591 research outputs found

    Solidified floating organic drop microextraction (SFODME) for the simultaneous analysis of three non-steroidal anti-inflammatory drugs in aqueous samples by HPLC

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    In this work, a liquid-liquid microextraction methodology using solidified floating organic drop (SFODME) was combined with liquid chromatography and UV/Vis detection to determine non-steroidal anti-inflammatory drugs (NSAIDs) naproxen (NPX), diclofenac (DCF), and mefenamic acid (MFN) in tap water, surface water, and seawater samples. Parameters that can influence the efficiency of the process were evaluated, such as the type and volume of the extractor and dispersive solvents, effect of pH, agitation type, and ionic strength. The optimized method showed low detection limits (0.09 to 0.25 μg L-1), satisfactory recovery rates (90 to 116%), and enrichment factors in the range between 149 and 199. SFODME showed simplicity, low cost, speed, and high concentration capacity of the analytes under study. Its use in real samples did not demonstrate a matrix effect that would compromise the effectiveness of the method, being possible to apply it successfully in water samples with different characteristics.publishe

    Mito-nuclear sequencing is paramount to correctly identify sympatric hybridizing fishes

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    Background. Hybridization may drive speciation and erode species, especially when intrageneric sympatric species are involved. Five sympatric Luciobarbus species—Luciobarbus sclateri (Günther, 1868), Luciobarbus comizo (Steindachner, 1864), Luciobarbus microcephalus (Almaça, 1967), Luciobarbus guiraonis (Steindachner, 1866), and Luciobarbus steindachneri (Almaça, 1967)—are commonly identified in field surveys by diagnostic morphological characters. Assuming that i) in loco identification is subjective and observer-dependent, ii) there is previous evidence of interspecific hybridization, and iii) the technical reports usually do not include molecular analyses, our main goal was to assess the concordance between in loco species identification based on phenotypic characters with identifications based on morphometric indices, mtDNA only, and a combination of mito-nuclear markers. Materials and methods. Specimens of Luciobarbus from six Guadiana River sub-basins were collected and sequenced for the cytochrome b and beta-actin genes. For comparative purposes, samples of Luciobarbus from other 12 river basins were also used. Four levels of taxonomical identification were conducted based on: identification made in the field (in loco identification), cytb gene only, beta-actin gene only, and mito-nuclear combined genomes. Results. Results showed that interspecific hybridization seems to be high (around 41%) and likely favoured by non-random mating and the loss of fluvial connectivity. About 34% of the hybrids showed mito-nuclear discordance. Misidentifications were frequent when only phenotypic characters are considered, and the use of a single mitochondrial gene is not sufficient: the use of two mito-nuclear markers showed that around 82% of the in loco identifications based on the phenotype were not correct. Conclusion. Incorrect species assignment likely generated biased results in previous studies on the biology and ecology of Guadiana barbels and in the assignment of conservation status and, consequently, on the establishment of conservation management measuresinfo:eu-repo/semantics/publishedVersio

    The mood-improving actions of antidepressants do not depend on neurogenesis but are associated with neuronal remodeling

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    The mechanisms underlying the initiation/onset of, and the recovery from, depression are still largely unknown; views that neurogenesis in the hippocampus may be important for the pathogenesis and amelioration of depressive symptoms have gained currency over the years although the original evidence has been challenged. In this study, an unpredictable chronic mild stress protocol was used to induce a depressive-like phenotype in rats. In the last 2 weeks of stress exposure, animals were treated with the antidepressants fluoxetine, imipramine, CP 156,526 or SSR 1494515, alone or combined with methylazoxymethanol, a cytostatic agent used to arrest neurogenesis. We found that antidepressants retain their therapeutic efficacy in reducing both measured indices of depression-like behavior (learned helplessness and anhedonia), even when neurogenesis is blocked. Instead, our experiments suggest re-establishment of neuronal plasticity (dendritic remodeling and synaptic contacts) in the hippocampus and prefrontal cortex, rather than neurogenesis, as the basis for the restoration of behavioral homeostasis by antidepressants.This project used compound(s) provided by the National Cancer Institute’s Chemical Carcinogen Reference Standards Repository (operated under contract N02-CB-07008 by Midwest Research Institute; MAM), Sanofi-Synthelabo (SSR 149415) and Pfizer (CP 156,526). The authors’ work was supported by the Portuguese Foundation for Science and Technology (FCT) (PTDC/SAU-NEU/72699/2006)

    Should emergence models for Lolium rigidum be changed throughout climatic conditions? The case of Spain

