Habituating drugs

Short, W.F. and Hobday, G.l U.S. Patent 2,464,203 March 15, 1949 assigned to Boots Pure Drug Company Limited, England  [c.480]

Origin. Individual IDPs are short-Hved and the long-term presence of dust in the solar system implies that there must be sources capable of generating the approximately 10 kg/s of new dust required to balance losses by coUisions, ejection by radiation pressure, and spiraling into the Sun owing to the Poynting-Robertson effect. For sizes >10 fim, it has long been known that comets and asteroids are the principal source. Particles are Hberated from asteroids by coUisions of both asteroids and asteroid debris. Whereas coUision velocities are high, most of the Hberated dust is not strongly modified by the coUision process and is ejected with a space velocity close to that of the more massive of the two colliding bodies. Dust in the asteroid belt has been detected by its thermal emission in the infrared at wavelengths >10 fim. The orbiting IRAS infrared telescope discovered dust bands in the asteroid belt that correlate with the principal coUisionaUy-produced asteroid families (21) (see Infrared TECHNOLOGY and raman spectroscopy). Dust generated in the asteroid belt undergoes orbital decay owing to light pressure drag and spirals toward the Sun reaching the Earth on relatively low velocity orbits. Dust from comets is released when solar heating sublimes the ice matrix in comets. Dust is ejected, and because of the effects of light-pressure drag and ejection velocity, it forms the dust tail than can extend to lengths of over 10 km. Most of the comet dust that is coUectable on Earth is beHeved to have been derived from the Kuiper belt comets that reside in a flattened distribution extending from the region of the outer planets to distances of a few 100 AU from the Sun. At the time of dust release these bodies have evolved to short-period comets whose orbits pass close to the Sun. Dust from these comets reaches the Earth on relatively high velocity eccentric orbits. The dust from both comets and asteroids is beHeved to be samples of early solar system materials that has been relatively weU preserved over the age of the solar system inside moderately smaU bodies.  [c.101]

Nonreceptor-Mediated Drug Action. At least one important class of dmgs, the general anesthetics (qv), has been assumed not to owe its therapeutic activities to a specific receptor process. Anesthetic potency shows an excellent linear correlation with partition coefficient and this has been extrapolated to a definition of action at a Hpid site. The phosphoHpids of cell membranes, particularly nerve cells, have been considered as principal targets for general anesthetic action. It has been hypothesized that anesthetics may dismpt phosphoHpid stmcture by fluidizing or expanding the cell membrane or by altering the phase relationships of the phosphoHpids (53,54). However, it is possible that anesthetics bind to hydrophobic sites on proteins and thus affect directly excitable cell behavior (53—55). This latter proposal is consistent both with the activity of the gaseous general anesthetics and with the activity of stmcturaHy more complex agents, eg, 3a-hydroxy-5a-pregnane-ll,20-dione, 3a-hydroxy-5-pregn-16-ene-ll,20-dione, and l,5-desmethyl-5-cyclohexenylbarbituric acid.  [c.277]

Microemulsions, temporary emulsions, that is, two-layer haH dressHigs, and clear solutions of nonvolatile lubricants are on the market. HaH tonics, usually hydro-alcohoHc, achieve similar effects by including Hpid substances or synthetic em ollients, such as the mono butyl ethers of polypropylene oxides [9003-13-8] (10—50 mol). The primary benefits of these Hpid-based products are lubrication and improvements Hi haH gloss and hair-hoi ding (dressHig)  [c.300]

Apart from ReFs, which is produced when ReFg is reduced by tungsten wire at 600° C, all the known penta-, hexa- and hepta- halides of Re and Tc can be prepared directly from the elements by suitably adjusting the temperature and pressure, although various specific methods have been suggested. They are volatile solids varying in colour from pale yellow (ReF7) to dark brown (ReBrs), and are readily hydrolysed by water with accompanying disproportionation into the comparatively more stable [M04] and MO2, e.g.  [c.1052]

See pages that mention the term Habituating drugs : [c.100]    [c.508]    [c.124]    [c.569]    [c.791]   
Thin-layer chromatography Reagents and detection methods (1990) -- [ c.76 ]