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1.
Mol Nutr Food Res ; 68(12): e2400038, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38824669

RESUMEN

SCOPE: Xanthophylls, vital for ocular defense against blue light and reactive oxygen species, are prone to oxidative degradation; however, they may be regenerated antioxidant-rich plant phenols. Despite certain in vitro evidence, clinical studies show inconsistent findings and this may be due to varying phenolic reduction potentials. Therefore, the current study aims to investigate the ocular protective effect of various plant phenols combined with xanthophyll. METHODS AND RESULTS: Human retinal pigment epithelial cells (ARPE-19) are subjected to oxidative stress induced by hydrogen peroxide (H2O2) after xanthophyll and phenol pretreatment. Assessments include xanthophyll uptake, total antioxidant capacity, cell viability, intracellular reactive oxygen species levels, apoptosis, phagocytosis, and vascular endothelial growth factor formation. The study finds that while the combination of lutein with phenols does not show significant protective effects compared to lutein-only, zeaxanthin combined with phenols exhibits enhanced protection compared to both the zeaxanthin-only and control groups. CONCLUSION: The research reveals the complex relationship between xanthophylls and phenols, suggesting that the advantageous effects of their combination might vary among different xanthophylls. Caution is necessary when applying molecular theories to ocular health, and this necessitates further research, serving as a basis for proposing clinical trials to evaluate the efficacy of specific xanthophyll and phenol combinations.


Asunto(s)
Antioxidantes , Apoptosis , Supervivencia Celular , Peróxido de Hidrógeno , Luteína , Estrés Oxidativo , Epitelio Pigmentado de la Retina , Xantófilas , Humanos , Estrés Oxidativo/efectos de los fármacos , Peróxido de Hidrógeno/farmacología , Epitelio Pigmentado de la Retina/efectos de los fármacos , Epitelio Pigmentado de la Retina/metabolismo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Apoptosis/efectos de los fármacos , Xantófilas/farmacología , Luteína/farmacología , Antioxidantes/farmacología , Fenoles/farmacología , Especies Reactivas de Oxígeno/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Zeaxantinas/farmacología , Fagocitosis/efectos de los fármacos
2.
Adv Nutr ; 15(5): 100216, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38582248

RESUMEN

Antioxidants are bioactive molecules that function to scavenge free radicals and balance oxidative stress. Although all antioxidants can act as reactive oxygen species scavengers, their efficacy on eye health may vary. Moreover, the comparative effectiveness and potential additive effect between groups of antioxidants, hitherto, have not been systematically studied. A systematic review and network meta-analysis were conducted to investigate the comparative or additive effect of dietary antioxidant supplements on eye health. Four databases (PubMed, Embase, CINAHL, and Cochrane) were searched, and relevant randomized controlled trials were identified. Out of 60 articles selected for systematic review, 38 were included in the network meta-analysis, categorized into 8 distinct antioxidant-supplemented groups and placebo. All groups significantly increased macular pigment optical density and contrast sensitivity at low spatial frequency, whereas only the antioxidant mixture + lutein (L) + fatty acid combination exhibited significant improvements in visual acuity (hazard ratio = -0.15; 95% confidence interval: -0.28, -0.02) and L + zeaxanthin combination for photostress recovery time (hazard ratio = -5.75; 95% confidence interval: -8.80, -1.70). Especially, the L + zeaxanthin + fatty acid combination was ranked best for macular pigment optical density (surface under the cumulative ranking: 99.3%) and second best for contrast sensitivity at low spatial frequency (67.7%). However, these findings should be interpreted with caution due to low quality of evidence, primarily influenced by indirectness and potential publication bias. Overall, antioxidant supplementation was estimated to improve eye health parameters, whereas different combinations of antioxidants may also have varying effects on improving visual health from multiple perspectives. This study was registered at PROSPERO as CRD42022369250.


