501 research outputs found
Colonização oral fúngica em indivíduos diabéticos
Poster apresentado nas XXI Jornadas de Ciências Farmacêuticas do ISCSEM - Instituto Superior de Ciências da Saúde Egas Moniz. 5-6 de Maio de 2015, Caparica
Oral Candida colonization in diabetic individuals non-carriers of dental prosthesis
Poster presented at the First International Congress of CiiEM - From Basic Sciences to Clinical Research. 27-28 November 2015, Egas Moniz, Caparica, Portuga
Coaching in pharmaceutical sciences
Poster presented at the European Association of Faculties of Pharmacy Annual Conference. 15-17 May 2019, Krakow, PolandN/
Photophysical characterization and ion sensing properties of new colorimetric chemosensors based on hydrazones bearing quinoline
Molecular receptors are chemical species designed to achieve a high degree of complementarity with a selected guest. When synthetic receptors are coupled with certain signaling units, that could change one or more physical properties upon receptor-guest interaction (e.g. color, fluorescence, redox potential), a molecular sensor is obtained. In this field is especially appealing the use of optical outputs such as changes in color and/or fluorescence that allow the use of low-cost and widely available instrumentation. Moreover, in the case of chromogenic chemosensors, a straightforward semi-quantitative and in situ “naked-eye” detection is possible and chromo-fluorogenic chemosensors displaying a displacement of the absorption or emission bands are interesting for the development of ratiometric procedures.
Hydrazone and quinoline derivatives have been reported to be suitable systems for the optical (colorimetric and fluorimetric) sensing of certain anions and for the recognition of metal cations. Other applications in materials science include molecular switches and OLEDs.
Taking into account the above mentioned facts and our interest in the development of optical probes, we report herein the synthesis, photophysical characterization and interaction studies toward anions and cations, in ACN, of probes 2a-b containing hidrazono-quinoline moieties as both binding and signaling subunits. Moreover, selective detection of cyanide was achieved in aqueous mixtures for chemosensor 2a.FCTFEDERQRE
Heterocyclic dicyanovinyl derivatives: synthesis and evaluation of the chemosensory ability in aqueous solution
Two novel dicyanovinyl derivatives 3a-b were synthesized in moderate to good yields through a Knoevenagel reaction of the corresponding aldehyde precursors and malononitrile. The photophysical properties of the new push-pull systems were studied by UV-vis and fluorescence spectroscopy in acetonitrile. The evaluation of the compounds as colorimetric chemosensors was carried out by performing spectrophotometric titrations in acetonitrile and acetonitrile/water in the presence of relevant organic and inorganic anions, and of alkaline, alkaline-earth and transition metal cations. The benzoindole derivative exhibited great selectivity for the cyanide anion over other anions in acetonitrile/water (8:2) solution showing a distinct color change from colorless to yellow.FCTFEDERQRE
Synthesis, characterization and evaluation of the chemosensory ability of benzothiazolium salts bearing a triphenylamino donor group and an aryl spacer
Organic salts are the focus of much recent attention, in part due to their stability and the ease of tailoring for specific physical properties. In particular, styryl-pyridinium and benzothiazolium salts have been widely applied in diverse areas such as NLO-phores, frequency-upconversion, optical power limiting, fluorescent probes, laser scanning fluorescence microscopy, molecular switches, etc.1 The recognition and detection of ionic species has aroused great interest due to their important roles in many biological and environmental processes. Several sensor systems have been developed but most present some limitations in terms of sensitivity, selectivity, and simplicity. Colorimetric chemosensors are molecules that allow naked-eye detection of ionic species without resource to any instrumentation, offering qualitative and quantitative information. These chemical sensors are considered as one of the most effective analytical methods for environmental monitoring, particularly in the detection of metal ions whose presence in the environment has serious consequences. Additionally, chemosensors soluble in aqueous media are very interesting, because of the importance in sensing species in biological processes, disease states and environmental pollution.2
