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关键词： active films   arthrospira platensis polysaccharide   chitosan   food packaging  

摘要： Active films from chitosan incorporated with Arthrospira platensis polysaccharide (APP) of various ratios (0.0%, 0.5%, and 1.0%, w/v) were developed by solution casting. The effect of APP on the structural, physicochemical, mechanical, antimicrobial, and antioxidant properties of the chitosan-APP films (CA-film) was investigated. Fourier transform infrared spectra (FTIR) confirmed successful incorporation of chitosan and APP. The compact structure of the films was observed clearly in scanning electron microscopy (SEM) and atomic force microscopy (AFM) images. X-ray diffraction (XRD) patterns suggest the semi-crystalline structure was increased upon addition of APP. The composite films showed an improved water resistance and vapor barrier properties, and reduced by at least 27.4% and 32.1% in swelling degree (S-d) and water vapor permeability (WVP) compared with chitosan film (C-film), respectively. However, the transparency decreased slightly, which may be due to the shrinkage of the spacing of the polymer interchain. The composite films also displayed enhanced the mechanical properties. The antimicrobial activity of the CA-film showed an increase of at least of 0.41-fold in inhibition zone diameter for E. coli. At a concentration of 1.2 mg/mL, the antioxidant activity of CA-film was enhanced by more than threefold compared with C-film. Therefore, CA-films have good potential as sources of active packaging material for the food industry.

关键词： Calcium hydroxide   EDX   Raman   SEM   Spectroscopy   XRD  

摘要： To investigate intrinsic physicochemical properties and interactions of three different calcium hydroxide-based medications via means of different analytical methods. Two-commercial premixed medications: TempCanal(TCmx) and ProCalR(PCmx) and powder-form ProCal(PCpw) with glycerin were used. Vibrational modes were analyzed using Raman spectroscopy. Spectral mapping of samples was carried out using characteristic vibrational modes of calcium hydroxide and barium sulfate. Crystalline and amorphous phases were studied with X-rays powder diffraction analysis. Topographic features were examined by scanning electron microscope examination and quantitative analysis was determined using energy-dispersive X-ray spectroscopy analysis. Strong OH stretch of in Raman spectra were observed at 3,697 and 3,615 cm(-1)for TCmx and reference, respectively. However, OH mode was not observed for PCmx and PCpw. Moreover, some peaks in the fingerprint areas of TCmx and PCpw overlapped with each other. The characteristic vibration bands of barium sulfate and calcium hydroxide were observed in all samples, and no new peak was observed in the Raman spectra of samples. Calcium hydroxide-based medications were seen as differed in their chemical composition. No new crystalline or amorphous phase peak was observed. Only calcium hydroxide and barium sulfate were matched in X-rays powder-diffraction analysis. Energy-dispersive X-ray spectroscopy analysis showed that amount of Ba and S elements in the PCpw were lower than TCmx and PCmx whereas, for Ca in the PCpw was higher than TCmx and PCmx. The present study revealed the structural difference among different forms of calcium hydroxide-based medications. The vehicle and substrates of the tested medications altered the physicochemical properties of the compound via electrostatic interactions.

关键词： Synthesis   Rod-coil   polymers   Liposomes   Physico-chemical properties   Diseases  

摘要： This work describes the synthesis of the new supramolecular rod-coil-rod polymer, designated as cholesterol-PEO1000-Iryptophan (Chl-PEO-Trp), as well as its effects on the physico-chemical properties of phosphatidyl-choline (PC)-based liposomes. The molecular interactions between the Chl-PEO-Trp and PC were characterized by HATR-FTIR, DSC, NMR, DLS and zeta (zeta) potential techniques. The Chl-PEO-Trp polymer yield was 75 %. FTIR and DSC data showed that the motion of almost all PC groups was restricted by the polymer, and it promoted a decrease of the trans-gauche isomerization of the PC methylene, restricting the mobility of the hydrophobic region of the liposomes. NMR analyses indicated a Chl-PEO-Trp-induced restriction in the rotation of the PC phosphorus and a discreet increase of the hydrogen mobility of the choline. Despite this increase in the rotation of the choline, DLS and zeta-potential analyses suggested a reorientation of the choline group toward the system surface, which contributed, along with the other physico-chemical effects, to a globally packed membrane arrangement and reduced liposome size. Data described in this work were correlated to possible applications of the Chl-PEO-Trp in its free or PC liposome-loaded forms in the diagnosis and therapy of cancer, SARS caused by coronaviruses, and central nervous system-related diseases.

