Simultaneous adsorption of Pb(Ii)-Cd(Ii), Pb(Ii)-phenol, and Cd(Ii)-phenol by activated carbon cloth in aqueous solution

"The aim of the present work was to determine the effect of the simultaneous adsorption of lead(II)-cadmium(II), lead(II)-phenol, and cadmium(II)-phenol by activated carbon cloths (ACCs). Three commercial ACCs were characterized and tested for individual metal adsorption, and competitive adsorption experiments were carried out with the best ACC (AW1104). The specific surface areas of all ACCs were >1000 m2/g, yet only AW1104 presented a high content of acidic sites (1.0 meq/g). Competitive adsorption experiments indicate that cadmium uptake is strongly affected by the presence of lead. This can be attributed either to a more favorable hydroxyl complexation of Pb(II) (that adsorbs strongly),or to the smallest hydrated radius of the Pb(II) molecule (that more easily diffuses). On the contrary, lead uptake was not considerably decreased in the presence of an equimolar cadmium concentration, indicating that AW1104 is more selective for Pb(II) than for Cd(II). Also, the presence of phenol causes a decrease in the heavy metal adsorption capacity, especially for cadmium (40 %). The former might be due to adsorbed phenol, which creates steric hindrance for cations to adsorb on specific oxygenated groups on the ACC. On the other hand, when heavy metals adsorb on the ACC surface, they stabilize the repulsive forces on the surface of the ACC for phenol adsorption, resulting in an increase of the adsorption capacity.

Chitosan selectivity for removing cadmium (II), copper (II), and lead (II) from aqueous phase: pH and organic matter effect

"The aim of this study was to investigate the selectivity of chitosan for cadmium, copper and lead in the presence and absence of natural organic matter (NOM) in different pH solutions. Adsorption isotherms of one and three adsorbates at initial concentration of 5–100 mg/L were carried out in batch reactors at pH 4, 5, or 7 and 25 °C in reactive and clarified water. The chitosan employed had a MW of 107.8 × 103 g/mol and degree of acetylation (DA) of 33.7%. The chitosan adsorption capacity at pH 4 in reactive water was 0.036, 0.016, 0.010 mmol/g for Pb2+, Cd2+, and Cu2+, respectively, and it decreased for Pb2+ and Cd2+ in clarified water. Conversely, experiments carried out in clarified water showed that the cadmium adsorption capacity of chitosan was enhanced about three times by the presence of NOM at pH 7: an adsorption mechanism was proposed. Furthermore, it was found that the biosorbent selectivity, in both reactive and clarified water at pH 4, was as follows Cu2+ > Cd2+ > Pb2+. Finally, the preliminary desorption experiments of Cd2+ conducted at pH 2 and 3 reported 68 and 44.8% of metal desorbed, which indicated that the adsorption mechanism occurred by electrostatic interactions and covalent bonds.

Capacidad de dos especies vegetativas en la acumulación de metales pesados

Habitat fragmentation allows for vegetative species to be used as indicators of environmental pollution by heavy metals. Considering the distribution of Prosopis laevigata (mesquite) and Schinus molle (pepper tree) heavy metal concentrations were determined as potential indicators of environmental impact assessment for agricultural and livestock, rural settlement, commercial and service, urban settlement and mining land uses. A total of 30 sampling points were established during summer, autumn, winter and spring, based on the presence of the two species. Applying the technique of ICP-MS, concentrations of Al, As, Co, Cu, Cd, Pb, Ti, V and Zn were determined. With a statistic model the interactions between species, type of land use and season with respect to the concentration of these minerals in the leaf material were determined. Results indicated that the presence of heavy metals is determined by the effect of the species, land use and season, and the possible association between these. The specie of mesquite was the most efficient for bioaccumulation of Pb, Co and Al. In the same way, the pepper tree was more efficient with respect to Ti. On one hand, trees located in the mining land use showed the highest concentrations of Cu, Zn, Cd, Pb, Co and As. On the other hand, the spring season presented the highest concentration of Cu, Zn, Co, Ti and V. With that, it could be demonstrated that As, Co, Cd, Pb, Ti and Zn concentrations were above the normal limit. Therefore, the dynamics and functionality, environmental factors and physiological differences to develop physicalchemical processes in the absorption and transport of these elements towards the leaves are a determining factor of vegetative species placed under conditions of fragmentation, are good elements for surveying on pollution and environmental impact.La fragmentación del hábitat permite aprovechar especies vegetativas como indicadoras de contaminación ambiental por metales pesados. Considerando la distribución de Prosopis laevigata (mezquite) y Schinus molle (pirul) se determinaron las concentraciones de metales pesados en material foliar para evaluar el impacto ambiental de los usos de suelo agropecuario, residencial rural, comercial y servicio, residencial urbano y minero. Fueron establecidos 30 puntos de muestro durante las estaciones de verano, otoño, invierno y primavera, basados en la presencia de las dos especies. Aplicando la Técnica ICP-MS fueron determinadas las concentraciones de Al, As, Co, Cu, Cd, Pb, Ti, V y Zn. Con un ANOVA se probaron las interacciones entre especie, tipo de uso de suelo y estación con respecto a la concentración de estos minerales en material foliar. Los resultados indicaron que la presencia de metales pesados está condicionada por el efecto de la especie, uso de suelo y la estación, así como la posible asociación entre estos. El mezquite resultó ser más eficiente en la bioacumulación de Pb, Co y Al. En el caso del pirul solo fue más eficiente con respecto al Ti. Los árboles ubicados en el uso de suelo minero obtuvieron las mayores concentraciones de Cu, Zn, Cd, Pb, Co y As. Por otra parte, la estación de primavera incidió en la mayor concentración de Cu, Co, Ti y V. Con esto se pudo demostrar que As, Co, Cd, Pb Ti y Zn presentaron concentraciones arriba del límite normal en material foliar. Por lo tanto, la dinámica y funcionalidad, factores ambientales y diferencias fisiológicas para desarrollar procesos físico-químicos en la absorción y transporte de estos elementos hacia las hojas son un factor determinante de las especies vegetativas situadas bajo condición de fragmentación, lo que contribuye ser un buen elemento de estudio de la contaminación y evaluación del impacto ambiental.Fil: Alcalá Jáuregui, Jorge. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Rodríguez Ortíz, Juan C.. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Hernández Montoya, Alejandra. Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Filippini, María Flavia. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Martínez Carretero, Eduardo. Instituto Argentino de Investigaciones de las Zonas Áridas Fil: Diaz Flores, Paola Elizabeth. Universidad Autónoma de San Luis Potosí. Facultad de Agronomí

