23 research outputs found

    Thickness Effect on F8T2/C 60

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    Copolymers based on fluorene-thiophene units have presented promising efficiencies in photovoltaic devices applications. They present good transport properties mainly after thermal treatment of the polymer films. Here, we investigate the properties of bilayer devices formed by the heterojunction of the polymer F8T2 with variable thickness and the fullerene. The series resistance of the equivalent circuit associated with the device increases as the polymer film gets thicker. The current-voltage characteristics of the bilayer devices follow the Mott-Gurney law of SCLC. For the best performing device we measured 2.1% of power conversion efficiency

    The steroid-hormone ecdysone coordinates parallel pupariation neuromotor and morphogenetic subprograms via epidermis-to-neuron Dilp8-Lgr3 signal induction

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    Funding Information: We thank Drs. Carlos Ribeiro, Christen Mirth, Elio Sucena, Filip Port, Frank Schnorrer, Julien Colombani, Maria Dominguez, Maria Luisa Vasconcelos, Pierre Leopold, Simon Bullock, Rita Teodoro, Gerald Rubin, Melissa Harrison, Kate O’Connor-Giles, Jill Wildonger, Mariana Melani, Pablo Wappner, and Christian Wegener for fly stocks and reagents. We thank Ryohei Yagi and Konrad Basler for the LHV2 plasmid and Brain McCabe for the mhc-Gateway destination plasmid. We thank Carlos Ribeiro and Dennis Goldschmidt for help in designing and constructing one of the pupariation arenas and Mariana Melani, Pablo Wappner, Arash Bashirullah, and Filip Port for sharing resources and unpublished data. We thank Arash Bashirullah, Fillip Port, and Carlos Ribeiro for discussions and/or comments on the manuscript, and Jim Truman for discussions on Fraenkel’s pupariation factors. Stocks obtained from the Bloomington Drosophila Stock Center (NIH P40OD018537) were used in this study. Work in the Integrative Biomedicine Laboratory was supported by the European Commission FP7 (PCIG13-GA-2013-618847), by the FCT (IF/00022/2012; Congento LISBOA-01-0145-FEDER-022170, cofinanced by FCT/Lisboa2020; UID/Multi/04462/2019; PTDC/BEXBCM/1370/2014; PTDC/MED-NEU/30753/2017; PTDC/BIA-BID/31071/2017; FCT SFRH/BPD/94112/ 2013; SFRH/BD/94931/2013), the MIT Portugal Program (MIT-EXPL/BIO/0097/2017), and FAPESP (16/09659-3, 16/10342-4, and 17/17904-0). AG is a CONICET researcher, YV holds a CONICET postdoctoral fellowship and FPS and MJD hold a PhD fellowship from CONICET. Work in the Garelli lab was supported by ANPCyT (Agencia Nacional para la Promoción de la Ciencia y la Tecnología, PICT 2014-2900 and PICT 2017-0254) and CONICET (PIP11220150100182CO). Publisher Copyright: © 2021, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved.Innate behaviors consist of a succession of genetically-hardwired motor and physiological subprograms that can be coupled to drastic morphogenetic changes. How these integrative responses are orchestrated is not completely understood. Here, we provide insight into these mechanisms by studying pupariation, a multi-step innate behavior of Drosophila larvae that is critical for survival during metamorphosis. We find that the steroid-hormone ecdysone triggers parallel pupariation neuromotor and morphogenetic subprograms, which include the induction of the relaxin-peptide hormone, Dilp8, in the epidermis. Dilp8 acts on six Lgr3-positive thoracic interneurons to couple both subprograms in time and to instruct neuromotor subprogram switching during behavior. Our work reveals that interorgan feedback gates progression between subunits of an innate behavior and points to an ancestral neuromodulatory function of relaxin signaling.publishersversionpublishe

    Seven-coordinate Tb3+ complexes with 90% quantum yields: High-performance examples of combined singlet- and triplet-to-Tb3+ energy-transfer pathways

