A Class of N-O-Type Oxidants to Access High-Valent Palladium Species

This article presents a new class of mild reagents that is capable of oxidizing palladacycle(II) complexes to high-valent palladium species, promoting the formation of C–N bonds in stoichiometric and catalytic conditions. The weak N–O bond and the extremely electron with-drawing benzenesulfonate group on the oxygen atom of the oxidant are crucial moieties to ensure the desired activity. The oxidation mech-anism could involve outer-sphere single electron transfer (SET) processes, opening the possibility for a complementary reactivity of Pd(IV) species.Royal Society H2020 European Research Counci

Genetic characterization of human coxsackievirus A6 variants associated with atypical hand, foot and mouth disease: a potential role of recombination in emergence and pathogenicity

Human coxsackievirus A6 (CVA6) is an enterically transmitted enterovirus. Until recently, CVA6 infections were considered as being of minor clinical significance, and only rarely aetiologically linked with hand, foot and mouth disease (HFMD) associated with other species A enteroviruses (particularly EV71 and CVA16). From 2008 onwards, however, CVA6 infections have been associated with several outbreaks worldwide of atypical HFMD (aHFMD) accompanied by a varicelliform rash. We recently reported CVA6-associated eczema herpeticum occurring predominantly in children and young adults in Edinburgh in January and February 2014. To investigate genetic determinants of novel clinical phenotypes of CVA6, we genetically characterized and analysed CVA6 variants associated with eczema herpeticum in Edinburgh in 2014 and those with aHFMD in CAV isolates collected from 2008. A total of eight recombinant forms (RFs) have circulated worldwide over the past 10 years, with the particularly recent appearance of RF-H associated with eczema herpeticum cases in Edinburgh in 2014. Comparison of phylogenies and divergence of complete genome sequences of CVA6 identified recombination breakpoints in 2A-2C, within VP3, and between 5' untranslated region and VP1. A Bayesian temporal reconstruction of CVA6 evolution since 2004 provided estimates of dates and the actual recombination events that generated more recently appearing recombination groups (RF-E, -F, -G and -H). Associations were observed between recombination groups and clinical presentations of herpangina, aHFMD and eczema herpeticum, but not with VP1 or other structural genes. These observations provided evidence that NS gene regions may potentially contribute to clinical phenotypes and outcomes of CVA6 infection

Universal Formulae for Percolation Thresholds

A power law is postulated for both site and bond percolation thresholds. The formula writes $p_c=p_0[(d-1)(q-1)]^{-a}d^{\ b}$, where $d$ is the space dimension and $q$ the coordination number. All thresholds up to $d\rightarrow \infty$ are found to belong to only three universality classes. For first two classes $b=0$ for site dilution while $b=a$ for bond dilution. The last one associated to high dimensions is characterized by $b=2a-1$ for both sites and bonds. Classes are defined by a set of value for $\{p_0; \ a\}$. Deviations from available numerical estimates at $d \leq 7$ are within $\pm 0.008$ and $\pm 0.0004$ for high dimensional hypercubic expansions at $d \geq 8$. The formula is found to be also valid for Ising critical temperatures.Comment: 11 pages, latex, 3 figures not include

Recent, independent and anthropogenic origins of Trypanosoma cruzi hybrids.

The single celled eukaryote Trypanosoma cruzi, a parasite transmitted by numerous species of triatomine bug in the Americas, causes Chagas disease in humans. T. cruzi generally reproduces asexually and appears to have a clonal population structure. However, two of the six major circulating genetic lineages, TcV and TcVI, are TcII-TcIII inter-lineage hybrids that are frequently isolated from humans in regions where chronic Chagas disease is particularly severe. Nevertheless, a prevalent view is that hybridisation events in T. cruzi were evolutionarily ancient and that active recombination is of little epidemiological importance. We analysed genotypes of hybrid and non-hybrid T. cruzi strains for markers representing three distinct evolutionary rates: nuclear GPI sequences (n = 88), mitochondrial COII-ND1 sequences (n = 107) and 28 polymorphic microsatellite loci (n = 35). Using Maximum Likelihood and Bayesian phylogenetic approaches we dated key evolutionary events in the T. cruzi clade including the emergence of hybrid lineages TcV and TcVI, which we estimated to have occurred within the last 60,000 years. We also found evidence for recent genetic exchange between TcIII and TcIV and between TcI and TcIV. These findings show that evolution of novel recombinants remains a potential epidemiological risk. The clearly distinguishable microsatellite genotypes of TcV and TcVI were highly heterozygous and displayed minimal intra-lineage diversity indicative of even earlier origins than sequence-based estimates. Natural hybrid genotypes resembled typical meiotic F1 progeny, however, evidence for mitochondrial introgression, absence of haploid forms and previous experimental crosses indicate that sexual reproduction in T. cruzi may involve alternatives to canonical meiosis. Overall, the data support two independent hybridisation events between TcII and TcIII and a recent, rapid spread of the hybrid progeny in domestic transmission cycles concomitant with, or as a result of, disruption of natural transmission cycles by human activities

