Characteristics of antioxidant substances and identification of antioxidant peptides in duck embryo eggs.

1. Oxidative stress in duck embryos undergoes dynamic change during incubation. However, the detailed change characteristics has not been studied yet. Here, we explored the dynamic change characteristics of different antioxidant substances in duck embryo eggs during incubation.2. The following trial assayed antioxidant substances, including vitamins E (VE) and C (VC), glutathione (GSH), reduced glutathione (reduced GSH), oxidative glutathione (GSSG), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-px), and malonic dialdehyde (MDA). Five antioxidant peptides (DY1, DY2, DY3, DY4 and DY5) were screened and their protective effect on HepG2 cells and their mechanism of action determined.3. The results showed that antioxidant substances underwent a dynamic change during incubation through various mechanisms. Moreover, the T-AOC of duck embryos at different incubation times, firstly increased and then decreased, reaching the highest level on d 15 during incubation. The peptide DY2 (TVDGPSGKLWRD) exhibited high antioxidant activity in vitro, and is known to regulate the apoptosis pathway in mitochondria.4. The data indicated that duck embryos can be used for the development of related antioxidant products and purification of new bioactive peptides.

Gapless Spin-Liquid Ground State in the S=1/2 Kagome Antiferromagnet.

The defining problem in frustrated quantum magnetism, the ground state of the nearest-neighbor S=1/2 antiferromagnetic Heisenberg model on the kagome lattice, has defied all theoretical and numerical methods employed to date. We apply the formalism of tensor-network states, specifically the method of projected entangled simplex states, which combines infinite system size with a correct accounting for multipartite entanglement. By studying the ground-state energy, the finite magnetic order appearing at finite tensor bond dimensions, and the effects of a next-nearest-neighbor coupling, we demonstrate that the ground state is a gapless spin liquid. We discuss the comparison with other numerical studies and the physical interpretation of this result.

Effects of sorghum distillers dried grains with solubles on the carcass characteristics and muscle quality of China Micro Duck drakes aged from 4 to 8 weeks.

A study was conducted to determine the effects of feeding sorghum distiller's dried grains with solubles (SDDGS) on carcasses characteristics (live weight, whole net carcass rate, breast muscle percentage, thigh muscle percentage), muscle quality (meat color, shear stress, cooking loss rate, cooked meat percentage), and meat composition of China Micro Duck (CMD) drakes aged from 4 to 8 wk. A total of 240 CMD drakes (aged 4 wk and initial weight was 496.7 g) were randomly allotted to one of 4 dietary treatments in randomized complete block design. The 4 treatments were S0(the control group, S5, S10, S15, indicating the dietary content of SDDGS (zero, 5,10 and 15%, respectively). Each treatment with 60 drakes was equally divided into 6 repeated test groups, each group with 10 drakes. The results showed that S5, S10, and S15 could decrease the thigh muscle percentage linearly (P < 0.01); however, there was no significant (p > 0.05) effect on other carcass characteristic and muscle quality indexes of live body weight (BW), whole net carcass yield (WNCY), breast muscle percentage (BMP), breast muscle color (BMC), thigh muscle color (TMC), breast shear strength (BSS), cooking loss (CL), or cooked meat percentage (CMP). For meat composition, the increasing level of SDDGS caused a linear and quadratic decrease (P < 0.01) of crude protein and a linear and quadratic (P < 0.01) increase of crude fat of thigh and breast muscle, while breast muscle ash was not significantly affected (P > 0.05). Overall, this study revealed that in the 3 kinds of diets with SDDGS, S5 had the least negative impact on carcass characteristics, muscle quality, and meat composition.

[Study of direct determining animal and plant oil in sewage by ultraviolet spectrophotometry method].

In this paper, the trace oil in sewage have been emulsified with S-T emulsifier and determined by ultraviolet spectrophotometry. Under normal temperature, the oil even dispersed in sewage with S-T emulsifier. It is stable and direct determined without separation. The oil is from sewage. The linear range is 0-92 micrograms.mL-1, and rate of recovery is 89%-129%. The method is quick and simple.