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

Nonlinear Polariton Fluids in a Flatband Reveal Discrete Gap Solitons

Phase frustration in periodic lattices is responsible for the formation of dispersionless flat bands. The absence of any kinetic energy scale makes flat band physics critically sensitive to perturbations and interactions. We report here on the experimental investigation of the nonlinear dynamics of cavity polaritons in the gapped flat band of a one-dimensional Lieb lattice. We observe the formation of gap solitons with quantized size and very abrupt edges, signature of the frozen propagation of switching fronts. This type of gap solitons belongs to the class of truncated Bloch waves, and had only been observed in closed systems up to now. Here the driven-dissipative character of the system gives rise to a complex multistability of the nonlinear domains generated in the flat band. These results open up interesting perspective regarding more complex 2D lattices and the generation of correlated photon phases.Comment: 6 pages, 4 figures + supplemental material (6 pages, 6 figures

Transcribed ultraconserved noncoding RNAs (T-UCR) are involved in Barrett's esophagus carcinogenesis.

Barretts esophagus (BE) involves a metaplastic replacement of native esophageal squamous epithelium (Sq) by columnar-intestinalized mucosa, and it is the main risk factor for Barrett-related adenocarcinoma (BAc). Ultra-conserved regions (UCRs) are a class non-coding sequences that are conserved in humans, mice and rats. More than 90% of UCRs are transcribed (T-UCRs) in normal tissues, and are altered at transcriptional level in tumorigenesis. To identify the T-UCR profiles that are dysregulated in Barretts mucosa transformation, microarray analysis was performed on a discovery set of 51 macro-dissected samples obtained from 14 long-segment BE patients. Results were validated in an independent series of esophageal biopsy/surgery specimens and in two murine models of Barretts esophagus (i.e. esophagogastric-duodenal anastomosis). Progression from normal to BE to adenocarcinoma was each associated with specific and mutually exclusive T-UCR signatures that included up-regulation of uc.58-, uc.202-, uc.207-, and uc.223- and down-regulation of uc.214+. A 9 T-UCR signature characterized BE versus Sq (with the down-regulation of uc.161-, uc.165-, and uc.327-, and the up-regulation of uc.153-, uc.158-, uc.206-, uc.274-, uc.472-, and uc.473-). Analogous BE-specific T-UCR profiles were shared by human and murine lesions. This study is the first demonstration of a role for T-UCRs in the transformation of Barretts mucosa

Quantificação dos teores de açúcares, oligossacarídeos e amido em genótipos/ cultivares de soja (Glycine Max (L) Merril) especiais utilizados para alimentação humana.

RESUMO: Na soja, vários componentes, tais como açúcares, aminoácidos, ácidos orgânicos, sais inorgânicos, isoflavonas e saponinas estão relacionados com o sabor. Os açúcares, a sacarose e o amido, podem melhorar o sabor e a textura da soja. O objetivo deste trabalho foi quantificar os teores desses compostos e dos oligossacarídeos, em sementes de 28 genótipos/cultivares do Banco Ativo de Germoplasma da Embrapa Soja, que apresentam características especiais para o melhoramento genético. Os açúcares e os oligossacarídeos foram quantificados pela técnica de cromatografia liquida de alto desempenho (CLAE) e o amido pela metodologia adaptada de Rickard e Behn (1987). Os genótipos PI 417.159 e F83-8119 apresentaram menores teores de oligossacarídeos totais (2,744 e 3,064 g.100 g de massa seca). As cultivares Tambaguro e Koji Amarela foram as que apresentaram teores de sacarose superiores a 6 g.100 g–1 de massa seca(6,327 e 6,162), enquanto que a única cultivar que apresentou um teor superior a 1 g.100g–1–1 de massa seca de amido foi a Tambaguro (1,191). As cultivares Koji Preta, Tamahomare, Tambaguro e BRS 267 foram estatisticamente superiores quando os 3 atributos (oligossacarídeos totais, sacarose e amido) foram avaliados conjuntamente, com o foco em sabor superior. As cultivares Koji Preta, Tamahomare, Tambaguro foram as melhores fontes genéticas indicadas para cruzamentos, pois não são tropicalizadas, enquanto a cultivar BRS 267 pode melhorar as qualidades sensoriais dos produtos processados a partir de soja. Por outro lado, a cultivar Late Giant, devido ao maior teor de oligossacarídeos, é uma fonte genética em potencial para produção de um alimento funcional à base de soja. ABSTRACT: In soybeans, many components such as sugars, amino acids, organic acids, inorganic salts, saponins and isoflavones are related to the flavour. The sugars, sucrose and starch can improve the soybean flavour and texture. The present study aimed to quantify the contents of these compounds and also the oligosaccharides in the seeds from 28 genotypes/cultivars obtained from the Embrapa Soybean Germplasm Bank, that present special characteristics for genetic improvement programmes. The sugars and oligosaccharides were quantified by high-performance liquid chromatography (HPLC) and the starch by methodology adapted from Rickard e Behn (1987). The genotypes PI 417.159 and F83-8119 showed the lowest contents of total oligosaccharides (2.744 and 3.064 g.100 g DW). The cultivars Tambaguro and Koji Amarela showed sucrose levels above 6 g.100 g–1 DW (6.327 and 6.162), and the only cultivar with a starch content above 1 g.100 g–1 DW was Tambaguro (1.191). The cultivars Koji Preta, Tamahomare, Tambaguro and BRS 267 were statistically better when the 3 attributes (total oligosaccharides, sucrose and starch) were analysed together with a focus on better flavour. The cultivars Koji Preta, Tamahomare, Tambaguro were the best genetic sources for breeding because they have not been tropicalized, whilst the cultivar BRS 267 could improve the sensory qualities of processed soybean-based foods. On the other hand, on account of its higher oligosaccharide content, the cultivar Late Giant is a potential genetic source for the production of functional soybean-based foods

