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1.
Food Chem ; 306: 125627, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31610328

RESUMO

Effects of various concentrations of Kadozan (chitosan) treatment on storability and quality properties of harvested 'Fuyan' longans were investigated. Compared to the control samples, Kadozan treated-longans displayed lower fruit respiration rate, lower pericarp cell membrane permeability, pericarp browning index, pulp breakdown index, fruit disease index, and weight loss, but higher rate of commercially acceptable fruit, higher levels of pericarp chlorophyll, carotenoid, anthocyanin, flavonoid and total phenolics, higher amounts of pulp total soluble sugar, sucrose, total soluble solids, and vitamin C. These results revealed Kadozan treatment could increase storability and retain better quality of harvested longan fruit. Among different concentrations of Kadozan, the dilution of 1:500 (VKadozan: VKadozan + Water) showed the best results in storability and maintained the best quality of longans during storage. These findings demonstrated that Kadozan could be a facile and eco-friendly postharvest handling approach for increasing storability and lengthening shelf-life of harvested 'Fuyan' longan fruit.

2.
Food Chem ; 305: 125439, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31499287

RESUMO

Compared to the control longans, hydrogen peroxide (H2O2)-treated longans exhibited higher index of pulp breakdown, higher fruit respiration rate, higher activities of pulp phosphohexose isomerase (PGI), succinate dehydrogenase (SDH), cytochrome C oxidase (CCO), ascorbic acid oxidase (AAO) and polyphenol oxidase (PPO), but lower activity of pulp nicotinamide adenine dinucleotide kinase (NADK). H2O2-treated longans also exhibited lower total activities of pulp glucose-6-phosphate dehydrogenase (G-6-PDH) and 6-phosphogluconate dehydrogenase (6-PGDH), lower levels of pulp NADP(H), but higher levels of pulp NAD(H). These data indicated that H2O2-stimulated longan pulp breakdown was owing to a decreased proportion of pentose phosphate pathway (PPP), the increased proportions of Embden-Meyerhof-Parnas pathway (EMP), tricarboxylic acid (TCA) cycle and cytochrome pathway (CCP) in total respiratory pathways. These findings further revealed that H2O2 could enhance respiration rate, and thus accelerate pulp breakdown occurrence and shorten the shelf life of longan fruit.

3.
PLoS Negl Trop Dis ; 13(10): e0007733, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31671094

RESUMO

Bats are reservoirs for several zoonotic pathogens, including filoviruses. Recent work highlights the diversity of bat borne filoviruses in Asia. High risk activities at the bat-human interface pose the threat of zoonotic virus transmission. We present evidence for prior exposure of bat harvesters and two resident fruit bat species to filovirus surface glycoproteins by screening sera in a multiplexed serological assay. Antibodies reactive to two antigenically distinct filoviruses were detected in human sera and to three individual filoviruses in bats in remote Northeast India. Sera obtained from Eonycteris spelaea bats showed similar patterns of cross-reactivity as human samples, suggesting them as the species responsible for the spillover. In contrast, sera from Rousettus leschenaultii bats reacted to two different virus glycoproteins. Our results indicate circulation of several filoviruses in bats and the possibility for filovirus transmission from bats to humans.

4.
Chemosphere ; 241: 125065, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31622886

RESUMO

Heavy metal-contaminated farmland, especially for cadmium (Cd), is being used for agricultural production in large scale due to the increasing food demand. Thus, minimizing the influx of Cd to the human food chain is urgently needed. Screening for stably low Cd and moderately high micronutrient wheat cultivars is one of the most feasible and effective approaches to ensure food safety and quality. Here, the Cd accumulation by 72 wheat cultivars was identified in field 1, and the stability of Cd accumulation in these cultivars was tested in fields 2 and 3. The effects of Cd on micronutrient (zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), and boron (B)) uptake in grains were also investigated. Nine of the 24 low-Cd wheat cultivars identified by screening showed stably low-Cd and moderately high micronutrient concentrations in grain. Nine cultivars exhibited unstable low-Cd accumulation characteristics, and another five cultivars contained significantly lower Zn concentrations in grain in at least two experimental fields. One low-Cd cultivar also had low Zn, Cu and Mn concentrations in grain. The accumulation of Cd in wheat grain had little effects on the uptake of Fe. Grain Cd concentration correlated positively with the dry weight of stem and root, and negatively with the spike length. There was no correlation between grain Cd concentration and wheat yield. The selected cultivars with stably low-Cd accumulation and moderately high micronutrient concentrations in grain are recommended for cultivation in slightly to moderately Cd-contaminated farmland to ensure food safety for the growing human population.

