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Vapor Exposure (vapor + exposure)
Selected AbstractsChemical Agent Simulant Release from Clothing Following Vapor ExposureACADEMIC EMERGENCY MEDICINE, Issue 2 2010Robert J. Feldman MD ACADEMIC EMERGENCY MEDICINE 2010; 17:1,4 © 2010 by the Society for Academic Emergency Medicine Abstract Objectives:, Most ambulatory victims of a terrorist chemical attack will have exposure to vapor only. The study objective was to measure the duration of chemical vapor release from various types of clothing. Methods:, A chemical agent was simulated using methyl salicylate (MeS), which has similar physical properties to sulfur mustard and was the agent used in the U.S. Army's Man-In-Simulant Test (MIST). Vapor concentration was measured with a Smiths Detection Advanced Portable Detector (APD)-2000 unit. The clothing items were exposed to vapor for 1 hour in a sealed cabinet; vapor concentration was measured at the start and end of each exposure. Clothing was then removed and assessed every 5 minutes with the APD-2000, using a uniform sweep pattern, until readings remained 0. Results:, Concentration and duration of vapor release from clothing varied with clothing composition and construction. Lightweight cotton shirts and jeans had the least trapped vapor; down outerwear, the most. Vapor concentration near the clothing often increased for several minutes after the clothing was removed from the contaminated environment. Compression of thick outerwear released additional vapor. Mean times to reach 0 ranged from 7 minutes for jeans to 42 minutes for down jackets. Conclusions:, This simulation model of chemical vapor release demonstrates persistent presence of simulant vapor over time. This implies that chemical vapor may be released from the victims' clothing after they are evacuated from the site of exposure, resulting in additional exposure of victims and emergency responders. Insulated outerwear can release additional vapor when handled. If a patient has just moved to a vapor screening point, immediate assessment before additional vapor can be released from the clothing can lead to a false-negative assessment of contamination. [source] Spatial Patterning of the , -Phase in Poly(9,9-dioctylfluorene): A Metamaterials-Inspired Molecular Conformation Approach to the Fabrication of Polymer Semiconductor Optical StructuresADVANCED FUNCTIONAL MATERIALS, Issue 20 2009Gihan Ryu Abstract Materials in which sub-wavelength physical structures, rather than variations in chemical composition, are used to modify the nature of their interaction with electromagnetic radiation form the promising new class of metamaterials. For molecular materials one has an intriguing alternative, namely structuring the conformation or physical geometry of the molecule. In order for this to be an effective methodology one needs the change in conformation i) to engender a significant change in electromagnetic properties and ii) to be spatially controllable to allow patterning of practical structures. In this paper the potential of such an approach is demonstrated through spatial patterning, via masked solvent vapor exposure, of the , -phase conformation in poly(9,9-dioctylfluorene) (PFO). Significantly the conformation change approach preserves a planar film format and is found not to negatively impact on optical gain properties, both very attractive features for optoelectronic and photonic lightwave circuit applications. As a specific demonstration the ability to spatially control the lasing wavelength for samples in which a , -phase conformation is selectively patterned in a glassy PFO film spin coated atop a one-dimensional distributed-feedback grating etched into a spectrosil substrate is shown. [source] Operant Behavior and Alcohol Levels in Blood and Brain of Alcohol-Dependent RatsALCOHOLISM, Issue 12 2009Nicholas W. Gilpin Background:, The purpose of the present investigation was to more clearly define blood-alcohol parameters associated with alcohol dependence produced by alcohol vapor inhalation and alcohol-containing liquid diet. Methods:, Alcohol levels in blood and brain were compared during and after 4 hours of acute alcohol vapor exposure; also, brain-alcohol levels were assessed in alcohol-exposed (14-day alcohol vapor) and alcohol-naïve rats during and after 4 hours of acute alcohol vapor exposure. A separate group of rats were implanted with i.v. catheters, made dependent on alcohol via vapor inhalation, and tested for operant alcohol