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Microwave‐assisted extraction was employed to extract polyphenols from the leaf of Magnolia kwangsiensis Figlar & Noot . The yield of polyphenols was 2.44±0.02 % under the optimal conditions of RSM: acetone concentration of 70 %, ratio of solvent to material of 21 mL?g?1 and extraction time of 16 min. The antioxidant activities were evaluated in terms of total antioxidant ability, reducing power, DPPH ? and ? OH scavenging activity. Results showed the polyphenols presented potential antioxidant activities, especially the stronger scavenging activity on ? OH. In term of ? OH scavenging activity, the IC50 value of NKA‐9 purification was 0.335 mg mL?1, equivalent to 35.23 % of VC. The IC50 values of crude extract and ethyl acetate extract were 0.580 and 0.828 mg mL?1, equivalent to 60.99 % and 87.07 % of VC. Results indicated that M. kwangsiensis leaf polyphenols present potential antioxidant activities that make it beneficial for human health by preventing or reducing oxidative damage. 相似文献
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Lifang Yang Jipeng Ma Ying Tan Qijun Zheng Maolong Dong Wei Guo Lize Xiong Jian Yang Jun Ren 《Journal of cellular and molecular medicine》2019,23(7):4640-4652
Hypertension contributes to the high cardiac morbidity and mortality. Although oxidative stress plays an essential role in hypertensive heart diseases, the mechanism remains elusive. Transgenic mice with cardiac overexpression of metallothionein, a heavy metal‐binding scavenger, were challenged with NG‐nitro‐L‐arginine methyl ester (L‐NAME) for 14 days prior to measurement of myocardial contractile and intracellular Ca2+ anomalies as well as cell signalling mechanisms using Western blot and immunofluorescence analysis. L‐NAME challenge elicited hypertension, macrophage infiltration, oxidative stress, inflammation and cardiac dysfunction manifested as increased proinflammatory macrophage marker F4/80, interleukin‐1β (IL‐1β), intracellular production, LV end systolic and diastolic diameters as well as depressed fractional shortening. L‐NAME treatment reduced mitochondrial membrane potential (MMP), impaired cardiomyocyte contractile and intracellular Ca2+ properties as evidenced by suppressed peak shortening, maximal velocity of shortening/relengthening, rise in intracellular Ca2+, along with elevated baseline and peak intracellular Ca2+. These unfavourable mechanical changes and decreased MMP (except blood pressure and macrophage infiltration) were alleviated by overexpression of metallothionein. Furthermore, the apoptosis markers including BAD, Bax, Caspase 9, Caspase 12 and cleaved Caspase 3 were up‐regulated while the anti‐apoptotic marker Bcl‐2 was decreased by L‐NAME treatment. Metallothionein transgene reversed L‐NAME‐induced changes in Bax, Bcl‐2, BAD phosphorylation, Caspase 9, Caspase 12 and cleaved Caspase 3. Our results suggest that metallothionein protects against L‐NAME‐induced myocardial contractile anomalies in part through inhibition of apoptosis. 相似文献
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Yang Bin Zhou Jiatao Zhao Hui Wang Anling Lei Yuanjun Xie Qiuling Xiong Sheng 《Bioprocess and biosystems engineering》2019,42(5):799-806
Bioprocess and Biosystems Engineering - Stable transfection of mammalian cells using various expression cassettes for exogenous gene expression has been well established. The impact of critical... 相似文献
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Jun Cheng Mengmeng Zhang Bin Tan Yajun Jiang Xianbo Zheng Xia Ye Zijing Guo Tingting Xiong Wei Wang Jidong Li Jiancan Feng 《Plant biotechnology journal》2019,17(9):1723-1735