5.
J Immunol ; 203(10): 2712-2723, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31597705

RESUMO

The inflammasomes play critical roles in numerous pathological conditions largely through IL-1ß and/or IL-18. However, additional effectors have been implied from multiple studies. In this study, through two independent mass spectrometry-based secretome screening approaches, we identified galectin-3 as an effector protein of the NLRP3 inflammasome. Although the activation of AIM2 or NLRC4 inflammasome also led to galectin-3 secretion, only the NLRP3 inflammasome controlled the serum galectin-3 level under physiological condition. Mechanistically, active gasdermin D drove the nonexosomal secretion of galectin-3 through the plasma membrane pores. In vivo, high-fat diet-fed Nlrp3-/- mice exhibited decreased circulating galectin-3 compared with wild-type animals. Of note, the improved insulin sensitivity in such Nlrp3-/- mice was aggravated by infusion of recombinant galectin-3. Moreover, galectin-3 was essential for insulin resistance induction in mice harboring the hyperactive Nlrp3A350V allele. Thus, the inflammasome-galectin-3 axis has been demonstrated as a promising target to intervene inflammasome and/or galectin-3 related diseases.

6.
J Sep Sci ; 42(23): 3521-3527, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31560415

RESUMO

Cetyltrimethyl ammonium bromide-modified attapulgite was prepared and utilized as a novel sorbent in a simple solid-phase extraction method for the determination of vitamin A in blood serum. Several factors affecting extraction efficiency were systematically optimized, including the sampling solvent and its volume, as well as the elution solvent and its volume. Under the optimal solid-phase extraction conditions, the adsorption capacity of vitamin A was as high as 28 mg/g according to the Langmuir isotherm model. Based on the developed solid-phase extraction method, the level of vitamin A in 200 µL blood serum sample could be accurately determined by high-performance liquid chromatography. The recoveries of vitamin A spiked in 10% v/v methanol aqueous solutions were in the range of 86.9-92.8%, with the relative standard deviations not more than 8.1%. The method was applied to the determination of vitamin A in serum samples from 20 pregnant women. Compared with the previously reported solid-phase extraction methods for determination of vitamin A in serum, our developed cetyltrimethyl ammonium bromide-modified attapulgite-based solid-phase extraction method used lower serum volume, omitted extra steps (i.e. evaporation and re-dissolution), and eliminated internal standard. The results were promising for it to be used in routine monitoring during pregnancy.

7.
Chem Commun (Camb) ; 55(61): 8991-8994, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31290874

RESUMO

A para-N-phenyl-amino group significantly increases the fluorescence quantum yield of N-phenyl-4-aminostilbene by the "amino conjugation effect", but, in contrast, a para-amino group in the para-amino analogue (p-ABDI) of the green fluorescent protein (GFP) chromophore makes p-ABDI non-fluorescent because the coherent photo-induced intramolecular charge transfer reduces the barrier of the Z/E-photoisomerization.


Assuntos
Compostos de Benzil/química , Proteínas de Fluorescência Verde/química , Imidazolinas/química , Compostos de Benzil/efeitos da radiação , Teoria da Densidade Funcional , Fluorescência , Proteínas de Fluorescência Verde/efeitos da radiação , Imidazolinas/efeitos da radiação , Isomerismo , Modelos Químicos
8.
Food Chem ; 297: 124955, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253342

RESUMO

This study aimed to investigate the effect of hydrogen peroxide (H2O2) on membrane lipids metabolism and its relation to pulp breakdown development of longan fruit during postharvest storage. Compared to the control longans, H2O2-treated longans showed higher pulp breakdown index, cell membrane permeability, and activities of phospholipase D (PLD), lipase and lipoxygenase (LOX). Moreover, H2O2-treated longans maintained higher levels of pulp phosphatidic acid (PA) and saturated fatty acids (SFA). However, H2O2-treated longans exhibited lower levels of pulp phosphatidylcholine (PC), phosphatidylinositol (PI) and unsaturated fatty acids (USFA), lower index of unsaturated fatty acids (IUFA), and lower ratio of USFA to SFA (U/S). These findings demonstrated that H2O2 caused the increased activities of enzymes involving in membrane lipids degradation and the accelerated decompositions of membrane USFA and phospholipids in longan pulp, which eventually triggered the destruction of the pulp cell membrane structure and the development of pulp breakdown in longans during storage.


