Sample records for delta gh 2o

  1. Simulation of temporal and spatial change of N2O emissions in the Yangtze River Delta

    LIU Jian-dong; ZHOU Xiu-ji; CHEN De-liang; OUYANG Zhi-yun; WANG Xiao-ke; Achberger Christine


    A biogeochemical model(DNDC) is combined with a plant ecological model to estimate N2O emission from rice paddy fields in the Yangtze River Delta region. The model is driven by local meteorological, soil, and physiological data and is validated for 1999 and 2000 at a site in the region, which showed that the simulated N2O emissions agree fairly well with the observed data. This adds some confidence in the estimated N2O emissions during 1950 and 2000 in the Hangzhou Region. A significant correlation between the N2O emissions and the population for the Hangzhou Region is found, which is due to a combination of increased application of fertilizers and cultivated area.Such a correlation can not be established for the whole Yangtze River Delta region when the data of both urban and rural areas are included. However, when the data from the heavily urbanized areas are excluded, a significant correlation between population and N2O emissions emerges. The results show clearly that both the temporal and the spatial N2O emissions have significant positive relationship with population under traditional farming practice. These results have implications for suitable mitigation options towards a sustainable agriculture and environment in this region.

  2. Synthesis of nanocrystalline Ce(0.8)Gd(0.2)O(2-delta) electrolyte materials for IT-SOFC.

    Park, K; Choi, J W; Hwang, H K; Saradha, T


    We successfully synthesized nano-sized Ce(0.8)Gd(0.2)O(2-delta) powders by combustion method, using gelatin as fuel. The calcined powders showed high-quality characteristics, i.e., nano-scale size (14-35 nm) and narrow size distribution. The structural, morphological, and electrical characteristics of the sintered Ce(0.8)Gd(0.2)O(2-delta) were studied systematically, depending on sintering temperature. The crystal structure of the Ce(0.8)Gd(0.2)O(2-delta) belonged to the cubic fluorite structure. The gelatin-assisted combustion synthesized Ce(0.8)Gd(0.2)O(2-delta) powders allowed to sinter well at low temperature for dense and ultra-fine Ce(0.8)Gd(0.2)O(2-delta) electrolyte with good electrical conductivity. The sintering temperature of the Ce(0.8)Gd(0.2)O2 powder was approximately 300 degrees C lower than that of conventional solid-state synthesized powder. The nanopowder produced was sintered into pellets with relative densities over 99.1% of the theoretical value even at 1400 degrees C. The Ce(0.8)Gd(0.2)O(2-delta) sintered at 1400 degrees C exhibited a conductivity of 0.101 S/cm at 800 degrees C in air.

  3. Oxygen Nonstoichiometry and Defect Chemistry Modeling of Ce0.8Pr0.2O2-delta

    Chatzichristodoulou, Christodoulos; Hendriksen, Peter Vang


    The oxygen nonstoichiometry (delta) of Ce0.8Pr0.2O2−delta has been measured as a function of PO2 at temperatures between 600 and 900°C by coulometric titration and thermogravimetry. An ideal solution defect model, a regular solution model, and a defect association model, taking into account...... the association of reduced dopant species and oxygen vacancies, were unable to reproduce the experimental results. However, excellent agreement with the experimentally determined oxygen nonstoichiometry could be achieved when using either a nonideal solution model with an excess enthalpic term linear in delta...... (DeltaHPrexc=aHdelta) and a completely random distribution of defects (referred to as “delta-linear”), or a “generalized delta-linear” solution model, where the excess Gibbs energy change in the reduction reaction of the dopant linearly varies with delta (DeltaGPrexc=aGdelta). A comparison of the partial...

  4. Oxygen content and microstructure in Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8+. delta

    Gonzalez-Calbet, J.M. (Dept. de Quimica Inorganica, Univ. Complutense, Madrid (Spain) Inst. de Magnetismo Aplicado, Madrid (Spain)); Caneiro, A. (Inst. de Magnetismo Aplicado, Madrid (Spain)); Ramirez, J. (Dept. de Quimica Inorganica, Univ. Complutense, Madrid (Spain)); Vallet-Regi, M. (Inst. de Magnetismo Aplicado, Madrid (Spain) Dept. de Quimica Inorganica y Bioinorganica, Univ. Complutense, Madrid (Spain))


    Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} samples with -0.06 < {delta} < 0.16 were prepared by controlled reduction in static hydrogen atmosphere and continuously monitored by thermogravimetry. Lattice parameters suggest that the 2212 superconducting phase is stable for {delta} > 0.12. ED patterns indicate that nonstoichiometry is accommodated by random distribution of anionic vacancies along the Cu-O layers. (orig.).

  5. Vortex fluctuations in underdoped Bi(2)Sr(2)CaCu(2)O(8+delta) crystals.

    Colson, Sylvain; Konczykowski, Marcin; Gaifullin, Marat B; Matsuda, Yuji; Gierłowski, Piotr; Li, Ming; Kes, Peter H; Van Der Beek, Cornelis J


    Vortex thermal fluctuations in heavily underdoped Bi(2)Sr(2)CaCu(2)O(8+delta) (T(c)=69.4 K) are studied using Josephson plasma resonance. From the zero-field data, we obtain the c-axis penetration depth lambda(L,c)(0)=230+/-10 micrometer and the anisotropy ratio gamma(T). The low plasma frequency allows us to study phase correlations over the whole vortex solid state and to extract a wandering length r(w) of vortex pancakes. The temperature dependence of r(w) as well as its increase with dc magnetic field is explained by the renormalization of the vortex line tension by the fluctuations, suggesting that this softening is responsible for the dissociation of the vortices at the first order transition.




    A detailed study of the doping dependence of valence- and core-level spectra of Bi2Sr2Ca1-xYxCu2O8+delta leads to the conclusion that the chemical potential shifts in a manner consistent with that of a simple doped semiconductor. The spectroscopically observed filling in of the gap upon doping of th

  7. Electronic Structure of TIBa(sub 2)CaCu(sub 2)O(sub 7-delta)

    Vasquez, R. P.; Novikov, D. L.; Freeman, A. J.; Siegal, M. P.


    The core levels of TIBa(sub 2)CaCu(sub 2)O(sub 7-delta) epitaxial films have been measured with x-ray photoelectron spectroscopy (XPS). The valence electronic structure has been determined using the full-potential linear muffin tin orbital band structure method and measured with XPS.

  8. Präparation, strukturelle Charakterisierung und Transporteigenschaften epitaktischer Filme der Hochtemperatursupraleiter $Bi_{2}Sr_{2}CaCu_{2}O_{8+\\delta}$ und $Bi_{2}Sr_{2}Ca_{2}Cu_{3}O_{10+\\delta}$

    Wagner, P H


    Präparation, strukturelle Charakterisierung und Transporteigenschaften epitaktischer Filme der Hochtemperatursupraleiter $Bi_{2}Sr_{2}CaCu_{2}O_{8+\\delta}$ und $Bi_{2}Sr_{2}Ca_{2}Cu_{3}O_{10+\\delta}$

  9. Vortex softening: origin of the second peak effect in Bi(2)Sr(2)CaCu(2)O(8+delta).

    Correa, V F; Nieva, G; de la Cruz, F


    Magnetic hysteresis and transverse ac permeability measurements in Bi(2)Sr(2)CaCu(2)O(8+delta) allow a comparative analysis of the critical current with the elastic response of vortex structures, in equilibrium with their pinning potential, in the field and temperature region where the second peak is detected. This study provides strong evidence that the second peak has its origin in changes of the elastic equilibrium properties of the vortex structures.

  10. Doping controlled superconductor-insulator transition in Bi2Sr2-xLaxCaCu2O8+delta.

    Oh, Seongshik; Crane, Trevis A; Van Harlingen, D J; Eckstein, J N


    We show that the doping-controlled superconductor-insulator transition (SIT) in a high critical temperature cuprate system (Bi(2)Sr(2-x)La(x)CaCu(2)O(8+delta)) exhibits a fundamentally different behavior than is expected from conventional SIT. At the critical doping, the sheet resistance seems to diverge in the zero-temperature limit. Above the critical doping, the transport is universally scaled by a two-component conductance model. Below, it continuously evolves from weakly to strongly insulating behavior. The two-component conductance model suggests that a collective electronic phase-separation mechanism may be responsible for this unconventional SIT behavior.

  11. New vortex-matter size effect observed in Bi(2)Sr(2)CaCu(2)O(8 + delta).

    Wang, Y M; Fuhrer, M S; Zettl, A; Ooi, S; Tamegai, T


    The vortex-matter 3D to 2D phase transition is studied in micron-sized Bi(2)Sr(2)CaCu(2)O(8 + delta) single crystals using local Hall magnetization measurements. At a given temperature, the second magnetization peak, the signature of a possible 3D--2D vortex phase transition, disappears for samples smaller than a critical length. We suggest that this critical length should be equated with the 2D vortex lattice ab-plane correlation length R(2D)(c). The magnitude and temperature dependence of R(2D)(c) agree well with Larkin-Ovchinnikov collective pinning theory.

  12. Bilayer splitting in the electronic structure of heavily overdoped Bi(2)Sr(2)CaCu(2)O(8+delta).

    Feng, D L; Armitage, N P; Lu, D H; Damascelli, A; Hu, J P; Bogdanov, P; Lanzara, A; Ronning, F; Shen, K M; Eisaki, H; Kim, C; Shen, Z X; Shimoyama, J; Kishio, K


    The electronic structure of heavily overdoped Bi(2)Sr(2)CaCu(2)O(8+delta) is investigated by angle-resolved photoemission spectroscopy. The long-sought bilayer band splitting in this two-plane system is observed in both normal and superconducting states, which qualitatively agrees with the bilayer Hubbard model calculations. The maximum bilayer energy splitting is about 88 meV for the normal state feature, while it is only about 20 meV for the superconducting peak.

  13. Supercooling of the disordered vortex lattice in Bi(2)Sr(2)CaCu(2)O(8+delta)

    van Der Beek CJ; Colson; Indenbom; Konczykowski


    Time-resolved local induction measurements near the vortex lattice order-disorder transition in optimally doped Bi(2)Sr(2)CaCu(2)O(8+delta) crystals show that the high-field, disordered phase can be quenched to fields as low as half the transition field. Over an important range of fields, the electrodynamical behavior of the vortex system is governed by the coexistence of ordered and disordered vortex phases in the sample. We interpret the results as supercooling of the high-field phase and the possible first-order nature of the order-disorder transition at the "second magnetization peak."

  14. Quasiparticles in the superconducting state of Bi(2)Sr(2)CaCu(2)O(8+delta)

    Kaminski; Mesot; Fretwell; Campuzano; Norman; Randeria; Ding; Sato; Takahashi; Mochiku; Kadowaki; Hoechst


    Recent improvements in momentum resolution lead to qualitatively new angle-resolved photoemission spectroscopy results on the spectra of Bi(2)Sr(2)CaCu(2)O(8+delta) (Bi2212) along the (pi,pi) direction, where there is a node in the superconducting gap. We now see the intrinsic line shape, which indicates the presence of true quasiparticles at all Fermi momenta in the superconducting state, and lack thereof in the normal state. The region of momentum space probed here is relevant for charge transport, motivating a comparison of our results to conductivity measurements by infrared reflectivity.

  15. Nodal quasiparticle lifetime in the superconducting state of Bi(2)Sr(2)CaCu(2)O(8+delta)

    Corson; Orenstein; Oh; O'Donnell; Eckstein


    We have measured the complex conductivity sigma of a Bi(2)Sr(2)CaCu(2)O(8+delta) thin film between 0.2 and 0.8 THz. We find sigma in the superconducting state to be well described as the sum of contributions from quasiparticles, condensate, and order parameter fluctuations which draw 30% of the spectral weight from the condensate. An analysis based on this decomposition yields a quasiparticle scattering rate on the order of k(B)T/Planck's over 2pi for temperatures below T(c).

  16. Electrical properties of nanocrystalline Ce(0.8)Sm(0.2)O(2-delta) and Ce(1-x)Gd(x)O(2-delta) (0.1 SOFC.

    Choi, J W; Hwang, H K; Nam, S W; Park, K


    Ce(0.8)Sm(0.2)O(2-delta) and Ce(1-x)Gd(x)O(2-delta) (0.1 < or = x < or = 0.3) nano-sized powders were successfully synthesized by the solution combustion synthesis process. The calcined nanopowders showed a ceria-based single phase with a cubic fluorite structure. In this study, we discussed the structural and electrical characteristics of the sintered Ce(0.8)Sm(0.2)O(2-delta) and Ce(1-x)Gd(x)O(2-delta). We obtained high-quality Ce(0.8)Sm(0.2)O(2-delta) and Ce(1-x)Gd(x)O(2-delta) ceramics with a high density, ultra-fine grain size, and high electrical conductivity even at low sintering temperature using the nanosized powders. The electrical conductivities at 800 degrees C for the Ce(0.8)Sm(0.2)O(2-delta) sintered at 1400 degrees C and the Ce(0.8)Gd(0.2)O(2-delta) sintered at 1350 degrees C were 0.110 and 0.104 Scm(-1), respectively.

  17. Superconductivity in 2-2-3 system Y2Ba2Cu2O(8+delta)

    Joshi, H. H.; Baldha, G. J.; Jotania, R. B.; Joshi, S. M.; Mohan, H.; Pandya, P. B.; Pandya, H. N.; Kulkarni, R. G.


    Researchers synthesized a new high T(sub c) 2-2-3 superconductor Y2Ba2Cu3O(8+delta) by a special preparation technique and characterized it by ac-susceptibility measurements. Diamagnetism and Meissner effect sets in at low fields and superconducting transition onsets at 90 K. The systematic investigation of the real and imaginary components of ac-susceptibility as a function of temperature and applied ac magnetic field reveals that the magnetic behavior is that of a granular type superconductor.

  18. Quasiparticle liquid in the highly overdoped Bi(2)Sr(2)CaCu(2)O(8+delta).

    Yusof, Z M; Wells, B O; Valla, T; Fedorov, A V; Johnson, P D; Li, Q; Kendziora, C; Jian, Sha; Hinks, D G


    Results from the study of a highly overdoped (OD) Bi(2)Sr(2)CaCu(2)O(8+delta) with a T(c) = 51 K using angle-resolved photoemission spectroscopy are presented. We observe a sharp peak in the spectra near ( pi,0) that persists well above T(c), a nodal self-energy which approaches that seen for the Mo(110) surface state, and a more k-independent line shape at the Fermi surface than the lower-doped cuprates. This allows for a realistic comparison of the lifetime values to the experimental resistivity measurements. These observations point to the validity of the quasiparticle picture for the OD even in the normal state.

  19. Evidence of chemical-potential shift with hole doping in Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8+. delta

    Shen, Z.; Dessau, D.S.; Wells, B.O. (Stanford Electronics Laboratory, Stanford University, Stanford, California 94305 (United States)); Olson, C.G. (Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States)); Mitzi, D.B.; Lombado, L. (Department of Applied Physics, Stanford University, Stanford, California 94305 (United States)); List, R.S.; Arko, A.J. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States))


    We have performed photoemission studies on high-quality Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} samples with various {delta}. Our results show a clear chemical-potential shift (0.15--0.2 eV) as a function of doping. This result and the existing angle-resolved-photoemission data give a rather standard doping behavior of this compound in its highly doped regime.

  20. Neutron Scattering Study on La1.9Ca1.1Cu2O6+delta and La1.85Sr0.15Ca Cu2O6+delta

    Hucker,M.; Kim, Y.; Gu, G.; Tranquada, J.; Gaulin, B.; Lynn, J.


    We present neutron scattering data on two single crystals of the high temperature superconductor La{sub 2-x}(Ca, Sr){sub x}CaCu{sub 2}O{sub 6+{delta}}. The Ca{sub 0.1}-doped crystal exhibits a long-range antiferromagnetically ordered ground state. In contrast, the Sr{sub 0.15}-doped crystal exhibits short-range antiferromagnetic order as well as weak superconductivity. In both crystals antiferromagnetic correlations are commensurate; however, some results on the Ca{sub 0.1}-doped crystal resemble those on the spin-glass phase of La{sub 2-x}Sr{sub x}CuO{sub 4}, where magnetic correlations became incommensurate. In addition, both crystals show a structural transition from tetragonal to orthorhombic symmetry. Quite remarkably, the temperature dependence and correlation length of the magnetic order is very similar to that of the orthorhombic distortion. We attribute this behavior to an orthorhombic strain-induced interbilayer magnetic coupling, which triggers the antiferromagnetic order. The large size of the crystals made it also possible to study the magnetic diffuse scattering along rods perpendicular to the CuO{sub 2} planes in more detail. For comparison we show x-ray diffraction and magnetization data. In particular, for the Ca{sub 0.1}-doped crystal these measurements reveal valuable information on the spin-glass transition as well as a second anomaly associated with the N{acute e}el transition.

  1. Linear and field-independent relation between vortex core state energy and gap in Bi(2)Sr(2)CaCu(2)O(8+delta).

    Hoogenboom, B W; Kadowaki, K; Revaz, B; Li, M; Renner, C; Fischer, Ø


    We present a scanning tunneling spectroscopy study on quasiparticle states in vortex cores in Bi(2)Sr(2)CaCu(2)O(8+delta). The energy of the observed vortex core states shows an approximately linear scaling with the superconducting gap in the region just outside the core. This clearly distinguishes them from conventional localized core states and is a signature of the mechanism responsible for their discrete appearance in high-temperature superconductors. The energy scaling of the vortex core states also suggests a common nature of vortex cores in Bi(2)Sr(2)CaCu(2)O(8+delta) and YBa(2)Cu(3)O(7-delta). Finally, these states do not show any dependence on the applied magnetic field between 1 and 6 T.

  2. Growth and properties of laser-ablated Bi2Sr2CaCu2O8+#delta# thin films

    Seemann, R.; Hanisch, F.; Sewing, A.;


    Thin films of Bi2Sr2CaCu2O8+delta have been fabricated by laser ablation on single crystal M(g)O (001), LaAlO3 (001) and NdGaO3 (001) substrates. The superconducting transition temperature T(C0) is above 80 K with critical current densities of 4 x 10(5) A/cm2 at 55 K. The structure and morphology...... of the films were investigated using scanning electron microscopy, scanning tunnel microscopy and X-ray diffraction. All films show c-axis orientation with a texture of less than 0.2-degrees. Films deposited on MgO (001) are mostly randomly oriented in the a, b-plane although preferential orientations...... with rotational angles of 11.5-degrees and 45-degrees were observed close to the substrate/film interface. On LaAlO3 (001) and NdGaO3 (001) substrates the a, b-plane orientation is improved and about half of the film is epitaxially oriented....

  3. How Cooper pairs vanish approaching the Mott insulator in Bi2Sr2CaCu2O8+delta.

    Kohsaka, Y; Taylor, C; Wahl, P; Schmidt, A; Lee, Jhinhwan; Fujita, K; Alldredge, J W; McElroy, K; Lee, Jinho; Eisaki, H; Uchida, S; Lee, D-H; Davis, J C


    The antiferromagnetic ground state of copper oxide Mott insulators is achieved by localizing an electron at each copper atom in real space (r-space). Removing a small fraction of these electrons (hole doping) transforms this system into a superconducting fluid of delocalized Cooper pairs in momentum space (k-space). During this transformation, two distinctive classes of electronic excitations appear. At high energies, the mysterious 'pseudogap' excitations are found, whereas, at lower energies, Bogoliubov quasi-particles-the excitations resulting from the breaking of Cooper pairs-should exist. To explore this transformation, and to identify the two excitation types, we have imaged the electronic structure of Bi(2)Sr(2)CaCu(2)O(8+delta) in r-space and k-space simultaneously. We find that although the low-energy excitations are indeed Bogoliubov quasi-particles, they occupy only a restricted region of k-space that shrinks rapidly with diminishing hole density. Concomitantly, spectral weight is transferred to higher energy r-space states that lack the characteristics of excitations from delocalized Cooper pairs. Instead, these states break translational and rotational symmetries locally at the atomic scale in an energy-independent way. We demonstrate that these unusual r-space excitations are, in fact, the pseudogap states. Thus, as the Mott insulating state is approached by decreasing the hole density, the delocalized Cooper pairs vanish from k-space, to be replaced by locally translational- and rotational-symmetry-breaking pseudogap states in r-space.

  4. Extending Universal Nodal Excitations Optimizes Superconductivity in Bi2Sr2CaCu2O8+delta

    Gu, G.; Pushp, A.; Parker, C.V.; Pasupathy, A.N.; Gomes, K.K.; Ono, S.; Wen, J.; Xu, Z.; Yazdani, A.


    Understanding the mechanism by which d wave superconductivity in the cuprates emerges and is optimized by doping the Mott insulator is one of the major outstanding problems in condensed-matter physics. Our high-resolution scanning tunneling microscopy measurements of the high-transition temperature (T{sub c}) superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} show that samples with different T{sub c} values in the low doping regime follow a remarkably universal d wave low-energy excitation spectrum, indicating a doping-independent nodal gap. We demonstrate that T{sub c} instead correlates with the fraction of the Fermi surface over which the samples exhibit the universal spectrum. Optimal T{sub c} is achieved when all parts of the Fermi surface follow this universal behavior. Increasing the temperature above T{sub c} turns the universal spectrum into an arc of gapless excitations, whereas overdoping breaks down the universal nodal behavior.

  5. Electronic structure of {delta}-Ta{sub 2}O{sub 5} with oxygen vacancy: ab initio calculations and comparison with experiment

    Ivanov, Maxim V.; Perevalov, Timofey V.; Aliev, Vladimir S.; Gritsenko, Vladimir A. [A. V. Rzhanov Institute of Semiconductor Physics SB RAS, Novosibirsk, 630090 (Russian Federation); Kaichev, Vasily V. [Boreskov Institute of Catalysis SB RAS, Novosibirsk, 630090 (Russian Federation)


    Electronic structure of oxygen vacancies in Ta{sub 2}O{sub 5} have been studied theoretically by first-principles calculations and experimentally by x-ray photoelectron spectroscopy. Calculations of {delta}-Ta{sub 2}O{sub 5} were performed using density functional theory within gradient-corrected approximation with the +U approach. Results indicate that the oxygen vacancy causes a defect level in the energy gap at 1.2 eV above the top of the valence band. To produce oxygen vacancies, amorphous films of Ta{sub 2}O{sub 5} were bombarded with Ar{sup +} ions. XPS results indicate that the Ar-ion bombardment leads to the generation of the oxygen vacancies in Ta{sub 2}O{sub 5} that characterize the peak at 2 eV above the valence band. The calculated spectrum of crystalline {delta}-Ta{sub 2}O{sub 5} demonstrates qualitative correspondence with the XPS spectrum of the amorphous Ta{sub 2}O{sub 5} film after Ar-ion bombardment.

  6. Effect of DC current polarization on the electrochemical behaviour of La{sub 2}NiO{sub 4+{delta}} and La{sub 3}Ni{sub 2}O{sub 7+{delta}}-based systems

    Perez-Coll, D.; Aguadero, A.; Escudero, M.J. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Av. Complutense 22, 28040 Madrid (Spain); Daza, L. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Av. Complutense 22, 28040 Madrid (Spain); Instituto de Catalisis y Petroleoquimica (CSIC), C/ Marie Curie 2, Campus Cantoblanco, 28049 Madrid (Spain)


    The electrode performance of La{sub 2}NiO{sub 4} and La{sub 3}Ni{sub 2}O{sub 7} as cathode materials for solid oxide fuel cells (SOFC) was analyzed. The study was focused on the electrode polarization resistance of the interfaces formed by the cathodes with Ce{sub 0.8}Sm{sub 0.2}O{sub 2-{delta}} + 2%Co electrolyte. The study was extended to cathodes based on La{sub 2}NiO{sub 4}-Ce{sub 0.8}Sm{sub 0.2}O{sub 2-{delta}} composite and Pt to analyze the effect of changing the electronic and/or ionic transport properties on the electrode interface resistance. The electrode performance was studied in open circuit conditions and with DC current polarization. Important differences in the performance of the pure cathode materials were obtained as function of DC current flux. However, in La{sub 2}NiO{sub 4}-Ce{sub 0.8}Sm{sub 0.2}O{sub 2-{delta}} composite the DC current flux produces minor changes in the electrode polarization resistance. The aging process also affects the OCV electrode performance of cathodes based on Pt and pure ceramics, whereas the effect is practically invaluable in La{sub 2}NiO{sub 4}-Ce{sub 0.8}Sm{sub 0.2}O{sub 2-{delta}} composite. The electrode performance is higher for the composite cathode compared to pure ceramic electrodes for OCV or for low values of DC polarization. However, the important decrease in the interface resistance obtained for high values of DC current flux for La{sub 2}NiO{sub 4} and La{sub 3}Ni{sub 2}O{sub 7} cathodes increases their electrode performances to values close to those obtained in La{sub 2}NiO{sub 4}-Ce{sub 0.8}Sm{sub 0.2}O{sub 2-{delta}} composite. This retains the cathode overpotential with values as low as 140 mV at 750 C for values of current load of 530 mA cm{sup -2} for both pure and composite La{sub 2}NiO{sub 4}-based cathodes. The low cathode overpotential allows to estimate values of power density between 300 and 350 mW cm{sup -2} at 750 C for La{sub 2}NiO{sub 4}, La{sub 3}Ni{sub 2}O{sub 7} and La{sub 2}Ni

  7. Stepwise behavior of vortex-lattice melting transition in tilted magnetic fields in single crystals of Bi(2)Sr(2)CaCu(2)O(8 + delta).

    Mirković, J; Savel'ev, S E; Sugahara, E; Kadowaki, K


    The vortex-lattice melting transition in Bi(2)Sr(2)CaCu(2)O(8 + delta) single crystals was studied using in-plane resistivity measurements in magnetic fields tilted away from the c axis to the ab plane. In order to avoid the surface barrier effect which hinders the melting transition in the conventional transport measurements, we used the Corbino geometry of electric contacts. The complete H(c) - H(ab) phase diagram of the melting transition in Bi(2)Sr(2)CaCu(2)O(8 + delta) is obtained for the first time. The c-axis melting field component H(c)(melt) exhibits the novel, stepwise dependence on the in-plane magnetic fields H(ab) which is discussed on the basis of the crossing vortex-lattice structure. The peculiar resistance behavior observed near the ab plane suggests the change of phase transition character from first to second order.

  8. Influence of oxygen stoichiometry on Tc and pinning force of Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8+. delta

    Vallet-Regi, M. (Dept. de Quimica Inorganica y Bioinorganica, Univ. Complutense, Madrid (Spain) Inst. de Magnetismo Aplicado, Madrid (Spain)); Caneiro, A. (Inst. de Magnetismo Aplicado, Madrid (Spain)); Gonzalez-Calbet, J.M. (Inst. de Magnetismo Aplicado, Madrid (Spain) Dept. de Quimica Inorganica, Univ. Complutense, Madrid (Spain)); Ramirez, J. (Dept. de Quimica Inorganica, Univ. Complutense, Madrid (Spain)); Rillo, C.; Badia, A.; Angurel, L.A.; Lera, F.; Navarro, R. (I.C.M.A., C.S.I.C.-Univ. de Zaragoza (Spain))


    The influence of oxygen stoichiometry in Tc and F{sub p} of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} has been investigated by means of X-ray and electron diffraction, a.c. susceptibility and d.c. magnetization. Through proper oxygen control, Tc=94 K and an increase of one order of magnitude in F{sub p} with respect to the started material has been achieved. (orig.).

  9. On the thermodynamic stability of La{sub 2}Mo{sub 2}O{sub 9-{delta}} oxide-ion conductor

    Vega-Castillo, J.; Mogni, L. [Intituto Balseiro, Centro Atomico Bariloche, 8400 San Carlos de Bariloche, Rio Negro (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas CONICET (Argentina); Corbel, G.; Lacorre, P. [Laboratoire des Oxydes et Fluorures, UMR-6010 CNRS, Universite du Maine, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9 (France); Caneiro, A. [Intituto Balseiro, Centro Atomico Bariloche, 8400 San Carlos de Bariloche, Rio Negro (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas CONICET (Argentina); Comision Nacional de Energia Atomica CNEA (Argentina)


    The stability of La{sub 2}Mo{sub 2}O{sub 9-{delta}} oxide-ion conductor was studied under Ar-H{sub 2} and controlled oxygen partial pressure (pO{sub 2}) atmospheres within the range 608 {<=} T {<=} 1000 C, by thermogravimetry (TG), X-ray Diffraction (XRD), Temperature Controlled X-ray Diffraction (TCXRD) and Scanning Electron Microscopy (SEM). At 608 C under Ar-H{sub 2} flowing atmosphere, La{sub 2}Mo{sub 2}O{sub 9} phase was found to be unstable and reduction leads to an amorphous phase with composition close to La{sub 2}Mo{sub 2}O{sub 6.88}. The stability of this amorphous phase under Ar-H{sub 2} was analyzed by TCXRD and found to be stable below 900 C. Isothermal TG under controlled pO{sub 2} at 1000 C indicated that La{sub 2}Mo{sub 2}O{sub 9-{delta}} is not stable below 10{sup -7} Pa and decomposition took place without the formation of La{sub 7}Mo{sub 7}O{sub 30} or amorphization. (author)

  10. Raman scattering, magnetization and magnetotransport study of SrFeO{sub 3-{delta}}, Sr{sub 3}Fe{sub 2}O{sub 7-{delta}} and CaFeO{sub 3}

    Damljanovic, Vladimir


    In this thesis we have determined the Raman spectra as well as the magnetization, resistance and magnetoresistance of the compounds SrFeO{sub 3-{delta}}, Sr{sub 3}Fe{sub 2}O{sub 7-{delta}} and CaFeO{sub 3} as a function of temperature. We describe the preparation of nearly stoichiometric SrFeO{sub 3-{delta}} crystals with {delta}<0.05. we have performed lattice dynamics calculations for the ideal composition SrFeO{sub 3.00} in order to assign the phonon modes observed in infra-red experiments. We have measured the Raman spectra of the tetragonal phase in the temperature range 13 K to 300 K and of the orthorhombic phase in the temperature range 6 K to 475 K. We have measured the temperature dependence of the magnetization for the magnetic field along high-symmetry axes of the crystal structure. We have also performed neutron diffraction measurements. The resistivity and the magnetoresistance were measured in the range 10 K to 300 K. Finally we have measured the Raman spectra of the same sample in the temperature range 15 K to 440 K. In order to assign the observed modes, we have performed lattice dynamics calculations based on the published crystal structure of Sr{sub 3}Fe{sub 2}O{sub 7}. (orig.)

  11. Sr{sup 2+} doping effects on the transport and magnetic properties of GdBaCo{sub 2}O{sub 5+{delta}}

    Janaki, J. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India. (India)], E-mail:; Bharathi, A.; Gayathri, N.; Yasodha, P.; Premila, M.; Sastry, V.S.; Hariharan, Y. [Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India. (India)


    Studies on some new members of the cobalt perovskite Gd{sub 1-x}Sr{sub x}BaCo{sub 2}O{sub 5+{delta}} with low strontium concentrations (02}O{sub 5+{delta}} system by hole doping. Low temperature electrical resistivity, magnetic susceptibility and thermopower of the above system have been studied. The pristine compound with x=0 and {delta}{approx}0.5 exhibits a semiconductor-like behavior and two magnetic transitions below room temperature. Upon Sr{sup 2+} substitution, there is a fall in resistivity by 2-3 orders of magnitude at low temperature and also a dramatic reduction in the ferromagnetic to antiferromagnetic transition temperature. These changes can be explained on the basis of hole doping (and increase in the Co{sup 4+}content). Evidence for an increase in Co{sup 4+} with Sr{sup 2+} substitution is provided by iodometric analysis.

  12. Crystal structure analysis and chiral recognition study of Delta-[Ru(bpy)2(py)2][(+)-O,O'-dibenzoylD-tartrate].12H2O and Lambda-[Ru(bpy)2(py)2][(-)-O,O'-dibenzoyl-L-tartrate].12H2O.

    Kolp, B; Viebrock, H; von Zelewsky, A; Abeln, D


    The molecular structure and crystal-packing mode of the enantiopure chiral building blocks Delta-[Ru(bpy)(2)(py)(2)][(+)-O,O'-dibenzoyl-D-tartrate].12H(2)O (I) and Lambda-[Ru(bpy)(2)(py)(2)][(-)-O,O'-dibenzoyl-L-tartrate].12H(2)O (II) have been determined by single-crystal X-ray diffraction data. This study proposes a model of how the L- and D-dibenzoyltartrate anions recognize the chirality of the hydrophobic [Ru(bpy)(2)(py)(2)](2+) complex. The monoclinic unit cell contains four complex cations, four tartrate anions, and 48 water molecules. Since there are no possibilities to form hydrogen bonds between the cations and anions, chiral recognition is due to crystal packing. Two benzoyl rings of two different tartrate anions are gripping the two bpy-planes of the Ru-complex. Further a third benzoyl ring from a tartrate anion is packed between the two pyridine rings, favoring one enantiomeric form to crystallize from aqueous solution. Crystal structure data for I at 153 K: a = 15.342(3) A, b = 19.200(4) A, c = 18.872(4) A, beta = 104.841(3) degrees, monoclinic space group C(2), R(1)= 0.0239 (I > 2sigma(I)), R(2) = 0.0606, Flack parameter = 0.0115 (with esd 0.0166). For II at 293 K: a = 15.376(4) A, b = 19.388(11) A, c = 19.085(7) A, beta = 105.11(2) degrees, monoclinic space group C121, R(1)= 0.0686 (I > 2sigma(I)), R(2) = 0.1819, Flack parameter = -0.0100 (with esd 0.0521).

  13. Oxygen ordering in the high-T$_c$ superconductor HgBa$_2$CaCu$_2$O$_{6+\\delta}$ as revealed by perturbed angular correlation

    Mendonca, Tania Melo; Haas, Heinz; Odier, Philippe; Tavares, Pedro; Silva, Manuel Ribeiro; Lopes, Armandina; Pereira, Andre; Goncalves, Joao Nuno; Amaral, Joao; Darie, Celine; Araujo, Joao Pedro


    Lattice sites and collective ordering of oxygen atoms in HgBa$_2$CaCu$_2$O$_{6+\\delta}$ were studied using the perturbed angular correlation (PAC) technique at ISOLDE/CERN. The electric field gradients (EFG) at $^{199m}$Hg nuclei have been measured as functions of oxygen doping on the Hg planes, above and below T$_c$. In comparison with the results obtained for oxygen and fluorine doping in Hg-1201, the analysis shows a different oxygen ordering exhibited by Hg-1212. Moreover, for all studied cases, the experimental results show that at a local scale there is non-uniform oxygen distribution. A series of ab initio EFG calculations allowed to infer that at low concentrations, regions without oxygen coexist with regions where O$_{2\\delta}$ dumbbell molecules are located at the center of the Hg mesh. On the other side, at high concentrations, O$_{2\\delta}$ dumbbell molecules coexist with single O$_\\delta$ atoms occupying the center of the Hg mesh. The present results suggest that oxygen sits on the Hg planes in t...

  14. Angle - resolved - photoemission study of Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8+. delta. : Metallicity of the Bi-O plane

    Wells, B.O.; Shen, Z.; Dessau, D.S.; Spicer, W.E.; Olson, C.G.; Mitzi, D.B.; Kapitulnik, A.; List, R.S.; Arko, A. (Stanford Electronics Laboratories, Stanford University, Stanford, CA (USA) Ames Laboratory, Iowa State University, Ames, IA Department of Applied Physics, Stanford University, Stanford, CA (USA) Los Alamos National Laboratory, Los Alamos, NM (USA))


    We have performed high-resolution angle-resolved-photoemission experiments on Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} single crystals with different annealing histories. By depositing a small amount of Au on the surface, we were able to distinguish electronic states associated with the Bi-O surface layer. We found that the Bi-O atomic surface layer is metallic and superconducting for samples that were high-temperature annealed in oxygen but not for as-grown samples. The Cu-O plane is found to be superconducting in all samples.

  15. Atomic scale imaging and spectroscopy of a CuO(2) plane at the surface of Bi(2)Sr(2)CaCu(2)O(8+delta).

    Misra, S; Oh, S; Hornbaker, D J; DiLuccio, T; Eckstein, J N; Yazdani, A


    We have used a scanning tunneling microscope to demonstrate that a single CuO2 plane can form a stable and atomically ordered layer at the surface of Bi(2)Sr(2)CaCu(2)O(8+delta). In contrast to previous studies on high-T(c) surfaces, the CuO2-terminated surface exhibits a strongly suppressed tunneling conductance at low voltages. We consider a number of different explanations for this phenomena and propose that it may be caused by how the orbital symmetry of the CuO2 plane's electronic states affects the tunneling process.

  16. Evidence for quantum critical behavior in the optimally doped cuprate Bi(2)Sr(2)CaCu(2)O(8+delta)

    Valla; Fedorov; Johnson; Wells; Hulbert; Li; Gu; Koshizuka


    The photoemission line shapes of the optimally doped cuprate Bi(2)Sr(2)CaCu(2)O(8+delta) were studied in the direction of a node in the superconducting order parameter by means of very high resolution photoemission spectroscopy. The peak width or inverse lifetime of the excitation displays a linear temperature dependence, independent of binding energy, for small energies, and a linear energy dependence, independent of temperature, for large binding energies. This behavior is unaffected by the superconducting transition, which is an indication that the nodal states play no role in the superconductivity. Temperature-dependent scaling suggests that the system displays quantum critical behavior.

  17. Signature of superfluid density in the single-particle excitation spectrum of Bi(2)Sr(2)CaCu(2)O(8+delta)

    Feng; Lu; Shen; Kim; Eisaki; Damascelli; Yoshizaki; Shimoyama; Kishio; Gu; Oh; Andrus; O'Donnell; Eckstein; Shen


    We report that the doping and temperature dependence of photoemission spectra near the Brillouin zone boundary of Bi(2)Sr(2)CaCu(2)O(8+delta)exhibit unexpected sensitivity to the superfluid density. In the superconducting state, the photoemission peak intensity as a function of doping scales with the superfluid density and the condensation energy. As a function of temperature, the peak intensity shows an abrupt behavior near the superconducting phase transition temperature where phase coherence sets in, rather than near the temperature where the gap opens. This anomalous manifestation of collective effects in single-particle spectroscopy raises important questions concerning the mechanism of high-temperature superconductivity.

  18. STM studies of the electronic structure of vortex cores in Bi(2)Sr(2)CaCu(2)O(8+delta)

    Pan; Hudson; Gupta; Ng; Eisaki; Uchida; Davis


    We report on low temperature scanning tunneling microscopy (STM) studies of the electronic structure of vortex cores in Bi 2Sr 2CaCu 2O (8+delta). At the vortex core center, an enhanced density of states is observed at energies near Omega = +/-7 meV. Spectroscopic imaging at these energies reveals an exponential decay of these "core states" with a decay length of 22+/-3 A. The fourfold symmetry sometimes predicted for d-wave vortices is not seen in spectroscopic vortex images. A locally nodeless order parameter induced by the magnetic field may be consistent with these measurements.

  19. Crossover from coherent to incoherent electronic excitations in the normal state of Bi(2)Sr(2)CaCu(2)O(8+delta).

    Kaminski, A; Rosenkranz, S; Fretwell, H M; Li, Z Z; Raffy, H; Randeria, M; Norman, M R; Campuzano, J C


    Angle resolved photoemission spectroscopy (ARPES) and resistivity measurements are used to explore the overdoped region of the high temperature superconductor Bi(2)Sr(2)CaCu(2)O(8+delta). We find evidence for a new crossover line in the phase diagram between a coherent metal phase, for lower temperatures and higher doping, and an incoherent metal phase, for higher temperatures and lower doping. The former is characterized by two well-defined spectral peaks in ARPES due to coherent bilayer splitting and superlinear behavior in the resistivity, whereas the latter is characterized by a single broad spectral feature in ARPES and a linear temperature dependence of the resistivity.

  20. Doping and temperature dependence of the mass enhancement observed in the cuprate Bi(2)Sr(2)CaCu(2)O(8+delta).

    Johnson, P D; Valla, T; Fedorov, A V; Yusof, Z; Wells, B O; Li, Q; Moodenbaugh, A R; Gu, G D; Koshizuka, N; Kendziora, C; Jian, S; Hinks, D G


    High-resolution photoemission is used to study the electronic structure of the cuprate superconductor, Bi(2)Sr(2)CaCu(2)O(8+delta), as a function of hole doping and temperature. A kink observed in the band dispersion in the nodal line in the superconducting state is associated with coupling to a resonant mode observed in neutron scattering. From the measured real part of the self-energy it is possible to extract a coupling constant which is largest in the underdoped regime, then decreasing continuously into the overdoped regime.

  1. Doping-induced change in the interlayer transport mechanism of Bi_{2}Sr_{2}CaCu_{2}O_{8+delta} near the superconducting transition temperature.

    Katterwe, S O; Rydh, A; Krasnov, V M


    We perform a detailed study of temperature, bias, and doping dependence of interlayer transport in the layered high temperature superconductor Bi_{2}Sr_{2}CaCu_{2}O_{8+delta}. We observe that the shape of interlayer characteristics in underdoped crystals exhibits a remarkable crossover at the superconducting transition temperature: from thermal activation-type above T_{c} to almost T-independent quantum tunneling-type below T_{c}. Our data provide insight into the nature of interlayer transport and indicate that its mechanism changes with doping: from the conventional single quasiparticle tunneling in overdoped to a progressively increasing Cooper pair contribution in underdoped crystals.

  2. Temperature dependent scattering rates at the fermi surface of optimally doped Bi(2)Sr(2)CaCu(2)O(8+delta)

    Valla; Fedorov; Johnson; Li; Gu; Koshizuka


    For optimally doped Bi(2)Sr(2)CaCu(2)O(8+delta), scattering rates in the normal state are found to have a linear temperature dependence over most of the Fermi surface. In the immediate vicinity of the (pi, 0) point, the scattering rates are nearly constant in the normal state, consistent with models in which scattering at this point determines the c-axis transport. In the superconducting state, the scattering rates away from the nodal direction appear to level off and become temperature independent.

  3. Scanning Josephson tunneling microscopy of single-crystal Bi_{2}Sr_{2}CaCu_{2}O_{8+delta} with a conventional superconducting tip.

    Kimura, Hikari; Barber, R P; Ono, S; Ando, Yoichi; Dynes, R C


    We have performed both Josephson and quasiparticle tunneling in vacuum tunnel junctions formed between a conventional superconducting scanning tunneling microscope tip and overdoped Bi_{2}Sr_{2}CaCu_{2}O_{8+delta} single crystals. A Josephson current is observed with a peak centered at a small finite voltage due to the thermal-fluctuation-dominated superconducting phase dynamics. Josephson measurements at different surface locations yield local values for the Josephson I_{C}R_{N} product. Corresponding energy gap measurements were also performed and a surprising inverse correlation was observed between the local I_{C}R_{N} product and the local energy gap.

  4. Electronic standing waves on the surface of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}

    Vershinin, M.; Misra, S.; Abe, Y.; Ono, S.; Ando, Y.; Yazdani, A


    Scanning tunneling microscopy (STM) measurements have shown that electronic states at the surface of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} single crystals form standing wave patterns at temperatures far below the superconducting transition. It has been shown that these patterns are consistent with those expected from the interference of well-defined quasi-particles around the Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} Fermi surface. We have extended STM measurements of these standing wave patterns to higher temperatures and have found that four unit-cell periodicity patterns observed in the superconducting state persist well above T{sub C}, in the pseudogap state. In this regime, many different experimental studies of the cuprates have long claimed the absence of well-defined quasi-particles. If the pseudogap regime is indeed devoid of any coherent quasi-particles then our results suggest that other phenomena, such as stripe formation, must play a role in formation of these patterns.

  5. Oxygen desorption from YBa2Cu3O(7-x) and Bi2CaSr2Cu2O(8 + delta) superconductors

    Mesarwi, A.; Levenson, L. L.; Ignatiev, A.


    Oxygen desorption experiments from YBa2Cu3O(7-x) (YBCO) and Bi2CaSr2Cu2O(8 + delta) (BSCCO) superconductors were carried out using a quadrupole mass spectrometer for monitoring the desorbing species and X-ray photoemission spectroscopy for surface characterization. Molecular oxygen was found to desorb from both superconductors following photoirradiation with ultraviolet/optical radiation and subsequent heating at over 150 C. Both YBCO and BSCCO were found to have similar oxygen desorption rates and similar activation energies. The desorption data as well as the X-ray photoemission data indicate that the oxygen desorption is not intrinsic to the superconductors but rather due to molecular oxygen entrapped in the material.

  6. Anomalous spectral weight transfer at the superconducting transition of Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8+. delta

    Dessau, D.S.; Wells, B.O.; Shen, Z.; Spicer, W.E. (Stanford Electronics Laboratories, Stanford University, Stanford, California 94305 (USA)); Arko, A.J.; List, R.S. (Los Alamos National Laboratories, Los Alamos, New Mexico 87545 (USA)); Mitzi, D.B.; Kapitulnik, A. (Department of Applied Physics, Stanford University, Stanford, California 94305 (USA))


    Anomalous spectral weight transfer at the superconducting transition of single-crystalline Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} was observed by high-resolution angle-resolved photoemission spectroscopy. As the sample goes superconducting, not only is there spectral weight transfer from the gap region to the pileup peak as in BCS theory, but along the {Gamma}-{ital {bar M}} direction there is also some spectral weight transfer from higher binding energies in the form of a dip. In addition, we note that at the superconducting transition there is a decrease (increase) in the occupied spectral weight for the spectra taken along {Gamma}-{ital {bar M}} ({Gamma}-{ital X}).

  7. Perturbed angular correlations studies in the HgBa$_2$CaCu$_2$O$_{6+\\delta}$ high-T$_c$ superconductor

    Mendonca, Tania Melo; Haas, Heinz; Odier, Philippe; Tavares, Pedro; SIlva, Manuel Ribeiro; Lopes, Armandina; Darie, Celine; Araujo, Joao Pedro


    The electric field gradients at $^{199m}$Hg nuclei have been measured via the perturbed angular correlation (PAC) technique, allowing a full characterization of the Hg neighborhood charge distribution at high oxygen doping on the Hg planes. The PAC technique has been applied to investigate the effect of high oxygen pressure during the measurement. Polycrystalline HgBa$_2$CaCu$_2$O$_{6+\\delta}$ (Hg-1212) samples have been annealed at 152 bar pressurized oxygen. The influence of oxygen pressure during the experiment was then investigated by measuring the samples at atmospheric pressure and under 152 bar oxygen pressure. The present set of PAC experiments shows that at high oxygen concentrations there is a non-uniform oxygen distribution. Moreover, the Hg environment is not free from oxygen and the results hint to a new type of ordering.

  8. Ultrafast electron relaxation in superconducting Bi(2)Sr(2)CaCu(2)O(8+delta) by time-resolved photoelectron spectroscopy.

    Perfetti, L; Loukakos, P A; Lisowski, M; Bovensiepen, U; Eisaki, H; Wolf, M


    Time-resolved photoelectron spectroscopy is employed to study the dynamics of photoexcited electrons in optimally doped Bi{2}Sr{2}CaCu{2}O{8+delta} (Bi-2212). Hot electrons thermalize in less than 50 fs and dissipate their energy on two distinct time scales (110 fs and 2 ps). These are attributed to the generation and subsequent decay of nonequilibrium phonons, respectively. We conclude that 20% of the total lattice modes dominate the coupling strength and estimate the second momentum of the Eliashberg coupling function lambdaOmega{0}{2}=360+/-30 meV{2}. For the typical phonon energy of copper-oxygen bonds (Omega{0} approximately 40-70 meV), this results in an average electron-phonon coupling lambda<0.25.

  9. Absence of a loss of in-plane infrared spectral weight in the pseudogap regime of Bi(2)Sr(2)CaCu(2)O(8+delta).

    Santander-Syro, A F; Lobo, R P S M; Bontemps, N; Konstantinovic, Z; Li, Z; Raffy, H


    The ab-plane reflectance of Bi(2)Sr(2)CaCu(2)O(8+delta) (Bi-2212) thin films was measured in the 30-25 000 cm(-1) range for one underdoped ( T(c) = 70 K), and one overdoped sample ( T(c) = 63 K) down to 10 K. We find similar behaviors in the temperature dependence of the normal-state infrared response of both samples. Above T(c), the effective spectral weight, obtained from the integrated conductivity, does not decrease when T decreases, so that no opening of an optical pseudogap is seen. We suggest that these are consequences of the pseudogap opening in the k = (0,pi) direction and of the in-plane infrared conductivity being mostly sensitive to the k = (pi,pi) direction.

  10. Abrupt change of josephson plasma frequency at the phase boundary of the bragg glass in Bi(2)Sr(2)CaCu(2)O(8+delta)

    Gaifullin; Matsuda; Chikumoto; Shimoyama; Kishio


    We report the first detailed and quantitative study of the Josephson coupling energy in the vortex liquid, Bragg glass, and vortex glass phases of Bi(2)Sr(2)CaCu(2)O(8+delta) by the Josephson plasma resonance. The measurements revealed distinct features in the T and H dependencies of the plasma frequency omega(pl) for each of these three vortex phases. When going across either the Bragg-to-vortex glass or the Bragg-to-liquid transition line, omega(pl) shows a dramatic change. We provide a quantitative discussion on the properties of these phase transitions, including the first order nature of the Bragg-to-vortex glass transition.

  11. Processing and characterization of screen printing Ba$_{0.5}$Sr$_{0.5}$Co$_{0.8}$Fe$_{0.2}$O$_{3−\\delta}$ inks



    Oxygen-selective membranes based on thin layers of barium–strontium–cobalt ferrite Ba$_{0.5}Sr$_{0.5}$Co$_{0.8}$Fe$_{0.2}O$_{3−\\delta}$ (BSCF) perovskite oxide were manufactured. Five BSCF inks prepared with differentcarriers and milling treatments were rheologically characterized, screen printed on three different porous alumina substrates and sintered at 1050 and 1150$^{\\circ}$C. The resulting membranes were characterized. The data collected on the rheological properties of inks (flow curves, thixotropic behaviour, linear viscoelasticity), their processability by screen printing, and the quality of the layers obtained after sintering represents an important starting point to set up the next research activities.

  12. Novel anisotropy in the superconducting gap structure of Bi2Sr2CaCu2O(8+delta) probed by quasiparticle heat transport.

    Ando, Yoichi; Takeya, J; Abe, Yasushi; Sun, X F; Lavrov, A N


    Since the nature of pairing interactions is manifested in the superconducting gap symmetry, the exact gap structure, particularly any deviation from the simple d(x(2)-y(2)) symmetry, would help in elucidating the pairing mechanism in high- T(c) cuprates. Anisotropic heat transport measurement in Bi(2)Sr(2)CaCu(2)O(8+delta) reveals that the quasiparticle populations are different for the two nodal directions and thus the gap structure must be uniquely anisotropic, suggesting that pairing is governed by interactions with a rather complicated anisotropy. Intriguingly, it is found that the "plateau" in the magnetic-field dependence of the thermal conductivity is observed only in the b-axis transport.

  13. Self-Assembly of Two Chiral Supramolecules with Three-Dimensional Porous Host Frameworks: (Delta){[Fe(II)(phen)(3)][Fe(III)Na(C(2)O(4))(3)]}(n)() and Its Enantiomer.

    Li, Pei-zhou; Lu, Xiao-ming; Liu, Bo; Wang, Shuo; Wang, Xiao-jun


    Two chiral supramolecules with enantiomeric three-dimensional porous host frameworks, (Delta){[Fe(II)(phen)(3)][Fe(III)Na(C(2)O(4))(3)]}(n) (1) and (Lambda){[Fe(II)(phen)(3)][Fe(III)Na(C(2)O(4))(3)]}(n) (2) (phen = 1,10-phenanthroline), have been synthesized, and their crystal structures have been determined. The structural analysis shows that compounds 1 and 2 are a pair of enantiomers, both consisting of a three-dimensional porous skeleton formed by (Delta)/(Lambda){[Fe(III)Na(C(2)O(4))(3)](2-)}(n) and guest (Delta)/(Lambda)[Fe(phen)(3)](2+) units. The circular dichroism spectrum measurements confirmed the optical activity and the enantiomeric nature of complexes 1 and 2.

  14. Inter-plane coupling in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}: impact of disorder and of magnetic field; Couplage interplan dans Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}: effet du desordre et du champ magnetique

    Spathis, P


    The first part of this work is dedicated to the impact of structure disorder on the superconducting properties of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}. The quantity of disorder has been monitored through the irradiation with 2.5 MeV electrons. The Josephson plasma resonance has enabled us to study the impact of disorder on the inter-plan coupling. The second part is devoted to the properties of the mixed state of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}. When a magnetic field is applied transversely, it generates, for low inductions, a network of quantized flux lines called vortexes. The lamellar nature of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} implies that the vortexes generated are a piling up of low interacting magnetic dipoles. It is now well proved that inside the mixed phase, the solid vortex phase turns itself into a vortex liquid through a first order phase transformation. When the magnetic field is applied longitudinally to the CuO{sub 2} planes, a part of supra-currents are generated through Josephson effect. The consecutive vortexes are called Josephson vortexes and their cores are located between 2 superconducting planes. The first chapter recalls essential features of superconductivity and highlights the lamellar structure of cuprates. The second chapter describes the resonant cavity perturbation technique. The 2 last chapters deal respectively with the impact of energetic electron irradiation and with the impact of a slanting magnetic field on the phase coherence. (A.C.)

  15. Spectral weight changes at the superconducting transition of Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8+. delta

    Dessau, D.S.; Shen, Z.X.; Wells, B.O.; Spicer, W.E. (Stanford Univ., CA (United States). Stanford Electronics Labs.); Arko, A.J. (Los Alamos National Lab., NM (United States))


    An overview of our gap studies in high-{Tc} superconductors is presented for the workshop on Fermiology of high-{Tc}'s. The work is centered on the study of single crystal Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}. In a conventional BCS superconductor, a superconducting gap {Delta} is formed when the near Fermi edge electrons condense to form Cooper pairs at low temperatures. As the material goes superconducting the density of states is modified such that the spectral intensity in the region from the Fermi energy down to an energy {Delta} is transferred to a regions just below {Delta}. While this spectral weight transfer has in the past been studied with tunneling spectroscopy, the size of the gap as well as improvements in our instrument resolution allow us now to study it with photoelectron spectroscopy. We have found that as the sample goes superconducting, not only is there spectral weight transfer from the gap region as in BCS theory, but along the {Gamma}-M direction there is also some spectral weight transfer from higher binding energies resulting in a dspectral dip at about {minus}90 meV relative E{sub F}. The total spectral weight decreases along the {Gamma}-M direction, but actually increases along the {Gamma}-X direction. This temperature dependent spectral transfer is discussed in terms of (1) a two to three dimensional phase transition from RVB theory; (2) a manifestation of the electron-boson interaction in the form of {alpha}{sup 2}F oscillations; and (3) conformity with the theory of Van Hove singularities. The latter are particularly attractive in that there are several other observations possibly explained by them: (1) the observation that the magnitude of the gap is anisotropic in the a-b plane; (2) the observation that for overdoped samples the magnitude of D appears to fall off faster then {Tc}. 25 refs., 8 figs., 1 tab.

  16. Anomalously large gap anisotropy in the [ital a]-[ital b] plane of Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8+[delta

    Shen, Z.; Dessau, D.S.; Wells, B.O.; King, D.M.; Spicer, W.E.; Arko, A.J.; Marshall, D.; Lombardo, L.W.; Kapitulnik, A.; Dickinson, P.; Doniach, S.; DiCarlo, J.; Loeser, T.; Park, C.H. (Department of Applied Physics, Stanford University, Stanford, California 94305 (United States) Solid State Electronics Laboratory and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305-4055 (United States) Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States))


    Superconducting gap anisotropy at least an order of magnitude larger than that of the conventional superconductors has been observed in the [ital a]-[ital b] plane of Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8+[delta

  17. Oxygen nonstoichiometry and properties of lanthanum nickelates La{sub 3-x}Ca{sub x}Ni{sub 2}O{sub 7-{delta}} (0 {<=} x {<=} 2.0)

    Nedilko, S.A.; Kulichenko, V.A.; Dziazko, A.G.; Zenkovich, E.G


    Complex rare-earth nickelates La{sub 3-x}Ca{sub x}Ni{sub 2}O{sub 7-{delta}} (0{<=}x{<=}2.0) were produced using coprecipitation followed by calcination of the obtained blend. We have determined the stability range for the solid solution and the fraction {delta} of non-stoichiometric oxygen, using powder X-ray diffraction and chemical analysis. It is shown that the stability range for these solid solutions correlates with the oxygen content in the samples. Substitution of lanthanum by calcium changed the conductivity type from metal (x=0) to semiconductor (0.2{<=}x{<=}0.8)

  18. Study of LnBaCo{sub 2}O{sub 6-d}elta (Ln = Pr, Nd, Sm and Gd) double perovskites as new cathode material for IT-SOFC

    Chavez, E; Mueller, M; Mogni, L; Caneiro, A, E-mail: [Centro Atomico Bariloche-CNEA, Instituto Balseiro. Av. Bustillo 9500, S. C. de Bariloche 8400 (Argentina)


    Oxides with double perovskites structures of general composition LnBaCo{sub 2}O{sub 6-d}elta (Ln = Pr, Nd, Sm and Gd) were synthesized by solid state reaction with the purpose to evaluate new materials to be used as cathodes in intermediate temperature solid oxide fuel cell (IT-SOFC). A preliminary study about electrochemical properties was performed by impedance spectroscopy between 500 and 800 deg. C under atmosphere of pure O{sub 2}. Symmetrical cells were obtained by spray deposition of LnBaCo{sub 2}O{sub 6-d}elta (Ln = Pr, Nd, Sm and Gd) at both sides of a dense ceramic electrolyte. The impedance spectroscopy measurements as a function of temperatures show a hysteresis loop which could be associated to a tetragonal/orthorhombic phase transition. The existence of this transition was corroborated by high temperature X-Ray diffraction and Differential Scanning Calorimetry measurements.

  19. Conductivity and tunneling in epitaxial Bi{sub 2}Sr{sub 2}Ca{sub 1-x}Y{sub x}Cu{sub 2}O{sub 8+{delta}} thin films

    Baca, E.; Salinas, A.; Holguin, V.; Prieto, P. [Valle Univ., Cali (Colombia). Dept. de Fisica


    We performed a study on the preparation conditions and transport properties of Bi{sub 2}Sr{sub 2}Ca{sub 1-x}Y{sub x}Cu{sub 2}O{sub 8+{delta}} thin films, and carried out tunneling measurements in planar type junctions using a Bi{sub 2}Sr{sub 2}YCu{sub 2}O{sub 8+{delta}} (22Y2, for x = 1.00) layer for the insulation of two Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (2212, for x = 0.00) electrodes. The deposition of the films was carried out by a high oxygen pressure DC-sputtering technique. By increasing the yttrium content x the temperature dependence of the electrical resistivity changes from a metallic to an insulating behavior. Our measurements show a decrease in the critical temperature T{sub c} with increasing yttrium content. An energy gaplike structure near 45 meV was observed in the planar-type junctions. The zero bias anomaly observed is interpreted in terms of the Anderson-Appelbaum model. (orig.)

  20. Thermal expansion of layered cobaltites Y(Ba{sub 1-x}Sr{sub x})Co{sub 2}O{sub 5+{delta}} with x = 0, 0.05 and 0.10

    Aurelio, G; Bustingorry, S; Sanchez, R D [Consejo Nacional de Investigaciones CientIficas y Tecnicas, Centro Atomico Bariloche-Comision Nacional de EnergIa Atomica, Av. Bustillo 9500, 8400 S. C. de Bariloche, RN (Argentina); Cuello, G J, E-mail: [Institut Laue-Langevin, F-38042 Grenoble (France)


    The crystal structure and thermal expansion of Sr-doped layered cobaltites Y(Ba{sub 1-x}Sr{sub x})Co{sub 2}O{sub 5+{delta}} (x = 0, 0.05 and 0.10) were studied by means of in situ neutron thermodiffraction in the temperature range 20 K {<=} T {<=} 570 K. The evolution with temperature of lattice parameters for the phases which crystallize in this system is presented, as well as their dependence on the oxygen non-stoichiometry {delta}. Each phase's volume has been fitted using available models based on the Grueneisen approximation to the zero-pressure equation of state and using the Ruffa model based on the Morse potential, both using a Debye model for the internal energy. The coefficient of volumetric thermal expansion, Debye temperature and other thermodynamic parameters are presented and compared with other perovskite compounds.

  1. Evidence for a pseudogap in underdoped Bi{2}Sr_{2}CaCu{2}O{8+delta} and YBa2Cu3O6.50 from in-plane optical conductivity measurements.

    Hwang, J; Carbotte, J P; Timusk, T


    The real part of the in-plane optical self-energy data in underdoped Bi_{2}Sr_{2}CaCu_{2}O_{8+delta} (Bi-2212) and ortho II YBa2Cu3O6.5 contains new and important information on the pseudogap. Using a theoretical model approach, a major new finding is that states lost below the pseudogap Delta_{pg} are accompanied by a pileup of states just above this energy. The pileup along with a sharp mode in the bosonic spectral function leads to an unusually rapid increase in the optical scattering rate as a function of frequency and a characteristically sloped peak in the real part of the optical self-energy. These features are not found in optimally doped and overdoped samples and represent the clearest signature so far in the in-plane optical conductivity of the opening of a pseudogap.

  2. Circular dichroism in the angle-resolved photoemission spectrum of the high-temperature Bi_{2}Sr_{2}CaCu_{2}O_{8+delta} superconductor: can these measurements be interpreted as evidence for time-reversal symmetry breaking?

    Arpiainen, V; Bansil, A; Lindroos, M


    We report first-principles computations of the angle-resolved photoemission response with circularly polarized light in Bi_{2}Sr_{2}CaCu_{2}O_{8+delta} for the purpose of delineating contributions to the circular dichroism resulting from distortions and modulations of the crystal lattice. Comparison with available experimental results shows that the measured circular dichroism from antinodal mirror planes is reproduced in quantitative detail in calculations employing the average orthorhombic crystal structure. We thus conclude that the existing angle-resolved photoemission measurements can be understood essentially within the framework of the conventional picture, without the need to invoke unconventional mechanisms.

  3. Enhancement of the field of first flux penetration due to Andreev bound states in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}

    Beek, C.J. van der, E-mail: kees.vanderbeek@polytechnique.ed [Laboratoire des Solides Irradies, CNRS UMR 7642 and CEA/DSM/IRAMIS, Ecole Polytechnique, F-91128 Palaiseau Cedex (France); Boehmer, A.E.; Konczykowski, M. [Laboratoire des Solides Irradies, CNRS UMR 7642 and CEA/DSM/IRAMIS, Ecole Polytechnique, F-91128 Palaiseau Cedex (France)


    First flux penetration into single crystalline Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} is investigated using magneto-optical imaging and Hall probe array magnetometry. Below 50 K, a slight enhancement of the field of first flux penetration, H{sub p}, is found when the edge normals are oriented at 45{sup o} with respect to the principal (ab) crystal axes, rather than parallel to them. We discuss this effect in terms of a role of Andreev bound states (Iniotakis et al., 2008).

  4. Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+delta} c-axis twist Josephson junctions : a new phase-sensitive test of order parameter symmetry.

    Klemm, R. A.; Arnold, G.; Bille, A.; Rieck, C. T.; Scharnberg, K.


    Li et al. found that the critical current density J{sub c}{sup J} across atomically clean c-axis twist junctions of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} is the same as that of the constituent single crystal, J{sub c}{sup S}, independent of the twist angle {phi}{sub 0}, even at and below T{sub c}. They investigated theoretically if a d{sub x{sup 2}{minus}y{sup 2}} wave order parameter might twist by mixing in d{sub xy}-wave components, but found that such mixing cannot possibly explain the data near to T{sub c}. Combined with group theoretical arguments, they then conclude that the order parameter contains at least a substantial s-wave component, but does not contain any purported d{sub x{sup 2}{minus}y{sup 2}}-wave component, except possibly below a second, unobserved phase transition. By studying tunneling models, they further conclude that the intrinsic c-axis Josephson tunneling in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} is likely to be mostly incoherent.

  5. Nature of the high-binding-energy dip in the low-temperature photoemission spectra of Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8+. delta

    Dessau, D.S.; Shen, Z.; Wells, B.O.; King, D.M.; Spicer, W.E. (Stanford Electronics Laboratory, Stanford University, Stanford, California 94305 (United States)); Arko, A.J. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)); Lombardo, L.W.; Mitzi, D.B.; Kapitulnik, A. (Department of Applied Physics, Stanford University, Stanford, California 94305 (United States))


    At the transition to superconductivity, an anomalous high-binding-energy ({approx}{minus}90 meV) dip appears in the low-temperature photoemission spectra taken along the {Gamma}-{ital {bar M}} high-symmetry direction of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}. This paper details experiments which further characterize the energy and {bold k}-space dependence of this dip structure. The dip occurs over a wide portion of the {Gamma}-{ital {bar M}} zone diagonal (110), yet shows minimal energy dispersion. In the spectra taken along the {Gamma}-{ital X} zone edge (100), the dip is very weak or not present. We show that these results imply that the dip is not an artifact dependent on the experiment or special features of the band structure and therefore is an intrinsic feature of the superconducting state of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}. The behavior of the normal-state bands along {Gamma}-{ital {bar M}} in relation to the local-density-approximation prediction of a Bi-O-based electron pocket'' is also discussed, with our data explained most naturally if the Bi-O band remains above the Fermi level for all {bold k}.

  6. Mechanochemical synthesis and electrical conductivity of nanocrystalline delta-Bi2O3 stabilized by HfO2 and ZrO2



    Full Text Available A powder mixture of a-Bi2O3 and HfO2, in the molar ratio 2:3, was mechanochemically treated in a planetary ball mill under air, using zirconium oxide vials and balls as the milling medium. After 50 h of milling, the mechanochemical reaction led to the formation of a nanocrystalline a-Bi2O3 phase (fluorite-type solid solution Bi0.87Hf0.59Zr0.63O3.61, with a crystallite size of 20 nm. The mechanochemical reaction started at a very beginning of milling accompanied by an accumulation of ZrO2 arising from the milling tools. The samples prepared after various milling times were characterized by X-ray powder diffraction and DSC analysis. The electrical properties of the as-milled and pressed Bi0.87Hf0.59Zr0.63O3.61powder were studied using impedance spectroscopy in the temperature range from 100 to 700 °C under air. The electrical conductivity was determined to be 9.43×10-6 and 0.080 S cm-1 for the temperatures of 300 and 700 °C, respectively.

  7. Growth of superconducting Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} films by sedimentation deposition and liquid phase sintering and annealing technique

    Manahan, R.L.C. [Condensed Matter Physics Laboratory, National Institute of Physics, University of the Philippines, Llamas Science Hall, Rm. 3122, E. Quirino Street, Diliman, Quezon City 1101 (Philippines)]. E-mail:; Sarmago, R.V. [Condensed Matter Physics Laboratory, National Institute of Physics, University of the Philippines, Llamas Science Hall, Rm. 3122, E. Quirino Street, Diliman, Quezon City 1101 (Philippines)


    We report on a technique of growing highly c-axis oriented Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi-2212) thick films on MgO substrate using a combined sedimentation-deposition and liquid phase sintering and annealing process. The temperature profiles employed partial melting followed by rapid cooling to temperature below the melting point. Scanning electron micrographs show that the films have a smooth surface. No evidence of grain boundaries on the film's surface can be seen. The critical temperatures of the samples range from {approx}67 K to {approx}81 K. This method presents a quick and easy preparation for high quality epitaxial Bi-2212 films.

  8. XANES study of the valence of Pb in $(Tl_{0.5} Pb_{0.5} Sr_{2} Ca_{1-x} Y_{x} Cu_{2} O_{7-\\delta}$

    Liang, G; Wang, L V


    Near edge X-ray-absorption spectra at Pb L/sub 3/-edges have been measured for (Tl/sub 0.5/Pb/sub 0.5/)Sr/sub 2/Ca/sub 1-x/Y/sub x/Cu /sub 2/O/sub 7- delta / compound series. It is found that the intensity of the 2p to 6s transition feature decreases with the substitution of Ca/sup +2/ by Y/sup +3/. This result indicates that some electronic charges have been transferred into the Pb(Tl)-O layers by this substitution. Detailed analysis suggests that the valence value of Pb in this compound series is close to +4 and it decreases with the increase of the Y-doping level x. (8 refs).

