The impact of COVID-19 infection before the vaccination era on the hospitalized patients requiring hemodialysis: a single-center retrospective cohort.

Due to effective vaccinations, the COVID-19 (coronavirus disease 2019) infection that caused the pandemic has a milder clinical course. We aimed to assess the mortality of hospitalized COVID-19 patients before the vaccination era. We investigated the mortality in those patients between 1 October 2020 and 31 May 2021 who received hemodialysis treatment [patients with previously normal renal function (nCKD), patients with chronic kidney disease previously not requiring hemodialysis (CKDnonHD), chronic kidney disease (CKD), and patients on regular hemodialysis (pHD)]. In addition, participants were followed up for all-cause mortality in the National Health Service database until 1 December 2021. In our center, 83 of 108 (76.9%) were included in the analysis due to missing covariates. Over a median of 26 (interquartile range 11-266) days of follow-up, 20 of 22 (90.9%) of nCKD, 23 of 24 (95.8%) of CKDnonHD, and 17 of 37 (45.9%) pHD patients died (p < 0.001). In general, patients with nCKD had fewer comorbidities but more severe presentations. In contrast, the patients with pHD had the least severe symptoms (p < 0.001). In a model adjusted for independent predictors of all-cause mortality (C-reactive protein and serum albumin), CKDnonHD patients had increased mortality [hazard ratio (HR) 1.91, 95% confidence interval (CI), 1.02-3.60], while pHD patients had decreased mortality (HR 0.41, 95% CI 0.20-0.81) compared to nCKD patients. After further adjustment for the need for intensive care, the difference in mortality between the nCKD and pHD groups became non-significant. Despite the limitations of our study, it seems that the survival of previously hemodialysis patients was significantly better.

Stochastic Modeling of In Vitro Bactericidal Potency.

We provide a Galton-Watson model for the growth of a bacterial population in the presence of antibiotics. We assume that bacterial cells either die or duplicate, and the corresponding probabilities depend on the concentration of the antibiotic. Assuming that the mean offspring number is given by [Formula: see text] for some [Formula: see text], where c stands for the antibiotic concentration we obtain weakly consistent, asymptotically normal estimator both for [Formula: see text] and for the minimal inhibitory concentration, a relevant parameter in pharmacology. We apply our method to real data, where Chlamydia trachomatis bacterium was treated by azithromycin and ciprofloxacin. For the measurements of Chlamydia growth quantitative polymerase chain reaction technique was used. The 2-parameter model fits remarkably well to the biological data.

Lateral instability of stationary spherical reaction balls.

Three-dimensional stability of stationary reaction balls is investigated in a system consisting of an autocatalysis accompanied by a slow decay of the autocatalyst. Radially stable stationary spherical structures become unstable to three-dimensional perturbations at small decay rate when the radius of the reaction ball is sufficiently large and the reactant diffuses faster than the autocatalyst. A thorough linear stability analysis and simulations in three spatial dimensions are carried out in the simplest system sustaining stationary reaction balls.