Explore the vast range of titles available.

Knowledge of carbon isotope fractionation is needed in order to discuss the formation and dissociation of naturally occurring CO2 hydrates. We investigated carbon isotope fractionation during CO2 hydrate formation and measured the three-phase equilibria of 12CO2–H2O and 13CO2–H2O systems. From a crystal structure viewpoint, the difference in the Raman spectra of hydrate-bound 12CO2 and 13CO2 was revealed, although their unit cell size was similar. The δ13C of hydrate-bound CO2 was lower than that of the residual CO2 (1.0–1.5‰) in a formation temperature ranging between 226 K and 278 K. The results show that the small difference between equilibrium pressures of ~0.01 MPa in 12CO2 and 13CO2 hydrates causes carbon isotope fractionation of ~1‰. However, the difference between equilibrium pressures in the 12CO2–H2O and 13CO2–H2O systems was smaller than the standard uncertainties of measurement; more accurate pressure measurement is required for quantitative discussion.

Organic–inorganic perovskite materials with a bulk structure MAPbX 3 (MA: methylamine, X: halogen) have attracted much attention in various applications such as solar cells, photodiodes, and radiation detectors. Herein, we synthesized (CH 3 NH 3 )Pb 1- x Mn x Cl 3 (or Mn-doped MAPbCl 3 ) crystals by inverse temperature crystallization method to develop scintillator materials and evaluated their photoluminescence (PL) and scintillation properties systematically. The Mn-doped MAPbCl 3 crystals showed a sharp emission peak at approximately 410–430 nm with short decay times on the order of nanoseconds and a broad peak at approximately 600 nm with a long decay time on the order of milliseconds in PL and scintillation. Furthermore, pulse height spectra of the Mn-doped MAPbCl 3 crystals with a shaping time of 1 µs were measured, and the obtained scintillation light yields were estimated to be 66 ( x  = 1), 82 ( x  = 5), and 67 ( x  = 10) photons/5.5 MeV-α. Moreover, afterglow levels of the Mn-doped MAPbCl 3 crystals were found to be 161 ( x  = 1), 264 ( x  = 5) and 170 ( x  = 10) ppm, which were comparable to a previously reported afterglow level of Tl-doped CsI.

We evaluated the photoluminescence (PL), scintillation, and dosimetric properties of Ce–doped Mg 2 SiO 4 single crystals. As the PL and optically-stimulated luminescence (OSL) properties, the Ce–doped Mg 2 SiO 4 showed the emission from 5 d to 4 f transitions of Ce 3+ . In the scintillation and thermally-stimulated luminescence (TSL) properties, two emission peaks due to Ce 3+ and defect centers were observed. The Ce–doped Mg 2 SiO 4 showed OSL by stimulating at 600 nm and TSL by heating at 50, 160, 195, and 370 °C. In OSL, linearly proportional responses were confirmed from 10 mGy for the 0.5 and 1% Ce–doped samples to 100 mGy for the 0.1% Ce–doped sample. In TSL, the undoped and Ce–doped samples had the linearity response from 100 to 0.01 mGy, respectively.

45SrO–5Al 2 O 3 –50SiO 2 glasses doped with various concentrations of Ce (0, 0.01, 0.05, 0.1, and 0.5 mol%) were synthesized by the conventional melt-quenching methods, and the basic optical, scintillation, and thermally stimulated luminescence (TSL) properties were investigated. Regarding the optical properties, under 340 nm excitation, the emission peak around 420 nm of the Ce-doped glasses was confirmed. The emission would be due to the 5d → 4f transitions of Ce 3+ . In contrast, the scintillation spectra of all the glasses showed two emission peaks around 350 and 400 nm, and the origins would be some defects or impurity ions included in the host glass. By 241 Am 5.5 MeV α-ray irradiation, the non-doped glass showed the highest light yield, which was 69 photons/MeV with a typical error of ± 10%. As the TSL properties, the TSL intensity of 0.01% Ce-doped glass was the highest among the prepared glasses, and a linear response to the irradiation dose was confirmed in the dose range of 0.01–1000 mGy.

Previous clinical and experimental studies have indicated that magnesium may prevent vascular calcification (VC), but mechanistic characterization has not been reported. This study investigated the influence of increasing magnesium concentrations on VC in a rat aortic tissue culture model. Aortic segments from male Sprague-Dawley rats were incubated in serum-supplemented high-phosphate medium for 10 days. The magnesium concentration in this medium was increased to demonstrate its role in preventing VC, which was assessed by imaging and spectroscopy. The mineral composition of the calcification was analyzed using Fourier transform infrared (FTIR) spectroscopic imaging, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) mapping. Magnesium supplementation of high-phosphate medium dose-dependently suppressed VC (quantified as aortic calcium content), and almost ablated it at 2.4 mm magnesium. The FTIR images and SEM-EDX maps indicated that the distribution of phosphate (as hydroxyapatite), phosphorus and Mg corresponded with calcium content in the aortic ring and VC. The inhibitory effect of magnesium supplementation on VC was partially reduced by 2-aminoethoxy-diphenylborate, an inhibitor of TRPM7. Furthermore, phosphate transporter-1 (Pit-1) protein expression was increased in tissues cultured in HP medium and was gradually-and dose dependently-decreased by magnesium. We conclude that a mechanism involving TRPM7 and Pit-1 underpins the magnesium-mediated reversal of high-phosphate-associated VC.

