Raman Fingerprints of the SARS-CoV-2 Delta Variant and Mechanisms of Its Instantaneous Inactivation by Silicon Nitride Bioceramics.

Raman spectroscopy uncovered molecular scale markers of the viral structure of the SARS-CoV-2 Delta variant and related viral inactivation mechanisms at the biological interface with silicon nitride (Si3N4) bioceramics. A comparison of Raman spectra collected on the TY11-927 variant (lineage B.1.617.2; simply referred to as the Delta variant henceforth) with those of the JPN/TY/WK-521 variant (lineage B.1.617.1; referred to as the Kappa variant or simply as the Japanese isolate henceforth) revealed the occurrence of key mutations of the spike receptor together with profound structural differences in the molecular structure/symmetry of sulfur-containing amino acid and altered hydrophobic interactions of the tyrosine residue. Additionally, different vibrational fractions of RNA purines and pyrimidines and dissimilar protein secondary structures were also recorded. Despite mutations, hydrolytic reactions at the surface of silicon nitride (Si3N4) bioceramics induced instantaneous inactivation of the Delta variant at the same rate as that of the Kappa variant. Contact between virions and micrometric Si3N4 particles yielded post-translational deimination of arginine spike residues, methionine sulfoxidation, tyrosine nitration, and oxidation of RNA purines to form formamidopyrimidines. Si3N4 bioceramics proved to be a safe and effective inorganic compound for instantaneous environmental sanitation.

Raman Molecular Fingerprints of SARS-CoV-2 British Variant and the Concept of Raman Barcode.

The multiple mutations of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus have created variants with structural differences in both their spike and nucleocapsid proteins. While the functional relevance of these mutations is under continuous scrutiny, current findings have documented their detrimental impact in terms of affinity with host receptors, antibody resistance, and diagnostic sensitivity. Raman spectra collected on two British variant sub-types found in Japan (QK002 and QHN001) are compared with that of the original Japanese isolate (JPN/TY/WK-521), and found bold vibrational differences. These included: i) fractions of sulfur-containing amino acid rotamers, ii) hydrophobic interactions of tyrosine phenol ring, iii) apparent fractions of RNA purines and pyrimidines, and iv) protein secondary structures. Building upon molecular scale results and their statistical validations, the authors propose to represent virus variants with a barcode specially tailored on Raman spectrum. Raman spectroscopy enables fast identification of virus variants, while the Raman barcode facilitates electronic recordkeeping and translates molecular characteristics into information rapidly accessible by users.

Lifestyle changes as a result of COVID-19 containment measures: Bodyweight and glycemic control in patients with diabetes in the Japanese declaration of a state of emergency.

To clarify the association between lifestyle changes as a result of coronavirus disease 2019 containment measures and changes in metabolic and glycemic status in patients with diabetes, a cross-sectional, single-center, observation study was carried out. A self-reported questionnaire was provided to ascertain the frequency of various lifestyle activities before and after the coronavirus disease 2019 containment measures in Japan. Among 463 patients, change in glycated hemoglobin was significantly associated with change in bodyweight. After stratification by age 65 years, binary logistic regression analysis showed that increased frequency of snack eating increased bodyweight (odds ratio 1.709, P = 0.007) and glycated hemoglobin (odds ratio 1.420, P = 0.025) in the younger group, whereas in the older patients, reduced walking activities resulted in weight gain (odds ratio 0.726, P = 0.010). In conclusion, changes in eating behavior and physical activity increased bodyweight and reduced glycemic control among diabetes patients, but by different processes depending on age under the coronavirus disease 2019 containment measures in Japan.