Synthetic wastewaters treatment by electrocoagulation to remove silver nanoparticles produced by different routes

International audienceNanoscience is a field that has stood out in recent years. The accurate long-term health and environmental risks associated with these emerging materials are unknown. Therefore, this work investigated how to eliminate silver nanoparticles (AgNPs) from synthetic effluents by electrocoagulation (EC) due to the widespread use of this type of nanoparticle (NP) in industry and its potential inhibition power over microorganisms responsible for biological treatment in effluent treatment plants. Synthesized AgNPs were studied via four different routes by chemical reduction in aqueous solutions to simulate the chemical variations of a hypothetical industrial effluent, and efficiency conditions of the EC treatment were determined. All routes used silver nitrate as the source of silver ions, and two synthesis routes were studied with sodium citrate as a stabilizer. In route I, sodium citrate functioned simultaneously as the reducing agent and stabilizing agent, whereas route II used sodium borohydride as a reducing agent. Route III used d-glucose as the reducing agent and sodium pyrophosphate as the stabilizer; route IV used sodium pyrophosphate as the stabilizing agent and sodium borohydride as the reducing agent. The efficiency of the EC process of the different synthesized solutions was studied. For route I, after 85 min of treatment, a significant decrease in the plasmon resonance peak of the sample was observed, which reflects the efficiency in the mass reduction of AgNPs in the solution by 98.6%. In route II, after 12 min of EC, the absorbance results reached the detection limit of the measurement instrument, which indicates a minimum reduction of 99.9% of AgNPs in the solution. During the 4 min of treatment in route III, the absorbance intensities again reached the detection limit, which indicates a minimum reduction of 99.8%. In route IV, after 10 min of treatment, a minimum AgNP reduction of 99.9% was observed. Based on these results, it was possible to verify that the solutions containing citrate considerably increased the necessary times required to eliminate AgNPs from the synthesized effluent, whereas solutions free of this reagent showed better results on floc formation and, therefore, are best for the treatment. The elimination of AgNPs from effluents by EC proved effective for the studied routes

A screening mechanism for extra W and Z gauge bosons

We generalize a previous construction of a fermiophobic model to the case of more than one extra $W$ and $Z$ gauge bosons. We focus in particular on the existence of screening configurations and their implication on the gauge boson mass spectrum. One of these configurations allows for the existence of a set of relatively light new gauge bosons, without violation of the quite restrictive bounds coming from the $\rho_{\rm NC}$ parameter. The links with Bess and degenerate Bess models are also discussed. Also the signal given here by this more traditional gauge extension of the SM could help to disentangle it from the towers of Kaluza-Klein states over $W$ and $Z$ gauge bosons in extra dimensions.Comment: 23 pages, 1 figure, extended discussion on precision tests. To appear in International Journal of Modern Physics

Feasibility of diffusion and probabilistic white matter analysis in patients implanted with a deep brain stimulator.

Deep brain stimulation (DBS) for Parkinson\u27s disease (PD) is an established advanced therapy that produces therapeutic effects through high frequency stimulation. Although this therapeutic option leads to improved clinical outcomes, the mechanisms of the underlying efficacy of this treatment are not well understood. Therefore, investigation of DBS and its postoperative effects on brain architecture is of great interest. Diffusion weighted imaging (DWI) is an advanced imaging technique, which has the ability to estimate the structure of white matter fibers; however, clinical application of DWI after DBS implantation is challenging due to the strong susceptibility artifacts caused by implanted devices. This study aims to evaluate the feasibility of generating meaningful white matter reconstructions after DBS implantation; and to subsequently quantify the degree to which these tracts are affected by post-operative device-related artifacts. DWI was safely performed before and after implanting electrodes for DBS in 9 PD patients. Differences within each subject between pre- and post-implantation FA, MD, and RD values for 123 regions of interest (ROIs) were calculated. While differences were noted globally, they were larger in regions directly affected by the artifact. White matter tracts were generated from each ROI with probabilistic tractography, revealing significant differences in the reconstruction of several white matter structures after DBS. Tracts pertinent to PD, such as regions of the substantia nigra and nigrostriatal tracts, were largely unaffected. The aim of this study was to demonstrate the feasibility and clinical applicability of acquiring and processing DWI post-operatively in PD patients after DBS implantation. The presence of global differences provides an impetus for acquiring DWI shortly after implantation to establish a new baseline against which longitudinal changes in brain connectivity in DBS patients can be compared. Understanding that post-operative fiber tracking in patients is feasible on a clinically-relevant scale has significant implications for increasing our current understanding of the pathophysiology of movement disorders, and may provide insights into better defining the pathophysiology and therapeutic effects of DBS

Association Mapping Considering Allele Dosage: An Example of Forage Traits in an Interspecific Segmental Allotetraploid Urochloa spp.

