Microstructured organic cavities with high-reflective flat reflectors fabricated by using a nanoimprint-bonding process

The integration of photonic microstructure into organic microcavities represents an effective strategy for manipulating eigenstates of cavity or polariton modes. However, well-established fabrication processes for microstructured organic microcavities are still lacking. In this study, we propose a nanoimprint-bonding process as a novel fabrication method for microstructured organic microcavities. This process relies on a UV nanoimprint technique utilizing two different photopolymer resins, enabling the independent fabrication of highly reflective reflectors and photonic microstructures without compromising the accuracy of each. The resulting organic microcavities demonstrate spatially localized photonic modes within dot structures and their nonlinear responses on the pumping fluence. Furthermore, a highly precise photonic band is confirmed within a honeycomb lattice structure, which is owing to the high quality factor of the cavity achievable with the nanoimprint-bonding process. Additionally, a topological edge state is also observable within a zigzag lattice structure. These results highlight the significant potential of our fabrication method for advancing organic-based photonic devices, including lasers and polariton devices

Rashba-Dresselhaus spin-orbit coupling and polarization-coupled luminescence in an organic single crystal microcavity

Spin-orbit coupling (SOC) of light plays a fundamental photophysics that is important for various fields such as materials science, optics, and quantum technology, contributing to the elucidation of new physical phenomena and the development of innovative applications. In this study, we investigate the impact of SOC in a microcavity system using the highly oriented molecular crystal. The unique molecular alignment of our crystal creates substantial optical anisotropy, enabling the observation of significant SOC effects within a microcavity form. Through angle-resolved photoluminescence measurements and theoretical calculations, the presence of Rashba-Dresselhaus (RD) SOC in the lower branch of polariton modes is revealed. We have observed for the first time polarization-coupled emission from polariton modes due to the RD-SOC effect in a microcavity with a medium having both strong light-matter coupling and strong optical anisotropy. Theoretical investigations further elucidate the intricate interplay between the RD-SOC effect and anisotropic light-matter coupling, leading to the emergence of both circularly and diagonally polarized mode splittings. This study not only advances our understanding of optical SOC in microcavities but also highlights the potential of highly oriented molecular crystals in manipulating SOC effects without external electric or magnetic fields. These findings offer greatly promising platforms for developing topological photonics and quantum technologies

Microwave hinge states in a simple-cubic-lattice photonic crystal insulator

We numerically and experimentally demonstrated a higher-order topological state in a three-dimensional (3D) photonic crystal (PhC) with a complete photonic bandgap. Two types of cubic lattices were designed with different topological invariants, which were theoretically and numerically confirmed by the finite difference of their Zak phases. Topological boundary states in the two-dimensional interfaces and hinge states in the one-dimensional corners were formed according to the higher-order of bulk-boundary correspondence. Microwave measurements of the fabricated 3D PhC containing two boundaries and one corner showed a localized intensity, which confirmed the boundary and hinge states.Comment: 8 pages, 6 figure

Epigenetic Silencing of HOPX Promotes Cancer Progression in Colorectal Cancer

AbstractHomeodomain-only protein X (HOPX)-β promoter methylation was recently shown to be frequent in human cancers and was suggested as tumor suppressor gene in esophageal and gastric cancer. The aim of this study was to investigate the mechanistic roles of HOPX-β promoter methylation and its clinical relevance in colorectal cancer (CRC). HOPX-β promoter methylation was assessed in human CRC cell lines and 294 CRC tissues. HOPX mRNA and protein levels were measured in relation to HOPX-β promoter methylation. The effects of forced HOPX expression on tumorigenesis were studied using in vitro and in vivo assays. The association between HOPX-β promoter methylation and clinical relevance of CRC patients was determined. HOPX-β promoter methylation is cancer-specific and frequently found in CRC cell lines and tissues, resulting in the down-regulation of HOPX mRNA and protein levels. In CRC cell lines, forced expression of HOPX suppressed proliferation, invasion, and anchorage-independent growth. DNA microarray analyses suggested critical downstream genes that are associated with cancer cell proliferation, invasion or angiogenesis. In a mouse xenograft model, HOPX inhibited tumorigenesis and angiogenesis. Finally, HOPX-β promoter methylation was associated with worse prognosis of stage III CRC patients (hazard ratio= 1.40, P = .035) and also with poor differentiation (P = .014). In conclusion, HOPX-β promoter methylation is a frequent and cancer-specific event in CRC progression. This epigenetic alteration may have clinical ramifications in the diagnosis and treatment of CRC patients

eIF5 stimulates the CUG initiation of RAN translation of poly-GA dipeptide repeat protein (DPR) in C9orf72 FTLD/ALS

Gotoh S., Mori K., Fujino Y., et al. eIF5 stimulates the CUG initiation of RAN translation of poly-GA dipeptide repeat protein (DPR) in C9orf72 FTLD/ALS. Journal of Biological Chemistry 300, 105703 (2024); https://doi.org/10.1016/j.jbc.2024.105703.Tandem GGGGCC repeat expansion in C9orf72 is a genetic cause of frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). Transcribed repeats are translated into dipeptide repeat proteins via repeat-associated non-AUG (RAN) translation. However, the regulatory mechanism of RAN translation remains unclear. Here, we reveal a GTPase-activating protein, eukaryotic initiation factor 5 (eIF5), which allosterically facilitates the conversion of eIF2-bound GTP into GDP upon start codon recognition, as a novel modifier of C9orf72 RAN translation. Compared to global translation, eIF5, but not its inactive mutants, preferentially stimulates poly-GA RAN translation. RAN translation is increased during integrated stress response, but the stimulatory effect of eIF5 on poly-GA RAN translation was additive to the increase of RAN translation during integrated stress response, with no further increase in phosphorylated eIF2α. Moreover, an alteration of the CUG near cognate codon to CCG or AUG in the poly-GA reading frame abolished the stimulatory effects, indicating that eIF5 primarily acts through the CUG-dependent initiation. Lastly, in a Drosophila model of C9orf72 FTLD/ALS that expresses GGGGCC repeats in the eye, knockdown of endogenous eIF5 by two independent RNAi strains significantly reduced poly-GA expressions, confirming in vivo effect of eIF5 on poly-GA RAN translation. Together, eIF5 stimulates the CUG initiation of poly-GA RAN translation in cellular and Drosophila disease models of C9orf72 FTLD/ALS

Cesium Implant for Tongue Carcinoma with a Thickness of 1.5 cm or More: Cases Successfully Treated with a Modified Manchester System

∙The authors have no financial conflicts of interest. Purpose: Deciding on treatment carcinoma of the tongue when the tumor has a thickness of 1.5 cm or more is difficult. Surgery often requires wide resection and re-construction, leading to considerable functional impairment. A cesium implant is an attractive option, but according to the Manchester System, a two plane implant is needed. Materials and Methods: According to the textbook, a tumor is sandwiched between the needles, which are implanted at the edge of the tumor. This may cause an unnecessarily high dose to the outer surface of the tongue, which sometimes leads to a persistent ulcer. To avoid this complication, we invented a modified implantation method, and applied the method to five consecutive patients. Results: With a minimum follow-up of 2 years, all primary tumors in 5 consecutive patients have been controlled. No complications occurred in soft tissu