Low temperature magnetic transitions of single crystal HoBi

We present resistivity, specific heat and magnetization measurements in high quality single crystals of HoBi, with a residual resistivity ratio of 126. We find, from the temperature and field dependence of the magnetization, an antiferromagnetic transition at 5.7 K, which evolves, under magnetic fields, into a series of up to five metamagnetic phases.Comment: 5 pages, 5 figure

Single Wall Carbon Nanotubes Filled with Metallocenes: a First Example of Non-Fullerene Peapods

We report the synthesis and analysis of metallocenes (ferrocene, chromocene, ruthenocene, vanadocene, tungstenocene-dihydride) encapsulated in single wall carbon nanotubes (SWNTs). In the case of ferrocene, efficient filling of the SWNTs was accomplished from both the liquid and the vapor phase. The other two metallocenes were filled from the vapor phase. High resolution transmission electron microscopy reveals single molecular chains of metallocenes inside SWNTs. Molecules move under the electron beam in the SWNTs indicating the absence of strong chemical bonds between each other and the SWNT wall. Their movement freezes after short illumination as a result of irradiation damage. Energy dispersive X-ray spectrometry confirms the presence of iron, chromium, ruthenium, vanadium and tungsten

The Plasma Structure of the Cygnus Loop from the Northeastern Rim to the Southwestern Rim

The Cygnus Loop was observed from the northeast to the southwest with XMM-Newton. We divided the observed region into two parts, the north path and the south path, and studied the X-ray spectra along two paths. The spectra can be well fitted either by a one-component non-equilibrium ionization (NEI) model or by a two-component NEI model. The rim regions can be well fitted by a one-component model with relatively low \kTe whose metal abundances are sub-solar (0.1--0.2). The major part of the paths requires a two-component model. Due to projection effects, we concluded that the low kTe (about 0.2 keV) component surrounds the high kTe (about 0.6 keV) component, with the latter having relatively high metal abundances (about 5 times solar). Since the Cygnus Loop is thought to originate in a cavity explosion, the low-kTe component originates from the cavity wall while the high-kTe component originates from the ejecta. The flux of the cavity wall component shows a large variation along our path. We found it to be very thin in the south-west region, suggesting a blowout along our line of sight. The metal distribution inside the ejecta shows non-uniformity, depending on the element. O, Ne and Mg are relatively more abundant in the outer region while Si, S and Fe are concentrated in the inner region, with all metals showing strong asymmetry. This observational evidence implies an asymmetric explosion of the progenitor star. The abundance of the ejecta also indicates the progenitor star to be about 15 M_sun.Comment: 24 pages, 9 figures, Astrophysical Journal in pres

Symmetrical interfacial reconstruction and magnetism in La_(0.7)Ca_(0.3)MnO_(3)/YBa_(2)Cu_(3)O_(7)/La_(0.7)Ca_(0.3)MnO_(3) heterostructures

We have analyzed the interface structure and composition of La_(0.7)Ca_(0.3)MnO_(3)/YBa_(2)Cu_(3)O_(7)/La_(0.7)Ca_(0.3)MnO_(3) trilayers by combined polarized neutron reflectometry, aberration-corrected microscopy, and atomic column resolution electron-energy-loss spectroscopy and x ray absorption with polarization analysis. We find the same stacking sequence at both top and bottom cuprate interfaces. X-ray magnetic circular dichroism experiments show that both cuprate interfaces are magnetic with a magnetic moment induced in Cu atoms as expected from symmetric Mn-O-Cu superexchange paths. These results supply a solid footing for the applicability of recent theories explaining the interplay between magnetism and superconductivity in this system in terms of the induced Cu spin polarization at both interfaces

Generation of Mucopolysaccharidosis type II (MPS II) human induced pluripotent stem cell (iPSC) line from a 3-year-old male with pathogenic IDS mutation

AbstractPeripheral blood was collected from a 3-year-old male patient with an X-linked recessive mutation of Iduronate 2-sulfatase (IDS) gene (NM_000202.7(IDS):c.85C>T) causing MPS II (OMIM 309900). Peripheral blood mononuclear cells (PBMCs) were reprogrammed by lentiviral delivery of a self-silencing hOKSM polycistronic vector. The pluripotency of the iPSC line was confirmed by the expression of pluripotency-associated markers and in vitro spontaneous differentiation towards the 3 germ layers. The iPSC line showed normal karyotype. The cell line offers a good platform to study MPS II pathophysiology, for drug testing, early biomarker discovery and gene therapy studies

Thickness dependent magnetic anisotropy of ultrathin LCMO epitaxial thin films

The magnetic properties of La0.7Ca0.3MnO3 (LCMO) manganite thin films were studied with magnetometry and ferromagnetic resonance as a function of film thickness. They maintain the colossal magnetoresistance behavior with a pronounced metal-insulator transition around 150-200 K, except for the very thinnest films studied (3 nm). Nevertheless, LCMO films as thin as 3 nm remain ferromagnetic, without a decrease in saturation magnetization, indicating an absence of dead-layers, although below approx. 6 nm the films remain insulating at low temperature. Magnetization hysteresis loops reveal that the magnetic easy axes lie in the plane of the film for thicknesses in the range of 4-15 nm. Ferromagnetic resonance studies confirm that the easy axes are in-plane, and find a biaxial symmetry in-plane with two, perpendicular easy axes. The directions of the easy axes with respect to the crystallographic directions of the cubic SrTiO3 substrate differ by 45 degrees in 4 nm and 15 nm thick LCMO films.Comment: Presented at Intermag conference (Madrid, 2008). Accepted for publication in IEEE Transactions on Magnetic

Charge transfer and Fermi level shift in p-doped single-walled carbon nanotubes

The electronic properties of p-doped single-walled carbon nanotube (SWNT) bulk samples were studied by temperature-dependent resistivity and thermopower, optical reflectivity and Raman spectroscopy. These all give consistent results for the Fermi level downshift (δ EF) induced by doping. We find δ EF ≈ 0.35 eV and 0.50 eV for concentrated nitric and sulfuric acid doping respectively. With these values, the evolution of Raman spectra can be explained by variations in the resonance condition as EF moves down into the valence band. Furthermore, we find no evidence for diameter-selective doping, nor any distinction between doping responses of metallic and semiconducting tubes

Applicability of antibody and mRNA expression microarrays for identifying diagnostic and progression markers of early and late stage colorectal cancer

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Hemorheological and metabolic consequences of renal ischemia-reperfusion and their modulation by N,N-dimethyltryptamine on a rat model

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