Export 930 results:
Sort by: Author Title Type [ Year  (Desc)]
2014
Quaresma, P, Osório I, c}alo Dória G{\c, Carvalho {PA }, Pereira A, Langer J, Araújo {JP}, Pastoriza-Santos I, Liz-Marzán {LM }, Franco R, Baptista P, Pereira E.  2014.  Star-shaped magnetite@gold nanoparticles for protein magnetic separation and SERS detection. RSC Advances. 4:3659–3667., Number 8: RSC - Royal Society of Chemistry Abstract

A novel synthetic methodology for star shaped gold-coated magnetic nanoparticles is reported. The coating is performed in two steps: formation of gold nuclei at the surface of magnetite nanoparticles followed by growth of the gold nuclei into a complete star shaped shell. The star-shaped gold-coated magnetic nanoparticles thus obtained preserve the magnetic properties of the precursor magnetite nanoparticles, e. g. they can be easily separated with a magnet. In addition, the gold coating provides interesting optical properties while simultaneously allowing for biofunctionalization that may be advantageous for biological applications, such as (bio)detection via surface-enhanced Raman spectroscopy (SERS). As a proof-of-concept, a capping agent terminated with a nickel(II)-nitrilotriacetate group showing high affinity for histidine was used to modify the surface of the nanoparticles. The resulting star-shaped nanoparticles were used to selectively capture histidine-tagged maltose-binding protein from a crude cell extract. Finally, the performance of star shaped gold-coated magnetic nanoparticles as SERS platforms was demonstrated through the detection of Raman active dye (Astra Blue).

Ruivo, A, Muralha VSF, Aguas H, de Matos AP, Laia CAT.  2014.  Time-resolved luminescence studies of Eu3+ in soda-lime silicate glasses. Journal of Quantitative Spectroscopy & Radiative Transfer. 134:29-38. AbstractWebsite
n/a
Silva, JP, Araujo D, Jorge Parola A, Lima JC, Nabais F, Cardoso N.  2014.  Using Distinctive Colour Signatures to Capture Team Behaviour During Matches. Engineering of Sport 10. 72(James, D., Choppin, S., Allen, T., Wheat, J., Fleming, P., Eds.).:238-242. Abstract
n/a
Velasco, LF, Lima JC, Ania C.  2014.  Visible-Light Photochemical Activity of Nanoporous Carbons under Monochromatic Light. Angewandte Chemie-International Edition. 53:4146-4148., Number 16 AbstractWebsite
n/a
Bernacka-Wojcik, I, Ribeiro S, Wojcik PJ, Alves PU, Busani T, Fortunato E, Baptista PV, Covas JA, Águas H, Hilliou L, Martins R.  2014.  {Experimental optimization of a passive planar rhombic micromixer with obstacles for effective mixing in a short channel length}. RSC Advances. 4:56013–56025., Number 99 AbstractWebsite

This paper presents the performance of a passive planar rhombic micromixer with diamond-shaped obstacles and a rectangular contraction between the rhombi. The device was experimentally optimized using water for high mixing efficiency and a low pressure drop over a wide range of Reynolds numbers (Re = 0.1–117.6) by varying geometrical parameters such as the number of rhombi, the distance between obstacles and the contraction width. Due to the large amount of data generated, statistical methods were used to facilitate and improve the results of the analysis. The results revealed a rank of factors influencing mixing efficiency: Reynolds number {\textgreater} number of rhombi {\textgreater} contraction width {\textgreater} inter-obstacles distance. The pressure drop measured after three rhombi depends mainly on Re and inter-obstacle distance. The resulting optimum geometry for the low Re regime has a contraction width of 101 $μ$m and inter-obstacles distance of 93 $μ$m, while for the high Re regime a contraction width of 400 $μ$m and inter-obstacle distance of 121 $μ$m are more appropriate. These mixers enabled 80{%} mixing efficiency creating a pressure drop of 6.0 Pa at Re = 0.1 and 5.1 × 104 Pa at Re = 117.6, with a mixer length of 2.5 mm. To the authors' knowledge, the developed mixer is one of the shortest planar passive micromixers reported to date.

