Room-temperature ultraviolet nanowire nanolasers.

Room-temperature ultraviolet lasing in semiconductor nanowire arrays has been demonstrated. The self-organized, <0001> oriented zinc oxide nanowires grown on sapphire substrates were synthesized with a simple vapor transport and condensation process. These wide band-gap semiconductor nanowires form natural laser cavities with diameters varying from 20 to 150 nanometers and lengths up to 10 micrometers. Under optical excitation, surface-emitting lasing action was observed at 385 nanometers, with an emission linewidth less than 0.3 nanometer. The chemical flexibility and the one-dimensionality of the nanowires make them ideal miniaturized laser light sources. These short-wavelength nanolasers could have myriad applications, including optical computing, information storage, and microanalysis.

Out-diffusion and precipitation of copper in silicon: An electrostatic model

Concentrations of mobile interstitial copper and precipitated copper in silicon were studied after a high temperature intentional contamination and quench to room temperature. It was found that below a critical contamination the copper predominantly diffuses out to the surface, while for higher initial copper concentrations it mainly precipitates in the bulk. The critical copper contamination equals the acceptor concentration plus 10(16) cm (-3). This behavior can be explained by the electrostatic interaction between the positively charged interstitial copper and the forming copper precipitates.

Impact of venous catheters on packed red blood cells.

This study was designed to test the hypothesis that there would be increased hemolysis, as indicated by an increase in plasma free hemoglobin and potassium, when packed cells were infused through small gauge percutaneous catheters (24 and 28 g, PC) compared with short catheters (24 g; SC). We were unable to study the 28 g PC because after 1 hour, at a flow rate of 10 ml/hr, only 2.4 ml packed cells were infused. There was a significant increase in plasma free hemoglobin when pre- and postinfusion values were compared (SC, p = 0.005; PC, p = 0.009), but a statistically significant increase in potassium only for the SC (p = 0.008). There were no significant differences between the catheters for either potassium or free hemoglobin. For either catheter the quantity of free hemoglobin transfused could potentially cause a significant rise in serum bilirubin and hemoglobinuria.

Successful medical treatment of Candida parapsilosis endocarditis in a premature infant.

Endocarditis is an uncommon complication of disseminated candidiasis among premature infants, but has been recently reported to be almost uniformly fatal. The lone previously documented survivor required extensive surgical resection as well as prolonged systemic antifungal therapy. The present report details a premature infant who recovered from Candida endocarditis with medical therapy alone.