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1.
Int J Biol Macromol ; 253(Pt 6): 127407, 2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-37832613

RESUMEN

Epoxidized soybean oil (ESO) was used as a compatibilizer and blended with polylactic acid (PLA) and polypropylene carbonate (PPC) resin to prepare a series of PLA/PPC/ESO blends with varying compositions. The influence of the variation in the amount of ESO added to the blend system on the thermal properties, optical properties, rheological properties, mechanical properties, and microscopic morphology of the blends was studied. The research indicates that ESO can react with PLA and PPC to form a chemical bond interface, which improves the compatibility of PLA and PPC to a certain extent. With the increase in the amount of ESO added to the blend (1- 5 phr), the complete decomposition temperature, storage modulus, loss modulus, complex viscosity, notched impact strength, and elongation at break of the blend all show a trend of continuous increase. At the same time, the melt flow rate, light transmittance, and tensile strength of the blend do not show significant fluctuations. When the amount of ESO in the system is 5 phr, compared with the PLA/PPC blend, the notched impact strength and elongation at break of the PLA/PPC/ESO blend increase from 4270.3 J/m2, 43.89 % to 8560.4 J/m2, 211.28 %, respectively, and its tensile strength and transmittance still remain around 63 MPa, 92 %. This improves the toughness of the blend while maintaining its rigidity, demonstrating excellent mechanical and optical properties. At this time, the microscopic morphology of the fracture surface of the impact sample also shows obvious characteristics of tough fracture. However, when the amount of ESO added to the blend is excessive (6 phr), the compatibility of the blending system decreases, which will degrade the performance of the blending material and ultimately destroy the phase morphology of the blend and reduce its mechanical properties.


Asunto(s)
Poliésteres , Aceite de Soja , Poliésteres/química , Polipropilenos/química
2.
Food Chem ; 344: 128644, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33246682

RESUMEN

This work focuses on the synthesis of novel tannin-functionalized polypropylene copolymers that are designed to inhibit the oxidation of vegetable oils for potential use as packaging materials. An empty glass Petri dish (control), a chlorinated polypropylene-coated glass Petri dish (control) and a series of the tannin-functionalized polypropylene coated glass Petri dishes overlaid with linseed oil were exposed to air and additional white light. Oligomerization of the oxidized linseed oil was assessed by measuring the flow properties of the exposed oil using a viscometer. The antioxidant effect of the tannic acid grafted polypropylene copolymers (PP-Tann) retarded oligomerization of the linseed oil. The molar mass of the linoleic acid overlaid onto the PP-Tann films was the lowest among the tested samples after each time period indicating that tannin-grafted polypropylene may be a promising packaging material for vegetable oils.


Asunto(s)
Antioxidantes/química , Embalaje de Alimentos , Polipropilenos/química , Polipropilenos/síntesis química , Taninos/química , Técnicas de Química Sintética , Oxidación-Reducción , Aceites de Plantas
3.
ACS Appl Mater Interfaces ; 12(41): 46667-46677, 2020 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-32955861

RESUMEN

Active packaging materials, biodegradable and from renewable resources, are the most promising substitutes of nonbiodegradable, petroleum-based plastics, toward green and sustainable packaging solutions. In this study, an innovative bioplastic system, composed of carbon dioxide-derived poly(propylene carbonate) (PPC) and nature-originated cellulose acetate (CA), was developed. The extract from oregano waste was incorporated into the bioplastics as a low-cost and effective antioxidant resource. Thin, freestanding, and flexible PPC.CA bioplastic films were obtained by a simple, easily scalable solvent casting technique. The pristine films, without the oregano extract, featured good transparency and high water vapor barrier ability, along with suitable mechanical and thermal properties that are comparable to commercial plastics used for packaging. Interestingly, the incorporation of oregano waste extract added to the bioplastics high UV protection and high antioxidant activity, suitable features for active food packaging applications, without compromising the intriguing properties of the pristine films. The biocomposite films were not only biocompatible but also started biodegrading after just 1 week in seawater. The reported biocomposites are foreseen as promising candidates for several packaging applications, but in particular for sustainable active food packaging.


