877 research outputs found

    NAP-2 Secreted by Human NK Cells Can Stimulate Mesenchymal Stem/Stromal Cell Recruitment

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    SummaryStrategies for improved homing of mesenchymal stem cells (MSCs) to a place of injury are being sought and it has been shown that natural killer (NK) cells can stimulate MSC recruitment. Here, we studied the chemokines behind this recruitment. Assays were performed with bone marrow human MSCs and NK cells freshly isolated from healthy donor buffy coats. Supernatants from MSC-NK cell co-cultures can induce MSC recruitment but not to the same extent as when NK cells are present. Antibody arrays and ELISA assays confirmed that NK cells secrete RANTES (CCL5) and revealed that human NK cells secrete NAP-2 (CXCL7), a chemokine that can induce MSC migration. Inhibition with specific antagonists of CXCR2, a receptor that recognizes NAP-2, abolished NK cell-mediated MSC recruitment. This capacity of NK cells to produce chemokines that stimulate MSC recruitment points toward a role for this immune cell population in regulating tissue repair/regeneration

    Inorganic Chemical Composition Analysis of 10 Different Types of Commercial Salt by Wavelength Dispersive X-Ray Fluorescence (WDXRF) Method

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    Salt is one of the most used seasoning in culinary with a great variety of them. Despite that, there is not a lot of published studies that analyses its compositions, differences and similarities between them. Thus, this research aims to determine the inorganic composition of table, light, pink and black Himalayan, Hawaii’s red, Persian blue, Mediterranean sea and three Argentinian gourmet salts by the Wavelength Dispersive X-ray Fluorescence (WDXRF) method in order to compare them using PCA and HCA analysis. Na and Cl were major elements found in all samples. As for trace elements: Al, Si, S and K in drastically different concentrations, due to conservation of nutrients from the soil, water or additives. These differences were used to distinct three groups showing that there is between 70 and 60% similarity among the nine samples, while the light salt does not have similarity to any other salt studied

    Quadro referencial teórico do raciocínio clínico em fisioterapia neurológica: NeuroQR

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    A Fisioterapia Neurológica (FN), intervém nos indivíduos que sofrem de doenças que afetam o sistema nervoso e que provocam distúrbios motores, que se traduzem em alterações complexas do movimento e da funcionalidade. A FN é uma área científica que evoluiu fortemente nas últimas décadas. O conhecimento adquirido ao longo dos anos exige um raciocínio clínico sólido e uma gestão bem estruturada para a sua incorporação adequada na prática clínica. Embora a literatura atual forneça muitas informações sobre o raciocínio clínico e a tomada de decisão em fisioterapia, são poucos os artigos que discutem o raciocínio clínico específico da FN. O objetivo deste artigo é apresentar um quadro referencial teórico para o raciocínio clínico do fisioterapeuta que atua junto aos utentes com disfunções motoras e funcionais decorrentes de distúrbios neurológicos. O modelo descrito está dividido em 4 níveis – conceitos, abordagens, métodos e técnicas, foi construído pelo grupo de FN do departamento da ESSAlcoitão e tem por base outros quadros referenciais previamente publicados.info:eu-repo/semantics/publishedVersio

    Fresnel Lens Solar Pumping for Uniform and Stable Emission of Six Sustainable Laser Beams under Non-Continuous Solar Tracking

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    Funding Information: The FCT-MCTES fellowship grants SFRH/BPD/125116/2016, SFRH/BD/145322/2019, 2021.06172.BD, PD/BD/1428/2018, and CEECIND/03081/2017 of Cláudia R. Vistas, Miguel Catela, Hugo Costa, Dário Garcia and Joana Almeida, respectively, are acknowledged. Funding Information: This research was funded by the Science and Technology Foundation of Portuguese Ministry of Science, Technology and Higher Education (FCT-MCTES), through the strategic project UIDB/00068/2020 and the exploratory research project EXPL/FIS-OTI/0332/2021. Publisher Copyright: © 2023 by the authors.A multirod solar laser approach is here proposed to attain uniform and stable multibeam emission under non-continuous solar tracking. A Fresnel lens was used as the primary concentrator. The laser head was composed of a second-stage aspherical lens with a light-guide homogenizer and a third-stage conical pump cavity with six Nd:YAG rods. The solar laser system was optimized through numerical analysis in both Zemax® and LASCAD™ software to obtain six 1064 nm laser beams of similar multimode power. To investigate the effect of the homogenizer on the laser performance, the laser head was compared with a similar one that only used the aspherical lens in the second stage. The approach with the light guide attained a slightly lower efficiency than the one without the light guide; however, the tracking error width at 10% laser power loss was higher and, most importantly, only a 2.17% coefficient of variation of the laser power emitted by the six rods at the tracking error angle of ±0.5° was obtained. This is 4.2 times better than the 52.31% obtained with the laser head without the homogenizer and 76 times better than that of the previous numerical work. The light guide is thus essential to ensure uniform and stable solar laser power extraction from all rods even under non-continuous solar tracking, making this prototype the ideal for multibeam laser applications where uniformity and stability of the laser power are indispensable. This renewable multibeam solar laser may replace the classical lamp- and diode-pumped lasers, therefore ensuring a sustainable laser power production pattern for both space and terrestrial applications.publishersversionpublishe

