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Sample records for zn23 ca5 pd2

  1. 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.

  2. CePd2Ga3 and CePd2Zn3 - Kondo lattices and magnetic behaviour

    NASA Astrophysics Data System (ADS)

    Bartha, A.; Vališka, M.; Míšek, M.; Proschek, P.; Kaštil, J.; Dušek, M.; Sechovský, V.; Prokleška, J.

    2018-05-01

    We report the single crystal properties of CePd2Zn3 and CePd2Ga3 compounds. The compounds were prepared by Bridgman method in high-frequency induction furnace. Both compounds adopt the hexagonal PrNi2Al3-type structure with a = 5.3914(2) Å, c = 4.3012(2) Å for CePd2Zn3 and a = 5.4106(8) Å, c = 4.2671(8) Å for CePd2Ga3, respectively. CePd2Zn3 orders antiferromagnetically below TN = 1.9 K. Magnetoresistance measurements revealed a crossover at Bc = 0.95 T. CePd2Ga3 orders ferromagnetically at TC = 6.7 K. Applied hydrostatic pressure reduces the value of the Curie-temperature (rate ∂TC / ∂ p = 0.9 K GPa -1) down to 3.9 K at 3.2 GPa. Both compounds display a strong magnetocrystalline anisotropy with easy axis of magnetization perpendicular to the c-axis in the hexagonal lattice.

  3. Superconductivity in ThPd2Ge2

    NASA Astrophysics Data System (ADS)

    Domieracki, Krzysztof; Wiśniewski, Piotr; Wochowski, Konrad; Romanova, Tetiana; Hackemer, Alicja; Gorzelniak, Roman; Pikul, Adam; Kaczorowski, Dariusz

    2018-05-01

    Our on-going search for unconventional superconductors among the ThTE2Ge2 phases (TE is a d-electron transition metal) revealed that ThPd2Ge2, which crystallizes with a body-centered tetragonal ThCr2Si2-type structure, exhibits superconductivity at low temperatures. In this paper, we report on the electrical transport and thermodynamic properties of a polycrystalline sample of this new superconductor, extended down to 50 mK. The experimental data indicates weakly-coupled type-II superconductivity with Tc = 0.63(2) K and μ0Hc2(0) = 32(2) mT.

  4. Magnetic and structural instabilities in CePd 2Al 2 and LaPd 2Al 2

    NASA Astrophysics Data System (ADS)

    Chapon, L. C.; Goremychkin, E. A.; Osborn, R.; Rainford, B. D.; Short, S.

    2006-05-01

    We have investigated the crystal and magnetic structure of the RPd 2Al 2 compounds (R=La, Ce) by neutron powder diffraction (ND) and inelastic neutron scattering (INS). The ND study shows that both compounds undergo a structural phase transition from tetragonal to orthorhombic symmetry at 91.5 K (La) and 13.5 K (Ce). In the case of CePd 2Al 2 the crystal field excitation spectrum, which has an extra peak that cannot be explained by a standard crystal field model, indicates the presence of strong magneto-elastic coupling.

  5. Highly selective and reversible chemosensor for Pd(2+) detected by fluorescence, colorimetry, and test paper.

    PubMed

    Wang, Mian; Liu, Xiaomei; Lu, Huizhe; Wang, Hongmei; Qin, Zhaohai

    2015-01-21

    A "turn-on" fluorescent and colorimetric chemosensor (RBS) for Pd(2+) has been designed and synthesized through introduction of sulfur as a ligand atom to Rhodamine B. RBS exhibits high selectivity (freedom from the interference of Hg(2+ )in particular) and sensitivity toward Pd(2+) with a detection limit as low as 2.4 nM. RBS is also a reversible sensor, and it can be made into test paper to detect Pd(2+) in pure water. Compared to the chemosensors that introduced phosphorus to Rhodamine to detect Pd(2+), RBS can be synthesized more simply and economically.

  6. Antibonding Holes Induce Good Thermoelectric Properties of p-type Ca5Ga2As6

    NASA Astrophysics Data System (ADS)

    Yu, Qingxiu; Wang, Yuan Xu; Shao, Hehong

    2017-07-01

    The arrangement of anionic tetrahedra in Zintl compounds plays a key role in determining their thermoelectric properties. We manifest this idea by investigating the crystal structure, electronic structure, and thermoelectric properties of the Zintl compounds Ca3GaAs3 and Ca5Ga2As6. By comparing various properties of Ca3GaAs3 and Ca5Ga2As6, we found that with decreasing calcium content from Ca3GaAs3 to Ca5Ga2As6, the two adjacent covalent chains formed by GaAs4 tetrahedra are connected by As-As bonds. In Ca5Ga2As6, the appearance of such As-As bonds not only supports the charge balance but also provides two nearly degenerate bands at the top of its valence bands. These two bands determine the thermoelectric behavior of p-type Ca5Ga2As6. The calculated band-decomposed charge density shows that the two bands have a π* antibonding feature of the As pz orbital. Our calculations also reveal that the formation or non-formation of As-As bonds plays an important role in the difference in the thermoelectric properties between Ca3GaAs3 and Ca5Ga2As6. The optimal carrier concentration for achieving the highest thermoelectric performance was explored by calculating the trends in their thermoelectric properties with the carrier concentration. Our work may stimulate further experimental and theoretical work to increase understanding of Zintl chemistry and improve the thermoelectric performance of Zintl compounds.

  7. Synthesis, Structure, and Thermal Properties of Ca5Ga6O14

    NASA Astrophysics Data System (ADS)

    Tolkacheva, A. S.; Shkerin, S. N.; Kuzmin, A. V.; Plaksin, S. V.; Korzun, I. V.; Kochedykov, V. A.; Yaroslavtseva, T. V.; Vovkotrub, E. G.

    2018-07-01

    Calcium gallate Ca5Ga6O14 is synthesized by solid-phase means. Its melting point is 1325 ± 2°C. A phase transition of the second kind is observed in the temperature interval of 750-800°C. The temperature dependence of a thermal linear expansion coefficient within 200-900°C is given. Vibrational spectroscopy data confirm that Ca5Ga6O14 contains not only GaO4 tetrahedra but also GaO6 octahedra.

  8. Thermoelectric properties of the Ca(5)Al(2-x)In(x)Sb(6) solid solution.

    PubMed

    Zevalkink, Alex; Swallow, Jessica; Ohno, Saneyuki; Aydemir, Umut; Bux, Sabah; Snyder, G Jeffrey

    2014-11-14

    Zintl phases are attractive for thermoelectric applications due to their complex structures and bonding environments. The Zintl compounds Ca(5)Al(2)In(x)Sb(6)and Ca(5)Al(2)In(x)Sb(6) have both been shown to have promising thermoelectric properties, with zT values of 0.6 and 0.7, respectively, when doped to control the carrier concentration. Alloying can often be used to further improve thermoelectric materials in cases when the decrease in lattice thermal conductivity outweighs reductions to the electronic mobility. Here we present the high temperature thermoelectric properties of the Ca(5)Al(2-x)In(x)Sb(6)solid solution. Undoped and optimally Zn-doped samples were investigated. X-ray diffraction confirms that a full solid solution exists between the Al and In end-members. We find that the Al : In ratio does not greatly influence the carrier concentration or Seebeck effect. The primary effect of alloying is thus increased scattering of both charge carriers and phonons, leading to significantly reduced electronic mobility and lattice thermal conductivity at room temperature. Ultimately, the figure of merit is unaffected by alloying in this system, due to the competing effects of reduced mobility and lattice thermal conductivity.

  9. Open innovation for phenotypic drug discovery: The PD2 assay panel.

    PubMed

    Lee, Jonathan A; Chu, Shaoyou; Willard, Francis S; Cox, Karen L; Sells Galvin, Rachelle J; Peery, Robert B; Oliver, Sarah E; Oler, Jennifer; Meredith, Tamika D; Heidler, Steven A; Gough, Wendy H; Husain, Saba; Palkowitz, Alan D; Moxham, Christopher M

    2011-07-01

    Phenotypic lead generation strategies seek to identify compounds that modulate complex, physiologically relevant systems, an approach that is complementary to traditional, target-directed strategies. Unlike gene-specific assays, phenotypic assays interrogate multiple molecular targets and signaling pathways in a target "agnostic" fashion, which may reveal novel functions for well-studied proteins and discover new pathways of therapeutic value. Significantly, existing compound libraries may not have sufficient chemical diversity to fully leverage a phenotypic strategy. To address this issue, Eli Lilly and Company launched the Phenotypic Drug Discovery Initiative (PD(2)), a model of open innovation whereby external research groups can submit compounds for testing in a panel of Lilly phenotypic assays. This communication describes the statistical validation, operations, and initial screening results from the first PD(2) assay panel. Analysis of PD(2) submissions indicates that chemical diversity from open source collaborations complements internal sources. Screening results for the first 4691 compounds submitted to PD(2) have confirmed hit rates from 1.6% to 10%, with the majority of active compounds exhibiting acceptable potency and selectivity. Phenotypic lead generation strategies, in conjunction with novel chemical diversity obtained via open-source initiatives such as PD(2), may provide a means to identify compounds that modulate biology by novel mechanisms and expand the innovation potential of drug discovery.

  10. Czochralski growth of LaPd2Al2 single crystals

    NASA Astrophysics Data System (ADS)

    Doležal, P.; Rudajevová, A.; Vlášková, K.; Kriegner, D.; Václavová, K.; Prchal, J.; Javorský, P.

    2017-10-01

    The present study is focused on the preparation of single crystalline LaPd2Al2 by the Czochralski method. Differential scanning calorimetry (DSC) and energy dispersive X-ray spectroscopy (EDX) analyses reveal that LaPd2Al2 is an incongruently melting phase which causes difficulties for the preparation of single crystalline LaPd2Al2 by the Czochralski method. Therefore several non-stoichiometric polycrystalline samples were studied for its preparation. Finally the successful growth of LaPd2Al2 without foreign phases has been achieved by using a non-stoichiometric precursor with atomic composition 22:39:39 (La:Pd:Al). X-ray powder diffraction, EDX analysis and DSC were used for the characterisation. A single crystalline sample was separated from the ingot prepared by the Czochralski method using the non-stoichiometric precursor. The presented procedure for the preparation of pure single phase LaPd2Al2 could be modified for other incongruently melting phases.

  11. Mechanical properties and in vitro bioactivity of Ca5(PO4)2SiO4 bioceramic.

    PubMed

    Lu, Wenhao; Duan, Wei; Guo, Yaping; Ning, Congqin

    2012-02-01

    Pure Ca(5)(PO(4))(2)SiO(4) bioceramic was first prepared by a sol-gel method using triethyl phosphate, tetraethoxysilane, and calcium nitrate tetrahydrate as original materials. Simulated body fluid (SBF) immersion tests revealed that Ca(5)(PO(4))(2)SiO(4) samples had a greater in vitro apatite-forming ability than hydroxyapatite (HA). After soaking Ca(5)(PO(4))(2)SiO(4) samples in the SBF for 1 day, bone-like apatite precipitated on the surfaces and the apatite layer became thicker with increasing the soaking time. However, few bone-like apatites precipitated on the HA samples even after soaking in the SBF for 7 days. The good in vitro bioactivity of Ca(5)(PO(4))(2)SiO(4) samples was attributed to the silanol (Si-OH) groups and greater solubility of Ca(5)(PO(4))(2)SiO(4). In addition, hot-pressed Ca(5)(PO(4))(2)SiO(4) ceramic exhibited lower bending strength and elastic modulus than hot-pressed HA, since the former had a lower relative density than the latter. The results have shown that Ca(5)(PO(4))(2)SiO(4) is a potential candidate material for bone repair. © The Author(s), 2010.

  12. Posttest TRAC-PD2/MOD1 predictions for FLECHT SEASET test 31504. [PWR

    SciTech Connect

    Booker, C.P.

    TRAC-PD2/MOD1 is a publicly released version of TRAC that is used primarily to analyze large-break loss-of-coolant accidents in pressurized-water reactors (PWRs). TRAC-PD2 can calculate, among other things, reflood phenomena. TRAC posttest predictions are compared with test 31504 reflood data from the Full-Length Emergency Core Heat Transfer (FLECHT) System Effects and Separate Effects Tests (SEASET) facility. A false top-down quench is predicted near the top of the core and the subcooling is underpredicted at the bottom of the core. However, the overall TRAC predictions are good, especially near the center of the core.

  13. 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.

  14. An impurity intermediate band due to Pb doping induced promising thermoelectric performance of Ca5In2Sb6.

    PubMed

    Feng, Zhenzhen; Wang, Yuanxu; Yan, Yuli; Zhang, Guangbiao; Yang, Jueming; Zhang, Jihua; Wang, Chao

    2015-06-21

    Band engineering is one of the effective approaches for designing ideal thermoelectric materials. Introducing an intermediate band in the band gap of semiconducting thermoelectric compounds may largely increase the carrier concentration and improve the electrical conductivity of these compounds. We test this hypothesis by Pb doping in Zintl Ca5In2Sb6. In the current work, we have systematically investigated the electronic structure and thermoelectric performances of substitutional doping with Pb on In sites at a doping level of 5% (0.2 e per cell) for Ca5In2Sb6 by using density functional theory combined with semi-classical Boltzmann theory. It is found that in contrast to Zn doping, Pb doping introduces a partially filled intermediate band in the band gap of Ca5In2Sb6, which originates from the Pb s states by weakly hybridizing with the Sb p states. Such an intermediate band dramatically increases the electrical conductivity of Ca5In2Sb6 and has little detrimental effect on its Seebeck coefficient, which may increase its thermoelectric figure of merit, ZT. Interestingly, a maximum ZT value of 2.46 may be achieved at 900 K for crystalline Pb-doped Ca5In2Sb6 when the carrier concentration is optimized. Therefore, Pb-doped Ca5In2Sb6 may be a promising thermoelectric material.

  15. Quorum sensing of microalgae associated marine Ponticoccus sp. PD-2 and its algicidal function regulation.

    PubMed

    Chi, Wendan; Zheng, Li; He, Changfei; Han, Bin; Zheng, Minggang; Gao, Wei; Sun, Chengjun; Zhou, Gefei; Gao, Xiangxing

    2017-12-01

    Quorum sensing (QS) systems play important roles in regulating many physiological functions of microorganisms, such as biofilm formation, bioluminescence, and antibiotic production. One marine algicidal bacterium, Ponticoccus sp. PD-2, was isolated from the microalga Prorocentrum donghaiense, and its N-acyl-homoserine lactone (AHL)-mediated QS system was verified. In this study, we analyzed the AHLs profile of strain PD-2. Two AHLs, 3-oxo-C8-HSL and 3-oxo-C10-HSL, were detected using a biosensor overlay assay and GC-MS methods. Two complete AHL-QS systems (designated zlaI/R and zlbI/R) were identified in the genome of strain PD-2. When expressed in Escherichia coli, both zlaI and zlbI genes could each produce 3-oxo-C8-HSL and 3-oxo-C10-HSL. Algicidal activity was investigated by evaluating the inhibitory rate (IR) of microalgae growth by measuring the fluorescence of viable cells. We found that the metabolites of strain PD-2 had algicidal activity against its host P. donghaiense (IR 84.81%) and two other red tide microalgae, Phaeocystis globosa (IR 78.91%) and Alexandrium tamarense (IR 67.14%). β-cyclodextrin which binds to AHLs and inhibits the QS system reduced the algicidal activity more than 50%. This indicates that inhibiting the QS system may affect the algicidal metabolites production of strain PD-2. Our study indicated that a QS-regulated algicidal system may play a potential role in the process of red tides disintegration. QS might be a potential way to control red tides.

  16. Structural and electronic properties of LaPd2As2 superconductor: First-principle calculations

    NASA Astrophysics Data System (ADS)

    Singh, Birender; Kumar, Pradeep

    2017-05-01

    In present work we have studied electronic and structural properties of superconducting LaPd2As2 compound having collapsed tetragonal structure using first-principle calculations. The band structure calculations show that the LaPd2As2 is metallic consistent with the reported experimental observation, and the density of states plots clearly shows that at the Fermi level major contribution to density of states arises from Pd 4d and As 4p states, unlike the Fe-based superconductors where major contribution at the Fermi level comes from Fe 3d states. The estimated value of electron-phonon coupling is found to be 0.37, which gives the upper bound of superconducting transition temperature of 5K, suggesting the conventional nature of this superconductor.

  17. Superconductivity in LaPd2Al2-xGax compounds

    NASA Astrophysics Data System (ADS)

    Klicpera, M.; Pásztorová, J.; Javorský, P.

    2014-08-01

    The superconductivity in LaPd2Al2-xGax compounds was studied by means of electrical resistivity and specific heat measurements. The concentration development of the superconducting properties was revealed. The measured data deviate significantly from the Bardeen-Cooper-Schrieffer theory predictions and are discussed in the context of unconventional superconductivity. The electronic specific heat below {{T}_{SC}} follows almost quadratic temperature dependence, which might indicate an axial state with line nodes in the superconducting gap structure.

  18. NQRS Data for Ga3LaPd2 (Subst. No. 2229)

    NASA Astrophysics Data System (ADS)

    Chihara, H.; Nakamura, N.

    This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for Ga3LaPd2 (Subst. No. 2229)

  19. Ferromagnetic quantum critical point in CePd2P2 with Pd → Ni substitution

    NASA Astrophysics Data System (ADS)

    Lai, Y.; Bone, S. E.; Minasian, S.; Ferrier, M. G.; Lezama-Pacheco, J.; Mocko, V.; Ditter, A. S.; Kozimor, S. A.; Seidler, G. T.; Nelson, W. L.; Chiu, Y.-C.; Huang, K.; Potter, W.; Graf, D.; Albrecht-Schmitt, T. E.; Baumbach, R. E.

    2018-06-01

    An investigation of the structural, thermodynamic, and electronic transport properties of the isoelectronic chemical substitution series Ce (Pd1-xNix) 2P2 is reported, where a possible ferromagnetic quantum critical point is uncovered in the temperature-concentration (T -x ) phase diagram. This behavior results from the simultaneous contraction of the unit cell volume, which tunes the relative strengths of the Kondo and Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions, and the introduction of disorder through alloying. Near the critical region at xcr≈ 0.7, the rate of contraction of the unit cell volume strengthens, indicating that the cerium f valence crosses over from trivalent to a noninteger value. Consistent with this picture, x-ray absorption spectroscopy measurements reveal that while CePd2P2 has a purely trivalent cerium f state, CeNi2P2 has a small (<10 %) tetravalent contribution. In a broad region around xcr, there is a breakdown of Fermi-liquid temperature dependences, signaling the influence of quantum critical fluctuations and disorder effects. Measurements of clean CePd2P2 furthermore show that applied pressure has an initial effect similar to alloying on the ferromagnetic order. From these results, CePd2P2 emerges as a keystone system to test theories such as the Belitz-Kirkpatrick-Vojta model for ferromagnetic quantum criticality, where distinct behaviors are expected in the dirty and clean limits.

  20. The New Superconductor tP-SrPd2Bi2: Structural Polymorphism and Superconductivity in Intermetallics.

    PubMed

    Xie, Weiwei; Seibel, Elizabeth M; Cava, Robert J

    2016-04-04

    We consider a system where structural polymorphism suggests the possible existence of superconductivity through the implied structural instability. SrPd2Bi2 has two polymorphs, which can be controlled by the synthesis temperature: a tetragonal form (CaBe2Ge2-type) and a monoclinic form (BaAu2Sb2-type). Although the crystallographic difference between the two forms may, at first, seem trivial, we show that tetragonal SrPd2Bi2 is superconducting at 2.0 K, whereas monoclinic SrPd2Bi2 is not. We rationalize this finding and place it in context with other 1-2-2 phases.

  1. Surface reactivity and hydroxyapatite formation on Ca5MgSi3O12 ceramics in simulated body fluid

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Wang, Yaorong; Huang, Yanlin; Cheng, Han; Seo, Hyo Jin

    2017-11-01

    In this work, the new calcium-magnesium-silicate Ca5MgSi3O12 ceramic was made via traditional solid-state reaction. The bioactivities were investigated by immerging the as-made ceramics in simulated body fluid (SBF) for different time at body temperature (37 °C). Then the samples were taken to measure X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), X-ray energy-dispersive spectra (EDS), and Fourier transform infrared spectroscopy (FT-IR) measurements. The bone-like hydroxyapatite nanoparticles formation was observed on the ceramic surfaces after the immersion in SBF solutions. Ca5MgSi3O12 ceramics possess the Young's modulus and the bending strength and of 96.3 ± 1.2 GPa and 98.7 ± 2.3 MPa, respectively. The data suggest that Ca5MgSi3O12 ceramics can quickly induce HA new layers after soaking in SBF. Ca5MgSi3O12 ceramics are potential to be used as biomaterials for bone-tissue repair. The cell adherence and proliferation experiments are conducted confirming the reliability of the ceramics as a potential candidate.

  2. Selective and sensitive fluorescent sensor for Pd2+ using coumarin 460 for real-time and biological applications.

    PubMed

    Ashwin, Bosco Christin Maria Arputham; Sivaraman, Gandhi; Stalin, Thambusamy; Yuvakkumar, Rathinam; Muthu Mareeswaran, Paulpandian

    2018-06-01

    The efficient fluorescent property of coumarin 460 (C460) is utilized to sense the Pd 2+ selectively and sensitively. Fabrication of a sensor strip using commercial adhesive tape is achieved and the detection of Pd 2+ is attempted using a handy UV torch. The naked eye detection in solution state using UV chamber is also attempted. The calculated high binding constant values support the strong stable complex formation of Pd 2+ with C460. The detection limit up to 2.5 × 10 -7  M is achieved using fluorescence spectrometer, which is considerably low from the WHO's recommendation. The response of coumarin 460 with various cations also studied. The quenching is further studied by the lifetime measurements. The binding mechanism is clearly explained by the 1 H NMR titration. The sensing mechanism is established as ICT. C460 strip's Pd 2+ quenching detection is further confirmed by solid-state PL study. The in-vitro response of Pd 2+ in a living cell is also studied using fluorescent imaging studies by means of HeLa cell lines and this probe is very compatible with biological environments. It could be applicable to sense trace amounts of a Pd 2+ ion from various industries. Compared with previous reports, this one is very cheap, sensitive, selective and suitable for biological systems. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. PD2P: PanDA Dynamic Data Placement for ATLAS

    SciTech Connect

    Maeno, T.; De, K.; Panitkin, S.

    2012-12-13

    The PanDA (Production and Distributed Analysis) system plays a key role in the ATLAS distributed computing infrastructure. PanDA is the ATLAS workload management system for processing all Monte-Carlo (MC) simulation and data reprocessing jobs in addition to user and group analysis jobs. The PanDA Dynamic Data Placement (PD2P) system has been developed to cope with difficulties of data placement for ATLAS. We will describe the design of the new system, its performance during the past year of data taking, dramatic improvements it has brought about in the efficient use of storage and processing resources, and plans for the future.

  4. An inert marker study for palladium silicide formation - Si moves in polycrystalline Pd2Si

    NASA Technical Reports Server (NTRS)

    Ho, K. T.; Lien, C.-D.; Shreter, U.; Nicolet, M.-A.

    1985-01-01

    A novel use of Ti marker is introduced to investigate the moving species during Pd2Si formation on 111 and 100 line-type Si substrates. Silicide formed from amorphous Si is also studied using a W marker. Although these markers are observed to alter the silicide formation in the initial stage, the moving species can be identified once a normal growth rate is resumed. It is found that Si is the dominant moving species for all three types of Si crystallinity. However, Pd will participate in mass transport when Si motion becomes obstructed.

  5. Two-dimensional PdSe2-Pd2Se3 junctions can serve as nanowires

    NASA Astrophysics Data System (ADS)

    Zuluaga, Sebastian; Lin, Junhao; Suenaga, Kazu; Pantelides, Sokrates T.

    2018-07-01

    While the exfoliation of almost all layered materials results in a monolayer with the same atomic geometry as its bulk counterpart, the exfoliation of PdSe2 results in a monolayer with a different atomic geometry and a new stoichiometry, Pd2Se3, which is a fusion of two PdSe2 monolayers mediated by Se emission. Here we first report first-principles calculations of lateral junctions between a PdSe2 bilayer and a Pd2Se3 monolayer. We find that, while several distinct junction geometries are possible, they all exhibit empty interface states below the conduction band. As a result, light n-type doping of either or both sides, e.g. by halogen atoms replacing Se atoms, leads to a remotely-doped interface, i.e. a 1D conducting nanowire that runs along the junction, in between the two semiconductors. We have fabricated such junctions inside a scanning transmission electron microscope (STEM), but doping and transport measurements are not currently practical.

  6. Magnetic properties and large reversible magnetocaloric effect in Er3Pd2

    NASA Astrophysics Data System (ADS)

    Maji, Bibekananda; Ray, Mayukh K.; Modak, M.; Mondal, S.; Suresh, K. G.; Banerjee, S.

    2018-06-01

    The magnetic properties and magnetocaloric effect (MCE) of binary intermetallic compound Er3Pd2 were studied. It exhibits a paramagnetic (PM) to antiferromagnetic (AFM) transition at Néel temperature (TN) = 10 K. A large reversible MCE was observed which is related to a second order magnetic transition from PM to AFM state. The values of maximum magnetic entropy change (- Δ SMmax) and adiabatic temperature change (Δ Tadmax) reach 8.9 J/kg-K and 2.9 K respectively for the field change of 50 kOe with no obvious hysteresis loss. The effective magnetic moment was determined to be 10.16 μB/Er3+, which is notably higher than that of free ion value of Er3+ (9.59 μB), suggests that Pd ions also have considerable amount of magnetic moments in this compound.

  7. Current transport in Pd2Si/n-Si(100) Schottky barrier diodes at low temperatures

    NASA Astrophysics Data System (ADS)

    Chand, Subhash; Kumar, Jitendra

    1996-08-01

    The forward current-voltage ( I V) characteristics of Pd2Si/n-Si(100) Schottky barrier diodes are shown to follow the Thermionic Emission-Diffusion (TED) mechanism in the temperature range of 52-295 K. The evaluation of the experimental I V data reveals a decrease of the zero-bias barrier height (ϕ b0) and an increase of the ideality factor (η) with decreasing temperature. Further, the changes in ϕ b0 and η become quite significant below 148 K. It is demonstrated that the findings cannot be explained on the basis of tunneling, generation-recombination and/or image force lowering. Also, the concepts of flat band barrier height and “ T 0-effect” fail to account for the temperature dependence of the barrier parameters. The 1n( I s / T 2) vs 1/ T plot exhibits nonlinearity below 185 K with the linear portion corresponding to an activat ion energy of 0.64 eV, a value smaller than the zero-bias barrier height energy (0.735 eV) of Pd2Si/n-Si Schottky diodes. Similarly, the value of the effective Richardson constant A** turns out to be 1.17 × 104 A m-2 K-2 against the theoretical value of 1.12 × 106 A m-2 K-2. Finally, it is demonstrated that the observed trends result due to barrier height inhomogeneities prevailing at the interface which, in turn, cause extra current such that the I V characteristics continue to remain consistent with the TED process even at low temperatures. The inhomogeneities are believed to have a Gaussian distribution with a mean barrier height of 0.80 V and a standard deviation of 0.05 V at zero-bias. Also, the effect of bias is shown to homogenize barrier heights at a slightly higher mean value.

  8. [Promotion effects of vitamin B12 on the degradation of 2, 4, 4'-trichlorobiphenyl by Nostoc PD-2].

    PubMed

    Liu, Jia-Yu; Xiao, Wen-Feng; Lu, Li-Ping; Zhang, Hang-Jun

    2014-08-01

    Polychlorinated biphenyls are typical persistent chlorinated organic compounds in the environment. Bioremediation of PCB-contaminated environment has become one of the hot issues. In this study, vitamin B12 (VB12) and chlorine-free culture medium were applied to study the effects of VB12 on the degradation of 2,4,4'-trichlorobiphenyl (PCB28) by Nostoc PD-2 and the gene expression during the PCB-degradation process. Results showed that addition of different concentrations of vitamin B12 could improve the PCB-biodegradation rates by Nostoc PD-2. Compared with the control group, the 7-day degradation rate in 10 microg x L(-1), 100 microg x L(-1), and 1 000 microg x L(-1) VB12-treated groups increased by 11.0%, 19.7%, and 21.9% , respectively. The degradation half-time decreased from 5.53 days (treated with 10 microg x L(-1) VB12) to 3.08 days (treated with 100 microg x L(-1) VB12). The expression of cytochrome b6f complex iron-sulfur protein gene and dioxygenase gene showed significant correlation with PCB28-degradation by Nostoc PD-2. While the expression of iron-sulfur protein gene showed more significant correlation with PCB28-degradation. Results in this study indicated that adding VB12 could promote PCB28-degradation by Nostoc PD-2. Moreover, VB12 addition improved the PCB-degradation activity of Nostoc PD-2 at the gene level. The above conclusions could provide a new choice for developing efficient bioremediation technology for PCB-contaminated environment and a new insight into the PCB-biodegradation mechanism by Nostoc PD-2.

  9. Magnetic structures and excitations in CePd2(Al,Ga)2 series: Development of the "vibron" states

    NASA Astrophysics Data System (ADS)

    Klicpera, M.; Boehm, M.; Doležal, P.; Mutka, H.; Koza, M. M.; Rols, S.; Adroja, D. T.; Puente Orench, I.; Rodríguez-Carvajal, J.; Javorský, P.

    2017-02-01

    CePd2Al2 -xGax compounds crystallizing in the tetragonal CaBe2Ge2 -type structure (space group P 4 /n m m ) and undergoing a structural phase transition to an orthorhombic structure (C m m e ) at low temperatures were studied by means of neutron scattering. The amplitude-modulated magnetic structure of CePd2Al2 is described by an incommensurate propagation vector k ⃗=(δx,1/2 +δy,0 ) with δx=0.06 and δy=0.04 . The magnetic moments order antiferromagnetically within the a b planes stacked along the c axis and are arranged along the direction close to the orthorhombic a axis with a maximum value of 1.5(1) μB/Ce3 +. CePd2Ga2 reveals a magnetic structure composed of two components: the first is described by the propagation vector k1⃗=(1/2 ,1/2 ,0 ) , and the second one propagates with k2⃗=(0 ,1/2 ,0 ) . The magnetic moments of both components are aligned along the same direction—the orthorhombic [100] direction—and their total amplitude varies depending on the mutual phase of magnetic moment components on each Ce site. The propagation vectors k1⃗ and k2⃗ describe also the magnetic structure of substituted CePd2Al2 -xGax compounds, except the one with x =0.1 .CePd2Al1.9Ga0.1 with magnetic structure described by k ⃗ and k1⃗ stays on the border between pure CePd2Al2 and the rest of the series. Determined magnetic structures are compared with other Ce 112 compounds. Inelastic neutron scattering experiments disclosed three nondispersive magnetic excitations in the paramagnetic state of CePd2Al2 , while only two crystal field (CF) excitations are expected from the splitting of ground state J =5/2 of the Ce3 + ion in a tetragonal/orthorhombic point symmetry. Three magnetic excitations at 1.4, 7.8, and 15.9 meV are observed in the tetragonal phase of CePd2Al2 . A structural phase transition to an orthorhombic structure shifts the first excitation up to 3.7 meV, while the other two excitations remain at almost the same energy. The presence of an additional

  10. Glassy vortex behavior in superconducting SrPd2Ge2 single crystals

    NASA Astrophysics Data System (ADS)

    Sung, N. H.; Jo, Y. J.; Cho, B. K.

    2012-07-01

    In this study we report the vortex-glass behavior of superconducting ternary germanide SrPd2Ge2 single crystals with a ThCr2Si2-type structure. We observed flux trapping and its nonexponential decay with time after the magnetic field was turned off at T = 2 K. In addition, we found that the diamagnetism in the zero field cooling (ZFC) mode below Tc was irreversible, depending on the temperature and field history, whereas the diamagnetism in the field-cooled warming (FCW) mode was reversible if the applied magnetic field was parallel to the c-axis. An irreversibility line Tr(H) was determined by the ZFC and FCW measurements at various magnetic fields, and the temperature dependence of Tr(H) was found to agree with the de Almeida-Thouless relation, H = H0[1-Tr(H)/Tc(0)]γ, where γ = 3/2. Including these vortex-glass behaviors, we discuss the critical current density, Jc(T), determined from isothermal magnetization measurements at various temperatures, and the pinning potential, determined from the slope of an Arrhenius plot, lnR(T,B) versus 1/T.

  11. Superconductivity and anomalous normal state in the CePd 2Si 2/CeNi 2Ge 2 system

    NASA Astrophysics Data System (ADS)

    Grosche, F. M.; Lister, S. J. S.; Carter, F. V.; Saxena, S. S.; Haselwimmer, R. K. W.; Mathur, N. D.; Julian, S. R.; Lonzarich, G. G.

    1997-02-01

    The unconventional nonmagnetic metal CeNi 2Ge 2 is characterised at ambient pressure by temperature dependences of the specific heat and of the resistivity which deviate strongly from standard Fermi-liquid predictions and are reminiscent of the behaviour observed in its sibling system CePd 2Si 2 above the critical pressure at which magnetic order is suppressed. We have explored the CePd 2Si 2/CeNi 2Ge 2 phase diagram in a series of resistivity measurements under high hydrostatic pressure, p. At p > 15 kbar, a new superconducting transition appears below 220 mK in CeNi 2Ge 2 and shifts to higher temperatures with increasing pressure, reaching ≈400 mK at p ≈ 26 kbar.

  12. Investigation of electronic structure and chemical bonding of intermetallic Pd2HfIn: An ab-initio study

    NASA Astrophysics Data System (ADS)

    Bano, Amreen; Gaur, N. K.

    2018-05-01

    Ab-initio calculations are carried out to study the electronic and chemical bonding properties of Intermetallic full Heusler compound Pd2HfIn which crystallizes in F-43m structure. All calculations are performed by using density functional theory (DFT) based code Quantum Espresso. Generalized gradient approximations (GGA) of Perdew- Burke- Ernzerhof (PBE) have been adopted for exchange-correlation potential. Calculated electronic band structure reveals the metallic character of the compound. From partial density of states (PDoS), we found the presence of relatively high intensity electronic states of 4d-Pd atom at Fermi level. We have found a pseudo-gap just abouve the Fermi level and N(E) at Fermi level is observed to be 0.8 states/eV, these finding indicates the existence of superconducting character in Pd2HfIn.

  13. TRAC-PD2 posttest analysis of CCTF Test C1-16 (Run 025). [Cylindrical Core Test Facility

    SciTech Connect

    Sugimoto, J.

    The TRAC-PD2 code version was used to analyze CCTF Test C1-16 (Run 025). The results indicate that the core heater rod temperatures, the liquid mass in the vessel, and differential pressures in the primary loop are predicted well, but the void fraction distribution in the core and water accumulation in the upper plenum are not in good agreement with the data.

  14. Structure and bonding of [Pd2Sn18]4-: an interesting example of the mutual delocalisation phenomenon.

    PubMed

    Sheong, Fu Kit; Chen, Wen-Jie; Zhang, Jing-Xuan; Li, Yang; Lin, Zhenyang

    2017-02-14

    In this article, we have presented a computational analysis on the structure and bonding of [Pd 2 Sn 18 ] 4- and illustrated that it serves as an interesting example of OMO-UMO mutual delocalisation with two identical [PdE 9 ] 2- fragments. We have also illustrated the alternative roles that could be played by an [ME 9 ] 2- /[E 9 ] 2- fragment, a simple L-type donor and a lone-pair acceptor.

  15. Complex magnetic behaviour and evidence of a superspin glass state in the binary intermetallic compound Er5Pd2

    NASA Astrophysics Data System (ADS)

    Sharma, Mohit K.; Yadav, Kavita; Mukherjee, K.

    2018-05-01

    The binary intermetallic compound Er5Pd2 has been investigated using dc and ac magnetic susceptibilities, magnetic memory effect, isothermal magnetization, non-linear dc susceptibility, heat capacity and magnetocaloric effect studies. Interestingly, even though the compound does not show geometrical frustration it undergoes glassy magnetic phase transition below 17.2 K. Investigation of dc magnetization and heat capacity data divulged absence of long-ranged magnetic ordering. Through the magnetic memory effect, time dependent magnetization and ac susceptibility studies it was revealed that the compound undergoes glass-like freezing below 17.2 K. Analysis of frequency dependence of this transition temperature through scaling and Arrhenius law; along with the Mydosh parameter indicate, that the dynamics in Er5Pd2 are due to the presence of strongly interacting superspins rather than individual spins. This phase transition was further investigated by non-linear dc susceptibility and was characterized by static critical exponents γ and δ. Our results indicate that this compound shows the signature of superspin glass at low temperature. Additionally, both conventional and inverse magnetocaloric effect was observed with a large value of magnetic entropy change and relative cooling power. Our results suggest that Er5Pd2 can be classified as a superspin glass system with large magnetocaloric effect.

  16. Quantitative in vitro assessment of Mg65 Zn30 Ca5 degradation and its effect on cell viability.

    PubMed

    Cao, Jake D; Martens, Penny; Laws, Kevin J; Boughton, Philip; Ferry, Michael

    2013-01-01

    A bulk metallic glass (BMG) of composition Mg(65) Zn(30) Ca(5) was cast directly from the melt and explored as a potential bioresorbable metallic material. The in vitro degradation behavior of the amorphous alloy and its associated effects on cellular activities were assessed against pure crystalline magnesium. Biocorrosion tests using potentiodynamic polarization showed that the amorphous alloy corroded at a much slower rate than the crystalline Mg. Analysis of the exchanged media using inductively coupled plasma optical emission spectrometry revealed that the dissolution rate of Mg ions in the BMG was 446 μg/cm(2)/day, approximately half the rate of crystalline Mg (859 μg/cm(2)/day). A cytotoxicity study, using L929 murine fibroblasts, revealed that both the BMG and pure Mg are capable of supporting cellular activities. However, direct contact with the samples created regions of minimal cell growth around both amorphous and crystalline samples, and no cell attachment was observed. Copyright © 2012 Wiley Periodicals, Inc.

  17. Optimizing the Dopant and Carrier Concentration of Ca5Al2Sb6 for High Thermoelectric Efficiency

    PubMed Central

    Yan, Yuli; Zhang, Guangbiao; Wang, Chao; Peng, Chengxiao; Zhang, Peihong; Wang, Yuanxu; Ren, Wei

    2016-01-01

    The effects of doping on the transport properties of Ca5Al2Sb6 are investigated using first-principles electronic structure methods and Boltzmann transport theory. The calculated results show that a maximum ZT value of 1.45 is achieved with an optimum carrier concentration at 1000 K. However, experimental studies have shown that the maximum ZT value is no more than 1 at 1000 K. By comparing the calculated Seebeck coefficient with experimental values, we find that the low dopant solubility in this material is not conductive to achieve the optimum carrier concentration, leading a smaller experimental value of the maximum ZT. Interestingly, the calculated dopant formation energies suggest that optimum carrier concentrations can be achieved when the dopants and Sb atoms have similar electronic configurations. Therefore, it might be possible to achieve a maximum ZT value of 1.45 at 1000 K with suitable dopants. These results provide a valuable theoretical guidance for the synthesis of high-performance bulk thermoelectric materials through dopants optimization. PMID:27406178

  18. Draft Genome Sequence of Rhodobacteraceae Strain PD-2, an Algicidal Bacterium with a Quorum-Sensing System, Isolated from the Marine Microalga Prorocentrum donghaiense.

    PubMed

    Zheng, Li; Cui, Zhisong; Xu, Luyan; Sun, Chengjun; Powell, Ryan J; Hill, Russell T

    2015-02-19

    Rhodobacteraceae strain PD-2 was isolated from the marine microalga Prorocentrum donghaiense. It has algicidal activity toward its host and could produce N-acylhomoserine lactone signals. Here, we present the draft genome of strain PD-2, which contains 5,227,214 bp with an average GC content of 66.19%. There were 4,864 encoding gene sequences and two clusters of luxI and luxR homologues identified. Copyright © 2015 Zheng et al.

  19. Draft Genome Sequence of Rhodobacteraceae Strain PD-2, an Algicidal Bacterium with a Quorum-Sensing System, Isolated from the Marine Microalga Prorocentrum donghaiense

    PubMed Central

    Cui, Zhisong; Xu, Luyan; Sun, Chengjun; Powell, Ryan J.; Hill, Russell T.

    2015-01-01

    Rhodobacteraceae strain PD-2 was isolated from the marine microalga Prorocentrum donghaiense. It has algicidal activity toward its host and could produce N-acylhomoserine lactone signals. Here, we present the draft genome of strain PD-2, which contains 5,227,214 bp with an average GC content of 66.19%. There were 4,864 encoding gene sequences and two clusters of luxI and luxR homologues identified. PMID:25700405

  20. Development of electrochemical sensor for the determination of palladium ions (Pd2+) using flexible screen printed un-modified carbon electrode.

    PubMed

    Velmurugan, Murugan; Thirumalraj, Balamurugan; Chen, Shen-Ming; Al-Hemaid, Fahad M A; Ajmal Ali, M; Elshikh, Mohamed S

    2017-01-01

    To date, the development of different modified electrodes have received much attention in electrochemistry. The modified electrodes have some drawbacks such as high cost, difficult to handle and not eco friendly. Hence, we report an electrochemical sensor for the determination of palladium ions (Pd 2+ ) using an un-modified screen printed carbon electrode has been developed for the first time, which are characterized and studied via scanning electron microscope and cyclic voltammetry. Prior to determination of Pd 2+ ions, the operational conditions of un-modified SPCE was optimized using cyclic voltammetry and showed excellent electro-analytical behavior towards the determination of Pd 2+ ions. Electrochemical determination of Pd 2+ ions reveal that the un-modified electrode showed lower detection limit of 1.32μM with a linear ranging from 3 to 133.35μM towards the Pd 2+ ions concentration via differential pulse voltammetry. The developed sensor also applied to the successfully determination of trace level Pd 2+ ions in spiked water samples. In addition, the advantage of this type of electrode is simple, disposable and cost effective in electrochemical sensors. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Wet chemical synthesis and luminescence in Ca5(PO4)3M:Eu2+ (M = Br, I) phosphors for solid state lighting

    NASA Astrophysics Data System (ADS)

    Mungmode, C. D.; Gahane, D. H.; Moharil, S. V.

    2018-05-01

    A simple wet chemical synthesis of Eu2+ activated Ca5(PO4)3Br and Ca5(PO4)3I phosphors and their photoluminescence is reported. Formation of Ca5(PO4)3Br is confirmed by X-ray diffraction (XRD). Synthesized phosphors are analyzed for photoluminescence (PL) spectrum. A bright blue emission is observed when phosphors are excited by near Ultra Violet (nUV) radiations. Photoluminescence emission spectrum for (Ca0.985Eu0.015)5(PO4)3Br is centered at 457 nm and for (Ca0.985Eu0.015)5(PO4)3 I it peaks at 455 nm when excited by 365 nm near UV radiation. Eu2+ luminescence in Ca5(PO4)3Br is reported for the first time. The phosphors can be efficiently excited by nUV radiations. This shows that phosphors may be used as blue phosphor in pcLED for Solid State Lighting.

  2. Genomic organization of the human gene (CA5) and pseudogene for mitochondrial carbonic anhydrase V and their localization to chromosomes 16q and 16p

    SciTech Connect

    Nagao, Yoshiro; Sly, W.S.; Batanian, J.R.

    1995-08-10

    Carbonic anhydrase V (CA V) is expressed in mitochondrial matrix in liver and several other tissues. It is of interest for its putative roles in providing bicarbonate to carbamoyl phosphate synthetase for ureagenesis and to pyruvate carboxylase for gluconeogenesis and its possible importance in explaining certain inherited metabolic disorders with hyperammonemia and hypoglycemia. Following the recent characterization of the cDNA for human CA V, we report the isolation of the human gene from two {lambda} genomic libraries and its characterization. The CA V gene (CA5) is approximately 50 kb long and contains 7 exons and 6 introns. The exon-intron boundariesmore » are found in positions identical to those determined for the previously described CA II, CA III, and CA VII genes. Like the CA VII gene, CA5 does not contain typical TATA and CAAT promoter elements in the 5{prime} flanking region but does contain a TTTAA sequence 147 nucleotides upstream of the initiation codon. CA5 also contains a 12-bp GT-rich segment beginning 13 bp downstream of the polyadenylation signal in the 3{prime} untranslated region of exon 7. FISH analysis allowed CA5 to be assigned to chromosome 16q24.3. An unprocessed pseudogene containing sequence homologous to exons 3-7 and introns 3-6 was also isolated and was assigned by FISH analysis to chromosome 16p11.2-p12. 22 refs., 4 figs., 1 tab.« less

  3. Converting MMSE to MoCA and MoCA 5-minute protocol in an educationally heterogeneous sample with stroke or transient ischemic attack.

    PubMed

    Wong, Adrian; Black, Sandra E; Yiu, Stanley Y P; Au, Lisa W C; Lau, Alexander Y L; Soo, Yannie O Y; Chan, Anne Y Y; Leung, Thomas W H; Wong, Lawrence K S; Kwok, Timothy C Y; Cheung, Theodore C K; Leung, Kam-Tat; Lam, Bonnie Y K; Kwan, Joseph S K; Mok, Vincent C T

    2018-05-01

    The Montreal Cognitive Assessment (MoCA) is psychometrically superior over the Mini-mental State Examination (MMSE) for cognitive screening in stroke or transient ischemic attack (TIA). It is free for clinical and research use. The objective of this study is to convert scores from the MMSE to MoCA and MoCA-5-minute protocol (MoCA-5 min) and to examine the ability of the converted scores in detecting cognitive impairment after stroke or TIA. A total of 904 patients were randomly divided into training (n = 623) and validation (n = 281) samples matched for demography and cognition. MMSE scores were converted to MoCA and MoCA-5 min using (1) equipercentile method with log-linear smoothing and (2) Poisson regression adjusting for age and education. Receiver operating characteristics curve analysis was used to examine the ability of the converted scores in differentiating patients with cognitive impairment. The mean education was 5.8 (SD = 4.6; ranged 0-20) years. The entire spectrum of MMSE scores was converted to MoCA and MoCA-5 min using equipercentile method. Relationship between MMSE and MoCA scores was confounded by age and education, and a conversion equation with adjustment for age and education was derived. In the validation sample, the converted scores differentiated cognitively impaired patients with area under receiver operating characteristics curve 0.826 to 0.859. We provided 2 methods to convert scores from the MMSE to MoCA and MoCA-5 min based on a large sample of patients with stroke or TIA having a wide range of education and cognitive levels. The converted scores differentiated patients with cognitive impairment after stroke or TIA with high accuracy. Copyright © 2018 John Wiley & Sons, Ltd.

  4. Equilibrium, kinetics and mechanism of Au3+, Pd2+ and Ag+ ions adsorption from aqueous solutions by graphene oxide functionalized persimmon tannin.

    PubMed

    Wang, Zhongmin; Li, Xiaojuan; Liang, Haijun; Ning, Jingliang; Zhou, Zhide; Li, Guiyin

    2017-10-01

    In this study, a novel bio-adsorbent (PT-GO) was prepared by functionalization persimmon tannin (PT) with graphene oxide (GO) and the effective adsorption behaviors of Au 3+ , Pd 2+ and Ag + ions from aqueous solution was investigated. The PT-GO was characterized by Fourier transform infrared spectrometer (FTIR), scanning electronic microscope (SEM), thermogravimetric analysis (TGA) and Zeta potential. Many influence factors such as pH value, bio-adsorbent dosage, initial concentration of metal ions and contact time were optimized. The maximum adsorption capacity for Au 3+ , Pd 2+ and Ag + was 1325.09mg/g, 797.66mg/g and 421.01mg/g, respectively. The equilibrium isotherm for the adsorption of Au 3+ and Ag + on PT-GO were found to obey the Langmuir model, while the Freundlich model fitted better for Pd 2+ . The adsorption process of Au 3+ , Pd 2+ presented relatively fast adsorption kinetics with pseudo-second-order equation as the best fitting model, while the pseudo-first-order kinetic model was suitable for describing the adsorption of Ag + . Combination of ion exchange, electrostatic interaction and physical adsorption was the mechanism for adsorption of Au 3+ , Pd 2+ and Ag + onto PT-GO bio-adsorbent. Therefore, the PT-GO bio-adsorbent would be an ideal adsorbent for removal of precious metal ions and broaden the potential applications of persimmon tannin in environmental research. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. 27Al-NMR studies of the structural phase transition in LaPd2Al2

    NASA Astrophysics Data System (ADS)

    Aoyama, Taisuke; Kobayashi, Fumiaki; Kotegawa, Hisashi; Tou, Hideki; Doležal, Petr; Kriegner, Dominik; Javorský, Pavel; Uhlířová, Klára

    2018-05-01

    We performed 27Al-NMR measurements for the CaBe2Ge2 type single crystalline LaPd2Al2 in the temperature range from 100 K to 5 K to investigate the origin of the structural phase transition. We found that the line profile of the 27Al-NMR spectrum does not change entirely on passing through the structural phase transition at Tst. Meanwhile, the peak position of the central line slightly change (≈ 30 ppm) below 70 K, suggesting the orbital shift changes below Tst. The present 27Al-NMR studies evidence that the local electronic state at Al site is hardly affected by the structural phase transition.

  6. High-resolution EPMA X-ray images of mother liquid inclusions in a Pd2Ga single crystal

    NASA Astrophysics Data System (ADS)

    Müller, D.; Schwerin, J.; Gille, P.; Fehr, K. T.

    2014-03-01

    During crystal growth from solution inclusions of different compositions were trapped at the rim of a Pd2Ga single crystal. Their fine-grained (< 5 μm) internal structure demands special requirements for electron microprobe analysis, realized by low-voltage (5 keV) element mapping applying a step size of 0.138 μm for each pixel. It can be shown, that these inclusions represent an isolated chemical system, and that crystallisation upon cooling follows the expected thermodynamic phase relations. Thus the final composition in the centre of the inclusion consists of a small-scale mixture of PdGa and Pd5Ga3 evolved out of a solid-solid decomposition of Pd5Ga4.

  7. Enhanced UVB emission and analysis of chemical states of Ca5(PO4)3OH:Gd3+,Pr3+ phosphor prepared by co-precipitation

    NASA Astrophysics Data System (ADS)

    Mokoena, P. P.; Nagpure, I. M.; Kumar, Vinay; Kroon, R. E.; Olivier, E. J.; Neethling, J. H.; Swart, H. C.; Ntwaeaborwa, O. M.

    2014-08-01

    Hydroxyapatite (Ca5(PO4)3OH) is a well-known bioceramic material used in medical applications because of its ability to form direct chemical bonds with living tissues. This mineral is currently used as a host for rare-earth ions (e.g. Gd3+, Pr3+, Tb3+, etc.) to prepare phosphors that can be used in light emitting devices of different types. In this study Ca5(PO4)3OH:Gd3+,Pr3+ phosphors were prepared by the co-precipitation method and were characterised by x-ray diffraction, x-ray photoelectron spectroscopy, scanning electron microscopy, high resolution transmission electron microscopy, energy dispersive x-ray spectroscopy and photoluminescence spectroscopy. The x-ray diffraction pattern was consistent with the hexagonal phase of Ca5(PO4)3OH referenced in JCPDS card number 73-0293. The x-ray photoelectron spectroscopy data indicated that Ca2+ occupied two different lattice sites, referred to as Ca1 and Ca2. The photoluminescence data exhibited a narrowband emission located at 313 nm, which is associated with the 6P7/2→8S7/2 transition of the Gd3+ ion. This emission is classified as ultraviolet B and it is suitable for use in phototherapy lamps to treat various skin diseases. The photoluminescence intensity of the 313 nm emission was enhanced considerably by Pr3+ co-doping.

  8. Synthesis of Supported Pd 0 Nanoparticles from a Single-Site Pd 2+ Surface Complex by Alkene Reduction

    DOE PAGES

    Mouat, Aidan R.; Whitford, Cassandra L.; Chen, Bor-Rong; ...

    2018-02-02

    Here, a surface metal–organic complex, (-AlO x)Pd(acac) (acac = acetylacetonate), is prepared by chemically grafting the precursor Pd(acac) 2 onto γ-Al 2O 3 in toluene at 25 °C. The resulting surface complex is characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and dynamic nuclear polarization surface-enhanced solid-state nuclear magnetic resonance spectroscopy (DNP SENS). This surface complex is a precursor in the direct synthesis of size-controlled Pd nanoparticles under mild reductive conditions and in the absence of additional stabilizers or pretreatments. Indeed, upon exposure to gaseous ethylene or liquid 1-octene at 25more » °C, the Pd 2+ species is reduced to form Pd 0 nanoparticles with a mean diameter of 4.3 ± 0.6 nm, as determined by scanning transmission electron microscopy (STEM). These nanoparticles are catalytically relevant using the aerobic 1-phenylethanol oxidation as a probe reaction, with rates comparable to a conventional Pd/Al 2O 3 catalyst but without an induction period. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature-programmed reaction mass spectrometry (TPR-MS) reveal that the surface complex reduction with ethylene coproduces H 2, acetylene, and 1,3-butadiene. This process reasonably proceeds via an olefin activation/coordination/insertion pathway, followed by β-hydride elimination to generate free Pd 0. Lastly, the well-defined nature of the single-site supported Pd 2+ precursor provides direct mechanistic insights into this unusual and likely general reductive process.« less

  9. Synthesis of Supported Pd 0 Nanoparticles from a Single-Site Pd 2+ Surface Complex by Alkene Reduction

    SciTech Connect

    Mouat, Aidan R.; Whitford, Cassandra L.; Chen, Bor-Rong

    Here, a surface metal–organic complex, (-AlO x)Pd(acac) (acac = acetylacetonate), is prepared by chemically grafting the precursor Pd(acac) 2 onto γ-Al 2O 3 in toluene at 25 °C. The resulting surface complex is characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and dynamic nuclear polarization surface-enhanced solid-state nuclear magnetic resonance spectroscopy (DNP SENS). This surface complex is a precursor in the direct synthesis of size-controlled Pd nanoparticles under mild reductive conditions and in the absence of additional stabilizers or pretreatments. Indeed, upon exposure to gaseous ethylene or liquid 1-octene at 25more » °C, the Pd 2+ species is reduced to form Pd 0 nanoparticles with a mean diameter of 4.3 ± 0.6 nm, as determined by scanning transmission electron microscopy (STEM). These nanoparticles are catalytically relevant using the aerobic 1-phenylethanol oxidation as a probe reaction, with rates comparable to a conventional Pd/Al 2O 3 catalyst but without an induction period. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature-programmed reaction mass spectrometry (TPR-MS) reveal that the surface complex reduction with ethylene coproduces H 2, acetylene, and 1,3-butadiene. This process reasonably proceeds via an olefin activation/coordination/insertion pathway, followed by β-hydride elimination to generate free Pd 0. Lastly, the well-defined nature of the single-site supported Pd 2+ precursor provides direct mechanistic insights into this unusual and likely general reductive process.« less

  10. Risk stratification for arrhythmic death in an emergency department cohort: a new method of nonlinear PD2i analysis of the ECG

    PubMed Central

    Skinner, James E; Meyer, Michael; Dalsey, William C; Nester, Brian A; Ramalanjaona, George; O’Neil, Brian J; Mangione, Antoinette; Terregino, Carol; Moreyra, Abel; Weiss, Daniel N; Anchin, Jerry M; Geary, Una; Taggart, Pamela

    2008-01-01

    Heart rate variability (HRV) reflects both cardiac autonomic function and risk of sudden arrhythmic death (AD). Indices of HRV based on linear stochastic models are independent risk factors for AD in postmyocardial infarction (MI) cohorts. Indices based on nonlinear deterministic models have a higher sensitivity and specificity for predicting AD in retrospective data. A new nonlinear deterministic model, the automated Point Correlation Dimension (PD2i), was prospectively evaluated for prediction of AD. Patients were enrolled (N = 918) in 6 emergency departments (EDs) upon presentation with chest pain and being determined to be at risk of acute MI (AMI) >7%. Brief digital ECGs (>1000 heartbeats, ∼15 min) were recorded and automated PD2i results obtained. Out-of-hospital AD was determined by modified Hinkle-Thaler criteria. All-cause mortality at 1 year was 6.2%, with 3.5% being ADs. Of the AD fatalities, 34% were without previous history of MI or diagnosis of AMI. The PD2i prediction of AD had sensitivity = 96%, specificity = 85%, negative predictive value = 99%, and relative risk >24.2 (p ≤ 0.001). HRV analysis by the time-dependent nonlinear PD2i algorithm can accurately predict risk of AD in an ED cohort and may have both life-saving and resource-saving implications for individual risk assessment. PMID:19209249

  11. Nonlinear analysis of the heartbeats in public patient ECGs using an automated PD2i algorithm for risk stratification of arrhythmic death

    PubMed Central

    Skinner, James E; Anchin, Jerry M; Weiss, Daniel N

    2008-01-01

    Heart rate variability (HRV) reflects both cardiac autonomic function and risk of arrhythmic death (AD). Reduced indices of HRV based on linear stochastic models are independent risk factors for AD in post-myocardial infarct cohorts. Indices based on nonlinear deterministic models have a significantly higher sensitivity and specificity for predicting AD in retrospective data. A need exists for nonlinear analytic software easily used by a medical technician. In the current study, an automated nonlinear algorithm, the time-dependent point correlation dimension (PD2i), was evaluated. The electrocardiogram (ECG) data were provided through an National Institutes of Health-sponsored internet archive (PhysioBank) and consisted of all 22 malignant arrhythmia ECG files (VF/VT) and 22 randomly selected arrhythmia files as the controls. The results were blindly calculated by automated software (Vicor 2.0, Vicor Technologies, Inc., Boca Raton, FL) and showed all analyzable VF/VT files had PD2i < 1.4 and all analyzable controls had PD2i > 1.4. Five VF/VT and six controls were excluded because surrogate testing showed the RR-intervals to contain noise, possibly resulting from the low digitization rate of the ECGs. The sensitivity was 100%, specificity 85%, relative risk > 100; p < 0.01, power > 90%. Thus, automated heartbeat analysis by the time-dependent nonlinear PD2i-algorithm can accurately stratify risk of AD in public data made available for competitive testing of algorithms. PMID:18728829

  12. In vitro metal ion release and biocompatibility of amorphous Mg67Zn28Ca5 alloy with/without gelatin coating.

    PubMed

    Chan, W Y; Chian, K S; Tan, M J

    2013-12-01

    Amorphous zinc-rich Mg-Zn-Ca alloys have exhibited good tissue compatibility and low hydrogen evolution in vivo. However, suboptimal cell-surface interaction on magnesium alloy surface observed in vitro could lead to reduced integration with host tissue for regenerative purpose. This study aims to improve cell-surface interaction of amorphous Mg67Zn28Ca5 alloy by coating a gelatin layer by electrospinning. Coated/uncoated alloys were immersed and extracted for 3 days under different CO2. The immersion results showed that pH and metal ion release in the alloy extracts were affected by gelatin coating and CO2, suggesting their roles in alloy biocorrosion and a mechanism has been proposed for the alloy-CO2 system with/without coating. Cytotoxicity results are evident that gelatin-coated alloy with 2-day crosslinking not only exhibited no indirect cytotoxicity, but also supported attachment of L929 and MG63 cell lines around/on the alloy with high viability. Therefore, amorphous Mg67Zn28Ca5 alloy coated with gelatin by electrospinning technique provides a useful method to improve alloy biocompatibility. © 2013 Elsevier B.V. All rights reserved.

  13. Solid-State Gas Adsorption Studies with Discrete Palladium(II) [Pd2 (L)4 ]4+ Cages.

    PubMed

    Preston, Dan; White, Keith F; Lewis, James E M; Vasdev, Roan A S; Abrahams, Brendan F; Crowley, James D

    2017-08-04

    The need for effective CO 2 capture systems remains high, and due to their tunability, metallosupramolecular architectures are an attractive option for gas sorption. While the use of extended metal organic frameworks for gas adsorption has been extensively explored, the exploitation of discrete metallocage architectures to bind gases remains in its infancy. Herein the solid state gas adsorption properties of a series of [Pd 2 (L) 4 ] 4+ lantern shaped coordination cages (L = variants of 2,6-bis(pyridin-3-ylethynyl)pyridine), which had solvent accessible internal cavities suitable for gas binding, have been investigated. The cages showed little interaction with dinitrogen gas but were able to take up CO 2 . The best performing cage reversibly sorbed 1.4 mol CO 2 per mol cage at 298 K, and 2.3 mol CO 2 per mol cage at 258 K (1 bar). The enthalpy of binding was calculated to be 25-35 kJ mol -1 , across the number of equivalents bound, while DFT calculations on the CO 2 binding in the cage gave ΔE for the cage-CO 2 interaction of 23-28 kJ mol -1 , across the same range. DFT modelling suggested that the binding mode is a hydrogen bond between the carbonyl oxygen of CO 2 and the internally directed hydrogen atoms of the cage. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Enhanced NIR downconversion luminescence by precipitating nano Ca5(PO4)3F crystals in Eu2+-Yb3+ co-doped glass

    NASA Astrophysics Data System (ADS)

    Li, Chen; Song, Zhiguo; Li, Yongjin; Lou, Kai; Qiu, Jianbei; Yang, Zhengwen; Yin, Zhaoyi; Wang, Xue; Wang, Qi; Wan, Ronghua

    2013-10-01

    Eu2+-Yb3+ co-doped transparent glass-ceramic containing nano-Ca5(PO4)3F (FAP) was prepared in reducing atmosphere. XRD and TEM analysis indicated that nano-FAP about 40 nm precipitated homogeneously in glass matrix after heat treatment. Confirmed by spectroscopy measurements, the crystal-like absorption and emission of Eu2+ indicated the partition of Eu2+ into FAP nanocrystals in glass ceramic. NIR emission due to the transition 2F→2F of Yb3+ ions (about 980-1100 nm) was observed from glasses under ultraviolet excitation, ascribed to downconversion from Eu2+ to Yb3+, which can be enhanced by precipitating nano-FAP crystals. The results indicated that Eu2+-Yb3+ co-doped glass-ceramic embedding with nano-FAP is a promising candidate as downconversion materials for enhancing conversion efficiency of solar cells.

  15. High-pressure effects on isotropic superconductivity in the iron-free layered pnictide superconductor BaPd2As2

    NASA Astrophysics Data System (ADS)

    Abdel-Hafiez, M.; Zhao, Y.; Huang, Z.; Cho, C.-w.; Wong, C. H.; Hassen, A.; Ohkuma, M.; Fang, Y.-W.; Pan, B.-J.; Ren, Z.-A.; Sadakov, A.; Usoltsev, A.; Pudalov, V.; Mito, M.; Lortz, R.; Krellner, C.; Yang, W.

    2018-04-01

    While the layered 122 iron arsenide superconductors are highly anisotropic, unconventional, and exhibit several forms of electronic orders that coexist or compete with superconductivity in different regions of their phase diagrams, we find in the absence of iron in the structure that the superconducting characteristics of the end member BaPd2As2 are surprisingly conventional. Here we report on complementary measurements of specific heat, magnetic susceptibility, resistivity measurements, Andreev spectroscopy, and synchrotron high pressure x-ray diffraction measurements supplemented with theoretical calculations for BaPd2As2 . Its superconducting properties are completely isotropic as demonstrated by the critical fields, which do not depend on the direction of the applied field. Under the application of high pressure, Tc is linearly suppressed, which is the typical behavior of classical phonon-mediated superconductors with some additional effect of a pressure-induced decrease in the electronic density of states and the electron-phonon coupling parameters. Structural changes in the layered BaPd2As2 have been studied by means of angle-dispersive diffraction in a diamond-anvil cell. At 12 GPa and 24.2 GPa we observed pressure induced lattice distortions manifesting as the discontinuity and, hence discontinuity in the Birch-Murnaghan equation of state. The bulk modulus is B0=40 (6 ) GPa below 12 GPa and B0=142 (3 ) GPa below 27.2 GPa.

  16. Valence State Driven Site Preference in the Quaternary Compound Ca5MgAgGe5: An Electron-Deficient Phase with Optimized Bonding

    SciTech Connect

    Ponou, Simeon; Lidin, Sven; Zhang, Yuemei

    The quaternary phase Ca5Mg0.95Ag1.05(1)Ge5 (3) was synthesized by high-temperature solid-state techniques, and its crystal structure was determined by single-crystal diffraction methods in the orthorhombic space group Pnma – Wyckoff sequence c12 with a = 23.1481(4) Å, b = 4.4736(1) Å, c = 11.0128(2) Å, V = 1140.43(4) Å3, Z = 4. The crystal structure can be described as linear intergrowths of slabs cut from the CaGe (CrB-type) and the CaMGe (TiNiSi-type; M = Mg, Ag) structures. Hence, 3 is a hettotype of the hitherto missing n = 3 member of the structure series with the general formula R2+nT2X2+n, previously describedmore » with n = 1, 2, and 4. The member with n = 3 was predicted in the space group Cmcm – Wyckoff sequence f5c2. The experimental space group Pnma (in the nonstandard setting Pmcn) corresponds to a klassengleiche symmetry reduction of index two of the predicted space group Cmcm. This transition originates from the switching of one Ge and one Ag position in the TiNiSi-related slab, a process that triggers an uncoupling of each of the five 8f sites in Cmcm into two 4c sites in Pnma. The Mg/Ag site preference was investigated using VASP calculations and revealed a remarkable example of an intermetallic compound for which the electrostatic valency principle is a critical structure-directing force. The compound is deficient by one valence electron according to the Zintl concept, but LMTO electronic structure calculations indicate electronic stabilization and overall bonding optimization in the polyanionic network. Other stability factors beyond the Zintl concept that may account for the electronic stabilization are discussed.« less

  17. Multilayered cuprate superconductor Ba2Ca5Cu6O12(O1-x,Fx) 2 studied by temperature-dependent scanning tunneling microscopy and spectroscopy

    NASA Astrophysics Data System (ADS)

    Sugimoto, Akira; Ekino, Toshikazu; Gabovich, Alexander M.; Sekine, Ryotaro; Tanabe, Kenji; Tokiwa, Kazuyasu

    2017-05-01

    Scanning tunneling microscopy/spectroscopy (STM/STS) measurements were carried out on a multilayered cuprate superconductor Ba2Ca5Cu6O12 (O1 -x,Fx )2. STM topography revealed random spot structures with the characteristic length ≤0.5 nm. The conductance spectra d I /d V (V ) show the coexistence of smaller gaps ΔS and large gaps (pseudogaps) ΔL. The pseudogap-related features in the superconducting state were traced with the spatial resolution of ˜0.07 nm. Here, I and V are the tunnel current and bias voltage, respectively. The temperature, T , dependence of ΔS follows the reduced Bardeen-Cooper-Schrieffer (BCS) dependence. The hallmark ratio 2 ΔS(T =0 ) /kBTc equals to 4.9, which is smaller than those of other cuprate superconductors. Here, Tc is the superconducting critical temperature and kB is the Boltzmann constant. The larger gap ΔL survives in the normal state and even increases with T above Tc. The T dependencies of the spatial distributions for both relevant gaps (Δ map), as well as for each gap separately (ΔS and ΔL), were obtained. From the histogram of Δ map, the averaged gap values were found to be Δ¯S=˜24 meV and Δ¯L=˜79 meV. The smaller gap ΔS shows a spatially homogeneous distribution while the larger gap ΔL is quite inhomogeneous, indicating that rather homogeneous superconductivity coexists with the patchy distributed pseudogap. The spatial variation length ξΔ L of ΔL correlates with the scale of the topography spot structures, being approximately 0.4 nm. This value is considerably smaller than the coherence length of this class of superconductors, suggesting that ΔL is strongly affected by the disorder of the apical O/F.

  18. Volovik effect and Fermi-liquid behavior in the s -wave superconductor CaPd 2 As 2 :   As 75 NMR-NQR measurements

    DOE PAGES

    Ding, Q. -P.; Wiecki, P.; Anand, V. K.; ...

    2016-04-07

    The electronic and magnetic properties of the collapsed-tetragonal CaPd 2As 2 superconductor (SC) with a transition temperature of 1.27 K have been investigated by 75As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements. The temperature (T) dependence of the nuclear spin lattice relaxation rates (1/T 1) and the Knight shifts indicate the absence of magnetic correlations in the normal state. In the SC state, 1/T 1 measured by 75As NQR shows a clear Hebel-Slichter (HS) peak just below T c and decreases exponentially at lower T, confirming a conventional s-wave SC. Additionally, the Volovik effect, also known asmore » the Doppler shift effect, has been clearly evidenced by the observation of the suppression of the HS peak with applied magnetic field.« less

  19. Volovik effect and Fermi-liquid behavior in the s -wave superconductor CaPd 2 As 2 :   As 75 NMR-NQR measurements

    SciTech Connect

    Ding, Q. -P.; Wiecki, P.; Anand, V. K.

    The electronic and magnetic properties of the collapsed-tetragonal CaPd 2As 2 superconductor (SC) with a transition temperature of 1.27 K have been investigated by 75As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements. The temperature (T) dependence of the nuclear spin lattice relaxation rates (1/T 1) and the Knight shifts indicate the absence of magnetic correlations in the normal state. In the SC state, 1/T 1 measured by 75As NQR shows a clear Hebel-Slichter (HS) peak just below T c and decreases exponentially at lower T, confirming a conventional s-wave SC. Additionally, the Volovik effect, also known asmore » the Doppler shift effect, has been clearly evidenced by the observation of the suppression of the HS peak with applied magnetic field.« less

  20. An azodye-rhodamine-based fluorescent and colorimetric probe specific for the detection of Pd(2+) in aqueous ethanolic solution: synthesis, XRD characterization, computational studies and imaging in live cells.

    PubMed

    Mahapatra, Ajit Kumar; Manna, Saikat Kumar; Maiti, Kalipada; Mondal, Sanchita; Maji, Rajkishor; Mandal, Debasish; Mandal, Sukhendu; Uddin, Md Raihan; Goswami, Shyamaprosad; Quah, Ching Kheng; Fun, Hoong-Kun

    2015-02-21

    Azodye-rhodamine hybrid colorimetric fluorescent probe (L) has been designed and synthesized. The structure of L has been established based on single crystal XRD. It has been shown to act as a selective turn-on fluorescent chemosensor for Pd(2+) with >40 fold enhancement by exhibiting red emission among the other 27 cations studied in aqueous ethanol. The coordination features of the species of recognition have been computationally evaluated by DFT methods and found to have a distorted tetrahedral Pd(2+) center in the binding core. The probe (L) has been shown to detect Pd up to 0.45 μM at pH 7.4. Furthermore, the probe can be used to image Pd(2+) in living cells.

  1. Properties and Crystallization Phenomena in Li2Si2O5-Ca5(PO4)3F and Li2Si2O5-Sr5(PO4)3F Glass-Ceramics Via Twofold Internal Crystallization.

    PubMed

    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.

  2. A Comparative Study of Structural Stability and Mechanical and Optical Properties of Fluorapatite (Ca5(PO4)3F) and Lithium Disilicate (Li2Si2O5) Components Forming Dental Glass-Ceramics: First Principles Study

    NASA Astrophysics Data System (ADS)

    Biskri, Z. E.; Rached, H.; Bouchear, M.; Rached, D.; Aida, M. S.

    2016-10-01

    The aim of this paper is a comparative study of structural stability and mechanical and optical properties of fluorapatite (FA) (Ca5(PO4)3F) and lithium disilicate (LD) (Li2Si2O5), using the first principles pseudopotential method based on density functional theory (DFT) within the generalized gradient approximation (GGA). The stability of fluorapatite and lithium disilicate compounds has been evaluated on the basis of their formation enthalpies. The results show that fluorapatite is more energetically stable than lithium disilicate. The independent elastic constants and related mechanical properties, including bulk modulus ( B), shear modulus ( G), Young's modulus ( E) and Poisson's ratio ( ν) as well as the Vickers hardness ( H v), have been calculated for fluorapatite compound and compared with other theoretical and experimental results. The obtained values of the shear modulus, Young's modulus and Vickers hardness are smaller in comparison with those of lithium disilicate compound, implying that lithium disilicate is more rigid than fluorapatite. The brittle and ductile properties were also discussed using B/ G ratio and Poisson's ratio. Optical properties such as refractive index n( ω), extinction coefficient k( ω), absorption coefficient α( ω) and optical reflectivity R( ω) have been determined from the calculations of the complex dielectric function ɛ( ω), and interpreted on the basis of the electronic structures of both compounds. The calculated values of static dielectric constant ɛ 1(0) and static refractive index n(0) show that the Li2Si2O5 compound has larger values compared to those of the Ca5(PO4)3F compound. The results of the extinction coefficient show that Li2Si2O5 compound exhibits a much stronger ultraviolet absorption. According to the absorption and reflectivity spectra, we inferred that both compounds are theoretically the best visible and infrared transparent materials.

  3. Novel rare-earth-free yellow Ca5Zn3.92In0.08(V0.99Ta0.01O4)6 phosphors for dazzling white light-emitting diodes.

    PubMed

    Pavitra, E; Raju, G Seeta Rama; Park, Jin Young; Wang, Lili; Moon, Byung Kee; Yu, Jae Su

    2015-05-20

    White light-emitting diode (WLED) products currently available on the market are based on the blue LED combined with yellow phosphor approach. However, these WLEDs are still insufficient for general illumination and flat panel display (FPD) applications because of their low color-rendering index (CRI < 75) and high correlated color temperature (CCT = 6000 K). Although near-ultraviolet (UV) LED chips provide more efficient excitation than blue chips, YAG:Ce(3+) phosphors have very weak excitation in the near-UV spectral region. Hence, there is an increasing demand for novel yellow phosphor materials with excitation in the near-UV region. In this work, we report novel self-activated yellow Ca(5)Zn(3.92)In(0.08)(V(0.99)Ta(0.01)O(4))(6) (CZIVT) phosphors that efficiently convert near-UV excitation light into yellow luminescence. The crystal structure and lattice parameters of these CZIVT phosphors are elucidated through Rietveld refinement. Through doping with In(3+) and Ta(5+) ions, the emission intensity is enhanced in the red region, and the Stokes shift is controlled to obtain good color rendition. When a near-UV LED chip is coated with a combination of CZIVT and commercial blue Ba(0.9)Eu(0.1)MgAl(10)O(17) phosphors, a pleasant WLED with a high CRI of 82.51 and a low CCT of 5231 K, which are essential for indoor illumination and FPDs, is achieved.

  4. Fluorcanasite, K3Na3Ca5Si12O30(F,OH)4 · H2O, a new mineral species from the Khibiny alkaline pluton, Kola Peninsula, Russia, and new data on canasite

    NASA Astrophysics Data System (ADS)

    Khomyakov, A. P.; Nechelyustov, G. N.; Krivokoneva, G. K.; Rastsvetaeva, R. K.; Rozenberg, K. A.; Rozhdestvenskaya, I. V.

    2009-12-01

    .21)Σ4 · 0.98H2O. The idealized formula is K3Na3Ca5Si12O30(F,OH)4 · H2O, F > OH or K3Na3Ca5(Si12O30)F4 · H2O. The IR spectrum of the mineral, description of its crystal structure, and comparison with its close analogues, canasite and frankamenite, are given in the paper. New optical parameters and crystal data are presented for the type specimen of canasite from the Materialnaya adit, Mt. Yukspor, Khibiny. Type material is deposited at the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow.

  5. Novel rare-earth-free yellow Ca5Zn3.92In0.08(V0.99Ta0.01O4)6 phosphors for dazzling white light-emitting diodes

    PubMed Central

    Pavitra, E.; Raju, G. Seeta Rama; Park, Jin Young; Wang, Lili; Moon, Byung Kee; Yu, Jae Su

    2015-01-01

    White light-emitting diode (WLED) products currently available on the market are based on the blue LED combined with yellow phosphor approach. However, these WLEDs are still insufficient for general illumination and flat panel display (FPD) applications because of their low color-rendering index (CRI < 75) and high correlated color temperature (CCT = 6000 K). Although near-ultraviolet (UV) LED chips provide more efficient excitation than blue chips, YAG:Ce3+ phosphors have very weak excitation in the near-UV spectral region. Hence, there is an increasing demand for novel yellow phosphor materials with excitation in the near-UV region. In this work, we report novel self-activated yellow Ca5Zn3.92In0.08(V0.99Ta0.01O4)6 (CZIVT) phosphors that efficiently convert near-UV excitation light into yellow luminescence. The crystal structure and lattice parameters of these CZIVT phosphors are elucidated through Rietveld refinement. Through doping with In3+ and Ta5+ ions, the emission intensity is enhanced in the red region, and the Stokes shift is controlled to obtain good color rendition. When a near-UV LED chip is coated with a combination of CZIVT and commercial blue Ba0.9Eu0.1MgAl10O17 phosphors, a pleasant WLED with a high CRI of 82.51 and a low CCT of 5231 K, which are essential for indoor illumination and FPDs, is achieved. PMID:25993044

  6. Chlorellestadite, Ca5(SiO4)1.5(SO4)1.5Cl, a new ellestadite- group mineral from the Shadil-Khokh volcano, South Ossetia

    NASA Astrophysics Data System (ADS)

    Środek, Dorota; Galuskina, Irina O.; Galuskin, Evgeny; Dulski, Mateusz; Książek, Maria; Kusz, Joachim; Gazeev, Viktor

    2018-05-01

    Chlorellestadite (IMA2017-013), ideally Ca5(SiO4)1.5(SO4)1.5Cl, the Cl-end member of the ellestadite group was discovered in a calcium-silicate xenolith in rhyodacite lava from the Shadil Khokh volcano, Greater Caucasus, South Ossetia. Chlorellestadite forms white, tinged with blue or green, elongate crystals up to 0.2-0.3 mm in length. Associated minerals include spurrite, larnite, chlormayenite, rondorfite, srebrodolskite, jasmundite and oldhamite. The empirical crystal chemical formula of the holotype specimen is Ca4.99Na0.01(SiO4)1.51(SO4)1.46(PO4)0.03(Cl0.61OH0.21F0.11)Σ0.93. Unit-cell parameters of chlorellestadite are: P63/m, a = 9.6002(2), c = 6.8692(2) Å, V = 548.27(3)Å3, Z = 2. Chlorellestadite has a Mohs hardness of 4-4.5 and a calculated density of 3.091 g/cm3. The cleavage is indistinct, and the mineral shows irregular fracture. The Raman spectrum of chlorellestadite is similar to the spectra of other ellestadite group minerals, with main bands located at 267 cm-1 (Ca-O vibrations), and between 471 and 630 cm-1 (SiO4 4- and SO4 2- bending vibrations) and 850-1150 cm-1 (SiO4 4- and SO4 2- stretching modes). Chlorellestadite forms in xenoliths of calcium-silicate composition when they are exposed to Cl-bearing volcanic exhalations at about 1000 °C under low pressure conditions.

  7. Controlled Pd(0)/t Bu3P Catalyzed Suzuki Cross-Coupling Polymerization of AB-Type Monomers with ArPd(t Bu3P)X or Pd2(dba)3/t Bu3P/ArX as the Initiator

    DOE PAGES

    Zhang, Honghai; Xing, Chun-Hui; Hu, Qiao-Sheng; ...

    2015-02-05

    The synthesis of well-defined and functionalized conjugated polymers, which are essential in the development of efficient organic electronics, through Suzuki cross-coupling polymerizations has been a challenging task. We developed controlled Pd(0)/t-Bu3P-catalyzed Suzuki cross-coupling polymerizations of AB-type monomers via the chain-growth mechanism with a series of in situ generated ArPd(t-Bu3P)X (X = I, Br, Cl) complexes as initiators. Among them, the combinations of Pd2(dba)3/t-Bu3P/p-BrC6H4I, Pd2(dba)3/t-Bu3P/p-BrC6H4CH2OH and Pd2(dba)3/t-Bu3P/p-PhCOC6H4Br were identified as highly robust initiator systems, resulting in polymers with predictable molecular weight and narrow polydispersity (PDI~1.13-1.20). In addition, Pd2(dba)3/t-Bu3P/p-BrC6H4CH2OH and Pd2(dba)3/t-Bu3P/p-PhCOC6H4Br initiator systems afforded functional polymers with >95% fidelity. Our results pavedmore » the road to access well-defined conjugated polymers, including conjugated polymers with complex polymer architectures such as block copolymers and branch copolymers.« less

  8. 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

  9. SL12-GADRAS-PD2Ka Annual Report

    SciTech Connect

    Mitchell, Dean J.

    2014-09-09

    The GADRAS Development project comprises several elements that are all related to the Detector Response Function (DRF), which is the core of GADRAS. An ongoing activity is implementing continuous improvements in the accuracy and versatility of the DRF. The ability to perform rapid computation of the response of gammaray detectors for 3-D descriptions of source objects and their environments is a good example of a recent utilization of this versatility. The 3-D calculations, which execute several orders of magnitude faster than competing techniques, compute the response as an extension of the DRF so the radiation transport problem is never solvedmore » explicitly, thus saving considerable computational time. Maintenance of the Graphic User Interface (GUI) and extension of the GUI to enable construction of the 3-D source models is included in tasking for the GADRAS Development project. Another aspect of this project is application of the isotope identification algorithms for search applications. Specifically, SNL is tasked with development of an isotope-identification based search capability for use with the RSL-developed AVID system, which supports simultaneous operation of numerous radiation search assets. A Publically Available (PA) GADRAS-DRF application, which eliminates sensitive analysis components, will soon be available so that the DRF can be used by researchers at universities and corporations.« less

  10. Materials Data on Ca5P12Rh19 (SG:189) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  11. Materials Data on Ca5(SnAs3)2 (SG:55) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  12. Reduction of Selenite to Elemental Red Selenium by Pseudomonas sp. strain CA5

    USDA-ARS?s Scientific Manuscript database

    A Pseudomonas sp. that may be useful in bioremediation projects was isolated from soil. The strain is of potential value because it reduces selenite to elemental red selenium and is unusual in that it was resistant to high concentrations of both selenate and selenite. Cell of the strain removed 1....

  13. Fascinating Foam - Diverse Applications, Unexpected Properties, and Characterization Challenges (PD2P Talk)

    SciTech Connect

    Kropka, Jamie M.

