Comparison of 2.5 vs 7.5 mg of inhaled albuterol in the treatment of acute asthma

Monoamines, including both dopamine and serotonin, synapse onto prefrontal cortical interneurons. Dopamine has been shown to activate these GABAergic interneurons, but there are no direct data on the effects of serotonin on GABA release in the prefrontal cortex. We, therefore, examined the effects of the 5-HT2a/c agonist 1-(2,5-dimethoxy-4-iodophenyl-2-aminopropane (DOI) on extracellular GABA levels in the prefrontal cortex of the rat. Local infusions of DOI dose-dependently increased cortical extracellular GABA levels. In addition, systemic DOI administration resulted in Fos protein expression in glutamic acid decarboxylase67-immunoreactive interneurons of the prefrontal cortex. These data indicate that serotonin, operating through a 5-HT2 receptor, acutely activates GABAergic interneurons in the prefrontal cortex. These data further suggest that there may be convergent regulation of interneurons by dopamine and serotonin in the prefrontal cortex.     

Evaluation of the fatigue fracture resistance of unfilled and filled polytetrafluoroethylene materials

Polytetrafluoroethylenes (PTFEs) and their composites are a special class of fluorocarbons with very high chemical resistance and wide service temperature. This makes them good candidate materials for load-bearing components exposed to harsh environments, including some space applications. In the present work, fatigue crack propagation (FCP) behavior of four materials from the fluorocarbon family, including PTFE without filler (virgin PTFE), PTFE with 15% glass fiber, PTFE with 15% graphite particles, and PTFE with 25% glass fiber, were studied. Tension/tension FCP experiments were carried out using single-edge notch (SEN) specimens under load control. The maximum stress was kept constant at 8 MPa for each material at a frequency of 3 Hz. The minimum to maximum stress ratio was 0.27. FCP data such as the number of cycles, crack length, and hysteresis loops were recorded in order to establish the crack speed, the energy release rate, J*, and the change in work Wi. Parameters that characterize the resistance of PTFEs to FCP have been successfully determined by the modified crack layer (MCL) model. These parameters are , the specific energy of damage, which reflects the FCP resistance of the PTFE materials, and the dissipative characteristic of the materials, . It has been found that the MCL model describes the behavior of the PTFEs over the entire range of the energy release rate and discriminates the subtle effects introduced by changing the filler type and dosage as well as the processing conditions. The values of the specific energy of damage have been found to decrease by increasing the dosage of the fiberglass fillers. Graphite particulate filler also reduced the value of more than fiberglass filler for the same dosage. Microscopic analysis of the fracture surface in the stable crack propagation region of each material revealed that there exists a strong correlation between the value of and the amount of damage energy manifested by different mechanisms and species during the fatigue process.     

Discovering Reactant Supply Pathways at Electrode/PEM Reaction Interfaces Via a Tailored Interface-Visible Characterization Cell

In situ and micro-scale visualization of electrochemical reactions and multiphase transports on the interface of porous transport electrode (PTE) materials and solid polymer electrolyte (SPE) has been one of the greatest challenges for electrochemical energy conversion devices, such as proton exchange membrane electrolyzer cells (PEMECs), CO₂ reduction electrolyzers, PEM fuel cells, etc. Here, an interface-visible characterization cell (IV-CC) is developed to in situ visualize micro-scaled and rapid electrochemical reactions and transports in PTE/SPE interfaces. Taking the PEMEC of a green hydrogen generator as a study case, the unanticipated local gas blockage, micro water droplets, and their evolution processes are successfully visualized on PTE/PEM interfaces in a practical PEMEC device, indicating the existence of unconventional reactant supply pathways in PEMs. Further comprehensive results reveal that PEM water supplies to reaction interfaces are significantly impacted with current densities. These results provide critical insights about the reaction interface optimization and mass transport enhancement in various electrochemical energy conversion devices.     

Ocean-color optical property data derived from the Japanese Ocean Color and Temperature Scanner and the French Polarization and Directionality of the Earth's Reflectances: a comparison study

We describe our efforts to study and compare the ocean-color data derived from the Japanese Ocean Color and Temperature Scanner (OCTS) and the French Polarization and Directionality of the Earth's Reflectances (POLDER). OCTS and POLDER were both on board Japan's Sun-synchronous Advanced Earth Observing Satellite from August 1996 to June 1997, collecting approximately 10 months of global ocean-color data. This operation provided a unique opportunity for the development of methods and strategies for the merging of ocean-color data from multiple ocean-color sensors. We describe our approach to the development of consistent data-processing algorithms for both OCTS and POLDER and the use of a common in situ data set to calibrate vicariously the two sensors. Therefore the OCTS- and POLDER-measured radiances are bridged effectively through common in situ measurements. With this approach to the processing of data from two different sensors, the only differences in the derived products from OCTS and POLDER are the differences that are inherited from the instrument characteristics. Results show that there are no obvious bias differences between the OCTS- and POLDER-derived ocean-color products, whereas the differences due to noise, which stem from variations in sensor characteristics, are difficult to correct at the pixel level. The ocean-color data from OCTS and POLDER therefore can be compared and merged in the sense that there is no significant bias between two.     

Antecedents and Outcomes of Supplier Innovativeness in International Customer–Supplier Relationships: The Role of Knowledge Distance

The increasing competitive pressures and speed of R&D and product innovation is prompting many multinational enterprise customers to outsource their core activities to suppliers. Despite organizational challenges due to cultural and physical separation from their partners, these are now charged with supplier-driven innovation. This study looks at key drivers of supplier innovativeness, examines the role of cross-national differences in shaping supplier innovativeness and examines the impact of this dimension on relationship performance in international customer–supplier relationships. Our findings from a large-scale survey of Taiwanese electronics suppliers provide evidence of the contribution of antecedents such as customer orientation, customer control and technological uncertainty to the enhancement of supplier innovativeness. Innovativeness contributes to increased customer dependence and improves relationship performance. Differences in knowledge bases stemming from different institutions are also tested in this study; we find that knowledge distance may be detrimental to the innovativeness-performance link in international exchange relationships.