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    Seven-coordinate, pentagonal-bipyramidal (PBP) complexes [Ln(bbpen)Cl] and [Ln(bbppn)Cl], in which Ln = Tb3+ (products I and II), Eu3+ (III and IV), and Gd3+ (V and VI), with bbpen2- = N,N′-bis(2-oxidobenzyl)-N,N′-bis(pyridin-2-ylmethyl)ethylenediamine and bbppn2- = N,N′-bis(2-oxidobenzyl)-N,N′-bis(pyridin-2-ylmethyl)-1,2-propanediamine, were synthesized and characterized by single-crystal X-ray diffraction analysis, alternating-current magnetic susceptibility measurements, and photoluminescence (steady-state and time-resolved) spectroscopy. Under a static magnetic field of 0.1 T, the Tb3+ complexes I and II revealed single-ion-magnet behavior. Also, upon excitation at 320 nm at 300 K, I and II presented very high absolute emission quantum yields (0.90 ± 0.09 and 0.92 ± 0.09, respectively), while the corresponding Eu3+ complexes III and IV showed no photoluminescence. Detailed theoretical calculations on the intramolecular energy-transfer rates for the Tb3+ products indicated that both singlet and triplet ligand excited states contribute efficiently to the overall emission performance. The expressive quantum yields, QLnL, measured for I and II in the solid state and a dichloromethane solution depend on the excitation wavelength, being higher at 320 nm. Such a dependence was rationalized by computing the intersystem crossing rates (WISC) and singlet fluorescence lifetimes (τS) related to the population dynamics of the S1 and T1 levels. Thin films of product II showed high air stability and photostability upon continuous UV illumination, which allowed their use as downshifting layers in a green light-emitting device (LED). The prototypes presented a luminous efficacy comparable with those found in commercial LED coatings, without requiring encapsulation or dispersion of II in host matrixes. The results indicate that the PBP environment determined by the ethylenediamine (en)-based ligands investigated in this work favors the outstanding optical properties in Tb3+ complexes. This work presents a comprehensive structural, chemical, and spectroscopic characterization of two Tb3+ complexes of mixed-donor, en-based ligands, focusing on their outstanding optical properties. They constitute good molecular examples in which both triplet and singlet excited states provide energy to the Tb3+ ion and lead to high values of QLnL

