The structure of sputtered amorphous Ge 2 Sb 2 Te 5 was investigated by high energy X-ray diffraction, neutron diffraction and Ge-, Sb-and Te K-edge EXAFS measurements. The five datasets were modelled simultaneously in the framework of the reverse Monte Carlo simulation technique. It was found that apart from Te-Sb and Te-Ge bonds existing in the crystalline phases Ge-Ge and Sb-Ge bonding is also significant in sputtered amorphous Ge 2 Sb 2 Te 5 . According to our results all components obey the '8-N' rule.

Minimally invasive investigation of plant parts (root, stem, leaves, and flower) has good potential to elucidate the dynamics of plant growth, morphology, physiology, and root-rhizosphere interactions. Laboratory based absorption X-ray imaging and computed tomography (CT) systems are extensively used for in situ feasibility studies of plants grown in natural and artificial soil. These techniques have challenges such as low contrast between soil pore space and roots, long X-ray imaging time, and low spatial resolution. In this study, the use of synchrotron (SR) based phase contrast X-ray imaging (PCI) has been demonstrated as a minimally invasive technique for imaging plants. Above ground plant parts and roots of 10 day old canola and wheat seedlings grown in sandy clay loam soil were successfully scanned and reconstructed. Results confirmed that SR-PCI can deliver good quality images to study dynamic and real time processes such as cavitation and water-refilling in plants. The advantages of SR-PCI, effect of X-ray energy, and effective pixel size to study plant samples have been demonstrated. The use of contrast agents to monitor physiological processes in plants was also investigated and discussed.

Macrophage-derived chemokine [CC chemokine ligand 22 (CCL22)] and thymus- and activation-regulated chemokine (CCL17) mediate cellular effects, principally by binding to their receptor CC chemokine receptor 4 (CCR4) and together, constitute a multifunctional chemokine/receptor system with homeostatic and inflammatory roles within the body. This study demonstrates that CCL22 and CCL17 stimulate pertussis toxin-sensitive elevation of intracellular calcium in the CEM leukemic T cell line and human peripheral blood-derived T helper type 2 (Th2) cells. Inhibition of phospholipase C (PLC) resulted in the abrogation of chemokine-mediated calcium mobilization. Chemokine-stimulated calcium responses were also abrogated completely by the inhibition of inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] receptor-mediated calcium release. Chemotactic responses of CEM and human Th2 cells to CCL17 and CCL22 were similarly abrogated by inhibition of PLC and inhibition of novel, Ca2+-independent/diacylglycerol-dependent protein kinase C (PKC) isoforms. Inhibition of Ins(1,4,5)P3 receptor-mediated calcium release from intracellular stores had no effect on chemotactic responses to CCR4 ligands. Taken together, this study provides compelling evidence of an important role for PLC and diacylglycerol-dependent effector mechanisms (most likely involving novel PKC isoforms) in CCL17- and CCL22-stimulated, directional cell migration. In this regard, CCL22 stimulates phosphatidylinositol-3 kinase-independent phosphorylation of the novel delta isoform of PKC at threonine 505, situated within its activation loop--an event closely associated with increased catalytic activity.

IL-17-producing Th cells (Th17) are a distinct subset of effector cells that bridge the innate and adaptive immune system and are implicated in autoimmune disease processes. CD4(+) splenocytes from DO11.10 mice were activated with OVA peptide(323-339) and maintained under Th17 polarization conditions, resulting in significantly higher proportions of IL-17(+) T cells compared with nonpolarized (Th0) cells. Th17-polarizing conditions significantly increased the proportion of cells expressing the chemokine receptors CCR2, CCR6, and CCR9 when compared with Th0 cells. In contrast, there was a significant decrease in the proportion of cells expressing CXCR3 under Th17-polarizing conditions compared with nonpolarizing conditions. The respective chemokine agonists for CCR2 (CCL2 and CCL12), CCR6 (CCL20), and CCR9 (CCL25) elicited migration and PI-3K-dependent signaling events in Th17-polarized cells, thus indicating that all three receptors were functionally and biochemically responsive. Furthermore, postmigration phenotypic analysis demonstrated that the agonists for CCR2 and CCR6, but not CCR9, stimulated a modest enrichment of IL-17(+) cells compared with the premigration population. Pan-isoform inhibitors of PI-3K/Akt signaling prevented CCR2- and CCR6-mediated, polarized Th17 cell migration in a concentration-dependent manner. The unique chemokine receptor expression pattern of Th17 cells and their corresponding PI-3K-dependent migratory responses are important for understanding the pathogenesis of autoimmune diseases and may provide opportunities for the application of CCR2 and CCR6 antagonists and PI-3K isoform-selective inhibitors in defined inflammatory settings.

The local structure around neodymium in an aluminoborosilicate glass bearing 3.6 mol% Nd 2 O 3 is studied by optical absorption spectroscopy and EXAFS at the Nd L III -and K-edges. The influence of the nature of alkalis (M + = Li + , Na + , K + , Rb + , Cs + ) and alkalineearths (M 2+ = Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ ) on the coordination sphere of Nd 3+ ions in the glass is particularly investigated. The Nd 3+ sites are well-defined with NdAO mean distances of 2.46 ± 0.03 Å , whatever the alkali and alkaline-earth ion type except Li + and Mg 2+ , for which glasses exhibit slightly more disordered Nd sites and longer NdAO distances (2.49 ± 0.03 Å ). Using bond valence considerations, a model is proposed for the Nd site, and consists in 7-8 non-bridging oxygens (NBO), every NBO being charge compensated by 2-3 alkalis and alkaline-earths. The NdAO mean distance is adjusted according to the mean field strength of these cations, to avoid overbonding of the NBO's. A glass series with varying Ca 2+ /Na + concentration ratio shows that Nd 3+ cations are able to maintain this average coordination site even at high alkaline-earth content.

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We summarize the results of a number of hard X-ray measurements on cerium doped LaCl 3 and LaBr 3 scintillators. The experiment was carried out at the HASYLAB synchrotron radiation facility using highly monochromatic pencil beams across the energy range 10.5 keV to 100 keV. Additional full-area measurements were carried out using radioactive sources. All measurements were carried out at room temperature. The measured FWHM energy resolutions (ΔE/E) under pencil beam illumination were 29% (LaBr 3 ) and 32.4% (LaCl 3 ) at 10.5 keV falling to 7.8% (LaBr 3 ) and 9.2% (LaCl 3 ) at 100 keV. At 662 keV, the energy resolutions were 3.9% and 3.0% FWHM. The proportionality of the energy responses shows marked deviations from linearity above and below the La edge at 39.8 keV. At the edge the energy response changes by 2%. Fine structure across the edge was also investigated using single photon count rate measurements taken in 1 eV steps across the edge. The data show considerable near-edge structure when compared to curves generated from standard atomic data tables. However, very little evidence was found for extended X-ray fine structure suggesting that the bulk of the structure arises from the local coordination environment.

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