Assuntos
Enzimas/metabolismo , Frutas/química , Peróxido de Hidrogênio/farmacologia , Lipídeos de Membrana/metabolismo , Sapindaceae/química , Enzimas/química , Ácidos Graxos/análise , Ácidos Graxos/química , Armazenamento de Alimentos , Frutas/efeitos dos fármacos , Frutas/metabolismo , Peróxido de Hidrogênio/química , Lipase/química , Lipase/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipoxigenase/química , Lipoxigenase/metabolismo , Lipídeos de Membrana/química , Fosfolipase D/metabolismo , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Sapindaceae/efeitos dos fármacos , Sapindaceae/metabolismo
9.
Shock ; 2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-31135705

RESUMO

Sepsis is a major challenge in clinical practice and responsible for high mortality. Recent studies indicated that integrins participated in TLR-mediated innate immunity. In the present study, we investigated the mechanism of integrin ß3 and TLR4 signaling using a cecal ligation and puncture (CLP) induced sepsis and LPS-treated macrophage cell model. In a lethal CLP model, the survival rate of integrin ß3 mice was higher than that of wild type mice. The levels of ALT, AST, Cre, BUN and LDH in the serum and CD14 protein expression in the tissues were significantly decreased in integrin ß3 mice. A similar effect with regard to CD14 down-regulation was observed in septic TLR4 mice. In wild type macrophages, the inhibition of integrin ß3 by P11 or with a specific antibody, inhibited TNF-α and IL-6 release at the early time period of LPS stimulation. However, during the late periods of LPS stimulation this effect was not noted. CD14 expression levels had no change in such treatment. In contract, LPS-induced TNF-α and IL-6 release and LPS-induced CD14 expression were significantly decreased in integrin ß3macrophages. The inhibition of the TLR4 pathway by TAK-242, or in TLR4 mutant macrophages abolished LPS-induced CD14 expression. Integrin ß3 pathway activation by vitronectin exhibited no effect in CD14 expression. Furthermore, recombinant CD14 protein stimulation reversed integrin ß3 deficiency and caused lower TNF-α and IL-6 release. Moreover, the molecular interaction of TLR4 and integrin ß3 was significantly increased following LPS stimulation. In conclusion, integrin ß3 positively regulated TLR4-mediated inflammatory responses via CD14 expression in macrophages in septic condition. Specifically targeting integrin ß3/TLR4-CD14 signaling pathway may be a potential treatment strategy for polymicrobial sepsis.

10.
Carbohydr Polym ; 217: 126-134, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31079668

RESUMO

Longan pulp is an excellent source of polysaccharides and other nutrients that have many health benefits. However, longans is susceptible to pulp breakdown after harvest and loses its nutrition values. To solve this problem, this study aimed to study the effects of a novel chitosan, Kadozan, on pulp breakdown index, contents of pectin, cellulose and hemicelluloses, and activities of enzymes in longan pulp relating to disassembly of polysaccharides (XET, PE, PG, ß-Gal, and cellulase). The data illustrated that, compared to the control longans, chitosan-treated longans contained higher amounts of CWM, CSP, ISP, cellulose and hemicelluloses, but exhibited lower pulp breakdown index, lower activities of cell wall-disassembling enzymes, and contained lower WSP amount. These results suggested that Kadozan with a dilution of 1:500 (VKadozan: VKadozan + Water) could significantly decrease activities of disassembling-enzymes and depolymerization of polysaccharides in cell wall, and subsequently alleviate pulp breakdown and prolong storage-life of postharvest longans.


