Differential localization and expression of complement in a rat model of motor neuron disease

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The structure of epitaxial V2O3 films and their surfaces : a medium energy ion scattering study

Medium energy ion scattering, using 100 keV H+ incident ions, has been used to investigate the growth of epitaxial films, up to thicknesses of ~200 Å, of V2O3 on both Pd(111) and Au(111). Scattered-ion energy spectra provide a measure of the average film thickness and the variations in this thickness, and show that, with suitable annealing, the crystalline quality is good. Plots of the scattering yield as a function of scattering angle, so-called blocking curves, have been measured for two different incidence directions and have been used to determine the surface structure. Specifically, scattering simulations for a range of different model structures show poor agreement with experiment for half-metal (….V’O3V) and vanadyl (….V’O3V=O) terminations, with and without surface interlayer relaxations. However, good agreement with experiment is found for the modified oxygen-termination structure, first proposed by Kresse et al., in which a subsurface V half-metal layer is moved up into the outermost V buckled metal layer to produce a VO2 overlayer on the underlying V2O3, with an associated layer structure of ….O3VV’’V’O3

Shallow BF2 implants in Xe-bombardment-preamorphized Si: the interaction between Xe and F

Si(100) samples, preamorphized to a depth of ~30 nm using 20 keV Xe ions to a nominal fluence of 2×1014 cm-2 were implanted with 1 and 3 keV BF2 ions to fluences of 7×1014 cm-2. Following annealing over a range of temperatures (from 600 to 1130 °C) and times the implant redistribution was investigated using medium-energy ion scattering (MEIS), secondary ion mass spectrometry (SIMS), and energy filtered transmission electron microscopy (EFTEM). MEIS studies showed that for all annealing conditions leading to solid phase epitaxial regrowth, approximately half of the Xe had accumulated at depths of 7 nm for the 1 keV and at 13 nm for the 3 keV BF2 implant. These depths correspond to the end of range of the B and F within the amorphous Si. SIMS showed that in the preamorphized samples, approximately 10% of the F migrates into the bulk and is trapped at the same depths in a ~1:1 ratio to Xe. These observations indicate an interaction between the Xe and F implants and a damage structure that becomes a trapping site. A small fraction of the implanted B is also trapped at this depth. EXTEM micrographs suggest the development of Xe agglomerates at the depths determined by MEIS. The effect is interpreted in terms of the formation of a volume defect structure within the amorphized Si, leading to F stabilized Xe agglomerates or XeF precipitates

Synapse-Associated Expression of an Acetylcholine Receptor-Inducing Protein, ARIA/Heregulin, and Its Putative Receptors, ErbB2 and ErbB3, in Developing Mammalian Muscle

AbstractDeveloping motor axons induce synaptic specializations in muscle fibers, including preferential transcription of acetylcholine receptor (AChR) subunit genes by subsynaptic nuclei. One candidate nerve-derived signaling molecule is AChR-inducing activity (ARIA)/heregulin, a ligand of the erbB family of receptor tyrosine kinases. Here, we asked whether ARIA and erbB kinases are expressed in patterns compatible with their proposed signaling roles. In developing muscle, ARIA was present not only at synaptic sites, but also in extrasynaptic regions of the muscle fiber. ARIA was synthesized, rather than merely taken up, by muscle cells, as indicated by the presence of ARIA mRNA in muscle and of ARIA protein in a clonal muscle cell line. ARIA-responsive myotubes expressed both erbB2 and erbB3, but little EGFR/erbB1 or erbB4. In adults, erbB2 and erbB3 were localized to the postsynaptic membrane. ErbB3 was restricted to the postsynaptic membrane perinatally, at a time when ARIA was still broadly distributed. Thus, our data are consistent with a model in which ARIA interacts with erbB kinases on the muscle cell surface to provide a local signal that induces synaptic expression of AChR genes. However, much of the ARIA is produced by muscle, not nerve, and the spatially restricted response may result from the localization of erbB kinases as well as of ARIA. Finally, we show that erbB3 is not concentrated at synaptic sites in mutant mice that lack rapsyn, a cytoskeletal protein required for AChR clustering, suggesting that pathways for synaptic AChR expression and clustering interact

Damage profiles of ultrashallow B implants in Si and the Kinchin-Pease relationship

Damage distributions resulting from 0.1-2 keV B+ implantation at room temperature into Si(100) to doses ranging from 1×1014 to 2×1016 cm-2 have been determined using high-depth-resolution medium-energy-ion scattering in the double alignment mode. For all B+ doses and energies investigated a 3-4 nm deep, near-surface damage peak was observed while for energies at and above 1 keV, a second damage peak developed beyond the mean projected B+ ion range of 5.3 nm. This dual damage peak structure is due to dynamic annealing processes. For the near-surface peak it is observed that, at the lowest implant energies and doses used, for which recombination processes are suppressed due to the proximity of the surface capturing interstitials, the value of the damage production yield for low-mass B+ ions is equal or greater than the modified Kinchin-Pease model predictions [G. H. Kinchin and R. S. Pease, Rep. Prog. Phys. 18, 1 (1955); G. H. Kinchin and R. S. Pease, J. Nucl. Energy 1, 200 (1955); P. Sigmund, Appl. Phys. Lett. 14, 114 (1969)]

