Accumulation and depletion layer thicknesses in organic field effect transistors

We present a simple but powerful method to determine the thicknesses of the accumulation and depletion layers and the distribution curve of injected carriers in organic field effect transistors. The conductivity of organic semiconductors in thin film transistors was measured in-situ and continuously with a bottom contact configuration, as a function of film thickness at various gate voltages. Using this method, the thicknesses of the accumulation and depletion layers of pentacene were determined to be 0.9 nm (VG=-15 V) and 5 nm (VG=15 V).Comment: 3 pages, 4 figures, Jap. J. Appl. Phys. in pres

Structural characteristics of the redox-sensing coiled coil in the voltage-gated H^+ channel

This research was originally published in Journal of Biological Chemistry. Yuichiro Fujiwara, Kohei Takeshita, Atsushi Nakagawa and Yasushi Okamura. Structural characteristics of the redox-sensing coiled coil in the voltage-gated H^+ channel. Journal of Biological Chemistry. 2013; 288, 17968-17975. © the American Society for Biochemistry and Molecular Biology

Point-focusing monochromator crystal realized by hot plastic deformation of a Ge wafer

A point-focusing Johansson monochromator crystal prepared by hot-pressing a Ge single-crystal wafer is demonstrated. By using 333 diffraction, Cu Kα radiation was focused onto a small spot

Stabilization of a honeycomb lattice of IrO6_6 octahedra in superlattices with ilmenite-type MnTiO3_3

In the quest for quantum spin liquids, thin films are expected to open the way for the control of intricate magnetic interactions in actual materials by exploiting epitaxial strain and two-dimensionality. However, materials compatible with conventional thin-film growth methods have largely remained undeveloped. As a promising candidate towards the materialization of quantum spin liquids in thin films, we here present a robust ilmenite-type oxide with a honeycomb lattice of edge-sharing IrO$_6$ octahedra artificially stabilized by superlattice formation with an ilmenite-type antiferromagnetic oxide MnTiO$_3$. The stabilized sub-unit-cell-thick Mn-Ir-O layer is isostructural to MnTiO$_3$, having the atomic arrangement corresponding to ilmenite-type MnTiO$_3$ not discovered yet. By spin Hall magnetoresistance measurements, we found that antiferromagnetic ordering in the ilmenite Mn sublattice is suppressed by modified magnetic interactions in the MnO$_6$ planes via the IrO$_6$ planes. These findings lay the foundation for the creation of two-dimensional Kitaev candidate materials, accelerating the discovery of exotic physics and applications specific to quantum spin liquids

Impact of sea-ice dynamics on the spatial distribution of diatom resting stages in sediments of the Pacific Arctic region

Author Posting. © American Geophysical Union, 2021. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 126(7), (2021): e2021JC017223, https://doi.org/10.1029/2021JC017223.The Pacific Arctic region is characterized by seasonal sea-ice, the spatial extent and duration of which varies considerably. In this region, diatoms are the dominant phytoplankton group during spring and summer. To facilitate survival during periods that are less favorable for growth, many diatom species produce resting stages that settle to the seafloor and can serve as a potential inoculum for subsequent blooms. Since diatom assemblage composition is closely related to sea-ice dynamics, detailed studies of biophysical interactions are fundamental to understanding the lower trophic levels of ecosystems in the Pacific Arctic. One way to explore this relationship is by comparing the distribution and abundance of diatom resting stages with patterns of sea-ice coverage. In this study, we quantified viable diatom resting stages in sediments collected during summer and autumn 2018 and explored their relationship to sea-ice extent during the previous winter and spring. Diatom assemblages were clearly dependent on the variable timing of the sea-ice retreat and accompanying light conditions. In areas where sea-ice retreated earlier, open-water species such as Chaetoceros spp. and Thalassiosira spp. were abundant. In contrast, proportional abundances of Attheya spp. and pennate diatom species that are commonly observed in sea-ice were higher in areas where diatoms experienced higher light levels and longer day length in/under the sea-ice. This study demonstrates that sea-ice dynamics are an important determinant of diatom species composition and distribution in the Pacific Arctic region.This work was conducted by the Arctic Challenge for Sustainability (ArCS) project, Arctic Challenge for Sustainability II (ArCSII) project and ArCS program for overseas visits by young researchers. In addition, this work was partly supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number JP20J20410 and JP21H02263. We thank Anderson laboratory members for their support of our study at WHOI, and also thank Robert Pickart, Leah McRaven, and Jacqueline Grebmeier for their support and assistance on the Healy cruises. Funding for DA, EF, and MR was provided by the NOAA Arctic Research Program through the Cooperative Institute for the North Atlantic Region (CINAR Award NA14OAR4320158), by the NOAA ECOHAB Program (NA20NOS4780195) and by the National Science Foundation Office of Polar Programs (OPP-1823002). This is ECOHAB contribution number ECO986.2021-12-1

Clinical Application of Unidirectional Porous Hydroxyapatite to Bone Tumor Surgery and Other Orthopedic Surgery

Unidirectional porous hydroxyapatite (UDPHAp) was developed as a remarkable scaffold characterized by a distinct structure with unidirectional pores oriented in the horizontal direction and connected through interposes. We evaluated the radiographic changes, clinical outcomes, and complications following UDPHAp implantation for the treatment of bone tumors. Excellent bone formation within and around the implant was observed in all patients treated with intralesional resection and UDPHAp implantation for benign bone tumors. The absorption of UDPHAp and remodeling of the bone marrow space was observed in 45% of the patients at a mean of 17 months postoperatively and was significantly more common in younger patients. Preoperative cortical thinning was completely regenerated in 84% of patients at a mean of 10 months postoperatively. No complications related to the implanted UDPHAp were observed. In a pediatric patient with bone sarcoma, when the defect after fibular resection was filled with UDPHAp implants, radiography showed complete resorption of the implant and clear formation of cortex and marrow in the resected part of the fibula. The patient could walk well without crutches and participate in sports activities. UDPHAp is a useful bone graft substitute for the treatment of benign bone tumors, and the use of this material has a low complication rate. We also review and discuss the potential of UDPHAp as a bone graft substitute in the clinical setting of orthopedic surgery