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Resumen del póster presentado al VIII International Congress on Analytical Nanoscience and Nanotechnology, celebrado en Barcelona (España) del 3 al 5 de julio de 2017., Simple, inexpensive and rapid sensing systems are very demanded for a myriad of uses. Intrinsic properties of emerging paper-based analytical devices have demonstrated considerable potential to fulfill such demand. This work reports an easy-to-use, low cost, and disposable paper-based sensing device for rapid chemical screening with a smartphone readout. The device comprises luminescent graphene quantum dots (GQDs) sensing probes embedded into a nitrocellulose matrix where the resonance energy transfer phenomenon seems to be the sensing mechanism. The GQDs probes were synthesized from citric acid by a pyrolysis procedure, further physisorbed and confined into small wax-traced spots on the nitrocellulose substrate. The GQDs were excited by an UV LED, this, is powered by a smartphone used as both; energy source and imaging capture. The LED was contained within a 3D-printed dark chamber that isolates the paper platform from external light fluctuations leading to highly reproducible data. The cellulose-based device was proven as a promising screening tool for phenols and polyphenols in environmental and food samples, respectively. It opens up new opportunities for simple and fast screening of organic compounds and offers numerous possibilities for versatile applications. It can be especially useful in remote settings where sophisticated instrumentation is not always available.

The therapeutic benefits of fruits, vegetables, tea and wine are mostly attributed to the presence of phenolic compounds. Naturally occurring dietary polyphenols, such as curcumin (diferuloylmethane, an active component of spice turmeric) and resveratrol (phytoalexin, a fiavanoid found in red wine) can modulate signaling pathways mediated via NF-κB and MAP kinase, and up-regulate glutathione biosynthesis genes through activation of Nrf2. Polyphenols also down-regulate the expression of pro-inflammatory mediators, matrix metalloproteinases and adhesion molecules by inhibiting histone acetyltransferase (HAT) activity and activating histone deacetylases (HDACs)/sirtuins. It has been reported that in severe asthma and in chronic obstructive pulmonary disease (COPD) patients, oxidative stress not only activates the NF-κB pathway but also alters the histone acetylation and deacetylation balance via post-translational modifications of HDACs. Corticosteroids have been one the major modes of therapy against various respiratory diseases, such as asthma and COPD. Failure of corticosteroids to ameliorate such disease conditions is due to the reduction of HDAC2 and SIRT1 levels/activities in lungs of asthmatics and COPD patients. Dietary polyphenols, such as curcumin, resveratrol, and catechins have been reported to modulate epigenetic alterations in various experimental models. The anti-inflammatory property of curcumin, resveratrol, and catechins is associated with their ability to induce HDAC activity and thereby restore the efficacy of glucocorticoids or overcome its resistance. Thus, these polyphenolic compounds have therapeutic value as antioxidants, anti-inflammatory therapy and adjuvant therapy with steroids against chronic inflammatory and epigenetically-regulated diseases. In this chapter we present the current knowledge on the mode of action of these polyphenols in the light of HDACs.

BACKGROUND: Bagging has been widely used to improve the commercial value of fruit. The purpose of this study was to evaluate the effects of different light transmittance paper bags on the quality and antioxidant capacity of loquat fruit. Two loquat cultivars, Baiyu and Ninghaibai (Eriobotrya japonica Lindl.), were used for materials. One-layered white paper bags (OWPB) with ∼50% light transmittance and two-layered paper bags with a black inner layer and a grey outer layer (TGDPB) with ∼0% light transmittance were used as treatments and unbagged fruits were used as the control (CK) in this experiment. Fruit quality was determined by physicochemical characteristics, the quantity of sugar, total phenolic, flavonoid, carotenoid and vitamin C. The antioxidant capacities of the methanol extracted from the pulp were tested using three different assays. RESULTS: The results showed that bagging decreased the weight of fruit but promoted the appearance of loquat fruits. The total sugar content in the fruit bagged with OWPB was higher than in controls and in fruit bagged with TGDPB. The total phenolic and flavonoid contents were decreased by both bagging treatments, with the lowest occurring in the fruit bagged with TGDPB. Bagging also decreased the total antioxidant capacity of the fruit pulp, which was again lower in TGDPB-treated fruits than in those bagged using OWPB. Correlation analysis showed a linear relationship between total antioxidant capacity and the content of total phenolic and flavonoid. CONCLUSION: The results showed that different light transmittance bags had different effects on fruit quality and antioxidant capacity. In particular, bags with low light transmittance (TGDPB) decreased the inner quality and total antioxidant capacity of loquat fruit. All results indicated that bagging with OWPB was more suitable for maintaining the quality of the loquat fruit than bagging with TGDPB. Copyright © 2010 Society of Chemical Industry

Here we show for the first time that components of pulp and paper mill effluents contain neuroactive substances that may impair fish reproduction. Grab samples of primary and secondary effluent were obtained from a representative pulp and paper mill in Eastern Canada. Effluents were fractionated using classic polarity and polyphenolic extraction methods into solvents of selected polarities (water, ethanol, ethyl acetate, and hexane). By means of in vitro, competitive assays on goldfish (Carassius auratus) brain tissues, the extracts were screened for their ability to interact with enzymes and receptors involved in gamma-aminobutyric acid (GABA), dopamine, glutamate, and acetylcholine-dependent neurotransmission. These neurotransmission pathways have essential regulatory roles in fish reproduction. Radioligand binding to the following neurotransmitter receptors were significantly impacted following in vitro incubations with extracts (percentage change from controls indicated in brackets): dopamine-2 (D2; 21-48% increase), GABA(A) receptor binding (65-67% decrease and 189% increase), N-methyl-o-aspartic acid (NMDA; 26-75% decrease), and muscarinic cholinergic (mACh; 42% increase). Activities of the following neurotransmitter-related enzymeswere significantly impacted: monoamine oxidase (MAO; 14-48% decrease), GABA-transaminase activity (33% decrease and 21-69% increase), and acetylcholinesterase (AChE; 21-50% decrease). No changes in glutamic acid decarboxylase (GAD) activity were detected. These findings provide a novel and plausible mechanism by which pulp and paper mills effluents impair fish reproduction by interacting with neurotransmitter systems. Furtherwork is required to identify the active compounds and explore whether these changes occur in vivo.

The procedure of electrocoagulation is an effective, fast and economic technique for treatment of black liquor resulting from paper industry. The effect of electrolysis time, current density, type of electrode material and initial pH were studied in an attempt to achieve a higher removal capacity. Under the optimal experimental conditions (initial pH 7, t=50 min and J=14 mA cm(-2)), the treatment of black liquor by electrocoagulation has led to a removal capacity of 98% of COD, 92% of polyphenols and 99% of color intensity with a good repeatability (R.S.D.3%) making it possible to highlight the industrial interest of this electrochemical process.