Electron-spin-resonance And Lattice-parameter Study Of Cerium Cubic Laves-phase Compounds: Evidence For Intermediate-valence State

A lattice-constant study of the cubic C 15 Ce(IrxOs1-x)2 and Ce(PtxIr1-x)2 mixtures at room temperature reveals anomalous lattice constant versus x behavior. Also the electron-spin-resonance thermal broadening and g shift of Nd3+ in these compounds are anomalous but could be correlated with the lattice parameters. This is taken as evidence for intermediate-valence state in some of the mixtures. © 1980 The American Physical Society.45241966197

Mapping contacts between regulatory domains of skeletal muscle TnC and Tnl by analyses of a single-chain chimeras.

The troponin (Tn) complex is formed by TnC, TnI and TnT and is responsible for the calcium-dependent inhibition of muscle contraction. TnC and TnI interact in an antiparallel fashion in which the N domain of TnC binds in a calcium-dependent manner to the C domain of TnI, releasing the inhibitory effect of the latter on the actomyosin interaction. While the crystal structure of the core cardiac muscle troponin complex has been determined, very little high resolution information is available regarding the skeletal muscle TnITnC complex. With the aim of obtaining structural information regarding specific contacts between skeletal muscle TnC and TnI regulatory domains, we have constructed two recombinant chimeric proteins composed of the residues 191 of TnC linked to residues 98182 or 98147 of TnI. The polypeptides were capable of binding to the thin filament in a calcium-dependent manner and to regulate the ATPase reaction of actomyosin. Small angle X-ray scattering results showed that these chimeras fold into compact structures in which the inhibitory plus the C domain of TnI, with the exception of residues 148182, were in close contact with the N-terminal domain of TnC. CD and fluorescence analysis were consistent with the view that the last residues of TnI (148182) are not well folded in the complex. MS analysis of fragments produced by limited trypsinolysis showed that the whole TnC N domain was resistant to proteolysis, both in the presence and in the absence of calcium. On the other hand the TnI inhibitory and C-terminal domains were completely digested by trypsin in the absence of calcium while the addition of calcium results in the protection of only residues 114137

Effects of phase separation on the magnetization, x-ray diffraction, and Raman scattering of (La1-yNdy)(1-x)CaxMnO3 (y=0,0.5,1.0; x=1/3)

Dc-magnetization, x-ray diffraction, and Raman-scattering studies in polycrystalline (La1-yNdy)(t-x)CaxMnO3 (y = 0.0,0.5,1.0, and x = 1/3) samples are presented. The samples with y = 0.5 and 1.0 show complex magnetic states at low temperatures, with a ferromagnetic coupling strength that weal;ens with increasing y. X-ray measurements show a single crystallographic phase at all temperatures for y = 0.5, with lattice parameter anomalies at temperatures related to electronic and magnetic transitions. The presence of high-frequency vibrational modes in Raman-scattering measurements indicates the existence of charge- and orbital-ordered domains for y=0.5 and 1.0, which are closely related to the antiferromagnetic component identified by the magnetization experiments. The close relationship between results obtained by magnetic, structural, and optical probes is discussed.63

Effects Of Phase Separation On The Magnetization, X-ray Diffraction, And Raman Scattering Of (la1-yndy) 1-xcaxmno3 (y = 0,0.5,1.0;x = 1/3)

