183 research outputs found

    Organic–inorganic hybrid sol–gel material loaded with an heterocyclic aldehyde with potential application for Cu(II) detection

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    Organic–inorganic hybrids (OIH) are a versatile type of material that joins organic and inorganic moieties in a polymeric matrix and can be easily synthesized by the sol–gel method. OIH can be doped with chemosensors to yield an ion-sensitive polymeric matrix that can be used in the design of a more complex sensory device. Heterocyclic aldehydes show promising optical properties for supramolecular interactions with different ions through molecular recognition and changes in the optical signal. Cu(II) is a cation with biological and environmental relevance, being an appealing target for the design of chemosensors. Considering the group’s work on OIH materials and heterocyclic chromophores/fluorophores, this study reports the synthesis and characterization of an OIH based on Jeffamine THF-170 and 3-isocyanatopropyltriethoxysilane (3-ICPTES), doped with a previously synthesized heterocyclic aldehyde that features a naked-eye detection of Cu(II). Additionally, the OIH material shows color changes in the presence of Cu(II). Therefore, the obtained material shows promising properties to be used in the development of an optical fiber sensor for Cu(II) detection

    New dinitrophenyl hydrazones as colorimetric probes for anions

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    Anion sensing is a dynamic research field due to biological and environmental importance of some organic or inorganic anions. Hydrazones show promising properties in the design of anion chemosensors due to the presence of proton donor and acceptor sites in their structure. In this work, two novel dinitrophenyl hydrazones, functionalized with a quinoline moiety were synthesized and characterized by spectroscopic and spectrometric techniques. The interaction between the new compounds 3a-b with different organic and inorganic anions was assessed. The two compounds showed a change of color from light yellow to magenta in the presence of H2PO4-, CH3COO-, BzO-, CN-, and F-. The interactions were analyzed by spectrophotometric titrations and the stoichiometry of the interaction was assessed by the method of continuous variation. Compound 3b showed a remarkable sensitivity to CN- with a limit of detection of 0.35 µM. The interaction of compound 3b with CN- and F- was also analyzed by 1H NMR titrations showing that increasing concentration of anion induces a deprotonation of NH and OH groups.Thanks are due to 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/00686/2020)), and a PhD grant to R.P.C.L.S. (SFRH/BD/145639/2019). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network (PTNMR) and was financially partially supported by Infrastructure Project No. 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL, and FCT through PIDDAC)

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

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    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

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    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

    Choroidal Indices as Predictors of Visual Outcomes to anti-VEGF Treatment in DME patients, using Swept Source OCT

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    [Purpose : To evaluate the associations between anti-VEGF therapy and central choroidal thickness (CCT), choroidal vascular density (CVD) and choroidal vascular volume (CVV), in patients with Diabetic Macular Edema (DME) using Swept Source OCT (SS-OCT), and to correlate these findings with treatment visual outcomes.]info:eu-repo/semantics/publishedVersio