Araujo, A, Caro C, Mendes MJ, Nunes D, Fortunato E, Franco R, Aguas H, Martins R.  2014.  {Highly efficient nanoplasmonic SERS on cardboard packaging substrates}. NANOTECHNOLOGY. 25, Number 41 Abstract
n/a
2013
Amaro, P, Schlesser S, Guerra M, Le Bigot E, Santos JP, Szabo CI, Gumberidze A, Indelicato P.  2013.  Absolute measurements and simulations of x-ray line energies of highly charged ions with a double-crystal spectrometer, Sep 23. Physica Scripta. T156:014104. AbstractWebsite
n/a
Szabo, CI, Amaro P, Guerra M, Santos JP, Gumberidze A, Attard J, Indelicato P.  2013.  Ion temperature and x-ray line width measurements of highly charged argon ions in an ECR ion source, Sep 23. Physica Scripta. T156:014077. AbstractWebsite
n/a
Bernacka-Wójcik, I, Lopes {PA }, Vaz {AC}, Veigas {BMR}, Wojcik {PJ}, Simões P, Barata D, Fortunato {EMC}, Baptista {PMRV}, Águas {HMB}, de Martins {RFP}.  2013.  Bio-microfluidic platform for gold nanoprobe based DNA detection-application to Mycobacterium tuberculosis, oct. Biosensors & Bioelectronics. 48:87–93.: Elsevier Abstract

We have projected and fabricated a microfluidic platform for DNA sensing that makes use of an optical colorimetric detection method based on gold nanoparticles. The platform was fabricated using replica moulding technology in PDMS patterned by high-aspect-ratio SU-8 moulds. Biochips of various geometries were tested and evaluated in order to find out the most efficient architecture, and the rational for design, microfabrication and detection performance is presented. The best biochip configuration has been successfully applied to the DNA detection of Mycobacterium tuberculosis using only 3 mu l on DNA solution (i.e. 90 ng of target DNA), therefore a 20-fold reduction of reagents volume is obtained when compared with the actual state of the art.

Raje, VP, Morgado PI, Ribeiro MP, Correia IJ, Bonifacio VDB, Branco PS, Aguiar-Ricardo A.  2013.  Dual on-off and off-on switchable oligoaziridine biosensor, JAN 15. BIOSENSORS & BIOELECTRONICS. 39:64-69., Number 1 Abstract
n/a
Madeira, TI, Amorim P, Parente F, Indelicato P, Marques JP.  2013.  Analysis of the quasicontinuum band emitted by highly ionised tungsten atoms in the 4–7 nm range, Feb 31. The European Physical Journal D. 67:12., Number 1 AbstractWebsite
n/a
Conde, J, Ambrosone A, Hernandez Y, Marchesano V, Tian F, {Ricardo Ibarra} M, Baptista {PV}, Tortiglione C, {de la Fuente} {JM }.  2013.  Designing gold nanoparticles for in vivo gene silencing as a new therapeutic tool, dec. Human Gene Therapy. 24:A24–A24., Number 12: Mary Ann Leibert Abstract
n/a
Avo, J, Martins S, Jorge Parola A, Lima JC, Branco PS, Prates Ramalho JP, Pereira A.  2013.  A Family of Styrylcoumarins: Synthesis, Spectroscopic, Photophysical and Photochemical Properties, AUG. CHEMPLUSCHEM. 78:789-792., Number 8 Abstract
n/a
Guerra, M, Amaro P, Szabo CI, Gumberidze A, Indelicato P, Santos JP.  2013.  Analysis of the charge state distribution in an ECRIS Ar plasma using high-resolution x-ray spectra, Apr 01. Journal of Physics B: Atomic, Molecular and Optical Physics. 46:065701., Number 6 AbstractWebsite
n/a
Almeida, G, Gonzalez J, Rosado L, Vilaça P, Santos TG.  2013.  Advances in NDT and materials characterization by eddy currents, 2013. 46th CIRP Conference on Manufacturing Systems, CIRP CMS 2013. 7:359-364., Setubal Abstract
n/a
Geng, Y, Almeida PL, Fernandes SN, Cheng C, Palffy-Muhoray P, Godinho MH.  2013.  A cellulose liquid crystal motor: a steam engine of the second kind, 2013. 3(1):1028. AbstractWebsite

The salient feature of liquid crystal elastomers and networks is strong coupling between orientational order and mechanical strain. Orientational order can be changed by a wide variety of stimuli, including the presence of moisture. Changes in the orientation of constituents give rise to stresses and strains, which result in changes in sample shape. We have utilized this effect to build soft cellulose-based motor driven by humidity. The motor consists of a circular loop of cellulose film, which passes over two wheels. When humid air is present near one of the wheels on one side of the film, with drier air elsewhere, rotation of the wheels results. As the wheels rotate, the humid film dries. The motor runs so long as the difference in humidity is maintained. Our cellulose liquid crystal motor thus extracts mechanical work from a difference in humidity.

