Akira Oda

Circadian rhythms are the daily oscillations of multiple biological processes regulated by an endogenous clock. The Period2 gene is essential in controlling the circadian rhythm and plays an important role in tumor suppression. We examined whether the overexpression of the mouse Period2 gene (mPer2) in cultured tumor cells from human tissues inhibits cell growth, using the recombinant adenovirus vector AdmPer2. The overexpression of mPer2 in human pancreatic cancer cells (Panc1, Aspc1) reduced c

The key reactive sites in the selective catalytic reduction (SCR) of NO using ammonia (NH3–SCR) are the Cu(II)/Cu(I) ammine complexes encapsulated within zeolite catalysts. The reaction intermediate in the important CuI → CuII reoxidation step has been proposed as the dicopper species. However, obtaining the definitive spectroscopic probe for the dicopper intermediate under NH3–SCR remains a quite challenging subject. Here we report spectroscopic evidence of the efficient generation of the dicop

In its element: Zn(2+) at the M7 site of MFI-type zeolites activates H(2), via ZnH and OH species, and leads to Zn(0) species. The Zn(0) species returns to its original state, a Zn(2+) ion, upon evacuation of the zeolite at 873 K (see picture). The formation of the Zn(0) species is supported by DFT calculations.

We present clear IR and density functional theory (DFT) evidence demonstrating that the electron-accepting nature of Zn2+ ion exchanged in MFI-type zeolite (ZnMFI) plays a dominant role in CH4 activation. The IR study revealed that the heterolytic dissociation of CH4 takes place on the Zn2+ ion exchanged in MFI under a CH4 atmosphere even near room temperature, whereas a similar reaction scarcely occurred on Mg2+ ion exchanged in MFI, although the ionic radius and charge of Mg2+ are almost the s

For the first time, the paramagnetic Zn(+) species was prepared successfully by the excitation with ultraviolet light in the region ascribed to the absorption band resulting from the 4s-4p transition of an atomic Zn(0) species encapsulated in an MFI-type zeolite. The formed species gives a specific electron spin resonance band at g = 1.998 and also peculiar absorption bands around 38,000 and 32,500 cm(-1) which originate from 4s-4p transitions due to the Zn(+) species with paramagnetic nature th

The NaCaA-85 zeolite sample which works as an efficient adsorbent for CO₂at RT and in low pressure range was found and its specificity is nicely explained by the model composed of CO₂pinned by two types of Ca²⁺ions through far-IR and DFT studies.

Oxygenase reactivity toward selective partial oxidation of CH₄ to CH₃OH requires an atomic oxygen-radical bound to metal (M-O^•: oxyl intermediate) that is capable of abstracting an H atom from the significantly strong C-H bond in CH₄. Because such a reaction is frequently observed in metal-doped zeolites, it has been recognized that the zeolite provides an environment that stabilizes the M-O^• intermediate. However, no experimental data of M-

Compared with mercury, the existence of [Zn2](2+) species is rare. We succeeded in preparing a stable [Zn2](2+) species by utilizing an MFI-type zeolite as a nano-reaction pot, which was confirmed using XAFS spectroscopy: the bands at R = 2.35 Å due to the Zn(+)-Zn(+) scattering and at 9660.7 eV due to the 1s-σ* (the anti-bonding orbital comprised of the 4s-4s orbital) transition of the [Zn2](2+) species. This species also gives the characteristic band around 42 000 cm(-1) due to its σ-σ* transi

Cholinergic neurons in the CNS are involved in synaptic plasticity and cognition. Both muscarinic and nicotinic acetylcholine receptors (nAChRs) influence plasticity and cognitive function. The mechanism underlying nAChR-induced plasticity, however, has remained elusive. Here, we demonstrate morphological changes in dendritic spines following activation of α4β2* nAChRs, which are expressed on glutamatergic pre-synaptic termini of cultured hippocampal neurons. Exposure of the neurons to nicotine

We successfully synthesized a Fe/ZSM-5 catalyst enabling conversion of methane to C1 oxygenates in record yields, and demonstrated that the fraction of the single Fe cation, as well as the Al distribution, are the powerful activity descriptors.

Hydrogenation of toluene (TOL) to methylcyclohexane (MCH) is one of the hydrogen carrier systems desired for social integration. Supported Pt nanoparticle catalysts are effective for this application. However, Pt is rare, expensive, and in short supply, limiting its practical applications. Therefore, the key issue for TOL hydrogenation is how to substantially reduce the amount of Pt required for the catalyst. Because a specific ensemble of Pt atoms, that is dominantly formed on the surface of th

In this work, we used both experimental and density functional theory (DFT) calculation methods to examine the mechanism of CH4 activation taking place on the Zn2+ ion exchanged MFI-type zeolite (ZnMFI). The heterolytic dissociation of CH4 on ZnMFI around 300 K was observed experimentally, causing the appearance of IR bands at 3615, 2930, and 2892 cm–1. The first band can be assigned to the OH stretching vibration associated with the formation of the Brønsted acid site and the latter to the C–H

Although a terminal oxyl species bound to certain metal ions is believed to be the intermediate for various oxidation reactions, such as O-O bond generation in photosystem II (PSII), such systems have not been characterized. Herein, we report a stable Zn^II -oxyl species induced by an MFI-type zeolite lattice and its reversible reactivity with O₂ at room temperature. Its intriguing characteristics were confirmed by in situ spectroscopic studies in combination with quantum-ch

We successfully developed a Pt single atom alloyed sub-1 nm thick Fe overlayer on Cu nanoparticles capable of catalyzing MCH dehydrogenation with the H 2 -evolution rate per Pt mass at least 133 times higher than that of state-of-the-art catalysts.