Is the plant Bolboschoenus maritimus an adequate biomonitor for trace metal contamination in saltmarshes? A field study from the Óbidos lagoon (Portugal)

Monitoring the negative impacts of trace metals is crucial to assess the health and stability of ecosystems. In salt marshes, halophyte plants were reported as possible bioaccumulators of these elements. The aim of this work was to explore the bioaccumulation potential of Bolboschoenus maritimus as a tool for monitoring the presence of metals in coastal environments. Bolboschoenus maritimus were collected from a brackish water lagoon, and the presence of the trace metals lead, cadmium, and nickel were seasonally evaluated in distinct parts of the plants, and in water and sediment samples. Lead was the trace metal with the highest concentration detected in water and sediments of the sampling site. The highest lead concentrations in B. maritimus were recorded in the spring season. The transport index indicated an accumulation of lead in the leaves of around 70% in the spring of 2009. Cadmium in leaves in spring and summer of 2009 reached values above 5 mg Cd. kg−1. Nickel was not detected in most samples collected. Bolboschoenus maritimus was considered an adequate biomonitor for lead and cadmium, since it bioaccumulates both metals with seasonally distinct results, as the bioaccumulation factor results indicated.info:eu-repo/semantics/publishedVersio

The effect of a remifentanil bolus on the bispectral index of the EEG (BIS) in anaesthetized patients independently from intubation and surgical stimuli

Background and objective: Remifentanil boluses are used in different clinical situations and the effects on bispectral index monitoring are unclear. We analysed the effect of a remifentanil bolus on the bispectral index of the electroencephalogram (bispectral index) under total intravenous anaesthesia with propofol and remifentanil. Methods: ASA I–III patients were included in this study. All patients received a 2 µg kg 1 remifentanil bolus in a period free from stimuli. Bispectral index and haemodynamic data were collected from an A-2000XP bispectral index monitor (every second) and an AS/3 Datex monitor (every 5 s). Bispectral index data were analysed using the area under the curve. Mean arterial pressure and heart rate were averaged at each 30-s period and analysed using analysis of variance. Results: A total of 240 bispectral index values were obtained per patient. The area under the curve between 90 and 120 s after the bolus was significantly lower than the basal area under the curve (average of all areas before the bolus, P 0.05). Mean arterial pressure and heart rate were significantly reduced from 96.4 19.9 mmHg at the time of the bolus to 74.2 16.6 mmHg 120 s after, and from 70 16.4 bpm at the time of the bolus to 61 13.6 bpm after (P 0.001), respectively. Conclusions: There was a significant reduction in the areas under the curve between 90–120 s following the bolus. Heart rate and blood pressure also showed significant reductions. Thus, remifentanil bolus given under total intravenous anaesthesia with propofol and remifentanil decreases bispectral index, an effect independent of intubation and surgical stimuli.info:eu-repo/semantics/publishedVersio

Activation pathway to amino acid adducts

Funding: This work was supported in part by Fundação para a Ciência e a Tecnologia (FCT), Portugal (PTDC/QUI-QUI/113910/2009, RECI/QEQ-MED/0330/2012, UID/QUI/00100/2013 and IF/ 01091/2013/CP1163/CT0001), and by Interagency Agreement Y1ES1027 between the National Center for Toxicological Research/Food and Drug Administration and the National Institute of Environmental Health Sciences/National Toxicology Program. The opinions expressed in this paper do not necessarily represent those of the U.S. Food and Drug Administration. RW, ALG, ILM and SGH thank FCT for postdoctoral and doctoral fellowships (SFRH/BPD/70953/2010, SFRH/BD/72301/2010, SFRH/BD/75426/2010 and SFRH/BD/ 80690/2011, respectively). AMM also acknowledges Programa Operacional Potencial Humano from FCT and the European Social Fund (IF/01091/2013), and the LRI Innovative Science Award. We thank the Portuguese NMR and MS networks (IST nodes) for providing access to the facilities.Nevirapine (NVP) is the non-nucleoside HIV-1 reverse transcriptase inhibitor most commonly used in developing countries, both as a component of combined antiretroviral therapy and to prevent mother-to-child transmission of the virus; however, severe hepatotoxicity and serious adverse cutaneous effects raise concerns about its safety. NVP metabolism yields several phenolic derivatives conceivably capable of undergoing further metabolic oxidation to electrophilic quinoid derivatives prone to react with bionucleophiles and initiate toxic responses. We investigated the ability of two phenolic NVP metabolites, 2-hydroxy-NVP and 3-hydroxy-NVP, to undergo oxidation and subsequent reaction with bionucleophiles. Both metabolites yielded the same ring-contraction product upon oxidation with Frémy's salt in aqueous medium. This is consistent with the formation of a 2,3-NVP-quinone intermediate, which upon stabilization by reduction was fully characterized by mass spectrometry and nuclear magnetic resonance spectroscopy. Additionally, we established that the oxidative activation of 2-hydroxy-NVP involved the transient formation of both the quinone and a quinone-imine, whereas 3-hydroxy-NVP was selectively converted into 2,3-NVP-quinone. The oxidations of 2-hydroxy-NVP and 3-hydroxy-NVP in the presence of the model amino acids ethyl valinate (to mimic the highly reactive N-terminal valine of hemoglobin) and N-acetylcysteine were also investigated. Ethyl valinate reacted with both 2,3-NVP-quinone and NVP-quinone-imine, yielding covalent adducts. By contrast, neither 2,3-NVP-quinone nor NVP-derived quinone-imine reacted with N-acetylcysteine. The product profile observed upon Frémy's salt oxidation of 2-hydroxy-NVP in the presence of ethyl valinate was replicated with myeloperoxidase-mediated oxidation. Additionally, tyrosinase-mediated oxidations selectively yielded 2,3-NVP-quinone-derived products, while quinone-imine-derived products were obtained upon lactoperoxidase catalysis. These observations suggest that the metabolic conversion of phenolic NVP metabolites into quinoid electrophiles is biologically plausible. Moreover, the lack of reaction with sulfhydryl groups might hamper the in vivo detoxification of NVP-derived quinone and quinone-imine metabolites via glutathione conjugation. As a result, these metabolites could be available for reaction with nitrogen-based bionucleophiles (e.g., lysine residues of proteins) ultimately eliciting toxic events.publishersversionpublishe

Identifying imprints of externally derived dust and halogens in the sedimentary record of an Iberian alpine lake for the past ∼13,500 years – Lake Peixão, Serra da Estrela (Central Portugal)

Iberian lacustrine sediments are a valuable archive to document environmental changes since the last glacial termination, seen as key for anticipating future climate/environmental changes and their far-reaching implications for generations to come. Herein, multi-proxy-based indicators of a mountain lake record from Serra da Estrela were used to reconstruct atmospheric (in)fluxes and associated climatic/environmental changes over the last ∼13.5 ka. Depositions of long-range transported dust (likely from the Sahara) and halogens (primarily derived from seawater) were higher for the pre-Holocene, particularly in the late Bølling-Allerød–Younger Dryas period, compared to the Holocene. This synchronous increase could be related to a recognized dust-laden atmosphere, along with the combined effect of (i) an earlier proposed effective transport of Sahara dust for higher latitudes during cold periods and (ii) the progressive Polar Front expansion southwards, with the amplification of halogen activation reactions in lower latitudes due to greater closeness to snow/sea ice (halide-laden) surfaces. Additionally, the orographic blocking of Serra da Estrela may have played a critical role in increasing precipitation of Atlantic origin at higher altitudes, with the presence of snow prompting physical and chemical processes involving halogen species. In the Late Holocene, the dust proxy records highlighted two periods of enhanced input to Lake Peixão, the first (∼3.5–2.7 ka BP) after the end of the last African Humid Period and the second, from the 19th century onwards, agreeing with the advent of commercial agriculture, and human contribution to land degradation and dust emission in the Sahara/Sahel region. The oceanic imprints throughout the Holocene matched well with North Atlantic rapid climatic changes that, in turn, coincided with ice-rafted debris or Bond events and other records of increased storminess for the European coasts. Positive parallel peaks in halogens were found in recent times, probably connected to fire extinction by halogenated alkanes and roadway de-icing.This work was supported by the Portuguese Foundation for Science and Technology – FCT , through the HOLMODRIVE project ( PTDC/CTA-GEO/29029/2017 ) and P.M.R. grant ( DL57/2016/ICETA/EEC2018/25 ). The Estrela UNESCO Global Geopark is thanked for its support with field activities and permitting. The Parque Natural da Serra da Estrela, ICNF, provided research permits. Pedro J.M. Costa, Alberto Sáez, Santiago Giralt, and personnel of the Estrela UNESCO Global Geopark for fieldwork. Armand Hernández is funded by the Spanish Ministry of Science and Innovation through the Ramón y Cajal Scheme [ RYC2020-029253-I ]. We thank Vitor Magalhães and the EMSO-PT infrastructure project, with grant number POCI-01-0145-FEDER-022157 , for the XRF scanner analysis. A.M.R. and P.L. are supported by the Helmholtz “Changing Earth” program.Peer reviewe

A benchmark for validation of numerical results in sheet metal forming

Advances in FE codes for simulation of sheet metal forming processes have enabled its use during pre-production stage of a component. Some of recent developments include improvements and implementation of new material models of mechanical behaviour. However, these developments and corresponding results need to be validated, which means being compared with experimental results. On the other hand, in order that experimental results are a reference data, they need to be tested to repeatability and need to be obtained with such characteristic preferably by different institutions.http://www.sciencedirect.com/science/article/B6TGJ-4CS4NXC-M/1/11b425ff3006b6fcdad85f1f6b4fa57

Thermofluor-Based Optimization Strategy for the Stabilization of Recombinant Human Soluble Catechol-O-Methyltransferase

