19 documents found, page 1 of 2
New Red-Shifted 4-Styrylcoumarin Derivatives as Potential Fluorescent Labels fo...
Eustáquio, R.; Ramalho, J.P.P.; Caldeira, A.T.; Pereira, A.Important scientific areas, such as cellular biology, medicine, pharmacy, and environmental sciences, are dependent on very sensitive analytical techniques to track and detect biomolecules. In this work, we develop a simple, low-cost and effective synthetic strategy to produce new red-shifted 4-styrylcoumarin derivatives as promising inexpensive fluorescent labels for biomolecules. The extension of the delocali...
Development of new 2-piperidinium-4- styrylcoumarin derivatives with large Stok...
Eustáquio, R.; Ramalho, J.P.P.; Caldeira, A.T.; Pereira, A.A series of novel 2-piperidinium-4-styrylcoumarin derivatives, with large Stokes shifts and high fluorescence quantum yields, were synthesized using an efficient and low-cost synthetic strategy as potential fluorescent labels for biomolecules. Density functional theory and time-dependent density functional theory calculations were performed in order to rationalize the observed photophysical properties.; The stu...
6.4. New Red-Shifted 4-Styryl Coumarins as Potential Fluorescent Labels for Bio...
Eustáquio, R.; Ramalho, J.P.P.; Caldeira, A.T.; Pereira, A.Cellular biology, medicine, pharmacy, environmental sciences and other important scientific areas require highly sensitive analytical techniques to track and detect nucleic acids, oligonucleotides, antibodies, amino acids, proteins, lipids, carbohydrates, and other biomolecules. Of all sensitive analytical techniques, fluorescent labeling presents numerous advantages as it allows the use of small sample quantit...
The inhibition of biodegradation on building limestone by plasma etching
Schiavon, Nicola; Caldeira, A.T.; Grassini, S; Ding, Y; Salvador, CátiaPlasma etching is an innovative technique that has been recently applied in the cleaning of soiled archaeological objects. This research investigated the use of low-pressure plasma etching in cleaning microbial contaminations on an oolitic limestone from an UNESCO World Heritage listed monument: the Batalha Monastery in Central Portugal. The cleaning effect was assessed by FTIR, SEM, optical microscope, and cel...
Biodegradation and Microbial Contamination of Limestone Surfaces: An Experiment...
Schiavon, Nicola; Ding, Y.; Salvador, Cátia; Caldeira, A.T.; Angelini, E.An experimental study was conducted to assess the nature and extent of the biodeterioration of the limestone in the Batalha Monastery in Portugal. Stone fragments covered with microbial biofilms and lichenous crusts were investigated using Optical Microscopy (OM), Low Vacuum Scanning Electron Microscopy with Energy Dispersive Spectroscopy (LV-SEM + EDS), and X-ray micro-Diffractometry ( -XRD). Microbial samples...
Searching for subterranean-adapted microorganisms as part of the ESA CAVES and ...
Miller, A.Z.; Caldeira, A.T.; De Waele, J.; D’Angeli, I.M.; Payler, S.J.; Gabrovšek, F.; Bessone, L.; Sauro, F.Caves on Earth are catching the attention of the space agencies for testing new approaches to planetary science investigations. These subterranean environments could protect astronauts from the high levels of cosmic radiation and extremes of temperature during human missions to the Moon and Mars. As these celestial bodies are likely to contain caves and a record of secondary mineralization, studying secondary m...
Analytical and Microbiological Study of two 19th Century Ambrotypes
Nunes, M.; Miguel, C.; Caldeira, A.T.; Ferreira, T.The study here presented aimed to characterize two ambrotypes from the 19th century and some of their degradation patterns using an in-situ analytical approach, minimally invasive, composed by technical photography and optical microscopy under different illumination, scanning electron microscopy with energy dispersive spectroscopy coupled (SEM-EDS) and micro-Fourier transform infrared spectroscopy (μ-FT-IR). Mi...
Desenvolvimento de novos materiais com propriedades biocidas para aplicação com...
Plácido, M.; Galacho, Cristina; Girginova, P.I.; Caldeira, A.T.; Candeias, A.Estudos recentes em conservação e restauro têm visado a definição das etapas e das técnicas de intervenção no património cultural. As tendências atuais de investigação confirmam que a perda de coesão das argamassas históricas, por efeito da dissolução do ligante e/ou de destruição da estrutura porosa, é uma evidência frequente em superfícies arquitetónicas antigas. A etapa de consolidação surge como uma das pri...
A non-destructive approach to the study of 20th century gelatine negatives
Nunes, M.; Miguel, C.; Caldeira, A.T.; Ferreira, T.Two 20th century gelatine glass plate negatives, belonging to Eduardo Nogueira’s collection owned by the Photographic Archive of Évora, were studied by an in-situ multi-analytical approach that included technical photography, optical microscopy, scanning electron microscopy coupled with X-ray microanalysis and micro-FT-IR spectroscopy. The plates present several damages, probably due to neglected handling, and ...
Exploring the potential of novel biomixtures and Lentinula edodes fungus for th...
Pinto, A. P.; Rodrigues, S. C.; Caldeira, A.T.; Teixeira, D.M.An approach to reduce the contamination of water sourceswith pesticides is the use of biopurificaction systems. The active core of these systems is the biomixture. The composition of biomixtures depends on the availability of local agro-industrial wastes and design should be adapted to every region. In Portugal, cork processing is generally regarded as environmentally friendly and would be interesting to find a...