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Sample records for mm ho ca

  1. Cryogenic Ho:CaF2 laser pumped by Tm:fiber laser

    NASA Astrophysics Data System (ADS)

    Jelínek, Michal; Kubeček, Václav; Ma, Weiwei; Zhao, Beibei; Jiang, Dapeng; Su, Liangbi

    2016-06-01

    The laser operation in the pulsed as well as continuous-wave regime of a modified-Bridgeman-grown 0.5 at.% Ho:CaF2 crystal at 83 K pumped by a Tm:fiber laser is reported. The maximum output power was 2.37 W at 2060 nm or 1.3 W at 2110 and 2130 nm. Continuous tuning range over 90 nm from 2030 to 2120 nm was achieved using a birefringent filter. The Ho:CaF2 fundamental spectroscopic properties as absorption and fluorescence spectra at 83 and 293 K are also presented.

  2. Visualiser of two-micron laser radiation based on Ho:CaF{sub 2} crystals

    SciTech Connect

    Lyapin, A A; Ryabochkina, P A; Ushakov, S N; Fedorov, P P

    2014-06-30

    The anti-Stokes luminescence spectra of Ho:CaF{sub 2} crystals corresponding to the {sup 5}G{sub 4} → {sup 5}I{sub 8}, {sup 5}G{sub 5} → {sup 5}I{sub 8}, {sup 5}F{sub 3} → {sup 5}I{sub 8}, {sup 5}F{sub 4}({sup 5}S{sub 2}) → {sup 5}I{sub 8}, {sup 5}F{sub 5} → {sup 5}I{sub 8}, {sup 5}S{sub 2} → {sup 5}I{sub 7}, {sup 5}I{sub 4} → {sup 5}I{sub 8}, {sup 5}I{sub 5} → {sup 5}I{sub 8}, {sup 5}F{sub 5} → {sup 5}I{sub 7}, {sup 5}F{sub 3} → {sup 5}I{sub 6}, {sup 5}I{sub 6} → {sup 5}I{sub 8}, {sup 5}F{sub 5} → {sup 5}I{sub 6}, and {sup 5}I{sub 5} → {sup 5}I{sub 7} transitions upon excitation of the {sup 5}I{sub 7} level of Ho{sup 3+} ions are studied. A method for visualisation of IR radiation in the two-micron range using Ho:CaF{sub 2} crystals is proposed. The energy efficiency of conversion of two-micron laser radiation to radiation in the red spectral range 620 – 690 nm by a 1 mol % HoF{sub 3}:CaF{sub 2} crystal is estimated to be no higher than 0.02%. (nonlinear optical phenomena)

  3. Multicolour upconversion emission from Ho3+-Tm3+-Yb3+ codoped CaMoO4 phosphor

    NASA Astrophysics Data System (ADS)

    Dey, Riya; Rai, Vineet Kumar

    2015-05-01

    The Ho3+-Tm3+-Yb3+ codoped CaMoO4 phosphor powder has been synthesized by chemical coprecipitation technique. For the structural investigation the X-ray diffraction analysis has been done. Multicolour upconversion (UC) emission in the visible region from the prepared material has been observed under the 980 nm near infrared (NIR) excitation. The UC emission bands ˜ 474 nm (blue), ˜ 541 nm (green) and ˜ 661 nm (red) region have been assigned as 1G4→3H6 (Tm3+), 5F45S2→5I8 (Ho3+) and 5F5→5I8 (Ho3+) transitions respectively.

  4. Adapting TESLA technology for future cw light sources using HoBiCaT.

    PubMed

    Kugeler, O; Neumann, A; Anders, W; Knobloch, J

    2010-07-01

    The HoBiCaT facility has been set up and operated at the Helmholtz-Zentrum-Berlin and BESSY since 2005. Its purpose is testing superconducting cavities in cw mode of operation and it was successfully demonstrated that TESLA pulsed technology can be used for cw mode of operation with only minor changes. Issues that were addressed comprise of elevated dynamic thermal losses in the cavity walls, necessary modifications in the cryogenics and the cavity processing, the optimum choice of operational parameters such as cavity temperature or bandwidth, the characterization of higher order modes in the cavity, and the usability of existing tuners and couplers for cw. PMID:20687747

  5. Adapting TESLA technology for future cw light sources using HoBiCaT

    NASA Astrophysics Data System (ADS)

    Kugeler, O.; Neumann, A.; Anders, W.; Knobloch, J.

    2010-07-01

    The HoBiCaT facility has been set up and operated at the Helmholtz-Zentrum-Berlin and BESSY since 2005. Its purpose is testing superconducting cavities in cw mode of operation and it was successfully demonstrated that TESLA pulsed technology can be used for cw mode of operation with only minor changes. Issues that were addressed comprise of elevated dynamic thermal losses in the cavity walls, necessary modifications in the cryogenics and the cavity processing, the optimum choice of operational parameters such as cavity temperature or bandwidth, the characterization of higher order modes in the cavity, and the usability of existing tuners and couplers for cw.

  6. Hydrides of CeNi/sub 5/, MmNi/sub 5/, Ca/sub 0/ /sub 2/(Ce/sub 0/ /sub 65/Mm/sub 0/ /sub 35/)/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Ce/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Mm/sub 0/ /sub 8/Ni/sub 5/, and mixed CeNi/sub 5//MmNi/sub 5/

    SciTech Connect

    Lakner, J.F.; Chow, T.S.

    1982-09-01

    Six intermetallic alloys (CeNi/sub 5/, MmNi/sub 5/, Ca/sub 0/ /sub 2/(Ce/sub 0/ /sub 65/Mm/sub 0/ /sub 35/)/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Ce/sub 0/ /sub 8/Ni/sub 5/, Ca/sub 0/ /sub 2/Mm/sub 0/ /sub 8/Ni/sub 5/, and a mixed alloy, CeNi/sub 5//MmNi/sub 5/) were investigated with respect to their suitability to provide high hydrogen capacity and their potential for use in providing substantial hydrogen pressure at both low and high temperatures. A second phase of our investigation dealt with ball-milling and hydriding and dehydriding cycles to produce fine particles for use in hydride powder transfer studies. A summary of several Van't Hoff plots is also included for hydride-forming alloys.

  7. Contrasting Effects of Ca{sup 2+} and Ho{sup 3+} Substitutions on Superconductivity and Excess conductivity of (Ho{sub 1-x}Ca{sub x})(Ba{sub 2-y}Ho{sub y})Cu{sub 3}O{sub 7-{delta}}

    SciTech Connect

    Maulud, M. F.; Hamidi, Z. S.; Yusof, A. A.; Yusof, M. I. M.; Yahya, A. K.

    2010-07-07

    Effects of Ho{sup 3+} and Ca{sup 2+} substitutions in (Ho{sub 1-x}Ca{sub x})(Ba{sub 2-y}Ho{sub y})Cu{sub 3}O{sub 7-{delta}}ceramics on normal and superconducting state behaviour were investigated. Electrical resistivity measurements showed increasing Ho{sup 3+} substitution at Ba{sup 2+} site (x = 0, 0.4, y = 0-0.4) caused normal state resistivity to change from metal-like to semimetal/semiconductor-like behaviour and suppressed T{sub c} from 89 K (y = 0) to 72 K (y = 0.4) while substitution of Ca{sup 2+} for Ho{sup 3+}((x = 0.2) 0.4, (y 0.4)) revives metallic behaviour of the normal state with increasing x. Excess conductivity analysis based on Asmalazov-Larkin theory showed 2D to 3D transition for all superconducting samples but with contrasting effects of the substitutions on AL{sub 2D} and AL{sub 3D} constants. The resistivity and excess conductivity results indicate effective hole filling Ho{sup 3+} and hole doping by by Ca{sup 2+} substitutions.

  8. The modulated structure and frequency upconversion properties of CaLa2(MoO4)4:Ho(3+)/Yb(3+) phosphors prepared by microwave synthesis.

    PubMed

    Lim, Chang Sung; Aleksandrovsky, Aleksandr; Molokeev, Maxim; Oreshonkov, Aleksandr; Atuchin, Victor

    2015-07-15

    CaLa2-x(MoO4)4:Ho(3+)/Yb(3+) phosphors with the doping concentrations of Ho(3+) and Yb(3+) (x = Ho(3+) + Yb(3+), Ho(3+) = 0.05; Yb(3+) = 0.35, 0.40, 0.45 and 0.50) have been successfully synthesized by the microwave sol-gel method. The modulated and averaged crystal structures of CaLa2-x(MoO4)4:Ho(3+)/Yb(3+) molybdates have been found by the Rietveld method, and the upconversion photoluminescence properties have been investigated. The synthesized particles, being formed after the heat-treatment at 900 °C for 16 h, showed a highly crystallized state. Under the excitation at 980 nm, CaLa2-x(MoO4)4:Ho(3+)/Yb(3+) particles exhibited strong 545 and 655 nm emission bands in the green and red regions. When the Yb(3+) : Ho(3+) ratios are 9 : 1 and 10 : 1, the UC intensity of CaLa1.5(MoO4)4:Yb0.45/Ho0.05 and CaLa1.45(MoO4)4:Yb0.50/Ho0.05 particles is the highest for different bands. The CIE coordinates calculated for CaLa2-x(MoO4)4:Ho(3+)/Yb(3+) phosphors are related to the yellow color field. The Raman spectrum of undoped CaLa2(MoO4)4 has revealed about 13 narrow lines. The strongest band observed at 906 cm(-1) was assigned to the ν1 symmetric stretching vibration of MoO4 tetrahedra. The spectra of the samples doped with Ho and Yb, as obtained under the 514.5 nm excitation, were dominated by Ho(3+) luminescence over the wavenumber range of >700 cm(-1) preventing the recording of the Raman spectra. PMID:26138938

  9. Intense Upconversion Luminescence of CaSc2 O4 :Ho(3+) /Yb(3+) from Large Absorption Cross Section and Energy-Transfer Rate of Yb(3.).

    PubMed

    Li, Jing; Zhang, Jiahua; Hao, Zhendong; Chen, Li; Zhang, Xia; Luo, Yongshi

    2015-05-18

    Concentration-optimized CaSc2 O4 :0.2 % Ho(3+) /10 % Yb(3+) shows stronger upconversion luminescence (UCL) than a typical concentration-optimized upconverting phosphor Y2 O3 :0.2 % Ho(3+) /10 %  b(3+) upon excitation with a 980 nm laser diode pump. The (5) F4 +(5) S2 →(5) I8 green UCL around 545 nm and (5) F5 →(5) I8 red UCL around 660 nm of Ho(3+) are enhanced by factors of 2.6 and 1.6, respectively. On analyzing the emission spectra and decay curves of Yb(3+) : (2) F5/2 →(2) F7/2 and Ho(3+) : (5) I6 →(5) I8 , respectively, in the two hosts, we reveal that Yb(3+) in CaSc2 O4 exhibits a larger absorption cross section at 980 nm and subsequent larger Yb(3+) : (2) F5/2 →Ho(3+) : (5) I6 energy-transfer coefficient (8.55×10(-17) cm(3) s(-1) ) compared to that (4.63×10(-17) cm(3) s(-1) ) in Y2 O3 , indicating that CaSc2 O4 :Ho(3+) /Yb(3+) is an excellent oxide upconverting material for achieving intense UCL. PMID:25721224

  10. Multicolour upconversion emission from Ho{sup 3+}-Tm{sup 3+}-Yb{sup 3+} codoped CaMoO{sub 4} phosphor

    SciTech Connect

    Dey, Riya; Rai, Vineet Kumar

    2015-05-15

    The Ho{sup 3+}-Tm{sup 3+}-Yb{sup 3+} codoped CaMoO4 phosphor powder has been synthesized by chemical coprecipitation technique. For the structural investigation the X-ray diffraction analysis has been done. Multicolour upconversion (UC) emission in the visible region from the prepared material has been observed under the 980 nm near infrared (NIR) excitation. The UC emission bands ∼ 474 nm (blue), ∼ 541 nm (green) and ∼ 661 nm (red) region have been assigned as {sup 1}G{sub 4}→{sup 3}H{sub 6} (Tm{sup 3+}), {sup 5}F{sub 4}{sup 5}S{sub 2}→{sup 5}I{sub 8} (Ho{sup 3+}) and {sup 5}F{sub 5}→{sup 5}I{sub 8} (Ho{sup 3+}) transitions respectively.

  11. Upconversion luminescence properties and color tunability of 12CaOṡ7Al2O3:Ho3+/Yb3+ single crystal

    NASA Astrophysics Data System (ADS)

    Qu, Yunfei; Qiu, Zhaozhong; Wang, Rui; Liu, Liang; Tao, Ye; Zhou, Jianjun

    2016-03-01

    Rear earth (RE) ions-doped 12CaOṡ7Al2O3 single crystal has been successfully prepared by Czochralski method. Under 980 nm excitation, a strong green upconversion emission at 548 nm and a weaker red upconversion emission at 662 nm were observed. The green upconversion emission is corresponding to the transition of 5F 4/5S2 →5I8 of Ho3+, and the red one is corresponding to the transition of 5F5 →5I8 of Ho3+. A much weaker NIR band at 762 nm is also observed, which corresponds to the 5F 4/5S2 →5I7 transition of Ho3+. The pump dependence and luminescence decay dynamics spectra show the green and red upconversion are populated by two-photon process, and the upconversion mechanisms are analyzed in detail. The color of the upconversion luminescence can be changed by simply adjusting the excitation power. RE ions-doped 12CaOṡ7Al2O3 single crystal with these properties is expected to have broad application prospects in solid-state multicolor display and instrument integration. RE ions-doped 12CaOṡ7Al2O3 single crystal has the ability to replace some traditional single crystals such as LiNbO3 in many applications.

  12. Studies on the new superconducting system (RE) Ba2Ca3Sr4Cu5Ox (RE=Gd, Ho & Dy)

    NASA Astrophysics Data System (ADS)

    Arumugam, S.

    1996-03-01

    Superconducting studies have been carried out in the new high TC (50-65K) system (RE)Ba2Ca3Sr4Cu5OX [(RE) 12345] with RE=Gd, Ho&Dy. The unit cell dimensions are of the order of a=5.44 °A, b=5.46°A and c=14.62°A. The data above the diamagnetic onset and below the upturn temperature due to ordering were analyzed to yield the effective magnetic moments (Peff) of the rare earth ions.

  13. Random strain effects in optical and EPR spectra of electron-nuclear excitations in CaWO4:Ho(3+) single crystals.

    PubMed

    Shakurov, G S; Chukalina, E P; Popova, M N; Malkin, B Z; Tkachuk, A M

    2014-12-01

    We study paramagnetic Ho(3+) centers in CaWO4, a promising material for applications in quantum electronics and quantum information devices. Oriented single crystals with nominal holmium concentrations 0.05, 0.5, and 1 at% were investigated at 4.2 K using EPR spectroscopy in the frequency range 37-850 GHz at temperatures 5-40 K and high-resolution optical transmission spectroscopy in the infrared and visible wave-length ranges. Along with the tetragonal Ho(3+) centers of the S4 point symmetry, four different types of low-symmetry centers were identified in the EPR spectra and their spectral parameters were determined. A well resolved hyperfine structure exhibiting holmium concentration dependent features was observed in optical spectra. Modeling of the spectra taking into account random lattice strains gave a possibility of reproducing satisfactorily the measured hyperfine structure of the EPR signals, in particular, at anticrossings of the electron-nuclear sublevels of the ground non-Kramers doublet, and the envelopes of the hyperfine structure of optical transitions. The widths of the probability distribution of random deformations related to the point lattice defects in the samples with different concentrations of the impurity Ho(3+) ions were estimated from a comparison of the simulated spectra with the experimental data. PMID:25315262

  14. Removal of rhodamine 6G dye contaminant by visible light driven immobilized Ca1-xLnxMnO3 (Ln = Sm, Ho; 0.1 ≤ x ≤ 0.4) photocatalysts

    NASA Astrophysics Data System (ADS)

    Barrocas, B.; Sério, S.; Rovisco, A.; Nunes, Y.; Jorge, M. E. Melo

    2016-01-01

    Visible-light-driven Ca1-xLnxMnO3 (Ln = Sm, Ho; 0.1 ≤ x ≤ 0.4) films were grown by RF-magnetron sputtering onto fused silica substrates. The effects of Ca2+ substitution for Ho3+ or Sm3+ in Ca1-xLnxMnO3 on the structural, morphological and photocatalytic properties for rhodamine 6G dye degradation under visible light irradiation were investigated. XRD showed a pure typical perovskite phase for all the prepared films, except for Ca0.9Ho0.1MnO3 and a decrease of the crystallite size with the increase of the amount of ion substituted. SEM and AFM revealed that the films surface is dense, with low roughness. UV-vis spectroscopy indicated for the two series band gaps in the range of 1.6-2.8 eV, being lower for the films containing holmium. The results showed that some Ca1-xHoxMnO3 and Ca1-xSmxMnO3 films present higher photocatalytic activity for Rh6G degradation in comparison with TiO2 films and for the same x value the Ho-films exhibited higher photocatalytic activity. For both films series the maximal degradation rate was obtained for x = 0.2; above this content the degradation percentage exhibits a decreasing trend with the increase of Ho or Sm substitution, except for x = 0.4 in the case of Ho system, which is observed again an increase in the degradation rate. The Rh6G photocatalytic degradation followed a pseudo first-order reaction kinetics. XRD and SEM of the used photocatalysts evidenced high photochemical stability.

  15. The magnetic properties of R in Pb 2Sr 2(R/Ca)Cu 3O 8 (R = HO and Er)

    NASA Astrophysics Data System (ADS)

    Soderholm, L.; Loong, C.-K.; Staub, U.; Skanthakumar, S.; Simon Xue, J.; Hammonds, J. P.; Greedan, J. E.; Maric, M.

    1995-02-01

    The electronic behavior of the rare-earth ion (R) in the Pb based superconductors Pb 2Sr 2(R 1- xCa x)Cu 3O 8, for R = Er ( x = 0, 0.5) and Ho ( x = 0), has been analyzed by inelastic neutron scattering. Sharp, well-defined transitions of magnetic origin have been observed for the parent R = Er and Ho ( x = 0) compounds. Peaks, determined to be of magnetic origin, have been assigned to crystal-field (CF) transitions within the Russell-Saunders ground multiplet. These results have been modeled using a crystal-field hamiltonian that includes intermediate-coupling and spherical-tensor techniques. The CF potential was determined for tetragonal symmetry. The calculated parameters are similar to those determined for similar R in the RBa 2Cu 3O 7 compounds. The results of the crystal-field analyses for the parent compounds are used to calculate the expected rare-earth contributions to the magnetic susceptibility, and compared to experimental data where available. In contrast to the data on the parent compounds, the spectra obtained from the superconductor Pb 2Sr 2Er 0.5Ca 0.5Cu 3O 8 show only very broad features. This broadening is attributed to chemical disorder rather than to an electronic effect.

  16. Hybrid Laser-Arc Welding of 10-mm-Thick Cast Martensitic Stainless Steel CA6NM: As-Welded Microstructure and Mechanical Properties

    NASA Astrophysics Data System (ADS)

    Mirakhorli, Fatemeh; Cao, Xinjin; Pham, Xuan-Tan; Wanjara, Priti; Fihey, Jean-Luc

    2016-07-01

    Cast CA6NM martensitic stainless steel plates, 10 mm in thickness, were welded using hybrid laser-arc welding. The effect of different welding speeds on the as-welded joint integrity was characterized in terms of the weld bead geometry, defects, microstructure, hardness, ultimate tensile strength, and impact energy. Significant defects such as porosity, root humping, underfill, and excessive penetration were observed at a low welding speed (0.5 m/min). However, the underfill depth and excessive penetration in the joints manufactured at welding speeds above 0.75 m/min met the specifications of ISO 12932. Characterization of the as-welded microstructure revealed untempered martensite and residual delta ferrite dispersed at prior-austenite grain boundaries in the fusion zone. In addition, four different heat-affected zones in the weldments were differentiated through hardness mapping and inference from the Fe-Cr-Ni ternary phase diagram. The tensile fracture occurred in the base metal for all the samples and fractographic analysis showed that the crack path is within the martensite matrix, along primary delta ferrite-martensite interfaces and within the primary delta ferrite. Additionally, Charpy impact testing demonstrated slightly higher fracture energy values and deeper dimples on the fracture surface of the welds manufactured at higher welding speeds due to grain refinement and/or lower porosity.

  17. Hybrid Laser-Arc Welding of 10-mm-Thick Cast Martensitic Stainless Steel CA6NM: As-Welded Microstructure and Mechanical Properties

    NASA Astrophysics Data System (ADS)

    Mirakhorli, Fatemeh; Cao, Xinjin; Pham, Xuan-Tan; Wanjara, Priti; Fihey, Jean-Luc

    2016-04-01

    Cast CA6NM martensitic stainless steel plates, 10 mm in thickness, were welded using hybrid laser-arc welding. The effect of different welding speeds on the as-welded joint integrity was characterized in terms of the weld bead geometry, defects, microstructure, hardness, ultimate tensile strength, and impact energy. Significant defects such as porosity, root humping, underfill, and excessive penetration were observed at a low welding speed (0.5 m/min). However, the underfill depth and excessive penetration in the joints manufactured at welding speeds above 0.75 m/min met the specifications of ISO 12932. Characterization of the as-welded microstructure revealed untempered martensite and residual delta ferrite dispersed at prior-austenite grain boundaries in the fusion zone. In addition, four different heat-affected zones in the weldments were differentiated through hardness mapping and inference from the Fe-Cr-Ni ternary phase diagram. The tensile fracture occurred in the base metal for all the samples and fractographic analysis showed that the crack path is within the martensite matrix, along primary delta ferrite-martensite interfaces and within the primary delta ferrite. Additionally, Charpy impact testing demonstrated slightly higher fracture energy values and deeper dimples on the fracture surface of the welds manufactured at higher welding speeds due to grain refinement and/or lower porosity.

  18. Spectroscopic investigation of 2.02 {mu}m emission in Ho{sup 3+}/Tm{sup 3+} codoped transparent glass ceramic containing CaF{sub 2} nanocrystals

    SciTech Connect

    Chen, Q. J.; Zhang, W. J.; Qian, Q.; Yang, Z. M.; Zhang, Q. Y.

    2010-05-15

    Tm{sup 3+} and Ho{sup 3+} codoped transparent glass ceramic (GC) containing CaF{sub 2} nanocrystals were fabricated by melt-quenching and subsequent thermal treatment. X-ray diffraction and transmission electron microscopy analysis confirmed the precipitation of CaF{sub 2} nanocrystals among the glass matrix. Energy-dispersive x-ray spectroscopy results evidenced the incorporation of Tm{sup 3+} and Ho{sup 3+} into the CaF{sub 2} nanocrystals. Judd-Ofelt parameters were calculated based on the absorption spectra, the smaller {Omega}{sub 2} and larger {Omega}{sub 6} imply that Tm{sup 3+} and Ho{sup 3+} ions has entered into a symmetrical ionic crystal field. 2.02 {mu}m emission spectral of the GC samples were recorded at room temperature with an excitation of 808 nm laser diode. The enhancement of the emission at 2.02 {mu}m in the GC samples could be attributed to more efficient cross relaxation process of Tm{sup 3+}:{sup 3}H{sub 4+}Tm{sup 3+}:{sup 3}H{sub 6}{yields}{sup 2}Tm{sup 3+}:{sup 3}H{sub 4}, and energy transfer from Tm{sup 3+} to Ho{sup 3+} benefited from the incorporation of rare earth ions into CaF{sub 2} nanocrystals.

  19. Preliminary Experiments and Determination of the Thermal Gradient in a 12.7 mm CaF2 Furnace Assembly, Humboldt State University Piston-Cylinder Laboratory

    NASA Astrophysics Data System (ADS)

    Schwab, B. E.

    2004-12-01

    A 12.7 mm piston-cylinder laboratory has been established at Humboldt State University. A series of double-thermocouple (DTC) experiments were performed to measure the thermal profile of the furnace assembly following the procedures of Pickering et al. (1998, Amer. Min.). Furnace assemblies consist of a 304 stainless base plug, CaF&_{2} sleeve, straight-walled graphite heater tube, crushable MgO inner parts, and lower graphite plug and ring which allow for extrusion of the graphite heater tube during shortening of the sleeve and MgO pieces. Careful measurement of pre- and post-run assembly parts indicate an average 30-35% shortening of the assembly. DTC results show a thermal peak that is displaced \\sim2.0 mm above the center of the effective furnace, defined as the length of inner MgO pieces post-run. This offset is in the same direction (upward, toward base plug), but slightly less than the offset described by Pickering et al. (1998). A secondary measure of the thermal profile using spinel growth via reaction between MgO and Al_{2}O_{3} assembly parts (e.g., Watson et al., 2002, CMP) is underway. A single partial melting experiment was performed at 1.0 GPa and 1330\\degC for 72 hours using intermediate peridotite starting material INT-A in a graphite-lined Pt capsule with vitreous carbon spheres as a melt sink. Phase compositions were determined by electron microprobe and mass balance calculations were made to determine melt fraction and mineral mode. Initial calculations yield glass:olivine:cpx:opx:spinel proportions of: 5.0:54.2:15.9:23.9:1.1. These preliminary results correspond well with previous work performed at the University of Oregon on the same starting material (Schwab and Johnston, 2001). The best match is with a 1315\\degC experiment (INT-A13) in terms of mode (6.9:53.7:13.4:25.0:1.0) and glass composition, indicating that the temperature of this initial experiment may be slightly cooler than the target temperature, however the results of this

  20. Production cross sections of elements near the N=126 shell in Ca48-induced reactions with Gd154,Tb159,Dy162, and Ho165 targets

    NASA Astrophysics Data System (ADS)

    Mayorov, D. A.; Werke, T. A.; Alfonso, M. C.; Bennett, M. E.; Folden, C. M.

    2014-08-01

    Excitation functions for shell-stabilized evaporation residues produced in Ca48-induced reactions with Gd154,Tb159,Dy162, and Ho165 targets have been measured in experiments performed at the Cyclotron Institute at Texas A&M University. The examined energy range predominantly covers the 3n and 4n evaporation channels with higher cross sections measured for the 4n products. The σ4n are nearly invariant within experimental uncertainty in reactions with Tb159,Dy162, and Ho165 with the maxima at 12.6 ± 1.9, 12.6 ± 1.7, and 9.4 ± 1.3 mb, respectively. For the reaction with Gd154, the maximum is slightly lower at 4.0 ± 0.6 mb. A simple model to describe the measured production cross sections was employed. Capture was estimated by using the "diffused barrier formula" from the "fusion by diffusion" model proposed by Świątecki et al. [Phys. Rev. C 71, 014602 (2005)]., 10.1103/PhysRevC.71.014602 The fusion probability was estimated by using a phenomenological expression presented by Siwek-Wilczyńska et al. [Int. J. Mod. Phys. E 17, 12 (2008)]., 10.1142/S0218301308009501 The survival probability was calculated according to the formula of Vandenbosch and Huizenga [Nuclear Fission (Academic, New York, 1973)], derived from transition-state theory. The best agreement is reached between calculation and experiment upon inclusion of collective effects in the calculation of the survival probability, shown previously to be important for production of weakly deformed nuclei. This, in turn, challenges the expectation that strong shell stabilization benefits the production cross section. The present data are compared with earlier studies on production of neutron-deficient nuclei in Ca-induced reactions with lanthanide targets.

  1. Large-scale QM/MM calculations of the CaMn4O5 cluster in the oxygen-evolving complex of photosystem II: Comparisons with EXAFS structures

    NASA Astrophysics Data System (ADS)

    Shoji, Mitsuo; Isobe, Hiroshi; Nakajima, Takahito; Yamaguchi, Kizashi

    2016-08-01

    Large-scale QM/MM calculations including hydrogen-bonding networks in the oxygen evolving complex (OEC) of photosystem II (PSII) were performed to elucidate the geometric structures of the CaMn4O5 cluster in the key catalytic states (Si (i = 0-3)). The optimized Mn-Mn, Ca-Mn and Mn-O distances by the large-scale QM/MM starting from the high-resolution XRD structure were consistent with those of the EXAFS experiments in the dark stable S1 state by the Berkeley and Berlin groups. The optimized geometrical parameters for other Si (i = 0, 2, 3) states were also consistent with those of EXAFS, indicating the importance of the large-scale QM/MM calculations for the PSII-OEC.

  2. K-MM radiative Auger effect in solid Ca, Ti and Cr targets after ionization with 0.7-1.5 MeV protons

    NASA Astrophysics Data System (ADS)

    Budnar, M.; Mühleisen, A.; Hribar, M.; Janžekovič, H.; Ravnikar, M.; Šmit, Ž.; Žitnik, M.

    1992-03-01

    Radiative Auger (RAE) X-ray spectra were measured for the first time on Ca, Cr, and Ti targets after ionization by 0.7-1.5 MeV protons. The energies of the RAE X-ray transitions were compared with the energies obtained from the Auger transitions. The RAE intensities relative to the diagram K β13 line were deduced and compared with the available data from X-ray fluorescence and electron capture ionization. The relative yields obtained for Ca, Ti, and Cr were (3.14 ± 0.47), (2.44 ± 0.37) and (2.91 ± 0.58)%, respectively.

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

    SciTech Connect

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

    2011-08-15

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

  4. The layered antimonides RELi3Sb2 (RE=Ce-Nd, Sm, Gd-Ho). Filled derivatives of the CaAl2Si2 structure type

    NASA Astrophysics Data System (ADS)

    Schäfer, Marion C.; Suen, Nian-Tzu; Raglione, Michaella; Bobev, Svilen

    2014-02-01

    Reported are the synthesis and the structural characterization of an extended family of rare-earth metal-lithium-antimonides with the formula RELi3Sb2 (RE=Ce-Nd, Sm, Gd-Ho). They crystallize in the trigonal space group P3barm1 (No. 164, Pearson symbol hP6) with a structure, best viewed as a filled derivative of the common CaAl2Si2 structure type (ternary variant of α-La2O3). Across the series, the lattice parameters monotonically decrease, following the lanthanide contraction. Temperature-dependent magnetic susceptibility measurements for CeLi3Sb2, PrLi3Sb2 and TbLi3Sb2 reveal paramagnetic behavior in the high temperature range, and the obtained effective moments are consistent with the expected ones for the free-ion RE3+ ground state. Possible ferromagnetic ordering for PrLi3Sb2 and antiferromagnetic ordering for TbLi3Sb2 are observed in the low temperature range (below 20 K). Tight-binding muffin-tin orbital electronic band structure calculations for LaLi3Sb2 are presented and discussed as well.

  5. Improved ferroelectric/piezoelectric properties and bright green/UC red emission in (Li,Ho)-doped CaBi4Ti4O15 multifunctional ceramics with excellent temperature stability and superior water-resistance performance.

    PubMed

    Xiao, Ping; Guo, Yongquan; Tian, Mijie; Zheng, Qiaoji; Jiang, Na; Wu, Xiaochun; Xia, Zhiguo; Lin, Dunmin

    2015-10-21

    Multifunctional materials based on rare earth ion doped ferro/piezoelectrics have attracted considerable attention in recent years. In this work, new lead-free multifunctional ceramics of Ca1-x(LiHo)x/2Bi4Ti4O15 were prepared by a conventional solid-state reaction method. The great multi-improvement in ferroelectricity/piezoelectricity, down/up-conversion luminescence and temperature stability of the multifunctional properties is induced by the partial substitution of (Li0.5Ho0.5)(2+) for Ca(2+) ions in CaBi4Ti4O15. All the ceramics possess a bismuth-layer structure, and the crystal structure of the ceramics is changed from a four layered bismuth-layer structure to a three-layered structure with the level of (Li0.5Ho0.5)(2+) increasing. The ceramic with x = 0.1 exhibits simultaneously, high resistivity (R = 4.51 × 10(11)Ω cm), good piezoelectricity (d33 = 10.2 pC N(-1)), high Curie temperature (TC = 814 °C), strong ferroelectricity (Pr = 9.03 μC cm(-2)) and enhanced luminescence. These behaviours are greatly associated with the contribution of (Li0.5Ho0.5)(2+) in the ceramics. Under the excitation of 451 nm light, the ceramic with x = 0.1 exhibits a strong green emission peak centered at 545 nm, corresponding to the transition of the (5)S2→(5)I8 level in Ho(3+) ions, while a strong red up-conversion emission band located at 660 nm is observed under the near-infrared excitation of 980 nm at room temperature, arising from the transition of (5)F5→(5)I8 levels in Ho(3+) ions. Surprisingly, the excellent temperature stability of ferroelectricity/piezoelectricity/luminescence and superior water-resistance behaviors of piezoelectricity/luminescence are also obtained in the ceramic with x = 0.1. Our study suggests that the present ceramics may have potential applications in advanced multifunctional devices at high temperature. PMID:26387782

  6. 2,3-Dimethoxy-2′-hydroxychalcone ameliorates TNF-α-induced ICAM-1 expression and subsequent monocyte adhesiveness via NF-kappaB inhibition and HO-1 induction in HaCaT cells

    PubMed Central

    Kim, Hyejin; Youn, Gi Soo; An, Soo Yeon; Kwon, Hyeok Yil; Choi, Soo Young; Park, Jinseu

    2016-01-01

    Up-regulation of adhesion molecules plays an important role in the infiltration of leukocytes into the skin during the development of various inflammatory skin diseases, such as atopic dermatitis. In this study, we investigated the modulatory effects of 2,3-dimethoxy-2′-hydroxychalcone (DMHC) on tumor necrosis factor (TNF)-α-induced intercellular adhesion molecule-1 (ICAM-1) expression and monocyte adhesiveness, as well as the molecular mechanisms underlying its action in the HaCaT human keratinocyte cell line. Pre-treating HaCaT cells with DMHC significantly suppressed TNF-α-induced ICAM-1 expression and subsequent monocyte adhesiveness. DMHC inhibited TNF-α-induced activation of NF-ᴋB. In addition, DMHC induced HO-1 expression as well as NRF2 activation. Furthermore, HO-1 knockdown using siRNA reversed the inhibitory effect of DMHC on TNF-α-induced ICAM-1 expression and adhesion of monocytes to keratinocytes. These results suggest that DMHC may inhibit TNF-α-induced ICAM-1 expression and adhesion of monocytes to keratinocytes by suppressing the signaling cascades leading to NF-ᴋB activation and inducing HO-1 expression in keratinocytes. [BMB Reports 2016; 49(1): 57-62] PMID:26277982

  7. Luminescence Properties of Self-Activated Mm(VO4)2 (M = Mg, Ca, Sr, and Ba) Phosphors Synthesized by Solid-State Reaction Method.

    PubMed

    Min, Xin; Huang, Zhaohui; Fang, Minghao; Liu, Yan'gai; Tang, Chao; Wu, Xiaowen

    2016-04-01

    In this paper, M3(VO4)2 (M = Mg, Ca, Sr, and Ba) self-activated phosphors were prepared by a solid-state reaction method at 1,000 °C for 5 h. The phase formation and micrographs were analyzed by X-ray diffraction and scanning electron microscopy. The Ca3(VO4)2 phosphor does not show any emission peaks under excitation with ultraviolet (UV) light. However, the M3(VO4)2 (M = Mg, Sr, and Ba) samples are effectively excited by UV light chips ranging from 200 nm to 400 nm and exhibit broad emission bands due to the charge transfer from the oxygen 2p orbital to the vacant 3d orbital of the vanadium in the VO4. The color of these phosphors changes from yellow to light blue via blue-green with increasing ionic radius from Mg to Sr to Ba. The luminescence lifetimes and quantum yield decrease with the increasing unit cell volume and V-V distance, in the order of Mg3(VO4)2 to Sr3(VO4)2 to Ba3(VO4)2. The emission intensity decreases with the increase of temperatures, but presents no color shift. This confirms that these self-activated M3(VO4)2 phosphors can be suggested as candidates of the single-phase phosphors for light using UV light emitting diodes (LEDs). PMID:27451689

  8. Effects of extracellular pH on receptor-mediated Ca2+ influx in A7r5 rat smooth muscle cells: involvement of two different types of channel.

    PubMed Central

    Iwasawa, K; Nakajima, T; Hazama, H; Goto, A; Shin, W S; Toyo-oka, T; Omata, M

    1997-01-01

    1. The effects of extracellular pH (pHo) on receptor (vasopressin or endothelin-1)-mediated Ca2- entry and Ca(2+)-permeable channels were investigated in aortic smooth muscle cells (A7r5) from rat embryonic thoracic aorta. Intracellular Ca2+ ([Ca2+]i) was measured using fura-2 AM and whole-cell voltage clamp techniques were employed. 2. Vasopressin and endothelin-1 (100 nM) in the presence of nicardipine (10 microM) evoked a sustained rise in [Ca2+]i due to calcium entry. Extracellular acidosis decreased receptor (vasopressin or endothelin-1)-mediated Ca2+ entry, while extracellular alkalosis potentiated it. 3. Depletion of intracellular Ca2+ stores with thapsigargin (1 microM) also evoked Ca2+ entry activated by emptying of intracellular Ca2+ stores (capacitative Ca2+ entry). Extracellular acidosis decreased this capacitative Ca2+ entry, while extracellular alkalosis potentiated it. 4. Under voltage-clamp conditions with Ca+ internal solution, vasopressin and endothelin-1 activated non-selective cation currents (ICAT). Ba2+ or Ca2+ were also charge carriers of ICAT. Reducing the pHo inhibited ICAT, while increasing pHo potentiated it in a reversible manner. 5. Intracellular pH (pHi) changes did not cause the same marked effects as pHo changes, and a high concentration of Hepes (50 mM) in the patch pipette did not inhibit the effects of pHo on ICAT. 6. Similar results were obtained when ICAT was activated by GTP gamma S (1 mM) applied through the patch pipette, even in the absence of agonists, probably because of direct activation of GTP-binding proteins coupled to the receptors. 7. In cells treated with thapsigargin, addition of Ca2+ to the bath solution induced Ca(2+)-dependent K+ currents activated by capacitative Ca2+ entry. However, no measurable ionic currents activated by capacitative Ca2+ entry (ICRAC) were observed under conditions with Cs+ internal solution and EGTA (5 mM), although vasopressin still activated ICAT. 8. These results suggest that the

  9. Structure, magnetism and transport of the perovskite manganites Ln {sub 0.5}Ca{sub 0.5}MnO{sub 3} (Ln=Ho, Er, Tm, Yb and Lu)

    SciTech Connect

    Yoshii, Kenji . E-mail: yoshiike@spring8.or.jp; Abe, Hideki; Ikeda, Naoshi

    2005-12-15

    It was found that the manganese perovskite oxides Ln {sub 0.5}Ca{sub 0.5}MnO{sub 3} (Ln=Ho, Er, Tm, Yb and Lu) have an orthorhombic structure (space group Pnma). The Mn-O-Mn angles were calculated to be {approx}148-150{sup o}, revealing an existence of a large crystallographic distortion in these oxides. Electrical resistivity measurements indicated both an insulating nature and a small magnetoresistance effect, both of which are owing to narrow bandwidths of the Mn-3d electrons arising from the crystallographic distortion. DC magnetization measurements showed the three characteristic temperatures, which could be assigned to charge-order, antiferromagnetism of Mn moments, and possible glassy states. All of these temperatures were decreased for the heavier Ln ions, which is explained in connection with both a difference of ionic radii of Ln {sup 3+} and Ca{sup 2+}, and a lowering of electron transfer. The charge-ordering transition was not clearly observed only for Lu{sub 0.5}Ca{sub 0.5}MnO{sub 3} containing the smallest lanthanide ion, plausibly due to a large randomness of magnetic interactions arising from the ionic radii difference of Lu{sup 3+} and Ca{sup 2+}. In addition, preliminary measurements of AC dielectric response suggested that these manganites belong to a so-called multiferroic system.

  10. 8mm/16mm Movie-Making.

    ERIC Educational Resources Information Center

    Provisor, Henry

    The materials, techniques, and attitudes needed to make professional-quality movies using 8mm., super 8mm., and 16mm. amateur equipment are covered in this guide to movie-making. The pros and cons are discussed of the various makes and models of cameras and lenses. Other topics discussed are: exposure and lighting, choosing film, camera speed and…

  11. The layered antimonides RELi{sub 3}Sb{sub 2} (RE=Ce–Nd, Sm, Gd–Ho). Filled derivatives of the CaAl{sub 2}Si{sub 2} structure type

    SciTech Connect

    Schäfer, Marion C.; Suen, Nian-Tzu; Raglione, Michaella; Bobev, Svilen

    2014-02-15

    Reported are the synthesis and the structural characterization of an extended family of rare-earth metal–lithium–antimonides with the formula RELi{sub 3}Sb{sub 2} (RE=Ce–Nd, Sm, Gd–Ho). They crystallize in the trigonal space group P3{sup ¯}m1 (No. 164, Pearson symbol hP6) with a structure, best viewed as a filled derivative of the common CaAl{sub 2}Si{sub 2} structure type (ternary variant of α-La{sub 2}O{sub 3}). Across the series, the lattice parameters monotonically decrease, following the lanthanide contraction. Temperature-dependent magnetic susceptibility measurements for CeLi{sub 3}Sb{sub 2}, PrLi{sub 3}Sb{sub 2} and TbLi{sub 3}Sb{sub 2} reveal paramagnetic behavior in the high temperature range, and the obtained effective moments are consistent with the expected ones for the free-ion RE{sup 3+} ground state. Possible ferromagnetic ordering for PrLi{sub 3}Sb{sub 2} and antiferromagnetic ordering for TbLi{sub 3}Sb{sub 2} are observed in the low temperature range (below 20 K). Tight-binding muffin-tin orbital electronic band structure calculations for LaLi{sub 3}Sb{sub 2} are presented and discussed as well. - Graphical abstract: The large family of rare-earth metal–lithium–antimonides with the formula RELi{sub 3}Sb{sub 2} (RE=Ce–Nd, Sm, Gd–Ho) crystallize in the trigonal space group P3{sup ¯}m1 (No. 164, Pearson symbol hP6) with a structure that is a filled derivative of the CaAl{sub 2}Si{sub 2} structure type (ternary variant of α-La{sub 2}O{sub 3}). Display Omitted - Highlights: • RELi{sub 3}Sb{sub 2} (RE=Ce–Nd, Sm, Gd–Ho) constitute an extended family of rare-earth metal–lithium–antimonides. • The layered structure is a filled derivative of the common CaAl{sub 2}Si{sub 2} structure type. • The valence electron count follows the Zintl–Klemm rules. • Electronic band structure calculations for LaLi{sub 3}Sb{sub 2} indicate small band-gap semiconducting behavior.

  12. Efficient, low threshold, cryogenic Ho:YAG laser.

    PubMed

    Ganija, Miftar; Simakov, Nikita; Hemming, Alexander; Haub, John; Veitch, Peter; Munch, Jesper

    2016-05-30

    We report the development of an efficient, liquid-nitrogen conduction cooled Ho:YAG slab laser with good beam quality. Detailed measurements resolving the structure of the 1900-1911 nm absorption band in Ho:YAG at 77 K are presented. Stress-free conduction cooled mounting of the Ho:YAG slab was demonstrated and the resulting laser operated with a large mode volume of 42 mm3, a slope efficiency of 75% and a threshold of 0.84 W. To our knowledge this corresponds to the lowest reported threshold intensity for a Ho:YAG laser. PMID:27410084

  13. mm-wave antenna

    NASA Astrophysics Data System (ADS)

    Muhs, H. P.

    1985-07-01

    The present low profile seeker front end's slotted waveguide antenna was primarily developed to investigate the feasibility of the application of standard manufacturing techniques to mm-wave hardware. A dual plane monopulse comparator was constructed to mate with the antenna via integrated packaging techniques. The comparator was fabricated by CAD/CAM milling operations.

  14. Controlled synthesis and luminescence properties of Ca0.5Y1-x(MoO4)2:xRE3+ (RE = Eu, Pr, Sm, Tb, Dy, Yb/Er, Yb/Tm, and Yb/Ho) phosphors by hydrothermal method versus pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Mahalingam, Venkatakrishnan; Thirumalai, Jagannathan; Krishnan, Rajagopalan; Chandramohan, Rathinam

    2016-01-01

    Herein, we report on rare-earth (RE) activated Ca0.5Y1-x(MoO4)2:xRE3+ (RE = Eu, Pr, Sm, Tb, Dy, Yb/Er, Yb/Ho, and Yb/Tm) phosphors synthesized using a surfactant-mediated hydrothermal route. Timedependent experiments were performed, and the morphological evolution of the phosphors was studied. From prepared powder samples of Ca0.5Y1-x(MoO4)2:xRE3+ (RE = Eu and Yb/Er), nano-sized thin phosphor films were grown using pulsed laser deposition (PLD). The surface topography of the as-grown thin phosphor films was analyzed. The asprepared phosphors were characterized by structural and optical studies. The powder phosphor exhibited bi pyramid-like micro-architectures. Structural studies indicated that Ca0.5Y1-x(MoO4)2 possesses the scheelite tetragonal crystal structure. The down-conversion luminescence of Ca0.5Y1-x(MoO4)2:xRE3+ (RE = Eu, Pr, Sm, Tb, and Dy) as powder phosphors and Eu3+ doped Ca0.5Y1-x(MoO4)2 thin phosphor film were studied. Upon irradiation with a 980 nm laser, the Ca0.5Y1-x(MoO4)2: xRE3+ (RE = Yb/Er, Yb/Ho, and Yb/Tm) powder phosphors and Ca0.5Y1-x(MoO4)2:xRE3+ (RE = Yb/Er) thin phosphor film showed intense up-converted visible emissions in green, yellow, and blue regions. The fluorescence decay time and color co-ordinates were determined for all synthesized phosphors. From the obtained results, the prepared powder and thin film phosphors are suggested to be suitable candidates for display and electro-luminescence applications. [Figure not available: see fulltext.

  15. Building 904, oblique view to northeast, 210mm lens Travis ...

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

    Building 904, oblique view to northeast, 210mm lens - Travis Air Force Base, Base Spares Warehouse No. 1, Dixon Avenue & W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  16. Building 909, oblique view to southeast, 135 mm lens. Building ...

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

    Building 909, oblique view to southeast, 135 mm lens. Building 908 at extreme right for context. - Travis Air Force Base, Handling Crew Building, North of W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  17. Building 904, oblique view to southeast, 135 mm lens. ...

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

    Building 904, oblique view to southeast, 135 mm lens. - Travis Air Force Base, Base Spares Warehouse No. 1, Dixon Avenue & W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  18. Building 904, oblique view to northwest, 135 mm lens ...

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

    Building 904, oblique view to northwest, 135 mm lens - Travis Air Force Base, Base Spares Warehouse No. 1, Dixon Avenue & W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  19. Building 1204, oblique view to east, 90 mm lens. ...

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

    Building 1204, oblique view to east, 90 mm lens. - Travis Air Force Base, Squadron Operations & Readiness Crew Facility, W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  20. Building 931, oblique view to southeast, 135 mm lens. ...

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

    Building 931, oblique view to southeast, 135 mm lens. - Travis Air Force Base, Central Battery Charging Building, North of W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  1. Building 1204, oblique view to west, 135 mm lens. ...

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

    Building 1204, oblique view to west, 135 mm lens. - Travis Air Force Base, Squadron Operations & Readiness Crew Facility, W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  2. Building 931, oblique view to northwest, 210 mm lens. ...

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

    Building 931, oblique view to northwest, 210 mm lens. - Travis Air Force Base, Central Battery Charging Building, North of W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  3. Building 932, oblique view to northwest, 90 mm lens. Building ...

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

    Building 932, oblique view to northwest, 90 mm lens. Building 933-935 at extreme left. - Travis Air Force Base, Nuclear Weapons Assembly Plant 5, W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  4. Quantification of the response of rat medullary raphe neurones to independent changes in pHo and PCO2

    PubMed Central

    Wang, Wengang; Bradley, Stefania Risso; Richerson, George B

    2002-01-01

    The medullary raphe nuclei contain putative central respiratory chemoreceptor neurones that are highly sensitive to acidosis. To define the primary stimulus for chemosensitivity in these neurones, the response to hypercapnic acidosis was quantified and compared with the response to independent changes in PCO2 and extracellular pH (pHo). Neurones from the ventromedial medulla of neonatal rats (P0-P2) were dissociated and maintained in tissue culture for long enough to develop a mature response (up to 70 days). Perforated patch clamp recordings were used to record membrane potential and firing rate while changes were made in pHo, PCO2 and/or [NaHCO3]o from baseline values of 7.4, 5 % and 26 mm, respectively. Hypercapnic acidosis (PCO2 9 %; pHo 7.17) induced an increase in firing rate to 285 % of control in one subset of neurones (‘stimulated neurones’) and induced a decrease in firing rate to 21 % of control in a different subset of neurones (‘inhibited neurones’). Isocapnic acidosis (pHo 7.16; [NaHCO3]o 15 mm) induced an increase in firing rate of stimulated neurones to 309 % of control, and a decrease in firing rate of inhibited neurones to 38 % of control. In a different group of neurones, isohydric hypercapnia (9 % PCO2; [NaHCO3]o 40 mm) induced an increase in firing rate of stimulated neurones by the same amount (to 384 % of control) as in response to hypercapnic acidosis (to 327 % of control). Inhibited neurones also responded to isohydric hypercapnia in the same way as they did to hypercapnic acidosis. In Hepes-buffered solution, both types of neurone responded to changes in pHo in the same way as they responded to changes in pHo in bicarbonate-buffered Ringer solution. It has previously been shown that all acidosis-stimulated neurones in the medullary raphe are immunoreactive for tryptophan hydroxylase (TpOH-ir). Here it was found that TpOH-ir neurones in the medullary raphe were immunoreactive for carbonic anhydrase type II and type IV (CA II and CA

  5. High-spin yrast structure of {sup 159}Ho

    SciTech Connect

    Ollier, J.; Simpson, J.; Riley, M. A.; Wang, X.; Aguilar, A.; Teal, C.; Paul, E. S.; Nolan, P. J.; Petri, M.; Rigby, S. V.; Thomson, J.; Unsworth, C.; Carpenter, M. P.; Janssens, R. V. F.; Lauritsen, T.; Zhu, S.; Darby, I. G.; Hartley, D. J.; Kondev, F. G.

    2011-08-15

    An investigation of the yrast structure of the odd-Z {sup 159}Ho nucleus to high spin has been performed. The {sup 159}Ho nucleus was populated by the reaction {sup 116}Cd({sup 48}Ca,p4n{gamma}) at a beam energy of 215 MeV, and resulting {gamma} decays were detected by the Gammasphere spectrometer. The h{sub 11/2} yrast band has been significantly extended up to I{sup {pi}=}75/2{sup -} (tentatively 79/2{sup -}). A lower frequency limit for the second (h{sub 11/2}){sup 2} proton alignment was extracted consistent with the systematics of this alignment frequency, indicating an increased deformation with neutron number in the Ho isotopes. The energy-level splitting between the signature partners in the h{sub 11/2} structures of the Ho isotopes and the neighboring N=92 isotones is discussed.

  6. Primeval galaxies in the sub-mm and mm

    NASA Technical Reports Server (NTRS)

    Bond, J. Richard; Myers, Steven T.

    1993-01-01

    Although the results of COBE's FIRAS experiment 1 constrain the deviation in energy from the CMB blackbody in the 500-5000 micron range to be delta E/E, sub cmb less than 0.005, primeval galaxies can still lead to a brilliant sub-mm sky of non-Gaussian sources that are detectable at 10 inch resolution from planned arrays such as SCUBA on the James Clerk Maxwell Telescope and, quite plausibly, at sub-arcsecond resolution in planned mm and sub-mm interferometers. Here, we apply our hierarchical peaks method to a CDM model to construct sub-mm and mm maps of bursting PG's appropriate for these instruments with minimum contours chosen to correspond to realistic observational parameters for them and which pass the FIRAS limits.

  7. OpenMM accelerated MMTK

    NASA Astrophysics Data System (ADS)

    Bishop, Kevin P.; Constable, Steve; Faruk, Nabil F.; Roy, Pierre-Nicholas

    2015-06-01

    In this work, we provide an interface developed to link the Molecular Modelling toolkit (MMTK) with OpenMM in order to take advantage of the fast evaluation techniques of OpenMM. This interface allows MMTK scripts using the Langevin dynamics integrator, for both classical and path integral simulations, to be executed on a variety of hardware including graphical processing units via OpenMM. The interface has been developed using Python and Cython to take advantage of the high level abstraction thanks to the MMTK and OpenMM software packages. We have tested the interface on a number of systems to observe which systems benefit most from the acceleration libraries of OpenMM.

  8. SSC 40 mm cable results and 50 mm design discussions

    SciTech Connect

    Christopherson, D.; Capone, D.; Hannaford, R.; Remsbottom, R.; Jayakumar, R.; Snitchler, G. ); Scanlan, R.; Royet, J. )

    1990-09-01

    A summary of the cable produced for the 1990 40 mm Dipole Program is presented. The cable design parameters for the 50 mm Dipole Program are discussed, as well as portions of the SSC specification draft. Considerations leading to the final cable configuration and the results of preliminary trials are included. The first iteration of a strand mapping program to automate cable strand maps is introduced. 7 refs., 2 figs., 1 tab.

  9. 5. East portal of Tunnel 26, view to southwest, 135mm ...

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

    5. East portal of Tunnel 26, view to southwest, 135mm lens. Tunnel 25 (HAER CA-201) is visible in the distance. - Central Pacific Transcontinental Railroad, Tunnel No. 26, Milepost 133.29, Applegate, Placer County, CA

  10. HOED: Hypermedia Online Educational Database.

    ERIC Educational Resources Information Center

    Duval, E.; Olivie, H.

    This paper presents HOED, a distributed hypermedia client-server system for educational resources. The aim of HOED is to provide a library facility for hyperdocuments that is accessible via the world wide web. Its main application domain is education. The HOED database not only holds the educational resources themselves, but also data describing…

  11. Minfong Ho: Politics in Prose

    ERIC Educational Resources Information Center

    Wiggins, Joy L.

    2006-01-01

    In this article, the author interviews Minfong Ho, an award-winning Thai writer of children's and young adult novels. Ho was born in Burma to Chinese parents in 1951, raised in Singapore and Thailand, educated in Bangkok, Taiwan, and at Cornell University in New York. Ho's first novel, "Sing to the Dawn," won first prize from the Council of…

  12. The GBT 4mm Receiver

    NASA Astrophysics Data System (ADS)

    Frayer, David T.; White, S.; Watts, G.; Stennes, M.; Maddalena, R. J.; Simon, R.; Pospieszalski, M.; Bryerton, E.

    2013-01-01

    The new 4mm receiver (67--93 GHz) for the Robert C. Byrd Green Bank Telescope (GBT) was built to take advantage of the improved surface accuracy of the dish. The low frequency end of the 3mm atmospheric window is not available with ALMA (<84 GHz), and the sensitivity of the GBT is better than any other facility within this band. We discuss the design and performance of this new receiver for the GBT, and highlight the science opportunities available with the instrument. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

  13. Tropospheric HO determination by FAGE

    NASA Astrophysics Data System (ADS)

    Hard, T. M.; Obrien, R. J.; Chan, C. Y.; Mehrabzadeh, A. A.

    1986-12-01

    In the detection of tropospheric HO by laser excited fluorescence, and alternative air-sampling method, named FAGE (Fluorescence Assay with Gas Expansion) was introduced. Here the air is expanded through a nozzle prior to excitation, in order to improve the ratio of the HO signal to the scattered, fluorescent, and photolytic backgrounds. The improvement comes from the differing pressure dependence of the intensities of these four terms, as well as the distinguishability of their temporal waveforms at low pressures when excited by a pulsed laser. HO has been excited by a YAG/dye laser. Other lasers and pumping paths may perform as well or better in this method. With FAGE, chemical modulation of the HO signal was achieved by hydrocarbon addition to the nozzle flow, converting photolytic HO from an interference to a background. Chemical calibration of the instrumental response to external HO was also achieved, by hydrocarbon decay, at HO concentrations within the ambient range.

  14. Apollo 12 photography 70 mm, 16 mm, and 35 mm frame index

    NASA Technical Reports Server (NTRS)

    1970-01-01

    For each 70-mm frame, the index presents information on: (1) the focal length of the camera, (2) the photo scale at the principal point of the frame, (3) the selenographic coordinates at the principal point of the frame, (4) the percentage of forward overlap of the frame, (5) the sun angle (medium, low, high), (6) the quality of the photography, (7) the approximate tilt (minimum and maximum) of the camera, and (8) the direction of tilt. A brief description of each frame is also included. The index to the 16-mm sequence photography includes information concerning the approximate surface coverage of the photographic sequence and a brief description of the principal features shown. A column of remarks is included to indicate: (1) if the sequence is plotted on the photographic index map and (2) the quality of the photography. The pictures taken using the lunar surface closeup stereoscopic camera (35 mm) are also described in this same index format.

  15. Variable Selection using MM Algorithms

    PubMed Central

    Hunter, David R.; Li, Runze

    2009-01-01

    Variable selection is fundamental to high-dimensional statistical modeling. Many variable selection techniques may be implemented by maximum penalized likelihood using various penalty functions. Optimizing the penalized likelihood function is often challenging because it may be nondifferentiable and/or nonconcave. This article proposes a new class of algorithms for finding a maximizer of the penalized likelihood for a broad class of penalty functions. These algorithms operate by perturbing the penalty function slightly to render it differentiable, then optimizing this differentiable function using a minorize-maximize (MM) algorithm. MM algorithms are useful extensions of the well-known class of EM algorithms, a fact that allows us to analyze the local and global convergence of the proposed algorithm using some of the techniques employed for EM algorithms. In particular, we prove that when our MM algorithms converge, they must converge to a desirable point; we also discuss conditions under which this convergence may be guaranteed. We exploit the Newton-Raphson-like aspect of these algorithms to propose a sandwich estimator for the standard errors of the estimators. Our method performs well in numerical tests. PMID:19458786

  16. Credit USAF, ca. 1945. Original housed in the Photograph Files, ...

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

    Credit USAF, ca. 1945. Original housed in the Photograph Files, AFFTC/HO, Edwards AFB, California. Early view of the Control Tower (designated T-65, Building 4500) fitted out with radio antennae. Structure at base of tower was T42 (later Building 4503), Flight Operations - Edwards Air Force Base, North Base, Radio & Control Tower T-65, Northeast of A Street, Boron, Kern County, CA

  17. Credit USAF, ca. 1943. Original housed in the Photograph Files, ...

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

    Credit USAF, ca. 1943. Original housed in the Photograph Files, AFFTC/HO, Edwards AFB, California. Historic view of finished swimming pool, with fence and lifeguard station. View looks west - Edwards Air Force Base, North Base, Swimming Pool, Second Street, Boron, Kern County, CA

  18. Spectral and lasing characteristics of 1% Ho:YAG ceramics under intracavity pumping

    SciTech Connect

    Bagayev, S N; Vatnik, S M; Vedin, I A; Kurbatov, P F; Osipov, V V; Shitov, V A; Maksimov, R N; Luk'yashin, K E; Pavlyuk, A A

    2015-01-31

    High-transparency 1% Ho:YAG ceramics with the transmission coefficient of 82% in the IR range at the sample thickness of 1 mm are synthesised from a mixture of the Ho:Y{sub 2}O{sub 3} and Al{sub 2}O{sub 3} nanopowders obtained by the laser method. Results of investigations of spectral and lasing characteristics of 1 % Ho:YAG ceramics under intracavity pumping by radiation of a 5% Tm:KLuW disk element are presented. Based on spectral intensity analysis of generation in the 1.8 – 2.1 mm range and on cavity parameters, the estimated lasing slope efficiency for 1% Ho:YAG ceramics is about 40%. (lasers)

  19. Solar-pumped Er,Tm,Ho:YAG laser

    SciTech Connect

    Benmair, R.M.J.; Kagan, J.; Kalisky, Y.; Noter, Y.; Oron, M.; Shimony, Y.; Yogev, A. )

    1990-01-01

    Direct solar illumination was used to pump a 5-mm-diameter 62-mm exposed-length rod of Er,Tm,Ho:YAG to achieve a quasi-cw lasing of the Ho ion at an average power of 12 W. The solar radiation was chopped at a 20% duty cycle to avoid overloading of the cooling system. The peak power output was more than 65 W during the chopper's open times. The slope efficiency is 3.8%, and the threshold input energy is approximately 100 W. The laser was operated for long times (up to hours) while maintaining its performance. This is, to our knowledge, the first directly solar-pumped laser operating at 77 K.

  20. HO:LULF and HO:LULF Laser Materials

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P. (Inventor); Morrison, Clyde A. (Inventor); Filer, Elizabeth D. (Inventor); Jani, Mahendra G. (Inventor); Murray, Keith E. (Inventor); Lockard, George E. (Inventor)

    1998-01-01

    A laser host material LULF (LuLiF4) is doped with holmium (Ho) and thulium (Tm) to produce a new laser material that is capable of laser light production in the vicinity of 2 microns. The material provides an advantage in efficiency over conventional Ho lasers because the LULF host material allows for decreased threshold and upconversion over such hosts as YAG and YLF. The addition of Tm allows for pumping by commonly available GaAlAs laser diodes. For use with flashlamp pumping, erbium (Er) may be added as an additional dopant. For further upconversion reduction, the Tm can be eliminated and the Ho can be directly pumped.

  1. Apollo 12 70 mm photographic catalog

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Proof prints of the 70-mm photography are presented, sorted by magazine and frame number. The 28 lunar surface panorama mosaics and a listing of the mosaics are included. The catalog is designed to be used in conjunction with the "Apollo 12 Photography: 70-mm, 16-mm, and 35-mm Frame Index', which makes it possible to locate the area covered by each frame.

  2. Investigation on the structure and upconversion fluorescence of Yb3+/Ho3+ co-doped fluorapatite crystals for potential biomedical applications

    PubMed Central

    Li, Xiyu; Zhu, Jingxian; Man, Zhentao; Ao, Yingfang; Chen, Haifeng

    2014-01-01

    Rare-earth Yb3+ and Ho3+ co-doped fluorapatite (FA:Yb3+/Ho3+) crystals were prepared by hydrothermal synthesis, and their structure, upconversion properties, cell proliferation and imaging were investigated. The synthesized crystals, with a size of 16 by 286 nm, have a hexagonal crystal structure of classic FA and a Ca/Yb/Ho molar ratio of 100/16/2.1. Several reasonable Yb3+/Ho3+ -embedding lattice models along the fluorine channel of the FA crystal cell are proposed for the first time, such as models for (Ca7YbHo©)(PO4)6F2 and (Ca6YbHoNa2)(PO4)6F2. The activated FA:Yb3+/Ho3+ crystals were found to exhibit distinct upconversion fluorescence. The 543- and 654-nm signals in the emission spectra could be assigned, respectively, to the 5F4 (5S2) - 5I8 and 5F5 - 5I8 transitions of holmium via 980-nm near-infrared excitation and the energy transfer of ytterbium. After the surfaces were grafted with hydrophilic dextran, the crystals displayed clear fluorescent cell imaging. Thus, the prepared novel FA:Yb3+/Ho3+ upconversion fluorescent crystals have potential applications in the biomedical field. PMID:24658285

  3. Investigation on the structure and upconversion fluorescence of Yb3+/Ho3+ co-doped fluorapatite crystals for potential biomedical applications

    NASA Astrophysics Data System (ADS)

    Li, Xiyu; Zhu, Jingxian; Man, Zhentao; Ao, Yingfang; Chen, Haifeng

    2014-03-01

    Rare-earth Yb3+ and Ho3+ co-doped fluorapatite (FA:Yb3+/Ho3+) crystals were prepared by hydrothermal synthesis, and their structure, upconversion properties, cell proliferation and imaging were investigated. The synthesized crystals, with a size of 16 by 286 nm, have a hexagonal crystal structure of classic FA and a Ca/Yb/Ho molar ratio of 100/16/2.1. Several reasonable Yb3+/Ho3+ -embedding lattice models along the fluorine channel of the FA crystal cell are proposed for the first time, such as models for (Ca7YbHo©)(PO4)6F2 and (Ca6YbHoNa2)(PO4)6F2. The activated FA:Yb3+/Ho3+ crystals were found to exhibit distinct upconversion fluorescence. The 543- and 654-nm signals in the emission spectra could be assigned, respectively, to the 5F4 (5S2) - 5I8 and 5F5 - 5I8 transitions of holmium via 980-nm near-infrared excitation and the energy transfer of ytterbium. After the surfaces were grafted with hydrophilic dextran, the crystals displayed clear fluorescent cell imaging. Thus, the prepared novel FA:Yb3+/Ho3+ upconversion fluorescent crystals have potential applications in the biomedical field.

  4. Investigation on the structure and upconversion fluorescence of Yb³⁺/Ho³⁺ co-doped fluorapatite crystals for potential biomedical applications.

    PubMed

    Li, Xiyu; Zhu, Jingxian; Man, Zhentao; Ao, Yingfang; Chen, Haifeng

    2014-01-01

    Rare-earth Yb(3+) and Ho(3+) co-doped fluorapatite (FA:Yb(3+)/Ho(3+)) crystals were prepared by hydrothermal synthesis, and their structure, upconversion properties, cell proliferation and imaging were investigated. The synthesized crystals, with a size of 16 by 286 nm, have a hexagonal crystal structure of classic FA and a Ca/Yb/Ho molar ratio of 100/16/2.1. Several reasonable Yb(3+)/Ho(3+) -embedding lattice models along the fluorine channel of the FA crystal cell are proposed for the first time, such as models for (Ca7YbHo©)(PO4)6F2 and (Ca6YbHoNa2)(PO4)6F2. The activated FA:Yb(3+)/Ho(3+) crystals were found to exhibit distinct upconversion fluorescence. The 543- and 654-nm signals in the emission spectra could be assigned, respectively, to the (5)F4 ((5)S2) - (5)I8 and (5)F5 - (5)I8 transitions of holmium via 980-nm near-infrared excitation and the energy transfer of ytterbium. After the surfaces were grafted with hydrophilic dextran, the crystals displayed clear fluorescent cell imaging. Thus, the prepared novel FA:Yb(3+)/Ho(3+) upconversion fluorescent crystals have potential applications in the biomedical field. PMID:24658285

  5. P8 deficiency increases cellular ROS and induces HO-1.

    PubMed

    Weis, Sebastian; Bielow, Tobias; Sommerer, Ines; Iovanna, Juan; Malicet, Cédric; Mössner, Joachim; Hoffmeister, Albrecht

    2015-01-01

    The gene p8 encodes for a small cytoprotective protein with no apparent enzymatic activity being proposed to act as co-transcription factor whose expression is increased during inflammation. Recent data from astrocytes demonstrates that p8 suppression leads to induction of heme oxygenase 1 (HO-1). Here, we assessed the cross-talk between p8 and HO-1 in mouse embryonic fibroblasts (MEF) observing an increased expression of HO-1 in p8-deficient (p8(-/-)) MEFs in non-treated and treated conditions. This effect was independent of the cell cycle. Our findings revealed that generation of reactive oxygen species (ROS) was higher in p8(-/-) MEFs. Mitochondria and NADPH oxidases were not the origin of ROS. This observation was not restricted to MEF as suppression of p8 gene transcription in MiaPaCa-2 cells also led to increased intracellular ROS. Additionally, p8 deficiency did not affect the Rac1 dependant NADPH oxidase complex. Our data shows that p8 deficiency increases ROS and subsequently the expression of anti-oxidative enzymes, such as HO-1, suggesting an involvement in the anti-oxidative defense. Moreover, we suggest that the severity of AP observed in p8(-/-) mice is induced by an impaired anti oxidative capacity of the pancreas, which is caused by increased generation of ROS. PMID:25475530

  6. {sup 163}Ho based experiments

    SciTech Connect

    Gastaldo, Loredana

    2015-07-15

    The analysis of the endpoint region of the calorimetrically measured {sup 163}Ho electron capture spectrum is a very promising way to determine the mass of the electron neutrino. The achievable sensitivity of {sup 163}Ho-based experiments and the experimental challenges will be presented. Three large collaborations aim at developing large scale experiments able to reach sub-eV sensitivity. Presently pilot experiments are performed to demonstrate the possibility to calorimetrically measure high precision and high statistics {sup 163}Ho spectra. The different approaches as well as the state of the art of the experimental efforts for the three collaborations will be discussed.

  7. 19. Southeast end room; view to southeast, 65mm lens plus ...

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

    19. Southeast end room; view to southeast, 65mm lens plus electronic flash illumination. Note extent of failure; figure for scale. - Benicia Arsenal, Powder Magazine No. 5, Junction of Interstate Highways 680 & 780, Benicia, Solano County, CA

  8. 7. Detail, east portal of Tunnel 34/Snowshed 33, 135mm lens. ...

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

    7. Detail, east portal of Tunnel 34/Snowshed 33, 135mm lens. Tall signal mast necessary in order to be seen above winter snows. - Central Pacific Transcontinental Railroad, Tunnel No. 41, Milepost 193.3, Donner, Placer County, CA

  9. 18. Southeast end room; view to northeast, 65mm lens plus ...

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

    18. Southeast end room; view to northeast, 65mm lens plus electronic flash illumination. Failed south wall at right. - Benicia Arsenal, Powder Magazine No. 5, Junction of Interstate Highways 680 & 780, Benicia, Solano County, CA

  10. 17. Oblique view, typical room; view to south, 65mm lens ...

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

    17. Oblique view, typical room; view to south, 65mm lens plus electronic flash illumination. - Benicia Arsenal, Powder Magazine No. 5, Junction of Interstate Highways 680 & 780, Benicia, Solano County, CA

  11. 16. Oblique view, typical room; view to north, 65mm lens ...

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

    16. Oblique view, typical room; view to north, 65mm lens plus electronic flash illumination. - Benicia Arsenal, Powder Magazine No. 5, Junction of Interstate Highways 680 & 780, Benicia, Solano County, CA

  12. Compact Ho:YLF Laser

    NASA Technical Reports Server (NTRS)

    Hemmati, H.

    1988-01-01

    Longitudinal pumping by laser diodes increases efficiency. Improved holmium:yttrium lithium fluoride laser radiates as much as 56 mW of power at wavelength of 2.1 micrometer. New Ho:YLF laser more compact and efficient than older, more powerful devices of this type. Compact, efficient Ho:YLF laser based on recent successes in use of diode lasers to pump other types of solid-state lasers.

  13. Credit USAF. Original housed in the Photograph Files, AFFTC/HO, Edwards ...

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

    Credit USAF. Original housed in the Photograph Files, AFFTC/HO, Edwards AFB, California. View of Motor Repair Shop (originally T-16), probably shortly after completion in 1943 - Edwards Air Force Base, North Base, Motor Repair Shop T-16, Third & C Streets, Boron, Kern County, CA

  14. 2. Credit USAF, 1943. Original housed in the AFFTC/HO, Edwards ...

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

    2. Credit USAF, 1943. Original housed in the AFFTC/HO, Edwards AFB, California. View looks north northwest at south and east facades of hangar as it nears completion. - Edwards Air Force Base, North Base, Hangar No. 1, First & B Streets, Boron, Kern County, CA

  15. 5. Credit USAF, ca. 1942. Original housed in the Photograph ...

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

    5. Credit USAF, ca. 1942. Original housed in the Photograph Files, AFFTC/HO, Edwards AFB, California. View of Bell Aircraft XP-59A Airacomet in flight. This was the United States military's first jet propelled aircraft which was extensively flight tested in secrecy at the Muroc Flight Test Base (North Base). - Edwards Air Force Base, North Base, North Base Road, Boron, Kern County, CA

  16. 9. Credit USAF, ca. 1955. Original housed in the Photograph ...

