Elaheh Farjami, Rui Campos, Elena E. Ferapontova,
... in Methylene Blue-Labeled DNA Duplexes"Elaheh Farjami, Rui Campos, and Elena E. Ferapontova*Cite this: Langmuir 2016, ...
Tópico(s): Advanced biosensing and bioanalysis techniques
2016 - American Chemical Society | Langmuir
Natan Blommaerts, Nick Hoeven, Daniel Arenas Esteban, Rui Campos, Myrjam Mertens, Rituraj Borah, Antonella Glisenti, Karolien De Wael, Sara Bals, Silvia Lenaerts, Sammy W. Verbruggen, Pegie Cool,
A Ti-Beta zeolite was used in gas phase photocatalytic CO2 reduction to reduce the charge recombination rate and increase the surface area compared to P25 as commercial benchmark, reaching 607 m2 g−1. By adding Pt nanoparticles, the selectivity can be tuned toward CO, reaching a value of 92% and a turnover frequency (TOF) of 96 µmol·gcat−1·h−1, nearly an order of magnitude higher in comparison with P25. By adding Pd nanoparticles the selectivity can be shifted from CO (70% for a bare Ti-Beta zeolite), ...
Tópico(s): Catalytic Processes in Materials Science
2021 - Elsevier BV | Chemical Engineering Journal
Eduardo Nuno Almeida, André Coelho, José Ruela, Rui Campos, Manuel Ricardo,
Aerial networks, composed of Unmanned Aerial Vehicles (UAVs) acting as Wi-Fi access points or cellular base stations, are emerging as an interesting solution to provide on-demand wireless connectivity to users, when there is no network infrastructure available, or to enhance the network capacity. This article proposes a traffic-aware topology control solution for aerial networks that holistically combines the placement of UAVs with a predictive and centralized routing protocol. The synergy created ...
Tópico(s): Opportunistic and Delay-Tolerant Networks
2021 - Elsevier BV | Ad Hoc Networks
Elise Daems, Giulia Moro, Rui Campos, Karolien De Wael,
Aptamers are promising biorecognition elements with a wide applicability from therapeutics to biosensing. However, to successfully use these biomolecules, a complete characterisation of their binding performance in the presence of the target is crucial. Several multi-analytical approaches have been reported including techniques to describe kinetic and thermodynamic aspects of the aptamer-target interaction, and techniques which allow an in-depth understanding of the aptamer-target structures. Recent ...
Tópico(s): thermodynamics and calorimetric analyses
2021 - Elsevier BV | TrAC Trends in Analytical Chemistry
Rocío Cánovas, Elise Daems, Rui Campos, Sofie Schellinck, Annemieke Madder, José C. Martins, Frank Sobott, Karolien De Wael,
This work presents a proof-of-concept assay for the detection and quantification of small molecules based on aptamer recognition and electrochemiluminescence (ECL) readout. The testosterone-binding (TESS.1) aptamer was used to demonstrate the novel methodology. Upon binding of the target, the TESS.1 aptamer is released from its complementary capture probe - previously immobilized at the surface of the electrode - producing a decrease in the ECL signal after a washing step removing the released (labeled) ...
Tópico(s): Gold and Silver Nanoparticles Synthesis and Applications
2021 - Elsevier BV | Talanta
Filipe B. Teixeira, Rui Campos, Manuel Ricardo,
The Blue Economy has been growing in sectors such as offshore renewable energy, aquaculture, marine biotechnology, and deep sea mining. However, suitable wireless and mobile communications are lacking offshore. On the one hand, there is no coverage from terrestrial networks; on the other hand, satellite communications are still narrowband and expensive. Recently, the use of multi-hop airborne communications has been proposed to extend the coverage from terrestrial networks offshore but the communications ...
Tópico(s): Satellite Communication Systems
2020 - Institute of Electrical and Electronics Engineers | IEEE Access
Elisabete Fernandes, Patrícia D. Cabral, Rui Campos, George Machado, M.F. Cerqueira, Cláudia Sousa, P. P. Freitas, Jérôme Borme, Dmitri Y. Petrovykh, Pedro Alpuim,
The excellent electronic properties of single-layer graphene provide the fundamental basis for its use in advanced electronics applications. Graphene-based biosensors, however, are one of the exceptions among the applications that take advantage of the unique properties of this material, because high hydrophobicity of graphene hinders the controlled immobilization of biomolecular probes, particularly of antibodies for immunoassays. In contrast to methods that rely on aggressive chemical oxidation ...
Tópico(s): Advanced biosensing and bioanalysis techniques
2019 - Elsevier BV | Applied Surface Science
Rui Campos, Jérôme Borme, J. Rafaela L. Guerreiro, George Machado, M.F. Cerqueira, Dmitri Y. Petrovykh, Pedro Alpuim,
In this work, we develop a field-effect transistor with a two-dimensional channel made of a single graphene layer to achieve label-free detection of DNA hybridization down to attomolar concentration, while being able to discriminate a single nucleotide polymorphism (SNP). The SNP-level target specificity is achieved by immobilization of probe DNA on the graphene surface through a pyrene-derivative heterobifunctional linker. Biorecognition events result in a positive gate voltage shift of the graphene ...
Tópico(s): Molecular Junctions and Nanostructures
2019 - American Chemical Society | ACS Sensors
Rui Campos, László Kékedy‐Nagy, Zhe She, R. N. S. Sodhi, Heinz‐Bernhard Kraatz, Elena E. Ferapontova,
Electrical properties of DNA critically depend on the way DNA molecules are integrated within the electronics, particularly on DNA–electrode immobilization strategies. Here, we show that the rate of electron transport in DNA duplexes spacer-free tethered to gold via the adenosine terminal region (a dA10 tag) is enhanced compared to the hitherto reported DNA–metal electrode tethering chemistries. The rate of DNA-mediated electron transfer (ET) between the electrode and methylene blue intercalated into ...
Tópico(s): DNA and Nucleic Acid Chemistry
2018 - American Chemical Society | Langmuir
Rui Campos, George Machado, M.F. Cerqueira, Jérôme Borme, Pedro Alpuim,
Since the discovery of graphene, and due to its unique properties, we have witnessed a growing interest in the use of graphene-based devices for applications in the most diverse areas, namely in biosensing, particularly in the detection of genetic material. DNA can bind directly to graphene without the need of a linker and that makes this platform highly interesting for biosensor development. Here, electrochemical chips consisting of 6 independent gold microelectrode arrays as working electrode, ...
Tópico(s): Molecular Junctions and Nanostructures
2017 - Elsevier BV | Microelectronic Engineering
Rui Campos, S. Zhang, Jacob M. Majikes, Lucas C. C. Ferraz, Thomas H. LaBean, Mingdong Dong, Elena E. Ferapontova,
Here, a pH-induced nanomechanical switching of i-motif structures incorporated into DNA origami bound onto cysteamine-modified basal plane HOPG was electronically addressed, demonstrating for the first time the electrochemical read-out of the nanomechanics of DNA origami.
Tópico(s): Plasmonic and Surface Plasmon Research
2015 - Royal Society of Chemistry | Chemical Communications
Isabel Álvarez‐Martos, Rui Campos, Elena E. Ferapontova,
An electrochemical label-free aptasensor monitors physiological levels of dopamine with improved sensitivity when the aptamer surface coverage is optimized and with no interference from other catecholamines.
Tópico(s): Electrochemical Analysis and Applications
2015 - Royal Society of Chemistry | The Analyst
Marta Jarczewska, László Kékedy‐Nagy, Jesper S. Nielsen, Rui Campos, Jørgen Kjems, Elżbieta Malinowska, Elena E. Ferapontova,
Electrochemical assay for the universal biomarker of several cancers, urokinase plasminogen activator, uPA, based on uPA-specific fluorinated RNA aptamer and methylene blue redox indicator, allows 1 pM uPA analysis in serum, making it practically useful for clinical applications.
Tópico(s): Biosensors and Analytical Detection
2015 - Royal Society of Chemistry | The Analyst
Rui Campos, Alexander Kotlyar, Elena E. Ferapontova,
The efficiency of DNA-based bioelectronic devices strongly depends on the way DNA molecules are linked to the electronic component. Commonly, DNA is tethered to metal electrodes via an alkanethiol linker representing an additional barrier for electron transport. Here we demonstrate that the replacement of the alkanethiol linker for a phosphorothioated adenosine tag increases the rate of DNA-mediated electron transfer (ET) up to 259 s(-1), representing the highest hitherto reported rate of electrochemically- ...
Tópico(s): DNA and Nucleic Acid Chemistry
2014 - American Chemical Society | Langmuir
Rui Campos, Elena E. Ferapontova,
The Laviron formalism, developed for the case of strongly adsorbed species, is widely used for kinetic analysis of surface-confined electron transfer (ET) reactions and determination of ET rate constants ks. However, its applicability and reliability for analysis of ET between electrodes and weakly adsorbed species is unclear. Here, we studied electrochemistry of Ru hexamine (RuHex) electrostatically interacting with double-stranded (ds) DNA tethered to gold electrodes through the alkanethiol linker. ...
Tópico(s): Molecular Junctions and Nanostructures
2013 - Elsevier BV | Electrochimica Acta
Elaheh Farjami, Rui Campos, Jesper S. Nielsen, Kurt V. Gothelf, Jørgen Kjems, Elena E. Ferapontova,
The inherent redox activity of dopamine enables its direct electrochemical in vivo analysis ( Venton , B. J.; Wightman, M. R. Anal. Chem. 2003, 75, 414A). However, dopamine analysis is complicated by the interference from other electrochemically active endogenous compounds present in the brain, including dopamine precursors and metabolites and other neurotransmitters (NT). Here we report an electrochemical RNA aptamer-based biosensor for analysis of dopamine in the presence of other NT. The biosensor ...
Tópico(s): Electrochemical Analysis and Applications
2012 - American Chemical Society | Analytical Chemistry
Elaheh Farjami, Rui Campos, Elena E. Ferapontova,
Electron transfer (ET) in redox-labeled double-stranded (ds) DNA tethered to electrodes through the alkanethiol linker at either the 3' or 5' DNA end and bearing methylene blue (MB) conjugated to the opposite end of DNA is shown to depend on the DNA end of tethering to electrodes. For 3' tethering, a nanoscale diffusion of the positively charged MB redox probe (and thus of the individual DNA molecules) to the negatively charged electrode surface provided the highest apparent diffusion and ET rates as ...
Tópico(s): Biosensors and Analytical Detection
2012 - American Chemical Society | Langmuir
Tethered bilayer lipid membranes (tBLMs) are commonly used as model membranes. However, in biophysical studies, free-standing membranes (“black” lipid membranes) are more realistic models of cellular processes. In this article, we discuss the rates of electron transfer in both types of bilayer lipid membranes. These BLMs were then modified using two very important mitochondrial membrane-associated molecules: ubiquinone-10 (UQ10) and α-tocopherol (VitE). The electron transfer rates in the unmodified films ...
Tópico(s): Conducting polymers and applications
2012 - American Chemical Society | The Journal of Physical Chemistry B
Anil Suri, Rui Campos, Darius G. Rackus, Nicholas J. S. Spiller, Christine Richardson, Lars‐Olof Pålsson, Ritu Kataky,
The fabrication, characterisation and optimisation of a PVA hydrogel loaded with trehalose-protected uni-lamellar liposomes produced by freeze thaw cycles is described. By avoiding chemical and heat triggers for cross-linking of the polymer network, for the first time a system has been prepared whose pH is maintained at the physiological value, making it an excellent candidate for implantable tissue applications and in vitro studies of/mimicking biological functions. A combination of cyro-SEM (Scanning ...
Tópico(s): Polymer Surface Interaction Studies
2011 - Royal Society of Chemistry | Soft Matter
Han‐Chieh Chao, Sherali Zeadally, Yuh‐Shyan Chen, Gregorio Martínez Pérez, Reen‐Cheng Wang,
... Establishing IP Connectivity in Next Generation Networks’ by Rui Campos and Manuel Ricardo describes a new efficient mechanism, ...
Tópico(s): Software-Defined Networks and 5G
2010 - Wiley | International Journal of Communication Systems
F.A. Aguiar, Rui Campos, Changsheng Wang, Rukkiat Jitchati, Andrei S. Batsanov, Martin R. Bryce, Ritu Kataky,
A study of the charge transfer and self-assembly characteristics of two new rigid-rod molecular wires 1 and 2 assembled on polycrystalline gold electrodes was carried out using electrochemical impedance spectroscopy and cyclic voltammetry. This class of wires have precisely controlled (ca. 1.5–2.5 nm) lengths of π-conjugation, with extended HOMO and LUMO wavefunctions. While rotations can occur around the C–C single bonds, the molecules cannot isomerise or fold due to their rigid backbone structures. ...
Tópico(s): Conducting polymers and applications
2010 - Royal Society of Chemistry | Physical Chemistry Chemical Physics
Communication networks have been developed based on two networking approaches: bridging and routing. The convergence to an all-Ethernet paradigm in Personal and Local Area Networks and the increasing heterogeneity found in these networks emphasizes the current and future applicability of bridging. When bridging is used, a single active spanning tree needs to be defined. A Minimum Routing Cost Tree is known to be the optimal spanning tree if the probability of communication between any pair of network ...
Tópico(s): Mobile Ad Hoc Networks
2008 - Elsevier BV | Computer Networks
Nadeem Akhtar, Rui Campos, Cornelia Kappler, Pekka Pääkkönen, Petteri Pöyhönen, Di Zhou,
There is a growing trend towards convergence of telecommunication and data networks in order to support a richer set of services and applications. At the same time, increasing diversity and density of network access technologies has made the goal of providing connectivity anytime and anywhere a real possibility. Another important development is the emergence of small, low-complexity user owned networks, such as personal area networks and body area networks. Dynamic interworking, also known as network ...
Tópico(s): Wireless Body Area Networks
2006 - Institute of Electrical and Electronics Engineers | IEEE Vehicular Technology Conference
Rui Campos, Thomas Bechtold, Christian Röhrer,
Friction between fibers inside yarns is generally important for determining the physical behavior of textiles. The tendency of cellulosic fibers to slide in a yarn directly influences the extent of fuzz formation during abrasive treatment. This paper presents a test method to determine the slipping behavior of fibers in a yarn as a function of yarn twist. Different kinds of cellulosic fibers tested with the method include lyocell, modal, viscose, and cotton. To obtain a quantitative measure, a mathematical ...
Tópico(s): Vibration and Dynamic Analysis
2003 - SAGE Publishing | Textile Research Journal
... Prazeres, Rute Pires, Joana Soares, Mónica Dias, and Rui Campos for their beautiful work and effort as examiners. ...
Tópico(s): Psychological Testing and Assessment
2002 - Hogrefe Verlag | Rorschachiana Journal of the International Society for the Rorschach
Rui Campos, Artur Cavaco‐Paulo, Karl‐Heinz Robra, Monika Schneider, Georg Gübitz,
We have investigated the potential of fungal laccases from Polyporus sp. and Sclerotium rolfsii to degrade insoluble indigo. Evidence shows that both laccases are able to oxidize insoluble indigo to give isatin (indole-2,3-dione), which further degrades to anthranilic acid (2-aminobenzoic acid). Adsorption studies show that the laccase from Polyporus sp. has a higher affinity for indigo than the laccase of Sclerotium rolfsii. The particle size of indigo agglomerates is influenced by the origin of ...
Tópico(s): melanin and skin pigmentation
2001 - SAGE Publishing | Textile Research Journal
Jürgen Andreaus, Rui Campos, Georg Gübitz, Artur Cavaco‐Paulo,
We have found that increasing concentrations of fungal cellulases on a fabric decrease indigo staining levels. Deletion of the cellulose binding domains (CBD) from either bacterial or fungal cellulases decreases indigo staining levels and generally causes less backstaining than the entire enzyme. Increasing the concentration of cellulases with a CBD of family I on fabric decreases indigo staining, whereas increasing the concentration of cellulase with a CBD of family II has no effect on staining. ...
Tópico(s): Indoor Air Quality and Microbial Exposure
2000 - SAGE Publishing | Textile Research Journal
Rui Campos, Artur Cavaco‐Paulo, Jürgen Andreaus, Georg Gübitz,
We have studied the affinity of cellulases from different fungal origins for insoluble indigo dye. Adsorption studies have shown that "acid cellulases" from Trichoderma reesei have a higher affinity for indigo dye than "neutral cellulases" of Humicola insolens. The particle size of indigo dye agglomerates is influenced by cellulase origin and concentra tion. Evidence shows that the nonpolar residues present in higher percentages in the neutral cellulases of H. insolens seem to play an important role ...
Tópico(s): Dyeing and Modifying Textile Fibers
2000 - SAGE Publishing | Textile Research Journal
Sílvia Monteiro Fonseca, Sónia Cunha, Sara Faria, Rui Campos, Cristina Queirós,
Emergency Medical Technicians (EMTs) are at high risk for traumatic disorders, and these disorders are more likely if they resort to dysfunctional coping. However, few studies have examined how dysfunctional coping can be decreased, specifically by comparing the impact of personal characteristics, such as resilience, and of occupational factors, such as stress. This study examines the contribution of resilience and perceived stress on EMTs' dysfunctional coping.A total of 502 EMTs (66% men), with ...
Tópico(s): Posttraumatic Stress Disorder Research
2021 - Elsevier BV | International Emergency Nursing
Rui Campos, Ricardo Duarte, Filipe Sousa, Manuel Ricardo, José Ruela,
Abstract Ubiquitous Internet access is becoming a major requirement for end‐users due to the increasing number of services and applications supported over the Internet. Extending the coverage of current Wi‐Fi infrastructures installed in companies, universities and cities, has been considered a solution to help in fulfilling this requirement, namely when it comes to wireless and nomadic Internet access. This paper describes and analyses a new and simple solution, called Wi‐Fi network Infrastructure ...
Tópico(s): Opportunistic and Delay-Tolerant Networks
2010 - Wiley | Wireless Communications and Mobile Computing