Avo, J, Martins S, Parola AJ, Lima JC, Branco PS, Ramalho JPP, Pereira A.  2013.  A Family of Styrylcoumarins: Synthesis, Spectroscopic, Photophysical and Photochemical Properties, 2013. Chempluschem. 78:789-792. AbstractWebsite
n/a
Geng, Y, Seč D, Almeida PL, Lavrentovich OD, Žumer S, Godinho MH.  2013.  Liquid crystal necklaces: cholesteric drops threaded by thin cellulose fibres, 2013. Soft Matter. 9(33):7928-7933.: The Royal Society of Chemistry AbstractWebsite

Liquid crystals in confined geometries exhibit numerous complex structures often including topological defects that are controlled by the nematic elasticity, chirality and surface anchoring. In this work, we study the structures of cholesteric droplets pierced by cellulose fibres with planar anchoring at droplet and fibre surfaces. By varying the temperature we demonstrate the role of twisting power and droplet diameter on the equilibrium structures. The observed structures are complemented by detailed numerical simulations of possible director fields decorated by defects. Three distinct structures, a bipolar and two ring configurations, are identified experimentally and numerically. Designing cholesteric liquid crystal microdroplets on thin long threads opens new routes to produce fibre waveguides decorated with complex microresonators.

Geng, Y, Almeida PL, Feio GM, Figueirinhas JL, Godinho MH.  2013.  Water-Based Cellulose Liquid Crystal System Investigated by Rheo-NMR, 2013. MacromoleculesMacromolecules. 46(11):4296-4302.: American Chemical Society AbstractWebsite

Water-based cellulose cholesteric liquid crystalline phases at rest can undergo structural changes induced by shear flow. This reflects on the deuterium spectra recorded when the system is investigated by rheo-nuclear magnetic resonance (rheo-NMR) techniques. In this work, the model system hydroxypropylcellulose (HPC)+water is revisited using rheo-NMR to clarify unsettled points regarding its behavior under shear and in relaxation. The NMR spectra allow the identification of five different stable ordering states, within shear and relaxation, which are well integrated in a mesoscopic picture of the system’s structural evolution under shear and relaxation. This picture emerging from the large body of studies available for this system by other experimental techniques, accounts well for the NMR data and is in good agreement with the three distinct regions of steady shear flow recognized for some lyotropic LC polymers. Shear rates in between 0.1 and 1.0 s–1 where investigated using a Taylor–Couette flow and deuterated water was used as solvent for the deuterium NMR (DNMR) analysis.Water-based cellulose cholesteric liquid crystalline phases at rest can undergo structural changes induced by shear flow. This reflects on the deuterium spectra recorded when the system is investigated by rheo-nuclear magnetic resonance (rheo-NMR) techniques. In this work, the model system hydroxypropylcellulose (HPC)+water is revisited using rheo-NMR to clarify unsettled points regarding its behavior under shear and in relaxation. The NMR spectra allow the identification of five different stable ordering states, within shear and relaxation, which are well integrated in a mesoscopic picture of the system’s structural evolution under shear and relaxation. This picture emerging from the large body of studies available for this system by other experimental techniques, accounts well for the NMR data and is in good agreement with the three distinct regions of steady shear flow recognized for some lyotropic LC polymers. Shear rates in between 0.1 and 1.0 s–1 where investigated using a Taylor–Couette flow and deuterated water was used as solvent for the deuterium NMR (DNMR) analysis.

Almeida, T.  2013.  Art/Science: A case study of luminescent vitreous materials. Proceedings of the World Congress on Communication and Arts. , Gellong, Australia
Qu, X, Latino DA, Aires-de-Sousa J.  2013.  A big data approach to the ultra-fast prediction of DFT-calculated bond energies. J. Cheminform.. 5(1):34.Website
Ruivo, A, Almeida T, Quintas F, Wiley R, Troeira M, Paulino N, Laia CAT, Queiroz CA, de Matos PA.  2013.  Colours of Luminescent Glasses for Artworks. Proceedings of 12th International AIC Colour Congress. :885-888., Newcastle Gateshead, UK
Sousa, P, Amado MP.  2013.  Construção Sustentável – Contributos para um Sistema de Certificação Lusófono. 2º Congresso Internacional da habitação no Espaço Lusófono. :252-253., Lisboa, PT: LNEC
Correia de Freitas, J, Amado MP.  2013.  Crowdfunding in urban planning: Opportunities and Obstacles. RC 43 Conference 2013 At home in the housing market. :151-156., Amesterdam, NL: Centre for Urban Studies University of Amsterdam, The Netherlands
Ramalhete, I, Amado MP.  2013.  Designing model house based on the Cradle-to-Cradle methodology. SB 13 PORTUGAL - CONTRIBUTION OF SUSTAINABLE BUILDING TO MEET EU 20-20-20 TARGETS. :825-836., Guimaraes, PT: iiSBE PORTUGAL
loading