Biological condition

Tetrahydroharman, m.p. 179-80°, has been prepared by a number of workers by a modification of this reaction, viz., by the interaction of tryptamine (3-)5-aminoethylindole) with acetaldehyde or paraldehyde and Hahn et al. have obtained a series of derivatives of tetrahydronorharman by the use of other aldehydes and a-ketonic acids under biological conditions of pH and temperature, while Asahina and Osada, by the action of aromatic acid chlorides on the same amine, have prepared a series of amides from which the corresponding substituted dihydronorharmans have been made by effecting ring closure with phosphorus pentoxide in xylene solution. 

It seems quite obvious that the thiophenes are related to the polyacetylenes which they accompany. This viewpoint has recently been illustrated by the formation of thiophenes from polyacetylenes and hydrogen sulfide under almost biological conditions. In a recent lecture summary, the preparation of terthienyl, junipal, and (241) from 1,4-disubstituted butadiynes and hydrogen sulfide is claimed. A large number of bithienyls have been prepared and their nemato-dicidal activity investigated. All the compounds with strong activity were found to be derivatives of 2,2 -bithienyl. ... 

Studies on the biosynthesis of prostaglandins revealed that a strained bicyclic bis(secondary-alkyl) peroxide was not only a key intermediate, but could survive the biological conditions long enough to be isolated, albeit in minute amounts. This was a startling discovery in that no simple bicyclic peroxides of the same type were known, clearly for reasons of preparative difficulty. The prostaglandin connection focused attention upon this missing class of peroxides and stimulated... 

Whatever its previous history before disposal and deposition at a site, the alteration of bone buried or exposed to the elements is determined, mainly, by the combined effect of the physical, chemical, and biological conditions at the site where it is deposited these include the seasonal characteristics, average temperature, relative humidity, amount and flow motion of water, pH value, extent of aeration, and the nature of the microorganism population (Millard 2001 White and Hannus 1983). 

D-fructose (4370 M"1) > D-galactose (276 M"1) > D-glucose (110 M"1). From these results, it was confirmed that the PMBV/PVA hydrogel was formed under biological conditions, and that the reversible properties of the hydrogel corresponded to the formation of a complex between the phenylboronic acid group in PMBV and the diol moiety in PVA. 

The rate constant of electron transfer (ks) and anodic and cathodic electron transfer coefficients (aa and ac) of the SODs at various pH values were estimated with Laviron s equation and summarized in Table 6.5. Interestingly, the fastest electron transfer of the SODs was essentially achieved in a neutral solution, probably in agreement with the biological conditions for the inherent catalytic mechanisms of the SODs for 02" dismutation, although the electrode processes of the SODs follow a different mechanism. 

Under biological conditions, the thermodynamic end-point (the ultimately most stable form of the element) is perrhenate, which is rapidly excreted by the kidneys. This is in contrast to, for example, 13II and 90Y, which thermodynamically tend towards, respectively 1 (which accumulates in thyroid) and solvated Y3+ (which accumulates in skeleton) each of these constitutes a radiological hazard to nontarget tissues. 

Using the concentrations and pressures provided we can calculate the Gibbs energy for the combustion of glucose under biological conditions. First, we need to replace the activities by the appropriate effective concentrations. That is,... 

Thus, intramolecular activation (cyclization-elimination) in this series is modulated by steric factors. In addition, hydrolysis may be enzyme-catalyzed, depending on substrates and biological conditions. 

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