ABSTRACT
We compared the affinities of ceftaroline for all penicillin-binding proteins (PBPs) with those of ceftriaxone and cefotaxime in 6 Staphylococcus aureus and 7 Streptococcus pneumoniae isolates with various resistance phenotypes. Ceftaroline MICs were
Subject(s)
Anti-Bacterial Agents/pharmacology , Cephalosporins/pharmacology , Drug Resistance, Microbial/physiology , Methicillin-Resistant Staphylococcus aureus/drug effects , Penicillin G/pharmacology , Streptococcus pneumoniae/drug effects , beta-Lactams/pharmacology , Anti-Bacterial Agents/metabolism , Binding, Competitive/physiology , Cefotaxime/metabolism , Cefotaxime/pharmacology , Cephalosporins/metabolism , Methicillin-Resistant Staphylococcus aureus/growth & development , Methicillin-Resistant Staphylococcus aureus/metabolism , Microbial Sensitivity Tests , Penicillin G/metabolism , Streptococcus pneumoniae/growth & development , Streptococcus pneumoniae/metabolism , beta-Lactams/metabolism , CeftarolineABSTRACT
Dry 40x and 60x microscope objectives were fitted with opaque black masks in order to eliminate reflection and scattering of light off the objective front lens assembly during oblique incidence reflection (OIR) microscopy. The reflection and scattering are shown to induce background glare that leads to degradation in the quality of the OIR images. Mask prototypes were designed and machined to snap onto the spring-loaded retractable front lens assembly of each objective. OIR images of live cells and normalized intensity line profiles are used to demonstrate that, if these alterations to the housing of the objective are implemented, background glare is significantly reduced with the 60x objective, and virtually eliminated with the 40x objective.
Subject(s)
Glare/adverse effects , Image Processing, Computer-Assisted/standards , Contrast Sensitivity , HeLa Cells , Humans , Light , Scattering, RadiationABSTRACT
Spiral computed tomography (CT) has recently become available as a practical diagnostic tool; its introduction has created the need for a comprehensive understanding of the magnitude and distribution of the radiation dose to the patient. Dose distributions for conventional and spiral CT were measured with thermoluminescent dosimeters loaded in standard phantoms and then compared to determine the validity of using standard dose descriptors for assessing the dose delivered during spiral CT. Two dose descriptors applied to conventional CT, the CT dose index and the multiple-scan average dose, were found to be adequate for quantifying the dose delivered by spiral CT.