RESUMEN
BACKGROUND: Carotenoids and docosahexaenoic acid (DHA) were identified as essential components for eye health and are both naturally present in eggs. OBJECTIVE: We aimed to evaluate the effect of the daily consumption of two eggs enriched with lutein/zeaxanthin and DHA on macular pigment optical density (MPOD) and on circulating xanthophyll and fatty acid concentrations in healthy participants. METHODS: Ninety-nine healthy volunteers consumed either two standard eggs or two enriched eggs per day for 4 months. MPOD was measured at baseline (V0) and at follow-up (V4) using a modified confocal scanning laser ophthalmoscope (primary outcome). Blood samples were collected to determine total plasma and lipoprotein fatty acids and lutein/zeaxanthin compositions at V0 and V4 (secondary outcomes). RESULTS: A slight but significant increase in MPOD was observed for all study participants consuming two eggs per day for 4 months at all eccentricities (0.5°, 1°, 2°, and 4°). Plasma and lipoprotein lutein, zeaxanthin, and DHA concentrations significantly increased in both groups but were greater in the enriched group (for the enriched group (V0 vs. V4): lutein, 167 vs. 369 ng/mL; zeaxanthin, 17.7 vs. 29.2 ng/mL; DHA, 1.89 vs. 2.56% of total fatty acids). Interestingly, lutein from high-density lipoprotein (HDL) was strongly correlated with MPOD at 0.5 and 1° eccentricities (rho = 0.385, p = 0.008, and rho = 0.461, p = 0.001, respectively). CONCLUSIONS: MPOD was slightly increased in both groups. Lutein, zeaxanthin, and DHA plasma concentrations were strongly enhanced in the enriched group compared with the standard group. A significant correlation was found between MPOD level and lutein concentration in HDL.
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Ácidos Docosahexaenoicos/sangre , Alimentos Fortificados , Luteína/sangre , Pigmento Macular/sangre , Adulto , Eritrocitos/metabolismo , Femenino , Humanos , Lipoproteínas/sangre , Masculino , Fenómenos Ópticos , Cooperación del Paciente , Xantófilas/sangre , Adulto Joven , Zeaxantinas/sangreRESUMEN
The properties of edible films derived from corn starch (CS) and methylcellulose (MC) supplemented with fireweed extract (FE; 0.0125-0.05% w/w) were analyzed. Due to their more crystalline structure, the MC films were significantly stronger (~26 MPa) than the CS films (~4 MPa). In turn, CS produced films with lower water vapor permeability (WVP, 50.12-51.74 vs. 56.52-59.10 g mm m-2 d-1 kPa-1). The hydrothermally-disrupted starch granules contributed to high roughness and opacity of the CS films. The FE-supplemented films exhibited an intensive yellow color and improved the UV-absorbing effect. FE delayed starch retrogradation, as indicated by the reduced crystallinity and slightly improved transparency of the CS films. Incorporation of FE significantly enhanced the released radical scavenging activity (RSA) of the films, while did not affect the WVP and mechanical properties. Due to better FE-trapping capacity, the CS-based films exhibited lower antioxidant activity (RSA60min = 2.21-19.75%) as compared to the MC counterparts (RSA60min = 4.87-38.31%).
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Antioxidantes/farmacología , Bassia scoparia/química , Fenómenos Químicos , Películas Comestibles , Metilcelulosa/química , Extractos Vegetales/química , Almidón/química , Depuradores de Radicales Libres/química , Fenómenos Ópticos , Permeabilidad , Fenoles/análisis , Vapor , Difracción de Rayos XRESUMEN
The effects of new treatments must be investigated in vitro before using clinically or in vivo. The aim of this study was to introduce the Z-scan technique as a fast, accurate, inexpensive, and safe in vitro method to distinguish the cytotoxic effects of various treatments. C6 and OLN-93 cell lines were prepared and treated with Temozolomide (TMZ), radiofrequency hyperthermia (HT), and chemo-hyperthermia (HT+TMZ). The cytotoxic effects of different treatments on both cell lines were evaluated using colony formation assay and Z-scan method. The results of colony assay showed that the surviving fraction (SF) of C6 cells treated with TMZ, HT, and HT + TMZ were significantly decreased compared to the control group. Whereas, hyperthermia treatment had no significant effect on the SF of OLN-93 cells. The results of Z-scan technique indicated that the control group of C6 cells had the negative nonlinear refractive index (n2). Whereas, the C6 cells treated with HT, TMZ, and HT + TMZ had the positive n2 index. The sign of n2 index in the control and HT groups of OLN-93 cells was positive but treatment of cells with TMZ and HT + TMZ changed the sign of it. Moreover, with increasing the cytotoxic effects of different treatments, the SF value of both cell lines decreased and the magnitude of n2 index increased. The results of Z-scan technique were completely in line with the results of colony assay. Therefore, Z-scan method could distinguish the cytotoxic effects of various treatments by examining the nonlinear optical properties of the samples.
