Material radiopurity control in the XENONnT experiment

The selection of low-radioactive construction materials is of the utmost importance for rare-event searches and thus critical to the XENONnT experiment. Results of an extensive radioassay program are reported, in which material samples have been screened with gamma-ray spectroscopy, mass spectrometry, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{222}$$\end{document}222Rn emanation measurements. Furthermore, the cleanliness procedures applied to remove or mitigate surface contamination of detector materials are described. Screening results, used as inputs for a XENONnT Monte Carlo simulation, predict a reduction of materials background (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim $$\end{document}∼17%) with respect to its predecessor XENON1T. Through radon emanation measurements, the expected \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{222}$$\end{document}222Rn activity concentration in XENONnT is determined to be 4.2 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{+0.5}_{-0.7}$$\end{document}-0.7+0.5) \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu $$\end{document}μBq/kg, a factor three lower with respect to XENON1T. This radon concentration will be further suppressed by means of the novel radon distillation system.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Receiving screened donor human milk for their infant supports parental wellbeing: a mixed-methods study

BACKGROUND

Access to donor human milk (DHM) has primarily been based on the health and development outcomes of premature infants but there has been little examination of the broader impact of an infant receiving it upon parental mental health. Breastfeeding and mental health are closely tied with women who experience breastfeeding difficulties or are unable to meet their own breastfeeding goals often experiencing feelings of guilt, sadness and anger, alongside an increased risk of postnatal depression. The aim of the current study was to explore how experience of receiving DHM for their baby affected the wellbeing of parents.

METHODS

UK parents of infants aged 0 - 12 months who had received screened DHM from a milk bank (typically on the neonatal unit or in some cases in the community) completed an online questionnaire exploring their experiences. The questionnaire included Likert scale items examining perceived impact upon infant health, own wellbeing and family functioning alongside open-ended questions exploring perceptions of how receiving DHM affected wellbeing.

RESULTS

Almost all of the 107 participants (women = 102) agreed that receiving DHM had a positive impact upon infant health and development, their own mental and physical health, and their family's wellbeing. Parents felt relieved that their infant was receiving DHM for health reasons but also due to the experience of being listened to, supported and having their infant feeding decisions facilitated. Receiving DHM helped mothers to process some of their emotions at not being able to breastfeed, in part because knowing their baby was being fed gave them the space to focus on recovery and bonding with their baby. Some parents did experience challenges, feeling guilty at receiving DHM, insecure that another woman was able to feed their baby when they could not, or negative reactions from family. Although the impact of receiving DHM upon breastfeeding was not measured, some women who were working to build their own milk supply noted that it helped motivate them to continue.

CONCLUSIONS

DHM may play an important role not only in protecting infant health and development but in supporting the mental health and wellbeing of mothers for whom their infant receiving human milk is important.

Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis

BACKGROUND

Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry.

METHODS

In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months.

RESULTS

One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability.

CONCLUSION

High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.

First 80Se(n,γ) cross section measurement with high resolution in the full stellar energy range 1 eV - 100 keV and its astrophysical implications for the s-process

Most elements heavier than iron have been generated in the stellar media by means of neutron capture reactions, approximately half are produced by the slow neutron capture or s-process. Radiative neutron capture cross section measurements are of fundamental importance for the study of this mechanism. In this contribution we present a brief summary on the measurement and results for the 80Se(n,γ) cross-section. The experiment was carried out at CERN n_TOF EAR1 via the time of flight (ToF) technique, using four C6D6 scintillation detectors with very fast response. More than a hundred new resonances have been analyzed for the first time with a high accuracy. The MACS obtained at kT = 8 keV is 36% smaller than the recommended value in KADo-NiS. Some of the astrophysical implications of this result are elucidated in this contribution.

Direct Measurement of Carbon Fusion at Astrophysical Energies with Gamma-Particle Coincidences

We present 12C+12C direct fusion measurements with STELLA UKFATIMA, that reach into the region of astrophysics interest relevant to massive stars (M⊙ ≈ 25) using self-supporting thin rotating carbon foils [1]. We demonstrate that detecting gammas and light charged particles in coincidence with nanosecond timing is key for effective background reduction achieving reliable measurements in the sub-nanobarn range. We give details about core developments of the detection apparatus as well as the coincidence-analysis procedure of low count statistics. The present data largely follows the phenomenological hindrance interpolation and shows indication for resonant behaviour at the lowest energy explored.

Cost and prescription trends of P2Y12 inhibitors in Australia over the last decade

Funding Acknowledgements

Type of funding sources: None.

Background

Coronary artery disease (CAD) remains one of the leading causes of mortality worldwide and in Australia, and places significant burden on healthcare costs. [1,2] Dual antiplatelet therapy (DAPT) is guideline therapy following acute coronary syndrome (ACS).[3] Novel, potent P2Y12 inhibitors have been developed and studied but it is unclear how this evidence has been incorporated into patient care across the spectrum of P2Y12 prescribers.

