Interstitial lung disease is a common manifestation of rheumatoid arthritis; however, little is known about factors that influence its prognosis. The aim of the present study was to determine whether ...or not the usual interstitial pneumonia pattern found on high-resolution computed tomography (HRCT) is of prognostic significance in rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Patients with RA-ILD were identified retrospectively (n = 82). The relationship of a definite usual interstitial pneumonia pattern on HRCT to survival was determined and compared to that in a cohort of patients with radiologically diagnosed idiopathic pulmonary fibrosis (n = 51). A definite usual interstitial pneumonia pattern was seen in 20 (24%) out of 82 patients with RA-ILD. These patients showed worse survival than those without this pattern (median survival 3.2 versus 6.6 yrs), and a similar survival to those with idiopathic pulmonary fibrosis. On multivariate analysis, a definite usual interstitial pneumonia pattern on HRCT was associated with worse survival (hazard ratio of 2.3). Analysis of specific HRCT features demonstrated that traction bronchiectasis and honeycomb fibrosis were associated with worse survival (hazard ratio of 2.6 and 2.1, respectively). Female sex (hazard ratio of 0.30) and a higher baseline diffusing capacity of the lung for carbon monoxide (hazard ratio of 0.96) were associated with better survival. A definite usual interstitial pneumonia pattern on HRCT has important prognostic implications in RA-ILD.
Healthcare-acquired COVID-19 has been an additional burden on hospitals managing increasing numbers of patients with SARS-CoV-2. One acute hospital (W) among three in a Scottish healthboard ...experienced an unexpected surge of COVID-19 clusters.
To investigate possible causes of COVID-19 clusters at Hospital W.
Daily surveillance provided total numbers of patients and staff involved in clusters in three acute hospitals (H, M and W) and care homes across the healthboard. All clusters were investigated and documented, along with patient boarding, community infection rates and outdoor temperatures from October 2020 to March 2021. Selected SARS-CoV-2 strains were genotyped.
There were 19 COVID-19 clusters on 14 wards at Hospital W during the six-month study period, lasting from two to 42 days (average, five days; median, 14 days) and involving an average of nine patients (range 1–24) and seven staff (range 0–17). COVID-19 clusters in Hospitals H and M reflected community infection rates. An outbreak management team implemented a control package including daily surveillance; ward closures; universal masking; screening; restricting staff and patient movement; enhanced cleaning; and improved ventilation. Forty clusters occurred across all three hospitals before a January window-opening policy, after which there were three during the remainder of the study.
The winter surge of COVID-19 clusters was multi-factorial, but clearly exacerbated by moving trauma patients around the hospital. An extended infection prevention and control package including enhanced natural ventilation helped reduce COVID-19 clusters in acute hospitals.
•High order (up to 10th) difference schemes on unstructured disordered node sets.•Spatially varying resolution, stencil optimisation and filtering.•High order boundary conditions for complex ...geometries.•Simulations of isothermal Navier-Stokes equations.•Moderate to high Reynolds number flows through porous media.
Mesh-free methods have significant potential for simulations of flows in complex geometries, with the difficulties of domain discretisation greatly reduced. However, many mesh-free methods are limited to low order accuracy. In order to compete with conventional mesh-based methods, high order accuracy is essential. The Local Anisotropic Basis Function Method (LABFM) is a mesh-free method introduced in King et al. (2020) 20, which enables the construction of highly accurate difference operators on disordered node discretisations. Here, we introduce a number of developments to LABFM, in the areas of basis function construction, stencil optimisation, stabilisation, variable resolution, and high order boundary conditions. With these developments, direct numerical simulations of the Navier Stokes equations are possible at extremely high order (up to 10th order in characteristic node spacing internally). We numerically solve the isothermal compressible Navier Stokes equations for a range of geometries: periodic and channel flows, flows past a cylinder, and porous media. Excellent agreement is seen with analytical solutions, published numerical results (using a spectral element method), and experiments. The potential of the method for direct numerical simulations in complex geometries is demonstrated with simulations of subsonic and transonic flows through an inhomogeneous porous media at pore Reynolds numbers up to Rep=968.
Viscoelastic flows occur widely, and numerical simulations of them are important for a range of industrial applications. Simulations of viscoelastic flows are more challenging than their Newtonian ...counterparts due to the presence of exponential gradients in polymeric stress fields, which can lead to catastrophic instabilities if not carefully handled. A key development to overcome this issue is the log-conformation formulation, which has been applied to a range of numerical methods, but not previously applied to Smoothed Particle Hydrodynamics (SPH). Here we present a 2D incompressible SPH algorithm for viscoelastic flows which, for the first time, incorporates a log-conformation formulation with an elasto-viscous stress splitting (EVSS) technique. The resulting scheme enables simulations of flows at high Weissenberg numbers (accurate up to Wi=85 for Poiseuille flow). The method is robust, and able to handle both internal and free-surface flows, and a range of linear and non-linear constitutive models. Several test cases are considered including flow past a periodic array of cylinders and jet buckling. This work presents a significant step change in capabilities compared to previous SPH algorithms for viscoelastic flows, and has the potential to simulate a wide range of new and challenging applications.