responding; blood-alcohol levels (BALs) were measured throughout operant alcohol drinking sessions during alcohol withdrawal. A final group of rats consumed an alcohol-liquid diet until they were dependent, and those rats were then tested for operant behavior at various withdrawal time points; BALs were measured at different withdrawal time points and after operant sessions. Results:, Blood- and brain-alcohol levels responded similarly to vapor, but brain-alcohol levels peaked at a higher point and more slowly returned to zero in alcohol-naïve rats relative to alcohol-exposed rats. Alcohol vapor exposure also produced an upward shift in subsequent operant alcohol responding and resultant BALs. Rats consumed large quantities of alcohol-liquid diet, most of it during the dark cycle, sufficient to produce high blood-alcohol levels and elevated operant alcohol responding when tested during withdrawal from liquid diet. Conclusions:, These results emphasize that the key determinants of excessive alcohol drinking behavior are the BAL range and pattern of chronic high-dose alcohol exposure. [source] Remission and Resurgence of Anxiety-Like Behavior Across Protracted Withdrawal Stages in Ethanol-Dependent RatsALCOHOLISM, Issue 9 2007Yu Zhao Background:, Alcohol dependence is a chronic disorder in which withdrawal symptoms often persist after detoxification. The purpose of the present experiment was to characterize susceptibility to stress and anxiogenic stimuli in rats over an extended time period following ethanol withdrawal. Methods:, Male Wistar rats were made dependent via ethanol vapor exposure. The rats were then tested in the elevated plus-maze during acute ethanol withdrawal (ACW, ,8 hour), early "protracted" withdrawal (EPW, 2 weeks), or late "protracted" withdrawal (LPW, 6, 12 weeks) following brief restraint or no stress. Principal components analysis was used to identify constructs underlying plus-maze behavior. Results:, Three factors characterized plus-maze performance: anxiety, locomotor activity, and risk assessment/decision making. Spontaneous anxiety-like behavior was increased during ACW, decreased to levels of ethanol-naïve controls during EPW, but markedly resurged during LPW. Withdrawal did not alter sensitivity to the anxiety-like effects of restraint stress. All ethanol-dependent rats showed locomotor hypoactivity that, in contrast to anxiety, remained stable throughout all withdrawal stages. Neither ethanol withdrawal nor restraint stress altered mean "risk assessment/decision making" scores, though ethanol withdrawal altered the emission of "risk assessment/decision making" behavior in relation to anxiety-like behavior and behavioral activation state. Conclusions:, The findings illustrate and model the spontaneous, severe, and long-lasting nature of behavioral abnormalities that accompany withdrawal from chronic, intermittent ethanol intoxication. The dynamic remission and resurgence in symptoms of negative affect (i.e., behavioral signs of anxiety) during "protracted" withdrawal may complicate recovery from alcoholism. [source] Disruptions in Sleep Time and Sleep Architecture in a Mouse Model of Repeated Ethanol WithdrawalALCOHOLISM, Issue 7 2006Lynn M. Veatch Background: Insomnia and other sleep difficulties are perhaps the most common and enduring symptoms reported by alcoholics undergoing detoxification, especially those alcoholics with a history of multiple detoxifications. While some studies have reported sleep disruptions in animal models after chronic ethanol exposure, the reports are inconsistent and few address sleep architecture across repeated ethanol exposures and withdrawals. The present study evaluated sleep time and architecture in a well-characterized mouse model of repeated chronic ethanol exposure and withdrawal. Methods: C57BL6/J mice were fitted with electrodes in frontal cortex, hippocampus, and nuchal muscle for collection of continuous electroencephalogram (EEG)/electromyogram (EMG) data. Baseline data were collected, after which mice received 4 cycles of 16-hour exposure to alcohol (ethanol: EtOH) vapor separated by 8-hour periods of withdrawal or similar handling in the absence of EtOH vapor. Ethanol-exposed mice attained a blood ethanol concentration of 165 mg%. Upon completion of vapor exposure, EEG/EMG data were again collected across 4 days of acute withdrawal. Data were subjected to automated analyses classifying 10-second epochs into wake, non,rapid eye movement (REM) sleep, or REM sleep states. Results: Mice in