Asunto(s)
Materiales Biocompatibles/química , Dióxido de Carbono/química , Embalaje de Alimentos , Origanum/química , Plásticos/química , Polipropilenos/química , Celulosa/análogos & derivados , Celulosa/química , Residuos Industriales/análisis , Estructura Molecular , Tamaño de la Partícula , Extractos Vegetales/química , Propiedades de Superficie
4.
J Pharmacol Toxicol Methods ; 105: 106884, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32565325

RESUMEN

INTRODUCTION: Screening compounds for activity on the hERG channel using patch clamp is a crucial part of safety testing. Automated patch clamp (APC) is becoming widely accepted as an alternative to manual patch clamp in order to increase throughput whilst maintaining data quality. In order to standardize APC experiments, we have investigated the effects on IC50 values under different conditions using several devices across multiple sites. METHODS: APC instruments SyncroPatch 384i, SyncroPatch 384PE and Patchliner, were used to record hERG expressed in HEK or CHO cells. Up to 27 CiPA compounds were used to investigate effects of voltage protocol, incubation time, labware and time between compound preparation and experiment on IC50 values. RESULTS: All IC50 values of 21 compounds recorded on the SyncroPatch 384PE correlated well with IC50 values from the literature (Kramer et al., 2013) regardless of voltage protocol or labware, when compounds were used immediately after preparation, but potency of astemizole decreased if prepared in Teflon or polypropylene (PP) compound plates 2-3 h prior to experiments. Slow acting compounds such as dofetilide, astemizole, and terfenadine required extended incubation times of at least 6 min to reach steady state and therefore, stable IC50 values. DISCUSSION: Assessing the influence of different experimental conditions on hERG assay reliability, we conclude that either the step-ramp protocol recommended by CiPA or a standard 2-s step-pulse protocol can be used to record hERG; a minimum incubation time of 5 min should be used and although glass, Teflon, PP or polystyrene (PS) compound plates can be used for experiments, caution should be taken if using Teflon, PS or PP vessels as some adsorption can occur if experiments are not performed immediately after preparation. Our recommendations are not limited to the APC devices described in this report, but could also be extended to other APC devices.


Asunto(s)
Arritmias Cardíacas/tratamiento farmacológico , Benchmarking/métodos , Fármacos Cardiovasculares/farmacología , Descubrimiento de Drogas/métodos , Corazón/efectos de los fármacos , Técnicas de Placa-Clamp/métodos , Animales , Arritmias Cardíacas/metabolismo , Astemizol/farmacología , Células CHO , Calibración , Fármacos Cardiovasculares/química , Línea Celular , Cricetulus , Evaluación Preclínica de Medicamentos/métodos , Canal de Potasio ERG1/metabolismo , Células HEK293 , Humanos , Fenetilaminas/farmacología , Polipropilenos/química , Politetrafluoroetileno/química , Estándares de Referencia , Reproducibilidad de los Resultados , Sulfonamidas/farmacología , Terfenadina/farmacología
5.
ACS Appl Mater Interfaces ; 12(23): 26509-26514, 2020 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-32408733

RESUMEN

The joint membrane of the American lobster shows an excellent combination of high strength, toughness, and defect tolerance due to the periodic helicoidal stacking of the fiber layers that are connected by a weak continuous matrix. Inspired by the joint membrane of American lobsters, we simply use nonwoven fabrics and silicon rubber to fabricate a multilayer soft composite with the helicoidal stacking and controllable matrix. The influences of stacking structure, matrix strength, fabrics strength, and notch size on the fracture behavior of the soft composite during the tensile process are systematically analyzed by both experimental tests and finite element analysis (FEA). We find that similar to the joint membrane, the soft composite demonstrates a gradual failure process and a linear relationship between tensile strength/toughness and notch size. Such phenomena demonstrate the strong defect-tolerant ability, thereby imparting the soft composite with both high strength and toughness. The defect-tolerant ability is closely related to the helicoidal stacking and weak matrix between the fabrics layers, which induce crack deflection and inhibit the propagation of cracks across the sample.