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    Lolium rigidum Gaudin is a troublesome weed worldwide, and its distribution may increase due to climate change. It has become resistant to several herbicides and, therefore, its control is problematic. On the other hand, its seed biology, with little dormancy and short-term viability, can play a major role in reducing its seed bank, which would improve control of this weed. For this reason, knowledge of the emergence patterns of this species entails improvements for its management. In this work seeds from one population of L. rigidum, collected in Northeastern Spain, were distributed and sown in 11 sites across Spain, and its emergence was followed every 2–7 days for two growing seasons (2016-17 and 2017–18). These emergence sequences were compared with previously published thermal time and hydrothermal time based models, and new models were developed afterwards. The hydrothermal time based model did not significantly improve models based solely on thermal time. The accuracy of these newly developed models varied from site to site, but in general, they worked better for Northern locations than for Southern locations. Thus, the experimental sites were split between North and South, and specific models for each region were developed. The model developed for Northern sites worked very well, but the one for Southern sites needs improvement. This works reveals that, with regard to this weed species, probably different models should be developed for different climatic conditions. The model developed with data from Northern sites should be validated with local populations, while the one developed with data from Southern sites will probably need to be revised or newly developed with data from more Southern populations.The group from the University of Lleida-Agrotecnio would also like to thank the Spanish Goverment for partial funding, through project AGL2017-83325-C4-2-R (AEI/FEDER/UE)

    Antinociception induced by chronic glucocorticoid treatment is correlated to local modulation of spinal neurotransmitter content

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    <p>Abstract</p> <p>Background</p> <p>While acute effects of stress on pain are well described, those produced by chronic stress are still a matter of dispute. Previously we demonstrated that chronic unpredictable stress results in antinociception in the tail-flick test, an effect that is mediated by increased levels of corticosteroids. In the present study, we evaluated nociception in rats after chronic treatment with corticosterone (CORT) and dexamethasone (DEX) in order to discriminate the role of each type of corticosteroid receptors in antinociception.</p> <p>Results</p> <p>Both experimental groups exhibited a pronounced antinociceptive effect after three weeks of treatment when compared to controls (CONT); however, at four weeks the pain threshold in CORT-treated animals returned to basal levels whereas in DEX-treated rats antinociception was maintained. In order to assess if these differences are associated with altered expression of neuropeptides involved in nociceptive transmission we evaluated the density of substance P (SP), calcitonin gene-related peptide (CGRP), somatostatin (SS) and <sub>B2</sub>-γ-aminobutiric acid receptors (GABA<sub>B2</sub>) expression in the spinal dorsal horn using light density measurements and stereological techniques. After three weeks of treatment the expression of CGRP in the superficial dorsal horn was significantly decreased in both CORT and DEX groups, while GABA<sub>B2 </sub>was significantly increased; the levels of SP for both experimental groups remained unchanged at this point. At 4 weeks, CGRP and SP are reduced in DEX-treated animals and GABA<sub>B2 </sub>unchanged, but all changes were restored to CONT levels in CORT-treated animals. The expression of SS remained unaltered throughout the experimental period.</p> <p>Conclusion</p> <p>These data indicate that corticosteroids modulate nociception since chronic corticosteroid treatment alters the expression of neuropeptides involved in nociceptive transmission at the spinal cord level. As previously observed in some supraspinal areas, the exclusive GR activation resulted in more profound and sustained behavioural and neurochemical changes, than the one observed with a mixed ligand of corticosteroid receptors. These results might be of relevance for the pharmacological management of certain types of chronic pain, in which corticosteroids are used as adjuvant analgesics.</p

    Towards all-non-vacuum-processed photovoltaic systems: a water-based screen-printed Cu(In,Ga)Se2 Photoabsorber with a 6.6% efficiency

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    During the last few decades, major advances have been made in photovoltaic systems based on Cu(In,Ga)Se2 chalcopyrite. However, the most efficient photovoltaic cells are processed under high-energy-demanding vacuum conditions. To lower the costs and facilitate high-throughput production, printing/coating processes are proving to be effective solutions. This work combined printing, coating, and chemical bath deposition processes of photoabsorber, buffer, and transparent conductive layers for the development of solution-processed photovoltaic systems. Using a sustainable approach, all inks were formulated using water and ethanol as solvents. Screen printing of the photoabsorber on fluorine-doped tin-oxide-coated glass followed by selenization, chemical bath deposition of the cadmium sulfide buffer, and final sputtering of the intrinsic zinc oxide and aluminum-doped zinc oxide top conductive layers delivered a 6.6% maximum efficiency solar cell, a record for screen-printed Cu(In,Ga)Se2 solar cells. On the other hand, the all-non-vacuum-processed device with spray-coated intrinsic zinc-oxide- and tin-doped indium oxide top conductive layers delivered a 2.2% efficiency. The given approaches represent relevant steps towards the fabrication of sustainable and efficient Cu(In,Ga)Se2 solar cells.This study was conducted with financial support from the Portuguese Foundation for Science and Technology (PTDC/CTM-ENE/5387/2014, PTDC/NAN-MAT/28745/2017, UID/FIS/04650/2020, UID/QUI/0686/2020, PTDC/FIS-MAC/28157/2017, SFRH/BD/121780/2016 and SFRH/BD/143750/2019) and the Basque Government Industry Department (ELKARTEK and HAZITEK)

