688 research outputs found

    A new subspecies of Orthotylus junipericola Linnavuori, 1965 (Insecta, Heteroptera) from the Azores.

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    Orthotylus (Parapachylops) junipericola attilioi n.ssp. is described from Terceira (Azores), based on a single male specimen collected in the Azorean endemic tree Juniperus brevifolia. O. (Parapachylops) junipericola Linnavuori, 1965 is a “Rassenkreis” with seven known geographic races with an Atlanto-mediterranean distribution. O. (Parapachylops) junipericola attilioi n.ssp. is the eighth subspecies described from this species, being the most occidental taxon. The new subspecies, O. (Parapachylops) junipericola attilioi n.ssp., was sampled in a biodiversity hotspot from the Azores, Biscoito da Ferraria Natural Forest Reserve of “climax pattern of indigenous forest”

    Width of Sunspot Generating Zone and Reconstruction of Butterfly Diagram

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    Based on the extended Greenwich-NOAA/USAF catalogue of sunspot groups it is demonstrated that the parameters describing the latitudinal width of the sunspot generating zone (SGZ) are closely related to the current level of solar activity, and the growth of the activity leads to the expansion of SGZ. The ratio of the sunspot number to the width of SGZ shows saturation at a certain level of the sunspot number, and above this level the increase of the activity takes place mostly due to the expansion of SGZ. It is shown that the mean latitudes of sunspots can be reconstructed from the amplitudes of solar activity. Using the obtained relations and the group sunspot numbers by Hoyt and Schatten (1998), the latitude distribution of sunspot groups ("the Maunder butterfly diagram") for the 18th and the first half of the 19th centuries is reconstructed and compared with historical sunspot observations.Comment: 16 pages, 11 figures; accepted by Solar Physics; the final publication will be available at www.springerlink.co

    Influence of chitin nanocrystals on the dielectric behaviour and conductivity of chitosan-based bionanocomposites

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    A series of bionanocomposite films based on chitosan, reinforced with chitin nanocrystals, were developed, and assessed in terms of dielectric behaviour and conductivity by using an experimental methodology that allows avoiding the conductivity contribution and the exclusion of contact and interfacial polarization effects. The dielectric relaxations at low and high frequency and temperatures were modeled by Havriliak-Negami functions. Below the glass transition temperature (Tg), the Îł and ÎČ relaxations were observed, which were related to intramolecular and non-cooperative segmental movements. At higher temperatures, an intermolecular and cooperative macromolecular movement, related to the glass transition, gave rise to α-relaxation. In addition, two over-Tg ρI and ρII relaxations were found, which were related to the displacement of dipoles in the disordered structure of bionanocomposites. The addition of chitin nanocrystals did not affect the apparent activation energy Ea of the Îł-relaxation. However, it decreased the Ea of the ÎČ-relaxation and increased the free volume at temperatures in the vicinities of the α-relaxation. Finally, the electric conductivity of the bionanocomposites was lower than that of neat chitosan and chitin due to the interaction between the OH and NH2 groups that reduced the ionic mobility, along with the increase of free volume, with the subsequent separation of phases

    Molecular Mobility in Oriented and Unoriented Membranes Based on Poly[2-(Aziridin-1-yl)ethanol]

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    Unoriented and oriented membranes based on dendronized polymers and copolymers obtained by chemical modification of poly[2-(aziridin-1-yl) ethanol] (PAZE) with the dendron 3,4,5-tris[4-(n-dodecan-1-yloxy)benzyloxy]benzoate were considered. DSC, XRD, CP-MAS NMR and DETA, contribute to characterize the tendency to crystallize, the molecular mobility of the benzyloxy substituent, the dendritic liquid crystalline group and the clearing transition. The orientation of the mesogenic chain somewhat hindered this molecular motion, especially in the full substituted PAZE. The fragility, free volume and thermal expansion coefficients of these membranes near the glass transition are related to the orientation and the addition of the dendritic groups. PAZE-based membranes combine both order and mobility on a supramolecular and macroscopic level, controlled by the dendritic group and the thermal orientation, and open the possibility of preparing membranes with proper channel mobility that promotes selective ionic transport

