It is has been suggested that physical activity may increase bone mineral density (BMD) in children, thereby preventing development of osteoporosis later in life. We studied 14 gymnasts, 14 swimmers, and 17 controls to investigate whether participation in different types of sports among girls 7-9 yr of age is associated with higher total body BMD. Gymnasts were lighter than both swimmers and controls (P = 0.001), and a larger percent of gymnasts compared with swimmers and controls were below the 25th percentile for height and weight. Fat mass, percent body fat, and lean mass were less in gymnasts compared with swimmers and controls (all P < or = 0.05). The relationship between total body BMD and body weight differed among the three groups (interaction term of weight and sport, P < 0.001); the increase in BMD per unit increase in body weight was more among gymnasts than among swimmers and controls. These results indicate that high impact bone loading activities may lead to increased bone density among young girls.

Delafloxacin exhibits linear pharmacokinetic parameters that reached steady state after 3 days of daily oral dosing with minimal accumulation. Delafloxacin was well tolerated throughout both studies, with gastrointestinal effects observed at the higher doses (≥1200 mg).

Delafloxacin was well tolerated in healthy volunteers after single and multiple IV doses. The total systemic exposure to IV (300 mg) and oral (450 mg) delafloxacin is comparable, supporting that a switch between the 2 formulations is appropriate.

A randomized, double-blind, placebo-controlled, 4-period crossover study was conducted in 52 healthy adults to assess the effect of delafloxacin on the corrected QT (QTc) interval. The QT interval, corrected for heart rate using Fridericia's formula (QTcF), was determined predose and at 0.5, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 4, 5, 6, 12, 18, and 24 h after dosing with delafloxacin at 300 mg intravenously (i.v.; therapeutic), delafloxacin at 900 mg i.v. (supratherapeutic), moxifloxacin at 400 mg orally (p.o.; positive control), and placebo. The pharmacokinetic profile of delafloxacin was also evaluated. At each time point after delafloxacin administration, the upper limit of the 90% confidence interval (CI) for the placebo-corrected change from the predose baseline in QTcF (⌬⌬QTcF) was less than 10 ms (maximum, 3.9 ms at 18 h after dosing), indicating an absence of a clinically meaningful increase in the QTc interval. The lower limit of the 90% CI of ⌬⌬QTcF for moxifloxacin versus placebo was longer than 5 ms at all 5 time points selected for assay sensitivity analysis, demonstrating that the study was adequately sensitive to assess QTc prolongation. There was no positive relationship between delafloxacin plasma concentrations and ⌬⌬QTcF. Treatment-emergent adverse events (AEs) were more frequent among subjects receiving a single supratherapeutic dose of 900 mg delafloxacin. There were no deaths, serious AEs, or AEs leading to study discontinuation and no clinically meaningful abnormalities in laboratory values or vital signs observed at any time point after any dose of the study drug. Delafloxacin (RX-3341, ABT-492, and WQ-3034) is an anionic investigational fluoroquinolone antibiotic, currently in phase III development for the treatment of acute bacterial skin and skin structure infections (ABSSSI) based on its activity against Gram-positive microorganisms, including methicillin-resistant Staphylococcus aureus, Gram-negative microorganisms, and anaerobes (1). Pharmacokinetic (PK) studies have shown that the increases in the maximum plasma concentration (C max ) and total exposure (area under the concentration-time curve [AUC]) are dose proportional and greater than dose proportional, respectively, with a single intravenous (i.v.) dose of 300 to 1,200 mg in healthy volunteers (2). Both i.v. and oral formulations are expected to be available, allowing i.v.-to-oral "step-down" therapy in the appropriate patient populations. The proposed dose for the treatment of ABSSSI is 300 mg administered i.v. or 450 mg administered orally (p.o.) twice daily (BID).QT interval prolongation caused by the inhibition of potassium channels encoded by the HERG gene has been described for a variety of drug classes, including the fluoroquinolone antibiotics (3, 4). QT prolongation is associated with an increased risk of life-threatening cardiac arrhythmias, most typically torsades de pointes (TdP). The degree to which the fluoroquinolones block the cardiac potassium channels, thereby prolonging the QT interval, varies by agent (5, 6). In ...

We present here a simple and inexpensive implementation of an electromagnetic coilgun. This device can launch small projectiles (∼200 g) over a distance of one or two meters. This project will provide students with experience in building simple circuits, a tangible demonstration of electromagnetic fields and can lead into a discussion of magnetic properties of materials.

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