    2009-09-24

    Foam pervades our everyday lives: we use it to bathe and shave, it floats atop our beer, cappuccino and pie, and it can even infect our bodies in the form of viruses. Although we are able to manipulate foam in these and many other common practices, there is still much we do not know about this fascinatingly complex material. In this talk, some of the intriguing aspects of foam, which could not be predicted based on its constituent components, will be discussed. Some challenging aspects of foam characterization, which have impeded the development of a thorough understanding of the materialmore » despite over a century of investigations, will also be presented. Despite these challenges, there are some known aspects of foams and these will be outlined along with how today's modern tools are being utilized to tell us more about foam structure and dynamics. A brief introduction to Sandia's interest in foams will then be given, and some of the current research we are conducting to further those interests will be discussed. This work is focused on the preparation of 'model' organic foams for use in developing an understanding of how to tune their stability and rheological response. Finally, physical and chemical methods to stabilize the foam will be described and possible new directions for the work will be presented.« less

  14. Materials Data on U(SiPd)2 (SG:139) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2016-02-10

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  15. Materials Data on U(GePd)2 (SG:139) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2016-02-05

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  16. Materials Data on Y(SiPd)2 (SG:139) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  17. Materials Data on Y5(In2Pd)2 (SG:55) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-11

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  18. Materials Data on Ba(AsPd)2 (SG:123) by Materials Project

    SciTech Connect

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  19. Materials Data on Ca(GePd)2 (SG:139) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  20. Materials Data on Tb(SiPd)2 (SG:139) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  1. Materials Data on Tb(GePd)2 (SG:139) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2016-04-04

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  2. TRAC-PD2 posttest analysis of the CCTF Evaluation-Model Test C1-19 (Run 38). [PWR

    SciTech Connect

    Motley, F.

    The results of a Transient Reactor Analysis Code posttest analysis of the Cylindral Core Test Facility Evaluation-Model Test agree very well with the results of the experiment. The good agreement obtained verifies the multidimensional analysis capability of the TRAC code. Because of the steep radial power profile, the importance of using fine noding in the core region was demonstrated (as compared with poorer results obtained from an earlier pretest prediction that used a coarsely noded model).

  3. LL13-MatModelRadDetect-PD2Jf Final Report: Materials Modeling for High-Performance Radiation Detectors

    SciTech Connect

    Lordi, Vincenzo

    The aims of this project are to enable rational materials design for select high-payoff challenges in radiation detection materials by using state-of-the-art predictive atomistic modeling techniques. Three specific high-impact challenges are addressed: (i) design and optimization of electrical contact stacks for TlBr detectors to stabilize temporal response at room-temperature; (ii) identification of chemical design principles of host glass materials for large-volume, low-cost, highperformance glass scintillators; and (iii) determination of the electrical impacts of dislocation networks in Cd 1-xZn xTe (CZT) that limit its performance and usable single-crystal volume. The specific goals are to establish design and process strategies to achievemore » improved materials for high performance detectors. Each of the major tasks is discussed below in three sections, which include the goals for the task and a summary of the major results, followed by a listing of publications that contain the full details, including details of the methodologies used. The appendix lists 12 conference presentations given for this project, including 1 invited talk and 1 invited poster.« less

  4. OR14-V-Uncertainty-PD2La Uncertainty Quantification for Nuclear Safeguards and Nondestructive Assay Final Report

    SciTech Connect

    Nicholson, Andrew D.; Croft, Stephen; McElroy, Robert Dennis

    2017-08-01

    The various methods of nondestructive assay (NDA) of special nuclear material (SNM) have applications in nuclear nonproliferation, including detection and identification of illicit SNM at border crossings and quantifying SNM at nuclear facilities for safeguards. No assay method is complete without “error bars,” which provide one way of expressing confidence in the assay result. Consequently, NDA specialists typically provide error bars and also partition total uncertainty into “random” and “systematic” components so that, for example, an error bar can be developed for the total mass estimate in multiple items. Uncertainty Quantification (UQ) for NDA has always been important, but itmore » is recognized that greater rigor is needed and achievable using modern statistical methods.« less

  5. Gram-Scale Synthesized Pd2Co-Supported PtMonolayers Electrocatalysts for Oxygen Reduction Reaction

    SciTech Connect

    Zhou, W.P.; Sasaki, K.; Su, D.

    2010-04-21

    Gram-scale synthesis of Pt{sub ML} electrocatalysts with a well-defined core-shell structure has been carried out using method involving galvanic displacement of an underpotential deposition Cu layer. The Pt shell thickness can be controlled by stepwise deposition. The Pt{at}Pd{sub 2}Co/C nanoparticles were characterized by X-ray powder diffraction, aberration-corrected scanning transmission electron microscopy, high-resolution energy-loss spectrometry, and in situ X-ray absorption spectroscopy. A complete Pt shell of 0.6 nm on a Pd{sub 2}Co core has been confirmed. The Pt{at}Pd{sub 2}Co/C core-shell electrocatalysts showed a very high activity for the oxygen reduction reaction; the Pt mass and specific activity were 0.72 A mg{supmore » -1}{sub Pt} and 0.5 mA cm{sup -2}, respectively (3.5 and 2.5 times higher than the corresponding values for commercial Pt catalysts), at 0.9 V in 0.1 M HClO{sub 4} at room temperature. In an accelerated potential cycling test, a loss in active surface area and a decrease in catalytic activity for gram-scale-synthesized Pt{sub ML} catalysts were also determined.« less

  6. Pseudomonas sp. strain CA5 (a selenite-reducing bacterium) 16S rRNA gene complete sequence. National Institute of Health, National Center for Biotechnology Information, GenBank sequence. Accession FJ422810.1.

    USDA-ARS?s Scientific Manuscript database

    This study used 1321 base pair 16S rRNA gene sequence methods to confirm the phylogenetic position of a soil isolate as a bacterium belonging to the genus Pesudomonas sp. Morphological, biochemical characteristics, and fatty acid profiles are consistent with the 16S rRNA gene sequence identification...

  7. Results of a 0.03- scale aerodynamic characteristics investigation of Boeing 747 carrier (model no. AX 1319 I-1) mated with a space shuttle orbiter (model 45-0) conducted in the Boeing transonic wind tunnel (CA5), volume 1

    NASA Technical Reports Server (NTRS)

    Sarver, D.; Mulkey, T. L.; Lindahl, R. H.

    1975-01-01

    The performance, stability, and control characteristics of various carrier aircraft configurations are presented. Aerodynamic characteristics of the carrier mated with the Orbiter, carrier alone, and Orbiter alone were investigated. Carrier support system tare and interference effects were determined. Six-component force and moment data were recorded for the carrier and Orbiter. Buffet onset characteristics of the carrier vertical tail and horizontal tail were recorded. Angles of attack from -3 deg through 26 deg and angles of slideslip between +12 deg and -12 deg were investigated at Mach numbers from 0.15 through 0.70. Photographs are included.

  8. Responses of the aorta of the garter snake (Thamnophis sirtalis parietalis) to purines.

    PubMed Central

    Knight, G E; Burnstock, G

    1995-01-01

    1. Isolated aortic rings from the garter snake (Thamnophis sirtalis parietalis) were investigated in order to identify and classify responses to adenosine and adenosine 5'-triphosphate (ATP) and their analogues as part of a comparative study of vertebrate purinoceptors. 2. Adenosine, D-5'-(N-ethylcarboxamide) adenosine (NECA), R- and S-N6-(2-phenylisopropyl) adenosine (R- and S-PIA) and 2-chloroadenosine (2-CA) all concentration-dependently relaxed aorta preconstricted with noradrenaline (NA). The order of potency was: NECA > R-PIA = 2-CA > adenosine > S-PIA. Individual pD2 values for the analogues were: NECA 7.12 +/- 0.13 (9), R-PIA 5.93 +/- 0.25 (7), 2-CA 5.64 +/- 0.40 (5), adenosine 5.04 +/- 0.10 (13) and S-PIA 4.26 +/- 0.10 (7). The order of potency has characteristics of both A1 and A2 receptors and cannot satisfactorily be classified according to the P1-(adenosine) purinoceptor subtypes established in mammalian preparations. 3. ATP, alpha, beta-methylene ATP (alpha, beta-MeATP), 2-methylthio ATP (2MeSATP), beta, gamma-methylene ATP (beta, gamma,-MeATP) and uridine 5'-triphosphate (UTP) all concentration-dependently constricted the isolated aorta. The order of potency was alpha, beta-MeATP = 2MeSATP > ATP > beta, gamma-MeATP > UTP. Only ATP, alpha, beta-MeATP and 2MeSATP consistently produced a maximum response; pD2 values were: ATP 3.98 +/- 0.07 (10), alpha, beta-MeATP 5.86 +/- 0.15 (12) and 2MeSATP 6.06 +/- 0.23 (9). In vessels preconstricted with NA neither ATP nor 2MeSATP caused relaxation in the presence or absence of the endothelium.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7712027

  9. From Structural Complexity to Structure-Property Relationships in Intermetallics: Development of Density Functional Theory-Chemical Pressure Analysis

    NASA Astrophysics Data System (ADS)

    Engelkemier, Joshua

    away from each other (negative CP). This technique is used in combination with the concept of structural plasticity (Berns, 2014) to demonstrate how complex intermetallic phases can be understood as a response of simpler structure types to the destabilizing buildup of CP. From this point of view, interfaces created in complex structures relieve the CP manifest in the more basic, parent structures. This is shown specifically for Ca36Sn23 relative to a hypothetical W5Si3-type Ca5Sn3 phase, LnMn xGa3 (Ln = Ho-Tm, x < 0.15) compared to unstuffed AuCu3-type LnGa3 structures, and structural derivatives of CaCu5- and HoCoGa5-type compounds. As a direct result of the technical developments necessitated by these analyses on structural complexity in intermetallics, a further connection is made in this thesis between the calculated CP schemes and the frequencies of vibrational modes in MgCu2-type CaPd2, the Cr 3Si-type superconductor Nb3Ge, and CaCu5-type CaPd5. Local chemical interactions revealed by DFT-CP analysis are used to identify structure-property relationships for the pseudogap in the phonon density of states (DOS) of CaPd2, the higher critical temperature of Nb3Ge vs. Nb3Sn, and the wide diversity of structures based on the CaCu5 type.

  10. Evaluation of the active functional groups and structural rearrangement of parthenolide derivatives on their potential anticancer activity

    NASA Astrophysics Data System (ADS)

    Srakaew, Veeranuch; Tachaboonyakiat, Wanpen

    2017-05-01

    Two parthenolide derivatives (PDs) were synthesized by chemical modification of parthenolide with concentrated hydrochloric acid and to evaluate their cytotoxicity to Hep-G2 cells in terms of their active functional groups and polarity. The chemical structures of the PDs were characterized by Fourier transform infrared, nuclear magnetic resonance and high resolution mass spectroscopy. Two PDs (PD1 and PD2) were fractionated by silica gel column chromatography with a Rf of 0.37 and 0.19, respectively, in a 1:1 (v/v) hexane: ethyl acetate mobile phase, indicating that PD1 was less polar than PD2. Compared to the parent parthenolide, both PD1 and PD2 had lost the active carbon-carbon double bond and epoxide functional groups, but retained the active 14-methyl and α-methylene-γ-butyrolactone groups. Although PD1 and PD2 possessed similar functional groups, they differed in their structural arrangement and consequentially their polarity. PD1 and PD2 exhibited an in vitro IC50 against the Hep-G2 cell line of 41.0 and 94.0 μg/ml, respectively, which was weaker than that for parthenolide (<1 μg/ml). Thus, the ranked polarity of PD2 > PD1 > parthenolide was inversely related to their cytotoxicity against the Hep-G2 cell line (parthenolide > PD1 > PD2). The obtained PDs may be potential novel anticancer substances.

  11. Zintl Phases for Thermoelectric Applications

    NASA Technical Reports Server (NTRS)

    Snyder, G. Jeffrey (Inventor); Toberer, Eric (Inventor); Zevalkink, Alex (Inventor)

    2014-01-01

    The inventors demonstrate herein that various Zintl compounds can be useful as thermoelectric materials for a variety of applications. Specifically, the utility of Ca3AlSb3, Ca5Al2Sb6, Ca5In2Sb6, Ca5Ga2Sb6, is described herein. Carrier concentration control via doping has also been demonstrated, resulting in considerably improved thermoelectric performance in the various systems described herein.

  12. Possible nucleus of the Bergman cluster in the Zn-Mg-Y alloy system

    NASA Astrophysics Data System (ADS)

    Nakayama, Kei; Nakagawa, Masaya; Koyama, Yasumasa

    2018-01-01

    To understand the formation of the Bergman cluster in the F-type icosahedral quasicrystal (IQ), crystallographic relations between the quasicrystal and the intermetallic-compound H and Zn23Y6 phases in the Zn-Mg-Y alloy system were investigated mainly by transmission electron microscopy. It was found that, although sample rotations of about 1° were required to obtain simple crystallographic relations, the orientation relationship was established among the cubic-Fm?m Zn23Y6 structure, the hexagonal-P63/mmc H structure and the F-type IQ; that is, [? 1 3]c // the five-fold axis in the IQ // N(2 ? 0)H, and [1 1 0]c // the two-fold axis in the IQ // N(0 5 ? 3)H, where N(h k m l)H means the normal direction of the (h k m l)H plane in the H structure. The correspondences between atomic positions in the Bergman cluster and in the Zn23Y6 structure and between those in the cluster and in the H structure were investigated on the basis of the established relationship. As a result, an assembly of six short-penetrated-decagonal columns was identified as an appropriate nucleus in the formation of the Bergman cluster from these two structures.

  13. What dictates which ion, I- or Br-, mediates the growth of cubic Pd nanocrystals?

    PubMed

    Wang, Ze-Hong; Wu, Ya-Jiao; Xue, Huan-Huan; Zhou, Lin-Nan; Geng, Wen-Chao; Yi, Hai-Bo; Li, Yong-Jun

    2018-04-25

    Cubic Pd nanocrystals (CPNCs) as one of typical nanostructures are generally fabricated using I- or Br- as capping ions. However, which ion, I- or Br-, exclusively mediates the growth of CPNCs in a given reaction system is not well understood. Herein, regardless of I- or Br- as the capping ion, we successfully achieved CPNCs in the same reaction system simply by adjusting the pH. Based on the Finke-Watzky kinetic model, an increase in pH accelerates the overall reduction rate of Pd2+, and the formation of CPNCs only occurs over the range of specific solution reduction rate constants (k1). This kinetically illuminates that the reduction rate of Pd2+ is the physicochemical parameter that determines which ion, I- or Br-, dictates the growth of CPNCs. Also, density functional theory (DFT) calculations further elucidate the dependence of the reduction rate of Pd2+ on pH and the configuration of the activated Pd2+ complex.

  14. Anti-Invasive and Anti-Proliferative Synergism between Docetaxel and a Polynuclear Pd-Spermine Agent

    PubMed Central

    Batista de Carvalho, Ana L. M.; Medeiros, Paula S. C.; Costa, Francisco M.; Ribeiro, Vanessa P.; Sousa, Joana B.; Marques, Maria P. M.

    2016-01-01

    The present work is aimed at evaluating the antitumour properties of a Pd(II) dinuclear complex with the biogenic polyamine spermine, by investigating: i) the anti-angiogenic and anti-migration properties of a Pd(II) dinuclear complex with spermine (Pd2Spm); ii) the anti-proliferative activity of Pd2Spm against a triple negative human breast carcinoma (MDA-MB-231); and finally iii) the putative interaction mediated by combination of Pd2Spm with Docetaxel. Anti-invasive (anti-angiogenic and anti-migratory) as well as anti-proliferative capacities were assessed, for different combination schemes and drug exposure times, using the CAM assay and VEGFR2 activity measurement, the MatrigelTM method and the SRB proliferation test. The results thus obtained evidence the ability of Pd2Spm to restrict angiogenesis and cell migration: Pd2Spm induced a marked inhibition of migration (43.8±12.2%), and a higher inhibition of angiogenesis (81.8±4.4% for total length values, at 4 μM) as compared to DTX at the clinical dosage 4x10-2 μM (26.4±14.4%; n = 4 to 11). Combination of Pd2Spm/DTX was more effective as anti-invasive and anti-proliferative than DTX or Pd2Spm in sole administration, which is compatible with the occurrence of synergism: for the anti-angiogenic effect, IC50(Pd2Spm/DTX) = 0.5/0.5x10-2 μM vs IC50(DTX) = 1.7x10-2 μM and IC50(Pd2Spm) = 1.6 μM. In conclusion, the reported effects of Pd2Spm on angiogenesis, migration and proliferation showed that this compound is a promising therapeutic agent against this type of breast cancer. Moreover, combined administration of Pd2Spm and DTX was found to trigger a substantial synergetic effect regarding angiogenesis inhibition as well as anti-migratory and anti-proliferative activities reinforcing the putative use of Pd(II) complexes in chemotherapeutic regimens. This is a significant outcome, aiming at the application of these combined strategies towards metastatic breast cancer (or other type of resistant cancers

  15. Magnetization and transport properties of single crystalline RPd 2P 2 (R=Y, La–Nd, Sm–Ho, Yb)

    DOE PAGES

    Drachuck, Gil; Böhmer, Anna E.; Bud'ko, Sergey L.; ...

    2016-05-27

    Single crystals of RPd 2P 2 (R=Y, La–Nd, Sm–Ho, Yb) were grown out of a high temperature solution rich in Pd and P and characterized by room-temperature powder X-ray diffraction, anisotropic temperature- and field-dependent magnetization and temperature-dependent in-plane resistivity measurements. In this series, YPd 2P 2 and LaPd 2P 2 YbPd 2P 2 (with Yb 2+) are non-local-moment bearing. Furthermore, YPd 2P 2 and LaPd 2P 2 are found to be superconducting with Tc≃0.75 and 0.96 K respectively. CePd 2P 2 and PrPd 2P 2 magnetically order at low temperature with a ferromagnetic component along the crystallographic c-axis. The rest of the series manifest low temperature antiferromagnetic ordering. EuPd 2P 2 has Eu 2+ ions and both EuPd 2P 2 and GdPd 2P 2 have isotropic paramagnetic susceptibilities consistent with L =0 and J=S=more » $$\\frac{7}{2}$$ and exhibit multiple magnetic transitions. For R=Eu–Dy, there are multiple, T>1.8 K transitions in zero applied magnetic field and for R=Nd, Eu, Gd, Tb, and Dy there are clear metamagnetic transitions at T=2.0 K for H< 55 kOe. Strong anisotropies arising mostly from crystal electric field (CEF) effects were observed for most magnetic rare earths with L≠0. The experimentally estimated CEF parameters B$$_2^0$$ were calculated from the anisotropic paramagnetic θ ab and θ c values and compared to theoretical trends across the rare earth series. Lastly, the ordering temperatures as well as the polycrystalline averaged paramagnetic Curie–Weiss temperature, θ ave, were extracted from magnetization and resistivity measurements, and compared to the de-Gennes factor.« less

  16. Magnetization and transport properties of single crystalline RPd 2P 2 (R=Y, La–Nd, Sm–Ho, Yb)

    SciTech Connect

    Drachuck, Gil; Böhmer, Anna E.; Bud'ko, Sergey L.

    Single crystals of RPd 2P 2 (R=Y, La–Nd, Sm–Ho, Yb) were grown out of a high temperature solution rich in Pd and P and characterized by room-temperature powder X-ray diffraction, anisotropic temperature- and field-dependent magnetization and temperature-dependent in-plane resistivity measurements. In this series, YPd 2P 2 and LaPd 2P 2 YbPd 2P 2 (with Yb 2+) are non-local-moment bearing. Furthermore, YPd 2P 2 and LaPd 2P 2 are found to be superconducting with Tc≃0.75 and 0.96 K respectively. CePd 2P 2 and PrPd 2P 2 magnetically order at low temperature with a ferromagnetic component along the crystallographic c-axis. The rest of the series manifest low temperature antiferromagnetic ordering. EuPd 2P 2 has Eu 2+ ions and both EuPd 2P 2 and GdPd 2P 2 have isotropic paramagnetic susceptibilities consistent with L =0 and J=S=more » $$\\frac{7}{2}$$ and exhibit multiple magnetic transitions. For R=Eu–Dy, there are multiple, T>1.8 K transitions in zero applied magnetic field and for R=Nd, Eu, Gd, Tb, and Dy there are clear metamagnetic transitions at T=2.0 K for H< 55 kOe. Strong anisotropies arising mostly from crystal electric field (CEF) effects were observed for most magnetic rare earths with L≠0. The experimentally estimated CEF parameters B$$_2^0$$ were calculated from the anisotropic paramagnetic θ ab and θ c values and compared to theoretical trends across the rare earth series. Lastly, the ordering temperatures as well as the polycrystalline averaged paramagnetic Curie–Weiss temperature, θ ave, were extracted from magnetization and resistivity measurements, and compared to the de-Gennes factor.« less

  17. 29 CFR 779.118 - Employees providing central services for multi-unit organizations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Employees providing central services for a multiunit organization may be engaged both “in commerce” and “in... and clerical work relating to such activities) for various retail units of a chain are covered under..., affirming, 128 F. 2d 935 (CA-5); Mitchell v. C. & P. Stores, 286 F. 2d 109 (CA-5); Mitchell v. E. G. Shinner...

  18. 29 CFR 779.118 - Employees providing central services for multi-unit organizations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... Employees providing central services for a multiunit organization may be engaged both “in commerce” and “in... and clerical work relating to such activities) for various retail units of a chain are covered under..., affirming, 128 F. 2d 935 (CA-5); Mitchell v. C. & P. Stores, 286 F. 2d 109 (CA-5); Mitchell v. E. G. Shinner...

  19. 29 CFR 779.118 - Employees providing central services for multi-unit organizations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... Employees providing central services for a multiunit organization may be engaged both “in commerce” and “in... and clerical work relating to such activities) for various retail units of a chain are covered under..., affirming, 128 F. 2d 935 (CA-5); Mitchell v. C. & P. Stores, 286 F. 2d 109 (CA-5); Mitchell v. E. G. Shinner...

  20. 29 CFR 779.118 - Employees providing central services for multi-unit organizations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... Employees providing central services for a multiunit organization may be engaged both “in commerce” and “in... and clerical work relating to such activities) for various retail units of a chain are covered under..., affirming, 128 F. 2d 935 (CA-5); Mitchell v. C. & P. Stores, 286 F. 2d 109 (CA-5); Mitchell v. E. G. Shinner...

  1. 29 CFR 779.118 - Employees providing central services for multi-unit organizations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... Employees providing central services for a multiunit organization may be engaged both “in commerce” and “in... and clerical work relating to such activities) for various retail units of a chain are covered under..., affirming, 128 F. 2d 935 (CA-5); Mitchell v. C. & P. Stores, 286 F. 2d 109 (CA-5); Mitchell v. E. G. Shinner...

  2. High Density Schottky Barrier Infrared Charge-Coupled Device (IRCCD) Sensors For Short Wavelength Infrared (SWIR) Applications At Intermediate Temperature

    NASA Astrophysics Data System (ADS)

    Elabd, H.; Villani, T. S.; Tower, J. R.

    1982-11-01

    Monolithic 32 x 64 and 64 x 128 palladium silicide (Pd2Si) interline transfer IRCCDs sensitive in the 1-3.5 pm spectral band have been developed. This silicon imager exhibits a low response nonuniformity of typically 0.2-1.6% rms, and has been operated in the temperature range between 40-140K. Spectral response measurements of test Pd2Si p-type Si devices yield quantum efficiencies of 7.9% at 1.25 μm, 5.6% at 1.65 μm and 2.2% at 2.22 μm. Improvement in quantum efficiency is expected by optimizing the different structural parameters of the Pd2Si detectors. The spectral response of the Pd2Si detectors fit a modified Fowler emission model. The measured photo-electric barrier height for the Pd2Si detector is ≍0.34 eV and the measured quantum efficiency coefficient, C1, is 19%/eV. The dark current level of Pd2Si Schottky barrier focal plane arrays (FPAs) is sufficiently low to enable operation at intermediate tem-peratures at TV frame rates. Typical dark current level measured at 120K on the FPA is 2 nA/cm2. The Pd2Si Schottky barrier imaging technology has been developed for satellite sensing of earth resources. The operating temperature of the Pd2Si FPA is compatible with passive cooler performance. In addition, high density Pd2Si Schottky barrier FPAs are manufactured with high yield and therefore represent an economical approach to short wavelength IR imaging. A Pd2Si Schottky barrier image sensor for push-broom multispectral imaging in the 1.25, 1.65, and 2.22 μm bands is being studied. The sensor will have two line arrays (dual band capability) of 512 detectors each, with 30 μm center-to-center detector spacing. The device will be suitable for chip-to-chip abutment, thus providing the capability to produce large, multiple chip focal planes with contiguous, in-line sensors.

  3. High density Schottky barrier IRCCD sensors for SWIR applications at intermediate temperature

    NASA Technical Reports Server (NTRS)

    Elabd, H.; Villani, T. S.; Tower, J. R.

    1982-01-01

    Monolithic 32 x 64 and 64 x 1:128 palladium silicide (Pd2Si) interline transfer infrared charge coupled devices (IRCCDs) sensitive in the 1 to 3.5 micron spectral band were developed. This silicon imager exhibits a low response nonuniformity of typically 0.2 to 1.6% rms, and was operated in the temperature range between 40 to 140 K. Spectral response measurements of test Pd2Si p-type Si devices yield quantum efficiencies of 7.9% at 1.25 microns, 5.6% at 1.65 microns 2.2% at 2.22 microns. Improvement in quantum efficiency is expected by optimizing the different structural parameters of the Pd2Si detectors. The spectral response of the Pd2Si detectors fit a modified Fowler emission model. The measured photo-electric barrier height for the Pd2Si detectors is 0.34 eV and the measured quantum efficiency coefficient, C1, is 19%/eV. The dark current level of Pd2Si Schottky barrier focal plane arrays (FPAs) is sufficiently low to enable operation at intermediate temperatures at TV frame rates. Typical dark current level measured at 120 K on the FPA is 2 nA/sq cm. The operating temperature of the Pd2Si FPA is compatible with passive cooler performance. In addition, high density Pd2Si Schottky barrier FPAs are manufactured with high yield and therefore represent an economical approach to short wavelength IR imaging. A Pd2Si Schottky barrier image sensor for push-broom multispectral imaging in the 1.25, 1.65, and 2.22 micron bands is being studied. The sensor will have two line arrays (dual band capability) of 512 detectors each, with 30 micron center-to-center detector spacing. The device will be suitable for chip-to-chip abutment, thus providing the capability to produce large, multiple chip focal planes with contiguous, in-line sensors.

  4. Mechanisms underlying the relaxant effect of Galetin 3,6- dimethyl ether, from Piptadenia stipulacea (Benth.) Ducke, on guinea-pig trachea.

    PubMed

    Macêdo, Cibério Landim; Vasconcelos, Luiz Henrique César; Correia, Ana Carolina de Carvalho; Martins, Italo Rossi Roseno; Lira, Daysianne Pereira de; Santos, Bárbara Viviana de Oliveira; Silva, Bagnólia Araújo da

    2014-01-01

    Galetin 3,6-dimethyl ether (FGAL), a flavonoid from the aerial parts of Piptadenia stipulacea (Benth.) Ducke, was found to exert a relaxant effect on carbachol (CCh)-pre-contracted guinea-pig trachea. Based on cumulative concentration-response curves to CCh, FGAL antagonized muscarinic receptors pseudo-irreversibly and noncompetitively, since it inhibited and shifted these curves towards higher concentrations in a nonparallel manner. In addition, FGAL was more potent in relaxing contractions induced by 18 mM as compared to 60 mM KCl (pD2 = 5:50 ±0:36 and 4.80 ±0.07, respectively), indicating the participation of K+ channels. In the presence of 10 mM tetraethylammonium (TEA+) chloride, a nonselective K+ channel blocker, the relaxant potency of FGAL was reduced (from pD2 = 5:12 ±0:07 to 4.87 ±0.02). Among several selective blockers of K+ channel subtypes, only apamin, an SKCa (small-conductance Ca2+-activated K+ channels) blocker, attenuated the relaxant potency of FGAL (pD2 = 4:85±0:06), suggesting SKCa activation. FGAL was equipotent in relaxing trachea contracted by 60 mM KCl (pD2 =4:80 ±0:07) or 10-6 M CCh (pD2 = 5:02 ±0:07), suggesting CaV (voltage-gated calcium channel), but not ROCs (receptor-operated calcium channels) participation. Furthermore, aminophylline-induced relaxation (pD2 = 4:12 ±0:06) was potentiated around 4-fold (pD2 = 4:80 ±0:44) in the presence of FGAL. Moreover, forskolininduced relaxation (pD2 = 6:51 ±0:06) was potentiated around 2.5-fold (pD2 = 6:90 ±0:05) by FGAL. Conversely, sodium nitroprusside-induced relaxation was unaffected, indicating that the AC/cAMP/PKA pathway, but not the NO pathway, may be modulated by the flavonoid. These results suggest that, in guinea-pig trachea, FGAL induces relaxation by pseudo-irreversible noncompetitive antagonism on muscarinic receptors, modulation of K+ and Ca2+ channels, as well as activation of the AC/cAMP/PKA pathway.

  5. Electrodermal complexity during the Stroop colour word test.

    PubMed

    Svetlak, Miroslav; Bob, Petr; Cernik, Michal; Kukleta, Miloslav

    2010-01-15

    Several recent studies suggest that quantitative description of signal complexity using algorithms of nonlinear analysis could uncover new information about the autonomic system that is not reflected using common methods applied to measures of autonomic activity. With this aim we have performed complexity analysis of electrodermal activity (EDA) assessed in 106 healthy university students during rest conditions and non-conflicting and conflicting Stroop task. Complexity analysis applied to EDA was performed using Skinner's algorithm for pointwise correlation dimension (PD2). Results have shown that EDA responses during the Stroop Colour Word test are related to significantly increased or decreased complexity. Particularly significant result is that PD2 has a unique ability to predict to an extent the change in EDA response to stress i.e. that subjects with low initial PD2 tended to respond to experimental stress by its increase and subjects with high initial PD2 values tended to respond by its decrease. This response was not found in EDA measures where increase of the EDA presented predominant response to experimental stress in majority of the subjects. These findings suggest that PD2 is more sensitive to subtle aspects of functionally and spatially distributed modulatory influences of various parts of the brain that are involved in the EDA modulation and provides novel information in comparison to traditional methods.

  6. Selective hydrogenation of acetylene in the presence of ethylene on palladium nanocluster surfaces: A DFT study

    NASA Astrophysics Data System (ADS)

    Abdollahi, Tahereh; Farmanzadeh, Davood

    2018-03-01

    In this work, by density functional theory, the palladium nanoclusters were investigated in order to design new catalysts for the selective hydrogenation of acetylene present in olefin feeds. At first, the palladium nanoclusters were studied using PBE-G functional with DNP-ECP basis set. According to the performed calculations, among all the Pdn (n = 2-15) nanoclusters, two Pd12 and Pd2 nanoclusters can be used as catalysts in the reactions of hydrogenation of acetylene and ethylene. The adsorption energy of hydrogen on the Pd12 nanocluster is higher than that of acetylene and ethylene, and therefore, the Pd12 nanocluster is more appropriate for the hydrogenation of acetylene and ethylene. However, the calculated activation energy barriers for the reactions of hydrogenation of acetylene and ethylene showed that the Pd2 nanocluster has more selectivity in comparison to the Pd12 nanocluster. According to our results, the activation energy of the hydrogenation of acetylene to vinyl on the Pd2 nanocluster is 23.96 kJ/mol lower than that on the Pd12 nanocluster. Also, the activation energy of the hydrogenation of ethylene to ethyl on the Pd2 nanocluster is higher than that on the Pd12 nanocluster Therefore, it seems that the Pd2 surface can be used as a catalyst for the selective hydrogenation of acetylene.

  7. PdnCO (n = 1,2): accurate Ab initio bond energies, geometries, and dipole moments and the applicability of density functional theory for fuel cell modeling.

    PubMed

    Schultz, Nathan E; Gherman, Benjamin F; Cramer, Christopher J; Truhlar, Donald G

    2006-11-30

    Electrode poisoning by CO is a major concern in fuel cells. As interest in applying computational methods to electrochemistry is increasing, it is important to understand the levels of theory required for reliable treatments of metal-CO interactions. In this paper we justify the use of relativistic effective core potentials for the treatment of PdCO and hence, by inference, for metal-CO interactions where the predominant bonding mechanism is charge transfer. We also sort out key issues involving basis sets and we recommend that bond energies of 17.2, 43.3, and 69.4 kcal/mol be used as the benchmark bond energy for dissociation of Pd2 into Pd atoms, PdCO into Pd and CO, and Pd2CO into Pd2 and CO, respectively. We calculated the dipole moments of PdCO and Pd2CO, and we recommend benchmark values of 2.49 and 2.81 D, respectively. Furthermore, we tested 27 density functionals for this system and found that only hybrid density functionals can qualitatively and quantitatively predict the nature of the sigma-donation/pi-back-donation mechanism that is associated with the Pd-CO and Pd2-CO bonds. The most accurate density functionals for the systems tested in this paper are O3LYP, OLYP, PW6B95, and PBEh.

  8. Electrical conductivity and phase diagram of binary alloys. 21: The system palladium-chromium

    NASA Technical Reports Server (NTRS)

    Grube, G.; Knabe, R.

    1985-01-01

    Pd-Cr alloys were investigated by thermal analysis, hardness measurements, X-ray analysis, microscopic examination of etched pieces, and temperature-resistance curves of the solid alloys. Only one compound, Pd2Cr3, m, 1389 deg, is formed. It possesses a cubic face centered lattice and forms with excess Pd a series of solid solutions with a minimum m.p. at 45 atoms% Pd. Hardness maximum appears at the Pd2Cr3 point. Pd2Cr3 forms no solid solutions with Cr but eutectic point appears at 25 atoms% Pd, m. 1320 deg. The sp. resistance of pure Cr in an atom of H, indicates no allotropic forms. Cr2O3 is solid in molten Cr. Pure Cr melts at 1890 plus or minus 10 deg but Cr contg. Cr2O3 starts to melt at 1770 to 1790 deg.

  9. Optimizing the ORR activity of Pd based nanocatalysts by tuning their strain and particle size

    DOE PAGES

    Xiao, Weiping; Liutheviciene Cordeiro, Marco Aurelio; Gong, Mingxing; ...

    2017-04-18

    Controlling of the particle size and surface strain is the key to tuning the surface chemistry and optimizing the catalytic performance of electrocatalysts. In this study, we show that by introducing both Fe and Co into Pd lattices, the surface strain of Pd nanocatalysts can be tuned to optimize their oxygen reduction activity in both fuel cells and Zn–air batteries. The Pd 2FeCo/C alloy particles are uniquely coated with an ultrathin Fe 2O 3 shell which is in situ formed during a thermal annealing treatment. The thin shell acts as an effective barrier that prevents the coalescence and ripening ofmore » Pd 2FeCo/C nanoparticles. Compared with Pd/C, Pd 2FeCo/C exhibits higher catalytic activity and long-term stability for the ORR, signifying changes in catalytic behavior due to particle sizes and strain effects. Moreover, by spontaneous decoration of Pt on the surface of Pd 2FeCo/C, the Pd 2FeCo@Pt/C core@shell structure was formed and the Pt mass activity was about 37.6 and 112.5 times higher than that on Pt/C in a 0.1 M HClO 4 and KOH solution at 0.9 V, respectively, suggesting an enhanced ORR performance after Pt decoration. More interestingly, Pd 2FeCo@Pt/C also shows a power density of ~308 mW cm -2, which is much higher than that of Pt/C (175 mW cm -2), and excellent durability in a home-made Zn–air battery.« less

  10. Optimizing the ORR activity of Pd based nanocatalysts by tuning their strain and particle size

    SciTech Connect

    Xiao, Weiping; Liutheviciene Cordeiro, Marco Aurelio; Gong, Mingxing

    Controlling of the particle size and surface strain is the key to tuning the surface chemistry and optimizing the catalytic performance of electrocatalysts. In this study, we show that by introducing both Fe and Co into Pd lattices, the surface strain of Pd nanocatalysts can be tuned to optimize their oxygen reduction activity in both fuel cells and Zn–air batteries. The Pd 2FeCo/C alloy particles are uniquely coated with an ultrathin Fe 2O 3 shell which is in situ formed during a thermal annealing treatment. The thin shell acts as an effective barrier that prevents the coalescence and ripening ofmore » Pd 2FeCo/C nanoparticles. Compared with Pd/C, Pd 2FeCo/C exhibits higher catalytic activity and long-term stability for the ORR, signifying changes in catalytic behavior due to particle sizes and strain effects. Moreover, by spontaneous decoration of Pt on the surface of Pd 2FeCo/C, the Pd 2FeCo@Pt/C core@shell structure was formed and the Pt mass activity was about 37.6 and 112.5 times higher than that on Pt/C in a 0.1 M HClO 4 and KOH solution at 0.9 V, respectively, suggesting an enhanced ORR performance after Pt decoration. More interestingly, Pd 2FeCo@Pt/C also shows a power density of ~308 mW cm -2, which is much higher than that of Pt/C (175 mW cm -2), and excellent durability in a home-made Zn–air battery.« less

  11. Apparatus for Study of Ion-Thruster Propellant Ionization

    DTIC Science & Technology

    2006-12-01

    extracted . Releasing these electrons can be done in several ways. Thermionic photo emission and field emissions are valid options. All the...50.9 80.7 106 159 208 503]; %% pressure in millitorr P2=P2/1000; %% pressure in torr Vb2 =[296 276 248 258 258 274 324]; %% voltage in volts pd2=d2...262 276 348]; %% voltage in volts pd3=d3*P3; figure(1) plot(pd1,Vb1,’bo-’,’linewidth’,2) hold on plot(pd2, Vb2 ,’rs:’,’linewidth’,2) hold on 42

  12. [Pyr1]Apelin-13(1-12) Is a Biologically Active ACE2 Metabolite of the Endogenous Cardiovascular Peptide [Pyr1]Apelin-13.

    PubMed

    Yang, Peiran; Kuc, Rhoda E; Brame, Aimée L; Dyson, Alex; Singer, Mervyn; Glen, Robert C; Cheriyan, Joseph; Wilkinson, Ian B; Davenport, Anthony P; Maguire, Janet J

    2017-01-01

    Aims: Apelin is a predicted substrate for ACE2, a novel therapeutic target. Our aim was to demonstrate the endogenous presence of the putative ACE2 product [Pyr 1 ]apelin-13 (1-12) in human cardiovascular tissues and to confirm it retains significant biological activity for the apelin receptor in vitro and in vivo . The minimum active apelin fragment was also investigated. Methods and Results: [Pyr 1 ]apelin-13 incubated with recombinant human ACE2 resulted in de novo generation of [Pyr 1 ]apelin-13 (1-12) identified by mass spectrometry. Endogenous [Pyr 1 ]apelin-13 (1-12) was detected by immunostaining in human heart and lung localized to the endothelium. Expression was undetectable in lung from patients with pulmonary arterial hypertension. In human heart [Pyr 1 ]apelin-13 (1-12) (pK i = 8.04 ± 0.06) and apelin-13(F13A) (pK i = 8.07 ± 0.24) competed with [ 125 I]apelin-13 binding with nanomolar affinity, 4-fold lower than for [Pyr 1 ]apelin-13 (pK i = 8.83 ± 0.06) whereas apelin-17 exhibited highest affinity (pK i = 9.63 ± 0.17). The rank order of potency of peptides to inhibit forskolin-stimulated cAMP was apelin-17 (pD 2 = 10.31 ± 0.28) > [Pyr 1 ]apelin-13 (pD 2 = 9.67 ± 0.04) ≥ apelin-13(F13A) (pD 2 = 9.54 ± 0.05) > [Pyr 1 ]apelin-13 (1-12) (pD 2 = 9.30 ± 0.06). The truncated peptide apelin-13(R10M) retained nanomolar potency (pD 2 = 8.70 ± 0.04) but shorter fragments exhibited low micromolar potency. In a β-arrestin recruitment assay the rank order of potency was apelin-17 (pD 2 = 10.26 ± 0.09) > [Pyr 1 ]apelin-13 (pD 2 = 8.43 ± 0.08) > apelin-13(R10M) (pD 2 = 8.26 ± 0.17) > apelin-13(F13A) (pD 2 = 7.98 ± 0.04) ≥ [Pyr 1 ]apelin-13 (1-12) (pD 2 = 7.84 ± 0.06) > shorter fragments (pD 2 < 6). [Pyr 1 ]apelin-13 (1-12) and apelin-13(F13A) contracted human saphenous vein with similar sub-nanomolar potencies and [Pyr 1 ]apelin-13 (1-12) was a potent inotrope in paced mouse right ventricle and human atria. [Pyr 1 ]apelin-13 (1-12) elicited a dose-dependent decrease in blood pressure in anesthetized rat and dose-dependent increase in forearm blood flow in human volunteers. Conclusions: We provide evidence that ACE2 cleaves [Pyr 1 ]apelin-13 to [Pyr 1 ]apelin-13 (1-12) and this cleavage product is expressed in human cardiovascular tissues. We have demonstrated biological activity of [Pyr 1 ]apelin-13 (1-12) at the human and rodent apelin receptor in vitro and in vivo . Our data show that reported enhanced ACE2 activity in cardiovascular disease should not significantly compromise the beneficial effects of apelin based therapies for example in PAH.

  13. Cardiovascular aspects of Parkinson disease.

    PubMed

    Goldstein, D S

    2006-01-01

    This chapter provides an update about cardiovascular aspects of Parkinson disease (PD), with the following topics: (1) Orthostatic hypotension (OH) as an early finding in PD; (2) neurocirculatory abnormalities in PD + OH independent of levodopa treatment; (3) cardiac and extracardiac noradrenergic denervation in PD + OH; (4) progressive loss of cardiac sympathetic innervation in PD without OH.

  14. Determination of cyanide by a highly sensitive indirect spectrophotometric method.

    PubMed

    Blanco, M; Maspoch, S

    1984-01-01

    Complexation of Pd(2+) with cyanide inhibits the extraction of the palladium complex of 5-phenylazo-8-aminoquinoline. This effect is used for the indirect spectrophotometric determination of cyanide at the mug level. Cyanide in industrial waste water and in sea-water is determined after distillation as HCN from the sample and collection in sodium hydroxide solution.

  15. Blood biomarker for Parkinson disease: peptoids

    PubMed Central

    Yazdani, Umar; Zaman, Sayed; Hynan, Linda S; Brown, L Steven; Dewey, Richard B; Karp, David; German, Dwight C

    2016-01-01

    Parkinson disease (PD) is the second most common neurodegenerative disease. Because dopaminergic neuronal loss begins years before motor symptoms appear, a biomarker for the early identification of the disease is critical for the study of putative neuroprotective therapies. Brain imaging of the nigrostriatal dopamine system has been used as a biomarker for early disease along with cerebrospinal fluid analysis of α-synuclein, but a less costly and relatively non-invasive biomarker would be optimal. We sought to identify an antibody biomarker in the blood of PD patients using a combinatorial peptoid library approach. We examined serum samples from 75 PD patients, 25 de novo PD patients, and 104 normal control subjects in the NINDS Parkinson’s Disease Biomarker Program. We identified a peptoid, PD2, which binds significantly higher levels of IgG3 antibody in PD versus control subjects (P<0.0001) and is 68% accurate in identifying PD. The PD2 peptoid is 84% accurate in identifying de novo PD. Also, IgG3 levels are significantly higher in PD versus control serum (P<0.001). Finally, PD2 levels are positively correlated with the United Parkinson’s Disease Rating Scale score (r=0.457, P<0001), a marker of disease severity. The PD2 peptoid may be useful for the early-stage identification of PD, and serve as an indicator of disease severity. Additional studies are needed to validate this PD biomarker. PMID:27812535

  16. 49 CFR 387.323 - Electronic filing of surety bonds, trust fund agreements, certificates of insurance and...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Start field End field Record type 1 Numeric 1=Filing2=Cancellation B 1 1 Insurer number 8 Text FMCSA... Filing type 1 Numeric 1 = BI&PD2 = Cargo 3 = Bond 4 = Trust Fund B 10 10 FMCSA docket number 8 Text FMCSA... 264 265 Insured zip code 9 Numeric (Do not include dash if using 9 digit code) B 266 274 Insured...

  17. 49 CFR 387.323 - Electronic filing of surety bonds, trust fund agreements, certificates of insurance and...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Start field End field Record type 1 Numeric 1=Filing2=Cancellation B 1 1 Insurer number 8 Text FMCSA... Filing type 1 Numeric 1 = BI&PD2 = Cargo 3 = Bond 4 = Trust Fund B 10 10 FMCSA docket number 8 Text FMCSA... 264 265 Insured zip code 9 Numeric (Do not include dash if using 9 digit code) B 266 274 Insured...

  18. Quantitative Structure-Activity Relationships for Organophosphate Enzyme Inhibition (Briefing Charts)

    DTIC Science & Technology

    2011-09-22

    OPs) are a group of pesticides that inhibit enzymes such as acetylcholinesterase. Numerous OP structural variants exist and toxicity data can be...and human toxicity studies especially for OPs lacking experimental data. 15. SUBJECT TERMS QSAR Organophosphates...structure and mechanism of toxicity c) Linking QSAR and OP PBPK/PD 2. Methods a) Physiochemical Descriptors b) Regression Techniques 3. Results a

  19. Enzymatic Recovery of Elemental Palladium by Using Sulfate-Reducing Bacteria

    PubMed Central

    Lloyd, Jon R.; Yong, Ping; Macaskie, Lynne E.

    1998-01-01

    Worldwide usage of platinum group metals is increasing, prompting new recovery technologies. Resting cells of Desulfovibrio desulfuricans reduced soluble Pd2+ to elemental, cell-bound Pd0 supported by pyruvate, formate, or H2 as the electron donor without biochemical cofactors. Pd reduction was O2 insensitive, opening the way for recycling and recovery of Pd under oxic conditions. PMID:9797331

  20. Particle Size Control for PIV Seeding Using Dry Ice

    DTIC Science & Technology

    2010-03-01

    in flight actually being carried out, the observations, drawings and notes of Leonardo da Vinci showed an analytical process to develop a way for...theoretical particle response: dvp dt = −C(vp − U) C = 18µ ρpd2p 86 87 Bibliography 1. Linscott, R. N. and Da Vinci , L., The Notebooks of Leonardo Da Vinci

  1. Relaxant effect of Ent-7α-hydroxytrachyloban-18-oic acid, a trachylobane diterpene from Xylopia langsdorfiana A. St-Hil. & Tul., on tracheal smooth muscle.

    PubMed

    Martins, Italo R R; Dos Santos, Rosimeire F; de C Correia, Ana C; de Oliveira, Gislaine A; Macêdo, Cibério L; de S Monteiro, Fabio; Dos Santos, Paula F; de A Cavalcante, Fabiana; Tavares, Josean F; da Silva, Bagnólia A

    2013-01-01

    Ent-7α-hydroxytrachyloban-18-oic acid, a trachylobane diterpene from Xylopia langsdorfiana, has previously been shown to relax the guinea-pig trachea in a concentration-dependent manner. In this study we aimed to elucidate the mechanisms underlying this action and so contribute to the discovery of natural products with therapeutic potential. A possible interaction between diterpene and the Ca(2+)-calmodulin complex was eliminated as chlorpromazine (10(-6) M), a calmodulin inhibitor, did not significantly alter the diterpene-induced relaxation (pD2 = 4.38 ± 0.07 and 4.25 ± 0.07; mean ± S.E.M., n=5). Trachylobane-318 showed a higher relaxant potency when the trachea was contracted by 18 mM KCl than it did with 60 mM KCl (pD2 = 4.90 ± 0.25 and 3.88 ± 0.01, n=5), suggesting the possible activation of K(+) channels. This was confirmed, as in the presence of 10 mM TEA(+) (a non-selective K(+) channel blocker), diterpene relaxation potency was significantly reduced (pD2 = 4.38 ± 0.07 to 4.01 ± 0.06, n=5). Furthermore, K(+) channel subtypes KATP, KV, SKCa and BKCa seem to be modulated positively by trachylobane-318 (pD2 = 3.91 ± 0.003, 4.00 ± 0.06, 3.45 ± 0.14 and 3.80 ± 0.05, n=5) but not the Kir subtype channel (pD2 = 4.15 ± 0.10, n=5). Cyclic nucleotides were not involved as the relaxation due to aminophylline (pD2 = 4.27 ± 0.09, n=5) was not altered in the presence of 3 × 10(-5) M trachylobane-318 (pD2 = 4.46 ± 0.08, n=5). Thus, at a functional level, trachylobane-318 seems to relax the guinea-pig trachea by positive modulation of K(+) channels, particularly the KATP, KV, SKCa and BKCa subtypes.

  2. Relaxant effect of Ent‑7α‑hydroxytrachyloban‑18-oic acid, a trachylobane diterpene from Xylopia langsdorfiana A. St-Hil. & Tul., on tracheal smooth muscle

    PubMed Central

    Martins, Italo R. R.; dos Santos, Rosimeire F.; Correia, Ana C. de C.; de Oliveira, Gislaine A.; Macêdo, Cibério L.; Monteiro, Fabio de S.; dos Santos, Paula F.; Cavalcante, Fabiana de A.; Tavares, Josean F.; da Silva, Bagnólia A.

    2013-01-01

    Ent-7α-hydroxytrachyloban-18-oic acid, a trachylobane diterpene from Xylopia langsdorfiana, has previously been shown to relax the guinea-pig trachea in a concentration-dependent manner. In this study we aimed to elucidate the mechanisms underlying this action and so contribute to the discovery of natural products with therapeutic potential. A possible interaction between diterpene and the Ca2+-calmodulin complex was eliminated as chlorpromazine (10-6 M), a calmodulin inhibitor, did not significantly alter the diterpene-induced relaxation (pD2 = 4.38 ± 0.07 and 4.25 ± 0.07; mean ± S.E.M., n=5). Trachylobane-318 showed a higher relaxant potency when the trachea was contracted by 18 mM KCl than it did with 60 mM KCl (pD2 = 4.90 ± 0.25 and 3.88 ± 0.01, n=5), suggesting the possible activation of K+ channels. This was confirmed, as in the presence of 10 mM TEA+ (a non-selective K+ channel blocker), diterpene relaxation potency was significantly reduced (pD2 = 4.38 ± 0.07 to 4.01 ± 0.06, n=5). Furthermore, K+ channel subtypes KATP, KV, SKCa and BKCa seem to be modulated positively by trachylobane-318 (pD2 = 3.91 ± 0.003, 4.00 ± 0.06, 3.45 ± 0.14 and 3.80 ± 0.05, n=5) but not the Kir subtype channel (pD2 = 4.15 ± 0.10, n=5). Cyclic nucleotides were not involved as the relaxation due to aminophylline (pD2 = 4.27 ± 0.09, n=5) was not altered in the presence of 3 × 10-5 M trachylobane-318 (pD2 = 4.46 ± 0.08, n=5). Thus, at a functional level, trachylobane-318 seems to relax the guinea-pig trachea by positive modulation of K+ channels, particularly the KATP, KV, SKCa and BKCa subtypes. PMID:23832615

  3. Synthesis, Crystal Chemistry, and Physical Properties of Ternary Intermetallic Compounds An2T2X( An=Pu, Am; X=ln, Sn; T=Co, Ir, Ni, Pd, Pt, Rh)

    NASA Astrophysics Data System (ADS)

    Pereira, L. C. J.; Wastin, F.; Winand, J. M.; Kanellakopoulos, B.; Rebizant, J.; Spirlet, J. C.; Almeida, M.

    1997-11-01

    The synthesis, structural, and physical characterization of nine new ternary intermetallic compounds belonging to the isostructural An2T2Xfamily with the transuranium Pu and Am elements, namely, Pu 2Ni 2In, Pu 2Pd 2In, Pu 2Pt 2In, Pu 2Rh 2In, Pu 2Ni 2Sn, Pu 2Pd 2Sn, Pu 2Pt 2Sn, Am 2Ni 2Sn, and Am 2Pd 2Sn, are reported. From these compounds only Pu 2Rh 2In, Am 2Ni 2Sn, and Am 2Pd 2Sn melt incongruently. All of these compounds crystallize in a tetragonal U 3Si 2-type structure, with the space group P4/ mbm, ( Z=2) as most of the U and Np 2-2-1 compounds already found. In this structure, Anatoms occupy the 4 h( x1, x1+0.5, 0.5), Tthe 4 g( x2, x2+0.5, 0), and Xthe 2 a(0, 0, 0) positions. The average values of x1and x2are, respectively, 0.17 and 0.37. Single-crystal X-ray data were refined to R/ RW=0.045/0.066, 0.043/0.072, 0.066/0.080, 0.070/0.098, 0.029/0.048, 0.055/0.080, 0.073/0.096, 0.048/0.086, 0.048/0.065 for Pu 2Ni 2In, Pu 2Pd 2In, Pu 2Pt 2In, Pu 2Rh 2In, Pu 2Ni 2Sn, Pu 2Pd 2Sn, Pu 2Pt 2Sn, Am 2Ni 2Sn, and Am 2Pd 2Sn, respectively, for seven variables. The variation of the lattice parameters and the range of stability of the 2-2-1 phase are discussed in terms of the substitution of different An(actinide), T(transition metal), and X( p-electron) elements in their crystal structure. The possible role of spin fluctuations in the low-temperature behavior of the Pu samples is indicated by magnetic and electrical resistivity measurements.

  4. Development of the ACTH and corticosterone response to acute hypoxia in the neonatal rat

    PubMed Central

    Bruder, Eric D.; Taylor, Jennifer K.; Kamer, Kimberli J.; Raff, Hershel

    2008-01-01

    Acute episodes of severe hypoxia are among the most common stressors in neonates. An understanding of the development of the physiological response to acute hypoxia will help improve clinical interventions. The present study measured ACTH and corticosterone responses to acute, severe hypoxia (8% inspired O2 for 4 h) in neonatal rats at postnatal days (PD) 2, 5, and 8. Expression of specific hypothalamic, anterior pituitary, and adrenocortical mRNAs was assessed by real-time PCR, and expression of specific proteins in isolated adrenal mitochondria from adrenal zona fascisulata/reticularis was assessed by immunoblot analyses. Oxygen saturation, heart rate, and body temperature were also measured. Exposure to 8% O2 for as little as 1 h elicited an increase in plasma corticosterone in all age groups studied, with PD2 pups showing the greatest response (∼3 times greater than PD8 pups). Interestingly, the ACTH response to hypoxia was absent in PD2 pups, while plasma ACTH nearly tripled in PD8 pups. Analysis of adrenal mRNA expression revealed a hypoxia-induced increase in Ldlr mRNA at PD2, while both Ldlr and Star mRNA were increased at PD8. Acute hypoxia decreased arterial O2 saturation (SPo2) to ∼80% and also decreased body temperature by 5–6°C. The hypoxic thermal response may contribute to the ACTH and corticosterone response to decreases in oxygen. The present data describe a developmentally regulated, differential corticosterone response to acute hypoxia, shifting from ACTH independence in early life (PD2) to ACTH dependence less than 1 wk later (PD8). PMID:18703410

  5. Montreal Cognitive Assessment 5-minute protocol is a brief, valid, reliable, and feasible cognitive screen for telephone administration.

    PubMed

    Wong, Adrian; Nyenhuis, David; Black, Sandra E; Law, Lorraine S N; Lo, Eugene S K; Kwan, Pauline W L; Au, Lisa; Chan, Anne Y Y; Wong, Lawrence K S; Nasreddine, Ziad; Mok, Vincent

    2015-04-01

    The National Institute of Neurological Disorders and Stroke-Canadian Stroke Network Vascular Cognitive Impairment Harmonization working group proposed a brief cognitive protocol for screening of vascular cognitive impairment. We investigated the validity, reliability, and feasibility of the Montreal Cognitive Assessment 5-minute protocol (MoCA 5-minute protocol) administered over the telephone. Four items examining attention, verbal learning and memory, executive functions/language, and orientation were extracted from the MoCA to form the MoCA 5-minute protocol. One hundred four patients with stroke or transient ischemic attack, including 53 with normal cognition (Clinical Dementia Rating, 0) and 51 with cognitive impairment (Clinical Dementia Rating, 0.5 or 1), were administered the MoCA in clinic and a month later, the MoCA 5-minute protocol over the telephone. Administration of the MoCA 5-minute protocol took 5 minutes over the telephone. Total score of the MoCA 5-minute protocol correlated negatively with age (r=-0.36; P<0.001) and positively with years of education (r=0.41; P<0.001) but not with sex (ρ=0.03; P=0.773). Total scores of the MoCA and MoCA 5-minute protocol were highly correlated (r=0.87; P<0.001). The MoCA 5-minute protocol performed equally well as the MoCA in differentiating patients with cognitive impairment from those without (areas under receiver operating characteristics curve for MoCA 5-minute protocol, 0.78; MoCA=0.74; P>0.05 for difference; Cohen d for group difference, 0.80-1.13). It differentiated cognitively impaired patients with executive domain impairment from those without (areas under receiver operating characteristics curve, 0.89; P<0.001; Cohen d=1.7 for group difference). Thirty-day test-retest reliability was excellent (intraclass correlation coefficient, 0.89). The MoCA 5-minute protocol is a free, valid, and reliable cognitive screen for stroke and transient ischemic attack. It is brief and highly feasible for telephone

  6. Structural, spectral and birefringence studies of semiorganic nonlinear optical single crystal: Calcium5-sulfosalicylate

    NASA Astrophysics Data System (ADS)

    Shalini, D.; Kalainathan, S.; Ambika, V. Revathi; Hema, N.; Jayalakshmi, D.

    2017-11-01

    Semi-organic nonlinear optical crystal Calcium5-Sulfosalicylate (CA5SS) was grown by slow evaporation solution growth technique. The cell parameters and molecular structure of the grown crystal were studied by single crystal x-ray diffraction analysis. The presence of various functional groups of the grown crystal was confirmed using Fourier transform infrared (FT-IR), Fourier transform Raman (FT-Raman) analysis. UV-Visible spectrum shows that CA5SS crystals have high transmittance in the range of 330-900 nm. The refractive index, birefringence and transient photoluminescence properties of the grown crystal were analyzed. The frequency doubling of the grown crystal (CA5SS) were studied and compared with that of KDP.

  7. A near-infrared fluorescent probe for rapid detection of carbon monoxide in living cells.

    PubMed

    Yan, Liqiang; Nan, Ding; Lin, Cheng; Wan, Yi; Pan, Qiang; Qi, Zhengjian

    2018-09-05

    A near-infrared (NIR) and colorimetric fluorescent probe system was developed for Carbon Monoxide (CO) via a Pd 0 -mediated Tsuji-Trost reaction. In this probe, phenoxide anion formation (DPCO - ) was acted as the signal unit and an allyl carbonate group was used as the recognition unit. This non-fluorescent probe molecule can release the relevant fluorophore after conversion of Pd 2+ to Pd 0 by CO. The probe system including probe 1 and Pd 2+ can be used for "naked-eye" detection of CO, and exhibited high selectivity to CO over various other sensing objects. More importantly, the probe system has great potential for fluorescence imaging of intracellular CO in living cells. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Evidence of mixed valence states in U M2Al 3 ( M = Ni, Pd) studied by X-ray photoemission spectroscopy

    NASA Astrophysics Data System (ADS)

    Fujimori, Shin-ichi; Saito, Yasuharu; Sato, Noriaki; Komatsubara, Takemi; Suzuki, Shoji; Sato, Shigeru; Ishii, Takehiko

    1998-01-01

    We have measured the XPS valence band and core-level spectra of U M2Al 3 ( M = Ni and Pd). The results are compared with those of reference materials, dilute alloy U 0.1La 0.9Pd 2Al 3 and itinerant 5 f compound URh 3. The similarity of the core-level spectra between UPd 2Al 3 and U 0.1La 0.9Pd 2Al 3 suggests that their core-level spectra are governed by the interaction between U 5 f and ligand states of neighboring palladium and aluminum sites, with negligible contributions from neighboring uranium states. A complex satellite structure, observed in the core-level spectra of U M2Al 3, suggests that the uranium atoms are in the strong mixed valence states with 5 f2(U 4+) and 5 f3(U 3+).

  9. The Pressure Dependence of Structural, Electronic, Mechanical, Vibrational, and Thermodynamic Properties of Palladium-Based Heusler Alloys

    NASA Astrophysics Data System (ADS)

    Çoban, Cansu

    2017-08-01

    The pressure dependent behaviour of the structural, electronic, mechanical, vibrational, and thermodynamic properties of Pd2TiX (X=Ga, In) Heusler alloys was investigated by ab initio calculations. The lattice constant, the bulk modulus and its first pressure derivative, the electronic band structure and the density of states (DOS), mechanical properties such as elastic constants, anisotropy factor, Young's modulus, etc., the phonon dispersion curves and phonon DOS, entropy, heat capacity, and free energy were obtained under pressure. It was determined that the calculated lattice parameters are in good agreement with the literature, the elastic constants obey the stability criterion, and the phonon dispersion curves have no negative frequency which shows that the compounds are stable. The band structures at 0, 50, and 70 GPa showed valence instability at the L point which explains the superconductivity in Pd2TiX (X=Ga, In).

  10. Solution synthesis of metal silicide nanoparticles.

    PubMed

    McEnaney, Joshua M; Schaak, Raymond E

    2015-02-02

    Transition-metal silicides are part of an important family of intermetallic compounds, but the high-temperature reactions that are generally required to synthesize them preclude the formation of colloidal nanoparticles. Here, we show that palladium, copper, and nickel nanoparticles react with monophenylsilane in trioctylamine and squalane at 375 °C to form colloidal Pd(2)Si, Cu(3)Si, and Ni(2)Si nanoparticles, respectively. These metal silicide nanoparticles were screened as electrocatalysts for the hydrogen evolution reaction, and Pd(2)Si and Ni(2)Si were identified as active catalysts that require overpotentials of -192 and -243 mV, respectively, to produce cathodic current densities of -10 mA cm(-2).

  11. Simultaneous nanocalorimetry and fast XRD measurements to study the silicide formation in Pd/a-Si bilayers.

    PubMed

    Molina-Ruiz, Manel; Ferrando-Villalba, Pablo; Rodríguez-Tinoco, Cristian; Garcia, Gemma; Rodríguez-Viejo, Javier; Peral, Inma; Lopeandía, Aitor F

    2015-05-01

    The use of a membrane-based chip nanocalorimeter in a powder diffraction beamline is described. Simultaneous wide-angle X-ray scattering and scanning nanocalorimetric measurements are performed on a thin-film stack of palladium/amorphous silicon (Pd/a-Si) at heating rates from 0.1 to 10 K s(-1). The nanocalorimeter works under a power-compensation scheme previously developed by the authors. Kinetic and structural information of the consumed and created phases can be obtained from the combined techniques. The formation of Pd2Si produces a broad calorimetric peak that contains overlapping individual processes. It is shown that Pd consumption precedes the formation of the crystalline Pd2Si phase and that the crystallite size depends on the heating rate of the experiment.

  12. N-benzoylimido complexes of palladium. Synthesis, structural characterisation and structure-reactivity relationship.

    PubMed

    Besenyei, Gábor; Párkányi, László; Szalontai, Gábor; Holly, Sándor; Pápai, Imre; Keresztury, Gábor; Nagy, Andrea

    2004-07-07

    Benzoyl azides, ArC(O)N3, 2, (Ar = phenyl or substituted phenyl), react with [Pd2Cl2(dppm)2], 1, [dppm = bis(diphenylphosphino)methane] with the formation of novel [Pd2Cl2(mu-NC(O)Ar)(dppm)2], 3, benzoylnitrene complexes that were structurally characterised by multinuclear magnetic resonance and IR spectroscopy and, in several instances, by single crystal X-ray diffraction. As shown by crystallographic studies, the C2P4Pd2 rings adopt extended twist-boat conformations with methylene groups bending towards the bridging benzoylimido moieties. X-ray diffraction studies have revealed the chiral nature of the imido complexes, the chiral element being the propeller-like C2P4Pd2 ring. Structural data accumulated on complexes 3 such as short C-N distances (1.32 A), elongated C=O bonds (1.30 A) as well as the outstandingly high barrier to internal rotation around the N-C(O) linkage (88.3 kJ mol(-1)) are in line with extensive ppi-ppi interaction between the bridging nitrogen and the carbonyl carbon atoms. Theoretical calculations indicate an electron shift from the dimer towards the apical nitrogen atom, which, in turn, facilitates the donation of electrons towards the carbonyl moiety. To elucidate the structure-reactivity relationship of benzoyl azides towards 1, crystallographic and solution IR spectroscopic studies were carried out on a series of para-substituted benzoyl azides. The reaction obeys the Hammett equation. The large positive value of the reaction constant indicates that the azides act as electrophiles in the reaction studied. The enhanced reactivity of 2-nitrobenzoyl azide has been attributed to a decreased conjugation of the phenyl and carbonyl moieties in this reagent.

  13. Pawcatuck and Woonasquatucket River Basins and Narragansett Bay Local Drainage Area. Main Report.

    DTIC Science & Technology

    1981-10-01

    building and housing codes are recommended. Flood warning systems, urban renewal, tax incentives, and public open space acquisition will also help...RIVER GROUP WATERSHEDLD LOCAL DRAINAGE PD, WOONASQUATUCKET - MOSI4ASSUCK - PROVIDENCE RIVERS SUB-BASIN PD2 BLACKSTONE RIVER SUB-BASIN orPD 3 TENMiLE...of the Taunton River Basin in Massachusetts, 1979 PNB Water Supply Study, January 1979 Big River Reservoir Project, July 1981 Blackstone River

  14. A Parametric Analysis of Structured and Unstructured Q-Sort Data.

    DTIC Science & Technology

    1981-06-09

    this consideration, a hypothesis intermediate between H0 and the general alternative of the form H’: Odk m 0, d = DI p....,D 2 and k=i, (where wjl -, the...judging-perceiving (J-P). The scores E-I and J-P, with the intercept, made up the subject design matrix. 56 (7) Sherlock collected Q-sorts from 80

  15. Purification, characterization, and biological activity of a substance P-related peptide from the gut of the Australian lungfish, Neoceratodus forsteri.

    PubMed

    Liu, Lu; Conlon, J Michael; Joss, Jean M P; Burcher, Elizabeth

    2002-01-01

    A peptide with mammalian substance P (SP)-like immunoreactivity was isolated from an extract of the spiral intestine of the Australian lungfish, Neoceratodus forsteri. The primary structure of this peptide was established as Lys-Pro-Arg-Pro-Asp-Glu-Phe-Tyr-Gly-Leu-Met . NH2, showing 64% identity with mammalian SP. In isolated preparations of lungfish foregut circular muscle, lungfish SP produced a slow, long-lasting tonic contraction, with a pD2 value of 8.19. Lungfish midgut circular muscle preparations responded to lungfish SP rapidly and in a more complex manner. There was an increase in the frequency of spontaneous activity (pD2 = 8.76), associated with diminished amplitude of the spontaneous contractions (pD2 = 9.24), also coupled in some preparations with a tonic contraction (pD2 = 8.43). The response patterns of foregut and midgut circular muscle to acetylcholine (ACh) were very similar to those seen to lungfish SP. Lungfish SP and ACh, however, had very weak effects on both foregut and midgut longitudinal muscle. These data demonstrate that lungfish SP may be a physiologically important regulator of gastrointestinal motility in Neoceratodus. This study further confirmed that the structures of SP-related peptides have been strongly conserved under the pressure of vertebrate evolution, particularly in preserving the functionally important sequence, Phe-Xaa-Gly-Leu-Met . amide, at the C-terminus. The sequence of lungfish SP is identical to that of bufokinin, a SP-related peptide previously isolated from the intestine of the cane toad, Bufo marinus, supporting the hypothesis that lungfishes and amphibians share a common ancestor.

  16. Large Scale Single Nucleotide Polymorphism Study of PD Susceptibility

    DTIC Science & Technology

    2005-03-01

    identification of eight genetic loci in the familial PD, the results of intensive investigations of polymorphisms in dozens of genes related to sporadic, late...1) investigate the association between classical, sporadic PD and 2386 SNPs in 23 genes implicated in the pathogenesis of PD; (2) construct...addition, experiences derived from this study may be applied in other complex disorders for the identification of susceptibility genes , as well as in genome

  17. Large Scale Single Nucleotide Polymorphism Study of PD Susceptibility

    DTIC Science & Technology

    2006-03-01

    familial PD, the results of intensive investigations of polymorphisms in dozens of genes related to sporadic, late onset, typical PD have not shown...association between classical, sporadic PD and 2386 SNPs in 23 genes implicated in the pathogenesis of PD; (2) construct haplotypes based on the SNP...derived from this study may be applied in other complex disorders for the identification of susceptibility genes , as well as in genome-wide SNP

  18. Acute resistance exercise reduces blood pressure and vascular reactivity, and increases endothelium-dependent relaxation in spontaneously hypertensive rats.

    PubMed

    Faria, Thaís de Oliveira; Targueta, Gabriel Pelegrineti; Angeli, Jhuli Keli; Almeida, Edna Aparecida Silveira; Stefanon, Ivanita; Vassallo, Dalton Valentim; Lizardo, Juliana Hott de Fúcio

    2010-09-01

    The aim of the present study was to assess the effects of acute dynamic resistance exercise on resting blood pressure (BP) and on endothelial function of vascular bed of spontaneously hypertensive rats. Hemodynamic measurements were performed before and after acute dynamic resistance exercise in conscious animals. After exercise, the tail artery was cannulated for mean perfusion pressure with constant flow measurement and for performing concentration-response curves to acetylcholine (ACh) and sodium nitroprusside (SNP) and dose-response curves to phenylephrine (PHE). PHE protocol was also repeated with damaged endothelium and after L-NAME and indomethacin perfusion on the tail. The maximal response (E(max)) and sensitivity (pD(2)) were evaluated to these drugs. Exercise reduced resting systolic and diastolic BP (Delta -79 +/- 1.8; -23 +/- 2.3 mmHg, respectively; P < 0.05). ACh-induced relaxation increased in the exercise group (pD(2) = 9.8 +/- 0.06, P < 0.05) when compared with control rats (pD(2) = 8.7 +/- 0.1). The E(max) to PHE with intact endothelium decreased following exercise condition (439 +/- 18 mmHg, P < 0.05) when compared with control rats (276 +/- 22 mmHg). This response was abolished after L-NAME and indomethacin administration. After damage of the endothelium, PHE responses were not significantly different between the groups; however, E(max) and pD(2) increased when compared with responses obtained with intact endothelium. The results demonstrated that acute dynamic resistance exercise decreased resting BP and reactivity to PHE and increased endothelium-dependent relaxation. Nitric oxide and vasodilators prostanoids appear to be involved in post-exercise endothelial and pressor responses.

  19. 49 CFR 387.323 - Electronic filing of surety bonds, trust fund agreements, certificates of insurance and...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Description RequiredF=filing C=cancel B=both Start field End field Record type 1 Numeric 1=Filing 2=Cancellation B 1 1 Insurer number 8 Text FMCSA Assigned Insurer Number (Home Office) With Suffix (Issuing Office), If Different, e.g. 12345-01 B 2 9 Filing type 1 Numeric 1 = BI&PD 2 = Cargo 3 = Bond 4 = Trust...

  20. 49 CFR 387.323 - Electronic filing of surety bonds, trust fund agreements, certificates of insurance and...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Description RequiredF=filing C=cancel B=both Start field End field Record type 1 Numeric 1=Filing 2=Cancellation B 1 1 Insurer number 8 Text FMCSA Assigned Insurer Number (Home Office) With Suffix (Issuing Office), If Different, e.g. 12345-01 B 2 9 Filing type 1 Numeric 1 = BI&PD 2 = Cargo 3 = Bond 4 = Trust...

  1. Calix[3]carbazole: A C3-symmetrical receptor for barium ion

    NASA Astrophysics Data System (ADS)

    Yang, Zhaozheng; Tian, Zhangmin; Yang, Peng; Deng, Tuo; Li, Gang; Zhou, Xue; Chen, Yan; Zhao, Liang; Shen, Hongyan

    2017-03-01

    The binding ability of calix[3]carbazole (1) to metal ions has been investigated. It is found that 1 could serve as a non crown ether based, C3-symmetrical receptor for Ba2 + via the marriage of cation-π and cation-dipole interactions. FID assay further illustrates that 1 could selectively interact with Ba2 + over Pd2 +. A possible binding mechanism for [1-Ba2 +] complex is proposed.

  2. A novel high-strength and highly corrosive biodegradable Fe-Pd alloy: Structural, mechanical and in vitro corrosion and cytotoxicity study.

    PubMed

    Čapek, Jaroslav; Msallamová, Šárka; Jablonská, Eva; Lipov, Jan; Vojtěch, Dalibor

    2017-10-01

    Recently, iron-based materials have been considered as candidates for the fabrication of biodegradable load-bearing implants. Alloying with palladium has been found to be a suitable approach to enhance the insufficient corrosion rate of iron-based alloys. In this work, we have extensively compared the microstructure, the mechanical and corrosion properties, and the cytotoxicity of an FePd2 (wt%) alloy prepared by three different routes - casting, mechanical alloying and spark plasma sintering (SPS), and mechanical alloying and the space holder technique (SHT). The properties of the FePd2 (wt%) were compared with pure Fe prepared in the same processes. The preparation route significantly influenced the material properties. Materials prepared by SPS possessed the highest values of mechanical properties (CYS~750-850MPa) and higher corrosion rates than the casted materials. Materials prepared by SHT contained approximately 60% porosity; therefore, their mechanical properties reached the lowest values, and they had the highest corrosion rates, approximately 0.7-1.2mm/a. Highly porous FePd2 was tested in vitro according to the ISO 10993-5 standard using L929 cells, and two-fold diluted extracts showed acceptable cytocompatibility. In general, alloying with Pd enhanced both mechanical properties and corrosion rates and did not decrease the cytocompatibility of the studied materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Palladium silicide formation under the influence of nitrogen and oxygen impurities

    NASA Technical Reports Server (NTRS)

    Ho, K. T.; Lien, C.-D.; Nicolet, M.-A.

    1985-01-01

    The effect of impurities on the growth of the Pd2Si layer upon thermal annealing of a Pd film on 100 line-type and amorphous Si substrates is investigated. Nitrogen and oxygen impurities are introduced into either Pd or Si which are subsequently annealed to form Pd2Si. The complementary techniques of Rutherford backscattering spectrometry, and N-15(p, alpha)C-12 or O-18(p, alpha)N-15 nuclear reaction, are used to investigate the behavior of nitrogen or oxygen and the alterations each creates during silicide formation. Both nitrogen and oxygen retard the silicide growth rate if initially present in Si. When they are initially in Pd, there is no significant retardation; instead, an interesting snow-plowing effect of N or O by the reaction interface of Pd2Si is observed. By using N implanted into Si as a marker, Pd and Si appear to trade roles as the moving species when the silicide front reaches the nitrogen-rich region.

  4. Catalytic oxidation of low-concentration CO at ambient temperature over supported Pd-Cu catalysts.

    PubMed

    Wang, Fagen; Zhang, Haojie; He, Dannong

    2014-01-01

    The CO catalytic oxidation at ambient temperature and high space velocity was studied over the Pd-Cu/MOx (MOx = TiO2 and AI203) catalysts. The higher Brunauer-Emmett-Teller area surface of the A1203 support facilitates the dispersion of Pd2+ species, and the presence of Cu2Cl(OH)3 accelerates the re-oxidation of Pd0 to Pd2+ over the Pd-Cu/Al203 catalyst, which contributed to better performance of CO catalytic oxidation. The poorer activity of the Pd-Cu/TiO2 catalyst was attributed to the lower dispersion of Pd2+ species because of the less surface area and the non-formation of Cu2CI(OH)3 species. The presence of saturated moisture showed a negative effect on CO conversion over the two catalysts. This might be because of the competitive adsorption, the formation of carbonate species and the transformation of Cu2CI(OH)3 to inactive CuCI over the Pd-Cu/AI2O3 catalyst, which facilitates the aggregation of PdO species over the Pd-Cu/TiO2 catalyst under the moisture condition.

  5. Regional differences of the contractile responses to acetylcholine and neurokinin A in rabbit airway: heterogeneous distribution of the metabolic enzymes.

    PubMed

    Goroumaru-Shinkai, M; Yamamoto, R; Funayama, N; Takayanagi, I

    1992-11-01

    1. Experiments were designed to determine whether differences exist in the sensitivity to muscarinic and tachykinin agonists in rabbit airways. 2. The rank order of sensitivity (pD2 value) to acetylcholine was: trachea > proximal bronchus > distal bronchus, whereas no regional difference was observed in the sensitivity to carbamylcholine which is resistant to acetylcholinesterase. 3. Acetylcholinesterase activity was greater in the distal than in the proximal airway. 4. In the absence of the peptidase inhibitor, phosphoramidon, the pD2 values of neurokinin A (NKA) and substance P (SP) in trachea were significantly greater than that in bronchus, whereas no regional difference was observed in the NK1 selective agonist, substance P methyl ester (SPOMe). 5. Application of phosphoramidon (10 microM) to avoid peptide degradation abolished the regional difference of the pD2 values of SP. 6. In conclusion, regional differences in sensitivities to acetylcholine and NKA in the rabbit airway were suggested to be due to distribution to the metabolic enzymes of these drugs.

  6. 29 CFR 782.8 - Special classes of carriers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., and ice) to railroad, docks, etc., for use of trains and steamships is not such transportation as is... cases cited in § 782.7(c), and see Mitchell v. Independent Ice Co., 294 F. 2d 186 (C.A. 5), certiorari..., driver's helpers, loaders, and mechanics employed by companies engaged in such activities are covered by...

  7. 29 CFR 782.8 - Special classes of carriers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., and ice) to railroad, docks, etc., for use of trains and steamships is not such transportation as is... cases cited in § 782.7(c), and see Mitchell v. Independent Ice Co., 294 F. 2d 186 (C.A. 5), certiorari..., driver's helpers, loaders, and mechanics employed by companies engaged in such activities are covered by...

  8. 29 CFR 782.8 - Special classes of carriers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., and ice) to railroad, docks, etc., for use of trains and steamships is not such transportation as is... cases cited in § 782.7(c), and see Mitchell v. Independent Ice Co., 294 F. 2d 186 (C.A. 5), certiorari..., driver's helpers, loaders, and mechanics employed by companies engaged in such activities are covered by...

  9. Effect of high hydrostatic pressure processing on the background microbial loads and quality of cantaloupe puree

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to investigate and evaluate the effects of high hydrostatic pressure (HHP) applied to cantaloupe puree (CP) on microbial loads and product quality during storage for 10 days at 4 degrees C. Freshly prepared, double sealed and double bagged CP (ca. 5 g) was pressure tr...

  10. 75 FR 4587 - Division of Federal Employees' Compensation; Proposed Extension of the Approval of Information...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-28

    ..., CA-5b, CA-1031, CA1074, Letter of Compensation Due at Death and Letter of Student/Dependency). A copy... show dependency under the Federal Employees' Compensation Act. There are six forms in this information... disability benefits or a scheduled award. The letter of ``Student/Dependency'' is used to obtain information...

  11. TRANSFORMATION OF PB(II FROM CERRUSITE TO CHLOROPYROMORPHITE IN THE PRESENCE OF HYDROXYAPATITE UNDER VARYING CONDITIONS OF PH

    EPA Science Inventory

    The soluble Pb concentration and formation of chloropyromorphite [Pb5(PO4)3Cl] were monitored during the reaction of cerrusite (PbCO3), a highly bioavailable soil Pb species, and hydroxyapatite [Ca5(PO4)3OH] at various P/Pb molar ratios under constant and dynamic pH conditions. ...

  12. Sporulation capacity of Phytophthora ramorum on northern red oak and chestnut oak

    USDA-ARS?s Scientific Manuscript database

    Branches from six 2 to 3-year old northern red and chestnut oak seedlings were dip-inoculated with ca. 5,000 sporangia per milliliter of Phytophthora ramorum isolate Pr-6 and incubated at 100 percent relative humidity in dew chambers for 6 days. Three plants were then used to assess sporangia produ...

  13. Fate of Escherichia coli O157:H7 in mechanically tenderized beef prime rib following searing, cooking and holding under commercial conditions

    USDA-ARS?s Scientific Manuscript database

    We evaluated the effect of commercial times/temperatures for searing, cooking, and holding for the destruction of Escherichia coli O157:H7 (ECOH) from mechanically tenderized prime rib. Boneless beef ribeye was inoculated on the fat side with ca. 5.7 log CFU/g of a five-strain cocktail of ECOH and t...

  14. 29 CFR 779.324 - Recognition “in.”

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... emphasized in the debates in Congress that while the views of an industry are significant and material in... Tire Co., 383 U.S. 190; Mitchell v. City Ice Co., 273 F. 2d 560 (CA-5); Durkin v. Casa Baldrich, Inc., 111 F. Supp. 71 (DCPR) affirmed 214 F. 2d 703 (CA-1); see also Aetna Finance Co. v. Mitchell, 247 F...

  15. 29 CFR 779.324 - Recognition “in.”

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... emphasized in the debates in Congress that while the views of an industry are significant and material in... Tire Co., 383 U.S. 190; Mitchell v. City Ice Co., 273 F. 2d 560 (CA-5); Durkin v. Casa Baldrich, Inc., 111 F. Supp. 71 (DCPR) affirmed 214 F. 2d 703 (CA-1); see also Aetna Finance Co. v. Mitchell, 247 F...

  16. 29 CFR 779.324 - Recognition “in.”

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... emphasized in the debates in Congress that while the views of an industry are significant and material in... Tire Co., 383 U.S. 190; Mitchell v. City Ice Co., 273 F. 2d 560 (CA-5); Durkin v. Casa Baldrich, Inc., 111 F. Supp. 71 (DCPR) affirmed 214 F. 2d 703 (CA-1); see also Aetna Finance Co. v. Mitchell, 247 F...

  17. 29 CFR 570.108 - “Produced”.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the products of industry where existing raw materials are transformed into new or different articles... type of productive activity involving the taking of materials from the ground, such as coal from a coal... Mercantile Co., 153 F. 2d 153 (C.A. 5), where the court directed issuance of injunctions to restrain...

  18. 29 CFR 570.108 - “Produced”.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the products of industry where existing raw materials are transformed into new or different articles... type of productive activity involving the taking of materials from the ground, such as coal from a coal... Mercantile Co., 153 F. 2d 153 (C.A. 5), where the court directed issuance of injunctions to restrain...

  19. 29 CFR 570.108 - “Produced”.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the products of industry where existing raw materials are transformed into new or different articles... type of productive activity involving the taking of materials from the ground, such as coal from a coal... Mercantile Co., 153 F. 2d 153 (C.A. 5), where the court directed issuance of injunctions to restrain...