Asunto(s)
Materiales Biomiméticos/química , Elastómeros de Silicona/química , Textiles , Animales , Análisis de Elementos Finitos , Ensayo de Materiales , Nephropidae , Nylons/química , Polipropilenos/química , Estrés Mecánico , Resistencia a la Tracción
6.
Biomolecules ; 10(6)2020 05 27.
Artículo en Inglés | MEDLINE | ID: mdl-32471275

RESUMEN

Hemp core is a lignocellulosic residue in the production chain of hemp strands. Huge amounts of hemp core are gathered annually in Europe (43,000 tons) with no major application end. Such lignocellulosic wastes have potential as filling or reinforcing material to replace synthetic fibers and wood fibers in polymer composites. In this study, hemp core biomass was treated under different NaOH concentrations and then defibrated by means of Sprout Waldron equipment to obtain single fibers. Polypropylene matrix was reinforced up to 50 wt.% and the resulting hemp core fibers and the flexural properties were investigated. The results show that the flexural strength of composites increased with the intensity of NaOH treatment. The effect of NaOH was attributed to the removal of extractives and lignin in the fiber cell wall leading to improved interfacial adhesion characteristics. Besides, a methodology was established for the estimation of the intrinsic flexural strength of hemp core fibers. The intrinsic flexural strength of hemp core fibers was calculated to be 940 MPa for fibers treated at 10 wt.% of NaOH. In addition, a relationship between the lignin content and the intrinsic strength of the fibers was established.


Asunto(s)
Cannabis/efectos de los fármacos , Resistencia Flexional/efectos de los fármacos , Polipropilenos/química , Hidróxido de Sodio/farmacología , Biomasa , Cannabis/química , Ensayo de Materiales , Tallos de la Planta/química , Tallos de la Planta/efectos de los fármacos
7.
Food Chem ; 321: 126720, 2020 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-32276149

RESUMEN

Migration of N,N-Bis(2-hydroxyethyl) alkyl(C8-C18)amines from five different polypropylene capsules to Tenax® and coffee powder have been studied. A single step extraction-cleanup procedure using salting out liquid-liquid extraction (SALLE) method followed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was applied. The critical parameters on the SALLE procedure such as extracting solvent, extracting volume, sample pH, salt and its concentration were optimized. The recovery values were in the range of 87.5%-106.5%. The %RSD were lower than 3.7%. The limit of detection was improved from 2.3 ng/g in Tenax® to 0.8 ng/g in coffee. The results indicated that the analyzed compounds have the potential to migrate from the polypropylene capsule containers to the coffee. In most of the cases, the migrated values were higher in Tenax® than in coffee in a range between 1.8 and 61%. One sample did not comply with the specific migration limit established by the European Commission.


Asunto(s)
Cápsulas/química , Café/química , Embalaje de Alimentos , Extracción Líquido-Líquido/métodos , Polímeros/química , Polipropilenos/química , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Liquida , Análisis de los Alimentos/métodos , Concentración de Iones de Hidrógeno , Límite de Detección , Cloruro de Sodio/química , Espectrometría de Masas en Tándem/métodos
8.
Food Chem ; 315: 126299, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-32028201

RESUMEN

Polyethylene (PE), polypropylene (PP), polyamide (PA), and polyethylene terephthalate (PET) surfaces and particles were employed to study effects of polymer materials on linseed oil, peanut oil, rapeseed oil and sunflower seed oil oxidation. The surface types of the materials, hydroperoxide content and volatile in oils were determined by contact angle, Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry. Oils on PP surfaces underwent a more rapid oxidation, followed by PA, PE and PET. Except PP sets, this order was consistent with surface hydrophilicity of polymers. Further study using polymer particles avoiding packaging barrier suggested this was probably due to barrier factors. Although PE surfaces allowed oil to have lower content of hydroperoxides, it can promote oil hydroperoxide decomposition into volatile products. Surface types of polymer materials are correlated with oxidation of contacted oil, and these surfaces can also affect the oil secondary oxidation and the degradation of oxidation products.


Asunto(s)
Embalaje de Alimentos , Nylons/química , Aceites de Plantas/química , Polietileno/química , Polipropilenos/química , Verduras/química , Cromatografía de Gases y Espectrometría de Masas , Oxidación-Reducción , Espectroscopía Infrarroja por Transformada de Fourier
9.
Ecotoxicol Environ Saf ; 186: 109746, 2019 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-31606641

RESUMEN

In this paper, polypropylene (PP) nanofibers were prepared using the melt forcespinning technology by a handmade device. Then, the surface of PP nanofibers was grafted through the high energy electron beams (EB) pre-irradiation method by acrylonitrile and methacrylic acid monomers with grafting percentage of 145.55%. The 92% of grafted cyano functional groups on nanofibers were converted to amidoxime groups, then modified by an alkaline solution. Characterization and surface morphology of nanofibers were investigated by Fourier Transform Infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The produced adsorbent was used to adsorb U(VI) ions from simulated seawater. The maximum adsorption was 83.24 mg/g in the optimal time of 60 min and optimal pH of 4. The optimum desorption efficiency was 80% in HCl 0.5 M. The kinetic data in optimum conditions showed that the adsorption followed an S-shaped kinetic model. The Adsorption equilibrium studies presented S-shape isotherm model that confirmed the adsorption occurs both on the adsorbent surface and in its pores The thermodynamic studies indicated spontaneous adsorption of uranyl ions and the higher efficiency adsorption at higher temperatures. The selectivity of adsorbent for metal ions followed the order V(V)>U(VI)>CO(II)>Ni(II)>Fe(II). These results shows that the prepared and modified nanofibers in this work can be considered as an effective and promising adsorbents for removal of uranium ions from seawater with high efficiency.


Asunto(s)
Restauración y Remediación Ambiental/métodos , Nanofibras/química , Polipropilenos/química , Agua de Mar/química , Uranio/química , Contaminantes Químicos del Agua/química , Adsorción , Concentración de Iones de Hidrógeno , Iones/química , Cinética , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica
10.
J Food Sci ; 84(11): 3194-3203, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31589346

RESUMEN

A multilayer film containing star anise essential oil and thymol coating layers (SAEO and TH, respectively), with insect repellent and antimicrobial properties, has been developed using bar coating and adhesive lamination processes. Our previous study reported the in vitro activities of this polypropylene film (PP)/SAEO/polyethylene terephthalate film (PET)/TH/low-density polyethylene film (LDPE) multilayer film. The current study focused on demonstrating the morphological, optical, and mechanical properties of the film, and evaluating its in vivo activities when used as a bread packaging material. The developed film was 15.03% thicker and 1.86% less transparent than the control film (without active agent coating layers: PP/PET/LDPE). While the color values of the developed film were slightly different from the control film, both films appeared similar to the naked eye. The tensile strength in the developed film was somewhat lower than that of the control film, while both films had statistically comparable values for elongation at break. During storage of sliced bread packaged in the developed film, the film both deterred insects from approaching toward and impeded the growth of microorganisms in the bread. These results suggest the potential applicability of the developed film as an active food packaging material with insect repellent and antimicrobial activities. PRACTICAL APPLICATION: A multilayer film incorporated with insect repellent and antimicrobial coating layers was applied in sliced wheat bread packaging. The developed film effectively inhibited approaches of stored-product insects to packaged bread and growth of microorganisms on the bread surface. It can be used as an active food packaging material that improves the safety and shelf-life of foods.


Asunto(s)
Antibacterianos/química , Pan/análisis , Conservación de Alimentos/métodos , Illicium/química , Repelentes de Insectos/química , Aceites Volátiles/química , Timol/química , Animales , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Pan/microbiología , Embalaje de Alimentos/instrumentación , Conservación de Alimentos/instrumentación , Repelentes de Insectos/farmacología , Insectos/efectos de los fármacos , Insectos/crecimiento & desarrollo , Aceites Volátiles/farmacología , Aceites de Plantas/química , Aceites de Plantas/farmacología , Polietileno/química , Polipropilenos/química , Timol/farmacología , Triticum/química , Triticum/microbiología
11.
J Food Sci ; 84(9): 2520-2527, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31408214