    Diretriz sobre Diagnóstico e Tratamento da Cardiomiopatia Hipertrófica – 2024

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    Hypertrophic cardiomyopathy (HCM) is a form of genetically caused heart muscle disease, characterized by the thickening of the ventricular walls. Diagnosis requires detection through imaging methods (Echocardiogram or Cardiac Magnetic Resonance) showing any segment of the left ventricular wall with a thickness > 15 mm, without any other probable cause. Genetic analysis allows the identification of mutations in genes encoding different structures of the sarcomere responsible for the development of HCM in about 60% of cases, enabling screening of family members and genetic counseling, as an important part of patient and family management. Several concepts about HCM have recently been reviewed, including its prevalence of 1 in 250 individuals, hence not a rare but rather underdiagnosed disease. The vast majority of patients are asymptomatic. In symptomatic cases, obstruction of the left ventricular outflow tract (LVOT) is the primary disorder responsible for symptoms, and its presence should be investigated in all cases. In those where resting echocardiogram or Valsalva maneuver does not detect significant intraventricular gradient (> 30 mmHg), they should undergo stress echocardiography to detect LVOT obstruction. Patients with limiting symptoms and severe LVOT obstruction, refractory to beta-blockers and verapamil, should receive septal reduction therapies or use new drugs inhibiting cardiac myosin. Finally, appropriately identified patients at increased risk of sudden death may receive prophylactic measure with implantable cardioverter-defibrillator (ICD) implantation.La miocardiopatía hipertrófica (MCH) es una forma de enfermedad cardíaca de origen genético, caracterizada por el engrosamiento de las paredes ventriculares. El diagnóstico requiere la detección mediante métodos de imagen (Ecocardiograma o Resonancia Magnética Cardíaca) que muestren algún segmento de la pared ventricular izquierda con un grosor > 15 mm, sin otra causa probable. El análisis genético permite identificar mutaciones en genes que codifican diferentes estructuras del sarcómero responsables del desarrollo de la MCH en aproximadamente el 60% de los casos, lo que permite el tamizaje de familiares y el asesoramiento genético, como parte importante del manejo de pacientes y familiares. Varios conceptos sobre la MCH han sido revisados recientemente, incluida su prevalencia de 1 entre 250 individuos, por lo tanto, no es una enfermedad rara, sino subdiagnosticada. La gran mayoría de los pacientes son asintomáticos. En los casos sintomáticos, la obstrucción del tracto de salida ventricular izquierdo (TSVI) es el trastorno principal responsable de los síntomas, y su presencia debe investigarse en todos los casos. En aquellos en los que el ecocardiograma en reposo o la maniobra de Valsalva no detecta un gradiente intraventricular significativo (> 30 mmHg), deben someterse a ecocardiografía de esfuerzo para detectar la obstrucción del TSVI. Los pacientes con síntomas limitantes y obstrucción grave del TSVI, refractarios al uso de betabloqueantes y verapamilo, deben recibir terapias de reducción septal o usar nuevos medicamentos inhibidores de la miosina cardíaca. Finalmente, los pacientes adecuadamente identificados con un riesgo aumentado de muerte súbita pueden recibir medidas profilácticas con el implante de un cardioversor-desfibrilador implantable (CDI).A cardiomiopatia hipertrófica (CMH) é uma forma de doença do músculo cardíaco de causa genética, caracterizada pela hipertrofia das paredes ventriculares. O diagnóstico requer detecção por métodos de imagem (Ecocardiograma ou Ressonância Magnética Cardíaca) de qualquer segmento da parede do ventrículo esquerdo com espessura > 15 mm, sem outra causa provável. A análise genética permite identificar mutações de genes codificantes de diferentes estruturas do sarcômero responsáveis pelo desenvolvimento da CMH em cerca de 60% dos casos, permitindo o rastreio de familiares e aconselhamento genético, como parte importante do manejo dos pacientes e familiares. Vários conceitos sobre a CMH foram recentemente revistos, incluindo sua prevalência de 1 em 250 indivíduos, não sendo, portanto, uma doença rara, mas subdiagnosticada. A vasta maioria dos pacientes é assintomática. Naqueles sintomáticos, a obstrução do trato de saída do ventrículo esquerdo (OTSVE) é o principal distúrbio responsável pelos sintomas, devendo-se investigar a sua presença em todos os casos. Naqueles em que o ecocardiograma em repouso ou com Manobra de Valsalva não detecta gradiente intraventricular significativo (> 30 mmHg), devem ser submetidos à ecocardiografia com esforço físico para detecção da OTSVE.   Pacientes com sintomas limitantes e grave OTSVE, refratários ao uso de betabloqueadores e verapamil, devem receber terapias de redução septal ou uso de novas drogas inibidoras da miosina cardíaca. Por fim, os pacientes adequadamente identificados com risco aumentado de morta súbita podem receber medida profilática com implante de cardiodesfibrilador implantável (CDI)

    Influence of temperature on the refractive index sensitivities of fiber Bragg gratings refractometers

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    Abstract Effect of cross-sensitivity between temperature and refractive index (RI) was studied using an optical sensor based on Bragg grating inscribed in an etched multi-mode fiber (MMF). RI sensitivities of different modes were used to obtain a linear response and temperature dependence in water:glycerin solutions. Results pointed out that the absolute average RI sensibility reduces from 0.97 ± 0.05 nm/RIU to 0.76 ± 0.07 nm/RIU while the temperature increases from 15 °C up to 35 °C, respectively. Effect of temperature on the RI sensitivity is related with the increasing difference between the fiber and surrounding RI, which results in lower evanescent field and, consequently, reduced surrounding RI sensitivity. Therefore, in order to improve the precision during the RI measures, the effect of temperature must be considered in the calibration curves, principally in MMF fiber grating sensors that show low RI sensitivity values

