5-s schedule in rats. The current investigation evaluated whether nicotine-associated contextual cues can produce nicotine-like perturbations in DRL-schedule performance in the absence of nicotine. Nicotine and saline administrations occurred

just prior to DRL 29.5-s schedule responding for sucrose solution, selleck compound library and two different experimental contexts (differentiated by visual, olfactory, and tactile cues) were utilized. All subjects (N=16) experienced two consecutive sessions of DRL-schedule responding per day. The experimental group (n=8) was exposed to saline immediately prior to the first session and 0.3 mg/kg nicotine before the second session, and the context was changed between sessions. This sequence of saline and then nicotine administration, paired with two reliable contexts, persisted for 12 consecutive days and successive nicotine administrations corresponded with increasingly poorer performance on the DRL 29.5-s schedule. No nicotine was administered for days 13-20 during context testing, and the nicotine-associated context produced response disinhibition on the DRL schedule. Two control groups were included in the design; subjects in one control group (n=4) received saline in each context to verify that the contexts themselves were not exerting control over operant responding. To assess how explicit and non-explicit pairings of nicotine and contextual cues influenced DRL behavior, subjects in a second control

group (n=4) were given nicotine prior to the second session, but the contexts were not altered between sessions. The results from this selleckchem experiment suggest that environmental stimuli associated with nicotine exposure can come to elicit nicotine-induced performance decrements on a DRL 29.5-s schedule. (C) 2009 Elsevier

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“Two diazo-coupling novolac derivative resins (carbonyl phenyl azo novolac resin and carbonyl phenol-biphenylene azo novolac resin) were used as flame retardants. The cured resins exhibited elevated glass-transition temperatures from 115 degrees C (blank) to 195 and 167 degrees C, respectively. The char yield at 800 degrees C was increased, which elaborated the effectiveness of flame retardancy with evaluated limiting oxygen indices around 36 to 40. This was mainly attributed to the increased crosslink densities and highly aromatic contents in the modified phenol novolac derivative resins, which exhibited higher thermal degradation energies. Furthermore, the more effective flame retardancy was expected because of the loss of nitrogen during combustion. Through the evaluation of the cooperative flame retardancy in the organic/inorganic hybrid with char yield and increasing limiting oxygen index percentage, the effects of the filler showed cooperative flame retardancy only with the appropriate addition and with a difference in the crosslinking densities. (C) 2009 Wiley Periodicals, Inc.