  9. Doppler broadening measurements of positron annihilation in single crystalline Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} high T{sub c} superconductor along two different crystallographic directions

    Chakrabarti, Mahuya [Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700009 (India); Sarkar, A. [Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700009 (India); Department of Physics, Bangabasi Morning College, 19 Rajkumar Chakraborty Sarani, Kolkata 700009 (India); Chattapadhayay, S. [Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700009 (India); Sanyal, D. [Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064 (India)]. E-mail:; Chakrabarti, A. [Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064 (India)


    Doppler broadening of the electron positron annihilation {gamma}-radiation spectra of single crystalline Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} high T{sub c} superconducting sample along the two different crystallographic orientations (c-axis and a-b-plane) have been analyzed by constructing ratio-curves with the reference spectra of defect free 99.9999% pure Al and Cu, respectively. The results indicate that the momentum component (p{sub L}) of the 2p electrons of oxygen ions and the 3d electrons of the Cu ions is relatively more towards the c-axis than the a-b-plane.

  10. Growth phenomena of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} thin films deposited on (110) oriented SrTiO{sub 3} substrates

    Brecht, E.; Linker, G.; Kroener, T.; Schneider, R.; Geerk, J.; Meyer, O. [Forschungszentrum Karlsruhe GmbH Tech. und Umwelt (Germany). INFP; Traeholt, C. [National Centre for HREM, Laboratory of Materials Science, Delft University of Technology, Rotterdamseweg 137, NL-2628 AL Delft (Netherlands)


    Thin films of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} have been deposited on (110) oriented SrTiO{sub 3} substrates by inverted cylindrical magnetron sputtering. In structural studies, two competing growth orientations have been observed: domains with the c-axis oriented perpendicular to the substrate surface and inclined domains with the c-axis almost parallel to the [100]{sub S} and [010]{sub S} directions of the substrate. For both growth orientations, in-plane alignment within the (110){sub S} plane has been achieved. Domains of the different growth orientations are clearly reflected in the surface morphology of the films. (orig.)

  11. Microwave absorption study in the ferromagnetic superconductor Gd{sub 1.4}Ce{sub 0.6}RuSr{sub 2}Cu{sub 2}O{sub 10-{delta}}

    Moreno, N.O.; Campoy, J.C.P.; Granado, E.; Rettori, C. [Universidade Estadual de Campinas (Brazil). Inst. de Fisica; Pagliuso, P.G. [Los Alamos National Lab., Los Alamos, NM (United States); Cheong, S.-W. [Bell Lab., Lucent Technologies, Murray Hill, NJ (United States); Oseroff, S.B. [Dept. of Physics, SDSU, San Diego, CA (United States)


    We have performed microwave absorption (MWA) and ferromagnetic resonance measurements (FMR) in Gd{sub 1.4}Ce{sub 0.6}RuSr{sub 2}Cu{sub 2}O{sub 10-{delta}} polycrystalline samples between 300 and 8 K. Below the magnetic ordering temperature (T{sub m} {approx} 89 K) a MWA is observed due to the appearance of weak ferromagnetism (WFMWA). The intensity of the WFMWA decreases as T approaches the superconducting (SC) state at T{sub c} {approx} 45 K. For T {<=} T{sub c}, a new and much stronger MWA (SCMWA) is found. This SCMWA may be associated to Josephson intergrain and to viscose dynamic dissipation of intragrain Abrikosov vortex in the SC state. (orig.)

  12. Bond Stretching Phonon Softening And Kinks in the Angle-Resolved Photoemission Spectra of Optimally Doped Bi(2)Sr(1.6)La(0.4)Cu(2)O(6)+-Delta Superconductors

    Graf, J.; d' Astuto, M.; Jozwiak, C.; Garcia, D.R.; Saini, N.L.; Krisch, M.; Ikeuchi, K.; Baron, A.Q.R.; Eisaki, H.; Lanzara, A.


    We report the first measurement of the Cu-O bond stretching phonon dispersion in optimally doped Bi{sub 2}Sr{sub 1.6}La{sub 0.4}Cu{sub 2}O{sub 6+{delta}} using inelastic x-ray scattering. We found a softening of this phonon at q = ({approx} 0.25, 0, 0) from 76 to 60 meV, similar to the one reported in other cuprates. A comparison with angle-resolved photoemission data on the same sample revealed an excellent agreement in terms of energy and momentum between the angle-resolved photoemission nodal kink and the soft part of the bond stretching phonon. Indeed, we find that the momentum space where a 63 {+-} 5 meV kink is observed can be connected with a vector q = ({zeta}, 0, 0) with {zeta} {ge} 0.22, corresponding exactly to the soft part of the bond stretching phonon.

  13. Aerosol Observing System Greenhouse Gas (AOS GhG) Handbook

    Biraud, S. C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Reichl, K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)


    The Greenhouse Gas (GhG) Measurement system is a combination of two systems in series: (1) the Tower Gas Processing (TGP) System, an instrument rack which pulls, pressurizes, and dries air streams from an atmospheric sampling tower through a series of control and monitoring components, and (2) the Picarro model G2301 cavity ringdown spectrometer (CRDS), which measures CO2, CH4, and H2O vapor; the primary measurements of the GhG system.

  14. Development of Bulk Bi2+xSr3-yCa yCu 2O8+delta Superconductors by Partial-Melting Route for Fault Current Limiters Application

    Bojan A. Marinkovic


    Full Text Available The production of bulk Bi2+xSr3-yCa yCu 2O8+delta (Bi-2212 superconductors for fault current limiter application was developed via a partial-melting route. Aiming high Ic (critical current, which is the essential superconducting characteristic for application of this material in the construction of Fault Current Limiters (FCL, the produced blocks have predominance of Bi-2212 phase (83 wt%, which characterizes with high values of zero and onset transport critical temperature of 92K and 97.5K, respectively. A relatively low transition width, deltaT, from the superconducting to the normal state of 5.5K, revealed a good intergrain connectivity. Consequently, current measurements on the blocks of Bi-2212 show promising Ic values of 230A and 850A for direct and alternate current, respectively. It is expected that further increases in the Ic values will depend on the elimination of an observed amorphous phase and further reduction of amount and grain sizes of secondary phases, still present in the blocks obtained by the proposed partial-melting route. This may be achieved by a further optimization of the partial-melting processing parameters.

  15. Serum growth hormone (GH) profiles after nasally administered GH in normal subjects and GH deficient patients

    Møller, Jens; Laursen, Torben; Mindeholm, Linda


    Abstract OBJECTIVE: GH-deficient patients are at present treated with daily subcutaneous GH injections. Further improvements in patient compliance and effects of treatment may occur with nasal administration. We have examined the absorption of nasally administered GH in healthy subjects and in GH...

  16. La(0.4)Ba(0.6)Fe(0.8)Zn(0.2)O(3-delta) as cathode in solid oxide fuel cells for simultaneous NO reduction and electricity generation.

    Zhou, Renjie; Bu, Yunfei; Xu, Dandan; Zhong, Qin


    A perovskite-type oxide La(0.4)Ba(0.6)Fe(0.8)Zn(0.2)O(3-delta) (LBFZ) was investigated as the cathode material for simultaneous NO reduction and electricity generation in solid oxide fuel cells (SOFCs). The microstructure of LBFZ was demonstrated by X-ray diffraction and scanning electron microscopy. The results showed that a single cubic perovskite LBFZ was formed after calcined at 1100 degrees C. Meanwhile, the solid-state reaction between LBFZ and Ce(0.8)Sm(0.2)O(1.9) (SDC) at 900 degrees C was negligible. To measure the electrochemical properties, SOFC units were constructed with Sm(0.9)Sr(0.1)Cr(0.5)Fe(0.5)O3 as the anode, SDC as the electrolyte and LBFZ as the cathode. The maximum power density increased with the increasing NO concentration and temperature. The cell resistance is mainly due to the cathodic polarization resistance.

  17. Analysis of Surface Binding Sites (SBS) within GH62, GH13, and GH77

    Wilkens, Casper; Cockburn, Darrell; Andersen, Susan


    ) SBS containing proteins are migrating slower in native polyacrylamide electrophoresis gels cast with polysaccharide versus without polysaccharide. Amylolytic enzymes from GH13 and GH77 and xylanases from GH10 and GH11 are the best studied GH families with respect to SBS, presenting about half...... of the reported SBSs. In GH13 SBSs have been seen in 17 subfamilies including SBSs with highly diverse functions in the same enzyme. Circumstantial evidence is provided for an SBS in the GH77 MalQ from Escherichia coli, the bacterial orthologue of Arabidopsis DPE2 involved in starch metabolism. Furthermore...

  18. Electrical potential distribution in terahertz-emitting rectangular mesa devices of high- T c superconducting Bi2Sr2CaCu2O{}_{8+\\delta }

    Watanabe, Chiharu; Minami, Hidetoshi; Kitamura, Takeo; Saiwai, Yoshihiko; Shibano, Yuki; Katsuragawa, Takuya; Kubo, Hiroyuki; Sakamoto, Kazuki; Kashiwagi, Takanari; Klemm, Richard A.; Kadowaki, Kazuo


    Excessive Joule heating of conventional rectangular mesa devices of the high-transition-temperature {T}{{c}} superconductor Bi2Sr2CaCu2O{}8+δ leads to hot spots, in which the local temperature T({\\boldsymbol{r}})\\gt {T}{{c}}. Similar devices without hot spots are known to obey the ac-Josephson relation, emitting sub-terahertz (THz) waves at frequencies f\\propto V/N, where V is the applied dc voltage or electrostatic potential and N is the number of active junctions in the device. However, it often has been difficult to predict the emission f from the applied V for two reasons: N is generally unknown and therefore has been assumed to be a fitting parameter, and especially when hot spots are present, V could develop a spatial dependence that cannot be accurately determined using two-terminal measurements. To clarify the situation, simultaneous SiC microcrystalline photoluminescence measurements of T({\\boldsymbol{r}}), Fourier-transform infrared (FTIR) measurements of f, and both two and four-terminal measurements of the local V({\\boldsymbol{r}}) were performed. The present four-probe measurements provide strong evidence that when a constant V is measured within the device's superconducting region outside of the hot spot, the only requirement for the accuracy of the ac-Josephson relation is the ubiquitous adjustment of the fitting parameter N. The four-probe measurements demonstrate that the electric potential distribution is strongly non-uniform near to the hot spot, but is essentially uniform sufficiently far from it. As expected, the emission frequency follows the ac-Josephson relation correctly even for low bath temperatures at which the system jumps to inner IV characteristic branches with smaller N values, reconfirming the ac-Josephson effect as the primary mechanism for the sub-THz emission.

  19. BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.1}Yb{sub 0.1}O{sub 3-{delta}} electrolyte-based solid oxide fuel cells with cobalt-free PrBaFe{sub 2}O{sub 5+{delta}} layered perovskite cathode

    Ding, Hanping; Xue, Xingjian [Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208 (United States)


    A new anode-supported SOFC material system Ni-BZCYYb vertical stroke BZCYYb vertical stroke PBFO is investigated, in which a cobalt-free layered perovskite oxide, PrBaFe{sub 2}O{sub 5+{delta}} (PBFO), is synthesized and employed as a novel cathode while the synthesized BZCYYb is used as an electrolyte. The cell is fabricated by a simple dry-pressing/co-sintering process. The cell is tested and characterized under intermediate temperature range from 600 to 700 C with humified H{sub 2} ({proportional_to}3% H{sub 2}O) as fuel, ambient air as oxidant. The results show that the open-circuit potential of 1.006 V and maximal power density of 452 mW cm{sup -2} are achieved at 700 C. The polarization resistance of the electrodes is 0.18 {omega} cm{sup 2} at 700 C. Compared to BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.1}O{sub 3-{delta}}, the conductivity of co-doped barium zirconate-cerate BZCYYb is significantly improved. The ohmic resistance of single cell is 0.37 {omega} cm{sup 2} at 700 C. The results indicate that the developed Ni-BZCYYb vertical stroke BZCYYb vertical stroke PBFO cell is a promising functional material system for SOFCs. (author)

  20. Mortality and GH deficiency

    Stochholm, Kirstine; Gravholt, Claus Højbjerg; Laursen, Torben;


    OBJECTIVE: To estimate the mortality in Denmark in patients suffering from GH deficiency (GHD). DESIGN: Mortality was analyzed in 1794 GHD patients and 8014 controls matched on age and gender. All records in GHD patients were studied and additional morbidity noted. Patients were divided into chil......OBJECTIVE: To estimate the mortality in Denmark in patients suffering from GH deficiency (GHD). DESIGN: Mortality was analyzed in 1794 GHD patients and 8014 controls matched on age and gender. All records in GHD patients were studied and additional morbidity noted. Patients were divided...

  1. Cobalt-iron red-ox behavior in nanostructured La{sub 0.4}Sr{sub 0.6}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} cathodes

    Soldati, Analia L., E-mail: [CONICET-CNEA Departamento de Caracterizacion de Materiales, Centro Atomico Bariloche, Av. Bustillo 9500, S.C. de Bariloche R8402AGP, Rio Negro (Argentina); Baque, Laura, E-mail: [CONICET-CNEA Departamento de Caracterizacion de Materiales, Centro Atomico Bariloche, Av. Bustillo 9500, S.C. de Bariloche R8402AGP, Rio Negro (Argentina); Napolitano, Federico, E-mail: [CONICET-CNEA Departamento de Caracterizacion de Materiales, Centro Atomico Bariloche, Av. Bustillo 9500, S.C. de Bariloche R8402AGP, Rio Negro (Argentina); Serquis, Adriana, E-mail: [CONICET-CNEA Departamento de Caracterizacion de Materiales, Centro Atomico Bariloche, Av. Bustillo 9500, S.C. de Bariloche R8402AGP, Rio Negro (Argentina)


    Nano-sized La{sub 0.4}Sr{sub 0.6}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (LSCF) perovskite samples (prepared by a conventional acetate route and a novel acetate synthesis with HMTA additives), were tested simulating a red-ox cycle. The crystallography was studied by X-ray Powder Diffraction (XPD) and the changes in the oxidation state of the perovskite B-site were evaluated by synchrotron X-ray Absorption Near Edge Spectroscopy (XANES). After a reducing treatment, LSFC particles show the appearance of a new phase that coexists with the original one. The structural change is accompanied by a Co and Fe formal oxidation states decrease, although Fe remains always closer to 4+ and Co closer to 3+. The treatment produces a B-site valence average reduction from 3.52+ to 3.26+ and the formation of oxygen vacancies. A re-oxidation treatment under O{sub 2} rich atmosphere at 800 Degree-Sign C for 10 h shows that the change is reversible and independent of the two chemical methods used to synthesize the LSCF nano-particles. - Graphical abstract: XANES and XPD measurements in nanostructured LSCF before (black) and after (red/green) a red/ox cycle. Highlights: Black-Right-Pointing-Pointer Red-ox treatments in LSCF nano-particles cause a reversible reaction. Black-Right-Pointing-Pointer XPD analyses show that a new 'reduced' phase coexist with the oxidize one. Black-Right-Pointing-Pointer The B-site formal oxidation state decreases and the {delta} increases upon reduction. Black-Right-Pointing-Pointer Fe remains in a higher valence (closer to 4+) than Co (close to 3+). Black-Right-Pointing-Pointer The behavior seems to be independent of the synthesis method used.

  2. Morbidity and GH deficiency

    Stochholm, Kirstine; Laursen, Torben; Green, Anders;


    OBJECTIVE: To estimate morbidity in Denmark in all patients with GH deficiency (GHD). DESIGN: Morbidity was analyzed in 1794 GHD patients and 8014 controls matched on age and gender. All records in the GHD patients were studied and additional morbidity noted. Diagnoses and dates of admissions were...

  3. GH deficiency status combined with GH receptor polymorphism affects response to GH in children.

    Valsesia, Armand; Chatelain, Pierre; Stevens, Adam; Peterkova, Valentina A; Belgorosky, Alicia; Maghnie, Mohamad; Antoniazzi, Franco; Koledova, Ekaterina; Wojcik, Jerome; Farmer, Pierre; Destenaves, Benoit; Clayton, Peter


    Meta-analysis has shown a modest improvement in first-year growth response to recombinant human GH (r-hGH) for carriers of the exon 3-deleted GH receptor (GHRd3) polymorphism but with significant interstudy variability. The associations between GHRd3 and growth response to r-hGH over 3 years in relation to severity of GH deficiency (GHD) were investigated in patients from 14 countries. Treatment-naïve pre-pubertal children with GHD were enrolled from the PREDICT studies (NCT00256126 and NCT00699855), categorized by peak GH level (peak GH) during provocation test: ≤4 μg/l (severe GHD; n=45) and >4 to GH level. GH peak level (higher vs lower) and GHRd3 (fl/fl vs d3 carriers) combined status was associated with height change over 3 years (PGH had lower growth than subjects with fl/fl (median difference after 3 years -3.3 cm; -0.3 SDS). Conversely, GHRd3 carriers with higher peak GH had better growth (+2.7 cm; +0.2 SDS). Similar patterns were observed for GH-dependent biomarkers. GE profiles were significantly different between the groups, indicating that the interaction between GH status and GHRd3 carriage can be identified at a transcriptomic level. This study demonstrates that responses to r-hGH depend on the interaction between GHD severity and GHRd3 carriage.

  4. The role of ghrelin in GH secretion and GH disorders.

    Nass, Ralf; Gaylinn, Bruce D; Thorner, Michael O


    In humans, growth hormone (GH) is secreted from the anterior pituitary in a pulsatile pattern. The traditional view is that this secretory pattern is driven by two counter regulatory neurohormones, GHRH and somatostatin. Ghrelin, the natural ligand for the growth hormone (GH)-secretagogue receptor (GHS-R), is produced in the stomach. Ghrelin is the strongest GH secretagogue known to date, but the role of endogenous ghrelin in the regulation of circulating GH levels remains controversial. The following review examines the evidence suggesting that endogenous ghrelin may be a key regulator of GH peak amplitude and discusses studies of diseases with altered GH levels, where it is found that in these states GH and ghrelin levels change in a similar way.

  5. A kinetic study of the decomposition of the cubic perovskite-type oxide Ba(x)Sr(1-x)Co(0.8)Fe(0.2)O(3-delta) (BSCF) (x = 0.1 and 0.5).

    Mueller, David N; De Souza, Roger A; Weirich, Thomas E; Roehrens, Daniel; Mayer, Joachim; Martin, Manfred


    The decomposition of the cubic perovskite-type oxide Ba(x)Sr(1-x)Co(0.8)Fe(0.2)O(3-delta) (BSCF) into hexagonal and cubic perovskite-type phases has been examined by means of Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Selected Area Electron Diffraction (SAED) and X-Ray Diffraction (XRD). SEM and TEM measurements reveal that the new hexagonal phase grows predominantly at the grain boundaries of BSCF ceramics and that the cation composition of the newly formed hexagonal phase differs from that of the starting material. An orientational relationship between the hexagonal and the parent cubic phase was also observed. By means of ex situ XRD the phase fraction of the hexagonal phase was determined as a function of annealing time. A kinetic analysis of the data, based on Avrami-type kinetics, indicates that the decomposition is independent of the initial A-site composition, and the obtained reaction order supports the conclusion that the hexagonal phase grows at the grain boundaries in dense ceramic samples.

  6. Structural and electrical properties of grain boundary Josephson junctions based on Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} thin films

    Lopera, W.; Girata, D. [Antioquia Univ., Medellin (Colombia). Dept. of Fisica; Osorio, J.; Prieto, P. [Dept. de Fisica, Univ. del Valle, Cali (Colombia)


    An in situ deposition sputtering process at high pressure has been developed for preparing high quality superconducting Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} thin films on different substrates. Both microstructural and electrical properties were well characterized by TEM, AFM, RBS, X-ray diffraction, resistivity and magnetic susceptibility. The high reproducibility of the film quality facilitated a detailed study of Josephson effect in bicrystalline grain boundary junctions (GBJs). Thin films were deposited on (001) SrTiO{sub 3} bicrystals with misorientation angles of 24 and patterned by a photolithography process using Br-ethanol chemical etching. The width of the microbridges ranges from 10 to 50 {mu}m. The critical current densities across the grain boundary have been measured and compared to the critical current in the film. A modulation in the critical current was found under magnetic field and also Shapiro steps in the I-V curves under microwave irradiation have been observed indicating a Josephson behavior. Electrical properties are well described by the resistively shunted junction (RSJ) model. The I{sub c}R{sub n} product reaches values around 2.0 mV at 4.2 K. (orig.)

  7. Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} as a cathode for IT-SOFCs with a GDC interlayer

    Duan, Zaoshu; Yang, Min; Yan, Aiyu; Hou, Zifang; Dong, Yonglai; Chong, You; Cheng, Mojie; Yang, Weishen [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)


    The chemical compatibility of the Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (BSCF) with the yttria-stabilized zirconia (YSZ) electrolyte or Gd-doped ceria electrolyte (GDC), as well as that of the GDC with the YSZ electrolyte were examined. It was found that BSCF had a good compatibility with the GDC electrolyte but a poor chemical compatibility with the YSZ electrolyte. The BSCF cathode was adopted for anode-supported YSZ electrolyte cells with and without the application of a 1{mu}m thick GDC buffering layer between the cathode and the YSZ electrolyte. The interfacial reactions of the BSCF with the YSZ electrolyte surface and the GDC coated YSZ surfaces were investigated. The single cells were evaluated by using I-V curve measurements and AC impedance spectroscopy. The results depicted a great improvement in cell performance and a significant decrease in polarization resistance after adding the GDC buffer layer. The optimum firing temperature of the GDC film onto the YSZ film was around 1250{sup o}C, which led to the maximum power density of 1.56Wcm{sup -2} at 800{sup o}C using air as oxidant and hydrogen as fuel. (author)

  8. Bean-Livingston surface barriers for flux penetration in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} single crystals near the transition temperature

    Mihalache, V., E-mail: [National Institute for Materials Physics, P.O. Box MG-7, RO-077125 Bucharest-Magurele (Romania); Dede, M.; Oral, A. [Bilkent University, Department of Physics, Ankara (Turkey); Miu, L. [National Institute for Materials Physics, P.O. Box MG-7, RO-077125 Bucharest-Magurele (Romania)


    Local magnetic hysteresis loops in Bi-2212 single crystals using SHPM. An anomalous change in the slope of H{sub p}(T) close to T{sub c}. Evidences of Bean-Livingston surface barriers even in close vicinity of T{sub c}. H{sub p}(dH/dt) reflects the thermal activation over BL barriers. The first field for magnetic flux penetration H{sub p} in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi-2212) single crystals near the critical temperature T{sub c} was investigated from the local magnetic hysteresis loops registered for different magnetic field H sweeping rates by using a scanning Hall probe microscope (SHPM) with {approx}1 {mu}m effective spatial resolution. Evidences for a significant role of the surface barrier were obtained: the asymmetric shape of the magnetization loops and an anomalous change in the slope of H{sub p}(T) close to T{sub c}.




    In this paper we use London Langevin molecular dynamics simulations to investigate the vortex matter melting transition in the highly anisotropic high-temperature superconductor material Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} in the presence of low concentration of columnar defects (CDs). We reproduce with further details our previous results obtained by using Multilevel Monte Carlo simulations that showed that the melting of the nanocrystalline vortex matter occurs in two stages: a first stage melting into nanoliquid vortex matter and a second stage delocalization transition into a homogeneous liquid. Furthermore, we report on new dynamical measurements in the presence of a current that identifies clearly the irreversibility line and the second stage delocalization transition. In addition to CDs aligned along the c-axis we also simulate the case of tilted CDs which are aligned at an angle with respect to the applied magnetic field. Results for CDs tilted by 45{degree} with respect to c-axis show that the locations of the melting and delocalization transitions are not affected by the tilt when the ratio of flux lines to CDs remains constant. On the other hand we argue that some dynamical properties and in particular the position of the irreversibility line should be affected.

  10. Study of the vortex matter in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} using the Josephson plasma resonance; Etude de la matiere de vortex dans Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} a l'aide de la resonance de plasma Josephson

    Colson, S


    The Josephson plasma resonance (JPR) is a tool of choice to measure the inter-plane phase coherence in the layered superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (BSCCO). It enables us to evaluate the wandering length r{sub w}, defined as the thermal average of the relative thermal excursions of two pancake vortices belonging to the same flux line and localized in two consecutive superconducting layers. In this work, using two experimental techniques to probe the JPR (the resonant cavity perturbation technique and the bolometric method), we have measured r{sub w} in the vortex solid in pristine or heavy-ion irradiated (dose n{sub d} = 5 x 10{sup 10}{sup -2}, i.e. B{sub {phi}} n-d{phi}{sub 0} = 1 T) under-doped BSCCO single crystals. In the pristine samples, at low magnetic fields, the temperature dependence of r{sub w} and its increase with the applied field can only be accounted for by the dominant role of the line tension (due to Josephson coupling) and its renormalization due to thermal fluctuations. The latter are responsible for the softening of the line tension for the large-wave vector modes, which eventually leads to the first order phase transition between the vortex solid and the vortex liquid. The field and temperature dependence of r{sub w} in the irradiated crystals for B << B{sub {phi}}, is the same as observed in the pristine samples. This observation is a validation for a description in term of 'discrete superconductor' of the material. (author)

  11. Electronic structure of the gold/Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8 and gold/EuBa sub 2 Cu sub 3 O sub 7 minus. delta. interfaces as studied by photoemission spectroscopy

    Dessau, D.S.; Shen, Z.; Wells, B.O.; Spicer, W.E. (Stanford Electronics Laboratories, Stanford University, Stanford, California 94305 (USA)); List, R.S.; Arko, A.J.; Bartlett, R.J.; Fisk, Z.; Cheong, S. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA)); Mitzi, D.B.; Kapitulnik, A. (Department of Applied Physics, Stanford University, Stanford, California 94305 (USA)); Schirber, J.E. (Sandia National Laboratories, Sandia, New Mexico 87185 (USA))


    High-resolution photoemission has been used to probe the electronic structure of the gold/Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} and gold/EuBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} interface formed by a low-temperature (20 K) gold evaporation on cleaved high quality single crystals. We find that the metallicity of the EuBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} substrate in the near surface region ({similar to}5 A) is essentially destroyed by the gold deposition, while the near surface region of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} remains metallic. This has potentially wide ranging consequences for the applicability of the different types of superconductors in real devices.

  12. Description of two new alpha variants: Hb Canuts [alpha85(F6)Asp-->His (alpha1)] and Hb Ambroise Pare [alpha117(GH5)Phe-->Ile (alpha2)]; two new beta variants: Hb Beaujolais [beta84(EF8)Thr-->Asn] and Hb Monplaisir [beta147 (Tyr-Lys-Leu-Ala-Phe-Phe-Leu-Leu-Ser-Asn-Phe-Tyr-158-COOH)] and one new delta variant: Hb (A2)North Africa [delta59(E3)Lys-->Met].

    Joly, Philippe; Lacan, Philippe; Bererd, Martine; Garcia, Caroline; Zanella-Cleon, Isabelle; Becchi, Michel; Aubry, Martine; Couprie, Nicole; Francina, Alain


    We present here five new hemoglobin (Hb) variants which have been identified during routine Hb analysis before their genotypic characterization. Four of these result from a classical missense mutation: Hb Canuts [alpha85(F6)Asp-->His (alpha1)], Hb Ambroise Pare [alpha117(GH5)Phe-->Ile (alpha2)], Hb Beaujolais [beta84(EF8)Thr-->Asn] and HbA(2)-North Africa [delta59(E3)Lys-->Met]. The last one, Hb Monplaisir [beta147 (Tyr-Lys-Leu-Ala-Phe-Phe-Leu-Leu-Ser-Asn-Phe-Tyr-158-COOH)], results from a frameshift mutation at the stop codon of the beta-globin gene which leads to a modified C-terminal sequence in the beta-globin chain. None of these variants seem to have a particular clinical expression in the heterozygous state. The circumstances of the discovery of these five new Hb variants emphasize the fact that an association of techniques is necessary for a complete screening of Hb variants during routine Hb analysis. Globin chain separation by reversed phase liquid chromatography (RP-LC) appears to be the most relevant method.

  13. Kinetic studies and material characterization of the mixed metal oxides La(1-x)Sr(x)CrO(3) and SrCo(0.8)Fe(0.2)O(3-delta)

    Wagner, Aaron Lewis


    La0.84Sr0.16CrO3 (LSC) is a candidate for the interconnect of the solid oxide fuel cell due to its favorable material properties. The formation of this doped perovskite material from an amorphous precursor, the product of a spray roasting process, was studied using high-temperature X-ray diffraction (HT-XRD) and electron-probe micro-analysis (EPMA). The precursor was calcined in air at a low temperature of 450°C for 40h (LT) and at a high temperature of 800°C for 2.5h (HT). The LT calcined sample is a mixture of LaCrO4 and SrCrO4 while the HT calcined sample is LaCrO3 and SrCrO4. A homogeneous interconnect with a density of 95% of theoretical was formed by heating the LT calcined sample at 1440°C for 40h. Heating the HT calcined precursor at 1500°C failed to result in a homogeneous product. The rhombohedral to cubic phase transition that LSC undergoes was carefully studied using a position sensitive detector operated in fixed mode. The rhombohedral angle is plotted as a function of temperature for LSC and LaCrO3. Incorporation of Sr into LaCrO3 reduces the starting and ending temperatures of this transition by 200°C. The candidate for the methane reforming ceramic membrane reactor SrCo 0.8Fe0.2O3-delta decomposes in low pO 2 atmospheres. Nonisothermal studies were conducted with both high temperature X-ray diffraction (HT-XRD) and Thermalgravimetric analysis (TGA). HT-XRD revealed that when subjected to a N2 atmosphere (pO2 = 1 x 10-5) decomposition occurs at temperatures exceeding 325°C. An equilibrium mass fraction of 0.15 perovskite and 0.85 brownmillerite phase was the maximum decomposition for higher temperatures. When exposed to an atmosphere with pO2 = 5 x 10-3 a maximum decomposition is achieved at 650°C. It is very interesting that decomposition subsides at higher temperatures in this atmosphere. Nonisothermal TGA showed the validity of the phase diagram presented by Lee (1996). Kinetic studies were conducted using HT-XRD and TGA in an N2 (pO2 = 1 x

  14. Vitamin D across growth hormone (GH) disorders: From GH deficiency to GH excess.

    Ciresi, A; Giordano, C


    The interplay between vitamin D and the growth hormone (GH)/insulin-like growth factor (IGF)-I system is very complex and to date it is not fully understood. GH directly regulates renal 1 alpha-hydroxylase activity, although the action of GH in modulating vitamin D metabolism may also be IGF-I mediated. On the other hand, vitamin D increases circulating IGF-I and the vitamin D deficiency should be normalized before measurement of IGF-I concentrations to obtain reliable and unbiased IGF-I values. Indeed, linear growth after treatment of nutritional vitamin D deficiency seems to be mediated through activation of the GH/IGF-I axis and it suggests an important role of vitamin D as a link between the proliferating cartilage cells of the growth plate and GH/IGF-I secretion. Vitamin D levels are commonly lower in patients with GH deficiency (GHD) than in controls, with a variable prevalence of insufficiency or deficiency, and this condition may worsen the already known cardiovascular and metabolic risk of GHD, although this finding is not common to all studies. In addition, data on the impact of GH treatment on vitamin D levels in GHD patients are quite conflicting. Conversely, in active acromegaly, a condition characterized by a chronic GH excess, both increased and decreased vitamin D levels have been highlighted, and the interplay between vitamin D and the GH/IGF-I axis becomes even more complicated when we consider the acromegaly treatment, both medical and surgical. The current review summarizes the available data on vitamin D in the main disorders of the GH/IGF-I axis, providing an overview of the current state of the art.

  15. GH Travel & Mission Support System

    US Agency for International Development — HTRAMS is a travel data collection system for GH that collects information on both the basic details of an employee's trips (destination, length, purpose, etc.) and...

  16. Hepatoprotective effect of 2'-O-galloylhyperin against oxidative stress-induced liver damage through induction of Nrf2/ARE-mediated antioxidant pathway.

    Wang, Peng; Gao, Yi-Meng; Sun, Xing; Guo, Na; Li, Ji; Wang, Wei; Yao, Li-Ping; Fu, Yu-Jie


    2'-O-galloylhyperin (2'-O-GH), an active compound isolated from Pyrola calliantha, possesses remarkable antioxidant activity. The aims of this study were to investigate the hepatoprotective effect of 2'-O-GH against oxidative stress and elucidate the underlying mechanistic signaling pathways in HepG2 cells as well as in an animal model. Results showed that 2'-O-GH significantly inhibited hydrogen peroxide (H2O2)-induced HepG2 cell death in a dose dependent manner. The mitogen-activated protein kinase activation, ROS production, mitochondrial membrane potential, intracellular calcium level and subsequent apoptotic protein activation in H2O2-stimulated HepG2 cells were remarkably inhibited by 2'-O-GH. Furthermore, 2'-O-GH stimulation resulted in a fast and dramatic activation of Akt and nuclear translocation of the NF-E2-related factor 2 (Nrf2), along with the increased expression of heme oxygenase-1 (HO-1) and levels of glutathione (GSH). Meanwhile, histopathological evaluation of the liver also revealed that 2'-O-GH effectively ameliorated CCl4-induced the hepatic damage by reducing alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. Therefore, these results suggested the hepatoprotective effect of 2'-O-GH might be correlated with its antioxidant and free radical scavenger effect.

  17. Crystallization features of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} in the Y{sub 2}BaCuO{sub 5}-BaCuO{sub 2}-CuO and Y{sub 2}Cu{sub 2}O{sub 5}-BaCuO{sub 2} systems

    Gurskii, L.I. [Belarusian State University of Informatics Science and Radioelectronics, Minsk (Belarus); Saad, A.M. [Al-Balqua Applied University, Salt (Jordan); Truhan, V.M.; Haliakevich, T.V. [Joint Institute of Solid State and Semiconductor Physics, NAS Belarus, Minsk (Belarus); Kalanda, N.A.


    Based on the data of X-ray phase and microstructure analysis, the sample composition was optimized in order to provide maximum size of the textured macrograins of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} and of the crystallites in the Y{sub 2}BaCuO{sub 5}-BaCuO{sub 2}-CuO, Y{sub 2}Cu{sub 2}O{sub 5}-BaCuO{sub 2} systems. The growth rate has been studied and the YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} growth activation energy has been calculated for the samples of Y{sub 2}BaCuO{sub 5}+3BaCuO{sub 2}+2.3CuO, Y{sub 2}BaCuO{sub 5}+3BaCuO{sub 2}+0.6CuO, and Y{sub 2}Cu{sub 2}O{sub 5}+3.5BaCuO{sub 2} compounds in the temperature range of 1240-1270 K for the case of use of the Y{sub 2}Cu{sub 2}O{sub 5} and Y{sub 2}BaCuO{sub 5} precursors with an average grain diameter of 10 {mu}m and 1 mm. A crystallization mechanism of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} in the Y{sub 2}BaCuO{sub 5}-BaCuO{sub 2}-CuO and Y{sub 2}Cu{sub 2}O{sub 5}-BaCuO{sub 2} systems in the case of different sizes of Y{sub 2}BaCuO{sub 5} and Y{sub 2}Cu{sub 2}O{sub 5} precursor grains was proposed and validated. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. A {mu}SR study of the magnetoresistive ruthenocuprates RuSr{sub 2}Nd{sub 1.8-x}Y {sub 0.2}Ce{sub x}Cu{sub 2}O{sub 10-{delta}} (x = 0.95 and 0.80)

    Mclaughlin, A C [Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE (United Kingdom); Attfield, J P [Centre for Science at Extreme Conditions and School of Chemistry, University of Edinburgh, King' s Buildings, Mayfield Road, Edinburgh EH9 3JZ (United Kingdom); Van Duijn, J [Instituto de Investigacion en EnergIas Renovables, Universidad de Castilla la Mancha, Albacete, E02006 (Spain); Hillier, A D, E-mail: [ISIS facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom)


    Zero field muon spin relaxation (ZF-{mu}SR) has been used to study the magnetic properties of the underdoped giant magnetoresistive ruthenocuprates RuSr{sub 2}Nd{sub 1.8-x}Y {sub 0.2}Ce{sub x}Cu{sub 2}O{sub 10-{delta}} (x = 0.95, 0.80). The magnetoresistance (MR) is defined so that MR = (({rho}{sub H}-{rho}{sub 0})/{rho}{sub 0}) and the giant magnetoresistive ruthenocuprates RuSr{sub 2}Nd{sub 1.8-x}Y {sub 0.2}Ce{sub x}Cu{sub 2}O{sub 10-{delta}} exhibit a large reduction in electronic resistivity upon application of a magnetic field. The ZF-{mu}SR results show a gradual loss of initial asymmetry A{sub 0} at the ruthenium spin transition temperature, T{sub Ru}. At the same time the electronic relaxation rate, {lambda}, shows a gradual increase with decreasing temperature below T{sub Ru}. These results have been interpreted as evidence for Cu spin cluster formation below T{sub Ru}. These magnetically ordered clusters grow as the temperature is decreased thus causing the initial asymmetry to decrease slowly. Giant magnetoresistance is observed over a wide temperature range in the materials studied and the magnitude increases as the temperature is reduced from T{sub Ru} to 4 K which suggests a relation between Cu spin cluster size and |-MR|. (paper)

  19. A-Site Deficient (Pr0.6Sr0.4)(1-s)Fe0.8Co0.2O3-delta Perovskites as Solid Oxide Fuel Cell Cathodes

    Kammer Hansen, Kent


    Five A-site deficient (Pr0.6Sr0.4)1−sFe0.8Co0.2O3− perovskites (s=0.01, 0.05, 0.10, 0.15, and 0.20) were synthesized using the glycine-nitrate process. The perovskites were characterized with powder X-ray diffraction (XRD), dilatometry, four-point dc conductivity measurements, and electrochemical...... resistance more than 3 times lower than the weakly A-site deficient (Pr0.6Sr0.4)0.99Fe0.8Co0.2O3− perovskite. ©2009 The Electrochemical Society...

  20. A-Site Deficient (Pr0.6Sr0.4)(1-s)Fe0.8Co0.2O3-delta Perovskites as Solid Oxide Fuel Cell Cathodes

    Kammer Hansen, Kent


    Five A-site deficient (Pr0.6Sr0.4)1−sFe0.8Co0.2O3− perovskites (s=0.01, 0.05, 0.10, 0.15, and 0.20) were synthesized using the glycine-nitrate process. The perovskites were characterized with powder X-ray diffraction (XRD), dilatometry, four-point dc conductivity measurements, and electrochemical...

  1. Thermodynamics of Cr2O3, FeCr2O4, ZnCr2O4 and CoCr2O4

    Ziemniak SE, Anovitz LM, Castelli RA, Porter WD


    High temperature heat capacity measurements were obtained for Cr{sub 2}O{sub 3}, FeCr{sub 2}O{sub 4}, ZnCr{sub 2}O{sub 4} and CoCr{sub 2}O{sub 4} using a differential scanning calorimeter. These data were combined with previously-available, overlapping heat capacity data at temperatures up to 400 K and fitted to 5-parameter Maier-Kelley C{sub p}(T) equations. Expressions for molar entropy were then derived by suitable integration of the Maier-Kelley equations in combination with recent S{sup o}(298) evaluations. Finally, a database of high temperature equilibrium measurements on the formation of these oxides was constructed and critically evaluated. Gibbs energies of Cr{sub 2}O{sub 3}, FeCr{sub 2}O{sub 4} and CoCr{sub 2}O{sub 4} were referenced by averaging the most reliable results at reference temperatures of 1100, 1400 and 1373 K, respectively, while Gibbs energies for ZnCr{sub 2}O{sub 4} were referenced to the results of Jacob [Thermochim. Acta 15 (1976) 79-87] at 1100 K. Thermodynamic extrapolations from the high temperature reference points to 298.15 K by application of the heat capacity correlations gave {Delta}{sub f}G{sup o}(298) = -1049.96, -1339.40, -1428.35 and -1326.75 kJ mol{sup -1} for Cr{sub 2}O{sub 3}, FeCr{sub 2}O{sub 4}, ZnCr{sub 2}O{sub 4} and CoCr{sub 2}O{sub 4}, respectively.

  2. GH-replacement therapy in adults

    Christiansen, J S; Jørgensen, J O; Pedersen, S A


    Growth hormone (GH) deficiency in adults, whether GH deficient since childhood or patients rendered GH deficient in adult life, is associated with psychosocial maladjustment, reduced muscle strength and reduced exercise capacity. Body composition is significantly altered with increased fat and de...

  3. Characterization and evaluation of La{sub 0.8} Sr{sub 0.2}Co{sub 0.8} Ni{sub 0.2}O{sub 3-{delta}} prepared by a polymer-assisted combustion synthesis as a cathode material for intermediate temperature solid oxide fuel cells

    Chen, Jing; Liang, Fengli; Liu, Lina; Jian, Li [School of Materials Science and Engineering, State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Jiang, San Ping [School of Mechanical and Aerospace Engineering, Nanyang Technological University (Singapore)


    A modified polymer-assisted combustion synthesis method is developed for preparation of La{sub 0.8}Sr{sub 0.2}Co{sub 0.8}Ni{sub 0.2}O{sub 3-{delta}} (LSCN) nano-sized cathode particles by using organic additives (glucose and acrylamide) and metal nitrates. The effect of the organic additives, pH value of starting solution and calcination temperature on the formation of the LSCN perovskite phase and microstructure of the powders is investigated. Chemical compatibility between the LSCN and Y{sub 2}O{sub 3} stabilized ZrO{sub 2} (YSZ) and Gd{sub 2}O{sub 3} doped CeO{sub 2} (GDC) is evaluated and electrochemical activity of LSCN cathode is evaluated. The prepared LSCN is chemically compatible with the YSZ only at temperatures below 850 C. The electrode area specific resistance (ASR) is 0.30 and 0.10 {omega} cm{sup 2} at 700 and 750 C, respectively. These results suggest that such prepared LSCN is a promising alternative cathode material for intermediate temperature SOFCs. (author)

  4. Rescue of Isolated GH Deficiency Type II (IGHD II) via Pharmacologic Modulation of GH-1 Splicing.

    Miletta, Maria Consolata; Petkovic, Vibor; Eblé, Andrée; Flück, Christa E; Mullis, Primus-E


    Isolated GH deficiency (IGHD) type II, the autosomal dominant form of GHD, is mainly caused by mutations that affect splicing of GH-1. When misspliced RNA is translated, it produces a toxic 17.5-kDa GH isoform that reduces the accumulation and secretion of wild-type-human GH (wt-hGH). Usually, isolated GHD type II patients are treated with daily injections of recombinant human GH in order to maintain normal growth. However, this type of replacement therapy does not prevent toxic effects of the 17.5-kDa GH isoform on the pituitary gland, which can eventually lead to other hormonal deficiencies. Here, we tested the possibility to restore the constitutive splicing pattern of GH-1 by using butyrate, a drug that mainly acts as histone deacetylase inhibitor. To this aim, wt-hGH and/or different hGH-splice site mutants (GH-IVS3+2, GH-IVS3+6, and GH-ISE+28) were transfected in rat pituitary cells expressing human GHRH receptor (GHRHR) (GC-GHRHR). Upon butyrate treatment, GC-GHRHR cells coexpressing wt-hGH and each of the mutants displayed increased GH transcript level, intracellular GH content, and GH secretion when compared with the corresponding untreated condition. The effect of butyrate was most likely mediated by the alternative splicing factor/splicing factor 2. Overexpression of alternative ASF/SF2 in the same experimental setting, indeed, promoted the amount of full-length transcripts thus increasing synthesis and secretion of the 22-kDa GH isoform. In conclusion, our results support the hypothesis that modulation of GH-1 splicing pattern to increase the 22-kDa GH isoform levels can be clinically beneficial and hence a crucial challenge in GHD research.

  5. GH and IGF1: Roles in Energy Metabolism of Long-Living GH Mutant Mice

    Brown-Borg, Holly M.; Bartke, Andrzej


    Of the multiple theories to explain exceptional longevity, the most robust of these has centered on the reduction of three anabolic protein hormones, growth hormone (GH), insulin-like growth factor, and insulin. GH mutant mice live 50% longer and exhibit significant differences in several aspects of energy metabolism as compared with wild-type mice. Mitochondrial metabolism is upregulated in the absence of GH, whereas in GH transgenic mice and dwarf mice treated with GH, multiple aspects of t...

  6. Isothermal Oxidation Behavior of GH3535 Superalloy at 700 ℃%GH3535合金700℃恒温氧化行为研究

    范金鑫; 陆燕玲; 李志军; 董加胜; 张继祥; 周兴泰; 怀平


    利用增重法,研究了GH3535合金在700℃/700 h下的恒温氧化行为.采用扫描电镜(SEM)、X射线衍射(XRD)、电子探针(EPMA)和同步辐射荧光(SRXRF)分析技术研究了GH3535合金高温氧化膜的氧化动力学、形貌及氧化物的组成.结果表明,GH3535合金在700℃/700 h氧化后表面氧化膜无明显剥落,氧化动力学曲线遵循立方规律,氧化膜厚度为5 um左右,无内氧化现象发生.700℃下,GH3535合金属于完全抗氧化等级.合金表面生成的氧化膜成分以NiO、Cr2O3、NiCr2O4和NiMn2O4为主.

  7. A remote but significant sequence homology between glycoside hydrolase clan GH-H and glycoside hydrolase family GH 31

    Janecek, S.; Svensson, Birte; MacGregor, E.A.


    , however, proposed for clan GH-H with GH31. A sequence alignment, based on the idea that residues equivalent in the primordial catalytic GH-H/GH31 (β/α)8-barrel may not be found in the present-day GH-H and GH31 structures at strictly equivalent positions, shows remote sequence homologies covering β3, β4, β...

  8. Pioglitazone treatment increases spontaneous growth hormone (GH) secretion and stimulated GH levels in polycystic ovary syndrome

    Glintborg, Dorte; Støving, René Klinkby; Hagen, Claus


    and improved insulin sensitivity during pioglitazone treatment may affect GH secretion. OBJECTIVE: The objective of the study was to investigate the effect of pioglitazone on GH levels in PCOS. DESIGN: Thirty insulin-resistant PCOS patients were randomized to either 16 wk pioglitazone (30 mg/d) or placebo...... treatment. Before and after intervention, levels of fasting insulin, GH, total IGF-I, free IGF-I, IGF binding protein-1, IGF-II, free fatty acids, testosterone, and SHBG were measured. Patients underwent whole-body dual x-ray absorptiometry scans, pyridostigmine-GHRH tests, and 24-h 20-min integrated blood...... sampling for measurement of GH. RESULTS: Peak GH and area under the curve for GH in pyridostigmine-GHRH tests and 24-h mean GH concentrations and pulsatile GH secretion significantly increased after pioglitazone treatment. No significant changes were observed in GH pulse frequency, pulse duration...

  9. Low-temperature preparation of La{sub 0.6}Sr{sub 0.4}Fe{sub 0.8}Co{sub 0.2}O{sub 3-{delta}} sinterable nanopowders by the polymeric organic complex solution method

    Perez-Falcon, J.M.; Moure, A.; Tartaj, J. [Electroceramics Department, Instituto de Ceramica y Vidrio (CSIC), Kelsen 5, 28049 Madrid (Spain)


    In this work, powders of La{sub 0.6}Sr{sub 0.4}Fe{sub 0.8}Co{sub 0.2}O{sub 3-{delta}} were prepared by the auto-combustion of ethylene glycol-metal nitrate polymerised gel precursor. This method (polymeric organic complex solution) allows decreasing the processing temperature and simplifies the whole procedure. A single phase material is obtained at 300 C lower than that needed by conventional solid state reaction (SSR). The reduced particle size and low agglomeration increases the reactivity of powders and therefore, the sintering temperature is also reduced in 200 C with respect to the conventional SSR method. As a consequence of that, the microstructures are controlled maintaining the grain size in an almost nanometric range. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Development of electrolyte-supported intermediate-temperature single-chamber solid oxide fuel cells using Ln{sub 0.7}Sr{sub 0.3}Fe{sub 0.8}Co{sub 0.2}O{sub 3-{delta}} (Ln = Pr, La, Gd) cathodes

    Ruiz de Larramendi, I.; Ruiz de Larramendi, J.I.; Rojo, T. [Departamento de Quimica Inorganica, Universidad del Pais Vasco, Apdo.644, 48080 Bilbao (Spain); Lamas, D.G.; Cabezas, M.D.; Walsoee de Reca, N.E. [CINSO, CONICET-CITEFA, J.B. de La Salle 4397 (B1603ALO) Villa Martelli, Pcia. de Buenos Aires (Argentina)


    Iron-cobalt-based perovskite oxides with general formula Ln{sub 0.7}Sr{sub 0.3}Fe{sub 0.8}Co{sub 0.2}O{sub 3-{delta}} (where Ln = La, Pr and Gd) have been investigated for their application as intermediate-temperature cathodes in solid oxide fuel cells (SOFCs). Powdered samples of these materials were synthesized by a novel gel combustion process and then characterized by X-ray powder diffraction (XPD) and scanning electron microscopy (SEM). XPD patterns were satisfactorily indexed with an orthorhombic GdFeO{sub 3}-type structure and, for all samples, a mean particle size of less than 1 {mu}m was estimated from the SEM data. Experimental single-chamber SOFCs using with these materials as cathodes and NiO-SDC (samaria-doped ceria) and SDC as anode and electrolyte, respectively, were evaluated at 600 C in a methane/oxygen mixtures. Peak power densities of 65.4, 48.7 and 46.2 mW cm{sup -2} were obtained for Ag vertical stroke Ln{sub 0.7}Sr{sub 0.3}Fe{sub 0.8}Co{sub 0.2}O{sub 3-{delta}} vertical stroke SDC vertical stroke NiO-SDC vertical stroke Pt cells with Ln = Pr, La and Gd, respectively. The relatively high power density obtained for the Pr compound shows that it could be an interesting material for cathode of single-chamber SOFCs. (author)

  11. Optimizing the modification method of zinc-enhanced sintering of BaZr{sub 0.4}Ce{sub 0.4}Y{sub 0.2}O{sub 3-{delta}}-based electrolytes for application in an anode-supported protonic solid oxide fuel cell

    Guo, Youmin; Ran, Ran; Shao, Zongping [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, No.5 Xin Mofan Road, Nanjing 210009 (China)


    The effects of zinc modification methods on membrane sintering, electrical conductivity of BaZr{sub 0.4}Ce{sub 0.4}Y{sub 0.2}O{sub 3-{delta}} (BZCY4) and the thermo-mechanical match of the BZCY4 electrolyte with anode were systematically investigated. Three modification methods are pursued, including the physical mixing of BZCY4 with a ZnO solid (method 1), introducing zinc during the solution stage of the sol-gel synthesis (method 2) and doping zinc into a perovskite lattice by synthesis of a new compound with a nominal composition of BaZr{sub 0.4}Ce{sub 0.4}Y{sub 0.16}Zn{sub 0.04}O{sub 3-{delta}} (method 3). Method 1 turned out to be the most effective at reducing the sintering temperature, which can mainly be attributed to a reactive sintering although ZnO doping into the BZCY4 lattice also facilitates the sintering. While all three modification methods facilitated the membrane sintering, only the electrolyte from method 3 had similar shrinkage behavior to the anode. An anode-supported thin-film BZCY4-3 electrolyte solid oxide fuel cell (SOFC) was successfully fabricated, and the fuel cell delivered an attractive performance with a peak power density of {proportional_to}307 mW cm{sup -2} at 700 C. (author)

  12. Effects of returns on composition, microstructure and mechanical properties of GH4169 superalloy

    Yong-liang Pu


    Full Text Available To recycle the returned alloy effectively, effects of returns proportion on alloy composition, microstructure and compression properties of superalloy GH4169 were studied by means of scanning electron microscopy (SEM, energy dispersive spectroscopy (EDS and thermal-mechanical simulator. The results show that returns addition has no significant effect on the main alloy elements content and the principle precipitates, but increases the volume fraction of Al2O3 inclusions, resulting in the increase of oxygen level of GH4169 alloy. Returns addition does not change the elastic and plastic deformation process at room temperature or at 1,150 °C, but high returns proportion GH4169 alloy shows improved compression strength and yield strength. The alloy with 100% returns shows a maximum compression strength 1,153.45 MPa at room temperature, while the alloy with 80% returns has a maximum value 69.3 MPa at 1,150 °C. Returns addition increases fluctuation range and reduces the stability of yield strength and compression strength of GH4169 alloy at room temperature. It is noted that the volume fraction and the size of Al2O3, and the fraction of Laves phase reach their maximum values in the GH4169 alloy with 60% returns, which exhibits maximum yield strength of 516.65 MPa at room temperature and 62.17 MPa at 1,150 °C.

  13. Crossover from paramagnetic to diamagnetic ac-susceptibility in Bi2Sr2CaCu2O{}_{8+\\delta } superconductor for {\\bf{H}}| | c {-} {\\rm{axis}}

    Pissas, M.; Tamegai, T.


    Ac-susceptibility measurements of the superconducting Bi2Sr2CaCu2O{}8+δ single crystal for {H}| | c-axis are presented. In low frequency measurements the first harmonic ac-susceptibility, {χ }1={χ }1{\\prime }-{{i}}{χ }1{\\prime\\prime }, is real and independent of the amplitude of the ac-magnetic field (linear behavior) and positive, implying that it represents the slope of the magnetization curve as the temperature changes below T c2. The positive ac-susceptibility before becoming negative, at low temperatures, forms a positive local maximum arising from the melting transition of the Abrikosov vortex lattice. For higher frequencies the response becomes diamagnetic due to the eddy currents. The signature of the discontinuous change of the magnetization, at the melting transition in higher frequency measurements, is a sharp shoulder near the complete screening. The presence of second harmonic susceptibility in the liquid regime implies nonlinear variation of the equilibrium magnetization.

  14. Negative correlation between enhanced crossover temperature and fluctuation-free critical current of the second switch in Bi2Sr2CaCu2O{}_{8+\\delta } intrinsic Josephson junction

    Nomura, Y.; Okamoto, R.; Kakeya, I.


    We have investigated the switching dynamics of the first and second switches in intrinsic Josephson junctions (IJJs) of Bi2Sr2CaCu2O{}8+δ with different maximum Josephson current density J c to reveal the doping evolution of interaction between IJJs. For the second switch, the crossover temperature between temperature-independent switching similar to quantum tunneling and thermally activated switching {T}2{nd}* is remarkably higher than that for the first switch. Moreover, {T}2{nd}* slightly decreases with increasing J c, which violates the conventional relation between the crossover temperature and the critical current density. These features can be explained not by a change in the Josephson coupling energy but by a change in the charging energy of the Josephson junction. We argue that the capacitive coupling model explains the increase in the fluctuation in the quantum regime of the second switch and the anti-correlation between {T}2{nd}* and J c. Furthermore, inductive coupling does not contribute to these peculiar phenomena in the switching dynamics of stacked IJJs.

  15. Cushing, acromegaly, GH deficiency and tendons


    Cushing’s syndrome, induced by an endogenous or exogenous cortisol excess, and acromegaly, the clinical syndrome caused by growth hormone (GH) excess in adulthood, as well as the disease induced by GH deficiency (GHD), represent perfect models for the evaluation of the effects induced by chronic exposure in vivo, respectively, to cortisol and GH/IGF-1 excess or deficiency on the complex structure of the tendons as well as on the related post-traumatic repair mechanism. Although the literature...

  16. Growth hormone (GH), brain development and neural stem cells.

    Waters, M J; Blackmore, D G


    A range of observations support a role for GH in development and function of the brain. These include altered brain structure in GH receptor null mice, and impaired cognition in GH deficient rodents and in a subgroup of GH receptor defective patients (Laron dwarfs). GH has been shown to alter neurogenesis, myelin synthesis and dendritic branching, and both the GH receptor and GH itself are expressed widely in the brain. We have found a population of neural stem cells which are activated by GH infusion, and which give rise to neurons in mice. These stem cells are activated by voluntary exercise in a GH-dependent manner. Given the findings that local synthesis of GH occurs in the hippocampus in response to a memory task, and that GH replacement improves memory and cognition in rodents and humans, these new observations warrant a reappraisal of the clinical importance of GH replacement in GH deficient states.

  17. GH activity and markers of inflammation

    Andreassen, Mikkel; Frystyk, Jan; Faber, Jens;


    The GH/IGF1 axis may modulate inflammatory processes. However, the relationship seems complicated as both pro- and anti-inflammatory effects have been demonstrated.......The GH/IGF1 axis may modulate inflammatory processes. However, the relationship seems complicated as both pro- and anti-inflammatory effects have been demonstrated....

  18. Ghrelin- and GH-induced insulin resistance

    Vestergaard, Esben Thyssen; Krag, Morten B; Poulsen, Morten M


    Supraphysiological levels of ghrelin and GH induce insulin resistance. Serum levels of retinol-binding protein-4 (RBP4) correlate inversely with insulin sensitivity in patients with type 2 diabetes. We aimed to determine whether ghrelin and GH affect RBP4 levels in human subjects....

  19. Ghrelin drives GH secretion during fasting in man

    A.F. Muller (Alex); S.W.J. Lamberts (Steven); L.J. Hofland (Leo); M. Bidlingmaier (Martin); C.J. Strasburger; E. Ghigo (Ezio); A-J. van der Lely (Aart-Jan); J.A.M.J.L. Janssen (Joseph); P.M. van Koetsveld (Peter)


    textabstractOBJECTIVES: In humans, fasting leads to elevated serum GH concentrations. Traditionally, changes in hypothalamic GH-releasing hormone and somatostatin release are considered as the main mechanisms that induce this elevated GH secretion during fasting. Ghrelin is an

  20. Intermediate-temperature electrochemical performance of polycrystalline PrBaCo{sub 2}O{sub 5}+{delta}-based cathodes on Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9} electrolytes

    Chen, D.J.; Shao, Z.P. [Nanjing Univ. of Technology, Nanjing (China). State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering


    The intermediate-temperature electrochemical performance of polycrystalline PrBaCo{sub 2}O{sub 5}+{delta}-based cathodes on Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9} electrolytes were synthesized and evaluated as cathodes of an intermediate-temperature solid oxide fuel cell. Using carious characterization techniques, the effects of firing temperature on the microstructure, phase reaction and performance were systematically studied. The grain size, porosity and particle connection of the electrode and the physical contact between the PrBaCo{sub 2}O{sub 5}+ and Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9} layers were influenced differently by the firing temperature. The area specific resistances of the various cathodes were measured by electrochemical impedance spectroscopy. The lowest area specific resistance and cathode overpotential were achieved at a firing temperature of 1000 degrees Celsius. According to the oxygen partial pressure dependence of the electrode area specific resistance, two main oxygen reduction reaction processes were proposed. The rate-determining step was transmitted from a charge-transfer process at low firing temperatures to a non-charge-transfer process at high firing temperatures. The effects of Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9} content on the performance and properties of the electrodes, including thermal expansion, direct current conductivity, oxygen desorption, area specific resistance and cathodic overpotential were also examined. It was concluded that the thermal expansion coefficient and electrical conductivity of the electrode decreased with an increase in Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9} content.

  1. Favorable Impacts of Growth Hormone (GH) Replacement Therapy on Atherogenic Risks in Japanese Children with GH Deficiency

    Kohno, Hitoshi; Tanaka, Toshiaki; Fujieda, Kenji; Chihara, Kazuo; Seino, Yoshiki; Irie, Minoru; Takano, Kazue


    Growth hormone (GH) affects body composition and atherogenic risk factors. Severe hyperlipidemia may develop in GH-deficient adults as a consequence of continuous GH deficiency. We investigated changes in lipid profiles in 158 Japanese children (103 boys and 55 girls) with GH deficiency who had been enrolled in the Pfizer International Growth Database Japan during 3 yr of GH replacement therapy to evaluate whether GH treatment has beneficial effects on atherogenic risk factors. Total choleste...

  2. Impact of growth hormone (GH deficiency and GH replacement upon thymus function in adult patients.

    Gabriel Morrhaye

    Full Text Available BACKGROUND: Despite age-related adipose involution, T cell generation in the thymus (thymopoiesis is maintained beyond puberty in adults. In rodents, growth hormone (GH, insulin-like growth factor-1 (IGF-1, and GH secretagogues reverse age-related changes in thymus cytoarchitecture and increase thymopoiesis. GH administration also enhances thymic mass and function in HIV-infected patients. Until now, thymic function has not been investigated in adult GH deficiency (AGHD. The objective of this clinical study was to evaluate thymic function in AGHD, as well as the repercussion upon thymopoiesis of GH treatment for restoration of GH/IGF-1 physiological levels. METHODOLOGY/PRINCIPAL FINDINGS: Twenty-two patients with documented AGHD were enrolled in this study. The following parameters were measured: plasma IGF-1 concentrations, signal-joint T-cell receptor excision circle (sjTREC frequency, and sj/beta TREC ratio. Analyses were performed at three time points: firstly on GH treatment at maintenance dose, secondly one month after GH withdrawal, and thirdly one month after GH resumption. After 1-month interruption of GH treatment, both plasma IGF-1 concentrations and sjTREC frequency were decreased (p<0.001. Decreases in IGF-1 and sjTREC levels were correlated (r = 0.61, p<0.01. There was also a decrease in intrathymic T cell proliferation as indicated by the reduced sj/beta TREC ratio (p<0.01. One month after reintroduction of GH treatment, IGF-1 concentration and sjTREC frequency regained a level equivalent to the one before GH withdrawal. The sj/beta TREC ratio also increased with GH resumption, but did not return to the level measured before GH withdrawal. CONCLUSIONS: In patients with AGHD under GH treatment, GH withdrawal decreases thymic T cell output, as well as intrathymic T cell proliferation. These parameters of thymus function are completely or partially restored one month after GH resumption. These data indicate that the functional

  3. Lymphocyte GH-axis hormones in immunity.

    Weigent, Douglas A


    The production and utilization of common ligands and their receptors by cells of the immune and neuroendocrine systems constitutes a biochemical information circuit between and within the immune and neuroendocrine systems. The sharing of ligands and receptors allows the immune system to serve as the sixth sense notifying the nervous system of the presence of foreign entities. Within this framework, it is also clear that immune cell functions can be altered by neuroendocrine hormones and that cells of the immune system have the ability to produce neuroendocrine hormones. This review summarizes a part of this knowledge with particular emphasis on growth hormone (GH). The past two decades have uncovered a lot of detail about the actions of GH, acting through its receptor, at the molecular and cellular level and its influence on the immune system. The production and action of immune cell-derived GH is less well developed although its important role in immunity is also slowly emerging. Here we discuss the production of GH, GH-releasing hormone (GHRH) and insulin-like growth factor-1 (IGF-1) and their cognate receptors on cells of the immune system and their influence via endocrine/autocrine/paracrine and intracrine pathways on immune function. The intracellular mechanisms of action of immune cell-derived GH are still largely unexplored, and it is anticipated that further work in this particular area will establish an important role for this source of GH in normal physiology and in pathologic situations.

  4. Stress rupture properties of GH4169 superalloy

    Xudong Lu


    Full Text Available GH4169 alloy is a nickel-based superalloy extensively used in the aircraft engine industry because of its excellent mechanical properties and good fabrication ability. The mechanical properties of the GH4169 at high temperature, rupture stress under severe condition deserves a close attention. In this paper, the creep rupture of the GH4169 alloy under constant load and different temperatures from 550 °C to 700 °C conditions is systematically evaluated and major impact factors in the stress rupture behavior are analyzed. Furthermore, an improving method for the alloy stress rupture is proposed.

  5. Effect of cation doping on the physical properties and electrochemical performance of Nd{sub 0.6}Sr{sub 0.4}Co{sub 0.8}M{sub 0.2}O{sub 3-{delta}} (M = Ti, Cr, Mn, Fe, Co, and Cu) cathodes

    Lee, K.T.; Manthiram, A. [Materials Science and Engineering Program, University of Texas at Austin, Austin, TX 78712 (United States)


    The effect of M{sup n+} cation doping on the crystal chemistry, thermal expansion coefficient (TEC), electrical conductivity, and electrochemical performance in solid oxide fuel cells (SOFC) of the Nd{sub 0.6}Sr{sub 0.4}Co{sub 0.8}M{sub 0.2}O{sub 3-{delta}} (M = Ti, Cr, Mn, Fe, Co, and Cu) cathodes has been investigated. The samples form single-phase solid solutions with an orthorhombic perovskite structure. The degree of oxygen loss at high temperatures, TEC, and electrical conductivity decrease with the substitution of M{sup n+} ions for Co{sup 3+/4+} due to an increase in the thermal stability and bond strength and a decrease in the metal-oxygen covalency. The electrocatalytic activity measured with single cell SOFC decreases with M{sup n+} doping due to a decrease in the oxygen exchange, oxygen mobility, and charge transfer reaction, resulting from a decrease in the electronic conductivity and the oxide ion vacancy concentration. (author)

  6. Performance of large-scale anode-supported solid oxide fuel cells with impregnated La{sub 0.6}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}}+Y{sub 2}O{sub 3} stabilized ZrO{sub 2} composite cathodes

    Chen, Jing; Liang, Fengli; Yan, Dong; Pu, Jian; Chi, Bo; Jian, Li [School of Materials Science and Engineering, State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Jiang, San Ping [School of Materials Science and Engineering, State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798 (Singapore)


    Anode-supported planar solid oxide fuel cells (SOFCs) with an active area of 81 cm{sup 2} (9 cm x 9 cm) and nano-structured La{sub 0.6}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} + Y{sub 2}O{sub 3} stabilized ZrO{sub 2} (LSCF + YSZ) composite cathodes are successfully fabricated by tape casting, screen printing, co-firing and solution impregnation, and tested using H{sub 2} fuel and air oxidant at various flow rates. Maximum power densities of 437 and 473 mW cm{sup -2} are achieved at 750 C by loading 0.6 and 1.3 mg cm{sup -2} of LSCF in the composite cathodes, respectively. The gas flow rates, particularly the air, have a significant effect on the cell performance. Cell performance degradation with time is also observed, which is considered to be associated with the growth and coalescence of the nanosized LSCF particles in the composite cathode. The use of the LSCF cathode in combination with YSZ electrolyte without a Gd-doped CeO{sub 2} (GDC) buffer layer is proved to be applicable in large cells, even though the thermal stability of the nanosized LSCF needs to be further improved. (author)

  7. Immobilization of Glycoside Hydrolase Families GH1, GH13, and GH70: State of the Art and Perspectives

    Natália G. Graebin


    Full Text Available Glycoside hydrolases (GH are enzymes capable to hydrolyze the glycosidic bond between two carbohydrates or even between a carbohydrate and a non-carbohydrate moiety. Because of the increasing interest for industrial applications of these enzymes, the immobilization of GH has become an important development in order to improve its activity, stability, as well as the possibility of its reuse in batch reactions and in continuous processes. In this review, we focus on the broad aspects of immobilization of enzymes from the specific GH families. A brief introduction on methods of enzyme immobilization is presented, discussing some advantages and drawbacks of this technology. We then review the state of the art of enzyme immobilization of families GH1, GH13, and GH70, with special attention on the enzymes β-glucosidase, α-amylase, cyclodextrin glycosyltransferase, and dextransucrase. In each case, the immobilization protocols are evaluated considering their positive and negative aspects. Finally, the perspectives on new immobilization methods are briefly presented.

  8. Circulating levels of GH-releasing hormone and GH during human pregnancy.

    Mazlan, M; Spence-Jones, C; Chard, T; Landon, J; McLean, C


    To study the potential role of GH-releasing hormone (GHRH) in maintaining circulating levels of GH during pregnancy, 302 maternal plasma samples were collected from non-fasted subjects at various stages of pregnancy and assayed for GHRH using a 'two-site' immunoradiometric assay. The GH and placental lactogen levels were also determined. In addition, maternal plasma samples taken during labour, amniotic fluid and cord blood were also assayed for these hormones. Maternal plasma GHRH levels were similar to non-pregnant levels throughout gestation despite fluctuations in GH values which were always higher than non-pregnant levels. There was no significant difference between GHRH levels in maternal plasma and cord blood although high GH levels were observed in the latter. These findings suggest that peripheral GHRH levels do not play an important role in maintaining circulating GH levels during pregnancy.

  9. Correlation between GH and IGF-1 during treatment for acromegaly.

    Oldfield, Edward H; Jane, John A; Thorner, Michael O; Pledger, Carrie L; Sheehan, Jason P; Vance, Mary Lee


    OBJECTIVE The relationship between growth hormone (GH) and insulin-like growth factor-1 (IGF-1) in patients with acromegaly as serial levels drop over time after treatment has not been examined previously. Knowledge of this relationship is important to correlate pretreatment levels that best predict response to treatment. To examine the correlation between GH and IGF-1 and IGF-1 z-scores over a wide range of GH levels, the authors examined serial GH and IGF-1 levels at intervals before and after surgery and radiosurgery for acromegaly. METHODS This retrospective analysis correlates 414 pairs of GH and IGF-1 values in 93 patients with acromegaly. RESULTS Absolute IGF-1 levels increase linearly with GH levels only up to a GH of 4 ng/ml, and with IGF-1 z-scores only to a GH level of 1 ng/ml. Between GH levels of 1 and 10 ng/ml, increases in IGF-1 z-scores relative to changes in GH diminish and then plateau at GH concentrations of about 10 ng/ml. From patient to patient there is a wide range of threshold GH levels beyond which IGF-1 increases are no longer linear, GH levels at which the IGF-1 response plateaus, IGF-1 levels at similar GH values after the IGF-1 response plateaus, and of IGF-1 levels at similar GH levels. CONCLUSIONS In acromegaly, although IGF-1 levels represent a combination of the integrated effects of GH secretion and GH action, the tumor produces GH, not IGF-1. Nonlinearity between GH and IGF-1 occurs at GH levels far below those previously recognized. To monitor tumor activity and tumor viability requires measurement of GH levels.

