Here we report a method for highly reproducible chronoamperometric analysis of the contents of microdroplets. Aqueous microdroplets having volumes on the order of 1 nL and separated by a fluorocarbon solvent are generated within a microfluidic device using a T-shaped junction. The key finding is that stable and reproducible quasi-steady-state currents are observed if the electrochemical measure...

When etching high-aspect-ratio silicon features using deep reactive ion etching DRIE , researchers find that there is a maximum achievable aspect ratio, which we define as the critical aspect ratio, of an etched silicon trench using a DRIE process. At this critical aspect ratio, the apparent etch rate defined as the total depth etched divided by the total elapsed time no longer monotonically de...

We use a microfluidic device to prepare monodisperse amphiphilic particles in the shape of a crescent-moon and use these particles to stabilize oil droplets in water. The microfluidic device is comprised of a tapered capillary in a theta (θ) shape that injects two oil phases into water in a single receiving capillary. One oil is a fluorocarbon, while the second is a photocurable monomer, which ...

The structures of semifluorinated alkanethiol self-assembled monolayers (SAMs) generated by the adsorption of CF3(CF2)9(CH2)nSH (F10HnSH, n ) 2, 6, 11, 17, 33) onto gold were investigated with atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and surface plasmon resonance spectroscopy. Images obtained by AFM of the F10H2SH SAM showed a remarkably ordered 2D hexagonal lattic...

OBJECTIVES The goal of this study was to determine, in patients with a recent myocardial infarction (MI) and residual wall motion abnormalities within the distribution of the infarct-related artery, whether normal perfusion by myocardial contrast echocardiography (MCE) would accurately predict recovery of segmental left ventricular (LV) function. BACKGROUND Left ventricular dysfunction after ...

Fluorocarbon-modified polyacrylamide chains can form large multichain aggregates. The aggregation behavior of a series of fluorocarbon-modified polyacrylamides in water has been investigated by a combination of static and dynamic laser light scattering (LLS). The critical aggregation concentration (CAC) was estimated from the emergence of a second peak in the line-width distribution measured in...

Bioprinting is a recent development in tissue engineering, which applies rapid prototyping techniques to generate complex living tissues. Typically, cell-containing hydrogels are dispensed layer-by-layer according to a computer-generated three-dimensional model. The lack of mechanical stability of printed hydrogels hinders the fabrication of high aspect ratio constructs. Here we present submerg...

Alkyl β-d-xylopyranosides are highly surface active, biodegradable surfactants that can be prepared from hemicelluloses and are of interest for use as pharmaceuticals, detergents, agrochemicals, and personal care products. To gain further insights into their structure-property and structure-activity relationships, the present study synthesized a series of hydrocarbon (-C(6)H(13) to -C(16)H(33))...

Experiments are performed to correlate and model CHF during subcooled flow boiling of dielectric fluoro~rbon (FC-72) liquid on a smooth 12.7 x 12.7 mm* sirn~at~ electronic chip inside a vertical rectangular channel. Two distinct CHF regimes are established based on flow visualization and experimental data. At low flow velocities, CHF is accompanied by the formation of a continuous vapor blanket...

We studied trifluoromethane as a potential gaseous indicator in nuclear magnetic resonance measurements of cerebral blood flow. We considered the effects of trifluoromethane on cerebral blood flow in 17 cats and on the electroencephalogram and electrocardiogram in nine cats and compared these with the effects of the more toxic compound chlorodifluoromethane in five cats. Inhaled at 60%, trifluo...