Definição e Modelação Hidráulica do Controlo por Montante à Distância numa Rede de Canais com Reservatórios Associados

O controlo por jusante à distância em canais de distribuição de água permite uma resposta eficiente e automática às variações de caudal ao nível dos utentes. A profundidade controlada é a da secção mais a jusante de cada um dos trechos de canal considerado. O órgão de controlo é a comporta de admissão ao mesmo trecho, o que permite alguma antecipação na acção de controlo e, consequentemente, uma melhoria da qualidade da resposta, em relação ao “tradicional” controlo local por montante. Na aplicação em estudo (Infra-estrutura 12 do Alqueva), o sistema hidráulico é constituído por uma rede ramificada de canais que terminam em grandes reservatórios que, por sua vez, alimentam blocos de rega com distribuição de água a pedido. As variáveis a controlar são as cotas de superfície livre nos reservatórios (albufeiras) e a montante das comportas planas automáticas que equipam o canal principal e os canais de derivação. No artigo, dá-se conta do trabalho realizado na definição e calibração do modelo de controlo do tipo Proporcional e Integral (PI) usado para este sistema hidráulico de relativa complexidade. As cotas de referência nas albufeiras têm em conta os valores mínimos de exploração e as cotas de pleno armazenamento, sendo as condições de fronteira de jusante do modelo hidráulico, que é usado como simulador numérico de todo o sistema hidráulico. Os sifões invertidos existentes no interior do sistema hidráulico e a redução da capacidade de transporte deste para determinadas cotas de armazenamento das albufeiras tornaram particularmente difícil a calibração do modelo de controlo. Para além da calibração dos controladores, o artigo apresenta ainda um conjunto de simulações que visa a definição dos limites de funcionamento do sistema e sua análise para determinados cenários de operação

A utilização das redes sociais em recrutamento e seleção

Mestrado em Gestão de Recursos HumanosA globalização do mercado de trabalho, associada ao desenvolvimento das tecnologias de informação e comunicação, nomeadamente a utilização crescente das redes sociais, alterou significativamente as práticas de recrutamento e seleção. Com o propósito de identificar em que medida e de que modo estão a ser utilizadas as redes sociais no recrutamento e seleção, bem como as principais vantagens e desvantagens da sua utilização, foi realizado um estágio numa empresa de recrutamento e seleção, presente em diversas redes sociais. Este relatório dá conta das atividades desenvolvidas no âmbito do referido estágio na área do recrutamento e seleção bem como da utilização que é dada às redes sociais na empresa de acolhimento. No final do relatório é efetuada uma reflexão crítica tendo por base a revisão de literatura efetuada sobre o tema e a realidade encontrada na empresa em estudo. O LinkedIn é a rede social mais utilizada para recrutamento e seleção, sendo que o Facebook é essencialmente utilizado para divulgação ocasional de oportunidades profissionais e atividades de employer branding.The globalization of the labour market, in pair with the development of information and communication technologies, specifically the growing use of social networks, changed significantly the recruitment and selection practices and procedures. With the aim to identify in what measure social networking websites are being used in recruitment and selection, as well as the main advantages and disadvantages, it was completed an internship in a recruitment and selection organization, with presence in several social networking sites (SNS). In this report will be stated the activities developed in the internship, in the recruitment and selection area, along with the specification on the usage of the SNS in the organization. To sum up, it is presented a critical reflection that takes into consideration the literature review regarding the chosen topic and the reality of the organization. LinkedIn is the most popular SNS, and Facebook is essentially used to occasionally share professional opportunities and employer branding activities.info:eu-repo/semantics/publishedVersio

Optimizing Cancer Treatment through Modulation of Redox Balance

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Evaluation of diterpenoids from P. ornatus as potential COX-1 inhibitors

Natural products are a rich source of drug candidates for clinical use. The Plectranthus ornatus Codd. belongs to a genus associated to the isolation of diterpenoids which are responsible for various biological activities. The three diterpenoids under study were isolated in the past from P. ornatus and are now being evaluated as potential COX-1 inhibitors. Obtained results suggest that rhinocerotinoic acid (2), but not halimane (3) and plectrornatin C (1), has a mild COX-1 inhibitory activity. Current studies are being carried out to understand if these compounds have effect as COX-2 inhibitors. This will contribute to establish their possible interest as anti-inflammatory agents

In vitro assessment of antimicrobial, antioxidant, and cytotoxic properties of Saccharin-Tetrazolyl and-Thiadiazolyl derivatives: the simple dependence of the pH value on antimicrobial activity

The antimicrobial, antioxidant, and cytotoxic activities of a series of saccharin-tetrazolyl and -thiadiazolyl analogs were examined. The assessment of the antimicrobial properties of the referred-to molecules was completed through an evaluation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against Gram-positive and Gram-negative bacteria and yeasts. Scrutiny of the MIC and MBC values of the compounds at pH 4.0, 7.0, and 9.0 against four Gram-positive strains revealed high values for both the MIC and MBC at pH 4.0 (ranging from 0.98 to 125 µg/mL) and moderate values at pH 7.0 and 9.0, exposing strong antimicrobial activities in an acidic medium. An antioxidant activity analysis of the molecules was performed by using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, which showed high activity for the TSMT (N-(1-methyl-2H-tetrazol-5-yl)-N-(1,1-dioxo-1,2-benzisothiazol-3-yl) amine, 7) derivative (90.29% compared to a butylated hydroxytoluene positive control of 61.96%). Besides, the general toxicity of the saccharin analogs was evaluated in an Artemia salina model, which displayed insignificant toxicity values. In turn, upon an assessment of cell viability, all of the compounds were found to be nontoxic in range concentrations of 0-100 µg/mL in H7PX glioma cells. The tested molecules have inspiring antimicrobial and antioxidant properties that represent potential core structures in the design of new drugs for the treatment of infectious diseases.Funding Agency Portuguese Foundation for Science and Technology UID/QUI/00100/2019 UID/MULTI/04326/2019 -CCMAR Portuguese Foundation for Science and Technology SFRH/BPD/99851/2014 IST-ID/115/2018info:eu-repo/semantics/publishedVersio

