We have studied the local structure of superconducting Ca10Pt4As8(Fe2As2)5 (Pt10418) and Ca10Ir4As8(Fe2As2)5 (Ir10418) iron arsenides, showing different transition temperatures (Tc=38 and 16 K, ...respectively), by polarized Fe K-edge extended x-ray absorption fine-structure measurements. Despite the similar average crystal structures, the local structures of the FeAs4 tetrahedra in the two compounds are found to be very different. The FeAs4 in Pt10418 is close to a regular tetrahedron, while it deviates largely in Ir10418. The Fe-Fe correlations in the two compounds are characterized by similar bond-length characteristics; however, the static disorder in Pt10418 is significantly lower than that in Ir10418. The results suggest that the optimized local structure and reduced disorder are the reasons for higher Tc and well-defined electronic states in Pt10418 unlike Ir10418 showing the coexistence of glassy and normal electrons at the Fermi surface, and hence provide direct evidence of the local-structure-driven optimization of the electronic structure and superconductivity in iron arsenides.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Background:
Although G-protein-coupled receptor, GPR30, has been considered as a G-protein-coupled estrogen receptor, conflicting results have been reported and the function of GPR30 in bone remains ...unresolved. The aim of this study was to clarify the functional role of GPR30 in osteoblasts using its derived cell line.
Methods and results:
Immunohistochemical study revealed that GPR30 is expressed in human osteoblasts. Human fetal osteoblast cell lines, hFOB cells, which express GPR30 but lack estrogen receptor, were used for the
in vitro
experiments. Estradiol or raloxifene induced the proliferation of hFOB cells, which was accompanied by the activation of mitogen-activated protein (MAP) kinase. Those proliferative effects were completely abrogated by the transfection of GPR30 small interfering RNA, while the transfection alone did not affect the cell viability.
Conclusion:
GPR30 is required for the proliferation of hFOB cells induced by estradiol or raloxifene. This proliferative effect was at least partly mediated
via
MAP kinase activation. These findings revealed a novel function of GPR30 in osteoblasts and might lead to a better understanding of how estrogen and selective estrogen receptor modulators show their osteoprotective effects.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The distribution pattern and competition of insects exploiting Camellia japonica flowers were studied in Tokyo, central Japan, to understand how their distributions are determined. Dasiops sp. of ...Lonchaeidae (Diptera) exploited flower buds and showed random distribution, whereas Drosophila unipectinata, D. oshimai and D. lutescens of Drosophilidae (Diptera) and Epuraea commutata of Nitidulidae (Coleoptera) exploited fully opened, late and fallen flowers and showed aggregated distribution. From the distribution pattern, it is assumed that Dasiops sp. has clutches of single egg whereas drosophilid and nitidulid species have clutches of more than one egg. In resource supplementary experiments, body size of drosophilid flies increased if resources were supplemented, although their survival is assumed to be unaffected. However, their body size did not decrease with increase of larval density in resource patches. It is therefore unclear whether resource competition occurs among drosophilid flies in Camellia flowers in nature. From the present and previous studies, it is assumed that aggregation (or production of clutches of more than one egg) is related to the use of fermenting or decayed resources; aggregation might increase larval survival and/or performance under the presence of molds or microorganisms.
Dasiops sp. exploited flower buds and showed random distribution, whereas Drosophila unipectinata, D. oshimai, D. lutescens and Epuraea commutata of Nitidulidae (Coleoptera) exploited fully‐opened, late and fallen flowers and showed aggregated distribution. Aggregated distribution seems to arise by production of clutches containing more than one egg and may be an adaptation to use fermenting or decayed resources.
Full text
Available for:
DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Er–Si–O crystal is one of the promising materials for Si-based opto-electronic devices. Crystallization of Er–Si–O is obtained by solid phase reaction of an amorphous preform which contains Er–O and ...Si–O bonds. However detailed crystallization mechanism is not clear. This study reports that the control of oxygen content of the sample in the annealing process for crystallization affects the fine arrangements of Er–Si–O crystals, resulting in three different types of XRD patterns and correspondingly different PL spectrum fine structures.
The sol–gel method was used to prepare the amorphous preform. The samples were then annealed at 1250
°C in Ar for the solid phase growth of Er–Si–O crystals. The obtained Er–Si–O crystals showed, however, some different types of XRD patterns and the PL spectra. It was speculated that a slight amount of residual oxygen in the annealing furnace affected the Er–Si–O crystal structure. To study the effect of oxygen, during solid phase growth three processes were applied; putting a Si cap on the sample to reduce the influence of the atmosphere, additionally putting a carbon sheet as oxygen getter on the sample covered with a Si cap and no Si capping. Three kinds of XRD patterns, PL spectrum fine structures, PLE spectra and PL time decays were observed, depending on the three processes. These results indicate that the fine arrangements of Er–Si–O crystals are affected by oxygen content in the crystal which is very sensitive to oxygen in the annealing Ar atmosphere during the solid phase growth and their properties are come from their particular crystalline structures.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
PDF
