531 research outputs found
Valorization of watermelon fruit (Citrullus lanatus) byproducts: phytochemical and biofunctional properties with emphasis on recent trends and advances
Watermelon (Citrullus lanatus) a fruit crop, is an herbaceous creeping plant belonging to the family
Cucurbitaceae. It is a tropical plant, mainly propagated by seeds and thrives best in warm areas. While the
fruit pulp is consumed, seeds are often discarded. The continuously growing global market for the main
tropical fruits is currently estimated at 85 million tons, of which approximately half is lost or wasted
throughout the whole processing chain. Developing novel processes for the conversion of these byproducts
into value‐added products could provide a viable way to manage this waste problem, aiming at the same
time to create a sustainable economic growth within a bio‐economy perspective. Given the ever‐increasing
concern about sustainability, complete valorization through a bio‐refinery approach, that is, zero waste
concepts is therefore most important. This paper aims to report the status on the valorization of tropical
fruit byproducts, more specifically in watermelon seeds and their content in bioactive compounds, such as
phenolic acids, flavonoids, carotenoids, alkaloids. Moreover, the bioactivity of the different types of
phytochemicals and their possible application as a resource for different sectors (food, pharmaceutical, and
environmental sciences) is discussed. Consequently, this review presents the concepts of tropical fruit
byproducts recovery, and the potential applications of the isolated fractions.info:eu-repo/semantics/publishedVersio
Post-stroke patients functional task characterization through accelerometry data for rehabilitation intervention and monitoring
An increasing ageing society and consequently rising number ofpost-stroke related neurological dysfunction patients are forcing therehabilitation field to adapt to ever-growing demands. Compensatorymovements related to available motor strategies, can be observed inpost-stroke patients when performing functional tasks due to apathological synergy as in reaching for an object. Studies of post-strokemotor recovery suggest that such maladaptive strategies may limit theplasticity of the nervous system to enhance neuromotor recovery.Strategies for rehabilitation protocols monitoring and validation arepresently a necessity, moreover considering data recording is oftenabsent of the rehabilitation process or subjective in nature.Characterization strategies of patient performance during functional taskare key aspects for clinical protocols validation, progress monitoring andmethodologies comparison. This project seeks to characterize patientsupper limb performance through accelerometry, gathered with a lowcostwearable system, for compensatory movement avoidance throughfeedback response
Chitosan increases Pinus pinaster tolerance to the pinewood nematode (Bursaphelenchus xylophilus) by promoting plant antioxidative metabolism
The pine wilt disease (PWD), for which no effective treatment is available at the moment, is a constant threat to Pinus spp. plantations worldwide, being responsible for significant economic and environmental losses every year. It has been demonstrated that elicitation with chitosan increases plant tolerance to the pinewood nematode (PWN) Bursaphelenchus xylophilus, the causal agent of the PWD, but the biochemical and genetic aspects underlying this response have not been explored. To understand the influence of chitosan in Pinus pinaster tolerance against PWN, a low-molecular-weight (327 kDa) chitosan was applied to mock- and PWN-inoculated plants. Nematode population, malondialdehyde (MDA), catalase, carotenoids, anthocyanins, phenolic compounds, lignin and gene expression related to oxidative stress (thioredoxin 1, TRX) and plant defence (defensin, DEF, and a-farnesene synthase, AFS), were analysed at 1, 7, 14, 21 and 28 days post-inoculation (dpi). At 28 dpi, PWN-infected plants elicited with chitosan showed a sixfold lower nematode population when compared to non-elicited plants. Higher levels of MDA, catalase, carotenoids, anthocyanins, phenolic compounds, and lignin were detected in chitosan-elicited plants following infection. The expression levels of DEF gene were higher in elicited plants, while TRX and AFS expression was lower, possibly due to the disease containment-effect of chitosan. Combined, we conclude that chitosan induces pine defences against PWD via modulation of metabolic and transcriptomic mechanisms related with plant antioxidant system.info:eu-repo/semantics/publishedVersio
Source apportionment of PM2.5 in the pre-pandemic versus pandemic period in an area near Lisbon: lessons for air quality management
Trabalho apresentado em European Aerosol Conference - EAC2023, 3-8 setembro 2023, Málaga, EspanhaN/
Ser diplomado do ensino superior: escolhas, percursos e retornos
Textos selecionados a partir de comunicações apresentadas no 3.º Seminário
“Ser Diplomado do Ensino Superior: Escolhas, Percursos e Retornos”, realizado
pelo ObservatoriUM - Observatório dos Percursos Académicos dos Estudantes
da Universidade do Minho (Campus de Gualtar, 9 de junho de 2017).Este trabalho é financiado pelo CIEd - Centro de Investigação em Educação, projetos UID/CED/1661/2013 e UID/CED/1661/2016, Instituto de Educação,
Universidade do Minho, através de fundos nacionais da FCT/MCTES-PT.info:eu-repo/semantics/publishedVersio
A biorefinery from Nannochloropsis sp. microalga – Energy and CO2 emission and economic analyses
