Interactive deliberation: examples

The first example of the deliberate separation of optically active molecules is appropriate as an example of physical separation in the clearest sense of the term. The molecules are referred to as optically active because polarized light interacts differently with right- and left-handed molecules. In the case of simple diastereomers the RR and SS forms are enantiomers while the RS and SR forms are not. The separation of the latter and former was first done under a microscope using crossed polarizers and the crystals which were seen were separated from those that caused little or no rotation of plane-polarized light by hand using tweezers. A truly physical separation of chemical species using a physical property of chemical origin ... 

There are many examples of the deliberate use of chemical intuition and understanding of forces between molecules in getting selective interactions that enhance separation. An entire book could be written just cataloging examples. It is more appropriate here to give a few stationary phase examples. 

Often, in liquid-phase as well as in single-crystal NMR work, the samples are deliberately spun, often at special orientations (magic angle) relative to B. This will average out dipolar interactions, often narrowing the observed lines by substantial amounts. For example, see Ref. 3, Section 7.10 and Ref. 4, Chapter 8. Under some circumstances, additional lines (spinning sidebands) are generated by the MAS technique.32-34... 

Factors that put patients at risk of lithium intoxication are those that increase intake (deliberately or accidentally), reduce excretion (kidney disease, dehydration, low sodium intake, drug interactions), or reduce body water (dehydration secondary to fluid restriction, vomiting, diarrhea, or polyuria) (66). Patients with lithium-induced polyuria are at a particular risk of toxicity if their ability to replace fluids is compromised (for example by anesthesia, over-sedation, CNS trauma). 

In a retrospective study of 114 patients admitted to a toxicological ICU with suspected lithium intoxication, 81 had definite intoxication 78% were deliberate overdoses, and 22% were accidental (due, for example, to renal insufficiency, dehydration, drug interactions, poor compliance, drunkenness). Most were treated conservatively with gastric lavage and forced diuresis hemodialysis was used only in 3-6%. Two of those who took a deliberate overdose and one of those who took an accidental overdose died (535). 

Drug interactions akso are important for their influences on the reasons for and patterns of human drug use, so they are of central concern in this text. Individuals may intentionally combine drugs that have the same or similar action to achieve a super high or effect. Or individuals may use drugs that have opposite effects in a deliberate effort for one drug to modify the other. An example heard commonly in treatment... 

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