Asunto(s)
Antioxidantes , Suplementos Dietéticos , Luteína , Pigmento Macular , Ensayos Clínicos Controlados Aleatorios como Asunto , Agudeza Visual , Humanos , Antioxidantes/administración & dosificación , Antioxidantes/farmacología , Luteína/farmacología , Luteína/administración & dosificación , Agudeza Visual/efectos de los fármacos , Zeaxantinas/farmacología , Zeaxantinas/administración & dosificación , Metaanálisis en Red , Sensibilidad de Contraste/efectos de los fármacos
3.
Nat Prod Res ; : 1-10, 2024 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-38343285

RESUMEN

Thirteen nitrogen-containing derivatives of 3,11-dioxo-olean-12-en-30-oic acid were synthesised by introducing various amino acids and nitrogen-containing heterocyclic groups at the 30-carboxyl group, starting from 18ß-glycyrrhetinic acid. Among the 13 derivatives, 10 exhibited inhibitory activity against HIV-1 PR, with IC50 values ranging from 0.19 to 0.94 mM. Notably, derivatives 2, 3 and 5 displayed relatively moderate inhibitory activity, with IC50 values below 0.24 mM. Molecular docking studies provided further insights into the interaction between derivatives (2, 3 and 5) and the active sites of HIV-1 PR. The results revealed favourable hydrophobic-hydrophobic and hydrogen bonding interactions, with docking scores ranging from -6.22 to -7.00 and glide emodel values from -62.9 to -48.6 (kcal/mol). These findings underscore the potential of derivatives 2, 3 and 5 as promising candidates for the development of HIV-1 PR inhibitors.

4.
Front Plant Sci ; 14: 1251464, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37941672

RESUMEN

Mung bean is a dual-use crop widely cultivated in Southeast Asia as a food and medicine resource. The development of new functional mung bean varieties demands identifying new genes regulating anthocyanidin synthesis and investigating their molecular mechanism. In this study, we used high-throughput sequencing technology to generate transcriptome sequence of leaves, petioles, and hypocotyls for investigating the anthocyanins accumulation in common mung bean variety as well as anthocyanidin rich mung bean variety, and to elucidate their molecular mechanisms. 29 kinds of anthocyanin compounds were identified. Most of the anthocyanin components contents were significantly higher in ZL23 compare with AL12. Transcriptome analysis suggested that a total of 93 structural genes encoding the anthocyanin biosynthetic pathway and 273 regulatory genes encoding the ternary complex of MYB-bHLH-WD40 were identified, of which 26 and 78 were differentially expressed in the two varieties. Weighted gene co-expression network analysis revealed that VrMYB3 and VrMYB90 might have enhanced mung bean anthocyanin content by inducing the expression of structural genes such as PAL, 4CL, F3'5'H, LDOX, and F3'H, which was consistent with qRT-PCR results. These findings are envisaged to provide a reference for studying the molecular mechanism of anthocyanin accumulation in mung beans.

5.
Nutr Rev ; 2023 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-37875097

RESUMEN

This letter acknowledges Finsterer and colleagues' insightful comments on pesticide use in fruits and vegetables and impact on eye health. Pesticides can harm eyes through various exposures. Adverse effects occur due to direct entry into ocular tissues, with absorption through eye components. While the potential of organic diets to reduce pesticide exposure is acknowledged, the original paper's cited studies lack clarity on whether organic diet interventions were used. Future systematic reviews comparing organic and nonorganic diets could provide further insights.

