Applied Mechanics and Materials Vols. 138-139

Abstract: The aim of this study was to determine whether the Escherichia coli (EPEC) attached to cells by the TLR4. A fusion between gene encoding fluoresce-enhanced green fluorescent protein (EGFP) and Toll like receptor 4 (TLR4) was constructed and expressed in Escherichia coli. Then the pEGFP-N1-TLR4 fusion expression vector was transfected into HT-29 cells. The green fluoresce was observed at the plasma membrane of HT-29 cells under inverted fluorescent microscopes. In addition, the FITC stained EPEC was also observed adherence to the TLR4 of HT-29 cells.The results indicated that the EPEC adhered to cells by bonding to TLR4 protein. It is the first time that the TLR4 has been explained as an adhesion receptor.

Abstract: The Anti-inflammatory activity of pentacyclic triterpenes, oleananes (1,2), urasanes (3-11), lupanes (12,13), taraxasteranes (14,15), which isolated from Nerium oleander L, were examined. Ursolic acid (5) showed significant activity and compounds (1, 12) and (14) showed weak to modelate activity toward inhibitory activity on ICAM-1 expression.

Abstract: Mitochondrial dysfunction and oxidative stress are among the earliest events linked to Alzheimer Disease and might play a causative role in disease onset and progression. In this paper, a biomedical imaging and visualization model was set to investigate the mitochondrial dysfunction and oxidative stress in Aβ/Cu²⁺-treated cells, which contribute in a significant manner to bioenergetic failure and mitochondrial dysfunction, by measuring mitochondrial membrane potential, Ca²⁺, chromatin condensation and ROS. This evaluating method opens a window for analyzing the protective effect of a certain substance in improving mitochondrial function and preventing oxidative stress in AD development.

Abstract: The production of xylanase (TrxA) by Trichoderma reesei JL-1 in solid-state fermentation (SSF) was optimized by response surface methodology (RSM). Results revealed that factors of concentration of added ammonium sulfate, and moisture content had significant effect on the TrxA production (P<0.05). The maximum xylanase activity (485.0 U/g U/g dry fermentation product) was obtained at 2.9% the ammonium sulfate by employing wheat bran as the solid substrate, 61.6% moisture content and 59.5-h fermentation, which was close to the predicted one, and was 1.8 times as high as that of the basic medium. The optimum temperature and pH for TrXA activity were 45°C and pH 5.0, respectively. Over 90% of xylanase activity was retained after treatment of the enzyme by preincubation over a pH range of 3.0-5.0 for 1 h at 25°C. TrxA exhibited K_m and V_max values of 1.458mg/mL and 25.316 μmol/min/ml, respectively. In the presences of metal ions such as Mn²⁺the activity of the enzyme increased. Whereas strong inhibition of the enzyme activity was observed in the presences of Fe³⁺ and Ca²⁺.

Abstract: The total flavones in the root of Zanthoxylum nitidum (Roxb.) DC was extracted with 70% ethanol and the content of the total flavones in it was determined to be 82.9 mg/g by spectrophotometry at wavelength 510 nm based on rutin as standard. The in vitro antimicrobial activities of the total flavones extract against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella sp, Aspergillus niger, Aspergillus flavus, Penicillium citrinum, Saccharomyces cerevisiae, Rhodotorula glutinis, Aspergillus oryzae were studied and the minimum inhibitory concentrations were measured to be 0.5, 1.0, 1.0, 1.0, 4.0, 1.0, 2.0, 2.0, 1.0, 1.0 mg/mL, respectively. The results indicate that the flavones in Zanthoxylum nitidum (Roxb.) DC possesses strong antimicrobial activity and potentially will be useful for the development of new chemotherapeutic agents against microbial infections.

Abstract: A strong fibrin-specific fibrinolytic enzyme was produced by liquid culture of Coprinus comatus YY-20. Soybean cake powder and sucrose as substrates resulted in the highest fibrinolytic activity. The optimal temperature for the production of the enzyme was found to be 21-25°C in the optimal medium (Soybean cake powder 50 g/L, sucrose 20 g/L). The optimal initial pH of the medium was found to be at the range of 5-8. The maximum fibrinolytic activity was observed at the stationary phase of cell growth. These results suggest that the culture liquid of Coprinus comatus YY-20 has potential as a source of physiologically active fibrinolytic enzymes.

Abstract: The quaternized of N-aryl chitosan (CTS) derivatives containing different aromatic moieties were synthesized by two steps, N-aromatic Schiff and the quaternization. The chemical structures of all chitosan derivatives, N-vanillin Schiff’s base chitosan (NVCh), N-cinnamaldehyde Schiff’s base chitosan (NCCh), N-benzaldehyde Schiff’s base CTS (NBCh), and their quaternized of N-aromatic CTS derivatives were characterized by ATR-FTIR. The water solubility of the N-aromatic Schiff’s base CTS derivatives had very poor water solubility. But after quaternized, the water solubility of CTS derivatives was obviously improved. The antibacterial studies of these CTS derivatives were carried out by the inhibition zone diameters methods against E.coli (Gram-negative), S.aurueus and P.aeruginosa (Gram-positive) bacteria, and against V.Aspergillus niger (fungal). It was found that the quaternized NVSCTS showed higher antibacterial activity than quaternized NCCh and quaternized NVBCh at the almost same DQ and ES level. In comparison to each of the chemical structure, it was found that the phenol hydroxyl group effect on antibacterial activity was even higher than that of positive charge density of CTS.

Abstract: Response surface methodology (RSM) was used for statistical optimization of fermentation medium that influenced the yield of endo-polysaccharide from cultivated mycelia of Cordyceps militaris. First, the Plackett-Burman design was used to evaluate the effects of ten variables including glucose, maltose, peptone, yeast extract, KH2PO4, MgSO4, CaCl2, VB1, inoculum density and medium capacity. Among these variables, glucose, peptone and yeast extract were identified to have the significant effects. Subsequently, response surface methodology based on a five-level three-factor central composite design was employed to determine the maximum dry weight (DW) of mycelial biomass at optimum concentration of glucose, peptone and yeast extract. The mycelia growth was found to correlate to the three parameters that could be represented by second-order polynomial models. The optimal values of the three parameters were determined as 4.62% glucose, 3.36% peptone and 0.43% yeast extract. The prediction DW was 23.727g/L. The actual experimental results were in agreement with the prediction.

Abstract: Transparent-component-decimation (TCD) method may simplify the aperiodic sequences to the simplest form and one can obtain the transmissive characteristics without complicated calculations. Applying this method to the Family A of Generalized Thue-Morse [FAGTM(n)] aperiodic superlattices, we obtain directly the formulas of the transmission coefficients at the central wavelength. The results are in accord with the previous published results. It shows that the TCD method can be used to study optical transmission normally through aperiodic multilayers directly and exactly and has bright future.

Abstract: The humic acids in young coal are complex compounds of aromatic-fatty group organic acid with content of functional groups like carboxy, phenolic hydroxyl group, benzoquinonyl, alcohol group , ketone group etc. The pharmacology research of humic acid advanced in slow progress as a result of composition complexity and raw material multiplicity. At first it was analysed that terpene, steroids and other bioactive substances existed in natural humic having effects on antibacterial, antiviral, antitumor and microcirculation improvement. A new way of molecular weight determination for fulvic acid was established by modification of cryoscopic constant which was proved by the detection of capillary electrophoresis and LC-MS then. In terms of Fulvic acid which molecular weight of 300-500, pharmacology of humic acid （FA/HA）- pyrones, humic acid (FA)- catechin, humic acid (FA)-saccharide metabolism of insulin, humic acid (FA)-allantoin-glycoconjugates,humic acid (FA)-glycyron-glycoconjugates which are prepared through selective degradation and branching modification were illustrated with similar pharmacophore (functional group) of Terpenoids, steroids by MTT experiment and flow cytometer.