Antioxidant activity of alkyl gallates and glycosyl alkyl gallates in fish oil in water emulsions: Relevance of their surface active properties and of the type of emulsifier

The antioxidant activity of gallic acid and a series of alkyl gallates (C4-C18) and glycosylated alkyl gallates (C4-C18) on fish oil-in-water emulsions was studied. Three types of emulsifiers, lecithin, Tween-20 and sodium dodecyl sulphate (SDS) were tested. A nonlinear behavior of the antioxidant activity of alkyl gallates when increasing alkyl chain length was observed for emulsions prepared with lecithin. Medium-size alkyl gallates (C6-C12) were the best antioxidants. In contrast, for emulsions prepared with Tween-20, the antioxidants seem to follow the polar paradox. Glucosyl alkyl gallates were shown previously to be better surfactants than alkyl gallates. Nevertheless, they exhibited a worse antioxidant capacity than their corresponding alkyl gallates, in emulsions prepared with lecithin or Tween-20, indicating the greater relevance of having three OH groups at the polar head in comparison with having improved surfactant properties but just a di-ortho phenolic structure in the antioxidant

Validation of smart nanoparticles as controlled drug delivery systems: loading and pH-dependent release of pilocarpine

Micelles are good devices for use as controlled drug delivery systems because they exhibit the ability to protect the encapsulated substance from the routes of degradation until they reach the site of action. The present work assesses loading kinetics of a hydrophobic drug, pilocarpine, in polymeric micellar nanoparticles (NPs) and its pH-dependent release in hydrophilic environments. The trigger pH stimulus, pH 5.5, was the value encountered in damaged tissues in solid tumors. The new nanoparticles were prepared from an amphiphilic block copolymer, [(HEMA19%-DMA31%)-(FMA5%-DEA45%)]. For the present research, three systems were validated, two of them with cross-linked cores and the other without chemical stabilization. A comparison of their loading kinetics and release profiles is discussed, with the support of additional data obtained by scanning electron microscopy and dynamic light scattering. The drug was loaded into the NPs within the first minutes; the load was dependent on the degree of cross-linking. All of the systems experienced a boost in drug release at acidic pH, ranging from 50 to 80% within the first 48 h. NPs with the highest degree (20%) of core cross-linking delivered the highest percentage of drug at fixed times. The studied systems exhibited fine-tuned sustained release features, which may provide a continuous delivery of the drug at specific acidic locations, thereby diminishing side effects and increasing therapeutic rates. Hence, the studied NPs proved to behave as smart controlled drug delivery systems capable of responding to changes in pH.Peer ReviewedPostprint (published version

Nanostructured Chitosan-Based Biomaterials for Sustained and Colon-Specific Resveratrol Release

In the present work, we demonstrate the preparation of chitosan-based composites as vehicles of the natural occurring multi-drug resveratrol (RES). Such systems are endowed with potential therapeutic effects on inflammatory bowel diseases (IBD), such as Crohn’s disease (CD) and ulcerative colitis, through the sustained colonic release of RES from long-lasting mucoadhesive drug depots. The loading of RES into nanoparticles (NPs) was optimized regarding two independent variables: RES/polymer ratio, and temperature. Twenty experiments were carried out and a Box–Behnken experimental design was used to evaluate the significance of these independent variables related to encapsulation efficiency (EE). The enhanced RES EE values were achieved in 24 h at 39 °C and at RES/polymer ratio of 0.75:1 w/w. Sizes and polydispersities of the optimized NPs were studied by dynamic light scattering (DLS). Chitosan (CTS) dispersions containing the RES-loaded NPs were ionically gelled with tricarballylic acid to yield CTS-NPs composites. Macro- and microscopic features (morphology and porosity studied by SEM and spreadability), thermal stability (studied by TGA), and release kinetics of the RES-loaded CTS-NPs were investigated. Release patterns in simulated colon conditions for 48 h displayed significant differences between the NPs (final cumulative drug release: 79–81%), and the CTS-NPs composites (29–34%)

Validation of Smart Nanoparticles as Controlled Drug Delivery Systems: Loading and pH-Dependent Release of Pilocarpine

Micelles are good devices for use as controlled drug delivery systems because they exhibit the ability to protect the encapsulated substance from the routes of degradation until they reach the site of action. The present work assesses loading kinetics of a hydrophobic drug, pilocarpine, in polymeric micellar nanoparticles (NPs) and its pH-dependent release in hydrophilic environments. The trigger pH stimulus, pH 5.5, was the value encountered in damaged tissues in solid tumors. The new nanoparticles were prepared from an amphiphilic block copolymer, [(HEMA19%- DMA31%)-(FMA5%-DEA45%)]. For the present research, three systems were validated, two of them with cross-linked cores and the other without chemical stabilization. A comparison of their loading kinetics and release profiles is discussed, with the support of additional data obtained by scanning electron microscopy and dynamic light scattering. The drug was loaded into the NPs within the first minutes; the load was dependent on the degree of cross-linking. All of the systems experienced a boost in drug release at acidic pH, ranging from 50 to 80% within the first 48 h. NPs with the highest degree (20%) of core cross-linking delivered the highest percentage of drug at fixed times. The studied systems exhibited fine-tuned sustained release features, which may provide a continuous delivery of the drug at specific acidic locations, thereby diminishing side effects and increasing therapeutic rates. Hence, the studied NPs proved to behave as smart controlled drug delivery systems capable of responding to changes in pH.Ministerio de Economía y Competitividad de España-MAT2016-77345-C3-2-PJunta de Andalucía-P12-FQM-155

