1,432 research outputs found

    In vitro assessment of the synergism between extracts of Zanthoxylum zanthoxyloides and Zanthoxylum leprieurii and some standard antibiotics

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    Research ArticlePurpose: To survive in harsh environments, plants developed functional and metabolic adaptive mechanisms. One of the most relevant defense strategies is the biosynthesis of secondary metabolites, including terpenoids, alkaloids, flavonoids, and phenolics that are accumulated in cellular organelles or secretory structures. Hence, plants are recognized as a valuable source of natural products and for thousands of years very diverse herbal formulations were created to treat several diseases. Zanthoxylum zanthoxyloides and Zanthoxylum leprieurii, two Rutaceae species native to Guinea-Bissau, are well known for their ethnopharmacological relevance. Methods: In the present study, the in vitro antimicrobial activity of these plants against human pathogens was assessed and the phytochemical profile was screened. The extracts of roots and young leaves were obtained by sequential extraction of increasing polarity (n-hexane, CH2Cl2, EtOAc, MeOH and H2O) and tested against Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined, as well as the evaluation of the synergic potential of the extracts. Results: Z. leprieurii leaves extracts, the most apolar ones, had the highest antimicrobial activity, being able to inhibit the growth of Enterococcus hirae and all the Staphylococcus strains assayed, including the resistant ones. A synergic effect between the Zanthoxylum species extracts and standard antibiotics was found, reverting the activity of resistant strains. The phytochemical screening revealed the presence of terpenes, flavonoids, and phenolic compounds, known to have antibacterial properties. Conclusions: The obtained results point to the validation of their use in tradition medicine and emphasize the worthwhile of additional studies of these species to better understand the compounds and mechanisms that may be valuable to restore antibacterial activityinfo:eu-repo/semantics/publishedVersio

    Inhibition-based biosensor for cyanide detection – a preliminary study

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    Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio

    Green roofs as an urban NBS strategy for rainwater retention: influencing factors - a review

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    There has been a rapid development in studies of nature-based solutions (NbS) worldwide, which reveals the potential of this type of solution and the high level of interest in its implementation to improve the resilience of cities. Much relevant information and many important results are being published, and it is now possible to see their diverse benefits and complexity. Several authors highlight their role in urban areas not just in temperature control, but also in human health, ecosystem development and water management. However, in the current reality of cities, where water use is being (and will be) constantly challenged, analyzing NbS advantages for the urban water cycle is crucial. This study performed an intense review of the NbS literature from 2000 to 2021, to identify their contributions to the improvement of urban water cycle management and thus provide a solid information base for distinct entities (public institutions, private investors and the urban population in general) to disseminate, apply and justify their implementation. In general terms, the urban water cycle embraces not only the abstraction of water for urban consumption, but also its return to nature and all the stages in between, including water reuse and stormwater management. This review will highlight the important benefits that NbS in general, and green roofs in particular, provide to urban stormwater control, a key factor that contributes to urban sustainability and resilience in order to face future climate challenges. The novelty of the present review paper falls within the conclusions regarding the crucial role that NbS develop in urban water management and the main features that must be tested and technically enhanced to improve their functioning.info:eu-repo/semantics/publishedVersio

    Bone mineral density in children submitted to dairy restriction

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    Simultaneous effect of irradiance and temperature on biochemical composition of the microalga Pavlova lutheri

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    The biochemical composition of microalgae can be modulated through the environmental conditions prevailing during growth. The simultaneous effects of irradiance and temperature on the biochemical composition of Pavlova lutheri were evaluated using an experimental star factorial design. Five levels were tested for each parameter (temperature, 10, 14, 18, 22 and 26°C; irradiance, 60, 105, 150, 195 and 240 μmol photons m−2 s−1), whereas the carbohydrate, protein, lipid, pigments and elementary compound contents were measured as response variables. Additionally, in order to rapidly measure parameters to define the status of the culture, the validation of the relationships between biochemical parameters and physiological status were estimated through regression analysis. It was observed that irradiance and temperature play a major role in the determination of the biochemical composition of microalgae. Their effects are synergistic, and it can be observed that a trend in behaviour at a certain temperature can be reversed at a different temperature; therefore, when selecting the environmental conditions to a culture they must be studied in a combined fashion. Although there are consistent relationships between pigment contents and elementary compounds in cells, its linearity is influenced by the irradiance of the culture and its age; therefore, they can only be applied in specific circumstances. On the other side, population biomass was well estimated in terms of carotenoid content, irrespective of the environmental conditions provided and the growth phase

    Perceived cognitive functioning in breast cancer patients treated with chemotherapy compared to matched healthy women: evidence from a Portuguese study

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    Aim: Cognitive concerns are one of the most frequently reported symptoms by breast cancer survivors. This study aimed to evaluate perceived cognitive functioning in Portuguese women with breast cancer treated with chemotherapy. Methods: A cross-sectional study enrolling 146 women (73 with breast cancer and 73 healthy) was conducted from August to October 2017, invited to participate through online dissemination. Participants completed self-reported questionnaires to collect sociodemographic and clinical data and assess perceived cognitive functioning and psychological adjustment variables (anxiety and depression). Results: Compared to healthy women, women with breast cancer showed significantly lower scores on the Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog) subscales and higher levels of depression. Both groups showed significant negative correlations between perceived cognitive functioning and anxiety and depression. Health status and depression seem to better explain perceived cognitive functioning, with health status adding significantly more explained variance beyond sociodemographic and psychological adjustment variables. Conclusion: The current findings provide evidence for the existence of more cognitive complaints among Portuguese women with breast cancer, compared to healthy individuals. Anxiety, depression, age and education also explain perceived cognitive functioning. Considering that health status and psychological adjustment seem to significantly explain perceived cognitive functioning, special attention should be given by health-care professionals, including nurses, to designing clinical interventions for breast cancer patients to help manage cognitive impairment.Foundation for Science and Technology SFRH/BD/138785/2018.info:eu-repo/semantics/publishedVersio

    Textile-based pressure sensors for step detection: a preliminary assessment

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    This paper presents the development and performance assessment of textile-based sensor based on a three layer architecture for the step detection. Two different transducing elements (EeonTex™ LG-SLPA and velostat) and electrodes (Satatex Techniktex P-130 and Elitex yarns) were selected for the construction of the sensors. The performance of the resulting sensors was assessed based on a dynamometer cyclic compression/decompression test with different compressions loads and at different speeds. Additionally, a real-life experiment was conducted to evaluate the sensor response during walking. The results show that all sensors configurations have a non-linear resistance-force relation. The best sensor configuration for the step detection was the combination of EeonTex™ LG-SLPA as a transducing element and the Elitex yarns for the electrodes. In this configuration, the resistance magnitude varies in an order of hundreds of kohms between the stance and the swing phases.This work was partially financed by FEDER funds through the Competitively Factors Operational Programme—COMPETE and by national founds through FCT -Foundation for Science and Technology within the scope of Project POCI-01-0145-FEDER-007136 and Project PEstOE/EEI/UI0319/2014. Authors would like to thanks André Paiva and Sérgio Branco for their collaboration in sensors production and data acquisition, respectively.info:eu-repo/semantics/publishedVersio
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