Purpose

We sought to describe the prescribing trends, healthcare costs of P2Y12 therapy in Australia over the last decade using real world prescribing data and cost per MACE prevented.

Method

The latest statistical data collected by the Pharmaceutical Benefit Scheme (PBS), Australia was reviewed. PBS codes for coronary indications were selected. Yearly total prescriptions and cost were then compared between all three P2Y12 inhibitors. Linear trend modelling was used to observe general trends over the data collection period. Cost per mace was calculated from major DAPT ACS trials [4,5].

Results

Total yearly P2Y12 scripts have increased 2.5-fold in Australia between 2010 (403,880 scripts) and 2020 (994,826 scripts). Clopidogrel is the most prescribed P2Y12 inhibitor and has been for the last decade, representing 71% of P2Y12 prescriptions in 2020. Ticagrelor represented 26.2% of total prescriptions but accounts for 75% of PBS spending. More than $30 million is spent on ticagrelor yearly with a cost per MACE prevented of $72,637. Prasugrel was the least prescribed agent but was 41% more cost effective than ticagrelor before being removed from the Australian market. Prasugrel has a cost per MACE prevented of $42,993. Without prasugrel available, Clopidogrel scripts have increased 10% and ticagrelor scripts remain stable.

Conclusion

Clopidogrel remains the most prescribed P2Y12 agent in Australia, despite emergence of more potent P2Y12 inhibitors. Ticagrelor is increasingly prescribed but represents a disproportionately large burden of spending. Whilst Prasugrel is the most efficacious, cost effective and a guideline recommended P2Y12 inhibitor after ACS, it represented the minority of scripts before being withdrawn. Rather than use of a potent P2Y12 agent, clinicians are reverting to prescribing clopidogrel. Compared to other countries in the Asia Pacific region with access to prasugrel, Australian patients may be having higher rates of MACE post PCI at a higher cost compared to Ticagrelor. Abstract Figure.  Abstract Figure.

Estimated energy and nutrient intake for infants following baby-led and traditional weaning approaches

Baby-led weaning (BLW), where infants self-feedwithout the use of spoon-feeding by a caregiver, continues to be a popular approach to starting solids. However, concerns remain amongst health professionals that infants using this method may not consume sufficient energy or nutrients from solid foods. Little research has examined how different weaning approaches shape dietary intake. The aim of this study was to use a three-day weighed diet diary to measure estimated energy and nutrient intake in infants aged 6-12 months. Diet diaries were completed by 71 parents and analysed to compareestimated infant intake from milk and solid foods for those either following a BLW or traditional spoon-feeding approach (TW). Intake was analysed for each weaning group in two age groups: 26-39 and 40-52 weeks, to account for different eating patterns at the start and end of the weaning process. For the younger infants, significant differences in estimatedenergy intake were found, with TW infants consuming 285 kcal from solid foods compared with 120 kcal for BLW infants. Conversely, BLW infants consumed more calories and nutrients from breast or formula milk, consistent with a slower transition to solid foods. No differences were found in estimated intake amongst older infants suggesting BLW infants had 'caught up' with their spoon-fed peers. Overall, few infantsregardless of weaning group met recommended intake guidelines for energy (either over or under consuming) with many deficient in iron and zinc intake. The findings are important for those supporting parents through the transition to solid foods. This article is protected by copyright. All rights reserved.

EP.WE.213Short-term impact of COVID-19 on surgical services in a tertiary hospital

Aim

Since December 2019, SARS-CoV-2 has dramatically impacted the global landscape. One of the biggest challenges has been the additional strain put on healthcare systems. Although there are numerous studies on the effects of COVID-19 on intensive care beds and ventilator availability, there has been little exploration into the wider impacts of COVID-19 on the provision of other services. This study was designed to explore how COVID-19 has impacted surgical service provision at a large NHS hospital.

Methods

We compared the number and types of general surgical procedures carried out in a tertiary centre in the six months prior to the UK COVID-19 outbreak (September 2019-February 2020) and the six months after (March 2020-August 2020).

Results

We found that since March 2020 there has been a 70% decrease in the amount of operations taking place, with numbers dropping from a pre-COVID total of 1761 to a post-COVID total of 529. This mainly affected elective procedures with emergency surgeries remaining relatively constant (48 pre-COVID vs 44 post-COVID).

Conclusion

COVID-19 has caused a significant decrease in the number of surgeries being undertaken. This is due to a combination of factors including staffing issues, reduced investigative capacity, and national mandates on the cessation of non-urgent procedures. Although this mainly affected elective operations, it will have wider implications on future NHS workload and training. The knock on effects will inevitably result in a rise in delayed and emergency presentations with worse patient outcomes.

854 Mortality Associated with Conversion of Total Hip Arthroplasty for Failed Fixation/Hemiarthroplasty for Neck of Femur Fractures

Aim

To identify the mortality associated with failed internal fixation and hemiarthroplasty of neck of femur fractures.