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Hipertermia Inducida , Dinámicas no Lineales , Fenómenos Ópticos , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Humanos , Temozolomida/farmacología , Temozolomida/uso terapéuticoRESUMEN
This contribution reports on the optical properties of biosynthesised Eu2O3 nanoparticles bioengineered for the first time by a green and cost effective method using aqueous fruit extracts of Hyphaene thebaica as an effective chelating and capping agent. The morphological, structural, and optical properties of the samples annealed at 500°C were confirmed by using a high-resolution transmission electron microscope (HR-TEM), x-ray diffraction analysis (XRD), UV-Vis spectrocopy, and photoluminescence spectrometer. The XRD results confirmed the characteristic body-centered cubic (bcc) structure of Eu2O3 nanoparticles with an average size of 20 nm. HR-TEM revealed square type morphology with an average size of â¼6nm. Electron dispersion energy dispersive x-ray spectroscopy spectrum confirmed the elemental single phase nature of pure Eu2O3. Furthuremore, the Fourier transformed infrared spectroscopy revealed the intrinsic characteristic peaks of Eu-O bond stretching vibrations. UV-Vis reflectance proved that Eu2O3 absorbs in a wide range of the solar spectrum from the VUV-UV region with a bandgap of 5.1 eV. The luminescence properties of such cubic structures were characterized by an intense red emission centered at 614 nm. It was observed that the biosynthesized Eu2O3 nanoparticles exhibit an efficient red-luminescence and hence a potential material as red phosphor.
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Luminiscencia , Nanopartículas/química , Fenómenos Ópticos , Arecaceae/química , Color , Tamaño de la Partícula , Extractos Vegetales/químicaRESUMEN
Alginate nanocomposite films incorporating sepiolite (Sep) modified with myrtle berries extract (MBE) rich in polyphenols were prepared by solution casting method. The effects of different extract concentrations on the film properties were determined by measuring physicochemical, mechanical and antioxidant properties of the films. Fourier transform infrared (FTIR) spectra indicated that strong interactions between the polyphenols present in the MBE and sepiolite were involved in the films. The results suggested that incorporation of Sep-MBE hybrids into the films improved elongation at break, tensile strength, water vapor and UV barrier properties compared to the control film. The antioxidant activity of the films was significantly improved and raised with increasing content of MBE. The release kinetics results of MBE polyphenols from the active films into alcoholic food simulant indicated that the addition of Sep-MBE hybrids to alginate film is able to slow the release of MBE polyphenols. This study revealed the benefits of incorporation of Sep-MBE hybrids into the alginate films and their potential application as active packaging films or coating material.