Assuntos
Parede Celular/efeitos dos fármacos , Quitosana/farmacologia , Inibidores Enzimáticos/farmacologia , Frutas/metabolismo , Polissacarídeos/metabolismo , Sapindaceae/metabolismo , Parede Celular/metabolismo , Celulose/metabolismo , Conservação de Alimentos/métodos , Qualidade dos Alimentos , Glicosídeo Hidrolases/antagonistas & inibidores , Hidrólise/efeitos dos fármacos , Pectinas/metabolismo
11.
Environ Toxicol ; 34(6): 760-767, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30884126

RESUMO

Oral Squamous Cell Carcinoma (OSSC) is a major life-threatening disease with high incidence in the Southeast Asian countries. Chronic exposure to arecoline causes genetic changes in the epithelial cells of the oral mucosa, induces proliferation through activation of the EGF receptor and promotes downstream COX-2 expression. Taiwanin C, a podophyllotoxin derived from Taiwania cryptomerioides Hayata is known to inhibit COX activity and to hinder PGE2 production in macrophages. In this study a tumor cell line T28 and a non-tumor cell line N28 derived from mice OSCC models were used to study the effect of Taiwanin C on PGE2 associated COX-2 expression and cell cycle regulators. Taiwanin C activated p21 protein expression, down-regulated cell cycle regulatory proteins, elevated apoptosis and down-regulated p-PI3K/p-Akt survival mechanism in T28 oral cancer cells. Our results therefore emphasize the therapeutic potential of Taiwanin C against arecoline-induced oral cancer.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma de Células Escamosas/patologia , Proliferação de Células/efeitos dos fármacos , Receptores ErbB/antagonistas & inibidores , Lactonas/farmacologia , Lignanas/farmacologia , Neoplasias Bucais/patologia , Fosfatidilinositol 3-Quinases/antagonistas & inibidores , 4-Nitroquinolina-1-Óxido/toxicidade , Animais , Arecolina/toxicidade , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/metabolismo , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos Endogâmicos C57BL , Neoplasias Bucais/induzido quimicamente , Neoplasias Bucais/metabolismo
12.
Mol Med Rep ; 19(5): 3604-3614, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30896817

RESUMO

An increasing number of microRNA (miRNA) have been demonstrated to serve as molecular biomarkers for tumor cell progression. miR­512­5p was revealed as oncogenic regulator in several types of cancer. However, whether and how miR­512­5p regulates non­small cell lung cancer (NSCLC) remains unclear. In the present study, the expression of miR­512­5p was detected in NSCLC tissues and cell lines. Then, the proliferation, migration, invasion and apoptosis in NSCLC A549 and H1299 cell lines were detected when miR­512­5p was overexpressed. Furthermore, the underlying mechanism was identified. The level of miR­512­5p was decreased in NSCLC tissues and in NSCLC cells compared with adjacent normal tissues and normal lung tissue cell lines. miR­512­5p mimics inhibited the cell proliferation, migration, invasion and induced apoptosis in A549 and H1299 cells. In addition, a luciferase reporter assay suggested that overexpression of miR­512­5p may decrease the expression of the E26 transformation specific­1 (ETS1) gene; it was subsequently verified that downregulation of the ETS1 gene inhibited cell proliferation and migration and induced cell apoptosis in A549 and H1299 cells, and ETS1 small interfering RNA in the presence of an miR­512­5p inhibitor reversed the effect. The data described in the present study suggest that miR­512­5p may be a tumor suppressor and a potential treatment target in NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , MicroRNAs/genética , Proteína Proto-Oncogênica c-ets-1/genética , Interferência de RNA , Regiões 3' não Traduzidas , Apoptose/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Técnicas de Silenciamento de Genes , Humanos
13.
Photodiagnosis Photodyn Ther ; 26: 65-72, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30831261

