Dextran is a bacterial polysaccharide which can be produced from sucrose and usually used for clinical treatment as one kind of practical polysaceharide drags. The molecular weight distribution of dextran is an important index for its application. However, it is hardly to control strictly by the traditional separating method with ethanol. Taking separation and purification of medicinal dextran as the object of this study, a new separation technology, coupling electro-ultra-filtration with solvadng-out-crystagization (EUF-SOC) was developed and applied successfully, It was found that the permeate flux of optimized EUF-SOC technology is several times of normal ultra-filtration (UF) or enhanced ultrafiltration with an electric field (EUF), and its quality is higher than that of traditional process. The selective crystallization of dextran can be realized and homogeneous dextran crystals can be got in the process of membrane filtration by using EUF-SOC technology. The results showed that the mass transfer coefficient (k) of EUF-SOC process is about 4 times of UF and 2 times of EUF.

Spirulina platensis was batch cultivated in a novel 3.5 l magnetic air-lift photobioreactor with external-loop on which 0–0.55 T electromagnetic field (EMF) was imposed to investigate the EMF effects on the algal growth and nutrition composition. At the same time, the correlative mechanism was discussed mainly based on C, N, P uptake. It was found that, EMF has double-side effects on S. Platens is cultivation depend on EMF intensity. 0.25 T EMF stress was found to be suitable for the algal cultivation enhancement increasing the maximum cell dry weight by 22% in a time period two days less than that of the control at 35 C and 2521mol photons m2 S1. In addition, the nutritional composition of S. platens is was improved in both essential amino acids such as histidine and trace elements Ni, Sr, Cu, Mg, Fe, Mn, Ca, Co and V. It was suggested it was possible to optimize the cultivation process of S. platens is by imposing suitable weak EMF which may enhance the nutrition assimilation e.g. C, N, P and minerals by S. platens is.

The influence of nine small organic molecules on the phosphorescence properties of cyclodextrin (CD)/1-naphthol/1,2- dibromoethane (DBE) and CD/2-naphthol/DBE ternary inclusion complexes are examined by means of room temperature phosphorescence (RTP) measurements. It was demonstrated that the rigidity of -CD/naphthol inclusion complex, RTP intensity and lifetime could be enhanced when different small organic molecules (less than 1% v/v) were added respectively; the analytical characters of two kinds of naphthols in host–guest stabilized-RTP were improved. The linear range of 1-naphthol become broad in the presence of n-propanol, methanol, ethanol or 2-propanol and its detection limitwas reduced from 4×10−6 to 7.5×10−8 mol l−1 in the presence of 0.6% (v/v) methanol. Likewise, for 2-naphthol, the detection limit was reduced from 2.0 × 10−6 to 2.8×10−7 mol l−1 and to 8.1 × 10−7 mol l−1 after 0.5% (v/v) glycol and 0.2% (v/v) 2-propanol being added, respectively.

The bioeffects of selenium on the growth of Spirulina platensis and the selenium distribution were investigated. S. platensis was batch cultured in Zarrouk medium containing increasing concentrations of sodium selenite. The biotransformation characteristic of selenium was analysed by the determination of the detailed selenium distribution forms. At 35 C, 315.2 lEm2 s1, sodium selenite concentrations below 400 mg l1 were found to stimulate algal growth, especially in the range of 0.5–40 mg l1. However, above 500 mg l1 sodium selenite was toxic to this alga with the toxicity being related to the sulfite level in the medium. S. platensis was found to resist higher selenite by reducing toxic Se(IV) to nonsoluble Se(0). Selenium was accumulated efficiently in S. platensis during cultivation with accumulated selenium increasing with selenite concentration in the medium. It was demonstrated that inorganic selenite could be transformed into organic forms through binding with protein, lipids and polysaccharides and other cell components. The organic selenium accounted for 85.1% of the total accumulated selenium and was comprised of 25.2% water-soluble protein-bound, 10.6% lipids-bound and 2.1% polysaccharides-bound selenium. Among the organic fractions lipid possessed the strongest ability to accumulate Se (6.47 mg kg1). The 14.9% inorganic selenium in S. platensis was composed of Se(IV) (13.7%) and Se(VI) (1.2%).

Colon-targeting drug delivery systems (CDDSs) are employed to improve the bioavailability of protein and peptide drugs through the oral route. So it is important to prepare the drug carriers for oral CDDS. In this study, the Enzyme-Resistant starch (RS) was studied for use as a vehicle in oral colon-targeting drug delivery. The characteristics of RS powders were investigated by X-ray diffraction, polarizing microscopy, DSC and SEM, and their film were examined by enzymatic digestion test. The results showed that RS could be a promising film-former for pharmaceutical coatings, having good stability to enzymatic digestion. Furthermore, a novel peroral formulation using RS coating and bovine serum albumin as a model drug was studied for colon-specific drug delivery in vitro. Drug release studies have shown that RS coating could delivery the drug to the colon and the release rate in simulated colonic fluids was dependent on the biodegradation of RS and its coatings. It is indicated that the RS coated tablet is a potential system for oral CDDS.