Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Antioxidants (Basel) ; 12(3)2023 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-36978810

RESUMEN

Alcohol has been demonstrated to disrupt intestinal barrier integrity. Some flavonoid compounds that exert antioxidant activity have a protective effect on intestinal barrier function. As an important medicinal and edible plant, sea buckthorn (Hippophae) seeds are rich in flavonoids, but their protective effect on the intestinal barrier has not been reported. In our research, 76 kinds of flavonoids were identified in Hippophae rhamnoides ssp. sinensis seed residue flavonoids (HRSF) by ultra-performance liquid chromatography-tandem mass spectrometry. Kaempferol-3-O-rutinoside, isorhamnetin-3-O-rutinoside, kaempferol-3-O-robinoside-7-O-rhamnoside, isorhamnetin-3-O-2G-rhamnosylrutinoside, quercetin-3-O-rutinoside, (-)-epigallocatechin, and B type of procyanidin were the most abundant substances, accounting for 15.276%, 15.128%, 18.328%, 10.904%, 4.596%, 5.082%, and 10.079% of all identified flavonoids, respectively. Meanwhile, pre-treatment with HRSF was able to prevent alcohol-induced disruption of intestinal barrier integrity through elevating the transepithelial monolayer resistance value, inhibiting the flux of fluorescein isothiocyanate-dextran, and upregulating the mRNA and protein level of TJs (occludin and ZO-1). Furthermore, it was also able to reverse alcohol-induced oxidative stress through suppressing the accumulation of reactive oxygen species and malondialdehyde, improving the glutathione level and superoxide dismutase activity. Finally, the results showed that HRSF pre-treatment effectively elevated the erythroid-related factor 2 mRNA and protein level compared with the alcohol-alone treatment group. Our research was the first to demonstrate that HRSF could prevent alcohol-induced intestinal barrier dysfunction through regulating the Nrf2-mediated pathway in order to attenuate oxidative stress and enhance TJ expression.

2.
Food Chem ; 404(Pt B): 134711, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36332579

RESUMEN

There is an increasing market share of dealcoholized wines due to rise in patronage by wine consumers. However, the aroma of such wines deteriorates the more the alcohol content is reduced. Improving the aroma with edible flowers may curb this problem. To improve the aroma of a dealcoholized Merlot red wine, extracts of peach, rose, and lily flowers (FEs) were added to develop three reconstituted dealcoholized wines (RDWS). RDWS were compared with the original wine and the dealcoholized wine (DW) based on chemical properties, aroma compounds, and sensory characteristics. The FEs had no effect on the chemical parameters of RDWS. The FEs improved the volatile composition of RDWS, especially ethyl octanoate, isoamyl octanoate, linalool, and geraniol. Sensory analysis showed that aroma intensity and fruity and floral notes improved in RDWS compared to DW. Among the FEs, rose was the best and can improve the aroma of dealcoholized Merlot red wine.


Asunto(s)
Compuestos Orgánicos Volátiles , Vino , Odorantes/análisis , Vino/análisis , Compuestos Orgánicos Volátiles/análisis , Frutas/química , Flores/química
3.
Sensors (Basel) ; 21(24)2021 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-34960275

RESUMEN

Nowadays, faces in videos can be easily replaced with the development of deep learning, and these manipulated videos are realistic and cannot be distinguished by human eyes. Some people maliciously use the technology to attack others, especially celebrities and politicians, causing destructive social impacts. Therefore, it is imperative to design an accurate method for detecting face manipulation. However, most of the existing methods adopt single convolutional neural network as the feature extraction module, causing the extracted features to be inconsistent with the human visual mechanism. Moreover, the rich details and semantic information cannot be reflected with single feature, limiting the detection performance. Therefore, this paper tackles the above problems by proposing a novel face manipulation detection method based on a supervised multi-feature fusion attention network (SMFAN). Specifically, the capsule network is used for face manipulation detection, and the SMFAN is added to the original capsule network to extract details of the fake face image. Further, the focal loss is used to realize hard example mining. Finally, the experimental results on the public dataset FaceForensics++ show that the proposed method has better performance.


Asunto(s)
Cabeza , Redes Neurales de la Computación , Humanos
4.
Molecules ; 23(8)2018 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-30072592

RESUMEN

The aim of this study is to develop and validate an improved analytical method for the simultaneous quantification of 20 types of mycotoxins in grapes and wines. In this research, the optimization of tandem mass spectrometer (MS/MS) parameter, ultra-high pressure liquid chromatography (UHPLC) separation, and QuEChERS procedure, which includes wine/water ratio, the amount and type of salt, clean-up sorbent, were performed, and the whole separation of mycotoxins was accomplished within 7 min analyzing time. Under optimum conditions, recoveries ranged from 85.6% to 117.8%, while relative standard deviation (RSD) remained between 6.0% and 17.5%. The limit of detection (LOD, 0.06⁻10 µg/L) and the limit of quantification (LOQ, 0.18⁻30 µg/L) were lower than those permitted by legislation in food matrices, which demonstrated the high sensitivity and applicability of this efficient method. Finally, 36 grapes and 42 wine samples from the Hexi Corridor region were analyzed. Penicillic acid (PCA), mycophenolic acid (MPA), cyclopiazonic acid (CPA), fumonisin B1 (FB1) and zearalenone (ZEN) were detected in a small number of grape samples with lower concentrations between 0.10 µg/L and 81.26 µg/L. Meanwhile, ochratoxin A (OTA), aflatoxin B2 (AFB2), MPA, CPA, and ZEN were detected in some wine counterparts with concentrations ranged from 0.10 µg/L to 4.62 µg/L. However, the concentrations of the detected mycotoxins were much lower than the maximum legal limits set of other products.