RESUMO

BACKGROUND: Increasing evidence has suggested that autophagy may play a resistant role during photodynamic therapy (PDT). The Wnt/ß-catenin pathway is tightly involved in cell proliferation and autophagy. In this study, we aimed to determine the influence of 5-Ethylamino-9-diethylaminobenzo[a]phenoselenazinium (EtNBSe) mediated PDT (EtNBSe-PDT) on autophagy, proliferation and Wnt/ß-catenin pathway in human NPC cell line (HNE-1 cells), and further explore the underlying crosstalk between them. METHODS: Cell viability and proliferation was evaluated by MTT assay. Autophagy and Wnt/ß-catenin signaling pathway was analyzed by western blotting and immunofluorescence. RESULTS: It was revealed that EtNBSe-PDT significantly impeded the viability and proliferation of HNE-1 cells. Meanwhile EtNBSe-PDT could notably induce autophagy in HNE-1 cells accompanied with the inhibition of Wnt/ß-catenin pathway. The Wnt/ß-catenin pathway activator Wnt agonist was found to partially counteract the inhibitory proliferation of HNE-1 cells and suppress the autophagy induced by EtNBSe-PDT. In addition, pretreatment with the autophagy inhibitor 3-methyladenine (3-MA) or Wnt agonist showed the potential in enhancing the cytotoxic effect of EtNBSe-PDT (cell survival from 50.71 ± 4.16% to 24.53 ± 4.27% and from 52.64 ± 3.54% to 35.74 ± 4.27% respectively). CONCLUSION: Taken together, this study demonstrated that EtNBSe-PDT suppressed viability and proliferation, and induced autophagy of HNE-1 cells via downregulating the Wnt/ß-catenin pathway. The autophagy further constituted the cytoprotective mechanisms involved in HNE-1 cells, which suggested that the combination of EtNBSe-PDT and autophagy inhibitors may be a promising strategy for the treatment of human NPC.

14.
Food Chem ; 275: 239-245, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30724192

RESUMO

This study aimed to investigate the effects of Lasiodiplodia theobromae (Pat.) Griff. & Maubl (L. theobromae) inoculation on the energy status and activity of adenosine triphosphatase (ATPase) during L. theobromae-induced disease development and pericarp browning of harvested 'Fuyan' longan (Dimocarpus longan Lour. cv. Fuyan) fruit. The results showed that, compared to the control longans, L. theobromae-inoculated longans displayed higher indices of fruit disease and pericarp browning, lower pericarp ATP and ADP contents, higher AMP content, lower level of energy charge, as well as lower activities of Ca2+-ATPase, Mg2+-ATPase and H+-ATPase in membranes of plasma, vacuole, and mitochondria. These results indicated that the infection of L. theobromae reduced energy status and ATPase activities, caused ions disorder, damaged the integrity and function of the cell and organelles including vacuole and mitochondria in pericarp of longan fruit, which contributed to L. theobromae-promoted disease development and pericarp browning of harvested longan fruit during storage.


Assuntos
Adenosina Trifosfatases/metabolismo , Ascomicetos/patogenicidade , Doenças das Plantas/microbiologia , Sapindaceae/metabolismo , Sapindaceae/microbiologia , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Metabolismo Energético , Frutas/metabolismo , Frutas/microbiologia , Mitocôndrias/metabolismo , Proteínas de Plantas/metabolismo , Vacúolos/metabolismo
15.
IEEE Trans Biomed Eng ; 66(9): 2481-2490, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30605090

RESUMO

We present novel voltage stimulation buffers with controlled output current, along with recording circuits featuring adjustable high-pass cut-off filtering to perform efficient stimulation while actively suppressing stimulation artifacts in high-density microelectrode arrays. Owing to the dense packing and close proximity of the electrodes in such systems, a stimulation through one electrode can cause large electrical artifacts on neighboring electrodes that easily saturate the corresponding recording amplifiers. To suppress such artifacts, the high-pass corner frequencies of all available 2048 recording channels can be raised from several Hz to several kHz by applying a "soft-reset" or pole-shifting technique. With the implemented artifact suppression technique, the saturation time of the recording circuits, connected to electrodes in immediate vicinity to the stimulation site, could be reduced to less than 150 µs. For the stimulation buffer, we developed a circuit, which can operate in two modes: either control of only the stimulation voltage or control of current and voltage during stimulation. The voltage-only controlled mode employs a local common-mode feedback operational transconductance amplifier with a near rail-to-rail input/output range, suitable for driving high-capacitive loads. The current/voltage controlled mode is based on a positive current conveyor generating adjustable output currents, whereas its upper and lower output voltages are limited by two feedback loops. The current/voltage controlled circuit can generate stimulation pulses up to 30 µA with less than ±0.1% linearity error in the low-current mode and up to 300 µA with less than ±0.2% linearity error in the high-current mode.

