Joseph L.

    1986-01-01

    Calculations of photoionization cross sections and photoelectron angular distributions have been performed for all occupied orbitals of CF4sub> using the multiple-scattering model. Results are compared with very recent experiments which employ synchrotron radiation to measure these quantities, namely the measurements of Truesdale e t a l. for the carbonK shell, and measurements of Carlson e t a l. and Novak e t a l. for the five outermost valence levels. The calculations predict intense shape resonances below 3 eV in continua of a1 and t2 final state symmetry. Qualitative agreement is attained on comparing much of the theory with experiment, notably the five outer valence levels, which serves to establish a one-electron picture of the photoionization dynamics of CF4sub>.

  5. Sub-nanosecond Yb:KLu(WO4sub>)2 microchip laser.

    PubMed

    Loiko, P; Serres, J M; Mateos, X; Yumashev, K; Yasukevich, A; Petrov, V; Griebner, U; Aguiló, M; Díaz, F

    2016-06-01

    A diode-pumped Yb:KLu(WO4sub>)2 microchip laser passively Q-switched by a Cr4+:YAG saturable absorber generated a maximum average output power of 590 mW at 1031 nm with a slope efficiency of 55%. The pulse characteristics were 690 ps/47.6 μJ at a pulse repetition frequency of 12.4 kHz. The output beam had an excellent circular profile with M2<1.05. Yb:KLu(WO4sub>)2 is very promising for ultrathin sub-ns microchip lasers. PMID:27244429

  6. Thermal decomposition behavior of the rare-earth ammonium sulfate R{sub 2}(SO{sub 4}){sub 3}.(NH{sub 4}){sub 2}SO{sub 4}

    SciTech Connect

    Nagai, Tsukasa; Tamura, Shinji; Imanaka, Nobuhito

    2010-07-15

    Rare-earth ammonium sulfate octahydrates of R{sub 2}(SO{sub 4}){sub 3}.(NH{sub 4}){sub 2}SO{sub 4}.8H{sub 2}O (R=Pr, Nd, Sm, and Eu) were synthesized by a wet process, and the stable temperature region for the anhydrous R{sub 2}(SO{sub 4}){sub 3}.(NH{sub 4}){sub 2}SO{sub 4} form was clarified by thermogravimetry/differential thermal analysis, infrared, Raman, and electrical conductivity measurements. Detailed characterization of these double salts demonstrated that the thermal stability of anhydrous R{sub 2}(SO{sub 4}){sub 3}.(NH{sub 4}){sub 2}SO{sub 4} is different between the Pr, Nd salts and the Sm, Eu salts, and the thermal decomposition behavior of these salts was quite different from the previous reports. - Graphical abstract: Stable temperature range of anhydrous rare-earth ammonium sulfate R{sub 2}(SO{sub 4}){sub 3}.(NH{sub 4}){sub 2}SO{sub 4} was clarified by thermogravimetry/differential thermal analysis, infrared, Raman, and electrical conductivity measurements. Since the previous reports were based only on thermal analysis, the present work has more accurately determined the exact thermal stability of rare-earth ammonium sulfate solids.

  7. Crystal Chemistry of Electrochemically and Chemically Lithiated Layered αI-LiVOPO4sub>

    SciTech Connect

    He, Guang; Bridges, Craig A.; Manthiram, Arumugam

    2015-09-14

    LiVOPO4sub> is an attractive cathode for lithium-ion batteries with a high operating voltage and the potential to achieve the reversible insertion of two lithium ions between VOPO4sub> and Li2VOPO4sub>. Among the three known forms of LiVOPO4sub> (α, β, and αI), the αI-LiVOPO4sub> has a layered structure that could promote better ionic mobility and reversibility than others. However, a comprehensive study of its lithiated product is not available as αI-LiVOPO4sub> is metastable and difficult to prepare by conventional approaches. We present here a facile synthesis of highly crystalline αI-LiVOPO4sub> and αI-LiVOPO4sub>/rGO nanocomposite by a microwave-assisted solvothermal method and its electrochemical/chemical lithiation. The LiVOPO4sub>/rGO cathodes exhibit a high reversible capacity of 225 mAh g–1, indicating the insertion of more than one lithium into VOPO4sub>. Both electrochemical and chemical lithiation imply a solid-solution reaction mechanism on inserting the second lithium into αI-LiVOPO4sub>, but a two-phase reaction feature could also occur under certain conditions such as insufficient time for equilibration of Li+ diffusion in the structure. The fully lithiated new αI-Li2VOPO4sub> phase was characterized by combined Rietveld refinement of neutron diffraction and X-ray diffraction data and by bond-valence sum maps. The results suggest that αI-Li2VOPO4sub> retains the tetragonal P4/nmm symmetry of the parent αI-LiVOPO4sub> structure, where the second lithium ions are located in the lithium layers rather than in the VOPO4sub> layers

  8. Semaphorin 3F and neuropilin-2 control the migration of human T-cell precursors.

    PubMed

    Mendes-da-Cruz, Daniella Arêas; Brignier, Anne Colette; Asnafi, Vahid; Baleydier, Frederic; Messias, Carolina Valença; Lepelletier, Yves; Bedjaoui, Nawel; Renand, Amedée; Smaniotto, Salete; Canioni, Danielle; Milpied, Pierre; Balabanian, Karl; Bousso, Philippe; Leprêtre, Stéphane; Bertrand, Yves; Dombret, Hervé; Ifrah, Norbert; Dardenne, Mireille; Macintyre, Elizabeth; Savino, Wilson; Hermine, Olivier

    2014-01-01

    Neuropilins and semaphorins are known as modulators of axon guidance, angiogenesis, and organogenesis in the developing nervous system, but have been recently evidenced as also playing a role in the immune system. Here we describe the expression and role of semaphorin 3F (SEMA3F) and its receptor neuropilin-2 (NRP2) in human T cell precursors. NRP2 and SEMA3F are expressed in the human thymus, in both lymphoid and non-lymphoid compartments. SEMA3F have a repulsive effect on thymocyte migration and inhibited CXCL12- and sphingosine-1-phosphate (S1P)-induced thymocyte migration by inhibiting cytoskeleton reorganization prior to stimuli. Moreover, NRP2 and SEMA3F are expressed in human T-cell acute lymphoblastic leukemia/lymphoma primary cells. In these tumor cells, SEMA3F also blocks their migration induced by CXCL12 and S1P. Our data show that SEMA3F and NRP2 are further regulators of human thymocyte migration in physiological and pathological conditions. PMID:25068647

  9. Collisional narrowing by polyatomic buffer gases in an optically pumped CH3F laser

    NASA Technical Reports Server (NTRS)

    Lawandy, N. M.; Koepf, G. A.

    1980-01-01

    The gain linewidth of an optically pumped CH3F molecular laser is observed with the addition of various polyatomic buffer gases. This is interpreted as collisional (Dicke) narrowing. The measurement is the first observation of collisional narrowing by polyatomic buffer gases. It is also the first observation of the effect in a laser oscillator. The effect was observed using a heterodyne mixing technique at the laser emission frequency of 604 GHz. Collision cross sections for SF6-CH3F and CS2-CH3F are obtained.

  10. Be2BO3F: A Phase of Beryllium Fluoride Borate Derived from KBe2BO3F2 with Short UV Absorption Edge.

    PubMed

    Guo, Shu; Liu, Lijuan; Xia, Mingjun; Kang, Lei; Huang, Qian; Li, Chao; Wang, Xiaoyang; Lin, Zheshuai; Chen, Chuangtian

    2016-07-01

    A phase of beryllium fluoride borate Be2BO3F (BBF) was successfully developed and grown by spontaneous nucleation from high temperature solution. The crystal belongs to the trigonal space group of R3̅c (No. 167), with lattice parameters a = 4.442(1) Å, c = 24.956(5) Å, and Z = 2. It is constructed by the infinite planar [Be2BO3F2]∞ layers, in which the planar triangle [BO3](3-) and the tetrahedral [BeO3F](5-) anionic groups are arranged in parallel via corner-sharing O atoms in each ab plane. BBF is an incongruent compound and decomposes at about 650 °C. The deep-ultraviolet (DUV) transmittance spectrum reveals that its UV cutoff wavelength is down to ∼150 nm. Theoretical calculations show that BBF has a large birefringence (Δn = 0.13 at 200 nm), which mainly originates from the infinite planar [Be2BO3F2]∞ layers. In conclusion, BBF may be served as a potential DUV birefringent material. PMID:27332696

  11. Shock wave study of the thermal dissociations of C3F6 and c-C3F6. I. dissociation of hexafluoropropene.

    PubMed

    Cobos, C J; Sölter, L; Tellbach, E; Troe, J

    2014-07-10

    The thermal dissociation of C3F6 was studied between 1330 and 2210 K in shock waves monitoring the UV absorption of CF2. CF2 yields of about 2.6 per parent C3F6 were obtained at reactant concentrations of 500-1000 ppm in the bath gas Ar. These yields dropped to about 1.8 when reactant concentrations were lowered to 60 ppm. The increase of the CF2 yield with increasing concentration was attributed to bimolecular reactions between primary and secondary dissociation products. Quantum-chemical and kinetic modeling calculations helped to estimate the contributions from the various primary dissociation steps. It was shown that the measurements correspond to unimolecular reactions in their falloff range. Falloff representations of the rate constants are given, leading to an overall high pressure rate constant k∞ = 2.0 × 10(17)(-104 kcal mol(-1)/RT) s(-1) and a relative rate of about 2/3:1/3 for the reactions C3F6 → CF3CF + CF2 versus C3F6 → C2F3 + CF3. PMID:24905383

  12. Generation and Standardized, Systemic Phenotypic Analysis of Pou3f3L423P Mutant Mice

    PubMed Central

    Kumar, Sudhir; Rathkolb, Birgit; Kemter, Elisabeth; Sabrautzki, Sibylle; Michel, Dian; Adler, Thure; Becker, Lore; Beckers, Johannes; Busch, Dirk H.; Garrett, Lillian; Hans, Wolfgang; Hölter, Sabine M.; Horsch, Marion; Klingenspor, Martin; Klopstock, Thomas; Rácz, Ildikó; Rozman, Jan; Vargas Panesso, Ingrid Liliana; Vernaleken, Alexandra; Zimmer, Andreas; Fuchs, Helmut; Gailus-Durner, Valérie; Hrabě de Angelis, Martin; Wolf, Eckhard; Aigner, Bernhard

    2016-01-01

    Increased levels of blood plasma urea were used as phenotypic parameter for establishing novel mouse models for kidney diseases on the genetic background of C3H inbred mice in the phenotype-driven Munich ENU mouse mutagenesis project. The phenotypically recessive mutant line HST011 was established and further analyzed. The causative mutation was detected in the POU domain, class 3 transcription factor 3 (Pou3f3) gene, which leads to the amino acid exchange Pou3f3L423P thereby affecting the conserved homeobox domain of the protein. Pou3f3 homozygous knockout mice are published and show perinatal death. Line Pou3f3L423P is a viable mouse model harboring a homozygous Pou3f3 mutation. Standardized, systemic phenotypic analysis of homozygous mutants was carried out in the German Mouse Clinic. Main phenotypic changes were low body weight and a state of low energy stores, kidney dysfunction and secondary effects thereof including low bone mineralization, multiple behavioral and neurological defects including locomotor, vestibular, auditory and nociceptive impairments, as well as multiple subtle changes in immunological parameters. Genome-wide transcriptome profiling analysis of kidney and brain of Pou3f3L423P homozygous mutants identified significantly regulated genes as compared to wild-type controls. PMID:27003440

  13. Integrated Data Collection Analysis (IDCA) Program - KClO4sub>/Carbon Mixture

    SciTech Connect

    Sandstrom, Mary M.; Brown, Geoffrey W.; Preston, Daniel N.; Pollard, Colin J.; Warner, Kirstin F.; Sorensen, Daniel N.; Remmers, Daniel L.; Shelley, Timothy J.; Reyes, Jose A.; Hsu, Peter C.; Reynolds, John G.

    2013-01-31

    The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of a mixture of KClO4sub> and activated carbon—KClO4sub>/C mixture. This material was selected because of the challenge of performing SSST testing of a mixture of two solids. The mixture was found to be insensitive to impact, friction, and thermal stimulus, and somewhat sensitive to spark discharge. This effort, funded by the Department of Homeland Security (DHS), ultimately will put the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study has the potential to suggest new guidelines and methods and possibly establish the SSST testing accuracies needed to develop safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. The results are compared among the laboratories and then compared to historical data from various sources. The testing performers involved for the KClO4sub>/carbon mixture are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Indian Head Division, Naval Surface Warfare Center, (NSWC IHD), and Air Force Research Laboratory (AFRL/RXQL). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to understand how to compare results when these testing variables cannot be made consistent.

  14. Discovery of a metastable Al20Sm4sub> phase

    SciTech Connect

    Ye, Z.; Zhang, F.; Sun, Y.; Mendelev, M. I.; Ott, R. T.; Park, E.; Besser, M. F.; Kramer, M. J.; Ding, Z.; Wang, C. -Z.; Ho, K. -M.

    2015-03-09

    In this study, we present an efficient genetic algorithm, integrated with experimental diffraction data, to solve a nanoscale metastable Al20Sm4sub> phase that evolves during crystallization of an amorphous magnetron sputtered Al90Sm10 alloy. The excellent match between calculated and experimental X-ray diffraction patterns confirms an accurate description of this metastable phase. Molecular dynamic simulations of crystal growth from the liquid phase predict the formation of disordered defects in the devitrified crystal.

  15. SU(4){sub L}xU(1){sub X} models with little Higgs mechanism

    SciTech Connect

    Nam, Soo-hyeon; Lee, Kang Young; Keum, Yong-Yeon

    2010-11-15

    We study the aspects of the fermion and gauge boson sectors in SU(4){sub L}xU(1){sub X} models with a little Higgs mechanism. We introduce a new setup of fermions, which ensures the cancellation of gauge anomaly and the cancellation of one-loop quadratic divergence to the Higgs mass for all fermion multiplets and gauge bosons. We explicitly present the interactions between the standard model fermions and the heavy gauge bosons to discuss the phenomenological implications of extra Z{sup '} and Z{sup ''} gauge bosons based on recent experimental data.

  16. Integrated Data Collection Analysis (IDCA) program--KClO4sub>/Dodecane Mixture

    SciTech Connect

    Sandstrom, Mary M.; Brown, Geoffrey W.; Preston, Daniel N.; Pollard, Colin J.; Warner, Kirstin F.; Sorensen, Daniel N.; Remmers, Daniel L.; Shelley, Timothy J.; Reyes, Jose A.; Hsu, Peter C.; Reynolds, John G.

    2012-05-11

    The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of a mixture of KClO4sub> and dodecane—KClO4sub>/dodecane mixture. This material was selected because of the challenge of performing SSST testing of a mixture of solid and liquid materials. The mixture was found to: 1) be less sensitive to impact than RDX, and PETN, 2) less sensitive to friction than RDX and PETN, and 3) less sensitive to spark than RDX and PETN. The thermal analysis showed little or no exothermic features suggesting that the dodecane volatilized at low temperatures. A prominent endothermic feature was observed and assigned to a phase transition of KClO4sub>. This effort, funded by the Department of Homeland Security (DHS), ultimately will put the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study has the potential to suggest new guidelines and methods and possibly establish the SSST testing accuracies needed to develop safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. The results are compared among the laboratories and then compared to historical data from various sources. The testing performers involved for the KClO4sub>/dodecane mixture are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Indian Head Division, Naval Surface Warfare Center, (NSWC IHD), and Air Force Research Laboratory (AFRL/RXQL). These tests are conducted as a proficiency study in order to establish some

  17. Neutrino masses in SU(4){sub L}⊗U(1){sub X} gauge models

    SciTech Connect

    Palcu, Adrian

    2013-11-13

    Neutrino masses are obtained within SU(4){sub L}⊗U(1){sub X} electroweak gauge models with spontaneous symmetry breaking by simply exploiting the tree level realization of certain dimension-five effective operators. The scalar sector needs not to be enlarged, since these operators are constructed as direct products among scalar multiplets already existing in the model. There is a unique generic matrix for Yukawa couplings in the neutrino sector, while the charged leptons are already in their diagonal basis. The experimentally observed phenomenology in the neutrino sector is obtained as a natural consequence of this particular approach.

  18. Synthesis and crystal structure of two synthetic oxofluoride framework compounds--Co2TeO3F2 and Co2SeO3F2.

    PubMed

    Hu, Shichao; Johnsson, Mats

    2012-11-01

    Two new isostructural Co(2+) containing tellurium and selenium oxofluoride compounds Co(2)TeO(3)F(2) and Co(2)SeO(3)F(2) are synthesized and their structures determined by single crystal X-ray diffraction. They crystallize in the orthorhombic space group Pnma with the unit cell parameters a = 7.3810(5) Å, b = 10.1936(7) Å, c = 5.3013(3) Å and a = 7.2655(8) Å, b = 10.0013(13) Å, c = 5.3564(6) Å, respectively. The Co(II) ion has octahedral coordination [CoO(3)F(3)] and builds up a 3D framework by corner- and edge sharing. The Se(IV) and the Te(IV) ions have the coordinations [SeO(3)E] and [TeO(3)E] respectively where E is the lone-pair electrons. The Se(IV) and Te(IV) ions are isolated from each other and bond only to the [CoO(3)F(3)] polyhedra. The electronegative element fluorine takes the role of a network builder like oxygen and helps to form the 3D framework structure. This is a difference compared to many oxohalide compounds containing Cl and Br where the halide ions are terminating ions preventing a 3D network from being formed. Long range antiferromagnetic interactions dominate at temperatures < 20 K. The magnetic susceptibility follows the Curie-Weiss law above 25 K with the Curie constant C = 5.62 emu K mol(-1), the Weiss temperature θ = -56 K and the effective magnetic moment μ(eff) = 4.74 μ(B) per cobalt atom. PMID:22968840

  19. A dispersive treatment of Kl4sub> decays

    SciTech Connect

    Colangelo, Gilberto; Passemar, Emilie; Stoffer, Peter

    2015-04-28

    Kl4sub> decays offer several reasons of interest: they allow an accurate measurement of ππ-scattering lengths; they provide the best source for the determination of some low-energy constants of xPT; one form factor is directly related to the chiral anomaly, which can be measured here. We present a dispersive treatment of Kl4sub> decays that provides a resummation of ππ- and Kπ-rescattering effects. In addition, the free parameters of the dispersion relation are fitted to the data of the high-statistics experiments E865 and NA48/2. The matching toxPT at NLO and NNLO enables us to determine the LECs Lr1, Lr2 and Lr3. With recently published data from NA48/2, the LEC Lr9 can be determined as well. In contrast to a pure chiral treatment, the dispersion relation describes the observed curvature of one of the form factors, which we understand as a rescattering effect beyond NNLO.

  20. Neural Cell Adhesion Molecule NrCAM Regulates Semaphorin 3F-Induced Dendritic Spine Remodeling

    PubMed Central

    Demyanenko, Galina P.; Mohan, Vishwa; Zhang, Xuying; Brennaman, Leann H.; Dharbal, Katherine E.S.; Tran, Tracy S.; Manis, Paul B.

    2014-01-01

    Neuron-glial related cell adhesion molecule (NrCAM) is a regulator of axon growth and repellent guidance, and has been implicated in autism spectrum disorders. Here a novel postsynaptic role for NrCAM in Semaphorin3F (Sema3F)-induced dendritic spine remodeling was identified in pyramidal neurons of the primary visual cortex (V1). NrCAM localized to dendritic spines of star pyramidal cells in postnatal V1, where it was coexpressed with Sema3F. NrCAM deletion in mice resulted in elevated spine densities on apical dendrites of star pyramidal cells at both postnatal and adult stages, and electron microscopy revealed increased numbers of asymmetric synapses in layer 4 of V1. Whole-cell recordings in cortical slices from NrCAM-null mice revealed increased frequency of mEPSCs in star pyramidal neurons. Recombinant Sema3F-Fc protein induced spine retraction on apical dendrites of wild-type, but not NrCAM-null cortical neurons in culture, while re-expression of NrCAM rescued the spine retraction response. NrCAM formed a complex in brain with Sema3F receptor subunits Neuropilin-2 (Npn-2) and PlexinA3 (PlexA3) through an Npn-2-binding sequence (TARNER) in the extracellular Ig1 domain. A trans heterozygous genetic interaction test demonstrated that Sema3F and NrCAM pathways interacted in vivo to regulate spine density in star pyramidal neurons. These findings reveal NrCAM as a novel postnatal regulator of dendritic spine density in cortical pyramidal neurons, and an integral component of the Sema3F receptor complex. The results implicate NrCAM as a contributor to excitatory/inhibitory balance in neocortical circuits. PMID:25143608

  1. 29 CFR 780.158 - Examples of other practices within section 3(f) if requirements are met.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Examples of other practices within section 3(f) if requirements are met. 780.158 Section 780.158 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR... within Section 3(f) § 780.158 Examples of other practices within section 3(f) if requirements are met....

  2. 29 CFR 780.158 - Examples of other practices within section 3(f) if requirements are met.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Examples of other practices within section 3(f) if requirements are met. 780.158 Section 780.158 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR... within Section 3(f) § 780.158 Examples of other practices within section 3(f) if requirements are met....

  3. 29 CFR 780.158 - Examples of other practices within section 3(f) if requirements are met.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Examples of other practices within section 3(f) if requirements are met. 780.158 Section 780.158 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR... within Section 3(f) § 780.158 Examples of other practices within section 3(f) if requirements are met....

  4. 29 CFR 780.158 - Examples of other practices within section 3(f) if requirements are met.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Examples of other practices within section 3(f) if requirements are met. 780.158 Section 780.158 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR... within Section 3(f) § 780.158 Examples of other practices within section 3(f) if requirements are met....

  5. 29 CFR 780.158 - Examples of other practices within section 3(f) if requirements are met.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Examples of other practices within section 3(f) if requirements are met. 780.158 Section 780.158 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR... within Section 3(f) § 780.158 Examples of other practices within section 3(f) if requirements are met....

  6. Synthesis, structure, and optical properties of CsU{sub 2}(PO{sub 4}){sub 3}

    SciTech Connect

    Oh, George N.; Ringe, Emilie; Van Duyne, Richard P.; Ibers, James A.

    2012-01-15

    CsU{sub 2}(PO{sub 4}){sub 3} was synthesized in highest yield by the reaction in a fused-silica tube of U, P, and Se in a CsCl flux at 1273 K. It crystallizes with four formula units in space group P2{sub 1}/n of the monoclinic system in a new structure type. The structure of CsU{sub 2}(PO{sub 4}){sub 3} is composed of U and Cs atoms coordinated by PO{sub 4}{sup 3-} units in distorted octahedral arrangements. Each U atom corner shares with six PO{sub 4}{sup 3-} units. Each Cs atom face shares with one, edge shares with two, and corner shares with three PO{sub 4}{sup 3-} units. The structure shares some features with the sodium zirconium phosphate structure type. X-ray powder diffraction results demonstrate that the present CsU{sub 2}(PO{sub 4}){sub 3} compound crystallizes in a structure different from the previously reported {beta} Prime - and {gamma}-CsU{sub 2}(PO{sub 4}){sub 3} compounds. CsU{sub 2}(PO{sub 4}){sub 3} is highly pleochroic, as demonstrated by single-crystal optical absorption measurements. - Graphical abstract: Stacking of the layers in CsU{sub 2}(PO{sub 4}){sub 3}, viewed along [100]. Highlights: Black-Right-Pointing-Pointer Compound CsU{sub 2}(PO{sub 4}){sub 3} crystallizes in a new structure type. Black-Right-Pointing-Pointer Structure shares some features with the sodium zirconium phosphate structure type. Black-Right-Pointing-Pointer CsU{sub 2}(PO{sub 4}){sub 3} is highly pleochroic, as demonstrated by single-crystal optical absorption measurements.

  7. Magnetic properties of the superconducting polymers (SN)/sub x/ and (SNBr/sub 0. 4/)/sub x/

    SciTech Connect

    Dee, R.H.; Carolan, J.F.; Turrell, B.G.; Greene, R.L.

    1980-07-01

    The magnetizations of the superconducting sulfur nitrogen polymer (SN)/sub x/ and its brominated modification, (SNBr/sub 0.4/)/sub x/, have been studied as a function of magnetic field and temperature. There is anisotropy in the magnetization observed in both materials. However, (SNBr/sub 0.4/)/sub x/ behaves more like a bulk superconductor than (SN)/sub x/ does, indicating stronger interfiber coupling in the former.

  8. Heat capacity and neutron diffraction studies on the frustrated magnetic Co{sub 2}(OH)(PO{sub 4}){sub 1-x}(AsO{sub 4}){sub x} [0{<=}x{<=}1] solid solution

    SciTech Connect

    Pedro, I. de; Rojo, J.M.; Rodriguez Fernandez, J.; Sanchez Marcos, J.; Fernandez-Diaz, M.T.; Rojo, T.

    2012-04-15

    The Co{sub 2}(OH)(PO{sub 4}){sub 1-x}(AsO{sub 4}){sub x} [0{<=}x{<=}1] solid solution exhibits a complex magnetic behaviour due to the bond-frustration in its magnetic structure. Heat capacity measurements of the (x=0.1-0.5) phases show a three-dimensional magnetic ordering ({lambda} anomaly) that shifts to lower temperatures and becomes broader as the AsO{sub 4}{sup 3-} content increases. For x=0.75, no significant feature was observed whereas for higher arsenate ion content, x=0.9 and 1, a small maximum was detected. The magnetic structures of solid solution are consistent with the existence of predominant antiferromagnetic superexchange interactions through the |OH| and |XO{sub 4}| (X=P and As) groups between the Co{sup +2} ions. The substitution of PO{sub 4}{sup 3-} by AsO{sub 4}{sup 3-} anions by more than 90% substantially modifies the magnetic exchange pathways in the solid solution, leading to an incommensurate antiferromagnetic structure in Co{sub 2}(OH)(PO{sub 4}){sub 1-x}(AsO{sub 4}){sub x} [x=0.9 and 1] phases. - Graphical abstract: Magnetic structures of Co{sub 2}(OH)(PO{sub 4}){sub 1-x}(AsO{sub 4}){sub x} [0{<=}x{<=}1]. The ordering of the magnetic moments of Co{sup 2+} is in c direction for the two crystallographic positions (dimers and chains) in all compounds. The unit cell is surrounded by a red line. Highlights: Black-Right-Pointing-Pointer Synthesis of a new adamite-type compounds, Co{sub 2}(OH)(PO{sub 4}){sub 1-x}(AsO{sub 4}){sub x} (0.1, 0.25, 0.5, 0.75, 0.9) phases. Black-Right-Pointing-Pointer Co{sub 2}(OH)(PO{sub 4}){sub 1-x}(AsO{sub 4}){sub x} (0-1) solid solution; magnetic frustrated system. Black-Right-Pointing-Pointer High resolution neutron powder diffraction to determine the crystal structures. Black-Right-Pointing-Pointer Incommensurate magnetic structures at low temperature. Black-Right-Pointing-Pointer Magnetostructural correlations in cobalt-based Co{sub 2}(OH)XO{sub 4} (X=P and As) insulation compounds.

  9. Pressure-induced phase transitions in multiferroic RbFe(MoO{sub 4}){sub 2}-Raman scattering study

    SciTech Connect

    Maczka, M.; Ptak, M.; Luz-Lima, C.; Freire, P.T.C.; Paraguassu, W.; Guerini, S.; Hanuza, J.

    2011-10-15

    High pressure Raman scattering experiments were performed on RbFe(MoO{sub 4}){sub 2}. These experiments revealed that two phase transitions take place in RbFe(MoO{sub 4}){sub 2} at very low pressures, i.e. between ambient pressure and 0.2 GPa and between 0.4 and 0.7 GPa. Raman results showed that at the first phase transition the room temperature P3-bar m1 phase transforms into the P3-bar phase, which is also observed at ambient pressure below 190 K. The second pressure-induced phase transition occurs into a low symmetry phase of unknown symmetry. The performed lattice dynamics calculations for the P3-bar m1 phase and ab initio calculation of the structural changes under hydrostatic pressure helped us to get better insights into the mechanism of the observed phase transitions. - Graphical abstract: Raman spectra of RbFe(MoO{sub 4}){sub 2} crystal in the high wavenumber region recorded at different pressures during compression experiment. Highlights: > RbFe(MoO{sub 4}){sub 2} exhibits two pressure-induced phase transitions below 0.7 GPa. > First phase transition is from the P3-bar m1 into P3-bar structure. > Phase transitions in RbFe(MoO{sub 4}){sub 2} are similar as in KFe(MoO{sub 4}){sub 2}. > Transitions' pressures are much lower for the rubidium compound.

  10. Plexin A3 is involved in semaphorin 3F-mediated oligodendrocyte precursor cell migration.

    PubMed

    Xiang, Xin; Zhang, Xuan; Huang, Qi-Lin

    2012-11-21

    Class 3 semaphorins are expressed in the neurodevelopmental or damage repair phase of the central nervous system (CNS). They play an important role in guiding axon growth and directing cell migration, including the migration of oligodendrocyte precursor cells (OPCs). As co-receptors for semaphorin 3F(sema3F), the expression and role of neuropilin-2 (NRP2) and plexin A3 in OPC migration are unclear. Using RT-PCR, Western blot analysis, and immunofluorescence, we demonstrated that primary OPCs and immature oligodendrocytes from neonatal rats express NRP2 and plexin A3. After transfection with NRP2 siRNA and plexin A3 siRNA, the number of migrating OPCs attracted to sema3F remarkably decreased. These results suggest that plexin A3 is expressed in OPCs and immature oligodendrocytes and is involved in OPC migration. PMID:23063687

  11. Time-resolved luminescence spectroscopy of structurally disordered K3WO3F3 crystals

    NASA Astrophysics Data System (ADS)

    Omelkov, S. I.; Spassky, D. A.; Pustovarov, V. A.; Kozlov, A. V.; Isaenko, L. I.

    2016-08-01

    Three emission centers of exciton-like origin, with distinct relaxation time, emission and excitation spectra were revealed in K3WO3F3 and described taking into account its structural disordering. Low-temperature monoclinic phase of K3WO3F3 features few anion sites with mixed oxygen/fluorine occupancy per [WO3F3] octahedron. Therefore, different kinds of distorted octahedra form, providing different luminescence centers. The time-resolved luminescence spectroscopy technique was applied to distinguish these centers. The simultaneous thermal quenching of them above ∼200 K was qualitatively explained involving dynamic structural disorder of the compound. The energy transfer mechanism between centers was found and tentatively described by the diffusion of excitons. Apart from intrinsic luminescence, the PL of defect-related centers was discovered and the role of shallow charge carrier traps in the low-temperature persistent luminescence was revealed.

  12. Second harmonic generation of diamond-blade diced KTiOPO4sub> ridge waveguides.

    PubMed

    Chen, Chen; Rüter, Christian E; Volk, Martin F; Chen, Cheng; Shang, Zhen; Lu, Qingming; Akhmadaliev, Shavkat; Zhou, Shengqiang; Chen, Feng; Kip, Detlef

    2016-07-25

    We report on the fabrication of ridge waveguides in KTiOPO4sub> nonlinear optical crystals through carbon ion irradiation followed by precise diamond blade dicing. The diced side-walls have low roughness, which allows for low propagation loss of ~1dB/cm in fabricated of ridges. The waveguide property investigation has been performed at 1064 nm as well as 532 nm, showing good guidance at both TE and TM polarizations. Based on type II phase matching configuration, efficient second harmonic generation of green light at room temperature has been realized. High conversion efficiencies of ~1.12%W-1 and ~12.4% have been obtained for frequency doubling under the pump of continuous-wave (CW) and pulsed fundamental waves at 1064 nm, respectively. PMID:27464095

  13. Preparation and crystal structure of Na sub 3 SbO(PO sub 4 ) sub 2

    SciTech Connect

    Guyomard, D.; Pagnoux, C.; Verbaere, A.; Piffard, Y. ); Zah Letho, J.J. )

    1991-02-01

    The single phase compound Na{sub 3}SbO(PO{sub 4}){sub 2} was prepared by a solid state reaction. It crystallizes in the orthorhombic system, space group P2{sub 1}2{sub 1}2{sub 1} with a = 6.964(1) {angstrom}, b = 9.284(2) {angstrom}, c = 12.425(2) {angstrom}, Z = 4. The structure was determined from 968 reflections collected on a Nonius CAD4 automatic diffractometer with MoK{alpha} radiation. The final R index and weighted R{sub w} index are 0.031 and 0.039, respectively. The structure is built up from strings of corner-sharing SbO{sub 6} octahedra to which phosphate groups are linked by two of their vertices. These chains, running parallel to the a-axis, are separated from each other by sodium atoms.

  14. Anomalous magnetic structure and spin dynamics in magnetoelectric LiFePO4sub>

    SciTech Connect

    Toft-Petersen, Rasmus; Reehuis, Manfred; Jensen, Thomas B. S.; Andersen, Niels H.; Li, Jiying; Le, Manh Duc; Laver, Mark; Niedermayer, Christof; Klemke, Bastian; Lefmann, Kim; Vaknin, David

    2015-07-06

    We report significant details of the magnetic structure and spin dynamics of LiFePO4sub> obtained by single-crystal neutron scattering. Our results confirm a previously reported collinear rotation of the spins away from the principal b axis, and they determine that the rotation is toward the a axis. In addition, we find a significant spin-canting component along c. Furthermore, the possible causes of these components are discussed, and their significance for the magnetoelectric effect is analyzed. Inelastic neutron scattering along the three principal directions reveals a highly anisotropic hard plane consistent with earlier susceptibility measurements. While using a spin Hamiltonian, we show that the spin dimensionality is intermediate between XY- and Ising-like, with an easy b axis and a hard c axis. As a result, it is shown that both next-nearest neighbor exchange couplings in the bc plane are in competition with the strongest nearest neighbor coupling.

  15. Predicted energies and structures of {beta}-Ca{sub 3}(PO{sub 4}){sub 2}

    SciTech Connect

    Jay, E.E.; Michie, E.M.; Parfitt, D.; Rushton, M.J.D.; Fong, S.K.; Mallinson, P.M.; Metcalfe, B.L.; Grimes, R.W.

    2010-10-15

    One of the 6a cation sites of the {beta}-Ca{sub 3}(PO{sub 4}){sub 2} structure has previously been described as half occupied. Here, classical static lattice techniques are used to model the different configurations that the Ca ions can exhibit over these Ca(4) 6a sites. All possible configurations in the single primitive unit cell and a hexagonal supercell 3{sub h}x1x1 have been generated, along with configurationally averaged structures, that exhibit the experimentally reported R 3c symmetry. The lowest energy configuration of the primitive cell exhibits R 3 symmetry. Conversely, the lowest energy configurations derived from the hexagonal supercell, which are considerably more stable, exhibit P 3{sub 1} and P 3{sub 2} symmetries, which are isomorphic supergroups of R 3c. The implication of these simulations are discussed in terms of refined structural models of the material. - Graphical Abstract: One of the 6a cation sites of the {beta}-Ca{sub 3}(PO{sub 4}){sub 2} structure has previously been described as half occupied. Here, classical static lattice techniques are used to model the different configurations that the Ca ions can exhibit over these Ca(4) 6a sites. All possible configurations in the single primitive unit cell and a hexagonal supercell (3{sub h}x1x1) have been generated, along with configurationally averaged structures, that exhibits experimentally reported R 3c symmetry. The lowest energy configuration of the primitive cell exhibits R 3 symmetry. Conversely, the lowest energy configurations derived from the hexagonal supercell cell, which are considerably more stable, exhibit P 3{sub 1} and P 3{sub 2} symmetries, which are isomorphic supergroups of R 3c. The implication of these simulations are discussed in terms of refined structural models of the material.

  16. Census of Population and Housing, 1980: Summary Tape File 3F. Technical Documentation.

    ERIC Educational Resources Information Center

    Bureau of the Census (DOC), Washington, DC. Data User Services Div.

    This report provides technical documentation associated with a 1980 Census of Population and Housing Summary Tape File (STF) 3F--which contains responses to the extended questionnaire summarized in STF 3, aggregated by school district. The file contains sample data inflated to represent the total population, 100% counts, and unweighted sample…

  17. 1.92 Angstrom Zinc-Free APOBEC3F Catalytic Domain Crystal Structure.

    PubMed

    Shaban, Nadine M; Shi, Ke; Li, Ming; Aihara, Hideki; Harris, Reuben S

    2016-06-01

    The APOBEC3 family of DNA cytosine deaminases is capable of restricting the replication of HIV-1 and other pathogens. Here, we report a 1.92 Å resolution crystal structure of the Vif-binding and catalytic domain of APOBEC3F (A3F). This structure is distinct from the previously published APOBEC and phylogenetically related deaminase structures, as it is the first without zinc in the active site. We determined an additional structure containing zinc in the same crystal form that allows direct comparison with the zinc-free structure. In the absence of zinc, the conserved active site residues that normally participate in zinc coordination show unique conformations, including a 90 degree rotation of His249 and disulfide bond formation between Cys280 and Cys283. We found that zinc coordination is influenced by pH, and treating the protein at low pH in crystallization buffer is sufficient to remove zinc. Zinc coordination and catalytic activity are reconstituted with the addition of zinc only in a reduced environment likely due to the two active site cysteines readily forming a disulfide bond when not coordinating zinc. We show that the enzyme is active in the presence of zinc and cobalt but not with other divalent metals. These results unexpectedly demonstrate that zinc is not required for the structural integrity of A3F and suggest that metal coordination may be a strategy for regulating the activity of A3F and related deaminases. PMID:27139641

  18. IN VITRO PERCUTANEOUS APPROACH OF SODIUM ARSENATE IN B6C3F1 MICE

    EPA Science Inventory

    Percutaneous absorption of sodium [73As] arsenate in female B6C3F1 mice was investigated in this study from various exposure conditions, including solid compound, aqueous solution (100 and 250 ul) and soil (= 23 mg/cm2). In vitro diffusion experiments were conducted for 24 hr usi...

  19. 48 CFR 47.305-3 - F.o.b. origin solicitations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false F.o.b. origin... CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47.305-3 F.o.b. origin solicitations. When preparing f.o.b. origin solicitations, the contracting officer shall refer to 47.303, where...

  20. 48 CFR 47.303-3 - F.o.b. origin, freight allowed.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Administration prescribes commercial zones at Subpart B of 49 CFR part 372); and (2) An allowance for freight... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false F.o.b. origin, freight... CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47.303-3 F.o.b. origin,...

  1. 48 CFR 47.305-3 - F.o.b. origin solicitations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... result in f.o.b. origin contracts shall also contain requirements, information, provisions, and clauses... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false F.o.b. origin... CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47.305-3 F.o.b. origin...

  2. 48 CFR 47.303-3 - F.o.b. origin, freight allowed.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Administration prescribes commercial zones at Subpart B of 49 CFR part 372); and (2) An allowance for freight... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false F.o.b. origin, freight... CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47.303-3 F.o.b. origin,...

  3. 48 CFR 47.303-3 - F.o.b. origin, freight allowed.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Administration prescribes commercial zones at Subpart B of 49 CFR part 372); and (2) An allowance for freight... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false F.o.b. origin, freight... CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47.303-3 F.o.b. origin,...

  4. 48 CFR 47.305-3 - F.o.b. origin solicitations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false F.o.b. origin... CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47.305-3 F.o.b. origin solicitations. When preparing f.o.b. origin solicitations, the contracting officer shall refer to 47.303, where...

  5. 48 CFR 47.305-3 - F.o.b. origin solicitations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false F.o.b. origin... CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47.305-3 F.o.b. origin solicitations. When preparing f.o.b. origin solicitations, the contracting officer shall refer to 47.303, where...

  6. 48 CFR 47.305-3 - F.o.b. origin solicitations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false F.o.b. origin... CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47.305-3 F.o.b. origin solicitations. When preparing f.o.b. origin solicitations, the contracting officer shall refer to 47.303, where...

  7. 48 CFR 47.303-3 - F.o.b. origin, freight allowed.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Administration prescribes commercial zones at Subpart B of 49 CFR part 372); and (2) An allowance for freight... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false F.o.b. origin, freight... CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47.303-3 F.o.b. origin,...

  8. Shock wave study of the thermal dissociations of C3F6 and c-C3F6. II. dissociation of hexafluorocyclopropane and dimerization of CF2.

    PubMed

    Cobos, C J; Sölter, L; Tellbach, E; Troe, J

    2014-07-10

    The thermal dissociation of c-C3F6 has been studied in shock waves over the range 620-1030 K monitoring the UV absorption of CF2. The reaction was studied close to its high-pressure limit, but some high-temperature falloff was accounted for. Quantum-chemical and kinetic modeling rationalized the experimental data. The reaction is suggested to involve the 1,3 biradical CF2CF2CF2 intermediate. CF2 formed by the dissociation of c-C3F6 dimerizes to C2F4. The measured rate of this reaction is also found to correspond to the falloff range. Rate constants for 2CF2 → C2F4 as a function of temperature and bath gas concentration [Ar] are given and shown to be consistent with literature values for the high-pressure rate constants from experiments at lower temperatures and dissociation rate constants obtained in the falloff range at higher temperatures. The onset of falloff at intermediate temperatures is analyzed. PMID:24905207

  9. Luminescence properties of phosphate phosphor Ba{sub 3}Y(PO{sub 4}){sub 3}:Sm{sup 3+}

    SciTech Connect

    Yang, Fu; Liu, Yufeng; Tian, Xiaodong; Dong, Guoyi; Yu, Quanmao

    2015-05-15

    A series of reddish orange-emitting phosphate phosphors Ba{sub 3}Y{sub 1−x}(PO{sub 4}){sub 3}:xSm{sup 3+}(0.01≤x≤0.20) were synthesized by solid-state reaction. X-ray diffraction and photoluminescence spectra were utilized to characterize the structure and luminescence properties of as-synthesized phosphors. The optimized phosphors Ba{sub 3}Y{sub 0.95}(PO{sub 4}){sub 3}:0.05Sm{sup 3+} present several excitation bands from 300 to 500 nm, and exhibit intense reddish orange-emitting properties. The energy transfer type between Sm{sup 3+} ions was confirmed as d–d interaction by using Van Uitert model. The chromatic properties of the typical sample Ba{sub 3}Y(PO{sub 4}){sub 3}:0.05Sm{sup 3+} phosphor have been found to have chromaticity coordinates of (0.583, 0.405), which are located in reddish orange region under the excitation of 401 nm. These results indicated that Ba{sub 3}Y(PO{sub 4}){sub 3}:Sm{sup 3+} phosphors have potential applications in the field of lighting and display due to their effective excitation in the near-ultraviolet range. - Graphical abstract: The color coordinates for 5 mol% Sm{sup 3+} doped Ba{sub 3}Y(PO{sub 4}){sub 3} phosphor were calculated to be (0.583, 0.405), which are located in reddish orange region under the excitation of 401 nm. The peaks of Ba{sub 3}Y{sub 0.95}(PO{sub 4}){sub 3}:0.05Sm{sup 3+} phosphor with the highest emission intensity at 600 nm are broader than those of Y{sub 2}O{sub 3}:Eu{sup 3+} and Y{sub 2}O{sub 2}S:Eu{sup 3+} phosphors. All these characteristics suggest that Ba{sub 3}Y(PO{sub 4}){sub 3}:Sm{sup 3+} phosphors are suitable for near-UV (370–410 nm) excitation and can be applicable to near UV-based WLEDs. ▪ - Highlights: • Different concentration Sm{sup 3+}-doped Ba{sub 3}Y(PO{sub 4}){sub 3} phosphors were fabricated by solid state method. • The optimized phosphors present the several excitation bands from 300 to 500 nm. • The Ba{sub 3}Y(PO{sub 4}){sub 3}:Sm{sup 3+} shows bright reddish orange

  10. New insight in the structure-luminescence relationships of Ca{sub 9}Eu(PO{sub 4}){sub 7}

    SciTech Connect

    Benhamou, Rajia Ait; Bessiere, Aurelie; Wallez, Gilles; Viana, Bruno; Elaatmani, Mohamed; Daoud, Mohamed; Zegzouti, Abdelwahed

    2009-08-15

    The double phosphate Ca{sub 9}Eu(PO{sub 4}){sub 7}, obtained by solid state reaction, was found to be isotypic with Ca{sub 3}(PO{sub 4}){sub 2}, with space group R3c and unit cell parameters a=10.4546(1) A, c=37.4050(3) A, V=3540.67(9) A{sup 3}, Z=6. The structure parameters refined using the Rietveld method showed that europium shares positions M1, M2 and M3 with calcium, contradicting previously published Moessbauer results. Low temperature luminescence under selective excitation of Eu{sup 3+} in Ca{sub 9}Y{sub 1-x}Eu{sub x}(PO{sub 4}){sub 7} and in Ca{sub 9}Eu(PO{sub 4}){sub 7} samples was studied, confirming the Eu{sup 3+} distribution into these sites. At 10 K, {sup 5}D{sub 0}->{sup 7}F{sub 0} emission lines of Eu{sup 3+} were observed at 578.5, 579.5, 580.1 nm for the M3, M1 and M2 sites, respectively. High temperature X-ray powder diffraction evidenced a second-order phase transition around 573 deg. C. - Graphical Abstract: Emission spectra of Ca{sub 9}Eu(PO{sub 4}){sub 7} recorded at 10 K evidencing the three different sites for Eu{sup 3+} dopant cation.

  11. Insights into the structure of mixed CO2/CH4sub> in gas hydrates

    SciTech Connect

    Everett, S. Michelle; Rawn, Claudia J.; Chakoumakos, Bryan C.; Keffer, David J.; Huq, Ashfia; Phelps, Tommy J.

    2015-05-12

    The exchange of carbon dioxide for methane in natural gas hydrates is an attractive approach to harvesting CH4sub> for energy production while simultaneously sequestering CO2. In addition to the energy and environmental implications, the solid solution of clathrate hydrate (CH4sub>)1-x(CO2)x·5.75H2O provides a model system to study how the distinct bonding and shapes of CH4sub> and CO2 influence the structure and properties of the compound. In this paper, high-resolution neutron diffraction was used to examine mixed CO2/CH4sub> gas hydrates. CO2-rich hydrates had smaller lattice parameters, which were attributed to the higher affinity of the CO2 molecule interacting with H2O molecules that form the surrounding cages, and resulted in a reduction in the unit-cell volume. Experimental nuclear scattering densities illustrate how the cage occupants and energy landscape change with composition. Finally, these results provide important insights on the impact and mechanisms for the structure of mixed CH4sub>/CO2 gas hydrate.

  12. Mechanisms for pressure-induced crystal-crystal transition, amorphization, and devitrification of Snl4sub>

    SciTech Connect

    Liu, Hanyu; Tse, John S.; Hu, Michael Y.; Bi, Wenli; Zhao, Jiyong; Alp, E. Ercan; Pasternak, Moshe; Taylor, R. Dean; Lashley, Jason C.

    2015-10-27

    The pressure-induced amorphization and subsequent recrystallization of SnI4sub> have been investigated using first principles molecular dynamics calculations together with high-pressure 119Sn nuclear resonant inelastic x-ray scattering measurements. Above ~8 GPa, we observe a transformation from an ambient crystalline phase to an intermediate crystal structure and a subsequent recrystallization into a cubic phase at ~64 GPa. The crystalline-to-amorphous transition was identified on the basis of elastic compatibility criteria. The measured tin vibrational density of states shows large amplitude librations of SnI4sub> under ambient conditions. Although high pressure structures of SnI4sub> were thought to be determined by random packing of equal-sized spheres, we detected electron charge transfer in each phase. As a result, this charge transfer results in a crystal structure packing determined by larger than expected iodine atoms. (C) 2015 AIP Publishing LLC.

  13. Crystal structure of the high-temperature modification of ytterbium perrhenate Yb(ReO{sub 4}){sub 3}

    SciTech Connect

    Khrustalev, V.N.; Varfolomeev, M.B.; Shamrai, N.B.; Struchkov, Yu.T.; Pisarevskii, A.P. |

    1993-11-01

    Yb(ReO{sub 4}){sub 3} obtained by the slow crystallization of its melt in air is investigated by X-ray diffraction (298 K, 329 reflections, R = 0.083, R{sub w} = 0.102). Crystals are hexagonal, a = 9.999(4) {angstrom}, c = 6.070(2) {angstrom}, Z = 2, space group P6{sub 3}/m. The structure is related to the CdTh(MoO{sub 4}){sub 3} type and consists of columns of Yb polyhedra (three-cap trigonal prisms) and of Re tetrahedra. The correlation of the structures of Yb(ReO{sub 4}){sub 3} and apatite is discussed.

  14. Spin Hall magnetoresistance in CoFe2O4sub>/Pt films

    SciTech Connect

    Wu, Hao; Qintong, Zhang; Caihua, Wan; Ali, Syed Shahbaz; Yuan, Zhonghui; You, Lu; Wang, Junling; Choi, Yongseong; Han, Xiufeng

    2015-05-13

    Pulse laser deposition and magnetron sputtering techniques have been employed to prepare MgO(001)//CoFe2O4sub>/Pt samples. Cross section transmission electron microscope results prove that the CoFe2O4sub> film epitaxially grew along (001) direction. X-ray magnetic circular dichroism results show that magnetic proximity effect in this sample is negligible. Magnetoresistance (MR) properties confirm that spin Hall MR (SMR) dominates in this system. Spin Hall effect-induced anomalous Hall voltage was also observed in this sample. Lastly, these results not only demonstrate the universality of SMR effect but also demonstrate the utility in spintronics of CoFe2O4sub> as a new type of magnetic insulator.

  15. Biodiesel production using lipase immobilized on epoxychloropropane-modified Fe3O4 sub-microspheres.

    PubMed

    Zhang, Qian; Zheng, Zhong; Liu, Changxia; Liu, Chunqiao; Tan, Tianwei

    2016-04-01

    Superparamagnetic Fe3O4 sub-microspheres with diameters of approximately 200 nm were prepared via a solvothermal method, and then modified with epoxychloropropane. Lipase was immobilized on the modified sub-microspheres. The immobilized lipase was used in the production of biodiesel fatty acid methyl esters (FAMEs) from acidified waste cooking oil (AWCO). The effects of the reaction conditions on the biodiesel yield were investigated using a combination of response surface methodology and three-level/three-factor Box-Behnken design (BBD). The optimum synthetic conditions, which were identified using Ridge max analysis, were as follows: immobilized lipase:AWCO mass ratio 0.02:1, fatty acid:methanol molar ratio 1:1.10, hexane:AWCO ratio 1.33:1 (mL/g), and temperature 40 °C. A 97.11% yield was obtained under these conditions. The BBD and experimental data showed that the immobilized lipase could generate biodiesel over a wide temperature range, from 0 to 40 °C. Consistently high FAME yields, in excess of 80%, were obtained when the immobilized lipase was reused in six replicate trials at 10 and 20 °C. PMID:26803008

  16. ATRX immunostaining predicts IDH and H3F3A status in gliomas.

    PubMed

    Ebrahimi, Azadeh; Skardelly, Marco; Bonzheim, Irina; Ott, Ines; Mühleisen, Helmut; Eckert, Franziska; Tabatabai, Ghazaleh; Schittenhelm, Jens

    2016-01-01

    Gliomas are the most frequent intraaxial CNS neoplasms with a heterogeneous molecular background. Recent studies on diffuse gliomas have shown frequent alterations in the genes involved in chromatin remodelling pathways such as α-thalassemia/mental-retardation-syndrome-X-linked gene (ATRX). Yet, the reliability of ATRX in predicting isocitrate dehydrogenase (IDH) and H3 histone, family 3A (H3F3A) mutations in gliomas, is unclear.We analysed the ATRX expression status by immunohistochemistry, in a large series of 1064 gliomas and analysed the results in correlation to IDH, H3F3A and loss of heterozygosity (LOH) 1p/19q status in these tumors. We also investigated the prognostic potential of ATRX concerning the clinical outcome of patients with diffuse gliomas.According to our results, loss of nuclear ATRX expression was accompanied with an astrocytic tumor lineage and a younger age of onset. ATRX loss in astrocytomas was also strongly associated with IDH1/2 and H3F3A mutation (p < 0.0001). Among 196 glial tumors with nuclear ATRX loss, 173 (89 %) had an IDH1 or IDH2 mutation. Among the remaining 23 cases (11 %) with ATRX loss and IDH wild type status, 7 cases had a H3F3A G34R mutation (3 %) and 2 cases had a H3F3A K27M mutation (1 %). ATRX retention in IDH1/2 mutant tumors was strongly associated with LOH 1p/19q and oligodendroglioma histology (p < 0.0001). We also confirmed the significant prognostic role of ATRX. Diffuse gliomas with ATRX loss (n = 137, median 1413 days, 95 % CI: 1065-1860 days) revealed a significantly better clinical outcome compared with tumors with ATRX retention (n = 335, median: 609, 95 % CI: 539-760 days, HR = 1.81, p < 0.0001).In conclusion, ATRX is a potential marker for prediction of IDH/H3F3A mutations and substratification of diffuse gliomas into survival relevant tumor groups. Such classification is of great importance for further clinical decision making especially concerning the therapeutic options

  17. Vacuum ultraviolet and near-infrared excited luminescence properties of Ca{sub 3}(PO{sub 4}){sub 2}:RE{sup 3+}, Na{sup +} (RE=Tb, Yb, Er, Tm, and Ho)

    SciTech Connect

    Zhang Jia; Wang Yuhua; Guo Linna; Zhang Feng; Wen Yan; Liu Bitao; Huang Yan

    2011-08-15

    Tb{sup 3+}, Yb{sup 3+}, Tm{sup 3+}, Er{sup 3+}, and Ho{sup 3+} doped Ca{sub 3}(PO{sub 4}){sub 2} were synthesized by solid-state reaction, and their luminescence properties were studied by spectra techniques. Tb{sup 3+}-doped samples can exhibit intense green emission under VUV excitation, and the brightness for the optimal Tb{sup 3+} content is comparable with that of the commercial Zn{sub 2}SiO{sub 4}:Mn{sup 2+} green phosphor. Under near-infrared laser excitation, the upconversion luminescence spectra of Yb{sup 3+}, Tm{sup 3+}, Er{sup 3+}, and Ho{sup 3+} doped samples demonstrate that the red, green, and blue tricolored fluorescence could be obtained by codoping Yb{sup 3+}-Ho{sup 3+}, Yb{sup 3+}-Er{sup 3+}, and Yb{sup 3+}-Tm{sup 3+} in Ca{sub 3}(PO{sub 4}){sub 2}, respectively. Good white upconversion emission with CIE chromaticity coordinates (0.358, 0.362) is achieved by quadri-doping Yb{sup 3+}-Tm{sup 3+}-Er{sup 3+}-Ho{sup 3+} in Ca{sub 3}(PO{sub 4}){sub 2}, in which the cross-relaxation process between Er{sup 3+} and Tm{sup 3+}, producing the {sup 1}D{sub 2}-{sup 3}F{sub 4} transition of Tm{sup 3+}, is found. The upconversion mechanisms are elucidated through the laser power dependence of the upconverted emissions and the energy level diagrams. - Graphical abstract: The CPO:0.25Tb{sup 3+}, 0.25Na{sup +} exhibits a comparable brightness to the commercial Zn{sub 2}SiO{sub 4}:Mn{sup 2+} upon 147 nm excitation. Good white light color is achieved in CPO:Yb{sup 3+}-Tm{sup 3+}-Er{sup 3+}-Ho{sup 3+} under 980 nm excitation. Highlights: > Ca{sub 3}(PO{sub 4}){sub 2}:Tb{sup 3+},Na{sup +} exhibits a comparable brightness with commercial Zn{sub 2}SiO{sub 4}:Mn{sup 2+}. > Red, green and blue colors are achieved in Yb{sup 3+}, Ho{sup 3+}, Er{sup 3+}, Tm{sup 3+} doped Ca{sub 3}(PO{sub 4}){sub 2}. > Good white emission is obtained in Yb{sup 3+}-Ho{sup 3+}-Er{sup 3+}-Tm{sup 3+} quadri-doped Ca{sub 3}(PO{sub 4}){sub 2}. > Ca{sub 3}(PO{sub 4}){sub 2}:Tb{sup 3+}, Yb{sup 3+}, Ho

  18. A high performance hybrid battery based on aluminum anode and LiFePO4sub> cathode

    SciTech Connect

    Sun, Xiao-Guang; Bi, Zhonghe; Liu, Hansan; Bridges, Craig A.; Paranthaman, Mariappan Parans; Dai, Sheng; Brown, Gilbert M.

    2015-12-07

    A unique battery hybrid utilizes an aluminum anode, a LiFePO4sub> cathode and an acidic ionic liquid electrolyte based on 1-ethyl-3-methylimidazolium chloride (EMImCl) and aluminum trichloride (AlCl 3) (EMImCl-AlCl 3, 1-1.1 in molar ratio) with or without LiAlCl4sub> is proposed. This hybrid ion battery delivers an initial high capacity of 160 mAh g-1 at a current rate of C/5. It also shows good rate capability and cycling performance.

  19. Theoretical Study of the Molecular and Electronic Structures of TiO4sub>H4sub>, Ti2O7H6, and Ti2O6H4sub>

    SciTech Connect

    Tsuchiya, Takashi; Whitten, Jerry L.

    2010-12-22

    State-of-the-art multistate configuration interaction (CI) calculations were performed for a series of titanium complexes, namely, TiO4sub>H4sub>, Ti2O7H6, and Ti2O6H4sub>, which were chosen to identify features present in titanium oxide nanoclusters and titanium dioxide surfaces. All electrons were included in the calculations, and transformation methods were employed to achieve high accuracy for the excitations of interest. The electronic structures of the ground and excited states are discussed, and excitation energies are reported for different molecular conformations. Of particular interest is the extent of localization of the electron-hole pair formed upon excitation from the oxygen 2p molecular orbitals. Singlet and triplet excited states were resolved, and energies of electronic states are reported as a function of molecular geometry.

  20. Structural and conductivity studies of CsK(SO{sub 4}){sub 0.32}(SeO{sub 4}){sub 0.68}Te(OH){sub 6}

    SciTech Connect

    Djemel, M.; Abdelhedi, M.; Dammak, M.; Kolsi, A.W.

    2012-12-15

    The compound CsK(SO{sub 4}){sub 0.32}(SeO{sub 4}){sub 0.68}Te(OH){sub 6} crystallizes in the monoclinic P2{sub 1}/n space group. It was analyzed, at room temperature, using X-ray diffractometer data. The main feature of these atomic arrangements is the coexistence of three and different anions (SO{sub 4}{sup 2-}, SeO{sub 4}{sup 2-} and TeO{sub 6}{sup 6-}groups) in the unit cell, connected by hydrogen bonds which make the building of the crystal. The thermal analysis of the title compound shows three distinct endothermal peaks at 435, 460 and 475 K. Complex impedance measurements are performed on this material as a function of both temperature and frequency. The electric conduction has been studied. The temperature dependence on the conductivity indicates that the sample became an ionic conductor at high temperature. - Graphical abstract: Projection of crystal structure CsK(SO{sub 4}){sub 0.32}(SeO{sub 4}){sub 0.68}Te(OH){sub 6} on the ab plane. Highlights: Black-Right-Pointing-Pointer We have studied the results of the crystal structure of the new mixed compound. Black-Right-Pointing-Pointer We have characterized the phase transition observed in DSC curve. Black-Right-Pointing-Pointer The protonic conduction in our material is probably due to a hopping mechanism.

  1. Electron paramagnetic resonance spectra and structures of Cu(C sub 2 H sub 4 ), Cu(C sub 2 H sub 4 ) sub 2 , and Cu(C sub 2 H sub 4 ) sub 3 in hydrocarbon matrices

    SciTech Connect

    Howard, J.A.; Joly, H.A.; Mile, B. )

    1990-02-22

    Two mononuclear {pi}-complexes, Cu(C{sub 2}H{sub 4}) and Cu(C{sub 2}H{sub 4}){sub 2}, have been positively identified by EPR spectroscopy from reaction of Cu atoms and ethylene at 77 K in inert hydrocarbon matrices on a rotating cryostat. The spectra of these copper(O) complexes are consistent with dative bonding for both species and with a C{sub 2v} structure for Cu(C{sub 2}H{sub 4}) and a D{sub 2h} structure for Cu(C{sub 2}H{sub 4}){sub 2}. Spectra of Cu({sup 13}CH{sub 2}CH{sub 2}) and Cu({sup 13}CH{sub 2}CH{sub 2}){sub 2} are consistent with these assignments. A third complex is formed in both adamantane and cyclohexane that could be Cu(C{sub 2}H{sub 4}){sub 2} with a structure other than D{sub 2h} but is more likely to be the mononuclear trisligand complex Cu(C{sub 2}H{sub 4}){sub 3} with a D{sub 3h} structure. In the absence of a well-resolved isotropic spectrum of Cu({sup 13}CH{sub 2}CH{sub 2}){sub 3}, this assignment must however be taken as tentative.

  2. A new three-dimensional cobalt phosphate: Co{sub 5}(OH{sub 2}){sub 4}(HPO{sub 4}){sub 2}(PO{sub 4}){sub 2}

    SciTech Connect

    Han Zhangang . E-mail: hanzg116@yahoo.com.cn; Tian Aixiang; Peng Jun . E-mail: jpeng@nenu.edu.cn; Zhai Xueliang

    2006-10-15

    A three-dimensional (3D) cobalt phosphate: Co{sub 5}(OH{sub 2})PO{sub 4}){sub 2}(PO{sub 4}){sub 2} (1), has been synthesized by hydrothermal reaction and characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and magnetic techniques. The title compound is a template free cobalt phosphate. Compound 1 exhibits a complex net architecture based on edge- and corner-sharing of CoO{sub 6} and PO{sub 4} polyhedra. The magnetic susceptibility measurements indicated that the title compound obeys Curie-Weiss behavior down to a temperature of 17 K at which an antiferromagnetic phase transition occurs. - Graphical abstract: A 3D cobalt phosphate with a neutral framework: Co{sub 5}(OH{sub 2}){sub 4}(HPO{sub 4}){sub 2}(PO{sub 4}){sub 2} (1), has been synthesized and characterized. Compound 1 exhibits a complex net architecture based on edge- and corner-sharing of CoO{sub 6} and PO{sub 4} polyhedra. Its magnetic property was researched.

  3. Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber

    SciTech Connect

    Amole, C.; Ardid, M.; Asner, David M.; Baxter, D.; Behnke, E.; Bhattacharjee, P. S.; Borsodi, H.; Bou-Cabo, M.; Brice, S. J.; Broemmelsiek, D.; Clark, K.; Collar, J. I.; Cooper, P. S.; Crisler, M.; Dahl, C. E.; Daley, S.; Das, Madhusmita; Debris, F.; Dhungana, N.; Farine, J.; Felis, I.; Filgas, R.; Fines-Neuschild, M.; Girard, Francoise; Giroux, G.; Hai, M.; Hall, Jeter C.; Harris, O.; Jackson, C. M.; Jin, M.; Krauss, C. B.; Lafreniere, M.; Laurin, M.; Lawson, I.; Levine, I.; Lippincott, W. H.; Mann, E.; Martin, J. P.; Maurya, D.; Mitra, Pitam; Neilson, R.; Noble, A. J.; Plante, A.; Podviianiuk, R. B.; Priya, S.; Robinson, A. E.; Ruschman, M.; Scallon, O.; Seth, S.; Sonnenschein, Andrew; Starinski, N.; Stekl, I.; Vazquez-Jauregui, E.; Wells, J.; Wichoski, U.; Zacek, V.; Zhang, J.

    2015-06-12

    New data are reported from the operation of a 2-liter C3F8 bubble chamber in the 2100 meter deep SNOLAB underground laboratory, with a total exposure of 211.5 kg-days at four different recoil energy thresholds ranging from 3.2 keV to 8.1 keV. These data show that C3F8 provides excellent electron recoil and alpha rejection capabilities at very low thresholds, including the rst observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with signicant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.

  4. Homogeneous and Heterogeneous Reaction Mechanisms in CH3F-O2 Inductively Coupled Plasmas

    NASA Astrophysics Data System (ADS)

    Donnelly, Vincent M.; Karakas, Erdinc; Kaler, Sanbir; Lou, Qiaowei; Economou, Demetre J.

    2013-09-01

    CH3F/O2 containing plasmas are used in selective Si3N4 etching over Si or SiO2. Fundamental plasma studies in these gas mixtures are scarce. In this work, optical emission rare gas actinometry and a global chemistry model were employed to study inductively couple plasmas in CH3F/O2 gas mixtures. For constant CH3F and O2 flow rates, the absolute H, F and O atom densities increased linearly with power. The feedstock gas was highly dissociated and most of the fluorine and oxygen was contained in reaction products HF, CO, CO2, H2O and OH. Measured number densities as a function of O2 addition to CH3F/O2 changed abruptly for H, O, and particularly F atoms (factor of 4) at 48% O2 A corresponding transition was also observed in electron density, electron temperature and gas temperature, as well as in C, CF and CH optical emission. These abrupt transitions were attributed to the reactor wall reactivity, changing from a polymer-coated surface to a polymer-free surface, and vice-versa, as the O2 content in the feed gas crossed 48%. Homogeneous chemistry dominates above 48% O2; a kinetic model with no adjustable parameters is in excellent agreement with the absolute F and H and relative HF number density dependence on power and pressure. CH3F/O2 containing plasmas are used in selective Si3N4 etching over Si or SiO2. Fundamental plasma studies in these gas mixtures are scarce. In this work, optical emission rare gas actinometry and a global chemistry model were employed to study inductively couple plasmas in CH3F/O2 gas mixtures. For constant CH3F and O2 flow rates, the absolute H, F and O atom densities increased linearly with power. The feedstock gas was highly dissociated and most of the fluorine and oxygen was contained in reaction products HF, CO, CO2, H2O and OH. Measured number densities as a function of O2 addition to CH3F/O2 changed abruptly for H, O, and particularly F atoms (factor of 4) at 48% O2 A corresponding transition was also observed in electron density

  5. 'Pseudo-proper' ferroelectric phase transitions in oxyfluoride K3WO3F3

    NASA Astrophysics Data System (ADS)

    Ivliev, M. P.; Misyul, S. V.; Molokeev, M. S.; Sakhnenko, V. P.

    2014-06-01

    Based on the structural data on the phases of cryolite (ordered perovskite) K3WO3F3, we develop a statistical model, which allows to describe the sequence of phase transitions observed in this compound using a unified approach. According to the model, the crystal possesses two structural subsystems: the K cations located in the octahedral positions and the WO3F3 octahedra in positions alternating with K cations. In the symmetric (cubic) phase, each subsystem can be found in one of the eight states. At decreasing temperature, an orientational phase transition in the subsystem of octahedra occurs first, followed by a phase transition to the low-temperature phase, caused by the loss of stability with respect to the ordering in the K cation subsystem. We find that the electric polarization occurs as pseudoproper and discuss the mechanisms of formation of the phase states.

  6. Collisional narrowing in the optically pumped CH3OH and CH3F lasers

    NASA Technical Reports Server (NTRS)

    Lawandy, N. M.; Koepf, G. A.

    1982-01-01

    The gain linewidth of the optically pumped CH3F laser is observed to narrow and rebroaden with the addition of He. In addition, the same effect is observed in the CH3OH laser with the addition of the polyatomic buffer gases SF6 and CS2. These results offer conclusive evidence of the Dicke narrowing phenomena in these inverted pure rotational transitions. The effect is observed using a high harmonic mixing technique in a Schottky barrier diode.

  7. Structural determinants of HIV-1 Vif susceptibility and DNA binding in APOBEC3F

    PubMed Central

    Siu, Karen K.; Sultana, Azmiri; Azimi, Farshad C.; Lee, Jeffrey E.

    2016-01-01

    The human APOBEC3 family of DNA cytosine deaminases serves as a front-line intrinsic immune response to inhibit the replication of diverse retroviruses. APOBEC3F and APOBEC3G are the most potent factors against HIV-1. As a countermeasure, HIV-1 viral infectivity factor (Vif) targets APOBEC3s for proteasomal degradation. Here, we report the crystal structure of the Vif-binding domain in APOBEC3F and a novel assay to assess Vif-APOBEC3 binding. Our results point to an amphipathic surface that is conserved in APOBEC3s as critical for Vif susceptibility in APOBEC3F. Electrostatic interactions likely mediate Vif binding. Moreover, structure-guided mutagenesis reveals a straight ssDNA-binding groove distinct from the Vif-binding site, and a novel ‘aromatic switch’ is proposed to explain DNA substrate specificities across the APOBEC3 family. This study opens new lines of inquiry that will further our understanding of APOBEC3-mediated retroviral restriction and provides an accurate template for structure-guided development of inhibitors targeting the APOBEC3-Vif axis. PMID:24185281

  8. Studies of carcinogenicity of sodium chlorite in B6C3F1 mice

    SciTech Connect

    Yokose, Y.; Uchida, K.; Nakae, D.; Shiraiwa, K.; Yamamoto, K.; Konishi, Y.

    1987-12-01

    The carcinogenic activities of sodium chlorite in B6C3F1 mice were examined. Sodium chlorite was given at concentration of 0 (control), 0.025% (low dose), or 0.05% (high dose) in the drinking water of 150 female and 150 male mice for 80 weeks, after which time the animals were returned to distilled water without sodium chlorite. All mice were sacrificed 85 weeks from the beginning of the experiment. The incidence of tumor-bearing animals was 32% (control), 34% (low dose), and 26% (high dose) in female mice, and 46% (control), 57% (low dose), and 53% (high dose) in male mice. The types and incidence of neoplasms that occurred frequently in each group of both sexes were similar to those observed spontaneously in B6C3F1 mice. The incidence of lymphomas/leukemias in the high dose group of females (2%), however, was lower than that in the control group (15%). Furthermore, the incidence of pulmonary adenomas in the high dose group of males (12%) was higher than that in the control group (0%), but neither dose-related increases in the adenoma incidences nor increased incidences of the adenocarcinomas were observed. These results indicated no clear evidence of a carcinogenic potential of sodium chlorite in B6C3F1 mice.

  9. The factor XIIa blocking antibody 3F7: a safe anticoagulant with anti-inflammatory activities.

    PubMed

    Worm, Marie; Köhler, Elodie C; Panda, Rachita; Long, Andy; Butler, Lynn M; Stavrou, Evi X; Nickel, Katrin F; Fuchs, Tobias A; Renné, Thomas

    2015-10-01

    The plasma protein factor XII (FXII) is the initiating protease of the procoagulant and proinflammatory contact system. FXII activates both the bradykinin (BK) producing kallikrein-kinin system and the intrinsic pathway of coagulation. Contact with negatively charged surfaces induces auto-activation of zymogen FXII that results in activated FXII (FXIIa). Various in vivo activators of FXII have been identified including heparin, misfolded protein aggregates, nucleic acids and polyphosphate. Murine models have established a central role of FXII in arterial and venous thromboembolic diseases. Despite the central function of FXII in pathologic thrombosis, its deficiency does not impair hemostasis in animals or humans. The selective role of FXIIa in thrombosis, but not hemostasis, offers an exciting novel strategy for safe anticoagulation based on interference with FXIIa. We have generated the recombinant fully human FXIIa-blocking antibody 3F7, which abolished FXIIa enzymatic activity and prevented thrombosis in a cardiopulmonary bypass system in large animals, in the absence of increased therapy-associated bleeding. Furthermore, 3F7 also interfered with BK-driven edema in the severe swelling disorder hereditary angioedema (HAE) type III. Taken together, targeting FXIIa with 3F7 appears to be a promising approach to treat edema disorders and thrombosis. PMID:26605293

  10. The factor XIIa blocking antibody 3F7: a safe anticoagulant with anti-inflammatory activities

    PubMed Central

    Worm, Marie; Köhler, Elodie C.; Panda, Rachita; Long, Andy; Butler, Lynn M.; Stavrou, Evi X.; Nickel, Katrin F.; Fuchs, Tobias A.

    2015-01-01

    The plasma protein factor XII (FXII) is the initiating protease of the procoagulant and proinflammatory contact system. FXII activates both the bradykinin (BK) producing kallikrein-kinin system and the intrinsic pathway of coagulation. Contact with negatively charged surfaces induces auto-activation of zymogen FXII that results in activated FXII (FXIIa). Various in vivo activators of FXII have been identified including heparin, misfolded protein aggregates, nucleic acids and polyphosphate. Murine models have established a central role of FXII in arterial and venous thromboembolic diseases. Despite the central function of FXII in pathologic thrombosis, its deficiency does not impair hemostasis in animals or humans. The selective role of FXIIa in thrombosis, but not hemostasis, offers an exciting novel strategy for safe anticoagulation based on interference with FXIIa. We have generated the recombinant fully human FXIIa-blocking antibody 3F7, which abolished FXIIa enzymatic activity and prevented thrombosis in a cardiopulmonary bypass system in large animals, in the absence of increased therapy-associated bleeding. Furthermore, 3F7 also interfered with BK-driven edema in the severe swelling disorder hereditary angioedema (HAE) type III. Taken together, targeting FXIIa with 3F7 appears to be a promising approach to treat edema disorders and thrombosis. PMID:26605293

  11. Dark Matter Limits From a 2L C3F8 Filled Bubble Chamber

    SciTech Connect

    Robinson, Alan Edward

    2015-12-01

    The PICO-2L C3F8 bubble chamber search forWeakly Interacting Massive Particle (WIMP) dark matter was operated in the SNOLAB underground laboratory at the same location as the previous CF3I lled COUPP-4kg detector. Neutron calibrations using photoneutron sources in C3F8 and CF3I lled calibration bubble chambers were performed to verify the sensitivity of these target uids to dark matter scattering. This data was combined with similar measurements using a low-energy neutron beam at the University of Montreal and in situ calibrations of the PICO-2L and COUPP-4kg detectors. C3F8 provides much greater sensitivity to WIMP-proton scattering than CF3I in bubble chamber detectors. PICO-2L searched for dark matter recoils with energy thresholds below 10 keV. Radiopurity assays of detector materials were performed and the expected neutron recoil background was evaluated to be 1.6+0:3

  12. Growth, structure and optical properties of nonlinear optical crystal BaZnBO3F

    NASA Astrophysics Data System (ADS)

    Xia, Mingjun; Li, R. K.

    2016-01-01

    Nonlinear optical (NLO) crystal BaZnBO3F (BZBF) with the size of about 20×20×0.5 mm3 is obtained from BaF2-NaF flux, and single crystal X-ray diffraction reveals that it belongs to space group P 6 ̅ with cell parameters of a=5.1045(6) Å, c=4.3116(10) Å and Z=1. In the structure of BZBF, the BO3 planar triangles are interconnected through O atoms from ZnO3F2 trigonal bipyramid to form (Zn3B3O6F6) twelve-membered rings (12-MRs), then the layers which are built with condensation from 12-MRs at ab plane, are further linked by the apical F from ZnO3F2 to form three dimensional framework along the c direction. The title crystal exhibits high transmittance in the range of 300-3000 nm with a UV transmission cutoff at 223 nm according to transmission spectra. Powder SHG tests indicate that the effective NLO coefficient of BZBF crystal is about 2.8 times that of KH2PO4 (KDP) crystal due to perfect alignment of the BO3 groups.

  13. Dark matter limits from a 2L C3F8 filled bubble chamber

    NASA Astrophysics Data System (ADS)

    Robinson, Alan Edward

    The PICO-2L C3F8 bubble chamber search for Weakly Interacting Massive Particle (WIMP) dark matter was operated in the SNOLAB underground laboratory at the same location as the previous CF3I filled COUPP-4kg detector. Neutron calibrations using photoneutron sources in C3F8 and CF3I filled calibration bubble chambers were performed to verify the sensitivity of these target fluids to dark matter scattering. This data was combined with similar measurements using a low-energy neutron beam at the University of Montreal and in situ calibrations of the PICO-2L and COUPP-4kg detectors. C3F 8 provides much greater sensitivity to WIMP-proton scattering than CF 3I in bubble chamber detectors. PICO-2L searched for dark matter recoils with energy thresholds below 10 keV. Radiopurity assays of detector materials were performed and the expected neutron recoil background was evaluated to be 1.6 +0.3-0.9 single bubble events during the 211.5 kg-day exposure. Twelve single bubble dark matter candidate events were observed. These events were not uniformly distributed in time, and were likely caused by particulates in the active volume. Despite this background, PICO-2L sets a world-leading upper limit to the WIMP-proton spin dependent scattering cross-section.