withdrawal after chronic EtOH exposure showed profound disruptions in the total time asleep, across the acute withdrawal period. Sleep architecture, the composition of sleep, was also disrupted with a reduction in non-REM sleep concomitant with a profound increase in REM sleep. While altered sleep time and non-REM sleep loss resolved by the fourth day of withdrawal, the increase in REM sleep ("REM rebound") persisted. Conclusions: These results mirror those reported for the human alcoholic and demonstrate that EtOH withdrawal,induced sleep disruptions are evident in this mouse model of alcohol withdrawal,induced sensitization. This mouse model may provide mechanisms to investigate fully the high correlation between unremitting sleep problems and increased risk of relapse documented clinically. [source] Enhanced Prepulse Inhibition Following Adolescent Ethanol Exposure in Sprague-Dawley RatsALCOHOLISM, Issue 10 2005Craig J. Slawecki Abstract: Objectives: Recent studies have demonstrated that ethanol exposure differentially affects adolescents and adults. The current studies were designed to compare the effects of 2-week exposure to ethanol during adolescence or adulthood on the acoustic startle response (ASR) and prepulse inhibition (PPI) Methods: Male Sprague-Dawley rats were exposed to ethanol vapor 12 hr/d (on from 6 pm to 6 am) for 14 days during adolescence or adulthood. Six days after the cessation of ethanol vapor exposure, the ASR and PPI were assessed. Results: During ethanol treatment, overall blood alcohol levels averaged 230 to 250 mg/dl in the adolescent and adult treatment groups. Assessment of the ASR revealed that latency to startle was more rapid in adolescents than in adults, but ASR latency was not altered by ethanol exposure. In addition, ASR magnitude was lower in adolescents and was decreased in ethanol-exposed rats on startle trials. Ethanol exposure significantly enhanced PPI, but only after adolescent exposure Conclusions: These data further demonstrate a differential sensitivity of adolescents and adults to the effects of ethanol exposure. Specifically, a 2-week period of ethanol exposure during adolescence selectively enhanced PPI, a neurobehavioral index of sensorimotor gating. However, ASR magnitude was decreased by ethanol exposure regardless of age. On the basis of previous studies, the effects of ethanol exposure on PPI data could indicate that adolescent rats exposed to ethanol are more likely to exhibit behavioral inflexibility and that ethanol exposure acts as a more potent physical stressor in adolescent rats. [source] Effects of Neuropeptide Y on Appetitive and Consummatory Behaviors Associated With Alcohol Drinking in Wistar Rats With a History of Ethanol ExposureALCOHOLISM, Issue 4 2005Annika Thorsell Background: Neuropeptide Y (NPY) reduces ethanol intake under free access conditions in Wistar rats with a history of prolonged ethanol vapor exposure. The current study was designed to determine whether NPY differentially alters ethanol-associated appetitive behavior (i.e., lever pressing) or ethanol consumption in Wistar rats with a history of ethanol vapor exposure. Methods: Wistar rats were first trained to self-administer 10% ethanol in a paradigm that provided 25 min of free access to 10% ethanol after completing a 20,lever press response requirement (i.e., an RR20 schedule). After stable level lever pressing was established, operant sessions were suspended during a 9-week period of ethanol vapor exposure. Self-administration sessions were then reinstituted, and a fixed time (FT) schedule of 10% ethanol access was used to assess the effects of ethanol exposure and NPY on lever pressing and drinking behavior. Under the FT schedule, the maximum number of lever presses emitted within 10 min was assessed before providing access to 10% ethanol. Results: Ethanol vapor exposure did not alter patterns of lever pressing under the RR20 schedule, but lever presses emitted under the FT schedule were reduced after ethanol vapor exposure. Ethanol intake was significantly increased after ethanol vapor exposure. NPY significantly reduced ethanol intake but did not significantly reduce lever pressing under the FT schedule. Conclusions: Taken together, these data suggest that chronic ethanol exposure increases ethanol intake without clearly enhancing its reinforcing value. Furthermore, NPY has a greater impact on the consummatory factors mediating ethanol intake than appetitive factors mediating ethanol seeking. [source] | ||||||||||