Phomopsis longanae Chi-Induced Change in ROS Metabolism and Its Relation to Pericarp Browning and Disease Development of Harvested Longan Fruit

Phomopsis longanae Chi is a major pathogenic fungus that infects harvested longan fruit. This study aimed to investigate the effects of P. longanae on reactive oxygen species (ROS) metabolism and its relation to the pericarp browning and disease development of harvested longan fruit during storage at 28°C and 90% relative humidity. Results showed that compared to the control longans, P. longanae-inoculated longans displayed higher indexes of pericarp browning and fruit disease, higher O2-. generation rate, higher accumulation of malondialdehyde (MDA), lower contents of glutathione (GSH) and ascorbic acid (AsA), lower 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability and reducing power in pericarp. In addition, P. longanae-infected longans exhibited higher activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) in the first 2 days of storage, and lower activities of SOD, CAT, and APX during storage day 2–5 than those in the control longans. These findings indicated that pericarp browning and disease development of P. longanae-infected longan fruit might be the result of the reducing ROS scavenging ability and the increasing O2-. generation rate, which might lead to the peroxidation of membrane lipid, the loss of compartmentalization in longan pericarp cells, and subsequently cause polyphenol oxidase (PPO) and peroxidase (POD) to contact with phenolic substrates which result in enzymatic browning of longan pericarp, as well as cause the decrease of disease resistance to P. longanae and stimulate disease development of harvested longan fruit

Effects of Arsenic Trioxide-Loaded PLGA Nanoparticles on Proliferation and Migration of Human Vascular Smooth Muscle Cells

Backgroud. To evaluate improvement of arsenic trioxide-loaded PLGA nanoparticles (As2O3-PLGA-NPs) to Human Vascular Smooth Muscle Cells (HUVSMCs) in vitro. Methods. As2O3-PLGA-NPs were synthesized and characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM), and energy dispersive spectrometry (EDS), and the cumulative release rates of As2O3-PLGA-NPs were measured in vitro; HUVSMCs were treated with As2O3-PLGA-NPs in vitro. MTT assay and flow cytometry assay (FCM) were performed to examine the inhibitory effect of As2O3-PLGA-NPs on HUVSMCs and compared with As2O3 solution at various concentrations. Optical microscope was used to observe the morphological change of HUVSMCs treated with As2O3-PLGA-NPs. The expression of Bcl-2, Bax, and MMP-9 in HUVSMCs was detected by RT-PCR and Western blot (WB). Results. EDS confirmed that prepared nanoparticles contained elements of arsenic. The surface coating of the eluting stent of As2O3-PLGA-NPs has the same characteristics with our self-prepared As2O3-PLGA-NPs, and it also has a drug sustained-release character. Compared with the control group, cell proliferation and migration cell were significantly suppressed with concentration-dependent (P<0.05, respectively). Meanwhile, in concentration-dependent, As2O3-PLGA-NPs depressed mRNA and protein expression of Bcl-2 and MMP-9 and increased mRNA and protein expression of Bax. Conclusion. As2O3-PLGA-NPs had an inhibitory effect on HUVSMCs’ proliferation and migration, and it may work via regulating Bax, Bcl-2, and MMP-9 expression in vitro

Effects of a novel chitosan formulation treatment on quality attributes and storage behavior of harvested litchi fruit

The effects of Kadozan (a novel chitosan formulation) treatment on physiological attribute, nutritional quality and storage behavior of harvested “Wuye” litchi fruit were studied. Compared with control litchis, Kadozan treatment significantly decreased fruit respiration rate, retarded the increase of pericarp cell membrane permeability, maintained higher contents of anthocyanins and flavonoids and higher values of L∗, a∗ and b∗ in litchi pericarp, and reduced the decreases of titratable acidity, total soluble solids, total soluble sugars, and vitamin C contents in litchi pulp, maintaining better quality of litchis. Furthermore, Kadozan treatment decreased browning index and disease index of litchis, kept higher rate of commercially acceptable fruit, and reduced fruit weight loss, showing better storage behavior of litchis under ambient temperature. The optimal Kadozan treatment for litchis was the 1:100 (VKadozan: VKadozan + Water) dilution, which might be a promising method for keeping quality and prolonging shelf-life of harvested “Wuye” litchi fruit

Phomopsis longanae Chi-Induced Changes in Activities of Cell Wall-Degrading Enzymes and Contents of Cell Wall Components in Pericarp of Harvested Longan Fruit and Its Relation to Disease Development

The main goal of this study was to investigate the influences of Phomopsis longanae Chi infection on activities of cell wall-degrading enzymes (CWDEs), and contents of cell wall components in pericarp of harvested “Fuyan” longan (Dimocarpus longan Lour. cv. Fuyan) fruit and its relation to disease development. The results showed that, compared with the control samples, P. longanae-inoculated longans showed higher fruit disease index, lower content of pericarp cell wall materials (CWMs), as well as lower contents of pericarp cell wall components (chelate-soluble pectin (CSP), sodium carbonate-soluble pectin, hemicelluloses, and cellulose), but higher content of pericarp water-soluble pectin (WSP). In addition, the inoculation treatment with P. longanae significantly promoted the activities of CWDEs including pectinesterase, polygalacturonase, β-galactosidase, and cellulase. The results suggested that the P. longanae stimulated-disease development of harvested longans was due to increase in activities of pericarp CWDEs, which might accelerate the disassembly of pericarp cell wall components. In turn, resulting in the degradation of pericarp cell wall, reduction of pericarp mechanical strength, and subsequently leading to the breakdown of longan pericarp tissues. Eventually resulting in development of disease development and fruit decay in harvested longans during storage at 28°C

