Reservoir effect

Hall BL, Henderson GM (2001) Use of TIMS uranium-thorium dating to determine past reservoir effects in lakes Two examples from Antarctica. Earth Planet Sci Lett 193 565-577 Hamelin B, Bard E, Zindler A, Fairbanks RG (1991) " U/ U mass spectrometry of corals How accurate is the U-Th age of the last interglacial period. Earth Planet Sci Lett 106 169-180 Hanebuth T, Stattegger K Grootes PM (2000) Rapid flooding of the Sunda Shelf a late-glacial sea-level record. Science 288 1033-1035... 

Methotrexate—use 75% dose for CrCI < 50 50% dose if CrCI < 25 do not give if patient has an effusion ( reservoir effect )... 

Figure 7.3. The reservoir effect. Examples of a ML catalyst with partial heterochiral dimerization into an inactive meso complex, giving rise to a (+)-NLE.

Lacustrine ecosystems, due to reservoir effects that are particular to individual water bodies, can show remarkable variation, potentially overlapping with both marine and terrestrial values. The reservoir effect applies to some extent also to smaller circumscribed seas such as the Mediterranean. 

In terms of the mechanisms of action, the pyrrolidones partition well into human horny layer. They may act by altering the solvent nature of the membrane and pyrrolidones have been used to generate reservoirs within skin membranes. Such a reservoir effect offers potential for sustained release of a permeant from the stratum corneum over extended time periods. However, as with many other potential enhancers, clinical use of pyrrolidones is problematic due to adverse reactions. An in vivo vasoconstrictor bioavailability study demonstrated that pyrrolidones caused erythema in some volunteers, although this effect was relatively short-lived. Also, a toxic hygroscopic contact reaction to NMP has been reported recently [21]. 

The asymmetric amplification is a consequence of an in situ increase in the ee of the active catalyst, since racemic ligand is trapped in the unreactive or weakly reactive meso catalyst. In the reservoir effect a similar phenomenon occurs outside the catalytic cycle. Let us assume that part of the initial chiral ligand, characterized by eeaux, is diverted into a set of catalytically inactive complexes (Scheme 12). 

Scheme ]3. Reservoir effect in the DAIB-catalyzed addition of diethylzinc to benzaldehyde.32...

Asymmetric amplification in the diethylzinc addition to aldehydes has been observed with many (3-amino alcohols as catalyst, presumably because of a reservoir effect similar to that discovered by Noyori et al. Asymmetric amplification has also been found for other classes of chiral catalysts—diamines, diols, titanium complexes, etc. The various examples are collected in Table 1. The... 

Loden, M. et al., The irritation potential and reservoir effect of mild soaps, Contact Dermatitis, 49, 91,... 

Rao BM, Driver I, Lauffenburger DA, Wittrup KD. Interleukin 2 (IL-2) variants engineered for increased IL-2 receptor alpha-subunit affinity exhibit increased potency arising from a cell surface ligand reservoir effect. Mol Pharmacol 2004 66 864-9. 

It has been reported in an ocular pharmacokinetic study of cyclosporin A incorporated in deoxycholic acid-based anionic and stearylamine-based cationic emulsions in rabbit that, when compared to anionic emulsion, the cationic emulsion showed a significant drug reservoir effect of more than 8 h in corneal and conjunctival tissues of the rabbit eye following topical application [106], Since cornea and conjunctiva are of anionic nature at physiological pH [107], the cationic emulsion would interact with these tissues electrostatically to implicate the observed cyclosporin A reservoir effect. This hypothesis is supported, in principle, by an ex vivo study which showed that cationic emulsion carrier exhibited better wettability properties on rabbit cornea than either saline or anionic emulsion carrier [108],... 

When compared to either saline or anionic emulsions, the nanosized cationic emulsions were shown to enhance the ocular bioavailability of indomethacin [108], piroxicam [178], and cyclosporin A [106,179] following one single-drop dose instillation into the rabbit eye (Figure 4). A significant drug reservoir effect was noted in the cornea and conjunctiva even for more than 8 h following the instillation [106],... 

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