Thickness-dependent Electrical and Piezoelectric Properties of Lead-Free Ferroelectric Ba[0.8]Sr[0.2]TiO[3] Thin Films

The thickness dependent of electrical and piezoelectric properties of lead-free ferroelectric Ba[0.8]Sr[0.2]TiO[3] thin films is reported. Ba[0.8]Sr[0.2]TiO[3] (BST 80/20) thin films for various thickness, ranging from 150 nm to 550 nm, were prepared by high-frequency reactive sputtering of a ceramic target in an oxygen atmosphere on p-type Si substrate. Memory windows and effective dielectric constant of the BST film in Au/BST/Si thin film capacitors is found to increase with the increasing thickness of the film. Domain structure, domain switching and hysteresis loops of the BST 80/20 thin film were investigate via the piezoresponse force microscopy. Complete domain switching and strong piezoresponse are found in the ferroelectric BST film. The piezoelectric coefficient and the remnant piezoelectric response (ΔPR) of BST 80/20 films is found to increase with the thickness of the fil

Importance of herpes viruses in children with post-COVID conditions

M.S. Savenkova1,2, I.A. Sotnikov2, A.A. Afanasieva1,2, Ya.V. Afanasieva3, R.V. Dushkin4 1Pirogov Russian National Research Medical University, Moscow, Russian Federation 2Morozov Children's City Clinical Hospital, Moscow, Russian Federation 3All-Russian Public Organization “Russian Academy of Engineering”, Moscow, Russian Federation 4LLC “Agency of Artificial Intelligence,” Moscow, Russian Federation Aim: to assess the prevalence of detection of confirmed herpes virus infections (HVI) in children who had a previous COVID-19 infection, characterize specific clinical manifestations of the disease under the new conditions (post-COVID syndrome), and to provide a rationale for the administration of drug therapy. Patients and Methods: of 456 patients who received medical consultations from September 2021 to July 2022, the authors selected 72 (15.8%) children (42 boys and 30 girls) who had a previous SARS-CoV-2 infection confirmed by serological tests or polymerase chain reaction and in whom herpes viruses were found during serological evaluation. Results: most of the children (81.4%) visited the polyclinic within the first six months after the COVID-19 infection. Epstein-Barr virus (EBV) was the most prevalent finding among herpesviruses detected in children with post-COVID-19 sequela — it was detected in 44 (61.1%) cases. Human herpesvirus (HHV) 6 and cytomegalovirus (CMV) were less common in this group and found in 41 (56.9%) and 30 (41.7%) children, respectively. HHV-1 and HHV-2 were detected more rarely — in 11 (15.3%) children. Monoinfection was diagnosed in 41 (56.9%) cases and a combination of viruses was found in 31 children, in 22 (71.0%) of them it comprised two viruses, in 6 (19.3%) — three viruses, and in 3 (9.7%) — four viruses. The presence of herpesvirus infections underpinned the main reasons why parents of the ill children were seeking for outpatient care, in particular: a prolonged subfebrile condition (18.0%), fatigue and sleep disorders (27.7%), rashes (16.6%), lymphadenopathy (16.7%), ENT diseases (33.3%), more frequently occurring respiratory diseases (33.3%), and the increase in seizure activity in children with epilepsy (8.3%). In addition to herpes viruses, pathogenic agents were detected in 18% of patients, including intracellular pathogens, which were found in 13.9% of 72 children. Taking into consideration the obtained results and established clinical diagnoses, the authors conducted a review and provided a rationale for the administered drug therapy, including medications for herpes treatment. Conclusion: a prior COVID-19 infection induces immunosuppression and, as a result, the activation of herpesvirus infections as long-term effects of COVID-19 (post-COVID conditions). The presence of mixed viral and bacterial pathogens is an indication for administering antivirals, immunomodulators, antibacterial agents, and probiotics. Keywords: post-COVID conditions, herpesvirus infections, children, clinical symptoms, treatment. For citation: Savenkova M.S., Sotnikov I.A., Afanasieva A.A. et al. Importance of herpes viruses in children with post-COVID conditions. Russian Journal of Woman and Child Health. 2023;6(1):39–44 (in Russ.). DOI: 10.32364/2618-8430-2023-6-1-39-44. <br