Advanced Materials Research Vols. 236-238

Abstract: The interaction between human serum albumin (HSA) and salvianolic acid A (SA-A) was investigated by means of spectroscopy. The thermodynamic parameters ΔH and ΔS, had been calculated to be 148.94KJ·mol^-1 > 0, and 640.85 J·mol^-1·K^-1 > 0, respectively. The distance between the donor (HSA) and receptor (SA-A), r, was obtained to be 2.49nm according to Förster's non-radiative energy transfer theory. The experimental results revealed that SA-A could quench the fluorescence of HSA by a static quenching mechanism. Furthermore, the binding constants between HSA and SA-A were obviously affected by metal ions, decreased in the presence of Co(Ⅱ) and Mg(Ⅱ), increased with Ni(Ⅱ) and Zn(Ⅱ), and no change with Cu(Ⅱ). The interaction between SA-A and HSA was driven mainly by hydrophobic force.

Abstract: The batch extraction kinetics equation based on Fick’s law was obtained by a direct dimensionless modification with the extraction capacity factor (f₁). f₁ integrates the penetrating and dissolving capacity of the extraction solvent and its effect on the plant tissue. The effect of ethanol content (45%–75%, V/V) on the batch extraction of curcumin from turmeric (Curcurna longa L.) was evaluated for 3.69 mm turmeric particles at 65 °C, 80:1 liquid/material ratio, without stirring. Based on the results, and considering ethanol’s dielectric constant, surface tension, viscosity and effects on the turmeric tissue, the batch extraction kinetics equation was established using the variable separation method. The model calculations matched well with the experimental data obtained. In addition, the mechanism of ethanol’s effect on the extraction of curcumin from turmeric was also investigated.

Abstract: Phenol and chlorophenols (CPs) are main toxic organic pollutants detected generally in source water. In the present studies, removal efficiency of phenol and CPs by using PAC adsorption was investigated, base on the control of drinking water sudden pollution. The results showed that the removal of phenol and CPs was essentially complete within 2 hours, and that the adsorption ratio in proper order was: 2, 4, 6- TCP > 2, 4- DCP > 2- MCP > PCP > phenol. The adsorption isotherm of phenol and CPs by PAC was consistent with the Freundlich and Langmuir adsorption mode. The study on the raw water collected from a lake in a university also provided the evidence that water quality affected the adsorption rate and adsorption capacity apparently. The phenol and CPs in sudden water pollution accidents was removed by addition of 20mgL^-1 PAC. Results provided technical solution for water pollution accidents to cope with phenol and CPs sudden.

Abstract: Separation of carotenoids has been carried out on the calyx of Physalis alkekengi var. francheti by means of supercritical CO₂. The influences of various parameters such as extraction pressure, temperature, processing time and particle size on the total carotenoid yield extracted are investigated in detail. A diffusion layer theory model is used to correlate the extraction yield vs. time profiles and it performs rather satisfactorily to describe the extraction process with an average absolute relative deviation varying from 3.2 to 11.0%.

Abstract: As a new environment-friendly waterproof material, polymer cement waterproof coating combines the rigidity of cement and the flexibility of polymer materials. The ratio of the L/P、the ratio of the C/P, the dosage of dispersant were discussed to investigate their effect on the coatings’ flexibility at low-temperature and the bond strength of wet surface.

Abstract: Solid dispersions (SD) were prepared with naringenin and polyvinyl pyrrolidone k-30 (PVP k-30) by the solvent evaporation method with three drying methods (microwave-vacuum drying, MVD; and spray drying, SPD; vacuum drying, VD). The physical state was characterized by DSC, PXRD, SEM, and FT-IR. The results showed that the vitro dissolution rate and extent of naringenin was improved significantly by SD as compared with the pure drug and physical mixtures (PM). The results of FT-IR showed that naringenin is possibly interacted with PVP k-30 via intermolecular hydrogen bond, the results of DSC and PXRD showed that all of the SD prepared with three drying methods was completely amorphous. Compared with other drying methods, the MVD method can save time and energy. The physical state of SD prepared with the three drying methods that stored in the 40 °C/75% RH chamber was stable in three month. These results suggest that MVD is feasible to replace the traditional time-consuming and low efficiency drying procedure for preparation of SD.

Abstract: Three types of single closed cell model, single-centered cubic, face-centered cubic and body-centered cubic were set up based on the geometric character of corn starch extrudate. The elastic moduli were simulated with finite elements method (FEM). Fitting equation for elasticity modulus and relative density calculated from each type of cell model was developed and validated with that calculated from Ashby-Gibson equation. The accuracy of results from finite elements analysis was comparable to that of Ashby-Gibson equation.

Abstract: This paper explains and demonstrates how to evaluate the sensitivity and specificity of wondfo chlamydia trachomatis rapid diagnostic cassette with GICA for detection of chlamydia trachomatis. 1026 genital specimens were collected from 630 females and 396 males.Two cassettes of wondfo and ClearView were used for the detection of Chlamydia trachomatis samples with blind detection simultaneously, inconsistent results by DFA. Sensitivity, specificity, positive predictive value and negative predictive value of wondfo cassette were analyzed. Out of 1026 samples detected, 83 were positive by both of wondfo and ClearView and 13 showed different results by wondfo and ClearView. Out of the 13 samples, the DFA confirmed 9 were positive. Therefore, 92 samples were truly positive and 934 were truly negative. The sensitivity, specificity, positive predictive value and negative predictive value of wondfo were 96.74% ,99.6% , 95.7% , 99.68%, respectively. The consistent rates of test results of the chlamydia trachomatis rapid diagnostic cassette , wondfo and ClearView, both were the same 98.64%. Of the three standard strains and two clinical strains of dilution test results showed that the sensitivity of wondfo slightly ClearView.The sensitivity and specificity of wondfo for the detection of Chlamydia trachomatis have the accept tability for clinical diagnostic and surveillance data.

Abstract: This work focused on optimization of ethanol fermentation of yeast cells immobilized by calcium alginate-chitosan (ACA) using orthogonal experiments. Alcoholicity of original cider was used as an evaluating indicator. The single factor tests indicated that fermentation factors, starting sugar content, inoculating quantity of yeast, initial pH and fermentation temperature, had different effect on ethanol yield. L₉(3⁴) orthogonal tests showed that the optimal conditions of cider fermentation were as followed: inoculating quantity (percentage of amount of ACA-yeast biocatalyst to volume of apple juice, g/mL) 4%, starting sugar content 20 °Bx, fermentation temperature 26 °C, initial pH 2.5. The verification experiments suggested the alcoholicity of original cider reached 10.9% under the optimal conditions.

Abstract: After the SOD was treated with different strength of electric field, the interactional mechanism of electric field on SOD activity was studied by circular dichroism. The activity of SOD was enhanced under the treatment by different strength of electric field. Circular dichroism spectra showed that the secondary structure of SOD was greatly changed by electric field, as β-sheet and β-turn contents decreased, while α-helix and random coil contents increased. It was considered that the increase of the α-helix structure near the active center would lead to the inactivation of SOD. The result of this study has important meaning to explain the biological effect of electric treatment seeds.