6.
Food Funct ; 14(18): 8321-8330, 2023 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-37605542

RESUMEN

Background: Oxidative stress is a key risk factor for visual impairment and consuming dietary antioxidant-rich foods may help in managing visual impairments. However, a limited number of studies have investigated the effect of dietary antioxidant-rich food including grapes on eye health in older adults. Objectives: To assess the effects on macular pigment accumulation of regular consumption of grapes in Singapore older adults. Methods: This was a 16 week, double-blind, randomized, placebo-controlled trial. Thirty-four Singapore older adults were randomized into regularly consuming either 46 g day-1 of freeze-dried table grape powder (the intervention group) or the same amount of placebo powder (the control group). Macular pigment optical density (MPOD), skin carotenoid status, advanced glycation end product (AGEs) status and dietary lutein intake were assessed every 4 weeks, and plasma lutein concentration, total antioxidant capacity and total phenolic content were measured every 8 weeks. Results: A significant time effect (p = 0.007) was observed for MPOD, and this is largely attributed to the improvement in the MPOD for the intervention group, as a significant increase was observed only in this group (week 0: 0.56 ± 0.04 D.U.; week 16: 0.61 ± 0.04 D.U., p < 0.01). Additionally, a significant increase in plasma total antioxidant capacity (week 0: 0.26 ± 0.13 mM TEAC; week 16: 0.36 ± 0.20 mM TEAC, p < 0.01) and total phenolic content (week 0: 10.50 ± 0.44 mg L-1 GAE; week 16: 12.58 ± 0.55 mg L-1 GAE, p < 0.001) was observed for the intervention group only. In contrast, a significant increase in skin AGE status was observed in the control group (week 0: 2.47 ± 0.24; week 16: 2.99 ± 0.12, p < 0.05) while this was mitigated in the intervention group. There were no differences in dietary lutein intake, plasma lutein concentration and skin carotenoid status between groups throughout the study. Conclusions: Regular intake of grapes may improve eye health in Singapore older adults, specifically in augmenting MPOD, which can be explained by an increase in plasma total antioxidant capacity and phenolic content, and the downregulation of AGEs. This study was registered at clinicatrials.gov as NCT05064865.


Asunto(s)
Pigmento Macular , Vitis , Antioxidantes , Luteína , Polvos , Singapur , Aditivos Alimentarios , Fenoles , Productos Finales de Glicación Avanzada
7.
BMC Public Health ; 23(1): 1109, 2023 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-37291522

RESUMEN

BACKGROUND: The major emerging infectious diseases (MEIDs) have occurred frequently and become increasingly serious in the world. Sufficient personal emergency preparedness is critical for the general people in efficiently responding to and recovering from MEIDs. Nevertheless, few specific indicators are available for assessing the individual emergency preparedness of the general public during these periods. Therefore, the aim of this study was to construct an index system for comprehensively evaluating the personal emergency preparedness of the public regarding MEIDs. METHODS: Based on the global national-level emergency preparedness index framework and a literature review, a preliminary index system was constructed. From June 2022 to September 2022, a panel of 20 experts from nine provinces and municipalities across multiple research areas participated in this Delphi study. They rated the importance of pre-defined indicators using a five-point Likert scale and provided their qualitative comments. According to the feedback of each round of experts, the indicators of the evaluation index system were revised. RESULTS: After two rounds of expert consultation the evaluation index system reached a consensus, containing five first-level indicators, cooperating with prevention and control work, improving emergency response capacity, securing supplies and equipment, preparing economic resources, maintaining physical and mental health with affiliated 20 s-level indicators and 53 third-level indicators. The expert authority coefficient of consultation was 0.88 and 0.90. The Kendall's coefficient of concordance of expert consultations was 0.294 and 0.322, respectively. The differences were statistically significant (P < 0.05). CONCLUSION: A valid, reliable and scientific evaluation index system was established. This personal emergency preparedness index system, as a precursor form, will further lay the foundation for the formation of an assessment instrument. At the same time, it could provide a reference for future education and training of emergency preparedness for the general public.


Asunto(s)
Defensa Civil , Enfermedades Transmisibles Emergentes , Humanos , Técnica Delphi , Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/prevención & control , Brotes de Enfermedades/prevención & control , Consenso
8.
Nutr Rev ; 82(1): 34-46, 2023 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-37094947