  10. Detection of Doping with rhGH

    Wu Mou-tian


    This presentation reviewed most articles recently pub lished in peer reviewed international scientific journals related to detection doping with rhGH. Four parts were in it: First part was the brief introduction about the background of do ping,special doping with rhGH. Second part summarized the development of "indirect method", markers approach. Third was focused on the development of "direct method", isoform approach. Finally, some potential alternatives have been discussed.

  11. Observational $\\Delta\

    Hernández, Antonio García; Monteiro, Mário J P F G; Suárez, Juan Carlos; Reese, Daniel R; Pascual-Granado, Javier; Garrido, Rafael


    Delta Scuti ($\\delta$ Sct) stars are intermediate-mass pulsators, whose intrinsic oscillations have been studied for decades. However, modelling their pulsations remains a real theoretical challenge, thereby even hampering the precise determination of global stellar parameters. In this work, we used space photometry observations of eclipsing binaries with a $\\delta$ Sct component to obtain reliable physical parameters and oscillation frequencies. Using that information, we derived an observational scaling relation between the stellar mean density and a frequency pattern in the oscillation spectrum. This pattern is analogous to the solar-like large separation but in the low order regime. We also show that this relation is independent of the rotation rate. These findings open the possibility of accurately characterizing this type of pulsator and validate the frequency pattern as a new observable for $\\delta$ Sct stars.

  12. Immunofunctional assay of human growth hormone (hGH) in serum: A possible consensus for quantitative hGH measurement

    Strasburger, Christian J.; Wu, Zida; Pflaum, Claus-Dieter; Dressendörfer, Regina A.


    Confirmation of the diagnosis of GH deficiency in adults and children involves provocative testing for human (h) GH. Different commercially available immunoassays yield largely discrepant results in the measurement of GH levels in human serum. These discrepancies result in doubtful relevance of cut-off levels proposed for GH provocative testing. We have developed an immunofunctional assay method that allows quantitation of only those GH forms in circulation that possess both binding sites of ...

  13. Regulation of the growth hormone (GH) receptor and GH-binding protein mRNA

    Kaji, Hidesuke; Ohashi, Shin-Ichirou; Abe, Hiromi; Chihara, Kazuo [Kobe Univ. School of Medicine, Kobe (Japan)


    In fasting rats, a transient increase in growth hormone-binding protein (GHBP) mRNA levels was observed after 1 day, in muscle, heart, and liver, but not in fat tissues. The liver GH receptor (GHR) mRNA level was significantly increased after 1 day (but not after 5 days) of bovine GH (bGH) treatment in fed rats. Both the liver GHR mRNA level and the net increment of plasma IGF-I markedly decreased after 5 days of bGH administration in fasting rats. These findings suggest that GHR and GHBP mRNAs in the liver are expressed in a different way and that the expression of GHBP mRNA is regulated differently between tissues, at least in rats. The results also suggest that refractoriness to GH in a sustained fasting state might be beneficial in preventing anabolic effects of GH. In humans, GHR mRNA in lymphocytes, from subjects with either GH-deficiency or acromegaly, could be detected by the reverse transcription-polymerase chain reaction method. In one patient with partial GH insensitivity, a heterozygous missense mutation (P561T) was identified in the cytoplasmic domain of GHR. 15 refs., 4 figs.

  14. Synthesis of ferrite grade -Fe2O3

    K S Rane; V M S Verenkar


    Iron(II) carboxylato–hydrazinates: Ferrous fumarato–hydrazinate (FFH), FeC4H2O4.2N2H4; ferrous succinato–hydrazinate (FSH), FeC4H4O4.2N2H4;ferrous maleato–hydrazinate (FEH), FeC4H2O4.2N2H4;ferrous malato–hydrazinate (FLH), FeC4H4O5.2N2H4;ferrous malonato–hydrazinate (FMH), FeC3H2O4.1.5N2H4.H2O; and ferrous tartrato–hydrazinate (FTH), FeC4H4O6.N2H4.H2O are being synthesized for the first time. These decompose (autocatalytically) in an ordinary atmosphere to mainly -Fe2O3, while the unhydrazinated iron(II) carboxylates in air yield -Fe2O3, but the controlled atmosphere of moisture requires for the oxalates to stabilize the metastable -Fe2O3. The hydrazine released during heating reacts with atmospheric oxygen liberating enormous energy, $$N_2H_4 + O_2 \\rightarrow N_2 + H_2O;\\Delta H_2O = – 621 kJ/mol,$$ which enables to oxidatively decompose the dehydrazinated complex to -Fe2O3. The reaction products N2 + H2O provide the necessary atmosphere of moisture needed for the stabilization of the metastable oxide. The synthesis, characterization and thermal decomposition (DTA/TG) of the iron(II) carboxylato–hydrazinates are discussed to explain the suitability of -Fe2O3 in the ferrite synthesis.

  15. Effect of Ca substitution on crystal structure and superconducting properties of ferromagnetic superconductor RuSr{sub 2-x}Ca{sub x}Gd{sub 1.4}Ce{sub 0.6}Cu{sub 2}O{sub 10-{delta}}

    Fallahi, S.; Mazaheri, M. [Magnet Research Laboratory (MRL), Department of Physics, Sharif University of Technology, P.O. Box 11365-9161, Tehran (Iran, Islamic Republic of); Nikseresht, N.; Ronnow, H.M. [Laboratory for Quantum Magnetism, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Akhavan, M., E-mail: [Magnet Research Laboratory (MRL), Department of Physics, Sharif University of Technology, P.O. Box 11365-9161, Tehran (Iran, Islamic Republic of)


    We have investigated the effect of Ca substitution for Sr site on structural, magnetic and superconducting properties of RuSr{sub 2-x}Ca{sub x}Gd{sub 1.4}Ce{sub 0.6}Cu{sub 2}O{sub 10-{delta}} system. In this system, the magnetic coupling of RuO{sub 2} and CuO{sub 2} plays an important role in magnetic and superconducting states. X-ray diffraction analysis shows that all samples are single phase and the lattice parameters decrease continuously by increasing Ca content. The onset superconducting transition temperature is found to decrease with Ca substitution. As Ca content increases, rotation of the RuO{sub 6} octahedron increases and Ru-O(1)-Ru angle decreases. These variations strengthen the magnetic moments in the RuO{sub 2} planes. The enhancement of weak ferromagnetic component and hole trapping by Ru magnetic moments in RuO{sub 2} planes reduces the electrical conduction, and destroys the superconducting state in the system. Analysis of the resistivity data ({rho}) based on the hoping conduction mechanism, indicates a variation of the hoping exponent (p) across the magnetic transition at T{sub m}. The hoping exponent p is not affected sharply by Ca concentration. - Highlights: Black-Right-Pointing-Pointer We examined the effect of Ca substitution for Sr on electrical and magnetic properties of Ru1222. Black-Right-Pointing-Pointer Replacement of Sr with Ca reduces the interlayer distance of CuO{sub 2} and RuO{sub 2} layers. Black-Right-Pointing-Pointer The onset superconducting transition temperature is dropped by Ca substitution. Black-Right-Pointing-Pointer We observed the variation of the hopping exponent p across magnetic transition at T{sub m}.

  16. Activities of Amphioxus GH-Like Protein in Osmoregulation: Insight into Origin of Vertebrate GH Family

    Li, Mengyang; Jiang, Chengyan


    GH is known to play an important role in both growth promotion and osmoregulation in vertebrates. We have shown that amphioxus possesses a single GH-like hormone (GHl) gene encoding a functional protein capable of promoting growth. However, if GHl can mediate osmoregulation remains open. Here, we demonstrated clearly that GHl increased not only the survival rate of amphioxus but also the muscle moisture under high salinity. Moreover, GHl induced the expression of both the ion transporter Na+-K+-ATPase (NKA) and Na+-K+-2Cl− cotransporter (NKCC) in the gill as well as the mediator of GH action IGFl in the hepatic caecum, indicating that GHl fulfills this osmoregulatory activity through the same mechanisms of vertebrate GH. These results together suggest that the osmoregulatory activities of GH had emerged in the basal chordate amphioxus. We also proposed a new model depicting the origin of pituitary hormone family in vertebrates.

  17. Activities of Amphioxus GH-Like Protein in Osmoregulation: Insight into Origin of Vertebrate GH Family

    Mengyang Li


    Full Text Available GH is known to play an important role in both growth promotion and osmoregulation in vertebrates. We have shown that amphioxus possesses a single GH-like hormone (GHl gene encoding a functional protein capable of promoting growth. However, if GHl can mediate osmoregulation remains open. Here, we demonstrated clearly that GHl increased not only the survival rate of amphioxus but also the muscle moisture under high salinity. Moreover, GHl induced the expression of both the ion transporter Na+-K+-ATPase (NKA and Na+-K+-2Cl− cotransporter (NKCC in the gill as well as the mediator of GH action IGFl in the hepatic caecum, indicating that GHl fulfills this osmoregulatory activity through the same mechanisms of vertebrate GH. These results together suggest that the osmoregulatory activities of GH had emerged in the basal chordate amphioxus. We also proposed a new model depicting the origin of pituitary hormone family in vertebrates.

  18. Growth hormone (GH)-releasing activity of chicken GH-releasing hormone (GHRH) in chickens.

    Harvey, S; Gineste, C; Gaylinn, B D


    Two peptides with sequence similarities to growth hormone releasing hormone (GHRH) have been identified by analysis of the chicken genome. One of these peptides, chicken (c) GHRH-LP (like peptide) was previously found to poorly bind to chicken pituitary membranes or to cloned and expressed chicken GHRH receptors and had little, if any, growth hormone (GH)-releasing activity in vivo or in vitro. In contrast, a second more recently discovered peptide, cGHRH, does bind to cloned and expressed cGHRH receptors and increases cAMP activity in transfected cells. The possibility that this peptide may have in vivo GH-releasing activity was therefore assessed. The intravenous (i.v.) administration of cGHRH to immature chickens, at doses of 3-100 μg/kg, significantly increased circulating GH concentrations within 10 min of injection and the plasma GH levels remained elevated for at least 30 min after the injection of maximally effective doses. The plasma GH responses to cGHRH were comparable with those induced by human (h) or porcine (p) GHRH preparations and to that induced by thyrotropin releasing hormone (TRH). In marked contrast, the i.v. injection of cGHRH-LP had no significant effect on circulating GH concentrations in immature chicks. GH release was also increased from slaughterhouse chicken pituitary glands perifused for 5 min with cGHRH at doses of 0.1 μg/ml or 1.0 μg/ml, comparable with GH responses to hGHRH1-44. In contrast, the perifusion of chicken pituitary glands with cGHRH-LP had no significant effect on GH release. In summary, these results demonstrate that cGHRH has GH-releasing activity in chickens and support the possibility that it is the endogenous ligand of the cGHRH receptor.

  19. Response to GH treatment in adult GH deficiency is predicted by gender, age, and IGF1 SDS but not by stimulated GH-peak

    Feldt-Rasmussen, Ulla; Brabant, Georg; Maiter, Dominique


    We studied whether the severity of GH deficiency (GHD) defined as i) GH-peak on stimulation tests (insulin tolerance test (ITT), arginine, and glucagon), ii) number of additional pituitary deficits, or iii) baseline IGF1 SDS could impact the response to GH treatment. We further explored whether i...

  20. Subchronic toxicity study of GH transgenic carp.

    Yong, Ling; Liu, Yu-Mei; Jia, Xu-Dong; Li, Ning; Zhang, Wen-Zhong


    A subchronic toxicity study of GH (growth hormone) transgenic carp was carried out with 60 SD rats aged 4 weeks, weight 115∼125 g. Ten male and 10 female rats were allotted into each group. Animals of the three groups (transgenic carp group (GH-TC), parental carp group (PC) and control group) were fed soy- and alfalfa-free diet (SAFD) with 10% GH transgenic carp powder, 10% parental carp powder or 10% common carp powder for 90 consecutive days, respectively. In the end of study, animals were killed by exsanguination via the carotid artery under diethyl ether anesthesia, then weights of heart, liver, kidneys, spleen, thymus, brain, ovaries and uterus/testis were measured. Pathological examination of organs was determined. Endocrine hormones of triiodothyronine (T3), thyroid hormone (T4), follicle-stimulating hormone (FSH), 17β-estradiol (E2), progesterone (P) and testosterone (T) levels were detected by specific ELISA kit. Parameters of blood routine and blood biochemical were measured. The weights of the body and organs of the rats, food intake, blood routine, blood biochemical test and serum hormones showed no significant differences among the GH transgenic carp-treated, parental carp-treated and control groups (P>0.05). Thus, it was concluded that at the dose level of this study, GH transgenic carp showed no subchronic toxicity and endocrine disruption to SD rats.

  1. 新型低Cr镍基合金GH3535高温氧化行为%Isothermal Oxidation Behavior of New Ni-Based Superalloy GH3535 with Low Cr Level

    范金鑫; 张继祥; 陆燕玲; 李志军; 周兴泰; 怀平


    采用静态增重法,研究了GH3535合金在700~ 980℃温度范围内空气中的恒温氧化行为.利用扫描电镜(SEM)、X射线衍射仪(XRD)和电子探针(EPMA)分析了GH3535合金高温氧化膜表面与截面形貌、表面氧化膜的相组成以及氧化层中元素分布情况.结果表明GH3535合金在700℃氧化后表面氧化膜无明显剥落,氧化动力学曲线遵循立方规律,氧化膜厚度4 μm左右.870和980℃时氧化物出现剥落,870℃下无内氧化现象发生.GH3535合金在3个温度下的氧化速率分别为0.064,0.073和0.200 g·(m2·h)-1,根据氧化等级评定,700和870℃时属于完全抗氧化等级;而980℃时GH3535合金转变为抗氧化等级.GH3535合金700℃时氧化膜主要组成是外层NiO和NiFe2 O4等复合氧化物,中间层是Cr2 O3,NiCr2 O4,MoO2和NiMn2O4等氧化物;870℃氧化膜分层同700℃一致,但外层NiO含量降低,内层Cr2 O3厚度增加;980℃时外层NiO已剥落掉,露出内部Cr2 O3等氧化层,并出现了Al2O3内氧化层.

  2. The robustness of diagnostic tests for GH deficiency in adults

    Andersen, Marianne


    Since the 1970s, GH treatment has been an important tool in paediatric endocrinology for the management of growth retardation. It is now accepted that adults with severe GH deficiency (GHD) demonstrate impaired physical and psychological well-being and may benefit from replacement therapy...... with recombinant human GH. There is, however, an ongoing debate on how to diagnose GHD, especially in adults. A GH response below the cut-off limit of a GH-stimulation test is required in most cases for establishing GHD in adults. No 'gold standard' GH-stimulation test exists, but some GH stimulation tests may...... be more robust to variations in patient characteristics such as age and gender, as well as to pre-test conditions like heat exposure due to a hot bath or bicycling. However, body mass index (BMI) is negatively associated with GH-responses to all available GH-stimulation tests and glucocorticoid treatment...

  3. The influence of growth hormone (GH) deficiency and GH replacement on quality of life in GH-deficient patients.

    Deijen, J B; van der Veen, E A


    The total absence of hormones such as cortisol or thyroxine causes death within weeks. Lack of estrogen or testosterone is followed by infertility and impaired sexual functioning. Relative deficiencies of almost all classical hormones have a substantial impact on quality of life (QOL). However, in contrast to virtually all aspects of metabolism, QOL is difficult to measure. Only recently have tests been developed to assess general QOL, whereas specific tests address those aspects of QOL affected only in specific situations or disease states. For example, in rheumatoid arthritis and other chronic disabling diseases, the use of measures of QOL to assess treatment modalities is almost routine. In diseases with overt metabolic disturbances attention is generally focused on changes in metabolic parameters and the issue of QOL is neglected. Although very few practising endocrinologists will not support the idea that they specialize in improving QOL, its assessment in patients with endocrinological disorders began only recently--in patients with growth hormone (GH) deficiency only 10 years ago. It became apparent that GH deficiency in adult life is unmistakably followed by changes in parameters that determine QOL. In adults with childhood-onset GH deficiency, the unemployment rate is higher and the marriage rate lower than in the general population. Another symbol of success in life, the possession of a driver's licence, is less frequently attained by these patients. Most patients with adult-onset GH deficiency score unfavourably in questionnaires such as the Nottingham Health Profile. GH substitution is now available on a scale large enough to enable studies to be made of the effects on QOL in adults. The first studies were reported in 1989. However, only in the last few years have studies appeared in which sufficient number of patients and sufficient length of treatment were reported to allow a more objective judgement of the effectiveness of GH substitution. Although

  4. Growth hormone and cancer: GH production and action in glioma?

    Lea, Robert W; Dawson, Timothy; Martinez-Moreno, Carlos G; El-Abry, Nasra; Harvey, Steve


    The hypersecretion of pituitary growth hormone (GH) is associated with an increased risk of cancer, while reducing pituitary GH signaling reduces this risk. Roles for pituitary GH in cancer are therefore well established. The expression of the GH gene is, however, not confined to the pituitary gland and it is now known to occur in many extrapituitary tissues, in which it has local autocrine or paracrine actions, rather than endocrine function. It is, for instance, expressed in cancers of the prostate, lung, skin, endometrium and colon. The oncogenicity of autocrine GH may also be greater than that induced by endocrine or exogenous GH, as higher concentrations of GHR antagonists are required to inhibit its actions. This may reflect the fact that autocrine GH is thought to act at intracellular receptors directly after synthesis, in compartments not readily accessible to endocrine (or exogenous) GH. The roles and actions of extrapituitary GH in cancer may therefore differ from those of pituitary GH. The possibility that GH may be expressed and act in glioma tumors was therefore examined by immunohistochemistry. These results demonstrate, for the first time, the presence of abundant GH- and GH receptor (GHR-) immunoreactivity in glioma, in which they were co-localized in cytoplasmic but not nuclear compartments. These results demonstrate that glioma differs from most cancers in lacking nuclear GHRs, but GH is nevertheless likely to have autocrine or paracrine actions in the induction and progression of glioma.

  5. Graviton Propagators on Fuzzy G/H

    Kitazawa, Y; Kitazawa, Yoshihisa; Nagaoka, Satoshi


    We describe closed string modes by open Wilson lines in noncommutative (NC) gauge theories on compact fuzzy G/H in IIB matrix model. In this construction the world sheet cut-off is related to the spacetime cut-off since the string bit of the symmetric traced Wilson line carries the minimum momentum on G/H. We show that the two point correlation functions of graviton type Wilson lines in 4 dimensional NC gauge theories behave as 1/(momentum)^2. This result suggests that graviton is localized on D3-brane, so we can naturally interpret D3-branes as our universe. Our result is not limited to D3-brane system, and we generalize our analysis to other dimensions and even to any topology of D-brane worldvolume within fuzzy G/H.

  6. GH/STAT5 signaling during the growth period in livers of mice overexpressing GH.

    Martinez, Carolina S; Piazza, Verónica G; Díaz, María E; Boparai, Ravneet K; Arum, Oge; Ramírez, María C; González, Lorena; Becú-Villalobos, Damasia; Bartke, Andrzej; Turyn, Daniel; Miquet, Johanna G; Sotelo, Ana I


    GH/STAT5 signaling is desensitized in the liver in adult transgenic mice overexpressing GH; however, these animals present greater body size. To assess whether the STAT5 pathway is active during the growth period in the liver in these animals, and how signaling modulators participate in this process, growing transgenic mice and normal siblings were evaluated. STAT5 does not respond to an acute GH-stimulus, but displays higher basal phosphorylation in the livers of growing GH-overexpressing mice. GH receptor and the positive modulators glucocorticoid receptor and HNF1 display greater abundance in transgenic animals, supporting the activity of STAT5. The negative modulators cytokine-induced suppressor and PTP1B are increased in GH-overexpressing mice. The suppressors SOCS2 and SOCS3 exhibit higher mRNA levels in transgenic mice but lower protein content, indicating that they are being actively degraded. Therefore, STAT5 signaling is increased in the liver in GH-transgenic mice during the growth period, with a balance between positive and negative effectors resulting in accelerated but controlled growth.

  7. Delta robot

    Herder, J.L.; Van der Wijk, V.


    The invention relates to a delta robot comprising a stationary base (2) and a movable platform (3) that is connected to the base with three chains of links (4,5,6), and comprising a balancing system incorporating at least one pantograph (7) for balancing the robot's center of mass, wherein the at le

  8. Delta robot

    Herder, J.L.; Van der Wijk, V.


    The invention relates to a delta robot comprising a stationary base (2) and a movable platform (3) that is connected to the base with three chains of links (4,5,6), and comprising a balancing system incorporating at least one pantograph (7) for balancing the robot's center of mass, wherein the at le

  9. Isotopologue fractionation during N(2)O production by fungal denitrification.

    Sutka, Robin L; Adams, Gerard C; Ostrom, Nathaniel E; Ostrom, Peggy H


    Identifying the importance of fungi to nitrous oxide (N2O) production requires a non-intrusive method for differentiating between fungal and bacterial N2O production such as natural abundance stable isotopes. We compare the isotopologue composition of N2O produced during nitrite reduction by the fungal denitrifiers Fusarium oxysporum and Cylindrocarpon tonkinense with published data for N2O production during bacterial nitrification and denitrification. The fractionation factors for bulk nitrogen isotope values for fungal denitrification were in the range -74.7 to -6.6 per thousand. There was an inverse relationship between the absolute value of the fractionation factors and the reaction rate constant. We interpret this in terms of variation in the relative importance of the rate constants for diffusion and enzymatic reduction in controlling the net isotope effect for N2O production during fungal denitrification. Over the course of nitrite reduction, the delta(18)O values for N2O remained constant and did not exhibit a relationship with the concentration characteristic of an isotope effect. This probably reflects isotopic exchange with water. Similar to the delta(18)O data, the site preference (SP; the difference in delta(15)N between the central and outer N atoms in N2O) was unrelated to concentration during nitrite reduction and, therefore, has the potential to act as a conservative tracer of production from fungal denitrification. The SP values of N2O produced by F. oxysporum and C. tonkinense were 37.1 +/- 2.5 per thousand and 36.9 +/- 2.8 per thousand, respectively. These SP values are similar to those obtained in pure culture studies of bacterial nitrification but quite distinct from SP values for bacterial denitrification. The large magnitude of the bulk nitrogen isotope fractionation and the delta(18)O values associated with fungal denitrification are distinct from bacterial production pathways; thus multiple isotopologue data holds much promise for

  10. Growth hormone (GH) and GH-releasing hormone (GHRH): Co-localization and action in the chicken testis.

    Martínez-Moreno, Carlos G; López-Marín, Luz M; Carranza, Martha; Giterman, Daniel; Harvey, Steve; Arámburo, Carlos; Luna, Maricela


    Growth hormone (GH) gene expression is not confined to the pituitary gland and occurs in many extrapituitary tissues, including the chicken testis. The regulation and function of GH in extrapituitary tissues is, however, largely unknown. The possibility that chicken testicular GH might be regulated by GH-releasing hormone (GHRH), as in the avian pituitary gland, was investigated in the present study. GHRH co-localized with GH in the germinal epithelium and in interstitial zones within the chicken testes, particularly in the spermatogonia and spermatocytes. In testicular cell cultures, exogenous human GHRH1-44 induced (at 1, 10 and 100nM) a dose-related increase in GH release. Western blot analysis showed a heterogeneous pattern in the GH moieties released during GHRH stimulation. 26kDa monomer GH was the most abundant moiety under basal conditions, but 15 and 17kDa isoforms were more abundant after GHRH stimulation. GHRH treatment also increased the abundance of PCNA (proliferating cell nuclear antigen) immunoreactivity in the testes. This may have been GH-mediated, since exogenous GH similarly increased the incorporation of ((3)H)-thymidine into cultured testicular cells and increased their metabolic activity, as determined by increased MTT reduction. Furthermore, GH and GHRH immunoneutralization blocked GHRH-stimulated proliferative activity. In summary, these results indicate that GHRH stimulates testicular GH secretion in an autocrine or paracrine manner. Data also demonstrate proliferative actions of GHRH on testicular cell number and suggest that this action is mediated by local GH production.

  11. Morbidity and GH deficiency: a nationwide study

    Stochholm, K.; Laursen, T.; Green, A.;


    Objective: To estimate morbidity in Denmark in all patients with GH deficiency (GHD). Design: Morbidity was analyzed in 1794 GHD patients and 8014 controls matched on age and gender. All records in the GHD patients were studied and additional morbidity noted. Diagnoses and dates of admissions were...

  12. Evaluation of growth hormone (GH) action in mice: discovery of GH receptor antagonists and clinical indications.

    Kopchick, John J; List, Edward O; Kelder, Bruce; Gosney, Elahu S; Berryman, Darlene E


    The discovery of a growth hormone receptor antagonist (GHA) was initially established via expression of mutated GH genes in transgenic mice. Following this discovery, development of the compound resulted in a drug termed pegvisomant, which has been approved for use in patients with acromegaly. Pegvisomant treatment in a dose dependent manner results in normalization of IGF-1 levels in most patients. Thus, it is a very efficacious and safe drug. Since the GH/IGF-1 axis has been implicated in the progression of several types of cancers, many have suggested the use of pegvisomant as an anti-cancer therapeutic. In this manuscript, we will review the use of mouse strains that possess elevated or depressed levels of GH action for unraveling many of GH actions. Additionally, we will describe experiments in which the GHA was discovered, review results of pegvisomant's preclinical and clinical trials, and provide data suggesting pegvisomant's therapeutic value in selected types of cancer.

  13. Lateral shifts of spin electron beams in antiparallel double {delta}-magnetic-barrier nanostructure

    Kong Yonghong [Department of Electronic Engineering, Hunan University Science and Engineering, Hunan 425100 (China); Lu Maowang, E-mail: [Department of Electronic Engineering, Hunan University Science and Engineering, Hunan 425100 (China); Chen Saiyan; Zhang Guilian [Department of Electronic Engineering, Hunan University Science and Engineering, Hunan 425100 (China)


    We investigate the Goos-Haenchen (GH) effect of spin electron beams in a magnetic-barrier (MB) nanostructure consisting of antiparallel double {delta}-MBs, which can be experimentally realized by depositing two ferromagnetic (FM) stripes on top and bottom of the semiconductor heterostructure. GH shifts for spin electron beams across this type of MB nanostructures, is derived exactly, with the help of the stationary phase method. It is shown that GH shifts depend strongly on the spin directions for double {delta}-MBs with unidentical magnetic strengths, giving rise to a considerable spin polarization effect. It also is shown that spin polarization of GH shifts is closely relative to the separation and magnetic-strength difference of two {delta}-MBs. These interesting properties may provide an alternative scheme to spin-polarize electrons into the semiconductor, and the devices can serve as tunable spin beam splitters. - Highlights: Black-Right-Pointing-Pointer Spin Goos-Haenchen effect of electron beams through a kind of MB nanostructures. Black-Right-Pointing-Pointer GH shift depends greatly on electron-spins, which is used to spin polarize electrons in semiconductor. Black-Right-Pointing-Pointer Spin polarization in GH shift is tunable. Black-Right-Pointing-Pointer A tunable spin beam splitter is achieved.

  14. Overall and cause-specific mortality in GH-deficient adults on GH replacement

    Gaillard, Rolf C; Mattsson, Anders F; Akerblad, Ann-Charlotte


    Hypopituitarism is associated with an increased mortality rate but the reasons underlying this have not been fully elucidated. The purpose of this study was to evaluate mortality and associated factors within a large GH-replaced population of hypopituitary patients.......Hypopituitarism is associated with an increased mortality rate but the reasons underlying this have not been fully elucidated. The purpose of this study was to evaluate mortality and associated factors within a large GH-replaced population of hypopituitary patients....

  15. Metabolomics: a tool for the diagnosis of GH deficiency and for monitoring GH replacement?

    Höybye, Charlotte; Wahlström, Erik; Tollet-Egnell, Petra; Norstedt, Gunnar


    The diagnostic value of insulin-like growth factor 1 (IGF1) for GH deficiency (GHD) in adults is not optimal. Molecular profiling could be used for biomarker discovery. The aim of this pilot study was to compare the serum metabolome between GHD patients and healthy controls, and identification of potential markers for diagnosis and/or for individual GH dosing. A total of ten patients with GHD, median age of 55 years and BMI of 27 kg/m(2), were compared with ten healthy age- and gender-matched controls. The serum metabolic profiles were generated using gas chromatography-coupled mass spectroscopy on fasting samples taken in the morning from the controls and at baseline and during 6 months of GH replacement in the patients with GHD. The difference in low-molecular weight compounds (LMC) distinguished the healthy controls from GHD patients. Among 285 measured metabolites, 13 were identified as being most important in differentiating GHD patients from controls. Of these, 11 could not be structurally annotated but many were classified as lipids. The difference in the LMC pattern persisted despite normalisation of IGF1 following GH replacement. GH replacement increased the levels of specific fatty acid compounds and decreased the levels of certain amino acids. No metabolite changed in response to GH treatment, to the same extent as IGF1. The measurement of 285 metabolites resulted in a unique pattern in GHD, but changes in the metabolite patterns during GH treatment were limited. The utility of metabolomics to find new markers in GHD and GH replacement remains to be further elucidated.

  16. Ghrelin drives GH secretion during fasting in man

    A.F. Muller (Alex); S.W.J. Lamberts (Steven); L.J. Hofland (Leo); M. Bidlingmaier (Martin); C.J. Strasburger; E. Ghigo (Ezio); A-J. van der Lely (Aart-Jan); J.A.M.J.L. Janssen (Joseph); P.M. van Koetsveld (Peter)


    textabstractOBJECTIVES: In humans, fasting leads to elevated serum GH concentrations. Traditionally, changes in hypothalamic GH-releasing hormone and somatostatin release are considered as the main mechanisms that induce this elevated GH secretion during fasting. Ghrelin is an endo

  17. The GH/IGF axis in the mouse kidney

    V. Cingel-Ristic


    textabstractGrowth hormone (GH) is a protein hormone synthesized and secreted by somatotroph cells within the anterior pituitary predominantly under regulation of hypothalamic peptides, GH releasing hormone (GHRH) and somatostatin (SS) (1-3) (Figure 1). Further, production of GH is modulated by vari

  18. Continuous infusion versus daily injections of growth hormone (GH) for 4 weeks in GH-deficient patients

    Laursen, Torben; Jørgensen, Jens Otto Lunde; Jakobsen, Grethe;


    effects with constant and pulsatile GH delivery. This study was carried out to compare the metabolic effects of longer term continuous infusion vs. daily injections of GH. Thirteen GH-deficient patients were studied in a cross-over design. The patients were randomized to receive GH as a continuous sc...... infusion by means of a portable pump for 1 month and as daily sc injections (at 1900 h) for another month. An average daily GH dosage (+/- SEM) of 3.15 +/- 0.27 IU was administered during both periods. Steady state 24-h profiles of GH, IGF-I, IGF-binding proteins (IGFBPs), insulin, glucose, lipid.......35 (infusion); P infusion induced higher nighttime than daytime GH levels (P = 0.01), indicating a diurnal variation in the absorption or clearance of GH. Serum IGF-I levels (micrograms per L) were slightly higher (P infusion [312...

  19. Diagnosis of growth hormone (GH deficiency: comparison of pituitary stalk interruption syndrome and transient GH deficiency

    Brauner Raja


    Full Text Available Abstract Background Most patients with childhood non-organic growth hormone (GH deficiency (GHD produce a normal GH peak as young adults. Our objectives were to better define this transient GHD and evaluate the factors influencing the growth response of patients with pituitary stalk interruption syndrome (PSIS. Methods We studied 72 prepubertal patients with a GH peak Results At diagnosis, 64% of Group 1 and one Group 2 were During the first year of GH treatment, the growth rate was ≥ 2 SDS in 81% Group 1 and 37% Group 2 patients. In Group 1, it was negatively correlated with the GH peak before treatment (P The height gain SDSs between diagnosis and adult height were 1.7 ± 1.2 in Group 1 (n = 30 and 1.08 ± 0.8 in Group 2 (n = 12, P = 0.05. Conclusion The factors of the growth response to GH treatment should be analysed separately for each population: with and without PSIS or other markers.

  20. Growth hormone (GH) and atherosclerosis: changes in morphology and function of major arteries during GH treatment.

    Pfeifer, M; Verhovec, R; Zizek, B


    Patients with hypopituitarism have increased carotid artery intima-media thickness and reduced arterial distensibility. The effect of 2 years of growth hormone (GH) replacement therapy on these parameters was studied in 11 GH-deficient men (age range, 24-49 years) with hypopituitarism and compared with 12 healthy, age-matched men with no evidence of pituitary or vascular disease. Before treatment the intima-media of the common carotid arteries and the carotid bifurcations were significantly thicker in patients (P < 0.001) than in the control group. Treatment with GH normalized the intima-media thickness of the common carotid artery within 6 months and of the carotid bifurcation within 3 months. The changes in intima-media thickness of the carotid artery were negatively correlated with changes in serum levels of insulin-like growth factor I during treatment. There was a significant improvement in flow-mediated, endothelium-dependent dilation of the brachial artery at 3 months, which was sustained at 6, 18 and 24 months of GH treatment (P < 0.05). Thus, GH replacement therapy in GH-deficient men reverses early morphological and functional atherosclerotic changes in major arteries, and may reduce rates of vascular morbidity and mortality.

  1. GH receptor signaling in skeletal muscle and adipose tissue in human subjects following exposure to an intravenous GH bolus

    Jørgensen, Jens O L; Jessen, Niels; Pedersen, Steen Bønløkke


    Growth hormone (GH) regulates muscle and fat metabolism, which impacts on body composition and insulin sensitivity, but the underlying GH signaling pathways have not been studied in vivo in humans. We investigated GH signaling in biopsies from muscle and abdominal fat obtained 30 (n = 3) or 60 (n...... in vivo model may be used to study the mechanisms subserving the actions of GH on substrate metabolism and insulin sensitivity in muscle and fat....

  2. Insulin and GH Signaling in Human Skeletal Muscle In Vivo following Exogenous GH Exposure: Impact of an Oral Glucose Load

    Thomas Krusenstjerna-Hafstrøm; Michael Madsen; Vendelbo, Mikkel H.; Pedersen, Steen B.; Christiansen, Jens S.; Niels Møller; Niels Jessen; Jørgensen, Jens O.L.


    INTRODUCTION: GH induces acute insulin resistance in skeletal muscle in vivo, which in rodent models has been attributed to crosstalk between GH and insulin signaling pathways. Our objective was to characterize time course changes in signaling pathways for GH and insulin in human skeletal muscle in vivo following GH exposure in the presence and absence of an oral glucose load. METHODS: Eight young men were studied in a single-blinded randomized crossover design on 3 occasions: 1) after an int...

  3. GhMPK16, a novel stress-responsive group D MAPK gene from cotton, is involved in disease resistance and drought sensitivity

    Wu Changai


    Full Text Available Abstract Background Mitogen-activated protein kinase (MAPK cascades play pivotal roles in mediating biotic and abiotic stress responses. In plants, MAPKs are classified into four major groups (A-D according to their sequence homology and conserved phosphorylation motifs. Members of group A and B have been extensively characterized, but little information on the group D MAPKs has been reported. Results In this study, we isolated and characterised GhMPK16, the first group D MAPK gene found in cotton. Southern blot analysis suggests GhMPK16 is single copy in the cotton genome, and RNA blot analysis indicates that GhMPK16 transcripts accumulate following pathogen infection and treatment with multiple defense-related signal molecules. The analysis of the promoter region of GhMPK16 revealed a group of putative cis-acting elements related to stress responses. Subcellular localization analysis suggests that GhMPK16 acts in the nucleus. Transgenic Arabidopsis overexpressing GhMPK16 displayed significant resistance to fungi (Colletotrichum nicotianae and Alternaria alternata and bacteria (Pseudomonas solanacearum pathogen, and the transcripts of pathogen-related (PR genes were more rapidly and strongly induced in the transgenic plants. Furthermore, transgenic Arabidopsis showed reduced drought tolerance and rapid H2O2 accumulation. Conclusion These results suggest that GhMPK16 might be involved in multiple signal transduction pathways, including biotic and abiotic stress signaling pathways.

  4. Long-term effects of growth hormone (GH) replacement in men with childhood-onset GH deficiency

    Ter Maaten, JC; De Boer, H; Kamp, O; Stuurman, L; Van der Veen, EA


    Short term GH replacement therapy has been shown to improve body composition and exercise capacity. It is not yet known whether GH replacement remains beneficial over the long term. We assessed the effects of long term GH replacement on body composition, bone mineral density, and cardiac function. T

  5. GH safety workshop position paper: A critical appraisal of recombinant human GH therapy in children and adults

    Recombinant human Growth Hormone (rhGH) has been in use for 30 years, and over that time its safety and efficacy in children and adults has been subject to considerable scrutiny. In 2001, a statement from the GH Research Society (GRS) concluded that 'for approved indications, GH is safe'; however, t...

  6. Growth hormone (GH-releasing hormone and GH secretagogues in normal aging: Fountain of Youth or Pool of Tantalus?

    Elizabeth C Hersch


    Full Text Available Elizabeth C Hersch, George R MerriamVA Puget Sound Health Care System and University of Washington School of Medicine, Tacoma and Seattle, Washington USAAbstract: Although growth hormone (GH is primarily associated with linear growth in childhood, it continues to have important metabolic functions in adult life. Adult GH deficiency (AGHD is a distinct clinical entity, and GH replacement in AGHD can improve body composition, strength, aerobic capacity, and mood, and may reduce vascular disease risk. While there are some hormone-related side effects, the balance of benefits and risks is generally favorable, and several countries have approved GH for clinical use in AGHD. GH secretion declines progressively and markedly with aging, and many age-related changes resemble those of partial AGHD. This suggests that replacing GH, or stimulating GH with GH-releasing hormone or a GH secretagogue could confer benefits in normal aging similar to those observed in AGHD – in particular, could reduce the loss of muscle mass, strength, and exercise capacity leading to frailty, thereby prolonging the ability to live independently. However, while most GH studies have shown body composition effects similar to those in AGHD, functional changes have been much less inconsistent, and older adults are more sensitive to GH side effects. Preliminary reports of improved cognition are encouraging, but the overall balance of benefits and risks of GH supplementation in normal aging remains uncertain.Keywords: growth hormone, growth hormone-releasing hormone, growth hormone secretagogues, aging, sarcopenia, frailty

  7. Optimization of a GO2/GH2 Impinging Injector Element

    Tucker, P. Kevin; Shyy, Wei; Vaidyanathan, Rajkumar


    An injector optimization methodology, method i, is used to investigate optimal design points for a gaseous oxygen/gaseous hydrogen (GO2/GH2) impinging injector element. The unlike impinging element, a fuel-oxidizer- fuel (F-O-F) triplet, is optimized in terms of design variables such as fuel pressure drop, (Delta)P(sub f), oxidizer pressure drop, (Delta)P(sub o), combustor length, L(sub comb), and impingement half-angle, alpha, for a given mixture ratio and chamber pressure. Dependent variables such as energy release efficiency, ERE, wall heat flux, Q(sub w), injector heat flux, Q(sub inj), relative combustor weight, W(sub rel), and relative injector cost, C(sub rel), are calculated and then correlated with the design variables. An empirical design methodology is used to generate these responses for 163 combinations of input variables. Method i is then used to generate response surfaces for each dependent variable. Desirability functions based on dependent variable constraints are created and used to facilitate development of composite response surfaces representing some, or all, of the five dependent variables in terms of the input variables. Three examples illustrating the utility and flexibility of method i are discussed in detail. First, joint response surfaces are constructed by sequentially adding dependent variables. Optimum designs are identified after addition of each variable and the effect each variable has on the design is shown. This stepwise demonstration also highlights the importance of including variables such as weight and cost early in the design process. Secondly, using the composite response surface which includes all five dependent variables, unequal weights are assigned to emphasize certain variables relative to others. Here, method i is used to enable objective trade studies on design issues such as component life and thrust to weight ratio. Finally, specific variable weights are further increased to illustrate the high marginal cost of

  8. The robustness of diagnostic tests for GH deficiency in adults.

    Andersen, Marianne


    Since the 1970s, GH treatment has been an important tool in paediatric endocrinology for the management of growth retardation. It is now accepted that adults with severe GH deficiency (GHD) demonstrate impaired physical and psychological well-being and may benefit from replacement therapy with recombinant human GH. There is, however, an ongoing debate on how to diagnose GHD, especially in adults. A GH response below the cut-off limit of a GH-stimulation test is required in most cases for establishing GHD in adults. No 'gold standard' GH-stimulation test exists, but some GH stimulation tests may be more robust to variations in patient characteristics such as age and gender, as well as to pre-test conditions like heat exposure due to a hot bath or bicycling. However, body mass index (BMI) is negatively associated with GH-responses to all available GH-stimulation tests and glucocorticoid treatment, including conventional substitution therapy, influences the GH-responses. Recently, the role of IGF-I measurements in the clinical decision making has been discussed. The aim of this review is to discuss the available GH-stimulation tests. In this author's opinion, tests which include growth-hormone-releasing hormone (GHRH) tend to be more potent and robust, especially the GHRH+arginine test which has been proven to be of clinical use. In contrast, the insulin tolerance test (ITT) and the glucagon test appear to have too many drawbacks.

  9. Insulin and GH signaling in human skeletal muscle in vivo following exogenous GH exposure: impact of an oral glucose load.

    Thomas Krusenstjerna-Hafstrøm

    Full Text Available INTRODUCTION: GH induces acute insulin resistance in skeletal muscle in vivo, which in rodent models has been attributed to crosstalk between GH and insulin signaling pathways. Our objective was to characterize time course changes in signaling pathways for GH and insulin in human skeletal muscle in vivo following GH exposure in the presence and absence of an oral glucose load. METHODS: Eight young men were studied in a single-blinded randomized crossover design on 3 occasions: 1 after an intravenous GH bolus 2 after an intravenous GH bolus plus an oral glucose load (OGTT, and 3 after intravenous saline plus OGTT. Muscle biopsies were taken at t = 0, 30, 60, and 120. Blood was sampled at frequent intervals for assessment of GH, insulin, glucose, and free fatty acids (FFA. RESULTS: GH increased AUC(glucose after an OGTT (p<0.05 without significant changes in serum insulin levels. GH induced phosphorylation of STAT5 independently of the OGTT. Conversely, the OGTT induced acute phosphorylation of the insulin signaling proteins Akt (ser(473 and thr(308, and AS160.The combination of OGTT and GH suppressed Akt activation, whereas the downstream expression of AS160 was amplified by GH. WE CONCLUDED THE FOLLOWING: 1 A physiological GH bolus activates STAT5 signaling pathways in skeletal muscle irrespective of ambient glucose and insulin levels 2 Insulin resistance induced by GH occurs without a distinct suppression of insulin signaling proteins 3 The accentuation of the glucose-stimulated activation of AS 160 by GH does however indicate a potential crosstalk between insulin and GH. TRIAL REGISTRATION: NCT00477997.

  10. GH administration and discontinuation in healthy elderly men

    Lange, K H; Isaksson, F; Rasmussen, M H;


    GH administration results in increased lean body mass (LBM), decreased fat mass (FM) and increased energy expenditure (EE). GH therapy may therefore have potential benefits, especially in the elderly, who are known to have decreased function of the GH/IGF-I axis. Several studies have focused...... on effects of GH administration in the elderly in the last decade. However, very limited information is available regarding changes in body composition and EE upon GH discontinuation in the elderly. The present study therefore investigated the effects of 12 weeks of GH administration and subsequent...... discontinuation on body composition, resting oxygen uptake (VO2), resting heart rate (HR) and GH related serum markers in healthy elderly men....

  11. Requirement of tyrosine residues 333 and 338 of the growth hormone (GH) receptor for selected GH-stimulated function

    Lobie, P E; Allevato, G; Norstedt, G


    We have examined the involvement of tyrosine residues 333 and 338 of the growth hormone (GH) receptor in the cellular response to GH. Stable Chinese hamster ovary (CHO) cell clones expressing a receptor with tyrosine residues at position 333 and 338 of the receptor substituted for phenylalanine (...... acetyltransferase cDNA expression driven by the GH-responsive region of the SPI 2.1 gene) was not affected by Y333F,Y338F substitution. Thus we provide the first experimental evidence that specific tyrosine residues of the GH receptor are required for selected cellular responses to GH....

  12. Growth hormone (GH) treatment reverses early atherosclerotic changes in GH-deficient adults.

    Pfeifer, M; Verhovec, R; Zizek, B; Prezelj, J; Poredos, P; Clayton, R N


    Hypopituitary patients have increased mortality from vascular disease, and in these patients, early markers of atherosclerosis [increased carotid artery intima-media thickness (IMT) and reduced distensibility] are more prevalent. As GH replacement can reverse some risk factors of atherosclerosis, the present study examined the effect of GH treatment on morphological and functional changes in the carotid and brachial arteries of GH-deficient (GHD) adults. Eleven GHD hypopituitary men (24-49 yr old) were treated with recombinant human GH (0.018 U/kg BW x day) for 18 months. IMT of the common carotid artery (CCA) and the carotid bifurcation (CB), and flow-mediated endothelium-dependent dilation (EDD) of the brachial artery were measured by B mode ultrasound before and at 3, 6, 12, and 18 months of treatment, and values were compared with those in 12 age-matched control men. Serum concentrations of lipids, lipoprotein(a), insulin-like growth factor I (IGF-I), and IGF-binding protein-3 (IGFBP-3) were also measured. In GHD men before treatment the IMTs of the CCA [mean(SD), 0.67(0.05) mm] and CB [0.75(0.04) mm] were significantly greater (P < 0.001) than those in control men [0.52(0.07) and 0.65(0.07) mm, respectively]. GH treatment normalized the IMT of the CCA by 6 months [0.53(0.04) mm] and that of the CB by 3 months [0.68(0.05) mm]. The IMT of the carotid artery (CCA and CB) was negatively correlated with serum IGF-I (r = -0.53; P < 0.0001). There was a significant improvement in flow-mediated EDD of the brachial artery at 3 months, which was sustained at 6 and 18 months of GH treatment (P < 0.05). GH treatment increased high density lipoprotein cholesterol at 3 and 6 months, but did not reduce total or low density lipoprotein cholesterol and was without effect on lipoprotein(a). There was no correlation between plasma lipids and changes in IMT or EDD of the arteries examined. In conclusion, GH treatment of hypopituitary GHD men reverses early morphological and

  13. Plasma lactate, GH and GH-binding protein levels in exercise following BCAA supplementation in athletes.

    De Palo, E F; Gatti, R; Cappellin, E; Schiraldi, C; De Palo, C B; Spinella, P


    Branched chain amino acids (BCAA) stimulate protein synthesis, and growth hormone (GH) is a mediator in this process. A pre-exercise BCAA ingestion increases muscle BCAA uptake and use. Therefore after one month of chronic BCAA treatment (0.2 gkg(-1) of body weight), the effects of a pre-exercise oral supplementation of BCAA (9.64 g) on the plasma lactate (La) were examined in triathletes, before and after 60 min of physical exercise (75% of VO2 max). The plasma levels of GH (pGH) and of growth hormone binding protein (pGHBP) were also studied. The end-exercise La of each athlete was higher than basal. Furthermore, after the chronic BCAA treatment, these end-exercise levels were lower than before this treatment (8.6+/-0.8 mmol L(-1) after vs 12.8+/-1.0 mmol L(-1) before treatment; p BCAA chronic treatment, this end-exercise pGHBP was 738+/-85 pmol L(-1) before vs 1691+/-555 pmol L(-1) after. pGH/pGHBP ratio was unchanged in each athlete and between the groups, but a tendency to increase was observed at end-exercise. The lower La at the end of an intense muscular exercise may reflect an improvement of BCAA use, due to the BCAA chronic treatment. The chronic BCAA effects on pGH and pGHBP might suggest an improvement of muscle activity through protein synthesis.

  14. A long-acting GH receptor antagonist through fusion to GH binding protein.

    Wilkinson, Ian R; Pradhananga, Sarbendra L; Speak, Rowena; Artymiuk, Peter J; Sayers, Jon R; Ross, Richard J


    Acromegaly is a human disease of growth hormone (GH) excess with considerable morbidity and increased mortality. Somatostatin analogues are first line medical treatment but the disease remains uncontrolled in up to 40% of patients. GH receptor (GHR) antagonist therapy is more effective but requires frequent high-dose injections. We have developed an alternative technology for generating a long acting potent GHR antagonist through translational fusion of a mutated GH linked to GH binding protein and tested three candidate molecules. All molecules had the amino acid change (G120R), creating a competitive GHR antagonist and we tested the hypothesis that an amino acid change in the GH binding domain (W104A) would increase biological activity. All were antagonists in bioassays. In rats all antagonists had terminal half-lives >20 hours. After subcutaneous administration in rabbits one variant displayed a terminal half-life of 40.5 hours. A single subcutaneous injection of the same variant in rabbits resulted in a 14% fall in IGF-I over 7 days.

  15. Endothelial function and vascular oxidative stress in long-lived GH/IGF-deficient Ames dwarf mice

    Csiszar, Anna; Labinskyy, Nazar; Perez, Viviana; Recchia, Fabio A.; Podlutsky, Andrej; Mukhopadhyay, Partha; Losonczy, Gyorgy; Pacher, Pal; Austad, Steven N.; Bartke, Andrzej; Ungvari, Zoltan


    Hypopituitary Ames dwarf mice have low circulating growth hormone (GH)/IGF-I levels, and they have extended longevity and exhibit many symptoms of delayed aging. To elucidate the vascular consequences of Ames dwarfism we compared endothelial O2•− and H2O2 production, mitochondrial reactive oxygen species (ROS) generation, expression of antioxidant enzymes, and nitric oxide (NO) production in aortas of Ames dwarf and wild-type control mice. In Ames dwarf aortas endothelial O2•− and H2O2 production and ROS generation by mitochondria were enhanced compared with those in vessels of wild-type mice. In Ames dwarf aortas there was a less abundant expression of Mn-SOD, Cu,Zn-SOD, glutathione peroxidase (GPx)-1, and endothelial nitric oxide synthase (eNOS). NO production and acetylcholine-induced relaxation were also decreased in aortas of Ames dwarf mice. In cultured wild-type mouse aortas and in human coronary arterial endothelial cells treatment with GH and IGF significantly reduced cellular O2•− and H2O2 production and ROS generation by mitochondria and upregulated expression of Mn-SOD, Cu,Zn-SOD, GPx-1, and eNOS. Thus GH and IGF-I promote antioxidant phenotypic changes in the endothelial cells, whereas Ames dwarfism leads to vascular oxidative stress. PMID:18757483

  16. Expression of growth hormone (GH)-releasing factor gene in GH-producing pituitary adenoma.

    Wakabayashi, I; Inokuchi, K; Hasegawa, O; Sugihara, H; Minami, S


    Pituitary cells synthesize various neuropeptides that influence pituitary hormone secretion. GH-releasing factor (GRF) may also be produced by normal or pituitary tumor cells. We examined GRF gene expression in pituitary tumors. Standard techniques for the analysis of GRF gene expression did not appear to be suitable. Highly sensitive reverse transcription coupled to polymerase chain reaction was used. Specimens of pituitary adenoma were obtained by transsphenoidal adenomectomy from six patients with acromegaly and three patients with no clinical evidence of pituitary hormone overproduction; non-functioning adenoma. Pituitary glands were collected at autopsy from three patients who died from nonendocrine disorders. A specific GRF gene transcript was detected in five out of six GH-producing pituitary adenomas, whereas this was not found in three separate specimens of nonfunctioning pituitary adenoma or anterior and posterior pituitary tissue. The data suggest that GRF is synthesized as an intrinsic product in human GH-producing pituitary adenoma.

  17. Isotopomeric characterization of N2O produced, consumed, and emitted by automobiles.

    Toyoda, Sakae; Yamamoto, Sei-ichiro; Arai, Shinji; Nara, Hideki; Yoshida, Naohiro; Kashiwakura, Kiriko; Akiyama, Ken-ichi


    Fossil fuel combustion is the second largest anthropogenic source of nitrous oxide (N2O) after agriculture. The estimated global N2O flux from combustion sources, as well as from other sources, still has a large uncertainty. Herein, we characterize automobile sources using N2O isotopomer ratios (nitrogen and oxygen isotope ratios and intramolecular site preference of 15N, SP) to assess their contributions to total global sources and to deconvolute complex production/consumption processes during combustion and subsequent catalytic treatments of exhaust. Car exhaust gases were sampled under running and idling state, and N2O isotopomer ratios were measured by mass spectrometry. The N2O directly emitted from an engine of a vehicle running at constant velocity had almost constant isotopomer ratios (delta15Nbulk = -28.7 +/- 1.2 per thousand, delta18O = 28.6 +/- 3.3 per thousand, and SP = 4.2 +/- 0.8 per thousand) irrespective of the velocity. After passing through catalytic converters, the isotopomer ratios showed an increase which varied with the temperature and the aging of the catalysts. The increase suggests that both production and consumption of N2O occur on the catalyst and that their rates can be comparable. It was noticed that in the idling state, the N2O emitted from a brand new car has higher isotopomer ratios than that from used cars, which indicate that technical improvements in catalytic converters can reduce the N2O from mobile combustion sources. On average, the isotopomeric signatures of N2O finally emitted from automobiles are not sensitive to running/idling states or to aging of the catalysts. Characteristic average isotopomer ratios of N2O from automobile sources are estimated at -4.9 +/- 8.2 per thousand, 43.5 +/- 13.9 per thousand, and 12.2 +/- 9.1 per thousand for delta15Nbulk, delta18O, and SP, respectively.

  18. Novel mutations in the GH gene (GH1) uncover putative splicing regulatory elements.

    Babu, Deepak; Mellone, Simona; Fusco, Ileana; Petri, Antonella; Walker, Gillian E; Bellone, Simonetta; Prodam, Flavia; Momigliano-Richiardi, Patricia; Bona, Gianni; Giordano, Mara


    Mutations affecting exon 3 splicing are the main cause of autosomal dominant Isolated GH Deficiency II (IGHDII) by increasing the level of exon 3-skipped mRNA encoding the functionally inactive dominant-negative 17.5-kDa isoform. The exons and introns of the gene encoding GH (GH1) were screened for the presence of mutations in 103 sporadic isolated GH deficiency cases. Four different variations within exon 3 were identified in 3 patients. One carried c.261C>T (p.Pro87Pro) and c.272A>T (p.Glu91Val), the second c.255G>A (p.Pro85Pro) and c.261 C>T, and the third c.246G>C (p.Glu82Asp). All the variants were likely generated by gene conversion from an homologous gene in the GH1 cluster. In silico analysis predicted that positions c.255 and c.272 were included within 2 putative novel exon splicing enhancers (ESEs). Their effect on splicing was confirmed in vitro. Constructs bearing these 2 variants induced consistently higher levels both of transcript and protein corresponding to the 17.5-kDa isoform. When c.255 and c.272 were combined in cis with the c.261 variant, as in our patients, their effect was weaker. In conclusion, we identified 2 variations, c.255G>A and c.272A>T, located in 2 novel putative exon splicing enhancers and affecting GH1 splicing in vitro by increasing the production of alternatively spliced isoforms. The amount of aberrant isoforms is further regulated by the presence in cis of the c.261 variant. Thus, our results evidenced novel putative splicing regulatory elements within exon 3, confirming the crucial role of this exon in mRNA processing.

  19. GH62 arabinofuranosidases: Structure, function and applications

    Wilkens, Casper; Andersen, Susan; Dumon, Claire


    Motivated by industrial demands and ongoing scientific discoveries continuous efforts are made to identify and create improved biocatalysts dedicated to plant biomass conversion. α-1,2 and α-1,3 arabinofuranosyl specific α-l-arabinofuranosidases (EC are debranching enzymes catalyzing...... exclusively α-l-arabinofuranosidases and these are of fungal and bacterial origin. Twenty-two GH62 enzymes out of 223 entries in the CAZy database have been characterized and very recently new knowledge was acquired with regard to crystal structures, substrate specificities, and phylogenetics, which overall...

  20. G.H. Mead's social behaviorism.

    Cook, G A


    This paper seeks to clarify those conceptual foundations of G.H. Mead's social behaviorism which are assumed, but not made explicit, in that writer's well-known volume Mind, Self and Society. These foundations are shown to be an outgrowth of Mead's early commitment to the organic conception of conduct underlying the psychological functionalism of the Chicago School. Further light is shed upon Mead's position by pointing out the fundamental differences between his model of conduct and that characteristic of the behaviorist tradition in American psychology.

  1. Molecular evidence for the involvement of a polygalacturonase-inhibiting protein, GhPGIP1, in enhanced resistance to Verticillium and Fusarium wilts in cotton

    Liu, Nana; Zhang, Xueyan; Sun, Yun; Wang, Ping; Li, Xiancai; Pei, Yakun; Li, Fuguang; Hou, Yuxia


    Polygalacturonase-inhibiting protein (PGIP), belonging to a group of plant defence proteins, specifically inhibits endopolygalacturonases secreted by pathogens. Herein, we showed that purified GhPGIP1 is a functional inhibitor of Verticillium dahliae and Fusarium oxysporum f. sp. vasinfectum, the two fungal pathogens causing cotton wilt. Transcription of GhPGIP1 was increased in cotton upon infection, wounding, and treatment with defence hormone and H2O2. Resistance by GhPGIP1 was examined by its virus-induced gene silencing in cotton and overexpression in Arabidopsis. GhPGIP1-silenced cotton was highly susceptible to the infections. GhPGIP1 overexpression in transgenic Arabidopsis conferred resistance to the infection, accompanied by enhanced expression of pathogenesis-related proteins (PRs), isochorismate synthase 1 (ICS1), enhanced disease susceptibility 1 (EDS1), and phytoalexin-deficient 4 (PAD4) genes. Transmission electron microscopy revealed cell wall alteration and cell disintegration in plants inoculated with polygalacturonase (PGs), implying its role in damaging the cell wall. Docking studies showed that GhPGIP1 interacted strongly with C-terminal of V. dahliae PG1 (VdPG1) beyond the active site but weakly interacted with C-terminal of F. oxysporum f. sp. vasinfectum (FovPG1). These findings will contribute towards the understanding of the roles of PGIPs and in screening potential combat proteins with novel recognition specificities against evolving pathogenic factors for countering pathogen invasion. PMID:28079053

  2. Should we start and continue growth hormone (GH) replacement therapy in adults with GH deficiency?

    ter Maaten, JC


    During the last decade, growth hormone deficiency (GHD) in adults has been described as a clinical syndrome. Central features of this entity include increased fat mass, reduced muscle and bone mass, as well as impaired exercise capacity and quality of life. GH replacement therapy has been initiated

  3. Primary empty sella and GH deficiency: prevalence and clinical implications

    Maurizio Poggi


    Full Text Available Primary empty sella (PES is a particular anatomical condition characterized by the herniation of liquor within the sella turcica. The pathogenesis of this alteration, frequently observed in general population, is not yet completely understood. Recently reports demonstrated, in these patients, that hormonal pituitary dysfunctions, specially growth hormone (GH/insulin-like growth factor (IGF-I axis ones, could be relevant. The aim of this paper is to evaluate GH/IGF-I axis in a group of adult patients affected by PES and to verify its clinical relevance. We studied a population of 28 patients with a diagnosis of PES. In each patient we performed a basal study of thyroid, adrenal and gonadal - pituitary axis and a dynamic evaluation of GH/IGF-I after GH-releasing hormone (GHRH plus arginine stimulation test. To evaluate the clinical significance of GH/IGF-I axis dysfunction we performed a metabolic and bone status evaluation in every patients. We found the presence of GH deficit in 11 patients (39.2 %. The group that displayed a GH/IGF-I axis dysfunction showed an impairment in metabolic profile and bone densitometry. This study confirms the necessity to screen the pituitary function in patients affected by PES and above all GH/IGF-I axis. Moreover the presence of GH deficiency could be clinically significant.

  4. Equilibrium in the clinoptilolite-H{sub 2}O system

    Carey, J.W.; Bish, D.L. [Los Alamos National Lab., NM (United States)


    A thermodynamic formulation for the sorption of H{sub 2}O in clinoptilolite has been obtained from analysis of equilibrium data collected by thermogravimetry on near endmember Ca-, Na-, and K-exchanged natural clinoptilolite (Fish Creek Mountains, Nevada). Temperature and pressure of the experiments ranged from 25 to 250 {degrees}C and 0.2 to 35 mbar H{sub 2}O vapor pressure. Equilibrium of three clinoptilolite species was successfully formulated with the following expression for the Gibbs free energy of hydration as a function of temperature and pressure: {Delta}{mu}{sub Hy}/T = {Delta}{mu}{sub Hy}{sup 0}/T{sub 0} + {Delta}H{sub Hy}{sup 0}(1/T - 1/T{sub 0}) - 3R[ln(T/T{sub 0}) + (T{sub 0}/T - 1)] + R ln[{theta}/(1 - {theta})P] + W{sub 1}/T{theta} + W{sub 2}/T{theta}{sup 2} where R is the gas constant, P is the vapor pressure of H{sub 2}O, W{sub 1} and W{sub 2} are the excess mixing parameters, and {theta} is the ratio H{sub 2}O/(maximum H{sub 2}O) with maximum water contents for the K, Na, and Ca end-members of 13.49, 15.68, and 16.25 wt%, respectively. The molar Gibbs free energy of hydration for calcium, sodium, and potassium clinoptilolite is -36.13 {plus_minus} 3.02, -29.68 {plus_minus} 3.77, and -25.53 {plus_minus} 1.37 kJ/mol H{sub 2}O, respectively. The molar enthalpy of hydration for these phases is -76.92 {plus_minus} 2.88, -74.19 {plus_minus} 3.46, and -67.78 {plus_minus} 1.25 kJ/mol H{sub 2}O. The thermodynamic formulation is applied to the occurrence of clinoptilolite at Yucca Mountain, Nevada, where the proposed emplacement of nuclear waste would lead to heating of clinoptilolite-bearing tuffs. Rock units with abundant clinoptilolite (or by analogy other hydrous phases) would remain significantly cooler than units with anhydrous minerals and would evolve a substantial volume of water. 21 refs., 11 figs., 5 tabs.

  5. Continuation of growth hormone (GH) therapy in GH-deficient patients during transition from childhood to adulthood

    Nørrelund, Helene; Vahl, N; Juul, A


    -controlled, parallel study. Measurements were made at baseline, where all patients were on their regular GH replacement, after 12 months of either continued GH (0.018 +/- 0.001 mg/kg day) or placebo, and finally after 12 months of open phase GH therapy (0.016 mg/kg x day). Before study entry GH deficiency...... fat and increased fat-free mass [M-value (mg/kg x min), 5.1 +/- 0.7 (placebo) vs. 3.4 +/- 1.0 (open), P = 0.09]. In the group randomized to continued GH treatment almost all hormonal and metabolic parameters remained unchanged during the study. In conclusion, 1) discontinuation of GH therapy for 1 yr...

  6. Growth hormone (GH)-releasing hormone and GH secretagogues in normal aging: Fountain of Youth or Pool of Tantalus?

    Elizabeth C Hersch; Merriam, George R.


    Elizabeth C Hersch, George R MerriamVA Puget Sound Health Care System and University of Washington School of Medicine, Tacoma and Seattle, Washington USAAbstract: Although growth hormone (GH) is primarily associated with linear growth in childhood, it continues to have important metabolic functions in adult life. Adult GH deficiency (AGHD) is a distinct clinical entity, and GH replacement in AGHD can improve body composition, strength, aerobic capacity, and mood, and may reduce vascular disea...

  7. Delta III—an evolutionary delta growth

    Arvesen, R. J.; Simpson, J. S.


    In order to remain competitive in the future and expand the McDonnell Douglas Aerospace market share, MDA has developed an expendable launch system strategy that devices cost-effective launch systems from the Delta II with a growth vehicle configuration called Delta III. The Delta III evolves from the Delta II launch system through development of a larger payload fairing (4-meter diameter), new cryogenically propelled upper stage, new first stage fuel tank, and larger strap-on solid rocket motors. We are developing the Delta III using Integrated Product Development Teams that capitalize on the experience base that has led us to a world record breaking mission success of 49 consecutive Delta II missions. The Delta III first-launch capability is currently planned for the spring of 1998 in support of our first spacecraft customer, Hughes Space and Communications International.

  8. No Improvement of Adult Height in Non-growth Hormone (GH) Deficient Short Children with GH Treatment

    Tanaka, Toshiaki; Fujieda, Kenji; Yokoya, Susumu; Shimatsu, Akira; Tachibana, Katsuhiko; Tanaka, Hiroyuki; Tanizawa, Takakuni; Teramoto, Akira; Nagai, Toshiro; Nishi, Yoshikazu; Hasegawa, Yukihiro; Hanew, Kunihiko; Fujita, Keinosuke; Horikawa, Reiko; Takada, Goro


    It is still in doubt whether the standard-dose growth hormone (GH) used in Japan (0.5 IU/kg/week, 0.167 mg/kg/week) for growth hormone deficiency is effective for achieving significant adult height improvement in non-growth hormone deficient (non-GHD) short children. We compared the growth of GH-treated non-GHD short children with that of untreated short children to examine the effect of standard-dose GH treatment on non-GHD short children. GH treatment with recombinant human growth hormone (...

  9. The Delta 2 launcher

    Ousley, Gilbert W., Sr.


    The utilization of the Delta 2 as the vehicle for launching Aristoteles into its near Sun synchronous orbit is addressed. Delta is NASA's most reliable launch vehicle and is well suited for placing the present Aristoteles spacecraft into a 400 m circular orbit. A summary of some of the Delta 2 flight parameters is presented. Diagrams of a typical Delta 2 two stage separation are included along with statistics on delta reliability and launch plans.

  10. Increased serum and bone matrix levels of transforming growth factor {beta}1 in patients with GH deficiency in response to GH treatment

    Ueland, Thor; Lekva, Tove; Otterdal, Kari


    Patients with adult onset GH deficiency (aoGHD) have secondary osteoporosis, which is reversed by long-term GH substitution. Transforming growth factor β1 (TGFβ1 or TGFB1) is abundant in bone tissue and could mediate some effects of GH/IGFs on bone. We investigated its regulation by GH/IGF1 in vivo...

  11. Longitudinal study of serum placental GH in 455 normal pregnancies

    Chellakooty, Marla; Skibsted, Lillian; Skouby, Sven Olaf


    Placental GH is thought to be responsible for the rise in maternal IGF-I during pregnancy and is considered to be important for fetal growth. In this prospective longitudinal study of healthy pregnant women, we investigated determinants of placental GH in maternal serum. Serum was obtained from 4...

  12. N2O and NOy

    Kawa, S. R.; Jackman, C. H.; Douglass, A. R.; Strahan, S. E.


    The principal loss processes for ozone in the stratosphere are either directly or indirectly closely coupled to the abundance and distribution of reactive oxides of nitrogen (NOy). The main source of NOy in the stratosphere is N2O, a trace gas that is changing significantly as a result of anthropogenic forcing. Thus diagnosis of the distributions of N2O, NOy, and their coupling is required to evaluate any chemistry-climate model aspiring to accurately simulate ozone change. In the NASA Assessment of the Effects of High-speed Aircraft in the Stratosphere: 1998 we found that the sensitivity of various models ozone to perturbation did correspond consistently with their background NOy distribution. Coordinated NOy and N2O mixing ratio distributions are available from observations: ER-2 aircraft in the lower stratosphere and ATMOS and balloon profiles to higher altitudes at a subset of latitudes and seasons. Although close comparison to these diagnostics is crucial, unfortunately the distributions are due to a combination of transport and chemical processes, and isolating the source of differences is not always simple. However, in combination with other transport and photochemical diagnostics, comparison with N2O and NOy can be very instructive in evaluation of model processes and performance.

