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Orexins (hypocretins) are hypothalamic neuropeptides that innervate the entire neuraxis, including the prelimbic cortex and ventral tegmental area and have been implicated in ethanol-seeking behaviour. The present study aimed to use the orexin-1 (OX1 ) receptor antagonist SB-334867 to examine the role of prelimbic cortex and ventral tegmental area OX1 receptors in cue-induced reinstatement of ethanol-seeking. Ethanol-preferring rats (iP) rats were trained to self-administer ethanol (10 percent v/v, FR3) or sucrose (0.2-1 percent w/v, FR3) in the presence of reward-associated cues before being implanted with indwelling guide cannulae. Rats then underwent extinction training for 11 days. On test days, rats were given a microinjection of vehicle or SB-334867 (3 μg/side) and presented with reward-associated cues to precipitate reinstatement. Results show SB-334867 infused into the prelimbic cortex attenuated cue-induced reinstatement of ethanol-seeking, but not sucrose-seeking. OX1 antagonism in the ventral tegmental area also attenuated cue-induced reinstatement of ethanol-seeking. These findings suggest that OX1 receptors located in the prelimbic cortex and ventral tegmental area are part of a circuit driving cue-mediated ethanol-seeking behaviour.

Background: Although disulfiram has been used in the treatment of alcoholism due to the unpleasant sensations its concomitant ingestion with ethanol provokes, some patients reported stimulant effects after its ingestion. This issue has not been addressed in studies with animals. In mice, the stimulant effect of ethanol has been associated with increased locomotor activity and behavioural sensitization. This study sought to analyze the influence of disulfiram on the development of behavioural sensitization to the stimulant effect of ethanol. Methods: Male Swiss mice pre-treated with vehicle or disulfiram (15 mg/kg) received saline or ethanol (2.0 g/kg) every other day, for 5 days. Forty-eight hours afterwards mice were challenged with Saline, and 48 h later they received Disulfiram, or Disulfiram + Ethanol or Ethanol. Results: The co-administration of disulfiram (15 mg/kg) blocked the development of behavioural sensitization induced by ethanol (2.0 g/kg). Although the acute administration of disulfiram did not alter the locomotor activity, its acute administration-induced higher levels of locomotor activity in mice previously sensitized to ethanol than in controls which received saline. Conclusions: Our data suggest that besides the known psychological effects (fear of aversive effects) disulfiram efficacy on alcohol dependency treatment could also be due to its pharmacological interference in the brain neurotransmission.

This paper describes both theoretical and experimental studies on the application of a portable water mist extinguisher in suppressing multiple fire types. Two prototype portable water mist fire extinguishers were developed and their feasibility in extinguishing flammable liquid, cooking oil and wood crib fires, and for use in fires associated with an energized target was investigated. The interaction between water mist and the fire plume was studied by analyzing the instantaneous process of fire extinction, and fire and fuel temperature profiles. Both theoretical analysis and experimental results showed that the extinguishing mechanisms and process as well as water mist characteristics required (such as water flux density, droplet size and spray coverage) change with the types of fires encountered. The portable water mist extinguisher with appropriate mist characteristics was able to extinguish multiple fire types.

A study was undertaken to address concerns of corrosion in an electronic environment after fire suppression using HFC-227ea (C3F7H). Fire suppression using halocarbon agents, such as HFC-227ea, can produce thermal decomposition products, e.g., hydrogen fluoride (HF), which may cause corrosion in electronic equipment. In this study, full-scale experiments were conducted in a simulated electronic equipment room using six steel cabinets under various ventilation conditions. An in-cabinet cable fire was used in the tests as a fire source and HFC-227ea was used to suppress the fire. FTIR spectrometers were used to measure the gases in the cabinets and room. The test results showed that cabinet ventilation conditions affected fire extinguishment times in the cabinet, and therefore the amount of HF generation. In the open cabinet cable fire test, the concentration of HF was below 100 ppm in the fire cabinet. In the closed cabinet cable fire test, the maximum concentration of the HF reached 800 ppm in the fire cabinet. The migration of gaseous by-products from the fire cabinet to the adjacent non-fire cabinets was minimal. A large heptane pool fire test was also conducted in the simulated electronic equipment room; the maximum HF concentration in the room for this test reached 3900 ppm, slightly greater than the 3800 ppm within an open cabinet. However, peak HF concentrations of 1800 ppm and 500 ppm were observed within the ventilated and closed cabinets, respectively, during the heptane test.

