Near Infrared Emitting Semiconductor Polymer Dots for Bioimaging and Sensing

Semiconducting polymer dots (Pdots) are rapidly becoming one of the most studied nanoparticles in fluorescence bioimaging and sensing. Their small size, high brightness, and resistance to photobleaching make them one of the most attractive fluorophores for fluorescence imaging and sensing applications. This paper highlights our recent advances in fluorescence bioimaging and sensing with nanoscale luminescent Pdots, specifically the use of organic dyes as dopant molecules to modify the optical properties of Pdots to enable deep red and near infrared fluorescence bioimaging applications and to impart sensitivity of dye doped Pdots towards selected analytes. Building on our earlier work, we report the formation of secondary antibody-conjugated Pdots and provide Cryo-TEM evidence for their formation. We demonstrate the selective targeting of the antibody-conjugated Pdots to FLAG-tagged FLS2 membrane receptors in genetically engineered plant leaf cells. We also report the formation of a new class of luminescent Pdots with emission wavelengths of around 1000 nm. Finally, we demonstrate the formation and utility of oxygen sensing Pdots in aqueous media.

Cricothyrotomy performed by prehospital personnel: a comparison of two techniques in a human cadaver model

Little is known about the proficiency of prehospital personnel when performing cricothyrotomies. The authors compared two techniques for establishing an airway through the cricothyroid membrane used by paramedic students. One technique used a prepackaged kit that consisted of a dilator that is passed percutaneously through a breakaway needle. This percutaneous device (PD) was compared with a standard surgical approach (SA) using a scalpel and endotracheal tube. Data was collected on a total of 44 paramedic students who were allowed to attempt each of the procedures. No significant difference in the success rate on the first attempt was found between the two procedures (86% for the SA and 73% for the PD; P = .186). The surgical approach was significantly faster (46 +/- 17 seconds v 103 +/- 62 seconds; P < .01). It was also judged to be significantly easier to perform when evaluated on a linear analog scale (SA, 2.6 +/- 2.0 v PD, 5.1 +/- 2.8; P < .001). Because some procedures were performed on cadavers whose cricothyroid membranes had already been violated, the procedures performed on intact membranes only were also analyzed. Similar, statistically significant differences for insertion time and ease of insertion were again found. Prehospital personnel can be trained to perform cricothyrotomies with a reasonable degree of proficiency. A traditional surgical approach, however, may be faster and less difficult to perform than a comparable procedure using a commercially available percutaneous device.