Physically dependent stimuli

Physically dependent stimuli include a wide range of variables such as temperature and mechanical deformation, amongst others. However, thermo-responsive polymers are the most relevant class of smart polymers studied because of their enormous variety and their great potential for different biomedical applications. Usually these polymers have both hydrophilic and hydrophobic phases, and undergo abrupt changes in their electrostatic and hydrophobic interactions in an aqueous medium at a critical solution temperature. 

Negus SS Woods JH (1995). Reinforcing effects, discriminative stimulus effects, and physical dependence liability of buprenorphine. In Cowan A Lewis JW (eds.) Buprenorphine Combatting Drug Abuse with a Unique Opioid. New York Wiley-Liss, pp. 71-101... 

Khat produces effects similar to those of other monoamine stimulants, (i.e., increases in mental stimulation, physical endurance, elevated mood) (Widler etal. 1994 Kalix 1994 Brenneisen etal. 1990). Stimulus generalization occurs between cathinone, amphetamine, and cocaine, suggesting similar subjective effects (Huang and Wilson 1986). Similar to other monoamine stimulants, cathinone causes dose-dependent reductions in eating and body weight (Islam et al. 1990 Zelger and Carlini 1980). Oral cathinone increases sexual arousal in rats, but does not affect erectile or ejaculatory responses (Taha et al. 1995). 

Efficient gene delivery can also be mediated by chemically programmed polymers responding to artificial physical stimuli like heat. Depending on the stimulus, they have the ability to alter their conformation in so far as transfection enhancing effects are initiated. 

The specific Ca channel antagoni.sts verapamil, nifedipine, and diltiazem interact at specific sites on the calcium channel protein. These blockers do not occlude the channel physically but bind to sites in the channel, as they can promote both channel activation and antagonism. AITiniiy fix binding sites on the channel varies, depending un the status of the channel. The channel can exist in either an open (0. re.sting (R). or inactivated (I) state, and the equilibrium lx-, tween them is determined by stimulus frequency and mem-... 

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