Handheld FM-200, FE-36, CF3I and Halotron I extinguishers with 2B:C, 5B:C and 10B:C ratings (or equivalent) were tested for extinguishing Class B heptane pool fires in small and large enclosures (45, 120 and 21000 m3). Test results showed that the Halotron I and CF3I extinguishers performed better than the FE-36 and FM-200 extinguishers. The concentrations of the halocarbons and acid gas by-products in the operator breathing zone and surroundings were measured during the tests. Measurements showed that the agent concentrations were below the levels that would pose life or health risk to the operator. The concentrations of acid gas by-products generated during suppression, however, were at dangerous levels in the small enclosures (45 and 120 m3). Heat flux towards the operator was also measured. Heat exposure presented a severe hazard to the operator during the pool fire suppression. Test results indicate some potentially hazardous conditions to an unprotected operator.

This paper describes water mist fire suppression effectiveness under various ventilation conditions. The full-scale fire test series were conducted in an empty enclosure and in a simulated machiner...

We conducted a series of full-scale fire tests of a twin-fluid water mist system in an empty enclosure and in a simulated machinery space. During the tests, two water mist discharge modes, continuous and cycling, were used. We investigated the extinguishment performance of the water mist system using these two discharge modes under various fire scenarios, including different fire sizes, types, and locations, and different ventilation conditions. Test results showed that use of the cycling discharge substantially improved the effectiveness of the water mist system for fire suppression, in comparison to the continuous discharge. The corresponding extinguishing time and water requirement for fire suppression were significantly reduced, and some fires that could not be extinguished with the continuous discharge were extinguished with the cycling discharge. The improvement in fire suppression was attributed to high depletion and dilution rate of oxygen and the recurrent dynamic mixing generated by the cycling water mist discharge in the compartment.

Previous investigations made into protecting glazing assemblies with dedicated sprinklers included protecting wide windows with multiple sprinklers, but they did not address protecting exterior glazing assemblies from external fire exposure with sprinklers. In addition to a summary of the previous work on protecting glazing assemblies with dedicated sprinklers, this paper describes the test set-up and discusses the test results that led to a sprinkler system recommendation for protecting exterior glazing assemblies from external fire exposures.

Background According to the incentive sensitization theory, addiction is caused primarily by drug-induced sensitization in the brain mesocorticolimbic systems. After repeated ethanol administration, some animals develop psychomotor sensitization, a phenomenon which occurs simultaneously with the incentive sensitization. Recent evidence suggests the involvement of norepinephrine (NE) in drug addiction, with a critical role in the ethanol reinforcing properties. In this study we evaluated the influence of an agonist (phenylephrine) and an antagonist (prazosin) of alpha1-adrenergic receptors on the development and expression of behavioral sensitization to ethanol. Male Swiss mice, previously treated with ethanol or saline, were challenged with the combined administration of ethanol (or saline) with alpha1-adrenergic drugs. Prazosin (0.1; 0.5 and 1.0 mg/kg) and phenylephrine (1.0 and 2.0 mg/kg) administration blocked the expression of behavioral sensitization to ethanol. In another set of experiments, mice treated with 0.5 mg/kg of prazosin + ethanol did not present the development of behavioral sensitization. However, when challenged with ethanol alone, they showed the same sensitized levels of locomotor activity of those presented by mice previously treated with ethanol and saline. Phenylephrine (1.0 mg/kg) treatment did not affect the development of behavioral sensitization. Based on this data, we concluded that the alteration of alpha1-adrenergic receptors functioning, by the administration agonists or antagonists, affected the locomotor sensitization to the stimulant effect of ethanol, suggesting that the normal functioning of the noradrenergic system is essential to its development and expression.