PH influences

Long before the concept of pH, influences of minerals in water were empirically demonstrated in the various methods of production of both malt and beer. Water with a large carbonate content, as found in Munich and Copenhagen, demands long-grown and highly dried malt together with slow... 

Kingsley, D. H. and Chen, H. (2008). Aqueous matrix compositions and pH influence feline calicivirus inactivation by high pressure processing. /. Food Prot. 71,1598-1603. 

As described in Chapter 1, the test battery approach is a pretest to establish an optimal AR protocol, based on the fact that two major factors (heat and pH) influence the achievement of a satisfactory result of AR-immunohistochemistry (IHC). As indicated in Table 1.1, a total of nine slides are required to test three conditions of heating temperature, and three different pH values of the AR solutions. Practically, it may be performed in simpler ways as shown in Table 1.2. The following suggested protocol is based on our experience. 

H. Bruning, Photocatalyzed oxidation of alcohols and organochlorides in the presence of native Ti02 and metallized Ti02 suspensions. Part (I) Photocatalytic activity and pH influence, Water Res. 33 (1999) 661-668. 

Secondly, the pH can have an effect on the selectivity. In pharmaceutical analysis, mainly compounds with either basic or acidic properties have to be analyzed. Since the pH influences the dissociation and charge of these substances, it will affect their retention behavior. Changing the organic modifier does not lead to major selectivity differences, but it can enhance the differences induced by pH and/or stationary phase changes. Also, the column... 

Geisler A, Klysner R, Andersen PH Influence of lithium in vitro and in vivo on the catecholamine-sensitive cerebral adenylate cyclase systems. Acta Pharmacologica et Toxicologica 56 80-97, 1985... 

The solution pH influences a number of factors, and it is not always simple to predict its effect. Thus, thiourea decomposition (in alkaline solution) is generally faster at higher pH. The probability of the presence of a solid phase of Cd(OH)2 and its concentration in the solution are both increased at higher pH (higher OH concentration). The pH is determined, in the example given earlier, by the concentration of ammonia. However, it can be adjusted independent of the ammonia concentration. Addition of an ammonium salt, which with ammonia, acts as a buffer, will lower the pH through the following equilibrium ... 

Temperature and pH influence the rate at which the M-L fermentation proceeds. By determining cell numbers in the new wine at weekly intervals (60, 64), the generation time (g) of the lactic culture during the M-L fermentation was calculated. Extreme growth rates in terms of generation time (g) together with the related pH and temperature data are shown in Table X. Generation time varied widely with different combinations of temperature and pH. 

CdS fluorescence was also observed in cationic DODAC and 1 vesicles, albeit with much less intensity than that found in DHP vesicles. The preparation pH influenced the CdS fluorescence in all vesicles. Interestingly, CdS fluorescence was somewhat stronger in unpolymerized than polymerized vesicles prepared from 1. This was not a consequence of the uv irradiation applied to polymerize tfie vesicles, since such irradiation had no effect on CdS fluorescence in nonpolymerizable surfactant vesicles (such as DHP or DODAC). However, this effect correlated with the ability of EDTA to act as a sacrificial electron donor in hydrogen production experiments (vide infra). 

Two parameters of excipients that are important to the compatibility formulator are (i) the ability of the excipients to absorb water at variable humidity and (ii) the pH that the excipient will impart in the solid-state environment. Knowledge of water sorption of excipients is well documented (27) and is used to estimate the amount of water the excipients will introduce into a solid-formulation mixture (30). The percentage of water and the dispensation of water, whether bound or variably adsorbed, was shown to have a dramatic effect on the hydrolytic stability of aspirin (31). It is well known that water will redistribute within solid pharmaceutical systems and this redistribution has been modeled and studied extensively (18). The pH influence that an excipient imparts to the formulation matrix can be directly related to... 

The pH of the gastrointestinal tract varies, being 1-2 in the stomach, 5-6 in the duodenum, 6-7 in the jejunum, 7-8 in the ileum, and 8-9 in the large intestine. This variation in pH influences the extent to which acidic or basic chemical substances are ionized, which influences the extent of their absorption. The degree of ionization of an acidic substance or a basic substance at a given pH can be expressed by the Henderson-Hasselbalch equations (equations (2) and (3), respectively) ... 

The production of B. bassiana Prl and Pr2 proteases were examined in media both under buffered and unbuffered conditions (Dias et al. 2008). In unbuffered medium supplemented with cuticle, Prl and Pr2 activities were detected mainly at a pH of 5.5 or higher. In buffered cultures, both protease types were produced - albeit at lower levels - by carbon and nitrogen derepression alone, indicating a substantial basal level of Prl and Pr2. At alkaline pH in the presence of cuticle, the production of these proteases seemed to be induced, suggesting that the culture pH influences their expression. 

The pH influences the ratio of protonated to non-protonated TTA, which has impact on pharmacological behaviour (see Sect. 2.2) as well as on sample preparation procedures (see Sect. 3.1). Especially, when extracting by liquid-liquid extraction (LLE), the partition between an aqueous and an organic non-polar phase is... 

Absorbance effect on kinetics SBBT, C0 = 1-5 mM, toxicity test. Intermediates SBPR, I0, pH influence, C=3xl04 M,... 

Atrazine O3, O3/H2O2, O3/UV CBPR, pH influence, mechanism, CATZ = 6.95x10 5 M, four LVP lamps of 15 W 163... 

In the first place, we have not considered the pH influence on the dissociation of weak solute ions or pairing ions. The effect of the pH in IPC will be addressed below. 

Fleckenstein B, Molberg O, Qiao SW, Schmid DG, von der Mulbe F, Elgstoen K, et al. Gliadin T cell epitope selection by tissue transglutaminase in celiac disease. Role of enzyme specificity and pH influence on the transamidation versus deamidation process. J Biol Chem 2002 277 34109-34116. 

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