Enhancement of transepidermal skin clearing agent delivery using a 980 nm diode laser.

Background And Objectives: Patient compliant optical skin clearing requires non-invasive topical delivery of clearing agents such as glycerol. This requires reducing the skin barrier function by disrupting stratum corneum integrity, which was achieved using a 980 nm diode laser with artificial absorption substrates on the skin surface. Reduction of light scattering has the potential to improve many current and novel diagnostic and therapeutic applications of lasers in medicine.

Comparison of beta-lactam regimens for the treatment of gram-negative pulmonary infections in the intensive care unit based on pharmacokinetics/pharmacodynamics.

Objectives: This study utilized pharmacokinetics/pharmacodynamics to compare beta-lactam regimens for the empirical and definitive treatment of gram-negative pulmonary infections in the ICU.

Methods: Susceptibility data were extracted from the 2002 Intensive Care Unit Surveillance System (ISS) and pharmacokinetic parameters were obtained from published human studies. Monte Carlo simulation was used to model the free percent time above the MIC (free %T > MIC) for 18 beta-lactam regimens against all gram-negative isolates, Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii.

Competitive intermolecular pericyclic reactions of free and complexed cyclopentyne.

Intermolecular competition for cyclopentyne by different alkenes supports the hypothesis that organolithium-promoted decomposition of precursors to cyclopentyne affords one or more lithium-ion-complexed species. Competition reactions with mixtures of 2,3-dihydropyran do not clearly differentiate between complexed and unencumbered (free) forms of cyclopentyne, but those involving spirodiene 2 and cyclohexene do. Remarkably, the cycloaddition reactions of free cyclopentyne are not diffusion-controlled despite its high reactivity.