  13. El receptor de la hormona de crecimiento humana (hGH y la proteína de transporte de alta afinidad de la hGH Human Growth Hormone (GH Receptor and the High Affinity GH-Binding Protein

    María Gabriela Ballerini


    Full Text Available La hormona de crecimiento humana (hGH circula parcialmente unida a su proteína de transporte de alta afinidad (GHBP la cual resulta del clivaje proteolítico del dominio extracelular del receptor de GH. Recientemente la enzima TACE se identificó como la metaloproteasa responsable del clivaje y liberación de GHBP a circulación. Aunque aún se desconoce la función específica de esta proteína de transporte, distintos trabajos en la literatura demuestran efectos que potencian y efectos inhibitorios sobre la acción de GH. Por otro lado, existen evidencias que demuestran una fuerte relación entre la GHBP y el nivel de receptor de GH en el hígado en situaciones fisiológicas y patológicas. Esto permitió proponer a la determinación de GHBP en suero como un marcador periférico de la abundancia del receptor de GH en los tejidos. La determinación de la concentración de GHBP sería de especial interés para evaluar pacientes con diagnóstico probable de insensibilidad a la acción de GH y orientar el posterior estudio de anormalidades en el gen del receptor de GH. En la presente revisión, también se abordan dificultades metodológicas relacionadas a la medición de GHBP sérica.Human circulating growth hormone (GH is partly bound to a high-affinity binding protein (GHBP which is derived from proteolytical cleavage of the extracellular domain of the GH receptor. Recently, the metalloproteinase TACE has been identified as an important enzyme responsive for inducing GHBP shedding. Although the specific function of GHBP is not fully known, both enhancing and inhibitory roles of this binding protein on GH action have been proposed. Many reports have demonstrated a close relationship between GHBP and the liver GH receptor status in physiological conditions and diseases. Moreover, serum GHBP measurement has been proposed as an useful peripheral index of the GH receptor abundance. Related to the latter, circulating GHBP concentration would be of

  14. Effect of cessation of GH treatment on cognition during transition phase in Prader-Willi syndrome: results of a 2-year crossover GH trial

    Kuppens, R. J.; Mahabier, E. F.; Bakker, N. E.; Siemensma, E. P. C.; Donze, S.H.; Hokken-Koelega, A. C. S.


    Background Patients with Prader-Willi syndrome (PWS) have a cognitive impairment. Growth hormone (GH) treatment during childhood improves cognitive functioning, while cognition deteriorates in GH-untreated children with PWS. Cessation of GH treatment at attainment of adult height (AH) might deteriorate their GH-induced improved cognition, while continuation might benefit them. We, therefore, investigated the effects of placebo versus GH administration on cognition in young adults with PWS who...

  15. Blockade of the growth hormone (GH) receptor unmasks rapid GH-releasing peptide-6-mediated tissue-specific insulin resistance

    A.F. Muller (Alex); L.J. Hofland (Leo); S.W.J. Lamberts (Steven); M. Bidlingmaier (Martin); C.J. Strasburger; J.A.M.J.L. Janssen (Joseph); A-J. van der Lely (Aart-Jan)


    textabstractThe roles of GH and its receptor (GHR) in metabolic control are not yet fully understood. We studied the roles of GH and the GHR using the GHR antagonist pegvisomant for metabolic control of healthy nonobese men in fasting and nonfasting conditions. Ten heal

  16. GH safety workshop position paper: a critical appraisal of recombinant human GH therapy in children and adults.

    Allen, D B; Backeljauw, P; Bidlingmaier, M; Biller, B M K; Boguszewski, M; Burman, P; Butler, G; Chihara, K; Christiansen, J; Cianfarani, S; Clayton, P; Clemmons, D; Cohen, P; Darendeliler, F; Deal, C; Dunger, D; Erfurth, E M; Fuqua, J S; Grimberg, A; Haymond, M; Higham, C; Ho, K; Hoffman, A R; Hokken-Koelega, A; Johannsson, G; Juul, A; Kopchick, J; Lee, P; Pollak, M; Radovick, S; Robison, L; Rosenfeld, R; Ross, R J; Savendahl, L; Saenger, P; Toft Sorensen, H; Stochholm, K; Strasburger, C; Swerdlow, A; Thorner, M


    Recombinant human GH (rhGH) has been in use for 30 years, and over that time its safety and efficacy in children and adults has been subject to considerable scrutiny. In 2001, a statement from the GH Research Society (GRS) concluded that 'for approved indications, GH is safe'; however, the statement highlighted a number of areas for on-going surveillance of long-term safety, including cancer risk, impact on glucose homeostasis, and use of high dose pharmacological rhGH treatment. Over the intervening years, there have been a number of publications addressing the safety of rhGH with regard to mortality, cancer and cardiovascular risk, and the need for long-term surveillance of the increasing number of adults who were treated with rhGH in childhood. Against this backdrop of interest in safety, the European Society of Paediatric Endocrinology (ESPE), the GRS, and the Pediatric Endocrine Society (PES) convened a meeting to reappraise the safety of rhGH. The ouput of the meeting is a concise position statement.

  17. Clinical features of GH deficiency and effects of 3 years of GH replacement in adults with controlled Cushing's disease

    Höybye, Charlotte; Ragnarsson, Oskar; Jönsson, Peter J;


    Patients in remission from Cushing's disease (CD) have many clinical features that are difficult to distinguish from those of concomitant GH deficiency (GHD). In this study, we evaluated the features of GHD in a large cohort of controlled CD patients, and assessed the effect of GH treatment....

  18. GH safety workshop position paper: a critical appraisal of recombinant human GH therapy in children and adults

    Allen, D B; Backeljauw, P; Bidlingmaier, M; Biller, B M K; Boguszewski, M; Burman, P; Butler, G; Chihara, K; Christiansen, J; Cianfarani, S; Clayton, P; Clemmons, D; Cohen, P; Darendeliler, F; Deal, C; Dunger, D; Erfurth, E M; Fuqua, J S; Grimberg, A; Haymond, M; Higham, C; Ho, K; Hoffman, A R; Hokken-Koelega, A; Johannsson, G; Juul, A; Kopchick, J; Lee, P; Pollak, M; Radovick, S; Robison, L; Rosenfeld, R; Ross, R J; Savendahl, L; Saenger, P; Toft Sorensen, H; Stochholm, K; Strasburger, C; Swerdlow, A; Thorner, M


    Recombinant human GH (rhGH) has been in use for 30 years, and over that time its safety and efficacy in children and adults has been subject to considerable scrutiny. In 2001, a statement from the GH Research Society (GRS) concluded that ‘for approved indications, GH is safe’; however, the statement highlighted a number of areas for on-going surveillance of long-term safety, including cancer risk, impact on glucose homeostasis, and use of high dose pharmacological rhGH treatment. Over the intervening years, there have been a number of publications addressing the safety of rhGH with regard to mortality, cancer and cardiovascular risk, and the need for long-term surveillance of the increasing number of adults who were treated with rhGH in childhood. Against this backdrop of interest in safety, the European Society of Paediatric Endocrinology (ESPE), the GRS, and the Pediatric Endocrine Society (PES) convened a meeting to reappraise the safety of rhGH. The ouput of the meeting is a concise position statement. PMID:26563978

  19. Continuous infusion versus daily injections of growth hormone (GH) for 4 weeks in GH-deficient patients

    Laursen, Torben; Jørgensen, Jens Otto Lunde; Jakobsen, Grethe


    infusion by means of a portable pump for 1 month and as daily sc injections (at 1900 h) for another month. An average daily GH dosage (+/- SEM) of 3.15 +/- 0.27 IU was administered during both periods. Steady state 24-h profiles of GH, IGF-I, IGF-binding proteins (IGFBPs), insulin, glucose, lipid......Abstract Endogenous GH secretion is pulsatile. Animal studies indicate that GH administered in a pulsatile manner induces growth and insulin-like growth factor I (IGF-I) generation more effectively than continuous administration. Short term human studies, however, have reported similar metabolic.......5 +/- 50.2 (injection) and 334.6 +/- 46.6 (infusion)]. Similarly, constant GH delivery induced higher IGFBP-3 levels (P insulin levels (P

  20. Considering GH replacement for GH-deficient adults with a previous history of cancer: a conundrum for the clinician.

    Yuen, Kevin C J; Heaney, Anthony P; Popovic, Vera


    Previous studies have shown that GH and IGF-I may enhance tumorigenesis, metastasis, and cell proliferation in humans and animals. Evidence supporting this notion is derived from animal model studies, epidemiological studies, experience from patients with acromegaly, molecular therapeutic manipulation of GH and IGF-I actions, and individuals with GH receptor and congenital IGF-I deficiencies. Prior exposure to radiation therapy, aging, family history of cancer, and individual susceptibility may also contribute to increase this risk. Therefore, the use of GH replacement in patients with a history of cancer raises hypothetical safety concerns for patients, caregivers, and providers. Studies of GH therapy in GH-deficient adults with hypopituitarism and childhood cancer survivors have not convincingly demonstrated an increased cancer risk. Conversely, the risk of occurrence of a second neoplasm (SN) in childhood cancer survivors may be increased, with meningiomas being the most common tumor; however, this risk appears to decline over time. In light of these findings, if GH replacement is to be considered in patients with a previous history of cancer, we propose this consideration to be based on each individual circumstance and that such therapy should only be initiated at least 2 years after cancer remission is achieved with the understanding that in some patients (particularly those with childhood cancers), GH may potentially increase the risk of SNs. In addition, close surveillance should be undertaken working closely with the patient's oncologist. More long-term data are thus needed to determine if GH replacement in GH-deficient adults with a history of cancer is associated with the development of de novo tumors and tumor recurrence.

  1. Theoretical Modeling of Water Exchange on [Pd(H(2)O)(4)](2+), [Pt(H(2)O)(4)](2+), and trans-[PtCl(2)(H(2)O)(2)].

    Deeth, Robert J.; Elding, Lars I.


    Density functional theory is applied to modeling the exchange in aqueous solution of H(2)O on [Pd(H(2)O)(4)](2+), [Pt(H(2)O)(4)](2+), and trans-[PtCl(2)(H(2)O)(2)]. Optimized structures for the starting molecules are reported together with trigonal bipyramidal (tbp) systems relevant to an associative mechanism. While a rigorous tbp geometry cannot by symmetry be the actual transition state, it appears that the energy differences between model tbp structures and the actual transition states are small. Ground state geometries calculated via the local density approximation (LDA) for [Pd(H(2)O)(4)](2+) and relativistically corrected LDA for the Pt complexes are in good agreement with available experimental data. Nonlocal gradient corrections to the LDA lead to relatively inferior structures. The computed structures for analogous Pd and Pt species are very similar. The equatorial M-OH(2) bonds of all the LDA-optimized tbp structures are predicted to expand by 0.25-0.30 Å, while the axial bonds change little relative to the planar precursors. This bond stretching in the transition state counteracts the decrease in partial molar volume caused by coordination of the entering water molecule and can explain qualitatively the small and closely similar volumes of activation observed. The relatively higher activation enthalpies of the Pt species can be traced to the relativistic correction of the total energies while the absolute DeltaH() values for exchange on [Pd(H(2)O)(4)](2+) and [Pt(H(2)O)(4)](2+) are reproduced using relativistically corrected LDA energies and a simple Born model for hydration. The validity of the latter is confirmed via some simple atomistic molecular mechanics estimates of the relative hydration enthalpies of [Pd(H(2)O)(4)](2+) and [Pd(H(2)O)(5)](2+). The computed DeltaH() values are 57, 92, and 103 kJ/mol compared to experimental values of 50(2), 90(2), and 100(2) kJ/mol for [Pd(H(2)O)(4)](2+), [Pt(H(2)O)(4)](2+), and trans-[PtCl(2)(H(2)O)(2

  2. Delta Plaza kohvik = Delta Plaza cafe


    Tallinnas Pärnu mnt 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Tiiu Truusi tähtsamate tööde loetelu. Büroohoone Delta Plaza arhitektid Marika Lõoke ja Jüri Okas (AB J. Okas & M. Lõoke)

  3. Delta Plaza kohvik = Delta Plaza cafe


    Tallinnas Pärnu mnt 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Tiiu Truusi tähtsamate tööde loetelu. Büroohoone Delta Plaza arhitektid Marika Lõoke ja Jüri Okas (AB J. Okas & M. Lõoke)

  4. The influence of V{sub 2}O{sub 5} on dielectric properties of PbO-B{sub 2}O{sub 3}-Bi{sub 2}O{sub 3} glasses

    Padmanabham, A [G.V.V.R. Institute of Technology, Vempa Road, Bhimavaram-534 207, A.P. (India); Gandhi, Y; Rao, M V Ramachandra; Appaji, D V M [Department of Physics, Acharya Nagarjuna University-Nuzvid Campus, Nuzvid-521 201, A.P. (India); Rao, M V N Padma, E-mail: [Department of Physiscs, P.B. Siddhartha Degree College, Vijayawada, A.P. (India)


    The influence of V{sub 2}O{sub 5} (ranging from 0 to 1.0 mol %) on the structural aspects of PbO-B{sub 2}O{sub 3}-Bi{sub 2}O{sub 3} glass system, from a systematic study of dielectric properties (dielectric constant {epsilon}, loss tan {delta} and a.c. conductivity {sigma}ac, over a wide range of frequency and temperature) and IR spectra has been investigated. The dielectric constant {epsilon}'and loss at room temperature (30 deg. C) and at 100 kHz of pure PbO-B{sub 2}O{sub 3}-Bi{sub 2}O{sub 3} glasses are measured to be 9.61 and 0.0013 respectively. These values are found to increase with the decrease in frequency. The dielectric constant and loss have been observed with increase in the concentration of V{sub 2}O{sub 5} (up to 1.0 mol %). In the IR spectra of PbO-Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3}: V{sub 2}O{sub 5} glasses, the intensity of the band due to BO{sub 3} structural units is observed to grow at the expense of more ordered BO{sub 4} structural units with the increase in the concentration of V{sub 2}O{sub 5} up to 1.0 mol %. The analysis of these results indicated that as the concentration of V{sub 2}O{sub 5} is raised up to 1.0 mol %, there is a growing degree of disorder in the glass network.

  5. Thyroid function in children with growth hormone (GH deficiency during the initial phase of GH replacement therapy - clinical implications

    Smyczynska Joanna


    Full Text Available Abstract Background Normal thyroid hormone secretion or appropriate L-thyroxine (L-T4 substitution is necessary for the optimal effect of the growth hormone (GH administration on growth rate. The decrease of free thyroxine (FT4 levels at recombinant human GH (rhGH therapy onset has been reported in several studies. The aim of the present study was to evaluate the effect of rhGH administration on thyrotropin (TSH and FT4 serum concentrations in children with GH deficiency (GHD during the 1st year of therapy, as well as to assess potential indications to thyroid hormone supplementation in them. Patients and methods The analysis involved data of 75 children (59 boys, 16 girls with disorders of GH secretion (GHD, neurosecretory dysfunction - NSD and partial GH inactivity (inactGH, who were treated with rhGH for - at least - one year. In all the children, body height and height velocity (HV were assessed before and after 1 year of therapy, while TSH, FT4, IGF-I and IGFBP-3 before treatment and after 3-6 months and 1 year of treatment. In the patients, who revealed hypothyroidism (HypoT, an appropriate L-T4 substitution was introduced immediately. The incidence of HypoT, occurring during the initial phase of rhGH therapy, was assessed, as well as its influence on the therapy effectiveness. Results Before rhGH substitution, there were no significant differences in either auxological indices or TSH and FT4 secretion, or IGF-I concentration and its bioavailability among the groups of patients. During the initial 3-6 months of rhGH administration, a significant decrease of FT4 serum concentration, together with a significant increase of IGF-I SDS and IGF-I/IGFBP-3 molar ratio was observed in all the studied groups. In 17 children, HypoT was diagnosed and L-T4 substitution was administered. Despite similar IGF-I secretion increase, the improvement of HV presented significantly lower in children with HypoT than in those who remained euthyroid all the time

  6. Expression of endogenous and exogenous growth hormone (GH) messenger (m) RNA in a GH-transgenic tilapia (Oreochromis niloticus).

    Caelers, Antje; Maclean, Norman; Hwang, Gyulin; Eppler, Elisabeth; Reinecke, Manfred


    We have previously produced transgenic fish from crosses between a wild-type female tilapia (Oreochromis niloticus) and a G transgenic male. This line of growth-enhanced tilapia carries a single copy of a chinook salmon (s) growth hormone (GH) gene spliced to an ocean pout antifreeze promoter (OPA-FPcsGH) co-ligated to a carp beta-actin/lacZ reporter gene construct, integrated into the tilapia genome. Because little is known about the expression sites of transgenes, we have characterised the gene expression patterns of sGH and tilapia (t)GH in transgenic tilapia using a newly established real-time PCR to measure the absolute mRNA amounts of both hormones. The sGH gene, which was expected to be expressed mainly in liver, was also found to be expressed in other organs, such as gills, heart, brain, skeletal muscle, kidney, spleen, intestine and testes. However, in pituitary no sGH mRNA but only tGH mRNA was found. Tilapia GH mRNA in wild-type pituitary amounted to 226 +/- 30 pg/microg total RNA but in transgenics only to 187 +/- 43 pg/microg total RNA. Liver exhibited the highest level of sGH mRNA (8.3 +/- 2.5 pg/microg total RNA) but the extrahepatic sites expressed considerable amounts of sGH mRNA ranging from 4.1 +/- 2.0 pg/microg total RNA in gills to 0.2 +/- 0.08 pg/microg total RNA in kidney. The widespread expression of the sGH gene is assumed to be due to the tissue specificity of the type III AFP gene promoter. It is assumed that our transgenic experiments, which in contrast to some other approaches caused no obvious organ abnormalities, mimick the GH expression during ontogeny. Because sGH mRNA is expressed both in liver and in extrahepatic sites it may not only promote secretion and release of liver-derived (endocrine) IGF-I leading to an overall growth enhancement but also stimulate IGF-I expression within the different organs in a paracrine/autocrine manner and, thus, further promote organ growth.

  7. Low doses of estradiol partly inhibit release of GH in sheep without affecting basal levels.

    Hudmon, A; Davenport, G; Coleman, E S; Sartin, J L


    Estradiol increases basal growth hormone (GH) concentrations in sheep and cattle. This study sought to determine the effects of estradiol on GH-releasing hormone (GRH)-stimulated GH release in sheep. Growth hormone secretory characteristics, the GH response to GRH, and steady-state GH mRNA concentrations were determined in castrated male lambs treated with 2 different doses of estradiol 17-beta for a 28-d experimental period. Although no differences between treatments in mean GH, basal GH, or GH pulse number were observed after 28 d of estradiol treatment, GH pulse amplitude was greater (P GRH-stimulated GH release revealed differences between the control and estradiol-treated animals (P GRH. These data suggest that estradiol has differing actions on basal and GRH-stimulated GH concentrations in plasma, but the increase in pulse amplitude does not represent an increased pituitary sensitivity to GRH.

  8. The Vaporization of B2O3(l) to B2O3(g) and B2O2(g)

    Jacobson, Nathan S.; Myers, Dwight L.


    The vaporization of B2O3 in a reducing environment leads to formation of both B2O3(g) and B2O2(g). While formation of B2O3(g) is well understood, many questions about the formation of B2O2(g) remain. Previous studies using B(s) + B2O3(l) have led to inconsistent thermodynamic data. In this study, it was found that after heating, B(s) and B2O3(l) appear to separate and variations in contact area likely led to the inconsistent vapor pressures of B2O2(g). To circumvent this problem, an activity of boron is fixed with a two-phase mixture of FeB and Fe2B. Both second and third law enthalpies of formation were measured for B2O2(g) and B2O3(g). From these the enthalpies of formation at 298.15 K are calculated to be -479.9 +/- 41.5 kJ/mol for B2O2(g) and -833.4 +/- 13.1 kJ/mol for B2O3(g). Ab initio calculations to determine the enthalpies of formation of B2O2(g) and B2O3(g) were conducted using the W1BD composite method and show good agreement with the experimental values.

  9. Longitudinal study of serum placental GH in 455 normal pregnancies

    Chellakooty, Marla; Skibsted, Lillian; Skouby, Sven O


    women with normal singleton pregnancies at approximately 19 and 28 wk gestation. Serum placental GH concentrations were measured by a highly specific immunoradiometric assay, and fetal size was measured by ultrasound. Data on birth weight, gender, prepregnancy body mass index (BMI), parity, and smoking.......002). Placental GH at second examination was positively correlated with gestational age (P = 0.002) and negatively correlated with prepregnancy BMI (P = 0.039). Placental GH correlated with fetal weight at approximately 28 wk gestation (P = 0.002) but did not predict birth weight at term. Our study supports...

  10. GH responses to growth hormone releasing factor in depression.

    Thomas, R; Beer, R; Harris, B; John, R; Scanlon, M


    The growth hormone (GH), thyrotrophin (TSH) and prolactin response to growth hormone releasing factor (GRF) was investigated in 18 patients suffering from major depression with melancholia and in 18 age- and sex-matched normal controls. There was no significant difference in the GH response to GRF stimulation between the patients and controls and in neither subject group was there a demonstrable TSH or prolactin response to GRF. These findings indicate that the pathophysiology underlying the blunted GH response to pharmacological challenge, demonstrated in other studies, must lie at a suprapituitary level.

  11. Effect of growth hormone (GH)-releasing hormone (GRH) on plasma GH in relation to magnitude and duration of GH deficiency in 26 children and adults with isolated GH deficiency or multiple pituitary hormone deficiencies: evidence for hypothalamic GRH deficiency.

    Schriock, E A; Lustig, R H; Rosenthal, S M; Kaplan, S L; Grumbach, M M


    Synthetic, amidated, 44 amino acid GH-releasing hormone ( GRH -44) was administered iv at a dose of 5 micrograms/kg to 20 patients with severe GH deficiency (GHD), 6 children and adolescents with partial GHD, and 6 non-GH deficient ( NGHD ) children and adolescents. The 17 patients with severe GHD that responded to GRH -44 had lower peak concentrations of plasma GH than the NGHD individuals (5.0 +/- 1.2 (SEM) vs. 27.2 +/- 3.5 ng/ml; P less than 0.0001). The children and adolescents with severe GHD tended to have higher peak GH responses to GRH -44 than the GHD adults (6.9 +/- 1.7 vs. 2.4 +/- 0.3 ng/ml) although the difference was not significant. The peak GH concentration was attained earlier in the GHD children and adolescents than in the GHD adults (28 +/- 4.7 vs. 69.3 +/- 13 min, P less than 0.004). There was a negative correlation between chronological age and peak plasma GH response to GRH in the children and adolescents with severe GHD (r = -0.758, P less than 0.02). Children and adolescents with partial GHD had a higher mean peak concentration of plasma GH (13. 1 +/- 1.8 ng/ml) than the children, adolescents, and adults with severe GHD (P less than 0.04), but one lower than the NGHD children and adolescents (P less than 0.05). In both severe and partial GHD the GH response to GRH was greater than that elicited by standard pharmacological tests. Serum somatomedin-C did not increase after a single pulse of GRH -44 in the 12 GHD patients studied. PRL increased minimally 30 min after 5 micrograms/kg iv GRH -44 in patients with multiple hypothalamic-pituitary hormone deficiencies but not in patients with isolated GHD or in NGHD individuals. The GH responses to GRH suggest that the majority of patients with isolated GHD as well as those with multiple hypothalamic-pituitary hormone deficiencies have deficiency of hypothalamic GRH . Lack of a GH response to a single pulse of GRH does not exclude GRH deficiency as priming of the somatotrope with multiple pulses of

  12. Usefulness of growth hormone (GH) stimulation tests and IGF-I concentration measurement in GH deficiency diagnosis.

    Obara-Moszyńska, Monika; Kedzia, Andrzej; Korman, Eugeniusz; Niedziela, Marek


    The diagnosis of growth hormone (GH) deficiency (GHD) is still problematic for the clinician. There is no gold standard for estimating GH secretion. The aim of this study was to compare the diagnostic usefulness of spontaneous GH secretion test, pharmacological tests with insulin, clonidine, L-dopa, and glucagon, and IGF-I measurement in GHD. We studied 180 prepubertal, short children. Predictive values were calculated for different GH cutoff levels for each diagnostic test. ROC curves were used to estimate the diagnostic usefulness of the tests. The results show that sleep is the strongest stimulatory agent for GH secretion. The estimation of GH secretion after onset of sleep can be used as a screening test in GHD diagnosis. The insulin test has the highest discrimination. A combination of insulin test with another provocative test allows high discrimination and accuracy for standard cut-off GH level. Measurement of IGF-I is characterized by low predictive values. IGF-I level below the mean according to age indicates high probability of GHD. Auxological parameters should be the most important factor in diagnosing GHD.

  13. Discordance between growth hormone (GH) responses after GH-releasing hormone and insulin hypoglycemia in myotonic dystrophy.

    Okimura, Y; Chihara, K; Kita, T; Kashio, Y; Sato, M; Kitajima, N; Abe, H; Takahashi, K; Fujita, T


    Plasma GH responses to human GHRH, arginine, L-dopa, and insulin-induced hypoglycemia were determined in seven myotonic dystrophy (MD) patients. An iv bolus injection of GHRH-(1-44)-NH2 (1 microgram/kg BW) only slightly increased plasma GH concentrations in MD patients. The mean peak plasma GH level after GHRH injection [4.2 +/- 0.8 (+/- SE) micrograms/L] was significantly lower than that in 10 age-matched normal subjects (26.7 +/- 4.3 micrograms/L) or that in 6 patients with progressive muscular dystrophy (22.8 +/- 6.6 micrograms/L) whose nutritional status was similar to that of the MD patients. Even with a larger dose of GHRH (3 micrograms/kg BW), the plasma GH rises were minimal in the MD patients (mean peak, 5.9 +/- 1.8 micrograms/L). The plasma GH responses to a 30-min iv infusion of arginine (0.5 g/kg BW) and oral ingestion of L-dopa (0.5 g) were attenuated to a similar extent, whereas insulin-induced hypoglycemia caused a significant increase in plasma GH in all seven MD patients [mean peak, 17.4 +/- 4.1 (+/- SE) microgram/L]. The plasma TSH responses to TRH and plasma insulin-like growth factor I levels were similar in the MD patients and normal subjects. These findings suggest that 1) the impaired GH release after GHRH, arginine, and L-dopa administration in MD patients is not due to somatotroph deficiency, since the GH response to hypoglycemia is well preserved; and 2) insulin-induced hypoglycemia may stimulate GH release at least in part via inhibition of somatostatin release.

  14. Growth hormone (GH) activity is associated with increased serum oestradiol and reduced Anti-Müllerian Hormone in healthy male volunteers treated with GH and a GH antagonist

    Andreassen, M; Frystyk, Jan; Faber, J;


    Growth hormone (GH) and insulin-like growth factor I (IGF-I) receptors are present on pituitary gonadotrophs and on testicular Leydig and Sertoli cells. Thus, the GH/IGF-I system may modulate the pituitary-gonadal axis in males. This is a randomized cross-over study. Eight healthy male volunteers...... (mean age 35, range 29-46 years) were treated with GH for 3 weeks (1st week 0.01, 2nd week 0.02, 3rd week 0.03 mg/day/kg) or a GH receptor antagonist (Pegvisomant) (1st week 10, last 2 weeks 15 mg/day), separated by 8 weeks of washout. Before and after the two treatment periods, concentrations...... of luteinizing hormone (LH), follicle-stimulating hormone, testosterone, oestradiol, sex hormone-binding globulin, inhibin B and Anti-Müllerian Hormone (AMH) were measured. During GH treatment, IGF-I increased [(median (IQR)] 166 (162-235) vs. 702 (572-875) μg/L, p

  15. Continuation of growth hormone (GH) therapy in GH-deficient patients during transition from childhood to adulthood

    Nørrelund, Helene; Vahl, N; Juul, A


    fat and increased fat-free mass [M-value (mg/kg x min), 5.1 +/- 0.7 (placebo) vs. 3.4 +/- 1.0 (open), P = 0.09]. In the group randomized to continued GH treatment almost all hormonal and metabolic parameters remained unchanged during the study. In conclusion, 1) discontinuation of GH therapy for 1 yr...... in adolescent patients induces fat accumulation without compromising insulin sensitivity; and 2) the beneficial effects of continued GH treatment on body composition in terms of decrease in fat mass and increase in fat-free mass does not fully balance the direct insulin antagonistic effects....


    张海燕; 张士宏; 程明


    针对GH4169合金的Delta工艺,通过950℃高温拉伸实验研究了δ相对GH4169合金的高温拉伸变形行为的影响.结果表明:初始δ相含量为8.21%的GH4169合金的拉伸应力-应变曲线为典型的弹性-均匀塑性型;且在均匀塑性变形阶段表现为2个不同的变形阶段,其中第1阶段的加工硬化指数n为0.494,大于第2阶段的加工硬化指数0.101;其拉伸断裂机制为延性断裂的微孔聚集型断裂机制,其中δ相和碳化物是变形断裂中微孔形成的核心,因此δ相的存在使得合金的高温塑性降低,在GH4169合金的Delta工艺中必须控制δ相的析出含量.%GH4169 alloy is an important material used for aviation and aerospace engines because of its excellent mechanical properties in the temperature range from -253 ℃ to 650 ℃. In order to improve the safety and reliability of engines, it is crucial to obtain the forging with a uniform and fine microstructure. Generally, the forgings with large size and complex shape, such as turbine disks and engine shafts, are manufactured by multi-stage hot working processes. In addition, the microstructure of the alloy is sensitive to the hot deformation parameters. Therefore, the defects of coarse grain and duplex grain always appear in the forgings. As the S phase in the alloy can control grain growth through the strong pinning effect, the Delta process (DP) has been developed, which uses an intentional S phase precipitation cycle and subsequent thermomechanical processing to produce uniform fine grain billet and bar stock. In this work, for the DP of GH4169 alloy, the effect of 5 phase on the tensile deformation behavior of GH4169 alloy at high temperature was studied by the tensile tests at 950 ℃. The result indicated that the tensile stress-strain curve of the GH4169 alloy with 8.21% pre-precipitated S phase was the elastic-uniform plastic curve, and there were two different deformation processes during the uniform plastic

  17. Demographic factors influencing the GH system: Implications for the detection of GH doping in sport.

    Nelson, Anne E; Ho, Ken K Y


    Application of methods for detecting GH doping depend on being able to discriminate between abnormal levels due to doping and normal physiological levels of circulating proteins that change in response to exogenous administration. Constituents of the IGF and collagen systems have been shown to be promising markers of GH abuse. Their ultimate utility, however, depends on identification of the factors that regulate their concentrations in blood. Among these are demographic factors that are known to influence these markers in the general population. In a large cross-sectional study of the GH-responsive markers in over 1000 elite athletes from 12 countries representing 4 major ethnic groups and 10 sport types, we have shown that there is a significant negative correlation between age and all the IGF and collagen markers we studied, with a rapid decrease in early adolescence. Age was the major contribution to the variability, equivalent to >80% of the attributable variation in IGF-I and the collagen markers. The IGF axis markers were all significantly higher in women, and the collagen markers significantly higher in men, however, the contribution of gender was smaller than that of age, except for IGFBP-3 and ALS. BMI had a minor contribution to variability of the GH-responsive markers. After adjustment for the confounding influences of age, gender and BMI, the effect of ethnicity in elite athletes was trivial except for IGFBP-3 and ALS, which were both lower in Africans and higher in Caucasians. Compared to age and gender, the contribution of sport type was also modest. Our findings on the influence of age, gender, BMI and sport type have also been confirmed in a study of mostly Caucasian elite athletes in the post-competition setting. In conclusion, age and gender are the major determinants of variability for IGF-I and the collagen markers, whereas ethnicity and sport type have a minor influence. Therefore, a test based on IGF-I and the collagen markers must take age

  18. Endurance training and GH administration in elderly women

    Lange, K H; Lorentsen, J; Isaksson, F;


    In the present study, the effect of endurance training alone and endurance training combined with recombinant human growth hormone (rhGH) administration on subcutaneous abdominal adipose tissue lipolysis was investigated. Sixteen healthy women [age 75 +/- 2 yr (mean +/- SE)] underwent a 12-wk...... endurance training program on a cycle ergometer. rhGH was administered in a randomized, double-blinded, placebo-controlled design in addition to the training program. Subcutaneous abdominal adipose tissue lipolysis was estimated by means of microdialysis combined with measurements of subcutaneous abdominal...... and after completion of the training program. Similarly, no effect on subcutaneous abdominal adipose tissue lipolysis was observed when combining endurance training with rhGH administration. However, in both the placebo and the GH groups, fat oxidation was significantly increased during exercise performed...

  19. GH-producing mammary tumors in two dogs with acromegaly.

    Murai, Atsuko; Nishii, Naohito; Morita, Takehito; Yuki, Masashi


    Two intact female dogs were admitted for growing mammary tumors. They had symptoms of acromegaly including weight gain, enlargement of the head, excessive skin folds, and inspiratory stridor. Serum concentrations of growth hormone (GH), insulin-like growth factor-I (IGF-I), and insulin were elevated in the two cases. From these findings, both dogs were diagnosed with acromegaly. In case 1, the GH, IGF-I, and insulin levels subsided after removal of the focal benign mammary tumors and ovariohysterectomy. In case 2, those levels subsided after removal of only focal mammary carcinoma. In both cases, immunohistochemical investigations for GH were positive in the mammary tumor cells but not in the normal mammary glands. We concluded that GH-producing mammary tumors caused the present acromegaly.

  20. Polyamine and its metabolite H2O2 play a key role in the conversion of embryogenic callus into somatic embryos in upland cotton (Gossypium hirsutum L.

    Wen-Han eCheng


    Full Text Available The objective of this study was to increase understanding about the mechanism by which polyamines (PAs promote the conversion of embryogenic calli (EC into somatic embryos in cotton (Gossypium hirsutum L.. We measured the levels of endogenous PAs and H2O2, quantified the expression levels of genes involved in the PAs pathway at various stages of cotton somatic embryogenesis (SE, and investigated the effects of exogenous PAs and H2O2 on differentiation and development of embryogenic calli. Putrescine (Put, spermidine (Spd and spermine (Spm significantly increased from the EC stage to the early phase of embryo differentiation. The levels of Put then decreased until the somatic embryo stage whereas Spd and Spm remained nearly the same. The expression profiles of GhADC genes were consistent with changes in Put during cotton SE. The H2O2 concentrations began to increase significantly at the EC stage, during which time both GhPAO1 and GhPAO4 expressions were highest and PAO activity was significantly increased. Exogenous Put, Spd, Spm and H2O2 not only enhanced embryogenic callus growth and embryo formation, but also alleviated the effects of D-arginine and 1, 8-diamino-octane, which are inhibitors of polyamine synthesis and PAO activity. Overall, the results suggest that both PAs and their metabolic product H2O2 are essential for the conversion of EC into somatic embryos in cotton.

  1. GH4169合金研制进展%Progress in GH4169 Alloy Development

    杜金辉; 吕旭东; 邓群; 庄景云


    As a result of higher high temperature strength, excellent rupture stress, creep and fatigue properties, as well as good processing and welding performance, GH4169 alloy has been widely used in aerospace, petrochemical and other fields. With continuous improvement on performance of aeronautical and astronautical engines, some higher requirements were put forward to the key material GH4169 Such as temperature bearing capability, rupture stress and creep properties as well as fatigue resistant performance were improved to meet the demands of high performance, high reliability and long service life of the advanced aeroengines. The achievement of basic research and development of industrial manufacture technologies were systematically expounded from aspects of alloy modification, optimization of melting process, improvement of hot deformation technology for the past fifty years in this paper. Expounded contents include: development of alloying principle of modified alloy with higher temperature bearing capability for improving the thermal stability; triple melting technology for the preparation of large sizd clean ingot without segregation, promotion of hot processing technology of press forging and radial forging combination for the preparation of fine grained bar; new progress of hot die forging and isothermal forging for the realization of near net forming.%GH4169合金具有较高的高温强度,优异的持久、蠕变和疲劳性能,同时具备良好的加工和焊接性能,广泛用于航空、航天、石化等领域。随着航空、航天发动机性能的不断提高,对发动机关键用材GH4169在承温能力、持久蠕变性能和抗疲劳性能提出了更高要求,以满足先进航空发动机高性能、高可靠性、长寿命的需求。从合金改型、冶炼工艺优化、热加工技术提升等方面,系统论述了GH4169合金近50年基础研究成果及工程制备技术的进展。内容包括基于提高热稳定性

  2. Histology of skeletal muscle in adults with GH deficiency: comparison with normal muscle and response to GH treatment.

    Cuneo, R C; Salomon, F; Wiles, C M; Round, J M; Jones, D; Hesp, R; Sönksen, P H


    The histology of needle biopsy specimens of skeletal muscle from the vastus lateralis was quantitatively assessed in a group of adults with growth hormone (GH) deficiency, most of whom had hypopituitarism treated with conventional pituitary hormone replacement. The mean age of the 21 patients (16 males and 5 females) was 39 +/- 2 (SEM). Comparisons were made with age- and sex-matched controls following six months double-blind, placebo-controlled treatment with recombinant human GH (rhGH) in the GH-deficient patients. Before treatment, needle muscle biopsies from patients with GH deficiency showed mean type I and II fibre areas of 5,153 +/- 273 and 4,828 +/- 312 microns 2 respectively, which did not differ from the controls (4,482 +/- 306 and 4,699 +/- 310 microns 2). Percentages of type I fibres were similar in the two groups (47.2 +/- 2.5% in GH deficiency and 45.3 +/- 2.2% in controls). No difference in the variability of type I or II fibre areas was demonstrated between the groups. Correlations between the relative contribution to total fibre area by type I fibres (mean fibre area x percent) and maximal oxygen uptake (p = 0.006), and between type II fibres and quadriceps force (p = 0.035) were noted in GH-deficient adults before treatment. Following rhGH treatment, no change was noted in mean fibre areas, variability of fibre areas, or percentage of either fibre type.(ABSTRACT TRUNCATED AT 250 WORDS)



    Objective To evaluate the bioequivalence between recombinant human growth hormone ( rhGH) for reconstitution, and two dosages of liquid formulation of rhGH [ (15IU)5mg or ( 30IU) l0mg per 3ml].Methods The study drugs were tested in a randomized, single-blind and three-period crossover studies in 24 healthy male subjects. The three drugs were administered by subcutaneous injection at a dose of 0. 2IU/kg body weight. A continuous somatostatin infusion was given in order to suppress the secretion of endogenous GH. The venous blood samples were drawn at different time points to test the serum concentration of GH. The pharmacokinetic parameters were analyzed by statistical methods. Results 90% confidence intervals (CI) of AUC0-24h among three products were all within 80% -125% interval (103.4% -116. 5%, 105. 7% -119. 6% and 91.9% -103. 7%,respectively), and the CIs of Cmax among three products were all within 70%-143% interval ( 91.9%-114. 0%,103. 7%-127. 2% and 81.6%-97. 4%, respectively). There was no statisitical difference of tmax among all the three products. Conclusion These data demonstrate that there is bioequivalence between rhGH for reconstitution and two liquid formulations of rhGH.

  4. Recruiting of somatotroph cells after combined somatostatin, GHRH and growth hormone (GH) secretagogue stimulation in a study of pituitary GH reserve in prepuberal female rats

    Jiménez Reina, L.; García-Martínez, E.; Rojas, J.P.; Cañete, M.D.; G. Bernal; Cañete, R.


    Diagnostic confirmation of growth hormone (GH) deficiency in children and adults is based on stimulation tests designed to assess the pituitary reserve by measuring the amount of GH released into the bloodstream; however, the results obtained by this means cannot provide any direct indication of the amount of GH actually produced by pituitary somatotroph cells. The present paper sought to test the hypothesis that release of GH following administration of sp...

  5. Adult growth hormone (GH)-deficient patients demonstrate heterogeneity between childhood onset and adult onset before and during human GH treatment. Adult Growth Hormone Deficiency Study Group

    Attanasio, A F; Lamberts, S W; Matranga, A M


    The onset of adult GH deficiency may be during either adulthood (AO) or childhood (CO), but potential differences have not previously been examined. In this study the baseline and GH therapy (12.5 micrograms/kg per day) data from CO (n = 74; mean age 29 yr) and AO (n = 99; mean age 44 yr) GH-defi...

  6. The precalence of the metabolic syndrome is increades in patients with GH deficiency, irrespective of long-term substition with recombinant human GH

    Klaauw, A.A.; Biermasz, N.R.; Feskens, E.J.M.; Bos, M.B.; Smit, J.W.; Roelfsema, F.; Corssmit, E.P.; Pijl, H.; Romijn, J.A.; Pereira, A.M.


    Objectives: Many reports demonstrate improvements in cardiovascular risk factors during GH replacement (rhGH) in adult GH deficiency (GHD). However, it remains to be determined to what extent these changes translate into a reduction of increased cardiovascular morbidity and mortality. The aim of thi

  7. IGF-I bioactivity might reflect different aspects of quality of life than total IGF-I in gh-deficient patients during GH treatment

    A.J. Varewijck (Aimee); S.W.J. Lamberts (Steven); S.J.C.M.M. Neggers (Bas); L.J. Hofland (Leo); J.A.M.J.L. Janssen (Joseph)


    textabstractContext: No relationship has been found between improvement in quality of life (QOL) and total IGF-I during GH therapy. Aim: Our aim was to investigate the relationship between IGF-I bioactivity and QOL in GH-deficient (GHD) patients receiving GH for 12 months. Methods: Of 106 GHD patien

  8. Partial biochemical and biological characterization of purified chicken growth hormone (cGH). Isolation of cGH charge variants and evidence that cGH is phosphorylated.

    Arámburo, C; Carranza, M; Sanchez, R; Perera, G


    Chicken growth hormone (cGH) was purified from frozen pituitary glands obtained from recently sacrificed broilers. Glands were homogenized in a protease inhibitor solution (0.5 mM PMSF, 50 KIU/ml aprotinin, pH 7.2); extract was taken to pH 9.0 with calcium hydroxide and the supernatant was differentially precipitated with 20% (fraction A) and 50% (fraction B) ammonium sulfate. cGH (fraction B-DE-1) was obtained in pure form from fraction B after DEAE-cellulose chromatography at pH 8.6, with a yield of 2.9 mg/g tissue. Three charge variants of cGH (Rf = 0.23, 0.30, and 0.35) could be isolated by electroelution after semipreparative nondenaturing polyacrylamide gel electrophoresis of fraction B-DE-1. These charge variants showed the same apparent molecular weight (26,300 Da) by sodium dodecyl sulfate polyacrylamide gel electrophoresis under reducing conditions. Isoelectric focusing of fraction B-DE-1 revealed two major components (pI = 7.2 and 7.4) and four minor bands (pI = 6.2, 6.7, 7.1, and 7.5). It was found that fraction B-DE-1 contained a significant amount of esterified phosphate (1 nmol PO4/3.5 nmol protein) similar to that reported previously for ovine GH. The functional integrity of the cGH obtained here was characterized by two heterologous and one homologous bioassays. High activity was shown by fraction B-DE-1 in the tibia assay (1.76 UI/mg) and in the liver ornithine decarboxylase assay (sixfold over control), both made in hypophysectomized rats; and it also stimulated lipolysis (138 and 215% at 10 and 100 ng/ml, respectively) on chicken abdominal adipose tissue explants.

  9. Cloning and characterization of the first GH10 and GH11 xylanases from Rhizopus oryzae.

    Xiao, Zhizhuang; Grosse, Stephan; Bergeron, Hélène; Lau, Peter C K


    The only available genome sequence for Rhizopus oryzae strain 99-880 was annotated to not encode any β-1,4-endoxylanase encoding genes of the glycoside hydrolase (GH) family 10 or 11. Here, we report the identification and cloning of two such members in R. oryzae strain NRRL 29086. Strain 29086 was one of several selected fungi grown on wheat or triticale bran and screened for xylanase activity among other hydrolytic actions. Its high activity (138 U/ml) in the culture supernatant led to the identification of two activity-stained proteins, designated Xyn-1 and Xyn-2 of respective molecular masses 32,000 and 22,000. These proteins were purified to electrophoretic homogeneity and characterized. The specific activities of Xyn-1 and Xyn-2 towards birchwood xylan were 605 and 7,710 U/mg, respectively. Kinetic data showed that the lower molecular weight Xyn-2 had a higher affinity (K m=3.2 ± 0.2 g/l) towards birchwood xylan than Xyn-1 by about 4-fold. The melting temperature (T m) of the two proteins, estimated to be in the range of 49.5-53.7 °C indicated that they are rather thermostable proteins. N-terminal and internal peptide sequences were obtained by chemical digestion of the purified xylanases to facilitate cloning, expression in Escherichia coli, and sequencing of the respective gene. The cloned Rhizopus xylanases were used to demonstrate release of xylose from flax shives-derived hemicellulose as model feedstock. Overall, this study expands the catalytic toolbox of GH10 and 11 family proteins that have applications in various industrial and bioproducts settings.

  10. Growth hormone dose regimens in adult GH deficiency: effects on biochemical growth markers and metabolic parameters

    Møller, Jens; Jørgensen, Jens Otto Lunde; Laursen, Torben;


    Abstract OBJECTIVE: We examined the effects of different doses of GH on insulin-like growth factor I (IGF-I), IGF binding protein 3 (IGFBP-3), body composition, energy expenditure, and various metabolites in GH deficient adults, in order to approach a metabolically appropriate GH dosage in young GH...... deficient adults. DESIGN: Ten GH deficient patients (age 21-43) were studied after 4 weeks without GH followed by three consecutive 4-week periods, where the patients received in a fixed order GH 1, 2 and 4 IU/m2 s.c. per day. At the end of each period the patients were hospitalized for a 24-hour...... examination. RESULTS: Mean 24-hour levels of GH (mIU/l) were 2.7 +/- 0.3 (0 GH), 7.2 +/- 0.9 (1), 10.8 +/- 1.5 (2) and 18.9 +/- 2.7 (4 IU/m2) (mean +/- SEM) (P

  11. [Suppression by dopamine of GH release induced by GRF in a case of acromegaly].

    Matsubara, M; Odagaki, E; Morioka, T


    Inhibition of plasma GH by dopaminergic agonists is one of the characteristics of the GH secretion in acromegaly. GRF is known to stimulate GH secretion in most patients with acromegaly. In order to elucidate the relationship between GRF and dopamine in regulating the secretion of GH in this disease, we examined plasma GH responses to dopamine (DA) infusion (4 micrograms/kg/min), GRF injection (100 micrograms i.v.), sulpiride (SP) injection (200 mg i.v.), a DA blocker, DA plus GRF and SP plus GRF in a 51-year-old male patient with acromegaly. Plasma GH was reduced to 14% of the initial level by iv infusion of DA, and was elevated to 158% by iv injection of GRF. No considerable change was observed in plasma GH by iv infusion of SP (114% of the initial level). GH release induced by GRF was remarkably reduced by simultaneous administration of DA (28% of the initial level), whereas SP administration did not affect GRF-induced GH release (154%). The marked reduction of GH release after DA plus GRF seems to suggest that the effect of DA on the GH regulation is stronger than that of GRF in this acromegalic patient. It is suggested also that endogenous DA may not play an inhibitory role in GH secretion in this case since DA blockade by SP did not raise basal GH levels and the GH response to GRF.

  12. Energy homeostasis targets chromosomal reconfiguration of the human GH1 locus.

    Vakili, Hana; Jin, Yan; Cattini, Peter A


    Levels of pituitary growth hormone (GH), a metabolic homeostatic factor with strong lipolytic activity, are decreased in obese individuals. GH declines prior to the onset of weight gain in response to excess caloric intake and hyperinsulinemia; however, the mechanism by which GH is reduced is not clear. We used transgenic mice expressing the human GH (hGH) gene, GH1, to assess the effect of high caloric intake on expression as well as the local chromosome structure of the intact GH1 locus. Animals exposed to 3 days of high caloric intake exhibited hyperinsulinemia without hyperglycemia and a decrease in both hGH synthesis and secretion, but no difference in endogenous production of murine GH. Efficient GH1 expression requires a long-range intrachromosomal interaction between remote enhancer sequences and the proximal promoter region through "looping" of intervening chromatin. High caloric intake disrupted this interaction and decreased both histone H3/H4 hyperacetylation and RNA polymerase II occupancy at the GH1 promoter. Incorporation of physical activity muted the effects of excess caloric intake on insulin levels, GH1 promoter hyperacetylation, chromosomal architecture, and expression. These results indicate that energy homeostasis alters postnatal hGH synthesis through dynamic changes in the 3-dimensional chromatin structure of the GH1 locus, including structures required for cell type specificity during development.

  13. Stability of globular proteins in H2O and D2O

    Efimova, Y. M.; Haemers, S.; Wierczinski, B.; Norde, W.; van Well, A. A.


    In several experimental techniques D2O rather then H2O is often used as a solvent for proteins. Concerning the influence of the solvent on the stability of the proteins, contradicting results have been reported in literature. In this paper the influence of H2O-D2O solvent substitution on the stabili

  14. Stability of globular proteins in H2O and in D2O

    Efimova, Y.M.; Haemers, S.; Wierczinsky, B.; Norde, W.; Well, van A.A.


    In several experimental techniques D2O rather then H2O is often used as a solvent for proteins. Concerning the influence of the solvent on the stability of the proteins, contradicting results have been reported in literature. In this paper the influence of H2O-D2O solvent substitution on the

  15. Stability of globular proteins in H2O and D2O

    Efimova, Y. M.; Haemers, S.; Wierczinski, B.; Norde, W.; van Well, A. A.


    In several experimental techniques D2O rather then H2O is often used as a solvent for proteins. Concerning the influence of the solvent on the stability of the proteins, contradicting results have been reported in literature. In this paper the influence of H2O-D2O solvent substitution on the

  16. Dissolution mechanism of Al2O3 in refining slags containing Ce2O3

    Wang L.J.


    Full Text Available In the present work, the rate of dissolution of Al2O3 rod in CaO-SiO2-Al2O3 and CaO-SiO2-Al2O3-Ce2O3 slags were carried out in the temperature range of 1793 K (1520ºC - 1853 K (1580ºC under static conditions. The cross section of the rod and the boundary layers were identified and analyzed by SEM-EDS. The dissolution of Al2O3 was favored with the increasing CaO/Al2O3 ratio, elevating temperatures as well as the addition of Ce2O3. An intermediate product 3CaO5Al2O3Ce2O3 was detected. The mechanism of dissolution of Al2O3 in the Ce2O3 containing slag were also proposed as three steps involved: 1 the formation of calcium aluminates CaO•Al2O3 at the interface 2 the formation of 3CaO5Al2O3Ce2O3 as the reaction progresses; and 3 the dissolution of 3CaO5Al2O3Ce2O3 into the slag.

  17. Regulation of brain mitochondrial H2O2 production by membrane potential and NAD(P)H redox state.

    Starkov, Anatoly A; Fiskum, Gary


    Mitochondrial production of reactive oxygen species (ROS) at Complex I of the electron transport chain is implicated in the etiology of neural cell death in acute and chronic neurodegenerative disorders. However, little is known regarding the regulation of mitochondrial ROS production by NADH-linked respiratory substrates under physiologically realistic conditions in the absence of respiratory chain inhibitors. This study used Amplex Red fluorescence measurements of H2O2 to test the hypothesis that ROS production by isolated brain mitochondria is regulated by membrane potential (DeltaPsi) and NAD(P)H redox state. DeltaPsi was monitored by following the medium concentration of the lipophilic cation tetraphenylphosphonium with a selective electrode. NAD(P)H autofluorescence was used to monitor NAD(P)H redox state. While the rate of H2O2 production was closely related to DeltaPsi and the level of NAD(P)H reduction at high values of DeltaPsi, 30% of the maximal rate of H2O2 formation was still observed in the presence of uncoupler (p-trifluoromethoxycarbonylcyanide phenylhydrazone) concentrations that provided for maximum depolarization of DeltaPsi and oxidation of NAD(P)H. Our findings indicate that ROS production by mitochondria oxidizing physiological NADH-dependent substrates is regulated by DeltaPsi and by the NAD(P)H redox state over ranges consistent with those that exist at different levels of cellular energy demand.

  18. Increased Secretion of Endogenous GH after Treatment with an Intranasal GH-releasing Peptide-2 Spray Does Not Promote Growth in Short Children with GH Deficiency.

    Tanaka, Toshiaki; Hasegawa, Yukihiro; Yokoya, Susumu; Nishi, Yoshikazu


    We investigated whether treatment with an intranasal GH-releasing peptide (GHRP)-2 spray, which acts as a potent GH secretagogue that stimulates endogenous GH secretion, promotes growth in patients with GH deficiency (GHD). This study involved 126 prepubertal short children (81 males, 45 females) with a height SD score of -2 SD or less, who had been diagnosed as having GHD based on GH stimulation tests, and in whom the serum GH concentrations increased up to 9 ng/ml after preliminary administration of an intranasal GHRP-2 spray. The subjects included in this study were divided into 3 groups by use of a double-blind method; that is 44 were placed into the placebo group (P group: 30 males, 14 females), 41 were placed into the GHRP-2 low dose group (L group: 25 males, 16 females), and 41 were placed into the GHRP-2 high dose group (H group: 26 males, 15 females). Those with a body wt of less than 20 kg were administered a placebo (P group), 50 μg of GHRP-2 (L group) or 100 μg of GHRP-2 (H group), and those with a body wt of 20 kg or more were administered a placebo (P group), 100 µg of GHRP-2 (L group) or 200 µg of GHRP-2 (H group) twice daily (morning and evening) for 48 continuous wk. Age and height SD scores at baseline were not significantly different among the three groups: 7.5 yr old and -2.26 SD in the P group, 7.3 yr old and -2.38 SD in the L group, and 7.5 yr old and -2.27 SD in the H group. Of the 126 subjects, 44, 40 and 40 subjects in the P, L and H groups, respectively, completed the 48 continuous wk of treatment. The changes in the mean height SD scores (mean growth rate) after 48 wk of treatment in the P, L and H groups were 0.07 SD, 0.03 SD, and 0.02 SD, respectively, and thus no significant differences was observed among the 3 groups. Also no significant changes in blood IGF-I levels at baseline or after 48 wk of treatment were observed among the 3 groups. This study revealed that in patients with GHD, an increase in endogenous GH secretion as a

  19. Enhancement in electrical conductivity of Li2O : B2O3 : V2O5 glasses

    R S Gedam; V K Deshpande


    The study of electrical conductivity of 30Li2O : (70 – ) B2O3 : V2O5 glass samples has been carried out. The results have been explained by dividing the temperature range into two regions. In region I, conductivity shows Arrhenius behaviour for all the samples. The conductivity increases with addition of V2O5. The results have been explained in the light of Anderson and Stuart Model. In region II, an anomalous enhancement in the conductivity is observed for all the samples up to certain temperature beyond which the conductivity decreases. The enhancement in the conductivity in the annealed glass sample has been attributed to nanocrystallization.

  20. Broaching Performance of Superalloy GH4169 Based on FEM

    Xiangwei Kong; Bin Li; Zhibo Jin; Wenran Geng


    The nickel-based superalloy GH4169 is an important material for high temperature applications in the aerospace industry. However, due to its poor machinability, GH4169 is hard to be cut and generates saw-tooth chips during high speed machining, which could significantly affect the dynamic cutting force, cutting temperature fluctuation, tool life, and the surface integrity of the parts. In this paper, the saw-tooth chip formation mechanism of superalloy GH4169 was investigated by the elasto-viscoplastic finite element method (FEM). Using the finite element software of ABAQUS/Explicit, the deformation of the part during high speed machining was simulated. The effective plastic strain, the temperature field, the stress distribution, and the cutting force were analyzed to determine the influence of the cutting parameters on the saw-tooth chip formation. The study on broaching performance has great effect on selecting suitable machining parameters and improving tool life.

  1. Bioavailability and bioactivity of three different doses of nasal growth hormone (GH) administered to GH-deficient patients

    Laursen, Torben; Grandjean, Birgitte; Jørgensen, Jens Otto Lunde;


    Abstract The current mode of growth hormone (GH) replacement therapy is daily subcutaneous (s.c.) injections given in the evening. This schedule is unable to mimic the endogenous pulsatile pattern of GH secretion, which might be of importance for the induction of growth and other GH actions....... Intravenous administration produced a short-lived serum GH peak value of 128.12 +/- 6.71 micrograms/l. Peak levels were 13.98 +/- 1.63 micrograms/l after s.c. injection and 3.26 +/- 0.38, 7.07 +/- 0.80 and 8.37 +/- 1.31 micrograms/l, respectively, after the three nasal doses. The peak values of the 0....... The absolute bioavailability of GH following s.c. relative to i.v. administration was 49.5%. The bioavailabilities of the nasal doses were: 7.8% (0.05 IU). 8.9% (0.10 IU) and 3.8% (0.20 IU). Serum insulin-like growth factor I (IGF-I) levels increased significantly after s.c. administration only. Mean levels...

  2. Growth hormone (GH)-independent dimerization of GH receptor by a leucine zipper results in constitutive activation

    Behncken, S N; Billestrup, Nils; Brown, R;


    Growth hormone initiates signaling by inducing homodimerization of two GH receptors. Here, we have sought to determine whether constitutively active receptor can be created in the absence of the extracellular domain by substituting it with high affinity leucine zippers to create dimers of the gro......Growth hormone initiates signaling by inducing homodimerization of two GH receptors. Here, we have sought to determine whether constitutively active receptor can be created in the absence of the extracellular domain by substituting it with high affinity leucine zippers to create dimers...... proliferation after interleukin 3 withdrawal at a rate equal to maximally stimulated wild type GHR-expressing cells. Activation of STAT 5b was also observed in Fos-Jun-GHR-expressing cells at a level equal to that in chronically GH-treated GHR-expressing cells. Thus, forced dimerization of the transmembrane...... and cytoplasmic domains of the GHR in the absence of the extracellular domain can lead to the constitutive activation of known GH signaling end points, supporting the view that proximity of Janus kinase 2 (JAK2) kinases is the essential element in signaling. Such constitutively active GH receptors may have...

  3. Identification and Characterization of GH Receptor and Serum GH-binding Protein in Chinese Sturgeon (Acipenser sinensis)

    Zhi-Yong LIAO; Shang-Quan ZHU


    Chinese sturgeon, a kind of cartilage ganoid, has a history of over one billion years and it is called the living fossil of aquatic biology since it keeps some evolutionary trace. Here, we characterized the growth hormone receptor (GHR) and serum growth hormone binding protein (GHBP) of Chinese sturgeon. It was shown that GHR was expressed in various tissues, mainly in hepatic, kidney and intestine tissues. GHR on the hepatic membrane has high and specific affinity for bream GH (brGH) and Scatchard analysis of the binding data showed a single class of high affinity binding site with an association constant Ka of 3.1×109 M-1. A specific band around 94 kD was detected by SDS-PAGE in cross-linking studies of membrane receptors. After incubation of Chinese sturgeon serum with 125I-brGH, a 125I-brGH-GHBP complex was identified by Sephadex G-75, indicating that in the serum exists GHBP specially binding to brGH.

  4. Auxological criteria for the diagnosis of GH-dependent short stature and prescription of rGH: problems and pitfalls

    Giulio Gilli


    Full Text Available Recombinant growth hormone (rGH administration is a cornerstone in the treatment of short stature secondary to GH deficit. Since its introduction in the 80s, the population of short patients with an indication to rGH therapy has clearly broadened, probably because of increased awareness by patients and physicians. Since rGH therapy is demanding for patients and expensive, the Italian National Health Service, like other third payers and regulatory authorities, regulates its prescription according to criteria listed in the Nota AIFA 39. This paper illustrates pitfalls and difficulties paediatricians may encounter when assessing short stature patients in order to decide upon the opportunity and possibility to initiate rGH therapy through the exposition of four emblematic, though hypothetical, clinical histories. In the discussion, the Authors highlight some of the most critical points in the formulation of the Nota 39, among which are the lack of clear reference values, neglecting of parental height targets and therapeutic responses, as well as some omissions in methodology specifications.

  5. GH/IGF1 axis disturbances in the fibromyalgia syndrome: is there a rationale for GH treatment?

    Cuatrecasas, G; Alegre, C; Casanueva, F F


    Fibromyalgia Syndrome (FMS) is a frequent idiopathic condition in which patients experience intense pain in specific tender points, profound fatigue and sleep disturbances. Although pain had not account so far in growth hormone deficiency syndrome (GHD) description, symptoms of FMS are very similar; and there is strong evidence of decreased GH secretion at least in a subset of FMS patients. Is there an overlap of the two diseases? A systematic Medline/Embase search for preliminary proof-of-concept trials, but also larger placebo-controlled studies, have shown that GH replacement in low-IGF1 patients can significantly improve some symptoms of FMS and quality of life, suggesting a direct causal effect of GH deficiency. Despite the use of relatively high doses of GH in these patients, treatment seems to be well tolerated. Several mechanisms of action for GH in FMS relief have been suggested, including both central modulation of pain and peripheral musculo-tendinous effects, as already described in classic GHD.

  6. Delta hedging strategies comparison

    De Giovanni, Domenico; Ortobelli, S.; Rachev, S.T.


    In this paper we implement dynamic delta hedging strategies based on several option pricing models. We analyze different subordinated option pricing models and we examine delta hedging costs using ex-post daily prices of S&P 500. Furthermore, we compare the performance of each subordinated model ...

  7. The effects of growth hormone (GH) treatment on GH and insulin/IGF-1 signaling in long-lived Ames dwarf mice.

    Masternak, Michal M; Panici, Jacob A; Wang, Feiya; Wang, Zhihui; Spong, Adam


    The disruption of the growth hormone (GH) axis in mice promotes insulin sensitivity and is strongly correlated with extended longevity. Ames dwarf (Prop1(df), df/df) mice are GH, prolactin (PRL), and thyrotropin (TSH) deficient and live approximately 50% longer than their normal siblings. To investigate the effects of GH on insulin and GH signaling pathways, we subjected these dwarf mice to twice-daily GH injections (6 microg/g/d) starting at the age of 2 weeks and continuing for 6 weeks. This produced the expected activation of the GH signaling pathway and stimulated somatic growth of the Ames dwarf mice. However, concomitantly with increased growth and increased production of insulinlike growth factor-1, the GH treatment strongly inhibited the insulin signaling pathway by decreasing insulin sensitivity of the dwarf mice. This suggests that improving growth of these animals may negatively affect both their healthspan and longevity by causing insulin resistance.

  8. Dynamic evaluation of growth hormone (GH) and prolactin (hPRL) secretion in active acromegaly with high and low GH output.

    Tolis, G; Kovacs, L; Friesen, H; Martin, J B


    Ten patients with active acromegaly were studied. In 9 plasma GH levels failed to suppress after glucose (OGTT), in 8 an increase in serum GH occurred after thyrotropin releasing hormone (TRH). After L-Dopa, 4 patients showed no change in serum GH, 3 exhibited a decrease and in 3 an increase in serum hGH occurred. With a combined insulin (ITT) and arginine (ATT) test, 2 patients exhibited an increase in hGH, and in 6 no change occurred. Fasting serum GH concentration was less than 11 ng/ml in 5 patients. Basal prolactin (hPRL) levels were normal in all patients including two with galactorrhea. L-Dopa suppressed and TRH stimulated hPRL secretion in all, but the responses which were seen were subnormal. Hydrocortisone infusion in two acromegalics did not affect the prolactin induced increase after TRH but blunted the GH increase after TRH.

  9. Endurance training and GH administration in elderly women

    Lange, K H; Lorentsen, J; Isaksson, F


    adipose tissue blood flow (ATBF; (133)Xe washout). Whole body fat oxidation was estimated simultaneously by indirect calorimetry. Before and after completion of the training program, measurements were performed both at rest and during 60 min of continuous cycling at a workload corresponding to 60...... and after completion of the training program. Similarly, no effect on subcutaneous abdominal adipose tissue lipolysis was observed when combining endurance training with rhGH administration. However, in both the placebo and the GH groups, fat oxidation was significantly increased during exercise performed...

  10. Raman scattering of light in YBa2Cu3O(7-delta) single-phase ceramics

    Limonov, M.F.; Markov, IU.F.; Pollert, E.; Triska, A.


    Results of an experimental study of Raman spectra are reported for specimens of YBa/sub 2/Cu/sub 3/O(7-delta) ceramics (delta=0.37) produced by the sintering of Y/sub 2/O/sub 3/, CuO, and BaCO/sub 3/. The characteristics of the Raman spectra of the specimens are discussed, and it is shown that the specimens of superconducting ceramics investigated are characterized by high homogeneity, with no traces of the 'parasitic' Y/sub 2/O/sub 3/ and Y/sub 2/Cu/sub 2/O/sub 5/ phases. 7 references.

  11. Vortex Breakdown over Slender Delta Wings (Eclatement tourbillonnaire sur les ailes delta effil es)


    Velocity Component VB 21-33 A.4 Tangential Velocity Component WB 21-34 A.5 Axial Velocity Induced on the Centreline 21-34 A.6 Numerical...Three Dimensional Vortex Sheet Structure on Delta Wings,” AGARD-CP-438, October 1988. [59] Brandon, J.M. and Shah , G.H., “Effect of Large Amplitude...TR-AVT-080 5 - 25 403020100-10-20-30-40 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 dynamic Static ( σ=30°, ∆φ=33°, =0.14 )k φ° x VB 15c15c 403020100-10

  12. Horizontal Symmetries $\\Delta(150)$ and $\\Delta(600)$

    Lam, C S


    Using group theory of mixing to examine all finite subgroups of SU(3) with an order less than 512, we found recently that only the group $\\Delta(150)$ can give rise to a correct reactor angle $\\th_{13}$ of neutrino mixing without any free parameter. It predicts $\\sin^22\\th_{13}=0.11$ and a sub-maximal atmospheric angle with $\\sin^22\\th_{23}=0.94$, in good agreement with experiment. The solar angle $\\th_{12}$, the CP phase $\\d$, and the neutrino masses $m_i$ are left as free parameters. In this article we provide more details of this case, discuss possible gain and loss by introducing right-handed symmetries, and/or valons to construct dynamical models. A simple model is discussed where the solar angle agrees with experiment, and all its mixing parameters can be obtained from the group $\\Delta(600)$ by symmetry alone. The promotion of $\\Delta(150)$ to $\\Delta(600)$ is on the one hand analogous to the promotion of $S_3$ to $S_4$ in the presence of tribimaximal mixing, and on the other hand similar to the extens...

  13. Expression of lymphocyte-derived growth hormone (GH) and GH-releasing hormone receptors in aging rats.

    Weigent, Douglas A


    In the present study, we show that higher levels of lymphocyte GH are expressed in spleen cells from aging animals compared to young animals. Further, leukocytes from primary and secondary immune tissues and splenic T and B cells from aging rats all express higher levels of GHRH receptors compared to younger animals. Bone marrow and splenic T cells express the highest levels of GHRH receptor in aging animals. Spleen cells from aging animals showed no significant change in proliferation or GH induction after treatment with GHRH. Taken together, the data for the first time show alterations in GH synthesis and expression of the GHRH receptor on cells of the immune system that may play a role in the immune response in aging.

  14. Optimization on dielectric properties of Y2Ti2O7 ceramics with Bi2O3-Nd2O3-Nb2O5 co-doping

    DING Jiayu; WANG Zhefei; GONG Zhijie; XIAO Yuan; WANG Lixi; ZHANG Qitu


    The present work aimed to explore a kind of microwave dielectric materials with middle-permittivity,high Qf,near-zero τf,and lower sintering temperature.A series of Y2Ti2O7 microwave dielectric ceramics were synthesized by conventional solid-state method.For improving the dielectric properties of Y2Ti2O7 systerm,Bi2O3,Nd2O3 and Nb2O5 were added and their effects on phase composition,microstructure,and dielectric properties at microwave frequencies were investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM).The queuing score method for multi-target orthogonal design was used to obtain the optimum prescription.The results showed that the Y2Ti2O7 ceramics with 8 wt.% Bi2O3 and 1 mol.% Nd2O3-Nb2O5 were well sintered at 1350 ℃,exhibiting excellent dielectric characteristics,i.e.εr≈76,Qf≈18980 GHz,τf=+25.5 ppm/℃.

  15. Internalization and synaptogenic effect of GH in retinal ganglion cells (RGCs).

    Fleming, Thomas; Martínez-Moreno, Carlos G; Mora, Janeth; Aizouki, Miray; Luna, Maricela; Arámburo, Carlos; Harvey, Steve


    In the chicken embryo, GH gene expression occurs in the neural retina and retinal GH promotes cell survival and induces axonal growth of retinal ganglion cells. Neuroretinal GH is therefore of functional importance before the appearance of somatotrophs and the onset of pituitary GH secretion to the peripheral plasma (at ED15-17). Endocrine actions of pituitary GH in the development and function of the chicken embryo eye are, however, unknown. This possibility has therefore been investigated in ED15 embryos and using the quail neuroretinal derived cell line (QNR/D). During this research, we studied for the first time, the coexistence of exogenous (endocrine) and local GH (autocrine/paracrine) in retinal ganglion cells (RGCs). In ovo systemic injections of Cy3-labeled GH demonstrated that GH in the embryo bloodstream was translocated into the neural retina and internalized into RGC's. Pituitary GH may therefore be functionally involved in retinal development during late embryogenesis. Cy3-labelled GH was similarly internalized into QNR/D cells after its addition into incubation media. The uptake of exogenous GH was by a receptor-mediated mechanism and maximal after 30-60min. The exogenous (endocrine) GH induced STAT5 phosphorylation and increased growth associated protein 43 (GAP43) and SNAP-25 immunoreactivity. Ex ovo intravitreal injections of Cy3-GH in ED12 embryos resulted in GH internalization and STAT5 activation. Interestingly, the CY3-labeled GH accumulated in perinuclear regions of the QNR/D cells, but was not found in the cytoplasm of neurite outgrowths, in which endogenous retinal GH is located. This suggests that exogenous (endocrine) and local (autocrine/paracrine) GH are both involved in retinal function in late embryogenesis but they co-exist in separate intracellular compartments within retinal ganglion cells.

