Effects of the crystallization temperature on the crystal structure and its melting behavior of poly (l-lactic acid) (PLLA) have been investigated by means of wide-angle (WAXS) and small-angle (SAXS) X-ray scattering, optical microscopy, and differential scanning calorimetory (DSC). PLLA was found to crystallize as the α form when the crystallization temperature T c was higher than 120 °C, while significant change in lattice parameters was seen for T c's below 120 °C. The ratio of the a- and b-axis lengths begins to decrease with T c below 120 °C and is 31/2 below 90 °C, which suggests a new crystalline form with hexagonal packing, namely, the α‘ form. The possible reason for α‘ formation is discussed. High-temperature WAXS and SAXS measurements showed that α‘ crystal transforms into ordered a form during heating. The transition takes place at 150 °C without a decrease in scattering intensity and without heating rate dependence. The mechanism for the transition is discussed.

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Green nanocomposites based on renewable plant oils have been developed. Curing of epoxidized plant oils in the presence of organophilic montmorillonite produced triglyceride−clay nanocomposites showing flexible property. A nanocomposite with homogeneous structure was obtained, in which silicate layers of the clay were intercalated and randomly distributed in the polymer matrix.

Alkyl-modified crystalline silicon nanosheets 2 were synthesized and maintained the crystal structure of a Si(111) plane, in which the dangling silicon bond is stabilized by capping with the alkyl group. 2 was characterized using UV-vis, Fourier transform-infrared, and X-ray photoelectron spectroscopies; X-ray diffraction; and X-ray absorption near edge structure analysis. A model structure is proposed that has a periodicity through the nanosheet surface.

Background: The precise pathogenesis of alopecia areata remains unknown, although this disease seems to be triggered by helper T cell infiltration in hair follicles. Recent studies of psoriasis and vitiligo have demonstrated the involvement of Th17 cells. Psoriasis and vitiligo occasionally develop concomitantly or inversely in patients with alopecia areata. Objective: The aim of this study was to determine whether Th17 cells are present in the affected lesions of alopecia areata. Methods: We performed immunofluorescent staining of representative immunocompetent cells that had infiltrated into the skin of the scalp in 4 individuals with alopecia areata (single patchy alopecia areata, multiple patchy alopecia areata, alopecia totalis and alopecia universalis). Results: We found the infiltration of CD4⁺IL-17A⁺ Th17 cells in the dermis, particularly around hair follicles, in all 4 cases. Conclusions: These findings suggest the possibility that alopecia areata is induced by a Th17 cell-associated autoimmune mechanism.

This study deals with the preparation and properties of a new class of organic-inorganic hybrids from renewable resources. The hybrids were synthesized by an acid-catalyzed curing of epoxidized triglycerides in the presence of an organophilic montmorillonite (a modified clay). The mechanical properties were improved by the incorporation of clay in the oil-based polymer matrix. The reinforcement effect due to the addition of clay was confirmed by dynamic viscoelasticity analysis. The hybrids showed relatively high thermal stability. The co-curing of epoxidized soybean and linseed oils in the presence of clay produced hybrids with controlled mechanical and coating properties. The barrier property of the hybrid towards water vapor was superior to that of the oil polymer. The development of the present hybrids consisting of inexpensive renewable resources, triglyceride and clay is expected to contribute to global sustainability.

In this paper, we investigate the Eddy current (EC) losses in the rotors of surface permanent-magnet (PM) synchronous machines, which have concentrated armature windings. By the finite-element method (FEM) analysis, it is clear that the EC losses in rotors are apparently different at rated currents if the pole and slot combinations are different. The distribution of the EC density in the rotor is closely related with the asynchronous components of the armature magnetomotive force (MMF). If the armature MMF has a low order of spatial harmonic components, which is not synchronous with the rotor, the EC losses are of large amounts.Index Terms-Eddy current (EC), loss, magnetomotive force (MMF), rotor, surface permanent-magnet synchronous machine.

The polymerization of tert-butylacetylene (tBA) by the MoOCL-n-BiqSn-EtOH (1:1:1) catalyst led to living and stereoregular polymers with narrow molecular weight distributions (Mm/Mn = 1.12; cis 97%). The living nature of this polymerization was confirmed by the fact that, in toluene at 0 and -30 °C, the Mn of the polymer increases in direct proportion to monomer consumption, while the molecular weight distribution remains narrow.The cis content of the polymer was evaluated by 13C NMR spectroscopy. Similar but somewhat inferior results were obtained with the MoClg-n-BuqSn-EtOH (1:1:1) system (MjMn = 1.24; cis 90%). Besides the narrow molecular weight distribution and high cis specificity, the features of these polymerizations include large reaction rates (e.g., completed within 1 min at 0 °C) and rather low initiator efficiencies ([P*]/[Cat] ~2%).