关键词： cassava starches   natural pigments   potato starches   starch nanoparticles  

摘要： This study aims to develop and characterize modified starch particles containing anthocyanins (ACNs) from jambolan (Syzygium cumini) fruit, produced by an anti-solvent precipitation method. Trapping efficiency, particle size distribution, surface charge, crystalline structure, chemical bonds, thermal properties, moisture content, water activity, color, and desorption experiments are carried out in modified cassava starch (MCS) and modified potato starch (MPS), both containing ACNs. Physicochemical properties of MCS and MPS both containing ACN (MCS-ACN and MPS-ACN) are compared using native cassava and potato starches, as well as modified cassava and potato starches without ACNs. ACNs are trapped into the modified starches and the trapping efficiency value oscillates between 9.89% and 12.37%. The resulting MCS-ACN and MPS-ACN- powders display bimodal distributions with particle size lower than 900 nm and amorphous structure. Furthermore, the MCS-ACN and MPS-ACN powders show red color typical of ACNs and they are completely soluble in water and acidified water solutions at room temperature. This research reports for the first-time, information regarding the stabilization of ACNs using modified starch particles.

关键词： Alqueva reservoir   climate variability   land cover   land uses   water-sediment dynamics  

摘要： Nowadays, the Mediterranean freshwater systems face the threat of water scarcity, along with multiple other stressors (e.g., organic and inorganic contamination, geomorphological alterations, invasive species), leading to the impairment of their ecosystem services. All these stressors have been speeding up, due to climate variability and land cover/land use changes, turning them into a big challenge for the water management plans. The present study analyses the physicochemical and phytoplankton biomass (chlorophyll-a) dynamics of a large reservoir, in the Mediterranean region (Alqueva reservoir, Southern Portugal), under diverse meteorological conditions and land cover/land use real scenarios (2017 and 2018). The most important stressors were identified and the necessary tools and information for a more effective management plan were provided. Changes in these parameters were further related to the observed variations in the meteorological conditions and in the land cover/land use. The increase in nutrients and ions in the water column, and of potentially toxic metals in the sediment, were more obvious in periods of severe drought. Further, the enhancement of nutrients concentrations, potentially caused by the intensification of agricultural activities, may indicate an increased risk of water eutrophication. The results highlight that a holistic approach is essential for a better water resources management strategy.

关键词： Magnetic graphene oxide   Biomedical applications   Toxicity   Biosensors   Cancer therapy  

摘要： Magnetic graphene oxide, a compound of magnetic nanoparticles and graphene oxide, possesses distinct physical and chemical characteristics, including nano size, a large specific surface area, paramagnetic and biocompatible properties, making it a promising biomaterial in the field of biomedicine. In particular, its excellent characteristics, including the integration of specific photothermal properties, magnetic thermal properties, paramagnetism, active chemical bonds, hydrophilicity, and low cytotoxicity, have been applied to remarkable bio-applications in bioimaging, biosensors, biochemical extraction and separation, stem cell regulation and the induction of differentiation, targeted drug delivery, and cancer therapy. In this review, we concentrate on the approaches of preparation, fundamental structures, biocompatibility, and the biomedical applications of magnetic graphene oxide composites. (c) 2021 Elsevier B.V. All rights reserved.

