83 research outputs found

    Rational design of multi-functional nanomaterials

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    FCT-MEC project PTDC/QEQMED/2118/2014publishersversionpublishe

    Impacts of environmental issues on health and well-being: a global pollution challenge

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    Every 2 years, the environmental, chemical, and health research communities meet in Costa de Caparica, Portugal to showcase the latest technologies, methodologies and research advances in pollution detection, contamination control, remediation, and related health issues. Since its inception in 2015, the International Caparica Conference on Pollution Metal Ions and Molecules (PTIM) has become a biennial global forum to hear from those who protect the land, the water, and the air at all environmental scales. During past PTIM editions, we have learned about numerous efforts to develop new recovery and clean-up processes to restore the natural equilibria of our planet. Soil, land, water, and air are the key focus of efforts that will require deeper understanding and better control.publishersversionpublishe

    Development of Cyanine 813@Imidazole-Based Doped Supported Devices for Divalent Metal Ions Detection

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    PM003/2016 IF/00007/2015 CEECIND/00648/2017A NIR cyanine@imidazole derivative Cy1 was synthesized and evaluated as a metal ion sensor in solution. Cy1 was shown to be very sensitive to all metal ions tested, presenting a blue shift in the absorption from 668 nm to 633 nm, followed by a change in colour from pale green to blue with Zn2+, Cd2+, Co2+, Ni2+ and Hg2+ ions. Despite the blue shift in the absorption, a decrease at 633 nm (with a colour change from pale green to colourless), as well as a quenching in the emission intensity at 785 nm were observed for Cu2+ ions. The results show the formation of sandwich complexes of two ligands per metal ion with the highest association constant observed for Cu2+ (Log Kass.abs = 14.76 ± 0.09; Log Kass.emis. = 14.79 ± 0.06). The minimal detectable amounts were found to be 31 nM and 37 nM, with a naked eye detection of 2.9 ppm and 2.1 ppm for Hg2+ and Cu2+ ions, respectively. These results prompted us to explore the applicability of Cy1 by its combination with nanomaterials. Thus, Cy1@ doped MNs and Cy1@ doped PMMA nanoparticles were synthesized. Both nanosystems were shown to be very sensitive to Cu2+ ions in water, allowing a naked-eye detection of at least 1 ppm for Cy1@ doped MNs and 7 ppm for Cy1@ doped PMMA. This colourimetric response is an easy and inexpensive way to assess the presence of metals in aqueous media with no need for further instrumentation.publishersversionpublishe

    Timely and effectively profile bacteria in cystic fibrosis lungs

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    Bacterial lung infections are typical of cystic fibrosis (CF) disease due to accumulation of airway mucus. Despite the use of aggressive antibiotic therapy, the mortality rate of CF patients is still high. Unsuccessful bacterial eradication is often due to several evolutional strategies adopted by bacteria to achieve anaerobic or microaerophilic adaptation and antibiotic resistance, such as biofilm formation and phenotypic switching. By triggering these strategies, bacteria have the potential to better survive to airway stressful conditions, without the fitness costs of irreversible mutations. Indeed, phenotypic switching provides a source of microbial diversity through interchange between phenotypic states, analogue to a mechanism ON/OFF. This interchange of states, often visible in terms of colony morphology, can have serious impact on bacterial virulence, antimicrobial resistance and persistence1. However, the specific correlation between some colony traits and the biological impact is unknown. This study was designed to inspect P. aeruginosa and S. aureus colony phenotypic alterations, particularly morphology changes, by visual inspection, and protein profiles by MALDI MS, and correlate them with some virulence determinants expression and antibiotic susceptibility profiles. The visual identification of colony morphologies was supported by a novel, in-house developed identification system, ColMIS2. MALDI MS profiling grouped colony morphotypes differently from conventional morphological classification and antibiotic susceptibility. However, MALDI MS colony differentiation seems to match with changes in some virulence factors expressed by the different bacterial morphotypes, such as the increase of flagella, swarmer cell differentiation, ability to form biofilm and toxin production. Despite exhibiting distinct colony morphologies, the variants grouped by MALDI shared a common morphological feature, the heterogeneity of colony surface (more than one type of texture). Therefore, these data seems to indicate that MALDI MS clustered colony variants according their virulence that can be inspected by just the heterogeneous surface of the colonies, than the whole morphology. However, this association have to be deeper studied, since other colonies with heterogeneous surfaces were differentially clustered by MALDI MS and, despite decreased virulence, exhibited high resistance to in-use antibiotics. These results highlighted the potential and the need of using a combination of proteomic high-throughput screening of pathogenic bacteria with culturing and physiologic methods to reach a comprehensive understanding of the virulence and antibiotic resistance. Efforts are already underway to develop a new tool based on combinatorial methodologies to help clinical diagnosis and medical decision support, as well the design of new therapeutic strategies. Acknowledgments: The financial support from IBB-CEB and FCT and European Community fund FEDER, through Program COMPETE (FCT PTDC/SAU-SAP/113196/2009/ FCOMP-01-0124-FEDER-016012) and Ana Margarida Sousa PhD Grant (SFRH/BD/72551/2010) are gratefully acknowledged

    2,2'-(2,2'-oxybis(ethane-2,1-diyl)bis(oxy))bis(N-(2,2'-bithiophen-5-ylmethylene)aniline)

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    We would like to thank Xunta de Galiza (Spain) for project 09CSA043383PR and the University of Vigo, Vicou for projects INOU UVIGO/VICOU/K914-122P64702/2009 and UVIGO/VICOU/K912-122P64702/2009. Thanks to the FCT-MCTES/FEDER (Portugal) through national projects POCI/QUI/55519/2004 and PDTC/QUI/66250/2006. B. P thanks FCT/Portugal for the PhD Grant SFRH/BD/27786/2006. C.L. and J.L. thank Xunta de Galicia for the Isidro Parga Pondal Research Program.A new flexible fluorescent compound L derived from 1,5-bis(2-aminophenoxy)-3-oxapentane (A) has been synthesized by classical Schiff-base reaction between (A) and 2,2 ́-bithiophene carbaldehyde (B). The same synthesis was reproduced by a green methodology using an ultrasonication reaction in a classical sonication bath. The structure of the new compound was confirmed by elemental analysis, IR, 1H-NMR, MALDI-TOF-MS and EI-MS-spectra, UV-vis and fluorescence emission spectroscopy.publishersversionpublishe

    Synthesis, characterization and spectroscopic studies of two new schiff-base bithienyl pendant-armed 15-crown-5 molecular probes

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    Nickel(II); Palladium(II); Mercury(II); Sodium(I); ; Crown ether, Schiff base, LuminescenceTwo new ligands provided with a 15-crown-5 as receptor unit and bithiophen unit as emissive probe have been synthesized and characterized in order to evaluate the coordination capabilities and their sensor effect. Ligand L1 presents an aromatic crown ether moiety directed linked to the imine-2,2´-bithiophene π–conjugated system and ligand L2 is constituted by an aliphatic crown ether moiety linked to the same imine-2,2´-bithiophene system through a methylene unit. Solid metal complexes of Ni(II), Pd(II), Hg(II) and Na(I) have been synthesized using both macrocyclic compounds, and have been studied in solution in the presence of the same metal ions. All solid compounds have been characterized by common analytical and spectroscopic techniques. The sensorial effect has been studied using absorption, emission and MALDI-TOF-MS spectroscopies.Fundação para a Ciência e a Tecnologia (FCT
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