RESUMEN

CONTEXT: Xanthophyll intake is known to improve eye health; however, its benefits on visual outcomes have not been systematically studied, particularly in a population with eye diseases. OBJECTIVE: A systematic review, meta-analysis, and meta-regression were conducted to investigate the effect of xanthophyll intake on visual outcomes, and further subgroup analysis was performed on the basis of eye disease status. DATA SOURCES: The PubMed, Scopus, Embase, CINAHL, Cochrane, and Web of Science databases were searched, and relevant randomized controlled trials were identified. DATA EXTRACTION: For systematic review, meta-analysis, and meta-regression, 43, 25, and 21 articles were selected, respectively. DATA ANALYSIS: Xanthophyll intake enhanced macular pigment optical density (MPOD) for both heterochromatic flicker photometry (weighted mean difference [WMD], 0.05; 95% confidence interval [CI], 0.03-0.07) and autofluorescence imaging (WMD, 0.08; 95%CI, 0.05-0.11) measurements and decreased photostress recovery time (WMD, -2.35; 95%CI, -4.49 to -0.20). While enhancement in visual acuity logarithm of the minimum angle of resolution was observed in response to the xanthophyll-rich food and supplement intake only for patients with eye disease (WMD, -0.04; 95%CI, -0.07 to -0.01). Meta-regression showed a positive correlation between change in MPOD (heterochromatic flicker photometry) and the corresponding change in serum lutein levels (regression coefficient = 0.068; P = 0.00). CONCLUSION: Intake of xanthophyll-rich food or supplements can improve eye health. Additional improvement in visual acuity was observed in patients with eye disease. A positive association between MPOD and serum lutein level, while absent with dietary xanthophyll intake, suggests the importance of bioavailability when examining the effect of xanthophyll on eye health. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42021295337.


Asunto(s)
Oftalmopatías , Luteína , Adulto , Humanos , Zeaxantinas , Ensayos Clínicos Controlados Aleatorios como Asunto , Xantófilas , Suplementos Dietéticos
9.
ACS Appl Mater Interfaces ; 14(12): 14579-14587, 2022 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-35311286

RESUMEN

Thermal percolation in polymer nanocomposites─the rapid increase in thermal transport due to the formation of networks among fillers─is the subject of great interest in thermal management ranging from general utility in multifunctional nanocomposites to high-conductivity applications such as thermal interface materials. However, It remains a challenging subject encompassing both experimental and modeling hurdles. Successful reports of thermal percolation are exclusively found in high-aspect-ratio, conductive fillers such as graphene, albeit at filler loadings significantly higher than the electrical percolation threshold. This anomaly was attributed to the lower filler-matrix thermal conductivity contrast ratio kf/km ∼104 compared to electrical conductivity ∼1012-1016. In a randomly dispersed composite, the effect of a low contrast ratio is further accentuated by uncertainties in the morphology of the percolating network and presence of other phases such as disconnected aggregates and colloidal dispersions. Thus, the general properties of percolating networks are convoluted as they lack a defined structure. In contrast, a prototypical system with controllable nanofiller placement enables the elucidation of structure-property relations such as filler size, loading, and assembly. Using self-assembled nanocomposites with a controlled 1,2,3-dimension nanoparticle (NP) arrangement, we demonstrate that thermal percolation can be achieved in spite of using spherical, nonconductive fillers (kf/km ∼60) at a low volume fraction (9 vol %). We observe that the effects of volume fraction, interfacial thermal resistance, and filler conductivity on thermal conductivity depart from effective medium approximations. Most notably, contrast ratio plays a minor role in thermal percolation above kf/km ∼60─a common range for semiconducting nanoparticles/polymer ratios. Our findings bring new perspectives and insights to thermal percolation in nanocomposites, where the limits in contrast ratio, interfacial thermal conductance, and filler size are established.

10.
Onco Targets Ther ; 13: 13401-13411, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33408486

RESUMEN

OBJECTIVE: To investigate the effect of TRIM47 on glioma cells and further explore its underlying molecular mechanisms. METHODS: Mouse xenograft model was used in this study. The mRNA expression of TRIM47 was detected by qRT-PCR. The cell viability and proliferation activity was detected by MTT assay and colony formation assay. The migration and invasion of glioma cells were determined by Transwell assay. The protein levels of TRIM47, FOXO1, CyclinD1, C-myc, MMP-2 and TIMP-1 were assessed by Western-blotting. The interaction between TRIM47 and FOXO1 was measured by Co-immunoprecipitation (Co-IP) assay. RESULTS: In glioma tissues and cells, TRIM47 was significantly up-regulated. Silencing the expression of TRIM47 inhibited the cell viability and proliferation of cells A172 and U251, as well as their ability to invade and migrate. Among them, the expression levels of C-myc and CyclinD1 also decreased, and MMP-2 was down-regulated and TIMP-1 was up-regulated. Similarly, in vivo model, tumor volume and weight also decreased after TRIM47 knockout. Further research showed that TRIM47 inhibited FOXO1 expression by ubiquitination and degradation of FOXO1, thereby promoting glioma growth and progression. CONCLUSION: In our study, we confirmed functional role of the TRIM47-FOXO1 axis in the progression of gliomas and provided a potential target for glioma treatment.