RESUMEN

Previous study reported the development of insect-proof halloysite nanotubes (HNTs) and food packaging; however, the duration of their insecticidal properties remains unclear. Here, we aimed to (1) demonstrate the duration of repellency of clove bud oil (CO) encapsulated by HNTs for more than 30 days, and (2) manufacture insect-proof film containing HNTs for commercial use. Also, the release behavior of CO from insect-resistant HNTs was evaluated and HNTs were applied to food packaging composed of polypropylene and low-density polyethylene films to prevent Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) larva infestation. CO, a natural insecticide, was embedded with HNTs and polyethyleneimine (PEI) via vacuum pulling process to cause a slow and gradual release of CO. The sustained release profile of CO from CO-containing HNTs with a PEI coating [(HNTs/CO/layer-by-layer (LBL)] was verified by gas chromatography analysis. The repellent activity of HNTs/CO/LBL was observed for up to 46 days, whereas CO film and HNTs/CO film exhibited no insecticidal activities during the test period. After 30-day exposure, the HNTs/CO/LBL film exhibited a 7-day extension in the penetration test. To evaluate the insecticidal properties of the insect-proof film (HNTs/CO/LBL scale-up film) manufactured in an industrial facility, the inhibitory effects of HNTs/CO/LBL scale-up film on insect infestation was elucidated in both the segregation and combination tests. As a result, HNTs/CO/LBL alone or gravure-printed film treated with HNTs/CO/LBL were capable of protecting food from insect infestation. PRACTICAL APPLICATION: Halloysite nanotubes containing natural insect repellent were applied to industrial production of food packaging. Commercial cornflake cereal packaging using insect-resistant film successfully inhibited pest infestation. Insect-proof film produced at an industrial facility can be utilized to protect processed food from insect infestation.


Asunto(s)
Aceite de Clavo/farmacología , Embalaje de Alimentos/instrumentación , Repelentes de Insectos/farmacología , Insecticidas/farmacología , Lepidópteros/efectos de los fármacos , Nanotubos/química , Animales , Arcilla/química , Aceite de Clavo/química , Repelentes de Insectos/química , Insecticidas/química , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Lepidópteros/crecimiento & desarrollo , Polietileno/química , Polipropilenos/química
12.
Carbohydr Polym ; 218: 243-249, 2019 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-31221327

RESUMEN

Natural cellulose fibers were extracted from a fast growing perennial grass Eulaliopsis binata (commonly known as Sabai) and characterized for their structure and properties. The untreated sabai grass has been used as reinforcement for polypropylene composites and properties of the composites have been investigated. Although the composition of the sabai grass is typical to other lignocellulosic sources, there is a high content of flavonoids (630 mg/g) and phenols (510 mg/g) which provides high antibacterial, and antifungal properties to the fibers and composites developed. Fiber bundles extracted from the grass had tensile strength of 493 MPa and tensile modulus of 21 GPa, similar to common natural cellulose fibers. Both tensile and flexural properties of polypropylene composites increased with increasing ratio of sabai grass. Polypropylene composites reinforced with sabai grass show high noise insulation and thermal resistance properties suggesting their suitability for automotive and building applications.


Asunto(s)
Antibacterianos/farmacología , Antifúngicos/farmacología , Celulosa/farmacología , Extractos Vegetales/farmacología , Poaceae/química , Antibacterianos/química , Antifúngicos/química , Aspergillus niger/efectos de los fármacos , Bacillus cereus/efectos de los fármacos , Celulosa/química , Cryptococcus/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Ensayo de Materiales , Extractos Vegetales/química , Docilidad , Polipropilenos/química , Serratia marcescens/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Resistencia a la Tracción , Conductividad Térmica
13.
J Food Sci ; 84(7): 1836-1843, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31206691