The breeding process in tropical segmental allopolyploid forage Urochloa is challenging due to the complex genetic control of the traits. Knowledge about genes associated with forage traits, expressed in the different cutting seasons, are extremely useful to support breeding programs and development of new cultivars. Thus, the aims of our study were (i) to identify genomic regions related to forage traits through genomewide association studies (GWAS), and (ii) to verify the influence of allele dosage on these results. A panel of 272 genotypes of Urochloa spp. [U. brizantha (Hoscht. ex A. Rich.) R. Webster ´ U. ruziziensis (Hoscht. ex A. Rich.) R. Webster] was evaluated in both the wet and dry seasons. The GWAS analyses were performed with 26,535 single nucleotide polymorphisms (SNPs) obtained by genotyping-by-sequencing (GBS) using diploid and tetraploid allele dosage configurations. Furthermore, we evaluated scenarios including additive, dominance, and epistatic effects. Seven candidate genomic regions associated with the main forage traits of Urochloa spp. were identified. The importance of the diploid and tetraploid molecular configuration in GWAS analyses for segmental allopolyploid species was demonstrated to identify the genomic behavior of important regions. Results demonstrated that it is possible to identify the same regions using both ploidy configurations; however, in some cases, the allele substitution effect can be biased mainly for regions with dominance and epistatic effects. Finally, this study contributes to the understanding of genetic control of tropical forage traits and genomics to accelerate the selection and reduce the cost to release new cultivars

The Accelerated Universe and the Moon

Cosmologically motivated theories that explain small acceleration rate of the Universe via modification of gravity at very large, horizon or super-horizon distances, can be tested by precision gravitational measurements at much shorter scales, such as the Earth-Moon distance. Contrary to the naive expectation the predicted corrections to the Einsteinian metric near gravitating sources are so significant that fall within sensitivity of the proposed Lunar Ranging experiments. The key reason for such corrections is the van Dam-Veltman-Zakharov discontinuity present in linearized versions of all such theories, and its subsequent absence at the non-linear level ala Vainshtein

Tree Nuts Anaphylaxis in Preschool Age Children

Summary: Introduction. The incidence of food-induced anaphylaxis (FIA) is increasing in young children. Although the commonest culprits are cow's milk and egg, FIA to tree nuts (TNs) have been increasing. Objective. Characterization of children referred to our allergy department due to TNs-induced anaphylaxis (TNs-FIA) during preschool age. Materials and methods. We have retrospectively included 25 children with clinical history of preschool TNs-FIA, proven by allergological work-up. TNs sensitization was assessed by skin prick tests and/or specific IgE. Results. The mean age of the first anaphylactic episode was 3.1±1.2 years. The majority (92%) had an allergic disease (52% asthma). The implicated TNs were cashew (11 children), walnut (8), pine nut (5), hazelnut (2) and almond (1). The reaction occurred after the first known ingestion in 68%. In 92%, symptoms appeared within 30 minutes after exposure. The most frequent clinical symptoms were mucocutaneous (96%), respiratory (80%) and gastrointestinal (52%). Twenty-one children were admitted to the emergency department, although only 48% were treated with epinephrine. An underneath IgE-mediated mechanism was proven in all cases. Immunologic cross-reactivity with other TNs was identified in 84%, and with peanut in 36%. Overall, in our center, TNs-FIA represents 18% of all causes of FIA. Conclusions. In preschool age children with TNs-FIA, cashew and walnut were the commonest implicated nuts. Most reactions occurred briefly after exposure to minimal amounts of TNs, demonstrating the high potency of these allergens. About one-third also had peanut sensitization. Potentially life-threatening TNs allergy can occur early in childhood and adequate management should be undertaken.publishersversionpublishe

Crescimento inicial de mudas de Aspidosperma pyrifolium irrigadas com água com diferentes níveis de salinidade.

O objetivo do trabalho foi avaliar o efeito da salinidade no crescimento inicial de mudas de Aspidosperma pyrifolium.Edição dos Resumos do V Workshop de Tecnologia e Fisiologia de Sementes e Mudas, Petrolina, dez. 2014

The b→sγγb\to s\gamma\gamma transition in softly broken supersymmetry

We study the effect of supersymmetric contributions to the effective quark transition $b\to s\gamma\gamma$, including leading order QCD effects. We apply the discussion to the decay $B_s\to\gamma\gamma$. Even though one-particle irreducible contributions could play a role, numerical cancelations make the amplitude for the two-photon emission strongly correlated to the $b\to s\gamma$ amplitude which is sharply constrained by experiment. A quite general statement follows: as long as non-standard physics effects appear only in the matching of the Wilson coefficients of the standard effective operator basis, the deviations from the standard model expectations of the decay rates induced by $b\to s\gamma\gamma$ are bound to follow closely the corresponding deviations on $b\to s\gamma$. Effects of new physics are therefore bound to be small.Comment: Latex2e, RevTex, 22 pages, 8 eps figures, comments and references adde

Classic Bioelectrical Impedance Vector Reference Values for Assessing Body Composition in Male and Female Athletes

Bioimpedance standards are well established for the normal healthy population and in clinical settings, but they are not available for many sports categories. The aim of this study was to develop reference values for male and female athletes using classic bioimpedance vector analysis (BIVA). In this study, 1556 athletes engaged in different sports were evaluated during their off-season period. A tetrapolar bioelectrical impedance analyzer was used to determine measurements of resistance (R) and reactance (Xc). The classic BIVA procedure, which corrects bioelectrical values for body height, was applied, and fat-free mass, fat mass, and total body water were estimated. In order to verify the need for specific references, classic bioelectrical values were compared to the reference values for the general male and female populations. Additionally, athletes were divided into three groups: endurance, velocity/power, and team sports. In comparison with the general healthy male and female populations, the mean vectors of the athletes showed a shift to the left on the R-Xc graph. Considering the same set of modalities, BIVA confidence graphs showed that male and female endurance athletes presented lower body fluids, fat mass, and fat-free mass than other sets of modalities. This study provides BIVA reference values for an athletic population that can be used as a standard for assessing body composition in male and female athletes