    Liver X receptor inhibition potentiates mitotane induced adrenotoxicity in ACC

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    Adrenocortical carcinoma (ACC) is a rare aggressive malignancy with a poor outcome largely due to limited treatment options. Here, we propose a novel therapeutic approach through modulating intracellular free cholesterol via the liver X receptor alpha (LXRα) in combination with current first line pharmacotherapy, mitotane. H295R and MUC-1 ACC cell lines were pretreated with LXRα inhibitors in combination with mitotane. In H295R, mitotane (20, 40, 50”M) induced dose-dependent cell death, however, in MUC-1 this only occurred at a supratherapeutic concentration (200”M). LXRα inhibition potentiated mitotane-induced cytotoxicity in both cell lines. This was confirmed through use of the CompuSyn model which showed moderate pharmacological synergism and was indicative of apoptotic cell death via an increase in annexinV and cleaved-caspase 3 expression. Inhibition of LXRα was confirmed through downregulation of cholesterol efflux pumps ABCA1 and ABCG1, however, combination treatment with mitotane attenuated this effect. Intracellular free cholesterol levels were associated with increased cytotoxicity in H295R (r2=0.5210) and MUC-1 (r2=0.9299) cells. While both cell lines exhibited similar levels of free cholesterol at baseline, H295R were cholesterol ester rich whereas MUC-1 were cholesterol ester poor. We highlight the importance of LXRα mediated cholesterol metabolism in the management of ACC, drawing attention to its role in the therapeutics of mitotane sensitive tumours. We also demonstrate significant differences in cholesterol storage between mitotane sensitive and resistant disease.</jats:p

    Poly (lactic acid)/D-limonene/ZnO bio-nanocomposites with antimicrobial properties

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    Antimicrobial films of poly (lactic acid) (PLA)/D-limonene/zinc oxide (ZnO)-based bio-nanocomposites were prepared via melt compounding and subsequent thermocompression. D-limonene was incorporated at concentrations of 10 or 20 wt%, and ZnO pure nanoparticles and those organically modified with oleic acid (O-ZnO), with an average diameter of 13.5 nm, were included at concentrations of 3, 5, and 8 wt%. The plasticizing effect of D-Limonene was corroborated by a decrease in the glass transition temperature compared to pure PLA. The presence of ZnO and O-ZnO in the PLA matrix promoted a slight increase in the degree of crystallinity due to its nucleant performance. Although ZnO and O-ZnO induced lower thermal stability and slightly decreased microhardness in the composites, excellent antimicrobial performance was demonstrated. Both ZnO and O-ZnO nanocomposites reached 99.9% of effectiveness for nanoparticles content above 5 wt%, regardless of the source of irradiation, D-limonene concentration, and nanoparticle modification. Therefore, these bio-nanocomposites will allow for future advances in sustainable antimicrobial materials for the medical or food packaging fields.DICYT, Grant/Award Number: Project 022041ZR_POSTDOCT; Fondo Nacional de Desarrollo Científico y Tecnológico,Grant/Award Numbers: 1170226, 320029

    EficiĂȘncia energĂ©tica do processo top-down na produção de nanofibrilas de celulose.

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    O presente estudo tem por objetivo produzir nanofibrilas de celulose vegetal com polpa kraft marrom por meio de prĂ©-tratamento enzimĂĄtico e posteriormente mecĂąnico, com o intuito de redução no consumo energĂ©tico. Para isso, as amostras de polpas de celulose foram previamente desestruturadas atravĂ©s da saturação em ĂĄgua e desmembradas em um desfibrador mecĂąnico. ApĂłs, armazenadas sob refrigeração a 5°C. Para o prĂ©-tratamento enzimĂĄtico utilizou-se a enzima comercial Cellic Ctec-2, em porcentagens que variaram de 0,01 a 0,1% por meio de hidrĂłlise controlada com pH neutro e temperatura ambiente durante uma hora, sendo que as amostras com quantidade de 0,01% sofreram hidrĂłlise por diferentes perĂ­odos (1 e 2 horas). ApĂłs o tempo de hidrĂłlise, a polpa foi processada em um moinho de discos, o qual possui medidor de energia. As polpas sofreram passagens em ciclos pelo moinho, atĂ© o ponto de se transformarem em um gel viscoso. Para estacionar a ação enzimĂĄtica o conteĂșdo foi aquecido Ă  85°C. Os gĂ©is foram armazenados em resfriamento de 5°C. O processo foi caracterizado pelo gasto energĂ©tico medido a cada amostra com suas testemunhas, alĂ©m de ser medido o rendimento de cada gel produzido. De acordo com os resultados, foi observado que o processo combinado apresentou-se viĂĄvel para a produção de nanofibrilas, pois este, diminui o tempo e gasto energĂ©tico do processo. A polpa marrom mesmo sem ter passado por processos de deslignificação, mostrou-se promissora na produção das nanofibrilas de celulose vegetal

