Self-Assembled π-Conjugated Organic/Polymeric Microresonators and Microlasers

Optical microresonators are minute dielectric objects that are utilized as essential components in micrometer-scale light and laser sources, optical integrated circuits, micro-displays, chemo- and biosensors, and so forth. Particularly, microresonators made from organic and polymeric materials find unique applications owing to structural flexibility, color tunability, and functionality with a simple fabrication process, low cost and low energy consumption. In this Account, we highlight our recent progress on organic/polymeric microresonators made through precisely controlled self-assembly. The microstructures display novel optical functions such as circularly polarized luminescence emission, lasing, light energy harvest, optical gate operations, optical memories and authentications, and optical sensing for environmental changes and mechanical forces. Our methodology for the precise design and control of organic and polymeric microstructures will bridge between nanometer-scale supramolecular chemistry and bulk materials and will pave the way toward flexible optical and laser applications.</p

Width-induced metal–insulator transition in SrVO3 lateral nanowires spontaneously formed on the ultrathin film

We investigated lateral nanowires at the topmost layer of SrVO3 (001) ultrathin films using in situ low-temperature scanning tunneling microscopy and spectroscopy. The nanowires were spontaneously formed in the topmost layer of SrVO3 with a (√2 × √2)-R45° reconstruction on the terrace of a (√5 × √5)-R26.6° reconstruction. The electronic states of nanowires were significantly influenced by the nanowire width. With reducing the nanowire width from 5.5 nm to 1.7 nm, the zero-bias conductance of nanowires steeply decreased toward zero, exhibiting a metal–insulator transition possibly driven by dimensional crossover, previously observed in thickness-reduced SrVO3 ultrathin films

Single Molecular Adsorption of Terbium(III) Bis-phthalocyaninato (TbPc2) Governed by Two Surface Reconstructions of Perovskite Type SrVO3 Epitaxial Ultrathin Film

Using low temperature scanning tunneling microscopy (STM), we observed a single molecule magnet, Tb3+ double decker molecule TbPc2 (Pc = phthalocyaninato), adsorbed on a perovskite type transition metal oxide SrVO3 ultrathin film. TbPc2 molecules adsorbed intact and flat on two surface reconstructions of SrVO3, (2–√×2–√)-R45° and (5–√×5–√)-R26.6°, with different configurations. High resolution STM images revealed that the adsorption configurations were governed by the adatom structure of each surface reconstruction according to the proposed adsorption configurations

Quantum oscillations with magnetic hysteresis observed in CeTe3_{3} thin films

We have performed magnetotransport measurements in CeTe$_{3}$ thin films down to $0.2~{\rm K}$. It is known that CeTe$_{3}$ has two magnetic transitions at $T_{\rm N1} \approx 3~{\rm K}$ and $T_{\rm N2} \approx 1~{\rm K}$. A clear Shubnikov-de-Haas (SdH) oscillation was observed at $4~{\rm K}$, demonstrating the strong two-dimensional nature in this material. Below $T_{\rm N2}$, the SdH oscillation has two frequencies, indicating that the Fermi surface could be slightly modulated due to the second magnetic transition. We also observed a magnetic hysteresis in the SdH oscillation below $T_{\rm N1}$. Especially, there is a unique spike in the magnetoresistance at $B \approx 0.6~{\rm T}$ only when the magnetic field is swept from a high enough field (more than $2~{\rm T}$) to zero field.Comment: 5 pages, 4 figures, accepted for publication in Applied Physics Letter

Quantum oscillations with magnetic hysteresis observed in CeTe3 thin films

We have performed magnetotransport measurements in CeTe3 thin films down to 0.2K. It is known that CeTe3 has two magnetic transitions at TN 1 approximate to 3K and TN 2 approximate to 1K. A clear Shubnikov-de-Haas (SdH) oscillation was observed at 4K, demonstrating the strong two-dimensional nature in this material. BelowTN 2, the SdH oscillation has two frequencies, indicating that the Fermi surface could be slightly modulated due to the second magnetic transition. We also observed a magnetic hysteresis in the SdH oscillation below TN 1. Specifically, there is a unique spike in the magnetoresistance at B approximate to 0.6T only when the magnetic field is swept from a high enough field (more than 2T) to zero field

Shubnikov-de-Haas oscillation and possible modification of effective mass in CeTe3 thin films