    Efficacy, Stability, and Safety Evaluation of New Polyphenolic Xanthones Towards Identification of Bioactive Compounds to Fight Skin Photoaging

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    Antioxidants have long been used in the cosmetic industry to prevent skin photoaging, which is mediated by oxidative stress, making the search for new antioxidant compounds highly desirable in this field. Naturally occurring xanthones are polyphenolic compounds that can be found in microorganisms, fungi, lichens, and some higher plants. This class of polyphenols has a privileged scaffold that grants them several biological activities. We have previously identified simple oxygenated xanthones as promising antioxidants and disclosed as hit, 1,2-dihydroxyxanthone (1). Herein, we synthesized and studied the potential of xanthones with different polyoxygenated patterns as skin antiphotoaging ingredients. In the DPPH antioxidant assay, two newly synthesized derivatives showed IC₅₀ values in the same range as ascorbic acid. The synthesized xanthones were discovered to be excellent tyrosinase inhibitors and weak to moderate collagenase and elastase inhibitors but no activity was revealed against hyaluronidase. Their metal-chelating effect (FeCl₃ and CuCl₂) as well as their stability at different pH values were characterized to understand their potential to be used as future cosmetic active agents. Among the synthesized polyoxygenated xanthones, 1,2-dihydroxyxanthone (1) was reinforced as the most promising, exhibiting a dual ability to protect the skin against UV damage by combining antioxidant/metal-chelating properties with UV-filter capacity and revealed to be more stable in the pH range that is close to the pH of the skin. Lastly, the phototoxicity of 1,2-dihydroxyxanthone (1) was evaluated in a human keratinocyte cell line and no phototoxicity was observed in the concentration range tested.This research was supported by national funds through FCT, Foundation for Science and Technology, within the scope of UIDB/04423/2020 and UIDP/04423/2020 under the project PTDC/SAU-PUB/28736/2017 (reference POCI-01-0145-FEDER-028736), cofinanced by COMPETE 2020, Portugal 2020 and the European Union through the ERDF and by FCT through national funds, as well as CHIRALBIOACTIVE-PI-3RL-IINFACTS-2019, and supported by the Applied Molecular Biosciences Unit-UCIBIO which is financed by national funds from FCT/MCTES (UID/Multi/04378/2019). Thanks are also due to FCT, the European Union, QREN, FEDER, COMPETE, by funding cE3c center (Ref. UID/BIA/00329/2019) and Direcao Regional da Ciencia e Tecnologia (Azores Government) by funding Azorean Biodiversity Group.info:eu-repo/semantics/publishedVersio

    Over 6% Efficient Cu(In,Ga)Se2 Solar Cell Screen-Printed from Oxides on FTO

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    A new approach to fabricate copper, indium, gallium diselenide (CIGSe) solar cells on conductive fluorine-doped tin oxide (FTO) reached an efficiency of over 6% for a champion photovoltaic device. Commercial oxide nanoparticles are formulated into high-quality screen-printable ink based on ethyl cellulose solution in terpineol. The high homogeneity and good adhesion properties of the oxide ink play an important role in obtaining dense and highly crystalline photoabsorber layers. This finding reveals that solution-based screen-printing from readily available oxide precursors provides an interesting cost-effective alternative to current vacuum- and energy-demanding processes of the CIGSe solar cell fabrication.FCT PTDC/CTM-ENE/5387/2014 (PrintPV), Grant Agreement No. 016663, FCT SFRH/BD/121780/2016. Nanochemistry Research Group at INL for valuable discussions. This work was supported by ERDF COMPETE 2020 and Portuguese FCT funds under the PrintPV project (PTDC/CTM-ENE/5387/2014, Grant Agreement No. 016663). B.F.G. is grateful to the FCT for the SFRH/BD/121780/2016 gran

    The Influence of Emissions from Maritime Transport on Air Quality in the Strait of Gibraltar (Spain)

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    Gaseous and particulate emissions from oceangoing ships have a significant effect on the quality of air in cities. This study estimates mainly the influence of NOx, SOx, and particulate matter (PM2.5) on air quality in the Strait of Gibraltar (Spain) using the authors' own Ship's Energy and Emissions Model (SENEM) and the California Puff air quality model (CALPUFF) in 2017. The Algeciras Bay Industrial Zone recorded the highest levels of pollutants, and the Palmones area was identified as a major hotspot, with mean daily ship-sourced SOx concentrations >215 mu g/m(3), while the highest concentrations of PM10 reached 8.5 mu g/m(3) inside the Strait, and the mean yearly contribution of PM2.5 reached 0.86 mu g/m(3) in the city of Algeciras. The incidence of maritime traffic emissions on the levels of particle emissions, CO, HC, NMVOC, and CO2 reached values of up to 20-25% in all the receivers defined in the study
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