Rocketborne Measurement of Mesospheric H2O in the Auroral Zone

Infrared emission spectra of the longwavelengtwhi ngo f the 6.3 • waterb andb etween6 .7 and 7.6 yxa have been measured in the mesosphere using a cryogenic rocketborne spectrometerø The resulting zenith radiance profile has been compared with a high altitude radiance model resulting in a volumem ixingra tioo f 3ø5 -+ 2.2 ppmb etwee4n9 and 70 k

Rodent models of focal cerebral ischemia: procedural pitfalls and translational problems

Rodent models of focal cerebral ischemia are essential tools in experimental stroke research. They have added tremendously to our understanding of injury mechanisms in stroke and have helped to identify potential therapeutic targets. A plethora of substances, however, in particular an overwhelming number of putative neuroprotective agents, have been shown to be effective in preclinical stroke research, but have failed in clinical trials. A lot of factors may have contributed to this failure of translation from bench to bedside. Often, deficits in the quality of experimental stroke research seem to be involved. In this article, we review the commonest rodent models of focal cerebral ischemia - middle cerebral artery occlusion, photothrombosis, and embolic stroke models - with their respective advantages and problems, and we address the issue of quality in preclinical stroke modeling as well as potential reasons for translational failure

INFRARED CHEMILUMINESCENCE FROM THE NO-O REACTION SYSTEM STUDIED BY FOURIER SPECTROSCOPY

Author Institution: Concord Radiance Laboratory Utah State University, Bedford, Massachusetts; Air Force Cambridge Research Laboratories (O.A.R.), L.G. Hanscom Field. Bedford, Massachusetts, 01731.Infrared emission from the low-pressure gas-phase NO-O reaction system has been studied from 1 to 6.5 microns. An infrared integrating sphere has been used for the reaction cell to provide increased light-gathering efficiency, and because of the relatively weak source, the emission spectra were observed with an interferometer spectrometer. Spectra obtained indicate that the ``continuum'' associated with the NO-O recombination extends to at least 4 microns. Vibrational emissions from $NO, NO_{2}$, and $N_{2}O$ have been observed and their relative intensities studied versus concentrations of the reactants. Several weaker bands have also been observed, but are presently unidentified. The intensity of the vibrational emission relative to the continuum radiation has been found to be pressure-dependent due to the considerably different radiative and collision lifetimes involved. Infrared emission spectroscopy may be able to contribute much to the study of chemical kinetics

Infrared chemiluminescence and vibraluminescence in the NO — O — NO

Infrared emission from the low-pressure gas-phase NO — О reaction system has been studied from 1 to 7,0 microns. An infrared integrating sphere has been used for the reaction cell to provide increased lightgathering efficiency, and because of the relatively weak source, the emission spectra were obtained with an interferometer spectrometer. The « continuum « associated with the NO + O recombination decreases monotonically and extends to at least 3,7 microns. Vibrational-rotational spectra from NO and NO2 have been observed and their relative intensities studied versus concentrations of the reactants. An unidentified band is observed at 3,7 microns whose intensity varies directly with the intensity of both the continuum and the NO2ν3 fundamental at 6,3 microns. The intensity of the vibrational-rotational emission relative to the continuum radiation has been found to be pressure-dependent due to the considerably different radiative lifetimes and collisional deactivation processes involved. The ν3 fundamental band of NO2 at 6,3 microns excited by chemiluminescence in the NO + О → NO2* reaction is broader and, therefore, excited to higher vibrational levels than it is when excited by vibrational exchange with O2 [math] (vibraluminescence). The vibrational excitation of O2 occurs in the fast reaction NO2+ О → NO[math] + O2[math]. Chemiluminescence from NO[math] is also observed in this reaction which demonstrates excitation of both the newly formed bound and the unbroken bond simultaneously