•Incompressible SPH with the log-conformation formulation.•Formulation allows robust simulations at high Weissenberg numbers.•Capable of internal and free-surface flows with large deformation.•Linear and non-linear viscoelastic models.•Stabilisation for UCM fluids provided by an EVSS scheme.
Toxicants have both sub-lethal and lethal effects on aquatic biota, influencing organism fitness and community composition. However, toxicant effects within ecosystems may be altered by interactions ...with abiotic and biotic ecosystem components, including biological interactions. Collectively, this generates the potential for toxicant sensitivity to be highly context dependent, with significantly different outcomes in ecosystems than laboratory toxicity tests predict. We experimentally manipulated stream macroinvertebrate communities in 32 mesocosms to examine how communities from a low-salinity site were influenced by interactions with those from a high-salinity site along a gradient of salinity. Relative to those from the low-salinity site, organisms from the high-salinity site were expected to have greater tolerance and fitness at higher salinities. This created the potential for both salinity and tolerant-sensitive organism interactions to influence communities. We found that community composition was influenced by both direct toxicity and tolerant-sensitive organism interactions. Taxon and context-dependent responses included: (i) direct toxicity effects, irrespective of biotic interactions; (ii) effects that were owing to the addition of tolerant taxa, irrespective of salinity; (iii) toxicity dependent on sensitive-tolerant taxa interactions; and (iv) toxic effects that were increased by interactions. Our results reinforce that ecological processes require consideration when examining toxicant effects within ecosystems.This article is part of the theme issue 'Salt in freshwaters: causes, ecological consequences and future prospects'.
Summary
Streptococcus pneumoniae colonization of the human airway is an essential precursor for disease; however, the mechanisms by which the bacterium establishes and maintains colonization are ...poorly understood. It is becoming increasingly clear that S. pneumoniae expresses glycosidases that can modify many glycan structures present in the human airway, including N‐linked glycans, O‐linked glycans, and glycosaminoglycans. Many of these glycosidases have been shown to contribute to in vivo colonization. Although the precise role of these glycosidases during colonization remains to be elucidated, in vitro assays suggest that pneumococcal modification of host sugars may contribute to colonization in a variety of ways. Experimental evidence supports a role for pneumococcal glycosidases in providing a carbon source for growth, biofilm formation, competition with other bacteria within the airway, and exposing receptors for adherence. Herein we review the ability of S. pneumoniae to modify host sugars and the functional effects of these modifications.
Summary
Background
Validated, reliable, globally accepted outcome measurement instruments for hidradenitis suppurativa (HS) are needed. Current tools to measure the physical signs domain for HS rely ...on lesion counts, which are time‐consuming and unreliable.
Objectives
To assess the reliability and validity of the Hidradenitis suppurativa Area and Severity Index Revised (HASI‐R) tool, a novel method for assessing HS severity, incorporating signs of inflammation and body surface area involved.
Methods
The measurement properties of the HASI‐R tool were evaluated. The tool was created by combining the previously published HASI and Severity and Area Score for Hidradenitis instruments. Twenty raters evaluated 15 patients with HS in a hospital‐based ambulatory dermatology clinic. The objectives of the study were to assess inter‐ and intra‐rater reliability of the HASI‐R and its components, as well as its construct and known‐groups validity. Existing lesion count‐based clinician‐reported measures of HS and their components were also assessed. Raters were also asked their preferences regarding the various HS severity assessment tools.
Results
The HASI‐R had moderate inter‐rater reliability intra‐class correlation coefficients (ICC) 0·60. This was better than all other HS physical sign outcome measures evaluated, which had poor inter‐rater reliability (ICC < 0·5). HASI‐R had the highest intra‐rater reliability (ICC 0·91). The HASI‐R had good construct validity and demonstrated known‐groups validity. The HASI‐R was also the most preferred tool by all raters.
Conclusions
Results from the clinometric assessment of the HASI‐R are encouraging, and support continued evaluation of this clinician‐reported outcome measure.
What is already known about this topic?
The reliability of physician‐reported outcome measures for hidradenitis suppurativa (HS), comprised of counting lesions, has come under scrutiny.
Current physician‐reported outcome measures lack assessment of body surface area (BSA).