    Catalytic Performance of Ceria Nanorods in Liquid-Phase Oxidations of Hydrocarbons with tert-Butyl Hydroperoxide

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    The CeO2 nanorods (CeNR) promote the oxidation of ethylbenzene (PhEt) and cyclohexene with t-BuOOH, at temperatures as low as 55 ºC. For both substrates the saturated C-H bonds are preferentially activated over the unsaturated ones. The catalyst seems fairly stable towards leaching phenomena. The liquid-phase oxidation catalysis may be associated with the Ce3+/Ce4+ inter-conversion in the one-electron redox processes mediating the formation of tert-butyl-(per)oxy radicals. CeNR is very effective in H2O2 disproportionation. Pre-treatment of CeNR with H2O2 or t-BuOOH prior to the catalytic reaction enhances the reaction rate of PhEt with t-BuOOH in comparison to CeNR. Textural characterization and spectroscopic studies suggest that catalytic activation is associated to defect sites

    Luminescent SiO(2)-coated Gd(2)O(3):Eu(3+) nanorods/poly(styrene) nanocomposites by in situ polymerization

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    Europium doped gadolinium oxide nanorods have been coated with silica via a sol–gel approach. The silica coating increases the Eu3+ absolute emission quantum yields from 0.51 to 0.86 (255 nm excitation) and decay times from 1.43 to 1.80 ms (394.4 nm excitation). Subsequently the silica coating was modified with 3-(trimethoxysilyl)-propyl-methacrylate. Grafting of silica with the MPS coupling agent was confirmed by FTIR and contact angle measurements. The functionalized nanoparticles were used as core structures in the in situ radical polymerization of styrene via miniemulsion and solution routes. Depending on the polymerization technique used the morphology of the polymer coating consisted in isolated spheres or a homogenous film respectively. Although the optical properties of the ensuing nanocomposites were reduced the synthetic strategy developed to process this type of luminescent nanoparticles proved efficient and can be explored using different vinyl or (meth)acrylate monomers

    Cassia sieberiana DC. leaves modulate LPS-induced inflammatory response in THP-1 cells and inhibit eicosanoid-metabolizing enzymes

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    Ethnopharmacological relevance: According to ethnobotanical surveys, Cassia sieberiana DC. (1825) is a particularly reputed species in African folk Medicine, namely due to the application of its leaves and roots for the treatment of diseases and symptomatology that appear to be related with an inflammatory background. In contrast with the roots of the plant, the leaves remain to be investigated, which prompted us to further detail mechanisms underlying their anti-inflammatory properties, by using in vitro models of disease. Aim of the study: Considering its use in the amelioration and treatment of conditions that frequently underlie an inflammatory response, C. sieberiana leaves extract was prioritized amongst a collection of extracts obtained from plants collected in Guinea-Bissau. As such, this work aims to deliver experimental data on the anti-inflammatory properties of C. sieberiana leaf and to establish possible associations with its chemical composition, thus providing a rationale on its use in folk Medicine. Materials and methods: The chemical profile of an hydroethanol extract obtained from the leaves of the plant was established by HPLC-DAD-ESI/MS in order to identify bioactives. The extract and its main compound were tested towards a series of inflammatory mediators, both in enzymatic and cell-based models. The capacity to interfere with the eicosanoid-metabolizing enzymes 5-lipoxygenase (5-LOX), cyclooxygenase-1 (COX-1) and -2 (COX-2) was evaluated in cell-free systems, while the effects in interleukin 6 (IL-6) and tumour necrosis factor-α (TNF-α) levels produced by THP-1 derived macrophages were assessed through ELISA. Results: HPLC-DAD-ESI/MS analysis of the extract elucidated a chemical profile qualitatively characterized by a series of anthraquinones, particularly rhein derivatives, and nine flavonols, most of which 3-O-glycosylated. Considering the concentrations of the identified compounds, quercetin was detached as the main component. Effects of the hydroethanol extract obtained from C. sieberiana leaves against key enzymes of the arachidonic acid cascade were recorded, namely a concentration-dependent inhibition against 5-LOX, at concentrations ranging from 16 to 250 μg mL and a selective inhibitory action upon COX-2 (IC = 3.58 μg mL) in comparison with the isoform COX-1 (IC = 9.10 μg mL). Impact on inflammatory cytokines was also noted, C. sieberiana leaf extract significantly decreasing IL-6 levels in THP-1 derived macrophages at 250 and 500 μg mL. In contrast, TNF-α levels were found to be increased in the same model. Quercetin appears to partially account for the observed effects, namely due to the significant inhibitory effects on the activity of the arachidonic acid metabolizing enzymes COX-2 and 5-LOX. Conclusions: The anti-inflammatory effects herein reported provide a rationale for the use of C. sieberiana leaves in African folk practices, such as in the treatment of arthritis, rheumatism and body aches. Considering the occurrence of flavonoidic and anthraquinonic constituents, as well as the observed anti-inflammatory properties of quercetin, recorded effects must be related with the presence of several bioactives.This work was supported by UIDB/50006/2020 with funding from FCT/MCTES through national funds, and by Programa de Cooperación Interreg V-A España – Portugal (POCTEP) 2014–2020 (project 0377_IBERPHENOL_6_E). N. Gomes is indebted to national funds through FCT, under the project CEECIND/03037/2017.. Andreia P. Oliveira thanks to REQUIMTE for the research contract (DL57/2016/CP1346/CT0015). Tiago Macedo (SFRH/BD/144870/2019) thanks to FCT/MCTES