Funding Information: This work was supported by Laboratório de Fármaco-Toxicologia, UBIMedical, and by Centro de Competências em Cloud Computing, co-financed by the European Regional Development Fund (ERDF) through the Programa Operacional Regional do Centro (Centro 2020), in the scope of the Sistema de Apoio à Investigação Científica e Tecnológica-Programas Integrados de IC&DT (Centro-01-0145-FEDER-000019-C4). This work was developed within the scope of the CICS-UBI (projects UIDB/00709/2020, UIDP/00709/2020), CICECO-Aveiro Institute of Materials (projects UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020), the Applied Molecular Biosciences Unit UCIBIO (UIDB/04378/2020 and UIDP/04378/2020) and the Associate Laboratory Institute for Health and Bioeconomy—i4HB (project LA/P/0140/2020), which are financed by National Funds from FCT/MCTES. Researchers also acknowledge funding by FEDER through COMPETE 2020—Programa Operacional Competitividade e Internacionalização (POCI), and by national funds (OE), through FCT/MCTES from the project “IL2BioPro”-PTDC/BII-BBF/30840/2017. Ana M. Gonçalves’s individual PhD Fellowship (SFRH/BD/147519/2019), Augusto Q. Pedro research contract CEEC-IND/02599/2020 under the Scientific Stimulus—Individual Call, and Luís A. Passarinha’s sabbatical fellowship (SFRH/BSAB/150376/2019) from the Portuguese Foundation for Science and Technology (FCT) within the scope of POCH—Advanced Formation programs co-funded by European Social Fund and MCTES. Publisher Copyright: © 2022 by the authors.Catechol-O-methyltransferase (COMT) has been involved in a number of medical conditions including catechol-estrogen-induced cancers and a great range of cardiovascular and neurodegenerative diseases such as Parkinson’s disease. Currently, Parkinson’s disease treatment relies on a triple prophylaxis, involving dopamine replacement by levodopa, the use of aromatic L-amino acid decarboxylase inhibitors, and the use of COMT inhibitors. Typically, COMT is highly thermolabile, and its soluble isoform (SCOMT) loses biological activity within a short time span preventing further structural and functional trials. Herein, we characterized the thermal stability profile of lysate cells from Komagataella pastoris containing human recombinant SCOMT (hSCOMT) and enzyme-purified fractions (by Immobilized Metal Affinity Chromatography—IMAC) upon interaction with several buffers and additives by Thermal Shift Assay (TSA) and a biological activity assessment. Based on the obtained results, potential conditions able to increase the thermal stability of hSCOMT have been found through the analysis of melting temperature (Tm) variations. Moreover, the use of the ionic liquid 1-butyl-3-methylimidazolium chloride [C4mim]Cl (along with cysteine, trehalose, and glycerol) ensures complete protein solubilization as well as an increment in the protein Tm of approximately 10 °C. Thus, the developed formulation enhances hSCOMT stability with an increment in the percentage of activity recovery of 200% and 70% when the protein was stored at 4 °C and −80 °C, respectively, for 12 h. The formation of metanephrine over time confirmed that the enzyme showed twice the productivity in the presence of the additive. These outstanding achievements might pave the way for the development of future hSCOMT structural and biophysical studies, which are fundamental for the design of novel therapeutic molecules.publishersversionpublishe

Nanostructured electrospun fibers with self-assembled cyclo-L-Tryptophan-L-Tyrosine dipeptide as piezoelectric materials and optical sd harmonic generators

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/ma16144993/s1, Figure S1: Experimental setup for piezoelectric measurements; Figure S2: FTIR spectra; Figure S3: TGA spectra; Figure S4: DSC spectra. References [43,44] are cited in the supplementary materials.The potential use of nanostructured dipeptide self-assemblies in materials science for energy harvesting devices is a highly sought-after area of research. Specifically, aromatic cyclo-dipeptides containing tryptophan have garnered attention due to their wide-bandgap semiconductor properties, high mechanical rigidity, photoluminescence, and nonlinear optical behavior. In this study, we present the development of a hybrid system comprising biopolymer electrospun fibers incorporated with the chiral cyclo-dipeptide L-Tryptophan-L-Tyrosine. The resulting nanofibers are wide-bandgap semiconductors (bandgap energy 4.0 eV) consisting of self-assembled nanotubes embedded within a polymer matrix, exhibiting intense blue photoluminescence. Moreover, the cyclo-dipeptide L-Tryptophan-L-Tyrosine incorporated into polycaprolactone nanofibers displays a strong effective second harmonic generation signal of 0.36 pm/V and shows notable piezoelectric properties with a high effective coefficient of 22 pCN−1, a piezoelectric voltage coefficient of ge f f = 1.2 VmN−1 and a peak power density delivered by the nanofiber mat of 0.16 µWcm−2. These hybrid systems hold great promise for applications in the field of nanoenergy harvesting and nanophotonics.This research was funded by Fundação para a Ciência e Tecnologia through FEDER (European Fund for Regional Development)-COMPETE-QREN-EU (ref. UID/FIS/04650/2013 and UID/FIS/04650/2019) and E-Field “Electric-Field Engineered Lattice Distortions (E-FiELD)” for optoelectronic devices, ref. PTDC/NAN-MAT/0098/2020, POCI-01-0247-FEDER-045939