This paper provides a comprehensive and quantitative review of spatial transformations models for nonrigid image registration. It explains the theoretical foundation of the models and classifies them ...according to this basis. This results in two categories, physically based models described by partial differential equations of continuum mechanics (e.g., linear elasticity and fluid flow) and basis function expansions derived from interpolation and approximation theory (e.g., radial basis functions, B-splines and wavelets). Recent work on constraining the transformation so that it preserves the topology or is diffeomorphic is also described. The final section reviews some recent evaluation studies. The paper concludes by explaining under what conditions a particular transformation model is appropriate.
Whole genome sequencing (WGS) offers the potential to predict antimicrobial susceptibility from a single assay. The European Committee on Antimicrobial Susceptibility Testing established a ...subcommittee to review the current development status of WGS for bacterial antimicrobial susceptibility testing (AST).
The published evidence for using WGS as a tool to infer antimicrobial susceptibility accurately is currently either poor or non-existent and the evidence / knowledge base requires significant expansion. The primary comparators for assessing genotypic–phenotypic concordance from WGS data should be changed to epidemiological cut-off values in order to improve differentiation of wild-type from non-wild-type isolates (harbouring an acquired resistance). Clinical breakpoints should be a secondary comparator. This assessment will reveal whether genetic predictions could also be used to guide clinical decision making. Internationally agreed principles and quality control (QC) metrics will facilitate early harmonization of analytical approaches and interpretive criteria for WGS-based predictive AST. Only data sets that pass agreed QC metrics should be used in AST predictions. Minimum performance standards should exist and comparative accuracies across different WGS laboratories and processes should be measured. To facilitate comparisons, a single public database of all known resistance loci should be established, regularly updated and strictly curated using minimum standards for the inclusion of resistance loci. For most bacterial species the major limitations to widespread adoption for WGS-based AST in clinical laboratories remain the current high-cost and limited speed of inferring antimicrobial susceptibility from WGS data as well as the dependency on previous culture because analysis directly on specimens remains challenging.
For most bacterial species there is currently insufficient evidence to support the use of WGS-inferred AST to guide clinical decision making. WGS-AST should be a funding priority if it is to become a rival to phenotypic AST. This report will be updated as the available evidence increases.
Modern Aspects of the Smiles Rearrangement Holden, Catherine M.; Greaney, Michael F.
Chemistry : a European journal,
July 6, 2017, Letnik:
23, Številka:
38
Journal Article
Recenzirano
Odprti dostop
The Smiles rearrangement is an intramolecular SNAr reaction, breaking a C−X single bond and forming a new C−X or C−C bond though ipso substitution. Its vast scope, in terms of nucleophile, leaving ...group, and ring‐size of the transition state, make it a powerful tool for arene functionalization, as it can be employed strategically to switch easily‐forged bonds with more difficult connections that would be challenging to realize in the intermolecular mode. The reaction has received significantly renewed attention in recent years, as advances in areas such as arene C−X bond formation and radical generation have been harnessed for new arene syntheses through Smiles chemistry. In addition, new reaction modes have been discovered, such as the Clayden rearrangement of lithiated ureas, creating innovative applications for Smiles rearrangements in asymmetric arylation. This Minireview will discuss advances in these areas in the recent literature, covering both two‐electron, polar Smiles rearrangements along with single‐electron radical transformations.
How to rearrange a Smile! The Smiles rearrangement is an intramolecular SNAr reaction, breaking a C−X single bond and forming a new C−X or C−C bond though ipso substitution. Recent advances in the literature are discussed in this Minireview, covering both two‐electron, polar Smiles rearrangements along with single‐electron radical transformations.
The reported incidence, prevalence and outcomes of atrial fibrillation (AF) in patients with end-stage renal disease (ESRD) are variable. The risks and benefits of warfarin anticoagulation need to be ...defined as the risk of bleeding in ESRD patients may overwhelm the benefits of embolic stroke prevention. We undertook a systematic literature review to clarify these issues.
A literature search was undertaken using Medline and EMBASE from 1990 to September 2011. Studies that reported incidence, prevalence or selected outcomes in ESRD patients with AF were included. Cross-sectional, cohort and randomized controlled trials with >25 participants were included. The lists of authors and abstracts from the search were reviewed by two investigators to determine the manuscripts for full text review. Data were abstracted to a form designed specifically for this study. The quality of the studies was assessed using the Newcastle-Ottawa scale. Event rates were calculated using a random-effects model.
Twenty-five studies met our inclusion criteria. The prevalence of AF was 11.6% and the overall incidence was 2.7/100 patient-years. The risk of mortality and stroke was increased in ESRD patients with AF at 26.9 and 5.2/100 patient-years versus 13.4 and 1.9/100 patient-years compared with ESRD patients without AF. The majority of studies do not support a protective effect for warfarin in ESRD patients with AF.
The incidence and prevalence of AF in ESRD patients are higher than in the general population and are associated with an increased risk of stroke and mortality. An appropriately designed randomized controlled trial is required to determine whether anticoagulation is an appropriate therapeutic strategy in patients with end-stage renal disease and atrial fibrillation.
The local community around the Nat Turner
rebellion The 1831 Southampton Rebellion led by Nat Turner
involved an entire community. Vanessa M. Holden rediscovers the
women and children, free and ...enslaved, who lived in Southampton
County before, during, and after the revolt. Mapping the region's
multilayered human geography, Holden draws a fuller picture of the
inhabitants, revealing not only their interactions with physical
locations but also their social relationships in space and time.