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Alginatos/química , Frutas/química , Silicatos de Magnesio/química , Myrtus/química , Nanocompuestos/química , Extractos Vegetales/química , Polifenoles/química , Adsorción , Antioxidantes/farmacología , Rastreo Diferencial de Calorimetría , Módulo de Elasticidad , Humedad , Nanocompuestos/ultraestructura , Fenómenos Ópticos , Permeabilidad , Polifenoles/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Vapor/análisis , Temperatura , Resistencia a la Tracción , Termogravimetría , Agua/químicaRESUMEN
Determining how neurons transform synaptic input and encode information in action potential (AP) firing output is required for understanding dendritic integration, neural transforms and encoding. Limitations in the speed of imaging 3D volumes of brain encompassing complex dendritic arbors in vivo using conventional galvanometer mirror-based laser-scanning microscopy has hampered fully capturing fluorescent sensors of activity throughout an individual neuron's entire complement of synaptic inputs and somatic APs. To address this problem, we have developed a two-photon microscope that achieves high-speed scanning by employing inertia-free acousto-optic deflectors (AODs) for laser beam positioning, enabling random-access sampling of hundreds to thousands of points-of-interest restricted to a predetermined neuronal structure, avoiding wasted scanning of surrounding extracellular tissue. This system is capable of comprehensive imaging of the activity of single neurons within the intact and awake vertebrate brain. Here, we demonstrate imaging of tectal neurons within the brains of albino Xenopus laevis tadpoles labeled using single-cell electroporation for expression of a red space-filling fluorophore to determine dendritic arbor morphology, and either the calcium sensor jGCaMP7s or the glutamate sensor iGluSnFR as indicators of neural activity. Using discrete, point-of-interest scanning we achieve sampling rates of 3 Hz for saturation sampling of entire arbors at 2 µm resolution, 6 Hz for sequentially sampling 3 volumes encompassing the dendritic arbor and soma, and 200-250 Hz for scanning individual planes through the dendritic arbor. This system allows investigations of sensory-evoked information input-output relationships of neurons within the intact and awake brain.
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Encéfalo/crecimiento & desarrollo , Microscopía de Fluorescencia por Excitación Multifotónica/métodos , Neuronas/fisiología , Estimulación Luminosa/métodos , Colículos Superiores/fisiología , Vigilia/fisiología , Estimulación Acústica/métodos , Animales , Química Encefálica/fisiología , Potenciales Evocados Visuales/fisiología , Neuronas/química , Fenómenos Ópticos , Colículos Superiores/química , Factores de Tiempo , Xenopus laevisRESUMEN
Extensive recent progress has been made on the design and applications of organic photothermal agents for biomedical applications because of their excellent biocompatibility comparing with inorganic materials. One major hurdle for the further development and applications of organic photothermal agents is the rarity of high-performance materials in the second near-infrared (NIR-II) window, which allows deep tissue penetration and causes minimized side effects. Up till now, there have been few reported NIR-II-active photothermal agents and their photothermal conversion efficiencies are relatively low. Herein, optical absorption of π-conjugated small molecules from the first NIR window to the NIR-II window is precisely regulated by molecular surgery of substituting an individual atom. With this technique, the first demonstration of a conjugated oligomer (IR-SS) with an absorption peak beyond 1000 nm is presented, and its nanoparticle achieves a record-high photothermal conversion efficiency of 77% under 1064 nm excitation. The nanoparticles show a good photoacoustic response, photothermal therapeutic efficacy, and biocompatibility in vitro and in vivo. This work develops a strategy to boost the light-harvesting efficiency in the NIR-II window for cancer theranostics, offering an important step forward in advancing the design and application of NIR-II photothermal agents.
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Diagnóstico , Diseño de Fármacos , Rayos Infrarrojos/uso terapéutico , Fototerapia/métodos , Bibliotecas de Moléculas Pequeñas/uso terapéutico , Temperatura , Fenómenos Ópticos , Polimerizacion , Bibliotecas de Moléculas Pequeñas/químicaRESUMEN
In the present study, the adsorption of glucose oxidase (GOD) to a mesoporous aluminum oxide (MAO) film was examined with in-situ neutron reflectometry (NR) measurements. The MAO film was deposited on a cover glass slip and a Si disc, and its pore structure was characterized by X-ray reflectometry (XRR) and NR. The Si disc with MAO film was applied for an in-situ NR experiment, and its NR profiles before/after adsorption of GOD were continuously measured with a flow cell. The results indicated that the negatively-charged GOD molecules hardly penetrate into the narrow pore channel (pore diameter = ca. 10 nm) with opposite surface charge.