关键词： Breast implant   BellaGel   Physicochemical property   Retrospective study  

摘要： This study aimed to assess the effectiveness and safety of BellaGel implants after implantation in Asian women and inform surgeons of another option for use in breast augmentation and reconstruction. This study was conducted in eight hospitals from November 27, 2015 to April 30, 2018. All patients underwent augmentation mammoplasty or implant-based breast reconstruction with BellaGel implants. Complication rates were compared between groups, and the cumulative hazard function was compared using the Kaplan-Meier survival analysis. Implants were grouped by surface type, and the cumulative hazard functions of total complication cases were compared. The biomechanical properties of the BellaGel implant and other company representative implants were tested using a mechanical testing machine, and surface topography was analyzed using a 3D laser scanning confocal microscope. There was a significant difference in the incidence of complications between the reconstruction (17.1%) and augmentation (4.7%) groups, but no significant difference in the complication rates of each group. There was no difference in the reoperation or revision rates between the groups. The log rank test showed a statistically significant difference in cumulative hazard function between the groups. Among the three types of implants (smooth, textured, and microtextured), the microtextured type had the lowest complication rate. The BellaGel microtexture implant had the highest maximal tensile load and displacement value. The BellaGel and Silksurface implants had the highest stored energy, although there was no significant difference. BellaGel implants can serve as a criterion for the selection of safe and effective implants among currently available implants. (C) 2020 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

关键词： ingredient functions   molecular structure   nutritional quality   plant‐   based protein   ultrasonic‐   assisted extraction (UAE)  

摘要： Ultrasonication is a green technology that has recently received an enormous research attention for extraction of plant-based proteins and tailoring the functionalities of these ingredients. Ultrasonication is generally used as a pretreatment method in the conventional protein solubilization protocols because it can break the cell matrix to improve the extractability. The rate of protein extraction and increase in the extraction yields depend on operating conditions such as sonic energy density, time of sonication, the substrate to slurry ratio, agitation, and so on. Ultrasonication is also applied to modify the physical, structural, and functional properties of protein-based ingredients, besides simultaneous extraction and modifications. Significant changes that occur in protein physical properties due to sonication include size reduction, rheology, electrical conductivity, and zeta (zeta) potential. These changes are due to cavitation-induced shear leading to changes in secondary and tertiary structures, including protein aggregation and cross-linking due to oxidation. Physical and structural changes affect the resulting ingredient functionality and nutritional quality of protein. Changes in the functional properties, especially hydrophobicity, solubility, emulsion, and foaming, depend on the extent of ultrasound energy applied to the protein. This study aims to review major ultrasound process parameters and conditions for extraction and modification of plant proteins and their impact on protein structural changes and resulting physicochemical, functional, and nutritional properties.

摘要： Analysis of the development of deformations under pulsed loading has shown the decisive role of powerful ultrasonic vibrations of a sample in the standing wave mode. The effect of mass transfer of atoms and ultrafine particles of the hardening phase from the matrix material to the spall damage zone on the microstructure of deformation bands is determined. Rapid cooling of the metal inside the localization bands, the size of which does not exceed several tens of microns, indicates that changes in the phase composition are caused by cold deformation.

关键词： Magnesium-aluminum-phyllosilicate   Biochar   Competitive adsorption   Low-cost   Composite adsorbent  

摘要： Biomass-derived carbon-attapulgite adsorbent was developed for organic pollutants removal. All the batch assays were performed to evaluate the effects of organic components, contact time, and initial concentration of organic pollutants on the adsorption performance of the as-prepared adsorbent. The samples were characterized via Brunauer-Emmett-Teller (BET), Fourier transform infrared (FTIR), X-ray diffractometer (XRD), and scanning electron microscopy (SEM). The results demonstrated that the acid-treated carbon-attapulgite adsorbent (H-ATP/BC) showed a large specific surface area (237 m(2) g(-1)) and possessed abundant oxygen-containing functional groups and silicon-oxygen bonds (i.e., O-Si-O and O-Si), which provided more active sites and conduced to the adhesive of organic pollutants. Both physical adsorption and chemical adsorption were involved in the adsorption process, and competitive adsorption occurred when two or more target pollutants coexist. Especially, phenol and/or aniline with an aromatic ring were much more likely to adhere to the H-ATP/BC surface than pyridine, and the selectivity order of H-ATP/BC for these pollutants was phenol > aniline > pyridine. From the model fitting, it was observed that the adsorption data could be described well by a pseudo-second-order model and Freundlich isotherms. The theoretical maximum phenol, aniline, and pyridine adsorption capacities of the H-ATP/BC were 14.31 mg g(-1), 15.21 mg g(-1), and 20.74 mg g(-1), respectively. Comparison among the commercial adsorbents price also illustrated that H-ATP/BC could be a promising material for efficient treatment of organic pollutants.