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In order to study the anti-fatigue effect of Angelica polysaccharide (APS) on mice, the experimental mice were randomly divided into the swimming control group, the sedentary control group, the high dosage group of polysaccharide (750 mg·kg-1), middle dosage group (500 mg·kg-1) and low dosage group (250 mg·kg-1). The mice in the drug group were treated with intragastric administration for 28 days, and the mice in the control group were treated with the same volume of normal saline. Then, the changes of body weight and the contents of blood urea nitrogen, blood lactic acid, hepatic glycogen, muscle glycogen, glutamic acid and γ-aminobutyric acid in the brain of mice in each group were measured after the swimming test. The results showed that ASP had no significant effect on the body weight of mice (P＞0.05). APS in each dosage group could significantly prolong the exhaustive swimming time of mice (P＜ 0.05). ASP at the dosage of 250-750 mg·kg-1 reduced the accumulation of blood lactic acid and urea nitrogen in mice after exercise (P＜0.01). The low dosage of APS could significantly promote the increase of glutamic acid level and the decrease of γ-aminobutyric acid level in the hindbrain of mice after the exhaustive exercise for 60 min (P＜0.05), and the ratio of GLU to GABA increased with the increase of APS dosage. APS at the dosage of 750 mg·kg-1 significantly enhanced the storage of hepatic glycogen in mice (P＜0.05). In conclusion, the analysis showed that a certain dose of angelica polysaccharide could effectively reduce the central and peripheral fatigue in mice. [ABSTRACT FROM AUTHOR]

Co re-shell nanoparticles Au@ Ag composite is synthesized by loading Ag on the surface of nano-Au as the core. The properties of the Au© Ag coreshell NPs are characterized by TEM, EDX and UV-vis. The catalytic hydrogenation activity of the material is studied with methyl orange as the target pollutant, and its catalytic mechanism is preliminarily discussed. The photoinhibition activity and antibacterial mechanism of the bacteria are studied using Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as the model bacteria. The results indicate that compared with nano-Ag, the degradation rate of nano-Au@ Ag for methyl orange is more than 99% within 8 min, and the hydrogenation products are sodium p-aminobenzenesulfonate and p--diamino--benzene. The antibacterial experiments show that compared with the dark environment, the nano-Au @ Ag under 3()() W illumination had stronger antibacterial properties. At the concentration of 30()/ig/mL, the antibacterial efficiency is higher under the illumination of 8 min. The effect on the growth stages of bacterial retardation and logarithmic phase is obvious, and the cell wall of E. coli is seriously damaged. [ABSTRACT FROM AUTHOR]

Accumulation of heavy metals in agricultural soils tends to increase crop uptake of heavy metals, and can adversely impact human health through food chains. In this study, we assessed the tea quality, heavy metal status, and the potential ecological risk of tea plantation soils and leaves in Hanzhong city, southern Shaanxi province, China. A total of 330 topsoil samples and 33 leaves samples were collected to analyze the concentrations of seven heavy metals (Pb, Zn, Cu, Cr, Hg, As, and Cd) and the pH level. Also, the tea quality and the content of heavy metals in tea leaves and leachate in 33 leaves samples were determined and analyzed. Results showed that the contents of tea polyphenols ranged from 22.23% to 27.55%, and the mean content of polyphenols was 25.58%. The contents of catechins ranged from 18.48% to 22.37%, the mean content of catechins was 20.74%. The contents of free amino acids ranged from 3.37% to 6.42%, and the mean amount of free amino acids was 4.86%. The contents of theanine ranged from 1.70% to 3.18%, and the mean content of theanine was 2.45%. The contents of heavy metals in tea leaves ranged from 0.02 mg/kg to 0.19 mg/kg for Cd, 3.18 mg/kg to 20.16 mg/kg for Cu, 0.04 mg/kg to 2.65 mg/kg for Pb, 0.09 mg/kg to 4.89 mg/kg for Cr, 0.02 mg/kg to 0.30 mg/kg for Hg, 0.66 mg/kg to 1.16 mg/kg for As, 34.82 mg/kg to 55.38 mg/kg for Zn. The heavy metals in tea leave samples almost conform to the relevant standards of pollution-free food tea except that the content of Hg in one sample exceeded the relevant standards of pollution-free food tea of 1.66%. The content of Cu was conformed to the relevant standards of organic tea. Among the contents of seven heavy metals, only Zn, Cu, and Cr were detected in the leaching solution, and the average leaching rates were 32.65%, 24.96%, and 10.50%, respectively. The soil analysis showed that the contents of heavy metals in soils ranged 0.03-0.32 mg/kg for Cd, 7.48-29.03 mg/kg for Cu, 2.45-29.16 mg/kg for Pb, 0.83 -27.76 mg/kg for Cr, 0.08-0.38 mg/kg for Hg, 2.31-13.97 mg/kg for As, 25.73-146.94 mg/kg for Zn. The averaged contents of Cd, Cu, Pb, Cr, Hg, As, and Zn were 0.11,16.42, 10.03, 12.38, 0.20, 6.89, and 87.61 mg/kg, respectively. The coefficient of variation of the different elements ranged from 29.16% to 52.24% and was 49.30% for Cd and 48.55% for Hg. In 5.76% of the samples, Cd concentrations exceeded the risk screening value of the environmental quality agricultural land soil pollution risk control standard (GB 15618–2018). The average single pollution index of Pb, Zn, Cu, Cr, Hg, As, and Cd were 2.32, 0.83, 4.26, 0.41, 44.46, 9.37, and 33.89, only the average single pollution index of Hg was over 40. The comprehensive potential ecological risk index ranged from 23.58 to 226.90, and the average potential ecological risk index was 95.4, the total samples at a low level of potential ecological risk. Thus, the tea plantations were in a low potential ecological risk level and good quality of tea leaves for 33 samples. [ABSTRACT FROM AUTHOR]