Icosahedral order has been suggested as the prevalent atomic motif of supercooled liquids and metallic glasses for more than half a century, because the icosahedron is highly close-packed but is difficult to grow, owing to structure frustration and the lack of translational periodicity. By means of angstrom-beam electron diffraction of single icosahedra, we report experimental observation of local icosahedral order in metallic glasses. All the detected icosahedra were found to be distorted with partially face-centered cubic symmetry, presenting compelling evidence on geometric frustration of local icosahedral order in metallic glasses.

We measured the fluorescence quantum yield (Φf) of several aromatic hydrocarbon crystals: p-terphenyl, trans-stilbene, anthracene, pyrene, and α-perylene. The Φf is reduced by chemical impurities, structural defects, and reabsorption of fluorescence. To minimize the effect of chemical impurities and structural defects, we evaluated the Φf of highly purified single crystals. We also measured the Φf of powder samples prepared by the mechanical milling of single crystals to assess the effect of reabsorption and structural defects induced by milling. We estimated the lower limit values of the Φf to be 0.80 for p-terphenyl, >0.65 for trans-stilbene, >0.64 for anthracene, 0.68 for pyrene, and 0.31 for α-perylene.

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Poly(N-vinylpyrrolidone)s (PNVPs) with well-defined macromolecular structure were prepared by organostibine-mediated living radical polymerization. PNVPs with expected number-average molecular weight (M n ) 3000-84 000) and low polydispersity indexes (PDIs ) 1.1-1.3) were formed by heating a solution of organostibine mediator and NVP in the presence of AIBN at 60 °C. The polymer structure was analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI TOF) mass and 2 H NMR spectroscopies after reduction of the organostibanyl polymer end by tributyltin deuteride. The analyses reveal that, while the addition of AIBN considerably enhances the rate of the polymerization, the effect of azobis(isobutyronitrile) (AIBN)derived radical to the ω-end structure is negligible. The analyses also reveal the existence of "dead" dormant species due to head-to-head addition followed by the organostibanyl group transfer. However, since the probability of the head-to-head addition is small (0.02-0.10%) compared to the normal head-to-tail addition, its effect on the controllability was negligible under the current conditions. Diblock copolymers poly(styrene [St]-block-NVP), poly(methyl methacrylate [MMA]-block-NVP), and poly(NVP-block-MMA) were successfully prepared by successive addition of corresponding monomers to the organostibine macromediators.

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These results suggest that BMS is safe and useful to monitor pulmonary biochemical events in ARDS.

IL-1 receptor antagonist-deficient (IL-1Ra -/-) mice spontaneously develop autoimmune arthritis. We demonstrate here that T cells are required for the induction of arthritis; T cell-deficient IL-1Ra -/-mice did not develop arthritis, and transfer of IL-1Ra -/-T cells induced arthritis in nu/nu mice. Development of arthritis was also markedly suppressed by TNF-α deficiency. We found that TNF-α induced OX40 expression on T cells and blocking the interaction between either CD40 and its ligand or OX40 and its ligand suppressed development of arthritis. These findings suggest that IL-1 receptor antagonist deficiency in T cells disrupts homeostasis of the immune system and that TNF-α plays an important role in activating T cells through induction of OX40.