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The Extra-Normal Voice

This chapter presents an overview of new developments in vocal exploration. Beginning with a discussion of multiple parameters involved in voice production, this chapter identifies the crucial role that non-linear phenomena has in the performance of the extra-normal voice. In this article, two related taxonomies are presented (source production related to degree of voicing; emphases within the aco

Facile synthesis of fatty acid esters in high yields

The facile synthesis of esters by lipase-catalysed esterification of fatty acids and ethanol is demonstrated. Evaporation of the water generated in the reaction allowed the rapid production of esters of >99% yield in refluxing pentane or hexane. Water was trapped by condensing the refluxing vapor phase and passing it over activated molecular sieves in a reflux trap. High yields were rapidly obtain

Organic solvent changes the chymotrypsin specificity with respect to nucleophiles

In α-chymotrypsin-catalyzed acyl-transfer reactions in water the specificity of the enzyme (the nucleophile reactivity of amino acid amides) is correlated with the substrate hydrophobicity and increases as the hydrophobicity of the side chain of the amino acid amides is increased. In a low water system (4% H2O) bulky amino acid amides are less efficient nucleophiles. The specificity of α-chymotryp

Nucleophile specificity in α-chymotrypsin- and subtilisin-(Bacillus subtilis strain 72) catalyzed reactions

Nucleophilic properties of amino-acids were studied systematically in acyl-transfer reactions catalyzed by α-chymotrypsin and subtilisin from Bacillus subtilis strain 72 (subtilisin 72) using Mal-l-Ala-l-Ala-l-PheOMe as the acyl-group donor. In α-chymotrypsin-catalyzed reactions, the nucleophile reactivities increase in the following order: d-AlaNH2 < GlyNH2 < l-AlaNH2 < l-ScrNH2 < l-ThrNH2 < l-Hi

Modification of the microenvironment of enzymes in organic solvents. Substitution of water by polar solvents

Enzyme catalysis in water-immiscible organic solvents is strongly influenced by the amount of water present in the reaction mixture. Effects of substitution of part of the water by other polar solvents were studied. In an alcoholysis reaction catalyzed by chymotrypsin deposited on celite, it was possible to exchange half of the water by formamide, ethylene glycol or dimethyl sulfoxide with often i

Complex formation between chymotrypsin and ethyl cellulose as a means to solubilize the enzyme in active form in toluene

Chymotryspin and ethyl cellulose were mixed in an aqueous phosphate buffer solution and freeze dried. Due to complex formation between the substances it was possible to dissolve or at least finely disperse these preparations in toluene. The chymotrypsin-ethyl cellulose complexes were characterized by light scattering measurements. Complexes were also formed by mixing enzyme powder in toluene conta