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Óxido de Aluminio/química , Glucosa Oxidasa/química , Neutrones , Fenómenos Ópticos , Adsorción , Porosidad , Propiedades de SuperficieRESUMEN
The precision delivery of anti-cancer agents which aim for targeted and deep-penetrated delivery as well as a controlled release at the tumor site has been challenged. Here, we fabricate iron oxide nanoparticle shelled microbubbles (NSMs) through self-assembly, synergizing magnetic, acoustic, and optical responsiveness in one nanotherapeutic platform. Iron oxide nanoparticles serve as both magnetic and photothermal agents. Once intravenously injected, NSMs can be magnetically guided to the tumor site. Ultrasound triggers the release of iron oxide nanoparticles, facilitating the penetration of nanoparticles deep into the tumor due to the cavitation effect of microbubbles. Thereafter, magnetic hyperthermia and photothermal therapy can be performed on the tumor for combinational cancer therapy, a solution for cancer resistance due to the tumor heterogeneity. In this protocol, the synthesis and characterization of NSMs including structural, chemical, magnetic and acoustic properties were performed. In addition, the anti-cancer efficacy by thermal therapy was investigated using in vitro cell cultures. The proposed delivery strategy and combination therapy holds great promise in cancer treatment to improve both delivery and anticancer efficacies.
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Acústica , Hipertermia Inducida , Fenómenos Magnéticos , Microburbujas/uso terapéutico , Neoplasias/terapia , Fenómenos Ópticos , Fototerapia/métodos , Terapia Combinada , Sistemas de Liberación de Medicamentos , Humanos , TemperaturaRESUMEN
An interferometric reflectance spectroscopy-based biosensor for the determination of cathepsin B (Cat B) as a cancer-related enzyme has been fabricated. For this purpose, the nanoporous anodic alumina (NAA) was fabricated electrochemically. The NAA was then modified with the amino-silane coupling agent. After that, human serum albumin (HSA) was immobilized into the NAA pores by using glutaraldehyde as a cross-linking agent. Subsequently, the carboxylic group of HSA was activated with N-ethyl-N'-(3-(dimethylamino)propyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS) to attach to thionine (TH) as a photoprobe to fabricate the labeled HSA (HSA-TH). HSA-TH plays a significant role in this sensor to determine cathepsin B as a model analyte for the development of the interferometric reflectance spectroscopy-based biosensor for the measurement of protease. The attached TH adsorbed the illuminated white light on NAA modified with HSA-TH. Therefore, the intensity of the reflected light to the charge-coupled device (CCD) detector decreased in the wavelength range 450-1050 nm. In the presence of Cat B, HAS-TH cleaved into short peptide fragments and washed away by flow cell system. Since TH was removed from NAA, the intensity of the reflected light increased. The peak area has a logarithmic relationship with the concentration of Cat B in the range 0.5 to 64.0 nM. The limit of detection of the biosensor sensor was 0.08 nM. The optical sensor was used for the determination of Cat B in a human serum sample. Graphical abstract Schematic presentation of biosensor for the determination of the cathepsin B which is based on nanoporous anodic alumina modified with HSA-thionine. The principle response of the optical biosensor is based on detecting changes in the intensity of the reflected light after cleaving the immobilized HSA-thionine by cathepsin B into short peptide fragments.
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Óxido de Aluminio/química , Técnicas Biosensibles , Catepsina B/análisis , Técnicas Electroquímicas , Fenotiazinas/química , Albúmina Sérica Humana/química , Catepsina B/metabolismo , Electrodos , Humanos , Fenómenos Ópticos , Tamaño de la Partícula , Porosidad , Propiedades de SuperficieRESUMEN
In this paper, we introduce a novel method for the fabrication of self-assembly plasmonic metamaterials by exploiting fluid instabilities of optical thin films. Due to interplay between template reflow and spinodal dewetting, two metal nanoparticles of different sizes are generated on the top mesas of free-standing porous anodic aluminum oxide (AAO) template, which results in the apprearance of double resonant peaks in the extinction spectrum. These two resonant peaks possess refractive index resolution 3.27 × 10-4 and 2.53 × 10-4 RIU, respectively. This optical intensity modulation based plasmonic nanoplatform shows a dramatically surface sensing performance with outstanding detection capacity of biomolecules, because of the very small decay length of electric field at dual-modes. The detection ability for concanavalin A (Con A) demonstrats that the limit of detection of dual-modes reaches as small as 68 and 79 nM, respectively.