  14. Nasal Tumorigenesis in B6C3F1 Mice Following Intraperitoneal Diethylnitrosamine.

    PubMed

    Chen, Yung-Ju; Wallig, Matthew A; Jeffery, Elizabeth H

    2016-08-01

    Diethylnitrosamine (DEN) is a chemical broadly used in animal models as a hepatocarcinogen, reported to also cause pulmonary neoplasms in mice. The original objective was to evaluate the impact of a Western diet with or without 10% broccoli on DEN-induced on liver cancer. We administered DEN (45 mg/kg) intraperitoneally to young adult male B6C3F1 mice by 6 weekly injections and evaluated liver cancer 6 months after the DEN treatments. Here, we report unexpected primary tumorigenesis in nasal epithelium, independent of dietary treatment. More than 50% of DEN-treated B6C3F1 mice developed nasal neoplasm-related lesions, not reported previously in the literature. Only one of these neoplasms was visible externally prior to postmortem examination. Intraperitoneal DEN treatment used as a model for liver cancer can have a carcinogenic effect on the nasal epithelium in B6C3F1 mice, which should be carefully monitored in future liver cancer studies. PMID:27207684

  15. Nuclear import of APOBEC3F-labeled HIV-1 preintegration complexes.

    PubMed

    Burdick, Ryan C; Hu, Wei-Shau; Pathak, Vinay K

    2013-12-01

    Human cytidine deaminases APOBEC3F (A3F) and APOBEC3G (A3G) are host factors that incorporate into virions and restrict virus replication. We labeled HIV-1 particles with yellow fluorescent protein (YFP)-tagged APOBEC3 proteins and examined their association with preintegration complexes (PICs) in infected cells. Labeling of PICs with A3F-YFP, and to a lesser extent A3G-YFP, could be used to visualize PICs in the nuclei, which was dependent on nuclear pore protein Nup153 but not TNPO3. We show that reverse transcription is not required for nuclear import of PICs, indicating that a viral core uncoating event associated with reverse transcription, and the central DNA flap that forms during reverse transcription, are not required for nuclear import. We also quantify association of cytoplasmic PICs with nuclear envelope (NE) and report that capsid mutations that increase or decrease core stability dramatically reduce NE association and nuclear import of PICs. In addition, we find that nuclear PICs remain close to the NE and are not distributed throughout the nuclei. These results provide tools for tracking retroviral PICs in infected cells and reveal insights into HIV-1 replication. PMID:24248339

  16. The Seasonal and Interannual Variability of the Budgets of N2O and CCl3F

    NASA Technical Reports Server (NTRS)

    Wong, Sun; Prather, Michael J.; Rind, David H.

    1999-01-01

    The 6-year wind archives from the Goddard Institute for Space Studies/Global Climate-Middle Atmosphere Model (GISS/GCMAM) were in- put to the GISS/Harvard/Irvine Chemical Transport Model (G/H/I CTM) to study the seasonal and interannual variability of the budgets and distributions of nitrous oxide (N2O) and trichlorofluoromethane (CCl3F), with the corresponding chemical loss frequencies recycled and boundary conditions kept unchanged from year to year. The effects of ozone feedback and quasi-biennial oscillation (QBO) were not included. However, the role of circulation variation in driving the lifetime variability is investigated. It was found that the global loss rates of these tracers are related to the extratropical planetary wave activity, which drives the tropical upward mass flux. For N2O, a semiannual signal in the loss rate variation is associated with the interhemispheric asymmetry in the upper stratospheric wave activity. For CCl3F, the semiannual signal is weaker, associated with the comparatively uniform wave episodes in the lower stratosphere. The loss rates lag behind the wave activity by about 1-2 months. The interannual variation of the GCM generated winds drives the interannual variation of the annually averaged lifetime. The year-to-year variations of the annually averaged lifetimes can be about 3% for N2O and 4% for CCl3F.

  17. Semaphorin-3F functions as a tumor suppressor in colorectal cancer due to regulation by DNA methylation

    PubMed Central

    Gao, Xuesong; Tang, Chong; Shi, Wen; Feng, Shichun; Qin, Weiyan; Jiang, Tian; Sun, Yongqiang

    2015-01-01

    Semaphorin-3F (SEMA3F) is a member of the class III semaphorin family, and is seen as a candidate tumor suppressor gene. The aims of this study were to evaluate the effect of SEMA3F in colorectal cancer (CRC) patients, and to explore the mechanism for that SEMA3F suppresses tumor progression and metastasis. The expression levels of SEMA3F in the colorectal cancer tissues and corresponding non-tumor colorectal tissues were determined by Western blotting and real-time quantitative PCR (qRT-PCR). In addition, we evaluate the effects of SEMA3F on CRC cell migration and colony formation in vitro. Subsequently, quantitative methylation-specific PCR (qMSP) was used to detect the DNA methylation status in the CpG islands of SEMA3F gene promoter in normal colon and colorectal cancer cell lines, colorectal cancer tissues and corresponding non-tumor colorectal tissues. We found that SEMA3F was downregulated in the protein (P < 0.01) and mRNA (P < 0.001) levels in CRC tissues as compared to matched adjacent non-tumor tissues. Moreover, MSP assay showed high levels of SEMA3F gene promoter methylation in the CpG islands in some CRC cell lines and tissue samples. Furthermore, SEMA3F expression was reactivated in CRC cell lines after treatment with 5-Aza-CdR, demethylation of SW620 cells resulted in cell colony formation and invasion inhibition. These findings suggest DNA methylation of promoter CpG island-mediated silencing of the tumor suppressor SEMA3F gene plays an important role in the carcinogenesis of CRC. PMID:26722466

  18. A facile solvothermal synthesis of octahedral Fe3O4sub> nanoparticles

    SciTech Connect

    DuChene, Joseph S.; Qiu, Jingjing; Graham, Jeremy O.; Engelhard, Mark H.; Cao, Guixin; Gai, Zheng; Wei, Wei David; Ooi, Frances

    2015-01-26

    Anisotropic Fe3O4sub> octahedrons are obtained via a simple solvothermal synthesis with appropriate sizes for various technological applications. Here, a complete suite of materials characterization methods confirms the magnetite phase for these structures, which exhibit substantial saturation magnetization and intriguing morphologies for a wide range of applications.

  19. New mixed-valence chromium structure type: NH{sub 4}Cr(CrO{sub 4}){sub 2}

    SciTech Connect

    Casari, Barbara M. . E-mail: casari@chem.gu.se; Wingstrand, Erica; Langer, Vratislav

    2006-01-15

    Synthesis and crystal structure of a new structure type of mixed Cr(III)/Cr(VI) chromates is reported. NH{sub 4}Cr(CrO{sub 4}){sub 2} was prepared from CrO{sub 3} in the presence of (NH{sub 4}){sub 2}Ce(NO{sub 3}){sub 6}. Since this is the first preparation of mixed valence ternary chromium oxides from aqueous solution, a reaction pathway for this synthesis is suggested. The crystal structure of NH{sub 4}Cr(CrO{sub 4}){sub 2} has been determined from three-dimensional X-ray data collected at low temperature, 173K. The structure belongs to the orthorhombic space group Pnma, with a=14.5206(10), b=5.4826(4), c=8.7041(7)A and Z=4. The title compound consists of corner-sharing chromium(III) octahedra and chromium(VI) tetrahedra forming a three-dimensional network with the composition [Cr(CrO{sub 4}){sub 2}]{sub n}{sup n-}, containing channels in which zigzag rows of ammonium ions balance the net charge.

  20. Regulation of mTOR Signaling by Semaphorin 3F-Neuropilin 2 Interactions In Vitro and In Vivo

    PubMed Central

    Nakayama, Hironao; Bruneau, Sarah; Kochupurakkal, Nora; Coma, Silvia; Briscoe, David M.; Klagsbrun, Michael

    2015-01-01

    Semaphorin 3F (SEMA3F) provides neuronal guidance cues via its ability to bind neuropilin 2 (NRP2) and Plexin A family molecules. Recent studies indicate that SEMA3F has biological effects in other cell types, however its mechanism(s) of function is poorly understood. Here, we analyze SEMA3F-NRP2 signaling responses in human endothelial, T cell and tumor cells using phosphokinase arrays, immunoprecipitation and Western blot analyses. Consistently, SEMA3F inhibits PI-3K and Akt activity, and responses are associated with the disruption of mTOR/rictor assembly and mTOR-dependent activation of the RhoA GTPase. We also find that the expression of vascular endothelial growth factor, as well as mTOR-inducible cellular activation responses and cytoskeleton stability are inhibited by SEMA3F-NRP2 interactions in vitro. In vivo, local and systemic overproduction of SEMA3F reduces tumor growth in NRP2-expressing xenografts. Taken together, SEMA3F regulates mTOR signaling in diverse human cell types, suggesting that it has broad therapeutic implications. PMID:26156437

  1. The axon guidance molecule semaphorin 3F is a negative regulator of tumor progression and proliferation in ileal neuroendocrine tumors

    PubMed Central

    Vercherat, Cécile; Blanc, Martine; Lepinasse, Florian; Gadot, Nicolas; Couderc, Christophe; Poncet, Gilles; Walter, Thomas; Joly, Marie-Odile; Hervieu, Valérie; Scoazec, Jean-Yves; Roche, Colette

    2015-01-01

    Gastro-intestinal neuroendocrine tumors (GI-NETs) are rare neoplasms, frequently metastatic, raising difficult clinical and therapeutic challenges due to a poor knowledge of their biology. As neuroendocrine cells express both epithelial and neural cell markers, we studied the possible involvement in GI-NETs of axon guidance molecules, which have been shown to decrease tumor cell proliferation and metastatic dissemination in several tumor types. We focused on the role of Semaphorin 3F (SEMA3F) in ileal NETs, one of the most frequent subtypes of GI-NETs. SEMA3F expression was detected in normal neuroendocrine cells but was lost in most of human primary tumors and all their metastases. SEMA3F loss of expression was associated with promoter gene methylation. After increasing endogenous SEMA3F levels through stable transfection, enteroendocrine cell lines STC-1 and GluTag showed a reduced proliferation rate in vitro. In two different xenograft mouse models, SEMA3F-overexpressing cells exhibited a reduced ability to form tumors and a hampered liver dissemination potential in vivo. This resulted, at least in part, from the inhibition of mTOR and MAPK signaling pathways. This study demonstrates an anti-tumoral role of SEMA3F in ileal NETs. We thus suggest that SEMA3F and/or its cellular signaling pathway could represent a target for ileal NET therapy. PMID:26447612

  2. Regulation of mTOR Signaling by Semaphorin 3F-Neuropilin 2 Interactions In Vitro and In Vivo.

    PubMed

    Nakayama, Hironao; Bruneau, Sarah; Kochupurakkal, Nora; Coma, Silvia; Briscoe, David M; Klagsbrun, Michael

    2015-01-01

    Semaphorin 3F (SEMA3F) provides neuronal guidance cues via its ability to bind neuropilin 2 (NRP2) and Plexin A family molecules. Recent studies indicate that SEMA3F has biological effects in other cell types, however its mechanism(s) of function is poorly understood. Here, we analyze SEMA3F-NRP2 signaling responses in human endothelial, T cell and tumor cells using phosphokinase arrays, immunoprecipitation and Western blot analyses. Consistently, SEMA3F inhibits PI-3K and Akt activity, and responses are associated with the disruption of mTOR/rictor assembly and mTOR-dependent activation of the RhoA GTPase. We also find that the expression of vascular endothelial growth factor, as well as mTOR-inducible cellular activation responses and cytoskeleton stability are inhibited by SEMA3F-NRP2 interactions in vitro. In vivo, local and systemic overproduction of SEMA3F reduces tumor growth in NRP2-expressing xenografts. Taken together, SEMA3F regulates mTOR signaling in diverse human cell types, suggesting that it has broad therapeutic implications. PMID:26156437

  3. Genetic Identification of SEMA3F as an Antilymphangiogenic Metastasis Suppressor Gene in Head and Neck Squamous Carcinoma.

    PubMed

    Doçi, Colleen L; Mikelis, Constantinos M; Lionakis, Michail S; Molinolo, Alfredo A; Gutkind, J Silvio

    2015-07-15

    Head and neck squamous cell carcinomas (HNSCC) often metastasize to locoregional lymph nodes, and lymph node involvement represents one of the most important prognostic factors of poor clinical outcome. HNSCCs are remarkably lymphangiogenic and represent a clear example of a cancer that utilizes the lymphatic vasculature for malignant dissemination; however, the molecular mechanisms underlying lymphangiogenesis in HNSCC is still poorly understood. Of interest, we found that an axon guidance molecule, Semaphorin 3F (SEMA3F), is among the top 1% underexpressed genes in HNSCC, and that genomic loss of SEMA3F correlates with increased metastasis and decreased survival. SEMA3F acts on its coreceptors, plexins and neuropilins, among which neuropilin-2 (NRP2) is highly expressed in lymphatic endothelial cells (LEC) but not in oral epithelium and most HNSCCs. We show that recombinant SEMA3F promotes LEC collapse and potently inhibits lymphangiogenesis in vivo. By reconstituting all possible plexin and neuropilin combinations, we found that SEMA3F acts through multiple receptors, but predominantly requires NRP2 to signal in LECs. Using orthotopic HNSCC metastasis mouse models, we provide direct evidence that SEMA3F re-expression diminishes lymphangiogenesis and lymph node metastasis. Furthermore, analysis of a large tissue collection revealed that SEMA3F is progressively lost during HNSCC progression, concomitant with increased tumor lymphangiogenesis. SEMA3F is localized to 3p21, an early and frequently deleted locus in HNSCC and many other prevalent human malignancies. Thus, SEMA3F may represent an antilymphangiogenic metastasis suppressor gene widely lost during cancer progression, hence serving as a prognostic biomarker and an attractive target for therapeutic intervention to halt metastasis. PMID:25952650

  4. Determination of CCl 3F and CCl 2F 2 in seawater and air

    NASA Astrophysics Data System (ADS)

    Bullister, J. L.; Weiss, R. F.

    1988-05-01

    An improved analytical technique has been developed for the rapid and accurate shipboard measurement of two anthropogenically produced chlorofluorocarbons (CFCs), CCl 3F (F-11) and CCl 2F 2 (F-12) in air and seawater. Gas samples (dry air or standard) are injected into a stream of purified gas and then concentrated in a low temperature trap. Seawater samples collected in oceanographic Niskin bottles are transferred into glass syringes for storage until analysis. An aliquot of approximately 30 cm 3 of seawater is introduced into a glass stripping chamber where the dissolved gases are purged with purified gas, and the evolved CFCs are concentrated in the same cold trap. The trap is subsequently isolated and heated, and the CFCs are automatically transferred by a stream of carrier gas into a precolumn and then a chromatographic separating column. The CCl 3F and CCl 2F 2 peaks are detected by an electron capture detector (ECD) and their areas are integrated digitally. CFC amounts are calculated using fitted calibration curves, generated by injection of various multiple aliquots of gas standard containing known concentrations of CFCs. Preliminary concentration values for these compounds are printed at the completion of each analysis. Total analysis time for air and water samples is < 10 min, allowing detailed vertical profiles of the concentrations of these compounds in the water column and concentrations in the overlying atmosphere to be determined within a few hours of the completion of a hydrographic station. Typical relative standard deviations for analyses of CCl 3F and CCl 2F 2 in near-surface seawater containing equilibrium levels of these compounds are approximately 1%. Limits of detection for both compounds in 30 cm 3 seawater samples are about 0.005 × 10 -12 mol kg -1.

  5. FORMALDEHYDE DENSITOMETRY OF GALACTIC STAR-FORMING REGIONS USING THE H{sub 2}CO 3{sub 12}-3{sub 13} AND 4{sub 13}-4{sub 14} TRANSITIONS

    SciTech Connect

    McCauley, Patrick I.; Mangum, Jeffrey G.; Wootten, Alwyn

    2011-11-20

    We present Green Bank Telescope observations of the 3{sub 12}-3{sub 13} (29 GHz) and 4{sub 13}-4{sub 14} (48 GHz) transitions of the H{sub 2}CO molecule toward a sample of 23 well-studied star-forming regions. Analysis of the relative intensities of these transitions can be used to reliably measure the densities of molecular cores. Adopting kinetic temperatures from the literature, we have employed a large velocity gradient (LVG) model to derive the average hydrogen number density (n(H{sub 2})) within a 16'' beam toward each source. Densities in the range of 10{sup 5.5}-10{sup 6.5} cm{sup -3} and ortho-formaldehyde column densities per unit line width between 10{sup 13.5} and 10{sup 14.5} cm{sup -2} (km s{sup -1}){sup -1} are found for most objects, in general agreement with existing measurements. A detailed analysis of the advantages and limitations to this densitometry technique is also presented. We find that H{sub 2}CO 3{sub 12}-3{sub 13}/4{sub 13}-4{sub 14} densitometry proves to be best suited to objects with T{sub K} {approx}> 100 K, above which the H{sub 2}CO LVG models become relatively independent of kinetic temperature. This study represents the first detection of these H{sub 2}CO K-doublet transitions in all but one object in our sample. The ease with which these transitions were detected, coupled with their unique sensitivity to spatial density, makes them excellent monitors of density in molecular clouds for future experiments. We also report the detection of the 9{sub 2}-8{sub 1} A {sup -} (29 GHz) transition of CH{sub 3}OH toward six sources.

  6. Synthesis and conductivities of sulfate/selenate phases related to nasicon: Na[sub x]M[prime](III)[sub 2[minus]x](SO[sub 4])[sub 3[minus]y](SeO[sub 4])[sub y

    SciTech Connect

    Slater, P.R.; Greaves, C. )

    1993-11-01

    The synthesis of Na containing Nasicon-type phases of the form Na[sub x]M[prime](II)[sub x]M[double prime](III)[sub 2[minus]x](SO[sub 4])[sub 3[minus]y](SeO[sub 4])[sub y] (M[prime] = Mg, Zn, Cd, Mn; M[double prime] = Al, Cr, Fe, In, Yb; 0 [le] x [le] 1.75; 0 [le] y [le] 3) is reported. The conductivities of a range of samples have been measured, with the highest value observed at 200[degrees]C being 2 x 10[sup [minus]4] [Omega][sup [minus]1] cm[sup [minus]1] for Na[sub 1.75]Mg[sub 1.75]Cr[sub 0.25](SO[sub 4])[sub 3]. The range of x for which single phase samples are observed depends on the nature of M[prime] and M[double prime], and on the value of y. Attempts to increase the Na content, and so increase the conductivity, by partially substituting the (S, Se)O[sub 4] groups by PO[sub 4] or SiO[sub 4] have proven unsuccessful.

  7. Magnetic structure of the antiferromagnetic Kondo lattice compounds CeRhAl4sub>Si2 and CeIrAl4sub>Si2

    SciTech Connect

    Ghimire, N. J.; Calder, S.; Janoschek, M.; Bauer, E. D.

    2015-06-01

    In this article, we have investigated the magnetic ground state of the antiferromagnetic Kondo-lattice compounds CeMAl4sub>Si2(M = Rh, Ir) using neutron powder diffraction. Although both of these compounds show two magnetic transitions TN1 and TN2 in the bulk properties measurements, evidence for magnetic long-range order was only found below the lower transition TN2. Analysis of the diffraction profiles reveals a commensurate antiferromagnetic structure with a propagation vector k = (0, 0, 1/2). The magnetic moment in the ordered state of CeRhAl4sub>Si2 and CeIrAl4sub>Si2 were determined to be 1.14(2) and 1.41(3) μB/Ce, respectively, and are parallel to the crystallographic c-axis in agreement with magnetic susceptibility measurements.

  8. eIF3f reduces tumor growth by directly interrupting clusterin with anti-apoptotic property in cancer cells

    PubMed Central

    Lee, Ji-Yeon; Kim, Hyun-Ji; Rho, Seung Bae; Lee, Seung-Hoon

    2016-01-01

    Clusterin is a secretory heterodimeric glycoprotein and the overexpression of secretory clusterin (sCLU) promotes cancer cell proliferation and reduces chemosensitivity. Therefore, sCLU might be an effective target for anticancer therapy. In the current study, we identified eIF3f as a novel CLU-interacting protein and demonstrated its novel function as a CLU inhibitor. The overexpression of eIF3f retarded cancer cell growth significantly and induced apoptosis. In addition, eIF3f interacted with the α-chain (1–227) of sCLU. This interaction blocked modification of psCLU, thereby decreasing the expression and secretion of α/β CLU. Consequently, the overexpression of eIF3f suppressed Akt and ERK signaling and subsequently depleted CLU expression. In addition, eIF3F stabilized p53, which increased the expression of p21 and Bax. Interestingly, the expression of Bax was increased without the activation of p53. eIF3f injected into a xenograft model of human cervical cancer in nude mice markedly inhibited tumor growth. The identification of this novel function of eIF3f as a sCLU inhibitor might open novel avenues for developing improved strategies for CLU-targeted anti-cancer therapies. PMID:26988917

  9. Pou3f4-Mediated Regulation of Ephrin-B2 Controls Temporal Bone Development in the Mouse

    PubMed Central

    Raft, Steven; Coate, Thomas M.; Kelley, Matthew W.; Crenshaw, E. Bryan; Wu, Doris K.

    2014-01-01

    The temporal bone encases conductive and sensorineural elements of the ear. Mutations of POU3F4 are associated with unique temporal bone abnormalities and X-linked mixed deafness (DFNX2/DFN3). However, the target genes and developmental processes controlled by POU3F4 transcription factor activity have remained largely uncharacterized. Ephrin-B2 (Efnb2) is a signaling molecule with well-documented effects on cell adhesion, proliferation, and migration. Our analyses of targeted mouse mutants revealed that Efnb2 loss-of-function phenocopies temporal bone abnormalities of Pou3f4 hemizygous null neonates: qualitatively identical malformations of the stapes, styloid process, internal auditory canal, and cochlear capsule were present in both mutants. Using failed/insufficient separation of the stapes and styloid process as a quantitative trait, we found that single gene Efnb2 loss-of-function and compound Pou3f4/Efnb2 loss-of-function caused a more severe phenotype than single gene Pou3f4 loss-of-function. Pou3f4 and Efnb2 gene expression domains overlapped at the site of impending stapes-styloid process separation and at subcapsular mesenchyme surrounding the cochlea; at both these sites, Efnb2 expression was attenuated in Pou3f4 hemizygous null mutants relative to control. Results of immunoprecipitation experiments using chromatin isolated from nascent middle ear mesenchyme supported the hypothesis of a physical association between Pou3f4 and specific non-coding sequence of Efnb2. We propose that Efnb2 is a target of Pou3f4 transcription factor activity and an effector of mesenchymal patterning during temporal bone development. PMID:25299585

  10. Single crystal growth of Yb doped NaGd(WO{sub 4}){sub 2} and structural and spectroscopic studies

    SciTech Connect

    Singh, S. G.; Singh, A. K.; Desai, D. G.; Tiwari, B.; Tyagi, M.

    2014-04-24

    High quality single crystals of NaGd(WO{sub 4}){sub 2} doped with 5 mol % Yb and oriented along <001> have been grown by the Czochralski technique in Ar atmosphere. The tetragonal space group I41/a accounts for all the reflections observed in the powder X-ray diffraction analysis. Polarized optical spectroscopy at room temperature revealed a direction dependence of absorption at different wavelength. As a novel uniaxial laser host for Yb{sup 3+}, NaGd(WO{sub 4}){sub 2} is characterized with respect to its transparency and band-edge. The emission spectrum of Yb{sup 3+} (excitation: 980-990 nm diode laser) was also recorded.

  11. Investigation of room temperature ferromagnetic nanoparticles of Gd5Si4sub>

    SciTech Connect

    Hadimani, R. L.; Gupta, S.; Harstad, S. M.; Pecharsky, V. K.; Jiles, D. C.

    2015-07-06

    Gd5(SixGe1-x)4sub> compounds undergo first-order phase transitions close to room temperature when x ~ = 0.5, which are accompanied by extreme changes of properties. We report the fabrication of the nanoparticles of one of the parent compounds-Gd5Si4sub>-using high-energy ball milling. Crystal structure, microstructure, and magnetic properties have been investigated. Particles agglomerate at long milling times, and the particles that are milled >20 min lose crystallinity and no longer undergo magnetic phase transition close to 340 K, which is present in a bulk material. The samples milled for >20 min exhibit a slightly increased coercivity. As a result, magnetization at a high temperature of 275K decreases with the increase in the milling time.

  12. Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber.

    PubMed

    Amole, C; Ardid, M; Asner, D M; Baxter, D; Behnke, E; Bhattacharjee, P; Borsodi, H; Bou-Cabo, M; Brice, S J; Broemmelsiek, D; Clark, K; Collar, J I; Cooper, P S; Crisler, M; Dahl, C E; Daley, S; Das, M; Debris, F; Dhungana, N; Farine, J; Felis, I; Filgas, R; Fines-Neuschild, M; Girard, F; Giroux, G; Hai, M; Hall, J; Harris, O; Jackson, C M; Jin, M; Krauss, C B; Lafrenière, M; Laurin, M; Lawson, I; Levine, I; Lippincott, W H; Mann, E; Martin, J P; Maurya, D; Mitra, P; Neilson, R; Noble, A J; Plante, A; Podviianiuk, R B; Priya, S; Robinson, A E; Ruschman, M; Scallon, O; Seth, S; Sonnenschein, A; Starinski, N; Štekl, I; Vázquez-Jáuregui, E; Wells, J; Wichoski, U; Zacek, V; Zhang, J

    2015-06-12

    New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of <3.5×10(-10) and an alpha rejection factor of >98.2%. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering. PMID:26196790

  13. Alterations in rabbit vitreal fine structure following C3F8 injection.

    PubMed

    Panessa-Warren, B; Maisel, J M; Warren, J

    1990-01-01

    This study examines the morphological and histochemical changes in the cortical vitreous of 36 rabbit eyes following C3F8 intravitreal gas injection. Eyes were examined by light microscopy (LM) using a modified cryofixation and cryosectioning technique that prevented the loss of soluble tissue moieties and permitted collagen and proteoglycan histochemistry as well as enzyme digestion with hyaluronidase. LM and scanning electron microscopy (SEM) of cryosectioned normal eyes revealed an elaborate fibrillar matrix extending 100-190 microns from the basal lamina of the retina into the vitreous proper, which seemed to be composed of collagen fibrils intimately associated or wrapped in proteoglycan. Following the full expansion of the C3F8 gas bubble in the vitreous, the cortical fibrillar meshwork was absent from the retinal surface and a dense, collagenous material accumulated in the anterior vitreous, especially between the ciliary processes and over the posterior face of the lens. At 41 days postinjection, the fibrillar matrix was reforming and the vitreal cavity was filled with fluid and numerous fibrillar-mucinous islands. These islands did not form sheets or membranes, nor did they attach to either the posterior or the anterior retinal surface. The cortical fibrillar meshwork had reformed at 61 days' recovery; however, the condensed fibrillar material against the lens and filling the spaces between the ciliary processes had not resorbed. Neither shearing of the cortical gel or fibrillar matrix nor congestion of the anterior vitreous was observed in eyes only partially filled with gas. PMID:2265770

  14. Dark Matter Search Results from the PICO-2L C3F8 Bubble Chamber

    NASA Astrophysics Data System (ADS)

    Amole, C.; Ardid, M.; Asner, D. M.; Baxter, D.; Behnke, E.; Bhattacharjee, P.; Borsodi, H.; Bou-Cabo, M.; Brice, S. J.; Broemmelsiek, D.; Clark, K.; Collar, J. I.; Cooper, P. S.; Crisler, M.; Dahl, C. E.; Daley, S.; Das, M.; Debris, F.; Dhungana, N.; Farine, J.; Felis, I.; Filgas, R.; Fines-Neuschild, M.; Girard, F.; Giroux, G.; Hai, M.; Hall, J.; Harris, O.; Jackson, C. M.; Jin, M.; Krauss, C. B.; Lafrenière, M.; Laurin, M.; Lawson, I.; Levine, I.; Lippincott, W. H.; Mann, E.; Martin, J. P.; Maurya, D.; Mitra, P.; Neilson, R.; Noble, A. J.; Plante, A.; Podviianiuk, R. B.; Priya, S.; Robinson, A. E.; Ruschman, M.; Scallon, O.; Seth, S.; Sonnenschein, A.; Starinski, N.; Štekl, I.; Vázquez-Jáuregui, E.; Wells, J.; Wichoski, U.; Zacek, V.; Zhang, J.; PICO Collaboration

    2015-06-01

    New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of <3.5 ×1 0-10 and an alpha rejection factor of >98.2 %. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. These data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.

  15. SU (3)F gauge family model and new symmetry breaking scale from FCNC processes

    NASA Astrophysics Data System (ADS)

    Bao, Shou-Shan; Liu, Zhuo; Wu, Yue-Liang

    2016-03-01

    Based on the SU (3)F gauge family symmetry model which was proposed to explain the observed mass and mixing pattern of neutrinos, we investigate the symmetry breaking, the mixing pattern in quark and lepton sectors, and the contribution of the new gauge bosons to some flavour changing neutral currents (FCNC) processes at low energy. With the current data of the mass differences in the neutral pseudo-scalar P0-Pbar0 systems, we find that the SU (3)F symmetry breaking scale can be as low as 300 TeV and the mass of the lightest gauge boson be about 100 TeV. Other FCNC processes, such as the lepton flavour number violation process μ- →e-e+e- and the semi-leptonic rare decay K → π ν bar ν, contain contributions via the new gauge bosons exchanging. With the constrains obtained from P0-Pbar0 system, we estimate that the contribution of the new physics is around 10-16, far below the current experimental bounds.

  16. Dark matter search results from the PICO-2L C$_3$F$_8$ bubble chamber

    DOE PAGESBeta

    Amole, C.

    2015-06-11

    New data are reported from the operation of a 2 liter C3F8 bubble chamber in the SNOLAB underground laboratory, with a total exposure of 211.5 kg days at four different energy thresholds below 10 keV. These data show that C3F8 provides excellent electron-recoil and alpha rejection capabilities at very low thresholds. The chamber exhibits an electron-recoil sensitivity of < 3.5 × 10–10 and an alpha rejection factor of > 98.2%. These data also include the first observation of a dependence of acoustic signal on alpha energy. Twelve single nuclear recoil event candidates were observed during the run. The candidate eventsmore » exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. Lastly, these data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date, with significant sensitivity at low WIMP masses for spin-independent WIMP-nucleon scattering.« less

  17. Effects of Nickel Doping on the Multiferroic and Magnetic Phases of MnWO 4sub>

    SciTech Connect

    Poudel, N.; Lorenz, B.; Lv, B.; Wang, Y. Q.; Ye, F.; Wang, Jinchen; Fernandez-baca, J. A.; Chu, C. W.

    2015-12-15

    There are various orders in multiferroic materials with a frustrated spiral spin modulation inducing a ferroelectric state are extremely sensitive to small perturbations such as magnetic and electric fields, external pressure, or chemical substitutions. A classical multiferroic, the mineral Hubnerite with chemical formula MnWO4sub>, shows three different magnetic phases at low temperature. The intermediate phase between 7.5K < T < 12.7K is multiferroic and ferroelectricity is induced by an inversion symmetry breaking spiral Mn-spin order and strong spin-lattice interactions. Furthermore, the substitution of Ni2+ (spin 1) for Mn2+ (spin 5/2) in MnWO4sub> and its effects on the magnetic and multiferroic phases are studied. The ferroelectric phase is stabilized for low Ni content (up to 10%). Upon further Ni doping, the polarization in the ferroelectric phase is quickly suppressed while a collinear and commensurate magnetic phase, characteristic of the magnetic structure in NiWO4sub>, appears first at higher temperature, gradually extends to lower temperature, and becomes the ground state above 30% doping. Between 10% and 30%, the multiferroic phase coexists with the collinear commensurate phase. In this concentration region, the spin spiral plane is close to the a-b plane which explains the drop of the ferroelectric polarization. Finally, the phase diagram of Mn1-xNixWO4sub> is derived by a combination of magnetic susceptibility, specific heat, electric polarization, and neutron scattering measurements.

  18. Fermions and gauge bosons in SU(4){sub L}xU(1){sub X} models with little Higgs

    SciTech Connect

    Nam, Soo-hyeon

    2008-11-23

    We discuss the aspects of the little Higgs model with the SU(4){sub L}xU(1){sub X} electroweak gauge group as an alternative solution to the naturalness and fine-tuning issues. We introduce anomaly-free fermion spectra, and present their interactions with the physical gauge bosons. We also discuss some phenomenological implications of these fermions and the extra gauge bosons based on recent experimental results.

  19. Crystal chemistry of M{sup II}M′{sup IV}(PO{sub 4}){sub 2} double monophosphates

    SciTech Connect

    Bregiroux, Damien; Popa, Karin; Wallez, Gilles

    2015-10-15

    M{sup II}M′{sup IV}(PO{sub 4}){sub 2} compounds have been extensively studied for several decades for their potential applications in the field of several domains such as matrices for actinides conditioning, phosphors etc. In this paper, the relationships between composition and crystal structure of these compounds are established. A review of the various processes used for the synthesis of these compounds is also proposed, as well as their most reported properties. M{sup II}M′{sup IV}(PO{sub 4}){sub 2} structures stem from two different archetypes: the cheralite and the yavapaiite structures, with some exceptions that are also described in this article. The ratio of the cations radii appears to be the most relevant parameter. The high ratio between the ionic radii of the divalent and tetravalent cations in yavapaiite derivates results in the ordering of these cations into well-differentiated polyhedra whereas cheralite is the only non-ordered structure encountered for M{sup II}M′{sup IV}(PO{sub 4}){sub 2} compounds. - Graphical abstract: In this paper, the relationships between composition and crystal structure of M{sup II}M′{sup IV}(PO{sub 4}){sub 2} compounds are established. A review of the various processes used for the synthesis of these compounds is also proposed, as well as their most reported properties. - Highlights: • Crystal structure–composition relationships of MIIM′IV(PO4)2 compounds. • Review of the various processes used for the synthesis of these compounds. • Their most reported properties are described and discussed.

  20. High-temperature phase transformation and topochemical nature in ferroelastic (NH{sub 4}){sub 2}SO{sub 4}

    SciTech Connect

    Lee, Kwang-Sei; Oh, In-Hwan; Ko, Jae-Hyeon

    2014-04-01

    The electrical conductivity of ferroelastic ammonium sulfate (NH{sub 4}){sub 2}SO{sub 4} revealed an anomaly at around 130 °C (=403 K, T{sub P}) on heating with large and irreversible thermal hysteresis through thermal cycle. Ferroelastic domain walls and surface morphology of (NH{sub 4}){sub 2}SO{sub 4} were investigated by hot-stage polarizing microscopy. Structural phase transition from an orthorhombic ferroelastic phase to a hexagonal paraelastic phase was not identified at T{sub P} upon heating. On further heating above T{sub P}, microscopic spots appeared and grew on the crystal surface, suggesting that the high-temperature anomaly at T{sub P} was an indication of an onset of thermal decomposition controlled by topochemical factors. The increase of electrical conductivity above T{sub P} was attributed to proton migration. - Graphical abstract: Surface morphology of the (100) face of (NH{sub 4}){sub 2}SO{sub 4} on heating, showing chemical reaction at the surface. - Highlights: • We investigate the high-temperature phase transformation of ammonium sulfate. • The increasing conductivity upon heating is attributed to proton migration. • Structural phase transition from orthorhombic to hexagonal phase is not confirmed. • High-temperature anomaly is related to an onset of thermal decomposition. • The nature of the high-temperature anomaly is topochemical controlled by defects.

  1. Hydrothermal synthesis and luminescent properties of NaLa(MoO{sub 4}){sub 2}:Dy{sup 3+} phosphor

    SciTech Connect

    Li Linlin; Zi Wenwen; Li Guanghuan; Lan Shi; Ji Guijuan; Gan Shucai; Zou Haifeng; Xu Xuechun

    2012-07-15

    Pompon-like NaLa(MoO{sub 4}){sub 2}:Dy{sup 3+} phosphors have been successfully prepared via a hydrothermal method using ammonia as pH value regulator. The hydrothermal process was carried out under aqueous condition without the use of any organic solvent, surfactant, and catalyst. The experimental results demonstrate that the obtained NaLa(MoO{sub 4}){sub 2}:Dy{sup 3+} phosphor powders are single-phase scheelite structure with tetragonal symmetry. Moreover, the phosphor under the excitation of 390 and 456 nm exhibited blue emission (486 nm) and yellow emission (574 nm), corresponding to the {sup 4}F{sub 9/2}{yields}{sup 6}H{sub 15/2} transition and {sup 4}F{sub 9/2}{yields}{sup 6}H{sub 13/2} transition of Dy{sup 3+} ions, respectively. In addition, the yellow-to-blue emission intensity ratio (Y/B) can be changed with the doped concentration of Dy{sup 3+} ions. All chromaticity coordinates of the obtained NaLa(MoO{sub 4}){sub 2}:Dy{sup 3+} phosphors are located in the white-light region. The results indicate that this kind of phosphor may has potential applications in the fields of near UV-excited and blue-excited white LEDs. - Graphical abstract: It can be seen from the SEM images that a pompon-like shape was obtained with an average diameter of about 1 {mu}m, and it is composed of many nanoflakes. Highlights: Black-Right-Pointing-Pointer Pompon-like NaLa(MoO{sub 4}){sub 2}:Dy{sup 3+} phosphors have been successfully prepared via a hydrothermal method. Black-Right-Pointing-Pointer Blue emission at 486 nm and yellow emission at 574 nm were obtained from the samples. Black-Right-Pointing-Pointer The yellow-to-blue emission intensity ratio (Y/B) can be changed with the doped concentration of Dy{sup 3+} ions. Black-Right-Pointing-Pointer NaLa(MoO{sub 4}){sub 2}:Dy{sup 3+} can be efficiently excited by the blue light and the near ultraviolet light.

  2. Characteristics and nature of the halogen-bonding interactions between CCl3F and ozone: a supermolecular and SAPT study

    NASA Astrophysics Data System (ADS)

    Esrafili, Mehdi D.; Yourdkhani, Sirous; Bahrami, Aidin

    2013-12-01

    The strength and nature of the halogen-bond interactions in CCl3F...O3 complexes were examined by means of ab initio quantum-chemical calculations and symmetry-adapted perturbation theory (SAPT). Our calculations predict a trifurcated C-Cl...O interaction for the global minimum of CCl3F...O3 complex and several local minima, differing slightly in energy, separated by very low barriers. The calculations, which include a rigorous decomposition of the interaction energies, also indicate that the interaction of CCl3F molecule with O3 is characterised by contributions from both electrostatic and dispersion energies, with the contribution of the latter being dominant. The evaluated SAPT interaction energies for the CCl3F...O3 complexes are generally in good agreement with those obtained using the supermolecule CCSD(T) method, suggesting that SAPT is a proper method to study the intermolecular interactions in these complexes.

  3. Sequential arrival and graded secretion of Sema3F by olfactory neuron axons specify map topography at the bulb.

    PubMed

    Takeuchi, Haruki; Inokuchi, Kasumi; Aoki, Mari; Suto, Fumikazu; Tsuboi, Akio; Matsuda, Ikuo; Suzuki, Misao; Aiba, Atsu; Serizawa, Shou; Yoshihara, Yoshihiro; Fujisawa, Hajime; Sakano, Hitoshi

    2010-06-11

    In the mouse olfactory system, the anatomical locations of olfactory sensory neurons (OSNs) roughly correlate with their axonal projection sites along the dorsal-ventral (D-V) axis of the olfactory bulb (OB). Here we report that an axon guidance receptor, Neuropilin-2 (Nrp2), and its repulsive ligand, Semaphorin-3F (Sema3F), are expressed by OSNs in a complementary manner that is important for establishing olfactory map topography. Sema3F is secreted by early-arriving axons of OSNs and is deposited at the anterodorsal OB to repel Nrp2-positive axons that arrive later. Sequential arrival of OSN axons as well as the graded and complementary expression of Nrp2 and Sema3F by OSNs help to form the topographic order along the D-V axis. PMID:20550939

  4. 1.1 MW peak power in doubly QML composite Nd:YVO4sub>/Nd:YVO4sub>/Nd:YVO4sub>/KTP sub-nanosecond green laser with EO and Bi-GaAs.

    PubMed

    Li, Shixia; Li, Dechun; Zhao, Shengzhi; Li, Guiqiu; Li, Xiangyang; Qiao, Hui

    2016-02-22

    By simultaneously employing electro-optic (EO) modulator and Bi-doped GaAs, dual-loss-modulated Q-switched and mode-locked (QML) multi-segment composite Nd:YVO4sub>/Nd:YVO4sub>/Nd:YVO4sub>/KTP sub-nanosecond green laser is demonstrated with low repetition rate and high peak power. When the incident pump power is up to 6.93 W, only one mode-locking pulse underneath a Q-switching envelope is generated with sub-nanosecond pulse duration at one kilohertz repetition rate. An average output power of 445 mW and a pulse duration of 399 ps are obtained with the incident pump power of 11.13 W, corresponding to a peak power of 1.115 MW which is the highest one in doubly QML sub-nanosecond green laser by now. The laser characteristics are better than those obtained with EO and GaAs. The experimental results indicate that Bi-GaAs is a promising saturable absorber for dual-loss-modulated QML laser. PMID:26907054

  5. The Rice Eukaryotic Translation Initiation Factor 3 Subunit f (OseIF3f) Is Involved in Microgametogenesis

    PubMed Central

    Li, Qi; Deng, Zhuyun; Gong, Chunyan; Wang, Tai

    2016-01-01

    Microgametogenesis is the post-meiotic pollen developmental phase when unicellular microspores develop into mature tricellular pollen. In rice, microgametogenesis can influence grain yields to a great degree because pollen abortion occurs more easily during microgametogenesis than during other stages of pollen development. However, our knowledge of the genes involved in microgametogenesis in rice remains limited. Due to the dependence of pollen development on the regulatory mechanisms of protein expression, we identified the encoding gene of the eukaryotic translation initiation factor 3, subunit f in Oryza sativa (OseIF3f). Immunoprecipitation combined with mass spectrometry confirmed that OseIF3f was a subunit of rice eIF3, which consisted of at least 12 subunits including eIF3a, eIF3b, eIF3c, eIF3d, eIF3e, eIF3f, eIF3g, eIF3h, eIF3i, eIF3k, eIF3l, and eIF3m. OseIF3f showed high mRNA levels in immature florets and is highly abundant in developing anthers. Subcellular localization analysis showed that OseIF3f was localized to the cytosol and the endoplasmic reticulum in rice root cells. We further analyzed the biological function of OseIF3f using the double-stranded RNA-mediated interference (RNAi) approach. The OseIF3f-RNAi lines grew normally at the vegetative stage but displayed a large reduction in seed production and pollen viability, which is associated with the down-regulation of OseIF3f. Further cytological observations of pollen development revealed that the OseIF3f-RNAi lines showed no obvious abnormalities at the male meiotic stage and the unicellular microspore stage. However, compared to the wild-type, OseIF3f-RNAi lines contained a higher percentage of arrested unicellular pollen at the bicellular stage and a higher percentage of arrested unicellular and bicellular pollen, and aborted pollen at the tricellular stage. These results indicate that OseIF3f plays a role in microgametogenesis. PMID:27200010

  6. Luminescence properties of Yb:Er:KY3F10 nanophosphor and thermal treatment effects

    NASA Astrophysics Data System (ADS)

    Gomes, Laércio; Linhares, Horácio Marconi da Silva M. D.; Ichikawa, Rodrigo Uchida; Martinez, Luis Gallego; Baldochi, Sonia Licia

    2016-04-01

    In this work, we present the spectroscopic properties of KY3F10 nanocrystals activated with erbium and codoped with ytterbium ions. The most important processes that lead to the erbium upconversion of green and red emissions of Er3+ were identified. A time-resolved luminescence spectroscopy technique was employed to measure the luminescence decays of 4S3/2 and 4F9/2 excited levels of Er3+ and to determine the upconversion processes and the luminescence efficiencies of erbium in the visible. Analysis of the luminescence kinetics in Yb:Er:KY3F10 shows a rapid upconversion (Up1) for the green emission with a time constant of 0.31 μs after pulsed laser excitation at 972 nm for as synthesized nanocrystals, which is faster than the time constant measured for the bulk crystal (23 μs). In addition, it is observed a second upconversion process (non-resonant) (Up2) responsible for the red emission (Er3+), which competes with Up1 process. However, the luminescence efficiency of the green emission (4S3/2) is observed to be very low (1.6%) for the as synthesized nanocrystal (25 °C). Nevertheless, it increases with the nanopowder heat treatment reaching an efficiency of 99% (T = 550 °C) relative to the bulk crystal. Similar luminescence behavior was observed for the 4F9/2 level (Er3+) that emits red emission. X-ray diffraction analysis of nanopowder by Rietveld method reveled that the mean crystallite size remains unchanged (8.3-12.3 nm) after thermal treatments with T ∼ 400 °C, while the 4S3/2 luminescence efficiency strongly increases to 20%. The luminescence dynamics indicates that Er3+ ions distribution plays a determinant role in the luminescence efficiency of green and red emissions of Er3+ besides also the strong influence on the upconversions processes. The observed luminescence effect is caused by the non-uniform Er3+ (and Yb3+) ions distribution due to the nanocrystal grown, which introduces a concentration gradient that increases towards the nanoparticle

  7. NbRABG3f, a member of Rab GTPase, is involved in Bamboo mosaic virus infection in Nicotiana benthamiana.

    PubMed

    Huang, Ying-Ping; Jhuo, Jia-Hua; Tsai, Meng-Shan; Tsai, Ching-Hsiu; Chen, Hong-Chi; Lin, Na-Sheng; Hsu, Yau-Heiu; Cheng, Chi-Ping

    2016-06-01

    The screening of differentially expressed genes in plants after pathogen infection can uncover the potential host factors required for the pathogens. In this study, an up-regulated gene was identified and cloned from Nicotiana benthamiana plants after Bamboo mosaic virus (BaMV) inoculation. The up-regulated gene was identified as a member of the Rab small guanosine triphosphatase (GTPase) family, and was designated as NbRABG3f according to its in silico translated product with high identity to that of RABG3f of tomato. Knocking down the expression of NbRABG3f using a virus-induced gene silencing technique in a protoplast inoculation assay significantly reduced the accumulation of BaMV. A transiently expressed NbRABG3f protein in N. benthamiana plants followed by BaMV inoculation enhanced the accumulation of BaMV to approximately 150%. Mutants that had the catalytic site mutation (NbRABG3f/T22N) or had lost their membrane-targeting capability (NbRABG3f/ΔC3) failed to facilitate the accumulation of BaMV in plants. Because the Rab GTPase is responsible for vesicle trafficking between organelles, a mutant with a fixed guanosine diphosphate form was used to identify the donor compartment. The use of green fluorescent protein (GFP) fusion revealed that GFP-NbRABG3f/T22N clearly co-localized with the Golgi marker. In conclusion, BaMV may use NbRABG3f to form vesicles derived from the Golgi membrane for intracellular trafficking to deliver unidentified factors to its replication site; thus, both GTPase activity and membrane-targeting ability are crucial for BaMV accumulation at the cell level. PMID:26416342

  8. Sema3F downregulates p53 expression leading to axonal growth cone collapse in primary hippocampal neurons

    PubMed Central

    Yang, Guanglu; Qu, Xiang; Zhang, Junmei; Zhao, Weidong; Wang, Hua

    2012-01-01

    Hippocampal nerve growth is regulated by the coordinated action of numerous external stimuli, including positively acting neurotrophin-derived growth cues and restrictive semaphorin cues, however the underlying cellular mechanisms remain largely unclear. We examined the potential cellular mechanism of Semaphorin3F (Sema3F) in cultured primary hippocampal neurons. We show that Sema3F can down-regulate p53 expression in primary hippocampal neurons, thereby contributing to growth cone collapse. Sema3F suppressed p53-induced pathways, which we show to be required to maintain growth cone structure. Sema3F-induced growth cone collapse was partially reversed by overexpression of p53, which promoted growth cone extension. Inhibition of p53 function by inhibitor, siRNAs, induced axonal growth cone collapse, whereas p53 over-expression led to larger growth cones in cultured primary hippocampal neurons.These data reveal a novel mechanism by which Sema3F can induce hippocampal neuron growth cone collapse and provide evidence for an intracellular mechanism for cross talk between positive and negative axon growth cues. PMID:22977659

  9. Nonlinear optical properties ofBaAlBO3F2 crystal.

    PubMed

    Zhou, Yong; Yue, Yinchao; Wang, Jianuo; Yang, Feng; Cheng, Xiankun; Cui, Dafu; Peng, Qinjun; Hu, Zhanggui; Xu, Zuyan

    2009-10-26

    We investigated the nonlinear optical properties of new BaAlBO(3)F(2)(BABF) crystal. The high quality BABF is nonhygroscopic and possesses a moderate birefringence suitable for UV light generation. On the basis of its refractive index dispersion curves, it is inferred that BABF has great potential applications nonlinear optical material, notably for UV light generation at 355 nm. In order to characterize its nonlinear optical properties, BABF samples were cut an oriented in phase matching conditions The optical conversion efficiency from 1064 nm to 532 nm was investigated for the first time: up to 49.0% were achieved. The external angular acceptance bandwidth of SHG and THG for 1064 nm pump light was measured. PMID:19997227

  10. In-band pumped Ho3+:KY3F10 2 μm laser.

    PubMed

    Schellhorn, Martin; Parisi, Daniela; Veronesi, Stefano; Bolognesi, Giacomo; Eichhorn, Marc; Tonelli, Mauro

    2013-02-15

    We report the first observation to our knowledge of room-temperature continuous-wave laser operation on the (5)I(7)→(5)I(8) transition of Ho(3+) ions in a KY(3)F(10) single crystal. Using a Tm-doped silica fiber laser operating at 1938 nm as a pump source, a maximum laser power of 1.8 W was obtained at a wavelength of ~2040 nm for 27 W of absorbed pump power with a slope efficiency of 19.1% with respect to absorbed power. At low cavity output coupling, the lasing wavelength shifted to 2060.5 nm. The beam propagation factor (M(2)) was measured to be <1.06 at the maximum output power, confirming fundamental transverse-mode (TEM(00)) operation. Performing a Caird analysis, we determined resonator round-trip losses and intrinsic slope efficiency of 30% and 43.8%, respectively. PMID:23455117

  11. Ne matrix spectra of the sym-C6Br3F3+ radical cation

    USGS Publications Warehouse

    Bondybey, V.E.; Sears, T.J.; Miller, T.A.; Vaughn, C.; English, J.H.; Shiley, R.S.

    1981-01-01

    The electronic absorption and laser excited, wavelength resolved fluorescence spectra of the title cation have been observed in solid Ne matrix and vibrationally analysed. The vibrational structure of the excited B2A2??? state shows close similarity to the parent compound. The X2E??? ground state structure is strongly perturbed and irregular owing to a large Jahn-Teller distortion. The data are analysed in terms of a recently developed, sophisticated multimode Jahn-Teller theoretical model. We have generated the sym-C6Br3F3+ cations in solid Ne matrix and obtained their wavelength resolved emission and absorption spectra. T ground electronic X2E??? state exhibits an irregular and strongly perturbed vibrational structure, which can be successfully modeled using sophisticated multimode Jahn-Teller theory. ?? 1981.

  12. Vibrational relaxation of matrix-isolated CH/sub 3/F and HCl

    SciTech Connect

    Young, L.

    1981-08-01

    Kinetic and spectroscopic studies have been performed on CH/sub 3/F and HCl as a function of host matrix and temperature. Temporally and spectrally resolved infrared fluorescence was used to monitor the populations of both the initially excited state and the lower lying levels which participate in the relaxation process. For CH/sub 3/F, relaxation from any of the levels near 3.5 ..mu.., i.e. the CH stretching fundamentals or bend overtones, occurs via rapid (< 5 ns) V ..-->.. V transfer to 2..nu../sub 3/ with subsequent relaxation of the ..nu../sub 3/ (CF stretch) manifold. Lifetimes of 2..nu../sub 3/ and ..nu../sub 3/ were determined through overtone, ..delta..V = 2, and fundamental fluorescence. These lifetimes show a dramatic dependence on host lattice, an increase of two orders of magnitude in going from Xe and Ar matrices. Lifetimes depend only weakly on temperature. The relaxation of 2..nu../sub 3/ and ..nu../sub 3/ is consistent with a model in which production of a highly rotationally excited guest via collisions with the repulsive wall of the host is the rate limiting step. For HCl, lifetimes of v = 1,2,3 have been determined. In all hosts, the relaxation is non-radiative. For a given vibrational state, v, the relaxation rate increases in the series k(Ar) < k(Kr) < k(Xe). The dependence of the relaxation rate; on v is superlinear in all matrices, the deviation from linearity increasng in the order Ar < Kr < Xe. The relaxation rates become more strongly temperature dependent with increasing vibrational excitation. The results are consistent with a mechanism in which complex formation introduces the anisotropy necessary to induce a near resonant V ..-->.. R transition in the rate limiting step.

  13. New open-framework in the uranyl vanadates A{sub 3}(UO{sub 2}){sub 7}(VO{sub 4}){sub 5}O (A=Li, Ag) with intergrowth structure between A(UO{sub 2}){sub 4}(VO{sub 4}){sub 3} and A{sub 2}(UO{sub 2}){sub 3}(VO{sub 4}){sub 2}O

    SciTech Connect

    Obbade, S. Renard, C.; Abraham, F.

    2009-03-15

    New uranyl vanadates A{sub 3}(UO{sub 2}){sub 7}(VO{sub 4}){sub 5}O (M=Li (1), Na (2), Ag (3)) have been synthesized by solid-state reaction and their structures determined from single-crystal X-ray diffraction data for 1 and 3. The tetragonal structure results of an alternation of two types of sheets denoted S for {sub {infinity}}{sup 2}[UO{sub 2}(VO{sub 4}){sub 2}]{sup 4-} and D for {sub {infinity}}{sup 2}[(UO{sub 2}){sub 2}(VO{sub 4}){sub 3}]{sup 5-} built from UO{sub 6} square bipyramids and connected through VO{sub 4} tetrahedra to {sub {infinity}}{sup 1}[U(3)O{sub 5}-U(4)O{sub 5}]{sup 8-} infinite chains of edge-shared U(3)O{sub 7} and U(4)O{sub 7} pentagonal bipyramids alternatively parallel to a- and b-axis to construct a three-dimensional uranyl vanadate arrangement. It is noticeable that similar {sub {infinity}}[UO{sub 5}]{sup 4-} chains are connected only by S-type sheets in A{sub 2}(UO{sub 2}){sub 3}(VO{sub 4}){sub 2}O and by D-type sheets in A(UO{sub 2}){sub 4}(VO{sub 4}){sub 3}, thus A{sub 3}(UO{sub 2}){sub 7}(VO{sub 4}){sub 5}O appears as an intergrowth structure between the two previously reported series. The mobility of the monovalent ion in the mutually perpendicular channels created in the three-dimensional arrangement is correlated to the occupation rate of the sites and by the geometry of the different sites occupied by either Na, Ag or Li. Crystallographic data: 293 K, Bruker X8-APEX2 X-ray diffractometer equipped with a 4 K CCD detector, MoK{alpha}, {lambda}=0.71073 A, tetragonal symmetry, space group P4-bar m2, Z=1, full-matrix least-squares refinement on the basis of F{sup 2}; 1,a=7.2794(9) A, c=14.514(4) A, R1=0.021 and wR2=0.048 for 62 parameters with 782 independent reflections with I{>=}2{sigma}(I); 3, a=7.2373(3) A, c=14.7973(15) A, R1=0.041 and wR2=0.085 for 60 parameters with 1066 independent reflections with I{>=}2{sigma}(I). - Abstract: A view of the three-dimensional structure of Li{sub 3}(UO{sub 2}){sub 7}(VO{sub 4}){sub 5}O

  14. Supramolecular Chemistry with Uranyl Tetrahalide ([UO2X4sub>]2-) Anions

    SciTech Connect

    Deifel, Nicholas P.; Cahill, Christopher L.

    2010-06-01

    Five compounds containing the uranyl tetrabromide anion ([UO2Br4sub>2-) have been synthesized through room temperature reactions of uranium (VI) oxyacetate with several pyridinium cations in highly acidic solutions containing Br- anions. The resulting compounds have been characterized via single-crystal X-ray diffraction and fluorescence spectroscopy. Three of these compounds exhibit both a bifurcated hydrogen bond NH-Br2U and an extended “ribbon motif” of alternating organic and inorganic species.

  15. Synthesis and photoluminescence characteristics of Dy{sup 3+} doped NaY(WO{sub 4}){sub 2} phosphors

    SciTech Connect

    Liu, Xiaohua; Xiang, Wendou; Chen, Fengming; Hu, Zhengfa; Zhang, Wei

    2013-02-15

    Graphical abstract: The phosphor powders of NaY(WO{sub 4}){sub 2}: Dy{sup 3+} were prepared by solid state reaction. For the different kinds of excitations, the dependence of luminescence intensity on the Tb{sup 3+} concentration was investigated. Display Omitted Highlights: ► We synthesize NaY(WO{sub 4}){sub 2}:Dy{sup 3+} phosphors by the solid-state reaction technique. ► We observe and explain the change of Y/B ratio with Dy{sup 3+} content. ► The I−x curve shows different behavior for different excitations. ► The concentration quenching mechanism is the d–d interaction. -- Abstract: The novel phosphor powders of NaY(WO{sub 4}){sub 2} doped with Dy{sup 3+} were synthesized by solid state reaction. X-ray diffraction analysis showed that the phosphors sintered at 900 °C for 6 h were a pure NaY(WO{sub 4}){sub 2} phase for all the Dy{sup 3+} doping concentrations. The room temperature excitation spectra of the phosphors vary with the Dy{sup 3+} concentration and consist of an intense charge transfer band of WO{sub 4}{sup 2−} groups and weak f–f transition absorption peaks of Dy{sup 3+}. The photoluminescence spectra, excited at the peak wavelength of charge transfer band, exhibit three bands centered at 488, 575 and 662 nm, which originate from the transitions of {sup 4}F{sub 9/2} → {sup 6}H{sub 15/2} (blue), {sup 4}F{sub 9/2} → {sup 6}H{sub 13/2} (yellow) and {sup 4}F{sub 9/2} → {sup 6}H{sub 11/2} (red) of Dy{sup 3+}, respectively. The effects of Dy{sup 3+} concentration on luminescence intensity and the yellow-to-blue intensity ratio of the phosphors were investigated. The different behaviors for the doping concentration dependence of luminescence intensity resulted from the different kinds of excitation was discussed.

  16. trans-K3[TcO2(CN)4sub>

    SciTech Connect

    Chatterjee, Sayandev; Del Negro, Andrew S; Edwards, Matthew K; Twamley, Brendan; Krause, Jeanette A; Bryan, Samuel A

    2010-07-14

    The dioxotetracyanotechnetate anion, [TcO2(CN)4sub>]3-, of the title complex has octahedral symmetry. The technetium is located on a center of inversion and is bound by two oxygen atoms and four cyano ligands. The Tc=O bond distance of 1.7721 (12) Å is consistent with double bond character. The potassium cations [located on special (1/2,0,1) and general positions] reside in octahedral or tetrahedral environments; interionic K···O and K···N interactions occur in the 2.7877 (19)-2.8598 (15) Å range.

  17. Infrared-to-visible upconversion in thin films of LaEr(MoO{sub 4}){sub 3}

    SciTech Connect

    Bubb, D.M.; Cohen, D.; Qadri, S.B.

    2005-09-26

    LaEr(MoO{sub 4}){sub 3} thin films have been grown by pulsed laser deposition. The films were characterized by x-ray diffraction, Rutherford backscattering, and fluorescence measurements. The results show that the deposited films were epitaxial with their c axis oriented along the surface normal. Films illuminated with 980 nm laser light show visible emission spectra. This visible emission arises as a result of the Er 4f-4f transitions and their lifetimes. Such so-called 'upconverting phosphors' are important to the development of new chemical and biological sensing applications.

  18. Morphology control of open-framework zinc phosphate Zn{sub 4}(H{sub 3}O)(NH{sub 4}){sub 3}(PO{sub 4}){sub 4} via microwave-assisted technique

    SciTech Connect

    Ding, Ling; Song, Yu; Yang, Wei; Xue, Run-Miao; Zhai, Shang-Ru; An, Qing-Da

    2013-08-15

    Open-framework zinc phosphates were synthesized by microwave-assisted technique, and it was shown that the morphology of as-prepared materials could be easily tailored by changing synthesis temperature, reaction time and pH value. During the synthesis, when the reaction temperature increases from 130 °C to 220 °C, the products transformed from hexagonal prisms to polyhedron along with the disappearance of the hexagonal prisms vertical plane. Simultaneously, both the reaction time and pH value could promote the nucleation and growth of crystal particles. More interestingly, the target products with different morphologies could be obtained by varying the usage of NaOH or NH{sub 3}·H{sub 2}O at 130 °C during the microwave synthesis process. - Graphical abstract: Zinc phosphates with variable morphologies can be obtained by simply tuning the microwave-heating temperatures. Display Omitted - Highlights: • Synthesis of open-framework Zn{sub 4} (H{sub 3}O) (NH{sub 4}){sub 3}(PO{sub 4}){sub 4} compounds employing microwave technique. • Dependence of morphology on the reaction conditions. • Morphology transformation from hexagonal prisms to polyhedron was observed.

  19. Tailoring the surface properties of LiNi0.4sub>Mn0.4sub>Co0.2O₂ by titanium substitution for improved high voltage cycling performance

    SciTech Connect

    Wolff-Goodrich, Silas; Xin, Huolin L.; Lin, Feng; Markus, Isaac M.; Nordlund, Dennis; Asta, Mark; Doeff, Marca M.

    2015-07-30

    The present research aims to provide insights into the behavior of LiNi0.4Mn0.4Co0.2O2 (NMC442) and LiNi0.4sub>Mn0.4sub>Co0.2O₂ (NMC442-Ti02) cathode materials under galvanostatic cycling to high potentials, in the context of previous work which predicted that Ti-substituted variants should deliver higher capacities and exhibit better cycling stability than the unsubstituted compounds. It is found that NMC cathodes containing Ti show equivalent capacity fading but greater specific capacity than those without Ti in the same potential range. When repeatedly charged to the same degree of delithiation, NMC cathodes containing Ti showed better capacity retention. Soft x-ray absorption spectroscopy (XAS) spectra for Mn and Co indicated increased reduction in these elements for NMC cathodes without Ti, indicating that the substitution of Ti for Co acts to suppress the formation of a high impedance rock salt phase at the surface of NMC cathode particles. The results of this study validate the adoption of a facile change to existing NMC chemistries to improve cathode capacity retention under high voltage cycling conditions.

  20. Heterogeneous Nature of Relaxation Dynamics of Room-Temperature Ionic Liquids (EMIm)2[Co(NCS)4sub>] and (BMIm)2[Co(NCS)4sub>

    SciTech Connect

    Hensel-Bielowka, Stella; Wojnarowska, Zaneta; Dzida, Marzena; Zorębski, Edward; Zorębski, Michał; Geppert-Rybczyńska, Monika; Peppel, Tim; Grzybowska, Katarzyna; Wang, Yangyang; Sokolov, Alexei P.; Paluch, Marian

    2015-08-11

    Dynamic crossover above Tg has been recognized as a characteristic feature of molecular dynamics of liquids approaching glass transition. Experimentally, it is manifested as a change in Vogel–Fulcher–Tammann dependence or a breakdown of the Stokes–Einstein and related relations. In this study, we report the exception from this rather general pattern of behavior. By means of dielectric, ultrasonic, rheological, and calorimetric methods, dynamics of two good ionic conductors (BMIm)2[Co(NCS)4sub>] and (EMIm)2[Co(NCS)4sub>] of less common stoichiometry (2:1) was studied in a very broad temperature range. However, none of the mentioned dynamic changes was observed in the entire studied temperature range. On the contrary, the single VFT and the same fractional Walden coefficient were found for conductivity and viscosity changes over 12 decades. Finally and moreover, ultrasonic studies revealed that the data at temperatures which cover the normal liquid region cannot be fitted by a single exponential decay, and the Cole–Cole function should be used instead.

  1. Study of calcium-containing orthophosphates of NaZr{sub 2}(PO{sub 4}){sub 3} structural type by high-temperature X-ray diffraction

    SciTech Connect

    Orlova, A. I.; Kanunov, A. E.; Samoilov, S. G.; Kazakova, A. Yu.; Kazantsev, G. N.

    2013-03-15

    Orthophosphates Ca{sub 0.5}Ti{sub 2}(PO{sub 4}){sub 3}, Ca{sub 0.5}Zr{sub 2}(PO{sub 4}){sub 3}, Ca{sub 0.75}Zr{sub 2}(SiO{sub 4}){sub 0.5}(PO{sub 4}){sub 2.5}, and CaMg{sub 0.5}Zr{sub 1.5}(PO{sub 4}){sub 3} (structural type NaZr{sub 2}(PO{sub 4}){sub 3}), having different occupancies of interframework positions by calcium, have been prepared by the sol-gel method with the subsequent thermal treatment of dried gels and investigated by IR spectroscopy and X-ray diffraction. The analytical indexing of X-ray diffraction patterns is performed within the sp. gr. R3{sup -}. High-temperature X-ray diffraction was used to investigate the behavior of the orthophosphates upon heating: thermal expansion in the temperature range of 20-610 Degree-Sign C (up to 500 Degree-Sign C for Ca{sub 0.5}Zr{sub 2}(PO{sub 4}){sub 3}). The coefficients of thermal expansion are calculated from the shift of diffraction peaks. The unit-cell parameters of crystals at different temperatures are determined. The dependences of thermal expansion and its anisotropy on the occupancy of cation M positions by calcium are revealed.

  2. M{sup II}Ge(PO{sub 4}){sub 2} (M=Ca, Sr, Ba): Crystal structure, phase transitions and thermal expansion

    SciTech Connect

    Popa, Karin; Wallez, Gilles; Bregiroux, Damien; Loiseau, Pascal

    2011-10-15

    Three earth alkali-germanium monophosphates M{sup II}Ge(PO{sub 4}){sub 2} (M=Ca, Sr, Ba) were prepared by solid state reaction and their structures, previously unknown, studied by Rietveld analysis. BaGe(PO{sub 4}){sub 2} and high-temperature {beta}-SrGe(PO{sub 4}){sub 2} (space group C2/m, Z=2) are fully isotypic with yavapaiite, whereas CaGe(PO{sub 4}){sub 2} and low-temperature {alpha}-SrGe(PO{sub 4}){sub 2} (C2/c, Z=4) are distorted derivatives. The phase transition between the two forms is observed for the first time. The thermal expansion, resulting from several structural mechanisms, is very anisotropic. - Graphical abstract: The superstructure of SrGe(PO{sub 4}){sub 2} at room temperature ({alpha}) results from the off-centering of cation Sr{sup II}. Highlights: > Crystal structures of yavapaiite-type M{sup II}Ge(PO{sub 4}){sub 2} (M=Ca, Sr, Ba) have been solved. > Distortion and superstructure result from Ca and Sr off-centering. > A global scheme for the polymorphism of yavapaiites is proposed.

  3. Acrylonitrile is a multisite carcinogen in male and female B6C3F1 mice.

    PubMed

    Ghanayem, Burhan I; Nyska, Abraham; Haseman, Joseph K; Bucher, John R

    2002-07-01

    Acrylonitrile is a heavily produced unsaturated nitrile, which is used in the production of synthetic fibers, plastics, resins, and rubber. Acrylonitrile is a multisite carcinogen in rats after exposure via gavage, drinking water, or inhalation. No carcinogenicity studies of acrylonitrile in a second animal species were available. The current studies were designed to assess the carcinogenicity of acrylonitrile in B6C3F1 mice of both sexes. Acrylonitrile was administered by gavage at 0, 2.5, 10, or 20 mg/kg/day, 5 days per week, for 2 years. Urinary thiocyanate and N-acetyl-S-(2-cyanoethyl)-L-cysteine were measured as markers of exposure to acrylonitrile. In general, there were dose-related increases in urinary thiocyanate and N-acetyl-S-(2-cyanoethyl)-L-cysteine concentrations in all dosed groups of mice and at all time points. Survival was significantly (p < 0.001) reduced in the top dose (20 mg/kg) group of male and female mice relative to controls. The incidence of forestomach papillomas and carcinomas was increased in mice of both sexes in association with an increase in forestomach epithelial hyperplasia. The incidence of Harderian gland adenomas and carcinomas was also markedly increased in the acrylonitrile-dosed groups. In female mice, the incidence of benign or malignant granulosa cell tumors (combined) in the ovary in the 10 mg/kg dose group was greater than that in the vehicle control group, but because of a lack of dose response, this was considered an equivocal finding. In addition, the incidences of atrophy and cysts in the ovary of the 10 and 20 mg/kg dose groups were significantly increased. The incidences of alveolar/bronchiolar adenoma or carcinoma (combined) were significantly increased in female mice treated with acrylonitrile at 10 mg/kg/day for 2 years. This was also considered an equivocal result. In conclusion, these studies demonstrated that acrylonitrile causes multiple carcinogenic effects after gavage administration to male and female B6

  4. Inhalation pharmacokinetics of ethylbenzene in B6C3F1 mice

    SciTech Connect

    Charest-Tardif, G.; Tardif, R.; Krishnan, K. . E-mail: Kannan.krishnan@umontreal.ca

    2006-01-15

    The objective of the present study was to characterize the inhalation pharmacokinetics of ethylbenzene (EB) in male and female B6C3F1 mice following single and repeated exposures. Initially, groups of 28 male and female mice were exposed for 4 h to 75, 200, 500, or 1000 ppm in order to determine potential non-linearity in the kinetics of EB. Then, groups of male and female mice were exposed for 6 h to 75 ppm and 750 ppm (corresponding to the NTP exposures) for 1 or 7 consecutive days, to evaluate whether EB kinetics was altered during repeated exposures, The maximal blood concentration (C {sub max}; mean {+-} SD, n = 4) observed in female mice at the end of a 4-h exposure to 75, 200, 500, and 1000 ppm was 0.53 {+-} 0.18, 2.26 {+-} 0.38, 19.17 {+-} 2.74, and 82.36 {+-} 16.66 mg/L, respectively. The areas under the concentration vs. time curve (AUCs) following 4-h exposure to 75, 200, 500, and 1000 ppm were 88.5, 414.0, 3612.2, and 19,104.1 mg/L/min, respectively, in female mice, and 116.7, 425.7, 3148.3, and 16,039.1 mg/L/min in male mice. The comparison of C {sub max} and the kinetic profile of EB in mice exposed to 75 ppm suggests that they are similar between 1-day and 7-day exposures. However, at 750 ppm, the rate of EB elimination would appear to be greater after repeated exposures than single exposure, the pattern being evident in both male and female mice. Overall, the single and repeated exposure pharmacokinetic data collected in the present study suggest that EB kinetics is saturable at exposure concentrations exceeding 500 ppm (and therefore at 750 ppm used in the NTP mouse cancer bioassay) but is in the linear range at the lower concentration used in the bioassay (75 ppm). These data suggest that consideration of the nature and magnitude of non-linear kinetics and induction of metabolism during repeated exposures is essential for the conduct of a scientifically sound analysis of EB cancer dose-response data collected in B6C3F1 mice.

  5. Down-regulation of semaphorin 3F in rat retinal ganglion cells in response to optic nerve crush.

    PubMed

    Ko, Ji-Ae; Minamoto, Akira; Sugimoto, Yosuke; Kiuchi, Yoshiaki

    2016-07-01

    Glaucoma is characterized by degeneration of optic nerve axons and death of retinal ganglion cells (RGCs). Nerve crush and axotomy of the optic nerve are studied as models of RGC death in glaucoma and of axon regeneration. The mechanisms underlying the response of RGCs to axonal injury remain unclear, however. We have now examined the effects of optic nerve crush on the expression of members of the semaphorin family of neuronal guidance proteins in the rat retina. The expression of semaphorin 3F (Sema3F) in the retina was down-regulated at both the mRNA and protein levels at 7 days after optic nerve injury, whereas that of Sema3A, Sema3B or Sema3C remained unaffected. Immunohistofluorescence analysis and laser capture microdissection followed by reverse transcription-polymerase chain reaction analysis revealed that this loss of Sema3F expression occurred in the RGC layer of the retina. Furthermore, antibody-mediated neutralization of secreted Sema3F in retinal organ culture resulted in down-regulation of neuron-specific βIII-tubulin (Tuj-1 antigen), a marker of RGCs. Our results suggest that Sema3F may contribute to the regulation of RGC function or survival and therefore warrants further investigation as a potential mediator of neuroprotection. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27309587

  6. Cytoplasmic mislocalization of POU3F4 due to novel mutations leads to deafness in humans and mice.

    PubMed

    Parzefall, Thomas; Shivatzki, Shaked; Lenz, Danielle R; Rathkolb, Birgit; Ushakov, Kathy; Karfunkel, Daphne; Shapira, Yisgav; Wolf, Michael; Mohr, Manuela; Wolf, Eckhard; Sabrautzki, Sibylle; de Angelis, Martin Hrabé; Frydman, Moshe; Brownstein, Zippora; Avraham, Karen B

    2013-08-01

    POU3F4 is a POU domain transcription factor that is required for hearing. In the ear, POU3F4 is essential for mesenchymal remodeling of the bony labyrinth and is the causative gene for DFNX2 human nonsyndromic deafness. Ear abnormalities underlie this form of deafness, characterized previously in multiple spontaneous, radiation-induced and transgenic mouse mutants. Here, we report three novel mutations in the POU3F4 gene that result in profound hearing loss in both humans and mice. A p.Gln79* mutation was identified in a child from an Israeli family, revealed by massively parallel sequencing (MPS). This strategy demonstrates the strength of MPS for diagnosis with only one affected individual. A second mutation, p.Ile285Argfs*43, was identified by Sanger sequencing. A p.Cys300* mutation was found in an ENU-induced mutant mouse, schwindel (sdl), by positional cloning. The mutation leads to a predicted truncated protein, similar to the human mutations, providing a relevant mouse model. The p.Ile285Argfs*43 and p.Cys300* mutations lead to a shift of Pou3f4 nuclear localization to the cytoplasm, demonstrated in cellular localization studies and in the inner ears of the mutant mice. The discovery of these mutations facilitates a deeper comprehension of the molecular basis of inner ear defects due to mutations in the POU3F4 transcription factor. PMID:23606368

  7. Nanocrystalline K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}: Eu for proton beam dosimetry

    SciTech Connect

    Bahl, Shaila; Lochab, S. P.; Pandey, A.; Aleynikov, V. E.; Molokanov, A.; Kumar, Pratik

    2012-06-05

    This paper investigates the Thermoluminescent response of nanocrystalline K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}: Eu, prepared by Co-precipitation technique to 150 MeV proton beam. The particle size was calculated to be 45 nm by the broadening of the XRD peaks using Scherrer's formula. Samples in the form of pellets were irradiated by 150 MeV proton beam with dose range of 0.1 Gy to 325 Gy. Thermoluminescence (TL) glow curves of the irradiated samples were recorded and studied. It has been found that the phosphor shows a characteristic single peak at around 420 K. The TL response is linear in the range upto 200 Gy and then saturates for higher doses. The wider linear TL response of nanocrystalline K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}: Eu and low fading makes it a superior candidate as a dosimeter to be used for detecting the doses of protons beams for its various applications in the field of space, therapy and research.

  8. First-principles predicted low-energy structures of NaSc(BH{sub 4}){sub 4}

    SciTech Connect

    Tran, Huan Doan Amsler, Maximilian; Goedecker, Stefan; Botti, Silvana; Marques, Miguel A. L.

    2014-03-28

    According to previous interpretations of experimental data, sodium-scandium double-cation borohydride NaSc(BH{sub 4}){sub 4} crystallizes in the crystallographic space group Cmcm where each sodium (scandium) atom is surrounded by six scandium (sodium) atoms. A careful investigation of this phase based on ab initio calculations indicates that the structure is dynamically unstable and gives rise to an energetically and dynamically more favorable phase with C222{sub 1} symmetry and nearly identical x-ray diffraction pattern. By additionally performing extensive structural searches with the minima-hopping method we discover a class of new low-energy structures exhibiting a novel structural motif in which each sodium (scandium) atom is surrounded by four scandium (sodium) atoms arranged at the corners of either a rectangle with nearly equal sides or a tetrahedron. These new phases are all predicted to be insulators with band gaps of 7.9–8.2 eV. Finally, we estimate the influence of these structures on the hydrogen-storage performance of NaSc(BH{sub 4}){sub 4}.

