Estimated Inpatient Hospital Stay in Individual Wards: Guidelines on Radiation Safety after Radioiodine Therapy

Radionuclide therapy safety requirements are regulated by the Russian Radiation Safety Standards (RRSS), which state the maximum allowed radionuclide activity in the body and the equivalent dose rate (EDR) of gamma radiation. Therefore, it is necessary to estimate the time of an inpatient hospital stay in specially designed radionuclide therapy wards. The article presents the findings of individual 131I biokinetics studies in 64 patients admitted to radioiodine therapy of thyrotoxicosis and differentiated thyroid cancer. We developed a method to calculate the time interval to reach the EDR of 20μSv/h and the recommended EDR of 3 and 0.3μSv/h for adults and children, respectively. It is based on the measurement of the 131I excretion constant. Keywords: Radioiodine therapy, Radiation safety, Guidelin

Клиническое исследование переносимости, безопасности и иммуногенности отечественной гриппозной инактивированной сплит-вакцины «ФЛЮ-М» у детей в возрасте от 6 месяцев до 9 лет

Purpose: To study the reactogenicity, safety and immunogenicity of the Russian vaccine Flu-M in comparison with Vaxigrip vaccine for influenza prevention in children aged from 6 months to 9 years (phase III).Materials and Methods. In 2021, a clinical study was conducted in which children aged 6 months to 9 years were immunized with Flu-M vaccine (produced by SPbSRIVS, Russia) and Vaxigrip vaccine (produced by Sanofi Pasteur S.A., France). After randomization one group of children was vaccinated with Flu-M, the other with Vaxigrip, and monitored for 180±3 days after vaccination. Children vaccinated between 3 and 9 years of age were studied in phase I, and between 6 months and 3 years of age in phase II. Tolerability and safety were assessed by the frequency and extent of adverse events, as well as by the assessment of vital signs and physical examination. Immunological efficacy assessment criteria were geometric mean antibody titer, seroconversion level, seroconversion factor, seroprotection level.Results. Both vaccines (Flu-M and Vaxigrip) were shown to be well tolerated by children of both age groups. No serious adverse events or severe adverse events were reported   in the study. Immunological efficacy criteria were achieved for both vaccines for all strains of influenza virus in children of both age groups at 28 and 56 days after vaccination. No cases of influenza or acute respiratory infections were seen at 180±3 days postvaccination.Conclusion. The results of the clinical study show that the Flu-M and Vaxigrip vaccines are comparable in both age groups of children.The trial is registered at ClinicalTrials.gov (NCT 05470582).Цель: изучение реактогенности, безопасности и иммуногенности отечественной вакцины «Флю-М» в сравнении с вакциной «Ваксигрип» для профилактики гриппа у детей в возрасте от 6 месяцев до 9 лет (фаза III).Материалы и методы: в 2021 г. проведено клиническое исследование при иммунизации детей в возрасте от 6 месяцев до 9 лет вакциной «Флю-М» (производство СПбНИИВС, Россия) и вакциной «Ваксигрип» (производство «Санофи Пастер С.А.», Франция). После рандомизации в соотношении 1:1 одну группу детей прививали вакциной «Флю-М», другую  –  вакциной  «Ваксигрип» и наблюдали в течение 180±3 суток после  вакцинации. На I этапе исследовали детей в возрасте от 3 до    9 лет, на II этапе – в возрасте от 6 месяцев до 3 лет. Переносимость и безопасность оценивали по частоте развития и степени тяжести нежелательных явлений, а также по результатам лабораторных исследований, оценки показателей жизненно важных функций и результатам физикального обследования и неврологического осмотра. Критериями оценки иммунологической эффективности являлись средняя геометрическая титра антител, уровень сероконверсии, фактор сероконверсии, уровень серопротекции.Результаты: показано, что обе вакцины («Флю-М» и «Ваксигрип») хорошо переносились детьми обеих возрастных групп. Нежелательных явлений сильной степени тяжести, а также серьезных нежелательных явлений в исследовании не было зарегистрировано. Критерии иммунологической эффективности были достигнуты для обеих вакцин по всем штаммам вируса гриппа у детей обеих возрастных категорий через 28 и 56 дней после вакцинации. В ходе наблюдения в течение 180±3 суток после вакцинации случаев заболеваемости гриппом или острыми респираторными вирусными инфекциями не отмечалось.Заключение: результаты клинического исследования свидетельствуют о сопоставимости вакцин «Флю-М» и «Ваксигрип» для детей обеих возрастных категорий. Исследование зарегистрировано на ClinicalTrials.gov (NCT05470582)

Broadband and narrowband terahertz generation and detection in GaSe1− xSx crystals

Terahertz wave generation through optical rectification of femtosecond laser pulses and its detection in GaSe and GaSe1−x S x crystals with a relatively low (x = 0.04) and high (x = 0.29) content of sulfur was studied. The decrease of terahertz generation and detection efficiency at an increase of sulfur content in GaSe1−x S x was observed. The phase-matching conditions for electro-optical sampling in GaSe and GaSe1−x S x crystals were analyzed. The arising possibility to achieve the narrowing of terahertz detection bandwidth using thicker GaSe crystals was experimentally confirmed

Broadband and narrowband terahertz generation and detection in GaSe1− xSx crystals

Terahertz wave generation through optical rectification of femtosecond laser pulses and its detection in GaSe and GaSe1−x S x crystals with a relatively low (x = 0.04) and high (x = 0.29) content of sulfur was studied. The decrease of terahertz generation and detection efficiency at an increase of sulfur content in GaSe1−x S x was observed. The phase-matching conditions for electro-optical sampling in GaSe and GaSe1−x S x crystals were analyzed. The arising possibility to achieve the narrowing of terahertz detection bandwidth using thicker GaSe crystals was experimentally confirmed