The original Hidradenitis suppurativa Area and Severity Instrument (HASI) and Severity and Area Score for Hidradenitis (SASH) are two HS severity assessment instruments combining signs of inflammation with BSA, dispensing with traditional lesion counts.
What does this study add?
The two groups that created the HASI and SASH merged the two instruments into a single tool called the Hidradenitis suppurativa Area and Severity Instrument Revised (HASI‐R).
Clinometric assessment of the HASI‐R was completed, including inter‐ and intra‐rater reliability, convergent/divergent validity and known‐groups validity.
Results from the clinometric assessment are encouraging and support continued validation of the HASI‐R.
What are the clinical implications of this work?
Currently, only one drug is approved by the US Food and Drug Administration for the treatment of HS.
The use of outcome measures in clinical trials with lower reliability, higher limits of agreement and higher minimal detectable change increases the risk that a treatment effect will be obscured (false‐negative), which can result in the discarding of promising new therapies.
High‐quality outcome measures for HS are urgently needed.
Linked Comment: Emtestam et al. Br J Dermatol 2021; 184:796–798.
The C-Band All-Sky Survey is a project to map the full sky in total intensity and linear polarization at 5 GHz. The northern component of the survey uses a broad-band single-frequency analogue ...receiver fitted to a 6.1-m telescope at the Owens Valley Radio Observatory in California, USA. The receiver architecture combines a continuous-comparison radiometer and a correlation polarimeter in a single receiver for stable simultaneous measurement of both total intensity and linear polarization, using custom-designed analogue receiver components. The continuous-comparison radiometer measures the temperature difference between the sky and temperature-stabilized cold electrical reference loads. A cryogenic front-end is used to minimize receiver noise, with a system temperature of 30 K in both linear polarization and total intensity. Custom cryogenic notch filters are used to counteract man-made radio frequency interference. The radiometer 1/f noise is dominated by atmospheric fluctuations, while the polarimeter achieves a 1/f noise knee frequency of 10 mHz, similar to the telescope azimuthal scan frequency.
Previous studies suggest genome structure is largely conserved between Eucalyptus species. However, it is unknown if this conservation extends to more divergent eucalypt taxa. We performed ...comparative genomics between the eucalypt genera Eucalyptus and Corymbia. Our results will facilitate transfer of genomic information between these important taxa and provide further insights into the rate of structural change in tree genomes.
We constructed three high density linkage maps for two Corymbia species (Corymbia citriodora subsp. variegata and Corymbia torelliana) which were used to compare genome structure between both species and Eucalyptus grandis. Genome structure was highly conserved between the Corymbia species. However, the comparison of Corymbia and E. grandis suggests large (from 1-13 MB) intra-chromosomal rearrangements have occurred on seven of the 11 chromosomes. Most rearrangements were supported through comparisons of the three independent Corymbia maps to the E. grandis genome sequence, and to other independently constructed Eucalyptus linkage maps.
These are the first large scale chromosomal rearrangements discovered between eucalypts. Nonetheless, in the general context of plants, the genomic structure of the two genera was remarkably conserved; adding to a growing body of evidence that conservation of genome structure is common amongst woody angiosperms.
Early-stage nasopharyngeal carcinoma (NPC) evades detection when the primary tumor is hidden from view on endoscopic examination. Therefore, in a prospective study of subjects being screened for NPC ...using plasma Epstein–Barr virus (EBV) DNA, we conducted a study to investigate whether magnetic resonance imaging (MRI) could detect endoscopically occult NPC.
Participants with persistently positive EBV DNA underwent endoscopic examination and biopsy when suspicious for NPC, followed by MRI blinded to the endoscopic findings. Participants with a negative endoscopic examination and positive MRI were recalled for biopsy or surveillance. Diagnostic performance was assessed by calculating sensitivity, specificity and accuracy, based on the histologic confirmation of NPC in the initial study or in a follow-up period of at least two years.
Endoscopic examination and MRI were performed on 275 participants, 34 had NPC, 2 had other cancers and 239 without cancer were followed-up for a median of 36months (24–60months). Sensitivity, specificity and accuracy were 76.5%, 97.5% and 94.9%, respectively, for endoscopic examination and 91.2%, 97.5% and 96.7%, respectively, for MRI. NPC was detected only by endoscopic examination in 1/34 (2.9%) participants (a participant with stage I disease), and only by MRI in 6/34 (17.6%) participants (stage I=4, II = 1, III = 1), two of whom had stage I disease and follow-up showing slow growth on MRI but no change on endoscopic examination for 36months.
MRI has a complementary role to play in NPC detection and can enable the earlier detection of endoscopically occult NPC.
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