Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions

Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p < 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics

One-Dimensional Metal Oxide Nanostructures for Chemical Sensors

The fabrication of chemical sensors based on one-dimensional (1D) metal oxide semiconductor (MOS) nanostructures with tailored geometries has rapidly advanced in the last two decades. Chemical sensitive 1D MOS nanostructures are usually configured as resistors whose conduction is altered by a charge-transfer process or as field-effect transistors (FET) whose properties are controlled by applying appropriate potentials to the gate. This chapter reviews the state-of-the-art research on chemical sensors based on 1D MOS nanostructures of the resistive and FET types. The chapter begins with a survey of the MOS and their 1D nanostructures with the greatest potential for use in the next generation of chemical sensors, which will be of very small size, low-power consumption, low-cost, and superior sensing performance compared to present chemical sensors on the market. There follows a description of the 1D MOS nanostructures, including composite and hybrid structures, and their synthesis techniques. And subsequently a presentation of the architectures of the current resistive and FET sensors, and the methods to integrate the 1D MOS nanostructures into them on a large scale and in a cost-effective manner. The chapter concludes with an outlook of the challenges facing the chemical sensors based on 1D MOS nanostructures if their massive use in sensor networks becomes a reality

Tin Dioxide-Graphene Based Chemi-Device for NO2 Detection in the Sub ppm Range

Chemical nanodevices based on tin dioxide, graphene and a mixture of both materials were developed and characterized for NO2 detection at low concentrations. The chemiresistors were prepared by both electrospinning and drop casting. The films morphologies were investigated by scanning electron microscopy (SEM). The devices response to sub-ppm NO2 concentrations was measured from room temperature up to 300 °C. An improvement in the performance in terms of sensitivity and response time, as well as higher responses at room temperature, was obtained when a mixture of these materials is used.Authors want to thank Spanish Ministry of Economy and Competitiveness for supporting the project TEC2013-48147-C

Assessment of a Cylindrical and a Rectangular Plate Differential Mobility Analyzer for Size Fractionation of Nanoparticles at High-Aerosol Flow Rates

<div><p>An existing differential mobility analyzer (DMA) of cylindrical electrodes and a novel DMA of rectangular plate electrodes are demonstrated for size fractionation of nanoparticles at high-aerosol flow rates in this work. The two DMAs are capable of delivering monodisperse size selected nanoparticles (SMPS <i>σ_g</i> < 1.1) at gas flow rates ranging from 200 slm to 500 slm. At an aerosol flow rate of 200 slm, the maximum attainable particle mean size is of about 20 nm for the cylindrical DMA and of nearly 50 nm for the rectangular plate DMA. The number concentration of the monodisperse nanoparticles delivered by the high-flow DMAs spans from 10⁴ cm⁻³ to 10⁶ cm⁻³ depending upon the particle mean size and particle size dispersion.</p> <p>Copyright 2014 American Association for Aerosol Research</p> </div

A green dry route for antibacterial nanofinishing of textiles

In this paper, an aerosol-based process is proven for imparting antibacterial property to textiles. Nanoparticles of copper and silver are produced by means of glow discharge between two electrodes in nitrogen at atmospheric pressure and passed through fabrics of cotton and polyester which act as filter media. The bactericidal performance of the nanofinished fabrics is assessed against Gram-positive Staphylococcus aureus and Gramnegative Klebsiella pneumonia bacteria. Nanoparticle loads of about 0.3 g/m2 (~ 0.2 wt %) give strong antibacterial activity to the fabrics regardless of particle composition and size. Higher loads do not enhance the bactericide property but affect the colour and hand feel of the fabrics. Cotton and polyester fabrics with low loads (<0.3 g/m2) of small silver nanoparticles (<10 nm) show different bactericidal behaviour. Polyester fabrics attain good antibacterial activity for SA and KP, which is retained (KP) or decreases (SA) after washing. Cotton fabrics show hardly bactericidal property but, in some cases, it increases after washing

Development and Field Validation of Low-Cost Metal Oxide Nanosensors for Tropospheric Ozone Monitoring in Rural Areas

International audienceThis work describes the technical features and the performance of two different types of metal-oxide semiconductor sensors, based on ZnO:Ga thin films and SnO2-G nanofibrous layers, for tropospheric ozone monitoring in ambient air. These nanostructures were tested and compared with commercial metal-oxide semiconductor sensors under controlled laboratory conditions and in a field campaign during summer 2021 in Monfragüe National Park (western Spain). The paper also details the design of the electronic device developed for this purpose. A machine learning algorithm based on Support Vector Regression (SVR) allowed the conversion of the resistive values into ozone concentration, which was evaluated afterward. The results showed that the manufactured sensors performed similarly to the commercial sensors in terms of R2 (0.94 and 0.95) and RMSE (5.21 and 4.83 μg·m−3). Moreover, a novel uncertainty calculation based on European guides for air quality sensor testing was conducted, in which the manufactured sensors outperformed the commercial ones

Green and Sustainable Manufacture of Ultrapure Engineered Nanomaterials

© 2020 by the authors.Nanomaterials with very specific features (purity, colloidal stability, composition, size, shape, location…) are commonly requested by cutting-edge technologic applications, and hence a sustainable process for the mass-production of tunable/engineered nanomaterials would be desirable. Despite this, tuning nano-scale features when scaling-up the production of nanoparticles/nanomaterials has been considered the main technological barrier for the development of nanotechnology. Aimed at overcoming these challenging frontier, a new gas-phase reactor design providing a shorter residence time, and thus a faster quenching of nanoclusters growth, is proposed for the green, sustainable, versatile, cost-effective, and scalable manufacture of ultrapure engineered nanomaterials (ranging from nanoclusters and nanoalloys to engineered nanostructures) with a tunable degree of agglomeration, composition, size, shape, and location. This method enables: (1) more homogeneous, non-agglomerated ultrapure Au-Ag nanoalloys under 10 nm; (2) 3-nm non-agglomerated ultrapure Au nanoclusters with lower gas flow rates; (3) shape-controlled Ag NPs; and (4) stable Au and Ag engineered nanostructures: nanodisks, nanocrosses, and 3D nanopillars. In conclusion, this new approach paves the way for the green and sustainable mass-production of ultrapure engineered nanomaterials.This research was funded by the European Union’s Seventh Framework Programme (EU FP7) under grant agreement number 280765 (BUONAPART-e), the PROMETEO Program (Ref.2019/123) - Generalitat Valenciana, FEDER/Ministerio de Ciencia e Innovación– Agencia Estatal de Investigación/Ref.ICTS-2017-28-UPV-9 and co-funded by European Union’s operative program FEDER/Comunitat Valenciana 2014-2020. C.G.-M. acknowledges support from Agencia Estatal de Investigación AEI/FEDER (EU) under Grant Agreement TEC2015-73581-JIN PHUTURE. E.P.-C. acknowledges support from the Spanish Ministry of Economy and Competiveness (MINECO) under Grant Agreement FJCI-2015-27228 and TEC2017-92037-EXPPeer reviewe