5,268 research outputs found
Human mesenchymal stem cells affect IgG production induced by lipopolysaccharide, cytomegalovirus and varicella zoster virus in human spleen cells
STM Imaging of Flux Line Arrangements in the Peak Effect Regime
We present the results of a study of vortex arrangements in the peak-effect
regime of 2H-NbSe_2 by scanning tunneling microscopy. By slowly increasing the
temperature in a constant magnetic field, we observed a sharp transition from
collective vortex motion to positional fluctuations of individual vortices at
the temperature which coincides with the onset of the peak effect in
ac-susceptibility. We conclude that the peak effect is a disorder driven
transition, with the pinning energy winning from the elastic energy.Comment: 4 pages, 4 figures included Manuscript has been submitte
Factory Gate Pricing: An Analysis of the Dutch Retail Distribution
Factory Gate Pricing (FGP) is a relatively new phenomenon in retail distribution. Under FGP, products are no longer delivered at the retailer distribution center, but collected by the retailer at the factory gates of the suppliers. Owing to both the asymmetry in the distribution networks (the supplier sites greatly outnumber the retailer distribution centers) and the better inventory and transport coordination mechanisms, this is likely to result in high savings. A mathematical model was used to analyze the benefits of FGP for a case study in the Dutch retail sector. Extensive numerical results are presented to show the effect of the orchestration shift from supplier to retailer, the improved coordination mechanisms, and sector-wide cooperation
Low Energy States of : Elements on the Doubly-Magic Nature of Ni
Excited levels were attributed to Ga for the first time
which were fed in the -decay of its mother nucleus Zn produced in
the fission of U using the ISOL technique. We show that the structure
of this nucleus is consistent with that of the less exotic proton-deficient
N=50 isotones within the assumption of strong proton Z=28 and neutron N=50
effective shell effects.Comment: 4 pages, REVTeX 4, 5 figures (eps format
Mesenchymal stromal cells enhance the engraftment of hematopoietic stem cells in an autologous mouse transplantation model
Mesenchymal Stromal Cells Engage Complement and Complement Receptor Bearing Innate Effector Cells to Modulate Immune Responses
Infusion of human third-party mesenchymal stromal cells (MSCs) appears to be a promising therapy for acute graft-versus-host disease (aGvHD). To date, little is known about how MSCs interact with the body's innate immune system after clinical infusion. This study shows, that exposure of MSCs to blood type ABO-matched human blood activates the complement system, which triggers complement-mediated lymphoid and myeloid effector cell activation in blood. We found deposition of complement component C3-derived fragments iC3b and C3dg on MSCs and fluid-phase generation of the chemotactic anaphylatoxins C3a and C5a. MSCs bound low amounts of immunoglobulins and lacked expression of complement regulatory proteins MCP (CD46) and DAF (CD55), but were protected from complement lysis via expression of protectin (CD59). Cell-surface-opsonization and anaphylatoxin-formation triggered complement receptor 3 (CD11b/CD18)-mediated effector cell activation in blood. The complement-activating properties of individual MSCs were furthermore correlated with their potency to inhibit PBMC-proliferation in vitro, and both effector cell activation and the immunosuppressive effect could be blocked either by using complement inhibitor Compstatin or by depletion of CD14/CD11b-high myeloid effector cells from mixed lymphocyte reactions. Our study demonstrates for the first time a major role of the complement system in governing the immunomodulatory activity of MSCs and elucidates how complement activation mediates the interaction with other immune cells
4mu spectra of AGB stars I: Observations
We present times series of high resolution spectra of AGB variables at 4mu.
Line profiles from the major contributors to the spectra of oxygen rich stars
at 4mu, OH, HO, HCl and SiO, are examined. The velocity as well as shape
variations of these profiles with time are discussed. The line profiles
investigated frequently have emission and multiple absorption components. The
changes with time of the 4mu region lines do not always follow the cyclic
variability seen in NIR spectra and in the photometric light curve. We
interpret and discuss the results qualitatively considering comparing the
spectral variability with that of the well behaved 1.6mu region and of
dynamical model atmospheres. Miras and semiregular variables are compared. The
origins of non-periodic behavior are discussed, including the role of spatial
inhomogeneities in the stellar atmosphere.Comment: 14 pages, 12 figures, accepted for publication in A&
Deformation change in light iridium nuclei from laser spectroscopy
Laser spectroscopy measurements have been performed on neutron-deficient and stable Ir isotopes using the COMPLIS experimental setup installed at ISOLDE-CERN. The radioactive Ir atoms were obtained from successive decays of a mass-separated Hg beam deposited onto a carbon substrate after deceleration to 1kV and subsequently laser desorbed. A three-color, two-step resonant scheme was used to selectively ionize the desorbed Ir atoms. The hyperfine structure (HFS) and isotope shift (IS) of the first transition of the ionization path 5d^{7}6s ^{2}^{4}F_{9/2} \to 5d^{7}6s6p ^{6}F_{11/2} at 351.5nm were measured for Ir, and the stable Ir. The nuclear magnetic moments μI and the spectroscopic quadrupole moments Qs were obtained from the HFS spectra and the change of the mean square charge radii from the IS measurements. The sign of μI was experimentally determined for the first time for the masses 182≤A≤189 and the isomeric state . The spectroscopic quadrupole moments of Ir and Ir were measured also for the first time. A large mean square charge radius change between Ir and and between and was observed corresponding to a sudden increase in deformation: from β2 ≃ + 0.16 for the heavier group A = 193, 191, 189, 187 and 186m to β2 ≥ + 0.2 for the lighter group A = 186g, 185, 184, 183 and 182. These results were analyzed in the framework of a microscopic treatment of an axial rotor plus one or two quasiparticle(s). This sudden deformation change is associated with a change in the proton state that describes the odd-nuclei ground state or that participates in the coupling with the neutron in the odd-odd nuclei. This state is identified with the π3/2+[402] orbital for the heavier group and with the π1/2-[541] orbital stemming from the 1h _9/2 spherical subshell for the lighter group. That last state seems to affect strongly the observed values of the nuclear moments
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