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

    9. Credit USAF, ca. 1955. Original housed in the Photograph Files, AFFTC/HO, Edwards AFB, California. View of Lockheed XVF-1 Pogo, an experimental vertical take-off and landing aircraft at North Base. Photograph was taken on the apron between buildings 4401 and 4402, looking north northeast towards back of Building 4402 and officers' quarters (T-15) beyond. - Edwards Air Force Base, North Base, North Base Road, Boron, Kern County, CA

  17. Topics in Ho Morphophonology and Morphosyntax

    ERIC Educational Resources Information Center

    Pucilowski, Anna

    2013-01-01

    Ho, an under-documented North Munda language of India, is known for its complex verb forms. This dissertation focuses on analysis of several features of those complex verbs, using data from original fieldwork undertaken by the author. By way of background, an analysis of the phonetics, phonology and morphophonology of Ho is first presented. Ho has…

  18. Modification of Caffeic Acid with Pyrrolidine Enhances Antioxidant Ability by Activating AKT/HO-1 Pathway in Heart

    PubMed Central

    Ku, Hui-Chun; Lee, Shih-Yi; Yang, Kai-Chien; Kuo, Yueh-Hsiung; Su, Ming-Jai

    2016-01-01

    Overproduction of free radicals during ischemia/reperfusion (I/R) injury leads to an interest in using antioxidant therapy. Activating an endogenous antioxidant signaling pathway is more important due to the fact that the free radical scavenging behavior in vitro does not always correlate with a cytoprotection effect in vivo. Caffeic acid (CA), an antioxidant, is a major phenolic constituent in nature. Pyrrolidinyl caffeamide (PLCA), a derivative of CA, was compared with CA for their antioxidant and cytoprotective effects. Our results indicate that CA and PLCA exert the same ability to scavenge DPPH in vitro. In response to myocardial I/R stress, PLCA was shown to attenuate lipid peroxydation and troponin release more than CA. These responses were accompanied with a prominent elevation in AKT and HO-1 expression and a preservation of mnSOD expression and catalase activity. PLCA also improved cell viability and alleviated the intracellular ROS level more than CA in cardiomyocytes exposed to H2O2. When inhibiting the AKT or HO-1 pathways, PLCA lost its ability to recover mnSOD expression and catalase activity to counteract with oxidative stress, suggesting AKT/HO-1 pathway activation by PLCA plays an important role. In addition, inhibition of AKT signaling further abolished HO-1 activity, while inhibition of HO-1 signaling attenuated AKT expression, indicating cross-talk between the AKT and HO-1 pathways. These protective effects may contribute to the cardiac function improvement by PLCA. These findings provide new insight into therapeutic approaches using a modified natural compound against oxidative stress from myocardial injuries. PMID:26845693

  19. Modification of Caffeic Acid with Pyrrolidine Enhances Antioxidant Ability by Activating AKT/HO-1 Pathway in Heart.

    PubMed

    Ku, Hui-Chun; Lee, Shih-Yi; Yang, Kai-Chien; Kuo, Yueh-Hsiung; Su, Ming-Jai

    2016-01-01

    Overproduction of free radicals during ischemia/reperfusion (I/R) injury leads to an interest in using antioxidant therapy. Activating an endogenous antioxidant signaling pathway is more important due to the fact that the free radical scavenging behavior in vitro does not always correlate with a cytoprotection effect in vivo. Caffeic acid (CA), an antioxidant, is a major phenolic constituent in nature. Pyrrolidinyl caffeamide (PLCA), a derivative of CA, was compared with CA for their antioxidant and cytoprotective effects. Our results indicate that CA and PLCA exert the same ability to scavenge DPPH in vitro. In response to myocardial I/R stress, PLCA was shown to attenuate lipid peroxydation and troponin release more than CA. These responses were accompanied with a prominent elevation in AKT and HO-1 expression and a preservation of mnSOD expression and catalase activity. PLCA also improved cell viability and alleviated the intracellular ROS level more than CA in cardiomyocytes exposed to H2O2. When inhibiting the AKT or HO-1 pathways, PLCA lost its ability to recover mnSOD expression and catalase activity to counteract with oxidative stress, suggesting AKT/HO-1 pathway activation by PLCA plays an important role. In addition, inhibition of AKT signaling further abolished HO-1 activity, while inhibition of HO-1 signaling attenuated AKT expression, indicating cross-talk between the AKT and HO-1 pathways. These protective effects may contribute to the cardiac function improvement by PLCA. These findings provide new insight into therapeutic approaches using a modified natural compound against oxidative stress from myocardial injuries. PMID:26845693

  20. Application of MM wave therapy in radiology

    SciTech Connect

    Avakian, R.S.; Gasparyan, L.V.

    1995-12-31

    The authors studied the effects of MM wave electromagnetic radiation influence on patients, affected by X-ray radiation during the reparation works after Chernobyl nuclear power plant exposure. They compared results of treatment of two groups of patients: (1) control group patients received only basis therapy; (2) testing group, 10 patients received basis therapy and MM wave influence. The authors used the wide band noise generator `Artsakh - 2` for local irradiation on the acupuncture points. Their data proved that low intensity MM waves have immunocorrective, antioxidant effects, and MM wave therapy is a perspective method for treatment of patients with radiological pathology.

  1. Effects of Mg2+ on Ca2+ waves and Ca2+ transients of rat ventricular myocytes.

    PubMed

    Terada, H; Hayashi, H; Noda, N; Satoh, H; Katoh, H; Yamazaki, N

    1996-03-01

    It has been shown that the occurrence of the transient inward current, which is responsible for triggered activity, was often associated with propagating regions of increased intracellular Ca2+ concentration ([Ca2+]i), i.e., the "Ca2+ wave." To investigate the mechanism of antiarrhythmic action of Mg2+, we have studied effects of high concentrations of Mg2+ on Ca2+ waves in isolated rat ventricular myocytes. [Ca2+]i was estimated using the Ca(2+)-indicating probe indo 1. Ca2+ waves in myocytes, stimulated at 0.2 Hz, were induced by perfusion of isoproterenol (10(-7) M). High Mg2+ concentration suppressed Ca2+ waves in a concentration-dependent manner (36% at 4 mM, 70% at 8 mM, and 82% at 12 mM). The Ca2+ channel blocker verapamil also suppressed Ca2+ waves in a similar way. In contrast with marked depression of Ca2+ transients by verapamil, Ca2+ transients were not affected by high Mg2+ concentration (8 mM). High Mg2+ concentration also reduced frequencies of Ca2+ waves in the absence of electrical stimulation, whereas verapamil failed to reduce frequencies of Ca2+ waves. Reduction in frequency of Ca2+ waves by high Mg2+ concentration was associated with slowing of propagation velocity of Ca2+ waves. To examine whether suppressive effects of high Mg2+ concentration on Ca2+ waves were related to an increase in intracellular Mg2+ concentration ([Mg2+]i), the effect of high-Mg2+ solution on [Mg2+]i was examined in myocytes loaded with mag-fura 2. An increase in extracellular Mg2+ concentration from 1 to 12 mM increased [Mg2+]i from 1.06 +/- 0.16 to 1.87 +/- 0.22 mM (P < 0.01) in 30 min. To examine the effect of high Mg2+ concentration on amount of releasable Ca2+ in the sarcoplasmic reticulum, the effect of high Mg2+ concentration on the Ca2+ transient induced by a rapid application of caffeine was examined. High-Mg2+ solution increased the peak of the caffeine-induced Ca2+ transient. These results suggest that the inhibitory effect of Mg2+ on Ca2+ waves was not due

  2. 2-3 μm emission and fluorescent decaying behavior in Ho3+-doped tellurium germanate glass

    NASA Astrophysics Data System (ADS)

    Gao, Song; Liu, Xueqiang; Kang, Shuai; Liao, Meisong; Hu, Lili

    2016-03-01

    In this work, we report the 2.05 μm emission and ∼3 μm broadband spectra of Ho2O3-doped 33GeO2-30TeO2-27PbO-10CaO (in mol%) glass under 640 nm laser excitation. Clear emission spectra due to the 5I7-5I8 transition and the 5I6-5I7 transition in Ho3+ are observed. The 2.05 μm emission intensity and the full width at half maximum (FWHM) of the ∼3 μm broadband depend on the Ho concentration. The peak stimulated emission cross-section of Ho3+ is 6.57 × 10-21 cm2 at 2.05 μm, as calculated by the McCumber theory. The emission spectra are recorded and the maximum emission intensity at 2.05 μm is obtained at a doping level of 0.5 mol% Ho2O3 in the glass. A broad and flat emission band from 2700 nm to 3050 nm is observed in 2 mol% Ho2O3-doped tellurium germanate glass. The lifetime of the 5I7 state decreases with the increase in Ho3+ concentration due to non-radiative relaxation processes. An energy transfer coefficient of 271.88 mol-1 s-1 is obtained.

  3. Effects of Na+ and Ca2+ gradients on intracellular free Ca2+ in voltage-clamped Aplysia neurons.

    PubMed

    Levy, S; Tillotson, D

    1988-12-01

    Selected neurons of the abdominal ganglion of Aplysia californica were voltage-clamped and intracellular free Ca [( Ca2+]i) and Na [( Na+]i) concentrations were monitored with ion selective microelectrodes. Reducing [Na+]o from 500 mM (normal seawater, NSW) to 5 mM resulted in a decrease of the potential measured by the Ca electrode (VCa). Increasing [Ca2+]o from 10 to 50 mM increased [Ca2+]i two-fold, keeping [Ca2+]o at 50 mM and decreasing [Na+]o to 5 mM still led to a decrease in VCa. With 100 mM [Ca2+]o, which also increased [Ca2+]i, decreasing [Na+]o increased VCa in two of the eight cells tested. This indicates that in normal or moderately high resting [Ca2+]i, Ca2+ extrusion by Na/Ca exchange (forward mode) is not essential for [Ca2+]i buffering. [Na+]i was 12.9 +/- 3.6 mM (S.E.M., n = 7) in NSW; reducing [Na+]o to 5 mM decreased [Na+]i to 2.0 +/- 1.1 mM (S.E.M.). Keeping [Na+]o at 5 mM and increasing [Ca2+]o from 10 to 20 mM further decreased [Na+]i to about 1.0 mM, evidence of Na/Ca exchange operating in the reverse mode. Attempts to increase [Ca2+]i by bath application of the Ca ionophores A23187, X537A, ionomycin or ETH 1001 resulted in no measurable change of the resting [Ca2+]i. Application of Ouabain caused an apparent increase in [Ca2+]i in two of the six cells tested. In cells injected with the metallochromic indicator arsenazo III (AIII), the rate of the falling phase of the AIII absorbance increase, following a voltage-clamp pulse, was significantly slower in 5 mM [Na+]o. This indicates that in its forward mode Na-Ca exchange is active in clearing large submembrane increases in [Ca2+]i. PMID:3208137

  4. Multimedia contents production system (MM-CPS)

    NASA Astrophysics Data System (ADS)

    Roser, Miguel; Villegas, Paulo; Simon, Maria; Hernandez-Gil, J. F.; Aguado, Isidro

    1996-01-01

    A present characterized by deep worldwide changes, and a future where social relations and behaviors are going to undergo a substantial change need new telecommunications services in order to allow people to get closer, facilitate their daily tasks and place at their disposal multimedia information to be accessed anywhere and at any time. These new services are very dependent on the contents to be included in the applications. The purpose of this paper is to describe an universal MM contents production system (MM-CPS), which allows the generation of coded data files suitable to be included in MM-servers.

  5. 60W Ho:YLF oscillator-amplifier system

    NASA Astrophysics Data System (ADS)

    Koen, Wayne; Jacobs, Cobus; Wu, Lorinda; Strauss, Hencharl J.

    2015-02-01

    We developed a compact Ho:YLF oscillator-amplifier system end-pumped by two 54 W unpolarised Tm:fibre lasers, and produced 60.2 W of output power at 2064 nm. The oscillator consisted of a flat input coupler mirror, a 50 mm long 0.5 % doped Ho:YLF crystal rod, a 45 degree folding mirror, an AOM, and a concave output coupler mirror. The oscillator operated vertically polarised on the holmium crystal's σ-polarisation, ensuring good beam quality from the weak thermal lens. The concave output coupler had a radius of 300 mm and a reflectivity of 82 % at 2064 nm. The oscillator gave a maximum output of 24 W with an M2 of 1.06. The single-pass amplifier consisted of two 40 mm long, 0.5 % doped, Ho:YLF crystal rods and four folding mirrors. While the seed laser was pumped by a single fibre laser, the amplifier utilized the transmitted pump light from the seed laser in addition to the second fibre laser. With the first crystal amplifying on the σ-polarisation and the second crystal on the π-polarisation, the amplifier delivered 60.2 W with an M2 of 1.09, representing a gain of 2.5 while achieving an optical-to-optical efficiency of 55.5 %. When Q-switched with the AOM, the system delivered pulse lengths of between 43 and 113 ns at repetition rates from 15 to 40 kHz.

  6. A many-body model to study proteins. I. Applications to MLnm+ complexes, Mm+=Li+, Na+, K+, Mg2+, Ca2+, and Zn2+, L=H2O, CH3OH, HCONH2, n=1-6, and to small hydrogen bonded systems

    NASA Astrophysics Data System (ADS)

    Masella, Michel; Cuniasse, Philippe

    2003-07-01

    A new model to study proteinic systems including a many-body polarization and a hydrogen bond energy contribution is presented. This model represents an extension of an earlier water many-body model [M. Masella and J.-P. Flament, J. Chem. Phys. 107 9105 (1997)]. As in this earlier model, the new model is developed to reproduce quantum computations on small molecular aggregates, and, in this first paper, we focus our efforts in developing an accurate potential to describe interactions among all nonbonded atoms occurring in proteins, and among those atoms and six cations of biological interest: Li+, Na+, K+, Mg2+, Ca2+, and Zn2+. Intramolecular degrees of freedom are described as in classical two-body force fields. In the present paper, the new model is applied to investigate the properties of small ion-neutral [M,Ln]m+ complexes and of small hydrogen-bonded systems. The results showed that this model is able to reproduce most of the theoretical quantum predictions and experimental data published until now regarding those systems.

  7. Delayed cutaneous wound closure in HO-2 deficient mice despite normal HO-1 expression

    PubMed Central

    Lundvig, Ditte M S; Scharstuhl, Alwin; Cremers, Niels A J; Pennings, Sebastiaan W C; te Paske, Jeroen; van Rheden, René; van Run-van Breda, Coby; Regan, Raymond F; Russel, Frans G M; Carels, Carine E; Maltha, Jaap C; Wagener, Frank A D T G

    2014-01-01

    Impaired wound healing can lead to scarring, and aesthetical and functional problems. The cytoprotective haem oxygenase (HO) enzymes degrade haem into iron, biliverdin and carbon monoxide. HO-1 deficient mice suffer from chronic inflammatory stress and delayed cutaneous wound healing, while corneal wound healing in HO-2 deficient mice is impaired with exorbitant inflammation and absence of HO-1 expression. This study addresses the role of HO-2 in cutaneous excisional wound healing using HO-2 knockout (KO) mice. Here, we show that HO-2 deficiency also delays cutaneous wound closure compared to WT controls. In addition, we detected reduced collagen deposition and vessel density in the wounds of HO-2 KO mice compared to WT controls. Surprisingly, wound closure in HO-2 KO mice was accompanied by an inflammatory response comparable to WT mice. HO-1 induction in HO-2 deficient skin was also similar to WT controls and may explain this protection against exaggerated cutaneous inflammation but not the delayed wound closure. Proliferation and myofibroblast differentiation were similar in both two genotypes. Next, we screened for candidate genes to explain the observed delayed wound closure, and detected delayed gene and protein expression profiles of the chemokine (C-X-C) ligand-11 (CXCL-11) in wounds of HO-2 KO mice. Abnormal regulation of CXCL-11 has been linked to delayed wound healing and disturbed angiogenesis. However, whether aberrant CXCL-11 expression in HO-2 KO mice is caused by or is causing delayed wound healing needs to be further investigated. PMID:25224969

  8. MM Algorithms for Geometric and Signomial Programming.

    PubMed

    Lange, Kenneth; Zhou, Hua

    2014-02-01

    This paper derives new algorithms for signomial programming, a generalization of geometric programming. The algorithms are based on a generic principle for optimization called the MM algorithm. In this setting, one can apply the geometric-arithmetic mean inequality and a supporting hyperplane inequality to create a surrogate function with parameters separated. Thus, unconstrained signomial programming reduces to a sequence of one-dimensional minimization problems. Simple examples demonstrate that the MM algorithm derived can converge to a boundary point or to one point of a continuum of minimum points. Conditions under which the minimum point is unique or occurs in the interior of parameter space are proved for geometric programming. Convergence to an interior point occurs at a linear rate. Finally, the MM framework easily accommodates equality and inequality constraints of signomial type. For the most important special case, constrained quadratic programming, the MM algorithm involves very simple updates. PMID:24634545

  9. MM Algorithms for Geometric and Signomial Programming

    PubMed Central

    Lange, Kenneth; Zhou, Hua

    2013-01-01

    This paper derives new algorithms for signomial programming, a generalization of geometric programming. The algorithms are based on a generic principle for optimization called the MM algorithm. In this setting, one can apply the geometric-arithmetic mean inequality and a supporting hyperplane inequality to create a surrogate function with parameters separated. Thus, unconstrained signomial programming reduces to a sequence of one-dimensional minimization problems. Simple examples demonstrate that the MM algorithm derived can converge to a boundary point or to one point of a continuum of minimum points. Conditions under which the minimum point is unique or occurs in the interior of parameter space are proved for geometric programming. Convergence to an interior point occurs at a linear rate. Finally, the MM framework easily accommodates equality and inequality constraints of signomial type. For the most important special case, constrained quadratic programming, the MM algorithm involves very simple updates. PMID:24634545

  10. T-Type Ca2+ Channel Regulation by CO: A Mechanism for Control of Cell Proliferation.

    PubMed

    Duckles, Hayley; Al-Owais, Moza M; Elies, Jacobo; Johnson, Emily; Boycott, Hannah E; Dallas, Mark L; Porter, Karen E; Boyle, John P; Scragg, Jason L; Peers, Chris

    2015-01-01

    T-type Ca(2+) channels regulate proliferation in a number of tissue types, including vascular smooth muscle and various cancers. In such tissues, up-regulation of the inducible enzyme heme oxygenase-1 (HO-1) is often observed, and hypoxia is a key factor in its induction. HO-1 degrades heme to generate carbon monoxide (CO) along with Fe(2+) and biliverdin. Since CO is increasingly recognized as a regulator of ion channels (Peers et al. 2015), we have explored the possibility that it may regulate proliferation via modulation of T-type Ca(2+) channels.Whole-cell patch-clamp recordings revealed that CO (applied as the dissolved gas or via CORM donors) inhibited all 3 isoforms of T-type Ca(2+) channels (Cav3.1-3.3) when expressed in HEK293 cells with similar IC(50) values, and induction of HO-1 expression also suppressed T-type currents (Boycott et al. 2013). CO/HO-1 induction also suppressed the elevated basal [Ca(2+) ](i) in cells expressing these channels and reduced their proliferative rate to levels seen in non-transfected control cells (Duckles et al. 2015).Proliferation of vascular smooth muscle cells (both A7r5 and human saphenous vein cells) was also suppressed either by T-type Ca(2+) channel inhibitors (mibefradil and NNC 55-0396), HO-1 induction or application of CO. Effects of these blockers and CO were non additive. Although L-type Ca(2+) channels were also sensitive to CO (Scragg et al. 2008), they did not influence proliferation. Our data suggest that HO-1 acts to control proliferation via CO modulation of T-type Ca(2+) channels. PMID:26303493

  11. QM/MM Calculations on Proteins.

    PubMed

    Ryde, U

    2016-01-01

    In this chapter, I discuss combined quantum mechanics (QM) and molecular mechanics (MM; QM/MM) calculations for proteins. In QM/MM, a small but interesting part of the protein is treated by accurate QM methods, whereas the remainder is treated by faster MM methods. The prime problems with QM/MM calculations are bonds between the QM and MM systems, the selection of the QM system, and the local-minima problem. The two first problems can be solved by the big-QM approach, including in the QM calculation all groups within 4.5-6Å of the active site and all buried charges in the protein. The third problem can be solved by calculating free energies. It is important to study QM/MM energy components to ensure that the results are stable and reliable. They can also be used to understand the reaction and the effect of the surroundings, eg, by dividing the catalytic effect into bonded, van der Waals, electrostatic, and geometric components and to deduce which parts of the protein contribute most to the catalysis. It should be ensured that the QM calculations are reliable and converged by extending the basis set to quadruple-zeta quality, including a proper treatment of dispersion, as well as years experience and method development calculations with both pure and hybrid density functional theory methods. If the latter give differing results, calibration with high-level QM methods is needed. Reactions that change the net charge should be avoided. QM/MM calculations can be combined with experimental methods. PMID:27498637

  12. Dark filaments observed at 8.3mm and 3.1mm wavelength

    NASA Technical Reports Server (NTRS)

    Hiel, E.; Ishiguro, M.; Kosugi, T.; Shibasaki, K.

    1986-01-01

    Mapping of the sun was made at 3.1mm (98 GHz) and 8.3mm (36 GHz) wavelengths with a 45m dish radio telescope at the Nobeyama Cosmic Radio Observatory. The depressions associated with large H alpha filaments are derived to be -0.2 at 8.3mm and -0.05 at 3.1mm, which are darker than the values inferred by Raoult et al. (1979)

  13. 8. Credit USAF, ca. 1952. Original housed in the Photograph ...

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

    8. Credit USAF, ca. 1952. Original housed in the Photograph Files, AFFTC/HO, Edwards AFB, California. Oblique low-level aerial view of North Base looking northeast. Based on positions and types of aircraft and automobiles, this photo taken same day as HAER photo CA-170-7. Most temporary structures in this view have been demolished with the exception of the hangars. The concrete foundations remain of many structures, while no trace was found of others. - Edwards Air Force Base, North Base, North Base Road, Boron, Kern County, CA

  14. 40 CFR Table 1 to Subpart Mm of... - General Provisions Applicability to Subpart MM

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....860. 63.1(b)(2) Title V operating permit—see 40 CFR part 70 Yes All major affected sources are... Subpart MM 1 Table 1 to Subpart MM of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills Pt. 63, Subpt. MM,...

  15. 40 CFR Table 1 to Subpart Mm of... - General Provisions Applicability to Subpart MM

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....860. 63.1(b)(2) Title V operating permit—see 40 CFR part 70 Yes All major affected sources are... Subpart MM 1 Table 1 to Subpart MM of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills Pt. 63, Subpt. MM,...

  16. 40 CFR Table 1 to Subpart Mm of... - General Provisions Applicability to Subpart MM

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....860. 63.1(b)(2) Title V operating permit—see 40 CFR part 70 Yes All major affected sources are... Subpart MM 1 Table 1 to Subpart MM of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills Pt. 63, Subpt. MM,...

  17. 40 CFR Table 1 to Subpart Mm of... - General Provisions Applicability to Subpart MM

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....860. 63.1(b)(2) Title V operating permit—see 40 CFR part 70 Yes All major affected sources are... Subpart MM 1 Table 1 to Subpart MM of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills Pt. 63, Subpt. MM,...

  18. 40 CFR Table 1 to Subpart Mm of... - General Provisions Applicability to Subpart MM

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....860. 63.1(b)(2) Title V operating permit—see 40 CFR part 70 Yes All major affected sources are... Subpart MM 1 Table 1 to Subpart MM of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills Pt. 63, Subpt. MM,...

  19. Near infrared luminescence in Yb3+/Ho3+: co-doped germanate glass

    NASA Astrophysics Data System (ADS)

    Kochanowicz, Marcin; Żmojda, Jacek; Miluski, Piotr; Ragin, Tomasz; Jeleń, Piotr; Sitarz, Maciej; Dorosz, Dominik

    2015-12-01

    The near-infrared emission of low phonon (805 cm-1) germanate glasses from GeO2-Ga2O3-BaO system co-doped with 0.7Yb2O3/(0.07-0.7)Ho2O3 ions has been investigated. Luminescence at 2.1 μm corresponding to 5I7 → 5I8 transition in holmium was obtained by energy transfer between Yb3+ and Ho3+ ions. The optimization of the activator content and the concentration ratio were conducted with the purpose of maximizing the efficiency of energy transfer and as a consequence luminescence intensity at 2mm. The highest value of the luminescence intensity was obtained in glass codoped with 0.7Yb2O3/0.15 Ho2O3.

  20. In vitro investigation on Ho:YAG laser-assisted bone ablation underwater.

    PubMed

    Zhang, Xianzeng; Chen, Chuanguo; Chen, Faner; Zhan, Zhenlin; Xie, Shusen; Ye, Qing

    2016-07-01

    Liquid-assisted hard tissue ablation by infrared lasers has extensive clinical application. However, detailed studies are still needed to explore the underlying mechanism. In the present study, the dynamic process of bubble evolution induced by Ho:YAG laser under water without and with bone tissue at different thickness layer were studied, as well as its effects on hard tissue ablation. The results showed that the Ho:YAG laser was capable of ablating hard bone tissue effectively in underwater conditions. The penetration of Ho:YAG laser can be significantly increased up to about 4 mm with the assistance of bubble. The hydrokinetic forces associated with the bubble not only contributed to reducing the thermal injury to peripheral tissue, but also enhanced the ablation efficiency and improve the ablation crater morphology. The data also presented some clues to optimal selection of irradiation parameters and provided additional knowledge of the bubble-assisted hard tissue ablation mechanism. PMID:27056700

  1. Ferroelectricity and competing interactions in Ho-deficient non-stoichiometric orthorhombic HoMnO{sub 3}

    SciTech Connect

    Wang, J. X.; Yan, Z. B.; Xie, Y. L.; Zhou, X. H.; Liu, J.-M.

    2015-05-07

    We investigate the consequences of the Ho-deficient non-stoichiometry in orthorhombic HoMnO{sub 3} in terms of microscopic mechanisms for ferroelectricity modulation. It is suggested that the Ho-deficiency (then Mn excess) results in Ho-vacancies and then Mn occupation of the Ho-site with increasing non-stoichiometry. The Ho-deficiency enhances the Mn-Mn symmetric exchange striction by suppressing the independent Ho-Ho interaction, and thus benefits to the induced Ho spin ordering against the independent Ho spin ordering. The symmetric Ho-Mn exchange striction is thus enhanced by this induced Ho spin ordering, leading to remarkably enhanced ferroelectric polarization as observed. This work presents an alternative scheme to modulate the multiferroicity in rare-earth manganites of strong 4f-3d coupling.

  2. Tm:YLF Pumped Ho:YAG and Ho:LuAG Lasers

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P.; Reichle, Donald J.; Walsh, Brian M.; Axenson, Theresa J.

    2004-01-01

    Room temperature Ho:YAG and Ho:LuAG lasers pumped by a Tm:YLF laser demonstrated a 3.4 mJ threshold and 0.41 slope efficiency, incident optical to laser output energy. Results for numerous rod lengths, Ho concentrations, and output mirror reflectivities are presented.

  3. Laparoscopic cholecystectomy using 2-mm instruments.

    PubMed

    Uranüs, S; Peng, Z; Kronberger, L; Pfeifer, J; Salehi, B

    1998-10-01

    Today, laparoscopic cholecystectomy is the method of choice for treatment of symptomatic gallbladder disorders. It minimizes effects of the operation that are independent of the gallbladder, such as trauma to the abdominal wall and other soft tissue. The surgical wounds were even smaller when 2-mm trocars were used. Laparoscopic cholecystectomy using 2-mm instruments was performed in a consecutive series of 14 patients with symptomatic gallstones. The procedure was completed in 12 cases, with conversion to open surgery in two cases. Intraoperative cholangiography was always performed. The postoperative course was always uneventful. The cosmetic effect was highly satisfactory. The procedure using 2-mm instruments could be indicated in selected patients with uncomplicated gallstone disease. PMID:9820716

  4. Microeconomics of 300-mm process module control

    NASA Astrophysics Data System (ADS)

    Monahan, Kevin M.; Chatterjee, Arun K.; Falessi, Georges; Levy, Ady; Stoller, Meryl D.

    2001-08-01

    Simple microeconomic models that directly link metrology, yield, and profitability are rare or non-existent. In this work, we validate and apply such a model. Using a small number of input parameters, we explain current yield management practices in 200 mm factories. The model is then used to extrapolate requirements for 300 mm factories, including the impact of simultaneous technology transitions to 130nm lithography and integrated metrology. To support our conclusions, we use examples relevant to factory-wide photo module control.

  5. Investigation of loss processes of Tm and Tm,Ho in YAG

    NASA Technical Reports Server (NTRS)

    Armagan, G.; Buoncristiani, A. M.; Bair, C. H.; Inge, A. T.; Hess, R. V.

    1991-01-01

    The loss of excitation from various manifolds of Tm and Tm,Ho in YAG as a function of temperature and concentration is studied. Two probable loss mechanisms - a Tm up-conversion and a Ho up-conversion - are identified. A 785-nm CW diode laser with 400-nW peak power was focused to a small spot on the sample. The emission from the sample observed at 90 deg was monitored through a monochromator with slits open to 3 mm. Intensity of emission was measured by varying the power of the excitation source using a set of neutral density filters. Power is reported as the percentage of the peak power, and the intensity curves were normalized below 20 percent of transmission. The fact that there is emission above the pump energy indicates an up-conversion from excited manifolds. Nonlinear changes in the intensity of the emission from the Tm 3F4 manifold with the pump power reveals a loss of excitation from this manifold. The linear dependence of the 5I7 manifold emission with pump power at low Tm and high Ho concentrations and the gain of energy in the 5I6 manifold of Ho indicate that the 5I7 manifold loss is due to the coupling of Tm and Ho ions.

  6. Optimizing digital 8mm drive performance

    NASA Technical Reports Server (NTRS)

    Schadegg, Gerry

    1993-01-01

    The experience of attaching over 350,000 digital 8mm drives to 85-plus system platforms has uncovered many factors which can reduce cartridge capacity or drive throughput, reduce reliability, affect cartridge archivability and actually shorten drive life. Some are unique to an installation. Others result from how the system is set up to talk to the drive. Many stem from how applications use the drive, the work load that's present, the kind of media used and, very important, the kind of cleaning program in place. Digital 8mm drives record data at densities that rival those of disk technology. Even with technology this advanced, they are extremely robust and, given proper usage, care and media, should reward the user with a long productive life. The 8mm drive will give its best performance using high-quality 'data grade' media. Even though it costs more, good 'data grade' media can sustain the reliability and rigorous needs of a data storage environment and, with proper care, give users an archival life of 30 years or more. Various factors, taken individually, may not necessarily produce performance or reliability problems. Taken in combination, their effects can compound, resulting in rapid reductions in a drive's serviceable life, cartridge capacity, or drive performance. The key to managing media is determining the importance one places upon their recorded data and, subsequently, setting media usage guidelines that can deliver data reliability. Various options one can implement to optimize digital 8mm drive performance are explored.

  7. MM-122: High speed civil transport

    NASA Technical Reports Server (NTRS)

    Demarest, Bill; Anders, Kurt; Manchec, John; Yang, Eric; Overgaard, Dan; Kalkwarf, Mike

    1992-01-01

    The rapidly expanding Pacific Rim market along with other growing markets indicates that the future market potential for a high speed civil transport is great indeed. The MM-122 is the answer to the international market desire for a state of the art, long range, high speed civil transport. It will carry 250 passengers a distance of 5200 nm at over twice the speed of sound. The MM-122 is designed to incorporate the latest technologies in the areas of control systems, propulsions, aerodynamics, and materials. The MM-122 will accomplish these goals using the following design parameters. First, a double delta wing planform with highly swept canards and an appropriately area ruled fuselage will be incorporated to accomplish desired aerodynamic characteristics. Propulsion will be provided by four low bypass variable cycle turbofan engines. A quad-redundant fly-by-wire flight control system will be incorporated to provide appropriate static stability and level 1 handling qualities. Finally, the latest in conventional metallic and modern composite materials will be used to provide desired weight and performance characteristics. The MM-122 incorporates the latest in technology and cost minimization techniques to provide a viable solution to this future market potential.

  8. CCM3 to MM5 Data Conversion

    Energy Science and Technology Software Center (ESTSC)

    2007-03-02

    The accompanying script (which uses the NCAR Command Language) ready output from the Community Climate Model Code, version 3 (CCM3) and converts it to input format for the Mesoscale Model, version 5 (MM5) code. The script utilizes a Fortran binary write routine.

  9. Mm-wave power meter mount

    NASA Technical Reports Server (NTRS)

    Mullen, D. L.; Oltmans, D. A.; Stelzried, C. T.

    1968-01-01

    E-band thermistor mount and a technique for adjusting a temperature compensating thermistor to provide an electrically balanced bridge are used for measuring RF power in the mm-wavelength. The mount is relatively insensitive to temperature effects that cause measurement errors in single ended circuits.

  10. Shape coexistence in 153Ho

    NASA Astrophysics Data System (ADS)

    Pramanik, Dibyadyuti; Sarkar, S.; Saha Sarkar, M.; Bisoi, Abhijit; Ray, Sudatta; Dasgupta, Shinjinee; Chakraborty, A.; Krishichayan, Kshetri, Ritesh; Ray, Indrani; Ganguly, S.; Pradhan, M. K.; Ray Basu, M.; Raut, R.; Ganguly, G.; Ghugre, S. S.; Sinha, A. K.; Basu, S. K.; Bhattacharya, S.; Mukherjee, A.; Banerjee, P.; Goswami, A.

    2016-08-01

    The high-spin states in 153Ho have been studied by the La57(20Ne139,6 n ) reaction at a projectile energy of 139 MeV at the Variable Energy Cyclotron Centre (VECC), Kolkata, India, utilizing an earlier campaign of the Indian National Gamma Array (INGA) setup. Data from γ -γ coincidence, directional correlation, and polarization measurements have been analyzed to assign and confirm the spins and parities of the levels. We have suggested a few additions and revisions of the reported level scheme of 153Ho. The RF-γ time difference spectra have been useful to confirm the half-life of an isomer in this nucleus. From the comparison of experimental and theoretical results, it is found that there are definite indications of shape coexistence in this nucleus. The experimental and calculated lifetimes of several isomers have been compared to follow the coexistence and evolution of shape with increasing spin.

  11. The role of luminal Ca2+ in the generation of Ca2+ waves in rat ventricular myocytes

    PubMed Central

    Lukyanenko, Valeriy; Subramanian, Saisunder; Györke, Inna; Wiesner, Theodore F; Györke, Sandor

    1999-01-01

    We used confocal Ca2+ imaging and fluo-3 to investigate the transition of localized Ca2+ releases induced by focal caffeine stimulation into propagating Ca2+ waves in isolated rat ventricular myocytes. Self-sustaining Ca2+ waves could be initiated when the cellular Ca2+ load was increased by elevating the extracellular [Ca2+] ([Ca2+]o) and they could also be initiated at normal Ca2+ loads when the sensitivity of the release sites to cytosolic Ca2+ was enhanced by low doses of caffeine. When we prevented the accumulation of extra Ca2+ in the luminal compartment of the sarcoplasmic reticulum (SR) with thapsigargin, focal caffeine pulses failed to trigger self-sustaining Ca2+ waves on elevation of [Ca2+]o. Inhibition of SR Ca2+ uptake by thapsigargin in cells already preloaded with Ca2+ above normal levels did not prevent local Ca2+ elevations from triggering propagating waves. Moreover, wave velocity increased by 20 %. Tetracaine (0·75 mM) caused transient complete inhibition of both local and propagating Ca2+ signals, followed by full recovery of the responses due to increased SR Ca2+ accumulation. Computer simulations using a numerical model with spatially distinct Ca2+ release sites suggested that increased amounts of releasable Ca2+ might not be sufficient to generate self-sustaining Ca2+ waves under conditions of Ca2+ overload unless the threshold of release site Ca2+ activation was set at relatively low levels (< 1·5 μM). We conclude that the potentiation of SR Ca2+ release channels by luminal Ca2+ is an important factor in Ca2+ wave generation. Wave propagation does not require the translocation of Ca2+ from the spreading wave front into the SR. Instead, it relies on luminal Ca2+ sensitizing Ca2+ release channels to cytosolic Ca2+. PMID:10373699

  12. A New Laboratory for MM-/Sub-MM-Wave Characterization of Cosmic Dust Analogs

    NASA Astrophysics Data System (ADS)

    Birsa, Samuel; Do, Huy; Williams, Frederick; Liu, Lunjun; Schonert, Ryan; Perera, Thushara

    2015-01-01

    Most studies conducted with observatories such as ALMA, SOFIA, PLANCK, and Herschel will benefit from knowledge of (1) the predominant cosmic dust species in various environments, in terms of composition and structure and (2) mm/sub-mm optical properties of cosmic dusts, including the temperature dependent-emissivity and spectral index. A new laboratory has been established for producing and characterizing (in the mm/sub-mm) various silicate/carbonaceous dust candidates. In particular, the optical measurement setup was custom designed, specifically for laboratory studies of dusts, using techniques borrowed from observational cosmology. It features novel designs for a compact Fourier Transform Spectrometer (FTS) and a cold sample holder/exchanger. Construction of this apparatus is now complete; we are currently testing the system. Here, we present the mm/sub-mm measurement scheme and highlight its innovative and aspects.

  13. Comparison between 28 mm and 32 mm ceramic-on-ceramic bearings in total hip replacement.

    PubMed

    Lee, Y K; Ha, Y C; Koo, K H

    2014-11-01

    Large femoral heads have become popular in total hip replacement (THR) as a method of reducing the risk of dislocation. However, if large heads are used in ceramic-on-ceramic THR, the liner must be thinner, which may increase the risk of fracture. To compare the rates of ceramic fracture and dislocation between 28 mm and 32 mm ceramic heads, 120 hips in 109 patients (51 men and 58 women, mean age 49.2 years) were randomised to THR with either a 28 mm or a 32 mm ceramic articulation. A total of 57/60 hips assigned to the 28 mm group and 55/60 hips assigned to the 32 mm group were followed for at least five years. No ceramic component fractures occured in any patient in either group. There was one dislocation in the 32 mm group and none in the 28 mm group (p = 0.464). No hip had detectable wear, focal osteolysis or prosthetic loosening. In our small study the 32 mm ceramic articulation appeared to be safe in terms of ceramic liner fracture. PMID:25371457

  14. Peroxynitric acid (HO2NO2) measurements during the UBWOS 2013 and 2014 studies using iodide ion chemical ionization mass spectrometry

    NASA Astrophysics Data System (ADS)

    Veres, P. R.; Roberts, J. M.; Wild, R. J.; Edwards, P. M.; Brown, S. S.; Bates, T. S.; Quinn, P. K.; Johnson, J. E.; Zamora, R. J.; de Gouw, J.

    2015-07-01

    In this paper laboratory work is documented establishing iodide ion chemical ionization mass spectrometry (I- CIMS) as a sensitive method for the unambiguous detection of peroxynitric acid (HO2NO2; PNA). A dynamic calibration source for HO2NO2, HO2, and HONO was developed and calibrated using a novel total NOy cavity ring-down spectroscopy (CaRDS) detector. Photochemical sources of these species were used for the calibration and validation of the I- CIMS instrument for detection of HO2NO2. Ambient observations of HO2NO2 using I- CIMS during the 2013 and 2014 Uintah Basin Wintertime Ozone Study (UBWOS) are presented. Strong inversions leading to a build-up of many primary and secondary pollutants as well as low temperatures drove daytime HO2NO2 as high as 1.5 ppbv during the 2013 study. A comparison of HO2NO2 observations to mixing ratios predicted using a chemical box model describing an ozone formation event observed during the 2013 wintertime shows agreement in the daily maxima HO2NO2 mixing ratio, but a differences of several hours in the timing of the observed maxima. Observations of vertical gradients suggest that the ground snow surface potentially serves as both a net sink and source of HO2NO2 depending on the time of day. Sensitivity tests using a chemical box model indicate that the lifetime of HO2NO2 with respect to deposition has a non-negligible impact on ozone production rates on the order of 10 %.

  15. AN ELISA ASSAY FOR HEME OXYGENASE (HO-1)

    EPA Science Inventory

    An ELISA assay for heme oxygenase (HO-l )

    Abstract

    A double antibody capture ELISA for the HO-l protein has been developed to separately quantitate HO-I protein. The use of 2.5% NP40 detergent greatly assists in freeing HO-l protein from membranes and/or other cel...

  16. Registration of "HoCP 00-950" Sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    HoCP 00-950 sugarcane was selected from progeny of the cross HoCP 93-750 x HoCP 92-676 made at Canal Point, Florida. HoCP 00-950 was developed through cooperative research by the Agricultural Research Service of the United States Department of Agriculture, the Louisiana Agricultural Experiment Stati...

  17. Development of mini-tablets with 1mm and 2mm diameter.

    PubMed

    Tissen, Corinna; Woertz, Katharina; Breitkreutz, Joerg; Kleinebudde, Peter

    2011-09-15

    The feasibility of formulating mini-tablets with 1mm diameter on a rotary-die press in comparison to mini-tablets of 2mm was investigated. To gain insight into the production of 1mm mini-tablets, three model drugs of different compression characteristics were chosen, namely quinine hydrochloride, ibuprofen and spray-dried gentian extract. A high drug load in combination with robust and reproducible mechanical properties was requested. Depending on the individual drug substance, mini-tablets were produced by direct compression or after roll-compaction/dry granulation. The tensile strength, mass, and their variation coefficients were determined to assess the mechanical properties of the tablets. The content uniformity and the dissolution behavior of selected batches were analyzed. For the first time 1mm mini-tablets could be successfully produced by direct compression (90% quinine hydrochloride; 90% dried gentian extract) and after roll compaction (70% ibuprofen). Depending on the applied compression pressure, 1mm mini-tablets with quinine hydrochloride exhibited robust mechanical properties (e.g. median tensile strength of 2.02N/mm(2)) with equal or lower variance of distribution compared to the 2mm compacts. With respect to content uniformity of dosage forms, 1mm mini-tablets containing 80% quinine hydrochloride met the requirements of the European Pharmacopeia (AV=6.8). PMID:21726616

  18. Impact of Ho(3+)-doping on (13)C dynamic nuclear polarization using trityl OX063 free radical.

    PubMed

    Kiswandhi, Andhika; Niedbalski, Peter; Parish, Christopher; Kaur, Pavanjeet; Martins, André; Fidelino, Leila; Khemtong, Chalermchai; Song, Likai; Sherry, A Dean; Lumata, Lloyd

    2016-08-21

    We have investigated the effects of Ho-DOTA doping on the dynamic nuclear polarization (DNP) of [1-(13)C] sodium acetate using trityl OX063 free radical at 3.35 T and 1.2 K. Our results indicate that addition of 2 mM Ho-DOTA on 3 M [1-(13)C] sodium acetate sample in 1 : 1 v/v glycerol : water with 15 mM trityl OX063 improves the DNP-enhanced (13)C solid-state nuclear polarization by a factor of around 2.7-fold. Similar to the Gd(3+) doping effect on (13)C DNP, the locations of the positive and negative (13)C maximum polarization peaks in the (13)C microwave DNP sweep are shifted towards each other with the addition of Ho-DOTA on the DNP sample. W-band electron spin resonance (ESR) studies have revealed that while the shape and linewidth of the trityl OX063 ESR spectrum was not affected by Ho(3+)-doping, the electron spin-lattice relaxation time T1 of trityl OX063 was prominently reduced at cryogenic temperatures. The reduction of trityl OX063 electron T1 by Ho-doping is linked to the (13)C DNP improvement in light of the thermodynamic picture of DNP. Moreover, the presence of Ho-DOTA in the dissolution liquid at room temperature has negligible reduction effect on liquid-state (13)C T1, in contrast to Gd(3+)-doping which drastically reduces the (13)C T1. The results here suggest that Ho(3+)-doping is advantageous over Gd(3+) in terms of preservation of hyperpolarized state-an important aspect to consider for in vitro and in vivo NMR or imaging (MRI) experiments where a considerable preparation time is needed to administer the hyperpolarized (13)C liquid. PMID:27424954

  19. 3. East portal of Tunnel 34, view to southsouthwest, 135mm ...

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

    3. East portal of Tunnel 34, view to south-southwest, 135mm lens with electronic flash fill. Note the shift, in these later tunnels east of Colfax, to concrete portal faces with granite masonry voussoirs and coping. - Central Pacific Transcontinental Railroad, Tunnel No. 34, Milepost 145.4, Colfax, Placer County, CA

  20. Building 810, oblique view to eastsoutheast, 90mm lens. Note buttressed ...

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

    Building 810, oblique view to east-southeast, 90mm lens. Note buttressed end wall extensions into which main doors nest. - Travis Air Force Base, B-36 Hangar, Between Woodskill Avenue & Ellis, adjacent to Taxiway V & W, Fairfield, Solano County, CA

  1. 14. Main room; view no southwest, 65mm lens with electronic ...

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

    14. Main room; view no southwest, 65mm lens with electronic flash illumination. The mountain visible through the windows was a landmark for the camp population. - Tule Lake Project Jail, Post Mile 44.85, State Route 139, Newell, Modoc County, CA

  2. 10. Southeast end; view to northwest, 65mm lens. Note evidence ...

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

    10. Southeast end; view to northwest, 65mm lens. Note evidence of extreme building failure caused by adjacent railroad cut, which necessitated building demolition. (Vignetting due to extreme use of camera swing necessitated by lack of space to position camera otherwise.) - Benicia Arsenal, Powder Magazine No. 5, Junction of Interstate Highways 680 & 780, Benicia, Solano County, CA

  3. 2. West portal of Tunnel 1, view to northeast, 135mm ...

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

    2. West portal of Tunnel 1, view to northeast, 135mm lens. Like the new tunnels built during this period, Tunnel 1 received a new concrete portal face with granite masonry voussoirs and coping. - Central Pacific Transcontinental Railroad, Tunnel No. 1, Milepost 164.34, Blue Canyon, Placer County, CA

  4. 5. East portal of Tunnel 18, view to westsouthwest, 135mm ...

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

    5. East portal of Tunnel 18, view to west-southwest, 135mm lens. The train exiting the tunnel, though northbound toward Portland, is considered an eastbound train on the Southern Pacific (see explanation above). - Southern Pacific Railroad Natron Cutoff, Tunnel No. 18, Milepost 410, Dorris, Siskiyou County, CA

  5. 1. East portal of Tunnel 3, view to west, 135mm ...

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

    1. East portal of Tunnel 3, view to west, 135mm lens. This tunnel was photographed to provide context, because even though somewhat enlarged, it illustrates the nature of the unlined hard rock tunnels typical of the original Central Pacific construction in 1868. - Central Pacific Transcontinental Railroad, Tunnel No. 3, Milepost 180.65, Cisco, Placer County, CA

  6. Detail, typical window fenestrations, east façade, view to westnorthwest (135mm ...

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

    Detail, typical window fenestrations, east façade, view to west-northwest (135mm lens). Note "timber" header, adobe bench in front of window. - Burton Park, Club House & Amphitheater, Adjacent ot south end of Chestnut Avenue, San Carlos, San Mateo County, CA

  7. 3. West portal of Tunnel 26, view to northeast, 135mm ...

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

    3. West portal of Tunnel 26, view to northeast, 135mm lens. Note use of granite voussoirs and coping on this otherwise all-reinforced concrete structure. - Central Pacific Transcontinental Railroad, Tunnel No. 26, Milepost 133.29, Applegate, Placer County, CA

  8. 3. West portal of Tunnel 18, view to northeast, 135mm ...

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

    3. West portal of Tunnel 18, view to northeast, 135mm lens. Note the use of concrete face and wingwalls, with dressed stone voussoirs, wingwall coping, parapet with stone belt course and coping, and coursed stone masonry slope protection flanking the portal. - Southern Pacific Railroad Natron Cutoff, Tunnel No. 17, Milepost 408, Dorris, Siskiyou County, CA

  9. 5. East portal of Tunnel 28, view to southsouthwest, 135mm ...

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

    5. East portal of Tunnel 28, view to south-southwest, 135mm lens. Shed above portal appears to have housed machinery connected with a counterweighted curtain mechanism used to help dissipate smoke from this 3,209-foot tunnel during the days of steam locomotive use - Central Pacific Transcontinental Railroad, Tunnel No. 28, Milepost 134.75, Applegate, Placer County, CA

  10. 2. West portal of Snowshed 29, view to east, 135mm ...

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

    2. West portal of Snowshed 29, view to east, 135mm lens. Note the heavy timber frame, with battered posts to carry the tremendous snow loads of winter. - Central Pacific Transcontinental Railroad, Tunnel No. 41, Milepost 193.3, Donner, Placer County, CA

  11. Rotman lens for mm-wavelengths

    NASA Astrophysics Data System (ADS)

    Hall, Leonard T.; Hansen, Hedley J.; Abbott, Derek

    2002-11-01

    The 77 GHz band has been reserved for intelligent cruise control in luxury cars and some public transport services in America and the United Kingdom. The Rotman lens offers a cheap and compact means to extend the single beam systems generally used, to fully functional beam staring arrangements. Rotman lenses have been built for microwave frequencies with limited success. The flexibility of microstrip transmission lines and the advent of fast accurate simulation packages allow practical Rotman lenses to be designed at mm-wavelengths. This paper discusses the limitations of the conventional design approach and predicts the performance of a new Rotman lens designed at 77 GHz.

  12. Presence of an HO-1 expression threshold in renal glomeruli.

    PubMed

    Detsika, Maria G; Atsaves, Vassileios; Papalois, Apostolos; Lianos, Elias A

    2015-12-01

    This article reports data describing HO-1 expression patterns of heme oxygenase (HO)-1 in isolated rat glomeruli and in cultured glomerular epithelial cells (GEC) in response to its natural substrate heme. Qualitative and quantitative data are presented to support presence of a HO-1 expression threshold in glomeruli but not in GEC. Interpretation of our data and further insight into HO-1 expression pattern in glomeruli may be found in 'HO-1 expression control in the rat glomerulus' [1]. PMID:26702422

  13. Influence of pH on Ca2+ current and its control of electrical and Ca2+ signaling in ventricular myocytes

    PubMed Central

    Saegusa, Noriko; Moorhouse, Emma; Vaughan-Jones, Richard D.

    2011-01-01

    Modulation of L-type Ca2+ current (ICa,L) by H+ ions in cardiac myocytes is controversial, with widely discrepant responses reported. The pH sensitivity of ICa,L was investigated (whole cell voltage clamp) while measuring intracellular Ca2+ (Ca2+i) or pHi (epifluorescence microscopy) in rabbit and guinea pig ventricular myocytes. Selectively reducing extracellular or intracellular pH (pHo 6.5 and pHi 6.7) had opposite effects on ICa,L gating, shifting the steady-state activation and inactivation curves to the right and left, respectively, along the voltage axis. At low pHo, this decreased ICa,L, whereas at low pHi, it increased ICa,L at clamp potentials negative to 0 mV, although the current decreased at more positive potentials. When Ca2+i was buffered with BAPTA, the stimulatory effect of low pHi was even more marked, with essentially no inhibition. We conclude that extracellular H+ ions inhibit whereas intracellular H+ ions can stimulate ICa,L. Low pHi and pHo effects on ICa,L were additive, tending to cancel when appropriately combined. They persisted after inhibition of calmodulin kinase II (with KN-93). Effects are consistent with H+ ion screening of fixed negative charge at the sarcolemma, with additional channel block by H+o and Ca2+i. Action potential duration (APD) was also strongly H+ sensitive, being shortened by low pHo, but lengthened by low pHi, caused mainly by H+-induced changes in late Ca2+ entry through the L-type Ca2+ channel. Kinetic analyses of pH-sensitive channel gating, when combined with whole cell modeling, successfully predicted the APD changes, plus many of the accompanying changes in Ca2+ signaling. We conclude that the pHi-versus-pHo control of ICa,L will exert a major influence on electrical and Ca2+-dependent signaling during acid–base disturbances in the heart. PMID:22042988

  14. Basal Ca2+ and the oscillation of Ca2+ in caffeine-treated bullfrog sympathetic neurones.

    PubMed Central

    Nohmi, M; Hua, S Y; Kuba, K

    1992-01-01

    1. Effects of caffeine on the intracellular free Ca2+ concentration ([Ca2+]i) in single bullfrog sympathetic neurones in excised tissue were studied by recording Fura-2 fluorescence excited at 340, 361 or 380 nm and taking their ratios (R340/380 or R361/380). 2. Caffeine (3-10 mM) produced oscillation of [Ca2+]i and an 'apparent' decrease in the basal level of [Ca2+]i during a period between phasic rises. The mechanism of the latter effect was analysed in relation to the mechanism of the former. 3. Caffeine (3-10 mM) increased Fura-2 fluorescence in a range of excitation wavelength from 330 to 390 nm. The ratios of fluorescences, R340/380 and R361/380, however, were not significantly affected by caffeine. These results suggest that the 'apparent' reduction in the basal [Ca2+]i seen as a decrease in R340/380 or R361/380 results from a true decrease in [Ca2+]i. 4. Caffeine-induced decrease in [Ca2+]i persisted for every period between phasic rises of [Ca2+]i during [Ca2+]i oscillation, and after the blockade of [Ca2+]i oscillation by ryanodine. The decrease in the latter condition lasted for more than 20 min. 5. The decrease in the basal [Ca2+]i depended on the external Ca2+ concentration and was not mimicked by the action of cyclic nucleotides. 6. Possible mechanisms underlying the decrease in the basal [Ca2+]i produced by caffeine (effects on Ca2+ transport at the cell or Ca(2+)-storing organelle membrane) and their significance in relation to the [Ca2+]i oscillation were discussed. PMID:1432716

  15. Effects of Ca antagonists on Ca fluxes in resistance vessels

    SciTech Connect

    Cauvin, C.; Saida, K.; van Breemen, C.

    1982-01-01

    Researchers have examined contractions and /sup 45/Ca fluxes induced by norepinephrine (NE) and 80 mM potassium (high K) depolarization and their inhibition by dilitazem in rabbit mesenteric resistance vessels. Contraction induced by both NE and high K depended almost completely on extracellular Ca. Dose-response curves for diltiazem inhibition of NE (10(-5) M) and high K contractions showed ED50 values of 1 X 10(-8) and 6 X 10(-7) M, respectively, indicating that the receptor-operated channel (ROC) was more sensitive than the potential-operated channel (POC) to the action of diltiazem. Diltiazem (10(-6) M) was shown to inhibit NE- and 80 mM K-stimulated /sup 45/Ca influx effectively by 87 +/- 15 and 85 +/- 10%, respectively. Comparison of these data to those obtained from aorta suggest that although the sensitivity of the POC is approximately the same in aorta and mesenteric resistance vessels, the sensitivity of the ROC is much greater in the latter. This increased sensitivity is paralleled by a greatly decreased role of intracellular Ca release in NE contraction in mesenteric resistance vessels.

  16. Thermochemistry of HO2 + HO2 → H2O4: Does HO2 Dimerization Affect Laboratory Studies?

    PubMed

    Sprague, Matthew K; Irikura, Karl K

    2015-07-01

    Self-reaction is an important sink for the hydroperoxy radical (HO2) in the atmosphere. It has been suggested (Denis, P. A.; Ornellas, F. R. J. Phys. Chem. A, 2009, 113 (2), 499-506) that the minor product hydrogen tetroxide (HO4H) may act as a reservoir of HO2. Here, we compute the thermochemistry of HO2 self-reactions to determine if either HO4H or the cyclic hydrogen-bound dimer (HO2)2 can act as reservoirs. We computed electronic energies using coupled-cluster calculations in the complete basis set limit, CCSD(T)/CBS[45]//CCSD(T)/cc-pVTZ. Our model chemistry includes corrections for vibrational anharmonicity in the zero-point energy and vibrational partition functions, core-valence correlation, scalar relativistic effects, diagonal Born-Oppenheimer, spin-orbit splitting, and higher-order corrections. We compute the Gibbs energy of dimerization to be (-20.1 ± 1.6) kJ/mol at 298.15 K (2σ uncertainty), and (-32.3 ± 1.5) kJ/mol at 220 K. For atmospherically relevant [HO2] = 10(8) molecules per cm(3), our thermochemistry indicates that dimerization will be negligible, and thus H2O4 species are atmospherically unimportant. Under conditions used in laboratory experiments ([HO2] > 10(12) molecules per cm(3), 220 K), H2O4 formation may be significant. We compute two absorption spectra that could be used for laboratory detection of HO4H: the OH stretch overtone (near-IR) and electronic (UV) spectra. PMID:26066551

  17. Kinetics and stoichiometry of coupled Na efflux and Ca influx (Na/Ca exchange) in barnacle muscle cells.

    PubMed

    Rasgado-Flores, H; Santiago, E M; Blaustein, M P

    1989-06-01

    Coupled Na+ exit/Ca2+ entry (Na/Ca exchange operating in the Ca2+ influx mode) was studied in giant barnacle muscle cells by measuring 22Na+ efflux and 45Ca2+ influx in internally perfused, ATP-fueled cells in which the Na+ pump was poisoned by 0.1 mM ouabain. Internal free Ca2+, [Ca2+]i, was controlled with a Ca-EGTA buffering system containing 8 mM EGTA and varying amounts of Ca2+. Ca2+ sequestration in internal stores was inhibited with caffeine and a mitochondrial uncoupler (FCCP). To maximize conditions for Ca2+ influx mode Na/Ca exchange, and to eliminate tracer Na/Na exchange, all of the external Na+ in the standard Na+ sea water (NaSW) was replaced by Tris or Li+ (Tris-SW or LiSW, respectively). In both Na-free solutions an external Ca2+ (Cao)-dependent Na+ efflux was observed when [Ca2+]i was increased above 10(-8) M; this efflux was half-maximally activated by [Ca2+]i = 0.3 microM (LiSW) to 0.7 microM (Tris-SW). The Cao-dependent Na+ efflux was half-maximally activated by [Ca2+]o = 2.0 mM in LiSW and 7.2 mM in Tris-SW; at saturating [Ca2+]o, [Ca2+]i, and [Na+]i the maximal (calculated) Cao-dependent Na+ efflux was approximately 75 pmol#cm2.s. This efflux was inhibited by external Na+ and La3+ with IC50's of approximately 125 and 0.4 mM, respectively. A Nai-dependent Ca2+ influx was also observed in Tris-SW. This Ca2+ influx also required [Ca2+]i greater than 10(-8) M. Internal Ca2+ activated a Nai-independent Ca2+ influx from LiSW (tracer Ca/Ca exchange), but in Tris-SW virtually all of the Cai-activated Ca2+ influx was Nai-dependent (Na/Ca exchange). Half-maximal activation was observed with [Na+]i = 30 mM. The fact that internal Ca2+ activates both a Cao-dependent Na+ efflux and a Nai-dependent Ca2+ influx in Tris-SW implies that these two fluxes are coupled; the activating (intracellular) Ca2+ does not appear to be transported by the exchanger. The maximal (calculated) Nai-dependent Ca2+ influx was -25 pmol/cm2.s. At various [Na+]i between 6 and 106 mM

  18. A caffeine- and ryanodine-sensitive Ca2+ store in bullfrog sympathetic neurones modulates effects of Ca2+ entry on [Ca2+]i.

    PubMed Central

    Friel, D D; Tsien, R W

    1992-01-01

    1. We studied how in changes in cytosolic free Ca2+ concentration ([Ca2+]i) produced by voltage-dependent Ca2+ entry are influenced by a caffeine-sensitive Ca2+ store in bullfrog sympathetic neurones. Ca2+ influx was elicited by K+ depolarization and the store was manipulated with either caffeine or ryanodine. 2. For a time after discharging the store with caffeine and switching to a caffeine-free medium: (a) [Ca2+]i was depressed by up to 40-50 nM below the resting level, (b) caffeine responsiveness was diminished, and (c) brief K+ applications elicited [Ca2+]i responses with slower onset and faster recovery than controls. These effects were more pronounced as the conditioning caffeine concentration was increased over the range 1-30 mM. 3. [Ca2+]i, caffeine and K+ responsiveness recovered in parallel with a half-time of approximately 2 min. Recovery required external Ca2+ and was speeded by increasing the availability of cytosolic Ca2+, suggesting that it reflected replenishment of the store at the expense of cytosolic Ca2+. 4. During recovery, Ca2+ entry stimulated by depolarization had the least effect on [Ca2+]i when the store was filling most rapidly. This suggests that the effect of Ca2+ entry on [Ca2+]i is modified, at least in part, because some of the Ca2+ which enters the cytosol during stimulation is taken up by the store as it refills. 5. Further experiments were carried out to investigate whether the store can also release Ca2+ in response to stimulated Ca2+ entry. In the continued presence of caffeine at a low concentration (1 mM), high K+ elicited a faster and larger [Ca2+]i response compared to controls; at higher concentrations of caffeine (10 and 30 mM) responses were depressed. 6. Ryanodine (1 microM) reduced the rate at which [Ca2+]i increased with Ca2+ entry, but not to the degree observed after discharging the store. At this concentration, ryanodine completely blocked responses to caffeine but had no detectable effect on Ca2+ channel current

  19. Gonadotropin-releasing hormone-induced Ca2+ transients in single identified gonadotropes require both intracellular Ca2+ mobilization and Ca2+ influx.

    PubMed Central

    Shangold, G A; Murphy, S N; Miller, R J

    1988-01-01

    We examined the effects of gonadotropin-releasing hormone (GnRH) on the intracellular free Ca2+ concentration ([Ca2+]i) in single rat anterior pituitary gonadotropes identified by a reverse hemolytic plaque assay. Concentrations of GnRH greater than 10 pM elicited increases in [Ca2+]i in identified cells but not in others. In contrast, depolarization induced by 50 mM K+ increased [Ca2+]i in all cells. Ca2+ transients induced by GnRH exhibited a complex time course. After an initial rapid rise, the [Ca2+]i fell to near basal levels only to be followed by a secondary extended rise and fall. Analysis of the Ca2+ transients on a rapid time base revealed that responses frequently consisted of several rapid oscillations in [Ca2+]i. Removal of extracellular Ca2+ or addition of the dihydropyridine Ca2+-channel blocker nitrendipine completely blocked the secondary rise in [Ca2+]i but had no effect whatsoever on the initial spike. Nitrendipine also blocked 50 mM K+-induced increases in [Ca2+]i in identified gonadotropes. The secondary rise induced by GnRH could be enhanced by a phorbol ester in a nitrendipine-sensitive fashion. Multiple spike responses to GnRH stimulation of the same cell could only be obtained if subsequent Ca2+ influx was permitted either by allowing a secondary rise to occur or by producing a Ca2+ transient by depolarizing the cells with 50 mM K+. It therefore appears that the response to GnRH consists of an initial phase of Ca2+ mobilization, probably mediated by inositol trisphosphate, and a subsequent phase of Ca2+ influx through nitrendipine-sensitive Ca2+ channels that may be activated by protein kinase C. The relative roles of these phases in the control of gonadotropin secretion are discussed. Images PMID:3045819

  20. 4. Credit USAF, ca. 1945. Original housed in the Photograph ...

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

    4. Credit USAF, ca. 1945. Original housed in the Photograph Files, AFFTC/HO, Edwards AFB, California. Low level oblique aerial view of Muroc Flight Test Base (North Base), looking southwest along flightline. HANG-P-A hangar (Building 4505) is in the right foreground. A Bell XP-59A Airacomet, the United States military's first jet propelled aircraft, is being towed on the apron toward the control tower. Other aircraft in the foreground include Douglas DC-3s, North American Aviation P-51 Mustangs, and Lockheed P-38 Lightnings. - Edwards Air Force Base, North Base, North Base Road, Boron, Kern County, CA

  1. 6. Credit USAF, ca. 1947. Original housed in the Photograph ...

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

    6. Credit USAF, ca. 1947. Original housed in the Photograph Files, AFFTC/HO, Edwards AFB, California. Interior of Building 4401 (or possibly 4402) looking east at hangar doors with a North American Aviation XB-45 Tornado jet aircraft in the foreground. This view illustrates why the series of sliding doors and wide, high interior clearances were necessary to accommodate large aircraft. Note configuration of wooden trusses supporting the roof. - Edwards Air Force Base, North Base, Hangar No. 1, First & B Streets, Boron, Kern County, CA

  2. 7. Credit USAF, ca. 1952. Original housed in the Photograph ...

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

    7. Credit USAF, ca. 1952. Original housed in the Photograph Files, AFFTC/HO, Edwards AFB, California. Oblique aerial view of North Base AFFTC (Air Force Flight Test Center) looking west northwest. The flight line at the edge of Rogers Dry Lake appears in the foreground, served by the facility's four hangars. Temporary structures beyond the hangars were demolished later in the 1950s. The fence that formerly surrounded the swimming pool in earlier photos has been taken down. In the distance lies the Jet Propulsion Laboratory Edwards Test Station, in its pre-1953 configuration. - Edwards Air Force Base, North Base, North Base Road, Boron, Kern County, CA

  3. Prediction of Stereochemistry using Q2MM.

    PubMed

    Hansen, Eric; Rosales, Anthony R; Tutkowski, Brandon; Norrby, Per-Ola; Wiest, Olaf

    2016-05-17

    The standard method of screening ligands for selectivity in asymmetric, transition metal-catalyzed reactions requires experimental testing of hundreds of ligands from ligand libraries. This "trial and error" process is costly in terms of time as well as resources and, in general, is scientifically and intellectually unsatisfying as it reveals little about the underlying mechanism behind the selectivity. The accurate computational prediction of stereoselectivity in enantioselective catalysis requires adequate conformational sampling of the selectivity-determining transition state but has to be fast enough to compete with experimental screening techniques to be useful for the synthetic chemist. Although electronic structure calculations are accurate and general, they are too slow to allow for sampling or fast screening of ligand libraries. The combined requirements can be fulfilled by using appropriately fitted transition state force fields (TSFFs) that represent the transition state as a minimum and allow fast conformational sampling using Monte Carlo. Quantum-guided molecular mechanics (Q2MM) is an automated force field parametrization method that generates accurate, reaction-specific TSFFs by fitting the functional form of an arbitrary force field using only electronic structure calculations by minimization of an objective function. A key feature that distinguishes the Q2MM method from many other automated parametrization procedures is the use of the Hessian matrix in addition to geometric parameters and relative energies. This alleviates the known problems of overfitting of TSFFs. After validation of the TSFF by comparison to electronic structure results for a test set and available experimental data, the stereoselectivity of a reaction can be calculated by summation over the Boltzman-averaged relative energies of the conformations leading to the different stereoisomers. The Q2MM method has been applied successfully to perform virtual ligand screens on a range of

  4. The new 800mm reflecting telescope

    NASA Astrophysics Data System (ADS)

    Teske, Hans-Joachim

    The design and capabilities of the 800-mm Ritchey-Chretien system are described. The optical system of the telescope has an aperture ratio of 1:8; is suitable for photography in a 1.5 deg field with photoplates of 16 x 16 cm; and consists of primary and secondary hyperbolically deformed mirrors. The attachment of the mirrors, position rotator, and offset guider to the tube, which is a truss structure, is examined. The mount for the telescope is an equatorial fork type. The electronic control system is a 16-bit microcomputer system; the functions of the control system are discussed. The 8-m polyester dome of the telescope consists of a supporting steel structure carrying shell elements of glass fiber-reinforced polyester resins. Consideration is given to the auxiliary devices of the telescope.

  5. Prediction of Stereochemistry using Q2MM

    PubMed Central

    2016-01-01

    Conspectus The standard method of screening ligands for selectivity in asymmetric, transition metal-catalyzed reactions requires experimental testing of hundreds of ligands from ligand libraries. This “trial and error” process is costly in terms of time as well as resources and, in general, is scientifically and intellectually unsatisfying as it reveals little about the underlying mechanism behind the selectivity. The accurate computational prediction of stereoselectivity in enantioselective catalysis requires adequate conformational sampling of the selectivity-determining transition state but has to be fast enough to compete with experimental screening techniques to be useful for the synthetic chemist. Although electronic structure calculations are accurate and general, they are too slow to allow for sampling or fast screening of ligand libraries. The combined requirements can be fulfilled by using appropriately fitted transition state force fields (TSFFs) that represent the transition state as a minimum and allow fast conformational sampling using Monte Carlo. Quantum-guided molecular mechanics (Q2MM) is an automated force field parametrization method that generates accurate, reaction-specific TSFFs by fitting the functional form of an arbitrary force field using only electronic structure calculations by minimization of an objective function. A key feature that distinguishes the Q2MM method from many other automated parametrization procedures is the use of the Hessian matrix in addition to geometric parameters and relative energies. This alleviates the known problems of overfitting of TSFFs. After validation of the TSFF by comparison to electronic structure results for a test set and available experimental data, the stereoselectivity of a reaction can be calculated by summation over the Boltzman-averaged relative energies of the conformations leading to the different stereoisomers. The Q2MM method has been applied successfully to perform virtual ligand

  6. mm-wave solid state amplifiers

    NASA Astrophysics Data System (ADS)

    Wolfert, P. H.; Crowley, J. D.; Fank, F. B.

    The development of mm-wave amplifiers using InP Gunn diodes is reviewed including a low-noise eight-stage amplifier for replacement of a Ka-band TWTA and a three-stage amplifier for the 42.5 to 44.5 range with an output power of 100 mW and 20 dB associated gain. A detailed description of a three-stage amplifier for the 54 to 58 GHz range is given with 100 mW output power and 15 dB associated gain, a small signal gain of 30 dB and an N.F. of 15.5 to 16.5 dB. The design of a broad band, low-loss V-band circulator, which was used in the amplifier, is described.

  7. Ho:YLF pumped HBr laser.

    PubMed

    Botha, L R; Bollig, C; Esser, M J D; Campbell, R N; Jacobs, C; Preussler, D R

    2009-10-26

    A Ho:YLF laser pumped HBr molecular laser was developed that produced up to 2.5 mJ of energy in the 4 micron wavelength region. The Ho:YLF laser was fiber pumped using a commercial Tm:fibre laser. The Ho:YLF laser was operated in a single longitudinal mode via injection seeding with a narrow band diode laser which in turn was locked to one of the HBr transitions. The behavior of the HBr laser was described using a rate equation mathematical model and this was solved numerically. Good agreement both qualitatively and quantitatively between the model and experimental results was obtained. PMID:19997290

  8. Isoflurane inhibits synaptic vesicle exocytosis through reduced Ca2+ influx, not Ca2+-exocytosis coupling

    PubMed Central

    Baumgart, Joel P.; Zhou, Zhen-Yu; Hara, Masato; Cook, Daniel C.; Hoppa, Michael B.; Ryan, Timothy A.; Hemmings, Hugh C.

    2015-01-01

    Identifying presynaptic mechanisms of general anesthetics is critical to understanding their effects on synaptic transmission. We show that the volatile anesthetic isoflurane inhibits synaptic vesicle (SV) exocytosis at nerve terminals in dissociated rat hippocampal neurons through inhibition of presynaptic Ca2+ influx without significantly altering the Ca2+ sensitivity of SV exocytosis. A clinically relevant concentration of isoflurane (0.7 mM) inhibited changes in [Ca2+]i driven by single action potentials (APs) by 25 ± 3%, which in turn led to 62 ± 3% inhibition of single AP-triggered exocytosis at 4 mM extracellular Ca2+ ([Ca2+]e). Lowering external Ca2+ to match the isoflurane-induced reduction in Ca2+ entry led to an equivalent reduction in exocytosis. These data thus indicate that anesthetic inhibition of neurotransmitter release from small SVs occurs primarily through reduced axon terminal Ca2+ entry without significant direct effects on Ca2+-exocytosis coupling or on the SV fusion machinery. Isoflurane inhibition of exocytosis and Ca2+ influx was greater in glutamatergic compared with GABAergic nerve terminals, consistent with selective inhibition of excitatory synaptic transmission. Such alteration in the balance of excitatory to inhibitory transmission could mediate reduced neuronal interactions and network-selective effects observed in the anesthetized central nervous system. PMID:26351670

  9. Isoflurane inhibits synaptic vesicle exocytosis through reduced Ca2+ influx, not Ca2+-exocytosis coupling.

    PubMed

    Baumgart, Joel P; Zhou, Zhen-Yu; Hara, Masato; Cook, Daniel C; Hoppa, Michael B; Ryan, Timothy A; Hemmings, Hugh C

    2015-09-22

    Identifying presynaptic mechanisms of general anesthetics is critical to understanding their effects on synaptic transmission. We show that the volatile anesthetic isoflurane inhibits synaptic vesicle (SV) exocytosis at nerve terminals in dissociated rat hippocampal neurons through inhibition of presynaptic Ca(2+) influx without significantly altering the Ca(2+) sensitivity of SV exocytosis. A clinically relevant concentration of isoflurane (0.7 mM) inhibited changes in [Ca(2+)]i driven by single action potentials (APs) by 25 ± 3%, which in turn led to 62 ± 3% inhibition of single AP-triggered exocytosis at 4 mM extracellular Ca(2+) ([Ca(2+)]e). Lowering external Ca(2+) to match the isoflurane-induced reduction in Ca(2+) entry led to an equivalent reduction in exocytosis. These data thus indicate that anesthetic inhibition of neurotransmitter release from small SVs occurs primarily through reduced axon terminal Ca(2+) entry without significant direct effects on Ca(2+)-exocytosis coupling or on the SV fusion machinery. Isoflurane inhibition of exocytosis and Ca(2+) influx was greater in glutamatergic compared with GABAergic nerve terminals, consistent with selective inhibition of excitatory synaptic transmission. Such alteration in the balance of excitatory to inhibitory transmission could mediate reduced neuronal interactions and network-selective effects observed in the anesthetized central nervous system. PMID:26351670

  10. Mechanisms of enhanced taurine release under Ca2+ depletion.

    PubMed

    Molchanova, Svetlana M; Oja, Simo S; Saransaari, Pirjo

    2005-10-01

    The sulfur-containing amino acid taurine is an inhibitory neuromodulator in the brain of mammals, as well as a key substance in the regulation of cell volumes. The effect of Ca(2+) on extracellular taurine concentrations is of special interest in the context of the regulatory mechanisms of taurine release. The aim of this study was to characterize the basal release of taurine in Ca(2+)-free medium using in vivo microdialysis of the striatum of anesthetized rats. Perfusion of Ca(2+)-free medium via a microdialysis probe evoked a sustained release of taurine (up to 180 % compared to the basal levels). The Ca(2+) chelator EGTA (1mM) potentiated Ca(2+) depletion-evoked taurine release. The substitution of CaCl(2) by choline chloride did not alter the observed effect. Ca(2+)-free solution did not significantly evoke release of taurine from tissue loaded with the competitive inhibitor of taurine transporter guanidinoethanesulfonate (1mM), suggesting that in Ca(2+) depletion taurine is released by the transporter operating in the outward direction. The volume-sensitive chloride channel blocker diisothiocyanostilbene-2,2'-disulfonate (1mM) did not attenuate the taurine release evoked by Ca(2+) depletion. The non-specific blocker of voltage-sensitive Ca(2+) channels NiCl(2) (0.65 mM) enhanced taurine release in the presence of Ca(2+). CdCl(2) (0.25 mM) had no effect under these conditions. However, both CdCl(2) and NiCl(2) attenuated the effect of Ca(2+)-free medium on the release of taurine. The data obtained imply the involvement of both decreased influx of Ca(2+) and increased non-specific influx of Na(+) through voltage-sensitive calcium channels in the regulation of transporter-mediated taurine release in Ca(2+) depletion. PMID:15982785

  11. Ca/sup 2 +/ and glucose uptake in adipocytes: evidence for biological activity of a Ca/sup 2 +/-palmitate complex

    SciTech Connect

    Thode, J.; Pershadsingh, H.A.; Shade, D.L.; McDonald, J.M.; Ladenson, J.H.