11.
J Cutan Pathol ; 45(3): 223-225, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29193208

RESUMEN

Granular cell basal cell carcinoma (BCC) is a rare histopathological variant of BCC. Our review of the literature revealed only 17 previously identified cases. We report the case of a 47-year-old man who presented with an ulceration on his right upper lip which was subsequently removed. Histopathologic examination revealed that the tumor was composed solely of granular cells with numerous cytoplasmic eosinophilic round inclusion bodies. Mitotic figures ranged from 8 to 15 per 10 high-power fields, with a Ki-67 proliferative index of ~5%. Immunohistochemically, the granular cells showed strong and diffuse positivity for Ber-EP4, pan-cytokeratin, AE1/AE3, CK5/6 and p63 and focal positivity for lysozyme, CD68 (clone KP1) and Bcl-2.


Asunto(s)
Carcinoma Basocelular/patología , Neoplasias Cutáneas/patología , Tumor de Células Granulares/patología , Humanos , Masculino , Persona de Mediana Edad
12.
Chem Commun (Camb) ; 54(11): 1307-1310, 2018 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-29271429

RESUMEN

Inspired by metabolic processes in biological systems, animal blood as a biowaste rich in biological enzymes with molecular Fe-N centers was successfully explored to produce an efficient electrocatalyst with single atomic Fe-N-C active sites for oxygen reduction reaction.

13.
ACS Appl Mater Interfaces ; 9(34): 28473-28477, 2017 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-28792723

RESUMEN

Metal-nitrogen coordination sites, M-Nx (M = Fe, Co, Ni, etc.), have shown great potential to replace platinum group materials as electrocatalysts for oxygen reduction reaction (ORR). However, the real active site in M-Nx is still vague to date due to their complicated structure and composition. It is therefore highly desirable but challenging to develop ORR catalysts with novel and clear active sites, which could meet the needs of comprehensive understanding of structure-function relationships and explore new cost-effective and efficient ORR electrocatalysts. Herein, well-defined M-O6 coordination in metal-catecholates (M-CATs, M = Ni or Co) is discovered to be catalytically active for ORR via a four-electron-dominated pathway. In view of no pyrolysis involved and unambiguous crystalline structure of M-CATs, the M-O6 octahedral coordination site with distinct structure is determined as a new type of active site for ORR. These findings extend the scope of metal-nonmetal coordination as an active site for ORR and pave a way for bottom-up design of novel electrocatalysts containing M-O6 coordination.

14.
Carbohydr Polym ; 101: 1043-60, 2014 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-24299873

RESUMEN

Bacterial cellulose (BC) is a fascinating and renewable natural nanomaterial characterized by favorable properties such as remarkable mechanical properties, porosity, water absorbency, moldability, biodegradability and excellent biological affinity. Intensive research and exploration in the past few decades on BC nanomaterials mainly focused on their biosynthetic process to achieve the low-cost preparation and application in medical, food, advanced acoustic diaphragms, and other fields. These investigations have led to the emergence of more diverse potential applications exploiting the functionality of BC nanomaterials. This review gives a summary of construction strategies including biosynthetic modification, chemical modification, and different in situ and ex situ patterns of functionalization for the preparation of advanced BC-based functional nanomaterials. The major studies being directed toward elaborate designs of highly functionalized material systems for many-faceted prospective applications. Simple biosynthetic or chemical modification on BC surface can improve its compatibility with different matrix and expand its utilization in nano-related applications. Moreover, based on the construction strategies of functional nanomaterial system, different guest substrates including small molecules, inorganic nanoparticles or nanowires, and polymers can be incorporated onto the surfaces of BC nanofibers to prepare various functional nanocomposites with outstanding properties, or significantly improved physicochemical, catalytic, optoelectronic, as well as magnetic properties. We focus on the preparation methods, formation mechanisms, and unique performances of the different BC derivatives or BC-based nanocomposites. The special applications of the advanced BC-based functional nanomaterials, such as sensors, photocatalytic nanomaterials, optoelectronic devices, and magnetically responsive membranes are also critically and comprehensively reviewed.


