Conde, J, Ambrosone A, Sanz V, Hernandez Y, Marchesano V, Tian F, Child H, Berry {CC }, Ibarra R}{M, Baptista {PV}, Tortiglione C, {de la Fuente} {JM }.
2012.
Design of multifunctional gold nanoparticles for in vitro and in vivo gene silencing, sep. ACS Nano. 6:8316–8324., Number 9: ACS - American Chemical Society
AbstractOver the past decade, the capability of double-stranded RNAs to interfere with gene expression has driven new therapeutic approaches. Since small interfering RNA (siRNAs, 21 base pair double-stranded RNA) was shown to be able to elicit RNA interference (RNAi), efforts were directed toward the development of efficient delivery systems to preserve siRNA bioactivity throughout the delivery route, from the administration site to the target cell. Here we provide evidence of RNAi triggering, specifically silencing c-myc protooncogene, via the synthesis of a library of novel multifunctional gold nanoparticles (AuNPs). The efficiency of the AuNPs is demonstrated using a hierarchical approach including three biological systems of increasing complexity: in vitro cultured human cells, in vivo invertebrate (freshwater polyp, Hydra), and in vivo vertebrate (mouse) models. Our synthetic methodology involved fine-tuning of multiple structural and functional moieties. Selection of the most active functionalities was assisted step-by-step through functional testing that adopted this hierarchical strategy. Merging these chemical and biological approaches led to a safe, nonpathogenic, self-tracking, and universally valid nanocarrier that could be exploited for therapeutic RNAi.
Amaro, P, Fratini F, Fritzsche S, Indelicato P, Santos JP, Surzhykov A.
2012.
Parametrization of the angular correlation and degree of linear polarization in two-photon decays of hydrogenlike ions, Oct. Physical Review A. 86:042509.
AbstractThe spontaneous two-photon emission in hydrogenlike ions is investigated within the framework of second- order perturbation theory and Dirac’s equation. Special attention is paid to the angular correlation of the emitted photons as well as to the degree of linear polarization of one of the two photons, if the second is just observed under arbitrary angles. Expressions for the angular correlation and the degree of linear polarization are expanded in powers of cosine functions of the two-photon opening angle, whose coefficients depend on the atomic number and the energy sharing of the emitted photons. The effects of including higher (electric and magnetic) multipoles upon the emitted photon pairs beyond the electric-dipole approximation are also discussed. Calculations of the coefficients are performed for the transitions 2s1/2 → 1s1/2, 3d3/2 → 1s1/2, and 3d5/2 → 1s1/2, along the entire hydrogen isoelectronic sequence (1
Safari, L, Amaro P, Fritzsche S, Santos JP, Tashenov S, Fratini F.
2012.
Relativistic polarization analysis of Rayleigh scattering by atomic hydrogen, Oct. Physical Review A. 86:043405.
AbstractA relativistic analysis of the polarization properties of light elastically scattered by atomic hydrogen is performed, based on the Dirac equation and second-order perturbation theory. The relativistic atomic states used for the calculations are obtained by making use of the finite basis set method and are expressed in terms of B splines and B polynomials. We introduce two experimental scenarios in which the light is circularly and linearly polarized, respectively. For each of these scenarios, the polarization-dependent angular distribution and the degrees of circular and linear polarization of the scattered light are investigated as a function of scattering angle and photon energy. Analytical expressions are derived for the polarization-dependent angular distribution which can be used for scattering by both hydrogenic as well as many-electron systems. Detailed computations are performed for Rayleigh scattering by atomic hydrogen within the incident photon energy range 0.5 to 5 keV. Particular attention is paid to the effects that arise from higher (nondipole) terms in the expansion of the electron-photon interaction.
Safari, L, Amaro P, Fritzsche S, Santos JP, Fratini F.
2012.
Relativistic total cross section and angular distribution for Rayleigh scattering by atomic hydrogen, May. Physical Review A. 85:043406., Number 4
AbstractWe study the total cross section and angular distribution in Rayleigh scattering by hydrogen atom in the ground state, within the framework of Dirac relativistic equation and second-order perturbation theory. The relativistic states used for the calculations are obtained by making use of the finite basis-set method and expressed in terms of B splines and B polynomials. We pay particular attention to the effects that arise from higher (nondipole) terms in the expansion of the electron-photon interaction. It is shown that the angular distribution of scattered photons, while symmetric with respect to the scattering angle θ=90∘ within the electric dipole approximation, becomes asymmetric when higher multipoles are taken into account. The analytical expression of the angular distribution is parametrized in terms of Legendre polynomials. Detailed calculations are performed for photons in the energy range 0.5 to 10 keV. When possible, results are compared with previous calculations.
Sanz, V, Conde J, Ambrosone A, Hernandez Y, Marchesasno V, Estrada {GG }, Ibarra {MR }, Baptista {PV}, Tian F, Tortiglione C, {de la Fuente} {JM }.
2012.
Multifunctional gold nanoparticles for gene silencing, mar. Abstracts Of Papers Of The American Chemical Society. 243: ACS - American Chemical Society
Abstractn/a
Amaro, P, Schlesser S, Guerra M, Le Bigot E-O, Isac J-M, Travers P, Santos JP, Szabo C, Gumberidze A, Indelicato P.
2012.
Absolute Measurement of the Relativistic Magnetic Dipole Transition Energy in Heliumlike Argon, Jul. Physical Review Letters. 109:043005.
AbstractThe 1s2s 3S1 - 1s2 1S0 relativistic magnetic dipole transition in heliumlike argon, emitted by the plasma of an electron-cyclotron resonance ion source, has been measured using a double-flat crystal x-ray spectrometer. Such a spectrometer, used for the first time on a highly charged ion transition, provides absolute (reference-free) measurements in the x-ray domain. We find a transition energy of 3104.1605(77) eV (2.5 ppm accuracy). This value is the most accurate, reference-free measurement done for such a transition and is in good agreement with recent QED predictions.
c}alo Doria, G{\c, Conde J, Veigas B, Giestas L, Almeida C, c}ão MA{\c, Rosa J, Baptista {PV}.
2012.
Noble metal nanoparticles for biosensing applications, feb. Sensors. 12:1657–1687., Number 2: MDPI - Multidisciplinary Digital Publishing Institute
AbstractIn the last decade the use of nanomaterials has been having a great impact in biosensing. In particular, the unique properties of noble metal nanoparticles have allowed for the development of new biosensing platforms with enhanced capabilities in the specific detection of bioanalytes. Noble metal nanoparticles show unique physicochemical properties (such as ease of functionalization via simple chemistry and high surface-to-volume ratios) that allied with their unique spectral and optical properties have prompted the development of a plethora of biosensing platforms. Additionally, they also provide an additional or enhanced layer of application for commonly used techniques, such as fluorescence, infrared and Raman spectroscopy. Herein we review the use of noble metal nanoparticles for biosensing strategies-from synthesis and functionalization to integration in molecular diagnostics platforms, with special focus on those that have made their way into the diagnostics laboratory.