  9. Sum Rules of Charm C P Asymmetries beyond the SU(3 ) F Limit

    NASA Astrophysics Data System (ADS)

    Müller, Sarah; Nierste, Ulrich; Schacht, Stefan

    2015-12-01

    We find new sum rules between direct C P asymmetries in D meson decays with coefficients that can be determined from a global fit to branching ratio data. Our sum rules eliminate the penguin topologies P and P A , which cannot be determined from branching ratios. In this way, we can make predictions about direct C P asymmetries in the standard model without ad hoc assumptions on the sizes of penguin diagrams. We consistently include first-order SU(3 ) F breaking in the topological amplitudes extracted from the branching ratios. By confronting our sum rules with future precise data from LHCb and Belle II, one will identify or constrain new-physics contributions to P or P A . The first sum rule correlates the C P asymmetries aCP dir in D0→K+K-, D0→π+π- , and D0→π0π0. We study the region of the aCP dir(D0→π+π-)-aCP dir(D0→π0π0) plane allowed by current data and find that our sum rule excludes more than half of the allowed region at 95% C.L. Our second sum rule correlates the direct C P asymmetries in D+→K¯0K+, Ds+→K0π+, and Ds+→K+π0.

  10. Sum Rules of Charm CP Asymmetries beyond the SU(3)_{F} Limit.

    PubMed

    Müller, Sarah; Nierste, Ulrich; Schacht, Stefan

    2015-12-18

    We find new sum rules between direct CP asymmetries in D meson decays with coefficients that can be determined from a global fit to branching ratio data. Our sum rules eliminate the penguin topologies P and PA, which cannot be determined from branching ratios. In this way, we can make predictions about direct CP asymmetries in the standard model without ad hoc assumptions on the sizes of penguin diagrams. We consistently include first-order SU(3)_{F} breaking in the topological amplitudes extracted from the branching ratios. By confronting our sum rules with future precise data from LHCb and Belle II, one will identify or constrain new-physics contributions to P or PA. The first sum rule correlates the CP asymmetries a_{CP}^{dir} in D^{0}→K^{+}K^{-}, D^{0}→π^{+}π^{-}, and D^{0}→π^{0}π^{0}. We study the region of the a_{CP}^{dir}(D^{0}→π^{+}π^{-})-a_{CP}^{dir}(D^{0}→π^{0}π^{0}) plane allowed by current data and find that our sum rule excludes more than half of the allowed region at 95% C.L. Our second sum rule correlates the direct CP asymmetries in D^{+}→K[over ¯]^{0}K^{+}, D_{s}^{+}→K^{0}π^{+}, and D_{s}^{+}→K^{+}π^{0}. PMID:26722915

  11. Noncollinear magnetization between surface and bulk Y3F e5O12

    NASA Astrophysics Data System (ADS)

    Wu, Po-Hsun; Huang, Ssu-Yen

    2016-07-01

    Yttrium iron garnet (YIG, Y3F e5O12 ) is a magnetic insulator that has been widely used to generate spin-wave spin current via the longitudinal spin Seebeck effect. Spin current can be converted to charge current by the inverse spin Hall effect (ISHE) in an attached metal layer with a spin direction given by the magnetization of the YIG. However, both the ISHE voltage from the thermal transport measurement and the magnetoresistance (MR) from the electrical transport measurement of the metal/YIG structure show a clear plateau behavior in the low-field range, which is inconsistent with the magnetization reversal behavior of the YIG slab. In this work, we provide direct evidences by using the highly sensitive micro-magneto-optic Kerr effect (micro-MOKE) measurement to demonstrate that the plateau behavior in the thermal and electrical transport measurement of metal/YIG is due to the noncollinear magnetization configuration between the bulk and surface of YIG. In addition, keeping the measured surface of YIG unaltered, we show that its surface magnetization can be systematically controlled by varying the thickness. We further demonstrate that the magnetic coupling between the surface magnetization of YIG and an attached ferromagnetic layer exhibits long-range interaction due to the magnetic dipole-dipole interaction.

  12. Alignment of CH3F in para-H2 crystal studied by IR quantum cascade laser polarization spectroscopy.

    PubMed

    Kawasaki, Hiroyuki; Mizoguchi, Asao; Kanamori, Hideto

    2016-05-14

    In order to investigate the alignment of CH3F in para-H2 crystals, high resolution polarization spectroscopy of the ν3 vibrational band is studied using a quantum cascade laser at 1040 cm(-1). It is found that the main and satellite series of peaks in the ν3 vibrational band of CH3F have the same polarization dependence. This result supports the previously proposed cluster model with ortho-H2 in first and second nearest neighbor sites. The observed polarization dependence function is well described by a simple six-axis void model in which CH3F is not aligned along the c-axis of the crystal but tilted to 64.9(3)° from it. PMID:27179483

  13. Alignment of CH3F in para-H2 crystal studied by IR quantum cascade laser polarization spectroscopy

    NASA Astrophysics Data System (ADS)

    Kawasaki, Hiroyuki; Mizoguchi, Asao; Kanamori, Hideto

    2016-05-01

    In order to investigate the alignment of CH3F in para-H2 crystals, high resolution polarization spectroscopy of the ν3 vibrational band is studied using a quantum cascade laser at 1040 cm-1. It is found that the main and satellite series of peaks in the ν3 vibrational band of CH3F have the same polarization dependence. This result supports the previously proposed cluster model with ortho-H2 in first and second nearest neighbor sites. The observed polarization dependence function is well described by a simple six-axis void model in which CH3F is not aligned along the c-axis of the crystal but tilted to 64.9(3)° from it.

  14. Merlin/NF2 Regulates Angiogenesis in Schwannomas through a Rac1/Semaphorin 3F-Dependent Mechanism1

    PubMed Central

    Wong, Hon-Kit; Shimizu, Akio; Kirkpatrick, Nathaniel D; Garkavtsev, Igor; Chan, Annie W; di Tomaso, Emmanuelle; Klagsbrun, Michael; Jain, Rakesh K

    2012-01-01

    Neurofibromatosis type 2 (NF2) is an autosomal-dominant multiple neoplasia syndrome that results from mutations in the NF2 tumor suppressor gene. Patients with NF2 develop hallmark schwannomas that require surgery or radiation, both of which have significant adverse effects. Recent studies have indicated that the tumor microenvironment—in particular, tumor blood vessels—of schwannomas may be an important therapeutic target. Furthermore, although much has been done to understand how merlin, the NF2 gene product, functions as a tumor suppressor gene in schwannoma cells, the functional role of merlin in the tumor microenvironment and the mechanism(s) by which merlin regulates angiogenesis to support schwannoma growth is largely unexplored. Here we report that the expression of semaphorin 3F (SEMA3F) was specifically downregulated in schwannoma cells lacking merlin/NF2. When we reintroduced SEMA3F in schwannoma cells, we observed normalized tumor blood vessels, reduced tumor burden, and extended survival in nude mice bearing merlin-deficient brain tumors. Next, using chemical inhibitors and gene knockdown with RNA interference, we found that merlin regulated expression of SEMA3F through Rho GTPase family member Rac1. This study shows that, in addition to the tumor-suppressing activity of merlin, it also functions to maintain physiological angiogenesis in the nervous system by regulating antiangiogenic factors such as SEMA3F. Restoring the relative balance of proangiogenic and antiangiogenic factors, such as increases in SEMA3F, in schwannoma microenvironment may represent a novel strategy to alleviate the clinical symptoms of NF2-related schwannomas. PMID:22431917

  15. The H2O-CH3F Complex: a Combined Microwave and Infrared Spectroscopic Study Supported by Structure Calculations

    NASA Astrophysics Data System (ADS)

    Gnanasekar, Sharon Priya; Goubet, Manuel; Arunan, Elangannan; Georges, Robert; Soulard, Pascale; Asselin, Pierre; Huet, T. R.; Pirali, Olivier

    2015-06-01

    The H2O-CH3F complex could have two geometries, one with a hydrogen bond and one with the newly proposed carbon bond. While in general carbon bonds are weaker than hydrogen bonds, this complex appears to have comparable energies for the two structures. Infrared (IR) and microwave (MW) spectroscopic measurements using, respectively, the Jet-AILES apparatus and the FTMW spectrometer at the PhLAM laboratory, have been carried out to determine the structure of this complex. The IR spectrum shows the formation of the CH3F- H2O hydrogen bonded complex and small red-shifts in OH frequency most probably due to (CH3F)m-(H2O)n clusters. Noticeably, addition of CH_3F in the mixture promotes the formation of small water clusters. Preliminary MW spectroscopic measurements indicate the formation of the hydrogen bonded complex. So far, we have no experimental evidence for the carbon bonded structure. However, calculations of the Ar-CH3F complex show three energetically equivalent structures: a T-shape, a "fluorine" bond and a carbon bond. The MW spectrum of the (Ar)n-CH3F complexes is currently under analysis. Mani, D; Arunan, E. Phys. Chem. Chem. Phys. 2013, 15, 14377. Cirtog, M; Asselin, P; Soulard, P; Tremblay, B; Madebene, B; Alikhani, M. E; Georges, R; Moudens, A; Goubet, M; Huet, T.R; Pirali, O; Roy, P. J. Phys. Chem. A. 2011, 115, 2523 Kassi, S; Petitprez, D; Wlodarczak, G. J. Mol. Struct. 2000, 517-518, 375

  16. Photoluminescence performance of thulium doped Li{sub 4}SrCa(SiO{sub 4}){sub 2} under irradiation of ultraviolet and vacuum ultraviolet lights

    SciTech Connect

    Wang, Zhaofeng; Li, Yezhou; Liu, Xiong; Wei, Xingmin; Chen, Yueling; Zhou, Fei; Wang, Yuhua

    2014-11-15

    Highlights: • A novel blue-emitting phosphor Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tm{sup 3+} was reported. • Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tm{sup 3+} exhibited excellent thermal and irradiation stability. • Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tm{sup 3+} was found to possess high color purity. - Abstract: In this work, we synthesized Tm{sup 3+} doped Li{sub 4}SrCa(SiO{sub 4}){sub 2} phosphors and investigated their photoluminescence properties under the excitation of ultraviolet and vacuum ultraviolet lights. The crystal structure analysis and variation of cell parameters confirm that Tm{sup 3+} ions have been successfully doped in the structure of Li{sub 4}SrCa(SiO{sub 4}){sub 2} host by occupying the sites of Ca{sup 2+} with the coordination number of 6. The luminescence results suggest that Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tm{sup 3+} is a good blue-emitting phosphor when excited by ultraviolet and vacuum ultraviolet irradiations. In addition, it is observed that there is nearly no degradation for Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tm{sup 3+} after undergoing thermal and irradiation treatments. Possible mechanisms for the luminescence processes are proposed on the basis of the discussion of excitation and emission spectra. In particular, the emission color of Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tm{sup 3+} by excitation of 147 and 172 nm irradiations is very close to the standard blue color, suggesting that it could be potentially applied in plasma display panels and mercury-free fluorescence lamps.

  17. Crystal structure, thermally stability and photoluminescence properties of novel Sr{sub 10}(PO{sub 4}){sub 6}O:Eu{sup 2+} phosphors

    SciTech Connect

    Guo, Qingfeng; Liao, Libing Mei, Lefu; Liu, Haikun

    2015-03-15

    A series of novel luminescent phosphors Sr{sub 10}(PO{sub 4}){sub 6}O:Eu{sup 2+} with apatite structure were synthesized via a high temperature solid-state reaction. The phase structure, photoluminescence (PL) properties, the PL thermal stability, as well as the fluorescence decay curves of the samples were investigated to characterize the resulting samples, and the selected Sr{sub 9.97}(PO{sub 4}){sub 6}O:0.03Eu{sup 2+} phosphor exhibits strong thermal quenching resistance, retaining the luminance of 88.73% at 150 °C. The quenching concentration of Eu{sup 2+} in Sr{sub 10}(PO{sub 4}){sub 6}O was about 0.03 attributing to the dipole–quadrupole interaction. The Sr{sub 10}(PO{sub 4}){sub 6}O:Eu{sup 2+} phosphor exhibited a broad-band blue emission at 439 nm upon excitation at 346 nm. The results indicate that Sr{sub 10}(PO{sub 4}){sub 6}O:Eu{sup 2+} phosphors have potential applications as near UV-convertible phosphors for white-light UV LEDs. - Graphical abstract: Sr{sub 10}(PO{sub 4}){sub 6}O:Eu{sup 2+} phosphors have potential applications as near UV-convertible phosphors for white-light UV LEDs. - Highlights: • Sr{sub 9.97}(PO{sub 4}){sub 6}O:0.03Eu{sup 2+} phosphor exhibits strong thermal quenching resistance. • Two different Eu{sup 2+} emission centers exists in Sr{sub 10}(PO{sub 4}){sub 6}O. • The activation energy was also estimated for the Eu{sup 2+} luminescence center.

  18. Controlled synthesis, characterization and photoluminescence property of olive-like tetragonal α-Nd{sub 2}(MoO{sub 4}){sub 3}

    SciTech Connect

    Zhang, Youjin; Zheng, Ao; Yang, Xiaozhi; He, Hongmei; Fan, Yun

    2012-09-15

    Highlights: ► The olive-like tetragonal α-Nd{sub 2}(MoO{sub 4}){sub 3} was gained with EDTA assisted hydrothermal method. ► The product was characterized by XRD, XPS, FTIR, FESEM, and PL. ► The possible formation mechanism for olive-like α-Nd{sub 2}(MoO{sub 4}){sub 3} was proposed. ► The PL in visible region of the olive-like α-Nd{sub 2}(MoO{sub 4}){sub 3} was studied. -- Abstract: The olive-like tetragonal α-Nd{sub 2}(MoO{sub 4}){sub 3} was obtained by a convenient and facile complex agent assisted hydrothermal method. The product was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FESEM) and photoluminescence (PL). The possible formation mechanism of the olive-like α-Nd{sub 2}(MoO{sub 4}){sub 3} was proposed. The photoluminescence property in visible region of the olive-like tetragonal α-Nd{sub 2}(MoO{sub 4}){sub 3} was studied.

  19. Investigation of the physical properties of the tetragonal CeMAl4sub>Si2 (M = Rh, Ir, Pt) compounds

    SciTech Connect

    Ghimire, N. J.; Ronning, F.; Williams, D. J.; Scott, B. L.; Luo, Yongkang; Thompson, J. D.; Bauer, E. D.

    2014-12-15

    The synthesis, crystal structure and physical properties studied by means of x-ray diffraction, magnetic, thermal and transport measurements of CeMAl4sub>Si2 (M = Rh, Ir, Pt) are reported, along with the electronic structure calculations for LaMAl4sub>Si2 (M = Rh, Ir, Pt). These materials adopt a tetragonal crystal structure (space group P4/mmm) comprised of BaAl4sub> blocks, separated by MAl2 units, stacked along the c-axis. Both CeRhAl4sub>Si2 and CeIrAl4sub>Si2 order antiferromagnetically below TN1 = 14 and 16 K, respectively, and undergo a second antiferromagnetic transitition at lower temperature (TN2 = 9 and 14 K, respectively). CePtAl4sub>Si2 orders ferromagnetically below TC = 3 K with an ordered moment of μsat = 0.8 μB for a magnetic field applied perpendicular to the c-axis. Electronic structure calculations reveal quasi-2D character of the Fermi surface.

  20. Immunotoxicity of nitrobenzene in female B6C3F1 mice.

    PubMed

    Burns, L A; Bradley, S G; White, K L; McCay, J A; Fuchs, B A; Stern, M; Brown, R D; Musgrove, D L; Holsapple, M P; Luster, M I

    1994-01-01

    Nitrobenzene (NBZ) is primarily employed as an oxidizing agent in the synthesis of analine and benzene compounds. It produces myelotoxic effects and effects on erythrocytes in both animal models and man. Reported hepatosplenomegaly and effects on the bone marrow are indicators that NBZ may be immunotoxic. In these studies, female B6C3F1 mice were exposed to 30, 100 and 300 mg/kg of NBZ in corn oil by gavage for 14 consecutive days. To assess the immunotoxic potential of NBZ, body and organ weights were determined and selected immunologic and host resistance responses were studied. In these studies, the liver and spleen appeared to be the primary target organs. Both liver and spleen weights were dose dependently increased. Gross histopathologic examinations revealed significant changes in the spleen, consisting of severe congestion of the red pulp areas with erythrocytes and reticulocytes. Serum chemistry profiles showed increases in alanine aminotransferase and aspartate aminotransferase activities, indicating liver toxicity. Hematologic studies showed a decrease in erythrocyte number and a concomitant increase in mean corpuscular hemoglobin and mean corpuscular volume. A dose-dependent increase in peripheral reticulocytes was also seen. DNA synthesis was enhanced, as was the number of formed elements and the number of monocyte/granulocyte stem cells in the bone marrow of treated mice. IgM responses were decreased and the phagocytic activity of macrophages in the liver was dose dependently increased with a concomitant decrease in the activities in the spleen and lung. Other immunological parameters examined were unchanged. Host resistance to microbial or viral infection was not markedly altered by NBZ; however, there were trends towards increased susceptibility where T-cell function contributes to host defense. These data indicate that NBZ-induced hemolysis and liver injury are linked to the observed alterations in bone marrow activity. PMID:7988385

  1. Chronic bioassays of chlorinated humic acids in B6C3F1 mice

    SciTech Connect

    van Duuren, B.L.; Melchionne, S.; Seidman, I.; Pereira, M.A.

    1986-11-01

    Humic acids (Fluka), chlorinated to carbon:chlorine (C:Cl) ratios of 1:1 and 1:0.3, were administered to B6C3F1 mice, 50 males and 50 females per group, in the drinking water at a total organic carbon (TOC) level of 0.5 g/L. The mice were 6 to 8 weeks old at the beginning of the bioassays. The doses used were based on short-term (8 weeks) evaluations for toxicity, palatability, and weight gain. The chronic bioassays included the following control groups: unchlorinated humic acids (0.5 g/L), no-treatment (100 males and 100 females), dibromoethane (DBE, 2.0 mM in drinking water; positive control) and 0.44% sodium chloride in drinking water, i.e., at the same concentration as those receiving chlorinated humic acids. The chlorinated humic acids were prepared freshly and chemically assayed once per week. All chemicals were, with the exception of DBE, administered for 24 months; DBE was administered for 18 months. The volumes of solutions consumed were measured once weekly. All treatment groups showed normal weight gain except the DBE group. No markedly significant increases in tumor incidences were evident in any of the organs and tissues examined in the chlorinated humic acid groups compared to unchlorinated humic acids and the no-treatment control groups. DBE caused the expected high incidence of squamous carcinomas of the forestomach. The chlorinated humic acids tested contained direct-acting alkylating agents, based on their reactivity with p-nitrobenzylpyridine (PNBP), and showed mutagenic activity in S. typhimurium.

  2. Toxicokinetics of acrylamide and glycidamide in B6C3F{sub 1} mice

    SciTech Connect

    Doerge, Daniel R. . E-mail: ddoerge@nctr.fda.gov; Young, John F.; McDaniel, L. Patrice; Twaddle, Nathan C.; Churchwell, Mona I.

    2005-02-01

    Acrylamide (AA) is a widely studied industrial chemical that is neurotoxic, mutagenic to somatic and germ cells, and carcinogenic in rodents. The recent discovery of AA at ppm levels in a wide variety of commonly consumed foods has energized research efforts worldwide to define toxic mechanisms, particularly toxicokinetics and bioavailability. This study compares the toxicokinetics of AA and its epoxide metabolite glycidamide (GA) in serum and tissues of male and female B6C3F1 mice following acute dosing by intravenous, gavage, and dietary routes at 0.1 mg/kg AA or intravenous and gavage dosing with an equimolar amount of GA. AA was rapidly absorbed from oral dosing, was widely distributed to tissues, was efficiently converted to GA, and increased levels of GA-DNA adducts were observed in liver after complete elimination from serum. GA dosing also resulted in rapid absorption, wide distribution to tissues, and produced liver DNA adduct levels that were approximately 40% higher than those from an equimolar dose of AA. While oral administration was found to attenuate AA bioavailability to 23% from the diet and to 32-52% from aqueous gavage, a first-pass effect or other kinetic change resulted in higher relative internal exposure to GA when compared to the intravenous route. A similar effect on relative GA exposure was also evident as the administered dose was reduced, which suggests that as dosing rate decreases, the conversion of AA to GA is more efficient. These findings are critical to the assessment of genotoxicity of AA at low doses in the food supply, which appears to depend on total exposure to GA.

  3. Thermoluminescence and photoluminescence study of KY3F10:Ho3+ commercial phosphor powder

    NASA Astrophysics Data System (ADS)

    Debelo, N. G.; Dejene, F. B.; Roro, Kittessa

    2016-06-01

    Thermoluminescence (TL) and photoluminescence (PL) properties of KY3F10:Ho3+ phosphor powder is reported. The TL measurements were carried out for different heating rates and for various durations of UV exposure. The TL intensity increases with the duration of UV exposure up to 20 min and then decreases. A decrease of the glow peak height was observed for the glow curves with an increasing heating rate. The area under the TL-time plot is calculated for each heating rate at a constant UV dose and it is found to be constant and independent of the heating rate. It is found that the observed decrement in intensity of each glow curve following an increment in the heating rate is not attributed to the thermal quenching effect. Important TL kinetic parameters namely, the activation energy (E) and the frequency factor (s) were calculated using a variable heating rate (VHR) method. The glow peaks obey first order kinetics. PL emission spectra were also investigated at four main excitation wavelengths; namely, 362, 416, 454 and 486 nm. Green emission at 540 nm and faint red emission at 750 nm were observed for all the excitations. The green emission at 540 nm is ascribed to the 5F4–5I8 and 5S2–5I8 transitions and the faint red emission at 750 nm is due to the 5F4–5I7 and 5S2–5I7 transitions. In addition to the sharp green emission at 540 nm, a broad emission centered at 600 nm was observed for excitation wavelength of 362 nm.

  4. Gain change by adjusting the pumping wavelength in an end-pumped Nd:YVO4sub> amplifier.

    PubMed

    Nie, Mingming; Liu, Qiang; Ji, Encai; Fu, Xing; Gong, Mali

    2016-06-20

    In this paper, the performance of an end-pumped laser amplifier was experimentally studied by adjusting the pumping wavelength of a laser diode. An interesting phenomenon was observed: that the gain would decrease with an increase in absorbed pump power. The scaled output power of 0.3 at. % doped 20 mm long Nd:YVO4sub> crystal decreased from 0.48 to 0.2 W when the absorbed pump power increased from 17.5 to 17.8 W. Theoretical analysis was demonstrated according to our previous model. The long crystal length is the main reason for the observed phenomenon. This phenomenon could be utilized to enhance amplifier gain and improve thermal performance, including the maximal temperature and thermal stress of the crystal. PMID:27409123

  5. Morphologically Templated Growth of Aligned Spinel CoFe2O4sub> Nanorods

    SciTech Connect

    Zhang, Zongtao; Rondinone, Adam Justin; Ma, Jianxing; Shen, Jian; Dai, Sheng

    2005-01-01

    Uniaxially aligned CoFe{sub 2}O{sub 4} nanorods are obtained by coprecipitation of Co{sup 2+}, Fe{sub 2+}, and C{sub 2}O{sub 4}{sup 2-} ions in a microemulsion solution, and subsequent high-temperature decomposition of CoFe{sub 2}(C{sub 2}O{sub 4}){sub 3}. Each nanorod is made up of a 'tectonic' assembly of CoFe{sub 2}O{sub 4} nanocrystals. Magnetization of such SoFe{sub 2}O{sub 4} materials may lead to their use in high-density magnetic recording media and high-performance electromagnetic and spintronic devices.

  6. Megahertz-level, high-power picosecond Nd:LuVO4sub> regenerative amplifier free of period doubling.

    PubMed

    Gao, Peng; Lin, Hua; Li, Jinfeng; Guo, Jie; Yu, Haohai; Zhang, Huaijin; Liang, Xiaoyan

    2016-06-27

    We report on a high repetition rate, high-power picosecond Nd:LuVO4sub> regenerative amplifier. Period doubling caused energy instability was eliminated at megahertz-level repetition rate with the modified seeding source. A multi-pass cell was used to improve the seed pulse energy to achieve complete suppression of the onset of bifurcation. At a maximum repetition rate of 1.43 MHz, the system produced 7.0-ps-long pulses with an average output power of 25.1 W, corresponding to a pulse energy of 17.6 μJ. At 100 kHz, the pulse energy increased to 205 μJ with an average power of 20.5 W. Moreover, the injected pulses with pulse duration of 5.1 ps broadened to 8.9 ps because of gain narrowing in the amplifier. PMID:27410559

  7. New measurement of the {sup 68}Zn(4{sub 1}{sup +}) g factor combined with a reanalysis of previous data

    SciTech Connect

    Moschner, K.; Bernards, C.; Bettermann, L.; Speidel, K.-H.; Leske, J.; Bauer, C.; Moeller, T.; Honma, M.; Maier-Komor, P.; Muecher, D.

    2010-07-15

    We have remeasured and have redetermined the g factor for the 4{sub 1}{sup +} state in {sup 68}Zn following inconsistencies between earlier measurements and a recent result. We have reanalyzed several former measurements by applying an alternative analysis procedure, which allows for determining the precession effect separately for each gamma detector implying less uncertainties in the background subtraction for the relevant spectra. In addition, all measured g-factor and B(E2) data for the first 2{sup +} and 4{sup +} states in all stable even-A Zn isotopes and the radioactive {sup 62}Zn, are compared with new large-scale shell model calculations based on the most advanced effective interaction in the fpg-shell model space.

  8. Neutron diffraction study on the two-dimensional Ising system KEr(MoO{sub 4}){sub 2}

    SciTech Connect

    Mat'as, Slavomir; Dudzik, Esther; Feyerherm, Ralf; Gerischer, Sebastian; Klemke, Sebastian; Prokes, Karel; Orendacova, Alzbeta

    2010-11-01

    The magnetic properties of the two-dimensional Ising antiferromagnet KEr(MoO{sub 4}){sub 2} have been investigated below and above transition temperature T{sub N}{approx}0.95 K in zero field and in fields up to 6.5 T by means of elastic neutron-diffraction, heat-capacity, and magnetization measurements. The low-temperature signal recorded at 0.34 K by neutron diffraction is explained within a noncollinear magnetic structure model. However, additional contribution is also present when applying the external magnetic field along the c axis even at temperatures well above the magnetic transition temperature T{sub N}. Various explanations are discussed.

  9. Enhanced Thermoelectric Properties of Cu2ZnSnSe4sub> with Ga-doping

    SciTech Connect

    Wei, Kaya; Beauchemin, Laura; Wang, Hsin; Porter, Wallace D.; Martin, Joshua; Nolas, George S.

    2015-08-10

    Gallium doped Cu2ZnSnSe4sub> quaternary chalcogenides with and without excess Cu were synthesized by elemental reaction and densified using hot pressing in order to investigate their high temperature thermoelectric properties. The resistivity, , and Seebeck coefficient, S, for these materials decrease with increased Ga-doping while both mobility and effective mass increase with Ga doping. The power factor (S2/ρ) therefore increases with Ga-doping. The highest thermoelectric figure of merit (ZT = 0.39 at 700 K) was obtained for the composition that had the lowest thermal conductivity. Our results suggest an approach to achieving optimized thermoelectric properties and are part of the continuing effort to explore different quaternary chalcogenide compositions and structure types, as this class of materials continues to be of interest for thermoelectrics applications.

  10. Ionic liquid assisted microwave synthesis route towards color-tunable luminescence of lanthanide- doped BiPO4sub>

    SciTech Connect

    Cybinska, Joanna; Lorbeer, Chantal; Mudring, Anja -Verena

    2015-07-08

    Ln3+-doped (Ln=Sm, Eu, Tb, Dy) nanoparticles of BiPO4sub> with a particle size below 10 nm were synthesized in a straightforward manner from the appropriate mixture of the respective metal acetates and the task-specific ionic liquids choline or butylammonium dihydrogen-phosphate by conversion in a laboratory microwave (120 °C, 10 min). The ionic liquid acts not only as a solvent and microwave susceptor, but also as the reaction partner and nanoparticle stabilizer. The materials were thoroughly characterized not only with respect to their optical properties but also by PXRD, FT-IR, TEM techniques. Furthermore, depending on the lanthanide, the nanomaterial shows intense luminescence of different colors such as: orange (Sm3+), red (Eu3+), green (Tb3+) or even white (Dy3+).

  11. Luminescent and lasing characteristics of heavily doped Yb{sup 3+}:KY(WO{sub 4}){sub 2} crystals

    SciTech Connect

    Kisel', V E; Troshin, A E; Shcherbitskii, V G; Kuleshov, N V; Pavlyuk, A A; Brunner, F; Paschotta, R; Morier-Genoud, F; Keller, U

    2006-04-30

    The luminescence decay times are measured taking into account reabsorption for KY(WO{sub 4}){sub 2}:Yb(KYW:Yb) crystals with atomic concentrations of active ions from 0.2% to 30%. The radiative lifetime of Yb{sup 3+} ions was measured to be 233 {mu}s. The cw output power of 1.46 and 1.62 W was achieved with the slope efficiency 52% and 47% for Yb:KYW lasers with the atomic concentration of Yb{sup 3+} ions equal to 10% and 30%, respectively. Using a semiconductor mirror with a saturable absorber (SESAM) in the passive mode-locking regime, pulses of duration 194 and 180 fs were obtained at wavelengths of 1042 and 1039 nm for crystals with Yb{sup 3+} concentrations equal to 10% and 30%, respectively, the average output power being 0.63 and 0.75 W. (lasers and amplifiers)

  12. Search and Rescue Aircrewman/HH3F Avionics, 2-11. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This self-paced, individualized course, adapted from military curriculum materials for use in vocational and technical education, teaches students the skills needed to become a qualified avionics worker and aircrew rescuer on the HH-3F helicopter. The course materials consist of four pamphlets: two student workbooks and two student syllabuses. The…

  13. Lattice site dependent cathodoluminescence behavior and surface chemical changes in a Sr5(PO4)3F host

    NASA Astrophysics Data System (ADS)

    Nagpure, I. M.; Pitale, Shreyas S.; Coetsee, E.; Ntwaeaborwa, O. M.; Terblans, J. J.; Swart, H. C.

    2012-05-01

    Eu activated Sr5(PO4)3F phosphor powders have been subjected to the electron bombardment at 2 keV (10 μA) at an oxygen pressure of 1×10-6 Torr. The synthesized Sr5(PO4)3F phosphor was identical to the hexagonal apatite structure, with the Sr present at two different sites Cs (S1) and C3 (S2) in the Sr5(PO4)3F host, as inferred from the crystallographic study. Cathodoluminescence (CL) and Auger electron spectroscopy of the phosphor excited by the same electron beam were used to monitor changes in the surface state during prolonged electron bombardment. A direct correlation between the surface reactions and the degradation of the CL brightness was observed. Both C and F were depleted from the surface during electron bombardment. The postulated mechanism for the electron stimulated chemical reactions on the phosphor surface is electron beam dissociation of molecular species to atomic species, which subsequently react with C to form volatile compounds CO2, CH4, etc. and with Sr5(PO4)3F to form a non luminescence layer of metal oxides of Sr and P.

  14. MULTIPLE-SITE CARCINOGENICITY OF BENZENE IN FISCHER 344 RATS AND B6C3F MICE

    EPA Science Inventory

    Two-year toxicology and carcinogenesis studies of benzene were conducted in groups of 50 F344/N rats and 50 B6C3F1 mice of each sex and for each of three exposure doses and vehicle controls. hese studies were conducted because of large production volume and widespread human expos...

  15. Evaluation of Radial Flow Fluidized Filter (R3F) Followed by Microfiltration and Ultrafiltration Systems in Calimesa, California

    EPA Science Inventory

    U.S. EPA coordinated a field study with South Mesa Water Utility to look for treatment alternatives for California State Project Water in the small community of Calimesa, California. EPA evaluated the performance of a system comprised of Radial Flow Fluidized Filtration (R3f) fo...

  16. Immunotoxicological Profile of Chloroform in Female B6c3f1 Mice When Administered In Drinking Water

    EPA Science Inventory

    Chloroform can be formed as a disinfection by-product during water chlorination, one of the primary modalities for purifying municipal water supplies for human consumption. The goal of this study was to characterize the immunotoxic effects of chloroform in female B6C3F1 mice when...

  17. 29 CFR 780.105 - “Primary” and “secondary” agriculture under section 3(f).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false âPrimaryâ and âsecondaryâ agriculture under section 3(f... EXEMPTIONS APPLICABLE TO AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT General Scope of Agriculture Introductory § 780.105 “Primary” and...

  18. 29 CFR 780.105 - “Primary” and “secondary” agriculture under section 3(f).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false âPrimaryâ and âsecondaryâ agriculture under section 3(f... EXEMPTIONS APPLICABLE TO AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT General Scope of Agriculture Introductory § 780.105 “Primary” and...

  19. 29 CFR 780.105 - “Primary” and “secondary” agriculture under section 3(f).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false âPrimaryâ and âsecondaryâ agriculture under section 3(f... EXEMPTIONS APPLICABLE TO AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT General Scope of Agriculture Introductory § 780.105 “Primary” and...

  20. 29 CFR 780.105 - “Primary” and “secondary” agriculture under section 3(f).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false âPrimaryâ and âsecondaryâ agriculture under section 3(f... EXEMPTIONS APPLICABLE TO AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT General Scope of Agriculture Introductory § 780.105 “Primary” and...

  1. 29 CFR 780.105 - “Primary” and “secondary” agriculture under section 3(f).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false âPrimaryâ and âsecondaryâ agriculture under section 3(f... EXEMPTIONS APPLICABLE TO AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT General Scope of Agriculture Introductory § 780.105 “Primary” and...

  2. HEPATOCARCINOGENICITY OF CHLORAL HYDRATE, 2-CHLOROACETALDEHYDE, AND DICHLOROACETIC ACID IN THE MALE B6C3F1 MOUSE

    EPA Science Inventory

    Chloral hydrate (CH) and 2-chloroacetaldehyde (CAA) have been identified as chlorination by-products in drinking water. oth chemicals are genotoxic, but their carcinogenic potential had not been adequately tested. hese bioassays were conducted using male B6C3F1 mice exposed to 1 ...

  3. Altered global histone-trimethylation code and H3F3A-ATRX mutation in pediatric GBM.

    PubMed

    Pathak, Pankaj; Jha, Prerana; Purkait, Suvendu; Sharma, Vikas; Suri, Vaishali; Sharma, Mehar C; Faruq, Mohammed; Suri, Ashish; Sarkar, Chitra

    2015-02-01

    Mutations in H3.3-ATRX-DAXX chromatin remodeling pathway have been reported in pediatric GBMs. H3.3 (H3F3A) mutations may affect transcriptional regulation by altered global histone-methylation. Therefore, we analyzed yet partly understood global histone code (H3K-4/9/27/36) trimethylation pattern in H3F3A-ATRX mutants and wild-type. H3F3A, HIST1H3B, IDH1, ATRX, DAXX and Tp53 mutations were identified by sequencing/immunohistochemistry in 27 pediatric GBMs. Global histone-methylation H3K-4/9/27/36me3 and Polycomb-protein EZH2 expression were evaluated by immunohistochemistry. H3F3A-ATRX mutation was observed in 66.7 % (18/27) of pediatric GBMs. K27M and G34R-H3F3A mutations were found in 37 % (10/27) and 14.8 % (4/27) patients respectively. G34V-H3F3A, HIST1H3B and IDH1 mutations were absent. Notably, commonest global histone-methylation mark lost was H3K27me3 (17/25, 68 %) followed by H3K4me3 (45.5 %, 10/22) and H3K9me3 (18.2 %, 4/22). Global H3K36me3 showed no loss. Most significant observation was loss of one or more histone-trimethylation mark in 80 % (20/25) pediatric GBMs. Notably, simultaneous loss of H3K27me3 and H3K4me3 were present in 7/22 (31.8 %) of pediatric GBMs. Low expression of EZH2 was found in 12/24 (50 %) of cases. However no significant correlation of loss of histone-marks or EZH2 expression with H3F3A-ATRX mutants (loss of at least one histone-marks in 87.5 % (14/16) cases) versus wild-types (loss of at least one histone-marks in 75 % (6/8) cases) was seen. The present study highlights for the first time combinatorial loss of one or more histone-trimethylation marks associated with majority of pediatric GBMs and the finding suggests significant role of histone-code in the molecular biology that underlies pediatric GBMs. Hence therapies for patients with particular combinations of histone modifications present opportunity to design innovative patient-tailored treatment protocols. PMID:25479829

  4. Optical emission spectroscopic studies and comparisons of CH{sub 3}F/CO{sub 2} and CH{sub 3}F/O{sub 2} inductively coupled plasmas

    SciTech Connect

    Lou, Qiaowei; Kaler, Sanbir; Donnelly, Vincent M. Economou, Demetre J.

    2015-03-15

    A CH{sub 3}F/CO{sub 2} inductively coupled plasma (ICP), sustained in a compact plasma reactor, was investigated as a function of power (5–400 W) and feed gas composition, at a pressure of 10 mTorr, using optical emission spectroscopy and rare gas actinometry. Number densities of H, F, and O increased rapidly between 74% and 80% CO{sub 2}, ascribed to the transition from polymer-covered to polymer-free reactor walls, similar to that found previously in CH{sub 3}F/O{sub 2} ICPs at 48% O{sub 2}. Below 40% O{sub 2} or CO{sub 2}, relative emission intensity ratios were almost identical for most key species in CH{sub 3}F/O{sub 2} and CH{sub 3}F/CO{sub 2} ICPs except for higher OH/Xe (a qualitative measure of OH and H{sub 2}O densities) over the full range of CH{sub 3}F/O{sub 2} composition. The number density of H, F, and O increased with power in CH{sub 3}F/CO{sub 2} (20%/80%) plasmas (polymer-free walls), reaching 4.0, 0.34, and 1.6 × 10{sup 13}/cm{sup 3}, respectively, at 300 W. The CO number density increased with power and was estimated, based on self-actinometry, to be 8.8 × 10{sup 13}/cm{sup 3} at 300 W. The CO{sub 2} number density was independent of power below 40 W (where very little decomposition occurred), and then decreased rapidly with increasing power, reaching 2.8 × 10{sup 13}/cm{sup 3} at 300 W, corresponding to 83% dissociation. Films deposited on p-Si, 10 cm from the open, downstream end of the plasma reactor, were analyzed by x-ray photoelectron spectroscopy. Between 10% and 40% CO{sub 2} or O{sub 2} addition to CH{sub 3}F, film deposition rates fell and O content in the films increased. Faster deposition rates in CH{sub 3}F/CO{sub 2} plasmas were ascribed mainly to a larger thermodynamic driving force to form solid carbon, compared with CH{sub 3}F/O{sub 2} plasmas. Oxygen content in the films increased with increasing CO{sub 2} or O{sub 2} addition, but for the same deposition rate, no substantial differences were

  5. High Resolution Infrared Spectroscopy of CH_3F-({ortho}-H_2){n} Cluster in Solid {para}-H_2

    NASA Astrophysics Data System (ADS)

    Kawasaki, Hiroyuki; Mizoguchi, Asao; Kanamori, Hideto

    2015-06-01

    The absorption spectrum of the ν3 (C-F stretching) mode of CH_3F in solid {para}-H_2 by FTIR showed a series of equal interval peaks. Their interpretation was that the {}-th peak of this series was due to CH_3F-({ortho}-H_2){n} clusters which were formed CH_3F and {n}'s {ortho}-H_2 in first nearest neighbor sites of the {para}-H_2 crystal with {hcp} structure. In order to understand this system in more detail, we have studied these peaks, especially {n} = 0 - 3 corresponding to 1037 - 1041 wn, by using high-resolution and high-sensitive infrared quantum cascade (QC) laser spectroscopy. Before now, we found many peaks around each {n}-th peak of the cluster, which we didn't know their origins. We observed photochromic phenomenon of these peaks by taking an advantage of the high brightness of the laser. In this study, we focus on satellite series consisting of six peaks which locate at the lower energy side of each main peak. All the peaks showed a common red shouldered line profile, which corresponds to partly resolved transitions of {ortho}- and {para}- CH_3F. The spectral pattern and time behavior of the peaks may suggest that these satellite series originate from a family of CH_3F clusters involving {ortho}-H_2 in second nearest neighbor sites. A model function assuming this idea is used to resolve the observed spectrum into each Lorentzian component, and then some common features of the satellite peaks are extracted and the physical meanings of them will be discussed. K. Yoshioka and D. T. Anderson, J. Chem. Phys. 119 (2003) 4731-4742 A. R. W. McKellar, A. Mizoguchi, and H. Kanamori, J. Chem. Phys. 135 (2011) 124511 A. R. W. McKellar, A. Mizoguchi, and H. Kanamori, Phys. Chem. Chem. Phys. 13 (2011) 11587-11589.

  6. The cooling capabilities of C2F6/C3F8 saturated fluorocarbon blends for the ATLAS silicon tracker

    NASA Astrophysics Data System (ADS)

    Bates, R.; Battistin, M.; Berry, S.; Bitadze, A.; Bonneau, P.; Bousson, N.; Boyd, G.; Botelho-Direito, J.; Crespo-Lopez, O.; DiGirolamo, B.; Doubek, M.; Giugni, D.; Hallewell, G.; Lombard, D.; Katunin, S.; McMahon, S.; Nagai, K.; Robinson, D.; Rossi, C.; Rozanov, A.; Vacek, V.; Zwalinski, L.

    2015-03-01

    We investigate and address the performance limitations of the ATLAS silicon tracker fluorocarbon evaporative cooling system operation in the cooling circuits of the barrel silicon microstrip (SCT) sub-detector. In these circuits the minimum achievable evaporation temperatures with C3F8 were higher than the original specification, and were thought to allow an insufficient safety margin against thermal runaway in detector modules subject to a radiation dose initially foreseen for 10 years operation at LHC. We have investigated the cooling capabilities of blends of C3F8 with molar admixtures of up to 25% C2F6, since the addition of the more volatile C2F6 component was expected to allow a lower evaporation temperature for the same evaporation pressure.A custom built recirculator allowed the in-situ preparation of C2F6/C3F8 blends. These were circulated through a representative mechanical and thermal setup reproducing an as-installed ATLAS SCT barrel tracker cooling circuit. Blend molar compositions were verified to a precision of 3.10-3 in a custom ultrasonic instrument.Thermal measurements in a range of C2F6/C3F8 blends were compared with measurements in pure C3F8. These indicated that a blend with 25% C2F6 would allow a reduction in evaporation temperature of around 9oC to below -15oC, even at the highest module power dissipations envisioned after 10 years operation at LHC. Such a reduction would allow more than a factor two in safety margin against temperature dependant leakage power induced thermal runaway.Furthermore, a blend containing up to 25% C2F6 could be circulated without changes to the on-detector elements of the existing ATLAS inner detector evaporative cooling system.

  7. Syntheses, crystal structures and vibrational spectra of KLn(SO{sub 4}){sub 2}.H{sub 2}O (Ln=La, Nd, Sm, Eu, Gd, Dy)

    SciTech Connect

    Kazmierczak, Karolina; Hoeppe, Henning A.

    2010-09-15

    The potassium lanthanide double sulphates KLn(SO{sub 4}){sub 2}.H{sub 2}O (Ln=La, Nd, Sm, Eu, Gd, Dy) were obtained by evaporation of aqueous reaction mixtures of rare earth (III) sulphates and potassium thiocyanate at 298 K. X-ray single-crystal investigations show that KLn(SO{sub 4}){sub 2}.H{sub 2}O (Ln=Nd, Sm, Eu, Gd, Dy) crystallise monoclinically (Ln=Sm: P2{sub 1}/c, Z=4, a=10.047(1), b=8.4555(1), c=10.349(1) A, wR2=0.060, R1=0.024, 945 reflections, 125 parameters) while KLa(SO{sub 4}){sub 2}.H{sub 2}O adopts space group P3{sub 2}21 (Z=3, a=7.1490(5), c=13.2439(12) A, wR2=0.038, R1=0.017, 695 reflections, 65 parameters). The coordination environment of the lanthanide ions in KLn(SO{sub 4}){sub 2}.H{sub 2}O is different in the case of the Nd/Sm/Gd and the Eu/Dy compounds, respectively. In the first case the Ln atoms are nine-fold coordinated in contrast to the latter where the Ln ions are eight-fold coordinated by oxygen atoms. The vibrational spectra of KLn(SO{sub 4}){sub 2}.H{sub 2}O and the UV-vis reflection spectra of KEu(SO{sub 4}){sub 2}.H{sub 2}O and KNd(SO{sub 4}){sub 2}.H{sub 2}O are also reported. - Graphical abstract: The lanthanide potassium double sulphates exhibit an unexpected change in the coordination mode by a simple rotation of sulphate tetrahedron 2.

  8. Synthesis, structural and spectroscopic properties of acentric triple molybdate Cs{sub 2}NaBi(MoO{sub 4}){sub 3}

    SciTech Connect

    Savina, A.A.; Atuchin, V.V.; Solodovnikov, S.F.; Solodovnikova, Z.A.; Krylov, A.S.; Maximovskiy, E.A.; Molokeev, M.S.; Oreshonkov, A.S; Pugachev, A.M.; and others

    2015-05-15

    New ternary molybdate Cs{sub 2}NaBi(MoO{sub 4}){sub 3} is synthesized in the system Na{sub 2}MoO{sub 4}–Cs{sub 2}MoO{sub 4}–Bi{sub 2}(MoO{sub 4}){sub 3}. The structure of Cs{sub 2}NaBi(MoO{sub 4}){sub 3} of a new type is determined in noncentrosymmetric space group R3c, a=10.6435(2), c=40.9524(7) Å, V=4017.71(13) Å{sup 3}, Z=12 in anisotropic approximation for all atoms taking into account racemic twinning. The structure is completely ordered, Mo atoms are tetrahedrally coordinated, Bi(1) and Bi(2) atoms are in octahedra, and Na(1) and Na(2) atoms have a distorted trigonal prismatic coordination. The Cs(1) and Cs(2) atoms are in the framework cavities with coordination numbers 12 and 10, respectively. No phase transitions were found in Cs{sub 2}NaBi(MoO{sub 4}){sub 3} up to the melting point at 826 K. The compound shows an SHG signal, I{sub 2w}/I{sub 2w}(SiO{sub 2})=5 estimated by the powder method. The vibrational properties are evaluated by Raman spectroscopy, and 26 narrow lines are measured. - Graphical abstract: - Highlights: • The crystal structure of Cs{sub 2}NaBi(MoO{sub 4}){sub 3} is defined. • The molybdate Cs{sub 2}NaBi(MoO{sub 4}){sub 3} is stable up to melting point at 826 K. • Vibrational properties of Cs{sub 2}NaBi(MoO{sub 4}){sub 3} are evaluated by Raman spectroscopy.

  9. Synthesis, structures and properties of the new lithium cobalt(II) phosphate Li{sub 4}Co(PO{sub 4}){sub 2}

    SciTech Connect

    Glaum, R.; Gerber, K.; Schulz-Dobrick, M.

    2012-04-15

    {alpha}-Li{sub 4}Co(PO{sub 4}){sub 2} has been synthesized and crystallized by solid-state reactions. The new phosphate crystallizes in the monoclinic system (P2{sub 1}/a, Z=4, a=8.117(3) Angstrom-Sign , b=10.303(8) Angstrom-Sign , c=8.118(8) Angstrom-Sign , {beta}=104.36(8) Angstrom-Sign ) and is isotypic to {alpha}-Li{sub 4}Zn(PO{sub 4}){sub 2}. The structure of {alpha}-Li{sub 4}Co(PO{sub 4}){sub 2} has been determined from single-crystal X-ray diffraction data {l_brace}R{sub 1}=0.040, wR{sub 2}=0.135, 2278 unique reflections with F{sub o}>4{sigma}(F{sub o}){r_brace}. The crystal structure, which might be regarded as a superstructure of the wurtzite structure type, is build of layers of regular CoO{sub 4}, PO{sub 4} and Li1O{sub 4} tetrahedra. Lithium atoms Li2, Li3 and Li4 are located between these layers. Thermal investigations by in-situ XRPD, DTA/TG and quenching experiments suggest decomposition followed by formation and phase transformation of Li{sub 4}Co(PO{sub 4}){sub 2}: {alpha}-Li{sub 4}Co(PO{sub 4}){sub 2} Long-Rightwards-Double-Arrow {sup 442 Degree-Sign C}{beta}-Li{sub 3}PO{sub 4}+LiCoPO{sub 4} Rightwards-Harpoon-Over-Leftwards-Harpoon {sup 773 Degree-Sign C}{beta}-Li{sub 4}Co(PO{sub 4}){sub 2} Long-Rightwards-Double-Arrow {sup quenchingto25 Degree-Sign C}{alpha}-Li{sub 4} Co(PO{sub 4}){sub 2} According to HT-XRPD at {theta}=850 Degree-Sign C{beta}-Li{sub 4}Co(PO{sub 4}){sub 2} (Pnma, Z=2, 10.3341(8) A, b=6.5829(5) A, c=5.0428(3) Angstrom-Sign ) is isostructural to {gamma}-Li{sub 3}PO{sub 4}. The powder reflectance spectrum of {alpha}-Li{sub 4}Co(PO{sub 4}){sub 2} shows the typical absorption bands for the tetrahedral chromophore [Co{sup II}O{sub 4}]. - Graphical abstract: The complex formation and decomposition behavior of Li{sub 4}Co(PO{sub 4}){sub 2} with temperature has been elucidated. The crystal structure of its {alpha}-phase was determined from single crystal data, HT-XRPD allowed derivation of a structure model for the {beta}-phase. Both

  10. The mechanism of the area negative thermal expansion in KBe2BO3F2 family crystals: A first-principles study

    NASA Astrophysics Data System (ADS)

    Jiang, Xingxing; Molokeev, Maxim S.; Li, Wei; Wu, Shaofan; Lin, Zheshuai; Wu, Yicheng; Chen, Chuangtian

    2016-02-01

    A very recent study demonstrated that the KBe2BO3F2 (KBBF) family of crystals, including KBBF, RbBe2BO3F2, and CsBe2BO3F2, are the only known borates exhibiting a rarely occurring isotropic area negative thermal expansion (NTE) behavior, over a very large temperature range. In the present work, the NTE mechanism in these crystals is comprehensively investigated using the first-principles calculations. It is revealed that the area NTE behavior mainly originates from the concerted distortion of [BeO3F] tetrahedra in the two-dimensional [Be2BO3F2]∞ framework with respect to temperature, while the [BO3] triangles remain almost rigid. Moreover, the different magnitude of NTE effect in the three crystals is attributed to the interaction difference between the alkali metal atoms (K, Rb, or Cs) and the [Be2BO3F2]∞ layer.

  11. Three-dimensional frameworks of cubic (NH{sub 4}){sub 5}Ga{sub 4}SbS{sub 10}, (NH{sub 4}){sub 4}Ga{sub 4}SbS{sub 9}(OH) {small _bullet} H{sub 2}O, and (NH{sub 4}){sub 3}Ga{sub 4}SbS{sub 9}(OH{sub 2}) {small_bullet} 2H{sub 2}O.

    SciTech Connect

    Mertz, J. L.; Ding, N.; Kanatzidis, M. G.

    2009-11-11

    Three new isostructural open-framework sulfides, (NH{sub 4}){sub 5}Ga{sub 4}SbS{sub 10} (1), (NH{sub 4}){sub 4}Ga{sub 4}SbS{sub 9}(OH) {sm_bullet} H{sub 2}O (2a), and (NH{sub 4}){sub 3}Ga{sub 4}SbS{sub 9}(H{sub 2}O) {sm_bullet} 2H{sub 2}O (2b), were synthesized under basic hydrothermal conditions using ammonium hydroxide as the structure-directing agent. The structures feature a three-dimensional open framework comprised of adamantane [Ga{sub 4}Q{sub 10}]{sup 8-} clusters linked with Sb{sup 3+} centers. The compounds are wide gap semiconductors, crystallize in the chiral space group P2{sub 1}3, and represent a new structure type. They exhibit nonlinear optical properties.

  12. Exchange bias effect in Au-Fe3O4sub> dumbbell nanoparticles induced by the charge transfer from gold

    SciTech Connect

    Feygenson, Mikhail; Bauer, John C; Gai, Zheng; Marques, Carlos; Aronson, Meigan C.; Teng, Xiaowei; Su, Dong; Stanic, Vesna; Urban, Volker S; Kevin, Beyer; Dai, Sheng

    2015-08-10

    We have studied the origin of the exchange bias effect in the Au-Fe3O4sub> dumbbell nanoparticles in two samples with different sizes of the Au seed nanoparticles (4.1 and 2.7 nm) and same size of Fe3O4sub> nanoparticles (9.8 nm). The magnetization, small-angle neutron scattering, synchrotron x-ray diffraction and scanning transmission electron microscope measurements determined the antiferromagnetic FeO wüstite phase within Fe3O4sub> nanoparticles, originating at the interface with the Au nanoparticles. The interface between antiferromagnetic FeO and ferrimagnetic Fe3O4sub> is giving rise to the exchange bias effect. The strength of the exchange bias fields depends on the interfacial area and lattice mismatch between both phases. We propose that the charge transfer from the Au nanoparticles is responsible for a partial reduction of the Fe3O4sub> into FeO phase at the interface with Au nanoparticles. The Au-O bonds are formed across the interface to accommodate an excess of oxygen released during the reduction of magnetite.

  13. CuCo2O4sub> ORR/OER Bi-functional catalyst: Influence of synthetic approach on performance

    SciTech Connect

    Serov, Alexey; Andersen, Nalin I.; Roy, Aaron J.; Matanovic, Ivana; Artyushkova, Kateryna; Atanassov, Plamen

    2015-02-07

    A series of CuCo2O4sub> catalysts were synthesized by pore forming, sol-gel, spray pyrolysis and sacrificial support methods. Catalysts were characterized by XRD, SEM, XPS and BET techniques. The electrochemical activity for the oxygen reduction and oxygen evolution reactions (ORR and OER) was evaluated in alkaline media by RRDE. Density Functional Theory was used to identify two different types of active sites responsible for ORR/OER activity of CuCo2O4sub> and it was found that CuCo2O4 sub>can activate the O-O bond by binding molecular oxygen in bridging positions between Co or Co and Cu atoms. It was found that the sacrificial support method (SSM) catalyst has the highest performance in both ORR and OER and has the highest content of phase-pure CuCo2O4sub>. It was shown that the presence of CuO significantly decreases the activity in oxygen reduction and oxygen evolution reactions. As a result, the half-wave potential (E1/2) of CuCo2O4sub>-SSM was found as 0.8 V, making this material a state-of-the-art, unsupported oxide catalyst.

  14. Microwave-assisted preparation of Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C composite with high-rate capacity

    SciTech Connect

    Yan, Ji; Mao, Wen-feng; Xie, Hui; Tang, Zhi-yuan; Yuan, Wei; Chen, Xue-cheng; Xu, Qiang; Ma, Li

    2012-06-15

    Highlights: ► High-rate Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C is firstly reported via a microwave-assisted method. ► The reduced particle size is responsible for the improved high-rate performance. ► A discharge capacity of 100 mAh g{sup −1} is obtained at 20 C charge–discharge rate. -- Abstract: A fast sol–gel assisted microwave heating approach has been developed for the synthesis of high-rate Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C cathode material. This approach can synthesize Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C particles with high purity and good crystallinity in 12 min at a low microwave power of 320 W. In the voltage range of 3.0–4.3 V, the obtained Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C delivers a reversible discharge capacity of 100 mAh g{sup −1} after 100 cycles at 20 °C, exhibiting excellent rate capability and cycling performance. The rate-recovery performance also suggests that the Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C material possesses excellent structure stability after high-rate cycles, presenting excellent application value in high-power lithium ion batteries.

  15. First-Principles Design of a Deep-Ultraviolet Nonlinear-Optical Crystal from KBe2BO3F2 to NH4Be2BO3F2.

    PubMed

    Kang, Lei; Luo, Siyang; Peng, Guang; Ye, Ning; Wu, Yicheng; Chen, Chuangtian; Lin, Zheshuai

    2015-11-16

    KBe2BO3F2 (KBBF) is so far the sole nonlinear-optical (NLO) material that can be practically applied in the deep-ultraviolet (DUV) region. For the purpose of overcoming its layering tendency in crystal growth, herein a computer-assisted material design system is employed to design a new KBBF analogue, ammonia beryllium fluoroborate (NH4Be2BO3F2, ABBF). The first-principles calculations demonstrate that ABBF possesses NLO properties very close to those of KBBF, thus exhibiting good DUV NLO capability. Moreover, owing to the relatively strong chemical binding between layers, ABBF would have a better growth habit compared with KBBF. Upon synthesis, ABBF would be a very promising DUV NLO material. PMID:26509702

  16. Structural features of AgCaCdMg{sub 2}(PO{sub 4}){sub 3} and AgCd{sub 2}Mg{sub 2}(PO{sub 4}){sub 3}, two new compounds with the alluaudite-type structure, and their catalytic activity in butan-2-ol conversion

    SciTech Connect

    Kacimi, Mohammed; Ziyad, Mahfoud; Hatert, Frederic . E-mail: fhatert@ulg.ac.be

    2005-04-20

    AgCaCdMg{sub 2}(PO{sub 4}){sub 3} and AgCd{sub 2}Mg{sub 2}(PO{sub 4}){sub 3}, two new compounds with the alluaudite-type structure, were synthesized by a solid state reaction in air at 750 deg. C. The X-ray powder diffraction pattern of AgCaCdMg{sub 2}(PO{sub 4}){sub 3} indicates the presence of small amounts of (Ca, Mg){sub 3}(PO{sub 4}){sub 2} with the whitlockite structure, as impurity, whereas AgCd{sub 2}Mg{sub 2}(PO{sub 4}){sub 3} is constituted by pure alluaudite. The Rietveld refinements of the X-ray powder diffraction patterns indicate an ordered cationic distribution for AgCd{sub 2}Mg{sub 2}(PO{sub 4}){sub 3}, with Ag on A(2)', Cd on A(1) and M(1), and Mg on M(2), whereas a disordered distribution of Cd and Ca between the A(1) and M(1) sites is observed for AgCaCdMg{sub 2}(PO{sub 4}){sub 3}. The catalytic properties of these compounds has been measured in reaction of butan-2-ol dehydrogenation. In the absence of oxygen, both samples exhibit poor dehydrogenation activity. All samples displayed no dehydration activity. Introduction of oxygen into the feed changed totally the catalytic behavior of the catalysts. The production of methyl ethyl ketone increases with time on stream and the reaction temperature. AgCaCdMg{sub 2}(PO{sub 4}){sub 3} is more efficient than AgCd{sub 2}Mg{sub 2}(PO{sub 4}){sub 3}.

  17. X-ray and Neutron Diffraction Studies of Rb{sub 4}LiH{sub 3}(XO{sub 4}){sub 4} (X = S, Se) Single Crystals

    SciTech Connect

    Troyanov, S.I.; Snigireva, E.M.; Ling, C.D.

    2004-11-01

    Rb{sub 4}LiH{sub 3}(SeO{sub 4}){sub 4} single crystals (1) are studied by the X-ray diffraction method at 180 K and Rb{sub 4}LiH{sub 3}(SO{sub 4}){sub 4} single crystals (2a-2c) are studied by the neutron diffraction method at 298 K (2a and 2b) and 480 K (2c). It is established that isostructural single crystals 1 and 2 (sp. gr. P4{sub 1}) have analogous systems of hydrogen bonds: chains of four XO{sub 4} tetrahedra linked by three H bonds with the central bond (2.49 A) being somewhat shorter than the terminal ones (2.52-2.54 A). In the high-temperature 2c phase, the amplitudes of atomic thermal vibrations and the degree of proton disorder in the central hydrogen bond have somewhat elevated values.

  18. Mechanism of the low thermal expansion in {alpha}-Hf{sub 2}O(PO{sub 4}){sub 2} and its zirconium analog

    SciTech Connect

    Wallez, Gilles Bregiroux, Damien; Quarton, Michel

    2008-06-15

    The thermal expansion of recently characterized {alpha}-Zr{sub 2}O(PO{sub 4}){sub 2} and {alpha}-Hf{sub 2}O(PO{sub 4}){sub 2} is found to be very low (respectively 2.6 and 2.9x10{sup -6} K{sup -1}, 20-900 deg. C). High-temperature X-ray diffraction and Rietveld analysis allowed to identify a dual contraction mechanism, involving a classical ring deformation and the rocking of bridging oxygens. - Graphical abstract: Compared to other zirconium phosphates, {alpha}-Zr{sub 2}O(PO{sub 4}){sub 2} shows a remarkable low thermal expansion of 2.6x10{sup -6} K{sup -1}.

  19. Intrinsic quantum anomalous Hall effect in the kagome lattice Cs2LiMn3F12

    DOE PAGESBeta

    Xu, Gang; Lian, Biao; Zhang, Shou -Cheng

    2015-10-27

    In a kagome lattice, the time reversal symmetry can be broken by a staggered magnetic flux emerging from ferromagnetic ordering and intrinsic spin-orbit coupling, leading to several well-separated nontrivial Chern bands and intrinsic quantum anomalous Hall effect. Based on this idea and ab initio calculations, we propose the realization of the intrinsic quantum anomalous Hall effect in the single layer Cs2Mn3F12 kagome lattice and on the (001) surface of a Cs2LiMn3F12 single crystal by modifying the carrier coverage on it, where the band gap is around 20 meV. Furthermore, a simplified tight binding model based on the in-plane ddσ antibondingmore » states is constructed to understand the topological band structures of the system.« less

  20. Intrinsic Quantum Anomalous Hall Effect in the Kagome Lattice Cs2 LiMn3 F12

    NASA Astrophysics Data System (ADS)

    Xu, Gang; Lian, Biao; Zhang, Shou-Cheng; Zhang's Group Team

    In a kagome lattice, the time reversal symmetry can be broken by a staggered magnetic flux emerging from the ferromagnetic ordering and intrinsic spin-orbit coupling, leading to several well-separated nontrivial Chern bands and intrinsic quantum anomalous Hall effect. Based on this idea and ab initio calculations, we propose the realization of the intrinsic quantum anomalous Hall effect in the single layer Cs2Mn3F12 kagome lattice and on the (001) surface of a Cs2LiMn3F12 single crystal by modifying the carrier coverage on it, where the band gap is around 20 meV. Moreover, a simplified tight binding model based on the inplane dd σ antibonding states is constructed to understand the topological band structures of the system.

  1. Intrinsic Quantum Anomalous Hall Effect in the Kagome Lattice Cs2 LiMn3 F12

    NASA Astrophysics Data System (ADS)

    Xu, Gang; Lian, Biao; Zhang, Shou-Cheng

    2015-10-01

    In a kagome lattice, the time reversal symmetry can be broken by a staggered magnetic flux emerging from ferromagnetic ordering and intrinsic spin-orbit coupling, leading to several well-separated nontrivial Chern bands and intrinsic quantum anomalous Hall effect. Based on this idea and ab initio calculations, we propose the realization of the intrinsic quantum anomalous Hall effect in the single layer Cs2Mn3F12 kagome lattice and on the (001) surface of a Cs2LiMn3F12 single crystal by modifying the carrier coverage on it, where the band gap is around 20 meV. Moreover, a simplified tight binding model based on the in-plane d d σ antibonding states is constructed to understand the topological band structures of the system.

  2. Nonperturbative tests for asymptotic freedom in the PT-symmetric (-{phi}{sup 4}){sub 3+1} theory

    SciTech Connect

    Shalaby, Abouzeid; Al-Thoyaib, Suleiman S.

    2010-10-15

    In the literature, the asymptotic freedom property of the (-{phi}{sup 4}) theory is always concluded from real-line calculations while the theory is known to be a non-real-line one. In this article, we test the existence of the asymptotic freedom in the (-{phi}{sup 4}){sub 3+1} theory using the mean field approach. In this approach and contrary to the original Hamiltonian, the obtained effective Hamiltonian is rather a real-line one. Accordingly, this work resembles the first reasonable analysis for the existence of the asymptotic freedom property in the PT-symmetric (-{phi}{sup 4}) theory. In this respect, we calculated three different amplitudes of different positive dimensions (in mass units) and find that all of them go to very small values at high energy scales (small coupling) in agreement with the spirit of the asymptotic freedom property of the theory. To test the validity of our calculations, we obtained the asymptotic behavior of the vacuum condensate in terms of the coupling, analytically, and found that the controlling factor {Lambda} has the value ((4{pi}){sup 2}/6)=26.319 compared to the result {Lambda}=26.3209 from the literature, which was obtained via numerical predictions. We assert that the nonblowup of the massive quantities at high energy scales predicted in this work strongly suggests the possibility of the solution of the famous hierarchy puzzle in a standard model with the PT-symmetric Higgs mechanism.

  3. SU(4){sub L} x U(1){sub X} three-family model for the electroweak interaction

    SciTech Connect

    Sanchez, Luis A.; Wills-Toro, Luis A.; Zuluaga, Jorge I.

    2008-02-01

    An extension of the gauge group SU(2){sub L} x U(1){sub Y} of the standard model to the symmetry group SU(4){sub L} x U(1){sub X} (3-4-1 for short) is presented. The model does not contain exotic electric charges and anomaly cancellation is achieved with a family of quarks transforming differently from the other two, thus leading to FCNC. By introducing a discrete Z{sub 2} symmetry we obtain a consistent fermion mass spectrum, and avoid unitarity violation of the Cabibbo-Kobayashi-Maskawa mixing matrix arising from the mixing of ordinary and exotic quarks. The neutral currents coupled to all neutral vector bosons are studied, and by using CERN LEP and SLAC Linear Collider data at Z-pole and atomic parity violation data, we bound parameters of the model related to tree-level Z-Z{sup '} mixing. These parameters are further constrained by using experimental input from neutral meson mixing in the analysis of sources of FCNC present in the model. Constraints coming from the contribution of exotic particles to the one-loop oblique electroweak parameters S, T and U are also briefly discussed. Finally, a comparison is done of the predictions of different classes of 3-4-1 models without exotic electric charges.

  4. Compact KGd(WO4sub>)2 picosecond pulse-train synchronously pumped broadband Raman laser.

    PubMed

    Gao, Xiao Qiang; Long, Ming Liang; Meng, Chen

    2016-08-20

    We demonstrate an efficient approach to realizing an extra-cavity, synchronously pumped, stimulated Raman cascaded process under low repetition frequency (1 kHz) pump conditions. We also construct a compact KGd(WO4sub>)2 (KGW) crystal picosecond Raman laser that has been configured as the developed method. A pulse-train green laser pumped the corresponding 70 mm long KGW crystal Raman cavity. The pulse train contains six pulses, about 800 ps separated, for every millisecond; thus, it can realize synchronous pumping between pump pulse and the pumped Raman cavity. The investigated system produced a collinear Raman laser output that includes six laser lines covering the 532 to 800 nm spectra. This is the first report on an all-solid-state, high-average-power picosecond collinear multi-wavelength (more than three laser components) laser to our knowledge. This method has never been reported on before in the synchronously pumped stimulated Raman scattering (SRS) realm. PMID:27556971

  5. Magnetic susceptibility, specific heat and magnetic structure of CuNi{sub 2}(PO{sub 4}){sub 2}

    SciTech Connect

    Escobal, Jaione; Pizarro, Jose L.; Mesa, Jose L. . E-mail: joseluis.mesa@ehu.es; Larranaga, Aitor; Fernandez, Jesus Rodriguez; Arriortua, Maria I.; Rojo, Teofilo

    2006-10-15

    CuNi{sub 2}(PO{sub 4}){sub 2} phosphate has been synthesized by the ceramic method at 800 deg. C in air. The crystal structure consists of a three-dimensional skeleton constructed from MO{sub 4} (M{sup II} =Cu and Ni) planar squares and M{sub 2}O{sub 8} dimers with square pyramidal geometry, which are interconnected by (PO{sub 4}){sup 3-} oxoanions with tetrahedral geometry. The magnetic behavior has been studied on powdered sample by using susceptibility, specific heat and neutron diffraction data. The bimetallic copper(II)-nickel(II) orthophosphate exhibits a three-dimensional magnetic ordering at, approximately, 29.8 K. However, its complex crystal structure hampers any parametrization of the J-exchange parameter. The specific heat measurements exhibit a three-dimensional magnetic ordering ({lambda}-type) peak at 29.5 K. The magnetic structure of this phosphate shows ferromagnetic interactions inside the Ni{sub 2}O{sub 8} dimers, whereas the sublattice of Cu(II) ions presents antiferromagnetic couplings along the y-axis. The change of the sign in the magnetic unit-cell, due to the [1/2, 0, 1/2] propagation vector determines a purely antiferromagnetic structure. - Graphical abstract: Magnetic structure of CuNi2(PO4)2.

  6. Controllable synthesis and down-conversion properties of flower-like NaY(MoO{sub 4}){sub 2} microcrystals via polyvinylpyrrolidone-mediated

    SciTech Connect

    Lin, Han; Yan, Xiaohong; Wang, Xiangfu

    2013-08-15

    Double alkaline rare-earth molybdates NaY(MoO{sub 4}){sub 2} with multilayered flower-like architectures have been successfully synthesized via hydrothermal method in polyvinylpyrrolidone (PVP)-modified processes. The crystal structure and morphology of the obtained products were characterized by X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that reaction time and the amount of PVP have crucial influences on the morphology of the resulting novel microstructures. Under 450 nm excitation, Ho{sup 3+}/Yb{sup 3+} co-doped NaY(MoO{sub 4}){sub 2} samples exhibit 539 nm green emission and 960–1200 nm broadband near-infrared emission, corresponding to the characteristic lines of Ho{sup 3+} and Yb{sup 3+}, respectively. Moreover, increasing Yb{sup 3+} doping enhances the energy transfer efficiency from Ho{sup 3+} to Yb{sup 3+}. - Graphical abstract: Low and high-magnification SEM images demonstrate the perfect flower-like NaY(MoO{sub 4}){sub 2} prepared in the presence of PVP; Detailed TEM and HRTEM images further manifest the single-crystalline feature. Highlights: • NaY(MoO{sub 4}){sub 2} flower-like microstructures were synthesized by hydrothermal method using polyvinylpyrrolidone. • Polyvinylpyrrolidone induces the growth of the NaY(MoO{sub 4}){sub 2} to form multilayered architectures. • Flowerlike NaY(MoO{sub 4}){sub 2}: Ho{sup 3+}, Yb{sup 3+} phosphors were investigated as a downconversion layer candidate.

  7. Oxygen trapped by rare earth tetrahedral clusters in Nd4sub>FeOS6: Crystal structure, electronic structure, and magnetic properties

    SciTech Connect

    Lin, Qisheng; Taufour, Valentin; Zhang, Yuemei; Wood, Max; Drtina, Thomas; Bud’ko, Sergey L.; Canfield, Paul C.; Miller, Gordon J.

    2015-05-22

    Single crystals of Nd4sub>FeOS6 were grown from an Fe-S eutectic solution. Single crystal X-ray diffraction analysis revealed a Nd4sub>MnOSe6-type structure (P63mc, a = 9.2693(1) Å, c = 6.6650(1) Å, V = 495.94(1) Å3, Z = 2), featuring parallel chains of face-sharing [FeS6x1/2]4- trigonal antiprisms and interlinked [Nd4sub>OS3]4+ cubane-like clusters. Oxygen atoms were found to be trapped by Nd4 clusters in the [Nd4OS3]4+ chains. Structural differences among Nd4sub>MnOSe6-type Nd4sub>FeOS6 and the related La3CuSiS7- and Pr8CoGa3-type structures have been described. Magnetic susceptibility measurements on Nd4sub>FeOS6 suggested the dominance of antiferromagnetic interactions at low temperature, but no magnetic ordering down to 2 K was observed. Spin-polarized electronic structure calculations revealed magnetic frustration with dominant antiferromagnetic interactions.

  8. A sensitive and specific histopathologic prognostic marker for H3F3A K27M mutant pediatric glioblastomas.

    PubMed

    Venneti, Sriram; Santi, Mariarita; Felicella, Michelle Madden; Yarilin, Dmitry; Phillips, Joanna J; Sullivan, Lisa M; Martinez, Daniel; Perry, Arie; Lewis, Peter W; Thompson, Craig B; Judkins, Alexander R

    2014-11-01

    Pediatric glioblastomas (GBM) are highly aggressive and lethal tumors. Recent sequencing studies have shown that ~30 % of pediatric GBM and ~80 % of diffuse intrinsic pontine gliomas show K27M mutations in the H3F3A gene, a variant encoding histone H3.3. H3F3A K27M mutations lead to global reduction in H3K27me3. Our goal was to develop biomarkers for the histopathologic detection of these tumors. Therefore, we evaluated the utility of measuring H3K27me3 global reduction as a histopathologic and prognostic biomarker and tested an antibody directed specifically against the H3.3 K27M mutation in 290 samples. The study cohort included 203 pediatric (including 38 pediatric high-grade astrocytomas) and 38 adult brain tumors of various subtypes and grades and 49 non-neoplastic reactive brain tissues. Detection of H3.3 K27M by immunohistochemistry showed 100 % sensitivity and specificity and was superior to global reduction in H3K27me3 as a biomarker in diagnosing H3F3A K27M mutations. Moreover, cases that stained positive for H3.3 K27M showed a significantly poor prognosis compared to corresponding negative tumors. These results suggest that immunohistochemical detection of H3.3 K27M is a sensitive and specific surrogate for the H3F3A K27M mutation and defines a prognostically poor subset of pediatric GBM. PMID:25200322

  9. High power, diffraction limited picosecond oscillator based on Nd:GdVO4sub> bulk crystal with σ polarized in-band pumping.

    PubMed

    Lin, Hua; Guo, Jie; Gao, Peng; Yu, Hai; Liang, Xiaoyan

    2016-06-27

    We report on a high power passively mode-locked picosecond oscillator based on Nd:GdVO4sub> crystal with σ polarized in-band pumping. Thermal gradient and thermal aberration was greatly decreased with proposed configuration. Maximum output power of 37 W at 81 MHz repetition rate with 19.3 ps pulse duration was achieved directly from Nd:GdVO4sub> oscillator, corresponding to 51% optical efficiency. The oscillator maintained diffraction limited beam quality of M2 < 1.05 at different output coupling with pulse duration between 11.2 ps to 19.3 ps. PMID:27410558

  10. Photoluminescence and thermoluminescence properties of Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2} nanophosphor

    SciTech Connect

    Gupta, Palvi; Bedyal, A.K.; Kumar, Vinay; Khajuria, Y.; Lochab, S.P.; Pitale, S.S.; Ntwaeaborwa, O.M.; Swart, H.C.

    2014-12-15

    Energy level diagram of Tb{sup 3+} ion in the K{sub 3}Gd(PO{sub 4}){sub 2} host lattice. - Highlights: • First time, a detailed TL and PL study on undoped and Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2} nanophosphor. • Combustion method was employed to synthesize the Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2} nanophosphor. • Mechanism of excitation and emission in undoped and Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2} nanophosphor was given. - Abstract: Tb{sup 3+} doped nanoparticulate K{sub 3}Gd(PO{sub 4}){sub 2} phosphor was prepared by combustion method using urea as a fuel. The structure, optical and luminescent properties of the phosphor were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), and thermoluminescence (TL) spectroscopy. In undoped K{sub 3}Gd(PO{sub 4}){sub 2}, the excitation and emission peaks at 273 nm and 323 nm belongs to the {sup 8}S{sub 7/2} → {sup 6}I{sub J(J=7/2)} and {sup 6}P{sub J(J=7/2)} → {sup 8} S{sub 7/2} transitions of Gd{sup 3+} while green emission was observed in the Tb{sup 3+} doped K{sub 3}Gd(PO{sub 4}){sub 2}. TL study was carried out after exposing the samples to γ-radiations (0.1–5 kGy) in the K{sub 3}Gd(PO{sub 4}){sub 2}:Tb{sup 3+} (1.5 mol%). The calculated kinetic parameters were compared with different methods. The band gap of the phosphor was estimated as 5.80 eV. The green shade of the Tb{sup 3+} ion with the CIE coordinates (x, y) as (0.29, 0.54) was in good agreement with the well known green phosphors.

  11. Calculation of enthalpies of formation of compounds of the type M/sub 5/R(EO/sub 4/)/sub 4/

    SciTech Connect

    Kaganyuk, D.S.; Perepelitsa, A.P.

    1985-12-01

    Enthalpies of formation were determined for compounds of the M/sub 5/R(EO/sub 4/)/sub 4/ type, where M = Li, Na, K, Rb, Cs, Fr, Tl, Ag, Cu; R = the rare earth elements, y, Bi; and E = Mo, W. Values of ..delta..Hf/sup 0/, either experimentally determined or estimated by any quantum-chemical methods, are absent in the literature for these compounds. The obtained values of lambdaHf/sup 0/ for M/sub 5/R(EO/sub 4/)/sub 4/ are presented.

