To reveal the in planta behaviour of caesium (Cs), the stable isotope 133Cs was administered into 3-year-old Cryptomeria japonica seedlings by the application of 133CsCl aqueous solution to the bark ...surface. The administered 133Cs was quantified by ICP-MS measurements, which showed transportation of 133Cs in an ascending direction in the stem. Distribution of 133Cs was visualized using freeze-fixed C. japonica woody stem samples and cryo-time-of-flight secondary ion mass spectrometry/scanning electron microscopy (cryo-TOF-SIMS/SEM) analysis. Cryo-TOF-SIMS/SEM visualization suggested that 133Cs was rapidly transported radially by ray parenchyma cells followed by axial transportation by pith and axial parenchyma cells. Adsorption experiments using powdered C. japonica wood samples and X-ray absorption fine structure (XAFS) analysis suggested that 133Cs was in the hydrated state following its deposition into tracheid cell walls.
Display omitted
•133Cs was administered into 3-year-old specimens of Cryptomeria japonica (Japanese cedar) via their bark or roots.•133Cs distribution was visualized by cryo-TOF-SIMS/SEM.•After the contamination of the outer bark, 133Cs permeated into the inner bark.•133Cs was transported by ray parenchyma cells, pith, and axial parenchyma cells.•The chemical form of 133Cs adsorbed onto powdered wood samples was assumedly the hydrated state.
Imprisoned palladium: A unique approach is developed to incarcerate metal clusters with strictly controlled n values within hollow silica nanoparticles. A Pd12L24 spherical complex is used as a ...template for the hollow silica synthesis. The incarcerated Pd12L24 core is calcinated to give (PdO)n oxide clusters and subsequently reduced to Pdn metal clusters within the protective hollow silica.
Recently, we experienced an outbreak of acute hepatitis A virus (HAV) infection between 2018 and 2020. Herein, we describe this male-dominant HAV infection outbreak observed among non-human ...immunodeficiency virus (HIV)-infected persons in the northern part of Tokyo, Japan. Clinical information was collected from patient interviews and from medical record descriptions. In the present study, 21 patients were retrospectively analyzed. A total of 90.4 and 33.3% of patients were males, and men who have sex with men (MSM), respectively. The total bilirubin levels and platelet counts tended to be lower in the MSM group than in the non-MSM group. C-reactive protein (CRP) levels tended to be higher in acute liver failure (ALF) patients than in non-ALF patients. Prolonged cholestasis was observed in one patient (4.8%). We also found that 18 HAV isolates belonged to HAV subgenotype IA/subgroup 13 (S13), which clustered with the HAV isolate (KX151459) that was derived from an outbreak of HAV infection among MSM in Taiwan in 2015. Our results suggest that the application of antivirals against HAV, as well as HAV vaccines, would be useful for the treatment and prevention of severe HAV infection.
Recent studies have revealed the unique virological characteristics of Omicron, particularly those of its spike protein, such as less cleavage efficacy in cells, reduced ACE2 binding affinity, and ...poor fusogenicity. However, it remains unclear which mutation(s) determine these three virological characteristics of Omicron spike. Here, we show that these characteristics of the Omicron spike protein are determined by its receptor-binding domain. Of interest, molecular phylogenetic analysis revealed that acquisition of the spike S375F mutation was closely associated with the explosive spread of Omicron in the human population. We further elucidated that the F375 residue forms an interprotomer pi-pi interaction with the H505 residue of another protomer in the spike trimer, conferring the attenuated cleavage efficiency and fusogenicity of Omicron spike. Our data shed light on the evolutionary events underlying the emergence of Omicron at the molecular level.
Display omitted
•Omicron spike receptor-binding domain determines virological characteristics•Spike S375F mutation results in the poor spike cleavage and fusogenicity in Omicron•Acquisition of the spike S375F mutation triggered the explosive spread of Omicron•F375-H505-mediated π-π interaction in the spike determines the phenotype of Omicron
Molecular biology; Virology
Abstract
There were five epidemic waves of coronavirus disease 2019 in Japan between 2020 and 2021. It remains unclear how the domestic waves arose and abated. To better understand this, we analyzed ...the pangenomic sequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and characterized the molecular epidemiological features of the five epidemic waves in Japan. In this study, we performed deep sequencing to determine the pangenomic SARS-CoV-2 sequences of 1,286 samples collected in two cities far from each other, Tokyo Metropolis and Nagoya. Then, the spatiotemporal genetic changes of the obtained sequences were compared with the sequences available in the Global Initiative on Sharing All Influenza Data (GISAID) database. A total of 873 genotypes carrying different sets of mutations were identified in the five epidemic waves. Phylogenetic analysis demonstrated that sharp displacements of lineages and genotypes occurred between consecutive waves over the 2 years. In addition, a wide variety of genotypes were observed in the early half of each wave, whereas a few genotypes were detected across Japan during an entire wave. Phylogenetically, putative descendant genotypes observed late in each wave displayed regional clustering and evolution in Japan. The genetic diversity of SARS-CoV-2 displayed uneven dynamics during each epidemic wave in Japan. Our findings provide an important molecular epidemiological basis to aid in controlling future SARS-CoV-2 epidemics.
Abstract
Artificial photosynthesis is a desirable critical technology for the conversion of CO
2
and H
2
O, which are abundant raw materials, into fuels and chemical feedstocks. Similar to plant ...photosynthesis, artificial photosynthesis can produce CO, CH
3
OH, CH
4
, and preferably higher hydrocarbons from CO
2
using H
2
O as an electron donor and solar light. At present, only insufficient amounts of CO
2
-reduction products such as CO, CH
3
OH, and CH
4
have been obtained using such a photocatalytic and photoelectrochemical conversion process. Here, we demonstrate that photocatalytic CO
2
conversion with a Ag@Cr-decorated mixture of CaGa
4
O
7
-loaded Ga
2
O
3
and the CaO photocatalyst leads to a satisfactory CO formation rate (>835 µmol h
−1
) and excellent selectivity toward CO evolution (95%), with O
2
as the stoichiometric oxidation product of H
2
O. Our photocatalytic system can convert CO
2
gas into CO at >1% CO
2
conversion (>11531 ppm CO) at ambient temperatures and pressures.
The K and Sr cations (K+ and Sr2+) in a Sr2KTa5O15 photocatalyst were found to be easily substituted by Na cations (Na+) to form Sr x K y Na z Ta5O15 by a facile one-pot flux method using a mixture ...of potassium chloride (KCl) and sodium chloride (NaCl). Sr x K y Na z Ta5O15 fabricated using a mixture of KCl and NaCl with a Ag cocatalyst showed enhanced photocatalytic activity without apparent change in selectivity toward CO for the photocatalytic conversion of CO2 using H2O. The present study demonstrates that the flux treatment significantly affected the phase, morphology, band gap, and surface Sr composition of the catalyst owing to the substitution of K+ and Sr2+ for Na+. The stability and durability of the catalyst were also enhanced as compared to those of the photocatalyst fabricated using only KCl flux due to more stable Ag on the surface of Sr x K y Na z Ta5O15.
In order to improve TWC performance it is essential to prohibit the deactivation of PGM particles on catalyst. In this study we investigated the influence of air to fuel ratio (A/F) in engine-exhaust ...aging on TWC performance and deactivation property of Rh catalyst. The catalyst reduced at high temperature exhibited the improved thermal durability and superior TWC performance. XAFS spectroscopy indicated existence of the small diameter or the disordered structure of Rh metal particles on the catalyst reduced at high temperature.
PDF