    1986-05-01

    A tightly bound form of Ca/sup 2 +/ in serum, thought to be a Ca/sup 2 +/-fatty acid complex, has been reported to cause accelerated Ca/sup 2 +/ uptake in bone cells. The authors therefore studied the effect of palmitic acid on Ca/sup 2 +/ accumulation and its influence on glucose transport in adipocytes. They assessed /sup 45/Ca/sup 2 +/ and /sup 14/C-D-glucose uptake into rat adipocytes from solutions containing: 4% (w/v) fatty acid-free albumin, 2.5 mM CaCl/sub 2/ (free (Ca/sup 2 +/)=1.30 mM), 140 mM NaCl, 3 mM Na phosphate, 1.4 mM MgSO/sub 4/, 5 mM D-glucose, 5 mM HEPES, pH 7.4 at 37/sup 0/C with and without 4 mM palmitate. Ca/sup 2 +/ was taken up by both rapid (< 30 sec), and slow (reaching steady state within 20 min) cellular accumulation phases. Palmitate increased the rapid binding phase of /sup 45/Ca/sup 2 +/ uptake from 2.10 +/- 0.13 to 3.03 +/- 0.16 fmol Ca/sup 2 +//cell and caused a 2 to 3-fold increase in the slow phase. Palmitate also increased glucose uptake by a mean of 225% above control. This increase was eliminated by a 15 min preincubation with the intracellular Ca/sup 2 +/ chelator, quin 2-AM (50 ..mu..M), implying that increased Ca/sup 2 +/ uptake was related to increased glucose transport. They conclude that the Ca/sup 2 +/-palmitate complex enhances Ca/sup 2 +/ uptake, which may be related to an increased ability for adipocytes to transport glucose. The Ca/sup 2 +/-palmitate complex may therefore represent a biologically active form of Ca/sup 2 +/.

  12. Local Measurement of Tropospheric HO(x)

    NASA Technical Reports Server (NTRS)

    Crosley, David R.

    1994-01-01

    In March of 1992 a workshop sponsored by NASA and NSF was held at SRI International to assess the current ability to measure atmospheric OH and HO2. The measurement techniques reviewed during the workshop for detection of OH included five laser-induced fluorescence schemes, five laser-based adsorption techniques, and four non-laser methods. Six instruments or instrument concepts for HO2 detection, including chemical amplification, conversion to OH with subsequent OH detection, or direct spectroscopic detection of the HO2 were also discussed. The conclusions from the workshop identify several measurement techniques for OH and HO2 that are ready for field tests. These have the ability to measure the radicals with sufficient sensitivity and accuracy to form meaningful comparison with atmospheric model predictions. The workshop conclusions also include recommendations for informal and formal intercomparison protocols.

  13. Low-Friction Minilaparoscopy Outperforms Regular 5-mm and 3-mm Instruments for Precise Tasks

    PubMed Central

    Firme, Wood A.; Lima, Diego L.; de Paula Lopes, Vladmir Goldstein; Montandon, Isabelle D.; Filho, Flavio Santos; Shadduck, Phillip P.

    2015-01-01

    Background and Objectives: Therapeutic laparoscopy was incorporated into surgical practice more than 25 y ago. Several modifications have since been developed to further minimize surgical trauma and improve results. Minilaparoscopy, performed with 2- to 3-mm instruments was introduced in the mid 1990s but failed to attain mainstream use, mostly because of the limitations of the early devices. Buoyed by a renewed interest, new generations of mini instruments are being developed with improved functionality and durability. This study is an objective evaluation of a new set of mini instruments with a novel low-friction design. Method: Twenty-two medical students and 22 surgical residents served as study participants. Three designs of laparoscopic instruments were evaluated: conventional 5 mm, traditional 3 mm, and low-friction 3 mm. The instruments were evaluated with a standard surgical simulator, emulating 4 exercises of various complexities, testing grasping, precise 2-handed movements, and suturing. The metric measured was time to task completion, with 5 replicates for every combination of instrument–exercise–participant. Results: For all 4 tasks, the instrument design that performed the best was the same in both the medical student and surgical resident groups. For the gross-grasping task, the 5-mm conventional instruments performed best, followed by the low-friction mini instruments. For the 3 more complex and precise tasks, the low-friction mini instruments outperformed both of the other instrument designs. Conclusion: In standard surgical simulator exercises, low-friction minilaparoscopic instruments outperformed both conventional 3- and 5-mm laparoscopic instruments for precise tasks. PMID:26390530

  14. A comparison of 9-inch, 70mm, and 35mm cameras

    NASA Technical Reports Server (NTRS)

    Clegg, R. H.; Scherz, J. P.

    1975-01-01

    Successful aerial photography depends on aerial cameras that provide acceptable photographs within the cost restrictions of the job. For topographic mapping where ultimate accuracy is required, only large-format mapping cameras will suffice. For mapping environmental patterns of vegetation, soils, or water pollution, 9-inch cameras often exceed accuracy and cost requirements, and small formats may be an overall better choice. In choosing the best camera for environmental mapping, relative capabilities and costs must be understood. This study compares resolution, photo interpretation potential, metric accuracy, and cost of 9-inch, 70 mm, and 35 mm cameras for obtaining simultaneous color and color-infrared photography for environmental mapping purposes.

  15. Energy levels of HoBr 63-

    NASA Astrophysics Data System (ADS)

    Tanner, Peter A.

    1986-12-01

    The excitation, electronic absorption and luminescence spectra of cubic Cs 2NaHoBr 6 have been recorded at temperatures down to that of liquid helium. The detailed spectral analyses enable comparisons to be made of the crystal-field splittings of Russell—Saunders terms with those in Cs 2NaHoCl 6. Under intense 647.1 nm laser excitation, luminescence is observed in the neat material in the spectral region between 17800 and 21750 cm -1.

  16. Ho:YAG laser arthroscopy of the knee

    NASA Astrophysics Data System (ADS)

    Sisto, Domenick J.; Blazina, Martin E.; Hirsh, Linda C.

    1994-09-01

    The HO:YAG laser is a near-contact laser with a capacity to ablate or cut tissues. The ablation function allows the surgeon to remove meniscal tissue, lyse and resect adhesions, melt loose bodies, and dissolve inflamed synovium. The cutting function of the laser is utilized to perform a lateral release or resect torn menisci. The laser can also be utilized to drill holes in Grade IV chondromalacic lesions to initiate a healing response. The laser has been embraced by orthopaedic surgeons because of its shape and versatility. The tip is only 2 mm wide and can be delivered into the tight posterior compartments of the knee with no damaging contact with the articular surfaces. The laser coagulates as it works and bleeding is minimized. The laser can function both as a cutting and ablating tool. The laser can also drill holes into subchondral bone to, hopefully, initiate a healing response.

  17. Spectroscopic properties and upconversion studies in Ho(3+) /Yb(3+) Co-doped calcium scandate with spectrally pure green emission.

    PubMed

    Li, Jing; Zhang, Jiahua; Hao, Zhendong; Zhang, Xia; Zhao, Jihong; Luo, Yongshi

    2013-12-16

    The optical properties of a Ho(3+) /Yb(3+) co-doped CaSc2 O4 oxide material are investigated in detail. The spectral properties are described as a function of doping concentrations. The efficient Yb(3+) →Ho(3+) energy transfer is observed. The transfer efficiency approaches 50 % before concentration quenching. The concentration-optimized sample exhibits a strong green emission accompanied with a weak red emission, showing perfect green monochromaticity. The results of the spectral distribution, power dependence, and lifetime measurements are presented. The green, red, and near-infrared (NIR) emissions around 545, 660, and 759 nm are assigned to the (5) F4 +(5) S2 →(5) I8 , (5) F5 →(5) I8 , and (5) F4 +(5) S2 →(5) I7 transitions of Ho(3+) , respectively. The detailed study reveals the upconversion luminescence mechanism involved in a novel Ho(3+) /Yb(3+) co-doped CaSc2 O4 oxide material. PMID:24323855

  18. Voltage-gated Ca2+ entry and ryanodine receptor Ca2+-induced Ca2+ release in preglomerular arterioles.

    PubMed

    Fellner, Susan K; Arendshorst, William J

    2007-05-01

    We have previously shown that in afferent arterioles, angiotensin II (ANG II) involves activation of the inositol trisphosphate receptor (IP(3)R), activation of adenine diphosphoribose (ADPR) cyclase, and amplification of the initial IP(3)R-stimulated release of cytosolic Ca(2+) ([Ca(2+)](i)) from the sarcoplasmic reticulum (SR) (Fellner SK, Arendshorst WJ. Am J Physiol Renal Physiol 288: F785-F791, 2004). The response of the ryanodine receptor (RyR) to local increases in [Ca(2+)](i) is defined as calcium-induced calcium release (CICR). To investigate whether Ca(2+) entry via voltage-gated channels (VGCC) can stimulate CICR, we treated fura 2-loaded, freshly isolated afferent arterioles with KCl (40 mM; high KCl). In control arterioles, peak [Ca(2+)](i) increased by 165 +/- 10 nM. Locking the RyR in the closed position with ryanodine (100 microM) inhibited the [Ca(2+)](i) response by 59% (P < 0.01). 8-Br cADPR, a specific blocker of the ability of cyclic ADPR (cADPR) to sensitize the RyR to Ca(2+), caused a 43% inhibition. We suggest that the lower inhibition by 8-Br cADPR (P = 0.02, ryanodine vs. 8-Br cADPR) represents endogenously active ADPR cyclase. Depletion of SR Ca(2+) stores by inhibiting the SR Ca(2+)-ATPase with cyclopiazonic acid or thapsigargin blocked the [Ca(2+)](i) responses to KCl by 51% (P not significant vs. ryanodine or 8-Br cADPR). These data suggest that about half of the increase in [Ca(2+)](i) induced by high KCl is accomplished by activation of CICR through the ability of entered Ca(2+) to expose the RyR to high local concentrations of Ca(2+) and that endogenous cADPR contributes to the process. PMID:17190906

  19. 75 FR 52534 - Su Van Ho: Debarment Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-26

    ... Salmonella bacteria, with verification of such exportation or destruction by FDA. Mr. Ho concealed and... with Salmonella bacteria. As a result of his conviction, on June 10, 2010, FDA sent Mr. Ho a notice...

  20. Detection of Ca(2+)-binding proteins by electrophoretic migration in the presence of Ca2+ combined with 45Ca2+ overlay of protein blots

    SciTech Connect

    Garrigos, M.; Deschamps, S.; Viel, A.; Lund, S.; Champeil, P.; Moller, J.V.; le Maire, M. , Gif-sur-Yvette )

    1991-04-01

    When high affinity Ca(2+)-binding proteins like calmodulin, or proteins with a high Ca(2+)-binding capacity like calsequestrin, underwent sodium dodecyl sulfate-gel electrophoresis in Laemmli systems, their electrophoretic migration rates were much higher in gels containing 1 mM Ca2+ than in gels containing ethylene glycol bis(beta-aminoethyl ether) N,N{prime}-tetraacetic acid (EGTA). Replacement of EGTA by Ca2+ in the gel, combined with the blotting of electrophoretically separated proteins on polyvinylidene difluoride membranes and subsequent 45Ca2+ overlay, proved a very effective means of detecting Ca(2+)-binding proteins. This combined approach is important since artifacts occur in both techniques when used separately. We found that the usual procedure of adding Ca2+ to the sample before electrophoresis without including it in the gel itself permitted the detection of only very high affinity Ca(2+)-binding proteins.

  1. Planetary brightness temperature measurements at 8.6 mm and 3.1 mm wavelengths.

    NASA Technical Reports Server (NTRS)

    Ulich, B. L.; Cogdell, J. R.; Davis, J. H.

    1973-01-01

    New measurements of the sun, moon, Mercury, Venus, Mars, Jupiter, and Saturn at 3.1- and 8.6-mm wavelengths are given. The temperatures reported for the planets at 3.1-mm wavelength are higher than previous measurements in this wavelength range and change the interpretation of some planetary spectra. For Mercury, it is found that the mean brightness temperature is independent of wavelength and that a temperature-dependent thermal conductivity is not required to match the observations. In the case of Mars, the spectrum is shown to rise in the millimeter region, as simple models predict. For Jupiter, the need to recalculate the spectrum with recent models is demonstrated. The flux density scale proposed by Dent (1972) has been revised according to a more accurate determination of the millimeter brightness temperature of Jupiter.

  2. Oxidized CaMKII Triggers Atrial Fibrillation

    PubMed Central

    Purohit, Anil; Rokita, Adam G.; Guan, Xiaoqun; Chen, Biyi; Koval, Olha M.; Voigt, Niels; Neef, Stefan; Sowa, Thomas; Gao, Zhan; Luczak, Elizabeth D.; Stefansdottir, Hrafnhildur; Behunin, Andrew C.; Li, Na; El-Accaoui, Ramzi N.; Yang, Baoli; Swaminathan, Paari Dominic; Weiss, Robert M.; Wehrens, Xander H.T.; Song, Long-Sheng; Dobrev, Dobromir; Maier, Lars S.; Anderson, Mark E.

    2013-01-01

    Background Atrial fibrillation is a growing public health problem without adequate therapies. Angiotensin II (Ang II) and reactive oxygen species (ROS) are validated risk factors for atrial fibrillation (AF) in patients, but the molecular pathway(s) connecting ROS and AF is unknown. The Ca2+/calmodulin-dependent protein kinase II (CaMKII) has recently emerged as a ROS activated proarrhythmic signal, so we hypothesized that oxidized CaMKIIδ(ox-CaMKII) could contribute to AF. Methods and Results We found ox-CaMKII was increased in atria from AF patients compared to patients in sinus rhythm and from mice infused with Ang II compared with saline. Ang II treated mice had increased susceptibility to AF compared to saline treated WT mice, establishing Ang II as a risk factor for AF in mice. Knock in mice lacking critical oxidation sites in CaMKIIδ (MM-VV) and mice with myocardial-restricted transgenic over-expression of methionine sulfoxide reductase A (MsrA TG), an enzyme that reduces ox-CaMKII, were resistant to AF induction after Ang II infusion. Conclusions Our studies suggest that CaMKII is a molecular signal that couples increased ROS with AF and that therapeutic strategies to decrease ox-CaMKII may prevent or reduce AF. PMID:24030498

  3. 1. West portal of Tunnel 36, view to northeast, 135mm ...

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

    1. West portal of Tunnel 36, view to northeast, 135mm lens. Note the notched wingwalls that originally held timber posts of the original timber snowsheds, miles of which once enclosed and protected the railroad from the ravages of Sierra winters. Note also that these tunnels, built in the 1920s, have dispensed with any use of stone masonry, and instead have all-concrete portals. - Central Pacific Transcontinental Railroad, Tunnel No. 36, Milepost 176.92, Yuba Pass, Nevada County, CA

  4. System performance advances of 18-mm and 16-mm subminiature image intensifier sensors

    NASA Astrophysics Data System (ADS)

    Thomas, Nils I.

    2000-11-01

    Night vision system design has been centered aroudn the An/AVS-6 and AN/PVS-7 night vision goggle systems for the past 20 years. Goggle performance has improved during this time through increased performance of the image intensifier sensor, primarily the Omni IV sensor from ITT Industries Night Vision. Most of this improvement has been at the optimal light level (1E-3 fc scene illumination). Recent advances in image sensor performance from the filmless Generation (Gen) IV sensors has increased the low light level performance of night vision devices from 0.3 cy/mr to 0.7 cy/mr. In addition, sensor packaging design requirements have forced night vision sensor manufactures to design light weight, small volume sensors. ITT recently has designed such a sensor in a 16-mm format. This sensor if 50% lighter, up to 50% shorter, and has design features that simplify the objective lens design. New night vision goggles have been, and are being, designed which reduce the perceived head-supported weight. This paper presents signal-to-noise ratio, halo, and other film-less sensor data and similar 16-mm subminiature sensor data. The resulting system performance data will be described. Finally, the system design improvements and relationships with the subminiature 16-mm subminiature sensor will be given.

  5. Ca2+-Dependent Regulation of Ca2+ Currents in Rat Primary Afferent Neurons: Role of CaMKII and the Effect of Injury

    PubMed Central

    Tang, Qingbo; Bangaru, Madhavi Latha Yadav; Kostic, Sandra; Pan, Bin; Wu, Hsiang-En; Koopmeiners, Andrew S.; Yu, Hongwei; Fischer, Gregory J.; McCallum, J. Bruce; Kwok, Wai-Meng; Hudmon, Andy

    2012-01-01

    Currents through voltage-gated Ca2+ channels (ICa) may be regulated by cytoplasmic Ca2+ levels ([Ca2+]c), producing Ca2+-dependent inactivation (CDI) or facilitation (CDF). Since ICa regulates sensory neuron excitability, altered CDI or CDF could contribute to pain generation after peripheral nerve injury. We explored this by manipulating [Ca2+]c while recording ICa in rat sensory neurons. In uninjured neurons, elevating [Ca2+]c with a conditioning prepulse (−15 mV, 2 s) inactivated ICa measured during subsequent test pulses (−15 mV, 5 ms). This inactivation was Ca2+-dependent (CDI), since it was decreased with elimination of Ca2+ influx by depolarization to above the ICa reversal potential, with high intracellular Ca2+ buffering (EGTA 10 mm or BAPTA 20 mm), and with substitution of Ba2+ for extracellular Ca2+, revealing a residual voltage-dependent inactivation. At longer latencies after conditioning (>6 s), ICa recovered beyond baseline. This facilitation also proved to be Ca2+-dependent (CDF) using the protocols limiting cytoplasmic Ca2+ elevation. Ca2+/calmodulin-dependent protein kinase II (CaMKII) blockers applied by bath (KN-93, myristoyl-AIP) or expressed selectively in the sensory neurons (AIP) reduced CDF, unlike their inactive analogues. Protein kinase C inhibition (chelerythrine) had no effect. Selective blockade of N-type Ca2+ channels eliminated CDF, whereas L-type channel blockade had no effect. Following nerve injury, CDI was unaffected, but CDF was eliminated in axotomized neurons. Excitability of sensory neurons in intact ganglia from control animals was diminished after a similar conditioning pulse, but this regulation was eliminated by injury. These findings indicate that ICa in sensory neurons is subject to both CDI and CDF, and that hyperexcitability following injury-induced loss of CDF may result from diminished CaMKII activity. PMID:22915116

  6. Highly efficient high power CW and Q-switched Ho:YLF laser

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, J.

    2015-06-01

    An efficient operation of a Ho:YLF laser pumped by a Tm-doped fibre laser is reported. The research in a continuous-wave (CW) operation was done for two crystals of the same 0.5 at.%Ho dopant concentration and with different lengths (3×3×30 mm3 and 3×3×50 mm3). For an output coupling transmission of 20% and a crystal length of 50 mm, the maximum CWoutput power of 38.9 W for 81.4 W of incident pump power, corresponding to the slope efficiency of 52.3% and optical-to-optical conversion efficiency of 47.8% (determined with respect to the incident pump power) was achieved. The highest opti- cal-to-optical conversion efficiency of 70.2% with respect to the absorbed pump power was obtained. The influence of a heat-sink cooling water temperature on theCWlaser performance was studied. For a Q-switched operation the pulse repe- tition frequency (PRF) was changed from 2 to 10 kHz. The maximum average output power of 34.1 W at the PRF of 10 kHz was obtained for a 50 mm holmium crystal length. For 2 kHz PRF and 71.9 W of incident pump power, pulse energies of 13.7 mJ with a 21 ns FWHM pulse width corresponding to 652 kW peak power were recorded.

  7. Multimodality of Ca2+ signaling in rat atrial myocytes.

    PubMed

    Morad, Martin; Javaheri, Ashkan; Risius, Tim; Belmonte, Steve

    2005-06-01

    It has been suggested that the multiplicity of Ca(2+) signaling pathways in atrial myocytes may contribute to the variability of its function. This article reports on a novel Ca(2+) signaling cascade initiated by mechanical forces induced by "puffing" of solution onto the myocytes. Ca(i) transients were measured in fura-2 acetoxymethyl (AM) loaded cells using alternating 340- and 410-nm excitation waves at 1.2 kHz. Pressurized puffs of bathing solutions, applied by an electronically controlled micro-barrel system, activated slowly (approximately 300 ms) developing Ca(i) transients that lasted 1,693 +/- 68 ms at room temperature. Subsequent second and third puffs, applied at approximately 20 s intervals activated significantly smaller or no Ca(i) transients. Puff-triggered Ca(i) transients could be reactivated once again following caffeine (10 mM)-induced release of Ca(2+) from sarcoplasmic reticulum (SR). Puff-triggered Ca(i) transients were independent of [Ca(2+)](o), and activation of voltage-gated Ca(2+) or cationic stretch channels or influx of Ca(2+) on Na(+)/Ca(2+)exchanger, because puffing solution containing no Ca(2+), 10 microM diltiazem, 1 mM Cd(2+), 5 mM Ni(2+), or 100 microM Gd(3+) failed to suppress them. Puff-triggered Ca(i) transients were enhanced in paced compared to quiescent myocytes. Electrically activated Ca(i) transients triggered during the time course of puff-induced transients were unaltered, suggesting functionally separate Ca(2+) pools. Contribution of inositol 1,4,5-triphosphate (IP(3))-gated or mitochondrial Ca(2+) pools or modulation of SR stores by nitric oxide/nitric oxide synthase (NO/NOS) signaling were evaluated using 0.5 to 500 microM 2-aminoethoxydiphenyl borate (2-APB) and 0.1 to 1 microM carbonylcyanide-p-trifluoromethoxyphenylhydrazone (FCCP), and 1 mM Nomega-Nitro-L-arginine methyl ester (L-NAME) and 7-nitroindizole, respectively. Only FCCP appeared to significantly suppress the puff-triggered Ca(i) transients. It was

  8. Cytoprotective responses in HaCaT keratinocytes exposed to high doses of curcumin.

    PubMed

    Lundvig, Ditte M S; Pennings, Sebastiaan W C; Brouwer, Katrien M; Mtaya-Mlangwa, Matilda; Mugonzibwa, Emeria; Kuijpers-Jagtman, Anne Marie; Wagener, Frank A D T G; Von den Hoff, Johannes W

    2015-08-15

    Wound healing is a complex process that involves the well-coordinated interactions of different cell types. Topical application of high doses of curcumin, a plant-derived polyphenol, enhances both normal and diabetic cutaneous wound healing in rodents. For optimal tissue repair interactions between epidermal keratinocytes and dermal fibroblasts are essential. We previously demonstrated that curcumin increased reactive oxygen species (ROS) formation and apoptosis in dermal fibroblasts, which could be prevented by pre-induction of the cytoprotective enzyme heme oxygenase (HO)-1. To better understand the effects of curcumin on wound repair, we now assessed the effects of high doses of curcumin on the survival of HaCaT keratinocytes and the role of the HO system. We exposed HaCaT keratinocytes to curcumin in the presence or absence of the HO-1 inducers heme (FePP) and cobalt protoporphyrin (CoPP). We then assessed cell survival, ROS formation, and caspase activation. Curcumin induced caspase-dependent apoptosis in HaCaT keratinocytes via a ROS-dependent mechanism. Both FePP and CoPP induced HO-1 expression, but only FePP protected against curcumin-induced ROS formation and caspase-mediated apoptosis. In the presence of curcumin, FePP but not CoPP induced the expression of the iron scavenger ferritin. Together, our data show that the induction of ferritin, but not HO, protects HaCaT keratinocytes against cytotoxic doses of curcumin. The differential response of fibroblasts and keratinocytes to high curcumin doses may provide the basis for improving curcumin-based wound healing therapies. PMID:26071936

  9. Some Improvements in the Design of a CA/CV Moessbauer Velocity Drive

    SciTech Connect

    Seberini, Milan

    2008-10-28

    A constant velocity Moessbauer drive was built with velocity range {+-}15 mm/s and velocity resolution 0.005 mm/s. Based on good experience with its performance, a new universal CA/CV drive was designed. The new drive is supposed to have velocity range of {+-}80 mm/s with a velocity resolution below 0.002 mm/s.

  10. Presence of an HO-1 expression threshold in renal glomeruli

    PubMed Central

    Detsika, Maria G; Atsaves, Vassileios; Papalois, Apostolos; Lianos, Elias A.

    2015-01-01

    This article reports data describing HO-1 expression patterns of heme oxygenase (HO)-1 in isolated rat glomeruli and in cultured glomerular epithelial cells (GEC) in response to its natural substrate heme. Qualitative and quantitative data are presented to support presence of a HO-1 expression threshold in glomeruli but not in GEC. Interpretation of our data and further insight into HO-1 expression pattern in glomeruli may be found in ‘HO-1 expression control in the rat glomerulus’ [1]. PMID:26702422

  11. Ca isotope cycling in a forested ecosystem

    NASA Astrophysics Data System (ADS)

    Holmden, Chris; Bélanger, Nicolas

    2010-02-01

    Reports of large Ca isotope fractionations between trees and soils prompted this study of a Boreal forest ecosystem near La Ronge, Saskatchewan, to improve understanding of this phenomenon. The results on five tree species (black spruce, trembling aspen, white spruce, jack pine, balsam poplar) confirm that nutrient Ca uptake by plants favors the light isotopes, thus driving residual Ca in plant available soil pools towards enrichment in the heavy isotopes. Substantial within-tree fraction occurs in tissues formed along the transpiration stream, with low δ 44Ca values in fine roots (2 mm), intermediate values in stemwood, and high values in foliage. Separation factors between different plant tissues are similar between species, but the initial fractionation step in the tips of the fine roots is species specific, and/or sensitive to the local soil environment. Soil water δ 44Ca values appear to increase with depth to at least 35 cm below the top of the forest floor, which is close to the deepest level of fine roots. The heavy plant fractionated signature of Ca in the finely rooted upper soils filters downward where it is retained on ion exchange sites, leached into groundwater, and discharged into surface waters. The relationship between Ca uptake by tree fine roots and the pattern of δ 44Ca enrichment with soil depth was modeled for two Ca pools: the forest floor (litter) and the underlying (upper B) mineral soil. Six study plots were investigated along two hillside toposequences trending upwards from a first order stream. We used allometric equations describing the Ca distribution in boreal tree species to calculate weighted average δ 44Ca values for the stands in each plot and estimate Ca uptake rates. The δ 44Ca value of precipitation was measured, and soil weathering signatures deduced, by acid leaching of lower B mineral soils. Steady state equations were used to derive a set of model Ca fluxes and fractionation factors for each plot. The model reproduces

  12. The LLAMA 12 m mm/sub-mm radiotelescope in the Andes

    NASA Astrophysics Data System (ADS)

    Lepine, Jacques; Edemundo Arnal, Marcelo; de Graauw, Thijs; Abraham, Zulema; Gimenez de Castro, Guillermo; de Gouveia Dal Pino, Elisabete; Morras, Ricardo; Larrarte, Juan; Viramontes, José; Finger, Ricardo; Kooi, Jacob; Reeves, Rodrigo; Beaklini, Pedro

    2015-08-01

    LLAMA (Large Latin American Millimetric Array) is a joint Argentinean-Brazilian project of a 12m mm/sub-mm radio telescope similar to the APEX antenna, to be installed at a site at 4800 m altitude near San Antonio de Los Cobres in the Salta Province in Argentine, at 150 km from ALMA. The scientific cases for single dish and VLBI observations include black holes and accretion disks, the molecular evolution of interstellar clouds, the structure of the Galaxy, the formation of galaxies, and much more. The antenna was ordered to the company Vertex Antennentechnik in June 2014, and the construction is progressing quickly; it will be installed at the site in 2016. The radio telescope will be equipped with up to six receivers covering bands similar to those of ALMA. Cryostats with room for 3 cartridges, constructed by NAOJ (Tokyo,Japan), will be installed in each of the two Nasmyth cabins. Among the first receivers we will have an ALMA band 9 provided by NOVA (Groningen, Holland) and a band 5 from the Chalmers University (Sweden). Other receivers are still being discussed at the time of submission of this abstract,At high frequencies, VLBI observations at high frequencies could be made with ALMA, APEX and ASTE, and Northern radiotelescopes. In this way, LLAMA will be a seed for a Latin-American VLBI network.

  13. Sticking of HO2 on fatty acids aggregates

    NASA Astrophysics Data System (ADS)

    Vardanega, Delphine; Briquez, Stéphane; Duflot, Denis; Monnerville, Maurice; Toubin, Céline

    2015-04-01

    Models of atmospheric chemistry are widely used to perform projections of future changes in the chemical composition of the global troposphere, including changes in climate related greenhouse gases and aerosol particles. However, large uncertainties are still associated with the chemistry implemented in these models, which in turn can lead to inaccurate long-term predictions. The proposed work seeks to improve our understanding of the oxidative capacity of the atmosphere, which drives the lifetime of trace gases, and therefore atmospheric composition. Recent measurements [1] of free radicals made in forested environments characterized by low levels of nitrogen oxides (NOx = NO and NO2) indicate that current models of atmospheric chemistry tend to overestimate the concentration of peroxy radicals (HO2 and RO2). An overestimation of peroxy radicals is an important issue since these radicals are the main precursors of the hydroxyl radical (OH), the most important atmospheric oxidant during daytime. This issue could lead to a significant overestimation of the oxidative capacity of the global atmosphere since more than 86% of the Earth surface is covered by forests, oceans, and polar regions. An analysis of this dataset indicates that the missing sink could be due to an underestimation of the rates of RO2+HO2 reactions, and/or the uptake of peroxy radicals onto aerosol particles. A thorough evaluation of scientific studies published in the literature shows that there is a lack of kinetic and mechanistic data to correctly assess the contribution of these two loss pathways of peroxy radicals in low NOx environments. Classical molecular dynamics simulations, using the Gromacs package [2], are performed to study the interaction of HO2 with organic (carboxylic acid) aerosols. The effect of the presence of water molecules on the surface are also be investigated. These calculations provide theoretical values for observable quantities such as uptake and mass accommodation

  14. Teaching Evolutionary Mechanisms: Genetic Drift and M&M's.

    ERIC Educational Resources Information Center

    Staub, Nancy L.

    2002-01-01

    Describes a classroom activity that teaches the mechanism of genetic drift to undergraduates. Illustrates a number of concepts that are critical in developing evolution literacy by sampling M&M milk chocolate candies. (MM)

  15. AN ENZYME LINKED IMMUNOSORBENT ASSAY FOR THE HO-1 ISOFORM OF HEME OXYGENASE

    EPA Science Inventory

    AN ENZYME LINKED IMMUNOSORBENT ASSAY FOR THE HO-1 ISOFORM OF HEME OXYGENASE

    Heme oxygenase (HO) occurs in biological tissues as two major isoforms HO-1 and HO-2. HO-1 is inducible by many treatments, particularly oxidative stress-related conditions such as depletion of gl...

  16. Kinetics of the reaction HO2 + NO2 + M yields HO2NO2 + M

    NASA Technical Reports Server (NTRS)

    Sander, S. P.; Peterson, M. E.

    1984-01-01

    The flash photolysis/ultraviolet absorption technique was used to measure the rate constants for the reaction HO2 + NO2 + M yields HO2NO2 + M over the pressure range 50-700 torr and temperature range 229-362 K using He, O2, and N2 as diluent gases. The data were fit to the expression derived by Troe (1979) and co-workers for describing the pressure and temperature dependence of reactions in the falloff region. By combining these data with recent measurements of the rate constant for HO2NO2 thermal decomposition values of 73.8 + or - 2 eu for the standard entropy and -12.6 + or - kcal/mol for the standard enthalpy of formation of HO2NO2 were obtained. A significant enhancement in the rate constant was observed when water vapor was added to the system.

  17. Luminal Ca2+ promoting spontaneous Ca2+ release from inositol trisphosphate-sensitive stores in rat hepatocytes.

    PubMed Central

    Missiaen, L; Taylor, C W; Berridge, M J

    1992-01-01

    1. Spontaneous Ca2+ release from the inositol 1,4,5-trisphosphate (InsP3)-sensitive stores in permeabilized hepatocytes was monitored using Fluo-3 to measure the free [Ca2+] of the medium bathing the cells. 2. Permeabilized cells rapidly sequestered Ca2+, reducing the [Ca2+] to 103 +/- 5 nM. Under conditions that depended critically upon cell density and the amount of Ca2+ in the medium, this was followed by a slow increase in [Ca2+] culminating in a substantial Ca2+ spike representing synchronous discharge from the InsP3-sensitive stores. 3. During the latency preceding the Ca2+ spike, the stores increased their sensitivity to InsP3. This sensitization seemed to be an all-or-none phenomenon. 4. Oxidized glutathione and thimerosal promoted the spontaneous release by sensitizing the InsP3 receptor. 5. An increase in the [Ca2+] within the stores was required for both the increased sensitivity to InsP3 and the subsequent spike. 6. Caffeine (6 mM) antagonized the effect of very low InsP3 concentrations and abolished the Ca2+ spike, without itself releasing Ca2+. 7. Our results suggesting that luminal Ca2+ may sensitive InsP3-sensitive stores leading to spontaneous Ca2+ mobilization will be discussed in the light of a modified version of the two-pool model for explaining cytosolic Ca2+ oscillations. PMID:1484365

  18. New technique for prostatectomy using Ho:YAG laser

    NASA Astrophysics Data System (ADS)

    Daidoh, Yuichiro; Arai, Tsunenori; Murai, Masaru; Nakajima, Akio; Tsuji, Akira; Odajima, Kunio; Nakajima, Fumio; Kikuchi, Makoto; Nakamura, Hiroshi

    1994-05-01

    To develop a new transperineal laser prostatectomy through a biopsy needle, we determined the efficiency of a pulsed Nd:YAG laser irradiation for canine prostate. The Ho:YAG laser ((lambda) equals 2.1 micrometers ) may induced stress-wave to destroy the small vessels in prostate. After the exposure of the canine prostate, it was punctured by the needle. A quartz fiber of which core-diameter was 200 or 400 micrometers was inserted into the 18 G needle. The irradiation fluence was set to 150 - 600 J/cm2 and repetition rate was kept at 2 Hz. The cross-section of the irradiated portion of the prostate extracted immediately after the irradiation showed dark-colored hemorrhage layer around the ablation tract with 1 - 2 mm thickness. Some hemorrhage was histologically seen in stoma and gland in the irradiated prostate. In the case of 150 - 175 J/cm2 in the irradiation fluence, the irradiated portion of the prostate was found in the wedge-shaped area with brown color at one week after the irradiation. The lymphocytes infiltrating into the wedge-shaped zone were found. The wedge- shaped zone spread over the prostate and the change of urethral mucosa was minimum at one month after the irradiation. In the case of 500 - 600 J/cm2 irradiation, the paraurethral cavity was made at one month after the irradiation. The histological examination showed that the hemorrhage and subsequent histological changes may be caused by the laser induced stress-wave rather than thermal effect. Our results suggest that transperineal irradiation of pulsed Ho:YAG might offer an effective treatment for benign prostatic hyperplasia with the minimal damage to the urethral mucosa.

  19. Sporadic Creutzfeldt-Jakob Disease MM1+2C and MM1 are Identical in Transmission Properties.

    PubMed

    Kobayashi, Atsushi; Matsuura, Yuichi; Iwaki, Toru; Iwasaki, Yasushi; Yoshida, Mari; Takahashi, Hitoshi; Murayama, Shigeo; Takao, Masaki; Kato, Shinsuke; Yamada, Masahito; Mohri, Shirou; Kitamoto, Tetsuyuki

    2016-01-01

    The genotype (methionine, M or valine, V) at polymorphic codon 129 of the PRNP gene and the type (1 or 2) of abnormal prion protein in the brain are the major determinants of the clinicopathological features of sporadic Creutzfeldt-Jakob disease (CJD), thus providing molecular basis for classification of sporadic CJD, that is, MM1, MM2, MV1, MV2, VV1 or VV2. In addition to these "pure" cases, "mixed" cases presenting mixed neuropathological and biochemical features have also been recognized. The most frequently observed mixed form is the co-occurrence of MM1 and MM2, namely MM1+2. However, it has remained elusive whether MM1+2 could be a causative origin of dura mater graft-associated CJD (dCJD), one of the largest subgroups of iatrogenic CJD. To test this possibility, we performed transmission experiments of MM1+2 prions and a systematic neuropathological examination of dCJD patients in the present study. The transmission properties of the MM1+2 prions were identical to those of MM1 prions because MM2 prions lacked transmissibility. In addition, the neuropathological characteristics of MM2 were totally absent in dCJD patients examined. These results suggest that MM1+2 can be a causative origin of dCJD and causes neuropathological phenotype similar to that of MM1. PMID:25851836

  20. HO-1/CO system in tumor growth, angiogenesis and metabolism - Targeting HO-1 as an anti-tumor therapy.

    PubMed

    Loboda, Agnieszka; Jozkowicz, Alicja; Dulak, Jozef

    2015-11-01

    Heme oxygenase-1 (HO-1, hmox-1) catalyzes the rate-limiting step in the heme degradation processes. Out of three by-products of HO-1 activity, biliverdin, iron ions and carbon monoxide (CO), the latter was mostly shown to mediate many beneficial HO-1 effects, including protection against oxidative injury, regulation of apoptosis, modulation of inflammation as well as contribution to angiogenesis. Mounting evidence suggests that HO-1/CO systemmay be of special benefit in protection inmany pathological conditions, like atherosclerosis or myocardial infarction. By contrast, the augmented expression of HO-1 in tumor tissues may have detrimental effect as HO-1 accelerates the formation of tumor neovasculature and provides the selective advantage for tumor cells to overcome the increased oxidative stress during tumorigenesis and during treatment. The inhibition of HO-1 has been proposed as an anti-cancer therapy, however, because of non-specific effects of known HO-1 inhibitors, the discovery of ideal drug lowering HO-1 expression/activity is still an open question. Importantly, in several types of cancer HO-1/CO system exerts opposite activities, making the possible treatment more complicated. All together indicates the complex role for HO-1/CO in various in vitro and in vivo conditions. PMID:26392237

  1. Role of Ca++ in Shoot Gravitropism. [avena

    NASA Technical Reports Server (NTRS)

    Rayle, D. L.

    1985-01-01

    A cornerstone in the argument that Ca(2+) levels may regulate growth is the finding the EGTA promotes straight growth. The usual explanation for these results is that Ca(2+) chelation from cell walls results in wall loosening and thus accelerated straight growth. The ability of frozen-thawed Avena coleoptile tissue (subjected to 15g tension) to extend in response to EGTA and Quin II was examined. The EGTA when applied in weakly buffered (i.e., 0.1mM) neutral solutions initiates rapid extension. When the buffer strength is increased, similar concentrations of EGTA produce no growth response. This implies when EGTA liberated protons are released upon Ca(2+) chelation they can either initiate acid growth (low buffer conditions) or if consumed (high buffer conditions) have no effect. Thus Ca(2+) chelation in itself apparently does not result in straight growth.

  2. Vacuolar Ca(2+) uptake.

    PubMed

    Pittman, Jon K

    2011-08-01

    Calcium transporters that mediate the removal of Ca(2+) from the cytosol and into internal stores provide a critical role in regulating Ca(2+) signals following stimulus induction and in preventing calcium toxicity. The vacuole is a major calcium store in many organisms, particularly plants and fungi. Two main pathways facilitate the accumulation of Ca(2+) into vacuoles, Ca(2+)-ATPases and Ca(2+)/H(+) exchangers. Here I review the biochemical and regulatory features of these transporters that have been characterised in yeast and plants. These Ca(2+) transport mechanisms are compared with those being identified from other vacuolated organisms including algae and protozoa. Studies suggest that Ca(2+) uptake into vacuoles and other related acidic Ca(2+) stores occurs by conserved mechanisms which developed early in evolution. PMID:21310481

  3. Substantial depletion of the intracellular Ca2+ stores is required for macroscopic activation of the Ca2+ release-activated Ca2+ current in rat basophilic leukaemia cells.

    PubMed

    Fierro, L; Parekh, A B

    2000-01-15

    1. Tight-seal whole-cell patch clamp experiments were performed to examine the ability of different intracellular Ca2+ mobilising agents to activate the Ca2+ release-activated Ca2+ current (ICRAC) in rat basophilic leukaemia (RBL-1) cells under conditions of weak cytoplasmic Ca2+ buffering. 2. Dialysis with a maximal concentration of inositol 1,4,5-trisphosphate (IP3) routinely failed to activate macroscopic ICRAC in low buffer (0.mM EGTA, BAPTA or dimethyl BAPTA), whereas it activated the current to its maximal extent in high buffer (10 mM EGTA). Dialysis with a poorly metabolisable analogue of IP3, with ionomycin, or with IP3 and ionomycin all failed to generate macroscopic ICRAC in low Ca2+ buffering conditions. 3. Dialysis with the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pump blocker thapsigargin was able to activate ICRAC even in the presence of low cytoplasmic Ca2+ buffering, albeit at a slow rate. Exposure to IP3 together with the SERCA blockers thapsigargin, thapsigargicin or cyclopiazonic acid rapidly activated ICRAC in low buffer. 4. Following activation of ICRAC by intracellular dialysis with IP3 and thapsigargin in low buffer, the current was very selective for Ca2+ (apparent KD of 1 mM) Sr2+ and Ba2+ were less effective charge carriers and Na+ was not conducted to any appreciable extent. The ionic selectivity of ICRAC was very similar in low or high intracellular Ca2+ buffer. 5. Fast Ca2+-dependent inactivation of ICRAC occurred at a similar rate and to a similar extent in low or high Ca2+ buffer. Ca2+-dependent inactivation is not the reason why macroscopic ICRAC cannot be seen under conditions of low cytoplasmic Ca2+ buffering. 6. ICRAC could be activated by combining IP3 with thapsigargin, even in the presence of 100 microM Ca2+ and the absence of any exogenous Ca2+ chelator, where ATP and glutamate represented the only Ca2+ buffers in the pipette solution. 7. Our results suggest that a threshold exists within the IP3-sensitive Ca2+ store

  4. 40 CFR Table Mm-1 to Subpart Mm of... - Default Factors for Petroleum Products and Natural Gas Liquids 1 2

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and Natural Gas Liquids 1 2 MM Table MM-1 to Subpart MM of Part 98 Protection of Environment... Factors for Petroleum Products and Natural Gas Liquids 1 2 Products Column A: density(metric tons/bbl... Natural Gas Liquids Aviation Gasoline 0.1120 85.00 0.3490 Special Naphthas 0.1222 84.76 0.3798...

  5. 40 CFR Table Mm-1 to Subpart Mm of... - Default Factors for Petroleum Products and Natural Gas Liquids 1 2

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and Natural Gas Liquids 1 2 MM Table MM-1 to Subpart MM of Part 98 Protection of Environment... Factors for Petroleum Products and Natural Gas Liquids 1 2 Products Column A: density(metric tons/bbl... Natural Gas Liquids Aviation Gasoline 0.1120 85.00 0.3490 Special Naphthas 0.1222 84.76 0.3798...

  6. 40 CFR Table Mm-1 to Subpart Mm of... - Default Factors for Petroleum Products and Natural Gas Liquids 1 2

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and Natural Gas Liquids 1 2 MM Table MM-1 to Subpart MM of Part 98 Protection of Environment... Factors for Petroleum Products and Natural Gas Liquids 1 2 Products Column A: density(metric tons/bbl... Natural Gas Liquids Aviation Gasoline 0.1120 85.00 0.3490 Special Naphthas 0.1222 84.76 0.3798...

  7. 40 CFR Table Mm-1 to Subpart Mm of... - Default Factors for Petroleum Products and Natural Gas Liquids 1 2

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and Natural Gas Liquids 1 2 MM Table MM-1 to Subpart MM of Part 98 Protection of Environment... Factors for Petroleum Products and Natural Gas Liquids 1 2 Products Column A: density(metric tons/bbl... Natural Gas Liquids Aviation Gasoline 0.1120 85.00 0.3490 Special Naphthas 0.1222 84.76 0.3798...

  8. 40 CFR Table Mm-2 to Subpart Mm of... - Default Factors for Biomass-Based Fuels and Biomass

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Default Factors for Biomass-Based Fuels and Biomass MM Table MM-2 to Subpart MM of Part 98 Protection of Environment ENVIRONMENTAL... Biomass-Based Fuels and Biomass Biomass-based fuel and biomass Column A:Density (metric tons/bbl) Column...

  9. 40 CFR Table Mm-2 to Subpart Mm of... - Default Factors for Biomass-Based Fuels and Biomass

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Default Factors for Biomass-Based Fuels and Biomass MM Table MM-2 to Subpart MM of Part 98 Protection of Environment ENVIRONMENTAL... Biomass-Based Fuels and Biomass Biomass-based fuel and biomass Column A:Density (metric tons/bbl) Column...

  10. 40 CFR Table Mm-2 to Subpart Mm of... - Default Factors for Biomass-Based Fuels and Biomass

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Default Factors for Biomass-Based Fuels and Biomass MM Table MM-2 to Subpart MM of Part 98 Protection of Environment ENVIRONMENTAL... Biomass-Based Fuels and Biomass Biomass-based fuel and biomass Column A:Density (metric tons/bbl) Column...

  11. A λ = 1.3 mm and 2 mm molecular line survey towards M 82

    NASA Astrophysics Data System (ADS)

    Aladro, R.; Martín, S.; Martín-Pintado, J.; Mauersberger, R.; Henkel, C.; Ocaña Flaquer, B.; Amo-Baladrón, M. A.

    2011-11-01

    Aims: We study the chemical complexity towards the central parts of the starburst galaxy M 82, and investigate the role of certain molecules as tracers of the physical processes in the galaxy circumnuclear region. Methods: We carried out a spectral line survey with the IRAM-30 m telescope towards the northeastern molecular lobe of M 82. It covers the frequency range between 129.8 GHz and 175.0 GHz in the 2 mm atmospheric window, and between 241.0 GHz and 260.0 GHz in the 1.3 mm atmospheric window. Results: Sixty-nine spectral features corresponding to 18 different molecular species are identified. In addition, three hydrogen recombination lines are detected. The species NO, H2S, H2CS, NH2CN, and CH3CN are detected for the first time in this galaxy. Assuming local thermodynamic equilibrium, we determine the column densities of all the detected molecules. We also calculate upper limits to the column densities of fourteen other important, but undetected, molecules, such as SiO, HNCO, or OCS. We compare the chemical composition of the two starburst galaxies M 82 and NGC 253. This comparison enables us to establish the chemical differences between the products of the strong photon-dominated regions driving the heating in M 82, and the large-scale shocks that influence the properties of the molecular clouds in the nucleus of NGC 253. Conclusions: Overall, both sources have different chemical compositions. Some key molecules highlight the different physical processes dominating both central regions. Examples include CH3CCH, c-C3H2, or CO+, the abundances of which are clearly higher in M 82 than in NGC 253, pointing at photodissociating regions. On the other hand, species such as CH2NH, NS, SiO, and HOCO+ have abundances of up to one order of magnitude higher in NGC 253 than in M 82. Appendix is available in electronic form at http://www.aanda.org

  12. Role of sarcomere mechanics and Ca2+ overload in Ca2+ waves and arrhythmias in rat cardiac muscle.

    PubMed

    ter Keurs, Henk E D J; Wakayama, Yuji; Sugai, Yoshinao; Price, Guy; Kagaya, Yutaka; Boyden, Penelope A; Miura, Masahito; Stuyvers, Bruno D M

    2006-10-01

    Ca(2+) release from the sarcoplasmic reticulum (SR) depends on the sarcoplasmic reticulum (SR) Ca(2+) load and the cytosolic Ca(2+) level. Arrhythmogenic Ca(2+) waves underlying triggered propagated contractions arise from Ca(2+) overloaded regions near damaged areas in the cardiac muscle. Ca(2+) waves can also be induced in undamaged muscle, in regions with nonuniform excitation-contraction (EC) coupling by the cycle of stretch and release in the border zone between the damaged and intact regions. We hypothesize that rapid shortening of sarcomeres in the border zone during relaxation causes Ca(2+) release from troponin C (TnC) on thin filaments and initiates Ca(2+) waves. Elimination of this shortening will inhibit the initiation of Ca(2+) waves, while SR Ca(2+) overload will enhance the waves. Force, sarcomere length (SL), and [Ca(2+)](i) were measured and muscle length was controlled. A small jet of Hepes solution with an extracellular [Ca(2+)] 10 mM (HC), or HC containing BDM, was used to weaken a 300 mum long muscle segment. Trains of electrical stimuli were used to induce Ca(2+) waves. The effects of small exponential stretches on triggered propagatory contraction (TPC) amplitude and propagation velocity of Ca(2+) waves (V(prop)) were studied. Sarcomere shortening was uniform prior to activation. HC induced spontaneous diastolic sarcomere contractions in the jet region and attenuated twitch sarcomere shortening; HC+ butanedione monoxime (BDM) caused stretch only in the jet region. Stimulus trains induced Ca(2+) waves, which started inside the HC jet region during twitch relaxation. Ca(2+) waves started in the border zone of the BDM jet. The initial local [Ca(2+)](i) rise of the waves by HC was twice that by BDM. The waves propagated at a V(prop) of 2.0 +/- 0.2 mm/sec. Arrhythmias occurred frequently in trabeculae following exposure to the HC jet. Stretch early during relaxation, which reduced sarcomere shortening in the weakened regions, substantially

  13. Dual Effect of Phosphate Transport on Mitochondrial Ca2+ Dynamics*

    PubMed Central

    Wei, An-Chi; Liu, Ting; O'Rourke, Brian

    2015-01-01

    The large inner membrane electrochemical driving force and restricted volume of the matrix confer unique constraints on mitochondrial ion transport. Cation uptake along with anion and water movement induces swelling if not compensated by other processes. For mitochondrial Ca2+ uptake, these include activation of countertransporters (Na+/Ca2+ exchanger and Na+/H+ exchanger) coupled to the proton gradient, ultimately maintained by the proton pumps of the respiratory chain, and Ca2+ binding to matrix buffers. Inorganic phosphate (Pi) is known to affect both the Ca2+ uptake rate and the buffering reaction, but the role of anion transport in determining mitochondrial Ca2+ dynamics is poorly understood. Here we simultaneously monitor extra- and intra-mitochondrial Ca2+ and mitochondrial membrane potential (ΔΨm) to examine the effects of anion transport on mitochondrial Ca2+ flux and buffering in Pi-depleted guinea pig cardiac mitochondria. Mitochondrial Ca2+ uptake proceeded slowly in the absence of Pi but matrix free Ca2+ ([Ca2+]mito) still rose to ∼50 μm. Pi (0.001–1 mm) accelerated Ca2+ uptake but decreased [Ca2+]mito by almost 50% while restoring ΔΨm. Pi-dependent effects on Ca2+ were blocked by inhibiting the phosphate carrier. Mitochondrial Ca2+ uptake rate was also increased by vanadate (Vi), acetate, ATP, or a non-hydrolyzable ATP analog (AMP-PNP), with differential effects on matrix Ca2+ buffering and ΔΨm recovery. Interestingly, ATP or AMP-PNP prevented the effects of Pi on Ca2+ uptake. The results show that anion transport imposes an upper limit on mitochondrial Ca2+ uptake and modifies the [Ca2+]mito response in a complex manner. PMID:25963147

  14. Ramipril protects the endothelium from high glucose-induced dysfunction through CaMKKβ/AMPK and heme oxygenase-1 activation.

    PubMed

    Tian, Shiliu; Ge, Xinfa; Wu, Ke; Yang, Huabing; Liu, Yu

    2014-07-01

    This study aims to investigate the effects of ramipril (RPL) on endothelial dysfunction associated with diabetes mellitus using cultured human aortic endothelial cells (HAECs) and a type 2 diabetic animal model. The effect of RPL on vasodilatory function in fat-fed, streptozotocin-treated rats was assessed. RPL treatment of 8 weeks alleviated insulin resistance and inhibited the decrease in endothelium-dependent vasodilation in diabetic rats. RPL treatment also reduced serum advanced glycation end products (AGE) concentration and rat aorta reactive oxygen species formation and increased aorta endothelium heme oxygenase-1 (HO-1) expression. Exposure of HAECs to high concentrations of glucose induced prolonged oxidative stress, apoptosis, and accumulation of AGEs. These effects were abolished by incubation of ramiprilat (RPT), the active metabolite of RPL. However, treatment of HAECs with STO-609, a CaMKKβ (Ca(2+)/calmodulin-dependent protein kinase kinase-β) inhibitor; compound C, an AMPK (AMP-activated protein kinase) inhibitor; and Zn(II)PPIX, a selective HO-1 inhibitor, blocked these beneficial effects of RPT. In addition, RPT increased nuclear factor erythroid 2-related factor-2 (Nrf-2) nuclear translocation and activation in a CaMKKβ/AMPK pathway-dependent manner, leading to increased expression of the Nrf-2-regulated antioxidant enzyme, HO-1. The inhibition of CaMKKβ or AMPK by pharmaceutical approach ablated RPT-induced HO-1 expression. Taken together, RPL ameliorates insulin resistance and endothelial dysfunction in diabetes via reducing oxidative stress. These effects are mediated by RPL activation of CaMKK-β, which in turn activates the AMPK-Nrf-2-HO-1 pathway for enhanced endothelial function. PMID:24741076

  15. T-type Ca2+ channels mediate propagation of odor-induced Ca2+ transients in rat olfactory receptor neurons.

    PubMed

    Gautam, S H; Otsuguro, K-I; Ito, S; Saito, T; Habara, Y

    2007-01-19

    Propagation of odor-induced Ca(2+) transients from the cilia/knob to the soma in mammalian olfactory receptor neurons (ORNs) is thought to be mediated exclusively by high-voltage-activated Ca(2+) channels. However, using confocal Ca(2+) imaging and immunocytochemistry we identified functional T-type Ca(2+) channels in rat ORNs. Here we show that T-type Ca(2+) channels in ORNs also mediate propagation of odor-induced Ca(2+) transients from the knob to the soma. In the presence of the selective inhibitor of T-type Ca(2+) channels mibefradil (10-15 microM) or Ni(2+) (100 microM), odor- and forskolin/3-isobutyl-1-methyl-xanthine (IBMX)-induced Ca(2+) transients in the soma and dendrite were either strongly inhibited or abolished. The percentage of inhibition of the Ca(2+) transients in the knob, however, was 40-50% less than that in the soma. Ca(2+) transients induced by 30 mM K(+) were partially inhibited by mibefradil, but without a significant difference in the extent of inhibition between the knob and soma. Furthermore, an increase of as little as 2.5 mM in the extracellular K(+) concentration (7.5 mM K(+)) was found to induce Ca(2+) transients in ORNs, and such responses were completely inhibited by mibefradil or Ni(2+). Total replacement of extracellular Na(+) with N-methyl-d-glutamate inhibited none of the odor-, forskolin/IBMX- or 7.5 mM K(+)-induced Ca(2+) transients. Positive immunoreactivity to the Ca(v)3.1, Ca(v)3.2 and Ca(v)3.3 subunits of the T-type Ca(2+) channel was observed throughout the soma, dendrite and knob. These data suggest that involvement of T-type Ca(2+) channels in the propagation of odor-induced Ca(2+) transients in ORNs may contribute to signal transduction and odor sensitivity. PMID:17110049

  16. Effects of cytosolic ATP on spontaneous and triggered Ca2+-induced Ca2+ release in permeabilised rat ventricular myocytes.

    PubMed

    Yang, Z; Steele, D S

    2000-02-15

    1. The effects of cytosolic ATP on sarcoplasmic reticulum (SR) Ca2+ regulation were investigated in saponin-permeabilised rat ventricular myocytes. [Ca2+] within the cells was monitored using Fura-2 or Fluo-3 fluorescence. Spontaneous cyclic Ca2+ release from the SR was induced by increasing the bathing [Ca2+] to 200-300 nM, in solutions weakly Ca2+ buffered with 0.05 mM EGTA. Alternatively, Ca2+-induced Ca2+ release (CICR) was triggered by a rapid increase in [Ca2+] induced by flash photolysis of Nitr-5 (0.08 mM), replacing EGTA in the solution. 2. Stepwise reductions in [ATP] were associated with corresponding decreases in the frequency and increases in the amplitude of spontaneous Ca2+ transients. A decrease from 5 mM to 0. 1 mM ATP, reduced the release frequency by 48.6 +/- 7 % (n = 7) and almost doubled the amplitude of the Ca2+ transient. Marked prolongation of the spontaneous Ca2+ transient occurred when [ATP] was further reduced to 10 microM, consistent with inhibition of the SR Ca2+ pump. 3. These effects of ATP were compared with other interventions that inhibit Ca2+ uptake or reduce the sensitivity of the SR Ca2+ release mechanism. Inhibition of the SR Ca2+ pump with cyclopiazonic acid (CPA) markedly reduced the spontaneous Ca2+ release frequency, without changing the amplitude. The descending phase of the Ca2+ transient was prolonged in the presence of CPA, while the rising phase was unaffected. In contrast, desensitisation of the SR Ca2+ release mechanism with tetracaine decreased the frequency of spontaneous release, but markedly increased the amplitude. 4. CICR triggered by flash photolysis of Nitr-5 appeared to be more sensitive to cytosolic [ATP] than spontaneous release and was generally delayed by a decrease to 2.5 mM ATP. In the presence of 0.1-0.2 mM ATP, release often failed completely or was not consistently triggered. Some preparations exhibited Ca2+ release 'alternans', whereby every alternate trigger induced a response. 5. These results

  17. Osmotically induced cytosolic free Ca(2+) changes in human neutrophils.

    PubMed

    Morris, M R; Doull, I J; Hallett, M B

    2001-02-01

    Cytosolic free Ca(2+) concentration in neutrophils was measured by ratiometric fluorometry of intracellular fura2. Increasing the extracellular osmolarity, by either NaCl (300-600 mM) or sucrose (600-1200 mM), caused a rise in cytosolic free Ca(2+) (Delta(max) approximately equal to 600 nM). This was not due to cell lysis as the cytosolic free Ca(2+) concentration was reversed by restoration of isotonicity and a second rise in cytosolic free Ca(2+) could be provoked by repeating the change in extracellular osmolarity. Furthermore, the rise in cytosolic free Ca(2+) concentration occurred in the absence of extracellular Ca(2+), demonstrating that release of intracellular fura2 into the external medium did not occur. The osmotically-induced rise in cytosolic free Ca(2+) was not inhibited by either the phospholipase C-inhibitor U73122, or the microfilament inhibitor cytochalasin B, suggesting that neither signalling via inositol tris-phosphate or the cytoskeletal system were involved. However, the rise in cytosolic free Ca(2+) may have resulted from a reduction in neutrophil water volume in hyperosmotic conditions. As these rises in cytosolic Ca(2+) (Delta(max) approximately equal to 600 nM) were large enough to provoke changes in neutrophil activity, we propose that conditions which removes cell water may similarly elevate cytosolic free Ca(2+) to physiologically important levels. PMID:11341979

  18. A λ 3 mm and 1 mm line survey toward the yellow hypergiant IRC +10420⋆

    PubMed Central

    Quintana-Lacaci, G.; Agúndez, M.; Cernicharo, J.; Bujarrabal, V.; Sánchez Contreras, C.; Castro-Carrizo, A.; Alcolea, J.

    2016-01-01

    Aims Our knowledge of the chemical properties of the circumstellar ejecta of the most massive evolved stars is particularly poor. We aim to study the chemical characteristics of the prototypical yellow hypergiant star, IRC +10420. For this purpose, we obtained full line surveys at 1 and 3 mm atmospheric windows. Methods We have identified 106 molecular emission lines from 22 molecular species. Approximately half of the molecules detected are N-bearing species, in particular HCN, HNC, CN, NO, NS, PN, and N2H+. We used rotational diagrams to derive the density and rotational temperature of the different molecular species detected. We introduced an iterative method that allows us to take moderate line opacities into account. Results We have found that IRC +10420 presents high abundances of the N-bearing molecules compared with O-rich evolved stars. This result supports the presence of a N-rich chemistry, expected for massive stars. Our analysis also suggests a decrease of the 12C/13C ratio from ≳ 7 to ~ 3.7 in the last 3800 years, which can be directly related to the nitrogen enrichment observed. In addition, we found that SiO emission presents a significant intensity decrease for high-J lines when compared with older observations. Radiative transfer modeling shows that this variation can be explained by a decrease in the infrared (IR) flux of the dust. The origin of this decrease might be an expansion of the dust shell or a lower stellar temperature due to the pulsation of the star. PMID:27458319

  19. Efficacy and safety of Ho:YAG Laser Lithotripsy for ureteroscopic removal of proximal and distal ureteral calculi

    PubMed Central

    2014-01-01

    Background Laser lithotripsy is an established endourological modality. Ho:YAG laser have broadened the indications for ureteroscopic stone managements to include larger stone sizes throughout the whole upper urinary tract. Aim of current work is to assess efficacy and safety of Ho:YAG laser lithotripsy during retrograde ureteroscopic management of ureteral calculi in different locations. Methods 88 patients were treated with ureteroscopic Ho:YAG laser lithotripsy in our institute. Study endpoint was the number of treatments until the patient was stone-free. Patients were classified according to the location of their stones as Group I (distal ureteric stones, 51 patients) and group II (proximal ureteral stones, 37). Group I patients have larger stones as Group II (10.70 mm vs. 8.24 mm, respectively, P = 0.020). Results Overall stone free rate for both groups was 95.8%. The mean number of procedures for proximal calculi was 1.1 ± 0.1 (1–3) and for distal calculi was 1.0 ± 0.0. The initial treatment was more successful in patients with distal ureteral calculi (100% vs. 82.40%, respectively, P = 0.008). No significant difference in the stone free rate was noticed after the second laser procedure for stones smaller versus larger than 10 mm (100% versus 94.1%, P = 0.13). Overall complication rate was 7.9% (Clavien II und IIIb). Overall and grade-adjusted complication rates were not dependant on the stone location. No laser induced complications were noticed. Conclusions The use of the Ho:YAG laser appears to be an adequate tool to disintegrate ureteral calculi independent of primary location. Combination of the semirigid and flexible ureteroscopes as well as the appropriate endourologic tools could likely improve the stone clearance rates for proximal calculi regardless of stone-size. PMID:25107528

  20. High Energy Directly Pumped Ho:YLF Laser

    NASA Technical Reports Server (NTRS)

    Petros, Mulugeta; Yu, Ji-Rong; Singh, Upendra N.; Barnes, Norman P.

    2000-01-01

    The most commonly used crystal architecture to produce 2 micrometer laser is co-doping Ho and Tm into a single host crystal. In this method, the stored energy transfer from the Tm (3)F4 to the Ho (5)I7 manifold is not fast enough to warrant high efficiency for short pulse applications. By separating the Ho and the Tm ions and doping the Tm in YALO3 and the Ho in YLF, we were able to directly pump the Ho (5)I7 manifold with 1.94 micrometers. The Ho:YLF laser has produced 33 mJ at 2.062 micrometers with a quantum efficiency of 0.88. The performance of each laser will be presented.

  1. Ca channel gating during cardiac action potentials.

    PubMed

    Mazzanti, M; DeFelice, L J

    1990-10-01

    How do Ca channels conduct Ca ions during the cardiac action potential? We attempt to answer this question by applying a two-microelectrode technique, previously used for Na and K currents, in which we record the patch current and the action potential at the same time (Mazzanti, M., and L. J. DeFelice. 1987. Biophys. J. 12:95-100, and 1988. Biophys. J. 54:1139-1148; Wellis, D., L. J. DeFelice, and M. Mazzanti. 1990. Biophys. J. 57:41-48). In this paper, we also compare the action currents obtained by the technique with the step-protocol currents obtained during standard voltage-clamp experiments. Individual Ca channels were measured in 10 mM Ca/1 Ba and 10 mM Ba. To describe part of our results, we use the nomenclature introduced by Hess, P., J. B. Lansman, and R. W. Tsien (1984. Nature (Lond.). 311:538-544). With Ba as the charge carrier, Ca channel kinetics convert rapidly from long to short open times as the patch voltage changes from 20 to -20 mV. This voltage-dependent conversion occurs during action potentials and in step-protocol experiments. With Ca as the charge carrier, the currents are brief at all voltages, and it is difficult to define either the number of channels in the patch or the conductance of the individual channels. Occasionally, however, Ca-conducting channels spontaneously convert to long-open-time kinetics (in Hess et al., 1984, notation, mode 2). When this happens, which is about once in every 100beats, there usually appears to be only one channel in the patch. In this rare configuration, the channel is open long enough to measure its conductance in 10 Ca/ 1 Ba. The value is 8-10 pS, which is about half the conductance in Ba. Because the long openings occur so infrequently with Ca as the charge carrier, they contribute negligibly to the average Ca current at any particular time during an action potential. However, the total number of Ca ions entering during these long openings may be significant when compared to the number entering by the

  2. Activation of the Nrf2/HO-1 Antioxidant Pathway Contributes to the Protective Effects of Lycium Barbarum Polysaccharides in the Rodent Retina after Ischemia-Reperfusion-Induced Damage

    PubMed Central

    Chang, Raymond Chuen-Chung; So, Kwok-Fai; Brecha, Nicholas C.; Pu, Mingliang

    2014-01-01

    Lycium barbarum polysaccharides (LBP), extracts from the wolfberries, are protective to retina after ischemia-reperfusion (I/R). The antioxidant response element (ARE)–mediated antioxidant pathway plays an important role in maintaining the redox status of the retina. Heme oxygenase-1 (HO-1), combined with potent AREs in its promoter, is a highly effective therapeutic target for the protection against neurodegenerative diseases, including I/R-induced retinal damage. The aim of our present study was to investigate whether the protective effect of LBP after I/R damage was mediated via activation of the Nrf2/HO-1-antioxidant pathway in the retina. Retinal I/R was induced by an increase in intraocular pressure to 130 mm Hg for 60 minutes. Prior to the induction of ischemia, rats were orally treated with either vehicle (PBS) or LBP (1 mg/kg) once a day for 1 week. For specific experiments, zinc protoporphyrin (ZnPP, 20 mg/kg), an HO-1 inhibitor, was intraperitoneally administered at 24 h prior to ischemia. The protective effects of LBP were evaluated by quantifying ganglion cell and amacrine cell survival, and by measuring cell apoptosis in the retinal layers. In addition, HO-1 expression was examined using Western blotting and immunofluorescence analyses. Cytosolic and nuclear Nrf2 was measured using immunofluorescent staining. LBP treatment significantly increased Nrf2 nuclear accumulation and HO-1 expression in the retina after I/R injury. Increased apoptosis and a decrease in the number of viable cells were observed in the ganglion cell layer (GCL) and inner nuclear layer (INL) in the I/R retina, which were reversed by LBP treatment. The HO-1 inhibitor, ZnPP, diminished the LBP treatment-induced protective effects in the retina after I/R. Taken together, these results suggested that LBP partially exerted its beneficial neuroprotective effects via the activation of Nrf2 and an increase in HO-1 protein expression. PMID:24400114

  3. Rotational bands in neutron-rich 160-162Ho

    SciTech Connect

    Escrig, D.; Jungclaus, A.; Binder, B.; Dietrich, A.; Haertlein, T.; Bauer, H.; Gund, Ch.; Pansegrau, D.; Schwalm, D.; Bazzacco, D.; De Angelis, G.; Farnea, E.; Gadea, A.; Lunardi, S.; Napoli, D.R.; Rossi-Alvarez, C.; Ur, C.

    2004-02-27

    We have studied the high spin states in 160-162Ho in order to investigate the properties of the rotational bands and their dependence on the single particle orbits involved. The reaction 158,160Gd(7Li,xn) at 56 MeV were used to produce the Ho isotopes of interest. In all three Ho isotopes the known rotational bands have been significantly extended. New band-crossings have been observed for the first time in this work.

  4. Spectroscopic and lasing properties of Ho:Tm:LuAG

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P.; Filer, Elizabeth D.; Naranjo, Felipe L.; Rodriguez, Waldo J.; Kokta, Milan R.

    1993-01-01

    Ho:Tm:LuAG has been grown, examined spectroscopically, and lased at 2.1 microns. Ho:Tm:LuAG was selected for this experimental investigation when quantum-mechanical modeling predicted that it would be a good laser material for Ho laser operation on one of the 5I7 to 5I8 transitions. Lasing was achieved at 2.100 microns, one of the three wavelengths predicted to be most probable for laser action.

  5. 2. West portal of Tunnel 39, view to east, 135mm ...

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

    2. West portal of Tunnel 39, view to east, 135mm lens with electronic flash fill. Note the notched wingwalls that support steel posts of entrance snowshed; these would have originally held timber posts of the original timber snowsheds, miles of which once enclosed and protected the railroad from the ravages of Sierra winters. Note also that these tunnels, built in the 1920s, have dispensed with any use of stone masonry, and instead have all-concrete portals. - Central Pacific Transcontinental Railroad, Tunnel No. 39, Milepost 180.95, Cisco, Placer County, CA

  6. 2. West portal of Tunnel 35, view to east, 135mm ...

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

    2. West portal of Tunnel 35, view to east, 135mm lens with electronic flash fill. Note the notched wingwalls that support steel posts of entrance snowshed; these would have originally held timber posts of the original timber snowsheds, miles of which once enclosed and protected the railroad from the ravages of Sierra winters. Note also that these tunnels, built in the 1920s, have dispensed with any use of stone masonry, and instead have all-concrete portals. - Central Pacific Transcontinental Railroad, Tunnel No. 35, Milepost 176.62, Yuba Pass, Nevada County, CA

  7. 3. West portal of Tunnel 23, view to north, 135mm ...

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

    3. West portal of Tunnel 23, view to north, 135mm lens. Concrete foundation in right foreground was from 'telltale,' a simple post-and-beam frame that spanned the tracks with lengths of rope suspended from the beam. In the days when brakemen were required to be on, and walk along, the tops of freight cars to set brakes, the 'telltale' ropes would strike the unwary to warn of the tunnel ahead, allowing them to lie flat and avoid being struck by the tunnel portal. - Central Pacific Transcontinental Railroad, Tunnel No. 23, Milepost 132.69, Applegate, Placer County, CA

  8. 2. West portal of Tunnel 37 view to eastsoutheast, 135mm ...

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

    2. West portal of Tunnel 37 view to east-southeast, 135mm lens. Note the notched wingwalls that would have originally held timber posts of the original timber snowsheds, miles of which once enclosed and protected the railroad from the ravages of Sierra winters. Note also that these tunnels, built in the 1920s, have dispensed with any use of stone masonry, and instead have all-concrete portals, though this tunnel retains the use of rubble granite slab slope protection flanking the portal. - Central Pacific Transcontinental Railroad, Tunnel No. 37, Milepost 177.79, Yuba Pass, Nevada County, CA

  9. 2. West portal of Tunnel 38, view to east, 135mm ...

