Absorption interactions

The extinction coefficient is dependent on the presence of gases and molecules that scatter and absorb light in the atmosphere. The extinction coefficient may be considered as the sum of the air and pollutant scattering and absorption interactions, as shown in Eq. (10-4) ... 

LF Prescott, WS Nimmo, RC Heading. Drug absorption interactions. In DG Grahame-Smith, ed. Drug Interactions. Baltimore Macmillan, 1977, p. 45. 

The electromagnetic radiation is absorbed by a molecule, which results in the radiation energy being transferred to the molecule this mode of interaction is termed resonant or absorptive interaction. 

Determination of human requirements for dietary trace minerals necessarily includes knowledge of the factors which affect the availability of minerals for absorption Interactions of dietary minerals with organic constituents of the diet and with other minerals are complex Careful study of mineral absorption in human subjects is required to delineate dietary requirements and the factors which affect them ... 

Absorption interactions involving altered gastrointestinal motility have been described. These include interactions of digoxin with propantheline (204), meto-clopramide (204), and cisapride (205). However, the chnical relevance of these interactions is unclear and they are probably unimportant. 

A. Mazzucotelli, F. Soggia, R. Frache, B. Cosma, Electrothermal atomic absorption interactions among trace and major elements in environmental samples determination of cadmium in the selective and total dissolution of marine sediments, Appl. Spectrosc., 45 (1991), 504-507. 

Fractionation of aquatic humic substances by adsorptive interactions has been the most successful method for fractionation as well as concentration and isolation. Humic solutes readily interact with various adsorptive surfaces without the requirement of crossing the interface surface as is necessary with solvent partitioning or absorptive interactions. 

Greenbiatt, D.J. Absorption interactions to improve bioavailability. Presentation 1279, program and abstracts of the 41st Interscience Conference on Antimicrobial Agents and Chemotherapy, Chicago, Illinois, December 16-19, 2001. 

Many of the interactions covered in this section concern absorption interactions, such as the ability of the tetracyclines and quinolones to chelate with divalent cations. More information on the mechanism of these interactions can be found in Drug absorption interactions , (p.3). 

Information appears to be limited to these single-dose and in vitro studies. The importance of this interaction in patients taking both drugs long-term awaits further study but the extent of the reductions in absorption (30 to 50%), and the hint of worsening control, suggests that this interaction may be of clinical importance. Be alert for any evidence of this. Separating the administration of the iron and levodopa as much as possible is likely to prove effective, as this appears to be an absorption interaction. More study is needed. 

Information is limited, but the absorption interaction appears to be established. The elinical importance awaits full evaluation but the modest effects on blood pressure and heart rate suggest that it is of limited importanee. Information about other beta blockers and penicillins is lacking. Information on potentiation of anaphylaxis is too limited to make comment, but note that some evidence suggests that anaphylactic shock in patients taking beta blockers may be resistant to treatment with adrenaline (epinephrine), see Beta blockers + Inotropes and Vasopressors , p.848. 

The various gastrointestinal drug groups covered in this section are listed in Table 27.1 , (see below). Drug absorption interactions , (p.3) discusses how absorption interactions occur and contains more detailed information on some of the mechanisms of interaction covered in this section. 

Not fully understood. Changes in gastric pH caused by the antacid, and retarded gastric motility have been suggested as potential mechanisms. An in vitro study showed no absorption interaction occurred between cimetidine and antacids. ... 

The manufacturers of alendronate suggest that, in order to avoid absorption interactions, patients should wait at least 30 minutes after taking alendronate before taking any other drug or food, and that alendronate should be taken with plain water only. 

Absorption Includes all neutron-nucleus reactions whose end products do not include a neutron and the original nucleus. The following processes are specifically included in the absorption interaction ... 

Evanescent wave In an ATR, a series of reflective absorptive interactions multiple internal reflections. 

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