Probing of Transient Electric Field Distribution in ITO/PI/P3HT/Au By Time-Resolved Optical Second Harmonic Generation Measurement

AbstractBy using time-resolved optical second harmonic generation (TR-SHG) measurements, we studied carrier behaviors in poly(3-hexylthiophene) (P3HT) metal-insulator-semiconductor (MIS) diodes. TR-SHG measurements probed transients of electric fielddistribution in the P3HT active layer. Results showed that hole injection and removal processes were non-reversal, where the response times were different from each other and the relaxation time of the transient electric field strongly depended on the hole injection process

Picosecond pulse radiolysis: Dynamics of solvated electrons in ionic liquid and geminate ion recombination in liquid alkanes

金沢大学理工研究域自然システム学系A picosecond pulse radiolysis facility based on a laser-driven photocathode electron accelerator has been constructed. First observation of picosecond dynamics in ionic liquid of DEMMA-TFSI in radiation chemistry was reported. It is found that the electrons produced by ionization are solvated to full solvation in ionic liquid with a rate constant of 3.9×1010 s-1, and dry electrons before full solvation react rapidly with biphenyl and pyrene with a rate constant of 3.8-7.9×1011 dm3 mol-1 s-1. The geminate ion recombination in n-dodecane and n-hexane was also observed by monitoring transient optical absorption at 523 nm. © 2008 Elsevier Ltd. All rights reserved

Postazacitidine clone size predicts long-term outcome of patients with myelodysplastic syndromes and related myeloid neoplasms

Azacitidine is a mainstay of therapy for MDS-related diseases. The purpose of our study is to elucidate the effect of gene mutations on hematological response and overall survival (OS), particularly focusing on their post-treatment clone size. We enrolled a total of 449 patients with MDS or related myeloid neoplasms. They were analyzed for gene mutations in pre- (n=449) and post- (n=289) treatment bone marrow samples using targeted-capture sequencing to assess the impact of gene mutations and their post-treatment clone size on treatment outcomes. In Cox proportional hazard modeling, multi-hit TP53 mutation (HR, 2.03; 95% CI, 1.42-2.91; P<.001), EZH2 mutation (HR, 1.71; 95% CI, 1.14-2.54; P=.009), and DDX41 mutations (HR, 0.33; 95% CI, 0.17-0.62; P<.001), together with age, high-risk karyotypes, low platelet, and high blast counts, independently predicted OS. Post-treatment clone size accounting for all drivers significantly correlated with International Working Group (IWG)-response (P<.001, trend test), except for that of DDX41-mutated clones, which did not predict IWG-response. Combined, IWG-response and post-treatment clone size further improved the prediction of the original model and even that of a recently proposed molecular prediction model, IPSS-M (c-index, 0.653 vs 0.688; P<.001, likelihood ratio test). In conclusion, evaluation of post-treatment clone size, together with pre-treatment mutational profile as well as IWG-response have a role in better prognostication of azacitidine-treated myelodysplasia patients

Development of New Medical Devices Using Crosslinking Techniques with Quantum Beams

文科省の委託に基づき、原子力安全研究協会が発行しているニュースレターにおいて、研究員受入れ研究室の研究アクティビティーの紹介を行った

Development of Environmentally Friendly Cellulose Derivative-Based Hydrogels for Contact Lenses Using a Radiation Crosslinking Technique

Although they have potential environmental pollution issues, soft contact lenses are value-added biodevices for medical use. Thus, it is important to reconsider starting materials and production methods to achieve sustainable development. In this study, hydrogels composed of hydroxypropyl cellulose (HPC) as an environmentally friendly material were produced by radiation and investigated for use in disposable soft contact lenses. HPC-based hydrogels with good mechanical properties and transparency were prepared by irradiation of electron beams on highly concentrated aqueous solutions containing HPC, polyethylene glycol #1000 dimethacrylate (23G), and 2-hydroxyethyl methacrylate (HEMA). The addition of 23G to HPC aqueous solutions resulted in an increase in the gel fraction as well as improved mechanical properties, such as tensile strength and elongation at break. The tensile strength and the elongation at break of HPC/HEMA/23G hydrogel obtained by the further addition of HEMA with HPC/23G aqueous solutions exhibited 0.2 MPa and 124%, which were approximately 2.0 and 1.8 times larger than these of the pure HPC hydrogel, respectively. The evaluation of the properties of the HPC/HEMA/23G hydrogel demonstrated its potential as a soft contact material with improved mechanical properties

Electron-blocking hole-transport polyterpenol thin films

The carrier blocking property of polyterpenol thin films derived from non-synthetic precursor is studied using Electric Field Induced Optical Second Harmonic Generation (EFISHG) technique that can directly probe carrier motion in organic materials. A properly biased double-layer MIM device with a structure of indium zinc oxide (IZO)/polyterpenol/C₆₀/Al shows that by incorporating the polyterpenol thin film, the electron transport can be blocked while the hole transport is allowed. The inherent electron blocking hole transport property is verified using Al/C₆₀/Alq3/polyterpenol/IZO and Al/Alq3/polyterpenol/IZO structures. The rectifying property of polyterpenol is very promising and can be utilized in the fabrication of many organic devices