Dc-magnetization, x-ray diffraction, and Raman-scattering studies in polycrystalline (La1-yNdy)1-xCaxMnO3 (y = 0.0,0.5,1.0, and x = 1/3) samples are presented. The samples with y = 0.5 and 1.0 show complex magnetic states at low temperatures, with a ferromagnetic coupling strength that weakens with increasing y. X-ray measurements show a single crystallographic phase at all temperatures for y=0.5, with lattice parameter anomalies at temperatures related to electronic and magnetic transitions. The presence of high-frequency vibrational modes in Raman-scattering measurements indicates the existence of charge- and orbital-ordered domains for y = 0.5 and 1.0, which are closely related to the antiferromagnetic component identified by the magnetization experiments. The close relationship between results obtained by magnetic, structural, and optical probes is discussed.636644041644046Wollan, E.O., Koehler, W.C., (1955) Phys. Rev., 100, p. 545Goodenough, J.B., (1955) Phys. Rev., 100, p. 564Chen, C.H., Cheong, S.-W., (1996) Phys. Rev. Lett., 76, p. 4042Radaelli, P.G., Cox, D.E., Marezio, M., Cheong, S.-W., Schiffer, P.E., Ramirez, A.P., (1995) Phys. Rev. Lett., 75, p. 4488Hwang, H.Y., Cheong, S.-W., Radaelli, P.G., Marezio, M., Batlogg, B., (1995) Phys. Rev. Lett., 75, p. 914Coey, J.M.D., Viret, M., Ranno, L., Ounadjela, K., (1995) Phys. Rev. Lett., 75, p. 3910Uehara, M., Mori, S., Chen, C.H., Cheong, S.-W., (1999) Nature (London), 399, p. 560Moreo, A., Yunoke, S., Dagotto, E., (1999) Science, 283, p. 2034. , and references thereinArchibald, W., Zhou, J.-S., Goodenough, J.B., (1996) Phys. Rev. B, 53, p. 14445Zhou, J.-S., Archibald, W., Goodenough, J.B., (1996) Nature (London), 381, p. 770Rao, G.H., Sun, J.R., Liang, J.K., Zhou, W.Y., Cheng, X.R., (1996) Appl. Phys. Lett., 69, p. 424Rao, G.H., Sun, J.R., Liang, J.K., Zhou, W.Y., (1997) Phys. Rev. B, 55, p. 3742Zhou, J.-S., Goodenough, J.B., (1998) Phys. Rev. Lett., 80, p. 2665Ibarra, M.R., Zhao, G.-M., De Teresa, J.M., García-Landa, B., Arnold, Z., Marquina, C., Algarabel, P.A., Ritter, C., (1998) Phys. Rev. B, 57, p. 7446Baszynski, J., Kovac, J., Kowalczyk, A., (1999) J. Magn. Magn. Mater., 195, p. 93Moritomo, Y., (1999) Phys. Rev. B, 60, p. 10374Young, R.A., Sakthivel, A., Moss, T.S., Paiva-Santos, C.O., (1995) J. Appl. Crystallogr., 28, p. 366Radaelli, P.G., Cox, D.E., Marezio, M., Cheong, S.-W., (1997) Phys. Rev. B, 55, p. 3015Huang, Q., Santoro, A., Lynn, J.W., Erwin, R.W., Borches, J.A., Peng, J.L., Ghosh, K., Greene, R.L., (1998) Phys. Rev. B, 58, p. 2684Irwin, J.C., Chrzanowski, J., Franck, J.P., (1999) Phys. Rev. B, 59, p. 9362Abrashev, M.V., Ivanov, V.G., Iliev, M.N., Chakalov, R.A., Chakalova, R.I., Thomsen, C., (1999) Phys. Status Solidi B, 215, p. 631Liarokapis, E., Leventouri, Th., Lampakis, D., Palles, D., Neumeier, J.J., Goodwin, D.H., (1999) Phys. Rev. B, 60, p. 12758Granado, E., Moreno, N.O., García, A., Sanjurjo, J.A., Rettori, C., Torriani, I., Oseroff, S.B., Tokura, Y., (1998) Phys. Rev. B, 58, p. 11435Yoon, S., Liu, H.L., Schollerer, G., Cooper, S.L., Han, P.D., Payne, D.A., Cheong, S.-W., Fisk, Z., (1998) Phys. Rev. B, 58, p. 2795Liu, H.L., Yoon, S., Cooper, S.L., Cheong, S.-W., Han, P.D., Payne, D.A., (1998) Phys. Rev. B, 58, pp. R10115Liu, K., Wu, X.W., Ahn, K.H., Sulchek, T., Chien, C.L., Xiao, J.Q., (1996) Phys. Rev. B, 54, p. 3007Granado, E., Pagliuso, P.G., Sanjurjo, J.A., Rettori, C., Oseroff, S.B., Causa, M.T., Butera, A., Schultz, S., (1998) Non-Crystalline and Nanoscale Materials, pp. 105-115. , edited by J. Rivas and M.A. López-Quintela (World Scientific, Singapore)Granado, E., Sanjurjo, J.A., Rettori, C., Prado, F., Sánchez, R.D., Caneiro, A., Oseroff, S.B., (2000) Phys. Status Solidi B, 220, p. 609Dediu, V., Ferdeghini, C., Matacotta, F.C., Nozar, P., Ruani, G., (2000) Phys. Rev. Lett., 84, p. 4489Adams, C.P., Lynn, J.W., Mukovskii, Y.M., Arsenov, A.A., Shulyatev, D.A., (2000) Phys. Rev. Lett., 85, p. 3954Dai, P., Fernandez-Baca, J.A., Wakabayashi, N., Plummer, E.W., Tomioka, Y., Tokura, Y., (2000) Phys. Rev. Lett., 85, p. 255