Asunto(s)
Micotoxinas/análisis , Espectrometría de Masas en Tándem/métodos , Vitis/química , Vino/análisis , Calibración , China , Cromatografía Líquida de Alta Presión , Límite de Detección , Modelos Lineales , Estadística como Asunto , Agua/química
5.
Exp Ther Med ; 15(4): 3917-3923, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29563987

RESUMEN

As a major cancer type in females, cervical cancer has been explored in depth by researchers. HeLa is a cervical cancer cell line. Isorhamnetin is an O-methylated flavonol that is primarily extracted from sea buckthorn. In the present study, the anti-proliferative effect of isorhamnetin on HeLa cells was evaluated using a Trypan blue dye exclusion assay. Isorhamnetin inhibited the cell proliferation in a time- and dose-dependent manner. Flow cytometric analysis of the cell cycle distribution revealed that isorhamnetin inhibited the cell cycle progression of HeLa by causing G2/M phase arrest and decreasing the proportion of cells in G1 phase. In addition, western blot analysis was performed to evaluate the presence of certain cell cycle-associated proteins. It was demonstrated that isorhamnetin inhibited the protein expression of cyclin B1, cell division cycle 25C (Cdc25C) and Cdc2, but enhanced checkpoint kinase 2 (Chk2), Cdc25C and Cdc2 phosphorylation. In addition, tubulin depolymerization participated in the isorhamnetin-induced cell cycle arrest in G2/M phase. In conclusion, the present results indicated that the anti-proliferative action of isorhamnetin is associated with arrest of the cell cycle in G2/M phase, which is a consequence of activation of the ataxia telangiectasia mutated Chk2 pathway and disruption of microtubule function.

6.
Food Res Int ; 102: 468-477, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-29195974

RESUMEN

In the recent research, the copigmentations of malvidin-3-O-glucoside with eight types of phenolic copigments have been investigated. The influence of the pigment/copigment molar ratio, the reaction temperature, the pH and the ethanol content of solutions has been examined. The results showed that the copigmentation effect was dependent on not only the particular structures of the phenolic compounds but also the factors of the reaction systems. The increase of the copigment concentration can strengthen the copigmentation effect, improve the solution color, and enhance the red-purple features. Different temperatures had different influences on the copigmentation reactions. The destruction of the copigmentation complexes can result in the hypsochromic shift of the reaction solution when the temperature was higher than 20°C. The bathochromic shift of the solution gradually progressed with the increase of the pH value. A significant copigmentation feature was spotted when pH reached 3.0, which demonstrates obvious red-purple characterization. The addition of the ethanol weakened the copigmentation effect. According to measurement through color analysis, it was found that the color differences caused by ethanol in red wine were typically attributed to quantitative changes. Remarkably, all of the above delicate color deviations caused by the structural or environmental factors can be precisely and conveniently depicted via the CIELAB space analysis.


Asunto(s)
Antocianinas/análisis , Color , Colorimetría/métodos , Etanol/análisis , Glucósidos/análisis , Fenoles/análisis , Temperatura , Vino/análisis , Concentración de Iones de Hidrógeno , Estructura Molecular , Relación Estructura-Actividad
7.
Food Sci Nutr ; 3(5): 453-65, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26405531

RESUMEN

For the purpose of SO2 reduction and stabilizing ice wine, a new antibacterial technique was developed and verified in order to reduce the content of sulfur dioxide (SO2) and simultaneously maintain protein stability during ice wine aging process. Hazardous bacterial strain (lactic acid bacteria, LAB) and protein stability of Italian Riesling ice wine were evaluated in terms of different amounts of lysozyme, SO2, polyphenols, and wine pH by single-factor experiments. Subsequently, a quadratic rotation-orthogonal composite design with four variables was conducted to establish the multiple linear regression model that demonstrated the influence of different treatments on synthesis score between LAB inhibition and protein stability of ice wine. The results showed that, synthesis score can be influenced by lysozyme and SO2 concentrations on an extremely significant level (P < 0.01). Furthermore, the lysozyme-combined antibacterial system, which is specially designed for ice wine aging, was optimized step by step by response surface methodology and ridge analysis. As a result, the optimal proportion should be control in ice wine as follows: 179.31 mg L(-1) lysozyme, 177.14 mg L(-1) SO2, 0.60 g L(-1) polyphenols, and 4.01 ice wine pH. Based on this system, the normalized synthesis score between LAB inhibition and protein stability can reach the highest point 0.920. Finally, by the experiments of verification and comparison, it was indicated that lysozyme-combined antibacterial system, which was a practical and prospective method to reduce SO2 concentration and effectively prevent contamination from hazardous LAB, can be used to stabilize ice wine during aging process.

