3,844 research outputs found

    Trace anomaly and induced action for a metric-scalar background

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    The conformal anomaly and anomaly-induced effective action represent useful and economic ways to describe semiclassical contributions to the action of gravity. We discuss the anomaly in the case when the background is formed by metric and scalar fields and formulate the induced action in two standard covariant forms. The analysis of induced action at low energies reveals existing connection to the renormalization group and effective potential. The classification of anomalous terms is extended to the scalar background and ambiguities in the total derivative terms in the anomaly are considered using Pauli–Villars regularization

    Model amphipathic peptide coupled with tacrine to improve its antiproliferative activity

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    Drug repurposing and drug combination are two strategies that have been widely used to overcome the traditional development of new anticancer drugs. Several FDA-approved drugs for other indications have been tested and have demonstrated beneficial anticancer effects. In this connection, our research group recently reported that Tacrine, used to treat Alzheimer’s Disease, inhibits the growth of breast cancer MCF-7 cells both alone and in combination with a reference drug. In this view, we have now coupled Tacrine with the model amphipathic cell-penetrating peptide (CPP) MAP, to ascertain whether coupling of the CPP might enhance the drug’s antiproliferative properties. To this end, we synthesized MAP through solid-phase peptide synthesis, coupled it with Tacrine, and made a comparative evaluation of the parent drug, peptide, and the conjugate regarding their permeability across the blood-brain barrier (BBB), ability to inhibit acetylcholinesterase (AChE) in vitro, and antiproliferative activity on cancer cells. Both MAP and its Tacrine conjugate were highly toxic to MCF-7 and SH-SY5Y cells. In turn, BBB-permeability studies were inconclusive, and conjugation to the CPP led to a considerable loss of Tacrine function as an AChE inhibitor. Nonetheless, this work reinforces the potential of repurposing Tacrine for cancer and enhances the antiproliferative activity of this drug through its conjugation to a CPP.This work was financed by FEDER–Fundo Europeu de Desenvolvimento Regional through the COMPETE 2020—Operational Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT–Fundação para a Ciência e a Tecnologia, in a framework of CINTESIS, R&D Unit (reference UIDB/4255/2020), iMed.ULisboa (UID/DTP/04138/ 2013), LAQV-REQUIMTE (UIDB/50006/2020), and the “Institute for Research and Innovation in Health Sciences” (UID/BIM/04293/2019)

    Injeção de inseticidas no estipe de dendezeiros para controle de lagartas de Eupalamides dedalus (Cramer) (Lepidoptera: Castniidae).

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    Potential of omega-3 and conjugated fatty acids to control microglia inflammatory imbalance elicited by obesogenic nutrients

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    High-fat diet-induced obesity detrimentally affects brain function by inducing chronic low-grade inflammation. This neuroinflammation is, at least in part, likely to be mediated by microglia, which are the main immune cell population in the brain. Microglia express a wide range of lipid-sensitive receptors and their activity can be modulated by fatty acids that cross the blood-brain barrier. Here, by combining live cell imaging and FRET technology we assessed how different fatty acids modulate microglia activity. We demonstrate that the combined action of fructose and palmitic acid induce Ikβα degradation and nuclear translocation of the p65 subunit nuclear factor kB (NF-κB) in HCM3 human microglia. Such obesogenic nutrients also lead to reactive oxygen species production and LynSrc activation (critical regulators of microglia inflammation). Importantly, short-time exposure to omega-3 (EPA and DHA), CLA and CLNA are sufficient to abolish NF-κB pathway activation, suggesting a potential neuroprotective role. Omega-3 and CLA also show an antioxidant potential by inhibiting reactive oxygen species production, and the activation of LynSrc in microglia. Furthermore, using chemical agonists (TUG-891) and antagonists (AH7614) of GPR120/FFA4, we demonstrated that omega-3, CLA and CLNA inhibition of the NF-κB pathway is mediated by this receptor, while omega-3 and CLA antioxidant potential occurs through different signaling mechanisms.info:eu-repo/semantics/publishedVersio

    Purification of mercury-contaminated water using new AM-11 and AM-14 microporous silicates

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    Water is an essential resource on Earth and the maintenance of its quality led to the incentive of water reuse programmes. Among the most relevant contaminants, mercury is recognized for its toxicity and biomagnifica- tions along the food chain, reason why its removal from aqueous solutions was studied in this essay using two microporous materials for the first time. The ability of a niobium silicate, called AM-11 (Aveiro-Manchester No 11), and of a vanadium silicate, AM-14 (Aveiro-Manchester No 14), were assessed under batch conditions, at fixed temperature and pH. These microporous materials were synthesized and characterized by SEM, PXRD, ICP- OES, TGA and elemental analysis. Because of their excellent ion exchange properties, equilibrium and kinetics assays were performed using only a few mg dm−3 of material. The most relevant two- and three-parameter isotherms were used to fit the experimental data. Langmuir isotherm adjusted better the AM-11 data (deviation of 3.58 %, Radj 2 =0.980, AIC=52.8), predicting a maximum uptake of 161 mg g−1, while the AM-14 data were better fitted by the Temkin model (deviation of 3.92 %, Radj 2 =0.985, AIC=54.2). The kinetic study was per- formed using Elovich, pseudo-first order and pseudo-second order models. The pseudo–second order and Elovich equations provided the best fits for both materials. The Elovich equation achieved a better correlation in the initial branch while the pseudo-second order expression was more efficient for the horizontal branch. The in- traparticle diffusivities of counter ions were also assessed using a kinetic model based on the Nernst-Plank equations. Performance of these two microporous materials to remove mercury has been compared with other sorbents, highlighting their potential as ion exchangerspublishe

    Adubação Fosfatada para Cultivares de Mamoneira na região Sul do Rio Grande do Sul.

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    Controle químico de lagartas de Eupalamides dedalus em dendezeiros.

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    Deficiência de cálcio e fósforo em bubalinos no município de Portel, Estado do Pará.

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