  12. Synthesis, crystal structure and spectroscopy properties of Na{sub 3} AZr(PO{sub 4}){sub 3} (A=Mg, Ni) and Li{sub 2.6}Na{sub 0.4}NiZr(PO{sub 4}){sub 3} phosphates

    SciTech Connect

    Chakir, M. . E-mail: fachakir@yahoo.fr; El Jazouli, A.; Waal, D. de

    2006-06-15

    Na{sub 3} AZr(PO{sub 4}){sub 3} (A=Mg, Ni) phosphates were prepared at 750 deg. C by coprecipitation route. Their crystal structures have been refined at room temperature from X-ray powder diffraction data using Rietveld method. Li{sub 2.6}Na{sub 0.4}NiZr(PO{sub 4}){sub 3} was synthesized through ion exchange from the sodium analog. These materials belong to the Nasicon-type structure. Raman spectra of Na{sub 3} AZr(PO{sub 4}){sub 3} (A=Mg, Ni) phosphates present broad peaks in favor of the statistical distribution in the sites around PO{sub 4} tetrahedra. Diffuse reflectance spectra indicate the presence of octahedrally coordinated Ni{sup 2+} ions. - Graphical abstract: Structure of Na{sub 3} AZr(PO{sub 4}){sub 3} (A=Mg, Ni) phosphates. Display Omitted.

  13. Magnetic structures of R5Ni2In4sub> and R11Ni4sub>In9 ( R = Tb and Ho): Strong hierarchy in the temperature dependence of the magnetic ordering in the multiple rare-earth sublattices

    SciTech Connect

    Ritter, C.; Provino, A.; Manfrinetti, P.; Pecharsky, V. K.; Gschneidner, Jr., K. A.; Dhar, S. K.

    2015-11-09

    In this study, the magnetic properties and magnetic structures of the R5Ni2In4sub> and the microfibrous R 11Ni4sub>In9 compounds with R = Tb and Ho have been examined using magnetization, heat capacity, and neutron diffraction data. Rare earth atoms occupy three and five symmetrically inequivalent rare earth sites in R5Ni2In4sub> and R 11Ni4sub>In9 compounds, respectively. As a result of the intra- and inter-magnetic sublattice interactions, the magnetic exchange interactions are different for various rare earth sites; this leads to a cascade of magnetic transitions with a strong hierarchy in the temperature dependence of the magnetic orderings.

  14. Phase transition and multicolor luminescence of Eu{sup 2+}/Mn{sup 2+}-activated Ca{sub 3}(PO{sub 4}){sub 2} phosphors

    SciTech Connect

    Li, Kai; Chen, Daqin; Xu, Ju; Zhang, Rui; Yu, Yunlong; Wang, Yuansheng

    2014-01-01

    Graphical abstract: We have synthesized Eu{sup 2+} doped and Eu{sup 2+}/Mn{sup 2+} co-doped Ca{sub 3}(PO{sub 4}){sub 2} phosphors. The emitting color varies from blue to green with increasing of Eu{sup 2+} content for the Eu{sup 2+}-doped phosphor, and the quantum yield of the 0.05Eu{sup 2+}: Ca{sub 2.95}(PO{sub 4}){sub 2} sample reaches 56.7%. Interestingly, Mn{sup 2+} co-doping into Eu{sup 2+}: Ca{sub 3}(PO{sub 4}){sub 2} leads to its phase transition from orthorhombic to rhombohedral, and subsequently generates tunable multi-color luminescence from green to red via Eu{sup 2+} → Mn{sup 2+} energy transfer. - Highlights: • A series of novel Eu{sup 2+}: Ca{sub 3}(PO{sub 4}){sub 2} phosphors were successfully synthesized. • Phase transition of Ca{sub 3}(PO{sub 4}){sub 2} from orthorhombic to rhombohedral occurred when Mn{sup 2+} ions were doped. • The phosphors exhibited tunable multi-color luminescence. • The quantum yield of 0.05Eu{sup 2+}: Ca{sub 2.95}(PO{sub 4}){sub 2} phosphor can reach 56.7%. • The analyses of phosphors were carried out by many measurements. - Abstract: Intense blue-green-emitting Eu{sup 2+}: Ca{sub 3}(PO{sub 4}){sub 2} and tunable multicolor-emitting Eu{sup 2+}/Mn{sup 2+}: Ca{sub 3}(PO{sub 4}){sub 2} phosphors are prepared via a solid-state reaction route. Eu{sup 2+}-doped orthorhombic Ca{sub 3}(PO{sub 4}){sub 2} phosphor exhibits a broad emission band in the wavelength range of 400–700 nm with a maximum quantum yield of 56.7%, and the emission peak red-shifts gradually from 479 to 520 nm with increase of Eu{sup 2+} doping content. Broad excitation spectrum (250–420 nm) of Eu{sup 2+}: Ca{sub 3}(PO{sub 4}){sub 2} matches well with the near-ultraviolet LED chip, indicating its potential applications as tri-color phosphors in white LEDs. Interestingly, Mn{sup 2+} co-doping into Eu{sup 2+}: Ca{sub 3}(PO{sub 4}){sub 2} leads to its phase transition from orthorhombic to rhombohedral, and subsequently generates tunable multi

  15. Expression of human eukaryotic initiation factor 3f oscillates with cell cycle in A549 cells and is essential for cell viability

    PubMed Central

    2010-01-01

    Background Transcriptional and postranslational regulation of the cell cycle has been widely studied. However, there is scarce knowledge concerning translational control of this process. Several mammalian eukaryotic initiation factors (eIFs) seem to be implicated in controlling cell proliferation. In this work, we investigated if the human eIF3f expression and function is cell cycle related. Results The human eIF3f expression has been found to be upregulated in growth-stimulated A549 cells and downregulated in G0. Western blot analysis and eIF3f promotor-luciferase fusions revealed that eIF3f expression peaks twice in the cell cycle: in the S and the M phases. Deregulation of eIF3f expression negatively affects cell viability and induces apoptosis. Conclusions The expression pattern of human eIF3f during the cell cycle confirms that this gene is cell division related. The fact that eIF3f expression peaks in two cell cycle phases raises the possibility that this gene may exert a differential function in the S and M phases. Our results strongly suggest that eIF3f is essential for cell proliferation. PMID:20462454

  16. CARCINOGENICITY OF BROMODICHLOROMETHANE ADMINISTERED IN DRINKING WATER TO THE MALE F344/N RAT AND B6C3F, MOUSE

    EPA Science Inventory

    CARCINOGENICITY OF BROMODICHLOROMETHANE ADMINISTERED IN DRINKING WATER TO THE MALE F344/N RAT AND B6C3F1 MOUSE.

    Bromodichloromethane (BDCM) has been shown to produce kidney and large bowel tumors in both male and female F344/N rats, kidney tumors in male B6C3F 1 mice and ...

  17. Trivalent aluminum ion conducting characteristics in Al{sub 2}(WO{sub 4}){sub 3} single crystals

    SciTech Connect

    Imanaka, N.; Tamura, S.; Hiraiwa, M.; Adachi, G.; Dabkowska, H.; Dabkowski, A.; Greedan, J.E.

    1998-09-01

    Single crystals of the trivalent Al{sup 3+} ion conductor Al{sub 2}(WO{sub 4}){sub 3} were grown by the Czochralski (CZ) method. The ionic conductivity in the a-, b-, and c-axis directions was determined and Al{sup 3+} ion conduction in the direction of the b-axis was concluded to be the most suitable pathway for ion migration in the tungstate grains. The ionic conductivities in the a- and c-axis directions were 0.3 and 10{sup {minus}2} times lower than the conductivity in the b-axis. Consistent with this observation, the lowest activation energy (E{sub a}) for Al{sup 3+} ion migration was obtained for the b-axis direction. The E{sub a} of the conductivity in the direction of the c-axis was almost comparable to that of the polycrystalline samples and the E{sub a} of the Al{sup 3+} ionic conduction in the grains of this material was explicitly verified to be controlled by the Al{sup 3+} ionic migration in the c-axis direction. The Al{sup 3+} ion conductivity of the polycrystalline sample was higher in the higher temperature region, indicating that the conductivity in the grain boundaries enhances the total Al{sup 3+} ion conductivity to a considerable extent. From the oxygen pressure dependencies of the electrical conductivity and the polarization behavior, the single crystals were demonstrated to be pure Al{sup 3+} ionic conductors showing an anisotropic ion conducting behavior.

  18. Highly Selective Colorimetric and Luminescence Response of a Square-Planar Platinum(II) Terpyridyl Complex to Aqueous TcO4sub>-

    SciTech Connect

    Chatterjee, Sayandev; Norton, Amie E.; Edwards, Matthew K.; Peterson, James M.; Taylor, Stephen D.; Bryan, Samuel A.; Andersen, Amity; Govind, Niranjan; Albrecht-Schmitt, Thomas E.; Connick, William; Levitskaia, Tatiana G.

    2015-10-08

    In an effort to address the need for a rapid, selective and economical detection technique for aqueous pertechnetate (TcO4sub>-) anion based on recognition at the molecular level, simple salts of transition metal complexes that undergo a distinct spectroscopic change upon exposure to aqueous anions were explored. The Pt(II) complex [Pt(tpy)Br]SbF6 (tpy=2,2';6',2"-terpyridine) undergoes a dramatic color change and intense luminescence response upon TcO4sub>- uptake due to concomitant enhancement of Pt•••Pt interactions. The spectroscopic response was highly selective and quantitative for aqueous TcO4sub>- among other competing anions. Complimentary Raman spectroscopy and microscopy techniques, structural determination and theoretical methods were employed to achieve molecular-level understanding of the mechanism of the response to aqueous TcO4sub>-.

  19. Low Temperature Propane Oxidation over Co3O4sub> based Nano-array Catalysts. Ni Dopant Effect, Reaction Mechanism and Structural Stability

    SciTech Connect

    Ren, Zheng; Wu, Zili; Gao, Puxian; Song, Wenqiao; Xiao, Wen; Guo, Yanbing; Ding, Jun; Suib, Steven L.; Gao, Pu-Xian

    2015-06-09

    Low temperature propane oxidation has been achieved by Co3O4sub>-based nano-array catalysts featuring low catalytic materials loading. The Ni doping into the Co3O4sub> lattice has led to enhanced reaction kinetics at low temperature by promoting the surface lattice oxygen activity. In situ DRIFTS investigation in tandem with isotopic oxygen exchange reveals that the propane oxidation proceeds via Mars-van Krevelen mechanism where surface lattice oxygen acts as the active site whereas O2 in the reaction feed does not directly participate in CO2 formation. The Ni doping promotes the formation of less stable carbonates on the surface to facilitate the CO2 desorption. The thermal stability of Ni doped Co3O4sub> decreases with increased Ni concentration while catalytic activity increases. A balance between enhanced activity and compromised thermal stability shall be considered in the Ni doped Co3O4sub> nano-array catalysts for low temperature hydrocarbon oxidation. This study provides useful and timely guidance for rational catalyst design toward low temperature catalytic oxidation.

  20. Ionic conductivity and the formation of cubic CaH{sub 2} in the LiBH{sub 4}–Ca(BH{sub 4}){sub 2} composite

    SciTech Connect

    Sveinbjörnsson, Dadi; Blanchard, Didier; Myrdal, Jon Steinar Gardarsson; Younesi, Reza; Viskinde, Rasmus; Riktor, Marit Dalseth; Norby, Poul; Vegge, Tejs

    2014-03-15

    LiBH{sub 4}–Ca(BH{sub 4}){sub 2} composites were prepared by ball milling. Their crystal structures and phase composition were investigated using synchrotron X-ray diffraction and Rietveld refinement, and their ionic conductivity was measured using impedance spectroscopy. The materials were found to form a physical mixture. The composites were composed of α-Ca(BH{sub 4}){sub 2}, γ-Ca(BH{sub 4}){sub 2} and orthorhombic LiBH{sub 4}, and the relative phase quantities of the Ca(BH{sub 4}){sub 2} polymorphs varied significantly with LiBH{sub 4} content. The formation of small amounts of orthorhombic CaH{sub 2} and cubic CaH{sub 2} in a CaF{sub 2}-like structure was observed upon heat treatment. Concurrent formation of elemental boron may also occur. The ionic conductivity of the composites was measured using impedance spectroscopy, and was found to be lower than that of ball milled LiBH{sub 4}. Electronic band structure calculations indicate that cubic CaH{sub 2} with hydrogen defects is electronically conducting. Its formation along with the possible precipitation of boron therefore has an effect on the measured conductivity of the LiBH{sub 4}–Ca(BH{sub 4}){sub 2} composites and may increase the risk of an internal short-circuit in the cells. -- Graphical abstract: An Arrhenius plot of the ionic conductivity of the LiBH{sub 4}–Ca(BH{sub 4}){sub 2} composites (red, blue, green). The ionic conductivity of ball milled (gray) and non-milled (black) LiBH{sub 4} is shown for comparison. The filled symbols are measured during heating runs and the empty symbols are measured during subsequent cooling runs. The conductivity of the composites is in all cases higher during cooling, most probably due to the formation of an electronically conducting layer containing defect-rich cubic CaH{sub 2}. Such layer formation could eventually lead to a short circuit in the cell and reveals a general issue of chemical stability that should be attended to in the development of solid

  1. A novel red long lasting phosphorescent (LLP) material {beta}-Zn{sub 3}(PO{sub 4}){sub 2}:Mn{sup 2+}, Sm{sup 3+}

    SciTech Connect

    Wang Jing; Su Qiang . E-mail: cessuq@zsu.edu.cn; Wang Shubin

    2005-04-20

    A novel red long lasting phosphorescent materials {beta}-Zn{sub 3}(PO{sub 4}){sub 2}:Mn{sup 2+},Sm{sup 3+} is firstly synthesized by high-temperature solid-state reaction. The influence of Sm{sup 3+} ions on luminescence and long lasting phosphorescence properties of Mn{sup 2+} in phosphor {beta}-Zn{sub 3}(PO{sub 4}){sub 2}:Mn{sup 2+},Sm{sup 3+} are systematically investigated. It is found that the red phosphorescence ({lambda} = 616 nm) performance of Mn{sup 2+} ion such as brightness and duration is largely improved when Sm{sup 3+} ion is co-doped into the matrix in which Mn{sup 2+} ion acts as luminescent center and Sm{sup 3+} ion plays an important role of electron trap. Thermoluminescence spectrums show that there exists one peak in {beta}-Zn{sub 3}(PO{sub 4}){sub 2}:Mn{sup 2+},Sm{sup 3+}, the depth of which is 0.33 eV, and that there are three peaks in {beta}-Zn{sub 3}(PO{sub 4}){sub 2}:Mn{sup 2+}, among which the depth of the lowest temperature peak in {beta}-Zn{sub 3}(PO{sub 4}){sub 2}:Mn{sup 2+} is 0.37 eV. Such differences in the trap depth result in the improvement of red long lasting phosphorescence of Mn{sup 2+} in present matrix.

  2. Syntheses, crystal structures and optical spectroscopy of Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O

    SciTech Connect

    Kazmierczak, Karolina; Hoeppe, Henning A.

    2011-05-15

    The lanthanide sulphate octahydrates Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) and the respective tetrahydrate Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O were obtained by evaporation of aqueous reaction mixtures of trivalent rare earth oxides and sulphuric acid at 300 K. Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) crystallise in space group C2/c (Z=4, a{sub Ho}=13.4421(4) A, b{sub Ho}=6.6745(2) A, c{sub Ho}=18.1642(5) A, {beta}{sub Ho}=102.006(1) A{sup 3} and a{sub Tm}=13.4118(14) A, b{sub Tm}=6.6402(6) A, c{sub Tm}=18.1040(16) A, {beta}{sub Tm}=101.980(8) A{sup 3}), Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O adopts space group P2{sub 1}/n (a=13.051(3) A, b=7.2047(14) A, c=13.316(3) A, {beta}=92.55(3) A{sup 3}). The vibrational and optical spectra of Ho{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O are also reported. -- Graphical abstract: In the lanthanide sulphate octahydrates the cations form slightly undulated layers. Between the layers are voids in which sulphate tetrahedra and water molecules are located. The holmium compound exhibits an Alexandrite effect. Display Omitted Highlights: {yields} Determination of the optimum conditions for the growth of single-crystals of Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O. {yields} Single-crystal structure elucidation of Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) including hydrogen bonds. {yields} Single-crystal structure determination of Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O including hydrogen bonds. {yields} UV-vis spectra of Ho{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O recorded and interpreted: Assignation of bands and clarification of the Alexandrite effect of the Ho compound. {yields} IR and Raman spectra of Ln{sub 2}(SO{sub 4}){sub 3}.8H{sub 2}O (Ln=Ho, Tm) and Pr{sub 2}(SO{sub 4}){sub 3}.4H{sub 2}O recorded and interpreted.

  3. Topological amplitudes in D decays to two pseudoscalars: A global analysis with linear S U (3 )F breaking

    NASA Astrophysics Data System (ADS)

    Müller, Sarah; Nierste, Ulrich; Schacht, Stefan

    2015-07-01

    We study decays of D0, D+, and Ds+ mesons into two pseudoscalar mesons by expressing the decay amplitudes in terms of topological amplitudes. Including consistently S U (3 )F breaking to linear order, we show how the topological-amplitude decomposition can be mapped onto the standard expansion using reduced amplitudes characterized by S U (3 ) representations. The tree and annihilation amplitudes can be calculated in factorization up to corrections which are quadratic in the color-counting parameter 1 /Nc. We find new sum rules connecting D+→KSK+ , Ds+→KSπ+, and D+→K+π0, which test the quality of the 1 /Nc expansion. Subsequently, we determine the topological amplitudes in a global fit to the data, taking the statistical correlations among the various measurements into account. We carry out likelihood ratio tests in order to quantify the role of specific topological contributions. While the S U (3 )F limit is excluded with a significance of more than 5 standard deviations, a good fit (with Δ χ2<1 ) can be obtained with less than 28% of S U (3 )F breaking in the decay amplitudes. The magnitude of the penguin amplitude Pbreak, which probes the Glashow-Iliopoulos-Maiani mechanism, is consistent with zero; the hypothesis Pbreak=0 is rejected with a significance of just 0.7 σ . We obtain the Standard-Model correlation between B (D0→KLπ0) and B (D0→KSπ0), which probes doubly Cabibbo-suppressed amplitudes, and find that B (D0→KLπ0)

  4. Growth hormone promoted tyrosyl phosphorylation of growth hormone receptors in murine 3T3-F442A fibroblasts and adipocytes

    SciTech Connect

    Foster, C.M.; Shafer, J.A.; Rozsa, F.W.; Wang, X.; Lewis, S.D.; Renken, D.A.; Natale, J.E.; Schwartz, J.; Carter-Su, C.

    1988-01-12

    Because many growth factor receptors are ligand-activated tyrosine protein kinases, the possibility that growth hormone (GH), a hormone implicated in human growth, promotes tyrosyl phosphorylation of its receptor was investigated. /sup 125/I-Labeled human GH was covalently cross-linked to receptors in intact 3T3-F442A fibroblasts, a cell line which differentiates into adipocytes in response to GH. The cross-linked cells were solubilized and passed over a column of phosphotyrosyl binding antibody immobilized on protein A-Sepharose. Immunoadsorbed proteins were eluted with a hapten (p-nitrophenyl phosphate) and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. The eluate from the antibody column contained in M/sub r/ 134,000 /sup 125/I-GH-receptor complex. A similar result was obtained when the adipocyte form of 3T3-F442A cells was used in place of fibroblast form. O-Phosphotyrosine prevented /sup 125/I-GH-receptor complexes from binding to the antibody column, whereas O-phosphoserine and O-phosphothreonine did not. In studies of GH-promoted phosphorylation in 3T3-F442A fibroblasts labeled metabolically with (/sup 32/P)P/sub i/, GH was shown to stimulate formation of a /sup 32/P-labeled protein which bound to immobilized phosphotyrosyl binding antibodies. The molecular weight of 114,000 obtained for this protein is similar to that expected for non-cross-linked GH receptor. These observations provide strong evidence that binding of GH to its receptor stimulates phosphorylation of tyrosyl residues in the GH receptor.

  5. Development of doxorubicin-induced chronic cardiotoxicity in the B6C3F{sub 1} mouse model

    SciTech Connect

    Desai, Varsha G.; Herman, Eugene H.; Moland, Carrie L.; Branham, William S.; Lewis, Sherry M.; Davis, Kelly J.; George, Nysia I.; Lee, Taewon; Kerr, Susan; Fuscoe, James C.

    2013-01-01

    Serum levels of cardiac troponins serve as biomarkers of myocardial injury. However, troponins are released into the serum only after damage to cardiac tissue has occurred. Here, we report development of a mouse model of doxorubicin (DOX)-induced chronic cardiotoxicity to aid in the identification of predictive biomarkers of early events of cardiac tissue injury. Male B6C3F{sub 1} mice were administered intravenous DOX at 3 mg/kg body weight, or an equivalent volume of saline, once a week for 4, 6, 8, 10, 12, and 14 weeks, resulting in cumulative DOX doses of 12, 18, 24, 30, 36, and 42 mg/kg, respectively. Mice were sacrificed a week following the last dose. A significant reduction in body weight gain was observed in mice following exposure to a weekly DOX dose for 1 week and longer compared to saline-treated controls. DOX treatment also resulted in declines in red blood cell count, hemoglobin level, and hematocrit compared to saline-treated controls after the 2nd weekly dose until the 8th and 9th doses, followed by a modest recovery. All DOX-treated mice had significant elevations in cardiac troponin T concentrations in plasma compared to saline-treated controls, indicating cardiac tissue injury. Also, a dose-related increase in the severity of cardiac lesions was seen in mice exposed to 24 mg/kg DOX and higher cumulative doses. Mice treated with cumulative DOX doses of 30 mg/kg and higher showed a significant decline in heart rate, suggesting drug-induced cardiac dysfunction. Altogether, these findings demonstrate the development of DOX-induced chronic cardiotoxicity in B6C3F{sub 1} mice. -- Highlights: ► 24 mg/kg was a cumulative cardiotoxic dose of doxorubicin in male B6C3F{sub 1} mice. ► Doxorubicin-induced hematological toxicity was in association with splenomegaly. ► Doxorubicin induced severe testicular toxicity in B6C3F{sub 1} male mice.

  6. Absolute Line Intensities in the ν 3Band of 12CH 3F by Diode-Laser Spectroscopy

    NASA Astrophysics Data System (ADS)

    Lepère, Muriel; Blanquet, Ghislain; Walrand, Jacques

    1996-06-01

    Infrared absolute line intensities of the ν 3band of 12CH 3F have been measured around 9.5 μm using a diode-laser spectrometer. These line strengths were obtained from the equivalent width method and, for a few lines, by fitting a Rautian profile to the measured shape of the lines. From these results, we have deduced the vibrational bandstrength ( Sv0= 379.2 ± 5.9 cm -2·atm -1at 296 K) and the first Herman-Wallis factor (α = 0.35 × 10 -3± 0.10 × 10 -3).

  7. Structural study and physical properties of a new phosphate KCuFe(PO{sub 4}){sub 2}

    SciTech Connect

    Badri, Abdessalem; Hidouri, Mourad; Lopez, Maria Luisa; Pico, Carlos; Wattiaux, Alain; Ben Amara, Mongi

    2011-04-15

    Single crystals of a new phosphate KCuFe(PO{sub 4}){sub 2} have been prepared by the flux method and its structural and physical properties have been investigated. This compound crystallizes in the monoclinic system with the space group P2{sub 1}/n and its parameters are: a=7.958(3) A, b=9.931(2) A, c=9.039(2) A, {beta}=115.59(3){sup o} and Z=4. Its structure consists of FeO{sub 6} octahedra sharing corners with Cu{sub 2}O{sub 8} units of edge-sharing CuO{sub 5} polyhedra to form undulating chains extending infinitely along the b-axis. These chains are connected by the phosphate tetrahedra giving rise to a 3D framework with six-sided tunnels parallel to the [101] direction, where the K{sup +} ions are located. The Moessbauer spectroscopy results confirm the exclusive presence of octahedral Fe{sup 3+} ions. The magnetic measurements show the compound to be antiferromagnetic with C{sub m}=5.71 emu K/mol and {theta}=-156.5 K. The derived experimental effective moment {mu}{sub ex}=6.76{mu}{sub B} is somewhat higher than the theoretical one of {mu}{sub th}=6.16{mu}{sub B}, calculated taking only into account the spin contribution for Fe{sup 3+} and Cu{sup 2+} cations. Electrical measurements allow us to obtain the activation energy (1.22 eV) and the conductivity measurements suggest that the charge carriers through the structure are the potassium cations. -- Graphical abstract: A projection along the [101] direction of the structure showing the six-edged tunnels, occupied by the K{sup +} ions. Display Omitted Highlights: {yields} The reported structure is of a new type. {yields} The structural model is supported by a Moessbauer spectroscopy study. {yields} The magnetic susceptibility results are reported. {yields} The electrical properties are discussed.

  8. Combustion synthesized nanocrystalline Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C cathode for lithium-ion batteries

    SciTech Connect

    Nathiya, K.; Bhuvaneswari, D.; Gangulibabu; Kalaiselvi, N.

    2012-12-15

    Graphical abstract: Nanocrystalline Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C compound has been synthesized using a novel corn assisted combustion (CAC) method, wherein the composite prepared at 850 °C is found to exhibit superior physical and electrochemical properties than the one synthesized at 800 °C (Fig. 1). Despite the charge disproportionation of V{sup 4+} and a possible solid solution behavior of Li{sub 3}V{sub 2}(PO{sub 4}){sub 3} cathode upon insertion and de-insertion of Li{sup +} ions, the structural stability of the same is appreciable, even with the extraction of third lithium at 4.6 V (Fig. 2). An appreciable specific capacity of 174 mAh g{sup −1} with an excellent columbic efficiency (99%) and better capacity retention upon high rate applications have been exhibited by Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C cathode, thus demonstrating the feasibility of CAC method in preparing the title compound to best suit with the needs of lithium battery applications. Display Omitted Highlights: ► Novel corn assisted combustion method has been used to synthesize Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C. ► Corn is a cheap and eco benign combustible fuel to facilitate CAC synthesis. ► Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C exhibits an appreciable specific capacity of 174 mAh g{sup −1} (C/10 rate). ► Currently observed columbic efficiency of 99% is better than the reported behavior. ► Suitability of Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C cathode up to 10C rate is demonstrated. -- Abstract: Nanocrystalline Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C composite synthesized using a novel corn assisted combustion method at 850 °C exhibits superior physical and electrochemical properties than the one synthesized at 800 °C. Despite the charge disproportionation of V{sup 4+} and a possible solid solution behavior of Li{sub 3}V{sub 2}(PO{sub 4}){sub 3} cathode upon insertion and extraction of Li{sup +} ions, the structural stability of the same is appreciable, even with

  9. Structural, energetic and thermodynamic analyses of Ca(BH{sub 4}){sub 2}{center_dot}2NH{sub 3} from first principles calculations

    SciTech Connect

    Yuan Pengfei; Wang Fei; Sun Qiang; Jia Yu; Guo Zhengxiao

    2012-01-15

    Ca(BH{sub 4}){sub 2}{center_dot}2NH{sub 3} is a relatively new compound with potential application in hydrogen storage. Here the fundamental properties of the compound, such as electronic structure, energetic and thermodynamic properties, were comprehensively studied using first-principles calculations. Results from electronic density of states (DOS) and electron localization function (ELF) indicate the covalent bond nature of the N-H bond and the B-H bond. Charge density analyses show weak ionic interactions between the Ca atom and the NH{sub 3} complexes or the (BH{sub 4}){sup -} complexes. The calculated vibration frequencies of B-H and N-H are in good agreement with other theoretical and experimental results. Furthermore, we calculated the reaction enthalpy and reaction Gibbs free energy at a range of temperature 0-700 K. Our results are in good agreement with experimental results in literature. Possible reaction mechanism of the decomposition reaction is proposed. - Graphical Abstract: The crystal structure of this compound and the calculated decomposition reaction free energy for two different reactions: Reac(2):Ca(BH{sub 4}){sub 2} Dot-Operator 2NH{sub 3} Long-Rightwards-Arrow {sup 162 Degree-Sign C}Ca(BH{sub 4}){sub 2} Dot-Operator NH{sub 3}+NH{sub 3} Long-Rightwards-Arrow {sup 230 Degree-Sign C}Ca(BH{sub 4}){sub 2}+2NH{sub 3} Reac(3):Ca(BH{sub 4}){sub 2} Dot-Operator 2NH{sub 3} Long-Rightwards-Arrow {sup 190 Degree-Sign C}1/4Ca(BH{sub 4}){sub 2}+1/4Ca{sub 3}(BN{sub 2}){sub 2}+BN+6H{sub 2}. Highlights: Black-Right-Pointing-Pointer Crystal structure of this compound was studied in detail. Black-Right-Pointing-Pointer Electronic properties were calculated for the first time. Black-Right-Pointing-Pointer Phonon density of states and reaction free energy at different temperatures were first calculated. Black-Right-Pointing-Pointer Possible decomposition mechanism was presented.

  10. Comparison of Renal Amyloid and Hyaline Glomerulopathy in B6C3F1 Mice: An NTP Retrospective Study.

    PubMed

    Hoane, Jessica S; Johnson, Crystal L; Morrison, James P; Elmore, Susan A

    2016-07-01

    Due to potential misdiagnosis of hyaline glomerulopathy (HG) for amyloidosis, a retrospective study of B6C3F1 mice from the National Toxicology Program (NTP) archives was undertaken to determine whether HG had occurred in prior NTP studies and, if so, whether these 2 glomerular lesions could be routinely discriminated. Kidney slides from 7 amyloid-positive control mice, 2 HG-positive control mice, 3 normal or negative control mice, and 41 potential HG mice (with renal-only deposits previously diagnosed as amyloid) were evaluated using hematoxylin and eosin (H&E), periodic acid Schiff (PAS), Congo red (CR), and Masson's trichrome (MT) stains. Utilizing these techniques, HG was reliably distinguished from amyloidosis. All 41 potential HG mice had glomerular deposits histochemically inconsistent with amyloid; the deposits were PAS positive and CR negative. Four of the 41 mice were selected for transmission electron microscopy of the glomerular deposits; ultrastructurally, the deposits in these animals were consistent with HG and not amyloid. Our findings indicate that HG is a spontaneous lesion in B6C3F1 mice of low occurrence, is commonly misdiagnosed as amyloidosis, and is more likely than amyloid to cause glomerular deposits in mice without evidence of deposits in other tissues. Also, HG can be distinguished from amyloid on H&E evaluation; however, the distinction is improved with use of PAS or CR staining and/or ultraviolet evaluation. PMID:27000376

  11. Elevated oxidative stress in skin of B6C3F1 mice affects dermal exposure to metal working fluid.

    PubMed

    Shvedova, A A; Kisin, E; Kisin, J; Castranova, V; Kommineni, C

    2000-09-01

    Metal working fluids (MWFs) are widely used in industry for metal cutting, drilling, shaping, lubricating, and milling. Potential for dermal exposure to MWFs exists for a large number of men and women via aerosols and splashing during the machining operations. It has been reported earlier that occupational exposure to MWFs causes allergic and irritant contact dermatitis. Previously, we showed that dermal exposure of female and male B6C3F1 mice to 5% MWFs for 3 months resulted in accumulation of mast cells and elevation of histamine in the skin. Topical exposure to MWF also resulted in elevated oxidative stress in the liver of both sexes and the testes in males. The goal of this study was to evaluate the interaction between oxidative stress in the skin and topical application of MWF. Oxidative stress in skin ofB6C3F1 mice of both sexes was generated by intradermal injection ofthe hydrogen peroxide (H2O2) -producing enzyme, glucose oxidase with polyethylene glycol (GOD+PEG). In mice given GOD+PEG, topical treatment with MWF (200 microl, 30%, for 1, 3, or 7 days) resulted in a mixed inflammatory cell response, accumulation of peroxidative products, and reduction of GSH content in the skin. Such changes were not observed with MWF treatment alone. These data indicate that oxidative stress can enhance dermal inflammation caused by occupational exposure to MWF. PMID:11693944

  12. Neuropilin-2/Semaphorin-3F-mediated repulsion promotes inner hair cell innervation by spiral ganglion neurons

    PubMed Central

    Coate, Thomas M; Spita, Nathalie A; Zhang, Kaidi D; Isgrig, Kevin T; Kelley, Matthew W

    2015-01-01

    Auditory function is dependent on the formation of specific innervation patterns between mechanosensory hair cells (HCs) and afferent spiral ganglion neurons (SGNs). In particular, type I SGNs must precisely connect with inner HCs (IHCs) while avoiding connections with nearby outer HCs (OHCs). The factors that mediate these patterning events are largely unknown. Using sparse-labeling and time-lapse imaging, we visualized for the first time the behaviors of developing SGNs including active retraction of processes from OHCs, suggesting that some type I SGNs contact OHCs before forming synapses with IHCs. In addition, we demonstrate that expression of Semaphorin-3F in the OHC region inhibits type I SGN process extension by activating Neuropilin-2 receptors expressed on SGNs. These results suggest a model in which cochlear innervation patterns by type I SGNs are determined, at least in part, through a Semaphorin-3F-mediated inhibitory signal that impedes processes from extending beyond the IHC region. DOI: http://dx.doi.org/10.7554/eLife.07830.001 PMID:26302206

  13. Structure symmetry determination and magnetic evolution in Sr2Ir1–xRhxO4sub>

    SciTech Connect

    Ye, Feng; Wang, Xiaoping; Hoffmann, Christina; Wang, Jinchen; Chi, Songxue; Matsuda, Masaaki; Chakoumakos, Bryan C.; Fernandez-Baca, Jaime A.; Cao, Gang

    2015-11-23

    We use single-crystal neutron diffraction to determine the crystal structure symmetry and to study the magnetic evolution in the rhodium doped iridates Sr2Ir1–xRhxO4sub> (0 ≤ x ≤ 0.16). Throughout this doping range, the crystal structure retains a tetragonal symmetry (space group I4<sub>1/a) with two distinct magnetic Ir sites in the unit cell forming staggered IrO6 rotation. Upon Rh doping, the magnetic order is suppressed and the magnetic moment of Ir4+ is reduced from 0.21 μB/Ir for x = 0 to 0.18 μB/Ir for x = 0.12. As a result, the magnetic structure at x = 0.12 is different from that of the parent compound while the moments remain in the basal plane.

  14. Neutron scattering studies of the H2a-H2b and (H3-H4)/sub 2/ histone complexes

    SciTech Connect

    Carlson, R.D.

    1982-01-01

    Neutron scattering experiments have shown that both the (H3-H4)/sub 2/ and H2a-H2b histone complexes are quite asymmetric in solution. The (H3-H4)/sub 2/ tetramer is an oblate or flattened structure, with a radius of gyration almost as large as that of the core octamer. If the tetramer is primarily globular, it must have an axial ratio of about 1:5. It is more likely, however, that this asymmetry results in part from N-terminal arms that extend outward approximately within the major plane of the particle. If this is the case, less asymmetric models for the globular part of the tetramer, including a dislocated disk, can be made consistent with the scattering data. The H2a-H2b dimer, on the other hand, is an elongated structure. 48 references, 12 figures, 1 table.

  15. Stabilization of heterogeneous silicon lasers using Pound-Drever-Hall locking to Si3N4sub> ring resonators.

    PubMed

    Spencer, Daryl T; Davenport, Michael L; Komljenovic, Tin; Srinivasan, Sudharsanan; Bowers, John E

    2016-06-13

    Recent results on heterogeneous Si/III-V lasers and ultra-high Q Si3N4sub> resonators are implemented in a Pound-Drever-Hall frequency stabilization system to yield narrow linewidth characteristics for a stable on-chip laser reference. The high frequency filtering is performed with Si resonant mirrors in the laser cavity. To suppress close in noise and frequency walk off, the laser is locked to an ultra-high Q Si3N4sub> resonator with a 30 million quality factor. The laser shows high frequency noise levels of 60 × 103 Hz2/Hz corresponding to 160 kHz linewidth, and the low frequency noise is suppressed 33 dB to 103 Hz2/Hz with the PDH system. PMID:27410367

  16. Structurally induced magnetization in a La2/3Sr4/3MnO4sub> superlattice

    SciTech Connect

    Shah, Amish B.; Nelson-Cheeseman, Brittany B.; Subramanian, Ganesh; Bhattacharya, Anand; Spence, John C.H.

    2012-03-16

    A structural transition has been observed in a digital superlattice of La2/3Sr4/3MnO4sub>, which is correlated to a magnetization enhancement upon cooling the sample. The artificial superlattices were grown layer-by-layer using ozone-assisted molecular beam epitaxy (MBE). Electron diffraction experiments show a phase transition below 150K in nanopatches of the superlattice, which coincides with an enhanced magnetization starting below 110K. Furthermore, atomic scale electron energy loss spectroscopy (EELS) shows changes in the Mn L2,3 and O K edges, which are related to valence, strain, and the atomic coordination within nanopatches. Atomic resolution image and EELS showing variations of oxygen and lanthanum signature edges in a La2/3Sr4/3MnO4sub> supperlattice.

  17. Theoretical Assessment on the Phase Transformation Kinetic Pathways of Multi-component Ti Alloys: Application to Ti-6Al-4sub>V

    SciTech Connect

    Ji, Yanzhou; Heo, Tae Wook; Zhang, Fan; Chen, Long-Qing

    2015-12-21

    Here we present our theoretical assessment of the kinetic pathways during phase transformations of multi-component Ti alloys. Employing the graphical thermodynamic approach and an integrated free energy function based on the realistic thermodynamic database and assuming that a displacive structural transformation occurs much faster than long-range diffusional processes, we analyze the phase stabilities of Ti-6Al-4sub>V (Ti-6wt.%Al-4sub>wt.%V). Our systematic analyses predict a variety of possible kinetic pathways for β to (α + β) transformations leading to different types of microstructures under various heat treatment conditions. In addition, the possibility of unconventional kinetic pathways is discussed. Lastly, we also briefly discuss the application of our approach to general multicomponent/multiphase alloy systems.

  18. Magnetic properties of (FeIn{sub 2}S{sub 4}){sub 1-x}(In{sub 2}S{sub 3}){sub x} alloy single crystals

    SciTech Connect

    Bodnar, I. V. Novikova, M. A.; Trukhanov, S. V.

    2013-05-15

    (FeIn{sub 2}S{sub 4}){sub 1-x}(In{sub 2}S{sub 3}){sub x} alloy single crystals are grown by oriented crystallization in the entire range of component concentrations. For the single crystals, studies of the magnetic properties are carried out in the temperature range 4-300 K and the magnetic-field range 0-14 T. It is established that almost all of the alloys are paramagnetic materials at temperatures down to the lowest achievable temperatures ({approx}4 K). It is shown that the ground magnetic phase state of the alloys is the spin-glass state with the freezing temperature steadily increasing with increasing Fe{sup 2+} cation content. The most probable causes and mechanism of formation of the magnetic state of the (FeIn{sub 2}S{sub 4}){sub 1-x}(In{sub 2}S{sub 3}){sub x} crystals are discussed.

  19. Electric-field-induced linear birefringence in TmAl3(BO3)4sub>.

    PubMed

    Pashchenko, M I; Bedarev, V A; Merenkov, D N; Gnatchenko, S L; Bezmaternykh, L N; Sukhachev, A L; Temerov, V L

    2016-04-20

    The linear birefringence induced by the electric field was first detected in a TmAl3(BO3)4sub> single crystal. The electric field dependence of the birefringence was investigated. The estimation of the electro-optical coefficient of the material gives ≈1.5×10-10  cm/V for a wavelength 632.8 nm. PMID:27140114

  20. Phase-matching directions and refined Sellmeier equations of the monoclinic acentric crystal BaGa4sub>Se7.

    PubMed

    Boursier, Elodie; Segonds, Patricia; Ménaert, Bertrand; Badikov, Valeriy; Panyutin, Vladimir; Badikov, Dmitrii; Petrov, Valentin; Boulanger, Benoît

    2016-06-15

    We directly measured the phase-matching directions of second-harmonic and difference frequency generation in the principal planes of the biaxial BaGa4sub>Se7 (BGSe) crystal using the sphere method. The simultaneous fit of the data allowed us to refine the Sellmeier equations of the three principal refractive indices of BGSe, and to calculate the tuning curves for infrared optical parametric generation. PMID:27304275

  1. Multi-wavelength Yb:YAG/Nd3+:YVO4sub> continuous-wave microchip Raman laser.

    PubMed

    Wang, Xiao-Lei; Dong, Jun; Wang, Xiao-Jie; Xu, Jie; Ueda, Ken-Ichi; Kaminskii, Alexander A

    2016-08-01

    Multi-wavelength continuous-wave (CW) Raman lasers in a laser diode pumped Yb:YAG/Nd3+:YVO4sub> microchip Raman laser have been demonstrated for the first time to our best knowledge. The multi-wavelength laser of the first Stokes radiation around 1.08 μm has been achieved with a Raman shift of 261  cm-1 for a-cut Nd:YVO4sub> crystal corresponding to the fundamental wavelength at 1.05 μm. Multi-wavelength laser operation simultaneously around 1.05 and 1.08 μm has been achieved under the incident pump power between 1.5 and 1.7 W. Multi-wavelength Raman laser with frequency separation of 1 THz around 1.08 μm has been obtained when the incident pump power is higher than 1.7 W. The maximum Raman laser output power of 260 mW at 1.08 μm is obtained and the corresponding optical-to-optical conversion efficiency is 4.2%. Elliptically polarized fundamental laser and linearly polarized Raman laser were observed in an Yb:YAG/Nd:YVO4sub> CW microchip Raman laser. The experimental results of linearly polarized, multi-wavelength Yb:YAG/Nd:YVO4sub> CW microchip Raman laser with adjustable frequency separation provide a novel approach for developing potential compact laser sources for Terahertz generation. PMID:27472618

  2. Multiple-site carcinogenicity of benzene in Fischer 344 rats and B6C3F1 mice.

    PubMed Central

    Huff, J E; Haseman, J K; DeMarini, D M; Eustis, S; Maronpot, R R; Peters, A C; Persing, R L; Chrisp, C E; Jacobs, A C

    1989-01-01

    Toxicology and carcinogenesis studies of benzene (CAS No. 71-43-2; greater than 99.7% pure) were conducted in groups of 60 F344/N rats and 60 B6C3F1 mice of each sex for each of three exposure doses and vehicle controls. These composite studies on benzene were designed and conducted because of large production volume and widespread human exposure, because of the epidemiologic association with leukemia, and because previous experiments were considered inadequate or inconclusive for determining carcinogenicity in laboratory animals. Using the results from 17-week studies, doses for the 2-year studies were selected based on clinical observations (tremors in higher dosed mice), on clinical pathologic findings (lymphoid depletion in rats and leukopenia in mice), and on body weight effects. Doses of 0, 50, 100, or 200 mg/kg body weight benzene in corn oil were administered by gavage to male rats, 5 days per week, for 103 weeks. Doses of 0, 25, 50, or 100 mg/kg benzene in corn oil were administered by gavage to female rats and to male and female mice for 103 weeks. Ten animals in each of the 16 groups were killed at 12 months, and necropsies were performed. Hematologic profiles were performed at 3-month intervals. For the 2-year studies, mean body weights of the top dose groups of male rats and of both sexes of mice were lower than those of the controls. Survivals of the top dose group of rats and mice of each sex were reduced; however, at week 92 for rats and week 91 for mice, survival was greater than 60% in all groups; most of the dosed animals that died before week 103 had neoplasia. Compound-related nonneoplastic or neoplastic effects on the hematopoietic system, Zymbal gland, forestomach, and adrenal gland were found both for rats and mice. Further, the oral cavity was affected in rats, and the lung, liver, Harderian gland, preputial gland, ovary, and mammary gland were affected in mice. Under the conditions of these 2-year gavage studies, there was clear evidence

  3. Genistein modulation of streptozotocin diabetes in male B6C3F1 mice can be induced by diet

    SciTech Connect

    Guo, Tai L.; Wang, Yunbiao; Xiong, Tao; Ling, Xiao; Zheng, Jianfeng

    2014-11-01

    Diet and phytoestrogens affect the development and progression of diabetes. The objective of the present study was to determine if oral exposure to phytoestrogen genistein (GE) by gavage changed blood glucose levels (BGL) through immunomodulation in streptozotocin (STZ)-induced diabetic male B6C3F1 mice fed with three different diets. These three diets were: NTP-2000 diet (NTP), soy- and alfalfa-free 5K96 diet (SOF) and high fat diet (HFD) with 60% of kcal from fat, primarily rendered fat of swine. The dosing regimen for STZ consisted of three 100 mg/kg doses (i.p.): the first dose was administered at approximately 2 weeks following the initiation of daily GE (20 mg/kg) gavage, and the second dose was on day 19 following the first dose, and the third dose was on day 57 following the first dose. In mice on the NTP diet, GE treatment decreased BGL with statistical significances observed on days 33 and 82 following the first STZ injection. In mice fed the HFD diet, GE treatment produced a significant decrease and a significant increase in BGL on days 15 and 89 following the first STZ injection, respectively. In mice fed the SOF diet, GE treatment had no significant effects on BGL. Although GE treatment affected phenotypic distributions of both splenocytes (T cells, B cells, natural killer cells and neutrophils) and thymocytes (CD4/CD8 and CD44/CD25), and their mitochondrial transmembrane potential and generation of reactive oxygen species, indicators of cell death (possibly apoptosis), GE modulation of neutrophils was more consistent with its diabetogenic or anti-diabetic potentials. The differential effects of GE on BGL in male B6C3F1 mice fed with three different diets with varied phytoestrogen contents suggest that the estrogenic properties of this compound may contribute to its modulation of diabetes. - Highlights: • Diets affected streptozotocin-induced diabetes in male B6C3F1 mice. • Genistein modulation of streptozotocin diabetes can be induced by diet.

  4. New insulating antiferromagnetic quaternary iridates MLa10Ir4sub>O24 (M=Sr, Ba)

    SciTech Connect

    Zhao, Qingbiao; Han, Fei; Stoumpos, Constantinos C.; Han, Tian -Heng; Li, Hao; Mitchell, J. F.

    2015-07-01

    Recently, oxides of Ir4+ have received renewed attention in the condensed matter physics community, as it has been reported that certain iridates have a strongly spin-orbital coupled (SOC) electronic state, Jeff = ½, that defines the electronic and magnetic properties. The canonical example is the Ruddlesden-Popper compound Sr2IrO4sub>, which has been suggested as a potential route to a new class of high temperature superconductor due to the formal analogy between Jeff = ½ and the S = ½ state of the cuprate superconductors. The quest for other iridium oxides that present tests of the underlying SOC physics is underway. In this spirit, here we report the synthesis and physical properties of two new quaternary tetravalent iridates, MLa10Ir4sub>O24 (M = Sr, Ba). The crystal structure of both compounds features isolated IrO6 octahedra in which the electronic configuration of Ir is d5. As a result, both compounds order antiferromagnetically despite the lack of obvious superexchange pathways, and resistivity measurement shows that SrLa10Ir4sub>O24 is an insulator.

  5. Correlation of anisotropy and directional conduction in β-Li3PS4sub> fast Li+ conductor

    SciTech Connect

    Chen, Yan; Cai, Lu; Liu, Zengcai; dela Cruz, Clarina R.; Liang, Chengdu; An, Ke

    2015-07-06

    Our letter reports the correlation of anisotropy and directional conduction in the fast Li+ conductor β-Li3PS4sub>, one of the low-symmetry crystalline electrolyte candidates. The material has both high conductivity and good stability that serves well for the large-scale energy storage applications of all-solid-state lithium ion batteries. The anisotropic physical properties, demonstrated here by the thermal expansion coefficients, are crucial for compatibility in the solid-state system and battery performance. Neutron and X-ray powder diffraction measurements were done to determine the crystal structure and thermal stability. Moreover, the crystallographic b-axis was revealed as a fast expansion direction, while negligible thermal expansion was observed along the a-axis around the battery operating temperatures. The anisotropic behavior has its structural origin from the Li+ conduction channels with incomplete Li occupancy and a flexible connection of LiS4sub> and PS4sub> tetrahedra within the framework. This indicates a strong correlation in the direction of the ionic transport in the low-symmetry Li+ conductor.

  6. Synthesis, crystal growth, structural and magnetic characterization of NH4sub>MCl2(HCOO), M=(Fe, Co, Ni)

    SciTech Connect

    Greenfield, Joshua T.; Ovidiu Garlea, V.; Kamali, Saeed; Chen, Michael; Kovnir, Kirill

    2015-09-24

    In this paper, an ambient-pressure solution route and an improved solvothermal synthetic method have been developed to produce polycrystalline powders and large single crystals of NH4sub>MCl2(HCOO) (M=Fe, Co, Ni). The magnetic structure of the 1D linear chain compound NH4sub>FeCl2(HCOO) has been determined by low-temperature neutron powder diffraction, revealing ferromagnetic intra-chain interactions and antiferromagnetic inter-chain interactions. Finally, the newly-reported Co and Ni analogs are isostructural with NH4sub>FeCl2(HCOO), but there are significant differences in the magnetic properties of each compound; the Ni analog behaves similarly to the Fe compound but with stronger magnetic coupling, exhibiting antiferromagnetic ordering (TN=8.5 K) and a broad metamagnetic transition between 2 and 5 T, while the Co analog does not order magnetically above 2 K, despite strong antiferromagnetic nearest-neighbor interactions.

  7. Organogold oligomers: Exploiting iClick and aurophilic cluster formation to prepare solution stable Au4sub> repeating units

    SciTech Connect

    Yang, Xi; Wang, Shanshan; Ghiviriga, Ion; Abboud, Khalil A.; Veige, Adam S.

    2015-05-19

    A novel synthetic method to create gold based metallo–oligomers/polymers via the combination of inorganic click (iClick) with intermolecular aurophilic interactions is demonstrated. Complexes [PEt3Au]4sub>(μ-N3C2C6H5) (1) and [PPhMe2Au]4sub (μ-N3C2C6H5) (2) and {[PEt3Au]4sub>[(μ-N3C2)2-9,9-dihexyl-9H-fluorene]}n (8) have been synthesized via iClick. The tetranuclear structures of 1 and 2, induced by aurophilic bonding, are confirmed in the solid state through single crystal X-ray diffraction experiments and in solution via variable temperature NMR spectroscopy. The extended 1D structure of 8 is constructed by aurophilic induced self-assembly. 1H DOSY NMR analysis reveals that the aurophilic bonds in 1, 2, and 8 are retained in the solution phase. The degree of polymerization within complex 8 is temperature and concentration dependent, as determined by 1H DOSY NMR. The complex 8 is a rare example of a solution stable higher ordered structure linked by aurophilic interactions.

  8. Magnetic excitations in the spin-1/2 triangular-lattice antiferromagnet Cs2CuBr4sub>

    SciTech Connect

    Zvyagin, S. A.; Ozerov, M.; Kamenskyi, D.; Wosnitza, J.; Krzystek, J.; Yoshizawa, D.; Hagiwara, M.; Hu, Rongwei; Ryu, Hyejin; Petrovic, C.; Zhitomirsky, M. E.

    2015-11-27

    We present on high- field electron spin resonance (ESR) studies of magnetic excitations in the spin- 1/2 triangular-lattice antiferromagnet Cs2CuBr4sub>. Frequency- field diagrams of ESR excitations are measured for different orientations of magnetic fields up to 25 T. We show that the substantial zero- field energy gap, Δ ≈ 9.5 K, observed in the low-temperature excitation spectrum of Cs2CuBr4sub> [Zvyagin et al:, Phys. Rev. Lett. 112, 077206 (2014)], is present well above TN. Noticeably, the transition into the long-range magnetically ordered phase does not significantly affect the size of the gap, suggesting that even below TN the high-energy spin dynamics in Cs2CuBr4sub> is determined by short-range-order spin correlations. The experimental data are compared with results of model spin-wave-theory calculations for spin-1/2 triangle-lattice antiferromagnet.

  9. Graphene oxide wrapped Ag{sub 3}PO{sub 4} sub-microparticles with highly enhanced photocatalytic activity and stability under visible light irradiation

    SciTech Connect

    Xiu, Zhiliang; Wu, Yongzhong; Hao, Xiaopeng; Lu, Qifang; Liu, Suwen

    2014-11-15

    Highlights: • Graphene oxide wrapped Ag{sub 3}PO{sub 4} sub-microparticles were prepared. • The photocatalytic activity of Ag{sub 3}PO{sub 4} is increased by 6 times by GO wrapping. • The hybrid photocatalysts exhibited excellent stability. - Abstract: Graphene oxide (GO) wrapped Ag{sub 3}PO{sub 4} sub-microparticles were prepared by in situ deposition–precipitation method. By hybridization of Ag{sub 3}PO{sub 4} with GO nanosheets, a 6-fold enhancement in the photodegradation rate toward orange methyl (MO) under visible light irradiation (λ ≥ 420 nm) was observed compared with the pure Ag{sub 3}PO{sub 4} sub-microsparticles. The hybrid photocatalysts also exhibited excellent stability in the successive MO degradation experiments. The highly enhanced photocatalytic activity and stability were mainly attributed to the quick transfer of the photogenerated electrons from Ag{sub 3}PO{sub 4} to GO nanosheets, which could effectively suppress the electron–hole pairs recombination and thus inhibit the photocorrosion of Ag{sub 3}PO{sub 4}. These high-efficient and stable hybrid photocatalysts were expected to show considerable potential applications in wastewater treatment and water splitting.

  10. Crystal structure, IR and Mössbauer spectroscopy and magnetic properties of KZnFe(PO{sub 4}){sub 2} related to the zeolite-ABW-like compounds

    SciTech Connect

    Badri, Abdessalem; Hidouri, Mourad; Wattiaux, Alain; López, María Luisa; Veiga, María Luisa; Amara, Mongi Ben

    2014-07-01

    Highlights: • The reported structure of KZnFe(PO{sub 4}){sub 2} is closely related to the zeolite ABW-type. • The structure is described in detail. • The IR and Mössbauer spectroscopy results are reported. • The magnetic properties are developed. - Abstract: The new iron phosphate KZnFe(PO{sub 4}){sub 2} has been synthesized by flux method and solid state reaction, and characterized by X-ray diffraction, IR, Mössbauer spectroscopy and magnetic susceptibility. This compound crystallizes in the monoclinic space group C2/c with the cell parameters: a = 13.514(4) Å, b = 13.273(6) Å, c = 8.742(3) Å and β = 100.07(2)°. It displays strong similarities with the phosphates KCoAl(PO{sub 4}){sub 2} and NaCoPO{sub 4} and features some analogies with the zeolite-ABW structural type. 3D framework is built up by a corner-sharing between MO{sub 4} (M = 0.5 Zn + 0.5 Fe) and PO{sub 4} tetrahedra. The K{sup +} ions are found within crossing tunnels perpendicular to the (1 0 0), (0 1 0) and (0 0 1) planes, delimited by this framework. A Mössbauer study confirmed the presence of Fe{sup 3+} ions in a tetrahedral environment. Magnetic measurements revealed an antiferromagnetic behavior with T{sub N} = 8.5 K.

  11. Color tunable and thermally stable luminescence of Tb{sup 3+} doped Li{sub 4}SrCa(SiO{sub 4}){sub 2} phosphors

    SciTech Connect

    Zhang, Xinmin; Seo, Hyo Jin

    2012-08-15

    Highlights: ► Lowest spin-allowed and spin-forbidden f–d transitions locate at 250 and 280 nm. ► Cross relaxation shortens lifetime of {sup 5}D{sub 3} level, while that of {sup 5}D{sub 4} are unaffected. ► Cross-relaxation can explain concentration quenching of the {sup 5}D{sub 3} emission. ► Dipole–quadrupole interaction is responsible for the non-radiative relaxation. ► Li{sub 4}SrCa(SiO{sub 4}){sub 2}:Tb{sup 3+} is thermally stable and color tunable phosphor. -- Abstract: Tb{sup 3+} ions activated Li{sub 4}SrCa(SiO{sub 4}){sub 2} phosphors were synthesized using a solid state reaction method. The phase impurity was checked by XRD. The photoluminescence (PL) excitation spectrum, emission spectra at room and high temperature, decay curves of samples with different Tb{sup 3+} ions concentration were studied in detail. Cross-relaxation and the Inokuti–Hirayama model were used to analyze the experimental results. Li{sub 4}SrCa(SiO{sub 4}){sub 2}:xTb{sup 3+} are thermally stable and color tunable phosphors.

  12. Detecting the H3F3A mutant allele found in high-grade pediatric glioma by real-time PCR.

    PubMed

    Zhang, Ray; Han, Jing; Daniels, David; Huang, Haojie; Zhang, Zhiguo

    2016-01-01

    Diffuse intrinsic pontine glioma (DIPG) is an aggressive pediatric brain tumor with a median survival of 1 year after diagnosis. It has been reported recently that about 80% of DIPG cases and 70% of midline glioblastomas contain a mutation at one allele of the H3F3A gene (encoding histone H3 variant H3.3), replacing the lysine 27 with methionine (K27M). In order to facilitate diagnosis of DIPG patients, a quick and reliable method to identify the H3F3A K27M mutation is needed. Here, we describe a real-time PCR-based procedure involving a mutant-specific primer, a blocker oligonucleotide, and a reverse primer that can differentiate samples with H3F3A K27M mutation from those that do not. We first tested four different mutant-specific primers for their ability to selectively amplify H3F3A K27M-mutant allele and found that one primer amplified the mutant allele more efficiently than the rest. We then determined the optimal concentration of blocker oligo that significantly improved amplification of the H3F3A K27M-mutant allele. Using this optimized real-time PCR assay, we analyzed eleven samples, two of which containing H3F3A K27M mutation, and found that these two samples were differentially amplified from the nine others. In addition, we were able to discern the H3F3A K27M mutation in a newly obtained pediatric brainstem glioblastoma sample whose H3.3 status was not known previously, and in three other DIPG samples as well as paraffin embedded samples. These results demonstrate that we have developed a new reliable procedure for detecting the H3F3A K27M mutation in pediatric glioblastoma patient samples. PMID:26376656

  13. Tumultuous Relationship between the Human Immunodeficiency Virus Type 1 Viral Infectivity Factor (Vif) and the Human APOBEC-3G and APOBEC-3F Restriction Factors

    PubMed Central

    Henriet, Simon; Mercenne, Gaëlle; Bernacchi, Serena; Paillart, Jean-Christophe; Marquet, Roland

    2009-01-01

    Summary: The viral infectivity factor (Vif) is dispensable for human immunodeficiency virus type 1 (HIV-1) replication in so-called permissive cells but is required for replication in nonpermissive cell lines and for pathogenesis. Virions produced in the absence of Vif have an aberrant morphology and an unstable core and are unable to complete reverse transcription. Recent studies demonstrated that human APOBEC-3G (hA3G) and APOBEC-3F (hA3F), which are selectively expressed in nonpermissive cells, possess strong anti-HIV-1 activity and are sufficient to confer a nonpermissive phenotype. Vif induces the degradation of hA3G and hA3F, suggesting that its main function is to counteract these cellular factors. Most studies focused on the hypermutation induced by the cytidine deaminase activity of hA3G and hA3F and on their Vif-induced degradation by the proteasome. However, recent studies suggested that several mechanisms are involved both in the antiviral activity of hA3G and hA3F and in the way Vif counteracts these antiviral factors. Attempts to reconcile the studies involving Vif in virus assembly and stability with these recent findings suggest that hA3G and hA3F partially exert their antiviral activity independently of their catalytic activity by destabilizing the viral core and the reverse transcription complex, possibly by interfering with the assembly and/or maturation of the viral particles. Vif could then counteract hA3G and hA3F by excluding them from the viral assembly intermediates through competition for the viral genomic RNA, by regulating the proteolytic processing of Pr55Gag, by enhancing the efficiency of the reverse transcription process, and by inhibiting the enzymatic activities of hA3G and hA3F. PMID:19487726

  14. Tumultuous relationship between the human immunodeficiency virus type 1 viral infectivity factor (Vif) and the human APOBEC-3G and APOBEC-3F restriction factors.

    PubMed

    Henriet, Simon; Mercenne, Gaëlle; Bernacchi, Serena; Paillart, Jean-Christophe; Marquet, Roland

    2009-06-01

    The viral infectivity factor (Vif) is dispensable for human immunodeficiency virus type 1 (HIV-1) replication in so-called permissive cells but is required for replication in nonpermissive cell lines and for pathogenesis. Virions produced in the absence of Vif have an aberrant morphology and an unstable core and are unable to complete reverse transcription. Recent studies demonstrated that human APOBEC-3G (hA3G) and APOBEC-3F (hA3F), which are selectively expressed in nonpermissive cells, possess strong anti-HIV-1 activity and are sufficient to confer a nonpermissive phenotype. Vif induces the degradation of hA3G and hA3F, suggesting that its main function is to counteract these cellular factors. Most studies focused on the hypermutation induced by the cytidine deaminase activity of hA3G and hA3F and on their Vif-induced degradation by the proteasome. However, recent studies suggested that several mechanisms are involved both in the antiviral activity of hA3G and hA3F and in the way Vif counteracts these antiviral factors. Attempts to reconcile the studies involving Vif in virus assembly and stability with these recent findings suggest that hA3G and hA3F partially exert their antiviral activity independently of their catalytic activity by destabilizing the viral core and the reverse transcription complex, possibly by interfering with the assembly and/or maturation of the viral particles. Vif could then counteract hA3G and hA3F by excluding them from the viral assembly intermediates through competition for the viral genomic RNA, by regulating the proteolytic processing of Pr55(Gag), by enhancing the efficiency of the reverse transcription process, and by inhibiting the enzymatic activities of hA3G and hA3F. PMID:19487726

  15. Reattachment of Descemet's membrane using C3F8 gas in an eye with a Baerveldt aqueous shunt.

    PubMed

    Wimmersberger, Y; Bergin, C; Sharkawi, E

    2013-04-01

    Descemetʼs membrane detachment (DMD) is a rare complication following cataract and glaucoma surgery as well as lamellar graft procedures. DMD can lead to blurry vision, halos and severe visual loss. Clinically, when there is a large central detachment, a double anterior chamber is seen to form. In this scenario, surgical repair may be needed. Repair of localised DMD may be achieved by injection of gases such as perfluoropropane (C3F8) and sulfurhexafluoride (SF6) or sterile air. The effect of a functioning Baerveldt tube in situ during these injections has not been reported. We report a case of DMD repair in an eye with a Baerveldt aqueous shunt. PMID:23629780

  16. Coexistence of ferromagnetism and superconductivity in CeO_{0.3}F_{0.7}BiS_{2}

    SciTech Connect

    Lee, Jooseop; Demura, S; Stone, Matthew B; Iida, Kazuki; Ehlers, Georg; Dela Cruz, Clarina R; Matsuda, Masaaki; Deguchi, K; Mizuguchi, Y; Miura, O; Louca, Despina; Lee, Seung-Hun

    2014-01-01

    Bulk magnetization, transport and neutron scattering measurements were performed to investigate the electronic and magnetic properties of a polycrystalline sample of the newly discovered ferromagnetic superconductor, CeO0:3F0:7BiS2. Ferromagnetism develops below TFM = 6.54(8) K and superconductivity is found to coexist with the ferromagnetic state below TSC 4.5 K. Inelastic neutron scattering measurements reveal a very weakly dispersive magnetic excitation at 1.8 meV that can be explained by an Ising-like spin Hamiltonian. Under application of an external magnetic eld, the direction of the magnetic moment changes from the c-axis to the ab-plane and the 1.8 meV excitation splits into two modes. A possible mechanism for the unusual magnetism and its relation to superconductivity is discussed.

  17. Mechanism and nature of phase transitions in the (NH4)3MoO3F3 oxyfluoride

    NASA Astrophysics Data System (ADS)

    Flerov, I. N.; Fokina, V. D.; Bovina, A. F.; Bogdanov, E. V.; Molokeev, M. S.; Kocharova, A. G.; Pogorel'Tsev, E. I.; Laptash, N. M.

    2008-03-01

    The temperature dependences of the heat capacity, the unit cell parameter, and the permittivity for the (NH4)3MoO3F3 cryolite (space group Fm overline 3 m) are investigated. It is revealed that the compound undergoes ferroelectric and ferroelastic structural phase transitions at temperatures of 297 and 205 K, respectively. The mechanism of structural distortions is discussed in terms of the entropy parameters, pressure-temperature phase diagrams, and electron density maps for critical atoms. An analysis is made of the influence of the cation size and shape on the phase transitions in oxyfluorides of the general formula A 2 A' MO3 ( A,A' = NH4, K; M = Mo, W).

  18. Carcinogenicity study of GSM and DCS wireless communication signals in B6C3F1 mice.

    PubMed

    Tillmann, Thomas; Ernst, Heinrich; Ebert, Sven; Kuster, Niels; Behnke, Wolfgang; Rittinghausen, Susanne; Dasenbrock, Clemens

    2007-04-01

    The purpose of this study using a total of 1170 B6C3F1 mice was to detect and evaluate possible carcinogenic effects in mice exposed to radio-frequency-radiation (RFR) from Global System for Mobile Communication (GSM) and Digital Personal Communications System (DCS) handsets as emitted by handsets operating in the center of the communication band, that is, at 902 MHz (GSM) and 1747 MHz (DCS). Restrained mice were exposed for 2 h per day, 5 days per week over a period of 2 years to three different whole-body averaged specific absorption rate (SAR) levels of 0.4, 1.3, 4.0 mW/g bw (SAR), or were sham exposed. Regarding the organ-related tumor incidence, pairwise Fisher's test did not show any significant increase in the incidence of any particular tumor type in the RF exposed groups as compared to the sham exposed group. Interestingly, while the incidences of hepatocellular carcinomas were similar in EMF and sham exposed groups, in both studies the incidences of liver adenomas in males decreased with increasing dose levels; the incidences in the high dose groups were statistically significantly different from those in the sham exposed groups. Comparison to published tumor rates in untreated mice revealed that the observed tumor rates were within the range of historical control data. In conclusion, the present study produced no evidence that the exposure of male and female B6C3F1 mice to wireless GSM and DCS radio frequency signals at a whole body absorption rate of up to 4.0 W/kg resulted in any adverse health effect or had any cumulative influence on the incidence or severity of neoplastic and non-neoplastic background lesions, and thus the study did not provide any evidence of RF possessing a carcinogenic potential. PMID:17019729

  19. Genistein modulation of streptozotocin diabetes in male B6C3F1 mice can be induced by diet

    PubMed Central

    Guo, Tai L.; Wang, Yunbiao; Xiong, Tao; Ling, Xiao; Zheng, Jianfeng

    2014-01-01

    Diet and phytoestrogens affect the development and progression of diabetes. The objective of the present study was to determine if oral exposure to phytoestrogen genistein (GE) by gavage changed blood glucose levels (BGL) through immunomodulation in streptozotocin (STZ)-induced diabetic male B6C3F1 mice fed three different diets. These three diets were: NTP-2000 diet (NTP), soy- and alfalfa-free 5K96 diet (SOF) and high fat diet (HFD) with 60% of kcal from fat, primarily rendered fat of swine. The dosing regimen for STZ consisted of three 100 mg/kg doses (i.p.): the first dose was administered at approximately 2 weeks following the initiation of daily GE (20 mg/kg) gavage, and the second dose was on day 19 following the first dose, and the third dose was on day 57 following the first dose. In mice on the NTP diet, GE treatment decreased BGL with statistical significances observed on days 33 and 82 following the first STZ injection. In mice fed the HFD diet, GE treatment produced a significant decrease and a significant increase in BGL on days 15 and 89 following the first STZ injection, respectively. In mice fed the SOF diet, GE treatment had no significant effects on BGL. Although GE treatment affected phenotypic distributions of both splenocytes (T cells, B cells, natural killer cells and neutrophils) and thymocytes (CD4/CD8 and CD44/CD25), and their mitochondrial transmembrane potential and generation of reactive oxygen species, indicators of cell death (possibly apoptosis), GE modulation of neutrophils was more consistent with its diabetogenic or anti-diabetic potentials. The differential effects of GE on BGL in male B6C3F1 mice fed three different diets with varied phytoestrogen contents suggest that the estrogenic properties of this compound may contribute to its modulation of diabetes. PMID:25178718

  20. Genotoxicity of malachite green and leucomalachite green in female Big Blue B6C3F1 mice.

    PubMed

    Mittelstaedt, Roberta A; Mei, Nan; Webb, Peggy J; Shaddock, Joseph G; Dobrovolsky, Vasily N; McGarrity, Lynda J; Morris, Suzanne M; Chen, Tao; Beland, Frederick A; Greenlees, Kevin J; Heflich, Robert H

    2004-07-11

    Malachite green, a triphenylmethane dye used in aquaculture as an antifungal agent, is rapidly reduced in vivo to leucomalachite green. Previous studies in which female B6C3F1 mice were fed malachite green produced relatively high levels of liver DNA adducts after 28 days, but no significant induction of liver tumors was detected in a 2-year feeding study. Comparable experiments conducted with leucomalachite green resulted in relatively low levels of liver DNA adducts but a dose-responsive induction of liver tumors. In the present study, we fed transgenic female Big Blue B6C3F1 mice with 450 ppm malachite green and 204 and 408 ppm leucomalachite green (the high doses used in the tumor bioassays) and evaluated genotoxicity after 4 and 16 weeks of treatment. Neither malachite green nor leucomalachite green increased the peripheral blood micronucleus frequency or Hprt lymphocyte mutant frequency at either time point; however, the 16-week treatment with 408 ppm leucomalachite green did increase the liver cII mutant frequency. Similar increases in liver cII mutant frequency were not seen in the mice treated for 16 weeks with malachite green or in female Big Blue rats treated with a comparable dose of leucomalachite green for 16 weeks in a previous study [Mutat. Res. 547 (2004) 5]. These results indicate that leucomalachite green is an in vivo mutagen in transgenic female mouse liver and that the mutagenicities of malachite green and leucomalachite green correlate with their tumorigenicities in mice and rats. The lack of increased micronucleus frequencies and lymphocyte Hprt mutants in female mice treated with leucomalachite green suggests that its genotoxicity is targeted to the tissue at risk for tumor induction. PMID:15238237

  1. Immunomodulatory effects of black cohosh (Actaea racemosa) extract in female B6C3F1/N mice

    PubMed Central

    Smith, Matthew J.; Germolec, Dori R.; Frawley, Rachel P.; White, Kimber L.

    2013-01-01

    Black cohosh extracts (BCE; Actaea racemosa) are being used worldwide as an alternative to hormone replacement therapy for the management of menstrual and menopausal symptoms, yet the effects of BCE on the immune system are largely unknown. Female B6C3F1/N mice were treated daily with BCE (0, 62.5, 125, 250, 500, or 1000 mg/kg) for 28 days by oral gavage. Liver weights were significantly increased (26%–32%) at the 1000 mg/kg dose. Dose-related increases in mean corpuscular volume and mean corpuscular hemoglobin were observed. Decreasing trends were observed in all thymic T cell populations, with the most notable dose-responsive effects on immature thymocytes. In the spleen, dose-related decreases were observed in all cell phenotypes evaluated, reaching the level of statistical significance at the 1000 mg/kg BCE dose. Splenic natural killer (NK) cell numbers were significantly decreased at all BCE doses, with the exception of absolute NK numbers at the 125 mg/kg dose. No effects were observed on T-dependent antibody responses of the humoral immune system, including the antibody-forming cell response to sheep erythrocytes (sRBC) and IgM antibody levels to both sRBC and keyhole limpet hemocyanin. Cytotoxic T cell (TCTL) activity was increased, as was the mixed leukocyte response in one of two studies. Anti-CD3 mediated proliferation and the delayed-type hypersensitivity response were unaffected. No effects were observed on innate immunity or on bone marrow cellularity and colony-forming units. Overall, BCE exposure in B6C3F1/N mice for 28 days at doses up to 1000 mg/kg had minimal immune effects, with the exception of an increased TCTL response. PMID:23571075

  2. Immunomodulatory effects of black cohosh (Actaea racemosa) extract in female B6C3F1/N mice.

    PubMed

    Smith, Matthew J; Germolec, Dori R; Frawley, Rachel P; White, Kimber L

    2013-06-01

    Black cohosh extracts (BCE; Actaea racemosa) are being used worldwide as an alternative to hormone replacement therapy for the management of menstrual and menopausal symptoms, yet the effects of BCE on the immune system are largely unknown. Female B6C3F1/N mice were treated daily with BCE (0, 62.5, 125, 250, 500, or 1000mg/kg) for 28 days by oral gavage. Liver weights were significantly increased (26-32%) at the 1000mg/kg dose. Dose-related increases in mean corpuscular volume and mean corpuscular hemoglobin were observed. Decreasing trends were observed in all thymic T cell populations, with the most notable dose-responsive effects on immature thymocytes. In the spleen, dose-related decreases were observed in all cell phenotypes evaluated, reaching the level of statistical significance at the 1000mg/kg BCE dose. Splenic natural killer (NK) cell numbers were significantly decreased at all BCE doses, with the exception of absolute NK numbers at the 125mg/kg dose. No effects were observed on T-dependent antibody responses of the humoral immune system, including the antibody-forming cell response to sheep erythrocytes (sRBC) and IgM antibody levels to both sRBC and keyhole limpet hemocyanin. Cytotoxic T cell (TCTL) activity was increased, as was the mixed leukocyte response in one of two studies. Anti-CD3 mediated proliferation and the delayed-type hypersensitivity response were unaffected. No effects were observed on innate immunity or on bone marrow cellularity and colony-forming units. Overall, BCE exposure in B6C3F1/N mice for 28 days at doses up to 1000mg/kg had minimal immune effects, with the exception of an increased TCTL response. PMID:23571075

  3. Genistein modulation of streptozotocin diabetes in male B6C3F1 mice can be induced by diet.

    PubMed

    Guo, Tai L; Wang, Yunbiao; Xiong, Tao; Ling, Xiao; Zheng, Jianfeng

    2014-11-01

    Diet and phytoestrogens affect the development and progression of diabetes. The objective of the present study was to determine if oral exposure to phytoestrogen genistein (GE) by gavage changed blood glucose levels (BGL) through immunomodulation in streptozotocin (STZ)-induced diabetic male B6C3F1 mice fed with three different diets. These three diets were: NTP-2000 diet (NTP), soy- and alfalfa-free 5K96 diet (SOF) and high fat diet (HFD) with 60% of kcal from fat, primarily rendered fat of swine. The dosing regimen for STZ consisted of three 100mg/kg doses (i.p.): the first dose was administered at approximately 2weeks following the initiation of daily GE (20mg/kg) gavage, and the second dose was on day 19 following the first dose, and the third dose was on day 57 following the first dose. In mice on the NTP diet, GE treatment decreased BGL with statistical significances observed on days 33 and 82 following the first STZ injection. In mice fed the HFD diet, GE treatment produced a significant decrease and a significant increase in BGL on days 15 and 89 following the first STZ injection, respectively. In mice fed the SOF diet, GE treatment had no significant effects on BGL. Although GE treatment affected phenotypic distributions of both splenocytes (T cells, B cells, natural killer cells and neutrophils) and thymocytes (CD4/CD8 and CD44/CD25), and their mitochondrial transmembrane potential and generation of reactive oxygen species, indicators of cell death (possibly apoptosis), GE modulation of neutrophils was more consistent with its diabetogenic or anti-diabetic potentials. The differential effects of GE on BGL in male B6C3F1 mice fed with three different diets with varied phytoestrogen contents suggest that the estrogenic properties of this compound may contribute to its modulation of diabetes. PMID:25178718

  4. On the role of the VO(H{sub 2}PO{sub 4}){sub 2} precursor for n-butane oxidation into maleic anhydride

    SciTech Connect

    Sananes, M.T. |; Hutchings, G.J.; Volta, J.C.

    1995-07-01

    The catalytic role of VO(H{sub 2}PO{sub 4}){sub 2}, the precursor of the VO(PO{sub 3}){sub 2} phase, has been studied for N-butane oxidation to maleic anhydride. By comparison with the activated VPO catalyst, derived from the VOHPO{sub 4} {center_dot} 0.5H{sub 2}O precursor phase, VO(H{sub 2}PO{sub 4}){sub 2} gives a highly selective final catalyst. The total oxidation products CO and CO{sub 2} are not observed under any of the conditions examined, a result confirmed by extensive catalyst testing and carbon mass balances. The final catalyst derived from VO(H{sub 2}PO{sub 4}){sub 2} has a low surface area, ca. 1 m{sup 2}/g, and consequently demonstrates low specific activity on the basis of n-butane conversion per unit mass. However, the intrinsic activity (activity per unit surface area) is found to be higher than that for catalysts derived from VOHPO{sub 4}{center_dot}0.5H{sub 2}O. Since some VO(H{sub 2}PO{sub 4}){sub 2} is present in VOHPO{sub 4}{center_dot}0.5H{sub 2}O, which is the precursor of the industrial catalyst, the results of this study complicate the simple model in which the (VO){sub 2}O{sub 7} phase derived from VOHPO{sub 4} {center_dot}0.5H{sub 2}O is responsible for the selective oxidation of n-butane. The observation that the precursor VO(H{sub 2}PO{sub 4}){sub 2} can generate catalysts of high specific activity and of total selectivity to partial oxidation products might provide a useful insight into the design of a new series of high activity and high selectivity partial oxidation catalysts. 36 refs., 12 figs., 2 tabs.

