Preliminary structure and bioactivities of polysaccharide SMWP-U&E isolated from Salvia miltiorrhiza Bunge Residue.

The fractional polysaccharide SMWP-U&E was isolated from Salvia miltiorrhiza residue. SMWP-U&E consists of 91.40% carbohydrates and has an average molecular weight of 5.07 × 105 Da. The polysaccharides are mainly composed of arabinose (Ara), fructose (Fru), mannose (Man), glucose (Glc), and galactose (Gal), and their mole percentages are 3.72%, 4.11%, 6.18%, 32.08% and 53.91%, respectively. When effected on weaned piglets, 1.5 g/kg SMWP-U&E supplementation significantly increased the villus height to crypt depth ratio in ileum. PCR-denaturing gradient gel electrophoresis and qRT-PCR results indicated that SMWP-U&E supplementation could change the density of intestinal microbiota and the populations of Lactobacillus and Escherichia coli in jejunum, ileum, caecum, and colon. The supplementation also increased contents of IgA, IgG, IgM, IL-2, IFN-γ, and IL-10; promoted T-AOC and SOD activities; and reduced MDA level in the serum. These findings suggest that SMWP-U&E improves digestion and nutrient absorption in weaned piglets, exerts beneficial effects on intestinal morphology and microflora, and enhances the immune and antioxidant capabilities in mode of weaned piglets. Thus, SMWP-U&E exhibits potential as a new type of plant-derived additive and novel prebiotics.

Extraction and antioxidant activities of polysaccharides from roots of Arctium lappa L.

Polysaccharides were extracted from the roots of Arctium lappa L. (ALPs) using response surface methodology with ultrasonication. A central composition design was used to optimize extraction parameters by maximizing the polysaccharide extraction yield. The modified optimal conditions were as follows: water to raw material ratio of 31 mL/g, ultrasonic power of 158 W, extraction time of 83 min, and extraction temperature of 50 °C. Furthermore, fractions of ALP40-1, ALP60-1, and ALP80-1 were obtained for chemical and antioxidant activity analyses after purification. Results indicated that the three fractions had a molecular weight of 218, 178, and 60 kDa, respectively, and were composed of mannose, glucose, fructose, and galactose. ALP60-1 exhibited strong scavenging activities on 1,1­diphenyl­2­picryhydrazyl, hydroxyl, and superoxide radicals. These results demonstrate that ultrasonic-assisted extraction is a very effective method for extracting ALPs, and ALP60-1 is a potential novel natural antioxidant. However, further structure elucidation and in vivo experiments are required.

A Fiber Bragg Grating-Based Dynamic Tension Detection System for Overhead Transmission Line Galloping.

Galloping of overhead transmission lines (OHTLs) may induce conductor breakage and tower collapse, and there is no effective method for long distance distribution on-line galloping monitoring. To overcome the drawbacks of the conventional galloping monitoring systems, such as sensitivity to electromagnetic interference, the need for onsite power, and short lifetimes, a novel optical remote passive measuring system is proposed in the paper. Firstly, to solve the hysteresis and eccentric load problem in tension sensing, and to extent the dynamic response range, an 'S' type elastic element structure with flanges was proposed. Then, a tension experiment was carried out to demonstrate the dynamic response characteristics. Moreover, the designed tension sensor was stretched continuously for 30 min to observe its long time stability. Last but not the least, the sensor was mounted on a 70 m conductor model, and the conductor was oscillated at different frequencies to investigate the dynamic performance of the sensor. The experimental results demonstrate the sensor is suitable for the OHTL galloping detection. Compared with the conventional sensors for OHTL monitoring, the system has many advantages, such as easy installation, no flashover risk, distribution monitoring, better bandwidth, improved accuracy and higher reliability.

An affinity improved single-chain antibody from phage display of a library derived from monoclonal antibodies detects fumonisins by immunoassay.

Fumonisin B analogs, particularly FB1, FB2, and FB3, are major mycotoxins found in cereals. Single-chain fragment variable (scFv) antibodies represent a promising alternative immunoassay system. A phage-displayed antibody library derived from four monoclonal antibodies (mAbs) generated against FB1 was used to screen high binding affinity scFv antibodies; the best candidate was designated H2. Surface plasmon resonance measurements confirmed that the H2 scFv displayed a 82-fold higher binding affinity than its parent mAb. Direct competitive enzyme-linked immunosorbent assay demonstrated that the H2 antibody could competitively bind to free FB1, FB2, and FB3, with an IC50 of 0.11, 0.04, and 0.10 µM, respectively; it had no cross-reactivity to deoxynivalenol, nivalenol and aflatoxin. Validation assays with naturally contaminated samples revealed a linear relationship between the H2 antibody-based assay results and chemical analysis results, that could be expressed as y=1.7072x+5.5606 (R(2)=0.8883). Homology modeling of H2 revealed a favorable binding structure highly complementary to the three fumonisins. Molecular docking analyses suggested that the preferential binding of the H2 scFv to FB2 was due to the presence of a hydrogen radical in its R1 position, leading to a proper electrostatic matching and hydrophobic interaction. The H2 scFv antibody can be used for the rapid, accurate, and specific detection of fumonisin contamination in agricultural samples.

Effect of inoculation with the endophyte Clavibacter sp. strain Enf12 on chilling tolerance in Chorispora bungeana.

Endophytic bacteria have been shown to increase resistance against biotic stress and tolerance to abiotic stress in many plants. The objective of this study was to evaluate the effect of an endophytic bacterium, Clavibacter sp. strain Enf12, in regenerated plantlets of Chorispora bungeana subjected to chilling stress (0°C). Aerial biomass and physiological markers for chilling stress, such as electrolyte leakage, lipid peroxidation, reactive oxygen species (ROS) accumulation, proline content and activities of superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6), guaiacol peroxidase (EC 1.11.1.7) and ascorbate peroxidase (EC 1.11.1.11), were assessed. We demonstrated that Clavibacter sp. strain Enf12 was capable of colonizing internal tissues of regenerated plantlets of C. bungeana and maintained stable population densities under both normal (20°C) and chilling (0°C) conditions. Inoculation enhanced plantlet growth under both conditions and significantly attenuated the chilling-induced electrolyte leakage, lipid peroxidation and ROS accumulation. The endophyte significantly increased the activities of antioxidant enzymes and proline content in C. bungeana plantlets under chilling stress. These findings suggest that Clavibacter sp. strain Enf12 inoculation stimulates the growth of C. bungeana plantlets and improves their tolerance to chilling stress through enhancing the antioxidant defense system.