1,457 research outputs found
Transfer of Fas (CD95) protein from the cell surface to the surface of polystyrene beads coated with anti-Fas antibody clone CH-11
Mouse monoclonal anti-Fas (CD95) antibody clone CH-11 has been widely used in research on apoptosis. CH-11 has the ability to bind to Fas protein on cell surface and induce apoptosis. Here, we used polystyrene beads coated with CH-11 to investigate the role of lipid rafts in Fas-mediated apoptosis in SKW6.4 cells. Unexpectedly, by treatment of the cells with CH-11-coated beads Fas protein was detached from cell surface and transferred to the surface of CH-11-coated beads. Western blot analysis showed that Fas protein containing both extracellular and intracellular domains was attached to the beads. Fas protein was not transferred from the cells to the surface of the beads coated with other anti-Fas antibodies or Fas ligand. Similar phenomenon was observed in Jurkat T cells. Furthermore, CH-11-induced apoptosis was suppressed by pretreatment with CH-11-coated beads in Jurkat cells. These results suggest that CH-11 might possess distinct properties on Fas protein compared with other anti-Fas antibodies or Fas ligand, and also suggest that caution should be needed to use polystyrene beads coated with antibodies such as CH-11
The Intermediate r-process in Core-collapse Supernovae Driven by the Magneto-rotational Instability
We investigated r-process nucleosynthesis in magneto-rotational supernovae, based on a new explosion mechanism induced by the magneto-rotational instability (MRI). A series of axisymmetric magneto-hydrodynamical simulations with detailed microphysics including neutrino heating is performed, numerically resolving the MRI. Neutrino-heating dominated explosions, enhanced by magnetic fields, showed mildly neutronrich ejecta producing nuclei up to A similar to 130 (i. e., the weak r-process), while explosion models with stronger magnetic fields reproduce a solar-like r-process pattern. More commonly seen abundance patterns in our models are in between the weak and regular r-process, producing lighter and intermediate-mass nuclei. These intermediate r-processes exhibit a variety of abundance distributions, compatible with several abundance patterns in r-process-enhanced metal-poor stars. The amount of Eu ejecta similar to 10(-5) M circle dot in magnetically driven jets agrees with predicted values in the chemical evolution of early galaxies. In contrast, neutrino-heating dominated explosions have a significant amount of Fe (Ni-56) and Zn, comparable to regular supernovae and hypernovae, respectively. These results indicate magneto-rotational supernovae can produce a wide range of heavy nuclei from iron-group to r-process elements, depending on the explosion dynamics
Anisotropic magnetic field responses of ferroelectric polarization in a trigonal multiferroic CuFe1-xAlxO2 (x=0.015)
We have investigated magnetic field dependences of a ferroelectric
incommensurate-helimagnetic order in a trigonal magneto-electric (ME)
multiferroic CuFe1-xAlxO2 with x=0.015, which exhibits the ferroelectric phase
as a ground state, by means of neutron diffraction, magnetization and
dielectric polarization measurements under magnetic fields applied along
various directions. From the present results, we have established the H-T
magnetic phase diagrams for the three principal directions of magnetic fields;
(i) parallel to the c axis, (ii) parallel to the helical axis, and (iii)
perpendicular to the c and the helical axes. While the previous dielectric
polarization (P) measurements on CuFe1-xGaxO2 with x=0.035 have demonstrated
that the magnetic field dependence of the `magnetic domain structure' results
in distinct magnetic field responses of P [S. Seki et al., Phys. Rev. Lett.,
103 237601 (2009)], the present study have revealed that the anisotropic
magnetic field dependence of the ferroelectric helimagnetic order `in each
magnetic domain' can be also a source of a variety of magnetic field responses
of P in CuFe1-xAxO2 systems (A=Al, Ga).Comment: 11 pages, 9 figures, accepted for publication in Phys. Rev.
Bulk Fermi surface and momentum density in heavily doped LaSrCuO using high resolution Compton scattering and positron annihilation spectroscopies
We have observed the bulk Fermi surface (FS) in an overdoped (=0.3) single
crystal of LaSrCuO by using Compton scattering. A
two-dimensional (2D) momentum density reconstruction from measured Compton
profiles yields a clear FS signature in the third Brillouin zone along [100].
The quantitative agreement between density functional theory (DFT) calculations
and momentum density experiment suggests that Fermi-liquid physics is restored
in the overdoped regime. In particular the predicted FS topology is found to be
in good accord with the corresponding experimental data. We find similar
quantitative agreement between the measured 2D angular correlation of positron
annihilation radiation (2D-ACAR) spectra and the DFT based computations.
However, 2D-ACAR does not give such a clear signature of the FS in the extended
momentum space in either the theory or the experiment.Comment: 9 pages, 8 figure
High resolution Compton scattering as a Probe of the Fermi surface in the Iron-based superconductor
We have carried out first principles all-electron calculations of the
(001)-projected 2D electron momentum density and the directional Compton
profiles along the [100], [001] and [110] directions in the Fe-based
superconductor LaOFeAs within the framework of the local density approximation.
We identify Fermi surface features in the 2D electron momentum density and the
directional Compton profiles, and discuss issues related to the observation of
these features via Compton scattering experiments.Comment: 4 pages, 3 figure
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