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Técnicas Biosensibles , Fenómenos Ópticos , Óxido de Aluminio/química , Concanavalina A , Electrodos , Unión Proteica , Refractometría , Ribonucleasas/metabolismoRESUMEN
Due to the proven carcinogenicity of Sudan III and IV dyes, they are considered global public health issues. They are banned in all forms as food colourants. We propose the monitoring of simple and easy-to-measure optical properties of palm oils, such as the refractive indices and spectrophotometric properties, as efficient indicators to detect adulteration. Coupling these results with principal component analysis, excess refractive index, and integration of transmittance introduces a novel detection tool for the authentication of edible palm oil. This opens a new opportunity for accurate handheld devices to detect adulteration and provide control in the field. This work assessed in total of 49 samples, some collected from different parts of Ghana and others, in-house adulterated samples. The Ghana Food and Drugs Authority, who performed a complex and expensive chemical analysis of the samples, confirmed our results with good agreement.
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Compuestos Azo/análisis , Carcinógenos/análisis , Colorantes de Alimentos/análisis , Aceite de Palma/química , Análisis de los Alimentos , Fenómenos ÓpticosRESUMEN
Hemozoin, the heme detoxification end product in malaria parasites during their growth in the red blood cells (RBCs), serves as an important marker for diagnosis and treatment target of malaria disease. However, the current method for hemozoin-targeted drug screening mainly relies on in vitro ß-hematin inhibition assays, which may lead to false-positive events due to under-representation of the real hemozoin crystal. Quantitative in situ imaging of hemozoin is highly desired for high-throughput screening of antimalarial drugs and for elucidating the mechanisms of antimalarial drugs. We present transient absorption (TA) imaging as a high-speed single-cell analysis platform with chemical selectivity to hemozoin. We first demonstrated that TA microscopy is able to identify ß-hematin, the artificial form of hemozoin, from the RBCs. We further utilized time-resolved TA imaging to in situ discern hemozoin from malaria-infected RBCs with optimized imaging conditions. Finally, we quantitatively analyzed the hemozoin amount in RBCs at different infection stages by single-shot TA imaging. These results highlight the potential of TA imaging for efficient antimalarial drug screening and drug mechanism investigation.
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Eritrocitos/metabolismo , Hemoproteínas/metabolismo , Microscopía/métodos , Animales , Antimaláricos/farmacología , Cristalización , Evaluación Preclínica de Medicamentos , Eritrocitos/parasitología , Hemoproteínas/análisis , Hemoproteínas/química , Ensayos Analíticos de Alto Rendimiento , Humanos , Malaria Falciparum/sangre , Malaria Falciparum/parasitología , Microscopía Electrónica de Rastreo , Fenómenos Ópticos , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/metabolismo , Análisis de la Célula Individual/métodosRESUMEN
Exploring the spatial relationship of various neuron pools in the spinal cord is crucial and difficult due to its complexity. The single-labelling tracing and sectioning were employed in previous studies exploring the distribution of spinal motor neuron pools, which could only delineate one single motor neuron pool in one specimen and could not achieve intact-tissue observation. Here, with combination of neuroanatomy tracing techniques and the optical clearing technique, we developed a multiple retrograde tracing method compatible with 3DISCO clearing. Fluoro-Gold, Fluoro-Ruby, Cholera Toxin Subunit B, Alexa Fluor 488 and 647 Conjugate were injected intramuscularly in hindlimbs of C57BL/6 adults. After labelling, the harvested spinal cords were optically cleared by 3DISCO method and imaged using confocal microscope. There were positive signals of all four tracers and four motor neurons pools targeting injected muscles were labelled. Three-dimension model of four motor neuron pools was successfully reconstructed based on tomography images showing the spatial relationship of different neuron pools. In conclusion, using this method, we first delineated the spatial relationship of four different motor neuron pools targeting four skeletal muscles in one spinal cord at the same time, which provide a holistic view of motor neuron pools in the spinal cord.
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Microscopía/métodos , Fenómenos Ópticos , Animales , Femenino , Ratones , Ratones Endogámicos C57BL , Neuronas Motoras/citología , Trazadores Radiactivos , Médula Espinal/citología , Médula Espinal/diagnóstico por imagenRESUMEN
Over the past two decades, the development of plasmonic nanoparticle (NPs), especially gold (Au) NPs, is being pursued more seriously in the medical fields such as imaging, drug delivery, and theranostic systems. However, there is no comprehensive review on the effect of the physical and chemical parameters of AuNPs on their plasmonic properties as well as the use of these unique characteristic in medical activities such as imaging and therapeutics. Therefore, in this literature the surface plasmon resonance (SPR) modeling of AuNPs was accurately captured toward precision medicine. Indeed, we investigated the importance of plasmonic properties of AuNPs in optical manipulation, imaging, drug delivery, and photothermal therapy (PTT) of cancerous cells based on their physicochemical properties. Finally, some challenges regarding the commercialization of AuNPs in future medicine such as, cytotoxicity, lack of standards for medical applications, high cost, and time-consuming process were discussed.