Method

Patients undergoing conversion of internal fixation / hemi arthroplasty were identified from theatre records and surgical databases. Data was stored in Microsoft Excel spreadsheet. Clinical outcomes at 30 days, 1 year and 5 years post conversion total hip replacement.

Results

60 cases were collected between June 2006 and November 2016. 46 females and 14 males involved in the case. The mean age of male patients was 66.5 and for females 67.9. 32 patients had previous sliding hip screw fixation,12 had intra-medullary nails, 8 had cannulated screw fixation and 5 patients had hemiarthroplasty. The mean time to failure was 22 months (Range: 2 weeks to 60 months) and there were 6 cases of late posttraumatic arthritis (range 4 yrs to 23 yrs). Average time from documented failure to conversion THR was 2 months. There were 2 superficial wound infections which were successfully treated with antibiotics. There were 2 cases of deep infection which required multiple debridement, washout, and prolonged inpatient stay. Average duration of hospital stay was 5.7days. 18 patients died before 5 years for reasons unrelated to their hip. All had a functional prosthesis at time of last review. 42 patients alive at 5 years had a functional prosthesis at last review

Conclusions

Total Hip Arthroplasty is a successful procedure for failed fixation / hemiarthroplasty despite the technical challenges. A 3–5-year mortality rate of 33.33 % reflects well against the NHFD 1year mortality of 30 %.

Early weight gain trajectories in first episode anorexia: predictors of outcome for emerging adults in outpatient treatment

BACKGROUND

Early response to treatment has been shown to be a predictor of later clinical outcomes in eating disorders (EDs). Specifically, early weight gain trajectories in anorexia nervosa (AN) have been shown to predict higher rates of later remission in inpatient treatment. However, no study has, as of yet, examined this phenomenon within outpatient treatment of first episode cases of AN or in emerging adults.

METHODS

One hundred seven patients with AN, all between the ages of 16 and 25 and with an illness duration of < 3 years, received treatment via the first episode rapid early intervention in eating disorders (FREED) service pathway. Weight was recorded routinely across early treatment sessions and recovery outcomes (BMI > 18.5 kg/m2 and eating psychopathology) were assessed up to 1 year later. Early weight gain across the first 12 treatment sessions was investigated using latent growth mixture modelling to determine distinct classes of change. Follow-up clinical outcomes and remission rates were compared between classes, and individual and clinical characteristics at baseline (treatment start) were tested as potential predictors.

RESULTS

Four classes of early treatment trajectory were identified. Three of these classes (n = 95), though differing in their early change trajectories, showed substantial improvement in clinical outcomes at final follow-up. One smaller class (n = 12), characterised by a 'higher' start BMI (> 17) and no early weight gain, showed negligible improvement 1 year later. Of the three treatment responding groups, levels of purging, depression, and patient reported carer expressed emotion (in the form of high expectations and low tolerance of the patient) determined class membership, although these findings were not significant after correcting for multiple testing. A higher BMI at treatment start was not sufficient to predict optimal clinical outcomes.

CONCLUSION

First episode cases of AN treated via FREED fit into four distinct early response trajectory classes. These may represent subtypes of first episode AN patients. Three of these four trajectories included patients with substantial improvements 1 year later. For those in the non-response trajectory class, treatment adjustments or augmentations could be considered earlier, i.e., at treatment session 12.

Unilateral axillary adenopathy following COVID-19 vaccination: a multimodality pictorial illustration and review of current guidelines

We present a multimodality pictorial review of axillary lymphadenopathy in patients recently vaccinated against COVID-19. As the mass vaccination programme continues to be rolled out worldwide in an effort to combat the pandemic, it is important that radiologists consider recent COVID-19 vaccination in the differential diagnosis of unilateral axillary lymphadenopathy and are aware of typical appearances across all imaging methods. We review current guidelines on the management of unilateral axillary lymphadenopathy in the context of recent COVID-19 vaccination.

222 Rn emanation measurements for the XENON1T experiment

The selection of low-radioactive construction materials is of utmost importance for the success of low-energy rare event search experiments. Besides radioactive contaminants in the bulk, the emanation of radioactive radon atoms from material surfaces attains increasing relevance in the effort to further reduce the background of such experiments. In this work, we present the 222 Rn emanation measurements performed for the XENON1T dark matter experiment. Together with the bulk impurity screening campaign, the results enabled us to select the radio-purest construction materials, targeting a 222 Rn activity concentration of 10 μ Bq / kg in 3.2 t of xenon. The knowledge of the distribution of the 222 Rn sources allowed us to selectively eliminate problematic components in the course of the experiment. The predictions from the emanation measurements were compared to data of the 222 Rn activity concentration in XENON1T. The final 222 Rn activity concentration of ( 4.5 ± 0.1 ) μ Bq / kg in the target of XENON1T is the lowest ever achieved in a xenon dark matter experiment.