Effective concentration range

The synthesis of the photoaffinity probe, NAZA-FL, lc, will be described elsewhere. The effects of this acyclic modifier on mitochondrial activities were assayed as previously described (5,6). The results are summarized in the Table. The effects, and the effective concentration range, of compounds lc and La are similar in the dark. With the photolabile modifier,< T(c, illumination with strong light resulted in an irreversible preferential inhibition of the energy-dependent proton movements this effect was not relieved by phosphatidylcholine vesicles. Hence, the modifier became covalently bonded in the vicinity of its implantation. Additional experiments were performed with phosphate-washed (12) membrane preparations (ATPase-enriched inner membrane frac-... 

The numbers and concepts discussed in the preceding paragraph are shown graphically in Figure 10-5. Under routine cell culture conditions (e.g., with ca. 10 mammalian cells per milliliter of growth medium), there are about 10 molecules of ManNLev in the effective concentration range 10 to 20 mM (A). 

Preliminary results from our laboratory have also shown that piquerol A can induce a 100% of mortality of the yellow fever (Aedes aegypti) and common mosquito Culex quinquefasciatus) larvae. Effective concentration ranged from 400-500 PPM [120]. 

Approximately 50% of procainamide is metabolized in the liver. The major metabolite NAPA possesses activity, primarily class III antiarrhythmic properties. The fraction as NAPA averages 0.33 and 0.20 in fast and slow acetylators, respectively. It is unknown and impossible to predict the contribution of NAPA to arrhythmia suppression. The effective concentration range for procainamide and NAPA are 4 to 10 pg/ml and 7 to 15 pg/ml, respectively. ... 

Know the therapeutic range and/or the effective concentration range for the drug. 

An ethanol extract of Hemidesmus indicus was found to reduce the toxicity of gentamicin to hair cells in organotypic cultures without affecting the uptake of gentamicin. The effective concentrations ranged from 25 to 100 fig/ml (Previati et al. 2007). 

More commonly, demulsifiers are surface-active substances (surfactants) that have the ability to destabilize emulsions. This involves reducing the interfacial tension at the emulsion interface, often by neutralizing the effect of other surfactants that are stabilizing the emulsion. An example is antagonistic action - addition of an O/W promoter to break a W/O emulsion (see sensitization in Section 5.4). Mikula and Munoz [81] trace the historical evolution of demulsifier chemistry and the effective concentration range. Several reviews of demulsifier chemistry and properties are also available [73,75 - 79,82 - 87]. In order to perform, a demulsifier should have the following parameters ... 

Demulsifiers are frequently surfactants the relationship between demulsifier stmcture and performance has been studied for over 50 years [94]. Mikula and Munoz [88] trace the historical evolution of demulsifier chemistry and effective concentration range, and several reviews of demulsifier chemistry and properties are also available [95-99]. A demulsifier must displace or counteract the emulsifying agent stabilizing the emulsion, and promote aggregation and coalescence of the dispersed phase into large droplets that can be separated [92,93]. 

The role of surfactants in stabUizing emulsions, as well as the relationship between demulsifier structure and performance, has been identified for over 50 years [J9]. The classification of surfactants as well as demulsifiers is quite arbitrary, but a commonly used one is based on chemical structure [20, 21], Chemical types include nonionic, anionic, and cationic. A brief summary of the evolution in demulsifier chemistry over the years and the effective concentration range is presented in Table 1. The development of chemicals which are more surface active has allowed for reductions in the average dosages. 

Experiments from our laboratory indicate that MSA also stimulates AIB transport in primary cultures of normal rat hepatocytes (Sachs, Mishin, and Kilberg, unpublished results). The effective concentration range tested was 10" to 10 MMSA which is in good agreement with the results of Heaton et al. (47) for HTC hepatoma cells. Whether the stimulatory action in the hepatocytes is entirely mediated via the MSA receptor remains to be established, but that conclusion seems likely based on the binding studies of Massague and Czech (46) described above. 

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