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

    2. West portal of Tunnel 38, view to east, 135mm lens. Note the notched wingwalls that support steel posts of entrance snowshed; these would have originally held timber posts of the original timber snowsheds, miles of which once enclosed and protected the railroad from the ravages of Sierra winters. Note also that these tunnels, built in the 1920s, have dispensed with any use of stone masonry, and instead have all-concrete portals. - Central Pacific Transcontinental Railroad, Tunnel No. 38, Milepost 180.58, Cisco, Placer County, CA

  10. Reentrant superconductivity in HoNi5-NbN-HoNi5 nanostructures

    NASA Astrophysics Data System (ADS)

    Singh, Gyanendra; Joshi, P. C.; Hossain, Z.; Budhani, R. C.

    2013-08-01

    Superconductivity (S) and ferromagnetism (F) are probed through transport and magnetization measurements in nanometer scale HoNi5-NbN (F-S) bilayers and HoNi5-NbN-HoNi5 (F-S-F) trilayers. The choice of materials has been made on the basis of their comparable ordering temperatures and strong magnetic anisotropy in HoNi5. We observe the normal state reentrant behavior in resistance vs. temperature plots of the F-S-F structures just below the superconducting transition in the limited range of HoNi5 layer thickness dHN (20\\ \\text{nm}) when d_{\\textit{NbN}} is fixed at{}\\simeq 10\\ \\text{nm} . The reentrance is quenched by increasing the out-of-plane (H_{\\perp} ) magnetic field and transport current where as in-plane (H_{\\parallel} ) field of \\leq 1500\\ \\text{Oe} has no effect on the reentrance. The origin of the reentrant behavior seen here in the range T_{\\textit{Curie}}/T_C \\leq 0.92 is attributed to a delicate balance between the magnetic exchange energy and the condensation energy in the interfacial regions of the trilayer.

  11. Is smaller better? Comparison of 3-mm and 5-mm leaf size for stereotactic radiosurgery: A dosimetric study

    SciTech Connect

    Chern, Shyh-shi . E-mail: Richard.Chern@hci.utah.edu; Leavitt, Dennis D.; Jensen, Randy L.; Shrieve, Dennis C.

    2006-11-15

    Purpose: To perform a dosimetric comparison of a minimal 3-mm leaf width multileaf collimator (MLC) and a minimal 5-mm MLC in dynamic conformal arc stereotactic radiosurgery for treatment of intracranial lesions. Methods and Materials: The treatment plans of 23 patients previously treated for intracranial lesions in our institution were redone using the BrainSCAN, version 5.3, stereotactic radiosurgery treatment planning system (BrainLAB). For each case, two dynamic conformal arc plans were generated: one using a minimal 3-mm micro-MLC (BrainLAB, Novalis) and one using a minimal 5-mm MLC (Varian Millennium). All arc parameters were the same in each of the two plans, except for the collimator angle settings. The collimator angle settings were optimized for each arc in each plan. A peritumoral rind structure (1 cm) was created to evaluate normal tissue sparing immediately adjacent to the target volume. Conformity indexes (CIs) were calculated for each plan. The dependence of normal tissue sparing and target conformity on target volume (TV) was determined. Results: The TV was 0.14-36.32 cm{sup 3} (median, 5.90). The CI was 1.22-2.60 (median, 1.51) for the 3-mm micro-MLC and 1.23-2.69 (median, 1.60) for the 5-mm MLC. Despite this small difference, it was a statistically significant increase (p < 0.0001) for the 5-mm MLC compared with the 3-mm micro-MLC. Improved normal tissue sparing was demonstrated using the 3-mm micro-MLC compared with the 5-mm MLC by examining the peritumoral rind volumes (PRVs) receiving 50% (PRV{sub 5}), 80% (PRV{sub 8}), and 90% (PRV{sub 9}) of the prescription dose. The reduction in the PRV{sub 5}, PRV{sub 8}, and PRV{sub 9} for the 3-mm micro-MLC compared with the 5-mm MLC was 13.5%, 12.9%, and 11.5%, respectively. The CI decreased with a larger TV, as did the difference in the CIs between the 3-mm micro-MLC and 5-mm MLC. A reduction in the PRV increased with larger TVs. Conclusion: The 3-mm micro-MLC provided better target conformity and

  12. Index to 8mm Motion Cartridges. Third Edition.

    ERIC Educational Resources Information Center

    University of Southern California, Los Angeles. National Information Center for Educational Media.

    Research at the National Information Center for Educational Media has shown that the 8mm motion cartridge with optical and magnetic sound seems to meet the basic tenets of a prime educational criterion for an educational medium--that it be available to the learner at his convenience. This is a bibliographical source for 8mm motion cartridges, and…

  13. Index to 8mm Motion Cartridges. Fourth Edition.

    ERIC Educational Resources Information Center

    University of Southern California, Los Angeles. National Information Center for Educational Media.

    Research at the National Information Center for Educational Media (NICEM) has shown that the 8mm motion cartridge with optical and magnetic sound seems to meet the basic tenets of a prime educational criterion for an educational medium--that it be available to the learner at his convenience. This is a bibliographical source for 8mm motion…

  14. Do Noncontingent Interviewer Mm-hmms Facilitate Interviewee Productivity?

    ERIC Educational Resources Information Center

    Siegman, Aron Wolfe

    1976-01-01

    Two studies investigated the hypothesis that noncontingent interviewer "mm-hmms" facilitate interviewee verbal productivity. Within- and between-subjects comparisons failed to support the hypothesis, although interviewees' ratings indicate that the mm-hmms were perceived as the social reinforcers they were intended to be. (Author)

  15. Improving Student Understanding of Magmatic Differentiation Using an M&M Magma Chamber

    NASA Astrophysics Data System (ADS)

    Wirth, K. R.

    2003-12-01

    Many students, especially those in introductory geology courses, have difficulty developing a deep understanding of the processes of magmatic differentiation. In particular, students often struggle to understand Bowen's reaction series and fractional crystallization. The process of fractional crystallization by gravity settling can be illustrated using a model magma chamber consisting of M&M's. In this model, each major cation (e.g., Si, Ti, Al, Fe, Mg, Ca, Na, K) is represented by a different color M&M; other kinds of differently colored or shaped pieces could also be used. Appropriate numbers of each color M&M are combined to approximate the cation proportions of a basaltic magma. Students then fractionate the magma by moving M&M's to the bottom of the magma chamber forming a series of cumulus layers; the M&M's are removed in the stoichiometric proportions of cations in the crystallizing minerals (e.g., olivine, pyroxene, feldspars, quartz, magnetite, ilmenite). Students observe the changing cation composition (proportions of colors of M&M's) in the cumulus layers and in the magma chamber and graph the results using spreadsheet software. More advanced students (e.g., petrology course) can classify the cumulates and resulting liquid after each crystallization step, and they can compare the model system with natural magmatic systems (e.g., absence of important fractionating phases, volatiles). Students who have completed this exercise generally indicate a positive experience and demonstrate increased understanding of Bowen's reaction series and fractionation processes. They also exhibit greater familiarity with mineral stoichiometry, classification, solid-solution in minerals, element behavior (e.g., incompatibility), and chemical variation diagrams. Other models (e.g., paths of equilibrium and fractional crystallization on phase diagrams) can also be used to illustrate differentiation processes in upper level courses (e.g., mineralogy and petrology).

  16. Thales Angenieux: 42 years of cine 35 mm zoom leadership

    NASA Astrophysics Data System (ADS)

    Debize, Jacques

    2004-02-01

    Since the early years of zoom optics, Angenieux has been involved in cine 8 mm, 16 mm and 35 mm. Among more than twenty different zoom lenses, four of them have been milestones in this field, technical progresses being sanctified by two Oscars in 1964 and 1990. From 1960 to 2002 Angenieux has created first the 4 x 35 LA2, the first four times mechanically compensated zoom lens for cine 35 mm in the world, secondary the 10 x 25 T2, the first ten times mechanically compensated zoom lens for cine 35 mm in the world, then the 10 x 25 HR, the top level of quality for its category and finally the 12 x 24 Optimo with all characteristics and performances greatly increased. This leadership has been reached thanks to computers and in-house softwares but also thanks to new manufacturing processes.

  17. Hořava-Lifshitz quantum cosmology

    NASA Astrophysics Data System (ADS)

    Bertolami, Orfeu; Zarro, Carlos A. D.

    2011-08-01

    In this work, a minisuperspace model for the projectable Hořava-Lifshitz gravity without the detailed-balance condition is investigated. The Wheeler-DeWitt equation is derived and its solutions are studied and discussed for some particular cases where, due to Hořava-Lifshitz gravity, there is a “potential barrier” nearby a=0. For a vanishing cosmological constant, a normalizable wave function of the Universe is found. When the cosmological constant is nonvanishing, the WKB method is used to obtain solutions for the wave function of the Universe. Using the Hamilton-Jacobi equation, one discusses how the transition from quantum to classical regime occurs and, for the case of a positive cosmological constant, the scale factor is shown to grow exponentially, hence recovering the general relativity behavior for the late Universe.

  18. Ho Doped BixSby Nanopolycrystalline Alloys

    NASA Astrophysics Data System (ADS)

    Lukas, K. C.; Joshi, G.; Wang, Dezhi; Ren, Z. F.; Opeil, C. P.

    2011-03-01

    Department of Physics, Boston College, Chestnut Hill, Massachusetts, 02467. Bismuth-Antimony alloys have been shown to have high ZT values below room temperature, especially for single crystals. For polycrystalline samples, impurity doping and magnetic field have proven to be powerful tools in the search for understanding and improving thermoelectric performance. Nanopolycrystalline BixSby doped with 1 and 3 % Ho were prepared by ball milling and dc hot pressing technique. Electrical resistivity, Seebeck coefficient, thermal conductivity, carrier concentration, mobility, and magnetization are measured in a temperature range of 5-350 K and in magnetic fields up to 9 Tesla. The effects of Ho doping on the thermoelectric properties of BixSby in magnetic field will be discussed. D.O.E. Energy Frontier Research Center Grant (S3TEC), at Massachusetts Institute of Technology.

  19. Low noise, tunable Ho:fiber soliton oscillator for Ho:YLF amplifier seeding

    NASA Astrophysics Data System (ADS)

    Li, Peng; Ruehl, Axel; Bransley, Colleen; Hartl, Ingmar

    2016-06-01

    We present a passively mode-locked, tunable soliton Ho:fiber ring oscillator, optimized for seeding of holmium-doped yttrium lithium flouride (Ho:YLF) amplifiers. The oscillator is independently tunable in central wavelength and spectral width from 2040 to 2070 nm and from 5 to 10 nm, respectively. At all settings the pulse energy within the soliton is around 800 pJ. The soliton oscillator was optimized to fully meet the spectral requirements for seeding Ho:YLF amplifiers. Its Kelly sidebands are located outside the amplifier gain spectrum, resulting in a train of about 1 ps long pedestal-free pulses with relative intensity noise of only 0.13% RMS when integrated from 1 Hz to Nyquist frequency.

  20. Amplitude modulation drive to rectangular-plate linear ultrasonic motors with vibrators dimensions 8 mm x 2.16 mm X 1 mm.

    PubMed

    Ming, Yang; Hanson, Ben; Levesley, Martin C; Walker, Peter G; Watterson, Kevin G

    2006-12-01

    In this paper, to exploit the contribution from not only the stators but also from other parts of miniature ultrasonic motors, an amplitude modulation drive is proposed to drive a miniature linear ultrasonic motor consisting of two rectangular piezoelectric ceramic plates. Using finite-element software, the first longitudinal and second lateral-bending frequencies of the vibrator are shown to be very close when its dimensions are 8 mm x 2.16 mm x 1 mm. So one single frequency power should be able to drive the motor. However, in practice the motor is found to be hard to move with a single frequency power because of its small vibration amplitudes and big frequency difference between its longitudinal and bending resonance, which is induced by the boundary condition variation. To drive the motor effectively, an amplitude modulation drive is used by superimposing two signals with nearly the same frequencies, around the resonant frequency of the vibrators of the linear motor. When the amplitude modulation frequency is close to the resonant frequency of the vibrator's surroundings, experimental results show that the linear motor can move back and forward with a maximum thrust force (over 0.016 N) and a maximum velocity (over 50 mm/s). PMID:17186925

  1. Japanese Science Films; a Descriptive and Evaluative Catalog of: 16mm Motion Pictures, 8mm Cartridges, and Video Tapes.

    ERIC Educational Resources Information Center

    Newren, Edward F., Ed.

    One hundred and eighty Japanese 16mm motion pictures, 8mm cartridges, and video tapes produced and judged appropriate for a variety of audience levels are listed in alphabetical order by title with descriptive and evaluative information. A subject heading list and a subject index to the film titles are included, as well as a sample of the…

  2. Replacing 16 mm film cameras with high definition digital cameras

    SciTech Connect

    Balch, K.S.

    1995-12-31

    For many years 16 mm film cameras have been used in severe environments. These film cameras are used on Hy-G automotive sleds, airborne gun cameras, range tracking and other hazardous environments. The companies and government agencies using these cameras are in need of replacing them with a more cost effective solution. Film-based cameras still produce the best resolving capability, however, film development time, chemical disposal, recurring media cost, and faster digital analysis are factors influencing the desire for a 16 mm film camera replacement. This paper will describe a new camera from Kodak that has been designed to replace 16 mm high speed film cameras.

  3. The 19 mm data recorders similarities and differences

    NASA Technical Reports Server (NTRS)

    Atkinson, Steve

    1992-01-01

    Confusion over the use of non-video 19 mm data recorders is becoming more pronounced as we enter the world of high performance computing. This paper addresses the following: the differences between ID-1, ID-2, MIL-STD-2179 and DD-2; what the proper machine is for various applications; how the machine can be integrated into an environment; and any misconceptions there might be about 19 mm tape recorders. DD-2 and 19 mm instrumentation recorders have missions for which each is well designed. While the differences may appear subtle, understanding the difference between the two is the key to picking the right recorder for a particular application.

  4. Corneal biomechanical properties changes after coaxial 2.2-mm microincision and standard 3.0-mm phacoemulsification

    PubMed Central

    Zhang, Zhe; Yu, Hua; Dong, Hui; Wang, Li; Jia, Ya-Ding; Zhang, Su-Hua

    2016-01-01

    AIM To compare the changes in corneal biomechanics measured by ocular response analyzer (ORA) after 2.2-mm microincision cataract surgery and 3.0-mm standard coaxial phacoemulsification. METHODS The prospective nonrandomized study comprised eyes with cataract that had 2.2-mm coaxial microincision or 3.0-mm standard incision phacoemulsification. The corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc) and Goldmann-correlated intraocular pressure (IOPg) were measured by ORA preoperatively and at 1d, 1-, 2-, 3- and 4-week postoperatively. Results were analyzed and compared between groups. RESULTS In both groups, CH decreased in the immediate postoperative period (P<0.05), returned to the preoperative level at one week (P=0.249) in the 2.2-mm group, and at two weeks in the 3.0-mm group (P=0.264); there was no significant change in CRF values. In 2.2-mm group, mean IOPcc and IOPg increased at 1d postoperatively (both P<0.05), and returned to preoperative level at one week (P=0.491 and P=0.923, respectively). In 3.0-mm group, mean IOPcc and IOPg increased at 1d and 1wk postoperatively (P=0.005 and P=0.029, respectively), and returned to preoperative level at 2wk (P=0.347 and P=0.887, respectively). CONCLUSION Significant differences between preoperative and postoperative corneal biomechanical values were found for CH, IOPcc and IOPg. But the recovery time courses were different between the two groups. The 2.2-mm coaxial microincision cataract surgery group seemed recovery faster compared to the 3.0-mm standard coaxial phacoemulsification group. PMID:26949640

  5. OpenMM: A Hardware Independent Framework for Molecular Simulations

    PubMed Central

    Eastman, Peter; Pande, Vijay S.

    2015-01-01

    The wide diversity of computer architectures today requires a new approach to software development. OpenMM is a framework for molecular mechanics simulations, allowing a single program to run efficiently on a variety of hardware platforms. PMID:26146490

  6. 35 mm PHOTOGRAPH TAKEN PRIOR TO DEMOLITION OF STRUCTURE. SOUTH ...

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

    35 mm PHOTOGRAPH TAKEN PRIOR TO DEMOLITION OF STRUCTURE. SOUTH (SIDE) AND EAST (FRONT) ELEVATIONS OF BUILDING. VIEW TO NORTHWEST - Plattsburgh Air Force Base, Gas Station, New York Road, Plattsburgh, Clinton County, NY

  7. The 19 mm date recorders: Similarities and differences

    NASA Technical Reports Server (NTRS)

    Atkinson, Steve

    1991-01-01

    Confusion over the use of non-video 19 mm data recorders is becoming more pronounced in the world of high performance computing. The following issues are addressed: (1) the difference between ID-1, ID-2, MIL-STD-2179, and DD-2; (2) the proper machine for the necessary application; and (3) integrating the machine into an existing environment. Also, an attempt is made to clear up any misconceptions there might be about 19 mm tape recorders.

  8. Monolithic mm-wave ICs for smart weapons

    NASA Astrophysics Data System (ADS)

    Duffield, T. L.

    1988-04-01

    An approach to developing a low-cost mm-wave transceiver with application to a broad range of smart weapons systems is described. The proposed transceiver technology consists of monolithic mm-wave integrated circuits on GaAs substrates. The relevant transceiver configurations, FET material, and electron beam lithography are discussed. The types of devices to which the approach is applicable are addressed, emphasizing the use of three-terminal devices for all active elements.

  9. QM/MM investigations of organic chemistry oriented questions.

    PubMed

    Schmidt, Thomas C; Paasche, Alexander; Grebner, Christoph; Ansorg, Kay; Becker, Johannes; Lee, Wook; Engels, Bernd

    2014-01-01

    About 35 years after its first suggestion, QM/MM became the standard theoretical approach to investigate enzymatic structures and processes. The success is due to the ability of QM/MM to provide an accurate atomistic picture of enzymes and related processes. This picture can even be turned into a movie if nuclei-dynamics is taken into account to describe enzymatic processes. In the field of organic chemistry, QM/MM methods are used to a much lesser extent although almost all relevant processes happen in condensed matter or are influenced by complicated interactions between substrate and catalyst. There is less importance for theoretical organic chemistry since the influence of nonpolar solvents is rather weak and the effect of polar solvents can often be accurately described by continuum approaches. Catalytic processes (homogeneous and heterogeneous) can often be reduced to truncated model systems, which are so small that pure quantum-mechanical approaches can be employed. However, since QM/MM becomes more and more efficient due to the success in software and hardware developments, it is more and more used in theoretical organic chemistry to study effects which result from the molecular nature of the environment. It is shown by many examples discussed in this review that the influence can be tremendous, even for nonpolar reactions. The importance of environmental effects in theoretical spectroscopy was already known. Due to its benefits, QM/MM can be expected to experience ongoing growth for the next decade.In the present chapter we give an overview of QM/MM developments and their importance in theoretical organic chemistry, and review applications which give impressions of the possibilities and the importance of the relevant effects. Since there is already a bunch of excellent reviews dealing with QM/MM, we will discuss fundamental ingredients and developments of QM/MM very briefly with a focus on very recent progress. For the applications we follow a similar

  10. EGR-1 regulates Ho-1 expression induced by cigarette smoke

    SciTech Connect

    Chen, Huaqun; Wang, Lijuan; Gong, Tao; Yu, Yang; Zhu, Chunhua; Li, Fen; Wang, Li; Li, Chaojun

    2010-05-28

    As an anti-oxidant molecule, heme oxygenase-1 (HO-1) has been implicated in the protection of lung injury by cigarette smoke (CS). The mechanisms regulating its expression have not been defined. In this report, the role of early growth response 1 (EGR-1) in the regulation of Ho-1 expression was investigated. In C57BL/6 mice with CS exposure, HO-1 was greatly increased in bronchial epithelial cells and alveolar inflammatory cells. In primary cultured mouse lung fibroblasts and RAW264.7 cells exposed to cigarette smoke water extract (CSE), an increase in HO-1 protein level was detected. In addition, CSE induced HO-1 expression was decreased in Egr-1 deficient mouse embryo fibroblasts (Egr-1{sup -/-} MEFs). Nuclear localization of EGR-1 was examined in mouse lung fibroblasts after exposure to CSE. Luciferase reporter activity assays showed that the enhancer region of the Ho-1 gene containing a proposed EGR-1 binding site was responsible for the induction of HO-1. A higher increase of alveolar mean linear intercept (Lm) was observed in lung tissues, and a larger increase in the number of total cells and monocytes/macrophages from bronchial alveolar lavage fluid was found in CS-exposed mice by loss of function of EGR-1 treatment. In summary, the present data demonstrate that EGR-1 plays a critical role in HO-1 production induced by CS.

  11. Spectral Line Survey toward the Young Massive Protostar NGC 2264 CMM3 in the 4 mm, 3 mm, and 0.8 mm Bands

    NASA Astrophysics Data System (ADS)

    Watanabe, Yoshimasa; Sakai, Nami; López-Sepulcre, Ana; Furuya, Ryuta; Sakai, Takeshi; Hirota, Tomoya; Liu, Sheng-Yuan; Su, Yu-Nung; Yamamoto, Satoshi

    2015-08-01

    Spectral line survey observations are conducted toward the high-mass protostar candidate NGC 2264 CMM3 in the 4, 3, and 0.8 mm bands with the Nobeyama 45 m telescope and the Atacama Submillimeter Telescope Experiment (ASTE) 10 m telescope. In total, 265 emission lines are detected in the 4 and 3 mm bands, and 74 emission lines in the 0.8 mm band. As a result, 36 molecular species and 30 isotopologues are identified. In addition to the fundamental molecular species, many emission lines of carbon-chain molecules such as HC5N, C4H, CCS, and C3S are detected in the 4 and 3 mm bands. Deuterated molecular species are also detected with relatively strong intensities. On the other hand, emission lines of complex organic molecules such as HCOOCH3 and CH3OCH3 are found to be weak. For the molecules for which multiple transitions are detected, rotation temperatures are derived to be 7-33 K except for CH3OH. Emission lines with high upper-state energies (Eu > 150 K) are detected for CH3OH, indicating the existence of a hot core. In comparison with the chemical composition of the Orion KL, carbon-chain molecules and deuterated molecules are found to be abundant in NGC 2264 CMM3, while sulfur-bearing species and complex organic molecules are deficient. These characteristics indicate the chemical youth of NGC 2264 CMM3 in spite of its location at the center of the cluster forming core, NGC 2264 C.

  12. 2009 Louisiana "HoCP" and "Ho" nursery and infield variety trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three years after selecting in single-stools in the seedling stage, scientists in the breeding program assign “HoCP” or “Ho” numbers to varieties advanced for further testing. These newly assigned varieties are planted in replicated nursery trials at three locations (Ardoyne Farm in Schriever, Iber...

  13. Carbon monoxide stimulates Ca2+ -dependent big-conductance K channels in the cortical collecting duct.

    PubMed

    Wang, Zhijian; Yue, Peng; Lin, Dao-Hong; Wang, Wen-Hui

    2013-03-01

    We used the patch-clamp technique to examine the role of carbon monoxide (CO) in regulating Ca(2+)-activated big-conductance K (BK) channels in the principal cell of the cortical collecting duct (CCD). Application of CORM3 or CORM2, a CO donor, activated BK channels in the CCD, whereas adding inactivated CORM2/3 had no effect. Superfusion of the CCD with CO-bubbled bath solution also activated the BK channels in the cell-attached patches. The effect of CO on BK channels was not dependent on nitric oxide synthase (NOS) because the effect of CORM3 was also observed in the CCD treated with l-NAME, an agent that inhibits the NOS. Adding a membrane-permeable cGMP analog, 8-bromo-cGMP, significantly increased the BK channel in the CCD. However, inhibition of soluble guanylate cyclase failed to abolish the stimulatory effect of CORM3 on BK channels. Moreover, inhibition of cGMP-dependent protein kinase G did not block the stimulatory effect of CORM3 on the BK channels, suggesting that the stimulatory effect of CO on the BK channels was, at least partially, induced by a cGMP-independent mechanism. Western blot demonstrated that heme oxygenase type 1 (HO-1) and HO-2 were expressed in the kidney. Moreover, a high-K (HK) intake increased the expression of HO-1 but not HO-2 in the kidney. A HK intake also increased renal HO activity defined by NADPH-dependent CO generation following addition of heme in the cell lysate from renal cortex and outer medulla. The role of HO in regulating BK channel activity in the CCD was also suggested by experiments in which application of hemin increased the BK channels. The stimulatory effect of hemin on the BK channels was blocked by SnMP, a HO inhibitor. But, adding CORM3 was still able to activate the BK channels in the presence of SnMP. We conclude that CO activates the BK channels, at least partially, through a NO-cGMP-independent pathway and that HO plays a role in mediating the effect of HK intake on the BK channels in the CCD. PMID

  14. Ca2+ current-gated focal and local Ca2+ release in rat atrial myocytes: evidence from rapid 2-D confocal imaging.

    PubMed

    Woo, Sun-Hee; Cleemann, Lars; Morad, Martin

    2002-09-01

    In atrial myocytes immunocytochemistry has shown two groups of ryanodine receptors (RyRs): those at the periphery colocalized with dihydropyridine receptors (DHPRs) and those at the cell interior not associated with DHPRs. The extent to which the two sets of RyRs are controlled by Ca2+ current (I(Ca)) or Ca2+ diffusion remains to be determined. Here, using rapid (240 Hz) two-dimensional confocal Ca2+ imaging in rat atrial myocytes, we examine directly the role of I(Ca) on the two-dimensional patterns of local and focal Ca2+ releases. I(Ca) evoked peripheral Ca2+ release within 1-4 ms, causing a rapid monophasic local rise of Ca2+, which then propagated into the cell interior along sarcomeric lines (approximately 2 microm) with a velocity of approximately 230 microm s(-1), even though we found no evidence for organized t-tubules using di-8-ANEPPS staining. I(Ca)-triggered Ca2+ release in the cell centre, on the other hand, had both a rapid (12 ms) and slower delayed components (12-50 ms). The voltage dependence of peripheral Ca2+ release and the two components of central release was bell shaped, and the magnitude of each release component was linearly related to I(Ca). Premature termination (2-10 ms) of I(Ca) was equally effective in abbreviating both the peripheral and slow central Ca2+ release. High concentration of Ca2+ buffers (2-5 mM EGTA plus 1 mM fluo-3) completely abolished the I(Ca)-gated propagation wave and the slow delayed component of Ca2+ release, but had little or no effect on the rapid component of central release. The efficacy of I(Ca) to trigger Ca2+ release in periphery of the myocyte was approximately 5 times higher than in the centre, consistent with the smaller measured central Ca2+ release. The quantification of central Ca2+ release as a function of peripheral release suggests a cooperative gating mechanism(s) for central release. These findings indicate that both I(Ca) and diffusion of Ca2+ from the peripheral sites contribute to the gating

  15. Measurement of HO2 chemical kinetics with a new detection method

    NASA Technical Reports Server (NTRS)

    Lee, Long C.; Suto, Masako

    1986-01-01

    Reaction rate constants of HO2+O3 were measured at various temperatures using a newly developed HO2 detection method. HO2 was detected by the OH(A-X) emission produced from photodissociative excitation of HO2 at 147 nm. In order to examine the possible interference of other emitting species with the HO2 detection, the photoexcitation processes of all the chemical species existing in the discharge flow tube were also investigated. The results are summarized.

  16. Clopidogrel Protects Endothelium by Hindering TNFα-Induced VCAM-1 Expression through CaMKKβ/AMPK/Nrf2 Pathway

    PubMed Central

    Yang, Huabing; Zhao, Pengjun; Tian, Shiliu

    2016-01-01

    Clopidogrel (INN), an oral antiplatelet drug, has been revealed to have a number of biological properties, for instance, anti-inflammation and antioxidation. Oxidative stress plays an imperative role in inflammation, diabetes mellitus, atherosclerosis, and cancer. In the present study, human aortic endothelial cells (HAECs) were employed to explore the anti-inflammatory activity of INN. INN reduced TNFα-induced reactive oxygen species (ROS) generation and time-dependently prompted the expression and activity of heme oxygenase 1 (HO-1). Cellular glutathione (GSH) levels were augmented by INN. shHO-1 blocked the INN suppression of TNFα-induced HL-60 cell adhesion. The CaMKKβ/AMPK pathway and Nrf2 transcriptional factor were implicated in the induction of HO-1 by INN. Additionally, TNFα dramatically augmented VCAM-1 expression at protein and mRNA levels. INN treatment strikingly repressed TNFα-induced expression of VCAM-1 and HL-60 cell adhesion. Compound C, an AMPK inhibitor, and shNrf2 abolished TNFα-induced expression of VCAM-1 and HL-60 cell adhesion. Our data suggest that INN diminishes TNFα-stimulated VCAM-1 expression at least in part via HO-1 induction, which is CaMKKβ/AMPK pathway-dependent. PMID:26824050

  17. QM/MM calculations with deMon2k.

    PubMed

    Salahub, Dennis R; Noskov, Sergei Yu; Lev, Bogdan; Zhang, Rui; Ngo, Van; Goursot, Annick; Calaminici, Patrizia; Köster, Andreas M; Alvarez-Ibarra, Aurelio; Mejía-Rodríguez, Daniel; Řezáč, Jan; Cailliez, Fabien; de la Lande, Aurélien

    2015-01-01

    The density functional code deMon2k employs a fitted density throughout (Auxiliary Density Functional Theory), which offers a great speed advantage without sacrificing necessary accuracy. Powerful Quantum Mechanical/Molecular Mechanical (QM/MM) approaches are reviewed. Following an overview of the basic features of deMon2k that make it efficient while retaining accuracy, three QM/MM implementations are compared and contrasted. In the first, deMon2k is interfaced with the CHARMM MM code (CHARMM-deMon2k); in the second MM is coded directly within the deMon2k software; and in the third the Chemistry in Ruby (Cuby) wrapper is used to drive the calculations. Cuby is also used in the context of constrained-DFT/MM calculations. Each of these implementations is described briefly; pros and cons are discussed and a few recent applications are described briefly. Applications include solvated ions and biomolecules, polyglutamine peptides important in polyQ neurodegenerative diseases, copper monooxygenases and ultra-rapid electron transfer in cryptochromes. PMID:25786164

  18. The same-source parallel MM{sub 5}.

    SciTech Connect

    Michalakes, J.

    1999-08-23

    The set of architectures available to users of the Penn State/NCAR MM5 has been expanded to included distributed-memory parallel computers, providing cost-effective scalable performance and memory capacity for large problem sizes. The same-source approach uses high-level parallel library and source-translation technology for adapting MM5, simplifying maintenance and allowing new physics modules to be incorporated without modification. The approach facilitates maintenance of the DM-parallel option to MM5 as an option within the official version, rather than as a separate stand-alone version. As a result, the DM-parallel option to MM5 (now at Version 3.1) has been a part of six subsequent model releases since MM5 Version 2.8 in March 1998. The same-source approach is applicable to other, similarly constructed codes when there is a need or desire to develop the code for distributed memory parallel machines without impacting the pre-existing source code. The approach is also compatible with pre-existing loop-level multithreading directives so that the code will run in distributed-memory/shared-memory mode on SMP clusters.

  19. CMOS mm-wave transceivers for Gbps wireless communication

    NASA Astrophysics Data System (ADS)

    Baoyong, Chi; Zheng, Song; Lixue, Kuang; Haikun, Jia; Xiangyu, Meng; Zhihua, Wang

    2016-07-01

    The challenges in the design of CMOS millimeter-wave (mm-wave) transceiver for Gbps wireless communication are discussed. To support the Gbps data rate, the link bandwidth of the receiver/transmitter must be wide enough, which puts a lot of pressure on the mm-wave front-end as well as on the baseband circuit. This paper discusses the effects of the limited link bandwidth on the transceiver system performance and overviews the bandwidth expansion techniques for mm-wave amplifiers and IF programmable gain amplifier. Furthermore, dual-mode power amplifier (PA) and self-healing technique are introduced to improve the PA's average efficiency and to deal with the process, voltage, and temperature variation issue, respectively. Several fully-integrated CMOS mm-wave transceivers are also presented to give a short overview on the state-of-the-art mm-wave transceivers. Project supported in part by the National Natural Science Foundation of China (No. 61331003).

  20. The brightness temperature of Mercury at mm-wavelengths

    NASA Astrophysics Data System (ADS)

    Greve, A.; Thum, C.; Moreno, R.; Yan, N.

    2009-02-01

    We present observations of Mercury made with the IRAM 30-m telescope at 3, 2 and 1.3 mm wavelength (90, 150 and 230 GHz) during the years 1985-2005; we derive from these data the disk-averaged brightness temperatures. The observations at 3 mm combined with those by Epstein & Andrew allow a separation of the data into 40° wide longitude intervals and by this an investigation of the disk-averaged brightness temperature with Mercury's longitude. From the new mm-wavelength data, and data taken from the literature, we derive the disk-averaged brightness temperature as a function of wavelength. On Mercury's night side a significant decrease in brightness temperature occurs towards shorter wavelengths. We use the three surface models (A,B,C) discussed by Mitchell & de Pater and calculate for the cool and hot surface region the corrresponding diurnal variation of the disk-averaged brightness temperature at 90 GHz. For the same models we calculate the variation of the disk-averaged brightness temperature with wavelength between 1.3 mm and 37 mm, on Mercury's midnight side and noon side. Although the scatter in the observations is large, there seems to be a marginally better agreement with model B and A.

  1. The plasma-membrane Ca2+-ATPase of Leishmania donovani is an extrusion pump for Ca2+.

    PubMed Central

    Mandal, D; Mukherjee, T; Sarkar, S; Majumdar, S; Bhaduri, A

    1997-01-01

    Controlled exposure of Leishmania donovani promastigotes to hypotonic shock results in the formation of deflagellated unsealed ghosts of original polarity that largely retain the pellicular microtubular structure associated with plasma membrane of the parasite. Gentle shearing followed by suspension of the purified membrane in appropriate isotonic buffer containing Mg2+ (4mM) results in the formation of sealed everted vesicles. The presence of Mg2+ (4 mM) appears to be essential for efficient sealing and also to prevent leakiness. ATP-dependent Ca2+ accumulation can be demonstrated in these vesicles Km values for Ca2+ and ATP were 125 nM and 0.8 mM respectively. The accumulated Ca2+ reaches a concentration of 1.1 mM. Ca2+ uptake is completely inhibited by vanadate (40 microM) and several thiol-modifying agents. Using 5,5'-dithiobis-(2-nitrobenzoic acid) as the modifying agent, an excellent correlation between loss of enzyme activity and transport capability and their parallel regeneration in the presence of 2 mM dithiothreitol was demonstrated. Using 2'.7-bis(carboxyethyl)-5(6)-carboxyfluorescein as the fluorescent pH probe, it was observed that Ca2+ entry into the vesicles is accompanied by an outward movement of H+ from the vesicles. Taken together, this paper establishes that the high-affinity transmembrane Ca2+-ATPase [Ghosh, Ray, Sarkar and Bhaduri (1990) J. Biol. Chem. 265, 11345-11351; Majumdar, Mukherjee, Ray and Bhaduri (1992) J. Biol. Chem. 267, 18440-18446] is an extrusion pump for Ca2+ in this human pathogen. PMID:9078270

  2. IRRS, UV-Vis-NIR absorption and photoluminescence upconversion in Ho 3+-doped oxyfluorophosphate glasses

    NASA Astrophysics Data System (ADS)

    Karmakar, Basudeb

    2005-09-01

    Infrared reflection spectroscopic (IRRS), ultraviolet-visible-near infrared (UV-Vis-NIR) absorption and photoluminescence upconversion properties with special emphasis on the spectrochemistry of the oxyfluorophosphate (oxide incorporated fluorophosphates) glasses of the Ba(PO 3) 2-AlF 3-CaF 2-SrF 2-MgF 2-Ho 2O 3 system have been studied with different concentrations (0.1, 0.3 and 1.0 mol%) of Ho 2O 3. IRRS spectral band position and intensity of Ho 3+ ion doped oxyfluorophosphate glasses have been discussed in terms of reduced mass and force constant. UV-Vis-NIR absorption band position has been justified with quantitative calculation of nephelauxetic parameter and covalent bonding characteristics of the host. NIR to visible upconversion has been investigated by exciting at 892 nm at room temperature. Three upconverted bands originated from the 5F 3→ 5I 8, ( 5S 2, 5F 4)→ 5I 8 and 5F 5→ 5I 8 transitions have found to be centered at 491 nm (blue, medium), 543 nm (green, very strong) and 658 nm (red, weak), respectively. These bands have been justified from the evaluation of the absorption, normal (down conversion) fluorescence and excitation spectra. The upconversion processes have been explained by the excited state absorption (ESA), energy transfer (ET) and cross relaxation (CR) mechanisms involving population of the metastable (storage) energy levels by multiphonon deexcitation effect. It is evident from the IRRS study that the upconversion phenomena are expedited by the low multiphonon relaxation rate in oxyfluorophosphate glasses owing to their high intense low phonon energy (˜600 cm -1) which is very close to that of fluoride glasses (500-600 cm -1).

  3. Heterogeneous Uptake of HO2 Radicals onto Atmospheric Aerosols

    NASA Astrophysics Data System (ADS)

    George, I. J.; Matthews, P. S.; Brooks, B.; Goddard, A.; Whalley, L. K.; Baeza-Romero, M. T.; Heard, D. E.

    2011-12-01

    The hydroxyl (OH) and hydroperoxyl (HO2) radicals, together known as HOx, play a vital role in atmospheric chemistry by controlling the oxidative capacity of the troposphere. The atmospheric lifetime and concentrations of many trace reactive species, such as volatile organic compounds (VOCs), are determined by HOx radical levels. Therefore, the ability to accurately predict atmospheric HOx concentrations from a detailed knowledge of their sources and sinks is a very useful diagnostic tool to assess our current understanding of atmospheric chemistry. Several recent field studies have observed significantly lower concentrations of HO2 radicals than predicted using box models, where HO2 loss onto aerosols was suggested as a possible missing sink [1, 2]. However, the mechanism on HO2 uptake onto aerosols and its impact on ambient HOx levels are currently not well understood. To improve our understanding of this process, we have conducted laboratory experiments to measure HO2 uptake coefficients onto submicron aerosol particles. The FAGE (Fluorescence Assay by Gas Expansion) technique, a highly sensitive laser induced fluorescence based detection method, was used to monitor HO2 uptake kinetics onto aerosol particles in an aerosol flow tube. The application of the FAGE technique allowed for kinetic experiments to be performed under low HO2 concentrations, i.e. [HO2] < 109 molecules cm-3. HO2 radicals were produced by the photolysis of water vapour in the presence of O2 and aerosol particles were produced either by atomizing dilute salt solutions or by homogeneous nucleation. HO2 uptake coefficients (γ) have been measured for single-component solid and aqueous inorganic salt and organic aerosol particles with a wide range of hygroscopicities. HO2 uptake coefficients on solid particles were below the detection limit (γ < 0.001), whereas on aqueous aerosols uptake coefficients were somewhat larger (γ = 0.001 - 0.008). HO2 uptake coefficients were highest on aerosols

  4. Cytosolic and mitochondrial [Ca2+] in whole hearts using indo-1 acetoxymethyl ester: effects of high extracellular Ca2+.

    PubMed Central

    Schreur, J H; Figueredo, V M; Miyamae, M; Shames, D M; Baker, A J; Camacho, S A

    1996-01-01

    Assessment of free cytosolic [Ca2+] ([Ca2+]c) using the acetoxymethyl ester (AM) form of indo-1 may be compromised by loading of indo-1 into noncytosolic compartments, primarily mitochondria. To determine the fraction of noncytosolic fluorescence in whole hearts loaded with indo-1 AM, Mn2+ was used to quench cytosolic fluorescence. Residual (i.e., noncytosolic) fluorescence was subtracted from the total fluorescence before calculating [Ca2+]c. Noncytosolic fluorescence was used to estimate mitochondrial [Ca2+]. In hearts paced at 5 Hz (N = 17), noncytosolic fluorescence was 0.61 +/- 0.06 and 0.56 +/- 0.07 of total fluorescence at lambda 385 and lambda 456, respectively. After taking into account noncytosolic fluorescence, systolic and diastolic [Ca2+]c was 673 +/- 72 and 132 +/- 9 nM, respectively, noncytosolic [Ca2+] was 183 +/- 36 nM and increased to 272 +/- 12 when extracellular Ca2+ was increased from 2 to 6 mM. This increase in noncytosolic [Ca2+] was inhibited by ruthenium red, a blocker of Ca2+ uptake by mitochondria. We conclude that cytosolic and mitochondrial [Ca2+] can be determined in whole hearts loaded with indo-1 AM by using Mn2+ to quench cytosolic fluorescence. PMID:8744296

  5. Engineering Strong Interactions Between mm-wave and Optical Photons

    NASA Astrophysics Data System (ADS)

    Stone, Mark; Suleymanzade, Aziza; Estes, Jeremy; Eustice, Scott; Schuster, David; Simon, Jonathan

    2016-05-01

    We propose an atomic interface of Rydberg atoms as a means of engineering effective strong interactions between single mm-wave and optical photons. The atomic sample resides at the intersection of a high-finesse optical cavity and a superconducting mm-wave cavity, where it can coherently interact with photons of both regimes. The use of mm-wave (100 GHz) frequencies allows strong coupling at higher temperatures and with less sensitivity to stray electric fields. A hybrid cryogenic vacuum chamber at 4 Kelvin enables access to superconductivity as well as a UHV environment with optical access necessary for cold atom experiments. Strong interactions between these separate quantum degrees of freedom has important applications in quantum computing as well as simulation of many-body interacting systems.

  6. QM/MM X-ray Refinement of Zinc Metalloenzymes

    PubMed Central

    Li, Xue; Hayik, Seth A.; Merz, Kenneth M.

    2010-01-01

    Zinc metalloenzymes play an important role in biology. However, due to the limitation of molecular force field energy restraints used in X-ray refinement at medium or low resolutions, the precise geometry of the zinc coordination environment can be difficult to distinguish from ambiguous electron density maps. Due to the difficulties involved in defining accurate force fields for metal ions, the QM/MM (Quantum-Mechanical /Molecular-Mechanical) method provides an attractive and more general alternative for the study and refinement of metalloprotein active sites. Herein we present three examples that indicate that QM/MM based refinement yields a superior description of the crystal structure based on R and Rfree values and on the inspection of the zinc coordination environment. It is concluded that QM/MM refinement is a useful general tool for the improvement of the metal coordination sphere in metalloenzyme active sites. PMID:20116858

  7. Studies of Ca{sup 2+} binding in spinach photosytem II using {sup 45}Ca{sup 2+}

    SciTech Connect

    Aedelroth, P.; Lindberg, K.; Andreasson, L.E.

    1995-07-18

    The Ca{sup 2+}-binding properties of photosystem II were investigated with radioactive {sup 45}Ca{sup 2+}. PS II membranes, isolated from spinach grown on a medium containing {sup 45}Ca{sup 2+}, contained 1.5 Ca{sup 2+} per PS II unit. Approximately half of the incorporated radioactivity was lost after incubation for 30 h in nonradioactive buffer. About 1 Ca{sup 2+}/PS II bound slowly to Ca{sup 2+}-depleted membranes in the presence of the extrinsic 16- and 23-kDa polypeptides in parallel with restoration of oxygen-evolving activity. The binding was heterogeneous with dissociation constants of 60 {mu}M (0.7 Ca{sup 2+}/PS II) and 1.7 mM (0.3 Ca{sup 2+}/ PS II), respectively, which could reflect different affinities of the dark-stable S-states for Ca{sup 2+}. The reactivation of oxygen-evolving activity closely followed the binding of Ca{sup 2+}, showing that a single exchangeable Ca{sup 2+} per PS II is sufficient for the water-splitting reaction to function. In PS II, depleted of the 16- and 23-kDa polypeptides, about 0.7 exchangeable Ca{sup 2+}/PS II binds with a dissociation constant of 26 {mu}M, while 0.3 Ca{sup 2+} binds with a much weaker affinity (K{sub d} > 0.5 mM). The rate of binding of Ca{sup 2+} in the absence of the two extrinsic polypeptides was significantly higher than with the polypeptides bound. The rate of dissociation of bound Ca{sup 2+} in the dark, which had a half-time of about 80 h in intact PS H, increased in the absence of the 16-and 23-kDa polypeptides and showed a further increase after the additional removal of the 33-kDa protein and manganese. The rate of dissociation was also significantly faster in weak light than in the dark. Removal of the 33-kDa donor-side polypeptide together with the two lighter ones led to a reduction in the amount of bound Ca{sup 2+}, while practically no Ca{sup 2+} bound after treatments to dissociate also the manganese of the water-oxidizing site. 34 refs., 9 figs., 2 tabs.

  8. Laparoscopic 5-mm Trocar Site Herniation and Literature Review

    PubMed Central

    Minikel, Laura; Zaritsky, Eve

    2011-01-01

    Objective: To evaluate the evidence for fascial closure of 5-mm laparoscopic trocar sites. Methods: We conducted electronic database searches of PubMed and the Cochrane Library for articles published between November 2008 and December 2010. We used the keywords trocar hernia, trocar-site hernia, laparoscopic hernia, trocar port-site hernia, laparoscopic port-site hernia. Prospective and retrospective case series, randomized trials, literature reviews, and randomized animal studies of trocar hernias on abdominal wall defects from gynecologic, urologic, and general surgery literature were reviewed. The Cochrane Database was reviewed for pertinent studies. Metaanalysis was not possible due to the significant heterogeneity between studies and lack of randomized trials large enough to assess the incidence of this rare complication. Results: Trocar-site hernias are a rare but known complication of laparoscopic surgery. Trocar size ≥10mm is associated with an increased rate of hernia development. Currently, the accepted gynecologic surgical practice is closure of fascial incisions ≥10mm, while incisions <10mm do not require closure. However, large prospective and retrospective case series reports from general surgery and urology literature support nonclosure of blunt or radially dilating trocars in paramedian sites. Expert opinion and small case reports suggest that in cases of prolonged manipulation of 5-mm trocar sites the surgeon should consider fascial closure, because extension of the initial incision may have occurred. Conclusion: There is no evidence to recommend routine closure of 5-mm trocar incisions; the choice should continue to be left to the discretion of the individual surgeon. PMID:21902958

  9. 450mm wafer patterning with jet and flash imprint lithography

    NASA Astrophysics Data System (ADS)

    Thompson, Ecron; Hellebrekers, Paul; Hofemann, Paul; LaBrake, Dwayne L.; Resnick, Douglas J.; Sreenivasan, S. V.

    2013-09-01

    The next step in the evolution of wafer size is 450mm. Any transition in sizing is an enormous task that must account for fabrication space, environmental health and safety concerns, wafer standards, metrology capability, individual process module development and device integration. For 450mm, an aggressive goal of 2018 has been set, with pilot line operation as early as 2016. To address these goals, consortiums have been formed to establish the infrastructure necessary to the transition, with a focus on the development of both process and metrology tools. Central to any process module development, which includes deposition, etch and chemical mechanical polishing is the lithography tool. In order to address the need for early learning and advance process module development, Molecular Imprints Inc. has provided the industry with the first advanced lithography platform, the Imprio® 450, capable of patterning a full 450mm wafer. The Imprio 450 was accepted by Intel at the end of 2012 and is now being used to support the 450mm wafer process development demands as part of a multi-year wafer services contract to facilitate the semiconductor industry's transition to lower cost 450mm wafer production. The Imprio 450 uses a Jet and Flash Imprint Lithography (J-FILTM) process that employs drop dispensing of UV curable resists to assist high resolution patterning for subsequent dry etch pattern transfer. The technology is actively being used to develop solutions for markets including NAND Flash memory, patterned media for hard disk drives and displays. This paper reviews the recent performance of the J-FIL technology (including overlay, throughput and defectivity), mask development improvements provided by Dai Nippon Printing, and the application of the technology to a 450mm lithography platform.

  10. Magnetic remanence in Yb14-xRExMnSb11 (RE=Tb, Dy, Ho) single crystals

    NASA Astrophysics Data System (ADS)

    Grebenkemper, Jason H.; Hu, Yufei; Abdusalyamova, M. N.; Makhmudov, F. A.; Kauzlarich, Susan M.

    2016-06-01

    Single crystals of Yb14-xRExMnSb11 (x~0.1, 0.4; RE = Tb, Dy, Ho) have been prepared as a solid solution by Sn flux reactions of the elements. They crystallize in the Ca14AlSb11 structure type in the I41/acd space group. The RE3+preferentially substitutes on the Yb(1) site which is the smallest volume Yb containing polyhedron. In the case of Ho3+, a small amount of Ho3+ also substitutes on the Yb(4) site. The ferromagnetic ordering temperature of Yb14MnSb11 is reduced from 53 K to 41 K as x increases and dependent on the identity of the RE. This is attributed to the reduction in carriers and reduced screening of the Mn2+ local moment. The effective moments, μeff, agree well with the calculated moments assuming the RE substitutes as a trivalent cation. The largest coercive field is observed for RE = Dy (1000 Oe). For the maximum x of Yb14-xRExMnSb11 there are enough carriers for the Ruderman-Kittel-Kasuya-Yosida (RKKY) mechanism of magnetic coupling via conduction electrons to still be valid in describing the ferromagnetic ordering.

  11. Absolute brightness temperature measurements at 2.1-mm wavelength

    NASA Technical Reports Server (NTRS)

    Ulich, B. L.

    1974-01-01

    Absolute measurements of the brightness temperatures of the Sun, new Moon, Venus, Mars, Jupiter, Saturn, and Uranus, and of the flux density of DR21 at 2.1-mm wavelength are reported. Relative measurements at 3.5-mm wavelength are also preented which resolve the absolute calibration discrepancy between The University of Texas 16-ft radio telescope and the Aerospace Corporation 15-ft antenna. The use of the bright planets and DR21 as absolute calibration sources at millimeter wavelengths is discussed in the light of recent observations.

  12. Full-mesh optical backplane with standard MM fiber ribbons

    NASA Astrophysics Data System (ADS)

    Ferrario, M.; Coviello, D.; Boffi, P.; Martinelli, M.; Basile, V.; Fassi, I.; Falcucci, M.; Renghini, C.; Scalmati, Paolo

    2016-03-01

    A new optical backplane solution is proposed for high-capacity ICT apparatus. A modular, scalable and full-mesh bandwidth-upgradable optical interconnection between optoelectronic boards is guaranteed thanks to an optimized layout of standard MM 12-fiber ribbons which divides the overall backplane into several independent optical sub-circuits. The novel automated assembly procedure of fiber ribbons inside sub-circuits with a robotic work-cell is described. System validation of the optical backplane performed with commercially available MM 12-fiber transceivers @10Gb/s proved the feasibility of the proposed solution for future optical interconnections with terabit overall capacity.

  13. Novel Processing of 81-mm Cu Shaped Charge Liners

    SciTech Connect

    Schwartz, A; Korzekwa, D

    2002-01-16

    A seven-step procedure was developed for producing shaped charge liner blanks by back extrusion at liquid nitrogen temperatures. Starting with a 38.1-mm diameter, 101.6-mm long cylinder at 77K, three forging steps with a flat-top die are required to produce the solid cone while maintaining low temperature. The solid cone is forged in four individual back extrusions at 77K to produce the rough liner blank. This procedure is capable of being run in batch processes to improve the time efficiency.

  14. Performance evaluation of 4.75-mm NMAS superpave mixture

    NASA Astrophysics Data System (ADS)

    Rahman, Farhana

    A Superpave asphalt mixture with 4.75-mm nominal maximum aggregate size (NMAS) is a promising, low-cost pavement preservation treatment for agencies such as the Kansas Department of Transportation (KDOT). The objective of this research study is to develop an optimized 4.75-mm NMAS Superpave mixture in Kansas. In addition, the study evaluated the residual tack coat application rate for the 4.75-mm NMAS mix overlay. Two, hot-in-place recycling (HIPR) projects in Kansas, on US-160 and K-25, were overlaid with a 15- to 19-mm thick layer of 4.75-mm NMAS Superpave mixture in 2007. The field tack coat application rate was measured during construction. Cores were collected from each test section for Hamburg wheel tracking device (HWTD) and laboratory bond tests performed after construction and after one year in service. Test results showed no significant effect of the tack coat application rate on the rutting performance of rehabilitated pavements. The number of wheel passes to rutting failure observed during the HWTD test was dependent on the aggregate source as well as on in-place density of the cores. Laboratory pull-off tests showed that most cores were fully bonded at the interface of the 4.75-mm NMAS overlay and the HIPR layer, regardless of the tack application rate. The failure mode during pull-off tests at the HMA interface was highly dependent on the aggregate source and mix design of the existing layer material. This study also confirmed that overlay construction with a high tack coat application rate may result in bond failure at the HMA interface. Twelve different 4.75-mm NMAS mix designs were developed using materials from the aforementioned but two binder grades and three different percentages of natural (river) sand. Laboratory performance tests were conducted to assess mixture performance. Results show that rutting and moisture damage potential in the laboratory depend on aggregate type irrespective of binder grade. Anti-stripping agent affects moisture

  15. Time-dependent changes in Ca2+ sensitivity during phasic contraction of canine antral smooth muscle.

    PubMed Central

    Ozaki, H; Gerthoffer, W T; Publicover, N G; Fusetani, N; Sanders, K M

    1991-01-01

    1. Relationships between cytosolic Ca2+ concentration ([Ca2+]cyt), myosin light chain (MLC) phosphorylation and muscle tension were examined in circular smooth muscle of canine gastric antrum. 2. Electrical slow waves induced a transient increase in [Ca2+]cyt and muscle tension. [Ca2+]cyt increased before the initiation of contraction and reached a maximum before the peak of the phasic contractions. Following the first Ca2+ transient, a second rise in [Ca2+]cyt was often observed. The second Ca2+ transient was of similar magnitude to the first, but only in some cases was this increase in [Ca2+]cyt associated with a second phase of contraction. Relaxation occurred more rapidly than the restoration of resting levels of [Ca2+]cyt. 3. Acetylcholine (ACh; 3 x 10(-7) M) increased the amplitude of Ca2+ transients, caused MLC phosphorylation and increased the force of contraction. The decay of contraction and MLC dephosphorylation preceded that of [Ca2+]cyt. 4. Increasing external K+ (to 25-40 mM) caused a sustained increase in [Ca2+]cyt, but little change in resting tension. This suggests that the Ca2+ sensitivity decreased as [Ca2+]cyt increased. Increasing K+ to 59.5 mM further increased the level of [Ca2+]cyt, induced MLC phosphorylation and caused a transient contraction. When normal levels of K+ were restored, the rates of MLC dephosphorylation and relaxation exceeded the rate of decay in [Ca2+]cyt. 5. Removal of external Ca2+ in depolarized muscles decreased [Ca2+]cyt below the resting level without affecting resting tension. Readmission of Ca2+ to depolarized muscles caused force to develop at [Ca2+]cyt levels below the original resting level, suggesting that Ca2+ sensitivity was increased when the resting level of [Ca2+]cyt was decreased. 6. The phosphatase inhibitor, calyculin-A (10(-6) M), induced tonic contraction and MLC phosphorylation without an increase in [Ca2+]cyt. During these contractures, electrical activity caused transient increases in [Ca2+]cyt and

  16. Mitochondrial Ca2+-induced Ca2+ Release Mediated by the Ca2+ Uniporter

    PubMed Central

    Montero, Mayte; Alonso, Maria Teresa; Albillos, Almudena; García-Sancho, Javier; Alvarez, Javier

    2001-01-01

    We have reported that a population of chromaffin cell mitochondria takes up large amounts of Ca2+ during cell stimulation. The present study focuses on the pathways for mitochondrial Ca2+ efflux. Treatment with protonophores before cell stimulation abolished mitochondrial Ca2+ uptake and increased the cytosolic [Ca2+] ([Ca2+]c) peak induced by the stimulus. Instead, when protonophores were added after cell stimulation, they did not modify [Ca2+]c kinetics and inhibited Ca2+ release from Ca2+-loaded mitochondria. This effect was due to inhibition of mitochondrial Na+/Ca2+ exchange, because blocking this system with CGP37157 produced no further effect. Increasing extramitochondrial [Ca2+]c triggered fast Ca2+ release from these depolarized Ca2+-loaded mitochondria, both in intact or permeabilized cells. These effects of protonophores were mimicked by valinomycin, but not by nigericin. The observed mitochondrial Ca2+-induced Ca2+ release response was insensitive to cyclosporin A and CGP37157 but fully blocked by ruthenium red, suggesting that it may be mediated by reversal of the Ca2+ uniporter. This novel kind of mitochondrial Ca2+-induced Ca2+ release might contribute to Ca2+ clearance from mitochondria that become depolarized during Ca2+ overload. PMID:11160823

  17. Optical Characterization of the Ho^3+ Complex in HEMA

    NASA Astrophysics Data System (ADS)

    Rodriguez, Manuel, III; Sardar, Dhiraj; Nash, Kelly; Yow, Raylon; Gruber, John

    2007-10-01

    The spectroscopic properties of the Ho^3+ complex embedded in 2-hydroxyethyl methacrylate (HEMA) are investigated. The intensities of the room temperature absorption spectra of the Ho^3+(4f^10) transitions in Ho(NO3)3.5H2O:HEMA have been analyzed using the Judd-Ofelt (J-O) model to obtain the phenomenological intensity parameters, φ2, φ4, and φ6. These parameters are used to calculate the spontaneous emission probabilities, radiative lifetimes, and branching ratios of the Ho^3+ transitions from the upper multiplet manifolds to the corresponding lower-lying multiplet manifolds of ^2S+1LJ Ho^3+(4f^10), which include ^5G4+^3K7^(2), ^5G5, ^5G6+^5F1, ^5F2+^3K8^(2), ^5F3, ^5F4+^5S2, and ^5F5. The predicted room temperature fluorescence lifetime of ^5I7 to ^5I8 is about 0.5 ms, suggesting a reasonably strong interaction between the complex and the polymer. A comparative study of Ho^3+(4f^10) ions in different host materials suggests that Ho(NO3)3.5H2O:HEMA could be an excellent candidate for certain applications such as narrow band pass filters, especially in the visible-to-near infrared region of the spectrum.

  18. Anomalous temperature dependence of the lattice parameters in HoPO{sub 4} and HoVO{sub 4}: Rare earth quadrupolar effects

    SciTech Connect

    Skanthakumar, S.; Loong, C.K.; Soderholm, L.; Nipko, J.; Richardson, J.W. Jr.; Abraham, M.M.; Boatner, L.A.

    1994-07-01

    The temperature dependence of the lattice parameters in tetragonal HoPO{sub 4} and HoVO{sub 4} was measured using neutron powder-diffraction techniques. Below about 100K, the lattice parameter a of HoPO{sub 4} increases with decreasing temperature while c decreases. In HoVO{sub 4}, the above behavior is reversed, that is, a decreases with decreasing temperature while c increases. Similar measurements on nonmagnetic LUP0{sub 4} and LuVO{sub 4} do not show any anomaly. This observation indicates that the unusual temperature dependence of the lattice constants is magnetic in origin. It can be explained in terms of a Ho{sup 3+} quadrupole interaction with the crystalline lattice. In particular, the calculated electronically-generated quadrupole moment of the Ho{sup 3+} in HoPO{sub 4} and HoVO{sub 4} exhibits a temperature dependence similar to that observed in the lattice parameters.

  19. Voltage-Induced Ca2+ Release in Postganglionic Sympathetic Neurons in Adult Mice

    PubMed Central

    Sun, Hong-Li; Tsai, Wen-Chin; Li, Bai-Yan; Tao, Wen; Chen, Peng-Sheng; Rubart, Michael

    2016-01-01

    Recent studies have provided evidence that depolarization in the absence of extracellular Ca2+ can trigger Ca2+ release from internal stores in a variety of neuron subtypes. Here we examine whether postganglionic sympathetic neurons are able to mobilize Ca2+ from intracellular stores in response to depolarization, independent of Ca2+ influx. We measured changes in cytosolic ΔF/F0 in individual fluo-4 –loaded sympathetic ganglion neurons in response to maintained K+ depolarization in the presence (2 mM) and absence of extracellular Ca2+ ([Ca2+]e). Progressive elevations in extracellular [K+]e caused increasing membrane depolarizations that were of similar magnitude in 0 and 2 mM [Ca2+]e. Peak amplitude of ΔF/F0 transients in 2 mM [Ca2+]e increased in a linear fashion as the membrane become more depolarized. Peak elevations of ΔF/F0 in 0 mM [Ca2+]e were ~5–10% of those evoked at the same membrane potential in 2 mM [Ca2+]e and exhibited an inverse U-shaped dependence on voltage. Both the rise and decay of ΔF/F0 transients in 0 mM [Ca2+]e were slower than those of ΔF/F0 transients evoked in 2 mM [Ca2+]e. Rises in ΔF/F0 evoked by high [K+]e in the absence of extracellular Ca2+ were blocked by thapsigargin, an inhibitor of endoplasmic reticulum Ca2+ ATPase, or the inositol 1,4,5-triphosphate (IP3) receptor antagonists 2-aminoethoxydiphenyl borate and xestospongin C, but not by extracellular Cd2+, the dihydropyridine antagonist nifedipine, or by ryanodine at concentrations that caused depletion of ryanodine-sensitive Ca2+ stores. These results support the notion that postganglionic sympathetic neurons possess the ability to release Ca2+ from IP3-sensitive internal stores in response to membrane depolarization, independent of Ca2+ influx. PMID:26859144

  20. Effects of trimebutine on cytosolic Ca2+ and force transitions in intestinal smooth muscle.

    PubMed

    Nagasaki, M; Kobayashi, T; Tamaki, H

    1991-04-01

    The effects of trimebutine maleate on cytosolic free Ca2+ and force transitions in the guinea-pig taenia cecum were studied by fura-2 fluorometry and tension recording. The addition of 80 mM K+ induced a transient increase in cytosolic free Ca2+ concentration ([Ca2+]i) and tension, followed by a sustained increase. Trimebutine (10 microM) suppressed both [Ca2+]i elevation and tension development. The tonic responses were more potently inhibited than the phasic responses. Phasic components gradually increased as the added K+ increased (10-40 mM). The relationship between the peak increases in [Ca2+]i and tension was not affected by trimebutine (10 microM). This means that trimebutine does not affect the Ca2+ sensitivity of contractile elements. In a high K+ and Ca(2+)-free medium, carbachol (10 microM) or caffeine (30 mM) caused transient [Ca2+]i elevation and tension development in the smooth muscle. Trimebutine (10 microM) decreased the amplitude of both responses. Trimebutine (10 microM) inhibited the spontaneous fluctuations in [Ca2+]i and motility of taenia cecum in the presence of tetrodotoxin (TTX; 0.3 microM). These results suggest that trimebutine has two types of inhibitory actions on intestinal smooth muscle; one, the inhibition of Ca2+ influx through voltage-dependent calcium channels, and the other, the inhibition of Ca2+ release from intracellular storage sites. PMID:1868878

  1. Extracellular calcium and CaSR drive osteoinduction in mesenchymal stromal cells.

    PubMed

    González-Vázquez, Arlyng; Planell, Josep A; Engel, Elisabeth

    2014-06-01

    Bone is the main store of calcium and progenitor cells in the body. During the resorption process, the local calcium concentration reaches 8-40mM, and the surrounding cells are exposed to these fluctuations in calcium. This stimulus is a signal that is detected through the calcium sensing receptor (CaSR), which modulates chemotactic and proliferative G protein-dependent signaling pathways. The objective of the present work is to evaluate the roles of extracellular calcium ([Ca(2+)]o) and the CaSR in osteoinduction. Rat bone marrow mesenchymal stromal cells (rBMSCs) were stimulated with 10mM of Ca(2+). Several experiments were conducted to demonstrate the effect of [Ca(2+)]o on chemotaxis, proliferation and differentiation on the osteoblastic lineage. It was found that [Ca(2+)]o induces rBMSCs to migrate and proliferate in a concentration-dependent manner. Real-time polymerase chain reaction and immunofluorescence also revealed that 10mM Ca(2+) stimulates overexpression of osteogenic markers in rBMSCs, including alkaline phosphatase (ALP), bone sialoprotein, collagen Ia1 and osteocalcin. Functional assays determining ALP activity and mineralization tests both corroborate the increased expression of these markers in rBMSCs stimulated with Ca(2+). Moreover, CaSR blockage inhibited the cellular response to stimulation with high concentrations of [Ca(2+)]o, revealing that the CaSR is a key modulator of these cellular responses. PMID:24525034

  2. Effects of spermine on mitochondrial Ca2+ transport and the ranges of extramitochondrial Ca2+ to which the matrix Ca2+-sensitive dehydrogenases respond.

    PubMed Central

    McCormack, J G

    1989-01-01

    1. Spermine has previously been reported to be an activator of mitochondrial Ca2+ uptake [Nicchitta & Williamson (1984) J. Biol. Chem. 259, 12978-12983]. This is confirmed in the present studies on rat heart, liver and kidney mitochondria by using the activities of the Ca2+-sensitive intramitochondrial dehydrogenases (pyruvate, NAD+-isocitrate and 2-oxoglutarate dehydrogenases) as probes for matrix Ca2+, and also, for the heart mitochondria, by using entrapped fura-2. 2. As also found previously [Damuni, Humphreys & Reed (1984) Biochem. Biophys. Res. Commun. 124, 95-99], spermine activated extracted pyruvate dehydrogenase phosphate phosphatase. However, it was found to have no effects at all on the extracted NAD+-isocitrate or 2-oxoglutarate dehydrogenases. It also had no effects on activities of the enzymes in mitochondria incubated in the absence of Ca2+, or on the Ca2+-sensitivity of the enzymes in uncoupled mitochondria. 3. Spermine clearly activated 45Ca uptake by coupled mitochondria, but had no effect on Ca2+ egress from mitochondria previously loaded with 45Ca. 4. Spermine (with effective Km values of around 0.2-0.4 mM) caused an approx. 2-3-fold decrease in the effective ranges of extramitochondrial Ca2+ in the activation of the Ca2+-sensitive matrix enzymes in coupled mitochondria from all of the tissues. The effects of spermine appeared to be largely independent of the other effectors of mitochondrial Ca2+ transport, such as Mg2+ (inhibitor of uptake) and Na+ (promoter of egrees). 5. In the most physiological circumstance, coupled mitochondria incubated with Na+ and Mg2+, the presence of saturating spermine (2 mM) resulted in an effective extramitochondrial Ca2+ range for matrix enzyme activation of from about 30-50 nM up to about 800-1200 nM, with half-maximal effects around 250-400 nM-Ca2+. The implications of these findings for the regulation of matrix and extramitochondrial Ca2+ are discussed. PMID:2604711

  3. IMPLEMENTATION OF AN URBAN CANOPY PARAMETERIZATION IN MM5

    EPA Science Inventory

    The Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model (MM5) (Grell et al. 1994) has been modified to include an urban canopy parameterization (UCP) for fine-scale urban simulations (~1-km horizontal grid spacing). The UCP accounts for drag ...

  4. Security architecture of the M&M mobile agent framework

    NASA Astrophysics Data System (ADS)

    Marques, Paulo J.; Santos, Nuno F.; Silva, Luis; Silva, Joao G.

    2001-07-01

    In the Mobile Agent programming model, small threads of execution migrate from machine to machine, performing their operations locally. For being able to deploy such a model into real world applications, security is a vital concern. In the M&M project we have developed a system that departures from the traditional platform-based execution model for mobile agents. In M&M there are no agent platforms. Instead there is a component framework that allows the applications to become able of sending and receiving agents by themselves in a straightforward manner. In this paper we examine the security mechanisms available in M&M, and how integration with existing applications is done. One difficult aspect of this work is that all the features must work with the security mechanisms that already exist on the applications. This is so because the components are integrated from within into the applications, which already have security mechanisms in place. Currently, M&M provides features like fine-grain security permissions, encryption of agents and data, certificate distribution using LDAP and cryptographic primitives for agents. For validating the approach and solutions found, we have integrated the framework into several off-the-shelf web servers, having the security mechanisms running, with no problems.

  5. Guide to Free-Loan Sports Films (16mm).

    ERIC Educational Resources Information Center

    1974

    This catalog provides information on free 16 mm films dealing with a wide variety of individual and team sports, such as football, golf, water sports, snow sports, racing, and baseball, as well as on general sports competition and safety. Unless otherwise noted, the films are in color and with sound. Titles are listed alphabetically under their…

  6. Guide to Films (16 mm) About Negroes. First Edition.

    ERIC Educational Resources Information Center

    1970

    Over 740 films (16 mm.) concerning the lives, culture, history, and problems of Black people in the United States and in Africa are listed alphabetically by title in this guide. Each entry includes the running time, a synopsis of the film's content, and a source code and tells whether the film is in black-and-white or in color. The guide includes…

  7. Herschel FIR Spectroscopic Observations of L1448-MM

    NASA Astrophysics Data System (ADS)

    Lee, Jinhee; Lee, J.; DIGIT Team

    2012-01-01

    We present the FIR (continuum and line) maps and spectra of L1448-MM at 55 to 210 micron observed with the range scan mode of PACS on the Herschel Space Observatory, as part of the DIGIT key program. L1448-MM was previously known as an embedded Class 0 and prominent outflow source, and a secondary YSO was claimed by the Spitzer images and confirmed by submm interferometric observations. The PACS detected various CO, OH, H2O, and OI lines. The PACS line and continuum maps show that the emission at shorter wavelengths peaks at the central spatial pixel (the primary YSO position) although the line emission of low energy levels distributes along the outflow direction. According to our excitation analysis, the CO gas has two temperature components (warm and hot) that are tentatively attributed to PDR and shock, respectively. However, the H2O gas with the rotational temperature of 200 K seems to trace the shock. Interestingly, the relative strength of OH transitions suggests the IR pumping process dominates in L1448-MM. The gas along the outflow cavities in L1448-MM seems to be heated mainly by shock and UV photons, and relative line luminosities indicate that H2O and CO are the main coolants of this gas, although cooling by OI and OH cannot be ignored.

  8. RF and mm-Wave Photonics at Sandia National Laboratories

    SciTech Connect

    Vawter, G.A.; Sullivan, C.

    1999-07-08

    RF and mm-wave photonic devices and circuits have been developed at Sandia National Laboratories for applications ranging from RF optical data links to optical generation of mm-wave frequencies. This talk will explore recent high-speed photonics technology developments at Sandia including: (1) A monolithic optical integrated circuit for all-optical generation of mm-waves. Using integrated mode-locked diode lasers, amplifiers, and detectors, frequencies between 30 GHz and 90 GHz are generated by a single monolithic (Al,Ga)As optical circuit less than 2mm in its largest dimension. (2) Development of polarization-maintaining, low-insertion-loss, low v-pi, Mach-Zehnder interferometer (MZI) modulators with DC-to-potentially-K-band modulation bandwidth. New low-loss polarization-maintaining waveguide designs using binary alloys have been shown to reduce polarization crosstalk in undoped (Al,Ga)As waveguides, yielding high extinction ratio (>40dB) and low on-chip loss (<6dB) in Mach-Zehnder interferometers. RF drive voltage is reduced through use of 45rnrn-active length devices with modulator sensitivity, v-pi, less than 3V.

  9. Guide to Films (16 mm) About Ecology, Adaptation and Pollution.

    ERIC Educational Resources Information Center

    1971

    Synopses of 350 films (16 mm.) on ecology, adaptation of plants and animals to their environment, and environmental pollution are listed alphabetically by title in this guide. It specifies whether the film is black-and-white or color, its running time, and its source. An abbreviated subject index and a directory of sources are also provided. The…

  10. Index to 8mm Motion Cartridges. Second Edition.

    ERIC Educational Resources Information Center

    University of Southern California, Los Angeles. National Information Center for Educational Media.

    This index to 8mm motion cartridges contains almost 10,000 entries, arranged alphabetically both by individual title and by series title in the main section of the book. Individual title entries include title with subtitle, size and physical description, length of film, stock or color code, description of contents, series title reference when…

  11. Advisory List of Instructional Media--16MM Films.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Public Instruction, Raleigh. Div. of Educational Media.