  16. Effect of GH/IGF-1 on Bone Metabolism and Osteoporsosis

    Vittorio Locatelli


    Full Text Available Background. Growth hormone (GH and insulin-like growth factor (IGF-1 are fundamental in skeletal growth during puberty and bone health throughout life. GH increases tissue formation by acting directly and indirectly on target cells; IGF-1 is a critical mediator of bone growth. Clinical studies reporting the use of GH and IGF-1 in osteoporosis and fracture healing are outlined. Methods. A Pubmed search revealed 39 clinical studies reporting the effects of GH and IGF-1 administration on bone metabolism in osteopenic and osteoporotic human subjects and on bone healing in operated patients with normal GH secretion. Eighteen clinical studies considered the effect with GH treatment, fourteen studies reported the clinical effects with IGF-1 administration, and seven related to the GH/IGF-1 effect on bone healing. Results. Both GH and IGF-1 administration significantly increased bone resorption and bone formation in the most studies. GH/IGF-1 administration in patients with hip or tibial fractures resulted in increased bone healing, rapid clinical improvements. Some conflicting results were evidenced. Conclusions. GH and IGF-1 therapy has a significant anabolic effect. GH administration for the treatment of osteoporosis and bone fractures may greatly improve clinical outcome. GH interacts with sex steroids in the anabolic process. GH resistance process is considered.

  17. Photolysis of H2O-H2O2 Mixtures: The Destruction of H2O2

    Loeffler, M. J.; Fama, M.; Baragiola, R. A.; Carlson, R. W.


    We present laboratory results on the loss of H2O2 in solid H2O + H2O2 mixtures at temperatures between 21 and 145 K initiated by UV photolysis (193 nm). Using infrared spectroscopy and microbalance gravimetry, we measured the decrease of the 3.5 micrometer infrared absorption band during UV irradiation and obtained a photodestruction cross section that varies with temperature, being lowest at 70 K. We use our results, along with our previously measured H2O2 production rates via ionizing radiation and ion energy fluxes from the spacecraft to compare H2O2 creation and destruction at icy satellites by ions from their planetary magnetosphere and from solar UV photons. We conclude that, in many cases, H2O2 is not observed on icy satellite surfaces because the H2O2 photodestruction rate is much higher than the production rate via energetic particles, effectively keeping the H2O2 infrared signature at or below the noise level.

  18. Spectroscopic studies of Bi 2O 3-Li 2O-ZnO-B 2O 3 glasses

    Bale, Shashidhar; Rao, N. Srinivasa; Rahman, Syed


    Raman and infrared spectroscopies have been employed to investigate the xBi 2O 3-(65 - x)Li 2O-20ZnO-15B 2O 3 glasses in order to obtain information about the competitive role of Bi 2O 3 and B 2O 3 in the formation of glass network. IR and Raman spectra show that these glasses are made up of [BiO 3] pyramidal and [BiO 6] octahedral units. The formation of Zn 2+ in tetrahedral coordination was observed. The average electronic polarizability of the oxide ion ( α), optical basicity ( Λ), and Yamashita-Kurosawa's interaction parameter ( A) were also examined.

  19. The role of GH receptor tyrosine phosphorylation in Stat5 activation

    Hansen, J A; Hansen, L H; Wang, X;


    Stimulation of GH receptors leads to rapid activation of Jak2 kinase and subsequent tyrosine phosphorylation of the GH receptor. Three specific tyrosines located in the C-terminal domain of the GH receptor have been identified as being involved in GH-stimulated transcription of the Spi 2.1 promoter....... Mutated GH receptors lacking all but one of these three tyrosines are able to mediate a transcriptional response when transiently transfected into CHO cells together with a Spi 2.1 promoter/luciferase construct. Similarly, these GH receptors were found to be able to mediate activation of Stat5 DNA......-binding activity, whereas the GH receptor mutant lacking all intracellular tyrosines was not. Synthetic tyrosine phosphorylated peptides corresponding to the GH receptor sequence around the three tyrosines inhibited Stat5 DNA-binding activity while their non-phosphorylated counterparts were ineffective. Tyrosine...

  20. Off-diagonal Seebeck effect and anisotropic thermopower in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} thin films

    Zahner, T.; Schreiner, R.; Stierstorfer, R.; Kus, O.; Lengfellner, H. [Regensburg Univ. (Germany). Inst. 2 - Experimentelle und Angewandte Physik; Li, S.T.; Roessler, R.; Pedarnig, J.D.; Baeuerle, D. [Johannes-Kepler-Univ., Linz (Austria). Inst. fuer Angewandte Physik


    The anisotropy {Delta}S of the thermopower in thin films of the high-T{sub c} superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} is investigated using off-c-axis epitaxial film growth and the off-diagonal Seebeck effect. The measurements represent a new method for the investigation of anisotropic transport properties in solids, taking advantage of the availability of oriented grown crystalline thin films instead of using bulk crystals. First results for the temperature dependence {Delta}S(T) in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} thin films are presented and described within a two-band model. Subjecting the films to heat treatments in different gases at relatively low temperatures, {Delta}S could reversibly be changed in a wide range. (orig.). 16 refs.

  1. (SNP) of GH gene in camel breeds reared in Egypt



    Mar 4, 2015 ... Full Length Research Paper. Detection of ... The aim of this study was to detect the genetic polymorphism of ... are Maghrabi (a dual purpose animal; (meat and milk) .... products of camel GH gene with MspI; TT: homozygous.

  2. Management of endocrine disease: GH excess: diagnosis and medical therapy

    Andersen, Marianne


    for acromegaly. Papers published on pasireotide have reported an increased risk of diabetes mellitus due to a reduction in insulin levels.Pegvisomant, the GH receptor antagonist, is indicated - alone or in combination with a somatostatin analogue - in most patients who fail to enter remission on a somatostatin...

  3. On the width of N-Delta and Delta-Delta states

    Niskanen, J A


    It is seen by a coupled-channel calculation that in the two-baryon N-Delta or Delta-Delta system the width of the state is greatly diminished due to the relative kinetic energy of the two baryons, since the internal energy of the particles, available for pionic decay, is smaller. A similar state dependent effect arises from the centrifugal barrier in N-Delta or Delta-Delta systems with non-zero orbital angular momentum. The double-Delta width can become even smaller than the free width of a single Delta. This has some bearing to the interpretation of the d'(2380) resonance recently discovered at COSY.

  4. In2O3/Bi2Sn2O7 heterostructured nanoparticles with enhanced photocatalytic activity

    Xing, Yonglei; Que, Wenxiu; Yin, Xingtian; He, Zuoli; Liu, Xiaobin; Yang, Yawei; Shao, Jinyou; Kong, Ling Bing


    In2O3/Bi2Sn2O7 composite photocatalysts with various contents of cubic In2O3 nanoparticles were fabricated by using impregnation method. A thriving modification of Bi2Sn2O7 by an introduction of In2O3 was confirmed by using X-ray diffraction, UV-vis diffuse reflectance spectrometry, transmission electron microscopy, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The samples composed of hybrids of In2O3 and Bi2Sn2O7 exhibited a much higher photocatalytic activity for the degradation of Rhodamine B under visible light, as compared with pure In2O3 and Bi2Sn2O7 nanoparticles. Optimized composition of the composite photocatalysts was 0.1In2O3/Bi2Sn2O7, which shows a rate constant higher than those of pure In2O3 and Bi2Sn2O7 by 4.06 and 3.21 times, respectively. Based on Mott-Schottky analysis and active species detection, the photoexcited electrons in the conduction band of In2O3 and the holes in the valence band of Bi2Sn2O7 participated in reduction and oxidation reactions, respectively. Hence, rad OH, rad O2- and h+ were the main active species involved in the photocatalytic reaction of the In2O3/Bi2Sn2O7 composite photocatalysts. The effective separation process of the photogenerated electron-hole pairs was testified by photocurrent test.

  5. N2O emission of HD vehicles

    Riemersma, I.J.; Jordaan, K.; Oonk, J.


    N2O is known to be a greenhouse gas with a high global warming potential, approximately 296 times higher than that of CO2 [11]. In road vehicles N2O is mostly formed by reactions in the exhaust catalyst. The IPCC (Intergovernmental Panel on Climate Changes) uses emission factors from research perfor

  6. Excellent ethanol sensing properties based on Er2O3-Fe2O3 nanotubes

    刘唱白; 何滢; 王圣蕾


    In this work, pureα-Fe2O3 and Er2O3-Fe2O3 nanotubes were synthesized by a simple single-capillary electrospin-ning technology followed by calcination treatment. The morphologies and crystal structures of the as-prepared samples were characterized by scanning electron microscopy and x-ray diffraction, respectively. The gas-sensing properties of the as-prepared samples have been researched, and the result shows that the Er2O3-Fe2O3 nanotubes exhibit much better sen-sitivity to ethanol. The response value of Er2O3-Fe2O3 nanotubes to 10 ppm ethanol is 21 at the operating temperature 240◦, which is 14 times larger than that of pureα-Fe2O3 nanotubes (response value is 1.5). The ethanol sensing properties ofα-Fe2O3 nanotubes are remarkably enhanced by doping Er, and the lowest detection limit of Er2O3-Fe2O3 nanotubes is 300 ppb, to which the response value is about 2. The response and recovery times are about 4 s and 70 s to 10 ppm ethanol, respectively. In addition, the Er2O3-Fe2O3 nanotubes possess good selectivity and long-term stability.

  7. Effect of GH/IGF-1 on Bone Metabolism and Osteoporsosis

    Vittorio Locatelli; Vittorio E. Bianchi


    Background. Growth hormone (GH) and insulin-like growth factor (IGF-1) are fundamental in skeletal growth during puberty and bone health throughout life. GH increases tissue formation by acting directly and indirectly on target cells; IGF-1 is a critical mediator of bone growth. Clinical studies reporting the use of GH and IGF-1 in osteoporosis and fracture healing are outlined. Methods. A Pubmed search revealed 39 clinical studies reporting the effects of GH and IGF-1 administration on bone ...

  8. Electronic parameters of Sr2Nb2O7 and chemical bonding

    Atuchin, V.V.; Grivel, Jean-Claude; Korotkov, A.S.


    /2)) and Delta(O-Sr) = BE(O 1s)-BE(Sr 3d(5/2)), were used to characterize the valence electron transfer on the formation of the Nb-O and Sr-O bonds. The chemical bonding effects were considered on the basis of our XPS results for Sr2Nb2O7 and earlier published structural and XPS data for other Sr- or Nb...

  9. Magnetite with anomalously high Cr2O3 as a fingerprint to trace upper Yangtze sediments to the sea

    Yue, Wei; Liu, James T.; Zhang, Dan; Wang, Zhanghua; Zhao, Baocheng; Chen, Zhongyuan; Chen, Jing


    This paper examines geochemical properties of detrital magnetite, in order to link sediments in a Plio-Quaternary core taken in the delta area to their sources in the Yangtze River basin. A total of 40 sediment samples were collected from both the main river channel/tributaries and a sediment core from the Yangtze delta. The geochemical compositions of detrital magnetite in these sediments were analyzed by electron microprobe, including FeO, TiO2, CoO, MgO, Cr2O3, MnO, ZnO, Al2O3 and V2O3. The results revealed that the detrital magnetite grains with anomalously high Cr2O3 occurred exclusively in the upper reaches of the Yangtze (upstream of the Three Gorges Dam), where the E'mei Basalt block is located. This type of magnetite could therefore be considered a unique sediment proxy of the upper river basin to help identify sediment source in the delta area. Our analysis found such magnetite grains with high Cr2O3 occurring throughout the core depth above 186.5 m, in contrast to the extremely low Cr2O3 below this depth. The boundary between high and low Cr2O3 in magnetite grains of the core sediments was dated by paleomagnetism at ca. ~ 1.2-1.0 Ma, signifying that the linkage between the Yangtze River course and the sea was before ~ 1.2-1.0 Ma. This demonstrates that the sediment provenance of the Yangtze delta has experienced a change from local to distal Yangtze River, which took place with the uplift of the Tibetan plateau and coastal subsidence during the Plio-Quaternary.

  10. geomorphology_delta

    California Department of Resources — Surficial geology of the Delta area of California by Brian Atwater of the U.S. Geological Survey. Source maps are from the USGS publication MF-1401. This digital...

  11. Preparation and Characterization of Fe2O3/Al2O3 Nano-composites


    Al2O3/Fe2O3 nano-composites were prepared by sol-gel route. The effect of Fe2O3 content on the structure, grain size and characterization of the composite were investigated through X-ray diffraction and M(o)ssbauer spectrum. The X-ray diffraction results show that Al2O3/Fe2O3 nano-composites with the Fe2O3, content of 40 wt% can be obtained after heat-treated at 900℃. The M(o)ssbauer effect results show that all samples exhibit clear super-paramagnetic phenomenon. Particles grow and defects reduce with the increasing of Fe2O3 conteni and some α-Fe2O3 stay magnetic order.

  12. Reduced recruitment and survival of primordial and growing follicles in GH receptor-deficient mice

    Slot, K.A.; Kastelijn, J.; Bachelot, A.; Kelly, P.A.; Binart, N.; Teerds, K.J.


    GH influences female fertility. The goal of the present study was to obtain more insight into the effect of loss of GH signalling, as observed in humans suffering from Laron syndrome, on ovarian function. Therefore, serial paraffin sections of ovaries of untreated and IGF-I-treated female GH recepto

  13. A Novel Tool for Peptide Pattern Recognition Identifies 13 Subgroups of the GH61 Family

    Busk, Peter Kamp; Lange, Mette; Lange, Lene


    Proteins of the glycosyl hydrolase family 61 (gh61) are important proteins for fungal degradation of biomass. There are 132 entries for gh61 in the CAZY database, no subfamilies have been defined and each fungus may have several gh61s with very different sequences. Alignment of highly divergent s...

  14. Delta-Reliability

    Eugster, P.; Guerraoui, R.; Kouznetsov, P.


    This paper presents a new, non-binary measure of the reliability of broadcast algorithms, called Delta-Reliability. This measure quantifies the reliability of practical broadcast algorithms that, on the one hand, were devised with some form of reliability in mind, but, on the other hand, are not considered reliable according to the ``traditional'' notion of broadcast reliability [HT94]. Our specification of Delta-Reliability suggests a further step towards bridging the gap between theory and...

  15. The growth hormone (GH)-insulin-like growth factor axis during testosterone replacement therapy in GH-treated hypopituitary males

    Fisker, Sidse; Nørrelund, Helene; Juul, A


    -independent effect on IGF-I and related parameters. Eight adult hypopituitary men (39.9 +/- 5.7 years) receiving growth hormone (GH) and testosterone replacement therapy (250 mg testosterone enantate every fourth week) participated in this prospective study. Frequent blood samples were drawn over a 5 week period...

  16. Changes in bone mineral density, body composition, and lipid metabolism during growth hormone (GH) treatment in children with GH deficiency

    A.M. Boot (Annemieke); M.A. Engels (Melanie); G.J.M. Boerma (Geert); E.P. Krenning (Eric); S.M.P.F. de Muinck Keizer-Schrama (Sabine)


    textabstractAdults with childhood onset GH deficiency (GHD) have reduced bone mass, increased fat mass, and disorders of lipid metabolism. The aim of the present study was to evaluate bone mineral density (BMD), bone metabolism, body composition, and lipid metabolism in

  17. Effects of growth hormone (GH therapy withdrawal on glucose metabolism in not confirmed GH deficient adolescents at final height.

    Flavia Prodam

    Full Text Available CONTEXT OBJECTIVE: Growth hormone deficiency (GHD is associated with insulin resistance and diabetes, in particular after treatment in children and adults with pre-existing metabolic risk factors. Our aims were. i to evaluate the effect on glucose metabolism of rhGH treatment and withdrawal in not confirmed GHD adolescents at the achievement of adult height; ii to investigate the impact of GH receptor gene genomic deletion of exon 3 (d3GHR. DESIGN SETTING: We performed a longitudinal study (1 year in a tertiary care center. METHODS: 23 GHD adolescent were followed in the last year of rhGH treatment (T0, 6 (T6 and 12 (T12 months after rhGH withdrawal with fasting and post-OGTT evaluations. 40 healthy adolescents were used as controls. HOMA-IR, HOMA%β, insulinogenic (INS and disposition (DI indexes were calculated. GHR genotypes were determined by multiplex PCR. RESULTS: In the group as a whole, fasting insulin (p<0.05, HOMA-IR (p<0.05, insulin and glucose levels during OGTT (p<0.01 progressively decreased from T0 to T12 becoming similar to controls. During rhGH, a compensatory insulin secretion with a stable DI was recorded, and, then, HOMAβ and INS decreased at T6 and T12 (p<0.05. By evaluating the GHR genotype, nDel GHD showed a decrease from T0 to T12 in HOMA-IR, HOMAβ, INS (p<0.05 and DI. Del GHD showed a gradual increase in DI (p<0.05 and INS with a stable HOMA-IR and higher HDL-cholesterol (p<0.01. CONCLUSIONS: In not confirmed GHD adolescents the fasting deterioration in glucose homeostasis during rhGH is efficaciously coupled with a compensatory insulin secretion and activity at OGTT. The presence of at least one d3GHR allele is associated with lower glucose levels and higher HOMA-β and DI after rhGH withdrawal. Screening for the d3GHR in the pediatric age may help physicians to follow and phenotype GHD patients also by a metabolic point of view.

  18. Effects of theophylline infusion on the growth hormone (GH) and prolactin response to GH-releasing hormone administration in acromegaly.

    Losa, M; Alba-Lopez, J; Schopohl, J; Sobiesczcyk, S; Chiodini, P G; Müller, O A; von Werder, K


    Since theophylline has been shown to blunt the GH response to growth hormone-releasing hormone (GHRH) in normal subjects, we investigated whether the same effect of theophylline administration could be reproduced in patients with active acromegaly. Ten acromegalic patients received on two different days 100 micrograms GHRH iv alone and the same GHRH dose during a constant infusion of theophylline (3.56 mg/min), beginning 2 h before GHRH administration. In the whole group theophylline did not affect basal GH secretion significantly (from a mean of 44.6 +/- 14.4 at 0 min to 41.8 +/- 13.5 ng/ml at 120 min). However, the amount of GH released after GHRH stimulation was lower when theophylline was concomitantly infused (7525 +/- 3709 ng min/ml vs. 12038 +/- 6337 ng min/ml; p less than 0.05). The inhibitory effect of theophylline was not homogeneous, since either marked or minimal reductions of the GHRH-stimulated GH secretion occurred. Serum PRL levels increased after GHRH administration in 6 patients and theophylline infusion had no influence upon this response. Peak GHRH levels were not different in both studies (14.9 +/- 1.7 and 17.1 +/- 4.0 ng/ml, respectively). Free fatty acid levels rose progressively during theophylline administration (from 0.66 +/- 0.10 at 0 min to 1.04 +/- 0.10 mEq/l at 240 min) and were significantly higher than after GHRH stimulation alone from 180 min up to the end of the test. Our results demonstrate that in active acromegaly theophylline blunts the GH response to GHRH, though this effect is not uniformly seen in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Effects of parenteral nutrition with and without GH on the GH/IGF-1 axis after hepatectomy in hepatocellular carcinoma with liver cirrhsis

    CAO Jie; LUO Shimin; LIANG Lijian; LAI Jiaming; CHEN Shanming


    Postoperative hepatic insulin-like growth factor-1(IGF-1)production may be severely disturbed in patients with liver cirrhosis.Complex alterations in the GH/IGF-1 axis are thought to play an important role in the protein catabolism that complicates major surgical procedures.The aim of this study was to explore the effects of parenteral nutrition (PN)with and without growth hormone(GH) on the GH/IGF-1 axis after hepatectomy for hepatocellular carcinoma(HCC)with cirrhosis and evaluate the potential roles of recombinant human GH(rhGH)therapy.Twenty-four patients with HCC with cirrhosis who underwent hepatectomy were randomly divided into two groups:a PN group (n=12)and an rhGH+PNgroup(n=12).Liver function,serum GH,IGF-1 and IGFBP-3 were measured before the operation and at postoperative days(POD)1 and 6.Insulin-like growth factor-1 and IGFBP-3 mRNA in the liver tissue was detected by RT-PCR.The liver Ki67 immunohistochemistry staining was studied.At the same time,12 patients with cholelithiasis or liver hemangioma who underwent operation served as normal control group.On POD 6,serum prealbumin,GH,IGF-1,IGFBP-3,hepatic IGF-1 mRNA,IGFBP-3 mRNA and liver Ki67 LI were higher in the rhGH+PN group than in the PN group.There was no significant difference in the 6-and 12-month tumor-free survival rate and the median tumor-free survival time between the PN group and the rhGH+PN group (P>0.05).These data indicate that rhGH+PN could ameliorate the changes in the GH/IGF-1 axis after hepatectomy for HCC in the setting of cirrhosis.

  20. Impact of recombinant human growth hormone (rh-GH treatment on psychiatric, neuropsychological and clinical profiles of GH deficient adults: a placebo - controlled trial



    Full Text Available BACKGROUND: Untreated GH-deficient adults have a diversity of dysfunctions (e.g. reduced muscle strength, emotional instability during stress, depressive symptoms that may cause deleterious effects on quality of life, and may be positively influenced by recombinant human growth hormone (rh-GH therapy. AIM: To evaluate the impact of a clinical intervention with rh-GH therapy on GH - deficient adults. METHOD: The physical, psychiatric and neuropsychological status of 9 GH-deficient adults was determined before and after the administration of rh-GH (0.250 IU/Kg/week in a double blind placebo-controlled trial for six months. Patients then received rh-GH for a further period of 6 months and their status was re-evaluated. RESULTS: Rh-GH was significant better than placebo at 6th month (p<0.05, producing increased serum Insulin like growth factor-I (IGF-1 levels, reduced body mass index (BMI and body fat, increased lean body mass and water, reduced waist/hip ratio and increased energy expenditure. The rh-GH therapy was also significantly better than placebo on depressive features as measured by the Hamilton Depression Scale (17-items (p= 0.0431 and the Beck Depression Inventory (p= 0.0431. Neuropsychological evaluations showed significant improvements in measures of Attention: Digit Backward (p= 0.035,Verbal Fluency (FAS (p= 0.02 and Cognitive Efficiency (WAIS-R tests: Vocabulary (p= 0.027 , Picture Arrangements (p= 0.017, and Comprehension (p= 0.01 following rh-GH therapy. CONCLUSION: The clinical, psychiatric, and neuropsychological impairments of untreated GH-deficient adults can be decreased by rh-GH therapy.

  1. Gender differences in serum GH and IGF-I levels and the GH response to dynamic tests in patients with acromegaly.

    Tanaka, Satoshi; Fukuda, Izumi; Hizuka, Naomi; Takano, Kazue


    Gender affects the GH secretory pattern both in normal subjects and in patients with acromegaly by an uncertain mechanism. Here, we report the influence of gender on the relationship between serum GH and IGF-I levels and the GH response to dynamic tests in patients with acromegaly. Seventy-four patients with untreated acromegaly (M/F 27/47, age range 22-86 yr.) were studied. The serum GH levels did not differ between male and female (6.1 vs. 8.7 ng/ml; p=0.26), while serum IGF-I levels, IGF-I SDS and the IGF-I/GH ratio were lower in female than those in male (679 vs. 769 ng/ml; p50 yr, serum IGF-I levels and IGF-I/GH ratios were lower in female than those in male in patients 50 yrs (684 vs. 680 ng/ml; p=0.39 and 98.7 vs. 118.4; p=0.40). The GH responses to OGTT, TRH, octreotide, and bromocriptine tests were similar in male and female. In conclusion, IGF-I/GH ratio was significantly lower in female than that in male particularly in younger patients with acromegaly. These data suggest that gender, presumably sex steroids in female, may partially modulate the relationship between circulating IGF-I and GH levels in patients with acromegaly.

  2. Sequential exercise in triathletes: variations in GH and water loss.

    Olivier Galy

    Full Text Available Growth hormone (GH may stimulate water loss during exercise by activating sweating. This study investigated GH secretion and water loss during sequential cycling and running, taking postural changes into account. The two exercise segments had similar durations and were performed at the same relative intensity to determine their respective contributions to water loss and the plasma volume variation noted in such trials. Eight elite triathletes first performed an incremental cycle test to assess maximal oxygen consumption. Then, the triathletes performed one of two trials in randomized order: constant submaximal cycling followed by treadmill running (C1-R2 or an inversed succession of running followed by cycling (R1-C2. Each segment of both trials was performed for 20 minutes at ∼75% of maximal oxygen consumption. The second trial, reversing the segment order of the first trial, took place two weeks later. During cycling, the triathletes used their own bicycles equipped with a profiled handlebar. Blood sampling (for GH concentrations, plasma viscosity and plasma volume variation was conducted at rest and after each segment while water loss was estimated from the post- and pre-measures. GH increases were significantly lower in R2 than C2 (72.2±50.1 vs. 164.0±157 ng x ml(-1 x min(-1, respectively; P<0.05. Water loss was significantly lower after C1-R2 than R1-C2 (1105±163 and 1235±153 ml, respectively; P<0.05. Plasma volume variation was significantly negative in C1 and R1 (-6.15±2.0 and -3.16±5.0%, respectively; P<0.05, not significant in C2, and significantly positive for seven subjects in R2 (4.05±3.1%. We concluded that the lower GH increases in R2 may have contributed to the smaller reduction in plasma volume by reducing sweating. Moreover, this lower GH response could be explained by the postural change during the transition from cycling to running. We recommend to pay particular attention to their hydration status during R1 which

  3. The effect of suppressor of cytokine signaling 3 on GH signaling in beta-cells

    Rønn, Sif G; Hansen, Johnny A; Lindberg, Karen


    GH is an important regulator of cell growth and metabolism. In the pancreas, GH stimulates mitogenesis as well as insulin production in beta-cells. The cellular effects of GH are exerted mainly through activation of the Janus kinase-signal transducer and activator of transcription (STAT) pathway....... Furthermore, using Northern blot analysis it was shown that SOCS-3 can completely inhibit GH-induced insulin production in these cells. Finally, 5-bromodeoxyuridine incorporation followed by fluorescence-activated cell sorting analysis showed that SOCS-3 inhibits GH-induced proliferation of INS-1 cells...

  4. Optimization of a GO2/GH2 Swirl Coaxial Injector Element

    Tucker, P. Kevin; Shyy, Wei; Vaidyanathan, Rajkumar


    An injector optimization methodology, method i, is used to investigate optimal design points for a gaseous oxygen/gaseous hydrogen (GO2/GH2) swirl coaxial injector element. The element is optimized in terms of design variables such as fuel pressure drop, DELTA P(sub f), oxidizer pressure drop, DELTA P(sub 0) combustor length, L(sub comb), and full cone swirl angle, theta, for a given mixture ratio and chamber pressure. Dependent variables such as energy release efficiency, ERE, wall heat flux, Q(sub w) injector heat flux, Q(sub inj), relative combustor weight, W(sub rel), and relative injector cost, C(sub rel), are calculated and then correlated with the design variables. An empirical design methodology is used to generate these responses for 180 combinations of input variables. Method i is then used to generate response surfaces for each dependent variable. Desirability functions based on dependent variable constraints are created and used to facilitate development of composite response surfaces representing some, or all, of the five dependent variables in terms of the input variables. Two examples illustrating the utility and flexibility of method i are discussed in detail. First, joint response surfaces are constructed by sequentially adding dependent variables. Optimum designs are identified after addition of each variable and the effect each variable has on the design is shown. This stepwise demonstration also highlights the importance of including variables such as weight and cost early in the design process. Secondly, using the composite response surface that includes all five dependent variables, unequal weights are assigned to emphasize certain variables relative to others. Here, method i is used to enable objective trade studies on design issues such as component life and thrust to weight ratio.

  5. Mutation of the SHP-2 binding site in growth hormone (GH) receptor prolongs GH-promoted tyrosyl phosphorylation of GH receptor, JAK2, and STAT5B

    Stofega, M R; Herrington, J; Billestrup, Nils;


    that the SH2 domains of SHP-2 bind directly to tyrosyl phosphorylated GHR from GH-treated cells. Tyrosine-to-phenylalanine mutation of tyrosine 595 of rat GHR greatly diminishes association of the SH2 domains of SHP-2 with GHR, and tyrosine-to-phenylalanine mutation of tyrosine 487 partially reduces...... phosphorylation. Consistent with the effects on STAT5B phosphorylation, tyrosine-to-phenylalanine mutation of tyrosine 595 prolongs the duration of tyrosyl phosphorylation of GHR and JAK2. These data suggest that tyrosine 595 is a major site of interaction of GHR with SHP-2, and that GHR-bound SHP-2 negatively...


    邓洁英; 史轶蘩; 尹娟娟


    To study the role of Ca2+ in the pathogenesis of pituitary growth hormone secreting adenornas,the function of Ca2+ in 23 cases of human pituitary GH-secreting adenoma was investigated in monolayer cell culture.It was found that Ca2- channel blockers nicardipin and nifedipin inhibited hasal and growth hormone releasing hormone (GRH)-stimulated GH secretion in 87.5% and 100.0% of the GH adenomas.respectively,demonstrating that in most human pituitary GH agonist octreotide regulated the processes of GH secretion via Ca2+ had defects in different steps including receptor.postreceptor Ca2+ channel and Ca2+-GH secreting coupling in 6(66.6%)and 5(55.5%) cases of 9 GH adenomas respectively.Among them,the defects in GRH receptor and SRIF regulated Ca2+ channel are the main causes of the dysfunction of GH adenomas.These defects may be related to GH hypersecretion in GH adenomas.Our data provides advance evidences for intrinsic defects of GH adenomas.

  7. Muscle and skeletal health in children and adolescents with GH deficiency.

    Improda, Nicola; Capalbo, Donatella; Esposito, Andrea; Salerno, Mariacarolina


    In addition to promoting linear growth, GH plays a key role in the regulation of bone and muscle development and metabolism. Although GH deficiency is frequently listed among the causes of secondary osteoporosis in children, its impact on bone and muscle health and on fracture risk is still not completely established. Current data suggest that childhood-onset GH deficiency can affect bone and muscle mass and strength, with GH replacement therapy exerting beneficial effects. Moreover, GH withdrawal at final height can result in reduced peak bone and muscle mass, potentially leading to increased fracture risk in adulthood. Thus, the muscle-bone unit in GH deficient subjects should be monitored during childhood and adolescence in order to prevent osteoporosis and increased fracture risk and GH replacement should be tailored to ensure an optimal bone and muscle health.

  8. Hyperpolarized H2O MR angiography

    Ardenkjær-Larsen, Jan Henrik; Laustsen, Christoffer; Bowen, Sean


    polarization followed by dissolution in D2O. A water 1H signal enhancement of 77 times compared with 4.7 Tesla was obtained. This corresponds to a polarization of 3.5% for the 3.9 mol/L 1H in D2O . Moreover, a T1 in excess of 20 s was achieved. The use of hyperpolarized water as a contrast agent presents a new...

  9. Investigation of luminescence and laser transition of Dy3+ in Li2O-Gd2O3-Bi2O3-B2O3 glasses

    Zaman, F.; Kaewkhao, J.; Srisittipokakun, N.; Wantana, N.; Kim, H. J.; Rooh, G.


    The aim of this study is to develop Li2O-Gd2O3-Bi2O3-B2O3 glass doped with different concentration of Dy3+ ions by melt quenching technique for different applications in photonics and laser devices. From the experimental oscillator strength (fexp) of the absorption spectra the JO intensity parameters (Ω λ = 2, 4, 6) have been calculated, and by using these JO intensity parameters various radiative parameters were calculated. By using JO theory the radiative transition probability (AR), radiative lifetime (τR) and branching ratio (βR) for Dy3+ ion have been found. A decrease in lifetimes of the prepared glass by increasing concentration of Dy3+ is because of the energy transfer through cross relaxation and resonant energy transfer channels in the present glass matrix. Using experimental and calculated lifetimes, the quantum efficiency (η) and non-radiative relaxation rates (WNR) of 4F9/2 excited state have been calculated. From emission spectra, effective bandwidths (Δλeff) and emission stimulated emission cross section σ (λp) were found for 4F9/2 → 6HJ (J = 15/2, 13/2, 11/2 and 9/2). Chromaticity results revealed that the CCT values of the LGBiBDy glass samples are in between to those of day light and commercial white light LED sources. Further investigations are under way for the optimization of dopant concentration in the Li2O-Gd2O3-Bi2O3-B2O3 glass.

  10. V2O5 nanofibre sheet actuators

    Gu, Gang; Schmid, Michael; Chiu, Po-Wen; Minett, Andrew; Fraysse, Jerôme; Kim, Gyu-Tae; Roth, Siegmar; Kozlov, Mikhail; Muñoz, Edgar; Baughman, Ray H.


    Vanadium oxides, such as V2O5, are promising for lithium-ion batteries, catalysis, electrochromic devices and sensors. Vanadium oxides were proposed more than a decade ago for another redox-dependent application: the direct conversion of electrical energy to mechanical energy in actuators (artificial muscles). Although related conducting polymer and carbon nanotube actuators have been demonstrated, electromechanical actuators based on vanadium oxides have not be realized. V2O5 nanofibres and nanotubes provide the potential advantages of low-cost synthesis by sol-gel routes and high charging capacity and long cycle life. Here, we demonstrate electromechanical actuation for obtained high modulus V2O5 sheets comprising entangled V2O5 nanofibres. The high surface area of these V2O5 sheets facilitates electrochemical charge injection and intercalation that causes the electromechanical actuation. We show that the V2O5 sheets provide high Young's modulus, high actuator-generated stress, and high actuator stroke at low applied voltage.

  11. N2O molecular tagging velocimetry

    ElBaz, A. M.; Pitz, R. W.


    A new seeded velocity measurement technique, N2O molecular tagging velocimetry (MTV), is developed to measure velocity in wind tunnels by photochemically creating an NO tag line. Nitrous oxide "laughing gas" is seeded into the air flow. A 193 nm ArF excimer laser dissociates the N2O to O(1D) that subsequently reacts with N2O to form NO. O2 fluorescence induced by the ArF laser "writes" the original position of the NO line. After a time delay, the shifted NO line is "read" by a 226-nm laser sheet and the velocity is determined by time-of-flight. At standard atmospheric conditions with 4% N2O in air, ˜1000 ppm of NO is photochemically created in an air jet based on experiment and simulation. Chemical kinetic simulations predict 800-1200 ppm of NO for 190-750 K at 1 atm and 850-1000 ppm of NO for 0.25-1 atm at 190 K. Decreasing the gas pressure (or increasing the temperature) increases the NO ppm level. The presence of humid air has no significant effect on NO formation. The very short NO formation time (helium) since the NO tag line is created by chemical reaction of N2O with O(1D) from N2O photodissociation and thus does not depend on the bulk gas composition.

  12. Mode of GH administration and gene expression in the female rat brain.

    Walser, Marion; Schiöler, Linus; Oscarsson, Jan; Åberg, Maria A I; Wickelgren, Ruth; Svensson, Johan; Isgaard, Jörgen; Aberg, N David


    The endogenous secretion of growth hormone (GH) is sexually dimorphic in rats with females having a more even and males a more pulsatile secretion and low trough levels. The mode of GH administration, mimicking the sexually dimorphic secretion, has different systemic effects. In the brains of male rats, we have previously found that the mode of GH administration differently affects neuron haemoglobin beta (Hbb) expression whereas effects on other transcripts were moderate. The different modes of GH administration could have different effects on brain transcripts in female rats. Hypophysectomised female rats were given GH either as injections twice daily or as continuous infusion and GH-responsive transcripts were assessed by quantitative reverse transcription polymerase chain reaction in the hippocampus and parietal cortex (cortex). The different modes of GH-administration markedly increased Hbb and 5'-aminolevulinate synthase 2 (Alas2) in both brain regions. As other effects were relatively moderate, a mixed model analysis (MMA) was used to investigate general effects of the treatments. In the hippocampus, MMA showed that GH-infusion suppressed glia- and neuron-related transcript expression whereas GH-injections increased expression. In the cortex, GH-infusion instead increased neuron-related transcripts, whereas GH-injections had no significant effect. Interestingly, this contrasts to previous results from male rat cortex where GH-infusion generally decreased expression levels. In conclusion, the results indicate that there is a small but significant difference in response to mode of GH administration, in the hippocampus as compared to the cortex. For both modes of GH administration, there was a robust effect on Hbb and Alas2.

  13. Stereotactic Irradiation of GH-Secreting Pituitary Adenomas

    G. Minniti


    Full Text Available Radiotherapy (RT is often employed in patients with acromegaly refractory to medical and/or surgical interventions in order to prevent tumour regrowth and normalize elevated GH and IGF-I levels. It achieves tumour control and hormone normalization up to 90% and 70% of patients at 10–15 years. Despite the excellent tumour control, conventional RT is associated with a potential risk of developing late toxicity, especially hypopituitarism, and its role in the management of patients with GH-secreting pituitary adenomas remains a matter of debate. Stereotactic techniques have been developed with the aim to deliver more localized irradiation and minimize the long-term consequences of treatment, while improving its efficacy. Stereotactic irradiation can be given in a single dose as stereotactic radiosurgery (SRS or in multiple doses as fractionated stereotactic radiotherapy (FSRT. We have reviewed the recent published literature on stereotactic techniques for GH-secreting pituitary tumors with the aim to define the efficacy and potential adverse effects of each of these techniques.

  14. {\\delta}M Formalism

    Talebian-Ashkezari, Alireza; Abolhasani, Ali Akbar


    We study the evolution of the "non-perturbative" metric perturbations in a Bianchi background in the long-wavelength limit. By applying the gradient expansion to the equations of motion we exhibit a generalized "Separate Universe" approach to the cosmological perturbation theory. Having found this consistent separate universe picture, we introduce the "{\\delta}M formalism" for calculating the evolution of the tensor perturbations in anisotropic inflation models in almost similar way as the so-called {\\delta}N formula for the super-horizon dynamics of the curvature perturbations. Likewise its ancestor, {\\delta}N formalism, this new method can substantially reduce the amount of calculations related to the evolution of the tensor modes.

  15. Pressureless reactive sintering mechanism of nanocrystalline Bi2O3-Y2O3 solid electrolyte


    The nanocrystalline Bi2O3-Y2O3 solid electrolyte material was synthesized by pressureless reactive sintering process with Bi2O3 and Y2O3 nano mixed powder as raw materials, which was prepared by a chemical coprecipitation process. The study on the behavior of nano δ-Bi2O3 formation and its grain growth showed that the solid solution reaction of Y2O3 and β-Bi2O3 to form δ-Bi2O3occurs mainly in the initial stage of sintering process, and nano δ-Bi2O3 crystal grains grow approximately following the rule of paracurve ((D-D0)2=K.t) during sintering process. After sintered at 600℃ for 2 h, the samples could reach above 96% in relative density and have dense microstructure with few remaining pores, the δ-Bi2O3 grains are less than 100 nm in size.

  16. Variations in H2O+/H2O ratios toward massive star-forming regions

    Wyrowski, F; Herpin, F; Baudry, A; Bontemps, S; Chavarria, L; Frieswijk, W; Jacq, T; Marseille, M; Shipman, R; van Dishoeck, E F; Benz, A O; Caselli, P; Hogerheijde, M R; Johnstone, D; Liseau, R; Bachiller, R; Benedettini, M; Bergin, E; Bjerkeli, P; Blake, G; Braine, J; Bruderer, S; Cernicharo, J; Codella, C; Daniel, F; di Giorgio, A M; Dominik, C; Doty, S D; Encrenaz, P; Fich, M; Fuente, A; Giannini, T; Goicoechea, J R; de Graauw, Th; Helmich, F; Herczeg, G J; Jørgensen, J K; Kristensen, L E; Larsson, B; Lis, D; McCoey, C; Melnick, G; Nisini, B; Olberg, M; Parise, B; Pearson, J C; Plume, R; Risacher, C; Santiago, J; Saraceno, P; Tafalla, M; van Kempen, T A; Visser, R; Wampfler, S; Yıldız, U A; Black, J H; Falgarone, E; Gerin, M; Roelfsema, P; Dieleman, P; Beintema, D; De Jonge, A; Whyborn, N; Stutzki, J; Ossenkopf, V


    Early results from the Herschel Space Observatory revealed the water cation H2O+ to be an abundant ingredient of the interstellar medium. Here we present new observations of the H2O and H2O+ lines at 1113.3 and 1115.2 GHz using the Herschel Space Observatory toward a sample of high-mass star-forming regions to observationally study the relation between H2O and H2O+ . Nine out of ten sources show absorption from H2O+ in a range of environments: the molecular clumps surrounding the forming and newly formed massive stars, bright high-velocity outflows associated with the massive protostars, and unrelated low-density clouds along the line of sight. Column densities per velocity component of H2 O+ are found in the range of 10^12 to a few 10^13 cm-2 . The highest N(H2O+) column densities are found in the outflows of the sources. The ratios of H2O+/H2O are determined in a range from 0.01 to a few and are found to differ strongly between the observed environments with much lower ratios in the massive (proto)cluster e...

  17. The absence of GH signaling affects the susceptibility to high-fat diet-induced hypothalamic inflammation in male mice

    Baquedano, Eva; Ruiz-Lopez, Ana M; Sustarsic, Elahu G


    GH is important in metabolic control, and mice with disruption of the gene encoding the GH receptor (GHR) and GH binding protein (GHR-/- mice) are dwarf with low serum IGF-1 and insulin levels, high GH levels, and increased longevity, despite their obesity and altered lipid and metabolic profiles...

  18. GH and IGF1 levels are positively associated with musculotendinous collagen expression: experiments in acromegalic and GH deficiency patients.

    Doessing, Simon; Holm, Lars; Heinemeier, Katja M; Feldt-Rasmussen, Ulla; Schjerling, Peter; Qvortrup, Klaus; Larsen, Jytte O; Nielsen, Rie H; Flyvbjerg, Allan; Kjaer, Michael


    Disproportionate growth of musculoskeletal tissue is a major cause of morbidity in both acromegalic (ACRO) and GH-deficient (GHD) patients. GH/IGF1 is likely to play an important role in the regulation of tendon and muscle collagen. We hypothesized that the local production of collagen is associated with the level of GH/IGF1. As primary outcomes, collagen mRNA expression and collagen protein fractional synthesis rate (FSR) were determined locally in skeletal muscle and tendon in nine ACRO and nine GHD patients. Moreover, muscle myofibrillar protein synthesis and tendon collagen morphology were determined. Muscle collagen I and III mRNA expression was higher in ACRO patients versus GHD patients (P<0.05), whereas collagen protein FSR did not differ significantly between ACRO and GHD patients in muscle (P=0.21) and tendon (P=0.15). IGF1Ea and IGF1Ec mRNA expression in muscle was higher in ACRO patients versus GHD patients (P<0.01). Muscle IGF1Ea mRNA expression correlated positively with collagen I mRNA expression (P<0.01). Tendon collagen fibrillar area tended to be higher in GHD patients relative to ACRO patients (P=0.07). Thus, we observed a higher expression for collagen and IGF1 mRNA in local musculotendinous tissue in ACRO patients relative to GHD patients. Moreover, there was a tendency towards a higher collagen protein FSR and a smaller collagen fibril diameter in ACRO patients relative to GHD patients. The results indicate a collagen-stimulating role of local IGF1 in human connective tissue and add to the understanding of musculoskeletal pathology in patients with either high or low GH/IGF1 axis activity.

  19. The effect of growth hormone (GH) replacement on muscle strength in patients with GH-deficiency: a meta-analysis.

    Widdowson, W Matthew


    CONTEXT\\/OBJECTIVES: GH replacement increases muscle mass and reduces body fat in growth hormone deficiency (GHD) adults. A recent meta-analysis has demonstrated that this improvement in body composition is associated with improved exercise performance. The current meta-analysis was carried out to determine whether high-quality evidence exists to support a beneficial effect of GH replacement on strength. DESIGN\\/METHODS: An extensive Medline search\\/literature review identified eight studies with utilizable, robust data, involving 231 patients in nine cohorts. Previously unpublished data were sought from authors and obtained in two cases. All studies included were randomized, double-blind, placebo-controlled, of parallel or cross-over design and of an average 6.7 months duration. Information was retrieved in uniform format, with data pertaining to patient numbers, study-design, GH-dose, mean age, IGF-I levels and muscle strength measurements (isometric or isokinetic quadriceps strength) recorded. Data were analysed using a fixed-effects model, utilizing continuous data measured on different scales. A summary effect measure (d(s)) was derived for individual strength variables, whereas an overall summary effect was derived from the sum of all studies incorporating different variables; 95% CIs were calculated from the weighted variances of individual study effects. RESULTS: Analysis revealed no significant improvement, neither when all studies were combined (d(s) = +0.01 +\\/- 0.26) nor when measured individually (isometric quadriceps strength, d(s) = +0.02 +\\/- 0.32 and isokinetic quadriceps strength, d(s) = 0.00 +\\/- 0.45). CONCLUSIONS: Evidence from short-term controlled studies fails to support a benefit on muscle strength of GH replacement in GHD patients, which is likely to occur over a longer time-course, as seen in open-label studies.

  20. Effects of recombinant growth hormone (GH) replacement and psychomotor and cognitive stimulation in the neurodevelopment of GH-deficient (GHD) children with cerebral palsy: a pilot study.

    Devesa, Jesús; Alonso, Begoña; Casteleiro, Nerea; Couto, Paula; Castañón, Beatriz; Zas, Eva; Reimunde, Pedro


    Cerebral palsy (CP) is the main cause of physical disability in childhood and is an important health issue that has a strong socioeconomic impact. There is no effective treatment for CP and therapeutic approaches report only partial benefits for affected people. In this study we assessed the effects of growth hormone (GH) treatment combined with psychomotor and cognitive stimulation in the neurodevelopment of children with CP and GH deficiency (GHD). The study was carried out in 11 patients (7 boys and 4 girls; 4.12 ± 1.31 years) with GHD and CP who were treated with recombinant GH (rGH) and psychomotor and cognitive stimulation during 2 months. Battelle Developmental Inventory Screening Test (BDIST) was performed 2 months before commencing GH treatment, just before commencing GH administration, and after 2 months of combined treatment involving GH and cognitive stimulation. Psychomotor and cognitive status did not change during the period in which only cognitive stimulation was performed; however, significant improvements in personal and social skills, adaptive behavior, gross motor skills and total psychomotor abilities, receptive and total communication, cognitive skills and in the total score of the test (P < 0.01), and in fine motor skills and expressive communication (P < 0.02) were observed after the combined treatment period. Therefore, GH replacement together with psychomotor and cognitive stimulation seem to be useful for the appropriate neurodevelopment of children with GHD and CP.

  1. Chemical stability of La2O3 in La2O3-Mo cathode materials


    Chemical stability of La2O3 in carbonized and uncarbonized La2O3-Mo cathodes was studied by in-situ XPS analysis. Experimental results show that chemical stability of La2O3 is not good enough. In vacuum and at high temperature, oxygen can be dissociated from the lattice of La2O3 in the uncarbonized La2O3-Mo cathode. Binding energy shifts of La?3d5/2 and La?3d3/2 core peaks, and obvious decrease of satellite peak intensity in La?3d doublet with increasing temperature show that metallic La appears at carbonized La2O3-Mo cathode surface at high temperature.

  2. Clinical challenges in the management of isolated GH deficiency type IA in adulthood.

    Casteràs, Anna; Kratzsch, Jürgen; Ferrández, Angel; Zafón, Carles; Carrascosa, Antonio; Mesa, Jordi


    Isolated GH deficiency type IA (IGHDIA) is an infrequent cause of severe congenital GHD, often managed by pediatric endocrinologists, and hence few cases in adulthood have been reported. Herein, we describe the clinical status of a 56-year-old male with IGHDIA due to a 6.7 kb deletion in GH1 gene that encodes GH, located on chromosome 17. We also describe phenotypic and biochemical parameters, as well as characterization of anti-GH antibodies after a new attempt made to treat with GH. The height of the adult patient was 123 cm. He presented with type 2 diabetes mellitus, dyslipidemia, osteoporosis, and low physical and psychological performance, compatible with GHD symptomatology. Anti-GH antibodies in high titers and with binding activity (>101 IU/ml) were found 50 years after exposure to exogenous GH, and their levels increased significantly (>200 U/ml) after a 3-month course of 0.2 mg/day recombinant human GH (rhGH) treatment. Higher doses of rhGH (1 mg daily) did not overcome the blockade, and no change in undetectable IGF1 levels was observed (time, as well as pituitary hormones periodically assessed.

  3. Neuroprotection by GH against excitotoxic-induced cell death in retinal ganglion cells.

    Martínez-Moreno, Carlos G; Ávila-Mendoza, José; Wu, Yilun; Arellanes-Licea, Elvira Del Carmen; Louie, Marcela; Luna, Maricela; Arámburo, Carlos; Harvey, Steve


    Retinal growth hormone (GH) has been shown to promote cell survival in retinal ganglion cells (RGCs) during developmental waves of apoptosis during chicken embryonic development. The possibility that it might also against excitotoxicity-induced cell death was therefore examined in the present study, which utilized quail-derived QNR/D cells as an in vitro RGC model. QNR/D cell death was induced by glutamate in the presence of BSO (buthionine sulfoxamide) (an enhancer of oxidative stress), but this was significantly reduced (PGH (rcGH). Similarly, QNR/D cells that had been prior transfected with a GH plasmid to overexpress secreted and non-secreted GH. This treatment reduced the number of TUNEL-labeled cells and blocked their release of lactate dehydrogenase (LDH). In a further experiment with dissected neuroretinal explants from ED (embryonic day) 10 embryos, rcGH treatment of the explants also reduced (PGH-overexpressing QNR/D cells. As rcGH treatment and GH-overexpression cells also increased the content of IGF-1 and IGF-1 mRNA this neuroprotective action of GH is likely to be mediated, at least partially, through an IGF-1 mechanism. This possibility is supported by the fact that the siRNA knockdown of GH or IGF-1 significantly reduced QNR/D cell viability, as did the immunoneutralization of IGF-1. GH is therefore neuroprotective against excitotoxicity-induced RGC cell death by anti-apoptotic actions involving IGF-1 stimulation.

  4. Glass transition temperature and conductivity in Li2O and Na2O doped borophosphate glasses

    Ashwajeet, J. S.; Sankarappa, T.; Ramanna, R.; Sujatha, T.; Awasthi, A. M.


    Two alkali doped Borophosphate glasses in the composition, (B2O3)0.2. (P2O5)0.3. (Na2O)(0.5-x). (Li2O)x, where x = 0.05 to 0.50 were prepared by standard melt quenching method at 1200K. Non-crystalline nature was confirmed by XRD studies. Room temperature density was measured by Archimedes principle. DC conductivity in the temperature range from 300K to 575K has been measured. Samples were DSC studied in the temperature range from 423K to 673K and glass transition temperature was determined. Glass transition temperature passed through minima for Li2O con.2centration between 0.25 and 0.30 mole fractions. Activation energy of conduction has been determined by analyzing temperature variation of conductivity determining Arrhenius law. Conductivity passed through minimum and activation passed through maximum for Li2O content from 0.25 to 0.30 mole fractions. Glass transition temperature passed through minimum for the same range of Li2O content. These results revealed mixed alkali effect taking place in these glasses. It is for the first time borophosphate glasses doped with Li2O and Na2O have been studied for density and dc conductivity and, the mixed alkali effect (MAE) has been observed.

  5. The Niger Delta Crisis



    Sep 28, 2013 ... lions de barils par jour à environ 1 million au plus fort de la crise du Delta ... (JTF) between 13 May 2009 and 4 October 2009 (the deadline for embrac- ..... He had just ended his welcome address as the occasion's chairman.

  6. Electron spin resonance study of a-Cr2O3 and Cr2O3·nH2O quasi-spherical nanoparticles

    Khamlich, S


    Full Text Available The quasi-spherical nanoparticles of hydrated Cr2O3 · nH2O, and crystalline -Cr2O3, have been synthesized by reduction of the first row (3d) transition metal complex of K2Cr2O7. The temperaturedependence of electron spin resonance (ESR) spectrum...

  7. Wettability of silicon carbide ceramic by Al2O3/Dy2O3 and Al2O3/Yb2O3 systems

    J.A.da Silva; B.M.Moreschi; G.C.R.Garcia; S.Ribeiro


    Wettability is an important phenomenon in the liquid phase sintering of silicon carbide (SiC) ceramics.This work involved a study of the wetting of SiC ceramics by two oxide systems,Al2O3/Dy2O3 and Al2O3/Yb2O3,which have so far not been studied for application in the sintering of SiC ceramics.Five mixtures of each system were prepared,with different compositions close to their respective eutectic ones.Samples of the mixtures were pressed into cylindrical specimens,which were placed on a SiC plate and subjected to temperatures above their melting points using a graphite resistance furnace.The behavior of the melted mixtures on the SiC plate was observed by means of an imaging system using a CCD camera and the sessile drop method was employed to determine the contact angle,the parameter that measures the degree of wettability.The results of variation in the contact angle as a function of temperature were plotted in graphic form which showed that the curves displayed a fast decline and good spreading.All the samples of the two systems presented final contact angles of 40° to 10° indicating their good wetting on SiC in the argon atmosphere.The melted/solidified area and interface between SiC and melted/solidified phase were evaluated by scanning electron microscopy (SEM) and their crystalline phases were identified by X-ray diffraction (DRX).The DRX analysis showed that Al2O3 and RE2O3 reacted and formed the Dy3Al5O12 (DyAg) and Yb3Al5O12 (YbAg) phases.The results indicated that the two systems had a promising potential as additives for the sintering of SiC ceramics.

  8. Structural and Physical Properties of Fe2O3-B2O3-V2O5 Glasses

    Virender Kundu


    Full Text Available The structural and physical properties of xFe2O3-(40-x B2O3-60V2O5  (0≤x≤20 glass system have been investigated. The samples were prepared by normal melt-quench technique. The structural changes were inferred by means of FTIR by monitoring the infrared (IR spectra in the spectral range 600–4000 cm-1. The absence of boroxol ring (806 cm-1 in the present glass system suggested that these glasses consist of randomly connected BO3 and BO4 units. The conversion of BO3 to BO4 and VO5 to VO4 tetrahedra along with the formation of non-bridging oxygen's (NBOs attached to boron and vanadium takes place in the glasses under investigation. The density and molar volume of the present glass system were found to depend on Fe2O3 content. DC conductivity of the glass system has been determined in the temperature range 310–500 K. It was found that the general behavior of electrical conductivity was similar for all glass compositions and found to increase with increasing iron content. The parameters such as activation energy, average separation between transition metal ions (TMIs, polaron radius, and so forth have been calculated in adiabatic region and are found consistent with Mott's model of phonon-assisted polaronic hopping.

  9. Kinetics of HO2 + HO2 -> H2O2 + O2: Implications for Stratospheric H2O2

    Christensen, L. E.; Okumura, M.; Sander, S. P.; Salawitch, R. J.; Toon, G. C.; Sen, B.; Blavier, J.-F.; Jucks, K. W.


    The reaction HO2 + HO2 -> H2O2 + O2refid="df01" type="formula">(1) has been studied at 100 Torr and 222 K to 295 K. Experiments employing photolysis of Cl2/CH3OH/O2/N2 and F2/H2/O2/N2 gas mixtures to produce HO2 confirmed that methanol enhanced the observed reaction rate. At 100 Torr, zero methanol, k1 = (8.8 +/- 0.9) 10-13 × exp[(210 +/- 26)/T] cm3 molecule-1 s-1 (2σ uncertainties), which agrees with current recommendations at 295 K but is nearly 2 times slower at 231 K. The general expression for k1, which includes the dependence on bath gas density, is k1 = (1.5 +/- 0.2) × 10-12 × exp[(19 +/- 31)/T] + 1.7 × 10-33 × [M] × exp[1000/T], where the second term is taken from the JPL00-3 recommendation. The revised rate largely accounts for a discrepancy between modeled and measured [H2O2] in the lower to middle stratosphere.

  10. Spin-liquid behavior and weak static magnetism in pyrochlore Pr2Ir2O7

    Heffner, R H [Los Alamos National Laboratory; Maclaughlin, D E [NON LANL; Nakatsuji, S [NON LANL; Machida, Y [NON LANL


    Muon spin relaxation experiments have been performed in powder samples of the pyrochlore iridate Pr{sub 2}Ir{sub 2}O{sub 7} for temperatures in the range 0.02-250 K. Two-component muon spin relaxation functions are observed up to {approx}> 150 K, indicating static magnetism with a freezing temperature T{sub f} of this value or higher. The static muon spin relaxation rate {Delta}. suggests weak-moment freezing ({approx} 10{sup -1} {micro}{sub B} at T = 0), probably due to Ir{sup 4+} spin ordering as in isostructural Y{sub 2}Ir{sub 2}O{sub 7}. The temperature dependence of {Delta} is highly unusual, decreasing smoothly by orders of magnitude but remaining nonzero for T < T{sub f}. The smoothness of {Delta}(T) suggests that Pr{sup 3+} moments do not order down to 0.025 K. The dynamic relaxation rate {Lambda} increases markedly below {approx}20 K, indicating a shift of spin fluctuation noise power to low frequencies in the spin-liquid state. At low temperatures {Lambda} is strong and temperature-independent, indicative of numerous low-lying spin excitations as is common in frustrated antiferromagnets.

  11. Association of cGH EcoRV Gene with Production in Tolaki Chicken

    Muhammad Amrullah Pagala


    Full Text Available cGH (Chicken Growth Hormone gene plays a crucial role in production responses of chicken. The objective of the research was to investigate the association of cGH gene with production in Tolaki chicken. Tolaki chicken is native chickens from Southeast Sulawesi Province of Indonesian. cGH gene was genotyped in 58 Tolaki chicken with PCR-RFLP. PCR was used to amplify genomic DNA for GH gene (399 bp. The amplicon was cutted by EcoRV and produced three genotypes: AA, AG, and GG and two alleles: A and G allele. The study showed the association of GH gene polymorphism with Production traits. GG genotype have better production (daily weight gain and feed conversion than AG genotype in Tolaki chicken, providing evidence that GH gene might be an important candidate gene for production traits.

  12. Síntese e caracterização do compósito Al2O3 -YAG e do Al2O3-YAG e Al2O3 aditivados com Nb2O5 Synthesis and characterization of Al2O3 -YAG composite and Al2O3-YAG and Al2O3 with Nb2O5 additives

    R. F. Cabral


    Full Text Available O compósito Al2O3-YAG possui alta resistência à corrosão e à fluência em ambientes agressivos, o que permite vislumbrar aplicações bastante atrativas, tais como aletas de motores a jato e de turbinas a gás. Este compósito também apresenta elevada dureza e alta resistência à abrasão possibilitando o seu emprego em blindagens balísticas. Nesse estudo os pós precursores de Al2O3, Y2O3 e Nb2O5 foram homogeneizados em moinho de bolas planetário por 4 h, secados em estufa a 120 ºC por 48 h, desaglomerados e peneirados. O compósito Al2O3-YAG foi produzido a partir das misturas de Al2O3-Y2O3 a 1300 ºC por 2 h. Foram produzidas amostras de Al2O3-YAG, Al2O3-YAG com Nb2O5 e Al2O3 com Nb2O5. Posteriormente os pós foram prensados uniaxialmente a 70 MPa. A sinterização foi feita a 1400 e 1450 ºC. Os pós como recebidos e os processados foram caracterizados quanto à área de superfície específica e ao tamanho médio de partícula. Os materiais sinterizados foram caracterizados por densidade e porosidade aparente pelo método de Arquimedes e avaliados quanto à retração e à perda de massa. Os resultados mostraram que são necessários ainda ajustes nas condições de sinterização da composição Al2O3-YAG com Nb2O5 para melhorar a densificação e a retração, que foram baixas, da ordem de 60 e 3%, respectivamente. O Al2O3 aditivado com Nb2O5, por sua vez, apresentou uma densificação satisfatória, de 96% e uma retração em torno de 15%.The Al2O3-YAG composite exhibits high corrosion and creep resistance in aggressive environments, which provides quite glimpse attractive applications such as jet engine vanes and as gas turbines. This composite also shows high hardness and wear resistance allowing its use in ballistic armor. In this study, precursor powders of Al2O3, Y2O3 and Nb2O5 were homogeneously mixed in a planetary ball mill for 4 h, dried in an oven at 120 ºC for 48 h, sieved and deagglomerated. The Al2O3-YAG composite

  13. Fall and Rise of a D$_2$O Ice Cube in Liquid H$_2$O


    The demonstration described in this article is to show thatwhile H$_2$O ice floats in water, D$_2$O ice sinks in water, provingthe higher density of ‘heavy water’. This experiment can bedone in a classroom or in an auditoriam.

  14. Photodesorption of H2O, HDO, and D2O ice and its impact on fractionation

    Arasa, Carina; Kroes, Geert-Jan; Walsh, Catherine; van Dishoeck, Ewine F


    The HDO/H2O ratio in interstellar gas is often used to draw conclusions on the origin of water in star-forming regions and on Earth. In cold cores and in the outer regions of protoplanetary disks, gas-phase water comes from photodesorption of water ice. We present fitting formulae for implementation in astrochemical models using photodesorption efficiencies for all water ice isotopologues obtained using classical molecular dynamics simulations. We investigate if the gas-phase HDO/H2O ratio reflects that present in the ice or whether fractionation can occur during photodesorption. Probabilities for the top four monolayers are presented for photodesorption of X (X=H,D) atoms, OX radicals, and X2O and HDO molecules following photodissociation of H2O, D2O, and HDO in H2O amorphous ice at temperatures from 10-100 K. Isotope effects are found for all products: (1) H atom photodesorption probabilities from H2O ice are larger than those for D atom photodesorption from D2O ice by a factor of 1.1; the ratio of H and D ...

  15. Oxidation Resistance of Fe-13Cr Alloy with Micro-Laminated (ZrO2-Y2O3)/(Al2O3-Y2O3) Films

    Yao Mingming; He Yedong; Wang Deren; Gao Wei


    The micro-laminated (ZrO2-Y2O3)/(Al2O3-Y2O3) composite films were prepared on the surface of Fe-13Cr alloy by an electrochemical process and a sintering process alternately. High-resolution field emission scanning electron microscopy (FE-SEM) was used to characterize the laminated films, indicating that the micro-laminated (ZrO2-Y2O3)/(Al2O3-Y2O3) films have nano-structures. SEM, EDS and mass gain measurement were adopted to study the oxidation resistance of films on Fe-13Cr alloy. It is proved that such micro-laminated films are more effective than ZrO2-Y2O3 or Al2O3-Y2O3 films to resist the oxidation of the alloy, and the oxidation resistance is increased with increasing layers in micro-laminated films. These beneficial effects can be contributed to the mechanism, by which such micro-laminated (ZrO2-Y2O3)/(Al2O3-Y2O3) composite film combines all the beneficial effects and overcomes all the disadvantages of both ZrO2-Y2O3 film and Al2O3-Y2O3 film during oxidation of alloy.

  16. Functional divergence of GhCFE5 homoeologs revealed in cotton fiber and Arabidopsis root cell development.

    Lv, Fenni; Li, Peng; Zhang, Rui; Li, Nina; Guo, Wangzhen


    In GhCFE5 homoeologs, GhCFE5D interacted with more actin homologs and stronger interaction activity than GhCFE5A. GhCFE5D - but not GhCFE5A -overexpression severely disrupted actin cytoskeleton organization and significantly suppressed cell elongation. Homoeologous genes are common in polyploid plants; however, their functional divergence is poorly elucidated. Allotetraploid Upland cotton (Gossypium hirsutum, AADD) is the most widely cultivated cotton; accounting for more than 90 % of the world's cotton production. Here, we characterized GhCFE5A and GhCFE5D homoeologs from G. hirsutum acc TM-1. GhCFE5 homoeologs are expressed preferentially in fiber cells; and a significantly greater accumulation of GhCFE5A mRNA than GhCFE5D mRNA was found in all tested tissues. Overexpression of GhCFE5D but not GhCFE5A seriously inhibits the Arabidopsis hypocotyl and root cell elongation. Yeast two-hybrid assay and bimolecular fluorescence complementation (BiFC) analysis showed that compared with GhCFE5A, GhCFE5D interacts with more actin homologs and has a stronger interaction activity both from Arabidopsis and Upland cotton. Interestingly, subcellular localization showed that GhCFE5 resides on the cortical endoplasmic reticulum (ER) network and is colocalized with actin cables. The interaction activities between GhCFE5 homoeologs and actin differ in their effects on F-actin structure in transgenic Arabidopsis root cells. The F-actin changed direction from vertical to lateral, and the actin cytoskeleton organization was severely disrupted in GhCFE5D-overexpressing root cells. These data support the functional divergence of GhCFE5 homoeologs in the actin cytoskeleton structure and cell elongation, implying an important role for GhCFE5 in the evolution and selection of cotton fiber.

  17. GH/IGF-I Transgene Expression on Muscle Homeostasis

    Schwartz, Robert J.


    We propose to test the hypothesis that the growth hormone/ insulin like growth factor-I axis through autocrine/paracrine mechanisms may provide long term muscle homeostasis under conditions of prolonged weightlessness. As a key alternative to hormone replacement therapy, ectopic production of hGH, growth hormone releasing hormone (GHRH), and IGF-I will be studied for its potential on muscle mass impact in transgenic mice under simulated microgravity. Expression of either hGH or IGF-I would provide a chronic source of a growth-promoting protein whose biosynthesis or secretion is shut down in space. Muscle expression of the IGF-I transgene has demonstrated about a 20% increase in hind limb muscle mass over control nontransgenic litter mates. These recent experiments, also establish the utility of hind-limb suspension in mice as a workable model to study atrophy in weight bearing muscles. Thus, transgenic mice will be used in hind-limb suspension models to determine the role of GH/IGF-I on maintenance of muscle mass and whether concentric exercises might act in synergy with hormone treatment. As a means to engineer and ensure long-term protein production that would be workable in humans, gene therapy technology will be used by to monitor muscle mass preservation during hind-limb suspension, after direct intramuscular injection of a genetically engineered muscle-specific vector expressing GHRH. Effects of this gene-based therapy will be assessed in both fast twitch (medial gastrocnemius) and slow twitch muscle (soleus). End-points include muscle size, ultrastructure, fiber type, and contractile function, in normal animals, hind limb suspension, and reambutation.

  18. GH/IGF-I Transgene Expression on Muscle Homeostasis

    Schwartz, Robert J.


    We propose to test the hypothesis that the growth hormone/ insulin like growth factor-I axis through autocrine/paracrine mechanisms may provide long term muscle homeostasis under conditions of prolonged weightlessness. As a key alternative to hormone replacement therapy, ectopic production of hGH, growth hormone releasing hormone (GHRH), and IGF-I will be studied for its potential on muscle mass impact in transgenic mice under simulated microgravity. Expression of either hGH or IGF-I would provide a chronic source of a growth-promoting protein whose biosynthesis or secretion is shut down in space. Muscle expression of the IGF-I transgene has demonstrated about a 20% increase in hind limb muscle mass over control nontransgenic litter mates. These recent experiments, also establish the utility of hind-limb suspension in mice as a workable model to study atrophy in weight bearing muscles. Thus, transgenic mice will be used in hind-limb suspension models to determine the role of GH/IGF-I on maintenance of muscle mass and whether concentric exercises might act in synergy with hormone treatment. As a means to engineer and ensure long-term protein production that would be workable in humans, gene therapy technology will be used by to monitor muscle mass preservation during hind-limb suspension, after direct intramuscular injection of a genetically engineered muscle-specific vector expressing GHRH. Effects of this gene-based therapy will be assessed in both fast twitch (medial gastrocnemius) and slow twitch muscle (soleus). End-points include muscle size, ultrastructure, fiber type, and contractile function, in normal animals, hind limb suspension, and reambutation.

  19. DELTAS: A new Global Delta Sustainability Initiative (Invited)

    Foufoula-Georgiou, E.