    Association between faecal pH and fat absorption in children with cystic fibrosis on a controlled diet and enzyme supplements dose

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    [EN] Background Despite treatment with pancreatic enzyme replacement therapy (PERT), patients with cystic fibrosis (CF) can still suffer from fat malabsorption. A cause could be low intestinal pH disabling PERT. The aim of this study was to assess the association between faecal pH (as intestinal pH surrogate) and coefficient of fat absorption (CFA). Additionally, faecal free fatty acids (FFAs) were quantified to determine the amount of digested, but unabsorbed fat. Methods In a 24-h pilot study, CF patients followed a standardised diet with fixed PERT doses, corresponding to theoretical optimal doses determined by an in vitro digestion model. Study variables were faecal pH, fat and FFA excretion, CFA and transit time. Linear mixed regression models were applied to explore associations. Results In 43 patients, median (1st, 3rd quartile) faecal pH and CFA were 6.1% (5.8, 6.4) and 90% (84, 94), and they were positively associated (p < 0.001). An inverse relationship was found between faecal pH and total fat excretion (p < 0.01), as well as total FFA (p = 0.048). Higher faecal pH was associated with longer intestinal transit time (p = 0.049) and the use of proton pump inhibitors (p = 0.009). Conclusions Although the clinical significance of faecal pH is not fully defined, its usefulness as a surrogate biomarker for intestinal pH should be further explored. Impact Faecal pH is a physiological parameter that may be related to intestinal pH and may provide important physiopathological information on CF-related pancreatic insufficiency. Faecal pH is correlated with fat absorption, and this may explain why pancreatic enzyme replacement therapy is not effective in all patients with malabsorption related to CF. Use of proton pump inhibitors is associated to higher values of faecal pH. Faecal pH could be used as a surrogate biomarker to routinely monitor the efficacy of pancreatic enzyme replacement therapy in clinical practice. Strategies to increase intestinal pH in children with cystic fibrosis should be targeted.We acknowledge the support of the MyCyFAPP Project consortium. We especially thank the participation and the effort of the patients involved in the study and their families. This work was fully funded by the European Union and the Horizon 2020 Research and Innovation Framework Programme (PHC-26-2014 call Self management of health and disease: citizen engagement and mHealth) under grant number 643806.Calvo-Lerma, J.; Roca-Llorens, M.; Boon, M.; Colombo, C.; De Koning, B.; FornĂ©s-Ferrer, V.; Masip, E.... (2021). Association between faecal pH and fat absorption in children with cystic fibrosis on a controlled diet and enzyme supplements dose. Pediatric Research. 89(1):205-210. https://doi.org/10.1038/s41390-020-0860-3S205210891Turck, D. et al. ESPEN-ESPGHAN-ECFS guidelines on nutrition care for infants, children, and adults with cystic fibrosis. Clin. Nutr. 35, 557–577 (2016).Borowitz, D., Baker, R. 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    Application of whey of Mozzarella di Bufala Campana fermented by lactic acid bacteria as a bread biopreservative agent

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    A total of nine isolated lactic acid bacteria (LAB) from tomato and sourdough with antifungal activity were employed to revaluate the whey of Mozzarella di Bufala through the fermentation process for 72 h at 37 °C. Then, the fermented whey (BWF) was characterised and used as biopreservative in bread formulation. L. plantarum TR7 and L. plantarum TR2 strains showed average lactic acid concentration in BWF of 13.8 g L 1. Also, the bread volatile organic compounds (VOC) analysis showed an increase in hexanal, benzeneacetaldehyde, benzaldehyde and pyrazine tetramethyl when using BWF as ingredient. Moreover, the DPPH-inhibitory activity of bread with BWF extract also reflected a 33% rise in comparison with control bread. The application of BWF as a biopreservation agent in bread showed an increase in shelf life compared with bread with 0.3% calcium propionate and bread control for 2 and 15 days, respectively. BWF can be used as an interesting biopreservation strategy of bread
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