315 research outputs found
Hybrid GMR Sensor Detecting 950 pT/sqrt(Hz) at 1 Hz and Room Temperature.
Advances in the magnetic sensing technology have been driven by the increasing demand for the capability of measuring ultrasensitive magnetic fields. Among other emerging applications, the detection of magnetic fields in the picotesla range is crucial for biomedical applications. In this work Picosense reports a millimeter-scale, low-power hybrid magnetoresistive-piezoelectric magnetometer with subnanotesla sensitivity at low frequency. Through an innovative noise-cancelation mechanism, the 1/f noise in the MR sensors is surpassed by the mechanical modulation of the external magnetic fields in the high frequency regime. A modulation efficiency of 13% was obtained enabling a final device's sensitivity of ~950 pT/Hz1/2 at 1 Hz. This hybrid device proved to be capable of measuring biomagnetic signals generated in the heart in an unshielded environment. This result paves the way for the development of a portable, contactless, low-cost and low-power magnetocardiography device
Evolution of the angiopoietin-like gene family in teleosts and their role in skin regeneration
Background
The skin in vertebrates is a protective barrier and damage is rapidly repaired to re-establish barrier function and maintain internal homeostasis. The angiopoietin-like (ANGPTL) proteins are a family of eight secreted glycoproteins with an important role in skin repair and angiogenesis in humans. In other vertebrates their existence and role in skin remains largely unstudied. The present study characterizes for the first time the homologues of human ANGPTLs in fish and identifies the candidates that share a conserved role in skin repair using a regenerating teleost skin model over a 4-day healing period.
Results
Homologues of human ANGPTL1-7 were identified in fish, although ANGPTL8 was absent and a totally new family member designated angptl9 was identified in fish and other non-mammalian vertebrates. In the teleost fishes a gene family expansion occurred but all the deduced Angptl proteins retained conserved sequence and structure motifs with the human homologues. In sea bream skin angptl1b, angptl2b, angptl4a, angptl4b and angptl7 transcripts were successfully amplified and they were differentially expressed during skin regeneration. In the first 2 days of skin regeneration, re-establishment of the physical barrier and an increase in the number of blood vessels was observed. During the initial stages of skin regeneration angptl1b and angptl2b transcripts were significantly more abundant (p < 0.05) than in intact skin and angptl7 transcripts were down-regulated (p < 0.05) throughout the 4-days of skin regeneration that was studied. No difference in angptl4a and angptl4b transcript abundance was detected during regeneration or between regenerating and intact skin.
Conclusions
The angptl gene family has expanded in teleost genomes. In sea bream, changes in the expression of angptl1b, angptl2b and angptl7 were correlated with the main phases of skin regeneration, indicating the involvement of ANGPTL family members in skin regeneration has been conserved in the vertebrates. Exploration of the fish angptl family in skin sheds new light on the understanding of the molecular basis of skin regeneration an issue of importance for disease control in aquaculture.info:eu-repo/semantics/publishedVersio
Thermal imprinting modifies adult stress and innate immune responsiveness in the teleost sea bream
The impact of thermal imprinting on the plasticity of the hypothalamic-pituitary-interrenal (HPI) axis and stress response in an adult ectotherm, the gilthead sea bream (Sparus aurata, L.), during its development was assessed. Fish were reared under 4 thermal regimes, and the resulting adults exposed to acute confinement stress and plasma cortisol levels and genes of the HPI axis were monitored. Changes in immune function, a common result of stress, were also evaluated using histomorphometric measurements of melanomacrophages centers (MMCs) in the head kidney and by monitoring macrophage-related transcripts. Thermal history significantly modified the HPI responsiveness in adult sea bream when eggs and larvae were reared at a higher than optimal temperature (HT, 22 degrees C), and they had a reduced amplitude in their cortisol response and significantly upregulated pituitary pomc and head kidney star transcripts. Additionally, after