Plant stature is one important factor that affects the productivity of peach orchards. However, little is known about the molecular mechanism(s) underlying the dwarf phenotype of peach tree. Here, we report a dwarfing mechanism in the peach cv. FenHuaShouXingTao (FHSXT). The dwarf phenotype of ‘FHSXT’ was caused by shorter cell length compared to the standard cv. QiuMiHong (QMH). ‘FHSXT’ contained higher endogenous GA levels than did ‘QMH’ and did not response to exogenous GA treatment (internode elongation). These results indicated that ‘FHSXT’ is a GA‐insensitive dwarf mutant. A dwarf phenotype‐related single nucleotide mutation in the gibberellic acid receptor GID1 was identified in ‘FHSXT’ (GID1cS191F), which was also cosegregated with dwarf phenotype in 30 tested cultivars. GID1cS191F was unable to interact with the growth‐repressor DELLA1 even in the presence of GA. ‘FHSXT’ accumulated a higher level of DELLA1, the degradation of which is normally induced by its interaction with GID1. The DELLA1 protein level was almost undetectable in ‘QMH’, but not reduced in ‘FHSXT’ after GA3 treatment. Our results suggested that a nonsynonymous single nucleotide mutation in GID1c disrupts its interaction with DELLA1 resulting in a GA‐insensitive dwarf phenotype in peach. 相似文献
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Yuan Xiong Yi Wang Xue Han Yao Ma Han Fang Zhu YunFei Long Shu Chen 《Luminescence》2019,34(7):724-730
The reduction of nuclear fast red (NFR) stain by sodium tetrahydroboron was catalyzed in the presence of silver ions (Ag+). The fluorescence properties of reduced NFR differed from that of NFR. The product showed fluorescence emission at 480 nm with excitation at 369 nm. Furthermore, the fluorescence intensity of the mixture increased strongly in the presence of Ag+ and Britton–Robinson buffer at pH 4.78. There was a good linear relationship between increased fluorescence intensity (ΔI) and Ag+ concentration in the range 5.0 × 10?9 to 5.0 × 10?8 M. The correlation coefficient was 0.998, and the detection limit (3σ/k) was 1.5 × 10?9 M. The colour of the reaction system changed with variation in Ag+ concentration over a wide range. Based on the colour change, a visual semiquantitative detection method for recognition and sensing of Ag+ was developed for the range 1.0 × 10?8 to 5.0 × 10?4 M, with an indicator that was visible to the naked eye. Therefore, a sensitive, simple method for determination of Ag+ was developed. Optimum conditions for Ag+ detection, the effect of other ions and the analytical application of Ag+ detection of synthesized sample were investigated. 相似文献
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Xiaoxue Lv Tianyu Lei Bojun Wang Wei Chen Yu Jiao Yin Hu Yichao Yan Jianwen Huang Junwei Chu Chaoyi Yan Chunyang Wu Jianwei Wang Xiaobin Niu Jie Xiong 《Liver Transplantation》2019,9(40)
Due to unprecedented features including high‐energy density, low cost, and light weight, lithium–sulfur batteries have been proposed as a promising successor of lithium‐ion batteries. However, unresolved detrimental low Li‐ion transport rates in traditional carbon materials lead to large energy barrier in high sulfur loading batteries, which prevents the lithium–sulfur batteries from commercialization. In this report, to overcome the challenge of increasing both the cycling stability and areal capacity, a metallic oxide composite (NiCo2O4@rGO) is designed to enable a robust separator with low energy barrier for Li‐ion diffusion and simultaneously provide abundant active sites for the catalytic conversion of the polar polysulfides. With a high sulfur‐loading of 6 mg cm?2 and low sulfur/electrolyte ratio of 10, the assembled batteries deliver an initial capacity of 5.04 mAh cm?2 as well as capacity retention of 92% after 400 cycles. The metallic oxide composite NiCo2O4@rGO/PP separator with low Li‐ion diffusion energy barrier opens up the opportunity for lithium–sulfur batteries to achieve long‐cycle, cost‐effective operation toward wide applications in electric vehicles and electronic devices. 相似文献