Consequences Factors influencing effectiveness

Factors Influencing Effectiveness of Consequences. Two factors influence the effectiveness of consequences and delayed outcomes ... 

In Ugi four-component reactions (for mechanism, see Section 1.4.4.1.) all four components may potentially serve as the stereodifferentiating tool65. However, neither the isocyanide component nor the carboxylic acid have pronounced effects on the overall stereodiscrimination60 66. As a consequence, the factors influencing the stereochemical course of Ugi reactions arc similar to those in Strecker syntheses. The use of chiral aldehydes is commonly found in substrate-controlled syntheses whereas the asymmetric synthesis of new enantiomerically pure compounds via Ugi s method is restricted to the application of optically active amines as the chiral auxiliary group. 

In scrutinizing the various proposed reaction sequences in Eq. (26), one may classify the behavior of carbene complexes toward olefins according to four intimately related considerations (a) relative reactivities of various types of olefins (b) the polar nature of the metal-carbene bond (c) the option of prior coordination of olefin to the transition metal, or direct interaction with the carbene carbon and (d) steric factors, including effects arising from ligands on the transition metal as well as substituents on the olefinic and carbene carbons. Information related to these various influences is by no means exhaustive at this point. Consequently, some apparent contradictions exist which seem to cast doubt on the relevance of various model compound studies to conventional catalysis of the metathesis reaction, a process which unfortunately involves species which elude direct structural determination. 

Edaphic Factors. Soil texture, soil moisture and mineral nutrients strongly influence plant growth and, consequently, have an effect on susceptibility to air pollutants. Adequate soil moisture to maintain leaf turgidity is essential to maintain full... 

The coexistence of inhibitory and facilitatory adenosine- and P2-receptors in the same nerve terminal raises the question of which factors influence the concentration of endogenous agonists in the vicinity of each receptor (i.e., in the receptor biophase) and, consequently, determine the net modulatory effect. Tissue differences in receptor expression and purine release/formation or inactivation systems create a diversity of possibilities that makes the net modulatory effect by endogenous purines quite variable from tissue to tissue. 

In many cases, multiple biochemical pathways are activated by the intake of therapeutical drugs. The activation of side mechanisms coincides with the consequent side effects. This concept has led to research areas like polypharmacology as well as re-purposing studies. In such cases, the possibility of activating of multiple biochemical pathways is employed to explore alternative therapeutic uses of the same compound. In addition to the ligand-receptor process, it is necessary to take into consideration the other mechanistic features that might also be involved and affect the analysis, such as the metabolism, transport based on carry proteins, co-factors, influence of metals, etc. 

Ruggedness and Its Uncertainly. Ruggedness tests provide a means of simultaneously investigating the effect of several parameters on the performance of the method by the deliberate introduction of reasonable variations and the observation of their consequences. Factors that could potentially influence the results are identifled and are modifled by an amount to match the deviations that could reasonably occur within or between laboratory analyses. Examples include factors such as the analyst, the temperature, the source and age of reagents and analytical standards, the pH value at various steps, and the batch number of solvents or SPE cartridges. 

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