    Deltas are economic and environmental hotspots, food baskets for many nations, home to a large part of the world population, and hosts of exceptional biodiversity and rich ecosystems. Deltas, being at the land-water interface, are international, regional, and local transport hubs, thus providing the basis for intense economic activities. Yet, deltas are deteriorating at an alarming rate as 'victims' of human actions (e.g. water and sediment reduction due to upstream basin development), climatic impacts (e.g. sea level rise and flooding from rivers and intense tropical storms), and local exploration (e.g. sand or aggregates, groundwater and hydrocarbon extraction). Although many efforts exist on individual deltas around the world, a comprehensive global delta sustainability initiative that promotes awareness, science integration, data and knowledge sharing, and development of decision support tools for an effective dialogue between scientists, managers and policy makers is lacking. Recently, the international scientific community proposed to establish the International Year of Deltas (IYD) to serve as the beginning of such a Global Delta Sustainability Initiative. The IYD was proposed as a year to: (1) increase awareness and attention to the value and vulnerability of deltas worldwide; (2) promote and enhance international and regional cooperation at the scientific, policy, and stakeholder level; and (3) serve as a launching pad for a 10-year committed effort to understand deltas as complex socio-ecological systems and ensure preparedness in protecting and restoring them in a rapidly changing environment. In this talk, the vision for such an international coordinated effort on delta sustainability will be presented as developed by a large number of international experts and recently funded through the Belmont Forum International Opportunities Fund. Participating countries include: U.S., France, Germany, U.K., India, Japan, Netherlands, Norway, Brazil, Bangladesh

  20. Thermodynamic Assessment of the Y2o3-yb2o3-zro2 System

    Jacobson, Nathan S.; Liu, Zi-Kui; Kaufman, Larry; Zhang, Fan


    Yttria-zirconia (Y2O3-ZrO2) is the most widely used of the rare earth oxide-zirconia systems. There are numerous experimental studies of the phase boundaries in this system. In this paper, we assess these data and derive parameters for the solution models in this system. There is current interest in other rare earth oxide-zirconia systems as well as systems with several rare earth oxides and zirconia, which may offer improved properties over the Y2O3-ZrO2 system. For this reason, we also assess the ytterbia-zirconia (Yb2O3-ZrO2) and Y2O3-Yb2O3-ZrO2 system.

  1. EPA H2O Software Tool

    EPA H2O allows user to: Understand the significance of EGS in Tampa Bay watershed; visually analyze spatial distribution of the EGS in Tampa Bay watershed; obtain map and summary statistics of EGS values in Tampa Bay watershed; analyze and compare potential impacts of development...

  2. EPA H2O User Manual

    EPA H2O is a software tool designed to support research being conducted in the Tampa Bay watershed to provide information, data, and approaches and guidance that communities can use to examine alternatives when making strategic decisions to support a prosperous and environmentall...

  3. Assessment of Ga2O3 technology


    architecture [60]. ....................................................................... 10 Figure 5: Photograph of 4-inch diameter Ga2O3 wafer...breakdown voltages can provide orders of magnitude reduction in system size, cost and weight. Figure 4: A More-Electric Aircraft (MEA) architecture [60...Technology base is narrowly located in Japan . Mainstream technology. Czochralski • Mature technology base. • Crucible-free crystal growth

  4. The role of the growth hormone (GH) receptor and JAK1 and JAK2 kinases in the activation of Stats 1, 3, and 5 by GH

    Smit, L S; Meyer, D J; Billestrup, Nils


    GH has been shown to activate the GH receptor (GHR)-associated tyrosine kinase JAK2 and the Src homology 2 domain-containing transcription factors Stats (signal transducers and activators of transcription) 1, 3, and 5. The present work investigates the role of GHR and JAK2 in the activation...... of Stats 1, 3, and 5 by GH. The ability of GH to stimulate the tyrosyl phosphorylation of these Stats was assessed in Chinese hamster ovary (CHO) cells expressing truncated and mutated GHR. GH was observed to stimulate tyrosyl phosphorylation of Stats 1, 3, and 5 in CHO cells expressing GHRs that bind JAK2...... [GHR1-638 (full-length) and GHR1-454 (lacks approximately half of the cytoplasmic domain)] but not in CHO cells expressing GHR that do not bind JAK2 (GHR1-318 or GHR1-294). GH-dependent tyrosyl phosphorylation of Stat5, but not Stats 1 or 3, was reduced in CHO cells expressing GHR1-454. GH...

  5. Preclinical and Clinical In Vitro In Vivo Correlation of an hGH Dextran Microsphere Formulation

    de Vrueh, R.; Gresnigt, M. G.; Hoogerbrugge, C. M.; van Buul-Offers, S. C.; de Leede, L. G. J.; Sterkman, L. G. W.; Crommelin, D. J. A.; Hennink, W. E.; Verrijk, R.


    Purpose To investigate the in vitro in vivo correlation of a sustained release formulation for human growth hormone (hGH) based on hydroxyethyl methacrylated dextran (dex-HEMA) microspheres in Pit-1 deficient Snell dwarf mice and in healthy human volunteers. Materials and Methods A hGH-loaded microsphere formulation was developed and tested in Snell dwarf mice (pharmacodynamic study) and in healthy human volunteers (pharmacokinetic study). Results Single subcutaneous administration of the microspheres in mice resulted in a good correlation between hGH released in vitro and in vivo effects for the hGH-loaded microsphere formulation similar to daily injected hGH indicating a retained bioactivity. Testing the microspheres in healthy volunteers showed an increase (over 7–8 days) in hGH serum concentrations (peak concentrations: 1–2.5 ng/ml). A good in vitro in vivo correlation was obtained between the measured and calculated (from in vitro release data) hGH serum concentrations. Moreover, an increased serum concentration of biomarkers (insulin-like growth factor-I (IGF-I), IGF binding protein-3 (IGFBP-3) was found again indicating that bioactive hGH was released from the microspheres. Conclusions Good in vitro in vivo correlations were obtained for hGH-loaded dex-HEMA microspheres, which is an important advantage in predicting the effect of the controlled drug delivery product in a clinical situations. PMID:17929148

  6. The GH/IGF-1 axis in obesity: pathophysiology and therapeutic considerations.

    Berryman, Darlene E; Glad, Camilla A M; List, Edward O; Johannsson, Gudmundur


    Obesity has become one of the most common medical problems in developed countries, and this disorder is associated with high incidences of hypertension, dyslipidaemia, cardiovascular disease, type 2 diabetes mellitus and specific cancers. Growth hormone (GH) stimulates the production of insulin-like growth factor 1 in most tissues, and together GH and insulin-like growth factor 1 exert powerful collective actions on fat, protein and glucose metabolism. Clinical trials assessing the effects of GH treatment in patients with obesity have shown consistent reductions in total adipose tissue mass, in particular abdominal and visceral adipose tissue depots. Moreover, studies in patients with abdominal obesity demonstrate a marked effect of GH therapy on body composition and on lipid and glucose homeostasis. Therefore, administration of recombinant human GH or activation of endogenous GH production has great potential to influence the onset and metabolic consequences of obesity. However, the clinical use of GH is not without controversy, given conflicting results regarding its effects on glucose metabolism. This Review provides an introduction to the role of GH in obesity and summarizes clinical and preclinical data that describe how GH can influence the obese state.

  7. Structure of the GH1 domain of guanylate kinase-associated protein from Rattus norvegicus

    Tong, Junsen; Yang, Huiseon [College of Pharmacy, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Eom, Soo Hyun [School of Life Sciences, Steitz Center for Structural Biology, and Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Chun, ChangJu, E-mail: [College of Pharmacy, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Im, Young Jun, E-mail: [College of Pharmacy, Chonnam National University, Gwangju 500-757 (Korea, Republic of)


    Graphical abstract: - Highlights: • The crystal structure of GKAP homology domain 1 (GH1) was determined. • GKAP GH1 is a three-helix bundle connected by short flexible loops. • The predicted helix α4 associates weakly with the helix α3, suggesting dynamic nature of the GH1 domain. - Abstract: Guanylate-kinase-associated protein (GKAP) is a scaffolding protein that links NMDA receptor-PSD-95 to Shank–Homer complexes by protein–protein interactions at the synaptic junction. GKAP family proteins are characterized by the presence of a C-terminal conserved GKAP homology domain 1 (GH1) of unknown structure and function. In this study, crystal structure of the GH1 domain of GKAP from Rattus norvegicus was determined in fusion with an N-terminal maltose-binding protein at 2.0 Å resolution. The structure of GKAP GH1 displays a three-helix bundle connected by short flexible loops. The predicted helix α4 which was not visible in the crystal structure associates weakly with the helix α3 suggesting dynamic nature of the GH1 domain. The strict conservation of GH1 domain across GKAP family members and the lack of a catalytic active site required for enzyme activity imply that the GH1 domain might serve as a protein–protein interaction module for the synaptic protein clustering.

  8. Osmoregulatory actions of the GH/IGF axis in non-salmonid teleosts

    Mancera, J.M.; McCormick, S.D.


    Salmonid fishes provided the first findings on the influence of the growth hormone (GH)/insulin-like growth factor I (IGF-I) axis on osmoregulation in teleost fishes. Recent studies on non-salmonid species, however, indicate that this physiological action of the GH/IGF-I axis is not restricted to salmonids or anadromous fishes. GH-producing cells in the pituitary of fish acclimated to different salinities show different degrees of activation depending on the species studied. Plasma GH levels either increase or do not change after transfer of fish from freshwater to seawater. Treatment with GH or IGF-I increases salinity tolerance and/or increases gill Na+,K+-ATPase activity of killifish (Fundulus heteroclitus), tilapia (Oreochromis mossambicus and Oreochromis niloticus) and striped bass (Morone saxatilis). As in salmonids, a positive interaction between GH and cortisol for improving hypoosmoregulatory capacity has been described in tilapia (O. mossambicus). Research on the osmoregulatory role of the GH/IGF-I axis is derived from a small number of teleost species. The study of more species with different osmoregulary patterns will be necessary to fully clarify the osmoregulatory role of GH/IGF-I axis in fish. The available data does suggest, however, that the influence of the GH/IGF-I axis on osmoregulation may be a common feature of euryhalinity in teleosts. Copyright (C) 1998 Elsevier Science Inc.

  9. GH gene polymorphisms and expression associated with egg laying in muscovy ducks (Cairina moschata).

    Wu, X; Yan, M J; Lian, S Y; Liu, X T; Li, A


    Accumulated evidence suggests that the growth hormone (GH) gene plays a physiological role in the control of reproductive function. Here, we examined the correlation between egg-laying traits and GH gene polymorphisms and expression patterns in the muscovy duck (Cairina moschata). PCR single-strand conformation polymorphism was used to identify polymorphisms in intron 3 of GH. One single nucleotide polymorphism (g.3270 A > G) was detected by sequencing, and the frequencies of the A and G alleles in the population were 0.65 and 0.35, respectively. A comparison test showed that the AA genotype group had more consecutive laying days and more eggs at 300 days than the GG genotype group (P 0.05). Such a significant correlation between GH polymorphisms and egg-laying performance suggested that GH could be a candidate locus affecting the laying trait in muscovy duck. Furthermore, real-time fluorescent quantitative PCR demonstrated that GH is expressed in all selected tissues, but is highly expressed in the hypothalamic-pituitary-gonadal axis and heart. This unique expression pattern suggested that GH may exert its local physiological function through the autocrine or paracrine pathway during gonad development and growth in the muscovy duck. The data presented in this paper revealed GH polymorphisms and expression patterns in the muscovy duck and indicated a potential regulatory effect of GH on reproduction.

  10. Direct stimulation of bone mass by increased GH signalling in the osteoblasts of Socs2-/- mice.

    Dobie, R; MacRae, V E; Huesa, C; van't Hof, R; Ahmed, S F; Farquharson, C


    The suppressor of cytokine signalling (Socs2(-/-))-knockout mouse is characterised by an overgrowth phenotype due to enhanced GH signalling. The objective of this study was to define the Socs2(-/-) bone phenotype and determine whether GH promotes bone mass via IGF1-dependent mechanisms. Despite no elevation in systemic IGF1 levels, increased body weight in 4-week-old Socs2(-/-) mice following GH treatment was associated with increased cortical bone area (Ct.Ar) (PGH. Indeed, male Socs2(-/-) mice had increased Ct.Ar (PGH action. Mechanistic studies showed that in osteoblasts and bone of Socs2(-/-) mice, STAT5 phosphorylation was significantly increased in response to GH. Conversely, overexpression of SOCS2 decreased GH-induced STAT5 signalling. Although an increase in Igf1 expression was observed in Socs2(-/-) osteoblasts following GH, it was not evident in vivo. Igf1 expression levels were not elevated in response to GH in 4-week-old mice and no alterations in expression was observed in bone samples of 6-week-old Socs2(-/-) mice. These studies emphasise the critical role of SOCS2 in controlling the local GH anabolic bone effects. We provide compelling evidence implicating SOCS2 in the regulation of GH osteoblast signalling and ultimately bone accrual, which maybe via mechanisms that are independent of IGF1 production in vivo.

  11. Expression of a cotton profilin gene GhPFN1 is associated with fiber cell elongation


    Profilin is an important actin-binding protein involved in regulating the organization of actin filaments. A cotton profilin gene (GhPFN1) that shares 71% identity to profilin1 of Arabidopsis in its amino acid sequence was isolated. Semi-quantitative RT-PCR showed that GhPFN1 was expressed preferentially in the developing cotton fibers and reached the highest level at the fast elongation stage. The function of GhPFN1 in vivo was analyzed using the S. pombe system, and results suggested that GhPFN1 plays a role in fiber cell elongation.

  12. GH mediates exercise-dependent activation of SVZ neural precursor cells in aged mice.

    Daniel G Blackmore

    Full Text Available Here we demonstrate, both in vivo and in vitro, that growth hormone (GH mediates precursor cell activation in the subventricular zone (SVZ of the aged (12-month-old brain following exercise, and that GH signaling stimulates precursor activation to a similar extent to exercise. Our results reveal that both addition of GH in culture and direct intracerebroventricular infusion of GH stimulate neural precursor cells in the aged brain. In contrast, no increase in neurosphere numbers was observed in GH receptor null animals following exercise. Continuous infusion of a GH antagonist into the lateral ventricle of wild-type animals completely abolished the exercise-induced increase in neural precursor cell number. Given that the aged brain does not recover well after injury, we investigated the direct effect of exercise and GH on neural precursor cell activation following irradiation. This revealed that physical exercise as well as infusion of GH promoted repopulation of neural precursor cells in irradiated aged animals. Conversely, infusion of a GH antagonist during exercise prevented recovery of precursor cells in the SVZ following irradiation.

  13. Genetic and protein biomarkers in blood for the improved detection of GH abuse.

    Ferro, P; Ventura, R; Pérez-Mañá, C; Farré, M; Segura, J


    Human Growth Hormone (hGH, somatotropin) is one of the relevant forbidden substances to be detected in sport drug testing. Since the appearance of recombinant hGH (rhGH) in the 80's, its expansion and availability through the black market have increased, so the detection of its abuse continues to be a challenge at present. New techniques or biomarkers that are robust, reliable, sensitive and allowing a large detection time window are welcome. rhGH produces an increase of insulin-like growth factor 1 (IGF-1). FN1 (fibronectin 1) and RAB31 (member of RAS oncogene family) genes have been suggested as two potential biomarkers for IGF-1 abuse. Following this line, in the present study some genetic and proteomic approaches have been performed with fourteen healthy male subjects treated with rhGH (which produces increase of IGF-1 concentrations) to study FN1 gene, FN1 protein, RAB31 gene and RAB31 protein as potential biomarkers for rhGH abuse. The results showed that both, RAB31 and FN1 genes and FN1 protein could be potential biomarkers for rhGH administration. Preliminary assessments of gender, age, acute sport activities and GHRP-2 (pralmorelin, a rhGH releasing peptide) influence suggest they are not relevant confounding factors. Thus, the selected markers present high sensitivity and a larger detection window for rhGH detection than IGF-1 itself.

  14. H2O Paradox and its Implications on H2O in Moon

    Zhang, Youxue


    The concentration of H2O in the mantle of a planetary body plays a significant role in the viscosity and partial melting and hence the convection and evolution of the planetary body. Even though the composition of the primitive terrestrial mantle (PTM) is thought to be well known [1-2], the concentration of H2O in PTM remains paradoxial because different methods of estimation give different results [3]: Using H2O/Ce ratio in MORB and OIB and Ce concentration in PTM, the H2O concentration in PTM would be (300÷×1.5) ppm; using mass balance by adding surface water to the mantle [3-4], H2O concentration in PTM would be (900÷×1.3) ppm [2-3]. The inconsistency based on these two seemingly reliable methods is referred to as the H2O paradox [3]. For Moon, H2O contents in the primitive lunar mantle (PLM) estimated from H2O in plagioclase in lunar anorthosite and that from H2O/Ce ratio in melt inclusions are roughly consistent at ˜110 ppm [5-6] even though there is still debate about the volatile depletion trend [7]. One possible solution to the H2O paradox in PTM is to assume that early Earth experienced whole mantle degassing, which lowered the H2O/Ce ratio in the whole mantle but without depleting Ce in the mantle. The second possible solution is that some deep Earth reservoirs with high H2O/Ce ratios have not been sampled by MORB and OIB. Candidates include the transition zone [8] and the D" layer. The third possible solution is that ocean water only partially originated from mantle degassing, but partially from extraterrestrial sources such as comets [9-10]. At present, there is not enough information to determine which scenario is the answer to the H2O paradox. On the other hand, each scenario would have its own implications to H2O in PLM. If the first scenario applies to Moon, because degassed H2O or H2 would have escaped from the lunar surface, the very early lunar mantle could have much higher H2O [11] than that obtained using the H2O/Ce ratio method. The

  15. Is increase in bone mineral content caused by increase in skeletal muscle mass/strength in adult patients with GH-treated GH deficiency? A systematic literature analysis

    Klefter, O.; Feldt-Rasmussen, U.


    OBJECTIVE: Adult patients with GH deficiency (GHD) are characterized by a reduced muscle mass, but also reduced bone mineral density (BMD) and content (BMC), which have been ascribed to GHD per se. The aim of this study was to investigate if changes in BMD/BMC in adult GHD patients could be due...... performed a systematic literature analysis, including 51 clinical trials published between 1996 and 2008, which had studied the development in muscle mass, muscle strength, BMD, and/or BMC in GH-treated adult GHD patients. RESULTS: GH therapy had an anabolic effect on skeletal muscle. The largest increase...

  16. Pulsatile characteristics of spontaneous growth hormone (GH) concentration profiles in boys evaluated by an ultrasensitive immunoradiometric assay: Evidence for ultradian periodicity of GH secretion

    Goji, Katsumi (Kobe Children' s Hospital (Japan))


    To investigate underlying ultradian periodicities in spontaneous circulating GH concentrations, blood samples were drawn from 15 normal short boys every 20 min over a 24-h period, and plasma GH concentrations were measured using an ultrasensitive immunoradiometric assay. The limit of detection for the GH assay was 0.01 [mu]g/L. The GH time series were analyzed using the Cluster program, Ultra program, cosinor analysis, and autocorrelation analysis. Plasma GH concentrations in 1,095 samples derived from 15 normal short boys were all within the detectable range of the assay and ranged from 0.07-52.2 [mu]g/L. Thirty-six percent of the GH values in the 1,095 samples from 15 normal short boys were below 1 [mu]g/L, and 82% of them occurred during the diurnal awakening period. Cluster analysis disclosed a total of 176 peaks in 15 normal short boys, with a mean [+-] SEM number of significant GH peaks of 12.1 [+-] 0.5/24 h. Twelve percent of the 176 peaks were below 1 [mu]g/L, and 95% of them occurred during the diurnal awakening period. In addition, Cluster analysis disclosed 161 interpulse intervals in total, with a mean [+-] SEM interval of 116.5 [+-] 4.3 min. The GH interpulse interval did not show a significant 24-h rhythm, whereas the GH peak height increased significantly at night. An independent discrete peak detection in program, Ultra, identified 12.6 [+-] 0.5 GH peaks/24 h. This result was in good agreement with that from analysis by the Cluster program (P = NS). Autocorrelation analysis revealed that GH time series were significantly autocorrelated in 9 of the 15 boys, with maximal autocorrelation coefficients at 115.5 min, on the average. The mean autocorrelation coefficient for a group of 15 normal short boys was significantly positive at a 100-min lag. These findings suggest that there could be a regularly occurring periodicity of approximately 100-120 min in the human GH time series. 18 refs., 4 figs., 1 tab.

  17. Growth hormone (GH) treatment increases serum insulin-like growth factor binding protein-3, bone isoenzyme alkaline phosphatase and forearm bone mineral content in young adults with GH deficiency of childhood onset

    Juul, A; Pedersen, S A; Sørensen, S;


    Recent studies have demonstrated that growth hormone (GH)-deficient adults have a markedly decreased bone mineral content compared to healthy adults. However, there are conflicting results regarding the effects of GH treatment on bone mineral content in GH-deficient adults. Therefore, we evaluated...... the effect of GH treatment on a marker of bone formation (bone alkaline phosphatase), hepatic excretory function and distal forearm bone mineral content in GH-deficient adults. Growth hormone was administered subcutaneously in 21 adults (13 males and 8 females) with GH deficiency of childhood onset for 4...

  18. Mössbauer study and magnetic properties of MgFe2O4 crystallized from the glass system B2O3/K2O/P2O5/MgO/Fe2O3

    Shabrawy, S. El; Bocker, C.; Miglierini, M.; Schaaf, P.; Tzankov, D.; Georgieva, M.; Harizanova, R.; Rüssel, C.


    An iron containing magnesium borate glass with the mol% composition 51.7 B2O3/9.3 K2O /1 P2O5/27.6MgO/10.4Fe2O3was prepared by the conventional melts quenching method followed by a thermal treatment process at temperatures in the range from 530 to 604 °C.The thermally treated samples were characterized by X-ray diffraction, scanning and transmission electron microscopy. It was shown that superparamagnetic MgFe2O4 nanoparticles were formed during thermal treatment. The size of the spinel type crystals was in the range from 6 to 15 nm. Mössbauer spectra of the powdered glass ceramic samples and the extracted nanoparticles after dissolving the glass matrix in diluted acid were recorded at room temperature. The deconvolution of the spectra revealed the crystallization of two spinel phases MgFe2O4 (as a dominant phase) and superparamagnetic maghemite, γ-Fe2O3 (as a secondary phase). Room temperature magnetic measurements showed that, increasing the crystallization temperature changed the superparamagnetic behavior of the samples to ferrimagnetic behavior. The Curie temperatures of the samples were measured and showed a higher value than that of the pure bulk MgFe2O4.

  19. Raman and Fluorescence Spectroscopy of CeO2, Er2O3, Nd2O3, Tm2O3, Yb2O3, La2O3, and Tb4O7

    Jianlan Cui


    Full Text Available To better understand and ascertain the mechanisms of flotation reagent interaction with rare earth (RE minerals, it is necessary to determine the physical and chemical properties of the constituent components. Seven rare earth oxides (CeO2, Er2O3, Nd2O3, Tm2O3, Yb2O3, La2O3, and Tb4O7 that cover the rare earth elements (REEs from light to heavy REEs have been investigated using Raman spectroscopy. Multiple laser sources (wavelengths of 325 nm, 442 nm, 514 nm, and 632.8 nm for the Raman shift ranges from 100 cm−1 to 5000 cm−1 of these excitations were used for each individual rare earth oxide. Raman shifts and fluorescence emission have been identified. Theoretical energy levels for Er, Nd, and Yb were used for the interpretation of fluorescence emission. The experimental results showed good agreement with the theoretical calculation for Er2O3 and Nd2O3. Additional fluorescence emission was observed with Yb2O3 that did not fit the reported energy level diagram. Tb4O7 was observed undergoing laser induced changes during examination.

  20. Research on Glass Forming Ability of Er2O3 -Al2O3 -B2O3 -SiO2 System

    Zhang Qitu; Fu Zhenxiao; Ni Yaru; Lu Chunhua; Xu Zhongzi


    The glass forming range of Er2O3-Al2O3-B2O3-SiO2 system was explored, and the effect of the content of Al2 O3 and Er2 O3 on glass-forming region was experimentally examined. It is shown that the region of glass formation range expends when the content of Al2O3 is changed from 15% to 20%, while it shrinks when the content of Er2O3 is changed from 20% to 30%. At the same time, the glass forming ability of Er2O3-Al2O3-B2O3-SiO2 system was also discussed using a value of β, which is an indication of crystallization tendency of glasses, calculated from thermo-analysis data. It is found that the glass forming ability of Er2O3-Al2O3-B2O3- SiO2 glasses is poor, while the glasses network may be enhanced when Al2O3 is added to the system, the glass forming ability being heightened. In addition, the crystallization temperatures of the rare earth glasses were determined using differential thermal analysis technique. The Er2O3-Al2O;-B2O3-SiO2 glass samples were heat treated at 1000,1100 and 1260℃ respectively. The results show that it is the Er2O3 phase that separates out from the glasses after crystaline heat treatment, and it is tiered up in glasses, as detected through XRD and SEM. This indicates that the phase separation occurs when the glasses are heated, Er3+ being mainly distributed in the boron rich phase, then separated out from glasses, while the silicate rich phase remaining glassy state.

  1. Photodesorption of Ices II: H2O and D2O

    Oberg, Karin I; Visser, Ruud; van Dishoeck, Ewine F


    Gaseous H2O has been detected in several cold astrophysical environments, where the observed abundances cannot be explained by thermal desorption of H2O ice or by H2O gas phase formation. These observations hence suggest an efficient non-thermal ice desorption mechanism. Here, we present experimentally determined UV photodesorption yields of H2O and D2O ice and deduce their photodesorption mechanism. The ice photodesorption is studied under ultra high vacuum conditions and at astrochemically relevant temperatures (18-100 K) using a hydrogen discharge lamp (7-10.5 eV), which simulates the interstellar UV field. The ice desorption during irradiation is monitored using reflection absorption infrared spectroscopy of the ice and simultaneous mass spectrometry of the desorbed species. The photodesorption yield per incident photon is identical for H2O and D2O and depends on both ice thickness and temperature. For ices thicker than 8 monolayers the photodesorption yield Y is linearly dependent on temperature due to i...

  2. Raman spectrum of the solid electrolytes LiI·H2O and LiI·D2O

    Poulsen, Finn Willy


    The Raman spectra of cubic LiI·H2O and LiI·D2O have been revised. The spectra reveal only internal and librational modes of H2O (D2O). The isotopic ratios νH/νD, are in the range 1.33-1.78......The Raman spectra of cubic LiI·H2O and LiI·D2O have been revised. The spectra reveal only internal and librational modes of H2O (D2O). The isotopic ratios νH/νD, are in the range 1.33-1.78...

  3. Zn-VI/Cu2O Heterojunctions for Earth-Abundant Photovoltaics

    Wilson, Samantha

    The need for sustainable energy production motivates the study of photovoltaic materials, which convert energy from sunlight directly into electricity. This work has focused on the development of Cu2O as an earth-abundant solar absorber due to the abundance of its constituent elements in the earth's crust, its suitable band gap, and its potential for low cost processing. Crystalline wafers of Cu2O with minority carrier diffusion lengths on the order of microns can be manufactured in a uniquely simple fashion --- directly from copper foils by thermal oxidation. Furthermore, Cu2Ohas an optical band gap of 1.9 eV, which gives it a detailed balance energy conversion efficiency of 24.7% and the possibility for an independently connected Si/Cu 2O dual junction with a detailed balance efficiency of 44.3%. However, the highest energy conversion efficiency achieved in a photovoltaic device with a Cu2O absorber layer is currently only 5.38% despite the favorable optical and electronic properties listed above. There are several challenges to making a Cu2O photovoltaic device, including an inability to dope the material, its relatively low chemical stability compared to other oxides, and a lack of suitable heterojunction partners due to an unusually small electron affinity. We have addressed the low chemical stability, namely the fact that Cu2O is an especially reactive oxide due to its low enthalpy of formation (DeltaHf0 = -168.7 kJ/mol), by developing a novel surface preparation technique. We have addressed the lack of suitable heterojunction partners by investigating the heterojunction band alignment of several Zn-VI materials with Cu 2O. Finally, We have addressed the typically high series resistance of Cu2O wafers by developing methods to make very thin, bulk Cu 2O, including devices on Cu2O wafers as thin as 20 microns. Using these methods we have been able to achieve photovoltages over 1 V, and have demonstrated the potential of a new heterojunction material, Zn(O,S).

  4. Density of Na2O-Li2O-SiO2-B2O3 Molten Slag at 1 803-1 873 K

    XIAO Feng; FANG Liang


    The density of three kinds of molten slags was measured by modified sessile drop method at 1 803-1 873 K. The density of molten slag is found to decrease with increasing temperature. The temperature coefficients of Na2O-Li2O-SiO2 and Li2O-SiO2-B2O3 slag are smaller than that of Na2O-B2O3 slag. The molar volume of slags increases with increasing temperature.

  5. Research on Y2O3:Eu Phosphor Coated with In2O3


    Y2O3:Eu red phosphor for FED application was prepared by high temperature solid-state reaction. The In2O3 coating by precipitation method to the phosphor was applied and the analyses of XRD, Zeta potential, SEM, EDS and low voltage cathodoluminescence (CL) were conducted for investigating the coating effect. The results showed that In2O3 coating promoted the low voltage CL of the phosphor efficiently. The promotion was possibly due to the enhancement of the surface conductivity of the phosphor grains.

  6. Cello-Oligosaccharide Oxidation Reveals Differences between Two Lytic Polysaccharide Monooxygenases (Family GH61) from Podospora anserina

    Bey, Mathieu; Zhou, Simeng; Poidevin, Laetitia; Henrissat, Bernard; Coutinho, Pedro M.; Berrin, Jean-Guy; Sigoillot, Jean-Claude


    The genome of the coprophilic ascomycete Podospora anserina encodes 33 different genes encoding copper-dependent lytic polysaccharide monooxygenases (LPMOs) from glycoside hydrolase family 61 (GH61). In this study, two of these enzymes (P. anserina GH61A [PaGH61A] and PaGH61B), which both harbored a family 1 carbohydrate binding module, were successfully produced in Pichia pastoris. Synergistic cooperation between PaGH61A or PaGH61B with the cellobiose dehydrogenase (CDH) of Pycnoporus cinnab...

  7. Failure of serotonin inhibitor to effect nocturnal GH and prolactin secretion in patients with Duchenne muscular dystrophy.

    Marlarkey, W B; Mendall, J R


    Growth hormone (GH) and prolactin (PRL) secretion was evaluated in seven patients with Duchenne muscular dystrophy. GH and PRL levels following sleep and 24 h mean serum GH and PRL concentrations were normal in these subjects. Overnight GH and PRL concentrations were evaluated in four of these patients before and following administration of the serotonin inhibitor, parachlorophenylalanine (PCPA). Although PCPA produced a significant decrease in urinary 5HIAA concentrations, the treatment had no significant effect on GH and PRL levels. These findings raise the possibility that serotonin may not be involved in nocturnal GH and PRL secretion in these patients.

  8. Epidermal cell differentiation in cotton mediated by the homeodomain leucine zipper gene, GhHD-1.

    Walford, Sally-Ann; Wu, Yingru; Llewellyn, Danny J; Dennis, Elizabeth S


    Gossypium hirsutum L. (cotton) fibres are specialized trichomes a few centimetres in length that grow from the seed coat. Few genes directly involved in the differentiation of these epidermal cells have been identified. These include GhMYB25-like and GhMYB25, two related MYB transcription factors that regulate fibre cell initiation and expansion. We have also identified a putative homeodomain leucine zipper (HD-ZIP) transcription factor, GhHD-1, expressed in trichomes and early fibres that might play a role in cotton fibre initiation. Here, we characterize GhHD-1 homoeologues from tetraploid G. hirsutum and show, using reporter constructs and quantitative real-time PCR (qRT-PCR), that they are expressed predominantly in epidermal tissues during early fibre development, and in other tissues bearing epidermal trichomes. Silencing of GhHD-1 reduced trichome formation and delayed the timing of fibre initiation. Constitutive overexpression of GhHD-1 increased the number of fibres initiating on the seed, but did not affect leaf trichomes. Expression of GhHD-1 in cotton silenced for different fibre MYBs suggest that in ovules it acts downstream of GhMYB25-like, but is unaffected in GhMYB25- or GhMYB109-silenced plants. Microarray analysis of silencing and overexpression lines of GhHD-1 indicated that it potentially regulates the levels of ethylene and reactive oxidation species (ROS) through a WRKY transcription factor and calcium-signalling pathway genes to activate downstream genes necessary for cell expansion and elongation. © 2012 CSIRO. The Plant Journal © 2012 Blackwell Publishing Ltd.

  9. Expression and functional characterization of intrafollicular GH-IGF system in the zebrafish ovary.

    Zhou, Rui; Yu, Susana Man Ying; Ge, Wei


    The somatotrophic axis plays important roles in influencing reproduction. All key members of this axis including growth hormone (GH, gh), GH receptors (ghra and ghrb), insulin-like growth factors (IGFs, igf1, igf2 and igf3) and IGF receptors (igf1ra and igf1rb) were detected in the zebrafish ovary. GH was exclusively expressed in the full-grown oocytes, while its receptors were detectable in both the follicle cells and oocytes. The IGFs and their receptors were all expressed in both compartments except igf3, which was expressed in the follicle cells only. During folliculogenesis, there was a sharp decrease of gh expression at follicle activation; however, the expression of its receptors increased significantly. The expression profiles of igf1, igf2a, and igf2b were similar to that of fshr, whereas igf3 expression was close to lhcgr, suggesting differential roles for different forms of IGFs in follicle development. To examine if the ovarian GH-IGF system is regulated by gonadotropins (e.g., hCG) and GH, we performed in vitro experiments using cultured zebrafish follicle cells. The expression of igf1 and igf1ra, but not others, was down-regulated by hCG (LH analog), whereas recombinant zebrafish GH stimulated igf1 expression. In addition, GH also increased the expression of activin βA subunit (inhbaa). In agreement with this, the stimulatory effect of GH but not IGF-I on oocyte maturation could be abolished by follistatin. In conclusion, the present study revealed an intrafollicular network involving GH-IGF mini-axis in the zebrafish ovary; however, it might not work in the same way as that of the systemic somatotrophic axis.

  10. Targeting GH-1 splicing as a novel pharmacological strategy for growth hormone deficiency type II.

    Miletta, Maria Consolata; Flück, Christa E; Mullis, Primus-E


    Isolated growth hormone deficiency type II (IGHD II) is a rare genetic splicing disorder characterized by reduced growth hormone (GH) secretion and short stature. It is mainly caused by autosomal dominant-negative mutations within the growth hormone gene (GH-1) which results in missplicing at the mRNA level and the subsequent loss of exon 3, producing the 17.5-kDa GH isoform: a mutant and inactive GH protein that reduces the stability and the secretion of the 22-kDa GH isoform, the main biologically active GH form. At present, patients suffering from IGHD II are treated with daily injections of recombinant human GH (rhGH) in order to reach normal height. However, this type of replacement therapy, although effective in terms of growth, does not prevent the toxic effects of the 17.5-kDa mutant on the pituitary gland, which may eventually lead to other hormonal deficiencies. As the severity of the disease inversely correlates with the 17.5-kDa/22-kDa ratio, increasing the inclusion of exon 3 is expected to ameliorate disease symptoms. This review focuses on the recent advances in experimental and therapeutic strategies applicable to treat IGHD II in clinical and preclinical contexts. Several avenues for alternative IGHD II therapy will be discussed including the use of small interfering RNA (siRNA) and short hairpin RNA (shRNA) constructs that specifically target the exon 3-deleted transcripts as well as the application of histone deacetylase inhibitors (HDACi) and antisense oligonucleotides (AONs) to enhance full-length GH-1 transcription, correct GH-1 exon 3 splicing and manipulate GH pathway.

  11. Timelike gamma* N -> Delta form factors and Delta Dalitz decay

    Ramalho, G


    We extend a covariant model, tested before in the spacelike region for the physical and lattice QCD regimes, to a calculation of the gamma* N -> Delta reaction in the timelike region, where the square of the transfered momentum, q^2, is positive (q^2>0). We estimate the Dalitz decay Delta -> Ne+e- and the Delta distribution mass distribution function. The results presented here can be used to simulate the NN -> NNe+e- reactions at moderate beam kinetic energies.

  12. Structural transition and orbital glass physics in near itinerant CoV2O4

    Reig-i-Plessis, D.; Casavant, D.; Garlea, V. O.; Aczel, A. A.; Feygenson, M.; Neuefeind, J.; Zhou, H. D.; Nagler, S.E.; MacDougall, G. J.


    The ferrimagnetic spinel $\\mathrm{CoV_2O_4}$ has been a topic of intense recent interest, both as a frustrated insulator with unquenched orbital degeneracy and as a near-itinerant magnet which can be driven metallic with moderate applied pressure. Here, we report on our recent neutron diffraction and inelastic scattering measurements on powders with minimal cation site disorder. Our main new result is the identification of a weak ($\\frac{\\Delta a}{a} \\sim 10^{-4}$), first order structural pha...

  13. Is increase in bone mineral content caused by increase in skeletal muscle mass/strength in adult patients with GH-treated GH deficiency?

    Klefter, Oliver; Feldt-Rasmussen, Ulla


    performed a systematic literature analysis, including 51 clinical trials published between 1996 and 2008, which had studied the development in muscle mass, muscle strength, BMD, and/or BMC in GH-treated adult GHD patients. RESULTS: GH therapy had an anabolic effect on skeletal muscle. The largest increase......OBJECTIVE: Adult patients with GH deficiency (GHD) are characterized by a reduced muscle mass, but also reduced bone mineral density (BMD) and content (BMC), which have been ascribed to GHD per se. The aim of this study was to investigate if changes in BMD/BMC in adult GHD patients could be due...... to a muscle modulating effect, and if treatment with GH would primarily increase muscle mass and strength with a secondary increase in BMD/BMC, thus supporting the present physiological concept that mass and strength of bones are mainly determined by dynamic loads from the skeletal muscles. METHOD: We...

  14. Gene expression of a truncated and the full-length growth hormone (GH) receptor in subcutaneous fat and skeletal muscle in GH-deficient adults

    Fisker, Sidse; Kristensen, K; Rosenfalck, A M


    the relationship of circulating GHBP and body composition to GHR and GHRtr gene expression. Eleven adult GH-deficient patients were studied before and after 4 months of GH substitution therapy. Abdominal fat obtained by liposuction and femoral muscle biopsies were taken at baseline and after 4 months. Gene...... expression of GHR and GHRtr in adipose tissue and skeletal muscle was determined and expressed relative to the expression of beta-actin. Gene expression of GHR in abdominal sc adipose tissue was not altered, whereas the expression of GHRtr increased significantly. In skeletal muscle inverse changes were seen...... in the expression of messenger ribonucleic acid (mRNA) levels for the two GH receptor forms: expression of GHR increased significantly, whereas mRNA levels for GHRtr decreased. As expected, body composition changed with reduction of body fat mass after 4 months of GH treatment. Levels of circulating GHBP decreased...

  15. Schottky contacts to In2O3

    H. von Wenckstern


    Full Text Available n-type binary compound semiconductors such as InN, InAs, or In2O3 are especial because the branch-point energy or charge neutrality level lies within the conduction band. Their tendency to form a surface electron accumulation layer prevents the formation of rectifying Schottky contacts. Utilizing a reactive sputtering process in an oxygen-containing atmosphere, we demonstrate Schottky barrier diodes on indium oxide thin films with rectifying properties being sufficient for space charge layer spectroscopy. Conventional non-reactive sputtering resulted in ohmic contacts. We compare the rectification of Pt, Pd, and Au Schottky contacts on In2O3 and discuss temperature-dependent current-voltage characteristics of Pt/In2O3 in detail. The results substantiate the picture of oxygen vacancies being the source of electrons accumulating at the surface, however, the position of the charge neutrality level and/or the prediction of Schottky barrier heights from it are questioned.

  16. Nb2O5 nanofiber memristor

    Grishin, A. M.; Velichko, A. A.; Jalalian, A.


    Non-woven bead-free 100 μm long and 80-200 nm in diameter highly crystalline orthorhombic T-Nb2O5 nanofibers were sintered by sol-gel assisted electrospinning technique. Electrical and dielectric spectroscopy tests of individual fibers clamped onto Pt coated Si substrate were performed using a spreading resistance mode of atomic force microscope. Reproducible resistive switching with ON-OFF resistance ratio as high as 2 × 104 has a bipolar character, starts with a threshold voltage of 0.8-1.7 V, and follows by continuous growth of conductivity. Resistive memory effect is associated with a voltage-driven accumulation/depletion of oxygen vacancies at Nb2O5/Pt cathode interface. Poole-Frenkel emission from the electronic states trapped at reduced NbOx complexes determines a shape of Nb2O5/Pt diode I-V characteristics. Simple thermodynamic model explains a threshold character of switching, relates experimentally observed characteristics in low and high resistive states, and gives a reasonable estimate of the concentration of oxygen vacancies.

  17. Formation of Two-dimensional Metal-water Framework Containing (H2O)2O Cluster

    SUN,Ya-Guang; DING,Fu; GU,Xiao-Fu; ZHANG,Wan-Zhong; WEI,De-Zhou; GAO,En-Jun


    [Cd(phen)2(male)(H2O)]·9.5H2O (1) has been synthesized by the reaction of Cd(NO3)2 with phen and male (phen= 1,10-phenanthroline, H2male=maleic acid) in a mixture solvent of ethanol and distilled water. The complex was characterized by elemental analysis, infrared spectrum and thermal gravimetric analyses. The crystal structure was determined by X-ray single-crystal diffraction. In 1, a novel 1D water chain containing water (H2O)20 cluster was formed. Further hydrogen bonding interaction between the water chain and [Cd(phen)2(male)(H2O)] constructs a unique metal-water 2D framework.

  18. Reaction of diphenyl diselenide with hydrogen peroxide and inhibition of delta-aminolevulinate dehydratase from rat liver and cucumber leaves

    M. Farina


    Full Text Available The interaction of the product of H2O2 and (PhSe2 with delta-aminolevulinate dehydratase (delta-ALA-D from mammals and plants was investigated. (PhSe2 inhibited rat hepatic delta-ALA-D with an IC50 of 10 µM but not the enzyme from cucumber leaves. The reaction of (PhSe2 with H2O2 for 1 h increased the inhibitory potency of the original compound and the IC50 for animal delta-ALA-D inhibition was decreased from 10 to 2 µM. delta-ALA-D from cucumber leaves was also inhibited by the products of reaction of (PhSe2 with H2O2 with an IC50 of 4 µM. The major product of reaction of (PhSe2 with H2O2 was identified as seleninic acid and produced an intermediate with a lambdamax at 265 nm after reaction with t-BuSH. These results suggest that the interaction of (PhSe2 with mammal delta-ALA-D requires the presence of cysteinyl residues in close proximity. Two cysteine residues in spatial proximity have been recently described for the mammalian enzyme. Analysis of the primary structure of plant delta-ALA-D did not reveal an analogous site. In contrast to (PhSe2, seleninic acid, as a result of the higher electrophilic nature of its selenium atom, may react with additional cysteinyl residue(s in mammalian delta-ALA-D and also with cysteinyl residues from cucumber leaves located at a site distinct from that found at the B and A sites in mammals. Although the interaction of organochalcogens with H2O2 may have some antioxidant properties, the formation of seleninic acid as a product of this reaction may increase the toxicity of organic chalcogens such as (PhSe2.

  19. Common exon 3 polymorphism of the GH receptor (GHR) gene and effect of GH therapy on growth in Korean children with idiopathic short stature (ISS).

    Ko, Jung Min; Park, Jung Young; Yoo, Han-Wook


    A human GH receptor (GHR) gene exon 3 polymorphism (d3-GHR) has been reported to be associated with responsiveness to GH therapy. We assessed the frequencies of this polymorphism in Korean control and idiopathic short stature (ISS) populations, and analysed short-term growth response to GH therapy according to GHR-exon 3 genotypes in Korean children with ISS. This was a retrospective study in 158 ISS children. Auxological and endocrine parameters were measured, and the GHR-exon 3 genotype was analysed. Allelic frequencies of GHR-exon 3 genotype were compared between the ISS group and a control group. GH had been administered for 62 patients, 52 of whom remained prepubertal after the first follow-up year. Changes in height velocity (HV) and IGF-1 and IGFBP-3 concentrations following GH therapy were compared in patients with these genotypes. There was no difference in GHR-exon 3 genotype frequency between ISS and control groups of Koreans. However, the fl/fl genotype was more frequent in Koreans than in Caucasians. ISS children with d3-GHR showed a significantly higher increment in HV (P = 0.002) and a marginally significant increment in IGF-1 concentration (P = 0.064) at the first year of GH therapy. fl-GHR was more frequently detected in a Korean population than in Caucasians. The growth promotion efficacy of GH therapy differed significantly between ISS patients with and without the d3-GHR allele. These findings indicate that the GHR-exon 3 polymorphism can affect the growth promoting efficacy of short-term GH therapy in Korean children with ISS.

  20. Effects of recombinant growth hormone (GH replacement and psychomotor and cognitive stimulation in the neurodevelopment of GH-deficient (GHD children with cerebral palsy: a pilot study

    Devesa J


    Full Text Available Jesús Devesa1,2, Begoña Alonso1, Nerea Casteleiro1, Paula Couto1, Beatriz Castañón1, Eva Zas1, Pedro Reimunde1,21Medical Center “Proyecto Foltra”, Cacheiras (Teo, A Coruña, Spain; 2Department of Physiology, School of Medicine, University of Santiago de Compostela, SpainAbstract: Cerebral palsy (CP is the main cause of physical disability in childhood and is an important health issue that has a strong socioeconomic impact. There is no effective treatment for CP and therapeutic approaches report only partial benefits for affected people. In this study we assessed the effects of growth hormone (GH treatment combined with psychomotor and cognitive stimulation in the neurodevelopment of children with CP and GH deficiency (GHD. The study was carried out in 11 patients (7 boys and 4 girls; 4.12 ± 1.31 years with GHD and CP who were treated with recombinant GH (rGH and psychomotor and cognitive stimulation during 2 months. Battelle Developmental Inventory Screening Test (BDIST was performed 2 months before commencing GH treatment, just before commencing GH administration, and after 2 months of combined treatment involving GH and cognitive stimulation. Psychomotor and cognitive status did not change during the period in which only cognitive stimulation was performed; however, significant improvements in personal and social skills, adaptive behavior, gross motor skills and total psychomotor abilities, receptive and total communication, cognitive skills and in the total score of the test (P < 0.01, and in fine motor skills and expressive communication (P < 0.02 were observed after the combined treatment period. Therefore, GH replacement together with psychomotor and cognitive stimulation seem to be useful for the appropriate neurodevelopment of children with GHD and CP.Keywords: growth hormone, cerebral palsy, cognitive functions, Battelle’s test, neurodevelopment

  1. Autocrine/paracrine proliferative effect of ovarian GH and IGF-I in chicken granulosa cell cultures.

    Ahumada-Solórzano, S Marisela; Martínez-Moreno, Carlos G; Carranza, Martha; Ávila-Mendoza, José; Luna-Acosta, José Luis; Harvey, Steve; Luna, Maricela; Arámburo, Carlos


    It is known that growth hormone (GH) and its receptor (GHR) are expressed in granulosa cells (GC) and thecal cells during the follicular development in the hen ovary, which suggests GH is involved in autocrine/paracrine actions in the female reproductive system. In this work, we show that the knockdown of local ovarian GH with a specific cGH siRNA in GC cultures significantly decreased both cGH mRNA expression and GH secretion to the media, and also reduced their proliferative rate. Thus, we analyzed the effect of ovarian GH and recombinant chicken GH (rcGH) on the proliferation of pre-hierarchical GCs in primary cultures. Incubation of GCs with either rcGH or conditioned media, containing predominantly a 15-kDa GH isoform, showed that both significantly increased proliferation as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, proliferating cell nuclear antigen (PCNA) quantification and ((3)H)-thymidine incorporation ((3)H-T) assays in a dose response fashion. Both, locally produced GH and rcGH also induced the phosphorylation of Erk1/2 in GC cultures. Furthermore, GH increased IGF-I synthesis and its release into the GC culture incubation media. These results suggest that GH may act through local IGF-I to induce GC proliferation, since IGF-I immunoneutralization completely abolished the GH-induced proliferative effect. These data suggest that GH and IGF-I may play a role as autocrine/paracrine regulators during the follicular development in the hen ovary at the pre-hierarchical stage.

  2. [In vitro MR imaging of Fe(2)O(3)-PLL labelled rabbit peripheral blood endothelial progenitor cells].

    Mai, Xiao-li; Teng, Gao-jun; Ma, Zhan-long; Sun, Jun-hui; Zhang, Yu; Gu, Ning


    To perform in vitro magnetic resonance imaging on magnetic iron oxide (Fe(2)O(3)-PLL) labeled rabbit peripheral blood endothelial progenitor cells (EPCs). Fe(2)O(3) was incubated with PLL for 2 hours to form Fe(2)O(3)-PLL. Rabbit peripheral blood mononuclear cells (MNCs) were isolated and EPCs were selected by adherence method, expanded and incubated with Fe(2)O(3)-PLL. Intracellular iron was detected by Prussian blue stain and under electron microscope. MTT assay was used to evaluate cell survival and proliferation of Fe(2)O(3)-PLL labeled EPCs. Flow cytometry was used to analysis cell cycle and apoptosis. The cells underwent in vitro MR imaging with various sequences. Iron-containing intracytoplasmatic vesicles could be observed clearly with Prussian blue staining and electron microscope observation. Survival, life cycle and apoptosis values obtained by MTT and flow cytometry analysis were similar among unlabelled EPCs and EPCs labeled with various concentrations Fe(2)O(3)-PLL. The signal intensity on MRI was significantly decreased in labeled cells compared with that in unlabeled cells. The percentage change in signal intensity (DeltaSI) was most significant on T(2)*WI and DeltaSI was significantly lower in cells labeled for 7 days than that labeled for 1 day. The rabbit peripheral blood EPCs can be labeled with Fe(2)O(3)-PLL without significant change in viability and proliferation. The labeled EPCs can be imaged with standard 1.5 T MR equipment. The degree of MR signal decreasing may indirectly reflect the cells count, growth state and division.

  3. Effect of Strong Basic Oxide (Li2O, Na2O, K2O and BaO) on Property of CaO-Based Flux

    LI Gui-rong


    It is found that strong basic oxides including Li2O, Na2O, K2O and BaO, which are used to replace a part of CaO in CaO-based fluxes, can lower the melting point and the viscosity and enhance the dephosphorizing ability. The mechanism was analysed and the addition of Li2O to CaO-based fluxes was recommended.

  4. Lithium insertion in V{sub 2}O{sub 5}, M{sub x}V{sub 2}O{sub 5} (M = Fe, Cr, Al, La) mixed oxides; Insertion du lithium dans les oxydes mixtes de V{sub 2}O{sub 5}, M{sub x}V{sub 2}O{sub 5} (M = Fe, Cr, Al, La)

    Gregoire, G.; Pecquenard, B.; Baffier, N. [Centre National de la Recherche Scientifique (CNRS), 75 - Paris (France). Laboratoire de Chimie Appliquee de l`Etat Solide; Soudan, P.; Farcy, J.; Pereira-Ramos, J.P. [Centre National de la Recherche Scientifique (CNRS), 94 - Ivry-sur-Seine (France). Laboratoire d`Electrochimie Catalyse et Synthese Organique


    V{sub 2}O{sub 5} based compounds are interesting low potential materials for rechargeable cathodes of lithium electrochemical generators. However, the ionic conductivity and the reversibility of electrochemical cycling of V{sub 2}O{sub 5} are limited by the possibilities of lithium insertion. This work shows that the doping of vanadium pentoxide by a M{sup 3+} trivalent transition element (M Fe, Al, Cr or La) allows to intercalate a more important amount of lithium and to improve the behaviour of the material during cycling. These materials of M{sub 0.11}V{sub 2}O{sub 5.16} formula are obtained by sol-gel synthesis. the electrochemical study of the Fe compound has shown that it is a mixed oxide with a behaviour similar to V{sub 2}O{sub 5}. The maximum capacity is of about 2 F/mole in the case of Fe, Al and Cr compounds and of about 1.7 F/mole in the case of La. The structural evolution of the Fe compound has been followed during the chemical insertion of Li and the same succession of phases ({alpha}, {epsilon}, {delta} and {gamma}) is observed as in Li{sub x}V{sub 2}O{sub 5} compounds but with a delay. The occurrence of the {gamma} phase, in particular, which is involved in recharging problems is delayed thanks to the (Fe-O){sub n} chains perpendicular to the (V{sub 2}O{sub 5}){sub n} layers. Abstract only. (J.S.) 3 refs.

  5. Unconventional exchange bias in CoCr2O4/Cr2O3 nanocomposites

    Guo, S.; Liu, X. H.; Cui, W. B.; Liu, W.; Zhao, X. G.; Li, D.; Zhang, Z. D.


    Unconventional exchange bias (EB) has been studied in CoCr2O4/Cr2O3 nanocomposites, in which the Curie temperature of the ferrimagnetic CoCr2O4 is much lower than the Néel temperature of the antiferromagnetic Cr2O3. A negative EB field of about 2.5 kOe at 5 K is achieved upon cooling in a field of 30 kOe. Meanwhile, the coercivity of the CoCr2O4 nanoparticles has been enhanced significantly by coupling with Cr2O3. The effect of the cooling field on the EB field and coercivity at 10 K has also been investigated. The domain-state model is used to interpret the unconventional EB. Cooling field may play a decisive role in the creation of the interfacial spin configuration for the unconventional EB, not only by exchange interaction between the induced magnetization of a polarized paramagnet and interfacial spins of an antiferromagnet but also by Zeeman interaction between the domain-state surplus magnetization and the external field.

  6. Interfacial-layers-free Ga2O3(Gd2O3)/Ge MOS Diodes

    Lee, C. H.; Lin, T. D.; Lee, K. Y.; Huang, M. L.; Tung, L. T.; Hong, M.; Kwo, J.


    High κ dielectric Ga2O3(Gd2O3) films were deposited directly on Ge by Molecular-Beam-Epitaxy without the employment of GeON interfacial layer. Excellent electrical properties, such as a high κ value of 14.5, a low leakage current density of only 3x10-9 A/cm^2 at Vfb+1V, and well-behaved CV characteristics, were demonstrated, even being subjected to a 500^oC annealing in N2 ambient for 5 min. An abrupt Ga2O3(Gd2O3)/Ge interface without any interfacial layer was revealed by high-resolution transmission electron microscopy as well as in-situ x-ray photoelectron spectroscopy (XPS). Detailed XPS studies indicate that the oxide/Ge interface consists of mainly Ge-O-Gd bonding, distinctly different from that of native oxide. Furthermore, the 500^oC annealing did not change the chemical bonding, implying a great thermodynamic stability of the hetero-structure. The outstanding electrical and thermodynamic properties qualified Ga2O3(Gd2O3) as a promising dielectric for Ge and proved the GeON interfacial layer to be unnecessary.

  7. Quality of porcine blastocysts produced in vitro in the presence of absence of GH

    Kidson, A.; Rubio-Pomar, F.J.; Knegsel, van A.; Tol, van H.T.A.; Hazeleger, W.; Ducro-Steverink, D.W.B.; Colenbrander, B.; Dieleman, S.J.; Bevers, M.M.


    GH receptor (GHR) mRNA is expressed in bovine in vitro produced embryos up to the blastocyst stage and GH improves the quality of bovine embryos by increasing blastocyst cell numbers and reducing the incidence of apoptosis as evaluated by DNA strand-break labelling. Porcine in vitro produced blastoc

  8. Substrate Metabolism and Insulin Sensitivity During Fasting in Obese Human Subjects: Impact of GH Blockade.

    Pedersen, Morten Høgild; Svart, Mads Vandsted; Lebeck, Janne; Bidlingmaier, Martin; Stødkilde-Jørgensen, Hans; Pedersen, Steen Bønløkke; Møller, Niels; Jessen, Niels; Jørgensen, Jens O L


    Insulin resistance and metabolic inflexibility are features of obesity and are amplified by fasting. Growth hormone (GH) secretion increases during fasting and GH causes insulin resistance. To study the metabolic effects of GH blockade during fasting in obese subjects. Nine obese males were studied thrice in a randomized design: (1) after an overnight fast (control), (2) after 72 hour fasting (fasting), and (3) after 72 hour fasting with GH blockade (pegvisomant) [fasting plus GH antagonist (GHA)]. Each study day consisted of a 4-hour basal period followed by a 2-hour hyperinsulinemic, euglycemic clamp combined with indirect calorimetry, assessment of glucose and palmitate turnover, and muscle and fat biopsies. GH levels increased with fasting (P fasting-induced reduction of serum insulin-like growth factor I was enhanced by GHA (P Fasting increased lipolysis and lipid oxidation independent of GHA, but fasting plus GHA caused a more pronounced suppression of lipid intermediates in response to hyperinsulinemic, euglycemic clamp. Fasting-induced insulin resistance was abrogated by GHA (P Fasting plus GHA also caused elevated glycerol levels and reduced levels of counterregulatory hormones. Fasting significantly reduced the expression of antilipolytic signals in adipose tissue independent of GHA. Suppression of GH activity during fasting in obese subjects reverses insulin resistance and amplifies insulin-stimulated suppression of lipid intermediates, indicating that GH is an important regulator of substrate metabolism, insulin sensitivity, and metabolic flexibility also in obese subjects.

  9. Expression and ontogeny of growth hormone (Gh) in the protogynous hermaphroditic ricefield eel (Monopterus albus).

    Chen, Dong; Liu, Jiang; Chen, Wanping; Shi, Shuxia; Zhang, Weimin; Zhang, Lihong


    Growth hormone (GH) is a single-chain polypeptide hormone mainly secreted by somatotropes of the anterior pituitary gland and is an important regulator of somatic growth in vertebrates including teleosts. In this study, a polyclonal antiserum against ricefield eel Gh was generated and the expression of Gh at the mRNA and protein levels was analyzed. Both RT-PCR and western blot analysis showed that Gh was predominantly expressed in the pituitary glands of ricefield eels. The immunoreactive Gh signals were localized to the multicellular layers of the adenohypophysis adjacent to the neurohypophysis in ricefield eels. Ontogenetic analysis showed that immunoreactive Gh signals could be detected in the pituitary glands of ricefield eel embryos as early as 3 days post-fertilization. During the sex change from female to male, the levels of the immunoreactive Gh signals in the pituitary glands of the ricefield eels peaked at the intersexual stage. These results suggest that Gh in the pituitary glands may be associated with embryonic development before hatching, as well as with the sex change in the adult ricefield eels, possibly via the classical endocrine manner.

  10. Data of evolutionary structure change: 1GH4A-2NOTA [Confc[Archive

    Full Text Available 1GH4A-2NOTA 1GH4 2NOT A A ALWQFNGMIKCKI-PSSEPLLDFNNYGCYCGLGGSGTPV...pdbChain>A 2NOTA GRRPT-RHYMD tion> -0.38999998569488525 0.11299999803304...28 0.8849999904632568 -0.22699999809265137 -0.4059999883174896 tion> 0.9489870071411133 1.493407964706421 ...

  11. Perinatal growth and plasma GH profiles in adolescent and adult sheep.

    Gatford, K L; Clarke, I J; De Blasio, M J; McMillen, I C; J S Robinson; Owens, J A


    Poor prenatal growth is associated with limited evidence of GH deficiency in adult humans, which may contribute to their increased risk of cardiovascular and metabolic disease. We therefore examined the effects of placental restriction of fetal growth (PR) on size at birth, neonatal fractional growth rate (FGR) and the circulating GH profile in adolescent and young adult sheep of both sexes. Moderate or severe PR decreased birth size and increased neonatal FGR of weight, crown-rump length and abdominal circumference. In adolescent males, mean and baseline GH concentrations correlated negatively and independently with birth weight and FGR of weight, and mean GH concentrations correlated negatively with current weight. In young adult males, mean GH concentrations correlated negatively and independently with birth shoulder height and FGR of shoulder height whilst, in young adult females, these correlations were positive. This suggests that restricted fetal growth and reduced neonatal growth rate in sheep are followed by elevated circulating GH in adolescent and adult males, but GH deficiency or increased GH clearance in adult females.

  12. Effects of a physiological GH pulse on interstitial glycerol in abdominal and femoral adipose tissue

    Gravhølt, C H; Schmitz, Ole; Simonsen, L


    Physiologically, growth hormone (GH) is secreted in pulses with episodic bursts shortly after the onset of sleep and postprandially. Such pulses increase circulating levels of free fatty acid and glycerol. We tested whether small GH pulses have detectable effects on intercellular glycerol...

  13. CT scan in diagnosis of pituitary adenomas, 5. CT findings of GH secreting adenomas

    Sakoda, K.; Yonezawa, M.; Gen, M. (Hiroshima Univ. (Japan). School of Medicine)


    Clinical findings and radiological findings in 19 cases of GH secreting adenoma were reported. In diagnosis of GH secreting adenoma, conventional radiography and computed tomography of the sella turcica are useful. The CT of this kind of adenomas shows a characteristically higher x-ray absorption coefficient than other adenomas.

  14. From isolated GH deficiency to multiple pituitary hormone deficiency: an evolving continuum - a KIMS analysis

    Klose, M.; Jonsson, B.; Abs, R.;


    with organic AO-GHD, who were GH naive prior to entry into the Pfizer International Metabolic Database (KIMS; 283 (7%) IGHD, 3827 MPHD). The effect of GH replacement after 2 years was assessed in those with available follow-up data (133 IGHD, 2207 MPHD), and development of new deficiencies in those...

  15. Evolution, homology conservation, and identification of unique sequence signatures in GH19 family chitinases.

    Udaya Prakash, N A; Jayanthi, M; Sabarinathan, R; Kangueane, P; Mathew, Lazar; Sekar, K


    The discovery of GH (Glycoside Hydrolase) 19 chitinases in Streptomyces sp. raises the possibility of the presence of these proteins in other bacterial species, since they were initially thought to be confined to higher plants. The present study mainly concentrates on the phylogenetic distribution and homology conservation in GH19 family chitinases. Extensive database searches are performed to identify the presence of GH19 family chitinases in the three major super kingdoms of life. Multiple sequence alignment of all the identified GH19 chitinase family members resulted in the identification of globally conserved residues. We further identified conserved sequence motifs across the major sub groups within the family. Estimation of evolutionary distance between the various bacterial and plant chitinases are carried out to better understand the pattern of evolution. Our study also supports the horizontal gene transfer theory, which states that GH19 chitinase genes are transferred from higher plants to bacteria. Further, the present study sheds light on the phylogenetic distribution and identifies unique sequence signatures that define GH19 chitinase family of proteins. The identified motifs could be used as markers to delineate uncharacterized GH19 family chitinases. The estimation of evolutionary distance between chitinase identified in plants and bacteria shows that the flowering plants are more related to chitinase in actinobacteria than that of identified in purple bacteria. We propose a model to elucidate the natural history of GH19 family chitinases.

  16. Effects of GH on protein metabolism during dietary restriction in man.

    Nørrelund, Helene; Riis, Anne Lene; Møller, Niels


    The metabolic response to dietary restriction involves a series of hormonal and metabolic adaptations leading to protein conservation. An increase in the serum level of growth hormone (GH) during fasting has been well substantiated. GH has potent protein anabolic actions, as evidenced by a significant decrease in lean body mass and muscle mass in chronic GH deficiency, and vice versa in patients with acromegaly. The present review outlines current knowledge about the role of GH in the metabolic response to fasting, with particular reference to the effects on protein metabolism. Physiological bursts of GH secretion seem to be of seminal importance for the regulation of protein conservation during fasting. Apart from the possible direct effects of GH on protein dynamics, a number of additional anabolic agents, such as insulin, insulin-like growth factor-I, and free fatty acids (FFAs), are activated. Taken together the effects of GH on protein metabolism seem to include both stimulation of protein synthesis and inhibition of breakdown, depending on the nature of GH administration, which tissues are being studied, and on the physiological conditions of the subjects.

  17. Growth hormone (GH) treatment increases serum insulin-like growth factor binding protein-3, bone isoenzyme alkaline phosphatase and forearm bone mineral content in young adults with GH deficiency of childhood onset

    Juul, A; Pedersen, S A; Sørensen, S


    Recent studies have demonstrated that growth hormone (GH)-deficient adults have a markedly decreased bone mineral content compared to healthy adults. However, there are conflicting results regarding the effects of GH treatment on bone mineral content in GH-deficient adults. Therefore, we evaluated...... the effect of GH treatment on a marker of bone formation (bone alkaline phosphatase), hepatic excretory function and distal forearm bone mineral content in GH-deficient adults. Growth hormone was administered subcutaneously in 21 adults (13 males and 8 females) with GH deficiency of childhood onset for 4...... months in a double-blind, placebo-controlled GH trial, while 13 of the patients then received further GH for an additional 14 months. Serum insulin-like growth factor I (IGF-I) increased significantly from 100 to 279 micrograms/l and IGF binding protein-3 (IGFBP-3) from 1930 to 3355 micrograms/l after 4...

  18. Al2O3 Passivation on c-si Surfaces for Low Temperature Solar Cell Applications

    Saynova, D.S.; Janssen, G.J.M.; Burgers, A.R.; Mewe, A.A. [ECN Solar Energy, Westerduinweg 3, NL-1755 LE Petten (Netherlands); Cianci, E.; Seguini, G.; Perego, M. [Laboratorio MDM, IMM-CNR, Via C. Olivetti 2,I-20864 Agrate Brianza MB (Italy)


    Functional passivation of high resistivity p-type c-Si wafer surfaces was achieved using 10 nm Al2O3 layers and low temperatures for both the thermal ALD process and post-deposition anneal. Effective lifetime values higher than 1 ms were measured at excess carrier density {delta}n=1015 cm{sup -3}. This result was reached in combination with temperatures of 100C and 200C for the Al2O3 layer deposition and anneal, respectively. The Al2O3/c-Si interface was characterized using conductance-voltage and capacitance-voltage measurements. In particular, significantly reduced interface density of the electrically active defects Dit {approx} 2x1010 eV{sup -1}cm{sup -2} was detected, which enabled excellent chemical passivation. The measured density of fixed charges at the interface, Qf, after anneal were in the range +1x10{sup 12} to -1x10{sup 12} cm{sup -2} indicating that both inversion and accumulation conditions result in relevant field-effect passivation using Al2O3 layers and low temperature processes. Numerical simulations on representative test structures show that the uniform Qf effect can be understood in terms of a surface damage region (SDR) present near the interface in combination with asymmetry in the lifetime of holes and electrons in the SDR. The combination of low processing temperatures, thin layers and good passivation properties facilitate a technology for future low temperature solar cell applications.

  19. Growth hormone (GH) substitution in GH-deficient patients inhibits 11beta-hydroxysteroid dehydrogenase type 1 messenger ribonucleic acid expression in adipose tissue.

    Paulsen, Søren Kildeberg; Pedersen, Steen Bønløkke; Jørgensen, Jens Otto Lunde; Fisker, Sanne; Christiansen, Jens Sandahl; Flyvbjerg, Allan; Richelsen, Bjørn


    Local tissue activity of glucocorticoids is in part determined by the isoenzymes 11beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1) and 11beta-HSD2, interconverting inert cortisone and active cortisol. Increased tissue activity of cortisol may play a central role in the features of GH deficiency and the metabolic syndrome. We investigated the effects of GH treatment on adipose tissue 11beta-HSD mRNA. A randomized placebo-controlled double-blind study design was used. Twenty-three GH-deficient patients (16 males and seven females) were randomized to 4 months of GH treatment (2 IU/m2) (n = 11) or placebo treatment (n = 12). Adipose tissue biopsies and blood samples were obtained before and after treatment. Biopsies were obtained from the abdominal sc depot at the level of the umbilicus and do not necessarily reflect the metabolically more important visceral adipose tissue. Gene expressions were determined by real-time RT-PCR. GH treatment decreased 11beta-HSD1 mRNA 66% [95% confidence interval (CI), 23-107%; P adipose tissue. Serum IGF-I and IGF-I mRNA increased in the GH-treated group by 187% (95% CI, 122-250%; P cortisol in adipose tissue.

  20. Delta II commercial space transportation

    Meyers, J. F.


    Delta II is an upgraded variant of the Delta family of launch vehicles that has been in use by NASA since 1960. Among the design improvements incorporated by Delta II is a cryogenic-propellant second stage, a 2.89-m diameter satellite-protecting nose fairing, graphite/epoxy solid rocket motor cases, and 12:1 main engine expansion nozzle. The manufacturer/operator offers Delta II customers a dedicated, single satellite launch capability fully tailored to the given spacecraft's unique mission requirements.