  20. 29 CFR 779.324 - Recognition “in.”

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... emphasized in the debates in Congress that while the views of an industry are significant and material in... Tire Co., 383 U.S. 190; Mitchell v. City Ice Co., 273 F. 2d 560 (CA-5); Durkin v. Casa Baldrich, Inc., 111 F. Supp. 71 (DCPR) affirmed 214 F. 2d 703 (CA-1); see also Aetna Finance Co. v. Mitchell, 247 F...

  1. Comparative Efficacy of Potassium Levulinate with/without Potassium Diacetate and Potassium Propionate vs Potassium Lactate and Sodium Diacetate for Control of Listeria monocytogenes on commercially prepared uncured t.breast

    USDA-ARS?s Scientific Manuscript database

    We evaluated the efficacy of potassium levulinate, potassium diacetate, and potassium propionate to inhibit Listeria monocytogenes on commercially-prepared, uncured turkey breast during refrigerated storage. Whole muscle, uncured turkey breast chubs (ca. 5 kg each) were formulated with or without po...

  2. Verification of Aerosol Optical Depth Retrievals using Cloud Shadows Retrieved from Satellite Imagery

    DTIC Science & Technology

    2008-03-01

    ASTER imagery used in this investigation were obtained through the National Geospatial- Intelligence Agency via the Commercial Satellite Imagery...Naval Postgraduate School, CA, 5-10, 143-152. Wehrli, C., 1985: Extraterrestrial Solar Spectrum – Publ. 615. Physical Meteorological

  3. The adsorption of preferential binding peptides to apatite-based materials

    PubMed Central

    Segvich, Sharon J.; Smith, Hayes C.; Kohn, David H.

    2009-01-01

    The objective of this work was to identify peptide sequences with high affinity to bone-like mineral (BLM) to provide alternative design methods for functional bone regeneration peptides. Adsorption of preferential binding peptide sequences on four apatite-based substrates [BLM and three sintered apatite disks pressed from powders containing 0% CO32− (HA), 5.6% CO32− (CA5), 10.5% CO32− (CA10)] with varied compositions and morphologies was investigated. A combination of phage display, ELISA, and computational modeling was used to elucidate three 12-mer peptide sequences APWHLSSQYSRT (A), STLPI-PHEFSRE (S), and VTKHLNQISQSY (V), from 243 candidates with preferential adsorption on BLM and HA. Overall, peptides S and V have a significantly higher adsorption to the apatite-based materials in comparison to peptide A (for S vs. A, BLM p = 0.001, CA5 p < 0.001, CA10 p < 0.001, HA p = 0.038; for V vs. A, BLM p = 0.006, CA5 p = 0.033, CA10 p = 0.029). FT-IR analysis displayed carbonate levels in CA5 and CA10 dropped to approximately 1.1–2.2% after sintering, whereas SEM imaging displayed CA5 and CA10 possess distinct morphologies. Adsorption results normalized to surface area indicate that small changes in carbonate percentage at a similar morphological scale did not provide enough carbonate incorporation to show statistical differences in peptide adsorption. Because the identified peptides (S and V) have preferential binding to apatite, their use can now be investigated in bone and dentin tissue engineering, tendon and ligament repair, and enamel formation. PMID:19095299

  4. An investigation of the immediate and storage effects of chemical treatments on Campylobacter and sensory characteristics of poultry meat.

    PubMed

    Meredith, H; Walsh, D; McDowell, D A; Bolton, D J

    2013-09-02

    Campylobacteriosis is the most common foodborne bacterial infection in developed countries and many cases are associated with poultry. This study investigated the immediate and storage effect of dipping inoculated poultry skin samples in trisodium phosphate (TSP, 10 & 14%, w/v), lactic acid (LA, 1 & 5%, v/v), citric acid (CA, 1 & 5%, w/v), peroxyacids (POA, 100 & 200 ppm) and acidified sodium chlorite (ASC, 500 & 1200 ppm). Spray application was also tested using the higher concentrations in the laboratory. In a broiler processing plant the efficacy of using TSP (14%) and CA (5%) applied by immersion and spray was investigated using naturally contaminated carcasses and the effect of these treatments on the sensory attributes of a skin-on (drumstick) and skin-off (fillet) raw and cooked product was assessed using descriptive sensory analysis. In the laboratory, immersion in TSP (14%), LA (5%), CA (5%) and ASC (1200 ppm) significantly (P<0.05) reduced the Campylobacter counts and a 2.5 to 3 log10 cfu/cm(2) reduction was observed within the shelf-life (3-5 days) of poultry meat. Spraying was ineffective even after storage. In the broiler processing plant, immersion in TSP (14%) or CA (5%) achieved Campylobacter reductions of 2.49 and 1.44 log10 cfu/cm(2), respectively. There were no significant differences between the treatments for any of the attributes measured in either raw or cooked drumsticks. The 'colour' of raw chicken fillets treated with both TSP (14%, w/v) and CA (5%, w/v) was significantly (P≤0.05) lighter than that of control samples. The 'intensity of chicken odour' and the perception of 'salt' in cooked chicken fillets treated with CA (5%, w/v) were also significantly (P≤0.05) higher than that of either control or TSP (14%, w/v) treated samples. It was concluded that TSP (14%) or CA (5%) could be applied to significantly reduce Campylobacter contamination of broilers without adversely affecting the sensory quality of the product. © 2013.

  5. Kinin receptor classification.

    PubMed

    Regoli, D; Jukic, D; Tousignant, C; Rhaleb, N E

    1992-01-01

    Apparent affinities of kinin agonists and antagonists were determined in terms of pD2 and pA2 respectively, on three isolated smooth muscles: rabbit jugular vein (Rb.J.V.), rabbit aorta (Rb.A.) and guinea pig ileum (G.P.I.). Both kinin agonists and antagonists were evaluated for their ability to induce the release of histamine from rat mastocytes. Our results indicate that the kininase I metabolites (desArg9-BK and desArg10-KD) were inactive on Rb.J.V. and G.P.I. (B2 preparations) and were full agonists on Rb.A. (B1) while [Tyr(Me)8]-BK and [Hyp3,Tyr(Me)8]-BK were inactive on Rb.A. and maintain a high affinity on Rb.J.V. and G.P.I. In addition, [Hyp3]-BK was a potent agonist on Rb.J.V. (pD2 = 8.88) and was of a moderate affinity on G.P.I. (pD2 = 7.27). On the other hand, the affinity of [Aib7]-BK was identical to that of BK on G.P.I. (pD2 = 7.90) but drastically reduced in Rb.J.V. (pD2 = 6.28). Conctractile effects of kinins in the Rb.J.V. and G.P.I. were reduced or eliminated by B2 receptor antagonists but at different concentration levels (e.g. DArg[Hyp3,DPhe7,Leu8]-BK showed pA2 values of 8.86 on Rb.J.V., but only 6.77 on G.P.I. DArg[Hyp3,Gly6,Leu8]BK showed high affinity on Rb.J.V. (pA2 = 7.60) but was a full agonist on G.P.I. Conversely, DArg[Tyr3,DPhe7,Leu8,BK] showed high agonistic activity on Rb.J.V. (pD2 = 8.30, alpha E = 1.0) and showed a pA2 value of 6.80 on G.P.I. All compounds (agonists and antagonists) were quite potent on histamine release induced in rat mastocytes. [Arg1(Tos),Hyp3,Thi5,DTic7,Oic8]-BK and DArg[Hyp3,Thi5,DTic7,Oic8]-BK showed almost similar pA2 values on both Rb.J.V. and G.P.I., but were inactive on Rb.A. (B1). These results suggest that kinins act on at least four functional sites: B1 (Rb.A.), B2A (Rb.J.V.), B2B (G.P.I.) and BH. However, there is no clear evidence of a kinin receptor on rat mast cells and the release of histamine may simply be a non-receptor phenomenon. Our data also show that B2A and B2B receptor subtypes might simply be variations of the B2 receptor in different species.

  6. Preictal dynamics of EEG complexity in intracranially recorded epileptic seizure: a case report.

    PubMed

    Bob, Petr; Roman, Robert; Svetlak, Miroslav; Kukleta, Miloslav; Chladek, Jan; Brazdil, Milan

    2014-11-01

    Recent findings suggest that neural complexity reflecting a number of independent processes in the brain may characterize typical changes during epileptic seizures and may enable to describe preictal dynamics. With respect to previously reported findings suggesting specific changes in neural complexity during preictal period, we have used measure of pointwise correlation dimension (PD2) as a sensitive indicator of nonstationary changes in complexity of the electroencephalogram (EEG) signal. Although this measure of complexity in epileptic patients was previously reported by Feucht et al (Applications of correlation dimension and pointwise dimension for non-linear topographical analysis of focal onset seizures. Med Biol Comput. 1999;37:208-217), it was not used to study changes in preictal dynamics. With this aim to study preictal changes of EEG complexity, we have examined signals from 11 multicontact depth (intracerebral) EEG electrodes located in 108 cortical and subcortical brain sites, and from 3 scalp EEG electrodes in a patient with intractable epilepsy, who underwent preoperative evaluation before epilepsy surgery. From those 108 EEG contacts, records related to 44 electrode contacts implanted into lesional structures and white matter were not included into the experimental analysis.The results show that in comparison to interictal period (at about 8-6 minutes before seizure onset), there was a statistically significant decrease in PD2 complexity in the preictal period at about 2 minutes before seizure onset in all 64 intracranial channels localized in various brain sites that were included into the analysis and in 3 scalp EEG channels as well. Presented results suggest that using PD2 in EEG analysis may have significant implications for research of preictal dynamics and prediction of epileptic seizures.

  7. Attenuation of the anti-contractile effect of cooling in the rat aorta by perivascular adipose tissue.

    PubMed

    Rafique, Y; AlBader, M; Oriowo, M

    2017-09-01

    In addition to providing mechanical support for blood vessels, the perivascular adipose tissue (PVAT) secretes a number of vasoactive substances and exerts an anticontractile effect. The main objective of this study was to find out whether the anticontractile effect of cooling in the rat aorta is affected by PVAT. Our hypothesis was that PVAT would enhance the anticontractile effect of cooling in the rat aorta. Aorta segments, with or without PVAT, were used in this investigation. Cumulative concentration-response curves were established for phenylephrine at 37°C or 24°C. Phenylephrine (10 -9 M - 10 -5 M) induced concentration-dependent contractions of aorta segments with or without PVAT at 37°C. The maximum response, but not pD 2 value, was reduced in aorta segments with PVAT. Cooling the tissues to 24 °C resulted in a significant reduction in the maximum response in aorta segments without PVAT with no change in pD 2 values. However, the anticontractile effect of cooling was attenuated in the presence of PVAT with no significant (p > 0.05) change in either the maximum response or pD 2 value. L-NAME potentiated PE-induced contractions and this was greater in aorta segments without PVAT at both temperatures. The expression of eNOS protein and basal tissue level of nitric oxide (NO) were greater in aorta segments with PVAT at both temperatures. However, PE significantly increased tissue levels of NO only in aorta segments without PVAT. We concluded that PVAT-induced loss of anticontractile effect of cooling against PE-induced contractions could be due to impaired generation of NO in aorta segments with PVAT. © 2017 John Wiley & Sons Ltd.

  8. Irrigation dose and plant density affect the volatile composition and sensory quality of dill (Anethum graveolens L.).

    PubMed

    El-Zaeddi, Hussein; Martínez-Tomé, Juan; Calín-Sánchez, Ángel; Burló, Francisco; Carbonell-Barrachina, Ángel A

    2017-01-01

    Two independent field experiments were carried out to investigate the influence of (i) three irrigation treatments (ID0 = 1585 m 3 ha -1 , considered as a control; ID1 = 1015 m 3 ha -1 ; and ID2 = 2180 m 3 ha -1 ) and (ii) three plant density treatments (PD0 = 5.56 plants m -2 , considered as a control; PD1 = 4.44 plants m -2 ; and PD2 = 7.41 plants m -2 ) on the production, volatile composition of essential oil, and sensory quality of dill. The highest plant yield was obtained with intermediate conditions of both irrigation dose (ID0) and plant density (PD0). The main compounds of the essential oil were α-phellandrene, dill ether and β-phellandrene. The highest irrigation dose (ID2) produced the highest concentrations of most of the main compounds: α-phellandrene (49.5 mg per 100 g), β-phellandrene (6.89 mg per 100 g) and limonene (2.49 mg per 100 g). A similar pattern was found for the highest plant density (PD2): α-phellandrene (71.0 mg per 100 g), dill ether (16.7 mg per 100 g) and β-phellandrene (9.70 mg per 100 g). The use of descriptive sensory analysis helped in reaching a final decision, and the dill plants with the highest sensory quality were those of the ID2 and PD0 treatments. The final recommendation is to use the irrigation dose ID2 and the plant density PD2 if the objective is to produce dill samples with the highest aromatic and sensory quality; however, if the only objective is to produce high amounts of dill, the best options are ID0 and PD0. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  9. Cyclopalladation of dimesityl selenide: synthesis, reactivity, structural characterization, isolation of an intermediate complex with C-H···Pd intra-molecular interaction and computational studies.

    PubMed

    Kolay, Siddhartha; Wadawale, Amey; Das, Dasarathi; Kisan, Hemanta K; Sunoj, Raghavan B; Jain, Vimal K

    2013-08-14

    The reaction of dimesityl selenide (Mes2Se) with either PdCl2(PhCN)2 in toluene or PdCl2 in toluene-acetonitrile yields a chloro-bridged binuclear palladium complex, [Pd2Cl2(μ-Cl)2(Mes2Se)2] (1), whereas with Na2PdCl4 in refluxing ethanol, a cyclometallated palladium complex, [Pd2(μ-Cl)2{MesSeC6H2(Me2)CH2}2] (2) is afforded. 2 can also be obtained when 1 is refluxed in ethanol. On treatment with Pb(Epy)2 in dichloromethane, 2 afforded the Epy-bridged binuclear complexes, [Pd2(μ-Epy)2{MesSeC6H2(Me2)CH2}2] (3; E = S (3a) or Se (3b)). Treatment of 2 with PPh3 yields a bridge-cleaved monomeric complex, [PdCl{MesSeC6H2(Me2)CH2}(PPh3)]. The molecular structures of 1-3 were established by X-ray diffraction analyses. All the complexes are dimeric, with the palladium atoms acquiring a distorted square planar configuration. There are intra-molecular C-H···Pd interactions (d(M-H): 2.75 Å and

  10. Investigation of magnetic order in SmTr2Zn20 (Tr = Fe, Co, Ru) and SmTr2Cd20 (Tr = Ni, Pd)

    NASA Astrophysics Data System (ADS)

    Yazici, Duygu; White, B. D.; Ho, P.-C.; Kanchanavatee, N.; Huang, K.; Dilley, N. R.; Maple, M. B.

    2015-03-01

    Single crystals of the cage compounds Sm Tr 2Zn20 (Tr = Fe, Co, Ru) and Sm Tr 2Cd20 (Tr = Ni, Pd) have been investigated by means of electrical resistivity, magnetization, and specific heat measurements. The compounds SmFe2Zn20, SmRu2Zn20,andSmNi2Cd20 exhibit ferromagnetic order with Curie temperatures of TC = 47.4 K, 7.6 K, and 7.5 K, respectively, whereas SmPd2Cd20 is an antiferromagnet with a Néel temperature of TN = 3.4 K. No evidence for magnetic order is observed in SmCo2Zn20 down to 110 mK. The Sommerfeld coefficients γ are found to be 57 mJ/mol-K2 for SmFe2Zn20, 79.5 mJ/mol-K2 for SmCo2Zn20, 258 mJ/mol-K2 for SmRu2Zn20, 165 mJ/mol-K2 for SmNi2Cd20, and 208 mJ/mol-K2 for SmPd2Cd20. Enhanced values of Sommerfeld coefficients γ and a quadratic temperature dependence of the electrical resistivity at low temperature for SmRu2Zn20andSmPd2Cd20 suggest an enhancement of the quasiparticle masses due to hybridization between localized 4 f and conduction electron states. Research at UCSD was supported by the U.S. DOE under Grant No. DE-FG02-04-ER46105 and the U.S. NSF under Award Grant No. DMR 1206553. Research at California State University, Fresno was supported by the U.S. NSF under Grant No. DMR 1104544.

  11. Investigation of magnetic order in SmTr2Zn20 (Tr=Fe ,Co,Ru) and SmTr2Cd20 (Tr=Ni ,Pd)

    NASA Astrophysics Data System (ADS)

    Yazici, D.; White, B. D.; Ho, P.-C.; Kanchanavatee, N.; Huang, K.; Friedman, A. J.; Wong, A. S.; Burnett, V. W.; Dilley, N. R.; Maple, M. B.

    2014-10-01

    Single crystals of the "cage compounds" SmTr2Zn20 (Tr=Fe, Co, Ru) and SmTr2Cd20 (Tr=Ni, Pd) have been investigated by means of electrical resistivity, magnetization, and specific-heat measurements. The compounds SmFe2Zn20,SmRu2Zn20, and SmNi2Cd20 exhibit ferromagnetic order with Curie temperatures of TC=47.4, 7.6, and 7.5 K, respectively, whereas SmPd2Cd20 is an antiferromagnet with a Néel temperature of TN=3.4 K. No evidence for magnetic order is observed in SmCo2Zn20 down to 110 mK. The Sommerfeld coefficients γ are found to be 57 mJ /molK2 for SmFe2Zn20,79.5 mJ /molK2 for SmCo2Zn20,258 mJ /molK2 for SmRu2Zn20,165 mJ /molK2 for SmNi2Cd20, and 208 mJ /molK2 for SmPd2Cd20. Enhanced values of γ and a quadratic temperature dependence of the electrical resistivity at low temperature for SmRu2Zn20 and SmPd2Cd20 suggest an enhancement of the quasiparticle masses due to hybridization between localized 4f and conduction electron states.

  12. Contractile effects of bradykinin on the isolated human small bronchus.

    PubMed

    Molimard, M; Martin, C A; Naline, E; Hirsch, A; Advenier, C

    1994-01-01

    Bradykinin (Bk) induced a contraction in all small bronchi samples (diameter, 0.5 to 1 mm) from 20 patients. pD2 was 7.7 +/- 0.1 (pD2 = -log EC50) and maximal effect (Emax) was 36.2 +/- 4.7% of the maximal response to acetylcholine. The B2 agonist [Hyp3TyrMe8]Bk contracted airway smooth muscle with a pD2 of 7.8 +/- 0.2 and an Emax of 39 +/- 9%. The B1 agonist [Sar1dPhe8desArg9]Bk induced only a weak contraction at 10(-6) M. The effect of Bk was abolished by the B2 (Hoe 140) but not by the B1 [Leu8desArg9]Bk receptor antagonist. Indomethacin 10(-6) M abolished Bk-induced contraction, suggesting that cyclooxygenase products are involved in Bk action. Capsaicin 10(-5) M, which selectively depletes C fibers from airway mediators through the ruthenium red pathway, and ruthenium red 10(-5) M significantly inhibited the concentration-response curves to Bk. However, tetrodotoxin (+/-)-CP-96,345, SR 48968, and atropine did not significantly affect Bk concentration-response curves, suggesting that nerve conduction, substance P (SP), neurokinin A (NKA), and acetylcholine release are not involved in Bk action. Our data indicate that Bk contracts human distal airway smooth muscle through the Bk B2 receptor and a cyclooxygenase pathway. This effect appears to involve capsaicin and ruthenium red pathways but neither acetylcholine nor NKA and SP release.

  13. Comparison of linear–stochastic and nonlinear–deterministic algorithms in the analysis of 15-minute clinical ECGs to predict risk of arrhythmic death

    PubMed Central

    Skinner, James E; Meyer, Michael; Nester, Brian A; Geary, Una; Taggart, Pamela; Mangione, Antoinette; Ramalanjaona, George; Terregino, Carol; Dalsey, William C

    2009-01-01

    Objective: Comparative algorithmic evaluation of heartbeat series in low-to-high risk cardiac patients for the prospective prediction of risk of arrhythmic death (AD). Background: Heartbeat variation reflects cardiac autonomic function and risk of AD. Indices based on linear stochastic models are independent risk factors for AD in post-myocardial infarction (post-MI) cohorts. Indices based on nonlinear deterministic models have superior predictability in retrospective data. Methods: Patients were enrolled (N = 397) in three emergency departments upon presenting with chest pain and were determined to be at low-to-high risk of acute MI (>7%). Brief ECGs were recorded (15 min) and R-R intervals assessed by three nonlinear algorithms (PD2i, DFA, and ApEn) and four conventional linear-stochastic measures (SDNN, MNN, 1/f-Slope, LF/HF). Out-of-hospital AD was determined by modified Hinkle–Thaler criteria. Results: All-cause mortality at one-year follow-up was 10.3%, with 7.7% adjudicated to be AD. The sensitivity and relative risk for predicting AD was highest at all time-points for the nonlinear PD2i algorithm (p ≤0.001). The sensitivity at 30 days was 100%, specificity 58%, and relative risk >100 (p ≤0.001); sensitivity at 360 days was 95%, specificity 58%, and relative risk >11.4 (p ≤0.001). Conclusions: Heartbeat analysis by the time-dependent nonlinear PD2i algorithm is comparatively the superior test. PMID:19707283

  14. New Tools for the Study of Combustion Chemistry and Complex Gas-Surface Interactions from First Principles

    DTIC Science & Technology

    2007-10-06

    Proffen, A. M. Rappe, S. Scott, and R. Seshadri, "BaCel-xPd,O 3-8 (0<xɘ.1): Redox controlled ingress and egress of palladium in a perovskite...methyl and the surface rhodium atoms. Such multi-center bonding leads to C-H bond depletion and is the cause of experimentally observed mode-softening...The Pd 2 - containing perovskite phases extrude elemental face-centered cubic palladium nanoparticles when heated in a reducing atmosphere. This

  15. Uncertainty Modeling for Database Design using Intuitionistic and Rough Set Theory

    DTIC Science & Technology

    2009-01-01

    Definition. An intuitionistic rough relation R is a sub- set of the set cross product P(D1)× P(D2) × · · ·× P( Dm )× Dµ.× Dv. For a specific relation, R...that aj ∈ dij for all j. The interpretation space is the cross product D1× D2 × · · ·× Dm × Dµ× Dv but is limited for a given re- lation R to the set...systems, Journal of Information Science 11 (1985), 77–87. [7] T. Beaubouef and F. Petry, Rough Querying of Crisp Data in Relational Databases, Third

  16. Novel Manufacturing Technologies for GHZ/THz Integrated Circuits on Synthetic Diamond Substrates

    DTIC Science & Technology

    2010-11-15

    silicon form palladium silicide Pd2Si at a temperature of 400 ºС, thus ensuring high reliability of the contacts. All the above metallization layers were...indicate possibility of realization of ICs on diamond substrates. In the course of our studies it was found that the Ti-Pd-Au metallization system...thickness of 2-3 um) can be applied when forming the topology of IC elements on synthetic diamond layers, while the Cr–Cu–Ni–Au metallization system with

  17. Fabrication and Properties of Multilayer Structures

    DTIC Science & Technology

    1983-09-01

    according to both the high x-ray count and a Read camera pattern which showed only the 111 8 SiC reflection in a tight ± 30 distribution about the substrate...structural rearrangement. X-ray analysis of the deposited films at the composition of Pd2 Si using a Read camera indicated strong texturing. The...Phys. 35, 547 (1964). 11. C.A. Neubauer and J.R. Randen, Proc. IEEE 52, 1234 (1964). 12. W.A. Tiller, "Fabrication and Properties of Multilayer

  18. The role of the amygdala in the pathophysiology of panic disorder: evidence from neuroimaging studies

    PubMed Central

    2012-01-01

    Although the neurobiological mechanisms underlying panic disorder (PD) are not yet clearly understood, increasing amount of evidence from animal and human studies suggests that the amygdala, which plays a pivotal role in neural network of fear and anxiety, has an important role in the pathogenesis of PD. This article aims to (1) review the findings of structural, chemical, and functional neuroimaging studies on PD, (2) relate the amygdala to panic attacks and PD development, (3) discuss the possible causes of amygdalar abnormalities in PD, (4) and suggest directions for future research. PMID:23168129

  19. Lightweight magnesium nanocomposites: electrical conductivity of liquid magnesium doped by CoPd nanoparticles

    NASA Astrophysics Data System (ADS)

    Yakymovych, Andriy; Slabon, Adam; Plevachuk, Yuriy; Sklyarchuk, Vasyl; Sokoliuk, Bohdan

    2018-04-01

    The effect of monodisperse bimetallic CoPd NP admixtures on the electrical conductivity of liquid magnesium was studied. Temperature dependence of the electrical conductivity of liquid Mg98(CoPd)2, Mg96(CoPd)4, and Mg92(CoPd)8 alloys was measured in a wide temperature range above the melting point by a four-point method. It was shown that the addition of even small amount of CoPd nanoparticles to liquid Mg has a significant effect on the electrical properties of the melts obtained.

  20. New Reactive Diluents for an Environmentally Efficient Approach to Composite Repair

    DTIC Science & Technology

    2010-02-16

    7.25 ppm, δ 77.0 ppm; MeOH-δ4, d 3.31 ppm, δ 49.15 ppm. The n-BuLi (2.5 M in hexanes), 4,4’-dibromophenyl ether, vinyl tributyltin , THF (anhydrous...4’-tributylsilyldiphenyl ether (34.48 g, 79 mmol), CsF, (25.28 g, 166 mmol), vinyl tributyltin (27.65 g, 87 mmol), Pd2(dba)3 (3.63 g, 4.0 mmol), and

  1. State Estimation of a Hybrid Markov Process with Application to Multitarget Tracking.

    DTIC Science & Technology

    1982-01-01

    k (d k))T P (dk - k -1 k kP~d kzk ) IPk~k (d k) (.Zkik (d 2) - xkk dl)) + 2 2.n P~-d k 1zk n J k ( .15d2 I) Ipklk1dk)I 66 k < c k an kk k if Pkk(d I...bealat more likely at time k, i.e., P(d kzk ) < P(d2[zk). Thus, if we want to kdiscard a given sequence d0, we try to compare it only with other more k

  2. Palladium-catalyzed cyclization reactions of 2-vinylthiiranes with heterocumulenes. Regioselective and enantioselective formation of thiazolidine, oxathiolane, and dithiolane derivatives.

    PubMed

    Larksarp, C; Sellier, O; Alper, H

    2001-05-18

    The first palladium-catalyzed ring-expansion reaction of 2-vinylthiiranes with heterocumulenes to form sulfur-containing five-membered-ring heterocycles is described. This regioselective reaction requires 5 mol % of Pd(2)(dba)(3).CHCl(3) and 10 mol % of bidendate phosphine ligand (dppp, BINAP), at 50-80 degrees C, in THF. The reaction of 2-vinylthiiranes with carbodiimides, isocyanates, and ketenimines affords 1,3-thiazolidine derivatives, whereas the reaction with diphenylketene or isothiocyanates results in the formation of 1,3-oxathiolane or 1,3-dithiolane compounds in good to excellent isolated yields and in up to 78% ee.

  3. Simultaneous introduction of various palladium active sites into MOF via one-pot synthesis: Pd@[Cu3-xPdx(BTC)2]n.

    PubMed

    Zhang, Wenhua; Chen, Zhihao; Al-Naji, Majd; Guo, Penghu; Cwik, Stefan; Halbherr, Olesia; Wang, Yuemin; Muhler, Martin; Wilde, Nicole; Gläser, Roger; Fischer, Roland A

    2016-10-14

    Simultaneous incorporation of palladium within Pd-Pd and/or Pd-Cu paddlewheels as framework-nodes and Pd nanoparticle (NP) dispersion into MOF have been achieved for the first time via one-pot synthesis. In particular, the framework substitution of Cu(2+) by Pd(2+) as well as the pore loading with PdNPs have been confirmed and characterized by XPS. The obtained solids featuring such multiple Pd-sites show enhanced catalytic activity in the aqueous-phase hydrogenation of p-nitrophenol (PNP) with NaBH4 to p-aminophenol (PAP).

  4. Sustained Attention Training Reduces Spatial Bias in Parkinson's Disease: A Pilot Case Series

    PubMed Central

    DeGutis, Joseph; Grosso, Mallory; VanVleet, Thomas; Esterman, Michael; Pistorino, Laura; Cronin-Golomb, Alice

    2016-01-01

    Individuals with Parkinson’s disease (PD) commonly demonstrate lateralized spatial biases, which affect daily functioning. Those with PD with initial motor symptoms on the left body side (LPD) have reduced leftward attention whereas PD with initial motor symptoms on the right side (RPD) may display reduced rightward attention. We investigated whether a sustained attention training program could help reduce these spatial biases. Four non-demented individuals with PD (2 LPD/2 RPD) performed a visual search task before and after one month of computer training. Before training, all participants showed a significant spatial bias and after training, all participants’ spatial bias was eliminated. PMID:26360648

  5. Sustained attention training reduces spatial bias in Parkinson's disease: a pilot case series.

    PubMed

    DeGutis, Joseph; Grosso, Mallory; VanVleet, Thomas; Esterman, Michael; Pistorino, Laura; Cronin-Golomb, Alice

    2016-01-01

    Individuals with Parkinson's disease (PD) commonly demonstrate lateralized spatial biases, which affect daily functioning. Those with PD with initial motor symptoms on the left body side (LPD) have reduced leftward attention, whereas PD with initial motor symptoms on the right side (RPD) may display reduced rightward attention. We investigated whether a sustained attention training program could help reduce these spatial biases. Four non-demented individuals with PD (2 LPD, 2 RPD) performed a visual search task before and after 1 month of computer training. Before training, all participants showed a significant spatial bias and after training, all participants' spatial bias was eliminated.

  6. Reversible Tailoring of Mechanical Properties of Carbon Nanotube Forests by Immersing in Solvents

    DTIC Science & Technology

    2014-12-07

    quantify the strength of vdW interactions between CNTs, Hamaker constant of CNTs in vacuum, Av ¼ V 12pD 2 G , was evaluated where ‘V’ is the vdW...effectively do not interact with each other. Therefore, we assumed curved surface–surface vdW interaction between two CNTs to evaluate the Hamaker ...of the vdW forces are directly proportional to Hamaker constant, which depends on the macroscopic properties of the interacting objects and the

  7. Reversible capture of small molecules on bimetallaborane clusters: synthesis, structural characterization, and photophysical aspects.

    PubMed

    Bould, Jonathan; Baše, Tomáš; Londesborough, Michael G S; Oro, Luis A; Macías, Ramón; Kennedy, John D; Kubát, Pavel; Fuciman, Marcel; Polívka, Tomáš; Lang, Kamil

    2011-08-15

    Metallaborane compounds containing two adjacent metal atoms, [(PMe(2)Ph)(4)MM'B(10)H(10)] (where MM' = Pt(2), 1; PtPd, 7; Pd(2), 8), have been synthesized, and their propensity to sequester O(2), CO, and SO(2) and to then release them under pulsed and continuous irradiation are described. Only [(PMe(2)Ph)(4)Pt(2)B(10)H(10)], 1, undergoes reversible binding of O(2) to form [(PMe(2)Ph)(4)(O(2))Pt(2)B(10)H(10)] 3, but solutions of 1, 7, and 8 all quantitatively take up CO across their metal-metal vectors to form [(PMe(2)Ph)(4)(CO)Pt(2)B(10)H(10)] 4, [(PMe(2)Ph)(4)(CO)PtPdB(10)H(10)] 10, and [(PMe(2)Ph)(4)(CO)Pd(2)B(10)H(10)] 11, respectively. Crystallographically determined interatomic M-M distances and infrared CO stretching frequencies show that the CO molecule is bound progressively more weakly in the sequence {PtPt} > {PtPd} > {PdPd}. Similarly, SO(2) forms [(PMe(2)Ph)(4)(SO(2))Pt(2)B(10)H(10)] 5, [(PMe(2)Ph)(4)(SO(2))PtPdB(10)H(10)] 12, and [(PMe(2)Ph)(4)(SO(2))Pd(2)B(10)H(10)] 13 with progressively weaker binding of the SO(2) molecule. The uptake and release of gas molecules are accompanied by changes in their absorption spectra. Nanosecond transient absorption spectroscopy clearly shows that the O(2) and CO molecules are liberated from the bimetallic binding site with high quantum yields of about 0.6. For 3, in addition to dioxygen release in the triplet ground state, singlet oxygen O(2)((1)Δ(g)) was also detected with a quantum yield <0.01. In most cases, the release and rebinding of the gas molecules can be cycled with little photodegradation of the compounds. Femtosecond transient absorption spectroscopy further reveals that the photorelease of the O(2) and CO molecules, from 3 and 4 respectively, is an ultrafast process taking place on a time scale of tens of picoseconds. For SO(2), the release is even faster (<1 ps), but only in the case of mixed metal PtPd adducts, most probably because of the metal-metal bonding asymmetry in the mixed metal clusters

  8. Growth and Doping of Al(x)Ga(1-x)N Films by Electron Cyclotron Resonance Assisted Molecular Beam Epitaxy

    DTIC Science & Technology

    1993-05-30

    shown in Figures 9a and 9b. The carrier concentration was computed from the measured values of the Hall coefficient, RH , using the equation n (5) eRH...The electron concentrations in Figure 1 were calculated from the expression 1 (1) eRjj where RH is the Hall constant. Equation (1) assumes electron...expressions: 2 2RH fcP + ,’dP• (2) RH = (ncp + nd/pd) 2 e 1 p 1 (3) ncelc + ndel.d where nc and nd are the concentrations of conducting carriers in the

  9. The unusual chemical bonding and thermoelectric properties of a new type Zintl phase compounds Ba3Al2As4

    NASA Astrophysics Data System (ADS)

    Yang, Gui; Zhang, Guangbiao; Wang, Chao; Wang, Yuanxu

    2016-07-01

    Ba3Al2As4 exhibits an unusual anisotropic electrical conductivity, that is, the electrical conductivity along the chain is smaller than those along other two directions. The results is conflict with previous conclusion for Ca5M2Pn6. Earlier studies on Ca5M2Pn6 showed that a higher electrical conductivity could be obtained along the chain. The band decomposed charge density is used to explain such unusual behavior. Our calculations indicate the existence of a conductive pathway near the Fermi level is responsible for the electrons transport. Further, the Ba-As bonding of Ba3Al2As4 has some degree covalency which is novel for the Zintl compounds.

  10. DcSto: carrot Stowaway-like elements are abundant, diverse, and polymorphic

    USDA-ARS?s Scientific Manuscript database

    We investigated nine families of Stowaway-like MITEs in the carrot genome, named DcSto1 to DcSto9. All of them were AT-rich and shared a highly conserved 6 bp-long TIR typical for Stowaways. The copy number of DcSto1 elements was estimated as ca. 5,000 per diploid genome. We observed preference for ...

  11. Analysis of Pacific Fleet Underway Replenishment Data

    DTIC Science & Technology

    1988-09-01

    described in Chapter 12 of NWP-I IE predicts requirements to support the operating forces. Ad- equate material (POL Ammunition Stores) must be available to...Mr. John Hammet at NSWSES, Port Hueneme, CA. 5 moving material between ships is established, however the procedures to control the material moved is...represent faster transfers. As an example 15 minutes per thousand barrels equates to 4000 barrels per hour while 20 minutes per thousand barrels equates

  12. HOT CELL BUILDING, TRA632. WHILE STEEL BEAMS DEFINE FUTURE WALLS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HOT CELL BUILDING, TRA-632. WHILE STEEL BEAMS DEFINE FUTURE WALLS OF THE BUILDING, SHEET STEEL DEFINES THE HOT CELL "BOX" ITSELF. THREE OPERATING WINDOWS ON LEFT; ONE VIEWING WINDOW ON RIGHT. TUBES WILL CONTAIN SERVICE AND CONTROL LEADS. SPACE BETWEEN INNER AND OUTER BOX WALLS WILL BE FILLED WITH SHIELDED WINDOWS AND BARETES CONCRETE. CAMERA FACES SOUTHEAST. INL NEGATIVE NO. 7933. Unknown Photographer, ca. 5/1953 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  13. An Aerobic Digestion of Lime Sludge.

    DTIC Science & Technology

    1982-07-01

    removal. 1,2 After lime addition, phosphorus is considered to be in the form of calcium hydroxyapatite (Ca5-(OH)(P04 )3 ), which will not resolubilize...U: c a e - ~ -’ tr *cr. V. (r. C . -~~~ C c C C&c cj Ir u -. C Fy. - U C C - C F.~-cc 0.c gC - - gg MFC - - C -66 TABLE 20. SUMMARY OF LEAST

  14. Calcium and stretch activation modulate power generation in Drosophila flight muscle.

    PubMed

    Wang, Qian; Zhao, Cuiping; Swank, Douglas M

    2011-11-02

    Many animals regulate power generation for locomotion by varying the number of muscle fibers used for movement. However, insects with asynchronous flight muscles may regulate the power required for flight by varying the calcium concentration ([Ca(2+)]). In vivo myoplasmic calcium levels in Drosophila flight muscle have been found to vary twofold during flight and to correlate with aerodynamic power generation and wing beat frequency. This mechanism can only be possible if [Ca(2+)] also modulates the flight muscle power output and muscle kinetics to match the aerodynamic requirements. We found that the in vitro power produced by skinned Drosophila asynchronous flight muscle fibers increased with increasing [Ca(2+)]. Positive muscle power generation started at pCa = 5.8 and reached its maximum at pCa = 5.25. A twofold variation in [Ca(2+)] over the steepest portion of this curve resulted in a two- to threefold variation in power generation and a 1.2-fold variation in speed, matching the aerodynamic requirements. To determine the mechanism behind the variation in power, we analyzed the tension response to muscle fiber-lengthening steps at varying levels of [Ca(2+)]. Both calcium-activated and stretch-activated tensions increased with increasing [Ca(2+)]. However, calcium tension saturated at slightly lower [Ca(2+)] than stretch-activated tension, such that as [Ca(2+)] increased from pCa = 5.7 to pCa = 5.4 (the range likely used during flight), stretch- and calcium-activated tension contributed 80% and 20%, respectively, to the total tension increase. This suggests that the response of stretch activation to [Ca(2+)] is the main mechanism by which power is varied during flight. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  15. Nonyloxytryptamine Mimics Polysialic Acid and Modulates Neuronal and Glial Functions in Cell Culture

    DTIC Science & Technology

    2014-01-01

    polysialic acid (PSA) and 5-nonyloxytryptamine oxalate (5- NOT). (a) Shape and chemistry of PSA, shown as a surface, superimposed with the 3D structure of...process formation of Schwann cells (c) was determined in the presence and absence of colominic acid (CA), 5-nonyloxytryptamine oxalate (5-NOT) and 5-HT1B... oxalate (5-NOT) competes with colominic acid for binding to the PSA-specific antibody 735 (mAb 735). Figure S2. Representative images of (a) cerebellar

  16. 29 CFR 776.23 - Employment in the construction industry.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... Sondeck, 132 F. (2d) 77 (C.A. 5), certiorari denied 318 U.S. 772; Kirschbaum v. Walling, ante; Walling v. McCrady Construction Co., 156 F. (2d) 932. certiorari denied 329 U.S. 785; Mitchell v. Brown Engineering Co., 224 F. (2d) 359 (C.A. 8), certiorari denied 350 U.S. 875; Chambers Construction Co. and L. H...

  17. 29 CFR 776.23 - Employment in the construction industry.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Sondeck, 132 F. (2d) 77 (C.A. 5), certiorari denied 318 U.S. 772; Kirschbaum v. Walling, ante; Walling v. McCrady Construction Co., 156 F. (2d) 932. certiorari denied 329 U.S. 785; Mitchell v. Brown Engineering Co., 224 F. (2d) 359 (C.A. 8), certiorari denied 350 U.S. 875; Chambers Construction Co. and L. H...

  18. 29 CFR 776.23 - Employment in the construction industry.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... Sondeck, 132 F. (2d) 77 (C.A. 5), certiorari denied 318 U.S. 772; Kirschbaum v. Walling, ante; Walling v. McCrady Construction Co., 156 F. (2d) 932. certiorari denied 329 U.S. 785; Mitchell v. Brown Engineering Co., 224 F. (2d) 359 (C.A. 8), certiorari denied 350 U.S. 875; Chambers Construction Co. and L. H...

  19. 29 CFR 776.23 - Employment in the construction industry.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... Sondeck, 132 F. (2d) 77 (C.A. 5), certiorari denied 318 U.S. 772; Kirschbaum v. Walling, ante; Walling v. McCrady Construction Co., 156 F. (2d) 932. certiorari denied 329 U.S. 785; Mitchell v. Brown Engineering Co., 224 F. (2d) 359 (C.A. 8), certiorari denied 350 U.S. 875; Chambers Construction Co. and L. H...

  20. MetalMapper Demonstration at the Former Camp Beale, CA

    DTIC Science & Technology

    2012-03-01

    2012 2 . REPORT TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE MetalMapper Demonstration at the Former Camp Beale, CA 5a...SUMMARY REPORT MetalMapper Demonstration at the Former Camp Beale, CA March 2012 Herb Nelson Anne Andrews SERDP & ESTCP...advanced electromagnetic sensor was demonstrated at the former Camp Beale, CA in 2011. Camp Beale was also the site of the first demonstrations of

  1. ESTCP Live Site Demonstrations Former Camp Beale, Marysville, CA

    DTIC Science & Technology

    2011-08-23

    ESTCP Live Site Demonstrations Former Camp Beale Marysville, CA ESTCP MR-201165 Demonstration Data Report Former Camp Beale...with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE AUG 2011 2 . REPORT TYPE N/A 3. DATES...COVERED - 4. TITLE AND SUBTITLE ESTCP Live Site Demonstrations Former Camp Beale Marysville, CA 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  2. Kinetic Studies of Calcium-Induced Calcium Release in Cardiac Sarcoplasmic Reticulum Vesicles

    PubMed Central

    Sánchez, Gina; Hidalgo, Cecilia; Donoso, Paulina

    2003-01-01

    Fast Ca2+ release kinetics were measured in cardiac sarcoplasmic reticulum vesicles actively loaded with Ca2+. Release was induced in solutions containing 1.2 mM free ATP and variable free [Ca2+] and [Mg2+]. Release rate constants (k) were 10-fold higher at pCa 6 than at pCa 5 whereas Ryanodine binding was highest at pCa ≤5. These results suggest that channels respond differently when exposed to sudden [Ca2+] changes than when exposed to Ca2+ for longer periods. Vesicles with severalfold different luminal calcium contents exhibited double exponential release kinetics at pCa 6, suggesting that channels undergo time-dependent activity changes. Addition of Mg2+ produced a marked inhibition of release kinetics at pCa 6 (K0.5 = 63 μM) but not at pCa 5. Coexistence of calcium activation and inhibition sites with equally fast binding kinetics is proposed to explain this behavior. Thimerosal activated release kinetics at pCa 5 at all [Mg2+] tested and increased at pCa 6 the K0.5 for Mg2+ inhibition, from 63 μM to 136 μM. We discuss the possible relevance of these results, which suggest release through RyR2 channels is subject to fast regulation by Ca2+ and Mg2+ followed by time-dependent regulation, to the physiological mechanisms of cardiac channel opening and closing. PMID:12668440

  3. The relationship between the electronic structure and thermoelectric properties of Zintl compounds M2Zn5As4 (M = K, Rb).

    PubMed

    Yang, Gui; Yang, Jueming; Yan, Yuli; Wang, Yuanxu

    2014-03-28

    The electronic structure and the thermoelectric properties of M2Zn5As4 (M = K, Rb) are studied by the first principles and the semiclassical BoltzTraP theory. It is determined that they are semiconductors with an indirect band gap of about 1 eV, which is much larger than that of Ca5Al2Sb6 (0.50 eV). The calculated electronic localization function indicates that they are typical Zintl bonding compounds. The combination of heavy and light bands near the valence band maximum may improve their thermoelectric performance. Rb2Zn5As4 exhibits relatively large Seebeck coefficients, high electrical conductivities, and the large "maximum" thermoelectric figures of merit (ZeT). Compared with Ca5Al2Sb6, the highest ZeT of Rb2Zn5As4 appears at relatively low carrier concentration. For Rb2Zn4As5, the p-type doping may achieve a higher thermoelectric performance than n-type doping. The thermoelectric properties of Rb2Zn5As4 are possibly superior to those of Ca5Al2Sb6.

  4. Pleistocene glaciation of the Jackson Hole area, Wyoming

    USGS Publications Warehouse

    Pierce, Kenneth L.; Licciardi, Joseph M.; Good, John M.; Jaworowski, Cheryl

    2018-01-24

    bouldery moraines that commonly enclose lakes. On the southern margin of the GYGS, prominent glacial outwash terraces define three phases of the Pinedale glaciation in Jackson Hole: Pinedale-1 (Pd-1) by Antelope Flats with subdued channel patterns on the east side of Jackson Hole; Pinedale-2 (Pd-2) by a large outwash fan that includes Baseline Flat on the west side of Jackson Hole with well-defined channel patterns; and Pinedale-3 (Pd-3) by The Potholes and other outwash fans farther up the Snake River in central Jackson Hole. During Pinedale glaciation, three glacial lobes of the GYGS fed into Jackson Hole, and the relative importance of these lobes changed dramatically through time. During the Pd-1 glaciation, the eastern Buffalo Fork lobe dominated whereas in Pd-2 and Pd-3 time the northern Snake River lobe dominated. This is consistent with migration of the GYGS center of ice mass westward and southward as glaciers built up towards the moisture source provided by storms moving northeastward up the eastern Snake River Plain. The recession of the eastern Buffalo Fork lobe in Pd-2 and Pd-3 times is consistent with an enlarged ice mass on the Yellowstone Plateau that placed the eastern part of the GYGS in a precipitation or snow shadow.In Pd-1 time, the Buffalo Fork lobe reached its maximum extent and was joined by the Pacific Creek lobe. This culmination may correlate with the ~21–18 ka ages of moraines in the Teton Range and nearby ranges. Three subdivisions of Pd-1 glaciation built moraines that are nearly or entirely covered by outwash almost 100 meters thick. In Pd-2 time, the Snake River lobe joined with the Pacific Creek lobe and built a large outwash fan south of the present-day Jackson Lake. Boulders on a moraine at the head of this fan are dated to 15.5 ± 0.5 ka. The relation between Teton glaciers and those of the GYGS is indicated by outwash from these Pd-2 moraines that partly buries outer Jenny Lake moraines dated to 15.2 ± 0.7 ka. East of the large

  5. Identification and characterisation of the proteins bound by specific phage-displayed recombinant antibodies (scFv) obtained against Brazil nut and almond extracts.

    PubMed

    de la Cruz, Silvia; Madrid, Raquel; García-García, Aina; Alcocer, Marcos; Martín, Rosario; González, Isabel; García, Teresa

    2018-03-01

    Almonds and Brazil nuts are widely consumed allergenic nuts whose presence must be declared according to food labelling regulations. Their detection in food products has been recently achieved by ELISA methods with recombinant antibodies (scFv) isolated against complete Brazil nut and almond protein extracts. The screening of phage-scFv libraries against complete protein extracts confers a series of advantages over the use of purified proteins, as recombinant proteins might alter their native folding. However, using this strategy, the nature of the target detected by phage-displayed antibodies remains unknown, and requires further research to identify whether they are nut allergens or other molecules present in the extract, but not related to their allergenic potential. Electrophoretic, chromatographic, immunological and spectrometric techniques revealed that the Brazil nut (BE95) and almond (PD1F6 and PD2C9) specific phage-scFvs detected conformational epitopes of the Brazil nut and almond 11S globulins, recognised by WHO/IUIS as Ber e 2 and Pru du 6 major allergens. Circular dichroism data indicated that severe heat treatment would entail loss of epitope structure, disabling scFv for target detection. The presence of important Brazil nut and almond allergens (Ber e 2 and Pru du 6) in foodstuffs can be determined by using phage-display antibodies BE95, PD1F6 and PD2C9 as affinity probes in ELISA. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  6. Highly Active and Selective Hydrogenation of CO2 to Ethanol by Ordered Pd-Cu Nanoparticles.

    PubMed

    Bai, Shuxing; Shao, Qi; Wang, Pengtang; Dai, Qiguang; Wang, Xingyi; Huang, Xiaoqing

    2017-05-24

    Carbon dioxide (CO 2 ) hydrogenation to ethanol (C 2 H 5 OH) is considered a promising way for CO 2 conversion and utilization, whereas desirable conversion efficiency remains a challenge. Herein, highly active, selective and stable CO 2 hydrogenation to C 2 H 5 OH was enabled by highly ordered Pd-Cu nanoparticles (NPs). By tuning the composition of the Pd-Cu NPs and catalyst supports, the efficiency of CO 2 hydrogenation to C 2 H 5 OH was well optimized with Pd 2 Cu NPs/P25 exhibiting high selectivity to C 2 H 5 OH of up to 92.0% and the highest turnover frequency of 359.0 h -1 . Diffuse reflectance infrared Fourier transform spectroscopy results revealed the high C 2 H 5 OH production and selectivity of Pd 2 Cu NPs/P25 can be ascribed to boosting *CO (adsorption CO) hydrogenation to *HCO, the rate-determining step for the CO 2 hydrogenation to C 2 H 5 OH.

  7. Biochar-supported reduced graphene oxide composite for adsorption and coadsorption of atrazine and lead ions

    NASA Astrophysics Data System (ADS)

    Zhang, Ying; Cao, Bo; Zhao, Lulu; Sun, Lili; Gao, Yan; Li, Jiaojiao; Yang, Fan

    2018-01-01

    To explore potential in application for simultaneous removal of atrazine and lead ions (Pd2+), the adsorption and coadsorption of atrazine and Pd2+ is evaluated onto a novel biochar-supported reduced graphene oxide composite (RGO-BC), which has been successfully developed via slow pyrolysis of graphene oxide (GO) pretreated corn straws. Structure and morphology analysis reveal that GO nanosheets are coated on the surface of biochar (BC) mainly through π-π interactions, notably, GO nanosheets after annealing reduction can basically retain the original morphology, meanwhile, the change of physico-chemical properties on the surface endow excellent adsorption capaities of 26.10 mg g-1 for Pb2+ and 67.55 mg g-1 for atrazine. A significant difference is in sorption of Pb2+ and atrazine on RGO-BC sample in both single- and binary-solute systems. The adsorption capacity of RGO-BC still remained above 54.58 mg g-1 after four times regeneration (81% adsorption capacity remained), demonstrating a promising candidate for the application of removal contaminant in the environment.

  8. Green synthesis of Pd nanoparticles at Apricot kernel shell substrate using Salvia hydrangea extract: Catalytic activity for reduction of organic dyes.

    PubMed

    Khodadadi, Bahar; Bordbar, Maryam; Nasrollahzadeh, Mahmoud

    2017-03-15

    For the first time the extract of the plant of Salvia hydrangea was used to green synthesis of Pd nanoparticles (NPs) supported on Apricot kernel shell as an environmentally benign support. The Pd NPs/Apricot kernel shell as an effective catalyst was prepared through reduction of Pd 2+ ions using Salvia hydrangea extract as the reducing and capping agent and Pd NPs immobilization on Apricot kernel shell surface in the absence of any stabilizer or surfactant. According to FT-IR analysis, the hydroxyl groups of phenolics in Salvia hydrangea extract as bioreductant agents are directly responsible for the reduction of Pd 2+ ions and formation of Pd NPs. The as-prepared catalyst was characterized by Fourier transform infrared (FT-IR) and UV-Vis spectroscopy, field emission scanning electron microscopy (FESEM) equipped with an energy dispersive X-ray spectroscopy (EDS), Elemental mapping, X-ray diffraction analysis (XRD) and transmittance electron microscopy (TEM). The synthesized catalyst was used in the reduction of 4-nitrophenol (4-NP), Methyl Orange (MO), Methylene Blue (MB), Rhodamine B (RhB), and Congo Red (CR) at room temperature. The Pd NPs/Apricot kernel shell showed excellent catalytic activity in the reduction of these organic dyes. In addition, it was found that Pd NPs/Apricot kernel shell can be recovered and reused several times without significant loss of catalytic activity. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Human urotensin-II is a potent spasmogen of primate airway smooth muscle

    PubMed Central

    Hay, Douglas W P; Luttmann, Mark A; Douglas, Stephen A

    2000-01-01

    The contractile profile of human urotensin-II (hU-II) was examined in primate airway and pulmonary vascular tissues. hU-II contracted tissues from different airway regions with similar potencies (pD2s from 8.6 to 9.2). However, there were regional differences in the efficacy of hU-II, with a progressive increase in the maximum contraction from trachea to smaller airway regions (from 9 to 41% of the contraction to 10 μM carbachol). hU-II potently contracted pulmonary artery tissues from different regions with similar potencies and efficacies: pD2s=8.7 to 9.3 and maximal contractions=79 to 86% of 60 mM KCl. hU-II potently contracted pulmonary vein preparations taken proximal to the atria, but had no effect in tissues from distal to the atria. This is the first report describing the contractile activity of hU-II in airways and suggests that the potential pathophysiological role of this peptide in lung diseases warrants investigation. PMID:10960062

  10. "Un-annealed and Annealed Pd Ultra-Thin Film on SiC Characterized by Scanning Probe Microscopy and X-ray Photoelectron Spectroscopy"

    NASA Technical Reports Server (NTRS)

    Lu, W. J.; Shi, D. T.; Elshot, K.; Bryant, E.; Lafate, K.; Chen, H.; Burger, A.; Collins, W. E.

    1998-01-01

    Pd/SiC has been used as a hydrogen and a hydrocarbon gas sensor operated at high temperature. UHV (Ultra High Vacuum)-Scanning Tunneling Microscopy (STM), Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS) techniques were applied to study the relationship between the morphology and chemical compositions for Pd ultra-thin films on SiC (less than 30 angstroms) at different annealing temperatures. Pd ultra-thin film on 6H-SiC was prepared by the RF sputtering method. The morphology from UHV-STM and AFM shows that the Pd thin film was well deposited on SiC substrate, and the Pd was partially aggregated to round shaped participates at an annealing temperature of 300 C. At 400 C, the amount of surface participates decreases, and some strap shape participates appear. From XPS, Pd2Si was formed on the surface after annealing at 300 C, and all Pd reacted with SiC to form Pd2Si after annealing at 400 C. The intensity of the XPS Pd peak decreases enormously at 400 C. The Pd film diffused into SiC, and the Schottky barrier height has almost no changes. The work shows the Pd sicilides/SiC have the same electronic properties with Pd/SiC, and explains why the Pd/SiC sensor still responds to hydrogen at high operating temperatures.

  11. The study of structures and properties of PdnHm(n=1-10, m=1,2) clusters by density functional theory

    NASA Astrophysics Data System (ADS)

    Wen, Jun-Qing; Chen, Guo-Xiang; Zhang, Jian-Min; Wu, Hua

    2018-04-01

    The geometrical evolution, local relative stability, magnetism and charge transfer characteristics of PdnHm(n = 1-10, m = 1,2) have been systematically calculated by using density functional theory. The studied results show that the most stable geometries of PdnH and PdnH2 (n = 1-10) can be got by doping one or two H atoms on the sides of Pdn clusters except Pd6H and Pd6H2. It is found that doping one or two H atoms on Pdn clusters cannot change the basic framework of Pdn. The analysis of stability shows that Pd2H, Pd4H, Pd7H, Pd2H2, Pd4H2 and Pd7H2 clusters have higher local relative stability than neighboring clusters. The analysis of magnetic properties demonstrates that absorption of hydrogen atoms decreases the average atomic magnetic moments compared with pure Pdn clusters. More charges transfer from H atoms to Pd atoms for Pd6H and Pd6H2 clusters, demonstrating the adsorption of hydrogen atoms change from side adsorption to surface adsorption.

  12. Single and couple doping ZnO nanocrystals characterized by positron techniques

    NASA Astrophysics Data System (ADS)

    Pasang, Tenzin; Namratha, Keerthiraj; Guagliardo, Paul; Byrappa, Kullaiah; Ranganathaiah, Chikkakuntappa; Samarin, S.; Williams, J. F.

    2015-04-01

    Zinc oxide (ZnO) nanocrystals have been synthesized using a mild hydrothermal process using low temperatures and pressures with the advantages of free growth catalyst, low cost and alternative technology. Positron annihilation lifetime spectroscopy and coincidence Doppler broadening (CDB) spectroscopic methods have been used to investigate the roles of single- and co-dopants and native defects of the ZnO nanocrystals controlled by the synthesis process. It is shown that single Ag1+ and Pd2+ dopants occupy interstitial sites of the ZnO lattice and single Ru3+ doping replaces Zn vacancies substitutionally with a significant effect on the CDB momentum ratio curves when compared using ZnO as the reference spectrum. The co-doping of the ZnO lattice with (Sn4+ + Co2+) shows similar CDB ratios as Ru3+ single-doping. Also co-doping with (Ag1+ + Pd2+) or (Ag1+ + W6+) shows significant decreases in the band gap energy up to about 12.6% compared to single doping. The momentum ratio curves, referenced to undoped ZnO, indicate dopants in interstitial and substitutional sites. The presence of transition metal ions interstitially will trap electrons which resist the recombination of electrons and in turn affect the conductivity of the material.

  13. Hexamethonium sensitivity of the swim musculature of the pteropod mollusc, Clione limacina.

    PubMed

    Satterlie, Richard A; Courtney, Christopher

    2008-12-01

    Swimming in reduced electrophysiological preparations of the pteropod mollusc, Clione limacina, was blocked by bath application of hexamethonium even though pattern generator activity continued with this treatment. Neuromuscular recordings indicated that hexamethonium blocked synaptic input from Pd-3 and Pd-4 motoneurons to slow-twitch muscle cells, while connections from Pd-1A and Pd-2A motoneurons to fast-twitch muscle cells were variable in their response to hexamethonium-synaptic inputs were suppressed in most cases and occasionally blocked, but the latter only with high concentrations and long incubations. Acutely dissociated wing muscle cells showed a concentration-dependency in the percentage of contracted cells with bath application of acetylcholine, and this contractile activity was blocked in preparations that were first bathed in hexamethonium. Intracellular recordings from dissociated slow-twitch muscle cells showed conductance-increase depolarizations of approximately 20 mV following 1 s pressure ejections of 10(-4) M acetylcholine from micropipettes placed immediately adjacent to the muscle cells. These responses were blocked when hexamethonium was bath applied prior to the pressure-applied acetylcholine. The results suggest the Pd-3/Pd-4 motoneuron to slow-twitch muscle cell junctions are cholinergic with nicotinic-like receptors, while the Pd-1A/Pd-2A to fast-twitch muscle cell connections are likely cholinergic, but with a different receptor type.

  14. Dzyaloshinskii-Moriya interaction and magnetic anisotropies in Uranium compounds

    NASA Astrophysics Data System (ADS)

    Sandratskii, L. M.

    2018-05-01

    We report on the first-principles study of complex noncollinear magnetic structures in Uranium compounds. We contrast two cases. The first is the periodic magnetic structure of U2Pd2In with exactly orthogonal atomic moments, the second is an incommensurate plane spiral structure of UPtGe where the angle between atomic moments of nearest neighbors is also close to 90°. We demonstrate that the hierarchy of magnetic interactions leading to the formation of the magnetic structure is opposite in the two cases. In U2Pd2In, the magnetic anisotropy plays the leading role, followed by the Dzyaloshinskii-Moriya interaction (DMI) interaction specifying the chirality of the structure. Here, the interatomic exchange interaction does not play important role. In UPtGe the hierarchy of the interactions is opposite. The leading interaction is the interatomic exchange interaction responsible for the formation of the incommensurate spiral structure followed by the DMI responsible for the selected chirality of the helix. The magnetic anisotropy is very weak that is a prerequisite for keeping the distortion of the helical structure weak.

  15. Surface-Functionalized Electrospun Titania Nanofibers for the Scavenging and Recycling of Precious Metal Ions.

    PubMed

    Dai, Yunqian; Formo, Eric; Li, Haoxuan; Xue, Jiajia; Xia, Younan

    2016-10-20

    Precious metals are widely used as catalysts in industry. It is of critical importance to keep the precious metal ions leached from catalysts at a level below one part per million (ppm) in the final products and to recycle the expensive precious metals. Here we demonstrate a simple and effective method for scavenging precious metal ions from an aqueous solution and thereby reduce their concentrations down to the parts per billion (ppb) level. The key component is a filtration membrane comprised of titania (TiO 2 ) nanofibers whose surface has been functionalized with a silane bearing amino or thiol group. When operated under continuous flow at a rate of 1 mL min -1 and at room temperature, up to 99.95 % of the Pd 2+ ions could be removed from a stock solution with an initial concentration of 100 ppm. This work offers a viable strategy not only for the removal of precious metal ions but also for recovering and further recycling them for use as catalysts. For example, the captured Pd 2+ ions could be converted to nanoparticles and used as catalysts for organic reactions such as Suzuki coupling in a continuous flow reactor. This system can be potentially applied to pharmaceutical industry and waste stream treatment. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Effects of metal ions on the reactivity and corrosion electrochemistry of Fe/FeS nanoparticles.

    PubMed

    Kim, Eun-Ju; Kim, Jae-Hwan; Chang, Yoon-Seok; Turcio-Ortega, David; Tratnyek, Paul G

    2014-04-01

    Nano-zerovalent iron (nZVI) formed under sulfidic conditions results in a biphasic material (Fe/FeS) that reduces trichloroethene (TCE) more rapidly than nZVI associated only with iron oxides (Fe/FeO). Exposing Fe/FeS to dissolved metals (Pd(2+), Cu(2+), Ni(2+), Co(2+), and Mn(2+)) results in their sequestration by coprecipitation as dopants into FeS and FeO and/or by electroless precipitation as zerovalent metals that are hydrogenation catalysts. Using TCE reduction rates to probe the effect of metal amendments on the reactivity of Fe/FeS, it was found that Mn(2+) and Cu(2+) decreased TCE reduction rates, while Pd(2+), Co(2+), and Ni(2+) increased them. Electrochemical characterization of metal-amended Fe/FeS showed that aging caused passivation by growth of FeO and FeS phases and poisoning of catalytic metal deposits by sulfide. Correlation of rate constants for TCE reduction (kobs) with electrochemical parameters (corrosion potentials and currents, Tafel slopes, and polarization resistance) and descriptors of hydrogen activation by metals (exchange current density for hydrogen reduction and enthalpy of solution into metals) showed the controlling process changed with aging. For fresh Fe/FeS, kobs was best described by the exchange current density for activation of hydrogen, whereas kobs for aged Fe/FeS correlated with electrochemical descriptors of electron transfer.

  17. Two Novel Dermaseptin-Like Antimicrobial Peptides with Anticancer Activities from the Skin Secretion of Pachymedusa dacnicolor.

    PubMed

    Shi, Daning; Hou, Xiaojuan; Wang, Lei; Gao, Yitian; Wu, Di; Xi, Xinping; Zhou, Mei; Kwok, Hang Fai; Duan, Jinao; Chen, Tianbao; Shaw, Chris

    2016-05-12

    The dermaseptin antimicrobial peptide family contains members of 27-34 amino acids in length that have been predominantly isolated from the skins/skin secretions of phyllomedusine leaf frogs. By use of a degenerate primer in Rapid amplification of cDNA ends (RACE) PCR designed to a common conserved domain within the 5'-untranslated regions of previously-characterized dermaseptin encoding cDNAs, two novel members of this peptide family, named dermaseptin-PD-1 and dermaseptin-PD-2, were identified in the skin secretion of the phyllomedusine frog, Pachymedusa dacnicolor. The primary structures of both peptides were predicted from cloned cDNAs, as well as being confirmed by mass spectral analysis of crude skin secretion fractions resulted from reversed-phase high-performance liquid chromatography. Chemically-synthesized replicates of dermaseptin-PD-1 and dermaseptin-PD-2 were investigated for antimicrobial activity using standard model microorganisms (Gram-positive bacteria, Gram-negative bacteria and a yeast) and for cytotoxicity using mammalian red blood cells. The possibility of synergistic effects between the two peptides and their anti-cancer cell proliferation activities were assessed. The peptides exhibited moderate to high inhibition against the growth of the tested microorganisms and cancer cell lines with low haemolytic activity. Synergistic interaction between the two peptides in inhibiting the proliferation of Escherichia coli and human neuronal glioblastoma cell line, U251MG was also manifested.

  18. A receptor-G protein coupling-independent step in the internalization of the thyrotropin-releasing hormone receptor.

    PubMed

    Petrou, C; Chen, L; Tashjian, A H

    1997-01-24

    To determine whether functional receptor-G protein coupling or signaling are required for internalization of the thyrotropin-releasing hormone receptor (TRHR), we compared the endocytosis of Gq-coupled and uncoupled receptors. A hemagglutinin epitope-tagged TRHR (HA-TRHR) was in the Gq-coupled state when bound to the agonist, MeTRH, and in a nonsignaling state when bound to the HA antibody (12CA5). 12CA5 did not induce an increase in [Ca2+]i or inositol phosphates and did not inhibit [3H]MeTRH binding or MeTRH-induced production of second messengers. Both agonist- and antibody-bound HA-TRHRs were rapidly internalized via the same pathway; internalization was sensitive to hypertonic shock, and both types of internalized receptors were sorted into lysosomes. In addition, the amino acid sequence CNC (positions 335-337) in the C-terminal tail of the TRHR, which is important in ligand-induced receptor internalization as determined by deletion mutagenesis (Nussenzveig, D. R., Heinflink, M., and Gershengorn, M. C. (1993) J. Biol. Chem. 268, 2389-2392), was also important for 12CA5-induced internalization. We expressed two truncated receptors, HA-K338STOP and HA-C335STOP, in GH12C1 pituitary cells. Both HA-TRHR and HA-K338STOP were localized at the plasma membrane of untreated cells and were translocated to intracellular vesicles after MeTRH or 12CA5 binding; however, HA-C335STOP was internalized and recycled constitutively. The intracellular localization of HA-C335STOP was not altered by MeTRH; however, 12CA5 binding induced the disappearance of internalized HA-C335STOP and caused its localization at the plasma membrane, indicating that constitutively cycling HA-C335STOP cannot be reinternalized after antibody binding. Thus, amino acids 335-337, which are important for the internalization of Gq-coupled TRHRs, are also required for the sequestration of functionally uncoupled TRHRs, and in addition, they act as an inhibitory signal that prevents constitutive receptor

  19. Role of EDHF in the vasodilatory effect of loop diuretics in guinea-pig mesenteric resistance arteries

    PubMed Central

    Pourageaud, Fabrice; Bappel-Gozalbes, Catherine; Marthan, Roger; Freslon, Jean-Louis

    2000-01-01

    Relaxing effect of loop diuretics, piretanide and furosemide in comparison with acetylcholine (ACh) was investigated in guinea-pig isolated mesenteric resistance arteries. Concentration-response curves to ACh (0.001–10 μM) and diuretics (0.0001–1 μM) were constructed in noradrenaline (10–30 μM)-precontracted arteries incubated either in normal physiological salt solution (PSS) or in 30 mM KCl PSS (K-PSS). In PSS, maximal relaxations (Rmax) and pD2 to ACh were 87±2% and 7.1±0.1 (n=10). L-NG-nitro-arginine methyl ester (L-NAME, 100 μM) reduced Rmax by 20% (P<0.01, n=7) and pD2 by 10% (P<0.01). In contrast, indomethacin (10 μM) increased Rmax by 19% (P<0.01, n=8) and pD2 by 10% (P<0.05). Combination of L-NAME+indomethacin reversed the effect observed with either of these inhibitors used alone. In K-PSS, Rmax was attenuated by 40% (P<0.001, n=6) compared to PSS. L-NAME reduced Rmax by 65% (P<0.01, n=5) and increased pD2 by 15 fold. L-NAME+indomethacin suppressed the resistant relaxation. In PSS+L-NAME+indomethacin, inhibitors of small (SKCa; apamin, 0.1 μM) and large (BKCa; iberiotoxin and charybdotoxin, 0.1 μM) conductance Ca2+-sensitive K−-channels used alone had little effect on the ACh-response. Combination of apamin+iberiotoxin reduced Rmax by 40% (P<0.05, n=7) while apamin+charybdotoxin fully abolished the resistant relaxation. In PSS, piretanide and furosemide induced relaxation with Rmax: 89±3% vs 84±5% and pD2: 8.5±0.1 vs 7.7±0.2 (P<0.01) for piretanide (n=11) and furosemide (n=10), respectively. Endothelial abrasion suppressed relaxation to diuretics. L-NAME and indomethacin used alone or in combination did not significantly modify the response to diuretics. In K-PSS, piretanide-induced relaxation was abolished whereas that to furosemide was reduced by 70% (P<0.001, n=9) compared to PSS and was suppressed by L-NAME+indomethacin. In PSS+L-NAME+indomethacin, apamin slightly reduced relaxation to diuretics whereas charybdotoxin or iberiotoxin abolished the response. These results indicate that ACh-evoked relaxation is mediated by both NO/PGl2-dependent and -independent mechanisms. The EDHF-dependent component relies on activation of Ca2+-activated K+ channels, is sensitive to a combination of apamin+charybdotoxin and to a smaller degree to a combination of apamin+iberiotoxin. Loop diuretic-induced relaxation is endothelium-dependent, appears to be mediated by NO, PGl2 and EDHF for furosemide and EDHF only for piretanide. For the two diuretics, opening of BKCa channels may be involved in the relaxation. PMID:11082130

  20. Metallosulfoxides and -sulfones: Sulfur oxygenates of [1,5-Bis(2-mercaptoethyl)-1,5-diazacyclooctanato]palladium (II)

    SciTech Connect

    Tuntulani, T.; Musie, G.; Reibenspies, J.H.

    1995-12-06

    Successive sulfur-site oxygenation of the dithiolate complex [1,5-bis(mercaptoethyl)-1,5 diazacyclooctanato]-palladium(II), Pd-1, using H{sub 2}O{sub 2} as an O atom source produced all but one member of the series of palladium(II) complexes containing sulfinate (metallosulfone) and sulfinate (metallosulfoxide) S-donor ligands: the monosulfoxide, PdS(=O)R or Pd-4; bis(sulfoxide), Pd(S(=O)R){sub 2} or Pd-5; sulfone/sulfoxide, Pd((SO{sub 2}R)S(=))R or Pd-6; and the bis(sulfone) Pd(SO{sub 2}R){sub 2} or Pd-3 complex. A unique site selectivity for the addition of a second O atom from H{sub 2}O{sub 2} to thiolate sulfur of Pd-4 producing the bis(sulfoxide), Pd-5, exclusively, precluded the preparation of the monosulfone complex, Pd(SO{sub 2}R)SR or Pd-2, viamore » that route. However, the dithiolate Pd-1 reacts with O{sub 2} photochemically in aprotic solvents, giving access to this last member of the series, Pd-2. Further reaction of Pd-2 with O{sub 2} under UV photolysis gives the bis(sulfone) complex, Pd-3. The oxygenates were characterized by various spectroscopies, electrochemistry, and X-ray crystallography. Mass spectrometry delineated a single O atom loss pathway for the sulfoxide species, while SO{sub 2} and O{sub 2} loss is found in sulfone cases. Electrochemical studies show that the addition of an O atom to a thiolate sulfur to create a sulfoxide S-donor results in a stabilization of the Pd{sup I} oxidation state in the range 50-70 mV, while the addition of an O atom to a sulfoxide sulfur to create a sulfone S-donor results in greater stabilization of the Pd{sup I} oxidation state in the range 190-220 mV.« less

  1. New dinuclear palladium(II) complexes: Studies of the nucleophilic substitution reactions, DNA/BSA interactions and cytotoxic activity.

    PubMed

    Ćoćić, Dušan; Jovanović, Snežana; Nišavić, Marija; Baskić, Dejan; Todorović, Danijela; Popović, Suzana; Bugarčić, Živadin D; Petrović, Biljana

    2017-10-01

    Six new dinuclear Pd(II) complexes, [{Pd(2,2'-bipy)Cl} 2 (μ-pz)](ClO 4 ) 2 (Pd1), [{Pd(dach)Cl} 2 (μ-pz)](ClO 4 ) 2 (Pd2), [{Pd(en)Cl} 2 (μ-pz)](ClO 4 ) 2 (Pd3), [{Pd(2,2'-bipy)Cl} 2 (μ-4,4'-bipy)](ClO 4 ) 2 (Pd4), [{Pd(dach)Cl} 2 (μ-4,4'-bipy)](ClO 4 ) 2 (Pd5) and [{Pd(en)Cl} 2 (μ-4,4'-bipy)](ClO 4 ) 2 (Pd6) (where 2,2'-bipy=2,2'-bipyridyl, pz=pyrazine, dach=trans-(±)-1,2-diaminocyclohexane, en=ethylenediamine, 4,4'-bipy=4,4'-bipyridyl) have been synthesized and characterized by elemental microanalysis, IR, 1 H NMR and MALDI-TOF mass spectrometry. The pK a values of corresponding diaqua complexes were determined by spectrophotometric pH titration. Substitution reactions with thiourea (Tu), l-methionine (l-Met), l-cysteine (l-Cys), l-histidine (l-His) and guanosine-5'-monophosphate (5'-GMP) were studied under the pseudo-first order conditions at pH7.2. Reactions of Pd1 with Tu, l-Met and l-Cys were followed by decomposition of complexes, while structures of dinuclear complexes were preserved during the substitution with nitrogen donors. Interactions with calf-thymus DNA (CT-DNA) were followed by absorption spectroscopy and fluorescence quenching measurements. All complexes can bind to CT-DNA exhibiting high intrinsic binding constants (K b =10 4 -10 5 M -1 ). Competitive studies with ethidium bromide (EB) have shown that complexes can displace DNA-bound EB. High values of binding constants towards bovine serum albumin protein (BSA) indicate good binding affinity. Finally, all complexes showed moderate to high cytotoxic activity against HeLa (human cervical epithelial carcinoma cell lines) and MDA-MB-231 (human breast epithelial carcinoma cell lines) tumor cell lines inducing apoptotic type cell death, whereas normal fibroblasts were significantly less sensitive. The impact on cell cycle of these cells was distinctive, where Pd4, Pd5 and Pd6 showed the most prominent effect arresting MDA-MB-231 (human lung fibroblast cell lines) cell in G1/S phase of cell

  2. Effect of processing temperature on the properties of Fe-Hydroxyapatite

    NASA Astrophysics Data System (ADS)

    Kathriarachchi, Vindu; Leventouri, Theodora; Rondinone, Adam; Sorge, Korey

    2015-03-01

    Multi-substituted Hydroxyapatite (HAp), Ca5(PO4)3OH, is the main mineral phase in physiological apatite. Fe is a minor substitution element in bone and enamel substituting Ca in the HAp structure. Crystal structure, magnetic and microstructure properties of Ca5-xFex(PO4)3OH depend on processing parameters. We present results from our research on the Ca5-xFex(PO4)3OH system (x = 0.0, 0.05, 0.1, 0.2 and 0.3) prepared at 37° C, and 80° C. Hydroxyapatite single-phase was detected for x <0.1 in both sets of samples, while hematite and/or maghemite develops starting at x = 0.1. Rietveld refinements of XRD and NPD patterns show that the a and c lattice constants decrease with increasing Fe concentration for both sets of samples. Pure HAp is diamagnetic but as x increases, Fe-HAp transitions from paramagnetic to weak ferromagnetic behavior. TEM images show spherical particles in samples prepared at 37° C, and elongated particles in samples prepared at 80° C. XRF studies confirm the iron substitution and show that the Ca/P stoichiometric ratio of 1.67 decreases with increasing the Fe concentration. Further, the Fe/Ca +Fe atomic ratios of samples prepared at 37° C are greater than those prepared at 80° C. TEM and XRF data were collected at the Center for Nanophase Materials Sciences which is a DOE Office of Science User Facility. NPD data were collected at the SNS of the ORNL.

  3. Physiological and Therapeutic Vascular Remodeling Mediated by Hypoxia-Inducible Factor 1

    NASA Astrophysics Data System (ADS)

    Sarkar, Kakali; Semenza, Gregg L.

    Angiogenesis along with arteriogenesis and vasculogenesis is a fundamental process in ischemic repair in adult animals including humans. Hypoxia-inducible factor 1 (HIF-1) plays a central role in mediating adaptive responses to hypoxia/ischemia by expressing angiogenic cytokines/growth factors and their cognate receptors. Angiogenic growth factors are the homing signal for circulating angiogenic cells (CACs), which are mobilized to peripheral blood from bone marrow, recruited to target tissues, and promote vascularization. Impairment of HIF-1-mediated gene transcription contributes to the impaired vascular responses in peripheral vascular disease that are associated with aging and diabetes. Promoting neovascularization in ischemic tissues is a promising strategy for the treatment of peripheral vascular disease when surgical or catheter-based revascularization is not possible. Intramuscular injection of an adenovirus encoding a constitutively active form of HIF-1α (AdCA5), into the ischemic limb of diabetic mice increases the recovery of limb perfusion and function, rescues the diabetes-associated impairment of CACs, and increases vascularization. Administration of AdCA5 overcomes the effect of aging on recovery of blood flow in middle-aged mice following femoral artery ligation in a mouse model of age-dependent critical limb ischemia. Intramuscular injection of AdCA5 along with intravenous injection of bone-marrow-derived angiogenic cells cultured in the presence of prolyl-4-hydroxylase inhibitor dimethyloxalylglycine, increases blood flow and limb salvage in old mice following femoral artery ligation. HIF-1α gene therapy increases homing of bone-marrow-derived cells, whereas induction of HIF-1 in these cells increases their retention in the ischemic tissue by increasing their adhesion to endothelium leading to synergistic effects of combined therapy on improving blood flow.

  4. Age-dependent Impairment of HIF-1α̣Expression in Diabetic Mice: Correction with Electroporation-facilitated Gene Therapy Increases Wound Healing, Angiogenesis, and Circulating Angiogenic Cells

    PubMed Central

    Liu, Lixin; Marti, Guy P.; Wei, Xiaofei; Zhang, Xianjie; Zhang, Huafeng; Liu, Ye V.; Nastai, Manuel; Semenza, Gregg L.; Harmon, John W.

    2009-01-01

    Wound healing is impaired in elderly patients with diabetes mellitus. We hypothesized that age-dependent impairment of cutaneous wound healing in db/db diabetic mice: (a) would correlate with reduced expression of the transcription factor hypoxia-inducible factor 1α (HIF-1α) as well as its downstream target genes; and (b) could be overcome by HIF-1α replacement therapy. Wound closure, angiogenesis, and mRNA expression in excisional skin wounds were analyzed and circulating angiogenic cells were quantified in db/db mice that were untreated or received electroporation-facilitated HIF-1α gene therapy. HIF-1α mRNA levels in wound tissue were significantly reduced in older (4–6 months) as compared to younger (1.5–2 months) db/db mice. Expression of mRNAs encoding the angiogenic cytokines vascular endothelial growth factor (VEGF), angiopoietin 1 (ANGPT1), ANGPT2, platelet derived growth factor B (PDGF-B), and placental growth factor (PLGF) was also impaired in wounds of older db/db mice. Intradermal injection of plasmid gWIZ-CA5, which encodes a constitutively active form of HIF-1α, followed by electroporation, induced increased levels of HIF-1α mRNA at the injection site on day 3 and increased levels of VEGF, PLGF, PDGF-B, and ANGPT2 mRNA on day 7. Circulating angiogenic cells in peripheral blood increased 10-fold in mice treated with gWIZ-CA5. Wound closure was significantly accelerated in db/db mice treated with gWIZ-CA5 as compared to mice treated with empty vector. Thus, HIF-1α gene therapy corrects the age-dependent impairment of HIF-1α expression, angiogenic cytokine expression, and circulating angiogenic cells that contribute to the age-dependent impairment of wound healing in db/db mice. PMID:18506785

  5. Synthesis of the Tube Silicate Litidionite and Structural Relationships between It and Some Other Silicates.

    DTIC Science & Technology

    1982-02-17

    CuSi4015 Others are agrellite, NaCa2Si4O0oF, 1 6 narsarsukite, Na2TiSi4O 1 7 miserite, KCa5 i2 07 Si601 5 (OH)F,18 and probably canasite , Na4K2Ca 5...and canasite are rare. Litidionite is apparently very rare, the only reported occurrence of it being in the crater of Mt. Vesuvius. Both litidionite1...narsarsukite, miserite, and probably canasite contain, like 13-19 lititionite, tube silicate ions. The first three contain ions that are the same as that in

  6. The conformation of the monomethyl ethers of methyl beta-lactoside in D2O and Me2SO-d6 solutions.

    PubMed

    Fernández, P; Jiménez-Barbero, J

    1993-10-04

    The solution conformations of all the possible monomethyl ethers of methyl beta-lactoside have been analysed using molecular mechanics and dynamics calculations and nuclear magnetic resonance data (variable temperature and NOE experiments). The overall shape of all the compounds studied is fairly similar and may be described by conformers included in a low-energy region with phi = -100 +/- 40 degrees and psi = -135 +/- 35 degrees, which is ca. 5% of the total potential energy surface for the glycosidic linkages of the disaccharides.

