The capability of a soft drink or a juice to erode dental enamel depends not only on the pH of the drink, but also on its buffering effect. As the latter is the ability of the drink to resist a change of pH it may add to the effects of the actual pH. The aim of the present study was to compare the pH and the buffering effect of various soft drinks with their erosive effects and the solubility o...

Exposure to high pCO2 or low pH alters sensation and behaviour in many marine animals. We show that crab larvae lose their ability to detect and/or process predator kairomones after exposure to low pH over a time scale relevant to diel pH cycles in coastal environments. Previous work suggests that acidification affects sensation and behaviour through altered neural function, specifically the ac...

The existence of pH optima for proteolysis was early established, primarily through measurements of the initial rate of reaction as a function of pH. When synthetic substrates for proteolytic enzymes were discovered, it was found that the rate of digestion depended upon the amino acids of the peptide and their arrangement in the chain. We have investigated the effect of pH upon the hydrolysis o...

The interactions of gallic acid and tannic acid with purified brush border sucrase (EC 3.2.1.48) from mouse intestine have been studied. These findings indicate that both gallic acid and tannic acid inhibit sucrase activity, which is pH dependent. Kinetic analysis revealed that enzyme inhibition by gallic acid is a pure V effect at pH 5.0, which changes to mixed type at pH 7.2, and pure K effec...

The effect of pH on functional association of peptide antigens with APC membranes was investigated by using aldehyde-fixed B cells and class II-restricted T cell hybridomas to assess antigen/MHC complex formation. The results indicated that the rate and extent of functional peptide binding was markedly increased at pH 5.0 as compared with pH 7.3. The pH dependence of binding was preserved after...

By J. V. DAdE, M.B., M.R.C.P. LONDON H YDROGEN ion concentration has a controlling effect upon many hemolytic systems, both simple and complex. Osbor& in 1934 reviewed the early literature on the effect of pH on the hemolysis by complement of corpuscles sensitized by hemolytic immune body. He found that the optimum reaction for the hemolysis of sheep corpuscles by guinea pig serum was about pH ...

Well-crystallized flower-shaped copper oxide nanostructures composed of thin leaves have been synthesized by simple low-temperature chemical bath method and used to fabricate pH sensors. We examined the effect of the pH on the growth of the CuO nanostructures. By changing the pH of the precursor solution different morphologies of the CuO nanostructures were obtained. CuO nanoflowers have recent...

With slices of various guinea pig tissues suspended in bicarbonate-free horse serum adjusted to various pH values, Canzanelli et al. (1) found that maximum rates of oxygen uptake occurred in all cases in media with pH values well above 7.4. With brain slices, the curve relating respiration rate to the pH of the medium rose with increasing pH, rapidly up’to pH 6, less rapidly from 6 to 8, and th...