RESUMEN

The polypropylene/poly(vinyl alcohol)/polypropylene (PP/PVA/PP) multilayer active films with controlled release property were developed, of which the intermediate PVA layer was incorporated with 4% (w/w) tea polyphenols (TP) and the microporous PP films with different pore size were used as the internal controlled release layer. The SEM results showed that each layer of these films was agglutinated tightly. With increasing pore size from 171.05 to 684.03 µm, there were little effect on the films' color and opacity, the tensile strength (TS) and elongation at break (EAB) decreased slightly, the gas barrier (O2 and water vapor) property of the film reduced faintly, the time of achieving the release equilibrium in 50% ethanol decreased from 75 hours to 30 hours. The diffusion coefficient for the films increased with the increase of pore size, from 2.06 × 10-11 cm2 /s to 8.06 × 10-11 cm2 /s, suggesting that the release rate of TP increased as the pore size increased. The results were indicated that its release rate could be controlled by adjusting the size of pore. The films also exhibited different antioxidant activities due to their different release profiles of TP. It showed promise for developing the controlled release active packaging film based on this concept. PRACTICAL APPLICATION: Controlled release packaging is propitious to extension of food shelf life. The microporous polypropylene films with different pore size used as the internal layer of polypropylene/poly(vinyl alcohol)/polypropylene (PP/PVA/PP) multilayer active films was proved that the release rate of tea polyphenols in the intermediate PVA layer released from the films into the food simulant can be controlled by adjusting the size of pore in this study. It showed a good prospect for using microporous or perforation-mediated film as the internal layer of multilayer film to develop the controlled release active packaging film for food packaging.


Asunto(s)
Camellia sinensis/química , Preparaciones de Acción Retardada/química , Embalaje de Alimentos/instrumentación , Extractos Vegetales/química , Polifenoles/química , Polipropilenos/química , Alcohol Polivinílico/química , Vapor/análisis , Resistencia a la Tracción
14.
Biomed Res Int ; 2019: 7817063, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30915357

RESUMEN

The aim of the study was to evaluate the effect of propylene film coated with solution of chitosan (CH), ethanolic extracts of propolis (EEP), and bee pollen (EEBP) and its combination on L. monocytogenes number in wrapped salmon, salami, and cheese. Sterile fragments of propylene film were coated with solution containing CH, CH+EEP, CH+EEBP, and CH+EEP+EEBP. The coated film was applied directly after preparation (AP) after 10 days of storage from preparation (AS). L. monocytogenes strains isolated from cheese, salmon, and salami were transferred on adequate food type. ATCC 19111 reference strain was placed on all examined slices. Contaminated slices were wrapped in the coated film. The film adhered strictly to the slices surface and was left for 0, 1, 6, 12, and 24 hours. Antilisterial activity of AP film was additionally assessed during 15-day storage of products wrapped in the coated film. In conclusion, the chitosan-coated film exhibited antibacterial activity. Incorporation of EPP and EEBP enhanced this activity. The antilisterial activity depended on the type and concentration of solutions, the types of food, and the origin of strains. This study proved that the time that passed since the use of coated film for packing food was of great importance.


Asunto(s)
Antibacterianos/química , Quitosano/química , Embalaje de Alimentos , Listeria monocytogenes/crecimiento & desarrollo , Membranas Artificiales , Polen/química , Polipropilenos/química , Própolis/química , Animales , Abejas , Microbiología de Alimentos
15.
Environ Sci Pollut Res Int ; 26(2): 1142-1151, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28685338

RESUMEN

For advanced water treatment, effects of pH and pure polypropylene (PP) beads packing concentration on membrane fouling and treatment efficiency were observed in a hybrid process of alumina ceramic microfiltration (MF; pore size 0.1 µm) and pure PP beads. Instead of natural organic matters and fine inorganic particles in natural water source, a quantity of humic acid (HA) and kaolin was dissolved in distilled water. The synthetic feed flowed inside the MF membrane, and the permeated water contacted the PP beads fluidized in the gap of the membrane and the acryl module case with outside UV irradiation. Periodic air back-flushing was performed to control membrane fouling during 10 s per 10 min. The membrane fouling resistance (Rf) was the maximum at 30 g/L of PP bead concentration. Finally, the maximum total permeated volume (VT) was acquired at 5 g/L of PP beads, because flux maintained higher all through the operation. The treatment efficiency of turbidity was almost constant, independent of PP bead concentration; however, that of dissolved organic materials (DOM) showed the maximal at 50 g/L of PP beads. The Rf increased as increasing feed pH from 5 to 9; however, the maximum VT was acquired at pH 6. It means that the membrane fouling could be inhibited at low acid condition. The treatment efficiency of turbidity increased a little, and that of DOM increased from 73.6 to 75.7% as increasing pH from 5 to 9.


