Numerical solution of COVID-19 pandemic model via finite difference and meshless techniques.

In the present paper, a reaction-diffusion epidemic mathematical model is proposed for analysis of the transmission mechanism of the novel coronavirus disease 2019 (COVID-19). The mathematical model contains six-time and space-dependent classes, namely; Susceptible, Exposed, Asymptomatically infected, Symptomatic infected, Quarantine, and Recovered or Removed (SEQIIR). The threshold number R is calculated by utilizing the next-generation matrix approach.

Structural studies on a carbohydrate chain isolated from the lipopolysaccharide of Shigella boydii type 8.

The lipopolysaccharide isolated from the cells of Shigella boydii type 8 bacteria gave precipitin bands against homologous antisera on Ouchterlony plates, whereas the carbohydrate-containing fractions obtained from it did not. One of the fractions was obtained in major proportion and contained 23.5% of sugars.