    Breastfeeding : prevalence and determinant factors

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    Breastfeeding:Prevalence and Determinant Factors Breastfeeding is the best way of feeding the baby for the first six months of life. However, in Portugal the abandonment rate of breastfeeding is very high during the baby first’s months of life. The aim of this study was to assess prevalence of breastfeeding and to identify related factors during the six months after delivery, as sociodemographic variables and life styles. We conducted a cohort study at the Maternity of the Hospital Santa Maria. A standard questionnaire was applied to 475 women after delivery, at three and six months postpartum. We studied socio demographics aspects, life styles and the way of feeding during the six months after delivery. Multivariate analysis was performed. The women studied (mean age of 29,8 +/- 5,4 years), 52,2% were primiparous, 86,1% were Caucasian, 40% had a high school degree and 33% had a University degree. Four hundred and sixty (96,8%) received prenatal care. The mean gestational age was 38,8 +/- 2 weeks and the birth weight was 3198,3 +/- 545,3 g. At the discharge 91% were breastfeeding (77% exclusively), 54,7% at third month and 34,1% at sixth month. The main causes pointed for abandoning breastfeeding were insufficient milk production, bad sucking and return to work. The milk formula introduction was in 68,6% cases by medical recommendation. The decision in maintenance breastfeeding at third and sixth months was correlated with a previous positive breastfeed experience, high educational level, healthy lifestyles, as non-smoking, regular physical activity, and information about advantage of breastfeed for mother health. Information about breastfeeding was received by media, friends, family and only 9% by health professionals. Fifty (13%) women had no information about breastfeeding. Although breastfeeding rate at discharge was high, there was an important rate of abandonment at third and sixth month. Healthy lifestyles, high educational level, a previous positive breastfeed experience had a positive influence in breastfeeding. Understanding attitudes towards pregnancy and breastfeeding can lead to new strategies for its promotion and maintenance.O leite materno constitui o melhor alimento para o bebé nos primeiros quatro a seis meses de vida. No entanto, em Portugal, a taxa de abandono do aleitamento materno é muito importante logo nos primeiros meses de vida do bebé. Objectivos: Avaliar a prevalência do aleitamento materno e identificar factores determinantes da amamentação nos primeiros seis meses pós-parto, nomeadamente características socioeconómicas e estilos de vida. Material e Métodos: Estudo longitudinal prospectivo abrangendo 475 puérperas na Maternidade do Hospital Santa Maria – Lisboa, baseado em questionários directos aplicados no pós-parto, aos 3 e 6 meses. As variáveis incluídas permitiram caracterizar factores socio-económicos, estilos de vida e o tipo de aleitamento nos primeiros seis meses após o parto. Foi realizada análise multivariada. Resultados: Das puérperas estudadas (idade média 29,8 ± 5,4 anos) 52,2 % eram primíparas, 86,1% caucasianas, com escolaridade correspondente ao ensino secundário em 40% e universitário em 33%. A vigilância regular da gravidez ocorreu em 96,8%, a idade gestacional média dos recém nascidos foi de 38,8 ± 2,1 semanas e o peso ao nascer de 3198,3 ± 545,3 gramas. À saída da maternidade, 91% das puérperas amamentavam o seu filho (77,7% em exclusividade) tendo esta percentagem diminuído para 54,7% aos três meses e 34,1% aos seis meses. As causas referidas para o abandono foram a hipo ou agalactia, a má pega e o regresso ao trabalho. De notar que em 68,6% a iniciativa de prescrever a fórmula coube ao médico assistente. A decisão da mulher em manter o aleitamento aos três e aos seis meses foi influenciada pela experiência positiva de amamentar, o nível educacional mais elevado, o não-tabagismo, a prática de exercício físico e a informação sobre as vantagens da amamentação para a saúde materna. A fonte de informação sobre o aleitamento materno coube, por ordem decrescente, aos meios de comunicação, amigos e família e aos profissionais de saúde (9%), sendo que 13% não tinham tido qualquer informação. Conclusão: A taxa de aleitamento materno à saída da maternidade foi elevada mas verificou-se uma acentuada taxa de abandono aos três e aos seis meses. Os estilos de vida saudáveis, o nível educacional elevado e a experiência de amamentar positiva tiveram influência positiva na amamentação. A compreensão das atitudes perante a gravidez e o aleitamento materno pode levar a novas estratégias de intervenção para a sua promoção e manutenção.Trabalho realizado com o apoio dos Laboratórios Abbot Portugal

    The validity and reliability of the Portuguese versions of three tools used to diagnose delirium in critically ill patients

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    OBJECTIVES: The objectives of this study are to compare the sensitivity and specificity of three diagnostic tools for delirium (the Intensive Care Delirium Screening Checklist, the Confusion Assessment Method for Intensive Care Units and the Confusion Assessment Method for Intensive Care Units Flowsheet) in a mixed population of critically ill patients, and to validate the Brazilian Portuguese Confusion Assessment Method for Intensive Care Units. METHODS: The study was conducted in four intensive care units in Brazil. Patients were screened for delirium by a psychiatrist or neurologist using the Diagnostic and Statistical Manual of Mental Disorders. Patients were subsequently screened by an intensivist using Portuguese translations of the three tools. RESULTS: One hundred and nineteen patients were evaluated and 38.6% were diagnosed with delirium by the reference rater. The Confusion Assessment Method for Intensive Care Units had a sensitivity of 72.5% and a specificity of 96.2%; the Confusion Assessment Method for Intensive Care Units Flowsheet had a sensitivity of 72.5% and a specificity of 96.2%; the Intensive Care Delirium Screening Checklist had a sensitivity of 96.0% and a specificity of 72.4%. There was strong agreement between the Confusion Assessment Method for Intensive Care Units and the Confusion Assessment Method for Intensive Care Units Flowsheet (kappa coefficient = 0.96) CONCLUSION: All three instruments are effective diagnostic tools in critically ill intensive care unit patients. In addition, the Brazilian Portuguese version of the Confusion Assessment Method for Intensive Care Units is a valid and reliable instrument for the assessment of delirium among critically ill patients