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Oro/administración & dosificación , Nanopartículas del Metal/administración & dosificación , Animales , Diagnóstico por Imagen , Sistemas de Liberación de Medicamentos , Humanos , Neoplasias/diagnóstico por imagen , Neoplasias/terapia , Fenómenos Ópticos , FototerapiaRESUMEN
This work aims to explore the addition impact of surface modified cellulose nanofibers (CNF) with poly (methyl methacrylate) (PMMA), CNF-g-PMMA, on the required properties of whey protein isolate (WPI)/walnut oil (WNO) films for packaging applications. WPI/WNO films containing 15â¯wt% WNO were selected for CNF incorporation. The addition effects of different quantities of unmodified and modified CNF (CNF and MCNF) on mechanical strength, fracture surface morphology, hydrophobicity, water vapor permeability (WVP), water uptake, and transparency of bionanocomposite films were studied. Fracture surface was observed by Scanning electron microscopy (SEM). The maximum ultimate tensile strength (UTS) was obtained to be 9⯱â¯0.11 and 10.38⯱â¯0.16â¯MPa, respectively, at 7.5â¯wt% of both CNF and MCNF. Compared with WPI/WNO unfilled films, while CNF increased the hydrophilicity of the films, MCNF resulted in more hydrophobic films. In addition, 51% and 64% improvement in water vapor barrier features of CNF and MCNF-loaded films was observed, respectively. The similar trend was occurred for the water uptake behavior. In the case of film transparency, MCNF-loaded films were opaque with 18.12% light transmittance (600â¯nm wavelength). Generally, WPI films including 15â¯wt% of WNO and 7.5â¯wt% MCNF shows promising potential as bio-packaging films.
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Celulosa/química , Juglans/química , Nanofibras/química , Aceites de Plantas/química , Embalaje de Productos/métodos , Proteína de Suero de Leche/química , Interacciones Hidrofóbicas e Hidrofílicas , Fenómenos Mecánicos , Nanocompuestos/química , Fenómenos Ópticos , Permeabilidad , Vapor , Propiedades de SuperficieRESUMEN
The use of Azadirachta indica (A.I.) leaf extract to synthesize green photocatalysts for efficient separation of photogenerated charges has been a promising way to enhance the photocatalytic activity. Herein, we report the synthesis of green bismuth oxybromide/oxyiodide composites (G-BiOBrxI1-x) using A.I. leaf extract with effective size control, high specific surface area, and porosity. The A.I. leaf extract also acted as an excellent sensitizer that boosted the optical window of the G-BiOBrxI1-x photocatalysts. The as-prepared G-BiOBrxI1-x photocatalysts possessed three-dimensional (3-D) nanoplates like structure with successive modulation of the band gaps from 2.28â¯eV to 1.98â¯eV by varying the bromine/iodine (Br/I) ratio. Furthermore, the photocatalytic activity of the G-BiOBrxI1-x samples was measured and compared with the bismuth oxybromide/oxyiodide composite (C-BiOBr0.5I0.5) synthesized via conventional hydrolysis route (without the leaf extract). The G-BiOBrxI1-x photocatalysts degraded higher percentage of methyl orange (MO) and amoxicillin (AMX) than C-BiOBr0.5I0.5 under visible light irradiation. The superior photocatalytic efficiency was attributed to the multiple heterojunctions developed between BiOBr, BiOI, and electron-accepting π-conjugated system offered by leaf extract constituents, thereby facilitating the charge transfer process and effective separation of photogenerated charges.