an acute stress challenge, immune function was modified and the head kidney of adult fish reared during development at high temperatures (HT and LHT, 18-22 degrees C) had a decreased number of MMCs and a significant downregulation of dopachrome tautomerase. Thermal imprinting during development influenced adult sea bream physiology and increased plasma levels of glucose and sodium even in the absence of an acute stress in fish reared under a high-low thermal regime (HLT, 22-18 degrees C). Overall, the results demonstrate that temperature during early development influences the adult HPI axis and immune function in a teleost fish.project Lifecycle EU-FP7 [222719]FCT- Foundation for Science and Technology [CCMAR/Multi/04326/2013]info:eu-repo/semantics/publishedVersio
Interference-free determination of Ca in ultrapure water, concentrated acids and hydrogen peroxide using isotope dilution, ICP-MS and CH3F as a reaction gas
An analytical method was developed for Ca determination in ultrapure water, concentrated acids and hydrogen peroxide by ICP-MS, using CH3F as reaction gas in the dynamic reaction cell (DRC) and isotopic dilution (ID) as strategy of calibration for improve the accuracy and allow interference- free Ca determination
Preparation of controlled release microspheres using supercritical fluid technology for delivery of anti-inflammatory drugs
Ethylcellulose/methylcellulose blends were produced using different precipitation techniques and impregnated with naproxen, a non-steroidal
anti-inflammatory drug (NSAID). Solvent-evaporation technique was used not only for the preparation of ethylcellulose/methylcellulose microspheres
but also to encapsulate naproxen. Supercritical fluid (SCF) impregnation was also performed to prepare naproxen loaded microspheres. The
microspheres, impregnated by the SCF technique, were prepared both by solvent-evaporation and by a supercritical antisolvent (SAS) process. In
vitro release profiles at pH 7.4 and 1.2, of naproxen-loaded microspheres were evaluated and the results were modelled Fick’s law of diffusion and
Power law. Miscrospheres prepared by supercritical antisolvent have a higher loading capacity and present a slower release profile. The systems
studied present a release mechanism controlled by drug diffusion which complies Fick’s law of diffusion
Preparation of ethylcellulose/methylcellulose blends by supercritical antisolvent precipitation
The supercritical antisolvent (SAS) techniquewas used to prepare ethyl cellulose/methyl cellulose blends, two biocompatible polymers commonly
used as drug carriers in controlled delivery systems. Ethyl cellulose is widely used as a drug carrier. The drug release of the delivery devices can
be controlled to some extent by addition of a water-soluble or water swellable polymer, such as methyl cellulose. This leads to the solubility
enhancement of poorly water-soluble molecules. SAS experiments were carried out at different operational conditions and microspheres with mean
diameters ranging from 5 to 30 m were obtained. The effect of CO2 and liquid flow, temperature and pressure on particle size and particle size
distribution was evaluated. The microspheres were precipitated from a mixture of dichloromethane (DCM) and dimethylsulfoxide (DMSO) (4:1
ratio). The best process conditions for this mixture were according to our study 40 ◦C and 80 bar
Structural and biochemical characterization of the M405S variant of Desulfovibrio vulgaris formate dehydrogenase
Publisher Copyright: © 2024 International Union of Crystallography. All rights reserved. This work is financed by national funds from Fundação para a Ciência e a Tecnologia, I.P. (FCT) through fellowship 2023.00286.BD (to V-AG), project PTDC/BII-BBF/2050/2020, the Research Unit on Applied Molecular Biosciences (UCIBIO; UIDP/04378/2020 and UIDB/04378/2020) and MOSTMICRO-ITQB (UIDB/04612/2020 and UIDP/04612/ 2020) and Associate Laboratories Institute for Health and Bioeconomy i4HB (LA/P/0140/2020) and LS4FUTURE (LA/P/0087/2020).Molybdenum- or tungsten-dependent formate dehydrogenases have emerged as significant catalysts for the chemical reduction of CO2 to formate, with biotechnological applications envisaged in climate-change mitigation. The role of Met405 in the active site of Desulfovibrio vulgaris formate dehydrogenase AB (DvFdhAB) has remained elusive. However, its proximity to the metal site and the conformational change that it undergoes between the resting and active forms suggests a functional role. In this work, the M405S variant was engineered, which allowed the active-site geometry in the absence of methionine Sδ interactions with the metal site to be revealed and the role of Met405 in catalysis to be probed. This variant displayed reduced activity in both formate oxidation and CO2 reduction, together with an increased sensitivity to oxygen inactivation.publishersversionpublishe
The present and future offshore wind resource in the Southwestern African region
In the last decades, offshore wind harvesting has increased enormously, and is seen as a renewable energy resource with great potential in many regions of the world. Therefore, it is crucial to understand how this resource will evolve in a warming climate. In the present study, offshore wind resource in the Southwestern African region is analysed for the present and future climates. A ROM (REMO-OASIS-MPIOM) climate simulation in uncoupled and coupled atmosphere–ocean mode, at 25 km horizontal resolution, and a multi-model ensemble built with a set of regional climate models from the CORDEX-Africa experiment at 0.44° resolution were used. The projected changes of the offshore wind energy density throughout the twenty-first century are examined following the RCP4.5 and RCP8.5 greenhouse gas emissions scenarios. Characterised by strong coastal-parallel winds, the Southwestern African offshore region shows high values of wind energy density at 100 m, up to 1500 Wm⁻² near the coast, particularly offshore Namibia and west South Africa. Conversely, along Angola’s coast the available offshore wind energy density is lower. Throughout the twenty-first century, for the weaker climate mitigation scenario (RCP8.5), an increase of the offshore wind resource is projected to occur along Namibia and South African western coasts, more pronounced at the end of the century (+ 24%), while a decrease is projected along Angola’s coasts, reaching a negative anomaly of about − 32%. Smaller changes but with the same pattern are projected for the stronger climate mitigation scenario (RCP4.5). The future deployment of offshore floating hub turbines placed at higher heights may allow higher production of energy in this region. Along offshore Namibia and west South Africa, the wind energy density at 250 m showed differences that range between 30 and 50% relative to wind energy density at 100 m
Study of the Potential of Water Treatment Sludges in the Removal of Emerging Pollutants
This research was funded by CENSE through the Portuguese Foundation for Science and Technology (FCT; UIDB/04085/2020) and through a PhD grant for Rita Dias (SFRH/BD/148793/2019). The authors are also indebted to EPAL AdVT for their financial support to this project. This work was also supported by the Associate Laboratory for Green Chemistry-LAQV, which is financed by national funds from FCT/MCTES (UIDB/50006/2020). Maria Bernardo acknowledges Norma Transitoria DL57/2016 Contract (FCT/MCTES).Presently, water quantity and quality problems persist both in developed and developing countries, and concerns have been raised about the presence of emerging pollutants (EPs) in water. The circular economy provides ways of achieving sustainable resource management that can be implemented in the water sector, such as the reuse of drinking water treatment sludges (WTSs). This study evaluated the potential of WTS containing a high concentration of activated carbon for the removal of two EPs: the steroid hormones 17β-estradiol (E2) and 17α-ethinylestradiol (EE2). To this end, WTSs from two Portuguese water treatment plants (WTPs) were characterised and tested for their hormone adsorbance potential. Both WTSs showed a promising adsorption potential for the two hormones studied due to their textural and chemical properties. For WTS1, the final concentration for both hormones was lower than the limit of quantification (LOQ). As for WTS2, the results for E2 removal were similar to WTS1, although for EE2, the removal efficiency was lower (around 50%). The overall results indicate that this method may lead to new ways of using this erstwhile residue as a possible adsorbent material for the removal of several EPs present in wastewaters or other matrixes, and as such contributing to the achievement of Sustainable Development Goals (SDG) targets.publishersversionpublishe
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