Role Of Oxygen Vacancies In The Magnetic And Dielectric Properties Of The High-dielectric-constant System Cacu3 Ti4 O12: An Electron-spin Resonance Study

We report experiments of electron spin resonance (ESR) of Cu2+ in polycrystalline samples of CaCu3 Ti4 O12 post-annealed in different atmospheres. After being synthesized by solid state reaction, pellets of CaCu3 Ti4 O12 were annealed for 24 h at 1000°C under air, Ar or O2. Our temperature dependent ESR data revealed for all samples nearly temperature independent g value (2.15(1)) and linewidth for T TN ≈25 K. However, the values of ESR linewidth are strongly affected by the oxygen content in the sample. For instance, argon post-annealed samples show a much larger linewidth than the O2 or air post-annealed samples. We attribute this broadening to an increase of the dipolar homogeneous broadening of the Cu2+ ESR lines due to the presence of oxygen vacancies which induce an S=1 2 spin inside the TiO6 octahedra. Correlation between a systematic dependence of the ESR linewidth on the oxygen content and the high dielectric constant of these materials is addressed. Also, ESR, magnetic susceptibility, and specific heat data for a single crystal of CaCu3 Ti4 O12 and for polycrystals of CdCu3 Ti4 O12 are reported. © 2006 The American Physical Society.7322Subramanian, M.A., Li, D., Duan, N., Reisner, B., Sleight, A.W., (2000) J. Solid State Chem., 151, p. 323. , JSSCBI 0022-4596 10.1006/jssc.2000.8703Ramirez, A.P., Subramanian, M.A., Gardel, M., Blumberg, G., Li, D., Vogt, T., Shapiro, S.M., (2000) Solid State Commun., 151, p. 217. , SSCOA4 0038-1098Homes, C.C., Vogt, T., Shapiro, S.M., Wakimoto, S., Ramirez, A.P., (2001) Science, 293, p. 673. , SCIEAS 0036-8075 10.1126/science.292.5517.673Lunkenheimer, P., Bobnar, V., Pronin, A.V., Ritus, A.I., Volkov, A.A., Loidl, A., (2002) Phys. Rev. B, 66, p. 052105. , PRBMDO 0163-1829 10.1103/PhysRevB.66.052105Homes, C.C., Vogt, T., Shapiro, S.M., Wakimoto, S., Subramanian, M.A., Ramirez, A.P., (2003) Phys. Rev. B, 67, p. 092106. , PRBMDO 0163-1829 10.1103/PhysRevB.67.092106Sinclair, D.C., Admas, T.B., Morrison, F.D., West, A.R., (2002) Appl. Phys. Lett., 80, p. 2153. , APPLAB 0003-6951 10.1063/1.1463211Giulloto, E., Mozzati, M.C., Azzoni, C.B., Massarotti, V., Bini, M., (2004) Ferroelectrics, 298, p. 61. , FEROA8 0015-0193Mozzati, M.C., Azzoni, C.B., Capsoni, D., Bini, M., Massarotti, V., (2003) J. Phys.: Condens. Matter, 15, p. 7365. , JCOMEL 0953-8984 10.1088/0953-8984/15/43/018Subramanian, M.A., Sleight, A.W., (2002) Solid State Sci., 4, p. 347. , SSSCFJ 1293-2558 10.1016/S1293-2558(01)01262-6Fang, L., Shen, M., Cao, W., (2004) J. Appl. Phys., 95, p. 6483. , JAPIAU 0021-8979 10.1063/1.1728308Koitzsch, A., Blumberg, G., Gozar, A., Dennis, B., Ramirez, A.P., Trebst, S., Wakimoto, S., (2002) Phys. Rev. B, 65, p. 052406. , PRBMDO 0163-1829 10.1103/PhysRevB.65.052406Bosman, A.J., Van Daal, H.J., (1970) Adv. Phys., 19, p. 1. , ADPHAH 0001-8732 10.1080/00018737000101071Lenjer, S., Schirmer, O.F., Hesse, H., Kool, T.W., (2002) Phys. Rev. B, 66, p. 165106. , PRBMDO 0163-1829 10.1103/PhysRevB.66.165106Bednorz, J.G., Mller, K.A., (1988) Rev. Mod. Phys., 60, p. 585. , RMPHAT 0034-6861 10.1103/RevModPhys.60.585Salamon, M.B., Jaime, M., (2001) Rev. Mod. Phys., 73, p. 583. , RMPHAT 0034-6861 10.1103/RevModPhys.73.583Scharfschwerdt, R., Mazur, A., Schirmer, O.F., Hesse, H., Mendricks, S., (1996) Phys. Rev. B, 54, p. 15284. , PRBMDO 0163-1829 10.1103/PhysRevB.54.15284Laguta, V.V., Slipenyuk, A.M., Bykov, I.P., Glinchuck, M.D., Maglione, M., Michau, D., Rosa, J., Jastrabik, L., (2005) Appl. Phys. Lett., 87, p. 022903. , APPLAB 0003-6951 10.1063/1.1954900Cohn, J.L., Peterca, M., Neumeier, J.J., (2005) J. Appl. Phys., 97, p. 034102. , JAPIAU 0021-8979 10.1063/1.1834976Abragam, A., Bleaney, B., (1670) Electron Paramagnetic Resonance of Transition Ions, , Clarendon, OxfordPoole, C.P., Farach, H.A., (1971) Relaxation in Magnetic Resonance, , Academic, New YorkVan Vleck, J.H., (1948) Phys. Rev., 74, p. 1168. , PHRVAO 0031-899X 10.1103/PhysRev.74.1168Anderson, P.W., Weiss, P.R., (1953) Rev. Mod. Phys., 25, p. 269. , RMPHAT 0034-6861 10.1103/RevModPhys.25.269Wu, L., Zhu, Y., Park, S., Shapiro, S., Shirane, G., Tafto, J., (1953) Rev. Mod. Phys., 25, p. 269. , RMPHAT 0034-6861 10.1103/RevModPhys.25.26

