97 research outputs found
Optical binding-driven micropatterning and photo-sculpting with silver nanorods
Controlling the nano- and micropatterning of metal structures is an important requirement for various technological applications in photonics and biosensing. This work presents a method for controllably creating silver micropatterns by laser-induced photosculpting. Photosculpting is driven by plasmonic interactions between pulsed laser radiation and silver nanorods (AgNRs) in aqueous suspension; this process leads to optical binding forces transporting the AgNRs in the surroundings, while electronic thermalization results in photooxidation, melting, and ripening of the AgNRs into well-defined 3D structures. This work call these structures Airy castles due to their structural similarity with a diffraction-limited Airy disk. The photosculpted Airy castles contain emissive Ag nanoclusters, allowing for the visualization and examination of the aggregation process using luminescence microscopy. This work comprehensively examines the factors that define the photosculpting process, namely, the concentration and shape of the AgNRs, as well as the energy, power, and repetition rate of the laser. Finally, this work investigates the potential applications by measuring the metal-enhanced luminescence of a europium-based luminophore using Airy castles.MCIN/AEI/10.13039/501100011033 and the European Regional Development Fund (ERDF). Grant Number: CTQ2017-85658-R
MCIN/AEI/10.13039/501100011033. Grant Number: PID2020-114256RB-I00
European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie. Grant Number: 101007934
Fundação para a Ciência e a Tecnologia, I.P. Grant Numbers: UIDB/00100/2020, 2022.04076.PTD
Density biases and temperature relations for DESIRED HII regions
We present a first study based on the analysis of the DEep Spectra of Ionized
REgions Database (DESIRED). This is a compilation of 190 high signal-to-noise
ratio optical spectra of HII regions and other photoionized nebulae, mostly
observed with 8-10m telescopes and containing 29380 emission lines. We
find that the electron density ---- of the objects is underestimated
when [SII] and/or [OII] are
the only density indicators available. This is produced by the non-linear
density dependence of the indicators in the presence of density
inhomogeneities. The average underestimate is cm in
extragalactic HII regions, introducing systematic overestimates of ([OII]) and ([SII]) compared to ([NII]). The
high-sensitivity of [OII]
and [SII] to density makes them
more suitable for the diagnosis of the presence of high-density clumps. If
([NII]) is adopted, the density underestimate has a small impact in
the ionic abundances derived from optical spectra, being limited to up to
0.1 dex when auroral [SII] and/or [OII] lines are used. However, these
density effects are critical for the analysis of infrared fine structure lines,
such as those observed by the JWST in local star forming regions, implying
strong underestimates of the ionic abundances. We present temperature relations
between ([OIII]), ([ArIII]), ([SIII]) and
([NII]) for the extragalactic HII regions. We confirm a non-linear
dependence between ([OIII])-([NII]) due to a more rapid
increase of ([OIII]) at lower metallicities.Comment: Accepted for publication in MNRA
A multicomponent reaction platform towards multimodal near-infrared BODIPY dyes for STED and fluorescence lifetime imaging
We report a platform combining multicomponent reaction synthesis and automated cell-based screening to develop biocompatible NIR-BODIPY fluorophores. From a library of over 60 fluorophores, we optimised compound NIRBD-62c as a multimodal probe with suitable properties for STED super-resolution and fluorescence lifetime imaging. Furthermore, we employed NIRBD-62c for imaging trafficking inside cells and to examine how pharmacological inhibitors can alter the vesicular traffic between intracellular compartments and the plasma membrane
Exchangeable Self-Assembled Lanthanide Antennas for PLIM Microscopy
This work was supported by grant PID2020-114256RB-I00 funded by AEI/10.13039/501100011033;grant PID2019-104366RB-C22fundedby AEI/10.13039/501100011033/FEDER“Una manera de hacer Europa”;grants P21_00212,A-FQM-386-UGR20 and 2021/00627/001-FEDER_UJA_2020 funded by FEDER/Junta de Andalucía-Consejería deTransformación Económica,Industria,Conocimiento y Uni-versidades; CSIC grant 202180E073; and Acción 1 from Universidad de Jaén. Funding for open access charge: Universidad de Granada/CBUA.A.R.-A.thanks the spanish Ministerio de Educación y Formación Profesional for the FPUPh.D. scholarship.Peer reviewe
Measurement of Typhim Vi IgG as a Diagnostic Tool to Determine Anti-polysaccharide Antibody Production Deficiency in Children