  7. Optical, Biochemical, and Molecular Characterization of New Bioluminescence Systems

    DTIC Science & Technology

    2007-05-09

    5cym 5 * Hutioti Annid Polythasta SprinostunthstinosjtnImons + mouth Sou Annelid. - Polyoheete Stats W.nm ++ Itnoen + At 493-5946 616 -664 - 719...biranhunnsi + lhite) +7 mouth fl o Coýi~ca-5eat:m’ptda: - Limpet Ceguthtn. oneuista A Isnoon/blatcl, + Plate ot manatle 572 616-664- 719 Coisc- "tnpda...as an aposematic signal upon toads (Bufo bufo). Behav. 3! Ecol. 2003; 14: 103-108. 6. Baker, CH. Dipterian glow-worms: marvelous maggots weave magic

  8. Functional Roles of the Non-Catalytic Calcium-Binding Sites in the N-Terminal Domain of Human Peptidylarginine Deiminase 4

    PubMed Central

    Liu, Yi-Liang; Tsai, I-Chen; Chang, Chia-Wei; Liao, Ya-Fan; Liu, Guang-Yaw; Hung, Hui-Chih

    2013-01-01

    This study investigated the functional roles of the N-terminal Ca2+ ion-binding sites, in terms of enzyme catalysis and stability, of peptidylarginine deiminase 4 (PAD4). Amino acid residues located in the N-terminal Ca2+-binding site of PAD4 were mutated to disrupt the binding of Ca2+ ions. Kinetic data suggest that Asp155, Asp157 and Asp179, which directly coordinate Ca3 and Ca4, are essential for catalysis in PAD4. For D155A, D157A and D179A, the k cat/K m,BAEE values were 0.02, 0.63 and 0.01 s−1mM−1 (20.8 s−1mM−1 for WT), respectively. Asn153 and Asp176 are directly coordinated with Ca3 and indirectly coordinated with Ca5 via a water molecule. However, N153A displayed low enzymatic activity with a k cat value of 0.3 s−1 (13.3 s−1 for wild-type), whereas D176A retained some catalytic power with a k cat of 9.7 s−1. Asp168 is the direct ligand for Ca5, and Ca5 coordination by Glu252 is mediated by two water molecules. However, mutation of these two residues to Ala did not cause a reduction in the k cat/K m,BAEE values, which indicates that the binding of Ca5 may not be required for PAD4 enzymatic activity. The possible conformational changes of these PAD4 mutants were examined. Thermal stability analysis of the PAD4 mutants in the absence or presence of Ca2+ indicated that the conformational stability of the enzyme is highly dependent on Ca2+ ions. In addition, the results of urea-induced denaturation for the N153, D155, D157 and D179 series mutants further suggest that the binding of Ca2+ ions in the N-terminal Ca2+-binding site stabilizes the overall conformational stability of PAD4. Therefore, our data strongly suggest that the N-terminal Ca2+ ions play critical roles in the full activation of the PAD4 enzyme. PMID:23382808

  9. Dual Energy X-Ray Densitometry Apparatus and Method Using Single X-Ray Pulse

    DTIC Science & Technology

    1999-10-13

    future bone fracture risk. Bone mineral loss is associated with aging and is more rapid in post-menopausal women. In addition, bone mineral loss is... parameters of the x-ray tube of Figures 1 and 2 illustrating, respectively, the calculated current, voltage and power; and Figures 4(a) and 4(d) are...assumed to be that of water. The bone mineral is hydroxyapatite (Ca5P30i3H) with an assumed density of 0.25 g/cm3 based on the lumbar vertebra metrology

  10. Theory-Driven Models for Correcting Fight or Flight Imbalance in Gulf War Illness

    DTIC Science & Technology

    2012-09-01

    contained in this report are those of the author( s ) and should not be construed as an official Department of the Army position, policy or decision unless...for Correcting “Fight or Flight” Imbalance in Gulf War Illness 5b. GRANT NUMBER W81XWH-10-1-0774 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d...PROJECT NUMBER Gordon Broderick, P.hD. 5e. TASK NUMBER Email: gordon.broderick@ualberta.ca 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME( S

  11. Historic Properties Report. Sunflower Army Ammunition Plant, Desoto, Kansas.

    DTIC Science & Technology

    1984-08-01

    the plant produced amonium nitrate liquor for two years before entering "standby" status. The SFAAP was rehabilitated and reactivated in 1951 for... D -A175 882 HISTORIC PROPERTIES REPORT SUNFLOWER RMY AMUNITION ±,𔃻 PLANT DESOTO KANSAS(U) BUILDING TECHNOLOGY INC SILVER UNCR7SIFEDSPRING ND R...33.6 I..11111 120 11111 II L - i.E ~L.. 111111.25 flfflI4 fl 16 t’Ca.. .5 ’C ’C ’C ’C a. ’a ’I B-J 4 S ’a 4 N t C,. ’C di. ’aI. .5 a .* d

  12. GIXAFS study of Fe3+ sorption and precipitation on natural quartz surfaces

    USGS Publications Warehouse

    Waychunas, G.; Davis, J.; Reitmeyer, R.

    1999-01-01

    Grazing-incidence EXAFS has been used to characterize the structure of Fe3+ sorbed onto natural single crystal quartz surfaces. Fe3+ sorption at ca. 5% monolayer coverage on a natural crystal allowed to equilibrate in air resulted in formation of hematite nuclei with strong texturing on r-and m-planes. EXAFS calculations suggests that both O and Fe backscattering is necessary to yield acceptable structural models, that about 50% of the sorbed iron resides in nuclei, and that the approximate dimensions of the nuclei can be estimated via Feff 7.0 calculations of various nuclei sizes and shapes.

  13. Rapid step-gradient purification of mitochondrial DNA.

    PubMed

    Welter, C; Meese, E; Blin, N

    1988-01-01

    A convenient modification of the step gradient (CsCl/ethidium bomide) procedure is described. This rapid method allows isolation of covalently closed circular DNA separated from contaminating proteins, RNA and chromosomal DNA in ca. 5 h. Large scale preparations can be performed for circular DNA from eukaryotic organelles (mitochondria). The protocol uses organelle pelleting/NaCl-sarcosyl incubation steps for mitochondria followed by a CsCl step gradient and exhibits yields equal to the conventional procedures. It results in DNA sufficiently pure to be used for restriction endonuclease analysis, subcloning, 5'-end labeling, gel retention assays, and various types of hybridization.

  14. Small-Gap Flows

    DTIC Science & Technology

    1984-04-01

    I TV N 4 NAVAL ARCIETUR & OFFSHORE ENGINEERING SMALL- GAP FLOWSti E 0.TUCK01 REPORT NO- M!AOL 34-1 CONTRACT NJU1-𔃾-K-0026 APRIL 1984 let.? UNIVERSMn...34’OF CALIFORNIA# BERKELEY, CA 5.1720 ft (45 642-141 SMALL- GAP FLOWS BY E. 0. TUCK REPORT No. NAUE 84-1 CONTRACT N00014-84-K-OU26 APRIL i984...34small- gap " theme.Chapters 1-4 were originally presented in the form of a lecture series in the Department of Naval Architecture and Offshore

  15. Can conservation agriculture reduce the impact of soil erosion in northern Tunisia ?

    NASA Astrophysics Data System (ADS)

    Bahri, Haithem; Annabi, Mohamed; Chibani, Roukaya; Cheick M'Hamed, Hatem; Hermessi, Taoufik

    2016-04-01

    Mediterranean countries are prone to soil erosion, therefore Tunisia, with Mediterranean climate, is threatened by water erosion phenomena. In fact, 3 million ha of land is threatened by erosion, and 50% is seriously affected. Soils under conservation agriculture (CA) have high water infiltration capacities reducing significantly surface runoff and thus soil erosion. This improves the quality of surface water, reduces pollution from soil erosion, and enhances groundwater resources. CA is characterized by three interlinked principles, namely continuous minimum mechanical soil disturbance, permanent organic soil cover and diversification of crop species grown in sequence or associations. Soil aggregate stability was used as an indicator of soil susceptibility to water erosion. Since 1999, In Tunisia CA has been introduced in rainfed cereal areas in order to move towards more sustainable agricultural systems. CA areas increased from 52 ha in 1999 to 15000 ha in 2015. The objective of this paper is to study the effect of CA on soil erosion in northern Tunisia. Soil samples were collected at 10 cm of depth from 6 farmers' fields in northern Tunisia. Conventional tillage (CT), CA during less than 5 years (CA<5 years) and CA during more than 5 years (CA>5 years) have been practiced in each farmers field experiment of wheat crop. Soil aggregate stability was evaluated according to the method described by Le Bissonnais (1996), results were expressed as a mean weight diameter (MWD); higher values of MWD indicate higher aggregate stability. Total organic carbon (TOC) was determined using the wet oxidation method of Walkley-Black. A significant increase in SOC content was observed in CA>5years (1.64 %) compared to CT (0.97 %). This result highlights the importance of CA to improve soil fertility. For aggregate stability, a net increase was observed in CA compared to CT. After 5 years of CA the MWD was increased by 16% (MWD=1.8 mm for CT and MWD=2.1 mm for CA<5years). No

  16. Interaction of metal layers with polycrystalline Si

    NASA Technical Reports Server (NTRS)

    Nakamura, K.; Olowolafe, J. O.; Lau, S. S.; Nicolet, M.-A.; Mayer, J. W.; Shima, R.

    1976-01-01

    Solid-phase reactions of metal films deposited on 0.5-micron-thick polycrystalline layers of Si grown by chemical vapor deposition at 640 C were investigated by MeV He-4 backscattering spectrometry, glancing angle X-ray diffraction, and SEM observations. For the metals Al, Ag, and Au, which form simple eutectics, heat treatment at temperatures below the eutectic results in erosion of the poly-Si layer and growth of Si crystallites in the metal film. Crystallite formation is observed at temperatures exceeding 550 C for Ag, at those exceeding 400 C for Al, and at those exceeding 200 C for Au films. For Pd, Ni, and Cr, heat treatment results in silicide formation. The same initial silicides (Pd2Si, Ni2Si, and CrSi2), are formed at similar temperatures on single-crystal substrates.

  17. Analyses of 1/15 scale Creare bypass transient experiments. [PWR

    SciTech Connect

    Kmetyk, L.N.; Buxton, L.D.; Cole, R.K. Jr.

    1982-09-01

    RELAP4 analyses of several 1/15 scale Creare H-series bypass transient experiments have been done to investigate the effect of using different downcomer nodalizations, physical scales, slip models, and vapor fraction donoring methods. Most of the analyses were thermal equilibrium calculations performed with RELAP4/MOD5, but a few such calculations were done with RELAP4/MOD6 and RELAP4/MOD7, which contain improved slip models. In order to estimate the importance of nonequilibrium effects, additional analyses were performed with TRAC-PD2, RELAP5 and the nonequilibrium option of RELAP4/MOD7. The purpose of these studies was to determine whether results from Westinghouse's calculation of the Creare experiments, which weremore » done with a UHI-modified version of SATAN, were sufficient to guarantee SATAN would be conservative with respect to ECC bypass in full-scale plant analyses.« less

  18. Macrocyclic Receptor for Precious Gold, Platinum, or Palladium Coordination Complexes.

    PubMed

    Liu, Wenqi; Oliver, Allen G; Smith, Bradley D

    2018-06-06

    Two macrocyclic tetralactam receptors are shown to selectively encapsulate anionic, square-planar chloride and bromide coordination complexes of gold(III), platinum(II), and palladium(II). Both receptors have a preorganized structure that is complementary to its precious metal guest. The receptors do not directly ligate the guest metal center but instead provide an array of arene π-electron donors that interact with the electropositive metal and hydrogen-bond donors that interact with the outer electronegative ligands. This unique mode of supramolecular recognition is illustrated by six X-ray crystal structures showing receptor encapsulation of AuCl 4 - , AuBr 4 - , PtCl 4 -2 , or Pd 2 Cl 6 -2 . In organic solution, the 1:1 association constants correlate with specific supramolecular features identified in the solid state. Technical applications using these receptors are envisioned in a wide range of fields that involve precious metals, including mining, recycling, catalysis, nanoscience, and medicine.

  19. Ambient Temperature Synthesis of High Enantiopurity N-Protected Peptidyl Ketones by Peptidyl Thiol Ester–Boronic Acid Cross-Coupling

    PubMed Central

    Yang, Hao; Li, Hao; Wittenberg, Rüdiger; Egi, Masahiro; Huang, Wenwei; Liebeskind, Lanny S.

    2009-01-01

    α-Amino acid thiol esters derived from N-protected mono-, di-, and tripeptides couple with aryl, π-electron-rich heteroaryl, or alkenyl boronic acids in the presence of stoichiometric Cu(I) thiophene-2-carboxylate (CuTC) and catalytic Pd2(dba)3/triethylphosphite to generate the corresponding N-protected peptidyl ketones in good to excellent yields and in high enantiopurity. Triethylphosphite plays a key role as a supporting ligand by mitigating an undesired palladium-catalyzed decarbonylation-β-elimination of the α-amino thiol esters. The peptidyl ketone synthesis proceeds at room temperature under non-basic conditions and demonstrates a high tolerance to functionality. PMID:17263394

  20. Deuteron polarimetry at COSY

    SciTech Connect

    Chiladze, D.; High Energy Physics Institute, Tbilisi State University, 0186 Tbilisi; Grigoriev, K.

    2007-06-13

    The vector Pz and tensor Pzz polarizations of a deuteron beam have been measured using elastic deuteron-carbon scattering at 75.6 MeV and deuteron-proton scattering at 270 MeV. After acceleration to 1170 MeV inside the COSY storage ring, the polarizations of the deuterons were remeasured by studying the analyzing powers of a variety of nuclear reactions at the ANKE magnetic spetrometer. The overall precisions obtained were about 4% for both Pz and Pzz. One of the motivation for the experimental programme is the direct reconstruction of the spin-dependent amplitudes, including relative phases, of large angle neutron-proton elastic scattering, through the studymore » of the p(d,2p)n charge-exchange reaction up to the highest available deuteron energy at COSY (2.3 GeV)« less

  1. A novel and general synthetic pathway to strychnos indole alkaloids: total syntheses of (-)-tubifoline, (-)-dehydrotubifoline, and (-)-strychnine using palladium-catalyzed asymmetric allylic substitution.

    PubMed

    Mori, Miwako; Nakanishi, Masato; Kajishima, Daisuke; Sato, Yoshihiro

    2003-08-13

    A method of palladium-catalyzed asymmetric allylic substitution for synthesizing 2-substituted cyclohexenylamine derivatives was established. Treatment of a 2-silyloxymethylcyclohexenol derivative with ortho-bromo-N-tosylaniline in the presence of Pd(2)dba(3).CHCl(3) and (S)-BINAPO in THF afforded a cyclohexenylamine derivative with 84% ee in 80% yield. The Heck reaction was carried out to produce an indolenine derivative in good yield. Using this method, we synthesized indolenine derivative 7, which was recrystallized from EtOH to give an optically pure compound. From this compound, tetracyclic ketone 13, which should be a useful intermediate for the synthesis of indole alkaloids, could be synthesized. The total syntheses of (-)-dehydrotubifoline, (-)-tubifoline, and (-)-strychnine were achieved from 13. All ring constructions for the syntheses of these natural products were achieved using a palladium catalyst.

  2. Thermal activation in Au-based bulk metallic glass characterized by high-temperature nanoindentation

    NASA Astrophysics Data System (ADS)

    Yang, Bing; Wadsworth, Jeffrey; Nieh, Tai-Gang

    2007-02-01

    High-temperature nanoindentation experiments have been conducted on a Au49Ag5.5Pd2.3Cu26.9Si16.3 bulk metallic glass from 30to140°C, utilizing loading rates ranging from 0.1to100mN/s. Generally, the hardness decreased with increasing temperature. An inhomogeneous-to-homogeneous flow transition was clearly observed when the test temperature approached the glass transition temperature. Analyses of the pop-in pattern and hardness variation showed that the inhomogeneous-to-homogeneous transition temperature was loading-rate dependent. Using a free-volume model, the authors deduced the size of the basic flow units and the activation energy for the homogeneous flow. In addition, the strain rate dependency of the transition temperature was predicted.

  3. Chemicals from Biomass: Combining Ring-Opening Tautomerization and Hydrogenation Reactions to Produce 1,5-Pentanediol from Furfural.

    PubMed

    Brentzel, Zachary J; Barnett, Kevin J; Huang, Kefeng; Maravelias, Christos T; Dumesic, James A; Huber, George W

    2017-04-10

    A process for the synthesis of 1,5-pentanediol (1,5-PD) with 84 % yield from furfural is developed, utilizing dehydration/hydration, ring-opening tautomerization, and hydrogenation reactions. Although this process has more reaction steps than the traditional direct hydrogenolysis of tetrahydrofurfuryl alcohol (THFA), techno-economic analyses demonstrate that this process is the economically preferred route for the synthesis of biorenewable 1,5-PD. 2-Hydroxytetrahydropyran (2-HY-THP) is the key reaction pathway intermediate that allows for a decrease in the minimum selling price of 1,5-PD. The reactivity of 2-HY-THP is 80 times greater than that of THFA over a bimetallic hydrogenolysis catalyst. This enhanced reactivity is a result of the ring-opening tautomerization to 5-hydoxyvaleraldehyde and subsequent hydrogenation to 1,5-PD. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. The free-energy barrier to hydride transfer across a dipalladium complex

    DOE PAGES

    Ramirez-Cuesta, Anibal J.

    2015-01-01

    We use density-functional theory molecular dynamics (DFT-MD) simulations to determine the hydride transfer coordinate between palladium centres of the crystallographically observed terminal hydride locations, Pd-Pd-H, originally postulated for the solution dynamics of the complex bis-NHC dipalladium hydride [{(MesIm)(2)CH2}(2)Pd2H][PF6], and then calculate the free-energy along this coordinate. We estimate the transfer barrier-height to be about 20 kcal mol(-1) with a hydride transfer rate in the order of seconds at room temperature. We validate our DFT-MD modelling using inelastic neutron scattering which reveals anharmonicity of the hydride environment that is so pronounced that there is complete failure of the harmonic model formore » the hydride ligand. The simulations are extended to high temperature to bring the H-transfer to a rate that is accessible to the simulation technique.« less

  5. A versatile MOF-based trap for heavy metal ion capture and dispersion.

    PubMed

    Peng, Yaguang; Huang, Hongliang; Zhang, Yuxi; Kang, Chufan; Chen, Shuangming; Song, Li; Liu, Dahuan; Zhong, Chongli

    2018-01-15

    Current technologies for removing heavy metal ions are typically metal ion specific. Herein we report the development of a broad-spectrum heavy metal ion trap by incorporation of ethylenediaminetetraacetic acid into a robust metal-organic framework. The capture experiments for a total of 22 heavy metal ions, covering hard, soft, and borderline Lewis metal ions, show that the trap is very effective, with removal efficiencies of >99% for single-component adsorption, multi-component adsorption, or in breakthrough processes. The material can also serve as a host for metal ion loading with arbitrary selections of metal ion amounts/types with a controllable uptake ratio to prepare well-dispersed single or multiple metal catalysts. This is supported by the excellent performance of the prepared Pd 2+ -loaded composite toward the Suzuki coupling reaction. This work proposes a versatile heavy metal ion trap that may find applications in the fields of separation and catalysis.

  6. High Activity and Efficient Turnover by a Simple, Self-Assembled "Artificial Diels-Alderase".

    PubMed

    Martí-Centelles, Vicente; Lawrence, Andrew L; Lusby, Paul J

    2018-02-28

    The Diels-Alder (DA) reaction is a cornerstone of synthesis, yet Nature does not use catalysts for intermolecular [4+2] cycloadditions. Attempts to create artificial "Diels-Alderases" have also met with limited success, plagued by product inhibition. Using a simple Pd 2 L 4 capsule we now show DA catalysis that combines efficient turnover alongside enzyme-like hallmarks. This includes excellent activity (k cat /k uncat > 10 3 ), selective transition-state stabilization comparable to the most proficient DA catalytic antibodies, and control over regio- and chemoselectivity that would otherwise be difficult to achieve using small-molecule catalysts. Unlike other catalytic approaches that use synthetic capsules, this method is not defined by entropic effects; instead multiple H-bonding interactions modulate reactivity, reminiscent of enzymatic action.

  7. A structural model for surface-enhanced stabilization in some metallic glass formers

    NASA Astrophysics Data System (ADS)

    Levchenko, Elena V.; Evteev, Alexander V.; Yavari, Alain R.; Louzguine-Luzgin, Dmitri V.; Belova, Irina V.; Murch, Graeme E.

    2013-01-01

    A structural model for surface-enhanced stabilization in some metallic glass formers is proposed. In this model, the alloy surface structure is represented by five-layer Kagomé-net-based lateral ordering. Such surface structure has intrinsic abilities to stabilize icosahedral-like short-range order in the bulk, acting as 'a cloak of liquidity'. In particular, recent experimental observations of surface-induced lateral ordering and a very high glass forming ability of the liquid alloy Au49Ag5.5Pd2.3Cu26.9Si16.3 can be united using this structural model. This model may be useful for the interpretation of surface structure of other liquid alloys with a high glass forming ability. In addition, it suggests the possibility of guiding the design of the surface coating of solid containers for the stabilization of undercooled liquids.

  8. Responses of equine trachealis and lung parenchyma to methacholine, histamine, serotonin, prostanoids, and leukotrienes in vitro.

    PubMed

    Doucet, M Y; Jones, T R; Ford-Hutchinson, A W

    1990-03-01

    The responses of equine trachealis and lung parenchymal strips to a range of contractile agonists were studied. Equine trachealis responded to methacholine greater than histamine greater than serotonin as shown by the maximal responses but failed to respond to either leukotrienes (LT), prostaglandin F2 alpha, or U-44069. Equine parenchymal strips showed considerable tonal activity and responded to LTD4 congruent to LTC4 greater than U-44069 = LTE4 greater than methacholine congruent to histamine congruent to serotonin greater than prostaglandin F2 alpha as determined through pD2 values. Neither the concentration response curve to LTD4 nor the intrinsic tonal activity of the preparations was modified by pretreatment with either atropine or indomethacin, although the maximal response to LTD4 was reversed by addition of the LTD4 receptor antagonist, MK-571. Thus arachidonic acid metabolites, including LTs, must be considered potential mediators of equine small airway disease, a potential model of human bronchial asthma.

  9. SciTech Connect

    Sleaford, Brad W.; Hurst, Aaron M.

    This report describes the measurement, evaluation and incorporation of new -ray spectroscopic data into the Evaluated Nuclear Data File (ENDF) for nonproliferation applications. Analysis and processing techniques are described along with key deliverables that have been met over the course of this project. A total of nine new ENDF libraries have been submitted to the National Nuclear Data Center at the Brookhaven National Laboratory and are now available in the ENDF/B-VIII.beta2 release. Furthermore, this project has led to more than ten peer-reviewed publications and provided theses for ve graduate students. This project is a component of the NA-22 venture collaborationmore » on \\Correlated Nuclear Data in Fission Events" (LA14-V-CorrData-PD2Jb).« less

  10. Salt-induced square prism Pd microtubes and their ethanol electrocatalysis properties

    NASA Astrophysics Data System (ADS)

    Jiang, Kunpeng; Ma, Shenghua; Wang, Yinan; Zhang, Ying; Han, Xiaojun

    2017-05-01

    The synthesis of square prism tubes are always challenging due to their thermo and dynamical instability. We demonstrated a simple method using Pd2+ doped PoPD oligomers as building blocks to assemble into 1D square prism metal-organic microtubes, which consists of cataphracted nanosheets on the surfaces. After high temperature treatment, the microtubes became square prism Pd tubes with a cross section size of 3 μm. The pure Pd microtubes showed excellent catalyzing activity towards the electro oxidation of ethanol. Their electrochemically active surface area is 48.2 m2 g-1, which indicates the square prism Pd tubes have great potential in the field of fuel cell.

  11. Electrochemical characterization of Pt-Ru-Pd catalysts for methanol oxidation reaction in direct methanol fuel cells.

    PubMed

    Choi, M; Han, C; Kim, I T; An, J C; Lee, J J; Lee, H K; Shim, J

    2011-01-01

    PtRuPd nanoparticles on carbon black were prepared and characterized as electrocatalysts for methanol oxidation reaction in direct methanol fuel cells. Nano-sized Pd (2-4 nm) particles were deposited on Pt/C and PtRu/C (commercial products) by a simple chemical reduction process. The structural and physical information of the PtRuPd/C were confirmed by TEM and XRD, and their electrocatalytic activities were measured by cyclic voltammetry and linear sweep voltammetry. The catalysts containing Pd showed higher electrocatalytic activity for methanol oxidation reaction than the other catalysts. This might be attributed to an increase in the electrochemical surface area of Pt, which is caused by the addition of Pd; this results in increased catalyst utilization.

  12. Phosphine-free Stille-Migita chemistry for the mild and orthogonal modification of DNA and RNA.

    PubMed

    Krause, André; Hertl, Alexander; Muttach, Fabian; Jäschke, Andres

    2014-12-08

    An optimized catalyst system of [Pd2 (dba)3 ] and AsPh3 efficiently catalyzes the Stille reaction between a diverse set of functionalized stannanes and halogenated mono-, di- and oligonucleotides. The methodology allows for the facile conjugation of short and long nucleic acid molecules with moieties that are not compatible with conventional chemical or enzymatic synthesis, among them acid-, base-, or fluoride-labile protecting groups, fluorogenic and synthetically challenging moieties with good to near-quantitative yields. Notably, even azides can be directly introduced into oligonucleotides and (deoxy)nucleoside triphosphates, thereby giving direct access to "clickable" nucleic acids. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Spectroscopic and electrochemical characterization of some Schiff base metal complexes containing benzoin moiety

    NASA Astrophysics Data System (ADS)

    El-Shahawi, M. S.; Al-Jahdali, M. S.; Bashammakh, A. S.; Al-Sibaai, A. A.; Nassef, H. M.

    2013-09-01

    The ligation behavior of bis-benzoin ethylenediamine (B2ED) and benzoin thiosemicarbazone (BTS) Schiff bases towards Ru3+, Rh3+, Pd2+, Ni2+ and Cu2+ were determined. The bond length of M-N and spectrochemical parameters (10Dq, β, B and LFSE) of the complexes were evaluated. The redox characteristics of selected complexes were explored by cyclic voltammetry (CV) at Pt working electrode in non aqueous solvents. Au mesh (100 w/in.) optically transparent thin layer electrode (OTTLE) was also used for recording thin layer CV for selected Ru complex. Oxidation of some complexes occurs in a consecutive chemical reaction of an EC type mechanism. The characteristics of electron transfer process of the couples M2+/M3+ and M3+/M4+ (M = Ru3+, Rh3+) and the stability of the complexes towards oxidation and/or reduction were assigned. The nature of the electroactive species and reduction mechanism of selected electrode couples were assigned.

  14. The Elusive Palladium-Diazo Adduct Captured: Synthesis, Isolation and Structural Characterization of [(ArNHC-PPh2 )Pd(η2 -N2 C(Ph)CO2 Et)].

    PubMed

    Rull, Silvia G; Álvarez, Eleuterio; Fructos, Manuel R; Belderrain, Tomás R; Pérez, Pedro J

    2017-06-07

    The first example of a diazo palladium adduct is reported. The complexes [(ArNHC-PPh 2 )M(η 2 -N 2 C(Ph)CO 2 Et)] (M=Ni, 3; M=Pd, 4; ArNHC-PPh 2 =3-(2,6-diisopropylphenyl)-1-[(diphenylphosphino)ethyl]imidazol-2-ylidene) were prepared by ligand exchange with styrene-coordinated precursors [(ArNHC-PPh 2 )M(styrene)] (M=Ni, 1; M=Pd, 2). Complex 4 was fully characterized, including X-ray analyses; this constitutes the first example of a diazo adduct compound with palladium, thereby closing the gap between Groups 8 and 10 regarding this type of compounds. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Solution-processed soldering of carbon nanotubes for flexible electronics.

    PubMed

    Rao, K D M; Radha, B; Smith, K C; Fisher, T S; Kulkarni, G U

    2013-02-22

    We report a simple lithography-free, solution-based method of soldering of carbon nanotubes with Ohmic contacts, by taking specific examples of multi-walled carbon nanotubes (MWNTs). This is achieved by self-assembling a monolayer of soldering precursor, Pd(2+) anchored to 1,10 decanedithiol, onto which MWNTs could be aligned across the gap electrodes via solvent evaporation. The nanosoldering was realized by thermal/electrical activation or by both in sequence. Electrical activation and the following step of washing ensure selective retention of MWNTs spanning across the gap electrodes. The soldered joints were robust enough to sustain strain caused during the bending of flexible substrates as well as during ultrasonication. The estimated temperature generated at the MWNT-Au interface using an electro-thermal model is ∼150 °C, suggesting Joule heating as the primary mechanism of electrical activation. Further, the specific contact resistance is estimated from the transmission line model.

  16. [Quantitative analysis of landscape patterns at the juncture of Shaanxi, Shanxi and Inner Mongolia, based on remote sensing data--taking Yulin sheet TM image as an example].

    PubMed

    Li, Tuansheng

    2004-03-01

    Based on the TM image of Yulin sheet and with the help of ERDAS, ARC/INFO and ARC/VIEW software, the landscape of Yulin sheet was classified. Using the spatial pattern analysis software FRAGSTATS of the vector version, a set of landscape indices were calculated at three scale levels of patches, classes and landscape. The results showed that landscape pattern indices could be successfully used in characterizing the spatial pattern of the studied area. However, this study should be further extended to the landscape of the same area in other period to analyze its dynamic change. FRAGSTATS was a good software, but should be improved by adding some indices such as PD2 developed by us.

  17. Studies of an Optical Multi-Processor Interconnect

    DTIC Science & Technology

    1994-01-01

    that the destinations are uniformly distributed, I is given by (E2k-i 2 k(l -(1 -Pd)i)]ýE) N g -1 i+ ( -- Pd)- +2k- 1 2k - 2’-k’ + k(1 -- (1 -- pd)k...15oo 2000- Number of Nodes Figure 5.16: Variation of Maximum User Throughput with Size I I 94I I I I6 Io•MSe P (snowed) g (dsehd) o𔃺.0 OJU/ I£ 0. 00...curves. Table (6.9) shows that the size and topology of the network does not have any significant effect on the number g of threads needed to keep the

  18. Green synthesis of the Pd nanoparticles supported on reduced graphene oxide using barberry fruit extract and its application as a recyclable and heterogeneous catalyst for the reduction of nitroarenes.

    PubMed

    Nasrollahzadeh, Mahmoud; Sajadi, S Mohammad; Rostami-Vartooni, Akbar; Alizadeh, Mohammad; Bagherzadeh, Mojtaba

    2016-03-15

    Through this manuscript the green synthesis of palladium nanoparticles supported on reduced graphene oxide (Pd NPs/RGO) under the mild conditions through reduction of the graphene oxide and Pd(2+) ions using barberry fruit extract as reducing and stabilizing agent is reported. The as-prepared Pd NPs/RGO was characterized by UV-vis spectroscopy, X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). The Pd NPs/RGO could be used as an efficient and heterogeneous catalyst for reduction of nitroarenes using sodium borohydride in an environmental friendly medium. Excellent yields of products were obtained with a wide range of substrates and the catalyst was recycled multiple times without any significant loss of its catalytic activity. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Dietary trace amine-dependent vasoconstriction in porcine coronary artery

    PubMed Central

    Herbert, A A; Kidd, E J; Broadley, K J

    2008-01-01

    Background and purpose: The dietary trace amines tyramine and β-phenylethylamine (β-PEA) can increase blood pressure. However, the mechanisms involved in the vascular effect of trace amines have not been fully established. The purpose of this study was to evaluate whether trace amine-dependent vasoconstriction was brought about by tyramine and β-PEA acting as indirect sympathomimetic agents, as previously assumed, or whether trace amine-dependent vasoconstriction could be mediated by recently discovered trace amine-associated (TAA) receptors. Experimental approach: The responses to p-tyramine and β-PEA were investigated in vitro in rings of the left anterior descending coronary arteries of pigs. Key results: p-Tyramine induced a concentration-dependent (0.1–3 mM) vasoconstriction. The maximum response and pD2 value for p-tyramine was unaffected by endothelium removal or pre-treatment with antagonists for adrenoceptors, histamine, dopamine or 5-HT receptors. β-PEA also produced a concentration-dependent (0.3–10 mM) vasoconstriction which was unaffected by endothelium removal, β-adrenoceptor or 5-HT receptor antagonists. A substantial, but reduced, response to β-PEA was obtained in the presence of prazosin (α1-adrenoceptor antagonist), haloperidol (D2/D3 dopamine receptor antagonist) or mepyramine (H1 histamine receptor antagonist). The pD2 value for β-PEA was unaffected by any of the antagonists tested. Conclusions and implications: Vasoconstriction induced by p-tyramine does not involve an indirect sympathomimetic effect, although vasoconstriction caused by β-PEA may occur, in part, by this mechanism. We therefore propose that trace amine-dependent vasoconstriction is mediated by phenylethylamine-specific receptors, which are closely related to or identical to TAA receptors. These receptors could provide a target for new antihypertensive therapies. PMID:18604230

  20. The intermolecular interaction in D2 - CX4 and O2 - CX4 (X = F, Cl) systems: Molecular beam scattering experiments as a sensitive probe of the selectivity of charge transfer component.

    PubMed

    Cappelletti, David; Falcinelli, Stefano; Pirani, Fernando

    2016-10-07

    Gas phase collisions of a D 2 projectile by CF 4 and by CCl 4 targets have been investigated with the molecular beam technique. The integral cross section, Q, has been measured for both collisional systems in the thermal energy range and oscillations due to the quantum "glory" interference have been resolved in the velocity dependence of Q. The analysis of the measured Q(v) data provided novel information on the anisotropic potential energy surfaces of the studied systems at intermediate and large separation distances. The relative role of the most relevant types of contributions to the global interaction has been characterized. Extending the phenomenology of a weak intermolecular halogen bond, the present work demonstrates that while D 2 - CF 4 is basically bound through the balance between size (Pauli) repulsion and dispersion attraction, an appreciable intermolecular bond stabilization by charge transfer is operative in D 2 - CCl 4 . We also demonstrated that the present analysis is consistent with that carried out for the F( 2 P)-D 2 and Cl( 2 P)-D 2 systems, previously characterized by scattering experiments performed with state-selected halogen atom beams. A detailed comparison of the present and previous results on O 2 -CF 4 and O 2 -CCl 4 systems pinpointed striking differences in the behavior of hydrogen and oxygen molecules when they interact with the same partner, mainly due to the selectivity of the charge transfer component. The present work contributes to cast light on the nature and role of the intermolecular interaction in prototype systems, involving homo-nuclear diatoms and symmetric halogenated molecules.

  1. Phase Stability for the Pd-Si System. First-Principles, Experiments, and Solution-Based Modeling

    DOE PAGES

    Zhou, S. H.; Huo, Y.; Napolitano, Ralph E.

    2015-11-05

    Relative stabilities of the compounds in the binary Pd-Si system were assessed using first-principles calculations and experimental methods. Calculations of lattice parameters and enthalpy of formation indicate that Pd 5Si-μ, Pd 9Si 2-α, Pd 3 Si-β, Pd 2 Si-γ, and PdSi-δ are the stable phases at 0 K (-273 °C). X-ray diffraction analyses (XRD) and electron probe microanalysis (EPMA) of the as-solidified and heat-treated samples support the computational findings, except that the PdSi-δ phase was not observed at low temperature. Considering both experimental data and first-principles results, the compounds Pd 5 Si-μ, Pd 9 Si 2-α, Pd 3Si-β, and Pdmore » 2Si-γ are treated as stable phases down to 0 K (-273 °C), while the PdSi-δ is treated as being stable over a limited range, exhibiting a lower bound. Using these findings, a comprehensive solution-based thermodynamic model is formulated for the Pd-Si system, permitting phase diagram calculation. Moreover, the liquid phase is described using a three-species association model and other phases are treated as solid solutions, where a random substitutional model is adopted for Pd-fcc and Si-dia, and a two-sublattice model is employed for Pd 5Si-μ, Pd 9Si 2-α, Pd 3Si-β, Pd 2Si-γ, and PdSi-δ. Model parameters are fitted using available experimental data and first-principles data, and the resulting phase diagram is reported over the full range of compositions.« less

  2. Interfacial processes in the Pd/a-Ge:H system

    NASA Astrophysics Data System (ADS)

    Edelman, F.; Cytermann, C.; Brener, R.; Eizenberg, M.; Weil, R.; Beyer, W.

    1993-06-01

    The kinetics of phase transformation has been studied in a two-layer structure of Pd/a-Ge:H after vacuum annealing at temperatures from 180 to 500°C. The a-Ge:H was deposited at 250°C on both c-Si and cleaved NaCl substrates in an RF glow discharge from a GeH 4/H 2 mixture. It was found that, similarly to the Pd/c-Ge and the Pd/a-Ge (e-gun deposited) systems, in the case of 0.15-0.2 μm Pd/0.6-1.0 μm a-Ge:H interfacial germanides formed first through the production of Pd 2Ge (plus a small amount of PdGe), and then PdGe was produced. The growth of both compounds was found to be diffusion-controlled. The nonreacted a-Ge:H layer beneath the germanide overlayer crystallized at 400-500°C. A reverse sequence of germanides formation was revealed in the case of 50 nm Pd/30 nm a-Ge:H, studied by in situ heat treatment in the TEM utilizing non-supported samples. The first germanide detected was PdGe and then, as a result of PdGe and Ge reaction or the PdGe decomposition, Pd 2Ge formed. The temperature dependence of the incubation time before the first ˜ 10 nm PdGe grains formed, followed an Arrhenius curve with an activation energy of 1.45 eV.

  3. Triazole-functionalized N-heterocyclic carbene complexes of palladium and platinum and efficient aqueous Suzuki-Miyaura coupling reaction.

    PubMed

    Gu, Shaojin; Xu, Hui; Zhang, Na; Chen, Wanzhi

    2010-07-05

    Imidazolium salts bearing triazole groups are synthesized via a copper catalyzed click reaction, and the silver, palladium, and platinum complexes of their N-heterocyclic carbenes are studied. [Ag(4)(L1)(4)](PF(6))(4), [Pd(L1)Cl](PF(6)), [Pt(L1)Cl](PF(6)) (L1=3-((1-benzyl-1H-1,2,3-triazol-4-yl)methyl)-1-(pyrimidin-2-yl)-1H-imidazolylidene), [Pd(2)(L2)(2)Cl(2)](PF(6))(2), and [Pd(L2)(2)](PF(6))(2) (L2=1-butyl-3-((1-(pyridin-2-yl)-1H-1,2,3-triazol-4-yl)methyl)imidazolylidene) have been synthesized and fully characterized by NMR, elemental analysis, and X-ray crystallography. The silver complex [Ag(4)(L1)(4)](PF(6))(4) consists of a Ag(4) zigzag chain. The complexes [Pd(L1)Cl](PF(6)) and [Pt(L1)Cl](PF(6)), containing a nonsymmetrical NCN' pincer ligand, are square planar with a chloride trans to the carbene donor. [Pd(2)(L2)(2)Cl(2)](PF(6))(2) consists of two palladium centers with CN(2)Cl coordination mode, whereas the palladium in [Pd(L2)(2)](PF(6))(2) is surrounded by two carbene and two triazole groups with two uncoordinated pyridines. The palladium compounds are highly active for Suzuki-Miyaura cross coupling reactions of aryl bromides and 1,1-dibromo-1-alkenes in neat water under an air atmosphere.

  4. Spatial imaging of carbon reactivity centers in Pd/C catalytic systems† †Electronic supplementary information (ESI) available: Detailed experimental procedures and FE-SEM images. See DOI: 10.1039/c5sc00802f

    PubMed Central

    Pentsak, E. O.; Kashin, A. S.; Polynski, M. V.; Kvashnina, K. O.; Glatzel, P.

    2015-01-01

    Gaining insight into Pd/C catalytic systems aimed at locating reactive centers on carbon surfaces, revealing their properties and estimating the number of reactive centers presents a challenging problem. In the present study state-of-the-art experimental techniques involving ultra high resolution SEM/STEM microscopy (1 Å resolution), high brilliance X-ray absorption spectroscopy and theoretical calculations on truly nanoscale systems were utilized to reveal the role of carbon centers in the formation and nature of Pd/C catalytic materials. Generation of Pd clusters in solution from the easily available Pd2dba3 precursor and the unique reactivity of the Pd clusters opened an excellent opportunity to develop an efficient procedure for the imaging of a carbon surface. Defect sites and reactivity centers of a carbon surface were mapped in three-dimensional space with high resolution and excellent contrast using a user-friendly nanoscale imaging procedure. The proposed imaging approach takes advantage of the specific interactions of reactive carbon centers with Pd clusters, which allows spatial information about chemical reactivity across the Pd/C system to be obtained using a microscopy technique. Mapping the reactivity centers with Pd markers provided unique information about the reactivity of the graphene layers and showed that >2000 reactive centers can be located per 1 μm2 of the surface area of the carbon material. A computational study at a PBE-D3-GPW level differentiated the relative affinity of the Pd2 species to the reactive centers of graphene. These findings emphasized the spatial complexity of the carbon material at the nanoscale and indicated the importance of the surface defect nature, which exhibited substantial gradients and variations across the surface area. The findings show the crucial role of the structure of the carbon support, which governs the formation of Pd/C systems and their catalytic activity. PMID:29511504

  5. Structure-activity relationship studies of (+/-)-terbutaline and (+/-)-fenoterol on beta3-adrenoceptors in the guinea pig gastric fundus.

    PubMed

    Horinouchi, T; Nakagawa, Y; Wakabayashi, M; Koike, K

    2001-08-01

    (+/-)-Terbutaline and (+/-)-fenoterol are both arylethanolamine analogs that have tertbutyl and aryliso-propyl substituents respectively at the a position on the nitrogen of the ethanolamine side chain. In the present study, we have investigated the structure-activity relationships of (+/-)-terbutaline and (+/-)-fenoterol as beta3-adrenoceptor agonists in the guinea pig gastric fundus. (+/-)-Terbutaline and (+/-)-fenoterol induced concentration-dependent relaxation of the precontracted gastric fundus with pD2 values of 4.45+/-0.10 and 5.90+/-0.09, and intrinsic activities of 1.00+/-0.03 and 0.99+/-0.01 respectively. The combination of the selective beta1-adrenoceptor antagonist (+/-)-atenolol (100 microM), and the selective beta2-adrenoceptor antagonist (+/-)-butoxamine (100 microM), produced a 2 and 6 fold rightward shift of the concentration-response curves for (+/-)-terbutaline and (+/-)-fenoterol respectively, without depressing the maximal responses. The order of potency of these agonists was (pD2 value): (+/-)-fenoterol (5.09+/-0.10) > (+/-)-terbutaline (4.13+/-0.08). In the presence of (+/-)-atenolol and (+/-)-butoxamine, however, the non-selective beta1, beta2- and beta3-adrenoceptor antagonist (+/-)-bupranolol caused a concentration-dependent rightward shift of the concentration-response curves for (+/-)-terbutaline and (+/-)-fenoterol. Schild plot analyses of the effects of (+/-)-bupranolol against these agonists gave pA2 values of 6.21+/-0.07 ((+/-)-terbutaline) and 6.37+/-0.06 ((+/-)-fenoterol) respectively, and the slopes of the Schild plot were not significantly different from unity (p>0.05). These results suggest that the relaxant responses to (+/-)-terbutaline and (+/-)-fenoterol are mainly mediated through beta3-adrenoceptors in the guinea pig gastric fundus. The beta3-adrenoceptor agonist potencies of arylethanolamine analogs depend on the size of the end of the alkylamine side chain.

  6. Facilitatory effects of selective agonists for tachykinin receptors on cholinergic neurotransmission: evidence for species differences.

    PubMed Central

    Belvisi, M. G.; Patacchini, R.; Barnes, P. J.; Maggi, C. A.

    1994-01-01

    1. Exogenous tachykinins modulate cholinergic neurotransmission in rabbit and guinea-pig airways. We have investigated the effect of selective tachykinin receptor agonists and antagonists on cholinergic neurotransmission evoked by electrical field stimulation (EFS) of bronchial rings in rabbit, guinea-pig and human airways in vitro to assess which type of tachykinin receptor is mediating this facilitatory effect. 2. Bronchial rings were set up for isometric tension recording. Contractile responses to EFS (60 V, 0.4 ms, 2 Hz for 10 s every min) and exogenous acetylcholine (ACh) were obtained and the effects of selective tachykinin agonists and antagonists were investigated. 3. In rabbit bronchi the endogenous tachykinins, substance P (SP) and neurokinin A (NKA) (10 nM) potentiated cholinergic responses to EFS (by 287.6 +/- 121%, P < 0.01 and 181.4 +/- 56.5%, P < 0.001 respectively). 4. The NK1 receptor selective agonist, [Sar9]SP sulphone (10 nM) evoked a maximal facilitatory action on cholinergic responses of 334.9 +/- 63% (P < 0.01) (pD2 = 8.5 +/- 0.06) an effect which was blocked by the selective NK1-receptor antagonist, CP 96,345 (100 nM) (P < 0.05) but not by the NK2 receptor antagonist, MEN 10,376 (100 nM). The NK2 receptor selective agonist, [beta Ala8]NKA(4-10) (10 nM), produced a maximum enhancement of 278 +/- 83.5% (P < 0.01) (pD2 = 8.7 +/- 0.1) an effect which was blocked by MEN 10,376 (100 nM) (P < 0.05) and not by CP 96,345. [MePhe7]NKB, an NK3 receptor selective agonist was without effect.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7516799

  7. The rabbit iris sphincter contains NK1 and NK3 but not NK2 receptors: a study with selective agonists and antagonists.

    PubMed

    Wang, Z Y; Håkanson, R

    1993-04-08

    Tachykinin analogues, claimed to be selective NK1, NK2 and NK3 receptor agonists, contracted the isolated rabbit iris sphincter muscle in a concentration-dependent manner. The contractions were not modified by the enkephalinase inhibitor thiorphan and the angiotensin-converting enzyme inhibitor captopril (10(-5) M of each). The pD2 values for (Sar9,Met(O2)11)SP (NK1 receptor agonist), (Nle10)NKA(4-10) (NK2 receptor agonist) and (MePhe7)NKB (NK3 receptor agonist) were 8.3, 6.1 and 8.2, respectively. (Sar9,Met(O2)11)SP was the most efficacious of the three agonists. The results are compatible with the presence of NK1 and NK3 receptors. The low pD2 value for the NK2 agonist may reflect a lack of NK2 receptors and interaction of the NK2 agonist with NK1 receptors. The contraction caused by the NK1 receptor agonist was inhibited competitively by the highly selective NK1 receptor antagonist (+/-) CP-96,345; the pA2 value was 5.5. Also the contraction caused by the NK2 receptor agonist was inhibited competitively by (+/-) CP-96,345 with a pA2 value of 5.7, supporting the view that the two agonists (Sar9,Met(O2)11)SP and (Nle10)NKA(4-10) interact with the same receptor. The selective NK2 receptor antagonist actinomycin D did not affect the contraction caused by the NK2 receptor agonist. We conclude that the rabbit iris sphincter muscle contains NK1 and probably NK3 receptors. We obtained no evidence for the presence of NK2 receptors.

  8. Tachykinin-induced contraction of the guinea-pig isolated oesophageal mucosa is mediated by NK2 receptors

    PubMed Central

    Kerr, Karen P; Thai, Binh; Coupar, Ian M

    2000-01-01

    The tachykinin receptor present in the guinea-pig oesophageal mucosa that mediates contractile responses of the muscularis mucosae has been characterized, using functional in vitro experiments. The NK1 receptor-selective agonist, [Sar9(O2)Met11]SP and the NK3 receptor-selective agonists, [MePhe7]-NKB and senktide, produced no response at submicromolar concentrations. The NK2 receptor-selective agonists, [Nle10]-NKA(4–10), and GR 64,349 produced concentration-dependent contractile effects with pD2 values of 8.20±0.16 and 8.30±0.15, respectively. The concentration-response curve to the non-selective agonist, NKA (pD2=8.13±0.04) was shifted significantly rightwards only by the NK2 receptor-selective antagonist, GR 159,897 and was unaffected by the NK1 receptor-selective antagonist, SR 140,333 and the NK3 receptor-selective antagonist, SB 222,200. The NK2 receptor-selective antagonist, GR 159,897, exhibited an apparent competitive antagonism against the NK2 receptor-selective agonist, GR 64,349 (apparent pKB value=9.29±0.16) and against the non-selective agonist, NKA (apparent pKB value=8.71±0.19). The NK2 receptor-selective antagonist, SR 48,968 exhibited a non-competitive antagonism against the NK2 receptor-selective agonist, [Nle10]-NKA(4–10). The pKB value was 10.84±0.19. It is concluded that the guinea-pig isolated oesophageal mucosa is a useful preparation for studying the effects of NK2 receptor-selective agonists and antagonists as the contractile responses to various tachykinins are mediated solely by NK2 receptors. PMID:11090121

  9. Differences in age at death according to smoking and age at menopause.

    PubMed

    Bellavia, Andrea; Wolk, Alicja; Orsini, Nicola

    2016-01-01

    Younger age at menopause is associated with overall mortality, and cigarette smoking is the only lifestyle factor influencing this association. However, the combined effects of age at menopause and smoking have never been quantified in terms of survival time. Our aim was to evaluate, in a large cohort of Swedish women, differences in age at death according to age at menopause and smoking status. Age at menopause and smoking were assessed, using a self-administered questionnaire, in a population-based cohort of 25,474 women aged 48 to 83 years. Laplace regression was used to calculate differences in median age at death (50th percentile difference [PD]) according to smoking and age at menopause. Across 16 years of follow-up, 5,942 participants died. The difference in median age at death between women with menopause at 40 years and women with menopause at 60 years was 1.3 years (50th PD, 1.3; 95% CI, 0.3-2.2). Compared with current smokers, former smokers and never smokers had older median age at death-2.5 years (50th PD, 2.5; 95% CI, 1.9-3.1) and 3.6 years (50th PD, 3.6; 95% CI, 3.1-4.1), respectively. When analysis was restricted to current smokers, the difference in age at death between women with menopause at 40 years and women with menopause at 60 years increased to 2.6 years (50th PD, 2.6; 95% CI, 0.8-4.5). No association among never smokers was observed. Younger age at menopause is linearly associated with shorter survival. This association tends to be stronger among current smokers.

  10. Phase Stability for the Pd-Si System. First-Principles, Experiments, and Solution-Based Modeling

    SciTech Connect

    Zhou, S. H.; Huo, Y.; Napolitano, Ralph E.

    Relative stabilities of the compounds in the binary Pd-Si system were assessed using first-principles calculations and experimental methods. Calculations of lattice parameters and enthalpy of formation indicate that Pd 5Si-μ, Pd 9Si 2-α, Pd 3 Si-β, Pd 2 Si-γ, and PdSi-δ are the stable phases at 0 K (-273 °C). X-ray diffraction analyses (XRD) and electron probe microanalysis (EPMA) of the as-solidified and heat-treated samples support the computational findings, except that the PdSi-δ phase was not observed at low temperature. Considering both experimental data and first-principles results, the compounds Pd 5 Si-μ, Pd 9 Si 2-α, Pd 3Si-β, and Pdmore » 2Si-γ are treated as stable phases down to 0 K (-273 °C), while the PdSi-δ is treated as being stable over a limited range, exhibiting a lower bound. Using these findings, a comprehensive solution-based thermodynamic model is formulated for the Pd-Si system, permitting phase diagram calculation. Moreover, the liquid phase is described using a three-species association model and other phases are treated as solid solutions, where a random substitutional model is adopted for Pd-fcc and Si-dia, and a two-sublattice model is employed for Pd 5Si-μ, Pd 9Si 2-α, Pd 3Si-β, Pd 2Si-γ, and PdSi-δ. Model parameters are fitted using available experimental data and first-principles data, and the resulting phase diagram is reported over the full range of compositions.« less

  11. Pharmacological characterisation of extracts of coffee dusts.

    PubMed Central

    Zuskin, E; Duncan, P G; Douglas, J S

    1983-01-01

    The contractile or relaxant activities or both of aqueous extracts of green and roasted coffees were assayed on isolated guinea pig tracheal spirals. Contractile and relaxant activities were compared with histamine and theophylline, respectively. Green coffee extracts induced concentration dependent contraction, but the maximal tension never exceeded 76.3% +/- 5.2 of a maximal histamine contraction (0.69 +/- 0.07 g/mm2 v 0.52 +/- 0.05 g/mm2; p (0.01). One gram of green coffee dust had a biological activity equivalent to 1.23 +/- 0.1 mg of histamine. The pD2 value of histamine was -5.17 +/- 0.05. The potency of green coffee was unaffected by mepyramine maleate (1 micrograms/ml, final bath concentration) while that of histamine was reduced 500 fold. Tissues contracted with histamine were not significantly relaxed by green coffee extracts. By contrast, roasted coffee extracts induced concentration dependent relaxation of uncontracted and histamine contracted tissues. Tissues contracted with green coffee extracts were also completely relaxed by roasted coffee extracts. The pD2 value of theophylline was -4.10 +/- 0.03. The relaxant activity of 1 g of roasted coffee was equivalent to 1.95 +/- 0.16 mg of theophylline. The potency of these extracts was significantly reduced after propranolol (1 micrograms/ml; dose ratio 1.56). Our results show that coffee dust extracts have considerable biological activity which changes from a contractile to a relaxant action as a consequence of processing. The greater incidence of adverse reactions to green coffee dust(s) in coffee workers may be related to the contractile activity present in green coffee dust. PMID:6830717

  12. Changes in Periodontal Parameters and C-Reactive Protein After Pregnancy.

    PubMed

    Raga, Lucía Gil; Mínguez, Ignacio; Caffesse, Raul; Llambés, Fernando

    2016-12-01

    This study assesses hormonal, inflammatory, and periodontal changes in pregnant women and postpartum in the absence of periodontal treatment, and seeks to determine any correlations among these parameters. A longitudinal, observational study of 117 pregnant women (aged 23 to 42 years) was undertaken in a private gynecologic center between weeks 32 and 35 of pregnancy and 6 to 8 weeks after delivery. Levels of progesterone and C-reactive protein (CRP) in plasma were determined, as well as periodontal indices, including: 1) plaque index (PI); 2) bleeding on probing (BOP); 3) probing depth (PD); and 4) clinical attachment level (CAL). Postpartum progesterone and CRP declined sharply from 90.85 ± 42.51 ng/mL and 3.73 ± 4.01 mg/L to 0.77 ± 1.43 ng/mL and 1.43 ± 1.67 mg/L, respectively. There was also a significant improvement in all periodontal indices (P <0.05) with the exception of PI. During pregnancy mean BOP was 21.03%, mean PD 2.62 mm, and mean CAL 1.20 mm. After delivery mean BOP was 13.25%, mean PD 2.39 mm, and mean CAL 1.14 mm. Percentage of 1- to 3-mm pockets increased (P <0.05), while 4- to 5-mm pockets and pockets >6 mm decreased significantly (P <0.001). Reduction in CRP correlated significantly with decrease in BOP (P <0.001). Postpartum, there was a dramatic reduction in progesterone and CRP, together with an improvement in BOP, PD, and CAL in the absence of periodontal treatment. Decrease in CRP was related to an improvement in periodontal bleeding.

  13. A Comprehensive Study of Formic Acid Oxidation on Palladium Nanocrystals with Different Types of Facets and Twin Defects

    SciTech Connect

    Choi, Sang; Herron, Jeffrey A.; Scaranto, Jessica

    2015-07-13

    Palladium has been recognized as the best anodic, monometallic electrocatalyst for the formic acid oxidation (FAO) reaction in a direct formic acid fuel cell. Here we report a systematic study of FAO on a variety of Pd nanocrystals, including cubes, right bipyramids, octahedra, tetrahedra, decahedra, and icosahedra. These nanocrystals were synthesized with approximately the same size, but different types of facets and twin defects on their surfaces. Our measurements indicate that the Pd nanocrystals enclosed by {1 0 0} facets have higher specific activities than those enclosed by {1 1 1} facets, in agreement with prior observations for Pd single-crystalmore » substrates. If comparing nanocrystals predominantly enclosed by a specific type of facet, {1 0 0} or {1 1 1}, those with twin defects displayed greatly enhanced FAO activities compared to their single-crystal counterparts. To rationalize these experimental results, we performed periodic, self-consistent DFT calculations on model single-crystal substrates of Pd, representing the active sites present in the nanocrystals used in the experiments. The calculation results suggest that the enhancement of FAO activity on defect regions, represented by Pd(2 1 1) sites, compared to the activity of both Pd(1 0 0) and Pd(1 1 1) surfaces, could be attributed to an increased flux through the HCOO-mediated pathway rather than the COOH-mediated pathway on Pd(2 1 1). Since COOH has been identified as a precursor to CO, a site-poisoning species, a lower coverage of CO at the defect regions will lead to a higher activity for the corresponding nanocrystal catalysts, containing those defect regions.« less

  14. Catalytic Activity of Platinum Monolayer on Iridium and Rhenium Alloy Nanoparticles for the Oxygen Reduction Reaction

    SciTech Connect

    Karan, Hiroko I.; Sasaki, Kotaro; Kuttiyiel, Kurian

    2012-05-04

    A new type of electrocatalyst with a core–shell structure that consists of a platinum monolayer shell placed on an iridium–rhenium nanoparticle core or platinum and palladium bilayer shell deposited on that core has been prepared and tested for electrocatalytic activity for the oxygen reduction reaction. Carbon-supported iridium–rhenium alloy nanoparticles with several different molar ratios of Ir to Re were prepared by reducing metal chlorides dispersed on Vulcan carbon with hydrogen gas at 400 °C for 1 h. These catalysts showed specific electrocatalytic activity for oxygen reduction reaction comparable to that of platinum. The activities of Pt ML/Pd ML/Ir 2Re 1,more » Pt ML/Pd 2layers/Ir 2Re 1, and Pt ML/Pd 2layers/Ir 7Re 3 catalysts were, in fact, better than that of conventional platinum electrocatalysts, and their mass activities exceeded the 2015 DOE target. Our density functional theory calculations revealed that the molar ratio of Ir to Re affects the binding strength of adsorbed OH and, thereby, the O 2 reduction activity of the catalysts. The maximum specific activity was found for an intermediate OH binding energy with the corresponding catalyst on the top of the volcano plot. The monolayer concept facilitates the use of much less platinum than in other approaches. Finally, the results with the Pt ML/Pd ML/Ir 2Re electrocatalyst indicate that it is a promising alternative to conventional Pt electrocatalysts in low-temperature fuel cells.« less

  15. Report: complexation of β-sitosterol with tris (dibenzylideneacetone) dipalladium and its anti-microbial activity.

    PubMed

    Mahmood, Talat; Bibi, Yasmeen; Zafar, Raana; Wahab, Aneela; Mahmood, Iffat; Arshad, Nuzhat; Sherwani, Sikandar Khan

    2015-03-01

    β-sitosterol is a naturally occurring plant sterol (phytosterol) present in many fruits and vegetables. Scientific research has proven that β-sitosterol is helpful in maintaining the proper functioning of our body. Previously we described the complexation of β-sitosterol with trace metals (Mahmood et al., 2013). Trace metals after the formation of complex unable to absorb in the body and hence eliminated out from the body thus reducing metal toxicity (Marsha, 1996). The present article describes the complexation of μ-sitosterol with Palladium (Pd) metal. Palladium is a toxic metal and due to polluted and hazardous environment traces of this metal can be transferred into the body, which is harmful for human health. Our aim is to make Pd-sterol complex so that this toxic metal (Pd) does not absorb in the body and hence excreted out from the body in the complex form. In order to form this complex μ-sitosterol (Ib) is reacted with Tris (dibenzylideneacetone) dipalladium or [Pd(2) (DBA)(3)] (Ia) in 2:1 ratio in an inert atmosphere and dimethylformamid (DMF) added as a solvent. The resulting complex [Pd(2) (DBA)(3).(β-sitosterol) (Ic) was identified by various spectroscopic techniques such as IR, Mass and (1)H-NMR. This new organo metallic complex (Ic) also showed significant antibacterial and antifungal activity. The present work revealed that Pd-sterol complex does not only reduce metal toxicity but also helpful in minimizing bacterial and fungal infections present in the body. Our research also concluded that we must take plenty of fruits and vegetables in our diet so that natural plant sterol such as β-sitosterol can enhance our defense mechanism and maintain other functions of our body.

  16. Characterization of the tachykinin NK2 receptor in the human bronchus: influence of amastatin-sensitive metabolic pathways.

    PubMed Central

    Astolfi, M.; Treggiari, S.; Giachetti, A.; Meini, S.; Maggi, C. A.; Manzini, S.

    1994-01-01

    1. The aim of this study was to characterize the tachykinin NK2 receptor subtype mediating the spasmogenic response in the human isolated bronchus. The motor response to neurokinin A (NKA) and the selective NK2 agonist [beta Ala8]NKA(4-10), as well as the antagonistic effects of cyclic (L659,877) and linear (MEN 10376) peptide NK2 antagonists were assessed in the presence or absence of amastatin (an inhibitor of aminopeptidases A and M). 2. NKA was more potent than [beta Ala8]NKA(4-10) in eliciting bronchoconstriction (pD2 being 7,43 and 6,87 respectively). In the presence of amastatin (1 microM), the estimated affinity of [beta Ala8]NKA(4-10), but not that of NKA, was significantly increased to yield a pD2 of 7,44. 3. L659,877 and MEN 10376 inhibited [beta Ala8]NKA(4-10)-induced contraction with similar affinities; pA2 values were 5.7 +/- 0.22 and 6.3 +/- 0.32, respectively. Amastatin (1 microM) increased the potency of MEN 10376 to 7.28 +/- 0.46, whereas that of L659,877 was unaffected. 4. In the presence of amastatin the pseudopeptide MDL 28,564 behaved as a partial agonist. 5. We conclude that the NK2 receptor subtype present in the human bronchus has properties similar to those described for the circular muscle of the human colon and thus may be classified as a 'NK2A' subtype. We show that the apparent potency of peptides, bearing N-terminal acidic residues, is influenced by an amastatin-sensitive peptidase, possibly aminopeptidase A. PMID:8004400

  17. Characterization of the tachykinin NK2 receptor in the human bronchus: influence of amastatin-sensitive metabolic pathways.

    PubMed

    Astolfi, M; Treggiari, S; Giachetti, A; Meini, S; Maggi, C A; Manzini, S

    1994-02-01

    1. The aim of this study was to characterize the tachykinin NK2 receptor subtype mediating the spasmogenic response in the human isolated bronchus. The motor response to neurokinin A (NKA) and the selective NK2 agonist [beta Ala8]NKA(4-10), as well as the antagonistic effects of cyclic (L659,877) and linear (MEN 10376) peptide NK2 antagonists were assessed in the presence or absence of amastatin (an inhibitor of aminopeptidases A and M). 2. NKA was more potent than [beta Ala8]NKA(4-10) in eliciting bronchoconstriction (pD2 being 7,43 and 6,87 respectively). In the presence of amastatin (1 microM), the estimated affinity of [beta Ala8]NKA(4-10), but not that of NKA, was significantly increased to yield a pD2 of 7,44. 3. L659,877 and MEN 10376 inhibited [beta Ala8]NKA(4-10)-induced contraction with similar affinities; pA2 values were 5.7 +/- 0.22 and 6.3 +/- 0.32, respectively. Amastatin (1 microM) increased the potency of MEN 10376 to 7.28 +/- 0.46, whereas that of L659,877 was unaffected. 4. In the presence of amastatin the pseudopeptide MDL 28,564 behaved as a partial agonist. 5. We conclude that the NK2 receptor subtype present in the human bronchus has properties similar to those described for the circular muscle of the human colon and thus may be classified as a 'NK2A' subtype. We show that the apparent potency of peptides, bearing N-terminal acidic residues, is influenced by an amastatin-sensitive peptidase, possibly aminopeptidase A.

  18. Serological detection and analysis of anti-VP1 responses against various enteroviruses (EV) (EV-A, EV-B and EV-C) in Chinese individuals.

    PubMed

    Gao, Caixia; Ding, Yingying; Zhou, Peng; Feng, Jiaojiao; Qian, Baohua; Lin, Ziyu; Wang, Lili; Wang, Jinhong; Zhao, Chunyan; Li, Xiangyu; Cao, Mingmei; Peng, Heng; Rui, Bing; Pan, Wei

    2016-02-26

    The overall serological prevalence of EV infections based on ELISA remains unknown. In the present study, the antibody responses against VP1 of the EV-A species (enterovirus 71 (EV71), Coxsackievirus A16 (CA16), Coxsackievirus A5 (CA5) and Coxsackievirus A6 (CA6)), of the EV-B species (Coxsackievirus B3 (CB3)), and of the EV-C species (Poliovirus 1 (PV1)) were detected and analyzed by a NEIBM (novel evolved immunoglobulin-binding molecule)-based ELISA in Shanghai blood donors. The serological prevalence of anti-CB3 VP1 antibodies was demonstrated to show the highest level, with anti-PV1 VP1 antibodies at the second highest level, and anti-CA5, CA6, CA16 and EV71 VP1 antibodies at a comparatively low level. All reactions were significantly correlated at different levels, which were approximately proportional to their sequence similarities. Antibody responses against EV71 VP1 showed obvious differences with responses against other EV-A viruses. Obvious differences in antibody responses between August 2013 and May 2014 were revealed. These findings are the first to describe the detailed information of the serological prevalence of human antibody responses against the VP1 of EV-A, B and C viruses, and could be helpful for understanding of the ubiquity of EV infections and for identifying an effective approach for seroepidemiological surveillance based on ELISA.

  19. The Saccharomyces cerevisiae LOS1 gene involved in pre-tRNA splicing encodes a nuclear protein that behaves as a component of the nuclear matrix.

    PubMed

    Shen, W C; Selvakumar, D; Stanford, D R; Hopper, A K

    1993-09-15

    Mutations of the Saccharomyces cerevisiae LOS1 gene cause the accumulation of end matured intron-containing pre-tRNAs at elevated temperatures. In an effort to decipher the role of the LOS1 protein in pre-tRNA splicing, we have analyzed the LOS1 gene and its protein product. The LOS1 gene is located on the left arm of chromosome XI and the order of genes in this area of the chromosome is .... URA1 ... SAC1 TRP3 UBA1 STE6 LOS1 .... FAS1..... The LOS1 open reading frame encodes a putative protein of 1100 amino acids that shows no significant homology to other genes. The LOS1 open reading frame was tagged with the influenza virus hemagglutinin epitope recognized by the 12CA5 antibody. The 12CA5 antibody recognizes an epitope-tagged protein of the size predicted by the LOS1 open reading frame. Using this antibody for indirect immunofluorescence and cell fractionation studies we show that the LOS1 protein is located in nuclei. Los1p cannot be extracted from nuclei by treatment with nucleases, salts, or Triton X-100. This insolubility suggests that Los1p is a component of the nucleoskeleton. We propose that LOS1 mutations may affect pre-tRNA processing via alteration of the nuclear matrix.

  20. Influence of holding temperature on the growth and survival of Salmonella spp. and Staphylococcus aureus and the production of staphylococcal enterotoxin in egg products.

    PubMed

    Yang, S E; Yu, R C; Chou, C C

    2001-01-22

    In this study, growth and survival of Salmonella spp. and Staphylococcus aureus in steamed egg and scrambled egg held at 5, 18, 22, 37, 55 and 60 degrees C are investigated. The production of staphylococcal enterotoxin in steamed egg is also examined. Results reveal that Salmonella spp. and Staph. aureus in the egg products multiply best at 37 degrees C, followed closely by 22 and 18 degrees C. Neither pathogen showed growth in the egg products held at 5 degrees C. Initial inoculation dose, holding temperature and holding time affected the population of both organisms found in the egg products. Staphylococcal enterotoxin A (SEA) and B (SEB) are detected only in the egg products held at 37 or 22 degrees C. After holding at 37 degrees C for 36 h, scrambled egg inoculated with ca. 5.0 log cfu/g Staph. aureus contains the highest levels of SEA (> 64 ng/g) and SEB (> 64 ng/g). Although Salmonella spp. and Staph. aureus grow better in steamed eggs than in scrambled eggs, production of staphylococcal enterotoxin, in general, was higher in scrambled eggs than in steamed eggs. On the other hand, a repaid destruction of the test organisms in steamed eggs held at 60 degrees C was observed. Holding the steamed eggs at 60 degrees C, Salmonella spp. and Staph. aureus with an initial population of ca. 5.9 and 5.6 log cfu/g, respectively, reduced to a non-detectable level in 1 h.

  1. Influence of heat treatments upon the mechanical properties and in vitro bioactivity of ZrO2-toughened MgO-CaO-SiO2-P2O5-CaF2 glass-ceramics.

    PubMed

    Li, Huan-Cai; Wang, Dian-Gang; Meng, Xiang-Guo; Chen, Chuan-Zhong

    2014-09-01

    Zirconia-toughened MgO-CaO-SiO2-P2O5-CaF2 glass-ceramics are prepared using sintering techniques, and a series of heat treatment procedures are designed to obtain a glass-ceramic with improved properties. The crystallization behavior, phase composition, and morphology of the glass-ceramics are characterized. The bending strength, elastic modulus, fracture toughness, and microhardness of the glass-ceramics are investigated, and the effect mechanism of heat treatments upon the mechanical properties is discussed. The bioactivity of glass-ceramics is then evaluated using the in vitro simulated body fluid (SBF) soaking test, and the mechanism whereby apatite forms on the glass-ceramic surfaces in the SBF solution is discussed. The results indicate that the main crystal phase of the G-24 sample undergoing two heat treatment procedures is Ca5(PO4)3F (fluorapatite), and those of the G-2444 sample undergoing four heat treatment procedures are Ca5(PO4)3F and β-CaSiO3 (β-wollastonite). The heat treatment procedures are found to greatly influence the mechanical properties of the glass-ceramic, and an apatite layer is induced on the glass-ceramic surface after soaking in the SBF solution.

  2. Investigation of exotic stable calcium carbides using theory and experiment

    DOE PAGES

    Li, Yan-Ling; Wang, Sheng-Nan; Oganov, Artem R.; ...

    2015-05-11

    It is well known that pressure causes profound changes in the properties of atoms and chemical bonding, leading to the formation of many unusual materials. Here we systematically explore all stable calcium carbides at pressures from ambient to 100 GPa using variable-composition evolutionary structure predictions. We find that Ca 5C 2, Ca 2C, Ca 3C 2, CaC, Ca 2C 3, and CaC 2 have stability fields on the phase diagram. Among these, Ca2C and Ca2C3 are successfully synthesized for the first time via high-pressure experiments with excellent structural correspondence to theoretical predictions. Of particular significance are the base-centered monoclinic phasemore » (space group C 2/m) of Ca 2C, a quasi-two-dimensional metal with layers of negatively charged calcium atoms, and the primitive monoclinic phase (space group P21/c) of CaC with zigzag C 4 groups. Interestingly, strong interstitial charge localization is found in the structure of R-3m-Ca 5C 2 with semimetallic behaviour.« less

  3. High spatial resolution and high brightness ion beam probe for in-situ elemental and isotopic analysis

    NASA Astrophysics Data System (ADS)

    Long, Tao; Clement, Stephen W. J.; Bao, Zemin; Wang, Peizhi; Tian, Di; Liu, Dunyi

    2018-03-01

    A high spatial resolution and high brightness ion beam from a cold cathode duoplasmatron source and primary ion optics are presented and applied to in-situ analysis of micro-scale geological material with complex structural and chemical features. The magnetic field in the source as well as the influence of relative permeability of magnetic materials on source performance was simulated using COMSOL to confirm the magnetic field strength of the source. Based on SIMION simulation, a high brightness and high spatial resolution negative ion optical system has been developed to achieve Critical (Gaussian) illumination mode. The ion source and primary column are installed on a new Time-of-Flight secondary ion mass spectrometer for analysis of geological samples. The diameter of the ion beam was measured by the knife-edge method and a scanning electron microscope (SEM). Results show that an O2- beam of ca. 5 μm diameter with a beam intensity of ∼5 nA and an O- beam of ca. 5 μm diameter with a beam intensity of ∼50 nA were obtained, respectively. This design will open new possibilities for in-situ elemental and isotopic analysis in geological studies.

  4. Effect of ZrO(2) additions on the crystallization, mechanical and biological properties of MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) bioactive glass-ceramics.

    PubMed

    Li, H C; Wang, D G; Meng, X G; Chen, C Z

    2014-06-01

    A series of ZrO(2) doped MgO-CaO-SiO(2)-P(2)O(5)-CaF(2) bioactive glass-ceramics were obtained by sintering method. The crystallization behavior, phase composition, morphology and structure of glass-ceramics were characterized. The bending strength, elastic modulus, fracture toughness, micro-hardness and thermal expansion coefficient (TEC) of glass-ceramics were investigated. The in vitro bioactivity and cytotoxicity tests were used to evaluate the bioactivity and biocompatibility of glass-ceramics. The sedimentation mechanism and growth process of apatites on sample surface were discussed. The results showed that the mainly crystalline phases of glass-ceramics were Ca(5)(PO4)3F (fluorapatite) and β-CaSiO(3). (β-wollastonite). m-ZrO(2) (monoclinic zirconia) declined the crystallization temperatures of glasses. t-ZrO(2) (tetragonal zirconia) increased the crystallization temperature of Ca(5)(PO4)(3)F and declined the crystallization temperature of β-CaSiO(3). t-ZrO(2) greatly increased the fracture toughness, bending strength and micro-hardness of glass-ceramics. The nanometer apatites were induced on the surface of glass-ceramic after soaking 28 days in SBF (simulated body fluid), indicating the glass-ceramic has good bioactivity. The in vitro cytotoxicity test demonstrated the glass-ceramic has no toxicity to cell. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. [Evaluations of newborn screening program performance and enzymatic diagnosis of glucose-6-phosphate dehydrogenase deficiency in Guangzhou].

    PubMed

    Tang, F; Huang, Y L; Jiang, X; Jia, X F; Li, B; Feng, Y; Chen, Q Y; Tang, C F

    2018-05-02

    Objective: To reveal the molecular epidemiologic characteristics of glucose-6-phosphate dehydrogenase (G6PD) gene and to evaluate based on the genetic analysis the newborn screening program performance and enzymatic diagnosis of G6PD deficiency in Guangzhou. Methods: G6PD enzyme activities were measured by quantitative fluorescence assay in dry blood spots of 16 319 newborns(8 725 males, 7 594 females) 3-7 days after birth in Guangzhou Newborn Center. They were born in Guangzhou form Oct. 1 to 20, 2016. The cutoff value of G6PD was less than 2.6 U/g Hb in dry blood spots. G6PD deficiency was diagnosed when G6PD<1 700 U/L or G6PD/6PGD<1 in red blood cells. Genetic analysis of G6PD gene was performed on the dry blood spot samples of 823 newborns (including positive 346, negative 477)with various levels of G6PD enzyme activities through fluorescence PCR melting curve analysis(FMCA) to detect 15 kinds of mutations reported to be common among Chinese.G6PD gene Sanger sequency was performed in seven highly suspicious patients with negative results by FMCA. Results: (1) Using the cutoff value of G6PD< 2.6 U/g Hb , a total of 687(4.2%) newborns showed positive screening results, including 560 (6.4%) males and 127(1.7%) females. (2) Among the newborns with positive screening results, 214 males and 122 females were randomly chosen for G6PD gene analysis. The results showed that 197 (92.1%) males were hemizygote and 108(88.6%) females were mutation carriers with one to four alleles. Among the newborns with negative screening results, 41 males with G6PD 2.6-2.8 U/g Hb and 436 females with G6PD 2.6-4.5 U/g Hb were chosen for genetic analysis.Mutations were detected in 5(12.2%)boys, and 226(51.8%) girls were carriers.G6PD gene Sanger sequency of seven highly suspicious patients showed that c.406C>T, c.551C>T, c.835A>T hemizygote were found in 3 male's samples, respectively. (3) The estimated prevalence of harboring mutation was 6.0% in males and 13.5% in females according to

  6. Monoclinic structure of hydroxylpyromorphite Pb10(PO4)6(OH)2 - hydroxylmimetite Pb10(AsO4)6(OH)2 solid solution series

    NASA Astrophysics Data System (ADS)

    Giera, Alicja; Manecki, Maciej; Borkiewicz, Olaf; Zelek, Sylwia; Rakovan, John; Bajda, Tomasz; Marchlewski, Tomasz

    2016-04-01

    Seven samples of hydroxyl analogues of pyromorphite-mimetite solid solutions series were synthesized from aqueous solutions at 80° C in a computer-controlled chemistate: 200 mL aqueous solutions of 0.05M Pb(NO3)2 and 0.03M KH2AsO4 and/or KH2PO4 were dosed with a 0.25 mL/min rate to a glass beaker, which initially contained 100 mL of distilled water. Constant pH of 8 was maintained using 2M KOH. The syntheses yielded homogeneous fine-grained white precipitates composition of which was close to theoretical Pb10[(PO4)6-x(AsO4)x](OH)2, where x = 0, 1, 2, 3, 4, 5, 6. High-resolution powder X-ray diffraction data were obtained in transmission geometry at the beamline 11-BM at the Advanced Photon Source (Argonne National Laboratory in Illinois, USA). The structure Rietveld refinements based on starting parameters of either hexagonal hydroxylpyromorphite or monoclinic mimetite-M were performed using GSAS+EXPGUI software. Apatite usually crystallizes in the hexagonal crystal system with the space group P63/m. For the first time, however, the lowering of the hexagonal to monoclinic crystal symmetry was observed in the hydroxyl variety of pyromorphite-mimetite solid solution series. This is indicated by better fitting of the modeled monoclinic structure to the experimental data. The same is not the case for analogous calcium hydroxylapatite series Ca5(PO4)3OH - Ca5(AsO4)3OH (Lee et al. 2009). Systematical linear increase of unit cell parameters is observed with As substitution from a=9.88, b=19.75, and c=7.43 for Pb10(PO4)6(OH)2 to a=10.23, b=20.32, and c=7.51 for Pb10(AsO4)6(OH)2. A strong pseudohexagonal character (γ ≈ 120° and b ≈ 2a) of the analyzed monoclinic phases was established. This work is partially funded by AGH research grant no 11.11.140.319 and partially by Polish NCN grant No 2011/01/M/ST10/06999. Lee Y.J., Stephens P.W., Tang Y., Li W., Philips B.L., Parise J.B., Reeder R.J., 2009. Arsenate substitution in hydroxylapatite: Structural characterization

  7. New Co–Pd–Zn γ-Brasses with Dilute Ferrimagnetism and Co 2Zn 11 Revisited: Establishing the Synergism between Theory and Experiment

    SciTech Connect

    Xie, Weiwei; Miller, Gordon J

    2014-04-22

    A synergism between electronic structure theory and the targeted synthesis of new ternary γ-brass compounds is demonstrated in the Co–Zn system. Co 2Zn 11, which adopts a cubic γ-brass structure, is shown to be at the Zn-rich end of a homogeneity range that varies from 15.4 to 22.1 atom % Co. Four samples were examined by single-crystal diffraction, all of which crystallize in space group I43¯m with the lattice parameter ranging from 8.9851(1) to 8.8809(1) Å as the Co content increases. In the 26-atom γ-brass clusters, Co atoms preferentially occupy the outer tetrahedron (OT) sites and then replace Zn atomsmore » at the octahedron (OH) sites at higher Co concentrations. In addition, a small fraction of vacancies occurs on the inner tetrahedron (IT) sites. The electronic structure of Co 2Zn 11 shows two distinct pseudogaps near the Fermi level: one at 292 valence electrons per primitive unit cell and the other at 302–304 valence electrons per primitive unit cell. Using molecular orbital arguments applied to the body-centered cubic packing of the 26-atom Co 4Zn 22 γ-brass cluster, these pseudogaps arise from (i) splitting among the valence s and p orbitals, which gives rise to the Hume–Rothery electron counting rule, and (ii) splitting within the manifold of Co 3d orbitals via Co–Zn orbital interactions. Co 2Zn 11 is Pauli paramagnetic, although the density of states at the Fermi level is large, whereas Curie–Weiss behavior emerges for higher Co concentrations. Because Pd has a size and an electronegativity similar to those of Zn, and inspired by the pseudogaps in the electronic density of states curve of Co 2Zn 11, Pd-doped γ-brass compounds were designed and two new γ-brass compounds were obtained: Co 0.92(2)Pd 1.08Zn 11 and Co 2.50(1)Pd 2.50Zn 8. In these, the site preferences for Co and Pd can be rationalized by electronic structure calculations. The densities of states indicate that Co 3d states are the major contributors near their Fermi

  8. Effects of asymmetric dimethylarginine on renal arteries in portal hypertension and cirrhosis.

    PubMed

    Segarra, Gloria; Cortina, Belén; Mauricio, María Dolores; Novella, Susana; Lluch, Paloma; Navarrete-Navarro, Javier; Noguera, Inmaculada; Medina, Pascual

    2016-12-28

    To evaluate the effects of asymmetric dimethylarginine (ADMA) in renal arteries from portal hypertensive and cirrhotic rats. Rat renal arteries from Sham ( n = 15), pre-hepatic portal hypertension (PPVL; n = 15) and bile duct ligation and excision-induced cirrhosis (BDL; n = 15) were precontracted with norepinephrine, and additional contractions were induced with ADMA (10 -6 -10 -3 mol/L), an endogenous inhibitor of nitric oxide (NO) synthase. Concentration-response curves to acetylcholine (1 × 10 -9 -3 × 10 -6 mol/L) were determined in precontracted renal artery segments with norepinephrine in the absence and in the presence of ADMA. Kidneys were collected to determine the protein expression and activity of dimethylarginine dimethylaminohydrolase (DDAH), an enzyme that catabolizes ADMA. In renal arteries precontracted with norepinephrine, ADMA caused endothelium-dependent contractions. The pD 2 values to ADMA were similar in the Sham and PPVL groups (4.20 ± 0.08 and 4.11 ± 0.09, P > 0.05, respectively), but were lower than those of the BDL group (4.79 ± 0.16, P < 0.05). Acetylcholine-induced endothelium-dependent relaxation that did not differ, in terms of pD 2 and maximal relaxation, among the 3 groups studied. Treatment with ADMA (3 × 10 -4 mol/L) inhibited acetylcholine-induced relaxation in the 3 groups, but the inhibition was higher ( P < 0.05) in the BDL group compared with that for the Sham and PPVL groups. The mRNA and protein expression of DDAH-1 were similar in kidneys from the three groups. Conversely, DDAH-2 expression was increased ( P < 0.05) in PPVL and further enhanced ( P < 0.05) in the BDL group. However, renal DDAH activity was significantly decreased in the BDL group. Cirrhosis increased the inhibitory effect of ADMA on basal- and induced-release of NO in renal arteries, and decreased DDAH activity in the kidney.