x % Yb-, 0.5% Er-co-doped Y 2 O 3 transparent ceramics ( x  = 0, 0.1, 0.5, 1.0, 5.0 and 10) were prepared by the spark plasma sintering, and then we evaluated the effect of Yb doping on optical and upconversion (UC) photoluminescence (PL) properties. Under an excitation at 380 nm, the sharp emission peaks appeared around 550 and 660 nm, and the quantum yield was approximately 2%. The PL decay curves monitoring around 550 nm were fitted by a single exponential decay function. The decay time constants were 0.03–0.11 ms, and the values were typical for the 4f → 4f transitions of Er 3+ . Regarding the UC PL properties, the sharp UC emission peaks around 550 and 660 nm were observed, and the UC emission intensity of 5.0% Yb-, 0.5% Er-co-doped Y 2 O 3 transparent ceramic sample was the highest among the prepared samples. With increasing x , the chromaticity of UC emission color was tuned from green to red region. Regarding the UC PL decay curves, the rise time became slower as increasing x . This behavior is one of the evidence of energy transfer from Yb 3+ to Er 3+ .

Photoluminescence and scintillation properties of undoped and Eu-doped 20CsCl–20BaCl 2 –60ZnCl 2 (CBZ) glasses were investigated. The Eu-doped CBZ glasses indicated photoluminescence and scintillation with two emission peaks around 420 and 610 nm due to the 5d–4f transition of Eu 2+ and the 4f–4f transition of Eu 3+ , respectively. The undoped CBZ glass showed emission peaking around 500 nm under excitation at 130 nm, and the possible emission origin would be self-trapped excitons (STEs). From measurements at low temperatures, the 0.3% Eu-doped CBZ glass shows an emission peak around 420 and 450–700 nm, and they would be considered to be the 5d–4f transition of Eu 2+ and STEs, respectively.

Li-codoped MgF 2 :Tb ceramics with different Li concentrations (0.01, 0.1, 1, and 3 mol%) were prepared by the spark plasma sintering method, and photoluminescence (PL), scintillation, and dosimetric properties were investigated. Sharp peaks due to 4-4 f transitions of Tb 3+ ion were observed in all of PL, scintillation, and thermally-stimulated luminescence (TSL). TSL glow curves confirmed that the TSL intensity was increased by Li-codoping without an increase of QY values. Especially, the TSL intensity was the highest in 1% Li-codoped MgF 2 :Tb, which was approximately 2.2 times larger than that of MgF 2 doped with only Tb. Moreover, It was confirmed that the TSL responses of the 0.01, 0.1 and 1% Li-codoped MgF 2 :Tb ceramics were very sensitive to irradiation dose and showed a good linearity from 0.01 to 1000 mGy.

This study examined the association between the use of social networking sites (SNS), perceived social support (PSS), and life satisfaction (LS), focusing on the mediating effect of PSS on the association between SNS use and LS. To this end, we used data ( N = 15,574) obtained from a population-based, nationwide internet survey conducted in Japan. First, we confirmed that the number of SNS friends was positively associated with life satisfaction for all age groups: young (15–29 years), middle-aged (30–59 years), and old (60–86 years). However, the association was mixed if there were 100 or more SNS friends. Second, our structural equation modeling analysis underscored the mediating effect of PSS on the association between the number of SNS friends and LS for all age groups. Specifically, PSS mediated 36.5% (standard error [SE]: 8.6%), 39.8% (SE: 6.3%), and 40.3% (SE: 11.4%) of the association for the young, middle-aged, and old groups, respectively, if we defined SNS use as having 10 or more SNS friends. The mediating effect of PSS consistently contributed to the positive association between SNS use and LS regardless of the number of SNS friends, suggesting that SNS use has the potential to enhance subjective well-being via its positive impact on PSS.

Introduction Introducing a primary care physician ( Kakaritsuke-I : KI) system to improve the efficiency of the health care system has been controversial in Japan. This study aimed to determine the relevance of KI to an individual’s health behavioral intentions. Methods We used data from a nationwide, population-based internet survey ( N  = 5,234) to conduct a cross-sectional regression analysis. Additionally, we used a propensity score matching method to mitigate the potential endogenous biases inherent in the decision to have a KI. Results KI was positively associated with various behavioral intentions. For example, the probabilities of intending to eat a well-balanced diet and engaging in moderate exercise were 12.8 (95% confidence interval [CI]:9.5–16.1) percentage points and 7.2 (95% CI: 3.9–10.4) percentage points higher, respectively, among those with a KI than among those without a KI. A KI equally increased the likelihood of getting vaccinated against coronavirus (in November 2021) by 7.5 (95% CI: 5.2–9.8) percentage points. Conclusions Although further analysis is needed to examine the effect of KI on health, the results of this study suggest the potential benefits of policy measures to promote the KI system.