Hiroyuki Watanabe

Various nitrogen-doped carbon materials were prepared via treatments of an activated carbon (AC) with ammonia and hydrogen peroxide, and their catalytic performance was tested for aerobic oxidation of several alcohols in ethanol. The amount and nature of doped nitrogen-species were examined by X-ray photoelectron spectroscopy to discuss the genesis of active species by nitrogen doping. The nitrogen-doped AC catalysts are active for the oxidation of such alcohols as benzyl alcohol, cinnamyl alcoh

We report on near-field Raman spectra of a single nanocrystal of DNA-base adenine molecules using a silver-layer-coated apertureless probe tip of an atomic force microscope. The tip-enhanced near-field Raman spectrum shows eight Raman bands that are assigned to the normal modes of adenine molecules based on the density-functional theory (DFT) calculations. The vibrational frequencies of several bands are observed to have unambiguously shifted to the values of the corresponding bands, observed us

We have constructed a dual-probe scanning tunneling microscope (D-STM). We used multiwall carbon nanotubes [(NT), diameter: ∼10 nm] as STM probes. The D-STM allows us to elucidate the electric property of a sample with a spatial resolution of ∼1 nm. Using this system, we have measured the current–voltage curves of a single NT ring as a transistor. The curves show the possibility of nanometer-scale electronic circuits composed of NT devices.

The formation of β-amyloid (Aβ) plaques is a critical neurodegenerative change in Alzheimer disease (AD). We designed and synthesized novel boron dipyrromethane (BODIPY)-based Aβ probes (BAPs) and evaluated their utility for near-infrared fluorescence imaging of Aβ plaques in the brain. In binding experiments in vitro, BAPs showed high affinity for synthetic Aβ aggregates (Kd = 18-149 nM). Furthermore, BAPs clearly stained Aβ plaques in sections of Tg2576 mice. In mouse brain tissue, BAPs showed

Deposits of β-amyloid (Aβ) and α-synuclein (α-syn) are the hallmark of Alzheimer's disease (AD) and Parkinson's disease (PD), respectively. The detection of these protein aggregates with fluorescent probes is particularly of interest for preclinical studies using fluorescence microscopy on human brain tissue. In this study, we newly designed and synthesized three push-pull benzothiazole (PP-BTA) derivatives as fluorescent probes for detection of Aβ and α-syn aggregates. Fluorescence intensity of

In vivo fluorescence imaging of β-amyloid (Aβ) plaques in the brain is expected to be used as a new method for detecting Alzheimer's disease (AD). We synthesized novel push-pull dimethylaminothiophenyl (DTM) derivatives and evaluated their utility as in vivo fluorescence imaging probes targeting Aβ plaques. As a result, we found that DTM-2 is a promising fluorescent probe for Aβ plaques in the AD brains.

Pironetin (1) and demethylpironetin (2) are potent inhibitors of tubulin assembly. They arrested the mammalian cell cycle in M-phase and showed antitumor activity against a murine tumor cell line, P388 leukemia, transplanted in mice. To investigate the chemical and biological properties of 1, we synthesized several derivatives and investigated the structure-activity relationships. All synthesized derivatives decreased biological activities, such as inhibition of cell cycle progression, and disru