The Photochemical Study of HSA and BSA with Resonance Light Scattering and Fluorescence Spectra

The resonance light-scattering (RLS) of human serum albumin (HSA) and bovine serum albumin (BSA) is reported for the first time, and applied to study photochemical reaction of HSA and BSA. The fact of photocrosslinking self-association effect in HSA and BSA solutions is identified by the enhancement of RLS. The fluorescence quenching at about 350 nm and 700 nm proves that tryptophan (Trp) residues are one of the photochemical activity sites in HSA and BSA molecules. The Rayleigh scattering (RS) spectra of HSA and BSA that were neglected in fluorescence spectra before are found at about 296 nm, 592 nm and 888 nm for the first time, and are of adventageous to studying the aggregation of HSA or BSA. The possible photochemical reaction mechanism is also proposed.

A Model for Liquid-Diffusion Catalytically Grown Fibrous Carbon Material

A mechanism for the catalytically growth of vapor grown fibrous carbon (VGFC) preparing from the floating catalyst method has been proposed, in which liquid diffusion-determined diffusion of carbon atoms through catalyst particles is described mathematically, and the physical and chemical properties of the catalyst particles during the growth process are taken into account. From the model the growth rate and grown length of VGFC are calculated theoretically which coincides with the experimental data; and the necessity of reducing gas such as hydrogen in preparing VGFC is explained as to reduce Fe3C, which acts as intermediate catalyst shown by the model. Fe3C formed on the surface of gamma-Fe will stop the growth of carbon fiber if they can not be reduced at once. Additionally, the growth temperature and diameter of VGFC are also discussed in the paper.

The Effect of the Chain Length on MMA Free Radicl Polymerization

In the polymerization process of methyl methacrylate (MMA), the Arrhenius parameters (activation energy and frequency factor) of propagating reaction monotonically decrease with increasing monomer conversion. At the beginning and middle stage of the propagating reaction, the increase of radical chain length is the main reason of above mentioned change. And at the end stage, the sharp decrease of k(p) indicates that the activation energy is approximately incline to zero and the propagating reaction is controlled by molecular diffusion motion.

Formation and aggregation number of sodium dodecyl sulphonate-polyvinylpyrrolidone aggregates

THE interaction of surfactants with water-soluble polymers has been an active subject for manyyears. Early investigations were mainly concerned with the effect of synthetic detergents onnatural proteins, such as gel. These studies were motivated by observations of biologicalphenomena involving surfactants and proteins such as the inactivation of bacterial

Evaluation of diameter dis-tribution of inside cavities of open CNTs by analyses of nitrogen cryo-adsorption isotherm

Precise evaluation of innerdiameter distribution of open carbon nanotubes (CNTs) is the basis of systematic investigation of physico-chemical processes occurring in nano-sized quasi-1-dimensional carbons. Due to the porosity characteristics and adsorption properties, this study evaluated the innerdiameter and its distribution of carbon nanotubes by analyses of nitrogen cryo-adsorption isotherms, and proved that the gas adsorption method is an effective method to characterize the inner cavity structure in comparison with that of electron microscopy observations and Raman measurements. The advantages of this method are as follows: Firstly, statistical information for innerdiameter distribution of open nanotubes can be obtained; Secondly, the method based on the adsorption process in inner cavities is of importance for investigation of other physico-chemical pro- cesses inside the cavities of carbon nanotubes. And finally, if combining with other characterization methods, complete structural information