Asunto(s)
Óxido de Aluminio/química , Filtración/métodos , Polipropilenos/química , Rayos Ultravioleta , Purificación del Agua/métodos , Membranas Artificiales
16.
J Food Sci ; 83(12): 3035-3043, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30457667

RESUMEN

A multifunctional film with insect-repellent and antimicrobial activities was developed. Star anise (Illicium verum Hook. f.) oil (SO) proved to be effective in repelling Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) larvae and was selected as an insect-repellent agent. Thymol, a compound that demonstrated strong growth inhibition activities against both Staphylococcus aureus and Penicillium roqueforti, was selected as an antimicrobial agent. Based on the release profile test of SO using various plastic films, polypropylene (30 µm; PP 30) and low-density polyethylene (20 µm; LDPE 20) were selected as laminated films for sustainable insect-repellent and strong antimicrobial effects, respectively. Further, polyethylene terephthalate (12 µm; PET 12) was selected as an intermediate barrier layer. Finally, structure of the multilayer film was designed as PP 30/SO/PET 12/thymol/LDPE 20. The developed film demonstrated insect-repellent activity for >3 weeks, antibacterial activity for >2 weeks, and antifungal activity for 1 week. The results indicated that the developed multilayer film structure possessed strong, sustained insect-repellent and antimicrobial effects, providing a new possibility for the industrial applications to food packaging. PRACTICAL APPLICATION: A multifunctional active packaging film with insect-repellent and antimicrobial activities was developed. Star anise oil and thymol that showed insect-repellent and antimicrobial activities (antibacterial and antifungal activities), respectively, were added in coating layers in the multilayer film structure. The developed multilayer film proved an efficient insect-repellent activity against Plodia interpunctella for >3 weeks. Also, strong antibacterial and antifungal activities of the developed multilayer film were proved against Staphylococcus aureus and Penicillium roqueforti, respectively. The developed film has a potential for the industrial use to the food packaging material.


Asunto(s)
Antibacterianos/química , Antifúngicos/química , Embalaje de Alimentos , Repelentes de Insectos/química , Animales , Illicium/química , Larva/efectos de los fármacos , Lepidópteros/efectos de los fármacos , Penicillium/efectos de los fármacos , Aceites de Plantas/química , Polietileno/química , Tereftalatos Polietilenos/química , Polipropilenos/química , Staphylococcus aureus/efectos de los fármacos , Timol/química
17.
J Colloid Interface Sci ; 460: 237-46, 2015 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-26342973

RESUMEN

Carbonaceous nanofibers (CNFs) were synthesized using tellurium nanowires as a template and using glucose as carbon source by the hydrothermal carbonization method. The sorption capacity and mechanism of U(VI) on CNFs were investigated by a combination of batch sorption experiments, the double layer model (DLM) and X-ray photoelectron spectroscopy (XPS). The sorption edges were modeled well by considering the following surface complexes: SOUO2(+), SOUO2OH, SOUO2(OH)2(-) and SOUO2(OH)3(2-) on the strong site as well as XOUO2OH and XOUO2(+) on the weak one (S and X represent surface). The sorption isotherms could be well fitted by the DLM parameters. The difference between type A (SOUO2OH and XOUO2OH) and type B (SOUO2(+) and XOUO2(+)) was observed in XPS because the former species are of low binding energy while the latter are of high one. Desorption and recycle experiments showed that CNFs had good reusability and stability in the present of common sodium salts within five rounds. When co-existing with montmorillonite, CNFs could extract the sorbed uranium onto their surface by a pseudo-second order kinetic process. As a new sort of environmental functional nanomaterials, CNFs should be paid more attention in the area of separation and wastewater remediation.


