Sensitization, table cause

The same Pt/SiC catalysts were poisoned by CS2 the hydrogenation of (+)-apopinene was used as an indicator reaction (ref. 14). The amount of CS2 necessary to eliminate the hydrogenation activity permits calculation of the fraction of metal sites active in olefin hydrogenation. This fraction correlates with the number of step sites. Similarly, a good correlation is found between this fraction and the rate of methyloxirane transformation (Table 1). These results reveal that the structure-sensitivity is caused by the variation in the number of active sites, and the steps appear to be the active sites for the regioselective hydrogenation of methyloxirane. 

The use of ECD detection causes a small loss in sensitivity (Table 1), but a considerable loss in selectivity. Therefore, ECD can be used for screening of TCPM and TCPMe, but confirmation by GC/ECNI-MS or GC/EI-MS, respectively, will often be essential. 

Specifications and Standards. Typical specifications for phthahc anhydride are given in Table 10. AH specifications are measures of purity. Sohdification point is a sensitive indicator of absolute purity, and is a key specification. Another key specification is molten color stabiUty, which is the color after being held at 250°C for two hours. This test ensures acceptable color after shipment in molten form and detects the presence of impurities that can cause discoloration at elevated temperatures. Phthahc acid level is a monitor of how well moisture has been excluded during storage and shipment. 

Safety testing of a finished cosmetic product should be sufficient to ensure that the product does not cause irritation when used in accordance with directions, neither eUcits sensitization nor includes a sensitizer, and does not cause photoaHergic responses. Some of the methods for determining animal or human responses to cosmetics are noted in Table 3. 

Phosphates, which react with calcium to reduce the calcium ion activity, assist in stabilizing calcium-sensitive proteins, eg caseinate and soy proteinate, during processing. Phosphates also react with milk proteins. The extent of the reaction depends upon chain length. Casein precipitates upon addition of pyrophosphates, whereas whey proteins do not. Longer-chain polyphosphates cause the precipitation of both casein and whey proteins. These reactions are complex and not fully understood. Functions of phosphates in different types of dairy substitutes are summarized in Table 9 (see also Food additives). 

Stomach and intestinal ulcers. 8.3 Side effects Occasionally, headaches may be caused in people who are sensitive to bitter substances. 8 4 Dosage and manner of use Boiling water (ca. 150 ml) is poured over two tea-spoonfuls of the Lea, covered and allowed to draw for 5 10 min, and then passed through a tea strainer. If not otherwise pre.scribed, a cup of the fresh and 8.2 Dosage and manner of use Boiling water fca. 150 ml) is poured over a table-spoonful of the tea, covered and allowed to draw for ca. 10 min., and then passed through a tea strainer. 11 not otherwise prescribed, a cup of the freshly prepared tea is drunk warm several times a day between meals. 8.3 Note Store protected from light and moisture. 

The major effect of such open burning is the nuisance caused by the smoke, but health effects are noticed by sensitive individuals downwind from the bum. Table 30-18 lists the pollutant emissions from grass field burning (15). 

Another event which may occur is hydrolysis. This is a chemical reaction between the plastic and water. It occurs extremely slowly at room temperature but can be significant at moulding temperatures. Hydrolysis causes degradation, reduction in properties (such as impact strength) and it is irreversible. Table 4.3 indicates the sensitivity of plastics to moisture. Note that generally extrusion requires a lower moisture content than injection moulding to produce good quality products. 

The OP group of receptois share common effector mechanisms. All receptois couple via pertussis toxin-sensitive Go and Gi proteins leading to (i) inhibition of adenylate cyclase (ii) reduction of Ca2+ currents via diverse Ca2+ channels (hi) activation of inward rectifying K+ channels. In addition, the majority of these receptors cause the activation of phospholipase A2 (PLA2), phospholipase C 3 (PLC 3), phospholipase D2 and of MAP (mitogen-activated protein) kinase (Table 3). 

The problems caused by shales in petroleum activities are not new. At the beginning of the 1950s, many soil mechanics experts were interested in the swelling of clays. It is important to maintain wellbore stability dining drilling, especially in water-sensitive shale and clay formations. The rocks within these types of formations absorb the fluid used in drilling this absorption causes the rock to swell and may lead to a wellbore collapse. The swelling of clays and the problems that may arise from these phenomena are reviewed in the literature [528,529,1788,1900]. Various additives for clay stabilization are shown in Table 3-1. 

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