The Patient-Oriented Eczema Measure in young children:Responsiveness and minimal clinically important difference

BACKGROUND: The Patient‐Oriented Eczema Measure (POEM) has been recommended as the core patient‐reported outcome measure for trials of eczema treatments. Using data from the Choice of Moisturiser for Eczema Treatment randomized feasibility study, we assess the responsiveness to change and determine the minimal clinically important difference (MCID) of the POEM in young children with eczema. METHODS: Responsiveness to change by repeated administrations of the POEM was investigated in relation to change recalled using the Parent Global Assessment (PGA) measure. Five methods of determining the MCID of the POEM were employed; three anchor‐based methods using PGA as the anchor: the within‐patient score change, between‐patient score change and sensitivity and specificity method, and two distribution‐based methods: effect size estimate and the one half standard deviation of the baseline distribution of POEM scores. RESULTS: Successive POEM scores were found to be responsive to change in eczema severity. The MCID of the POEM change score, in relation to a slight improvement in eczema severity as recalled by parents on the PGA, estimated by the within‐patient score change (4.27), the between‐patient score change (2.89) and the sensitivity and specificity method (3.00) was similar to the one half standard deviation of the POEM baseline scores (2.94) and the effect size estimate (2.50). CONCLUSIONS: The Patient‐Oriented Eczema Measure as applied to young children is responsive to change, and the MCID is around 3. This study will encourage the use of POEM and aid in determining sample size for future randomized controlled trials of treatments for eczema in young children

Critical Exponent for the Density of Percolating Flux

This paper is a study of some of the critical properties of a simple model for flux. The model is motivated by gauge theory and is equivalent to the Ising model in three dimensions. The phase with condensed flux is studied. This is the ordered phase of the Ising model and the high temperature, deconfined phase of the gauge theory. The flux picture will be used in this phase. Near the transition, the density is low enough so that flux variables remain useful. There is a finite density of finite flux clusters on both sides of the phase transition. In the deconfined phase, there is also an infinite, percolating network of flux with a density that vanishes as $T \rightarrow T_{c}^{+}$. On both sides of the critical point, the nonanalyticity in the total flux density is characterized by the exponent $(1-\alpha)$. The main result of this paper is a calculation of the critical exponent for the percolating network. The exponent for the density of the percolating cluster is $\zeta = (1-\alpha) - (\varphi-1)$. The specific heat exponent $\alpha$ and the crossover exponent $\varphi$ can be computed in the $\epsilon$-expansion. Since $\zeta < (1-\alpha)$, the variation in the separate densities is much more rapid than that of the total. Flux is moving from the infinite cluster to the finite clusters much more rapidly than the total density is decreasing.Comment: 20 pages, no figures, Latex/Revtex 3, UCD-93-2

Diagnosis, assessment and treatment of childhood eczema in primary care:cross-sectional study

Background: The majority of children with eczema in the UK are looked after in primary care yet we know little about their care in this setting. Aim: To compare the diagnosis, assessment, and treatment of eczema in primary care with published diagnostic criteria and management guidelines. Design & setting: Cross-sectional study using data from a randomised controlled feasibility study. General practices, UK. Method: Baseline data from children aged 1 month to 5 years recruited ‘in-consultation’ for the Choice of Moisturiser in Eczema Treatment (COMET) feasibility study was used. These included clinician diagnosis and global severity assessment; the parent-completed Patient Orientated Eczema Measure (POEM); a questionnaire about eczema treatments, including use of topical corticosteroid (TCS); and, the Eczema Area Severity Index (EASI) carried out by trained researchers. Descriptive analyses were undertaken to compare diagnoses with UK diagnostic criteria, severity assessments, and treatment with the National Institute for Health and Care Excellent (NICE) guidance. Results: Data were available for 90 participants. Only 46% of participants labelled as having eczema met the UK diagnostic criteria. Agreement between the global severity assessment by a healthcare practitioner with the EASI and POEM measures of eczema severity were 44% and 48% respectively. Emollients and TCSs were underused with 44% of participants not using any emollient and 46% using one or more TCSs. The ‘match’ between eczema severity and TCSs potency was poor. Conclusion: Discrepancies were found between the diagnosis, assessment, and treatment of children with eczema in primary care, and UK diagnostic criteria and guidelines. Further investigation to explore the reasons for this discordance, and whether it matters, is needed