Cortezas de Prosopis laevigata (Fabaceae) y Schinus molle (Anacardiaceae) como bioindicadoras de contaminación por metales pesados

The tree bark is a valuable component to diagnose heavy metal air pollution. In bark of P. laevigata and S. molle presence of eleven heavy metals was evaluated, as indicator of environmental impact in San Luis Potosí, México. Based on the presence of both species on a soil system fragmented agricultural uses, rural settlements, trade and services, urban settlements and mineral uses, bark samples were taken during summer, autumn, winter and spring seasons. In each species thirty exemplars were sampled. Concentrations of Al, As, Co, Cu, Cd, Cr, Ni, Pb, Ti, V and Zn were determined by applying the ICP-MS technique, and for data analysis the General lineal model was applied. Results indicated that the average concentrations vary according to Ni> Al> Zn> Pb > Cu> As> Ti> V> Cd> Cr> Co. The presence of heavy metals was determined by the species effect, land use and season, and the relationship between these factors. The pepper tree bark was found to have higher concentrations of Al, As, Co, Cd, Cr, Ni, Pb and Ti. The highest concentrations of Al, Cu, Cr, Co and Ni were in the fall season. The urban settlement showed higher concentrations of Al, Co, Cr, Ni, Ti and V; meanwhile in the mining soil use Cu, Cd, Zn and Pb were relevant. The potential bio-indicator value of bark of both species was evidenced. Consequently, it is convenient to continue with these studies to increase knowledge of the environmental conditions of the San Luis Potosí.La corteza arbórea constituye un elemento viable para diagnosticar la contaminación por metales pesados. Fue evaluada la presencia de once metales pesados en corteza de P. laevigata "mezquite" y S. molle "pirul" como indicador de impacto ambiental en San Luis Potosí, México. Basado en la presencia de estas dos especies sobre un sistema fragmentado por usos de suelo agropecuario, asentamiento rural, comercial y servicio, asentamiento urbano y minero, se tomó muestras de corteza durante las estaciones de verano, otoño, invierno y primavera. Se aplicó la técnica ICP-MS y se determinó las concentraciones de Al, As, Co, Cu, Cd, Cr, Ni, Pb, Ti, V y Zn, diseñando un modelo General Lineal para su análisis. Los resultados indicaron concentraciones promedio de Ni>Al>Z n>Pb>Cu>As>Ti>V>Cd>Cr>Co. La presencia de metales pesados fue condicionada por el efecto de la especie, uso de suelo y la temporada, así como la relación entre estos factores. Las cortezas de S. molle resultaron tener mayores concentraciones de Al, As, Co, Cd, Cr, Ni, Pb y Ti. En otoño se presentaron las mayores concentraciones de Al, Cu, Cr, Co y Ni. El uso de suelo para asentamiento urbano presentó las mayores concentraciones de Al,Co, Cr, Ni, Ti y V y el uso de suelo minero las de Cu, Cd, Zn y Pb. Se demuestra el potencial bioindicador de la corteza de ambas especies. Se sugiere continuar realizando estudios que permitan ampliar el conocimiento de las condiciones ambientales de la zona

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

Peer reviewe

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection