Advanced Materials Research Vols. 343-344

Abstract: Citrus. reticulata Blanco cv. Suavissima friut has long been regarded as a food and medicinal plant. We investigated the antioxidant activity of the ethanol extract of peel and pulp part of fruit growned in Zhejiang Province, PR. China by several in-vitro systems of assay, namely DPPH radical-scavenging activity, ABTS.+ radical-scavenging activity, ferric reducing antioxidant power (FRAP) assay. Total phenolic content was measured by Folin-Ciocalteu reagent. The total flavonoids contents were measured using a modified colorimetric method.The extracts of different samples were found to have different levels of antioxidant activity in the systems tested. Ethanol extracts of the fruit showed stronger antioxidant activities compared with those of the commercial compound (Trolox). The results suggest that Citrus. reticulata Blanco cv. Suavissima friut can be a good source of natural antioxidant.

Abstract: The contents of total flavonoid(TF) and total phenolic acid(TPA) in ethanol extracts from bamboo leaves of 21 species of Phyllostachys were determined, and the scavenging effects of ethanol extracts from bamboo leaves on DPPH and ABTS were also studied. The results showed that the ethanol extracts from bamboo leaves of 20 species of Phyllostachys contained rich flavonoid and phenolic acid, total content of which were respectively 8.963 mg/g～28.0614 mg/g and 12.3767 mg/g～31.8915 mg/g. Through the studies of antioxidant activities, it indicated that ethanol extracts of different bamboo species all had potent antioxidant activities, which was positively correlated with total flavonoids and phenolic acid. This paper provided a scientific basis for the research of active constituent and the exploitation of bamboo leaves from different species.

Abstract: Purifying efficiency and culture performance in a recirculating aquaculture system (RAS) combined with subsurface flow wetland (SFW) were investigated in this paper. The results showed that the wetland effectively removed total suspended solids (78.6%), chemical oxygen demand (49.2%), 5-day biochemical oxygen demand (70.4%), total ammonia (53.7%) and nitrite (64.7%) from the aquaculture effluents at a hydraulic loading rate of 344 mm/d. The channel catfish (Ictalurus punctatus) with initial length of 18.97±2.92 cm were reared for 223 days in three recycling ponds at different stocking densities (0.055, 0.109, and 0.164 kg/m3) and a control pond at stocking density 0.055 kg/m3. Fish were fed to satiation twice daily with a commercial diet and the amount fed was measured to determine feed efficiency (FE). In the recycling ponds, fish growth appeared to be negatively correlated with stocking density, in which total weight gain of fish ranged from 374.9% to 886.7%. Fish in the control pond had low survival rate (61.1%) and total weight gain (465.2%), comparing with the recycling pond which had same stocking density (0.055 kg/m3). Feed efficiency (0.34) of the control pond was also significantly lower than that of the 0.055 kg/m3 treatment (0.96). A logistic model of was employed to simulate the growth of channel catfish. The estimated parameters and predicted results showed that the growth rate of channel catfish reared in recycling pond is significantly higher than that in static pond.

Abstract: Berberine, as an allelochemical extracted from golden thread (Coptis chinensis), inhibits the growth of Microcystis aeruginosa significantly. To assess berberine-induced damage on the algal photosynthetic apparatus, the effects of berberine on the algal photosynthetic pigments compositions and ultrastructure were investigated. The results showed that the relative chlorophyll a content of M. aeruginosa decreased with the increasing concentrations of berberine and the prolongation of exposure time. The relative contents of phycocyanin, allophycocyanin and phycoerythrin of M. aeruginosa transitioned from a decrease to an increase in the early phase of the experiment, and then decreased sharply to the end at low concentrations. However, when berberine concentration raised to 20.0 mg·L-1, all the relative phycobilins contents of M. aeruginosa had been decreasing with the prolongation of exposure time. Of the three phycobilins of M. aeruginosa, phycocyanin was affected most severely by berberine. TEM photographs showed that the ultrastructures of the multiple-layered cell wall, cell membrane and thylakoid lamella of M. aeruginosa were destroyed severely under the stress of berberine with the occurrence of cyanophycin granules. It was concluded that decreases in the photosynthetic pigments and destruction of the algal cells ultrastructures might be involved in berberine-caused antialgal mechanism.

Abstract: 576 broilers are experimented on with 6 × 2 (Zn × vitamin A) repetitive experiment in attempt to study the influence of different dietary zinc levels (40,80 ,120 ,160 ,200 and 320 mg/ kg) and dietary vitamin A levels (2700 and 8800 IU/ kg) on vitamin A metabolism, zinc concentration in liver and tibia, zinc apparent deposition rate, serum ALK activity, CuZn-SOD activity in liver and serum, and serum insulin concentration. Results showed that vitamin A concentration in serum increased with the increasing of zinc level in the diet, and that in livers decreased accordingly, which means that zinc can mobilize vitamin A of liver into serum. When dietary zinc level was 320 mg/kg, vitamin A concentration in serum, liver and kidney increased at the same time, perhaps higher dietary zinc level promoted vitamin A absorption except for mobilizing it into serum. Higher dietary vitamin A level (8800 IU/kg) increased zinc concentration in liver and tibia slightly. Zinc apparent deposition rate increased with the increasing of dietary zinc level within certain range and then decreased.；dietary Zinc level has a prominent influence on CuZn – SOD in serum when P < 0. 01; and the result also shows that dietary zinc level, vitamin A level and their interaction has a respectively prominent influence on ALK, serum insulin concentration is also apparently affected.

Abstract: Due to size limits in the transverse direction, tensile testing is not appropriate to investigate the mechanical properties of elytra cuticle of the dung beetle (Copris ochus Motschulsky). However, nanoindentation testing can determine a material’s anisotropic properties through a single indentation. In the present study, nanoindentation stress–strain curves were used to characterize the complete mechanical behavior of dung beetle elytra cuticle. A differential constitutive equation has been developed with time-dependent spring constants k and viscosities η . To describe the complex viscoelastic behavior of dung beetle cuticle, a descriptive representation of the linear viscoelasticity law for the multilayer matrix has been formulated. A qualitative model for the relationship between cuticle structure and mechanical properties of elytra may help develop bionic composite materials for micro-aircraft, bionic tribology, bionic medical apparatus, and bionic organs (tissue engineering).

Abstract: Samples on a regular basis, and the use of SDSPAGE and Western Blotting methods was inspected to express situation in the induction of heat shock protein (both Hsp27 and Hsp40) of the body tissue of earthworms (Eisenia foetide) exposed in the soil by respectively adding Atrazine, Chlorotoluron; Acetochlor, Butachlor. According to the gel imaging system for gray-scale scanner, with the increase of the concentration of herbicides, the relative expression of both Hsps showed the phenomenon of induction in low concentration and suppression in high concentrations within the range of tested concentration. With the extension of the processing time, both Hsps were first induced suppression of the general trend and there was good exposure time – coercing effect relationship. The relative expression of HSP27 and HSP40 exposed by Atrazine, Chlorotoluron, Acetochlor and Butachlor were 2.21, 1.98, 2.06, 2.11 times and 2.32, 1.99, 2.15, 2.24 times of the control group. The sensitive ability of the organization of HSP27 and HSP40 to four herbicides was in the order of Atrazine > Butachlor > Acetochlor > Chlorotoluron. The relative expression of Hsp40 slightly was a little bit larger than Hsp27.

Abstract: The effects of low non-lethal levels of heavy metals (Pb and Cd) on biomass allocation, relationship between vegetative biomass and reproductive biomass, and heavy metal distributions in plant were investigated for three varieties of maize (Zea mays L.). Results showed that significant two-way interactions between variety and heavy-metal application were the main source of variation of biomass allocation. Different levels of Pb and Cd applications did not cause relatively more biomass to be allocated reproductive biomass in three varieties, indicating that heavy-metal applications did not change the reproductive allometry. Although the concentrations of Pb and Cd in grains were lower than other organs, Pb and Cd concentrations of grains under higher heavy-metal treatments exceeded the national guidance limit for three varieties of maize, suggesting heavy metal pollution may pose risks to human health.

Abstract: In this study, we invesgated the mechanical properties of the rabbit femurs fixed with calcium phosphate cement (CPC). Twenty adult rabbits were randomly divided into the control group and the group treated with femur fracture artifically, then fixed with CPC. Two weeks after surgery, all rabbits were sacrificed, and femurs were removed for the three point bending test to examine the changes of mechanical parameters of the femurs. Our results showed that although the maximum tension stress of the femurs in the treatment group was smaller than the control, its crosss-sectional area became bigger, which improved the ablity of the femur to bear more loading with the maximum pressure and absorbed energy during destroy up to 83.5% and 64.3% of normal bone material strength. It indicated that it was practicable to fix the fractured femur with CPC from the biomechanical view piont.

Abstract: The mung bean is popular in the Orient for use in cakes and soups and as bean sprouts. In our research, it was found that aromatic flavor could be generated when the mung bean soup was acidified to pH 1.5 close to the acidic value of stomach. GC-MS analysis was performed to identify these molecules associated with aromatic flavor. The results showed molecules including 1, 2, 3, 4-tetrahydro-1, 1, 6-trimethyl-Naphthalene and 2-ethyl-N-(2 ethylhexyl)-1- Hexanamine were merely produced by acidified mung bean soup, which could probably involve in the generation of aromatic flavor. In addition, studies also showed that volatile molecules from acidified mung bean soup could keep the DA level in the Drosophila brain stable under starvation stress.