Extremely massive disc galaxies in the nearby Universe form through gas-rich minor mergers

© 2022 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. an article which has been published in final form at https://doi.org/10.1093/mnras/stac058In our hierarchical structure-formation paradigm, the observed morphological evolution of massive galaxies -- from rotationally-supported discs to dispersion-dominated spheroids -- is largely explained via galaxy merging. However, since mergers are likely to destroy discs, and the most massive galaxies have the richest merger histories, it is surprising that any discs exist at all at the highest stellar masses. Recent theoretical work by our group has used a cosmological, hydrodynamical simulation to suggest that extremely massive (M* > 10^11.4 MSun) discs form primarily via minor mergers between spheroids and gas-rich satellites, which create new rotational stellar components and leave discs as remnants. Here, we use UV-optical and HI data of massive galaxies, from the SDSS, GALEX, DECaLS and ALFALFA surveys, to test these theoretical predictions. Observed massive discs account for ~13% of massive galaxies, in good agreement with theory (~11%). ~64% of the observed massive discs exhibit tidal features, which are likely to indicate recent minor mergers, in the deep DECaLS images (compared to ~60% in their simulated counterparts). The incidence of these features is at least four times higher than in low-mass discs, suggesting that, as predicted, minor mergers play a significant (and outsized) role in the formation of these systems. The empirical star-formation rates agree well with theoretical predictions and, for a small galaxy sample with HI detections, the HI masses and fractions are consistent with the range predicted by the simulation. The good agreement between theory and observations indicates that extremely massive discs are indeed remnants of recent minor mergers between spheroids and gas-rich satellites.Peer reviewedFinal Accepted Versio

Haemoglobin mass and running time trial performance after recombinant human erythropoietin administration in trained men

<p>Recombinant human erythropoietin (rHuEpo) increases haemoglobin mass (Hbmass) and maximal oxygen uptake (v˙ O2 max).</p> <p>Purpose: This study defined the time course of changes in Hbmass, v˙ O2 max as well as running time trial performance following 4 weeks of rHuEpo administration to determine whether the laboratory observations would translate into actual improvements in running performance in the field.</p> <p>Methods: 19 trained men received rHuEpo injections of 50 IUNkg21 body mass every two days for 4 weeks. Hbmass was determined weekly using the optimized carbon monoxide rebreathing method until 4 weeks after administration. v˙ O2 max and 3,000 m time trial performance were measured pre, post administration and at the end of the study.</p> <p>Results: Relative to baseline, running performance significantly improved by ,6% after administration (10:3061:07 min:sec vs. 11:0861:15 min:sec, p,0.001) and remained significantly enhanced by ,3% 4 weeks after administration (10:4661:13 min:sec, p,0.001), while v˙ O2 max was also significantly increased post administration (60.765.8 mLNmin21Nkg21 vs. 56.066.2 mLNmin21Nkg21, p,0.001) and remained significantly increased 4 weeks after rHuEpo (58.065.6 mLNmin21Nkg21, p = 0.021). Hbmass was significantly increased at the end of administration compared to baseline (15.261.5 gNkg21 vs. 12.761.2 gNkg21, p,0.001). The rate of decrease in Hbmass toward baseline values post rHuEpo was similar to that of the increase during administration (20.53 gNkg21Nwk21, 95% confidence interval (CI) (20.68, 20.38) vs. 0.54 gNkg21Nwk21, CI (0.46, 0.63)) but Hbmass was still significantly elevated 4 weeks after administration compared to baseline (13.761.1 gNkg21, p<0.001).</p> <p>Conclusion: Running performance was improved following 4 weeks of rHuEpo and remained elevated 4 weeks after administration compared to baseline. These field performance effects coincided with rHuEpo-induced elevated v˙ O2 max and Hbmass.</p&gt

Freezing of spin and charge in La_(2-x)Sr_xCuO_4

Zero- and longitudinal-field muon-spin relaxation μ+SR measurements have been performed on La_(2-x)Sr_xCuO_4 alloys in both single-crystal and sintered powder forms above and below their magnetic transition temperatures, T_f. The μ+ precession frequency v depends only weakly on x and T_f, an observation which together with resistivity data implies classical freezing of magnetic moments in the regime where the carriers are localized. For x=0.05, critical dynamics are observed near T_f. The μ^+SR technique is shown to be very sensitive to ferromagnetically aligned pairs of Cu^(2+) moments; the population of such pairs increases greatly with x

Effects of a 6-week Low-Carbohydrate High-Fat Diet on Lipid Profiles in Competitive Recreational Distance Runners

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Sex hormone binding globulin, but not testosterone, is associated with the metabolic syndrome in overweight and obese women with polycystic ovary syndrome

Abstract not availableL.J. Moran, H.J. Teede, M. Noakes, P.M. Clifton, R.J. Norman and G.A. Witterthttp://www.jendocrinolinvest.it/jei/en/abstract.cfm?articolo_id=902