    Zigzag multirod laser beam merging approach for brighttem00-mode solar laser emission from a megawatt solar furnace

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    An alternative multirod solar laser end-side-pumping concept, based on the megawatt solar furnace in France, is proposed to significantly improve the TEM00-mode solar laser output power level and its beam brightness through a novel zigzag beam merging technique. A solar flux homogenizer was used to deliver nearly the same pump power to multiple core-doped Nd:YAG laser rods within a water-cooled pump cavity through a fused silica window. Compared to the previous multibeam solar laser station concepts for the same solar furnace, the present approach can allow the production of high-power TEM00-mode solar laser beams with high beam brightness. An average of 1.06 W TEM00-mode laser power was numerically extracted from each of 1657 rods, resulting in a total of 1.8 kW. More importantly, by mounting 399 rods at a 30◦ angle of inclination and employing the beam merging technique, a maximum of 5.2 kW total TEM00-mode laser power was numerically extracted from 37 laser beams, averaging 141 W from each merged beam. The highest solar laser beam brightness figure of merit achieved was 148 W, corresponding to an improvement of 23 times in relation to the previous experimental record.publishersversionpublishe

    Ce:Nd:YAG Solar Laser with 4.5% Solar-to-Laser Conversion Efficiency

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    Publisher Copyright: © 2022 by the authors.The efficiency potential of a small-size solar-pumped laser is studied here. The solar laser head was composed of a fused silica aspheric lens and a conical pump cavity, which coupled and redistributed the concentrated solar radiation from the focal zone of a parabolic mirror with an effective collection area of 0.293 m2 to end-side pump a Ce (0.1 at%):Nd (1.1 at%):YAG rod of 2.5 mm diameter and 25 mm length. Optimum solar laser design parameters were found through Zemax© non-sequential ray-tracing and LASCAD™ analysis. The utilization of the Ce:Nd:YAG medium with small diameter pumped by a small-scale solar concentrator was essential to significantly enhance the end-side pump solar laser efficiency and thermal performance. For 249 W incoming solar power at an irradiance of 850 W/m2, 11.2 W multimode solar laser power was measured, corresponding to the record solar-to-laser power conversion efficiency of 4.50%, being, to the best of our knowledge, 1.22 times higher than the previous record. Moreover, the highest solar laser collection efficiency of 38.22 W/m2 and slope efficiency of 6.8% were obtained, which are 1.18 and 1.02 times, respectively, higher than the previous records. The lowest threshold solar power of a Ce:Nd:YAG solar-pumped laser is also reported here.publishersversionpublishe

    Doughnut-shaped and top hat solar laser beams numerical analysis

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    UIDB/00068/2020Aside from the industry-standard Gaussian intensity profile, top hat and non-conventional laser beam shapes, such as doughnut-shaped profile, are ever more required. The top hat laser beam profile is well-known for uniformly irradiating the target material, significantly reducing the heat-affected zones, typical of Gaussian laser irradiation, whereas the doughnut-shaped laser beam has attracted much interest for its use in trapping particles at the nanoscale and improving mechanical performance during laser-based 3D metal printing. Solar-pumped lasers can be a cost-effective and more sustainable alternative to accomplish these useful laser beam distributions. The sunlight was collected and concentrated by six primary Fresnel lenses, six folding mirror collectors, further compressed with six secondary fused silica concentrators, and symmetrically distributed by six twisted light guides around a 5.5 mm diameter, 35 mm length Nd:YAG rod inside a cylindrical cavity. A top hat laser beam profile (Mx2 = 1.25, My2 = 1.00) was computed through both ZEMAX® and LASCAD® analysis, with 9.4 W/m2 TEM00 mode laser power collection and 0.99% solar-to-TEM00 mode power conversion efficiencies. By using a 5.8 mm laser rod diameter, a doughnut-shaped solar laser beam profile (Mx2 = 1.90, My2 = 1.00) was observed. The 9.8 W/m2 TEM00 mode laser power collection and 1.03% solar-to-TEM00 mode power conversion efficiencies were also attained, corresponding to an increase of 2.2 and 1.9 times, respectively, compared to the state-of-the-art experimental records. As far as we know, the first numerical simulation of doughnut-shaped and top hat solar laser beam profiles is reported here, significantly contributing to the understanding of the formation of such beam profiles.publishersversionpublishe