The teas of Portuguese centenarians

Copyright © 2019 Elsevier Inc. All rights reserved.Introduction: Medicinal plants traditional consumption habits, can contribute to longevity. Methods: A sample of 253 centenarian individuals in Portugal, both sexes, median age 100 years, was studied, to verify past habits in relation to medicinal-interest plants use. It was compared with a control group median age 67 year, with a reduced theoretical probability of reaching 100 years. Results: Among the 8 most cited plants, in decreasing frequency order, in centenarian's group: Lemon-balm, barley, lemon-verbena, orange (leaf-flower), linden, whig-plant, pennyroyal and mount-carqueja (Pterospartum-tridentatum); in the control group: Lemon-balm, lemonverbena, chamomile, linden, prince-herb, green-tea, lemon-tea and minttea. Whereas 28% of the control subjects reported not using infusion plants, in the centennial group, only 9.1% reported not routinely use them (χ2¼30,42, po0.001). Among the 8 plants most marked by the centenarians that were not mentioned by the controls, they include barley, whig-plant, pennyroyal and mount-carqueja. Conclusion: the high antioxidant power associated with the use of plants by centenarian individuals, determined by anti-free radical's activity, lipoperoxidation inhibition and antitumor potential, may have contributed to their exceptional longevity.info:eu-repo/semantics/publishedVersio

Centauri honey: a promising medicinal ingredient?

Honey is a natural product that has been used over the centuries as a medicine due to its biological activities. Centauri Cave Nymph Honey is a Cave honey extracted from 2500 meters high altitude above sea level from a deep cave by professional speleologists and is located at Caucasus Mountains of Turkey. The Apis mellifera Caucasica bee colony is located 50 kilometers away from human residences, ensuring its isolation from other colonies and maintaining a varroa mite-free status. The aim of this work is to analyze the physicochemical parameters and the bioactivity of Centauri honey. The physiochemical parameters that have been examined include color, moisture content, conductivity, pH, acidity, HMF (5-hydroxymethylfurfural), diastase index, and proline. In addition, it was also evaluated the ash, protein, sugars, carbohydrates, and energy. The biological activity was evaluated through the antioxidant (TBARS), antimicrobial activities and cytotoxicity in different cell lines (AGS, CaCo-2, MCF-7, NCI-H460, PLP2, HFF-2, and HaCat), and anti-inflammatory activity (RAW 264.7 macrophages). Ongoing research is focusing on the potential protetive effects of consuming Centauri Cave Honey against lung and prostate cancers. In vivo studies are expected to shed more ligt on the additional health benefits that this honey may offer.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2021).info:eu-repo/semantics/publishedVersio

Medicinal centauri honey: a promising ingredient?

Honey is a natural product with antioxidant and antimicrobial properties, has been used as a medicinal substance for centuries. Thisnatural product is main- ly composed of a supersaturated solution of sugars, containing low water con- tent and trace amounts of bioactive compounds. The flower source, climate, geographical origin, harvesting process and storage conditions are factors that influence the composition of the nectar, leading to significant changes in the chemical composition, physical properties, and bioactivity of honey1. Centau- ri Honey is harvested from bee colonies located in the wild Alps of Turkey ́s mountainous region, approximately 2,500 meters above the Black Sea. The bees live in caves far from human settlements and other bees, and they have access to medicinal endemic blooms throughout the year. The aim of this work was to investigate the quality, physicochemical, nutrition- al parameters, and bioactivity of honey. The quality and physiochemical pa- rameters was analysed by colour, moisture content, conductivity, pH and acidity, 5-HMF (5-Hydroxymethylfurfural), diastase index and proline. The nutritional values were determined assessing ash, protein content, sugars, carbohydrates and energy. The biological activity was evaluated through the antioxidant, antimicrobial activity (broth microdilution method) and cytotox- icity in cell lines (AGS, CaCo-2, MCF-7, NCI-H460, PLP2, HFF-2, and HaCat), and anti-inflammatory activity (using RAW 264.7 macrophages). Further studies are ongoing to scientifically validate the medicinal properties of Centauri Honey due to its exceptional chemical composition and thus to become an innovative Ingredient.info:eu-repo/semantics/publishedVersio

Enhanced anticancer activity of Hymenocardia acida stem bark extract loaded into PLGA nanoparticles

Hymenocardia acida (H. acida) is an African well-known shrub recognized for numerous medicinal properties, including its cancer management potential. The advent of nanotechnology in delivering bioactive medicinal plant extract with poor solubility has improved the drug delivery system, for a better therapeutic value of several drugs from natural origins. This study aimed to evaluate the anticancer properties of H. acida using human lung (H460), breast (MCF-7), and colon (HCT 116) cancer cell lines as well as the production, characterization, and cytotoxicity study of H. acida loaded into PLGA nanoparticles. Benchtop models of Saccharomyces cerevisiae and Raniceps ranninus were used for preliminary toxicity evaluation. Notable cytotoxic activity in benchtop models and human cancer cell lines was observed for H. acida crude extract. The PLGA nanoparticles loading H. acida had a size of about 200 nm and an association efficiency of above 60%, making them suitable to be delivered by different routes. The outcomes from this research showed that H. acida has anticancer activity as claimed from an ethnomedical point of view; however, a loss in activity was noted upon encapsulation, due to the sustained release of the drug.info:eu-repo/semantics/publishedVersio