Vesicular Nanostructure Formation by Self-Assembly of Anisotropic Penta-phenol-Substituted Fullerene in Water

A study on self-assembly of anisotropically substituted penta-aryl fullerenes in water has been reported. The penta-phenol-substituted amphiphilic fullerene derivative C60Ph5(OH)(5)],exhibited self-assembled vesicular nanostructures in water under the experimental conditions. The size of the vesicles Was observed to depend upon the kinetics of self-assembly and could be varied from similar to 300 to similar to 70 nm. Our mechanistic study indicated that the self-assembly of C60Ph5(OH)(5) is driven by extensive intermolecular as well as water-mediated hydrogen :bonding along with fullerene-fullerene hydrophobic interaction in water. The cumulative effect of these interactions is responsible for the stability of vesicular structures even on the removal of solvent. The substitution of phenol with anisole resulted in different packing and interaction of the fullerene derivative, as Indicated in the molecular dynamics studies, thus resulting in different self-assembled nanostructures. The hollow vesicles were further encapsulated with a hydrophobic conjugated polymer and water-soluble dye as guest molecules. Such confinement of pi-conjugated polymers in fullerene has significance in bulk heterojunction devices for efficient exciton diffusion.

I. Studies on the activation of Drosophila phenol oxidase. II. Studies on serum insulin in normal subjects and diabetics

Part I

Phenol oxidase is the enzyme responsible for hardening and pigmentation of the insect cuticle. In Drosophila, phenol oxidase is a latent enzyme. Enzyme activity is produced by the interaction of a number of protein components. A minimal activation scheme consisting of six protein components, designated Pre S, S activator, S, P. P' and Ʌ₁ is described. Quantitative assays have been developed for the S activator, S, P and P' proteins and these components have been partially purified. Experiments describing the interactions of the six components have been conducted and a model for the activation of phenol oxidase in a minimal system is proposed. Possible mechanisms of the reactions between the constituents of the activating system and potential regulatory mechanisms involved in phenol oxidase production and function are discussed.

Part II

A method has been developed for the partial purification of insulin from human serum. A procedure for the determination of the electrophoretic mobility of serum insulin on polyacrylamide gels is described. An electrophoretic analysis of insulin isolated from a normal subject is reported and in addition to a major band, the existence of a number of minor bands of immunoreactive insulin is described. A comparison of the electrophoretic patterns of insulin isolated from normal and diabetic subjects was carried out and indications that differences between them may occur are reported.

Proposed Environmental Quality Standards for Phenol in Water

This is the Proposed Environmental Quality Standards (EQS) for Phenol in Water prepared for the National Rivers Authority, and published by the Environment Agency in 1995. The report reviews the properties and uses of phenol, its fate, behaviour and reported concentrations in the environment and critically assesses the available data on its toxicity and bioaccumulation. The information is used to derive EQSs for the protection of fresh and saltwater life and for the abstraction of water to potable supply. Phenol is widely used as a chemical intermediate and the main sources for phenol in the environment are of anthropogenic origin. Phenol may also be formed during natural decomposition of organic material. The persistence of phenol in the aquatic environment is low with biodegradation being the main degradation process (half-lives of hours to days). Phenol is moderately toxic to aquatic organisms and its potential to bioaccumulate in aquatic organisms is low.

Kinetic modeling of growth and biodegradation of phenol and m-cresol using Alcaligenes faecalis

A phenol-degrading. microorganism, Alcaligenes faecalis, was used to study the substrate interactions during cell growth on phenol and m-cresol dual substrates. Both phenol and m-cresol could be utilized by the bacteria as,the sole carbon and energy sources. When cells grew on the mixture of phenol and m-cresol, strong substrate interactions were observed. m-Cresol inhibited the degradation of phenol, on the other hand, phenol also inhibited the utilization of m-cresol, the overall cell growth rate was the co-action of phenol and m-cresol. In addition, the cell growth and substrate degradation kinetics of phenol, m-cresol as single and mixed substrates for A. faecalis in batch cultures were also investigated over a wide range of initial phenol concentrations (10-1400 mg L-1) and initial m-cresol concentrations (5-200 mg L-1). The single-substrate kinetics was described well using the Haldane-type kinetic models, with model constants of it mu(m1) = 0.15 h(-1), K-S1 = 2.22 mg L-1 and K-i1 = 245.37 mg L-1 for cell growth on phenol and mu(m2) = 0.0782 h(-1), K-S2 = 1.30 mg L-1 and K-i2 = 71.77 mgL(-1), K-i2' = 5480 (mg L-1)(2) for cell growth on m-cresol. Proposed cell growth kinetic model was used to characterize the substrates interactions in the dual substrates system, the obtained parameters representing interactions between phenol and m-cresol were, K = 1.8 x 10(-6), M = 5.5 x 10(-5), Q = 6.7 x 10(-4). The results received in the experiments demonstrated that these models adequately described the dynamic behaviors of phenol and m-cresol as single and mixed substrates by the strain of A. faecalis.

Hydrogenation of phenol in scCO(2) over carbon nanofiber supported Rh catalyst

A catalyst of Rh nanoparticles supported on a carbon nanofiber, 5 wt.% Rh/CNF, with an average size of 2-3 nm has been prepared by a method of incipient wetness impregnation. The catalyst presented a high activity in the ring hydrogenation of phenol in a medium of supercritical CO2 (scCO(2)) at a low temperature of 323 K. The presence of compressed CO2 retards hydrogenation of cyclohexanone to cyclohexanol under the reaction conditions used, and this is beneficial for the formation of cyclohexanone, increasing the selectivity to cyclohexanone.