Fast optoelectric printing of plasmonic nanoparticles into tailored circuits

Plasmonic nanoparticles are able to control light at nanometre-scale by coupling electromagnetic fields to the oscillations of free electrons in metals. Deposition of such nanoparticles onto substrates with tailored patterns is essential, for example, in fabricating plasmonic structures for enhanced sensing. This work presents an innovative micro-patterning technique, based on optoelectic printing, for fast and straightforward fabrication of curve-shaped circuits of plasmonic nanoparticles deposited onto a transparent electrode often used in optoelectronics, liquid crystal displays, touch screens, etc. We experimentally demonstrate that this kind of plasmonic structure, printed by using silver nanoparticles of 40 nm, works as a plasmonic enhanced optical device allowing for polarized-color-tunable light scattering in the visible. These findings have potential applications in biosensing and fabrication of future optoelectronic devices combining the benefits of plasmonic sensing and the functionality of transparent electrodes

Segmentation Thématique : Unité du Texte vs Indépendance des Segments

Date du colloque : 01/2008National audienc

Bacterial size matters:Multiple mechanisms controlling septum cleavage and diplococcus formation are critical for the virulence of the opportunistic pathogen Enterococcus faecalis

Enterococcus faecalis is an opportunistic pathogen frequently isolated in clinical settings. This organism is intrinsically resistant to several clinically relevant antibiotics and can transfer resistance to other pathogens. Although E. faecalis has emerged as a major nosocomial pathogen, the mechanisms underlying the virulence of this organism remain elusive. We studied the regulation of daughter cell separation during growth and explored the impact of this process on pathogenesis. We demonstrate that the activity of the AtlA peptidoglycan hydrolase, an enzyme dedicated to septum cleavage, is controlled by several mechanisms, including glycosylation and recognition of the peptidoglycan substrate. We show that the long cell chains of E. faecalis mutants are more susceptible to phagocytosis and are no longer able to cause lethality in the zebrafish model of infection. Altogether, this work indicates that control of cell separation during division underpins the pathogenesis of E. faecalis infections and represents a novel enterococcal virulence factor. We propose that inhibition of septum cleavage during division represents an attractive therapeutic strategy to control infections

Metal nanostars: Stochastic optimization of resonant scattering properties.

In this work we make use of a bio-inspired stochastic technique to find the optimal geometry that maximizes, for a fixed wavelength, the scattering cross section of a bidimensional metal nanostar. To solve the scattering problem, we employ a rigorous numerical method based on Green’s theorem using surface integral equations. It is shown that the optimization procedure converges to a nanostar geometry that exhibits a resonance at or near the given wavelength. The influence of the illumination conditions, the effect of geometries found on the near-field features, and the possibilities and limitations of our approach are discussed through some numerical experiments.J.A. Sánchez-Gil acknowledges support from both the Spain Ministerio de Ciencia e Innovación through the Consolider-Ingenio project EMET (CSD2008-00066) and NANOPLAS (FIS2009-11264), and from the Comunidad de Madrid (grant MICROSERES P2009/TIC-1476).Peer Reviewe

Foot ailments during Hajj: A short report

AbstractA study of ailments of the feet in pilgrims of Hajj revealed that 31% of them suffered from blisters, and the prevalence was five times higher in females. The presence of comorbidity (diabetes, obesity and advanced age) warrants immediate attention to them to avoid serious complications

Nutritional quality of protein concentrates from Moringa Oleifera leaves and in vitro digestibility

The nutritional value and digestibility of leaf proteins is still a major issue. Therefore, the goal of this work was to optimize the production of a protein concentrate (PC) from Moringa Oleifera defatted leaves (MODL) by enzymatic extraction using Viscozyme L and evaluate its nutritional quality and digestibility. Protein extraction conditions were screened using a factorial design. Enzyme/Substrate ratio and pH had no significant effect, whereas, the significant variables, temperature (°C), enzyme concentration and incubation time (h) were optimized by central composite design (CCD). PC contained 55.7% of proteins with a balanced amino acid profile when compared with MODL and higher content of essential amino acids (EAAs) (488.6-402.9 mg/g of protein respectively). Improvement on protein digestibility was observed for MODL compared to PC (64.75-99.86% respectively) and higher protein digestibility corrected amino acid score (PDCAAS) (62.10-91.41% respectively). PC meets FAO protein quality expectations.Highlights: Sustainable extraction of leaf proteins with the low temperatures/incubation times; Moringa protein concentrate has higher essential amino acids index than whole leaves; Protein isolation and concentration enhanced its nutritional value and digestibility.This work received financial support from FEDER funds and National Funds (FCT/MEC, Fundação para a Ciência e Tecnologia and Ministério da Educação e Ciência) project PTDC/OCE-ETA/32567/2017- MOR2020. Tassadit Benhammouche thanks the PhD Grant awarded by the University of Porto under the Erasmus + Program in coordination with University of Bejaia Algeria.info:eu-repo/semantics/publishedVersio

Efficient Subgroup Discovery Through Auto-Encoding

Current subgroup discovery methods struggle to produce good results for large real-life datasets with high dimensionality. Run times can become high and dependencies between attributes are hard to capture. We propose a method in which auto-encoding is applied for dimensionality reduction before subgroup discovery is performed. In an experimental study, we find that auto-encoding increases both the quality and coverage for our dataset with over 500 attributes. On the dataset with over 250 attributes and the one with the most instances, the coverage improves, while the quality remains similar. For smaller datasets, quality and coverage remain similar or see a minor decrease. Additionally, we greatly improve the run time for each dataset-algorithm combination; for the datasets with over 250 and 500 attributes run times decrease by a factor of on average 150 and 200, respectively. We conclude that dimensionality reduction is a promising method for subgroup discovery in datasets with many attributes and/or a high number of instances

Respiratory Viruses and Bacteria among Pilgrims during the 2013 Hajj

Pilgrims returning from the Hajj might contribute to international spreading of respiratory pathogens. Nasal and throat swab specimens were obtained from 129 pilgrims in 2013 before they departed from France and before they left Saudi Arabia, and tested by PCR for respiratory viruses and bacteria. Overall, 21.5% and 38.8% of pre-Hajj and post-Hajj specimens, respectively, were positive for ≥1 virus (p = 0.003). One third (29.8%) of the participants acquired ≥1 virus, particularly rhinovirus (14.0%), coronavirus E229 (12.4%), and influenza A(H3N2) virus (6.2%) while in Saudi Arabia. None of the participants were positive for the Middle East respiratory syndrome coronavirus. In addition, 50.0% and 62.0% of pre-Hajj and post-Hajj specimens, respectively, were positive for Streptococcus pneumoniae (p = 0.053). One third (36.3%) of the participants had acquired S. pneumoniae during their stay. Our results confirm high acquisition rates of rhinovirus and S. pneumoniae in pilgrims and highlight the acquisition of coronavirus E229