Hemozoin-generated vapor nanobubbles for transdermal reagent- and needle-free detection of malaria.

Successful diagnosis, screening, and elimination of malaria critically depend on rapid and sensitive detection of this dangerous infection, preferably transdermally and without sophisticated reagents or blood drawing. Such diagnostic methods are not currently available. Here we show that the high optical absorbance and nanosize of endogenous heme nanoparticles called "hemozoin," a unique component of all blood-stage malaria parasites, generates a transient vapor nanobubble around hemozoin in response to a short and safe near-infrared picosecond laser pulse. The acoustic signals of these malaria-specific nanobubbles provided transdermal noninvasive and rapid detection of a malaria infection as low as 0.00034% in animals without using any reagents or drawing blood. These on-demand transient events have no analogs among current malaria markers and probes, can detect and screen malaria in seconds, and can be realized as a compact, easy-to-use, inexpensive, and safe field technology.

Brief report: engagement in sport and identity status.

Drawing on identity development theory, the connection between engagement in sport and identity status was examined. First-year undergraduates (n = 116 sport-involved youth; 67% women; mean age = 18.58 yrs) completed measures of interpersonal and ideological identity status (achievement, moratorium, diffusion, foreclosure), along with behavioral (breadth, intensity) and psychological (e.g., enjoyment, competence) indicators of sport engagement. Using structural equation modeling, we examined the relation between latent sport engagement and identity status in interpersonal and ideological domains. As hypothesized, latent sport engagement predicted greater interpersonal (but not ideological) identity achievement. Consistent with identity development theory, an additional specific relation was observed between lower breadth of sport involvement and higher interpersonal identity achievement. Results demonstrate the value of examining behavioral and psychological indicators of sport engagement jointly, and support a growing body of research linking sport and positive youth development.

Development of ambulatory arterio-venous carbon dioxide removal (AVCO2R): the downsized gas exchanger prototype for ambulation removes enough CO2 with low blood resistance.

We are developing an ultra compact gas exchanger to allow ambulation during arterial-venous CO2 removal (AVCO2R). The ambulatory AVCO2R gas exchanger (135 ml prime volume and 1.3 M2 gas exchange surface area) is made of polymethylpentene hollow fibers. The gas exchanger was attached to sheep carotid artery (12F) and jugular vein (14F) by percutaneous cannulae for 6 hours (n = 5). Device CO2 removal was measured and calculated at a constant blood flow rate of 1 L/min coupled with varying sweep gas from 1 to 15 L/min, and at constant sweep gas flow of 2 L/min coupled with varying blood flow from 0.5 to 1.25 L/min to determine capacity of CO2 removal at Pa CO2 = 40-50 mm Hg. Blood gases, CO2 removal and hemodynamics were recorded at 0, 3, and 6 hours. CO2 removal increased with sweep gas flow rate and with increase of device blood flow. Hemodynamics remained unchanged throughout study. Gas exchanger resistance remained stable at 2.3 +/- 0.53 mm Hg/L/min. CO2 removal with 1 L/min blood flow and 2 L/min sweep gas was 110 +/- 12 then stabilized at 85 +/- 14 mL/min to 6 hours. The compact ambulatory AVCO2R gas exchanger achieves stable, near total CO2 removal for at least 6 hours with a simple arteriovenous shunt.