    Activation of caspase-3 in gastric adenocarcinoma AGS cells by Xylopia aethiopica (Dunal) A. Rich. fruit and characterization of its phenolic fingerprint by HPLC-DAD-ESI(Ion Trap)-MSn and UPLC-ESI-QTOF-MS2

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    While the fruits of Xylopia aethiopica (Dunal) A. Rich. are important in African countries as a local trade product, their composition remains scarcely investigated. Phenolic fingerprint is herein delivered through HPLC-DAD-ESI(Ion Trap)-MS and UPLC-ESI-QTOF-MS analysis, six cinnamoylquinic acid derivatives and twenty-four flavonoid glycosides being determined, chrysoeriol-7-O-glycosides being the main constituents. A cytotoxicity screening of twenty-eight hydroethanol extracts, obtained from a collection of Guinea-Bissauan plants, against A549 and AGS carcinoma cells, revealed the selective and potent effect towards AGS cells (IC = 151 × 10 g L), upon exposure to the extract from X. aethiopica fruits. Additional experiments demonstrated insignificant effect on LDH release at 151 × 10 g L, morphological analysis further suggesting induction of apoptosis. Pro-apoptotic effects were confirmed, as the extract enabled the activation of the effector caspase-3, broadening the knowledge on the anticancer mechanisms elicited by the fruits of X. aethiopica. Phenolic constituents might contribute to the cytotoxic effects, particularly via caspase-3 activation. Considering that X. aethiopica fruit is very often referred as an anticancer ingredient in Africa, but mainly the potent cytotoxicity herein recorded, our results call for additional research aiming to identify non-phenolic constituents contributing to the effects and also to further detail the anticancer mechanisms.The work was supported by UIDB/50006/2020 with funding from FCT/MCTES through national funds, and by Programa de Cooperación Interreg V-A España – Portugal (POCTEP) 2014–2020 [project 0377_IBERPHENOL_6_E], as well as COMPETE 2020 program, co-financed by the FEDER and the European Union, PTDC/ASP-AGR/30154/2017 (POCI-01-0145-FEDER-030154). The work was supported by UIDB/50006/2020 with funding from FCT/MCTES through national funds, and by Programa de Cooperación Interreg V-A España – Portugal (POCTEP) 2014–2020 (project 0377_IBERPHENOL_6_E). Andreia P. Oliveira thanks to REQUIMTE for the research contract (DL57/2016/CP1346/CT0015). N. Gomes is indebted to national funds through FCT, under the project CEECIND/03037/2017. Tiago Macedo (SFRH/BD/144870/2019) thanks to FCT/MCTES
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