    These two advisory lists include information on 16mm films appropriate for the K-12 instructional program. In both bibliographies films are listed in the following categories: communication skills; guidance; health, physical education, safety, and sports; science; and social studies. The list for the 1982-1983 school year also includes categories…

  12. Operation and Maintenance of the 16mm Sound Film Projector.

    ERIC Educational Resources Information Center

    Rampino, Tony; Schexnaydre, Linda

    This manual presents information in seven sections: (1) parts of a 16mm film projector--film transport, threading, control, film projection, and sound system, and film projection correction devices, (2) threading procedures, (3) projection screens, (4) typical operating problems, (5) minor maintenance and repair techniques, (6) hints for the film…

  13. Routes of Ca2+ Shuttling during Ca2+ Oscillations

    PubMed Central

    Pecze, László; Blum, Walter; Schwaller, Beat

    2015-01-01

    In some cell types, Ca2+ oscillations are strictly dependent on Ca2+ influx across the plasma membrane, whereas in others, oscillations also persist in the absence of Ca2+ influx. We observed that, in primary mesothelial cells, the plasmalemmal Ca2+ influx played a pivotal role. However, when the Ca2+ transport across the plasma membrane by the “lanthanum insulation method” was blocked prior to the induction of the serum-induced Ca2+ oscillations, mitochondrial Ca2+ transport was found to be able to substitute for the plasmalemmal Ca2+ exchange function, thus rendering the oscillations independent of extracellular Ca2+. However, in a physiological situation, the Ca2+-buffering capacity of mitochondria was found not to be essential for Ca2+ oscillations. Moreover, brief spontaneous Ca2+ changes were observed in the mitochondrial Ca2+ concentration without apparent changes in the cytosolic Ca2+ concentration, indicating the presence of a mitochondrial autonomous Ca2+ signaling mechanism. In the presence of calretinin, a Ca2+-buffering protein, the amplitude of cytosolic spikes during oscillations was decreased, and the amount of Ca2+ ions taken up by mitochondria was reduced. Thus, the increased calretinin expression observed in mesothelioma cells and in certain colon cancer might be correlated to the increased resistance of these tumor cells to proapoptotic/pronecrotic signals. We identified and characterized (experimentally and by modeling) three Ca2+ shuttling pathways in primary mesothelial cells during Ca2+ oscillations: Ca2+ shuttled between (i) the endoplasmic reticulum (ER) and mitochondria, (ii) the ER and the extracellular space, and (iii) the ER and cytoplasmic Ca2+ buffers. PMID:26396196

  14. A kinetic investigation of the effects of adrenaline on 45Ca2+ exchange in isolated hepatocytes at different Ca2+ concentrations, at 20 degrees C and in the presence of inhibitors of mitochondrial Ca2+ transport.

    PubMed Central

    Parker, J C; Barritt, G J; Wadsworth, J C

    1983-01-01

    The effects of adrenaline on 45Ca2+-exchange curves for isolated hepatocytes incubated under various steady-state conditions were investigated. Kinetic analysis showed that the simplest compartment configuration consistent with each set of data was a series configuration of a three-compartment closed system comprising compartment 1 (C1), the extracellular medium, and two kinetically distinct compartments of cellular exchangeable Ca2+, C2 and C3 (C1 = C2 = C3). Subcellular fractionation of hepatocytes labelled with 45Ca2+ at 0.1 mM-Ca2+ indicated that C3 includes exchangeable Ca2+ in the mitochondria and endoplasmic reticulum. The following results were obtained from experiments conducted at 37 degrees C at five different extracellular Ca2+ concentrations. For both untreated and adrenaline-treated cells, plots of the flux from C1 to C2 as a function of the extracellular Ca2+ concentration were best described by straight lines consistent with Ca2+ influx across the plasma membrane being a diffusion process. Adrenaline increased the value of the permeability constant for Ca2+ influx by 40%. For untreated cells, plots of the flux between C2 and C3 as a function of the concentrations of Ca2+ in these compartments approached a plateau at high Ca2+ concentrations. Adrenaline caused a 3-fold increase in the concentration of Ca2+ that gives half-maximal rate of Ca2+ transport from C2 to C3. At 1.3 mM extracellular Ca2+, a decrease in incubation temperature from 37 degrees C to 20 degrees C decreased the quantity of Ca2+ in C3 and the flux and fractional transfer rates for the transport of Ca2+ between C2 and C3. At 20 degrees C adrenaline increased the quantity of Ca2+ in C3 and the fractional transfer rates for the transfer of Ca2+ from C1 to C2, and from C2 to C3. At 37 degrees C and 2.4 mM extracellular Ca2+, antimycin A plus oligomycin decreased the quantity of Ca2+ in C3 and increased the fractional transfer rate for the transport of Ca2+ from C3 to C2. In the presence

  15. [Effect of vanadate on Ca++-activation in skeletal muscle].

    PubMed

    Son'kin, B Ia; Bukatina, A E

    1983-01-01

    Vanadate (0.1 mM) reduces tension of glycerinated rabbit psoas muscle fibers, shifts tension--pCa curve to lower pCa, increases the rate constant of delayed tension development and changes dependence of this rate constant on the level of Ca2+-activation. Vanadate influence stops the increase of the rate constant with the rise of Ca++-activated tension. Since actin-myosin-ADP complex is dissociated by vanadate, the muscle performance at low activation levels is supposed to be conditioned largely by the cross-bridges interacting with actin of the actin blocks switched on by myosin-ADP. Kinetics of such cross-bridges differs from that of the cross bridges interacting with actin activated by Ca++ binding to troponin C. PMID:6556917

  16. Mineralogic Model (MM3.0) Analysis Model Report

    SciTech Connect

    C. Lum

    2002-02-12

    The purpose of this report is to document the Mineralogic Model (MM), Version 3.0 (MM3.0) with regard to data input, modeling methods, assumptions, uncertainties, limitations and validation of the model results, qualification status of the model, and the differences between Version 3.0 and previous versions. A three-dimensional (3-D) Mineralogic Model was developed for Yucca Mountain to support the analyses of hydrologic properties, radionuclide transport, mineral health hazards, repository performance, and repository design. Version 3.0 of the MM was developed from mineralogic data obtained from borehole samples. It consists of matrix mineral abundances as a function of x (easting), y (northing), and z (elevation), referenced to the stratigraphic framework defined in Version 3.1 of the Geologic Framework Model (GFM). The MM was developed specifically for incorporation into the 3-D Integrated Site Model (ISM). The MM enables project personnel to obtain calculated mineral abundances at any position, within any region, or within any stratigraphic unit in the model area. The significance of the MM for key aspects of site characterization and performance assessment is explained in the following subsections. This work was conducted in accordance with the Development Plan for the MM (CRWMS M&O 2000). The planning document for this Rev. 00, ICN 02 of this AMR is Technical Work Plan, TWP-NBS-GS-000003, Technical Work Plan for the Integrated Site Model, Process Model Report, Revision 01 (CRWMS M&O 2000). The purpose of this ICN is to record changes in the classification of input status by the resolution of the use of TBV software and data in this report. Constraints and limitations of the MM are discussed in the appropriate sections that follow. The MM is one component of the ISM, which has been developed to provide a consistent volumetric portrayal of the rock layers, rock properties, and mineralogy of the Yucca Mountain site. The ISM consists of three components: (1

  17. Review of Tm and Ho Materials; Spectroscopy and Lasers

    NASA Technical Reports Server (NTRS)

    Walsh, Brian M.

    2008-01-01

    A review of Tm and Ho materials is presented, covering some fundamental aspects on the spectroscopy and laser dynamics in both single and co-doped systems. Following an introduction to 2- m lasers, applications and historical development, the physics of quasi-four level lasers, energy transfer and modeling are discussed in some detail. Recent developments in using Tm lasers to pump Ho lasers are discussed, and seen to offer some advantages over conventional Tm:Ho lasers. This article is not intended as a complete review, but as a primer for introducing concepts and a resource for further study.

  18. MM 55266 and MM 55268, glycopeptide antibiotics produced by a new strain of Amycolatopsis. Isolation, purification and structure determination.

    PubMed

    Box, S J; Coates, N J; Davis, C J; Gilpin, M L; Houge-Frydrych, C S; Milner, P H

    1991-08-01

    Two novel glycopeptide antibiotics MM 55266 and MM 55268 containing fatty acid acyl functions, and of molecular formula C86H89N8O35Cl5 and C87H91N8O35Cl5, respectively, have been isolated and identified from a complex produced by Amycolatopsis sp. NCIB 40089. Fermentation conditions for their production, and methods for their isolation are described. Structures have been deduced by use of COSY and NOE NMR techniques and supported by chemical degradation studies. Both glycopeptides possessed good antibacterial activity against Gram-positive organisms. PMID:1917694

  19. Charpy impact test results on five materials and NIST verification specimens using instrumented 2-mm and 8-mm strikers

    SciTech Connect

    Nanstad, R.K.; Sokolov, M.A.

    1995-04-01

    The Heavy-Section Steel Irradiation Program at Oak Ridge National Laboratory is involved in two cooperative projects, with international participants, both of which involve Charpy V-notch impact tests with instrumented strikers of 2mm and 8mm radii. Two heats of A 533 grade B class I pressure vessel steel and a low upper-shelf (LUS) submerged-arc (SA) weld were tested on the same Charpy machine, while one heat of a Russian Cr-Mo-V forging steel and a high upper-shelf (HUS) SA weld were tested on two different machines. The number of replicate tests at any one temperature ranged from 2 to 46 specimens. Prior to testing with each striker, verification specimens at the low, high, and super high energy levels from the National Institute of Standards and Technology (NIST) were tested. In the two series of verification tests, the tests with the 2mm striker met the requirements at the low and high energy levels but not at the super high energy. For one plate, the 2mm striker showed somewhat higher average absorbed energies than those for the 8-mm striker at all three test temperatures. For the second plate and the LUS weld, however, the 2mm striker showed somewhat lower energies at both test temperatures. For the Russian forging steel and the HUS weld, tests were conducted over a range of temperatures with tests at one laboratory using the 8mm striker and tests at a second laboratory using the 2mm striker. Lateral expansion was measured for all specimens and the results are compared with the absorbed energy results. The overall results showed generally good agreement (within one standard deviation) in energy measurements by the two strikers. Load-time traces from the instrumented strikers were also compared and used to estimate shear fracture percentage. Four different formulas from the European Structural Integrity Society draft standard for instrumented Charpy test are compared and a new formula is proposed for estimation of percent shear from the force-time trace.

  20. Towards Performance Portability with GungHo

    NASA Astrophysics Data System (ADS)

    Ford, Rupert; Glover, Matthew; Ham, David; Hobson, Mike; Maynard, Chris; Mitchell, Lawrence; Mullerworth, Steve; Pickles, Stephen; Rezny, Mike; Riley, Graham; Wood, Nigel; Ashworth, Mike

    2014-05-01

    The Met Office's numerical weather prediction and climate model code, the Unified Model (UM), is almost 25 years old. Up to the present day the UM has been able to be run efficiently on many of the worlds most powerful computers, helping to keep the Met Office at the forefront of climate prediction and weather forecasting. However, with performance increases from each new generation of computers now being primarily provided by an increase in the amount of parallelism rather than an increase in the clock-speed of the processors themselves, running higher resolutions of the UM now faces the double challenge of code scalability and numerical accuracy. The UM's atmospheric dynamical core makes use of a finite-difference scheme on a regular latitude-longitude grid. The regular latitude-longitude mesh results in an increasingly disparate grid resolution as the mesh resolution increases due to lines of longitude converging at the poles. For example, a 10km resolution at mid-latitudes would result in a 12m resolution at the poles. The difference in resolution leads to increased communication at the poles and load balance issues which are known to impair scalability; it also leads to issues with numerical accuracy and smaller time-steps due to the difference in scale. To address this problem the Met Office, NERC and STFC initiated the GungHo project. The primary aim of this project is to deliver a scalable, numerically accurate dynamical core. This dynamical core is scheduled to become operational around the year 2022. The project is currently investigating the use of quasi-uniform meshes, such as triangular, icosahedral and cubed-sphere meshes, using finite element methods. The associated GungHo software infrastructure is being developed to support multiple meshes and element types thus allowing for future model development. GungHo is also proposing a novel separation of concerns for the software implementation of the dynamical core. This approach distinguishes between

  1. 1.88 Micrometers InGaAsP Pumped, Room Temperature Ho: LuAG Laser

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P.; Amzajerdian, Farzin; Reichle, Donald J.; Busch, George; Leisher, Paul

    2009-01-01

    A room temperature, directly diode pumped Ho:LuAG laser oscillated for the first time. Direct pumping of the Ho upper laser manifold maximizes efficiency, minimizes heating, and eliminates Ho:Tm energy sharing. Design and performance are presented.

  2. Difficulty in the intravesical morcellation procedure for leiomyoma of the prostate enucleated by HoLEP.

    PubMed

    Shinojima, Toshiaki; Yoshimine, Shunsuke

    2013-01-01

    Leiomyoma of prostate are rare benign neoplasms that are usually diagnosed incidentally through postoperative pathological examination. A 70-year-old man is presented with severe symptoms of lower urinary tract obstruction. Although a digital rectal examination and the prostate-specific antigen level did not suggest malignancy, transrectal ultrasonography showed an unusual homogenous echoic mass measuring 45×37 mm in size in the prostate. A needle biopsy was performed and pathological diagnosis was prostatic leiomyoma. Holmium laser enucleation of prostate (HoLEP) was chosen and performed to resect the tumour. Although the enucleation step presented no problems, the morcellation procedure using a conventional transurethral mechanical morcellator was very difficult owing to the firmness of the tissue. By using a bipolar erectrosurgical loop, fragmentation and removal of tissue was accomplished. This is the first case reported of these rare neoplasms in which HoLEP was offered as a less invasive surgical approach. We emphasise the firmness of the leiomyomatous tissue, which would lead to morcellation failure. PMID:23966460

  3. Difficulty in the intravesical morcellation procedure for leiomyoma of the prostate enucleated by HoLEP

    PubMed Central

    Shinojima, Toshiaki; Yoshimine, Shunsuke

    2013-01-01

    Leiomyoma of prostate are rare benign neoplasms that are usually diagnosed incidentally through postoperative pathological examination. A 70-year-old man is presented with severe symptoms of lower urinary tract obstruction. Although a digital rectal examination and the prostate-specific antigen level did not suggest malignancy, transrectal ultrasonography showed an unusual homogenous echoic mass measuring 45×37 mm in size in the prostate. A needle biopsy was performed and pathological diagnosis was prostatic leiomyoma. Holmium laser enucleation of prostate (HoLEP) was chosen and performed to resect the tumour. Although the enucleation step presented no problems, the morcellation procedure using a conventional transurethral mechanical morcellator was very difficult owing to the firmness of the tissue. By using a bipolar erectrosurgical loop, fragmentation and removal of tissue was accomplished. This is the first case reported of these rare neoplasms in which HoLEP was offered as a less invasive surgical approach. We emphasise the firmness of the leiomyomatous tissue, which would lead to morcellation failure. PMID:23966460

  4. Novice performance of ultrasound-guided needle advancement: standard 38-mm transducer vs 25-mm hockey stick transducer.

    PubMed

    Davies, T; Townsley, P; Jlala, H; Dowling, M; Bedforth, N; Hardman, J G; McCahon, R A

    2012-08-01

    The optimal method to develop expertise in ultrasound-guided regional anaesthesia is unknown. Studies of laryngoscopic expertise in novices demonstrate that the choice of laryngoscope affects performance. In this study, we aimed to compare the effect of two different linear array transducers (38-mm standard vs 25-mm hockey stick) on novice performance of ultrasound-guided needle advancement. Following randomisation, participants watched a video model of expert performance of ultrasound-guided needle advancement. Recruits performed the modelled task on a turkey breast model. The median (IQR [range]) composite error score was statistically significantly larger for participants in the hockey stick transducer group compared with the standard transducer group; 10.0 (7.3-14.3 [2.5-29.0]) vs 7.5 (4.5-10.0 [2.0-28.0]) respectively, (p = 0.01). This study has demonstrated that performance of ultrasound-guided needle advancement by novice operators after simple video instruction is better (as assessed using a composite error score) with a standard 38-mm transducer than with a 25-mm hockey stick transducer. PMID:22506607

  5. MmTX1 and MmTX2 from coral snake venom potently modulate GABAA receptor activity.

    PubMed

    Rosso, Jean-Pierre; Schwarz, Jürgen R; Diaz-Bustamante, Marcelo; Céard, Brigitte; Gutiérrez, José M; Kneussel, Matthias; Pongs, Olaf; Bosmans, Frank; Bougis, Pierre E

    2015-02-24

    GABAA receptors shape synaptic transmission by modulating Cl(-) conductance across the cell membrane. Remarkably, animal toxins that specifically target GABAA receptors have not been identified. Here, we report the discovery of micrurotoxin1 (MmTX1) and MmTX2, two toxins present in Costa Rican coral snake venom that tightly bind to GABAA receptors at subnanomolar concentrations. Studies with recombinant and synthetic toxin variants on hippocampal neurons and cells expressing common receptor compositions suggest that MmTX1 and MmTX2 allosterically increase GABAA receptor susceptibility to agonist, thereby potentiating receptor opening as well as desensitization, possibly by interacting with the α(+)/β(-) interface. Moreover, hippocampal neuron excitability measurements reveal toxin-induced transitory network inhibition, followed by an increase in spontaneous activity. In concert, toxin injections into mouse brain result in reduced basal activity between intense seizures. Altogether, we characterized two animal toxins that enhance GABAA receptor sensitivity to agonist, thereby establishing a previously unidentified class of tools to study this receptor family. PMID:25675485

  6. MmTX1 and MmTX2 from coral snake venom potently modulate GABAA receptor activity

    PubMed Central

    Rosso, Jean-Pierre; Schwarz, Jürgen R.; Diaz-Bustamante, Marcelo; Céard, Brigitte; Gutiérrez, José M.; Kneussel, Matthias; Pongs, Olaf; Bosmans, Frank; Bougis, Pierre E.

    2015-01-01

    GABAA receptors shape synaptic transmission by modulating Cl− conductance across the cell membrane. Remarkably, animal toxins that specifically target GABAA receptors have not been identified. Here, we report the discovery of micrurotoxin1 (MmTX1) and MmTX2, two toxins present in Costa Rican coral snake venom that tightly bind to GABAA receptors at subnanomolar concentrations. Studies with recombinant and synthetic toxin variants on hippocampal neurons and cells expressing common receptor compositions suggest that MmTX1 and MmTX2 allosterically increase GABAA receptor susceptibility to agonist, thereby potentiating receptor opening as well as desensitization, possibly by interacting with the α+/β− interface. Moreover, hippocampal neuron excitability measurements reveal toxin-induced transitory network inhibition, followed by an increase in spontaneous activity. In concert, toxin injections into mouse brain result in reduced basal activity between intense seizures. Altogether, we characterized two animal toxins that enhance GABAA receptor sensitivity to agonist, thereby establishing a previously unidentified class of tools to study this receptor family. PMID:25675485

  7. Preconditioning with low concentration NO attenuates subsequent NO-induced apoptosis in vascular smooth muscle cells via HO-1-dependent mitochondrial death pathway

    SciTech Connect

    Kwak, Hyun-Jeong; Park, Kyoung-Mi; Lee, Seahyoung; Lim, Hyun-Joung; Go, Sang-Hee; Eom, Sang-Mi; Park, Hyun-Young . E-mail: hypark65@nih.go.kr

    2006-12-01

    Nitric oxide (NO) signaling pathways are important in both the maintenance of vascular homeostasis and disease progression. Overproduction of NO has been associated with ischemia/reperfusion (I/R) injury. Growing evidences suggest that NO preconditioning has cytoprotective effects against I/R injury. However, the mechanism with which NO mediates these effects remains to be elucidated. The purpose of this study was to examine the mechanism of how NO preconditioning inhibits subsequent NO-induced apoptosis in vascular smooth muscle cells (VSMC), specifically focusing on heme oxygenase-1 (HO-1). According to our data, sodium nitroprusside (SNP) increased HO-1 expression in a concentration dependent manner. Preconditioning with low concentration SNP (0.3 mM) inhibited subsequent high concentration SNP (1.5 mM)-induced apoptosis, and this effect was reversed by the HO-1 inhibitor SnPP. Low concentration SNP-mediated protection involved p38 kinase inactivation and increased Bcl-2 expression. Furthermore, mitochondrial membrane potential was concomitantly increased with decreased expressions of Bax, Apaf-1, and activity of caspase-3, which was reversed by SnPP treatment. Our results show that low concentration SNP preconditioning suppresses subsequent high concentration SNP-induced apoptosis by inhibiting p38 kinase and mitochondrial death pathway via HO-1-dependent mechanisms in VSMC.

  8. Na-Ca exchange in vascular smooth muscle sarcolemmal vesicles is voltage sensitive and inhibitable by quinidine and diltiazem

    SciTech Connect

    Kahn, A.M.; Allen, J.C.

    1986-03-05

    These studies were performed to characterize Na-Ca exchange in a sarcolemmal enriched vesicle fraction, obtained by Mg aggregation and differential centrifugation of homogenized bovine superior mesenteric artery (SMA). To avoid the effects of Ca or Na diffusion potentials on the translocation of the counter ion, the transport of /sup 45/Ca or /sup 22/Na was measured in vesicles which were short-circuited by presetting K/sub in/ = k/sub out/ in the presence of the K ionophore, valinomycin. The uptake of 0.1 mM Ca/sub out/ was stimulated 30% by 150 mM Na/sub in/ versus N-methylglucamine/sub in/, in a control cation. The uptake of ImM Na/sub out/ was stimulated 61% by 10 mM Ca/sub in/ versus Mn/sub in/. The efflux of ImM Na/sub in/ was stimulated 57% by 10 mM Ca/sub out/ versus Mn/sub out/. Thus, these vesicles mediate Na/Ca exchange. The one sec Na gradient-dependent uptake of 0.1 mM Ca/sub out/ was .08 nmol/mg under short-circuited conditions. When the membrane potential was rendered inside positive by an inwardly directed K gradient plus valinomycin, Na gradient-dependent Ca uptake increased to 0.17 nmol/mg. The Na gradient-dependent uptake of 0.1 mM Ca/sub out/ was inhibited 12, 6, 82, and 70% by (in mM) 5 choline, 3 amiloride, 5 quinidine, and 5 diltiazem, respectively. It is concluded that Na-Ca exchange in the sarcolemmal of bovine SMA is voltage sensitive, and inhibitable by quinidine and diltiazem. Depolarization stimulated Ca influx in vascular smooth muscle cells may occur, in part, via Na-Ca exchange.

  9. Materials Data on CaP4(HO6)2 (SG:14) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-10-02

    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

  10. Materials Data on CaNiAsHO5 (SG:19) by Materials Project

    SciTech Connect

    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

  11. Materials Data on CaHoMn2O6 (SG:31) by Materials Project

    SciTech Connect

    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

  12. Materials Data on Ca3(HO3)2 (SG:12) by Materials Project

    SciTech Connect

    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

  13. Materials Data on Ca3Al2(HO)12 (SG:230) by Materials Project

    SciTech Connect

    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

  14. Materials Data on NaCa2Si3HO9 (SG:2) by Materials Project

    SciTech Connect

    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

  15. Materials Data on CaP2(HO)4 (SG:15) by Materials Project

    SciTech Connect

    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

  16. Materials Data on CaZnAsHO5 (SG:19) by Materials Project

    SciTech Connect

    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

  17. Materials Data on Ca2Al3Si3HO13 (SG:62) by Materials Project

    SciTech Connect

    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

  18. Materials Data on Ca(HO)2 (SG:164) by Materials Project

    SciTech Connect

    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

  19. Materials Data on CaCoAsHO5 (SG:19) by Materials Project

    SciTech Connect

    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

  20. Materials Data on Ca5P3HO13 (SG:173) by Materials Project

    SciTech Connect

    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

  1. An efficient continuous-wave and Q-switched single-pass two-stage Ho:YLF MOPA system

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, Jacek; Jabczynski, Jan Karol; Zendzian, Waldemar

    2015-04-01

    We report on the efficient operation of an Ho:YLF laser single-pass in-band pumped by a Tm-doped fiber laser. The research in a continuous-wave (CW) operation in an oscillator scheme was done for a crystal of 0.5 at% Ho dopant concentration and the length of 30 mm for the output coupler transmittances of TOC=10%, 20%, 30% and 40%. At room temperature, for the output coupling transmission of 20%, the maximum CW output power of 24.5 W for 82.5 W of incident pump power, corresponding to the slope efficiency of 35.4% and optical-to-optical conversion efficiency of 29.7% was achieved. The highest slope efficiency of 81.6% with respect to absorbed pump power was obtained. Carrying out the measurements of the laser spectrum, for the out-coupling transmittance of TOC=30%, we observed a very short time wavelength shift between 2051.5 and 2062.4 nm in an Ho:YLF laser operation. Trying to fully utilize the pump power unabsorbed by the active crystal in an oscillator stage, an amplifier system based on two additional Ho:YLF crystals was developed. For the output coupling transmission of 40% the slope efficiency increased from 31.5% in an oscillator scheme to 47.3% with respect to the incident pump power in a two-stage amplifier scheme with a beam quality parameter of M2 better than 1.1. For a Q-switched operation, for the maximum incident pump power and the pulse repetition frequency (PRF) of 1 kHz, pulse energies of 18.5 mJ with a 22 ns FWHM pulse width corresponding to 841 kW peak power in the amplifier system were recorded.

  2. Six-mm, plane-wave shock driver

    SciTech Connect

    Frank, A.M.; Chau, H.H.

    1993-06-14

    A 6-mm-diameter, plane-wave shock generation system has been developed and characterized as a laboratory bench driver for small scale experiments. The driver is based on an exploding-foil-driven slapper used either directly or to initiate an HE pellet. The slapper is driven by a low-inductance fireset with burst currents on the order of 30 kA and burst times of about 250ns, with a time-to-burst jitter under 10ns. Both the slapper impact and the detonation breakout of the pellet have been measured to be flat to within 10ns over a 6-mm diameter. Fabry-Perot velocimetry of impacts with LiF crystals were used to characterize shock pressures and durations. Attenuator plates and flyers driven by the HE were also measured, which provided a variety of available pulse shapes and data for modeling efforts.

  3. A 300-nm compact mm-wave linac FEL design

    SciTech Connect

    Nassiri, A.; Kustom, R.L.; Kang, Y.W.

    1995-12-31

    Microfabrication technology offers an alternative method for fabricating precision, miniature-size components suitable for use in accelerator physics and commercial applications. The original R&D work at Argonne, in collaboration with the University of Illinois at Chicago, has produced encouraging results in the area of rf accelerating structure design, optical and x-ray masks production, deep x-ray lithography (LIGA exposures), and precision structural alignments. In this paper we will present a design study for a compact single pass mm-linac FEL to produce short wavelength radiation. This system will consists of a photocathode rf gun operated at 30 GHz, a 50-MeV superconducting constant gradient structure operated at 60 GHz, and a microundulator with 1-mm period. Initial experimental results on a scale model rf gun and microundulator will be presented.

  4. A 10-mm MR-Conditional Unidirectional Pneumatic Stepper Motor.

    PubMed

    Chen, Yue; Mershon, Christopher D; Tse, Zion Tsz Ho

    2015-04-01

    Magnetic resonance (MR) conditional robotic devices facilitate accurate interventional procedures under MR imaging (MRI) guidance. For this purpose, a compact (10-mm diameter) MR-conditional stepper motor is presented. The device features seven key components, which contribute to a dense and easy to fabricate design. Alternating bursts of pressurized air and vacuum can drive the motor in 60° per step to achieve a maximum torque of 2.4 mNm. The relationship between torque and angular speed was investigated to demonstrate motor performance under different loading conditions. The stepper motor was tested in a GE 3T MRI scanner to verify its MR-compatibility. A maximum artifact width of 3 mm was measured in MRI images and a maximum signal-to-noise ratio reduction of 2.49% was recorded. PMID:25419104

  5. A 10-mm MR-Conditional Unidirectional Pneumatic Stepper Motor

    PubMed Central

    Chen, Yue; Mershon, Christopher D.; Tse, Zion Tsz Ho

    2014-01-01

    Magnetic resonance (MR) conditional robotic devices facilitate accurate interventional procedures under MR imaging (MRI) guidance. For this purpose, a compact (10-mm diameter) MR-conditional stepper motor is presented. The device features seven key components, which contribute to a dense and easy to fabricate design. Alternating bursts of pressurized air and vacuum can drive the motor in 60° per step to achieve a maximum torque of 2.4 mNm. The relationship between torque and angular speed was investigated to demonstrate motor performance under different loading conditions. The stepper motor was tested in a GE 3T MRI scanner to verify its MR-compatibility. A maximum artifact width of 3 mm was measured in MRI images and a maximum signal-to-noise ratio reduction of 2.49% was recorded. PMID:25419104

  6. Magnetic ordering in Ho2Fe2Si2C

    NASA Astrophysics Data System (ADS)

    Susilo, R. A.; Cadogan, J. M.; Cobas, R.; Hutchison, W. D.; Avdeev, M.; Campbell, S. J.

    2015-05-01

    We have used neutron diffraction and 57Fe Mössbauer spectroscopy, complemented by magnetisation and specific heat measurements, to examine the magnetic ordering of Ho2Fe2Si2C. We have established that Ho2Fe2Si2C orders antiferromagnetically below TN = 16(1) K with a magnetic structure involving ordering of the Ho sublattice along the b-axis with a propagation vector k =[0 0 1/2 ] . 57Fe Mössbauer spectra collected below TN show no evidence of a magnetic splitting, demonstrating the absence of long range magnetic ordering of the Fe sublattice. A small line broadening is observed in the 57Fe spectra below TN, which is due to a transferred hyperfine field—estimated to be around 0.3 T at 10 K—from the Ho sublattice.

  7. An important role for the Na+-Ca2+ exchanger in the decrease in cytosolic Ca2+ concentration induced by isoprenaline in the porcine coronary artery.

    PubMed

    Yamanaka, Jun; Nishimura, Junji; Hirano, Katsuya; Kanaide, Hideo

    2003-06-01

    The role of the Na+-Ca2+ exchanger (NCX) in the mechanism of the isoprenaline (Iso)-induced vasorelaxation was investigated by simultaneously monitoring the intracellular Ca2+ concentration ([Ca2+]i) and tension of fura-2-loaded medial strips of porcine coronary arteries. Normal physiological salt solution (PSS) contained 137.3 mM Na+ and 5.9 mM K+. During the sustained phase of contraction, Iso induced only a transient decrease in [Ca2+]i when contraction was induced by depolarization with 118 mM K+ solution containing 25.2 mM Na+. When contraction was induced with 30 mM K+ in PSS containing 113.2 mM Na+, Iso induced a sustained decrease in [Ca2+]i, whereas in contractions induced by 30 mM K+ in a low Na+ (25.2 mM Na+) PSS, Iso transiently decreased [Ca2+]i. Replacement of Ca2+ with Ba2+ (which cannot be extruded by the Ca2+ pumps but can be extruded through the NCX) resulted in decreased [Ba2+]i induced by Iso in normal but not in low Na+ PSS. On the other hand, Iso induced a sustained decrease in [Ca2+]i when strips were pre-contracted by U46619, a thromboxane A2 analogue, in PSS. Various types of K+ channel blockers (iberiotoxin, 4-aminopyridine, apamin or glibenclamide) or combinations of these blockers failed to completely inhibit the Iso-induced decreases in [Ca2+]i and tension. However, Iso-induced sustained decreases in [Ca2+]i during the contraction induced by U46619 were greatly inhibited in a low Na+ PSS. The Iso-induced decrease in tension during contraction by U46619 was greatly inhibited by 2',4'-dichlorobenzamil, a forward- and reverse-mode NCX inhibitor, but not by ouabain, a selective inhibitor of Na+,K+-ATPase. These results indicate that the NCX is involved in the Iso-induced reduction of [Ca2+]i and tension of the porcine coronary arterial smooth muscle. PMID:12740420

  8. Cytoplasmic Na+-dependent modulation of mitochondrial Ca2+ via electrogenic mitochondrial Na+–Ca2+ exchange

    PubMed Central

    Kim, Bongju; Matsuoka, Satoshi

    2008-01-01

    To clarify the role of mitochondrial Na+–Ca2+ exchange (NCXmito) in regulating mitochondrial Ca2+ (Ca2+mito) concentration at intact and depolarized mitochondrial membrane potential (ΔΨmito), we measured Ca2+mito and ΔΨmito using fluorescence probes Rhod-2 and TMRE, respectively, in the permeabilized rat ventricular cells. Applying 300 nm cytoplasmic Ca2+ (Ca2+c) increased Ca2+mito and this increase was attenuated by cytoplasmic Na+ (Na+c) with an IC50 of 2.4 mm. To the contrary, when ΔΨmito was depolarized by FCCP, a mitochondrial uncoupler, Na+c enhanced the Ca2+c-induced increase in Ca2+mito with an EC50 of about 4 mm. This increase was not significantly affected by ruthenium red or cyclosporin A. The inhibition of NCXmito by CGP-37157 further increased Ca2+mito when ΔΨmito was intact, while it suppressed the Ca2+mito increase when ΔΨmito was depolarized, suggesting that ΔΨmito depolarization changed the exchange mode from forward to reverse. Furthermore, ΔΨmito depolarization significantly reduced the Ca2+mito decrease via forward mode, and augmented the Ca2+mito increase via reverse mode. When the respiratory chain was attenuated, the induction of the reverse mode of NCXmito hyperpolarized ΔΨmito, while ΔΨmito depolarized upon inducing the forward mode of NCXmito. Both changes in ΔΨmito were remarkably inhibited by CGP-37157. The above experimental data indicated that NCXmito is voltage dependent and electrogenic. This notion was supported theoretically by computer simulation studies with an NCXmito model constructed based on present and previous studies, presuming a consecutive and electrogenic Na+–Ca2+ exchange and a depolarization-induced increase in Na+ flux. It is concluded that Ca2+mito concentration is dynamically modulated by Na+c and ΔΨmito via electrogenic NCXmito. PMID:18218682

  9. Augmented approach to desirability function based on MM estimator

    NASA Astrophysics Data System (ADS)

    Midi, Habshah; Mustafa, Mohd Shafie; Fitrianto, Anuar

    2013-04-01

    The desirability function approach is commonly used in industry to tackle multiple response optimization problems. The shortcoming of this approach is that the variability in each predicted response is ignored. It is now evident that the actual response may fall outside the acceptable region even though the predicted response at the optimal solution has a high overall desirability score. An augmented approach to the desirability function (AADF) is put forward to rectify this problem. Nevertheless the AADF is easily affected by outliers since the AADF is constructed based on the Ordinary Least Squares (OLS) estimate which is not resistant to outliers. As an alternative, we propose a robust MM-estimator to estimate the parameters of the Response Surface Model (RSM) and incorporated the estimated parameters in the augmented approach framework. A numerical example is presented to assess the performance of the AADF-MM based method. The numerical results signify that the AADF-MM based is more efficient than the AADF-OLS based method.

  10. Projected Hybrid Orbitals: A General QM/MM Method

    PubMed Central

    2015-01-01

    A projected hybrid orbital (PHO) method was described to model the covalent boundary in a hybrid quantum mechanical and molecular mechanical (QM/MM) system. The PHO approach can be used in ab initio wave function theory and in density functional theory with any basis set without introducing system-dependent parameters. In this method, a secondary basis set on the boundary atom is introduced to formulate a set of hybrid atomic orbtials. The primary basis set on the boundary atom used for the QM subsystem is projected onto the secondary basis to yield a representation that provides a good approximation to the electron-withdrawing power of the primary basis set to balance electronic interactions between QM and MM subsystems. The PHO method has been tested on a range of molecules and properties. Comparison with results obtained from QM calculations on the entire system shows that the present PHO method is a robust and balanced QM/MM scheme that preserves the structural and electronic properties of the QM region. PMID:25317748

  11. Enhancing Paradynamics for QM/MM Sampling of Enzymatic Reactions.

    PubMed

    Lameira, Jerônimo; Kupchencko, Ilya; Warshel, Arieh

    2016-03-10

    Despite the enormous increase in computer power, it is still extremely challenging to obtain computationally converging sampling of ab initio QM/MM (QM(ai)/MM) free energy surfaces in condensed phases. The sampling problem can be significantly reduced by the use of the reference potential paradynamics (PD) approach, but even this approach still requires major computer time in studies of enzymatic reactions. To further reduce the sampling problem we developed here a new PD version where we use an empirical valence bond reference potential that has a minimum rather than a maximum at the transition state region of the target potential (this is accomplished conveniently by shifting the EVB of the product state). Hence, we can map the TS region in a more efficient way. Here, we introduce and validate the inverted EVB PD approach. The validation involves the study of the S(N)2 step of the reaction catalyzed by haloakene dehalogenase (DhlA) and the GTP hydrolysis in the RasGAP system. In addition, we have also studied the corresponding reaction in water for each of the systems described here and the reaction involving trimethylsulfonium and dimethylamine in solution. The results are encouraging and the new strategy appears to provide a powerful way of evaluating QM(ai)/MM activation free energies. PMID:26866994

  12. Feasibility studies of a compact mm-wave linac FEL

    SciTech Connect

    Nassiri, A.; Kustom, R.L.; Kang, Y.W.; Song, J.

    1995-12-31

    Short wavelength FELs impose stringent requirements on the quality of the electron beams. The key factor in obtaining a single-pass UV or x-ray FEL is the generation of small emittance electron beams with ultra-high brightness. The pioneering work at Los Alamos National Laboratory in the last decade has resulted in a dramatic improvement in the production of high electron beam brightness and small beam emittance using rf photocathode gun. The lower bound on the emittance of a 1-nC bunch without any emittance compensation is on the order of 3 {pi} mm-mrad. This is well within the emittance requirement being considered here. Although the original R&D work at Argonne, in collaboration with the University of Illinois at Chicago and University of Wisconsin-Madison, has produced encouraging results in the area of rf structure design, x-ray mask fabrication, and LIGA processing (Lithography, Electroforming, and Molding), the goal to prove feasibility has not yet been achieved. In this paper, we will present feasibility studies for a compact single-pass mm-linac FEL based on LIGA technology. This system will consist of a photocathode rf gun operated at 30 GHz, a 50-MeV superconducting constant gradient structure operated at 60 GHz, and a microundulator with 1-mm period.

  13. High Rate Proton Irradiation of 15mm Muon Drifttubes

    NASA Astrophysics Data System (ADS)

    Zibell, A.; Biebel, O.; Hertenberger, R.; Ruschke, A.; Schmitt, Ch.; Kroha, H.; Bittner, B.; Schwegler, P.; Dubbert, J.; Ott, S.

    2012-08-01

    Future LHC luminosity upgrades will significantly increase the amount of background hits from photons, neutrons 11.11d protons in the detectors of the ATLAS muon spectrometer. At the proposed LHC peak luminosity of 5\\cdot 1034(1)/(cm2s), background hit rates of more than 10(kHz)/(cm2) are expected in the innermost forward region, leading to a loss of performance of the current tracking chambers. Based on the ATLAS Monitored Drift Tube chambers, a new high rate capable drift tube detecor using tubes with a reduced diameter of 15mm was developed. To test the response to highly ionizing particles, a prototype chamber of 46 15mm drift tubes was irradiated with a 20 MeV proton beam at the tandem accelerator at the Maier-Leibnitz Laboratory, Munich. Three tubes in a planar layer were irradiated while all other tubes were used for reconstruction of cosmic muon tracks through irradiated and nonirradiated parts of the chamber. To determine the rate capability of the 15mm drifttubes we investigated the effect of the proton hit rate on pulse height, efficiency and spatial resolution of the cosmic muon signals.

  14. Passive Ca transport in human red blood cell ghosts measured with entrapped arsenazo III

    PubMed Central

    1984-01-01

    The rate of Ca influx into ghosts containing arsenazo III changes with time, being most rapid during the first 5 min after Ca is added to the outside and declining thereafter. The rate of Ca influx is a nonlinear function of extracellular Ca and plateaus as the latter is increased above 1 mM. The rate of Ca influx was measured as a function of the transmembrane gradients of Na and K and changes in the permeability of the membrane to K and Cl produced by valinomycin and SITS (4-acetamido- 4'-isothiocyano-stilbene-2-2'-disulfonic acid), respectively. Changes in the rate of Ca influx are consistent with expected effects of these treatments on the membrane potential. Oligomycin (10 micrograms/ml) and quinidine (1 mM) inhibit the rate of Ca uptake by inhibiting Ca-induced changes in the K permeability. At constant membrane potential, furosemide produced a slight (15%) consistent increase in Ca uptake. Other experiments show that resealed ghosts are heterogeneous in their passive permeability to Ca and that A23187 can be used to effectively eliminate such differences. The results of this paper show that resealed human red cell ghosts containing arsenazo III can be used to continuously monitor intracellular free Ca and to study the factors that influence the permeability of the red cell membrane to Ca. PMID:6319541

  15. Comparisons between the 35 mm Quadrature Surface Resonator at 300 K and the 40 mm High-Temperature Superconducting Surface Resonator at 77 K in a 3T MRI Imager

    PubMed Central

    Song, Manli; Chen, Jyh-Horng; Chen, Ji; Lin, In-Tsang

    2015-01-01

    This study attempts to compare the signal-to-noise ratio (SNR) of the 40 mm High-Temperature Superconducting (HTS) surface resonator at 77 K and the 35 mm commercial quadrature (QD) surface resonator at 300 K in a 3 Tesla (T) MRI imager. To aquire images for the comparison, we implemented a phantom experiment using the 40 mm diameter Bi2Sr2Ca2Cu3Ox (Bi-2223) HTS surface resonator, the 35 mm commercial QD surface resonator and the 40 mm professionally-made copper surface resonator. The HTS surface resonator at 77 K provided a 1.43-fold SNR gain over the QD surface resonator at 300 K and provided a 3.84-fold SNR gain over the professionally-made copper surface resonator at 300 K on phantom images. The results agree with the predictions, and the difference between the predicted SNR gains and measured SNR gains is 1%. Although the geometry of the HTS surface resonator is different from the QD surface resonator, its SNR is still higher. The results demonstrate that a higher image quality can be obtained with the HTS surface resonator at 77 K. With the HTS surface resonator, the SNR can be improved, suggesting that the HTS surface resonator is a potentially helpful diagnostic tool for MRI imaging in various applications. PMID:25812124

  16. Ca-mediated and independent effects of arachidonic acid on gap junctions and Ca-independent effects of oleic acid and halothane.

    PubMed

    Lazrak, A; Peres, A; Giovannardi, S; Peracchia, C

    1994-09-01

    In Novikoff hepatoma cell pairs studied by double perforated patch clamp (DPPC), brief (20 s) exposure to 20 microM arachidonic acid (AA) induced a rapid and reversible uncoupling. In pairs studied by double whole-cell clamp (DWCC), uncoupling was completely prevented by effective buffering of Cai2+ with BAPTA. Similarly, AA (20 s) had no effect on coupling in cells perfused with solutions containing no added Ca2+ (SES-no-Ca) and studied by DPPC, suggesting that Ca2+ influx plays an important role. Parallel experiments monitoring [Ca2+]i with fura-2 showed that [Ca2+]i increases with AA to 0.7-1.5 microM in normal [Ca2+]o, and to approximately 400 nM in SES-no-Ca solutions. The rate of [Ca2+]i increase matched that of Gj decrease, but [Ca2+]i recovery was faster. In cells studied by DWCC with 2 mM BAPTA in the pipette solution and superfused with SES-no-Ca, long exposure (1 min) to 20 microM AA caused a slow and virtually irreversible uncoupling. This result suggests that AA has a dual mechanism of uncoupling: one dominant, fast, reversible, and Ca(2+)-dependent, the other slow, poorly reversible, and Ca(2+)-independent. In contrast, uncoupling by oleic acid (OA) or halothane was insensitive to internal buffering with BAPTA, suggesting a Ca(2+)-independent mechanism only. PMID:7811915

  17. Topological organization of CA3-to-CA1 excitation.

    PubMed

    Hongo, Yoshie; Ogawa, Koichi; Takahara, Yuji; Takasu, Keiko; Royer, Sebastien; Hasegawa, Minoru; Sakaguchi, Gaku; Ikegaya, Yuji

    2015-09-01

    The CA1-projecting axons of CA3 pyramidal cells, called Schaffer collaterals, constitute one of the major information flow routes in the hippocampal formation. Recent anatomical studies have revealed the non-random structural connectivity between CA3 and CA1, but little is known regarding the functional connectivity (i.e. how CA3 network activity is functionally transmitted downstream to the CA1 network). Using functional multi-neuron calcium imaging of rat hippocampal slices, we monitored the spatiotemporal patterns of spontaneous CA3 and CA1 burst activity under pharmacological GABAergic blockade. We found that spatially clustered CA3 activity patterns were transformed into layered CA1 activity sequences. Specifically, synchronized bursts initiated from multiple hot spots in CA3 ensembles, and CA1 neurons located deeper in the pyramidal cell layer were recruited during earlier phases of the burst events. The order of these sequential activations was maintained across the bursts, but the sequence velocity varied depending on the inter-burst intervals. Thus, CA3 axons innervate CA1 neurons in a highly topographical fashion. PMID:26036915

  18. UV - RIVERSIDE CA

    EPA Science Inventory

    Brewer 112 is located in Riverside CA, measuring ultraviolet solar radiation. Irradiance and column ozone are derived from this data. Ultraviolet solar radiation is measured with a Brewer Mark IV, single-monochrometer, spectrophotometer manufactured by SCI-TEC Instruments, Inc. o...

  19. Flashlamp-pumped Ho:Tm:Cr:LuAG laser

    NASA Technical Reports Server (NTRS)

    Jani, Mahendra G. (Inventor); Barnes, Norman P. (Inventor); Murray, Keith E. (Inventor); Kokta, Milan R. (Inventor)

    1997-01-01

    A room temperature solid-state laser is provided. A laser crystal is disposed in a laser cavity. The laser crystal has a LuAG host material doped with a concentration of about 0.35% Ho ions, about 5.57% Tm ions and at least about 1.01% Cr ions. A broadband energizing source such as a flashlamp is disposed transversely to the laser crystal to energize the Ho ions, Tm ions and Cr ions.

  20. Registration of 'HoCP 91-552' sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    HoCP 91-552’ sugarcane was selected from progeny of the cross ‘LCP 81-10’ x ‘CP 72-356’ made at Canal Point, Florida. HoCP 91-552 was developed through cooperative research by the Agricultural Research Service of the United States Department of Agriculture’s Sugarcane Research Unit, the Louisiana A...

  1. TRPV1 regulates activation and modulation of TRPA1 by Ca2+

    PubMed Central

    Patil, Mayur J.; Jeske, Nathaniel A.; Akopian, Armen N.

    2010-01-01

    The transient receptor potential A1 (TRPA1) channel contributes to nociceptive signaling in certain pain models. It has been suggested that Ca2+, which activates and modulates TRPA1, could play a critical regulatory role in this process. Since TRPA1 and TRPV1 channels are co-expressed and interact in neurons, we investigated whether activation and modulation of TRPA1 by Ca2+ is regulated by TRPV1. Cell-attached recordings showed that TRPA1 is activated by extracellular Ca2+ ([Ca2+]e) in concentration-response fashion. This activation, especially by 2mM [Ca2+]e was substantially suppressed by co-expression with TRPV1. Inside-out recordings demonstrated that intracellular Ca2+ ([Ca2+]i)-triggered activation of TRPA1 was attenuated by the presence of TRPV1 only at 2 mM [Ca2+]e, but not in Ca2+-free conditions. Further, depletion of internal Ca2+ stores by thapsigargin generated TRPA1-mediated currents, which is affected by TRPV1 in both Chinee hamster ovary cells and sensory neurons. Since mustard oil current (IMO) is modulated by [Ca2+]e, we next examined whether alterations in the Ca2+-permeability of TRPV1 by mutating Y671 effect IMO properties. First it was demonstrated that the mutations in TRPV1 did not affect association of the TRPA1 and TRPV1 channels. However, these TRPV1 mutations, particularly Y671K, altered the following characteristics of TRPA1: magnitude of IMO in presence and absence of [Ca2+]e; the influence of [Ca2+]e on the voltage-dependency of IMO, and open probability of single-channel IMO. In summary, activation of TRPA1 by [Ca2+]e and [Ca2+]i is controlled by the TRPV1 channel, and characteristics of IMO depend on Ca2+ permeability of the TRPV1 channel. PMID:20884333

  2. Axonal Morphometry of Hippocampal Pyramidal Neurons Semi-Automatically Reconstructed After In-Vivo Labeling in Different CA3 Locations

    PubMed Central

    Ropireddy, Deepak; Scorcioni, Ruggero; Lasher, Bonnie; Buzsáki, Gyorgy; Ascoli, Giorgio A.

    2013-01-01

    Axonal arbors of principal neurons form the backbone of neuronal networks in the mammalian cortex. Three-dimensional reconstructions of complete axonal trees are invaluable for quantitative analysis and modeling. However, digital data are still sparse due to labor intensity of reconstructing these complex structures. We augmented conventional tracing techniques with computational approaches to reconstruct fully labeled axonal morphologies. We digitized the axons of three rat hippocampal pyramidal cells intracellularly filled in-vivo from different CA3 sub-regions: two from areas CA3b and CA3c, respectively, toward the septal pole, and one from the posterior/ventral area (CA3pv) near the temporal pole. The reconstruction system was validated by comparing the morphology of the CA3c neuron with that traced from the same cell by a different operator on a standard commercial setup. Morphometric analysis revealed substantial differences among neurons. Total length ranged from 200mm (CA3b) to 500mm (CA3c), and axonal branching complexity peaked between 1mm (CA3b and CA3pv) and 2mm (CA3c) of Euclidean distance from the soma. Length distribution was analyzed among sub-regions (CA3a,b,c and CA1a,b,c), cytoarchitectonic layers, and longitudinal extent within a three-dimensional template of the rat hippocampus. The CA3b axon extended thrice more collaterals within CA3 than into CA1. On the contrary, the CA3c projection was double into CA1 than within CA3. Moreover, the CA3b axon extension was equal between strata oriens and radiatum, while the CA3c axon displayed an oriens/radiatum ratio of 1:6. The axonal distribution of the CA3pv neuron was intermediate between those of the CA3b and CA3c neurons both relative to sub-regions and layers, with uniform collateral presence across CA3/CA1 and moderate preponderance of radiatum over oriens. In contrast with the dramatic sub-region and layer differences, the axon longitudinal spread around the soma was similar for the three neurons

  3. Rotational Spectroscopic Studies and Observational Searches for HO3

    NASA Astrophysics Data System (ADS)

    Widicus Weaver, Susanna

    Interstellar chemistry is largely driven by reactions of unstable molecules that serve as reaction intermediates in terrestrial chemistry. One such class of compounds are weakly-bound clusters. These clusters could form in interstellar environments through radiative association reactions, but their identification and characterization in interstellar environments is limited by a lack of rotational spectral information. One such species is HO3, which could be formed in the interstellar medium from O2 and OH. HO3 has been studied extensively in the infrared, and there are a few microwave spectral studies that have also been reported. However, no millimeter or submillimeter spectral information is available to guide astronomical observations. In this talk, we will present the laboratory characterization of trans -HO3 and trans -DO3 from 70 to 450 GHz using our newly developed fast sweeping technique. The molecular constants have been significantly refined, and additional higher order centrifugal distortion constants have been determined. We will also present an initial observational search for HO3 in 32 star forming regions. Although no HO3 lines have been detected thus far, strict upper limits can be placed on the HO3 column density in these sources based on this analysis. Additional Authors: Luyao Zou, Brian M. Hays.

  4. Effects of Ca2+ on phosphoinositide breakdown in exocrine pancreas.

    PubMed Central

    Taylor, C W; Merritt, J E; Putney, J W; Rubin, R P

    1986-01-01

    Recent studies have established that inositol 1,4,5-trisphosphate [I(1,4,5)P3] provides the link between receptor-regulated polyphosphoinositide hydrolysis and mobilization of intracellular Ca2+. Here, we report the effects of Ca2+ on inositol trisphosphate (IP3) formation from phosphatidylinositol bisphosphate (PIP2) catalysed by phospholipase C in intact and electrically permeabilized rat pancreatic acinar cells. In permeabilized cells, the Ca2+-mobilizing agonist caerulein stimulated [3H]IP3 formation when the free [Ca2+] was buffered at 140 nM, the cytosolic free [Ca2+] of unstimulated pancreatic acinar cells. When the free [Ca2+] was reduced to less than 10 nM, caerulein did not stimulate [3H]IP3 formation. Ca2+ in the physiological range stimulated [3H]IP3 formation and reduced the amount of [3H]PIP2 in permeabilized cells. The effects of Ca2+ and the receptor agonist caerulein were additive, but we have not established whether this reflects independent effects on the same or different enzymes. The effect of Ca2+ on [3H]IP3 formation by permeabilized cells was unaffected by inhibitors of the cyclo-oxygenase and lipoxygenase pathways of arachidonic acid metabolism; nor were the effects of Ca2+ mimicked by addition of arachidonic acid. These results suggest that the effects of Ca2+ on phospholipase C activity are not a secondary consequence of Ca2+ activation of phospholipase A2. Changes in free [Ca2+] (less than 10 nM-1.2 mM) did not affect the metabolism of exogenous [3H]I(1,4,5)P3 by permeabilized cells. In permeabilized cells, breakdown of exogenous [3H]IP3 to [3H]IP2 (inositol bisphosphate), and formation of [3H]IP3 in response to receptor agonists were equally inhibited by 2,3-bisphosphoglyceric acid. This suggests that the [3H]IP2 formed in response to receptor agonists is entirely derived from [3H]IP3. In intact cells, [3H]IP3 formation was stimulated when ionomycin was used to increase the cytosolic free [Ca2+]. However, a maximal concentration of

  5. On Hořava-Lifshitz cosmology

    NASA Astrophysics Data System (ADS)

    Chen, Bin

    2011-05-01

    We give a brief overview of the Hořava-Lifshitz-gravity theory, its modifications and its implications in cosmology. In particular, we discuss the various issues on the gravitational scalar mode, including its decoupling, its role as inflaton and its stability. Our analysis shows that the scalar mode could decouple naturally at λ = 1 due to the extra gauge symmetry. On the other hand, the fact that the scalar mode becomes ghost when 1/3 < λ < 1 is a real challenge to the theory. We try to overcome this problem by modifying the action such that the RG flow lies outside the problematic region. We discuss the cosmological implications of the theory.

  6. Modulation of intracellular Ca2+ levels by Scorpaenidae venoms.

    PubMed

    Church, Jarrod E; Moldrich, Randal X; Beart, Philip M; Hodgson, Wayne C

    2003-05-01

    The crude venoms of the soldierfish (Gymnapistes marmoratus), the lionfish (Pterois volitans) and the stonefish (Synanceia trachynis) display pronounced neuromuscular activity. Since [Ca(2+)](i) is a key regulator in many aspects of neuromuscular function we sought to determine its involvement in the neuromuscular actions of the venoms. In the chick biventer cervicis muscle, all three venoms produced a sustained contraction (approx 20-30% of 1mM acetylcholine). Blockade of nicotinic receptors with tubocurarine (10 micro M) failed to attenuate the contractile response to either G. marmoratus venom or P. volitans venom, but produced slight inhibition of the response to S. trachynis venom. All three venoms produced a rise in intracellular Ca(2+) (approx. 200-300% of basal) in cultured murine cortical neurons. The Ca(2+)-channel blockers omega-conotoxin MVIIC, omega-conotoxin GVIA, omega-agatoxin IVa and nifedipine (each at 1 micro M) potentiated the increase in [Ca(2+)](i) in response to G. marmoratus venom and P. volitans venom, while attenuating the response to S. trachynis venom. Removal of extracellular Ca(2+), replacement of Ca(2+) with La(3+) (0.5mM), or addition of stonefish antivenom (3units/ml) inhibited both the venom-induced increase in [Ca(2+)](i) in cultured neurones and contraction in chick biventer cervicis muscle. Venom-induced increases in [Ca(2+)](i) correlated with an increased cell death of cultured neurones as measured using propidium iodide (1 micro g/ml). Morphological analysis revealed cellular swelling and neurite loss consistent with necrosis. These data indicate that the effects of all three venoms are due in part to an increase in intracellular Ca(2+), possibly via the formation of pores in the cellular membrane which, under certain conditions, can lead to necrosis. PMID:12727272

  7. Enhanced biohydrogen production from sugarcane bagasse by Clostridium thermocellum supplemented with CaCO3.

    PubMed

    Tian, Qing-Qing; Liang, Lei; Zhu, Ming-Jun

    2015-12-01

    Clostridium thermocellum ATCC 27405 was used to degrade sugarcane bagasse (SCB) directly for hydrogen production, which was significantly enhanced by supplementing medium with CaCO3. The effect of CaCO3 concentration on the hydrogen production was investigated. The hydrogen production was significantly enhanced with the CaCO3 concentration increased from 10mM to 20mM. However, with the CaCO3 concentration further increased from 20mM to 100mM, the hydrogen production didn't increase further. Under the optimal CaCO3 concentration of 20mM, the hydrogen production reached 97.83±5.19mmol/L from 2% sodium hydroxide-pretreated SCB, a 116.72% increase over the control (45.14±1.03mmol/L), and the yield of hydrogen production reached 4.89mmol H2/g SCBadded. Additionally, CaCO3 promoted the biodegradation of SCB and the growth of C. thermocellum. The stimulatory effects of CaCO3 on biohydrogen production are mainly attributed to the buffering capacity of carbonate. The study provides a novel strategy to enhance biohydrogen production from lignocellulose. PMID:26356113

  8. Numerical simulation on the solidification structure of Ø600mm continuous casting round bloom

    NASA Astrophysics Data System (ADS)

    Fang, Q.; Ni, H. W.; Wang, S. J.; Zang, H.

    2016-03-01

    A FE (Finite Element)—CA (Cellular Automation) coupling model was developed for the simulation of solidification structure formation during the Ø600mm round bloom continuous casting process of Q345E steel. The simulation result of the temperature field was consistent with the nail-shooting experimental result, and the simulated solidification structure of the bloom was in great agreement with corrosion testing under the same casting condition. The simulation results showed that the centre equiaxed crystal ratio increased slightly with the increase of secondary cooling water rate and decreased with the increase of casting temperature and casting speed. When the secondary cooling water rate was over 0.08L/kg, it had less effect on the solidification structure. As the casting temperature increased by 1°C or the casting speed increased by 0.01m/min, the centre equiaxed crystal ratio would decrease by 0.4%∼1.2% and 3%∼0.8% respectively. According to the simulation results, the optimized continuous casting process of Ø600mm round bloom should be the secondary cooling water rate of 0.08L/kg, the casting temperature of 1532°C∼1539°C and the casting speed of 0.20m/min∼0.22m/min. It was found that the solidification structure of Ø600mm Q345E steel round bloom was much improved after the optimized continuous casting process was adopted in practical production.

  9. Crystal-field excitations and magnetic properties of Ho{sup 3+} in HoVO{sub 4}

    SciTech Connect

    Skanthakumar, S.; Loong, C.; Soderholm, L.; Abraham, M.M.; Boatner, L.A.

    1995-05-01

    The magnetic excitations in HoVO{sub 4} were studied by neutron scattering and susceptibility techniques. Well-defined transitions between the crystal-field-split states of the Ho{sup 3+} ions were observed at 15, 40, and 100 K. The magnetic spectra were analyzed using a single-ion crystal-field model which includes intermediate coupling of the LS states of Ho. A quantitative comparison of the observed energies and intensities with the model was made and used to refine the five crystal-field parameters needed to calculate the Ho ionic wave functions and other magnetic properties. The nonmagnetic {Gamma}{sub 1}-singlet ground state (containing about 90% pure {vert_bar}8,0{r_angle} component) of the Ho ions, in conjunction with the next higher doublet state situated at 2.5 meV, strongly influences the low-temperature magnetic behavior. The calculated magnetic susceptibility, which exhibits an easy plane coinciding with the crystallographic {ital a}-{ital b} plane at low temperatures, agrees very well with the experimental data obtained from single-crystal measurements. The magnetic properties of HoVO{sub 4} are contrasted with those of an isostructural compound HoPO{sub 4} which has a 98% pure {vert_bar}8,7{r_angle}-doublet ground state. The difference in the crystal-field-level structure between these two compounds is reflected in a sign change of the {ital B}{sub 0}{sup 2} crystal-field parameter. Despite the overall tetragonal crystal structure of HoVO{sub 4}, which predicts double degeneracy for each {Gamma}{sub 5} state, a small splitting in the first-excited doublet was clearly observed at low temperatures.

  10. Intracellular Ca(2+) release as irreversible Markov process.

    PubMed Central

    Rengifo, Juliana; Rosales, Rafael; González, Adom; Cheng, Heping; Stern, Michael D; Ríos, Eduardo

    2002-01-01

    In striated muscles, intracellular Ca(2+) release is tightly controlled by the membrane voltage sensor. Ca(2+) ions are necessary mediators of this control in cardiac but not in skeletal muscle, where their role is ill-understood. An intrinsic gating oscillation of Ca(2+) release-not involving the voltage sensor-is demonstrated in frog skeletal muscle fibers under voltage clamp. A Markov model of the Ca(2+) release units is shown to reproduce the oscillations, and it is demonstrated that for Markov processes to have oscillatory transients, its transition rates must violate thermodynamic reversibility. Such irreversibility results in permanent cycling of the units through a ring of states, which requires a source of free energy. Inhibition of the oscillation by 20 to 40 mM EGTA or partial depletion of Ca(2+) in the sarcoplasmic reticulum (SR) identifies the SR [Ca(2+)] gradient as the energy source, and indicates a location of the critical Ca(2+)-sensing site at distances greater than 35 nm from the open channel. These results, which are consistent with a recent demonstration of irreversibility in gating of cardiac Ca(2+) sparks, (Wang, S.-Q., L.-S. Song, L. Xu, G. Meissner, E. G. Lakatta, E. Ríos, M. D. Stern, and H. Cheng. 2002. Biophys. J. 83:242-251) exemplify a cell-wide oscillation caused by coupling between ion permeation and channel gating. PMID:12414685

  11. Formation of asteroids from mm-cm sized grains

    NASA Astrophysics Data System (ADS)

    Carrera, D.; Johansen, A.; Davies, M. B.

    2014-03-01

    Context. Asteroids and comets are intricately connected to life in the universe. Asteroids are the building blocks of terrestrial planets; water-rich asteroids and comets are likely to be the primary source of water for Earth's oceans and other volatiles (Morbidelli et al. 2000; Hartogh et al. 2011); and they may play role in mass extinctions. Yet, the formation of these objects is poorly understood. There is mounting evidence that the traditional picture of the formation of asteroids must be revised. The size distribution of asteroids is hard to reconcile with a traditional bottomup formation scenario. Instead, asteroids may form top-down, with large 100 - 1000 km sized objects forming first by the gravitational collapse of dense clumps of small particles. Experiments and simulations suggest that dust grains cannot grow to sizes larger than mm-cm in protoplanetary disks (Zsom et al. 2010). Also, primitive meteorites from the asteroid belt contain a large mass fraction in chondrules of sizes from 0.1 mm to a few mm. Hence, it is desirable to find a model for asteroid formation from mm-sized particles. Aims. In this work, we model the dynamics of mm-cm sized grains in dust-enriched inner regions of protoplanetary disks. We model the dust-gas interaction to determine whether dust grains of this size can form dense, self-gravitating clouds that can collapse to form asteroids. Methods. We perform shearing box simulations of the inner disk using the Pencil Code (Brandenburg & Dobler 2002). The simulations start with a Solar-type solids-to-gas ratio of 0.01 and we gradually increase the particle concentration. In a real protoplanetary disk, solid particles are expected to migrate from the outer regions and concentrate in the inner disk. Results. Our simulations show that mm-sized particles can form very dense clumps, driven by a run-away convergence in the radial-drift flow of these particles - this dynamic is known as the streaming instability (Youdin & Goodman 2005

  12. Investigation of MM-PBSA rescoring of docking poses.

    PubMed

    Thompson, David C; Humblet, Christine; Joseph-McCarthy, Diane

    2008-05-01

    Target-based virtual screening is increasingly used to generate leads for targets for which high quality three-dimensional (3D) structures are available. To allow large molecular databases to be screened rapidly, a tiered scoring scheme is often employed whereby a simple scoring function is used as a fast filter of the entire database and a more rigorous and time-consuming scoring function is used to rescore the top hits to produce the final list of ranked compounds. Molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) approaches are currently thought to be quite effective at incorporating implicit solvation into the estimation of ligand binding free energies. In this paper, the ability of a high-throughput MM-PBSA rescoring function to discriminate between correct and incorrect docking poses is investigated in detail. Various initial scoring functions are used to generate docked poses for a subset of the CCDC/Astex test set and to dock one set of actives/inactives from the DUD data set. The effectiveness of each of these initial scoring functions is discussed. Overall, the ability of the MM-PBSA rescoring function to (i) regenerate the set of X-ray complexes when docking the bound conformation of the ligand, (ii) regenerate the X-ray complexes when docking conformationally expanded databases for each ligand which include "conformation decoys" of the ligand, and (iii) enrich known actives in a virtual screen for the mineralocorticoid receptor in the presence of "ligand decoys" is assessed. While a pharmacophore-based molecular docking approach, PhDock, is used to carry out the docking, the results are expected to be general to use with any docking method. PMID:18465849

  13. End design of the SSC 58 mm High Gradient Quadrupole

    SciTech Connect

    Caspi, S.

    1992-06-10

    The end'' design of the High Gradient Quad. was done with consideration to the integrated field harmonics, the iron contribution, and the maximum field at the conductor. Magnetic analysis was done on the return end only, however the physical dimension of the lead end were determined as well. Using the cross-section of the windings and Cook's program BEND, we generated the physical end windings around the return end. Placing a single wire at the center of each turn the integrated gradient was computed and iterating on the end block spacers the integrated harmonics minimized. The final geometry was then used for more, extensive calculations, such as the field at the conductor and the 3D field harmonics. For this detailed calculation we have placed a single line current at the center of each strand and included the iron contribution ({mu} = {infinity}), see Appendix C. With the termination of the iron serving as a reference, the maximum length of the inner and outer layers are 182 mm and 215 mm respectively. The magnetic length of the end was computed from the gradient function A{sub 2} and was found to be 142 mm. In reality we expect the physical length of the end to be somewhat larger, however this should have little or no effect on the magnetic length. The gradient in the straight section is 212.44 T/m at 7000 A and the integrated value of the gradient is -3.01665 E5 (G) in the end region marked by the magnetic length of the end. The respective integrated harmonics for the end 12 pole and 20 pole are -10.6658 (G/CM{sup 4}) and 0.7279 (G/cm{sup 8}) corresponding to b{sub 6} = 0.351 , b{sub 10} = -0.024 units. The above was computed from the values of A{sub 2}, A{sub 6}, and A{sub 10}.

  14. End design of the SSC 58 mm High Gradient Quadrupole

    SciTech Connect

    Caspi, S.

    1992-06-10

    The ``end`` design of the High Gradient Quad. was done with consideration to the integrated field harmonics, the iron contribution, and the maximum field at the conductor. Magnetic analysis was done on the return end only, however the physical dimension of the lead end were determined as well. Using the cross-section of the windings and Cook`s program BEND, we generated the physical end windings around the return end. Placing a single wire at the center of each turn the integrated gradient was computed and iterating on the end block spacers the integrated harmonics minimized. The final geometry was then used for more, extensive calculations, such as the field at the conductor and the 3D field harmonics. For this detailed calculation we have placed a single line current at the center of each strand and included the iron contribution ({mu} = {infinity}), see Appendix C. With the termination of the iron serving as a reference, the maximum length of the inner and outer layers are 182 mm and 215 mm respectively. The magnetic length of the end was computed from the gradient function A{sub 2} and was found to be 142 mm. In reality we expect the physical length of the end to be somewhat larger, however this should have little or no effect on the magnetic length. The gradient in the straight section is 212.44 T/m at 7000 A and the integrated value of the gradient is -3.01665 E5 (G) in the end region marked by the magnetic length of the end. The respective integrated harmonics for the end 12 pole and 20 pole are -10.6658 (G/CM{sup 4}) and 0.7279 (G/cm{sup 8}) corresponding to b{sub 6} = 0.351 , b{sub 10} = -0.024 units. The above was computed from the values of A{sub 2}, A{sub 6}, and A{sub 10}.

  15. Atomic distribution, local structure and cation size effect in o-R1-xCaxMnO3 (R = Dy, Y, and Ho)

    NASA Astrophysics Data System (ADS)

    Jiang, Ning; Zhang, X.; Yu, Yi

    2013-11-01

    We propose new interatomic potentials for the small rare-earth-based orthorhombic RMnO3 (R = Dy, Y, Ho), which accurately model the structural properties of these extreme cases of lanthanide manganate series. They are further employed to investigate the intrinsic defects in o-RMnO3 and the cation distribution and local structure in o-R1-xCaxMnO3 (R = Dy, Y, Ho). Schottky disorders are found to be the dominant structural defects, and the possibility of a small degree of anti-site disorder of R and Mn ions over A and B sites is found. The introduced Ca dopants tend to form chemically and structurally like CaMnO3 clusters in the lightly doped system, which can be regarded as representations of microscopic phase separation. The local structural disorder is reduced with increasing doping density. For o-R0.5Ca0.5MnO3 (R = Dy, Y, Ho), the charge ordering state is intrinsically favored, and the layer stripe model is shown to be energetically more favorable and structurally more reasonable. Moreover, the tendency to form charge ordered stripes increases with the decrease of R size. The local structure in the layer stripe pattern deviates largely from the average structure: RMnO3-like and CaMnO3-like layers are formed. The size of R ion has a significant influence on the doping effect on Jahn-Teller (JT) distortion and a manganate with a larger R will experience a larger reduction on the anisotropy of Mn-O bonds in Mn3+O6 octahedra. However, the change of octahedral tilting upon doping does not vary much with R radii.

  16. The role of Ca pathway in Cd uptake and translocation by the hyperaccumulator Sedum alfredii.

    PubMed

    Lu, Lingli; Tian, Shengke; Zhang, Min; Zhang, Jie; Yang, Xiaoe; Jiang, Hong

    2010-11-15

    Effect of Ca on plant growth, Cd uptake and translocation in the hyperaccumulator Sedum alfredii was investigated, as to reveal the possible pathway of Cd entry into the plants system. High Ca increased plant growth under Cd stress after 7 d, and significantly affected the total Cd influx and translocation rate. Short-term kinetics of (109)Cd influx performed using radiotracers confirmed a significant inhibition of (109)Cd influx into the roots induced by high Ca. Under exposure of 5.0 mM Ca, K(m) of (109)Cd influx into roots was 2-fold higher in the hyperaccumulator, although the V(max) value remained at similar level, when compared with the treatments of 0.5 mM Ca. Calcium concentrations in xylem sap of the hyperaccumulator decreased with the increasing Cd levels and significant negative correlationship between the two elements was observed. However, increased xylem loading of Cd was observed in the hyperaccumulator in response to the increasing exogenous Ca level from 0.5 to 4.0 mM, but reverse effect was observed when higher Ca levels (8-32 mM) were presented in the solutions. These results suggest that Cd uptake and translocation in the hyperaccumulator S. alfredii plants is positively associated with Ca pathway. PMID:20674155

  17. Planetary observations at a wavelength of 1. 32 mm

    SciTech Connect

    Ulich, B.L.; Dickel, J.R.; De Pater, I.

    1984-12-01

    Observations at a wavelength of 1.32 mm have been made of the Jovian planets, Ceres, the satellites Callisto and Ganymede, and the HII region DR 21. The observed brightness temperatures are presented. Those of the Jovian planets agree with the values expected from model atmosphere calculations, except that of Jupiter, which is lower than expected. Ceres and the satellites do not have atmospheres so their emission arised in their subsurface layers. The observed brightness temperatures are intermediate between those measured at infrared and centimeter wavelengths. 30 references.

  18. Living with Omniback and the 8mm drive

    SciTech Connect

    Jones, M.C.

    1990-01-01

    Apollo's OmniBack backup system provides a convenient and effective way of storing network backup information on 8mm tape. In addition it has a journaling facility to write extensive log files, recording the backup process in almost any degree of detail desired. The directory structure and file names used are logical and well-defined. Summary files announce the degree of success of the backup as specified in the work file. The system will run unattended under the UNIX cron command, allowing the backup to be performed during the night when user demands on the network are small and most user files are free.

  19. Slow Slip Events on a 760 mm Long Granite Sample

    NASA Astrophysics Data System (ADS)

    Mclaskey, G.; Yamashita, F.

    2015-12-01

    We describe slow slip events and dynamic rupture events generated on a newly constructed large-scale biaxial friction apparatus at Cornell University that provide insights into the mechanisms of aseismic and seismic slip. We find that, under nominally similar experimental conditions, the 760 mm long granite sample sometimes slips in dynamic stick-slip events and sometimes relieves accumulated shear stress through slow slip events. To provide insights into this curious behavior and the underlying mechanisms, fault slip and shear stress are each measured at 8 locations along the 760 mm long fault. This allows us to map slow slip fronts and the nucleation and propagation of dynamic fault rupture. The granite sample is also instrumented with an array of piezoelectric sensors that are the laboratory equivalent of a seismic network. When the sample is loaded relatively slowly, at 0.03 MPa/s, slow slip occurs on large sections of the fault and the slow slipping region soon expands to the sample boundary. In this case, stress is released in a slow slip event with peak slip velocities < 2 mm/s. Alternatively, when one end of the sample is loaded rapidly (4 MPa/s), or the sample is allowed to heal in stationary contact for a few minutes, slow slip initiates near the load point and accelerates to slip velocities exceeding 200 mm/s before the slow slipping region expands all the way to the sample boundary. This produces a dynamic slip event (stick-slip). The dynamic slip events radiate seismic waves equivalent to a M = -2.5 earthquake. In contrast, the laboratory-generated slow slip events are predominantly aseismic and produce only bursts of tiny and discrete seismic events (M = -6) reminiscent of swarms of microseismicity. The experiments illustrate how a single fault can slide slowly and aseismically or rapidly and dynamically depending on stress state and loading conditions. We compare the behavior observed on this Cornell apparatus to the behavior of other large

  20. Herschel and Planck: surprises in the sub-mm band

    NASA Astrophysics Data System (ADS)

    González-Nuevo González, J.