Asymmetric Fluid Criticality I: Scaling with Pressure Mixing

The thermodynamic behavior of a fluid near a vapor-liquid and, hence, asymmetric critical point is discussed within a general ``complete'' scaling theory incorporating pressure mixing in the nonlinear scaling fields as well as corrections to scaling. This theory allows for a Yang-Yang anomaly in which \mu_{\sigma}^{\prime\prime}(T), the second temperature derivative of the chemical potential along the phase boundary, diverges like the specific heat when T\to T_{\scriptsize c}; it also generates a leading singular term, |t|^{2\beta}, in the coexistence curve diameter, where t\equiv (T-T_{\scriptsize c}) /T_{\scriptsize c}. The behavior of various special loci, such as the critical isochore, the critical isotherm, the k-inflection loci, on which \chi^{(k)}\equiv \chi(\rho,T)/\rho^{k} (with \chi = \rho^{2} k_{\scriptsize B}TK_{T}) and C_{V}^{(k)}\equiv C_{V}(\rho,T)/\rho^{k} are maximal at fixed T, is carefully elucidated. These results are useful for analyzing simulations and experiments, since particular, nonuniversal values of k specify loci that approach the critical density most rapidly and reflect the pressure-mixing coefficient. Concrete illustrations are presented for the hard-core square-well fluid and for the restricted primitive model electrolyte. For comparison, a discussion of the classical (or Landau) theory is presented briefly and various interesting loci are determined explicitly and illustrated quantitatively for a van der Waals fluid.Comment: 21 pages in two-column format including 8 figure

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

NetKet: A machine learning toolkit for many-body quantum systems

We introduce NetKet, a comprehensive open source framework for the study of many-body quantum systems using machine learning techniques. The framework is built around a general and flexible implementation of neural-network quantum states, which are used as a variational ansatz for quantum wavefunctions. NetKet provides algorithms for several key tasks in quantum many-body physics and quantum technology, namely quantum state tomography, supervised learning from wavefunction data, and ground state searches for a wide range of customizable lattice models. Our aim is to provide a common platform for open research and to stimulate the collaborative development of computational methods at the interface of machine learning and many-body physics

Preprint arXiv: 2204.03454 Submitted on 7 Apr 2022

We propose a variational quantum algorithm to study the real time dynamics of quantum systems as a ground-state problem. The method is based on the original proposal of Feynman and Kitaev to encode time into a register of auxiliary qubits. We prepare the Feynman-Kitaev Hamiltonian acting on the composed system as a qubit operator and find an approximate ground state using the Variational Quantum Eigensolver. We apply the algorithm to the study of the dynamics of a transverse field Ising chain with an increasing number of spins and time steps, proving a favorable scaling in terms of the number of two qubit gates. Through numerical experiments, we investigate its robustness against noise, showing that the method can be use to evaluate dynamical properties of quantum systems and detect the presence of dynamical quantum phase transitions by measuring Loschmidt echoes

Liquid-gas phase transition in nuclear multifragmentation

The equation of state of nuclear matter suggests that at suitable beam energies the disassembling hot system formed in heavy ion collisions will pass through a liquid-gas coexistence region. Searching for the signatures of the phase transition has been a very important focal point of experimental endeavours in heavy ion collisions, in the last fifteen years. Simultaneously theoretical models have been developed to provide information about the equation of state and reaction mechanisms consistent with the experimental observables. This article is a review of this endeavour.Comment: 63 pages, 27 figures, submitted to Adv. Nucl. Phys. Some typos corrected, minor text change