Low molecular weight ϵ-caprolactone-pcoumaric acid copolymers as potential biomaterials for skin regeneration applications

ϵ-caprolactone-p-coumaric acid copolymers at different mole ratios (ϵ-caprolactone:p-coumaric acid 1:0, 10:1, 8:1, 6:1, 4:1, and 2:1) were synthesized by melt-polycondensation and using 4-dodecylbenzene sulfonic acid as catalyst. Chemical analysis by NMR and GPC showed that copolyesters were formed with decreasing molecular weight as p-coumaric acid content was increased. Physical characteristics, such as thermal and mechanical properties, as well as water uptake and water permeability, depended on the mole fraction of pcoumaric acid. The p-coumarate repetitive units increased the antioxidant capacity of the copolymers, showing antibacterial activity against the common pathogen Escherichia coli. In addition, all the synthesized copolyesters, except the one with the highest concentration of the phenolic acid, were cytocompatible and hemocompatible, thus becoming potentially useful for skin regeneration applications

Flavonoid and Capsaicinoid Contents and Consumption of Mexican Chili Pepper (Capsicum annuum L.) Landraces

There is insufficient evidence to identify the precise health effects of chili pepper consumption. However, there is evidence of their topical use as an analgesic to decrease pain from rheumatoid arthritis, osteoarthritis, neuralgias, neuropathic diabetes, neuronal dysfunctions and inflammation, among others. In this work, the diversity and variety of consumed forms of chilis in Mexico, flavonoid and capsaicinoid content in fruits, and their potential health uses are documented, based on various research results and bibliographic information. In Mexico, more than 150 landraces of wild and cultivated origins are consumed and preserved and are distributed throughout the country; the greatest diversity is concentrated in the central and south-southeastern regions. Consumption per capita in urban households is from 8 to 9 kg, and in rural communities, it varies from 14 to 17 kg. Chili peppers contain up to 23 flavonoids and 20 capsaicinoids, differing among landraces because of crop management, maturation of fruits, postharvest management and ecological-environmental influences. Flavonoids and capsaicinoids confer antioxidant, anticarcinogenic properties on the fruit and have lipolytic and preventative effects on chronic degenerative diseases. However, in vitro and in vivo experimental trials of capsaicinoids and flavonoids with beneficial effects must be conducted with regard to human health

Graphene and polytetrafluoroethylene synergistically improve the tribological properties and adhesion of nylon 66 coatings

Abstract In this work, we exploit the bidimensional structure and high stiffness of graphene to improve the tribological response of nylon-based composites. Graphene nanoplatelets, coupled with polytetrafluoroethylene microparticles, synergistically improve the friction coefficient and wear rate, as well as the adhesion to the substrate. The enhancement, as high as threefold for both friction and wear rate at the optimal graphene concentration (0.5% in weight), depends upon the formation of a continuous, robust transfer film with the steel rubbing counterpart, as shown by Raman measurements. The graphene-nylon coating also shows three-fold improved adhesion to the underlying substrate, attributed to the high surface energy of graphene

Chemical characteristics and colorimetric properties of non-centrifugal cane sugar (“panela”) obtained via different processing technologies

Non-centrifugal cane sugar (NCS) samples obtained by traditional moulding and granulation, and also via a novel spray-drying powdering process without additives, were assessed to characterise their sugar and phenolic profiles, flavonoid content, as well as colour parameters. As expected, sucrose was the predominant sugar (91.9–95.5%), followed by glucose (2.9–4.6%), and fructose (1.6–3.7%). Total phenolic content was between 0.4 and 0.6% and total flavonoid content into the range of 0.2–0.4%. Six phenolic acids were found in all NCS samples: protocatechuic acid (0.36–0.94 µg/100 g), vanillic acid (0.70–1.45 µg/100 g), chlorogenic acid (2.08–3.82 µg/100 g), syringic acid (1.08–2.80 µg/100 g), p-coumaric acid (0.69–1.35 µg/100 g), and ferulic acid (0.50–0.95 µg/100 g). The thermal treatment under high temperatures required in the production of granulated products was related with darker colours and changes in phenol and flavonoid contents. In contrast, spray drying generates clearer products, but with slightly less phenol and flavonoid contents.Universidad. Nacional de Colombia-DIEB - HERMES 4216