Asunto(s)
Carbono/química , Nanofibras/química , Nanotecnología/métodos , Nanotubos de Carbono/química , Adsorción , Bentonita/química , Concentración de Iones de Hidrógeno , Cinética , Microscopía Electrónica de Transmisión , Nanoestructuras , Espectroscopía de Fotoelectrones , Polipropilenos/química , Sodio/química , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Telurio/química , Uranio/química , Aguas Residuales , Contaminantes Químicos del Agua , Purificación del Agua , Rayos X
18.
Nanomedicine (Lond) ; 10(17): 2709-23, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26328770

RESUMEN

Reactive oxygen species (ROS) are generated from the endogenous oxidative metabolism or from exogenous pro-oxidant exposure. Oxidative stress occurs when there is excessive production of ROS, outweighing the antioxidant defense mechanisms which may lead to disease states. Hydrogen peroxide (H2O2) is one of the most abundant and stable forms of ROS, implicated in inflammation, cellular dysfunction and apoptosis, which ultimately lead to tissue and organ damage. This review is an overview of the role of ROS in different diseases. We will also examine ROS-activated nanomaterials with emphasis on hydrogen peroxide, and their potential medical implications. Further development of the biocompatible, stimuli-activated agent responding to disease causing oxidative stress, may lead to a promising clinical use.


Asunto(s)
Antioxidantes/química , Nanoestructuras/química , Especies Reactivas de Oxígeno/química , Nanomedicina Teranóstica/métodos , Animales , Apoptosis , Boro/química , Ésteres/química , Humanos , Peróxido de Hidrógeno/química , Oxalatos/química , Estrés Oxidativo , Polipropilenos/química , Prolina/química , Especies de Nitrógeno Reactivo/química , Selenio/química , Transducción de Señal , Silicio/química , Sulfuros/química , Superóxidos/química
19.
Mar Pollut Bull ; 96(1-2): 286-93, 2015 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-25963573

RESUMEN

Oil is principally one of the most important energy sources in the world. However, as long as oil is explored and transported for being used, there will be the risk of the spillage into the marine environment. The use of technical textiles, i.e. fibrous beds, is a conventional separation technique for oil/water emulsion since it is efficient and easy to design. In this paper, the recovery of oil by technical textiles was mathematically modeled based on the structural parameters of textile and the capillary mechanism. Eleven types of commercial technical textiles with different properties were prepared for the experimental program. The experimental design included fiber type (polypropylene and polyester), fabric type (woven and/or nonwoven), fabric thickness and fabric areal density. Consequently, the absorption capacities of different technical textile samples were derived by the use of theoretical and experimental methods. The results show that there is a well fitness between theoretical outputs and experimental data.


Asunto(s)
Restauración y Remediación Ambiental/métodos , Modelos Químicos , Petróleo , Agua de Mar/química , Textiles , Contaminantes Químicos del Agua/química , Desastres , Contaminación por Petróleo , Polipropilenos/química
20.
ACS Appl Mater Interfaces ; 7(8): 4869-74, 2015 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-25679117

RESUMEN

Nonvolatile memory thin-film transistors (TFTs) fabricated on paper substrates were proposed as one of the eco-friendly electronic devices. The gate stack was composed of chicken albumen gate insulator and In-Ga-Zn-O semiconducting channel layers. All the fabrication processes were performed below 120 °C. To improve the process compatibility of the synthethic paper substrate, an Al2O3 thin film was introduced as adhesion and barrier layers by atomic layer deposition. The dielectric properties of biomaterial albumen gate insulator were also enhanced by the preparation of Al2O3 capping layer. The nonvolatile bistabilities were realized by the switching phenomena of residual polarization within the albumen thin film. The fabricated device exhibited a counterclockwise hysteresis with a memory window of 11.8 V, high on/off ratio of approximately 1.1 × 10(6), and high saturation mobility (µsat) of 11.5 cm(2)/(V s). Furthermore, these device characteristics were not markedly degraded even after the delamination and under the bending situration. When the curvature radius was set as 5.3 cm, the ION/IOFF ratio and µsat were obtained to be 5.9 × 10(6) and 7.9 cm(2)/(V s), respectively.


Asunto(s)
Óxido de Aluminio/química , Ovalbúmina/química , Papel , Transistores Electrónicos , Animales , Pollos , Electricidad , Diseño de Equipo , Microscopía de Fuerza Atómica , Ovalbúmina/metabolismo , Polipropilenos/química
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