  1. Natural history of the classical form of primary growth hormone (GH) resistance (Laron syndrome).

    Laron, Z


    A description of the clinical, biochemical and endocrinological features of the classical form of the syndrome of primary growth hormone (GH) resistance (Laron syndrome) is presented including the progressive changes during follow-up from infancy into adulthood. The main diagnostic features are: severe growth retardation, acromicria, small gonads and genitalia, and obesity. Serum GH levels are elevated and insulin-like growth factor-I (IGF-I) values are low and do not rise upon stimulation by exogenous hGH. The pathogenesis of this syndrome is due to various molecular defects from exon deletion to nonsense, frameshift, splice and missense mutations in the GH receptor (GH-R) gene or in its post-receptor pathways.

  2. Pharmacological activation of the GABAergic system does not affect GH and PRL release in acromegaly.

    Orio, F; Iovino, M; Monteleone, P; Agrusta, M; Steardo, L; Lombardi, G


    An extensive hypothalamic neurotransmitter impairment has been proposed in acromegaly. However, at the moment, the hypothalamic GABAergic system has been little investigated in this disorder. Since GABA has been shown to modulate growth hormone (GH) and prolactin (PRL) secretion in human subjects, it seemed reasonable to investigate hypothalamic GABAergic functioning through the assessment of basal GH and PRL responses to pharmacological activation of this system. 800 mg of sodium valproate (SV), a drug with GABA facilitating properties, were administered orally to 7 acromegalic patients and 9 healthy volunteers. Blood samples were collected before and after the drug administration for the measurement of plasma GH and PRL levels. SV induced a clear-cut rise in basal GH and a decrease in basal PRL in healthy subjects, but it did not induce any change in the basal levels of these hormones in acromegalics. These results suggest that the response of GH and PRL to SV in acromegaly is qualitatively different from normal controls.

  3. Effects of fulvestrant on biological activity and Wnt expression in rat GH3 cells

    Jiwei Bai; Yan Wang; Chuzhong Li; Yazhuo Zhang


    The present study investigated the influence of anti-estrogen treatment (fulvestrant) on pituitary adenoma cell line GH3 biological activity, the estrogen receptor α pathway, the WnT pathway, and mechanisms of decreased Wnt inhibitory factor-1 expression in GH3 cells. Results showed that fulvestrant suppressed GH3 cell proliferation and reduced hormone secretion in a dose-dependent manner. Estrogen receptor α and Wnt4 expression decreased, but Wnt inhibitory factor-1 expression increased in a dose-dependent manner following fulvestrant treatment, and β-catenin expression remained unchanged. Inhibitors of DNA methylation and histone modification upregulated Wnt inhibitory factor-1 expression. Results suggested that fulvestrant suppressed biological activity of GH3 cells via the estrogen receptor α and Wnt pathways. These results suggested that decreased Wnt inhibitory factor-1 expression in GH3 cells played a role in epigenetic mechanisms. Anti-estrogen therapies could provide novel treatments for growth hormone adenomas.

  4. [Chronic renal failure and growth hormone: effects on GH-IGF axis and leptin].

    Oliveira, Josenilson C de; Machado Neto, Francisco de A; Morcillo, André Moreno; Oliveira, Laurione C de; Belangero, Vera Maria S; Geloneze Neto, Bruno; Tambascia, Marcos Antonio; Guerra-Júnior, Gil


    To analyze the changes in IGF-1, IGFBP-3, leptin and insulin after replacement doses of recombinant human growth hormone (rhGH) in short prepubertal children with chronic renal failure (CRF). Eleven children (3F:8M), with mean age of 9.6 years, were treated with rhGH (0.23 mg/Kg weekly for 12 months). Serum leptin, insulin, glucose, IGF-1 and IGFBP-3 were measured before, 6 and 12 months after beginning rhGH treatment. The serum levels of leptin, insulin and glucose did not vary during the treatment; normal leptin and glucose levels and high insulin were observed. There was a significant increment of IGF-1 and IGFBP-3 during the use of rhGH. The replacement doses of rhGH during 12 months in a selected group of CRF children determined an increment in IGF-1 and IGFBP-3, associated to normal serum leptin and insulin resistance.

  5. Preparation of dense nanocrystalline Bi{sub 2}O{sub 3}-HfO{sub 2}-Y{sub 2}O{sub 3} ceramic by microwave plasma sintering

    Zhen Qiang [Nano-Science and Nano-Technology Research Center, School of Materials Science and Engineering, Shanghai University, Shanghai 200444 (China)]. E-mail:; Vannier, Rose Noelle [Laboratoire de Cristallochimie et Physicochimie du Solide, UPRESA-CNRS 8012 ENSCL-USTL, BP 108, 59652 Villeneuve d' Ascq Cedex (France); Kale, Girish M. [Institute for Materials Research, University of Leeds, Leeds LS2 9JT (United Kingdom)


    Processing of nanocrystalline Bi{sub 2}O{sub 3}-HfO{sub 2}-Y{sub 2}O{sub 3} ceramic having high density has been investigated and reported in this paper. Nanopowders of mixed bismuth oxide, hafnia and yttrium oxide have been prepared by a reverse titration chemical coprecipitation from Bi{sup 3+}, Hf{sup 4+} and Y{sup 3+} containing aqueous solution. The high density, nanocrystalline Bi{sub 2}O{sub 3}-HfO{sub 2}-Y{sub 2}O{sub 3} ceramic has been synthesized by microwave plasma sintering. The XRD results of grain growth behavior indicates that growth of both {delta}-Bi{sub 2}O{sub 3} and c-HfO{sub 2} crystallites obeys the parabolic rate law, expressed as (D-D {sub 0}){sup 2} = Kt, during sintering process. After sintering at 700 deg. C for 60 min, the relative density of the samples sintered by microwave plasma has been found to be greater than 97%, and the samples exhibit considerably finer microstructure with an average size between 60 and 70 nm and equiaxed morphology and better density comparing with that of samples sintered by conventional pressureless sintering. In addition, mechanical properties of nanocrystalline Bi{sub 2}O{sub 3}-HfO{sub 2}-Y{sub 2}O{sub 3} ceramic has been improved greatly compareing with nanocrystalline Bi{sub 2}O{sub 3}-Y{sub 2}O{sub 3} ceramic.

  6. Solute atom migration in GH4169 superalloy under electrostatic fields

    Yao Wang; Lei Wang; Yang Liu; Xiu Song; Bei-jiang Zhang; Jin-hui Du


    Electric field treatment (EFT) was applied on GH4169 alloy during aging at 500-800◦C to investigate the microstructure and property variation of the alloy under the action of EFT. The results demonstrate that the short-distance diff usion of Al, Ti, and Nb atoms can be accelerated by EFT, which results in the coarsening ofγ ? andγ ?? phases. Meanwhile, lattice distortion can be caused by the segregation of Fe and Cr atoms, owing to the vacancy flows migrating toward the charged surfaces of the alloy. Therefore, the alloy is hardened by the application of EFT, even if the strength of the alloy is partly reduced, which is caused by precipitation coarsening.

  7. Tensile Strain Hardening Behavior and Fractography of Superalloy GH39

    WANG Hui


    Full Text Available The strain hardening behaviour and fractography of superalloy GH39 was investigated by tensile test at different strain rates. Results indicate that strain hardening behaviours are different during the deformation process. True stress-strain curve obeys the Hollomon relationship partly. The strain hardening exponentn in this stage is constant in the initial plastic stage. However, the value of n increased with true strain ε increasing when true strain is between 0.014 and 0.13. A lot of deformation twinning can be found, the twins and dislocations worked together to increase the value of n. The strain hardening exponent is increased lightly with the strain rate increasing, SEM observations show that in the case of low strain rate, the fracture mode is typical ductile, but there is a tendency from ductile to brittle fracture with increasing the strain rate.

  8. Effects of Double Transgenesis of Somatotrophic Axis (GH/GHR) on Skeletal Muscle Growth of Zebrafish (Danio rerio).

    Silva, Ana Cecilia Gomes; Almeida, Daniela Volcan; Nornberg, Bruna Felix; Figueiredo, Marcio Azevedo; Romano, Luis Alberto; Marins, Luis Fernando


    Transgenic fish for growth hormone (GH) has been considered as a potential technological improvement in aquaculture. In this study, a double-transgenic zebrafish was used to evaluate the effect of GH and its receptor (GHR) on muscle growth. Double transgenics reached the same length of GH transgenic, but with significantly less weight, featuring an unbalanced growth. The condition factor of GH/GHR-transgenic fish was lower than the other genotypes. Histological analysis showed a decrease in the percentage of thick muscle fibers in GH/GHR genotype of ∼ 80% in comparison to GH-transgenic line. The analysis of gene expression showed a significant decrease in genes related to muscle growth in GH/GHR genotype. It seems that concomitant overexpression of GH and GHR resulted in a strong decrease of the somatotrophic axis intracellular signaling by diminishing its principal transcription factor signal transducer and activator of transcription 5.1 (STAT5.1).

  9. MgAl2O4–-Al2O3 solid solution interaction: mathematical framework and phase separation of -Al2O3 at high temperature

    Soumen Pal; A K Bandyopadhyay; S Mukherjee; B N Samaddar; P G Pal


    Although existence of MgAl2O4–-Al2O3 solid solution has been reported in the past, the detailed interactions have not been explored completely. For the first time, we report here a mathematical framework for the detailed solid solution interactions of -Al2O3 in MgAl2O4 (spinel). To investigate the solid solubility of -Al2O3 in MgAl2O4, Mg–Al spinel (MgO–Al2O3; = 1, 1.5, 3, 4.5 and an arbitrary high value 30) precursors have been heat treated at 1000°C. Presence of only non-stoichiometric MgAl2O4 phase up to = 4.5 at 1000°C indicates that alumina (as -Al2O3) present beyond stoichiometry gets completely accommodated in MgAl2O4 in the form of solid solution. → alumina phase transformation and its subsequent separation from MgAl2O4 has been observed in the Mg–Al spinel powders ( > 1) when the 1000°C heat treated materials are calcined at 1200°C. In the mathematical framework, unit cell of MgAl2O4 (Mg8Al16O32) has been considered for the solid solution interactions (substitution of Mg2+ ions by Al3+ ions) with -Al2O3. It is suggested that combination of unit cells of MgAl2O4 takes part in the interactions when > 5 (MgO–Al2O3).

  10. Downregulation of the ACE2/Ang-(1-7)/Mas axis in transgenic mice overexpressing GH.

    Muñoz, Marina C; Burghi, Valeria; Miquet, Johanna G; Giani, Jorge F; Banegas, Ricardo D; Toblli, Jorge E; Fang, Yimin; Wang, Feiya; Bartke, Andrzej; Dominici, Fernando P


    The renin-angiotensin system (RAS) plays a crucial role in the regulation of physiological homeostasis and diseases such as hypertension, coronary artery disease, and chronic renal failure. In this cascade, the angiotensin-converting enzyme (ACE)/angiotensin II (Ang II)/AT1 receptor axis induces pathological effects, such as vasoconstriction, cell proliferation, and fibrosis, while the ACE2/Ang-(1-7)/Mas receptor axis is protective for end-organ damage. The altered function of the RAS could be a contributing factor to the cardiac and renal alterations induced by GH excess. To further explore this issue, we evaluated the consequences of chronic GH exposure on the in vivo levels of Ang II, Ang-(1-7), ACE, ACE2, and Mas receptor in the heart and the kidney of GH-transgenic mice (bovine GH (bGH) mice). At the age of 7-8 months, female bGH mice displayed increased systolic blood pressure (SBP), a high degree of both cardiac and renal fibrosis, as well as increased levels of markers of tubular and glomerular damage. Angiotensinogen abundance was increased in the liver and the heart of bGH mice, along with a concomitant increase in cardiac Ang II levels. Importantly, the levels of ACE2, Ang-(1-7), and Mas receptor were markedly decreased in both tissues. In addition, Ang-(1-7) administration reduced SBP to control values in GH-transgenic mice, indicating that the ACE2/Ang-(1-7)/Mas axis is involved in GH-mediated hypertension. The data indicate that the altered expression profile of the ACE2/Ang-(1-7)/Mas axis in the heart and the kidney of bGH mice could contribute to the increased incidence of hypertension, cardiovascular, and renal alterations observed in these animals.

  11. GH and Pituitary Hormone Alterations After Traumatic Brain Injury.

    Karaca, Züleyha; Tanrıverdi, Fatih; Ünlühızarcı, Kürşad; Kelestimur, Fahrettin


    Traumatic brain injury (TBI) is a crucially important public health problem around the world, which gives rise to increased mortality and is the leading cause of physical and psychological disability in young adults, in particular. Pituitary dysfunction due to TBI was first described 95 years ago. However, until recently, only a few papers have been published in the literature and for this reason, TBI-induced hypopituitarism has been neglected for a long time. Recent studies have revealed that TBI is one of the leading causes of hypopituitarism. TBI which causes hypopituitarism may be characterized by a single head injury such as from a traffic accident or by chronic repetitive head trauma as seen in combative sports including boxing, kickboxing, and football. Vascular damage, hypoxic insult, direct trauma, genetic predisposition, autoimmunity, and neuroinflammatory changes may have a role in the development of hypopituitarism after TBI. Because of the exceptional structure of the hypothalamo-pituitary vasculature and the special anatomic location of anterior pituitary cells, GH is the most commonly lost hormone after TBI, and the frequency of isolated GHD is considerably high. TBI-induced pituitary dysfunction remains undiagnosed and therefore untreated in most patients because of the nonspecific and subtle clinical manifestations of hypopituitarism. Treatment of TBI-induced hypopituitarism depends on the deficient anterior pituitary hormones. GH replacement therapy has some beneficial effects on metabolic parameters and neurocognitive dysfunction. Patients with TBI without neuroendocrine changes and those with TBI-induced hypopituitarism share the same clinical manifestations, such as attention deficits, impulsion impairment, depression, sleep abnormalities, and cognitive disorders. For this reason, TBI-induced hypopituitarism may be neglected in TBI victims and it would be expected that underlying hypopituitarism would aggravate the clinical picture of TBI

  12. Alterations in Oxygen Consumption, Respiratory Quotient, and Heat Production in Long-Lived GHRKO and Ames Dwarf Mice, and Short-Lived bGH Transgenic Mice

    Westbrook, Reyhan; Bonkowski, Michael S.; Strader, April D.; Bartke, Andrzej


    Growth hormone (GH) signaling influences longevity in mice, with decreased GH signaling associated with longer life span and increased GH signaling with shortened life span. A proposed mechanism through which GH signaling influences life span postulates that decreased GH signaling lowers metabolic rate, thus slowing aging by decreasing production of damaging free radicals. The influence of altered GH signaling on metabolism was tested by monitoring oxygen consumption (VO2), respiratory quotie...

  13. Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

    Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR


    Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia

  14. Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

    Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR


    Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia wh

  15. Peat compaction in deltas : implications for Holocene delta evolution

    van Asselen, S.|info:eu-repo/dai/nl/304838101


    Many deltas contain substantial amounts of peat, which is the most compressible soil type. Therefore, peat compaction potentially leads to high amounts of subsidence in deltas. The main objective of this research was to quantify subsidence due to peat compaction in Holocene fluvial-deltaic settings

  16. Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

    Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR


    Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia wh

  17. Growth hormone (GH) provocative retesting of 108 young adults with childhood-onset GH deficiency and the diagnostic value of insulin-like growth factor I (IGF-I) and IGF-binding protein-3

    Juul, A; Kastrup, K W; Pedersen, S A


    .e. 45% of patients treated with GH during childhood because of isolated GHD had a normal GH response when retested in adulthood. Multiple regression analysis revealed that peak GH levels were dependent on the degree of hypopituitarism, body mass index, and duration of disease. IGF-I levels were below -2...

  18. Carbohydrate metabolism during long-term growth hormone (GH) treatment and after discontinuation of GH treatment in girls with Turner syndrome participating in a randomized dose-response study. Dutch Advisory Group on Growth Hormone

    T.C.J. Sas (Theo); S.M.P.F. de Muinck Keizer-Schrama (Sabine); Th. Stijnen (Theo); H-J. Aanstoot (Henk-Jan); S.L.S. Drop (Stenvert)


    textabstractTo assess possible side-effects of GH treatment with supraphysiological doses on carbohydrate (CH) metabolism in girls with Turner syndrome (TS) during long term GH treatment and after discontinuation of GH treatment, the results of oral glucose tolerance

  19. Differential effects of central and peripheral administration of growth hormone (GH) and insulin-like growth factor on hypothalamic GH-releasing hormone and somatostatin gene expression in GH-deficient dwarf rats.

    Sato, M; Frohman, L A


    The roles of GH and insulin-like growth factor-I (IGF-I) in the regulation of hypothalamic GH-releasing hormone (GRH) and somatostatin (SRIH) gene expression were investigated in the GH-deficient dwarf (dw) rat, in which endogenous feedback signals are lacking. Adult male and female dw rats were treated with GH or IGF-I by systemic (sc) administration or intracerebroventricular (icv) infusion, and hypothalamic GRH and SRIH mRNA were determined by Northern blotting and densitometric analysis. Systemic sc injection of rGH (75 micrograms every 12 h for 3 days) decreased GRH mRNA levels in both sexes. However, systemic sc injection of human IGF-I (150 micrograms every 12 h for 3 days) did not affect GRH mRNA levels in either sex despite significant stimulation of body weight gain. The use of a continuous sc infusion, which normalized serum IGF-I levels, and prolongation of the treatment period to 7 days also failed to change GRH mRNA levels. SRIH mRNA was unaffected by systemic administration of either GH or IGF-I. Continuous icv infusion of GH (1 microgram/h for 7 days) decreased GRH mRNA levels in both sexes, but did not alter SRIH mRNA levels. Continuous icv infusion of IGF-I (100 ng/h for 7 days) decreased GRH mRNA in both sexes. In contrast, SRIH mRNA levels were increased in both sexes. IGF-I decreased GRH mRNA levels at icv infusion rates of 100 and 300 ng/h and stimulated SRIH mRNA levels at infusion rates of 30 and 100 ng/h. Food intake was unaffected at these infusion rates. Changes in GRH and SRIH mRNA levels in response to systemic or central GH and IGF-I administration were similar in both sexes, except that the decrease in GRH mRNA levels produced by the icv infusion of IGF-I was greater in female than in male rats. The results provide evidence for a direct inhibitory feedback effect of GH in the central nervous system on the regulation of hypothalamic GRH gene expression that is independent of peripheral IGF-I. IGF-I feedback, in contrast, appears to

  20. Defect structure of zirconium oxide nanosized powders with Y2O3, Sc2O3, Cr2O3 impurities

    Yurchenko, L.; I. Bykov; Vasylyev, A; Vereshchak, V.; Suchaneck, G.; Jastrabik, L.; Dejneka, A.


    Formation mechanisms of paramagnetic centers originating from Zr3+ and Cr3+ ions as well as the influence of composition of nanoparticles on thermogeneration processes of these paramagnetic centers in ZrO2 structure were studied. A set of nanosized powders of zirconium oxide was investigated by electron paramagnetic resonance method: nominally pure ZrO2; ZrO2 with Y2O3 and Sc2O3; ZrO2 with Cr2O3; ZrO2 with Y2O3 and Cr2O3. It is observed that the influence of annealing on EPR lines of Zr...

  1. Molecular engineering of fungal GH5 and GH26 beta-(1,4-mannanases toward improvement of enzyme activity.

    Marie Couturier

    Full Text Available Microbial mannanases are biotechnologically important enzymes since they target the hydrolysis of hemicellulosic polysaccharides of softwood biomass into simple molecules like manno-oligosaccharides and mannose. In this study, we have implemented a strategy of molecular engineering in the yeast Yarrowia lipolytica to improve the specific activity of two fungal endo-mannanases, PaMan5A and PaMan26A, which belong to the glycoside hydrolase (GH families GH5 and GH26, respectively. Following random mutagenesis and two steps of high-throughput enzymatic screening, we identified several PaMan5A and PaMan26A mutants that displayed improved kinetic constants for the hydrolysis of galactomannan. Examination of the three-dimensional structures of PaMan5A and PaMan26A revealed which of the mutated residues are potentially important for enzyme function. Among them, the PaMan5A-G311S single mutant, which displayed an impressive 8.2-fold increase in kcat /KM due to a significant decrease of KM, is located within the core of the enzyme. The PaMan5A-K139R/Y223H double mutant revealed modification of hydrolysis products probably in relation to an amino-acid substitution located nearby one of the positive subsites. The PaMan26A-P140L/D416G double mutant yielded a 30% increase in kcat /KM compared to the parental enzyme. It displayed a mutation in the linker region (P140L that may confer more flexibility to the linker and another mutation (D416G located at the entrance of the catalytic cleft that may promote the entrance of the substrate into the active site. Taken together, these results show that the directed evolution strategy implemented in this study was very pertinent since a straightforward round of random mutagenesis yielded significantly improved variants, in terms of catalytic efiiciency (kcat/KM.

  2. Crystallization of MgFe2O4 from a glass in the system K2O/B2O3/MgO/P2O5/Fe2O3

    El Shabrawy, Samha; Bocker, Christian; Rüssel, Christian


    Spherical magnetic Mg-Fe-O nanoparticles were successfully prepared by the crystallization of glass in the system K2O/B2O3/MgO/P2O5/Fe2O3. The magnetic glass ceramics were prepared by melting the raw materials using the conventional melt quenching technique followed by a thermal treatment at temperatures in the range 560-700 °C for a time ranging from 2 to 8 h. The studies of the X-ray diffraction, electron microscopy and FTIR spectra confirmed the precipitation of finely dispersed spherical (Mg, Fe) based spinel nanoparticles with a minor quantity of hematite (α-Fe2O3) in the glass matrix. The average size of the magnetic nano crystals increases slightly with temperature and time from 9 to 15 nm as determined by the line broadening from the XRD patterns. XRD studies show that annealing the glass samples for long periods of time at temperature ≥604 °C results in an increase of the precipitated hematite concentration, dissolution of the spinel phase and the formation of magnesium di-borate phase (Mg2B2O5). For electron microscopy, the particles were extracted by two methods; (i) replica extraction technique and (ii) dissolution of the glass matrix by diluted acetic acid. An agglomeration of the nano crystals to larger particles (25-35 nm) was observed.

  3. Synthesis, Structure, and Ethanol Gas Sensing Properties of In2O3 Nanorods Decorated with Bi2O3 Nanoparticles.

    Park, Sunghoon; Kim, Soohyun; Sun, Gun-Joo; Lee, Chongmu


    Bi2O3-decorated In2O3 nanorods were synthesized using a one-step process, and their structure, as well as the effects of decoration of In2O3 nanorods with Bi2O3 on the ethanol gas-sensing properties were examined. The multiple networked Bi2O3-decorated In2O3 nanorod sensor showed responses of 171-1774% at ethanol concentrations of 10-200 ppm at 200 °C. The responses of the Bi2O3-decorated In2O3 nanorod sensor were stronger than those of the pristine-In2O3 nanorod sensors by 1.5-4.9 times at the corresponding concentrations. The two sensors exhibited short response times and long recovery times. The optimal Bi concentration in the Bi2O3-decorated In2O3 nanorod sensor and the optimal operation temperature of the sensor were 20% and 200 °C, respectively. The Bi2O3-decorated In2O3 nanorod sensor showed selectivity for ethanol gas over other gases. The origin of the enhanced response, sensing speed, and selectivity for ethanol gas of the Bi2O3-decorated In2O3 nanorod sensor to ethanol gas is discussed.

  4. Phase equilibria in the P(2)O(5)-CaO-CaF(2)-NaF-H(2)O quinary system and the formation of apatite

    Martin, Roger Isaac

    Phase equilibria among calcium phosphates in the Hsb3POsb4-Ca(OH)sb2-Hsb2O ternary system were determined as a basis for research in the formation of hydroxyapatite, a biomaterial. The acidic portion of the ternary diagram was established. Ca(Hsb2POsb4)sb2 was not stable for temperatures below 100sp°C. The experimental and theoretical dissolution paths of Ca(Hsb2POsb4)sb2{*}Hsb2O were compared. It is possible for the initial dissolution of Ca(Hsb2POsb4)sb2{*}Hsb2O to supersaturate the system with respect to hydroxyapatite because Ca(Hsb2POsb4)sb2{*}Hsb2O is "twice" incongruently soluble. Hydroxyapatite composition is variable with a Ca/P ratio ranging from 1.5 to 1.67. Hydroxyapatite formation from acid-base reactions of CaHPOsb4 and Casb4(POsb4)sb2O was investigated for composition at the terminal limits. The total heats-of-reaction (Delta Hsb{r}) were determined to be 261.3 and 320 kJ/mol for the formation of calcium deficient and stoichiometric hydroxyapatite, respectively. Activation energies of 84.7 and 87.4 kJ/mol were calculated for the formation of calcium deficient and stoichiometric hydroxyapatite, respectively. Heats-of-formation (Delta Hsb{f}) for Casb4(POsb4)sb2O and Casb9HPOsb4(POsb4)sb5OH were calculated to be -4764.1 and -1207.7 kJ/mol, respectively. The effects of magnesium on hydroxyapatite formation in vitro from CaHPOsb4 and Casb4(POsb4)sb2O at 37.4sp°C were investigated. Magnesium is a biological agent with 0.78 mM concentrations in blood. Magnesium inhibited nucleation for 1 mM concentrations and above for a 5 liquid-to-solids ratio. However, a 5 mM concentration of MgClsb2 slightly accelerated the growth rate. The activity of magnesium is approximately 6% of its concentration. Therefore the inorganic chemical activity of magnesium may not significantly inhibit the formation of bioapatites. Phase equilibria in the Psb2Osb5-CaO-CaFsb2-Hsb2O system at 37.4sp°C was determined and dental fluorosis explained. Fluoroapatite dissolves

  5. The H2O2-H2O Hypothesis: Extremophiles Adapted to Conditions on Mars?

    Houtkooper, Joop M.; Schulze-Makuch, Dirk


    The discovery of extremophiles on Earth is a sequence of discoveries of life in environments where it had been deemed impossible a few decades ago. The next frontier may be the Martian surface environment: could life have adapted to this harsh environment? What we learned from terrestrial extremophiles is that life adapts to every available niche where energy, liquid water and organic materials are available so that in principle metabolism and propagation are possible. A feasible adaptation mechanism to the Martian surface environment would be the incorporation of a high concentration of hydrogen peroxide in the intracellular fluid of organisms. The H2O2-H2O hypothesis suggests the existence of Martian organisms that have a mixture of H2O2 and H2O instead of salty water as their intracellular liquid (Houtkooper and Schulze-Makuch, 2007). The advantages are that the freezing point is low (the eutectic freezes at 56.5°C) and that the mixture is hygroscopic. This would enable the organisms to scavenge water from the atmosphere or from the adsorbed layers of water molecules on mineral grains, with H2O2 being also a source of oxygen. Moreover, below its freezing point the H2O2-H2O mixture has the tendency to supercool. Hydrogen peroxide is not unknown to biochemistry on Earth. There are organisms for which H2O2 plays a significant role: the bombardier beetle, Brachinus crepitans, produces a 25% H2O2 solution and, when attacked by a predator, mixes it with a fluid containing hydroquinone and a catalyst, which produces an audible steam explosion and noxious fumes. Another example is Acetobacter peroxidans, which uses H2O2 in its metabolism. H2O2 plays various other roles, such as the mediation of physiological responses such as cell proliferation, differentiation, and migration. Moreover, most eukaryotic cells contain an organelle, the peroxisome, which mediates the reactions involving H2O2. Therefore it is feasible that in the course of evolution, water-based organisms

  6. Bi-modal improvement of the physico-chemical characteristics of PEG and MFe{sub 2}O{sub 4} subnanoferrite

    Ahmed, M.A., E-mail: [Materials Science Lab (1), Physics Department, Faculty of Science, Cairo University, Giza (Egypt); Okasha, N. [Physics Department, Faculty of Girls, Ain Shams University, Cairo (Egypt); Mansour, S.F. [Physics Department, Faculty of Science, Zagazig University, Zagazig (Egypt); El-dek, S.I. [Materials Science Lab (1), Physics Department, Faculty of Science, Cairo University, Giza (Egypt)


    MFe{sub 2}O{sub 4} (M = Mn{sup 2+}, Ni{sup 2+}, Co{sup 2+} and Cu{sup 2+}) ferrite powders were prepared by flash auto-combustion reaction. The structural identification of the samples was carried out using X-ray diffraction (XRD), transmission electron microscope (TEM), selected area electron diffraction (SAED) and IR spectra. The study established the formation of sub-nanosized particles especially for MFe{sub 2}O{sub 4} (M = Ni, Co and Cu) ferrites. MFe{sub 2}O{sub 4}/PEG (polyethylene glycol) composites were prepared by cold uniaxial pressing. The magnetic properties were studied by carrying out the hysteresis of MFe{sub 2}O{sub 4} and PEG/MFe{sub 2}O{sub 4} composite at room temperature. The data showed that MnFe{sub 2}O{sub 4} has the highest saturation magnetization while CoFe{sub 2}O{sub 4} has the largest coercive field due to the high anisotropy of Co{sup 2+} ions. The ac electrical conductivity as well as the dielectric constant {epsilon}{sup '} and loss tangent tan {delta} were measured at different frequencies at room temperature. The highest conductivity is achieved for PEG/Ni Fe{sub 2}O{sub 4} and the lowest value of tan {delta} is obtained for PEG/MnFe{sub 2}O{sub 4} amongst all PEG/MFe{sub 2}O{sub 4} nanocomposites.

  7. Cello-oligosaccharide oxidation reveals differences between two lytic polysaccharide monooxygenases (family GH61) from Podospora anserina.

    Bey, Mathieu; Zhou, Simeng; Poidevin, Laetitia; Henrissat, Bernard; Coutinho, Pedro M; Berrin, Jean-Guy; Sigoillot, Jean-Claude


    The genome of the coprophilic ascomycete Podospora anserina encodes 33 different genes encoding copper-dependent lytic polysaccharide monooxygenases (LPMOs) from glycoside hydrolase family 61 (GH61). In this study, two of these enzymes (P. anserina GH61A [PaGH61A] and PaGH61B), which both harbored a family 1 carbohydrate binding module, were successfully produced in Pichia pastoris. Synergistic cooperation between PaGH61A or PaGH61B with the cellobiose dehydrogenase (CDH) of Pycnoporus cinnabarinus on cellulose resulted in the formation of oxidized and nonoxidized cello-oligosaccharides. A striking difference between PaGH61A and PaGH61B was observed through the identification of the products, among which were doubly and triply oxidized cellodextrins, which were released only by the combination of PaGH61B with CDH. The mass spectrometry fragmentation patterns of these oxidized products could be consistent with oxidation at the C-6 position with a geminal diol group. The different properties of PaGH61A and PaGH61B and their effect on the interaction with CDH are discussed in regard to the proposed in vivo function of the CDH/GH61 enzyme system in oxidative cellulose hydrolysis.

  8. Modification of pGH cDNA using the first intron and adenovirus-mediated expression in CHO cells

    李秀锦; 仲飞; 齐顺章


    Objective This study was conducted to investigate the function of the first intron of porcine growth hormone (pGH) gene in the gene expression.Methods PCR method was used to amplify the first intron from pig genomic DNA. The intron was then inserted into pGH cDNA to construct pGH cDNA-intron (pGH cDNA-in). The recombinant adenoviruses containing pGH cDNA and pGH cDNA-in genes under control of CMV promoter were generated by homologous recombination method in HEK 293 cells respectively. The effect of the first intron on gene expression was evaluated by comparing the expression levels of pGH cDNA-in and pGH cDNA mediated by adenovirus vectors in CHO cells.Results The expression level of pGH cDNA containing the first intron increased by 117%, which was significantly higher than that of pGH cDNA without the intron (P<0.001). Conclusion The first intron of pGH gene has the function to improve pGH gene expression.

  9. $\\Delta$-N Electromagnetic Transition

    Loan, M


    The EM ratio for a free Delta electromagnetic transition is discussed within the frame work of nonrelativistic approach. Such an approach gives a good account of data for a free Delta but is less important for an intrinsically relativistic nuclear many body problem.

  10. Mida pakub Delta? / Teele Kurm

    Kurm, Teele


    Politsei- ja Piirivalveamet võtab kasutusele ühise Siseministeeriumi infotehnoloogia- ja arenduskeskuse ning Webmedia AS koostööna loodud dokumendihaldussüsteemi Delta. Kust sai Delta oma nime? Projekti "Dokumendihaldussüsteemi juurutamine Siseministeeriumi haldusalas" eesmärgid

  11. Delta Electroproduction in 12-C

    Steven McLauchlan


    The Delta-nucleus potential is a crucial element in the understanding of the nuclear system. Previous electroexcitation measurements in the delta region reported a Q2 dependence of the delta mass indicating that this potential is dependent on the momentum of the delta. Such a dependence is not observed for protons and neutrons in the nuclear medium. This thesis presents the experimental study of the electroexcitation of the delta resonance in 12C, performed using the high energy electron beam at the Thomas Jefferson National Accelerator Facility, and the near 4(pie) acceptance detector CLAS that enables the detection of the full reaction final state. Inclusive, semi inclusive, and exclusive cross sections were measured with an incident electron beam energy of 1.162GeV over the Q2 range 0.175-0.475 (GeV/c)2. A Q2 dependence of the delta mass was only observed in the exclusive measurements indicating that the delta-nucleus potential is affected by the momentum of the delta.

  12. Mida pakub Delta? / Teele Kurm

    Kurm, Teele


    Politsei- ja Piirivalveamet võtab kasutusele ühise Siseministeeriumi infotehnoloogia- ja arenduskeskuse ning Webmedia AS koostööna loodud dokumendihaldussüsteemi Delta. Kust sai Delta oma nime? Projekti "Dokumendihaldussüsteemi juurutamine Siseministeeriumi haldusalas" eesmärgid

  13. The glucose-dependent insulinotropic polypeptide receptor is overexpressed amongst GNAS1 mutation-negative somatotropinomas and drives growth hormone (GH)-promoter activity in GH3 cells.

    Occhi, G; Losa, M; Albiger, N; Trivellin, G; Regazzo, D; Scanarini, M; Monteserin-Garcia, J L; Fröhlich, B; Ferasin, S; Terreni, M R; Fassina, A; Vitiello, L; Stalla, G; Mantero, F; Scaroni, C


    Somatic mutations in the GNAS1 gene, encoding the α-subunit of the heterotrimeric stimulatory G protein (Gαs), occur in approximately 40% of growth hormone (GH)-secreting pituitary tumours. By altering the adenylate cyclase-cAMP-protein kinase A pathway, they unequivocally give somatotroph cells a growth advantage. Hence, the pathogenesis of somatotropinomas could be linked to anomalies in receptors coupled to the cAMP second-messenger cascade. Among them, the glucose-dependent insulinotropic polypeptide receptor (GIPR) is already known to play a primary role in the impaired cAMP-dependent cortisol secretion in patients affected by food-dependent Cushing's syndrome. In the present study, 43 somatotropinomas and 12 normal pituitary glands were investigated for GIPR expression by quantitative reverse transcriptase-polymerase chain reaction, western blotting and immunohistochemistry. Tumoural specimens were also evaluated for GNAS1 mutational status. The effect of GIPR overexpression on cAMP levels and GH transcription was evaluated in an in vitro model of somatotropinomas, the GH-secreting pituitary cell line GH3. GIPR was expressed at higher levels compared to normal pituitaries in 13 GNAS1 mutation-negative somatotropinomas. GIP stimulated adenylyl cyclase and GH-promoter activity in GIPR-transfected GH3 cells, confirming a correct coupling of GIPR to Gαs. In a proportion of acromegalic patients, GIPR overexpression appeared to be associated with a paradoxical increase in GH after an oral glucose tolerance test. Whether GIPR overexpression in acromegalic patients may be associated with this paradoxical response or more generally involved in the pathogenesis of acromegaly, as suggested by the mutually exclusive high GIPR levels and GNAS1 mutations, remains an open question.

  14. The Effect of a Six- Month Aerobic Exercise on Levels of GH, IGF-1 and GH/IGF-1 Ratio Serum in Sedentary Middle-aged Women

    N Bijeh


    Full Text Available Introduction: In recent years, a number of researches have been carried out regarding the relationship between atherosclerosis and serum levels of GH and IGF-1 and different results were obtained. This study aimed to determine the effect of a six-month aerobic exercise on levels of GH, IGF-1 and GH/IGF-1 ratio serum in sedentary middle-aged women Methods: Nineteen healthy females, who were selected by convenience sampling method, were divided into two [active (n=11 and non-active (n=8] groups. The exercise protocol included aerobic exercise training lasted for 6 months and 3 sessions per week. Every session lasted for 60 minutes with intensity of 55-65 percent of heart rate reserve. Blood samples were taken and Serum IGF-1 and GH were measured before and after six months of aerobic training. To make intra and intergroup comparisons as well as to investigate the interactive effect, repeated measure analysis of variance were used. For all statistical comparisons, the level of significance was set at p < 0.05. Results: This study demonstrated that the level of serum IGF-1 in middle-aged women decreased significantly (P=0.016. However, the levels of GH didn't change significantly during this period. Moreover, GH to IGF-1 ratio increased significantly (P=0.007. Conclusion: The study results indicated that six-month aerobic exercise led to a decrease on the levels of IGF-1 and did not make a change in GH serum in sedentary middle-aged women. In other words, doing aerobic exercises reduced IGF-1 levels that have a significant relationship with severity of a coronary disease and thus can prevent the atherosclerosis disease.

  15. Mackenzie River Delta, Canada


    The Mackenzie River in the Northwest Territories, Canada, with its headstreams the Peace and Finley, is the longest river in North America at 4241 km, and drains an area of 1,805,000 square km. The large marshy delta provides habitat for migrating Snow Geese, Tundra Swans, Brant, and other waterfowl. The estuary is a calving area for Beluga whales. The Mackenzie (previously the Disappointment River) was named after Alexander Mackenzie who travelled the river while trying to reach the Pacific in 1789. The image was acquired on August 4, 2005, covers an area of 55.8 x 55.8 km, and is located at 68.6 degrees north latitude, 134.7 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.


    ȘOVĂILĂ Florin


    Full Text Available 3D printing is a very used process in industry, the generic name being “rapid prototyping”. The essential advantage of a 3D printer is that it allows the designers to produce a prototype in a very short time, which is tested and quickly remodeled, considerably reducing the required time to get from the prototype phase to the final product. At the same time, through this technique we can achieve components with very precise forms, complex pieces that, through classical methods, could have been accomplished only in a large amount of time. In this paper, there are presented the stages of a 3D model execution, also the physical achievement after of a Delta 3D printer after the model.

  17. Thorium divanadate dihydrate, Th(V2O7(H2O2

    Mohamed Saadi


    Full Text Available The title compound, Th(V2O7(H2O2, was synthesized by a hydrothermal reaction. The crystal structure consists of ThO7(OH22 tricapped trigonal prisms that share edges, forming [ThO5(OH22]n chains along [010]. The edge-sharing ThO7(OH22 polyhedra share one edge and five vertices with the V2O7 divanadate anions having a nearly ecliptic conformation parallel to [001]. This results in an open framework with the water molecules located in channels. O—H...O hydrogen bonding between water molecules and framework O atoms is observed. Bond-valence-sum calculations are in good agreement with the chemical formula of the title compound.

  18. Adsorption and dissociation of H2O on Cu2O(100):A computational study

    Yun Li; Lifen Yan; Guichang Wang


    The adsorption and dissociation of water on Cu2O(100)have been investigated by the density functional theory-generalized gradient approximation(DFT GGA)method.The corresponding reaction energies,the structures of the transition states and the activation energies were determined.Calculations with and without dipole correction were both studied to get an understanding of the effect of the dipole moment on the adsorption and reaction of water on dipole surface Cu2O(100).When dipole correction was added,the adsorption energies of H2O on different sites generally decreased.The calculated activation barriers for HxO(x=1,2)dehydrogenation are 0.42 eV(1.01 eV without the dipole correction)and 1.86 eV,respectively,including the zero point energy correction.The first dehydrogenation outcome is energetically the most stable product.

  19. Synthesis and Thermodynamic Properties of MgO·B2O3·4H2O

    LIU,Zhi-Hong(刘志宏); GAO,Shi-Yang(高世扬); HU,Man-Cheng(胡满成); XIA,Shu-Ping(夏树屏)


    A new magnesium borate MgO@ B2O3 @ 4H2O was synthesized by the method of phase transformation of double salt and characterized by XRD, IR spectra and TG. The structural formula of this compound was Mg[B2O(OH)6] @H2O. The enthalpy of solution of MgO@B2O3@4H2O in HCl (1.0492 mol@ L-1) was determined. With the incorporation of the standard molar enthalpies of formation of MgO (s), H3BO3(s), and H2O (Ⅰ),the standard molar enthalpy of formation of - (3135.31 ±1.68) kJ@ mol-1 of MgO@B2O3@4H2O was obtained. Thermodynamic properties of this compoumd were also calculated by group contribution method.

  20. Redetermination of metarossite, CaV5+2O6·2H2O

    Anaïs Kobsch


    Full Text Available The crystal structure of metarossite, ideally CaV2O6·2H2O [chemical name: calcium divanadium(V hexaoxide dihydrate], was first determined using precession photographs, with fixed isotropic displacement parameters and without locating the positions of the H atoms, leading to a reliability factor R = 0.11 [Kelsey & Barnes (1960. Can. Mineral. 6, 448–466]. This communication reports a structure redetermination of this mineral on the basis of single-crystal X-ray diffraction data of a natural sample from the Blue Cap mine, San Juan County, Utah, USA (R1 = 0.036. Our study not only confirms the structural topology reported in the previous study, but also makes possible the refinement of all non-H atoms with anisotropic displacement parameters and all H atoms located. The metarossite structure is characterized by chains of edge-sharing [CaO8] polyhedra parallel to [100] that are themselves connected by chains of alternating [VO5] trigonal bipyramids parallel to [010]. The two H2O molecules are bonded to Ca. Analysis of the displacement parameters show that the [VO5] chains librate around [010]. In addition, we measured the Raman spectrum of metarossite and compared it with IR and Raman data previously reported. Moreover, heating of metarossite led to a loss of water, which results in a transformation to the brannerite-type structure, CaV2O6, implying a possible dehydration pathway for the compounds M2+V2O6·xH2O, with M = Cu, Cd, Mg or Mn, and x = 2 or 4.

  1. Specific expression of a β-tubulin gene (GhTub1) in developing cotton fibers

    LI; Yuanli; (李园莉); SUN; Jie; (孙杰); LI; Chunhong; (李春红); ZHU; Yongqing; (朱勇清); XIA; Guixian; (夏桂先)


    A cDNA library was constructed using poly (A)+ RNA isolated from -1-15 DPA fibers of upland cotton (Gossypium hirsutum). The cDNA encoding a β-tubulin isoform (designated as GhTub1) was identified through EST search. Northern blot analysis using 3′-UTR of the cDNA as a gene-specific probe was performed to investigate the expression levels of GhTub1 in various organs and in the developing fibers. The results showed that GhTub1 gene was specifically expressed in cotton fiber cells. During fiber development, GhTub1 transcripts accumulated highlyat the stage of cell rapid elongation with the highest expression appearing at the time when fiber expansion reaches the peak rate. To probe the in vivo function of GhTub1, its cDNA was cloned in the yeast expression vector pREP1 and transformed into the fission yeast Schizosaccharomyces pombe. Overexpression of GhTub1 in yeast cells caused severe changes in the cell morphology. These results suggest that GhTub1 may play a role in the polar elongation of cotton fibers. To our knowledge, this is the first report on the fiber-specific transcript accumulation of a cotton β-tubulin gene.


    Z.Li; G.Q.Zhang; Z.H.Zhang; S.F.Tian


    In order to evaluate the deformation characteristics of spray formed superalloy GH742 and determine the appropriate forging procedure of the alloy on this basis,the influence of deformation temperature and strain rate on the ductility of spray formed GH742 was investigated by using the Gleeble-3500 thermal-mechanical testing machine.It is shown that the forgeability of spray formed GH742 is better than conventional GH742 by ingot metallurgy because of refined grain structure and enhanced chemical homogeneity of spray formed GH742.In the temperature range of 1020 to 1100℃,the ductility of spray formed GH742 is dependent on the deformation temperature and is increased linearly in proportion to the increment of deformation temperature,which is more than 40% at 1020℃ and more than 60% at the temperature between 1100 and 1140℃.Furthermore,the results indicate the flow stress is affected considerably by the deformation temperature and strain rate.In the temperature range of 1020 to 1140℃,the maximum flow stress of spray formed GH742 increases with the increment of strain rate and decreases with the increment of the deformation temperature.

  3. Papel emergente do eixo GH/IGF-I no controle cardiometabólico

    Carla R.P Oliveira


    Full Text Available O hormônio de crescimento (GH, principal regulador do crescimento pós-natal, tem importantes ações metabólicas em diferentes tecidos, sinérgicas ou até antagônicas às do fator de crescimento semelhante à insulina tipo I (IGF-I, produzido sobretudo no fígado após ligação do GH ao seu receptor. Experimentos em modelos animais indicam um papel importante do GH na resistência a insulina, enquanto o papel do IGF-I nessa condição ainda não está completamente elucidado. Em humanos, o GH promove aumento da lipólise e da oxidação lipídica, enquanto o IGF-I desencadeia o aumento da oxidação lipídica apenas cronicamente. Enquanto as ações sobre o crescimento são tempo limitado, as ações metabólicas e cardiovasculares do eixo GH/IGF-I perduram durante toda a vida. Os potenciais efeitos anabólicos do GH têm sido utilizados em condições crônicas e hipercatabólicas, embora as investigações sobre os desfechos clínicos ainda sejam escassas. Neste artigo, pretendemos revisar as ações metabólicas do GH oriundas de modelos animais, os estudos em humanos normais e indivíduos com deficiência de GH, diabete melito tipo 1, síndrome metabólica, estados hipercatabólicos e a relação do eixo GH/IGF-I com as adipocinas, disfunção endotelial e aterogênese

  4. Does the GH/IGF-1 axis contribute to skeletal sexual dimorphism? Evidence from mouse studies.

    Liu, Zhongbo; Mohan, Subburaman; Yakar, Shoshana


    The contribution of the gonadotropic axis to skeletal sexual dimorphism (SSD) was clarified in recent years. Studies with animal models of estrogen receptor (ER) or androgen receptor (AR) null mice, as well as mice with bone cell-specific ablation of ER or AR, revealed that both hormones play major roles in skeletal acquisition, and that estrogen regulates skeletal accrual in both sexes. The growth hormone (GH) and its downstream effector, the insulin-like growth factor-1 (IGF-1) are also major determinants of peak bone mass during puberty and young adulthood, and play important roles in maintaining bone integrity during aging. A few studies in both humans and animal models suggest that in addition to the differences in sex steroid actions on bone, sex-specific effects of GH and IGF-1 play essential roles in SSD. However, the contributions of the somatotropic (GH/IGF-1) axis to SSD are controversial and data is difficult to interpret. GH/IGF-1 are pleotropic hormones that act in an endocrine and autocrine/paracrine fashion on multiple tissues, affecting body composition as well as metabolism. Thus, understanding the contribution of the somatotropic axis to SSD requires the use of mouse models that will differentiate between these two modes of action. Elucidation of the relative contribution of GH/IGF-1 axis to SSD is significant because GH is approved for the treatment of normal children with short stature and children with congenital growth disorders. Thus, if the GH/IGF-1 axis determines SSD, treatment with GH may be tailored according to sex. In the following review, we give an overview of the roles of sex steroids in determining SSD and how they may interact with the GH/IGF-1 axis in bone. We summarize several mouse models with impaired somatotropic axis and speculate on the possible contribution of that axis to SSD.

  5. Pharmacogenomics of insulin-like growth factor-I generation during GH treatment in children with GH deficiency or Turner syndrome

    Stevens, A; Clayton, P; Tatò, L; Yoo, H W; Rodriguez-Arnao, M D; Skorodok, J; Ambler, G R; Zignani, M; Zieschang, J; Della Corte, G; Destenaves, B; Champigneulle, A; Raelson, J; Chatelain, P


    Individual responses to growth hormone (GH) treatment are variable. Short-term generation of insulin-like growth factor-I (IGF-I) is recognized as a potential marker of sensitivity to GH treatment. This prospective, phase IV study used an integrated genomic analysis to identify markers associated with 1-month change in IGF-I (ΔIGF-I) following initiation of recombinant human (r-h)GH therapy in treatment-naïve children with GH deficiency (GHD) (n=166) or Turner syndrome (TS) (n=147). In both GHD and TS, polymorphisms in the cell-cycle regulator CDK4 were associated with 1-month ΔIGF-I (P<0.05). Baseline gene expression was also correlated with 1-month ΔIGF-I in both GHD and TS (r=0.3; P<0.01). In patients with low IGF-I responses, carriage of specific CDK4 alleles was associated with MAPK and glucocorticoid receptor signaling in GHD, and with p53 and Wnt signaling pathways in TS. Understanding the relationship between genomic markers and early changes in IGF-I may allow development of strategies to rapidly individualize r-hGH dose. PMID:23567489

  6. Targeted deletion of growth hormone (GH) receptor in macrophage reveals novel osteopontin-mediated effects of GH on glucose homeostasis and insulin sensitivity in diet-induced obesity.

    Lu, Chunxia; Kumar, P Anil; Sun, Jinhong; Aggarwal, Anjali; Fan, Yong; Sperling, Mark A; Lumeng, Carey N; Menon, Ram K


    We investigated GH action on macrophage (MΦ) by creating a MΦ-specific GH receptor-null mouse model (MacGHR KO). On a normal diet (10% fat), MacGHR KO and littermate controls exhibited similar growth profiles and glucose excursions on intraperitoneal glucose (ipGTT) and insulin tolerance (ITT) tests. However, when challenged with high fat diet (HFD, 45% fat) for 18 weeks, MacGHR KO mice exhibited impaired ipGTT and ITT compared with controls. In MacGHR KO, adipose-tissue (AT) MΦ abundance was increased with skewing toward M1 polarization. Expression of pro-inflammatory cytokines (IL1β, TNF-α, IL6, and osteopontin (OPN)) were increased in MacGHR KO AT stromal vascular fraction (SVF). In MacGHR KO AT, crown-like-structures were increased with decreased insulin-dependent Akt phosphorylation. The abundance of phosphorylated NF-κB and of OPN was increased in SVF and bone-marrow-derived MΦ in MacGHR KO. GH, acting via an NF-κB site in the distal OPN promoter, inhibited the OPN promoter. Thus in diet-induced obesity (DIO), lack of GH action on the MΦ exerts an unexpected deleterious effect on glucose homeostasis by accentuating AT inflammation and NF-κB-dependent activation of OPN expression. These novel results in mice support the possibility that administration of GH could have salutary effects on DIO-associated chronic inflammation and insulin resistance in humans.

  7. Intra-individual variation of GH-dependent markers in athletes: comparison of population based and individual thresholds for detection of GH abuse in sports.

    Kniess, Astrid; Ziegler, Eckart; Thieme, Detlef; Müller, R Klaus


    The GH-2000 discriminant functions, using insulin-like growth factor I (IGF-I) and the N-terminal propeptide of type III procollagen (PIIINP), enabled the detection of growth hormone (GH) doping despite the broad inter-individual normal range of both peptides. The sensitivity of the discriminant function-based methodology may perhaps be further increased in future by applying individual athlete profiles. The purpose of the present study was to evaluate the intra-individual variability of IGF-I, PIIINP and the GH-2000 scores in athletes. For this purpose a total of eight blood samples were taken from each of fifty male and female elite athletes over a period of up to 18 months. The IGF-I and PIIINP levels, we found, lay predominantly within the reference range for elite athletes. The intra-individual variability for IGF-I ranged between 6 and 26%, while that for PIIINP ranged between 6 and 33%. The intra-individual variations of both parameters were higher in female than in male subjects and were found to be mostly moderate. We found that the intra-individual variations of the GH-2000 test scores, expressed as CV, ranged from 4 to 36% and were in most of the subjects markedly smaller than the inter-individual variation. Individual cut-offs for the GH-2000 scores would be lower than population based ones in most of the cases.

  8. Serum leptin levels and leptin expression in growth hormone (GH)-deficient and healthy adults: influence of GH treatment, gender, and fasting.

    Kristensen, K; Pedersen, S B; Fisker, S; Nørrelund, H; Rosenfalck, A M; Jørgensen, J O; Richelsen, B


    Growth hormone (GH) treatment is associated with a reduction in fat mass in healthy and GH-deficient (GHD) subjects. This is mainly mediated via a direct GH action on adipose cells and stimulation of lipolysis. Leptin is secreted from adipose tissue and may be involved in signaling information about adipose tissue stores to the brain. Hormonal regulation of leptin is still not fully elucidated, and in the present study, we investigated both the long-term (4-month) and short-term (28-hour) GH effects on serum leptin and leptin gene expression in subcutaneous adipose tissue. In GHD adults (n = 24), leptin correlated with most estimates of adiposity (r = .62 to .86), as previously found in healthy subjects. However, no correlation was observed with intraabdominal fat determined by computed tomographic (CT) scan (INTRA-CT). GH treatment for 4 months had no independent effect on either serum leptin or leptin gene expression. In a short-term study, we found that fasting gradually reduced leptin levels in both healthy men and GHD adults, with a maximum reduction of 58% to 60% (P fasting. Adipose tissue leptin mRNA correlated with serum leptin (r = .51, P hormones) may be causal factors for the gender difference in leptin.

  9. GH/IGF-I axis and matrix adaptation of the musculotendinous tissue to exercise in humans

    Heinemeier, K M; Mackey, Abigail; Doessing, S


    Exercise is not only associated with adaptive responses within skeletal muscle fibers but also with induction of collagen synthesis both in muscle and adjacent connective tissue. Additionally, exercise and training leads to activation of the systemic growth hormone/insulin-like growth factor I axis...... (GH/IGF-I), as well as increased local IGF-I expression. Studies in humans with pathologically high levels of GH/IGF-I, and in healthy humans who receive either weeks of GH administration or acute injection of IGF-I into connective tissue, demonstrate increased expression and synthesis of collagen...


    Fitriyah Husnul Khotimah


    Full Text Available Masalah yang paling utama dalam budidaya abalon tropis adalah pertumbuhan yang lambat. Penggunaan rElGH (recombinant giant grouper, Epinephelus lanceolatus growth hormone untuk menstimulasi pertumbuhan beberapa spesies ikan sudah dilakukan. Penelitian ini bertujuan untuk menguji akselerasi pertumbuhan juvenil abalon tropis, Haliotis squamata setelah diberi perlakuan perendaman hormon rekombinan ikan kerapu kertang, Epinephelus lanceolatus pada frekuensi yang berbeda. Ada empat perlakuan frekuensi perendaman rElGH yaitu 4, 9, 16 kali, dan tanpa perendaman (kontrol. Masing-masing perlakuan diulang tiga kali. Perendaman dilakukan selama tiga jam, dengan interval waktu empat hari. Kepadatan abalon tropis 100 ekor/L air laut yang mengandung 30 mg rElGH. Wadah untuk perendaman berupa beaker glass yang dilengkapi dengan aerasi. Penelitian dilakukan selama tujuh bulan. Hasil penelitian menunjukkan bahwa abalon tropis yang direndam rElGH dengan frekuensi empat kali menghasilkan pertumbuhan bobot tubuh dan panjang cangkang tertinggi dan berbeda nyata dengan perlakuan lainnya (P<0,05. Sintasan abalon tropis yang diberi perlakuan perendaman hormon rElGH lebih tinggi dibandingkan perlakuan kontrol. The most crucial problem in tropical abalone aquaculture is the slow growth of the species. Studies investigating the use of rElGH (recombinant giant grouper, Epinephelus lanceolatus growth hormone for promoting growth have been performed in various species. This research aimed to examine the growth acceleration of tropical abalone, Haliotis squamata juvenile after being treated in different immersion frequencies of recombinant giant grouper, Epinephelus lanceolatus growth hormone (rElGH. There were four treatments of rElGH immersion frequency: 4, 9, 16 times and without rElGH immersion (control. Each treatment was performed in triplicates. Immersion was performed for 3 hours, at 4-day intervals and a density of 100 tropical abalones in 1 L seawater containing 30

  11. A novel soluble supramolecular system for sustained rh-GH delivery.

    Salmaso, Stefano; Bersani, Sara; Scomparin, Anna; Balasso, Anna; Brazzale, Chiara; Barattin, Michela; Caliceti, Paolo


    Methoxy-poly(ethylene glycol)s bearing a terminal cholanic moiety (mPEG(5kDa)-cholane, mPEG(10kDa)-cholane and mPEG(20kDa)-cholane) were physically combined with recombinant human growth hormone (rh-GH) to obtain supramolecular assemblies for sustained hormone delivery. The association constants (Ka) calculated by Scatchard analysis of size exclusion chromatography (SEC) data were in the order of 10(5)M(-1). The complete rh-GH association with mPEG(5kDa)-cholane, mPEG(10kDa)-cholane and mPEG(20kDa)-cholane was achieved with 7.5 ± 1.1, 3.9 ± 0.4 and 2.6 ± 0.4 w/w% rh-GH/mPEG-cholane, respectively. Isothermal titration calorimetry (ITC) yielded association constants similar to that calculated by SEC and showed that rh-GH has 21-25 binding sites for mPEG-cholane, regardless the polymer molecular weight. Dialysis studies showed that the mPEG-cholane association strongly delays the protein release; 80-90% of the associated rh-GH was released in 200 h. However, during the first 8h the protein formulations obtained with mPEG(10kDa)-cholane and mPEG(20kDa)-cholane showed a burst release of 8 and 28%, respectively. Circular dichroism (CD) analyses showed that the mPEG(5kDa)-cholane association does not alter the secondary structure of the protein. Furthermore, mPEG(5kDa)-cholane was found to enhance both the enzymatic and physical stability of rh-GH. In vivo pharmacokinetic and pharmacodynamic studies were performed by subcutaneous administration of rh-GH and rh-GH/mPEG(5kDa)-cholane to normal and hypophysectomised rats. The study showed that mPEG(5kDa)-cholane decreases the maximal concentration in the blood but prolongs the body exposure of the protein, which resulted in 55% bioavailability increase. Finally, rh-GH formulated with mPEG(5kDa)-cholane yielded prolonged weight increase of hypophysectomised rats as compared to rh-GH in buffer or formulated with mPEG(5kDa)-OH. After the second administration the weight of the animals treated with rh-GH formulated with m

  12. Association of bGH and Pit-1 gene variants with milk production traits in dairy Gyr bulls.

    Mattos Keiko Kusamura de; Del Lama Silvia Nassif; Martinez Mario Luiz; Freitas Ary Ferreira de


    The objective of this study was to obtain genetic marker information in the Gyr breed by analyzing bGH and Pit-1 gene polymorphisms and to verify their association with milk production traits. One sample including 40 Gyr bulls were genotyped at two bGH gene restriction sites (bGH- AluI and bGH-MspI) and at one restriction site in the Pit-1 gene (Pit-1 HinfI). The bGH-MspI(-) allele was favorable for fat milk percentage. The heterozigous Pit-1 HinfI (+/-) bulls were superior for fat milk produ...

  13. Ca3Mn2O7.

    Guiblin, Nicolas; Grebille, Dominique; Leligny, Henri; Martin, Christine


    The tricalcium dimanganese heptaoxide (Ca3Mn2O7) member of the Ruddlesden-Popper series Ca(n+1)Mn(n)O(3n+1), i.e. with n = 2, was previously reported with an I-centred tetragonal lattice [a(t) = 3.68 and c(t) = 19.57 A] by Fawcett, Sunstrom, Greenblatt, Croft & Ramanujachary [Chem. Mater. (1998), 10, 3643-3651]. It is now found to be orthorhombic, with an A-centred lattice [a = 5.2347 (6), b = 5.2421 (2) and c = 19.4177 (19) A]. The structure has been refined in space group A2(1)am using X-ray single-crystal diffraction data and assuming the existence of twin domains related by the (1-10) plane. A comparison with the basic perovskite structure CaMnO3 (n = infinity) is proposed.

  14. Microcosm N2O emissions wth calibration

    The dataset consists of measurements of soil nitrous oxide emissions from soils under three different amendments: glucose, cellulose, and manure. Data includes the four isotopomers of nitrous oxide (14N15N16O, 15N14N16O, 14N14N18O, 14N14N16O), and the site preference.This dataset is associated with the following publication:Chen , H., D. Williams , P. Deshmukh , F. Birgand, B. Maxwell, and J. Walker. Probing the Biological Sources of Soil N2O Emissions by Quantum Cascade Laser-Based 15N Isotopocule Analysis. SOIL SCIENCE SOCIETY OF AMERICA JOURNAL. Soil Science Society of America, Madison, WI, USA, 100(0): 175-181, (2016).

  15. Drastic Dependence of the pH Sensitivity of Fe2O3-Bi2O3-B2O3 Hydrophobic Glasses with Composition

    Tadanori Hashimoto


    Full Text Available Fe2O3-Bi2O3-B2O3 (FeBiB glasses were developed as novel pH responsive hydrophobic glasses. The influence of the glass composition on the pH sensitivity of FeBiB glasses was investigated. The pH sensitivity drastically decreased with decreasing B2O3 content. A moderate amount of Fe2O3 and a small amount of B2O3 respectively produces bulk electronic conduction and a pH response on glass surfaces. Because the remaining components of the glass can be selected freely, this discovery could prove very useful in developing novel pH glass electrodes that are self-cleaning and resist fouling.

  16. Properties and Structures of Bi2O3-B2O3-TeO2 Glass

    Guoying Zhao; Ying Tian; Huiyan Fan; Junjie Zhang; Lili Hu


    Glass formation range of Bi2O3-B2O3-TeO2 system has been investigated (B2O3 ≤ 40 mol%).Four glasses with compositions xBi2O3-3OB2O3-(7O-x)TeO2 (x =40,50,60 and 70 mol%) have been prepared by using melt quenching technique.The effect of Bi2O3 content on thermal stability,optical properties and structures of these four Bi2O3-B2O3-TeO2 glasses is systematically investigated by inductive coupled plasma emission spectrometer (ICP),differential scanning calorimetry (DSC),Raman spectra and X-ray photoelectron spectroscopy (XPS).It is found that the density,refractive index and optical basicity increase with increasing Bi2O3.The Raman spectra and XPS spectra show that the glass network is mainly constituted by the [BiO6]octahedron,[TeO4] trigonal bipyramidal,[TeO3] trigonal pyramid,[BO3] trigonal pyramid and [BO4] tetrahedron structural units.With increasing Bi2O3,the coordination number around B atom changes from 3 to 4 and [TeO4] units are converted to [TeO3] units.Bi5+ ions may exist in Bi2O3-B2O3-TeO2 (BBT) system and their amount grows with increasing Bi2O3 content.

  17. Redetermination of junitoite, CaZn2Si2O7·H2O

    Hexiong Yang


    Full Text Available The crystal structure of the mineral junitoite, ideally CaZn2Si2O7·H2O (calcium dizinc disilicate monohydrate, was first determined by Hamilton & Finney [Mineral. Mag. (1985, 49, 91–95] based on the space group Ama2, yielding a reliability factor R of 0.10, with isotropic displacement parameters for all non-H atoms. The present study reports a structure redetermination of junitoite using single-crystal X-ray diffraction data from a natural sample, demonstrating that the space group of this mineral is actually Aea2, which can be attained simply by shifting the origin. Topologically, the structure models in the space groups Aea2 and Ama2 are analogous, consisting of chains of corner-sharing ZnO4 tetrahedra parallel to the b axis, cross-linked by Si2O7 tetrahedral dimers (the site symmetry of the bridging O atom is ..2 along a and c, forming a three-dimensional framework. The Ca2+ cations (site symmetry ..2 are situated in cavities of the framework and are bonded to five O atoms and one H2O molecule (site symmetry ..2 in a distorted octahedral coordination environment. However, some bond lengths, especially for the SiO4 tetrahedron, are noticeably different between the two structure models. Hydrogen bonding in junitoite is found between the water molecule and a framework O atom.

  18. Electrochemistry of LiCl-Li2O-H2O Molten Salt Systems

    Natalie J. Gese; Batric Pesic


    Uranium can be recovered from uranium oxide (UO2) spent fuel through the combination of the oxide reduction and electrorefining processes. During oxide reduction, the spent fuel is introduced to molten LiCl-Li2O salt at 650 degrees C and the UO2 is reduced to uranium metal via two routes: (1) electrochemically, and (2) chemically by lithium metal (Li0) that is produced electrochemically. However, the hygroscopic nature of both LiCl and Li2O leads to the formation of LiOH, contributing hydroxyl anions (OH-), the reduction of which interferes with the Li0 generation required for the chemical reduction of UO2. In order for the oxide reduction process to be an effective method for the treatment of uranium oxide fuel, the role of moisture in the LiCl-Li2O system must be understood. The behavior of moisture in the LiCl-Li2O molten salt system was studied using cyclic voltammetry, chronopotentiometry and chronoamperometry, while reduction to hydrogen was confirmed with gas chromatography.

  19. Nanosized As2O3/Fe2O3 complexes combined with magnetic fluid hyperthermia selectively target liver cancer cells

    Zi-Yu Wang; Jian Song; Dong-Sheng Zhang


    AIM: To study the methods of preparing the magnetic nano-microspheres of Fe2O3 and As2O3/Fe2O3 complexes and their therapeutic effects with magnetic fluid hyperthermia (MFH). METHODS: Nanospheres were prepared by chemical co-precipitation and their shape and diameter were observed. Hemolysis, micronucleus, cell viability, and LD50 along with other in vivo tests were performed to evaluate the Fe2O3 microsphere biocompatibility. The inhibition ratio of tumors after Fe2O3 and As2O3/Fe2O3 injections combined with induced hyperthermia in xenograft human hepatocarcinoma was calculated. RESULTS: Fe2O3 and As2O3/Fe2O3 particles were round with an average diameter of 20 nm and 100 nm as observed under transmission electron microscope. Upon exposure to an alternating magnetic field (AMF), the temperature of the suspension of magnetic particles increased to 41-51℃, depending on different particle concentrations, and remained stable thereafter. Nanosized Fe2O3 microspheres are a new kind of biomaterial without cytotoxic effects. The LD50 of both Fe2O3 and As2O3/Fe2O3 in mice was higher than 5 g/kg. One to four weeks after Fe2O3 and As2O3/Fe2O3 complex injections into healthy pig livers, no significant differences were found in serum AST, ALT, BUN and Cr levels among the pigs of all groups (P > 0.05), and no obvious pathological alterations were observed. After exposure to alternating magnetic fields, the inhibition ratio of the tumors was significantly different from controls in the Fe2O3 and As2O3/Fe2O3 groups (68.74% and 82.79%, respectively; P < 0.01). Tumors of mice in treatment groups showed obvious necrosis, while normal tissues adjoining the tumor and internal organs did not.CONCLUSION: Fe2O3 and As2O3/Fe2O3 complexes exerted radiofrequency-induced hyperthermia and drug toxicity on tumors without any liver or kidney damage. Therefore, nanospheres are ideal carriers for tumortargeted therapy.

  20. Meltability diagram of Na/sub 2/O-La/sub 2/O/sub 3/-Nb/sub 2/O/sub 5/ system

    Udalov, Yu.P.; Fedorov, N.F.; Mel' nikova, O.V.; Pivovarova, A.P. (Leningradskij Tekhnologicheskij Inst. (USSR))


    By calculation method using the models of ideal and regular solutions the meltability diagram of the system Na/sub 2/O-La/sub 2/O/sub 3/-Nb/sub 2/O/sub 5/ is built. Fields of primary crystallization of binary compounds and nonvariant points are clarified. Crystallochemical properties of the system phases are presented. A satisfactory agreement of the calculation according to the model of ideal solution with the experimental data is shown.

