A Taguchi robust design method with an L₉ orthogonal array was implemented to optimize experimental conditions for the biosynthesis of triethanolamine (TEA)-based esterquat cationic surfactants using an enzymatic reaction method. The esterification reaction conversion% was considered as the response. Enzyme amount, reaction time, reaction temperature and molar ratio of substrates, [oleic acid: ...

A purification procedure to prepare highly purified DNA-dependent RNA polymerase from Bacillus subtilis vegetative cells is described. The enzyme consists of four different subunits, /?’, /?, (T and 01 (molecular weights 154000 for B’ and /?, 56000 for (T and 43000 for 01) in a molar ratio 1 : 1 : I : 2. By phosphocellulose chromatography RNA polymerase has been disscociated in (T subunit and c...

The antibacterial properties of bismuth are greatly enhanced when bismuth is combined with certain lipophilic thiol compounds. Antibacterial activity was enhanced from 25- to 300-fold by the following seven different thiols, in order of decreasing synergy: 1,3-propanedithiol, dimercaprol (BAL), dithiothreitol, 3-mercapto-2-butanol, beta-mercaptoethanol, 1-monothioglycerol, and mercaptoethylamin...

We describe a new route, in which the polyethylene glycol (PEG) is used both as a solvent and reducing reagent and the polymer polyvinglpyrrolidone (PVP) is used as capping agent, for the synthesis of monodisperse silver nanoparticles. Uniform nanospheres with an average diameter of 54 nm can be routinely synthesized in high yield through this approach by using a PVP/AgNO3 molar ratio of 8 at 2...

Oxygen evolution (OE) by photosystem II (PSII) is dependent on the lipid/PSII molar ratio of the PSII membrane. To explain the data, a lipid-mediated ‘cooperative function of PSII units’ (CF model) was postulated (Fragata, Strzalka, Nénonéné, 1991). According to the CF model, the OE enhancement has its origin in the formation of PSII aggregates at the optimum lipid/PSII molar ratio, or near. Th...

The reaction of 6-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione (1) as a binucleophile with primary aromatic or heterocyclic amines and formaldehyde or aromatic (heterocyclic) aldehydes in a molar ratio (1:1:2) gave the pyrimido[4,5-d]pyrimidin-2,4-dione ring systems 2-5. Treatment of 1 with diamines and formalin in molar ratio (2:1:4) gave the bis-pyrimido[4,5-d]pyrimidin-2,4-diones 6-8. Furth...

The Cyclic Voltammetric behaviour of copper(II)tetramethylethylenediamine systems with [Cu(II)]:[tmen]=1:10, 1:100 molar ratios, 1×10M Cu(ClO4)2.6H2O in aqueous 0.2M NaClO4 supporting electrolyte have been studied at pH5.0,6.50 7.20,9.10, 10.30, 10.85 and 11.20. The electrode process show quasi reversible one electron charge transfer preceded and followed by chemical reaction at glassy carbon e...