pH-Responsive Polymeric Nanoparticles as Drug Delivery Systems

Micelles are excellent devices to be used as controlled drug delivery systems since they exhibit the ability to protect the drug or encapsulated substance from the routes of degradation until they reach the site of action: moreover, they can pass through biological barriers and reach intracellular compartments. In addition, when a drug is administered and released from the dosage form, the kinetic behavior of the drug depends largely on their chemical structure. However, when the drug is immersed at the core of a NP, the physicochemical properties that actually affect the distribution of the drug in the body are those from the latter. As a result, this approach controls drug release, diminishing side effects and increasing therapeutic rates. In the present work novel smart micelles have been prepared and tested as drug delivery systemsMinisterio de Economía y Competitividad-Grant MAT2016-77345-C3-2-PJunta de Andalucía-Grant P12-FQM-155

Adquisición y procesamiento de imágenes aéreas para sensado remoto

Los sistemas de adquisición de imágenes aéreas digitales de alta resolución basados en cámaras de formato pequeño representan una alternativa de gran versatilidad en la solución de diversos problemas de monitoreo ambiental y sensado remoto, particularmente aquellas obtenidas en base a dispositivos aéreos autónomos UAV. Esto es aí dado que un correcto procesamiento de imágenes de cámaras de formato pequeño (ópticas y/o mulitespectrales) permite la obtención de ortomosaicos que cumplan con estándares de calidad, a una fracción del costo operativo del uso de equipos aerotransportados de costo mucho mayor, y con mayor flexibilidad y resolución que con el uso de imágenes satelitales. El objetivo de este trabajo de investigación es la implementación de un sistema de computo que permita sistematizar la adquisición, procesamiento, rectificación, formación de mosaicos, y georreferenciación de las imágenes adquiridas por medio de cámaras ópticas y multiespectrales transportadas por un UAV. Los resultados obtenidos permiten automatizar el procesamiento casi por completo, requiriendo un mínimo de atención no especializada, y permiten organizar la información e imágenes obtenidas en los vuelos para su posterior uso en procesos de reconocimiento, interpretación e identificación.VII Workshop Computación Gráfica, Imágenes y Visualización (WCGIV)Red de Universidades con Carreras en Informática (RedUNCI

Adquisición y procesamiento de imágenes aéreas para sensado remoto

Los sistemas de adquisición de imágenes aéreas digitales de alta resolución basados en cámaras de formato pequeño representan una alternativa de gran versatilidad en la solución de diversos problemas de monitoreo ambiental y sensado remoto, particularmente aquellas obtenidas en base a dispositivos aéreos autónomos UAV. Esto es aí dado que un correcto procesamiento de imágenes de cámaras de formato pequeño (ópticas y/o mulitespectrales) permite la obtención de ortomosaicos que cumplan con estándares de calidad, a una fracción del costo operativo del uso de equipos aerotransportados de costo mucho mayor, y con mayor flexibilidad y resolución que con el uso de imágenes satelitales. El objetivo de este trabajo de investigación es la implementación de un sistema de computo que permita sistematizar la adquisición, procesamiento, rectificación, formación de mosaicos, y georreferenciación de las imágenes adquiridas por medio de cámaras ópticas y multiespectrales transportadas por un UAV. Los resultados obtenidos permiten automatizar el procesamiento casi por completo, requiriendo un mínimo de atención no especializada, y permiten organizar la información e imágenes obtenidas en los vuelos para su posterior uso en procesos de reconocimiento, interpretación e identificación.VII Workshop Computación Gráfica, Imágenes y Visualización (WCGIV)Red de Universidades con Carreras en Informática (RedUNCI

Aerial image acquisition and processing for remote sensing

UAV (Unmanned Airborne Vehicle) high resolution digital image acquisition systems based on small format cameras provide a versatile alternative to the solution of environmental monitoring and remote sensing problems. Through digital image processing these small format optical and multi-spectral camera images can obtain orthomosaics that meet quality standards at a fraction of the cost of traditional heavier manned vehicle equipment. They also have higher availability, resolution and flexibility can also be obtained when compared to satellite images. This paper presents research and development undertaken to produce a computational system that can automatically process optical and multi-spectral images obtained from digital cameras mounted on a UAV aircraft. The system acquires, rectifies, mosaics and georeferences these images with minimum operator assistance. Results prove that the process can almost be fully automated and that the system can be operated by minimally trained personnel. Processed images obtained by the software can be used for pattern recognition, photo interpretation, photogrammetry, and other remote sensing applications.Facultad de Informátic

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Apolar carbohydrates as DNA capping agents

Mono- and disaccharides have been shown to stack on top of DNA duplexes stabilizing sequences with terminal C–G base pairs. Here we present an apolar version of glucose and cellobiose as new capping agents that stack on DNA increasing considerably its stability with respect to their natural polyhydroxylated mono- and disaccharide DNA conjugates.Ministerio de Ciencia, Innovación y Universidades CTQ2006-01123, CTQ2007-68014- C02-02, CTQ2009-13705, BFU2007-63287Generalitat de Catalunya 2009/SGR/208Instituto de Salud Carlos III CB06_01_001