  9. Effects of asymmetric dimethylarginine on renal arteries in portal hypertension and cirrhosis

    PubMed Central

    Segarra, Gloria; Cortina, Belén; Mauricio, María Dolores; Novella, Susana; Lluch, Paloma; Navarrete-Navarro, Javier; Noguera, Inmaculada; Medina, Pascual

    2016-01-01

    AIM To evaluate the effects of asymmetric dimethylarginine (ADMA) in renal arteries from portal hypertensive and cirrhotic rats. METHODS Rat renal arteries from Sham (n = 15), pre-hepatic portal hypertension (PPVL; n = 15) and bile duct ligation and excision-induced cirrhosis (BDL; n = 15) were precontracted with norepinephrine, and additional contractions were induced with ADMA (10-6-10-3 mol/L), an endogenous inhibitor of nitric oxide (NO) synthase. Concentration-response curves to acetylcholine (1 × 10-9-3 × 10-6 mol/L) were determined in precontracted renal artery segments with norepinephrine in the absence and in the presence of ADMA. Kidneys were collected to determine the protein expression and activity of dimethylarginine dimethylaminohydrolase (DDAH), an enzyme that catabolizes ADMA. RESULTS In renal arteries precontracted with norepinephrine, ADMA caused endothelium-dependent contractions. The pD2 values to ADMA were similar in the Sham and PPVL groups (4.20 ± 0.08 and 4.11 ± 0.09, P > 0.05, respectively), but were lower than those of the BDL group (4.79 ± 0.16, P < 0.05). Acetylcholine-induced endothelium-dependent relaxation that did not differ, in terms of pD2 and maximal relaxation, among the 3 groups studied. Treatment with ADMA (3 × 10-4 mol/L) inhibited acetylcholine-induced relaxation in the 3 groups, but the inhibition was higher (P < 0.05) in the BDL group compared with that for the Sham and PPVL groups. The mRNA and protein expression of DDAH-1 were similar in kidneys from the three groups. Conversely, DDAH-2 expression was increased (P < 0.05) in PPVL and further enhanced (P < 0.05) in the BDL group. However, renal DDAH activity was significantly decreased in the BDL group. CONCLUSION Cirrhosis increased the inhibitory effect of ADMA on basal- and induced-release of NO in renal arteries, and decreased DDAH activity in the kidney. PMID:28082806

  10. Enhanced catalytic performance for methane combustion of 3DOM CoFe2O4 by co-loading MnOx and Pd-Pt alloy nanoparticles

    NASA Astrophysics Data System (ADS)

    Li, Xiangyu; Liu, Yuxi; Deng, Jiguang; Xie, Shaohua; Zhao, Xingtian; Zhang, Yang; Zhang, Kunfeng; Arandiyan, Hamidreza; Guo, Guangsheng; Dai, Hongxing

    2017-05-01

    Three-dimensionally ordered macroporous (3DOM) CoFe2O4, zMnOx/3DOM CoFe2O4 (z = 4.99-12.30 wt%), and yPd-Pt/6.70 wt% MnOx/3DOM CoFe2O4 (y = 0.44-1.81 wt%; Pd/Pt molar ratio = 2.1-2.2) have been prepared using the polymethyl methacrylate microspheres-templating, incipient wetness impregnation, and bubble-assisted polyvinyl alcohol-protected reduction strategies, respectively. All of the samples were characterized by means of various techniques. Catalytic performance of the samples was measured for methane combustion. It is shown that the as-prepared samples exhibited a high-quality 3DOM structure (103 ± 20 nm in pore size) and a surface area of 19-28 m2/g, and the noble metal or alloy nanoparticles (NPs) with a size of 2.2-3.0 nm were uniformly dispersed on the macropore wall surface of 3DOM CoFe2O4. The loading of MnOx on CoFe2O4 gave rise to a slight increase in activity, however, the dispersion of Pd-Pt NPs on 6.70MnOx/3DOM CoFe2O4 significantly enhanced the catalytic performance, with the 1.81Pd2.1Pt/6.70MnOx/3DOM CoFe2O4 sample showing the highest activity (T10% = 255 °C, T50% = 301 °C, and T90% = 372 °C at a space velocity of 20,000 mL/(g h)). We believe that the excellent catalytic activity of 1.81Pd2.1Pt/6.70MnOx/3DOM CoFe2O4 was related to its well-dispersed Pd-Pt alloy NPs, high adsorbed oxygen species concentration, good low-temperature reducibility, and strong interaction between MnOx or Pd-Pt NPs and 3DOM CoFe2O4.

  11. Quantification of mitral regurgitation by automated cardiac output measurement: experimental and clinical validation

    NASA Technical Reports Server (NTRS)

    Sun, J. P.; Yang, X. S.; Qin, J. X.; Greenberg, N. L.; Zhou, J.; Vazquez, C. J.; Griffin, B. P.; Stewart, W. J.; Thomas, J. D.

    1998-01-01

    OBJECTIVES: To develop and validate an automated noninvasive method to quantify mitral regurgitation. BACKGROUND: Automated cardiac output measurement (ACM), which integrates digital color Doppler velocities in space and in time, has been validated for the left ventricular (LV) outflow tract but has not been tested for the LV inflow tract or to assess mitral regurgitation (MR). METHODS: First, to validate ACM against a gold standard (ultrasonic flow meter), 8 dogs were studied at 40 different stages of cardiac output (CO). Second, to compare ACM to the LV outflow (ACMa) and inflow (ACMm) tracts, 50 normal volunteers without MR or aortic regurgitation (44+/-5 years, 31 male) were studied. Third, to compare ACM with the standard pulsed Doppler-two-dimensional echocardiographic (PD-2D) method for quantification of MR, 51 patients (61+/-14 years, 30 male) with MR were studied. RESULTS: In the canine studies, CO by ACM (1.32+/-0.3 liter/min, y) and flow meter (1.35+/-0.3 liter/min, x) showed good correlation (r=0.95, y=0.89x+0.11) and agreement (deltaCO(y-x)=0.03+/-0.08 [mean+/-SD] liter/min). In the normal subjects, CO measured by ACMm agreed with CO by ACMa (r=0.90, p < 0.0001, deltaCO=-0.09+/-0.42 liter/min), PD (r=0.87, p < 0.0001, deltaCO=0.12+/-0.49 liter/min) and 2D (r=0.84, p < 0.0001, deltaCO=-0.16+/-0.48 liter/min). In the patients, mitral regurgitant volume (MRV) by ACMm-ACMa agreed with PD-2D (r= 0.88, y=0.88x+6.6, p < 0.0001, deltaMRV=2.68+/-9.7 ml). CONCLUSIONS: We determined that ACM is a feasible new method for quantifying LV outflow and inflow volume to measure MRV and that ACM automatically performs calculations that are equivalent to more time-consuming Doppler and 2D measurements. Additionally, ACM should improve MR quantification in routine clinical practice.

  12. The Paracrine Feedback Loop Between Vitamin D3 (1,25(OH)2D3) and PTHrP in Prehypertrophic Chondrocytes

    PubMed Central

    Bach, Frances C; Rutten, Kirsten; Hendriks, Kristyanne; Riemers, Frank M; Cornelissen, Peter; de Bruin, Alain; Arkesteijn, Ger J; Wubbolts, Richard; Horton, William A; Penning, Louis C; Tryfonidou, Marianna A

    2014-01-01

    The endocrine feedback loop between vitamin D3 (1,25(OH)2D3) and parathyroid hormone (PTH) plays a central role in skeletal development. PTH-related protein (PTHrP) shares homology and its receptor (PTHR1) with PTH. The aim of this study was to investigate whether there is a functional paracrine feedback loop between 1,25(OH)2D3 and PTHrP in the growth plate, in parallel with the endocrine feedback loop between 1,25(OH)2D3 and PTH. This was investigated in ATDC5 cells treated with 10−8 M 1,25(OH)2D3 or PTHrP, Col2-pd2EGFP transgenic mice, and primary Col2-pd2EGFP growth plate chondrocytes isolated by FACS, using RT-qPCR, Western blot, PTHrP ELISA, chromatin immunoprecipitation (ChIP) assay, silencing of the 1,25(OH)2D3 receptor (VDR), immunofluorescent staining, immunohistochemistry, and histomorphometric analysis of the growth plate. The ChIP assay confirmed functional binding of the VDR to the PTHrP promoter, but not to the PTHR1 promoter. Treatment with 1,25(OH)2D3 decreased PTHrP protein production, an effect which was prevented by silencing of the VDR. Treatment with PTHrP significantly induced VDR production, but did not affect 1α- and 24-hydroxylase expression. Hypertrophic differentiation was inhibited by PTHrP and 1,25(OH)2D3 treatment. Taken together, these findings indicate that there is a functional paracrine feedback loop between 1,25(OH)2D3 and PTHrP in the growth plate. 1,25(OH)2D3 decreases PTHrP production, while PTHrP increases chondrocyte sensitivity to 1,25(OH)2D3 by increasing VDR production. In light of the role of 1,25(OH)2D3 and PTHrP in modulating chondrocyte differentiation, 1,25(OH)2D3 in addition to PTHrP could potentially be used to prevent undesirable hypertrophic chondrocyte differentiation during cartilage repair or regeneration. PMID:24777663

  13. Effects of several potassium channel openers and glibenclamide on the uterus of the rat.

    PubMed Central

    Piper, I.; Minshall, E.; Downing, S. J.; Hollingsworth, M.; Sadraei, H.

    1990-01-01

    1. The ability of several potassium (K+) channel openers to inhibit spasm of the uterus of the nonpregnant rat and their susceptibility to antagonism by glibenclamide was assessed in vitro and in vivo. 2. In the isolated uterus exposed to oxytocin (0.2 nM), cromakalim, RP 49356 and pinacidil were of similar potency (mean pD2 = 6.4, 6.0 and 6.2 respectively) while minoxidil sulphate was of lower potency (pD2 = 4.7). Glibenclamide antagonized cromakalim and RP 49356 with the interactions consistent with competitive antagonism (mean pA2 of 6.57 and 7.00 respectively). Glibenclamide also antagonized pinacidil (pA2 = 6.22) but the slope of the Schild plot was significantly greater than -1. Neither salbutamol nor minoxidil sulphate was antagonized by glibenclamide (10 microM). 3. Cromakalim (1 and 10 microM), RP 49356 (1 and 10 microM), pinacidil (1 microM) and minoxidil sulphate (100 microM) suppressed spasm evoked by low (less than 40 mM) but not high (greater than or equal to 40 mM) KCl concentrations. Glibenclamide (10 microM) prevented cromakalim (10 microM)-, RP 49356 (10 microM)- and pinacidil (10 microM)-induced suppression of KCl (20 mM)-evoked spasm. Pinacidil (10 and 100 microM), cromakalim (100 microM) and salbutamol (0.01-1 microM) inhibited spasm evoked by all concentrations of KCl (10-80 mM). Suppression of spasm evoked by KCl (10-80 mM) by cromakalim (100 microM) and pinacidil (100 microM) was insensitive to glibenclamide (10 microM). 4. Cromakalim (0.1 mg kg-1) and RP 49356 (0.1 mg kg-1), given by i.v. bolus injection, inhibited uterine contractions, produced a fall in blood pressure and a slight tachycardia in the conscious ovariectomized rat.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2128195

  14. Investigation of the prejunctional α2-adrenoceptor mediated actions of MDMA in rat atrium and vas deferens

    PubMed Central

    Lavelle, Aisling; Honner, Valerie; Docherty, J R

    1999-01-01

    We have investigated the effects of methylenedioxymethamphetamine (MDMA, ‘ecstasy') on peripheral noradrenergic neurotransmission in the rat.In rat atrial slices pre-incubated with [3H]-noradrenaline and in the presence of desipramine (1 μM) to prevent effects of MDMA on basal outflow of tritium, MDMA (10 μM) significantly inhibited the release of tritium evoked by short trains of six pulses at 100 Hz every 10 s for 3 min. This effect did not occur in the presence of the α2-adrenoceptor antagonist yohimbine (1 μM).In epididymal portions of rat vas deferens in the presence of nifedipine (10 μM), MDMA produced a concentration-dependent inhibition of single pulse nerve stimulation-evoked contractions with a pD2 of 5.88±0.16 (n=4). Inhibitory effects of MDMA were antagonized by the α2-adrenoceptor antagonist yohimbine (0.3 μM), but not by the 5-hydroxytryptamine receptor antagonist cyanopindolol in a concentration (1 μM) which markedly antagonized the inhibitory actions of the 5-HT-1 receptor agonist 5-carboxamidotryptamine.In prostatic portions of rat vas deferens in the presence of cocaine (3 μM), MDMA produced a concentration-dependent inhibition of single pulse nerve stimulation-evoked contractions with a pD2 of 5.12±0.21 (n=4). In the absence of cocaine, only the highest concentration of MDMA (30 μM) produced an inhibition, but the α2-adrenoceptor antagonist yohimbine (0.3 μM) converted the response to MDMA from inhibition to potentiation of the stimulation-evoked contraction.In radioligand binding studies, MDMA showed similar affinities for α2B, α2C and α2D-adrenoceptor sites, with pKi values of 5.14±0.16, 5.11±0.05 and 5.31±0.14, respectively.It is concluded that MDMA has significant α2-adrenoceptor agonist actions. PMID:10556934

  15. Endothelial dysfunction and metabolic control in streptozotocin-induced diabetic rats

    PubMed Central

    Rodríguez-Mañas, Leocadio; Angulo, Javier; Peiró, Concepción; Llergo, José L; Sánchez-Ferrer, Alberto; López-Dóriga, Pedro; Sánchez-Ferrer, Carlos F

    1998-01-01

    The aim of this work was to study the influence of the metabolic control, estimated by the levels of glycosylated haemoglobin in total blood samples (HbA1c), in developing vascular endothelial dysfunction in streptozotocin-induced diabetic rats. Four groups of animals with different levels of insulin treatment were established, by determining HbA1c values in 5.5 to 7.4%, 7.5 to 9.4%, 9.5 to 12% and >12%, respectively.The parameters analysed were: (1) the endothelium-dependent relaxations to acetylcholine (ACh) in isolated aorta and mesenteric microvessels; (2) the vasodilator responses to exogenous nitric oxide (NO) in aorta; and (3) the existence of oxidative stress by studying the influence of the free radical scavenger superoxide dismutase (SOD) on the vasodilator responses to both ACh and NO.In both isolated aortic segments and mesenteric microvessels, the endothelium-mediated concentration-dependent relaxant responses elicited by ACh were significantly decreased when the vessels were obtained from diabetic animals but only with HbA1c values higher than 7.5%. There was a high correlation between HbA1c levels and the impairment of ACh-induced relaxations, measured by pD2 values.The concentration-dependent vasorelaxant responses to NO in endothelium-denuded aortic segments were significantly reduced only in vessels from diabetic animals with HbA1c values higher than 7.5%. Again, a very high correlation was found between the HbA1c values and pD2 for NO-evoked responses.In the presence of SOD, the responses to ACh or NO were only increased in the segments from diabetic rats with HbA1c levels higher than 7.5%, but not in those from non-diabetic or diabetic rats with a good metabolic control (HbA1c levels <7.5%).These results suggest the existence of: (1) a close relation between the degree of endothelial dysfunction and the metabolic control of diabetes, estimated by the levels of HbA1c; and (2) an increased production of superoxide anions in the vascular wall of the diabetic rats, which is also related to the metabolic control of the disease. PMID:9605553

  16. CHBPR: Decreased cGMP level contributes to increased contraction in arteries from hypertensive rats: role of PDE1

    PubMed Central

    Giachini, Fernanda R.; Lima, Victor V.; Carneiro, Fernando S.; Tostes, Rita C.; Webb, R. Clinton

    2011-01-01

    Recent evidence suggests that angiotensin II (Ang II) upregulates phosphodiesterase (PDE)-1A expression. We hypothesized that Ang II augmented PDE1 activation, decreasing the bioavailability of cyclic cyclic guanosine 3', 5'-monophosphate (cGMP), contributing to increased vascular contractility. Male Sprague-Dawley rats received mini-osmotic pumps with Ang II (60 ng.min−1) or saline for 14 days. PE-induced contractions were increased in aorta (Emax168±8 vs. 136±4%) and small-mesenteric arteries [(SMA), Emax170±6 vs. 143±3%] from Ang II infused rats compared to control. PDE1 inhibition with vinpocetine (10µM) reduced PE-induced contraction in aortas from Ang II rats (Emax94±12%) but not in control (154±7%). Vinpocetine decreased the sensitivity to PE in SMA from Ang II rats compared to vehicle (pD2 5.1±0.1 vs. 5.9±0.06), but not in control (6.0±0.03 vs. 6.1±0.04). Sildenafil (10µM), a PDE5 inhibitor reduced PE-induced maximal contraction similarly in Ang II and control rats. Arteries were contracted with PE (1µM) and concentration-dependent relaxation to vinpocetine and sildenafil was evaluated. Aortas from Ang II rats displayed increased relaxation to vinpocetine compared to control (Emax82±12 vs. 44±5%). SMA from Ang II rats showed greater sensitivity during vinpocetine-induced relaxation, compared to control (pD2 6.1±0.3 vs. 5.3±0.1). No differences in sildenafil-induced relaxation were observed. PDE1A and PDE1C expressions in aorta and PDE1A expression in SMA were increased in Ang II rats. cGMP production, which is decreased in arteries from Ang II rats, was restored after PDE1 blockade. We conclude that PDE1 activation reduces cGMP bioavailability in arteries from ANG II, contributing to increased contractile responsiveness. PMID:21282562

  17. Glutamate Neonatal Excitotoxicity Modifies VEGF-A, VEGF-B, VEGFR-1 and VEGFR-2 Protein Expression Profiles During Postnatal Development of the Cerebral Cortex and Hippocampus of Male Rats.

    PubMed

    Castañeda-Cabral, Jose Luis; Beas-Zarate, Carlos; Gudiño-Cabrera, Graciela; Ureña-Guerrero, Monica E

    2017-09-01

    Vascular endothelial growth factor (VEGF) exerts both neuroprotective and proinflammatory effects in the brain, depending on the VEGF (A-E) and VEGF receptor (VEGFR1-3) types involved. Neonatal monosodium glutamate (MSG) treatment triggers an excitotoxic degenerative process associated with several neuropathological conditions, and VEGF messenger RNA (mRNA) expression is increased at postnatal day (PD) 14 in rat hippocampus (Hp) following the treatment. The aim of this work was to establish the changes in immunoreactivity to VEGF-A, VEGF-B, VEGFR-1 and VEGFR-2 proteins induced by neonatal MSG treatment (4 g/kg, subcutaneous, at PD1, 3, 5 and 7) in the cerebral motor cortex (CMC) and Hp. Samples collected from PD2 to PD60 from control and MSG-treated male Wistar rats were assessed by western blotting for each protein. Considering that immunoreactivity measured by western blotting is related to the protein expression level, we found that each protein in each cerebral region has a specific expression profile throughout the studied ages, and all profiles were differentially modified by MSG. Specifically, neonatal MSG treatment significantly increased the immunoreactivity to the following: (1) VEGF-A at PD8-PD10 in the CMC and at PD6-PD8 in the Hp; (2) VEGF-B at PD2, PD6 and PD10 in the CMC and at PD8-PD9 in the Hp; and (3) VEGFR-2 at PD6-PD8 in the CMC and at PD21-PD60 in the Hp. Also, MSG significantly reduced the immunoreactivity to the following: (1) VEGF-B at PD8-PD9 and PD45-PD60 in the CMC; and (2) VEGFR-1 at PD4-PD6 and PD14-PD21 in the CMC and at PD4, PD9-PD10 and PD60 in the Hp. Our results indicate that VEGF-mediated signalling is involved in the excitotoxic process triggered by neonatal MSG treatment and should be further characterized.

  18. The Completely Sequenced Plasmid pEST4011 Contains a Novel IncP1 Backbone and a Catabolic Transposon Harboring tfd Genes for 2,4-Dichlorophenoxyacetic Acid Degradation

    PubMed Central

    Vedler, Eve; Vahter, Merle; Heinaru, Ain

    2004-01-01

    The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacterium Achromobacter xylosoxidans subsp. denitrificans strain EST4002 contains plasmid pEST4011. This plasmid ensures its host a stable 2,4-D+ phenotype. We determined the complete 76,958-bp nucleotide sequence of pEST4011. This plasmid is a deletion and duplication derivative of pD2M4, the 95-kb highly unstable laboratory ancestor of pEST4011, and was self-generated during different laboratory manipulations performed to increase the stability of the 2,4-D+ phenotype of the original strain, strain D2M4(pD2M4). The 47,935-bp catabolic region of pEST4011 forms a transposon-like structure with identical copies of the hybrid insertion element IS1071::IS1471 at the two ends. The catabolic regions of pEST4011 and pJP4, the best-studied 2,4-D-degradative plasmid, both contain homologous, tfd-like genes for complete 2,4-D degradation, but they have little sequence similarity other than that. The backbone genes of pEST4011 are most similar to the corresponding genes of broad-host-range self-transmissible IncP1 plasmids. The backbones of the other three IncP1 catabolic plasmids that have been sequenced (the 2,4-D-degradative plasmid pJP4, the haloacetate-catabolic plasmid pUO1, and the atrazine-catabolic plasmid pADP-1) are nearly identical to the backbone of R751, the archetype plasmid of the IncP1 β subgroup. We show that despite the overall similarity in plasmid organization, the pEST4011 backbone is sufficiently different (51 to 86% amino acid sequence identity between individual backbone genes) from the backbones of members of the three IncP1 subgroups (the α, β, and γ subgroups) that it belongs to a new IncP1subgroup, the δ subgroup. This conclusion was also supported by a phylogenetic analysis of the trfA2, korA, and traG gene products of different IncP1 plasmids. PMID:15489427

  19. Inhibitory effects of different ATP-sensitive potassium channel openers on electrically generated and carbachol-induced contractions of porcine and human detrusor muscle.

    PubMed

    Badawi, Jasmin Katrin; Ding, Andrea; Bross, Stephan

    2008-02-01

    The inhibitory effects of different potassium channel openers (PCOs) on electrically generated and carbachol-induced contractions of porcine and human detrusor muscle were examined. PCOs could be an interesting substance class for treatment of detrusor overactivity. Experiments were performed on muscle strips suspended in a tissue bath. Human tissue originated from patients who underwent total cystectomy. The concentration-relaxation curves of the first-generation PCOs cromakalim and pinacidil and the untypical PCO minoxidil were performed using carbachol-precontracted detrusor muscle strips of pigs and humans. Additionally, the inhibitory effects of cromakalim, pinacidil and minoxidil on electrically generated contractions of porcine detrusor muscle were examined. Furthermore, the inhibitory effect of the second-generation, bladder-selective PCO ZM 226600 on electrically generated contractions of the human detrusor muscle was determined. Frequency-response curves were performed before and after incubation with one PCO used in two different concentrations. In humans, cromakalim and pinacidil led to a maximum decrease of 73.5 and 68.4% and showed mean pD2 values of 6.65 and 5.5, respectively. In pigs, cromakalim and pinacidil led to a maximum decrease of 90.6 and 93.6% and showed mean pD2 values of 6.39 and 5.01, respectively. Minoxidil did not significantly decrease the precontraction at the highest used concentration in both species. Cromakalim exhibited the biggest inhibitory effect being significant at 10(-5) and 10(-6) M. Pinacidil showed only a significant inhibitory effect at 10(-5) M which was smaller than that of cromakalim. At 3 x 10(-6) M only a very small effect occurred at 1 Hz. Minoxidil did not inhibit the contractions at both examined concentrations except for a very small effect at 1 Hz. In humans, ZM 226600 exhibited at 10(-6) and 10(-5) M a significant inhibitory effect. At 10(-7) M it was only significant at one frequency.

  20. Catalytic property of fiber media supported palladium containing alloy nanoparticles and electrospun ceramic fibers biodurability study

    NASA Astrophysics Data System (ADS)

    Shin, Hyeon Ung

    The nanoscale of the supporting fibers may provide enhancements such as restricting the migration of metal catalyst particles. In this work, palladium nanoparticle doped alumina fibers were electrospun into template submicron fibers. These fibers were calcined at temperatures between 650°C and 1150°C to vary the crystal structures of the calcined fibers with the Pd particle size. Higher calcination temperatures led to higher reaction temperatures from 250 to about 450°C for total conversion, indicating the effective reactivity of the fiber-supported catalysts decreased with increase in calcination temperature. Pd-Au alloy nanoparticle doped titania fibers were also fabricated using an electrospinning method and assembled into a fibrous porous medium structure by a vacuum molding process. In reactor tests, the fiber media with Pd-Au alloy nanoparticle catalyst had greater reactivity in conversion of NO and CO gases than that of fiber media with Pd monometallic catalyst alone, attributed to a lower activation energy of the Pd-Au catalyst particles. In carbon monoxide oxidation reaction tests, the results showed that the performance was optimal for a catalyst of composition Pd2Au1 molar ratio that was active at 125°C, which had higher dispersion of active components and better catalytic performance compared to monometallic particle Au/TiO 2 and Pd/TiO2 fiber media. Moreover, the improved reaction activity of Pd2Au1/TiO2 fiber medium was attributed to a decreased in the activation energy. Further experiments were conducted using the electrospun ceramic fibers biodurability study. The properties of nano-sized fiber structures have attracted the attention of recent research on ceramic nanostructures as nonwoven media for applications in hazardous chemical and high temperature environments. However, health and safety concerns of micro and nano scale ceramic materials have not been fully investigated. Little is known about the physicochemical effects of the properties

  1. Synthesis and Properties of "Sandwich" Diimine-Coinage Metal Ethylene Complexes.

    PubMed

    Klimovica, Kristine; Kirschbaum, Kristin; Daugulis, Olafs

    2016-09-12

    Synthesis and full characterization of cationic isostructural "sandwich" diimine-coinage metal ethylene complexes are reported. Ethylene self-exchange kinetics proceeds by an associative exchange mechanism for Cu and Au complexes. The fastest ligand exchange was observed for Ag complex 8a . The upper limit of Δ G ‡ , assuming associative ligand exchange, was found to be ca. 5.0 kcal/mol. Ethylene self-exchange in Cu complex 7b proceeds with Δ G 298 ‡ = 12.9 ± 0.1 kcal/mol, while the exchange is the slowest in Au complex 9 , with Δ G 298 ‡ = 16.7 ± 0.1 kcal/mol. Copper complex 7b is unusually stable and can survive in air for years.

  2. The application of LIBS for the analysis of archaeological ceramic and metal artifacts

    NASA Astrophysics Data System (ADS)

    Melessanaki, Kristalia; Mateo, Maripaz; Ferrence, Susan C.; Betancourt, Philip P.; Anglos, Demetrios

    2002-09-01

    A bench-top laser-induced breakdown spectroscopy (LIBS) system has been used in the examination of pottery, jewelry and metal artifacts found in archaeological excavations in central and eastern Crete, Greece. The objects date from the Middle and Late Minoan periods (ca. 20th-13th century B. C.) through Byzantine and Venetian to Ottoman times (ca. 5th-19th century A.D.). The spectral data indicates the qualitative and often the semi-quantitative elemental composition of the examined materials. In the case of colored glazed ceramics, the identity of pigments was established while in the case of metal and jewelry analysis, the type of metal or metal alloy used was determined. The analyses demonstrate the potential of the LIBS technique for performing routine, rapid, on-site analysis of archaeological objects, which leads to the quick characterization or screening of different types of objects.

  3. Concurrent production of carotenoids and lipid by a filamentous microalga Trentepohlia arborum.

    PubMed

    Chen, Lin; Zhang, Lanlan; Liu, Tianzhong

    2016-08-01

    During the study of Trentepohlia arborum it became clear that its cells are rich in lipids and carotenoids. Thus, lipid content, composition and fatty acids profiles in individual lipid classes, as well as pigment profiles, responding to different culture conditions, were further investigated. The results showed that the predominant carotenoids and lipid fraction in total lipid in this study was β-carotene and TAG, respectively. The lipid content increased significantly under high light while nitrogen-replete conditions induced the highest carotenoids content. However, only with a double stress of high light and nitrogen-deficiency it was possible to maximize the productivities of both carotenoids and lipids. Carotenoids (mainly β-carotene) accounted for ca. 5% of the microalgal lipid under the double stress. Data herein show the potential of T. arborum for the production of both lipids and carotenoids, and hence provide an appropriate way to produce different products from T. arborum. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Integrating nanostructured electrodes in organic photovoltaic devices for enhancing near-infrared photoresponse

    SciTech Connect

    Nardes, Alexandre M.; Ahn, Sungmo; Rourke, Devin

    2016-12-01

    We introduce a simple methodology to integrate prefabricated nanostructured-electrodes in solution-processed organic photovoltaic (OPV) devices. The tailored 'photonic electrode' nanostructure is used for light management in the device and for hole collection. This approach opens up new possibilities for designing photonically active structures that can enhance the absorption of sub-bandgap photons in the active layer. We discuss the design, fabrication and characterization of photonic electrodes, and the methodology for integrating them to OPV devices using a simple lamination technique. We demonstrate theoretically and experimentally that OPV devices using photonic electrodes show a factor of ca. 5 enhancement in external quantummore » efficiency (EQE) in the near infrared region. We use simulations to trace this observed efficiency enhancement to surface plasmon polariton modes in the nanostructure.« less

  5. Evidence of interfacial charge trapping mechanism in polyaniline/reduced graphene oxide nanocomposites

    SciTech Connect

    Islam, Rakibul; Brun, Jean-François; Roussel, Frederick, E-mail: frederick.roussel@univ-lille1.fr

    Relaxation mechanisms in polyaniline (PANI)/Reduced Graphene Oxide (RGO) nanocomposites are investigated using broad band dielectric spectroscopy. The multilayered nanostructural features of the composites and the intimate interactions between PANI and RGO are evidenced by field emission scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. Increasing the RGO fraction in the composites results in a relaxation process observed at a frequency of ca. 5 kHz. This mechanism is associated with an electrical charge trapping phenomenon occurring at the PANI/RGO interfaces. The dielectric relaxation processes are interpreted according to the Sillars approach and the results are consistent with the presence ofmore » conducting prolate spheroids (RGO) embedded into a polymeric matrix (PANI). Dielectric permittivity data are analyzed within the framework of the Kohlrausch-William-Watts model, evidencing a Debye-like relaxation process.« less

  6. Involvement of the glucose moiety in the molecular recognition of methyl beta-lactoside by ricin: synthesis, conformational analysis, and binding studies of different derivatives at the C-3 region.

    PubMed

    Fernández, P; Jiménez-Barbero, J; Martín-Lomas, M; Solís, D; Díaz-Mauriño, T

    1994-04-01

    Syntheses of the 3-aminodeoxy (4), 3-deoxy-3-methyl (5), and 3-epi (6) derivatives of methyl beta-lactoside (1) have been achieved from 1 in a straightforward way, and their solution conformations in water and dimethyl sulfoxide analysed through molecular mechanics and dynamics calculations and nuclear magnetic resonance data. The overall shape of all the compounds studied is fairly similar and may be described by conformers included in a low energy region with phi = 15 +/- 45 degrees and psi = -25 +/- 30 degrees, that is ca. 5% of the total potential energy surface for the glycosidic linkages of the disaccharides. The binding of the different compounds to ricin, the galactose-specific toxin from Ricinus communis, has been investigated. The results confirm the involvement of the C-3 region in a nonpolar interaction with the protein at the periphery of the combining site.

  7. Effects of Salts and Metal Oxides on Electrochemical and Optical Properties of Streptococcus mutans

    NASA Astrophysics Data System (ADS)

    Kawai, Tsuyoshi; Nagame, Seigo; Kambara, Masaki; Yoshino, Katsumi

    1994-10-01

    The effects of calcium salts and metal oxide powders on electrochemical, optical and biological properties of Streptococcus mutans have been studied as a novel method to determine the strain. Electrochemical signals of Streptococcus mutans show remarkable decrease in the presence of saturated calcium salts such as CaHPO4, Ca3(PO4)2, and Ca5(PO4)3OH depending on the strains of Streptococcus mutans: Ingbritt, NCTC-10449, or GS-5. The number of viable cells also decreases upon addition of these powders. The effects of metal oxides such as ZnO and BaTiO3 on the electrochemical characteristics and photoluminescence of Streptococcus mutans have also been studied.

  8. Boron carbon nitride nanostructures from salt melts: tunable water-soluble phosphors.

    PubMed

    Lei, Weiwei; Portehault, David; Dimova, Rumiana; Antonietti, Markus

    2011-05-11

    A simple, high yield, chemical process is developed to fabricate layered h-BN nanosheets and BCNO nanoparticles with a diameter of ca. 5 nm at 700 °C. The use of the eutectic LiCl/KCl salt melt medium enhances the kinetics of the reaction between sodium borohydride and urea or guanidine as well as the dispersion of the nanoparticles in water. The carbon content can be tuned from 0 to 50 mol % by adjusting the reactant ratio, thus providing precise control of the light emission of the particles in the range 440-528 nm while reaching a quantum yield of 26%. Because of their green synthesis, low toxicity, small size, and stability against aggregation in water, the as-obtained photoluminescent BCNO nanoparticles show promise for diagnostics and optoelectronics. © 2011 American Chemical Society

  9. Experimental study of noise sources and acoustic propagation in a turbofan model

    NASA Astrophysics Data System (ADS)

    Lewy, S.; Canard-Caruana, S.; Julliard, J.

    1990-10-01

    Experimental studies of the acoustic radiation of subsonic fans mainly due to blade and vane presure fluctuations were performed in the SNECMA 5C2 compressor anechoic facility. A brief description of the test rig is presented noting that the CA5 turbojet engine model fan has a diameter of 47 cm, 48 blades, and a nominal rotation speed of 12,600 rpm. The two chief experiments discussed are the measurement of blade and vane pressure fluctuations by thin-film transducers and the spinning mode analysis of the sound field propagating in the intake duct. Several examples of applications are discussed, and it is shown that an inflow control device, as expected, reduces the aerodynamic disturbances by about 10 dB. Rotor-stator interaction tones are determined by the modal analysis, and it is found that a duct lining with a length of one duct radius could give an insertion loss up to 20 dB in flight.

  10. Luminescence and Excitation Spectra of U 3+ doped RbY 2 Cl 7 Single Crystals

    DOE PAGES

    Karbowiak, M.; Murdoch, K.; Drożdżyński, J.; ...

    1996-08-01

    Uranium(3+) doped single crystals of RbY 2 Cl 7 with a uranium concentration of 0.05% and 0.2% were grown by the Bridgman-Stockbarger method using RbU 2 Cl 7 as the doping substance. Polished plates of ca. 5 mm in diameter were used for measurements of luminescence and excitation spectra. And since the U 3+ ions occupy two somewhat different site symmetries, a splitting of all observed f-f bands was observed. Furthermore, the analysis of the spectra enabled definitively an assignment of 22 crystal field bands for both site symmetries as well as the total crystal field splitting of the groundmore » level, equal to 473 cm -1 and 567 cm -1 for the first and second site symmetry, respectively.« less

  11. Detection of beer spoilage bacteria Pectinatus and Megasphaera with acridinium ester labelled DNA probes using a hybridisation protection assay.

    PubMed

    Paradh, A D; Hill, A E; Mitchell, W J

    2014-01-01

    DNA probes specific for rRNA of selected target species were utilised for the detection of beer spoilage bacteria of the genera Pectinatus and Megasphaera using a hybridisation protection assay (HPA). All the probes were modified during synthesis by addition of an amino linker arm at the 5' end or were internally modified by inserting an amine modified thymidine base. Synthesised probes then were labelled with acridinium ester (AE) and purified using reverse phase HPLC. The internally AE labelled probes were able to detect target RNA within the range of 0.016-0.0032pmol. All the designed probes showed high specificity towards target RNA and could detect bacterial contamination within the range of ca. 5×10(2)1×10(3) CFU using the HPA. The developed assay was also compatible with MRS, NBB and SMMP beer enrichment media, routinely used in brewing laboratories. © 2013 Elsevier B.V. All rights reserved.

  12. Small angle scattering from protein/sugar conjugates

    NASA Astrophysics Data System (ADS)

    Jackson, Andrew; White, John

    2006-11-01

    The Maillard reaction between free amine groups on proteins and sugars is well known. We have examined the effect of the reaction of the casein group of milk proteins with sugars on their nanoscale structure and aggregation. The small angle neutron scattering from beta casein and sodium caseinate and their sugar conjugates have been studied as a function of solution concentration. At high conjugate concentration (greater than ca. 5 mg/ml) the addition of sugar reduces supra-micellar aggregation of the protein whilst at lower concentration, where the protein is expected to be deaggregated already, little effect is seen. Guinier analysis of the scattering data show a radius of gyration of around 75 A˚ for beta casein in solution and around 80 A˚ for the sucrose conjugate.

  13. Elf cites 5 advantages of horizontal drilling

    SciTech Connect

    Not Available

    1984-06-01

    ELF Aquitaine used horizontal drilling during a pilot test program to bring commercial production from its Rospo Mare oil discovery in the Adriatic, which would have been a costly disappointment if drilled by a conventional vertical well bore. Rospo Mare is a large reservoir containing a top column of highly viscous crude underlain by a water column. The company felt that a well bore that penetrated the reservoir vertically would bring early flooding of the oil column and yield only water. By penetrating the reservoir with a horizontal well drilled high in the oil column, the well successfully produced onmore » numerous tests from Oct. 1982 until the end of the test program in 1983. Production was termed excellent, with productivity during tests reportedly reaching ca 15 times the rate produced from nearby vertical wells. However, ELF said the results usually average ca 5 times the usual rate of vertical wells.« less

  14. A fused-ring acceptor unit in d-a copolymers benefits photovoltaic performance.

    PubMed

    Zuo, Chuantian; Cao, Jiamin; Ding, Liming

    2014-08-01

    Pentacyclic lactam acceptor unit TPTI invented by our group is proved to be a good building block for efficient D-A copolymers used in organic solar cells. Here, two D-A copolymers PBTTPTI and PTTTPTI are developed by copolymerizing TPTI with 2,2'-bithiophene (BT) or thieno[3,2-b]thiophene (TT). PBTTPTI and PTTTPTI exhibit good solubility and strong interchain π-π interaction even in dilute solution. They possess deep HOMO levels (ca. -5.3 eV), partial crystallinity, and good hole mobilities. Blending with PC71 BM, PBTTPTI and PTTTPTI give decent power conversion efficiencies (PCE) up to 6.83% and 5.86%, with outstanding fill factors (FF) of 74.3% and 71.3%, respectively. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Nondestructive Testing for Light Aircraft Pavements. Phase II. Development of the Nondestructive Evaluation Methodology.

    DTIC Science & Technology

    1980-11-01

    10 fILIFE =17.NS (1 ?:-2 FIPAGE = I 0 0 IJRPITE’A30 ’TITLE v I). 1=1,P20) A ~4 CA -5 FORMAT �’ 1lH0.5H**o.n.20A4) A) 0 A IRTE’f6.- 351 ) A...G’ 01: SELECTA: FI4VEVAL 0: 0’.: MOTE: PAVEVFiL 090 :1: EXECUTE 10 01.: L 1111 TS: 30, (O , 15 000 II:,PTPF IA a-0 KIP SINGSLE LINE 1 1a0 1 LINE 2 I...e .. m 4 4 -. -n Ev.i caC C;v C C m44 IO 4 4 dc ca x Ucc 4z ar. La 2.. Vv W a. .4 L. n 1 a a V4 10 ..- Lu k W #.- ALo~~ 2. -C9- P40 - -P40 %. .4 .40

  16. AUTORADIOGRAPHIC LOCALIZATION OF 13N AFTER FIXATION OF 13N-LABELED NITROGEN GAS BY A HETEROCYST-FORMING BLUE-GREEN ALGA

    PubMed Central

    Wolk, C. Peter; Austin, Sam M.; Bortins, John; Galonsky, Aaron

    1974-01-01

    13N, generated by proton bombardment of 13C powder, is rapidly and easily converted to 13N-N2, 0.01 atm pressure, ca. 10 mCi/ml, by automated Dumas combustion. 13N fixed (as 13N-N2) by algal filaments was localized by an autoradiographic technique which permits track autoradiography with isotopes having short half-lives. Our findings show directly that a minimum of about 25% of the N2 fixation by intact, aerobically grown filaments of Anabaena cylindrica is carried out by the heterocysts. If all of the N2 fixation takes place in the heterocysts, then the movement of nitrogen along the filaments can be characterized by a constant τ < ca. 5 s (cell-2). PMID:4208073

  17. Optofluidic refractive index sensor based on partial reflection

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Zhang, Zhang; Wang, Yichuan; Ye, Meiying; Fang, Wei; Tong, Limin

    2017-06-01

    We demonstrate a novel optofluidic refractive index (RI) sensor with high sensitivity and wide dynamic range based on partial reflection. Benefited from the divergent incident light and the output fibers with different tilting angles, we have achieved highly sensitive RI sensing in a wide range from 1.33 to 1.37. To investigate the effectiveness of this sensor, we perform a measurement of RI with a resolution of ca. 5.0×10-5 refractive index unit (RIU) for ethylene glycol solutions. Also, we have measured a series of liquid solutions by using different output fibers, achieving a resolution of ca. 0.52 mg/mL for cane surge. The optofluidic RI sensor takes advantage of the high sensitivity, wide dynamic range, small footprint, and low sample consumption, as well as the efficient fluidic sample delivery, making it useful for applications in the food industry.

  18. Slab rollback orogeny in the Alps and evolution of the Swiss Molasse basin

    PubMed Central

    Schlunegger, Fritz; Kissling, Edi

    2015-01-01

    The stratigraphies of foreland basins have been related to orogeny, where continent–continent collision causes the construction of topography and the downwarping of the foreland plate. These mechanisms have been inferred for the Molasse basin, stretching along the northern margin of the European Alps. Continuous flexural bending of the subducting European lithosphere as a consequence of topographic loads alone would imply that the Alpine topography would have increased at least between 30 Ma and ca. 5–10 Ma when the basin accumulated the erosional detritus. This, however, is neither consistent with observations nor with isostatic mass balancing models because paleoaltimetry estimates suggest that the topography has not increased since 20 Ma. Here we show that a rollback mechanism for the European plate is capable of explaining the construction of thick sedimentary successions in the Molasse foreland basin where the extra slab load has maintained the Alpine surface at low, but constant, elevations. PMID:26472498

  19. Comparison of Envisat ASAR GM, AMSR-E Passive Microwave, and MODIS Optical Remote Sensing for Flood Monitoring in Australia

    NASA Astrophysics Data System (ADS)

    Ticehurst, C. J.; Bartsch, A.; Doubkova, M.; van Dijk, A. I. J. M.

    2009-11-01

    Continuous flood monitoring can support emergency response, water management and environmental monitoring. Optical sensors such as MODIS allow inundation mapping with high spatial and temporal resolution (250-1000 m, twice daily) but are affected by cloud cover. Passive microwave sensors also acquire observations at high temporal resolution, but coarser spatial resolution (e.g. ca. 5-70 km for AMSR-E) and smaller footprints are also affected by cloud and/or rain. ScanSAR systems allow all-weather monitoring but require spatial resolution to be traded off against coverage and/or temporal resolution; e.g. the ENVISAT ASAR Global Mode observes at ca. 1 km over large regions about twice a week. The complementary role of the AMSR-E and ASAR GM data to that of MODIS is here introduced for three flood events and locations across Australia. Additional improvements can be made by integrating digital elevation models and stream flow gauging data.

  20. Pliocene environments

    USGS Publications Warehouse

    Poore, R.Z.

    2007-01-01

    The Pliocene spans the interval of Earth history from ca. 5.3 to 1.8 million years ago (Ma). Although details are still debated there is much evidence from continental and oceanic locations indicating that conditions from 5.3 to about 3.0 Ma were often warmer than in modern times in mid- and high latitudes and that climate variability was subdued compared to the Pleistocene. Millennial-scale early Pliocene climate records are dominated by 19–21 thousand years ago (ka) oscillations. Starting at about 3.0 Ma, a long-term trend toward climate cooling and the ice ages of the Pleistocene accelerated. Significant build-up of Northern Hemisphere ice sheets began around 2.9 Ma and climate variability as measured by the oxygen isotope record in deep-sea carbonate microfossils increased. Distinct glacial–interglacial cycles developed in the late Pliocene between 2.9 and 2.7 Ma.

  1. Molecular Biology of STLV-III and HTLV-IV

    DTIC Science & Technology

    1990-08-22

    8217 AT( ACCA CTCAT.(3CA 5 Ci.T G,- .... ; . , P P, ( L D O S H s v H I -U" G r L "S " V " " , 3 E E 7 ’ T - ’ ’ ’ TJ - " t f? I f T G A- C-. C .T ’ CA8C P...R S N T V K N S D’ . Y S T m 2: G ! Y ’) V V G v I L L R 7 V T Y I’ ,9 M 3: i E F M C f7 E e I V C? iT C? e S . (N*’ 1 . Flist 5At(3CTAGC’’TAATGrAG

  2. Synthesis and interface structures of zinc sulfide sheathed zinc-cadmium nanowire heterojunctions.

    PubMed

    Shen, Guozhen; Bando, Yoshio; Gao, Yihua; Golberg, Dmitri

    2006-07-27

    Zinc sulfide (ZnS) sheathed zinc (Zn)-cadmium (Cd) nanowire heterojunctions have been prepared by thermal evaporating of ZnS and CdS powders in a vertical induction furnace at 1200 degrees C. Studies found that both the Zn and Cd subnanowires, within a single nanoheterojunction, are single-crystallines with the growth directions perpendicular to the [210] plane, whereas the sheathed ZnS is polycrystalline with a thickness of ca. 5 nm. The Zn/Cd interface structure in the ZnS sheathed Zn-Cd nanowire heterojunctions was thoroughly experimentally studied by high-resolution transmission electron microscopy and theoretically studied using a near-coincidence site lattice (NCSL) concept. The results show that the Cd and Zn have a crystalline orientation relationship as [0001]Zn//[0001]Cd, (10(-)10)Zn//(10(-)10)Cd, (01(-)10)Zn//(01(-)10)Cd, and ((-)1100)Zn//((-)1100)Cd.

  3. Molecular taxonomy, phylogeny and evolution in the family Stichopodidae (Aspidochirotida: Holothuroidea) based on COI and 16S mitochondrial DNA.

    PubMed

    Byrne, Maria; Rowe, Frank; Uthicke, Sven

    2010-09-01

    The Stichopodidae comprise a diverse assemblage of holothuroids most of which occur in the Indo-Pacific. Phylogenetic analyses of mitochondrial gene (COI, 16S rRNA) sequence for 111 individuals (7 genera, 17 species) clarified taxonomic uncertainties, species relationships, biogeography and evolution of the family. A monophyly of the genus Stichopus was supported with the exception of Stichopus ellipes. Molecular analyses confirmed genus level taxonomy based on morphology. Most specimens harvested as S. horrens fell in the S. monotuberculatus clade, a morphologically variable assemblage with others from the S. naso clade. Taxonomic clarification of species fished as S. horrens will assist conservation measures. Evolutionary rates based on comparison of sequence from trans-ithmian Isostichopus species estimated that Stichopus and Isostichopus diverged ca. 5.5-10.7Ma (Miocene). More recent splits were estimated to be younger than 1Ma. Copyright 2010 Elsevier Inc. All rights reserved.

  4. Isotopically exchangeable organic hydrogen in coal relates to thermal maturity and maceral composition

    USGS Publications Warehouse

    Mastalerz, Maria; Schimmelmann, A.

    2002-01-01

    Hydrogen isotopic exchangeability (Hex) and ??Dn values of non-exchangeable organic hydrogen were investigated in coal kerogens ranging in rank from lignite to graphite. The relative abundance of Hex is highest in lignite with about 18% of total hydrogen being exchangeable, and decreases to around 2.5% in coals with Ro of 1.7 to ca. 5.7%. At Still higher rank (Ro > 6%), Hex increases slightly, although the abundance of total hydrogen decreases. ??Dn is influenced by original biochemical D/H ratios and by thermal maturation in contact with water. Therefore, ??Dn does not show an overall consistent trend with maturity. ?? 2002 Elsevier Science Ltd. All rights reserved.

  5. 2D/0D graphene hybrids for visible-blind flexible UV photodetectors.

    PubMed

    Tetsuka, Hiroyuki

    2017-07-17

    Nitrogen-functionalized graphene quantum dots (NGQDs) are attractive building blocks for optoelectronic devices because of their exceptional tunable optical absorption and fluorescence properties. Here, we developed a high-performance flexible NGQD/graphene field-effect transistor (NGQD@GFET) hybrid ultraviolet (UV) photodetector, using dimethylamine-functionalized GQDs (NMe 2 -GQDs) with a large bandgap of ca. 3.3 eV. The NMe 2 -GQD@GFET photodetector exhibits high photoresponsivity and detectivity of ca. 1.5 × 10 4  A W -1 and ca. 5.5 × 10 11 Jones, respectively, in the deep-UV region as short as 255 nm without application of a backgate voltage. The feasibility of these flexible UV photodetectors for practical application in flame alarms is also demonstrated.

  6. On the densification and hydration of CaCO3 particles by Q-switched laser pulses in water

    NASA Astrophysics Data System (ADS)

    Lin, Peng-Wen; Wu, Chao-Hsien; Zheng, Yuyuan; Chen, Shuei-Yuan; Shen, Pouyan

    2013-09-01

    Calcite powders subjected to Q-switched laser pulses in water were characterized by X-ray/electron diffraction and optical spectroscopy to have a significant internal compressive stress (up to ca. 1.5 GPa) with accompanied transformation into defective calcite II and hydrates. The defective calcite II particles were (0 1 0), (0 0 1), (0 1¯ 1), (0 1 3) and (0 1¯ 3) faceted with 2×(0 2 0)II commensurate superstructure and tended to hydrate epitaxially as monohydrocalcite co-existing with ikaite (CaCO3·6H2O) with extensive cleavages and amorphous calcium carbonate with porous structure. The colloidal suspension containing the densified calcite polymorphs and hydrates showed two UV-visible absorptions corresponding to a minimum band gap of ca. 5 and 3 eV, respectively.

  7. Dimeric molecular association of dimethyl sulfoxide in solutions of nonpolar liquids.

    PubMed

    Shikata, Toshiyuki; Sugimoto, Natsuki

    2012-01-26

    Although many vibrational spectroscopic studies using infrared (IR) absorption and Raman scattering (RS) techniques revealed that dimethyl sulfoxide (DMSO) forms intermolecular dimeric associations in the pure liquid state and in solutions, the results of a number of dielectric relaxation studies did not clearly show the presence of such dimers. Recently, we found the presence of dimeric DMSO associations in not only the pure liquid but also in solutions of nonpolar solvents, such as tetrachloromethane (CCl(4)) and benzene (Bz), using dielectric relaxation (DR) techniques, which ranged from 50 MHz to 50 GHz at 25 °C. The dimeric DMSO associations cause a slow dielectric relaxation process with a relaxation time of ca. 23 ps for solutions in CCl(4) (ca. 17 ps in Bz) due to the dissociation into monomeric DMSO molecules, while the other fast relaxation is caused by monomeric DMSO molecules with a relaxation time of ca. 5.0 ps (ca. 5.5 ps in Bz) at 25 °C. A comparison of DR and vibrational spectroscopic data for DMSO solutions demonstrated that the concentration dependence of the relative magnitude of the slow and fast DR strength corresponds well to the two IR and RS bands assigned to the vibrational stretching modes of the sulfoxide groups (S═O) of the dimeric associations and the monomeric DMSO molecules, respectively. Moreover, the concentrations of the dimeric associations ([DIM]) and monomeric DMSO molecules ([MON]) were governed by a chemical equilibrium and an equilibrium constant (K(d) = [DIM](2)[MON](-1)) that was markedly dependent on the concentration of DMSO and the solvent species (K(d) = 2.5 ± 0.5 M(-1) and 0.7 ± 0.1 M(-1) in dilute CCl(4) and Bz solutions, respectively, and dramatically increased to 20-40 M(-1) in pure DMSO at 25 °C).

  8. Charge-transfer cross sections in collisions of ground-state Ca and H+

    NASA Astrophysics Data System (ADS)

    Dutta, C. M.; Oubre, C.; Nordlander, P.; Kimura, M.; Dalgarno, A.

    2006-03-01

    We have investigated collisions of Ca(4s2) with H+ in the energy range of 200eV/u-10keV/u using the semiclassical molecular-orbital close-coupling (MOCC) method with 18 coupled molecular states ( 11Σ+1 and seven Π+1 states) to determine charge-transfer cross sections. Except for the incoming channel 6Σ+1 , the molecular states all correspond to charge-transfer channels. Inclusion of Ca2+-H- is crucial in the configuration-interaction calculation for generating the molecular wave functions and potentials. Because of the Coulomb attraction, the state separating to Ca2+-H- creates many avoided crossings, even though at infinite separation it lies energetically above all other states that we included. Because of the avoided crossings between the incoming channel 6Σ+1 and the energetically close charge-transfer channel 7Σ+1 the charge-transfer interaction occurs at long range. This makes calculations of charge-transfer cross sections by the MOCC method very challenging. The total charge-transfer cross sections increase monotonically from 3.4×10-15cm2 at 200eV/u to 4.5×10-15cm2 at 10keV/u . Charge transfer occurs mostly to the excited Ca+(5p) state in the entire energy range, which is the sum of the charge transfer to 7Σ+1 and 4Π+1 . It accounts for ˜47% of the total charge transfer cross sections at 200eV/u . However, as the energy increases, transfer to Ca+(4d) increases, and at 10keV/u the charge-transfer cross sections for Ca+(5p) and Ca+(4d) become comparable, each giving ˜38% of the total cross section.

  9. Contractile properties of muscle fibers from the deep and superficial digital flexors of horses.

    PubMed

    Butcher, M T; Chase, P B; Hermanson, J W; Clark, A N; Brunet, N M; Bertram, J E A

    2010-10-01

    Equine digital flexor muscles have independent tendons but a nearly identical mechanical relationship to the main joint they act upon. Yet these muscles have remarkable diversity in architecture, ranging from long, unipennate fibers ("short" compartment of DDF) to very short, multipennate fibers (SDF). To investigate the functional relevance of the form of the digital flexor muscles, fiber contractile properties were analyzed in the context of architecture differences and in vivo function during locomotion. Myosin heavy chain (MHC) isoform fiber type was studied, and in vitro motility assays were used to measure actin filament sliding velocity (V(f)). Skinned fiber contractile properties [isometric tension (P(0)/CSA), velocity of unloaded shortening (V(US)), and force-Ca(2+) relationships] at both 10 and 30°C were characterized. Contractile properties were correlated with MHC isoform and their respective V(f). The DDF contained a higher percentage of MHC-2A fibers with myosin (heavy meromyosin) and V(f) that was twofold faster than SDF. At 30°C, P(0)/CSA was higher for DDF (103.5 ± 8.75 mN/mm(2)) than SDF fibers (81.8 ± 7.71 mN/mm(2)). Similarly, V(US) (pCa 5, 30°C) was faster for DDF (2.43 ± 0.53 FL/s) than SDF fibers (1.20 ± 0.22 FL/s). Active isometric tension increased with increasing Ca(2+) concentration, with maximal Ca(2+) activation at pCa 5 at each temperature in fibers from each muscle. In general, the collective properties of DDF and SDF were consistent with fiber MHC isoform composition, muscle architecture, and the respective functional roles of the two muscles in locomotion.

  10. A two-pronged structural analysis of retroviral maturation indicates that core formation proceeds by a disassembly-reassembly pathway rather than a displacive transition.

    PubMed

    Keller, Paul W; Huang, Rick K; England, Matthew R; Waki, Kayoko; Cheng, Naiqian; Heymann, J Bernard; Craven, Rebecca C; Freed, Eric O; Steven, Alasdair C

    2013-12-01

    Retrovirus maturation involves sequential cleavages of the Gag polyprotein, initially arrayed in a spherical shell, leading to formation of capsids with polyhedral or conical morphology. Evidence suggests that capsids assemble de novo inside maturing virions from dissociated capsid (CA) protein, but the possibility persists of a displacive pathway in which the CA shell remains assembled but is remodeled. Inhibition of the final cleavage between CA and spacer peptide SP1/SP blocks the production of mature capsids. We investigated whether retention of SP might render CA assembly incompetent by testing the ability of Rous sarcoma virus (RSV) CA-SP to assemble in vitro into icosahedral capsids. Capsids were indeed assembled and were indistinguishable from those formed by CA alone, indicating that SP was disordered. We also used cryo-electron tomography to characterize HIV-1 particles produced in the presence of maturation inhibitor PF-46396 or with the cleavage-blocking CA5 mutation. Inhibitor-treated virions have a shell that resembles the CA layer of the immature Gag shell but is less complete. Some CA protein is generated but usually not enough for a mature core to assemble. We propose that inhibitors like PF-46396 bind to the Gag lattice where they deny the protease access to the CA-SP1 cleavage site and prevent the release of CA. CA5 particles, which exhibit no cleavage at the CA-SP1 site, have spheroidal shells with relatively thin walls. It appears that this lattice progresses displacively toward a mature-like state but produces neither conical cores nor infectious virions. These observations support the disassembly-reassembly pathway for core formation.

  11. Microbial fuel cells for clogging assessment in constructed wetlands.

    PubMed

    Corbella, Clara; García, Joan; Puigagut, Jaume

    2016-11-01

    Clogging in HSSF CW may result in a reduction of system's life-span or treatment efficiency. Current available techniques to assess the degree of clogging in HSSF CW are time consuming and cannot be applied on a continuous basis. Main objective of this work was to assess the potential applicability of microbial fuel cells for continuous clogging assessment in HSSF CW. To this aim, two replicates of a membrane-less microbial fuel cell (MFC) were built up and operated under laboratory conditions for five weeks. The MFC anode was gravel-based to simulate the filter media of HSSF CW. MFC were weekly loaded with sludge that had been accumulating for several years in a pilot HSSF CW treating domestic wastewater. Sludge loading ranged from ca. 20kgTS·m(-3)CW·year(-1) at the beginning of the study period up to ca. 250kgTS·m(-3)CW·year(-1) at the end of the study period. Sludge loading applied resulted in sludge accumulated within the MFC equivalent to a clogging degree ranging from 0.2years (ca. 0.5kgTS·m(-3)CW) to ca. 5years (ca. 10kgTS·m(-3)CW). Results showed that the electric charge was negatively correlated to the amount of sludge accumulated (degree of clogging). Electron transference (expressed as electric charge) almost ceased when accumulated sludge within the MFC was equivalent to ca. 5years of clogging (ca. 10kgTS·m(-3)CW). This result suggests that, although longer study periods under more realistic conditions shall be further performed, HSSF CW operated as a MFC has great potential for clogging assessment. Copyright © 2016. Published by Elsevier B.V.

  12. Montreal Cognitive Assessment: One Cutoff Never Fits All.

    PubMed

    Wong, Adrian; Law, Lorraine S N; Liu, Wenyan; Wang, Zhaolu; Lo, Eugene S K; Lau, Alexander; Wong, Lawrence K S; Mok, Vincent C T

    2015-12-01

    The objective of this study is to examine the discrepancy between single versus age and education corrected cutoff scores in classifying performance on the Montreal Cognitive Assessment (MoCA) in patients with stroke or transient ischemic attack. MoCA norms were collected from 794 functionally independent and stroke- and dementia-free persons aged ≥65 years. magnetic resonance imaging was used to exclude healthy controls with significant brain pathology and medial temporal lobe atrophy. Cutoff scores at 16th, 7th, and 2nd percentiles by age and education were derived for the MoCA and MoCA 5-minute Protocol. MoCA performance in 919 patients with stroke or transient ischemic attack was classified using the single and norm-derived cutoff scores. The norms for the Hong Kong version of the MoCA total and domain scores and the total score of the MoCA 5-minute protocol are described. Only 65.1% and 25.7% healthy controls and 45.2% and 19.0% patients scored above the conventional cutoff scores of 21/22 and 25/26 on the MoCA. Using classification with norm-derived cutoff scores as reference, locally derived cutoff score of 21/22 yielded a classification discrepancy of ≤42.4%. Discrepancy increased with higher age and lower education level, with the majority being false positives by single cutoffs. With the 25/26 cutoff of the original MoCA, discrepancy further increased to ≤74.3%. Conventional single cutoff scores are associated with substantially high rates of misclassification especially in older and less-educated patients with stroke. These results caution against the use of one-size-fits-all cutoffs on the MoCA. © 2015 American Heart Association, Inc.

  13. Cosensitization of Structurally Simple Porphyrin and Anthracene-Based Dye for Dye-Sensitized Solar Cells.

    PubMed

    Reddy, Kamani Sudhir K; Chen, Yen-Chiao; Wu, Chih-Chung; Hsu, Chia-Wei; Chang, Ya-Ching; Chen, Chih-Ming; Yeh, Chen-Yu

    2018-01-24

    Since their introduction, dye-sensitized solar cells (DSCs) have achieved huge success at a laboratory level. Recently, research is concentrated to visualize large DSC modules at the commercial platform. In that aspect, we have tested structurally simple porphyrin-based dye SK6 and anthracene-based dye CW10 for DSCs application under simulated 1 sun (AM 1.5G) and indoor light sources. These two dyes can be easily synthesized and yet are efficient with cell performances of ca. 5.42% and ca. 5.75% (without coadsorbent/additive) for SK6 and CW10, respectively, under AM 1.5G illumination. The power conversion efficiency (PCE) of SK6 reported in this work is the highest ever reported; this is achieved by optimizing the adsorption of SK6 on TiO 2 photoanode using the most suitable solvent and immersion period. Cosensitization of SK6 with CW10 on TiO 2 surface has boosted cell performance further and achieved PCE of ca. 6.31% under AM 1.5G illumination. Charge-transfer properties of individual and cosensitized devices at TiO 2 /dye/electrolyte interface were examined via electrochemical impedance spectroscopy. To understand the cell performances under ambient light conditions, we soaked individual and cosensitized devices under T5 and light-emitting diode light sources in the range of 300-6000 lx. The PCE of ca. 22.91% under T5 light (6000 lx) with J SC = 0.883 mA cm -2 , V OC = 0.646 V, and FF = 0.749 was noted for the cosensitized device, which equals a power output of 426 μW cm -2 . These results reveal that DSCs made of structurally simple dyes performed efficiently under both 1 sun (AM 1.5G) and indoor light conditions, which is undoubtedly a significant achievement when it comes to a choice of commercial application.

  14. Hypotensive and vasorelaxant effects of citronellol, a monoterpene alcohol, in rats.

    PubMed

    Bastos, Joana F A; Moreira, Italo J A; Ribeiro, Thaís P; Medeiros, Isac A; Antoniolli, Angelo R; De Sousa, Damião P; Santos, Márcio R V

    2010-04-01

    Citronellol is an essential oil constituent from the medicinal plants Cymbopogon citratus, Cymbopogon winterianus and Lippia alba which are thought to possess antihypertensive properties. Citronellol-induced cardiovascular effects were evaluated in this study. In rats, citronellol (1-20 mg/kg, i.v.) induced hypotension, which was not affected by pre-treatment with atropine, hexamethonium, N(omega)-nitro-L-arginine methyl ester hydrochloride or indomethacin, and tachycardia, which was only attenuated by pre-treatment with atropine and hexamethonium. These responses were less than those obtained for nifedipine, a reference drug. In intact rings of rat mesenteric artery pre-contracted with 10 microM phenylephrine, citronellol induced relaxations (pD(2) = 0.71 +/- 0.11; E(max) = 102 +/- 5%; n = 6) that were not affected by endothelium removal, after tetraethylamonium in rings without endothelium pre-contracted with KCl 80 mM. Citronellol strongly antagonized (maximal inhibition = 97 +/- 4%; n = 6) the contractions induced by CaCl(2) (10(-6) to 3 x 10(-3 )M) and did not induce additional effects on the maximal response of nifedipine (10 microM). Finally, citronellol inhibited the contractions induced by 10 microM phenylephrine or 20 mM caffeine. The present results suggest that citronellol lowers blood pressure by a direct effect on the vascular smooth muscle leading to vasodilation.

  15. Intercrossed carbon nanorings with pure surface states as low-cost and environment-friendly phosphors for white-light-emitting diodes.

    PubMed

    Li, Xiaoming; Liu, Yanli; Song, Xiufeng; Wang, Hao; Gu, Haoshuang; Zeng, Haibo

    2015-02-02

    As an important energy-saving technique, white-light-emitting diodes (W-LEDs) have been seeking for low-cost and environment-friendly substitutes for rare-earth-based expensive phosphors or Pd(2+)/Cd(2+)-based toxic quantum dots (QDs). In this work, precursors and chemical processes were elaborately designed to synthesize intercrossed carbon nanorings (IC-CNRs) with relatively pure hydroxy surface states for the first time, which enable them to overcome the aggregation-induced quenching (AIQ) effect, and to emit stable yellow-orange luminescence in both colloidal and solid states. As a direct benefit of such scarce solid luminescence from carbon nanomaterials, W-LEDs with color coordinate at (0.28, 0.27), which is close to pure white light (0.33, 0.33), were achieved through using these low-temperature-synthesized and toxic ion-free IC-CNRs as solid phosphors on blue LED chips. This work demonstrates that the design of surface states plays a crucial role in exploring new functions of fluorescent carbon nanomaterials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. One-step Synthesis of Ordered Pd@TiO2 Nanofibers Array Film as Outstanding NH3 Gas Sensor at Room Temperature.

    PubMed

    Wu, Hongyuan; Huang, Haitao; Zhou, Jiao; Hong, Dahai; Ikram, Muhammad; Rehman, Afrasiab Ur; Li, Li; Shi, Keying

    2017-11-07

    The one dimensional (1D) ordered porous Pd@TiO 2 nanofibers (NFs) array film have been fabricated via a facile one-step synthesis of the electrospinning approach. The Pd@TiO 2 NFs (PTND3) contained Pd (2.0 wt %) and C, N element (16.2 wt %) display high dispersion of Pd nanoparticles (NPs) on TiO 2 NFs. Adding Pd meshed with C, N element to TiO 2 based NFs might contribute to generation of Lewis acid sites and Brønsted acid sites, which have been recently shown to enhance NH 3 adsorption-desorption ability; Pd NPs could increase the quantity of adsorbed O 2 on the surface of TiO 2 based NFs, and accelerated the O 2 molecule-ion conversion rate, enhanced the ability of electron transmission. The response time of PTND3 sensor towards 100 ppm NH 3 is only 3 s at room temperature (RT). Meantime, the response and response time of the PTND3 to the NH 3 is 1 and 14s even at the concentration of 100 ppb. Therefore, the ordered Pd@TiO 2 NFs array NH 3 sensor display great potential for practical applications.

  17. Examination of DSM-5 Section III avoidant personality disorder in a community sample.

    PubMed

    Sellbom, Martin; Carmichael, Kieran L C; Liggett, Jacqueline

    2017-11-01

    The current research evaluated the continuity between DSM-5 Section II and Section III diagnostic operationalizations of avoidant personality disorder (AvPD). More specifically, the study had three aims: (1) to examine which personality constructs comprise the optimal trait constellation for AvPD; (2) to investigate the utility of the proposed structure of the Section III AvPD diagnosis, in regard to combining functional impairment (criterion A) and a dimensional measure of personality (criterion B) variables; and (3) to determine whether AvPD-specific impairment confers incremental meaningful contribution above and beyond general impairment in personality functioning. A mixed sample of 402 university and community participants was recruited, and they were administered multiple measures of Section II PD, personality traits, and personality impairment. A latent measurement model approach was used to analyse data. Results supported the general continuity between Section II and Section III of the DSM-5; however, three of the four main criterion B traits were the stronger predictors. There was also some support for the trait unassertiveness augmenting the criterion B trait profile. The combination of using functional impairment criteria (criterion A) and dimensional personality constructs (criterion B) in operationalizing AvPD was supported; however, the reliance of disorder-specific over general impairment for criterion A was not supported. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  18. [Effects of 2-(p-dimethylaminostyryl) pyridine methycholide (DSPM-Ci) on ECG, left atrium contractivity and on papillary muscle action potentials].

    PubMed

    Jiang, X Y; Zhou, C M; Li, D M; Zhang, K J

    1996-01-01

    The effects of DSPM-Cl on ECG in rats, on the dose-effect curve in guinea pig left atria and on the fast action potential (AP), high-K+ depolarized slow action potential (SAP) in guinea pigs papillary muscle were examined electrophysiologically. DSPM-Cl (2 mg.kg-1) showed significant nagative frequency, negative conductivity effect, and prolonged the PP and PR interval. DSPM-CI (30-50 mumol.L-1) was shown to inhibit left atria contractility and shift the concentration-response curve of Iso and CaCl2 to the right with PD2' values of 4.60 and 4.13, respectively. In addition, DSPM-Cl was found to prolong the duration of action potential 90 (APD90) and effective refractory period (ERP), and decrease the maximal upstroke velocity (Vmax) in K(+)-depolarized guinea pigs papillary muscles. The results suggest that, like verpamil, DSPM-Cl might be a calcium antagonist.

  19. Self-assembled supramolecular hetero-bimetallacycles for anticancer potency via intracellular release

    PubMed Central

    Mishra, Anurag; Lee, Seung Chang; Kaushik, Neha; Cook, Timothy R.; Choi, Eun Ha

    2015-01-01

    Two new tetracationic hetero-bimetallacycles, 4 and 5, have been constructed from an N,N′-bis(4-(pyridin-4-ylethynyl)phenyl)pyridine-2,6-dicarboxamide ligand, 1, and cis-blocked complexes [M(dppf)](OTf)2 (dppf = 1,1′-bis(diphenylphosphino)ferrocene; M = Pd (2), Pt (3)) in CH3NO2/CH2Cl2 (1:1) solvent. Both complexes were isolated with adequate yields as triflate salts and were then characterized using 1H, 13C, and 31P NMR spectroscopy, elemental analysis, UV-Vis spectroscopy, and high-resolution electrospray mass spectrometry (HR-ESMS). The molecular structure of 4 was determined by molecular mechanics force field calculations. The cytotoxic effect of both new complexes were analyzed against T98G (brain tumor), KB (head and neck cancer), SNU-80 (thyroid cancer), and HEK-293 non-malignant cell lines. The cytotoxicity of complexes 4 and 5 were found to be considerably more effective against cancer cells than reference drug cisplatin. Annexin-V/PI staining, caspase-3/-7 activity, reduction in mitochondrial membrane potential justify a significant level of apoptosis in complex treated cells. PMID:25209962

  20. First principles investigations of small bimetallic PdGa clusters as catalysts for hydrogen dissociation

    NASA Astrophysics Data System (ADS)

    Kaul, Indu; Ghosh, Prasenjit

    2017-04-01

    Using first principles density functional theory based calculations, we have studied hydrogen dissociation on sub nanometer bimetallic clusters formed from d-block (Pd) and p-block (Ga) elements in gas phase to explore the feasibility of using them as cheap catalysts for hydrogen dissociation. Our calculations show that the dimers, trimers and tetramers of these clusters are thermodynamically more stable than the pure ones for all Ga concentrations. For a given cluster size, we find that the clusters containing equal amount of Pd and Ga are the most stable ones. In contrast to bulk PdGa, the contribution of Pd-d states to the highest occupied molecular orbitals of the bimetallic clusters are either very small or absent. Study of adsorption of hydrogen molecule on these clusters show that hydrogen binds in an activated form only on the Pd rich clusters. From the calculations of hydrogen dissociation barriers on tetramers of pure Pd, 25% Ga (Pd3Ga) and 50% Ga (Pd2Ga2) we find that Pd3Ga is the most efficient catalyst for hydrogen dissociation with barriers even lower than that on the PdGa surfaces.

  1. Nanostructured PdO Thin Film from Langmuir-Blodgett Precursor for Room-Temperature H2 Gas Sensing.

    PubMed

    Choudhury, Sipra; Betty, C A; Bhattacharyya, Kaustava; Saxena, Vibha; Bhattacharya, Debarati

    2016-07-06

    Nanoparticulate thin films of PdO were prepared using the Langmuir-Blodgett (LB) technique by thermal decomposition of a multilayer film of octadecylamine (ODA)-chloropalladate complex. The stable complex formation of ODA with chloropalladate ions (present in subphase) at the air-water interface was confirmed by the surface pressure-area isotherm and Brewster angle microscopy. The formation of nanocrystalline PdO thin film after thermal decomposition of as-deposited LB film was confirmed by X-ray diffraction and Raman spectroscopy. Nanocrystalline PdO thin films were further characterized by using UV-vis and X-ray photoelectron spectroscopic (XPS) measurements. The XPS study revealed the presence of prominent Pd(2+) with a small quantity (18%) of reduced PdO (Pd(0)) in nanocrystalline PdO thin film. From the absorption spectroscopic measurement, the band gap energy of PdO was estimated to be 2 eV, which was very close to that obtained from specular reflectance measurements. Surface morphology studies of these films using atomic force microscopy and field-emission scanning electron microscopy indicated formation of nanoparticles of size 20-30 nm. These PdO film when employed as a chemiresistive sensor showed H2 sensitivity in the range of 30-4000 ppm at room temperature. In addition, PdO films showed photosensitivity with increase in current upon shining of visible light.

  2. Hydrogen storage and phase transformations in Mg-Pd nanoparticles

    NASA Astrophysics Data System (ADS)

    Callini, E.; Pasquini, L.; Rude, L. H.; Nielsen, T. K.; Jensen, T. R.; Bonetti, E.

    2010-10-01

    Microstructure refinement and synergic coupling among different phases are currently explored strategies to improve the hydrogen storage properties of traditional materials. In this work, we apply a combination of these methods and synthesize Mg-Pd composite nanoparticles by inert gas condensation of Mg vapors followed by vacuum evaporation of Pd clusters. Irreversible formation of the Mg6Pd intermetallic phase takes place upon vacuum annealing, resulting in Mg/Mg6Pd composite nanoparticles. Their hydrogen storage properties are investigated and connected to the undergoing phase transformations by gas-volumetric techniques and in situ synchrotron radiation powder x-ray diffraction. Mg6Pd transforms reversibly into different Mg-Pd intermetallic compounds upon hydrogen absorption, depending on temperature and pressure. In particular, at 573 K and 1 MPa hydrogen pressure, the metal-hydride transition leads to the formation of Mg3Pd and Mg5Pd2 phases. By increasing the pressure to 5 MPa, the Pd-richer MgPd intermetallic is obtained. Upon hydrogen desorption, the Mg6Pd phase is reversibly recovered. These phase transformations result in a specific hydrogen storage capacity associated with Mg-Pd intermetallics, which attain the maximum value of 3.96 wt % for MgPd and influence both the thermodynamics and kinetics of hydrogen sorption in the composite nanoparticles.

  3. Determination of iodine and molybdenum in milk by quadrupole ICP-MS.

    PubMed

    Reid, Helen J; Bashammakh, Abdul A; Goodall, Phillip S; Landon, Mark R; O'Connor, Ciaran; Sharp, Barry L

    2008-03-15

    A reliable method for the determination of iodine and molybdenum in milk samples, using alkaline digestion with tetramethylammonium hydroxide and hydrogen peroxide, followed by quadrupole ICP-MS analysis, has been developed and tested using certified reference materials. The use of He+O2 (1.0 ml min(-1) and 0.6 ml min(-1)) in the collision-reaction cell of the mass spectrometer to remove (129)Xe+-- initially to enable the determination of low levels of 129I--also resulted in the quantitative conversion of Mo(+) to MoO2+ which enabled the molybdenum in the milk to be determined at similar mass to the iodine with the use of Sb as a common internal standard. In order to separate and pre-concentrate iodine at sub microg l(-1) concentrations, a novel method was developed using a cation-exchange column loaded with Pd2+ and Ca2+ ions to selectively retain iodide followed by elution with a small volume of ammonium thiosulfate. This method showed excellent results for aqueous iodide solutions, although the complex milk digest matrix made the method unsuitable for such samples. An investigation of the iodine species formed during oxidation and extraction of milk sample digests was carried out with a view to controlling the iodine chemistry.

  4. Nance-Horan syndrome: localization within the region Xp21.1-Xp22.3 by linkage analysis.

    PubMed

    Stambolian, D; Lewis, R A; Buetow, K; Bond, A; Nussbaum, R

    1990-07-01

    Nance-Horan Syndrome (NHS) or X-linked cataract-dental syndrome (MIM 302350) is a disease of unknown pathogenesis characterized by congenital cataracts and dental anomalies. We performed linkage analysis in three kindreds with NHS by using six RFLP markers between Xp11.3 and Xp22.3. Close linkage was found between NHS and polymorphic loci DXS43 (theta = 0 with lod score 2.89), DXS41 (theta = 0 with lod score 3.44), and DXS67 (theta = 0 with lod score 2.74), defined by probes pD2, p99-6, and pB24, respectively. Recombinations were found with the marker loci DXS84 (theta = .04 with lod score 4.13), DXS143 (theta = .06 with lod score 3.11) and DXS7 (theta = .09 with lod score 1.68). Multipoint linkage analysis determined the NHS locus to be linked completely to DXS41 (lod score = 7.07). Our linkage results, combined with analysis of Xp interstitial deletions, suggest that the NHS locus is located within or close to the Xp22.1-Xp22.2 region.

  5. Nance-Horan syndrome: localization within the region Xp21.1-Xp22.3 by linkage analysis.

    PubMed Central

    Stambolian, D; Lewis, R A; Buetow, K; Bond, A; Nussbaum, R

    1990-01-01

    Nance-Horan Syndrome (NHS) or X-linked cataract-dental syndrome (MIM 302350) is a disease of unknown pathogenesis characterized by congenital cataracts and dental anomalies. We performed linkage analysis in three kindreds with NHS by using six RFLP markers between Xp11.3 and Xp22.3. Close linkage was found between NHS and polymorphic loci DXS43 (theta = 0 with lod score 2.89), DXS41 (theta = 0 with lod score 3.44), and DXS67 (theta = 0 with lod score 2.74), defined by probes pD2, p99-6, and pB24, respectively. Recombinations were found with the marker loci DXS84 (theta = .04 with lod score 4.13), DXS143 (theta = .06 with lod score 3.11) and DXS7 (theta = .09 with lod score 1.68). Multipoint linkage analysis determined the NHS locus to be linked completely to DXS41 (lod score = 7.07). Our linkage results, combined with analysis of Xp interstitial deletions, suggest that the NHS locus is located within or close to the Xp22.1-Xp22.2 region. PMID:1971992

  6. The CJD Neurological Status Scale: A New Tool for Evaluation of Disease Severity and Progression in Creutzfeldt - Jakob disease

    PubMed Central

    Cohen, Oren S.; Prohovnik, Isak; Korczyn, Amos D.; Ephraty, Lilach; Nitsan, Zeev; Tsabari, Rakefet; Appel, Shmuel; Rosenmann, Hanna; Kahana, Ester; Chapman, Joab

    2011-01-01

    Objectives To develop a scale sensitive for the neurological manifestations of Creutzfeldt-Jakob disease (CJD). Methods A 26-item CJD neurological status scale (CJD-NS) was created based on characteristic disease manifestations. Each sign was assigned to one of eight neurological systems to calculate a total scale score (TSS) and a system involvement score (SIS). The scale was administered to 37 CJD patients, 101 healthy first-degree relatives of the patients and 14 elderly patients with Parkinson's disease (PD). Results The mean TSS (±SD) was significantly higher in patients with CJD (13.19±5.63) compared to normal controls (0.41±0.78) and PD patients (9.71±3.05). The mean SIS was also significantly different between the CJD (5.19±1.22) and PD (2.78±1.18 p<0.01) groups reflecting the disseminated nature of neurological involvement in CJD. Using a cutoff of TSS>4 yielded a sensitivity of 97% for CJD, and specificity of 100% against healthy controls. All individual items showed excellent specificity against healthy subjects, but sensitivity was highly variable. Repeat assessments of CJD patients over 3-9 months revealed a time-dependent increase of both the TSS and the SIS reflecting the scale's ability to track disease progression. Conclusions The CJD-NS scale is sensitive to neurological signs and their progression in CJD patients. PMID:21303352

  7. Transferability of polarizable models for ion-water electrostatic interaction

    NASA Astrophysics Data System (ADS)

    Masia, Marco

    2009-06-01

    Studies of ion-water systems at condensed phase and at interfaces have pointed out that molecular and ionic polarization plays an important role for many phenomena ranging from hydrogen bond dynamics to water interfaces' structure. Classical and ab initio Molecular Dynamics simulations reveal that induced dipole moments at interfaces (e.g. air-water and water-protein) are usually high, hinting that polarizable models to be implemented in classical force fields should be very accurate in reproducing the electrostatic properties of the system. In this paper the electrostatic properties of three classical polarizable models for ion-water interaction are compared with ab initio results both at gas and condensed phase. For Li+- water and Cl--water dimers the reproducibility of total dipole moments obtained with high level quantum chemical calculations is studied; for the same ions in liquid water, Car-Parrinello Molecular Dynamics simulations are used to compute the time evolution of ionic and molecular dipole moments, which are compared with the classical models. The PD2-H2O model developed by the author and coworkers [Masia et al. J. Chem. Phys. 2004, 121, 7362] together with the gaussian intermolecular damping for ion-water interaction [Masia et al. J. Chem. Phys. 2005, 123, 164505] showed to be the fittest in reproducing the ab initio results from gas to condensed phase, allowing for force field transferability.

