Resonance Rayleigh scattering study of interaction of hyaluronic acid with ethyl violet dye and its analytical application.

In near weak acid to neutral medium, ethyl violet (EV) can react rapidly with hyaluronic acid (HA) to form a complex, which results in a significant enhancement of resonance Rayleigh scattering (RRS) and an appearance of a new spectrum, and the scattering wavelengths appear at 231, 274, 326, 498 and 640 nm. The maximum scattering wavelength appears at 326 nm. The RRS intensity is directly proportional to the concentration of HA in the range of 0.

Resonance Rayleigh scattering study of interaction of heparin with some cationic surfactants and their analytical application.

Binding of heparin with a cationic surfactant such as cetyldimethyl benzylammonium chloride (CDBAC), tetradecyldimethyl benzylammonium chloride (Zeph), cetylpyridinium bromide (CPB), tetradecane pyridinium bromide (TPB) and cetyltrimethylammonium bromide (CTAB) in a near-neutral medium can result in a significant enhancement of resonance Rayleigh scattering (RRS) intensities. The results showed that the reaction conditions and RRS spectral characteristics of these reactions are similar, but their sensitivities are obviously different. Among them, the sensitivity of CDBAC with an aryl and large molecular weight is the highest, while that of CTAB without aryl and with small molecular weight is the lowest.

[Studies on the ploymorphic of sperm of F2 hybrids of red crucian carp x common carp].

AThe ultrastructures of the sperm of F2 hybrids of red crucian carp x common carp were studied by using scanning and transmission electron microscope. The sperm of the F2 hybrids consisted of head, mid-piece and tail. There was no acrosome at the anterior end of the nuclears, whereas there was a vesicle.

[Studies on chemical constituents in leafs of Ilex kudingcha].

Objective: To study chemical constituents of Ilex kudingcha.

Method: The constituents were isolated by chromatographic method and the structures were identified on the basis of spectral analysis.

Result: Seven compounds, lupeol(I); 3 beta-hydroxyl-lup-20(29)-ene-24-methyl ester(II); lup-20(29)-ene-3 beta-, 24-diol(III); beta-sitosterol(IV); ursolic acid(V); daucosterol (VI); mannitol were obtained(VII).

Water pricing towards sustainability of water resources: a case study in Beijing.

The role of water pricing for managing water resources is widely recognized in many areas of the world because of the increasing scarcity of water resources, a high competition between water uses and environmental degradation. Based on the analysis of cost of water, this paper explores which types of cost should be reflected in the water pricing enhancing the sustainability of water resources. The principle of full cost pricing in which the cost should include supply cost, opportunity cost and externalities is proposed as a means to achieve the sustainability of water resources.

Overexpression of cyclin D2 is associated with increased in vivo invasiveness of human squamous carcinoma cells.

Overexpression of cyclin D2 was studied in 10 human squamous cell carcinoma lines, to establish whether this gene plays a role in tumor progression. We found that those cell lines that overexpressed cyclin D2 (CCND2) had the most invasive in vivo behavior. The invasive ability of the cell lines was determined by evaluating the penetration of carcinoma cells into the tracheal wall in an in vivo assay with de-epithelialized tracheas transplanted into the subcutaneous tissue of nude mice.