Introduction Of Delta Research Articles

Phylodynamic analysis of SARS-CoV-2 spread in Rio de Janeiro, Brazil, highlights how metropolitan areas act as dispersal hubs for new variants.

During the first semester of 2021, all of Brazil has suffered an intense wave of COVID-19 associated with the Gamma variant. In July, the first cases of Delta variant were detected in the state of Rio de Janeiro. In this work, we have employed phylodynamic methods to analyse more than 1 600 genomic sequences of Delta variant collected until September in Rio de Janeiro to reconstruct how this variant has surpassed Gamma and dispersed throughout the state. After the introduction of Delta, it has initially spread mostly in the homonymous city of Rio de Janeiro, the most populous of the state. In a second stage, dispersal occurred to mid- and long-range cities, which acted as new close-range hubs for spread. We observed that the substitution of Gamma by Delta was possibly caused by its higher viral load, a proxy for transmissibility. This variant turnover prompted a new surge in cases, but with lower lethality than was observed during the peak caused by Gamma. We reason that high vaccination rates in the state of Rio de Janeiro were possibly what prevented a higher number of deaths.

Calcium metabolism evaluated by 47calcium-kinetics: a physiological model with correction for faecal lag time and estimation of dermal calcium loss.

Sixty-two calcium balance and 47Ca-turnover studies were performed in 51 individuals to evaluate the accuracy and the sensitivity of the methods. The data were analysed according to a modification of the expanding calcium pool model using an improved Bauer-Carlsson-Lindquist (BCL) formulation and an iterative computer procedure. A 7-day whole body retention curve (R1) combined with a retention curve constructed from excretion data alone (R2) was used to estimate dermal calcium loss (d) and to demonstrate the significance of individual corrections for delay in faecal excretion (faecal lag time = delta t). The mean d was 1.58 mmol Ca/day. The introduction of delta t improved the goodness of fit of the data to the model. delta t based on 47Ca-kinetics was superior to a fixed delta t of zero (P less than 0.01) or 2 days (P less than 0.05). The model derived renal calcium excretion rate was highly correlated (r = 0.98, P less than 0.001) to the chemical measured excretion rate. A similar highly significant correlation [RS = 0.78 (Spearman), P less than 0.001] was found between the model derived delta t and the carmine red delta t. These results indicate a high accuracy of the model. The directly measured parameters showed an excellent reproducibility with a coefficient of variation (CV) less than 4%. The reproducibility of the derived parameters was acceptable (CV = 10-20%) except for the balance (CV = 72%).