Background: The assessment of specific polysaccharide antibody production plays a pivotal role in the diagnosis of humoral primary immunodeficiencies (PID). The response to 23-valent pneumococcal vaccine (PPV) remains the gold standard for the diagnosis of polysaccharide antibodies. However, in Spain, the interpretation of pure polysaccharide 23-valent immunization is hampered by the high endemicity of pneumococcal disease and the generalization of the 13-valent adjuvant pneumococcal vaccination. Specific Typhim Vi vaccination (TV) immunoglobulin G IgG response to immunization is useful in adult PID, but there is no data regarding children.Objectives: To evaluate the clinical utility of TV IgG production as a diagnostic tool to determine anti-polysaccharide antibody production deficiency in children, when the response to PPV is unclear and isolated determination of serotypes is unfeasible.Methods: We conducted a single-institution prospective observational study on 61 children with recurrent infections. Baseline specific antibodies against PPV and TV were evaluated. In 28 children (46%), the response to the production of antibodies confirmed a clinical suspicion of humoral PID, and they were therefore immunized with 23-valent pneumococcal vaccine and Typhim Vi. Both specific antibody responses were measured by ELISA (The Binding Site Group Ltd, Birmingham, UK) using previously published cut-offs.Results: Seventy percent of the 61 children displayed baseline PPV IgG > 27 mg/L, whereas only 8% showed TV IgG > 28 U/mL (p < 0.0001). Twenty-one of 28 children (75%) achieved a 3-fold increase in post-vaccination TV IgG levels, whereas only 3% achieved a 4-fold increase in PPV IgG post vaccination, mainly due to high baseline PPV IgG titers. When we classified children according to their response to TV as responders or non-responders and compared this with the well-known clinical warning signs of the Jeffrey Modell Foundation. The proportions of children with history of pneumonia and the need for intravenous antibiotics were significantly higher in TV IgG non-responders than in TV IgG responders (p = 0.02 and p = 0.01, respectively).Conclusion: Response to TV can be considered an ancillary diagnostic tool to determine polysaccharide antibodies in children, particularly when isolated determination of pneumococcal serotypes is not feasible. TV provides a useful asset for clinicians in the era of conjugate PPV vaccination, with clinical relevance. Further research is warranted for validation
Neutral pathways and heat flux widths in vertical- and horizontal-target EDGE2D-EIRENE simulations of JET
This paper further analyses the EDGE2D-EIRENE simulations presented by Chankin et al (2017 Nucl. Mater. Energy 12 273), of L-mode JET plasmas in vertical-vertical (VV) and Vertical-horizontal (VH) divertor configurations. As expected, the simulated outer divertor ionisation source peaks near the separatrix in VV and radially further out in VH. We identify the reflections of recycled neutrals from lower divertor tiles as the primary mechanism by which ionisation is concentrated on the outer divertor separatrix in the VV configuration. These lower tile reflection pathways (of neutrals from the outer divertor, and to an even greater extent from the inner divertor) dominate the outer divertor separatrix ionisation. In contrast, the lower-tile-reflection pathways are much weaker in the VH simulation and its outer divertor ionisation is dominated by neutrals which do not reflect from any surfaces. Interestingly, these differences in neutral pathways give rise to strong differences in the heat flux density width λq at the outer divertor entrance: λq = 3.2 mm in VH compared to λq = 11.8 mm in VV. In VH, a narrow channel exists in the near scrape-off-layer (SOL) where the convected heat flux, driven by strong Er × B flow and thermoelectric current, dominates over the conducted heat flux. The width of this channel sets λq and is determined by the radial distance between the separatrix and the ionisation peak in the outer divertor
Investigation into the formation of the scrape-off layer density shoulder in JET ITER-like wall L-mode and H-mode plasmas
The low temperature boundary layer plasma (Scrape-Off-Layer or SOL) between the hot core and the surrounding vessel determines the level of power-loading, erosion and implantation of material surfaces, and thus the viability of tokamak-based fusion as an energy source. This study explores mechanisms affecting the formation of flattened density profiles, so-called ‘density shoulders’, in the low-field side (LFS) SOL, which modify ion and neutral fluxes to surfaces – and subsequent erosion. There is evidence against local enhancement of ionization inducing shoulder formation. We find that increases in SOL parallel resistivity, Λdiv (=[L||νei Ωi ]/cs Ωe), postulated to lead to shoulder growth through changes in SOL turbulence characteristics, correlates with increases in upstream SOL shoulder amplitude, As only under a subset of conditions (D2-fuelled L-mode density scans with outer strike point on the horizontal target). Λdiv fails to correlate with As for cases of N2 seeding or during sweeping of the strike point across the horizontal target. The limited correlation of Λdiv with As was also found for H-mode discharges. Thus, while Λdiv above a threshold of ~1 may be necessary for shoulder formation and/or growth, another shoulder mechanism is required. More significantly we find that in contrast to parallel resistivity, outer divertor recycling as quantified by the total outer divertor Balmer Dα emission, I-Dα, does scale with shoulder amplitude where Λdiv does and even where Λdiv fails. Divertor recycling could lead to SOL density shoulder formation through: a) reducing the parallel to the field flow (loss) of ions out of the SOL to the divertor; and b) changes in radial electric fields which lead to ExB poloidal flows as well as potentially affecting the SOL turbulence birth characteristics. Thus changes in divertor recycling may be the sole process in bringing about SOL density shoulders or in tandem with parallel resistivity
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