The complex microbial community of withered berries of cv. Corvina as revealed by metagenomic analysis

Corvina is the most important of Verona\u2019s red grape varieties and forms the basis for the production of unique wines, such as Amarone and Recioto of the Valpolicella area (Italy). The distinctive features of such wines are linked to the peculiar winemaking techniques and especially to the post-harvest grape withering process, when the grapes are partially dried in attics for three/four months to concentrate sugars up to about 27% (w/v). Dehydratation increases the concentration of constituent substances in berries, determining also specific expression of grape genes. During this process, grapes are colonized with a complex microbiota to an extent which depends on environmental temperature and humidity. In this study, a whole metagenome sequencing (WMS) approach was used to analyse the microbial consortia present on Corvina berries at the end of the withering process performed in two different conditions (\u201ctraditional\u201d or \u201cfast\u201d). Representative berry samples were collected and washed to avoid grapevine DNA contamination. Bioinformatic analyses, performed on reads and scaffolds, revealed that traditionally withered berries were dominated by Clostridiales and Pseudomonadales, while the fast procedure determined the presence of Enterobacteriales and Lactobacillales. On the contrary, few consistent differences characterized the eukaryotic fraction, dominated by Aspergillus and Penicillium for both samples. Interestingly, the \u201cbinning\u201d procedure revealed 15 most abundant genomes characterizing the two conditions. These results provide insights into the microbial community of Corvina withered berries and reveal relevant variations attributable to environmental withering conditions. Further studies will be performed to determine whether the different microbial compositions could lead to significant chemical variations of the musts, with an impact on the organoleptic properties of wine. This study underlines how novel technologies, like WMS, could open novel perspectives in the knowledge and management of traditional processes as the withering process of Corvina, with an impact on the winemaking of important Italian wines

Raman-scattering and weak-ferromagnetism studies in Eu2CuO4

We show that there is a subtle instability of the T' structure for the R(2)CuO(4) (R = rare earth) compounds at the center of the R series with the boundary at Eu2CuO4. Crystals grown in Pt crucibles and PbQ flux show weak ferromagnetism (WF) and two strongly temperature-dependent forbidden Raman peaks. However crystals grown in alumina crucibles and CuO flux do not show WF and the forbidden Raman peaks are much less intense. The observation of WF and forbidden Raman peaks for Eu2CuO4 compounds suggests that the instability of the T' structure may be associated with O(1) displacement in the CuO2 planes.53283784

Crystal Structure And Physical Properties Of Gd3co 4sn13 Intermetallic Antiferromagnet

We have synthesized single crystalline samples of Gd3 Co4 Sn13 intermetallic compound using a Sn-flux method. This compound crystallizes with a cubic Yb3 Co4 Sn13 -type structure, space group Pm-3n, which has 40 atoms per unit cell. Measurements of the magnetic susceptibility, heat capacity, electrical resistivity, and electron spin resonance (ESR) revealed that Gd3 Co4 Sn13 is a metallic Curie-Weiss paramagnet at high temperature and presents an antiferromagnetic ordering below TN =14.5 K. In the paramagnetic state, a single Gd3+ ESR line with a nearly temperature independent g∼2.005 (2) is observed, and its linewidth follows a Korringa-like behavior as a function of temperature. From the Korringa rate (ΔHΔT∼4 OeK) and g -shift (Δg∼0.012) obtained from the ESR experiments combined with the magnetic susceptibility and specific heat data for Gd3 Co4 Sn13, we have extracted the exchange parameters between the Gd3+ local moments and the conduction-electrons (c-e) in this compound. This exchange parameter Jfs ≈10 meV was found to be c-e wave-vector independent and the electronic structure of Gd3 Co4 Sn13 has a single band character. © 2006 American Institute of Physics.998Remeika, J.P., (1980) Solid State Commun., 34, p. 923Remeika, J.P., (1982) Solid State Commun., 42, p. 97Sato, H., (1993) Physica B, 188, p. 630Hundley, M.F., (2002) Phys. Rev. B, 65, p. 024401Israel, C., (2005) Physica B, 359-361, p. 251Cornelius, A., Physica BPagliuso, P.G., (2001) Phys. Rev. B, 63, p. 054426Granado, E., (2004) Phys. Rev. B, 69, p. 144411Davidov, D., Maki, K., Orbach, R., Rettori, C., Chock, E.P., (1973) Solid State Commun., 12, p. 621Feher, G., Kip, A.F., (1955) Phys. Rev., 98, p. 337. , 0031-899X 10.1103/PhysRev.98.337Dyson, F.J., (1955) Phys. Rev., 98, p. 349Yosida, K., (1957) Phys. Rev., 106, p. 893Korringa, J., (1950) Physica (Amsterdam), 16, p. 601Rettori, C., Kim, H.M., Chock, E.P., Davidov, D., (1974) Phys. Rev. B, 10, p. 1826Abragam, A., Bleaney, B., (1970) EPR of Transition Ions, , Clarendon, OxfordMoriya, T., (1963) J. Phys. Soc. Jpn., 18, p. 516Narath, A., (1967) Phys. Rev., 163, p. 232Pagliuso, P.G., (1999) Phys. Rev. B, 60, p. 13515Bittar, E.M.

Inflammatory and Coagulation Biomarkers and Mortality in Patients with HIV Infection

Analyzing biomarker data from participants in a previous randomized controlled trial of continuous versus interrupted HIV treatment (the SMART trial), James Neaton and colleagues find that mortality was related to IL-6 and fibrin D-dimers