Are microalgae a potential energy source for biofuel production? This paper presents the laboratory results from a Nannochloropsis sp. microalga biorefinery for the production of oil, high-value pigments, and biohydrogen (bioH2). The energy consumption and CO2 emissions involved in the whole process (microalgae cultivation, harvest, dewater, mill, extraction and leftover biomass fermentation) were evaluated. An economic evaluation was also performed. Oil was obtained by soxhlet (SE) and supercritical fluid extraction (SFE). The bioH2 was produced by fermentation of the leftover biomass. The oil production pathway by SE shows the lowest value of energy consumption, 177-245 MJ/MJprod, and CO2 emissions, 13–15 kgCO2/MJprod. Despite consuming and emitting c.a. 20% more than the SE pathway, the oil obtained by SFE, proved to be more economically viable, with a cost of 365€/kgoil produced and simultaneously extracting high-value pigments. The bioH2 as co-product may be advantageous in terms of product yield or profit
Antibacterial electrospun PVA/Enzymatic synthesized poly(catechol) nanofibrous mid-layer membrane for ultrafiltration
Two different nanofibrous antibacterial membranes containing enzymatically synthesized poly(catechol) (PC) or silver nitrate (AgNO3, positive control) blended with poly(vinyl alcohol) (PVA) and electrospun onto a poly(vinylidene fluoride) (PVDF) basal disc to generate thin-film composite mid-layers were produced for water ultrafiltration applications. The developed membranes were thoroughly characterized in terms of morphology, chemical composition and general mechanical and thermal features, antimicrobial activity and ultrafiltration capabilities. The electrospun blends were recognized as homogeneous. Data revealed relevant conformational changes in the PVA side groups, attributed to hydrogen bonding, and high thermal stability and residual mass. PVDF+PVA/AgNO3 membrane displayed 100% growth inhibition of both Gram-positive and Gram-negative bacteria strains, despite the wide range of fiber diameters generated, from 24 to 125 nm, formation of numerous beads and irregular morphology. The PVDF+PVA/PC membrane showed a good growth inhibition of Staphylococcus aureus (92%) and revealed a smooth morphology, with no relevant bead formations and diameters ranging from 68 to 131 nm. The ultrafiltration abilities of the membrane containing PVA/PC were tested in a dead-end high-pressure cell (4 bar) using a reactive dye in distilled water and seawater. After 5 cycles, a maximum rejection of ≈ 85% with an average flux rate of 70 L m-2 h-1 for distilled water and ≈ 64% with an average flux rate of 62 L m-2 h-1 for seawater were determined with an overall salt rejection of ≈ 5%.This work was funded by FEDER funds through the Operational Competitiveness Programme – COMPETE and by National Funds through Fundação para a Ciência e Tecnologia (FCT) –under the project FCOMP-01-0124-FEDER-009389 (PTDC/CTM/100627/2008). A. Zille and H. P. Felgueiras also acknowledge funding from FCT within the scope of the project POCI-01-0145-FEDER-007136 and UID/CTM/00264.info:eu-repo/semantics/publishedVersio
Low-Cost Wearable Data Acquisition for Stroke Rehabilitation: A Proof-of-Concept Study on Accelerometry for Functional Task Assessment
Background: An increasingly aging society and consequently rising number of patients with poststroke-related neurological dysfunctions are forcing the rehabilitation field to adapt to ever-growing demands. Although clinical reasoning within rehabilitation is dependent on patient movement performance analysis, current strategies for monitoring rehabilitation progress are based on subjective time-consuming assessment scales, not often applied. Therefore, a need exists for efficient nonsubjective monitoring methods. Wearable monitoring devices are rapidly becoming a recognized option in rehabilitation for quantitative measures. Developments in sensors, embedded technology, and smart textile are driving rehabilitation to adopt an objective, seamless, efficient, and cost-effective delivery system. This study aims to assist physiotherapists’ clinical reasoning process through the incorporation of accelerometers as part of an electronic data acquisition system. Methods: A simple, low-cost, wearable device for poststroke rehabilitation progress monitoring was developed based on commercially available inertial sensors. Accelerometry data acquisition was performed for 4 first-time poststroke patients during a reach-press-return task. Results: Preliminary studies revealed acceleration profiles of stroke patients through which it is possible to quantitatively assess the functional movement, identify compensatory strategies, and help define proper movement. Conclusion: An inertial data acquisition system was designed and developed as a low-cost option for monitoring rehabilitation. The device seeks to ease the data-gathering process by physiotherapists to complement current practices with accelerometry profiles and aid the development of quantifiable methodologies and protocols.info:eu-repo/semantics/publishedVersio
Valorization of sugarcane by-products through synthesis of biogenic amorphous silica microspheres for sustainable cosmetics
Ashes from sugarcane by-product incineration were used to synthesize silica powders through alkaline hot extraction, followed by ethanol/acid precipitation or the sol–gel method. Both production methods allowed amorphous spherical silica microparticles with sizes ranging from 1–15 μm and 97% purity to be obtained. Water absorption ranged from 135–155 mL/100 g and 150–250 mL/100 g for precipitated silica and silica gel, respectively, while oil absorption ranged from 305 to 390 and from 250 to 350 mL/100 g. The precipitation with ethanol allowed the recovery of 178 g silica/kg ash, with a lab process cost of EUR 28.95/kg, while the sol-gel process showed a yield of 198 g silica/kg ash with a cost of EUR 10.89/kg. The experimental data suggest that ash from sugarcane by-products is a promising source to be converted into a competitive value-added product, minimizing the environmental impact of disposal problems.info:eu-repo/semantics/publishedVersio
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