Lasing from MEH-PPV with a refractive index tunable by electron irradiation.

A simple one-step approach to producing a distributed feedback (DFB) laser through selective irradiation of the gain medium, MEH-PPV, is presented. Electron irradiation alters the refractive index of MEH-PPV, thus, direct patterning by electron irradiation can be applied to create a periodic diffraction grating. The non-irradiated regions of MEH-PPV serve as the primary gain medium, while the irradiated regions of MEH-PPV provide the refractive index difference required to fabricate a DFB laser.

ZnWO Nanoparticle Scintillators for High Resolution X-ray Imaging.

The effect of scintillator particle size on high-resolution X-ray imaging was studied using zinc tungstate (ZnWO) particles. The ZnWO particles were fabricated through a solid-state reaction between zinc oxide and tungsten oxide at various temperatures, producing particles with average sizes of 176.4 nm, 626.

A Novel Route to High-Quality Graphene Quantum Dots by Hydrogen-Assisted Pyrolysis of Silicon Carbide.

Graphene quantum dots (GQDs) can be highly beneficial in various fields due to their unique properties, such as having an effective charge transfer and quantum confinement. However, defects on GQDs hinder these properties, and only a few studies have reported fabricating high-quality GQDs with high crystallinity and few impurities. In this study, we present a novel yet simple approach to synthesizing high-quality GQDs that involves annealing silicon carbide (SiC) under low vacuum while introducing hydrogen (H) etching gas; no harmful chemicals are required in the process.

Biocompatible UV-absorbing polymer nanoparticles prepared by electron irradiation for application in sunscreen.

We present a novel approach to preparing non-toxic sunscreen active ingredients by electron irradiation of poly(methyl methacrylate) (PMMA) and polystyrene (PS) nanoparticles (NPs). Electron irradiation modifies the molecular structure of the polymers, generating conjugated aliphatic carbon-carbon double bonds in PMMA and conjugated aromatic rings in PS. The conjugation length increases as the electron fluence increases, leading to hyperchromic and bathochromic shifts in the UV-vis absorption spectra of the irradiated polymer NPs.

Three-dimensional-printed vaginal applicators for electronic brachytherapy of endometrial cancers.

Purpose: Vaginal applicators for a novel miniature x-ray tube were developed using three-dimensional (3D) printing to be used in brachytherapy of endometrial cancers.

Methods: Cylindrical vaginal applicators with various diameters, lengths, and infill percentages (IFPs) were fabricated using a 3D printer. X-ray dose distributions and depth-dose profiles were calculated using a Monte Carlo simulation.

Patterning of Wrinkled Polymer Surfaces by Single-Step Electron Irradiation.

A novel yet simple approach to fabricate and pattern wrinkled surfaces on polymers is presented. Only by irradiating an electron beam onto a polymer, wrinkles are created on the polymer surface. Electron irradiation produces a bilayer polymeric structure comprising a degrading upper layer and a pristine bottom layer.