Molecular phylogeny of atractus (Serpentes, dipsadidae), with emphasis on Ecuadorian species and the description of three new taxa

Volume: 661Start Page: 91End Page: 12

Nuevo colorante orgánico para aplicación en celdas solares de sensibilización espectral

En este trabajo se caracterizó un nuevo material orgánico: 2,2´-dicianoacético-7,7´-bisdifenilamino-9,9´-spirobisfuoreno (SSD1), el cual tiene por finalidad reemplazar los complejos derivados de Rutenio, utilizados en celdas solares sensibilizadas espectralmente. Esta estructura posee un grupo spirobisfluoreno como centro estructural, el cual es sustituido con grupos donores (D) (Trifenilamina) y grupos aceptores (A) de electrones (ciano y carboxilo). Se evaluó la eficiencia de conversión de energía de los dispositivos construidos con depósitos de nanopartículas de TiO2 sensibilizadas con SSD1 y utilizando la cupla Γ/Γ3 como mediador redox. Las celdas exhibieron una corriente de cortocircuito (Jcc) de 8.9 mA/cm2, un voltaje de circuito abierto (Voc) de 0.61 V, y un Factor de llenado (FF) de 0.67, lo cual determina una eficiencia (η) de 3.75%.A new dye, SSD1, featuring two donor/acceptor chromophores aligned in a spiro configuration with two anchoring group separated at a distance of 10.05 Å (closely matching the distance between the adsorption sites of the anatase TiO2 surface), that undergoes efficient dye adherence on TiO2 films. A dye-sensitized solar cell incorporating SSD1 exhibited a short-circuit current of 8.9 mA cm–2, an open-circuit voltage of 0.63 V, a fill factor of 0.67, and a power conversion efficiency of 3.75%.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Nuevo colorante orgánico para aplicación en celdas solares de sensibilización espectral

En este trabajo se caracterizó un nuevo material orgánico: 2,2´-dicianoacético-7,7´-bisdifenilamino-9,9´-spirobisfuoreno (SSD1), el cual tiene por finalidad reemplazar los complejos derivados de Rutenio, utilizados en celdas solares sensibilizadas espectralmente. Esta estructura posee un grupo spirobisfluoreno como centro estructural, el cual es sustituido con grupos donores (D) (Trifenilamina) y grupos aceptores (A) de electrones (ciano y carboxilo). Se evaluó la eficiencia de conversión de energía de los dispositivos construidos con depósitos de nanopartículas de TiO2 sensibilizadas con SSD1 y utilizando la cupla Γ/Γ3 como mediador redox. Las celdas exhibieron una corriente de cortocircuito (Jcc) de 8.9 mA/cm2, un voltaje de circuito abierto (Voc) de 0.61 V, y un Factor de llenado (FF) de 0.67, lo cual determina una eficiencia (η) de 3.75%.A new dye, SSD1, featuring two donor/acceptor chromophores aligned in a spiro configuration with two anchoring group separated at a distance of 10.05 Å (closely matching the distance between the adsorption sites of the anatase TiO2 surface), that undergoes efficient dye adherence on TiO2 films. A dye-sensitized solar cell incorporating SSD1 exhibited a short-circuit current of 8.9 mA cm–2, an open-circuit voltage of 0.63 V, a fill factor of 0.67, and a power conversion efficiency of 3.75%.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Nuevo colorante orgánico para aplicación en celdas solares de sensibilización espectral