16.
Food Chem ; 270: 229-235, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30174039

RESUMO

This study aimed to investigate the effects of acidic electrolyzed oxidizing water (AEW) treatment on storability and metabolism of reactive oxygen species (ROS) in blueberries cv. 'Brightwell' during storage at 4 °C. Results showed that, compared with the control blueberries, AEW treated-blueberries exhibited lower incidence of fruit decay, higher rate of commercially acceptable fruit, higher fruit firmness and skin hardness, and higher anthocyanin and total phenolics contents, along with higher activities of SOD, CAT and APX, higher antioxidant activity, but lower generation rate of superoxide anion and cell membrane permeability. These results demonstrated that AEW treatment for enhancing storability of harvested blueberries during storage may be mediated by regulating ROS metabolism, manifested as AEW increasing ROS scavenging capacity and reducing ROS accumulation, and thereby maintained the structural integrity of cellular membrane, which indicated that AEW treatment was a facile postharvest method for extending the shelf life of harvested blueberries.


Assuntos
Mirtilos Azuis (Planta)/química , Armazenamento de Alimentos/métodos , Espécies Reativas de Oxigênio/metabolismo , Antocianinas , Antioxidantes , Frutas , Água
17.
Front Microbiol ; 9: 2466, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30386318

RESUMO

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.

18.
J Agric Food Chem ; 2018 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-30403851

RESUMO

This study investigated the changes in metabolisms of membrane lipids and phenolics caused by Phomopsis longanae Chi infection in association with pericarp browning and fruit disease occurrence of postharvest longans. Compared with the uninoculated-longans, the longans inoculated by P. longanae exhibited higher cellular membrane permeability; higher PLD, lipase, and LOX activities; and higher levels of saturated fatty acids (SFAs) and phosphatidic acid but lower levels of phosphatidylinositol, phosphatidylcholine, and unsaturated fatty acids (USFAs). Additionally, the longans inoculated by P. longanae showed higher activities of POD and PPO but a lower amount of total phenolics. These findings suggested that infection of P. longanae enhanced activities of PLD-, lipase-, and LOX- stimulated degradations of membrane lipids and USFAs, which destroyed the integrity of the cell membrane structure, resulting in enzymatic browning by contact of phenolics with POD and PPO, and resulting in reduction of resistance to pathogen infection and accordingly accelerated disease occurrence of postharvest longan fruit.

19.
Food Chem ; 266: 299-308, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30381189

RESUMO

This study aimed to investigate the effects of a novel chitosan formulation (Kadozan) treatment on disease development, response of disease resistance, metabolism of reactive oxygen species (ROS) in Peronophthora litchii-inoculated "Wuye" litchis. Compared with P. litchii-inoculated litchis, Kadozan-treated P. litchii-inoculated litchis exhibited lower fruit disease index, higher lignin content, higher activities of disease resistance-related enzymes (CHI, GLU and PAL), lower O2- generating rate and malondialdehyde content, higher activities of ROS scavenging enzymes (SOD, CAT and APX), higher contents of ascorbic acid and glutathione, and higher levels of reducing power and DPPH radical scavenging activity. These results suggest that Kadozan can be used to inhibit the growth of P. litchii in harvested litchis owning to the enhancement of disease resistance and ROS scavenging capacity, and decreases in O2- accumulation and membrane lipid peroxidation. Kadozan treatment can be used as a facile and novel method for suppressing postharvest pathogenic disease of litchis.

20.
Artigo em Inglês | MEDLINE | ID: mdl-30418922

RESUMO

A monolithic multi-functional CMOS microelectrode array system was developed that enables label-free electrochemical impedance spectroscopy of cells in-vitro at high spatiotemporal resolution. The electrode array includes 59,760 platinum microelectrodes, densely packed within a 4.5 mm×2.5 mm sensing region at a pitch of 13.5 µm. 32 on-chip lock-in amplifiers can be used to measure the impedance of any arbitrarily chosen subset of electrodes in the array. A sinusoidal voltage, generated by an on-chip waveform generator with a frequency range from 1 Hz to 1 MHz, was applied to the reference electrode. The sensing currents through the selected recording electrodes were amplified, demodulated, filtered and digitized to obtain the magnitude and phase information of the respective impedances. The circuitry consumes only 412 µW at 3.3 V supply voltage and occupies only 0.1 mm2, for each channel. The system also included 2048 extracellular action-potential recording channels on the same chip. Proof of concept measurements of electrical impedance imaging and electrophysiology recording of cardiac cells and brain slices are demonstrated in this paper. Optical and impedance images showed a strong correlation.

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