Search

Your search keyword '"Martinho, José M. G."' showing total 20 results
Start Over Author "Martinho, José M. G." Publication Year Range Last 10 years
20 results on '"Martinho, José M. G."'

5. Safety assessment of new nanodiamonds@corrole hybrids addressed by the response of RAW-264.7 macrophages

Author

Santos, Carla I. M., primary, Cicuéndez, Mónica, additional, Gonçalves, Gil, additional, Rodríguez-Pérez, Laura, additional, Portolés, M. Teresa, additional, Faustino, M. Amparo F., additional, Herranz, M. Ángeles, additional, Neves, M. Graça P. M. S., additional, Martinho, José M. G., additional, Maçôas, Ermelinda M. S., additional, and Martín, Nazario, additional

Published
2023
Full Text
View/download PDF

7. Enhanced Photodynamic Therapy Effects of Graphene Quantum Dots Conjugated with Aminoporphyrins

Author

Santos, Carla I. M., primary, Rodríguez-Pérez, Laura, additional, Gonçalves, Gil, additional, Dias, Cristina J., additional, Monteiro, Fátima, additional, Faustino, Maria do Amparo F., additional, Vieira, Sandra I., additional, Helguero, Luisa A., additional, Herranz, María Ángeles, additional, Martín, Nazario, additional, Neves, M. Graça P. M. S., additional, Martinho, José M. G., additional, and Maçôas, Ermelinda M. S., additional

Published
2021
Full Text
View/download PDF

9. Fluorescence Anisotropy of Hydrophobic Probes in Poly(N-decylacrylamide)-block-poly(N,N-diethylacrylamide) Block Copolymer Aqueous Solutions: Evidence of Premicellar Aggregates

Author

Beija, Mariana, Fedorov, Aleksander, Charreyre, Marie-Thérèse, and Martinho, José M. G.

Abstract

Fluorescent probes, coumarin 153 (C153) and octadecylrhodamine B (ORB), were used to study the self-assembly in water of poly(N-decylacrylamide)-block-poly(N,N-diethylacrylamide), (PDcA11-block-PDEA295; Mn= 40 300 g mol−1; Mw/Mn= 1.01). From the variation of both the fluorescence intensity and the solvatochromic shifts of C153 with polymer concentration, the critical micelle concentration (CMC) was determined as 1.8 ± 0.1 μM. On the other hand, steady-state anisotropy measurements showed the presence of premicellar aggregates below the CMC. Time-resolved fluorescence anisotropy evidenced that ORB is located in the premicellar aggregates and the micelle core, while C153 is partitioned between the aggregates and the water phase. The micelle core contains both semicrystalline and amorphous regions. In the semicrystalline regions the probes cannot rotate, while in the amorphous regions the rotational correlation times correlate well with the hydrodynamic volume of the probes. The amorphous region of the micelle core is relatively fluid, reflecting the large free-volume accessible to the probes.

Published
2024
Full Text
View/download PDF

17. Synthesis of a Biologically Active Oxazol-5-(4H)-one via an Erlenmeyer-Plöchl Reaction.

Author

Rodrigue, Catarina A. B., Martinho, José M. G., and Afonso, Carlos A. M.

Subjects
*CHEMICAL synthesis, *CLICK chemistry, *OXAZOLES, *AZOLES, *BENZYLIDENE compounds
Abstract

The synthesis of (Z)-4-(4-nitrobenzylidene)-2-phenyloxazol-5(4H)-one, which is a potent immunomodulator and tyrosinase inhibitor, is described as an experiment for an upper-division undergraduate organic chemistry laboratory course. This compound is produced via an Erlenmeyer-Plöchl reaction in the absence of any additional solvents and is isolated without need of preparative chromatography, yielding up to 97% of product. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
View/download PDF

19. Combining metal nanoclusters and carbon nanomaterials: Opportunities and challenges in advanced nanohybrids.

Author

Lopes RCFG, Rocha BGM, Maçôas EMS, Marques EF, and Martinho JMG

Subjects
Catalysis, Metals chemistry, Nanotechnology, Carbon chemistry, Nanostructures chemistry
Abstract

The development of functional materials with uniquely advanced properties lies at the core of nanoscience and nanotechnology. From the myriad possible combinations of organic and/or inorganic blocks, hybrids combining metal nanoclusters and carbon nanomaterials have emerged as highly attractive colloidal materials for imaging, sensing (optical and electrochemical) and catalysis, among other applications. While the metal nanoclusters provide extraordinary luminescent and electronic properties, the carbon nanomaterials (of zero, one or two dimensions) convey versatility, as well as unique interfacial, electronic, thermal, optical, and mechanical properties, which altogether can be put to use for the desired application. Herein, we present an overview of the field, for experts and non-experts, encompassing the basic properties of the building blocks, a systematic view of the chemical preparation routes and physicochemical properties of the hybrids, and a critical analysis of their ongoing and emerging applications. Challenges and opportunities, including directions towards green chemistry approaches, are also discussed., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Published
2022
Full Text
View/download PDF

20. Nonlinear emission of quinolizinium-based dyes with application in fluorescence lifetime imaging.

Author

Marcelo G, Pinto S, Cañeque T, Mariz IF, Cuadro AM, Vaquero JJ, Martinho JM, and Maçôas EM

Subjects
Fluorescent Dyes chemical synthesis, HEK293 Cells, Humans, Microscopy, Fluorescence, Molecular Structure, Quantum Theory, Quinolizines chemical synthesis, Fluorescent Dyes chemistry, Quinolizines chemistry
Abstract

Charged molecules based on the quinolizinum cation have potential applications as labels in fluorescence imaging in biological media under nonlinear excitation. A systematic study of the linear and nonlinear photophysics of derivatives of the quinolizinum cation substituted by either dimethylaniline or methoxyphenyl electron donors is performed. The effects of donor strength, conjugation length, and symmetry in the two-photon emission efficiency are analyzed in detail. The best performing nonlinear fluorophore, with two-photon absorption cross sections of 1140 GM and an emission quantum yield of 0.22, is characterized by a symmetric D-π-A(+)-π-D architecture based on the methoxyphenyl substituent. Application of this molecule as a fluorescent marker in optical microscopy of living cells revealed that, under favorable conditions, the fluorophore can be localized in the cytoplasmatic compartment of the cell, staining vesicular shape organelles. At higher dye concentrations and longer staining times, the fluorophore can also penetrate into the nucleus. The nonlinearly excited fluorescence lifetime imaging shows that the fluorophore lifetime is sensitive to its location in the different cell compartments. Using fluorescence lifetime microscopy, a multicolor map of the cell is drafted with a single dye.

Published
2015
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results