  5. Saltpotentin Version3.f

    2008-06-25

    The program inverts gravity and/or gravity gradient, and/or magnetic field (magnitude, in direction of Earth's magnetic field), at a number of points, for the position of bottom of a layer, in a structure with one or multiple layers of a uniform material (e.g., salt) in a host of known (and possibly varying) background density an/or susceptibility, is specified over a 3-D collection of rectangular blocks. For marine applications, water density (and/or susceptibility) and bathmetry ismore » also specified. The interface found is the smoothest found for its level of data misfit, with the desired level of data misfie set as an input parameter. The densities and susceptibilites used for a block depend on its position relative to the interfaces. The first interface give the sea floor position. Blocks above the sea floor are treated as having the wate density and susceptibility given by the background density and susceptibility specified over the 3-D grid of blocks. For 1 even, blocks between the 1'th and 1+1'h interfaces are treated as having a uniform density and susceptibility specified as an input parameter.« less

  6. Structural, electronic and thermodynamic properties of britholites Ca{sub 10−x}La{sub x}(PO{sub 4}){sub 6−x}(SiO{sub 4}){sub x}F{sub 2} (0 ≤ x ≤ 6): Experiment and theory

    SciTech Connect

    Njema, H.; Debbichi, M.; Boughzala, K.; Said, M.; Bouzouita, K.

    2014-03-01

    Highlights: • The structural and electronic properties of apatites with the general formula Ca{sub 10−x}La{sub x}(PO{sub 4}){sub 6−x}(SiO{sub 4}){sub x}F{sub 2} (0 ≤ x ≤ 6) have been investigated by means of the density functional theory. • The calculated enthalpy of formation of the compounds increased with the substitution degree. • The decrease in stability is probably due to the disorder induced in the Ca/LaO{sub 6}F polyhedron, following the substitution. - Abstract: The apatite-type compounds Ca{sub 10−x}La{sub x}(PO{sub 4}){sub 6−x}(SiO{sub 4}){sub x}F{sub 2} with 0 ≤ x ≤ 6 were prepared using a high temperature solid state reaction and were characterized by X-ray diffraction. The crystal structure, chemical bonding, electronic structure and formation energy of all relaxed structures were analyzed by density functional theory (DFT). The calculated results show that the predicted geometry can well reproduce the structural parameters. The incorporation of La{sup 3+} into the fluorapatite (FA) structure induced especially at the level of the S(2) sites a certain disorder which is responsible for the weakening in the stability with x. Excellent agreement were obtained between the calculated and experimental results. Moreover, the band structure indicates that despite the reduction of the band gap with x content all materials remain insulating.

  7. Crystal structures of alkali-metal indium (III) phosphates of [M{sub 3}In(PO{sub 4}){sub 2}]{sub n} (M=K, n=10; M=Rb, n=2) compounds, and band structures and chemical bond properties of [Rb{sub 3}In(PO{sub 4}){sub 2}]{sub 2} crystal

    SciTech Connect

    Zhang Yongchun; Cheng Wendan . E-mail: cwd@ms.fjirsm.ac.cn; Wu Dongsheng

    2006-01-15

    Ternary indium (III) phosphates with three-dimensional frameworks, [M{sub 3}In(PO{sub 4}){sub 2}]{sub n} (M=K, n=10; M=Rb, n=2), are found and firstly reported in this paper. These compounds have been obtained by high temperature solid-state reactions and their crystal structures have been determined by single crystal X-ray diffraction analysis. The title compounds, which crystallize in monoclinic system, possess the same [In(PO{sub 4}){sub 2}]{sub n}{sup 3n-} anionic frameworks built up from interconnected InO{sub 6} octahedra and PO{sub 4} tetrahedra and have an interesting tunnel structure where M{sup +} cations are located. Optical and bonding properties of [Rb{sub 3}In(PO{sub 4}){sub 2}]{sub 2} are investigated in terms of measured absorption and emission spectra, and calculated band structures and density of states. The crystal band structures obtained by the DFT method show that the solid compound of [Rb{sub 3}In(PO{sub 4}){sub 2}]{sub 2} is an insulator with direct band gap, and the P-O covalent bond characters are larger than the In-O ones in this compound.

  8. Infrared and Raman spectra of Na{sub 2}Cu(SO{sub 4}){sub 2}{center_dot}2H{sub 2}O and (CH{sub 3}NH{sub 3}){sub 2}M(II)(SO{sub 4}){sub 2}{center_dot}6H{sub 2}O with M(II) = Cu, Zn, and Ni

    SciTech Connect

    Pillai, V.P.M.; Nayar, V.U.; Jordanovska, V.B.

    1997-11-01

    FTIR and Raman spectra of Na{sub 2}Cu(SO{sub 4}){sub 2}{center_dot}2H{sub 2}O and (CH{sub 3}NH{sub 3}){sub 2}M(II) (SO{sub 4}){sub 2}{center_dot}6H{sub 2}O with M(II) = Cu, Zn, and Ni are recorded and analyzed. Bands are assigned on the basis of SO{sub 4}{sup 2-}, CH{sub 3}NH{sub 3}{sup +}, and H{sub 2}O vibrations. The lifting of degeneracies of {nu}{sub 2}, {nu}{sub 3} and v{sub 4} modes and the appearance of {nu}{sub 1} and {nu}{sub 2} modes in the IR spectra confirm the lowering of symmetry of the SO{sub 4}{sup 2-} ion from T{sub d} to C{sub 1} in all of the title compounds. Bands obtained indicate that the distoration of the SO{sub 4}{sup 2-} ion in the four crystals are in the order, (CH{sub 3}NH{sub 3})Cu(SO{sub 4}){sub 2}{center_dot}6H{sub 2}O > (CH{sub 3}NH{sub 3}){sub 2}Ni(SO{sub 4}){sub 2}{center_dot}6H{sub 2}O > (CH{sub 3}NH{sub 3}){sub 2}Zn(SO{sub 4}){sub 2}{center_dot}6H{sub 2}O > Na{sub 2}Cu(SO{sub 4}){sub 2}{center_dot} 2H{sub 2}O. The appearance of NH{sub 3} stretching modes at wavenumbers lower than the values obtained for the free ion indicates the presence of hydrogen bonds between NH{sub 3} and SO{sub 4}{sup 2-} groups. The appearance of multiple bands in the blending and rocking mode regions and the broad nature of stretching modes show the existence of at least two symmetrically inequivalent water molecules in Na{sub 2}Cu(SO{sub 4}){sub 2}{center_dot}2H{sub 2}O. The shifting of stretching modes to lower wavenumbers and bending modes to higher wavenumbers of water molecules confirms the existence of strong hydrogen bonds in the crystal which is in agreement with the X-ray data. Bands indicate the presence of strong hydrogen bonds involving water molecules in (CH{sub 3}NH{sub 3}){sub 2}Cu(SO{sub 4}){sub 2}{center_dot}6H{sub 2}O and (CH{sub 3}NH{sub 3}){sub 2} Zn(SO{sub 4}){sub 2}{center_dot}6H{sub 2}O and of lesser strength in (CH{sub 3}NH{sub 3}){sub 2}Ni(SO{sub 4}){sub 2}{center_dot}6H{sub 2}O.

  9. Structural, electronic and optical properties of novel carbonate fluorides ABCO{sub 3}F (A=K, Rb, Cs; B=Ca, Sr)

    SciTech Connect

    Narsimha Rao, E.; Appalakondaiah, S.; Yedukondalu, N.; Vaitheeswaran, G.

    2014-04-01

    In the present study, we performed first principles calculations on the electronic and optical properties of layered alkali–alkaline earth carbonate fluorides which attract attention in the domain of nonlinear optics. The calculated lattice parameters and volumes with and without inclusion of van der Waals (vdW) correction methods to standard density functional methods were compared with experiments. We observed that vdW interactions are predominant in RbCaCO{sub 3}F and CsCaCO{sub 3}F as compared with other computed compounds. The calculated bulk modulus from single crystal elastic constants reveals that these materials are all relatively harder than the KH{sub 2}PO{sub 4} (KDP) crystal. We also found that these materials are wide band gap insulators as obtained from Tran–Blaha modified Becke–Johnson potential. The linear optical properties such as dielectric function, refractive indices, birefringence and absorption spectra are presented. Finally, the calculated birefringence values indicate that these crystals could be promising for producing phase matching in the deep ultra-violet region. - Graphical abstract: The co- and anti-parallel alignment of CO{sub 3} groups leads to larger and smaller SHG coefficients in (a) KCaCO{sub 3}F, (b) KSrCO{sub 3}F, (c) RbSrCO{sub 3}F, (d) RbCaCO{sub 3}F, and (e) CsCaCO{sub 3}F. - Highlights: • Effect of van der Waals interactions on structural properties. • Single-crystalline elastic constants and mechanical stability. • Electronic properties. • Linear optical properties. • Comparison of present computed compounds with other well known materials in non-linear optical materials.

  10. Superconductivity in the presence of disorder in skutterudite-related La3Co4sub>Sn13 and La3Ru4sub>Sn13 compounds: Electrical transport and magnetic studies

    SciTech Connect

    Slebarski, A.; Maska, M. M.; Fijalkowski, M.; McElroy, C. A.; Maple, M. B.

    2015-06-25

    La3Co4sub>Sn13 and La3Ru4sub>Sn13 were categorized as BCS superconductors. In a plot of the critical field Hc2 vs T, La3Ru4sub>Sn13 displays a second superconducting phase at the higher critical temperature Tc*, characteristic of inhomogeneous superconductors, while La3Co4sub>Sn13 shows bulk superconductivity below Tc. We observe a decrease in critical temperatures with external pressure and magnetic field for both compounds. Additionally, for La3Ru4sub>Sn13 we find that Tc*/dP>dTc/dP. The pressure dependences of Tc are interpreted according to the McMillan theory and understood to be a consequence of lattice stiffening. The investigation of the superconducting state of La3CoxRu4–xSn13 shows a Tc* that is larger then Tc for x < 4. Furthermore, this unique and unexpected observation is discussed as a result of the local disorder and/or the effect of chemical pressure when Ru atoms are partially replaced by smaller Co atoms.

  11. Study of phase relationships in the Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system. Phase diagram and thermal characteristics of phases

    SciTech Connect

    Matraszek, Aleksandra

    2013-07-15

    A diagram representing phase relationships in the Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} phosphate system has been developed on the basis of results obtained by thermal analysis (DTA/DSC/TGA) and X-ray diffraction (XRD) methods. One intermediate compound with the formula Sr{sub 3}Ce(PO{sub 4}){sub 3} occurs in the Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system at temperatures exceeding 1045 °C. The compound has a eulytite structure with the following structural parameters: a=b=c=10.1655(8) Å, α=β=γ=90.00°, V=1050.46(6) Å{sup 3}. It's melting point exceeds 1950 °C. A limited solid solution exists in the system, which possesses the structure of a low-temperature form of Sr{sub 3}(PO{sub 4}){sub 2}. At 1000 °C the maximal concentration of CePO{sub 4} in the solid solution is below 20 mol%. The solid solution phase field narrows with increased temperature. There is a eutectic point in the (Sr{sub 3}(PO{sub 4}){sub 2}+Sr{sub 3}Ce(PO{sub 4}){sub 3}) phase field at 1765 °C and 15 mol% of CePO{sub 4}. The melting temperature of Sr{sub 3}(PO{sub 4}){sub 2} is 1882±15 °C. - Graphical abstract: The phase diagram of Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system showing the stability ranges of limited solid solution and Sr{sub 3}Ce(PO{sub 4}){sub 3} phases. - Highlights: • Sr{sub 3}(PO{sub 4}){sub 2} melts at 1882 °C. • Phase diagram of Sr{sub 3}(PO{sub 4}){sub 2}–CePO{sub 4} system has been proposed. • Limited solid solution of CePO{sub 4} in Sr{sub 3}(PO{sub 4}){sub 2} forms in the system. • The Sr{sub 3}Ce(PO{sub 4}){sub 2} phosphate is stable at temperatures above 1045 °C.

  12. Crystal structures of lazulite-type oxidephosphates Ti{sup III}Ti{sup IV}{sub 3}O{sub 3}(PO{sub 4}){sub 3} and M{sup III}{sub 4}Ti{sup IV}{sub 27}O{sub 24}(PO{sub 4}){sub 24} (M{sup III}=Ti, Cr, Fe)

    SciTech Connect

    Schoeneborn, M.; Glaum, R. Reinauer, F.

    2008-06-15

    Single crystals of the oxidephosphates Ti{sup III}Ti{sup IV}{sub 3}O{sub 3}(PO{sub 4}){sub 3} (black), Cr{sup III}{sub 4}Ti{sup IV}{sub 27}O{sub 24}(PO{sub 4}){sub 24} (red-brown, transparent), and Fe{sup III}{sub 4}Ti{sup IV}{sub 27}O{sub 24}(PO{sub 4}){sub 24} (brown) with edge-lengths up to 0.3 mm were grown by chemical vapour transport. The crystal structures of these orthorhombic members (space group F2dd ) of the lazulite/lipscombite structure family were refined from single-crystal data [Ti{sup III}Ti{sup IV}{sub 3}O{sub 3}(PO{sub 4}){sub 3}: Z=24, a=7.3261(9) A, b=22.166(5) A, c=39.239(8) A, R{sub 1}=0.029, wR{sub 2}=0.084, 6055 independent reflections, 301 variables; Cr{sup III}{sub 4}Ti{sup IV}{sub 27}O{sub 24}(PO{sub 4}){sub 24}: Z=1, a=7.419(3) A, b=21.640(5) A, c=13.057(4) A, R{sub 1}=0.037, wR{sub 2}=0.097, 1524 independent reflections, 111 variables; Fe{sup III}{sub 4}Ti{sup IV}{sub 27}O{sub 24}(PO{sub 4}){sub 24}: Z=1, a=7.4001(9) A, b=21.7503(2) A, c=12.775(3) A, R{sub 1}=0.049, wR{sub 2}=0.140, 1240 independent reflections, 112 variables). For Ti{sup III}Ti{sup IV}O{sub 3}(PO{sub 4}){sub 3} a well-ordered structure built from dimers [Ti{sup III,IV}{sub 2}O{sub 9}] and [Ti{sup IV,IV}{sub 2}O{sub 9}] and phosphate tetrahedra is found. The metal sites in the crystal structures of Cr{sub 4}Ti{sub 27}O{sub 24}(PO{sub 4}){sub 24} and Fe{sub 4}Ti{sub 27}O{sub 24}(PO{sub 4}){sub 24}, consisting of dimers [M{sup III}Ti{sup IV}O{sub 9}] and [Ti{sup IV,IV}{sub 2}O{sub 9}], monomeric [Ti{sup IV}O{sub 6}] octahedra, and phosphate tetrahedra, are heavily disordered. Site disorder, leading to partial occupancy of all octahedral voids of the parent lipscombite/lazulite structure, as well as splitting of the metal positions is observed. According to Guinier photographs Ti{sup III}{sub 4}Ti{sup IV}{sub 27}O{sub 24}(PO{sub 4}){sub 24} (a=7.418(2) A, b=21.933(6) A, c=12.948(7) A) is isotypic to the oxidephosphates M{sup III}{sub 4}Ti{sup IV}{sub 27}O{sub 24}(PO{sub 4

  13. Toxicity and carcinogenicity studies of Caramel Colour IV in F344 rats and B6C3F1 mice.

    PubMed

    MacKenzie, K M; Boysen, B G; Field, W E; Petsel, S R; Chappel, C I; Emerson, J L; Stanley, J

    1992-05-01

    Caramel Colour IV, a type of caramel colour used in the manufacture of cola soft drinks, was evaluated for subchronic and chronic toxicity in rats, and carcinogenicity in Fischer-344 (F344) rats and B6C3F1 mice. In each of the studies, Caramel Colour IV was mixed with demineralized water and the solutions given to the animals ad lib. in the drinking fluid. The concentrations of Caramel Colour IV in the drinking fluid were adjusted periodically to achieve the desired caramel colour intake per kg body weight. In the range-finding studies, groups of 30 rats/sex were given Caramel Colour IV at levels of 0, 15, 20, 25 or 30 g/kg for 13 wk, and groups of 10 male rats were given levels of 0, 2.5, 5, 10 or 15 g/kg for 6 wk followed, for some dose groups, by a 2-wk withdrawal period, and then re-initiation of dosing for another 2 wk. In the rat chronic toxicity study, levels of Caramel Colour IV of 0, 2.5, 5, 7.5 or 10 g/kg were given to groups of 25 rats/sex for 12 months. The test groups in the rat and mouse carcinogenicity studies were composed of 50 animals/sex and each species was given the caramel colour at levels of 0, 0, 2.5, 5 or 10 g/kg for 24 months. In each of the studies, treated animals tended to have dose-related lower water consumption than controls. This was attributed to poor palatability of the drinking fluid, and was generally associated with decreased food consumption and body weights. Rats given caramel colour often had soft or liquid malodorous faeces although there were no treatment-related ante-mortem observations in mice. Blood biochemical changes in the rat (i.e. reduced blood urea nitrogen, alkaline phosphatase and total serum protein) appeared to be related to dietary influences and were not considered toxicologically significant. There were no treatment-related alterations in haematological variables or treatment-related differences in survival or in the incidence of benign or malignant tumours among treated and control groups and no

  14. Structure-property correlation over five phases and four transitions in Pb5Al3F19.

    PubMed

    Abrahams, S C; Ravez, J; Ritter, H; Ihringer, J

    2003-10-01

    The calorimetric and dielectric properties of Pb(5)Al(3)F(19) in the five phases stable under ambient pressure are correlated with structure for fuller characterization of each phase. The first-order transition between ferroelectric phase V and antiferroelectric phase IV at T(V,IV) = 260 (5) K exhibits a thermal hysteresis of 135 (5) K on heating, with a maximum atomic displacement Delta(xyz)(max) = 1.21 (6) A; the transition from phase IV to ferroelastic phase III at 315 (5) K is also first order but with a thermal hysteresis of 10 (5) K and Delta(xyz)(max) = 0.92 (7) A; that from phase III to paraelastic phase II at 360 (5) K is second order without hysteresis and has Delta(xyz)(max) = 0.69 (4) A; and the transition from phase II to paraelectric phase I at 670 (5) K is second or higher order, with Delta(xyz)(max) = 0.7 (4) A. The measured entropy change DeltaS at T(V,IV) agrees well with DeltaS as derived from the increased configurational energy by Stirling's approximation. For all other phase transitions, 0.5 > or = DeltaS > 0 J mol(-1) K(-1) is consistent with an entropy change caused primarily by the changes in the vibrational energy. The structure of phase III is determined both by group theoretical/normal mode analysis and by consideration of the structures of phases II, IV and V reported previously; refinement is by simultaneous Rietveld analysis of the X-ray and neutron diffraction powder profiles. The structure of prototypic phase I is predicted on the basis of the atomic arrangement in phases II, III, IV and V. The introduction of 3d electrons into the Pb(5)Al(3)F(19) lattice disturbs the structural equilibrium, the addition of 0.04% Cr(3+) causing significant changes in atomic positions and increasing T(IV,III) by approximately 15 K. Substitution of Al(3+) by 20% or more Cr(3+) eliminates the potential minima that otherwise stabilize phases IV, III and II. PMID:14586075

  15. Preparation and crystal structure of a new bismuth vanadate, Bi{sub 3.33}(VO{sub 4}){sub 2}O{sub 2}

    SciTech Connect

    Kumada, N.; Takei, T.; Haramoto, R.; Yonesaki, Y.; Dong, Q.; Kinomura, N.; Nishimoto, S.; Kameshima, Y.; Miyake, M.

    2011-06-15

    Graphical abstract: Crystal structure of Bi{sub 3.33}(VO{sub 4}){sub 2}O{sub 2}. Solid lines indicate the unit cell. Highlights: {yields} We can prepare a new bismuth vanadate, Bi{sub 3.33}(VO{sub 4}){sub 2}O{sub 2} by hydrothermal reaction using a hydrated sodium bismuthate. {yields} We clarify that the crystal structure is composed by four bismuth atoms with the coordination number of 6 or 8 and two VO{sub 4} tetrahedra. {yields} This compound exhibited photocatalytic behavior for decomposition of phenol under visible light irradiation. -- Abstract: Single crystals of a new bismuth vanadate, Bi{sub 3.33}(VO{sub 4}){sub 2}O{sub 2} was prepared by hydrothermal reaction using a hydrated sodium bismuthate, NaBiO{sub 3}.nH{sub 2}O as one of the starting compounds. The crystal structure was determined by using single crystal X-ray diffraction data. This compound crystallizes in the triclinic space group P1{sup -bar} (no. 2) with a = 7.114(1), b = 7.844(2), c = 9.372(2) A, {alpha} = 106.090(7), {beta} = 94.468(7) and {gamma} = 112.506(8){sup o}, Z = 2 and the final R factors are R1 = 0.052 and wR2 = 0.14 for 2085 unique reflections. The crystal structure is composed by four bismuth atoms with the coordination number of 6 or 8 and two VO{sub 4} tetrahedra, and one of four bismuth atoms is statistically distributed in the splitting sites with the distance of 0.83 A. This compound exhibited photocatalytic behavior for decomposition of phenol under visible light irradiation and its activity was less than that of monoclinic BiVO{sub 4}.

  16. Writing of nonlinear optical Sm{sub 2}(MoO{sub 4}){sub 3} crystal lines at the surface of glass by samarium atom heat processing

    SciTech Connect

    Abe, M.; Benino, Y.; Fujiwara, T.; Komatsu, T.; Sato, R.

    2005-06-15

    Some glasses such as 21.25Sm{sub 2}O{sub 3}.63.75MoO{sub 3}.15B{sub 2}O{sub 3} (mol %) giving the formation of nonlinear optical Sm{sub 2}(MoO{sub 4}){sub 3} crystals through conventional crystallization in an electric furnace and through continuous-wave Nd: yttrium aluminum garnet (YAG) laser (wavelength: 1064 nm) irradiation (samarium atom heat processing) have been developed. It is proposed from x-ray diffraction analyses, micro-Raman-scattering spectra, and second-harmonic generation measurements that the crystal structure of Sm{sub 2}(MoO{sub 4}){sub 3} formed by the crystallization is the {beta}{sup '}-phase structure with an orthorhombic (noncentrosymmetric) symmetry. The lines consisting of nonlinear optical {beta}{sup '}-Sm{sub 2}(MoO{sub 4}){sub 3} crystals are written at the surface of glasses by YAG laser irradiation (laser power: P=0.4 W, laser scanning speed: S=1-10 {mu}m/s), and, in particular, homogeneous crystal lines are formed at the laser scanning speed of 1 {mu}m/s. Refractive index changes (not crystallization) are also induced by YAG laser irradiation of P=0.4 W and a high laser scanning speed of S=25 {mu}m/s. The crystallization mechanism in the laser-irradiated region has been proposed. The present study demonstrates that the samarium atom heat processing is a technique for the writing of rare earth containing optical nonlinear/ferroelectric crystal lines in glass.

  17. Vacuum ultraviolet spectroscopic properties of rare earth (RE=Ce,Tb,Eu,Tm,Sm)-doped hexagonal KCaGd(PO{sub 4}){sub 2} phosphate

    SciTech Connect

    Zhang, Z. J.; Yuan, J. L.; Duan, C. J.; Xiong, D. B.; Chen, H. H.; Zhao, J. T.; Zhang, G. B.; Shi, C. S.

    2007-11-01

    Hexagonal KCaGd(PO{sub 4}){sub 2}:RE{sup 3+} (RE=Ce,Tb,Eu,Tm,Sm) were synthesized by coprecipitation method and their vacuum ultraviolet-ultraviolet (VUV-UV) spectroscopic properties were investigated. The bands at about 165 nm in the VUV excitation spectra are attributed to the host lattice absorptions. For Ce{sup 3+}-doped samples, the bands at 207, 256, 275, and 320 nm are assigned to the 4f-5d transitions of Ce{sup 3+} in KCaGd(PO{sub 4}){sub 2}. For Tb{sup 3+}-doped sample, the bands at 203 and 222 nm are related to the 4f-5d spin-allowed transitions. For Eu{sup 3+}-doped sample, the O{sup 2-}-Eu{sup 3+} charge-transfer band (CTB) at 229 nm is observed, and the fine emission spectrum of Eu{sup 3+} indicates that Eu{sup 3+} ions prefer to occupy Gd{sup 3+} or Ca{sup 2+} sites in the host lattice. For Tm{sup 3+}- and Sm{sup 3+}-doped samples, the O{sup 2-}-Tm{sup 3+} and O{sup 2-}-Sm{sup 3+} CTBs are observed to be at 176 and 186 nm, respectively. From the standpoints of the absorption band, color purity, and luminescent intensity, Tb{sup 3+}-doped KCaGd(PO{sub 4}){sub 2} is a potential candidate for 172 nm excited green plasma display phosphors.

  18. Mixed tetrahedral anionic framework in the K{sub 3}Ga{sub 2}(PO{sub 4}){sub 3} crystal structure

    SciTech Connect

    Yakubovich, O. V.; Steele, I.; Kireev, V. V.

    2008-11-15

    The crystal structure of a new synthetic potassium gallophosphate K{sub 3}Ga{sub 2}(PO{sub 4}){sub 3} grown from a solution in the melt of a mixture of GaPO{sub 4} and K{sub 2}MoO{sub 4} is determined using X-ray diffraction (Bruker Smart diffractometer, 2{theta}{sub max}= 56.6{sup o}, R = 0.044 for 2931 reflections, T = 100 K). The main crystal data are as follows: a = 8.661(2) A, b = 17.002(4) A, c = 8.386(2) A, space group Pna2{sub 1}, Z= 4, and {rho}{sub calcd} = 2.91 g/cm{sup 3}. The synthesized crystals represent the third phase in the structure type previously established for the K{sub 3}Al{sub 2}[(As,P)O{sub 4}]{sub 3} compound. It is shown that the structure consists of a three-dimensional anionic microporous tetrahedral framework of the mixed type, which is formed by PO{sub 4} and GaO{sub 4} tetrahedra shared by vertices. Large-sized cations K{sup +} occupy channels of the zeolite-like framework. The crystal chemical features of the formation of structure types of compounds with mixed frameworks described by the general formula A{sub 3}{sup +}M{sub 2}{sup 3+}(TO{sub 4}){sub 3} (where A = K, Rb, (NH{sub 4}), Tl; M = Al, Ga, Fe, Sc, Yb; T = P, As) are analyzed.

  19. Expression by midbrain dopamine neurons of Sema3A and 3F receptors is associated with chemorepulsion in vitro but a mild in vivo phenotype.

    PubMed

    Torre, Enrique R; Gutekunst, Claire-Anne; Gross, Robert E

    2010-06-01

    Here we explore the role of semaphorin 3A and 3F (Sema3A, Sema3F) in the formation of the mesotelencephalic pathway. We show that Sema3A and 3F are expressed in the ventral mesencephalon (VM) of E13.5 rat embryos; the receptors Neuropilin 1 and Neuropilin 2, and co-receptors L1CAM, NrCAM, and Plexins A1 and A3 but not A4 are expressed by VM dopaminergic neurons; these neurons bind Sema3A and 3F in vitro which induces collapse of their growth cones and elicits, with different potencies, a repulsive response; and this response is absent in axons from Nrp1 and Nrp2 null embryos. Despite these in vitro effects, only very mild anatomical defects were detected in the organization of the mesotelencephalic pathway in embryonic and adult Nrp1 or Nrp2 null mice. However, the dopaminergic meso-habenular pathway and catecholaminergic neurons in the parafascicular and paraventricular nuclei of the thalamus were significantly affected in Nrp2 null mice. These data are consistent with a model whereby Sema3A and 3F, in combination with other guidance molecules, contributes to the navigation of DA axons to their final synaptic targets. PMID:20298787

  20. Synthesis and structure of a new layered oxyfluoride Sr{sub 2}ScO{sub 3}F with photocatalytic property

    SciTech Connect

    Wang, Yongkun; Tang, Kaibin Zhu, Baichuan; Wang, Dake; Hao, Qiaoyan; Wang, Yan

    2015-05-15

    Highlights: • A new oxyfluoride compound Sr{sub 2}ScO{sub 3}F was prepared by a solid state route. • The structure of this compound was determined by GSAS program based on XRD data. • The photocatalytic property was investigated under UV irradiation. - Abstract: A new Ruddlesden–Popper type scandium oxyfluoride, Sr{sub 2}ScO{sub 3}F, was synthesized by a conventional solid state reaction route. The detailed structure of Sr{sub 2}ScO{sub 3}F was investigated using X-ray diffraction (XRD) and selected area electron diffraction (SAED). The disorder distribution pattern of fluorine anions was determined by the {sup 19}F nuclear magnetic resonance (NMR) spectrum. The compound crystallizes in a K{sub 2}NiF{sub 4}-type tetragonal structure (space group I4/mmm) with O/F anions disordered over the apical sites of the perovskite-type Sc(O,F){sub 6} octahedron layers interleaved with strontium cations. Ultraviolet–visible (UV–vis) diffuse reflection spectrum of the prepared Sr{sub 2}ScO{sub 3}F indicates that it has an absorption in the UV–vis region. The photocatalytic activity of Sr{sub 2}ScO{sub 3}F was further investigated, showing an effective photodegradation of Rhodamine-B (RB) within 2 h under UV light irradiation.

  1. Luminescence and energy transfer in Eu2+, Mn2+ co-doped Ca2SrNaLa(PO4)3F

    NASA Astrophysics Data System (ADS)

    Shanshan, Hu; Wanjun, Tang

    2013-12-01

    A new compound Ca2SrNaLa(PO4)3F, isotypic with hexagonal Ca(Sr,Na,Ca)(Ca,Sr,Ce)3(PO4)3F, is reported. Its cell parameters have been determined from X-ray powder diffraction data. Crystallization occurs in the hexagonal space group P63 (No. 173) with a = 9.515(1) Å, c = 7.028(1) Å, and Z = 2. Eu2+ and Mn2+ activated Ca2SrNaLa(PO4)3F phosphors have been prepared. The energy transfer of Eu2+ → Mn2+ has been investigated. The resonant type energy transfer from Eu2+ to Mn2+ has been demonstrated, and the energy transfer efficiency has also been calculated according to their PL decay curves. A color-tunable emission in Ca2SrNaLa(PO4)3F phosphors can be realized by Eu2+ → Mn2+ energy transfer. White light can be achieved in a single-phased Ca2SrNaLa(PO4)3F host by co-doping Eu2+ and Mn2+ with CIE (0.32, 0.31). Our results demonstrate that the potential application of these phosphors in solid-state lighting and (or) other areas.

  2. The Translation Regulatory Subunit eIF3f Controls the Kinase-Dependent mTOR Signaling Required for Muscle Differentiation and Hypertrophy in Mouse

    PubMed Central

    Csibi, Alfredo; Cornille, Karen; Leibovitch, Marie-Pierre; Poupon, Anne; Tintignac, Lionel A.; Sanchez, Anthony M. J.; Leibovitch, Serge A.

    2010-01-01

    The mTORC1 pathway is required for both the terminal muscle differentiation and hypertrophy by controlling the mammalian translational machinery via phosphorylation of S6K1 and 4E-BP1. mTOR and S6K1 are connected by interacting with the eIF3 initiation complex. The regulatory subunit eIF3f plays a major role in muscle hypertrophy and is a key target that accounts for MAFbx function during atrophy. Here we present evidence that in MAFbx-induced atrophy the degradation of eIF3f suppresses S6K1 activation by mTOR, whereas an eIF3f mutant insensitive to MAFbx polyubiquitination maintained persistent phosphorylation of S6K1 and rpS6. During terminal muscle differentiation a conserved TOS motif in eIF3f connects mTOR/raptor complex, which phosphorylates S6K1 and regulates downstream effectors of mTOR and Cap-dependent translation initiation. Thus eIF3f plays a major role for proper activity of mTORC1 to regulate skeletal muscle size. PMID:20126553

  3. Synthesis and evaluation of new antitumor 3-aminomethyl-4,11-dihydroxynaphtho[2,3-f]indole-5,10-diones.

    PubMed

    Shchekotikhin, Andrey E; Glazunova, Valeria A; Dezhenkova, Lyubov G; Luzikov, Yuri N; Buyanov, Vladimir N; Treshalina, Helena M; Lesnaya, Nina A; Romanenko, Vladimir I; Kaluzhny, Dmitry N; Balzarini, Jan; Agama, Keli; Pommier, Yves; Shtil, Alexander A; Preobrazhenskaya, Maria N

    2014-10-30

    A series of new 3-aminomethyl-4,11-dihydroxynaphtho[2,3-f]indole-5,10-diones 6-13 bearing the cyclic diamine in the position 3 of the indole ring was synthesized. The majority of new compounds demonstrated a superior cytotoxicity than doxorubicin against a panel of mammalian tumor cells with determinants of altered drug response, that is, Pgp expression or p53 inactivation. For naphtho[2,3-f]indole-5,10-diones 6-9 bearing 3-aminopyrrolidine in the side chains, the ability to bind double-stranded DNA and inhibit topoisomerases 1 and 2 mediated relaxation of supercoiled DNA were demonstrated. Only one isomer, (R)-4,11-dihydroxy-3-((pyrrolidin-3-ylamino)methyl)-1H-naphtho[2,3-f]indole-5,10-dione (7) induced the formation of specific DNA cleavage products similar to the known topoisomerase 1 inhibitors camptothecin and indenoisoquinoline MJ-III-65, suggesting a role of the structure of the side chain of 3-aminomethylnaphtho[2,3-f]indole-5,10-diones in interaction with the target. Compound 7 demonstrated an antitumor activity in mice with P388 leukemia transplants whereas its enantiomer 6 was inactive. Thus, 3-aminomethyl derivatives of 4,11-dihydroxynaphtho[2,3-f]indole-5,10-dione emerge as a new prospective chemotype for the search of antitumor agents. PMID:25244612

  4. High efficiency passively mode-locked Nd:YVO4sub> laser with direct in-band pumping at 914 nm.

    PubMed

    Waritanant, Tanant; Major, Arkady

    2016-06-13

    We report on the performance of a semiconductor saturable absorber mirror passively mode-locked Nd:YVO4sub> laser with in-band pumping at 914 nm and with the highest slope efficiency to date among the mode-locked Nd-lasers. The laser produced 6.7 W of output power with repetition rate of 87 MHz and pulse duration of 16 ps. The slope efficiency of 77.1% and the optical-to-optical efficiency of 60.7% were achieved. PMID:27410304

  5. Improved synthesis and crystal structure of the flexible pillared layer porous coordination polymer: Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN)4sub>

    SciTech Connect

    Wong-Ng, W.; Culp, J. T.; Chen, Y. S.; Zavalij, P.; Espinal, L.; Siderius, D. W.; Allen, A. J.; Scheins, S.; Matranga, C.

    2013-01-01

    This paper reports our synthesis of flexible coordination polymer, Ni(L)[Ni(CN)4sub>], (L = 1,2-bis(4-pyridyl)ethylene (nicknamed bpene)), and its structural characterization using synchrotron single crystal X-ray diffraction. The structure of the purplish crystals has been determined to be monoclinic, space group P21/m, a = 13.5941(12) Å, b = 14.3621(12) Å, c = 14.2561(12) Å, β = 96.141(2)°, V = 2767.4(4) Å3, Z = 4, Dc = 1.46 g cm-1. Ni(bpene)[Ni(CN)4sub>] assumes a pillared layer structure with layers defined by Ni[Ni(CN)4sub>]n nets and bpene ligands acting as pillars. With the present crystallization technique which involves the use of concentrated ammonium hydroxide solution and dimethyl sulfoxide (DMSO), disordered free bpene ligands and solvents of crystallization (DMSO and water molecules) occupy the pores, resulting in a formula of Ni(bpene)[Ni(CN)4sub>](1/2)bpene∙DMSO2H2O, or Ni2N7C24H25SO3. Without the inclusion of free bpene ligands and solvent molecules, the free volume is approximately 61% of the total volume; this free volume fraction is reduced to 50% with the free ligands present. Pores without the free ligands were found to have a local diameter of 5.7 Å and a main aperture of 3.5 Å. Based on the successful crystal synthesis, we also devised a new bulk synthetic technique which yielded a polycrystalline material with a significantly improved CO2 uptake as compared to the originally reported powder material. The improved synthetic technique yielded a polycrystalline material with 40% higher CO2 uptake compared to the previously reported powder material. An estimated 14.4 molecules of CO2 per unit cell was obtained.

  6. Quantum oscillations in a novel organic quasi-two-dimensional (BEDO-TTF){sub 5}[RbHg(SCN){sub 4}]{sub 2} metal

    SciTech Connect

    Lyubovskii, R. B.; Pesotskii, S. I. Perenboom, J. A. A. J.; Zhilyaeva, E. I.; Bogdanova, O. A.; Lyubovskaya, R. N.

    2008-06-15

    Quantum magnetization and magnetoresistance oscillations are detected in the quasi-two-dimensional organic metal (BEDO-TTF){sub 5}[RbHg(SCN){sub 4}]{sub 2} for the first time. The magnetization oscillation spectrum corresponds to a calculated Fermi surface provided that a magnetic breakdown is realized. The magnetoresistance oscillation spectrum contains additional frequencies, one of which can unambiguously be related to quantum interference. An analysis of the angular dependence of the magnetoresistance oscillation amplitude indicates that the many-body interactions in this metal are weak.

  7. Integrated chip-scale Si3N4sub> wavemeter with narrow free spectral range and high stability.

    PubMed

    Xiang, Chao; Tran, Minh A; Komljenovic, Tin; Hulme, Jared; Davenport, Michael; Baney, Doug; Szafraniec, Bogdan; Bowers, John E

    2016-07-15

    We designed, fabricated, and characterized an integrated chip-scale wavemeter based on an unbalanced Mach-Zehnder interferometer with 300 MHz free spectral range. The wavemeter is realized in the Si3N4sub> platform, allowing for low loss with ∼62  cm of on-chip delay. We also integrated an optical hybrid to provide phase information. The main benefit of a fully integrated wavemeter, beside its small dimensions, is increased robustness to vibrations and temperature variations and much improved stability over fiber-based solutions. PMID:27420522

  8. Widely tunable in the mid-IR BaGa4sub>Se7 optical parametric oscillator pumped at 1064  nm.

    PubMed

    Kostyukova, Nadezhda Y; Boyko, Andrey A; Badikov, Valeriy; Badikov, Dmitrii; Shevyrdyaeva, Galina; Panyutin, Vladimir; Marchev, Georgi M; Kolker, Dmitry B; Petrov, Valentin

    2016-08-01

    A BaGa4sub>Se7 nanosecond optical parametric oscillator (OPO) shows extremely wide idler tunability in the mid-IR (2.7-17 μm) under 1.064 μm pumping. The ∼10  ns pulses at ∼7.2  μm have an energy of 3.7 mJ at 10 Hz. The pump-to-idler conversion efficiency for this wavelength reaches 5.9% with a slope of 6.5% corresponding to a quantum conversion efficiency or pump depletion of 40%. PMID:27472645

  9. Unique edge-sharing sulfate-transition metal coordination in Na{sub 2}M(SO{sub 4}){sub 2} (M=Ni and Co)

    SciTech Connect

    Fry, Allyson M.; Sweeney, Owen T.; Adam Phelan, W.; Drichko, Natalia; Siegler, Maxime A.; McQueen, Tyrel M.

    2015-02-15

    Two compounds, Na{sub 2}Ni(SO{sub 4}){sub 2} and Na{sub 2}Co(SO{sub 4}){sub 2}, were synthesized and their structure and properties were characterized. They adopt a structure that contains a bidentate coordination of sulfate to the transition metal center, which was determined via single crystal X-ray diffraction combined with model refinements to both laboratory X-ray and time-of-flight neutron powder diffraction data. The compounds were both found to crystallize in the C2/c space group with Z=24 and a unit cell of a=23.3461(3) Å, b=10.3004(1) Å, c=17.4115(2) Å, β=98.8659(9)°, and V=4136.99(8) Å{sup 3} for the cobalt analog and a=23.2253(1) Å, b=10.26155(6) Å, c=17.3353(1) Å, β=99.0376(5)°, and V=4080.20(5) Å{sup 3} for the nickel analog. Magnetization measurements show that the transition metal centers have negligible interactions with neighboring sites. Infrared and Raman spectroscopies were used to further probe the unique sulfate-transition metal coordination, and confirm the bidentate binding motif. The resulting pseudo-trigonal bipyramidal coordination produces vivid violet, Na{sub 2}Co(SO{sub 4}){sub 2}, and yellow, Na{sub 2}Ni(SO{sub 4}){sub 2}, colors that were probed by diffuse reflectance. - Graphical abstract: Two blue distorted transition metal octahedra (oxygen in red) bridged by two sulfate tetrahedra are shown here. Each bridging sulfate tetrahedra shares an edge with one octahedron and a corner with the other. All of the remaining corners of the octahedra are corner sharing with four tetrahedra forming a polyhedral network. - Highlights: • Structure of Na2Ni(SO4)2 and Na2Co(SO4)2 is determined. • Unique sulfate-transition metal binding observed in the new structure. • Combined diffraction and spectroscopic techniques were used. • Magnetization measurements show negligible interactions between sites.

  10. Investigation of the structure of Cs{sub 3}(HSO{sub 4}){sub 2}(H{sub 2}PO{sub 4}) single crystals

    SciTech Connect

    Makarova, I. P. Grebenev, V. V.; Vasiliev, I. I.; Dmitricheva, E. V.; Komornikov, V. A.; Dolbinina, V. V.

    2015-07-15

    Cs{sub 3}(HSO{sub 4}){sub 2}(H{sub 2}PO{sub 4}) single crystals, obtained for the first time based on a systematic study of the phase diagram of the CsH{sub 2}PO{sub 4}–CsHSO{sub 4}–H{sub 2}O ternary system, have been studied by X-ray diffraction. The atomic structure of the crystals at room temperature is determined, and their structural features are analyzed.

  11. Reducing ultra-low thermal expansion of {beta}-Zr{sub 2}O(PO{sub 4}){sub 2} by substitutions?

    SciTech Connect

    Barreteau, Celine; Bregiroux, Damien; Laurent, Guillaume; Wallez, Gilles

    2010-12-15

    The ultra-low thermal expansion of {beta}-Zr{sub 2}O(PO{sub 4}){sub 2} could still be reduced by chemical modifications, according to previous works on uranium and thorium IV homologues that evidenced a contracting effect of big cations. However, the present study shows that the only isovalent cations likely to substitute for Zr{sup IV} or P{sup V} are either harmful, or unstable, chemically or thermally. Furthermore, aliovalent modifications seem to be forbidden by the crystal structure of the material, leaving probably very few perspectives of improvement. Vanadium however improves significantly the crystallinity of the material and lowers the {alpha}-{beta} transition temperature.

  12. Two-hour methyl isocyanate inhalation and 90-day recovery study in B6C3F1 mice

    SciTech Connect

    Boorman, G.A.; Uraih, L.C.; Gupta, B.N.; Bucher, J.R.

    1987-06-01

    B6C3F1 mice were exposed by inhalation to 0, 3, 10, and 30 ppm methyl isocyanate for 2 hr followed by a 90-day recovery period. Sixteen of eight (20%) male mice in the 30 ppm group died following exposure. There were no other unscheduled deaths in the mice. Five mice/sex/group were examined at 2 hr or at 1, 3, 7, 14, 28, 49, or 91 days following exposure. Chemical-related changes were restricted to the respiratory system. At 30 ppm there were extensive necrosis and erosion of the respiratory and olfactory epithelium in the nasal cavity. Severe necrosis and epithelial erosion were also found in the trachea and main bronchi. Regeneration of the mucosal epithelium occurred rapidly in the nasal cavity and airways. In the turbinates, mild incomplete olfactory epithelial regeneration persisted to day 91 in the male mice. Intraluminal fibrotic projections covered by respiratory epithelium and bronchial fibrosis were found in the major airways of the 30 ppm male and female mice by day 7. The intraluminal fibrosis persisted to day 91. In males with severe bronchial fibrosis, chronic alveolitis and atelectasis were found. In mice exposed to 3 or 10 ppm, persistent pulmonary changes were not found. These studies indicate that methyl isocyanate inhalation at or near lethal concentrations can cause persistent fibrosis of the major bronchi in mice.

  13. Toxicity and Carcinogenicity of Androstenedione in F344/N Rats and B6C3F1 Mice

    PubMed Central

    Blystone, Chad R.; Elmore, Susan A.; Witt, Kristine L.; Malarkey, David E.; Foster, Paul M.D.

    2011-01-01

    Androstenedione was marketed as a dietary supplement to increase muscle mass during training. Due to concern over long-term use, the NTP evaluated the subchronic and chronic toxicity and carcinogenicity of androstenedione in male and female F344/N rats and B6C3F1 mice. In subchronic studies, dose limiting effects were not observed. A chronic (two-year) exposure by gavage at 10, 20, or 50 mg/kg in rats and male mice, and 2, 10, or 50 mg/kg in female mice (50 mg/kg, maximum feasible dose) was conducted. Increased incidences of lung alveolar/bronchiolar adenoma and carcinoma occurred in the 20 mg/kg male rats and increases in mononuclear cell leukemia occurred in the 20 and 50 mg/kg female rats, which may have been related to androstenedione administration. In male and female mice, androstenedione was carcinogenic based upon a significant increase in hepatocellular tumors. A marginal increase in pancreatic islet cell adenomas in male (50 mg/kg) and female (2, 10, 50 mg/kg) mice was considered to be related to androstenedione administration. Interestingly, incidences of male rat Leydig cell adenomas and female rat mammary gland fibroadenomas decreased. In conclusion, androstenedione was determined to be carcinogenic in male and female mice, and may have been carcinogenic in rats. PMID:21651954

  14. Selective immunosuppression resulting from exposure to the carcinogenic congener of benzopyrene in B6C3F1 mice.

    PubMed Central

    Dean, J H; Luster, M I; Boorman, G A; Lauer, L D; Leubke, R W; Lawson, L

    1983-01-01

    B6C3F1 mice were exposed to two congeners of benzopyrene, either the carcinogen benzo(a)pyrene (B(a)P) or the non-carcinogen benzo(e)pyrene (B(e)P. Exposure of mice to B(a)P resulted in a reduced number of IgM and IgG antibody plaque forming cells (PFC) to the T-dependent (TD) antigen SRBC and IgM PFC's to the T-independent (TI) antigen LPS. The IgM response to hapten conjugated TI antigens was examined using TNP-LPS for reactivity of less mature B cells (B1) and TNP-Ficoll for more mature B cells (B2). Exposure to B(a)P severely depressed the TNP-Ficoll PFC response by up to 77% without altering the TNP-LPS response. These data indicated that exposure to B(a)P alters differentiation and antibody production in mature B cells to both TD and B2 TI antigens. No change in PFC was observed following exposure to B(e)P. Mishell-Dutton co-cultures confirmed that B cells were affected and that T helper cells or suppressor Mphi were not involved. Parameters of cell-mediated immunocompetence including delayed cutaneous hypersensitivity to KLH, allograft or tumour cell rejection and susceptibility to Listeria monocytogens were unaltered in B(a)P treated mice. PMID:6305542

  15. Wear Mechanism Maps for Magnesium Alloy AM60 and Composite AM60-9% (Al2O3)f

    NASA Astrophysics Data System (ADS)

    Ullah Khan, Muhammad Zafar

    The purpose of this work was to study the tribological behaviour of squeeze cast Mg alloy AM60 and its composite AM60-9% (Al2O3) f. Dry sliding wear tests were performed on specimens of these materials using a block-on-ring tribometer which was equipped with a COF and temperature measurement system. Wear, COF and temperature maps were constructed to illustrate the effect of temperature and COF on the wear behaviour of the Mg alloy and it's composite. Four wear regimes namely low, mild, transient and severe wear were identified. The transition from mild to severe wear regime was found to be dependent on the bulk temperature of the specimen. Oxidational wear prevailed in low and mild wear whereas plastic deformation induced wear and melt wear controlled the wear rates in transient and severe wear regimes, respectively. This study shows that the incorporation of Al2O3 fibres in AM60 alloy improved the wear resistance of the resulting composite by delaying the transition from mild to severe wear.

  16. Absorption and metabolism of triclosan after application to the skin of B6C3F1 mice.

    PubMed

    Fang, Jia-Long; Vanlandingham, Michelle; Gamboa da Costa, Gonçalo; Beland, Frederick A

    2016-05-01

    Triclosan is used as an antimicrobial agent in personal care products, household items, medical devices, and clinical settings. Humans can receive lifelong exposures to triclosan; however, data on the toxicity and carcinogenicity after topical application are lacking. This study determined the absorption, distribution, metabolism, and excretion of triclosan after application to the skin of B6C3F1 mice. [(14) C(U)]triclosan (10 or 100 mg triclosan/kg body weight) was administered topically to mice in two separate experiments: a vehicle selection experiment using propylene glycol, ethanol, and a generic cosmetic cream, and a toxicokinetic experiment. Mice were killed up to 72 h after triclosan administration, and excreta and tissues were analyzed for radioactivity. Ethanol had the best properties of the vehicles evaluated. Maximum absorption was obtained at approximately 12 h after dosing. Radioactivity appeared in the excreta and in all tissues examined, with the highest levels in the gall bladder and the lowest levels in the brain. Triclosan was metabolized to triclosan sulfate, triclosan glucuronide, 2,4-dichlorophenol, and hydroxytriclosan. The metabolite profile was tissue-dependent and the predominant route of excretion was fecal. The AUC0-∞ and the Cmax of plasma and liver in females were greater than those in males. Slightly lower absorption was observed in mice with Elizabethan collars. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 609-623, 2016. PMID:25410937

  17. PLEURAL EFFECTS OF INDIUM PHOSPHIDE IN B6C3F1 MICE: NONFIBROUS PARTICULATE INDUCED PLEURAL FIBROSIS

    PubMed Central

    Kirby, Patrick J.; Shines, Cassandra J.; Taylor, Genie J.; Bousquet, Ronald W.; Price, Herman C.; Everitt, Jeffrey I.; Morgan, Daniel L.

    2010-01-01

    The mechanism(s) by which chronic inhalation of indium phosphide (InP) particles causes pleural fibrosis is not known. Few studies of InP pleural toxicity have been conducted because of the challenges in conducting particulate inhalation exposures, and because the pleural lesions developed slowly over the 2-year inhalation study. The authors investigated whether InP (1 mg/kg) administered by a single oropharyngeal aspiration would cause pleural fibrosis in male B6C3F1 mice. By 28 days after treatment, protein and lactate dehydrogenase (LDH) were significantly increased in bronchoalveolar lavage fluid (BALF), but were unchanged in pleural lavage fluid (PLF). A pronounced pleural effusion characterized by significant increases in cytokines and a 3.7-fold increase in cell number was detected 28 days after InP treatment. Aspiration of soluble InCl3 caused a similar delayed pleural effusion; however, other soluble metals, insoluble particles, and fibers did not. The effusion caused by InP was accompanied by areas of pleural thickening and inflammation at day 28, and by pleural fibrosis at day 98. Aspiration of InP produced pleural fibrosis that was histologically similar to lesions caused by chronic inhalation exposure, and in a shorter time period. This oropharyngeal aspiration model was used to provide an initial characterization of the progression of pleural lesions caused by InP. PMID:19995279

  18. Electronic structures and optical properties of Ca5(BO3)3F: a systematical first-principles study.

    PubMed

    Hu, Chun-Li; Xu, Xiang; Sun, Chuan-Fu; Mao, Jiang-Gao

    2011-10-01

    A first-principles study of the electronic structure, the linear optical properties and second-order NLO properties of calcium fluoroborate (Ca(5)(BO(3))(3)F, or CBF) crystal has been performed within density functional theory and the independent-particle approximation. The results indicate that the calculated birefringence Δn and the second-order susceptibilities are very coincident with the experimental measured values, and the χ((2)) curves show stronger anisotropy than the linear optical properties. Further analysis based on the spectral and spatial decomposition of χ((2)) reveals that the main sources of the SHG response of CBF are from the planar BO(3) groups (74%-77%) and Ca(2+) cations (23%-26%) and can be attributed to the interband electronic transition from the nonbonding O 2p states to the B 2p and Ca 4s4p states. The packing arrangement of BO(3) is the principal contributor to the significant differences among SHG tensors in CBF. Meanwhile, for a certain crystal CBF, the SHG tensors' trend can be the trend of the optical transition matrix elements, which are high when the corresponding subscript directions have more parallel BO(3) triangular planes in the structure. PMID:21918290

  19. Spectroscopy and Calculations for f-f Transitions of Tb3+ Ions in KY3F10 Nanocrystal.

    PubMed

    Zhang, Jinsu; Chen, Baojiu; Sun, Jiashi; Li, Xiangping; Cheng, Lihong; Zhong, Haiyang

    2015-06-01

    A modified Judd-Ofelt theory is used in this paper to treat the electric dipole transitions within the 4f8 configuration of Tb3+ by considering the main perturbing components. Through the energy-level calculation and the strandard tensorial analysis, the explicit distances between the 4f7 5d configuration and the 5D4 state and other lower 4f8 energy levels are determined. The rare-earth ion Tb3+ substituted at Y3+ sites in KY3F10 has the site symmetry of C4v. The standard Judd-Ofelt parameters A2(10), A2(30), A4(30), A4(50), A6(50), A4(54) and A6(54) are included in the calculation together with odd-λ parameters A1(10), A3(30), A5(50) and A5(54). The fluorescence branching ratios originating from 5D4 are calculated. Compared with the experimental measurements, the modified model yields better results than the standard Judd-Ofelt theory. PMID:26369102

  20. Toxicology studies of a chemical mixture of 25 groundwater contaminants. II. Immunosuppression in B6C3F1 mice

    SciTech Connect

    Germolec, D.R.; Yang, R.S.; Ackermann, M.F.; Rosenthal, G.J.; Boorman, G.A.; Blair, P.; Luster, M.I. )

    1989-10-01

    Concern over the potential adverse health effects of chemically contaminated groundwater has existed for many years. In general, these studies have focused on retrospective epidemiological studies for cancer risk. In the present studies, immune function was monitored in female B6C3F1 mice exposed to a chemical mixture in drinking water for either 14 or 90 days. The mixture consisted of 25 common groundwater contaminants frequently found near toxic waste dumps, as determined by EPA surveys. None of the animals developed overt signs of toxicity such as body or liver weight changes. Mice exposed to the highest dose of this mixture for 14 or 90 days showed immune function changes which could be related to rapidly proliferating cells, including suppression of hematopoietic stem cells and of antigen-induced antibody-forming cells. Some of these responses, e.g., granulocyte-macrophage colony formation, were also suppressed at lower concentrations of the chemical mixture. There were no effects on T cell function or T and B cell numbers in any of the treatment groups. Altered resistance to challenge with an infectious agent also occurred in mice given the highest concentration, which correlated with the immune function changes. Paired-water studies indicated that the immune effects were related to chemical exposure and not to decreased water intake. These results suggest that long-term exposure to contaminated groundwater may represent a risk to the immune system in humans.

  1. Investigation of third-order optical nonlinearity in KBe2BO3F2 crystal by Z-scan

    NASA Astrophysics Data System (ADS)

    Li, F.-Q.; Zong, N.; Zhang, F.-F.; Yang, J.; Yang, F.; Peng, Q.-J.; Cui, D.-F.; Zhang, J.-Y.; Wang, X.-Y.; Chen, C.-T.; Xu, Z.-Y.

    2012-08-01

    The third-order optical nonlinearity of deep-ultraviolet (DUV) nonlinear optical (NLO) crystal KBe2BO3F2 (KBBF) was investigated using single-beam Z-scan technique for the first time. The Z-scans were performed on a c-cut KBBF crystal and a KBBF prism-coupling device (PCD) with picosecond pulses at 355 nm. No two-photon absorption was observed in the experiment. The measured nonlinear refraction index n 2 showed positive signs, indicating self-focusing Kerr effects. The n 2 values were estimated to be (1.75±0.35)×10-15 cm2/W with the c-cut sample and (1.85±0.37)×10-15 cm2/W with the PCD, corresponding to the third-order nonlinear optical susceptibilities χ_{eff}^{(3)} of (0.99±0.20)×10-13 esu and (0.94±0.19)×10-13 esu, respectively. The results are expected to promote the investigation of frequency conversion processes with ultra-short laser in KBBF crystal.

  2. Luminescent properties of SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} and its luminescence improvement by incorporating A{sup +} (A=Li, Na, and K)

    SciTech Connect

    Li, Panlai Wang, Zhijun Yang, Zhiping; Guo, Qinglin

    2014-12-15

    A novel green phosphor SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} is synthesized by a high temperature solid-state method, and its luminescent property is investigated. X-ray diffraction patterns of SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} indicate a similarity crystalline phase to SrZn{sub 2}(PO{sub 4}){sub 2}. SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} shows green emission under 369 nm excitation, and the prominent luminescence in green (544 nm) due to {sup 5}D{sub 4}–{sup 7}F{sub 5} transition of Tb{sup 3+}. For the 544 nm emission, excitation spectrum has several excitation band from 200 nm to 400 nm. Emission intensity of SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} is influenced by Tb{sup 3+} concentration, and concentration quenching effect of Tb{sup 3+} in SrZn{sub 2}(PO{sub 4}){sub 2} is also observed. With incorporating A{sup +} (A=Li, Na, and K) as compensator charge, the emission intensity of SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} can be obviously enhanced. CIE color coordinates of SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} locate in the green region. The results indicate this phosphor may be a potential application in white LEDs. - Graphical abstract: SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} can produce green emission under near-UV excitation, and its luminescent properties can be improved by incorporating A{sup +} (A=Li, Na, and K). - Highlights: • SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} can produce green emission under near-UV excitation. • Concentration quenching effect of Tb{sup 3+} in SrZn{sub 2}(PO{sub 4}){sub 2} is observed. • Emission intensities of SrZn{sub 2}(PO{sub 4}){sub 2}:Tb{sup 3+} are enhanced by codoped A{sup +} (A=Li, Na, K)

  3. Synthesis and crystal structure of a new open-framework iron phosphate (NH{sub 4}){sub 4}Fe{sub 3}(OH){sub 2}F{sub 2}[H{sub 3}(PO{sub 4}){sub 4}]: Novel linear trimer of corner-sharing Fe(III) octahedra

    SciTech Connect

    Mi, Jin-Xiao; Wang, Cheng-Xin; Chen, Ning; Li, Rong; Pan, Yuanming

    2010-12-15

    A new iron phosphate (NH{sub 4}){sub 4}Fe{sub 3}(OH){sub 2}F{sub 2}[H{sub 3}(PO{sub 4}){sub 4}] has been synthesized hydrothermally at HF concentrations from 0.5 to 1.2 mL. Single-crystal X-ray diffraction analysis reveals its three-dimensional open-framework structure (monoclinic, space group P2{sub 1}/n (No. 14), a=6.2614(13) A, b=9.844(2) A, c=14.271(3) A, {beta}=92.11(1){sup o}, V=879.0(3) A{sup 3}). This structure is built from isolated linear trimers of corner-sharing Fe(III) octahedra, which are linked by (PO{sub 4}) groups to form ten-membered-ring channels along [1 0 0]. This isolated, linear trimer of corner-sharing Fe(III) octahedra, [(FeO{sub 4}){sub 3}(OH){sub 2}F{sub 2}], is new and adds to the diverse linkages of Fe polyhedra as secondary building units in iron phosphates. The trivalent iron at octahedral sites for the title compound has been confirmed by synchrotron Fe K-edge XANES spectra and magnetic measurements. Magnetic measurements also show that this compound exhibit a strong antiferromagnetic exchange below T{sub N}=17 K, consistent with superexchange interactions expected for the linear trimer of ferric octahedra with the Fe-F-Fe angle of 132.5{sup o}. -- Graphical abstract: The three-dimensional open-framework structure of (NH{sub 4}){sub 4}Fe{sub 3}(OH){sub 2}F{sub 2}[H{sub 3}(PO{sub 4}){sub 4}] is built from a novel isolated, linear (FeO{sub 4}){sub 3}(OH){sub 2}F{sub 2} trimer of corner-sharing Fe(III) octahedra linked by PO{sub 4} tetrahedra. Display Omitted

  4. Diagnostic value of H3F3A mutations in giant cell tumour of bone compared to osteoclast‐rich mimics

    PubMed Central

    Presneau, Nadège; Baumhoer, Daniel; Behjati, Sam; Pillay, Nischalan; Tarpey, Patrick; Campbell, Peter J; Jundt, Gernot; Hamoudi, Rifat; Wedge, David C; Loo, Peter Van; Hassan, A Bassim; Khatri, Bhavisha; Ye, Hongtao; Tirabosco, Roberto; Amary, M Fernanda

    2015-01-01

    Abstract Driver mutations in the two histone 3.3 (H3.3) genes, H3F3A and H3F3B, were recently identified by whole genome sequencing in 95% of chondroblastoma (CB) and by targeted gene sequencing in 92% of giant cell tumour of bone (GCT). Given the high prevalence of these driver mutations, it may be possible to utilise these alterations as diagnostic adjuncts in clinical practice. Here, we explored the spectrum of H3.3 mutations in a wide range and large number of bone tumours (n = 412) to determine if these alterations could be used to distinguish GCT from other osteoclast‐rich tumours such as aneurysmal bone cyst, nonossifying fibroma, giant cell granuloma, and osteoclast‐rich malignant bone tumours and others. In addition, we explored the driver landscape of GCT through whole genome, exome and targeted sequencing (14 gene panel). We found that H3.3 mutations, namely mutations of glycine 34 in H3F3A, occur in 96% of GCT. We did not find additional driver mutations in GCT, including mutations in IDH1, IDH2, USP6, TP53. The genomes of GCT exhibited few somatic mutations, akin to the picture seen in CB. Overall our observations suggest that the presence of H3F3A p.Gly34 mutations does not entirely exclude malignancy in osteoclast‐rich tumours. However, H3F3A p.Gly34 mutations appear to be an almost essential feature of GCT that will aid pathological evaluation of bone tumours, especially when confronted with small needle core biopsies. In the absence of H3F3A p.Gly34 mutations, a diagnosis of GCT should be made with caution.

  5. Semaphorin 3F Is a Bifunctional Guidance Cue for Dopaminergic Axons and Controls Their Fasciculation, Channeling, Rostral Growth, and Intracortical Targeting

    PubMed Central

    Kolk, Sharon M.; Gunput, Rou-Afza F.; Tran, Tracy S.; van den Heuvel, Dianne M. A.; Prasad, Asheeta A.; Hellemons, Anita J. C. G. M.; Adolfs, Youri; Ginty, David D.; Kolodkin, Alex L.; Burbach, J. Peter H.; Smidt, Marten P.; Pasterkamp, R. Jeroen

    2010-01-01

    Dopaminergic neurons in the mesodiencephalon (mdDA neurons) make precise synaptic connections with targets in the forebrain via the mesostriatal, mesolimbic, and mesoprefrontal pathways. Because of the functional importance of these remarkably complex ascending axon pathways and their implication in human disease, the mechanisms underlying the development of these connections are of considerable interest. Despite extensive in vitro studies, the molecular determinants that ensure the perfect formation of these pathways in vivo remain mostly unknown. Here, we determine the embryonic origin and ontogeny of the mouse mesoprefrontal pathway and use these data to reveal an unexpected requirement for semaphorin 3F (Sema3F) and its receptor neuropilin-2 (Npn-2) during mdDA pathway development using tissue culture approaches and analysis of sema3F−/−, npn-2−/−, and npn-2−/−;TH-Cre mice. We show that Sema3F is a bifunctional guidance cue for mdDA axons, some of which have the remarkable ability to regulate their responsiveness to Sema3F as they develop. During early developmental stages, Sema3F chemorepulsion controls previously uncharacterized aspects of mdDA pathway development through both Npn-2-dependent (axon fasciculation and channeling) and Npn-2-independent (rostral growth) mechanisms. Later on, chemoattraction mediated by Sema3F and Npn-2 is required to orient mdDA axon projections in the cortical plate of the medial prefrontal cortex. This latter finding demonstrates that regulation of axon orientation in the target field occurs by chemoattractive mechanisms, and this is likely to also apply to other neural systems. In all, this study provides a framework for additional dissection of the molecular basis of mdDA pathway development and disease. PMID:19812329

  6. Magnetic excitations from an S=1/2 diamond-shaped tetramer compound Cu2PO4sub>OH

    SciTech Connect

    Matsuda, Masaaki; Dissanayake, Sachith E.; Abernathy, Douglas L.; Totsuka, K.; Belik, A. A.

    2015-11-30

    Inelastic neutron scattering experiments have been carried out on a powder sample of Cu2PO4sub>OH, which consists of diamond-shaped tetramer spin units with S=1/2. We have observed two nearly dispersionless magnetic excitations at E1 ~2 and E2 ~0 meV, whose energy width are broader than the instrumental resolution. The simplest square tetramer model with one dominant interaction, which predicts two sharp excitation peaks at E1 and E2(=2E1), does not explain the experimental result. We found that two diagonal intratetramer interactions compete with the main interaction and weak intertetramer interactions connect the tetramers. The main intratetramer interaction is found to split into two inequivalent ones due to a structural distortion below 160 K. Cu2PO4sub>OH is considered to be a good material to study the S=1/2 Heisenberg tetramer system.

  7. Metastability in the MgAl2O4sub>-Al2O3 System

    SciTech Connect

    Wilkerson, Kelley R.; Smith, Jeffrey D.; Hemrick, James G.

    2014-07-22

    Aluminum oxide must take a spinel form ( γ-Al2O3) at elevated temperatures in order for extensive solid solution to form between MgAl2O4sub> and α-Al2O3. The solvus line between MgAl2O4sub> and Al2O3 has been defined at 79.6 wt% Al2O3 at 1500°C, 83.0 wt% Al2O3 at 1600°C, and 86.5 wt% Al2O3 at 1700°C. A metastable region has been defined at temperatures up to 1700°C which could have significant implications for material processing and properties. Additionally, initial processing could have major implications on final chemistry. The spinel solid solution region has been extended to form an infinite solid solution with Al2O3 at elevated temperatures. A minimum in melting at 1975°C and a chemistry of 96 wt% Al2O3 rather than a eutectic is present, resulting in no eutectic crystal formation during solidification.

  8. Thermodynamic Properties of α-Fe2O3 and Fe3O4sub> Nanoparticles

    SciTech Connect

    Spencer, Elinor C.; Ross, Nancy L.; Olsen, Rebecca E.; Huang, Baiyu; Kolesnikov, Alexander I.; Woodfield, Brian F.

    2015-04-21

    Here we comprehansively assessed the thermodynamic properties of hydrated α-Fe2O3 (hematite) and Fe3O4sub> (magnetite) nanoparticles. In addition to 9 nm Fe3O4sub>, three α-e2O3nanoparticles samples of different sizes (11, 14, and 25 nm) and bulk α-e2O3 have been evaluated by inelastic neutron scattering methods. The contribution of the two-level magnetic spin flip transition to the heat capacity of the α-e2O3 particles has been determined. The isochoric heat capacity of the water confined on the surface of these two types of iron oxide particles have been calculated from their INS spectra, and is affected by the chemical composition of the underlying particle. Furthermore, the heat capacity and dynamics of the particle hydration layers appear to be influenced by a complex array of factors including particle size, water coverage, and possibly the magnetic state of the particle itself.

  9. Structural instability of the CoO4sub> tetrahedral chain in SrCoO3-δ thin films

    SciTech Connect

    Glamazda, A.; Choi, Kwang-yong; Lemmens, P.; Choi, Woo Seok; Jeen, Hyoungjeen; Meyer, Tricia L.; Lee, Ho Nyung

    2015-08-31

    Raman scattering experiments together with detailed lattice dynamic calculations are performed to elucidate crystallographic and electronic peculiarities of SrCoO3-δ films. We observe that the 85 cm-1 phonon mode involving the rotation of a CoO4sub> tetrahedron undergoes a hardening by 21 cm-1 when the temperature is decreased. In addition, new phonon modes appear at 651.5 and 697.6 cm-1 . The latter modes are attributed to the Jahn-Teller activated modes. Upon cooling from room temperature, all phonons exhibit an exponential-like increase of intensity with a characteristic energy of about 103–107 K. We attribute this phenomenon to an instability of the CoO4sub> tetrahedral chain structure, which constitutes a key ingredient to understand the electronic and structural properties of the brownmillerite SrCoO2.5.

  10. Disorder from order among anisotropic next-nearest-neighbor Ising spin chains in SrHo2O4sub>

    SciTech Connect

    Wen, J. -J.; Tian, W.; Garlea, V. O.; Koohpayeh, S. M.; McQueen, T. M.; Li, H. -F.; Yan, J. -Q.; Rodriguez-Rivera, J. A.; Vaknin, D.; Broholm, C. L.

    2015-02-26

    In this study, we describe why Ising spin chains with competing interactions in SrHo2O4sub> segregate into ordered and disordered ensembles at low temperatures (T). Using elastic neutron scattering, magnetization, and specific heat measurements, the two distinct spin chains are inferred to have Néel (↑↓↑↓) and double-Néel (↑↑↓↓) ground states, respectively. Below TN = 0.68(2)K, the Néel chains develop three-dimensional long range order (LRO), which arrests further thermal equilibration of the double-Néel chains so they remain in a disordered incommensurate state for T below TS = 0.52(2)K. SrHo2O4sub> distills an important feature of incommensurate low dimensional magnetism: kinetically trapped topological defects in a quasi–d–dimensional spin system can preclude order in d + 1 dimensions.

  11. Crystal structure and electrical properties of K/sub 3/Bi/sub 2/(VO/sub 4/)/sub 3/, a new potassium bismuth vanadate

    SciTech Connect

    Debreuille-Gresse, M.F.; Abraham, F.

    1987-12-01

    K/sub 3/Bi/sub 2/(VO/sub 4/)/sub 3/ crystallizes in the space group C2/c, a = 13.957(4), b = 13.858(4), c = 7.095(2) A, ..beta.. = 112.80(3)/sup 0/, Z = 4. The crystal structure was determined from single-crystal intensity data obtained by means of an automated four-circle diffractometer and refined to the conventional values R = 0.050 and R/sub w/ = 0.059 for 1498 observed reflections. The structure is characterized by a three-dimensional network of Bi/sub 2/O/sub 10/ units and VO/sub 4/ tetrahedra. A Bi/sub 2/O/sub 10/ unit is formed by two BiO/sub 6/ octahedra sharing an edge. K/sup +/ ions occupy three different crystallographic sites. One of them has a high thermal vibration which could reflect ionic mobility. The ionic conductivity highly increases at 790 K. DSC measurements show a reversible transition at this temperature. One K atom, and only one, can be substituted by one Na atom to give NaK/sub 2/Bi/sub 2/(VO/sub 4/)/sub 3/; this substitution improves the conductivity.

  12. Magnetic order in the S=1/2 two-dimensional molecular antiferromagnet, copper pyrazine perchlorate Cu(Pz){sub 2}(ClO{sub 4}){sub 2}.

    SciTech Connect

    Lancaster, T.; Blundell, S. J.; Brooks, M. L.; Baker, P. J.; Pratt, F. L.; Manson, J. L.; Connor, M. M.; Xiao, F.; Landee, C. P.; Chaves, F. A.; Soriano, S.; Novak, M. A.; Papageorgiou, T.; Bianchi, A.; Wosnitza, J.; Schlueter, J. A.; Materials Science Division; Oxford Univ.; Rutherford Appleton Lab.; Eastern Washington Univ.; Clark Univ.; Inst. de Fisica, UFRJ; Hochfeld-Magnetlabor Dresden

    2007-01-01

    We present an investigation of magnetic ordering in the two-dimensional S=1/2 quantum magnet Cu(Pz){sub 2}(ClO{sub 4}){sub 2} using specific heat and zero-field muon-spin relaxation ({mu}{sup +}SR). The magnetic contribution to the specific heat is consistent with an exchange strength of 17.7(3) K. We find unambiguous evidence for a transition to a state of three-dimensional long-range order below a critical temperature T{sub N} = 4.21(1) K using {mu}{sup +} SR even though there is no feature in the specific heat at that temperature. The absence of a specific heat anomaly at T{sub N} is consistent with recent theoretical predictions. The ratio of T{sub N}/J=0.24 corresponds to a ratio of intralayer to interlayer exchange constants of |J{prime}/J| = 6.8 x 10{sup -4}, indicative of excellent two-dimensional isolation. The scaled magnetic specific heat of [Cu(Pz){sub 2}(HF{sub 2})]BF{sub 4}, a compound with an analogous structure, is very similar to that of Cu(Pz){sub 2}(ClO{sub 4}){sub 2} although both differ slightly from the predicted value for an ideal 2D S=1/2 Heisenberg antiferromagnet.

  13. In situ studies of surface of NiFe2O4sub> catalyst during complete oxidation of methane

    SciTech Connect

    Zhang, Shiran; Shan, Junjun; Nie, Longhui; Nguyen, Luan; Wu, Zili; Tao, Franklin

    2015-12-21

    Here, NiFe2O4sub> with an inverse spinel structure exhibits high activity for a complete oxidation of methane at 400 °C–425 °C and a higher temperature. The surface of the catalyst and its adsorbates were well characterized with ambient pressure X-ray photoelectron spectroscopy (AP-XPS) and in situ infrared spectroscopy (IR). In situ studies of the surface of NiFe2O4sub> using AP-XPS suggest the formation of methoxy-like and formate-like intermediates at a temperature lower than 200 °C, supported by the observed vibrational signatures in in situ IR studies. Evolutions of C1s photoemission features and the nominal atomic ratios of C/(Ni + Fe) of the catalyst surface suggest that the formate-like intermediate is transformed to product molecules CO2 and H2O in the temperature range of 250–300 °C. In situ studies suggest the formation of a spectator, – Olattice – CH2 – Olattice –. It strongly bonds to surface through C–O bonds and cannot be activated even at 400 °C.

  14. Monodispersed Li4sub>Ti5O12 with Controlled Morphology as High Power Lithium Ion Battery Anodes

    SciTech Connect

    Li, Yunchao; Fu, Guoyi; Watson, Mark; Harrison, Stephen; Paranthaman, M Parans

    2016-01-01

    Monodispersed Li4sub>Ti5O12 (LTO) nanoparticles with controlled microstructure were successfully synthesized by a combination of hydrolysis and hydrothermal method followed by a post-annealing process. The scanning electron microscopy images showed that particles with a size of 30-40 nm were precisely controlled throughout the synthesis process. The electrochemical tests of the as-prepared LTO electrodes in a half-cell proved its high rate performance and outstanding cyclability which benefits from the preserved well-controlled nanoparticle size and morphology. LTO electrodes were also tested in a full cell configuration in pairing with LiFePO4sub> cathodes, which demonstrated a capacity of 147.3 mAh g-1. In addition, we have also demonstrated that LTO materials prepared using lithium salts separated from geothermal brine solutions had good cyclability. These demonstrations provide a promising way for making low-cost, large-scale LTO electrode materials for energy storage applications.

  15. Conduction below 100 °C in nominal Li6ZnNb4sub>O14

    SciTech Connect

    Li, Yunchao; Paranthaman, Mariappan Parans; Gill, Lance W.; Edward W. Hagaman; Wang, Yangyang; Sokolov, Alexei P.; Dai, Sheng; Ma, Cheng; Chi, Miaofang; Veith, Gabriel M.; Manthiram, Arumugam; Goodenough, John B.

    2015-09-15

    The increasing demand for a safe rechargeable battery with a high energy density per cell is driving a search for a novel solid electrolyte with a high Li+ or Na+ conductivity that is chemically stable in a working Li-ion or Na-ion battery. Li6ZnNb4sub>O14 has been reported to exhibit a σ Li > 10-2 S cm-1 at 250 °C, but to disproportionate into multiple phases on cooling from 850 °C to room temperature. An investigation of the room-temperature Li-ion conductivity in a porous pellet of a multiphase product of a nominal Li6ZnNb4sub>O14 composition is shown to have bulk σ Li 3.3 x 10-5 S cm-1 at room temperature that increases to 1.4 x 10-4 S cm-1 by 50 °C. 7Li MAS NMR spectra were fitted to two Lorentzian lines, one of which showed a dramatic increase with increasing temperature. As a result, a test for water stability indicates that Li+ may move to the particle and grain surfaces to react with adsorbed water as occurs in the garnet Li+ conductors.

