Carbonic nanoparticles and C-S-H insertion into cementitious nanocomposite

Use of nanomaterials in cementitious nanocomposites is a possibility to improving mechanical properties as well as increased durability. In this research the insertion of multi-walled carbon nanotubes (MWCNT) and particles of Calcium Silicate Hydrate (C-S-H) with Ca/Si=0.8 and Ca/Si=1.2 ratios were used in microconcrete specimens. The effects on the compressive and tensile strength were tested, besides analysis of the porous structure by mercury intrusion, as well as the microstructure by scanning electron microscopy. Nanocomposites were produced by varying NTCPM insertions at 0.1% and 0.2% and C-S-H inserts at 1% and 2%, all of them based on cement mass. The results showed that the nanocomposites with C-S-H insertion with Ca/Si=0.8 ratio were the least porous and presented the highest tensile and compressive strengths, reaching strength increases in the order of 30% compared to the control material because C-S-H insertion with Ca/Si=0.8 ratio is reactive and causes reduction of the total porosity

Vescalagin and castalagin reduce the toxicity of amyloid-beta42 oligomers through the remodelling of its secondary structure

Accepted Manuscript ; "First published on 10 Feb 2020"The isomers vescalagin and castalagin protect SH-SY5Y cells from Aβ42-mediated death. This is achieved better by vescalagin due to the spatial organization of its OH group at the C1 position of the glycosidic chain, improving its capacity to remodel the secondary structure of toxic Aβ42 oligomers.We acknowledge the financial support from the EC (FORECAST - 668983 and THE DISCOVERIES CTR – 739572), “Programa Operacional Regional do Norte”, “Fundo Social Europeu”, Norte2020 TERM&SC, for the PhD grant NORTE-08-5369-FSE-000044; PT acknowledges Agencia Estatal de Investigación (AEI) for Project MAT2016-80266-R, and “Xunta de Galicia” for grants “Grupo de Referencia Competitiva” ED431C 2018/26 and “Agrupación Estratégica en Materiales-AEMAT” ED431E 2018/08, respectively. ERDF funds are also acknowledged

Deciphering the interaction of lactoferrin with V-ATPase towardsa deeper understanding of its mechanisms of action

Lactoferrin (Lf), a bioactive milk protein, exhibits strong anticancer and antifungal activities. The search for Lf targets and mechanisms of action is of utmost importance to enhance its effective applications. A common feature among Lf-treated cancer and fungal cells is the inhibition of a proton pump called V-ATPase. Lf-driven V-ATPase inhibition leads to cytosolic acidification, ultimately causing cell death of cancer and fungal cells. Given that a detailed elucidation of how Lf and V-ATPase interact is still missing, in this work we aimed to fill this gap by employing a multilevel computational approach. Molecular dynamics (MD) simulations of both proteins were performed to obtain a robust sampling of their conformational landscape, followed by clustering and protein-protein docking. Subsequently, MD simulations of the docked complexes and free binding energy calculations were carried out to evaluate the dynamic binding process and build the final ranking. This computational pipeline allowed the unraveling of the putative mechanism by which Lf inhibits V-ATPase and the identification of key binding residues that will certainly aid in the rational design of follow-up experimental studies, bridging in this way computational and experimental biochemistry.info:eu-repo/semantics/publishedVersio

Synthesis and cytotoxicity assessment of citrate-coated calcium and manganese ferrite nanoparticles for magnetic hyperthermia

Calcium-doped manganese ferrite nanoparticles (NPs) are gaining special interest in the biomedical field due to their lower cytotoxicity compared with other ferrites, and the fact that they have improved magnetic properties. Magnetic hyperthermia (MH) is an alternative cancer treatment, in which magnetic nanoparticles promote local heating that can lead to the apoptosis of cancer cells. In this work, manganese/calcium ferrite NPs coated with citrate (CaxMn1−xFe2O4 (x=0, 0.2, 1), were synthesized by the sol-gel method, followed by calcination, and then characterized regarding their crystalline structure (by X-ray diffraction, XRD), size and shape (by Transmission Electron Microscopy, TEM), hydrodynamic size and zeta potential (by Dynamic Light Scattering, DLS), and heating efficiency (measuring the Specific Absorption Rate, SAR, and Intrinsic Loss Power, ILP) under an alternating magnetic field. The obtained NPs showed a particle size within the range of 10 nm to 20 nm (by TEM) with a spherical or cubic shape. Ca0.2Mn0.8Fe2O4 NPs exhibited the highest SAR value of 36.3 W/g at the lowest field frequency tested, and achieved a temperature variation of ~7 °C in 120 s, meaning that these NPs are suitable magnetic hyperthermia agents. In vitro cellular internalization and cytotoxicity experiments, performed using the human cell line HEK 293T, confirmed cytocompatibility over 0–250 µg/mL range and successful internalization after 24 h. Based on these studies, our data suggest that these manganese-calcium ferrite NPs have potential for MH application and further use in in vivo systems.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of CEB (UIDB/04469/2020), CBMA (UIDB/04050/2020) and CF-UM-UP (UIDB/04650/2020) units. R.G.D. Andrade and S.R.S. Veloso acknowledge FCT for the PhD grants 2020.05781.BD and SFRH/BD/144017/2019, respectively.info:eu-repo/semantics/publishedVersio

New magnetogels based on manganese ferrite nanoparticles and self-assembled peptide hydrogels as drug nanocarriers