En este trabajo se caracterizó un nuevo material orgánico: 2,2´-dicianoacético-7,7´-bisdifenilamino-9,9´-spirobisfuoreno (SSD1), el cual tiene por finalidad reemplazar los complejos derivados de Rutenio, utilizados en celdas solares sensibilizadas espectralmente. Esta estructura posee un grupo spirobisfluoreno como centro estructural, el cual es sustituido con grupos donores (D) (Trifenilamina) y grupos aceptores (A) de electrones (ciano y carboxilo). Se evaluó la eficiencia de conversión de energía de los dispositivos construidos con depósitos de nanopartículas de TiO2 sensibilizadas con SSD1 y utilizando la cupla Γ/Γ3 como mediador redox. Las celdas exhibieron una corriente de cortocircuito (Jcc) de 8.9 mA/cm2, un voltaje de circuito abierto (Voc) de 0.61 V, y un Factor de llenado (FF) de 0.67, lo cual determina una eficiencia (η) de 3.75%.A new dye, SSD1, featuring two donor/acceptor chromophores aligned in a spiro configuration with two anchoring group separated at a distance of 10.05 Å (closely matching the distance between the adsorption sites of the anatase TiO2 surface), that undergoes efficient dye adherence on TiO2 films. A dye-sensitized solar cell incorporating SSD1 exhibited a short-circuit current of 8.9 mA cm–2, an open-circuit voltage of 0.63 V, a fill factor of 0.67, and a power conversion efficiency of 3.75%.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Developmental Changes in Dynamic Functional Connectivity From Childhood Into Adolescence

The longitudinal study of typical neurodevelopment is key for understanding deviations due to specific factors, such as psychopathology. However, research utilizing repeated measurements remains scarce. Resting-state functional magnetic resonance imaging (MRI) studies have traditionally examined connectivity as ‘static’ during the measurement period. In contrast, dynamic approaches offer a more comprehensive representation of functional connectivity by allowing for different connectivity configurations (time varying connectivity) throughout the scanning session. Our objective was to characterize the longitudinal developmental changes in dynamic functional connectivity in a population-based pediatric sample. Resting-state MRI data were acquired at the ages of 10 (range 8-to-12, n = 3,327) and 14 (range 13-to-15, n = 2,404) years old using a single, study-dedicated 3 Tesla scanner. A fully-automated spatially constrained group-independent component analysis (ICA) was applied to decompose multi-subject resting-state data into functionally homogeneous regions. Dynamic functional network connectivity (FNC) between all ICA time courses were computed using a tapered sliding window approach. We used a k-means algorithm to cluster the resulting dynamic FNC windows from each scan session into five dynamic states. We examined age and sex associations using linear mixed-effects models. First, independent from the dynamic states, we found a general increase in the temporal variability of the connections between intrinsic connectivity networks with increasing age. Second, when examining the clusters of dynamic FNC windows, we observed that the time spent in less modularized states, with low intra- and inter-network connectivity, decreased with age. Third, the number of transitions between states also decreased with age. Finally, compared to boys, girls showed a more mature pattern of dynamic brain connectivity, indicated by more time spent in a highly modularized state, less time spent in specific states that are frequently observed at a younger age, and a lower number of transitions between states. This longitudinal population-based study demonstrates age-related maturation in dynamic intrinsic neural activity from childhood into adolescence and offers a meaningful baseline for comparison with deviations from typical development. Given that several behavioral and cognitive processes also show marked changes through childhood and adolescence, dynamic functional connectivity should also be explored as a potential neurobiological determinant of such changes

A new glassfrog (Centrolenidae) from the Chocó-Andean Río Manduriacu Reserve, Ecuador, endangered by mining

We describe a new glassfrog from Río Manduriacu Reserve, Imbabura Province, on the Pacific slopes of the Ecuadorian Andes. The new species can be distinguished from most other glassfrogs by having numerous yellow spots on the dorsum and lacking membranes among fingers. Both morphological and molecular data support the placement of the species in the genus Nymphargus. We present a new mitochondrial phylogeny of Nymphargus and discuss the speciation patterns of this genus; most importantly, recent speciation events seem to result from the effect of the linearity of the Andes. Finally, although the new species occurs within a private reserve, it is seriously endangered by mining activities; thus, following IUCN criteria, we consider the new species as Critically Endangered