Magnetoresistance measurements have been performed in CeTe3 thin film devices in a temperature range from 2.1 to 20 K up to 8 T. A clear Shubnikov-de-Haas oscillation was observed in the whole temperature range. The temperature dependence of the oscillation amplitude was found to deviate from the Lifshitz-Kosevich formula below the magnetic transition temperature at T-N1 approximate to 3 K. This indicates a significant interplay between the magnetic ordering and the conduction electrons, which could lead to a modification of the effective cyclotron mass. By analyzing the temperature dependence of the oscillation amplitude, we have estimated the effective mass, quantum lifetime and quantum mobility of the material both in the paramagnetic and antiferromagnetic states

Macrophage numbers in the marginal area of sarcomas predict clinical prognosis

Even when treated comprehensively by surgery, chemotherapy, and radiotherapy, soft-tissue sarcoma has an unfavorable outcome. Because soft-tissue sarcoma is rare, it is the subject of fewer clinicopathological studies, which are important for clarifying pathophysiology. Here, we examined tumor-associated macrophages in the intratumoral and marginal areas of sarcomas to increase our knowledge about the pathophysiology. Seventy-five sarcoma specimens (not limited to a single histological type), resected at our institution, were collected, and the number of CD68-, CD163-, and CD204-positive macrophages in the intratumoral and marginal areas was counted. We then performed statistical analysis to examine links between macrophage numbers, clinical factors, and outcomes. A high number of macrophages positive for all markers in both areas was associated with worse disease-free survival (DFS). Next, we divided cases according to the FNCLCC classification (Grade 1 and Grades 2/3). In the Grade 1 group, there was no significant association between macrophage number and DFS. However, in the Grade 2/3 group, high numbers of CD163- and CD204-positive macrophages in the marginal area were associated with poor DFS. By contrast, there was no significant difference between the groups with respect to high or low numbers of CD68-, CD163-, or CD204-positive macrophages in the intratumoral area. Multivariate analysis identified the number of CD163- and CD204-positive macrophages in the marginal area as an independent prognostic factor. Macrophage numbers in the marginal area of soft-tissue sarcoma may better reflect clinical behavior

A multi-ethnic meta-analysis identifies novel genes, including ACSL5, associated with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating progressive motor neuron disease that affects people of all ethnicities. Approximately 90% of ALS cases are sporadic and thought to have multifactorial pathogenesis. To understand the genetics of sporadic ALS, we conducted a genome-wide association study using 1,173 sporadic ALS cases and 8,925 controls in a Japanese population. A combined meta-analysis of our Japanese cohort with individuals of European ancestry revealed a significant association at the ACSL5 locus (top SNP p = 2.97 × 10−8). We validated the association with ACSL5 in a replication study with a Chinese population and an independent Japanese population (1941 ALS cases, 3821 controls; top SNP p = 1.82 × 10−4). In the combined meta-analysis, the intronic ACSL5 SNP rs3736947 showed the strongest association (p = 7.81 × 10−11). Using a gene-based analysis of the full multi-ethnic dataset, we uncovered additional genes significantly associated with ALS: ERGIC1, RAPGEF5, FNBP1, and ATXN3. These results advance our understanding of the genetic basis of sporadic ALS

A Report on Overseas Teaching Practicum by Graduate Students in Elementary/Secondary Schools in the United States (Ⅶ)

The present reports is on the 7th overseas teaching practicum in the United States by 15 graduate students of Hiroshima University, Japan, partly organized by Hiroshima University Global Partnership School Center since 2007. The group was comprised of 13 elementary school and 2 secondary school education major graduate students. They planned and conducted lessons in English in three local public schools in North Carolina. The expected outcomes of this project were: 1) to self-develop practical instructional competence by teaching pupils with diverse backgrounds in the U.S.; 2) to enhance the abilities in developing teaching materials through hands-on teaching experiences in English; and 3) to acquire the abilities to design, implement and evaluate programs for promoting global partnership. In addition, the teaching experience was followed by cross-cultural study visits to Raleigh, NC and Washington, D.C. It helped to boost our group motivation that the local media, newspaper and TV, and the city Board of Education covered our visit. It is hoped that this project will enhance the students’ teaching competence in designing quality materials/lessons and classroom communication skills in English

模範議会2017 : 記録と資料

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