The difference of the cell wall metabolism between ‘Fuyan’ and ‘Dongbi’ longans and its relationship with the pulp breakdown

The aims of present works were to explore the difference in pulp breakdown of ‘Fuyan’ and ‘Dongbi’ longans and its relationship with cell wall metabolism. Comparison with ‘Fuyan’ longan fruit, postharvest ‘Dongbi’ longan fruit showed lower pulp breakdown index, lower activities of PE, PG, cellulase, β-Gal, XET, and lower expression levels of their corresponding genes. In addition, higher levels of cell wall polysaccharides including ISP, CSP, cellulose and hemicellulose were exhibited in ‘Dongbi’ longan pulp. These findings implied that, the reduced activities of enzymes and the down-regulated expressions of genes-involved in cell wall disassembly were shown in ‘Dongbi’ longan pulp, which might reduce the dissolution of polysaccharides and maintain a higher structural integrity in ‘Dongbi’ longan pulp cell wall, and consequently the mitigated pulp breakdown was displayed in ‘Dongbi’ longan during storage

Game-theoretical explorations of the mesoscale flow structure and regime transitions in bubble columns

Understanding the mesoscale structure and regime transition in bubble columns is of great significance for reactor design and scaleup.Based on the energy-minimization multiscale(EMMS)model,a noncooperative game model with constraints is proposed to investigate the structural properties of gas-liquid systems in which small and large bubbles are chosen as players and the energy consumption form the objective function.The conservation equations of the system can be regarded as the constraints of the game.For the formulated noncooperative game model,the concept of the generalized Nash equilibrium(GNE)is used to characterize the solution.An algorithm is developed to numerically compute the GNE and some important structural parameters in the system.The numerical results show the existence of the GNE for all values of the superficial gas velocity Ug.As Ug varies,the trends in the state variables can be observed and the critical point of Ug identified.The overall trend of the flow regime transition agrees with the original EMMS model and experimental results,although the GNE calculation also reveals different single-bubble dominant mechanisms with increasing Ug

lncRNA KRAL reverses 5-fluorouracil resistance in hepatocellular carcinoma cells by acting as a ceRNA against miR-141

Abstract Background 5-Fluorouracil (5-FU) has been widely applied to treat various types of cancers, including hepatocellular carcinoma (HCC). However, primary or acquired 5-FU resistance prevents the clinical application of this drug in cancer therapy. Herein, our study is the first to demonstrate that lower expression of KRAL, a long non-coding RNA (lncRNA), mediates 5-FU resistance in HCC via the miR-141/Keap1 axis. Methods Cell proliferation assays, western blot analysis, qRT-PCR, the dual-luciferase reporter assay and RNA immunoprecipitation were performed to investigate the mechanisms by which KRAL mediates 5-fluorouracil resistance in HCC cell lines. Results The quantitative analysis indicated that KRAL and Keap1 were significantly decreased and that Nrf2 was increased in HepG2/5-FU and SMMC-7721/5-FU cells compared with the corresponding expression levels in the respective parental cells. Overexpression of KRAL increased Keap1 expression, and inactivating the Nrf2-dependent antioxidant pathway could reverse the resistance of HepG2/5-FU and SMMC-7721/5-FU cells to 5-FU. Moreover, KRAL functioned as a competitive endogenous RNA (ceRNA) by effectively binding to the common miR-141 and then restoring Keap1 expression. These findings demonstrated that KRAL is an important regulator of Keap1; furthermore, the ceRNA network involving KRAL may serve as a treatment strategy against 5-FU resistance in hepatocellular carcinoma cells. Conclusions KRAL/miR-141/Keap1 axis mediates 5-fluorouracil resistance in HCC cell lines

Game-theoretical explorations of the mesoscale flow structure and regime transitions in bubble columns

Understanding the mesoscale structure and regime transition in bubble columns is of great significance for reactor design and scaleup. Based on the energy-minimization multiscale (EMMS) model, a noncooperative game model with constraints is proposed to investigate the structural properties of gas-liquid systems in which small and large bubbles are chosen as players and the energy consumption form the objective function. The conservation equations of the system can be regarded as the constraints of the game. For the formulated noncooperative game model, the concept of the generalized Nash equilibrium (GNE) is used to characterize the solution. An algorithm is developed to numerically compute the GNE and some important structural parameters in the system. The numerical results show the existence of the GNE for all values of the superficial gas velocity U-g. As U-g varies, the trends in the state variables can be observed and the critical point of U-g identified. The overall trend of the flow regime transition agrees with the original EMMS model and experimental results, although the GNE calculation also reveals different single-bubble dominant mechanisms with increasing U-g. (C) 2019 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved