The highly organized pattern of acetylcholinesterase (AChE) molecules attached to the basal lamina of the neuromuscular junction (NMJ) suggests the existence of specific binding sites for their precise localization. To test this hypothesis we immunoaffinity purified quail globular and collagen-tailed AChE forms and determined their ability to attach to frog NMJs which had been pretreated with h...

Column observations of NO2 by GOME and CO by MOPITT over North America and surrounding oceans for April 2000 are analyzed using a regional chemical transport model. Transient enhancements in these measurements due to lightning NOx production or convective transport are examined. Evidence is found for lightning enhancements of NO2 over the continent and western North Atlantic and for convective ...

To meet Euro VI emission targets for heavy-duty applications, truck manufacturers concentrate on Exhaust Gas Recirculation (EGR) and its combination with urea-based Selective Catalytic Reduction (SCR). TNO developed a concept that opens the route for an alternative solution which relies on SCR as the main technology for NOx abatement. This concept offers potential fuel benefits in combination w...

[1] Chemistry Transport Models (CTMs) tend to underestimate very severely NO2 concentrations in the polar lower stratosphere during the winter suggesting that either the NOx sink is overestimated or a source of NOx is missing in models. We study the night-time decay of polar NO2 because it is controlled by the reaction between NO2 and O3 which is thought to be the main NOx sink at high latitude...

[1] A series of model results is shown pertaining to ozone, reactive nitrogen (NOy), and peroxides in polluted regions. The results focus on ratios such as O3/NOy and H2O2/HNO3 that have been proposed as indicators for O3-NOx-VOC sensitivity. These ratios are shown to correlate with predicted NOx-VOC sensitivity for a variety of zero-dimensional (0-D) and 3-D models, but the correlation varies ...

[1] We investigate the impact of new laboratory studies of N2O5 hydrolysis in aerosols on global model simulations of tropospheric chemistry. We use data from these new studies to parameterize the reaction probability (gN2O5) in the GEOS-CHEM global model as a function of local aerosol composition, temperature, and relative humidity. We find a much lower global mean gN2O5 (0.02) than commonly a...

we report a unique case of chronic dissection of the ascending aorta complicated with huge and thrombotic pseudoaneurysm in a patient with coarctation of descending aorta. preoperative investigations such as transesophageal echocardiography (tee) confirmed the diagnosis of dissection. intraoperative findings included a12 cm eccentric bulge of the right lateral side of dilated the ascending aort...