Nanostructure-enhanced infrared spectroscopy

While infrared spectroscopy is a powerful technique that provides molecular information such as chemical constituents and chemical structures of analytes, it suffers from low absorption cross-section resulting in low sensitivity and poor signal-to-noise or signal-to-background ratios. Surface-enhanced infrared absorption (SEIRA) spectroscopy, which is supported by nanometer scale structures, is a promising technology to overcome these problems in conventional infrared (IR) spectroscopy and enhances IR signals using the field enhancement properties of surface plasmon resonance. Recently resonant SEIRA technique was proposed, and signal enhancement factor was significantly improved. In this review, we present an overview of the recent progresses on resonant SEIRA technologies including nanoantenna- and metamaterial-based SEIRA, and also SEIRA techniques with nanoimaging capabilities

A weighted competitive learning method extracting skeleton pattern for Japanese Kanji characters

金沢大学理工研究域　電子情報学系A weighted competitive learning (WCL) method was proposed by authors for extracting skeleton patterns from digit and alphabet characters. The extracted pattern is essential in character recognition. It can satisfy the following important requirements. (a) Insensitive to irregular edge lines. (b) Non-structure patterns are not extracted. (c) Insensitive to non-uniform line width. (d) Line information should be held even though the line width widely changes in a character. In this paper, the previous WCL method is improved for application to more complicated characters, such as Japanese Kanji characters. Furthermore, a PDP model, implements the WCL method, is provided

A weighted competitive learning method extracting skeleton pattern for Japanese Kanji characters

金沢大学理工研究域　電子情報学系A weighted competitive learning (WCL) method was proposed by authors for extracting skeleton patterns from digit and alphabet characters. The extracted pattern is essential in character recognition. It can satisfy the following important requirements. (a) Insensitive to irregular edge lines. (b) Non-structure patterns are not extracted. (c) Insensitive to non-uniform line width. (d) Line information should be held even though the line width widely changes in a character. In this paper, the previous WCL method is improved for application to more complicated characters, such as Japanese Kanji characters. Furthermore, a PDP model, implements the WCL method, is provided

Highly Stable Polymer Coating on Silver Nanoparticles for Efficient Plasmonic Enhancement of Fluorescence

Surface coating of plasmonic nanoparticles is of huge importance to suppress fluorescence quenching in plasmon-enhanced fluorescence sensing. Herein, a one-pot method for synthesizing polymer-coated silver nanoparticles was developed using a functional polymer conjugated with disulfide-containing anchoring groups. The disulfides played a crucial role in covalently bonding polymers to the surface of the silver nanoparticles. The covalent bond enabled the polymer layer to form a long-term stable coating on the silver nanoparticles. The polymer layer coated was adequately thin to efficiently achieve plasmonic enhancement of fluorescence and also thick enough to effectively suppress quenching of fluorescence, achieving a huge net enhancement of fluorescence. The polymer-coated plasmonic nanoparticles are a promising platform for demonstrating highly sensitive biosensing for medical diagnostics

Ultra-broadband surface-normal coherent optical receiver with nanometallic polarizers

A coherent receiver that can demodulate high-speed in-phase and quadrature signals of light is an essential component for optical communication, interconnects, imaging, and computing. Conventional waveguide-based coherent receivers, however, exhibit large footprints, difficulty in coupling a large number of spatial channels efficiently, and limited operating bandwidth imposed by the waveguide-based optical hybrid. Here, we present a surface-normal coherent receiver with nanometallic-grating-based polarizers integrated directly on top of photodetectors without the need for an optical hybrid circuit. Using a fabricated device with the active section occupying a 70-{\mu}m-square footprint, we demonstrate demodulation of high-speed (up to 64 Gbaud) coherent signals in various formats. Moreover, ultra-broadband operation from 1260 nm to 1630 nm is demonstrated, thanks to the wavelength-insensitive nanometallic polarizers. To our knowledge, this is the first demonstration of a surface-normal homodyne optical receiver, which can easily be scaled to a compact two-dimensional arrayed device to receive highly parallelized coherent signals.Comment: 23 pages, 4 figures (main manuscript) + 4 pages, 2 figures (supporting info