  1. Photocatalytic Degradation of Methyl Orange on Bi2O3 and Ag2O-Bi2O3 Nano Photocatalysts

    Seyed Ali Hosseini


    Full Text Available The photocatalytic activity of Bi2O3 and Ag2O-Bi2O3 was evaluated by degradation of aqueous methyl orange as a model dye effluent. Bi2O3 was synthesized using chemical precipitation method. Structural analysis revealed that Bi2O3 contain a unique well-crystallized phase and the average crystallite size of 22.4 nm. The SEM analysis showed that the size of Bi2O3 particles was mainly in the range of 16-22 nm. The most important variables affecting the photocatalytic degradation of dyes, namely reaction time, initial pH and catalyst dosage were studied, and their optimal amounts were found at 60 min, 5.58 and 0.025 g, respectively. A good correlation was found between experimental and predicted responses, confirming the reliability of the model. Incorporation of Ag2O in the structure of composite caused decreasing band gap and its response to visible light. Because a high percentage of sunlight is visible light, hence Ag2O-Bi2O3 nano-composite could be used as an efficient visible light driven photocatalyst for degradation of dye effluents by sunlight. Copyright © 2017 BCREC GROUP. All rights reserved Received: 15th August 2016; Revised: 20th December 2016; Accepted: 21st December 2016 How to Cite: Hosseini, S.A., Saeedi, R. (2017. Photocatalytic Degradation of Methyl Orange on Bi2O3 and Ag2O-Bi2O3 Nano Photocatalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (1: 96-105 (doi:10.9767/bcrec.12.1.623.96-105 Permalink/DOI:

  2. Flux pinning effects of Y{sub 2}O{sub 3} nanoparticulate dispersions in multilayered YBCO thin films

    Campbell, T.A. [Air Force Research Laboratory, Propulsion Directorate, AFRL/PRPG, 1950 Fifth Street, Building 450, Wright-Patterson AFB, OH 45433 (United States); Haugan, T.J. [Air Force Research Laboratory, Propulsion Directorate, AFRL/PRPG, 1950 Fifth Street, Building 450, Wright-Patterson AFB, OH 45433 (United States); Maartense, I. [University of Dayton Research Institute, Dayton, OH (United States); Murphy, J. [University of Dayton Research Institute, Dayton, OH (United States); Brunke, L. [University of Dayton Research Institute, Dayton, OH (United States); Barnes, P.N. [Air Force Research Laboratory, Propulsion Directorate, AFRL/PRPG, 1950 Fifth Street, Building 450, Wright-Patterson AFB, OH 45433 (United States)]. E-mail:


    The flux pinning effects of Y{sub 2}O{sub 3} nanoparticulate inclusions in YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (Y123 or YBCO) thin films using (Y{sub 2}O{sub 3}/Y123) x N multilayer structures were studied. The multilayer films were made with pulsed laser deposition (PLD) on SrTiO{sub 3} and LaAlO{sub 3} substrates with a Y{sub 2}O{sub 3} nanoparticulate 'pseudo-layer' thickness ranging from 0.2 to 1.4 nm, and YBCO layer thickness varying from 7 to 50 nm. Scanning electron microscopy images showed well-defined nanoparticle formation on film surfaces, with an approximate number density of (0.8-1.6) x 10{sup 11} particles/cm{sup 2} depending on Y{sub 2}O{sub 3} thickness. Minor reductions in the critical temperature (T {sub c}) were measured for each increase in Y{sub 2}O{sub 3} pseudo-layer thickness. Transport critical currents (77 K, self-field) of 3-5 MA/cm{sup 2} were consistently achieved for composite films with 0.6 nm Y{sub 2}O{sub 3} pseudo-layer thicknesses. Magnetic J {sub c} measurements using vibrating sample magnetometry (H 9 T, at 70 and 77 K) showed a degradation of film properties for Y{sub 2}O{sub 3} pseudo-layer thickness greater than 0.6 nm. A comparison to Y211/Y123 multilayer films showed the thinner Y{sub 2}O{sub 3} pseudo-layer films exhibited similar properties.

  3. Overexpression of GhDof1 improved salt and cold tolerance and seed oil content in Gossypium hirsutum.

    Su, Ying; Liang, Wei; Liu, Zhengjie; Wang, Yumei; Zhao, Yanpeng; Ijaz, Babar; Hua, Jinping


    A homologous GhDof1, which belongs to a large family of plant-specific transcription factor DOF, was isolated from Upland cotton (Gossypium hirsutum L.). GhDof1 protein was located in the nucleus of onion epidermal cells, the core domain of transcriptional activity existed in the C-terminal, and the activity elements of GhDof1 promoter existed in the regions of -645∼ -469bp and -286∼ -132bp of transcriptional start codon. GhDof1 constitutively expressed in leaves, roots and stems, accumulated highest in leaves. The salinity and cold treatments induced GhDof1 transcript accumulation. The GhDof1-overexpressed cotton showed significantly higher salt and cold tolerance over the wild-type plants. Under salt stress, the root growth of overexpressed GhDof1 lines was promoted. The expression levels of stress-responsive genes, GhP5CS, GhSOD and GhMYB, were differently up-regulated in transgenic lines. Oil contents increased in some transgenic plants, and protein contents reduced compared with transformed receptor. These results suggested that GhDof1 was a functional transcription factor for improving the abiotic tolerance and seed oil content in Upland cotton. Copyright © 2017 Elsevier GmbH. All rights reserved.

  4. Low insulin resistance after surgery predicts poor GH suppression one year after complete resection for acromegaly: a retrospective study.

    Edo, Naoki; Morita, Koji; Suzuki, Hisanori; Takeshita, Akira; Miyakawa, Megumi; Fukuhara, Noriaki; Nishioka, Hiroshi; Yamada, Shozo; Takeuchi, Yasuhiro


    Remission of acromegaly is defined as a nadir in GH GH nadir (GH nadir of 0.4-1.0 ng/mL one year after complete resection of GH-secreting pituitary adenoma (GHoma). We included 110 cases of acromegaly with complete adenoma resection, no preoperative treatment, preoperative glycosylated hemoglobin GH nadir GH nadir GH (GH nadir >0.4 ng/mL). Clinical parameters, including measures of insulin secretion and resistance, were compared between groups. The high GH group included 10 patients (9.1%) and had a lesser level of insulin resistance immediately following surgery and at the first postoperative year evaluation. On single regression analysis, insulin resistance immediately following surgery was predictive of and correlated with the GH nadir at the first postoperative year evaluation. The GH nadir at the first postoperative year evaluation may be insufficient in patients with normalized IGF-1 with low insulin resistance immediately following complete resection of GHoma. Careful evaluation is needed to assess remission in such patients.

  5. Research on Gelcasting Formation of SiC-Al2O3-Y2O3-La2O3 Systems

    郭文利; 徐廷献; 靳正国


    The rheological behavior and gelcasting of composite suspensions of SiC and synthesized Al2O3-Y2O3-La2O3 powder as sintering aid were investigated. It was found that the rheological behavior of SiC particles could be modified with a slightly oxidized surface that was similar to silica in colloidal behavior. The smaller the particles were, the more similar to silica the SiC powder was. The pH value of Al2O3-Y2O3-La2O3 synthesized powder slurry at isoelectric points (IEP) is higher than that of SiC powder. The dispersant PAA-NH4 changes the IEP of both SiC and Al2O3-Y2O3-La2O3 powder slurry to higher pH values. The experimental results indicate that the composite suspension could possess satisfactory stability and lower viscosity at pH =10.1 and PAA-NH4 as dispersant. The optimum solid loading was 5500 in volume. Machinable green bodies with uniform complex shape are gained after molding.

  6. Frustrated pyrochlore oxides, Y2Mn2O7, Ho2Mn2O7, and Yb2Mn2O7: Bulk magnetism and magnetic microstructure

    Greedan, J.E.; Raju, N.P.; Maignan, A.


    The bulk magnetic properties, including de and ac susceptibilities and heat capacity, of the pyrochlore oxides Ho2Mn2O7 and Yb2Mn2O7 are reported and compared with those of the previously studied Y2Mn2O7. In the latter case the magnetic Mn4+ ions occupy the 16c sites in Fd3m which define...... a potentially frustrated three-dimensional array of corner sharing tetrahedra. For Ho2Mn2O7 and Yb2Mn2O7 magnetic rare earth ions occupy the 16d sites, as shown by powder neutron diffraction, which are topologically equivalent to the 16c sites but displaced by a vector (1/2 1/2 1/2). Ho2Mn2O7 and Yb2Mn2O7....... Surprisingly, neutron diffraction data for both Ho2Mn2O7 and Yb2Mn2O7 show resolution limited reflections of magnetic origin in contrast to the heat capacity results. The resolution of the neutron diffraction data places a minimum on the correlation length of 100 Angstrom. Small angle neutron scattering data...

  7. Study of Interfacial Tension between Molten Steel and Na2O-Li2O-SiO2-B2O3 Slag


    The interfacial tension at the Na2O-Li2O-SiO2-B2O3 slag-steel boundary has been determined in the temperature range of 1 803-1 873K by sessile drop method with the transmission X-ray technique. It was found that the variation of interfacial tension with temperature in the system of molten steel/Na2O-Li2O-SiO2-B2O3 slag in the temperature range of 1 803-1 873K is pretty little. The interfacial tension remarkably decreases with increasing the oxygen and/or sulfur content in molten steel. It suggesed that the oxygen and sulfur dissolved in molten steel act as a surface-active solute at the slag-steel interface. Consequently, the interfacial tension depends, in most part, on the oxygen content in molten steel, but the composition of the slag has a minor effect on the interfacial tension. In order to clear the effect of slag composition on the interfacial tension, the experimental results are discussed. The interfacial tension is observed to increase with increasing Na2O and Li2O contents, and decrease with increasing silica content in slag. The influence of B2O3 on the interfacial tension is pretty little.

  8. Research on Properties optimization of humidity sensitive material ZnCr2O4-V2O5-Li2O-ZnO

    FU Heng-lei; XU Tian-hua; SUN Bin


    Humidity-seining properties of humidity-sensitive material ZnCr2O4-V2O5-Li2O-ZnO made from crystal pbase ZnCr2O4.and glass phase LiZnVO4 of different mole ratios Were tested over a long time,synthetic characteristics of different mole ratios are compared,it shows that the best humidity-sensing properties were obtained when mole rataos are 94:6 and 96:4,the cause that mole ratio affects humadity-sensing properties parameters is analyzed.



    In August 1998, an international symposium on the world deltas was held in New Orleans, Louisiana, USA. This symposium attracted discussion about more than 25 deltas from around the world with emphasis placed on those that are most densely populated and impacted by humans. Keynote papers printed details about the physical, biological, engineering and socioeconomic aspects of six deltas including the Mississippi, Nile, Ganges-Brahmaputra, Rhine-Meuse, Changjiang and Po. The main purpose of this symposium was to inform scientists, engineers and decision-makers about information that is currently available and to provide them a basis for working in such environments.


    J.X. Zhang; D.M. Liu; Y.Q. Liu; M.L. Zhou; T.Y. Zuo


    The mechanical properties of molybdenum wires doped with different contents of La2O3 were investigated systematically and the interaction between La2O3 particles with dislocations in MoLa2O3 wires were observed by SEM and TEM. It is shown that Mo-La2O3 wires possess much higher tensile strength than the pure Mo. In wires the dislocation motion is strongly hindered by La2O3 particles, which remains up to much higher temperature. Moreover, a number of prismatic dislocation loops and hexagonal dislocation network have been formed in annealed Mo-La2O3wires. The higher strength of Mo-La2O3 than the pure Mo is attributed to the La2O3 particles dispersion strengthening and dislocation strengthening.

  11. Dynamical Casimir effect with $\\delta-\\delta^{\\prime}$ mirrors

    Silva, Jeferson Danilo L; Alves, Danilo T


    We calculate the spectrum and the total rate of created particles for a real massless scalar field in $1+1$ dimensions, in the presence of a partially transparent moving mirror simulated by a Dirac $\\delta-\\delta^{\\prime}$ point interaction. We show that, strikingly, a partially reflecting mirror can produce a larger number of particles in comparison with a perfectly reflecting one. In the limit of a perfect mirror, our formulas recover those found in the literature for the Robin boundary condition.

  12. Ionic hydrates, M(p)X(q).nH(2)O: lattice energy and standard enthalpy of formation estimation.

    Jenkins, H Donald Brooke; Glasser, Leslie


    This paper is one of a series (see: Inorg. Chem. 1999, 38, 3609; J. Am. Chem. Soc. 2000, 122, 632; Inorg. Chem. 2002, 41, 2364) exploring simple approaches for the estimation of lattice energies of ionic materials, avoiding elaborate computation. Knowledge of lattice energy can lead, via thermochemical cycles, to the evaluation of the underlying thermodynamics involving the preparation and subsequent reactions of inorganic materials. A simple and easy to use equation for the estimation of the lattice energy of hydrate salts, U(POT)(M(p)X(q).nH(2)O) (and therefore for solvated salts, M(p)X(q).nS, in general), using either the density or volume of the hydrate, or of another hydrate, or of the parent anhydrous salt or the volumes of the individual ions, is derived from first principles. The equation effectively determines the hydrate lattice energy, U(POT)(M(p)X(q).nH(2)O), from a knowledge of the (estimated) lattice energy, U(POT)(M(p)X(q)), of the parent salt by the addition of ntheta(U) where theta(U)(H(2)O)/kJ mol(-1) = 54.3 and n is the number of water molecules. The average volume of the water molecule of hydration, V(m)(H(2)O)/nm(3) = 0.0245, has been determined from data on a large series of hydrates by plotting hydrate/parent salt volume differences against n. The enthalpy of incorporation of a gaseous water molecule into the structure of an ionic hydrate, [Delta(f)H degrees (M(p)X(q).nH(2)O,s) - Delta(f)H degrees (M(p)X(q),s) - nDelta(f)H degrees (H(2)O,g)], is shown to be a constant, -56.8 kJ (mol of H(2)O)(-1). The physical implications with regard to incorporation of the water into various types of solid-state structures are considered. Examples are given of the use of the derived hydrate lattice energy equation. Standard enthalpies of formation of a number of hydrates are thereby predicted.

  13. Properties of GH4169 Superalloy Characterized by Nonlinear Ultrasonic Waves

    Hongjuan Yan


    Full Text Available The nonlinear wave motion equation is solved by the perturbation method. The nonlinear ultrasonic coefficients β and δ are related to the fundamental and harmonic amplitudes. The nonlinear ultrasonic testing system is used to detect received signals during tensile testing and bending fatigue testing of GH4169 superalloy. The results show that the curves of nonlinear ultrasonic parameters as a function of tensile stress or fatigue life are approximately saddle. There are two stages in relationship curves of relative nonlinear coefficients β′ and δ′ versus stress and fatigue life. The relative nonlinear coefficients β′ and δ′ increase with tensile stress when tensile stress is lower than 65.8% of the yield strength, and they decrease with tensile stress when tensile stress is higher than 65.8% of the yield strength. The nonlinear coefficients have the extreme values at 53.3% of fatigue life. For the second order relative nonlinear coefficient β′, there is good agreement between the experimental data and the comprehensive model. For the third order relative nonlinear coefficient δ′, however, the experiment data does not accord with the theoretical model.

  14. Long-term effects of growth hormone (GH) replacement therapy on hematopoiesis in a large cohort of children with GH deficiency.

    Esposito, Andrea; Capalbo, Donatella; De Martino, Lucia; Rezzuto, Martina; Di Mase, Raffaella; Pignata, Claudio; Salerno, Mariacarolina


    The aim of our prospective case-control study was to evaluate long-term effects of GH replacement therapy on erythrocytes parameters, leukocytes, and platelets numbers in a large cohort of children with isolated GH deficiency (GHD). Hemoglobin (Hb) concentration, hematocrit (Hct), mean corpuscular volume, mean corpuscular hemoglobin, red cell distribution width, number of erythrocytes, leukocytes, neutrophils, lymphocytes, monocytes and platelets, ferritin, and C-reactive protein were evaluated in 85 children with isolated GHD (10.20 ± 3.50 years) before and annually during the first 5 years of GH replacement therapy and in 85 healthy children age and sex comparable to patients during 5 years of follow-up. Compared with controls, GHD children at study entry showed lower Hb (-1.18 ± 0.87 vs. -0.40 ± 0.90 SDS, p GH therapy was associated with a significant increase in Hb, Hct, and red cells number which became all comparable to controls within the first 2 years of treatment. Moreover, hemoglobin levels normalized in all anemic GHD patients after 5 years of therapy. No difference between patients and controls was found in leukocytes and platelets numbers neither at baseline nor during the study. GHD in childhood is associated with an impairment of erythropoiesis which causes a normocytic anemia in a considerable percentage of patients. GH replacement therapy exerts a beneficial effect leading to a significant increase of erythrocytes parameters and recovery from anemia. Neither GHD nor GH replacement treatment exerts effects on leukocytes or platelets numbers.

  15. pKa modulation of the acid/base catalyst within GH32 and GH68: a role in substrate/inhibitor specificity?

    Shuguang Yuan

    Full Text Available Glycoside hydrolases of families 32 (GH32 and 68 (GH68 belong to clan GH-J, containing hydrolytic enzymes (sucrose/fructans as donor substrates and fructosyltransferases (sucrose/fructans as donor and acceptor substrates. In GH32 members, some of the sugar substrates can also function as inhibitors, this regulatory aspect further adding to the complexity in enzyme functionalities within this family. Although 3D structural information becomes increasingly available within this clan and huge progress has been made on structure-function relationships, it is not clear why some sugars bind as inhibitors without being catalyzed. Conserved aspartate and glutamate residues are well known to act as nucleophile and acid/bases within this clan. Based on the available 3D structures of enzymes and enzyme-ligand complexes as well as docking simulations, we calculated the pKa of the acid-base before and after substrate binding. The obtained results strongly suggest that most GH-J members show an acid-base catalyst that is not sufficiently protonated before ligand entrance, while the acid-base can be fully protonated when a substrate, but not an inhibitor, enters the catalytic pocket. This provides a new mechanistic insight aiming at understanding the complex substrate and inhibitor specificities observed within the GH-J clan. Moreover, besides the effect of substrate entrance on its own, we strongly suggest that a highly conserved arginine residue (in the RDP motif rather than the previously proposed Tyr motif (not conserved provides the proton to increase the pKa of the acid-base catalyst.

  16. GH response to GHRH plus arginine is impaired in lipoatrophic women with human immunodeficiency virus compared with controls.

    Zirilli, Lucia; Orlando, Gabriella; Carli, Federica; Madeo, Bruno; Cocchi, Stefania; Diazzi, Chiara; Carani, Cesare; Guaraldi, Giovanni; Rochira, Vincenzo


    GH secretion is impaired in lipodystrophic human immunodeficiency virus (HIV) patients and inversely related to lipodystrophy-related fat redistribution in men. Less is known about the underlying mechanisms involved in reduced GH secretion in HIV-infected women. A case-control, cross-sectional study comparing GH/IGF1 status, body composition, and metabolic parameters in 92 nonobese women with HIV-related lipodystrophy and 63 healthy controls matched for age, ethnicity, sex, and body mass index (BMI). GH, IGF1, IGF binding protein 3 (IGFBP3), GH after GHRH plus arginine (GHRH+Arg), several metabolic variables, and body composition were evaluated. GH response to GHRH+Arg was lower in HIV-infected females than in controls. Using a cutoff of peak GH ≤ 7.5 μg/l, 20.6% of HIV-infected females demonstrated reduced peak GH response after GHRH+Arg. In contrast, none of the control subjects demonstrated a peak GH response ≤ 7.5 μg/l. Bone mineral density (BMD), quality of life, IGF1, and IGFBP3 were lowest in the HIV-infected females with a GH peak ≤ 7.5 μg/l. BMI was the main predictive factor of GH peak in stepwise multiregression analysis followed by age, with a less significant effect of visceral fat in the HIV-infected females. This study establishes that i) GH response to GHRH+Arg is lower in lipoatrophic HIV-infected women than in healthy matched controls, ii) BMI more than visceral adipose tissue or trunk fat influences GH peak in this population, and iii) HIV-infected women with a GH peak below or equal to 7.5 μg/l demonstrate reduced IGF1, IGFBP3, BMD, and quality of life.

  17. Preweaning GH Treatment Normalizes Body Growth Trajectory and Reverses Metabolic Dysregulation in Adult Offspring After Maternal Undernutrition.

    Li, Minglan; Reynolds, Clare M; Gray, Clint; Vickers, Mark H


    Maternal undernutrition (UN) results in growth disorders and metabolic dysfunction in offspring. Although dysregulation of the GH-IGF axis in offspring is a known consequence of maternal UN, little is known about the efficacy of GH treatment during the period of developmental plasticity on later growth and metabolic outcomes. The present study investigated the effect of preweaning GH treatment on growth, glucose metabolism, and the GH-IGF axis in adult male and female offspring after maternal UN. Female Sprague Dawley rats were fed either a chow diet ad libitum (control [CON]) or 50% of ad libitum (UN) throughout pregnancy. From postnatal day 3, CON and UN pups received either saline (CON-S and UN-S) or GH (2.5 μg/g·d CON-GH and UN-GH) daily throughout lactation. At weaning, male and female offspring were randomly selected from each litter and fed a standard chow diet for the remainder of the study. Preweaning GH treatment normalized maternal UN-induced alterations in postweaning growth trajectory and concomitant adiposity in offspring. Plasma leptin concentrations were increased in UN-S offspring and normalized in the UN-GH group. Hepatic GH receptor expression was significantly elevated in UN-S offspring and normalized with GH treatment. Hepatic IGF binding protein-2 gene expression and plasma IGF-1 to IGF binding protein-3 ratio was reduced in UN-S offspring and elevated with GH treatment. GH treatment during a critical developmental window prevented maternal UN-induced changes in postnatal growth patterns and related adiposity, suggesting that manipulation of the GH-IGF-1 axis in early development may represent a promising avenue to prevent adverse developmental programming effects in adulthood.

  18. Identification of novel GH-regulated pathway of lipid metabolism in adipose tissue: a gene expression study in hypopituitary men.

    Zhao, Jing Ting; Cowley, Mark J; Lee, Paul; Birzniece, Vita; Kaplan, Warren; Ho, Ken K Y


    Adipose tissue is a major target of GH action. GH stimulates lipolysis and reduces fat mass. The molecular mechanism underlying cellular and metabolic effects of GH in adipose tissue is not well understood. The aim of this study is to identify GH-responsive genes that regulate lipid metabolism in adipose tissue. Eight men with GH deficiency underwent measurement of plasma free fatty acid (FFA), whole-body lipid oxidation, and fat biopsies before and after 1 month of GH treatment (0.5 mg/d). Gene expression profiling was performed using Agilent 44K G4112F arrays using a two-color design. Differentially expressed genes were identified using an empirical Bayes, moderated t test, with a false discovery rate under 5%. Target genes were validated by quantitative RT-PCR. GH increased circulating IGF-I and FFA and stimulated fat oxidation. A total of 246 genes were differentially expressed, of which 135 were up-regulated and 111 down-regulated. GH enhanced adipose tissue expression of IGF-I and SOCS3. GH increased expression of patatin-like phospholipase domain containing 3 (PNPLA3), a novel triglyceride (TG) hydrolase, but not hormone-sensitive lipase (HSL), a classical TG hydrolase. GH repressed cell death-inducing DFFA-like effector A (CIDEA), a novel lipid droplets-associated protein, promoting TG storage. GH differentially regulated genes promoting diacylglycerol synthesis. GH suppressed hydroxysteroid (11β) dehydrogenase 1, which activates local cortisol production and genes encoding components of extracellular matrix and TGF-β signaling pathway. GH stimulates the TG/FFA cycle by regulating the expression of novel genes that enhance TG hydrolysis, reduce TG storage, and promote diacylglycerol synthesis. GH represses adipocyte growth, differentiation and inflammation.

  19. El uso de la distribución g-h en riesgo operativo

    Andrés Mora Valencia


    Full Text Available Este artículo presenta una revisión del uso de la distribución g-h en riesgo operativo; asimismo, se propone una modifica - ción al método de Hoaglin (1985 para la estimación de los parámetros de la distribución g-h . La diferencia consiste en realizar una regresión robusta cuando se estima el parámetro h ; además, se realizan comparaciones de estimados de OpVaR mediante g-h y POT en dos aplicaciones. Los resultados mues - tran que el empleo del método g-h es de gran utilidad en riesgo operativo, pero debe tenerse cuidado cuando la distribución de las pérdidas exhiben colas extremadamente pesadas.

  20. Survival function Of Realization process for Hemodynamic and hormonal effects of human GH in healthy volunteers



    Full Text Available Hemodynamic and hormonal effects of human ghrelin in healthy volunteers. To investigate hemodynamic and hormonal effects of ghrelin, a novel growth hormone (GH-releasing peptide, we gave six healthy men an intravenous bolus of human ghrelin or placebo and vice versa 1–2 wk apart in a randomized fashion. Ghrelin elicited a marked increase in circulating GH. The elevation of GH lasted longer than 60 min after the bolus injection. Injection of ghrelin significantly decreased mean arterial pressure without a significant change in heart rate .In summary, human ghrelin elicited a potent, long lasting GH release and had beneficial hemodynamic effects via reducing cardiac after load and increasing cardiac output without an increase in heart rate. Thus, the purpose of this study was to investigate hemodynamic and hormonal effects of intravenous ghrelin in healthy volunteers. This paper discussed the constant stress level of healthy volunteers with times to damage of stress effect and recoveries

  1. Structural Basis for Prereceptor Modulation of Plant Hormones by GH3 Proteins

    Westfall, Corey S.; Zubieta, Chloe; Herrmann, Jonathan; Kapp, Ulrike; Nanao, Max H.; Jez, Joseph M. (WU); (EMBL); (ESRF)


    Acyl acid amido synthetases of the GH3 family act as critical prereceptor modulators of plant hormone action; however, the molecular basis for their hormone selectivity is unclear. Here, we report the crystal structures of benzoate-specific Arabidopsis thaliana AtGH3.12/PBS3 and jasmonic acid-specific AtGH3.11/JAR1. These structures, combined with biochemical analysis, define features for the conjugation of amino acids to diverse acyl acid substrates and highlight the importance of conformational changes in the carboxyl-terminal domain for catalysis. We also identify residues forming the acyl acid binding site across the GH3 family and residues critical for amino acid recognition. Our results demonstrate how a highly adaptable three-dimensional scaffold is used for the evolution of promiscuous activity across an enzyme family for modulation of plant signaling molecules.

  2. Immunohistochemical detection of growth hormone (GH) in canine hepatoid gland tumors.

    Petterino, Claudio; Martini, Marco; Castagnaro, Massimo


    The aim of this study was to detect immunohistochemically means growth hormone (GH) in 24 hepatoid gland adenomas and 5 hepatoid gland carcinomas and to compare the difference of immunoreactivity between types of tumors. The tumors were classified according to the WHO standards. Tissue sections which were prepared from formalin-fixed, paraffin wax-embedded tissues from 25 male and 4 female dogs were carried out immunostaining using polyclonal primary anti-hGH and EnVision method. Of 24 hepatoid gland adenomas (perianal gland adenomas) 23 (95.8%) were positive. All 5 hepatoid gland carcinomas (perianal gland carcinomas) were positive. No statistically significant differences in percentage of labelled cells between malignant and benign tumors were seen. The present demonstration of GH in hepatoid gland tumors adds new data on GH in extra-pituitary tissues and hormon-dependent tumors.

  3. Diagnosis and treatment of GH deficiency in Prader-Willi syndrome.

    Grugni, Graziano; Marzullo, Paolo


    Prader-Willi syndrome (PWS) results from under-expression of the paternally-derived chromosomal region 15q11-13. Growth failure is a recognized feature of PWS, and both quantitative and qualitative defects of the GH/IGF-I axis revealing GH deficiency (GHD) have been demonstrated in most children with PWS. In PWS adults, criteria for GHD are biochemically fulfilled in 8-38% of the studied cohorts. Published data support benefits of early institution of GH therapy (GHT) in PWS children, with positive effects on statural growth, body composition, metabolic homeostasis, and neurocognitive function. Like in pediatric PWS, GHT also yields beneficial effects on lean and body fat, exercise capacity, and quality of life of PWS adults. Although GHT has been generally administered safely in PWS children and adults, careful surveillance of risks is mandatory during prolonged GH replacement for all PWS individuals.

  4. Impact of estradiol supplementation on dual peptidyl drive of GH secretion in postmenopausal women.

    Veldhuis, J D; Evans, W S; Bowers, C Y


    As an indirect probe of estrogen-regulated hypothalamic somatostatin restraint, the present study monitors the ability of short-term oral E2 supplementation to modulate GH secretion during combined continuous stimulation by recombinant human GHRH [GHRH-(1-44)-amide] and the potent and selective synthetic GH-releasing peptide, GHRP-2. According to a simplified tripeptidyl model of GH neuroregulation, the effects of estrogen in this dual secretagogue paradigm should mirror alterations in endogenous somatostatinergic signaling. To this end, seven healthy postmenopausal women underwent frequent (10-min) blood sampling for 24 h during simultaneous i.v. infusion of GHRH and GHRP-2 each at a rate of 1 microg/kg x h on d 10 of randomly ordered placebo or 17beta-estradiol (E2) (1 mg orally twice daily) replacement. Serum GH concentrations (n = 280/subject) were assayed by chemiluminescence. The resultant GH time series was evaluated by deconvolution analysis, the approximate entropy statistic, and cosine regression to quantitate pulsatile, entropic (feedback-sensitive), and 24-h rhythmic GH release, respectively. Statistical comparisons revealed that E2 repletion increased the mean (+/- SEM) serum E2 concentration to 222 +/- 26 pg/ml from 16 +/- 1.7 pg/ml during placebo (P entropic, or nyctohemeral GH secretion monitored under continuous combined drive by GHRH and GHRP-2. As E2 repletion without enforced GHRH/GHRP-2 stimulation augments each of the foregoing regulated facets of GH release, we infer that one or both of the infused peptidyl secretagogues may itself participate in E2's short-term amplification of GH secretion in postmenopausal individuals. Estrogen's disruption of the orderliness of sequential GH pulse-mass values during fixed GHRH/GHRP-2 feedforward would be consistent with a subtle reduction in the release and/or actions of hypothalamic somatostatin or an (unexpected) direct pituitary action of the sex steroid. Whether comparable dynamics mediate the effects

  5. GH receptor blocker administration and muscle-tendon collagen synthesis in humans

    Nielsen, Rie Harboe; Doessing, Simon; Goto, Kazushige;


    The growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis stimulates collagen synthesis in tendon and skeletal muscle, but no studies have investigated the effect of reducing IGF-I on collagen synthesis in healthy humans.......The growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis stimulates collagen synthesis in tendon and skeletal muscle, but no studies have investigated the effect of reducing IGF-I on collagen synthesis in healthy humans....

  6. Preclinical and Clinical In Vitro In Vivo Correlation of an hGH Dextran Microsphere Formulation


    Purpose To investigate the in vitro in vivo correlation of a sustained release formulation for human growth hormone (hGH) based on hydroxyethyl methacrylated dextran (dex-HEMA) microspheres in Pit-1 deficient Snell dwarf mice and in healthy human volunteers. Materials and Methods A hGH-loaded microsphere formulation was developed and tested in Snell dwarf mice (pharmacodynamic study) and in healthy human volunteers (pharmacokinetic study). Results Single subcutaneous administration of the mic...

  7. Effects of dietary genistein on GH/IGF-I axis of Nile tilapia Oreochromis niloticus

    Chen, Dong; Wang, Wei; Ru, Shaoguo


    There is considerable concern that isoflavones, such as genistein in fish feed composed of soybean protein, aff ects somatic growth in fish. Our previous works demonstrated that 30 and 300 μg/g dietary genistein had no significant eff ect on growth performance in Nile tilapia ( Oreochromis niloticus), but the higher level of genistein (3 000 μg/g) significantly depressed growth. This study was conducted to further examine the eff ects of dietary genistein on the endocrine disruption on growth hormone/insulin-like growth factor-I (GH/IGF-I) axis in Nile tilapia ( O. niloticus). Juvenile fish were fed by hand twice daily to satiation with one of four isonitrogenous and isoenergetic diets, each containing either 0, 30, 300 or 3 000 μg/g genistein. Following an 8-week feeding period, plasma GH and IGF-I levels were investigated by radioimmunoassay and gene expression levels of gh, ghrelin, gnrhs, ghr, npy, npyrs, pacap, ghrs, i gf-I, igf-Ir, and igfbp3 were examined by real-time PCR. The results show that no significant change in plasma GH and IGF-I levels in fish fed with diets containing 30 μg/g and 300 μg/g genistein. mRNA expression of genes along the GH/IGF-I axis remained unaff ected, except for igf-Ir, which was stimulated by the 300 μg/g genistein diet. While in fish fed the 3 000 μg/g genistein diet, the plasma GH and IGF-I levels decreased, and mRNA expression of gh, ghr2, npyr1, igf-I, and igf-Ir were also significantly depressed. In contrast, npy and igfbp3 mRNA expression were enhanced. This study provides convincing evidence for growth impediment by genistein by disturbing the GH/IGF-I axis in Nile tilapia O. niloticus.


    Mert Gürgen


    Full Text Available This article describes a sophisticated determination and presentation of a workspace volume for a delta robot, with consideration of its kinematic behavior. With the help of theoretical equations, optimization is performed with the aid of the stiffness and dexterity analysis. Theoretical substructure is coded in Matlab and three-dimensional (3D data for delta robot are developed in computer-aided design (CAD environment. In later stages of the project, both 3D and theoretical data are linked together and thus, with the changing design parameter of the robot itself, the Solidworks CAD output adapts and regenerates output with a new set of parameters. To achieve an optimum workspace volume with predefined parameters, a different set of robot parameters are iterated through design optimization in Matlab, and the delta robot design is finalized and illustrated in the 3D CAD environment, Solidworks. This study provides a technical solution to accomplish a generic delta robot with optimized workspace volume.

  9. Partial oxidation of dimethyl ether using the structured catalyst Rh/Al2O3/Al prepared through the anodic oxidation of aluminum.

    Yu, B Y; Lee, K H; Kim, K; Byun, D J; Ha, H P; Byun, J Y


    The partial oxidation of dimethyl ether (DME) was investigated using the structured catalyst Rh/Al2O3/Al. The porous Al2O3 layer was synthesized on the aluminum plate through anodic oxidation in an oxalic-acid solution. It was observed that about 20 nm nanopores were well developed in the Al2O3 layer. The thickness of Al2O3 layer can be adjusted by controlling the anodizing time and current density. After pore-widening and hot-water treatment, the Al2O3/Al plate was calcined at 500 degrees C for 3 h. The obtained delta-Al2O3 had a specific surface area of 160 m2/g, making it fit to be used as a catalyst support. A microchannel reactor was designed and fabricated to evaluate the catalytic activity of Rh/Al2O3/Al in the partial oxidation of DME. The structured catalyst showed an 86% maximum hydrogen yield at 450 degrees C. On the other hand, the maximum syngas yield by a pack-bed-type catalyst could be attained by using a more than fivefold Rh amount compared to that used in the structured Rh/Al2O3/Al catalyst.

  10. Synthesis and structural characterization of (Bi2O3)1– (Y2O3) and (Bi2O3)1– (Gd2O3) solid solutions

    Srikant Ekhelikar; G K Bichile


    Solid solution series, (Bi2O3)1– (Y2O$_3) and (Bi2O$_3)1– (Gd2O$_3), for = 0.10, 0.20, 0.30 and 0.40 were synthesized by standard ceramic technique. The structural phase characterization was carried out using X-ray powder diffraction technique. It was found that the solid solution containing 20–40 mole% of Y2O3 had face-centred cubic structure. All samples of the solid solution series, (Bi2O3)1– (Gd2O3), had rhombohedral single phase in the concentration range 0.10 ≤ ≤ 0.40. Lattice parameters of fcc phase of Y2O3 doped samples were calculated from the X-ray diffraction data. The lattice constant `’ gradually decreases with increasing content of dopant concentration () for the Y2O3 doped system and obeys Vegard’s rule. The unit cell parameters for the (Bi2O3)1– (Gd2O3) doped samples showing rhombohedral phase were obtained on hexagonal setting.

  11. Thermoresponsive behaviour of AM sub 2 O sub 8 materials

    Allen, S


    This thesis investigates the synthesis and structural characterisation of AM sub 2 O sub 8 phases, many of which show negative thermal expansion (NTE); relevant literature is reviewed in Chapter One. Chapter Two describes the synthesis, structure solution, and mechanistic role of a new family of low-temperature (LT) orthorhombic AM sub 2 O sub 8 polymorphs (A sup I sup V = Zr, Hf; M sup V sup I = Mo, W). These materials are key intermediates in the preparation of cubic AM sub 2 O sub 8 phases from AM sub 2 O sub 7 (OH) sub 2 (H sub 2 O) sub 2. The structure of LT-AM sub 2 O sub 8 has been elucidated by combined laboratory X-ray and neutron powder diffraction. Variable temperature X-ray diffraction (VTXRD) studies have shown LT-AMo sub 2 O sub 8 phases exhibit anisotropic NTE. LT-ZrMo sub 2 O sub 8 has been shown to undergo spontaneous rehydration, allowing preparation of ZrMo sub 2 O sub 7 (OD) sub 2 (D sub 2 O) sub 2 and assignment of D sub 2 O/OD positions within the structure by neutron diffraction. Using ...

  12. Greenhouse gas (N2O emission from Portuguese estuaries

    Célia Gonçalves


    Tagus, Minho and Lima estuaries are source of N2O to the atmosphere. Particularly, in Lima estuary anthropogenic N input seems to play an important role on N2O emission. However, in a global perspective N2O attained emissions represent a reduced fraction (2O yr-1, Barnes and Upstill-Goddard, 2011. Values are comparable with those registered in some Portuguese estuaries and other European less eutrophic estuaries. However, it is known that higher N2O emissions in estuaries may occur during winter and spring (Sun et al., 2014. Thus, these systems may represent on an annual basis a larger source of N2O, which can only be clarified in future studies. Only a full comprehension of the global estuarine nitrogen cycle will provide an efficient basis of scientific knowledge for sustainably management of such ecosystems and ultimately reduce N2O emissions.

  13. The Optical Properties of Nanostructured Ta2O5 Films

    Minmin Zhu; Wei Miao; Zhengjun Zhang


    Amorphous Ta2O5 films were prepared on Si (100) substrates by thermal oxidization. The film consisted of amorphous Ta2O5 nanostructure that grew vertically and compactly at a large range. It was found that Ta2O5 films became crystalline when annealed at or above 650℃ and remained amorphous below 650℃. The effects of annealing on the optical properties of Ta2O5 film were also discussed. It is estimated that the refraction indexes and the optical energy gaps of both amorphous Ta2O5 film and crystal one are stable. The optical energy gap of as-deposited Ta2O5 film is about 4.81 eV. The above results indicate that Ta2O5 films have a promising application in the optical devices.

  14. Effect of Ce2O3 on Structure, Viscosity, and Crystalline Phase of CaO-Al2O3-Li2O-Ce2O3 Slags

    Qi, Jie; Liu, Chengjun; Zhang, Chi; Jiang, Maofa


    Aiming at devising new mold flux for Ce-bearing stainless steel, a fundamental investigation on the effect of Ce2O3 on properties of the CaO-Al2O3-Li2O-Ce2O3 slag was provided by the present work. The results show that adding Ce2O3 could decrease the viscosity of the slag due to its effects on decreasing the polymerization of the slag. The crystalline process was restrained by increasing the content of Ce2O3, and the crystalline phases also can be influenced by the slag structure. The crystalline phases were transferred from LiAlO2 and CaO to LiAlO2 and CaCeAlO4 with the addition of Ce2O3 to the slag, which could be well confirmed by the structure of the unit cell of the crystals.

  15. Growth hormone (GH) secretory dynamics in a case of acromegalic gigantism associated with hyperprolactinemia: nonpulsatile secretion of GH may induce elevated insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 levels.

    Yoshida, T; Shimatsu, A; Sakane, N; Hizuka, N; Horikawa, R; Tanaka, T


    We describe a case of pituitary gigantism with low levels of growth hormone (GH), elevated insulin-like growth factor-I (IGF-I), and IGF-binding protein-3 (IGF-BP-3). The patient had characteristic clinical features of gigantism and acromegaly. The basal serum GH levels ranged from 1.2-1.9 micrograms/L, which were considered to be within normal limits. Serum GH response to either insulin-induced hypoglycemia or GH-releasing hormone was blunted. Frequent blood samplings during daytime and at night showed nonpulsatile GH secretion. Serum prolactin, IGF-I and IGF-binding protein-3 levels were elevated. After unsuccessful surgery, bromocryptine treatment normalized serum prolactin without affecting serum GH and IGF-I levels. Combined administration of octreotide and bromocryptine reduced serum GH and IGF-I levels. GH bioactivity as measured by Nb2 cell proliferation assay was within reference range. In the present case, nonpulsatile GH secretion and enhanced tissue sensitivity to GH may induce hypersecretion of IGF-I and IGF-BP-3 and cause clinical acromegalic gigantism.

  16. GH3-Mediated Auxin Conjugation Can Result in Either Transient or Oscillatory Transcriptional Auxin Responses.

    Mellor, Nathan; Bennett, Malcolm J; King, John R


    The conjugation of the phytohormone auxin to amino acids via members of the gene family GH3 is an important component in the auxin-degradation pathway in the model plant species Arabidopsis thaliana, as well as many other plant species. Since the GH3 genes are themselves up-regulated in response to auxin, providing a negative feedback on intracellular auxin levels, it is hypothesised that the GH3s have a role in auxin homoeostasis. To investigate this, we develop a mathematical model of auxin signalling and response that includes the auxin-inducible negative feedback from GH3 on the rate of auxin degradation. In addition, we include a positive feedback on the rate of auxin input via the auxin influx transporter LAX3, shown previously to be expressed in response to auxin and to have an important role during lateral root emergence. In the absence of the LAX3 positive feedback, we show that the GH3 negative feedback suffices to generate a transient transcriptional response to auxin in the shape of damped oscillations of the model system. When LAX3 positive feedback is present, sustained oscillations of the system are possible. Using steady-state analyses, we identify and discuss key parameters affecting the oscillatory behaviour of the model. The transient peak of auxin and subsequent transcriptional response caused by the up-regulation of GH3 represents a possible protective homoeostasis mechanism that may be used by plant cells in response to excess auxin.

  17. G/H M-branes and $AdS_{p+2}$ Geometries

    Castellani, Leonardo; D'Auria, Riccardo; Ferrara, Sergio; Fre, Pietro; Trigiante, Mario


    We prove the existence of a new class of BPS saturated M-branes. They are in one-to-one correspondence with the Freund--Rubin compactifications of M-theory on either (AdS_4) x (G/H) or (AdS_7) x (G/H), where G/H is the seven (or four) dimensional Einstein coset manifolds classified long ago in the context of Kaluza Klein supergravity. The G/H M-branes are solitons that interpolate between flat space at infinity and the old Kaluza-Klein compactifications at the horizon. They preserve N/2 supersymmetries where N is the number of Killing spinors of the (AdS) x (G/H) vacuum. A crucial ingredient in our discussion is the identification of a solvable Lie algebra parametrization of the Lorentzian non compact coset SO(2,p+1)/SO(1,p+1) corresponding to anti de Sitter space AdS_{p+2} . The solvable coordinates are those naturally emerging from the near horizon limit of the G/H p-brane and correspond to the Bertotti Robinson form of the anti-de-Sitter metric. The pull-back of anti-de-Sitter isometries on the p-brane wor...

  18. Effect of Phosphorus on Stress Rupture Properties of GH4133 Ni-Base Superalloy

    Wenru SUN; Shouren GUO; Baiyun TONG; Dezhong LU; Yan XU; Xiaona MENG; Na LI; Zhuangqi HU


    The effect of phosphorus on the stress rupture property of GH4133 alloy has been investigated and is compared with that of IN718 alloy. The GH4133 alloy is crept by dislocation movement. Phosphorus has a tendency to prolong the rupture life of some wrought superalloys by inhibiting the dislocation movement. If the phosphorus addition is too high, its effect on impairing the grain boundary cohesion overwhelms that on inhibiting the dislocation movement,and the life of the GH4133 alloy can be shortened. The two functions of inhibiting the dislocation movement and impairing the grain boundary cohesion determine that the optimum phosphorus content in the GH4133 alloy is around 0.011 wt pct. Phosphorus exhibits a greater effect on prolonging the rupture life of IN718 alloy than that of GH4133alloy. The two alloys are crept by different mechanisms. The intergranular phosphorus-bearing phase is precipitated in the IN718 alloy, while not in the GH4133 alloy. The precipitation of the phosphorus bearing phase can balance the phosphorus segregation at the grain boundaries and allows a more remarkable effect of phosphorus on extending the rupture life of IN718 alloy.

  19. Dwarfism and increased adiposity in the gh1 mutant zebrafish vizzini.

    McMenamin, Sarah K; Minchin, James E N; Gordon, Tiffany N; Rawls, John F; Parichy, David M


    Somatic growth and adipogenesis are closely associated with the development of obesity in humans. In this study, we identify a zebrafish mutant, vizzini, that exhibits both a severe defect in somatic growth and increased accumulation of adipose tissue. Positional cloning of vizzini revealed a premature stop codon in gh1. Although the effects of GH are largely through igfs in mammals, we found no decrease in the expression of igf transcripts in gh1 mutants during larval development. As development progressed, however, we found overall growth to be progressively retarded and the attainment of specific developmental stages to occur at abnormally small body sizes relative to wild type. Moreover, both subcutaneous (sc) and visceral adipose tissues underwent precocious development in vizzini mutants, and at maturity, the sizes of different fat deposits were greatly expanded relative to wild type. In vivo confocal imaging of sc adipose tissue (SAT) expansion revealed that vizzini mutants exhibit extreme enlargement of adipocyte lipid droplets without a corresponding increase in lipid droplet number. These findings suggest that GH1 signaling restricts SAT hypertrophy in zebrafish. Finally, nutrient deprivation of vizzini mutants revealed that SAT mobilization was greatly diminished during caloric restriction, further implicating GH1 signaling in adipose tissue homeostasis. Overall, the zebrafish gh1 mutant, vizzini, exhibits decreased somatic growth, increased adipose tissue accumulation, and disrupted adipose plasticity after nutrient deprivation and represents a novel model to investigate the in vivo dynamics of vertebrate obesity.

  20. {delta}-FeOOH: a superparamagnetic material for controlled heat release under AC magnetic field

    Chagas, Poliane; Candido da Silva, Adilson [ICEx, Universidade Federal de Minas Gerais, Departamento de Quimica (Brazil); Caetano Passamani, Edson [Universidade Federal do Espirito Santo, Departamento de Fisica (Brazil); Ardisson, Jose Domingos [Centro de Desenvolvimento da Tecnologia Nuclear (Brazil); Alves de Oliveira, Luiz Carlos [ICEx, Universidade Federal de Minas Gerais, Departamento de Quimica (Brazil); Domingos Fabris, Jose [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) (Brazil); Paniago, Roberto M. [ICEx, Universidade Federal de Minas Gerais, Departamento de Fisica (Brazil); Monteiro, Douglas Santos; Pereira, Marcio Cesar, E-mail: [Instituto de Ciencia, Engenharia e Tecnologia, UFVJM (Brazil)


    Experimental evidences on its in vitro use reveal that {delta}-FeOOH is a material that release-controlled amount of heat if placed under an AC magnetic field. {delta}-FeOOH nanoparticles were prepared by precipitating Fe(OH){sub 2} in alkaline solution followed by fast oxidation with H{sub 2}O{sub 2}. XRD and {sup 57}Fe Moessbauer spectroscopy data confirmed that {delta}-FeOOH is indeed the only iron-bearing compound in the produced sample. TEM images evidence that the averaged particle sizes for this {delta}-FeOOH sample is 23 nm. Magnetization measurements indicate that these {delta}-FeOOH particles behave superparamagnetically at 300 K; its saturation magnetization was found to be 13.2 emu g{sup -1}; the coercivity and the remnant magnetization were zero at 300 K. The specific absorption rate values at 225 kHz were 2.1, 6.2, and 34.2 W g{sup -1}, under 38, 64, and 112 mT, respectively. The release rate of heat can be directly controlled by changing the mass of {delta}-FeOOH nanoparticles. In view of these findings, the so-prepared {delta}-FeOOH is a real alternative to be further tested as a material for medical practices in therapies involving magnetic hyperthermia as in clinical oncology.

  1. Development of a Transnasal Delivery System for Recombinant Human Growth Hormone (rhGH): Effects of the Concentration and Molecular Weight of Poly-L-arginine on the Nasal Absorption of rhGH in Rats.

    Kawashima, Ryo; Uchida, Masaki; Yamaki, Tsutomu; Ohtake, Kazuo; Hatanaka, Tomomi; Uchida, Hiroyuki; Ueda, Hideo; Kobayashi, Jun; Morimoto, Yasunori; Natsume, Hideshi


    A novel system for delivering recombinant human growth hormone (rhGH) that is noninvasive and has a simple method of administration is strongly desired to improve the compliance of children. The aim of this study was to investigate the potential for the intranasal (i.n.) co-administration of rhGH with poly-L-arginine (PLA) as a novel delivery system by evaluating the effects of the concentration and molecular weight of PLA on the nasal absorption of rhGH. The influence of the formation of insoluble aggregates and a soluble complex in the dosage formulation on nasal rhGH absorption was also evaluated by size-exclusion chromatography and ultrafiltration. PLA enhanced the nasal absorption of rhGH at each concentration and molecular weight examined. Nasal rhGH absorption increased dramatically when the PLA concentration was 1.0 % (w/v) due to the improved solubility of rhGH in the formulation. A delay in rhGH absorption was observed when the molecular weight of PLA was increased. This appeared to be because the increase in molecular weight caused the formation of a soluble complex. It seems that the PLA concentration affects the absorption-enhancing effect on rhGH, while the molecular weight of PLA affects the time when the maximum plasma rhGH concentration was reached (Tmax) of rhGH after i.n. administration, mainly because of the interactions among rhGH, PLA, and additives. Therefore, the transnasal rhGH delivery system using PLA is considered to be a promising alternative to subcutaneous (s.c.) injection if these interactions are sufficiently controlled.

  2. H2O2 space shuttle APU


    A cryogenic H2-O2 auxiliary power unit (APU) was developed and successfully demonstrated. It has potential application as a minimum weight alternate to the space shuttle baseline APU because of its (1) low specific propellant consumption and (2) heat sink capabilities that reduce the amount of expendable evaporants. A reference system was designed with the necessary heat exchangers, combustor, turbine-gearbox, valves, and electronic controls to provide 400 shp to two aircraft hydraulic pumps. Development testing was carried out first on the combustor and control valves. This was followed by development of the control subsystem including the controller, the hydrogen and oxygen control valves, the combustor, and a turbine simulator. The complete APU system was hot tested for 10 hr with ambient and cryogenic propellants. Demonstrated at 95 percent of design power was 2.25 lb/hp-hr. At 10 percent design power, specific propellant consumption was 4 lb/hp-hr with space simulated exhaust and 5.2 lb/hp-hr with ambient exhaust. A 10 percent specific propellant consumption improvement is possible with some seal modifications. It was demonstrated that APU power levels could be changed by several hundred horsepower in less than 100 msec without exceeding allowable turbine inlet temperatures or turbine speed.

  3. Decomposition mechanisms and non-isothermal kinetics of LiHC_2O_4·H_2O


    The thermal decomposition process of LiHC2O4·H2O from 30 to 600 ℃ was investigated by the thermogravimetric and differential scanning calorimetry (TG-DSC). The phases decomposited at different temperature were characterized by X-ray diffraction (XRD), which indicated the decompositions at 150, 170, and 420℃, relating to LiHC2O4, Li2C2O4, Li2C2O4, and Li2CO3, respectively. Reaction mechanisms in the whole sintering process were determined, and the model fitting kinetic approaches were applied to data for non...

  4. Structural investigation of V$_2$O$_5$–P$_2$O$_5$–K$_2$O glass system with antibacterial potential



    The $x$V$_2$O($1 − x$)[0.8 P$_2$O$_5$·0.2K$_2$O] glass system with $0 \\lt x \\lt 50$ mol% was prepared and the structural changes induced in these glasses by increasing the vanadium oxide content were investigated by IR and ESR spectroscopies. The dual behaviour role of V$_2$O$_5$ oxide, as network modifier (for $x\\lt 10$ mol%) and the network former ($x\\gt 20$ mol%), as a consequence of phosphate network depolymerization and P–O–V and V–O–V linkages appearance was also highlighted. The antibacterial effect of the glasses with $x \\lt 20$ mol% V$_2$O$_5$ content was tested by optical density (OD) measurements. A linear correlation between the amount of vanadium and the antibacterial effect was evidenced.

  5. Structure, dielectric and bioactivity of P2O5-CaO-Na2O-B2O3 bioactive glass

    Maheswaran, A.; Hirankumar, G.; Heller, Nithya; Karthickprabhu, S.; Kawamura, Junichi


    Bioactive phosphate glasses have been widely investigated for bone repair. Phosphate glass system of 47P2O5-30.5CaO-(22.5-x)Na2O-xB2O3 has been prepared by melt quenching technique. From the Raman analysis, it is confirmed that phosphate network form metaphosphate structure. Bioactivity of the glass is studied by immersing the prepared glass in simulated body fluid (SBF). All the glasses exhibited bioactivity after soaking in SBF. Addition of B2O3 to the glass by replacing the Na2O produces considerable effect on the dielectric and bioactivity of the glass. Ion dynamics are also analyzed through imaginary modulus and imaginary dielectric permittivity.

  6. Structural studies of xLi2O-(40 - x)Bi2O3-20CdO-40B2O3 glasses

    Vijaya Kumar, R.; Gayathri Pavani, P.; Ramesh, B.; Shareefuddin, Md.; Siva Kumar, K.


    Raman and infrared spectroscopies have been employed to investigate the xLi2O-(40 - x)Bi2O3-20CdO-40B2O3 glasses in order to obtain information about the competitive role of Bi2O3 and B2O3 in the formation of glass network. IR and Raman spectra show that these glasses are made up of [BO3], [BO4] and [BiO3] pyramidal and [BiO6] octahedral units. The formation of CdO4 in tetrahedral co-ordination was not observed. The optical absorption studies revealed that the cut-off wavelength decreases while optical band gap energy (Eopt) increases. The average electronic polarizability of the oxide ion (α), optical basicity Λ(Eopt), and Yamashita-Kurosawa's interaction parameter A(Eopt) were also examined.

  7. Catalytic Synthesis of Tert-Butyl Acetate by Nd2O3/Al2O3-Nd2O3/ZnO

    Wang Yajun; Han Limin; A Shan


    Nd2O3 was used to support Al2O3 and ZnO to prepare a supported solid base catalyst and investigate the effect of catalyst and reaction conditions on the synthesis of tert-butyl acetate. The composited oxide of Nd2O3/Al2O3-Nd2O3/ZnO exhibited excellent catalytic activity for the synthsis of tert-butyl acetate. The molar ratio of tert-butanol to acetic anhydride is 3:1, the catalyst in total amount of reactant nearly 0.5%, and reaction time 6 h. With the above conditions, yield of the reaction could reach to 65%. The structure of product were verified by the FT-IR, Element analysis, and MS, which proved that the product was tert-butyl acetate.

  8. Physical-chemical examination of the N2O3-SO3-H2O system

    Linstroem, C.; Malyska, G.


    It was found that when (NO)HSO4 is added to absolute H2SO4, specific conductivity rises sharply, possibly due to an increase in mutual interionic effects and viscosity as the (NO)HSO4 concentration rises. The addition of SO3 to the solution yielded a precipitate; a combination of analysis, IR spectroscopy and X-ray diffraction techniques indicated that this precipitate was (NO)HS2O7.

  9. Acidity Measurements with the Glass Electrode in H2O-D2O Mixtures

    Mikkelsen, K.; Nielsen, Sigurd Olaf


    to variations in the hydrogen-ion concentration in both solvents in the range between 2 x 10 -2 and 2 x 10 -5 M. The acidity determinations involve standardization and storage of the glass electrode in solutions in HzO and subsequent drying of the glass electrode with mercury before immersing it in the 0.5-ml...... the point of view of extrapolating rate data obtained in HzO-DzO mixtures to pure D2O....

  10. Natural 15N abundance of soil N pools and N2O reflect the nitrogen dynamics of forest soils

    Pörtl, K.; Zechmeister-Boltenstern, S.; Wanek, W.


    Natural N-15 abundance measurements of ecosystem nitrogen (N) pools and N-15 pool dilution assays of gross N transformation rates were applied to investigate the potential of delta N-15 signatures of soil N pools to reflect the dynamics in the forest soil N cycle. Intact soil cores were collected...... from pure spruce (Picea abies (L.) Karst.) and mixed spruce-beech (Fagus sylvatica L.) stands on stagnic gleysol in Austria. Soil delta N-15 values of both forest sites increased with depth to 50 cm, but then decreased below this zone. delta N-15 values of microbial biomass (mixed stand: 4.7 +/- 0...... represented the main N2O-producing process in the mixed forest stand as we detected a significant N-15 enrichment of its substrate NO3- (3.6 +/- 4.5 parts per thousand) compared to NH4+ (-4.6 +/- 2.6 parts per thousand) and its product N2O (-11.8 +/- 3.2 parts per thousand). In a N-15-labelling experiment...

  11. Glycoside Hydrolase (GH) 45 and 5 Candidate Cellulases in Aphelenchoides besseyi Isolated from Bird’s-Nest Fern

    Tsay, Tung-Tsuan; Tsai, Isheng J.; Chen, Peichen J.


    Five Aphelenchoides besseyi isolates collected from bird’s-nest ferns or rice possess different parasitic capacities in bird’s-nest fern. Two different glycoside hydrolase (GH) 45 genes were identified in the fern isolates, and only one was found in the rice isolates. A Abe GH5-1 gene containing an SCP-like family domain was found only in the fern isolates. Abe GH5-1 gene has five introns suggesting a eukaryotic origin. A maximum likelihood phylogeny revealed that Abe GH5-1 is part of the nematode monophyletic group that can be clearly distinguished from those of other eukaryotic and bacterial GH5 sequences with high bootstrap support values. The fern A. besseyi isolates were the first parasitic plant nematode found to possess both GH5 and GH45 genes. Surveying the genome of the five A. besseyi isolates by Southern blotting using an 834 bp probe targeting the GH5 domain suggests the presence of at least two copies in the fern-origin isolates but none in the rice-origin isolates. The in situ hybridization shows that the Abe GH5-1 gene is expressed in the nematode ovary and testis. Our study provides insights into the diversity of GH in isolates of plant parasitic nematodes of different host origins. PMID:27391812

  12. Evaluasi Keragaman Genetik Gen Hormon Pertumbuhan (GH pada Sapi Pesisir Sumatera Barat Menggunakan Penciri PCR-RFLP



    Full Text Available A total of 134 Pesisir cattle were genotyped for growth hormone (GH gene by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP. The genotype and allele frequencies of the GH MspI and GH AluI Pesisir cattle were determined. The GH MspI gene frequencies for the C and T allele were 0.209 and 0.791 respectively, while GH AluI gene frequencies for the L and V allele were 0.992 and 0.008 respectively. The chi-square analysis indicated that this population is not in Hardy-Weinberg Equilibrium status. Expected heterozygosis value (He for GH MspI and GH AluI were 0.3306±0.0266 and 0.0149±0.0073 respectively. The PCR-RFLP GH MspI marker has higher genetic variability compare to PCR-RFLP AluI marker. This finding showed that GH MspI T allele was favorable as a GH marker for Bos indicus breeds.

  13. Nonpolar nitrous oxide dimer: fundamentals of the mixed 14N2O-15N2O dimer and new combination bands of (14N2O)2 and (15N2O)2 involving the Bu, intermolecular bend.

    Dehghany, M; Afshari, Mahin; Abusara, Z; Moazzen-Ahmadi, N


    Spectra of the nonpolar nitrous oxide dimer in the region of the N2O v1 fundamental band are observed in a pulsed supersonic slit jet expansion probed with a tunable diode laser. Four bands are analysed: two fundamentals of the mixed 14N2O-15N2O dimer and combination bands involving the intermolecular disrotation of the monomers (Bu intermolecular bend) for both (14N2O)2 and (15N2O)2. Because the determination of this intermolecular frequency relies on the experimentally unknown frequency of the (forbidden) symmetric fundamental, we used previously published ab initio results and their proximity to our experimental values to assign the upper state of the combination bands. The resulting intermolecular disrotation frequencies are 42.3(1.0) and 41.6(1.0) cm(-1) for the (14N2O)2 and (15N2O)2, respectively. This represents the first observation of the mixed 14N2O-15N2O dimer, and the direct determination of a second intermolecular frequency for the nonpolar (N2O)2.

  14. Effects of a 7-day continuous infusion of octreotide on circulating levels of growth factors and binding proteins in growth hormone (GH)-treated GH-deficient patients

    Laursen, Torben; Møller, Jens; Fisker, Sanne


    Abstract In patients with acromegaly, clinical improvement has been reported after octreotide (OCT) treatment, even in cases of only a moderate suppression of growth hormone (GH) levels. In rats, OCT suppresses IGF-I mRNA expression and generation of serum and tissue IGF-I levels. A direct effect...

  15. Effects of a 7-day continuous infusion of octreotide on circulating levels of growth factors and binding proteins in growth hormone (GH)-treated GH-deficient patients

    Laursen, Torben; Møller, Jens; Fisker, Sanne;


    Abstract In patients with acromegaly, clinical improvement has been reported after octreotide (OCT) treatment, even in cases of only a moderate suppression of growth hormone (GH) levels. In rats, OCT suppresses IGF-I mRNA expression and generation of serum and tissue IGF-I levels. A direct effect...

  16. The effect of 30 months of low-dose replacement therapy with recombinant human growth hormone (rhGH) on insulin and C-peptide kinetics, insulin secretion, insulin sensitivity, glucose effectiveness, and body composition in GH-deficient adults

    Rosenfalck, A M; Maghsoudi, S; Fisker, S;


    (frequently sampled iv glucose tolerance test) glucose tolerance test, and body composition was estimated by dual-energy x-ray absorptiometry. Treatment with rhGH induced persistent favorable changes in body composition, with a 10% increase in lean body mass (P ...The aim of the present study was to evaluate the long-term (30 months) metabolic effects of recombinant human GH (rhGH) given in a mean dose of 6.7 microg/kg x day (= 1.6 IU/day), in 11 patients with adult GH deficiency. Glucose metabolism was evaluated by an oral glucose tolerance test and an iv...... in glucose tolerance, beta-cell response was still inappropriate. Our conclusion is that long-term rhGH-replacement therapy in GH deficiency adults induced a significant deterioration in glucose tolerance, profound changes in kinetics of C-peptide, and insulin and prehepatic insulin secretion, despite...

  17. Reactions of fac-[Re(CO)3(H2O)3]+ with nucleoside diphosphates and thiamine diphosphate in aqueous solution investigated by multinuclear NMR spectroscopy.

    Adams, Kristie M; Marzilli, Patricia A; Marzilli, Luigi G


    Products formed between monoester diphosphates (MDPs) and fac-[Re(CO)3(H2O)3]OTf at pH 3.6 were examined. Such adducts of the fac-[Re(CO)3]+ moiety have an uncommon combination of properties for an "inert" metal center in that sharp NMR signals can be observed, yet the products are equilibrating at rates allowing NMR EXSY cross-peaks to be observed. Thiamine diphosphate (TDP) and uridine 5'-diphosphate (5'-UDP) form 1:1 bidentate {Palpha,Pbeta} chelates, in which the MDP binds Re(I) via Palpha and Pbeta phosphate groups. Asymmetric centers are created at Re(I) (RRe/SRe) and Palpha (Delta/Lambda), leading to four diastereomers. The two mirror pairs of diastereomers (RReDelta/SReLambda) and (RReLambda/SReDelta) for TDP (no ribose) and for all four diastereomers (RReDelta, RReLambda, SReDelta, SReLambda) for 5'-UDP (asymmetric ribose) gave two and four sets of NMR signals for the bound MDP, respectively. 31Palpha-31Palpha EXSY cross-peaks indicate that the fac-[Re(CO)3(H2O)({Palpha,Pbeta}MDP)]- isomers interchange slowly on the NMR time scale, with an average k approximately equal to 0.8 s(-1) at 32 degrees C; the EXSY cross-peaks could arise from chirality changes at only Re(I) or at only Palpha. Guanosine 5'-diphosphate (5'-GDP), with a ribose moiety and a Re(I)-binding base, formed both possible diastereomers (RRe and SRe) of the fac-[Re(CO)3(H2O)({N7,Pbeta}GDP)]- macrochelate, with one slightly more abundant diastereomer suggested to be RRe by Mn2+ ion 1H NMR signal line-broadening combined with distances from molecular models. Interchange of the diastereomers requires that the coordination site of either N7 or Pbeta move to the H2O site. 31Palpha-31Palpha EXSY cross-peaks indicate a k approximately equal to 0.5 s(-1) at 32 degrees C for RRe-to-SRe interchange. The similarity of the rate constants for interchange of fac-[Re(CO)3(H2O)({Palpha,Pbeta}MDP)]- and fac-[Re(CO)3(H2O)({N7,Pbeta}GDP)]- adducts suggest strongly that interchange of Pbeta and H2O coordination

  18. Luminescence and energy transfer of Tb(3+)-doped BaO-Gd2O3-Al2O3-B2O3-SiO2 glasses.

    Zuo, Chenggang; Huang, Jinze; Liu, Shaoyou; Xiao, Anguo; Shen, Youming; Zhang, Xiangyang; Zhou, Zhihua; Zhu, Ligang


    Transparent Tb(3+)-doped BaO-Gd2O3-Al2O3-B2O3-SiO2 glasses with the greater than 4g/cm(3) were prepared by high temperature melting method and its luminescent properties have been investigated by measured UV-vis transmission, excitation, emission and luminescence decay spectra. The transmission spectrum shows there are three weak absorption bands locate at about 312, 378 and 484nm in the glasses and it has good transmittance in the visible spectrum region. Intense green emission can be observed under UV excitation. The effective energy transfer from Gd(3+) ion to Tb(3+) ion could occur and sensitize the luminescence of Tb(3+) ion. The green emission intensity of Tb(3+) ion could change with the increasing SiO2/B2O3 ratio in the borosilicate glass matrix. With the increasing concentration of Tb(3+) ion, (5)D4→(7)FJ transitions could be enhanced through the cross relaxation between the two nearby Tb(3+) ions. Luminescence decay time of 2.12ms from 546nm emission is obtained. The results indicate that Tb(3+)-doped BaO-Gd2O3-Al2O3-B2O3-SiO2 glasses would be potential scintillating material for applications in X-ray imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Non-linear Electrical Characteristics of ZnO Modified by Trioxides Sb2O3, Bi2O3, Fe2O3, Al2O3 and La2O3

    Mekap, Anita; Das, Piyush R.; Choudhary, R. N. P.


    The non-linear behavior of polycrystalline-ZnO-based voltage-dependent resistors is considered in the present study. A high-temperature solid-state reaction route was used to synthesize polycrystalline samples of ZnO modified by small amounts of the trioxides Sb2O3, Bi2O3, Fe2O3, etc. in various proportions. X-ray diffraction and scanning electron microscopy techniques were used to study the structural and microstructural characteristics of modified ZnO. Detailed studies of non-linear phenomena of the I-V characteristics, dielectric permittivity ( ɛ r), impedance ( Z), etc. of the samples have provided many interesting results. All the samples exhibited dielectric anomaly. Non-linear variation in polarization with electric field for all the samples was observed. Moreover, significant non-linearity in the I-V characteristics was observed in the breakdown region of all the samples at room temperature. The non-linear coefficient ( α) in different cases, i.e. for I- V, ɛ r- f, ɛ r- T, and ɛ r- Z, was calculated and found to be appreciable. The frequency dependence of ac conductivity suggests that the material obeys Jonscher's universal power law.

  20. Mechanical properties and histological evaluation of sintered beta-Ca2P2O7 with Na4P2O7.10H2O addition.

    Lin, F H; Lin, C C; Lu, C M; Liu, H C; Sun, J S; Wang, C Y


    The ultimate goal of implantation of biomaterials in the skeleton is to reach full integration of the non-living implant with the living bone. The biomaterial can be used much as a bone graft, resorbing or dissolving as bone growth occurs, and the end result is a new remoulded bone. Calcium pyrophosphate, Ca2P2O7, is one of the intermediate products of bone mineralization. beta-Dicalcium pyrophosphate (beta-DCP) doped with certain amounts of Na4P2O7.10H2O was prepared as the developed material. Na4P2O7.10H2O was used as a liquid-phase additive to improve the sintering process and promote physiological bioresorbability. Compressive strength and four-point bending strength were measured by the Bionix test system 858. The mechanical strength of the sintered beta-DCP increased with the addition of Na4P2O7.10H2O up to 5 wt%, but thereafter decreased. The microstructure and crystal structure were analysed by the techniques of SEM, EPMA, TEM and XRD. The relationship between the mechanical strength of the sintered bioceramics and the Na4P2O7.10H2O dopant was examined in terms of the presence of NaCa(PO3)3, grain growth and abnormal grain coalescence while the dopant increased. Preliminary in vivo evaluation was studied by rabbit femur condyle implantation. There was no inflammation or any toxic sign during the experimental period. The histological section of intraosseous implantation revealed that the new bone deposited directly on the surface of the material in the fourth week after operation. The implant gradually decreased in volume and was replaced by the surrounding regenerated bone in the rabbit condyle in vivo environment. The results led us to conclude that the developed material has great potential as a biodegradable bone substitute.