Octupole Correlations in 145,146-Nd Nuclei

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

6-Amidinopurines as convenient precursors to pyrimido[5,4-d]pyrimidines for sar studies on Mycobacterium tuberculosis

Thanks are due to University of Minho and Fundação para a Ciência e Tecnologia for financial support (project nºF-COMP-01-0124-FEDER-022716 (ref. FCT PEst-/QUI/UI0686/2011) FEDER-COMPETE, FCT-Portugal and PhD grant awarded to Ana Bacelar SRFH/BD/24959/2005). The NMR spectrometer (Bruker 400 Avance III) is part of the National NMR Network supported with funds from FCT.nºF-COMP-01-0124-FEDER-02271

Compliance of publicly available mammographic databases with established case selection and annotation requirements

Mammographic databases play an important role in the development of algoritms aiming to improve Computer-Aided Detection and Diagnosis systems (CAD). However, these often do not take into consideration all the requirements needed for a proper study, previously discussed at the Biomedical Image Processin Meeting in 1993.info:eu-repo/semantics/publishedVersio

Quinoline-based hydrazone derivative as a biocide chemosensor: synthesis and sensing studies

Tributyltin (TBT) is an organic biocide used on antifouling paints to avoid biofouling on boats and submersed structures. It is toxic to a variety of aquatic organisms and was banned by the Rotterdam Convention in 1998. TBT sensing is an important issue as the biocide is still affecting aquatic environments as some countries did not sign the convention and are still using it. Currently, TBT monitoring methods are based on sampling and laboratory analysis, which is expensive, time-consuming, and require expert users. Therefore, a new simple and fast TBT sensing method would be of high interest. In this work, a new quinoline-based hydrazone derivative was synthesized by a condensation reaction in 67% yield. The new compound was characterized by the usual spectroscopic and spectrometric techniques. The preliminary chemosensory study of the hydrazone derivative in the presence of TBT in acetonitrile solution resulted in a color change from colorless to red together with the appearance of fluorescence. This interaction was confirmed by spectrophotometric and spectrofluorimetric titrations, which revealed that 17 equivalents of TBT led to the maximum optical signal in terms of fluorescence intensity and absorbance.This research was funded by Fundação para a Ciência e Tecnologia (FCT) and FEDER (European Fund for Regional Development)-COMPETE-QRENEU through the Chemistry Research Centre of the University of Minho (Ref. CQ/UM UID/QUI/00686/2020) as well as a PhD grant to R. P. C. L. Sousa (SFRH/BD/145639/2019)

Heterocyclic Aldehydes Based on Thieno[3,2-b]thiophene Core: Synthesis and Preliminary Studies as Ion Optical Chemosensors

Heterocyclic aldehydes show a variety of optical properties and the versatility of their reactivity allows them to yield a wide range of more complex compounds, with application in areas such as medicinal, materials and supramolecular chemistry. The biological and environmental relevance of certain molecules and ions turns them into targets for the design of molecular recognition systems. Recently, heterocyclic aldehydes have been reported in the literature as ion chemosensors. Following the group's work on optical chemosensors, for the detection and quantification of ions and molecules with environmental and medicinal relevance, this work reports the synthesis and characterization of two heterocyclic aldehydes based on the thieno[3,2-b]thiophene core, by Suzuki coupling, as well as the synthesis of the corresponding precursors. Preliminary chemosensory studies for the synthesized heterocyclic aldehydes in the presence of selected cations were also performed, in solution, in order to determine their potential application as optical chemosensors

PDMS based hybrid sol-gel materials for sensing applications in alkaline environments: synthesis and characterization

Nowadays, concrete degradation is a major problem in the civil engineering field. Concrete carbonation, one of the main sources of structures’ degradation, causes concrete’s pH to decrease; hence, enabling the necessary conditions for corrosion reinforcement. An accurate, non-destructive sensor able to monitor the pH decrease resistant to concrete conditions is envisaged by many researchers. Optical fibre sensors (OFS) are generally used for concrete applications due to their high sensitivity and resistance to external interferences. Organic-inorganic hybrid (OIH) films, for potential functionalization of OFS to be applied in concrete structures, were developed. Polydimethylsiloxane (PDMS) based sol-gel materials were synthesized by the formation of an amino alcohol precursor followed by hydrolysis and condensation. Different ratios between PDMS and (3-aminopropyl)triethoxysilane (3-APTES) were studied. The synthesized OIH films were characterized by Fourier-transformed infrared spectroscopy (FTIR), UV–Vis spectroscopy, electrochemical impedance spectroscopy (EIS) and thermogravimetric analysis (TGA). The OIH films were doped with phenolphthalein (Phph), a pH indicator, and were characterized by UV–Vis and EIS. FTIR characterization showed that the reaction between both precursors, the hydrolysis and the condensation reactions occurred successfully. UV–Vis characterization confirmed the presence of Phph embedded in the OIH matrices. Dielectric and thermal properties of the materials showed promising properties for application in contact with a high alkaline environment.This research was funded by the Program Budget COMPETE—Operational Program Competitiveness and Internationalization—COMPETE 2020, and the Lisbon Regional Operational Program (its FEDER component), and by the budget of FCT Foundation for Science and Technology, I.P, grant number POCI-01-0145-FEDER-031220

Amino-alcohol organic-inorganic hybrid sol-gel materials based on an epoxy bicyclic silane: synthesis and characterization

Organic-inorganic hybrids (OIHs) are a type of material that can be obtained using the sol-gel process and has the advantages of organic and inorganic moieties in a single material. Polyetheramines have been widely used in the preparation of this type of material, particularly in combination with epoxy-based alkoxysilanes. Nevertheless, epoxyciclohexylethyltrimethoxysilane (ECHETMS) is a promising alkoxysilane with an epoxy terminal group that is quite unexplored. In this work, four novel OIH materials were synthesized using the sol-gel method. The OIHs were based on Jeffamines® of different molecular weights (D-230, D-400, ED-600, and ED-900), together with ECHETMS. The materials were characterized using multinuclear solid state NMR, FTIR, BET, UV/Vis spectroscopy, EIS, and TGA. The influence of the Jeffamine molecular weight and the suitability of these materials to act as a supporting matrix for heteroaromatic probes were assessed and discussed. The materials show interesting properties in order to be applied in a wide range of sensing applications.This research was funded by Fundação para a Ciência e Tecnologia (FCT) and FEDER (European Fund for Regional Development)-COMPETE-QRENEU for financial support through the Chemistry Research Centre of the University of Minho (Ref. CQ/UM (UID/QUI/00686/2019 and UID/QUI/00686/2020), project “SolSensors—Development of Advanced Fiber Optic Sensors for Monitoring the Durability of Concrete Structures”, reference POCI-01-0145-FEDER-031220, and a PhD grant to R.P.C.L. Sousa (SFRH/BD/145639/2019). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network (PTNMR) and are partially supported by Infrastructure Project No 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC)