Feasibility of using low-cost, byproduct materials as sorbents to remove heavy metals from aqueous solutions

This work investigates the sorption of heavy metals by low-cost, byproducts such as charcoal fines (CF), waste green sand, and rice husk ash, in order to examine the feasibility of their use as alternative filter materials for metal-contaminated waters. The sorption of Cd, Cu, Pb, and Zn was investigated in batch experiments and sorption isotherms were constructed. The three byproducts showed high metal removal efficiencies (>95%, regardless of the metal concentration tested). The highest metal sorption distribution coefficients were obtained for CF, with maximum values within the 105-106 L kg-1 range for all the target metals. The sorption isotherms were satisfactorily fitted using the Freundlich equation and a linear model, the latter only being valid for initial metal concentrations lower than 0.4 mmol L-1. Sorption reversibility was very low, with desorption yields lower than 2% and desorption distribution coefficients often higher than 106 L kg-1. The values of the sorption and desorption parameters indicated that the use of these materials, especially CF, could constitute a low-cost alternative for the remediation of contaminated waters

Doença de Carrión (Bartonelose baciliforme) confirmada por histopatologia na Selva Alta do Peru

Bartonellosis or Carrion's disease is endemic in some regions of Peru, classically found in the inter-Andean valleys located between 500 and 3200 meters above sea level. We report the case of a 43 year-old male patient, farmer, who was born in the Pichanaki district (Chanchamayo, Junin), located in the High Forest of Peru. He presented with disseminated, raised, erythematous cutaneous lesions, some of which bled. The distribution of these lesions included the nasal mucosa and penile region. Additionally subcutaneous nodules were distributed over the trunk and extremities. Hematologic exams showed a moderate anemia. Serologic studies for HIV and Treponema pallidum were negative. The histopathologic results of two biopsies were compatible with Peruvian wart. Oral treatment with ciprofloxacin (500 mg BID) was begun. Over 10 days, the patient showed clinical improvement. This is the first report of a confirmed case of bartonellosis in the eruptive phase originating from the Peruvian High Forest, showing the geographical expansion of the Carrion's disease.A bartonelose ou doença de Carrión é endêmica em algumas regiões do Peru, descrevendo-se classicamente nos vales inter-andinos, entre 500 e 3.200 metros acima do nível do mar. Os autores relatam o caso de um paciente de 43 anos de idade, fazendeiro, natural do distrito de Pichanaki (Chanchamayo, Junín), localizado na Selva Alta do Peru. O paciente apresentou-se com lesões disseminadas, elevadas e eritematosas, algumas delas com sinais de sangramento. Distribuiam-se também na mucosa nasal e no penis. Foram também observados nódulos subcutâneos no tronco e nas extremidades. Os exames laboratorais evidenciaram anemia moderada. Os testes sorológicos para detectar anticorpos contra o HIV e Treponema pallidum foram negativos. Os resultados dos estudos histopatológicos de duas biópsias de pele foram compatíveis com verruga peruana. Iniciou-se antibioticoterapia com ciprofloxacina (500 mg duas vezes ao dia). Após dez dias de tratamento, o paciente apresentou melhora clínica importante. Este relato representa o primeiro caso autóctone confirmado da fase eruptiva da bartonelose em um paciente da Selva Alta do Peru, sugestiva da expansão geográfica da doença

Reversed-phase dispersive liquid–liquid microextraction for elemental analysis of gasoline by inductively coupled plasma optical emission spectrometry

In this work a green and fast sample preparation method based on reversed-phase dispersive liquid–liquid microextraction (RP-DLLME) was developed for the separation and preconcentration of several elements (i.e., Ag, As, Ba, Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, S, Se, Sn and V) in gasoline samples before determination by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The extraction procedure was carried out in a reverse mode, since a small volume of the aqueous phase (i.e., 8 M HCl) is used to extract a relatively high volume of the organic phase (i.e., gasoline sample). Unlike conventional DLLME, in RP-DLLME the analytes were extracted from the organic phase into the aqueous phase. The experimental conditions for the microextraction procedure were: 5 g of sample, 8 M HCl as the extractant phase, mechanical agitation by vortex as the dispersion system, 115 μL of extractant volume, and 2 min extraction and 5 min centrifugation time. Under optimized extraction conditions the enrichment factor ranged between 3 and 53, and the limits of detection ranged between 0.02 and 50 μg kg−1. The proposed analytical method was validated and successfully used to analyze three gasoline samples. All gasoline samples were spiked at 100 μg kg−1 for all analytes, except sulfur (in this case at 1000 μg kg−1), obtaining recovery and RSD values within the range of 88–109% and 2–9%, respectively.The authors would like to thank the Regional Government of Valencia (Spain) (PROMETEO/2018/087) for the financial support, Agilent Technologies Inc. for the loan of the ICP-OES spectrometer, and Ingeniatrics for the OneNeb® provided. Financial support from Universidad Nacional del Sur is gratefully acknowledged. A. S. Lorenzetti, E. Vidal and C. E. Domini wish to thank Consejo Nacional de Investigaciones Científicas y Técnicas for the financial support received. The authors extend their appreciation to the Ministry of Science, Innovation and Universities for granting the Spanish Network of Excellence in Sample Preparation (RED2018-102522-T). This article is based upon work from the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical Society

Visões ascendentes : fragmentos do olhar curitibano aos mais leves que o ar

Orientadora: Ana Maria de Oliveira BurmesterAutor não autorizou a divulgação do arquivo digitalDissertação (mestrado) - Universidade Federal do ParanaInclui referência

Perceived stress and high fat intake: A study in a sample of undergraduate students.

OBJECTIVES: Different studies have reported the association between perceived stress and unhealthy diet choices. We aimed to determine whether there is a relationship between perceived stress and fat intake among undergraduate medical students. METHODS/PRINCIPAL FINDINGS: A cross-sectional study was performed including first-year medical students. The outcome of interest was the self-report of fat intake assessed using the Block Screening Questionnaire for Fat Intake (high vs. low intake), whereas the exposure was perceived stress (low/normal vs. high levels). The prevalence of high fat intake was estimated and the association of interest was determined using prevalence ratios (PR) and 95% confidence intervals (95%CI). Models were created utilizing Poisson regression with robust standard errors. Data from 523 students were analyzed, 52.0% female, mean age 19.0 (SD 1.7) years. The prevalence of high fat intake was 42.4% (CI: 38.2%-46.7%). In multivariate model and compared with those with lowest levels of stress, those in the middle (PR = 1.59; 95%CI: 1.20-2.12) and highest (PR = 1.92; 95%CI: 1.46-2.53) categories of perceived stress had greater prevalence of fat intake. Gender was an effect modifier of this association (p = 0.008). CONCLUSIONS: Greater levels of perceived stress were associated with higher fat intake, and this association was stronger among males. More than 40% of students reported having high fat consumption. Our results suggest the need to implement strategies that promote decreased fat intake

Assessment of the spatial variability of soil chemical properties along a transect using multifractal analysis

[Abstract]The spatial variability of soil properties can be assessed through concepts of scale invariance, fractals and multifractals. The aim of this study was to characterize the scaling patterns and structural heterogeneity properties of general soil chemical properties along a short (i.e. 52 m large) transect. Field measurements were carried out at the experimental farm of CIAM located in Mabegondo, A Coruña, Spain. The studied transect was marked following land slope, and 66 soil samples were collected at the 0-20 cm depth every 0.8 m. The soil properties analyzed were: pH (H2O ), organic carbon content, exchangeable Ca, Mg and K, exchangeable acidity (H + Al), exchangeable bases (SB), cation exchange capacity (CEC), percent base saturation (V) and extractable P. The soil properties studied showed various degrees of multifractality. The spatial distribution of pH was characterized by quasi-monofractal behaviour; CEC, (H+Al) and OM, presented a relatively low degree of multifractality, and the other soil properties studied showed stronger degrees of multifractality, being the highest one for Olsen extractable P. In general, the scaling features of the properties studied implied a multifractal nature, where the low and high density regions scaled differently

Screen-printed electrode-based electrochemical detector coupled with in-situ ionic-liquid-assisted dispersive liquid–liquid microextraction for determination of 2,4,6-trinitrotoluene

