Artigos em revistas internacionais
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Browsing Artigos em revistas internacionais by Field of Science and Technology (FOS) "Ciências Médicas::Biotecnologia Médica"
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- Enhanced alpha-amylase inhibition activity of amine-terminated PAMAM dendrimer stabilized pure copper-doped magnesium oxide nanoparticlesPublication . Jeevanandam, Jaison; Gonçalves, Mara; Castro, Rita; Gallo, Juan; Bañobre-López, Manuel; Rodrigues, João; Gonçalves, Mara; Castro, Rita; Rodrigues, JoãoThe present work aims to prepare copper-doped MgO nanoparticles via a sol-gel approach and study their antidiabetic alpha-amylase inhibition activity with undoped MgO nanoparticles. The ability of G5 amine terminated polyamidoamine (PAMAM) dendrimer for the controlled release of copper-doped MgO nano particles to exhibit alpha-amylase inhibition activity was also evaluated. The synthesis of MgO nanoparticles via sol-gel approach and optimization of calcination temperature and time has led to the formation of nanoparticles with different shapes (spherical, hexagonal, and rod-shaped) and a polydispersity in size ranging from 10 to 100 nm with periclase crystalline phase. The presence of copper ions in the MgO nanoparticles has altered their crystallite size, eventually modifying their size, morphology, and surface charge. The efficiency of dendrimer to stabilize spherical copper-doped MgO nanoparticles (ca. 30 %) is higher than in other samples, which was confirmed by UV–Visible, DLS, FTIR, and TEM analysis. The amylase inhibition assay emphasized that the dendrimer nanoparticles stabilization has led to the prolonged enzyme inhibition ability of MgO and copper doped MgO nanoparticles for up to 24 h.
- Microextraction techniques for antibiotics surveillance in the food chain and environmentPublication . Antos, Joanna; García-Cansino, Laura; Ángeles García, María; Ginter-Kramarczyk, Dobrochna; Marina, María Luisa; Zembrzuska, Joanna; Câmara, José Sousa; Pereira, Jorge A. M.; Câmara, José; Augusto Machado Pereira, JorgeAntibiotics are commonly used to prevent and treat infections in human medicine, animal farming, and aqua culture. However, their excessive use can result in the development of antibiotic resistance and the presence of antibiotic residues in the food and environment. Therefore, it is essential to monitor antibiotic use and assess resistance, but the lack of standardisation and long-term quantitative data on antibiotic usage in different animal species is very challenging. Sample preparation techniques, such as solid-phase extraction (SPE) and liquid-liquid extraction (LLE), have been widely used, but they have limitations, including the need for large sample volumes, organic solvents, and complex and labourious protocols. Microextraction techniques (μExT) that align with the principles of Green Analytical Chemistry have gained attention in recent decades. Depending on the type of μExT used and the target analytes, the amounts of solvents, reagents, and samples used can be reduced by up to ten times or more. Often, the extraction time is also shortened by several orders of magnitude, labware requirements are much lower, and the analytical hardware can be simplified without compromising acceptable analytical performance. Notably, this includes the substitution of expensive LC-MS configurations with LC-UV or FLR cheaper equipment and detection systems. Greener solvents, such as ionic liquids (IL), supramolecular solvents (SUPRAS), and deep eutectic solvents (DES), have also been reported, further contributing to the development of more sustainable and environmentally friendly antibiotic extraction and analytical procedures. The AGREE tool metrics shows that substitution of conventional extraction approaches with μExT enables a greener profile for any methodology developed to analyse antibiotics in different food and environmental samples. This article provides a detailed overview of the advantages of using different μExT to monitor antibiotic usage in the food industry and environment and discusses the challenges and opportunities in this field.