    40 W Continuous Wave Ce:Nd:YAG Solar Laser through a Fused Silica Light Guide

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    Funding Information: Funding: This research was financially supported by Science and Technology Foundation of Portuguese Ministry of Science, Technology and Higher Education (FCT-MCTES) in the framework of the strategic project UIDB/00068/2020 and the exploratory research project EXPL/FIS-OTI/0332/2021. The solar laser research was also supported by the Solar Facilities for European Research Area–Third Phase (SFERA III), Grant Agreement No. 823802. Funding Information: Acknowledgments: The authors express their gratitude for the FCT-MCTES fellowship grants CEECIND/03081/2017, PD/BD/142827/2018, PD/BD/128267/2016, 2021.06172.BD, SFRH/BD/ 145322/2019 and SFRH/BPD/125116/2016. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.The solar laser power scaling potential of a side-pumped Ce:Nd:YAG solar laser through a rectangular fused silica light guide was investigated by using a 2 m diameter parabolic concentrator. The laser head was formed by the light guide and a V-shaped pump cavity to efficiently couple and redistribute the concentrated solar radiation from the parabolic mirror to a 4 mm diameter, 35 mm length Ce(0.1 at.%):Nd(1.1 at.%):YAG laser rod. The rectangular light guide ensured a homogeneous distribution of the solar radiation along the laser rod, allowing it to withstand highly concentrated solar energy. With the full collection area of the parabolic mirror, the maximum continuous wave (cw) solar laser power of 40 W was measured. This, to the best of our knowledge, corresponds to the highest cw laser power obtained from a Ce:Nd:YAG medium pumped by solar radiation, representing an enhancement of two times over that of the previous side-pumped Ce:Nd:YAG solar laser and 1.19 times over the highest Cr:Nd:YAG solar laser power with a rectangular light-guide. This research proved that, with an appropriate pumping configuration, the Ce:Nd:YAG medium is very promising for scaling solar laser output power to a higher level.publishersversionpublishe

    Marine Operations with the SWORDFISH Autonomous Surface Vehicle

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    IEEE Robótica 2007 - 7th Conference on Mobile Robots and Competitions, Paderne, Portugal 2007This paper describes the design and development of the Swordfish Autonomous Surface Vehicle (ASV) system. The work focuses the sensors, actuators, communications and C4I of an unmanned vehicle for marine operations. SWORDFISH is an autonomous surface vehicle used as the central communications link between air, undersea, and terrestrial robotic vehicles of a network centric operation. It is used as a test bed platform for deployment and testing of advanced control and operational concepts for multi-vehicles systems. This new unmanned marine vehicle was done in the context of the PISCIS project. The PISCIS project concerns the development, test and evaluation of new vehicles and new concepts of operation for networked vehicle systems in oceanographic data collection. The PISCIS system includes two autonomous underwater vehicles, the Swordfish ASV, an acoustic navigation system, acoustic and radio communications and a distributed command and control system

    Development and characterization of a novel hybrid tissue engineering-based scaffold for spinal cord injury repair

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    Spinal cord injury (SCI) represents a significant health and social problem, and therefore it is vital to develop novel strategies that can specifically target it. In this context, the objective of the present work was to develop a new range of three-dimensional (3D) tubular structures aimed at inducing the regeneration within SCI sites. Up to six different 3D tubular structures were initially developed by rapid prototyping: 3D bioplotting–based on a biodegradable blend of starch. These structures were then further complemented by injecting Gellan Gum, a polysaccharide-based hydrogel, in the central area of structures. The mechanical properties of these structures were assessed using dynamic mechanical analysis, under both dry and wet conditions, and their morphologies= porosities were analyzed using micro-computed tomography and scanning electron microscopy. Biological evaluation was carried out to determine their cytotoxicity, using both minimum essential medium (MEM) extraction and MTS tests, as well as by encapsulation of an oligodendrocyte-like cell (M03-13 cell line) within the hydrogel phase. The histomorphometric analysis showed a fully interconnected network of pores with porosity ranging from 70% to 85%. Scaffolds presented compressive modulus ranging from 17.4 to 62.0MPa and 4.42 to 27.4 MPa under dry and wet conditions, respectively. Cytotoxicity assays revealed that the hybrid starch=poly-ecaprolactone= Gellan Gum scaffolds were noncytotoxic, as they did not cause major alterations on cell morphology, proliferation, and metabolic viability. Moreover, preliminary cell encapsulation assays showed that the hybrid scaffolds could support the in vitro culture of oligodendrocyte-like cells. Finally, preliminary in vivo studies conducted in a hemisection rat SCI model revealed that the above-referred structures were well integrated within the injury and did not trigger chronic inflammatory processes. The results herein presented indicate that these 3D systems might be of use in future SCI regeneration approaches.Portuguese Foundation for Science and Technology through funds from Programa Operacional Ciencia, Tecnologia, Inovacao (POCTI) and/or Fundo Europeu de Desenvolvimento Regional (FEDER) programs (funding to ICVS, 3B's Research Group, predoctoral and postdoctoral fellowships to N. A. Silva, J. T. Oliveira, A. J. Salgado, and R. A. Sousa-SFRH/BD/40684/2007; SFRH/BD/17135/2004; SFRH/BPD/17595/2004; SFRH/BPD/17151/2004)
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