8.
J Nanosci Nanotechnol ; 15(2): 1331-7, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26353651

RESUMEN

We demonstrate the fabrication of three dimensional hierarchical ZnO/Si nanowire core-shell structure, which is used as a high surface area photoelectrode in photoelectrochemical cells for solar water splitting. This structure is fabricated via a two-step solution process: fabricating vertical aligned silicon nanowires via metal assisted etching method and then growing ZnO nanowires on the silicon nanowires via hydrothermal method. Transmission electron microscopy, scanning electron microscopy, spectrometer and X-ray diffractmeter are employed to characterize the hierarchical structure. The surface area of the hierarchical structure increases significantly compared to the simplex nanowire structure, which can substantially promote the photoelectrochemical reactions. The core-shell characteristic is beneficial to the charge carrier separation and the silicon nanowire backbones can work as the charge transfer channels, which contribute to the efficiency improvement. The experimental results indicate that the photocurrent density and the maximum conversion efficiency of the hierarchical structure photoelectrode have increased obviously, confirming that this hierarchical structure is more suitable for the application of photoelectrode than the ZnO nanowires/planar silicon structure.

9.
ACS Nano ; 8(7): 7163-9, 2014 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-24941287

RESUMEN

We report the fabrication of quantum dot-sensitized hierarchical structure and the application of the structure as a photoanode for photoelectrochemical water splitting. The structure is synthesized by hydrothermally growing ZnO nanowires on silicon microwires grown with the vapor-liquid-solid method. Then the hierarchical structure is further sensitized with CdS and CdSe quantum dots and modified with IrOx quantum dots. As a result, the silicon microwires, ZnO nanowires, and the quantum dot/ZnO core/shell structure form a multiple-level hierarchical heterostructure, which is remarkably beneficial for light absorption and charge carrier separation. Our experimental results reveal that the photocurrent density of our multiple-level hierarchical structure achieves a surprising 171 times enhancement compared to that from simple ZnO nanowires on a planar substrate. In addition, the photoanode shows high stability during the water-splitting experiment. These results prove that the quantum dot-sensitized hierarchical structure is an ideal candidate for a photoanode in solar water splitting applications. Importantly, the modular design approach we take to produce the photoanode allows for the integration of future discoveries for further improvement of its performance.

10.
Nanoscale Res Lett ; 8(1): 462, 2013 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-24191909

RESUMEN

In this work, we investigate the controlled fabrication of Sn-doped TiO2 nanorods (Sn/TiO2 NRs) for photoelectrochemical water splitting. Sn is incorporated into the rutile TiO2 nanorods with Sn/Ti molar ratios ranging from 0% to 3% by a simple solvothermal synthesis method. The obtained Sn/TiO2 NRs are single crystalline with a rutile structure. The concentration of Sn in the final nanorods can be well controlled by adjusting the molar ratio of the precursors. Photoelectrochemical experiments are conducted to explore the photocatalytic activity of Sn/TiO2 NRs with different doping levels. Under the illumination of solar simulator with the light intensity of 100 mW/cm2, our measurements reveal that the photocurrent increases with increasing doping level and reaches the maximum value of 1.01 mA/cm2 at -0.4 V versus Ag/AgCl, which corresponds to up to about 50% enhancement compared with the pristine TiO2 NRs. The Mott-Schottky plots indicate that incorporation of Sn into TiO2 nanorod can significantly increase the charge carrier density, leading to enhanced conductivity of the nanorod. Furthermore, we demonstrate that Sn/TiO2 NRs can be a promising candidate for photoanode in photoelectrochemical water splitting because of their excellent chemical stability.

11.
J Nanosci Nanotechnol ; 13(8): 5708-14, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23882822

RESUMEN

We investigated the controlled fabrication of uniform vertical aligned silicon nanowires with desired length, diameter and location by combining nanosphere lithograph and metal assisted chemical etching techniques. The close-packed polystyrene nanospheres array was obtained by self-assemble technique, followed by reactive ion etching to acquire a non-close-packed monolayer template. Subsequently, the template was used to create a metal film with nanoholes array, which enable the controlled fabrication of ordered silicon nanowires via metal assisted chemical etching technique. By adjusting the monolayer of polystyrene nanospheres and the conditions for the metal assisted chemical etching, we obtained uniform distributed silicon nanowires with desired morphology. The aspect ratio of the silicon nanowires can reach to about 86:1. Furthermore, we have obtained the double-layer silicon nanowires by slight modifying the process. The influences of various conditions during etching were also discussed for improving the controlled fabrication.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...