  8. Cooperative catalytic methoxycarbonylation of alkenes: uncovering the role of palladium complexes with hemilabile ligands† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c7sc02964k

    PubMed Central

    Dong, Kaiwu; Sang, Rui; Wei, Zhihong; Liu, Jie; Dühren, Ricarda; Spannenberg, Anke; Jiao, Haijun; Neumann, Helfried; Jackstell, Ralf; Franke, Robert

    2018-01-01

    Mechanistic studies of the catalyst [Pd2(dba)3/1,1′-bis(tert-butyl(pyridin-2-yl)phosphanyl)ferrocene, L2] for olefin alkoxycarbonylation reactions are described. X-ray crystallography reveals the coordination of the pyridyl nitrogen atom in L2 to the palladium center of the catalytic intermediates. DFT calculations on the elementary steps of the industrially relevant carbonylation of ethylene (the Lucite α-process) indicate that the protonated pyridyl moiety is formed immediately, which facilitates the formation of the active palladium hydride complex. The insertion of ethylene and CO into this intermediate leads to the corresponding palladium acyl species, which is kinetically reversible. Notably, this key species is stabilized by the hemilabile coordination of the pyridyl nitrogen atom in L2. The rate-determining alcoholysis of the acyl palladium complex is substantially facilitated by metal–ligand cooperation. Specifically, the deprotonation of the alcohol by the built-in base of the ligand allows a facile intramolecular nucleophilic attack on the acyl palladium species concertedly. Kinetic measurements support this mechanistic proposal and show that the rate of the carbonylation step is zero-order dependent on ethylene and CO. Comparing CH3OD and CH3OH as nucleophiles suggests the involvement of (de)protonation in the rate-determining step. PMID:29732128

  9. A Comparison of Dance Interventions in People with Parkinson Disease and Older Adults

    PubMed Central

    McNeely, ME; Duncan, RP; Earhart, GE

    2015-01-01

    It is important for our aging population to remain active, particularly those with chronic diseases, like Parkinson disease (PD), which limit mobility. Recent studies in older adults and people with PD suggest dance interventions provide various motor benefits. The literature for dance in PD is growing, but many knowledge gaps remain, relative to what is known in older adults. The purpose of this review is to: 1) detail results of dance intervention studies in older adults and in PD, 2) describe limitations of dance research in these populations, and 3) identify directions for future study. Generally, a wide variety of dance styles have been investigated in older adults, while a more limited subset has been evaluated in PD. Measures vary widely across studies and a lack of standardized outcomes measures hinders cross-studies comparisons. Compared to the dance literature in older adults, there is a notable absence of evidence in the PD literature in outcome domains related to cardiovascular health, muscle strength, body composition, flexibility, and proprioception. As a whole, the dance literature supports substantial and wide-ranging benefits in both populations, but additional effort should be dedicated to well-designed comparative studies using standardized outcome measures to identify optimal treatment programs. PMID:25771040

  10. A comparison of dance interventions in people with Parkinson disease and older adults.

    PubMed

    McNeely, M E; Duncan, R P; Earhart, G M

    2015-05-01

    It is important for our aging population to remain active, particularly those with chronic diseases, like Parkinson disease (PD), which limit mobility. Recent studies in older adults and people with PD suggest dance interventions provide various motor benefits. The literature for dance in PD is growing, but many knowledge gaps remain, relative to what is known in older adults. The purpose of this review is to: (1) detail results of dance intervention studies in older adults and in PD, (2) describe limitations of dance research in these populations, and (3) identify directions for future study. Generally, a wide variety of dance styles have been investigated in older adults, while a more limited subset has been evaluated in PD. Measures vary widely across studies and a lack of standardized outcomes measures hinders cross-studies comparisons. Compared to the dance literature in older adults, there is a notable absence of evidence in the PD literature in outcome domains related to cardiovascular health, muscle strength, body composition, flexibility, and proprioception. As a whole, the dance literature supports substantial and wide-ranging benefits in both populations, but additional effort should be dedicated to well-designed comparative studies using standardized outcome measures to identify optimal treatment programs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Association Between Helicobacter pylori Infection and Risk of Periodontal Diseases in Han Chinese: A Case-Control Study

    PubMed Central

    Yang, Jing; Zhang, Qiang; Chen, Ming; Wu, Wu-zhou; Wang, Rong; Liu, Chang-jun; Li, Bei; Shi, Xin-li; Du, Han-song; Tan, Hua-bing

    2016-01-01

    Background This study was performed to test the association between Helicobacter pylori (HP) and periodontal disease (PD). Material/Methods This was a case-control study in a comprehensive hospital, including all patients with newly diagnosed PD between 2012 and 2014 as cases and all patients without PD as controls, thorough periodontal examinations. Those who tested positive for HP were examined by means of polymerase chain reaction. Single and multivariate logistic regression was used to analyze the data using SPSS 19.0 software. Results This case-control study included 212 Han Chinese non-smoking adults. The results indicated that HP-positive status significantly increased the risk of PD (2.63 times higher (odds ratio [OR]=2.63; 95% confidence interval [CI]=1.48–4.67). After adjustment for age, sex, level of education, physical exercise, body mass index, and history of alcohol and diabetes mellitus, this association remained significantly (OR=2.82, 95% CI=1.55–5.13). Conclusions PD might be associated with HP infection in adults and HP infection may be a significant and independent risk factor for PD. PMID:26753766

  12. Product lambda-doublet ratios as an imprint of chemical reaction mechanism

    PubMed Central

    Jambrina, P. G.; Zanchet, A.; Aldegunde, J.; Brouard, M.; Aoiz, F. J.

    2016-01-01

    In the last decade, the development of theoretical methods has allowed chemists to reproduce and explain almost all of the experimental data associated with elementary atom plus diatom collisions. However, there are still a few examples where theory cannot account yet for experimental results. This is the case for the preferential population of one of the Λ-doublet states produced by chemical reactions. In particular, recent measurements of the OD(2Π) product of the O(3P)+D2 reaction have shown a clear preference for the Π(A′) Λ-doublet states, in apparent contradiction with ab initio calculations, which predict a larger reactivity on the A′′ potential energy surface. Here we present a method to calculate the Λ-doublet ratio when concurrent potential energy surfaces participate in the reaction. It accounts for the experimental Λ-doublet populations via explicit consideration of the stereodynamics of the process. Furthermore, our results demonstrate that the propensity of the Π(A′) state is a consequence of the different mechanisms of the reaction on the two concurrent potential energy surfaces PMID:27834381

  13. Effects of stress on heart rate complexity—A comparison between short-term and chronic stress

    PubMed Central

    Schubert, C.; Lambertz, M.; Nelesen, R.A.; Bardwell, W.; Choi, J.-B.; Dimsdale, J.E.

    2009-01-01

    This study examined chronic and short-term stress effects on heart rate variability (HRV), comparing time, frequency and phase domain (complexity) measures in 50 healthy adults. The hassles frequency subscale of the combined hassles and uplifts scale (CHUS) was used to measure chronic stress. Short-term stressor reactivity was assessed with a speech task. HRV measures were determined via surface electrocardiogram (ECG). Because respiration rate decreased during the speech task (p < .001), this study assessed the influence of respiration rate changes on the effects of interest. A series of repeated-measures analyses of covariance (ANCOVA) with Bonferroni adjustment revealed that short-term stress decreased HR D2 (calculated via the pointwise correlation dimension PD2) (p < .001), but increased HR mean (p < .001), standard deviation of R–R (SDRR) intervals (p < .001), low (LF) (p < .001) and high frequency band power (HF) (p = .009). Respiratory sinus arrhythmia (RSA) and LF/HF ratio did not change under short-term stress. Partial correlation adjusting for respiration rate showed that HR D2 was associated with chronic stress (r = −.35, p = .019). Differential effects of chronic and short-term stress were observed on several HRV measures. HR D2 decreased under both stress conditions reflecting lowered functionality of the cardiac pacemaker. The results confirm the importance of complexity metrics in modern stress research on HRV. PMID:19100813

  14. Development of new two-dimensional spectral/spatial code based on dynamic cyclic shift code for OCDMA system

    NASA Astrophysics Data System (ADS)

    Jellali, Nabiha; Najjar, Monia; Ferchichi, Moez; Rezig, Houria

    2017-07-01

    In this paper, a new two-dimensional spectral/spatial codes family, named two dimensional dynamic cyclic shift codes (2D-DCS) is introduced. The 2D-DCS codes are derived from the dynamic cyclic shift code for the spectral and spatial coding. The proposed system can fully eliminate the multiple access interference (MAI) by using the MAI cancellation property. The effect of shot noise, phase-induced intensity noise and thermal noise are used to analyze the code performance. In comparison with existing two dimensional (2D) codes, such as 2D perfect difference (2D-PD), 2D Extended Enhanced Double Weight (2D-Extended-EDW) and 2D hybrid (2D-FCC/MDW) codes, the numerical results show that our proposed codes have the best performance. By keeping the same code length and increasing the spatial code, the performance of our 2D-DCS system is enhanced: it provides higher data rates while using lower transmitted power and a smaller spectral width.

  15. SciTech Connect

    Kerisit, Sebastien N.; Gao, Fei; Xie, YuLong

    This Final Report presents work carried out at Pacific Northwest National Laboratory (PNNL) under the project entitled “Validated Models for Radiation Response and Signal Generation in Scintillators” (Project number: PL10-Scin-theor-PD2Jf) and led by Drs. Fei Gao and Sebastien N. Kerisit. This project was divided into four tasks: 1) Electronic response functions (ab initio data model) 2) Electron-hole yield, variance, and spatial distribution 3) Ab initio calculations of information carrier properties 4) Transport of electron-hole pairs and scintillation efficiency Detailed information on the results obtained in each of the four tasks is provided in this Final Report. Furthermore, published peer-reviewed articlesmore » based on the work carried under this project are included in Appendix. This work was supported by the National Nuclear Security Administration, Office of Nuclear Nonproliferation Research and Development (DNN R&D/NA-22), of the U.S. Department of Energy (DOE).« less

  16. [Functional organization and structure of the serotonergic neuronal network of terrestrial snail].

    PubMed

    Nikitin, E S; Balaban, P M

    2011-01-01

    The extension of knowledge how the brain works requires permanent improvement of methods of recording of neuronal activity and increase in the number of neurons recorded simultaneously to better understand the collective work of neuronal networks and assemblies. Conventional methods allow simultaneous intracellular recording up to 2-5 neurons and their membrane potentials, currents or monosynaptic connections or observation of spiking of neuronal groups with subsequent discrimination of individual spikes with loss of details of the dynamics of membrane potential. We recorded activity of a compact group of serotonergic neurons (up to 56 simultaneously) in the ganglion of a terrestrial mollusk using the method of optical recording of membrane potential that allowed to record individual action potentials in details with action potential parameters and to reveal morphology of the neurons rcorded. We demonstrated clear clustering in the group in relation with the dynamics of action potentials and phasic or tonic components in the neuronal responses to external electrophysiological and tactile stimuli. Also, we showed that identified neuron Pd2 could induce activation of a significant number of neurons in the group whereas neuron Pd4 did not induce any activation. However, its activation is delayed with regard to activation of the reacting group of neurons. Our data strongly support the concept of possible delegation of the integrative function by the network to a single neuron.

  17. Comparison of the catalytic activity for the Suzuki-Miyaura reaction of (η(5)-Cp)Pd(IPr)Cl with (η(3)-cinnamyl)Pd(IPr)(Cl) and (η(3)-1-t-Bu-indenyl)Pd(IPr)(Cl).

    PubMed

    Melvin, Patrick R; Hazari, Nilay; Lant, Hannah M C; Peczak, Ian L; Shah, Hemali P

    2015-01-01

    Complexes of the type (η(3)-allyl)Pd(L)(Cl) and (η(3)-indenyl)Pd(L)(Cl) are highly active precatalysts for the Suzuki-Miyaura reaction. Even though allyl and indenyl ligands are similar to cyclopentadienyl (Cp) ligands, there have been no detailed comparative studies exploring the activity of precatalysts of the type (η(5)-Cp)Pd(L)(Cl) for Suzuki-Miyaura reactions. Here, we compare the catalytic activity of (η(5)-Cp)Pd(IPr)(Cl) (IPr = 1,3-bis(2,6-diisopropylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene, Cp) with two commercially available catalysts (η(3)-cinnamyl)Pd(IPr)(Cl) (Cin) and (η(3)-1-t-Bu-indenyl)Pd(IPr)(Cl) ( (tBu) Ind). We show that Cp gives slightly better catalytic activity than Cin, but significantly inferior activity than (tBu) Ind. This order of activity is rationalized by comparing the rates at which the precatalysts are activated to the monoligated Pd(0) active species along with the tendency of the starting precatalysts to comproportionate with monoligated Pd(0) to form inactive Pd(I) dimers. As part of this work the Cp supported Pd(I) dimer (μ-Cp)(μ-Cl)Pd2(IPr)2 (Cp (Dim) ) was synthesized and crystallographically characterized. It does not readily disproportionate to form monoligated Pd(0) and consequently Cp (Dim) is a poor catalyst for the Suzuki-Miyaura reaction.

  18. Comparison of the catalytic activity for the Suzuki–Miyaura reaction of (η5-Cp)Pd(IPr)Cl with (η3-cinnamyl)Pd(IPr)(Cl) and (η3-1-t-Bu-indenyl)Pd(IPr)(Cl)

    PubMed Central

    Melvin, Patrick R; Lant, Hannah M C; Peczak, Ian L; Shah, Hemali P

    2015-01-01

    Summary Complexes of the type (η3-allyl)Pd(L)(Cl) and (η3-indenyl)Pd(L)(Cl) are highly active precatalysts for the Suzuki–Miyaura reaction. Even though allyl and indenyl ligands are similar to cyclopentadienyl (Cp) ligands, there have been no detailed comparative studies exploring the activity of precatalysts of the type (η5-Cp)Pd(L)(Cl) for Suzuki–Miyaura reactions. Here, we compare the catalytic activity of (η5-Cp)Pd(IPr)(Cl) (IPr = 1,3-bis(2,6-diisopropylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene, Cp) with two commercially available catalysts (η3-cinnamyl)Pd(IPr)(Cl) (Cin) and (η3-1-t-Bu-indenyl)Pd(IPr)(Cl) (tBu Ind). We show that Cp gives slightly better catalytic activity than Cin, but significantly inferior activity than tBu Ind. This order of activity is rationalized by comparing the rates at which the precatalysts are activated to the monoligated Pd(0) active species along with the tendency of the starting precatalysts to comproportionate with monoligated Pd(0) to form inactive Pd(I) dimers. As part of this work the Cp supported Pd(I) dimer (μ-Cp)(μ-Cl)Pd2(IPr)2 (Cp Dim) was synthesized and crystallographically characterized. It does not readily disproportionate to form monoligated Pd(0) and consequently Cp Dim is a poor catalyst for the Suzuki–Miyaura reaction. PMID:26732227

  19. Liquid-phase pulsed laser ablation synthesis of graphitized carbon-encapsulated palladium core-shell nanospheres for catalytic reduction of nitrobenzene to aniline

    NASA Astrophysics Data System (ADS)

    Kim, Yu-jin; Ma, Rory; Reddy, D. Amaranatha; Kim, Tae Kyu

    2015-12-01

    Graphitized carbon-encapsulated palladium (Pd) core-shell nanospheres were produced via pulsed laser ablation of a solid Pd foil target submerged in acetonitrile. The microstructural features and optical properties of these nanospheres were characterized via high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible spectroscopy. Microstructural analysis indicated that the core-shell nanostructures consisted of single-crystalline cubic metallic Pd spheres that serve as the core material, over which graphitized carbon was anchored as a heterogeneous shell. The absorbance spectrum of the synthesized nanostructures exhibited a broad (absorption) band at ∼264 nm; this band corresponded to the typical inter-band transition of a metallic system and resulted possibly from the absorbance of the ionic Pd2+. The catalytic properties of the Pd and Pd@C core-shell nanostructures were investigated using the reduction of nitrobenzene to aniline by an excess amount of NaBH4 in an aqueous solution at room temperature, as a model reaction. Owing to the graphitized carbon-layered structure and the high specific surface area, the resulting Pd@C nanostructures exhibited higher conversion efficiencies than their bare Pd counterparts. In fact, the layered structure provided access to the surface of the Pd nanostructures for the hydrogenation reaction, owing to the synergistic effect between graphitized carbon and the nanostructures. Their unique structure and excellent catalytic performance render Pd@C core-shell nanostructures highly promising candidates for catalysis applications.

  20. Air Launch: Examining Performance Potential of Various Configurations and Growth Options

    NASA Technical Reports Server (NTRS)

    Waters, Eric D.; Creech, Dennis M.; Philips, Alan D.

    2013-01-01

    The Advanced Concepts Office at NASA's George C. Marshall Space Flight Center conducted a high-level analysis of various air launch vehicle configurations, objectively determining maximum launch vehicle payload while considering carrier aircraft capabilities and given dimensional constraints. With the renewed interest in aerial launch of low-earth orbit payloads, referenced by programs such as Stratolaunch and Spaceship2, there exists a need to qualify the boundaries of the trade space, identify performance envelopes, and understand advantages and limiting factors of designing for maximum payload capability. Using the NASA/DARPA Horizontal Launch Study (HLS) Point Design 2 (PD-2) as a pointof- departure configuration, two independent design actions were undertaken. Both designs utilized a Boeing 747-400F as the carrier aircraft, LOX/RP-1 first stage and LOX/LH2 second stage. Each design was sized to meet dimensional and mass constraints while optimizing propellant loads and stage delta V splits. All concepts, when fully loaded, exceeded the allowable Gross Takeoff Weight (GTOW) of the aircraft platform. This excess mass was evaluated as propellant/fuel offload available for a potential in-flight propellant loading scenario. Results indicate many advantages such as payload delivery of approximately 47,000 lbm and significant mission flexibility including variable launch site inclination and launch window. However, in-flight cryogenic fluid transfer and carrier aircraft platform integration are substantial technical hurdles to the realization of such a system configuration.

  1. Air Launch: Examining Performance Potential of Various Configurations and Growth Options

    NASA Technical Reports Server (NTRS)

    Waters, Eric D.; Creech, Dennis M.; Philips, Alan

    2013-01-01

    The Advanced Concepts Office at NASA's George C. Marshall Space Flight Center conducted a high-level analysis of various air launch vehicle configurations, objectively determining maximum launch vehicle payload while considering carrier aircraft capabilities and given dimensional constraints. With the renewed interest in aerial launch of low-earth orbit payloads, referenced by programs such as Stratolaunch and Spaceship2, there existed a need to qualify the boundaries of the trade space, identify performance envelopes, and understand advantages and limiting factors of designing for maximum payload capability. Using the NASA/DARPA Horizontal Launch Study (HLS) Point Design 2 (PD-2) as a point-of-departure configuration, two independent design actions were undertaken. Both configurations utilized a Boeing 747-400F as the carrier aircraft, LOX/RP-1 first stage and LOX/LH2 second stage. Each design was sized to meet dimensional and mass constraints while optimizing propellant loads and stage delta V (?V) splits. All concepts, when fully loaded, exceeded the allowable Gross Takeoff Weight (GTOW) of the aircraft platform. This excess mass was evaluated as propellant/fuel offload available for a potential in-flight refueling scenario. Results indicate many advantages such as large, relative payload delivery of approximately 47,000 lbm and significant mission flexibility, such as variable launch site inclination and launch window; however, in-flight cryogenic fluid transfer and carrier aircraft platform integration are substantial technical hurdles to the realization of such a system configuration.

  2. Evaluation of a post-operative pain-like state on motivated behavior in rats: Effects of plantar incision on progressive-ratio food-maintained responding

    PubMed Central

    Warner, Emily; Krivitsky, Rebecca; Cone, Katherine; Atherton, Phillip; Pitre, Travis; Lanpher, Janell; Giuvelis, Denise; Bergquist, Ivy; King, Tamara; Bilsky, Edward J.; Stevenson, Glenn W.

    2015-01-01

    There has been recent interest in characterizing the effects of pain-like states on motivated behaviors in order to quantify how pain modulates goal-directed behavior and the persistence of that behavior. The current set of experiments assessed the effects of an incisional post-operative pain manipulation on food-maintained responding under a progressive-ratio (PR) operant schedule. Independent variables included injury state (plantar incision or anesthesia control) and reinforcer type (grain pellet or sugar pellet); dependent variables were tactile sensory thresholds and response breakpoint. Once responding stabilized on the PR schedule, separate groups of rats received a single ventral hind paw incision or anesthesia (control condition). Incision significantly reduced breakpoints in rats responding for grain, but not sugar. In rats responding for sugar, tactile hypersensitivity recovered within 24 hrs, indicating a faster recovery of incision-induced tactile hypersensitivity compared to rats responding for grain, which demonstrated recovery at PD2. The NSAID analgesic, diclofenac (5.6 mg/kg) completely restored incision-depressed PR operant responding and tactile sensitivity at 3 hr following incision. The PR schedule differentiated between sucrose and grain, suggesting that relative reinforcing efficacy may be an important determinant in detecting pain-induced changes in motivated behavior. PMID:26494422

  3. [Electrochemically reductive dechlorination of chloroform in aqueous medium by codeposited palladium-nickel glassy carbon as cathode].

    PubMed

    Sun, Zhi-Rong; Li, Bao-Hua; Hu, Xiang; Shi, Min; Peng, Yong-Zhen

    2008-05-01

    The electrochemical deposition behaviors of Pd-Ni bimetal on glassy carbon (GC) electrode were studied by means of cyclic voltammetry (CV) based on orthogonal experiments. CV results reveal that Pd-Ni bimetal shows larger hydrogen adsorption peak than that of single Pd or Ni. The mixture of Ni2+ and Pd2+ can get hydrogen adsorption peak of -24.83 mA at - 500 mV (vs Hg/Hg2SO4). Scanning Electron Microscope (SEM) images reveal that nickel addition changes the distributing configuration of Pd microparticles on GC. And the appearance of Pd-Ni bimetal microparticles is distinctly different from that of single Pd and single Ni microparticles. Diameter of Pd-Ni microparticle is bigger than that of Pd microparticle and smaller than that of Ni microparticle. Effects of dechlorination current and time on removal efficiency of chloroform were also studied. The removal efficiency of chloroform increases at higher dechlorination current and longer dechlorination time. It reaches 42.53% when the dechlorination current and time are 0.5 mA and 180 min respectively on Pd-Ni/GC electrode prepared at optimum conditions. It can be envisioned that the removal efficiency of chloroform would increase further at longer dechlorination time.

  4. [Subtypes of mild cognitive impairment in Parkinson's disease and factors predicting its becoming dementia].

    PubMed

    Toribio-Diaz, M Elena; Carod-Artal, Francisco J

    2015-07-01

    Cognitive impairment may appear at the earliest stages in Parkinson's disease (PD). To assess the prevalence of mild cognitive impairment (MCI) and its different subtypes, as transitional stage, is complicated by the lack of consensus diagnostic criteria. To review MCI in PD (MCI-PD), diagnostic criteria and predictive factors of conversion to dementia. Systematic review of articles published in Medline (PubMed) using the combination of keywords 'mild cognitive impairment' and 'Parkinson's disease'. MCI-PD diagnostic criteria published by the Movement Disorders Society are an interesting tool for the diagnosis, in spite they are not validated. Its implementation has the following limitations: 1) the heterogeneity of cognitive deficits described in PD; 2) a variable evolution of cognitive symptoms in PD which difficult the identification of dementia predictors; 3) selection of the more appropriate neuropsychological tests and cut-off points; 4) patient characteristics, disease stage and type of antiparkinsonian treatment. Neuropsychological subtypes, neuroimaging, biomarkers or limitation in some instrumental activities seem to be very sensitive for detecting patients with MCI-PD and increased risk of conversion to dementia.

  5. Synthesis and functional characterization of novel derivatives related to oxotremorine and oxotremorine-M.

    PubMed

    Dallanoce, C; Conti, P; De Amici, M; De Micheli, C; Barocelli, E; Chiavarini, M; Ballabeni, V; Bertoni, S; Impicciatore, M

    1999-08-01

    Two subseries of nonquaternized (5a-10a) and quaternized derivatives (5b-10b) related to oxotremorine and oxotremorine-M were synthesized and tested. The agonist potency at the muscarinic receptor subtypes of the new compounds was estimated in three classical in vitro functional assays: M1 rabbit vas deferens, M2 guinea pig left atrium and M3 guinea pig ileum. In addition, the occurrence of central muscarinic effects was evaluated as tremorigenic activity after intraperitoneal administration in mice. In in vitro tests a nonselective muscarinic activity was exhibited by all the derivatives with potencies values that, in some instances, surpassed those of the reference compounds (i.e. 8b). Functional selectivity was evidenced only for the oxotremorine-like derivative 9a, which behaved as a mixed M3-agonist/M1-antagonist (pD2 = 5.85; pA2 = 4.76, respectively). In in vivo tests non-quaternary compounds were able to evoke central muscarinic effects, with a potency order parallel to that observed in vitro.

  6. Pd-Catalyzed Consecutive C-H Arylation Triggered Cyclotrimerization: Synthesis of Star-shaped Benzotristhiazoles and Benzotrisoxazoles.

    PubMed

    Xu, Zhanqiang; Oniwa, Kazuaki; Kikuchi, Hiromasa; Bao, Ming; Yamamoto, Yoshinori; Jin, Tienan; Terada, Masahiro

    2018-05-18

    Star-shaped π-extended molecules comprising discotic aromatic cores and peripheral π-conjugated arms have attracted significant attention as diverse optoelectronic materials in terms of their large π-surface, tunable self-assembly, enhanced charge transport and fluorescence, and liquid crystallinity. Although many efforts have been made in construction of various aromatic discotic cores, a new class of C3-symmetric star-shaped discotic π-molecules consisting of electron-deficient benzotristhiazole and benzotrisoxazole cores remains unexplored owing to the unachievable synthetic approaches, which are expected to exhibit distinct optoelectronic properties. Herein, we report a novel and highly efficient Pd-catalyzed cyclotrimerization of the functionalized thiazoles or oxazoles for the construction of a new class of discotic molecules of benzotristhiazole and benzotrisoxazole central cores with star-shaped π-conjugated arms. The combination of Pd2(dba)3/XPhos catalyst systems with the 4-bromo-substituted thiazole enables the formation of a sufficiently stable thiazole-Pd species that participates in the subsequent C-H arylations consecutively to form the corresponding cyclic trimer products. This new class of star-shaped discotic π-extended products showed tunable energy levels and high fluorescence quantum yields that make them promising candidates in optoelectronic application. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Postdoctoral program guidelines.

    SciTech Connect

    Teich-McGoldrick, Stephanie; Miller, Andrew W.; Sava, Dorina Florentina

    2012-04-01

    We, the Postdoc Professional Development Program (PD2P) leadership team, wrote these postdoc guidelines to be a starting point for communication between new postdocs, their staff mentors, and their managers. These guidelines detail expectations and responsibilities of the three parties, as well as list relevant contacts. The purpose of the Postdoc Program is to bring in talented, creative people who enrich Sandia's environment by performing innovative R&D, as well as by stimulating intellectual curiosity and learning. Postdocs are temporary employees who come to Sandia for career development and advancement reasons. In general, the postdoc term is 1 year, renewable up tomore » five times for a total of six years. However, center practices may vary; check with your manager. At term, a postdoc may apply for a staff position at Sandia or choose to move to university, industry or another lab. It is our vision that those who leave become long-term collaborators and advocates whose relationships with Sandia have a positive effect upon our national constituency.« less

  8. Differential expression of non-coding RNAs and continuous evolution of the X chromosome in testicular transcriptome of two mouse species.

    PubMed

    Homolka, David; Ivanek, Robert; Forejt, Jiri; Jansa, Petr

    2011-02-14

    Tight regulation of testicular gene expression is a prerequisite for male reproductive success, while differentiation of gene activity in spermatogenesis is important during speciation. Thus, comparison of testicular transcriptomes between closely related species can reveal unique regulatory patterns and shed light on evolutionary constraints separating the species. Here, we compared testicular transcriptomes of two closely related mouse species, Mus musculus and Mus spretus, which diverged more than one million years ago. We analyzed testicular expression using tiling arrays overlapping Chromosomes 2, X, Y and mitochondrial genome. An excess of differentially regulated non-coding RNAs was found on Chromosome 2 including the intronic antisense RNAs, intergenic RNAs and premature forms of Piwi-interacting RNAs (piRNAs). Moreover, striking difference was found in the expression of X-linked G6pdx gene, the parental gene of the autosomal retrogene G6pd2. The prevalence of non-coding RNAs among differentially expressed transcripts indicates their role in species-specific regulation of spermatogenesis. The postmeiotic expression of G6pdx in Mus spretus points towards the continuous evolution of X-chromosome silencing and provides an example of expression change accompanying the out-of-the X-chromosomal retroposition.

  9. Differential Expression of Non-Coding RNAs and Continuous Evolution of the X Chromosome in Testicular Transcriptome of Two Mouse Species

    PubMed Central

    Homolka, David; Ivanek, Robert; Forejt, Jiri; Jansa, Petr

    2011-01-01

    Background Tight regulation of testicular gene expression is a prerequisite for male reproductive success, while differentiation of gene activity in spermatogenesis is important during speciation. Thus, comparison of testicular transcriptomes between closely related species can reveal unique regulatory patterns and shed light on evolutionary constraints separating the species. Methodology/Principal Findings Here, we compared testicular transcriptomes of two closely related mouse species, Mus musculus and Mus spretus, which diverged more than one million years ago. We analyzed testicular expression using tiling arrays overlapping Chromosomes 2, X, Y and mitochondrial genome. An excess of differentially regulated non-coding RNAs was found on Chromosome 2 including the intronic antisense RNAs, intergenic RNAs and premature forms of Piwi-interacting RNAs (piRNAs). Moreover, striking difference was found in the expression of X-linked G6pdx gene, the parental gene of the autosomal retrogene G6pd2. Conclusions/Significance The prevalence of non-coding RNAs among differentially expressed transcripts indicates their role in species-specific regulation of spermatogenesis. The postmeiotic expression of G6pdx in Mus spretus points towards the continuous evolution of X-chromosome silencing and provides an example of expression change accompanying the out-of-the X-chromosomal retroposition. PMID:21347268

  10. The Child-Langmuir laws and cathode sheath in the N2O

    NASA Astrophysics Data System (ADS)

    Lisovskiy, Valeriy; Artushenko, Ekaterina; Yegorenkov, Vladimir

    2013-09-01

    It is established which of the Child-Langmuir collisional laws are most appropriate for describing the cathode sheath in the N2O. At low pressure p < 0 . 3 Torr the Child-Langmuir law version relating to the constant ion mobility. At p > 0 . 75 Torr one has to employ the law version for which it is assumed that ion mean free path within the cathode sheath is constant. In the intermediate pressure range 0 . 3 < p < 0 . 75 Torr neither of the Child-Langmuir law versions gives a correct description of the cathode sheath in the N2O. The ratio of the normal current density to the gas pressure squared J /p2 , the normal voltage drop and the cathode sheath thickness are determined. For the stainless steel cathode they equals to U = 364 V and pd = 2 . 5 Torr .mm. At large N2O pressure the above ratio remains constant and it amounts to J /p2 = 0.44 mA/(cm .Torr)2 for any inter-electrode gap value we studied. On decreasing the N2O pressure the ratio J /p2 increases and for narrow gaps between electrodes it may approach several or even several tens mA/(cm .Torr)2. and Scientific Center of Physical Technologies, Svobody Sq.6, Kharkov, 61022, Ukraine.

  11. Microstructural characterization of annealed U-12Zr-4Pd and U-12Zr-4Pd-5Ln: Investigating Pd as a metallic fuel additive

    NASA Astrophysics Data System (ADS)

    Benson, Michael T.; He, Lingfeng; King, James A.; Mariani, Robert D.

    2018-04-01

    Palladium is being investigated as a potential additive to metallic fuel to control fuel-cladding chemical interaction (FCCI). A primary cause of FCCI is the lanthanide fission products moving to the fuel periphery and interacting with the cladding. This interaction will lead to wastage of the cladding and, given enough time or burn-up, eventually to a cladding breach. The current study is a scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterization of annealed U-12Zr-4Pd and U-12Zr-4Pd-5Ln, where Ln = 53Nd-25Ce-16Pr-6La. The present study shows that Pd preferentially binds the lanthanides over other fuel constituents, which may prevent lanthanide migration and interaction with the cladding during irradiation. The SEM analysis indicates the 1:1 Pd-Ln compound is being formed, while the TEM analysis, due to higher resolution, found the 1:1 compound, as well as Pd-rich compounds Pd2Ln and Pd3Ln2.

  12. Evaluation of a Postoperative Pain-Like State on Motivated Behavior in Rats: Effects of Plantar Incision on Progressive-Ratio Food-Maintained Responding.

    PubMed

    Warner, Emily; Krivitsky, Rebecca; Cone, Katherine; Atherton, Phillip; Pitre, Travis; Lanpher, Janell; Giuvelis, Denise; Bergquist, Ivy; King, Tamara; Bilsky, Edward J; Stevenson, Glenn W

    2015-12-01

    There has been recent interest in characterizing the effects of pain-like states on motivated behaviors in order to quantify how pain modulates goal-directed behavior and the persistence of that behavior. The current set of experiments assessed the effects of an incisional postoperative pain manipulation on food-maintained responding under a progressive-ratio (PR) operant schedule. Independent variables included injury state (plantar incision or anesthesia control) and reinforcer type (grain pellet or sugar pellet); dependent variables were tactile sensory thresholds and response breakpoint. Once responding stabilized on the PR schedule, separate groups of rats received a single ventral hind paw incision or anesthesia (control condition). Incision significantly reduced breakpoints in rats responding for grain, but not sugar. In rats responding for sugar, tactile hypersensitivity recovered within 24 hr, indicating a faster recovery of incision-induced tactile hypersensitivity compared to rats responding for grain, which demonstrated recovery at PD2. The NSAID analgesic, diclofenac (5.6 mg/kg) completely restored incision-depressed PR operant responding and tactile sensitivity at 3 hr following incision. The PR schedule differentiated between sucrose and grain, suggesting that relative reinforcing efficacy may be an important determinant in detecting pain-induced changes in motivated behavior. © 2015 Wiley Periodicals, Inc.

  13. Highly selective and sensitive detection of metal ions and nitroaromatic compounds by an anionic europium(iii) coordination polymer.

    PubMed

    Feyisa Bogale, Raji; Ye, Junwei; Sun, Yuan; Sun, Tongxin; Zhang, Siqi; Rauf, Abdul; Hang, Cheng; Tian, Peng; Ning, Guiling

    2016-07-05

    A luminescent Eu(iii)-based coordination polymer, {[Eu(H2O)5(BTEC)][H(C5H6N2)]·3H2O} () has been synthesized under hydrothermal conditions using 1,2,4,5-benzenetetracarboxylic acid (H4BTEC) as a linker. Compound possesses an anionic zig-zag chain constructed from the BTEC ligands and [EuO4(H2O)5] nodes. The protonated 4-aminopyridine groups as guests are located between chains. exhibits the characteristic sharp emission bands of Eu(3+) at 578, 593, 615, 652 and 693 nm upon excitation at 290 nm. The strong emission of could be quenched effectively by trace amounts of Fe(3+) ions even in the presence of other metal ions including Al(3+), Ca(2+), Cd(2+), Co(2+), Cr(3+), Cu(2+), Fe(2+), K(+), Mg(2+), Mn(2+), Pd(2+) and Zn(2+). Similarly, also exhibits superior selectivity and sensitivity towards 4-nitrophenol (4-NP) compared with other competing interfering analytes, such as 2,4,6-trinitrophenol, 2,6-dinitrotolune, 4-nitrotoluene, nitrobenzene, 1,3-dinitrobenzene, o-xylene, nitromethane, nitropropane, phenol, 4-bromophenol and bromobenzene, through a fluorescence quenching mechanism. The possible fluorescence quenching mechanisms are discussed. Moreover, could be used as a visual fluorescent test paper for selectively detecting trace amounts of Fe(3+) and 4-NP.

  14. Evidence for the Formation of Nitrogen-Rich Platinum and Palladium Nitride Nanoparticles

    DOE PAGES

    Veith, Gabriel M.; Lupini, Andrew R.; Baggetto, Loïc; ...

    2013-12-03

    Here, we report evidence for the formation of nitrogen-rich precious metal nanoparticles (Pt, Pd) prepared by reactive sputtering of the pure metal in a N 2 plasma. The composition of the nanoparticles varies as a function of particle size and growth conditions. For the smallest particles the nitrogen content appears to be as high as 6.7 N atoms for each Pd atom or 5.9 N atoms for each Pt atom whereas bulk films have nominal compositions of Pt 7.3N and Pd 2.5N. The nanoparticles are metastable in air and moisture, slowly decomposing over several years. This paper describes the synthesismore » of these materials along with experimental evidence of the composition, oxidation state, and growth modes. Moreover, the catalytic properties of these N-rich nanoparticles were accessed by rotating disk electrode electrochemical studies, the liquid phase oxidation of benzyl alcohol and gas phase CO oxidation and support the experimental evidence for the materials composition.« less

  15. Liquid/Liquid Interfacial Synthesis of a Click Nanosheet.

    PubMed

    Rapakousiou, Amalia; Sakamoto, Ryota; Shiotsuki, Ryo; Matsuoka, Ryota; Nakajima, Ukyo; Pal, Tigmansu; Shimada, Rintaro; Hossain, Amran; Masunaga, Hiroyasu; Horike, Satoshi; Kitagawa, Yasutaka; Sasaki, Sono; Kato, Kenichi; Ozawa, Takeaki; Astruc, Didier; Nishihara, Hiroshi

    2017-06-22

    A liquid/liquid interfacial synthesis is employed, for the first time, to synthesize a covalent two-dimensional polymer nanosheet. Copper-catalyzed azide-alkyne cycloaddition (CuAAC) between a three-way terminal alkyne and azide at a water/dichloromethane interface generates a 1,2,3-triazole-linked nanosheet. The resultant nanosheet, with a flat and smooth texture, has a maximum domain size of 20 μm and minimum thickness of 5.3 nm. The starting monomers in the organic phase and the copper catalyst in the aqueous phase can only meet at the liquid/liquid interface as a two-dimensional reaction space; this allows them to form the two-dimensional polymer. The robust triazole linkage generated by irreversible covalent-bond formation allows the nanosheet to resist hydrolysis under both acidic and alkaline conditions, and to endure pyrolysis up to more than 300 °C. The coordination ability of the triazolyl group enables the nanosheet to act as a reservoir for metal ions, with an affinity order of Pd 2+ >Au 3+ >Cu 2+ . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Carbon nitride supported Fe2 cluster catalysts with superior performance for alkene epoxidation.

    PubMed

    Tian, Shubo; Fu, Qiang; Chen, Wenxing; Feng, Quanchen; Chen, Zheng; Zhang, Jian; Cheong, Weng-Chon; Yu, Rong; Gu, Lin; Dong, Juncai; Luo, Jun; Chen, Chen; Peng, Qing; Draxl, Claudia; Wang, Dingsheng; Li, Yadong

    2018-06-15

    Sub-nano metal clusters often exhibit unique and unexpected properties, which make them particularly attractive as catalysts. Herein, we report a "precursor-preselected" wet-chemistry strategy to synthesize highly dispersed Fe 2 clusters that are supported on mesoporous carbon nitride (mpg-C 3 N 4 ). The obtained Fe 2 /mpg-C 3 N 4 sample exhibits superior catalytic performance for the epoxidation of trans-stilbene to trans-stilbene oxide, showing outstanding selectivity of 93% at high conversion of 91%. Molecular oxygen is the only oxidant and no aldehyde is used as co-reagent. Under the same condition, by contrast, iron porphyrin, single-atom Fe, and small Fe nanoparticles (ca. 3 nm) are nearly reactively inert. First-principles calculations reveal that the unique reactivity of the Fe 2 clusters originates from the formation of active oxygen species. The general applicability of the synthesis approach is further demonstrated by producing other diatomic clusters like Pd 2 and Ir 2 , which lays the foundation for discovering diatomic cluster catalysts.

  17. High-density Schottky barrier IRCCD sensors for remote sensing applications

    NASA Astrophysics Data System (ADS)

    Elabd, H.; Tower, J. R.; McCarthy, B. M.

    1983-01-01

    It is pointed out that the ambitious goals envisaged for the next generation of space-borne sensors challenge the state-of-the-art in solid-state imaging technology. Studies are being conducted with the aim to provide focal plane array technology suitable for use in future Multispectral Linear Array (MLA) earth resource instruments. An important new technology for IR-image sensors involves the use of monolithic Schottky barrier infrared charge-coupled device arrays. This technology is suitable for earth sensing applications in which moderate quantum efficiency and intermediate operating temperatures are required. This IR sensor can be fabricated by using standard integrated circuit (IC) processing techniques, and it is possible to employ commercial IC grade silicon. For this reason, it is feasible to construct Schottky barrier area and line arrays with large numbers of elements and high-density designs. A Pd2Si Schottky barrier sensor for multispectral imaging in the 1 to 3.5 micron band is under development.

  18. Shortwave infrared 512 x 2 line sensor for earth resources applications

    NASA Astrophysics Data System (ADS)

    Tower, J. R.; Pellon, L. E.; McCarthy, B. M.; Elabd, H.; Moldovan, A. G.; Kosonocky, W. F.; Kalshoven, J. E., Jr.; Tom, D.

    1985-08-01

    As part of the NASA remote-sensing Multispectral Linear Array Program, an edge-buttable 512 x 2 IRCCD line image sensor with 30-micron Pd2Si Schottky-barrier detectors is developed for operation with passive cooling at 120 K in the 1.1-2.5 micron short infrared band. On-chip CCD multiplexers provide one video output for each 512 detector band. The monolithic silicon line imager performance at a 4-ms optical integration time includes a signal-to-noise ratio of 241 for irradiance of 7.2 microwatts/sq cm at 1.65 microns wavelength, a 5000 dynamic range, a modulation transfer function, greater than 60 percent at the Nyquist frequency, and an 18-milliwatt imager chip total power dissipation. Blemish-free images with three percent nonuniformity under illumination and nonlinearity of 1.25 percent are obtained. A five SWIR imager hybrid focal plane was constructed, demonstrating the feasibility of arrays with only a two-detector loss at each joint.

  19. Theoretical studies of structure and selectivity of 5-methyl-4-(2-thiazolylazo) resorcinol as a sensor for metal ions: DFT calculation

    NASA Astrophysics Data System (ADS)

    Thaomola, Sukhontip; Sompech, Supachai

    2018-05-01

    The global minimum optimized structures of the free sensor 5-methyl-4-(2-thiazolylazo) resorcinol (5-Me-TAR) and 5-Me-TAR-Cu2+ complexes in the gas phase have been investigated by using Density Functional Theory (DFT) with the def2-TZVP basis set. To compare the selectivity of 5-Me-TAR for metal ions, the binding energy of 5-Me-TAR with various metal ions (Na+, K+, Mg2+, Ca2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Pd2+, Cd2+ and Hg2+) were calculated at the same level as the theory. Binding energy values of most transition metal ions are lower than alkaline earth metal ions and alkali metal ions, respectively. The 5-Me-TAR sensor shows the highest selectivity with the Cu2+ ion. Moreover, Dependent Density Functional Theory (TDDFT) results confirm that the 5-Me-TAR-Cu2+ complex is stabilized by the sensor to metal charge transfer process. The computational studies suggested that the 5-Me-TAR is suitable for Cu2+ ion detection sensor development.

  20. Increased vocal intensity due to the Lombard effect in speakers with Parkinson's disease: simultaneous laryngeal and respiratory strategies.

    PubMed

    Stathopoulos, Elaine T; Huber, Jessica E; Richardson, Kelly; Kamphaus, Jennifer; DeCicco, Devan; Darling, Meghan; Fulcher, Katrina; Sussman, Joan E

    2014-01-01

    The objective of the present study was to investigate whether speakers with hypophonia, secondary to Parkinson's disease (PD), would increases their vocal intensity when speaking in a noisy environment (Lombard effect). The other objective was to examine the underlying laryngeal and respiratory strategies used to increase vocal intensity. Thirty-three participants with PD were included for study. Each participant was fitted with the SpeechVive™ device that played multi-talker babble noise into one ear during speech. Using acoustic, aerodynamic and respiratory kinematic techniques, the simultaneous laryngeal and respiratory mechanisms used to regulate vocal intensity were examined. Significant group results showed that most speakers with PD (26/33) were successful at increasing their vocal intensity when speaking in the condition of multi-talker babble noise. They were able to support their increased vocal intensity and subglottal pressure with combined strategies from both the laryngeal and respiratory mechanisms. Individual speaker analysis indicated that the particular laryngeal and respiratory interactions differed among speakers. The SpeechVive™ device elicited higher vocal intensities from patients with PD. Speakers used different combinations of laryngeal and respiratory physiologic mechanisms to increase vocal intensity, thus suggesting that disease process does not uniformly affect the speech subsystems. Readers will be able to: (1) identify speech characteristics of people with Parkinson's disease (PD), (2) identify typical respiratory strategies for increasing sound pressure level (SPL), (3) identify typical laryngeal strategies for increasing SPL, (4) define the Lombard effect. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Simple preparations of Pd6Cl12, Pt6Cl12, and Qn[Pt2Cl8+n], n=1, 2 (Q=TBA+, PPN+) and structural characterization of [TBA][Pt2Cl9] and [PPN]2[Pt2Cl10].C7H8.

    PubMed

    Dell'Amico, Daniela Belli; Calderazzo, Fausto; Marchetti, Fabio; Ramello, Stefano; Samaritani, Simona

    2008-02-04

    The hexanuclear Pd6Cl12, i.e., the crystal phase classified as beta-PdCl2, was obtained by reacting [TBA]2[Pd2Cl6] with AlCl3 (or FeCl3) in CH2Cl2. The action of AlCl3 on PtCl42-, followed by digestion of the resulting solid in 1,2-C2H4Cl2 (DCE), CHCl3, or benzene, produced Pt6Cl12.DCE, Pt6Cl12.CHCl3, or Pt6Cl12.C6H6, respectively. Treating [TBA]2[PtCl6] with a slight excess of AlCl3 afforded [TBA][Pt2Cl9], whose anion was established crystallographically to be constituted by two "PtCl6" octahedra sharing a face. Dehydration of H2PtCl6.nH2O with SOCl2 gave an amorphous compound closely analyzing as PtCl4, reactive with [Q]Cl in SOCl2 to yield [Q][Pt2Cl9] or [Q]2[Pt2Cl10], depending on the [Q]Cl/Pt molar ratio (Q=TBA+, PPN+). A single-crystal X-ray diffraction study has shown [PPN]2[Pt2Cl10].C7H8 to contain dinuclear anions formed by two edge-sharing PtCl6 octahedra.

  2. Magnesium and cadmium containing Heusler phases REPd2Mg, REPd2Cd, REAg2Mg, REAu2Mg and REAu2Cd

    NASA Astrophysics Data System (ADS)

    Johnscher, Michael; Stein, Sebastian; Niehaus, Oliver; Benndorf, Christopher; Heletta, Lukas; Kersting, Marcel; Höting, Christoph; Eckert, Hellmut; Pöttgen, Rainer

    2016-02-01

    Twenty-eight new Heusler phases REPd2Mg, REPd2Cd, REAg2Mg, REAu2Mg and REAu2Cd with different rare earth elements were synthesized from the elements in sealed niobium ampoules in a water-cooled sample chamber of an induction furnace. The samples were characterized by powder X-ray diffraction. The cell volumes show the expected lanthanide contraction. The structures of YPd2Cd, GdPd2Cd, GdAu2Cd, Y1.12Ag2Mg0.88 and GdAg2Mg were refined based on single crystal diffractometer data. The magnetic properties were determined for fifteen phase pure samples. LuAu2Mg is a weak Pauli paramagnet with a susceptibility of 1.0(2) × 10-5 emu mol-1 at room temperature. The remaining samples show stable trivalent rare earth ions and most of them order magnetically at low temperatures. The ferromagnet GdAg2Mg shows the highest ordering temperature of TC = 98.3 K. 113Cd and 89Y MAS NMR spectra of YAu2Cd and YPd2Cd confirm the presence of unique crystallographic sites. The resonances are characterized by large Knight shifts, whose magnitude can be correlated with electronegativity trends.

  3. Heterobimetallic complexes containing an N-heterocyclic carbene based multidentate ligand and catalyzed tandem click/Sonogashira reactions.

    PubMed

    Gu, Shaojin; Xu, Daichao; Chen, Wanzhi

    2011-02-21

    Mono- and polynuclear complexes containing 3-(1,10-phenanthrolin-2-yl)-1-(pyridin-2-ylmethyl)imidazolylidene (L), [NiL(2)](PF(6))(2) (2), [CoL(2)](PF(6))(3) (3), [PtLCl](PF(6)) (4), [PdAgL(2)](PF(6))(3) (5), [PdCuL(2)](PF(6))(3) (6), [Pd(2)L(2)Cl(2)](PF(6))(2) (7), and [Pd(3)L(2)Cl(4)](PF(6))(2) (8) have been prepared and fully characterized by NMR, ESI-MS spectroscopy, and X-ray crystallography. In complexes 2-4, the ligand binds to metals in a pincer NNC fashion with the pyridine group uncoordinated. Complexes 5 and 6 are isostructural to each other in which the palladium ions are surrounded by two pyridines and two imidazolylidenes and Ag(I) or Cu(I) is coordinated by two 1,10-phenanthroline moieties. In the trinuclear palladium complex 8, one palladium ion has an identical coordination mode as in 5 and 6, and the other two palladium ions are bonded to the 1,10-phenanthroline. Complex 6 exhibits excellent catalytic activity for the tandem click/Sonogashira reaction of 1-(bromomethyl)-4-iodobenzene, NaN(3), and ethynylbenzene in which three C-N bonds and one C-C bond are formed in a single flask.

  4. Energy Landscapes for the Self-Assembly of Supramolecular Polyhedra

    NASA Astrophysics Data System (ADS)

    Russell, Emily R.; Menon, Govind

    2016-06-01

    We develop a mathematical model for the energy landscape of polyhedral supramolecular cages recently synthesized by self-assembly (Sun et al. in Science 328:1144-1147, 2010). Our model includes two essential features of the experiment: (1) geometry of the organic ligands and metallic ions; and (2) combinatorics. The molecular geometry is used to introduce an energy that favors square-planar vertices (modeling {Pd}^{2+} ions) and bent edges with one of two preferred opening angles (modeling boomerang-shaped ligands of two types). The combinatorics of the model involve two-colorings of edges of polyhedra with four-valent vertices. The set of such two-colorings, quotiented by the octahedral symmetry group, has a natural graph structure and is called the combinatorial configuration space. The energy landscape of our model is the energy of each state in the combinatorial configuration space. The challenge in the computation of the energy landscape is a combinatorial explosion in the number of two-colorings of edges. We describe sampling methods based on the symmetries of the configurations and connectivity of the configuration graph. When the two preferred opening angles encompass the geometrically ideal angle, the energy landscape exhibits a very low-energy minimum for the most symmetric configuration at equal mixing of the two angles, even when the average opening angle does not match the ideal angle.

  5. Ammunition Cost Research Study. Volume I.

    DTIC Science & Technology

    1983-01-01

    0.048 4,000,000 1.72 1.74 M717 PD 0.25 571,490 8.22 6.13 M567 PD 1.30 300,000 10.43 17.22 M503A2 PD 0.34 814,701 10.64 7.28 M739 PD 1.43 915,837 10.65...M503A2 PD 0.34 252,336 10.73 7.58 M567 PD 1.30 1,071,100 11.23 16.29 M739 PD 1.43 915,837 11.30 17.47 M720 PD 2.10 90,000 11.41 23.46 m567 PD 1.30...14.86 12.91 M524A6 PD 1.27 3,982,150 15.11 13.04 M524A6 PD 1.27 3,181,102 15.44 13.81 M739 PD 1.43 3,168,072 15.47 14.86 M524A6 PD 1.27 3,045,000 17.37

  6. Microstructure, Phase Occurrence, and Corrosion Behavior of As-Solidified and As-Annealed Al-Pd Alloys

    NASA Astrophysics Data System (ADS)

    Ďuriška, Libor; Palcut, Marián; Špoták, Martin; Černičková, Ivona; Gondek, Ján; Priputen, Pavol; Čička, Roman; Janičkovič, Dušan; Janovec, Jozef

    2018-02-01

    In the present work, we studied the microstructure, phase constitution, and corrosion performance of Al88Pd12, Al77Pd23, Al72Pd28, and Al67Pd33 alloys (metal concentrations are given in at.%). The alloys were prepared by repeated arc melting of Al and Pd granules in argon atmosphere. The as-solidified samples were further annealed at 700 °C for 500 h. The microstructure and phase constitution of the as-solidified and as-annealed alloys were studied by scanning electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray diffraction. The alloys were found to consist of (Al), ɛ n ( Al3Pd), and δ (Al3Pd2) in various fractions. The corrosion testing of the alloys was performed in aqueous NaCl (0.6 M) using a standard 3-electrode cell monitored by potentiostat. The corrosion current densities and corrosion potentials were determined by Tafel extrapolation. The corrosion potentials of the alloys were found between - 763 and - 841 mV versus Ag/AgCl. An active alloy dissolution has been observed, and it has been found that (Al) was excavated, whereas Al in ɛ n was de-alloyed. The effects of bulk chemical composition, phase occurrence and microstructure on the corrosion behavior are evaluated. The local nobilities of ɛ n and δ are discussed. Finally, the conclusions about the alloy's corrosion resistance in saline solutions are provided.

  7. Fabrication and properties of multilayer structures

    NASA Astrophysics Data System (ADS)

    Tiller, W. A.

    1983-09-01

    The synthesis of SiC films and Pd2Si films via single source and dual source sputtering, respectively, has been experimentally investigated while the reactive sputter deposition of SiO sub x films has been theoretically analyzed. The SiO sub x film data requires a mobile precursor adsorption process to be operative for the oxygen and an oxygen sticking coefficient of between 1.56 x 10 to the minus 3rd power and 4.17 x 10 to the minus 3rd power. An analysis of in-situ electrical diagnostics of the films via a non-contact technique shows the method to be of marginal accuracy for the example selected. An important new formulation of the stress and elastic constant tensors in the vicinity of interfaces has been developed and applied to the simple example of adsorbed layer/substrate interactions via a parametric analysis. Atomic modeling of the SiO system yields peroxide bond formation for oxygen-rich (100) alpha-cristobalite surfaces. Radial distribution function and angular distribution function data have been calculated for bulk alpha-quartz and bulk alpha-cristobalite in good agreement with experiment.

  8. Complexes of platinum and palladium with β-diketones and DMSO: Synthesis, characterization, molecular modeling, and biological studies

    NASA Astrophysics Data System (ADS)

    do Couto Almeida, J.; Marzano, I. M.; de Paula, F. C. Silva; Pivatto, M.; Lopes, N. P.; de Souza, P. C.; Pavan, F. R.; Formiga, A. L. B.; Pereira-Maia, E. C.; Guerra, W.

    2014-10-01

    This work reports on the synthesis and characterization of new complexes of the type [MCl(L)DMSO], where L = 4,4,4-trifluoro-1-phenyl-1,3-butanedione (HTPB) or 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (HTTA) and M = Pt2+ or Pd2+. These complexes were characterized by elemental analyses, conductivity measurements, FT-IR, UV-Vis, high-resolution mass spectra (HRESIMS) and TG/DTA. In the complexes, the metallic ions bind to β-diketone via the oxygen atoms and to DMSO molecule via sulfur atom. The structures of complexes were optimized and theoretical data showed good agreement with the experimental results. The cytotoxic activity of the compounds was evaluated in a chronic myelogenous leukemia cell line. The platinum complexes were more cytotoxic than the free ligands and carboplatin and are promising candidates for further investigations. As example, the compound [PtCl(TPB)(DMSO)] inhibits the growth of K562 cells with an IC50 value equal to 2.5 μM. Furthermore, microbiological assays against Mycobacterium tuberculosis showed that all complexes exhibit low cytotoxicity against this bacterial strain while the free ligands exhibited MIC values of approximately 10 μg mL-1.

  9. Spectroscopic and electrochemical characterization of some Schiff base metal complexes containing benzoin moiety.

    PubMed

    El-Shahawi, M S; Al-Jahdali, M S; Bashammakh, A S; Al-Sibaai, A A; Nassef, H M

    2013-09-01

    The ligation behavior of bis-benzoin ethylenediamine (B2ED) and benzoin thiosemicarbazone (BTS) Schiff bases towards Ru(3+), Rh(3+), Pd(2+), Ni(2+) and Cu(2+) were determined. The bond length of M-N and spectrochemical parameters (10Dq, β, B and LFSE) of the complexes were evaluated. The redox characteristics of selected complexes were explored by cyclic voltammetry (CV) at Pt working electrode in non aqueous solvents. Au mesh (100 w/in.) optically transparent thin layer electrode (OTTLE) was also used for recording thin layer CV for selected Ru complex. Oxidation of some complexes occurs in a consecutive chemical reaction of an EC type mechanism. The characteristics of electron transfer process of the couples M(2+)/M(3+) and M(3+)/M(4+) (M=Ru(3+), Rh(3+)) and the stability of the complexes towards oxidation and/or reduction were assigned. The nature of the electroactive species and reduction mechanism of selected electrode couples were assigned. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Novel Phenotypic Outcomes Identified for a Public Collection of Approved Drugs from a Publicly Accessible Panel of Assays

    PubMed Central

    Oliver, Sarah; Willard, Francis S.; Heidler, Steven; Peery, Robert B.; Oler, Jennifer; Chu, Shaoyou; Southall, Noel; Dexheimer, Thomas S.; Smallwood, Jeffrey; Huang, Ruili; Guha, Rajarshi; Jadhav, Ajit; Cox, Karen; Austin, Christopher P.; Simeonov, Anton; Sittampalam, G. Sitta; Husain, Saba; Franklin, Natalie; Wild, David J.; Yang, Jeremy J.; Sutherland, Jeffrey J.; Thomas, Craig J.

    2015-01-01

    Phenotypic assays have a proven track record for generating leads that become first-in-class therapies. Whole cell assays that inform on a phenotype or mechanism also possess great potential in drug repositioning studies by illuminating new activities for the existing pharmacopeia. The National Center for Advancing Translational Sciences (NCATS) pharmaceutical collection (NPC) is the largest reported collection of approved small molecule therapeutics that is available for screening in a high-throughput setting. Via a wide-ranging collaborative effort, this library was analyzed in the Open Innovation Drug Discovery (OIDD) phenotypic assay modules publicly offered by Lilly. The results of these tests are publically available online at www.ncats.nih.gov/expertise/preclinical/pd2 and via the PubChem Database (https://pubchem.ncbi.nlm.nih.gov/) (AID 1117321). Phenotypic outcomes for numerous drugs were confirmed, including sulfonylureas as insulin secretagogues and the anti-angiogenesis actions of multikinase inhibitors sorafenib, axitinib and pazopanib. Several novel outcomes were also noted including the Wnt potentiating activities of rotenone and the antifolate class of drugs, and the anti-angiogenic activity of cetaben. PMID:26177200

  11. Suppression of ferromagnetic order by Ag-doping: A neutron scattering investigation on Ce2(Pd1-xAgx)2In (x = 0.20, 0.50).

    PubMed

    Martinelli, Alberto; Giovannini, Mauro; Sereni, Julian G; Ritter, Clemens

    2018-05-24

    The ground state magnetic behaviour of Ce2(Pd0.8Ag0.2)2In and Ce2(Pd0.5Ag0.5)2In, found in the ferromagnetic branch of Ce2Pd2In, has been investigated by neutron powder diffraction at low temperature. Ce2(Pd0.8Ag0.2)2In is characterized by a ferromagnetic structure with the Ce moments aligned along the c-axis and values of 0.96(2) μB. The compound retains the P4/mbm throughout the magnetic transition, although the magnetic ordering is accompanied by a significant decrease of the lattice strain along [00l], suggesting a magnetostructural contribution. The magnetic behaviour of Ce2(Pd0.5Ag0.5)2In is very different; this compound exhibits an extremely reduced magnetic scattering contribution in the diffraction pattern, that can be ascribed to a different kind of ferromagnetic ordering, with extremely reduced magnetic moments (~ 0.1 μB) aligned along [0l0]. These results point to a competition between different types of magnetic correlations induced by Ag-substitution, giving rise to a magnetically frustrated scenario in Ce2(Pd0.5Ag0.5)2In. © 2018 IOP Publishing Ltd.

  12. An approach to multivariable control of manipulators

    NASA Technical Reports Server (NTRS)

    Seraji, H.

    1987-01-01

    The paper presents simple schemes for multivariable control of multiple-joint robot manipulators in joint and Cartesian coordinates. The joint control scheme consists of two independent multivariable feedforward and feedback controllers. The feedforward controller is the minimal inverse of the linearized model of robot dynamics and contains only proportional-double-derivative (PD2) terms - implying feedforward from the desired position, velocity and acceleration. This controller ensures that the manipulator joint angles track any reference trajectories. The feedback controller is of proportional-integral-derivative (PID) type and is designed to achieve pole placement. This controller reduces any initial tracking error to zero as desired and also ensures that robust steady-state tracking of step-plus-exponential trajectories is achieved by the joint angles. Simple and explicit expressions of computation of the feedforward and feedback gains are obtained based on the linearized model of robot dynamics. This leads to computationally efficient schemes for either on-line gain computation or off-line gain scheduling to account for variations in the linearized robot model due to changes in the operating point. The joint control scheme is extended to direct control of the end-effector motion in Cartesian space. Simulation results are given for illustration.

  13. X-Ray Photoelectron Spectroscopy Study of the Heating Effects on Pd/6H-SiC Schottky Structure

    NASA Technical Reports Server (NTRS)

    Chen, Liang-Yu; Hunter, Gary W.; Neudeck, Philip G.; Knight, Dak

    1998-01-01

    X-ray photoelectron spectroscopy is used to study the effects of heat treatment on the Pd/6H-SiC Schottky diode structure. After heating the structure at 425 C for 140 h, a very thin surface layer of PdO mixed with SiO(x) formed on the palladium surface of the Schottky structure. Heat treatment promoted interfacial diffusion and reaction which significantly broadened the interfacial region. In the interfacial region, the palladium concentration decreases with depth, and the interfacial products are Pd(x)Si (x = 1,2,3,4). In the high Pd concentration regions, Pd4Si is the major silicide component while gr and Pd2Si are major components in the low Pd concentration region. At the center of the interface, where the total palladium concentration equals that of silicon, the concentrations of palladium associated with various palladium silicides (Pd(x)Si, x= 1,2,3,4) are approximately equal. The surface passivation layer composed of PdO and SiO, may significantly affect the electronic and catalytic properties of the surface of the Schottky diode which plays a major role in gas detection. The electronic properties of the Schottky structure may be dominated by a (Pd+Pd(x)Si)/SiC interface. In order to stabilize the properties of the Schottky structure the surface and interface diffusion and reactions must be controlled.

  14. Synthesis of monodentate ferrocenylphosphines and their application to the palladium-catalyzed Suzuki reaction of aryl chlorides.

    PubMed

    Pickett, Tom E; Roca, Francesc X; Richards, Christopher J

    2003-04-04

    Racemic and enantiopure ((p)()S)-1-bromo-2-methylferrocene 6 were synthesized in 4 steps from 2-(4,4-dimethyloxazolinyl)ferrocene and (S)-2-(4-methylethyloxazolinyl)ferrocene, respectively (46 and 81% overall yield). Bromolithium exchange and addition of ClPR(2) gave the corresponding racemic or enantiopure 2-methylferrocenyl phosphine ligands 2-MeFcPR(2) 11 (R = Ph), 12 (R = Cy), and 13 (R = (t)Bu) in 28-93% yield. Use of PCl(3) gave the C(3)-symmetric phosphine (2-MeFc)(3)P 5 from ((p)()S)-6(72% yield) but racemic 6 did not lead to the formation of triferrocenyl phosphines. Combination of 5 and Pd(2)(dba)(3) gave an active catalyst for the Suzuki reaction of aryl chlorides, for example, 4-chlorotoluene and phenylboronic acid reacted at only 60 degrees C in dioxane (86% yield). Other examples are reported together with the use of 12 in this same protocol. From the X-ray crystal structure of 5 the cone angle was determined as 211 degrees. With this, and the electronic character of 11, 12, and other phosphines (derived from nu(CO) of trans-[(R(3)P)(2)Rh(CO)Cl]), an analysis is made of the steric and electronic influences on ligand activity in the Suzuki reaction.

  15. Electro-oxidation of methanol in alkaline conditions using Pd-Ni nanoparticles prepared from organometallic precursors and supported on carbon vulcan

    NASA Astrophysics Data System (ADS)

    Manzo-Robledo, A.; Costa, Natália J. S.; Philippot, K.; Rossi, Liane M.; Ramírez-Meneses, E.; Guerrero-Ortega, L. P. A.; Ezquerra-Quiroga, S.

    2015-12-01

    Oxidation of low-molecular weight alcohols as energy sources using metal nanoparticles has attracted considerable interest for use as a power source in portable electronic devices. In this work, a series of mono- and bimetallic nanoparticles based on palladium and nickel (Pd, Pd90Ni10, Pd50Ni50, Pd10Ni90, and Ni) have been synthesized from organometallic precursors, namely tris(dibenzylideneacetone) dipalladium(0), Pd2(dba)3, and bis(1,5-cyclooctadiene)nickel(0), Ni(cod)2. Well-defined metal particles in the nanometric scale from 4.2 to 6.3 nm were observed by transmission electron microscopy. The as-prepared nanoparticles were mixed with a carbon Vulcan matrix (10 % wt. of the catalyst in turn) for investigation as electrocatalysts in methanol oxidation reaction (MOR) in alkaline conditions. The i- E profiles from cyclic voltammetry for the monometallic systems indicated a redox process attributed only to palladium or nickel, as expected. With the bimetallic nanomaterials, the redox process and the i- E characteristics are functions of the amount of nickel associated to palladium. From a fundamental point of view, it has been established that the OH ions' interfacial interaction and the MOR kinetics are affected by the presence of nickel (decreasing the faradic current) as supported by the current versus potential profiles obtained as a function of methanol concentration and with temperature variation.

  16. Novel Phenotypic Outcomes Identified for a Public Collection of Approved Drugs from a Publicly Accessible Panel of Assays.

    PubMed

    Lee, Jonathan A; Shinn, Paul; Jaken, Susan; Oliver, Sarah; Willard, Francis S; Heidler, Steven; Peery, Robert B; Oler, Jennifer; Chu, Shaoyou; Southall, Noel; Dexheimer, Thomas S; Smallwood, Jeffrey; Huang, Ruili; Guha, Rajarshi; Jadhav, Ajit; Cox, Karen; Austin, Christopher P; Simeonov, Anton; Sittampalam, G Sitta; Husain, Saba; Franklin, Natalie; Wild, David J; Yang, Jeremy J; Sutherland, Jeffrey J; Thomas, Craig J

    2015-01-01

    Phenotypic assays have a proven track record for generating leads that become first-in-class therapies. Whole cell assays that inform on a phenotype or mechanism also possess great potential in drug repositioning studies by illuminating new activities for the existing pharmacopeia. The National Center for Advancing Translational Sciences (NCATS) pharmaceutical collection (NPC) is the largest reported collection of approved small molecule therapeutics that is available for screening in a high-throughput setting. Via a wide-ranging collaborative effort, this library was analyzed in the Open Innovation Drug Discovery (OIDD) phenotypic assay modules publicly offered by Lilly. The results of these tests are publically available online at www.ncats.nih.gov/expertise/preclinical/pd2 and via the PubChem Database (https://pubchem.ncbi.nlm.nih.gov/) (AID 1117321). Phenotypic outcomes for numerous drugs were confirmed, including sulfonylureas as insulin secretagogues and the anti-angiogenesis actions of multikinase inhibitors sorafenib, axitinib and pazopanib. Several novel outcomes were also noted including the Wnt potentiating activities of rotenone and the antifolate class of drugs, and the anti-angiogenic activity of cetaben.

  17. Shifting Plasma

    NASA Image and Video Library

    2017-12-08

    Strands of solar material at the sun's edge shifted and twisted back and forth over a 22-hour period in this footage captured May 2-3, 2017, by NASA’s Solar Dynamics Observatory. In this close-up, the strands are being manipulated by strong magnetic forces associated with active regions. To give a sense of scale, the strands that hover above the sun are more than several times the size of Earth. These images were taken in a wavelength of extreme ultraviolet light, which is typically invisible to our eyes, but was colorized here in red. go.nasa.gov/2qJzPD2 Credit: NASA/Goddard/SDO NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  18. Metallization of Kevlar fibers with gold.

    PubMed

    Little, Brian K; Li, Yunfeng; Cammarata, V; Broughton, R; Mills, G

    2011-06-01

    Electrochemical gold plating processes were examined for the metallization of Kevlar yarn. Conventional Sn(2+)/Pd(2+) surface activation coupled with electroless Ni deposition rendered the fibers conductive enough to serve as cathodes for electrochemical plating. The resulting coatings were quantified gravimetrically and characterized via adhesion tests together with XRD, SEM, TEM; the coatings effect on fiber strength was also probed. XRD data showed that metallic Pd formed during surface activation whereas amorphous phases and trace amounts of pure Ni metal were plated via the electroless process. Electrodeposition in a thiosulfate bath was the most efficient Au coating process as compared with the analogous electroless procedure, and with electroplating using a commercial cyanide method. Strongly adhering coatings resulted upon metallization with three consecutive electrodepositions, which produced conductive fibers able to sustain power outputs in the range of 1 W. On the other hand, metallization affected the tensile strength of the fiber and defects present in the metal deposits make questionable the effectiveness of the coatings as protective barriers. © 2011 American Chemical Society

  19. Electronic structures and superconductivity in LuTE2Si2 phases (TE = d-electron transition metal)

    NASA Astrophysics Data System (ADS)

    Samsel-Czekała, M.; Chajewski, G.; Wiśniewski, P.; Romanova, T.; Hackemer, A.; Gorzelniak, R.; Pikul, A. P.; Kaczorowski, D.

    2018-05-01

    In the course of our search for unconventional superconductors amidst the 1:2:2 phases, we have re-investigated the LuTE2Si2 compounds with TE = Fe, Co, Ni, Ru, Pd and Pt. In this paper, we present the results of our fully relativistic ab initio calculations of the band structures, performed using the full-potential local-orbital code. The theoretical data are supplemented by the results of low-temperature electrical transport and specific heat measurements performed down to 0.35 K. All the materials studied but LuPt2Si2 crystallize with the body-centered tetragonal ThCr2Si2-type structure (space group I4/mmm). Their Fermi surfaces exhibit a three-dimensional multi-band character. In turn, the Pt-bearing compound adopts the primitive tetragonal CaBe2Ge2-type structure (space group P4/nmm), and its Fermi surface consists of predominantly quasi-two-dimensional sheets. Bulk superconductivity was found only in LuPd2Si2 and LuPt2Si2 (independent of the structure type and dimensionality of the Fermi surface). The key superconducting characteristics indicate a fully-gapped BCS type character. Though the electronic structure of LuFe2Si2 closely resembles that of the unconventional superconductor YFe2Ge2, this Lu-based silicide exhibits neither superconductivity nor spin fluctuations at least down to 0.35 K.

  20. Effects of stress on heart rate complexity--a comparison between short-term and chronic stress.

    PubMed

    Schubert, C; Lambertz, M; Nelesen, R A; Bardwell, W; Choi, J-B; Dimsdale, J E

    2009-03-01

    This study examined chronic and short-term stress effects on heart rate variability (HRV), comparing time, frequency and phase domain (complexity) measures in 50 healthy adults. The hassles frequency subscale of the combined hassles and uplifts scale (CHUS) was used to measure chronic stress. Short-term stressor reactivity was assessed with a speech task. HRV measures were determined via surface electrocardiogram (ECG). Because respiration rate decreased during the speech task (p<.001), this study assessed the influence of respiration rate changes on the effects of interest. A series of repeated-measures analyses of covariance (ANCOVA) with Bonferroni adjustment revealed that short-term stress decreased HR D2 (calculated via the pointwise correlation dimension PD2) (p<.001), but increased HR mean (p<.001), standard deviation of R-R (SDRR) intervals (p<.001), low (LF) (p<.001) and high frequency band power (HF) (p=.009). Respiratory sinus arrhythmia (RSA) and LF/HF ratio did not change under short-term stress. Partial correlation adjusting for respiration rate showed that HR D2 was associated with chronic stress (r=-.35, p=.019). Differential effects of chronic and short-term stress were observed on several HRV measures. HR D2 decreased under both stress conditions reflecting lowered functionality of the cardiac pacemaker. The results confirm the importance of complexity metrics in modern stress research on HRV.

  1. Synthesis, biological evaluation and molecular modeling of 1-oxa-4-thiaspiro- and 1,4-dithiaspiro[4.5]decane derivatives as potent and selective 5-HT1A receptor agonists.

    PubMed

    Franchini, Silvia; Manasieva, Leda Ivanova; Sorbi, Claudia; Battisti, Umberto M; Fossa, Paola; Cichero, Elena; Denora, Nunzio; Iacobazzi, Rosa Maria; Cilia, Antonio; Pirona, Lorenza; Ronsisvalle, Simone; Aricò, Giuseppina; Brasili, Livio

    2017-01-05

    Recently, 1-(1,4-dioxaspiro[4,5]dec-2-ylmethyl)-4-(2-methoxyphenyl)piperazine (1) was reported as a potent 5-HT 1A R agonist with a moderate 5-HT 1A R selectivity. In an extension of this work a series of derivatives of 1, obtained by combining different heterocyclic rings with a more flexible amine chain, was synthesized and tested for binding affinity and activity at 5-HT 1A R and α 1 adrenoceptors. The results led to the identification of 14 and 15 as novel 5-HT 1A R partial agonists, the first being outstanding for selectivity (5-HT 1A /α 1d  = 80), the latter for potency (pD 2  = 9.58) and efficacy (E max  = 74%). Theoretical studies of ADME properties shows a good profile for the entire series and MDCKII-MDR1 cells permeability data predict a good BBB permeability of compound 15, which possess a promising neuroprotective activity. Furthermore, in mouse formalin test, compound 15 shows a potent antinociceptive activity suggesting a new strategy for pain control. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  2. Carbon-supported PdM (M = Au and Sn) nanocatalysts for the electrooxidation of ethanol in high pH media

    NASA Astrophysics Data System (ADS)

    He, Qinggang; Chen, Wei; Mukerjee, Sanjeev; Chen, Shaowei; Laufek, František

    Carbon-supported Pd 4Au- and Pd 2.5Sn-alloyed nanoparticles were prepared by a chemical reduction method, and characterized by a wide array of experimental techniques including mass spectrometry, transmission electron microscopy, and X-ray diffraction spectroscopy. Ethanol electrooxidation on the as-synthesized catalysts and commercial Pt/C was then investigated and compared in alkaline media by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy studies at room temperature. Voltammetric and chronoamperometric measurements showed higher current density and longer term stability in ethanol oxidation with the palladium alloy nanocatalysts than with the commercial one. Electrochemical impedance spectroscopy and Tafel plots were employed to examine the charge-transfer kinetics of ethanol electrooxidation. The results suggest that whereas the reaction kinetics might be somewhat more sluggish on the Pd-based alloy catalysts than on commercial Pt/C, the former appeared to have a higher tolerance to surface poisoning. Overall, the Pd-based alloy catalysts represent promising candidates for the electrocatalytic oxidation of ethanol, and Pd 4Au/C displays the best catalytic activity among the series for the ethanol oxidation in alkaline media.

  3. Selective hydrogenation of phenol to cyclohexanone over Pd@CN (N-doped porous carbon): Role of catalyst reduction method

    NASA Astrophysics Data System (ADS)

    Hu, Shuo; Yang, Guangxin; Jiang, Hong; Liu, Yefei; Chen, Rizhi

    2018-03-01

    Selective phenol hydrogenation is a green and sustainable technology to produce cyclohexanone. The work focused on investigating the role of catalyst reduction method in the liquid-phase phenol hydrogenation to cyclohexanone over Pd@CN (N-doped porous carbon). A series of reduction methods including flowing hydrogen reduction, in-situ reaction reduction and liquid-phase reduction were designed and performed. The results highlighted that the reduction method significantly affected the catalytic performance of Pd@CN in the liquid-phase hydrogenation of phenol to cyclohexanone, and the liquid-phase reduction with the addition of appropriate amount of phenol was highly efficient to improve the catalytic activity of Pd@CN. The influence mechanism was explored by a series of characterizations. The results of TEM, XPS and CO chemisorption confirmed that the reduction method mainly affected the size, surface composition and dispersion of Pd in the CN material. The addition of phenol during the liquid-phase reduction could inhibit the aggregation of Pd NPs and promote the reduction of Pd (2+), and then improved the catalytic activity of Pd@CN. The work would aid the development of high-performance Pd@CN catalysts for selective phenol hydrogenation.

  4. Mesomorphic properties of multi-arm chenodeoxycholic acid-derived liquid crystals

    NASA Astrophysics Data System (ADS)

    Dong, Liang; Yao, Miao; Wu, Shuang-jie; Yao, Dan-Shu; Hu, Jian-She; He, Xiao-zhi; Tian, Mei

    2017-12-01

    Four multi-arm liquid crystals (LCs) based on chenodeoxycholic acid, termed as 2G-PD, 2G-IB, 2G-BD and 5G-GC, respectively, have been synthesised by convergent method, which nematic LC, 6-(4-((4-ethoxybenzoyl)oxy)phenoxy)-6-oxohexanoic acid, was used as side arm, and chenodeoxycholic acid (CDCA) was used as the first core, 1,2-propanediol (PD), isosorbide (IB), 4,4‧-biphenyldiol (BD) and glucose (GC) were used as the second core, respectively. The first generation product, CDCA2EA, displayed cholesteric phase. The second generation products 2G-BD and 5G-GC displayed cholesteric phase, while 2G-PD and 2G-IB exhibited nematic phase. The multi-arm LC, 2G-IB, did not display cholesteric phase although the two cores were all chiral ones. The result indicated that chirality of the second core sometimes made the multi-arm LCs display nematic phase when cholesteric CDCA-derivative were introduced into the second core. Some attention should be paid on molecular conformation besides the introduction of chiral cores for multi-chiral-core LCs to obtain cholesteric phase.

  5. Alternate electrode materials for the SP100 reactor

    NASA Astrophysics Data System (ADS)

    Randich, E.

    1992-05-01

    This work was performed in response to a request by the Astro-Space Division of the General Electric Co. to develop alternate electrodes materials for the electrodes of the PD2 modules to be used in the SP100 thermoelectric power conversion system. Initially, the project consisted of four tasks: (1) development of a ZrB2 (C) CVD coating on SiMo substrates; (2) development of a ZrB2 (C) CVD coating on SiGe substrates; (3) development of CVI W for porous graphite electrodes; and (4) technology transfer of pertinent developed processes. The project evolved initially into developing only ZrB2 coatings on SiGe and graphite substrates, and later into developing ZrB2 coatings only on graphite substrates. Several sizes of graphite and pyrolytic carbon-coated graphite substrates were coated with ZrB2 during the project. For budgetary reasons, the project was terminated after half the allotted time had passed. Apart from the production of coated specimens for evaluation, the major accomplishment of the project was the development of the CVD processing to produce the desired coatings.

  6. Redetermination of (2,2'-bipyridine-κN,N')dichlorido-palladium(II) dichloro-methane solvate.

    PubMed

    Kim, Nam-Ho; Hwang, In-Chul; Ha, Kwang

    2009-05-07

    In the title compound, [PdCl(2)(C(10)H(8)N(2))]·CH(2)Cl(2), the Pd(2+) ion is four-coordinated in a slightly distorted square-planar environment by two N atoms of the 2,2'-bipyridine (bipy) ligand and two chloride ions. The compound displays intra-molecular C-H⋯Cl hydrogen bonds and pairs of complex mol-ecules are connected by inter-molecular C-H⋯Cl hydrogen bonds. Inter-molecular π-π inter-actions are present between the pyridine rings of the ligand, the shortest centroid-centroid distance being 4.096 (3) Å. As a result of the electronic nature of the chelate ring, it is possible to create π-π inter-actions to its symmetry-related counterpart [3.720 (2) Å] and also with a pyridine ring [3.570 (3) Å] of the bipy unit. The present structure is a redetermination of a previous structure [Vicente et al. (1997 ▶). Private communication (refcode PYCXMN02). CCDC, Cambridge, England]. In the new structure refinement all H atoms were located in a difference Fourier synthesis. Their coordinates were refined freely, together with isotropic displacement parameters.

  7. Paleogeographic implications of Late Miocene lacustrine and nonmarine evaporite deposits in the Lake Mead region: Immediate precursors to the Colorado River

    USGS Publications Warehouse

    Faulds, James E.; Schreiber, Charlotte; Langenheim, Victoria; Hinz, Nicholas H.; Shaw, Tom; Heizler, Matthew T.; Perkins, Michael E; El Tabakh, Mohammed; Kunk, Michael J.

    2016-01-01

    Thick late Miocene nonmarine evaporite (mainly halite and gypsum) and related lacustrine limestone deposits compose the upper basin fill in half grabens within the Lake Mead region of the Basin and Range Province directly west of the Colorado Plateau in southern Nevada and northwestern Arizona. Regional relations and geochronologic data indicate that these deposits are late synextensional to postextensional (ca. 12–5 Ma), with major extension bracketed between ca. 16 and 9 Ma and the abrupt western margin of the Colorado Plateau established by ca. 9 Ma. Significant accommodation space in the half grabens allowed for deposition of late Miocene lacustrine and evaporite sediments. Concurrently, waning extension promoted integration of initially isolated basins, progressive enlargement of drainage nets, and development of broad, low gradient plains and shallow water bodies with extensive clastic, carbonate, and/or evaporite sedimentation. The continued subsidence of basins under restricted conditions also allowed for the preservation of particularly thick, localized evaporite sequences prior to development of the through-going Colorado River.The spatial and temporal patterns of deposition indicate increasing amounts of freshwater input during the late Miocene (ca. 12–6 Ma) immediately preceding arrival of the Colorado River between ca. 5.6 and 4.9 Ma. In axial basins along and proximal to the present course of the Colorado River, evaporite deposition (mainly gypsum) transitioned to lacustrine limestone progressively from east to west, beginning ca. 12–11 Ma in the Grand Wash Trough in the east and shortly after ca. 5.6 Ma in the western Lake Mead region. In several satellite basins to both the north and south of the axial basins, evaporite deposition was more extensive, with thick halite (>200 m to 2.5 km thick) accumulating in the Hualapai, Overton Arm, and northern Detrital basins. Gravity and magnetic lows suggest that thick halite may also lie within the

  8. Phytotoxkit® and Ostracodtoxkit® tests for assessing the toxicity of sediment samples with high concentration of heavy metals

    NASA Astrophysics Data System (ADS)

    Garcia-Lorenzo, Maria Luz; Martinez-Sanchez, Maria Jose; Molina, Jose; Hernandez-Cordoba, Manuel

    2010-05-01

    To estimate the risk of contaminants, chemical methods need to be complemented with biological methods. Ecotoxicological testing may be a useful approach for assessing the toxicity as a complement to chemical analysis. The aim of this study was to evaluate the sensitivity and applicability of two bioassays representing multiple trophic levels, for the preliminary ecotoxicological screening of sediments from sites contaminated by mining activities: a chronic toxicity test with the ostracod Heterocypris incongruens and a phytotoxicity test using Lepidium sativum, Sorghum saccharatum and Sinapis alba seeds. For this study, 30 soils samples were collected from the Sierra Minera (Murcia, SE Spain) for general analytical determinations and the total metal content (Pb, Zn, Cd and As) was determined. The Phytotoxkit® test measures the decrease in (or the absence of) seed germination and of the growth of the young roots after 3 days of exposure of seeds of selected higher plants to a contaminated matrix compared with the controls germinated in a reference soil. The plants selected for the Phytotoxkit® microbiotest were: the monocotyl Sorghum saccharatum (Sorgho) and the dicotyls Lepidium sativum (Garden cress) and Sinapis alba (mustard) (Phytotoxkit®, 2004). The percent inhibition of seed germination (SG) and root growth inhibition (RI) for each plant were calculated. Ostracodtoxkit® test consists of placing freshly hatched ostracod neonates in multiwell cups in 2 ml synthetic freshwater, with 300 µl sediment and 3x107 algal cells (Selenastrum capricornutum). After 6 days, incubation at 25 °C in darkness, the mortality of test organisms was determined (Ostracodtoxkit® FTM, 2001) and growth inhibition was calculated. Soil samples showed a mean pH value of 6.0 in water and 5.7 in KCl. The EC varied from 1.0 dS m-1 to 56.2 dS m-1, with a mean value of 17.7 dS m-1. The mean value for Pb was 0.84 mg kg-1, 10593 mg kg-1 for Zn, 23.18 mg kg-1 for Cd and 0.16 mg kg-1 for As

  9. Pulmonary microsomes contain a Ca(2+)-transport system sensitive to oxidative stress.

    PubMed

    Menshikova, E V; Ritov, V B; Shvedova, A A; Elsayed, N; Karol, M H; Kagan, V E

    1995-03-14

    A variety of events, including inhalation of atmospheric chemicals, trauma, and ischemia-reperfusion, may cause generation of reactive oxygen species in the lung and result in airways constriction. The specific metabolic mechanisms that translate oxygen radical production into airways constriction are yet to be identified. In the lung, calcium homeostasis is central to release of bronchoactive and vasoactive chemical mediators and to regulation of smooth muscle cell contractility, i.e., airway constriction. In the present work, we characterized Ca(2+)-transport in the microsomal fraction of mouse lungs, and determined how reactive oxygen species, generated by Fe2+/ascorbate and H2O2/hemoglobin, affected Ca2+ transport. The microsomal fraction of pulmonary tissue accumulated 90 +/- 5 nmol Ca2+/mg protein by an ATP-dependent process in the presence of 15 mM oxalate, and 16 +/- 2 nmol Ca2+ in its absence. In the presence of oxalate, the rate of Ca2+ uptake was 50 +/- 5 nmol Ca2+/min per mg protein at pCa 5.9 (37 degrees C). The Ca(2+)-ATPase activity was 50-60 nmol Pi/min per mg protein (pCa 5.9, 37 degrees C) in the presence of alamethicin. Inhibitors of mitochondrial H(+)-ATPase had no effect on the Ca2+ transport. Half-maximal activation of Ca2+ transport was produced by 0.4-0.5 microM Ca2+. Endoplasmic reticulum Ca(2+)-pump (SERC-ATPase) was found to be predominantly responsible for the Ca(2+)-accumulating capacity of the pulmonary microsomes. Incubation of the microsomes in the presence of either Fe2+/ascorbate or H2O2/hemoglobin resulted in a time-dependent accumulation of peroxidation products (TBARS) and in inhibition of the Ca2+ transport. The inhibitory effect of Fe2+/ascorbate on Ca2+ transport strictly correlated with the inhibition of the Ca(2+)-ATPase activity. These results are the first to indicate a highly active microsomal Ca2+ transport system in murine lungs which is sensitive to endogenous oxidation products. The importance of this system to

  10. Chironomid record of Late Quaternary climatic and environmental changes from two sites in Central Asia (Tuva Republic, Russia)—local, regional or global causes?