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Bismuto/química , Contaminantes Ambientales/química , Yoduros/química , Extractos Vegetales/química , Hojas de la Planta/química , Amoxicilina/química , Azadirachta/química , Compuestos Azo/química , Catálisis , Estructura Molecular , Fenómenos Ópticos , Tamaño de la Partícula , Procesos Fotoquímicos , Propiedades de SuperficieRESUMEN
Rosemary (REO), mint essential oil (MEO), nisin and lactic acid were incorporated at 0.5% to develop a novel functional packaging film including chitosan pectin and starch polymers (0.75:1.5:0.75 w/w). Inclusion of REO and nisin significantly (pâ¯≤â¯0.05) improved water barrier properties (0.014â¯g.mm/m224h), tensile strength (25.95â¯MPa) and thermal stability as compared to control. ATR-FTIR spectra and XRD pattern elucidated structural interaction between EO's and biocomposite films. Addition of REO of and nisin increased microsctructural heterogeneity and opacity (2.78). Incorporation of REO and nisin exhibited the highest inhibitory activity against all tested pathogenic strains (Bacillus subtilis, Escherichia coli, and Listeria monocytogenes). The antioxidant properties of biocomposite films were analyzed using reducing power, metal chelation, DPPH and ABTS radical scavenging assays, which enhanced significantly (pâ¯≤â¯0.05) with the addition of MEO and REO. This study validated that incorporation of natural additives in active biocomposite films offers promising functional ingredients for packaging materials for various food applications.
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Antibacterianos/química , Biopolímeros/química , Aceites Volátiles/química , Antibacterianos/farmacología , Antioxidantes/química , Quitosano/química , Color , Embalaje de Alimentos , Fenómenos Mecánicos , Nisina/química , Aceites Volátiles/farmacología , Fenómenos Ópticos , Pectinas/química , Staphylococcus aureus/efectos de los fármacos , Almidón/química , VaporRESUMEN
Indocyanine green (ICG) is a clinically-approved near infrared (NIR) dye used for optical imaging. The dye is only slightly soluble in water and is prone to aggregation in saline solutions, so that alternative formulations can improve photophysical performance. Numerous nanoscale formulations of ICG have been described in the literature, but we sought to develop an approach that does not require additional purification steps. Pre-formed liposomes incorporating 45 mol% of the cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) rapidly bind ICG, resulting in enhanced NIR optical properties. ICG binding is dependent on the amount of DOTAP incorporated in the liposomes. A dye-to-lipid mass ratio of [0.5 : 25] is sufficient for full complexation, without additional purification steps following mixing. NIR absorption, fluorescence intensity, and photoacoustic signals are increased for the liposome-bound dye. Not only is the optical character enhanced by simple mixing of ICG with liposomes, but retention in 4T1 mammary tumors is observed following intratumor injection, as assessed by fluorescence and photoacoustic imaging. Subsequent photothermal therapy with 808 nm laser irradiation is effective and results in tumor ablation without regrowth for at least 30 days. Thus, ICG optical properties and photothermal ablation outcomes can be improved by mixing the dye with pre-formed DOTAP liposomes in conditions that result in full dye-binding to the liposomes.
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Técnicas de Ablación/métodos , Ácidos Grasos Monoinsaturados/química , Verde de Indocianina/química , Liposomas/química , Neoplasias Mamarias Experimentales/terapia , Fenómenos Ópticos , Compuestos de Amonio Cuaternario/química , Animales , Femenino , Neoplasias Mamarias Experimentales/diagnóstico por imagen , Ratones , Imagen Óptica , FototerapiaRESUMEN
Starch films are gaining attention as substitutes of synthetic polymers due to their biodegradability and low cost. Some ionic liquids have been postulated as alternatives to glycerol, one of the best starch plasticizers, due to their great capacity to form hydrogen bonds with starch and hence great ability of preventing starch retrogradation and increasing film stability. In this work, [emim+][Ac-]-plasticized starch films were prepared from potato, corn and wheat starch. The effect of starch molecular structure in terms of granular composition (amylose and phosphate monoester contents) and molecular weight (Mw) on film properties was evaluated. Potato starch films were the most amorphous because of the higher Mw and phosphate monoester content of potato starch, both contributing to a lower rearrangement of the starch chains making the crystallization process difficult. In contrast, corn and wheat starches lead to more crystalline films because of their lower Mw, which may imply higher mobility and crystal growth rate, and lower phosphate monoester content. This more crystalline structure could be the responsible of their better mechanical properties. [emim+][Ac-] can be considered suitable for manufacturing starch films showing corn and wheat starch films similar properties to synthetic low-density polyethylene, but involving a simple and environmentally-friendly process.