    2015-05-01

    This paper focused on three of the most spectacular and almost unexpected results obtained from the observations in the sub-mm band coming from the ESA's Herschel and Planck missions: the detection of hundred of strongly lensed galaxies, the identification of high-z proto-clusters, and the study of the weak lensing signal through the cross-correlation analysis. Although, there were theoretical works that anticipate them, none of these interesting results appeared in the original scientific programs of both mission. For this reason we have called them ``surprises''.

  1. Gas Analysis by Fourier Transform Mm-Wave Spectroscopy

    NASA Astrophysics Data System (ADS)

    Harris, Brent J.; Steber, Amanda L.; Lehmann, Kevin K.; Pate, Brooks H.

    2013-06-01

    Molecular rotational spectroscopy of low pressure, room temperature gases offers high chemical selectivity and sensitivity with the potential for a wide range of applications in gas analysis. A strength of the technique is the potential to identify molecules that have not been previously studied by rotational spectroscopy by comparing experimental results to predictions of the spectroscopic parameters from quantum chemistry -6 so called library-free detection. The development of Fourier transform mm-wave spectrometers using high peak power (30 mW) active multiplier chain mm-wave sources brings new measurement capabilities to the analysis of complex gas mixtures. Strategies for gas analysis based on high-throughput mm-wave spectroscopy and arbitrary waveform generator driven mm-wave sources are described. Several new measurement capabilities come from the intrinsic time-domain measurement technique. High-sensitivity double-resonance measurements can be performed to speed the analysis of a complex gas sample containing several species. This technique uses a "pi-pulse" to selectively invert the population of two selected rotational energy levels and the effect of this excitation pulse on all other transitions in the spectrometer operating range is monitored using segmented chirped-pulse Fourier transform spectroscopy. This method can lead to automated determination of the molecular rotational constants. Rapid pulse duration scan experiments can be used to estimate the magnitude and direction of the dipole moment of the molecule from an unknown spectrum. Coherent pulse echo experiments, using the traditional Hahn sequence or two-color population recovery methods, can be used to determine the collisional relaxation rate of the unknown molecule. This rate determination improves the ability to estimate the mass of the unknown molecule from the determination of the Doppler dephasing rate. By performing a suite of automated, high-throughput measurements, there is the

  2. Synergies with ALMA and mm/submm facilities

    NASA Astrophysics Data System (ADS)

    Russell, H.; McNamara, B.; Fabian, A.

    2016-06-01

    New sub-mm facilities, such as ALMA, have opened up exciting new areas of astrophysics. I will review some of ALMA's exciting discoveries from the first five years of science including observations of massive molecular gas flows at the centres of nearby galaxies. Feedback from a central active galactic nucleus is thought to regulate the growth of massive galaxies by suppressing gas cooling and star formation. I will also focus on the potential contribution that XMM-Newton observations could make to these fields over the next decade.

  3. Dynamic impact analysis of the M1 105mm projectile

    SciTech Connect

    Walls, J.C.; Webb, D.S.

    1993-06-01

    Evaluation of the effects of {open_quotes}rough-handling{close_quotes}-induced stresses in the nose region of a 105mm artillery projectile was performed to determine if these stresses could have contributed to the premature explosion of a projectile during a Desert Shield training mission of the 101st Army Airborne in Saudi Arabia. The rough-handling evaluations were simulated by dynamic impact analysis. It was concluded that the combined residual stress and dynamic impact-induced stress would not be of sufficient magnitude to cause cracking of the projectile in the nose region.

  4. Dynamic impact analysis of the M1 105mm projectile

    SciTech Connect

    Walls, J.C.; Webb, D.S.

    1993-06-01

    Evaluation of the effects of [open quotes]rough-handling[close quotes]-induced stresses in the nose region of a 105mm artillery projectile was performed to determine if these stresses could have contributed to the premature explosion of a projectile during a Desert Shield training mission of the 101st Army Airborne in Saudi Arabia. The rough-handling evaluations were simulated by dynamic impact analysis. It was concluded that the combined residual stress and dynamic impact-induced stress would not be of sufficient magnitude to cause cracking of the projectile in the nose region.

  5. Reaction of HO2 with O3 and the effect of water vapor on HO2 kinetics

    NASA Technical Reports Server (NTRS)

    Demore, W. B.

    1979-01-01

    The effects of temperature and water vapor concentration on the ratio of the rate constant of the reaction HO2 + O3 yields OH + 2(O2) to the square root of the rate constant for the reaction HO2 + HO2 yields H2O2 + O2 are determined. Photolysis of H2-O2-O3 mixtures at 253.7 nm was carried out with H2O pressures in the range 0 to 15 torr at a temperature range of -42.5 to 61 C along with 184.9 nm photolysis of H2O-O2-O3 mixtures. It is shown that the rate of O3 photolysis is suppressed by the addition of water vapor and it is suggested that this effect is realized in the HO2 + HO2 yields H2O2 + O2 reaction. The calculated expression for the temperature dependence of the rate constant ratio is found to be in good agreement with that calculated from separate rate constants. Rate constants determined for the reaction OH + HO2 yields H2O + O2 are found to be higher than those previously determined, presumably due to increased pressure, indicating that atmospheric models should take into account the possible pressure dependences of the reactions considered.

  6. The Influence of Sarcoplasmic Reticulum Ca2+ Concentration on Ca2+ Sparks and Spontaneous Transient Outward Currents in Single Smooth Muscle Cells

    PubMed Central

    ZhuGe, Ronghua; Tuft, Richard A.; Fogarty, Kevin E.; Bellve, Karl; Fay, Fredric S.; Walsh, John V.

    1999-01-01

    Localized, transient elevations in cytosolic Ca2+, known as Ca2+ sparks, caused by Ca2+ release from sarcoplasmic reticulum, are thought to trigger the opening of large conductance Ca2+-activated potassium channels in the plasma membrane resulting in spontaneous transient outward currents (STOCs) in smooth muscle cells. But the precise relationships between Ca2+ concentration within the sarcoplasmic reticulum and a Ca2+ spark and that between a Ca2+ spark and a STOC are not well defined or fully understood. To address these problems, we have employed two approaches using single patch-clamped smooth muscle cells freshly dissociated from toad stomach: a high speed, wide-field imaging system to simultaneously record Ca2+ sparks and STOCs, and a method to simultaneously measure free global Ca2+ concentration in the sarcoplasmic reticulum ([Ca2+]SR) and in the cytosol ([Ca2+]CYTO) along with STOCs. At a holding potential of 0 mV, cells displayed Ca2+ sparks and STOCs. Ca2+ sparks were associated with STOCs; the onset of the sparks coincided with the upstroke of STOCs, and both had approximately the same decay time. The mean increase in [Ca2+]CYTO at the time and location of the spark peak was ∼100 nM above a resting concentration of ∼100 nM. The frequency and amplitude of spontaneous Ca2+ sparks recorded at −80 mV were unchanged for a period of 10 min after removal of extracellular Ca2+ (nominally Ca2+-free solution with 50 μM EGTA), indicating that Ca2+ influx is not necessary for Ca2+sparks. A brief pulse of caffeine (20 mM) elicited a rapid decrease in [Ca2+]SR in association with a surge in [Ca2+]CYTO and a fusion of STOCs, followed by a fast restoration of [Ca2+]CYTO and a gradual recovery of [Ca2+]SR and STOCs. The return of global [Ca2+]CYTO to rest was an order of magnitude faster than the refilling of the sarcoplasmic reticulum with Ca2+. After the global [Ca2+]CYTO was fully restored, recovery of STOC frequency and amplitude were correlated with the

  7. Heterogeneities in ICC Ca2+ activity within canine large intestine

    PubMed Central

    Lee, Hyun-Tai; Hennig, Grant W.; Park, Kyu Joo; Bayguinov, Peter O.; Ward, Sean M.; Sanders, Kenton M.; Smith, Terence K.

    2016-01-01

    Background & Aims In human and canine colon, both slow (slow waves, 2–8/min) and fast (myenteric potential oscillations; MPOs, 16–20/min) electrical rhythms in the smooth muscle originate at the submucosal and myenteric borders, respectively. We used Ca2+ imaging to investigate whether ICC at these borders generated distinct rhythms. Methods Segments of canine colon were pinned submucosal or myenteric surface uppermost, or cut in cross-section. Tissues were loaded with a Ca2+ indicator (fluo-4) and activity was monitored at 36.5±0.5°C using a CCD camera. Results Rhythmic, biphasic Ca2+ transients (5–8/min), similar in waveform to electrical slow waves, propagated without decrement as a wave front through the ICC-SM network (2–5mm/s), decaying exponentially through the thickness of the CM. In contrast, rhythmic intracellular Ca2+ waves (~16/min) and spontaneous reductions in Ca2+ were observed in ICC-MY. Normally, intracellular Ca2+ waves were unsynchronized between adjacent ICC-MY, although excitatory nerve activity synchronized activity. In addition, spontaneous reductions in Ca2+ were observed that inhibited Ca2+ waves. L-NA (100µM; NO antagonist) blocked the reductions in Ca2+ and increased the frequency (~19/min) of intracellular Ca2+ waves within ICC-MY. Conclusions ICC-SM form a tightly coupled network that is able to generate and propagate slow waves. In contrast, Ca2+ transients in ICC-MY, which are normally not synchronized, have a similar duration and frequency as MPOs. Like MPOs, their activity is inhibited by nitrergic nerves and synchronized by excitatory nerves. PMID:19268670

  8. Acute hypoxia activates store-operated Ca2+ entry and increases intracellular Ca2+ concentration in rat distal pulmonary venous smooth muscle cells

    PubMed Central

    Peng, Gongyong; Lu, Wenju; Zhong, Nanshan

    2013-01-01

    Rationale Exposure to acute hypoxia causes vasoconstriction in both pulmonary arteries (PA) and pulmonary veins (PV). The mechanisms on the arterial side have been studied extensively. However, bare attention has been paid to the venous side. Objectives To investigate if acute hypoxia caused the increase of intracellular Ca2+ concentration ([Ca2+]i), and Ca2+ influx through store-operated calcium channels (SOCC) in pulmonary venous smooth muscle cells (PVSMCs). Methods Fluorescent microscopy and fura-2 were used to measure effects of 4% O2 on [Ca2+]i and store-operated Ca2+ entry (SOCE) in isolated rat distal PVSMCs. Measurements and main results In PVSMCs perfused with Ca2+-free Krebs Ringer bicarbonate solution (KRBS) containing cyclopiazonic acid to deplete Ca2+ stores in the sarcoplasmic reticulum (SR) and nifedipine to prevent Ca2+ entry through L-type voltage-depended Ca2+ channels (VDCC), hypoxia markedly enhanced both the increase in [Ca2+]i caused by restoration of extracellular [Ca2+] and the rate at which extracellular Mn2+ quenched fura-2 fluorescence. Moreover, the increased [Ca2+]i in PVSMCs perfused with normal salt solution was completely blocked by SOCC antagonists SKF-96365 and NiCl2 at concentrations that SOCE >85% was inhibited but [Ca2+]i responses to 60 mM KCl were not altered. On the contrary, L-type VDCC antagonist nifedipine inhibited increase in [Ca2+]i to hypoxia by only 50% at concentrations that completely blocked responses to KCl. The increased [Ca2+]i caused by hypoxia was completely abolished by perfusion with Ca2+-free KRBS. Conclusions These results suggest that acute hypoxia enhances SOCE via activating SOCCs, leading to increased [Ca2+]i in distal PVSMCs. PMID:24255773

  9. QM/MM Molecular Dynamics Studies of Metal Binding Proteins

    PubMed Central

    Vidossich, Pietro; Magistrato, Alessandra

    2014-01-01

    Mixed quantum-classical (quantum mechanical/molecular mechanical (QM/MM)) simulations have strongly contributed to providing insights into the understanding of several structural and mechanistic aspects of biological molecules. They played a particularly important role in metal binding proteins, where the electronic effects of transition metals have to be explicitly taken into account for the correct representation of the underlying biochemical process. In this review, after a brief description of the basic concepts of the QM/MM method, we provide an overview of its capabilities using selected examples taken from our work. Specifically, we will focus on heme peroxidases, metallo-β-lactamases, α-synuclein and ligase ribozymes to show how this approach is capable of describing the catalytic and/or structural role played by transition (Fe, Zn or Cu) and main group (Mg) metals. Applications will reveal how metal ions influence the formation and reduction of high redox intermediates in catalytic cycles and enhance drug metabolism, amyloidogenic aggregate formation and nucleic acid synthesis. In turn, it will become manifest that the protein frame directs and modulates the properties and reactivity of the metal ions. PMID:25006697

  10. Stress relaxation in SSC 50mm dipole coils

    SciTech Connect

    Rogers, D.; Markley, F.

    1992-04-01

    We are measuring the stress relaxation of SSC 50mm outer coils with the goal of predicting how much of the coil prestress will be lost while the coils are warehoused between manufacture and cooldown. We manufacture 3 inch (76.2mm) long segments of coil with the same materials and techniques that have been used for prototype coils. We are running four simultaneous tests in an attempt to separate the contributions of the different coil materials. Test one is a completely insulated coil section where the insulation is the all polyamide system being tested at Brookhaven; test two is a wire stack insulated only with the normal Kapton overwrap; test three is a stack of bare cable; and test four is a completely insulated normal coil section. All, except for the bare cable, include the ground insulation. The insulated coil sections are carefully dried before loading and testing in order to eliminate stress changes due to varying moisture content. The temperature dependence of the stress relaxation is being studied separately. Three companion papers presented at this conference will be: (1) Temperature dependence of the viscoelastic properties of SSC coil insulation'' (2) Measurement of the elastic modulus of Kapton perpendicular to the plane of the film at room and cryogenic temperatures'' (3) Theoretical methods for creep and stress relaxation studies of SSC coil.''

  11. Using 70-mm aerial photography to identify rangeland sites

    NASA Technical Reports Server (NTRS)

    Everitt, J. H.; Gerbermann, A. H.; Alaniz, M. A.; Bowen, R. L.

    1980-01-01

    A south Texas rangeland area was used as a study site to test the use of microdensitometry on 70-mm color-infrared and black-and-white photographs (scale 1:19,000) for distinguishing among 11 range sites (two brushland, seven grassland, two barren land) during the winter (February), spring (May), and summer (August) of 1976. Color-infrared photographs were also taken at a scale of 1:42,000 for the summer date. Film optical density readings were made on one color-infrared film with white light only. The best separations among density readings for all range sites were obtained using white light exposed on color-infrared film in the summer when vegetation was at peak foliage development. Results from this study indicate that 70-mm aerial color-infrared photography at a scale of 1:19,000 or 1:42,000 has good potential for identifying range sites in large and inaccessible areas, and could be a useful tool for range management.

  12. Resonant biaxial 7-mm MEMS mirror for omnidirectional scanning

    NASA Astrophysics Data System (ADS)

    Hofmann, U.; Aikio, M.; Janes, J.; Senger, F.; Stenchly, V.; Weiss, M.; Quenzer, H.-J.; Wagner, B.; Benecke, W.

    2013-03-01

    Low-cost automotive laser scanners for environment perception are needed to enable the integration of advanced driver assistant systems (ADAS) into all automotive vehicle segments, a key to reducing the number of traffic accidents on roads. An omnidirectional 360 degree laser scanning concept has been developed based on combination of an omnidirectional lens and a biaxial large aperture MEMS mirror. This omnidirectional scanning concept is the core of a small sized low-cost time-of-flight based range sensor development. This paper describes concept, design, fabrication and first measurement results of a resonant biaxial 7mm gimbal-less MEMS mirror that is electrostatically actuated by stacked vertical comb drives. Identical frequencies of the two resonant axes are necessary to enable the required circle scanning capability. A tripod suspension was chosen since it allows minimizing the frequency splitting of the two resonant axes. Low mirror curvature is achieved by a thickness of the mirror of more than 500 μm. Hermetic wafer level vacuum packaging of such large mirrors based on multiple wafer bonding has been developed to enable to achieve a large mechanical tilt angle of +/- 6.5 degrees in each axis. The 7mm-MEMS mirror demonstrates large angle circular scanning at 1.5kHz.

  13. Experimental demonstration of a 120-mm ram accelerator

    NASA Astrophysics Data System (ADS)

    Kruczynski, David L.

    1992-10-01

    Ram acceleration is an emerging propulsion technology in which a projectile similar in shape to the centerbody of a ramjet aircraft engine is injected at high speed into a tube filled with a combustible gaseous mixture. As the projectile moves into the tube, under supersonic conditions, shocks occur on and around the projectile. If the gases are then ignited either by the energy in the shock system or an external mechanism, the combustion around or behind the projectile can be self-sustaining. The net effect is to generate a localized high pressure region around and/or behind the projectile which produces acceleration. Work at the University of Washington, Seattle, has demonstrated velocities in excess of 2.6 km/s in 38-mm caliber, while theory predicts velocities above 7 km/s may be obtainable. A program was initiated at the Weapons Technology Directorate of the US Army Research Laboratory (formerly Ballistic Research Laboratory) to examine the scaling potential of ram acceleration for use as a high velocity, high mass, (i.e., high kinetic energy) launcher. Data from initial gas mixing tests and first firings through a 120-mm bore diameter ram accelerator with both inert and live fuel gases are presented. Initial comparisons with ram accelerators of smaller scale are made. Discussions of scaling parameters as currently understood will be presented.

  14. Cycloid spirals and cycloid cone transition in the HoMn6-xCrxGe6 (T, x) magnetic phase diagramm by neutron diffraction

    NASA Astrophysics Data System (ADS)

    Schobinger-Papamantellos, P.; Rodríguez-Carvajal, J.; Buschow, K. H. J.

    2016-06-01

    The structures and magnetic properties of the antiferromagnetic hexagonal pseudo ternary compounds HoMn6-xCrxGe6 (x=1, 1.5 and 2) are studied by neutron diffraction in the temperature range 1.5-300 K. The substitution of nonmagnetic Cr for Mn greatly affects the magnetic properties of HoMn6Ge6 by reducing the ordering temperature from 466 K to 278 K, 205 K and 130 K for (x=0, 1, 1.5 and 2) respectively, increasing the c/a ratio, suppressing the high temperature (HT) commensurate phase with q2=(0, 0, 1/2) and changing the high temperature (LT) q1=(0, 0, q1z) skew spiral rotation plane. HoMn5CrGe6 and HoMn4Cr2Ge6 display in the entire magnetically ordered regime cycloid spiral structures with the wave vector: q=(0, 0, qz), qz≈0.18(3) r.l.u. and Φs≈64.8° turn angle. The Ho and Mn/Cr (001) layers have ferromagnetic arrangements coupled antiferromagnetically. The Ho moments in the z=0 layer are oriented in a direction opposite to the line bisecting the angle 2φMn≈2×28° of the Mn layers at z=±∼0.25. This triple unit changes orientation collectively in the direction of q within the (b, c) plane containing the wave vector. Above 50 K, the wave vector length increases linearly from 0.24 to 0.28(1) r.l.u. below TN. The HT HoMn4.5Cr1.5Ge6 cycloid spiral, is stable in the range Tt

  15. Tissue damage by laser radiation: an in vitro comparison between Tm:YAG and Ho:YAG laser on a porcine kidney model.

    PubMed

    Huusmann, Stephan; Wolters, Mathias; Kramer, Mario W; Bach, Thorsten; Teichmann, Heinrich-Otto; Eing, Andreas; Bardosi, Sebastian; Herrmann, Thomas R W

    2016-01-01

    :YAG) on the high power setting. Incision depth was 1214 ± 888 µm for Ho:YAG whereas Tm:YAG did not cut tissue at 5 W in saline solution. On the high power setting, the incision depth was 4050 ± 1058 µm for Tm:YAG and 4083 ± 520 µm for Ho:YAG. Both lasers create similar laser damage zones of <1 mm in ambient air and in saline solution. These in vitro experiments correspond well with in vivo experiments. Thereby, Tm:YAG offers a cutting performance, coagulation and safety profile similar to the standard Ho:YAG lasers in urological surgery. PMID:27006875

  16. Nitric oxide inhibits capacitative Ca2+ entry by suppression of mitochondrial Ca2+ handling

    PubMed Central

    Thyagarajan, Baskaran; Malli, Roland; Schmidt, Kurt; Graier, Wolfgang F; Groschner, Klaus

    2002-01-01

    Nitric oxide (NO) is a key modulator of cellular Ca2+ signalling and a determinant of mitochondrial function. Here, we demonstrate that NO governs capacitative Ca2+ entry (CCE) into HEK293 cells by impairment of mitochondrial Ca2+ handling. Authentic NO as well as the NO donors 1-[2-(carboxylato)pyrrolidin-1-yl]diazem-1-ium-1,2-diolate (ProliNO) and 2-(N,N-diethylamino)-diazenolate-2-oxide (DEANO) suppressed CCE activated by thapsigargin (TG)-induced store depletion. Threshold concentrations for inhibition of CCE by ProliNO and DEANO were 0.3 and 1 μM, respectively. NO-induced inhibition of CCE was not mimicked by peroxynitrite (100 μM), the peroxynitrite donor 3-morpholino-sydnonimine (SIN-1, 100 μM) or 8-bromoguanosine 3′,5′-cyclic monophosphate (8-BrcGMP, 1 mM). In addition, the guanylyl cyclase inhibitor 1H-[1,2,4] oxadiazole[4,3-a] quinoxalin-1-one (ODQ, 30 μM) failed to antagonize the inhibitory action of NO on CCE. DEANO (1–10 μM) suppressed mitochondrial respiration as evident from inhibition of cellular oxygen consumption. Experiments using fluorescent dyes to monitor mitochondrial membrane potential and mitochondrial Ca2+ levels, respectively, indicated that DEANO (10 μM) depolarized mitochondria and suppressed mitochondrial Ca2+ sequestration. The inhibitory effect of DEANO on Ca2+ uptake into mitochondria was confirmed by recording mitochondrial Ca2+ during agonist stimulation in HEK293 cells expressing ratiometric-pericam in mitochondria. DEANO (10 μM) failed to inhibit Ba2+ entry into TG-stimulated cells when extracellular Ca2+ was buffered below 1 μM, while clear inhibition of Ba2+ entry into store depleted cells was observed when extracellular Ca2+ levels were above 10 μM. Moreover, buffering of intracellular Ca2+ by use of N,N′-[1,2-ethanediylbis(oxy-2,1-phenylene)] bis [N-[25-[(acetyloxy) methoxy]-2-oxoethyl

  17. Growth-inhibitory effects of a mineralized extract from the red marine algae, Lithothamnion calcareum, on Ca2+-sensitive and Ca2+-resistant human colon carcinoma cells

    PubMed Central

    Nadeem Aslam, Muhammad; Bhagavathula, Narasimharao; Paruchuri, Tejaswi; Hu, Xin; Chakrabarty, Subhas; Varani, James

    2009-01-01

    Proliferation and differentiation were assessed in a series of human colon carcinoma cell lines in response to a mineral-rich extract derived from the red marine algae, Lithothamnion calcareum. The extract contains 12% Ca2+, 1% Mg2+, and detectable amounts of 72 trace elements, but essentially no organic material. The red algae extract was as effective as inorganic Ca2+ alone in suppressing growth and inducing differentiation of colon carcinoma cells that are responsive to a physiological level of extracellular Ca2+ (1.4 mM). However, with cells that are resistant to Ca2+ alone, the extract was still able to reduce proliferation and stimulate differentiation. PMID:19394137

  18. 2.07-micron CW diode-laser-pumped Tm,Ho:YLiF4 room-temperature

    NASA Technical Reports Server (NTRS)

    Hemmati, Hamid

    1989-01-01

    Continuous-wave action is obtained at 2.07 microns from a 2-mm-long Tm-sensitized Ho:YLiF4 crystal at room temperature when longitudinally pumped by a pair of diode-laser arrays. Laser output power at 300 K is 26 mW, with a 30-percent slope efficiency and a lasing threshold of 108 mW. A maximum output power of 187 mW is obtained from a 4-mm-long crystal at 77 K, with a 67 percent slope efficiency. A preliminary demonstration of cavity Q switching produced 165 microJ of pulse energy at a repetition rate of 100 Hz.

  19. Is HO{sup 2 sub +} a detectable interstellar molecule?

    SciTech Connect

    Widicus Weaver, S. L.; Woon, D. E.; Ruscic, B.; McCall, B. J.; Chemical Sciences and Engineering Division; Univ. of Illinois

    2009-05-20

    Although molecular oxygen, O{sub 2}, has long been thought to be present in interstellar environments, it has only been tentatively detected toward one molecular cloud. The fractional abundance of O{sub 2} determined from these observations is well below that predicted by astrochemical models. Given the difficulty of O{sub 2} observations from ground-based telescopes, identification of a molecule that could be used as a tracer of O{sub 2} in interstellar environments would be quite useful. To this end, we have undertaken a collaborative examination of HO{sub 2}{sup +} in an attempt to evaluate the feasibility of its detection in interstellar clouds. We have conducted high-level ab initio calculations of its structure to obtain its molecular parameters. The reaction responsible for the formation of HO{sub 2}{sup +} is nearly thermoneutral, and so a careful analysis of its thermochemistry was also required. Using the Active Thermochemical Tables approach, we have determined the most accurate values available to date for the proton affinities of O{sub 2} and H{sub 2}, and the enthalpy, Gibbs energy, and equilibrium constant for the reaction H{sub 3}{sup +} + O{sub 2} {yields} HO{sub 2}{sup +} + H{sub 2}. We find that while this reaction is endothermic by 50 {+-} 9 cm{sup -1} at 0 K, its equilibrium is shifted toward HO{sub 2}{sup +} at the higher temperatures of hot cores. We have examined the potential formation and destruction pathways for HO{sub 2}{sup +} in interstellar environments. Combining this information, we estimate the HO{sub 2}{sup +} column density in dense clouds to be {approx}10{sup 9} cm{sup -2}, which corresponds to line brightness temperatures of {le} 0.2 mK. If our results prove correct, HO{sub 2}{sup +} is clearly not a detectable interstellar molecule.

  20. A Single Site mutation (F429H) Converts the Enzyme CYP 2B4 into a Heme Oxygenase: A QM/MM Study

    PubMed Central

    Usharani, Dandamudi; Zazza, Costantino; Lai, Wenzhen; Chourasia, Mukesh

    2012-01-01

    The intriguing deactivation of the cytochrome P450 (CYP) 2B4 enzyme induced by a mutation of a single residue, Phe429 to His, is explored by means of quantum mechanical/molecular mechanical (QM/MM) calculations of the O-OH bond activation of the (Fe3+OOH)− intermediate. It is found that the F429H mutant of CYP 2B4 undergoes homolytic, instead of heterolytic, O-OH bond cleavage. Thus, the mutant acquires the following characteristics of a heme oxygenase (HO) enzyme: (a) The donation by His429 of an additional NH---S H-bond to the cysteine ligand combined with the presence of the substrate retard the heterolytic cleavage and give rise to homolytic O-OH cleavage, and (b) the Thr302/water cluster orients the nascent OH• close to the meso position of the porphyrin, and ensures an efficient meso hydroxylation. PMID:22356576

  1. Helical magneto-cumulative generator 280 mm in diameter

    NASA Astrophysics Data System (ADS)

    Demidov, V. A.; Kazakov, S. A.; Boriskin, A. S.; Vlasov, Yu. V.; Yanenko, V. A.; Nikolaev, N. I.; Volodchenkov, S. I.

    2015-01-01

    Several possibilities of preamplifier energy and power increasing are considered: using a more powerful (HMX-based) conical HE-charge in the central tube of the magneto-cumulative generator, using a magnetic flux finish pressing out device with axial initiation of the HE charge, and increasing the inner diameter of the helix. A magneto-cumulative generator (MCG) with a helix 280 mm in diameter (MCG-280) is developed. The new preamplifier has a power of ≈400 GW and is able to power a ten-element DMCG480 with an initial inductance of ≈0.2 µH by a current of ≈10 MA with a characteristic current rise time (by a factor of e at the final stage of its operation) τ e = 32 µs.

  2. Coil and iron design for SSC 50 mm magnet

    SciTech Connect

    Gupta, R.C.; Kahn, S.A.; Morgan, G.H.

    1990-01-01

    In this paper we present the design of the two dimensional coil and iron cross section, referred to as DSX201/W6733, for the 50 mm aperture dipole magnet being built at the Brookhaven National Laboratory for the Superconducting Super Collider (SSC). The computed values of the allowed field harmonics as a function of current, the quench performance predictions, the stored energy calculations, the effect of random errors on the coil placement and the Lorentz forces on the coil will be presented. The yoke has been optimized to reduce iron saturation effects on the field harmonics. We shall present the summary of this design which will include the expected overall performance of this cross section. 4 refs., 8 figs., 12 tabs.

  3. Coupling MM5 with ISOLSM: Development, testing, and applications

    SciTech Connect

    Riley, W.J.; Cooley, H.S.; He, Y.; Torn, M.S.

    2003-06-10

    Surface water and energy fluxes are tightly coupled with CO2 exchanges between the ecosystem and atmosphere. Other surface-to-atmosphere trace-gas exchanges of interest in climate change research (e.g., N2O, CH4, C18OO, and H218O) are also strongly impacted by surface energy exchanges. Further, land-use change has large effects on the surface energy balance and therefore the exchanges of these trace gases. To investigate these issues at the regional scale we have coupled MM5 (Grell et al. 1995) with ISOLSM (Riley et al. 2002, Riley et al. 2003), a land-surface model based on LSM1 (Bonan 1995).

  4. The Apollo 15 coarse fines (4-10 mm)

    NASA Technical Reports Server (NTRS)

    Ryder, Graham; Sherman, Sarah Bean

    1989-01-01

    A new catalog of the Apollo 15 coarse fines particles is presented. Powell's macroscopic descriptions, resulting from his 1972 particle by particle binocular examination of all of the Apollo 15 4 to 10 mm fines samples, are retained. His groupings are also retained, but petrographic, chemical, and other data from later analyses are incorporated into this catalog to better characterize individual particles and describe the groups. A large number of particles have no characterization beyond that done by Powell. Complete descriptions of the particles and all known references are provided. The catalog is intended for anyone interested in the rock types collected by Dave Scott and Jim Irwin in the Hadley-Appenine region, and particularly for researchers requiring sample allocations.

  5. 120-mm supercondcting quadrupole for interaction regions of hadron colliders

    SciTech Connect

    Zlobin, A.V.; Kashikhin, V.V.; Mokhov, N.V.; Novitski, I.; /Fermilab

    2010-05-01

    Magnetic and mechanical designs of a Nb{sub 3}Sn quadrupole magnet with 120-mm aperture suitable for interaction regions of hadron colliders are presented. The magnet is based on a two-layer shell-type coil and a cold iron yoke. Special spacers made of a low-Z material are implemented in the coil mid-planes to reduce the level of radiation heat deposition and radiation dose in the coil. The quadrupole mechanical structure is based on aluminum collars supported by an iron yoke and a stainless steel skin. Magnet parameters including maximum field gradient and field harmonics, Nb3Sn coil pre-stress and protection at the operating temperatures of 4.5 and 1.9 K are reported. The level and distribution of radiation heat deposition in the coil and other magnet components are discussed.

  6. Quantum Phase Slips in 6 mm Long Niobium Nanowire.

    PubMed

    Zhao, Weiwei; Liu, Xin; Chan, M H W

    2016-02-10

    Transport measurements were made to study the superconducting transition of four 6 mm long niobium nanowires with different cross-sectional dimensions. A low-temperature residual resistance tail measured with an excitation current of 5 nA is found in the thinnest wire down to 50 mK or 7.7% of Tc of Nb. The functional form of the residual resistance is consistent with quantum phase slip (QPS) processes. Resistance measured at high bias excitation current switches among many discrete values that are well below the normal state resistance. These discrete resistance values as a function of temperature fall into several parallel curves all showing QPS-like decay in the low temperature limit similar to that found at low current. The coexistence of QPS-like resistance tails and resistance jumps found in the same wire unifies results from previous experiments where these two distinct sets of evidence for QPS are exclusive of each other. PMID:26788964

  7. A densitometric analysis of commercial 35mm films

    NASA Technical Reports Server (NTRS)

    Hammond, Ernest C., Jr.; Ruffin, Christopher, III

    1989-01-01

    IIaO films have been subjected to various sensitometric tests. The have included thermal and aging effects and reciprocity failure studies. In order to compare the special IIaO film with popular brands of 35 mm films and their possible use in astrophotography, Agfa, Fuji and Kodak print and slide formats, as well as black and white and color formats, were subjected to sensitometric, as well as densitometric analysis. A scanning electron microscope was used to analyze grain structure size, and shape as a function of both speed and brand. Preliminary analysis of the grain structure using an ISI-SS40 scanning electron microscope indicates that the grain sizes for darker densities are much larger than the grain size for lighter densities. Researchers analyze the scanning electron microscope findings of the various grains versus densities as well as enhancement of the grains, using the IP-8500 Digital Image Processor.

  8. A densitometric analysis of commercial 35mm films

    NASA Astrophysics Data System (ADS)

    Hammond, Ernest C., Jr.; Ruffin, Christopher, III

    IIaO films have been subjected to various sensitometric tests. The have included thermal and aging effects and reciprocity failure studies. In order to compare the special IIaO film with popular brands of 35 mm films and their possible use in astrophotography, Agfa, Fuji and Kodak print and slide formats, as well as black and white and color formats, were subjected to sensitometric, as well as densitometric analysis. A scanning electron microscope was used to analyze grain structure size, and shape as a function of both speed and brand. Preliminary analysis of the grain structure using an ISI-SS40 scanning electron microscope indicates that the grain sizes for darker densities are much larger than the grain size for lighter densities. Researchers analyze the scanning electron microscope findings of the various grains versus densities as well as enhancement of the grains, using the IP-8500 Digital Image Processor.

  9. Calibration of a HTS Based LOX 400 mm Level Sensor

    NASA Astrophysics Data System (ADS)

    Karunanithi, R.; Jacob, S.; Nadig, D. S.; Prasad, M. V. N.; Gour, Abhay S.; Pankaj, S.; Gowthaman, M.; Sudharshan, H.

    The measurement of the cryogen level in a cryostage of space crafts is crucial. At the same time the weight of the sensor should be small as it affects the payload fraction of the space craft. An attempt to develop a HTS based level sensor of 400 mm for Liquid Oxygen (LOX) measurement was made. In the initial phase of testing, loss of superconductivity of HTS wire in LOX inside a cryostat was noticed. Thus, a new four wall cryostat was designed to have a stable LOX level to provide thermal stability to the HTS based LOX sensor. The calibration of the developed sensor was carried out against capacitance level sensor which was pre calibrated using diode array to verify its linearity and performance for different current excitation levels. The calibrations were carried out without heater wires. The automatic data logging was accomplished using a program developed in LabVIEW 11.0.

  10. Generation of mm- and Sub mm-wave Bessel Beams Using DOE's Designed by BOR-FDTD Method and MGA

    NASA Astrophysics Data System (ADS)

    Yu, Y. Z.; Dou, W. B.

    2009-02-01

    A new way for generating Bessel beams at mm and sub mm-wavelengths is presented in this paper, in which diffractive optical elements (DOE’s) are designed for converting incident Gaussian beams into Bessel beams. In order to reduce the computational burden and therefore improve the design efficiency, two measures are adopted in our design. One is a body-of-revolution finite-difference time-domain (BOR-FDTD) method that uses a two-dimensional (2-D) solution space instead of a full 3-D space and thereby saves tremendous computational resources, and that is utilized to calculate the fields diffracted by the DOE’s. The other is a microgenetic algorithm (MGA) that has been proved to be more effective than the conventional GA, and that is employed for accelerative optimization. The utility of the present design tool, which combines a MGA with a BOR-FDTD method, is demonstrated by three examples. Numerical simulation results indicate that the designed DOE’s can not only flexibly generate zero- or higher- order Bessel beams when compared with axicons, but also have higher diffraction efficiencies when compared with amplitude holograms.

  11. Comparison of less lethal 40 mm sponge projectile and the 37 mm projectile for injury assessment on human thorax

    NASA Astrophysics Data System (ADS)

    Nsiampa, N.; Robbe, C.; Oukara, A.; Papy, A.

    2012-08-01

    Since there is an increasing interest in avoiding human body injury in diverse situations like crowd control or peacekeeping missions, less lethal ammunition are more and more used. In this study we focus only on kinetic energy non-lethal (KENLW) projectiles. Their desired effects on human body are the temporary incapacitation through blunt trauma. There are different types of KENLW projectiles ranging from rigid to deformable projectiles. Unfortunately, the effects of such projectiles are not really well known as it is difficult to measure the force transmitted to the human body or the related deformation. Because the potential of injury excludes human living tests, tests are performed on cadavers, animals or human tissue surrogates. Besides these tests, numerical simulations are more and more used to gain more understanding, to assess or to predict the effects of this kind of projectile on human body. In this paper a comparison based on the viscous criterion between the 37 mm rigid projectile and the 40 mm sponge projectile was made.

  12. Modelling and performance of Nb SIS mixers in the 1.3 mm and 0.8 mm bands

    NASA Technical Reports Server (NTRS)

    Karpov, A.; Carter, M.; Lazareff, B.; Billon-Pierron, D.; Gundlach, K. H.

    1992-01-01

    We describe the modeling and subsequent improvements of SIS waveguide mixers for the 200-270 and 330-370 GHz bands (Blundell, Carter, and Gundlach 1988, Carter et al 1991). These mixers are constructed for use in receivers on IRAM radiotelescopes on Pico Veleta (Spain, Sierra Nevada) and Plateau de Bure (French Alps), and must meet specific requirements. The standard reduced height waveguide structure with suspended stripline is first analyzed and a model is validated through comparison with scale model and working scale measurements. In the first step, the intrinsic limitations of the standard mixer structure are identified, and the parameters are optimized bearing in mind the radioastronomical applications. In the second step, inductive tuning of the junctions is introduced and optimized for minimum noise and maximum bandwidth. In the 1.3 mm band, a DSB receiver temperature of less than 110 K (minimum 80 K) is measured from 180 through 260 GHz. In the 0.8 mm band, a DSB receiver temperature of less than 250 K (minimum 175 K) is obtained between 325 and 355 GHz. All these results are obtained with room-temperature optics and a 4 GHz IF chain having a 500 MHz bandwidth and a noise temperature of 14 K.

  13. Error Growth Rate in the MM5 Model

    NASA Astrophysics Data System (ADS)

    Ivanov, S.; Palamarchuk, J.

    2006-12-01

    The goal of this work is to estimate model error growth rates in simulations of the atmospheric circulation by the MM5 model all the way from the short range to the medium range and beyond. The major topics are addressed to: (i) search the optimal set of parameterization schemes; (ii) evaluate the spatial structure and scales of the model error for various atmospheric fields; (iii) determine geographical regions where model errors are largest; (iv) define particular atmospheric patterns contributing to the fast and significant model error growth. Results are presented for geopotential, temperature, relative humidity and horizontal wind components fields on standard surfaces over the Atlantic-European region during winter 2002. Various combinations of parameterization schemes for cumulus, PBL, moisture and radiation are used to identify which one provides a lesser difference between the model state and analysis. The comparison of the model fields is carried out versus ERA-40 reanalysis of the ECMWF. Results show that the rate, at which the model error grows as well as its magnitude, varies depending on the forecast range, atmospheric variable and level. The typical spatial scale and structure of the model error also depends on the particular atmospheric variable. The distribution of the model error over the domain can be separated in two parts: the steady and transient. The first part is associated with a few high mountain regions including Greenland, where model error is larger. The transient model error mainly moves along with areas of high gradients in the atmospheric flow. Acknowledgement: This study has been supported by NATO Science for Peace grant #981044. The MM5 modelling system used in this study has been provided by UCAR. ERA-40 re-analysis data have been obtained from the ECMWF data server.

  14. 300mm pilot line DSA contact hole process stability

    NASA Astrophysics Data System (ADS)

    Argoud, M.; Servin, I.; Gharbi, A.; Pimenta Barros, P.; Jullian, K.; Sanche, M.; Chamiot-Maitral, G.; Barnola, S.; Tiron, R.; Navarro, C.; Chevalier, X.; Nicolet, C.; Fleury, G.; Hadziioannou, G.; Asai, M.; Pieczulewski, C.

    2014-03-01

    Directed Self-Assembly (DSA) is today a credible alternative lithographic technology for semiconductor industry [1]. In the coming years, DSA integration could be a standard complementary step with other lithographic techniques (193nm immersion, e-beam, extreme ultraviolet). Its main advantages are a high pattern resolution (down to 10nm), a capability to decrease an initial pattern edge roughness [2], an absorption of pattern guide size variation, no requirement of a high-resolution mask and can use standard fab-equipment (tracks and etch tools). The potential of DSA must next be confirmed viable for high volume manufacturing. Developments are necessary to transfer this technology on 300mm wafers in order to demonstrate semiconductor fab-compatibility [3-7]. The challenges concern especially the stability, both uniformity and defectivity, of the entire process, including tools and Blok Co-Polymer (BCP) materials. To investigate the DSA process stability, a 300mm pilot line with DSA dedicated track (SOKUDO DUO) is used at CEALeti. BCP morphologies with PMMA cylinders in a PS matrix are investigated (about 35nm natural period). BCP selfassembly in unpatterned surface and patterned surface (graphoepitaxy) configurations are considered in this study. Unpatterned configuration will initially be used for process optimization and fix a process of record. Secondly, this process of record will be monitored with a follow-up in order to validate its stability. Steps optimization will be applied to patterned surface configurations (graphoepitaxy) for contact hole patterning application. A process window of contact hole shrink process will be defined. Process stability (CD uniformity and defectivity related to BCP lithography) will be investigated.

  15. MALT-45: The Galactic plane in 7mm

    NASA Astrophysics Data System (ADS)

    Jordan, Christopher; Walsh, Andrew; Voronkov, Maxim; Ellingsen, Simon

    2013-07-01

    MALT-45: The Galactic plane in 7mm MALT-45 is an untargeted Galactic plane survey searching for tracers of high mass star formation (HMSF) at 7mm. With the recent upgrades to the Australia Telescope Compact Array, we have been able to push the limits on observational efficiency to obtain a very sensitive blind survey in a short amount of time. Specifically, MALT-45 uses a fast on-the-fly mapping with 6 seconds per pointing, which results in a quarter-square-degree region being mapped in approximately 14 hours. Each region is Nyquist sampled and collects data in 12 spectral lines. The primary spectral lines of MALT-45 include: CS (1-0) - a high density gas tracer, which contrasts well with NH3 (1,1) from the similar HOPS survey; 44 GHz Class I methanol masers - the brightest of the Class I lines, it is poorly understood, and MALT-45 is one of the first surveys to thoroughly search for these masers; SiO (1-0) v=1,2,3 - typically associated with evolved stars, there have been rare associations with HMSF, and MALT-45 offers the potential to detect more. Other lines include thermal SiO (1-0) v=0, thermal methanol, C34S, OCS, and radio recombination lines H51a and H53a. Perhaps the most significant and innovative aspect of MALT-45 is the usage of ATCA autocorrelations. Each antenna of the ATCA is similar to Mopra, and by using all 6 antennae simultaneously, have a 6 fold increase in sensitivity per unit observation time. The autocorrelation data was only recently made available by the ATCA upgrade with the Compact Array Broadband Backend, and tools have been developed to allow this data processing. We present the first 5 square-degrees (l = 330 - 335, b = -0.5 - +0.5) of the Galactic plane mapped by MALT-45.

  16. Sulforaphane Protects Rodent Retinas against Ischemia-Reperfusion Injury through the Activation of the Nrf2/HO-1 Antioxidant Pathway

    PubMed Central

    Liu, Ruixing; Brecha, Nicholas C.; Yu, Albert Cheung Hoi; Pu, Mingliang

    2014-01-01

    Retinal ischemia-reperfusion (I/R) injury induces oxidative stress, leukocyte infiltration, and neuronal cell death. Sulforaphane (SF), which can be obtained in cruciferous vegetables such as broccoli, exerts protective effects in response to oxidative stress in various tissues. These effects can be initiated through nuclear factor E2-related factor 2 (Nrf2)-mediated induction of heme oxygenase-1 (HO-1). This investigation was designed to elucidate the neural protective mechanisms of SF in the retinal I/R rat model. Animals were intraperitoneally (i.p.) injected with SF (12.5 mg/kg) or vehicle (corn oil) once a day for 7 consecutive days. Then, retinal I/R was made by elevating the intraocular pressure (IOP) to 130 mmHg for 1 h. To determine if HO-1 was involved in the Nrf2 antioxidant pathway, rats were subjected to protoporphyrin IX zinc (II) (ZnPP, 30 mg/kg, i.p.) treatments at 24 h before retinal ischemia. The neuroprotective effects of SF were assessed by determining the morphology of the retina, counting the infiltrating inflammatory cells and the surviving retinal ganglion cells (RGCs) and amacrine cells, and measuring apoptosis in the retinal layers. The expression of Nrf2 and HO-1 was studied by immunofluorescence analysis and western blotting. I/R induced a marked increase of ROS generation, caused pronounced inflammation, increased the apoptosis of RGCs and amacrine cells and caused the thinning of the inner retinal layer (IRL), and these effects were diminished or abolished by SF pretreatment. Meanwhile, SF pretreatment significantly elevated the nuclear accumulation of Nrf2 and the level of HO-1 expression in the I/R retinas; however, ZnPP reversed the protective effects of SF on I/R retinas. Together, we offer direct evidence that SF had protective effects on I/R retinas, which could be attributed, at least in part, to the activation of the Nrf2/HO-1 antioxidant pathway. PMID:25470382

  17. Pregnancy-associated adaptations in [Ca2+]i-dependent and Ca2+ sensitization mechanisms of venous contraction: implications in pregnancy-related venous disorders.

    PubMed

    Xia, Yin; Khalil, Raouf A

    2016-06-01

    Pregnancy is associated with significant adaptations in the maternal hemodynamics and arterial circulation, but the changes in the venous mechanisms during pregnancy are less clear. We hypothesized that pregnancy is associated with alterations in venous function, intracellular free Ca(2+) concentration ([Ca(2+)]i), and Ca(2+)-dependent mechanisms of venous contraction. Circular segments of inferior vena cava (IVC) from virgin and late pregnant (Preg, day 19) Sprague-Dawley rats were suspended between two hooks, labeled with fura-2, and placed in a cuvet inside a spectrofluorometer for simultaneous measurement of contraction and [Ca(2+)]i (fura-2 340/380 ratio). KCl (96 mM), which stimulates Ca(2+) influx, caused less contraction (35.6 ± 6.3 vs. 92.6 ± 19.9 mg/mg tissue) and smaller increases in [Ca(2+)]i (1.67 ± 0.12 vs. 2.19 ± 0.11) in Preg vs. virgin rat IVC. The α-adrenergic receptor agonist phenylephrine (Phe; 10(-5) M) caused less contraction (23.8 ± 3.4 vs. 70.9 ± 12.9 mg/mg tissue) and comparable increases in [Ca(2+)]i (1.76 ± 0.10 vs. 1.89 ± 0.08) in Preg vs. virgin rat IVC. At increasing extracellular Ca(2+) concentrations ([Ca(2+)]e) (0.1, 0.3, 0.6, 1, and 2.5 mM), KCl and Phe induced [Ca(2+)]e-contraction and [Ca(2+)]e-[Ca(2+)]i curves that were reduced in Preg vs. virgin IVC, supporting reduced Ca(2+) entry mechanisms. The [Ca(2+)]e-contraction and [Ca(2+)]e-[Ca(2+)]i curves were used to construct the [Ca(2+)]i-contraction relationship. Despite reduced contraction and [Ca(2+)]i in Preg IVC, the Phe-induced [Ca(2+)]i-contraction relationship was greater than that of KCl and was enhanced in Preg vs. virgin IVC, suggesting parallel activation of Ca(2+)-sensitization pathways. The Ca(2+) channel blocker diltiazem, protein kinase C (PKC) inhibitor GF-109203X, and Rho-kinase (ROCK) inhibitor Y27632 inhibited KCl- and Phe-induced contraction and abolished the shift in the Phe [Ca(2+)]i-contraction relationship in Preg IVC, suggesting an interplay

  18. Modulation of intracellular calcium waves and triggered activities by mitochondrial ca flux in mouse cardiomyocytes.

    PubMed

    Zhao, Zhenghang; Gordan, Richard; Wen, Hairuo; Fefelova, Nadezhda; Zang, Wei-Jin; Xie, Lai-Hua

    2013-01-01

    Recent studies have suggested that mitochondria may play important roles in the Ca(2+) homeostasis of cardiac myocytes. However, it is still unclear if mitochondrial Ca(2+) flux can regulate the generation of Ca(2+) waves (CaWs) and triggered activities in cardiac myocytes. In the present study, intracellular/cytosolic Ca(2+) (Cai (2+)) was imaged in Fluo-4-AM loaded mouse ventricular myocytes. Spontaneous sarcoplasmic reticulum (SR) Ca(2+) release and CaWs were induced in the presence of high (4 mM) external Ca(2+) (Cao (2+)). The protonophore carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (FCCP) reversibly raised basal Cai (2+) levels even after depletion of SR Ca(2+) in the absence of Cao (2+) , suggesting Ca(2+) release from mitochondria. FCCP at 0.01 - 0.1 µM partially depolarized the mitochondrial membrane potential (Δψ m ) and increased the frequency and amplitude of CaWs in a dose-dependent manner. Simultaneous recording of cell membrane potentials showed the augmentation of delayed afterdepolarization amplitudes and frequencies, and induction of triggered action potentials. The effect of FCCP on CaWs was mimicked by antimycin A (an electron transport chain inhibitor disrupting Δψ m ) or Ru360 (a mitochondrial Ca(2+) uniporter inhibitor), but not by oligomycin (an ATP synthase inhibitor) or iodoacetic acid (a glycolytic inhibitor), excluding the contribution of intracellular ATP levels. The effects of FCCP on CaWs were counteracted by the mitochondrial permeability transition pore blocker cyclosporine A, or the mitochondrial Ca(2+) uniporter activator kaempferol. Our results suggest that mitochondrial Ca(2+) release and uptake exquisitely control the local Ca(2+) level in the micro-domain near SR ryanodine receptors and play an important role in regulation of intracellular CaWs and arrhythmogenesis. PMID:24348912

  19. Powder Neutron Diffraction Study of HoCoGa5

    SciTech Connect

    Kabayashi, Riki; Kaneko, Koji; Wakimoto, Shuichi; Chi, Songxue; Sanada, Naoyuki; Watanuki, Ryuta; Suzuki, Kazuya

    2013-01-01

    We have studied successive magnetic transitions of HoCoGa5 at TN1 = 9.6 K and TN2 = 7.5 K by using powder neutron diffraction. Apparent superlattice peaks were observed at temperatures below TN1. With further decreases temperature, the patterns exhibit a substantial change at temperatures below TN2. The observed magnetic peaks at 8 K (AntiFerromagnetic InCommensurate (AFIC) phase : TN2 < T < TN1) can be represented by the propagation vector qL = (1/2 0 ) with = 0.35(2). In contrast, the magnetic structure becomes commensurate with qC = (1/2 0 1/2) at 4 K (AntiFerromagnetic Commensurate (AFC) phase : T < TN2). The temperature dependence of magnetic intensity shows an apparent temperature hysteresis at TN2, indicates a first-order transition at TN2. Analysis of the integrated intensity at 4 K reveals that the Ho moment with a size of 8.6(2) B, oriented parallel to the c-axis in the AFC phase. While the successive transitions of HoCoGa5 are different from those of TbCoGa5, the magnetic structure in the AFC phase of HoCoGa5 is the same as the AFTb I of TbCoGa5, and may indicate an additional transition at a lower temperature in HoCoGa5.

  20. Infrared spectra of products of the reaction of H atoms with O2 trapped in solid neon: HO2, HO2(+), HOHOH(-), and H2O(HO).

    PubMed

    Jacox, Marilyn E; Thompson, Warren E

    2013-10-01

    When a Ne/O2 mixture is codeposited at 4.3 K with a Ne/H2 mixture that has been passed through a microwave discharge, the infrared spectrum of the resulting deposit includes prominent absorptions of the three vibrational fundamentals of HO2 and seven relatively weak absorptions in the infrared and near-infrared, only one of them previously reported, that can be assigned to overtones and combination bands of that product. Similar assignments are made for DO2. A new, broad absorption at 702.9 cm(-1) appears close to the gas-phase absorption of HOHOH(-) at 697 cm(-1). Isotopic substitution experiments support that assignment. Evidence is also presented for the stabilization of HOHO(-). Absorptions near the vibrational fundamentals of H2O and an absorption at 3472.4 cm(-1) grow on exposure of the deposit to radiation of wavelength shorter than 345 nm. These absorptions are assigned to the H2O(HO) complex, in agreement with the results of an earlier argon-matrix study. In both studies, photodestruction of HO2 molecules that have H2O trapped in a nearby site results in formation of the complex. Because the discharge through Ne/H2 supports ion production, photodetachment of the resulting HOHOH(-) is an additional source of the complex. Other absorptions may be contributed by the bending fundamental of HO2(+) and by a cation complex with H2. PMID:23215001

  1. Diversity of atrial local Ca2+ signalling: evidence from 2-D confocal imaging in Ca2+-buffered rat atrial myocytes.

    PubMed

    Woo, Sun-Hee; Cleemann, Lars; Morad, Martin

    2005-09-15

    significantly dampened at the central sites. On the other hand, the gains of peripheral and central Ca(2+) releases in group 2 cells showed no voltage dependence. Surprisingly, the voltage dependence of the fast central release component was bell-shaped and similar to that of I(Ca) in both cell groups. Removal of extracellular Ca(2+) or application of Ni(2+) (5 mM) suppressed equally I(Ca) and Ca(2+) release from the central release sites at +60 mV. Depolarization to +100 mV, where I(Ca) is absent and the Na(+)-Ca(2+) exchanger (NCX) acts in reverse mode, did not trigger the fast central Ca(2+) releases in either group, but brief reduction of [Na(+)](o) to levels equivalent to [Na(+)](i) facilitated fast peripheral and central Ca(2+) releases in group 2 myocytes, but not in group 1 myocytes. In group 2 cells, long-lasting (> 1 min) exposures to caffeine (10 mM) or ryanodine (20 microM) significantly suppressed I(Ca)-triggered central and peripheral Ca(2+) releases. Our data suggest significant diversity of local Ca(2+) signalling in rat atrial myocytes. In one group, I(Ca)-triggered peripheral Ca(2+) release propagates into the interior triggering central Ca(2+) release with significant delay. In a second group of myocytes I(Ca) triggers a significant number of central sites as rapidly and effectively as the peripheral sites, thereby producing more synchronized Ca(2+) releases throughout the myocytes. The possible presence of vestigial t-tubules and larger Ca(2+) content of central sarcoplasmic reticulum (SR) in group 2 cells may be responsible for the rapid and strong activation of central release of Ca(2+) in this subset of atrial myocytes. PMID:16020459

  2. Identification and apical membrane localization of an electrogenic Na+/Ca2+ exchanger NCX2a likely to be involved in renal Ca2+ excretion by seawater fish

    PubMed Central

    Islam, Zinia; Romero, Michael F.; Hirose, Shigehisa

    2011-01-01

    Seawater (SW) contains ∼10 mM Ca2+, yet marine fish must drink seawater as their major water source. Thus marine teleosts fish need to excrete Ca2+ to maintain whole body Ca2+ homeostasis. In the intestine, seawater Ca2+ interreacts with epithelial-secreted HCO3− by the intestinal epithelium, and the resulting CaCO3 precipitates, which is rectally excreted. Recently the transporters involved in intestinal HCO3− secretion were identified. Ca2+ is also excreted by the kidney, but the protein(s) involved in renal Ca2+ excretion have not been identified. Here we identified a candidate transporter by using SW pufferfish torafugu (Takifugu rubripes) and its closely related euryhaline species mefugu (Takifugu obscurus), which are becoming useful animal models for studying molecular mechanisms of seawater adaptation. RT-PCR analyses of Na+/Ca2+ exchanger (NCX) family members in various torafugu tissues demonstrated that only NCX2a is highly expressed in the kidney. Renal expression of NCX2a was markedly elevated when mefugu were transferred from freshwater to seawater. In situ hybridization and immunohistochemical analyses indicated that NCX2a is expressed in the proximal tubule at the apical membrane. NCX2a, expressed in Xenopus oocytes, conferred [Ca2+]out- and Na+-dependent currents. These results suggest that NCX2a mediates renal Ca2+ secretion at the apical membrane of renal proximal tubules and has an important role in whole body Ca2+ homeostasis of marine teleosts. PMID:21880864

  3. Intracellular calcium and Na+-Ca2+ exchange current in isolated toad pacemaker cells

    PubMed Central

    Ju, Yue-Kun; Allen, David G

    1998-01-01

    Single pacemaker cells were isolated from the sinus venosus of cane toad (Bufo marinus) in order to study the mechanisms involved in the spontaneous firing rate of action potentials. Intracellular calcium concentration ([Ca2+]i) was measured with indo-1 to determine whether [Ca2+]i influenced firing rate. A rapid transient rise of [Ca2+]i was recorded together with each spontaneous action potential. [Ca2+]i at the peak of systole was 655 ± 64 nm and the minimum at the end of diastole was 195 ± 15 nm. Reduction of extracellular Ca2+ concentration from 2 to 0.5 mm caused a reduction in both systolic and diastolic [Ca2+]i and the spontaneous firing rate also gradually declined. Application of the acetoxymethyl (AM) ester of BAPTA (10 μm), in order to increase intracellular calcium buffering, caused a decline in systolic and diastolic [Ca2+]i. The firing rate declined progressively until the cells stopped firing after 10–15 min. At the time that firing ceased, the diastolic [Ca2+]i had declined by 141 ± 38 nm. In the presence of ryanodine (2 μm), which interferes with Ca2+ release from the sarcoplasmic reticulum, the systolic and diastolic [Ca2+]i both declined and the firing rate decreased until the cells stopped firing. At quiescence diastolic [Ca2+]i had declined by 93 ± 20 nm. Exposure of the cells to Na+-free solution caused a rise in [Ca2+]i which exceeded the systolic level after 4.8 ± 0.3 s. This rise is consistent with Ca2+ entry on a Na+-Ca2+ exchanger. Rapid application of caffeine (10–20 mm) to cells clamped at −60 mV caused a rapid increase in [Ca2+]i which then spontaneously declined. An inward current with a similar time course to that of [Ca2+]i was also generated. Application of Ni2+ (5 mm) or 2,4-dichlorobenzamil (25 μm) reduced the amplitude of the inward current produced by caffeine by 96 ± 1 % and 74 ± 10 %, respectively. In a Na+-free solution the caffeine-induced current was reduced by 93 ± 7 %. Under a variety of circumstances

  4. Intracellular BK(Ca) (iBK(Ca)) channels.

    PubMed

    Singh, Harpreet; Stefani, Enrico; Toro, Ligia

    2012-12-01

    The large conductance calcium- and voltage-activated potassium channel (BK(Ca)) is widely expressed at the plasma membrane. This channel is involved in a variety of fundamental cellular functions including excitability, smooth muscle contractility, and Ca(2+) homeostasis, as well as in pathological situations like proinflammatory responses in rheumatoid arthritis, and cancer cell proliferation. Immunochemical, biochemical and pharmacological studies from over a decade have intermittently shown the presence of BK(Ca) in intracellular organelles. To date, intracellular BK(Ca) (iBK(Ca)) has been localized in the mitochondria, endoplasmic reticulum, nucleus and Golgi apparatus but its functional role remains largely unknown except for the mitochondrial BK(Ca) whose opening is thought to play a role in protecting the heart from ischaemic injury. In the nucleus, pharmacology suggests a role in regulating nuclear Ca(2+), membrane potential and eNOS expression. Establishing the molecular correlates of iBK(Ca), the mechanisms defining iBK(Ca) organelle-specific targeting, and their modulation are challenging questions. This review summarizes iBK(Ca) channels, their possible functions, and efforts to identify their molecular correlates. PMID:22930268

  5. Cardiac Ca2+ signaling and Ca2+ sensitizers.

    PubMed

    Endoh, Masao

    2008-12-01

    The role of Ca2+ in cardiac excitation-contraction (E-C) coupling has been established by simultaneous measurements of contractility and Ca2+ transients by means of aequorin in intact myocardium and Ca2+ sensitive fluorescent dyes in single myocytes. The E-C coupling process can be classified into 3 processes: upstream (Ca2+ mobilization), central (Ca2+ binding to troponin C) and downstream mechanism (thin filament regulation and crossbridge cycling). These mechanisms are regulated differentially by various inotropic interventions. Positive force-frequency relationship and effects of beta-adrenoceptor stimulation, phosphodiesterase 3 inhibitors and digitalis are essentially exerted via upstream mechanism. Alpha-adrenoceptor stimulation, endothelin-1, angiotensin II, and clinically available Ca2+ sensitizers, such as levosimendan and pimobendan, act by a combination of the upstream and central/downstream mechanism. The Frank-Starling mechanism and effects of Ca2+ sensitizers such as EMD 57033 and Org 30029 are primarily induced via the central/downstream mechanism. Whereas the upstream and central mechanisms are markedly suppressed in failing myocytes and under acidotic conditions, Ca2+ sensitizers such as EMD 57033 and Org 30029 can induce cardiotonic effects under such conditions. Ca2+ sensitizers have high therapeutic potential for the treatment of contractile dysfunction in congestive heart failure and ischemic heart diseases, because they have energetic advantages and less risk of Ca2+ overload and can maintain effectiveness under pathological conditions. PMID:18981594

  6. GDx-MM: An imaging Mueller matrix retinal polarimeter

    NASA Astrophysics Data System (ADS)

    Twietmeyer, Karen Marie

    2007-12-01

    Retinal diseases are a major cause of blindness worldwide. Although widely studied, disease mechanisms are not completely understood, and diagnostic tests may not detect disease early enough for timely intervention. The goal of this research is to contribute to research for more sensitive diagnostic tests that might use the interaction of polarized light with retinal tissue to detect subtle changes in the microstructure. This dissertation describes the GDx-MM, a scanning laser polarimeter which measures a complete 16-element Mueller matrix image of the retina. This full polarization signature may provide new comparative information on the structure of healthy and diseased retinal tissue by highlighting depolarizing structures as well as structures with varying magnitudes and orientations of retardance and diattenuation. The three major components of this dissertation are: (1) Development of methods for polarimeter optimization and error analysis; (2) Design, optimization, assembly, calibration, and validation of the GDx-MM polarimeter; and (3) Analysis of data for several human subjects. Development involved modifications to a Laser Diagnostics GDx, a commercially available scanning laser ophthalmoscope with incomplete polarization capability. Modifications included installation of polarization components, development of a data acquisition system, and implementation of algorithms to convert raw data into polarization parameter images. Optimization involved visualization of polarimeter state trajectories on the Poincare sphere and a condition number analysis of the instrument matrix. Retinal images are collected non-invasively at 20 mum resolution over a 15° visual field in four seconds. Validation of the polarimeter demonstrates a polarimetric measurement accuracy of approximately +/- 5%. Retinal polarization data was collected on normal human subjects at the University of Arizona and at Indiana University School of Optometry. Calculated polarization parameter

  7. Improved mm-wave photometry for kinetic inductance detectors

    NASA Astrophysics Data System (ADS)

    Calvo, M.; Roesch, M.; Désert, F.-X.; Monfardini, A.; Benoit, A.; Mauskopf, P.; Ade, P.; Boudou, N.; Bourrion, O.; Camus, P.; Cruciani, A.; Doyle, S.; Hoffmann, C.; Leclercq, S.; Macias-Perez, J. F.; Ponthieu, N.; Schuster, K. F.; Tucker, C.; Vescovi, C.

    2013-03-01

    Context. We have developed a dual-band (140 and 220 GHz) mm-wave imaging camera based on superconducting kinetic inductance detector (KID) arrays. Each array contains 132 superconducting resonators whose resonant frequencies are shifted by mm-wave photons absorption. The read out is achieved with a single electronics chain per band, taking advantage of the intrinsic KID frequency-domain multiplexability. The arrays are easily scalable and well adapted for future large format focal plane instruments. NIKA (formerly Néel IRAM KID Array, now New IRAM KID Array) has been specifically designed for the IRAM 30 m telescope at Pico Veleta, and is one of the first instruments using KIDs to have made measurements of astronomical sources. Aims: In this Letter we describe the solutions adopted to improve the calibration accuracy and the sensitivity of the instrument, and we report on the outcome of the 3rd NIKA observing run of October, 2011. Methods: We use a fast electronic modulation of the readout tone for each KID pixel in order to linearize the instrument calibration, which we track with measurements of planets. We also adopt a new design of the KIDs, sensitive to both polarizations, to increase the amount of radiation absorbed and thus the optical efficiency of the system. Results: We measured an average sensitivity on the sky of 21 mJys0.5 per beam at 140 GHz and 140 mJys0.5 at 220 GHz in the best observing conditions (τ220 ≃ 0.2) after atmospheric noise decorrelation. The sensitivity at 220 GHz was limited by the atmospheric attenuation and loading as well as a reduction in the spectral bandwidth due to a misplaced filter. We found the repeatability in the photometry over the entire observing run to be better than 10% in both bands, thus demonstrating a significant improvement over the previous runs. We also find good agreement between NIKA measurements of faint astronomical sources and previous measurements of the same sources.

  8. Activation of Ca2+-activated Cl- current by depolarizing steps in rabbit urethral interstitial cells.

    PubMed

    Hollywood, M A; Sergeant, G P; McHale, N G; Thornbury, K D

    2003-08-01

    Interstitial cells were isolated from strips of rabbit urethra for study using the amphotericin B perforated-patch technique. Depolarizing steps to -30 mV or greater activated a Ca2+ current (ICa), followed by a Ca2+-activated Cl- current, and, on stepping back to -80 mV, large Cl- tail currents were observed. Both currents were abolished when the cells were superfused with Ca2+-free bath solution, suggesting that Ca2+ influx was necessary for activation of the Cl- current. The Cl- current was also abolished when Ba2+ was substituted for Ca2+ in the bath or the cell was dialyzed with EGTA (2 mM). The Cl- current was also reduced by cyclopiazonic acid, ryanodine, 2-aminoethoxydiphenyl borate (2-APB), and xestospongin C, suggesting that Ca2+-induced Ca2+ release (CICR) involving both ryanodine and inositol 1,4,5-trisphosphate receptors contributes to its activation. PMID:12672653

  9. Effect of somatostatin on 45Ca fluxes in guinea-pig isolated atria.

    PubMed Central

    Díez, J.; Tamargo, J.

    1987-01-01

    The effect of somatostatin (SS, 10(-6) M and 5 X 10(-6) M) was studied on 45Ca fluxes in guinea-pig isolated atria. SS produced a dose-dependent decrease in 45Ca uptake, this effect being dependent on the stimulation rate and Ca concentration in the bathing media. The decrease in 45Ca uptake was more evident at faster (60 and 180 beats min-1) than at slower frequencies (15 beats min-1) and was less evident in high Ca (5.4 mM). SS had no effect on 45Ca efflux. These results suggest that SS inhibits the slow inward Ca current in guinea-pig atrial fibres. PMID:2435352

  10. Shear fluid-induced Ca2+ release and the role of mitochondria in rat cardiac myocytes.

    PubMed

    Belmonte, Steve; Morad, Martin

    2008-03-01

    Cardiac myocyte contraction occurs when Ca2+ influx through voltage-gated L-type Ca2+ channels causes Ca2+ release from ryanodine receptors of the sarcoplasmic reticulum (SR). Although mitochondria occupy about 35% of the cell volume in rat cardiac myocytes, and are thought to be located <300 nm from the junctional SR, their role in the beat-to-beat regulation of cardiac Ca2+ signaling remains unclear. We have recently shown that rapid ( approximately 20 ms) application of shear fluid forces ( approximately 25 dynes/cm2) to rat cardiac myocytes triggers slowly ( approximately 300 ms) developing Cai transients that were independent of activation of all transmembrane Ca2+ transporting pathways, but were suppressed by FCCP, CCCP, and Ru360, all of which are known to disrupt mitochondrial function. We have here used rapid 2-D confocal microscopy to monitor fluctuations in mitochondrial Ca2+ levels ([Ca2+]m) and mitochondrial membrane potential (Delta Psi m) in rat cardiac myocytes loaded either with rhod-2 AM or tetramethylrhodamine methyl ester (TMRM), respectively. Freshly isolated intact rat cardiac myocytes were plated on glass coverslips and incubated in 5 mM Ca2+ containing Tyrode's solution and 40 mM 2,3-butanedione monoxime (BDM) to inhibit cell contraction. Alternatively, myocytes were permeabilized with 10 microM digitonin and perfused with an "intracellular" solution containing 10 microM free [Ca2+], 5 mM EGTA, and 15 mM BDM. Direct [Ca2+]m measurements showed transient mitochondrial Ca2+ accumulation after exposure to 10 mM caffeine, as revealed by a 66% increase in the rhod-2 fluorescence intensity. Shear fluid forces, however, produced a 12% decrease in signal, suggesting that application of a mechanical force releases Ca2+ from the mitochondria. In addition, caffeine and CCCP or FCCP strongly reduced Delta Psi m, while application of a pressurized solution produced a transient Delta Psi m hyperpolarization in intact ventricular myocytes loaded with TMRM

  11. Visualization of 2-μm radiation by BiF3:Ho3+ and BiF3:Ho3+/Yb3+ ceramics

    NASA Astrophysics Data System (ADS)

    Savikin, A. P.; Egorov, A. S.; Budruev, A. V.; Grishin, I. A.

    2016-06-01

    A series of ceramic samples of the compositions BiF3:1%Ho3+, BiF3:4%Ho3+, BiF3:1%Ho3+ + 1%Yb3+, and BiF3:1%Ho3+ + 3%Yb3+ is synthesized and the conversion of Tm:YLF laser radiation (λ = 1908 nm) is studied. The luminescence spectra exhibit bands in the regions of 490, 545, and 650 nm. The kinetic measurements of the afterglow of the green and red bands show that the population of the 5 S 2 and 5 F 4 states in the BiF3:1%Ho3+ samples occurs due to successive absorption of excitation photons, while the 5 F 5 level of Ho3+ is populated due to the ion-ion interaction. Codoping with Yb3+ leads to a decrease in the visualization threshold power density to 2 W/cm2.

  12. Proton Radioactivity Measurements at HRIBF: Ho, Lu, and Tm Isotopes

    SciTech Connect

    Akovali, Y.; Batchelder, J.C.; Bingham, C.R.; Davinson, T.; Ginter, T.N.; Gross, C.J.; Grzywacz, R.; Hamilton, J.H.; Janas, Z.; Karny, M.; Kim, S.H.; MacDonald, B.D.; Mas, J.F.; McConnell, J.W.; Piechaczek, A.; Ressler, J.J.; Rykaczewski, K.; Slinger, R.C.; Szerypo, J.; Toth, K.S.; Weintraub, W.; Woods, P.J.; Yu, C.-H.; Zganjar, E.F.

    1998-11-13

    Two new isotopes, {sup 145}Tm and {sup 140}Ho and three isomers in previously known isotopes, {sup 141m}Ho, {sup 150m}Lu and {sup 151m}Lu have been discovered and studied via their decay by proton emission. These proton emitters were produced at the Holifield Radioactive Ion Beam Facility (HRIBF) by heavy-ion fusion-evaporation reactions, separated in A/Q with a recoil mass spectrometer (RMS), and detected in a double-sided silicon strip detector (DSSD). The decay energy and half-life was measured for each new emitter. An analysis in terms of a spherical shell model is applied to the Tm and Lu nuclei, but Ho is considerably deformed and requires a collective model interpretation.