    NASA Astrophysics Data System (ADS)

    Ilyashuk, Boris P.; Ilyashuk, Elena A.

    2007-03-01

    Sediment cores from two mountain lakes (Lake Grusha at 2413 m a.s.l. and Ak-Khol at 2204 m a.s.l.) situated in the Tuva Republic (southern Siberia, Russia), just north of Mongolia, were studied for chironomid fossils in order to infer post-glacial climatic changes and to investigate responses of the lake ecosystems to these changes. The results show that chironomids are responding both to temperature and to changing lake depth, which is regarded as a sensitive proxy of regional effective moisture. The post-glacial history of this mountain region in Central Asia can be divided into seven successive climatic phases: the progressive warming during the last glacial-interglacial transition (ca 15.8-14.6 cal kyr BP), the warm and moist Bølling-Allerød-like interval (ca 14.6-13.1 cal kyr BP), the cool and dry Younger Dryas-like event (ca 13.1-12.1 cal kyr BP), warmer and wetter conditions during ca 12.1-8.5 cal kyr BP, a warm and dry phase ca 8.5-5.9 cal kyr BP, cold and wet conditions during ca 5.9-1.8 cal kyr BP, as well as cold and dry climate within the last 1800 years. The chironomid records reveal patterns of climatic variability during the Late-glacial and Holocene, which can be correlated with abrupt climatic events in the North Atlantic and the Asian monsoon-dominated regimes. Apparently, the water balance of the studied lakes is controlled by the interrelation between the dominant westerly system and the changing influence of the summer monsoon, as well as the influence of alpine glacier meltwater supply. It is possible that monsoon tracks could have reached the southwest Tuva, resulting in an increase in precipitation at ca 14.6-13.1 and ca 12.1-8.5 cal kyr BP, whereas cyclonic westerlies from the North Atlantic were likely responsible for considerable moisture transport accompanying the global Neoglacial cooling at ca 5.9-1.8 cal kyr BP. These events suggest the changes of the regional pattern of atmospheric circulation, which could be in turn induced by the

  11. Validation of cooking times and temperatures for thermal inactivation of Yersinia pestis strains KIM5 and CDC-A1122 in irradiated ground beef.

    PubMed

    Porto-Fett, Anna C S; Juneja, Vijay K; Tamplin, Mark L; Luchansky, John B

    2009-03-01

    Irradiated ground beef samples (ca. 3-g portions with ca. 25% fat) inoculated with Yersina pestis strain KIM5 (ca. 6.7 log CFU/g) were heated in a circulating water bath stabilized at 48.9, 50, 52.5, 55, 57.5, or 60 degrees C (120, 122, 126.5, 131, 135.5, and 140 degrees F, respectively). Average D-values were 192.17, 34.38, 17.11, 3.87, 1.32, and 0.56 min, respectively, with a corresponding z-value of 4.67 degrees C (8.41 degrees F). In related experiments, irradiated ground beef patties (ca. 95 g per patty with ca. 25% fat) were inoculated with Y. pestis strains KIMS or CDC-A1122 (ca. 6.0 log CFU/g) and cooked on an open-flame gas grill or on a clam-shell type electric grill to internal target temperatures of 48.9, 60, and 71.1 degrees C (120, 140, and 160 degrees F, respectively). For patties cooked on the gas grill, strain KIM5 populations decreased from ca. 6.24 to 4.32, 3.51, and < or = 0.7 log CFU/g at 48.9, 60, and 71.1 degrees C, respectively, and strain CDC-A1122 populations decreased to 3.46 log CFU/g at 48.9 degrees C and to < or = 0.7 log CFU/g at both 60 and 71.1 degrees C. For patties cooked on the clam-shell grill, strain KIM5 populations decreased from ca. 5.96 to 2.53 log CFU/g at 48.9 degrees C and to < or = 0.7 log CFU/g at 60 or 71.1 degrees C, and strain CDC-A1122 populations decreased from ca. 5.98 to < or = 0.7 log CFU/g at all three cooking temperatures. These data confirm that cooking ground beef on an open-flame gas grill or on a clam-shell type electric grill to the temperatures and times recommended by the U.S. Department of Agriculture and the U.S. Food and Drug Administration Food Code, appreciably lessens the likelihood, severity, and/or magnitude of consumer illness if the ground beef were purposefully contaminated even with relatively high levels of Y. pestis.

  12. Removal of phosphorus, fluoride and metals from a gypsum mining leachate using steel slag filters.

    PubMed

    Claveau-Mallet, Dominique; Wallace, Scott; Comeau, Yves

    2013-03-15

    The objective of this work was to evaluate the capacity of steel slag filters to treat a gypsum mining leachate containing 11-107 mg P/L ortho-phosphates, 9-37 mg/L fluoride, 0.24-0.83 mg/L manganese, 0.20-3.3 zinc and 1.7-8.2 mg/L aluminum. Column tests fed with reconstituted leachates were conducted for 145-222 days and sampled twice a week. Two types of electric arc furnace (EAF) slags and three filter sequences were tested. The voids hydraulic retention time (HRT(v)) of columns ranged between 4.3 and 19.2 h. Precipitates of contaminants present in columns were sampled and analyzed with X-ray diffraction at the end of tests. The best removal efficiencies over a period of 179 days were obtained with sequential filters that were composed of Fort Smith EAF slag operated at a total HRT(v) of 34 h which removed 99.9% of phosphorus, 85.3% of fluoride, 98.0% of manganese and 99.3% of zinc. Mean concentration at this system's effluent was 0.04 mg P/L ortho-phosphates, 4 mg/L fluoride, 0.02 mg/L manganese, 0.02 zinc and 0.5 mg/L aluminum. Thus, slag filters are promising passive and economical systems for the remediation of mining effluents. Phosphorus was removed by the formation of apatite (hydroxyapatite, Ca(5)(PO(4))(3)OH or fluoroapatite, Ca(5)(PO(4))(3)F) as confirmed by visual and X-ray diffraction analyses. The growth rate of apatite was favored by a high phosphorus concentration. Calcite crystals were present in columns and appeared to be competing for calcium and volume needed for apatite formation. The calcite crystal growth rate was higher than that of apatite crystals. Fluoride was removed by precipitation of fluoroapatite and its removal was favored by a high ratio of phosphorus to fluoride in the wastewater. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Biogenic hydroxyapatite (Apatite II™) dissolution kinetics and metal removal from acid mine drainage.

    PubMed

    Oliva, J; Cama, J; Cortina, J L; Ayora, C; De Pablo, J

    2012-04-30

    Apatite II™ is a biogenic hydroxyapatite (expressed as Ca(5)(PO(4))OH) derived from fish bone. Using grains of Apatite II™ with a fraction size between 250 and 500 μm, batch and flow-through experiments were carried out to (1) determine the solubility constant for the dissolution reaction Ca(5)(PO(4))(3)(OH) ⇔ 5Ca(2+) + 3PO(4)(3-) + OH(-), (2) obtain steady-state dissolution rates over the pH range between 2.22 and 7.14, and (3) study the Apatite II™'s mechanisms to remove Pb(2+), Zn(2+), Mn(2+), and Cu(2+) from metal polluted water as it dissolves. The logK(S) value obtained was -50.8±0.82 at 25 °C. Far-from-equilibrium fish-bone hydroxyapatite dissolution rates decrease by increasing pH. Assuming that the dissolution reaction is controlled by fast adsorption of a proton on a specific surface site that dominates through the pH range studied, probably ≡PO(-), followed by a slow hydrolysis step, the dissolution rate dependence is expressed in mol m(-2) s(-1) as where Rate(25 °C) = -8.9 × 10(-10) × [9.96 × 10(5) × a(H+)]/[1 + 9.96 × 10(5) × a(H+)] where a(H+) is the proton activity in solution. Removal of Pb(2+), Zn(2+), Mn(2+) and Cu(2+) was by formation of phosphate-metal compounds on the Apatite II™ substrate, whereas removal of Cd(2+) was by surface adsorption. Increase in pH enhanced the removal of aqueous heavy metals. Using the kinetic parameters obtained (e.g., dissolution rate and pH-rate dependence law), reactive transport simulations reproduced the experimental variation of pH and concentrations of Ca, P and toxic divalent metal in a column experiment filled with Apatite II™ that was designed to simulate the Apatite II™-metal polluted water interaction. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Synthesis and application of hydroxyapatite and fluoroapatite to scorodite encapsulation

    NASA Astrophysics Data System (ADS)

    Katsarou, Lydia

    Recent research has investigated the precipitation of crystalline scorodite (FeAsO4˙2H2O) as a method to stabilise arsenic for disposal due to its good stability performance according to EPA's TCLP test. It has been determined, however, that scorodite releases arsenic in significant concentrations under alkaline pH or under anoxic conditions. With the objective of enhancing the stability of scorodite, its encapsulation with minerals inert to pH and redox potential variations is considered in this work. Such encapsulation materials are hydroxyapatite (HAP-Ca5(PO4)3OH) and fluoroapatite (FAP-Ca5(PO4)3F), the two most stable of the calcium phosphates. The work described in this thesis includes: 1) the preparation of hydroxyapatite and fluoroapatite powders and their characterisation, 2) the synthesis of crystalline scorodite under atmospheric conditions and its characterisation, 3) the encapsulation of scorodite with hydroxyapatite and fluoroapatite, and 4) the long term stability testing of the encapsulated solids. Hydroxyapatite and fluoroapatite were prepared first by homogeneous precipitation from a metastable solution, to which "Ca" and "PO4" source reagents of different concentrations were added at variable rates. The crystallinity of the produced materials was found to increase with temperature. Crystalline scorodite was produced by seeded crystallisation in ambient pressure. For the encapsulation of the scorodite particles various methods of direct precipitation by controlled supersaturation were attempted, by adjusting the pH and adding/mixing feed solutions of individual calcium and phosphate source reagents. Heterogeneous deposition of HAP on scorodite proved rather difficult. Optimum results were obtained via prior conditioning of the scorodite substrate in a calcium solution and employment of low agitation regime and high (37 °C rather than 22°C) temperature. The stability tests were done in oxic and anoxic environments and their results demonstrated

  15. Excess heat capacity and entropy of mixing along the chlorapatite-fluorapatite binary join

    NASA Astrophysics Data System (ADS)

    Dachs, Edgar; Harlov, Daniel; Benisek, Artur

    2010-10-01

    The heat capacity at constant pressure, C p, of chlorapatite [Ca5(PO4)3Cl - ClAp], and fluorapatite [Ca5(PO4)3F - FAp], as well as of 12 compositions along the chlorapatite-fluorapatite join have been measured using relaxation calorimetry [heat capacity option of the physical properties measurement system (PPMS)] and differential scanning calorimetry (DSC) in the temperature range 5-764 K. The chlor-fluorapatites were synthesized at 1,375-1,220°C from Ca3(PO4)2 using the CaF2-CaCl2 flux method. Most of the chlor-fluorapatite compositions could be measured directly as single crystals using the PPMS such that they were attached to the sample platform of the calorimeter by a crystal face. However, the crystals were too small for the crystal face to be polished. In such cases, where the sample coupling was not optimal, an empirical procedure was developed to smoothly connect the PPMS to the DSC heat capacities around ambient T. The heat capacity of the end-members above 298 K can be represented by the polynomials: C {p/ClAp} = 613.21 - 2,313.90 T -0.5 - 1.87964 × 107 T -2 + 2.79925 × 109 T -3 and C {p/FAp} = 681.24 - 4,621.73 × T -0.5 - 6.38134 × 106 T -2 + 7.38088 × 108 T -3 (units, J mol-1 K-1). Their standard third-law entropy, derived from the low-temperature heat capacity measurements, is S° = 400.6 ± 1.6 J mol-1 K-1 for chlorapatite and S° = 383.2 ± 1.5 J mol-1 K-1 for fluorapatite. Positive excess heat capacities of mixing, Δ C {p/ex}, occur in the chlorapatite-fluorapatite solid solution around 80 K (and to a lesser degree at 200 K) and are asymmetrically distributed over the join reaching a maximum of 1.3 ± 0.3 J mol-1 K-1 for F-rich compositions. They are significant at these conditions exceeding the 2 σ-uncertainty of the data. The excess entropy of mixing, Δ S ex, at 298 K reaches positive values of 3-4 J mol-1 K-1 in the F-rich portion of the binary, is, however, not significantly different from zero across the join within its 2 σ-uncertainty.

  16. Moisture and temperature changes associated with the mid-Holocene Tsuga decline in the northeastern United States

    NASA Astrophysics Data System (ADS)

    Marsicek, Jeremiah P.; Shuman, Bryan; Brewer, Simon; Foster, David R.; Oswald, W. Wyatt

    2013-11-01

    A decline of hemlock (Tsuga) populations at ca 5.5 ka (thousands of calibrated radiocarbon years before 1950 AD) stands out as the most abrupt vegetation change of the Holocene in North America, but remains poorly understood after decades of study. Recent analyses of fossil pollen have revealed a concurrent, abrupt oak (Quercus) decline and increases in the abundance of beech (Fagus) and pine (Pinus) on Cape Cod in eastern Massachusetts, but the replacement of drought-tolerant oaks by moisture-sensitive beeches appears inconsistent with low lake levels in the region at the same time. The oak and beech changes are also limited to coastal areas, and the coastal-inland differences require an explanation. Here, we develop a new lake-level reconstruction from Deep Pond, Cape Cod by using a transect of sediment cores and ground-penetrating radar (GPR) profiles to constrain the past elevations of the sandy, littoral zone of the pond. The reconstruction shows that a series of multi-century episodes of low water coincide with the abrupt hemlock and oak declines, and interrupt subsequent phases of hemlock recovery. The lake-level variations equal precipitation deficits of ˜100 mm superimposed on a Holocene long moisture increase of >400 mm. However, because moisture deficits do not easily explain the oak and beech changes, we also evaluate how the climate preferences of the regional vegetation changed over time by matching the fossil pollen assemblages from Deep Pond with their modern equivalents. Reconstructions of the precipitation requirements of the vegetation correlate well even in detail with the lake-level record (r = 0.88 at Deep Pond), and indicate close tracking of effective moisture (precipitation minus evapotranspiration) by the vegetation despite the abrupt species declines, which could have decoupled climate and vegetation trends. Reconstructions of the temperature preferences of the vegetation indicate that coastal sites may have cooled by 0.5-2.5 °C after

  17. Metal-Organic Frameworks of Pyrazolate Derivatives: Synthesis and Applications for Chemical Sensing, Gas Separation, and Catalysis

    NASA Astrophysics Data System (ADS)

    Kivi, Charlie Eric William

    investigated the many other structures H2BPM can assume in the presence of manganese, cobalt, iron, copper, and europium. Cobalt in particular proved highly tunable with 4 separate structures being synthesized such as [Co2(BPM)2(H2 O)4(Bpy)0.5]n·2DMF·2(H 2O). This was achieved through varying the synthetic conditions. [Co 2(BPM)2(H2O)4(Bpy) 0.5]n·2DMF·2(H2O)and [Eu( BPM)(OAc)]n were further investigated for the oxidation of olefins and luminescence respectively. In Chapter 5, metal complexes Mo(TPM-1)(CO)3, Mo(TPM-2)(CO)3, Pd2(H4TPP )Cl4, and Pd2(TPX)Cl4 were synthesized. The catalytic performance of Mo(TPM-1)(CO) 3 was evaluated and found to be effective for the oxidation of olefins. MOF synthesis was attempted with all four compounds but was ultimately unsuccessful. Although one MOF was produced from Mo(TPM-1)(CO)3, large scale synthesis was not possible preventing full investigation of its properties.

  18. The fluorescence and resonance Rayleigh scattering spectra study on the interactions of palladium (II)-Nootropic chelate with Congo red and their analytical applications

    NASA Astrophysics Data System (ADS)

    Chen, Fang; Peng, Jingdong; Liu, Shaopu; Peng, Huanjun; Pan, Ziyu; Bu, Lingli; Xiao, Huan; Zhang, Ruiwen

    2017-04-01

    A highly sensitive detection approach of resonance Rayleigh scattering spectra (RRS) is firstly applied to analyzing nootropic drugs including piracetam (PIR) and oxiracetam (OXI). In HCl-NaAc buffer solution (pH = 3.0), the OXI chelated with palladium (II) to form the chelate cation [Pd2·OXI]2 +, and then reacted with Congo red (CGR) by virtue of electrostatic attraction and hydrophobic force to form binary complex [Pd2·OXI]. CGR2, which could result in the great enhancement of RRS. The resonance Rayleigh scattering signal was recorded at λex = λem = 375 nm. This mixture complex not only has higher RRS, but also makes contribution to significant increase of fluorescence, and the same phenomena also were discovered in PIR. The enhanced RRS intensity is in proportion to the PIR and OXI concentration in the range of 0.03-3.0 μg mL- 1, and the detection limit (DL) of RRS method for PIR and OXI is 2.3 ng mL- 1 and 9.7 ng mL- 1. In addition, the DL of fluorescence method for PIR and OXI is 8.4 μg mL- 1 and 19.5 μg mL- 1. Obviously, the RRS is the highly sensitive method, and the recoveries of the two kinds of nootropic drugs were range from 100.4% to 101.8.0% with RSD (n = 5) from 1.1% to 3.1% by RRS method. This paper not only investigated the optimum conditions for detecting nootropics with using RRS method, but also focused on the reasons for enhancing RRS intensity and the reaction mechanism, which in order to firm and contract the resultant. Finally, The RRS method has been applied to detect nootropic drugs in human urine samples with satisfactory results. Fig. S2. The effect of ionic strength: Pd (II)-CGR system (curve a); Pd (II)-OXI-CGR system (curve b); Pd (II)-PIR- CGR system (curve c). Pd (II): 2.0 × 10- 4 mol L- 1; CGR: 1.0 × 10- 5 mol L- 1; OXI: 1.5 μg mL- 1; PIR: 2 μg mL- 1; NaCl: 1 mol L- 1. Fig. S3. The effect of time: Pd (II)-OXI-CGR system (curve a); Pd (II)-PIR-CGR system (curve b). Pd (II): 2.0 × 10- 4 mol L- 1; CGR: 1.0 × 10- 5 mol L- 1

  19. Raman spectroscopy of DNA-metal complexes. I. Interactions and conformational effects of the divalent cations: Mg, Ca, Sr, Ba, Mn, Co, Ni, Cu, Pd, and Cd.

    PubMed

    Duguid, J; Bloomfield, V A; Benevides, J; Thomas, G J

    1993-11-01

    Interactions of divalent metal cations (Mg2+, Ca2+, Ba2+, Sr2+, Mn2+, Co2+, Ni2+, Cu2+, Pd2+, and Cd2+) with DNA have been investigated by laser Raman spectroscopy. Both genomic calf-thymus DNA (> 23 kilobase pairs) and mononucleosomal fragments (160 base pairs) were employed as targets of metal interaction in solutions containing 5 weight-% DNA and metal:phosphate molar ratios of 0.6:1. Raman difference spectra reveal that transition metal cations (Mn2+, Co2+, Ni2+, Cu2+, Pd2+, and Cd2+) induce the greatest structural changes in B-DNA. The Raman (vibrational) band differences are extensive and indicate partial disordering of the B-form backbone, reduction in base stacking, reduction in base pairing, and specific metal interaction with acceptor sites on the purine (N7) and pyrimidine (N3) rings. Many of the observed spectral changes parallel those accompanying thermal denaturation of B-DNA and suggest that the metals link the bases of denatured DNA. While exocyclic carbonyls of dT, dG, and dC may stabilize metal ligation, correlation plots show that perturbations of the carbonyls are mainly a consequence of metal-induced denaturation of the double helix. Transition metal interactions with the DNA phosphates are weak in comparison to interactions with the bases, except in the case of Cu2+, which strongly perturbs both base and phosphate group vibrations. On the other hand, the Raman signature of B-DNA is largely unperturbed by Mg2+, Ca2+, Sr2+, and Ba2+, suggesting much weaker interactions of the alkaline earth metals with both base and phosphate sites. A notable exception is a moderate perturbation by alkaline earths of purine N7 sites in 160-base pair DNA, with Ca2+ causing the greatest effect. Correlation plots demonstrate a strong interrelationship between perturbations of Raman bands assigned to ring vibrations of the bases and those of bands assigned to exocyclic carbonyls and backbone phosphodiester groups. However, strong correlations do not occur between

  20. Evaluating process domains in small arid granitic watersheds: Case study of Pima Wash, South Mountains, Sonoran Desert, USA

    NASA Astrophysics Data System (ADS)

    Seong, Yeong Bae; Larson, Phillip H.; Dorn, Ronald I.; Yu, Byung Yong

    2016-02-01

    This paper provides support for the concept of geomorphic process domains developed by Montgomery (1999) by linking geomorphic processes to ecological variations seen in the Pima arid granitic watershed of the Sonoran Desert, Phoenix, Arizona. Closer joint spacing shows a statistically significant correlation with lower percentages of mineral grain attachment as measured by digital image processing of backscattered electron microscope imagery. Lower mineral grain attachment leads to more frequent spalling of rock surfaces, as measured by varnish microlamination (VML) ages of the last spalling event. In contrast, more distant joint spacing leads to in situ 10Be erosion rates of 3.4-8.5 mm/ka and the emergence of low domes and kopje granitic landforms; these low domes also serve as knickpoints along ephemeral washes. Distant jointing thus plays a key role in generating the bare bedrock surfaces that funnel limited precipitation to bedrock margins - enhancing the canopy cover of perennial plants next to the bare bedrock. Joint-influenced geomorphic processes at Pima Wash generate four distinct process domains: (PD1) armored drainage divides; (PD2) slopes with different granite landforms; (PD3) mid- and upper basin channels that mix knickzones, strath floodplains, and sandy alluvial sections; and (PD4) the main ephemeral channel transitioning to the piedmont. Distant jointing promotes bedrock exposure and rock armoring along drainage divides in PD1 that then concentrates runoff and promotes perennial plant growth. More distant joint spacing on slopes in PD2 promotes exposure of granitic bedrock forms that shed overland flow to their margin and promotes flora and fauna growths along the margins of low granitic domes and kopjes. Similarly, wider joint spacing along ephemeral washes in PD3 leads to knickpoints, which in turn act to concentrate moisture immediately downstream. The stream terraces in PD4 influence the ecology through xeric desert pavements on terrace treads

  1. Myogenic constriction is increased in mesenteric resistance arteries from rats with chronic heart failure: instantaneous counteraction by acute AT1 receptor blockade

    PubMed Central

    Gschwend, S; Henning, R H; Pinto, Y M; de Zeeuw, D; van Gilst, W H; Buikema, H

    2003-01-01

    Increased vascular resistance in chronic heart failure (CHF) has been attributed to stimulated neurohumoral systems. However, local mechanisms may also importantly contribute to set arterial tone. Our aim, therefore, was to test whether pressure-induced myogenic constriction of resistance arteries in vitro – devoid of acute effects of circulating factors – is increased in CHF and to explore underlying mechanisms. At 12 weeks after coronary ligation-induced myocardial infarction or SHAM-operations in rats, we studied isolated mesenteric arteries for myogenic constriction, determined as the active constriction (% of passive diameter) in response to stepwise increase in intraluminal pressure (20 – 160 mmHg), in the absence and presence of inhibitors of potentially involved modulators of myogenic constriction. We found that myogenic constriction in mesenteric arteries from CHF rats was markedly increased compared to SHAM over the whole pressure range, the difference being most pronounced at 60 mmHg (24±2 versus 4±3%, respectively, P<0.001). Both removal of the endothelium as well as inhibition of NO production (L-NG-monomethylarginine, 100 μM) significantly increased myogenic constriction (+16 and +25%, respectively), the increase being similar in CHF- and SHAM-arteries (P=NS). Neither endothelin type A (ETA)-receptor blockade (BQ123, 1 μM) nor inhibition of perivascular (sympathetic) nerve conduction (tetrodotoxin, 100 nM) affected the myogenic response in either group. Interestingly, increased myogenic constriction in CHF was fully reversed after angiotensin II type I (AT1)-receptor blockade (candesartan, 100 nM; losartan, 10 μM), which was without effect in SHAM. In contrast, neither angiotensin-converting enzyme (ACE) inhibition (lisinopril, 1 μM; captopril, 10 μM) or AT2-receptor blockade (PD123319, 1 μM), nor inhibition of superoxide production (superoxide dismutase, 50 U ml−1), TXA2-receptor blockade (SQ29,548, 1 μM) or inhibition of cyclooxygenase-derived prostaglandins (indomethacin, 10 μM) affected myogenic constriction. Sensitivity of mesenteric arteries to angiotensin II (10 nM – 100 μM) was increased (P<0.05) in CHF (pD2 7.1±0.4) compared to SHAM (pD2 6.2±0.3), while the sensitivity to KCl and phenylephrine was not different. Our results demonstrate increased myogenic constriction in small mesenteric arteries of rats with CHF, potentially making it an important target for therapy in counteracting increased vascular resistance in CHF. Our results further suggest active and instantaneous participation of AT1-receptors in increased myogenic constriction in CHF, involving increased sensitivity of AT1-receptors rather than apparent ACE-mediated local angiotensin II production. PMID:12890711

  2. Early Supplementation of Phospholipids and Gangliosides Affects Brain and Cognitive Development in Neonatal Piglets123

    PubMed Central

    Liu, Hongnan; Radlowski, Emily C; Conrad, Matthew S; Li, Yao; Dilger, Ryan N; Johnson, Rodney W

    2014-01-01

    Background: Because human breast milk is a rich source of phospholipids and gangliosides and breastfed infants have improved learning compared with formula-fed infants, the importance of dietary phospholipids and gangliosides for brain development is of interest. Objective: We sought to determine the effects of phospholipids and gangliosides on brain and cognitive development. Methods: Male and female piglets from multiple litters were artificially reared and fed formula containing 0% (control), 0.8%, or 2.5% Lacprodan PL-20 (PL-20; Arla Foods Ingredients), a phospholipid/ganglioside supplement, from postnatal day (PD) 2 to PD28. Beginning on PD14, performance in a spatial T-maze task was assessed. At PD28, brain MRI data were acquired and piglets were killed to obtain hippocampal tissue for metabolic profiling. Results: Diet affected maze performance, with piglets that were fed 0.8% and 2.5% PL-20 making fewer errors than control piglets (80% vs. 75% correct on average; P < 0.05) and taking less time to make a choice (3 vs. 5 s/trial; P < 0.01). Mean brain weight was 5% higher for piglets fed 0.8% and 2.5% PL-20 (P < 0.05) than control piglets, and voxel-based morphometry revealed multiple brain areas with greater volumes and more gray and white matter in piglets fed 0.8% and 2.5% PL-20 than in control piglets. Metabolic profiling of hippocampal tissue revealed that multiple phosphatidylcholine-related metabolites were altered by diet. Conclusion: In summary, dietary phospholipids and gangliosides improved spatial learning and affected brain growth and composition in neonatal piglets. PMID:25411030

  3. DNA barcoding to identify leaf preference of leafcutting bees.

    PubMed

    MacIvor, J Scott

    2016-03-01

    Leafcutting bees (Megachile: Megachilidae) cut leaves from various trees, shrubs, wildflowers and grasses to partition and encase brood cells in hollow plant stems, decaying logs or in the ground. The identification of preferred plant species via morphological characters of the leaf fragments is challenging and direct observation of bees cutting leaves from certain plant species are difficult. As such, data are poor on leaf preference of leafcutting bees. In this study, I use DNA barcoding of the rcbL and ITS2 regions to identify and compare leaf preference of three Megachile bee species widespread in Toronto, Canada. Nests were opened and one leaf piece from one cell per nest of the native M. pugnata Say (N=45 leaf pieces), and the introduced M. rotundata Fabricius (N=64) and M. centuncularis (L.) (N=65) were analysed. From 174 individual DNA sequences, 54 plant species were identified. Preference by M. rotundata was most diverse (36 leaf species, H'=3.08, phylogenetic diversity (pd)=2.97), followed by M. centuncularis (23 species, H'=2.38, pd=1.51) then M. pugnata (18 species, H'=1.87, pd=1.22). Cluster analysis revealed significant overlap in leaf choice of M. rotundata and M. centuncularis. There was no significant preference for native leaves, and only M. centuncularis showed preference for leaves of woody plants over perennials. Interestingly, antimicrobial properties were present in all but six plants collected; all these were exotic plants and none were collected by the native bee, M. pugnata. These missing details in interpreting what bees need offers valuable information for conservation by accounting for necessary (and potentially limiting) nesting materials.

  4. A novel three-dimensional dynamic anorectal ultrasonography technique for the assessment of perineal descent, compared with defaecography.

    PubMed

    Murad-Regadas, S M; dos Santos, D; Soares, G; Regadas, F S P; Rodrigues, L V; Buchen, G; Kenmoti, V T; Surimã, W S; Fernandes, G O da S

    2012-06-01

    The purpose of the study was to describe a novel three-dimensional dynamic anorectal ultrasonography technique (dynamic 3-DAUS) for assessment of perineal descent (PD) and establishment of normal range values, comparing it with defaecography. Secondarily, the study compares the ability of the two techniques to identify various pelvic floor dysfunctions. A prospective study was undertaken in 29 women (mean age 43 years) with obstructed defecation disorder. All patients underwent defaecography and dynamic 3-DAUS and the results were compared. Lee kappa coefficients (K) were used. On defaecography, PD > 3 cm was detected in 12 patients. On dynamic 3-DAUS, 10 of these patients had PD > 2.5 cm. Seventeen had normal PD on defaecography and PD ≤ 2.5 cm on dynamic 3-DAUS (K 0.85). Normal relaxation was observed in 10 patients and anismus in 14 with both techniques (K 0.65). Both techniques identified five patients without rectocele, two with grade I rectocele (K 0.89 and 1.00, respectively) and 10 with grade II and nine with grade III (K 0.72 and 0.77, respectively). Rectal intussusception was identified in six patients on defaecography. These were confirmed on dynamic 3-DAUS in addition to the identification of another seven cases indicating moderate agreement (K 0.46). Enterocele/sigmoidocele grade III was identified in one patient with both techniques, indicating substantial agreement (K 0.65). Dynamic 3-DAUS was shown to be a reliable technique for the assessment of PD and pelvic floor dysfunctions, identifying all disorders and confirming findings from defaecography. © 2011 The Authors. Colorectal Disease © 2011 The Association of Coloproctology of Great Britain and Ireland.

  5. 250 Robotic Pancreatic Resections: Safety and Feasibility

    PubMed Central

    Zureikat, Amer H.; Moser, A. James; Boone, Brian A.; Bartlett, David L.; Zenati, Mazen; Zeh, Herbert J.

    2015-01-01

    Background and Objectives Computer Assisted Robotic Surgery allows complex resections and anastomotic reconstructions to be performed with nearly identical standards to open surgery. We applied this technology to a variety of pancreatic resections to assess the safety, feasibility, versatility and reliability of this technology. Methods A retrospective review of a prospective database of robotic pancreatic resections at a single institution between August 2008 and November 2012 was performed. Peri-operative outcomes were analyzed. Results 250 consecutive robotic pancreatic resections were analyzed; pancreaticoduodenectomy (PD =132), distal pancreatectomy (DP=83), central pancreatectomy (CP=13), pancreatic enucleation (10), total pancreatectomy (TP=5), Appleby resection (4), and Frey procedure (3). Thirty day and 90 day mortality was 0.8 % and 2.0%. Rate of Clavien 3 and 4 complications was 14 and 6 %. The ISGPF grade C fistula rate was 4%. Mean operative time for the two most common procedures was 529 ± 103 mins for PD, and 257 ± 93 mins for DP. Continuous improvement in operative times was observed over the course of the experience. Conversion to open procedure was required in 16 patients (6%);(11 PD, 2 DP, 2 CP, 1 TP) for failure to progress (14) and bleeding (2). Conclusions This represents to our knowledge the largest series of robotic pancreatic resections. Safety and feasibility metrics including the low incidence of conversion support the robustness of this platform and suggest no unanticipated risks inherent to this new technology. By defining these early outcome metrics this report begins to establish a framework for comparative effectiveness studies of this platform. PMID:24002300

  6. DNA barcoding to identify leaf preference of leafcutting bees

    PubMed Central

    2016-01-01

    Leafcutting bees (Megachile: Megachilidae) cut leaves from various trees, shrubs, wildflowers and grasses to partition and encase brood cells in hollow plant stems, decaying logs or in the ground. The identification of preferred plant species via morphological characters of the leaf fragments is challenging and direct observation of bees cutting leaves from certain plant species are difficult. As such, data are poor on leaf preference of leafcutting bees. In this study, I use DNA barcoding of the rcbL and ITS2 regions to identify and compare leaf preference of three Megachile bee species widespread in Toronto, Canada. Nests were opened and one leaf piece from one cell per nest of the native M. pugnata Say (N=45 leaf pieces), and the introduced M. rotundata Fabricius (N=64) and M. centuncularis (L.) (N=65) were analysed. From 174 individual DNA sequences, 54 plant species were identified. Preference by M. rotundata was most diverse (36 leaf species, H′=3.08, phylogenetic diversity (pd)=2.97), followed by M. centuncularis (23 species, H′=2.38, pd=1.51) then M. pugnata (18 species, H′=1.87, pd=1.22). Cluster analysis revealed significant overlap in leaf choice of M. rotundata and M. centuncularis. There was no significant preference for native leaves, and only M. centuncularis showed preference for leaves of woody plants over perennials. Interestingly, antimicrobial properties were present in all but six plants collected; all these were exotic plants and none were collected by the native bee, M. pugnata. These missing details in interpreting what bees need offers valuable information for conservation by accounting for necessary (and potentially limiting) nesting materials. PMID:27069650

  7. A novel miniature in-line load-cell to measure in-situ tensile forces in the tibialis anterior tendon of rats

    PubMed Central

    Unger, Ewald; Bijak, Manfred; Stoiber, Martin; Lanmüller, Hermann; Jarvis, Jonathan Charles

    2017-01-01

    Direct measurements of muscular forces usually require a substantial rearrangement of the biomechanical system. To circumvent this problem, various indirect techniques have been used in the past. We introduce a novel direct method, using a lightweight (~0.5 g) miniature (3 x 3 x 7 mm) in-line load-cell to measure tension in the tibialis anterior tendon of rats. A linear motor was used to produce force-profiles to assess linearity, step-response, hysteresis and frequency behavior under controlled conditions. Sensor responses to a series of rectangular force-pulses correlated linearly (R2 = 0.999) within the range of 0–20 N. The maximal relative error at full scale (20 N) was 0.07% of the average measured signal. The standard deviation of the mean response to repeated 20 N force pulses was ± 0.04% of the mean response. The step-response of the load-cell showed the behavior of a PD2T2-element in control-engineering terminology. The maximal hysteretic error was 5.4% of the full-scale signal. Sinusoidal signals were attenuated maximally (-4 dB) at 200 Hz, within a measured range of 0.01–200 Hz. When measuring muscular forces this should be of minor concern as the fusion-frequency of muscles is generally much lower. The newly developed load-cell measured tensile forces of up to 20 N, without inelastic deformation of the sensor. It qualifies for various applications in which it is of interest directly to measure forces within a particular tendon causing only minimal disturbance to the biomechanical system. PMID:28934327

  8. A novel miniature in-line load-cell to measure in-situ tensile forces in the tibialis anterior tendon of rats.

    PubMed

    Schmoll, Martin; Unger, Ewald; Bijak, Manfred; Stoiber, Martin; Lanmüller, Hermann; Jarvis, Jonathan Charles

    2017-01-01

    Direct measurements of muscular forces usually require a substantial rearrangement of the biomechanical system. To circumvent this problem, various indirect techniques have been used in the past. We introduce a novel direct method, using a lightweight (~0.5 g) miniature (3 x 3 x 7 mm) in-line load-cell to measure tension in the tibialis anterior tendon of rats. A linear motor was used to produce force-profiles to assess linearity, step-response, hysteresis and frequency behavior under controlled conditions. Sensor responses to a series of rectangular force-pulses correlated linearly (R2 = 0.999) within the range of 0-20 N. The maximal relative error at full scale (20 N) was 0.07% of the average measured signal. The standard deviation of the mean response to repeated 20 N force pulses was ± 0.04% of the mean response. The step-response of the load-cell showed the behavior of a PD2T2-element in control-engineering terminology. The maximal hysteretic error was 5.4% of the full-scale signal. Sinusoidal signals were attenuated maximally (-4 dB) at 200 Hz, within a measured range of 0.01-200 Hz. When measuring muscular forces this should be of minor concern as the fusion-frequency of muscles is generally much lower. The newly developed load-cell measured tensile forces of up to 20 N, without inelastic deformation of the sensor. It qualifies for various applications in which it is of interest directly to measure forces within a particular tendon causing only minimal disturbance to the biomechanical system.

  9. Periodontal Health in Women With Early-Stage Postmenopausal Breast Cancer Newly on Aromatase Inhibitors: A Pilot Study.

    PubMed

    Taichman, L Susan; Inglehart, Marita R; Giannobile, William V; Braun, Thomas; Kolenic, Giselle; Van Poznak, Catherine

    2015-07-01

    Aromatase inhibitor (AI) use results in low estrogen levels, which in turn affect bone mineral density (BMD). Periodontitis, alveolar bone loss, and tooth loss are associated with low BMD. The goal of this study is to assess the prevalence of periodontitis and perceived oral health and evaluate salivary biomarkers in postmenopausal women who are survivors of early-stage (I to IIIA) breast cancer (BCa) and receive adjuvant AI therapy. Participants included 58 postmenopausal women: 29 with BCa on AIs and 29 controls without BCa diagnoses. Baseline periodontal status was assessed with: 1) periodontal probing depth (PD); 2) bleeding on probing (BOP); and 3) attachment loss (AL). Demographic and dental utilization information was gathered by questionnaire. Linear regression modeling was used to analyze the outcomes. No differences were found in mean PD or number of teeth. The AI group had significantly more sites with BOP (27.8 versus 16.7; P = 0.02), higher worst-site AL (5.2 versus 4.0 mm; P <0.01), and more sites with dental calculus (18.2 versus 6.4; P <0.001) than controls. Linear regression adjusted for income, tobacco use, dental insurance, and previous radiation and chemotherapy exposure demonstrated that AI use increased AL by >2 mm (95% confidence interval, 0.46 to 3.92). Median salivary osteocalcin and tumor necrosis factor-α levels were significantly higher in the AI group than the control group. This first investigation of the periodontal status of women initiating adjuvant AI therapy identifies this population as having an increased risk for periodontitis.

  10. Involvement of thromboxane A2 in the endothelium-dependent contractions induced by myricetin in rat isolated aorta

    PubMed Central

    Jiménez, Rosario; Andriambeloson, Emile; Duarte, Juan; Andriantsitohaina, Ramaroson; Jiménez, José; Pérez-Vizcaino, Francisco; Zarzuelo, Antonio; Tamargo, Juan

    1999-01-01

    The present study was undertaken to analyse the mechanism of the contractile response induced by the bioflavonoid myricetin in isolated rat aortic rings.Myricetin induced endothelium-dependent contractile responses (maximal value=21±2% of the response induced by 80 mM KCl and pD2=5.12±0.03). This effect developed slowly, reached a peak within 6 min and then declined progressively.Myricetin-induced contractions were almost abolished by the phospholipase A2 (PLA2) inhibitor, quinacrine (10 μM), the cyclo-oxygenase inhibitor, indomethacin (10 μM), the thromboxane synthase inhibitor, dazoxiben (100 μM), the putative thromboxane A2 (TXA2)/prostaglandin endoperoxide receptor antagonist, ifetroban (3 μM). These contractions were abolished in Ca2+-free medium but were not affected by the Ca2+ channel blocker verapamil (10 μM).In cultured bovine endothelial cells (BAEC), myricetin (50 μM) produced an increase in cytosolic free calcium ([Ca2+]i) which peaked within 1 min and remained sustained for 6 min, as determined by the fluorescent probe fura 2. This rise in [Ca2+]i was abolished after removal of extracellular Ca2+ in the medium.Myricetin (50 μM) significantly increased TXB2 production both in aortic rings with and without endothelium and in BAEC. These increases were abolished both by Ca2+-free media and by indomethacin.Taken together, these results suggests that myricetin stimulates Ca2+ influx and subsequently triggers the activation of the PLA2 and cyclo-oxygenase pathways releasing TXA2 from the endothelium to contract rat aortic rings. The latter response occurs via the activation of Tp receptors on vascular smooth muscle cells. PMID:10455307

  11. Combination of Ultrasonic Decontamination, Soft Tissue Curettage and Submucosal Air Polishing With Povidone-Iodine Application for Non-Surgical Therapy of Peri-Implantitis: 12 Months Clinical Outcomes.

    PubMed

    Stein, Jamal M; Hammächer, Christian; Said-Yekta Michael, Sareh

    2017-09-15

    The aim of this study was to evaluate the clinical outcomes of a concept for non-surgical peri-implantitis combining stepwise mechanical debridement measures with adjuvant Povidone-iodine application with and without systemic antibiotics. 45 patients with chronic periodontitis comprising 164 screw-typed implants with peri-implantitis were included. Peri-implantitis was defined as radiographic bone loss of >2 mm, probing pocket depth (PD) ≥5 mm with bleeding on probing (BOP). Stepwise treatment of implants was performed with ultrasonic debridement, soft tissue curettage (STC), glycine powder air polishing (GPAP) and a repeated submucosal application of Povidone-iodine. Teeth with PD >4mm were treated simultaneously according to the same concept except STC. In cases with severe periodontitis (N = 24), amoxicillin and metronidazole (AM) were prescribed for 7 days. After 12 months, implants treated without AM showed significant reductions (p<0.05) of mean PD (1.4 ± 0.7 mm), CAL (1.3 ± 0.8 mm) and BOP (33.4 ± 17.2%). In deep pockets (PD >6mm) changes of mean PD (2.3 ± 1.3 mm), CAL (2.0 ± 1.6 mm) and BOP (44.0 ± 41.7%) were more pronounced. Intake of AM did not significantly influence the changes of these parameters. However, the reduction of implant sites with PD >4 mm and BOP was significantly higher in patients with AM than in those without AM (31.8 ± 12.6% vs. 20.8 ± 14.7%; p<0.05). The combination of ultrasonic debridement, STC and GPAP with adjuvant Povidone-iodine led to significant clinical improvements at implants. Systemic antibiotics had limited effects on the reduction of persisting implant sites with treatment need.

  12. Development of large-scale manufacturing of adipose-derived stromal cells for clinical applications using bioreactors and human platelet lysate.

    PubMed

    Haack-Sørensen, Mandana; Juhl, Morten; Follin, Bjarke; Harary Søndergaard, Rebekka; Kirchhoff, Maria; Kastrup, Jens; Ekblond, Annette

    2018-04-17

    In vitro expanded adipose-derived stromal cells (ASCs) are a useful resource for tissue regeneration. Translation of small-scale autologous cell production into a large-scale, allogeneic production process for clinical applications necessitates well-chosen raw materials and cell culture platform. We compare the use of clinical-grade human platelet lysate (hPL) and fetal bovine serum (FBS) as growth supplements for ASC expansion in the automated, closed hollow fibre quantum cell expansion system (bioreactor). Stromal vascular fractions were isolated from human subcutaneous abdominal fat. In average, 95 × 10 6 cells were suspended in 10% FBS or 5% hPL medium, and loaded into a bioreactor coated with cryoprecipitate. ASCs (P0) were harvested, and 30 × 10 6 ASCs were reloaded for continued expansion (P1). Feeding rate and time of harvest was guided by metabolic monitoring. Viability, sterility, purity, differentiation capacity, and genomic stability of ASCs P1 were determined. Cultivation of SVF in hPL medium for in average nine days, yielded 546 × 10 6 ASCs compared to 111 × 10 6 ASCs, after 17 days in FBS medium. ASCs P1 yields were in average 605 × 10 6 ASCs (PD [population doublings]: 4.65) after six days in hPL medium, compared to 119 × 10 6 ASCs (PD: 2.45) in FBS medium, after 21 days. ASCs fulfilled ISCT criteria and demonstrated genomic stability and sterility. The use of hPL as a growth supplement for ASCs expansion in the quantum cell expansion system provides an efficient expansion process compared to the use of FBS, while maintaining cell quality appropriate for clinical use. The described process is an obvious choice for manufacturing of large-scale allogeneic ASC products.

  13. Reduced Sodium Transport With Nasal Administration of the Prostasin Inhibitor Camostat in Subjects With Cystic Fibrosis

    PubMed Central

    Reeves, Ginger; Hathorne, Heather; Solomon, G. Martin; Abbi, Smita; Renard, Didier; Lock, Ruth; Zhou, Ping; Danahay, Henry; Clancy, John P.; Waltz, David A.

    2013-01-01

    Background: Prostasin, a trypsin-like serine protease, is a channel-activating protease and major regulator of epithelial sodium channel-mediated sodium absorption. Its direct inhibition by camostat represents a potential approach to inhibiting sodium transport in cystic fibrosis (CF). Methods: To determine whether a topical formulation of camostat represents an efficacious and tolerable approach to reducing Na+ transport in the CF airway, we conducted a two-part randomized, double-blind, placebo-controlled, crossover, ascending single-dose study to evaluate the pharmacodynamics, safety, and pharmacokinetics of camostat administered through a nasal spray pump in subjects with CF. Nasal potential difference (PD) was measured before and after treatment, and safety and pharmacokinetics were assessed by a standardized approach. Results: In part 1, nine subjects were enrolled, and six completed crossover dosing at the maximally tolerated dose. The change in maximal (most polarizing) basal PD 2 h following administration of camostat was +13.1 mV (1.6-mg dose group) compared with −8.6 mV following placebo (P < .005). Intrasubject change in Ringer and amiloride-sensitive PDs exhibited similar and consistent responses. Bayesian analysis in an additional six subjects in part 2 estimated a dose of 18 μg/mL to provide 50% of the maximum effect. There was no significant change in chloride transport or total nasal symptom score, nasal examination rating, and laboratory parameters. Conclusions: This study establishes the proof of concept that a reduction in sodium transport in the human CF airway can be achieved through inhibition of prostasin activity, identifying a potential therapeutic target in the disease. Trial registration: ClinicalTrials.gov; No.: NCT00506792; URL: www.clinicaltrials.gov PMID:23412700

  14. Employment as a welder and Parkinson disease among heavy equipment manufacturing workers.

    PubMed

    Marsh, Gary M; Gula, Mary Jean

    2006-10-01

    We investigated whether employment as a welder with potential exposure to manganese and other substances is associated with Parkinson disease (PD), parkinsonism or related neurological disorders, or accelerates the age of onset of PD. We selected cases and controls from 12,595 persons ever employed at three Caterpillar Inc. (CAT) plants between 1976 and 2004 with potential to make a medical insurance claim between 1998 and 2004. Cases had filed a claim for 1) PD, 2) "secondary parkinsonism", 3) "other degenerative diseases of the basal ganglia" or 4) "essential and other specific forms of tremor". Cases were grouped by claims: Group 1-claims 1 and 2 and Group 2-claims 1 to 4, and as study period incident (SPI) or prevalent. Each case was matched to two series of 10 controls each on date of case's first claim, year of birth, race and sex. Series I was also matched on plant. Odds ratios (OR) and 95% confidence intervals (CI) for the variable, "ever welder in any CAT plant" were: Group 1-SPI Cases: Series I (OR = .76, CI = .26-2.19), Series II (OR = .81, CI = .29-2.25); Group 1- Prevalent Cases: Series I (OR = .82, CI = .36-1.86), Series II (OR = .97, CI = .42-2.23); Group 2- SPI Cases: Series I (OR = 1.03, CI = .57-1.87), Series II (OR = 1.21, CI = .67-2.20) Group 2-Prevalent Cases: Series I (OR = 1.02, CI = .62-1.71), Series II (OR = .86, CI = .51-1.43). Our finding of no statistically significant associations for welding employment was maintained following adjustment for potential confounding and evaluation of possible effect modification. Employment as a welder did not accelerate the age of onset of PD. Our study supported the conclusion that employment as a welder is not associated with Parkinson disease, parkinsonism or a related neurological disorder.

  15. White matter integrity and cognition in Parkinson's disease: a cross-sectional study

    PubMed Central

    Auning, Eirik; Kjærvik, Veslemøy Krohn; Selnes, Per; Aarsland, Dag; Haram, Astrid; Bjørnerud, Atle; Hessen, Erik; Esnaashari, Abdolreza; Fladby, Tormod

    2014-01-01

    Objective We used diffusion tensor imaging (DTI) to test the following hypotheses: (1) there is decreased white matter (WM) integrity in non-demented Parkinson’s disease (PD), (2) WM integrity is differentially reduced in PD and early Alzheimer’s disease (AD) and (3) DTI changes in non-demented PD are specifically associated with cognitive performance. Methods This study included 18 non-demented patients with PD, 18 patients with mild cognitive impairment due to incipient AD and 19 healthy elderly normal control (NC) participants in a cross-sectional design. The participants underwent DTI, and tract-based spatial statistics was used to analyse and extract radial diffusivity and fractional anisotropy. Correlations between scores from a battery of neuropsychological tests and DTI were performed in the PD group. Results Patients with PD had significant differences in DTI in WM underlying the temporal, parietal and occipital cortex as compared with NC. There were no significant differences between the PD and AD groups in the primary region of interest analyses, but compared with NC there was a tendency for more anterior changes in AD in contrast to more posterior changes in PD. In a secondary whole-brain analysis there were frontoparietal areas with significant differences between AD and PD. In patients with PD, there were significant correlations between DTI parameters in WM underlying the prefrontal cortex and executive and visuospatial abilities. Conclusions In early, non-demented PD we found reduced WM integrity underlying the temporal, parietal and occipital cortices. In addition, WM integrity changes in prefrontal areas were associated with executive and visuospatial ability. These findings support that DTI may be an important biomarker in early PD, and that WM changes are related to cognitive impairment in PD. PMID:24448846

  16. Diadenosine tetraphosphate as a potential therapeutic nucleotide to treat glaucoma.

    PubMed

    Fonseca, Begoña; Martínez-Águila, Alejandro; de Lara, María J Pérez; Pintor, Jesús

    2017-06-01

    Glaucoma is a neurodegenerative disease that produces blindness. The main factor associated with this disease is an abnormally elevated intraocular pressure (IOP). To date, some attempts have been made to demonstrate the role of nucleotides modulating IOP, but never in a model of glaucoma. The DBA/2J mouse is an animal that develops the pathology spontaneously, starting from the typical rise in IOP at 9 months of age. Using this animal model, together with a control mouse, C57BL/6J, it has been possible to monitor the elevation in IOP in the glaucomatous mice and to check the ability of the dinucleotide diadenosine tetraphosphate AKA Ap 4 A to reduce IOP. The topical application of Ap 4 A when IOP is maximal (9-12 months) reduced IOP 30.6 ± 6.6% in the DBA/2J and 17.9 ± 4.0% in the C57BL/6J mice. Concentration response curves in both animal strains produced similar pD2 values; these being 4.9 ± 0.5 and 5.1 ± 0.4 for the normotensive C57BL/6J and the glaucomatous DBA/2J respectively. Antagonist studies showed differences between the control and the glaucomatous animals. In particular, the main receptor reducing IOP in the control animal was the P2Y 1 receptor and in the glaucomatous model the P2Y 6 , although the participation of other P2 receptors cannot be ruled out. The long-term effect of Ap 4 A applied three times a week for 3 months showed a clear stop in the elevation of IOP in the glaucomatous model, thus indicating the possibility of using Ap 4 A as an effective compound for the treatment of glaucoma.

  17. Evidence of changes in alpha-1/AT1 receptor function generated by diet-induced obesity.

    PubMed

    Juarez, Esther; Tufiño, Cecilia; Querejeta, Enrique; Bracho-Valdes, Ismael; Bobadilla-Lugo, Rosa A

    2017-11-01

    To study whether hypercaloric diet-induced obesity deteriorates vascular contractility of rat aorta through functional changes in α 1 adrenergic and/or AT1 Angiotensin II receptors. Angiotensin II- or phenylephrine-induced contraction was tested on isolated aorta rings with and without endothelium from female Wistar rats fed for 7 weeks with hypercaloric diet or standard diet. Vascular expression of Angiotensin II Receptor type 1 (AT1R), Angiotensin II Receptor type 2 (AT2R), Cyclooxygenase-1 (COX-1), Cyclooxygenase-2 (COX-2), inducible Nitric Oxide Synthase (iNOS) and endothelial Nitric Oxide Synthase (eNOS), as well as blood pressure, glucose, insulin and angiotensin II blood levels were measured. Diet-induced obesity did not significantly change agonist-induced contractions (Emax and pD 2 hypercaloric diet vs standard diet n.s.d.) of both intact (e+) or endothelium free (e-) vessels but significantly decrease both phenylephrine and angiotensin II contraction (Emax p < 0.01 hypercaloric diet vs standard diet) in the presence of both prazosin and losartan but only in endothelium-intact vessels. Diet-induced obesity did not change angiotensin II AT1, AT2 receptor proteins expression but reduced COX-1 and NOS2 ( p < 0.05 vs standard diet). Seven-week hypercaloric diet-induced obesity produces alterations in vascular adrenergic and angiotensin II receptor dynamics that suggest an endothelium-dependent adrenergic/angiotensin II crosstalk. These changes reflect early-stage vascular responses to obesity.

  18. The relationship between the microstructure and magnetic properties of sputtered Co/Pt multilayer films

    NASA Astrophysics Data System (ADS)

    Kim, Y. H.; Petford-Long, Amanda K.; Jakubovics, J. P.

    1994-11-01

    Co/Pd multilayer films (MLFs) are of interest because of their potential application as high-density magneto-optical recording media. Co/Pd MLFs with varying Co and Pd layer thicknesses were grown by sputter-deposition onto (100) Si wafers. X-ray diffraction and high resolution electron microscopy were used to study the microstructure of the films, and Lorentz microscopy was used to analyze their magnetic domain structure. The films show an fcc crystal structure with a compromised lattice parameter and a strong (111) crystallographic texture in the growth direction. The compromised interplanar spacing parallel to the surface increased with decreasing thickness ratio (t(sub Co)/t(sub Pd), and the columnar grain size decreased with increasing Pd layer thickness. Films with t(sub Co) = 0.35 nm and t(sub Pd) = 2.8 nm (columnar grain diameter 20 nm) showed promising magnetic properties, namely a high perpendicular magnetic anisotropy (1.85x10(exp 5) J/cu m), with a perpendicular coercivity of 98.7 kA/m, a perpendicular remanence ratio of 99%, and a perpendicular coercivity ratio of 88%. The magnetic domains were uniform and of a narrow stripe type, confirming the perpendicular easy axis of magnetization. The Curie temperature was found to be about 430 C. Films of pure Co and Pd, grown for comparison, also showed columnar grain structure with grain-sizes of the same order as those seen in the MLFs. In addition the Pd films showed a (111) textured fcc structure.

  19. The electrocatalytic reduction of nitrate in water on Pd/Sn-modified activated carbon fiber electrode.

    PubMed

    Wang, Ying; Qu, Jiuhui; Wu, Rongcheng; Lei, Pengju

    2006-03-01

    The Pd/Sn-modified activated carbon fiber (ACF) electrodes were successfully prepared by the impregnation of Pd2+ and Sn2+ ions onto ACF, and their electrocatalytic reduction capacity for nitrate ions in water was evaluated in a batch experiment. The electrode was characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectrum (XPS) and temperature programmed reduction (TPR). The capacity for nitrate reduction depending on Sn content on the electrode and the pH of electrolyte was discussed at length. The results showed that at an applied current density of 1.11 mA cm(-2), nitrate ions in water (solution volume: 400 mL) were reduced from 110 to 3.4 mg L(-1) after 240 min with consecutive change of intermediate nitrite. Ammonium ions and nitrogen were formed as the main final products. The amount of other possible gaseous products (including NO and N2O) was trace. With the increase of Sn content on the Pd/Sn-modified ACF electrode, the activity for nitrate reduction went up to reach a maximum (at Pd/Sn = 4) and then decreased, while the selectivity to N2 was depressed. Higher pH value of electrolyte exhibited more suppression effect on the reduction of nitrite than that of nitrate. However, no significant influence on the final ammonia formation was observed. Additionally, Cu ion in water was found to cover the active sites of the electrode to make the electrode deactivated.

  20. State Anxiety and Nonlinear Dynamics of Heart Rate Variability in Students.

    PubMed

    Dimitriev, Dimitriy A; Saperova, Elena V; Dimitriev, Aleksey D

    2016-01-01

    Clinical and experimental research studies have demonstrated that the emotional experience of anxiety impairs heart rate variability (HRV) in humans. The present study investigated whether changes in state anxiety (SA) can also modulate nonlinear dynamics of heart rate. A group of 96 students volunteered to participate in the study. For each student, two 5-minute recordings of beat intervals (RR) were performed: one during a rest period and one just before a university examination, which was assumed to be a real-life stressor. Nonlinear analysis of HRV was performed. The Spielberger's State-Trait Anxiety Inventory was used to assess the level of SA. Before adjusting for heart rate, a Wilcoxon matched pairs test showed significant decreases in Poincaré plot measures, entropy, largest Lyapunov exponent (LLE), and pointwise correlation dimension (PD2), and an increase in the short-term fractal-like scaling exponent of detrended fluctuation analysis (α1) during the exam session, compared with the rest period. A Pearson analysis indicated significant negative correlations between the dynamics of SA and Poincaré plot axes ratio (SD1/SD2), and between changes in SA and changes in entropy measures. A strong negative correlation was found between the dynamics of SA and LLE. A significant positive correlation was found between the dynamics of SA and α1. The decreases in Poincaré plot measures (SD1, complex correlation measure), entropy measures, and LLE were still significant after adjusting for heart rate. Corrected α1 was increased during the exam session. As before, the dynamics of adjusted LLE was significantly correlated with the dynamics of SA. The qualitative increase in SA during academic examination was related to the decrease in the complexity and size of the Poincaré plot through a reduction of both the interbeat interval and its variation.

  1. The effect of boric acid on acethylcholine, bethanechol and potasssium-evoked responses on ileum of rat.

    PubMed

    Ince, S; Turkmen, R; Yavuz, H

    2011-01-01

    1 The aim of this study was to clarify the effect of boric acid on contractions of rat isolated ileum. 2 Contractile responses expressed as Emax and pD2 for acetylcholine (10(-3)-10(-8) m, Ach), bethanechol (10(-3)-10(-8) m) and potassium (10-80 × 10(-3) m, KCl) were determined in the absence and presence of boric acid (10(-3); 5 × 10(-4); 10(-4) m). 3 The contractile response to Ach in the presence of verapamil (10(-6) or 10(-8) m) or in calcium-free Tyrode's solution was also determined in the absence and presence of boric acid. 4 Boric acid did not affect the contractile response to Ach, bethanechol or KCl. Single or cumulative treatment of boric acid did not affect ileum muscle contraction evoked by KCl. The atropine-resistant component of Ach-induced contraction and 4-diphenyl-acetoxy-N-methyl-piperidine methiodide-resistant component of bethanechol-induced contraction were not inhibited by boric acid (10(-3) m). The contractile response to Ach was reduced in calcium-free Tyrode's solution, and the contractile response was not affected by (10(-8) m). The addition of boric acid (10(-3) m) in combination with verapamil (10(-8) m) did not significantly affect the contractile response to Ach. 5 In conclusion, boric acid does not affect contractions induced by Ach, bethanechol or potassium in rat isolated ileum. © 2011 Blackwell Publishing Ltd.

  2. Periodontal disease and diabetes mellitus.

    PubMed

    Negrato, Carlos Antonio; Tarzia, Olinda; Jovanovič, Lois; Chinellato, Luiz Eduardo Montenegro

    2013-01-01

    Periodontal disease (PD) is one of the most commonly known human chronic disorders. The relationship between PD and several systemic diseases such as diabetes mellitus (DM) has been increasingly recognized over the past decades. The purpose of this review is to provide the reader with knowledge concerning the relationship between PD and DM. Many articles have been published in the English and Portuguese literature over the last 50 years examining the relationship between these two chronic diseases. Data interpretation is often confounded by varying definitions of DM, PD and different clinical criteria were applied to determine the prevalence, extent and severity of PD, levels of glycemic control and diabetes-related complications. This paper provides a broad overview of the predominant findings from research conducted using the BBO (Bibliografia Brasileira de Odontologia), MEDLINE, LILACS and PubMed for Controlled Trials databases, in English and Portuguese languages published from 1960 to October 2012. Primary research reports on investigations of relationships between DM/DM control, PD/periodontal treatment and PD/DM/diabetes-related complications identified relevant papers and meta-analyses published in this period. This paper describes the relationship between PD and DM and answers the following questions: 1- The effect of DM on PD, 2- The effects of glycemic control on PD and 3- The effects of PD on glycemic control and on diabetes-related complications. The scientific evidence reviewed supports diabetes having an adverse effect on periodontal health and PD having an adverse effect on glycemic control and on diabetes-related complications. Further research is needed to clarify these relationships and larger, prospective, controlled trials with ethnically diverse populations are warranted to establish that treating PD can positively influence glycemic control and possibly reduce the burden of diabetes-related complications.

  3. Influence of acute treatment with sibutramine on the sympathetic neurotransmission of the young rat vas deferens.

    PubMed

    de Souza, Bruno Palmieri; da Silva, Edilson Dantas; Jurkiewicz, Aron; Jurkiewicz, Neide Hyppolito

    2014-09-05

    The effects of acute treatment with sibutramine on the peripheral sympathetic neurotransmission in vas deferens of young rats were still not evaluated. Therefore, we carried out this study in order to verify the effects of acute sibutramine treatment on the neuronal- and exogenous agonist-induced contractions of the young rat vas deferens. Young 45-day-old male Wistar rats were pretreated with sibutramine 6 mg/kg and after 4h the vas deferens was used for experiment. The acute treatment with sibutramine was able to increase the potency (pD2) of noradrenaline and phenylephrine. Moreover, the efficacy (Emax) of noradrenaline was increased while the efficacy of serotonin and nicotine were decreased. The maximum effect induced by a single concentration of tyramine was diminished in the vas deferens from treated group. Moreover, the leftward shift of the noradrenaline curves promoted by uptake blockers (cocaine and corticosterone) and β-adrenoceptor antagonist (propranolol) was reduced in the vas deferens of treated group. The initial phasic and secondary tonic components of the neuronal-evoked contractions of vas deferens from treated group at the frequencies of 2 Hz were decreased. Moreover, only the initial phasic component at 5 Hz was diminished by the acute treatment with sibutramine. In conclusion, we showed that the acute treatment with sibutramine in young rats was able to affect the peripheral sympathetic nervous system by inhibition of noradrenaline uptake and reduction of the neuronal content of this neurotransmitter, leading to an enhancement of vas deferens sensitivity to noradrenaline. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Mixing of Exciton and Charge-Transfer States in Photosystem II Reaction Centers: Modeling of Stark Spectra with Modified Redfield Theory

    PubMed Central

    Novoderezhkin, Vladimir I.; Dekker, Jan P.; van Grondelle, Rienk

    2007-01-01

    We propose an exciton model for the Photosystem II reaction center (RC) based on a quantitative simultaneous fit of the absorption, linear dichroism, circular dichroism, steady-state fluorescence, triplet-minus-singlet, and Stark spectra together with the spectra of pheophytin-modified RCs, and so-called RC5 complexes that lack one of the peripheral chlorophylls. In this model, the excited state manifold includes a primary charge-transfer (CT) state that is supposed to be strongly mixed with the pure exciton states. We generalize the exciton theory of Stark spectra by 1), taking into account the coupling to a CT state (whose static dipole cannot be treated as a small parameter in contrast to usual excited states); and 2), expressing the line shape functions in terms of the modified Redfield approach (the same as used for modeling of the linear responses). This allows a consistent modeling of the whole set of experimental data using a unified physical picture. We show that the fluorescence and Stark spectra are extremely sensitive to the assignment of the primary CT state, its energy, and coupling to the excited states. The best fit of the data is obtained supposing that the initial charge separation occurs within the special-pair PD1PD2. Additionally, the scheme with primary electron transfer from the accessory chlorophyll to pheophytin gave a reasonable quantitative fit. We show that the effectiveness of these two pathways is strongly dependent on the realization of the energetic disorder. Supposing a mixed scheme of primary charge separation with a disorder-controlled competition of the two channels, we can explain the coexistence of fast sub-ps and slow ps components of the Phe-anion formation as revealed by different ultrafast spectroscopic techniques. PMID:17526589

  5. Progress of pancreatitis disease biomarker alpha amylase enzyme by new nano optical sensor.

    PubMed

    Attia, M S; Al-Radadi, Najlaa S

    2016-12-15

    A new nano optical sensor binuclear Pd-(2-aminothiazole) (urea), Pd(atz,ur) complex was prepared and characterized for the assessment of the activity of alpha amylase enzyme in urine and serum samples for early diagnosis of Pancreatitis disease. The assessment of alpha amylase activity is carried out by the quenching of the luminescence intensity of the nano optical sensor binuclear Pd(atz,ur) complex at 457nm by the 2-chloro-4-nitrophenol (2-CNP) which produced from the reaction of the enzyme with 2-chloro-4-nitrophenyl-α-d-maltotrioside (CNPG3) substrate. The remarkable quenching of the luminescence intensity at 457nm of nano Pd(atz,ur) doped in sol-gel matrix by various concentrations of the 2-CNP was successfully used as an optical sensor for the assessment of α-amylase activity. The calibration plot was achieved over the concentration range 8.5×10(-6) to 1.9×10(-9)molL(-1) 2-CNP with a correlation coefficient of (0.999) and a detection limit of (7.4×10(-10)molL(-1)). The method was used satisfactorily for the assessment of the α-amylase activity over activity range (3-321U/L) in different urine and serum samples of pancreatitis patients. The assessment of the alpha amylase biomarker by the proposed method increases its sensitivity (96.88%) and specificity (94.41%) for early diagnosis of pancreatitis diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. A novel biphenolic ligand for selective Mg2+ and Zn2+ ions sensing followed by colorimetric, spectroscopic and cell imaging methods.

    PubMed

    Maheswari, Palanisamy Uma; Renuga, Duraisamy; Henry, Linda Jeeva Kumari; Ruckmani, Kandasamy

    2018-04-30

    The (E)-2-((2-hydrohy-5-methylphenylimino) methyl) phenol ligand was synthesized. The receptor was characterized by IR, 1 H and 13 C NMR and CHN analysis. The ligand exhibits colorimetric and fluorometric sensing of Zn 2+ and Mg 2+ ions in semi-aqueous medium (DMSO-H2O). The receptor was tested with series of transition metal ions (Cr 2+ , Fe 2+ , Ni 2+ , Co 2+ , Cu 2+ , Zn 2+ ) and heavy metal ions (Sn 2+ , Pd 2+ , Ce 2+ , Hg 2+ , Cd 2+ ) and the essential human body elements like Ca 2+ , Mg 2+ , Na + and K + ions. The naked eye colorimetric sensing was absorbed only for Zn 2+ and Mg 2+ . Both ions (ZnCl 2 and MgCl 2 in H 2 O), when added to the colorless solutions of the receptor of about 1 equivalence in incremental additions turn the solution into bright turmeric yellow. All other ions remain inactive, in colorimetric sensing. Further the Zn 2+ and Mg 2+ ions were probed by absorption and emission spectroscopy through incremental addition of respective metal ions. The in-situ deprotonation of the ligand on both Mg 2+ and Zn 2+ ions binding was confirmed by 1 H NMR titration studies. The imino nitrogen of the receptor is not coordinated to the metal ions. The Job's plot studies reveal the 1:2 binding ratio of metal ions to the receptor. The high fold fluorescence output on metal ions binding was positively used to sense the Zn 2+ and Mg 2+ ions, separately and together in HeLa cancer cells through cell imaging. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Study of the mechanism of the relaxant action of (+)-glaucine in rat vas deferens.

    PubMed Central

    Orallo, F.; Fernández Alzueta, A.; Loza, M. I.; Vivas, N.; Badía, A.; Campos, M.; Honrubia, M. A.; Cadavid, M. I.

    1993-01-01

    1. Effects of the aporphinoid alkaloid, (+)-glaucine, on rat vas deferens were investigated. 2. (+)-Glaucine (2-18 microM) competitively inhibited contractions induced by noradrenaline and methoxamine with a pA2 value of about 6. 3. (+)-Glaucine (2 and 18 microM) did not change the accumulation of tritium during incubation of the vas deferens with [3H]-noradrenaline. 4. (+)-Glaucine (0.3 nM-0.1 mM) inhibited specific [3H]-prazosin binding to membranes from rat vas deferens with a pKi value of 6.63, which is close to the pA2 value obtained against noradrenaline and methoxamine in functional studies. 5. In electrically-stimulated rat vas deferens, (+)-glaucine (0.3-10 microM) enhanced twitch contractions and competitively antagonized the inhibitory effect of clonidine with a pA2 value of 5.91. 6. In tissues incubated in depolarizing calcium-free high-potassium medium, (+)-glaucine (30-80 microM) inhibited Ca(2+)-induced contractions with depression of the maximal response at higher doses and with a pD'2 value of 3.65. Furthermore, (+)-glaucine (50 microM) did not modify basal 45Ca uptake but strongly inhibited the influx of 45Ca induced by K+. 7. These results suggest that (+)-glaucine has non-selective alpha 1- and alpha 2-adrenoceptor blocking properties. At higher doses, (+)-glaucine shows calcium antagonist activity which may be responsible, at least in part, for the inhibition of the contractions induced by Ca2+ in calcium-free high-potassium medium. PMID:8298818

  8. Effects of protopine on intracellular calcium and the PKC activity of rat aorta smooth muscle.

    PubMed

    Li, Bin; Wu, Qin; Shi, Jing-Shan; Sun, An-Sheng; Huang, Xie-Nan

    2005-04-25

    We have previously shown that the vasodilator effect of protopine (Pro) on rabbit aorta is related to the elevations of cAMP and cGMP. In the present study, the vasodilator mechanisms of Pro were further explored by recording the isotonic contraction of the rat aortic strips, detecting directly the intracellular free Ca(2+) concentration ([Ca(2+)](i)) with Fura-2/AM loaded vascular smooth muscle cells (VSMCs) of rat aorta, and determining the activity of protein kinase C (PKC) in rat aortic tissue with radioactive isotope gamma-32P -ATP-catalyzing assay. By recording the aortic strips contraction induced by noradrenaline (NA) and high potassium (K(+)), Pro shifted nonparallelly the concentration-response curves of NA and high K(+) to right, in which the maximal response was depressed in the presence of Pro (30 and 100 micromol/L), and the values of pD'(2) were 3.70-/+0.25 and 3.97-/+0.15 for NA and high K(+), respectively. In the Fura-2/AM loaded VSMCs, Pro (50 and 100 micromol/L) could not produce any significant change on the resting [Ca(2+)](i), but significantly decreased the [Ca(2+)](i) elevated by NA and high K(+). Pro (30 and 100 micromol/L) had no significant effect on the activity of the cytosolic and membrane PKC in the aortic strips inpretreated by NA. However, in the aortic strips pretreated by NA, the activity of membrane PKC was significantly increased and the activity of cytosolic PKC tended to be decreased by Pro, while the activity of total PKC did not change. These results suggest that Pro seems to promote the translocation of PKC from the cytosol to the membrane in the presence of NA, its vasodilator effect may be the comprehensive result of its decreasing effect on the [Ca(2+)](i) and the increasing effect on cAMP and cGMP, as well as its influence on the PKC.

  9. In operando neutron diffraction study of LaNdMgNi9H13 as a metal hydride battery anode

    NASA Astrophysics Data System (ADS)

    Nazer, N. S.; Denys, R. V.; Yartys, V. A.; Hu, Wei-Kang; Latroche, M.; Cuevas, F.; Hauback, B. C.; Henry, P. F.; Arnberg, L.

    2017-03-01

    La2MgNi9-related alloys are superior metal hydride battery anodes as compared to the commercial AB5 alloys. Nd-substituted La2-yNdyMgNi9 intermetallics are of particular interest because of increased diffusion rate of hydrogen and thus improved performance at high discharge currents. The present work presents in operando characterization of the LaNdMgNi9 intermetallic as anode for the nickel metal hydride (Ni-MH) battery. We have studied the structural evolution of LaNdMgNi9 during its charge and discharge using in situ neutron powder diffraction. The work included experiments using deuterium gas and electrochemical charge-discharge measurements. The alloy exhibited a high electrochemical discharge capacity (373 mAh/g) which is 20% higher than the AB5 type alloys. A saturated β-deuteride synthesized by solid-gas reaction at PD2 = 1.6 MPa contained 12.9 deuterium atoms per formula unit (D/f.u.) which resulted in a volume expansion of 26.1%. During the electrochemical charging, the volume expansion (23.4%) and D-contents were found to be slightly reduced. The reversible electrochemical cycling is performed through the formation of a two-phase mixture of the α-solid solution and β-hydride phases. Nd substitution contributes to the high-rate dischargeability, while maintaining a good cyclic stability. Electrochemical Impedance Spectroscopy (EIS) was used to characterize the anode electrode on cycling. A mathematical model for the impedance response of a porous electrode was utilized. The EIS showed a decreased hydrogen transport rate during the long-term cycling, which indicated a corresponding slowing down of the electrochemical processes at the surface of the metal hydride anode.

  10. Small fiber neuropathy in Parkinson's disease: A clinical, pathological and corneal confocal microscopy study.

    PubMed

    Kass-Iliyya, Lewis; Javed, Saad; Gosal, David; Kobylecki, Christopher; Marshall, Andrew; Petropoulos, Ioannis N; Ponirakis, Georgios; Tavakoli, Mitra; Ferdousi, Maryam; Chaudhuri, Kallol Ray; Jeziorska, Maria; Malik, Rayaz A; Silverdale, Monty A

    2015-12-01

    Autonomic and somatic denervation is well established in Parkinson's disease (PD). (1) To determine whether corneal confocal microscopy (CCM) can non-invasively demonstrate small nerve fiber damage in PD. (2) To identify relationships between corneal nerve parameters, intraepidermal nerve fiber density (IENFD) and clinical features of PD. Twenty-six PD patients and 26 controls underwent CCM of both eyes. 24/26 PD patients and 10/26 controls underwent skin biopsies from the dorsa of both feet. PD patients underwent assessment of parasympathetic function [deep breathing heart rate variability (DB-HRV)], autonomic symptoms [scale for outcomes in Parkinson's disease - autonomic symptoms (SCOPA-AUT)], motor symptoms [UPDRS-III "ON"] and cumulative Levodopa dose. PD patients had significantly reduced corneal nerve fiber density (CNFD) with increased corneal nerve branch density (CNBD) and corneal nerve fiber length (CNFL) compared to controls. CNBD and CNFL but not CNFD correlated inversely with UPDRS-III and SCOPA-AUT. All CCM parameters correlated strongly with DB-HRV. There was no correlation between CCM parameters and disease duration, cumulative Levodopa dose or pain. IENFD was significantly reduced in PD compared to controls and correlated with CNFD and UPDRS-III. However, unlike CCM measures, IENFD correlated with disease duration and cumulative Levodopa dose but not with autonomic dysfunction. CCM identifies corneal nerve fiber pathology, which correlates with autonomic symptoms, parasympathetic deficits and motor scores in patients with PD. IENFD is also reduced and correlates with CNFD and motor symptoms but not parasympathetic deficits, indicating it detects different aspects of peripheral nerve pathology in PD. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Characterization and autoradiographic localization of neurotensin binding sites in human sigmoid colon.

    PubMed

    Azriel, Y; Burcher, E

    2001-06-01

    Radioiodinated neurotensin ((125)I-NT) was used to characterize and localize NT binding sites in normal human sigmoid colon. Specimens were obtained from patients (30-77 years old) undergoing resection for colon carcinoma. Specific binding of (125)I-NT to sigmoid circular muscle membranes was enhanced by o-phenanthroline (1 mM) but other peptidase inhibitors were ineffective. (125)I-NT bound to a high-affinity site of K(d) = 0.88 +/- 0.09 nM and B(max) = 4.03 +/- 0.66 fmol/mg of wet weight tissue (n = 14), although in the majority of patients another site, of low but variable affinity, could also be detected. Specific binding of 50 pM (125)I-NT was inhibited by NT(8-13) > NT > SR142948A > or = neuromedin N > or = SR48692, consistent with binding to the NT1 receptor. In autoradiographic studies, dense specific binding of (125)I-NT was seen over myenteric and submucosal ganglia, moderate binding over circular muscle, and sparse binding over longitudinal muscle and taenia coli. Levocabastine, which has affinity for the NT2 receptor, did not inhibit specific binding of (125)I-NT in membrane competition or autoradiographic studies. NT contracted sigmoid colon circular muscle strips with a pD(2) value of 6.8 +/- 0.2 nM (n = 25). The contractile responses to NT were significantly potentiated in the presence of tetrodotoxin (1 microM), indicating a neural component. Results from functional studies support actions for NT on both muscle and enteric neurons, consistent with the presence of NT receptors on circular muscle and ganglia of human sigmoid colon. The lack of inhibition by levocabastine suggests that the second binding site detected does not correspond to the NT2 receptor.

