Unexplained observations

The vastly increased acidity of superacidic systems resulted in the significant new field of superacid chemistry. I began to ask myself whether a similar but more general approach could be used to produce electrophiles of greatly enhanced electron deficiency and thus reactivity. Over the years, there were a number of unexpected results in my own research work, as well as some previously unexplained observations buried in the literature, that seemed worth pursuing. 

A previously unexplained observation of a link between nose and gonads — the so-called naso-genital relationship — can now be placed in context. Removal of the relay site for the pump-regulator (see above) by extirpation of the sphenopalatine ganglion was found to result in a state of pseudo-pregnancy (Rosen et al, 1940). Interruption of stimulus access would clearly prevent most uptake through loss of control over the pump. A diestrous state would be induced (Sec. 5.3 below) attributable to the lack of male urinary semiochemicals. 

In the present paper this author did essentially the same as he had done in the work on the DP variations (Section 4.10), namely to develop a simple new theory to explain coherently a mass of disparate, apparently unconnected and unexplained observations. 

However, in patients with renal failure there is a strange and currently unexplained observation in relation to non-renal clearance. If this is measured for some compounds it also is found to be depressed even though it is the kidney that is diseased and not the liver The picture becomes a little clearer if the same non-renal (presumed hepatic) clearance is measured again in patients after renal dialysis when the hepatic clearance has been found to have risen to control values. Recent animal experiments have demonstrated that the circulating inhibitor of hepatic cytochrome P450 may be parathyroid hormone. Parathyroidectomy of rats with chronic renal failure prevented the reduction in liver cytochrome activity (see Michaud et al., 2006). 

The examples discussed above illustrate that reactivity and stereoselectivity are subject to numerous, often subtle, influences. Continuous improvements in molecular modeling have enabled clarification of many, previously unexplained observations in the future even solvent effects might, perhaps, be taken into account. Predictive models based on such calculations should, however, always be substantiated by experimental data. 

In the calyx of Held synapse in the auditory brainstem of rats the 5-HTib receptor inhibition of glutamate release was fully explained by inhibition of Ca2+ entry through voltage-dependent channels (Mizutani et al. 2006). In rat nucleus accumbens, in contrast, the analogous 5-HTib effect did not involve inhibition of Ca2+ channels (Muramatsu et al. 1998). In rat amygdala, the 5-HTia inhibition operated via a cyclic AMP pathway and apparently inhibition of Ca2+ entry an unexplained observation was the failure of pertussis toxin to abolish the 5-HTia inhibition (Cheng et al. 1998). 

This is consistent with the observation that at low [O], the NO emission intensity depended quadratically on [0]. An unexplained observation was that the NO emission increased with O atom concentration, passed through a maximum, and then declined with further increase in [O]. 

One unexplained observation of PSE is that no student ever erased an icon from the Student Work Area. Unwanted ones were simply left on the screen but never again used. 

The mechanism has only qualitative significance but it enables one to explain the experimental results more satisfactorily than the more often accepted models. Let us now use this new concept to interpret some of the until now unexplained observations. 

Tn the past few years considerable interest has developed in the struc- ture of water in electrolytic solutions (25). This renewed interest is the result of a number of extensive experimental investigations and the realization that many otherwise unexplainable observations can be accounted for if water is considered as a structured medium rather than as a continuum. This paper will consist of a review of some of the more recent advances that have been made in elucidating the factors determining the properties of electrolytes in aqueous solution. Transport properties will be dealt with almost exclusively since the author s main interests lie in that direction. Owing to the unique mechanism of proton conduction in aqueous solution, acids and bases will not be considered and the discussion will be limited exclusively to salt solutions. 

Summary of Further Studies. The experiments presented in the previous two sections afford a direct investigation of the conformation and orientation of Mb adsorbed on PDMS. These experiments can be used to clarify the results of the antibody experiments concerning the orientation and the deformation of adsorbed Mb. The experiments may also provide insight about certain as yet unexplained observations of Mb adsorption (19). 

Assay of Ribonuclease. Several kinds of assay have been found useful for studying ribonuclease (RNAase). A spectrophotometric assay is based on the empirical, unexplained observation that there is a decrease in optical density at 300 m/ during hydrolysis of RNA. RNA can be precipitated from solutions of its degradation products by uranyl acetate in trichloroacetic acid the soluble nucleotides can be measured spectro-photometrically or chemically. A manometric assay determines the formation of secondary acid groups through release of CO2 from a bicarbonate buffer acid groups have also been determined by titration. Recently cyclic nucleotides have been used as substrates in place of nucleic acid. ... 

The large majority of photochemical processes can, however, be easily seen to fall into the categories enumerated here and can consequently be explained in a very simple manner in terms of the PMO approach. This is an important achievement because the development of organic photochemistry has been bedeviled in recent years by an enormous outpouring of unexplained observations, most of which can be interpreted very simply in terms of the ideas presented here, including the following ... 

An important but yet unexplained observation is the lack of a direct relationship between the extent of inhibition of translation and the extent of phosphorylation of eIF-2. Thus, almost complete inhibition of translation can be observed when no more than 30% of the eIF-2 pool is phosphorylated (Leroux and London, 1982 Safer et al., 1977 Amesz et al., 1979). There are several possible explanations for this discrepancy. One hypothesis is that eIF-2B is present in limiting amounts and that phosphorylation of a minority of eIF-2 molecules is sufficient to tie up the entire eIF-2B pool, leaving none available to recycle as yet unphosphorylated eIF-2. Indeed, Matts et al. (1983) have found that phosphorylated eIF-2 forms a complex with eIF-2B that is not readily dissociable. Another possibility is that the phosphorylation of eIF-2 is not the primary cause for inhibition but occurs only when normal functioning of eIF-2 is prevented by other means. Evidence in favor of such an explanation is available for the very similar inhibitory effect on translation exerted by dsRNA (Rosen et al., 1981a see Section 7.2). Jagus and Safer (1981a,/ ) have reported that there are conditions in which eIF-2 is inactivated, but where there is no apparent change in its state of phosphorylation (see Section 7.4.1). 

As a summary, we have reviewed the main experimental results and concepts concerning the physical properties of the liquid crystals of bent-core molecules. We demonstrated that a number of seminal findings and basically new concepts emerged in the field in the last decade. However scientists regularly explore unusual , surprising and not understood phenomena, and there are more unexplained observations than well understood ones. We are completely sure that the next decade of the physics of bent-core liquid crystals will bring new physics, and will be as rich in beautiful observations as was the first decade. 

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