Nagoya Institute of Technology

About: Nagoya Institute of Technology is a education organization based out in Nagoya, Japan. It is known for research contribution in the topics: Thin film & Catalysis. The organization has 10766 authors who have published 19140 publications receiving 255696 citations. The organization is also known as: Nagoya Kōgyō Daigaku & Nitech.

N-methylated tetrahydroisoquinolines as dopaminergic neurotoxins

Abstract: N-Methylation of dopamine-derived 6,7-dihydroxyisoquinolines produces compounds whose chemical structures are similar to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). N-Methylation of 1,2,3,4-tetrahydroisoquinoline was proved by in vitro experiments using human brain homogenate as an enzyme source. By in vivo microdialysis in rat brains, N-methylation of 1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinolines (salsolinols) was also demonstrated. Among the brain regions examined, the activity of N-methylation was the highest in the substantia nigra. N-methyl-1,2,3,4-tetrahydroisoquinoline was oxidized to produce N-methyl-isoquinolinium ion by type A and type B monoamine oxidase prepared from human brain synaptosomal mitochondria. The structure of the oxidized isoquinoline is similar to that of 1-methyl-4-phenylpyridinium ion, a potent dopaminergic neurotoxin. These results indicate that these isoquinolines produced in or around dopamine neurons are N-methylated especially in substantia nigra and may be further oxidized by monoamine oxidase to produce ions. This biosynthesis pathway is quite similar to the oxidative synthesis of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. N-Methylation and oxidation of isoquinolines or other endogenous compounds may be involved in the pathogenesis of Parkinson's disease.

ZnO nanorods prepared via ablation of Zn with millisecond laser in liquid media

Abstract: ZnO nanomaterials with controlled size, shape and surface chemistry are required for applications in diverse areas, such as optoelectronics, photocatalysis, biomedicine and so on. Here, we report on ZnO nanostructures with rod-like and spherical shapes prepared via laser ablation in liquid using a laser with millisecond-long pulses. By changing laser parameters (such as pulse width and peak power), the size or aspect ratio of such nanostructures could be tuned. The surface chemistry and defects of the products were also strongly affected by applied laser conditions. The preparation of different structures is explained by the intense heating of liquid media caused by millisecond-long pulses and secondary irradiation of already-formed nanostructures.

Transfer of noncovalent chiral information along an optically inactive helical peptide chain: allosteric control of asymmetry of the C-terminal site by external molecule that binds to the N-terminal site.

Abstract: This study aims at demonstrating end-to-end transfer of noncovalent chiral information along a peptide chain. The domino-type induction of helical sense is proven by using achiral peptides 1-m of bis-chromophoric sequence with different chain lengths: H-(Aib-ΔZPhe)m-(Aib-ΔZBip)2-Aib-OCH3 [m = 2, 4, and 6; Aib = α-aminoisobutyric acid; ΔZPhe = (Z)-α,β-didehydrophenylalanine; ΔZBip = (Z)-β-(4,4′-biphenyl)-α,β-didehydroalanine]. They all showed the tendency to adopt a 310-helix. Whereas peptide 1-m originally shows no circular dichroism (CD) signals, marked CD signals were induced at around 270−320 nm based on both the β-aryl didehydroresidues by chiral Boc-proline (Boc = tert-butoxycarbonyl). The observed CD spectra were interpreted on the basis of the exciton chirality method and theoretical CD simulation of several helical conformations that were energy-minimized. The experimental and theoretical CD analysis reveals that Boc-l-proline induces the preference for a right-handed helicity in the whole chain o...

Structural evolution of calcite at high temperatures: phase V unveiled.

Abstract: The calcite form of calcium carbonate CaCO3 undergoes a reversible phase transition between Rc and Rm at ~1240 K under a CO2 atmosphere of ~0.4 MPa. The joint probability density function obtained from the single-crystal X-ray diffraction data revealed that the oxygen triangles of the CO3 group in the high temperature form (Phase V) do not sit still at specified positions in the space group Rm, but migrate along the undulated circular orbital about carbon. The present study also shows how the room temperature form (Phase I) develops into Phase V through an intermediate form (Phase IV) in the temperature range between ~985 K and ~1240 K.