A novel method is reported, whereby screen-printed electrodes (SPELs) are combined with dispersive liquid–liquid microextraction. In-situ ionic liquid (IL) formation was used as an extractant phase in the microextraction technique and proved to be a simple, fast and inexpensive analytical method. This approach uses miniaturized systems both in sample preparation and in the detection stage, helping to develop environmentally friendly analytical methods and portable devices to enable rapid and onsite measurement. The microextraction method is based on a simple metathesis reaction, in which a water-immiscible IL (1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide, [Hmim][NTf2]) is formed from a water-miscible IL (1-hexyl-3-methylimidazolium chloride, [Hmim][Cl]) and an ion-exchange reagent (lithium bis[(trifluoromethyl)sulfonyl]imide, LiNTf2) in sample solutions. The explosive 2,4,6-trinitrotoluene (TNT) was used as a model analyte to develop the method. The electrochemical behavior of TNT in [Hmim][NTf2] has been studied in SPELs. The extraction method was first optimized by use of a two-step multivariate optimization strategy, using Plackett–Burman and central composite designs. The method was then evaluated under optimum conditions and a good level of linearity was obtained, with a correlation coefficient of 0.9990. Limits of detection and quantification were 7 μg L−1 and 9 μg L−1, respectively. The repeatability of the proposed method was evaluated at two different spiking levels (20 and 50 μg L−1), and coefficients of variation of 7 % and 5 % (n = 5) were obtained. Tap water and industrial wastewater were selected as real-world water samples to assess the applicability of the method.The authors would like to thank the Spanish Ministry of Science and Innovation (project n. CTQ2011-23968), Generalitat Valenciana (Spain) (projects n. ACOMP/2013/072 and PROMETEO/2012/038) and Universidad de Alicante (Spain) (project n. GRE12-45) for the financial support. E.F. also thanks Generalitat Valenciana for her fellowship

Optical constants of evaporation-deposited silicon monoxide films in the 7.1-800 eV photon energy range

8 págs.; 11 figs.The transmittance of silicon monoxide films prepared by thermal evaporation was measured from 7.1 to 800 eV and used to determine the optical constants of the material. SiO films deposited onto C-coated microgrids in ultrahigh vacuum conditions were measured in situ from 7.1 to 23.1 eV. Grid-supported SiO films deposited in high vacuum conditions were characterized ex situ from 28.5 to 800 eV. At each photon energy, transmittance, and thickness data were used to calculate the extinction coefficient k. The obtained k values combined with data from the literature, and with interpolations and extrapolations in the rest of the electromagnetic spectrum provided a complete set of k values that was used in a Kramers-Kronig analysis to obtain the real part of the index of refraction, n. Two different sum-rule tests were performed that indicated good consistency of the data. © 2009 American Institute of Physics.This work was supported by the National Programme for Space Research, Subdirección General de Proyectos de Investigación, Ministerio de Ciencia y Tecnología, Project Nos. ESP2002-01391 and ESP2005-02650. This work was also performed under the auspices of the U.S. Department of Energy by the University of California Lawrence Berkeley National Laboratory under Contract No. DE-AC03-76F00098 and by the University of California Lawrence Livermore National Laboratory under Contract No. DE-AC52- 07NA27344. M.F.-P. is thankful to Consejo Superior de Investigaciones Científicas Spain for funding under the Programa I3P Contract No. I3P-BPD2004, partially supported by the European Social Fund. M.V.-D. acknowledges financial support from a FPI Contract No. BES-2006-14047 fellowship.Peer Reviewe

Journals’ policies of storage and reuse of raw research data and their impact in five scientific areas

Analisys of journals' policies about storage and re-use of raw research data

Entanglement Percolation in Quantum Networks

Quantum networks are composed of nodes which can send and receive quantum states by exchanging photons. Their goal is to facilitate quantum communication between any nodes, something which can be used to send secret messages in a secure way, and to communicate more efficiently than in classical networks. These goals can be achieved, for instance, via teleportation. Here we show that the design of efficient quantum communication protocols in quantum networks involves intriguing quantum phenomena, depending both on the way the nodes are displayed, and the entanglement between them. These phenomena can be employed to design protocols which overcome the exponential decrease of signals with the number of nodes. We relate the problem of establishing maximally entangled states between nodes to classical percolation in statistical mechanics, and demonstrate that quantum phase transitions can be used to optimize the operation of quantum networks.Comment: Accepted for publication in Nature Physics. This is the original submitted versio