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Browsing by Issue Date, starting with "2019-08-15"

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  • Infusions and decoctions of dehydrated fruits of Actinidia arguta and Actinidia deliciosa: Bioactivity, radical scavenging activity and effects on cells viability
    Publication . Silva, Ana Margarida; Pinto, Diana; Fernandes, Iva; Albuquerque, Tânia Gonçalves; Costa, Helena S.; Freitas, Vitor; Rodrigues, Francisca; Oliveira, M. Beatriz P.P.
    Actinidia deliciosa and A. arguta fruits (kiwifruit and kiwiberry, respectively) are an excellent source of bioactive compounds. The aim of this paper is to valorize the fruits that are not commercialized (e.g. due to inadequate size or physical damage) in infusions and decoctions. The antioxidant activity, the scavenging activity against reactive species, the phenolic profile and the intestinal effects of infusions and decoctions of dehydrated fruits were evaluated and compared. Decoctions presented the highest antioxidant activity and a good ability to capture HOCl and NO. The phenolic composition of A. arguta present quinic acid, cis-caftaric acid and its derivatives, caffeoyl hexoside, luteolin glucuronide, quercetin derivatives and myristin, while A. deliciosa extracts were characterized by the presence of quinic acid, caffeic acid and its derivatives and caffeoyl hexoside. No adverse effects were observed on Caco-2 and HT29-MTX cells. Kiwiberry decoctions showed to be the best option to keep the fruits benefits.
    2019-08-15Journal article Open access Show more
  • Disposable electrochemical immunosensor for analysis of cystatin C, a CKD biomarker
    Publication . LOPES, Paula; Costa Rama, Estefanía; Beirão, Idalina; Nouws, Henri; Santos-Silva, Alice; Delerue-Matos, Cristina
    Specific monitoring of cystatin C (CysC) levels in biological fluids is critical for diagnosis, treatment and mechanistic understanding of a spectrum of diseases, particularly chronic kidney disease (CKD). Despite evidences that CysC correlates with the high risk and/or progression of CKD, its use in clinical practice is still scarce. In this context, we report the development of a simple and sensitive immunosensor for the detection of CysC. The biosensor combines the technology of cost-effective screen-printed electrodes with the high specificity of a sandwich immunoassay. Optimized conditions showed that the sensor operates in a linear range between 10 and 100 ng mL-1, with a detection limit and a sensitivity of 6.0 ng mL-1 and 6.4 ± 0.3 μA ng mL-1 cm-2, respectively. Moreover, the sensor provided precise results (RSD ≤ 6.2%) and the quantification of CysC in CKD serum samples revealed to be in agreement with the values obtained by a particle-enhanced nephelometric immunoassay. In this light, the proposed immunosensor qualifies for clinical application, constituting a step forward in the development of fast, sensitive and cost-effective diagnostic tools that can improve the current medical care settings of CKD patients.
    2019-08-15Journal article Open access Show more