In this work, superparamagnetic manganese ferrite (MnFe2O4) nanoparticles were successfully incorporated in self-assembled peptide-derived hydrogels. The new magnetogels were tested as nanocarriers for two fluorescent drugs, curcumin (an anticancer and neuroprotective drug) and a new antitumor thienopyridine derivative. Fluorescence-based techniques (fluorescence emission, FRET and fluorescence anisotropy) were used to assess incorporation of these drugs in the magnetogels and their transport towards models of biological membranes. It can be observed that the drug moves to the model membranes upon interaction of the drug-loaded magnetogels with membranes.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CF-UM-UP (UID/FIS/04650/2013) and of CQ-UM (UID/QUI/00686/2013). FCT, POPH-QREN and FSE are acknowledged for the PhD grant of A.R.O. Rodrigues (SFRH/BD/90949/2012) and for financial support to MAP-Fis Joint Doctoral Programme.info:eu-repo/semantics/publishedVersio

Antennal sensilla of two species of Gymnetis MacLeay, 1819 (Coleoptera: Scarabaeidae: Cetoniinae)

ABSTRACT The present study describes the morphology of the antennal sensilla of adults of Gymnetis holosericea (Voet, 1779) and Gymnetis rufilateris (Illiger, 1800). The adults of Gymnetis spp. were sexed and antenna of males and females were dissected. Both species have sensilla chaetica, trichodea, placodea (type I and II), coeloconica (type I and II), and ampullacea (or pore). Females of G. holosericea have a total of about 19,995 sensilla and males have about 23,273 sensilla, and females of G. rufilateris have about 16,633 sensilla and males have about 21,184 sensilla. Sensilla placodea are the predominant type of sensilla in males and females of G. holosericea and G. rufilateris

Origem e morfologia dos tanques naturais do Nordeste do Brasil

Natural tanks of Northeastern Brazil have been widely analyzed in paleontological terms. However, studies related to the origin and morphology of these natural depressions are stagnated since the 1990s. This work aims to present new interpretations about the origin of these tanks, as well as to establish an internationally correlated nomenclature and to propose a morphological classification of these features. Academic works elaborated from the beginning of the 19th century until more recent articles, including theses and dissertations, have been consulted on the application of the term, the paleontological importance and origin of the natural tanks in northeastern Brazil. We propose the use of the term natural tank (shallow and steeped) to depressions of non-fluvial origins on the bedrock, and maintain the term caldrons to those of fluvial origin. The previous models for the formation of natural tanks were based on three situations in subaerial environment. In this work, we associate the chemical corrosion and migration and concentration of charges in subsurface as important processes for the genesis of natural tanks. Instead of the necessity of the surface be exposed to start the formation of the cavity, the tank may have its origin and development associated with subedaphic environment.Os tanques naturais do Nordeste do Brasil têm sido amplamente analisados em termos paleontológicos. Entretanto, estudos relacionados à origem e morfologia dessas depressões naturais encontram-se estagnados desde a década de 1990. O presente trabalho tem como objetivo apresentar novas interpretações sobre a gênese desses tanques, bem como estabelecer uma nomenclatura correlacionável internacionalmente e propor uma classificação morfológica dessas feições. Foram consultados trabalhos acadêmicos elaborados desde o início do século XIX até artigos mais recentes, incluindo teses e dissertações, sobre a utilização do termo, a importância paleontológica e origem dos tanques naturais no nordeste brasileiro. Este trabalho propõe a utilização do termo tanque natural (raso e escarpado) para as cavidades naturais, de origens não-fluviais, sobre o embasamento cristalino, e manter o termo marmita, ou caldeirões, para aquelas de origem fluvial. Os modelos prévios para a origem dos tanques baseavam-se em três importantes situações, em ambiente subaéreo, para a formação dessas cavidades. Neste trabalho associa-se a corrosão química e a migração e concentração de cargas em subsuperfície como processos importantes para a gênese dos tanques naturais. Ao contrário da necessidade da superfície estar exposta para iniciar a formação da cavidade, o tanque pode ter sua origem e desenvolvimento associado ao ambiente subedáfico

Selection of a new peptide homing SK-BR-3 breast cancer cells

Breast cancer diagnosis remains a challenge, mostly due to its heterogeneity. This reality translates in delayed treatments, increasing treatment aggressiveness and lower chances of overall survival. The conventional detection techniques, although becoming increasingly sophisticated each year, still lack the ability to provide reliable conclusions without being time consuming, expensive and uncomfortable for the patients. The identification of novel biomarkers for breast cancer research is therefore of utmost relevance for an early diagnosis. Moreover, breast cancer specific peptide moieties can be used to develop novel targeted drug delivery systems. In this work we used phage display to identify a novel peptide with specificity to the SK-BR-3 breast cancer cell line. Cytometry assays confirmed its specificity, while bioinformatics and docking studies predicted the potential biomarkers at the SK-BR-3 cells surface. These findings can be potentially useful in the clinical context, contributing to more specific and targeted therapeutic solutions against HER2-positive breast cancer subtypes.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Débora Ferreira and Ana Cláudia Pereira are recipient of fellowships supported by a doctoral advanced training (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Cátia Santos-Pereira acknowledges the PhD fellowship PD/BD/128032/2016 funded by FCT under the scope of the doctoral programme in Applied and Environmental Microbiology (DP_AEM). The authors also acknowledge César Pimenta from NOVA Institute of Chemical and Biological Technology António Xavier (NOVA ITQB) for the docking insights.info:eu-repo/semantics/publishedVersio