Seroprevalence of Natural and Acquired Immunity against the SARS-CoV-2 Virus in a Population Cohort from Two Chilean Cities, 2020-2022.

BACKGROUND: Chile has achieved the highest coverage for vaccines against the SARS-CoV-2 virus worldwide. OBJECTIVE: To assess the progression of immunity (natural and acquired by vaccine) in a cohort from two Chilean cities. METHODS: Individuals (n = 386) who participated in three phases of population-based serial prevalence studies were included (2020-2021 and 2022). Presence of SARS-CoV-2 antibodies was measured in serum. Data including time of vaccination and type of vaccine received were analysed with descriptive statistics. RESULTS: Seroprevalence was 3.6% in the first round and increased to 96.9% in the second and 98.7% in the third. In the third round, 75% of individuals who had received the basal full scheme were seropositive at 180 days or more since their last dose; 98% of individuals who received one booster dose were seropositive at 180 days or more, and 100% participants who received two boosters were seropositive, regardless of time since their last dose. Participants receiving mRNA vaccines had higher seroprevalence rates over time. CONCLUSIONS: The high vaccination coverage in Chile enabled the population to maintain high levels of antibodies. Vaccination boosters are essential to maintain immunity over time, which also depends on the type of vaccine administered.

Design and implementation of a control structure for quality products in a crude oil atmospheric distillation column.

In recent years, interest for petrochemical processes has been increasing, especially in refinement area. However, the high variability in the dynamic characteristics present in the atmospheric distillation column poses a challenge to obtain quality products. To improve distillates quality in spite of the changes in the input crude oil composition, this paper details a new design of a control strategy in a conventional crude oil distillation plant defined using formal interaction analysis tools. The process dynamic and its control are simulated on Aspen HYSYS® dynamic environment under real operating conditions. The simulation results are compared against a typical control strategy commonly used in crude oil atmospheric distillation columns.

Tuberculosis osteoarticular: caso clínico y revisión de la literatura / Osteoarticular tuberculosis: case report and literature review

La tuberculosis es menos frecuente que hace unas decada, pero es importante para el pediatra considerarla entre los diagnósticos diferentes de la artritis séptica de cadera, como lo demuestra el caso clínico que se publica a continuación.

Neuritis óptica por Bartonella Henselae: dos casos: Nº 1 / Optic neuritis by Bartonella Henselae: two cases: Nº 1

La neuritis ótica (NO) corresponde a una neuropatía óptica determinada por un proceso inflamatorio focal asociado a desmielinización [1]. Su etiología es variada. En niños es principalmente de naturaleza infecciosa o parainfecciosa lo que determina un curso generalmente benigno, sin embargo, al estar asociada a esclerosis múltiple (EM), donde corresponde a la primera manifestación en el 75 por ciento de los casos, adopta una connotación distinta dado el desalentador pronóstico que implica [2].