A wide range of dose-rates have been used in radiation biology and radiation therapy, extending from a few cGy per day to hundreds of Gy in a fraction of a second. The dose-rate range of importance in radiotherapy extends from about 0.1 Gy/hr to several Gy/min. In this range, the fraction of cells killed by a given dose decreases as the dose-rate is reduced, principally because of the repair of...

A mathematical model of biofilm dynamics was used to investigate the protection from antibiotic killing that can be afforded to microorganisms in biofilms based on a mechanism of localized nutrient limitation and slow growth. The model assumed that the rate of killing by the antibiotic was directly proportional to the local growth rate. Growth rates in the biofilm were calculated by using the l...

Staphylococcus aureus is an opportunistic pathogen and remains a common cause of burn wound infections. Different studies have shown that entrapment of plant-derived compounds into liposomes could increase their anti-Staphylococcus aureus activity. Silymarin is the bioactive extract from the known plant Silybum marianum L. The objective of this study was to evaluate efficacy of silymarin in fre...

Two modes of killing of Escherichia coli K-12 by hydrogen peroxide can be distinguished. Mode-one killing was maximal with hydrogen peroxide at a concentration of 1 to 2 mM. At higher concentrations the killing rate was approximately half maximal and was independent of H2O2 concentration but first order with respect to exposure time. Mode-one killing required active metabolism during the H2O2 c...

Abstract Building long-lasting antimicrobial and clean surfaces is one of the most effective strategies to inhibit bacterial infection, but obtaining an ideal smart surface with highly efficient, controllable, regenerative properties still encounters many challenges. Herein, we fabricate ultrathin brush–hydrogel hybrid coating (PSBMA-P(HEAA- co -METAC)) by integrating antifouling polyzwitterion...

We show that a single clinical isolate of the human opportunistic pathogen Pseudomonas aeruginosa (strain PA14), which previously was shown to be pathogenic in mice and plants, also kills Caenorhabditis elegans. The rate of PA14-mediated killing of C. elegans depends on the composition of the agar medium on which PA14 is grown. When PA14 is grown on minimal medium, killing occurs over the cours...

We study the weak approximation of a multidimensional di usion (Xt)06t6T killed as it leaves an open set D, when the di usion is approximated by its continuous Euler scheme (X̃t)06t6T or by its discrete one (X̃ti )06i6N , with discretization step T=N . If we set := inf{t ¿ 0: Xt 6∈ D} and ̃c := inf{t ¿ 0: X̃t 6∈ D}, we prove that the discretization error Ex[5T¡̃c f(X̃T )]−Ex[5T¡ f(XT )] can be expan...

Adequate concentrations of beta-lactam antibiotics in cerebrospinal fluid (CSF) are difficult to achieve for meningitis caused by drug-resistant Streptococcus pneumoniae. Ceftriaxone in dosages of 150 or 400 mg/kg of body weight per day, given in one or two doses, was used for the treatment of experimental highly cephalosporin-resistant (MIC and MBC, 4 microg/ml) pneumococcal meningitis. The ba...

Recent experimental advances have allowed the estimation of the in vivo rates of killing of infected target cells by cytotoxic T lymphocytes (CTL). We present several refinements to a method applied previously to quantify killing of targets in the spleen using a dynamical model. We reanalyse data previously used to estimate killing rates of CTL specific for two epitopes of lymphocytic choriomen...