Layers of the Atmosphere

In this activity, students learn that the atmosphere can be divided into layers based on temperature changes at different altitudes, by making a graph. They will read the background material, plot data points, and determine where layers begin and end from their comprehension of the reading material. Educational levels: High school, Middle school

Alternate-Day Micafungin Antifungal Prophylaxis in Pediatric Patients Undergoing Hematopoietic Stem Cell Transplantation: A Pharmacokinetic Study

Disseminated fungal infection is a major cause of morbidity and mortality in children undergoing hematopoietic stem cell transplantation (HSCT). Prophylaxis with amphotericin B can be limited by renal toxicity. Oral triazoles can be limited by poor absorption, large interindividual pharmacokinetic (PK) variability, and hepatic toxicity, leading to interruptions in therapy and breakthrough infections. Intravenous (i.v.) micafungin has potential advantages, because of its better safety profile, specifically in terms of hepatic and renal toxicity, and lack of drug-drug interactions with common medications used in the HSCT setting. We hypothesized that higher dose micafungin (3 mg/kg) every other day will provide drug exposure similar to standard dosing (1 mg/kg) given daily, and improve patient compliance in very young children in whom oral medications can be challenging, at reduced administration costs. Both animal and adult patient data support the use of this approach. Fifteen children (M/F = 11/4, aged ≤10 years; mean: 3.9 years, range: 0.6-10 years) with various hematologic, metabolic, and immune deficiency disorders undergoing HSCT received a single dose of micafungin (3 mg/kg) i.v. over 1 hour. Dose selection was based on published PK data in pediatric patients, and exploration of different dosing regimens using Monte Carlo PK/PD simulation. Blood samples were drawn around this dose and PK analysis was conducted using standard noncompartmental methods. Micafungin at 3 mg/kg dose was well tolerated in all patients. Measurable plasma concentrations were present in all cases at 48 hours. Half-life and clearance observed were comparable to previous pediatric PK data, with clearance being higher than adults as expected. Volume of distribution was higher in our patients compared to published pediatric data, likely because of a larger proportion of very young children in our study cohort. After correction for protein binding, concentrations at the end of the dosing interval during maintenance treatment remain above the minimum inhibitory concentration (MIC) of highly susceptible fungal pathogens. These data suggest that alternate day micafungin dosing, as described here, may provide an attractive alternative for antifungal prophylaxis in HSCT patients and merits further evaluation

Chiral Perturbation Theory Beyond One Loop

The existing Chiral Perturbation Theory (ChPT) calculations at order $p^6$ are reviewed. The principles of ChPT and how they are used are introduced. The main part is a review of the two- and three-flavour full two-loop calculations and their comparison with experiment. We restrict the discussion to the mesonic purely strong and semileptonic sector. The review concludes by mentioning the existing results in finite volume, finite temperature and partially quenched ChPT.Comment: 66 pages, review article, some references added plus a few discussions extende

Performance of a vibratory shear membrane filtration system during the treatment of magnetic ion exchange process concentrate

The performance of a vibratory shear enhanced processing (VSEP) unit used to treat waste generated from a magnetic ion exchange (MIEX) process is assessed. The unit was fitted with a NF-270 membrane (97% nominal rejection of MgSO4) with an internal membrane surface area of 37 m2. The vibration amplitude of the module was set at 12.7 mm. The system removes greater than 97% dissolved organic carbon as well as 70 − 85% multivalent solutes (Mg2 +, Ca2 +, SO42 −) from the MIEX waste. The permeate generated was high in salt and was successfully recycled to reduce the brine requirement for MIEX resin bead regeneration. Early operation in recirculating batch mode examined the effect of volumetric recoveries (in the permeate) ranging from 75–85%. Higher recovery had no significant influence on the performance of the system. System chemical cleaning was carried out every 14–16 batches. Batch durations generally extended in each subsequent cycle prior to cleaning, with the last batches taking up to five times longer than the first batch. The installation of VSEP has resulted in a reduced frequency of waste disposal from the facility and has also reduced the amount of make-up brine required for resin regeneration by 78%