Tunable broadband terahertz polarizer using graphene-metal hybrid metasurface

We demonstrate an electrically tunable polarizer for terahertz (THz) frequency electromagnetic waves formed from a hybrid graphene-metal metasurface. Broadband (>3 THz) polarization-dependent modulation of THz transmission is demonstrated as a function of the graphene conductivity for various wire grid geometries, each tuned by gating using an overlaid ion gel. We show a strong enhancement of modulation (up to ∼17 times) compared to graphene wire grids in the frequency range of 0.2–2.5 THz upon introduction of the metallic elements. Theoretical calculations, considering both plasmonic coupling and Drude absorption, are in good agreement with our experimental findings

The mechanism of energy transfer from Si nanocrystals to Er ions in SiO

The mechanism of energy transfer from silicon nanocrystals (Si-nc's) to erbium (Er) ions is studied by analyzing time transient of Er photoluminescence at 1.54 ${\mu}$m. It is shown that two different energy transfer mechanisms, i.e., fast and slow, exist in SiO2 films containing Si-nc's and Er ions, and that the ratio of slow to fast processes depends on size of Si-nc's and Er concentration. A quantitative analysis reveals that Er ions located within about 1.5 nm from the surface of Si-nc's are excited by the fast process, and those located within about 2.5 nm by the slow process if no Er ions exist within 1.5 nm from the surface. Er ions staying outside these regions cannot be sensitized by Si-nc's

Graphene-Assisted Controlled Growth of Highly Aligned ZnO Nanorods and Nanoribbons: Growth Mechanism and Photoluminescence Properties

We demonstrate graphene-assisted controlled fabrication of various ZnO 1D nanostructures on the SiO₂/graphene substrate at a low temperature (540 °C) and elucidate the growth mechanism. Monolayer and a few layer graphene prepared by chemical vapor deposition (CVD) and subsequently coated with a thin Au layer followed by rapid thermal annealing is shown to result in highly aligned wurtzite ZnO nanorods (NRs) with clear hexagonal facets. On the other hand, direct growth on CVD graphene without a Au catalyst layer resulted in a randomly oriented growth of dense ZnO nanoribbons (NRBs). The role of in-plane defects and preferential clustering of Au atoms on the defect sites of graphene on the growth of highly aligned ZnO NRs/nanowires (NWs) on graphene was established from micro-Raman and high-resolution transmission electron microscopy analyses. Further, we demonstrate strong UV and visible photoluminescence (PL) from the as-grown and post-growth annealed ZnO NRs, NWs, and NRBs, and the origin of the PL emission is correlated well with the X-ray photoelectron spectroscopy analysis. Our results hint toward an epitaxial growth of aligned ZnO NRs on graphene by a vapor–liquid–solid mechanism and establish the importance of defect engineering in graphene for controlled fabrication of graphene–semiconductor NW hybrids with improved optoelectronic functionalities

Supplementary Material for: Successful rechallenge with osimertinib following osimertinib-induced ventricular tachycardia: A case report

Osimertinib, a third-generation tyrosine kinase inhibitor, is the first-line treatment for metastatic non-small cell lung cancer (NSCLC) with sensitizing epidermal growth factor receptor mutations. It is known to cause drug-induced cardiotoxicity, including QT prolongation syndrome, heart failure, and ventricular arrhythmias, which can lead to sudden death. Once severe arrhythmias occur, it is difficult to continue osimertinib treatment. We report a case of a 66-year-old woman with recurrent NSCLC after concurrent chemoradiotherapy who experienced osimertinib-induced ventricular arrhythmia causing syncope. The patient was initially treated with concurrent chemoradiotherapy, and genetic testing revealed epidermal growth factor receptor (EGFR) exon 19 deletion. Three years following treatment initiation, the primary tumor progressed, and new bone metastases developed. The patient was diagnosed with recurrent NSCLC and was treated with targeted therapy with osimertinib. On the 10th day of osimertinib administration, syncope occurred. An electrocardiogram showed polymorphic non-sustained ventricular tachycardia, thought to be the cause of syncope. The patient was switched to erlotinib. Two and a half years later, disease progression of the primary lesion was observed. Liquid biopsy showed EGFR T790M resistance mutation. Therefore, osimertinib (40 mg) every other day was started. After confirming the absence of palpitations and of arrhythmias on ECG, osimertinib dosing was increased to 40 mg daily. Thereafter, no further events occurred, and tumor shrinkage was observed. Low-dose osimertinib rechallenge after induced ventricular arrhythmia may be considered as an option under close monitoring; however, osimertinib rechallenge must be carefully selected based on the risk-benefit analysis