Inhibitors measurement

J. Cossar and J. Carlile. A new method for oilfield corrosion inhibitor measurement. In Proceedings Volume. Annu NACE Corrosion Conf (Corrosion 93) (New Orleans, LA, 3/7-3/12), 1993. [Pg.374]

Although the inhibition-based biosensors are sensitive, they are poor in selectivity and are rather slow and tedious since the analysis involves multiple steps of reaction such as measuring initial enzyme activity, incubation with inhibitor, measurement of residual activity, and regeneration and washing. Biosensors based on direct pesticide hydrolysis are more straightforward. The OPH hydrolyzes ester in a number of organophospho-rus pesticides (OPPs) and insecticides (e.g. paraoxon, parathion, coumaphos, diazinon) and chemical warfare agents (e.g. sarin) [53], For example, OP parathion hydrolyzes by the OPH to form p-nitrophenol, which can be measured by anodic oxidation. Rainina... [Pg.60]

In order to increase the external validity of our models, it might be desirable to consider some nonnicotine ingredients of tobacco smoke. It appears that there are natural monamine oxidase (MAO) inhibitors in tobacco smoke (Lewis et al. 2007). It would be interesting to determine whether the coadministration of a low dose of a standard MAO inhibitor along with chronic nicotine would increase physical dependence, as assessed by various withdrawal measures, hi view of the antidepressant properties of MAO inhibitors, measures reflecting aspects of depression might be particularly affected. [Pg.426]

Effects of four Nib inhibitors measured in membrane preparations from unex.poscd cells 2-octyl-4H-L3.2-betizodioxophosphorin 2-otiide (OBDPO), ethyl octylphosphonofluoridatc (EOPF), tri-o-tolylphosphate (TOTP). and mipafox NTE activity measured in subconfluem cells treated in serum-free medium 4 hr with OBDPO or EOPF. [Pg.321]

Fig. 2 depicts an experiment in which the hepatic adenine nucleotides were labelled with [ C]adenine, prior to the isolation of the liver for perfusion. Coformycin was added to the recirculating medium at the beginning of the perfusion. This resulted in a tissue concentration of the inhibitor, measured after 30 min, equal to 2.5 x lo M. This concentration was previously shown to inhibit maximally hepatic adenosine deaminase, without influencing AMP deaminase (Van den Berghe et al., 1980). A release of radioactive uric acid and allantoin was measured in the... [Pg.465]

Brand, S. J., and Morgan, R. G. H., 1981, The release of rat intestinal cholecystokinin after oral trypsin inhibitor measured by bio-assay, J. Physiol., 319 325-343. [Pg.313]

Application of the CCM to small sets (n < 6) of enzyme inhibitors revealed correlations between the inhibitory activity and the chirality measure of the inhibitors, calculated by Eq. (26) for the entire structure or for the substructure that interacts with the enzyme (pharmacophore) [41], This was done for arylammonium inhibitors of trypsin, Di-dopamine receptor inhibitors, and organophosphate inhibitors of trypsin, acetylcholine esterase, and butyrylcholine esterase. Because the CCM values are equal for opposite enantiomers, the method had to be applied separately to the two families of enantiomers (R- and S-enantiomers). [Pg.419]

Since acrylic polymerizations liberate considerable heat, violent or mnaway reactions are avoided by gradual addition of the reactants to the kettie. Usually the monomers are added by a gravity feed from weighing or measuring tanks situated close to the kettie. The rate of monomer addition is adjusted to permit removal of heat with full flow of water in the condenser and a partial flow in the cooling jacket. Flow in the jacket can be increased to control the polymerization in cases of erroneous feed rates or other unexpected circumstances. A supply of inhibitor is kept on hand to stop the polymerization if the cooling becomes inadequate. [Pg.168]

Lubricants. Petroleum lubricants continue to be the mainstay for automotive, industrial, and process lubricants. Synthetic oils are used extensively in industry and for jet engines they, of course, are made from hydrocarbons. Since the viscosity index (a measure of the viscosity behavior of a lubricant with change in temperature) of lube oil fractions from different cmdes may vary from +140 to as low as —300, additional refining steps are needed. To improve the viscosity index (VI), lube oil fractions are subjected to solvent extraction, solvent dewaxing, solvent deasphalting, and hydrogenation. Furthermore, automotive lube oils typically contain about 12—14% additives. These additives maybe oxidation inhibitors to prevent formation of gum and varnish, corrosion inhibitors, or detergent dispersants, and viscosity index improvers. The United States consumption of lubricants is shown in Table 7. [Pg.367]

Because the chemiluminescence intensity can be used to monitor the concentration of peroxyl radicals, factors that influence the rate of autooxidation can easily be measured. Included are the rate and activation energy of initiation, rates of chain transfer in cooxidations, the activities of catalysts such as cobalt salts, and the activities of inhibitors (128). [Pg.269]

The proposed pathway for the biosynthesis of the avermectins (Fig. 3) has been described in a review (23). Some of the details are yet to be elucidated, although the steps, in general, are based on firm evidence from four types of studies incorporation of labeled precursors, conversion of putative intermediates by producing strains and blocked mutants, in vitro measurement of biosynthetic enzymes, and studies with enzyme inhibitors. The biosynthesis of the oleandrose units was elucidated from studies using and labeled glucose, which indicated a direct conversion of glucose to... [Pg.281]

Petroleum greases and oils can be excellent corrosion inhibitors on a variety of alloys. The hydrophobic layer produced by oil or grease can prevent water from contacting surfaces and can, therefore, almost eliminate corrosion. Unfortunately, the addition of oil and grease cannot be recommended as a corrosion-reduction measure in cooling water systems for three basic reasons. [Pg.78]

At the molecular level, microcystins are potent inhibitors of protein phosphatases 1 and 2A. The activity of protein phosphatases can be determined by measuring... [Pg.116]

An enzymatic assay can also be used for detecting anatoxin-a(s). " This toxin inhibits acetylcholinesterase, which can be measured by a colorimetric reaction, i.e. reaction of the acetyl group, liberated enzymatically from acetylcholine, with dithiobisnitrobenzoic acid. The assay is performed in microtitre plates, and the presence of toxin detected by a reduction in absorbance at 410 nm when read in a plate reader in kinetic mode over a 5 minute period. The assay is not specific for anatoxin-a(s) since it responds to other acetylcholinesterase inhibitors, e.g. organophosphoriis pesticides, and would need to be followed by confirmatory tests for the cyanobacterial toxin. [Pg.117]

Add an inhibitor to stop the reaction. This measure requires intimate knowledge of how the reaction rate can be influenced and whether effective mixing/inhibition is possible. [Pg.46]

The second level of interaction, the intermediate-dose level, can result in measurable effects on forest ecosystems. These effects consist of a reduction in forest growth, change in forest species, and susceptibility to forest pests. Both laboratory investigations and field studies show SO2 to be an inhibitor of forest growth. When various saplings have been exposed to SO2 in the laboratory, they show reduction in growth compared with unexposed... [Pg.117]

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