Asunto(s)
Bacterias/química , Celulosa/análogos & derivados , Nanocompuestos/química , Nanotecnología/métodos , Bacterias/metabolismo , Celulosa/biosíntesis , Celulosa/química
15.
Biosens Bioelectron ; 49: 450-6, 2013 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-23811477

RESUMEN

Glycated hemoglobin (HbA1c) is one of the most important diagnostic assays for the long-term mark of glycaemic control in diabetes. This study presents an affinity biosensor for HbA1c detection which is label-free based on the impedance measurement, and it features low cost, low sample volume, and requires no additional reagent in experiments. The ring-shaped interdigital electrodes (RSIDEs) are designed to promote the distribution uniformity and immobilization efficiency of HbA1c, and are further employed to characterize the impedance change and identify various concentrations of HbA1c. The self-assembled monolayer (SAM) of thiophene-3-boronic acid (T3BA) is provided to modify the gold electrode surface. Afterwards, the esterification reaction between HbA1c and T3BA produces a relative change of electrical property on the electrode surface. The RSIDEs with SAM of T3BA exhibit a wide range from 100 to 10 ng/µL producing an approximate logarithmic decrease of impedance, a low detection limit of 1 ng/µL, a good selectivity and short-term stability for HbA1c determination. The remarkable advantages (miniaturization and low-cost) fill the bill of point-care diagnostics for portable sensor development.


Asunto(s)
Técnicas Biosensibles/instrumentación , Hemoglobina Glucada/análisis , Ácidos Borónicos/química , Impedancia Eléctrica , Electrodos , Diseño de Equipo , Oro/química , Humanos , Límite de Detección , Tiofenos/química
16.
Carbohydr Polym ; 92(2): 1953-9, 2013 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-23399243

RESUMEN

Zinc oxide nanoparticles have been successfully synthesized through a facile polyol method using bacterial cellulose (BC) as a template. BC membrane was used as a host matrix to introduce quantitatively Zn(2+) ions and then as nanoreactors to fabricate ZnO nanoparticles by hydrolysis of zinc acetate in a polyol medium. The influence of the concentration of zinc acetate and hydrolytic time on the morphologies and size of ZnO nanoparticles were investigated. The results indicated that the uniform spherical ZnO nanoparticles were incorporated into BC fibers. The resulting nanocomposites show good mechanical properties and high photocatalytic activity in the degradation of methyl orange.


Asunto(s)
Celulosa/química , Gluconacetobacter xylinus/química , Glicoles/química , Nanopartículas/química , Óxido de Zinc/química , Óxido de Zinc/síntesis química , Catálisis , Técnicas de Química Sintética , Hidrólisis , Fenómenos Mecánicos , Modelos Moleculares , Conformación Molecular , Procesos Fotoquímicos , Porosidad , Temperatura , Acetato de Zinc/química
17.
Biodegradation ; 24(5): 685-98, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23266763