  16. Hydrothermal syntheses, structures, and properties of two new potassium vanadium phosphates: K[sub 3](VO)(V[sub 2]O[sub 3])(PO[sub 4])[sub 2](HPO[sub 4]) and K[sub 3](VO)(HV[sub 2]O[sub 3])(PO[sub 4])[sub 2](HPO[sub 4])

    SciTech Connect

    Vaughey, J.T.; Harrison, T.A.; Jacobson, A.J. )

    1994-06-01

    Two new potassium vanadium phosphates have been prepared and their structures have been determined from analysis of single crystal X-ray data. The two compounds, K[sub 3](VO)(V[sub 2]O[sub 3])(PO[sub 4])[sub 2](HPO[sub 4]) and K[sub 3](VO)(HV[sub 2]O[sub 3])(PO[sub 4])[sub 2](HPO[sub 4]), are isostructural, except for the incorporation of an extra hydrogen atom into the nearly identical frameworks. The structures consist of a three-dimensional network of [VO][sub n] chains connected through phosphate groups to a [V[sub 2]O[sub 3

  17. Electrochemically influenced cation inter-diffusion and Co3O4sub> formation on La0.6Sr0.4sub>CoO3 infiltrated into SOFC cathodes

    SciTech Connect

    Song, Xueyan; Lee, Shiwoo; Chen, Yun; Gerdes, Kirk

    2015-06-18

    Nanosized LSC electrocatalyst was infiltrated into a porous scaffold cathode composed of Sm2O3-doped CeO2 (SDC) and La0.6Sr0.4sub>Co0.2Fe0.8O3-δ (LSCF) in a commercial button solid oxide fuel cell (SOFC). To understand the stability of cathodes infiltrated with LSC, the infiltrated composite cells were subjected to both electrochemical operating and thermal aging states at 750 °C for 1500 h. Nanostructure and local chemistry evolution of La0.6Sr0.4sub>CoO3 (LSC) infiltrated cathodes upon operation and aging were investigated by transmission electron microscopy. After operation, the LSC remained a cubic perovskite, and the crystal grains exhibit comparable size to as-infiltrated LSC grains. Inter-diffusion of Fe from the LSCF to a Fe-incorporated LSC layer developed on the LSCF backbone. However, only sharp interfaces were observed between LSC and SDC backbone in the as-infiltrated cathode and such interfaces remain after operation. The infiltrated LSC on the SDC backbone also retains granular particle morphology. Furthermore, newly grown Co3O4sub> nanocrystals were found in the operated cathode. After thermal aging, on the other hand, cation inter-diffusion across the interfaces of the infiltrate particles and the cathode backbones is less than that from the operated cells. Lastly, the following hypothesis is proposed: Co3O4sub> forms on LSC arising from local charge balancing between cobalt and oxygen vacancies.

  18. Promotion of hepatic preneoplastic lesions in male B6C3F{sub 1} mice by unleaded gasoline

    SciTech Connect

    Standeven, A.M.; Wolf, D.C.; Goldsworthy, T.L.

    1995-07-01

    In previous studies, unleaded gasoline (UG) vapor was found to be a liver tumor promotor and hepatocarcinogen in female mice, but UG was not a hepatocarcinogen in male mice. However, UG vapor had similar transient mitogenic effects in nonlesioned liver of both male and female mice under the conditions of the cancer bioassay. We used an initiation-promotion protocol to determine whether UG vapor acts as a liver tumor promoter in male mice and to examine proliferative effects that may be critical to tumor development. Twelve-day-old male B6C3F{sub 1} mice were injected with N-nitrosodiethylamine (DEN; 5 mg/kg, intraperitoneally) or vehicle. Starting at 5-7 weeks of age, mice were exposed by inhalation 6 hr/day, 5 days/week for 16 weeks to 0 or 2046 ppm of PS-6 blend UG. UG treatment caused a significant 2.3-fold increase in the number of macroscopic hepatic masses in DEN-initiated mice, whereas no macroscopic masses were observed in noninitiated mice. To study hepatocyte proliferative effects of UG, we treated mice with 5-bromo-2`-deoxyuridine (BrdU) via osmotic pump for 3 days before necropsy and measured hepatocyte BruU labeling index (LI) in AHF and nonlesioned liver. UG did not significantly affect BrdU LI in nonlesioned liver. However, hepatocyte LI in AHF was about 30% higher in DEN/UG-treated mice relative to mice treated with DEN alone. These data show that UG vapor promotes AHF in male mice and that liver tumor promotion is associated with a selective increase in hepatocyte proliferation in AHF. UG acts as a liver tumor promoter in both male and female mice, and these findings contrast with the lack of hepatocarcinogenicity of UG in male mice in a cancer bioassy. 36 refs., 1 fig., 3 tabs.

  19. Characterization of uterine granular cell tumors in B6C3F1 mice: a histomorphologic, immunohistochemical, and ultrastructural study.

    PubMed

    Veit, A C; Painter, J T; Miller, R A; Hardisty, J F; Dixon, D

    2008-09-01

    The granular cell tumor is most often a benign neoplasm of uncertain origin. Four uterine granular cell tumors in control and treated female B6C3F1 mice were identified in chronic studies at the National Toxicology Program. Two tumors occurred in untreated control animals and 2 in treated animals receiving different compounds. Tissue sections were evaluated histologically and stained with hematoxylin and eosin, periodic acid-Schiff with diastase resistance, Masson's trichrome, toluidine blue, phosphotungstic acid-hematoxylin, and stained immunohistochemically with a panel of antibodies to muscle (desmin, alpha smooth muscle actin), neural (S-100, neuron specific enolase), epithelial (wide-spectrum cytokeratin), and macrophage (F4/80) markers. The main histomorphologic feature of tumor cells was the presence of abundant cytoplasmic eosinophilic granules that stained positive for periodic acid-Schiff with diastase resistance. Tumors varied in appearance and were comprised of sheets and nests of round to polygonal cells with distinct borders. Nuclei were hyperchromatic, pleomorphic, and centrally to eccentrically located and often contained single nucleoli. Occasional multinucleated giant cells were observed. Tumors were pale pink and homogeneous with trichrome stain and negative with toluidine blue. Three tumors had positive to weakly positive immunoreactivity for desmin, and 1 was positive for alpha smooth muscle actin. Expression of S-100, wide-spectrum cytokeratin, and neuron-specific enolase was negative for all tumors. Ultrastructurally, prominent electron-dense cytoplasmic granules were abundant and contained secondary lysosomes with heterogeneous lysosomal contents. The characteristics of these uterine granular cell tumors were suggestive of a myogenic origin. PMID:18725470

  20. Trichloroethylene-Induced Gene Expression and DNA Methylation Changes in B6C3F1 Mouse Liver

    PubMed Central

    Tong, Jian; Chen, Tao

    2014-01-01

    Trichloroethylene (TCE), widely used as an organic solvent in the industry, is a common contaminant in air, soil, and water. Chronic TCE exposure induced hepatocellular carcinoma in mice, and occupational exposure in humans was suggested to be associated with liver cancer. To understand the role of non-genotoxic mechanism(s) for TCE action, we examined the gene expression and DNA methylation changes in the liver of B6C3F1 mice orally administered with TCE (0, 100, 500 and 1000 mg/kg b.w. per day) for 5 days. After 5 days TCE treatment at a dose level of 1000 mg/kg b.w., a total of 431 differentially expressed genes were identified in mouse liver by microarray, of which 291 were up-regulated and 140 down-regulated. The expression changed genes were involved in key signal pathways including PPAR, proliferation, apoptosis and homologous recombination. Notably, the expression level of a number of vital genes involved in the regulation of DNA methylation, such as Utrf1, Tet2, DNMT1, DNMT3a and DNMT3b, were dysregulated. Although global DNA methylation change was not detected in the liver of mice exposed to TCE, the promoter regions of Cdkn1a and Ihh were found to be hypo- and hypermethylated respectively, which correlated negatively with their mRNA expression changes. Furthermore, the gene expression and DNA methylation changes induced by TCE were dose dependent. The overall data indicate that TCE exposure leads to aberrant DNA methylation changes, which might alter the expression of genes involved in the TCE-induced liver tumorgenesis. PMID:25549359

  1. Phosphorus-bridged ansa-metallocene complexes of titanium, zirconium, and hafnium: The syntheses and structures of [PhP(C{sub 5}Me{sub 4}){sub 2}]MX{sub 2} and [Ph(E)P(C{sub 5}Me{sub 4}){sub 2}]MX{sub 2} (E = O, S, Se) derivatives

    SciTech Connect

    Shin, J.H.; Hascall, T.; Parkin, G.

    1999-01-04

    A series of phosphorus-bridged ansa-metallocene complexes of titanium, zirconium, and hafnium, [PhP(XC{sub 5}Me{sub 4}){sub 2}]MX{sub 2} and [Ph(E)P(C{sub 5}Me{sub 4}){sub 2}]MX{sub 2} (X = Cl, Me, CO, (Se{sub 3}){sub 0.5}; E = O, S, Se), has been synthesized. Structural characterization by X-ray diffraction indicates that, in comparison to their non-ansa counterparts (C{sub 5}Me{sub 5}){sub 2}MX{sub 2}, the cyclopentadienyl groups in phosphorus-bridged complexes are displaced from symmetric {eta}{sup 5}-coordination toward {eta}{sup 3}-coordination. Such {eta}{sup 3},{eta}{sup 3}-coordination creates more electrophilic metal centers than those in their permethylcyclopentadienyl counterparts, as judged by the {nu}(CO) stretching frequencies of the zirconium dicarbonyl complexes Cp{sup *}{sub 2}Zr(CO){sub 2} (1946 and 1853 cm{sup {minus}1}) and [PhP(C{sub 5}Me{sub 4}){sub 2}]Zr(CO){sub 2} (1959 and 1874 cm{sup {minus}1}).

  2. Crystal structure and magnetic properties of NaCu{sup II}[(Cu{sup II}{sub 3}O)(PO{sub 4}){sub 2}Cl

    SciTech Connect

    Jin Tengteng; Liu Wei; Chen Shuang; Prots, Yurii; Schnelle, Walter; Zhao Jingtai; Kniep, Ruediger; Hoffmann, Stefan

    2012-08-15

    A new copper(II) oxide phosphate chloride, NaCu{sup II}[(Cu{sup II}{sub 3}O)(PO{sub 4}){sub 2}Cl], has been synthesized by flux synthesis. Single-crystal X-ray diffraction data show that the title compound crystallizes in the monoclinic system, space group P2{sub 1}/c (No. 14), with lattice parameters a=8.392(2) A, b=6.3960(10) A, c=16.670(2) A, {beta}=109.470(10) Degree-Sign , V=843.6(3) A{sup 3}, Z=4. The crystal structure is characterized by a complex chain of copper-centered polyhedra running along [0 1 0] which are connected by phosphate tetrahedra. The resulting three-dimensional polyhedra framework exhibits channels filled by additional copper and sodium atoms. Field and temperature dependent measurements of the specific heat and the magnetic susceptibility reveal low-dimensional magnetic behavior. The compound starts to decompose at 700 K under release of oxygen and evaporation of Cu{sup I}Cl as shown by simultaneous thermogravimetry and mass spectrometry. - Graphical abstract: The crystal structure of the new copper(II) phosphate chloride, NaCu{sup II}[(Cu{sup II}{sub 3}O)(PO{sub 4}){sub 2}Cl], exhibits linear chains of copper tetrahedra which show low-dimensional magnetic behavior proven by specific heat and magnetic susceptibility measurements. Highlights: Black-Right-Pointing-Pointer A new copper(II) oxide phosphate chloride, NaCu{sup II}[(Cu{sup II}{sub 3}O)(PO{sub 4}){sub 2}Cl], has been synthesized by flux synthesis. Black-Right-Pointing-Pointer The crystal structure comprises chains of Cu{sub 4}O tetrahedra. Black-Right-Pointing-Pointer Low-dimensional behavior has been proven by magnetic and specific heat measurements. Black-Right-Pointing-Pointer On heating, Cu{sup I}Cl and oxygen are released shown by simultaneous thermogravimetry and mass spectrometry.

  3. KY3F10:Er3+/Yb3+ nanocrystals doped laser-induced self-written waveguide for optical amplification in the C-band

    NASA Astrophysics Data System (ADS)

    Xue, Xiaojie; Cheng, Tonglei; Suzuki, Takenobu; Ohishi, Yasutake

    2016-02-01

    We successfully synthesized Er3+/Yb3+ co-doped KY3F10 nanocrystals by a facile hydrothermal method. The average size of the as-prepared nanocrystals was about 60 nm based on the observation of scanning electron microscope. Under the excitation of a 976 nm laser, the Er3+/Yb3+ doped KY3F10 nanocrystals showed intense near-infrared emission band centered at 1539 nm. The optimal concentrations of Er3+ were carefully selected according to the quantum yield measurement for a stronger emission in the C-band. The as-prepared nanocrystals were dispersed into a monomer, bisphenol A ethoxylate diacrylates, in which self-written waveguides can be fabricated under the irradiation of an induced laser at 450 nm. The KY3F10: Er3+/Yb3+ nanocrystals embedded polymer waveguide were fabricated by laser-induced self-written technique. Two pieces of single mode fiber were well connected with the waveguide in the fabrication procedure. Under a 976 nm laser pumping, amplified spontaneous emission at 1539 nm was observed in the KY3F10: Er3+/Yb3+ nanocrystals doped waveguide.

  4. Application of the explicitly correlated coupled-cluster models CCSD(F12*) and CC3(F12*) to the hyperpolarizability of the Ne atom

    SciTech Connect

    Hanauer, Matthias; Köhn, Andreas

    2015-01-22

    This work demonstrates the performance of the recently proposed explicitly correlated coupled-cluster method CCSD(F12*) and a new method using explicitly correlated triple excitations, CC3(F12*), in the calculation of the static ESHG hyperpolarizability of the Ne atom.

  5. CARCINOGENICITY OF CHLOROFORM IN DRINKING WATER TO MALE OSBORNE-MENDEL RATS AND FEMALE B6C3F1 MICE

    EPA Science Inventory

    The carcinogenic activity of chloroform administered at 0, 200, 400, 900, and 1800 mg/liter in drinking water was studied in male Osborne-Mendel rats and female B6C3F1 mice. A second control group was included in the study and was restricted to the water consumption of the high-d...

  6. THE INDUCTION OF HEPATOCELLULAR NEOPLASIA BY TRICHLOROACETIC ACID ADMINISTERED IN THE DRINKING WATER OF THE MALE B6C3F1 MOUSE

    EPA Science Inventory

    Summary What is the study? The study is a chronic bioassay (2 years) of trichloroacetic acid, a drinking water disinfection by-product, in the male B6C3F1 mouse.
    What is the impact to the field and the Agency?
    The impact of this study will derive from the use of...

  7. EVALUATION OF THE IMMUNOMODULATORY EFFECTS OF THE DISINFECTION BYPRODUCT, SODIUM CHLORITE, IN FEMALE B6C3F1 MICE: A DRINKING WATER STUDY

    EPA Science Inventory

    Evaluation of the Immunomodulatory Effects of the Disinfection By-product, Sodium chlorite, in Female B6C3f1 mice: A Drinking Water Study.

    Niel A. Karrow, Tal, L. Guo, J. Ann McCay, Greg W. Johnson, Ronnetta D. Brown, Debrorah L. Musgrove, Dori R. Germolec, Robert W. Lueb...

  8. DIFFERING HEPATOTOXICITY AND LETHALITY AFTER SUBACUTE TRICHLOROETHYLENE EXPOSURE IN AQUEOUS OR CORN OIL GAVAGE VEHICLES IN B6C3F1 MICE

    EPA Science Inventory

    Subacute toxicity of trichloroethylene (TCE) was evaluated in male and female B6C3F1 mice using corn oil or aqueous gavage vehicles. Mice received oral doses of TCE five times a week for 4 weeks at 600, 1200 and 2400 mg/kg/day for males and 450, 900 and 1800 mg/kg/day for females...

  9. IN VITRO PERCUTANEOUS ABSORPTION OF MONOSODIUM METHANERARSONATE (MSMA) AND DISODIUM METHANE-ARSONATE (DSMA) IN FEMALE B6C3F1 MICE

    EPA Science Inventory

    Percutaneous absorption of (14C] monosodium methanearsonate (MSMA) and disodium methanearsonate (DSMA) was investigated in female B6C3F1 mice from a variety of exposure conditions, including aqueous solution, solid compound, and soil. hese chemicals are the sodium salts of methan...

  10. Tunneling Splittings in Vibronic Structure of CH_3F^+ ( X^2E): Studied by High Resolution Photoelectron Spectra and AB Initio Theoretical Method

    NASA Astrophysics Data System (ADS)

    Mo, Yuxiang; Gao, Shuming; Dai, Zuyang; Li, Hua

    2013-06-01

    We report a combined experimental and theoretical study on the vibronic structure of CH_3F^+. The results show that the tunneling splittings of vibrational energy levels occur in CH_3F^+ due to the Jahn-Teller effect. Experimentally, we have measured a high resolution ZEKE spectrum of CH_3F up to 3500 cm^-^1 above the ground state. Theoretically, we performed an ab initio calculation based on the diabatic model. The adiabatic potential energy surfaces (APES) of CH_3F^+ have been calculated at the MRCI/CAS/avq(t)z level and expressed by Taylor expansions with normal coordinates as variables. The energy gradients for the lower and upper APES, the derivative couplings between them and also the energies of the APES have been used to determine the coefficients in the Taylor expansion. The spin-vibronic energy levels have been calculated by accounting all six vibrational modes and their couplings. The experimental ZEKE spectra were assigned based on the theoretical calculations. W. Domcke, D. R. Yarkony, and H. Köpple (Eds.), Conical Intersections: Eletronic Structure, Dynamics and Spectroscopy (World Scientific, Singapore, 2004). M. S. Schuurman, D. E. Weinberg, and D. R. Yarkony, J. Chem. Phys. 127, 104309 (2007).

  11. CARCINOGENICITY OF BROMODICHLOROMETHANE ADMINISTERED IN DRINKING WATER TO MALE F344/N RATS AND B6C3F1 MICE

    EPA Science Inventory

    A life-time exposure study was conducted to assess the carcinogenicity of bromodichloromethane (BDCM) administered in the drinking water to male F344/N rats and B6C3F1 mice. Mouse: Target concentrations of BDCM (dissolved in deionized water containing 0.25% emulphor) were 0.05, ...

  12. Search and Rescue Aircrewman/HH3F Flight Mechanic, 2-10. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This self-paced, individualized course, adapted from military curriculum materials for use in vocational and technical education, teaches students the skills needed to become a qualified avionics worker on the HH-3F helicopter. The course materials consist of three pamphlets: two student workbooks and a composite ground/flight syllabus. Each…

  13. H3F3A K27M mutation in pediatric CNS tumors: a marker for diffuse high-grade astrocytomas.

    PubMed

    Gielen, Gerrit H; Gessi, Marco; Hammes, Jennifer; Kramm, Christof M; Waha, Andreas; Pietsch, Torsten

    2013-03-01

    Brain tumors are one of the most common childhood malignancies. Diffuse high-grade gliomas represent approximately 10% of pediatric brain tumors. Exon sequencing has identified a mutation in K27M of the histone H3.3 gene (H3F3A K27M and G34R/V) in about 20% of pediatric glioblastomas, but it remains to be seen whether these mutations can be considered specific for pediatric diffuse high-grade astrocytomas or also occur in other pediatric brain tumors. We performed a pyrosequencing-based analysis for the identification of H3F3A codon 27 and codon 34 mutations in 338 pediatric brain tumors. The K27M mutation occurred in 35 of 129 glioblastomas (27.1%) and in 5 of 28 (17.9%) anaplastic astrocytomas. None of the other tumor entities showed H3F3A K27M mutation. Because H3F3A K27M mutations occur exclusively in pediatric diffuse high-grade astrocytomas, analysis of codon 27 mutational status could be useful in the differential diagnosis of these neoplasms. PMID:23429371

  14. Self-organized homo-epitaxial growth in nonlinear optical BaAlBO3F2 crystal crossing lines patterned by laser in glass

    NASA Astrophysics Data System (ADS)

    Shinozaki, K.; Abe, S.; Honma, T.; Komatsu, T.

    2015-11-01

    Crystallization processing of glasses is important as a novel technique for the development of new optical materials, and laser-induced crystallization provides a new challenge in science and technology of materials. Nonlinear optical BaAlBO3F2 crystal lines with crossing, bending, and spiral shapes were patterned at the surface of 2NiO-49BaF2-24.5Al2O3-24.5B2O3 (mol%) and 2.9NiO-48.5BaF2-24.3Al2O3-24.3B2O3 (mol%) glasses by laser irradiation (Yb:YVO4 laser with a wavelength of 1080 nm) and the orientation state of BaAlBO3F2 crystals was examined from birefringence image observations. The birefringence images indicate that the growth of highly c-axis oriented BaAlBO3F2 crystals follows along the laser scanning direction even if the laser scanning direction changes, and in particular the direction of the c-axis of BaAlBO3F2 crystals changes gradually at the crossing and bending points. The model of "self-organized homo-epitaxial growth" is proposed for the crystal orientation at the crossing and bending points, as a new crystal growth science and engineering beyond the wise providence of nature.

  15. Three-step laser excitation of the odd-parity 5s5d 3D → 5s nf 3F states of cadmium

    NASA Astrophysics Data System (ADS)

    Nadeem, Ali; Shah, M.; Haq, S. U.; Shahzada, S.; Mumtaz, M.; Waheed, A.; Nawaz, M.; Ahmed, M.; Baig, M. A.

    2014-07-01

    We report new experimental data on the term energies and effective quantum numbers of the highly excited odd parity states of cadmium in the 71 773-72 500 cm-1 energy range. The experiment was performed using three dye lasers simultaneously pumped by the second harmonic (532 nm) of the Nd;YAG laser. The vapor containment and detection system was a thermionic diode ion detector working in a space charge limited mode. The new observations include the 5snf3F3 (12 ⩽ n ⩽ 52), 5snf3F4 (13 ⩽ n ⩽ 33) and 5snf3F2 (12 ⩽ n ⩽ 22) Rydberg series excited from the 5s5d3D multiplet. A two parameter fit to the transitions energies of the 5snf3F3 series yields the binding energy of the 5snd 2D2 level as 13 042.178 ± 0.02 cm-1 and consequently the first ionization of cadmium is determined as 72 540.05 ± 0.13 cm-1, which is in good agreement with the previously reported value.

  16. EFFECT OF TRICHLOROETHYLENE ON DNA METHYLATION AND EXPRESSION OF EARLY-INTERMEDIATE PROTOONCOGENES IN THE LIVER OF B6C3F1 MICE. (R825384)

    EPA Science Inventory

    Trichloroethylene (TCE) is a multimedia environmental pollution that is carcinogenic in mouse liver. The ability of TCE to modulate DNA methylation and the expression of immediate-early protooncogenes was evaluated. Female B6C3F1 mice were administered 1000 mg/kg TCE by gavage 5 ...

  17. Global trends and annual releases of CCl3F and CCl2F2 estimated from ALE/GAGE and other measurements from July 1978 to June 1991

    NASA Technical Reports Server (NTRS)

    Cunnold, D. M.; Fraser, P. J.; Weiss, R. F.; Prinn, R. G.; Simmonds, P. G.; Miller, B. R.; Alyea, F. N.; Crawford, A. J.

    1994-01-01

    Thirteen years of Atmospheric Lifetime Experiment/Global Atmospheric Gases Experiment CCl3F and CCl2F2 measurements at five remote, surface, globally distributed sites are analyzed. Comparisons are made against shipboard measurements by the Scripps Institution of Oceanography (SIO) group and archived air samples collected at Cape Grim, Tasmania, since 1978. CCl3F in the lower troposphere was increasing at an average rate of 9.2 ppt/yr over the period July 1978 to June 1988. CCl2F2 was increasing at an average 17.3 ppt/yr in the lower troposphere over the same period. However, between July 1988 and June 1991 the increases of CCl3F and CCl2F2 in this region have averaged just 7.0 ppt/yr and 15.7 ppt/yr, respectively. The rate of increase has been decreasing 2.4 ppt/yr(exp 2) and 2.9 ppt/yr(exp 2) over this 3-year period. Based on a recent scenario of the global releases of these compounds and using the new calibration scale SIO 1993, the equilibrium lifetimes are estimated to be 44 +17/-10 and 180 +820/-81 years for CCl3F and CCl2F2, respectively. Using these lifetime estimates and a two-dimensional model, it is estimated that global releases of these two chlorofluorocarbons in 1990 were 249 +/- 28 x 10(exp 6) kg for CCl3F and 366 +/- 30 x 10(exp 6) kg for CCl2F2. It is also estimated that combined releases of these chlorofluorocarbons in 1990 were 21 +/- 5% less than those in 1986.

  18. Enhancement of the luminescent properties of a new red-emitting phosphor, Mn2(HPO3)F2, by Zn substitution.

    PubMed

    Orive, Joseba; Mesa, José L; Balda, Rolindes; Fernández, Joaquín; Fernández, Jesús Rodríguez; Rojo, Teófilo; Arriortua, María I

    2011-12-19

    The Mn(2)(HPO(3))F(2) phase has been synthesized as single crystals by using mild hydrothermal conditions. The compound crystallizes in the orthorhombic Pnma space group, with unit cell parameters of a = 7.5607(8), b = 10.2342(7), and c = 5.5156(4) Å, with Z = 4. The crystal structure consists of a three-dimensional framework formed by alternating (010) layers of [MnO(3)F(3)] octahedra linked up by three connected [HPO(3)] tetrahedra. Luminescence measurements were performed at different temperatures between 10 and 150 K. The 10 K emission spectrum of the octahedrally coordinated Mn(II) cation exhibits a broad band centered at around 615 nm corresponding to the (4)T(1) → (6)A(1) transition. In order to explore the effect of the Mn(II) concentration and the possibility of enhancing the luminescence properties of the Mn(II) cation in Mn(2)(HPO(3))F(2), different intermediate composition members of the finite solid solution with the general formula (Mn(x)Zn(1-x))(2)(HPO(3))F(2) were prepared and their luminescent properties studied. The magnetic and specific heat behavior of M(2)(HPO(3))F(2) (M = Mn, Fe) have also been investigated. The compounds exhibit a global antiferromagnetic ordering with a spin canting phenomenon detected at approximately 30 K. The specific heat measurements show sharp λ-type peaks at 29.7 and 33.5 K for manganese and iron compounds, respectively. The total magnetic entropy is consistent with spin S = 5/2 and S = 2 of Mn(II) and Fe(II) cations. PMID:22085224

  19. Hypoxia induces tumor and endothelial cell migration in a semaphorin 3F- and VEGF-dependent manner via transcriptional repression of their common receptor neuropilin 2.

    PubMed

    Coma, Silvia; Shimizu, Akio; Klagsbrun, Michael

    2011-01-01

    Neuropilin-2 (NRP2) is a receptor expressed by tumor cells and endothelial cells (EC) that binds both semaphorin 3F (SEMA3F), a potent inhibitor of tumor angiogenesis and metastasis, and vascular endothelial growth factor (VEGF), a potent stimulator of tumor angiogenesis. It was found that glioblastoma and melanoma cells repressed NRP2 expression when maintained under hypoxic conditions and after treatment with the hypoxia-mimetic agent desferrioxamine (DFO), at both the mRNA and protein levels. Silencing of HIF1-α, the hypoxia-induced subunit of the hypoxia inducible factor (HIF), abrogated DFO-induced NRP2 repression. Conversely, ectopic expression of HIF1-α directly repressed NRP2 promoter activity and expression. NRP2 is the sole receptor for SEMA3F. Loss of NRP2 expression in tumor cells inhibited SEMA3F-dependent activities, such as inactivation of RhoA, depolymerization of F-actin, and inhibition of tumor cell migration. On the other hand, loss of NRP2 expression in tumor cells increased VEGF protein levels in conditioned media, with no effects on VEGF mRNA levels. This increase in VEGF protein levels promoted paracrine activation of EC, including VEGF receptor-2 phosphorylation, and activation of downstream signaling proteins such as p44/42 MAPK and p38 MAPK. In addition, the elevated VEGF levels induced EC migration and sprouting, two key steps of tumor angiogenesis in vivo. It was concluded that hypoxia regulates VEGF and SEMA3F activities through transcriptional repression of their common receptor NRP2, providing a novel mechanism by which hypoxia induces tumor angiogenesis, growth and metastasis. PMID:21610314

  20. Crystal structure and luminescence properties of a novel red-emitting phosphor BaAlBO{sub 3}F{sub 2}:Eu{sup 3+}

    SciTech Connect

    Chen, Wanping Zhou, Ahong; Liu, Yan; Dai, Xiaoyan; Yang, Xin

    2014-12-15

    A series of novel red-emitting phosphors BaAlBO{sub 3}F{sub 2}:xEu{sup 3+} (0.001≤x≤0.08) were first synthesized via a high temperature solid-state reaction. X-ray diffraction and photoluminescence spectroscopy were used to characterize the crystal structure and photoluminescence properties of the phosphor, respectively. The phosphor can be effectively excited with a 395 nm light, and shows a dominant {sup 5}D{sub 0}−{sup 7}F{sub 2} emission with chromatic coordination of 0.628 and 0.372. The optimal doping concentration is about 0.04. Rietveld refinement results and the luminescence behavior of Eu{sup 3+} indicate that the Eu{sup 3+} ion occupies a C{sub 3} symmetry site, and the host BaAlBO{sub 3}F{sub 2} has a hexagonal structure with P-6 space group. In addition, the phosphor could be a potential candidate as red-emitting phosphor for application in white light-emitting diode. - Graphical abstract: The luminescence behavior and Rietveld refinement of BaAlBO{sub 3}F{sub 2}:Eu{sup 3+} indicate that the red-emitting phosphor has potential application in white LED and the host has a hexagonal structure with P-6 space group. - Highlights: • A novel red-emitting phosphor BaAlBO{sub 3}F{sub 2}:Eu{sup 3+} is first synthesized. • The crystal structure of BaAlBO{sub 3}F{sub 2} is confirmed. • The phosphor shows potential application in white LED.

  1. Carcinogenicity of acrylamide in B6C3F(1) mice and F344/N rats from a 2-year drinking water exposure.

    PubMed

    Beland, Frederick A; Mellick, Paul W; Olson, Greg R; Mendoza, Maria C B; Marques, M Matilde; Doerge, Daniel R

    2013-01-01

    Acrylamide is a component of roasted coffee and certain baked and fried carbohydrate-rich foods prepared at high temperatures. We have assessed the carcinogenicity of acrylamide in male and female B6C3F(1) mice and F344/N rats administered 0, 0.0875, 0.175, 0.35, or 0.70mM acrylamide in the drinking water ad libitum for 2 years. Acrylamide caused significant dose-related decreasing trends in the body weights of F344/N rats. Acrylamide administration resulted in significant dose-related decreasing trends in survival in both sexes of B6C3F(1) mice and in female F344/N rats. Histopathological analyses indicated significant dose-related increases in Harderian gland and lung tumors in male and female B6C3F(1) mice. Male B6C3F(1) mice also had a significantly increased incidence of forestomach tumors, while female B6C3F(1) mice had significant dose-related increases in mammary gland, ovary, and skin tumors. In male and female F344/N rats, there were significant increases in thyroid tumors. Male F344/N rats also had significant dose-related increases in testes, heart, and pancreas tumors, while female F344 rats demonstrated significant increases in clitoral gland, mammary gland, oral cavity, and skin tumors. These results, combined with previous mechanistic studies, provide strong support for the concept that acrylamide is activated to a carcinogen through metabolism to glycidamide. PMID:23009883

  2. 119Sn-NMR investigations on superconducting Ca3Ir4sub>Sn13: Evidence for multigap superconductivity

    SciTech Connect

    Sarkar, R.; Petrovic, C.; Bruckner, F.; Gunther, M.; Wang, Kefeng; Biswas, P. K.; Luetkens, H.; Morenzoni, E.; Amato, A.; Klauss, H. -H.

    2015-09-25

    In this study, we report bulk superconductivity (SC) in Ca3Ir4sub>Sn13 by means of 119Sn nuclear magnetic resonance (NMR) experiments. Two classical signatures of BCS superconductivity in spin-lattice relaxation rate (1/T1), namely the Hebel–Slichter coherence peak just below the Tc, and the exponential decay in the superconducting phase, are evident. The noticeable decrease of 119Sn Knight shift below Tc indicates spin-singlet superconductivity. The temperature dependence of the spin-lattice relaxation rate 119(1/T1) is convincingly described by the multigap isotropic superconducting gap. NMR experiments do not witness any sign of enhanced spin fluctuations.

  3. Theoretical crystal chemistry of M{sub x}(TO{sub 4}){sub y} sulfates and selenates: Topological analysis and classification of suprapolyhedral invariants

    SciTech Connect

    Ilyushin, G. D. Blatov, V. A.

    2006-05-15

    A geometric topological analysis of orthotetrahedral phases M{sub x}(TO{sub 4}){sub y} (T = S or Se) is performed for 46 sulfates and 17 selenates with the TOPOS 3.2 software package. The values of coordination sequences {l_brace}N{sub k}{r_brace} of T atoms are used as classification parameters of topologically different MTO nets. The crystal structures are analyzed within 12 coordination spheres of T sites and assigned to 26 topological types. It is established that only 7 types are common for the structures of sulfates and selenates, 16 types include only sulfates, and 3 types include only selenates. The average values of the bond lengths are determined: = 1.48(2) A and = 1.63(2) A. The hierarchical ordering of the crystal structure is performed using the concept of a polyhedral microensemble of the structure.

  4. Multiband Te p Based Superconductivity of Ta4sub>Pd3Te16

    SciTech Connect

    Singh, David J.

    2014-10-06

    We recently discovered that Ta4sub>Pd3Te16 is a superconductor that has been suggested to be an unconventional superconductor near magnetism. Here, we report electronic structure calculations showing that despite the layered crystal structure the material is an anisotropic three-dimensional (3D) metal. The Fermi surface contains prominent one-dimensional (1D) and two-dimensional (2D) features, including nested 1D sheets, a 2D cylindrical section, and a 3D sheet. Moreover, the electronic states that make up the Fermi surface are mostly derived from Te p states with small Ta d and Pd d contributions. This places the compound far from magnetic instabilities. The results are discussed in terms of multiband superconductivity.

  5. Beam quality management by periodic reproduction of wavefront aberrations in end-pumped Nd:YVO4sub> laser amplifiers.

    PubMed

    Liu, Bin; Liu, Chong; Shen, Lifeng; Wang, Chunhua; Ye, Zhibin; Liu, Dong; Xiang, Zhen

    2016-04-18

    A method for beam quality management is presented in a master oscillator power amplifier (MOPA) using Nd:YVO4sub> as the gain medium by extra-cavity periodic reproduction of wavefront aberrations. The wavefront aberration evolution of the intra-cavity beams is investigated for both symmetrical and asymmetrical resonators. The wavefront aberration reproduction process is successfully realized outside the cavity in four-stage amplifiers. In the MOPA with a symmetrical oscillator, the laser power increases linearly and the beam quality hardly changes. In the MOPA with an asymmetrical oscillator, the beam quality is deteriorated after the odd-stage amplifier and is improved after the even-stage amplifier. The wavefront aberration reproduction during the extra-cavity beam propagation in the amplifiers is equivalent to that during the intra-cavity propagation. This solution helps to achieve the effective beam quality management in laser amplifier chains. PMID:27137329

  6. Optical modeling and optimizations of Cu2ZnSnSe4sub> solar cells using the modified transfer matrix method.

    PubMed

    Cozza, Dario; Ruiz, Carmen M; Duché, David; Giraldo, Sergio; Saucedo, Edgardo; Simon, Jean Jacques; Escoubas, Ludovic

    2016-09-01

    The fast and computationally inexpensive Modified Transfer Matrix Method (MTM) is employed to simulate the optical response of kesterite Cu2ZnSnSe4sub> solar cells. This method can partially take into account the scattering effects due to roughness at the interfaces between the layers of the stack. We analyzed the optical behavior of the whole cell structure by varying the thickness of the TCO layer (iZnO + ITO) between 50 and 1200 nm and the buffer CdS layer between 0 and 100 nm. We propose optimal combinations of the TCO/CdS thicknesses that can locally maximize the device photocurrent. We provide experimental data that qualitatively confirm our theoretical predictions. PMID:27607723

  7. New insights into the thermodynamic behavior of 2LiBH4sub>-MgH2 composite for hydrogen storage

    SciTech Connect

    Cova, Federico; Ronnebro, Ewa; Choi, Yong-Joon; Gennari, Fabiana; Larochette, Pierre

    2015-06-15

    The composite 2LiBH4sub>:MgH2 has been studied as a possible hydrogen storage material due to its high storage capacity. The present work is directed towards the clarification of the thermodynamic behavior of the system, especially in the temperature region above 400°C. We reveal different reaction paths during hydrogen absorption and desorption at various temperatures which has important implication for applications. At temperatures higher than 413°C, the observation of two different absorption pressure plateaus indicates that two different reactions occur, however, below this temperature there is only one plateau present in the system. During desorption, the double plateau can be observed at temperatures as low as 375°C.

  8. Nanoparticles of K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}:Eu as effective detectors for swift heavy ions

    SciTech Connect

    Salah, Numan; Lochab, S. P.; Kanjilal, D.; Ranjan, Ranju; Habib, Sami S.; Rupasov, A. A.; Aleynikov, V. E.

    2007-09-15

    The modification of thermoluminescence (TL) and photoluminescence (PL) properties of K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}:Eu nanoparticles by swift heavy ions (SHI), irradiation is studied. Pellets form of the nanomaterials were irradiated by 48 MeV Li{sup 3+}, 75 MeV C{sup 6+}, and 90 MeV O{sup 7+} ion beams. The fluence range is 1x10{sup 9}-1x10{sup 13} ions/cm{sup 2}. The modification in TL glow curves of the nanomaterials irradiated by Li{sup 3+}, C{sup 6+}, and O{sup 7+} ion beams are essentially similar to those induced by {gamma}-ray irradiation. These glow curves have single peaks at around 427 K with a small variation in their positions by around {+-}3 K. The TL intensity of the ion beams irradiated nanomaterials is found to decease, while going from low to high atomic number (Z) ions (i.e., Li{sup 3+}{yields}O{sup 7+}). The TL response curve of the pellets irradiated by Li{sup 3+} ions is linear in the whole range of studied fluences. The curves for C{sup 6+} and O{sup 7+} irradiated samples are linear at lower fluences (1x10{sup 9}-1x10{sup 12} ion/cm{sup 2}) and then saturate at higher fluence. These results for the nanomaterials are much better than that of the corresponding microcrystalline samples irradiated with a Li{sup 3+} ion. The curves were linear up to the fluence 1x10{sup 11} ion/cm{sup 2} and then become sublinear at higher fluences. The TL efficiency values of K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}:Eu nanoparticles irradiated by 48 MeV Li{sup 3+}, 75 MeV C{sup 6+}, and 90 MeV O{sup 7+} ion beams have been measured relative to {gamma} rays of {sup 60}Co and are found to be 0.515, 0.069, and 0.019, respectively. This value for the Li{sup 3+} ion (0.515) is much higher than that of the corresponding microcrystalline material (0.0014). These superiorities for the nanomaterials make K{sub 2}Ca{sub 2}(SO{sub 4}){sub 3}:Eu nanophosphor a suitable candidate for detecting the doses of swift heavy ions. PL studies on the ion beams irradiated and

  9. Thermal expansion of NaTi/sub 2/(PO/sub 4/)/sub 3/ studied by Rietveld method from x-ray diffraction data

    SciTech Connect

    Rodrigo, J.L.; Carrasco, P.; Alamo, J. )

    1989-05-01

    Previous disagreement about the thermal expansion of the rhombohedral compound, NZP-type, NaTi/sub 2/(PO/sub 4/)/sub 3/ is clarified. It is shown that thermal stresses affect the thermal expansion, but they relax after some time of storage. Its anisotropic thermal expansion, has been calculate from high temperature X-ray diffraction, and it is linear in the range from room temperature up to 800{sup 0}C. The predictability of thermal expansion and the tailoring of the composition of NZP ceramics require checking whether the thermal effect on the rotations and distortions of the atomic polyhedra in this structure is the responsible for the high anisotropy in the thermal expansion. This effect has been determined experimentally by solving the chemical structure at five different temperatures, applying the Rietveld method to deconvolute the powder X-ray diffraction profiles.

  10. Temperature, Oxygen, and Soot-Volume-Fraction Measurements in a Turbulent C2H4sub>-Fueled Jet Flame

    SciTech Connect

    Kearney, Sean P.; Guildenbecher, Daniel Robert; Winters, Caroline; Farias, Paul Abraham; Grasser, Thomas W.; Hewson, John C.

    2015-09-01

    We present a detailed set of measurements from a piloted, sooting, turbulent C 2 H 4 sub>- fueled diffusion flame. Hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (CARS) is used to monitor temperature and oxygen, while laser-induced incandescence (LII) is applied for imaging of the soot volume fraction in the challenging jet-flame environment at Reynolds number, Re = 20,000. Single-laser shot results are used to map the mean and rms statistics, as well as probability densities. LII data from the soot-growth region of the flame are used to benchmark the soot source term for one-dimensional turbulence (ODT) modeling of this turbulent flame. The ODT code is then used to predict temperature and oxygen fluctuations higher in the soot oxidation region higher in the flame.

  11. Negative to positive magnetoresistance and magnetocaloric effect in Pr0.6Er0.4sub>Al2

    SciTech Connect

    Pathak, Arjun K.; Gschneidner, Jr., K. A.; Pecharsky, V. K.

    2014-10-13

    We report on the magnetic, magnetocaloric and magnetotransport properties of Pr0.6Er0.4sub>Al2. The title compound exhibits a large positive magnetoresistance (MR) for H ≥ 40 kOe and a small but non negligible negative MR for H ≤ 30 kOe. The maximum positive MR reaches 13% at H = 80 kOe. The magnetic entropy and adiabatic temperature changes as functions of temperature each show two anomalies: a broad dome-like maximum below 20 K and a relatively sharp peak at higher temperature. As a result, observed behaviors are unique among other binary and mixed lanthanide compounds.

  12. Calorimetric, spectroscopic and structural investigations of phase polymorphism in [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3}. Part I

    SciTech Connect

    Dolega, Diana; Mikuli, Edward; Inaba, Akira; Gorska, Natalia; Holderna-Natkaniec, Krystyna; Nitek, Wojciech

    2013-01-15

    Four crystalline phases of the coordination compound [Ru(NH{sub 3}){sub 6}](BF{sub 4}){sub 3} are identified by adiabatic calorimetry. Three phase transitions, one at T{sub C3}(IV{yields}III)=30.7 K, the second at T{sub C2}(III{yields}II)=91.7 K (both accompanied by comparable entropy changes 3.0 and 3.1 J K{sup -1} mol{sup -1}, respectively) and the third at T{sub C1}(II{yields}I)=241.6 K (accompanied by an entropy change of 8.1 J K{sup -1} mol{sup -1}) were discovered. X-ray single crystal diffraction (at 293 K) demonstrates that phase I is a highly dynamic disordered cubic phase (Fm3{sup Macron }m, No. 225) with two types of BF{sub 4}{sup -} anions differing in a degree of disorder. In phase II (at 170 K) the structure remains cubic (Ia3{sup Macron }, No. 206), with two different types of cations and four different types of anions. Splitting of certain IR bands connected with NH{sub 3} ligands at the observed phase transitions suggests a lowering of the symmetry of the [Ru(NH{sub 3}){sub 6}]{sup 3+} complex cation. Both NH{sub 3} ligands and BF{sub 4}{sup -} anions perform fast reorientations ({tau}{sub R} Almost-Equal-To 10{sup -12} s), which are significantly slowed down below the phase transition at T{sub C3}. {sup 1}H NMR studies led to estimate the values of the activation energy of NH{sub 3} ligands reorientation in the phases II and I as equal to {approx}8 kJ mol{sup -1}. In phase I the whole hexammineruthenium(III) cations reorientation as a tumbling process can be noticed. The activation energy value of this motion is {approx}24 kJ mol{sup -1}. {sup 19}F NMR studies give the values of the activation energy of BF{sub 4}{sup -} anions reorientation as {approx}6 kJ mol{sup -1}. Above the phase transition temperature half of BF{sub 4}{sup -} anions perform a tumbling motion with E{sub a} Almost-Equal-To 8 kJ mol{sup -1}. - Graphical abstract: A series of complementary methods, such as Adiabatic Calorimetry, Differential Scanning Calorimetry, Fourier

  13. One Dimensional(1D)-to-2D Crossover of Spin Correlations in the 3D Magnet ZnMn2O4sub>

    SciTech Connect

    Disseler, S. M.; Chen, Y.; Yeo, S.; Gasparovic, G.; Piccoli, P. M. B.; Schultz, A. J.; Qiu, Y.; Huang, Q.; Cheong, S. -W.; Ratcliff, W.

    2015-12-08

    In this paper we report on the intriguing evolution of the dynamical spin correlations of the frustrated spinel ZnMn2O4sub>. Inelastic neutron scattering and magnetization studies reveal that the dynamical correlations at high temperatures are 1D. At lower temperature, these dynamical correlations become 2D. Surprisingly, the dynamical correlations condense into a quasi 2D Ising-like ordered state, making this a rare observation of two dimensional order on the spinel lattice. Remarkably, 3D ordering is not observed down to temperatures as low as 300 mK. This unprecedented dimensional crossover stems from frustrated exchange couplings due to the huge Jahn-Teller distortions around Mn3+ ions on the spinel lattice.

  14. Generation of 30  fs pulses from a diode-pumped graphene mode-locked Yb:CaYAlO4sub> laser.

    PubMed

    Ma, Jie; Huang, Haitao; Ning, Kaijie; Xu, Xiaodong; Xie, Guoqiang; Qian, Liejia; Loh, Kian Ping; Tang, Dingyuan

    2016-03-01

    Stable 30 fs pulses centered at 1068 nm (less than 10 optical cycles) are demonstrated in a diode pumped Yb:CaYAlO4sub> laser by using high-quality chemical vapor deposited monolayer graphene as the saturable absorber. The mode-locked 8.43 optical-cycle pulses have a spectral bandwidth of ∼50  nm and a pulse repetition frequency of ∼113.5  MHz. To the best of our knowledge, this is the shortest pulse ever reported for graphene mode-locked lasers and mode-locked Yb-doped bulk lasers. Our experimental results demonstrate that graphene mode locking is a very promising practical technique for directly generating few-cycle optical pulses from a laser oscillator. PMID:26974072

  15. The behavior of thermal conductivity in the chaotic phase of [N(CH{sub 3}){sub 4}]{sub 2}ZnCl{sub 4} crystal

    SciTech Connect

    Sveleba, S. A. Karpa, I. V.; Kunyo, I. M.; Semotyuk, O. V.; Katerynchuk, I. M.; Phitsych, E. I.; Pankivskyi, Yu. I.

    2010-07-15

    A thermal investigation of the modulated structure dynamics at the transition between metastable states in the incommensurate phase of [N(CH{sub 3}){sub 4}]{sub 2}ZnCl{sub 4} crystal have been performed. It is established that the anomalous behavior of the thermal conductivity in the absence of a defect-density wave is due to the inelastic scattering of thermal phonons from critical phonons of the soft optical branch. In the presence of a defect-density wave, the anomalous increase in thermal conductivity is caused by the existence of a chaotic phase and is related to the contribution that soft optical phonons make to the heat transfer due to the increase in their group velocity.

  16. Enhanced ferromagnetic order in Sr{sub 4}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} featuring canted [MnO{sub 4}]{sub ∞} spin chains of mixed-valent Mn(III)/Mn(IV). Aliovalent substitution of the Sr{sub 4−x}Ln{sub x}Mn{sup III}{sub 2+x}Mn{sup IV}{sub 1−x}O{sub 3}(GeO{sub 4}){sub 3} solid-solution

    SciTech Connect

    West, J. Palmer; Sulejmanovic, Dino; Becht, Gregory; He, Jian; Hitchcock, Dale; Yan, Yonggao; Hwu, Shiou-Jyh

    2013-10-15

    Crystals of Sr{sub 4−x}Ln{sub x}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} (x=0; x∼0.15 for Ln=La, Pr, Nd, Sm. Eu, Gd, Dy; x∼0.3 for Ln=Gd) were isolated upon using high-temperature, solid-state methods in molten-salt media. These compounds are isostructural with the previously reported Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3} (Ln=La, Sm, Gd) series that contains the same [MnO{sub 4}]{sub ∞} spin chains. The synthesis of the Sr{sub 4}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} (x=0) phase was carried out by a double aliovalent substitution with respect to the Sr{sup 2+} and Ge{sup 4+} ions that replace Na{sup +}/Ln{sup 3+} and As{sup 5+} in Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3}, respectively. The title series contains mixed-valent Mn(III)/Mn(IV) and shows a limited range of solid solution, both of which were not observed in the previously reported Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3} series. To form the Sr{sub 4−x}Ln{sub x}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} solid solution, one of the Sr{sup 2+} sites, i.e., the original Ln-site in Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3}, is partially substituted by Ln{sup 3+} in a statistical disorder of Sr{sub 1−x}/Ln{sub x}. Initial magnetic investigations of selected derivatives reveal higher ferromagnetic ordering temperatures than those reported for the Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3} series, presumably attributed to a lesser degree of canting as a result of introducing non-Jahn–Teller Mn{sup 4+} ions. Also intriguing is the observation of multiple anomalies at low temperatures which appear to be of electronic origins. - Graphical abstract: Sr{sub 4−x}Ln{sub x}Mn(III){sub 2+x}Mn(IV){sub 1−x}O{sub 3}(GeO{sub 4}){sub 3}. Display Omitted - Highlights: • Double aliovalent substitution: Sr{sub 4}Mn{sub 3}O{sub 3}(GeO{sub 4}){sub 3} with respect to Na{sub 3}LnMn{sub 3}O{sub 3}(AsO{sub 4}){sub 3}. • Solid solution with respect to statistical disorder of Sr{sub 1

  17. Decoupling of the antiferromagnetic and insulating states in Tb-doped Sr2IrO4sub>

    SciTech Connect

    Wang, J. C.; Aswartham, S.; Ye, Feng; Terzic, J.; Zheng, H.; Haskel, Daniel; Chikara, Shalinee; Choi, Yong; Schlottmann, P.; Custelcean, Radu; Yuan, S. J.; Cao, G.

    2015-12-08

    Sr2IrO4sub> is a spin-orbit coupled insulator with an antiferromagnetic (AFM) transition at TN = 240 K. We report results of a comprehensive study of single-crystal Sr2Ir1-xTbxO4sub> (0≤x≤0.03). This study found that mere 3% (x=0.03) tetravalent Tb4+(4f7) substituting for Ir4+ (rather than Sr2+) completely suppresses the long-range collinear AFM transition but retains the insulating state, leading to a phase diagram featuring a decoupling of magnetic interactions and charge gap. The insulating state at x = 0.03 is characterized by an unusually large specific heat at low temperatures and an incommensurate magnetic state having magnetic peaks at (0.95, 0, 0) and (0, 0.95, 0) in the neutron diffraction, suggesting a spiral or spin density wave order. It is apparent that Tb doping effectively changes the relative strength of the SOI and the tetragonal CEF and enhances the Hund’s rule coupling that competes with the SOI, and destabilizes the AFM state. However, the disappearance of the AFM accompanies no metallic state chiefly because an energy level mismatch for the Ir and Tb sites weakens charge carrier hopping and renders a persistent insulating state. Furthermore, this work highlights an unconventional correlation between the AFM and insulating states in which the magnetic transition plays no critical role in the formation of the charge gap in the iridate.

  18. Complex conductance of ultrathin La2-xSrxCuO4sub> films and heterostructures

    SciTech Connect

    V. A. Gasparov; Bozovic, I.

    2015-10-23

    We used atomic-layer molecular beam epitaxy to synthesize bilayers of a cuprate metal (La1.55Sr0.45CuO4sub>) and a cuprate insulator (La2CuO4sub>), in which each layer is just one unit cells thick. We have studied the magnetic field and temperature dependence of the complex sheet conductance, σ(ω), of these films. Experiments have been carried out at frequencies between 2 and 50 MHz using the single-spiral coil technique. We found that: (i) the inductive response starts at ΔT = 3 K lower temperatures than Re σ(T), which in turn is characterized by a peak close to the transition, (ii) this shift is almost constant with magnetic field up to 14 mT; (iii) ΔT increases sharply up to 4 K at larger fields and becomes constant up to 8 T; (iv) the vortexdiffusion constant D(T) is not linear with T at low temperatures as in the case of free vortices, but is rather exponential due to pinning of vortex cores, and (v) the dynamic Berezinski–Kosterlitz–Thouless (BKT) transition temperature occurs at the point where Y=(lω/ξ+)2 = 1. As a result, our experimental results can be described well by the extended dynamic theory of the BKT transition and dynamics of bound vortex–antivortex pairs with short separation lengths.

  19. Self-powdering and nonlinear optical domain structures in ferroelastic beta'-Gd{sub 2}(MoO{sub 4}){sub 3} crystals formed in glass

    SciTech Connect

    Tsukada, Y.; Honma, T.; Komatsu, T.

    2009-08-15

    Ferroelastic beta'-Gd{sub 2}(MoO{sub 4}){sub 3}, (GMO), crystals are formed through the crystallization of 21.25Gd{sub 2}O{sub 3}-63.75MoO{sub 3}-15B{sub 2}O{sub 3} glass (mol%), and two scientific curious phenomena are observed. (1) GMO crystals formed in the crystallization break into small pieces with a triangular prism or pyramid shape having a length of 50-500 {mu}m spontaneously during the crystallizations in the inside of an electric furnace, not during the cooling in air after the crystallization. This phenomenon is called 'self-powdering phenomenon during crystallization' in this paper. (2) Each self-powdered GMO crystal grain shows a periodic domain structure with different refractive indices, and a spatially periodic second harmonic generation (SHG) depending on the domain structure is observed. It is proposed from polarized micro-Raman scattering spectra and the azimuthal dependence of second harmonic intensities that GMO crystals are oriented in each crystal grain and the orientation of (MoO{sub 4}){sup 2-} tetrahedra in GMO crystals changes periodically due to spontaneous strains in ferroelastic GMO crystals. - Graphical abstract: This figure shows the polarized optical photograph at room temperature for a particle (piece) obtained by a heat treatment of the glass at 590 deg. C for 2 h in an electric furnace in air. This particle was obtained through the self-powdering behavior in the crystallization of glass. The periodic domain structure is observed. Ferroelastic beta'-Gd{sub 2}(MoO{sub 4}){sub 3} crystals are formed in the particle, and second harmonic generations are detected, depending on the domain structure.

  20. Lithium diffusion in Li4sub>Ti5O12 at high temperatures

    SciTech Connect

    Vijayakumar, M.; Kerisit, Sebastien; Rosso, Kevin M.; Burton, Sarah D.; Sears, Jesse A.; Yang, Zhenguo; Graff, Gordon L.; Liu, Jun; Hu, Jianzhi

    2011-02-01

    Synthesis of the spinel lithium titanate Li4sub>Ti5O12 by an alkoxide-free sol–gel method is described. This method yields highly pure and crystalline Li4sub>Ti5O12 samples at relatively low temperature (850 °C) and via short thermal treatment (2 h). 6Li magic angle spinning nuclear magnetic resonance (MAS NMR) measurements on these samples were carried out at high magnetic field (21.1 T) and over a wide temperature range (295–680 K). The temperature dependence of the chemical shifts and integral intensities of the three 6Li resonances demonstrates the migration of lithium ions from the tetrahedral 8a to the octahedral 16c sites and the progressive phase transition from a spinel to a defective NaCl-type structure. This defective structure has an increased number of vacancies at the 8a site, which facilitate lithium diffusion through 16c → 8a → 16c pathways, hence providing an explanation for the reported increase in conductivity at high temperatures. Molecular dynamics simulations of the spinel oxides Li4+xTi5O12, with 0 ≤ x ≤ 3, were also performed with a potential shell model in the temperature range 300–700 K. Finally, the simulations support the conclusions drawn from the NMR measurements and show a significant timescale separation between lithium diffusion through 8a and 16c sites and that out of the 16d sites.

  1. Enhanced thermoelectric performance driven by high-temperature phase transition in the phase change material Ge4sub>SbTe5

    SciTech Connect

    Williams, Jared B.; Lara-Curzio, Edgar; Cakmak, Ercan; Watkins, Thomas R.; Morelli, Donald T.

    2015-05-15

    Phase change materials are identified for their ability to rapidly alternate between amorphous and crystalline phases and have large contrast in the optical/electrical properties of the respective phases. The materials are primarily used in memory storage applications, but recently they have also been identified as potential thermoelectric materials. Many of the phase change materials researched today can be found on the pseudo-binary (GeTe)1-x(Sb2Te3)x tie-line. While many compounds on this tie-line have been recognized as thermoelectric materials, here we focus on Ge4sub>SbTe5, a single phase compound just off of the (GeTe)1-x(Sb2Te3)x tie-line, that forms in a stable rocksalt crystal structure at room temperature. We find that stoichiometric and undoped Ge4sub>SbTe5 exhibits a thermal conductivity of ~1.2 W/m-K at high temperature and a large Seebeck coefficient of ~250 μV/K. The resistivity decreases dramatically at 623 K due to a structural phase transition which lends to a large enhancement in both thermoelectric power factor and thermoelectric figure of merit at 823 K. In a more general sense the research presents evidence that phase change materials can potentially provide a new route to highly efficient thermoelectric materials for power generation at high temperature.

  2. Crystal chemistry of anhydrous Li uranyl phosphates and arsenates. II. Tubular fragments and cation-cation interactions in the 3D framework structures of Li{sub 6}[(UO{sub 2}){sub 12}(PO{sub 4}){sub 8}(P{sub 4}O{sub 13})], Li{sub 5}[(UO{sub 2}){sub 13}(AsO{sub 4}){sub 9}(As{sub 2}O{sub 7})], Li[(UO{sub 2}){sub 4}(AsO{sub 4}){sub 3}] and Li{sub 3}[(UO{sub 2}){sub 7}(AsO{sub 4}){sub 5}O

    SciTech Connect

    Alekseev, Evgeny V.; Krivovichev, Sergey V.; Depmeier, Wulf

    2009-11-15

    Single crystals of the new compounds Li{sub 6}[(UO{sub 2}){sub 12}(PO{sub 4}){sub 8}(P{sub 4}O{sub 13})] (1), Li{sub 5}[(UO{sub 2}){sub 13}(AsO{sub 4}){sub 9}(As{sub 2}O{sub 7})] (2), Li[(UO{sub 2}){sub 4}(AsO{sub 4}){sub 3}] (3) and Li{sub 3}[(UO{sub 2}){sub 7}(AsO{sub 4}){sub 5}O)] (4) have been prepared using high-temperature solid state reactions. The crystal structures have been solved by direct methods: 1-monoclinic, C2/m, a=26.963(3) A, b=7.063(1) A, c=19.639(1) A, beta=126.890(4){sup o}, V=2991.2(6) A{sup 3}, Z=2, R{sub 1}=0.0357 for 3248 unique reflections with |F{sub 0}|>=4sigma{sub F}; 2-triclinic, P1-bar, a=7.1410(8) A, b=13.959(1) A, c=31.925(1) A, alpha=82.850(2){sup o}, beta=88.691(2){sup o}, gamma=79.774(3){sup o}, V=3107.4(4) A{sup 3}, Z=2, R{sub 1}=0.0722 for 9161 unique reflections with |F{sub 0}|>=4sigma{sub F}; 3-tetragonal, I4{sub 1}/amd, a=7.160(3) A, c=33.775(9) A, V=1732(1) A{sup 3}, Z=4, R{sub 1}=0.0356 for 318 unique reflections with |F{sub 0}|>=4sigma{sub F}; 4-tetragonal, P4-bar, a=7.2160(5) A, c=14.6540(7) A, V=763.04(8) A{sup 3}, Z=1, R{sub 1}=0.0423 for 1600 unique reflections with |F{sub 0}|>=4sigma{sub F}. Structures of all the phases under consideration are based on complex 3D frameworks consisting of different types of uranium polyhedra (UO{sub 6} and UO{sub 7}) and different types of tetrahedral TO{sub 4} anions (T=P or As): PO{sub 4} and P{sub 4}O{sub 13} in 1, AsO{sub 4} and As{sub 2}O{sub 7} in 2, and single AsO{sub 4} tetrahedra in 3 and 4. In the structures of 1 and 2, UO{sub 7} pentagonal bipyramids share edges to form (UO{sub 5}){sub i}nfinity chains extended along the b axis in 1 and along the a axis in 2. The chains are linked via single TO{sub 4} tetrahedra into tubular units with external diameters of 11 A in 1 and 11.5 A in 2, and internal diameters of 4.1 A in 1 and 4.5 A in 2. The channels accommodate Li{sup +} cations. The tubular units are linked into 3D frameworks by intertubular complexes. Structures of 3 and 4

  3. Synthesis of MoS2/g-C3N4sub> nanocomposites with enhanced visible-light photocatalytic activity for the removal of nitric oxide (NO).

    PubMed

    Wen, M Q; Xiong, T; Zang, Z G; Wei, W; Tang, X S; Dong, F

    2016-05-16

    Molybdenum disulfide and graphitic carbon nitride (MoS2-g-C3N4sub>) nanocomposites with visible-light induced photocatalytic activity were successfully synthesized by a facile ultrasonic dispersion method. The crystalline structure and morphology of the MoS2-g-C3N4sub> nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microcopy (TEM), high-resolution TEM (HRTEM) and scanning electron microscopy (SEM). The optical property of the as-prepared nanocomposites was studied by ultraviolet visible diffusion reflection (UV-vis) and photoluminescence(PL) spectrum. It could be observed from the TEM image that the MoS2 nanosheets and g-C3N4sub> nanoparticles were well combined together. Moreover, the photocatalytic activity of MoS2-g-C3N4sub> composites was evaluated by the removal of nitric oxide under visible light irradiation (>400nm). The experimental results demonstrated that the nanocomposites with the MoS2 content of 1.5 wt% exhibited optimal photocatalytic activity and the corresponding removal rate of NO achieved 51.67%, higher than that of pure g-C3N4sub> nanoparticles. A possible photocatalytic mechanism for the MoS2-g-C3N4sub> nanocomposites with enhanced photocatalytic activity could be ascribed to the hetero-structure of MoS2 and g-C3N4sub>. PMID:27409846

  4. Electronic Structure and Optical Properties of Cu2ZnGeSe4sub>. First-Principles Calculations and Vacuum-Ultraviolet Spectroscopic Ellipsometric Studies

    SciTech Connect

    Choi, Sukgeun; Park, Ji-Sang; Donohue, Andrea; Christensen, Steven T.; To, Bobby; Beall, Carolyn; Wei, Su-Huai; Repins, Ingid L.

    2015-11-19

    Cu2ZnGeSe4sub> is of interest for the development of next-generation thin-film photovoltaic technologies. To understand its electronic structure and related fundamental optical properties, we perform first-principles calculations for three structural variations: kesterite, stannite, and primitive-mixed CuAu phases. The calculated data are compared with the room-temperature dielectric functionϵ=ϵ1+iϵ2 spectrum of polycrystalline Cu2ZnGeSe4sub> determined by vacuum-ultraviolet spectroscopic ellipsometry in the photon-energy range of 0.7 to 9.0 eV. Ellipsometric data are modeled with the sum of eight Tauc-Lorentz oscillators, and the best-fit model yields the band-gap and Tauc-gap energies of 1.25 and 1.19 eV, respectively. A comparison of overall peak shapes and relative intensities between experimental spectra and the calculated ϵ data for three structural variations suggests that the sample may not have a pure (ordered) kesterite phase. We found that the complex refractive index N=n+ik, normal-incidence reflectivity R, and absorption coefficients α are calculated from the modeled ϵ spectrum, which are also compared with those of Cu2ZnSnSe4sub> . The spectral features for Cu2ZnGeSe4sub> appear to be weaker and broader than those for Cu2ZnSnSe4sub> , which is possibly due to more structural imperfections presented in Cu2ZnGeSe4sub> than Cu2ZnSnSe4sub> .

  5. Effect of the [Ba2BO3F]∞ Layer on the Band Gap: Synthesis, Characterization, and Theoretical Studies of BaZn2B2O6·nBa2BO3F (n = 0, 1, 2).

    PubMed

    Wu, Hongping; Su, Xin; Han, Shujuan; Yang, Zhihua; Pan, Shilie

    2016-05-16

    Two new zincoborate fluorides with the common formula BaZn2B2O6·nBa2BO3F (n = 1, 2) have been successfully synthesized for the relationship study between the band gaps and crystal structures in zinc-containing borate fluorides. Ba3Zn2B3O9F with n = 1 in the common formula belongs to the orthorhombic space group Pnma (No. 20), and Ba5Zn2B4O12F2 with n = 2 in the common formula crystallizes in the monoclinic space group C2/c (No. 62). They can both be seen as compounds with the n[Ba2BO3F]∞ (n = 1 or 2) layer inserted in the structure of BaZn2B2O6. UV-vis-near-IR diffuse-reflectance spectra show that the band gaps of BaZn2B2O6·nBa2BO3F (n = 0, 1, 2) gradually increase with more [Ba2BO3F]∞ layers inserted. The first-principles calculation indicates that the inserted n[Ba2BO3F]∞ layers play a positive effect in increasing the band gaps of zincoborate fluorides. Furthermore, the IR spectra, thermal behaviors, and refractive indices of these compounds are also studied. PMID:27119618

  6. TOXICITY AND CARCINOGENICITY STUDIES OF 4-METHYLIMIDAZOLE IN F344/N RATS AND B6C3F1 MICE

    PubMed Central

    Chan, P.C.; Hills, G. D; Kissling, G.E.; Nyska, A

    2008-01-01

    4-Methylimidazole (4MI) is used in the manufacture of pharmaceuticals, photographic chemicals, dyes and pigments, cleaning and agricultural chemicals, and rubber. It has been identified as a by-product of fermentation in foods and has been detected in mainstream and side stream tobacco smoke. 4MI was studied because of its high potential for human exposure. Groups of 50 male and 50 female F344/N rats were fed diets containing 0-, 625-, 1,250-, or 2,500-ppm 4MI (males) or 0-, 1,250-, 2,500-, or 5,000-ppm 4MI (females) for 106 weeks. Based on the food consumption the calculated average daily doses were approximately 30, 55, or 115 mg 4MI/kg body weight to males and 60, 120, or 250 mg 4MI/kg to females. Survival of all exposed groups of males and females was similar to that of the control groups. Mean body weights of males in the 1,250- and 2,500-ppm groups and females in the 2,500- and 5,000-ppm groups were less than those of the control groups throughout the study. Feed consumption by 5,000-ppm females was less than that by the controls. Clonic seizures, excitability, hyperactivity, and impaired gait were observed primarily in 2,500- and 5,000-ppm females. The incidence of mononuclear cell leukemia in the 5,000-ppm females was significantly greater than that in the controls. The incidences of hepatic histiocytosis, chronic inflammation, and focal fatty change were significantly increased in all exposed groups of male and female rats. The incidences of hepatocellular eosinophilic and mixed cell foci were significantly increased in 2,500-ppm males and 5,000-ppm females. Groups of 50 male and 50 female B6C3F1 mice were fed diets containing 0-, 312-, 625-, or 1,250-ppm 4MI for 106 weeks. Based on the food consumption the calculated average daily doses were approximately 40, 80, or 170 mg 4MI/kg body weight to males and females. Survival of all exposed groups of males and females was similar to that of the control groups. Mean body weights of males and females in the 1

  7. Insight into the Atomic Structure of High-Voltage Spinel LiNi0.5Mn1.5O4sub> Cathode Material in the First Cycle

    SciTech Connect

    Huang, Xuejie; Yu, Xiqian; Lin, Mingxiang; Ben, Liubin; Sun, Yang; Wang, Hao; Yang, Zhenzhong; Gu, Lin; Yang, Xiao -Qing; Zhao, Haofei; Yu, Richeng; Armand, Michel

    2014-12-22

    Application of high-voltage spinel LiNi0.5Mn1.5O4sub> cathode material is the closest and the most realistic approach to meeting the midterm goal of lithium-ion batteries for electric vehicles (EVs) and plug-in hybrid electric vehicles (HEVs). However, this application has been hampered by long-standing issues, such as capacity degradation and poor first-cycle Coulombic efficiency of LiNi0.5Mn1.5O4sub> cathode material. Although it is well-known that the structure of LiNi0.5Mn1.5O4sub> into which Li ions are reversibly intercalated plays a critical role in the above issues, performance degradation related to structural changes, particularly in the first cycle, are not fully understood. Here, we report detailed investigations of local atomic-level and average structure of LiNi0.5Mn1.5O4sub> during first cycle (3.5–4.9 V) at room temperature. We observed two types of local atomic-level migration of transition metals (TM) ions in the cathode of a well-prepared LiNi0.5Mn1.5O4sub>//Li half-cell during first charge via an aberration-corrected scanning transmission electron microscopy (STEM). Surface regions (~2 nm) of the cycled LiNi0.5Mn1.5O4sub> particles show migration of TM ions into tetrahedral Li sites to form a Mn3O4sub>-like structure. However, subsurface regions of the cycled particles exhibit migration of TM ions into empty octahedral sites to form a rocksalt-like structure. The migration of these TM ions are closely related to dissolution of Ni/Mn ions and building-up of charge transfer impedance, which contribute significantly to the capacity degradation and the poor first-cycle Coulombic efficiency of spinel LiNi0.5Mn1.5O4sub> cathode material. Accordingly, we provide suggestions of effective stabilization of LiNi0.5

  8. Crystal structure and thermal expansion of the low- and high-temperature forms of BaM{sup IV}(PO{sub 4}){sub 2} compounds (M=Ti, Zr, Hf and Sn)

    SciTech Connect

    Bregiroux, D.; Popa, K.; Jardin, R.; Raison, P.E.; Wallez, G.; Quarton, M.; Brunelli, M.; Ferrero, C.; Caciuffo, R.

    2009-05-15

    The crystal structure of beta-BaZr(PO{sub 4}){sub 2}, archetype of the high-temperature forms of BaM(PO{sub 4}){sub 2} phosphates (with M=Ti, Zr, Hf and Sn), has been solved ab initio by Rietveld analysis from synchrotron X-ray powder diffraction data. The phase transition appears as a topotactic modification of the monoclinic (S.G. C2/m) lamellar alpha-structure into a trigonal one (S.G. P3-barm1) through a simple mechanism involving the unfolding of the [Zr(PO{sub 4}){sub 2}]{sub n}{sup 2-} layers. The thermal expansion is very anisotropic (e.g., -4.14}){sub 2}) and quite different in the two forms, as a consequence of symmetry. It stems from a complex combination of several mechanisms, involving bridging oxygen rocking in M-O-P linkages, and 'bond thermal expansion'. - Graphical abstract: The layered high-temperature form of BaM(PO{sub 4}){sub 2}, only expands along the c-axis.

  9. Anti-GD2 antibody 3F8 and barley-derived (1 → 3),(1 → 4)-β-D-glucan

    PubMed Central

    Modak, Shakeel; Kushner, Brian H.; Kramer, Kim; Vickers, Andrew; Cheung, Irene Y.; Cheung, Nai-Kong V.

    2013-01-01

    β-glucans are complex, naturally-occurring polysaccharides that prime leukocyte dectin and complement receptor 3. Based on our preclinical findings, indicating that oral barley-derived (1 → 3),(1 → 4)-β-D-glucan (BG) synergizes with the murine anti-GD2 antibody 3F8 against neuroblastoma, we conducted a Phase I clinical study to evaluate the safety of this combinatorial regimen in patients affected by chemoresistant neuroblastoma. In this setting, four cohorts of six heavily pre-treated patients bearing recurrent or refractory advanced-stage neuroblastoma were treated with 3F8 plus BG. Each cycle consisted of intravenous 3F8 at a fixed dose of 10 mg/m2/day plus concurrent oral BG, dose-escalated from 10 to 80 mg/Kg/day, for 10 d. Patients who did not develop human anti-mouse antibodies could be treated for up to 4 cycles. Twenty-four patients completed 50 cycles of therapy. All patients completed at least one cycle and were evaluable for the assessment of toxicity and responses. The maximum tolerated dose of BG was not reached, but two patients developed dose-limiting toxicities. These individuals developed grade 4 thrombocytopenia after one cycle of BG at doses of 20 mg/Kg/day and 40 mg/Kg/day, respectively. Platelet counts recovered following the administration of idiopathic thrombocytopenic purpura therapy. There were no other toxicities of grade > 2. Eleven and 13 patients manifested stable and progressive disease, respectively. Thirteen out of 22 patients with pre-treatment positive 123I-MIBG scans demonstrated clinical improvement on semiquantitative scoring. Responses did not correlate with BG dose or with in vitro cytotoxicity. In summary, 3F8 plus BG is well tolerated and shows antineoplastic activity in recurrent or refractory advanced-stage neuroblastoma patients. Further clinical investigation of this novel combinatorial immunotherapeutic regimen is warranted. PMID:23802080

  10. Temperature-dependent framework–template interaction of |Na{sub 6}(H{sub 2}O){sub 8}|[ZnPO{sub 4}]{sub 6} sodalite

    SciTech Connect

    Robben, Lars Gesing, Thorsten M.

    2013-11-15

    The partial dehydration followed by the decomposition of sodium-zincophosphate-hydrosodalite caused by the total water loss was examined by temperature-dependent X-ray powder diffraction, Fourier transform infrared (FTIR) and Raman spectroscopy as well as thermogravimetry combined with difference thermoanalysis. The dehydration causing the decomposition of this sodalite could be described in a two step-process. Initially two water molecules per unit-cell were lost, changing the interaction between the zincophosphate framework and the remaining water molecules as well as sodium cations as non-framework constituents. In this stage a 3+3 coordination of water molecules and sodium cations in the sodalite cage is observed. Using the autocorrelation function (AC) for the evaluation of the temperature-dependent FTIR spectra of sodalites is reported here for the first time. Calculating the changes in the AC broadness, structural features could well be analyzed due to its correlation with respective structural parameters. Temperature dependent Raman data was used to give a band assignment of bands at Raman shifts below 300 cm{sup −1}. - Graphical abstract: The thermal decomposition of |Na{sub 6}(H{sub 2}O){sub 8}|[ZnPO{sub 4}]{sub 6} sodalite is a two-step process with an initial loss of two water molecules at 400 K, intermediately stabilizing the highly stressed framework. Further heating leads to a subsequent loss of the remaining six water molecules and a breakup of the sodalite framework. A beryllonite-type NaZnPO{sub 4} is the final product of this process. Display Omitted - Highlights: • The decomposition of |Na{sub 6}(H{sub 2}O){sub 8}|[ZnPO{sub 4}]{sub 6} sodalite is a two-step process. • Initial loss of two water molecule at 400 K stabilizes the sodalite (step 1). • Further heating leads to complete loss of water and structural breakdown. • Autocorrelation of temperature dependent FTIR-spectra gives structural information.

  11. Small 6q16.1 Deletions Encompassing POU3F2 Cause Susceptibility to Obesity and Variable Developmental Delay with Intellectual Disability.

