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 & Turbulence. The organization has 10766 authors who have published 19140 publications receiving 255696 citations. The organization is also known as: Nagoya Kōgyō Daigaku & Nitech.

Characterization of different-Al-content AlxGa1−xN/GaN heterostructures and high-electron-mobility transistors on sapphire

Abstract: AlxGa1−xN/GaN (0.20⩽x⩽0.52) heterostructures (HSs) were grown on a sapphire substrate by atmospheric pressure metalorganic chemical vapor deposition with good uniformity and two-dimensional-electron-gas (2DEG) mobilities of 936, 1163, 1310, 1274, and 911 cm2/V s for different-Al-contents of 20%, 27%, 34%, 42%, and 52%, respectively. 2DEG mobility increase up to the Al content of 34% and then it slowly decreases for high Al-content AlGaN/GaN HSs. An increase of sheet carrier density with the increase of Al content has been observed. A small hump photoluminescence peak of e2DEG1–h has been observed in both 34% and 42% Al-content AlGaN/GaN heterostructures. High Al-content (52%) heterostructure has exhibited a distinguished e2DEG1–h peak. The increase of surface roughness and granular size of AlGaN/GaN heterostructures with the increase of Al content is due to the increase of lattice mismatch between GaN and AlGaN layers. High-electron-mobility transistors (HEMTs) have been fabricated and characterized using...

Correlation between COVID-19 Morbidity and Mortality Rates in Japan and Local Population Density, Temperature, and Absolute Humidity.

Abstract: This study analyzed the morbidity and mortality rates of the coronavirus disease (COVID-19) pandemic in different prefectures of Japan. Under the constraint that daily maximum confirmed deaths and daily maximum cases should exceed 4 and 10, respectively, 14 prefectures were included, and cofactors affecting the morbidity and mortality rates were evaluated. In particular, the number of confirmed deaths was assessed, excluding cases of nosocomial infections and nursing home patients. The correlations between the morbidity and mortality rates and population density were statistically significant (p-value < 0.05). In addition, the percentage of elderly population was also found to be non-negligible. Among weather parameters, the maximum temperature and absolute humidity averaged over the duration were found to be in modest correlation with the morbidity and mortality rates. Lower morbidity and mortality rates were observed for higher temperature and absolute humidity. Multivariate linear regression considering these factors showed that the adjusted determination coefficient for the confirmed cases was 0.693 in terms of population density, elderly percentage, and maximum absolute humidity (p-value < 0.01). These findings could be useful for intervention planning during future pandemics, including a potential second COVID-19 outbreak.

Enhancement of Donor–Acceptor Pair Emissions in Colloidal AgInS2 Quantum Dots with High Concentrations of Defects

Abstract: We report on mechanisms of highly fluorescent donor–acceptor pair emissions in chalcopyrite AgInS2 quantum dots (QDs). We observed that photoluminescence quantum yields (PL-QYs) and radiative recombination rates strongly depend on the QD size; smaller QDs exhibit higher PL-QYs and higher radiative recombination rates of up to 60% and 106 s –1, respectively. Such characteristics were examined in terms of concentrations of donors and acceptors estimated from PL decay behaviors analyzed by the theory of Thomas and Hopfield. These analyses revealed that concentrations of donors and acceptors are higher for smaller QDs; this significantly enhances radiative recombination rates and PL-QYs in smaller QDs. In turn, higher concentrations of donors and acceptors in smaller QDs can be attributed to the use of lower synthesis temperatures, which increase the population of donor–acceptor-type lattice defects.

Salsolinol is a putative endogenous neuro-intermediate lobe prolactin-releasing factor.

Abstract: The isolation and identification of a prolactin-releasing factor (PRF) from the neuro-intermediate lobe of the pituitary gland has been pursued for over a decade. Using high-pressure liquid chromatography with electrochemical detection (HPLC-ECD) and gas chromatography/mass spectrometry (GC/MS) (R)-salsolinol (SAL) (a dopamine-related stereo-specific tetrahydroisoquinoline) was found to be present in neuro-intermediate lobe as well as median eminence extracts of male, intact-, and ovariectomized female rats. Moreover, analysis of SAL concentrations in neuro-intermediate lobe revealed parallel increases with plasma prolactin in lactating rats exposed to a brief (10 min) suckling stimulus following 4-h separation. SAL appears to be a selective and potent stimulator of prolactin secretion in vivo and it was without effect on the secretion of other pituitary hormones. We have also found that SAL can elevate prolactin release, although to a lesser extent, in pituitary cell cultures as well as in hypophysectomized rats bearing anterior lobe transplants under the kidney capsule. Lack of interference of SAL with [3H]-spiperone binding to AP homogenates indicates that SAL does not act at the dopamine D2 receptor. Moreover, [3H]-SAL binds specifically to homogenate of AL as well as neuro-intermediate lobe obtained from lactating rats. Taken together, our data clearly suggest that SAL is synthesized in situ and this compound can play a role in the regulation of pituitary prolactin secretion.

Reactivity of hydroperoxide bound to a mononuclear non-heme iron site.

Abstract: The first isolation and spectroscopic characterization of the mononuclear hydroperoxo−iron(III) complex [Fe(H2bppa)(OOH)]2+ (2) and the stoichiometric oxidation of substrates by the mononuclear iron−oxo intermediate generated by its decomposition have been described. The purple species 2 obtained from reaction of [Fe(H2bppa)(HCOO)](ClO4)2 with H2O2 in acetone at −50 °C gave characteristic UV−vis (λmax = 568 nm, e = 1200 M-1 cm-1), ESR (g = 7.54, 5.78, and 4.25, S = 5/2), and ESI mass spectra (m/z 288.5 corresponding to the ion, [Fe(bppa)(OOH)]2+), which revealed that 2 is a high-spin mononuclear iron(III) complex with a hydroperoxide in an end-on fashion. The resonance Raman spectrum of 2 in d6-acetone revealed two intense bands at 621 and 830 cm-1, which shifted to 599 and 813 cm-1, respectively, when reacted with 18O-labeled H2O2. Reactions of the isolated (bppa)FeIII−OOH (2) with various substrates (single turnover oxidations) exhibited that the iron−oxo intermediate generated by decomposition of 2 is ...