In this communication, we report the synthesis of two benzothiazolium salts 3a-b, substituted at position 2 with a triphenylamino donor group and an aryl spacer with different electronic character, in order to evaluate their photophysical properties and chemosensory ability. Organic salts 3 were synthesized through Knoevenagel reaction between the precursor aldehydes 2 and 1-methylbenzothiazolium salt 1 in moderate to good yields. The new derivatives were characterized by the usual techniques and a detailed photophysical study was undertaken. The evaluation of the compounds as colorimetric chemosensors was carried out by performing titrations in acetonitrile and acetonitrile/water in the presence of relevant organic and inorganic anions, and of alkaline, alkaline-earth and transition metal cations.Thank are due to Fundação para a Ciência e Tecnologia (Portugal) and FEDER-COMPETE for financial support through Centro de Química (PEst-C/QUI/UI0686/2013 (FCOMP-01-0124-FEDER-037302)), and a PhD grant to R.C.M. Ferreira (SFRH/BD/86408/2012). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased with funds from FCT and FEDER
A Two-Step Segmentation Method for Breast Ultrasound Masses Based on Multi-resolution Analysis
Breast ultrasound images have several attractive properties that make them an interesting tool in breast cancer detection. However, their intrinsic high noise rate and low contrast turn mass detection and segmentation into a challenging task. In this article, a fully automated two-stage breast mass segmentation approach is proposed. In the initial stage, ultrasound images are segmented using support vector machine or discriminant analysis pixel classification with a multiresolution pixel descriptor. The features are extracted using non-linear diffusion, bandpass filtering and scale-variant mean curvature measures. A set of heuristic rules complement the initial segmentation stage, selecting the region of interest in a fully automated manner. In the second segmentation stage, refined segmentation of the area retrieved in the first stage is attempted, using two different techniques. The AdaBoost algorithm uses a descriptor based on scale-variant curvature measures and non-linear diffusion of the original image at lower scales, to improve the spatial accuracy of the ROI. Active contours use the segmentation results from the first stage as initial contours. Results for both proposed segmentation paths were promising, with normalized Dice similarity coefficients of 0.824 for AdaBoost and 0.813 for active contours. Recall rates were 79.6% for AdaBoost and 77.8% for active contours, whereas the precision rate was 89.3% for both methods.info:eu-repo/semantics/publishedVersio
Synthesis and evaluation of heterocyclic pyrrolidene imines as optical chemosensors
Imine derivatives are an important class of compounds due their biological and optical properties making them suitable for several applications such as chemosensor, photochromic, and others.[1,2] In recent years the search for new colorimetric chemosensors for anions has been of great interest because of the role that ions play in chemical and biological processes.[3] In this context and as part of an on-going research to develop efficient heterocyclic systems for photochromic and chemosensor applications [4] we report in this communication the synthesis, the photophysical characterization and the chemosensor ability of pyrrolidene heterocyclic imines functionalized with aryl or naphthyl moieties.Thanks are due to Fundacao para a Ciencia e Tecnologia (FCT-Portugal) and FEDER-COMPETE for financial support through Centro de Quimica [PEst-C/QUI/UI0686/2013 (FCOMP-01-0124-FEDER-037302)], PhD grants to M.C.R. Castro (SFRH/BD/78037/2011) and R.C.M. Ferreira (SFRH/BD/86408/2012). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased with funds from FCT and FEDER. We are also grateful to the Instituto da Educação of Universidade do Minho for providing the laboratory infrastructure necessary for the development of this work
Congenital Lobar Emphysema: A Multilobar Presentation
O enfisema lobar congénito é umamalformação rara do tracto respiratório inferior detectada habitualmente nos primeiros meses de vida. Apresenta-se o caso de um lactente, do sexo masculino, de dois meses de idade, internado por suspeita de pneumonia, no qual
a segunda radiografia de tórax revelou hipertransparência arredondada no lobo inferior esquerdo, sugestiva de enfisema lobar congénito.
A tomografia computorizada torácica mostrou uma imagem quística,multilobar, e a broncoscopia excluiu obstrução brônquica.
Foi programada cirurgia para os seis meses de idade, mas aos três meses foi submetido a intervenção cirúrgica urgente por pneumotórax
hipertensivo. O exame anatomo-patológico da peça operatória permitiu o diagnóstico de enfisema lobar congénito. Destaca-se
a apresentação multilobar e a complicação por pneumotórax
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