Development and prevention of advanced diabetic nephropathy in RAGE-overexpressing mice

金沢大学医薬保健研究域医学系Vascular complications arising from multiple environmental and genetic factors are responsible for many of the disabilities and short life expectancy associated with diabetes mellitus. Here we provide the first direct in vivo evidence that interactions between advanced glycation end products (AGEs; nonenzymatically glycosylated protein derivatives formed during prolonged hyperglycemic exposure) and their receptor, RAGE, lead to diabetic vascular derangement. We created transgenic mice that overexpress human RAGE in vascular cells and crossbred them with another transgenic line that develops insulin-dependent diabetes shortly after birth. The resultant double transgenic mice exhibited increased hemoglobin A1c and serum AGE levels, as did the diabetic controls. The double transgenic mice demonstrated enlargement of the kidney, glomerular hypertrophy, increased albuminuria, mesangial expansion, advanced glomerulosclerosis, and increased serum creatinine compared with diabetic littermates lacking the RAGE transgene. To our knowledge, the development of this double transgenic mouse provides the first animal model that exhibits the renal changes seen in humans. Furthermore, the phenotypes of advanced diabetic nephropathy were prevented by administering an AGE inhibitor, (±)-2-isopropylidenehydrazono-4-oxo-thiazolidin-5-ylacetanilide (OPB-9195), thus establishing the AGE-RAGE system as a promising target for overcoming this aspect of diabetic pathogenesis

The role of AGE-Rage system in the development of diabetic nephropathy in vivo

金沢大学大学院医学部医学系研究科Vascular complications are what eventually threaten the lives of diabetic patients. Here we show direct in vivo evidence that the interaction between advanced glycation end products (AGE), the formation of which is accelerated during prolonged hyperglycemic exposure, and a cell surface receptor for AGE (RAGE) is the major cause of such complications. We created transgenic mice that overexpress human RAGE in vascular cells and crossbred them with another transgenic line which develops insulin-dependent diabetes early after birth. The resultant double transgenic mice exhibited accelerated kidney changes compared with single transgenic littermates, and the nephropathy was ameliorated by an inhibitor of AGE formation. The AGE–RAGE system will thus be a promising target for overcoming diabetic complications

Role of FBXW7 in the quiescence of gefitinib-resistant lung cancer stem cells in EGFR-mutant non-small cell lung cancer

Several recent studies suggest that cancer stem cells (CSCs) are involved in intrinsic resistance to cancer treatment. Maintenance of quiescence is crucial for establishing resistance of CSCs to cancer therapeutics. F-box/WD repeat-containing protein 7 (FBXW7) is a ubiquitin ligase that regulates quiescence by targeting the c-MYC protein for ubiquitination. We previously reported that gefitinib-resistant persisters (GRPs) in EGFR-mutant non-small cell lung cancer (NSCLC) cells highly expressed octamer-binding transcription factor 4 (Oct-4) as well as the lung CSC marker CD133, and they exhibited distinctive features of the CSC phenotype. However, the role of FBXW7 in lung CSCs and their resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors in NSCLC is not fully understood. In this study, we developed GRPs from the two NSCLC cell lines PC9 and HCC827, which express an EGFR exon 19 deletion mutation, by treatment with a high concentration of gefitinib. The GRPs from both PC9 and HCC827 cells expressed high levels of CD133 and FBXW7, but low levels of c-MYC. Cell cycle analysis demonstrated that the majority of GRPs existed in the G0/G1 phase. Knockdown of the FBXW7 gene significantly reduced the cell number of CD133-positive GRPs and reversed the cell population in the G0/G1-phase. We also found that FBXW7 expression in CD133-positive cells was increased and c-MYC expression was decreased in gefitinib-resistant tumors of PC9 cells in mice and in 9 out of 14 tumor specimens from EGFR-mutant NSCLC patients with acquired resistance to gefitinib. These findings suggest that FBXW7 plays a pivotal role in the maintenance of quiescence in gefitinib-resistant lung CSCs in EGFR mutation-positive NSCLC