Her analysis recasts the Southampton Rebellion as one event that
reveals the continuum of practices that sustained resistance and
survival among local Black people. Holden follows how African
Americans continued those practices through the rebellion's
immediate aftermath and into the future, showing how Black women
and communities raised children who remembered and heeded the
lessons absorbed during the calamitous events of 1831.
A bold challenge to traditional accounts, Surviving
Southampton sheds new light on the places and people
surrounding Americas most famous rebellion against slavery.
With the widespread use of antiseptics in healthcare facilities for the prevention of methicillin-resistant Staphylococcus aureus (MRSA) transmission, there are concerns for antiseptic tolerance and ...resistance. We sought to understand the use of chlorhexidine and octenidine, carriage of qac genes, and reduced antiseptic susceptibilities.
A serial cross-sectional study was conducted in an acute care hospital and three extended-care facilities of a healthcare network in June–July, 2014–2016. Two of the extended-care facilities were exposed to intranasal octenidine and universal daily chlorhexidine/octenidine bathing. The minimum inhibitory concentration (MIC) levels and qac genes were determined by broth microdilution tests and whole genome sequencing respectively. Multivariable logistic regression was used to assess for the independent associations between antiseptic exposures, qac genes, and reduced antiseptic susceptibilities.
A total of 878 MRSA isolates were obtained. There were associations between qacA/B carriage and chlorhexidine (adjusted odds ratio (aOR) 7.80; 95% confidence interval (CI) 3.25–18.71) and octenidine (aOR 11.79; 95% CI 5.14–27.04) exposures. Chlorhexidine exposure was associated with reduced chlorhexidine susceptibility (MIC ≥4 mg/L) (aOR 3.15; 95% CI 1.14–8.74). Carriage of qacA/B (aOR 10.65; 95% CI 4.14–27.40) or qacC (aOR 2.55; 95% CI 1.22–5.32) had an association with reduced chlorhexidine susceptibility; while MRSA sequence type modified the association. However, we found no direct association between (i) antiseptics use and qacC carriage, (ii) octenidine exposure and reduced susceptibility, and (iii) reduced octenidine susceptibility and qacA/B or qacC carriage.
Antiseptic exposures were associated with carriage of qac genes. Chlorhexidine exposure was associated with reduced chlorhexidine susceptibility, requiring continued surveillance for the emergence of resistance.
Outbreaks pose a significant risk to patient safety as well as being costly and time consuming to investigate. The implementation of targeted infection prevention and control measures relies on ...infection prevention and control teams having access to rapid results that detect resistance accurately, and typing results that give clinically useful information on the relatedness of isolates. At present, determining whether transmission has occurred can be a major challenge. Conventional typing results do not always have sufficient granularity or robustness to define strains unequivocally, and sufficient epidemiological data are not always available to establish links between patients and the environment. Whole-genome sequencing (WGS) has emerged as the ultimate genotyping tool, but has not yet fully crossed the divide between research method and routine clinical diagnostic microbiological technique. A clinical WGS service was officially established in 2014 as part of the Scottish Healthcare Associated Infection Prevention Institute to confirm or refute outbreaks in hospital settings from across Scotland. This article describes the authors' experiences with the aim of providing new insights into practical application of the use of WGS to investigate healthcare and public health outbreaks. Solutions to overcome barriers to implementation of this technology in a clinical environment are proposed.
Herein, we report a general iminium ion‐based catalytic method for the enantioselective conjugate addition of carbon‐centered radicals to aliphatic and aromatic enals. The process uses an organic ...photoredox catalyst, which absorbs blue light to generate radicals from stable precursors, in combination with a chiral amine catalyst, which secures a consistently high level of stereoselectivity. The generality of this catalytic platform is demonstrated by the stereoselective interception of a wide variety of radicals, including non‐stabilized primary ones which are generally difficult to engage in asymmetric processes. The system also served to develop organocatalytic cascade reactions that combine an iminium‐ion‐based radical trap with an enamine‐mediated step, affording stereochemically dense chiral products in one‐step.
An organocatalytic method for the enantioselective conjugate addition of carbon radicals to aliphatic and aromatic enals is reported. The system imparts consistently high stereoselectivity for the interception of a wide variety of radicals, including highly reactive primary radicals. The protocol also serves to develop radical cascade processes leading to stereochemically dense chiral products in one‐step.
A new benzyne transformation is described that affords versatile biaryl structures without recourse to transition‐metal catalysis or stoichiometric amounts of organometallic building blocks. Aryl ...sulfonamides add to benzyne upon fluoride activation, and then undergo an aryl Truce–Smiles rearrangement to afford biaryls with sulfur dioxide extrusion. The reaction proceeds under simple reaction conditions and has excellent scope for the synthesis of sterically hindered atropisomeric biaryl amines.
All smiles: Metal‐free biaryl synthesis is achieved by adding benzyne to arylsulfonamides. A Smiles rearrangement enables C−C bond formation, thus accessing a variety of functionalized biaryls under mild reaction conditions.
Hip and knee osteoarthritis (OA) are leading causes of global disability. Most research to date has focused on the knee, with results often extrapolated to the hip, and this extends to treatment ...recommendations in clinical guidelines. Extrapolating results from research on knee OA may limit our understanding of disease characteristics specific to hip OA, thereby constraining development and implementation of effective treatments. This review highlights differences between hip and knee OA with respect to prevalence, prognosis, epigenetics, pathophysiology, anatomical and biomechanical factors, clinical presentation, pain and non-surgical treatment recommendations and management.
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