Relationship between HLA-II Gene Polymorphisms and Immune Response in COVID-19 Survivors and Volunteers Vaccinated against This Infection.

The polymorphism of HLA class II genes was studied in COVID-19 survivors and vaccinated people. Six allelic variants of DQA1, 10 of DQB1, and 11 of DRB1 were identified. The DQA1*05:01 allele predominated in vaccinated volunteers and the DQA1*02:01, *01:03, and DQB1*06:02-8 alleles predominated in convalescents.

High Densification of Tungsten via Hot Pressing at 1300 °C in Carbon Presence.

A reactive sintering technique with a small addition of carbon (up to 1.9 wt.%) has been used for tungsten powder consolidation.

Peculiarities of Humoral Immunity Formation in Medical Institution Employees Recovered from or Vaccinated against COVID-19 in Irkutsk.

We performed a seroepidemiological survey of the level and structure of population immunity to SARS-CoV-2 among employees of medical institution in the Irkutsk region during the COVID-19 pandemic. Seroprevalence assessment was organized from May 2020 to April 2021. The level of antibodies to SARS-CoV-2 was measured by ELISA.

Reaction Sintering of Machinable TiB-BN-C Ceramics with In-Situ Formed h-BN Nanostructure.

Soft TiB-BN-C hetero-modulus ceramics were sintered with the assistance of in-situ reactions during the hot pressing of TiN-BC precursors. TiB formation was observed already after the hot pressing at 1100 °C, remaining the only phase identifiable by XRD even after sintering at 1500 °C. Analysis of reaction kinetics allows us to assume that the most probable reaction controlling stage is boron atoms sublimation and gas phase transfer from BC to TiN.

Reaction Sintering of Biocompatible AlO-hBN Ceramics.

Biocompatible AlO-hBN ceramic was sintered from AlN and BO precursors by reaction hot pressing at 1750 °C and 30 MPa for 8 min. The ceramic was compared to nonreactive (NR) one sintered from AlO and BN under the same sintering conditions. The NR ceramic possesses 9% porosity as opposed to only 2% porosity for the reaction sintered AlO-hBN.