    Secretome of the preimplantation human embryo by bottom-up label-free proteomics

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    Abstract A bottom-up label-free mass spectrometric proteomic strategy was used to analyse the protein profiles of the human embryonic secretome. Culture media samples used for embryonic culture of patients undergoing intracytoplasmic sperm injection cycles were selected as a test case for this exploratory proof-of-principle study. The media were stored after embryo transfer and then pooled into positive (n = 8) and negative (n =8) implantation groups. The absolute quantitative bottom-up technique employed a multidimensional protein identification technology based on separation by nano-ultra-high pressure chromatography and identification via tandem nanoelectrospray ionization mass spectrometry with dataindependent scanning in a hydrid QqTOF mass spectrometer. By applying quantitative bottom-up proteomics, unique proteins were found exclusively in both the positive-and negative-implantation groups, which suggest that competent embryos express and secrete unique biomarker proteins into the surrounding culture medium. The selective monitoring of these possible secretome biomarkers could make viable procedures using singleembryo transfer

    Correlation between MMPs and their inhibitors in breast cancer tumor tissue specimens and in cell lines with different metastatic potential

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    Background: The metastatic disease rather than the primary tumor itself is responsible for death in most solid tumors, including breast cancer. The role of matrix metalloproteinases ( MMPs), tissue inhibitors of MMPs (TIMPs) and Reversion-inducing cysteine-rich protein with Kazal motifs ( RECK) in the metastatic process has previously been established. However, in all published studies only a limited number of MMPs/MMP inhibitors was analyzed in a limited number of cell lines. Here, we propose a more comprehensive approach by analyzing the expression levels of several MMPs (MMP-2, MMP-9 and MMP-14) and MMP inhibitors (TIMP-1, TIMP-2 and RECK) in different models ( five human breast cancer cell lines, 72 primary breast tumors and 30 adjacent normal tissues). Methods: We analyzed the expression levels of MMP-2, MMP-9 and MMP-14 and their inhibitors (TIMP-1, TIMP-2 and RECK) by quantitative RT-PCR (qRT-PCR) in five human breast cancer cell lines presenting increased invasiveness and metastatic potential, 72 primary breast tumors and 30 adjacent normal tissues. Moreover, the role of cell-extracellular matrix elements interactions in the regulation of expression and activity of MMPs and their inhibitors was analyzed by culturing these cell lines on plastic or on artificial ECM (Matrigel). Results: The results demonstrated that MMPs mRNA expression levels displayed a positive and statistically significant correlation with the transcriptional expression levels of their inhibitors both in the cell line models and in the tumor tissue samples. Furthermore, the expression of all MMP inhibitors was modulated by cell-Matrigel contact only in highly invasive and metastatic cell lines. The enzyme/inhibitor balance at the transcriptional level significantly favors the enzyme which is more evident in tumor than in adjacent non-tumor tissue samples. Conclusion: Our results suggest that the expression of MMPs and their inhibitors, at least at the transcriptional level, might be regulated by common factors and signaling pathways. Therefore, the multi-factorial analysis of these molecules could provide new and independent prognostic information contributing to the determination of more adequate therapy strategies for each patient.`Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Pesquisa (CNPq)Financiadora de Estudos e Projetos (FINEP)Pro-Reitoria da Universidade de Sao Paulo (PRP-USP

    Diabetic Choroidopathy: Choroidal Vascular Density and Volume in Diabetic Retinopathy With Swept-Source Optical Coherence Tomography

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    Purpose To compare choroidal vascular density (CVD) and volume (CVV) in diabetic eyes and controls, using en face swept-source optical coherence tomography (SS-OCT). Design Prospective cross-sectional study. Methods Setting: Multicenter. Patient Population: Total of 143 diabetic eyes—27 with no diabetic retinopathy (DR), 47 with nonproliferative DR (NPDR), 51 with NPDR and diabetic macular edema (DME), and 18 with proliferative DR (PDR)—and 64 age-matched nondiabetic control eyes. Observation Procedures: Complete ophthalmologic examination and SS-OCT imaging. En face SS-OCT images of the choroidal vasculature were binarized. Main Outcome Measures: CVD, calculated as the percent area occupied by choroidal vessels in the central macular region (6-mm-diameter circle centered on the fovea), and throughout the posterior pole (12 × 9 mm). The central macular CVV was calculated by multiplying the average CVD by macular area and choroidal thickness (obtained with SS-OCT automated software). Multilevel mixed linear models were performed for analyses. Results Compared to controls (0.31 ± 0.07), central macular CVD was significantly decreased by 9% in eyes with NPDR + DME (0.28 ± 0.06; ß = −0.03, P = .02) and by 15% in PDR (0.26 ± 0.05; ß = −0.04, P = .01). The central macular CVV was significantly decreased by 19% in eyes with PDR (0.020 ± 0.005 mm3, ß = −0.01, P = .01) compared to controls (0.025 ± 0.01 mm3). Conclusions Choroidal vascular density and volume are significantly reduced in more advanced stages of diabetic retinopathy. New imaging modalities should allow further exploration of the contributions of choroidal vessel disease to diabetic eye disease pathogenesis, prognosis, and treatment response.info:eu-repo/semantics/publishedVersio
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