  13. Spectroscopy of {sup 144}Ho using recoil-isomer tagging

    SciTech Connect

    Mason, P. J. R; Cullen, D. M.; Scholey, C.; Greenlees, P. T.; Jakobsson, U.; Jones, P. M.; Julin, R.; Juutinen, S.; Ketelhut, S.; Leino, M.; Nyman, M.; Peura, P.; Puurunen, A.; Rahkila, P.; Ruotsalainen, P.; Sorri, J.; Saren, J.; Uusitalo, J.; Xu, F. R.

    2010-02-15

    Excited states in the proton-unbound odd-odd nucleus {sup 144}Ho have been populated using the {sup 92}Mo({sup 54}Fe,pn){sup 144}Ho reaction and studied using the recoil-isomer-tagging technique. The alignment properties and signature splitting of the rotational band above the I{sup p}i=(8{sup +}){sup 144m}Ho isomer have been analyzed and the isomer confirmed to have a pih{sub 11/2} x nuh{sub 11/2} two-quasiparticle configuration. The configuration-constrained blocking method has been used to calculate the shapes of the ground and isomeric states, which are both predicted to have triaxial nuclear shapes with |gamma|approx =24 deg.

  14. 100 mm dynamic stencils pattern sub-micrometre structures.

    PubMed

    Savu, Veronica; Xie, Shenqi; Brugger, Juergen

    2011-07-01

    Dynamic stencil lithography uses a moving shadow-mask to draw patterns by having directionally evaporated material deposited through the stencil apertures onto the substrate. Sub-micrometre, two-dimensional patterning is demonstrated at full 100 mm wafer scale, with two examples emphasizing this technique's unique features. Structures having a width-modulated height below a certain aperture size are fabricated by moving the stencil according to a two-dimensional trajectory. Variable-period gratings are obtained by translating a row of apertures at different orientations with respect to the row's axis. Despite the long deposition sequences one could envision for a stencil in dynamic mode, the apertures' active life-time in the sub-micrometre domain remains limited by the material's accretion on the membrane, resulting in the eventual clogging of the openings. A novel solution to this problem containing a micro-heater embedded in the membrane is described and its effectiveness in preventing material from clogging the apertures is demonstrated. PMID:21674118

  15. Mapping wetlands on beaver flowages with 35-mm photography

    USGS Publications Warehouse

    Kirby, R.E.

    1976-01-01

    Beaver flowages and associated wetlands on the Chippewa National Forest, north-central Minnesota, were photographed from the ground and from the open side window of a small high-wing monoplane. The 35-mm High Speed Ektachrome transparencies obtained were used to map the cover-type associations visible on the aerial photographs. Nearly vertical aerial photos were rectified by projecting the slides onto a base map consisting ofcontrol points located by plane-table survey. Maps were prepared by tracing the recognizable stands of vegetation in the rectified projection at the desired map scale. Final map scales ranging from 1:260 to 1:571 permitted identification and mapping of 26 cover-type associations on 10 study flowages in 1971. This cover-mapping technique was economical and substituted for detailed ground surveys. Comparative data from 10 flowages were collected serially throughout the entire open-water season. Although developed for analysis of waterfowl habitat, the technique has application to other areas of wildlife management and ecological investigation.

  16. S-I-S mm-wave mixers and detectors

    NASA Astrophysics Data System (ADS)

    Jillie, D. W.; Kroger, H.; Smith, L. N.; Shaw, D. M.

    1983-10-01

    This program is an effort to achieve the ultimate goal of fabricating refractory superconducting S-I-S mixer devices for operation in mm-wave receivers in the quantum mode and in the 8-10 K temperature range. The following progress has been made toward the above goal: (1) development of in-house capability of depositing niobium carbonitride films (Nb (x) N(y) of device quality with transition temperatures to approx. 16 K; (2) development of NbC(x)N(y):aSi:Nb and NbC(x)N(y):Ge:Nb devices of very high quality; (3) fabrication and successful operation of niobium based S-I-S mixer chips; and (4) fabrication and evaluation of aSi and Ge barrier all-NbC(x)N(y) devices. NbC(x)N(y):Ge:Nb devices have been fabricated with chemical vapor deposited (CVD) polycrystalline arsenic-doped germanium barriers. All-Nb-S-I-S mixer chips were fabricated and sent to Goddard Institute for Space Studies to be evaluated. The noise temperature was approx. 60 K and the conversion loss of 5 dB. These results are comparable to Pb alloy junction results. A second-generation mixer was designed by GISS.

  17. The LMT Galaxies' 3 mm Spectroscopic Survey: First Results

    NASA Astrophysics Data System (ADS)

    Rosa González, D.; Schloerb, P.; Vega, O.; Hunt, L.; Narayanan, G.; Calzetti, D.; Yun, M.; Terlevich, E.; Terlevich, R.; Mayya, Y. D.; Chávez, M.; Montaña, A.; Pérez García, A. M.

    2014-09-01

    The molecular phase of the interstellar medium (ISM) in galaxies offers fundamental insight for understanding star-formation processes and how stellar feedback affects the nuclear activity of certain galaxies. We present here Large Millimeter Telescope spectra obtained with the Redshift Search Receiver, a spectrograph that covers simultaneously the 3 mm band from 74 to 111 GHz with a spectral resolution of around 100 km/s. Our selected galaxies, have been detected previously in HCN, and have different degrees of nuclear activity — one normal galaxy (NGC 6946), the starburst prototype (M82) and two %ultraluminous infrared galaxies (ULIRGs, IRAS 17208-0014 and Mrk 231). We plotted our data in the HCO+/HCN vs. HCN/13CO diagnostic diagram finding that NGC 6946 and M82 are located close to other normal galaxies; and that both IRAS 17208-0014 and Mrk 231 are close to the position of the well known ULIRG Arp 220 reported by Snell et al. (2011). We found that in Mrk 231 - a galaxy with a well known active galactic nucleus - the HCO+/HCN ratio is similar to the ratio observed in normal galaxies.

  18. Latest developments with the 400 MM bore Pielstick engine

    SciTech Connect

    Chellini, R.

    1995-06-01

    For over forty years, S.E.M.T. Pielstick has been manufacturing the 400 mm bore, four-stroke, medium-speed PC diesel engine. The evolution has continued up to the present and the latest issue is the PC2-6B design, featuring an output of 615 kW per cylinder. This result was made possible by a multifold, ongoing development program. Experience, gained on the nearly 4000 PC engines built so far for marine and stationary applications, was combined with technological progress in engine design, materials and components. These elements all contribute to make the present engines, not only over three times as powerful, but also more reliable and more economical to run, featuring a lower specific fuel consumption and requiring less maintenance. The 1000 hours endurance test on the three-cylinder experimental engine has allowed tuning of the PC2-6B to the nominal power of 615 kW/cylinder at 500 r/min and verification of safety margins with the engine running at 600 r/min. The same program highlighted the low emission values of the new engine, summarized as: NO{sub x}, < 6 g/kWh; CO, $LS 0.6 g/kWh; HC, < 0.5 g/kWh; and smoke, < 0.15{degree} Bosch.

  19. COSMOG: Cosmology Oriented Sub-mm Modeling of Galactic Foregrounds

    NASA Technical Reports Server (NTRS)

    Kashlinsky, A.; Leisawitz, D.

    2004-01-01

    With upcoming missions in mid- and far-Infrared there is a need for software packages to reliably simulate the planned observations. This would help in both planning the observation and scanning strategy and in developing the concepts of the far-off missions. As this workshop demonstrated, many of the new missions are to be in the far-IR range of the electromagnetic spectrum and at the same time will map the sky with a sub-arcsec angular resolution. We present here a computer package for simulating foreground maps for the planned sub-mm and far-IR missions. such as SPECS. The package allows to study confusion limits and simulate cosmological observations for specified sky location interactively and in real time. Most of the emission at wavelengths long-ward of approximately 50 microns is dominated by Galactic cirrus and Zodiacal dust emission. Stellar emission at these wavelengths is weak and is for now neglected. Cosmological sources (distant and not-so-distant) galaxies for specified cosmologies will be added. Briefly, the steps that the algorithm goes through is described.

  20. Digital Frequency Domain Multiplexer for mm-Wavelength Telescopes

    SciTech Connect

    Spieler, Helmuth G; Dobbs, Matt; Bissonnette, Eric; Spieler, Helmuth G.

    2007-07-23

    An FPGA based digital signal processing (DSP) system for biasing and reading out multiplexed bolometric detectors for mm-wavelength telescopes is presented. This readout system is being deployed for balloon-borne and ground based cosmology experiments with the primary goal of measuring the signature of inflation with the Cosmic Microwave Background Radiation. The system consists of analog superconducting electronics running at 250 mK and 4 K, coupled to digital room temperature backend electronics described here. The digital electronics perform the real time functionality with DSP algorithms implemented in firmware. A soft embedded processor provides all of the slow housekeeping control and communications. Each board in the system synthesizes multi-frequency combs of 8 to 32 carriers in the MHz band to bias the detectors. After the carriers have been modulated with the sky-signal by the detectors, the same boards digitize the comb directly. The carriers are mixed down to base-band and low pass filtered. The signal bandwidth of 0.050Hz-100 Hz places extreme requirements on stability and requires powerful filtering techniques to recover the sky-signal from the MHz carriers.

  1. Parallel implementation, validation, and performance of MM5

    SciTech Connect

    Michalakes, J.; Canfield, T.; Nanjundiah, R.; Hammond, S.; Grell, G.

    1994-12-31

    We describe a parallel implementation of the nonhydrostatic version of the Penn State/NCAR Mesoscale Model, MM5, that includes nesting capabilities. This version of the model can run on many different massively Parallel computers (including a cluster of workstations). The model has been implemented and run on the IBM SP and Intel multiprocessors using a columnwise decomposition that supports irregularly shaped allocations of the problem to processors. This stategy will facilitate dynamic load balancing for improved parallel efficiency and promotes a modular design that simplifies the nesting problem AU data communication for finite differencing, inter-domain exchange of data, and I/O is encapsulated within a parallel library, RSL. Hence, there are no sends or receives in the parallel model itself. The library is Generalizable to other, similar finite difference approximation codes. The code is validated by comparing the rate of growth in error between the sequential and parallel models with the error growth rate when the sequential model input is perturbed to simulate floating point rounding error. Series of runs on increasing numbers of parallel processors demonstrate that the parallel implementation is efficient and scalable to large numbers of processors.

  2. Manufacturing and performance test of an 800-mm space optic

    NASA Astrophysics Data System (ADS)

    Krödel, Matthias R.; Ozaki, Tsuyoshi; Kume, Masami; Furuya, Akira; Yui, Yukari Y.; Imai, Hiroko; Katayama, Haruyoshi; Tange, Yoshio; Nakagawa, Takao; Kaneda, Hidehiro

    2008-07-01

    Next generation space telescopes, which are currently being developed in the US and Europe, require large-scale light-weight reflectors with high specific strength, high specific stiffness, low CTE, and high thermal conductivity. To meet budget constraints, they also require materials that produce surfaces suitable for polishing without expensive over-coatings. HB-Cesic - a European and Japanese trademark of ECM - is a Hybrid Carbon-Fiber Reinforced SiC composite developed jointly by ECM and MELCO to meet these challenges. The material's mechanical performance, such as stiffness, bending strength, and fracture toughness are significantly improved compared to the classic ECM Cesic material (type MF). Thermal expansion and thermal conductivity of HB-Cesic at cryogenic temperatures are now partly established; and excellent performance for large future space mirrors and structures are expected. This paper presents the design and manufacturing of an 800-mm mirror for space application, starting with the C/C raw material preparation to the finishing of the components, including the polishing of the mirror. The letters "HB" in HB-Cesic stand for "hybrid" to indicate that the C/C raw material is composed of a mixture of different types of chopped, short carbon-fibers.

  3. Kinetic Inductance Detectors development for mm-wave Astronomy

    NASA Astrophysics Data System (ADS)

    Monfardini, A.; Swenson, L. J.; Benoit, A.; Bideau, A.; Bres, G.; Camus, P.; Garde, G.; Hoffmann, C.; Minet, J.; Rodenas, H.; Nika Collaboration

    Throughout the last decades, development of low-temperat- ure detectors focused mainly on the design of high-sensitivity, single-pixel devices. This includes such devices as semiconductor-based photodetectors and bolometers, Magnetic Metallic Calorimeters (MMC), Superconducting Tunnel Junctions (STJ), and Transition Edge Sensors (TES). However, these devices have had limited success in achieving the simultaneous large-scale array sizes and large-bandwidth operation necessary for high-speed, high-resolution detection. To overcome this performance limitation, it is advisable to focus on low-temperature detectors which are intrinsically adapted to giant-array multiplexing and ultra-fast readout. To adopt large scale frequency-domain multiplexing for low-temperature detectors, it is necessary to find detectors which"broadcast" at microwave frequencies. Superconducting microwave resonators naturally lend themselves to this task. One recent demonstration is an implementation known as Kinetic Inductance Detectors (KIDs). This detection mechanism can be adopted for low-energy EM radiation (radio, mm, THz) in continuous mode, or in pulsed mode for higher energy radiation and particles. We present an ongoing development for a KIDs instrument dedicated to millimetric ground-based observations at the 30m IRAM telescope at Pico Veleta. The Neel IRAM KIDs Array (NIKA) project is coordinated in Grenoble and involves groups in Holland (SRON), UK (Cardiff) and Italy (Roma).

  4. HO(x) Measurements in PEM Tropics B with the Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS)

    NASA Technical Reports Server (NTRS)

    Brune, William H.

    2001-01-01

    The primary objective of PEM Tropics B was to study the processes responsible for the production and loss of tropospheric ozone over the tropical Pacific. This region of the globe contains very clean air as well as aged, polluted air that was advected from both the Asian and American continents. Understanding ozone requires understanding of HO(x) (HO(x) = OH + HO2) chemistry, since the reaction between H02 and NO leads to ozone production and the production of OH often requires ozone loss. In addition, OH is the atmosphere's primary oxidant. Since most atmospheric oxidation is thought to occur in the tropical lower troposphere, measurements during PEM Tropics B should provide an important test of the OH abundances and distributions. Thus, understanding and thoroughly testing HO(x) processes was an important objective of PEM Tropics B. Several issues need to be tested, One is HO, production rates and sources, since HO,, production directly affects ozone production and loss. Another is HO(x) behavior in and around clouds, since HO(x) is lost to cloud particles, but convection may bring HO(x) precursors from near the surface to the upper troposphere. A third is the rise and fall of HO(x) at sunrise and sunset, since these variations give strong indications of the important sources and sinks of HO(x). Making and interpreting high-quality OH and H02 measurements from the NASA DC-8 during PEM Tropics B is the objective of this research effort.

  5. Isotopic fractionation of Mg 2+(aq), Ca 2+(aq), and Fe 2+(aq) with carbonate minerals

    NASA Astrophysics Data System (ADS)

    Rustad, James R.; Casey, William H.; Yin, Qing-Zhu; Bylaska, Eric J.; Felmy, Andrew R.; Bogatko, Stuart A.; Jackson, Virgil E.; Dixon, David A.

    2010-11-01

    Density-functional electronic structure calculations are used to compute the equilibrium constants for 26Mg/ 24Mg and 44Ca/ 40Ca isotope exchange between carbonate minerals and uncomplexed divalent aquo ions. The most reliable calculations at the B3LYP/6-311++G(2d,2p) level predict equilibrium constants K, reported as 10 3ln ( K) at 25 °C, of -5.3, -1.1, and +1.2 for 26Mg/ 24Mg exchange between calcite (CaCO 3), magnesite (MgCO 3), and dolomite (Ca 0.5Mg 0.5CO 3), respectively, and Mg 2+(aq), with positive values indicating enrichment of the heavy isotope in the mineral phase. For 44Ca/ 40Ca exchange between calcite and Ca 2+(aq) at 25 °C, the calculations predict values of +1.5 for Ca 2+(aq) in 6-fold coordination and +4.1 for Ca 2+(aq) in 7-fold coordination. We find that the reduced partition function ratios can be reliably computed from systems as small as M(CO)610- and M(HO)62+ embedded in a set of fixed atoms representing the second-shell (and greater) coordination environment. We find that the aqueous cluster representing the aquo ion is much more sensitive to improvements in the basis set than the calculations on the mineral systems, and that fractionation factors should be computed using the best possible basis set for the aquo complex, even if the reduced partition function ratio calculated with the same basis set is not available for the mineral system. The new calculations show that the previous discrepancies between theory and experiment for Fe 3+-hematite and Fe 2+-siderite fractionations arise from an insufficiently accurate reduced partition function ratio for the Fe 3+(aq) and Fe 2+(aq) species.

  6. Lattice effects in HoVo 3 single crystal

    NASA Astrophysics Data System (ADS)

    Sikora, M.; Marquina, C.; Ibarra, M. R.; Nugroho, A. A.; Palstra, T. T. M.

    2007-09-01

    We report the study of lattice effects in the Mott insulator HoVO 3 performed by means of linear thermal expansion on a single crystal in the temperature range 10-290 K. The holmium orthovanadate HoVO 3 reveals gradual orbital ordering (OO) below TOO=200 K and orders antiferromagnetically at TN=113 K. A first-order structural phase transition takes place at TS˜38 K, which is probably accompanied by change of the OO type and hence the type of antiferromagnetic spin ordering.

  7. Catecholamines-evoked cytosolic Ca2+ rise in endothelial cells from bovine adrenal medulla.

    PubMed

    Vinet, R; Rojas, F; Luxoro, M; Vargas, F; Cortés, M

    2000-01-01

    The effects of catecholamines on intracellular Ca2+ concentrations ([Ca2+]i) in single acutely dissociated bovine adrenal medulla endothelial cells (BAMECs) were measured using the intracellular fluorescent probe Fluo-3 AM. 100 microm epinephrine or norepinephrine induced a biphasic [Ca2+]i rise with an initial peak followed by a delayed phase. 10 microm phenylephrine (alpha1-adrenergic agonist) caused a [Ca2+]i rise similar to that evoked by catecholamines. The increase in [Ca2+]i induced by 10 microm phenylephrine was reverted by 10 microm phenoxybenzamine (alpha-adrenergic antagonist). Neither isoproterenol (beta-adrenergic agonist) nor clonidine (alpha2-adrenergic agonist) induced [Ca2+]i rise. The initial peak was insensitive to zero external Ca2+ and it was abolished after Ca2+ internal storages were emptied by 10 mM caffeine. The delayed phase was reduced to near zero by external Ca2+ removal. These results indicate that BAMECs possess alpha1-adrenergic receptors associated to both the release of caffeine-sensitive intracellular Ca2+ stores and the entry of extracellular Ca2+. We suggest that chromaffin cell secretion may activate BAMECs in vivo through an increase in [Ca2+]i which could induce the secretion of vasoactive factors allowing a rapid entry of hormones into the circulation. PMID:10724332

  8. Management of anterior caliceal stones >15 mm.

    PubMed

    El-Shazly, M; Aziz, M; Omar, M; Al-Hunaidi, O; El-Nahas, A R

    2016-08-01

    Anterior caliceal stones represent a challenge to endourologist to select the best modality of management with the least morbidity. To study different treatment modalities of management of anterior caliceal stones >15 mm. It is an observational prospective study of patients with anterior caliceal stones more than 15 mm. Inclusion criteria were patients with isolated anterior caliceal stones, or branched anterior caliceal stones with posterior caliceal extension. Patients were evaluated using non-contrast CT preoperatively. They were divided into three groups: group 1 underwent PCNL through posterior caliceal puncture in cases with wide anterior calyx infundibulum or obtuse infundibulopelvic pelvic, group 2 underwent PCNL through anterior caliceal access in cases with narrow infundibulum or acute infundibulopelvic angel and group 3 underwent flexible ureteroscopy and laser lithotripsy. Intraoperative and postoperative findings were recorded and compared. Eighty eight patients were included in this study, Group 1 (44 patients) group 2 (28 patients), and group 3 (16 patients). Operative time was not significantly different across the three groups (68 ± 11.5, 72 ± 9 and 74 ± 11 min in group 1, 2 and 3, respectively, P = 0.053). Fluoroscopy time was significantly shorter for group 3 (2 ± 0.5 m, P = 0.0001) compared to group 1 and 2 (5.6 ± 4.6 and 4.5 ± 1.4 min), respectively. There were no significant differences in stone-free rates after initial treatment between the three groups; 84, 82, and 69 %, in groups 1, 2 and 3, respectively (P = 0.4). Postoperative hemoglobin drop was noted to be highest for group 2 and lowest for group 3 which was significantly different (1.7 ± 0.8, 2.2 ± 1.1, and 0.3 ± 0.3 g/dl, for patients in groups 1, 2 and 3 respectively, P = 0.0001). Group 2 showed the highest post-operative complication rate (21 %) in comparison to group 1 (11 %) and group 3 (6 %), however, differences were not statistically

  9. Electronic transitions of Ho in Pb2Sr2HoCu3O8 observed by inelastic neutron scattering

    NASA Astrophysics Data System (ADS)

    Soderholm, L.; Loong, C.-K.; Xue, J. S.; Hammonds, J. P.; Greedan, J. E.; Maric, M.

    1993-05-01

    The electronic behavior of the 5I8 Russell Saunders ground multiplet of Ho3+ in Pb2Sr2HoCu3O8 has been investigated using inelastic neutron scattering. We observe ten peaks in the excitation spectra that are associated with crystal field transitions. The peaks are only slightly broader than expected from instrument resolution, indicating that there are no strong interactions between the local Ho f states and the CuO conduction states. Comparing the energies and intensities of the experimental peaks with those expected from modeling convinces us that there are at least three states populated at the temperature of our experiment (15 K), making the assignments of transitions very difficult in the absence of further data.

  10. Coachella Valley, CA

    NASA Technical Reports Server (NTRS)

    2001-01-01

    These band composites, acquired on June 4, 2000, cover a 11 by 13.5 km sub-scene in the Coachella Valley, CA. The area is shown by the yellow box on the full scene in the LOWER RIGHT corner, northwest of the Salton Sea. This is a major agricultural region of California, growing fruit and produce throughout the year. Different combinations of ASTER bands help identify the different crop types. UPPER LEFT: bands 3, 2, 1 as red, green, and blue (RGB); UPPER RIGHT: bands 4, 2, 1 as RGB; LOWER LEFT: bands 4, 3, 2 as RGB. The image is centered at 33.6 degrees north latitude, 116.1 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  11. An Efficient Single Frequency Ho:YLF Laser for IPDA Lidar Applications

    NASA Technical Reports Server (NTRS)

    Yu, J.; Bai, Y.; Wong, T.; Reithmeier, K.; Petros, M.

    2016-01-01

    A highly efficient, versatile, single frequency 2-micron pulsed laser can be used in a pulsed Differential Absorption Lidar (DIAL) / Integrated Path Differential Absorption (IPDA) instrument to make precise, high-resolution measurements to investigate sources and sinks of CO2. For a direct detection IPDA lidar, the desired 2 ?m Ho:YLF laser should generate 30-40 mJ pulses at the repetition rate of 100 to 200 Hz, with short pulse length (<100 ns) and better than 2% wall plug efficiency. A Tm fiber laser in-band pumped Ho:YLF laser has been developed to meet this technical challenge. This Ho:YLF laser is designed in a four mirror ring resonator with bow tie configuration, which helps to obtain high beam quality. It is end-pumped by a 40 W linearly polarized Tm fiber laser at 1.94µm. The resonator length is 1.10 meters with output coupler reflectivity at 45%. The laser crystal size is 3 x 3 x 60 mm (w, h, l) with a doping concentration of 0.5% Holmium. The laser beam and pump beam are mode-matched in the active medium. Thus, the pump and laser beams have the same confocal parameters. Mode-matching is also helpful for operating the laser in a single transverse mode. The laser beam waist is slightly less than 0.5 mm at the center of the laser crystal. Based on quasi-four level modeling, pump absorption and saturation depend on laser intensity. Laser amplification and saturation also depend on the pump intensity in the crystal. The laser is injection seeded to obtain the single frequency required by an IPDA lidar measurement. The seed beam is entered into the resonator through an output coupler. The laser is mounted on a water cooled optical bench for stable and reliable operation. The size of the optical bench is 22.16 x 9.20 x 1.25 inches. It is stiffened so that the laser can be operated in any orientation of the optical bench. This packaged Ho:YLF laser is designed for either mobile trailer or airborne platform operation. The engineering prototype Ho:YLF laser has

  12. Multiple effects of ryanodine on intracellular free Ca2+ in smooth muscle cells from bovine and porcine coronary artery: modulation of sarcoplasmic reticulum function.

    PubMed Central

    Wagner-Mann, C.; Hu, Q.; Sturek, M.

    1992-01-01

    1. The effects of ryanodine and caffeine on intracellular free Ca2+ concentration ([Ca2+]i) were studied by use of fura-2 microfluorometry in single smooth muscle cells freshly dispersed from bovine and porcine coronary artery. 2. Bovine and porcine cells demonstrated similar sensitivities to 10 min of exposure to ryanodine in physiological salt solution (PSS), as determined by comparable dose-dependent decreases in the subsequent [Ca2+]i transient induced by 5 mM caffeine. 3. Ryanodine (10 microM) caused a significant increase in [Ca2+]i to a plateau level 27 +/- 3% and 38 +/- 4% above baseline [Ca2+]i (baseline [Ca2+]i = [Ca2+]i at 0 min) in porcine and bovine cells, respectively, when bathed in PSS. In bovine cells the time required to reach 1/2 the plateau level was only 3 min versus 6 min for porcine cells. 4. The ryanodine-induced plateau increase in [Ca2+]i was 35 +/- 5% above baseline for bovine cells bathed in 0 Ca PSS (PSS including 10 microM EGTA with no added Ca2+), but only 7 +/- 3% above baseline in porcine cells during 10 min exposure to 10 microM ryanodine. In bovine cells [Ca2+]i showed proportional increases when extracellular Ca2+ was increased from the normal 2 mM Ca2+ PSS to 5 and 10 mM. 5. Cells pretreated with caffeine in 0 Ca PSS, which depleted the caffeine-sensitive sarcoplasmic reticulum Ca2+ store, showed no increase in [Ca2+]i when challenged with 10 microM ryanodine. The ryanodine-associated increase in [Ca2+]i, which was sustained in 0 Ca PSS during the 10 min ryanodine exposure in cells not pretreated with caffeine, suggests that ryanodine releases Ca2+ from the sarcoplasmic reticulum, but also inhibits Ca2+ efflux.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1 PMID:1504718

  13. Role of modifier oxide in emission spectra and kinetics of Er-Ho codoped Na2SO(4)-MO-P2O5 glasses.

    PubMed

    Rao, P Raghava; Venkatramaiah, N; Gandhi, Y; Kumar, V Ravi; Kityk, I V; Veeraiah, N

    2012-02-01

    The glasses of the composition 19Na(2)SO(4)-20MO-60P(2)O(5): 1.0Ho(2)O(3)/1.0Er(2)O(3) (M=Mg, Ca, and Ba) have been synthesized. Optical absorption and fluorescence spectra (in the spectral range 350-2100 nm were studied at ambient temperature. The spectra were characterized using Judd-Ofelt theory. From the luminescence spectra, various radiative properties like transition probability A, branching ratio β and the radiative life time τ for blue (B), green (G) and red (R) emission levels of these glasses have been evaluated. The energy transfer between the two rare earth ions (Ho(3+) and Er(3+)) in co-doped Na(2)SO(4)-MO-P(2)O(5) glass systems in the visible and NIR regions has also been investigated. Highest intensity, the highest quantum efficiency and maximum energy transfer with low phonon losses of B, G, and R lines has been observed in BaO mixed glasses. The reasons for such higher values of these parameters have been discussed in the light of varying field strengths at the rare earths ion site due to replacement of one modifier oxide with the other. The enhanced intensity of NIR emission (at 2.0 μm) has also been discussed in terms of cross relaxation of Er(3+) ions from (4)I(13/2) level to (5)I(7) of Ho(3+) ions. PMID:22112571

  14. Demonstration Report: ESTCP UXO Discrimination Study ESTCP PROJECT # MM-0838

    SciTech Connect

    Gasperikova, Erika

    2010-02-15

    second study in 2009 at the former Camp San Luis Obispo, CA, a site with more challenging topography and a wider mix of targets-of-interest (TOI). There were two primary objectives of this study: (1) Test and validate detection and discrimination capabilities of currently available and emerging technologies on real sites under operational conditions; and (2) Investigate in cooperation with regulators and program managers how discrimination technologies can be implemented in cleanup operations.

  15. Optical transitions of Ho(3+) in oxyfluoride glasses and upconversion luminescence of Ho(3+)/Yb(3+)-codoped oxyfluoride glasses.

    PubMed

    Feng, Li; Wu, Yinsu

    2015-05-01

    Optical properties of Ho(3+)-doped SiO2-BaF2-ZnF2 glasses have been investigated on the basis of the Judd-Ofelt theory. Judd-Ofelt intensity parameters, radiative transition probabilities, fluorescence branching ratios and radiative lifetimes have been calculated for different glass compositions. Upconversion emissions were observed in Ho(3+)/Yb(3+)-codoped SiO2-BaF2-ZnF2 glasses under 980nm excitation. The effects of composition, concentration of the doping ions, and excitation pump power on the upconversion emissions were also systematically studied. PMID:25703369

  16. Theoretical characterization of the minimum energy path for the reaction H + O2 to HO2(asterisk) to HO + O

    NASA Technical Reports Server (NTRS)

    Walch, Stephen P.; Rohlfing, Celeste Mcmichael; Melius, Carl F.; Bauschlicher, Charles W., Jr.

    1988-01-01

    The potential energy surface for the H + O2 to HO2(asterisk) to HO + O reaction has been investigated in the region of the minimum energy path using CASSCF/contracted CI (CCI) calculations with a large basis set. The results show no barrier for the addition of an H atom to O2, in agreement with previous studies. A crossing between the surface for electrostatic (OH dipole-O quadrupole) interaction and that for the formation of an O-O chemical bond, at r(infinity) of about 5.5 a(0), results in a small (about 0.5 kcal/mol) barrier.

  17. Evidence for a Ca(2+)-gated ryanodine-sensitive Ca2+ release channel in visceral smooth muscle.

    PubMed Central

    Xu, L; Lai, F A; Cohn, A; Etter, E; Guerrero, A; Fay, F S; Meissner, G

    1994-01-01

    Although a role for the ryanodine receptor (RyR) in Ca2+ signaling in smooth muscle has been inferred, direct information on the biochemical and functional properties of the receptor has been largely lacking. Studies were thus carried out to purify and characterize the RyR in stomach smooth muscle cells from the toad Bufo marinus. Intracellular Ca2+ measurements with the Ca(2+)-sensitive fluorescent indicator fura-2 under voltage clamp indicated the presence of a caffeine- and ryanodine-sensitive internal store for Ca2+ in these cells. The (CHAPS)-solubilized, [3H]ryanodine-labeled RyR of toad smooth muscle was partially purified from microsomal membranes by rate density centrifugation as a 30-S protein complex. SDS/PAGE indicated the comigration of a high molecular weight polypeptide with the peak attributed to 30-S RyR, which had a mobility similar to the cardiac RyR and on immunoblots cross-reacted with a monoclonal antibody to the canine cardiac RyR. Following planar lipid bilayer reconstitution of 30-S stomach muscle RyR fractions, single-channel currents (830 pS with 250 mM K+ as the permeant ion) were observed that were activated by Ca2+ and modified by ryanodine. In vesicle-45Ca2+ efflux measurements, the toad channel was activated to a greater extent at 100-1000 microM than 1-10 microM Ca2+. These results suggest that toad stomach muscle contains a ryanodine-sensitive Ca2+ release channel with properties similar but not identical to those of the mammalian skeletal and cardiac Ca(2+)-release channels. Images PMID:8159742

  18. Dosimetric study of the 15 mm ROPES eye plaque.

    PubMed

    Granero, D; Pérez-Calatayud, J; Ballester, F; Casal, E; de Frutos, J M

    2004-12-01

    The main aim of this paper is to make a study of dose-rate distributions obtained around the 15 mm, radiation oncology physics and engineering services, Australia (ROPES) eye plaque loaded with 125I model 6711 radioactive seeds. In this study, we have carried out a comparison of the dose-rate distributions obtained by the algorithm used by the Plaque Simulator (PS) (BEBIG GmbH, Berlin, Germany) treatment planning system with those obtained by means of the Monte Carlo method for the ROPES eye plaque. A simple method to obtain the dose-rate distributions in a treatment planning system via the superposition of the dose-rate distributions of a seed placed in the eye plaque has been developed. The method uses eye plaque located in a simplified geometry of the head anatomy and distributions obtained by means of the Monte Carlo code GEANT4. The favorable results obtained in the development of this method suggest that it could be implemented on a treatment planning system to improve dose-rate calculations. We have also found that the dose-rate falls sharply along the eye and that outside the eye the dose-rate is very low. Furthermore, the lack of backscatter photons from the air located outside the eye-head phantom produces a dose reduction negligible for distances from the eye-plaque r<1 cm but reaches up to 20% near the air-eye interface. Results showed that the treatment planning system lacks accuracy around the border of the eye (in the sclera and the surrounding area) due to the simplicity of the algorithm used. The BEBIG treatment planning system uses a global attenuation factor that takes into account the effect of the eye plaque seed carrier and the lack of backscatter photons caused by the metallic cover, which in the case of a ROPES eye plaque has a default value of T= 1 (no correction). In the present study, a global attenuation factor T=0.96 and an air-interface correction factor which improve on treatment planning system calculations were obtained. PMID

  19. Dosimetric study of the 15 mm ROPES eye plaque

    SciTech Connect

    Granero, D.; Perez-Calatayud, J.; Ballester, F.; Casal, E.; Frutos, J.M. de

    2004-12-01

    The main aim of this paper is to make a study of dose-rate distributions obtained around the 15 mm, radiation oncology physics and engineering services, Australia (ROPES) eye plaque loaded with {sup 125}I model 6711 radioactive seeds. In this study, we have carried out a comparison of the dose-rate distributions obtained by the algorithm used by the Plaque Simulator (PS) (BEBIG GmbH, Berlin, Germany) treatment planning system with those obtained by means of the Monte Carlo method for the ROPES eye plaque. A simple method to obtain the dose-rate distributions in a treatment planning system via the superposition of the dose-rate distributions of a seed placed in the eye plaque has been developed. The method uses eye plaque located in a simplified geometry of the head anatomy and distributions obtained by means of the Monte Carlo code GEANT4. The favorable results obtained in the development of this method suggest that it could be implemented on a treatment planning system to improve dose-rate calculations. We have also found that the dose-rate falls sharply along the eye and that outside the eye the dose-rate is very low. Furthermore, the lack of backscatter photons from the air located outside the eye-head phantom produces a dose reduction negligible for distances from the eye-plaque r<1 cm but reaches up to 20% near the air-eye interface. Results showed that the treatment planning system lacks accuracy around the border of the eye (in the sclera and the surrounding area) due to the simplicity of the algorithm used. The BEBIG treatment planning system uses a global attenuation factor that takes into account the effect of the eye plaque seed carrier and the lack of backscatter photons caused by the metallic cover, which in the case of a ROPES eye plaque has a default value of T=1 (no correction). In the present study, a global attenuation factor T=0.96 and an air-interface correction factor which improve on treatment planning system calculations were obtained.

  20. [Cationic specificity of a Ca2+-accumulating system in smooth muscle cell mitochondria].

    PubMed

    Veklich, T O; Kosterin, S O; Shynlova, O P

    2002-01-01

    In the experiments conducted with application of an isotopic technique (45Ca2+) on the myometrium cells suspension treated by digitonin solution (0.1 mg/ml) some properties of Ca ions accumulation system in the mitochondria--cationic and substrate specificity as well as effects of Mg2+ and some other bivalent metals ions on the Ca2+ accumulation velocity have been estimated. Ca ions accumulation from the incubation medium containing 3 mM sodium succinate Na, 2 mM Pi (as potassium K(+)-phosphate buffer, pH 7.4 at 37 degrees C), 0.01 mM (40CaCl2 + 45CaCl2) and 100 nM thapsigargin--selective inhibiting agent of endoplasmatic reticulum calcium pump were demonstrated as detected just only in presence of Mg, while not Ni, Co or Cu ions. The increase of Mg2+ concentration from 1 x 10(-6) to 10(-3) M induced the ATP dependent transport activation in the myometrium mitochondria. Under [Mg2+] increase till 40 mM this cation essentially decreased Ca2+ accumulation (by 65% from the maximal value). The optimum for Ca2+ transport in the myometrium cells suspension is Mg2+ 10 mM concentration. Ka activation apparent constant along Mg2+ value (in presence 3 mM ATP and 3 mM sodium succinate) is 4.27 mM. The above listed bivalent metals decreased Mg2+, ATP-dependent accumulation of calcium, values of inhibition apparent constants for ions Co2+, Ni2+ and Cu2+ were--2.9 x 10(-4) M, 5.1 x 10(-5) M and 4.2 x 10(-6) M respectively. For Mg2+, ATP-dependent Ca2+ transport in the uterus myocytes mitocondria a high substrate specificity is a characteristic phenomenon in elation to ATP: GTP, CTP and UTP practically fail to provide for Ca accumulation process. PMID:12199098

  1. Nuclear spectroscopy above isomers in {sub 67}{sup 148}Ho{sub 81} and {sub 67}{sup 149}Ho{sub 82} nuclei: Search for core-excited states in {sup 149}Ho

    SciTech Connect

    Kownacki, J.; Napiorkowski, P. J.; Zielinska, M.; Kordyasz, A.; Srebrny, J.; Droste, Ch.; Morek, T.; Grodner, E.; Ruchowska, E.; Korman, A.; Czarnacki, W.; Kisielinski, M.; Kowalczyk, M.; Wrzosek-Lipska, K.; Hadynska-KlePk, K.; Mierzejewski, J.; Lieder, R. M.; Perkowski, J.; Andrzejewski, J.; Krol, A.

    2010-04-15

    The excited states of {sup 148}Ho and {sup 149}Ho isotopes are studied using gamma-ray and electron spectroscopy in off-beam and in-beam modes following {sup 112,114}Sn({sup 40}Ar,xnyp) reactions. Experiments include measurements of single gamma-rays and conversion electron spectra as well as gamma-gamma, electron-gamma, gamma-t, and gamma-gamma-t coincidences with the use of the OSIRIS-II 12-HPGe array and conversion electron spectrometer. Based on the present results, the level schemes of {sup 148}Ho and {sup 149}Ho are revised and significantly extended, up to about 4 and 5 MeV of excitation energy, respectively. Spin and parity of 5{sup -} are assigned to the 9.59-s isomer in {sup 148}Ho based on conversion electron results. Previously unobserved gamma rays feeding the 10{sup +} isomer in {sup 148}Ho and the 27/2{sup -} isomer in {sup 149}Ho nuclei are proposed. Shell-model calculations are performed. Possible core-excited states in {sup 149}Ho are discussed.

  2. A comparable study of clinical and optical outcomes after 1.8, 2.0 mm microcoaxial and 3.0 mm coaxial cataract surgery

    PubMed Central

    Yu, Yi-Bo; Zhu, Ya-Nan; Wang, Wei; Zhang, Yi-Dong; Yu, Yin-Hui; Yao, Ke

    2016-01-01

    AIM To evaluate the clinical and optical outcomes after clear corneal incision cataract surgery (CICS) with three different incision sizes (1.8, 2.0 and 3.0 mm). METHODS Eyes of 150 patients with age-related cataract scheduled for coaxial cataract surgery were randomized to three groups: 1.8, 2.0, or 3.0 mm CICS. Intraoperative data and postoperative outcomes including surgically induced astigmatism (SIA), the corneal incision thickness, wavefront aberrations and modulation transfer function (MTF) of cornea were obtained. RESULTS There were no significant differences among the three groups in demographic characteristics and intraoperative outcome. The 1.8 and 2.0 mm microincisions showed more satisfactory clinical outcomes than the 3.0 mm incision. The 1.8 mm incision showed significantly less SIA than the 2.0 mm incision until postoperative 1mo (P<0.05), but the difference was only 0.14-0.18 D. Combined with less increased incision thickness only at postoperative 1d (P=0.013), the 1.8 mm incision presented better uncorrected distance visual acuity (UCDVA) than the 2.0 mm incision only at 1d postoperatively (P=0.008). For higher-order aberrations and other Zernike coefficients, there were no significant differences between the 1.8 mm group and 2.0 mm group (P>0.05). CONCLUSION Converting from 3.0 mm CICS to 1.8 or 2.0 mm CICS result in better clinical and optical outcomes. However, when incision is 1.8 mm, the benefits from further reduction in size compared with 2.0 mm are limited. The necessity to reduce the incision size is to be deliberated. PMID:27158610

  3. Simultaneous measurement of Ca2+ influx and reversal potentials in recombinant N-methyl-D-aspartate receptor channels.

    PubMed Central

    Schneggenburger, R

    1996-01-01

    The Ca(2+) permeability of N-methyl-D-aspartate receptor (NMDA-R) channels was studied in human embryonic kidney cells transfected with the NR1-NR2A subunit combination. To determine the fractional Ca(2+) current (P(f)), measurements of fura-2-based Ca(2+) influx and whole-cell currents were made in symmetrical monovalent ion concentrations at membrane potentials between -50 mV and the reversal potential. The ratios of Ca(2+) flux over net whole-cell charge at 2, 5, and 10 mM external Ca(2+) concentrations ([Ca](o)) were identical at a membrane potential close to the reversal potential of the monovalent current component. Assuming unity of P(f) at this potential, the percentage of current carried by Ca(2+) was found to be 18.5 +/- 1.3% at 2 mM [Ca](o) and -50 mV. This value, which is higher than the ones reported previously, was confirmed in independent experiments in which a pure flux of Ca(2+) through NMDA-R channels was used to calibrate the Ca(2+) influx signals. The measured values of fractional Ca(2+) currents, which agree with the predictions of the Goldman-Hodgkin-Katz equations, are also compatible with a two-barrier model for ion permeation, in which the differences between the energy barriers for Ca(2+) and monovalent ions are similar on the external and internal membrane sides. Images FIGURE 5 PMID:9172740

  4. Single-channel properties of the recombinant skeletal muscle Ca2+ release channel (ryanodine receptor).

    PubMed Central

    Chen, S R; Leong, P; Imredy, J P; Bartlett, C; Zhang, L; MacLennan, D H

    1997-01-01

    We report transient expression of a full-length cDNA encoding the Ca2+ release channel of rabbit skeletal muscle sarcoplasmic reticulum (ryanodine receptor) in HEK-293 cells. The single-channel properties of the 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate-solubilized and sucrose gradient-purified recombinant Ca2+ release channels were investigated by using single-channel recordings in planar lipid bilayers. The recombinant Ca2+ release channel exhibited a K+ conductance of 780 pS when symmetrical 250 mM KCl was used as the conducting ion and a Ca2+ conductance of 116 pS in 50 mM luminal Ca2+. Opening events of the recombinant channels were brief, with an open time constant of approximately 0.22 ms. The recombinant Ca2+ release channel was more permeable to Ca2+ than to K+, with a pCa2+/pK+ ratio of 6.8. The response of the recombinant Ca2+ release channel to various concentrations of Ca2+ was biphasic, with the channel being activated by micromolar Ca2+ and inhibited by millimolar Ca2+. The recombinant channels were activated by ATP and caffeine, inhibited by Mg2+ and ruthenium red, and modified by ryanodine. Most recombinant channels were asymmetrically blocked, conducting current unidirectionally from the luminal to the cytoplasmic side of the channel. These data demonstrate that the properties of recombinant Ca2+ release channel expressed in HEK-293 cells are very similar, if not identical, to those of the native channel. Images FIGURE 1 PMID:9336186

  5. The role of Ca(2+) and Na (+) membrane transport in brook trout (Salvelinus fontinalis) spermatozoa motility.

    PubMed

    Bondarenko, Olga; Dzyuba, Borys; Cosson, Jacky; Rodina, Marek; Linhart, Otomar

    2014-10-01

    The role of environmental ion composition and osmolality in Ca(2+) signaled activation was assessed in spermatozoa of brook trout Salvelinus fontinalis. Milt from ten mature males was obtained by abdominal massage. Spermatozoa motility was evaluated in 0, 100, and 300 mOsm/kg NaCl or sucrose solutions, buffered by 10 mM Tris-HCl pH 8.5. For investigation of spermatozoa reaction to external Ca(2+) concentration, 2 mM ethylene glycol tetraacetic acid (EGTA) was added to the activation media as a calcium ions chelator. For investigation of the effect of external Na(+) concentration in conditions of low external Ca(2+), 100 µM amiloride was added to the EGTA-containing solutions as a Na(+) transport blocker. Low motility was observed in sucrose (Na(+) free) solutions containing 2 mM EGTA but not in Na(+) solutions containing 2 mM EGTA. Addition of amiloride led to significantly increased motility (P < 0.05) compared with sucrose (Na(+) free) solutions containing 2 mM EGTA. We conclude that Na(+) transport in Ca(2+)-free solutions plays a regulatory role in brook trout spermatozoa activation. The influence of competitive Na(+) and Ca(2+) transport on the control of spermatozoa activation requires further study with respect to its application for improvement of artificial activation and storage media. PMID:24718964

  6. Mechanism and stability of spectrally pure green up-conversion emission in Yb(3+)/Ho(3+) co-doped Ba5Gd8Zn4O21 phosphors.

    PubMed

    Suo, Hao; Guo, Chongfeng; Wang, Wenbin; Li, Ting; Duan, Changkui; Yin, Min

    2016-02-14

    A series of green-emitting up-conversion (UC) phosphors Ba5Gd8Zn4O21:Yb(3+),Ho(3+) were prepared by a modified sol-gel method, and X-ray diffraction (XRD) patterns were measured to characterize the crystal structure. The obtained UC samples emit dazzling green light and their spectra are composed of strong green emission peaking at 544 nm and negligible red emission peaking at 666 nm with the excitation of a 980 nm near-infrared (NIR) laser diode, assigned to (5)F4/(5)S2 → (5)I8 and (5)F5 → (5)I8 transitions of Ho(3+), respectively. The dependence of UC spectra on dopant contents, temperature and pumping power was employed to analyze UC emission color stability. The possible UC mechanisms and processes were proposed based on dependence of the UC emission intensity on pump power, and the lifetimes of green emission ((5)F4/(5)S2 → (5)I8) were also investigated to better comprehend the energy transfer (ET) process. The origin of spectrally pure green-emitting was discussed in detail by analyzing UC and down-conversion (DC) spectra in both the visible and NIR region by comparing that of the UC phosphor CaIn2O4:Yb(3+)/Ho(3+) with highly efficient green emission. Results suggest that Ba5Gd8Zn4O21:Yb(3+),Ho(3+) phosphors with intense green emission and high color purity have potential applications in displays and illuminating technology. PMID:26732549

  7. Registration of ‘Ho 02-113’ Sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ho 02-113’ sugarcane was released by the USDA-ARS Sugarcane Research Unit working cooperatively with the Louisiana State University Agricultural Center, and the American Sugarcane League of the U.S.A. This high-fiber sugarcane variety was released for use as a biofuel feedstock to fill the rising i...

  8. Conductively Cooled Ho:Tm:LuLiF Laser Amplifier

    NASA Technical Reports Server (NTRS)

    Bai, Yingxin; Yu, Jirong; Trieu, Bo; Petros, M.; Petzar, Paul; Lee, Hyung; Singh, U.

    2008-01-01

    A conductively-cooled Ho:Tm:LuLiF laser head can amplify 80mJ/340ns probe pulses into 400mJ when the pump pulse energy is close to amplified spontaneous emission (ASE) threshold, 5.6J. For a small signal, the double-pass amplification exceeds 25.

  9. Temperature Dependence of the O + HO2 Rate Coefficient

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Wine, P. H.

    1997-01-01

    A pulsed laser photolysis technique has been employed to investigate the kinetics of the radical-radical reaction O((sup 3)P) + HO2 OH + O2 over the temperature range 266-391 K in 80 Torr of N2 diluent gas. O((sup 3)P) was produced by 248.5-nm KrF laser photolysis of O3 followed by rapid quenching of O(1D) to O((sup 3)P) while HO2 was produced by simultaneous photolysis of H2O2 to create OH radicals which, in turn, reacted with H2O2 to yield HO2. The O((sup 3)P) temporal profile was monitored by using time-resolved resonance fluorescence spectroscopy. The HO2 concentration was calculated based on experimentally measured parameters. The following Arrhenius expression describes our experimental results: k(sub 1)(T) equals (2.91 +/- 0.70) x 10(exp -11) exp[(228 +/- 75)/T] where the errors are 2 sigma and represent precision only. The absolute uncertainty in k, at any temperature within the range 266-391 K is estimated to be +/- 22 percent. Our results are in excellent agreement with a discharge flow study of the temperature dependence of k(sub 1) in 1 Torr of He diluent reported by Keyser, and significantly reduce the uncertainty in the rate of this important stratospheric reaction at subambient temperatures.

  10. 2008 Louisiana "HoCP" Nursery and Infield Variety Trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three years after selection in single-stools at the seedling stage, scientists in the breeding program assign permanent “HoCP” or “Ho” numbers to experimental varieties advanced for further testing. These newly assigned varieties are planted in replicated nursery trials at three locations (Ardoyne ...

  11. Programme Note: Realities and Opportunities in Ho Chi Minh City.

    ERIC Educational Resources Information Center

    Franchet, Chi Nguyen

    1996-01-01

    The current status of street children in Ho Chi Minh City, Vietnam, is characterized by marginalization from society through street vending, begging, theft, and prostitution. Evaluation of a drop-in center serving children without family linkages indicates need for needs assessments, follow-up activities, measurement of individual child progress,…

  12. Single-frequency lasing of monolithic Ho,Tm:YLF

    NASA Technical Reports Server (NTRS)

    Koch, Grady J.; Deyst, John P.; Storm, Mark E.

    1993-01-01

    Single-frequency lasing in monolithic crystals of holmium-thulium-doped YLF (Ho,Tm:YLF) is reported. A maximum single-frequency output power of 6 mW at a wavelength of 2.05 microns is demonstrated. Frequency tuning is also described.

  13. Performance of Ho:YAG as a function of temperature

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P.; Gettemy, Donald J.

    1990-01-01

    The performance of two multiply doped Ho:YAG lasers has been characterized as a function of the laser rod temperature. From the experimental results, the dependence of the slope efficiency and threshold on temperature has been extracted. Threshold can be correlated with the occupation of the lower laser level. Implications on the optimum operating temperature are discussed.

  14. 2012 Louisiana "Ho" nursery and infield variety trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three years after selection in the seedling stage of the USDA variety program, superior experimental varieties are assigned permanent “HoCP” or “Ho” numbers. These varieties are then planted in replicated yield trials at SRU’s Ardoyne Farm in Schriever and at the LSU AgCenter’s Iberia Research Stati...

  15. Low temperature magnetic transitions of single crystal HoBi

    SciTech Connect

    Fente, A.; Suderow, H.; Vieira, S.; Nemes, N. M.; Garcia-Hernandez, M.; Budko, Sergei L.; Canfield, Paul C.

    2013-09-04

    We present resistivity, specific heat and magnetization measurements in high quality single crystals of HoBi, with a residual resistivity ratio of 126. We find, from the temperature and field dependence of the magnetization, an antiferromagnetic transition at 5.7 K, which evolves, under magnetic fields, into a series of up to five metamagnetic phases.

  16. The prosecution of Taiwan sexuality researcher and activist Josephine Ho.

    PubMed

    Wang, Ping

    2004-05-01

    In April 2003, following a newspaper report of a hyperlink to a website on bestiality on the Sexuality Databank website of the Center for the Study of Sexualities, National Central University, Taipei, Taiwan, 14 conservative NGOs filed charges against the Center's founder, Josephine Ho, for "propagating obscenities that corrupt traditional values." Ho has been researching sexuality and supporting freedom for marginalised sexual minorities for ten years. In a public statement in response to the charges, she said that the work of scholarly research must not be dictated by prejudice and that differences in sexual values should not be arbitrated by law and should be open for public discussion. As the legal process began in January 2004, Ho's supporters in Taiwan have called for the preservation of the Taiwan Constitutional decree on integrity and autonomy of academic research and freedom of expression on the internet, for the University to resist calls to dismiss Ho from her post, and for respect for freedom of speech and expression and the right to create spaces to educate people about non-normative sexualities. PMID:15242216

  17. Registration of ‘Ho 00-961’ sugarcane

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ho 00-961’ (Reg. No., PI) sugarcane (a complex hybrid of Saccharum officinarum L., S. spontaneum L., S. barberi Jeswiet, and S. sinense Roxb. amend. Jeswiet) was selected by the USDA-ARS Sugarcane Research Unit, and evaluated cooperatively with the Louisiana State University Agricultural Center, an...

  18. 2010 Louisiana "Ho" nursery and infield variety trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three years after selecting in single-stools in the seedling stage, scientists in the SRU’s sugarcane breeding program assign “HoCP” or “Ho” numbers to varieties advanced for further testing. These newly assigned varieties are planted in replicated nursery trials at the SRU’s Ardoyne Farm in Schrie...

  19. Living with ghosts in Hořava-Lifshitz gravity

    NASA Astrophysics Data System (ADS)

    Ramazanov, S.; Arroja, F.; Celoria, M.; Matarrese, S.; Pilo, L.

    2016-06-01

    We consider the branch of the projectable Hořava-Lifshitz model which exhibits ghost instabilities in the low energy limit. It turns out that, due to the Lorentz violating structure of the model and to the presence of a finite strong coupling scale, the vacuum decay rate into photons is tiny in a wide range of phenomenologically acceptable parameters. The strong coupling scale, understood as a cutoff on ghosts' spatial momenta, can be raised up to Λ ˜ 10 TeV. At lower momenta, the projectable Hořava-Lifshitz gravity is equivalent to General Relativity supplemented by a fluid with a small positive sound speed squared (10-42 ≲) c s 2 ≲ 10-20, that could be a promising candidate for the Dark Matter. Despite these advantages, the unavoidable presence of the strong coupling obscures the implementation of the original Hořava's proposal on quantum gravity. Apart from the Hořava-Lifshitz model, conclusions of the present work hold also for the mimetic matter scenario, where the analogue of the projectability condition is achieved by a non-invertible conformal transformation of the metric.

  20. Production and characterization of 166Ho polylactic acid microspheres.

    PubMed

    Yavari, Kamal; Yeganeh, Ehsan; Abolghasemi, Hossein

    2016-01-01

    Microsphere and particle technology with selective transport of radiation represents a new generation of therapeutics. Poly-L-lactic acid (PLLA) microspheres loaded with holmium-166 acetylacetonate ((166)Ho-PLLA-MS) are novel microdevices. In this research, (165)HoAcAc-PLLA microparticles were prepared by the solvent evaporation technique. Microspheres were irradiated at Tehran Research Reactor. The diameter and surface morphologies were characterized by particle sizer and scanning electron microscopy before and after irradiation. The complex stability, radiochemical purity, and in vivo biodistribiotion were checked in the final solution up to 3 days. In this study, (166)Ho-PLLA spherical particles with a smooth surface and diameter of 20-40 µm were obtained, which were stable in vitro and in vivo studies. Neutron irradiation did not damage the particles. The ease with which the PLLA spheres could be made in the optimal size range for later irradiation and their ability to retain the (166)Ho provided good evidence for their potential use in radioembolization. PMID:26691104

  1. 2014 Louisiana "Ho" nursery and infield variety trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the USDA sugarcane variety program, superior experimental varieties are assigned permanent “HoCP” or “Ho” numbers three years after selection in the seedling stage. These varieties are then planted in replicated yield trials at the Sugarcane Research Unit's (SRU) Ardoyne Farm in Schriever and at ...

  2. Effects of carnosine on contractile apparatus Ca²⁺ sensitivity and sarcoplasmic reticulum Ca²⁺ release in human skeletal muscle fibers.

    PubMed

    Dutka, T L; Lamboley, C R; McKenna, M J; Murphy, R M; Lamb, G D

    2012-03-01

    There is considerable interest in potential ergogenic and therapeutic effects of increasing skeletal muscle carnosine content, although its effects on excitation-contraction (EC) coupling in human muscle have not been defined. Consequently, we sought to characterize what effects carnosine, at levels attained by supplementation, has on human muscle fiber function, using a preparation with all key EC coupling proteins in their in situ positions. Fiber segments, obtained from vastus lateralis muscle of human subjects by needle biopsy, were mechanically skinned, and their Ca(2+) release and contractile apparatus properties were characterized. Ca(2+) sensitivity of the contractile apparatus was significantly increased by 8 and 16 mM carnosine (increase in pCa(50) of 0.073 ± 0.007 and 0.116 ± 0.006 pCa units, respectively, in six type I fibers, and 0.063 ± 0.018 and 0.103 ± 0.013 pCa units, respectively, in five type II fibers). Caffeine-induced force responses were potentiated by 8 mM carnosine in both type I and II fibers, with the potentiation in type II fibers being entirely explicable by the increase in Ca(2+) sensitivity of the contractile apparatus caused by carnosine. However, the potentiation of caffeine-induced responses caused by carnosine in type I fibers was beyond that expected from the associated increase in Ca(2+) sensitivity of the contractile apparatus and suggestive of increased Ca(2+)-induced Ca(2+) release. Thus increasing muscle carnosine content likely confers benefits to muscle performance in both fiber types by increasing the Ca(2+) sensitivity of the contractile apparatus and possibly also by aiding Ca(2+) release in type I fibers, helping to lessen or slow the decline in muscle performance during fatiguing stimulation. PMID:22174397

  3. High-pressure polymorphs of iron-rich (Mg, Fe)SiO3 and FeGeO3 perovskite and post-perovskite. Takamitsu Yamanaka1, Wendy L. Mao2, P. Ganesh1, Luke Shulenburger1, Ho-kwang Mao1 and Russell J. Hemley1 1Geophysical Laboratory, Carnegie Institute of Washington, Washington, D.C. 20015 2 Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305

    NASA Astrophysics Data System (ADS)

    Yamanaka, T.; Mao, W. L.; Shulenburger, L.; Ganesh, P.; Mao, H.; Hemley, R. J.

    2010-12-01

    Discovery of a high-pressure post-perovskite phase transition of MgSiO3 opened a new paradigm for understanding the deepest region of the core-mantle boundary and the D’’ region. The structure was found to be Cmcm space group as same structure as CaIrO3. However, we discovered a new structure for the post-perovskite phase of iron rich magnesium silicate at the Earth’s core-mantle boundary. The different structure will lead to better understanding of existing anomalies in the shear wave velocities at the D’’ layer. Our discovery of a new structure also gives a much simpler picture of the spin state of the D’’ layer. We used a combination of high-pressure/high-temperature experimental techniques including X-ray diffraction and X-ray emission spectra in conjunction with first-principles calculations to study the Fe-rich phase of magnesium silicate. We find a new structure with a Pmcm space group which differs distinctly from the assumed CaIrO3 structure in which it has two distinct sites for the metal ions (iron and magnesium) as opposed to having a random distribution of the metal ions which would make the two sites crystallographically equivalent. This result is also of primary importance in the understanding of the spin state of the silicate phase. From X-ray emission studies we find that iron exists in two distinct populations, one with high spin and one with low spin rather than being in an intermediate spin state (J.F. Lin et al, 2008). Furthermore, the abundance of these populations is equivalent to the site occupancies found through the structural refinement of the X-ray diffraction data. These findings have important implications for Earth’s D” layer and core-mantle boundary,. Because the stabilities of perovskite structures are closely related to the ratio of the radii composing ABO3 compounds, the tolerance factor can be a good indicator to predict high-pressure sequence of transformation and decompression process of ABO3 compounds. In

  4. Role of Ca2+ channels in the ability of membrane depolarization to prevent neuronal death induced by trophic-factor deprivation: evidence that levels of internal Ca2+ determine nerve growth factor dependence of sympathetic ganglion cells.

    PubMed Central

    Koike, T; Martin, D P; Johnson, E M

    1989-01-01

    Sympathetic neurons depend on nerve growth factor (NGF) for their survival both in vivo and in vitro; these cells die upon acute deprivation of NGF. We studied the effects of agents that cause membrane depolarization on neuronal survival after NGF deprivation. High-K+ medium (greater than or equal to 33 mM) prevented cell death; the effect of K+ was dose-dependent (EC50 = 21 mM). The protection by high K+ was abolished either by withdrawal of extracellular Ca2+ or by preloading the cells with a Ca2+ chelator. The involvement of Ca2+ flux across membranes in high-K+ saving of NGF-deprived neurons was also supported by experiments using Ca2+-channel antagonists and agonists. The Ca2+ antagonists nimodipine and nifedipine effectively blocked the survival-promoting effect of high K+. The Ca2+ agonists Bay K 8644 and (S)-202-791 did not by themselves save neurons from NGF deprivation but did strongly augment the effect of high K+; EC50 was shifted from 21 mM to 13 mM. These data suggest that dihydropyridine-sensitive L-type Ca2+ channels play a major role in the high-K+ saving. The depolarizing agents choline (EC50 = 1 mM) and carbamoylcholine (EC50 = 1 microM), acting through nicotinic cholinergic receptors, also rescued NGF-deprived neurons. The saving effect of nicotinic agonists was not blocked by withdrawal of extracellular Ca2+ but was counteracted by a chelator of intracellular Ca2+, suggesting the possible involvement of Ca2+ release from internal stores. Based on these findings we propose a "Ca2+ set-point hypothesis" for the degree of trophic-factor dependence of sympathetic neurons in vitro. Images PMID:2548215

  5. The mechanism of the decrease in cytosolic Ca2+ concentrations induced by angiotensin II in the high K(+)-depolarized rabbit femoral artery.

    PubMed

    Ushio-Fukai, M; Yamamoto, H; Nishimura, J; Hirano, K; Kanaide, H

    2000-02-01

    1. Using front-surface fluorometry of fura-2-loaded strips, and measuring the transmembrane 45Ca2+ fluxes of ring preparations of the rabbit femoral artery, the mechanism underlying a sustained decrease in the cytosolic Ca2+ concentration ([Ca2+]i) induced by angiotensin II (AT-II) was investigated. 2. The application of AT-II during steady-state 118 mM K(+)-induced contractions caused a sustained decrease in [Ca2+]i following a rapid and transient increase in [Ca2+]i, while the tension was transiently enhanced. 3. When the intracellular Ca2+ stores were depleted by thapsigargin, the initial rapid and transient increase in [Ca2+]i was abolished, however, neither the sustained decrease in [Ca2+]i nor the enhancement of tension were affected. 4. Depolarization with 118 mM K+ physiological salt solution containing 1.25 mM Ba2+ induced a sustained increase in both the cytosolic Ba2+ concentration ([Ba2+]i) level and tension. However, the application of 10(-6) M AT-II during sustained Ba(2+)-contractions was found to have no effect on [Ba2+]i, but it did enhance tension. 5. After thapsigargin treatment, AT-II neither decreased nor increased the enhanced Ca2+ efflux rate induced by 118 mM K(+)-depolarization, whereas AT-II did increase the enhanced 45Ca2+ influx and the 45Ca2+ net uptake induced by 118 mM K(+)-depolarization. 6. Pretreatment with calphostin-C, partially, but significantly inhibited the decrease in [Ca2+]i induced by AT-II. 7. These findings therefore suggest that AT-II stimulates Ca2+ sequestration into the thapsigargin-insensitive Ca2+ stores, and thus induces a decrease in [Ca2+]i in the high external K(+)-stimulated rabbit femoral artery. PMID:10711341

  6. Isolation of 163Ho from dysprosium target material by HPLC for neutrino mass measurements

    DOE PAGESBeta

    Mocko, Veronika; Taylor, Wayne  A.; Nortier, Francois M.; Engle, Jonathan  W.; Barnhart, Todd  E.; Nickles, Robert  J.; Pollington, Anthony  D.; Kunde, Gerd  J.; Rabin, Michael  W.; Birnbaum, Eva  R.

    2015-04-29

    The rare earth isotope 163Ho is of interest for neutrino mass measurements. This report describes the isolation of 163Ho from a proton-irradiated dysprosium target and its purification. A Dy metal target was irradiated with 16 MeV protons for 10 h. After target dissolution, 163Ho was separated from the bulk Dy via cation-exchange high performance liquid chromatography using 70 mmol dm–3 α-hydroxyisobutyric acid as the mobile phase. Subsequent purification of the collected Ho fraction was performed to remove the α-hydroxyisobutyrate chelating agent and to concentrate the Ho in a low ionic strength aqueous matrix. The final solution was characterized by MC-ICP-MSmore » to determine the 163Ho/165Ho ratio, 163Ho and the residual Dy content. The HPLC purification process resulted in a decontamination factor 1.4E5 for Dy. As a result, the isolated Ho fraction contained 24.8 ±1.3 ng of 163Ho corresponding to holmium recovery of 72 ± 3%.« less

  7. Reversal of HO-1 related cytoprotection with increased expression is due to reactive iron.

    PubMed

    Suttner, D M; Dennery, P A

    1999-10-01

    It is often postulated that the cytoprotective nature of heme oxygenase (HO-1) explains the inducible nature of this enzyme. However, the mechanisms by which protection occurs are not verified by systematic evaluation of the physiological effects of HO. To explain how induction of HO-1 results in protection against oxygen toxicity, hamster fibroblasts (HA-1) were stably transfected with a tetracycline response plasmid containing the full-length rat HO-1 cDNA construct to allow for regulation of gene expression by varying concentrations of doxycycline (Dox). Transfected cells were exposed to hyperoxia (95% O(2)/5% CO2) for 24 h and several markers of oxidative injury were measured. With varying concentrations of Dox, HO activity was regulated between 3- and 17-fold. Despite cytoprotection with low (less than fivefold) HO activity, high levels of HO-1 expression (greater than 15-fold) were associated with significant oxygen cytotoxicity. Levels of non-heme reactive iron correlated with cellular injury in hyperoxia whereas lower levels of heme were associated with cytoprotection. Cellular levels of cyclic GMP and bilirubin were not significantly altered by modification of HO activity, precluding a substantial role for activation of guanylate cyclase by carbon monoxide or for accumulation of bile pigments in the physiological consequences of HO-1 overexpression. Inhibition of HO activity or chelation of cellular iron prior to hyperoxic exposure decreased reactive iron levels in the samples and significantly reduced oxygen toxicity. We conclude that there is a beneficial threshold of HO-1 overexpression related to the accumulation of reactive iron released in the degradation of heme. Therefore, despite the ready induction of HO-1 in oxidant stress, accumulation of reactive iron formed makes it unlikely that exaggerated expression of HO-1 is a cytoprotective response. PMID:10506583

  8. Microstructures and Thermal Properties of Mg-Sn-Ca Alloys: Casts and Extrusions

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Han; Choi, Jeong-Won; Kim, Yong-Ho; Yoo, Hyo-Sang; Woo, Kee-Do; Lee, Seong-Hee; Son, Hyeon-Taek

    2015-11-01

    Microstructure and thermal properties of Mg-(3 mass% or 5 mass%) Sn-2 mass% Ca alloys as casts and extrusions have been investigated with different ram speeds and extrusion temperatures. Mg-(3 mass% or 5 mass%) Sn-2 mass% Ca alloys are composed of \\upalpha -Mg, MgSnCa, and {Mg}2{Ca} phases. By adding Sn content from 3 mass% to 5 mass%, the MgSnCa phase is increased and the {Mg}2{Ca} phase is decreased. During hot extrusion, the average grain sizes are increased with increasing ram speed and temperature. The ultimate tensile strength ( UTS) and elongation for the Mg-5Sn-2Ca alloy at 2.3 {mm}{\\cdot }{s}^{-1} are 227.73 MPa and 18.43 %, respectively. With increasing extrusion ram speed, the UTS and elongation for the Mg-5Sn-2Ca alloy are remarkably decreased to 215.95 MPa, 206.33 MPa, and 14.74 %, 6.88 %, respectively. The thermal conductivity for the Mg-3Sn-2Ca alloy is dramatically improved, compared to commercialized Mg alloys such as AZ31 and AZ91 due to formation of MgSnCa and {Mg}2{Ca} phases.

  9. CA125 in Ovarian Cancer

    PubMed Central

    Urban, Nicole

    2009-01-01

    Summary Twenty five years after its discovery, circulating CA125 antigen is recommended for clinical use in the US for ovarian cancer (OC) screening of high risk women with ovaries despite its limited sensitivity and specificity. Recent findings suggest that CA125 might also serve as a predictive marker for pre-invasive OC. Methods to quantify circulating CA125 evolved towards sensitive and reliable double determinant ELISA assays. The CA125 gene, MUC16, was cloned 20 years after the protein discovery and revealed a very complex and unusual glycoprotein structure suggesting an immunological role. Recent evidence points toward CA125 function in the induction of materno-fetal tolerance through the alteration of NK phenotype. Two receptors for CA125 have been described: mesothelin and galectin-1. The specific location and functional proprieties of CA125 make it a therapeutic target of choice; clinical trials have demonstrated that anti-CA125 injections are well tolerated and suggest a potential survival benefit. PMID:20477371

  10. Anion Permeation in Ca2+-Activated Cl− Channels

    PubMed Central

    Qu, Zhiqiang; Hartzell, H. Criss

    2000-01-01

    Ca2+-activated Cl channels (ClCaCs) are an important class of anion channels that are opened by increases in cytosolic [Ca2+]. Here, we examine the mechanisms of anion permeation through ClCaCs from Xenopus oocytes in excised inside-out and outside-out patches. ClCaCs exhibited moderate selectivity for Cl over Na: PNa/PCl = 0.1. The apparent affinity of ClCaCs for Cl was low: Kd = 73 mM. The channel had an estimated pore diameter >0.6 nm. The relative permeabilities measured under bi-ionic conditions by changes in Erev were as follows: C(CN)3 > SCN > N(CN)2 > ClO4 > I > N3 > Br > Cl > formate > HCO3 > acetate = F > gluconate. The conductance sequence was as follows: N3 > Br > Cl > N(CN)2 > I > SCN > COOH > ClO4 > acetate > HCO3 = C(CN)3 > gluconate. Permeant anions block in a voltage-dependent manner with the following affinities: C(CN)3 > SCN = ClO4 > N(CN)2 > I > N3 > Br > HCO3 > Cl > gluconate > formate > acetate. Although these data suggest that anionic selectivity is determined by ionic hydration energy, other factors contribute, because the energy barrier for permeation is exponentially related to anion hydration energy. ClCaCs exhibit weak anomalous mole fraction behavior, implying that the channel may be a multi-ion pore, but that ions interact weakly in the pore. The affinity of the channel for Ca2+ depended on the permeant anion at low [Ca2+] (100–500 nM). Apparently, occupancy of the pore by a permeant anion increased the affinity of the channel for Ca2+. The current was strongly dependent on pH. Increasing pH on the cytoplasmic side decreased the inward current, whereas increasing pH on the external side decreased the outward current. In both cases, the apparent pKa was voltage-dependent with apparent pKa at 0 mV = ∼9.2. The channel may be blocked by OH− ions, or protons may titrate a site in the pore necessary for ion permeation. These data demonstrate that the permeation properties of ClCaCs are different from those of CFTR or ClC-1, and provide

  11. Functionalized zinc oxide nanorod with ionophore-membrane coating as an intracellular Ca2+ selective sensor

    NASA Astrophysics Data System (ADS)

    Asif, M. H.; Fulati, A.; Nur, O.; Willander, M.; Brännmark, Cecilia; Strâlfors, Peter; Börjesson, Sara I.; Elinder, Fredrik

    2009-07-01

    The tip of a borosilicate glass capillary with functionalized hexagonal ZnO nanorods was used to make a sensitive electrochemical intracellular Ca2+ sensor. To adjust the sensor for Ca2+ measurements with sufficient selectivity and stability, polyvinylchloride membrane containing Ca2+ ionophores were coated on the surface. The membrane covered ZnO nanorods exhibited a Ca2+-dependent electrochemical potential difference versus an Ag/AgCl reference electrode. The potential difference was linear over a large concentration range (100 nM-10 mM). The measurements of Ca2+ concentrations using our ZnO nanorods sensor in human fat cells or in frog egg cells were consistent with values of Ca2+ concentrations reported in the literature. This nanoelectrode device paves the way to measurements of intracellular biochemical species in specific locations within single living cells.

  12. Dynamic buffering of mitochondrial Ca2+ during Ca2+ uptake and Na+-induced Ca2+ release

    PubMed Central

    Blomeyer, Christoph A.; Bazil, Jason N.; Stowe, David F.; Pradhan, Ranjan K.; Dash, Ranjan K.; Camara, Amadou K. S.

    2014-01-01

    In cardiac mitochondria, matrix free Ca2+ ([Ca2+]m) is primarily regulated by Ca2+ uptake and release via the Ca2+ uniporter (CU) and Na+/Ca2+ exchanger (NCE) as well as by Ca2+ buffering. Although experimental and computational studies on the CU and NCE dynamics exist, it is not well understood how matrix Ca2+ buffering affects these dynamics under various Ca2+ uptake and release conditions, and whether this influences the stoichiometry of the NCE. To elucidate the role of matrix Ca2+ buffering on the uptake and release of Ca2+, we monitored Ca2+ dynamics in isolated mitochondria by measuring both the extra-matrix free [Ca2+] ([Ca2+]e) and [Ca2+]m. A detailed protocol was developed and freshly isolated mitochondria from guinea pig hearts were exposed to five different [CaCl2] followed by ruthenium red and six different [NaCl]. By using the fluorescent probe indo-1, [Ca2+] and [Ca2+e]m were spectrofluorometrically quantified, and the stoichiometry of the NCE was determined. In addition, we measured NADH, membrane potential, matrix volume and matrix pH to monitor Ca2+-induced changes in mitochondrial bioenergetics. Our [Ca2+]e and [Ca2+]m measurements demonstrate that Ca2+ uptake and release do not show reciprocal Ca2+ dynamics in the extra-matrix and matrix compartments. This salient finding is likely caused by a dynamic Ca2+ buffering system in the matrix compartment. The Na+ - induced Ca2+ release demonstrates an electrogenic exchange via the NCE by excluding an electroneutral exchange. Mitochondrial bioenergetics were only transiently affected by Ca2+ uptake in the presence of large amounts of CaCl2, but not by Na+- induced Ca2+ release. PMID:23225099

  13. The influence of metal-ion binding on the structure and surface composition of Sonic Hedgehog: a combined classical and hybrid QM/MM MD study.

    PubMed

    Hitzenberger, Manuel; Hofer, Thomas S

    2016-08-10

    In this work, the influence of the metal ions present in vertebrate Sonic Hedgehog was assessed by a series of molecular mechanics molecular dynamics simulations with differing ionic compositions. The obtained data suggest that Ca(ii) binding has a very distinct influence on the composition of the protein surface surrounding the binding site by shaping several ionic interactions with negatively charged sidechains that otherwise would be pointing towards the solvent, repelling potential ligands. Furthermore, the Ca(ii) ions play an important role in the stability of the loop regions where they are coordinated. In contrast, the removal of the Zn(ii) ion results in no noticeable destabilization of its chemical surrounding, however, it is shown that the destabilizing effect of removed Ca(ii) ions is amplified if Zn(ii) is absent as well. Furthermore, a quantum mechanical/molecular mechanical (QM/MM) molecular dynamics simulation of Sonic Hedgehog with special focus on the Zn(ii) binding site has been conducted. The results indicate that QM/MM in contrast to pure MM accurately reproduces structural features also found by experimental studies and therefore is able to provide credible predictions not only of the dynamical properties of the studied system but also of protein-ligand interactions at the metal ion binding site. PMID:27452578

  14. Simultaneous, in situ measurements of OH, HO2, O3, and H2O - A test of modeled stratospheric HO(x) chemistry

    NASA Technical Reports Server (NTRS)

    Wennberg, P. O.; Stimpfle, R. M.; Weinstock, E. M.; Dessler, A. E.; Lloyd, S. A.

    1990-01-01

    Simultaneous, in situ measurements of OH, HO2, H2O, and O3 from 37-23 km are reported. The partitioning between OH and HO2 and the total HO(x) concentration are compared with expected steady-state values. The ratio of HO2 to OH varies from less than 2 at 36 km to more than 3 at 25 km; in the lower stratosphere this ratio is nearly a factor of two less than predicted. The data are used to calculate HO(x) production and loss rates. The measured HO(x) mixing ratio is consistent with production dominated by the reaction of O(1D) with H2O, and loss controlled by NOy below 28 km and HO(x) above 30 km. The steady-state concentration of H2O2 is inferred from the measured HO2 concentration and calculated photolysis rate. The maximum H2O2 mixing ratio (at 33 km) is predicted to be less than 0.2 ppb.

  15. Registration of Three High Fiber Sugar Cane Varieties, L 79-1002, HoCP 91-552 AND Ho 00-961, for Biofuels Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High fiber sugarcane (Saccharum spp. hybrids) varieties, or energy canes, have been shown to be a viable feedstock for biofuel applications. Three high fiber sugarcane varieties, L 79-1002, HoCP 91-552 and Ho 00-961, were released in April 2007 for commercial biofuel production. L 79-1002 averaged 2...

  16. Characterization of the ER-Targeted Low Affinity Ca(2+) Probe D4ER.

    PubMed

    Greotti, Elisa; Wong, Andrea; Pozzan, Tullio; Pendin, Diana; Pizzo, Paola

    2016-01-01

    Calcium ion (Ca(2+)) is a ubiquitous intracellular messenger and changes in its concentration impact on nearly every aspect of cell life. Endoplasmic reticulum (ER) represents the major intracellular Ca(2+) store and the free Ca(2+) concentration ([Ca(2+)]) within its lumen ([Ca(2+)]ER) can reach levels higher than 1 mM. Several genetically-encoded ER-targeted Ca(2+) sensors have been developed over the last years. However, most of them are non-ratiometric and, thus, their signal is difficult to calibrate in live cells and is affected by shifts in the focal plane and artifactual movements of the sample. On the other hand, existing ratiometric Ca(2+) probes are plagued by different drawbacks, such as a double dissociation constant (Kd) for Ca(2+), low dynamic range, and an affinity for the cation that is too high for the levels of [Ca(2+)] in the ER lumen. Here, we report the characterization of a recently generated ER-targeted, Förster resonance energy transfer (FRET)-based, Cameleon probe, named D4ER, characterized by suitable Ca(2+) affinity and dynamic range for monitoring [Ca(2+)] variations within the ER. As an example, resting [Ca(2+)]ER have been evaluated in a known paradigm of altered ER Ca(2+) homeostasis, i.e., in cells expressing a mutated form of the familial Alzheimer's Disease-linked protein Presenilin 2 (PS2). The lower Ca(2+) affinity of the D4ER probe, compared to that of the previously generated D1ER, allowed the detection of a conspicuous, more clear-cut, reduction in ER Ca(2+) content in cells expressing mutated PS2, compared to controls. PMID:27598166

  17. /sup 45/Ca distribution and transport in saponin skinned vascular smooth muscle

    SciTech Connect

    Stout, M.A.; Diecke, F.P.

    1983-04-01

    /sup 45/Ca distribution and transport were studied in chemically skinned strips of caudal artery from Kyoto Wistar rats. Sarcolemmal membranes were made hyperpermeable by exposure for 60 min to solutions containing 0.1 mg/ml of saponin. Skinned helical strips responded with graded contractions to changes in ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid buffered free Ca solutions (10(-7) to 10(-5) M) and were sensitive to the Mg-ATP concentration. Tissues loaded in the presence of 10(-7) M Ca contracted in response to 10 mM caffeine. These experiments indicate the strips are skinned and possess a functional regulatory and contractile system and an intact Ca sequestering system. /sup 45/Ca distributes in three compartments in skinned caudal artery strips. The Ca contents of two components are linear functions of the Ca-ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid concentration and desaturate at rapid rates. They correspond to the extracellular and cytoplasmic spaces. A significantly smaller component releases Ca at comparatively slower rates. /sup 45/Ca uptake by the slow component consists of an ATP-dependent and an ATP-independent fraction. The /sup 45/Ca content of the ATP-dependent fraction is a function of the free Ca concentration and is independent of the Ca-ethylene glycol bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid concentration. Its content was enhanced by oxalate and was abolished by Triton X-100 skinning solutions. The ATP-independent component was not affected by Triton X-100 skinning and may represent Ca binding to cytoplasmic molecules and structures. The sequestered Ca was released with caffeine or Ca but not by epinephrine. The observations indicate that the sarcoplasmic reticulum and mitochondria of vascular smooth muscle strips skinned with saponin retain their functional integrity after saponin skinning.

  18. Effects of Ca2+ or Na+ on metallothionein expression in tilapia larvae (Oreochromis mossambicus) exposed to cadmium or copper.

    PubMed

    Wu, S M; Ho, Y-C; Shih, M J

    2007-02-01

    The objectives of this study were to try to determine the reasons of the external Ca(2+) and Na(+) enhancement of Cd(2+) and Cu(2+) resistance in fish. Tilapia larvae at 3 days posthatch were exposed to (A) 0 (control), 40 microg/L Cd(2+), 40 microg/L Cd(2+) + 2 mM Ca(2+) (Cd/hyper-Ca), and 2 mM Ca(2+) or (B) 0 (control), 75 microg/L Cu(2+), 75 microg/L Cu(2+) + 0.52 mM Na(+) (Cu/hyper-Na), and 0.52 mM Na(+). After 48 hours, results indicated that (1) Cd/hyper-Ca and Cu/hyper-Na treatments showed decreased growth inhibition induced by the metals; (2) metal accumulation in Cd/hyper-Ca-treated larvae was lower compared with those exposed only to Cd; and (3) metallothionein (MT) expression was significantly higher in Cu/hyper-Na-treated larvae than in the group treated with Cu only. Taking all of this into account, either supplementary Ca(2+) or Na(+) in ambient water may help fish to maintain Ca(2+) or Na(+) homeostasis, which could decrease metal accumulation and its detrimental effects. Consequently, the fish increase MT expression and retard the growth inhibition caused by metals. PMID:17165107

  19. Superiority of 10-mm-wide Balloon over 8-mm-wide Balloon in Papillary Dilation for Bile Duct Stones: A Matched Cohort Study

    PubMed Central

    Akiyama, Dai; Hamada, Tsuyoshi; Isayama, Hiroyuki; Nakai, Yousuke; Tsujino, Takeshi; Umefune, Gyotane; Takahara, Naminatsu; Mohri, Dai; Kogure, Hirofumi; Matsubara, Saburo; Ito, Yukiko; Yamamoto, Natsuyo; Sasahira, Naoki; Tada, Minoru; Koike, Kazuhiko

    2015-01-01

    Background/Aims: Endoscopic papillary balloon dilation (EPBD) is a possible alternative to endoscopic sphincterotomy (EST) for common bile duct (CBD) stones. To date, 10- and 8-mm EPBD have not been fully compared. Patients and Methods: Patients who underwent EPBD for CBD stones at two Japanese tertiary care centers between May 1994 and January 2014 were identified. Matched pairs with 10- and 8-mm EPBD were generated. Short- and long-term outcomes were compared between the two groups. Results: A total of 869 patients were identified (61 and 808 patients for 10- and 8-mm EPBD, respectively), and 61 well-balanced pairs were generated. The rate of complete stone removal within a single session was higher in the 10-mm EPBD group than in the 8-mm EPBD group (69% vs. 44%, P < 0.001), and use of lithotripsy was less frequent in the 10-mm EPBD group (23% vs. 56%, P < 0.001). The rates of post-ERCP pancreatitis were similar between the 10- and 8-mm EPBD groups (11% vs. 8%). Cumulative biliary complication-free rates were not statistically different between the two groups: 88% [95% confidence interval (CI): 79–97%] and 94% (95% CI: 88–100%) at 1 year and 69% (95% CI: 56–85%) and 80% (95% CI: 69–93%) at 2 years in the 10- and 8-mm EPBD groups, respectively. In the 10-mm EPBD group, ascending cholangitis was not observed, and pneumobilia was found in 5% of cases during the follow-up period. Conclusions: EPBD using a 10-mm balloon for CBD stones is safe and more effective than 8-mm EPBD. The sphincter function is highly preserved after 10-mm EPBD. PMID:26228364

  20. Stress Analysis on Single Cobalt/Chrome Prosthesis With a 15-mm Cantilever Placed Over 10/13/15-mm-length Implants: A Simulated Photoelastic Model Study.

    PubMed

    Gastaldo, José Fábio Guastelli; Pimentel, Angélica Castro; Gomes, Maria Helena; Sendyk, Wilson Roberto; Laganá, Dalva Cruz

    2015-12-01

    The aim of study was to assess the stress around 10/13/15-mm implants in the mandibular area with a 15-mm cantilevered acrylic-resin-coated prostheses following the application force, using the photoelasticity method. Three photoelastic mandibular models were created containing 10-, 13-, and 15-mm implants in length and 3.75 mm in diameter. The implants had bore internal hex connections and were placed parallel to the intermental region. Abutments with 1-mm high cuffs were placed over the implants, and a single cobalt/chrome metallic prosthesis with a 15-mm cantilever, coated with thermoplastic acrylic resin, was placed on top. Loads of 1.0 and 3.0 bars were applied, and the images were photographed and assessed by photoelasticity method. The greatest stress levels were observed for the 10-mm implants. The stress pattern was the same regardless of implant length; only the magnitude of the stress along the implant body revealed changes. Increased implant length played a role in reducing stress on the investigated area of the model, and the 15-mm implants exhibited the best performance in regard to stress distribution. The highest stress levels were found in the implants closest to the cantilever and the central implant. The longest implants were more favorable in regard to the stress distribution on the peri-implant support structures in the 15-mm cantilevered prosthesis under loads. PMID:24914673

  1. BCL-B (BCL2L10) is overexpressed in patients suffering from multiple myeloma (MM) and drives an MM-like disease in transgenic mice.

    PubMed

    Hamouda, Mohamed-Amine; Jacquel, Arnaud; Robert, Guillaume; Puissant, Alexandre; Richez, Valentine; Cassel, Romeo; Fenouille, Nina; Roulland, Sandrine; Gilleron, Jerome; Griessinger, Emmanuel; Dubois, Alix; Bailly-Maitre, Beatrice; Goncalves, Diogo; Mallavialle, Aude; Colosetti, Pascal; Marchetti, Sandrine; Amiot, Martine; Gomez-Bougie, Patricia; Rochet, Nathalie; Deckert, Marcel; Avet-Loiseau, Herve; Hofman, Paul; Karsenti, Jean-Michel; Jeandel, Pierre-Yves; Blin-Wakkach, Claudine; Nadel, Bertrand; Cluzeau, Thomas; Anderson, Kenneth C; Fuzibet, Jean-Gabriel; Auberger, Patrick; Luciano, Frederic

    2016-08-22

    Multiple myeloma (MM) evolves from a premalignant condition known as monoclonal gammopathy of undetermined significance (MGUS). However, the factors underlying the malignant transformation of plasmocytes in MM are not fully characterized. We report here that Eµ-directed expression of the antiapoptotic Bcl-B protein in mice drives an MM phenotype that reproduces accurately the human disease. Indeed, with age, Eµ-bcl-b transgenic mice develop the characteristic features of human MM, including bone malignant plasma cell infiltration, a monoclonal immunoglobulin peak, immunoglobulin deposit in renal tubules, and highly characteristic bone lytic lesions. In addition, the tumors are serially transplantable in irradiated wild-type mice, underlying the tumoral origin of the disease. Eµ-bcl-b plasmocytes show increased expression of a panel of genes known to be dysregulated in human MM pathogenesis. Treatment of Eµ-bcl-b mice with drugs currently used to treat patients such as melphalan and VELCADE efficiently kills malignant plasmocytes in vivo. Finally, we find that Bcl-B is overexpressed in plasmocytes from MM patients but neither in MGUS patients nor in healthy individuals, suggesting that Bcl-B may drive MM. These findings suggest that Bcl-B could be an important factor in MM disease and pinpoint Eµ-bcl-b mice as a pertinent model to validate new therapies in MM. PMID:27455953

  2. Local and cellular Ca2+ transients in smooth muscle of pressurized rat resistance arteries during myogenic and agonist stimulation.

    PubMed

    Miriel, V A; Mauban, J R; Blaustein, M P; Wier, W G

    1999-08-01

    1. Confocal laser scanning microscopy was used to visualize Ca2+ transients in the vascular smooth muscle cells (VSMC) of intact, pressurized rat mesenteric resistance arteries loaded with fluorescent calcium indicators. Vasoconstriction was assessed by measuring inner arterial diameter. All arteries were studied at 70 mmHg intralumenal pressure and 37 C. 2. In the control condition of myogenic tone the arteries were constricted to 62 % (n = 10) of their passive diameter (p.d.). The [Ca2+]i in most VSMC of these arteries was constant over time. In a small percentage (< 10 %) of cells in each artery, [Ca2+]i oscillated regularly. Local calcium transients (Ca2+ sparks) were observed in five arteries studied with confocal linescan imaging. 3. Activation of alpha-adrenoceptors by phenylephrine (PE, 1.0 microM) induced further vasoconstriction of pressurized arteries (to 27 % of p.d.). In this condition, [Ca2+]i oscillations were prominent in a large percentage (83 %) of the VSMC. The Ca2+ oscillations ranged in frequency from 4 to 22 min-1, and were usually asynchronous between cells. 4. High [KCl]o (65 mM) induced nearly comparable vasoconstriction to PE (37 % of p.d.) but [Ca2+]i oscillated in only about 13 % of cells in each artery. 5. Block of L-type Ca2+ channels (with nifedipine) in arteries activated by PE caused nearly full vasodilatation, but did not abolish the Ca2+ oscillations. Subsequent block of the sarcoplasmic reticulum Ca2+ pump (with cyclopiazonic acid) abolished Ca2+ oscillations in all cells. 6. We conclude that Ca2+ entering VSMC via L-type Ca2+ channels has an obligatory role in force development, both in myogenic tone and during alpha1-adrenoceptor activation. The oscillatory pattern of [Ca2+]i that persists in the absence of Ca2+ entry via L-type Ca2+ channels is ineffective in activating contraction. PMID:10420017

  3. Enhancement by T-type Ca2+ currents of odor sensitivity in olfactory receptor cells.

    PubMed

    Kawai, F; Miyachi, E

    2001-05-15

    Mechanisms underlying action potential initiation in olfactory receptor cells (ORCs) during odor stimulation were investigated using conventional and dynamic patch-clamp recording techniques. Under current-clamp conditions, action potentials generated by a least effective odor-induced depolarization were almost completely blocked by 0.1 mm Ni(2+), a T-type Ca(2+) channel blocker, but not by 0.1 mm Cd(2+), a high voltage-activated Ca(2+) channel blocker. Under voltage-clamp conditions, depolarizing voltage steps induced a fast transient inward current, which consisted of Na(+) (I(Na)) and T-type Ca(2+) (I(Ca,T)) currents. The amplitude of I(Ca,T) was approximately one-fourth of that of I(Na) (0.23 +/- 0.03, mean +/- SEM). Because both I(Na) and I(Ca,T) are known to show rapid inactivation, we examined how much I(Na) and I(Ca,T) are activated during the gradually depolarizing initial phase of receptor potentials. The ratio of I(Ca,T)/I(Na) during a ramp depolarization at the slope of 0.5 mV/msec was 0.56 +/- 0.03. Using the dynamic patch-clamp recording technique, we also recorded I(Ca,T) and I(Na) during the generation of odor-induced action potentials. This ratio of I(Ca,T)/I(Na) was 0.54 +/- 0.04. These ratios were more than twice as large as that (0.23) obtained from the experiment using voltage steps, suggesting that I(Ca,T) carries significant amount of current to generate the action potentials. We conclude that I(Ca,T) contributes to enhance odor sensitivity by lowering the threshold of spike generation in ORCs. PMID:11319242

  4. Degradation of poly(3-hydroxyoctanoic acid) [P(3HO)] by bacteria: Purification and properties of a P(3HO) depolymerase from Pseudomonas fluorescens GK13

    SciTech Connect

    Schirmer, A.; Jendrossek, D.; Schlegel, H.G. )

    1993-04-01

    Poly(3-hydroxyoctanoic acid)[P(3HO)] and other poly(hydroxyalkanoic acids) PHA are widespread bacterial storage compounds of carbon and reducing power. They are biodegradable to carbon dioxide and water, and both aerobic and anaerobic P(3HB)-degradable bacteria are widely distributed in various ecosytems: soil, activated sludge, lake water and air, sea water, estuarine sediment, and anaerobic sewage sludge. This study describes the isolation and characterization of P(3HO) degrading bacteria: Alcaligenes eutrophus, Comamonas violaceum, Pseudomonas citronellolis, and P. fluorescenes (2 strains). The authors also describe purified P(3HO) depolymerase and compared it to PHB and PHA deploymerases. P(3HO) depolymerase activity was found not only in the sulture supernatant but also in the soluble fraction and membrane fractions of P(3HO) grown cells.39 refs.,5 figs.,3 tabs.

  5. Dantrolene suppresses spontaneous Ca2+ release without altering excitation-contraction coupling in cardiomyocytes of aged mice

    PubMed Central

    Roberts, Cale J.; Gibson, Anne K.; Hanft, Laurin M.; McDonald, Kerry S.; Segal, Steven S.

    2014-01-01

    Cardiac dysfunction in the aged heart reflects abnormalities in cardiomyocyte Ca2+ homeostasis including altered Ca2+ cycling through the sarcoplasmic reticulum (SR). The ryanodine receptor antagonist dantrolene exerts antiarrhythmic effects by preventing spontaneous diastolic Ca2+ release from the SR. We tested the hypothesis that dantrolene prevents spontaneous Ca2+ release without altering excitation-contraction coupling in aged myocardium. Left ventricular cardiomyocytes isolated from young (3 to 4 mo) and aged (24–26 mo) C57BL/6 mice were loaded with the Ca2+ indicator fluo-4. Amplitudes of action potential-induced Ca2+ transients at 1-Hz pacing were similar between young and aged mice, yet cell shortening was impaired in aged mice. Isoproterenol (1 μM) increased Ca2+ transient amplitude and cell shortening to identical levels in young and aged; dantrolene (1 μM) had no effect on Ca2+ transients or cell shortening during pacing. Under Ca2+ overload conditions induced with 10 mM extracellular Ca2+ concentration, spontaneous Ca2+ waves were of diminished amplitude and associated with lower SR Ca2+ content in aged versus young mice. Despite no effect in young mice, dantrolene increased SR Ca2+ content and Ca2+ wave amplitude in aged mice. In the presence of isoproterenol following rest from 1-Hz pacing, Ca2+ spark frequency was elevated in aged mice, yet the time to spontaneous Ca2+ wave was similar between young and aged mice; dantrolene decreased Ca2+ spark frequency and prolonged the time to Ca2+ wave onset in aged mice with no effect in young mice. Thus dantrolene attenuates diastolic Ca2+ release in the aged murine heart that may prove useful in preventing cardiac dysfunction. PMID:25038147

  6. Comparison of Surgically-induced Astigmatism after Combined Phacoemulsification and 23-Gauge Vitrectomy: 2.2-mm vs. 2.75-mm Cataract Surgery

    PubMed Central

    Kim, Yong-Kyu; Kim, Yong Woo; Park, Kyu Hyung

    2014-01-01

    Purpose The 2.2-mm microincision cataract surgery and small-gauge vitrectomy system is known to result in less surgically-induced astigmatism (SIA) in comparison to conventional surgical methods. We compared the amounts of SIA after combined phacoemulsification and 23-gauge transconjunctival sutureless vitrectomy (23G-TSV) using the 2.2-mm microincision and 2.75-mm standard incision methods. Methods We studied 59 patients (61 eyes) who underwent combined phacoemulsification and 23G-TSV from November 2008 to September 2012. Twenty-eight patients (28 eyes) underwent 2.2-mm microincision coaxial phacoemulsification, and 31 patients (33 eyes) underwent 2.75-mm standard incision phacoemulsification. SIA was evaluated using Naeser's polar method with the simulated keratometric values obtained from corneal topography. Preoperative and 1-week and 1-month postoperative KP (Naeser's polar value along the specific axis) and ΔKP values were compared between the 2.2-mm microincision and 2.75-mm standard incision groups. Results One week after surgery, both groups exhibited similar amounts of SIA (-ΔKP[120], 0.40 ± 0.41 vs. 0.51 ± 0.56 diopters [D]; p = 0.390). One month after surgery, however, the amount of SIA was significantly smaller in the 2.2-mm microincision group as compared to the 2.75-mm standard incision group (-ΔKP[120], 0.31 ± 0.54 vs. 0.56 ± 0.42 D; p = 0.045). Conclusions In combined phacoemulsification with 23G-TSV, 2.2-mm microincision coaxial phacoemulsification induces less SIA than does 2.75-mm standard coaxial phacoemulsification. PMID:24688255

  7. Protective effect of antioxidants against sarcoplasmic reticulum (SR) oxidation by Fenton reaction, however without prevention of Ca-pump activity.

    PubMed

    Voss, Peter; Engels, Martina; Strosova, Miriam; Grune, Tilman; Horakova, Lubica

    2008-10-01

    The Ca(2+)-ATPase of the sarcoplasmic reticulum (SERCA) of rabbit skeletal muscle was oxidized by Fe2+/H2O2/ascorbic acid (AA), a system which generates HO(.) radicals according to the Fenton reaction: (Fe2(+)+H2O2-->HO(.)+OH(-)+Fe(3+)) under conditions similar to the pathological state of inflammation. Under these conditions, when hydroxyl-radicals and/or ferryl-radicals are generated, a 50% decrease of the SERCA activity was observed, a significant decrease of SH groups and an increase of protein carbonyl groups and lipid peroxidation were identified. Two new bands, time dependent in density, appeared in the SERCA protein electrophoresis after incubation with the Fenton system (at approximately 50 and 75kDa), probably due to structural changes as supported also by trypsin digestion. Immunoblotting of DNPH derivatized protein bound carbonyls detected a time dependent increase after incubation of SERCA with the Fenton system. Trolox and the pyridoindole stobadine (50microM) protected SR against oxidation induced via the Fenton system by preventing SH group oxidation and lipid peroxidation. Pycnogenol((R)) and EGb761 (40microg/ml) protected SERCA in addition against protein bound carbonyl formation. In spite of the antioxidant effects, trolox and stobadine were not able to prevent a decrease in the SERCA Ca(2+)-ATPase activity. Pycnogenol and EGb761 even enhanced the decrease of the Ca(2+)-ATPase activity induced by the Fenton system, probably by secondary oxidative reactions. PMID:18692562

  8. Small Molecule Inhibitors of Ca(2+)-S100B Reveal Two Protein Conformations.

    PubMed

    Cavalier, Michael C; Ansari, Mohd Imran; Pierce, Adam D; Wilder, Paul T; McKnight, Laura E; Raman, E Prabhu; Neau, David B; Bezawada, Padmavani; Alasady, Milad J; Charpentier, Thomas H; Varney, Kristen M; Toth, Eric A; MacKerell, Alexander D; Coop, Andrew; Weber, David J

    2016-01-28

    The drug pentamidine inhibits calcium-dependent complex formation with p53 ((Ca)S100B·p53) in malignant melanoma (MM) and restores p53 tumor suppressor activity in vivo. However, off-target effects associated with this drug were problematic in MM patients. Structure-activity relationship (SAR) studies were therefore completed here with 23 pentamidine analogues, and X-ray structures of (Ca)S100B·inhibitor complexes revealed that the C-terminus of S100B adopts two different conformations, with location of Phe87 and Phe88 being the distinguishing feature and termed the "FF-gate". For symmetric pentamidine analogues ((Ca)S100B·5a, (Ca)S100B·6b) a channel between sites 1 and 2 on S100B was occluded by residue Phe88, but for an asymmetric pentamidine analogue ((Ca)S100B·17), this same channel was open. The (Ca)S100B·17 structure illustrates, for the first time, a pentamidine analog capable of binding the "open" form of the "FF-gate" and provides a means to block all three "hot spots" on (Ca)S100B, which will impact next generation (Ca)S100B·p53 inhibitor design. PMID:26727270

  9. Small Molecule Inhibitors of Ca2+-S100B Reveal Two Protein Conformations

    PubMed Central

    Cavalier, Michael C.; Ansari, Mohd. Imran; Pierce, Adam D.; Wilder, Paul T.; McKnight, Laura E.; Raman, E. Prabhu; Neau, David B.; Bezawada, Padmavani; Alasady, Milad J.; Charpentier, Thomas H.; Varney, Kristen M.; Toth, Eric A.; MacKerell, Alexander D.; Coop, Andrew; Weber, David J.

    2016-01-01

    The drug pentamidine inhibits calcium-dependent complex formation with p53 (CaS100B•p53) in malignant melanoma (MM), and restores p53 tumor suppressor activity in vivo. However, off-target effects associated with this drug were problematic in MM patients. Structure-activity relationship (SAR) studies were therefore completed here with 23 pentamidine analogues, and X-ray structures of CaS100B•inhibitor complexes revealed that the C-terminus of S100B adopts two different conformations, with location of Phe-87 and Phe-88 being the distinguishing feature and termed the “FF-Gate”. For symmetric pentamidine analogues (CaS100B•5a, CaS100B•6b) a channel between Sites 1 and 2 on S100B was occluded by residue Phe-88, but for an asymmetric pentamidine analogue (CaS100B•17), this same channel was open. The CaS100B•17 structure illustrates, for the first time, a pentamidine analog capable of binding the “open” form of the “FF-gate” and provides a means to block all three “hot spots” on CaS100B, which will impact next generation CaS100B•p53 inhibitor design. PMID:26727270

  10. Passive transport pathways for Ca(2+) and Co(2+) in human red blood cells. (57)Co(2+) as a tracer for Ca(2+) influx.

    PubMed

    Simonsen, Lars Ole; Harbak, Henrik; Bennekou, Poul

    2011-12-15

    The passive transport of calcium and cobalt and their interference were studied in human red cells using (45)Ca and (57)Co as tracers. In ATP-depleted cells, with the ATP concentration reduced to about 1μM, the progress curve for (45)Ca uptake at 1mM rapidly levels off with time, consistent with a residual Ca-pump activity building up at increasing [Ca(T)](c) to reach at [Ca(T)](c) about 5μmol(lcells)(-1) a maximal pump rate that nearly countermands the passive Ca influx, resulting in a linear net uptake at a low level. In ATP-depleted cells treated with vanadate, supposed to cause Ca-pump arrest, a residual pump activity is still present at high [Ca(T)](c). Moreover, vanadate markedly increases the passive Ca(2+) influx. The residual Ca-pump activity in ATP-depleted cells is fuelled by breakdown of the large 2,3-DPG pool, rate-limited by the sustainable ATP-turnover at about 40-50μmol(lcells)(-1)h(-1). The apparent Ca(2+) affinity of the Ca-pump appears to be markedly reduced compared to fed cells. The 2,3-DPG breakdown can be prevented by inhibition of the 2,3-DPG phosphatase by tetrathionate, and under these conditions the (45)Ca uptake is markedly increased and linear with time, with the unidirectional Ca influx at 1mM Ca(2+) estimated at 50-60μmol(lcells)(-1)h(-1). The Ca influx increases with the extracellular Ca(2+) concentration with a saturating component, with K(½(Ca)) about 0.3mM, plus a non-saturating component. From (45)Ca-loaded, ATP-depleted cells the residual Ca-pump can also be detected as a vanadate- and tetrathionate-sensitive efflux. The (45)Ca efflux is markedly accelerated by external Ca(2+), both in control cells and in the presence of vanadate or tetrathionate, suggesting efflux by carrier-mediated Ca/Ca exchange. The (57)Co uptake is similar in fed cells and in ATP-depleted cells (exposed to iodoacetamide), consistent with the notion that Co(2+) is not transported by the Ca-pump. The transporter is thus neither SH-group nor ATP or

  11. A comparative study on Ca content and distribution in two Gesneriaceae species reveals distinctive mechanisms to cope with high rhizospheric soluble calcium

    PubMed Central

    Li, Wenlong; Xu, Falun; Chen, Shixuan; Zhang, Zhennan; Zhao, Yan; Jin, Yukuan; Li, Meijing; Zhu, Yan; Liu, Yongxiu; Yang, Yi; Deng, Xin

    2014-01-01

    Excessive Ca is toxic to plants thus significantly affects plant growth and species distribution in Ca-rich karst areas. To understand how plants survive high Ca soil, laboratory experiments were established to compare the physiological responses and internal Ca distribution in organ, tissue, cell, and intracellular levels under different Ca levels for Lysionotus pauciflorus and Boea hygrometrica, two karst habitant Gesneriaceae species in Southwest China. In the controlled condition, L. pauciflorus could survive as high as 200 mM rhizospheric soluble Ca, attributed to a series of physiological responses and preferential storage that limited Ca accumulation in chloroplasts of palisade cells. In contrast, B. hygrometrica could survive only 20 mM rhizospheric soluble Ca, but accumulated a high level of internal Ca in both palisade and spongy cells without disturbance on photosynthetic activity. By phenotype screening of transgenic plants expressing high Ca-inducible genes from B. hygrometrica, the expression of BhDNAJC2 in A. thaliana was found to enhance plant growth and photosynthesis under high soluble Ca stress. BhDNAJC2 encodes a recently reported heat shock protein (HSP) 40 family DnaJ-domain protein. The Ca-resistant phenotype of BhDNAJC2 highlights the important role of chaperone-mediated protein quality control in Ca tolerance in B. hygrometrica. Taken together, our results revealed that distinctive mechanisms were employed in the two Gesneriaceae karst habitants to cope with a high Ca environment. PMID:25477893

  12. NSAIDs inhibit neovascularization of choroid through HO-1-dependent pathway.

    PubMed

    Yoshinaga, Narimasa; Arimura, Noboru; Otsuka, Hiroki; Kawahara, Ko-Ichi; Hashiguchi, Teruto; Maruyama, Ikuro; Sakamoto, Taiji

    2011-09-01

    Intraocular neovascularization is the leading cause of severe visual loss and anti-vascular endothelial growth factor (VEGF) therapy is currently performed for choroidal neovascularization (CNV). Despite its potent anti-angiogenic effect, there are concerns about its long-term safety. Non-steroidal anti-inflammatory drugs (NSAIDs) are common therapeutic agents used for treating inflammatory diseases, and their anti-stress effects are attracting attention now. We studied the effects of topical NSAIDs on CNV, focusing on anti-stress proteins. Cultured retinal pigment epithelium (RPE) cells were treated with NSAIDs: bromfenac, indomethacin, or vehicle control. Transcription factor NF-E2-related factor 2 (Nrf2) and its downstream anti-oxidant protein heme oxygenase (HO)-1 were assessed using western blot and immunohistochemistry. As a result, NSAIDs induced translocation of Nrf2 into the nucleus and the robust expression of HO-1 in a dose- and time-dependent manner. Flow cytometric analysis revealed that bromfenac inhibited H(2)O(2)-induced apoptosis in cultured RPE cells. Next, we studied the effects of topical bromfenac on laser-induced CNV model in rat. The expressions of Nrf2 and HO-1, infiltrations of ED-1-positive macrophages at CNV lesions and size were analyzed. VEGF in the ocular fluid of these rats was also measured using enzyme-linked immunosorbent assay. Rats administered an inhibitor of HO-1 stannic mesoporphyrin (SnMP) were also studied. The results showed that topical bromfenac led to translocation of Nrf2 and induction of HO-1 in CNV lesions and that the number of infiltrating macrophages at the CNV lesion decreased. The sizes of CNV lesions were significantly smaller in bromfenac-treated rats than control CNV, and the effects were diminished by SnMP. VEGF increased in the ocular fluid after laser treatment and was inhibited by bromfenac and SnMP canceling these effects. NSAIDs inhibit CNV through the novel anti-stress protein HO-1-dependent pathway

  13. Role of Ca2+ channel in cardiac excitation-contraction coupling in the rat: evidence from Ca2+ transients and contraction.

    PubMed Central

    Cleemann, L; Morad, M

    1991-01-01

    1. Optical methods were used to measure simultaneously unloaded cell shortening and intracellular Ca2+ transients in whole-cell voltage clamped rat ventricular myocytes. Red light (greater than 670 nm) was used to measure cell shortening with a linear photodiode array. The dyes Fura-2 (Kd = 140 nM) and Mag-Fura-2 (Kd = 44 microM) were used as Ca2+ indicators with fluorescence excitation at 340 and 410 nm and emission at 510 nm. 2. Repeated measurements at 6 s intervals as 0.4 mM-Fura-2 diffused into the cell from the tip of the voltage clamp pipette showed no decrease in the rate of rise and peak value of the intracellular Ca2+ transient and only a small suppression of cell shortening, suggesting that the molecular mechanisms regulating the Ca2+ release were not significantly altered by the buffering capacity of the Fura-2. 3. Experiments in which the sarcoplasmic reticulum (SR) was depleted of Ca2+ either by exposure to caffeine or by repeated brief (20 ms) voltage clamp depolarizations confirm that the SR is the major source of activator Ca2+. 4. Mag-Fura-2 (1 or 5 mM) was used to register the initial rapid development of the [Ca2+]i transient but the later time course of the Ca2+ transients measured with this dye was obscured by motion artifacts resulting from cell shortening. 5. Both Fura-2 and Mag-Fura-2 showed that depolarization to 0 mV from a holding potential of -80 mV resulted in a [Ca2+]i transient which developed with a delay of 3-9 ms and approached its peak value in an additional 8-19 ms. Both Ca2+ indicators also showed that the Ca2+ transient approached its peak value more slowly as the clamped membrane potential was made increasingly more positive. 6. The voltage dependencies of the Ca2+ signal (Fura-2) and cell shortening were both bell-shaped and were qualitatively similar to the voltage dependence of Ca2+ current simultaneously measured. This was observed with holding potentials of both -40 and -80 mV. 7. Comparison of the temporal relation of

  14. Feasibility of converting hi-speed processor for processing Kodak film types 7381/7271 (16mm) and 5381/5271 (35mm) using Kodak ECP chemistry

    NASA Technical Reports Server (NTRS)

    Weinstein, M. S.

    1974-01-01

    Testing conducted to determine the feasibility of converting the 16/35/70 hi-speed processor to process Kodak film types 7381/7271 (16mm) and 5381/5271 (35mm) color negative films using Kodak ECP chemistry is described.

  15. Feature Films on 8mm and 16 mm. A Directory of Feature Films Available for Rental, Sale, and Lease in the United States.

    ERIC Educational Resources Information Center

    Limbacher, James L., Comp.

    Compiled from distributors' catalogs and supplementary lists, this third edition of the directory lists more than 10,000 feature films on 8mm and 16mm which are available for rental, sale, or lease. For this directory, a feature film is defined as one which runs more than 45 minutes or is longer than one reel. The films are listed in alphabetical…

  16. Over-expression of HO-1 on mesenchymal stem cells promotes angiogenesis and improves myocardial function in infarcted myocardium

    PubMed Central

    2010-01-01

    Heme oxygenase-1 (HO-1) is a stress-inducible enzyme with diverse cytoprotective effects, and reported to have an important role in angiogenesis recently. Here we investigated whether HO-1 transduced by mesenchymal stem cells (MSCs) can induce angiogenic effects in infarcted myocardium. HO-1 was transfected into cultured MSCs using an adenoviral vector. 1 × 106 Ad-HO-1-transfected MSCs (HO-1-MSCs) or Ad-Null-transfected MSCs (Null-MSCs) or PBS was respectively injected into rat hearts intramyocardially at 1 h post-myocardial infarction. The results showed that HO-1-MSCs were able to induce stable expression of HO-1 in vitro and in vivo. The capillary density and expression of angiogenic growth factors, VEGF and FGF2 were significantly enhanced in HO-1-MSCs-treated hearts compared with Null-MSCs-treated and PBS-treated hearts. However, the angiogenic effects of HO-1 were abolished by treating the animals with HO inhibitor, zinc protoporphyrin. The myocardial apoptosis was marked reduced with significantly reduced fibrotic area in HO-1-MSCs-treated hearts; Furthermore, the cardiac function and remodeling were also significantly improved in HO-1-MSCs-treated hearts. Our current findings support the premise that HO-1 transduced by MSCs can induce angiogenic effects and improve heart function after acute myocardial infarction. PMID:20925964

  17. CA V is present in rat kidney mitochondria

    SciTech Connect

    Dodgson, S.J.; Contino, L.C.

    1987-05-01

    Guinea pig liver mitochondria contain the unique carbonic anhydrase isozyme, CA V. Prior to sacrifice, 15 rats and 15 guinea pigs were either fed normal lab chow (group 1), starved 48 hours (group 2) or fed normal lab chow and given to drink only water with added HCl, pH 2.5 (group 3). Mitochondria were prepared from excised livers and kidneys. CA V activity of disrupted mitochondria was measured by /sup 18/O-mass spectrometric technique at pH 7.4, 37/sup 0/C, 25 mM NaHCO/sub 3/. Mass spectrometric CA assays with intact kidney mitochondria localize CA V activity to the matrix, as was found for liver mitochondria. It has been shown in hepatocytes prepared from starved guinea pigs and rats that inhibition of CA V results in decreased rate of gluconeogenesis from pyruvate. These present results are in line with the published observation that rat kidneys are much more gluconeogenic than guinea pig, and that this is increased by starvation and acidosis.

  18. Alteration by phosphatidyl serine of tension responses and 45Ca distribution in aortic smooth muscle.

    PubMed

    Goodman, F R; Weiss, G B; Goth, A

    1976-07-01

    The effects of phosphatidyl serine (PS) on 45Ca distribution, 45Ca movements and contractions were examined in rabbit aortic smooth muscle. Contractile responses to submaximal concentrations of norepinephrine and histamine were potentiated by prior exposure to PS, but equivalent responses to potassium were unaffected. Addition of PS to the incubation solution decreased 45Ca uptake; exposure of aortic strips to PS during washout of either 45Ca or promethium (147Pm) resulted in maintained increases in efflux. These PS-induced alterations in net loss of 45Ca or 147Pm can be attributed to a decreased membrane reuptake and/or rebinding. However, the presence of PS during the washout significantly reduced the increases in 45Ca efflux rate elicited with either 0.05 mM concentrations of Ca++ or ethylenediamine tetraacetic acid. Thus, in rabbit aortic smooth muscle, exogenous PS can alter the availability and/or exchangeability of a membrane-bound Ca++ fraction. By specifically increasing the affinity for Ca++ at relevant membrane sites or stores. PS may enhance the ability of vascular smooth muscle to respond to stimulatory agents that mobilize Ca++ from these sites and, in this manner, potentiate contractile responses. PMID:933004

  19. Measurements of HO2 chemical kinetics with a new detection method

    NASA Technical Reports Server (NTRS)

    Lee, L. C.; Suto, M.

    1986-01-01

    Research for the period from December 1, 1985 to May 31, 1986 is discussed, i.e., the reaction rate constant of HO2+O3 has been measured with a discharge-flow-tube apparatus. The HO2 radical was detected by the OH(A-X) photofragment emission produced from photodissociative excitation of HO2 at 147 nm. In the meantime, the optical emissions produced by the vacuum ultraviolet excitation of chemical species in the flow tube were investigated and used to examine the possibility for their interference with the HO2 detection. The research results are summarized below.

  20. [hHO-1 structure prediction and its mutant construct, expression, purification and activity analysis].

    PubMed

    Xia, Zhen Wei; Cui, Wen Jun; Zhou, Wen Pu; Zhang, Xue Hong; Shen, Qing Xiang; Li, Yun Zhu; Yu, Shan Chang

    2004-10-01

    Human Heme Oxygenase-1 (hHO-1) is the rate-limiting enzyme in the catabolism reaction of heme, which directly regulates the concentration of bilirubin in human body. The mutant structure was simulated by Swiss-pdbviewer procedure, which showed that the structure of active pocket was changed distinctly after Ala25 substituted for His25 in active domain, but the mutated enzyme still binded with heme. On the basis of the results, the expression vectors, pBHO-1 and pBHO-1(M), were constructed, induced by IPTG and expressed in E. coli DH5alpha strain. The expression products were purified with 30%-60% saturation (NH4)2SO4 and Q-Sepharose Fast Flow column chromatography. The concentration of hHO-1 in 30%-60% saturation (NH4)2SO4 components and in fractions through twice column chromatography was 3.6-fold and 30-fold higher than that in initial product, respectively. The activity of wild hHO-1 (whHO-1) and mutant hHO-1 (deltahHO-1) showed that the activity of deltahHO-1 was reduced 91.21% compared with that of whHO-1. The study shows that His25 is of importance for the mechanism of hHO-1, and provides the possibility for effectively regulating the activity to exert biological function. PMID:15636365

  1. Dietary calcium attenuates platelet aggregation and intracellular Ca2+ mobilization in spontaneously hypertensive rats

    NASA Technical Reports Server (NTRS)

    Otsuka, K.; Watanabe, M.; Yue, Q.; McCarron, D. A.; Hatton, D.

    1997-01-01

    Spontaneously hypertensive rats (SHR) are known to be blood pressure sensitive to dietary calcium. The effects of dietary calcium on platelet aggregation and intracellular Ca2+ mobilization were assessed by turbidimetric methods and fura-2 methods, respectively, in washed platelets of SHR. Ca2+ ATPase activity was examined in aortic membrane fractions. Six weeks of dietary calcium supplementation attenuated the increase of systolic blood pressure (SBP 199 +/- 16 v 170 +/- 9 mm Hg, P < .001) and thrombin-induced platelet aggregation (84.5 +/- 3.7 v 73.7 +/- 7.4%, P < .004) at 9 weeks of age. The ionomycin-induced intracellular calcium ([Ca2+]i) peak in the absence of external Ca2+, which reflects [Ca2+]i storage size, and thrombin-evoked [Ca2+]i release from [Ca2+]i storage were decreased by 2.0% Ca diet (472 +/- 55 v 370 +/- 23 nmol/L, P < .001, 339 +/- 29 v 278 +/- 33 nmol/L, P < .002). In addition, SBP was positively correlated with platelet aggregation (r = 0.703, P = .0088), thrombin-evoked [Ca2+]i (r = 0.739, P = .0044), and ionomycin-induced [Ca2+]i (r = 0.591, P = .0415), respectively. However, there was no significant effect of dietary calcium on Ca2+-ATPase activity in aortic membranes. These results suggest that dietary calcium supplementation had a beneficial effect on platelets of SHR by attenuating [Ca2+]i mobilization from [Ca2+]i storage. The hypotensive effect of dietary calcium might be associated with attenuated [Ca2+]i mobilization in SHR.

  2. Synchronization of Ca(2+)-signals within insulin-secreting pseudoislets: effects of gap-junctional uncouplers.

    PubMed

    Squires, P E; Hauge-Evans, A C; Persaud, S J; Jones, P M

    2000-05-01

    The secretory response of the intact islet is greater than the response of individual beta-cells in isolation, and functional coupling between cells is critical in insulin release. The changes in intracellular Ca(2+)([Ca(2+)](i)) which initiate insulin secretory responses are synchronized between groups of cells within the islet, and gap-junctions are thought to play a central role in coordinating signalling events. We have used the MIN6 insulin-secreting cell line, to examine whether uncoupling gap-junctions alters the synchronicity of nutrient- and non-nutrient-evoked Ca(2+)oscillations, or affects insulin secretion. MIN6 cells express mRNA species that can be amplified using PCR primers for connexin 36. A commonly used gap-junctional inhibitor, heptanol, inhibited glucose- and tolbutamide-induced Ca(2+)-oscillations to basal levels in MIN6 cell clusters at concentrations of 0.5 mM and greater, and it had similar effects in pseudoislets when used at 2.5 mM. Lower heptanol concentrations altered the frequency of Ca(2+)transients without affecting their synchronicity, in both monolayers and pseudoislets. Heptanol also had effects on insulin secretion from MIN6 pseudoislets such that 1 mM enhanced secretion while 2.5 mM was inhibitory. These data suggest that heptanol has multiple effects in pancreatic beta-cells, none of which appears to be related to uncoupling of synchronicity of Ca(2+)signalling between cells. A second gap-junction uncoupler, 18 alpha-glycyrrhetinic acid, also failed to uncouple synchronized Ca(2+)-oscillations, and it had no effect on insulin secretion. These data provide evidence that Ca(2+)signalling events occur simultaneously across the bulk mass of the pseudoislet, and suggest that gap-junctions are not required to coordinate the synchronicity of these events, nor is communication via gap junctions essential for integrated insulin secretory responses. PMID:10859595

  3. Effects of Mg2+ on Ca2+ release from sarcoplasmic reticulum of skeletal muscle fibres from yabby (crustacean) and rat.

    PubMed

    Launikonis, B S; Stephenson, D G

    2000-07-15

    1. The role of myoplasmic [Mg2+] on Ca2+ release from the sarcoplasmic reticulum (SR) was examined in the two major types of crustacean muscle fibres, the tonic, long sarcomere fibres and the phasic, short sarcomere fibres of the fresh water decapod crustacean Cherax destructor (yabby) and in the fast-twitch rat muscle fibres using the mechanically skinned muscle fibre preparation. 2. A robust Ca2+-induced Ca2+-release (CICR) mechanism was present in both long and short sarcomere fibres and 1 mM Mg2+ exerted a strong inhibitory action on the SR Ca2+ release in both fibre types. 3. The SR displayed different properties with respect to Ca2+ loading in the long and the short sarcomere fibres and marked functional differences were identified with respect to Mg2+ inhibition between the two crustacean fibre types. Thus, in long sarcomere fibres, the submaximally loaded SR was able to release Ca2+ when [Mg2+] was lowered from 1 to 0.01 mM in the presence of 8 mM ATPtotal and in the virtual absence of Ca2+ (< 5 nM) even when the CICR was suppressed. In contrast, negligible Ca2+ was released from the submaximally loaded SR of short sarcomere yabby fibres when [Mg2+] was lowered from 1 to 0.01 mM under the same conditions as for the long sarcomere fibres. Nevertheless, the rate of SR Ca2+ release in short sarcomere fibres increased markedly when [Mg2+] was lowered in the presence of [Ca2+] approaching the normal resting levels (50-100 nM). 4. Rat fibres were able to release SR Ca2+ at a faster rate than the long sarcomere yabby fibres when [Mg2+] was lowered from 1 to 0. 01 mM in the virtual absence of Ca2+ but, unlike with yabby fibres, the net rate of Ca2+ release was actually increased for conditions that were considerably less favourable to CICR. 5. In summary, it is concluded that crustacean skeletal muscles have more that one functional type of Ca2+-release channels, that these channels display properties that are intermediate between those of mammalian skeletal and

  4. Mechanisms of Ca uptake in high K/low Na solutions

    SciTech Connect

    Lodge, N.J.; Gelband, H.

    1986-03-05

    Ca uptake into neonatal rat atrium was measured with /sup 45/Ca. Extracellular /sup 45/Ca was displaced by washing tissues (45 min) in ice-cold Tyrode's containing 6.8 mM Ca/5 mM EGTA. Unless otherwise stated, solutions were pH balanced with HCO/sub 3//PO/sub 4//CO/sub 2/. Solutions in which 129 mM K or choline were substituted for 129 mM Na significantly stimulated Ca uptake (p < 0.001 for both). Inhibition of the Na/K pump (0 mM K solution), to increase intracellular Na, increased subsequent Ca uptakes measured in control, choline/low Na and high K/low Na solutions. The choline/low Na-stimulated uptake was increased by 104% while the high K/low Na stimulated uptake was increased only 11%. Cadmium (0.01-10 mM) blockade of the choline/low Na and high K/low Na uptakes was tested. Hepes buffered (HCO/sub 3//PO/sub 4//CO/sub 2/-free) solutions were used to avoid precipitation of Cd salts. The high K/low Na (Hepes) uptake was significantly (p < 0.001) greater than control and was 50% inhibited by 0.3 mM Cd. Choline/low Na in Hepes buffer increased Ca uptake only 5.1 +/- 4.3 ..mu..mol/kg (n=22) above control. In separate experiments, the choline/low Na (Hepes)-stimulated uptake (12.8 +/- 4.3 ..mu..mol/kg, n=8) was increased to 29.3 +/- 4.7 ..mu..mol/kg (n=8) by the addition of 1.8 mM PO/sub 4/. This intervention reduced the high K/low Na (Hepes)-stimulated uptake (47.1 +/- 6.4 ..mu..mol/kg, n=8) to 33.8 +/- 4.5 ..mu..mol/kg (n=8). They hypothesize that the uptake of Ca, induced by solutions of elevated K and lowered Na, is mediated by a minimum of two mechanisms; one stimulated by PO/sub 4/ and sensitive to transmembrane ion gradients, the other reduced by PO/sub 4/ and relatively insensitive to ion gradients.

  5. CaPTC Biennial Meetings

    Cancer.gov

    CaPTC hosts the 'Biennial Science of Global Prostate Cancer Disparities in Black Men' conference to address the growing global public health problem of prostate cancer among Black men in industrialized and developing countries.

  6. Effects of mibefradil and nifedipine on arteriolar myogenic responsiveness and intracellular Ca2+

    PubMed Central

    Potocnik, Simon J; Murphy, Timothy V; Kotecha, Neela; Hill, Michael A

    2000-01-01

    Ca2+ entry mechanisms underlying spontaneous arteriolar tone and acute myogenic reactivity remain uncertain. These studies aimed to compare the effects of nifedipine and the putative T-channel blocker, mibefradil, on arteriolar myogenic responsiveness and intracellular Ca2+ (Ca2+i).First order cremaster muscle arterioles (1A) were isolated from rats, cannulated, pressurized to 70 mmHg in the absence of intraluminal flow, and mechanical responses studied by video microscopy. The Ca2+i was measured using fluorescence imaging of Fura 2 loaded arterioles.Both nifedipine and mibefradil showed dose-dependent inhibition of spontaneous myogenic tone (at 70 mmHg; pEC50 7.04±0.17 vs 6.65±0.20 respectively, n=6 for both, n.s.) and KCl-induced vasoconstriction (at 70 mmHg; pEC50 6.93±0.38 vs 6.45±0.27 respectively, n=6 for both, n.s.).In arterioles maintained at 50 mmHg, nifedipine (10−7 and 10−5 M) caused a concentration dependent reduction in Ca2+i, however, mibefradil (10−7 and 10−5 M) had no effect. Furthermore nifedipine significantly attenuated the increase in Ca2+i associated with an acute pressure step (50–120 mmHg) whereas mibefradil was considerably less effective.Mibefradil (10−7 M) significantly attenuated contractile responses to 60 mM KCl without altering the KCl-induced increase in Ca2+i, in contrast to nifedipine (10−7 M) which reduced both Ca2+i and contraction.Membrane potential of arterioles with spontaneous myogenic tone (70 mmHg) was −41.5±1.0 mV. Nifedipine (10−7 or 10−5 M) had no effect on membrane potential, however mibefradil (10−5 M) caused significant depolarization.In summary, both mibefradil and nifedipine inhibit arteriolar spontaneous tone and acute myogenic reactivity. While there may be overlap in the mechanisms by which these agents inhibit tone, differences in effects on membrane potential and intracellular Ca2+ levels suggest mibefradil exhibits actions other than blockade of Ca2+ entry

  7. Specific actions of gallium on contractile responses and /sup 45/Ca movements in rabbit aortic smooth muscle

    SciTech Connect

    Shetty, S.S.; Weiss, G.B.

    1986-03-01

    Gallium ion (Ga/sup + +/) dose-dependently (0.1-0.5 mM) inhibited contractions induced by norepinephrine (NE, 10/sup -6/ M) in rabbit aortic (and media-intimal) strips, but did not affect contractions elicited with high K/sup +/ (160 mM K/sup +/-substituted solution). The initial phasic portion of the NE-induced response was only slightly (< 10%) reduced, but the tonic portion of the response was completely inhibited by higher concentrations (0.3-0.5 mM) of Ga/sup + +/. In resting muscles, the equilibrated (90 min) /sup 45/Ca uptake was not altered by Ga/sup + +/. The effects of Ga/sup + +/ on /sup 45/Ca retained after a subsequent 60-min washout at 0.5/sup 0/C in an isosmotic (80.8 mM) La/sup + + +/ solution were also examined. Under conditions favoring low affinity Ca/sup + +/ uptake, /sup 45/Ca retention in control and K/sup +/-treated muscles was not changed by Ga/sup + +/, but the additional incremental /sup 45/Ca uptake associated with NE (in the presence of K/sup +/) was blocked. The efflux of /sup 45/Ca was transiently increased by Ga/sup + +/ only under conditions favoring detection of high affinity /sup 45/Ca release. High affinity La/sup + + +/-resistant /sup 45/Ca released by NE was not altered by Ga/sup + +/. Thus, Ga/sup + +/ appears to have a selective inhibitory action on NE-associated /sup 45/Ca uptake without affecting either resting and K/sup +/-induced /sup 45/Ca uptake or the /sup 45/Ca fraction released by Ne.

  8. Conditions sufficient for nonsynaptic epileptogenesis in the CA1 region of hippocampal slices.

    PubMed

    Bikson, Marom; Baraban, Scott C; Durand, Dominique M

    2002-01-01

    Nonsynaptic mechanisms exert a powerful influence on seizure threshold. It is well-established that nonsynaptic epileptiform activity can be induced in hippocampal slices by reducing extracellular Ca(2+) concentration. We show here that nonsynaptic epileptiform activity can be readily induced in vitro in normal (2 mM) Ca(2+) levels. Those conditions sufficient for nonsynaptic epileptogenesis in the CA1 region were determined by pharmacologically mimicking the effects of Ca(2+) reduction in normal Ca(2+) levels. Increasing neuronal excitability, by removing extracellular Mg(2+) and increasing extracellular K(+) (6-15 mM), induced epileptiform activity that was suppressed by postsynaptic receptor antagonists [D-(-)-2-amino-5-phosphonopentanoic acid, picrotoxin, and 6,7-dinitroquinoxaline-2,3-dione] and was therefore synaptic in nature. Similarly, epileptiform activity induced when neuronal excitability was increased in the presence of K(Ca) antagonists (verruculogen, charybdotoxin, norepinephrine, tetraethylammonium salt, and Ba(2+)) was found to be synaptic in nature. Decreases in osmolarity also failed to induce nonsynaptic epileptiform activity in the CA1 region. However, increasing neuronal excitability (by removing extracellular Mg(2+) and increasing extracellular K(+)) in the presence of Cd(2+), a nonselective Ca(2+) channel antagonist, or veratridine, a persistent sodium conductance enhancer, induced spontaneous nonsynaptic epileptiform activity in vitro. Both novel models were characterized using intracellular and ion-selective electrodes. The results of this study suggest that reducing extracellular Ca(2+) facilitates bursting by increasing neuronal excitability and inhibiting Ca(2+) influx, which might, in turn, enhance a persistent sodium conductance. Furthermore, these data show that nonsynaptic mechanisms can contribute to epileptiform activity in normal Ca(2+) levels. PMID:11784730

  9. Sub-mm Jet Properties of the X-Ray Binary Swift J1745-26

    NASA Astrophysics Data System (ADS)

    Tetarenko, A. J.; Sivakoff, G. R.; Miller-Jones, J. C. A.; Curran, P. A.; Russell, T. D.; Coulson, I. M.; Heinz, S.; Maitra, D.; Markoff, S. B.; Migliari, S.; Petitpas, G. R.; Rupen, M. P.; Rushton, A. P.; Russell, D. M.; Sarazin, C. L.

    2015-05-01

    We present the results of our observations of the early stages of the 2012-2013 outburst of the transient black hole X-ray binary (BHXRB), Swift J1745-26, with the Very Large Array, Submillimeter Array, and James Clerk Maxwell telescope (SCUBA-2). Our data mark the first multiple-band mm and sub-mm observations of a BHXRB. During our observations the system was in the hard accretion state producing a steady, compact jet. The unique combination of radio and mm/sub-mm data allows us to directly measure the spectral indices in and between the radio and mm/sub-mm regimes, including the first mm/sub-mm spectral index measured for a BHXRB. Spectral fitting revealed that both the mm (230 GHz) and sub-mm (350 GHz) measurements are consistent with extrapolations of an inverted power law from contemporaneous radio data (1-30 GHz). This indicates that, as standard jet models predict, a power law extending up to mm/sub-mm frequencies can adequately describe the spectrum, and suggests that the mechanism driving spectral inversion could be responsible for the high mm/sub-mm fluxes (compared to radio fluxes) observed in outbursting BHXRBs. While this power law is also consistent with contemporaneous optical data, the optical data could arise from either jet emission with a jet spectral break frequency of {{ν }break}≳ 1× {{10}14} Hz or the combination of jet emission with a lower jet spectral break frequency of {{ν }break}≳ 2× {{10}11} Hz and accretion disk emission. Our analysis solidifies the importance of the mm/sub-mm regime in bridging the crucial gap between radio and IR frequencies in the jet spectrum, and justifies the need to explore this regime further.

  10. Cathodoluminescence of GaN implanted with Sm and Ho

    SciTech Connect

    Lozykowski, H.J.; Jadwisienczak, W.M.; Brown, I.

    1999-04-01

    We report the first observation of visible cathodoluminescence of the rare earth (RE) elements Sm, Ho implanted in GaN. The implanted samples were given isochronal thermal annealing treatments at a temperature of 1100 degrees C in N2, at atmospheric pressure to recover implantation damages and activate the RE ions. The sharp characteristic emission lines corresponding to Sm{sup 3+} and Ho{sup 3+} intra-4f{sup n}-shell transitions are resolved in the spectral range from 400 to 1000 nm, and observed over the temperature range of 11-411 K. The cathodoluminescence emission is only weakly temperature dependent. The results indicate that RE doped GaN epilayers are suitable as a material for visible optoelectronic devices.

  11. Itinerant and Localized Magnetization Dynamics in Antiferromagnetic Ho.

    PubMed

    Rettig, L; Dornes, C; Thielemann-Kühn, N; Pontius, N; Zabel, H; Schlagel, D L; Lograsso, T A; Chollet, M; Robert, A; Sikorski, M; Song, S; Glownia, J M; Schüßler-Langeheine, C; Johnson, S L; Staub, U

    2016-06-24

    Using femtosecond time-resolved resonant magnetic x-ray diffraction at the Ho L_{3} absorption edge, we investigate the demagnetization dynamics in antiferromagnetically ordered metallic Ho after femtosecond optical excitation. Tuning the x-ray energy to the electric dipole (E1, 2p→5d) or quadrupole (E2, 2p→4f) transition allows us to selectively and independently study the spin dynamics of the itinerant 5d and localized 4f electronic subsystems via the suppression of the magnetic (2 1 3-τ) satellite peak. We find demagnetization time scales very similar to ferromagnetic 4f systems, suggesting that the loss of magnetic order occurs via a similar spin-flip process in both cases. The simultaneous demagnetization of both subsystems demonstrates strong intra-atomic 4f-5d exchange coupling. In addition, an ultrafast lattice contraction due to the release of magneto-striction leads to a transient shift of the magnetic satellite peak. PMID:27391747

  12. Itinerant and Localized Magnetization Dynamics in Antiferromagnetic Ho

    NASA Astrophysics Data System (ADS)

    Rettig, L.; Dornes, C.; Thielemann-Kühn, N.; Pontius, N.; Zabel, H.; Schlagel, D. L.; Lograsso, T. A.; Chollet, M.; Robert, A.; Sikorski, M.; Song, S.; Glownia, J. M.; Schüßler-Langeheine, C.; Johnson, S. L.; Staub, U.

    2016-06-01

    Using femtosecond time-resolved resonant magnetic x-ray diffraction at the Ho L3 absorption edge, we investigate the demagnetization dynamics in antiferromagnetically ordered metallic Ho after femtosecond optical excitation. Tuning the x-ray energy to the electric dipole (E 1 , 2 p →5 d ) or quadrupole (E 2 , 2 p →4 f ) transition allows us to selectively and independently study the spin dynamics of the itinerant 5 d and localized 4 f electronic subsystems via the suppression of the magnetic (2 1 3 -τ ) satellite peak. We find demagnetization time scales very similar to ferromagnetic 4 f systems, suggesting that the loss of magnetic order occurs via a similar spin-flip process in both cases. The simultaneous demagnetization of both subsystems demonstrates strong intra-atomic 4 f -5 d exchange coupling. In addition, an ultrafast lattice contraction due to the release of magneto-striction leads to a transient shift of the magnetic satellite peak.

  13. Holographic superconductors with Hořava-Lifshitz black holes

    NASA Astrophysics Data System (ADS)

    Cai, Rong-Gen; Zhang, Hai-Qing

    2010-03-01

    We discuss the phase transition of planar black holes in Hořava-Lifshitz gravity by introducing a Maxwell field and a complex scalar field. We calculate the condensate of the charged operators in the dual conformal field theories when the mass square of the complex scalar field is m2=-2/L2 and m2=0, respectively. We compute the electrical conductivity of the Hořava-Lifshitz superconductor in the probe approximation. In particular, it is found that there exists a spike in the conductivity for the case of the operator with scaling dimension one. These results are quite similar to those in the case of Schwarzschild-AdS black holes, which demonstrates that the holographic superconductivity is a robust phenomenon associated with asymptotic AdS black holes.

  14. Thermochemical stability of the HO 2-HOCl complex

    NASA Astrophysics Data System (ADS)

    Jalbout, A. F.; Li, X. H.; Solimannejad, M.

    2006-03-01

    The Van der Waals complex between hydroperoxy radical (HO 2) and hypochlorous acid (HOCl) has been studied using the B3LYP density functional theory method, the second-order Moller-Plessett level of theory, as well as the coupled-cluster method (CCSD(T)) with basis sets as large as 6-311++G(3df, 3pd). Our calculations show stabilization energies for HO 2-HOCl of 4.83, 5.03, 4.64, and 5.28 kcal/mol at the B3LYP/6-311++G(3df, 3pd), MP2/6-311++G(3df, 3pd), CCSD(T)/6-311++G(3df, 3pd) and G2 levels of theory, respectively.

  15. Rapid Ca2+ flux through the transverse tubular membrane, activated by individual action potentials in mammalian skeletal muscle

    PubMed Central

    Launikonis, Bradley S; Stephenson, D George; Friedrich, Oliver

    2009-01-01

    Periods of low frequency stimulation are known to increase the net Ca2+ uptake in skeletal muscle but the mechanism responsible for this Ca2+ entry is not known. In this study a novel high-resolution fluorescence microscopy approach allowed the detection of an action potential-induced Ca2+ flux across the tubular (t-) system of rat extensor digitorum longus muscle fibres that appears to be responsible for the net uptake of Ca2+ in working muscle. Action potentials were triggered in the t-system of mechanically skinned fibres from rat by brief field stimulation and t-system [Ca2+] ([Ca2+]t-sys) and cytoplasmic [Ca2+] ([Ca2+]cyto) were simultaneously resolved on a confocal microscope. When initial [Ca2+]t-sys was ≥ 0.2 mm a Ca2+ flux from t-system to the cytoplasm was observed following a single action potential. The action potential-induced Ca2+ flux and associated t-system Ca2+ permeability decayed exponentially and displayed inactivation characteristics such that further Ca2+ entry across the t-system could not be observed after 2–3 action potentials at 10 Hz stimulation rate. When [Ca2+]t-sys was closer to 0.1 mm, a transient rise in [Ca2+]t-sys was observed almost concurrently with the increase in [Ca2+]cyto following the action potential. The change in direction of Ca2+ flux was consistent with changes in the direction of the driving force for Ca2+. This is the first demonstration of a rapid t-system Ca2+ flux associated with a single action potential in mammalian skeletal muscle. The properties of this channel are inconsistent with a flux through the L-type Ca2+ channel suggesting that an as yet unidentified t-system protein is conducting this current. This action potential-activated Ca2+ flux provides an explanation for the previously described Ca2+ entry and accumulation observed with prolonged, intermittent muscle activity. PMID:19332499

  16. The reactions of HO2 with CO and NO and the reaction of O(1D) with H2O

    NASA Technical Reports Server (NTRS)

    Simonaitis, R.; Heicklen, J.

    1973-01-01

    HO2 radicals were generated by the photolysis of N2O at 2139 A in the presence of excess H2O or H2 and smaller amounts of CO and O2. The O(1D) atoms produced from the photolysis of N2O to give HO radicals or H2 to give HO + H. With H2O two HO radicals are produced for each O(1D) removed low pressures (i.e. approximately 20 torr H2O), but the HO yield drops as the pressure is raised. This drop is attributed to the insertion reaction: O(1D) + H2O + M yields H2O2 +M. The HO radicals generated can react with either CO or H2 to produce H atoms which then add to O2 to produce HO2. Two reactions are given for the reactions of the HO radicals, in the absence of NO.

  17. Effect of cation substitution on structural transition: synthesis, characterization and theoretical studies of NaCa4B3O9, NaCaBO3, NaSrBO3 and Li4CaB2O6.

    PubMed

    Yang, Yun; Su, Xin; Pan, Shilie; Yang, Zhihua

    2015-10-21

    Single crystals of NaCa4B3O9, NaCaBO3, NaSrBO3 and Li4CaB2O6 have been successfully synthesized through conventional high-temperature solid-state reactions. They are structurally characterized by single crystal X-ray diffraction and exhibit three-dimensional crystal structures consisting of isolated planar BO3 as fundamental building blocks. Interestingly, for the centrosymmetric crystal structure of NaCaBO3 (Na3Ca3B3O9), as 2/3 of the Na(+) ions are substituted by Ca(2+) ions, NaCa4B3O9 is obtained and crystallizes in the noncentrosymmetric space group Ama2 (crystal class mm2). A second harmonic generation (SHG) test of the title compound by the Kurtz-Perry method shows that NaCa4B3O9 can be phase matchable with an effective SHG coefficient approximately one-half that of KH2PO4 (KDP). Studies of their optical properties as well as band structure calculations based on density functional theory methods have been also performed. NaCa4B3O9 possesses a moderate birefringence of about 0.05 at 1064 nm. To explain the difference in optical nonlinearity we compared the electronic structures of NaCa4B3O9, KCa4B3O9 and KSr4B3O9 crystals, in particular at the bottom of the conduction band (CB) and the top of the valence band (VB), since they are known to play a primary role in SHG. These electronic structures are responsible for the optical-nonlinearity of NaCa4B3O9, KCa4B3O9 and KSr4B3O9 crystals. PMID:26387438

  18. Molecular dynamics simulations of ion solvation by flexible-boundary QM/MM: on-the-fly partial charge transfer between QM and MM subsystems.

    PubMed

    Pezeshki, Soroosh; Lin, Hai

    2014-09-15

    The flexible-boundary (FB) quantum mechanical/molecular mechanical (QM/MM) scheme accounts for partial charge transfer between the QM and MM subsystems. Previous calculations have demonstrated excellent performance of FB-QM/MM in geometry optimizations. This article reports an implementation to extend FB-QM/MM to molecular dynamics simulations. To prevent atoms from getting unreasonably close, which can lead to polarization catastrophe, empirical correcting functions are introduced to provide additive penalty energies for the involved atom pairs and to improve the descriptions of the repulsive exchange forces in FB-QM/MM calculations. Test calculations are carried out for chloride, lithium, sodium, and ammonium ions solvated in water. Comparisons with conventional QM/MM calculations suggest that the FB treatment provides reasonably good results for the charge distributions of the atoms in the QM subsystems and for the solvation shell structural properties, albeit smaller QM subsystems have been used in the FB-QM/MM dynamics simulations. PMID:25056247

  19. Identical gamma-vibrational bands in {sup 165}Ho

    SciTech Connect

    Radford, D.C.; Galindo-Uribarri, A.; Janzen, V.P.

    1996-12-31

    The structure of {sup 165}Ho at moderate spins has been investigated by means of Coulomb excitation. Two {gamma}-vibrational bands (K{sup {pi}} = 11/2{sup {minus}} and K{sup {pi}} = 3/2{sup {minus}}) are observed, with very nearly identical in-band {gamma}-ray energies. Gamma-ray branching ratios are analyzed to extract information on Coriolis mixing, and the role of the K quantum number in identical bands is discussed.

  20. Brain metabolism is significantly impaired at blood glucose below 6 mM and brain glucose below 1 mM in patients with severe traumatic brain injury

    PubMed Central

    2010-01-01

    Introduction The optimal blood glucose target following severe traumatic brain injury (TBI) must be defined. Cerebral microdialysis was used to investigate the influence of arterial blood and brain glucose on cerebral glucose, lactate, pyruvate, glutamate, and calculated indices of downstream metabolism. Methods In twenty TBI patients, microdialysis catheters inserted in the edematous frontal lobe were dialyzed at 1 μl/min, collecting samples at 60 minute intervals. Occult metabolic alterations were determined by calculating the lactate- pyruvate (L/P), lactate- glucose (L/Glc), and lactate- glutamate (L/Glu) ratios. Results Brain glucose was influenced by arterial blood glucose. Elevated L/P and L/Glc were significantly reduced at brain glucose above 1 mM, reaching lowest values at blood and brain glucose levels between 6-9 mM (P < 0.001). Lowest cerebral glutamate was measured at brain glucose 3-5 mM with a significant increase at brain glucose below 3 mM and above 6 mM. While L/Glu was significantly increased at low brain glucose levels, it was significantly decreased at brain glucose above 5 mM (P < 0.001). Insulin administration increased brain glutamate at low brain glucose, but prevented increase in L/Glu. Conclusions Arterial blood glucose levels appear to be optimal at 6-9 mM. While low brain glucose levels below 1 mM are detrimental, elevated brain glucose are to be targeted despite increased brain glutamate at brain glucose >5 mM. Pathogenity of elevated glutamate appears to be relativized by L/Glu and suggests to exclude insulin- induced brain injury. PMID:20141631