    PubMed

    Kasher, Paul R; Schertz, Katherine E; Thomas, Megan; Jackson, Adam; Annunziata, Silvia; Ballesta-Martinez, María J; Campeau, Philippe M; Clayton, Peter E; Eaton, Jennifer L; Granata, Tiziana; Guillén-Navarro, Encarna; Hernando, Cristina; Laverriere, Caroline E; Liedén, Agne; Villa-Marcos, Olaya; McEntagart, Meriel; Nordgren, Ann; Pantaleoni, Chiara; Pebrel-Richard, Céline; Sarret, Catherine; Sciacca, Francesca L; Wright, Ronnie; Kerr, Bronwyn; Glasgow, Eric; Banka, Siddharth

    2016-02-01

    Genetic studies of intellectual disability and identification of monogenic causes of obesity in humans have made immense contribution toward the understanding of the brain and control of body mass. The leptin > melanocortin > SIM1 pathway is dysregulated in multiple monogenic human obesity syndromes but its downstream targets are still unknown. In ten individuals from six families, with overlapping 6q16.1 deletions, we describe a disorder of variable developmental delay, intellectual disability, and susceptibility to obesity and hyperphagia. The 6q16.1 deletions segregated with the phenotype in multiplex families and were shown to be de novo in four families, and there was dramatic phenotypic overlap among affected individuals who were independently ascertained without bias from clinical features. Analysis of the deletions revealed a ∼350 kb critical region on chromosome 6q16.1 that encompasses a gene for proneuronal transcription factor POU3F2, which is important for hypothalamic development and function. Using morpholino and mutant zebrafish models, we show that POU3F2 lies downstream of SIM1 and controls oxytocin expression in the hypothalamic neuroendocrine preoptic area. We show that this finding is consistent with the expression patterns of POU3F2 and related genes in the human brain. Our work helps to further delineate the neuro-endocrine control of energy balance/body mass and demonstrates that this molecular pathway is conserved across multiple species. PMID:26833329

  12. Small 6q16.1 Deletions Encompassing POU3F2 Cause Susceptibility to Obesity and Variable Developmental Delay with Intellectual Disability

    PubMed Central

    Kasher, Paul R.; Schertz, Katherine E.; Thomas, Megan; Jackson, Adam; Annunziata, Silvia; Ballesta-Martinez, María J.; Campeau, Philippe M.; Clayton, Peter E.; Eaton, Jennifer L.; Granata, Tiziana; Guillén-Navarro, Encarna; Hernando, Cristina; Laverriere, Caroline E.; Liedén, Agne; Villa-Marcos, Olaya; McEntagart, Meriel; Nordgren, Ann; Pantaleoni, Chiara; Pebrel-Richard, Céline; Sarret, Catherine; Sciacca, Francesca L.; Wright, Ronnie; Kerr, Bronwyn; Glasgow, Eric; Banka, Siddharth

    2016-01-01

    Genetic studies of intellectual disability and identification of monogenic causes of obesity in humans have made immense contribution toward the understanding of the brain and control of body mass. The leptin > melanocortin > SIM1 pathway is dysregulated in multiple monogenic human obesity syndromes but its downstream targets are still unknown. In ten individuals from six families, with overlapping 6q16.1 deletions, we describe a disorder of variable developmental delay, intellectual disability, and susceptibility to obesity and hyperphagia. The 6q16.1 deletions segregated with the phenotype in multiplex families and were shown to be de novo in four families, and there was dramatic phenotypic overlap among affected individuals who were independently ascertained without bias from clinical features. Analysis of the deletions revealed a ∼350 kb critical region on chromosome 6q16.1 that encompasses a gene for proneuronal transcription factor POU3F2, which is important for hypothalamic development and function. Using morpholino and mutant zebrafish models, we show that POU3F2 lies downstream of SIM1 and controls oxytocin expression in the hypothalamic neuroendocrine preoptic area. We show that this finding is consistent with the expression patterns of POU3F2 and related genes in the human brain. Our work helps to further delineate the neuro-endocrine control of energy balance/body mass and demonstrates that this molecular pathway is conserved across multiple species. PMID:26833329

  13. Experimental and theoretical methods to study structural phase transition mechanisms in K{sub 3}WO{sub 3}F{sub 3} oxyfluoride

    SciTech Connect

    Krylov, A.S.; Sofronova, S.N.; Kolesnikova, E.M.; Ivanov, Yu.N.; Sukhovsky, A.A.; Goryainov, S.V.; Ivanenko, A.A.; Shestakov, N.P.; Kocharova, A.G.; Vtyurin, A.N.

    2014-10-15

    The results of structural phase transitions mechanisms study in K{sub 3}WO{sub 3}F{sub 3}oxyfluoride are represented by different experimental and theoretical methods. The structural phase transition anomalies at T{sub 1}=452 K and T{sub 2}=414 K of Raman and IR spectra have been analyzed. Using vibrational spectroscopy methods, the NMR-experiment has been done to clarify the nature of found phase transitions: displacive types or order-disorder types. The model of “disordered” crystal was proposed, and the results of lattice dynamics calculation in frameworks of the generalized Gordon–Kim method of ordered (R3) and “disordered” crystals were compared. The high pressure phases were studied by the Raman technique too. - Graphical abstract: (1) Two possible configuration of octahedra. (2). All phases Raman lines of octahedra. (3) All phases IR lines of octahedra. (4) NMR spectra of all phases. - Highlights: • The results of study oxyfluoride K{sub 3}WO{sub 3}F{sub 3} are represented by Raman, IR, NMR technique. • The high pressure phases were studied by the Raman technique. • The anionic octahedra [WO{sub 3}F{sub 3}]{sup 3−} are not ordered below the both phase transitions. • The ferroelectric phase is realized due to the shift of atoms without F/O ordering. • Both of found phase transitions are close to the second order.

  14. Thalidomide enhances both primary and secondary host resistances to Listeria monocytogenes infection by a neutrophil-related mechanism in female B6C3F1 mice

    SciTech Connect

    Guo, Tai L. . E-mail: tlguo@hsc.vcu.edu; Chi, Rui P.; Karrow, Niel A.; Zhang, Ling X.; Pruett, Stephen B.; Germolec, Dori R.; White, Kimber L.

    2005-12-15

    Previously, we have reported that thalidomide can modulate the immune responses in female B6C3F1 mice. Furthermore, thalidomide immunomodulation increased primary host resistance to intravenously infected Listeria monocytogenes. The present study was intended to evaluate the mechanisms underlying the enhanced host resistance to L. monocytogenes by focusing on the neutrophils. Female B6C3F1 mice were treated intraperitoneally with thalidomide (100 mg/kg) for 15 days. Exposure to thalidomide increased the numbers of neutrophils in the spleens and livers of L. monocytogenes-infected mice when compared to the L. monocytogenes-infected control mice. Additionally, the percentage of neutrophils was also significantly increased after Thd treatment in L. monocytogenes-infected mice. Further studies using antibodies to deplete corresponding cells indicated that thalidomide-mediated increase in primary host resistance (both the moribundity and colony counts in the liver and spleen) to L. monocytogenes infection was due to its effect on neutrophils but not CD8{sup +} T cells or NK cells. Finally, Thd exposure also increased host resistance to secondary host resistance to L. monocytogenes infection, and depletion of neutrophils abolished the protective effect. In conclusion, thalidomide enhanced host resistance to both primary and secondary L. monocytogenes infections by a neutrophil-related mechanism in female B6C3F1 mice.

  15. Evaluation of Manganese Doped Ca5(PO4)3F as a Near Infrared (1-2 microns) Solid-State Laser Material

    NASA Technical Reports Server (NTRS)

    Turner, Matthew; Hoemmerich, Uwe; Loutts, George B.

    1998-01-01

    Tunable solid-state lasers are of enormous interest for applications including fundamental spectroscopy, remote sensing of the earth atmosphere, medical surgery, and optical communications. Efficient and widely tunable lasers have been developed for the 800-1100 nm region based on transition metal doped insulators like e.g. Ti:Sapphire. The development of transition metal lasers operating at longer wavelength, however, has been limited by the luminescence efficiency of existing materials. We are currently evaluating Mn doped Ca5(PO4)3F as a new solid-state laser material for the 1-2 micro-m region. Preliminary spectroscopic studies revealed that Mn:Ca5(PO4)3F exhibits an intense near infrared luminescence which extends from 1100-1300 nm. Based on lifetime measurements we estimated the luminescence quantum efficiency to be as high as 90 deg./0 at room temperature. The near infrared luminescence properties of Mn doped Ca5(PO4)3F and its potential for solid-state laser applications will be discussed in detail.

  16. Collisional quenching reaction rate coefficients of N2 (A3Σu+) by C2F6 and C3F8

    NASA Astrophysics Data System (ADS)

    Suzuki, Susumu; Kuboaki, Masaru; Itoh, Haruo

    2015-09-01

    The collisional quenching reaction rate coefficient of N2 (A3Σu+) by various air pollutant gases were determined from the measurement of the effective lifetime of N2 (A3Σu+) in pure N2 (5-nine) with a small amount of air pollutant gases as an admixture. Derivation of the rate coefficient was performed the waveform analysis of the transient ionization current after turning off the UV light in the Townsend discharge. In this paper, we report that the obtained collisional quenching reaction rate coefficients of N2 (A3Σu+) by C2F6 and C3F8 are (2.3 +/- 1.8) × 10-15 cm3/s and (1.6 +/- 0.8) × 10-14 cm3/s, respectively. Furthermore, we investigate the relationship between the rate coefficient and the mass number of their quenching molecular gases. Firstly, it is confirmed that the rate coefficient take large value with an increase in the mass number of the quenching gases. Secondly, if H atom is included in the gas molecules such as CH4, C2F6 and C3F8 the rate coefficient take large value, but if the molecules including F atom such as C2F6 and C3F8 instead of H atom in this study, more smaller values of the collisional quenching reaction rate coefficient are observed.

  17. Measurements of CCl3F, CCl2F2, CCl4, N2O and SF6 in the Northern Hemisphere stratosphere

    NASA Technical Reports Server (NTRS)

    Leifer, R.; Juzdan, R.

    1985-01-01

    An overview of the Department of Energy's High Altitude Sampling Program and some recent trace gas measurement results are presented. Analysis of whole air samples, collected in pressurized bottles, provides information on stratospheric inventories and distributions for CCl3F, CCl2F2, CCl4, N2O and SF6 in the Northern Hemisphere. Based on a linear regression analysis of the data the estimated mean Northern Hemisphere stratospheric concentration of each gas increased as follows: CCl3F changed from 54 to 142 p1/1 (4/74-11/83); CCl2F2 changed from 133 to 268 p1/1 (4/76-11/83); SF6 changed from 160 to 480 f1/1 (4/74-11/83); CC1, changed from 58 to 91 p1/1 (4/75-11/83); N2O changed from 246 to 261 n1/1 (4/76-11/83). The calculated mean Northern Hemisphere stratospheric concentrations of N2O, CCl3F, CCl2F2, and CCl4 after 1980 show larger than expected fluctuations with time. Recent volcanic activity may be a partial cause for these fluctuations through induced changes in stratospheric dynamical processes.

  18. New oxyfluoride glass with high fluorine content and laser patterning of nonlinear optical BaAlBO{sub 3}F{sub 2} single crystal line

    SciTech Connect

    Shionozaki, K.; Honma, T.; Komatsu, T.

    2012-11-01

    A new oxyfluoride glass of 50BaF{sub 2}-25Al{sub 2}O{sub 3}-25B{sub 2}O{sub 3} (mol. %) with a large fraction of fluorine, i.e., F/(F + O) = 0.4, was prepared using a conventional melt-quenching method in order to synthesize new glass-ceramics containing nonlinear optical oxyfluoride crystals. The refractive index at 632.8 nm and ultra-violet cutoff wavelength of the glass were 1.564 and {approx}200 nm, respectively. Eu{sup 3+} ions in the glass showed a high quantum yield of 88% in the photoluminescence spectrum in the visible region. BaAlBO{sub 3}F{sub 2} crystals (size: 50-100 nm) showing second harmonic generations were formed through the crystallization of the glass. Lines consisting of BaAlBO{sub 3}F{sub 2} crystals were patterned successfully on the glass surface by laser irradiations (Yb:YVO{sub 4} laser with a wavelength of 1080 nm, laser power of 1.1 W, scanning speed of 8 {mu}m/s). High resolution transmission electron microscope observations combined with a focused ion beam technique indicate that BaAlBO{sub 3}F{sub 2} crystals are highly oriented just like a single crystal. The present study proposes that the new oxyfluoride glass and glass-ceramics prepared have a high potential for optical device applications.

  19. Effects of quark family nonuniversality in SU(3){sub c} x SU(4){sub L} x U(1){sub X} models

    SciTech Connect

    Nisperuza, Jorge L.; Sanchez, Luis A.

    2009-08-01

    Flavor changing neutral currents arise in the SU(3){sub c} x SU(4){sub L} x U(1){sub X} extension of the standard model because anomaly cancellation among the fermion families requires one generation of quarks to transform differently from the other two under the gauge group. In the weak basis the distinction between quark families is meaningless. However, in the mass eigenstates basis, the Cabibbo-Kobayashi-Maskawa mixing matrix motivates us to classify left-handed quarks in families. In this sense there are, in principle, three different assignments of quark weak eigenstates into mass eigenstates. In this work, by using measurements at the Z pole, atomic parity violation data, and experimental input from neutral meson mixing, we examine two different models without exotic electric charges based on the 3-4-1 symmetry, and address the effects of quark family nonuniversality on the bounds on the mixing angle between two of the neutral currents present in the models and on the mass scales M{sub Z{sub 2}} and M{sub Z{sub 3}} of the new neutral gauge bosons predicted by the theory. The heaviest family of quarks must transform differently in order to keep lower bounds on M{sub Z{sub 2}} and M{sub Z{sub 3}} as low as possible without violating experimental constraints.

  20. Stable platinum nanoparticles on specific MgAl2O4sub> spinel facets at high temperatures in oxidizing atmospheres

    SciTech Connect

    Li, Wei-Zhen; Kovarik, Libor; Mei, Donghai; Liu, Jun; Wang, Yong; Peden, Charles H. F.

    2013-09-25

    The development of thermally stable, nanometer-sized precious metal-based catalysts remains a daunting challenge. Such materials, especially those based on the use of costly platinum metal, are essential and, to date, non-replaceable for a large number of industrially important catalytic processes. Here we report a well-defined cuboctahedral MgAl2O4sub> spinel support material that is capable of stabilizing platinum particles in the range of 1–3 nm on its relatively abundant {111} facets during extremely severe aging at 800 °C in air for 1 week. The aged catalysts retain platinum dispersions of 15.9% with catalytic activities for methanol oxidation being ~80% of that of fresh ones, whereas a conventional Pt/γ-Al2O3 catalyst is severely sintered and nearly inactive. Finally, we reveal the origin of the markedly superior ability of spinel {111} facets, resulting from strong interactions between spinel surface oxygens and epitaxial platinum {111} facets, inspiring the rational design of anti-sintering supported platinum group catalysts.

  1. Band alignment of atomic layer deposited (HfZrO{sub 4}){sub 1−x}(SiO{sub 2}){sub x} gate dielectrics on Si (100)

    SciTech Connect

    Heo, Sung; Tahir, Dahlang; Chung, Jae Gwan; Lee, Jae Cheol; Kim, KiHong; Lee, Junho; Lee, Hyung-Ik; Park, Gyeong Su; Oh, Suhk Kun; Kang, Hee Jae; Choi, Pyungho; Choi, Byoung-Deog

    2015-11-02

    The band alignment of atomic layer deposited (HfZrO{sub 4}){sub 1−x}(SiO{sub 2}){sub x} (x = 0, 0.10, 0.15, and 0.20) gate dielectric thin films grown on Si (100) was obtained by using X-ray photoelectron spectroscopy and reflection electron energy loss spectroscopy. The band gap, valence band offset, and conduction band offset values for HfZrO{sub 4} silicate increased from 5.4 eV to 5.8 eV, from 2.5 eV to 2.75 eV, and from 1.78 eV to 1.93 eV, respectively, as the mole fraction (x) of SiO{sub 2} increased from 0.1 to 0.2. This increase in the conduction band and valence band offsets, as a function of increasing SiO{sub 2} mole fraction, decreased the gate leakage current density. As a result, HfZrO{sub 4} silicate thin films were found to be better for advanced gate stack applications because they had adequate band gaps to ensure sufficient conduction band offsets and valence band offsets to Si.

  2. Structure and conductivity of the NASICON analog Na/sub 3/SC/sub 2/(PO/sub 4/)/sub 3/

    SciTech Connect

    Susman, S.; Delbecq, C.J.; Brun, T.O.; Prince, E.

    1982-01-01

    Neutron and x-ray diffraction data of Na/sub 3/SC/sub 2/(PO/sub 4/)/sub 3/ are presented that show the transition from an ordinary-conducting, high temperature phase to a still higher temperature, superionic conducting phase. There are at least four polymorphic modifications. At room temperature, the refined neutron diffraction data confirm the Cc space group reported by Efremov and Kalinin but with a = 16.0449(24), b = 8.9225(15), c = 9.0656(13)A, ..beta.. = 126.918(21), R/sub weighted pattern/ = 17.5%, and R/sub expected/ = 7%. Between 25/sup 0/C and 64/sup 0/C, a second polymorph appears. The structure is monoclinic but has not yet been refined. At 64/sup 0/C, a third polymorph C appears. It is rhombohedral R3c. Using hexagonal axes, a = 8.9273(2), c = 22.3668A, R/sub wp/ = 6.28% and R/sub e/ = 3.83% at 100/sup 0/C. At 166/sup 0/C, the high temperature polymorph D appears. It is the superconducting phase of NASICON(Sc). It, too, is rhombohedral R3c with a = 8.9274(1), c = 22.5493(6)A, R/sub wp/ = 5.81% and R/sub e/ = 3.87% at 225/sup 0/C. The diffraction data are correlated with ionic conductivity measurements as a function of temperature.

  3. New localized/delocalized emitting state of Eu2+ in orange-emitting hexagonal EuAl2O4sub>

    SciTech Connect

    Liu, Feng; Meltzer, Richard S.; Li, Xufan; Budai, John D.; Chen, Yu -Sheng; Pan, Zhengwei

    2014-11-18

    Eu2+-activated phosphors are being widely used in illuminations and displays. Some of these phosphors feature an extremely broad and red-shifted Eu2+ emission band; however, convincing explanation of this phenomenon is lacking. Here we report a new localized/delocalized emitting state of Eu2+ ions in a new hexagonal EuAl2O4sub> phosphor whose Eu2+ luminescence exhibits a very large bandwidth and an extremely large Stokes shift. At 77 K, two luminescent sites responsible for 550 nm and 645 nm broadband emissions are recognized, while at room temperature only the 645 nm emission band emits. The 645 nm emission exhibits a typical radiative lifetime of 1.27 μs and an unusually large Stokes shift of 0.92 eV. We identify the 645 nm emission as originating from a new type of emitting state whose composition is predominantly that of localized 4f65d character but which also contains a complementary component with delocalized conduction-band-like character. This investigation gives new insights into a unique type of Eu2+ luminescence in solids whose emission exhibits both a very large bandwidth and an extremely large Stokes shift.

  4. Anisotropic lattice thermal expansion of PbFeBO4sub>: A study by X-ray and neutron diffraction, Raman spectroscopy and DFT calculations

    SciTech Connect

    Murshed, M. Mangir; Mendive, Cecilia B.; Curti, Mariano; Nénert, Gwilherm; Kalita, Patricia E.; Lipinska, Kris; Cornelius, Andrew L.; Huq, Ashfia; Gesing, Thorsten M.

    2014-11-01

    We present the lattice thermal expansion of mullite-type PbFeBO4sub> in this study. The thermal expansion coefficients of the metric parameters were obtained from composite data collected from temperature-dependent neutron and X-ray powder diffraction between 10 K and 700 K. The volume thermal expansion was modeled using extended Grüneisen first-order approximation to the zero-pressure equation of state. The additive frame of the model includes harmonic, quasi-harmonic and intrinsic anharmonic potentials to describe the change of the internal energy as a function of temperature. Moreover, the unit-cell volume at zero-pressure and 0 K was optimized during the DFT simulations. Harmonic frequencies of the optical Raman modes at the Γ-point of the Brillouin zone at 0 K were also calculated by DFT, which help to assign and crosscheck the experimental frequencies. The low-temperature Raman spectra showed significant anomaly in the antiferromagnetic regions, leading to softening or hardening of some phonons. Selected modes were analyzed using a modified Klemens model. The shift of the frequencies and the broadening of the line-widths helped to understand the anharmonic vibrational behaviors of the PbO4, FeO6 and BO3 polyhedra as a function of temperature.

  5. X-ray absorption spectroscopy of LiBF 4sub> in propylene carbonate. A model lithium ion battery electrolyte

    SciTech Connect

    Smith, Jacob W.; Lam, Royce K.; Sheardy, Alex T.; Shih, Orion; Rizzuto, Anthony M.; Borodin, Oleg; Harris, Stephen J.; Prendergast, David; Saykally, Richard J.

    2014-08-20

    Since their introduction into the commercial marketplace in 1991, lithium ion batteries have become increasingly ubiquitous in portable technology. Nevertheless, improvements to existing battery technology are necessary to expand their utility for larger-scale applications, such as electric vehicles. Advances may be realized from improvements to the liquid electrolyte; however, current understanding of the liquid structure and properties remains incomplete. X-ray absorption spectroscopy of solutions of LiBF4sub> in propylene carbonate (PC), interpreted using first-principles electronic structure calculations within the eXcited electron and Core Hole (XCH) approximation, yields new insight into the solvation structure of the Li+ ion in this model electrolyte. By generating linear combinations of the computed spectra of Li+-associating and free PC molecules and comparing to the experimental spectrum, we find a Li+–solvent interaction number of 4.5. This result suggests that computational models of lithium ion battery electrolytes should move beyond tetrahedral coordination structures.

  6. Optical gain in capillary light guides filled with NaYF4sub>: Yb3+, Er3+ nanocolloids.

    PubMed

    Patel, Darayas N; Sarkisov, Sergey S; Darwish, Abdalla M; Ballato, John

    2016-09-01

    A capillary light guide optical amplifier using nanocolloids of Yb3+-Er3+ co-doped NaYF4sub> as a filler was successfully demonstrated. A 7-cm-long and 150-micron-inner-diameter capillary light guide was capable to amplify a pulsed optical signal at 1550 nm with a gain coefficient of 0.15 cm-1 at a pump power of 4 mW (980-nm wavelength). The nanocolloid gain medium was prepared by pulverizing the phosphor powder with a high-speed planetary ball mill. Ball milling of the powder in water produced nanoparticles with a size of approximately 130 nm that after drying were transferred to a liquid with high refractive index (1.551 at 1550 nm) required to maintain light confinement within the fused silica capillary light guide. The results show that RE-doped colloids of nanocrystals can be potentially used as liquid gain media fillers in capillary light guide lasers and amplifiers with high photostability and low toxicity. PMID:27607717

  7. Synthesis of nanostructured LiTi{sub 2}(PO{sub 4}){sub 3} powder by a Pechini-type polymerizable complex method

    SciTech Connect

    Mariappan, C.R.; Galven, C.; Crosnier-Lopez, M.-P.; Le Berre, F.; Bohnke, O. . E-mail: odile.bohnke@univ-lemans.fr

    2006-02-15

    The nanostructured NASICON-type LiTi{sub 2}(PO{sub 4}){sub 3} (LTP) material has been synthesized by Pechini-type polymerizable complex method. The use of water-soluble ammonium citratoperoxotitanate (IV) metal complex instead of alkoxides as precursor allows to prepare monophase material. Thermal analyses have been carried out on the powder precursor to check the weight loss and synthesis temperature. X-ray powder diffraction analysis (XRD) has been performed on the LTP powder obtained after heating the powder precursor over a temperature range from 550 to 1050 deg. C for 2 h. By varying the molar ratio of citric acid to metal ion (CA/Ti) and citric acid to ethylene glycol (CA/EG), the grain size of the LTP powder could be modified. The formation of small and well-crystalline grains, in the order of 50-125 nm in size, has been determined from the XRD patterns and confirmed by transmission electron microscopy.

  8. An air-stable Na3SbS4sub> superionic conductor prepared by a rapid and economic synthetic procedure

    SciTech Connect

    Wang, Hui; Chen, Yan; Hood, Zachary D.; Samuthira Pandian, Amaresh; Keum, Jong Kahk; An, Ke; Sahu, Gayatri; Liang, Chengdu

    2016-01-01

    All-solid-state sodium batteries, using abundant sodium resources and solid electrolyte, hold much promise for safe, low cost, large-scale energy storage. To realize the practical applications of all solid Na-ion batteries at ambient temperature, the solid electrolytes are required to have high ionic conductivity, chemical stability, and ideally, easy preparation. Ceramic electrolytes show higher ionic conductivity than polymers, but they often require extremely stringent synthesis conditions, either high sintering temperature above 1000 C or long-time, low-energy ball milling. Herein, we report a new synthesis route for Na3SbS4sub>, a novel Na superionic conductor that needs much lower processing temperature below 200 C and easy operation. This new solid electrolyte exhibits a remarkable ionic conductivity of 1.05 mS cm-1 at 25 °C and is chemically stable under ambient atmosphere. In conclusion, this synthesis process provides unique insight into the current state-of-the-art solid electrolyte preparation and opens new possibilities for the design of similar materials.

  9. Passive Q-switching of a Tm,Ho:KLu(WO4sub>)2 microchip laser by a Cr:ZnS saturable absorber.

    PubMed

    Serres, J M; Loiko, P; Mateos, X; Jambunathan, V; Yasukevich, A S; Yumashev, K V; Petrov, V; Griebner, U; Aguiló, M; Díaz, F

    2016-05-10

    A diode-pumped Tm,Ho:KLu(WO4sub>)2 microchip laser passively Q-switched with a Cr:ZnS saturable absorber generated an average output power of 131 mW at 2063.6 nm with a slope efficiency of 11% and a Q-switching conversion efficiency of 58%. The pulse characteristics were 14  ns/9  μJ at a pulse repetition frequency of 14.5 kHz. With higher modulation depth of the saturable absorber, 9  ns/10.4  μJ/8.2  kHz pulses were generated at 2061.1 nm, corresponding to a record peak power extracted from a passively Q-switched Tm,Ho laser of 1.15 kW. A theoretical model is presented, predicting the pulse energy and duration. The simulations are in good agreement with the experimental results. PMID:27168288

  10. Hydrothermal synthesis, structural and physico-chemical characterizations of two Nasicon phosphates: M{sub 0.50}{sup II}Ti{sub 2}(PO{sub 4}){sub 3} (M = Mn, Co)

    SciTech Connect

    Essehli, Rachid; Bali, Brahim El; Benmokhtar, S.; Fejfarova, Karla; Dusek, Michal

    2009-07-01

    The family of titanium Nasicon-phosphates of generic formula M{sub 0.5}{sup II}Ti{sub 2}(PO{sub 4}){sub 3} has been revisited using hydrothermal techniques. Two phases have been synthesized: Mn{sub 0.5}{sup II}Ti{sub 2}(PO{sub 4}){sub 3} (MnTiP) and Co{sub 0.5}{sup II}Ti{sub 2}(PO{sub 4}){sub 3} (CoTiP). Single crystal diffraction studies show that they exhibit two different structural types. Mn{sub 0.5}{sup II}Ti{sub 2}(PO{sub 4}){sub 3} phosphate crystallizes in the R-3 space group, with the cell parameters a = 8.51300(10) A and c = 21.0083(3) A (V = 1318.52(3) A{sup 3} and Z = 6). The Co{sub 0.5}{sup II}Ti{sub 2}(PO{sub 4}){sub 3} phosphate crystallizes in the R-3c space group, with a = 8.4608(9) A and c = 21.174(2) A (V = 1312.7(2) A{sup 3} and Z = 6). These two compounds are clearly related to the parent Nasicon-type rhombohedral structure, which can be described using [Ti{sub 2}(PO{sub 4}){sub 3}] framework composed of two [TiO{sub 6}] octahedral interlinked via three [PO{sub 4}] tetrahedra. {sup 31}P magic-angle spinning nuclear magnetic resonance (MAS-NMR) data are presented as supporting data. Curie-Weiss-type behavior is observed in the magnetic susceptibility. The phases are also characterized by IR spectroscopy and UV-visible.

  11. Synthesis and photoluminescence properties of Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} red phosphor for white light emitting diodes

    SciTech Connect

    Zhu, Ge; Ci, Zhipeng; Shi, Yurong; Wang, Yuhua

    2014-07-01

    Highlights: • A novel red phosphor Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} was synthesized and investigated firstly. • The structure and characteristic luminescence properties are discussed. • The excellent thermal stability was found and investigated. • It has good color saturation, the CIE is close to that of commercial Y{sub 2}O{sub 3}:Eu{sup 3+}. - Abstract: A series of Sm{sup 3+} doped Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14} red phosphors were successfully synthesized. X-ray diffraction analysis indicates that all the samples are single phased. The luminescence property is investigated in detail by measuring their photoluminescence excitation and emission spectra. Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} phosphors show strong absorption in 400–410 nm region, which is suitable for application in LEDs. When excited at 403 nm, Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} phosphor can emit red emission with CIE chromaticity coordinates (0.615, 0.384). The optimal doping concentration of Sm{sup 3+} doped Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14} is measured to be 0.02. The thermal quenching property is also measured and compared with the commercial red phosphor Y{sub 2}O{sub 3}:Eu{sup 3+} (Topstar, TXC-RIA). The results indicate Ca{sub 19}Mg{sub 2}(PO{sub 4}){sub 14}:Sm{sup 3+} phosphors have potential to serve as a red phosphor for white LEDs.

  12. Scintillation properties of Eu2+-doped KBa2I5 and K2BaI4sub>

    SciTech Connect

    Stand, L.; Zhuravleva, M.; Chakoumakos, Bryan C.; Johnson, J.; Lindsey, Adam; Melcher, Charles L.

    2015-09-25

    We report two new ternary metal halide scintillators, KBa2I5 and K2BaI4sub>, activated with divalent europium. Single crystal X-ray diffraction measurements confirmed that KBa2I5 has a monoclinic structure (P21/c) and that K2BaI4sub> has a rhombohedral structure (R3c). Differential scanning calorimetry showed singular melting and crystallization points, making these compounds viable candidates for melt growth. We grew 13 mm diameter single crystals of KBa2I5:Eu2+ and K2BaI4sub>:Eu2+ in evacuated quartz ampoules via the vertical Bridgman technique. The optimal Eu2+ concentration was 4% for KBa2I5 and 7% for K2BaI4sub>. The X-ray excited emissions at 444 nm for KBa2I5:Eu 4% and 448 nm for K2BaI4sub>:Eu 7% arise from the 5d-4f radiative transition in Eu2+. KBa2I5:Eu 4% has a light yield of 90,000 photons/MeV, with an energy resolution of 2.4% and K2BaI4sub>:Eu 7% has a light yield of 63,000 ph/MeV, with an energy resolution of 2.9% at 662 keV. Both crystals have an excellent proportional response to a wide range of gamma-ray energies.

  13. HERSCHEL /HIFI OBSERVATIONS OF A NEW INTERSTELLAR WATER MASER: THE 5{sub 32}-4{sub 41} TRANSITION AT 620.701 GHz

    SciTech Connect

    Neufeld, David A.; Wu, Yuanwei; Kraus, Alex; Menten, Karl M.; Tolls, Volker; Melnick, Gary J.; Nagy, Zsofia

    2013-05-20

    Using the Herschel Space Observatory's Heterodyne Instrument for the Far-Infrared, we have performed mapping observations of the 620.701 GHz 5{sub 32}-4{sub 41} transition of ortho-H{sub 2}O within a {approx}1.'5 Multiplication-Sign 1.'5 region encompassing the Kleinmann-Low nebula in Orion (Orion-KL), and pointed observations of that transition toward the Orion South condensation and the W49N region of high-mass star formation. Using the Effelsberg 100 m radio telescope, we obtained ancillary observations of the 22.23508 GHz 6{sub 16}-5{sub 23} water maser transition; in the case of Orion-KL, the 621 GHz and 22 GHz observations were carried out within 10 days of each other. The 621 GHz water line emission shows clear evidence for strong maser amplification in all three sources, exhibiting narrow ({approx}1 km s{sup -1} FWHM) emission features that are coincident (kinematically and/or spatially) with observed 22 GHz features. Moreover, in the case of W49N-for which observations were available at three epochs spanning a 2 yr period-the spectra exhibited variability. The observed 621 GHz/22 GHz line ratios are consistent with a maser pumping model in which the population inversions arise from the combined effects of collisional excitation and spontaneous radiative decay, and the inferred physical conditions can plausibly arise in gas heated by either dissociative or non-dissociative shocks. The collisional excitation model also predicts that the 22 GHz population inversion will be quenched at higher densities than that of the 621 GHz transition, providing a natural explanation for the observational fact that 22 GHz maser emission appears to be a necessary but insufficient condition for 621 GHz maser emission.

  14. Upregulation of estrogen receptor expression in the uterus of ovariectomized B6C3F1 mice and Ishikawa cells treated with bromoethane

    SciTech Connect

    Aoyama, Hiroaki; Couse, John F.; Hewitt, Sylvia C.; Haseman, Joseph K.; He, Hong; Zheng, Xiaolin; Majstoravich, Sonja; Korach, Kenneth S.; Dixon, D. . E-mail: dixon@niehs.nih.gov

    2005-12-15

    In a 2-year NTP bioassay, Bromoethane (BE) was found to induce endometrial neoplasms in the uterus of B6C3F1 mice [; ]. In women, hormonal influences, such as 'unopposed' estrogenic stimulus, have been implicated as important etiologic factors in uterine cancer. BE, however, does not affect the serum concentrations of sex hormones in female B6C3F1 mice [] and the mechanism of BE-induced uterine carcinogenesis still remains unclear. In the present study, we examined the estrogenic effects of BE on the uterus of ovariectomized B6C3F1 mice and on Ishikawa cells. Groups of 6 mice were given daily s.c. injections of 0, 100, 500 or 1000 mg BE/kg for 3 consecutive days. Mice treated with 17{beta}-estradiol served as positive controls. Mice were necropsied 24 h after the final injection, and uteri were weighed and examined histologically and immunohistochemically along with the vagina. Changes observed in the estrogen-treated mice included increased uterine weights, edema and inflammation of the endometrium, increased epithelial layers of the uterine and vaginal lumens and keratinization of the vaginal epithelium. In the BE-treated mice, no such changes occurred; however, immunohistochemical staining of the uterus revealed a significant increase in immunoexpression of the estrogen receptor alpha (ER{alpha}) in the two higher dose groups. Analysis of mRNA also showed slightly increased uterine ER{alpha} expression in these groups. Upregulated expression of ER{alpha} was confirmed in BE-treated Ishikawa cells, in which Western blotting analyses identified an intense signal at approximately 66 kDa, which is consistent with ER{alpha}. These data suggest that upregulated expression of ER{alpha} may be important in the induction of endometrial neoplasms in BE-treated mice.

  15. Enhancement of the Hepatotoxicity of chloroform in B6C3F1 mice by corn oil: implications for chloroform carcinogenesis

    SciTech Connect

    Bull, R.J.; Brown, J.M.; Meierhenry, E.A.; Jorgenson, T.A.; Robinson, M.; Stober, J.A.

    1986-11-01

    A recent study of the ability of chloroform in drinking water to produce cancer reported that male Osborne-Mendel rats developed renal tumors, but that female B6C3F1 mice failed to develop hepatocellular carcinomas. The results obtained in the male Osborne-Mendel rats were comparable to those observed in an earlier study sponsored by the National Cancer Institute (NCI). On the other hand, the lack of an increased incidence of hepatocellular carcinomas in female B6C3F1 mice was in sharp contrast to previously reported results. The doses of chloroform used were comparable to that which produced an 85% incidence in the NCI study. The authors have investigated the extent to which the vehicle might be responsible for the different results in these two studies by examining the differential effects of chloroform when it was administered by gavage using corn oil versus a 2% Emulphor suspension as the vehicle. Male and female B6C3F1 mice were administered chloroform at 60, 130, and 270 mg/kg per day for 90 days. At sacrifice, body and organ weights were measured, and blood was recovered to perform the following serum chemistry measurements (in order of priority): glutamate oxalacetate transaminase (SGOT), lactate dehydrogenase (LDH), blood urea nitrogen (BUN), and triglyceride (TG) levels. The liver was sectioned for histopathological examination. These data indicate that administration of chloroform by corn oil gavage results in more marked hepatotoxic effects than observed when it is provided in an aqueous suspension. A major difference between two recent carcinogenesis bioassays of chloroform in this same mouse strain was the vehicle used.

  16. Origin of Active Oxygen in a Ternary CuOx /Co3O4sub>–CeO 2 Catalyst for CO Oxidation

    SciTech Connect

    Liu, Zhigang; Wu, Zili; Peng, Xihong; Binder, Andrew; Chai, Songhai; Dai, Sheng

    2014-11-14

    In this paper, we have studied CO oxidation over a ternary CuOx/Co3O4sub>-CeO2 catalyst and employed the techniques of N2 adsorption/desporption, XRD, TPR, TEM, in situ DRIFTS and QMS (Quadrupole mass spectrometer) to explore the origin of active oxygen. DRIFTS-QMS results with labeled 18O2 indicate that the origin of active oxygens in CuOx/Co3O4sub>-CeO2 obeys a model, called as queue mechanism. Namely gas-phase molecular oxygens are dissociated to atomic oxygens and then incorporate in oxygen vacancies located at the interface of Co3O4sub>-CeO2 to form active crystalline oxygens, and these active oxygens diffuse to the CO-Cu+ sites thanks to the oxygen vacancy concentration magnitude and react with the activated CO to form CO2. This process, obeying a queue rule, provides active oxygens to form CO2 from gas-phase O2 via oxygen vacancies and crystalline oxygen at the interface of Co3O4sub>-CeO2.

  17. Syntheses and crystal structures of two novel alkaline uranyl chromates A{sub 2}(UO{sub 2})(CrO{sub 4}){sub 2} (A=Rb, Cs) with bidentate coordination mode of uranyl ions by chromate anions

    SciTech Connect

    Siidra, Oleg I.

    2012-03-15

    Single crystals of Cs{sub 2}(UO{sub 2})(CrO{sub 4}){sub 2} and Rb{sub 2}(UO{sub 2})(CrO{sub 4}){sub 2} were prepared by solid state reactions. The structures are based upon the [(UO{sub 2})(CrO{sub 4}){sub 2}]{sup 2-} chains. Within the chains, UrO{sub 5} pentagonal bipyramids (Ur=uranyl) form Ur{sub 2}O{sub 8} dimers, which are linked via CrO{sub 4} tetrahedra into one-dimensional chains. The CrO{sub 4} tetrahedra coordinate uranyl ions in both mono- and bidentate fashion, which is unusual for uranyl chromates. The bidentate coordination has a strong influence upon geometrical parameters of both U and Cr coordination polyhedra. The conformation of the chains in 1 and 2 is different due to the different size of the Cs{sup +} and Rb{sup +} cations. - Graphical abstract: Uranyl chromate chain with monodentate and bidentate coordination mode of uranyl cations by CrO{sub 4} tetrahedra in Cs{sub 2}(UO{sub 2})(CrO{sub 4}){sub 2}. Highlights: Black-Right-Pointing-Pointer Single crystals of novel uranyl chromates were prepared by solid state reactions. Black-Right-Pointing-Pointer The CrO{sub 4} tetrahedra coordinate uranyl ions in both mono- and bidentate fashion. Black-Right-Pointing-Pointer The bidentate coordination has a strong influence upon geometrical parameters.

  18. Polyselenide chemistry of indium and thallium in dimethylformamide, acetonitrile, and water. Syntheses, structures, and properties of the new complexes [In[sub 2](Se[sub 4])[sub 4](Se[sub 5])][sup 4[minus

    SciTech Connect

    Dhingra, S.S.; Kanatzidis, M.G. )

    1993-04-14

    The reaction of InCl[sub 3] with Na[sub 2]Se[sub 5] in dimethylformamide (DMF) in the presence of Ph[sub 4]PCl gave (Ph[sub 4]P)[sub 4][In[sub 2](Se[sub 4])[sub 4](Se[sub 5])] (I) in 75% yield. Under the same conditions, InCl[sub 3] reacted with Na[sub 2]Se[sub 5] in the presence of Pr[sub 4]NBr or Et[sub 4]NBr and afforded (Pr[sub 4]N)[sub 4][In[sub 2](Se[sub 4])[sub 4](Se[sub 5])] (II) in 65% yield and (Et[sub 4]N)[sub 4][In[sub 2](Se[sub 4])[sub 4](Se[sub 5])] (III) in 72% yield, respectively. Single-crystal X-ray diffraction studies show that (I), (II), and (III) contain the same anion, [In[sub 2](Se[sub 4])[sub 4](Se[sub 5])][sup 4[minus

  19. Fundamental Understanding of Methane-Carbon Dioxide-Water (CH4sub>-CO2-H2O) Interactions in Shale Nanopores under Reservoir Conditions. Quarterly Report.

    SciTech Connect

    Wang, Yifeng

    2015-10-27

    This project focuses on the systematic study of CH4sub>-CO2-H2O interactions in shale nanopores under high-pressure and high temperature reservoir conditions. The proposed work will help to develop new stimulation strategies to enable efficient resource recovery from fewer and less environmentally impactful wells.

  20. In situ determination of the spinel-post-spinel transition in Fe3O4sub> at high pressure and temperature by synchrotron X-ray diffraction

    SciTech Connect

    Schollenbruch, K; Woodland, A B; Frost, D J; Wang, Y; Sanehira, T; Langenhorst, F

    2011-08-10

    The position of the spinel-post-spinel phase transition in Fe3O4sub> has been determined in pressure-temperature space by in situ measurements using a multi-anvil press combined with white synchrotron radiation. Pressure measurement using the equation of state for MgO permitted pressure changes to be monitored at high temperature. The phase boundary was determined by the first appearance of diffraction peaks of the high-pressure polymorph (h-Fe3O4sub>) during pressure increase and the disappearance of these peaks on pressure decrease along several isotherms. We intersected the phase boundary over the temperature interval of 700-1400 ºC. The boundary is linear and nearly isobaric, with a slightly positive slope. Post-experiment investigation by TEM confirms that the reverse reaction from h-Fe 3O4sub> to magnetite during decompression leads to the formation of microtwins on the (311) plane in the newly formed magnetite. Observations made during the phase transition suggest that the transition has a pseudomartensitic character, explaining in part why magnetite persists at conditions well within the stability field of h-Fe3O4sub>, even at high temperatures. This study emphasizes the utility of studying phase transitions in situ at simultaneously high temperatures and pressures since the reaction kinetics may not be favorable at room temperature.

  1. Photoelectron Spectroscopy of Anions at 118.2 nm. Observation of High Electron Binding Energies in Superhalogens MCI4sub>- (M=Sc, Y, La)

    SciTech Connect

    Yang, Jie; Wang, Xue B.; Xing, Xiaopeng; Wang, Lai S.

    2008-05-29

    High energy photon is needed for photoelectron spectroscopy (PES) of anions with high electron binding energies, such as superhalogens and O-rich metal oxide clusters. The highest energy photon used for anion PES in the laboratory has been 157 nm (7.866 eV) from F2 eximer lasers. Here, we report an anion PES experiment using coherent vacuum ultraviolet radiation at 118.2 nm (10.488 eV) by tripling the third harmonic output (355 nm) of a Nd:YAG laser in a Xe/Ar cell. Our study focuses on a set of superhalogen species, MCI4sub>- (M=Sc, Y, La), which were expected to possess very high electron binding energies. While the 157 nm photon can only access the ground state detachment features for these species, more transitions to the excited states at binding energies higher than 8 eV are observed at 118.2 nm. The adiabatic detachment energies are shown to be, 6.84, 7.02, and 7.03 eV for ScCl4sub>-, YCl4sub>-, and LaCl4sub>- eV, respectively, whereas their corresponding vertical detachment energies are measured to be 7.14, 7.31, and 7.38 eV.

  2. Lasing in a Tm:Ho:Yb3Al5O12 crystal pumped into the 3H6 – 3F4 transition

    NASA Astrophysics Data System (ADS)

    Zavartsev, Yu D.; Zagumennyi, A. I.; Kalachev, Yu L.; Kutovoi, S. A.; Mikhailov, V. A.; Shcherbakov, I. A.

    2016-03-01

    A growth technology has been developed, and a Tm:Ho:Yb3Al5O12 laser crystal of high optical quality has been grown by Czochralski method. Its spectral and luminescent characteristics are studied. Lasing at a wavelength of 2100 nm is obtained under pumping into the absorption line on the 3H6 – 3F4 transition of the Tm3+ ion at a wavelength of 1678 nm. The slope and total (optical) efficiencies of the laser at an output power of up to 320 mW reach 41% and 30%, respectively.

  3. Effects of Heavy-Meson Exchange on the 1D2 and 3F3 N-N Partial Waves and the Question of Dibaryon Resonance

    NASA Astrophysics Data System (ADS)

    Kloet, W. M.; Silbar, Richard R.

    1980-09-01

    The 1D2 and 3F3 N-N amplitudes are studied in a unitary dynamical model. Parameterfree long- and medium-range forces are given by multiple pion exchange, allowing coupling to the NNπ channel. Short-range forces are mainly given by ρ and ω exchange, parametrized to fit known low-energy phase shifts for J>=2. Resulting Argand diagrams at medium energies show counter-clockwise loops, but far less dramatic than in the Hoshizaki phase-shift analysis. However, the results are similar to recent Arndt phase shifts.

  4. Serum Complement C3f and Fibrinopeptide A Are Potential Novel Diagnostic Biomarkers for Non-Alcoholic Fatty Liver Disease: A Study in Qingdao Twins

    PubMed Central

    Lin, Zhong-Hua; Cui, Ya-Zhou; Duan, Hai-Ping; Zhang, Mei; Xuan, Shi-Ying

    2014-01-01

    Aims To compare the different serum peptidome patterns between twins with and without non-alcoholic fatty liver disease (NAFLD) in order to help understand the pathogenesis of NAFLD and to identify potential diagnostic and therapeutic targets. Methods The peptidomics patterns of 63 cases with NAFLD were compared with their twin healthy controls in Qingdao, China. Peptides between 800Da and 3500Da were captured and concentrated using C18 reversed-phase columns, followed by MALDI-TOF mass spectrometry. The sequences of peptides associated with NAFLD were further identified by MALDI-TOF-TOF. Further validation studies were conducted. One hundred additional serum samples were detected by commercially available ELISA kits to calculate the concentrations of complement C3f and fibrinopeptide A, respectively. The differences of these two peptides in the NAFLD and control groups were compared using SPSS 17.0, respectively. Results Compared with healthy controls, eleven peaks (861.1, 877.07, 904.5, 1206.57, 1350.64, 1518.7, 1690.9, 1777.94, 2931.29, 3190.4, 3261.4) were up-regulated and 7 peaks (942.44, 1020.47, 1060.06, 1211.7, 1263.63, 1449.76, 2768.3) were down-regulated in the NAFLD group. Two peptides derived from complement C3f and fibrinopeptide A, respectively, had the highest ROC values indistinguishing NAFLD cases from their normal controls. In the validation group, the concentrations of complement C3f and fibrinopeptide A (1466.929±78.306 pg/ml, 4.189±0.326 ng/ml, respevtively) in NAFLD group was higher than in control group (complement C3f 1159.357±99.624 pg/ml, FPA 3.039±0.483 ng/ml; P<0.05). Conclusions In this study, we established apeptidomics pattern that could help distinguish NAFLD patients from their twin controls. The differently-regulated peptides identified in our study may be potential diagnostic markers or therapeutic targets for NAFLD. PMID:25250770

  5. All-solid-state blue laser pumped Pr:KY3F10-BBO ultraviolet laser at 305 nm All-solid-state blue laser

    NASA Astrophysics Data System (ADS)

    Dong, Y.; Li, S. T.; Zhang, X. H.

    2012-02-01

    An all-solid-state blue laser pumped Pr:KY3F10 (Pr:KYF) laser at 610 nm has been demonstrated. With an incident pump power of 2.6 W, the maximum output power was 213 mW. Moreover, intracavity second-harmonic generation (SHG) has also been achieved with a maximum ultraviolet power of 11 mW by using a β-BaB2O4 (BBO) nonlinear crystal. To the best of our knowledge, this is the first report on continuous-wave ultraviolet generation by intracavity frequency doubling Pr:KYF laser.

  6. Magnetic field, frequency and temperature dependence of complex conductance of ultrathin La1.65Sr0.45CuO4sub>/La2CuO4sub> films and the organic superconductors κ-(BEDT-TTF)2Cu[N(CN)2]Br

    SciTech Connect

    V. A. Gasparov; Bozovic, I.; He, Xi; Dubuis, G.; Pavuna, D.; Kushch, N. D.; Yagubskii, E. B.; Schlueter, J. A.

    2015-09-01

    In this study, we used atomic-layer molecular beam epitaxy (ALL-MBE) to synthesize bilayer films of a cuprate metal (La1.65Sr0.45CuO4sub>) and a cuprate insulator (La2CuO4sub>), in which interface superconductivity occurs in a layer that is just one-half unit cell thick. We have studied the magnetic field and temperature dependence of the complex sheet conductance, σ(ω), of these films, and compared them to κκ-(BEDT-TTF)2Cu[N(CN)2]Br single crystals. The magnetic field H was applied both parallel and perpendicular to the 2D conducting layers. Experiments have been carried out at frequencies between 23 kHz and 50 MHz using either two-coil mutual inductance technique, or the LC resonators with spiral or rectangular coils. The real and the imaginary parts of the mutual-inductance M(T,ω) between the coil and the sample were measured and converted to complex conductivity. For H perpendicular to the conducting layers, we observed almost identical behavior in both films and κ-Br single crystals: (i) the transition onset in the inductive response, Lk–1(T) occurs at a temperature lower by 2 K than in Re σ(T), (ii) this shift is almost constant with magnetic field up to 8 T; (iii) the vortex diffusion constant D(T) is exponential due to pinning of vortex cores. These results can be described by the extended dynamic theory of the Berezinski–Kosterlitz–Thouless (BKT) transition and dynamics of bound vortex–antivortex pairs with short separation lengths.

  7. NaLa(MoO{sub 4}){sub 2}: RE{sup 3+} (RE{sup 3+} = Eu{sup 3+}, Sm{sup 3+}, Er{sup 3+}/Yb{sup 3+}) microspheres: the synthesis and optical properties

    SciTech Connect

    Gao, Zhiyi; Wang, Zhiying; Fu, Linlin; Yang, Xingxing; Fu, Zuoling; Wu, Zhijian; Jeong, Jung Hyun

    2015-10-15

    The strong green upconversion (UC) emission were observed in various Er{sup 3+}, Yb{sup 3+} co-doped NaLa(MoO{sub 4}){sub 2} samples synthesized via a hydrothermal route. The UC intensity depends on the dopant concentration, and the optimal UC emission was obtained in NaLa(MoO{sub 4}){sub 2}: 0.02Er{sup 3+}/0.10 Yb{sup 3+}. - Highlights: • The NaLa(MoO{sub 4}){sub 2} microspheres doped with Eu{sup 3+}, Sm{sup 3+} and Er{sup 3+}/Yb{sup 3+} were synthesized by a hydrothermal method. • The effects of the EDTA in the initial solution crystal phase and morphology were studied. • The down-conversion luminescence properties of NaLa(MoO{sub 4}){sub 2}: RE{sup 3+} (RE{sup 3+} = Eu{sup 3+}, Sm{sup 3+}) were investigated. • The UC luminescence properties and mechanism of Er{sup 3+}/Yb{sup 3+} co-doped NaLa(MoO{sub 4}){sub 2} was discussed. - Abstract: NaLa(MoO{sub 4}){sub 2}: RE{sup 3+} (RE{sup 3+} = Eu{sup 3+}, Sm{sup 3+}) microspheres have been synthesized at 180 °C via a facile EDTA-mediated hydrothermal route. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), photoluminescence (PL) spectra were employed to characterize the samples. It was found that the amount of EDTA in the initial solution was responsible for crystal phase and shape determination. The effect of Eu{sup 3+} and Sm{sup 3+} doping concentrations on the luminescent intensity was also investigated in details. Furthermore, the up-conversion (UC) emissions have been observed in a series of Er{sup 3+}/Yb{sup 3+} co-doped NaLa(MoO{sub 4}){sub 2} samples. Concentration dependent studies revealed that the optimal composition was realized for a 2% Er{sup 3+} and 10% Yb{sup 3+}-doping concentration.

  8. A study of room-temperature LixMn1.5Ni0.5O4sub> solid solutions

    SciTech Connect

    Saravanan, Kuppan; Jarry, Angelique; Kostecki, Robert; Chen, Guoying

    2015-01-26

    Understanding the kinetic implication of solid-solution vs. biphasic reaction pathways is critical for the development of advanced intercalation electrode materials. Yet this has been a long-standing challenge in materials science due to the elusive metastable nature of solid solution phases. The present study reports the synthesis, isolation, and characterization of room-temperature LixMn1.5Ni0.5O4sub> solid solutions. In situ XRD studies performed on pristine and chemically-delithiated, micron-sized single crystals reveal the thermal behavior of LixMn1.5Ni0.5O4sub> (0 ≤ x ≤ 1) cathode material consisting of three cubic phases: LiMn1.5Ni0.5O4sub> (Phase I), Li0.5Mn1.5Ni0.5O4sub> (Phase II) and Mn1.5Ni0.5O4sub> (Phase III). A phase diagram capturing the structural changes as functions of both temperature and Li content was established. In conclusion, the work not only demonstrates the possibility of synthesizing alternative electrode materials that are metastable in nature, but also enables in-depth evaluation on the physical, electrochemical and kinetic properties of transient intermediate phases and their role in battery electrode performance.

  9. NMR relaxation study of the phase transitions and relaxation mechanisms of the alums MCr(SO{sub 4}){sub 2}.12H{sub 2}O (M=Rb and Cs) single crystals

    SciTech Connect

    Lim, Ae Ran; Paik, Younkee; Lim, Kye-Young

    2011-06-15

    The physical properties and phase transition mechanisms of MCr(SO{sub 4}){sub 2}.12H{sub 2}O (M=Rb and Cs) single crystals have been investigated. The phase transition temperatures, NMR spectra, and the spin-lattice relaxation times T{sub 1} of the {sup 87}Rb and {sup 133}Cs nuclei in the two crystals were determined using DSC and FT NMR spectroscopy. The resonance lines and relaxation times of the {sup 87}Rb and {sup 133}Cs nuclei undergo significant changes at the phase transition temperatures. The sudden changes in the splitting of the Rb and Cs resonance lines are attributed to changes in the local symmetry of their sites, and the changes in the temperature dependences of T{sub 1} are related to variations in the symmetry of the octahedra of water molecules surrounding Rb{sup +} and Cs{sup +}. We also compared these {sup 87}Rb and {sup 133}Cs NMR results with those obtained for the trivalent cations Cr and Al in MCr(SO{sub 4}){sub 2}.12H{sub 2}O and MAl(SO{sub 4}){sub 2}.12H{sub 2}O crystals. - Graphical Abstract: The physical properties and phase transition mechanisms of MCr(SO{sub 4}){sub 2}.12H{sub 2}O (M=Rb, Cs, and NH{sub 4}) single crystals have been investigated. Highlights: > The physical properties and phase transition mechanisms of MCr(SO{sub 4}){sub 2}.12H{sub 2}O (M=Rb and Cs) crystals {yields} The NMR spectra and the spin-lattice relaxation times T{sub 1} of the {sup 87}Rb and {sup 133}Cs nuclei in the two crystals {yields} The variations in the symmetry of the octahedra of water molecules surrounding Rb{sup +} and Cs{sup +}.

  10. Missense Mutation of POU Domain Class 3 Transcription Factor 3 in Pou3f3L423P Mice Causes Reduced Nephron Number and Impaired Development of the Thick Ascending Limb of the Loop of Henle.

    PubMed

    Rieger, Alexandra; Kemter, Elisabeth; Kumar, Sudhir; Popper, Bastian; Aigner, Bernhard; Wolf, Eckhard; Wanke, Rüdiger; Blutke, Andreas

    2016-01-01

    During nephrogenesis, POU domain class 3 transcription factor 3 (POU3F3 aka BRN1) is critically involved in development of distinct nephron segments, including the thick ascending limb of the loop of Henle (TAL). Deficiency of POU3F3 in knock-out mice leads to underdevelopment of the TAL, lack of differentiation of TAL cells, and perinatal death due to renal failure. Pou3f3L423P mutant mice, which were established in the Munich ENU Mouse Mutagenesis Project, carry a recessive point mutation in the homeobox domain of POU3F3. Homozygous Pou3f3L423P mutants are viable and fertile. The present study used functional, as well as qualitative and quantitative morphological analyses to characterize the renal phenotype of juvenile (12 days) and aged (60 weeks) homo- and heterozygous Pou3f3L423P mutant mice and age-matched wild-type controls. In both age groups, homozygous mutants vs. control mice displayed significantly smaller kidney volumes, decreased nephron numbers and mean glomerular volumes, smaller TAL volumes, as well as lower volume densities of the TAL in the kidney. No histological or ultrastructural lesions of TAL cells or glomerular cells were observed in homozygous mutant mice. Aged homozygous mutants displayed increased serum urea concentrations and reduced specific urine gravity, but no evidence of glomerular dysfunction. These results confirm the role of POU3F3 in development and function of the TAL and provide new evidence for its involvement in regulation of the nephron number in the kidney. Therefore, Pou3f3L423P mutant mice represent a valuable research model for further analyses of POU3F3 functions, or for nephrological studies examining the role of congenital low nephron numbers. PMID:27420727

  11. Missense Mutation of POU Domain Class 3 Transcription Factor 3 in Pou3f3L423P Mice Causes Reduced Nephron Number and Impaired Development of the Thick Ascending Limb of the Loop of Henle

    PubMed Central

    Rieger, Alexandra; Kemter, Elisabeth; Kumar, Sudhir; Popper, Bastian; Aigner, Bernhard; Wolf, Eckhard; Wanke, Rüdiger; Blutke, Andreas

    2016-01-01

    During nephrogenesis, POU domain class 3 transcription factor 3 (POU3F3 aka BRN1) is critically involved in development of distinct nephron segments, including the thick ascending limb of the loop of Henle (TAL). Deficiency of POU3F3 in knock-out mice leads to underdevelopment of the TAL, lack of differentiation of TAL cells, and perinatal death due to renal failure. Pou3f3L423P mutant mice, which were established in the Munich ENU Mouse Mutagenesis Project, carry a recessive point mutation in the homeobox domain of POU3F3. Homozygous Pou3f3L423P mutants are viable and fertile. The present study used functional, as well as qualitative and quantitative morphological analyses to characterize the renal phenotype of juvenile (12 days) and aged (60 weeks) homo- and heterozygous Pou3f3L423P mutant mice and age-matched wild-type controls. In both age groups, homozygous mutants vs. control mice displayed significantly smaller kidney volumes, decreased nephron numbers and mean glomerular volumes, smaller TAL volumes, as well as lower volume densities of the TAL in the kidney. No histological or ultrastructural lesions of TAL cells or glomerular cells were observed in homozygous mutant mice. Aged homozygous mutants displayed increased serum urea concentrations and reduced specific urine gravity, but no evidence of glomerular dysfunction. These results confirm the role of POU3F3 in development and function of the TAL and provide new evidence for its involvement in regulation of the nephron number in the kidney. Therefore, Pou3f3L423P mutant mice represent a valuable research model for further analyses of POU3F3 functions, or for nephrological studies examining the role of congenital low nephron numbers. PMID:27420727

  12. Properties and Crystallization Phenomena in Li2Si2O5–Ca5(PO4)3F and Li2Si2O5–Sr5(PO4)3F Glass–Ceramics Via Twofold Internal Crystallization

    PubMed Central

    Rampf, Markus; Dittmer, Marc; Ritzberger, Christian; Schweiger, Marcel; Höland, Wolfram

    2015-01-01

    The combination of specific mechanical, esthetic, and chemical properties is decisive for the application of materials in prosthodontics. Controlled twofold crystallization provides a powerful tool to produce special property combinations for glass–ceramic materials. The present study outlines the potential of precipitating Ca5(PO4)3F as well as Sr5(PO4)3F as minor crystal phases in Li2Si2O5 glass–ceramics. Base glasses with different contents of CaO/SrO, P2O5, and F− were prepared within the glasses of the SiO2–Li2O–K2O–CaO/SrO–Al2O3–P2O5–F system. Preliminary studies of nucleation by means of XRD and scanning electron microscopy (SEM) of the nucleated base glasses revealed X-ray amorphous phase separation phenomena. Qualitative and quantitative crystal phase analyses after crystallization were conducted using XRD in combination with Rietveld refinement. As a main result, a direct proportional relationship between the content of apatite-forming components in the base glasses and the content of apatite in the glass–ceramics was established. The microstructures of the glass–ceramics were investigated using SEM. Microstructural and mechanical properties were found to be dominated by Li2Si2O5 crystals and quite independent of the content of the apatite present in the glass–ceramics. Biaxial strengths of up to 540 MPa were detected. Ca5(PO4)3F and Sr5(PO4)3F influence the translucency of the glass–ceramics and, hence, help to precisely tailor the properties of Li2Si2O5 glass–ceramics. The authors conclude that the twofold crystallization of Li2Si2O5–Ca5(PO4)3F or Li2Si2O5–Sr5(PO4)3F glass–ceramics involves independent solid-state reactions, which can be controlled via the chemical composition of the base glasses. The influence of the minor apatite phase on the optical properties helps to achieve new combinations of features of the glass–ceramics and, hence, displays new potential for dental applications. PMID:26389112

  13. Pi-class glutathione-S-transferase-positive hepatocytes in aging B6C3F1 mice undergo apoptosis induced by dietary restriction.

    PubMed Central

    Muskhelishvili, L.; Turturro, A.; Hart, R. W.; James, S. J.

    1996-01-01

    Liver sections from aging ad libitum-fed and diet-restricted B6C3F1 male mice were evaluated immunohistochemically for pi-class glutathione S-transferase (GST-II). GST-II immunostaining of hepatocytes was diffuse and occurred in periportal regions of hepatic acinus, whereas perivenous areas were weakly stained or were stain-free. Expression of GST-II was significantly diminished in diet-restricted mice in all age groups and was associated with a marked decrease in liver tumor development. As most spontaneous liver tumors were GST-II positive, it can be speculated that they developed from GST-II positive initiated hepatocytes. To determine whether dietary restriction induces apoptosis in GST-II-positive hepatocytes, 24-month-old ad libitum-fed mice were introduced to 40% diet restriction. After 1 week of diet restriction, a decrease in GST-II expression was associated with a threefold increase in the frequency of apoptotic bodies as detected by terminal deoxynucleotidyl transferase-mediated d-UTP nick end labeling of DNA fragments. A two-step immunohistochemical procedure revealed that approximately 70% of apoptotic bodies were GST-II positive. These results suggest that spontaneous, potentially preneoplastic hepatocytes in tumor-prone B6C3F1 mice are eliminated by apoptosis with dietary restriction. Images Figure 1 PMID:8909248

  14. Reevaluation and Classification of Duodenal Lesions in B6C3F1 Mice and F344 Rats from 4 Studies of Hexavalent Chromium in Drinking Water.

    PubMed

    Cullen, John M; Ward, Jerrold M; Thompson, Chad M

    2016-02-01

    Thirteen-week and 2-year drinking water studies conducted by the National Toxicology Program (NTP) reported that hexavalent chromium (Cr(VI)) induced diffuse epithelial hyperplasia in the duodenum of B6C3F1 mice but not F344 rats. In the 2-year study, Cr(VI) exposure was additionally associated with duodenal adenomas and carcinomas in mice only. Subsequent 13-week Cr(VI) studies conducted by another group demonstrated non-neoplastic duodenal lesions in B6C3F1 mice similar to those of the NTP study as well as mild duodenal hyperplasia in F344 rats. Because intestinal lesions in mice are the basis for proposed safety standards for Cr(VI), and the histopathology data are relevant to the mode of action, consistency (an important Hill criterion for causality) was assessed across the aforementioned studies. Two veterinary pathologists applied uniform diagnostic criteria to the duodenal lesions in rats and mice from the 4 repeated-dose studies. Comparable non-neoplastic intestinal lesions were evident in mice and rats from all 4 studies; however, the incidence and severity of intestinal lesions were greater in mice than rats. These findings demonstrate consistency across studies and species and highlight the importance of standardized nomenclature for intestinal pathology. The differences in the severity of non-neoplastic lesions also likely contribute to the differential tumor response. PMID:26538584

  15. Structural, electronic and optical properties of novel carbonate fluorides ABCO3F (A=K, Rb, Cs; B=Ca, Sr)

    NASA Astrophysics Data System (ADS)

    Narsimha Rao, E.; Appalakondaiah, S.; Yedukondalu, N.; Vaitheeswaran, G.

    2014-04-01

    In the present study, we performed first principles calculations on the electronic and optical properties of layered alkali-alkaline earth carbonate fluorides which attract attention in the domain of nonlinear optics. The calculated lattice parameters and volumes with and without inclusion of van der Waals (vdW) correction methods to standard density functional methods were compared with experiments. We observed that vdW interactions are predominant in RbCaCO3F and CsCaCO3F as compared with other computed compounds. The calculated bulk modulus from single crystal elastic constants reveals that these materials are all relatively harder than the KH2PO4 (KDP) crystal. We also found that these materials are wide band gap insulators as obtained from Tran-Blaha modified Becke-Johnson potential. The linear optical properties such as dielectric function, refractive indices, birefringence and absorption spectra are presented. Finally, the calculated birefringence values indicate that these crystals could be promising for producing phase matching in the deep ultra-violet region.

  16. Radiosynthesis binding affinity and biodistribution of 3-[F-18]fluoro-N-({alpha},{alpha},{alpha}-trifluoro-m-tolyl)piperazine (FTFMPP), a radioligand for the Serotonin system

    SciTech Connect

    Mishani, E.; Cristel, M.E.; McCarthy, T.J.; Welch, M.J.

    1996-05-01

    The serotonin agonist N({alpha},{alpha},{alpha}-trifluoro-m-tolyl)piperazine (TFMPP) is a potent ligand for the serotonin system. Angelini and co-workers previously synthesized the c.a [F-18]TFMPP but the low specific activity (less than 0.2GBq/mmol) limited the application of this ligand. We have recently reported the formation of phenylpiperazines by a novel alumina supported bis-alkylation. We report the application of this method and biological evaluation of 3-[F-18]FTFMPP, a fluoro derivative of TFMPP. Reaction of [F-18]fluoride with 3,5-dinitrobenzotrifluoride gave the 3-[F-18]fluoro-5-nitrobenzotrifluoride in 70% yield. Reduction of the nitro group with Raney nickel and hydrazine hydrate gave the [F-18]aniline derivative in 70% yield. Finally, the phenylpiperazine was constructed by reaction of the [F-18]aniline derivative with bis-2-bromoethyl-N-(ethoxy carbonyl)amine on basic alumina (pH=9) as a solid support. After extraction of the activity with basic MeOH and HPLC purification on normal phase the final product- [F-18]FTFMPP was obtained in 50% yield (98% radiochemical purity). The specific activity of the final product was 100GBq/mmol. The binding affinity of FTFMPP to 5-HT receptor was determined (Ki = 80-100 nM) and found to be similar to the binding affinity of the TFMPP (160-180 nM). The biodistribution of [F-18]FTFMPP was performed in rats.

  17. Lesions of the urinary tract produced in Fischer 344 rats and B6C3F1 mice after chronic administration of 11-aminoundecanoic acid.

    PubMed

    Dunnick, J K; Huff, J E; Haseman, J K; Boorman, G A

    1983-01-01

    11-Aminoundecanoic acid, the monomer of nylon 11, was toxic to the urinary tract of both male and female B6C3F1 mice and Fischer 344 rats, when administered in the diet at 7500 or 15 000 ppm for 103-104 weeks. Dose-related effects included a decrease in mean body weight gain and in survival for male rats and for mice of each sex; increased incidence of hyperplasia of the transitional epithelium of the kidney in rats of each sex; increased incidence of calcification of the kidney in the female rats; increased incidence of hyperplasia of the urinary bladder in male rats; and mineralization of the kidney in mice of each sex. Transitional cell carcinomas of the urinary bladder of the male rat occurred with increased frequency in the high-dose group (control, 0/48; low-dose, 0/48; high-dose, 7/49). Additional evidence for carcinogenicity in the male rat was seen in the liver, where an increased frequency of neoplastic nodules was found in the treated animals (controls, 1/50; low-dose, 9/50; high-dose, 8/50). Therefore, under the conditions of these studies, 11-aminoundecanoic acid was carcinogenic for male Fischer 344 rats, inducing transitional cell carcinomas in the urinary bladder and neoplastic nodules in the liver. The test chemical was not demonstrated to be carcinogenic for female Fischer 344 rats or for B6C3F1 mice of either sex. PMID:6662302

  18. Reevaluation and Classification of Duodenal Lesions in B6C3F1 Mice and F344 Rats from 4 Studies of Hexavalent Chromium in Drinking Water

    PubMed Central

    Cullen, John M.; Ward, Jerrold M.

    2015-01-01

    Thirteen-week and 2-year drinking water studies conducted by the National Toxicology Program (NTP) reported that hexavalent chromium (Cr(VI)) induced diffuse epithelial hyperplasia in the duodenum of B6C3F1 mice but not F344 rats. In the 2-year study, Cr(VI) exposure was additionally associated with duodenal adenomas and carcinomas in mice only. Subsequent 13-week Cr(VI) studies conducted by another group demonstrated non-neoplastic duodenal lesions in B6C3F1 mice similar to those of the NTP study as well as mild duodenal hyperplasia in F344 rats. Because intestinal lesions in mice are the basis for proposed safety standards for Cr(VI), and the histopathology data are relevant to the mode of action, consistency (an important Hill criterion for causality) was assessed across the aforementioned studies. Two veterinary pathologists applied uniform diagnostic criteria to the duodenal lesions in rats and mice from the 4 repeated-dose studies. Comparable non-neoplastic intestinal lesions were evident in mice and rats from all 4 studies; however, the incidence and severity of intestinal lesions were greater in mice than rats. These findings demonstrate consistency across studies and species and highlight the importance of standardized nomenclature for intestinal pathology. The differences in the severity of non-neoplastic lesions also likely contribute to the differential tumor response. PMID:26538584

  19. Bacillus subtilis subsp. subtilis CBMDC3f with antimicrobial activity against Gram-positive foodborne pathogenic bacteria: UV-MALDI-TOF MS analysis of its bioactive compounds.

    PubMed

    Torres, M J; Petroselli, G; Daz, M; Erra-Balsells, R; Audisio, M C

    2015-06-01

    In this work a new Bacillus sp. strain, isolated from honey, was characterized phylogenetically. Its antibacterial activity against three relevant foodborne pathogenic bacteria was studied; the main bioactive metabolites were analyzed using ultraviolet matrix assisted laser desorption-ionization mass spectrometry (UV-MALDI MS). Bacillus CBMDC3f was phylogenetically characterized as Bacillus subtilis subsp. subtilis after rRNA analysis of the 16S subunit and the gyrA gene (access codes Genbank JX120508 and JX120516, respectively). Its antibacterial potential was evaluated against Listeria monocytogenes (9 strains), B. cereus (3 strains) and Staphylococcus aureus ATCC29213. Its cell suspension and cell-free supernatant (CFS) exerted significant anti-Listeria and anti-S. aureus activities, while the lipopeptides fraction (LF) also showed anti-B. cereus effect. The UV-MALDI-MS analysis revealed surfactin, iturin and fengycin in the CFS, whereas surfactin predominated in the LF. The CFS from CBMDC3f contained surfactin, iturin and fengycin with four, two and four homologues per family, respectively, whereas four surfactin, one iturin and one fengycin homologues were identified in the LF. For some surfactin homologues, their UV-MALDI-TOF/TOF (MS/MS; Laser Induced Decomposition method, LID) spectra were also obtained. Mass spectrometry analysis contributed with relevant information about the type of lipopeptides that Bacillus strains can synthesize. From our results, surfactin would be the main metabolite responsible for the antibacterial effect. PMID:25820813

  20. Micro-Raman and Micro-Infrared Spectroscopic Studies of Pb- and Au-Irradiated ZrSiO4sub>. Optical Properties, Structural Damage and Amorphization

    SciTech Connect

    Zhang, Ming; Boatner, Lynn A.; Salje, Ekhard; Ewing, Rodney C.; Daniel, Philippe; Weber, William J; Zhang, Yanwen; Farnan, Ian E.

    2008-04-22

    The optical properties of damaged, periodic and aperiodic domains created by Pb+ (280 keV) and Au4+ (10 MeV) implantation of zircon were studied using micro-infrared (IR) and micro-Raman spectroscopy. The Pb+ and Au4+ irradiations caused a dramatic decrease in the IR reflectivity similar to that observed for metamict natural zircon. The irradiation with 10 MeV Au4+ ions (to fluences of 1x1015 Au4+ ions/cm2) also results in the formation of an amorphized phase similar to that observed in metamict zircon. These results show that high-energy, heavy-ion irradiations provide a good simulation of the ballistic effects of the recoil nucleus of an alpha-decay event, and in both cases, the result is the creation of aperiodic domains. Additional IR and Raman features were recorded in samples irradiated with 280 keV Pb+ ions (to fluences of 1x1014 and 1x1015 Pb+ ions/cm2), indicating the formation of an irradiation-induced new phase(s). The frequencies of the features are consistent with lead silicates, ZrO2 and SiO2. The results show that spectral features of the Au4+ and Pb+ irradiated zircon are different from those of quenched ZrSiO4sub> melts, and the finding further confirms that the amorphous state produced by high-energy ion irradiations is structurally different from the glassy state that results from quenching a high temperature melt. In contrast to significant changes in the frequency and width of the Raman v3 band observed in metamict zircon, the Pb+ and Au4+ irradiations do not cause similar variations, indicating that the remaining zircon crystalline domains in irradiated samples have a crystalline structure with fewer defects than those of metamict zircon.

  1. Thermal expansion of phosphates with the NaZr{sub 2}(PO{sub 4}){sub 3} structure containing lanthanides and zirconium: R{sub 0.33}Zr{sub 2}(PO{sub 4}){sub 3} (R = Nd, Eu, Er) and Er{sub 0.33(1–x)} Zr{sub 0.25x}Zr{sub 2}(PO{sub 4}){sup 3}

    SciTech Connect

    Volgutov, V. Yu. Orlova, A. I.

    2015-09-15

    Phosphates R{sub 0.33}Zr{sub 2}(PO{sub 4}){sub 3} (R = Nd, Eu, or Er) and Er{sub 0.33(1–x)}Zr{sub 0.25}Zr{sub 2}(PO{sub 4}){sub 3} (x = 0, 0.25, 0.5, 0.75, 1.0) of the NaZr{sub 2}(PO{sub 4}){sub 3} family have been synthesized and investigated by high-temperature X-ray diffraction. The crystallochemical approach is used to obtain compounds with expected small and controllable thermal-expansion parameters. Phosphates with close-to-zero thermal-expansion parameters, including those with low thermal-expansion anisotropy, have been obtained: Nd{sub 0.33}Zr{sub 2}(PO{sub 4}){sub 3} with α{sub a} =–2.21 × 10{sup −6} °C{sup −1}, α{sub c} = 0.81 × 10{sup −6} °C{sup −1}, and Δα = 3.02 × 10{sup −6} °C{sup –1} and Er{sub 0.08}Zr{sub 0.19}Zr{sub 2}(PO{sub 4}){sub 3} with α{sub a} =–1.86 × 10{sup −6} °C{sup −1}, α{sub c} = 1.73 × 10{sup −6} °C{sup −1}, and Δα = 3.58 × 10{sup −6} °C{sup −1}.

  2. From {sub {infinity}}{sup 1}[(UO{sub 2}){sub 2}O(MoO{sub 4}){sub 4}]{sup 6-} to {sub {infinity}}{sup 1}[(UO{sub 2}){sub 2}(MoO{sub 4}){sub 3}(MoO{sub 5})]{sup 6-} infinite chains in A{sub 6}U{sub 2}Mo{sub 4}O{sub 21} (A=Na, K, Rb, Cs) compounds: Synthesis and crystal structure of Cs{sub 6}[(UO{sub 2}){sub 2}(MoO{sub 4}){sub 3}(MoO{sub 5})

    SciTech Connect

    Yagoubi, S.; Obbade, S.; Saad, S.; Abraham, F.

