Paradoxical pulse

Crich D, Huang W (2001) Dynamics of alkene radical cations/phosphate anion pair formation from nucleotide C4 radicals. The DNA/RNA paradox revisited. J Am Chem Soc 123 9239-9245 Das S, Deeble DJ, Schuchmann MN, von Sonntag C (1984) Pulse radiolytic studies on uracil and uracil derivatives. Protonation of their electron adducts at oxygen and carbon. Int J Radiat Biol 46 7-9... 

Leydig cells have shown however, that exposure to low levels of LH delivered as a 10 min pulse every 2 h does desensitize the steroidogenic response [77]. Desensitization of the LH-induced cyclic AMP production and internalization of the LH receptor does occur with testis Leydig cells in vitro at physiological concentrations of LH and these processes paradoxically may be necessary to maintain the normal physiological response of the Leydig cell to LH [78]. 

Paradoxically, although chronic exposure to high PTH levels leads to bone decalcification, administration in pulses, as a once-a-day injection,... 

Arnell, R. and Fornstedt, T. (206) Validation of the tracer-pulse method for multicomponent liquid chromatography, a classical paradox revisited. Anal. 

High resolution NMR is a paradox - the natural NMR line in solid is broad and stmctureless. Only with the recent introduction of multiple pulse, magic angle spinning, cross polarization, and other techniques has it become possible to resolve finer details of nuclear spin interactions in solids. 

It is somewhat surprising in the light of this evidence that attempts to observe carrier transit have been unsuccessful [100 -102), After a short light pulse the photocurrent decays monoton-ically with no features attributable to carrier transit. Such a response, of the form t °, is in fact typical for amorphous materials an apparent paradox in view of the quality of the PDA crystals used. This problem has been resolved by recent theoretical and experimental work [103, 104). These show that the apparent anomaly is due to a breakdown in linear response theory. Carrier motion in ID in the presence of strong scattering centres is shown to be extremely sensitive to the density of scattering centres. 

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