Export 1645 results:
Sort by: Author Title Type [ Year  (Desc)]
2017
Lavande, N, Acuna A, Basilio N, Francisco V, Malkhede DD, Garcia-Rio L.  2017.  A journey from calix 4 arene to calix 6 and calix 8 arene reveals more than a matter of size. Receptor concentration affects the stability and stoichiometric nature of the complexes, 2017. Physical Chemistry Chemical Physics. 19(21):13640-13649. AbstractWebsite
n/a
Martins, ICB, Oliveira MC, Diogo HP, Branco LC, Duarte MT.  2017.  MechanoAPI-ILs: Pharmaceutical Ionic Liquids Obtained through Mechanochemical Synthesis, 2017. Chemsuschem. 10(7):1360-1363. AbstractWebsite
n/a
Vinhas, R, Mendes R, Fernandes AR, Baptista PV.  2017.  Nanoparticles—Emerging Potential for Managing Leukemia and Lymphoma, 2017. 5:79. AbstractWebsite

Nanotechnology has become a powerful approach to improve the way we diagnose and treat cancer. In particular, nanoparticles possess unique features for enhanced sensitivity and selectivity for earlier detection of circulating cancer biomarkers. In vivo, nanoparticles enhance the therapeutic efficacy of anticancer agents when compared to conventional chemotherapy, improving vectorization and delivery, and helping to overcome drug resistance. Nanomedicine has been mostly focused on solid cancers due to take advantage from the enhanced permeability and retention (EPR) effect experienced by tissues in the close vicinity of tumors, which enhance nanomedicine’s accumulation and, consequently, improve efficacy. Nanomedicines for leukemia and lymphoma, where EPR effect is not a factor, are addressed differently from solid tumors. Nevertheless, nanoparticles have provided innovative approaches to simple and non-invasive methodologies for diagnosis and treatment in liquid tumors. In this review, we consider the state of the art on different types of nanoconstructs for the management of liquid tumors, from pre-clinical studies to clinical trials. We also discuss the advantages of nanoplatforms for theranostics and the central role played by nanoparticles in this combined strategy.

Basilio, N, Mendoza J, Gago S, Parola AJ.  2017.  pH-Driven self-sorting in a four component host-guest system, 2017. Chemical Communications. 53(48):6472-6475. AbstractWebsite
n/a
Romero, MA, Basilio N, Moro AJ, Domingues M, Gonzalez-Delgado JA, Arteaga JF, Pischel U.  2017.  Photocaged Competitor Guests: A General Approach Toward Light-Activated Cargo Release From Cucurbiturils, 2017. Chemistry-a European Journal. 23(53):13105-13111. AbstractWebsite
n/a
Mendes, R, Pedrosa P, Lima JC, Fernandes AR, Baptista PV.  2017.  Photothermal enhancement of chemotherapy in breast cancer by visible irradiation of Gold Nanoparticles, 2017. Scientific Reports. 7 AbstractWebsite
n/a
Mendes, R, Pedrosa P, Lima JC, Fernandes AR, Baptista PV.  2017.  Photothermal enhancement of chemotherapy in breast cancer by visible irradiation of Gold Nanoparticles, 2017. 7(1):10872. AbstractWebsite

Photothermal Therapy (PTT) impact in cancer therapy has been increasing due to the enhanced photothermal capabilities of a new generation of nanoscale photothermal agents. Among these nanoscale agents, gold nanoshells and nanorods have demonstrated optimal properties for translation of near infra-red radiation into heat at the site of interest. However, smaller spherical gold nanoparticles (AuNPs) are easier to produce, less toxic and show improved photoconversion capability that may profit from the irradiation in the visible via standard surgical green lasers. Here we show the efficient light-to-heat conversion of spherical 14 nm AuNPs irradiated in the visible region (at the surface plasmons resonance peak) and its application to selectively obliterate cancer cells. Using breast cancer as model, we show a synergistic interaction between heat (photoconversion at 530 nm) and cytotoxic action by doxorubicin with clear advantages to those of the individual therapy approaches.

Pedrosa, P, Heuer-Jungemann A, Kanaras AG, Fernandes AR, Baptista PV.  2017.  Potentiating angiogenesis arrest in vivo via laser irradiation of peptide functionalised gold nanoparticles, 2017. 15(1):85. AbstractWebsite

Anti-angiogenic therapy has great potential for cancer therapy with several FDA approved formulations but there are considerable side effects upon the normal blood vessels that decrease the potential application of such therapeutics. Chicken chorioallantoic membrane (CAM) has been used as a model to study angiogenesis in vivo. Using a CAM model, it had been previously shown that spherical gold nanoparticles functionalised with an anti-angiogenic peptide can humper neo-angiogenesis.

Santos, MM, Bastos P, Catela I, Zalewska K, Branco LC.  2017.  Recent Advances of Metallocenes for Medicinal Chemistry, 2017. Mini-Reviews in Medicinal Chemistry. 17(9):771-784. AbstractWebsite
n/a
Roma-Rodrigues, C, Pereira F, Alves de Matos AP, Fernandes M, Baptista PV, Fernandes AR.  2017.  Smuggling gold nanoparticles across cell types – A new role for exosomes in gene silencing, 2017. 13(4):1389-1398. AbstractWebsite

Once released to the extracellular space, exosomes enable the transfer of proteins, lipids and RNA between different cells, being able to modulate the recipient cells' phenotypes. Members of the Rab small GTP-binding protein family, such as RAB27A, are responsible for the coordination of several steps in vesicle trafficking, including budding, mobility, docking and fusion. The use of gold nanoparticles (AuNPs) for gene silencing is considered a cutting-edge technology. Here, AuNPs were functionalized with thiolated oligonucleotides anti-RAB27A (AuNP@PEG@anti-RAB27A) for selective silencing of the gene with a consequent decrease of exosomes´ release by MCF-7 and MDA-MB-453 cells. Furthermore, communication between tumor and normal cells was observed both in terms of alterations in c-Myc gene expression and transportation of the AuNPs, mediating gene silencing in secondary cells.

Carrera, GVSM, Raymundo A, Fernandes FMB, Jordao N, Sousa I, da Ponte MN, Branco LC.  2017.  Tetramethylguanidine-based gels and colloids of cellulose, 2017. Carbohydrate Polymers. 169:58-64. AbstractWebsite
n/a
Brás, T, Seixas J.  2017.  Assessing the impact of climate extremes and energy use in crop production – EU28 agri-food suppliers, 18-20 Sep.. Fifth Annual International Conference on Sustainable Development. , New York, USA: Columbia University
Simoes, SG, Barbosa J, Fazendeiro L, Seixas J.  2017.  The Return of H2 – Challenges of Modelling H2 in TIMES, 11-12 December . 72nd Semi-annual ETSAP meeting. , Zurich, Switzerland: ETH Zurich
Beira, MJ, Daniel CI, Almeida PL, Corvo MC, Rosatella AA, Afonso CAM, Sebastiao PJ.  2017.  1H NMR Relaxometry and Diffusometry Study of Magnetic and Non-Magnetic Ionic Liquid-Based Solutions: Co-Solvent and Temperature Effects. The Journal of Physical Chemistry B. : ACS Publications AbstractWebsite

In this work, 1H NMR relaxometry and diffusometry as well as viscometry experiments were carried out as a means to study the molecular dynamics of magnetic and non-magnetic ionic liquid-based systems. In order to evaluate the effect of a co-solvent on the super-paramagnetic properties observed for Aliquat-iron-based magnetic ionic liquids, mixtures comprising different concentrations, 1% and 10% (v/v), of DMSO-d6 were prepared and analyzed. The results suggest that, when at low concentrations, DMSO-d6 promotes more structured ionic arrangements, thus enhancing these super-paramagnetic properties. Furthermore, the analysis of temperature and water concentration effects allowed to conclude that neither one of these variables sufficiently affected the super-paramagnetic properties of the studied magnetic ionic liquids.

João, C, Echeverria C, Velhinho A, Silva JC, Godinho MH, Borges JP.  2017.  Bio-inspired production of chitosan/chitin films from liquid crystalline suspensions. Carbohydrate polymers. 155:372-381. AbstractWebsite

Inspired by chitin based hierarchical structures observed in arthropods exoskeleton, this work reports the capturing of chitin nanowhiskers’ chiral nematic order into a chitosan matrix. For this purpose, highly crystalline chitin nanowhiskers (CTNW) with spindle-like morphology and average aspect ratio of 24.9 were produced by acid hydrolysis of chitin. CTNW were uniformly dispersed at different concentrations in aqueous suspensions. The suspensions liquid crystalline phase domain was determined by rheological measurements and polarized optical microscopy (POM). Chitosan (CS) was added to the CTNW isotropic, biphasic and anisotropic suspensions and the solvent was evaporated to allow films formation. The Films’ morphologies as well as the mechanical properties were explored. A correlation between experimental results and a theoretical model, for layered matrix’ structures with fibers acting as a reinforcement agent, was established. The results evidence the existence of two different layered structures, one formed by chitosan layers induced by the presence of chitin and another formed by chitin nanowhiskers layers. By playing on the ratio chitin/chitosan one layered structure or the other can be obtained allowing the tunning of materials’ mechanical properties.

Berride, F, Troche-Pesqueira E, Feio G, Cabrita EJ, Sierra T, Navarro-Vázquez A, Cid MM.  2017.  Chiral amplification of disodium cromoglycate chromonics induced by a codeine derivative. Soft Matter. 13(38):6810-6815. AbstractWebsite

Chromonic liquid crystals (CLC) are lyotropic phases formed by discotic mesogens in water. Simple chiral dopants such as amino acids have been reported to turn chromonic liquid crystals into their cholesteric counterparts. Here we report a chirality amplification effect in the nematic phase of a 9 wt% disodium cromoglycate (DSCG) lyotropic liquid crystal (LLC) upon doping with a water-soluble codeine derivative. The transition on cooling the isotropic to the nematic phase showed the presence of homochiral spindle-shaped droplets (tactoids). NMR DOSY experiments on a triple gradient probe revealed a small degree of diffusion anisotropy for the alkaloid embedded in the liquid crystal structure. These results in combination with XRD, CD and POM experiments agree with a supramolecular aggregation model based on simple columnar stacks.

João, C, Kullberg AT, Silva JC, Borges JP.  2017.  Chitosan Inverted Colloidal Crystal scaffolds: Influence of molecular weight on structural stability. Materials Letters. 193(15):50-53. AbstractWebsite

Chitosan with three different molecular weights (538 ± 48, 229 ± 45 and 13 ± 3 kDa) was used to develop biodegradable Inverted Colloidal Crystal (ICC) scaffolds with uniform pore size and interconnected pore network. Mass loss and compression modulus were analyzed after hydrolytic degradation in order to understand the influence of molecular weight on structural and mechanical degradation of chitosan ICC structures. Results show that medium molecular weight chitosan (229 ± 45 kDa) retains ICC structure and compression modulus for an extended period (4 weeks) and is therefore the preferred one for the production of ICC for soft tissue engineering.

Cruz, H, Jordão N, Amorim P, Dionísio M, Branco LC.  2017.  Deep Eutectic Solvents as Suitable Electrolytes for Electrochromic Devices. ACS Sustainable Chemistry and Engineering. 6(2):2240-2249.Website
Ribeiro, SO, Nogueira LS, Gago S, Almeida PL, Corvo MC, de Castro B, Granadeiro CM, Balula SS.  2017.  Desulfurization Process conciliating Heterogeneous Oxidation and liquid extraction: Organic Solvent or Centrifugation/Water? Applied Catalysis A: General. : Elsevier AbstractWebsite

The present work presents a strategic oxidative desulfurization system able to efficiently operate under sustainable conditions, i.e. using an eco-friendly oxidant and without the need of extractive organic solvents. The catalytic performance of Eu(PW11O39)2@aptesSBA-15 was evaluated for the oxidative desulfurization of a multicomponent model diesel using a solvent-free or biphasic systems. The results reveal its remarkable desulfurization performance achieving complete desulfurization after just 2 h of reaction. Moreover, the composite has shown a high recycling ability without loss of catalytic activity for ten consecutive ODS cycles. Interestingly, under solvent-free conditions it was possible to maintain the desulfurization efficiency of the biphasic system while being able to avoid the use of harmful organic solvents. In this case, a successful extraction of oxidized sulfur compounds was found conciliating centrifugation and water as extraction solvent. Therefore, this work reports an important step towards the development of novel eco-sustainable desulfurization systems with high industrial interest.

Peixoto, D, Figueiredo M, Gawande MB, Corvo MC, Vanhoenacker G, Afonso CAM, Ferreira LM, Branco PS.  2017.  DEVELOPMENTS IN THE REACTIVITY OF 2-METHYL IMIDAZOLIUM SALTS. The Journal of Organic Chemistry. 82(12):6232–6241.: American Chemical Society AbstractWebsite

Unexpected and unusual reactivity of 2-methylimidazolium salts toward aryl-N-sulfonylimines and aryl aldehydes is here reported. Upon reaction with aryl-N-sulfonylimines, the addition product, arylethyl-2-imidazolium-1-tosylamide (3), is formed with moderate to good yields, while upon reaction with aldehydes, the initial addition product (6) observed in NMR and HPLC–MS experimental analysis is postulated by us as an intermediate to the final conversion to carboxylic acids. Studies in the presence and absence of molecular oxygen allow us to conclude that the imidazolium salts is crucial for the oxidation. A detailed mechanistic study was carried out to provide insights regarding this unexpected reactivity.

Peters, J, Baumann M, Zimmermann B, Braun J, Weil M.  2017.  The environmental impact of Li-Ion batteries and the role of key parameters - A review. Renewable and Sustainable Energy Reviews. 2017(67):491-506. AbstractWebsite

The increasing presence of Li-Ion batteries (LIB) in mobile and stationary energy storage applications has triggered a growing interest in the environmental impacts associated with their production. Numerous studies on the potential environmental impacts of LIB production and LIB-based electric mobility are available, but these are very heterogeneous and the results are therefore difficult to compare. Furthermore, the source of inventory data, which is key to the outcome of any study, is often difficult to trace back. This paper provides a review of LCA studies on Li-Ion batteries, with a focus on the battery production process. All available original studies that explicitly assess LIB production are summarized, the sources of inventory data are traced back and the main assumptions are extracted in order to provide a quick overview of the technical key parameters used in each study. These key parameters are then compared with actual battery data from industry and research institutions. Based on the results from the reviewed studies, average values for the environmental impacts of LIB production are calculated and the relevance of different assumptions for the outcomes of the different studies is pointed out. On average, producing 1 Wh of storage capacity is associated with a cumulative energy demand of 328 Wh and causes greenhouse gas (GHG) emissions of 110 gCO2eq. Although the majority of existing studies focus on GHG emissions or energy demand, it can be shown that impacts in other categories such as toxicity might be even more important. Taking into account the importance of key parameters for the environmental performance of Li-Ion batteries, research efforts should not only focus on energy density but also on maximizing cycle life and charge-discharge efficiency.

Baumann, M, Marcelino C, Peters J, Weil M, Almeida P, Wanner E.  2017.  Environmental impacts of different battery technologies in renewable hybrid micro-grids. IEEE International Conference on Innovative Smart Grid Technologies. , Turin: IEEE
Maia, LB, Moura I, Moura JJG.  2017.  EPR spectroscopy on mononuclear molybdenum-containing enzymes. Future Directions in Metalloprotein and Metalloenzyme Research, Biological Magnetic Resonance, Vol. 33 (ISBN: 978-3-319-59100-1). (Hanson, G., Berliner, L.J., Eds.).:55-101., Cham: Springer International Publishing Abstract

The biological relevance of molybdenum was demonstrated in the early 1950s-1960s, by Bray, Beinert, Lowe, Massey, Palmer, Ehrenberg, Pettersson, Vänngård, Hanson and others, with ground-breaking studies performed, precisely, by electron paramagnetic resonance (EPR) spectroscopy. Those earlier studies, aimed to investigate the mammalian xanthine oxidase and avian sulfite oxidase enzymes, demonstrated the surprising biological reduction of molybdenum to the paramagnetic Mo5+. Since then, EPR spectroscopy, alongside with other spectroscopic methods and X-ray crystallography, has contributed to our present detailed knowledge about the active site structures, catalytic mechanisms and structure/activity relationships of the molybdenum-containing enzymes.
This Chapter will provide a perspective on the contribution that EPR spectroscopy has made to some selected systems. After a brief overview on molybdoenzymes, the Chapter will be focused on the EPR studies of mammalian xanthine oxidase, with a brief account on the prokaryotic aldehyde oxidoreductase, nicotinate dehydrogenase and carbon monoxide dehydrogenase, vertebrate sulfite oxidase, and prokaryotic formate dehydrogenases and nitrate reductases.

Versteeg, T, Baumann M, Weil M, Moniz AB.  2017.  Exploring emerging battery technology for grid-connected energy storage with Constructive Technology Assessment. Technological Forecasting and Social Change. 115:99-110. AbstractWebsite

The last decades have shown an increasing amount of research into expectations of science and technology. Especially for emerging technologies, expectations held by different stakeholder are guiding the direction of research and development. In this article the results of an investigation into the expectations of specific actors regarding the development of emerging battery technology for applications in the power grid are presented. It is set up as an explorative study within the framework of Constructive Technology Assessment (CTA). A number of studies since the 1990s have indicated a growing need for energy storage options in the power grid, where batteries appear to be capable of providing a range of valuable services to the grid. Cost-effectiveness on a large scale will however require considerable technical improvements. The configuration of energy storage may differ in the specific location and exploitation of the storage assets, as well as in the investments in new storage capacity. In this study the visions and expectations of several relevant actors are analysed using interviews and surveys in terms of expectations of technological development, expectations concerning stakeholder roles, and channels of interaction between the relevant actors. The results indicate a divide in expectations between the user side of the technology (the electric power industry) and the development side (academic researchers). Opinions differ with respect to the obstacles to technological development, the actors relevant in early technological development, and the most suitable channels for interaction between these actors. It follows from the theoretical background that conflicts in expectations provide the opportunity for the acceleration of technological development and adoption through stakeholder participation. Small interactive workshops, where conflicts identified in this paper are discussed, were identified as a suitable channel in order to reach consensus in visions and expectations for battery technology.

Delgado-Lima, A, Borges JP, Ferreira I, Machado A.  2017.  Fluorescent and conductive cellulose acetate-based membranes with porphyrins. Materials today Communications. 11:26-37. AbstractWebsite

The unique properties of electrospun nanofibers combined with functional compounds allow the preparation of novelty materials that can be employed in a wide range of applications. Among a vast number of polymers, Cellulose Acetate (CA) it is considered easy to electrospun and it was employed as the polymeric matrix, where free and iridium-porphyrins were incorporated. Two different solvent systems were employed according to the porphyrin used, and the best dispersion level on both the electrospun solution and the membranes, was achieved with the iridium porphyrin. The nanofibers with this porphyrin also exhibited electrical properties, while the fluorescence was quenched by the presence of specific axial ligands.