    2011-05-15

    A new caesium uranyl molybdate belonging to the M{sub 6}U{sub 2}Mo{sub 4}O{sub 21} family has been synthesized by solid-state reaction and its structure determined from single-crystal X-ray diffraction data. Contrary to the other alkali uranyl molybdates of this family (A=Na, K, Rb) where molybdenum atoms adopt only tetrahedral coordination and which can be formulated A{sub 6}[(UO{sub 2}){sub 2}O(MoO{sub 4}){sub 4}], the caesium compound Cs{sub 6}U{sub 2}Mo{sub 4}O{sub 21} should be written Cs{sub 6}[(UO{sub 2}){sub 2}(MoO{sub 4}){sub 3}(MoO{sub 5})] with molybdenum atoms in tetrahedral and square pyramidal environments. Cs{sub 6}[(UO{sub 2}){sub 2}(MoO{sub 4}){sub 3}(MoO{sub 5})] crystallizes in the triclinic symmetry with space group P1-bar and a=10.4275(14) A, b=15.075(2) A, c=17.806(2) A, {alpha}=70.72(1){sup o}, {beta}=80.38(1){sup o} and {gamma}=86.39(1){sup o}, V=2604.7(6) A{sup 3}, Z=4, {rho}{sub mes}=5.02(2) g/cm{sup 3} and {rho}{sub cal}=5.08(3) g/cm{sup 3}. A full-matrix least-squares refinement on the basis of F{sup 2} yielded R{sub 1}=0.0464 and wR{sub 2}=0.0950 for 596 parameters with 6964 independent reflections with I{>=}2{sigma}(I) collected on a BRUKER AXS diffractometer with Mo(K{alpha}) radiation and a CCD detector. The crystal structure of Cs compound is characterized by {sub {infinity}}{sup 1}[(UO{sub 2}){sub 2}(MoO{sub 4}){sub 3}(MoO{sub 5})]{sup 6-} parallels chains built from U{sub 2}O{sub 13} dimeric units, MoO{sub 4} tetrahedra and MoO{sub 5} square pyramids, whereas, Na, K and Rb compounds are characterized by {sub {infinity}}{sup 1}[(UO{sub 2}){sub 2}O(MoO{sub 4}){sub 4}]{sup 6-} parallel chains formulated simply of U{sub 2}O{sub 13} units and MoO{sub 4} tetrahedra. Infrared spectroscopy measurements using powdered samples synthesized by solid-state reaction, confirm the structural results. The thermal stability and the electrical conductivity are also studied. The four compounds decompose at low temperature (between 540 and 610 {sup o

  3. Dual Phase Li4sub>Ti5O12–TiO2 Nanowire Arrays As Integrated Anodes For High-rate Lithium-ion Batteries

    SciTech Connect

    Liao, Jin; Chabot, Victor; Gu, Meng; Wang, Chong M.; Xiao, Xingcheng; Chen, Zhongwei

    2014-08-19

    Lithium titanate (Li4sub>Ti5O12) is well known as a zero strain material inherently, which provides excellent long cycle stability as a negative electrode for lithium ion batteries. However, the low specific capacity (175 mA h g-1) limits it to power batteries although the low electrical conductivity is another intrinsic issue need to be solved. In this work, we developed a facile hydrothermal and ion-exchange route to synthesize the self-supported dual-phase Li4sub>Ti5O12–TiO2 nanowire arrays to further improve its capacity as well as rate capability. The ratio of Li4sub>Ti5O12 to TiO2 in the dual phase Li4sub>Ti5O12–TiO2 nanowire is around 2:1. The introduction of TiO2 into Li4sub>Ti5O12 increases the specific capacity. More importantly, by interface design, it creates a dual-phase nanostructure with high grain boundary density that facilitates both electron and Li ion transport. Compared with phase-pure nanowire Li4sub>Ti5O12 and TiO2 nanaowire arrays, the dual-phase nanowire electrode yielded superior rate capability (135.5 at 5 C, 129.4 at 10 C, 120.2 at 20 C and 115.5 mA h g-1 at 30 C). In-situ transmission electron microscope clearly shows the near zero deformation of the dual phase structure, which explains its excellent cycle stability.

  4. Selective Metal Exsolution in BaFe2-yMy(PO4sub>)2 (M = Co2+, Ni2+) Solid Solutions

    SciTech Connect

    Alcover, Ignacio Blazquez; Daviero-Minaud, Sylvie; David, Rénald; Filimonov, Dmitry; Huvé, Marielle; Attfield, J. Paul; Kabbour, Houria; Mentré, Olivier

    2015-08-19

    The 2D-Ising ferromagnetic phase BaFe2+2(PO4sub>)2 shows exsolution of up to one-third of its iron content (giving BaFe3+1.33(PO4sub>)2) under mild oxidation conditions, leading to nanosized Fe2O3 exsolved clusters. Here we have prepared BaFe2–yMy(PO4sub>)2 (M = Co2+, Ni2+; y = 0, 0.5, 1, 1.5) solid solutions to investigate the feasibility and selectivity of metal exsolution in these mixed metallic systems. For all the compounds, after 600 °C thermal treatment in air, a complete oxidation of Fe2+ to Fe3+ leaves stable M2+ ions, as verified by 57Fe Mössbauer spectroscopy, TGA, TEM, microprobe, and XANES. Furthermore, the size of the nanometric α-Fe2O3clusters coating the main phase strongly depends on the yM metal concentration. For M-rich phases the iron diffusion is hampered so that a significant fraction of superparamagnetic α-Fe2O3 particles (100% for BaFe0.5–xCo1.5(PO4sub>)2) was detected even at 78 K. Although Ni2+and Co2+ ions tend to block Fe diffusion, the crystal structure of BaFe0.67Co1(PO4sub>)2demonstrates a fully ordered rearrangement of Fe3+ and Co2+ ions after Fe exsolution. We found that the magnetic behaviors of the Fe-depleted materials are mostly dominated by antiferromagnetic exchange, while Co2+-rich compounds show metamagnetic transitions reminiscent of the BaCo2(PO4sub>)2 soft helicoidal magnet.

  5. [H{sub 3}N(CH{sub 2}){sub 4}NH{sub 3}]{sub 2}[Al{sub 4}(C{sub 2}O{sub 4})(H{sub 2}PO{sub 4}){sub 2}(PO{sub 4}){sub 4}].4[H{sub 2}O]: A new layered aluminum phosphate-oxalate

    SciTech Connect

    Peng Li; Li Jiyang; Yu Jihong . E-mail: jihong@mail.jlu.edu.cn; Li Guanghua; Fang Qianrong; Xu Ruren . E-mail: rrxu@mail.jlu.edu.cn

    2005-09-15

    A new layered inorganic-organic hybrid aluminum phosphate-oxalate [H{sub 3}N(CH{sub 2}){sub 4}NH{sub 3}]{sub 2}[Al{sub 4}(C{sub 2}O{sub 4})(H{sub 2}PO{sub 4}){sub 2}(PO{sub 4}){sub 4}].4[H{sub 2}O](AlPO-CJ25) has been synthesized hydrothermally, by using 1,4-diaminobutane (DAB) as structure-directing agent. The structure has been solved by single-crystal X-ray diffraction analysis and further characterized by IR, {sup 31}P MAS NMR, TG-DTA as well as compositional analyses. Crystal data: the triclinic space group P-1, a=8.0484(7) A, b=8.8608(8) A, c=13.2224(11) A, {alpha}=80.830(6) deg. , {beta}=74.965(5) deg. , {gamma}=78.782(6) deg. , Z=2, R {sub 1[} {sub I} {sub >2} {sub {sigma}} {sub (} {sub I} {sub )]}=0.0511 and wR {sub 2(alldata)}=0.1423. The alternation of AlO{sub 4} tetrahedra and PO{sub 4} tetrahedra gives rise to the four-membered corner-sharing chains, which are interconnected through AlO{sub 6} octahedra to form the layered structure with 4,6-net sheet. Interestingly, oxalate ions are bis-bidentately bonded by participating in the coordination of AlO{sub 6}, and bridging the adjacent AlO{sub 6} octahedra. The layers are held with each other through strong H-bondings between the terminal oxygens. The organic ammonium cations and water molecules are located in the large cavities between the interlayer regions. -- Graphical abstract: The alternation of AlO{sub 4} tetrahedra and PO{sub 4} tetrahedra gives rise to the four-membered corner-sharing chains, which are interconnected through AlO{sub 6} octahedra to form the layered structure with 4,6-net sheet. Oxalate ions are bis-bidentately boned by participating in the coordination of AlO{sub 6}, and bridging the adjacent AlO{sub 6} octahedra.

  6. The in vitro Biochemical Characterization of an HIV-1 Restriction Factor APOBEC3F: Importance of Loop 7 on Both CD1 and CD2 for DNA Binding and Deamination.

    PubMed

    Chen, Qihan; Xiao, Xiao; Wolfe, Aaron; Chen, Xiaojiang S

    2016-07-01

    APOBEC3F (A3F) is a member of the apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like (APOBEC) family of proteins that can deaminate cytosine (C) to uracil (U) on nucleic acids. A3F is one of the four APOBEC members with two Zn-coordinated homologous cytosine deaminase (CD) domains, with the others being A3G, A3D, and A3B. Here we report the in vitro characterization of DNA binding and deaminase activities using purified wild-type and various mutant proteins of A3F from an Escherichia coli expression system. We show that even though CD1 is catalytically inactive and CD2 is the active deaminase domain, presence of CD1 on the N-terminus of CD2 enhances the deaminase activity by over an order of magnitude. This enhancement of CD2 catalytic activity is mainly through the increase of substrate single-stranded (ss) DNA binding by the N-terminal CD1 domain. We further show that the loop 7 of both CD1 and CD2 of A3F plays an important role for ssDNA binding for each individual domain, as well as for the deaminase activity of CD2 domain in the full-length A3F. PMID:27063502

  7. Na[subscript 1.5]Ag[subscript 1.5]MO[subscript 3]F[subscript 3] (M = Mo, W): An Ordered Oxyfluoride Derivative of the LiNbO[subscript 3] Structure

    SciTech Connect

    Fry, Allyson M.; Seibel, II, Harry A.; Lokuhewa, Indunil N.; Woodward, Patrick M.

    2012-04-02

    Na{sub 1.5}Ag{sub 1.5}MoO{sub 3}F{sub 3} and Na{sub 1.5}Ag{sub 1.5}WO{sub 3}F{sub 3} have been synthesized by solid state reactions and structurally characterized using synchrotron X-ray and neutron powder diffraction. Unlike the vast majority of salts containing [MO{sub 3}F{sub 3}]{sup 3-} anions (M = Mo, W) the oxyfluoride groups in Na{sub 1.5}Ag{sub 1.5}MoO{sub 3}F{sub 3} and Na{sub 1.5}Ag{sub 1.5}WO{sub 3}F{sub 3} are orientationally ordered, so that the Na{sup +} ions are coordinated by fluorine and the Ag{sup +} ions by oxygen. The resulting structure type, which has not previously been reported, is related to the LiNbO{sub 3} structure, but the combination of Na/Ag ordering and orientational ordering of the [MO{sub 3}F{sub 3}]{sup 3-} anions produces a supercell that doubles the c-axis and changes the space group symmetry from R3 to R{bar 3}. The use of hard (Na{sup +}) and soft (Ag{sup +}) cations to direct the orientational ordering of polar oxyfluoride building units provides a new approach to the design of polar materials.

  8. Frequency stabilization of an Er-doped fiber laser with a collinear 2f-to-3f self-referencing interferometer

    SciTech Connect

    Hitachi, K. Ishizawa, A.; Mashiko, H.; Sogawa, T.; Gotoh, H.; Tadanaga, O.; Nishikawa, T.

    2015-06-08

    We report the stabilization of the carrier-envelope offset (CEO) frequency of an Er-doped fiber laser with a collinear 2f-to-3f self-referencing interferometer. The interferometer is implemented by a dual-pitch periodically poled lithium niobate ridge waveguide with two different quasi-phase matching pitch sizes. We obtain a 52-dB signal-to-noise ratio in the 100-kHz resolution bandwidth of a heterodyne beat signal, which is sufficient for frequency stabilization. We also demonstrate that the collinear geometry is robust against environmental perturbation by comparing in-loop and out-of-loop Allan deviations when the in-loop CEO frequency is stabilized with a phase-locked loop circuit.

  9. Theoretical temperature-dependent branching ratios and laser thresholds of the 3F4 to 3H6 levels of Tm(3+) in ten garnets

    NASA Technical Reports Server (NTRS)

    Filer, Elizabeth D.; Barnes, Norman P.; Morrison, Clyde A.

    1991-01-01

    The calculated energy levels, the branching ratios, and the estimated thresholds for thulium operating on the 3F4 to 3H6 transitions are reported. Garnet materials with the general formula A3B2C3O12 are evaluated. Calculations are performed for the A side under the assumption of D2 symmetry. X-ray data available in the literature are used to evaluate the crystal-field components, A sub nm. Even-n components are employed to calculate the crystal-field splittings within the manifold. Thermal occupation factors are determined in a straightforward manner using a Boltzmann distribution for the respective manifolds. Odd-n components are applied to calculate the transition probabilities for electric field transitions. It is determined that the magnetic dipole contributions to the transition probability are comparable to the electric dipole contributions in some cases. Thresholds as a function of the density of thulium atoms are calculated.

  10. Frequency stabilization of an Er-doped fiber laser with a collinear 2f-to-3f self-referencing interferometer

    NASA Astrophysics Data System (ADS)

    Hitachi, K.; Ishizawa, A.; Tadanaga, O.; Nishikawa, T.; Mashiko, H.; Sogawa, T.; Gotoh, H.

    2015-06-01

    We report the stabilization of the carrier-envelope offset (CEO) frequency of an Er-doped fiber laser with a collinear 2f-to-3f self-referencing interferometer. The interferometer is implemented by a dual-pitch periodically poled lithium niobate ridge waveguide with two different quasi-phase matching pitch sizes. We obtain a 52-dB signal-to-noise ratio in the 100-kHz resolution bandwidth of a heterodyne beat signal, which is sufficient for frequency stabilization. We also demonstrate that the collinear geometry is robust against environmental perturbation by comparing in-loop and out-of-loop Allan deviations when the in-loop CEO frequency is stabilized with a phase-locked loop circuit.

  11. Spectroscopic properties of trivalent chromium in the fluoride garnet Na/sub 3/In/sub 2/Li/sub 3/F/sub 12/

    SciTech Connect

    de Viry, D.; Denis, J.P.; Blanzat, B.; Grannec, J.

    1987-11-01

    The spectroscopic properties of the fluoride garnet Na/sub 3/In/sub 2/Li/sub 3/F/sub 12/:Cr/sup 3 +/, relevant for tunable laser emission, are investigated. In view of the excitation spectrum the /sup 4/T/sub 2/ band can be assigned at 630 nm and the /sup 4/T/sub 1/ band at 436 nm. The emission spectrum, corresponding to the /sup 4/T/sub 2/-/sup 4/A/sub 2/ transition, is centered at 770 nm at 300 K with a bandwidth of 130 nm. The Tanabe-Sugano parameter Dq/B is 2.1. The /sup 4/T/sub 2/ level lifetime is long even at 300 K (320 ..mu..sec). These properties favor the chromium-doped fluoride garnet as a promising material for a room-temperature, tunable, and Q-switchable laser.

  12. Generation of high power 200 mW laser radiation at 177.3 nm in KBe2BO3F2 crystal

    NASA Astrophysics Data System (ADS)

    Xu, Bo; Liu, Lijuan; Wang, Xiaoyang; Chen, Chuangtian; Zhang, Xin; Lin, Shujie

    2015-12-01

    With a newly developed diffusion-bonded KBe2BO3F2 prism-coupled device and by temperature stabilization of the device, we have achieved an average power of 200 mW at 177.3 nm through the sixth harmonic generation of a picosecond Nd:YAG laser. This is the highest power at 177.3 nm ever generated in any nonlinear optical crystals. A stable average power of 72.2 mW at 177.3 nm was also obtained with a small fluctuation of 3.2 % over a period of 30 min. Moreover, both the angle and temperature acceptances for the 177.3 nm generation were reported for the first time in this paper.

  13. Benzene metabolite levels in blood and bone marrow of B6C3F{sub 1} mice after low-level exposure

    SciTech Connect

    Bechtold, W.E.; Strunk, M.R.; Thornton-Manning, J.R.

    1995-12-01

    Studies at the Inhalation Toxicology Research Institute (ITRI) have explored the species-specific uptake and metabolism of benzene. Results have shown that metabolism is dependent on both dose and route of administration. Of particular interest were shifts in the major metabolic pathways as a function of exposure concentration. In these studies, B6C3F{sub 1} mice were exposed to increasing levels of benzene by either gavage or inhalation. As benzene internal dose increased, the relative amounts of muconic acid and hydroquinone decreased. In contrast, the relative amount of catechol increased with increasing exposure. These results show that the relative levels of toxic metabolites are a function of exposure level. Based on these results and assuming a linear relationship between exposure concentration and levels of bone marrow metabolites, it would be difficult to detect an elevation of any phenolic metabolites above background after occupational exposures to the OSHA Permissible Exposure Limit of 1 ppm benzene.

  14. Near-infrared-to-near-infrared down-shifting and upconversion luminescence of KY3F10 with single dopant of Nd3+ ion

    NASA Astrophysics Data System (ADS)

    Lin, Huihong; Yu, Ting; Tsang, Ming-Kiu; Bai, Gongxun; Zhang, Qinyuan; Hao, Jianhua

    2016-01-01

    We have studied the structural and near-infrared (NIR) luminescent properties of KY3F10 phosphors, singly doped with Nd3+ serving as both sensitizer and activator. With a single laser diode at the wavelength of 808 nm as a pump source, simultaneous NIR-to-NIR upconversion (UC) and down-shifting (DS) emissions are effectively achieved, due to the specific energy levels of Nd3+ dopant and the low phonon energy of the host. The luminescence mechanism related to energy transfer is discussed. The luminescence can be modulated through controlling the population of Nd3+:4F3/2 state in our experiment. Interestingly, both UC and DS emissions of the material fall within the dual biological window, suggesting that the prepared phosphors have potential applications in the bioimaging field.

  15. Off-resonance photoemission dynamics studied by recoil frame F1s and C1s photoelectron angular distributions of CH{sub 3}F

    SciTech Connect

    Stener, M. Decleva, P.; Mizuno, T.; Yagishita, A.; Yoshida, H.

    2014-01-28

    F1s and C1s photoelectron angular distributions are considered for CH{sub 3}F, a molecule which does not support any shape resonance. In spite of the absence of features in the photoionization cross section profile, the recoil frame photoelectron angular distributions (RFPADs) exhibits dramatic changes depending on both the photoelectron energy and polarization geometry. Time-dependent density functional theory calculations are also given to rationalize the photoionization dynamics. The RFPADs have been compared with the theoretical calculations, in order to assess the accuracy of the theoretical method and rationalize the experimental findings. The effect of finite acceptance angles for both ionic fragments and photoelectrons has been included in the calculations, as well as the effect of rotational averaging around the fragmentation axis. Excellent agreement between theory and experiment is obtained, confirming the good quality of the calculated dynamical quantities (dipole moments and phase shifts)

  16. Experimental investigation and theoretical analysis of pulse repetition rate adjustable deep ultraviolet picosecond radiation by second harmonic generation in KBe2BO3F2

    NASA Astrophysics Data System (ADS)

    Xu, Zhi; Zhang, Fengfeng; Zhang, Shenjin; Wang, Zhimin; Yang, Feng; Xu, Fengliang; Peng, Qinjun; Cui, Dafu; Zhang, Jingyuan; Wang, Xiaoyang; Chen, Chuangtian; Xu, Zuyan

    2014-06-01

    We reported on an experimental investigation and theoretical analysis of pulse repetition rate (PRR) adjustable deep ultraviolet (DUV) picosecond (ps) radiation by second harmonic generation (SHG) in KBe2BO3F2 (KBBF) crystal. Third harmonic radiation at 355 nm of a ps Nd:YVO4 laser output with PRR of 200 kHz-1 MHz was employed as the pump source. The dependence of the 177.3 nm output power on the 355 nm pump power was measured at different PRRs, and the maximum 177.3 nm average output power of 695 μW was obtained at the PRR of 200 kHz. The measured data agreed well with the results of the ps KBBF SHG theoretical simulations. Using simulations, the pulse width and the spectral bandwidth of the generated radiation at 177.3 nm were estimated to be 5.88 ps and 7.84 pm, respectively.

  17. Global CFC-11 (CCl3F) and CFC-12 (CCl2F2) measurements with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS): retrieval, climatologies and trends

    NASA Astrophysics Data System (ADS)

    Kellmann, Sylvia; von Clarmann, Thomas; Stiller, Gabriele P.; Eckert, Ellen; Glatthor, Norbert; Höpfner, Michael; Kiefer, Michael; Orphal, Johannes; Funke, Bernd; Grabowski, Udo; Linden, Andrea; Dutton, Geoffrey S.; Elkins, James. W.

    2013-04-01

    Vertical profiles of CFC-11 (CCl3F) and CFC-12 (CCl2F2) have been measured with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) with global coverage under daytime and nighttime conditions. Time series of altitude/latitude bins were fitted by a parametric approach including constant and linear terms, a quasi-biennial oscillation (QBO) proxy and sine and cosine terms of several periods. In the time series from 2002 to 2011, quasi-biennial and annual oscillations are clearly visible. A decrease of stratospheric CFC mixing ratios in response to the Montreal Protocol is observed for most altitudes and latitudes. However, the trends differ from the trends measured in the troposphere, even after consideration of the time lag accounting for the local age of stratospheric air. At some latitudes and altitudes, trends are even positive, and in some cases they can only be explained by decadal changes in atmospheric age of air spectra or vertical mixing patterns.

  18. Crystal structure of the binary complex of cobalt and zinc chlorides with carbamide [Co(OCN{sub 2}H{sub 4}){sub 5}(H{sub 2}O)][ZnCl{sub 4}

    SciTech Connect

    Furmanova, N. G. Chernaya, T. S.; Resnyanskii, V. F. Sulaimankulov, K. S.

    2010-03-15

    Mixed single crystals of [Co(OCN{sub 2}H{sub 4}){sub 5}(H{sub 2}O)][ZnCl{sub 4}] were grown by the isothermal evaporation of an aqueous solution. The crystal structure of this complex was established by X-ray diffraction (R = 0.052 based on 7003 reflections). The crystals consist of [Co(OCN{sub 2}H{sub 4}){sub 5}(H{sub 2}O)]{sup 2+} cations containing Co atoms in an octahedral coordination and [ZnCl{sub 4}]{sup 2-}] anions containing Zn atoms in a tetrahedral coordination. The carbamide molecules are involved in both intramolecular and interionic hydrogen bonds. The H{sub 2}O molecule forms hydrogen bonds with the anions.

  19. Phase-matching properties of yellow color HgGa2S4sub> for SHG and SFG in the 0.944-10.5910  μm range.

    PubMed

    Kato, Kiyoshi; Petrov, Valentin; Umemura, Nobuhiro

    2016-04-20

    We report new experimental results on the phase-matching properties of yellow color HgGa2S4sub> crystals for harmonic generation of an Nd:YAG laser-pumped KTiOPO4sub> (KTP) optical parametric oscillator (OPO) and CO2 lasers in the 0.944-10.5910 μm range. In addition, we present new Sellmeier equations that provide a good reproduction of the present experimental results as well as the published data points for second-harmonic generation of CO2 laser radiation at 9.2197-9.6392 μm and Nd:YAG laser-pumped OPOs at 1.205-1.725 μm and 2.77-9.10 μm that were achieved with the orange and yellow color crystals. PMID:27140080

  20. Synthesis of Ag{sub 9}(SiO{sub 4}){sub 2}NO{sub 3} through a reactive flux method and its visible-light photocatalytic performances

    SciTech Connect

    Zhu, Xianglin; Wang, Zeyan E-mail: bbhuang@sdu.edu.cn; Huang, Baibiao E-mail: bbhuang@sdu.edu.cn; Zhang, Xiaoyang; Qin, Xiaoyan; Wei, Wei; Dai, Ying

    2015-10-01

    Ag{sub 9}(SiO{sub 4}){sub 2}NO{sub 3} was prepared by a reactive flux method. The structures, morphologies, and light absorption properties were investigated. Owing to the polar crystal structure, an internal electric field can be formed inside the material, which can facilitate the photogenerated charge separation during the photocatalytic process. Based on both the wide light absorption spectra and high charge separation efficiency originated from the polarized internal electric field, Ag{sub 9}(SiO{sub 4}){sub 2}NO{sub 3} exhibit higher efficiency over Ag{sub 3}PO{sub 4} during the degradation of organic dyes under visible light irradiation, which is expected to be a potential material for solar energy harvest and conversion.

  1. Neutron-scattering evidence for a periodically modulated superconducting phase in the underdoped cuprate La1.905Ba0.095CuO4sub>

    SciTech Connect

    Xu, Zhijun; Stock, C.; Chi, Songxue; Kolesnikov, A. I.; Xu, Guangyong I.; Gu, Genda; Tranquada, J. M.

    2014-10-01

    The role of antiferromagnetic spin correlations in high-temperature superconductors remains a matter of debate. We present inelastic neutron-scattering evidence that gapless spin fluctuations coexist with superconductivity in La1.905Ba0.095CuO4sub>. Furthermore, we observe that both the low-energy magnetic spectral weight and the spin incommensurability are enhanced with the onset of superconducting correlations. We propose that the coexistence occurs through intertwining of spatial modulations of the pair wave function and the antiferromagnetic correlations. This proposal is also directly relevant to sufficiently underdoped La2-xSrxCuO4sub> and YBa2Cu3O6+x.

  2. Strain-relaxation and critical thickness of epitaxial La1.85Sr0.15CuO4sub> films

    SciTech Connect

    Meyer, Tricia L; Jiang, Lu; Park, Sungkyun; Egami, Takeshi; Lee, Ho Nyung

    2015-12-08

    We report the thickness-dependent strain-relaxation behavior and the associated impacts upon the superconductivity in epitaxial La1.85Sr0.15CuO4sub> films grown on different substrates, which provide a range of strain. We have found that the critical thickness for the onset of superconductivity in La1.85Sr0.15CuO4sub> films is associated with the finite thickness effect and epitaxial strain. In particular, thin films with tensile strain greater than ~0.25% revealed no superconductivity. We attribute this phenomenon to the inherent formation of oxygen vacancies that can be minimized via strain relaxation.

  3. Growth of the (In{sub 2}S{sub 3}){sub x}(FeIn{sub 2}S{sub 4}){sub 1-x} single crystals and properties of photoelectric structures on their basis

    SciTech Connect

    Bodnar, I. V.; Rud, V. Yu.; Rud, Yu. V.; Terukov, E. I.

    2010-01-15

    Complete mutual solubility in the (In{sub 2}S{sub 3}){sub x}(FeIn{sub 2}S{sub 4}){sub 1-x} system is established. The technology is developed, and single crystals of the continuous series of the (In{sub 2}S{sub 3}){sub x}(FeIn{sub 2}S{sub 4}){sub 1-x} solid solutions are grown for the first time. The linear dependence of the unit cell parameter of single crystals with a cubic spinel lattice on the solid solution composition is found. First, photosensitive Schottky barriers are fabricated, and then, based on studies of their photosensitivity, the character of band-to-band transition is discussed and the values of the band gap depending on the atomic composition are estimated. The possibility of using the obtained solid solutions as broadband photoconverters of optical radiation is revealed.

  4. Eye-safe 1.55  μm passively Q-switched Er,Yb:GdAl3(BO3)4sub> diode-pumped laser.

    PubMed

    Gorbachenya, K N; Kisel, V E; Yasukevich, A S; Maltsev, V V; Leonyuk, N I; Kuleshov, N V

    2016-03-01

    We report for the first time, to the best of our knowledge, on a diode-pumped passively Q-switched Er,Yb:GdAl3(BO3)4sub> laser. By using a Co2+:MgAl2O4sub> crystal as a saturable absorber, Q-switched laser pulses with a duration of 12 ns and a maximum energy of 18.7 μJ at a repetition rate of 32 kHz corresponding to an average output power of 0.6 W were obtained at 1550 nm under continuous-wave pumping. In the burst mode of operation, Q-switched laser pulses with the highest energy up to 44 μJ were realized with a pulse repetition rate of 6.5 kHz. PMID:26974080

  5. Alteration of Electrostatic Surface Potential Enhances Affinity and Tumor Killing Properties of Anti-ganglioside GD2 Monoclonal Antibody hu3F8*

    PubMed Central

    Zhao, Qi; Ahmed, Mahiuddin; Guo, Hong-fen; Cheung, Irene Y.; Cheung, Nai-Kong V.

    2015-01-01

    Ganglioside GD2 is highly expressed on neuroectodermal tumors and an attractive therapeutic target for antibodies that have already shown some clinical efficacy. To further improve the current antibodies, which have modest affinity, we sought to improve affinity by using a combined method of random mutagenesis and in silico assisted design to affinity-mature the anti-GD2 monoclonal antibody hu3F8. Using yeast display, mutants in the Fv with enhanced binding over the parental clone were FACS-sorted and cloned. In silico modeling identified the minimal key interacting residues involved in the important charged interactions with the sialic acid groups of GD2. Two mutations, D32H (L-CDR1) and E1K (L-FR1) altered the electrostatic surface potential of the antigen binding site, allowing for an increase in positive charge to enhance the interaction with the negatively charged GD2-pentasaccharide headgroup. Purified scFv and IgG mutant forms were then tested for antigen specificity by ELISA, for tissue specificity by immunohistochemistry, for affinity by BIACORE, for antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-mediated cytotoxicity in vitro, and for anti-tumor efficacy in xenografted humanized mice. The nearly 7-fold improvement in affinity of hu3F8 with a single D32H (L-CDR1) mutation translated into a ∼12-fold improvement in NK92MI-transfected CD16-mediated ADCC, a 6-fold improvement in CD32-mediated ADCC, and a 2.5-fold improvement in complement-mediated cytotoxicity while maintaining restricted normal tissue cross-reactivity and achieving substantial improvement in tumor ablation in vivo. Despite increasing GD2 affinity, the double mutation D32H (L-CDR1) and E1K (L-FR1) did not further improve anti-tumor efficacy. PMID:25851904

  6. Serological and virological survey of hepatitis E virus in wild boar populations in northwestern Italy: detection of HEV subtypes 3e and 3f.

    PubMed

    Caruso, Claudio; Modesto, P; Bertolini, S; Peletto, S; Acutis, P L; Dondo, A; Robetto, S; Mignone, W; Orusa, R; Ru, G; Masoero, L

    2015-01-01

    Although rare in developed countries, most acquired human cases of hepatitis E virus (HEV) infection are associated with travel to developing countries where HEV is endemic. Increasingly, however, sporadic, non-travel-related HEV cases have been reported in developed countries. In Italy, only two studies to date have investigated the presence of HEV in wild boars. Here, we report a serological and virological survey of HEV in wild boar populations in northwestern Italy. During the hunting season, 594 serum and 320 liver samples were collected and screened for antibodies to HEV and HEV RNA. Overall, the seroprevalence was 4.9 %, and HEV RNA was detected in 12 liver samples (p = 3.7 %). No serum samples tested positive for HEV RNA. Phylogenetic analysis of the ORF2 region revealed that the isolates clustered within genotype 3, subtypes 3e and 3f, and were closely related to HEV strains previously detected in domestic pigs farmed in the same geographic area. Although the routes of viral transmission are still poorly understood, our data show that HEV genotypes 3e and 3f circulate in wild boars in northwestern Italy. Also, they provide evidence that autochthonous HEV infections in Italy could also be linked to wild boar populations, suggesting an increased risk for domestically acquired HEV infection in humans through wild animals. The HEV sequences determined in this study may be useful for comparing present and future human isolates to identify transmission events between wild boar, humans, and farmed pigs. Similarly to other more commonly known zoonotic agents, HEV should be included in national or regional disease surveillance programs for wild animals. PMID:25283611

  7. Global Gene Profiling of Spontaneous Hepatocellular Carcinoma in B6C3F1 Mice: Similarities in the Molecular Landscape with Human Liver Cancer

    PubMed Central

    Hoenerhoff, Mark J.; Pandiri, Arun R.; Lahousse, Stephanie A.; Hong, Hu-Hua; Ton, Tai-Vu; Masinde, Tiwanda; Auerbach, Scott S.; Gerrish, Kevin; Bushel, Pierre R.; Shockley, Keith R.; Peddada, Shyamal D.; Sills, Robert C.

    2016-01-01

    Hepatocellular carcinoma (HCC) is an important cause of morbidity and mortality worldwide. Although the risk factors of human HCC are well known, the molecular pathogenesis of this disease is complex, and in general, treatment options remain poor. The use of rodent models to study human cancer has been extensively pursued, both through genetically engineered rodents and rodent models used in carcinogenicity and toxicology studies. In particular, the B6C3F1 mouse used in the National Toxicology Program (NTP) two-year bioassay has been used to evaluate the carcinogenic effects of environmental and occupational chemicals, and other compounds. The high incidence of spontaneous HCC in the B6C3F1 mouse has challenged its use as a model for chemically induced HCC in terms of relevance to the human disease. Using global gene expression profiling, we identify the dysregulation of several mediators similarly altered in human HCC, including re-expression of fetal oncogenes, upregulation of protooncogenes, downregulation of tumor suppressor genes, and abnormal expression of cell cycle mediators, growth factors, apoptosis regulators, and angiogenesis and extracellular matrix remodeling factors. Although major differences in etiology and pathogenesis remain between human and mouse HCC, there are important similarities in global gene expression and molecular pathways dysregulated in mouse and human HCC. These data provide further support for the use of this model in hazard identification of compounds with potential human carcinogenicity risk, and may help in better understanding the mechanisms of tumorigenesis resulting from chemical exposure in the NTP two-year carcinogenicity bioassay. PMID:21571946

  8. Fumonisin b1 carcinogenicity in a two-year feeding study using F344 rats and B6C3F1 mice.

    PubMed Central

    Howard, P C; Eppley, R M; Stack, M E; Warbritton, A; Voss, K A; Lorentzen, R J; Kovach, R M; Bucci, T J

    2001-01-01

    Fumonisin B1 (FB1) is a mycotoxin isolated from Fusarium fungi that contaminate crops worldwide. A previous study demonstrated that FB1 promoted preneoplastic foci in initiated rats and induced hepatocellular carcinomas in BD IX rats at 50 parts per million (ppm), but fundamental dose-response data were not available to assist in setting regulatory guidelines for this mycotoxin. To provide this information, female and male F344/N/Nctr BR rats and B6C3F1 Nctr BR mice were fed for two years a powdered NIH-31 diet containing the following concentrations of FB1: female rats, 0, 5, 15, 50, and 100 ppm; male rats, 0, 5, 15, 50, and 150 ppm; female mice, 0, 5, 15, 50, and 80 ppm; male mice, 0, 5, 15, 80, and 150 ppm. FB1 was not tumorigenic in female F344 rats with doses as high as 100 ppm. Including FB1 in the diets of male rats induced renal tubule adenomas and carcinomas in 0/48, 0/40, 9/48, and 15/48 rats at 0, 5, 15, 50, and 150 ppm, respectively. Including up to 150 ppm FB1 in the diet of male mice did not affect tumor incidence. Hepatocellular adenomas and carcinomas were induced by FB1 in the female mice, occurring in 5/47, 3/48, 1/48, 19/47, and 39/45 female mice that consumed diets containing 0, 5, 15, 50, and 80 ppm FB1, respectively. This study demonstrates that FB1 is a rodent carcinogen that induces renal tubule tumors in male F344 rats and hepatic tumors in female B6C3F1 mice. PMID:11359696

  9. Alteration of Electrostatic Surface Potential Enhances Affinity and Tumor Killing Properties of Anti-ganglioside GD2 Monoclonal Antibody hu3F8.

    PubMed

    Zhao, Qi; Ahmed, Mahiuddin; Guo, Hong-fen; Cheung, Irene Y; Cheung, Nai-Kong V

    2015-05-22

    Ganglioside GD2 is highly expressed on neuroectodermal tumors and an attractive therapeutic target for antibodies that have already shown some clinical efficacy. To further improve the current antibodies, which have modest affinity, we sought to improve affinity by using a combined method of random mutagenesis and in silico assisted design to affinity-mature the anti-GD2 monoclonal antibody hu3F8. Using yeast display, mutants in the Fv with enhanced binding over the parental clone were FACS-sorted and cloned. In silico modeling identified the minimal key interacting residues involved in the important charged interactions with the sialic acid groups of GD2. Two mutations, D32H (L-CDR1) and E1K (L-FR1) altered the electrostatic surface potential of the antigen binding site, allowing for an increase in positive charge to enhance the interaction with the negatively charged GD2-pentasaccharide headgroup. Purified scFv and IgG mutant forms were then tested for antigen specificity by ELISA, for tissue specificity by immunohistochemistry, for affinity by BIACORE, for antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-mediated cytotoxicity in vitro, and for anti-tumor efficacy in xenografted humanized mice. The nearly 7-fold improvement in affinity of hu3F8 with a single D32H (L-CDR1) mutation translated into a ∼12-fold improvement in NK92MI-transfected CD16-mediated ADCC, a 6-fold improvement in CD32-mediated ADCC, and a 2.5-fold improvement in complement-mediated cytotoxicity while maintaining restricted normal tissue cross-reactivity and achieving substantial improvement in tumor ablation in vivo. Despite increasing GD2 affinity, the double mutation D32H (L-CDR1) and E1K (L-FR1) did not further improve anti-tumor efficacy. PMID:25851904

  10. Structure electronic and ionic conductivity study versus Ca content in Ca{sub 10-x}Sr{sub x}(PO{sub 4}){sub 6}F{sub 2} apatites

    SciTech Connect

    Sghir, B.; Hlil, E.K.; Laghzizil, A.; Boujrhal, F.Z.; Cherkaoui El Moursli, R.; Fruchart, D.

    2009-07-01

    Substitution effect on the crystallographic structure in Ca{sub 10-x}Sr{sub x}(PO{sub 4}){sub 6}F{sub 2} solid solution are studied by X-ray diffraction patterns and Rietveld refinements. Full potential electronic structure calculations based on LCAO (linear combination atomic orbital) are also performed using the obtained crystallographic parameters. DOS modification and the charge transfer are estimated versus the calcium content. According to the complex impedance method, ionic conductivity changes are explained.

  11. Single-Step Synthesis of FeSO4sub>F1-yOHy (0 ≤ y ≤ 1) Positive Electrodes for Li-Based Batteries

    SciTech Connect

    Ati, M; Sougrati, M-T; Rousse, G; Recham, N; Doublet, M-L; Jumas, J-C; Tarascon, J-M

    2012-05-29

    The recent discovery of electrochemical activity at 3.6 V vs Li+/Li0 in LiFeSO4sub>F has generated widespread research activity in this new family of fluorosulfate electrode materials aiming at either increasing the Fe3+/Fe2+ redox potential, searching for new active members, or extending this family to hydroxyl-fluorosulfates. Here we present a new low temperature single step synthesis of FeSO4sub>F1-yOHy phases using FeF3 and Fe2(SO4sub>)3 ∙ nH2O as precursors. Using thorough chemical analytical techniques to test for F- content in conjunction with Moessbauer measurements, we demonstrate the existence of a limited solid solution (0.35 < y < 1) within this system. Members pertaining to this solid solution have a redox activity ranging from 3.2 to 3.6 V vs Li+/Li0 and show sustained reversible capacity retention of 130 mAh/g which makes them potentially interesting for Li-based polymer batteries. We demonstrate that the Li-insertion-deinsertion mechanism depends markedly on the sample F- content by using joint in situ XRD and Moessbauer spectroscopy. Moreover, we show the versatility of our synthetic approach by extending it to the elaboration of Fe1-zMzSO4sub>F1-yOHy phases with M = Ti and V.

  12. Synthetic and spectroscopic studies of vanadate glaserites II: Photoluminescence studies of Ln:K{sub 3}Y(VO{sub 4}){sub 2} (Ln=Eu, Er, Sm, Ho, or Tm)

    SciTech Connect

    Kimani, Martin M. McMillen, Colin D. Kolis, Joseph W.

    2015-03-15

    Glaserite-type potassium yttrium double vanadates (K{sub 3}Y(VO{sub 4}){sub 2}) doped with Eu{sup 3+}, Er{sup 3+}, Sm{sup 3+}, Ho{sup 3+}, or Tm{sup 3+} have been synthesized by solid state reactions at 1000 °C for 48 h and their photoluminescence properties investigated. Efficient energy transfer from the vanadate group to the rare earth ion has been established by photoluminescence investigation. Ultraviolet excitation into the metal to ligand charge transfer band of the vanadate groups results in orange-red, blue and green emissions from Eu{sup 3+} (592 nm), Sm{sup 3+} (602 nm), Tm{sup 3+} (475 nm), Er{sup 3+} (553 nm), and Ho{sup 3+} (541–551 nm) dopant ions. The emission intensities of the lanthanide-doped K{sub 3}Y(VO{sub 4}){sub 2} powders were studied as a function of dopant ion concentrations. Over the concentration ranges studied, no emission quenching was observed for Eu{sup 3+} or Ho{sup 3+} dopants, while Er{sup 3+}, Sm{sup 3+} and Tm{sup 3+} dopants did exhibit such effects for dopant ion concentrations greater than 5%, probably due to cross relaxation processes. - Graphical abstract: Synthesis and photoluminescence in vanadate glaserites. - Highlights: • K{sub 3}Y(VO{sub 4}){sub 2} doped with Eu, Er, Tm, Sm, or Ho were synthesized via solid-state reactions. • Photoluminescence properties are investigated. • The lanthanide doped K{sub 3}Y(VO{sub 4}){sub 2} compounds revealed efficient energy transfer from the vanadate group to the rare earth ions. • The presented compounds are promising materials for light display systems, lasers, and optoelectronic devices.

  13. A limited role for carbonic anhydrase in C4sub> photosynthesis as revealed by a ca1ca2 double mutant in maize.

    SciTech Connect

    Studer, Anthony J.; Gandin, Anthony; Kolbe, Allison R.; Wang, Lin; Cousins, Asaph B.; Brutnell, Thomas P.

    2014-04-04

    Carbonic anhydrase (CA) catalyzes the first biochemical step of the carbon concentrating mechanism of C4sub> plants, and in C4sub> monocots, it has been suggested that CA activity is near limiting for photosynthesis. Here, we test this hypothesis through the characterization of transposon induced mutant alleles of Ca1 and Ca2 in Zea mays. In addition, these two isoforms account for more than 85% of the CA transcript pool. A significant change in isotopic discrimination is observed in mutant plants, which have as little as 3% of wild-type CA activity, but surprisingly, photosynthesis is not reduced under current or elevated pCO2. However, growth and rates of photosynthesis under sub-ambient pCO2 are significantly impaired in the mutants. These findings suggest, that while CA is not limiting for C4sub> photosynthesis in Z. mays at current pCO2, it likely maintains high rates of photosynthesis when CO2 availability is reduced. Current atmospheric CO2 levels now exceed 400 ppm (~40.53 Pa) and contrast the low CO2 partial pressure (pCO2) conditions under which C4sub> plants expanded their range ~10 million years ago when the global atmospheric CO2 was below 300 ppm (~30.40 Pa). Thus, as CO2 levels continue to rise, selective pressures for high levels of CA may be limited to arid climates where stomatal closure reduces CO2 availability to the leaf.

  14. Temperature dependence of the luminescence of calcium-magnesium phosphate Ca{sub 3}Mg{sub 3}(PO{sub 4}){sub 4}:Eu{sup 2+}, a blue-emitting material for white light-emitting diodes

    SciTech Connect

    Zhang, Xinmin; Pan, Qi; Kim, Sun Il; Yu, Young Moon; Seo, Hyo Jin

    2014-03-01

    Graphical abstract: - Highlights: • Emission spectrum at 20 K confirms that Eu{sup 2+} ions occupy three sites. • Decay curves of three types of Eu{sup 2+} reflect the characteristics of energy transfer. • The Eu(I) emission is thermally quenched at 323 K. • Ca{sub 3}Mg{sub 3}(PO{sub 4}){sub 4}:Eu{sup 2+} has good thermal stability. • Ca{sub 3}Mg{sub 3}(PO{sub 4}){sub 4}:Eu{sup 2+} is a promising phosphor for near UV excited white LEDs. - Abstract: A blue-emitting phosphor Ca{sub 3}Mg{sub 3}(PO{sub 4}){sub 4}:Eu{sup 2+} peaking at 450 nm was synthesized by a solid state reaction. The XRD patterns, luminescence properties, decay curves of samples as well as their thermal quenching and comparing the luminescence properties with that of commercial material were investigated. At 20 K, the emission spectrum exhibiting two distinct bands peaking at 437 and 473 nm with a shoulder peak at 510 nm can be attributed to the overlap of Eu(I), Eu(II) and Eu(III) emission bands. At 423 K the PL intensity decreases to 80% of the value at room temperature, and the emission wavelength shifts toward high energy. The derived activation energy indicates that the lowest energy level of the Eu{sup 2+} 4f{sup 6}5d{sup 1} state is well isolated from the host lattice conduction band. The PL spectra and chromaticity coordinates are close to those of BAM. Ca{sub 3}Mg{sub 3}(PO{sub 4}){sub 4}:Eu{sup 2+} could be a potential candidate for near-UV excited white LEDs.

  15. Electrical and physical characterization of the Al{sub 2}O{sub 3}/p-GaSb interface for 1%, 5%, 10%, and 22% (NH{sub 4}){sub 2}S surface treatments

    SciTech Connect

    Peralagu, Uthayasankaran Thayne, Iain G.; Povey, Ian M.; Carolan, Patrick; Lin, Jun; Hurley, Paul K.; Contreras-Guerrero, Rocio; Droopad, Ravi

    2014-10-20

    In this work, the impact of ammonium sulfide ((NH{sub 4}){sub 2}S) surface treatment on the electrical passivation of the Al{sub 2}O{sub 3}/p-GaSb interface is studied for varying sulfide concentrations. Prior to atomic layer deposition of Al{sub 2}O{sub 3}, GaSb surfaces were treated in 1%, 5%, 10%, and 22% (NH{sub 4}){sub 2}S solutions for 10 min at 295 K. The smallest stretch-out and flatband voltage shifts coupled with the largest capacitance swing, as indicated by capacitance-voltage (CV) measurements, were obtained for the 1% treatment. The resulting interface defect trap density (D{sub it}) distribution showed a minimum value of 4 × 10{sup 12 }cm{sup −2}eV{sup −1} at E{sub v} + 0.27 eV. Transmission electron microscopy and atomic force microscopy examination revealed the formation of interfacial layers and increased roughness at the Al{sub 2}O{sub 3}/p-GaSb interface of samples treated with 10% and 22% (NH{sub 4}){sub 2}S. In combination, these effects degrade the interface quality as reflected in the CV characteristics.

  16. Luminescence properties of Ca{sub 14}Mg{sub 2}(SiO{sub 4}){sub 8}:Eu{sup 2+} from various Eu{sup 2+} sites for white-light-emitting diodes

    SciTech Connect

    Zhang, Jia Jiang, Cheng

    2014-12-15

    Ca{sub 14}Mg{sub 2}(SiO{sub 4}){sub 8}:Eu{sup 2+} phosphors were synthesized by solid-state reaction method, and their luminescence properties were investigated. In the emission spectra, several overlapping emission bands originating from various Eu{sup 2+} sites were found. Eu{sup 2+} in Ca{sub 14}Mg{sub 2}(SiO{sub 4}){sub 8} exhibits green emission around 506 nm, and the sample doped with 0.1 mol% Eu{sup 2+} shows the strongest brightness under 365 nm excitation with the quantum efficiency of 63.6%. In the excitation spectra, strong and broad excitation bands from 250 to 450 nm were observed, which could well match with the emission wavelength of the light-emitting diode chip. The fabrication test on the InGaN chip indicates the Ca{sub 14}Mg{sub 2}(SiO{sub 4}){sub 8}:Eu{sup 2+} phosphor could be promising candidate for white light-emitting diodes.

  17. Temperature-induced changes in the single-crystal structure of K{sub 9}H{sub 7}(SO{sub 4}){sub 8} {center_dot} H{sub 2}O

    SciTech Connect

    Makarova, I. P. Grebenev, V. V.; Chernaya, T. S.; Verin, I. A.; Dolbinina, V. V.; Chernyshov, D. Yu.; Koval'chuk, M. V.

    2013-05-15

    Interest in superprotonic crystals of M{sub m}H{sub n}(XO{sub 4}){sub (m+n)/2} is associated with the solution to the fundamental problem of modern condensed matter physics: investigations of structural phase transitions and the stabilization of phases with high proton conductivity with the aim of designing new functional materials. The available data suggest that changes in the physical properties in these crystals can occur through different structural mechanisms. To reveal the structural conditionality for anomalies in the physical properties, the crystals of K{sub 9}H{sub 7}(SO{sub 4}){sub 8} {center_dot} H{sub 2}O were studied by X-ray diffraction in the temperature range of 25-463 K, and the crystal structure of the high-temperature phase was determined at 418 K (sp. gr. Pcan). The results of the study indicate that the occurrence of high conductivity in K{sub 9}H{sub 7}(SO{sub 4}){sub 8} {center_dot} H{sub 2}O crystals at high temperatures is associated with the diffusion of water of crystallization, the hydrogen-bond network rearrangement, and the motion of K ions. The hydrogen-bond rearrangement and the hindered back diffusion of water to the crystal stabilize the high-temperature phase and ensure its supercooling to low temperatures.

  18. Consequences of Optimal Bond Valence on Structural Rigidity and Improved Luminescence Properties in SrxBa2-xSiO4sub>:Eu2+ Orthosilicate Phosphors

    SciTech Connect

    Denault, Kristin A.; Brgoch, Jakoah; Gaultois, Michael W.; Mikhailovsky, Alexander; Petry, Ralf; Winkler, Holger; DenBaars, Steven P.; Seshadri, Ram

    2014-08-19

    The orthosilicate phosphors SrxBa2–xSiO4sub>:Eu2+ have now been known for over four decades and have found extensive recent use in solid-state white lighting. It is well-recognized in the literature and in practice that intermediate compositions in the solid-solutions between the orthosilicates Sr2SiO4sub> and Ba2SiO4sub> yield the best phosphor hosts when the thermal stability of luminescence is considered. We employ a combination of synchrotron X-ray diffraction, total scattering measurements, density functional theory calculations, and low-temperature heat capacity measurements, in conjunction with detailed temperature- and time-resolved studies of luminescence properties to understand the origins of the improved luminescence properties. We observe that in the intermediate compositions, the two cation sites in the crystal structure are optimally bonded as determined from bond valence sum calculations. Optimal bonding results in a more rigid lattice, as established by the intermediate compositions possessing the highest Debye temperature, which are determined experimentally from low-temperature heat capacity measurements. Greater rigidity in turn results in the highest luminescence efficiency for intermediate compositions at elevated temperatures.

  19. Influence of Ga-concentration on the electrical and magnetic properties of magnetoelectric CoGaxFe2–xO4sub>/BaTiO3 composite

    SciTech Connect

    Ni, Yan; Zhang, Zhen; Nlebedim, Cajetan I.; Jiles, David C.

    2015-03-20

    Multiferroic materials exhibit magnetoelectric (ME) coupling and promise new device applications including magnetic sensors, generators, and filters. An effective method for developing ME materials with enhanced ME effect is achieved by the coupling through the interfacial strain between piezoelectric and magnetostrictive materials. In this study, the electrical and magnetic properties of Ga doped magnetoelectric CoGaxFe2–xO4sub>/BaTiO3 composite are studied systematically. It is found that Ga doping improves the sensitivity of magnetoelastic response and stabilizes the magnetic phase of the composites. More importantly, Ga doping reduces the electrical conductivity of composite, as well as the dielectric loss. An enhancement of the electrostrain with doping Ga is also observed. Quantitative estimation indicates that magnetoelectric coupling is enhanced for Ga-doped CoGaxFe2–xO4sub>/BaTiO3 composites. As a result, the present work is beneficial to the practical application of composite CoFe2O4sub>/BaTiO3-based multiferroic materials.

  20. Thermodynamic Model for the Solubility of NdF3(cr) in the Na+-NH4sub>+ – Nd3+–F-–H2O System at 25 °C

    SciTech Connect

    Rai, Dhanpat; Yui, Mikazu; Kitamura, Akira; Yoshikawa, Hideki; Felmy, A. R.

    2013-08-02

    The objectives of this study were to develop a reliable thermodynamic model for the Nd-F system based on critical review and experimental studies. The SIT model was used to convert concentration constants reported in the literature to constants at zero ionic strengths for cross comparison and selection of reliable values. The critically evaluated thermodynamic constants for the formation of NdF2+ and NdF2+ were then used to interpret the extensive NdF3(cr) solubility data in NaF and NH4sub>F solutions, ranging in concentrations from extremely low values to as high as 1.0 mol.kg-1, equilibrated for different periods ranging up to as long as 72 days. These efforts have resulted in log βn0 for the reaction [Nd3+ + nF- = NdFn3-n] of (3.81 ± 0.10), (5.89 ± 0.77), and <12.48 for n of 1 through 3, respectively. The log10 Ksp0 for the solubility of NdF3(cr) (NdF3(cr) = Nd3+ + 3F-) was determined to be -(20.49 ± 0.37). Because 1) Nd is an excellent analog for trivalent actinides -- An(III) (e.i., Pu(III), Am(III), and Cm(III)) -- and 2) the available data for the An(III)-F system, especially the solubility products of AnF3(cr), are of extremely poor quality, the critical literature review in combination with the experimental Nd-F system data have been used to assign thermodynamic constants for the An(III)-F reactions until good quality specific data for them becomes available.

  1. Site and local structure of activator Eu{sup 2+} in phosphor Ca{sub 10−x}(PO{sub 4}){sub 6}Cl{sub 2}:xEu{sup 2+}

    SciTech Connect

    Wang, Chun-Hai; Gui, Dong-Yun; Qin, Rui; Yang, Feng-Li; Jing, Xi-Ping; Tian, Guang-Shan; Zhu, Wenjun

    2013-10-15

    The site and local structure of activator Eu{sup 2+} in phosphor Ca{sub 10−x}(PO{sub 4}){sub 6}Cl{sub 2}:xEu{sup 2+} is investigated by experiment measurements, first-principle calculations and XAFS simulations. From first-principle calculations, the “local” structure [bond length L(M–O)≤R(M{sup 2+})+R(O{sup 2−})] of host shows a significant deformation (expansion) when Ca{sup 2+} is substituted by Eu{sup 2+}, and Eu{sup 2+} should prefer 6h site to 4f site in the host. The d→f emission of Eu{sup 2+} at 4f site should show a longer wavelength than that of Eu{sup 2+} at 6h site. The XAFS measurement and simulations suggest that the Eu{sup 2+} in our Ca{sub 9.9}(PO{sub 4}){sub 6}Cl{sub 2}:0.1Eu{sup 2+} sample mainly locates at 6h site. In the emission spectrum, two emission profiles of Ca{sub 9.9}(PO{sub 4}){sub 6}Cl{sub 2}:0.1Eu{sup 2+} sample are obtained and assigned. The major one (2.71 eV≈456 nm) should be the emission of Eu{sup 2+} at 6h site. The minor one (2.61 eV≈465 nm) should be that of Eu{sup 2+} at 4f site. - Graphical abstract: The d→f emission of Eu{sup 2+} in Ca{sub 9.9}(PO{sub 4}){sub 6}Cl{sub 2}:0.1Eu{sup 2+} can be assigned as: emission profile at 2.71 eV and 2.61 eV are Eu{sup 2+} at 6h and 4f site, respectively. Display Omitted - Highlights: • Eu{sup 2+} in Ca{sub 10−x}(PO{sub 4}){sub 6}Cl{sub 2}:xEu{sup 2+} causes deformation to “local” structure. • Eu{sup 2+} should prefer 6h site to 4f site in the host from energy aspect. • Emission at 2.71 eV and 2.61 eV should be Eu{sup 2+} at 6h and 4f site.

  2. Ground-based, integrated path differential absorption LIDAR measurement of CO2, CH4sub>, and H2O near 1.6  μm.

    PubMed

    Wagner, Gerd A; Plusquellic, David F

    2016-08-10

    A ground-based, integrated path, differential absorption light detection and ranging (IPDA LIDAR) system is described and characterized for a series of nighttime studies of CO2, CH4sub>, and H2O. The transmitter is based on an actively stabilized, continuous-wave, single-frequency external-cavity diode laser (ECDL) operating from 1.60 to 1.65 μm. The fixed frequency output of the ECDL is microwave sideband tuned using an electro-optical phase modulator driven by an arbitrary waveform generator and filtered using a confocal cavity to generate a sequence of 123 frequencies separated by 300 MHz. The scan sequence of single sideband frequencies of 600 ns duration covers a 37 GHz region at a spectral scan rate of 10 kHz (100 μs per scan). Simultaneously, an eye-safe backscatter LIDAR system at 1.064 μm is used to monitor the atmospheric boundary layer. IPDA LIDAR measurements of the CO2 and CH4sub> dry air mixing ratios are presented in comparison with those from a commercial cavity ring-down (CRD) instrument. Differences between the IPDA LIDAR and CRD concentrations in several cases appear to be well correlated with the atmospheric aerosol structure from the backscatter LIDAR measurements. IPDA LIDAR dry air mixing ratios of CO2 and CH4sub> are determined with fit uncertainties of 2.8 μmol/mol (ppm) for CO2 and 22 nmol/mol (ppb) for CH4sub> over 30 s measurement periods. For longer averaging times (up to 1200 s), improvements in these detection limits by up to 3-fold are estimated from Allan variance analyses. Two sources of systematic error are identified and methods to remove them are discussed, including speckle interference from wavelength decorrelation and the seed power dependence of amplified spontaneous emission. Accuracies in the dry air retrievals of CO2 and CH4sub> in a 30 s measurement period are estimated at 4 μmol/mol (1% of ambient levels) and 50

  3. Synthesis, crystal structure and properties of alluaudite-like triple molybdate Na{sub 25}Cs{sub 8}Fe{sub 5}(MoO{sub 4}){sub 24}

    SciTech Connect

    Savina, Aleksandra A.; Solodovnikov, Sergey F.; Belov, Dmitry A.; Basovich, Olga M.; Solodovnikova, Zoya A.; Pokholok, Konstantin V.; Stefanovich, Sergey Yu.; Lazoryak, Bogdan I.; Khaikina, Elena G.

    2014-12-15

    A new triple molybdate Na{sub 25}Cs{sub 8}Fe{sub 5}(MoO{sub 4}){sub 24} was synthesized using solid state reactions and studied with X-ray powder diffraction, second harmonic generation (SHG) technique, differential scanning calorimetry, Mössbauer and dielectric impedance spectroscopy. Single crystals of Na{sub 25}Cs{sub 8}Fe{sub 5}(MoO{sub 4}){sub 24} were obtained and its structure was solved (the space group P1{sup ¯}, a=12.5814(5), b=13.8989(5), c=28.4386(9) Å, α=90.108(2), β=90.064(2), γ=90.020(2)°, V=4973.0(3) Å{sup 3}, Z=2, R=0.0440). Characteristic features of the structure are polyhedral layers composed of pairs of edge-shared FeO{sub 6} and (Fe, Na)O{sub 6} octahedra, which are connected by bridging MoO{sub 4} tetrahedra. The layers share common vertices with bridging MoO{sub 4} tetrahedra to form an open 3D framework with the cavities occupied by the Cs{sup +} and Na{sup +} cations. The compound undergoes first-order phase transformation at 642 K and above this phase transition, electrical conductivity reaches 10{sup −3}–10{sup −2} S cm{sup −1}. Thus, Na{sub 25}Cs{sub 8}Fe{sub 5}(MoO{sub 4}){sub 24} may be considered as a promising compound for developing new materials with high ionic conductivity. - Graphical abstract: A new triple molybdate Na{sub 25}Cs{sub 8}Fe{sub 5}(MoO{sub 4}){sub 24} was synthesized and structurally characterized, its physicochemical properties were studied. - Highlights: • New compound Na{sub 25}Cs{sub 8}Fe{sub 5}(MoO{sub 4}){sub 24} was synthesized. • Physicochemical properties of the compound were studied. • The first-order phase transformation is observed. • Electrical conductivity above 642 K is (10{sup −2}–10{sup −3}) S cm{sup −1}. • New compound may be considered as promising object with high ionic conductivity.

  4. Microwave sol–gel synthesis and upconversion photoluminescence properties of CaGd{sub 2}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb{sup 3+} phosphors with incommensurately modulated structure

    SciTech Connect

    Lim, Chang Sung; Aleksandrovsky, Aleksandr; Molokeev, Maxim; Oreshonkov, Aleksandr; Atuchin, Victor

    2015-08-15

    CaGd{sub 2−x}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb{sup 3+} phosphors with the doping concentrations of Er{sup 3+} and Yb{sup 3+} (x=Er{sup 3+}+Yb{sup 3+}, Er{sup 3+}=0.05, 0.1, 0.2 and Yb{sup 3+}=0.2, 0.45) have been successfully synthesized by the microwave sol–gel method. The crystal structure of CaGd{sub 2−x}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb{sup 3+} tungstates have been refined, and upconversion photoluminescence properties have been investigated. The synthesized particles, being formed after the heat-treatment at 900 °C for 16 h, showed a well crystallized morphology. Under the excitation at 980 nm, CaGd{sub 2}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb{sup 3+} particles exhibited a strong 525-nm and a weak 550-nm emission bands in the green region and a very weak 655-nm emission band in the red region. The Raman spectrum of undoped CaGd{sub 2}(WO{sub 4}){sub 4} revealed about 12 narrow lines. The strongest band observed at 903 cm{sup −1} was assigned to the ν{sub 1} symmetric stretching vibration of WO{sub 4} tetrahedrons. The spectra of the samples doped with Er and Yb obtained under the 514.5 nm excitation were dominated by Er{sup 3+} luminescence preventing the recording of these samples Raman spectra. Concentration quenching of the erbium luminescence at {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2} transition is weak in the range of erbium doping level x{sub Er}=0.05–0.2, while, for transition {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2}, the signs of concentration quenching become pronounced at x{sub Er}=0.2. - Graphical abstract: CaGd{sub 2−x}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb{sup 3+} phosphors with the doping concentrations of Er{sup 3+} and Yb{sup 3+} (x=Er{sup 3+}+Yb{sup 3+}, Er{sup 3+}=0.05, 0.1, 0.2 and Yb{sup 3+}=0.2, 0.45) have been successfully synthesized by the microwave sol–gel method and the crystal structure refinement, and upconversion photoluminescence properties have been investigated. - Highlights: • CaGd{sub 2−x}(WO{sub 4}){sub 4}:Er{sup 3+}/Yb

  5. Inhalation toxicology and carcinogenicity of 1,3-butadiene in B6C3F1 mice following 65 weeks of exposure.

    PubMed Central

    Melnick, R L; Huff, J E; Roycroft, J H; Chou, B J; Miller, R A

    1990-01-01

    1,3-Butadiene, a large-production volume chemical used mainly in the manufacture of synthetic rubber, was found to induce multiple-organ carcinogenicity in male and female B6C3F1 mice at exposure concentrations (625 and 1250 ppm) equivalent to and below the OSHA standard of 1000 ppm. Since this study was terminated after 60 weeks of exposure because of reduced survival due to fatal tumors, and because dose-response relationships for 1,3-butadiene-induced neoplastic and nonneoplastic lesions were not clearly established, a second long-term inhalation study of 1,3-butadiene in B6C3F1 mice was conducted at lower exposure concentrations, ranging from 6.25 to 625 ppm. Both the histopathological findings from animals dying through week 65 and the results of evaluations of animals exposed for 40 and 65 weeks are presented in this report. Exposure to 1,3-butadiene caused a regenerative anemia at concentrations of 62.5 ppm and higher. Testicular atrophy was induced at 625 ppm, and ovarian atrophy was observed at 20 ppm and higher. During the first 50 weeks of the study, lymphocytic lymphoma was the major cause of death of mice exposed to 625 ppm 1,3-butadiene. Neoplasms of the heart, forestomach, lung, Harderian gland, mammary gland, ovary, and liver were frequently observed in 1,3-butadiene-exposed mice that died between week 40 and week 65 of the study. Studies in which exposure to 1,3-butadiene was stopped after limited periods were also included to assess the relationship between exposure levels and duration of exposures on the outcome of 1,3-butadiene-induced carcinogenicity. In these studies, lymphocytic lymphomas were induced in male mice exposed to 625 ppm 1,3-butadiene for only 13 weeks. The incidence of lymphocytic lymphoma in male mice exposed to 625 ppm 1,3-butadiene for 26 weeks was two times that in mice exposed to 625 ppm for 13 weeks. However, when the exposure concentration was reduced by half to 312 ppm and the exposure duration extended to 52 weeks, the

  6. Early treatment of acute submacular haemorrhage secondary to wet AMD using intravitreal tissue plasminogen activator, C3F8, and an anti-VEGF agent.

    PubMed

    de Silva, S R; Bindra, M S

    2016-07-01

    PurposeAcute submacular haemorrhage secondary to wet age-related macular degeneration (AMD) has a poor prognosis for which there is currently no 'gold standard' treatment. We evaluated the efficacy of early treatment using intravitreal triple therapy of tissue plasminogen activator (tPA), expansile gas, and an anti-VEGF agent.MethodsThis retrospective case series included eight patients presenting with acute submacular haemorrhage involving the fovea. All patients received treatment with 50 μg (0.05 ml) tPA, 0.3 ml 100% perfluoropropane (C3F8), and an anti-VEGF agent (0.05 mg Ranibizumab or 1.25 mg Bevacizumab in 0.05 ml) administered via intravitreal injection. An anterior chamber paracentesis post injection or vitreous tap was performed before injection to prevent retinal vascular occlusion secondary to raised intra-ocular pressure. Outcomes assessed were visual acuity, change in macular morphology, and complications.ResultsPatients presented promptly with delay between symptom onset and clinic review being 1.9±0.6 days (mean±SD). Treatment was delivered quickly with interval from presentation to treatment being 1.1±1.2 days. Symptom onset to treatment was 3.0±1.0 days. Subfoveal haemorrhage was effectively displaced in all patients. LogMAR visual acuity improved from 1.67±0.47 at presentation to 0.63±0.33 at final follow-up (P<0.0001), a mean of 7.9±4.8 months after treatment. Central retinal thickness improved from 658.1±174.2 μm at presentation to 316.6±142.4 μm at final follow-up (P=0.0028).ConclusionsEarly treatment of submacular haemorrhage using intravitreal tPA, C3F8, and anti-VEGF was effective in significantly improving visual acuity in this series of patients who presented soon after symptom onset. Treatment was well tolerated in this group of elderly and potentially frail patients. PMID:27080482

  7. Carcinogenesis Bioassay of 11-Aminoundecanoic Acid (CAS No. 2432-99-7) in F344 Rats and B6C3F1 Mice.

    PubMed

    1982-05-01

    11-Aminoundecanoic acid is the monomer used in the manufacture of the polyamide, nylon-11. Aminoundecanoic acid is synthesized through a series of reactions from ricinoleic acid isolated from castor bean oil. Nylon-11 is used in automobile parts, industrial fabrics (e.g. filter bags, work clothes, and netting), and brushes because of its resistance to vibration and shock and its stability when in contact with fuels. Nylon-11 resins are approved by the U.S. Food and Drug Administration for use on food contact films. A carcinogenesis bioassay of 11-aminoundecanoic acid was carried out by administering diets containing 7,500 or 15,000 ppm of 11-aminoundecanoic acid to F344 rats and B6C3F1 mice. Groups of 50 rats and 50 mice of either sex were administered the test chemical for 104 weeks (rats) or 103 weeks (mice). Controls consisted of 50 untreated rats and 50 untreated mice of each sex. Nonneoplastic effects included dose-related decreases in mean body weight gain and survival for male rats and for mice of each sex; a dose-related increased incidence of hyperplasia of the transitional epithelium of the kidney and urinary bladder in rats of each sex; and mineralization of the kidney in dosed mice of each sex. Neoplastic nodules of the liver in dosed male rats (control 1/50, 2%; low dose 9/50, 18%; high dose 8/50, 16%; P<0.01) and transitional-cell carcinomas of the urinary bladder in high-dose male rats (control 0/48, 0%; low dose 0/48, 0%; high dose 7/49, 14%: P<0.01) were observed at significantly increased incidences compared with controls. Malignant lymphomas occurred at a significantly (P<0.05) increased rate in low-dose male mice (control 2/50, 4%; low dose 9/50, 18%; high dose 4/50, 8%). Under the conditions of this bioassay, 11-aminoundecanoic acid was carcinogenic for male F344 rats, inducing neoplastic nodules in the liver and transitional-cell carcinomas in the urinary bladder. The test chemical was not carcinogenic for female F344 rats. No clear evidence

  8. Accurate ab initio potential energy surface, thermochemistry, and dynamics of the F- + CH3F SN2 and proton-abstraction reactions

    NASA Astrophysics Data System (ADS)

    Szabó, István; Telekes, Hajnalka; Czakó, Gábor

    2015-06-01

    We develop a full-dimensional global analytical potential energy surface (PES) for the F- + CH3F reaction by fitting about 50 000 energy points obtained by an explicitly correlated composite method based on the second-order Møller-Plesset perturbation-F12 and coupled-cluster singles, doubles, and perturbative triples-F12a methods and the cc-pVnZ-F12 [n = D, T] basis sets. The PES accurately describes the (a) back-side attack Walden inversion mechanism involving the pre- and post-reaction (b) ion-dipole and (c) hydrogen-bonded complexes, the configuration-retaining (d) front-side attack and (e) double-inversion substitution pathways, as well as (f) the proton-abstraction channel. The benchmark quality relative energies of all the important stationary points are computed using the focal-point analysis (FPA) approach considering electron correlation up to coupled-cluster singles, doubles, triples, and perturbative quadruples method, extrapolation to the complete basis set limit, core-valence correlation, and scalar relativistic effects. The FPA classical(adiabatic) barrier heights of (a), (d), and (e) are -0.45(-0.61), 46.07(45.16), and 29.18(26.07) kcal mol-1, respectively, the dissociation energies of (b) and (c) are 13.81(13.56) and 13.73(13.52) kcal mol-1, respectively, and the endothermicity of (f) is 42.54(38.11) kcal mol-1. Quasiclassical trajectory computations of cross sections, scattering (θ) and initial attack (α) angle distributions, as well as translational and internal energy distributions are performed for the F- + CH3F(v = 0) reaction using the new PES. Apart from low collision energies (Ecoll), the SN2 excitation function is nearly constant, the abstraction cross sections rapidly increase with Ecoll from a threshold of ˜40 kcal mol-1, and retention trajectories via double inversion are found above Ecoll = ˜ 30 kcal mol-1, and at Ecoll = ˜ 50 kcal mol-1, the front-side attack cross sections start to increase very rapidly. At low Ecoll, the

  9. Accurate ab initio potential energy surface, thermochemistry, and dynamics of the F(-) + CH3F SN2 and proton-abstraction reactions.

    PubMed

    Szabó, István; Telekes, Hajnalka; Czakó, Gábor

    2015-06-28

    We develop a full-dimensional global analytical potential energy surface (PES) for the F(-) + CH3F reaction by fitting about 50 000 energy points obtained by an explicitly correlated composite method based on the second-order Møller-Plesset perturbation-F12 and coupled-cluster singles, doubles, and perturbative triples-F12a methods and the cc-pVnZ-F12 [n = D, T] basis sets. The PES accurately describes the (a) back-side attack Walden inversion mechanism involving the pre- and post-reaction (b) ion-dipole and (c) hydrogen-bonded complexes, the configuration-retaining (d) front-side attack and (e) double-inversion substitution pathways, as well as (f) the proton-abstraction channel. The benchmark quality relative energies of all the important stationary points are computed using the focal-point analysis (FPA) approach considering electron correlation up to coupled-cluster singles, doubles, triples, and perturbative quadruples method, extrapolation to the complete basis set limit, core-valence correlation, and scalar relativistic effects. The FPA classical(adiabatic) barrier heights of (a), (d), and (e) are -0.45(-0.61), 46.07(45.16), and 29.18(26.07) kcal mol(-1), respectively, the dissociation energies of (b) and (c) are 13.81(13.56) and 13.73(13.52) kcal mol(-1), respectively, and the endothermicity of (f) is 42.54(38.11) kcal mol(-1). Quasiclassical trajectory computations of cross sections, scattering (θ) and initial attack (α) angle distributions, as well as translational and internal energy distributions are performed for the F(-) + CH3F(v = 0) reaction using the new PES. Apart from low collision energies (Ecoll), the SN2 excitation function is nearly constant, the abstraction cross sections rapidly increase with Ecoll from a threshold of ∼40 kcal mol(-1), and retention trajectories via double inversion are found above Ecoll = ∼ 30 kcal mol(-1), and at Ecoll = ∼ 50 kcal mol(-1), the front-side attack cross sections start to increase very rapidly. At

  10. Discovery of new [1,4]dioxino[2,3-f]quinazoline-based inhibitors of EGFR including the T790M/L858R mutant.

    PubMed

    Qin, Xuemei; Li, Zhipeng; Yang, Leifu; Liu, Peng; Hu, Liming; Zeng, Chengchu; Pan, Zhiyong

    2016-07-01

    A novel series of 2,3-dihydro-[1,4]dioxino[2,3-f]quinazoline derivatives were designed, synthesized and evaluated as reversible and noncovalent epidermal growth factor receptor (EGFR) inhibitors. Most of the compounds exhibited good potency against EGFR(wt) and some showed moderate to excellent potency against EGFR(T790M/L858R) mutant. The half-maximal inhibitory concentration (IC50) values of twenty-one compounds against EGFR(wt) were less than 50nM, and those of six compounds were less than 10nM. The IC50 values of eleven compounds against EGFR(T790M/L858R) were less than 100nM. Among these, compound b1 displayed the most potent inhibitory activity against EGFR(wt) (IC50=2.0nM) and EGFR(T790M/L858R) (IC50=6.9nM). Compounds with excellent inhibitory activities against EGFR(wt) and EGFR(T790M/L858R) kinase inhibitory activities showed good antiproliferative activities against H358 and A549 cells. Docking study was performed to position compound b1 into the EGFR active pocket to determine the probable binding conformation. PMID:27234887

  11. Wind-Tunnel Tests of a 1/8-Scale Powered Model of the XTB3F-1 Airplane, TED No. NACA 2382

    NASA Technical Reports Server (NTRS)

    McKee, John W.; Vogler, Raymond D.

    1947-01-01

    A 1/8 scale model of the Grumman XTB3F-1 airplane was tested in the Langley 7- by 10-foot tunnel to determine the stability and control characteristics and to provide data for estimating the airplane handling qualities. The report includes longitudinal and lateral stability and control characteristics of the complete model, the characteristics of the isolated horizontal tail, the effects of various flow conditions through the jet duct, tests with external stores attached to the underside of the wing, ana tests simulating landing and take-off conditions with a ground board. The handling characteristics of the airplane have not been computed but some conclusions were indicated by the data. An improvement in the longitudinal stability was obtained by tilting the thrust line down. It is shown that if the wing flap is spring loaded so that the flap deflection varies with airspeed, the airplanes will be less stable than with the flap retracted or fully deflected. An increase in size of the vertical tail and of the dorsal fin gave more desirable yawing-moment characteristics than the original vertical tail and dorsal fin. Preventing air flow through the jet duct system or simulating jet operation with unheated air produced only small changes in the model characteristics. The external stores on the underside of the wing had only small effects on the model characteristics. After completion of the investigation, the model was returned to the contractor for modifications indicated by the test results.

  12. Synthesis and crystal structure of two tin fluoride materials: NaSnF 3 (BING-12) and Sn 3F 3PO 4

    NASA Astrophysics Data System (ADS)

    Salami, Tolulope O.; Zavalij, Peter Y.; Oliver, Scott R. J.

    2004-03-01

    A new compound, sodium tin trifluoride (NaSnF 3, which we denote BING-12 for SUNY at Binghamton, Structure No. 12), was synthesized solvothermally from a pyridine-water solvent system. The new compound crystallized in the monoclinic space group C2/ c (No. 15), with a=11.7429(12) Å, b=17.0104(18) Å, c=6.8528(7) Å, β=100.6969(2)°, V=1345.1(2) Å 3 and Z=16. The layered structure consists of outer pyramidal SnF 3 units, where the fluorides surround a central layer of six- and seven-coordinate sodium atoms. The layers are stabilized by charged Na + galleries that reside in the center of the layers. Tin trifluorophosphate (Sn 3F 3PO 4, Compound 2) was isolated from a related synthetic system, and crystallized in the rhombohedral space group R3 (No. 146), with a=11.8647(11) Å, c=4.6291(6) Å, V=564.34(10) Å 3 and Z=3. The framework is made up of helical -Sn-F- chains, which are connected by phosphate groups. The materials were characterized by powder X-ray diffraction (PXRD), variable temperature PXRD (VT-PXRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM).

  13. SiN etching characteristics of Ar/CH3F/O2 plasma and dependence on SiN film density

    NASA Astrophysics Data System (ADS)

    Ohtake, Hiroto; Wanifuchi, Tomiko; Sasaki, Masaru

    2016-08-01

    We evaluated the silicon nitride (SiN) etching characteristics of Ar/O2/hydrofluorocarbon plasma. Ar/CH3F/O2 plasma achieved a high etching selectivity of SiN to SiO2 by increasing the oxygen flow rate. We also evaluated the dependence of SiN etching characteristics on SiN film density. A low-density film deposited at a low temperature of 200 °C (by plasma-enhanced CVD, PECVD) showed an 8–20% lower etching rate of SiN than a high-density film deposited at a high temperature of 780 °C (by low-pressure CVD, LPCVD) when we had a low RF bias of 30 W. This PECVD film might move the competitive balance to oxidation from fluorination, reducing the SiN etching rate. However, when we have a high RF bias of more than 50 W, the SiN etching rate is 2–15% higher in the PECVD film than in t