RESUMEN

Experiments were conducted in a laboratory-scale biofilter to assess the ability of a fixed-film biological process to treat an air stream containing ß-caryophyllene, a sesquiterpene emitted by a variety of conifer trees as well as industrial wood processing operations. Treatment performance was evaluated under a variety of pollutant loading conditions and nutrient supply rates over an operational period lasting more than 240 days. At empty bed contact times (EBCTs) as low as 10 s and daily average pollutant loading rate as high as 24.2 g C/(m(3) h) (grams pollutant measured as carbon per cubic meter packed bed volume per hour), removal efficiencies in excess of 95 % were observed when sufficient nutrients were supplied. Results demonstrate that, as with biofilters treating other compounds, biofilters treating ß-caryophyllene can experience local nutrient limitations that result in diminished performance. The biofilter successfully recovered high removal efficiency within a few days after resumption of pollutant loading following a 14-day interval of no contaminant loading. Construction of a 16S rRNA gene library via pyrosequencing revealed the presence of a high proportion of bacteria clustering within the genera Gordonia (39.7 % of the library) and Rhodanobacter (37.6 %). Other phylotypes detected at lower relative abundances included Pandoraea (6.2 %), unclassified Acetobacteraceae (5.5 %), Dyella (3.3 %), unclassified Xanthomonadaceae (2.6 %), Mycobacterium (1.8 %), and Nocardia (0.6 %). Collectively, results demonstrate that ß-caryophyllene can be effectively removed from contaminated gas streams using biofilters.


Asunto(s)
Contaminantes Atmosféricos/aislamiento & purificación , Filtración/métodos , Consorcios Microbianos , Sesquiterpenos/aislamiento & purificación , Bacterias/genética , Bacterias/metabolismo , Secuencia de Bases , Biodegradación Ambiental , Filtración/instrumentación , Sesquiterpenos Policíclicos , ARN Ribosómico 16S/genética , Compuestos Orgánicos Volátiles/análisis
18.
Phys Chem Chem Phys ; 14(41): 14249-54, 2012 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-22932688

RESUMEN

White polymer phosphorescent light-emitting diodes have been fabricated employing silver nanowire (AgNW)-polymer composite substrates. Solution processing is used to form all the layers in the devices, except for the cathode, for potentially low fabrication cost. The current efficiency in the front viewing direction is 20.3 cd A(-1) for devices comprising two complementary dopants (bis[(4,6-difluorophenyl)-pyridinato-N,C(2)] (picolinato)Ir(iii) (FIrpic) with sky blue emission and bis(1-phenylisoquinoline)(acetylacetonate) (Ir(piq)) for red emission). The efficiency is 42.3 cd A(-1) at 4000 cd cm(-2) for devices comprising the three primary colors (FIrpic, Ir(piq), and tris(2-(4-tolyl)pyridinato-N,C(2)) (Ir(mppy)(3)), with green emission). These values are, respectively, 35% and 41% higher than those of control devices fabricated on indium tin oxide (ITO) coated on glass substrates. The enhanced current efficiency is attributed to enhanced light out-coupling thanks to light scattering by the silver nanowires embedded in the transparent composite electrode.

19.
Nanotechnology ; 23(34): 344002, 2012 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-22885805

RESUMEN

Stretchable transparent composites have been synthesized consisting of a silver nanowire (AgNW) network embedded in the surface layer of a crosslinked poly(acrylate) matrix. The interpenetrating networks of AgNWs and the crosslinked polymer matrix lead to high surface conductivity, high transparency, and rubbery elasticity. The presence of carboxylic acid groups on the polymer chains enhances the bonding between AgNWs and the polymer matrix, and further increases the stretchability of the composites. The sheet resistance of the composite electrode increases by only 2.3 times at 50% strain. Repeated stretching to 50% strain and relaxation only causes a small increase of the sheet resistance after 600 cycles. The morphology of the composites during reversible stretching and relaxation has been investigated to expound the conductivity changes.

20.
Adv Mater ; 24(10): 1321-7, 2012 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-22302290

RESUMEN

A new compliant electrode-based on silver nanowire-polymer composite has been developed. The composite electrode has low sheet resistance (as low as 10 Ω/sq), remains conductive (10(2) -10(3) Ω/sq) at strains as high as 140%, and can support Joule heating. The combination of the composite and a bistable electroactive polymer produces electrically-induced, large-strain actuation and relaxation, reversibly without the need of mechanical programming.


Asunto(s)
Nanocompuestos/química , Nanocables/química , Polímeros/química , Plata/química , Estrés Mecánico , Acrilatos/química , Electrodos , Propiedades de Superficie
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