  12. Periodontal disease and diabetes mellitus

    PubMed Central

    NEGRATO, Carlos Antonio; TARZIA, Olinda; JOVANOVIČ, Lois; CHINELLATO, Luiz Eduardo Montenegro

    2013-01-01

    Periodontal disease (PD) is one of the most commonly known human chronic disorders. The relationship between PD and several systemic diseases such as diabetes mellitus (DM) has been increasingly recognized over the past decades. Objective: The purpose of this review is to provide the reader with knowledge concerning the relationship between PD and DM. Many articles have been published in the english and Portuguese literature over the last 50 years examining the relationship between these two chronic diseases. Data interpretation is often confounded by varying definitions of DM, PD and different clinical criteria were applied to determine the prevalence, extent and severity of PD, levels of glycemic control and diabetes-related complications. Methods: This paper provides a broad overview of the predominant findings from research conducted using the BBO (Bibliografia Brasileira de Odontologia), MEDLINE, LILACS and PubMed for Controlled Trials databases, in english and Portuguese languages published from 1960 to October 2012. Primary research reports on investigations of relationships between DM/DM control, PD/periodontal treatment and PD/DM/diabetes-related complications identified relevant papers and meta-analyses published in this period. Results: This paper describes the relationship between PD and DM and answers the following questions: 1- The effect of DM on PD, 2- The effects of glycemic control on PD and 3- The effects of PD on glycemic control and on diabetes-related complications. Conclusions: The scientific evidence reviewed supports diabetes having an adverse effect on periodontal health and PD having an adverse effect on glycemic control and on diabetes-related complications. Further research is needed to clarify these relationships and larger, prospective, controlled trials with ethnically diverse populations are warranted to establish that treating PD can positively influence glycemic control and possibly reduce the burden of diabetes

  13. Rethinking energy in parkinsonian motor symptoms: a potential role for neural metabolic deficits

    PubMed Central

    Amano, Shinichi; Kegelmeyer, Deborah; Hong, S. Lee

    2015-01-01

    Parkinson’s disease (PD) is characterized as a chronic and progressive neurodegenerative disorder that results in a variety of debilitating symptoms, including bradykinesia, resting tremor, rigidity, and postural instability. Research spanning several decades has emphasized basal ganglia dysfunction, predominantly resulting from dopaminergic (DA) cell loss, as the primarily cause of the aforementioned parkinsonian features. But, why those particular features manifest themselves remains an enigma. The goal of this paper is to develop a theoretical framework that parkinsonian motor features are behavioral consequence of a long-term adaptation to their inability (inflexibility or lack of capacity) to meet energetic demands, due to neural metabolic deficits arising from mitochondrial dysfunction associated with PD. Here, we discuss neurophysiological changes that are generally associated with PD, such as selective degeneration of DA neurons in the substantia nigra pars compacta (SNc), in conjunction with metabolic and mitochondrial dysfunction. We then characterize the cardinal motor symptoms of PD, bradykinesia, resting tremor, rigidity and gait disturbance, reviewing literature to demonstrate how these motor patterns are actually energy efficient from a metabolic perspective. We will also develop three testable hypotheses: (1) neural metabolic deficits precede the increased rate of neurodegeneration and onset of behavioral symptoms in PD; (2) motor behavior of persons with PD are more sensitive to changes in metabolic/bioenergetic state; and (3) improvement of metabolic function could lead to better motor performance in persons with PD. These hypotheses are designed to introduce a novel viewpoint that can elucidate the connections between metabolic, neural and motor function in PD. PMID:25610377

  14. Early Corneal Innervation and Trigeminal Alterations in Parkinson Disease: A Pilot Study.

    PubMed

    Arrigo, Alessandro; Rania, Laura; Calamuneri, Alessandro; Postorino, Elisa Imelde; Mormina, Enricomaria; Gaeta, Michele; Marino, Silvia; Di Lorenzo, Giuseppe; Quartarone, Angelo; Anastasi, Giuseppe; Puzzolo, Domenico; Aragona, Pasquale

    2018-04-01

    To describe corneal innervation and trigeminal alterations in drug-naive patients with Parkinson disease (PD). A case series study was conducted by recruiting 3 early drug-naive patients with PD, 2 men and 1 woman (age: 72, 68, and 66, respectively). Ophthalmologic assessment included Ocular Surface Disease Index questionnaire, visual acuity by the logarithm of the minimum angle of resolution score, pupillary light reflexes, extrinsic ocular movements, corneal sensitivity, and slit-lamp examination. Corneal innervation parameter changes were evaluated in vivo using the Confoscan 4 confocal microscope, and they were compared with a control data set. The Heidelberg Retina Tomograph 3 (HRT3) has been used to assess retinal alterations in our patients, if compared with normal range values provided by the HRT3. Moreover, 3T magnetic resonance imaging (MRI) analysis of water diffusion property changes of trigeminal nerves was performed. All data were analyzed and compared with 2 control data sets made by 14 age-matched controls. Patients with PD showed profound alterations of corneal innervation and of trigeminal diffusion MRI parameters, compared with controls. Strong differences (PD vs. controls) were found for deep nerve tortuosity (Kallinikos mean 19.94 vs. 2.13) and the number of beadings (mean 34.2 vs. 15.5). HRT3 retinal evaluation revealed less structural changes compared with the normal range. Diffusion MRI showed profound changes of white matter diffusion properties (PD vs. controls), with fractional anisotropy decrement (mean 0.3029 vs. 0.3329) and mean diffusivity increment (mean 0.00127 vs. 0.00106). Corneal innervation changes might occur earlier in patients with PD than in retinal ones. Confocal corneal innervation analysis might provide possible early biomarkers for a better PD evaluation and for its earlier diagnosis.

  15. Tachykinin receptors in rabbit airways--characterization by functional, autoradiographic and binding studies.

    PubMed Central

    Black, J. L.; Diment, L. M.; Alouan, L. A.; Johnson, P. R.; Armour, C. L.; Badgery-Parker, T.; Burcher, E.

    1992-01-01

    1. In many species, both NK1 and NK2 tachykinin receptors appear to be important in mediating the contraction of airway smooth muscle. We have examined the distribution and characterization of receptors for tachykinins in rabbit airways using functional length tension studies, autoradiography and radioligand binding studies. 2. Contractile responses to tachykinins were elicited in four different areas of the respiratory tree--trachea, and three progressively more distal areas of the right bronchus. The NK2 receptor-preferring agonists, neurokinin A (NKA), neuropeptide gamma (NP gamma) and the NK2-selective [Lys5 MeLeu9, Nle10]-NKA(4-10) [NKA (4-10) analogue] produced similar contraction in all four areas. Substance P (SP) and the NK1-selective [Sar9,Met(O2)11]-SP (Sar-SP) exhibited a marked location-dependence in the magnitude of contraction, producing minimal contraction in the trachea and more proximal bronchi with contractions becoming progressively larger in the more distal airways. Senktide (which is selective for the NK3 receptor) produced negligible contraction in all areas. 3. The NK2-selective antagonist, MDL29,913, was a weak antagonist of NKA and NKA(4-10) analogue. At a concentration of 2 microM, it produced a small but significant shift in the response curve to NKA and a greater shift (8 fold) in the curve to NKA(4-10) analogue, but it had no effect on responses to Sar-SP. The non peptide NK1 receptor antagonist, CP-96,345, was also unexpectedly weak in this preparation. The pD2 value for Sar-SP was decreased 27 fold by CP-96,345 at a concentration of 1 microM, without alteration in the maximum response.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 4 PMID:1384914

  16. Receptors for substance P. II. Classification by agonist fragments and homologues.

    PubMed

    Regoli, D; Mizrahi, J; D'Orléans-Juste, P; Escher, E

    1984-01-27

    Substance P (SP), a series of C-terminal fragments, SP-(2-11), SP-(3-11), SP-(4-11), SP-(5-11), SP-(6-11), SP-(7-11) and the homologues physalaemin, eledoisin and kassinin were used to measure the order of potency of agonists in five pharmacological preparations. These are: the guinea pig ileum, the guinea pig trachea, the rabbit mesenteric vein, the dog common carotid artery and the rabbit aorta. Apparent affinities (pD2) and relative activities of SP-related peptides were measured in the absence and presence of antagonists (a mixture of atropine, indomethacin and diphenhydramine) in the guinea pig ileum and the rabbit mesenteric vein, in the absence and presence of indomethacin in the guinea pig trachea and in tissues with intact endothelium (the dog carotid artery and the rabbit aorta). The orders of potency measured in the absence and presence of antagonists in the guinea pig ileum were different, while no major changes were noted in two other preparations, namely the guinea pig trachea and the rabbit mesenteric vein. The order of potency of agonists determined with homologues revealed the existence of three major patterns namely: kassinin greater than eledoisin greater than physalaemin = SP in the guinea pig trachea and the rabbit mesenteric vein, SP = physalaemin greater than eledoisin greater than kassinin in the arterial smooth muscle of the dog carotid artery and the rabbit aorta and physalaemin greater than kassinin greater than eledoisin greater than SP in the guinea pig ileum treated with antagonists.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Smooth muscle neurokinin-2 receptors mediate contraction in human saphenous veins.

    PubMed

    Mechiche, Hakima; Grassin-Delyle, Stanislas; Pinto, Francisco M; Buenestado, Amparo; Candenas, Luz; Devillier, Philippe

    2011-05-01

    Substance P (SP) and neurokinin A (NKA) are members of the tachykinin peptides family. SP causes endothelial-dependant relaxation but the contractile response to tachykinins in human vessels remains unknown. The objective was to assess the expression and the contractile effects of tachykinins and their receptors in human saphenous veins (SV). Tachykinin expression was assessed with RT-PCR, tachykinin receptors expression with RT-PCR and immunohistochemistry, and functional studies were performed in organ bath. Transcripts of all tachykinin and tachykinin receptor genes were found in SV. NK(1)-receptors were localized in both endothelial and smooth muscle layers of undistended SV, whereas they were only found in smooth muscle layers of varicose SV. The expression of NK(2)- and NK(3)-receptors was limited to the smooth muscle in both preparations. NKA induced concentration-dependent contractions in about half the varicose SV. Maximum effect reached 27.6±5.5% of 90 mM KCl and the pD(2) value was 7.3±0.2. NKA also induced the contraction of undistended veins from bypass and did not cause the relaxation of these vessels after precontraction. The NK(2)-receptor antagonist SR48968 abolished the contraction induced by NKA, and a rapid desensitization of the NK(2)-receptor was observed. In varicose SV, the agonists specific to NK(1)- or NK(3)-receptors did not cause either contraction or relaxation. The stimulation of smooth muscle NK(2)-receptors can induce the contraction of human SV. As SV is richly innervated, tachykinins may participate in the regulation of the tone in this portion of the low pressure vascular system. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Porous nanocrystalline silicon supported bimetallic Pd-Au catalysts: preparation, characterization and direct hydrogen peroxide synthesis

    NASA Astrophysics Data System (ADS)

    Potemkin, Dmitriy I.; Maslov, Dmitry K.; Loponov, Konstantin; Snytnikov, Pavel V.; Shubin, Yuri V.; Plyusnin, Pavel E.; Svintsitskiy, Dmitry A.; Sobyanin, Vladimir A.; Lapkin, Alexei A.

    2018-03-01

    Bimetallic Pd-Au catalysts were prepared on the porous nanocrystalline silicon (PSi) for the first time. The catalysts were tested in the reaction of direct hydrogen peroxide synthesis and characterised by standard structural and chemical techniques. It was shown that the Pd-Au/PSi catalyst prepared from conventional H2[PdCl4] and H[AuCl4] precursors contains monometallic Pd and a range of different Pd-Au alloy nanoparticles over the oxidized PSi surface. The PdAu2/PSi catalyst prepared from the [Pd(NH3)4][AuCl4]2 double complex salt single-source precursor predominantly contains bimetallic Pd-Au alloy nanoparticles. For both catalysts the surface of bimetallic nanoparticles is Pd-enriched and contains palladium in Pd0 and Pd2+ states. Among the catalysts studied, the PdAu2/PSi catalyst was the most active and selective in the direct H2O2 synthesis with H2O2 productivity of 0.5 at selectivity of 50 % and H2O2 concentration of 0.023 M in 0.03 M H2SO4-methanol solution after 5 h on stream at -10 °C and atmospheric pressure. This performance is due to high activity in the H2O2 synthesis reaction and low activities in the undesirable H2O2 decomposition and hydrogenation reactions. Good performance of the PdAu2/PSi catalyst was associated with the major part of Pd in the catalyst being in the form of the bimetallic Pd-Au nanoparticles. Porous silicon was concluded to be a promising catalytic support for direct hydrogen peroxide synthesis due to its inertness with respect to undesirable side reactions, high thermal stability and conductivity, possibility of safe operation at high temperatures and pressures and a well-established manufacturing process.

  19. Grafting the surface of carbon nanotubes and carbon black with the chemical properties of hyperbranched polyamines

    NASA Astrophysics Data System (ADS)

    Morales-Lara, Francisco; Domingo-García, María; López-Garzón, Rafael; Luz Godino-Salido, María; Peñas-Sanjuán, Antonio; López-Garzón, F. Javier; Pérez-Mendoza, Manuel; Melguizo, Manuel

    2016-01-01

    Controlling the chemistry on the surface of new carbon materials is a key factor to widen the range of their applicability. In this paper we show a grafting methodology of polyalkylamines to the surface of carbon nanomaterials, in particular, carbon nanotubes and a carbon black. The aim of this work is to reach large degrees of covalent functionalization with hyperbranched polyethyleneimines (HBPEIs) and to efficiently preserve the strong chelating properties of the HBPEIs when they are fixed to the surface of these carbon materials. This functionalization opens new possibilities of using these carbon nanotubes-based hybrids. The results show that the HBPEIs are covalently attached to the carbon materials, forming hybrids. These hybrids emerge from the reaction of amine functions of the HBPEIs with carbonyls and carboxylic anhydrides of the carbon surface which become imine and imide bonds. Thus, due to the nature of these bonds, the pre-oxidized samples with relevant number of C=O groups showed an increase in the degree of functionalization with the HBPEIs. Furthermore, both the acid-base properties and the coordination capacity for metal ions of the hybrids are equivalent to that of the free HBPEIs in solution. This means that the chemical characteristics of the HBPEIs have been efficiently transferred to the hybrids. To reach this conclusion we have developed a novel procedure to assess the acid-base and the coordination properties of the hybrids (solids) by means of potentiometric titration. The good agreement of the values obtained for the hybrids and for the free HBPEIs in aqueous solution supports the reliability of the procedure. Moreover, the high capacity of the hybrids to capture Ni2+ by complexation opens new possibilities of using these hybrids to capture high-value metal ions such as Pd2+ and Pt2+.

  20. Grafting the surface of carbon nanotubes and carbon black with the chemical properties of hyperbranched polyamines

    PubMed Central

    Morales-Lara, Francisco; Domingo-García, María; López-Garzón, Rafael; Luz Godino-Salido, María; Peñas-Sanjuán, Antonio; López-Garzón, F. Javier; Pérez-Mendoza, Manuel; Melguizo, Manuel

    2016-01-01

    Abstract Controlling the chemistry on the surface of new carbon materials is a key factor to widen the range of their applicability. In this paper we show a grafting methodology of polyalkylamines to the surface of carbon nanomaterials, in particular, carbon nanotubes and a carbon black. The aim of this work is to reach large degrees of covalent functionalization with hyperbranched polyethyleneimines (HBPEIs) and to efficiently preserve the strong chelating properties of the HBPEIs when they are fixed to the surface of these carbon materials. This functionalization opens new possibilities of using these carbon nanotubes-based hybrids. The results show that the HBPEIs are covalently attached to the carbon materials, forming hybrids. These hybrids emerge from the reaction of amine functions of the HBPEIs with carbonyls and carboxylic anhydrides of the carbon surface which become imine and imide bonds. Thus, due to the nature of these bonds, the pre-oxidized samples with relevant number of C=O groups showed an increase in the degree of functionalization with the HBPEIs. Furthermore, both the acid-base properties and the coordination capacity for metal ions of the hybrids are equivalent to that of the free HBPEIs in solution. This means that the chemical characteristics of the HBPEIs have been efficiently transferred to the hybrids. To reach this conclusion we have developed a novel procedure to assess the acid-base and the coordination properties of the hybrids (solids) by means of potentiometric titration. The good agreement of the values obtained for the hybrids and for the free HBPEIs in aqueous solution supports the reliability of the procedure. Moreover, the high capacity of the hybrids to capture Ni2+ by complexation opens new possibilities of using these hybrids to capture high-value metal ions such as Pd2+ and Pt2+. PMID:27877902

  1. Microsoft Kinect can distinguish differences in over-ground gait between older persons with and without Parkinson's disease.

    PubMed

    Eltoukhy, Moataz; Kuenze, Christopher; Oh, Jeonghoon; Jacopetti, Marco; Wooten, Savannah; Signorile, Joseph

    2017-06-01

    Gait patterns differ between healthy elders and those with Parkinson's disease (PD). A simple, low-cost clinical tool that can evaluate kinematic differences between these populations would be invaluable diagnostically; since gait analysis in a clinical setting is impractical due to cost and technical expertise. This study investigated the between group differences between the Kinect and a 3D movement analysis system (BTS) and reported validity and reliability of the Kinect v2 sensor for gait analysis. Nineteen subjects participated, eleven without (C) and eight with PD (PD). Outcome measures included spatiotemporal parameters and kinematics. Ankle range of motion for C was significantly less during ankle swing compared to PD (p=0.04) for the Kinect. Both systems showed significant differences for stride length (BTS (C 1.24±0.16, PD=1.01±0.17, p=0.009), Kinect (C=1.24±0.17, PD=1.00±0.18, p=0.009)), gait velocity (BTS (C=1.06±0.14, PD=0.83±0.15, p=0.01), Kinect (C=1.06±0.15, PD=0.83±0.16, p=0.01)), and swing velocity (BTS (C=2.50±0.27, PD=2.12±0.36, p=0.02), Kinect (C=2.32±0.25, PD=1.95±0.31, p=0.01)) between groups. Agreement (Range ICC =0.93-0.99) and consistency (Range ICC =0.94-0.99) were excellent between systems for stride length, stance duration, swing duration, gait velocity, and swing velocity. The Kinect v2 can was sensitive enough to detect between group differences and consistently produced results similar to the BTS system. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  2. Fate of phenanthrene, pyrene and benzo[a]pyrene during biodegradation of crude oil added to two soils.

    PubMed

    Smith, M J; Lethbridge, G; Burns, R G

    1999-04-15

    The release of 14CO2 from 9-[14C]phenanthrene, 4,5,9,10-[14C]pyrene and 7-[14C]benzo[a]pyrene, added to Brent/Fortes crude oil and mixed into a pristine sand soil (0.40% organic C) and a pristine organic soil (22.9% organic C), was determined. After 244 days at 25 degrees C, 11.1 +/- 3.5% (sand) and 17.1 +/- 0.30% (organic) phenanthrene-14C and 9.77 +/- 2.8% (sand) and 5.86 +/- 1.4% (organic) benzo[a]pyrene-14C was released. After 210 days, 3.65 +/- 0.5% (sand) and 4.43 +/- 0.33% (organic) pyrene-14C was released. Inoculation of these two soils with DC1 and PD2 (bacteria capable of accelerating the phenanthrene and pyrene mineralisation in soil in the absence of crude oil) either at day 0 or after release as 14CO2 by indigenous degraders had ceased, failed to increase or initiate further mineralisation. Thus, aged PAH residues were non-bioavailable to these metabolically competent degrading microorganisms. At the end of the first period of incubation (210 days or 244 days), the total aromatic hydrocarbons recovered using Soxhlet extraction was 0.18% (sand) and 42.8% (organic) compared with approximately 100% from bio-inhibited soils. This confirmed that the indigenous microbiological activity not only caused a limited amount of PAH mineralisation but also reduced the extractability of residues, possibly due to the generation of metabolites which were chemisorbed and bound (and non extractable) in 'aged' soils.

  3. The Effects of Diode Laser Therapy as an Adjunct to Scaling and Root Planing in the Treatment of Aggressive Periodontitis: A 1-Year Randomized Controlled Clinical Trial.

    PubMed

    Matarese, Giovanni; Ramaglia, Luca; Cicciù, Marco; Cordasco, Giancarlo; Isola, Gaetano

    2017-12-01

    The aim of this study was to investigate and compare the clinical, microbial, and inflammatory effects of a diode laser as an adjunct to scaling and root planing (SRP) versus SRP alone for the treatment of generalized aggressive periodontitis (GAgP). Using a split-mouth design, 31 patients with GAgP were enrolled in the study. The maxillary right and left quadrants were randomly assigned to SRP+diode laser or SRP alone. Patients were examined on a regular basis for clinical, microbiological, and inflammatory mediator changes over a 1-year period. Clinical attachment level (CAL) was the primary outcome variable chosen. In addition, subgingival biofilm samples and gingival crevicular fluid (GCF) inflammatory mediators were analyzed at each follow-up session. Compared to baseline, both treatments demonstrated an improvement in periodontal parameters at 1 year. However, SRP+diode laser produced a significant improvement in probing depth (PD; 2.56 ± 0.44 vs. 3.36 ± 0.51 mm, p < 0.05) and CAL (3.47 ± 0.25 vs. 4.11 ± 0.26 mm, p < 0.05) values compared to SRP alone. Similarly, in the SRP+diode laser group, the bacteria of orange complex group were significantly reduced at 30 and 60 days compared to SRP alone. Moreover, SRP+diode laser determined a reduction in mean GCF level of interleukin (IL)-1β and IL-1β/IL-10 ratio at 15 and 30 days compared to SRP alone (p < 0.05). At 1 year, SRP+diode laser yielded a significant reduction in some clinical parameters, while microbial and inflammatory mediator changes were not significantly reduced compared to SRP alone.

  4. Marinesco bodies and substantia nigra neuron density in Parkinson's disease.

    PubMed

    Abbott, R D; Nelson, J S; Ross, G W; Uyehara-Lock, J H; Tanner, C M; Masaki, K H; Launer, L J; White, L R; Petrovitch, H

    2017-12-01

    Marinesco bodies (MB) are intranuclear inclusions in pigmented neurons of the substantia nigra (SN). While rare in children, frequency increases with normal ageing and is high in Alzheimer's disease, dementia with Lewy bodies and other neurodegenerative disorders. Coinciding with the age-related rise in MB frequency is initiation of cell death among SN neurons. Whether MB have a role in this process is unknown. Our aim is to examine the association of MB with SN neuron density in Parkinson's disease (PD) in the Honolulu-Asia Aging Study. Data on MB and neuron density were measured in SN transverse sections in 131 autopsied men aged 73-99 years at the time of death from 1992 to 2007. Marinesco body frequency was low in the presence vs. absence of PD (2.3% vs. 6.6%, P < 0.001). After PD onset, MB frequency declined as duration of PD increased (P = 0.006). Similar patterns were observed for SN neuron density. When MB frequency was low, neuron density was noticeably reduced in the SN ventrolateral quadrant, the region most vulnerable to PD neurodegeneration. Low MB frequency was unique to PD as its high frequency in non-PD cases was unrelated to parkinsonian signs and incidental Lewy bodies. Frequency was high in the presence of Alzheimer's disease and apolipoprotein ε4 alleles. While findings confirm that MB frequency is low in PD, declines in MB frequency continue with PD duration. The extent to which MB have a distinct relationship with PD warrants clarification. Further studies of MB could be important in understanding PD processes. © 2017 British Neuropathological Society.

  5. New Complexity-Building Reactions of Alpha-Keto Esters

    NASA Astrophysics Data System (ADS)

    Bartlett, Samuel L.

    I. Introduction: Importance of Asymmetric Catalysis and the Reactivity Patterns of alpha-Keto Esters. II. Synthesis of Complex Tertiary Glycolates by Enantioconvergent Arylation of Stereochemically Labile alpha-Keto Esters. Enantioconvergent arylation reactions of boronic acids and racemic ?-stereogenic alpha-keto esters have been developed. The reactions are catalyzed by a chiral (diene)Rh(I) complex and provide a wide array of beta-stereogenic tertiary aryl glycolate derivatives with high levels of diastereo- and enantioselectivity. Racemization studies employing a series of sterically differentiated tertiary amines suggest that the steric nature of the amine base additive exerts a significant influence on the rate of substrate racemization. III. Palladium-Catalyzed beta-Arylation of alpha-Keto Esters . A catalyst system derived from commercially available Pd2(dba) 3 and PtBu3 has been applied to the coupling of alpha-keto ester enolates and aryl bromides. The reaction provides access to an array of beta-stereogenic alpha-keto ester derivatives. When the air stable ligand precursor PtBu 3˙HBF4 is employed, the reaction can be carried out without use of a glovebox. The derived products are of broad interest given the prevalence of the alpha-keto acid substructure in biologically important molecules. IV. Catalytic Enantioselective [3+2] Cycloaddition of alpha-Keto Ester Enolates and Nitrile Oxides. An enantioselective [3+2] cycloaddition reaction between nitrile oxides and transiently generated enolates of alpha-keto esters has been developed. The catalyst system was found to be compatible with in situ nitrile oxide generation conditions. A versatile array of nitrile oxides and alpha-keto esters could participate in the cycloaddition, providing novel 5-hydroxy-2-isoxazolines in high chemical yield with high levels of diastereo- and enantioselectivity. Notably, the optimal reaction conditions circumvented concurrent reaction via O-imidoylation and hetero-[3

  6. Exercise sensitizes skeletal muscle to extracellular ATP for IL-6 expression in mice.

    PubMed

    Fernández-Verdejo, R; Casas, M; Galgani, J E; Jaimovich, E; Buvinic, S

    2014-04-01

    Active skeletal muscle synthesizes and releases interleukin-6 (IL-6), which plays important roles in the organism's adaptation to exercise. Autocrine/paracrine ATP signaling has been shown to modulate IL-6 expression. The aim of this study was to determine whether a period of physical activity modifies the ATP-induced IL-6 expression. BalbC mice were either subject to 5 weeks voluntary wheel running (VA) or kept sedentary (SED). Flexor digitorum brevis muscles were dissected, stimulated with different ATP concentrations (0-100 μM) and IL-6 mRNA levels were measured using qPCR. ATP evoked a concentration-dependent rise in IL-6 mRNA in both SED and VA mice. VA mice however, had significantly higher ATP sensitivity (pD2 pharmacological values: VA=5.58±0.02 vs. SED=4.95±0.04, p<0.05). Interestingly, in VA mice we observed a positive correlation between the level of physical activity and the IL-6 mRNA increase following fiber stimulation with 10 μM ATP. In addition, there were lower P2Y2- and higher P2Y14-receptor mRNA levels in skeletal muscles of VA compared to SED mice, showing plasticity of nucleotide receptors with exercise. These results suggest that exercise increases skeletal muscle ATP sensitivity, a response dependent on the level of physical activity performed. This could have an important role in the mechanisms controlling skeletal muscle adaptation to exercise and training. © Georg Thieme Verlag KG Stuttgart · New York.

  7. Pharmacological characterization of BR-A-657, a highly potent nonpeptide angiotensin II receptor antagonist.

    PubMed

    Chi, Yong Ha; Lee, Joo Han; Kim, Je Hak; Tan, Hyun Kwang; Kim, Sang Lin; Lee, Jae Yeol; Rim, Hong-Kun; Paik, Soo Heui; Lee, Kyung-Tae

    2013-01-01

    The pharmacological profile of BR-A-657, 2-n-butyl-5-dimethylamino-thiocarbonyl-methyl-6-methyl-3-{[2-(1H-tetrazole-5-yl)biphenyl-4-yl]methyl}-pyrimidin-4(3H)-one, a new nonpeptide AT1-selective angiotensin receptor antagonist, has been investigated in a variety of in vitro and in vivo experimental models. In the present study, BR-A-657 displaced [(125)I][Sar(1)-Ile(8)]angiotensin II (Ang II) from its specific binding sites to AT1 subtype receptors in membrane fractions of HEK-293 cells with an IC50 of 0.16 nM. In a functional assay using isolated rabbit thoracic aorta, BR-A-657 inhibited the contractile response to Ang II (pD'2: 9.15) with a significant reduction in the maximum. In conscious rats, BR-A-657 (0.01, 0.1, 1 mg/kg; intravenously (i.v.)) dose-dependently antagonized Ang II-induced pressor responses. In addition, BR-A-657 dose-dependently decreased mean arterial pressure in furosemide-treated rats and renal hypertensive rats. Moreover, BR-A-657 given orally at 1 and 3 mg/kg reduced blood pressure in conscious renal hypertensive rats. Taken together, these findings indicate that BR-A-657 is a potent and specific antagonist of Ang II at the AT1 receptor subtype, and reveal the molecular basis responsible for the marked lowering of blood pressure in conscious rats.

  8. Prolonged maternal separation attenuates BDNF-ERK signaling correlated with spine formation in the hippocampus during early brain development.

    PubMed

    Ohta, Ken-Ichi; Suzuki, Shingo; Warita, Katsuhiko; Kaji, Tomohiro; Kusaka, Takashi; Miki, Takanori

    2017-04-01

    Maternal separation (MS) is known to affect hippocampal function such as learning and memory, yet the molecular mechanism remains unknown. We hypothesized that these impairments are attributed to abnormities of neural circuit formation by MS, and focused on brain-derived neurotrophic factor (BDNF) as key factor because BDNF signaling has an essential role in synapse formation during early brain development. Using rat offspring exposed to MS for 6 h/day during postnatal days (PD) 2-20, we estimated BDNF signaling in the hippocampus during brain development. Our results show that MS attenuated BDNF expression and activation of extracellular signal-regulated kinase (ERK) around PD 7. Moreover, plasticity-related immediate early genes, which are transcriptionally regulated by BDNF-ERK signaling, were also reduced by MS around PD 7. Interestingly, detailed analysis revealed that MS particularly reduced expression of BDNF gene and immediate early genes in the cornu ammonis 1 (CA1) of hippocampus at PD 7. Considering that BDNF-ERK signaling is involved in spine formation, we next evaluated spine formation in the hippocampus during the weaning period. Our results show that MS particularly reduced mature spine density in proximal apical dendrites of CA1 pyramidal neurons at PD 21. These results suggest that MS could attenuate BDNF-ERK signaling during primary synaptogenesis with a region-specific manner, which is likely to lead to decreased spine formation and maturation observed in the hippocampal CA1 region. It is speculated that this incomplete spine formation during early brain development has an influence on learning capabilities throughout adulthood. © 2017 International Society for Neurochemistry.

  9. Potential complications when developing gene deletion clones in Xylella fastidiosa.

    PubMed

    Johnson, Kameka L; Cursino, Luciana; Athinuwat, Dusit; Burr, Thomas J; Mowery, Patricia

    2015-04-16

    The Gram-negative xylem-limited bacterium, Xylella fastidiosa, is an important plant pathogen that infects a number of high value crops. The Temecula 1 strain infects grapevines and induces Pierce's disease, which causes symptoms such as scorching on leaves, cluster collapse, and eventual plant death. In order to understand the pathogenesis of X. fastidiosa, researchers routinely perform gene deletion studies and select mutants via antibiotic markers. Site-directed pilJ mutant of X. fastidiosa were generated and selected on antibiotic media. Mutant cultures were assessed by PCR to determine if they were composed of purely transformant cells or included mixtures of non-transformants cells. Then pure pilJ mutant and wildtype cells were mixed in PD2 medium and following incubation and exposure to kanamycin were assessed by PCR for presence of mutant and wildtype populations. We have discovered that when creating clones of targeted mutants of X. fastidiosa Temecula 1 with selection on antibiotic plates, X. fastidiosa lacking the gene deletion often persist in association with targeted mutant cells. We believe this phenomenon is due to spontaneous antibiotic resistance and/or X. fastidiosa characteristically forming aggregates that can be comprised of transformed and non-transformed cells. A combined population was confirmed by PCR, which showed that targeted mutant clones were mixed with non-transformed cells. After repeated transfer and storage the non-transformed cells became the dominant clone present. We have discovered that special precautions are warranted when developing a targeted gene mutation in X. fastidiosa because colonies that arise following transformation and selection are often comprised of transformed and non-transformed cells. Following transfer and storage the cells can consist primarily of the non-transformed strain. As a result, careful monitoring of targeted mutant strains must be performed to avoid mixed populations and confounding results.

  10. Multiple Condensation Reactions Involving Pt(II) /Pd(II) -OH2 , Pt-NH3 , and Cytosine-NH2 Groups: New Twists in Cisplatin-Nucleobase Chemistry.

    PubMed

    Yin-Bandur, Lu; Sanz Miguel, Pablo J; Rodríguez-Santiago, Luis; Sodupe, Mariona; Berghaus, Melanie; Lippert, Bernhard

    2016-09-12

    The coordination chemistry of the antitumor agent cisplatin and related complexes with DNA and its constituents, that is, the nucleobases, appears to be dominated by 1:1 and 1:2 adducts of the types cis-[Pta2 (nucleobase)X] and cis-[Pta2 (nucleobase)2 ] (a=NH3 or amine; a2 =diamine or diimine; X=Cl, OH or OH2 ). Here, we have studied the interactions of the putative 1:1 adducts cis-[Pta2 (1-MeC-N3)(OH2 )](2+) (with a=NH3 , a2 =2,2'-bpy (2,2'-bipyridine), 1-MeC=model nucleobase 1-methylcytosine) with additional cis-[Pt(NH3 )2 (OH2 )2 ](2+) or its kinetically superior analogues [Pd(en)(OH2 )2 ](2+) (en=ethylenediamine) and [Pd(2,2'-bpy)(OH2 )2 ](2+) . Depending upon the conditions applied different compounds of different nuclearity are formed. Without exception they represent condensation products of the components, containing μ-1-MeC-H , μ-OH(-) , as well as μ-NH2 (-) bridges. In the presence of Ag(+) ions, the isolated products in several cases display additionally Pt→Ag dative bonds. On the basis of the cytosine-containing structures established by X-ray crystallography, it is proposed that any of the feasible initial 1:1 nucleobase adducts of cisplatin could form dinuclear Pt complexes upon reaction with additional hydrolyzed cisplatin, thereby generating nucleobase adducts other than the presently established ones. Two findings appear to be of particular significance: First, hydrolyzed cisplatin can have a moderately accelerating effect on the formation of a secondary nucleobase product. Second, NH3 ligands of the cisplatin moiety can be converted into bridging amido ligands following condensation with the diaqua species of cisplatin. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Chemotherapeutic response to cisplatin-like drugs in human breast cancer cells probed by vibrational microspectroscopy.

    PubMed

    Batista de Carvalho, A L M; Pilling, M; Gardner, P; Doherty, J; Cinque, G; Wehbe, K; Kelley, C; Batista de Carvalho, L A E; Marques, M P M

    2016-06-23

    Studies of drug-cell interactions in cancer model systems are essential in the preclinical stage of rational drug design, which relies on a thorough understanding of the mechanisms underlying cytotoxic activity and biological effects, at a molecular level. This study aimed at applying complementary vibrational spectroscopy methods to evaluate the cellular impact of two Pt(ii) and Pd(ii) dinuclear chelates with spermine (Pt2Spm and Pd2Spm), using cisplatin (cis-Pt(NH3)2Cl2) as a reference compound. Their effects on cellular metabolism were monitored in a human triple-negative metastatic breast cancer cell line (MDA-MB-231) by Raman and synchrotron-radiation infrared microspectroscopies, for different drug concentrations (2-8 μM) at 48 h exposure. Multivariate data analysis was applied (unsupervised PCA), unveiling drug- and concentration-dependent effects: apart from discrimination between control and drug-treated cells, a clear separation was obtained for the different agents studied - mononuclear vs. polynuclear, and Pt(ii) vs. Pd(ii). Spectral biomarkers of drug action were identified, as well as the cellular response to the chemotherapeutic insult. The main effect of the tested compounds was found to be on DNA, lipids and proteins, the Pd(ii) agent having a more significant impact on proteins while its Pt(ii) homologue affected the cellular lipid content at lower concentrations, which suggests the occurrence of distinct and unconventional pathways of cytotoxicity for these dinuclear polyamine complexes. Raman and FTIR microspectroscopies were confirmed as powerful non-invasive techniques to obtain unique spectral signatures of the biochemical impact and physiological reaction of cells to anticancer agents.

  12. Xenon in the treatment of panic disorder: an open label study.

    PubMed

    Dobrovolsky, Alexander; Ichim, Thomas E; Ma, Daqing; Kesari, Santosh; Bogin, Vladimir

    2017-06-13

    Current treatments of panic disorder (PD) are limited by adverse effects, poor efficacy, and need for chronic administration. The established safety profile of subanesthetic concentrations of xenon gas, which is known to act as a glutamate subtype NMDA receptor antagonist, coupled with preclinical studies demonstrating its effects in other anxiety related conditions, prompted us to evaluate its feasibility and efficacy in treatment of patients with PD. An open-label clinical trial of xenon-oxygen mixture was conducted in 81 patients with PD; group 1 consisting of patients only with PD (N = 42); and group 2 patients with PD and other comorbidities (N = 39). Based on the analysis of the results of a number of psychometric scales used in this study (SAS, HADS, CGI), several conclusions can be made: (1) xenon is a potentially effective modality in acute treatment of PD; (2) an anti-panic effect of xenon administration persists for at least 6 months after the completion of the active phase of treatment; (3) xenon inhalation is well tolerated, with the drop-out rates being much lower than that of conventional pharmacotherapy (5.8% vs. 15%); (4) the severity of depressive disorders that frequently accompany PD can be significantly reduced with the use of xenon; (5) xenon may be considered as an alternative to benzodiazepines in conjunction with cognitive-behavioral therapy as a safe modality in treatment of anxiety disorder. These data support the need for randomized double-blind clinical trials to further study xenon-based interventions. Trial registration This clinical trial was retrospectively registered on April 14th, 2017 as ISRCTN15184285 in the ISRCTN database.

  13. Metal-Chelate Immobilization of Lipase onto Polyethylenimine Coated MCM-41 for Apple Flavor Synthesis.

    PubMed

    Sadighi, Armin; Motevalizadeh, Seyed Farshad; Hosseini, Morteza; Ramazani, Ali; Gorgannezhad, Lena; Nadri, Hamid; Deiham, Behnaz; Ganjali, Mohammad Reza; Shafiee, Abbas; Faramarzi, Mohammad Ali; Khoobi, Mehdi

    2017-08-01

    An enzyme immobilized on a mesoporous silica nanoparticle can serve as a multiple catalyst for the synthesis of industrially useful chemicals. In this work, MCM-41 nanoparticles were coated with polyethylenimine (MCM-41@PEI) and further modified by chelation of divalent metal ions (M = Co 2+ , Cu 2+ , or Pd 2+ ) to produce metal-chelated silica nanoparticles (MCM-41@PEI-M). Thermomyces lanuginosa lipase (TLL) was immobilized onto MCM-41, MCM-41@PEI, and MCM-41@PEI-M by physical adsorption. Maximum immobilization yield and efficiency of 75 ± 3.5 and 65 ± 2.7% were obtained for MCM@PEI-Co, respectively. The highest biocatalytic activity at extremely acidic and basic pH (pH = 3 and 10) values were achieved for MCM-PEI-Co and MCM-PEI-Cu, respectively. Optimum enzymatic activity was observed for MCM-41@PEI-Co at 75 °C, while immobilized lipase on the Co-chelated support retained 70% of its initial activity after 14 days of storage at room temperature. Due to its efficient catalytic performance, MCM-41@PEI-Co was selected for the synthesis of ethyl valerate in the presence of valeric acid and ethanol. The enzymatic esterification yield for immobilized lipase onto MCM-41@PEI-Co was 60 and 53%, respectively, after 24 h of incubation in n-hexane and dimethyl sulfoxide media. Graphical Abstract Divalent metal chelated polyethylenimine coated MCM-41 (MCM-41@PEI-M) was used for immobilization of Thermomyces lanuginosa lipase catalyzing green apple flavor preparation.

  14. Thermodynamics of Palladium (Pd) and Tantalum (Ta) Relevant to Secondary Copper Smelting

    NASA Astrophysics Data System (ADS)

    Shuva, M. A. H.; Rhamdhani, M. A.; Brooks, G. A.; Masood, S. H.; Reuter, M. A.

    2017-02-01

    The slag-to-metal distribution ratios of palladium (Pd), L_{{Pd}}^{s/m} , in the range of oxygen partial pressure ( pO2) from 10-10 to 10-7 atm at 1473 K to 1623 K (1200 °C to 1350 °C); distribution ratios of tantalum (Ta), L_{{Ta}}^{s/m} , in the range of pO2 from 10-16 to 10-12 atm at 1673 K and 1873 K (1400 °C and 1600 °C), have been determined in this study. The L_{{Pd}}^{s/m} in FeO x -CaO-SiO2-MgO and copper at 1573 K (1300 °C) and pO2 = 10-8 atm is dependant strongly on basicity of slag, i.e. (CaO + MgO)/SiO2 or optical basicity. The current results suggest that Pd presents in the FeO x -CaO-SiO2-MgO slag predominantly as Pd2+. The activity coefficient of PdO in the slag at 1573 K (1300 °C) and pO2 = 10-8 atm was calculated to be in the range of 3.89 × 10-3 to 2.63 × 10-2. The L_{{Pd}}^{s/m} was also found to increase with increasing of pO2 and with decreasing of temperature. It was observed that Ta mostly partition to slag phase and very small amount of Ta was found in liquid copper at the high temperature and reduced condition studied. It can be suggested that to promote recovery of palladium from Pd-containing e-waste, a slag with lower silica content and basic flux based, high temperature with reducing atmosphere, is highly desired particularly in secondary copper smelting.

  15. Relaxation of isolated guinea-pig trachea by apigenin, a constituent of celery, via inhibition of phosphodiesterase.

    PubMed

    Chen, Junn-Lain; Ko, Wun-Chang

    2017-09-15

    Apigenin, was reported to have vasodilatory effects by inhibiting Ca 2+ influx through both voltage- and receptor-operated calcium channels, but not by inhibiting cAMP- or cGMP-phosphodiesterases (PDEs) in rat thoracic aorta. However, apigenin was reported to inhibit PDE1, 2 and 3 in guinea-pig lung and heart. The aim of this study was to clarify that guinea-pig tracheal relaxation by apigenin whether via PDE inhibition. We isometrically recorded the tension of isolated guinea-pig tracheal segments on a polygraph. Antagonistic effects of apigenin against cumulative contractile agents or Ca 2+ induced contractions of the trachealis in normal or isotonic high-K + , Ca 2+ -free Krebs solution, respectively. Effects of apigenin (15 and 30μM) on the cumulative forskolin- and nitroprusside-induced relaxations to histamine (30μM)-induced precontraction were performed. The inhibitory effects of 30-300μM apigenin and 3-isobutyl-1-methylxanthine (IBMX, positive control) on the cAMP- and cGMP-PDEs were determined. Apigenin concentration-dependently but non-competitively inhibited cumulative histamine-, carbachol- or Ca 2+ -induced contractions in normal or in the depolarized (K + , 60mM) trachealis, suggesting that Ca 2+ influx through voltage-dependent calcium channels is inhibited. However, apigenin (15-30μM) parallel leftward shifted the concentration-response curves of forskolin and nitroprusside, and significantly increased the pD 2 values of these two cyclase activators. Both apigenin and IBMX, a reference drug, concentration (10-300μM)-dependently and significantly, but non-selectively inhibited the activities of cAMP- and cGMP-PDEs in the trachealis. In conclusion, the relaxant effect of apigenin may be due to inhibition of both enzyme activities and reduction of intracellular Ca 2+ by inhibiting Ca 2+ influx in the trachealis. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Resistance training controls arterial blood pressure in rats with L-NAME- induced hypertension.

    PubMed

    Araujo, Ayslan Jorge Santos de; Santos, Anne Carolline Veríssimo dos; Souza, Karine dos Santos; Aires, Marlúcia Bastos; Santana-Filho, Valter Joviniano; Fioretto, Emerson Ticona; Mota, Marcelo Mendonça; Santos, Márcio Roberto Viana

    2013-04-01

    Arterial hypertension is a multifactorial chronic condition caused by either congenital or acquired factors. To evaluate the effects of Resistance Training (RT) on arterial pressure, and on vascular reactivity and morphology, of L-NAME-treated hypertensive rats. Male Wistar rats (200 - 250 g) were allocated into Sedentary Normotensive (SN), Sedentary Hypertensive (SH) and Trained Hypertensive (TH) groups. Hypertension was induced by adding L-NAME (40 mg/Kg) to the drinking water for four weeks. Arterial pressure was evaluated before and after RT. RT was performed using 50% of 1RM, 3 sets of 10 repetitions, 3 times per week for four weeks. Vascular reactivity was measured in rat mesenteric artery rings by concentration-response curves to sodium nitroprusside (SNP); phenylephrine (PHE) was also used for histological and stereological analysis. Resistance training inhibited the increase in mean and diastolic arterial pressures. Significant reduction was observed in Rmax (maximal response) and pD2 (potency) of PHE between SH and TH groups. Arteries demonstrated normal intima, media and adventitia layers in all groups. Stereological analysis demonstrated no significant difference in luminal, tunica media, and total areas of arteries in the SH and TH groups when compared to the SN group. Wall-to-lumen ratio of SH arteries was significantly different compared to SN arteries (p<0.05) but there was no difference when compared to TH arteries. RT was able to prevent an increase in blood pressure under the conditions in this study. This appears to involve a vasoconstrictor regulation mechanism and maintenance of luminal diameter in L-NAME induced hypertensive rats.

  17. Validating a Coarse-Grained Potential Energy Function through Protein Loop Modelling

    PubMed Central

    MacDonald, James T.; Kelley, Lawrence A.; Freemont, Paul S.

    2013-01-01

    ://www.sbg.bio.ic.ac.uk/phyre2/PD2/. PMID:23824634

  18. Interplay between the spin-selection rule and frontier orbital theory in O2 activation and CO oxidation by single-atom-sized catalysts on TiO2(110).

    PubMed

    Li, Shunfang; Zhao, Xingju; Shi, Jinlei; Jia, Yu; Guo, Zhengxiao; Cho, Jun-Hyung; Gao, Yanfei; Zhang, Zhenyu

    2016-09-28

    Exploration of the catalytic activity of low-dimensional transition metal (TM) or noble metal catalysts is a vital subject of modern materials science because of their instrumental role in numerous industrial applications. Recent experimental advances have demonstrated the utilization of single atoms on different substrates as effective catalysts, which exhibit amazing catalytic properties such as more efficient catalytic performance and higher selectivity in chemical reactions as compared to their nanostructured counterparts; however, the underlying microscopic mechanisms operative in these single atom catalysts still remain elusive. Based on first-principles calculations, herein, we present a comparative study of the key kinetic rate processes involved in CO oxidation using a monomer or dimer of two representative TMs (Pd and Ni) on defective TiO2(110) substrates (TMn@TiO2(110), n = 1, 2) to elucidate the underlying mechanism of single-atom catalysis. We reveal that the O2 activation rates of the single atom TM catalysts deposited on TiO2(110) are governed cooperatively by the classic spin-selection rule and the well-known frontier orbital theory (or generalized d-band picture) that emphasizes the energy gap between the frontier orbitals of the TM catalysts and O2 molecule. We further illuminate that the subsequent CO oxidation reactions proceed via the Langmuir-Hinshelwood mechanism with contrasting reaction barriers for the Pd monomer and dimer catalysts. These findings not only provide an explanation for existing observations of distinctly different catalytic activities of Pd@TiO2(110) and Pd2@TiO2(110) [Kaden et al., Science, 2009, 326, 826-829] but also shed new insights into future utilization and optimization of single-atom catalysis.

  19. Bimetallic catalysis involving dipalladium(I) and diruthenium(I) complexes.

    PubMed

    Das, Raj K; Saha, Biswajit; Rahaman, S M Wahidur; Bera, Jitendra K

    2010-12-27

    Dipalladium(I) and diruthenium(I) compounds bridged by two [{(5,7-dimethyl-1,8-naphthyridin-2-yl)amino}carbonyl]ferrocene (L) ligands have been synthesized. The X-ray structures of [Pd(2)L(2)][BF(4)](2) (1) and [Ru(2)L(2)(CO)(4)][BF(4)](2) (2) reveal dinuclear structures with short metal-metal distances. In both of these structures, naphthyridine bridges the dimetal unit, and the site trans to the metal-metal bond is occupied by weakly coordinating oxygen from the amido fragment. The catalytic utilities of these bimetallic compounds are evaluated. Compound 1 is an excellent catalyst for phosphine-free, Suzuki cross-coupling reactions of aryl bromides with arylboronic acids and provides high yields in short reaction times. Compound 1 is also found to be catalytically active for aryl chlorides, although the corresponding yields are lower. A bimetallic mechanism is proposed, which involves the oxidative addition of aryl bromide across the Pd-Pd bond and the bimetallic reductive elimination of the product. Compound 1 is also an efficient catalyst for the Heck cross-coupling of aryl bromides with styrenes. The mechanism for aldehyde olefination with ethyl diazoacetate (EDA) and PPh(3), catalyzed by 2, has been fully elucidated. It is demonstrated that 2 catalyzes the formation of phosphorane utilizing EDA and PPh(3), which subsequently reacts with aldehyde to produce a new olefin and phosphine oxide. The efficacy of bimetallic complexes in catalytic organic transformations is illustrated in this work.

  20. Reactive oxygen species potentiate the negative inotropic effect of cardiac M2-muscarinic receptor stimulation.

    PubMed

    Peters, S L; Sand, C; Batinik, H D; Pfaffendorf, M; van Zwieten, P A

    2001-08-01

    The aim of the present study was to investigate the influence of reactive oxygen species (ROS) on the contractile responses of rat isolated left atria to muscarinic receptor stimulation. ROS were generated by means of electrolysis (30 mA, 75 s) of the organ bath fluid. Twenty minutes after the electrolysis period, the electrically paced atria (3 Hz) were stimulated with the adenylyl cyclase activator forskolin (1 microM). Subsequently, cumulative acetylcholine concentration-response curves were constructed (0.01 nM-10 microM). In addition, phosphoinositide turnover and adenylyl cyclase activity under basal and stimulated conditions were measured. For these biochemical experiments we used the stable acetylcholine analogue carbachol. The atria exposed to reactive oxygen species were influenced more potently (pD2 control: 6.2 vs. 7.1 for electrolysis-treated atria, P<0.05) and more effectively (Emax control: 40% vs. 90% reduction of the initial amplitude, P<0.05) by acetylcholine. In contrast, ROS exposure did not alter the responses to adenosine, whose receptor is also coupled via a Gi-protein to adenylyl cyclase. The basal (40% vs. control, P<0.05) as well as the carbachol-stimulated (-85% vs. control, P<0.05) inositol-phosphate formation was reduced in atria exposed to ROS. The forskolin-stimulated adenylyl cyclase activity was identical in both groups but carbachol stimulation induced a more pronounced reduction in adenylyl cyclase activity in the electrolysis-treated atria. Accordingly we may conclude that ROS enhance the negative inotropic response of isolated rat atria to acetylcholine by both a reduction of the positive (inositide turnover) and increase of the negative (adenylyl cyclase inhibition) inotropic components of cardiac muscarinic receptor stimulation. This phenomenon is most likely M2-receptor specific, since the negative inotropic response to adenosine is unaltered by ROS exposure.

  1. Drooling in Parkinson's disease: A randomized controlled trial of incobotulinum toxin A and meta-analysis of Botulinum toxins.

    PubMed

    Narayanaswami, Pushpa; Geisbush, Thomas; Tarulli, Andrew; Raynor, Elizabeth; Gautam, Shiva; Tarsy, Daniel; Gronseth, Gary

    2016-09-01

    Botulinum toxins are a therapeutic option for drooling in Parkinson's Disease (PD). The aims of this study were to: 1. evaluate the efficacy of incobotulinum toxin A for drooling in PD. 2. Perform a meta-analysis of studies of Botulinum toxins for drooling in PD. 1. Primary study: Randomized, double blind, placebo controlled, cross over trial. Incobotulinum toxin (100 units) or saline was injected into the parotid (20 units) and submandibular (30 units) glands. Subjects returned monthly for three evaluations after each injection. Outcome measures were saliva weight and Drooling Frequency and Severity Scale. 2. Systematic review of literature, followed by inverse variance meta-analyses using random effects models. 1. Primary Study: Nine of 10 subjects completed both arms. There was no significant change in the primary outcome of saliva weight one month after injection in the treatment period compared to placebo period (mean difference, gm ± SD: -0.194 ± 0.61, range: -1.28 to 0.97, 95% CI -0.71 to 0.32). Secondary outcomes also did not change. 2. Meta-analysis of six studies demonstrated significant benefit of Botulinum toxin on functional outcomes (effect size, Cohen's d: -1.32, CI -1.86 to -0.78). The other studies used a higher dose of Botulinum toxin A into the parotid glands. This study did not demonstrate efficacy of incobotulinum toxin A for drooling in PD, but lacked precision to exclude moderate benefit. The parotid/submandibular dose-ratio may have influenced results. Studies evaluating higher doses of incobotulinum toxin A into the parotid glands may be useful. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. State Anxiety and Nonlinear Dynamics of Heart Rate Variability in Students

    PubMed Central

    Dimitriev, Aleksey D.

    2016-01-01

    Objectives Clinical and experimental research studies have demonstrated that the emotional experience of anxiety impairs heart rate variability (HRV) in humans. The present study investigated whether changes in state anxiety (SA) can also modulate nonlinear dynamics of heart rate. Methods A group of 96 students volunteered to participate in the study. For each student, two 5-minute recordings of beat intervals (RR) were performed: one during a rest period and one just before a university examination, which was assumed to be a real-life stressor. Nonlinear analysis of HRV was performed. The Spielberger’s State-Trait Anxiety Inventory was used to assess the level of SA. Results Before adjusting for heart rate, a Wilcoxon matched pairs test showed significant decreases in Poincaré plot measures, entropy, largest Lyapunov exponent (LLE), and pointwise correlation dimension (PD2), and an increase in the short-term fractal-like scaling exponent of detrended fluctuation analysis (α1) during the exam session, compared with the rest period. A Pearson analysis indicated significant negative correlations between the dynamics of SA and Poincaré plot axes ratio (SD1/SD2), and between changes in SA and changes in entropy measures. A strong negative correlation was found between the dynamics of SA and LLE. A significant positive correlation was found between the dynamics of SA and α1. The decreases in Poincaré plot measures (SD1, complex correlation measure), entropy measures, and LLE were still significant after adjusting for heart rate. Corrected α1 was increased during the exam session. As before, the dynamics of adjusted LLE was significantly correlated with the dynamics of SA. Conclusions The qualitative increase in SA during academic examination was related to the decrease in the complexity and size of the Poincaré plot through a reduction of both the interbeat interval and its variation. PMID:26807793

  3. Kinetic and thermodynamic studies of the Co(II) and Ni(II) ions removal from aqueous solutions by Ca-Mg phosphates.

    PubMed

    Ivanets, A I; Srivastava, V; Kitikova, N V; Shashkova, I L; Sillanpää, M

    2017-03-01

    The aim of this work was to study the sorption kinetics and thermodynamics of Co(II) and Ni(II) from aqueous solutions by sorbents on the basis of hydrogen (PD-1) and tertiary (PD-2) Ca-Mg phosphates depending on the solution temperature and sorbents chemical composition. Kinetic studies of adsorption of Co(II) and Ni(II) ions onto samples of phosphate sorbents were performed in batch experiment at the temperatures 288, 303, 318 and 333 K. The sorbent dose was fixed at 10 g L -1 , initial pH value 2.6, and contact time varied from 5 to 600 min. The kinetics of Co(II) and Ni(II) adsorption were analyzed by using pseudo-first order, pseudo-second order and intraparticle diffusion models. Thermodynamic parameters (ΔG°, ΔH° and ΔS°) for the sorption of Co(II) and Ni(II) were determined using the Gibbs-Helmholtz equation. The calculated kinetic parameters and corresponding correlation coefficients revealed that Co(II) and Ni(II) uptake process followed the pseudo-second order rate expression. Thermodynamic studies confirmed the spontaneous and endothermic nature of removal process which indicate that sorption of Co(II) and Ni(II) ions onto both phosphate sorbents is favoured at higher temperatures and has the chemisorptive mechanism. The data thus obtained would be useful for practical application of the low cost and highly effective Ca-Mg phosphate sorbents. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Longitudinal DSC-MRI for Distinguishing Tumor Recurrence From Pseudoprogression in Patients With a High-grade Glioma.

    PubMed

    Boxerman, Jerrold L; Ellingson, Benjamin M; Jeyapalan, Suriya; Elinzano, Heinrich; Harris, Robert J; Rogg, Jeffrey M; Pope, Whitney B; Safran, Howard

    2017-06-01

    For patients with high-grade glioma on clinical trials it is important to accurately assess time of disease progression. However, differentiation between pseudoprogression (PsP) and progressive disease (PD) is unreliable with standard magnetic resonance imaging (MRI) techniques. Dynamic susceptibility contrast perfusion MRI (DSC-MRI) can measure relative cerebral blood volume (rCBV) and may help distinguish PsP from PD. A subset of patients with high-grade glioma on a phase II clinical trial with temozolomide, paclitaxel poliglumex, and concurrent radiation were assessed. Nine patients (3 grade III, 6 grade IV), with a total of 19 enhancing lesions demonstrating progressive enhancement (≥25% increase from nadir) on postchemoradiation conventional contrast-enhanced MRI, had serial DSC-MRI. Mean leakage-corrected rCBV within enhancing lesions was computed for all postchemoradiation time points. Of the 19 progressively enhancing lesions, 10 were classified as PsP and 9 as PD by biopsy/surgery or serial enhancement patterns during interval follow-up MRI. Mean rCBV at initial progressive enhancement did not differ significantly between PsP and PD (2.35 vs. 2.17; P=0.67). However, change in rCBV at first subsequent follow-up (-0.84 vs. 0.84; P=0.001) and the overall linear trend in rCBV after initial progressive enhancement (negative vs. positive slope; P=0.04) differed significantly between PsP and PD. Longitudinal trends in rCBV may be more useful than absolute rCBV in distinguishing PsP from PD in chemoradiation-treated high-grade gliomas with DSC-MRI. Further studies of DSC-MRI in high-grade glioma as a potential technique for distinguishing PsP from PD are indicated.

  5. In vitro and in vivo biological activities of SR140333, a novel potent non-peptide tachykinin NK1 receptor antagonist.

    PubMed

    Emonds-Alt, X; Doutremepuich, J D; Heaulme, M; Neliat, G; Santucci, V; Steinberg, R; Vilain, P; Bichon, D; Ducoux, J P; Proietto, V

    1993-12-21

    (S)1-(2-[3-(3,4-dichlorophenyl)-1-(3-isopropoxyphenylacetyl)pip eridin-3- yl]ethyl)-4-phenyl-1-azoniabicyclo[2.2.2]octane chloride (SR140333) is a new non-peptide antagonist of tachykinin NK1 receptors. SR140333 potently, selectively and competitively inhibited substance P binding to NK1 receptors from various animal species, including humans. In vitro, it was a potent antagonist in functional assays for NK1 receptors such as [Sar9,Met(O2)11]substance P-induced endothelium-dependent relaxation of rabbit pulmonary artery and contraction of guinea-pig ileum. Up to 1 microM, it had no effect in bioassays for NK2 ([beta Ala8]neurokinin A-induced contraction of endothelium-deprived rabbit pulmonary artery) and NK3 ([MePhe7]neurokinin B-induced contraction of rat portal vein) receptors. The antagonism exerted by SR140333 toward NK1 receptors was apparently non-competitive, with pD2' values (antagonism potency evaluated by the negative logarithm of the molar concentration of antagonist that produces a 50% reduction of the maximal response to the agonist) between 9.65 and 10.16 in the different assays. SR140333 also blocked in vitro [Sar9,Met(O2)11]substance P-induced release of acetylcholine from rat striatum. In vivo, SR140333 exerted highly potent antagonism toward [Sar9,Met(O2)11]substance P-induced hypotension in dogs (ED50 = 3 micrograms/kg i.v.), bronchoconstriction in guinea-pig (ED50 = 42 micrograms/kg i.v.) and plasma extravasation in rats (ED50 = 7 micrograms/kg i.v.). Finally, it also blocked the activation of rat thalamic neurons after nociceptive stimulation (ED50 = 0.2 micrograms/kg i.v.).

  6. Quantitative Analysis of Voice in Parkinson Disease Compared to Motor Performance: A Pilot Study.

    PubMed

    Silbergleit, Alice K; LeWitt, Peter A; Peterson, Edward L; Gardner, Glendon M

    2015-01-01

    Characteristic features of hypokinetic dysarthria develop in Parkinson disease (PD). We hypothesized that quantified acoustic changes of voice might provide a correlate of disease severity. To determine if there are significant differences in acoustic measures of voice between mild and moderate PD; 2) To evaluate correlations between acoustic parameters of voice and subtests of the UPDRS in mild and moderate PD. Twenty six participants with PD underwent vocal acoustic testing while off PD medication, for comparison to 22 healthy controls. Participants with PD were divided into two groups based upon UPDRS activities of daily living (ADL) ratings: summed scores were used to define mild and moderate PD. Participants voiced /i/ ("ee") at comfort, high, and low pitch (3 trials/pitch). The CSpeech Waveform Analysis Program was used to analyze cycle-to-cycle frequency ("jitter") and amplitude ("shimmer") irregularities of the vocal signal, signal-to-noise ratio, and maximum phonation frequency range converted to semitones. Sections of UPDRS scores were correlated to acoustic variables of voice. Key findings included a significant difference between the semitone range of the control subjects and the moderate PD group (p = 0.036). Further analyses revealed significant differences in semitone range for males between the controls vs. mild PD (p = 0.014), and controls vs. moderate PD (p = 0.005). Significant correlations were also found between acoustic findings and both the ADL and motor portions of the UPDRS. Acoustic analysis of voice, particularly frequency range, may provide a quantifiable correlate of disease progression in PD.

  7. Time- and frequency-domain parameters of heart rate variability and sympathetic skin response in Parkinson's disease.

    PubMed

    Maetzler, Walter; Karam, Marie; Berger, Monika Fruhmann; Heger, Tanja; Maetzler, Corina; Ruediger, Heinz; Bronzova, Juliana; Lobo, Patricia Pita; Ferreira, Joaquim J; Ziemssen, Tjalf; Berg, Daniela

    2015-03-01

    The autonomic nervous system (ANS) is regularly affected in Parkinson's disease (PD). Information on autonomic dysfunction can be derived from e.g. altered heart rate variability (HRV) and sympathetic skin response (SSR). Such parameters can be quantified easily and measured repeatedly which might be helpful for evaluating disease progression and therapeutic outcome. In this 2-center study, HRV and SSR of 45 PD patients and 26 controls were recorded. HRV was measured during supine metronomic breathing and analyzed in time- and frequency-domains. SSR was evoked by repetitive auditory stimulation. Various ANS parameters were compared (1) between patients and healthy controls, (2) to clinical scales (Unified Parkinson's disease rating scale, Mini-Mental State Examination, Becks Depression Inventory), and (3) to disease duration. Root mean square of successive differences (RMSSD) and low frequency/high frequency (LF/HF) ratio differed significantly between PD and controls. Both, HRV and SSR parameters showed low or no association with clinical scores. Time-domain parameters tended to be affected already at early PD stages but did not consistently change with longer disease duration. In contrast, frequency-domain parameters were not altered in early PD phases but tended to be lower (LF, LF/HF ratio), respectively higher (HF) with increasing disease duration. This report confirms previous results of altered ANS parameters in PD. In addition, it suggests that (1) these ANS parameters are not relevantly associated with motor, behavioral, and cognitive changes in PD, (2) time-domain parameters are useful for the assessment of early PD, and (3) frequency-domain parameters are more closely associated with disease duration.

  8. Synthesis, spectroscopic characterization and in vitro cytotoxicities of new organometallic palladium complexes with biologically active β-diketones; Biological evaluation probing of the interaction mechanism with DNA/Protein and molecular docking

    NASA Astrophysics Data System (ADS)

    Karami, Kazem; Rafiee, Mina; Lighvan, Zohreh Mehri; Zakariazadeh, Mostafa; Faal, Ali Yeganeh; Esmaeili, Seyed-Alireza; Momtazi-Borojeni, Amir Abbas

    2018-02-01

    [Pd{(C,N)sbnd C6H4CH (CH3)NH}(CUR)] (3) and [Pd2{(C,N)sbnd C6H4CH(CH3)NH2}2(μ-N3CS2)] (4) [cur = 1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dion] novel organometallic complexes with biologically active ligands have been prepared and characterized via elemental analysis, multinuclear spectroscopic techniques (1H, and 13C NMR and IR) and their biological activities, including antitumoral activity and DNA-protein interactions have been investigated. Fluorescence spectroscopy used to study the interaction of the complexes with BSA have shown the affinity of the complexes for these proteins with relatively high binding constant values and the changed secondary structure of BSA in the presence of the complexes. In the meantime, spectroscopy and competitive titration have been applied to investigate the interaction of complexes with Warfarin and Ibuprofen site markers for sites I and II, respectively, with BSA. The results have suggested that the locations of complexes 3 and 4 are sites II and I, respectively. UV-Vis spectroscopy, emission titration and helix melting methods have been used to study the interaction of these complexes with CT-DNA, indicating that complexes are bound to CT-DNA by intercalation binding mode. In addition, good cytotoxic activity against MCF-7 (human breast cancer) and JURKAT (human leukemia) cell line has been shown by both complexes whereas low cytotoxicity was exerted on normal peripheral blood mononuclear cells.

  9. CORRELATION BETWEEN METAL-CERAMIC BOND STRENGTH AND COEFFICIENT OF LINEAR THERMAL EXPANSION DIFFERENCE

    PubMed Central

    Lopes, Stella Crosara; Pagnano, Valéria Oliveira; Rollo, João Manuel Domingos de Almeida; Leal, Mônica Barbosa; Bezzon, Osvaldo Luiz

    2009-01-01

    The purpose of this study was to evaluate the metal-ceramic bond strength (MCBS) of 6 metal-ceramic pairs (2 Ni-Cr alloys and 1 Pd-Ag alloy with 2 dental ceramics) and correlate the MCBS values with the differences between the coefficients of linear thermal expansion (CTEs) of the metals and ceramics. Verabond (VB) Ni-Cr-Be alloy, Verabond II (VB2), Ni-Cr alloy, Pors-on 4 (P), Pd-Ag alloy, and IPS (I) and Duceram (D) ceramics were used for the MCBS test and dilatometric test. Forty-eight ceramic rings were built around metallic rods (3.0 mm in diameter and 70.0 mm in length) made from the evaluated alloys. The rods were subsequently embedded in gypsum cast in order to perform a tensile load test, which enabled calculating the CMBS. Five specimens (2.0 mm in diameter and 12.0 mm in length) of each material were made for the dilatometric test. The chromel-alumel thermocouple required for the test was welded into the metal test specimens and inserted into the ceramics. ANOVA and Tukey's test revealed significant differences (p=0.01) for the MCBS test results (MPa), with PI showing higher MCBS (67.72) than the other pairs, which did not present any significant differences. The CTE (10-6 °C-1) differences were: VBI (0.54), VBD (1.33), VB2I (-0.14), VB2D (0.63), PI (1.84) and PD (2.62). Pearson's correlation test (r=0.17) was performed to evaluate of correlation between MCBS and CTE differences. Within the limitations of this study and based on the obtained results, there was no correlation between MCBS and CTE differences for the evaluated metal-ceramic pairs. PMID:19274398

  10. Contractile properties of the pig bladder mucosa in response to neurokinin A: a role for myofibroblasts?

    PubMed Central

    Sadananda, P; Chess-Williams, R; Burcher, E

    2008-01-01

    Background and purpose: The bladder urothelium is now known to have active properties. Our aim was to investigate the contractile properties of the urinary mucosa in response to the tachykinin neurokinin A (NKA) and carbachol. Experimental approach: Discrete concentration–response curves for carbachol and NKA were obtained in matched strips of porcine detrusor, mucosa and intact bladder, suspended in organ baths. The effects of inhibitors and tachykinin receptor antagonists were studied on NKA-mediated contractions in mucosal strips. Intact sections of bladder and experimental strips were processed for histology and immunohistochemistry. Key results: All types of strips contracted to both carbachol and NKA. Mucosal responses to NKA (pD2 7.2) were higher than those in intact strips and were inhibited by the NK2 receptor antagonist SR48968 (pKB 9.85) but not the NK1 receptor antagonist SR140333, tetrodotoxin or indomethacin. Immunostaining for smooth muscle actin and vimentin occurred under the urothelium and on blood vessels. Desmin immunostaining and histological studies showed only sparse smooth muscle to be present in the mucosal strips. Removal of smooth muscle remnants from mucosal strips did not alter the responses to NKA. Conclusions and implications: This study has shown both functional and histological evidence for contractile properties of the mucosa, distinct from the detrusor. Mucosal contractions to NKA appear to be directly mediated via NK2 receptors. The main cell type mediating mucosal contractions is suggested to be suburothelial myofibroblasts. Mucosal contractions may be important in vivo for matching the luminal surface area to bladder volume. PMID:18264120

  11. PdCo nanoparticles supported on carbon fibers derived from cotton: Maximum utilization of Pd atoms for efficient reduction of nitroarenes.

    PubMed

    Yang, Jin; Wang, Wei David; Dong, Zhengping

    2018-08-15

    In the present work, a facile and environment-friendly route is illustrated for the efficient fabrication of highly dispersed PdCo nanoparticles (NPs) by modified cotton-derived carbon fibers (PdCo/CCF). Firstly, commercial cotton was impregnated with CoCl 2 , followed by pyrolysis under high calcination temperature to obtain the Co NPs modified CCF sample (Co/CCF). Secondly, Co/CCF was treated with Pd(AcO) 2 aqueous solution, wherein, through a spontaneous replacement reaction process, Pd 2+ is reduced to metallic Pd and mostly covered on the surface of the Co NPs. Thus, the PdCo/CCF catalyst was obtained avoiding the use of toxic reductants like NaBH 4 , NH 2 NH 2 and HCHO. The PdCo/CCF catalyst exhibits excellent catalytic activity and recyclability for the reduction of 4-nitrophenol and other nitroarenes compared with Pd/CCF, PdCo NPs and many other noble metals based catalysts. The reasons could be attributed to the uniformly dispersed and accessible PdCo NPs on the surface of the CCF, and the Pd atoms deposited on the Co NPs surface that makes the Pd active sites available for optimum use. The PdCo/CCF catalyst also exhibits potential application for catalytic reduction of nitroarenes in a fixed bed reactor under mild reaction conditions. Furthermore, the PdCo/CCF catalyst can be magnetically recycled and reused for at least ten cycles without either losing catalytic activity or leaching of Pd active sites, thereby confirming its superior stability. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Well-Coupled Nanohybrids Obtained by Component-Controlled Synthesis and in Situ Integration of Mn xPd y Nanocrystals on Vulcan Carbon for Electrocatalytic Oxygen Reduction.

    PubMed

    Lu, Yanan; Zhao, Shulin; Yang, Rui; Xu, Dongdong; Yang, Jing; Lin, Yue; Shi, Nai-En; Dai, Zhihui; Bao, Jianchun; Han, Min

    2018-03-07

    Development of cheap, highly active, and robust bimetallic nanocrystal (NC)-based nanohybrid (NH) electrocatalysts for oxygen reduction reaction (ORR) is helpful for advancing fuel cells or other renewable energy technologies. Here, four kinds of well-coupled Mn x Pd y (MnPd 3 , MnPd-Pd, Mn 2 Pd 3 , Mn 2 Pd 3 -Mn 11 Pd 21 )/C NHs have been synthesized by in situ integration of Mn x Pd y NCs with variable component ratios on pretreated Vulcan XC-72 C using the solvothermal method accompanied with annealing under Ar/H 2 atmosphere and used as electrocatalysts for ORR. Among them, the MnPd 3 /C NHs possess the unique "half-embedded and half-encapsulated" interfaces and exhibit the highest catalytic activity, which can compete with some currently reported non-Pt catalysts (e.g., Ag-Co nanoalloys, Pd 2 NiAg NCs, PdCo/N-doped porous C, G-Cu 3 Pd nanocomposites, etc.), and close to commercial Pt/C. Electrocatalytic dynamic measurements disclose that their ORR mechanism abides by the direct 4e - pathway. Moreover, their durability and methanol-tolerant capability are much higher than that of Pt/C. As revealed by spectroscopic and electrochemical analyses, the excellent catalytic performance of MnPd 3 /C NHs results from the proper component ratio of Mn and Pd and the strong interplay of their constituents, which not only facilitate to optimize the d-band center or the electronic structure of Pd but also induce the phase transformation of MnPd 3 active components and enhance their conductivity or interfacial electron transfer dynamics. This work demonstrates that MnPd 3 /C NHs are promising methanol-tolerant cathode electrocatalysts that may be employed in fuel cells or other renewable energy option.

  13. PSP as distinguished from CBD, MSA-P and PD by clinical and imaging differences at an early stage.

    PubMed

    Kurata, Tomoko; Kametaka, Satsuki; Ohta, Yasuyuki; Morimoto, Nobutoshi; Deguchi, Shoko; Deguchi, Kentaro; Ikeda, Yoshio; Takao, Yoshiki; Ohta, Taisei; Manabe, Yasuhiro; Sato, Shuhei; Abe, Koji

    2011-01-01

    Because it is often difficult to precisely diagnose and distinguish progressive supranuclear palsy (PSP) from corticobasal degeneration (CBD), multiple system atrophy-parkinsonism (MSA-P) and Parkinson's disease (PD) at the onset of the disease, we compared the patients and clarified the features of these diseases. We compared 77 PSP, 26 CBD, 26 MSA-P and 166 PD patients from clinical and imaging points of view including cerebral blood flow (CBF) in the frontal eye field. The clinical characteristics of PSP were supranuclear gaze disturbance, optokinetic nystagmus (OKN) impairment and falls at the first visit. On head MRI, midbrain tegmentum atrophy was much more frequently detected in PSP than in all of the other groups. Heart-to-mediastinum average count ratio (H/M) in iodine-123 meta-iodobenzyl guanidine ((123)I-MIBG) myocardial scintigraphy was not decreased in PSP, CBD, MSA-P and PD-Yahr 1 (-1), but patients of PD-2, 3, 4 and 5 showed a significant decrease compared with the PSP group. The CBF in the left frontal eye field of PD-3 group and that in right frontal eye field of PD-3 and PD-4 groups were lower than that of PSP group, although other groups showed a tendency without a significant decrease compared with PSP group. PSP is distinguishable from CBD, MSA-P and PD even at the early stage with extra-ocular movement (EOM) disturbance, falls, atrophy of the midbrain tegmentum, and H/M in (123)I-MIBG myocardial scintigraphy, and the reduction of CBF in area 8 could serve as a supplemental diagnostic method for distinguishing PSP from PD-3 or PD-4.

  14. The Extension of Colloid Chemistry from Aqueous to Non-Aqueous Media with Application to Nanofluid Research

    NASA Astrophysics Data System (ADS)

    Clary, Dan

    Cyclodextrins are cyclic molecules composed of glucose units. The inner cavity of cyclodextrins is noted for its ability to form stable inclusion complexes with a wide variety of guests. A cyclodextrin-glucose host-guest complex was prepared and utilized as both a salt reductant and a particle stabilizer in the generation of aqueous metal colloids including Ag, Au, Pd, and Pt. The resulting colloids demonstrated remarkable stability---3 years and running, in some cases---and have been evaluated for thermal conductivity. Evaluation of the reaction products when the complex is used to reduce Pd 2+ demonstrated a unique comproportionation reaction in which the guest undergoes a two electron oxidation to produce a Pd atom. The resulting atom reduces a neighboring Pd2+ ion to yield two Pd + ions. The monovalent species, in contrast to Pd2+, can then oxidize the host to form atoms which rapidly aggregate to yield particles. Highly stable, crystalline copper(II) oxide particles were prepared which can be isolated as a powder and redispursed in low dielectric media such as hydrocarbons or chloroform. Mass concentrations of up to 20% (1.65 M) were achieved in octane, dodecane, and eicosane and remained stable for at least ten days at room temperature as observed by visible spectroscopy. Quasi-spherical particle shape was observed with the largest fraction possessing a diameter of 9 nm and 90% of the population existing within the range of 5 to 15 nm. The colloidal systems were characterized using FAA, XRD, TEM, UV-Vis, DSC, and a simple device inspired by Newton's Law of cooling which was employed to measure cooling/heating rates. Thermodynamic measurements of sodium oleate-stabilized CuO particles suspended in dodecane and eicosane reveal a decrease in Cp, DeltaH fus , and cooling/heating rates of the resulting colloid with large increases in particle mass concentration. Irradiation with 350 nm photons of anhydrous, air-free octane or toluene solutions of copper(II) oleate

  15. Conservation of the introgressed European water frog complex using molecular tools.

    PubMed

    Holsbeek, G; Maes, G E; De Meester, L; Volckaert, F A M

    2009-03-01

    In Belgium, the Pelophylax esculentus complex has recently been subjected to multiple introductions of non-native water frogs, increasing the occurrence of hybridisation events. In the present study, we tested the reliability of morphometric and recently developed microsatellite tools to identify introgression and to determine the origin of exotic Belgian water frogs. By analysing 150 individuals of each taxon of the P. esculentus complex and an additional 60 specimens of the introduced P. cf. bedriagae, we show that neither of the currently available tools appears to have sufficient power to reliably distinguish all Belgian water frog species. We therefore aimed at increasing the discriminatory power of a microsatellite identification tool by developing a new marker panel with additional microsatellite loci. By adding only two new microsatellite loci (RlCA5 and RlCA1b20), all taxa of the P. esculentus complex could be distinguished from each other with high confidence. Three more loci (Res3, Res5 and Res17) provided a powerful discrimination of the exotic species.

  16. Coupling of equatorial Atlantic surface stratification to glacial shifts in the tropical rainbelt.

    PubMed

    Portilho-Ramos, R C; Chiessi, C M; Zhang, Y; Mulitza, S; Kucera, M; Siccha, M; Prange, M; Paul, A

    2017-05-08

    The modern state of the Atlantic meridional overturning circulation promotes a northerly maximum of tropical rainfall associated with the Intertropical Convergence Zone (ITCZ). For continental regions, abrupt millennial-scale meridional shifts of this rainbelt are well documented, but the behavior of its oceanic counterpart is unclear due the lack of a robust proxy and high temporal resolution records. Here we show that the Atlantic ITCZ leaves a distinct signature in planktonic foraminifera assemblages. We applied this proxy to investigate the history of the Atlantic ITCZ for the last 30,000 years based on two high temporal resolution records from the western Atlantic Ocean. Our reconstruction indicates that the shallowest mixed layer associated with the Atlantic ITCZ unambiguously shifted meridionally in response to changes in the strength of the Atlantic meridional overturning with a southward displacement during Heinrich Stadials 2-1 and the Younger Dryas. We conclude that the Atlantic ITCZ was located at ca. 1°S (ca. 5° to the south of its modern annual mean position) during Heinrich Stadial 1. This supports a previous hypothesis, which postulates a southern hemisphere position of the oceanic ITCZ during climatic states with substantially reduced or absent cross-equatorial oceanic meridional heat transport.

  17. Why do orangutans leave the trees? Terrestrial behavior among wild Bornean orangutans (Pongo pygmaeus wurmbii) at Tuanan, Central Kalimantan.

    PubMed

    Ashbury, Alison M; Posa, Mary Rose C; Dunkel, Lynda P; Spillmann, Brigitte; Atmoko, S Suci Utami; van Schaik, Carel P; van Noordwijk, Maria A

    2015-11-01

    Orangutans (genus Pongo) are the largest arboreal mammals, but Bornean orangutans (P. pygmaeus spp.) also spend time on the ground. Here, we investigate ground use among orangutans using 32,000 hr of direct focal animal observations from a well-habituated wild population of Bornean orangutans (P. p. wurmbii) living in a closed-canopy swamp forest at Tuanan, Central Kalimantan, Indonesia. Ground use did not change with increasing observation time of well-habituated individuals, suggesting it was not an artifact of observer presence. Flanged males spent the most time on the ground (ca. 5% of active time), weaned immatures the least (around 1%). Females and immatures descended mainly to feed, especially on termites, whereas flanged males traveled more while on the ground. Flanged males may travel more inconspicuously, and perhaps also faster, when moving on the ground. In addition, orangutans engaged in ground-specific behavior, including drinking from and bathing in swamp pools. Supplementary records from 20 ground-level camera traps, totaling 3986 trap days, confirmed the observed age-sex biases in ground use at Tuanan. We conclude that ground use is a natural part of the Bornean orangutan behavioral repertoire, however it remains unclear to what extent food scarcity and canopy structure explain population differences in ground use. © 2015 Wiley Periodicals, Inc.

  18. Crustal Uplift In The Alps and Why The Drainage Pattern Matters: An Alternative Way To Interpret Geodetic Data

    NASA Astrophysics Data System (ADS)

    Schlunegger, F.; Hinderer, M.

    The Alpine drainage system comprises two large orogen-parallel drainage basins in the core of the Alps (the Rhone and Rhein valleys), and smaller orogen-normal ori- ented systems. Discharge of the large rivers is ca. 5-10 higher than that of the small ones. Also, the courses of the Rhone and Rhein Rivers are trapped by faults and thrusts that display lower erosional resistance than the neighbouring lithologies. Enhanced discharge of these rivers and low erosional resistance of bedrocks potentially enhances surface erosion. Indeed, present-day and glacial sediment yields have been ca. 1.6-1.7 times higher in these valleys than in the orogen-normal systems. Interestingly, geode- tic measurements indicate that rates of crustal uplift are also enhanced in the Rhein and Rhone valleys, where rates of ca. 1.4-1.6 mm/yr are currently measured. We inter- pret the spatial coincidence between the location of enhanced erosion and maximum crustal uplift rates to reflect a positive feedback between surface erosion and tectonic forcing.

  19. Genotyping of acute HBV isolates from England, 1997-2001.

    PubMed

    Sloan, Richard D; Strang, Angela L; Ramsay, Mary E; Teo, Chong-Gee

    2009-02-01

    Increasing data shows the relevance of HBV genotypes in the outcome of infection. Most studies investigating the relationship between the genotypic characteristics of hepatitis B virus (HBV) and the clinical or epidemiological aspects of HBV infection originate from studies of patients with chronic rather than acute hepatitis B. To study a convenience sample representing ca. 5% of reported acute hepatitis B in England between 1997 and 2001 to investigate the distribution of HBV genotypes and specific HBV variants with epidemiological risk factors, thereby providing baseline data for ongoing surveillance. From 160 serum samples, PCR was carried out to amplify the first 600 bases of the HBV S gene. Amplicons were sequenced and subjected to phylogenetic analysis and risk factor analysis. Fifty-seven percent of the study samples carried HBV belonging to subtype A2, 13% to subtype D2, and the rest to genotype E (8%) and subtypes C2 and D3 (each 6%), D1 and D4 (each 3%) and B4 (1%). One particular A2 isolate was dominant, accounting for 23% of the total sample set. Drug use and homosexual transmission were equally implicated as risks within genotype A2. No mutations associated with vaccine escape or resistance to antiviral therapy were identified. Immigration and travel likely shape the observed genotype distribution and consequent prevalence of genotypes other than A2 or D in this population. Data suggests no genetic separation of parenteral and sexually transmitted virus. These data demonstrate the value in pursuing more extensive and recent surveillance.

  20. A pacemaker powered by an implantable biofuel cell operating under conditions mimicking the human blood circulatory system--battery not included.

    PubMed

    Southcott, Mark; MacVittie, Kevin; Halámek, Jan; Halámková, Lenka; Jemison, William D; Lobel, Robert; Katz, Evgeny

    2013-05-07

    Biocatalytic electrodes made of buckypaper were modified with PQQ-dependent glucose dehydrogenase on the anode and with laccase on the cathode and were assembled in a flow biofuel cell filled with serum solution mimicking the human blood circulatory system. The biofuel cell generated an open circuitry voltage, Voc, of ca. 470 mV and a short circuitry current, Isc, of ca. 5 mA (a current density of 0.83 mA cm(-2)). The power generated by the implantable biofuel cell was used to activate a pacemaker connected to the cell via a charge pump and a DC-DC converter interface circuit to adjust the voltage produced by the biofuel cell to the value required by the pacemaker. The voltage-current dependencies were analyzed for the biofuel cell connected to an Ohmic load and to the electronic loads composed of the interface circuit, or the power converter, and the pacemaker to study their operation. The correct pacemaker operation was confirmed using a medical device - an implantable loop recorder. Sustainable operation of the pacemaker was achieved with the system closely mimicking human physiological conditions using a single biofuel cell. This first demonstration of the pacemaker activated by the physiologically produced electrical energy shows promise for future electronic implantable medical devices powered by electricity harvested from the human body.