1,361 research outputs found
Middle Phase Electrochemistry of Two Pentacyano(L)Ferrates(II)
The electrochemical behaviour of two water soluble redox species (pentacyano(L)ferrate(II)
complexes, where L is 4,4\u27-bipyridine and ammonia), belonging to cyanoferrate(II) series, was investigated
by using cyclic voltammetry (CV) technique in a "middle phase microemulsion" (MPME). The
microemulsion (ME) is formed between water and toluene, by using, besides the redox species, sodium
dodecyl sulphate as surfactant, 1-butanol as cosurfactant and sodium chloride as supporting electrolyte.
Three different three-electrode configuration arrangements were used. In each case reversible behaviour
for both species was obtained. Different behaviour was found in "middle phase" for the two investigated
electroactive species based on the presence of the sixth ligand (coligand). The coligand determines, on one
hand, different electronic influence on the electron transfer reaction at Pt working electrode and, on the
other hand, specific interaction with the "microscopic organic phase" from "middle phase". This paper
demonstrates, based on Randles-Sevcik equation, that [Fe(CN)5(4,4\u27âbpy)]3â is distributed between the
"water phase" and "microscopic aqueous phase" rather in latter phase. For [Fe(CN)5(NH3)]3â, its distribution
is similar with that of the common hexacyanoferrate(III) or hexacyanoferrate(II). The CV study of the
two different electroactive species illustrates an almost reversible behaviour both in "middle phase" and
"water phase". (doi: 10.5562/cca1999
Synthesis and Functionalization of Nanoparticles in Supercritical CO<sub>2</sub>
A review of recent results on fabrication of inorganic and organic nanoparticles in supercritical carbon dioxide will be presented, with particular emphasis on the metallic and polymeric nanoparticles used in biomedicine. The use of the water-in-scCO2 microemulsion in the synthesis of metal nanoparticles will be also discussed. The recent progress in preparation of polymeric nanoparticles with desired size and porosity obtained through processing methods in scCO2 as drug delivery systems will be described. The efficiency of the drug encapsulation in organic and inorganic nanoparticles using supercritical CO2 as dissolving media is another topic of interest. Various methods to achieve surface functionalization of nanoparticles in supercritical and subcritical CO2 will be evaluated, considering the challenges and limitations in efficiency, scalability, and development of new applications
Product distributions from fast pyrolysis of 10 Ecuadorian agricultural residual biomass samples
Noble Metal Dispersed on Reduced Graphene Oxide and Its Application in PEM Fuel Cells
Metal-dispersed nanoparticles on reduced graphene oxide as catalyst for oxygen reduction reaction (ORR) demonstrate promising applications in the energy sector. The catalyst activity enhancement and stability improvement investigated in this study are mandatory steps in obtaining feasible electrodes for PEMFC. The chapter deals with the synthesis of noble metal catalysts including platinum and gold nanoparticles dispersed on reduced graphene oxide (PtNPs/rGO and AuNPs/rGrO). The understanding of the correlations between the electrochemical activity on one side and the structure, composition and synthesis method on the other side are provided. Facile routes in order to prepare the well dispersed PtNPs/rGO and AuNPs/rGrO are included. The structure and morphology were characterized by different techniques, namely X-ray diffraction (XRD), Scanning Transmission Electron Microscopy (STEM), specific surface area measurements. In this context we report a hybrid derived electrocatalyst with increased electrochemical active area and enhanced mass-transport properties. The electrochemical performances of PtNPs/rGO and AuNPs/rGrO were tested and compared with a standard PEMFC configuration. The performed electrochemical characterization recommends the prepared materials as ORR electrocatalysts for the further fabrication of cathodes for PEM fuel cells. The research directions as well as perspectives on the subsequent development of more active and less expensive electrocatalysts are established
Misdiagnosis and uncritical use of plant mycorrhizal data are not the only elephants in the room
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
WSES/GAIS/WSIS/SIS-E/AAST global clinical pathways for patients with skin and soft tissue infections
Skin and soft-tissue infections (SSTIs) encompass a variety of pathological conditions that involve the skin and underlying subcutaneous tissue, fascia, or muscle, ranging from simple superficial infections to severe necrotizing infections. Together, the World Society of Emergency Surgery, the Global Alliance for Infections in Surgery, the Surgical Infection Society-Europe, The World Surgical Infection Society, and the American Association for the Surgery of Trauma have jointly completed an international multi-society document to promote global standards of care in SSTIs guiding clinicians by describing reasonable approaches to the management of SSTIs. An extensive non-systematic review was conducted using the PubMed and MEDLINE databases, limited to the English language. The resulting evidence was shared by an international task force with different clinical backgrounds.Peer reviewe
WSES/GAIS/SIS-E/WSIS/AAST global clinical pathways for patients with intra-abdominal infections
Intra-abdominal infections (IAIs) are common surgical emergencies and have been reported as major contributors to non-trauma deaths in hospitals worldwide. The cornerstones of effective treatment of IAIs include early recognition, adequate source control, appropriate antimicrobial therapy, and prompt physiologic stabilization using a critical care environment, combined with an optimal surgical approach. Together, the World Society of Emergency Surgery (WSES), the Global Alliance for Infections in Surgery (GAIS), the Surgical Infection Society-Europe (SIS-E), the World Surgical Infection Society (WSIS), and the American Association for the Surgery of Trauma (AAST) have jointly completed an international multi-society document in order to facilitate clinical management of patients with IAIs worldwide building evidence-based clinical pathways for the most common IAIs. An extensive non-systematic review was conducted using the PubMed and MEDLINE databases, limited to the English language. The resulting information was shared by an international task force from 46 countries with different clinical backgrounds. The aim of the document is to promote global standards of care in IAIs providing guidance to clinicians by describing reasonable approaches to the management of IAIs.Peer reviewe
Improved imputation of low-frequency and rare variants using the UK10K haplotype reference panel
Imputing genotypes from reference panels created by whole-genome sequencing (WGS) provides a cost-effective strategy for augmenting the single-nucleotide polymorphism (SNP) content of genome-wide arrays. The UK10K Cohorts project has generated a data set of 3,781 whole genomes sequenced at low depth (average 7x), aiming to exhaustively characterize genetic variation down to 0.1% minor allele frequency in the British population. Here we demonstrate the value of this resource for improving imputation accuracy at rare and low-frequency variants in both a UK and an Italian population. We show that large increases in imputation accuracy can be achieved by re-phasing WGS reference panels after initial genotype calling. We also present a method for combining WGS panels to improve variant coverage and downstream imputation accuracy, which we illustrate by integrating 7,562 WGS haplotypes from the UK10K project with 2,184 haplotypes from the 1000 Genomes Project. Finally, we introduce a novel approximation that maintains speed without sacrificing imputation accuracy for rare variants
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